Cardiac shock wave therapy protects cardiomyocytes from hypoxia‑induced injury by modulating miR‑210

Effects of Extracorporeal Shockwave Therapy on Functional Recovery and Circulating miR-375 and miR-382-5p after Subacute and Chronic Spinal Cord Contusion Injury in Rats

Extracorporeal shockwave therapy (ESWT) can stimulate processes to promote regeneration, including cell proliferation and modulation of inflammation. Specific miRNA expression panels have been established to define correlations with regulatory targets within these pathways. This study aims to investigate the influence of low-energy ESWT—applied within the subacute and chronic phase of SCI (spinal cord injury) on recovery in a rat spinal cord contusion model. Outcomes were evaluated by gait analysis, µCT and histological analysis of spinal cords. A panel of serum-derived miRNAs after SCI and after ESWT was investigated to identify injury-, regeneration- and treatment-associated expression patterns. Rats receiving ESWT showed significant improvement in motor function in both a subacute and a chronic experimental setting. This effect was not reflected in changes in morphology, µCT-parameters or histological markers after ESWT. Expression analysis of various miRNAs, however, revealed changes after SCI and ESWT, with increased miR-375, indicating a neuroprotective effect, and decreased miR-382-5p potentially improving neuroplasticity via its regulatory involvement with BDNF. We were able to demonstrate a functional improvement of ESWT-treated animals after SCI in a subacute and chronic setting. Furthermore, the identification of miR-375 and miR-382-5p could potentially provide new targets for therapeutic intervention in future studies.

Extracorporeal shockwave relieves endothelial injury and dysfunction in steroid-induced osteonecrosis of the femoral head via miR-135b targeting FOXO1: in vitro and in vivo studies

Injury and dysfunction of endothelial cells (ECs) are closely related to the pathogenesis of steroid-induced osteonecrosis of the femoral head (ONFH), while MicroRNAs (miRNAs) play an essential role in the processes. Extracorporeal shockwave treatment (ESWT) has been used in the non-invasive treatment of various diseases including musculoskeletal and vascular disorders. In particular, ESWT with low energy levels showed a beneficial effect in ischemic tissues. However, there has been no comprehensive assessment of the effect of ESWT and miRNAs on steroid-induced ONFH. In the present study, we investigated the role and mechanism of ESWT and miRNAs both in vitro and in vivo. Using a steroid-induced ONFH rat model, we found that ESWT significantly enhances proliferation and angiogenesis as well as alleviates apoptosis. In two types of ECs, ESWT can promote cell proliferation and migration, enhance angiogenesis, and inhibit apoptosis. Notably, our study demonstrates that miR-135b is downregulated and modulated forkhead box protein O1 (FOXO1) in ECs treated with dexamethasone. Remarkably, both miR-135b knockdown and FOXO1 overexpression reversed the beneficial effect of ESWT on ECs. Additionally, our data suggest that ESWT activates the FOXO1-related pathway to impact proliferation, apoptosis, and angiogenesis. Taken together, this study indicates that ESWT relieves endothelial injury and dysfunction in steroid-induced ONFH via miR-135b targeting FOXO1.

Hypoxia-Induced miR-210 Overexpression Promotes the Differentiation of Human-Induced Pluripotent Stem Cells to Hepatocyte-Like Cells on Random Nanofiber Poly-L-Lactic Acid/Poly (ε-Caprolactone) Scaffolds

