Liraglutide ameliorates COCl2-induced oxidative stress and apoptosis in H9C2 cells via regulating cell autophagy

Liraglutide attenuates palmitate-induced apoptosis via PKA/β-catenin/Bcl-2/Bax pathway in MC3T3-E1 cells

Liraglutide (LRG), one agonist of glucagon-like peptide-1 receptor (GLP1R), has multiple lipid-lowering effects in type 2 diabetes mellitus, however, studies on the role of LRG in saturated fatty acid-induced bone loss are limited. Therefore, our aim was to investigate whether LRG reduces palmitate (PA)-induced apoptosis and whether the mechanism involves PKA/β-catenin/Bcl-2/Bax in osteoblastic MC3T3-E1 cells. MC3T3-E1 cells were treated with different concentrations of PA, LRG, or pretreated with Exendin 9-39 and H89, cell viability, intracellular reactive oxygen species (ROS), cAMP levels, apoptosis and the expression of protein kinase A (PKA) and phosphorylation of PKA (p-PKA), β-catenin and phosphorylation of β-catenin (Ser675)(p-β-catenin), GLP1R, cleaved-capase 3, Bcl2-Associated X Protein (Bax) and B-cell lymphoma-2 (Bcl-2) along with expression of Osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) were evaluated. PA treatment inhibited cell proliferation and cAMP levels, elevated intracellular ROS levels and promoted apoptosis, increased protein expressions of RANKL, Bax and cleaved-caspase3, meanwhile decreased protein expression of OPG and Bcl-2 in a dose-dependent manner. LRG inverted PA-induced apoptosis, increased cAMP levels, promoted expression of p-PKA, p-β-catenin (Ser675) and reversed these gene expressions via increasing GLP1R expression. Pretreatment of the cells with Exendin 9-39 and H89 partially eradicated the protective effect of LRG on PA-induced apoptosis and gene expressions. Therefore, these findings indicated that LRG attenuates PA-induced apoptosis possibly by GLP1R-mediated PKA/β-catenin/Bcl-2/Bax pathway in MC3T3-E1 cells. Our results point to LRG as a new strategy to attenuate bone loss associated with high fat diet beyond its lipid-lowering actions. LRG inhibits PA-mediated apoptosis via GLP1R-mediated PKA/β-catenin/Bcl-2/ Bax pathway, while possibly enhances PA-inhibited differentiation by regulating the expression of OPG and RANKL.

Ameliorative Effects of Extracellular Vesicles Derived from Mesenchymal Stem Cells on Apoptosis and Differentiation of Osteoblasts Treated with CoCl2

Severe osteoporotic fracture occurring in sites with inadequate blood supply can cause irreversible damage to cells, particularly osteoblasts, with current drug and surgical interventions exhibiting limitations for elderly individuals. As participants mediating intercellular communication, extracellular vesicles (EVs) are rarely reported to play functional roles in osteoblasts under hypoxia. Our study mainly investigated the effects of bone marrow mesenchymal stem cells-derived EVs (BMSCs-EVs) on apoptosis and differentiation of osteoblasts treated with CoCl2. Primary rat BMSCs and osteoblasts were extracted as required for the following experiments. Cell counting kit 8 assay was used to explore the concentration of CoCl2 for treating osteoblasts, and we found that 100 μM CoCl2 was appropriate to treat osteoblasts for 48 hours. The analysis of flow cytometer showed that CoCl2-treated osteoblasts apoptosis can be ameliorated when cocultured with BMSCs-EVs. Further findings revealed that reactive oxygen species (ROS) was related to CoCl2-induced apoptosis. In addition, our results demonstrated that EVs exerted an important role in increasing expression levels of ALP, BMP-2, OCN, and OSTERIX under hypoxia. Similarly, the functional effects of BMSCs-EVs were observed on the osteoblasts mineralization. In summary, these findings provide insight that BMSCs-EVs might decrease the effect of CoCl2-induced apoptosis through inhibiting ROS, and promote osteogenic differentiation under hypoxia.

