Metformin（Met） is a commonly used drug in the treatment of type 2 diabetes. Currently, it has been found that Met can effectively reduce the incidence of stroke and exert anti-inflammatory effects. However, its role in ischemia-reperfusion (I/R) induced nerve injury remains unclear. This study aims to investigate the neuroprotective effects of Met in I/R-induced neuron injury as well as the underlying mechanism.A middle cerebral artery occlusion (MCAO) model was established in SD rats, which were then treated with different doses of Met.Neurological deficits of rats were measured at different times post-surgery. TTC staining to observe the volume of cerebral infarction.HE staining was performed to observe pathological changes of brain tissues .Immunohistochemistry was performed to observe the expression of inflammatory factors in the cerebral tissues .qRT-PCR method was used to detect the relative expression of PI3K、Akt mRNA in cells after 24 h of drug action.Western blot method was used to detect the expression of PI3K、p-PI3K、Akt and p-Akt in hippocampus.What’s more, in vitro experiments were performed on BV2 microglia to verify the role of Met against oxygen-glucose deprivation (OGD). As a result, Met dose-dependently attenuated neurological deficits and neuronal apoptosis. Besides, Met administration also significantly reduced BV2 cells apoptosis and inflammatory response. Mechanistically, Met inactivated PI3K/Akt pathway induced by I/R and OGD, while upregulated PI3K. In conclusion, Met protected rats from cerebral I/R injury via reducing neuronal apoptosis and microglial inflammation through PI3K/Akt pathway.

Objective: The purpose of this study was to investigate the effect of aerobic exercise on myocardial injury induced by I/ R in rats by regulating SIRT3/SOD2/NF-κB signaling pathway, and to provide theoretical guidance for clinical treatment of myocardial I/R injury.Methods:SPF Male Sprague-Dawley(SD) rats were randomly assigned to 4 groups: Sham operation group(n=10), I/R group(n=10), Aerobic exercise group(n=10)and Aerobic exercise+κ-receptor antagonist group(Pro DTC group，n=10). The left anterior descending coronary artery(LAD) of rats was ligated and re-canalized to establish I/R rat model. Hematoxylin-eosin(HE) staining was performed to examine histological morphology in myocardial tissues of each group. The biological analysis was performed to measure cTnI、CK-MB、BNP levels in blood samples of each group. The expression levels of SOD2, TLR4, and p65 in myocardial tissues were measured by immunohistochemical assay. The influence of aerobic exercise on Beclin-1 、LC3II/I、SIRT3, TLR4, and phosphorylated p65 was measured by Western blotting.Results: The result of histological morphology examination revealed that Aerobic exercise group exhibited integrated cardiac myofilament, less inflammatory cell infiltration, as much as significantly decreased cellular edema. Measurement of cTnI、CK-MB、BNP revealed that oxycodone post-treatment reduces the injury of myocardial tissues(P<0.05). Immunohistochemical staining results revealed that aerobic exercise clearly decreased the expression of TLR4 and p65, and increased the expression of SOD2(P<0.05). Besides, Western blotting revealed that aerobic exercise down-regulated the expression of Beclin-1 、LC3II/I、TLR4 and phosphorylated p65, up-regulated the expression of SIRT3(P<0.05).Conclusions: Aerobic exercise significantly improved myocardial I/R injury. The mechanisms may be associated with activating κ-receptor to regulate SIRT3/SOD2/NF-κB pathway.

Knee Osteoarthritis (KOA) is a chronic disease characterized by progressive disability and joint pain. Meniscus chondrocytes apoptosis is the main cause of reduced chondrocyte number and self-repair function. The purpose of this study was to investigate the role of miR-27b-3p in KOA.In this study, we found that the expression of miR-27b-3p was downregulated in cultured IL-1β treated chondrocyte and cartilage tissues in KOA. KOA overexpression evidently reduced IL-1β induced chondrocyte apoptosis and caspase-3 and caspase-9 expression.The upregulated iNOS and COX-2 mRNA and proteins expression was also inhibited by miR-27b-3p mimics. The expression of nitric oxide, PGE2, TNF-α and IL-6 was also inhibited by miR-27b-3p mimics. The target gene of miR-27b-3p was confirmed to be BDNF. TrkB/CREB pathway was proved to be the downstream pathway of miR-27b-3p/BDNF axis.The apoptotic cell percentage and nitric oxide, PGE2, TNF-α and IL-6 expression was induced by BDNF+IL-1β. This induction was inhibited by miR-27b-3p mimics. The cartilage tissues stained with safranin O results showed miR-27b-3p greatly decreased KOA induced cartilage degradation. The expression of BDNF、TrkB and p-CREB was inhibited by len-miR-27b-3p. MiR-27b-3p also reduced the expression of TNF-α、IL-6 and Bax, and increased Bcl-2 expression. These results indicated miR-27b-3p could applied to inhibit the development of KOA and miR-27b-3p/BDNF/TrkB/CREB pathway could serve as novel treatment target to handle KOA.

The meniscus is a meniscus-shaped fibrocartilage tissue located between the femur and tibia，it is mainly composed of meniscus cells and related extracellular matrix.The synovial limbus area of the knee joint capsule near the meniscus is divided into red areas with rich blood vessels and white areas with less blood supply according to the distribution of blood vessels,there is a transition zone called the red and white zone between the two;Red zone has better self-repair ability,The injury in this area can be treated by conservative treatment or surgical suture;Once the white area of the meniscus is torn and involves the free edge area,It is often necessary to partially remove the damaged meniscus.When most of the entire meniscus is severely torn and involved,not only the course of the disease is very long, but it cannot be repaired by sutures,Often a subtotal or total meniscus resection is required,whether it is a partial meniscus resection, a subtotal meniscus resection or a complete resection.In the later period, it may cause quadriceps atrophy and osteoarthritis (OA）.OA is a refractory multi-system disease,involve the patient’s peripheral joints,it has high disability and teratogenicity, and is very harmful to human health.Chondrocyte pyrolysis, degradation, and inflammation play a vital role in the destruction of OA articular cartilage and chondrocyte apoptosis.Meniscus stem cells have strong proliferation and differentiation ability,has become one of the hot spots in the field of meniscus repair,this article studies the role of meniscal stem cells in the development of OA.