Gamma-Tocotrienol Stimulates the Proliferation, Differentiation, and Mineralization in Osteoblastic MC3T3-E1 Cells

Gamma-tocotrienol, a major component of tocotrienol-rich fraction of palm oil, has been suggested to exhibit bone protective effectsin vivo. However, the effects ofγ-tocotrienol on osteoblast cells are still unclear. In this study, the effects ofγ-tocotrienol on the proliferation, differentiation, and mineralization in osteoblastic MC3T3-E1 cells were investigated. Our results showed thatγ-tocotrienol (2–8 μmol/L) significantly improved the cell proliferation (p<0.05), but it did not affect cell cycle progression.γ-Tocotrienol significantly increased alkaline phosphatase (ALP) activity (p<0.05), secretion levels of osteocalcin (OC) and osteonectin (ON), and mRNA levels of collagen type I (Col I) of MC3T3-E1 cells. Meanwhile, we found thatγ-tocotrienol is promoted in differentiation MC3T3-E1 cells by upregulation of the expression of Runx2 protein. Moreover, the number of bone nodules increased over 2.5-fold in cells treated withγ-tocotrienol (2–8 μmol/L) for 24 d compared to control group. These results indicated thatγ-tocotrienol at low dose levels, especially 4 μmol/L, could markedly enhance the osteoblastic function by increasing the proliferation, differentiation, and mineralization of osteoblastic MC3T3-E1 cells. Moreover, our data also indicated that Runx2 protein may be involved in these effects. Further studies are needed to determine the potential ofγ-tocotrienol as an antiosteoporotic agent.

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Arginine promotes porcine type I muscle fibres formation through improvement of mitochondrial biogenesis

British Journal Of Nutrition ◽

10.1017/s000711451900309x ◽

2019 ◽

Vol 123 (5) ◽

pp. 499-507 ◽

Cited By ~ 1

Author(s):

Xiaoling Chen ◽

Xiaoming Luo ◽

Daiwen Chen ◽

Bing Yu ◽

Jun He ◽

...

Keyword(s):

Mitochondrial Biogenesis ◽

Basal Diet ◽

Sirtuin 1 ◽

Control Group ◽

Muscle Fibres ◽

Type I ◽

Mrna Levels ◽

Nuclear Respiratory Factor

AbstractThe present study aimed to investigate whether arginine (Arg) promotes porcine type I muscle fibres formation via improving mitochondrial biogenesis. In the in vivo study, a total of sixty Duroc × Landrace × Yorkshire weaning piglets with an average body weight of 6·55 (sd 0·36) kg were randomly divided into four treatments and fed with a basal diet or a basal diet supplemented with 0·5, 1·0 and 1·5 % l-Arg, respectively, in a 4-week trial. Results showed that dietary supplementation of 1·0 % Arg significantly enhanced the activity of succinate dehydrogenase, up-regulated the protein expression of myosin heavy chain I (MyHC I) and increased the mRNA levels of MyHC I, troponin I1, C1 and T1 (Tnni1, Tnnc1 and Tnnt1) in longissimus dorsi muscle compared with the control group. In addition, ATPase staining analysis indicated that 1·0 % Arg supplementation significantly increased the number of type I muscle fibres and significantly decreased the number of type II muscle fibres. Furthermore, 1·0 % Arg supplementation significantly up-regulated PPAR-γ coactivator-1α (PGC-1α), sirtuin 1 and cytochrome c (Cytc) protein expressions, increased PGC-1α, nuclear respiratory factor 1 (NRF1), mitochondria transcription factor B1 (TFB1M), Cytc and ATP synthase subunit C1 (ATP5G) mRNA levels and increased mitochondrial DNA content. In the in vitro study, mitochondrial complex I inhibitor rotenone (Rot) was used. We found that Rot annulled Arg-induced type I muscle fibres formation. Together, our results provide for the first time the evidence that Arg promotes porcine type I muscle fibres formation through improvement of mitochondrial biogenesis.

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Buyang Huanwu Decoction Ameliorates Bleomycin-Induced Pulmonary Fibrosis in Rats via Downregulation of Related Protein and Gene Expression

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2018/9185485 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8

Author(s):

Xuan Wang ◽

Xia Li ◽

Li-na Wang ◽

Jing-juan Pan ◽

Xue Yang ◽

...

