|Heparan sulfate proteoglycan 2|
PDB rendering based on 1gl4.
|Symbols||HSPG2 (; HSPG; PLC; PRCAN; SJA; SJS; SJS1)|
|RNA expression pattern|
Perlecan (PLC) also known as basement membrane-specific heparan sulfate proteoglycan core protein (HSPG) or heparan sulfate proteoglycan 2 (HSPG2), is a protein that in humans is encoded by the HSPG2 gene.
Perlecan is a large multidomain (five domains, labeled I-V) proteoglycan that binds to and cross-links many extracellular matrix (ECM) components and cell-surface molecules. Perlecan is synthesized by both vascular endothelial and smooth muscle cells and deposited in the extracellular matrix. Perlecan is highly conserved across species and the available data indicate that it has evolved from ancient ancestors by gene duplication and exon shuffling.
- 1 Structure
- 2 Function
- 3 Modification of glycosaminoglycan chains
- 4 Degradation
- 5 Expression
- 6 Disease association
- 7 Interactions
- 8 References
- 9 External links
Perlecan consists of a core protein of molecular weight 470 kDa to which three long chains (each approximately 70-100 kDa) of glycosaminoglycans (often heparan sulfate, HS but can be chondroitin sulfate, CS) are attached. The core protein consists of five distinct structural domains. The N-terminal domain I (aa ~1-195) contains attachment sites for HS chains. Although HS chains are not required for correct folding and secretion of the protein, lack of HS or decreased sulfation can decrease perlecan's ability to interact with matrix proteins. Removal of HS chains may affect matrix organization and endothelial barrier function. Domain II comprises four repeats homologous to the ligand-binding portion of the LDL receptor with six conserved cysteine residues and a pentapeptide, DGSDE, which mediates ligand binding by the LDL receptor. Domain III has homology to the domain IVa and IVb of laminin. Domain IV consists of a series of IG modules. The C-terminal Domain V, which has homology to the G domain of the long arm of laminin, is responsible for self-assembly and may be important for basement membrane formation in vivo. Thus, perlecan core protein and HS chains could modulate matrix assembly, cell proliferation, lipoprotein binding and cell adhesion.
A diagram showing the domain structure of perlecan is available here
Perlecan is a key component of the vascular extracellular matrix, here it interacts with a variety of other matrix components and helps to maintain the endothelial barrier function. Perlecan is a potent inhibitor of smooth muscle cell proliferation and is thus thought to help maintain vascular homeostasis. Perlecan can also promote growth factor (e.g., FGF2) activity and thus stimulate endothelial growth and re-generation.
Modification of glycosaminoglycan chains
Modifications of the heparan sulfate chains on C- and N-terminal domains are the best-studied differences in the secretory pathway of perlecan. Chondroitin sulfate can be substituted for heparan sulfate, and sulfate incorporation or the sugar composition of the chains can change. Loss of enzymes involved in the heparan sulfate synthetic pathway lead to a number of conditions.
Differential heparan sulfate chain modification can occur through a number of regulatory signals. Perlecan in the growth plate of mouse long bones shows glycosylation changes in the chondrocyte progression from the resting zone to the proliferating zone. Although initially the glycosaminoglycan (GAG) chains of perlecan were thought to be exclusively heparan sulfate, chondroitin sulfate chains can be substituted during specific regulatory cues. By expressing a recombinant form of the N-terminal domain I of the protein and demonstrating that digestion of the peptide with either heparanase or chondroitinase did not lead to complete loss of the peptide's activity, it was shown that chondroitin sulfate chains can be added to human perlecan. This was in agreement with previous data showing chondroitin sulfate GAG chains attached to bovine perlecan produced by chondrocytes and that recombinant human domain I protein was glycosylated with both heparan and chondroitin sulfate chains when expressed in Chinese Hamster Ovary cells. The preferential addition of heparan sulfate or chondroitin sulfate chains to domains I and V could have an effect on the differentiation of mesenchymal tissues into cartilage, bone or any number of tissues, but the regulatory mechanism of changing from heparan sulfate to chondroitin sulfate addition are not well understood.
While studying the effect of proteoglycan composition on nephritic permselectivity, it was noted that puromycin treatment of human glomerular endothelial cells (HGEC) altered the sulfation level of GAG chains on proteoglycans such as perlecan, which in turn caused a decrease in the stability of the GAG chains. The core protein mRNA levels of proteoglycans were not affected, thus the decrease in GAG chains was as a result of some other factor, which in this case turned out to be a decrease in expression of sulfate transferase enzymes, which play a key role in GAG biosynthesis. It seems that there may be some overlap in diseases stemming from loss of heparan sulfate proteoglycan expression and loss of enzymes involved in heparan sulfate biosynthesis.
Cells can modify their extracellular matrix and basement membranes in response to signals or stress. Specific proteases act on the protein in the extracellular environment when cells have a reason to move or change their surroundings. Cathepsin S is a cysteine protease that moderately attenuates binding of FGF-positive cells to a perlecan-positive substrate. Cathepsin S is a potential protease that acts on the core protein of perlecan in the basement membrane or stroma.
The heparan sulfate chains of perlecan bind growth factors in the ECM, and serve as co-ligands or ligand enhancers when bound to receptors. Another study showed that release of HS-bound basic FGF in culture could be achieved through treatment with stromelysin, heparitinase I, rat collagenase and plasmin, and these proteolysis sites are illustrated in figure 1. This was proposed as a non-exhaustive list of the proteases that could mediate release of growth factors from the heparan sulfate chains of perlecan. Although Whitelock et al. suggested that thrombin cleavage consensus sequences exist in the core protein of perlecan, they also postulate that any thrombin activation of perlecan actually comes from cleavage of other ECM constituents. This article states that heparanase is responsible for cleavage of the heparan sulfate chains of perlecan in matrix. This releases growth factors bound to the heparan sulfate, specifically FGF-10. Addition of heparanase to cell culture of epithelia in basement membrane caused an increase in epithelial cell proliferation due to FGF-10 release.
In a model of explant growth in vitro using corneal epithelium, Matrix Metalloproteinase (MMP) 2 expression correlates with an initial degradation of the original basement membrane. Reformation of basement membrane in culture was dependent on an initial upregulation followed by a downregulation of MMP-9, in contrast to the constant expression of MMP-2. This is not evidence that MMP-2 and MMP-9 directly cleave perlecan protein in vivo but shows that the proteins clearly modulate some factor in maturation of basement membrane. Another family of metalloproteases, the Bone Morphogenetic Protein 1/Tolloid-like family, releases the c-terminal endorepellin domain of the perlecan core protein. The laminin-like globular domain contains the active motif of endorepellin, and is unable to be cleaved by cells expressing mutant and inactive forms of the BMP-1 proteins. Furthermore the critical residue necessary for this cleavage to take place was localized to Asp4197. This proteolytic process may have significance in disease as a corresponding fragment was found in the urine of patients suffering end-stage renal failure and in the amniotic fluid of pregnant women who have undergone premature rupture of the membrane.
Expression during development
Timing of gene expression during development varies from tissue to tissue. Basement membranes are often the driving force behind separating epithelia from stroma and connective tissue. Perlecan is of particular importance in cardiovascular, neural and cartilaginous development.
Pre-implantation blastocyst development is a controlled cascade of gene regulation and intercellular signaling. Extracellular perlecan has been observed at the blastocyst stage of mouse embryonic development, specifically upregulated at the point when the embryo reaches “attachment competence”. This finding was upheld at both the mRNA level and the protein level, shown by RT-PCR and immunostaining. Later embryonic development is just as precisely regulated as pre-implantation development, and is more complicated due to differentiation of all tissues. The first study of perlecan expression during embryonal development found that the protein was first expressed during development of the cardiovascular system, and later correlates with maturation of the majority of tissues in the body, i.e. separation of epithelial layers from endothelia and stroma by basement membranes. Again, this upregulation during cardiovascular development is concomitant with the role of perlecan's C-terminus as endorepellin.
