scholarly journals High Glucose Stimulates Proliferation and Collagen Type I Synthesis in Renal Cortical Fibroblasts

1999 ◽  
Vol 10 (9) ◽  
pp. 1891-1899 ◽  
Author(s):  
DONG CHEOL HAN ◽  
MOTOHIDE ISONO ◽  
BRENDA B. HOFFMAN ◽  
FUAD N. ZIYADEH

Abstract. Renal tubular epithelial cells and interstitial fibroblasts are active participants in tubulointerstitial fibrosis, the best correlate of decreased glomerular filtration in diabetic nephropathy. It was reported previously that high ambient glucose stimulates transforming growth factor-β (TGF-β) mRNA and bioactivity, promotes cellular hypertrophy, and increases collagen synthesis in proximal tubular cells. This study evaluates the effects of high glucose and TGF-β on the behavior of murine renal cortical fibroblasts (TFB) in culture. High glucose (450 mg/dl) significantly increased [3H]-thymidine incorporation (by 60 to 80% after 24 to 72 h) and cell number, without significantly increasing cell death when compared with normal glucose (100 mg/dl). There also was a transient increase in the mRNA of the c-mycandegr-1early-response genes. Exogenous TGF-β1 was promitogenic rather than antiproliferative in contrast to other renal cell types. Northern blot analysis demonstrated constitutive expression of TGF-β1, -β2, and -β3 transcripts. Exposure to high glucose increased all three TGF-β isoforms in a time-dependent manner. High glucose as well as exogenous TGF-β1 also increased [3H]-proline incorporation, α2(I) collagen mRNA, and type I collagen protein (measured by immunoassay). Treatment with a neutralizing pan-selective monoclonal anti-TGF-β antibody markedly attenuated the stimulation by high ambient glucose of thymidine incorporation, TGF-β1 mRNA, and type I collagen mRNA and protein levels. It is concluded that high ambient glucose and exogenous TGF-β1 share similar actions on renal fibroblasts. Moreover, the stimulation of cell proliferation and collagen type I synthesis in these cells by high ambient glucose are mediated by activation of an autocrine TGF-β system.

Author(s):  
Guoguang Yang ◽  
Richard C. Crawford ◽  
James H.-C. Wang

This study investigated the effect of cyclic mechanical stretching on the collagen gene expression and protein synthesis of human patellar tendon fibroblasts (HPTFs). We hypothesized that cyclic mechanical stretching of HPTFs would increase collagen synthesis via transforming growth factor-beta 1 (TGF-β1). To test the hypothesis, the tendon fibroblasts were cultured on microgrooved surfaces of silicone dishes under serum-free conditions. The cells were subjected to cyclic uniaxial stretching with a constant frequency and duration (0.5Hz, 4hr), and one of three stretching magnitudes (no stretch, 4%, and 8%) followed by 4 hours of rest. It was found that the gene and protein expression of both collagen type I and TGF-β1 were significantly increased in a stretching-magnitude dependent manner, whereas collagen type III gene and protein levels were not significantly changed. The exogenous addition of antibody to TGF-β1 eliminated the stretching-induced increase in collagen type I protein synthesis. The results therefore confirmed our working hypothesis and suggest that mechanical stretching of tendon fibroblasts can lead to matrix remodeling by modulating the collagen production of tendon fibroblasts, a process at least particially mediated by TGF-β1.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1094.1-1094
Author(s):  
A. S. Siebuhr ◽  
P. Juhl ◽  
M. Karsdal ◽  
A. C. Bay-Jensen

