scholarly journals Knockdown of LSD1 alleviates the IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation via TRIM32-mediated autophagy

Author(s):  
Wenqiang Xu ◽  
Xiaofeng Liu ◽  
Wenqing Qu ◽  
Xin Wang ◽  
Hao Su ◽  
...  

Abstract Osteoarthritis (OA) is a common joint disease with characteristics of chronic inflammation and articular cartilage degeneration. It has been proved that LSD1 was up-regulated in OA cartilage tissues, but its role and regulatory mechanism in OA are unclear. Herein, interleukin 1 beta (IL-1β)-treated human chondrocytes was performed as a cell model of OA. Then, LSD1 expression was found that up-regulated in OA cartilage tissues and IL-1β-induced chondrocytes. Knockdown of LSD1 increased cell viability, while decreased apoptosis rate and inflammatory cytokines secretion levels in IL-1β-induced chondrocytes. In addition, knockdown of LSD1 reduced the expression of catabolic proteins (MMP-13 and ADAMTS-5) and enhanced the expression of anabolic proteins (Collagen II and Aggrecan) in chondrocytes after IL-1β stimulation. Moreover, overexpression of TRIM32 repressed chondrocyte viability, while promoted IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation. The expression of LSD1 and TRIM32 in OA cartilage was positively correlated, and knockdown of LSD1 down-regulated TRIM32 expression of chondrocytes. Our data further indicated that LSD1 regulated autophagy of chondrocytes through modulating TRIM32. Overexpression of TRIM32 reduced the effect of LSD1 knockdown on IL-1β-induced chondrocytes, while activating autophagy by Rapamycin further reversed this reduction. Therefore, our study shows that knockdown of LSD1 inhibited IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation via TRIM32-mediated autophagy.

Author(s):  
Mingli Feng ◽  
Lin Jing ◽  
Jingbo Cheng ◽  
Shuai An ◽  
Jiang Huang ◽  
...  

AbstractOsteoarthritis (OA) is a chronic disease characterized by articular cartilage degeneration and uncontrolled chondrocyte apoptosis. At present, accumulating evidence introduces that circular RNA (circRNA) is involved in the development of OA. The aim of our study was to explore the role and the functional mechanism of circ_0020093 in OA cell model. Human chondrocytes were treated with interleukin-1 beta (IL-1β) to construct OA model. The expression of circ_0020093, miR-23b, and Sprouty 1 (SPRY1) mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell apoptosis was assessed by flow cytometry assay. The expression of extracellular matrix (ECM)-associated markers and SPRY1 protein level was detected by qRT-PCR and Western blot. Bioinformatics analysis-predicted relationship between miR-23b and circ_0020093 or SPRY1 was further verified by dual-luciferase reporter assay and RNA pull-down assay. In this study, we found that the expression of circ_0020093 and SPRY1 was declined, while miR-23b expression was elevated in IL-1β-treated chondrocytes. IL-1β induced chondrocyte apoptosis and ECM degradation, while these negative effects were alleviated by circ_0020093 overexpression or miR-23b inhibition. MiR-23b was a target of circ_0020093, and SPRY1 was a downstream target of miR-23b. Rescue experiments showed that miR-23b enrichment reversed the role of circ_0020093 overexpression, and SPRY1 knockdown also reversed the effects of miR-23b inhibition. Importantly, circ_0020093 positively regulated SPRY1 expression by targeting miR-23b. In conclusion, circ_0020093 ameliorates IL-1β-induced apoptosis and ECM degradation of human chondrocytes by regulating the miR-23b/SPRY1 axis.


2021 ◽  
Author(s):  
Ding-Chao Zhu ◽  
Yi-Han Wang ◽  
Jia-Hao Lin ◽  
Zhi-Min Miao ◽  
Jia-Jing Xu ◽  
...  

Osteoarthritis (OA) is a common degenerative joint disease characterized by articular cartilage degeneration and inflammation. Currently, there is hardly any effective treatment for OA due to its complicated pathology and...


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Guiqiang Miao ◽  
Xuehui Zang ◽  
Huige Hou ◽  
Hui Sun ◽  
Lihui Wang ◽  
...  