Spatio-temporal specificity in trans-activation of the perlecan gene during development is key to the maturation of basement membranes and thus to the complete separation of epithelia from endothelia and stroma. A thorough study of perlecan expression during chick embryo development has shown that perlecan is present at the morula stage and for the rest of development, although expression can be transient and precisely timed in certain tissue predecessors. In the rat embryo, perlecan expression has been shown to increase in vascular smooth muscle cells (VSMCs) post e19 in fetal development. This correlates perfectly with the ceasing of proliferation of VSMCs at e18 and a change in their phenotype. The theory put forward in this study is that perlecan plays an anti-proliferative role for VSMCs once a certain developmental point is reached, much like confluence-dependent expression of perlecan in culture. These findings were corroborated by similar results from studies of rat pulmonary artery and lung epithelia. These tissues also were found to begin perlecan production once cell division had ceased, around fetal day 19.
The development of the nervous system and extension of axons is precisely directed by cues from extracellular matrix molecules. Olfactory neurite outgrowth in mouse development is guided at least in part by an ECM laid down by olfactory epithelial cells (OECs). Perlecan and laminin-1 appear to be important in this guidance pathway, although perlecan induction occurs slightly later than laminin-1. This data is supported by earlier data showing that OECs express FGF-1 during olfactory development, and that perlecan can stimulate olfactory sensory neurite outgrowth in culture in the presence of FGF-1. Perlecan also showed nerve adhesive properties in a previous study, further suggesting that it may act in an attractive role in combination with laminin rather than a repulsive one.
Cartilage and bone development have proven to be dependent upon perlecan expression. The protein becomes visible by immunostaining on day 15 during mouse development, independently from other basement membrane proteins, suggesting that it is simply a part of the ECM of developing chondrocytes, in addition to collagen II and other cartilage markers that are expressed starting on day 12. Taken with the data, that mice lacking the pln gene cannot maintain stable cartilage, it is apparent that perlecan is essential to the maturation and stability of cartilaginous structure. This is supported by a study showing that knockdown of perlecan production inhibits the final stages of chondrogenic differentiation in C3H10T1/2 fibroblasts in culture. Bone development, i.e. mineralization of cartilaginous tissue, correlates with loss of perlecan and heparan sulfate at the chondro-osseous junction (COJ). In an effort to understand how heparan sulfate and perlecan direct mesenchymal stem cells into the osteogenic pathway, human mesenchymal stem cells were treated with heparanase and chondroitinase in culture. This led to increased mineralization and expression of osteocyte markers, supporting the data showing that loss of heparan sulfate at the COJ is a key factor in osteogenesis. It is thought that the driving force behind heparanase and chondroitinase activation of osteogenesis is release of bone morphogenetic protein bound in the heparan sulfate chains.
Perlecan knockdown in embryonic zebrafish has been achieved through the use of Morpholinos targeted to the perlecan transcript. Morpholinos were used to block translation of the perlecan mRNA in zebrafish embryos, as part of an investigation into perlecan function in skeletal and vascular development. The Morpholino targets the five prime untranslated region of the perlecan mRNA thus blocking translation of the message. Loss of the perlecan protein in these fish led to serious myopathies and circulation problems. As shown in a later study from the same laboratory, this phenotype could be rescued through the addition of exogenous VEGF-A.
The importance of perlecan to mammalian development is demonstrated by perlecan gene knockout experiments. Nearly half of all mice in which the perlecan gene has been knocked out (perlecan null mice) die at embryonic day 10.5, when the perlecan gene normally starts to be expressed. Others die just after birth with severe defects such as abnormal basement membrane formation, defective cephalic and long bone development and achondroplasia. The knockout strategy employed for the first perlecan knockout mouse was a floxing of exon 6 by insertion of a neomycin cassette, and subsequent CRE expression for removal of exon 6 from the genome. This resulted in the cartilage-compromised phenotype previously discussed and loss of basement membrane integrity in a variety of tissues. The fetal mortality rate is high and the mouse that survive die soon after birth. A separately developed perlecan knockout mouse model was created by insertion of a neomycin cassette into exon 7 of the pln gene. These knockout mice were also 40% embryonic lethal, with the rest of the mice dying soon after birth due to severe skeletal abnormalities. In yet another mouse knock-in model, the perlecan gene was mutated by homologous recombination of the endogenous perlecan gene with a construct containing 2 and 5 kb arms of homology surrounding a deleted exon 3, which is only 45 base pairs in length. This deletion abolished heparan sulfate chain attachment to the resulting core protein in vivo. The ensuing study showed that mice lacking heparan sulfate additions on perlecan had collapse of lens capsule integrity by postnatal week 3, indicating a role for heparan sulfate in maintaining lens capsule basement membrane integrity, similar to the TGF-β knockout mouse model. Exon 3 knockout mice also showed decreased wound healing and angiogenesis capabilities when challenged by either epidermal injury or FGF-2 addition to the cornea. In the epidermal injury study, a wound spanning the depth of the epidermis was created in exon 3-negative mice and control mice, and in the knockout mice angiogenesis and the hallmarks of wound healing were slow to develop possibly due to decreased growth factor sequestration by the heparan sulfate-negative perlecan. A similar result was produced in the corneal micropocket assay, where FGF-2 is implanted into the cornea of mice and in normal mice angiogenesis is induced. In the knockout mice this angiogenic effect was impaired, although not completely.
Signaling pathways and their effect on expression
Signaling pathways function to elevate or decrease levels of transcription of genes, which in turn cause cells to change their gene expression profile. The end effect of signaling pathways is exerted on the promoter of genes, which can include elements upstream or downstream of the transcriptional start site, some of which can exist inside of the transcribed gene itself. A number of signaling molecules can effect changes in perlecan expression including the transforming growth factor-Beta (TGF-β), interleukin(IL) and vascular endothelial growth factor (VEGF) families of molecules.
The upstream 2.5 kilobases of the perlecan promoter region were studied by CAT activation in cell lines of various histological origins. This study concluded that there existed a TGF-β responsive element in the promoter just 285 base pairs upstream of the transcriptional start site. This result has been corroborated in such tissues as human colon carcinoma cells. and murine uterine epithelium by in vitro addition of the cytokine to cell culture medium. In vitro studies of TGF-β1 signaling and its effects on perlecan expression can have varying results in different cell types. In human coronary smooth muscle cells in culture, TGF-β1 signaling showed no effect on perlecan expression although it did upregulate other matrix constituents. In vivo demonstration of the dynamic regulation of perlecan and its control by extracellular signaling pathways is critical to our understanding of the protein's role in development. To this end, a transgenic mouse line was created expressing porcine TGF-β1 under the lens-specific αA-crystallin promoter and then another similar line was created but with the gene driven by the βb-crystallin promoter, corresponding to another lens-specific gene. This developmentally dynamic tissue showed a serious misregulation of extracellular matrix components including perlecan with TGF-β1 over expression. Corneal opacification occurred in both transgenic lines early in development due to greatly increased expression of perlecan, fibronectin and thrombospondin-1 in the corneal mesenchyme. The effect was more pronounced in the βB-1 Crystallin promoter-driven line.
The IL family of inflammatory cytokines also upregulates the pln transcript. In a mouse model of Alzheimer's plaque formation, IL-1-alpha effects an increase in perlecan expression in response to brain injury. IL-4 treatment of human gingival fibroblasts in culture led to increased production of various heparan sulfate proteoglycans including perlecan. Treatment of human lung fibroblasts in vitro with IL-1-beta did not lead to any significant increase in perlecan production.