Keyword(s):

Pulmonary Fibrosis ◽

Protein Level ◽

Collagen Type ◽

Collagen Type I ◽

Control Group ◽

Type I ◽

Mrna Levels ◽

Collagen Types ◽

Buyang Huanwu Decoction ◽

Serum Collagen

Little is known about the effects of Buyang Huanwu decoction on pulmonary fibrosis. Herein, 144 healthy SD rats were randomly divided into six groups: blank control group (B), model control group (M), positive medicine control group (Mp), and high-, moderate-, and low-dose Buyang Huanwu decoction groups (Hd, Md, and Ld). A pulmonary fibrosis model was established by endotracheal injection of bleomycin. On the second day of modeling, the corresponding saline, methylprednisolone suspension, and the three doses of Buyang Huanwu decoction were used to treat the 6 groups of rats by intragastric administration for 7, 14, and 28 consecutive days. After 7, 14, and 28 days of treatment, the mRNA expression of CTGF and AKT, the protein level of CTGF, p-AKT, and collagen types I and III were tested. Finally, we found that the serum collagen type I and III level in Hd, Md, and Ld rats on the 14th and 28th day and the collagen type I and III level in Hd rats on 7th day were significantly lower than in M rats (P<0.01). The protein level of p-AKT and CTGF in Hd and Md rats on the 7th and 14th days and the protein level of p-AKT in Hd rats on the 28th day were lower than in M rats (P<0.01, P<0.05). The level of CTGF mRNA in Hd, Md, and Ld rats and the level of AKT mRNA in Hd and Md rats on the 7th, 14th, and 28th days and the expression level of AKT mRNA in Ld rats on the 14th and 28th days were significantly lower than in M rats (P<0.01). The study suggests that Buyang Huanwu decoction alleviated pulmonary fibrosis of rats by improvement of lung tissue morphology, low level of serum collagen types I and III, and the reduced expression of CTGF and p-AKT protein, which might be a result of its downregulated expression of CTGF and AKT mRNA levels.

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Collagen-Based Electrospun Materials for Tissue Engineering: A Systematic Review

Bioengineering ◽

10.3390/bioengineering8030039 ◽

2021 ◽

Vol 8 (3) ◽

pp. 39

Author(s):

Britani N. Blackstone ◽

Summer C. Gallentine ◽

Heather M. Powell

Keyword(s):

Systematic Review ◽

Tissue Engineering ◽

Collagen Type I ◽

The Body ◽

Pool Data ◽

Type I ◽

High Concentrations ◽

Increased Strength

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.

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MicroRNA-513b-5p targets COL1A1 and COL1A2 associated with the formation and rupture of intracranial aneurysm

Scientific Reports ◽

10.1038/s41598-021-94116-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Zheng Zheng ◽

Yan Chen ◽

Yinzhou Wang ◽

Yongkun Li ◽

Qiong Cheng

Keyword(s):

