miR-22 regulates starvation-induced autophagy and apoptosis in cardiomyocytes by targeting p38α

Small extracellular vesicles derived from microRNA-22-3p-overexpressing mesenchymal stem cells protect retinal ganglion cells by regulating MAPK pathway

Glaucoma is the leading cause of irreversible blindness and is characterized by progressive retinal ganglion cell (RGC) loss and retinal nerve fiber layer thinning. Currently, no existing treatment is effective for the preservation of RGCs. MicroRNA-22-3p (miR22) and small extracellular vesicles derived from mesenchymal stem cells (MSC-sEVs) have neuroprotective effects. In this study, we apply miR22-overexpressing MSC-sEVs in an N-methyl-D-aspartic acid (NMDA)-induced RGC injury model to assess their short-term therapeutic effects and explore the underlying mechanisms. We find that mice in the miR22-sEVs-treated group have thicker retinas, fewer apoptotic cells, more reserved RGCs, better retinal function, and lower expression levels of Bax and caspase-3. MiR22-sEVs treatment promotes viability, inhibits apoptosis and inhibits Bax and caspase-3 expression in RGC-5 cells. MiR22 targets mitogen-activated protein kinase kinase kinase 12 to inhibit apoptosis by regulating the mitogen-activated protein kinase (MAPK) signaling pathway. Collectively, our results suggest that miR22-sEVs ameliorate NMDA-induced RGC injury through the inhibition of MAPK signaling pathway-mediated apoptosis, providing a potential therapy for glaucoma and other diseases that involve RGC damage.

Research Progress on Cardiac Tissue Construction of Mesenchymal Stem Cells for Myocardial Infarction

Heart failure is still the main complication affecting the prognosis of acute myocardial infarction (AMI), and mesenchymal stem cells (MSCs) are an effective treatment to replace necrotic myocardium and improve cardiac functioning. However, the transplant survival rate of MSCs still presents challenges. In this review, the biological characteristics of MSCs, the progress of mechanism research in the treatment of myocardial infarction, and the advances in improving the transplant survival rate of MSCs in the replacement of necrotic myocardial infarction are systematically described. From a basic to advanced clinical research, MSC transplants have evolved from a pure injection, an exosome injection, the genetic modification of MSCs prior to injection to the cardiac tissue engineering of MSC patch grafting. This study shows that MSCs have wide clinical applications in the treatment of AMI, suggesting improved myocardial tissue creation. A broader clinical application prospect will be explored and developed to improve the survival rate of MSC transplants and myocardial vascularization.

miR-22a targets p62/SQSTM1 to negatively affect autophagy and disease resistance of grass carp (Ctenopharyngodon idella)

MicroRNAs (miRNAs) are integral to many biological functions, including autophagy, a process recently proven to be closely linked to innate immunity. In this study, we present findings on miR-22a, a teleost homolog of mammalian miR-22, illustrating its capacity to target the autophagy adaptor p62, subsequently inducing downregulation at both mRNA and protein levels. Utilizing Western blot analyses, we demonstrated that miR-22a inhibits the autophagy flux of CIK cells, correlated with an elevated presence of LC3 II. Additionally, the overexpression of miR-22a resulted in the suppression of NF-κB signaling, leading to reduced cellar antimicrobial abilities and increased apoptosis. These findings provide novel insights into the role of miR-22a as an autophagy-related miRNA and its immune mechanisms against pathogens via p62 in teleost, enriching our understanding of the interplay between autophagy and innate immunity.

The BCL2/BAX/ROS pathway is involved in the inhibitory effect of astragaloside IV on pyroptosis in human umbilical vein endothelial cells

CONTEXT

Astragaloside IV (AS-IV) is extracted from Astragalus membranaceus (Fisch.) Bunge (Fabaceae). However, its effects on endothelial cell injury remain unclear.

OBJECTIVE

To investigate the mechanisms underlying the effects of AS-IV on lipopolysaccharide (LPS)-induced endothelial injury in vitro.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVECs) were pre-treated with AS-IV (100 µmol/mL), 4-hydroxy-3-methoxyacetophenone (APO, 10 µmol/mL), N-acetylcysteine (NAC, 50 µmol/mL) and Ac-YVAD-cmk (AC, 5 µmol/mL) for 2 h before 1 μg/mL LPS 24 h exposure. Untreated cells cultured without any exposure were used as controls. Cell viability, reactive oxygen species (ROS) and pyroptosis assays were performed. The pyroptosis related proteins were detected by western blot.