Another signaling pathway shown to augment pln transcription is the VEGF pathway. VEGF165 treatment of human brain microvascular endothelial cells in culture stimulates increased pln transcription. This molecule is a ligand of VEGF Receptor-2 (VGFR2), and it seems that this VEGF165 response is specific for perlecan upregulation, leading to a positive feedback loop involving fibroblastic growth factor (FGF), FGF Recptor (FGFR) and VEGFR2 in response to endothelial damage. This microvascular-specific regulation by VEGF165 raises the possibility that the anti-coagulant function of perlecan is a part of the damage-control process in brain endothelia.
Protein Kinase C signaling is putatively responsible for upregulating transcription and translation of certain proteoglycans including perlecan. When the endocytic pathway of HeLa cells is inhibited by overexpression of a mutant dynamin, Protein Kinase C is activated and perlecan message and protein are subsequently increased. In contrast, the usual downregulation of perlecan in response to hyperglycemia is lost in mice negative for PKC-α.
Interferon-γ signaling mediates transcriptional repression of the perlecan gene. This was first shown in colon cancer cell lines, and subsequently in cell lines of other tissue origins, but in each case intact STAT1 transcription factor was required for the signal to take effect. This led the investigators to believe that the transcription factor STAT1 was interacting with the Pln promoter in the distal region, localized to 660 base pairs upstream of the transcription start site. Interferon- γ treatment of blastocyst-stage murine embryos leads to a loss of perlecan expression on the trophectoderm, and thus an embryonic morphology and phenotype in cell culture, which is suggestive that these interferon-γ treated blastocysts would be defective in implantation. Presumably the loss of perlecan expression stems from downregulation of transcription via STAT1 transcription factor activity as shown previously. These in vitro results are not necessarily representative of normal physiological interferon- γ concentrations, nor are the cytokine normally expressed widely but instead at very specific developmental timepoints. Important to note is that perlecan expression can be decreased by treatment with an exogenous cytokine such as interferon- γ, and if there were a physiologically abnormal increase in expression of the cytokine it could interfere with implantation.
Cell stressors and their effect on expression
Mechanical and chemical stress can damage basement membranes or the cells they support. This could influence the gene expression profile of the cells, especially in their extracellular matrix, which often provides physical support and a chemical barrier for the cells. Hypoxia, inflammation, mechanical and chemical stress have been examined as to how they relate to perlecan expression.
Hypoxia is a condition found in disease states and during injury and often results in a lack of endothelial cell proliferation. This and perlecan's role as endorepellin prompted one study into the nature of perlecan expression regulation by endothelial cells during hypoxic conditions. Under hypoxic conditions, this study found that perlecan expression by rat cardiac microvascular endothelial cells was decreased sixty-one percent compared to normal controls. The contention of this paper is that perlecan downregulation leads to a loss of FAK activation and thus less ERK signaling, leading to decreased cell proliferation. It does seem counterintuitive that endothelial cells would proliferate less quickly due to loss of perlecan and its endorepellin subunit. It could be that these endothelial cells merely downregulated transcription of many genes in response to hypoxic conditions. In another study, hypoxia led to induction of genes associated with apoptosis and cell death, but repression of genes was not limited to proteins associated with a specific pathway. When T84 intestinal epithelial cells are exposed to hypoxic conditions for 24 hours a significant increase in perlecan mRNA and protein production occurs. They relate this to the fact that many genes elevated in response to hypoxia contain a cAMP response element (CRE) in their promoter, as does pln. This difference between endothelial cells from the study in 2007 and the epithelial cell studied in these experiments is indicative of how varied the regulatory mechanisms of perlecan may be in different cell types.
The development of beta-amyloid plaques on the brain is associated with onset of Alzheimer's disease. These plaques induce a constant state of inflammation in areas of accumulation, leading to expression of certain inflammation-related gene products, some of which perpetuate the inflammation in the brain context. As previously mentioned, to investigate the effect of brain inflammation on expression levels of perlecan, needle stab wounds were created in mice brains, and after inflammation and variable periods of recovery, mRNA and protein levels were assessed via in situ hybridization and immunostaining. Perlecan levels were increased in the hippocampus but not in the striatum during the healing period, along with IL 1-alpha expression. Perlecan expression was traced to microglial cells in the hippocampus and astrocytes. This role for perlecan in beta-amyloid plaque generation is supported by an earlier study showing that perlecan and beta-amyloid treatment of rat brains led to formation of senile plaques, whereas treatment with beta-amyloid alone did not have the same effect.
At the organismic level, mechanical stress has a profound impact on extracellular matrix integrity and probably causes induction of a number of ECM genes for repair and remodeling of ECM in tissue stroma and basement membranes. One study examined the in vitro effects of pressure on global gene transcription using a microarray approach and a cell stretching system meant to simulate intraocular pressure in the lamina cribosa (connective tissue) of the optic nerve head. Their findings were that perlecan and several other proteoglycans were upregulated in response to the stretching stimulus. TGF-β2 and VEGF were induced as well, possibly contributing to the upregulation of the perlecan transcript and protein. It has been shown that autocrine TGF-β signaling is a compensatory result of mechanical stress in vitro in endothelial cells. Using a similar cell stretching mechanism to mimic arterial pressure, this investigation showed that perlecan production increased in response to mechanical strain. This is contingent upon TGF-β autocrine signaling in a positive feedback loop with p38 and ERK. This endothelial cell increase in production of VSMC growth inhibitors (i.e. heparin) is reversed in VSMCs, where mechanical stress induces proliferation. Deformation of VSMC cells in culture leads to perlecan upregulation, with a significant increase in sulfation of the heparan sulfate chains. This is not in contrast to the data shown where perlecan expression is constant beyond e19 in rat VSMC, which suggested that perlecan plays an antiproliferative role for VSMCs. In this case, it seems that the molecule's signaling function is the operative upregulated factor, especially due to the increase in sulfation of the heparan sulfate chains.
Chemical damage to organs can affect not only the cell's genetic and mechanical integrity but the extracellular matrix of the tissue. To study the effect of chemical damage on liver cells, wistar rats were treated with carbon tetrachloride for 48 hours prior to sacrificing. Prior to treatment with CCl4, perlecan staining was limited to the bile duct and sinusoidal blood vessels of the liver. After treatment, perlecan staining was intense in areas of necrosis. This could have been due to the increase in capillarization of the liver as an attempt to regenerate damaged tissue. A similar finding was shown in acetamenophin treatment of mice, where perlecan and other matrix components were heavily expressed in necrotic lesions of the liver.
Expression in cell culture
One of the resounding arguments against the validity of in vitro results of cell culture on 2D plastic plates is that the environment does not accurately reflect that of the cells in the organism. This problem is being dealt with by developing 3D cell cultures using a wide variety of substrates as the scaffolds or environments for the cells. In this kind of setting the expression of ECM genes has the potential to more closely resemble that of the native expression profile. 3D scaffolds, the structures on which the cultured cells grow, can be composed of other cells, i.e. cocultures, synthetic polymers mimicking the cells natural environment or purified ECM such as matrigel, and any mixture of these three components.
One such system has been developed to study skin development and basal membrane formation between keratinocytes and the stroma. This system is used to delineate the development of basement membrane between fibroblasts in the stroma (in this case fibroblasts in a type-I collagen gel) and keratinocytes grown on top of the gel. Perlecan expression and thus basement membrane maturation is dependent on nidogen crosslinking of collagen IV and laminin γ1 chain in this system. This effect also led to a lack of hemidesmosomes in the developing tissue. Another system using a disorganized hydrated collagen I gel has been used to demonstrate that primary human corneal fibroblasts will eventually invade the gel and create a matrix consisting of collagen type I and perlecan, as well as several other sulfated matrix glycoproteins. This mimics the in vivo corneal fibroblast's developmental program and response to injury.