Shenxiong glucose injection inhibits oxidative stress and apoptosis to ameliorate isoproterenol-induced myocardial ischemia in rats and improve the function of HUVECs exposed to CoCl2

Background: Shenxiong Glucose Injection (SGI) is a traditional Chinese medicine formula composed of ligustrazine hydrochloride and Danshen (Radix et rhizoma Salviae miltiorrhizae; Salvia miltiorrhiza Bunge, Lamiaceae). Our previous studies and others have shown that SGI has excellent therapeutic effects on myocardial ischemia (MI). However, the potential mechanisms of action have yet to be elucidated. This study aimed to explore the molecular mechanism of SGI in MI treatment. Methods: Sprague-Dawley rats were treated with isoproterenol (ISO) to establish the MI model. Electrocardiograms, hemodynamic parameters, echocardiograms, reactive oxygen species (ROS) levels, and serum concentrations of cardiac troponin I (cTnI) and cardiac troponin T (cTnT) were analyzed to explore the protective effect of SGI on MI. In addition, a model of oxidative damage and apoptosis in human umbilical vein endothelial cells (HUVECs) was established using CoCl₂. Cell viability, Ca²⁺ concentration, mitochondrial membrane potential (MMP), apoptosis, intracellular ROS, and cell cycle parameters were detected in the HUVEC model. The expression of apoptosis-related proteins (Bcl-2, Caspase-3, PARP, cytoplasmic and mitochondrial Cyt-c and Bax, and p-ERK1/2) was determined by western blotting, and the expression of cleaved caspase-3 was analyzed by immunofluorescence. Results: SGI significantly reduced ROS production and serum concentrations of cTnI and cTnT, reversed ST-segment elevation, and attenuated the deterioration of left ventricular function in ISO-induced MI rats. In vitro, SGI treatment significantly inhibited intracellular ROS overexpression, Ca²⁺ influx, MMP disruption, and G2/M arrest in the cell cycle. Additionally, SGI treatment markedly upregulated the expression of anti-apoptotic protein Bcl-2 and downregulated the expression of pro-apoptotic proteins p-ERK1/2, mitochondrial Bax, cytoplasmic Cyt-c, cleaved caspase-3, and PARP. Conclusion: SGI could improve MI by inhibiting the oxidative stress and apoptosis signaling pathways. These findings provide evidence to explain the pharmacological action and underlying molecular mechanisms of SGI in the treatment of MI.

Protective effects of safranal on hypoxia/reoxygenation-induced injury in H9c2 cardiac myoblasts via the PI3K/AKT/GSK3β signaling pathway

Safranal (SFR), an active ingredient extracted from saffron, exhibits a protective effect on the cardiovascular system. However, the mechanism of SFR against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury has previously not been investigated in vitro. The aim of the present study was therefore to observe the protective effects of SFR on H/R-induced cardiomyocyte injury and to explore its mechanisms. A H/R injury model of H9c2 cardiac myoblasts was established by administering 800 µmol/l CoCl₂ to H9c2 cells for 24 h and reoxygenating the cells for 4 h to induce hypoxia. H9c2 cardiac myoblasts were pretreated with SFR for 12 h to evaluate the associated protective effects. A Cell Counting Kit-8 assay was used for cell viability detection, and the expression levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), glutathione peroxidase (GSH-px), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and caspase-3, and the intracellular Ca²⁺ concentration were measured using the corresponding commercial kits. Levels of reactive oxygen species (ROS) in the cells were detected using 2,7-dichlorodihydrofluorescein diacetate. Flow cytometry was used to determine the degree of apoptosis and the level of mitochondrial membrane potential (MMP). Moreover, the expression levels of phosphorylated (p-)PI3K, AKT, p-AKT, glycogen synthase kinase 3β (GSK3β), p-GSK3β, Bcl-2, Bax, caspase-3 and cleaved caspase-3 were measured using western blot analysis. Results of the present study demonstrated that the H9c2 cardiac myoblasts treated with SFR exhibited significantly improved levels of viability and significantly reduced levels of ROS, compared with the H/R group. Furthermore, compared with the H/R group, SFR treatment significantly increased the MMP levels and antioxidant enzyme levels, including CAT, SOD and GSH-px; whereas the levels of CK-MB, LDH, MDA and intracellular Ca²⁺ concentration were significantly decreased. Moreover, the results of the present study demonstrated that SFR significantly reduced caspase-3, cleaved caspase-3 and Bax protein expression levels, but upregulated the Bcl-2 protein expression levels. SFR also increased the protein expressions of PI3K/AKT/GSK3β. In summary, the results suggested that SFR may exert a protective effect against H/R-induced cardiomyocyte injury, which occurs in connection with the inhibition of oxidative stress and apoptosis via regulation of the PI3K/AKT/GSK3β signaling pathway.