An alternative treatment to liver transplantation includes the use of differentiated stem cells. Hypoxia has been shown to endow human-induced pluripotent stem cells (hiPSCs) with enhanced hepatic differentiation. We have investigated a new strategy for hepatocyte differentiation from hiPSCs using a three-step differentiation protocol with lentiviral overexpression of hypoxia-microRNA-210 of cells grown on a hybrid scaffold. We analyzed the transduction of the miR-210 lentiviral and definitive endoderm and pluripotency gene markers, including SRY-box 17 (SOX17), forkhead box A2 (FOXA2), and octamer-binding transcription factor 4 (OCT-4) by Real-Time PCR and fluorescent microscope. The scanning electron microscopy (SEM) examined the 3D cell morphological changes. Immunocytochemistry staining was used together with assays for aspartate aminotransferase, alanine aminotransferase, and urea secretion to analyze hepatocyte biomarkers and functional markers consisting of α-fetoprotein (AFP), low-density lipoprotein (LDL) uptake, fat accumulation, and glycogen. The flow cytometry analyzed the generation of reactive oxygen species (ROS). Compared to cells transfected with the blank lentiviral vectors as a control, overexpressing miR-210 was at higher levels in hiPSCs. The expression of endodermal genes and glycogen synthesis significantly increased in the differentiated lentiviral miR-210 cells without any differences regarding lipid storage level. Additionally, cells containing miR-210 showed a greater expression of ALB, LDL, AST, ALT, urea, and insignificant lower AFP and ROS levels after 18 days. However, SEM showed no significant differences between cells under the differentiation process and controls. In conclusion, the differentiation of hiPSCs to hepatocyte-like cells under hypoxia miR-210 may be a suitable method for cell therapy and regenerative medicine.

The microRNA-210/Casp8ap2 Axis Alleviates Hypoxia-Induced Myocardial Injury by Regulating Apoptosis and Autophagy

Coronary heart disease (CHD) is a serious condition comprising atherosclerosis-mediated ischaemic and hypoxic myocardial injury. This study aimed to investigate the mechanism of the miR-210/Casp8ap2 signalling pathway in hypoxic myocardial cells. mRNA and protein expression levels were determined by quantitative real-time PCR and western blotting, respectively. MTT was used to evaluate cell survival, and flow cytometry was used to assess apoptosis and the cell cycle distribution. The interaction between miR-210 and -Casp8ap2 was detected by dual-luciferase reporter assay. As a result, overexpression of miR-210 significantly inhibited apoptosis and reduced the proportion of cells in G1 phase. Moreover, miR-210 suppressed autophagy by upregulating p62 levels and reducing the LC3-II/I ratio in hypoxic cardiomyocytes. miR-210 regulated apoptosis and autophagy by directly targeting Casp8ap2. Furthermore, the expression levels of Casp8ap2, Cleaved caspase 8, Cleaved caspase 3and Beclin-1 were all decreased in response to miR-210. In short, our results suggest that miR-210 exerts anti-apoptotic and anti-autophagic effects in hypoxic cardiomyocytes, which alleviates myocardial injury in response to hypoxia.

Hyperoside protects cardiomyocytes against hypoxia‑induced injury via upregulation of microRNA‑138

Following hypoxia, cardiomyocytes are susceptible to damage, against which microRNA (miR)‑138 may act protectively. Hyperoside (Hyp) is a Chinese herbal medicine with multiple biological functions that serve an important role in cardiovascular disease. The aim of the present study was to investigate the role of Hyp in hypoxic cardiomyocytes and its effect on miR‑138. A hypoxia model was established in both H9C2 cells and C57BL/6 mice, which were stimulated by Hyp. The expression levels of miR‑138 were increased in the hypoxic myocardium in the presence of Hyp at concentrations of >50 µmol/l in vivo and >50 mg/kg in vitro. Using Cell Counting Kit‑8 and 5‑ethynyl‑2'‑deoxyuridine assays, it was observed that Hyp improved hypoxia‑induced impairment of cell proliferation. Cell apoptosis was evaluated by flow cytometry and a TUNEL assay. The number of apoptotic cells in the Hyp group was lower than that in the control group. As markers of myocardial injury, the levels of lactate dehydrogenase, creatine kinase‑myocardial band isoenzyme and malondialdehyde were decreased in the Hyp group compared with the control group, whereas the levels of superoxide dismutase were increased. A marked decrease in the levels of cleaved caspase‑3 and cleaved poly(ADP) ribose polymerase and a marked increase in expression levels of Bcl‑2 were observed in the presence of Hyp. However, miR‑138 inhibition by antagomir attenuated the protective effects of Hyp. Furthermore, Hyp treatment was associated with marked downregulation of mixed lineage kinase 3 and lipocalin‑2, but not pyruvate dehydrogenase kinase 1, in hypoxic H9C2 cells. These findings demonstrated that Hyp may be beneficial for myocardial cell survival and may alleviate hypoxic injury via upregulation of miR‑138, thereby representing a promising potential strategy for clinical cardioprotection.