One of the long-term goals of creating 3D cell culture systems is to engineer tissues that can be used as replacements for patients with many types of disease. In tissue engineered heart valves created by seeding myofibroblasts onto collagen type I followed by endothelial cells, heparan sulfate proteoglycan expression has been verified, although no distinction between syndecan and perlecan has been made in these tissues. Another procedure that could be made possible by tissue engineering is keratoepithelioplasty. Transplanted tissue must remain intact, which requires a pre-formed basement membrane. Collagen gels have promoted formation of a complete basement membrane by corneal epithelial cells in culture.
Perlecan also holds promise to serve as a scaffold for plating cells in culture. Human salivary gland ductal and acinar cells have been successfully grown on a bioactive peptide containing a sequence repeated in domain IV of the perlecan protein. These cells reproduce acini-like structures similar to those found in the native gland and tight junctions, along with complete basement membranes in culture.
While Perlecan suppression causes substantial inhibition of tumor growth and neovascularization in null mice, in contrast, when perlecan-null cells are injected into nude mice enhanced tumor growth is observed when compared to controls. Cancer progression and pathogenesis is intimately linked to extracellular matrix composition and the role of perlecan and other ECM molecules in cancer is being studied by a large number of laboratories. Since the basement membrane is the first obstacle in the way of extravasating carcinoma cells, the functions of perlecan in this process are multiple. One model system used to study perlecan expression in carcinoma cell lines is that of the MeWo/70W melanoma metastatic progression cell lines. MeWo cells are characteristically less invasive than their clonal variant cell line 70W. One lab studied perlecan expression in 27 invasive melanomas and 26 of the 27 samples showed a significant increase in perlecan message when compared to normal tissue from the same patients. They then used the MeWo and 70W cell lines to study if perlecan expression changed during treatment with neurotrophins, which can stimulate cell invasion through matrigel in vitro. The more invasive 70W cells began expressing perlecan message ten minutes after stimulation with the neurotrophins, and the MeWo cells did not produce any pln message regardless of treatment. This study took special note of the fact that perlecan upregulation occurred even before that of heparanase, an essential protein involved in the process of extravasation.
In ovarian cancer as in other cancers, perlecan expression occurs differently throughout progression of the disease. Perlecan staining is lost in ovarian basement membrane that has been breached by an invasive adenocarcinoma, which is in contrast to perlecan staining in the basement membranes of normal ovaries and those with benign tumors, where basement membrane is homogeneous and very similar in composition to that in other normal tissues. This is consistent with other results showing loss of perlecan in basement membranes affected by invasive cervical cancer spreading to the pelvic lymph nodes, which comes as no surprise due to the correlation of elevated levels of heparanase mRNA expression with invasion of similar cervical carcinoma. By contrast, tumor formation of the immortalized mouse epithelial cell line RT101 injected into rats was dependent on perlecan expression by the mouse cells and not on the presence of endogenous rat perlecan. RT101 cells with perlecan knocked down by antisense did not show tumor formation in this system, however cells expressing the antisense perlecan and a recombinant construct encoding domains I, II, and III of mouse perlecan did indeed show tumor formation. Thus in this system it does appear that tumor cell expression of perlecan is necessary for tumor aggregation. More research into GAG chain or core protein modification by invasive tumor cells as compared to benign tumor cells and normal tissue would be informative to better understand perlecans role in cancer migration.
Several laboratories have studied in vitro tumor cell angiogenesis using antisense constructs to the perlecan message. The full-length reverse complement cDNA, driven by a strong promoter, is transfected into various cell types to completely eliminate perlecan expression. Antisense in colon carcinoma cells blocks perlecan translation, leading to decreased tumor growth and angiogenesis. A similar in vitro decrease in proliferation occurred in NIH 3T3 cells and a human melanoma cell line expressing antisense perlecan mRNA. Findings in vitro with Kaposi's sarcoma cell lines showed that loss of perlecan via transfection with an antisense construct led to decreased proliferation and migration of this highly metastatic cell type. These results are in contrast to in vivo results with the same Kaposi Sarcoma lines, which show that decreased perlecan leads to increased angiogenesis, which facilitates migration and thus is associated with increase in tumor grade. Antisense knockdown of perlecan in fibrosarcoma cell lines led to increased growth and migration both in vitro and in vivo. These findings of greater tumorigenesis in vivo are supported by data showing that the C-terminus of the perlecan protein acts as an endostatic module now known as endorepellin.
A ribozyme construct was created for use in knocking down perlecan translation levels. This ribozyme was targeted at a sequence coding domain I of the perlecan protein. It reduced expression of perlecan up to 80% in the prostate cancer cell line C42B. In contrast to previously discussed studies these cells produced smaller tumors than their parental cells when injected into athymic mice. What this disparity in results means for invasion is unknown, although it is true that perlecan is part of the extracellular matrix in mesenchymal tissue, and cells undergoing epithelial-mesenchymal transition (EMT) may upregulate perlecan expression as part of their EMT programming.
Diabetes and cardiovascular disease
Perlecan levels are decreased in many disease states - e.g., diabetes, atherosclerosis and arthritis. Perlecan has an important role in the maintenance of the glomerular filtration barrier. Decreased perlecan in the glomerular basement membrane has a central role in the development of diabetic albuminuria. Perlecan expression is down regulated by many atherogenic stimuli and thus Perlecan is thought to play a protective role in atherosclerosis. Diabetes and atherosclerosis are commonly associated syndromes. 80% of diabetes-associated deaths involve some form of atherosclerotic complication, and the basement membrane of endothelia has been implicated in the atherogenic process. Synthesis of heparan sulfate was shown to decrease in the arteries of diabetics and in arteries developing atherosclerotic lesions.
The mechanism by which heparan sulfate was downregulated in these lesions remained unknown for some time. One theory states that high glucose in circulation could lead to a decrease in GAG chain attachment to perlecan, but not necessarily a change in the synthetic pathway of the GAG chains or that of the core protein. After treatment of human aortic endothelial cells with high glucose medium, secreted perlecan contained less sulfate incorporation accompanied by less overall GAG chain incorporation. Although no signaling pathway is identified leading to this decrease in GAG chain incorporation, it is suggested that the 30% loss in overall glycosylation of the protein could mean loss of one of the three HS chains on perlecan in this model of diabetes-associated hyperglycemia. It is also noted that similar decreases in extracellular HS without a change in staining for the core protein chains occur in diabetic kidneys and in kidney cells in culture treated with high glucose.
Atherosclerosis is most often the culprit in coronary heart disease and other cardiovascular conditions, and a large aggregation of perlecan protein is symptomatic of advanced atherosclerotic plaques. VSMCs are the producers of the perlecan in this condition, meaning that a good deal of research has been focused on understanding the means of perlecan upregulation in this condition. In a test of the effect of circulating nonesterified fatty acids (symptomatic of diabetes and atherogenesis) on perlecan expression by VSMCs, expression did not change when compared to control cells. This was in contrast to a 2-10-fold increase in expression of other basement membrane proteoglycans. Thrombin is another marker associated with atherogenesis and procoagulation, and it selectively upregulates production of perlecan but not other proteoglycans in human VSMCs in culture. It is suggested that this effect is only seen when VSMCs reach confluence, but not prior to confluence. This concept is similar to previously mentioned studies showing that perlecan is only produced by VSMCs once they have ceased proliferation during development. Another marker in the atherosclerotic pathway is angiotensin II, which also upregulates perlecan expression in VSMCs in culture. Given the prominence of perlecan expression in atherosclerosis there is potential for therapy based upon perlecan expression and research may eventually proceed in that direction.
Perlecan has been shown to interact with
- "Entrez Gene: HSPG2 heparan sulfate proteoglycan 2".
