Exercise induces dynamic changes in intra-articular metabolism and inflammation associated with remodeling of the infrapatellar fat pad in mice.

We hypothesized that daily exercise promotes joint health by upregulating anti-inflammatory mediators via adaptive molecular and metabolic changes in the infrapatellar fat pad (IFP). We tested this hypothesis by conducting time-resolved analyses between 1 and 14 days of voluntary wheel running exercise in C57BL/6J mice. IFP structure and cellularity were evaluated by histomorphology, picrosirius red collagen staining, and flow cytometry analysis of stromal vascular fraction cells.

Sexually dimorphic metabolic effects of a high fat diet on knee osteoarthritis in mice.

Background: Women have a higher risk of developing osteoarthritis (OA) than men, including with obesity. To better understand this disparity, we investigated sex differences in metabolic and inflammatory factors associated with OA using a diet-induced mouse model of obesity. We hypothesized that 20 weeks of high-fat diet (HFD) would induce sexually dimorphic changes in both systemic and local risk factors of knee OA.

Sex-specific effects of injury and beta-adrenergic activation on metabolic and inflammatory mediators in a murine model of post-traumatic osteoarthritis.

Objective: Metabolic processes are intricately linked to the resolution of innate inflammation and tissue repair, two critical steps for treating post-traumatic osteoarthritis (PTOA). Based on lipolytic and immunoregulatory actions of norepinephrine, we hypothesized that intra-articular β-adrenergic receptor (βAR) stimulation would suppress PTOA-associated inflammation in the infrapatellar fat pad (IFP) and synovium.

Design: We used the βAR agonist isoproterenol to perturb intra-articular metabolism 3.

Imaging mass cytometry reveals tissue-specific cellular immune phenotypes in the mouse knee following ACL injury.

Objective: To develop an imaging mass cytometry method for identifying complex cell phenotypes, inter-cellular interactions, and population changes in the synovium and infrapatellar fat pad (IFP) of the mouse knee following a non-invasive compression injury.

Design: Fifteen male C57BL/6 mice were fed a high-fat diet for 8 weeks prior to random assignment to sham, 0.88 ​mm, or 1.

Sirt3 Promotes Chondrogenesis, Chondrocyte Mitochondrial Respiration and the Development of High-Fat Diet-Induced Osteoarthritis in Mice.

Understanding how obesity-induced metabolic stress contributes to synovial joint tissue damage is difficult because of the complex role of metabolism in joint development, maintenance, and repair. Chondrocyte mitochondrial dysfunction is implicated in osteoarthritis (OA) pathology, which motivated us to study the mitochondrial deacetylase enzyme sirtuin 3 (Sirt3). We hypothesized that combining high-fat-diet (HFD)-induced obesity and cartilage Sirt3 loss at a young age would impair chondrocyte mitochondrial function, leading to cellular stress and accelerated OA.