RESULTS

The rate in late pyroptosis (Q2-2) of AS-IV (13.65 ± 0.74%), APO (13.69 ± 0.67%) and NAC (15.87 ± 0.46%) groups was lower than the LPS group (21.89 ± 0.66%, p < 0.05), while the rate in early pyroptosis (Q2-4) of AS-IV group (12.00 ± 0.26%) was lower than other groups (p < 0.05). The expression of NOX4, GSDMD, NLRP3, ASC and caspase-1 decreased after AS-IV, NAC or AC intervention (p < 0.05). The ROS production in AS-IV (4664 ± 153.20), APO (4094 ± 78.37), NAC (5103 ± 131.10) and AC (3994 ± 102.50) groups was lower than the LPS (5986 ± 127.30) group, while the mitochondrial BCL2/BAX protein expression ratio increased in AS-IV, APO and NAC groups (p < 0.05).

DISCUSSION AND CONCLUSIONS

AS-IV suppressed pyroptosis in LPS-activated HUVECs by inducing ROS/NLRP3-mediated inhibition of the inflammatory response, providing a scientific basis for clinical applications of AS-IV.

Inhibiting miR-22 Alleviates Cardiac Dysfunction by Regulating Sirt1 in Septic Cardiomyopathy

High morbidity and mortality are the most typical characteristics of septic cardiomyopathy. We aimed to reveal the role of miR-22 in septic cardiomyopathy and to explore the underlying mechanisms. miR-22 cardiac-specific knockout (miR-22^cKO) mice and miR-22 cardiac-specific transgenic (miR-22^cOE) mice were subjected to a cecal ligation and puncture (CLP) operation, while a sham operation was used in the control group. The echocardiogram results suggested that miR-22^cKO CLP mice cardiac dysfunction was alleviated. The serum LDH and CK-MB were reduced in the miR-22^cKO CLP mice. As expected, there was reduced apoptosis, increased autophagy and alleviated mitochondrial dysfunction in the miR-22^cKO CLP mice, while it had contrary role in the miR-22^cOE group. Inhibiting miR-22 promoted autophagy by increasing the LC3II/GAPDH ratio and decreasing the p62 level. Additionally, culturing primary cardiomyocytes with lipopolysaccharide (LPS) simulated sepsis-induced cardiomyopathy in vitro. Inhibiting miR-22 promoted autophagic flux confirmed by an increased LC3II/GAPDH ratio and reduced p62 protein level under bafilomycin A1 conditions. Knocking out miR-22 may exert a cardioprotective effect on sepsis by increasing autophagy and decreasing apoptosis via sirt1. Our results revealed that targeting miR-22 may become a new strategy for septic cardiomyopathy treatment.

Investigate the Effect of miR-22 on the Apoptosis of Coronary Heart Disease Cells Through the Wnt-1 Pathway Based on Nano-Silica-Induced Rat Models

In this paper, by examining the toxicity of nano-silica to coronary heart disease cells, we explored the apoptosis of rat myocardial cells induced by nano-silica, and explored the effect of apoptosis on cells during the process of myocardial cytotoxicity induced by nano-silica. This article selects rat cardiomyocytes as the research object and conducts a group control experiment. A control group is set up with cells that are not stained with nano-silica. Different concentrations of nanosilica suspensions are applied to rat cells and detected by CCK-8 method. Cell survival rate after exposure to different concentrations of cells is used to determine the most stable exposure time and concentration. We used flow cytometry to detect intracellular reactive oxygen species and apoptotic rates, and used Western Blot to detect the expression of proteins that affect apoptosis. Finally, we investigated the effect of the Wnt signaling pathway on coronary heart disease. The Wnt signaling pathway regulates the development of the heart and blood vessels. In the treatment of cardiovascular disease, this pathway will be activated again to play a regulatory role. We conclude that nano-silica can induce cytotoxicity in rat myocardial cells through the Wnt-1 pathway, and nanosilica can induce myocardial cell apoptosis through the Wnt-1 pathway.