Osteoarthritis (OA) is a chronic degenerative joint disease, where chondrocyte apoptosis is responsible for cartilage degeneration. Bax is a well-known proapoptotic protein of the Bcl-2 family, involved in a large number of physiological and pathological processes. However, the regulation mechanisms of Bax underlying chondrocyte apoptosis in OA remain unknown. In the present study, we determined the role of Bax in human OA and chondrocyte apoptosis. The results showed that Bax was upregulated in chondrocytes from the articular cartilage of OA patients and in cultured chondrocyte-like ATDC5 cells treated by IL-1β. Bax was identified to be the direct target of miR-29a by luciferase reporter assay and by western blotting. Inhibition of miR-29a by the mimics protested and overexpression by miR-29a inhibitors aggravated ATDC5 apoptosis induced by IL-1β. These data reveal that miR-29a/Bax axis plays an important role in regulating chondrocyte apoptosis and suggest that targeting the proapoptotic protein Bax and increasing expression levels of miR-29a emerge as potential approach for protection against the development of OA.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaochen Li ◽  
Li Zhang ◽  
Xiaoqing Shi ◽  
Taiyang Liao ◽  
Nongshan Zhang ◽  
...  

Osteoarthritis (OA) is a worldwide degenerative joint disease that seriously impaired the quality of life of patients. OA has been established as a disease with metabolic disorder. Cholesterol 25-hydroxylase (CH25H) was proved to play a key role in cartilage cholesterol metabolism. However, the biological function and mechanism of CH25H in OA remains further investigation. Growing researches have proved the vital roles of miRNAs in OA progression. In this study, we screened out miR-10a-3p through high-throughput miRNA sequencing which may bind to CH25H. Molecular mechanism investigation indicated that miR-10a-3p is an upstream target of CH25H. Functional exploration revealed miR-10a-3p suppressed the inflammatory responses, cholesterol metabolism and extracellular matrix (ECM) degradation in primary chondrocytes. Moreover, rescue assays implied that miR-10a-3p reversed CH25H plasmids induced inflammatory cytokine production and ECM degradation. Furthermore, the OA rat model was established to explore the function of miR-10a-3p in vivo. The results showed that miR-10a-3p can recover the OA features through targeting CH25H/CYP7B1/RORα axis. In conclusion, these findings implied a crucial role of miR-10a-3p/CH25H/CYP7B1/RORα axis in OA, which may provide a promising therapeutic strategy for OA.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yoshiaki Ito ◽  
Tokio Matsuzaki ◽  
Fumiaki Ayabe ◽  
Sho Mokuda ◽  
Ryota Kurimoto ◽  
...  

AbstractOsteoarthritis (OA), the most common aging-related joint disease, is caused by an imbalance between extracellular matrix synthesis and degradation. Here, we discover that both strands of microRNA-455 (miR-455), -5p and -3p, are up-regulated by Sox9, an essential transcription factor for cartilage differentiation and function. Both miR-455-5p and -3p are highly expressed in human chondrocytes from normal articular cartilage and in mouse primary chondrocytes. We generate miR-455 knockout mice, and find that cartilage degeneration mimicking OA and elevated expression of cartilage degeneration-related genes are observed at 6-months-old. Using a cell-based miRNA target screening system, we identify hypoxia-inducible factor-2α (HIF-2α), a catabolic factor for cartilage homeostasis, as a direct target of both miR-455-5p and -3p. In addition, overexpression of both miR-455-5p and -3p protect cartilage degeneration in a mouse OA model, demonstrating their potential therapeutic value. Furthermore, knockdown of HIF-2α in 6-month-old miR-455 knockout cartilage rescues the elevated expression of cartilage degeneration-related genes. These data demonstrate that both strands of a miRNA target the same gene to regulate articular cartilage homeostasis.


2019 ◽  
Author(s):  
Olga Katsara ◽  
Mukundan Attur ◽  
Victoria Kolupaeva

ABSTRACTAs world population growing older, burden of age-related conditions soars. One of them is osteoarthritis (OA), a debilitating joint disease with no effective treatment. Articular cartilage degeneration is a central event in OA, and changes in expression of many genes in OA cartilage are well-documented. Still, the specific mechanisms are rarely known. We showed that in OA cartilage the increased abundance of many proteins, including extracellular matrix protein Fibronectin (Fn1) and an orphan nuclear receptor Nr4a1 is translationally controlled and requires inactivation of 4EBP, an inhibitor of cap-dependent translation. Importantly, intra-articular injection of the translation inhibitor 4E1RCat reduces Fn1 and Nr4a upregulation in a rodent OA model and delays cartilage degeneration. Our results support the hypothesis that maintaining proper translational control is an important homeostatic mechanism, the loss of which contributes to OA development.