- Kallunki P, Eddy RL, Byers MG, Kestilä M, Shows TB, Tryggvason K (October 1991). "Cloning of human heparan sulfate proteoglycan core protein, assignment of the gene (HSPG2) to 1p36.1----p35 and identification of a BamHI restriction fragment length polymorphism". Genomics 11 (2): 389–96. doi:10.1016/0888-7543(91)90147-7. PMID 1685141.
- Arikawa-Hirasawa E, Le AH, Nishino I, Nonaka I, Ho NC, Francomano CA, Govindraj P, Hassell JR, Devaney JM, Spranger J, Stevenson RE, Iannaccone S, Dalakas MC, Yamada Y (May 2002). "Structural and functional mutations of the perlecan gene cause Schwartz-Jampel syndrome, with myotonic myopathy and chondrodysplasia". Am. J. Hum. Genet. 70 (5): 1368–75. doi:10.1086/340390. PMC 447613. PMID 11941538.
- Iozzo RV (1994). "Perlecan: a gem of a proteoglycan". Matrix Biol. 14 (3): 203–8. doi:10.1016/0945-053X(94)90183-X. PMID 7921536.
- West L, Govindraj P, Koob TJ, Hassell JR (June 2006). "Changes in perlecan during chondrocyte differentiation in the fetal bovine rib growth plate". J. Orthop. Res. 24 (6): 1317–26. doi:10.1002/jor.20160. PMID 16705694.
- French MM, Gomes RR, Timpl R, Höök M, Czymmek K, Farach-Carson MC, Carson DD (January 2002). "Chondrogenic activity of the heparan sulfate proteoglycan perlecan maps to the N-terminal domain I". J. Bone Miner. Res. 17 (1): 48–55. doi:10.1359/jbmr.2002.17.1.48. PMC 1774590. PMID 11771669.
- SundarRaj N, Fite D, Ledbetter S, Chakravarti S, Hassell JR (July 1995). "Perlecan is a component of cartilage matrix and promotes chondrocyte attachment". J. Cell. Sci. 108 (7): 2663–72. PMID 7593307.
- Kokenyesi R, Silbert JE (June 1995). "Formation of heparan sulfate or chondroitin/dermatan sulfate on recombinant domain I of mouse perlecan expressed in Chinese hamster ovary cells". Biochem. Biophys. Res. Commun. 211 (1): 262–7. doi:10.1006/bbrc.1995.1805. PMID 7779094.
- Björnson A, Moses J, Ingemansson A, Haraldsson B, Sörensson J (April 2005). "Primary human glomerular endothelial cells produce proteoglycans, and puromycin affects their posttranslational modification". Am. J. Physiol. Renal Physiol. 288 (4): F748–56. doi:10.1152/ajprenal.00202.2004. PMID 15585670.
- Liuzzo JP, Petanceska SS, Moscatelli D, Devi LA (May 1999). "Inflammatory mediators regulate cathepsin S in macrophages and microglia: A role in attenuating heparan sulfate interactions". Mol. Med. 5 (5): 320–33. PMC 2230418. PMID 10390548.
- Whitelock JM, Murdoch AD, Iozzo RV, Underwood PA (April 1996). "The degradation of human endothelial cell-derived perlecan and release of bound basic fibroblast growth factor by stromelysin, collagenase, plasmin, and heparanases". J. Biol. Chem. 271 (17): 10079–86. doi:10.1074/jbc.271.17.10079. PMID 8626565.
- Patel VN, Knox SM, Likar KM, Lathrop CA, Hossain R, Eftekhari S, Whitelock JM, Elkin M, Vlodavsky I, Hoffman MP (December 2007). "Heparanase cleavage of perlecan heparan sulfate modulates FGF10 activity during ex vivo submandibular gland branching morphogenesis". Development 134 (23): 4177–86. doi:10.1242/dev.011171. PMID 17959718.
- Li W, He H, Kuo CL, Gao Y, Kawakita T, Tseng SC (June 2006). "Basement membrane dissolution and reassembly by limbal corneal epithelial cells expanded on amniotic membrane". Invest. Ophthalmol. Vis. Sci. 47 (6): 2381–9. doi:10.1167/iovs.05-1491. PMC 1569675. PMID 16723447.
- Gonzalez EM, Reed CC, Bix G, Fu J, Zhang Y, Gopalakrishnan B, Greenspan DS, Iozzo RV (February 2005). "BMP-1/Tolloid-like metalloproteases process endorepellin, the angiostatic C-terminal fragment of perlecan". J. Biol. Chem. 280 (8): 7080–7. doi:10.1074/jbc.M409841200. PMID 15591058.
- Oda O, Shinzato T, Ohbayashi K, Takai I, Kunimatsu M, Maeda K, Yamanaka N (November 1996). "Purification and characterization of perlecan fragment in urine of end-stage renal failure patients". Clin. Chim. Acta 255 (2): 119–32. doi:10.1016/0009-8981(96)06395-4. PMID 8937755.
- Vuadens F, Benay C, Crettaz D, Gallot D, Sapin V, Schneider P, Bienvenut WV, Lémery D, Quadroni M, Dastugue B, Tissot JD (August 2003). "Identification of biologic markers of the premature rupture of fetal membranes: proteomic approach". Proteomics 3 (8): 1521–5. doi:10.1002/pmic.200300455. PMID 12923777.
- Smith SE, French MM, Julian J, Paria BC, Dey SK, Carson DD (April 1997). "Expression of heparan sulfate proteoglycan (perlecan) in the mouse blastocyst is regulated during normal and delayed implantation". Dev. Biol. 184 (1): 38–47. doi:10.1006/dbio.1997.8521. PMID 9142982.
- Handler M, Yurchenco PD, Iozzo RV (October 1997). "Developmental expression of perlecan during murine embryogenesis". Dev. Dyn. 210 (2): 130–45. doi:10.1002/(SICI)1097-0177(199710)210:2<130::AID-AJA6>3.0.CO;2-H. PMID 9337134.
- Soulintzi N, Zagris N (2007). "Spatial and temporal expression of perlecan in the early chick embryo". Cells Tissues Organs (Print) 186 (4): 243–56. doi:10.1159/000107948. PMID 17785960.
- Weiser MC, Belknap JK, Grieshaber SS, Kinsella MG, Majack RA (November 1996). "Developmental regulation of perlecan gene expression in aortic smooth muscle cells". Matrix Biol. 15 (5): 331–40. doi:10.1016/S0945-053X(96)90136-5. PMID 8981329.
- Belknap JK, Weiser-Evans MC, Grieshaber SS, Majack RA, Stenmark KR (January 1999). "Relationship between perlecan and tropoelastin gene expression and cell replication in the developing rat pulmonary vasculature". Am. J. Respir. Cell Mol. Biol. 20 (1): 24–34. PMID 9870914.
- Shay EL, Greer CA, Treloar HB (July 2008). "Dynamic expression patterns of ECM molecules in the developing mouse olfactory pathway". Dev. Dyn. 237 (7): 1837–50. doi:10.1002/dvdy.21595. PMC 2787191. PMID 18570250.
- Key B, Treloar HB, Wangerek L, Ford MD, Nurcombe V (March 1996). "Expression and localization of FGF-1 in the developing rat olfactory system". J. Comp. Neurol. 366 (2): 197–206. doi:10.1002/(SICI)1096-9861(19960304)366:2<197::AID-CNE1>3.0.CO;2-0. PMID 8698881.
- Braunewell KH, Pesheva P, McCarthy JB, Furcht LT, Schmitz B, Schachner M (April 1995). "Functional involvement of sciatic nerve-derived versican- and decorin-like molecules and other chondroitin sulphate proteoglycans in ECM-mediated cell adhesion and neurite outgrowth". Eur. J. Neurosci. 7 (4): 805–14. doi:10.1111/j.1460-9568.1995.tb00683.x. PMID 7620627.
