scholarly journals Increased HIF-1α in Knee Osteoarthritis Aggravate Synovial Fibrosis via Fibroblast-Like Synoviocyte Pyroptosis

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Li Zhang ◽  
Li Zhang ◽  
Zhengquan Huang ◽  
Runlin Xing ◽  
Xiaochen Li ◽  
...  

Fibroblast-like synoviocytes (FLSs) are the main effector cells of knee osteoarthritis (KOA) synovial fibrosis. Our last report showed that NLRP1 and NLRP3 inflammasomes may mediate LPS/ATP-induced FLSs pyroptosis in KOA. In the present study, we found an elevated hypoxia-inducible factor-1α (HIF-1α) level in the synovial tissue of KOA model rats, and inhibiting the increase of HIF-1α could improve synovial fibrosis in rats. Subsequently, we established LPS/ATP-induced model in FLSs mimicking the inflammatory environment of KOA. FLSs transfected with siRNA HIF-1α showed a reduced cell death; meanwhile, the relative expression of pyroptosis-related proteins was also downregulated. Additionally, FLSs transfected with or without siRNA GSDMD were exposed to hypoxia. GSDMD silencing can significantly reduce both gene and protein levels of fibrogenic markers transforming growth factor-β (TGF-β), procollagen-lysine, 2-oxoglutarate 5-dioxygenase2 (PLOD2), collagen type I α1 chain (COL1A1), and tissue inhibitor of metalloproteinases 1 (TIMP1). Taken together, our findings indicate that increased HIF-1α is highly involved in the KOA synovial fibrosis. Moreover, elevated HIF-1α may aggravate synovial fibrosis via FLS pyroptosis.

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Wei Cheng ◽  
Fangfang Wang ◽  
Airan Feng ◽  
Xiaodan Li ◽  
Wencheng Yu

Objective. To investigate the role of CXXC5 and the CD40/CD40L pathway in lung fibrosis. Methods. (1) We constructed mouse models of bleomycin-induced pulmonary fibrosis and transfected them with a CXXC5 overexpression vector to evaluate the severity of pulmonary fibrosis. (2) Mouse lung fibroblast (MLF) models stably overexpressed or knockout of CXXC5 vector were constructed. After transforming growth factor-β1 (TGF-β1) stimulation, we examined the proliferation and apoptosis of the MLF model and evaluated the expression of mesenchymal markers and the CXXC5/CD40/CD40L pathway. Results. (1) Compared with other groups, the overexpressed CXXC5 group had less alveolar structure destruction, thinner alveolar septum, and lower Ashcroft score. (2) In bleomycin-induced mice, the expression of CD40 and CD40L increased at both transcriptional and protein levels, and the same changes were observed in α-smooth muscle actin (α-SMA) and collagen type I (Colla I). After upregulation of CXXC5, the increase in CD40, CD40L, α-SMA, and Colla I was attenuated. (3) Stimulated with TGF-β1, MLF proliferation was activated, apoptosis was suppressed, and the expression of CD40, CD40L, α-SMA, and Colla I was increased at both transcriptional and protein levels. After upregulation of CXXC5, these changes were attenuated. Conclusion. CXXC5 inhibits pulmonary fibrosis and transformation to myofibroblasts by negative feedback regulation of the CD40/CD40L pathway.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jun Qian ◽  
Yaqin Xu ◽  
Zhiwei Yu

Background and Objective. While calcitriol can inhibit airway remodeling in asthmatic mice, the mechanism remains unclear. The purpose of this study was to explore the mechanism of action of calcitriol on airway remodeling in asthma and its interaction with budesonide. Methods. A mouse model of asthma was established by allergic sensitization and challenge with ovalbumin. The mice were treated with budesonide, calcitriol, or budesonide plus calcitriol. The expression of airway remodeling-related proteins, transforming growth factor β (TGFβ) signaling pathway-related proteins, the glucocorticoid receptor, and vitamin D receptor (VDR) was determined by immunohistochemical staining and Western blot analysis. Quantitative real-time PCR was used to determine the expression of microRNA-21 (miR-21) in the lung tissue of mice. Results. Monotherapy with budesonide or calcitriol inhibited the high expression of collagen type I protein and upregulated the low expression of Smad7 in asthmatic mice. There was a synergistic interaction between budesonide and calcitriol in combined treatment. The expression of miR-21 in the combined treatment group was significantly lower than that in the calcitriol treatment group. VDR expression in the combined treatment group was significantly higher than that of the calcitriol treatment group. Conclusion. Budesonide and calcitriol have a synergistic effect on airway remodeling in asthmatic mice.