TUNEL Assay: A Powerful Tool for Kidney Injury Evaluation

Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay is a long-established assay used to detect cell death-associated DNA fragmentation (3'-OH DNA termini) by endonucleases. Because these enzymes are particularly active in the kidney, TUNEL is widely used to identify and quantify DNA fragmentation and cell death in cultured kidney cells and animal and human kidneys resulting from toxic or hypoxic injury. The early characterization of TUNEL as an apoptotic assay has led to numerous misinterpretations of the mechanisms of kidney cell injury. Nevertheless, TUNEL is becoming increasingly popular for kidney injury assessment because it can be used universally in cultured and tissue cells and for all mechanisms of cell death. Furthermore, it is sensitive, accurate, quantitative, easily linked to particular cells or tissue compartments, and can be combined with immunohistochemistry to allow reliable identification of cell types or likely mechanisms of cell death. Traditionally, TUNEL analysis has been limited to the presence or absence of a TUNEL signal. However, additional information on the mechanism of cell death can be obtained from the analysis of TUNEL patterns.

Autophagy in cardiovascular diseases: role of noncoding RNAs

Cardiovascular diseases (CVDs) remain the world's leading cause of death. Cardiomyocyte autophagy helps maintain normal metabolism and functioning of the heart. Importantly, mounting evidence has revealed that autophagy plays a dual role in CVD pathology. Under physiological conditions, moderate autophagy maintains cell metabolic balance by degrading and recycling damaged organelles and proteins, and it promotes myocardial survival, but excessive or insufficient autophagy is equally deleterious and contributes to disease progression. Noncoding RNAs (ncRNAs) are a class of RNAs transcribed from the genome, but most ncRNAs do not code for functional proteins. In recent years, increasingly, various ncRNAs have been identified, and they play important regulatory roles in the physiological and pathological processes of organisms, as well as in autophagy. Thus, determining whether ncRNA-regulated autophagy plays a protective role in CVDs or promotes their progression can help us to develop ncRNAs as therapeutic targets in autophagy-related CVDs. In this review, we briefly summarize the regulatory roles of several important ncRNAs, including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the autophagy of various CVDs to provide a theoretical basis for the etiology and pathogenesis of CVDs and develop novel therapies to treat CVDs.

MiR-22-3p inhibits fibrotic cataract through inactivation of HDAC6 and increase of α-tubulin acetylation

OBJECTIVES

Fibrotic cataract, including posterior capsule opacification (PCO) and anterior subcapsular cataract (ASC), renders millions of people visually impaired worldwide. However, the underlying mechanism remains poorly understood. Here, we report a miRNA-based regulatory pathway that controls pathological fibrosis of lens epithelium.

MATERIALS AND METHODS

Expression of miR-22-3p and histone deacetylase 6 (HDAC6) in normal and PCO patient samples were measured by qPCR. Human lens epithelial explants were treated with TGF-β2 in the presence or absence of miR-22-3p mimics or inhibitor. Cell proliferation was determined by MTS assay, and migration was tested by transwell assay. Expression of HDAC6 and EMT-related molecules were analysed by Western blot, qPCR and immunocytochemical experiments.

RESULTS

We identify miR-22-3p as a downregulated miRNA targeting HDAC6 in LECs during lens fibrosis and TGF-β2 treatment. Mechanistically, gain- and loss-of-function experiments in human LECs and lens epithelial explants reveal that miR-22-3p prevents proliferation, migration and TGF-β2 induced EMT of LECs via targeting HDAC6 and thereby promoting α-tubulin acetylation. Moreover, pharmacological targeting of HDAC6 deacetylase with Tubacin prevents fibrotic opaque formation through increasing α-tubulin acetylation under TGF-β2 stimulated conditions in both human lens epithelial explants and the whole rat lenses.

CONCLUSIONS

These findings suggest that miR-22-3p prevents lens fibrotic progression by targeting HDAC6 thereby promoting α-tubulin acetylation. The 'miR-22-HDAC6-α-tubulin (de)acetylation' signalling axis may be therapeutic targets for the treatment of fibrotic cataract.

Diagnostic and prognostic value of circulating miRNA-499 and miRNA-22 in acute myocardial infarction

BACKGROUND

Currently, acute myocardial infarction (AMI) represents a serious cardiovascular disease with high morbidity and mortality. Therefore, this study aimed to systematically evaluate the roles of miRNA-499 and miRNA-22 as potential biomarkers for AMI.

METHODS

According to the inclusion and exclusion criteria, we measured circulating levels of miRNAs in 50 AMI patients and 50 non-MI populations. The expression levels of plasma miRNA-499 and miRNA-22 were analyzed by real-time fluorescent quantitative polymerase chain reaction (qRT-PCR). A statistical analysis of clinical data of AMI patients was conducted by 90-day follow-up.

