Mitochondrial oxidative stress impairs contractile function but paradoxically increases muscle mass via fibre branching.

Background: Excess reactive oxygen species (ROS) and muscle weakness occur in parallel in multiple pathological conditions. However, the causative role of skeletal muscle mitochondrial ROS (mtROS) on neuromuscular junction (NMJ) morphology and function and muscle weakness has not been directly investigated.

Methods: We generated mice lacking skeletal muscle-specific manganese-superoxide dismutase (mSod2KO) to increase mtROS using a cre-Lox approach driven by human skeletal actin.

Profibrotic Infrapatellar Fat Pad Remodeling Without M1 Macrophage Polarization Precedes Knee Osteoarthritis in Mice With Diet-Induced Obesity.

Objective: To test the hypothesis that high-fat (HF) diet-induced obesity increases proinflammatory cytokine expression, macrophage infiltration, and M1 polarization in the infrapatellar fat pad (IFP) prior to knee cartilage degeneration.

Methods: We characterized the effect of HF feeding on knee OA pathology, body adiposity, and glucose intolerance in male C57BL/6J mice and identified a diet duration that induces metabolic dysfunction prior to cartilage degeneration. Magnetic resonance imaging and histomorphology were used to quantify changes in the epididymal, subcutaneous, and infrapatellar fat pads and in adipocyte sizes.

Streptococcus induces circulating CLA(+) memory T-cell-dependent epidermal cell activation in psoriasis.

Streptococcal throat infection is associated with a specific variant of psoriasis and with HLA-Cw6 expression. In this study, activation of circulating psoriatic cutaneous lymphocyte-associated antigen (CLA)(+) memory T cells cultured together with epidermal cells occurred only when streptococcal throat extracts were added. This triggered the production of Th1, Th17, and Th22 cytokines, as well as epidermal cell mediators (CXCL8, CXCL9, CXCL10, and CXCL11).