Exposure to pressure stimulus enhances succinate dehydrogenase activity in L6 myoblasts

Long-term hypoxia stress-induced oxidative stress, cell apoptosis, and immune response in the intestine of Pelteobagrus vachelli

Hypoxia is a common phenomenon in aquaculture. With the dissolved oxygen (DO) 3.75 ± 0.25 mg O2 /L for hypoxia group and 7.25 ± 0.25 mg O2 /L for control group for 30, 60, and 90 days, long-term hypoxia stress was used to investigate the oxidative stress, apoptosis, and immunity in the intestine of Pelteobagrus vachelli. According to the results of measurement of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), and catalase (CAT) activities and malondialdehyde (MDA) content, the oxidative stress ability of the intestine was activated at 30 days and impaired at 60 and 90 days. The upregulation of Bcl-2-associated x (Bax); downregulation of B cell lymphoma-2 (Bcl-2); increased activities of caspase-3, caspase-9, and Na+-K+-ATPase; decreased activities of succinate dehydrogenase (SDH); and the release of cytochrome c (Cyt-c) in mitochondria revealed that hypoxia induced the apoptosis. Moreover, heat shock protein 70 (HSP 70), heat shock protein 90 (HSP 90), immunoglobulin M (IgM), and C-lysozyme (C-LZM) were activated to inhibit apoptosis, but the immunoregulatory function might be damaged at 60 and 90 days. This study provides a theoretical foundation for understanding the mechanisms of hypoxia stress and aquaculture management of P. vachelli.

Skeletal muscle is an endocrine organ

Skeletal muscle plays a key role in postural retention as well as locomotion for maintaining the physical activities of human life. Skeletal muscle has a second role as an elaborate energy production and consumption system that influences the whole body's energy metabolism. Skeletal muscle is a specific organ that engenders a physical force, and exercise training has been known to bring about multiple benefits for human health maintenance and/or improvement. The mechanisms underlying the improvement of the human physical condition have been revealed: skeletal muscle synthesizes and secretes multiple factors, and these muscle-derived factors, so-called as myokines, exert beneficial effects on peripheral and remote organs. In this short review, we focus on the third aspect of skeletal muscle function - namely, the release of multiple types of myokines, which constitute a broad network for regulating the function of remote organs as well as skeletal muscle itself. We conclusively show that skeletal muscle is one of the endocrine organs and that understanding the mechanisms of production and secretion of myokines may lead to a new pharmacological approach for treatment of clinical disorders.

KIOM-4 Protects against Oxidative Stress-Induced Mitochondrial Damage in Pancreatic β-cells via Its Antioxidant Effects

The protective effect of KIOM-4, a mixture of plant extracts, was examined against streptozotocin (STZ)-induced mitochondrial oxidative stress in rat pancreatic β-cells (RINm5F). KIOM-4 scavenged superoxide and hydroxyl radicals generated by xanthine/xanthine oxidase and Fenton reaction (FeSO(4)/H(2)O(2)), respectively, in a cell-free chemical system. In addition, a marked increase in mitochondrial reactive oxygen species (ROS) was observed in STZ-induced diabetic cells; this increase was attenuated by KIOM-4 treatment. Mitochondrial manganese superoxide dismutase (Mn SOD) activity and protein expression were down-regulated by STZ treatment and up-regulated by KIOM-4 treatment. In addition, NF-E2 related factor 2 (Nrf2), a transcription factor for Mn SOD, was up-regulated by KIOM-4. KIOM-4 prevented STZ-induced mitochondrial lipid peroxidation, protein carbonyl and DNA modification. Moreover, KIOM-4 treatment restored the loss of mitochondrial membrane potential (Δψ) that was induced by STZ treatment, and inhibited the translocation of cytochrome c from the mitochondria to the cytosol. In addition, KIOM-4 treatment elevated the level of ATP, succinate dehydrogenase activity and insulin level, which were reduced by STZ treatment. These results suggest that KIOM-4 exhibits a protective effect through its antioxidant effect and the attenuation of mitochondrial dysfunction in STZ-induced diabetic cells.