RESULTS

Real-time PCR analysis showed that the relative expression level of miRNA-499 increased gradually among the three groups (P < .05). However, the expression of miRNA-22 showed a downward trend (P < .05). According to logistic analysis, the relative levels of miRNA-499 and miRNA-22 were important predictors of AMI. When the miRNA-499 and miRNA-22 levels were 0.377 and 0.946 separately, the diagnostic value of miRNA-499 and miRNA-22 for AMI was 86.00% and 86.00% for sensitivity, and 98.00% and 94.00% for specificity, respectively. In addition, compared to the baseline GRACE scoring system, the combination of miRNA-499, miRNA-22, and GRACE scores had a stronger discriminating power for MACE occurrence, with a sensitivity of 100.00% and a specificity of 79.40%.

CONCLUSIONS

The results showed that plasma miRNA-499 and miRNA-22 were more sensitive and specific for the diagnosis of AMI, suggesting that they can be used as potential biomarkers for clinical diagnosis of AMI.

The circular RNA circ-ITCH acts as a tumour suppressor in osteosarcoma via regulating miR-22

Background: Osteosarcoma (OS) is the most prevailing primary bone tumour and the third prevalent tumour in children and adolescents. Despite advanced treatments, the survival rate of OS has not been effectively improved. Here, we intended to investigate the functional impacts of circ-ITCH on OS. Methods: Circ-ITCH expression in OS tissues and cells was evaluated utilizing qRT-PCR. Viability and proliferation of MG63 and Saos-2 cells were determined by utilizing CCK-8 assay and BrdU assay. Transwell assay was utilized to investigate migration and invasion. Western blot was utilized to distinguish apoptosis and metastasis-related proteins expression. Sequentially, the above-mentioned parameters were reassessed when up-regulating miR-22. Results: Circ-ITCH was low expressed in OS tissues and cells. Overexpressing circ-ITCH facilitated apoptosis and repressed viability, proliferation, migration and invasion in MG63 and Saos-2 cells. MiR-22 expression was reduced by overexpressing circ-ITCH. The decline of viability, proliferation, migration and invasion made by overexpressing circ-ITCH was alleviated by up-regulating miR-22. Conclusively, circ-ITCH suppressed PTEN/PI3K/AKT and SP-1 pathways via down-regulating miR-22. Conclusion: Circ-ITCH took effects on apoptosis, viability, proliferation, migration and invasion through restraining PTEN/PI3K/AKT and SP-1 pathways via down-regulating miR-22 in MG63 and Saos-2 cells. Highlights Low expression of circ-ITCH is observed in osteosarcoma tissues and cell lines; Overexpression circ-ITCH suppresses miR-22 expression; Circ-ITCH promotes proliferation and represses apoptosis by up-regulating miR-22; Circ-ITCH promotes migration and invasion by up-regulating miR-22; Circ-ITCH activates PTEN/PI3K/AKT and SP-1 pathways by up-regulating miR-22.

Interaction among inflammasome, autophagy and non-coding RNAs: new horizons for drug

Autophagy and inflammasomes are shown to interact in various situations including infectious disease, cancer, diabetes and neurodegeneration. Since multiple layers of molecular regulators contribute to the interplay between autophagy and inflammasome activation, the detail of such interplay remains largely unknown. Non-coding RNAs (ncRNAs), which have been implicated in regulating an expanding list of cellular processes including immune defense against pathogens and inflammatory response in cancer and metabolic diseases, may join in the crosstalk between inflammasomes and autophagy in physiological or disease conditions. In this review, we summarize the latest research on the interlink among ncRNAs, inflammasomes and autophagy and discuss the emerging role of these three in multiple signaling transduction pathways involved in clinical conditions. By analyzing these intriguing interconnections, we hope to unveil the mechanism inter-regulating these multiple processes and ultimately discover potential drug targets for some refractory diseases.

