Publication: Immunology
Obesity is a growing epidemic and is associated with metabolic diseases such as insulin resistance, hypertension, and cardiovascular disease. Chronic inflammation is one of the major consequences, which results in dysfunction of adipose tissue in obese patients. Growing evidence suggests a role for MMP-9 as a key component in migration of monocytes/macrophages to adipose tissue. Several studies have showed increased levels of plasma/serum MMP-9 obtained from obese individuals; however the source of MMP-9 production has not been investigated. Therefore, we aimed to identify the sources of MMP-9 production in obese individuals. Plasma concentrations of MMP-9 were measured in samples isolated from 76 individuals by ELISA assay. mRNA expression of MMP-9 in PBMCs was quantified by RT-PCR analysis. MMP-9 expression was also determined in the adipose tissues of these subjects using immunohistochemistry analysis. Overweight and obese individuals showed a significant increase of MMP-9 expression in both PBMCs and adipose tissue when compared with lean individuals (P < 0.05). Interestingly, a remarkable higher expression of MMP-9 was observed in overweight and obese individuals with type II diabetes (P < 0.05). These findings indicate that the PBMCs are the more prone to release and produce MMP-9 in obese individuals. Further investigations are being carried out to determine the cellular compartments within the PBMCs and/or adipose tissue that are directly involved in the modulation and induction of MMP-9 in obese and diabetic individuals.