Modulation of the Inflammatory Process by Hypercholesterolemia in Osteoarthritis.

Several studies have linked metabolic syndrome to the development of osteoarthritis (OA) through hypercholesterolemia, one of its components. However, epidemiological studies showed contradictory results, and it is not clear how hypercholesterolemia itself, or oxidized LDL (oxLDL)-a pathological molecule potentially involved in this relationship-could be affecting OA. The objectives of this study were to investigate the effect of hypercholesterolemia induced by high-fat diet (HFD) in cartilage from OA rabbits, and how oxLDL affect human chondrocyte inflammatory and catabolic responses.

Compensatory anabolic signaling in the sarcopenia of experimental chronic arthritis.

Inflammatory activity in rheumatoid arthritis may alter the regulation of muscle mass leading to a secondary sarcopenia, commonly termed rheumatoid cachexia (RC). We characterized alterations to muscle structure and various pro-inflammatory, catabolic and regenerative markers in an animal model of RC. Antigen induced arthritis (AiA) was performed in 20 male adult rabbits.

The adipokine lipocalin-2 in the context of the osteoarthritic osteochondral junction.

Obesity and osteoarthritis (OA) form a vicious circle in which obesity contributes to cartilage destruction in OA, and OA-associated sedentary behaviour promotes weight gain. Lipocalin-2 (LCN2), a novel adipokine with catabolic activities in OA joints, contributes to the obesity and OA pathologies and is associated with other OA risk factors. LCN2 is highly induced in osteoblasts in the absence of mechanical loading, but its role in osteoblast metabolism is unclear.

Aromatase expression in human chondrocytes: An induction due to culture.

Objectives: Despite the high prevalence of osteoarthritis (OA) in postmenopausal women, a relationship between circulating estrogen levels and the development of OA has not been found. Therefore, the purpose of this study was to evaluate the expression and activity of aromatase, a key enzyme in local production of estrogens, in human OA cultured articular chondrocytes, and to determine the physiological relevance of this enzyme in cartilage.

Methods: Human OA articular chondrocytes were isolated and cultured.

TLR4 signalling in osteoarthritis--finding targets for candidate DMOADs.

Osteoarthritis (OA), the most common rheumatic disease, is characterized by joint-space narrowing due to progressive cartilage degradation and alterations in subchondral bone and the synovial membrane. These articular disturbances can have severe consequences, including pain, disability and loss of joint architectural integrity. Although the aetiology of OA is not understood, chondrocyte-mediated inflammatory responses triggered by the activation of innate immune receptors by damage-associated molecules are thought to be involved.

SDF-1 signaling: a promising target in rheumatic diseases.

Introduction: Stromal cell-derived factor 1 (SDF-1) is a potent chemoattractant cytokine with various biological functions such as stem cell mobilization, inflammatory cell infiltration and angiogenesis. Therefore, it has also been implicated in several pathological processes, from ischemic conditions to cancer. Remarkably, SDF-1 and its receptors, CXCR4 and CXCR7, are also present in joint tissues, where they play a role in the pathogenesis of rheumatoid arthritis (RA) and osteoarthritis (OA).

Lipid transport and metabolism in healthy and osteoarthritic cartilage.

Cartilage is an avascular tissue and cartilage metabolism depends on molecule diffusion from synovial fluid and subchondral bone. Thus, nutrient availability is limited by matrix permeability according to the size and charge of the molecules. Matrix composition limits the access of molecules to chondrocytes, determining cell metabolism and cartilage maintenance.

6-Shogaol inhibits chondrocytes' innate immune responses and cathepsin-K activity.

Scope: Ginger has long been used in traditional Asian medicine to treat osteoarthritis. Indeed, scientific research has reported that ginger derivatives (GDs) have the potential to control innate immune responses. Given the widespread use and demonstrated properties of GDs, we set out to study their anti-inflammatory and anticatabolic properties in chondrocytes.

Circulating endothelial progenitor cells are reduced in rat oxygen-induced retinopathy despite a retinal SDF-1/CXCR4 and VEGF proangiogenic response.

Aims: The purpose of this study is to investigate circulating endothelial progenitor cells (EPCs) and the signaling pathways involved in their recruitment in the ischemic retina of the 50/10 rat model of oxygen-induced retinopathy (OIR).

Main Methods: Within 12h after birth, litters of Sprague-Dawley rats and their mothers were exposed to alternating oxygen concentrations, followed by a room air exposition, to induce OIR. Retinopathy was quantified by ADPase stain in flat-mounted retinas and pre-ILM nuclei count in retinal sections.