scholarly journals High Glucose Activated Cardiac Fibroblasts by a Disruption of Mitochondria-Associated Membranes

2021 ◽  
Vol 12 ◽  
Author(s):  
Ling-Yu Zhang ◽  
Rui-Ting Lin ◽  
Hao-Ran Chen ◽  
Yong-Cong Yang ◽  
Meng-Fei Lin ◽  
...  

Cardiac fibrosis is evident even in the situation without a significant cardiomyocyte loss in diabetic cardiomyopathy and a high glucose (HG) level independently activates the cardiac fibroblasts (CFs) and promotes cell proliferation. Mitochondrial respiration and glycolysis, which are key for cell proliferation and the mitochondria-associated membranes (MAMs), are critically involved in this process. However, the roles and the underlying mechanism of MAMs in the proliferation of HG-induced CFs are largely unknown. The proliferation and apoptosis of CFs responding to HG treatment were evaluated. The MAMs were quantified, and the mitochondrial respiration and cellular glycolytic levels were determined using the Seahorse XF analyzer. The changes of signal transducer and activator of transcription 3 (STAT3) and mitofusin-2 (MFN2) in responding to HG were also determined, the effects of which on cell proliferation, MAMs, and mitochondrial respiration were assessed. The effects of STAT3 on MFN2 transcription was determined by the dual-luciferase reporter assay (DLRA) and chromatin immunoprecipitation (CHIP). HG-induced CFs proliferation increased the glycolytic levels and adenosine triphosphate (ATP) production, while mitochondrial respiration was inhibited. The MAMs and MFN2 expressions were significantly reduced on the HG treatment, and the restoration of MFN2 expression counteracted the effects of HG on cell proliferation, mitochondrial respiration of the MAMs, glycolytic levels, and ATP production. The mitochondrial STAT3 contents were not changed by HG, but the levels of phosphorylated STAT3 and nuclear STAT3 were increased. The inhibition of STAT3 reversed the reduction of MFN2 levels induced by HG. The DLRA and CHIP directly demonstrated the negative regulation of MFN2 by STAT3 at the transcription levels via interacting with the sequences in the MFN2 promoter region locating at about −400 bp counting from the start site of transcription. The present study demonstrated that the HG independently induced CFs proliferation via promoting STAT3 translocation to the nucleus, which switched the mitochondrial respiration to glycolysis to produce ATP by inhibiting MAMs in an MFN2-depression manner.

2018 ◽  
Vol 51 (5) ◽  
pp. 2250-2261 ◽  
Author(s):  
Yi-Ting  Tsai ◽  
Shih-Hurng Loh ◽  
Chung-Yi Lee ◽  
Shiao-Ping Lee ◽  
Yen-Lin Chen ◽  
...  

Background/Aims: Diabetes is associated with increased incidence of myocardial dysfunction, which is partly characterized by interstitial and perivascular fibrosis. Cardiac fibroblasts have been identified as an important participant in the development of cardiac fibrosis. Exposure of cultured cardiac fibroblasts to high glucose resulted in increased collagen synthesis. Tanshinone IIA can alleviate the ventricular fibrosis that develops in a number of different experimental conditions. However, whether tanshinone IIA can prevent high glucose-induced collagen synthesis in cardiac fibroblasts remains unknown. The aim of this study was to evaluate the effects of tanshinone IIA on high glucose-induced collagen synthesis in cardiac fibroblasts. Methods: Rat cardiac fibroblasts were cultured in high glucose (25 mM) media in the absence or presence of tanshinone IIA and the changes in collagen synthesis, transforming growth factor-β1 (TGF-β1) production and related signaling molecules were assessed by 3H-proline incorporation, quantitative polymerase chain reaction, enzyme linked immunosorbent assay, and Western blotting. Results: The results indicate cardiac fibroblasts exposed to high glucose condition show increased cell proliferation and collagen synthesis and these effects were abolished by tanshinone IIA treatment. Furthermore, the inhibitory effect of tanshinone IIA on high glucose induced cell proliferation and collagen synthesis may be associated with its activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the inhibition of TGF-β1 production and Smad2/3 phosphorylation. Conclusion: In summary, our results highlights the critical role tanshinone IIA plays as an antioxidant in attenuating high glucose-mediated collagen synthesis through inhibiting TGF-β1/Smad signaling in cardiac fibroblasts which provide a mechanistic basis for the clinical application of tanshinone IIA in the treating diabetic-related cardiac fibrosis.