Background:Interleukin 6 (IL-6) is known to have both pro- and anti-inflammatory properties, depending on the receptor activation. The classical IL-6 signaling via the membrane bound receptor is mainly anti-inflammatory, whereas signaling through the soluble receptor (sIL-6R) is pro-inflammatory/pro-fibrotic. However, the direct fibrotic effect of IL-6 stimulation on dermal fibroblasts is unknown.Objectives:We investigated the fibrotic effect of IL-6 + sIL-6R in a dermal fibroblast model and assessed fibrosis by neo-epitope biomarkers of extracellular matrix proteins.Methods:Primary healthy human dermal fibroblasts were grown for up to 17 days in DMEM medium with 0.4% fetal calf serum, ficoll (to produce a crowded environment) and ascorbic acid. IL-6 [1-90 nM]+sIL-6R [0.1-9 nM] alone or in combination with TGFβ [1 nM] were tested in three different donors. TGFβ [1 nM], PDGF-AB [3 nM] and non-stimulated cells (w/o) were used as controls. Tocilizumab (TCZ) with TGFβ + IL-6 + sIL-6R stimulation was tested in one donor. Collagen type I, III and VI formation (PRO-C1, PRO-C3 and PRO-C6) and fibronectin (FBN-C) were evaluated by validated ELISAs (Nordic Bioscience). Western blot analysis investigated signal cascades. Gene expression of selected ECM proteins was analyzed. Statistical analyses included One-way and 2-way ANOVA and area under the curve analysis.Results:formation by the end of the culture period. The fibronectin and collagen type VI signal were consistent between the three tested donors, whereas the formation of type III collagen was only increased in one donor, but in several trials. Type I collagen formation was unchanged by IL-6 + sIL-6R stimulation. The gene expression of type I collagen was induced by IL-6 + sIL-6R. Western blot analysis validated trans-signaling by the IL-6+sIL-6R stimulation as expected.IL-6 + sIL-6R stimulation in combination with TGFβ decreased fibronectin levels compared to TGFβ alone but did not reach the level of unstimulated fibroblasts. The formation of collagen type IV was generally unchanged with IL-6 + sIL-6R + TGFβ compared to TGFβ alone. Collagen type I and III formation was more scattered in the signals when IL-6 + sIL-6R was in combination with TGFβ, as the biomarker level could be either decreased or increased compared to TGFβ alone. In two studies the type I collagen level was synergistic increased by IL-6 + sIL-6R + TGFβ, whereas another study found the level to be decreased compared to TGFβ alone. The gene expression of fibronectin and type I collagen was increased with TGFβ +IL-6+sIL-6R compared to TGFβ alone.Inhibition of IL-6R by TCZ in combination with IL-6 + sIL-6R did only decrease the fibronectin level with the lowest TCZ concentration (p=0.03). TCZ alone decreased the fibronectin level in a dose-dependent manner (One-way ANOVA p=0.0002).Conclusion:We investigated the fibrotic response of dermal fibroblasts to IL-6 + sIL-6R stimulation. IL-6 modulated the fibronectin level and modulated the collagen type III formation level in a somewhat dose-dependent manner. In combination with TGFβ, IL-6 decreased collagen type I and IV formation and fibronectin. However, in this study inhibition of IL-6R by TCZ did not change the fibrotic response of the dermal fibroblasts. This study indicated that IL-6 did not induce collagen formation in dermal fibroblasts, except type III collagen formation with high IL-6 concentration.Figure:Disclosure of Interests:Anne Sofie Siebuhr Employee of: Nordic Bioscience, Pernille Juhl Employee of: Nordic Bioscience, Morten Karsdal Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee at Nordic Bioscience A/S., Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S.


Parasitology ◽  
2007 ◽  
Vol 134 (11) ◽  
pp. 1611-1621 ◽  
Author(s):  
D. CHU ◽  
Q. LUO ◽  
C. LI ◽  
Y. GAO ◽  
L. YU ◽  
...  

SUMMARYThe main pathological characteristics of hepatic fibrosis in schistosomiasis are the proliferation of hepatic stellate cells (HSCs) and the deposition of collagen type I (Col I) and collagen type III (Col III). Transforming growth factor beta-1 (TGF-β1) plays an important role in hepatic fibrosis. Paeoniflorin (PAE) has been reported to have immunoregulatory effects; however, the mechanism of its anti-hepatic fibrosis inS. japonicumhas not been elucidated. In the present study, we found that mouse peritoneal macrophages (PMφs) stimulated by soluble egg antigen (SEA) ofS. japonicumcould secrete TGF-β1, and the TGF-β1 in the peritoneal macrophage-conditioned medium (PMCM) could induce proliferation of HSCs and secretion of Col I and III. We selected PMCM at 1:2 dilution as the optimum PMCM (OPMCM). Then we treated HSCs pre-incubated with OPMCM with PAE, and found that the inhibition of HSC proliferation or Col I and III production were closely correlated with the concentration of PAE. Further investigation found that PAE significantly decreased the Smad3 transcription and phosphorylation in HSCs stimulated by OPMCM. In conclusion, SEA plays a key role in hepatic fibrosis by inducing TGF-β1 from PMφs. PAE can exert anti-fibrogenic effects by inhibiting HSCs proliferation and down-regulating Smad3 expression and phosphorylation through TGF-β1 signalling.