Cell Death ◽

Intracranial Aneurysm ◽

Luciferase Reporter Assay ◽

Luciferase Reporter ◽

Control Group ◽

Type I ◽

Mrna Levels ◽

Reporter Assay ◽

Over Expression ◽

Tnf Α

AbstractCollagen-type I alpha 1 chain (COL1A1) and COL1A2 are abnormally expressed in intracranial aneurysm (IA), but their mechanism of action remains unclear. This study was performed to investigate the mechanism of COL1A1 and COL1A2 affecting the occurrence and rupture of IA. Quantitative real-time polymerase chain reaction was used to measure the expression of hsa-miR-513b-5p, COL1A1, COL1A2, TNF-α, IL-6, MMP2, MMP3, MMP9 and TIMP4 in patients with ruptured IA (RA) (n = 100), patients with un-ruptured IA (UA) (n = 100), and controls (n = 100). Then, human vascular smooth muscle cells (HASMCs) were cultured, and dual luciferase reporter assay was performed to analyse the targeting relationship between miR-513b-5p and COL1A1 or COL1A2. The effects of the miR-513b-5p mimic and inhibitor on the proliferation, apoptosis, and death of HASMC and the RIP1-RIP3-MLKL and matrix metalloproteinase pathways were also explored. The effect of silencing and over-expression of COL1A1 and COL1A2 on the role of miR-513b-5p were also evaluated. Finally, the effects of TNF-α on miR-513b-5p targeting COL1A1 and COL1A2 were tested. Compared with those in the control group, the serum mRNA levels of miR-513b-5p, IL-6 and TIMP4 were significantly decreased in the RA and UA groups, but COL1A1, COL1A2, TNF-α, IL-1β, MMP2, MMP3 and MMP9 were significantly increased (p < 0.05). Compared with those in the UA group, the expression of COL1A1, COL1A2, TNF-α, IL-1β and MMP9 was significantly up-regulated in the RA group (p < 0.05). Results from the luciferase reporter assay showed that COL1A1 and COL1A were the direct targets of miR-513b-5p. Further studies demonstrated that miR-513b-5p targeted COL1A1/2 to regulate the RIP1-RIP3-MLKL and MMP pathways, thereby enhancing cell death and apoptosis. Over-expression of COL1A1 or COL1A2, rather than silencing COL1A1/2, could improve the inhibitory effect of miR-513b-5p on cell activity by regulating the RIP1-RIP3-MLKL and MMP pathways. Furthermore, over-expression of miR-513b-5p and/or silencing COL1A1/2 inhibited the TNF-α-induced cell proliferation and enhanced the TNF-α-induced cell death and apoptosis. The mechanism may be related to the inhibition of collagen I and TIMP4 expression and promotion of the expression of RIP1, p-RIP1, p-RIP3, p-MLKL, MMP2 and MMP9. MiR-513b-5p targeted the inhibition of COL1A1/2 expression and affected HASMC viability and extracellular mechanism remodelling by regulating the RIP1-RIP3-MLKL and MMP pathways. This process might be involved in the formation and rupture of IA.

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Properties of a bovine collagen type I membrane for guided bone regeneration applications

e-Polymers ◽

10.1515/epoly-2021-0021 ◽

2021 ◽

Vol 21 (1) ◽

pp. 210-221

Author(s):

Igor S. Brum ◽

Carlos N. Elias ◽

Jorge J. de Carvalho ◽

Jorge L. S. Pires ◽

Mario J. S. Pereira ◽

...

Keyword(s):

Bone Regeneration ◽

Collagen Type ◽

Mechanical Stability ◽

Collagen Type I ◽

Guided Bone Regeneration ◽

Bone Volume ◽

Male Rats ◽

Toxicity Tests ◽

Type I

Abstract Dental implant treatment requires an available bone volume in the implantation site to ensure the implant’s mechanical stability. When the bone volume is insufficient, one must resort to surgical means such as guided bone regeneration (GBR). In GBR surgery, bone grafts and membranes are used. The objective of this work is to manufacture and characterize the in vitro and in vivo properties of resorbable collagen type I membranes (Green Membrane®) for GBR. Membrane surface morphology was characterized by SEM and roughness was measured using an interferometric noncontact 3D system. In vivo skin sensitization and toxicity tests have been performed on Wistar rats. Bone defects were prepared in 24 adult male rats, filled with biomaterials (Blue Bone® and Bio Oss®) and covered with collagen membranes to maintain the mechanical stability of the site for bone regeneration. The incisions were closed with simple stitches; and 60 days after the surgery, the animals were euthanized. Results showed that the analyzed membrane was homogeneous, with collagen fiber webs and open pores. It had no sign of cytotoxicity and the cells at the insertion site showed no bone morphological changes. There was no tissue reaction and no statistical difference between Blue Bone® and Bio Oss® groups. The proposed membrane has no cytotoxicity and displays a biocompatibility profile that makes it suitable for GBR.

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Plant Recombinant Human Collagen Type I Hydrogels for Corneal Regeneration

Regenerative Engineering and Translational Medicine ◽

10.1007/s40883-021-00220-3 ◽

2021 ◽

Author(s):

Michel Haagdorens ◽

Elle Edin ◽

Per Fagerholm ◽

Marc Groleau ◽

Zvi Shtein ◽

...