2021 ◽  
pp. 1-12
Author(s):  
Yanlei Li ◽  
Ran Sun ◽  
Xiulan Zhao ◽  
Baocun Sun

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.


Author(s):  
Faten AbdelHafez Ahmed ◽  
Christian Klausen ◽  
Hua Zhu ◽  
Peter C K Leung

Abstract Placental insufficiency disorders are major obstetric complications that share a common phenomenon of poor placental trophoblast cell invasion and remodeling of uterine tissues. Myostatin is a transforming growth factor (TGF)-β superfamily member well-known for its important role in muscle growth control. Myostatin is also produced in the placenta and has been shown to regulate some trophoblast functions. However, its roles in placental development are still poorly understood. In this study, we tested the hypothesis that myostatin increases trophoblast cell invasion by upregulating N-cadherin via SMAD2/3-SMAD4 signaling. Primary and immortalized (HTR8/SVneo) trophoblast cells were used as study models. Matrigel-coated transwell invasion assays were used to study the effects of recombinant human myostatin on trophoblast cell invasion. RT-qPCR and Western blot were used to measure myostatin effects on N-cadherin mRNA and protein levels, respectively. Small inhibitor molecules as well as siRNA-mediated knockdown were used to block myostatin receptor and downstream signaling, respectively. Data were analyzed either by unpaired Student T test or one-way ANOVA followed by Newman Keuls test for multiple group comparisons. Myostatin significantly increased primary and HTR8/SVneo trophoblast cell invasion. Moreover, myostatin upregulated N-cadherin mRNA and protein levels in a time dependent manner in both study models. These effects were blocked by inhibition of TGF-β type I receptors as well as siRNA-mediated knockdown of SMAD2/3 combined or common SMAD4. Importantly, myostatin-induced trophoblast cell invasion was abolished by knockdown of N-cadherin, SMAD2/3 or SMAD4. Myostatin may increase human trophoblast cell invasion by upregulating N-cadherin via SMAD2/3-SMAD4 signaling.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Kevin Morine ◽  
Vikram Paruchuri ◽  
Xiaoying Qiao ◽  
Emily Mackey ◽  
Mark Aronovitz ◽  
...  

Introduction: Activin receptor like kinase 1 (ALK1) mediates signaling via transforming growth factor beta-1 (TGFb1), a pro-fibrogenic cytokine. No studies have defined a role for ALK1 in heart failure. We tested the hypothesis that reduced ALK1 expression promotes maladaptive cardiac remodeling in heart failure. Methods and Results: ALK1 mRNA expression was quantified by RT-PCR in left ventricular (LV) tissue from patients with end-stage heart failure and compared to control LV tissue obtained from the National Disease Research Interchange (n=8/group). Compared to controls, LV ALK1 mRNA levels were reduced by 85% in patients with heart failure. Next, using an siRNA approach, we tested whether reduced ALK1 levels promote TGFb1-mediated collagen production in human cardiac fibroblasts. Treatment with an ALK1 siRNA reduced ALK1 mRNA levels by 75%. Compared to control, TGFb1-mediated Type I collagen and pSmad-3 protein levels were 2.5-fold and 1.7-fold higher, respectively, after ALK1 depletion. To explore a role for ALK1 in heart failure, ALK1 haploinsufficient (ALK1) and wild-type mice (WT; n=8/group) were studied 2 weeks after thoracic aortic constriction (TAC). Compared to WT, baseline LV ALK1 mRNA levels were 50% lower in ALK1 mice. Both LV and lung weights were higher in ALK1 mice after TAC. Cardiomyocyte area and LV mRNA levels of BNP, RCAN, and b-MHC were increased similarly, while SERCa levels were reduced in both ALK1 and WT mice after TAC. Compared to WT, LV fibrosis (Figure) and Type 1 Collagen mRNA and protein levels were higher among ALK1 mice. Compared to WT, LV fractional shortening (48±12 vs 26±10%, p=0.01) and survival (Figure) were lower in ALK1 mice after TAC. Conclusions: Reduced LV expression of ALK1 is associated with advanced heart failure in humans and promotes early mortality, impaired LV function, and cardiac fibrosis in a murine model of heart failure. Further studies examining the role of ALK1 and ALK1 inhibitors on cardiac remodeling are required.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242626
Author(s):  
Tomoyo Matsumura ◽  
Tomokazu Fujimoto ◽  
Akiko Futakuchi ◽  
Yuji Takihara ◽  
Fumika Watanabe-Kitamura ◽  
...  