2016 ◽  
Vol 36 (6) ◽  
Author(s):  
Jiaxin Li ◽  
Yingnan Dai ◽  
Zhendong Su ◽  
Guoqian Wei

To investigate the effects of miR-9 on high glucose (HG)-induced cardiac fibrosis in human cardiac fibroblasts (HCFs), and to establish the mechanism underlying these effects. HCFs were transfected with miR-9 inhibitor or mimic, and then treated with normal or HG. Cell viability and proliferation were detected by using the Cell Counting Kit-8 (CCK-8) assay and Brdu-ELISA assay. Cell differentiation and collagen accumulation of HCFs were detected by qRT-PCR and Western blot assays respectively. The mRNA and protein expressions of transforming growth factor-β receptor type II (TGFBR2) were determined by qRT-PCR and Western blotting. Up-regulation of miR-9 dramatically improved HG-induced increases in cell proliferation, differentiation and collagen accumulation of HCFs. Moreover, bioinformatics analysis predicted that the TGFBR2 was a potential target gene of miR-9. Luciferase reporter assay demonstrated that miR-9 could directly target TGFBR2. Inhibition of TGFBR2 had the similar effect as miR-9 overexpression. Down-regulation of TGFBR2 in HCFs transfected with miR-9 inhibitor partially reversed the protective effect of miR-9 overexpression on HG-induced cardiac fibrosis in HCFs. Up-regulation of miR-9 ameliorates HG-induced proliferation, differentiation and collagen accumulation of HCFs by down-regulation of TGFBR2. These results provide further evidence for protective effect of miR-9 overexpression on HG-induced cardiac fibrosis.


2021 ◽  
Vol 20 ◽  
pp. 153303382199783
Author(s):  
XiangWen Yuan ◽  
Zhaoyan Sun ◽  
Congxian Cui

Objective: Retinoblastoma (RB) is a frequent eye cancer in children. Long non-coding RNA (LncRNA) HOXA transcript at the distal tip (HOTTIP) is aberrantly expressed in cancer tissues. This study explores the underlying mechanism of lncRNA HOTTIP in RB. Methods: HOTTIP expression in normal retinal cells and RB cell lines was detected using qRT-PCR. The proliferation of RB cells was measured using CCK-8 and EdU assays, and apoptosis was detected using flow cytometry and Western blotting after the transfection of si-HOTTIP into Y79 cells and pc-HOTTIP into HXO-RB-44 cells. The target relationships between HOTTIP and miR-101-3p, and miR-101-3p and STC1 were predicted by bioinformatics website and verified using dual-luciferase reporter gene assay. The binding of HOTTIP and miR-101-3p was verified using RNA pull-down assay. STC1 mRNA and protein in RB cells were measured using qRT-PCR and Western blotting. Moreover, si-HOTTIP and in-miR-101-3p/in-NC, and si-HOTTIP and pc-STC1/pcDNA were co-transfected into Y79 cells respectively to evaluate cell proliferation and apoptosis. Xenograft study was conducted, and Ki67-positive expression was detected using immunohistochemical staining. Results: HOTTIP expression was promoted in RB tissues and cells. Downregulation of HOTTIP inhibited proliferation and promoted apoptosis of Y79 cells, while upregulation of HOTTIP promoted proliferation and inhibited apoptosis of HXO-RB-44 cells. There were target relationships between HOTTIP and miR-101-3p, and miR-101-3p and STC1. Inhibition of miR-101-3p or overexpression of STC1 reversed the effect of si-HOTTIP on the proliferation and apoptosis of RB cells. Xenograft study showed that knockdown of HOTTIP suppressed the growth of RB in vitro. Conclusion: It could be concluded that HOTTIP sponged miR-101-3p to upregulate STC1 expression, thereby promoting RB cell proliferation and inhibiting apoptosis.