Keyword(s):

Collagen Type ◽

Collagen Type I ◽

Collagen Fibrils ◽

Type I ◽

Safe Alternative ◽

Human Donor ◽

Human Collagen ◽

Donor Corneas

Abstract Purpose To determine feasibility of plant-derived recombinant human collagen type I (RHCI) for use in corneal regenerative implants Methods RHCI was crosslinked with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to form hydrogels. Application of shear force to liquid crystalline RHCI aligned the collagen fibrils. Both aligned and random hydrogels were evaluated for mechanical and optical properties, as well as in vitro biocompatibility. Further evaluation was performed in vivo by subcutaneous implantation in rats and corneal implantation in Göttingen minipigs. Results Spontaneous crosslinking of randomly aligned RHCI (rRHCI) formed robust, transparent hydrogels that were sufficient for implantation. Aligning the RHCI (aRHCI) resulted in thicker collagen fibrils forming an opaque hydrogel with insufficient transverse mechanical strength for surgical manipulation. rRHCI showed minimal inflammation when implanted subcutaneously in rats. The corneal implants in minipigs showed that rRHCI hydrogels promoted regeneration of corneal epithelium, stroma, and nerves; some myofibroblasts were seen in the regenerated neo-corneas. Conclusion Plant-derived RHCI was used to fabricate a hydrogel that is transparent, mechanically stable, and biocompatible when grafted as corneal implants in minipigs. Plant-derived collagen is determined to be a safe alternative to allografts, animal collagens, or yeast-derived recombinant human collagen for tissue engineering applications. The main advantage is that unlike donor corneas or yeast-produced collagen, the RHCI supply is potentially unlimited due to the high yields of this production method. Lay Summary A severe shortage of human-donor corneas for transplantation has led scientists to develop synthetic alternatives. Here, recombinant human collagen type I made of tobacco plants through genetic engineering was tested for use in making corneal implants. We made strong, transparent hydrogels that were tested by implanting subcutaneously in rats and in the corneas of minipigs. We showed that the plant collagen was biocompatible and was able to stably regenerate the corneas of minipigs comparable to yeast-produced recombinant collagen that we previously tested in clinical trials. The advantage of the plant collagen is that the supply is potentially limitless.

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RUNX2 promotes malignant progression in gastric cancer by regulating COL1A1

Cancer Biomarkers ◽

10.3233/cbm-200472 ◽

2021 ◽

pp. 1-12

Author(s):

Yanlei Li ◽

Ran Sun ◽

Xiulan Zhao ◽

Baocun Sun

Keyword(s):

Gastric Cancer ◽

Human Cancer ◽

Clinical Stage ◽

Collagen Type I ◽

Migration And Invasion ◽

Type I ◽

Aberrant Expression ◽

Invasion And Migration ◽

Protein Levels

BACKGROUND: Runt-related transcription factor 2 (RUNX2) is an important gene that has been implicated in the progression of human cancer. Aberrant expression of RUNX2 predicts gastric cancer (GC) metastasis. However, the molecular mechanism of RUNX2 remains unknown. OBJECTIVE: We hypothesize that RUNX2 promotes GC metastasis by regulating the extracellular matrix component collagen type I alpha 1 (COL1A1). METHODS: The GEPIA database and immunohistochemical staining of 60 GC tissues were used to analyse the correlations between RUNX2 or COL1A1 expression and clinicopathological features, and the Kaplan-Meier method was used to evaluate survival. RT-PCR, western blotting and immunofluorescence were used to detect RUNX2 and COL1A1 expression in GC cells. Migration and invasion assays were performed to assess the influence of RUNX2 and COL1A1 on metastasis. RESULTS: RUNX2 and COL1A1 were highly expressed at both the gene and protein levels in GC, and patients who were positive for RUNX2 and COL1A1 had shorter survival. RUNX2 and COL1A1 expression linearly correlated with each other (r= 0.15, p< 0.01) and with clinical stage and lymph node metastasis (p< 0.05). Overexpressing RUNX2in vitro enhanced COL1A1 expression and promoted GC cell invasion and migration, whereas COL1A1 knockdown inhibited the increase in cell metastatic capacity promoted by RUNX2. In vivo, GC cells overexpressing RUNX2 promoted lung metastasis, and the downregulation of COL1A1 reduced the metastasis promoted by RUNX2. CONCLUSIONS: RUNX2 may promote GC metastasis by regulating COL1A1. RUNX2/COL1A1 can be employed as a novel target for therapy in GC.