Purpose This study aimed to investigate the effects of substratum stiffness on the sensitivity of human conjunctival fibroblasts to transforming growth factor (TGF)-β, and to explore the molecular mechanism of action. Methods Human conjunctival fibroblasts were cultured on collagen-coated plastic or silicone plates. The stiffness of the silicone plates was 0.2 or 64 kPa. Cells were treated by 2.5 ng/mL TGF-β2 with or without fibroblast growth factor (FGF)-2 (0–100 ng/mL) for 24 h or 48 h. The protein expression levels were determined by Western blot analysis. Cell proliferation was assessed using the WST-8 assay. Results FGF-2 suppressed the TGF-β-induced expression of α-smooth muscle actin (SMA) and collagen type I (Col I), but not fibronectin (FN). Both FGF-2 and TGF-β2 increased cell proliferation without an additive effect. The induction of α-SMA by TGF-β2 was decreased on the soft substratum, without any change in the expression level or subcellular location of Yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ). FGF-2 suppressed TGF-β-induced α-SMA expression even on the soft substratum. Conclusions FGF-2 treatment and a soft substratum suppressed TGF-β-induced transdifferentiation of conjunctival fibroblasts into myofibroblasts. FGF-2 attenuated the TGF-β-induced expression of α-SMA, even on a soft substratum.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 687 ◽  
Author(s):  
Sam G. Edalat ◽  
Yongjun Jang ◽  
Jongseong Kim ◽  
Yongdoo Park

In vitro maturation of cardiomyocytes in 3D is essential for the development of viable cardiac models for therapeutic and developmental studies. The method by which cardiomyocytes undergoes maturation has significant implications for understanding cardiomyocytes biology. The regulation of the extracellular matrix (ECM) by changing the composition and stiffness is quintessential for engineering a suitable environment for cardiomyocytes maturation. In this paper, we demonstrate that collagen type I, a component of the ECM, plays a crucial role in the maturation of cardiomyocytes. To this end, embryonic stem-cell derived cardiomyocytes were incorporated into Matrigel-based hydrogels with varying collagen type I concentrations of 0 mg, 3 mg, and 6 mg. Each hydrogel was analyzed by measuring the degree of stiffness, the expression levels of MLC2v, TBX18, and pre-miR-21, and the size of the hydrogels. It was shown that among the hydrogel variants, the Matrigel-based hydrogel with 3 mg of collagen type I facilitates cardiomyocyte maturation by increasing MLC2v expression. The treatment of transforming growth factor β1 (TGF-β1) or fibroblast growth factor 4 (FGF-4) on the hydrogels further enhanced the MLC2v expression and thereby cardiomyocyte maturation.


2005 ◽  
Vol 93 (06) ◽  
pp. 1176-1184 ◽  
Author(s):  
Ulrike Möller ◽  
Stephan Herzig ◽  
Trine Fink ◽  
Vladimir Zachar ◽  
Peter Ebbesen ◽  
...  

SummaryInsulin-like growth factor 1 (IGF-1) and plasminogen activator inhibitor-1 (PAI-1) appear to play a crucial role in a number of processes associated with growth and tissue remodelling. IGF-1 was shown to enhance PAI-1 expression in primary hepatocytes and HepG2 hepatoma cells, but the molecular mechanisms underlying this effect have not been fully elucidated. In this study, we investigated the transcriptional mechanism and the signaling pathway by which IGF-1 mediates induction of PAI-1 expression in HepG2 cells. By using human PAI-1 promoter reporter gene assays we found that mutation of the hypoxia responsive element (HRE), which could bind hypoxia-inducible factor-1 (HIF-1), nearly abolished the induction by IGF-1. We found that IGF-1-induced up-regulation of PAI-1 expression was associated with activation of HIF-1α. Furthermore, IGF-1 enhanced HIF-1α protein levels and HIF-1 DNA-binding to each HRE, E4 and E5 as shown by EMSA. Mutation of the E-boxes, E4 and E5, did not affect the IGF-1-dependent induction of PAI-1 promoter constructs under normoxia but abolished the effect of IGF-1 under hypoxia. Inhibition of either the PI3K by LY294002 or ERK1/2 by U0126 reduced HIF-1α protein levels while both inhibitors together completely abolished the IGF-1 effect on HIF-1α. Remarkably, transfection of HepG2 cells with vectors expressing a dominant-negative PDK1 or the PKB inhibitor, TRB3, did not influence while dominant-negative Raf inhibited the IGF-1 effect on HIF-1α. Thus, IGF-1 activates human PAI-1 gene expression through activation of the PI3-kinase and ERK1/2 via HIF-1α.


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