2019 ◽  
Vol 87 (4) ◽  
pp. 34 ◽  
Author(s):  
Al-Saadi ◽  
Pang ◽  
Ima-Nirwana ◽  
Chin

Osteoarthritis (OA) is a joint disease resulting from cartilage degeneration and causing joint pain and stiffness. Glucosamine exerts chondroprotective effects and effectively reduces OA pain and stiffness. This review aims to summarise the mechanism of glucosamine in protecting joint health and preventing OA by conducting a literature search on original articles. Current evidence has revealed that glucosamine exhibits anti-inflammatory effects by reducing the levels of pro-inflammatory factors (such as tumour necrosis factor-alpha, interleukin-1, and interleukin-6) and enhancing the synthesis of proteoglycans that retard cartilage degradation and improve joint function. Additionally, glucosamine improves cellular redox status, reduces OA-mediated oxidative damages, scavenges free radicals, upregulates antioxidant proteins and enzyme levels, inhibits the production of reactive oxygen species, and induces autophagy to delay OA pathogenesis. In conclusion, glucosamine prevents OA and maintains joint health by reducing inflammation, improving the redox status, and inducing autophagy in joints. Further studies are warranted to determine the synergistic effect of glucosamine with other anti-inflammatory and/or antioxidative agents on joint health in humans.


1996 ◽  
Vol 135 (5) ◽  
pp. 1341-1354 ◽  
Author(s):  
M Deshmukh ◽  
J Vasilakos ◽  
T L Deckwerth ◽  
P A Lampe ◽  
B D Shivers ◽  
...  

Sympathetic neurons undergo programmed cell death (PCD) when deprived of NGF. We used an inhibitor to examine the function of interleukin-1 beta-converting enzyme (ICE) family proteases during sympathetic neuronal death and to assess the metabolic and genetic status of neurons saved by such inhibition. Bocaspartyl(OMe)-fluoromethylketone (BAF), a cell-permeable inhibitor of the ICE family of cysteine proteases, inhibited ICE and CPP32 (IC50 approximately 4 microM) in vitro and blocked Fas-mediated apoptosis in thymocytes (EC50 approximately 10 microM). At similar concentrations, BAF also blocked the NGF deprivation-induced death of rat sympathetic neurons in culture. Compared to NGF-maintained neurons, BAF-saved neurons had markedly smaller somas and maintained only basal levels of protein synthesis; readdition of NGF restored growth and metabolism. Although BAF blocked apoptosis in sympathetic neurons, it did not prevent the fall in protein synthesis or the increase in the expression of c-jun, c-fos, and other mRNAs that occur during neuronal PCD, implying that the ICE-family proteases function downstream of these events during PCD.NGF and BAF rescued sympathetic neurons with an identical time course, suggesting that NGF, in addition to inhibiting metabolic and genetic events associated with neuronal PCD, can act posttranslationally to abort apoptosis at a time point indistinguishable from the activation of cysteine proteases. Both poly-(ADP ribose) polymerase and pro-ICE and Ced-3 homolog-1 (ICH-1) appear to be cleaved in a BAF-inhibitable manner, although the majority of pro-CPP32 appears unchanged, suggesting that ICH-1 is activated during neuronal PCD. Potential implications of these findings for anti-apoptotic therapies are discussed.


2020 ◽  
Vol 21 (9) ◽  
pp. 838-848 ◽  
Author(s):  
Lin Xu ◽  
Yefu Li

Preserving of articular cartilage is an effective way to protect synovial joints from becoming osteoarthritic (OA) joints. Understanding of the molecular basis of articular cartilage degeneration will provide valuable information in the effort to develop cartilage preserving drugs. There are currently no disease-modifying OA drugs (DMOADs) available to prevent articular cartilage destruction during the development of OA. Current drug treatments for OA focus on the reduction of joint pain, swelling, and inflammation at advanced stages of the disease. However, based on discoveries from several independent research laboratories and our laboratory in the past 15 to 20 years, we believe that we have a functional molecular understanding of articular cartilage degeneration. In this review article, we present and discuss experimental evidence to demonstrate a sequential chain of the molecular events underlying articular cartilage degeneration, which consists of transforming growth factor beta 1, high-temperature requirement A1 (a serine protease), discoidin domain receptor 2 (a cell surface receptor tyrosine kinase for native fibrillar collagens), and matrix metalloproteinase 13 (an extracellularmatrix degrading enzyme). If, as we strongly suspect, this molecular pathway is responsible for the initiation and acceleration of articular cartilage degeneration, which eventually leads to progressive joint failure, then these molecules may be ideal therapeutic targets for the development of DMOADs.


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