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WNT-5A regulates TGF-β-related activities in liver fibrosis

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00160.2016 ◽

2017 ◽

Vol 312 (3) ◽

pp. G219-G227 ◽

Cited By ~ 21

Author(s):

Leonie Beljaars ◽

Sara Daliri ◽

Christa Dijkhuizen ◽

Klaas Poelstra ◽

Reinoud Gosens

Keyword(s):

Liver Fibrosis ◽

Functional Role ◽

Collagen Type ◽

Collagen Type I ◽

Matrix Proteins ◽

Type I ◽

Human Livers

WNT-5A is a secreted growth factor that belongs to the noncanonical members of the Wingless-related MMTV-integration family. Previous studies pointed to a connection between WNT-5A and the fibrogenic factor TGF-β warranting further studies into the functional role of WNT-5A in liver fibrosis. Therefore, we studied WNT-5A expressions in mouse and human fibrotic livers and examined the relation between WNT-5A and various fibrosis-associated growth factors, cytokines, and extracellular matrix proteins. WNT-5A gene and protein expressions were significantly increased in fibrotic mouse and human livers compared with healthy livers. Regression or therapeutic intervention in mice resulted in decreased hepatic WNT-5A levels paralleled by lower collagen levels. Immunohistochemical analysis showed WNT-5A staining in fibrotic septa colocalizing with desmin staining indicating WNT-5A expression in myofibroblasts. In vitro studies confirmed WNT-5A expression in this cell type and showed that TGF-β significantly enhanced WNT-5A expression in contrast to PDGF-BB and proinflammatory cytokines IL-1β and TNF-α. Additionally, TGF-β induces the expression of the WNT receptors FZD2 and FZD8. After silencing of WNT-5A, reduced levels of collagen type I, vimentin, and fibronectin in TGF-β-stimulated myofibroblasts were measured compared with nonsilencing siRNA-treated controls. Interestingly, the antifibrotic cytokine IFNγ suppressed WNT-5A in vitro and in vivo. IFNγ-treated fibrotic mice showed significantly less WNT-5A expression compared with untreated fibrotic mice. In conclusion, WNT-5A paralleled collagen I levels in fibrotic mouse and human livers. WNT-5A expression in myofibroblasts is induced by the profibrotic factor TGF-β and plays an important role in TGF-β-induced regulation of fibrotic matrix proteins, whereas its expression can be reversed upon treatment, both in vitro and in vivo. NEW & NOTEWORTHY This study describes the localization and functional role of WNT-5A in human and mouse fibrotic livers. Hepatic WNT-5A expression parallels collagen type I expression. In vivo and in vitro, the myofibroblasts were identified as the key hepatic cells producing WNT-5A. WNT-5A is under control of TGF-β and its activities are primarily profibrotic.

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Oncofetal Protein CRIPTO Is Involved in Wound Healing and Fibrogenesis in the Regenerating Liver and Is Associated with the Initial Stages of Cardiac Fibrosis

Cells ◽

10.3390/cells10123325 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3325

Author(s):

Sofia Karkampouna ◽

Danny van der Helm ◽

Mario Scarpa ◽

Bart van Hoek ◽

Hein W. Verspaget ◽

...

Keyword(s):