2006 ◽  
Vol 74 (11) ◽  
pp. 6356-6364 ◽  
Author(s):  
Angela S. Barbosa ◽  
Patricia A. E. Abreu ◽  
Fernanda O. Neves ◽  
Marina V. Atzingen ◽  
Mônica M. Watanabe ◽  
...  

ABSTRACT Pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. Several pathogens, including spirochetes, have been shown to express surface proteins that interact with the extracellular matrix (ECM). This adhesin-mediated binding process seems to be a crucial step in the colonization of host tissues. This study examined the interaction of putative leptospiral outer membrane proteins with laminin, collagen type I, collagen type IV, cellular fibronectin, and plasma fibronectin. Six predicted coding sequences selected from the Leptospira interrogans serovar Copenhageni genome were cloned, and proteins were expressed, purified by metal affinity chromatography, and characterized by circular dichroism spectroscopy. Their capacity to mediate attachment to ECM components was evaluated by binding assays. We have identified a leptospiral protein encoded by LIC12906, named Lsa24 (leptospiral surface adhesin; 24 kDa) that binds strongly to laminin. Attachment of Lsa24 to laminin was specific, dose dependent, and saturable. Laminin oxidation by sodium metaperiodate reduced the protein-laminin interaction in a concentration-dependent manner, indicating that laminin sugar moieties are crucial for this interaction. Triton X-114-solubilized extract of L. interrogans and phase partitioning showed that Lsa24 was exclusively in the detergent phase, indicating that it is a component of the leptospiral membrane. Moreover, Lsa24 partially inhibited leptospiral adherence to immobilized laminin. This newly identified membrane protein may play a role in mediating adhesion of L. interrogans to the host. To our knowledge, this is the first leptospiral adhesin with laminin-binding properties reported to date.


2007 ◽  
Vol 292 (4) ◽  
pp. C1361-C1369 ◽  
Author(s):  
Rangnath Mishra ◽  
Ling Zhu ◽  
Richard L. Eckert ◽  
Michael S. Simonson

Transforming growth factor-β (TGF-β) stimulates myofibroblast transdifferentiation, leading to type I collagen accumulation and fibrosis. We investigated the function of Src in TGF-β-induced collagen I accumulation. In human mesangial cells, PTyr416 Src (activated Src) was 3.3-fold higher in TGF-β-treated cells than in controls. Src activation by TGF-β was blocked by rottlerin and by a dominant negative mutant of protein kinase Cδ (PKCδ), showing that TGF-β activates Src by a PKCδ-based mechanism. Pharmacological inhibitors and a dominant negative Src mutant prevented the increase in collagen type I secretion in cells exposed to TGF-β. Similarly, on-target Src small interference RNA (siRNA) prevented type I collagen secretion in response to TGF-β, but off-target siRNA complexes had no effect. It is well established in mesangial cells that upregulation of type I collagen by TGF-β requires extracellular signal-regulated kinase 1/2 (ERK1/2), and we found that activation of ERK1/2 by TGF-β requires Src. In conclusion, these results suggest that stimulation of collagen type I secretion by TGF-β requires a PKCδ-Src-ERK1/2 signaling motif.


2021 ◽  
Vol 23 (1) ◽  
pp. 91
Author(s):  
Tomasz P. Lehmann ◽  
Urszula Guderska ◽  
Klaudia Kałek ◽  
Maria Marzec ◽  
Agnieszka Urbanek ◽  
...  

This article describes several recent examples of miRNA governing the regulation of the gene expression involved in bone matrix construction. We present the impact of miRNA on the subsequent steps in the formation of collagen type I. Collagen type I is a main factor of mechanical bone stiffness because it constitutes 90–95% of the organic components of the bone. Therefore, the precise epigenetic regulation of collagen formation may have a significant influence on bone structure. We also describe miRNA involvement in the expression of genes, the protein products of which participate in collagen maturation in various tissues and cancer cells. We show how non-collagenous proteins in the extracellular matrix are epigenetically regulated by miRNA in bone and other tissues. We also delineate collagen mineralisation in bones by factors that depend on miRNA molecules. This review reveals the tissue variability of miRNA regulation at different levels of collagen maturation and mineralisation. The functionality of collagen mRNA regulation by miRNA, as proven in other tissues, has not yet been shown in osteoblasts. Several collagen-regulating miRNAs are co-expressed with collagen in bone. We suggest that collagen mRNA regulation by miRNA could also be potentially important in bone metabolism.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shichao Lv ◽  
Qiang Wang ◽  
Meifang Wu ◽  
Meng Li ◽  
Xiaojing Wang ◽  
...  