Author(s):  
Xiao-xu Yang ◽  
Zhen-yu Zhao

Cardiac fibrosis is one of the major pathological characteristics of diabetic cardiomyopathy (DCM). MicroRNAs (miRNAs, miRs) have been identified as key regulators in the progression of cardiac fibrosis. This study aimed to investigate the role of miR-30a-5p in DCM and the underlying mechanism. The rat model of diabetes mellitus (DM) was established by streptozotocin injection, and the rat primary cardiac fibroblasts (CFs) were isolated from cardiac tissue and then treated with high glucose (HG). MTT assay was performed to assess the viability of CFs. Dual-luciferase reporter gene assay was conducted to verify the interaction between miR-30a-5p and Smad2. The expression of miR-30a-5p was downregulated in the myocardial tissues of DM rats and HG-stimulated CFs. Overexpression of miR-30a-5p reduced Smad2 levels and inhibited collagen formation in HG-stimulated CFs and DM rats, as well as decreased the proliferation of CFs induced by HG. Smad2 was a target of miR-30a-5p and its expression was inhibited by miR-30a-5p. Furthermore, the simultaneous overexpression of Smad2 and miR-30a-5p reversed the effect of miR-30a-5p overexpression alone in CFs. Our results indicated that miR-30a-5p reduced Smad2 expression and also induced a decrease in proliferation and collagen formation in DCM.


2021 ◽  
pp. 1-11
Author(s):  
Min Wei ◽  
Youguo Chen ◽  
Wensheng Du

BACKGROUND: Cervical cancer (CC) is the most common form of gynecological malignancy. Long intergenic non-protein coding RNA 858 (LINC00858) has been identified to participate in multiple cancers. However, the role and mechanism of LINC00858 in CC cells are still elusive. AIM: The aim of this study is to explore the biological functions and mechanisms of LINC00858 in CC cells. METHODS: RT-qPCR analysis was used to examine the expression of LINC00858 in CC cells. EdU and colony formation assay were utilized to assess cell proliferation. TUNEL assay and flow cytometry assay were conducted to assess cell apoptosis. The mechanism regarding LINC00858 was certified through RNA pull down, RIP and luciferase reporter assays. RESULTS: The up-regulated LINC00858 was detected in CC cells. Reduction of LINC00858 effectively subdued CC cells proliferation and stimulated cell apoptosis. LINC00858 was determined to bind with miR-3064-5p and up-regulate VMA21 in CC cells. In rescue assays, miR-3064-5p down-regulation and VMA21 up-regulation were able to counteract the effect caused by LINC00858 decrease on CC cell proliferation and apoptosis. CONCLUSION: LINC00858 enhances cell proliferation, while restraining cell apoptosis in CC through targeting miR-3064-5p/VMA21 axis, implying that LINC00858 may serve as a promising therapeutic target for CC.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jipeng Lu ◽  
Zhongxiong Wu ◽  
Ying Xiong

Abstract Background Osteoarthritis (OA) is a joint disease characterized via destruction of cartilage. Chondrocyte damage is associated with cartilage destruction during OA. Long noncoding RNAs (lncRNAs) are implicated in the regulation of chondrocyte damage in OA progression. This study aims to investigate the role and underlying mechanism of lncRNA homeobox antisense intergenic RNA (HOTAIR) in OA chondrocyte injury. Methods Twenty-three OA patients and healthy controls without OA were recruited. Chondrocytes were isolated from OA cartilage tissues. HOTAIR, microRNA-107 (miR-107) and C-X-C motif chemokine ligand 12 (CXCL12) levels were measured by quantitative real-time polymerase chain reaction and western blot. Cell proliferation, apoptosis and extracellular matrix (ECM) degradation were measured using cell counting kit-8, flow cytometry and western blot. The target interaction was explored by bioinformatics, luciferase reporter and RNA immunoprecipitation assays. Results HOTAIR expression was enhanced, and miR-107 level was reduced in OA cartilage samples. HOTAIR overexpression inhibited cell proliferation, but induced cell apoptosis and ECM degradation in chondrocytes. HOTAIR knockdown caused an opposite effect. MiR-107 was sponged and inhibited via HOTAIR, and knockdown of miR-107 mitigated the effect of HOTAIR silence on chondrocyte injury. CXCL12 was targeted by miR-107. CXCL12 overexpression attenuated the roles of miR-107 overexpression or HOTAIR knockdown in the proliferation, apoptosis and ECM degradation. CXCL12 expression was decreased by HOTAIR silence, and restored by knockdown of miR-107. Conclusion HOTAIR knockdown promoted chondrocyte proliferation, but inhibited cell apoptosis and ECM degradation in OA chondrocytes by regulating the miR-107/CXCL12 axis.