Microarray analysis and functional characterization revealed NEDD4-mediated cardiomyocyte autophagy induced by angiotensin II

Autophagy is a highly regulated intracellular process to maintain cellular homeostasis by degrading damaged proteins and organelles. Dysregulation of autophagic activity in cardiomyocytes is implicated in various heart diseases. However, the underlying mechanisms of cardiomyocyte autophagy are not yet known. In this study, the enhanced cardiomyocyte autophagy was induced by angiotensin II (0.1 μmol/L), demonstrated by the increase of double-membraned autophagosomes, BECN1 expression, and the conversion of LC3-I to LC3-II. Microarray assay showed that a total of 197 genes were differentially expressed in angiotensin II-treated cardiomyocytes, including 22 upregulated and 175 downregulated. Gene ontology functional enrichment analysis showed that nearly 50% of differentially expressed genes were related to metabolism and energy maintenance in biological process. Pathway analysis showed that most frequently represented pathways were involved in metabolism and the citric acid cycle and respiratory electron transport. Based on KEGG database, 10 differentially expressed genes were found to be involved in autophagic signaling pathways. The hub genes with high degree were predicted to regulate cardiomyocyte autophagy activity by PPI network analysis. NEDD4, the top focus hub gene, showed a clear time-dependent increased expression pattern in cardiomyocytes during angiotensin II treatment. Moreover, inhibition of NEDD4 could significantly reduce cardiomyocyte autophagy induced by angiotensin II. In summary, the cardiomyocyte autophagy-related genes were screened by microarray assay combining with bioinformatics analysis. The role of NEDD4 on cardiomyocyte autophagy might provide valuable clues to finding therapeutic targets for heart diseases.

EA15, MIR22, LINC00472 as diagnostic markers for diabetic kidney disease

This study aimed to investigate the molecular mechanisms of diabetic kidney disease (DKD) and to explore new potential therapeutic strategies and biomarkers for DKD. First we analyzed the differentially expressed changes between patients with DKD and the control group using the chip data in Gene Expression Omnibus (GEO) database. Then the gene chip was subjected to be annotated again, so as to screen long noncoding RNAs (lncRNAs) and study expression differences of these lncRNAs in DKD and controlled samples. At last, the function of the differential lncRNAs was analyzed. A total of 252 lncRNAs were identified, and 14 were differentially expressed. In addition, there were 1,629 differentially expressed messenger RNAs (mRNAs) genes, and proliferation and apoptosis adapter protein 15 (PEA15), MIR22, and long intergenic nonprotein coding RNA 472 ( LINC00472) were significantly differentially expressed in DKD samples. Through functional analysis of the encoding genes coexpressed by the three lncRNAs, we found these genes were mainly enriched in type 1 diabetes and autoimmune thyroid disease pathways, whereas in Gene Ontology (GO) function classification, they were also mainly enriched in the immune response, type I interferon signaling pathways, interferon-γ mediated signaling pathways, and so forth. To summary, we identified EA15, MIR22, and LINC00472 may serve as the potential diagnostic markers of DKD.

Role of non-coding RNAs in cardiotoxicity of chemotherapy

The long-time paradoxical situation of non-coding RNAs (ncRNAs) has been terminated for they emerge as executive at full spectrum of gene expression and translation. More recently, it has been demonstrated that some ncRNAs apparently are associated with chemotherapy, causing cardiotoxicity, which taint long-term recovery of patients in growing body of evidence. The current review focused on up-to-date knowledge on regulation change and molecular signaling of ncRNAs, at mean time evaluate their potentials as diagnostic biomarkers or therapeutic targets to monitor and protect cardio function.

An Intervention Target for Myocardial Fibrosis: Autophagy

Myocardial fibrosis (MF) is the result of metabolic imbalance of collagen synthesis and metabolism, which is widespread in various cardiovascular diseases. Autophagy is a lysosomal degradation pathway which is highly conserved. In recent years, research on autophagy has been increasing and the researchers have also become cumulatively aware of the specified association between autophagy and MF. This review highlights the role of autophagy in MF and the potential effects through the administration of medicine.

New and revisited approaches to preserving the reperfused myocardium

Early coronary artery reperfusion improves outcomes for patients with ST-segment elevation myocardial infarction (STEMI), but morbidity and mortality after STEMI remain unacceptably high. The primary deficits seen in these patients include inadequate pump function, owing to rapid infarction of muscle in the first few hours of treatment, and adverse remodelling of the heart in the months that follow. Given that attempts to further reduce myocardial infarct size beyond early reperfusion in clinical trials have so far been disappointing, effective therapies are still needed to protect the reperfused myocardium. In this Review, we discuss several approaches to preserving the reperfused heart, such as therapies that target the mechanisms involved in mitochondrial bioenergetics, pyroptosis, and autophagy, as well as treatments that harness the cardioprotective properties of inhaled anaesthetic agents. We also discuss potential therapies focused on correcting the no-reflow phenomenon and its effect on healing and adverse left ventricular remodelling.

