Lower ratio of high-molecular-weight adiponectin level to total may be associated with coronary high-risk plaque

The Role of Adipocytokines in Coronary Atherosclerosis

PURPOSE OF REVIEW

The aim of this review is to overview the pathophysiological role of adipocytokines in atherogenesis, focusing on their potential role as biomarkers of coronary disease.

RECENT FINDINGS

Several lines of evidence indicated adipose tissue not only as depot but rather as an endocrine organ. In this context, the balance between pro- and anti-inflammatory adipocytokines has been shown to critically regulate vascular homeostasis in both physiological and pathophysiological conditions. Overweight and obesity are characterized by dysfunctional adipose tissue and then the prevalence of pro-inflammatory mediators, with a detrimental effect on vascular health. As opposite to adiponectin, pro-inflammatory adipocytokines, such as leptin and resistin, promote endothelial dysfunction and inflammatory processes involved in atherosclerotic plaque progression and vulnerability. Therefore, many adipocytokines have been investigated as potential biomarkers of cardiovascular (CV) risk, but their role has not yet been clearly established. Furthermore, the perivascular adipose tissue recently emerged as a critical modulator of atherosclerotic processes, due to the close interaction with the underlying vascular tissue. The ongoing discovery of new adipocytokines and the complex pathophysiological role of the different adipose tissue depots strongly contribute to define the complexity of adipocytokines network. Understanding those complex interactions may allow determining new potential biomarkers of CV risk and potential therapeutic targets.

The effect of adiponectin on osteonectin gene expression by oxidized low density lipoprotein-treated vascular smooth muscle cells

Osteonectin is a bone- associated protein involved in vascular calcification. Adiponectin may protect against cardiovascular disease but possible effects on vascular calcification have been poorly studied. The aim of this study was to investigate the modulatory effect of adiponectin on oxidized low density lipoprotein (oxLDL)- induced expression of osteonectin in human aorta vascular smooth muscle cells (HA/VSMCs). HA/VSMCs were cultured in F12K media and then treated with oxLDL (100 µg/mL) in the presence or absence of adoponectin (5 µg/mL) for 24 and 48 hours. mRNA expression and protein level of osteonectin were determined by quantitative real-time PCR and western blot analysis, respectively. After exposure to oxLDL, osteonectin expression increased 1.62 ± 0.23- and 6.62 ± 0.48-fold after 24 and 48 hours respectively compared to the control. Adiponectin increased oxLDL- induced osteonectin expression in a time-dependent manner after 24 and 48 hours (3.24 ± 0.39- and 24.93 ± 2.15-fold, respectively). Western blotting confirmed that osteonectin protein was upregulated by adiponectin.Our data suggest that OxLDL might cause the increase of osteonectin expression both at mRNA and protein level. This upregulation is intensified by adiponectin.

Association between HMW adiponectin, HMW-total adiponectin ratio and early-onset coronary artery disease in Chinese population

OBJECTIVE

Adiponectin is an adipose-secreting protein that shows atheroprotective property and has inverse relation with coronary artery disease (CAD). High-molecular weight (HMW) adiponectin is reported as the active form of adiponectin. In the present study, we aimed to investigate the association between total adiponectin, HMW adiponectin, HMW-total adiponectin ratio and the severity of coronary atherosclerosis, and to compare their evaluative power for the risk of CAD.

METHODS

Serum levels of total and HMW adiponectin were measured in 382 early-onset CAD (EOCAD) patients and 305 matched controls undergoing coronary angiography by enzyme-linked immunosorbent assay (ELISA). Gensini score was used to evaluate the severity of coronary atherosclerosis.

RESULTS

CAD onset age was positively correlated with HMW adiponectin (r = 0.383, P < 0.001) and HMW-total adiponectin ratio (r = 0.429, P < 0.001) in EOCAD patients. Total and HMW adiponectin and HMW-total adiponectin ratio were all inversely correlated with Gensini score (r = -0.417, r = -0.637, r = -0.578, respectively; all P < 0.001). Multivariate binary logistic regression analysis demonstrated that HMW adiponectin and HMW-total adiponectin ratio were both inversely correlated with the risk of CAD (P < 0.05). ROC analysis indicated that areas under the ROC curves of HMW adiponectin and HMW-total adiponectin ratio were larger than that of total adiponectin (P < 0.05).

CONCLUSIONS

Adiponectin is cardioprotective against coronary atherosclerosis onset in EOCAD patients. HMW adiponectin and HMW-total adiponectin ratio show stronger negative associations with the severity of coronary atherosclerosis than total adiponectin does. HMW adiponectin and HMW-total adiponectin ratio are effective biomarkers for the risk of CAD in Chinese population.