2021 ◽  
Vol 11 (9) ◽  
pp. 1744-1751
Author(s):  
Deqian Meng ◽  
Wenyou Pan ◽  
Ju Li

Accumulating evidence have indicated that MicroRNAs (miRNAs) are key regulators in human rheumatoid arthritis (RA). The aim of this study was to explore the functional roles of miR-16-5p in proliferation, inflammation, and apoptosis of fibroblast-like synoviocytes (FLS). The expression of miR-16-5p and SOCS6 in FLA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and apoptosis were measured by CCK-8 assay and flow cytometry, respectively. Luciferase reporter assay was used to verify the direct target of miR-16-5p. Western blot analysis was performed to analysis the levels of SOCS6, Bcl-2, Bax and cleaved caspase 3. miR-16-5p expression was significantly upregulated while SOCS6 level was decreased in RA-FLS compared with normal FLS. In addition, luciferase reporter assay confirmed that SOCS6 was the target of miR-16-5p. Silencing of miR-16-5p inhibited cell proliferation, releases of TNF-α, IL-1β, IL-6 and IL-8, and induced the apoptosis. The effects of miR-16-5p silencing on RA-FLS were reversed by downregulation of SOCS6. In summary, knockdown of miR-16-5p could suppress cell proliferation and accelerate the apoptosis of RA-FLS through targeting SOCS6, which may provide a potential therapeutic target for patients with RA.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Sashwati Roy ◽  
Savita Khanna ◽  
Chandan K Sen

Background . Transforming growth factor beta-1 (TGFbeta-1) is a key cytokine implicated in the development of cardiac fibrosis following ischemia-reperfusion (IR) injury. The profibrotic effects of TGFbeta-1 are primarily attributable to the differentiation of cardiac fibroblasts (CF) to myofibroblasts. Previously, we have reported perceived hyperoxia (Circ Res 92:264 –71), sub-lethal reoxygenation shock during IR, induces differentiation of CF to myofibroblasts at the infarct site. The mechanisms underlying oxygen-sensitive induction of TGFbeta-1 mRNA remain to be characterized. Hypothesis . Fra2 mediates oxygen-induced TGFbeta-1 mRNA expression in adult cardiac fibroblasts. Methods. TGFbeta-1 mRNA expression in infarct tissue was investigated in an IR injury model. The left anterior descending coronary artery of mice was transiently occluded for 60 minutes followed by reperfusion to induce IR injury. Spatially resolved infarct and non-infarct tissues were collected at 0, 1, 3, 5, and 7 days post-IR using laser capture microdissection. TGFbeta-1 mRNA levels were measured using real-time PCR. To investigate the role of oxygen in the regulation of TGFbeta-1, we used our previously reported model of perceived hyperoxia where CF (from 5wks old mice) after isolation were cultured at 5%O 2 (physiological pO 2 ) followed by transferring them to 20%O 2 to induce hyperoxic insult. Results & Conclusions. In vivo, a significant increase (p<0.01; n=5) in TGFbeta-1 mRNA was observed at the infarct site already at day 1 post-IR. The levels continued to increase until day 7 post-IR. In vitro, exposure of CF to 20%O 2 hyperoxic insult induced TGFbeta-1 mRNA (p<0.001; n=4) and protein (p<0.01; n=4) expression. Using a TGFbeta-1 promoter-luciferase reporter and DNA binding assays, we collected first evidence that AP-1 and its component Fra2 as major mediators of oxygen-induced TGFbeta-1 expression. Exposure to 20%O 2 resulted in increased localization of Fra2 in nucleus. siRNA-dependent Fra-2 knock-down completely abrogated oxygen-induced TGFbeta1 expression. In conclusion, this study presents first evidence that Fra-2 is involved in inducible TGFbeta1 expression in CF. Fra2 was noted as being central in regulating oxygen-induced TGFbeta-1 expression.s