Liver Fibrosis ◽

Mouse Models ◽

Cardiac Fibrosis ◽

Ex Vivo ◽

Pressure Overload ◽

Collagen Type I ◽

Type I ◽

Liver Fibrogenesis ◽

End Stage

Oncofetal protein, CRIPTO, is silenced during homeostatic postnatal life and often re-expressed in different neoplastic processes, such as hepatocellular carcinoma. Given the reactivation of CRIPTO in pathological conditions reported in various adult tissues, the aim of this study was to explore whether CRIPTO is expressed during liver fibrogenesis and whether this is related to the disease severity and pathogenesis of fibrogenesis. Furthermore, we aimed to identify the impact of CRIPTO expression on fibrogenesis in organs with high versus low regenerative capacity, represented by murine liver fibrogenesis and adult murine heart fibrogenesis. Circulating CRIPTO levels were measured in plasma samples of patients with cirrhosis registered at the waitlist for liver transplantation (LT) and 1 year after LT. The expression of CRIPTO and fibrotic markers (αSMA, collagen type I) was determined in human liver tissues of patients with cirrhosis (on a basis of viral hepatitis or alcoholic disease), in cardiac tissue samples of patients with end-stage heart failure, and in mice with experimental liver and heart fibrosis using immuno-histochemical stainings and qPCR. Mouse models with experimental chronic liver fibrosis, induced with multiple shots of carbon tetrachloride (CCl4) and acute liver fibrosis (one shot of CCl4), were evaluated for CRIPTO expression and fibrotic markers. CRIPTO was overexpressed in vivo (Adenoviral delivery) or functionally sequestered by ALK4Fc ligand trap in the acute liver fibrosis mouse model. Murine heart tissues were evaluated for CRIPTO and fibrotic markers in three models of heart injury following myocardial infarction, pressure overload, and ex vivo induced fibrosis. Patients with end-stage liver cirrhosis showed elevated CRIPTO levels in plasma, which decreased 1 year after LT. Cripto expression was observed in fibrotic tissues of patients with end-stage liver cirrhosis and in patients with heart failure. The expression of CRIPTO in the liver was found specifically in the hepatocytes and was positively correlated with the Model for End-stage Liver Disease (MELD) score for end-stage liver disease. CRIPTO expression in the samples of cardiac fibrosis was limited and mostly observed in the interstitial cells. In the chronic and acute mouse models of liver fibrosis, CRIPTO-positive cells were observed in damaged liver areas around the central vein, which preceded the expression of αSMA-positive stellate cells, i.e., mediators of fibrosis. In the chronic mouse models, the fibrosis and CRIPTO expression were still present after 11 weeks, whereas in the acute model the liver regenerated and the fibrosis and CRIPTO expression resolved. In vivo overexpression of CRIPTO in this model led to an increase in fibrotic markers, while blockage of CRIPTO secreted function inhibited the extent of fibrotic areas and marker expression (αSMA, Collagen type I and III) and induced higher proliferation of residual healthy hepatocytes. CRIPTO expression was also upregulated in several mouse models of cardiac fibrosis. During myocardial infarction CRIPTO is upregulated initially in cardiac interstitial cells, followed by expression in αSMA-positive myofibroblasts throughout the infarct area. After the scar formation, CRIPTO expression decreased concomitantly with the αSMA expression. Temporal expression of CRIPTO in αSMA-positive myofibroblasts was also observed surrounding the coronary arteries in the pressure overload model of cardiac fibrosis. Furthermore, CRIPTO expression was upregulated in interstitial myofibroblasts in hearts cultured in an ex vivo model for cardiac fibrosis. Our results are indicative for a functional role of CRIPTO in the induction of fibrogenesis as well as a potential target in the antifibrotic treatments and stimulation of tissue regeneration.

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Alpha-single chains of collagen type VI inhibit the fibrogenic effects of triple helical collagen VI in hepatic stellate cells

PLoS ONE ◽

10.1371/journal.pone.0254557 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0254557

Author(s):

Christian Freise ◽

Hyunho Lee ◽

Christopher Chronowski ◽

Doug Chan ◽

Jessica Cziomer ◽

...

Keyword(s):

Hepatic Stellate Cells ◽

Collagen Type ◽

Stellate Cell ◽

Smooth Muscle Actin ◽

Stellate Cells ◽

Collagen Type I ◽

Serum Starvation ◽

Type I ◽

Linear Peptide

The interaction of extracellular matrix (ECM) components with hepatic stellate cells (HSCs) is thought to perpetuate fibrosis by stimulating signaling pathways that drive HSC activation, survival and proliferation. Consequently, disrupting the interaction between ECM and HSCs is considered a therapeutical avenue although respective targets and underlying mechanisms remain to be established. Here we have interrogated the interaction between type VI collagen (CVI) and HSCs based on the observation that CVI is 10-fold upregulated during fibrosis, closely associates with HSCs in vivo and promotes cell proliferation and cell survival in cancer cell lines. We exposed primary rat HSCs and a rat hepatic stellate cell line (CFSC) to soluble CVI and determined the rate of proliferation, apoptosis and fibrogenesis in the absence of any additional growth factors. We find that CVI in nanomolar concentrations prevents serum starvation-induced apoptosis. This potent anti-apoptotic effect is accompanied by induction of proliferation and acquisition of a pronounced pro-fibrogenic phenotype characterized by increased α-smooth muscle actin, TGF-β, collagen type I and TIMP-1 expression and diminished proteolytic MMP-13 expression. The CVI-HSC interaction can be disrupted with the monomeric α2(VI) and α3(VI) chains and abrogates the activating CVI effects. Further, functional relevant α3(VI)—derived 30 amino acid peptides lead to near-complete inhibition of the CVI effect. In conclusion, CVI serves as a potent mitogen and activating factor for HSCs. The antagonistic effects of the CVI monomeric chains and peptides point to linear peptide sequences that prevent activation of CVI receptors which may allow a targeted antifibrotic therapy.

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