Inhibition of REDD1 Sensitizes Bladder Urothelial Carcinoma to Paclitaxel by Inhibiting Autophagy

Purpose: Regulated in development and DNA damage response-1 (REDD1) is a stress-related protein and is involved in the progression of cancer. The role and regulatory mechanism of REDD1 in bladder urothelial carcinoma (BUC), however, is yet unidentified.Experimental Design: The expression of REDD1 in BUC was detected by Western blot analysis and immunohistochemistry (IHC). The correlation between REDD1 expression and clinical features in patients with BUC were assessed. The effects of REDD1 on cellular proliferation, apoptosis, autophagy, and paclitaxel sensitivity were determined both in vitro and in vivo Then the targeted-regulating mechanism of REDD1 by miRNAs was explored.Results: Here the significant increase of REDD1 expression is detected in BUC tissue, and REDD1 is first reported as an independent prognostic factor in patients with BUC. Silencing REDD1 expression in T24 and EJ cells decreased cell proliferation, increased apoptosis, and decreased autophagy, whereas the ectopic expression of REDD1 in RT4 and BIU87 cells had the opposite effect. In addition, the REDD1-mediated proliferation, apoptosis, and autophagy are found to be negatively regulated by miR-22 in vitro, which intensify the paclitaxel sensitivity via inhibition of the well-acknowledged REDD1-EEF2K-autophagy axis. AKT/mTOR signaling initially activated or inhibited in response to silencing or enhancing REDD1 expression and then recovered rapidly. Finally, the inhibited REDD1 expression by either RNAi or miR-22 sensitizes BUC tumor cells to paclitaxel in a subcutaneous transplant carcinoma model in vivoConclusions: REDD1 is confirmed as an oncogene in BUC, and antagonizing REDD1 could be a potential therapeutic strategy to sensitize BUC cells to paclitaxel. Clin Cancer Res; 24(2); 445-59. ©2017 AACR.

MiRNA Deregulation in Cardiac Aging and Associated Disorders

The prevalence of age-related diseases is increasing dramatically, among which cardiac disease represents the leading cause of death. Aging of the heart is characterized by various molecular and cellular hallmarks impairing both cardiomyocytes and noncardiomyocytes, and resulting in functional deteriorations of the cardiac system. The aging process includes desensitization of β-adrenergic receptor (βAR)-signaling and decreased calcium handling, altered growth signaling and cardiac hypertrophy, mitochondrial dysfunction and impaired autophagy, increased programmed cell death, low-grade inflammation of noncanonical inflammatory cells, and increased ECM deposition. MiRNAs play a fundamental role in regulating the processes underlying these detrimental changes in the cardiac system, indicating that MiRNAs are crucially involved in aging. Among others, MiR-34, MiR-146a, and members of the MiR-17-92 cluster, are deregulated during senescence and drive cardiac aging processes. It is therefore suggested that MiRNAs form possible therapeutic targets to stabilize the aged failing myocardium.

Autophagy Protects Advanced Glycation End Product-Induced Apoptosis and Expression of MMP-3 and MMP-13 in Rat Chondrocytes

Aging is one of the most prominent risk factors for the pathological progression of osteoarthritis (OA). One feature of age-related changes in OA is advanced glycation end products (AGEs) accumulation in articular cartilage. Autophagy plays a cellular housekeeping role by removing dysfunctional cellular organelles and proteins. However, the relationship between autophagy and AGE-associated OA is unknown. The aim of this study is to determine whether autophagy participates in the pathology of AGE-treated chondrocytes and to investigate the exact role of autophagy in AGE-induced cell apoptosis and expression of matrix metalloproteinase- (MMP-) 3 and MMP-13. AGEs induced notable apoptosis that was detected by Annexin V/PI double-staining, and the upregulation of MMP-3 and MMP-13 was confirmed by Western blotting. Autophagy-related proteins were also determined by Western blotting, and chondrocytes were transfected with mCherry-GFP-LC3B-adenovirus to monitor autophagic flux. As a result, autophagy significantly increased in chondrocytes and peaked at 6 h. Furthermore, rapamycin (RA) attenuated AGE-induced apoptosis and expression of MMP-3 and MMP-13 by autophagy activation. In contrast, pretreatment with autophagy inhibitor 3-methyladenine (3-MA) enhanced the abovementioned effects of AGEs. We therefore demonstrated that autophagy is linked with AGE-related pathology in rat chondrocytes and plays a protective role in AGE-induced apoptosis and expression of MMP-3 and MMP-13.