- French MM, Smith SE, Akanbi K, Sanford T, Hecht J, Farach-Carson MC, Carson DD (May 1999). "Expression of the heparan sulfate proteoglycan, perlecan, during mouse embryogenesis and perlecan chondrogenic activity in vitro". J. Cell Biol. 145 (5): 1103–15. doi:10.1083/jcb.145.5.1103. PMC 2133131. PMID 10352025.
- Costell M, Gustafsson E, Aszódi A, Mörgelin M, Bloch W, Hunziker E, Addicks K, Timpl R, Fässler R (November 1999). "Perlecan maintains the integrity of cartilage and some basement membranes". J. Cell Biol. 147 (5): 1109–22. doi:10.1083/jcb.147.5.1109. PMC 2169352. PMID 10579729.
- Gomes RR, Joshi SS, Farach-Carson MC, Carson DD (February 2006). "Ribozyme-mediated perlecan knockdown impairs chondrogenic differentiation of C3H10T1/2 fibroblasts". Differentiation 74 (1): 53–63. doi:10.1111/j.1432-0436.2005.00055.x. PMC 1403289. PMID 16466400.
- Brown AJ, Alicknavitch M, D'Souza SS, Daikoku T, Kirn-Safran CB, Marchetti D, Carson DD, Farach-Carson MC (October 2008). "Heparanase expression and activity influences chondrogenic and osteogenic processes during endochondral bone formation". Bone 43 (4): 689–99. doi:10.1016/j.bone.2008.05.022. PMC 2621444. PMID 18589009.
- Gomes RR, Van Kuppevelt TH, Farach-Carson MC, Carson DD (December 2006). "Spatiotemporal distribution of heparan sulfate epitopes during murine cartilage growth plate development". Histochem. Cell Biol. 126 (6): 713–22. doi:10.1007/s00418-006-0203-4. PMID 16835755.
- Manton KJ, Leong DF, Cool SM, Nurcombe V (November 2007). "Disruption of heparan and chondroitin sulfate signaling enhances mesenchymal stem cell-derived osteogenic differentiation via bone morphogenetic protein signaling pathways". Stem Cells 25 (11): 2845–54. doi:10.1634/stemcells.2007-0065. PMID 17702986.
- Zoeller JJ, McQuillan A, Whitelock J, Ho SY, Iozzo RV (April 2008). "A central function for perlecan in skeletal muscle and cardiovascular development". J. Cell Biol. 181 (2): 381–94. doi:10.1083/jcb.200708022. PMC 2315682. PMID 18426981.
- Zoeller JJ, Whitelock JM, Iozzo RV (May 2009). "Perlecan regulates developmental angiogenesis by modulating the VEGF-VEGFR2 axis". Matrix Biol. 28 (5): 284–91. doi:10.1016/j.matbio.2009.04.010. PMC 2705690. PMID 19422911.
- Girós A, Morante J, Gil-Sanz C, Fairén A, Costell M (2007). "Perlecan controls neurogenesis in the developing telencephalon". BMC Dev. Biol. 7: 29. doi:10.1186/1471-213X-7-29. PMC 1852307. PMID 17411441.
- Arikawa-Hirasawa E, Watanabe H, Takami H, Hassell JR, Yamada Y (1999). "Perlecan is essential for cartilage and cephalic development". Nat. Genet. 23 (3): 354–8. doi:10.1038/15537. PMID 10545953.
- Rossi M, Morita H, Sormunen R, Airenne S, Kreivi M, Wang L, Fukai N, Olsen BR, Tryggvason K, Soininen R (January 2003). "Heparan sulfate chains of perlecan are indispensable in the lens capsule but not in the kidney". EMBO J. 22 (2): 236–45. doi:10.1093/emboj/cdg019. PMC 140094. PMID 12514129.
- Srinivasan Y, Lovicu FJ, Overbeek PA (February 1998). "Lens-specific expression of transforming growth factor beta1 in transgenic mice causes anterior subcapsular cataracts". J. Clin. Invest. 101 (3): 625–34. doi:10.1172/JCI1360. PMC 508606. PMID 9449696.
- Flügel-Koch C, Ohlmann A, Piatigorsky J, Tamm ER (October 2002). "Disruption of anterior segment development by TGF-β1 overexpression in the eyes of transgenic mice". Dev. Dyn. 225 (2): 111–25. doi:10.1002/dvdy.10144. PMID 12242711.
- Zhou Z, Wang J, Cao R, Morita H, Soininen R, Chan KM, Liu B, Cao Y, Tryggvason K (July 2004). "Impaired angiogenesis, delayed wound healing and retarded tumor growth in perlecan heparan sulfate-deficient mice". Cancer Res. 64 (14): 4699–702. doi:10.1158/0008-5472.CAN-04-0810. PMID 15256433.
- Gomes RR, Farach-Carson MC, Carson DD (2004). "Perlecan functions in chondrogenesis: insights from in vitro and in vivo models". Cells Tissues Organs (Print) 176 (1-3): 79–86. doi:10.1159/000075029. PMID 14745237.
- Hassell J, Yamada Y, Arikawa-Hirasawa E (2002). "Role of perlecan in skeletal development and diseases". Glycoconj. J. 19 (4-5): 263–7. doi:10.1023/A:1025340215261. PMID 12975604.
- Iozzo RV, Pillarisetti J, Sharma B, Murdoch AD, Danielson KG, Uitto J, Mauviel A (February 1997). "Structural and functional characterization of the human perlecan gene promoter. Transcriptional activation by transforming growth factor-beta via a nuclear factor 1-binding element". J. Biol. Chem. 272 (8): 5219–28. doi:10.1074/jbc.272.8.5219. PMID 9030592.
- Dodge GR, Kovalszky I, Hassell JR, Iozzo RV (October 1990). "Transforming growth factor beta alters the expression of heparan sulfate proteoglycan in human colon carcinoma cells". J. Biol. Chem. 265 (29): 18023–9. PMID 1698783.
- Morris JE, Gaza G, Potter SW (February 1994). "Specific stimulation of basal lamina heparan sulfate proteoglycan in mouse uterine epithelium by Matrigel and by transforming growth factor-beta 1". In Vitro Cell. Dev. Biol. Anim. 30A (2): 120–8. doi:10.1007/BF02631404. PMID 8012654.
- Schmidt A, Lorkowski S, Seidler D, Breithardt G, Buddecke E (July 2006). "TGF-beta1 generates a specific multicomponent extracellular matrix in human coronary SMC". Eur. J. Clin. Invest. 36 (7): 473–82. doi:10.1111/j.1365-2362.2006.01658.x. PMID 16796604.
- García de Yébenes E, Ho A, Damani T, Fillit H, Blum M (August 1999). "Regulation of the heparan sulfate proteoglycan, perlecan, by injury and interleukin-1alpha". J. Neurochem. 73 (2): 812–20. doi:10.1046/j.1471-4159.1999.0730812.x. PMID 10428080.
- Hashimoto-Uoshima M, Noguchi K, Suzuki M, Murata A, Yanagishita M, Ishikawa I (February 2002). "Effects of interleukin-4 on proteoglycan accumulation in human gingival fibroblasts". J. Periodont. Res. 37 (1): 42–9. doi:10.1034/j.1600-0765.2002.00642.x. PMID 11842937.
- Tufvesson E, Westergren-Thorsson G (March 2000). "Alteration of proteoglycan synthesis in human lung fibroblasts induced by interleukin-1beta and tumor necrosis factor-alpha". J. Cell. Biochem. 77 (2): 298–309. doi:10.1002/(SICI)1097-4644(20000501)77:2<298::AID-JCB12>3.0.CO;2-D. PMID 10723095.
