Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Obesity affects the chondrocyte responsiveness to leptin in patients with osteoarthritis. | Pallu et al. Arthritis Research Therapy 2010 12 R112 http content 12 3 R112 RESEARCH ARTICLE Open Access Obesity affects the chondrocyte responsiveness to leptin in patients with osteoarthritis Stéphane Pallu 1 Pierre-Jean Francin 2 Cécile Guillaume 2 Pascale Gegout-Pottie2 Patrick Netter2 Didier Mainard2 Bernard Terlain2 and Nathalie Presle 2 Abstract Introduction Increasing evidence support the regulatory role of leptin in osteoarthritis OA . As high circulating concentrations of leptin disrupt the physiological function of the adipokine in obese individuals the current study has been undertaken to determine whether the elevated levels of leptin found in the joint from obese OA patients also induce changes in the chondrocyte response to leptin. Methods Chondrocytes isolated from OA patients with various body mass index BMI were treated with 20 100 or 500 ng ml of leptin. The expression of cartilage-specific components aggrecan type 2 collagen as well as regulatory IGF-1 TGFp MMP-13 TIMP 2 or inflammatory COX-2 iNOS IL-1 factors was investigated by real-time PCR to evaluate chondrocyte responsiveness to leptin. Furthermore the effect of body mass index BMI on leptin signalling pathways was analyzed with an enzyme-linked immunosorbent assay for STATs activation. Results Leptin at 20 ng ml was unable to modulate gene expression in chondrocytes except for MMP-13 in obese OA patients. Higher leptin levels induced the expression of IGF-1 type 2 collagen TIMP-2 and MMP-13. However the activity of the adipokine was shown to be critically dependent on both the concentration and the BMI of the patients with a negative association between the activation of regulated genes and BMI for 100 ng ml of adipokine but a positive association between chondrocyte responsiveness and BMI for the highest leptin dose. In addition the gene encoding MMP-13 was identified as a target of leptin for chondrocytes originated from obese patients while mRNA level of TIMP-2 .