2021 ◽  
Vol 12 ◽  
Author(s):  
Qin Zhang ◽  
Jing Long ◽  
Nannan Li ◽  
Xuelian Ma ◽  
Lisheng Zheng

Hyperglycemia exposure results in the dysfunction of endothelial cells (ECs) and the development of diabetic complications. Circular RNAs (circRNAs) have been demonstrated to play critical roles in EC dysfunction. The current study aimed to explore the role and mechanism of circRNA CLIP–associating protein 2 (circ_CLASP2, hsa_circ_0064772) on HG-induced dysfunction in human umbilical vein endothelial cells (HUVECs). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the levels of circ_CLASP2, miR-140-5p and F-box, and WD repeat domain-containing 7 (FBXW7). The stability of circ_CLASP2 was identified by the actinomycin D and ribonuclease (RNase) R assays. Cell colony formation, proliferation, and apoptosis were measured by a standard colony formation assay, colorimetric 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay, and flow cytometry, respectively. Western blot analysis was performed to determine the expression of related proteins. Targeted correlations among circ_CLASP2, miR-140-5p, and FBXW7 were confirmed by dual-luciferase reporter assay. High glucose (HG) exposure downregulated the expression of circ_CLASP2 in HUVECs. Circ_CLASP2 overexpression or miR-140-5p knockdown promoted proliferation and inhibited apoptosis of HUVECs under HG conditions. Circ_CLASP2 directly interacted with miR-140-5p via pairing to miR-140-5p. The regulation of circ_CLASP2 overexpression on HG-induced HUVEC dysfunction was mediated by miR-140-5p. Moreover, FBXW7 was a direct target of miR-140-5p, and miR-140-5p regulated HG-induced HUVEC dysfunction via FBXW7. Furthermore, circ_CLASP2 mediated FBXW7 expression through sponging miR-140-5p. Our current study suggested that the overexpression of circ_CLASP2 protected HUVEC from HG-induced dysfunction at least partly through the regulation of the miR-140-5p/FBXW7 axis, highlighting a novel therapeutic approach for the treatment of diabetic-associated vascular injury.


2021 ◽  
Author(s):  
Yaping Liu ◽  
Xu Zhao ◽  
Yinnan Chen ◽  
Gang Guo ◽  
Jiansheng Wang ◽  
...  

Abstract To evaluate the expression of PITPNA-AS1 and miR-98-5p in gastric cancer tissues as well as their association with progression of gastric cancer, and investigate the role of PITPNA-AS1 and miR-98-5p in developing platinum resistance. RNA sequencing was used to identify candidate lncRNAs and microRNAs related to local recurrence of gastric cancer. qRT-PCR was used to investigate the expression of PITPNA-AS1 and miR-98-5p. CCK-8 and caspase3/7 activity were used to evaluate the cell proliferation and apoptosis rate. Dual luciferase reporter gene assay and RNA pull down were used to evaluate the cross talk between PITPNA-AS1 and miR-98-5p. PITPNA-AS1 and miR-98-5p could regulate cell proliferation and inhibit apoptosis in gastric cancer cell lines. Cisplatin and lobaplatin could significantly suppress the expression of PITPNA-AS1, which interacted with negatively regulated miR-98-5p expression. PITPNA-AS1 overexpression impaired the effect of platinum, which was partially reversed by downregulation of miR-98-5p knock down. In gastric cancer, PITPNA-AS1 and miR-98-5p could regulat cell growth, apoptosis and platinum resistance. They have the potential to be biomarkers and curative therapeutic targets. However, further research on molecular mechanisms are needed.


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