- Kaji T, Yamamoto C, Oh-i M, Fujiwara Y, Yamazaki Y, Morita T, Plaas AH, Wight TN (September 2006). "The vascular endothelial growth factor VEGF165 induces perlecan synthesis via VEGF receptor-2 in cultured human brain microvascular endothelial cells". Biochim. Biophys. Acta 1760 (9): 1465–74. doi:10.1016/j.bbagen.2006.06.010. PMID 16914267.
- Llorente A, Prydz K, Sprangers M, Skretting G, Kolset SO, Sandvig K (January 2001). "Proteoglycan synthesis is increased in cells with impaired clathrin-dependent endocytosis". J. Cell. Sci. 114 (Pt 2): 335–43. PMID 11148135.
- Menne J, Park JK, Boehne M, Elger M, Lindschau C, Kirsch T, Meier M, Gueler F, Fiebeler A, Bahlmann FH, Leitges M, Haller H (August 2004). "Diminished loss of proteoglycans and lack of albuminuria in protein kinase C-alpha-deficient diabetic mice". Diabetes 53 (8): 2101–9. doi:10.2337/diabetes.53.8.2101. PMID 15277392.
- Sharma B, Iozzo RV (February 1998). "Transcriptional silencing of perlecan gene expression by interferon-gamma". J. Biol. Chem. 273 (8): 4642–6. doi:10.1074/jbc.273.8.4642. PMID 9468523.
- Fontana V, Choren V, Vauthay L, Calvo JC, Calvo L, Cameo M (December 2004). "Exogenous interferon-gamma alters murine inner cell mass and trophoblast development. Effect on the expression of ErbB1, ErbB4 and heparan sulfate proteoglycan (perlecan)". Reproduction 128 (6): 717–25. doi:10.1530/rep.1.00335. PMID 15579589.
- Li YZ, Liu XH, Cai LR (April 2007). "Down-regulation of perlecan expression contributes to the inhibition of rat cardiac microvascular endothelial cell proliferation induced by hypoxia". Sheng Li Xue Bao 59 (2): 221–6. PMID 17437047.
- Jin K, Mao XO, Eshoo MW, del Rio G, Rao R, Chen D, Simon RP, Greenberg DA (October 2002). "cDNA microarray analysis of changes in gene expression induced by neuronal hypoxia in vitro". Neurochem. Res. 27 (10): 1105–12. doi:10.1023/A:1020913123054. PMID 12462408.
- Furuta GT, Dzus AL, Taylor CT, Colgan SP (August 2000). "Parallel induction of epithelial surface-associated chemokine and proteoglycan by cellular hypoxia: implications for neutrophil activation". J. Leukoc. Biol. 68 (2): 251–9. PMID 10947070.
- Snow AD, Sekiguchi R, Nochlin D, Fraser P, Kimata K, Mizutani A, Arai M, Schreier WA, Morgan DG (January 1994). "An important role of heparan sulfate proteoglycan (Perlecan) in a model system for the deposition and persistence of fibrillar A beta-amyloid in rat brain". Neuron 12 (1): 219–34. doi:10.1016/0896-6273(94)90165-1. PMID 8292358.
- Kirwan RP, Fenerty CH, Crean J, Wordinger RJ, Clark AF, O'Brien CJ (2005). "Influence of cyclical mechanical strain on extracellular matrix gene expression in human lamina cribrosa cells in vitro". Mol. Vis. 11: 798–810. PMID 16205625.
- Baker AB, Ettenson DS, Jonas M, Nugent MA, Iozzo RV, Edelman ER (August 2008). "Endothelial cells provide feedback control for vascular remodeling through a mechanosensitive autocrine TGF-beta signaling pathway". Circ. Res. 103 (3): 289–97. doi:10.1161/CIRCRESAHA.108.179465. PMC 2766078. PMID 18583708.
- Morita N, Iizuka K, Murakami T, Kawaguchi H (July 2004). "N-terminal kinase, and c-Src are activated in human aortic smooth muscle cells by pressure stress". Mol. Cell. Biochem. 262 (1-2): 71–8. doi:10.1023/B:MCBI.0000038218.09259.1c. PMID 15532711.
- Lee RT, Yamamoto C, Feng Y, Potter-Perigo S, Briggs WH, Landschulz KT, Turi TG, Thompson JF, Libby P, Wight TN (April 2001). "Mechanical strain induces specific changes in the synthesis and organization of proteoglycans by vascular smooth muscle cells". J. Biol. Chem. 276 (17): 13847–51. doi:10.1074/jbc.M010556200. PMID 11278699.
- Gallai M, Kovalszky I, Knittel T, Neubauer K, Armbrust T, Ramadori G (May 1996). "Expression of extracellular matrix proteoglycans perlecan and decorin in carbon-tetrachloride-injured rat liver and in isolated liver cells". Am. J. Pathol. 148 (5): 1463–71. PMC 1861584. PMID 8623917.
- Cozma LG, Alexa ID, Dobrescu G (2004). "[Transcriptional and electron microscopic analysis of extracellular matrix proteoglycans in acute acetaminophen intoxication]". Rev Med Chir Soc Med Nat Iasi (in Romanian) 108 (2): 452–7. PMID 15688831.
- Stark HJ, Baur M, Breitkreutz D, Mirancea N, Fusenig NE (May 1999). "Organotypic keratinocyte cocultures in defined medium with regular epidermal morphogenesis and differentiation". J. Invest. Dermatol. 112 (5): 681–91. doi:10.1046/j.1523-1747.1999.00573.x. PMID 10233757.
- Breitkreutz D, Mirancea N, Schmidt C, Beck R, Werner U, Stark HJ, Gerl M, Fusenig NE (May 2004). "Inhibition of basement membrane formation by a nidogen-binding laminin gamma1-chain fragment in human skin-organotypic cocultures". J. Cell. Sci. 117 (Pt 12): 2611–22. doi:10.1242/jcs.01127. PMID 15159456.
- Ren R, Hutcheon AE, Guo XQ, Saeidi N, Melotti SA, Ruberti JW, Zieske JD, Trinkaus-Randall V (October 2008). "Human primary corneal fibroblasts synthesize and deposit proteoglycans in long-term 3-D cultures". Dev. Dyn. 237 (10): 2705–15. doi:10.1002/dvdy.21606. PMID 18624285.
- Rothenburger M, Völker W, Vischer P, Glasmacher B, Scheld HH, Deiwick M (December 2002). "Ultrastructure of proteoglycans in tissue-engineered cardiovascular structures". Tissue Eng. 8 (6): 1049–56. doi:10.1089/107632702320934146. PMID 12542950.
- Ohji M, SundarRaj N, Hassell JR, Thoft RA (February 1994). "Basement membrane synthesis by human corneal epithelial cells in vitro". Invest. Ophthalmol. Vis. Sci. 35 (2): 479–85. PMID 8112997.
- Pradhan S, Zhang C, Jia X, Carson D, Witt RL, Farach-Carson MC (April 2009). "Perlecan domain IV peptide stimulates salivary gland cell assembly in vitro". Tissue Eng Part A 15 (11): 090421090144067. doi:10.1089/ten.TEA.2008.0669. PMC 2792055. PMID 19382872.
- Cohen IR, Murdoch AD, Naso MF, Marchetti D, Berd D, Iozzo RV (November 1994). "Abnormal expression of perlecan proteoglycan in metastatic melanomas". Cancer Res. 54 (22): 5771–4. PMID 7954396.
- Marchetti D, Menter D, Jin L, Nakajima M, Nicolson GL (October 1993). "Nerve growth factor effects on human and mouse melanoma cell invasion and heparanase production". Int. J. Cancer 55 (4): 692–9. doi:10.1002/ijc.2910550430. PMID 8407001.