Pressure-overloaded myocardial hypertrophy is an independent risk factor for various cardiovascular diseases (CVDs), such as heart failure (HF), arrhythmia, and even sudden death. It is reported that QiShenYiQi pill (QSYQ) is widely used in the treatment of CVDs and can prevent pathological hypertrophy of myocardium, but its specific mechanism is still unclear. In this study, a rat model of myocardial hypertrophy was established through the pressure overload caused by abdominal aortic constriction in Wistar rats. The rats were randomly divided into model group, valsartan group, and QSYQ group, and sham-operated animals served as the control group. At the 4 and 8 weeks of intervention, the general morphology of the heart, myocardial collagen content, collagen volume factor (CVF), collagen type I, collagen type III, myocardial pathological changes, and the expression of ANP, β-MHC, TGF-β1, and CTGF were analyzed, respectively, in order to explore the possible effect of QSYQ on the mechanism of myocardial hypertrophy. We observed that QSYQ could effectively improve myocardial hypertrophy in pressure-overloaded rats, which was related to the regulatory mechanism of TGF-β1 and CTGF.


2016 ◽  
Vol 10 (5-6) ◽  
pp. 175 ◽  
Author(s):  
Premsant Sangkum ◽  
Faysal A. Yafi ◽  
Hogyoung Kim ◽  
Mostafa Bouljihad ◽  
Manish Ranjan ◽  
...  

Introduction: We sought to evaluate the therapeutic effect of adipose tissue-derived stem cells (ADSCs) in a rat model of urethral fibrosis.Methods: Eighteen (18) male Sprague-Dawley rats (300‒350 g) were divided into three groups: (1) sham (saline injection); (2) urethral fibrosis group (10 μg transforming growth factor beta 1 (TGF-β1) injection); and (3) ADSCs group (10 μg TGF-β1 injection plus 2 x 105 ADSCs). Rat ADSCs were harvested from rat inguinal fat pads. All study animals were euthanized at two weeks afterurethral injection. Following euthanasia, rat urethral tissue was were quantitated by Western blot analysis. Results: TGF-β1 injection induced significant urethral fibrosis and increased collagen type I and III expression (p<0.05). Significant decrease in submucosal fibrosis and collagen type I and III expression were noted in the ADSCs group compared with the urethral fibrosis group (p<0.05). TGF-β1 induced fibrotic changes were ameliorated by injection of ADSCs.Conclusions: Local injection of ADSCs in a rat model of urethral fibrosis significantly decreased collagen type I and III. These findings suggest that ADSC injection may prevent scar formation and potentially serve as an adjunct treatment to increase the success rate of primary treatment for urethral stricture disease. Further animal and clinical studies are needed to confirm these results.


2009 ◽  
Vol 297 (5) ◽  
pp. L864-L870 ◽  
Author(s):  
Weichao Guo ◽  
Bin Shan ◽  
Ross C. Klingsberg ◽  
Xiangmei Qin ◽  
Joseph A. Lasky

Idiopathic pulmonary fibrosis (IPF) is a devastating disease with no known effective pharmacological therapy. The fibroblastic foci of IPF contain activated myofibroblasts that are the major synthesizers of type I collagen. Transforming growth factor (TGF)-β1 promotes differentiation of fibroblasts into myofibroblasts in vitro and in vivo. In the current study, we investigated the molecular link between TGF-β1-mediated myofibroblast differentiation and histone deacetylase (HDAC) activity. Treatment of normal human lung fibroblasts (NHLFs) with the pan-HDAC inhibitor trichostatin A (TSA) inhibited TGF-β1-mediated α-smooth muscle actin (α-SMA) and α1 type I collagen mRNA induction. TSA also blocked the TGF-β1-driven contractile response in NHLFs. The inhibition of α-SMA expression by TSA was associated with reduced phosphorylation of Akt, and a pharmacological inhibitor of Akt blocked TGF-β1-mediated α-SMA induction in a dose-dependent manner. HDAC4 knockdown was effective in inhibiting TGF-β1-stimulated α-SMA expression as well as the phosphorylation of Akt. Moreover, the inhibitors of protein phosphatase 2A and 1 (PP2A and PP1) rescued the TGF-β1-mediated α-SMA induction from the inhibitory effect of TSA. Together, these data demonstrate that the differentiation of NHLFs to myofibroblasts is HDAC4 dependent and requires phosphorylation of Akt.


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