- Davies EJ, Blackhall FH, Shanks JH, David G, McGown AT, Swindell R, Slade RJ, Martin-Hirsch P, Gallagher JT, Jayson GC (August 2004). "Distribution and clinical significance of heparan sulfate proteoglycans in ovarian cancer". Clin. Cancer Res. 10 (15): 5178–86. doi:10.1158/1078-0432.CCR-03-0103. PMID 15297422.
- Kodama J, Shinyo Y, Hasengaowa, Kusumoto T, Seki N, Nakamura K, Hongo A, Hiramatsu Y (July 2005). "Loss of basement membrane heparan sulfate expression is associated with pelvic lymph node metastasis in invasive cervical cancer". Oncol. Rep. 14 (1): 89–92. PMID 15944773.
- Jiang X, Multhaupt H, Chan E, Schaefer L, Schaefer RM, Couchman JR (December 2004). "Essential contribution of tumor-derived perlecan to epidermal tumor growth and angiogenesis". J. Histochem. Cytochem. 52 (12): 1575–90. doi:10.1369/jhc.4A6353.2004. PMID 15557212.
- Sharma B, Handler M, Eichstetter I, Whitelock JM, Nugent MA, Iozzo RV (October 1998). "Antisense targeting of perlecan blocks tumor growth and angiogenesis in vivo". J. Clin. Invest. 102 (8): 1599–608. doi:10.1172/JCI3793. PMC 509011. PMID 9788974.
- Aviezer D, Iozzo RV, Noonan DM, Yayon A (April 1997). "Suppression of autocrine and paracrine functions of basic fibroblast growth factor by stable expression of perlecan antisense cDNA". Mol. Cell. Biol. 17 (4): 1938–46. PMC 232040. PMID 9121441.
- Marchisone C, Del Grosso F, Masiello L, Prat M, Santi L, Noonan DM (2000). "Phenotypic alterations in Kaposi's sarcoma cells by antisense reduction of perlecan". Pathol. Oncol. Res. 6 (1): 10–7. doi:10.1007/BF03032652. PMID 10749582.
- Mathiak M, Yenisey C, Grant DS, Sharma B, Iozzo RV (June 1997). "A role for perlecan in the suppression of growth and invasion in fibrosarcoma cells". Cancer Res. 57 (11): 2130–6. PMID 9187109.
- Mongiat M, Sweeney SM, San Antonio JD, Fu J, Iozzo RV (February 2003). "Endorepellin, a novel inhibitor of angiogenesis derived from the C terminus of perlecan". J. Biol. Chem. 278 (6): 4238–49. doi:10.1074/jbc.M210445200. PMID 12435733.
- Savorè C, Zhang C, Muir C, Liu R, Wyrwa J, Shu J, Zhau HE, Chung LW, Carson DD, Farach-Carson MC (2005). "Perlecan knockdown in metastatic prostate cancer cells reduces heparin-binding growth factor responses in vitro and tumor growth in vivo". Clin. Exp. Metastasis 22 (5): 377–90. doi:10.1007/s10585-005-2339-3. PMID 16283481.
- Conde-Knape K (2001). "Heparan sulfate proteoglycans in experimental models of diabetes: a role for perlecan in diabetes complications". Diabetes Metab. Res. Rev. 17 (6): 412–21. doi:10.1002/dmrr.236. PMID 11757076.
- Pillarisetti S (2000). "Lipoprotein modulation of subendothelial heparan sulfate proteoglycans (perlecan) and atherogenicity". Trends Cardiovasc. Med. 10 (2): 60–5. doi:10.1016/S1050-1738(00)00048-7. PMID 11150731.
- Segev A, Nili N, Strauss BH (2004). "The role of perlecan in arterial injury and angiogenesis". Cardiovasc. Res. 63 (4): 603–10. doi:10.1016/j.cardiores.2004.03.028. PMID 15306215.
- Wasty F, Alavi MZ, Moore S (April 1993). "Distribution of glycosaminoglycans in the intima of human aortas: changes in atherosclerosis and diabetes mellitus". Diabetologia 36 (4): 316–22. doi:10.1007/BF00400234. PMID 8477876.
- Vogl-Willis CA, Edwards IJ (April 2004). "High-glucose-induced structural changes in the heparan sulfate proteoglycan, perlecan, of cultured human aortic endothelial cells". Biochim. Biophys. Acta 1672 (1): 36–45. doi:10.1016/j.bbagen.2004.02.005. PMID 15056491.
- Tamsma JT, van den Born J, Bruijn JA, Assmann KJ, Weening JJ, Berden JH, Wieslander J, Schrama E, Hermans J, Veerkamp JH (March 1994). "Expression of glomerular extracellular matrix components in human diabetic nephropathy: decrease of heparan sulphate in the glomerular basement membrane". Diabetologia 37 (3): 313–20. doi:10.1007/BF00398060. PMID 8174847.
- van Det NF, van den Born J, Tamsma JT, Verhagen NA, Berden JH, Bruijn JA, Daha MR, van der Woude FJ (April 1996). "Effects of high glucose on the production of heparan sulfate proteoglycan by mesangial and epithelial cells". Kidney Int. 49 (4): 1079–89. doi:10.1038/ki.1996.157. PMID 8691728.
- Olsson U, Bondjers G, Camejo G (March 1999). "Fatty acids modulate the composition of extracellular matrix in cultured human arterial smooth muscle cells by altering the expression of genes for proteoglycan core proteins". Diabetes 48 (3): 616–22. doi:10.2337/diabetes.48.3.616. PMID 10078565.
- Yamamoto C, Wakata T, Fujiwara Y, Kaji T (February 2005). "Induction of synthesis of a large heparan sulfate proteoglycan, perlecan, by thrombin in cultured human coronary smooth muscle cells". Biochim. Biophys. Acta 1722 (1): 92–102. doi:10.1016/j.bbagen.2004.11.017. PMID 15716125.
- Shimizu-Hirota R, Sasamura H, Mifune M, Nakaya H, Kuroda M, Hayashi M, Saruta T (December 2001). "Regulation of vascular proteoglycan synthesis by angiotensin II type 1 and type 2 receptors". J. Am. Soc. Nephrol. 12 (12): 2609–15. PMID 11729229.
- Hopf M, Göhring W, Mann K, Timpl R (August 2001). "Mapping of binding sites for nidogens, fibulin-2, fibronectin and heparin to different IG modules of perlecan". J. Mol. Biol. 311 (3): 529–41. doi:10.1006/jmbi.2001.4878. PMID 11493006.
- Sasaki T, Göhring W, Pan TC, Chu ML, Timpl R (December 1995). "Binding of mouse and human fibulin-2 to extracellular matrix ligands". J. Mol. Biol. 254 (5): 892–9. doi:10.1006/jmbi.1995.0664. PMID 7500359.
- Mongiat M, Taylor K, Otto J, Aho S, Uitto J, Whitelock JM, Iozzo RV (March 2000). "The protein core of the proteoglycan perlecan binds specifically to fibroblast growth factor-7". J. Biol. Chem. 275 (10): 7095–100. doi:10.1074/jbc.275.10.7095. PMID 10702276.
- Mongiat M, Otto J, Oldershaw R, Ferrer F, Sato JD, Iozzo RV (March 2001). "Fibroblast growth factor-binding protein is a novel partner for perlecan protein core". J. Biol. Chem. 276 (13): 10263–71. doi:10.1074/jbc.M011493200. PMID 11148217.
- Smeland S, Kolset SO, Lyon M, Norum KR, Blomhoff R (September 1997). "Binding of perlecan to transthyretin in vitro". Biochem. J. 326 (3): 829–36. PMC 1218739. PMID 9307034.