Long noncoding RNA ACART knockdown decreases 3T3-L1 preadipocyte proliferation and differentiation

Obesity is a main risk factor for diabetes and cardiovascular disorders and is closely linked to preadipocyte differentiation or adipogenesis. Peroxisome proliferator-activated receptor γ (PPARγ) is an indispensable transcription factor in adipogenesis. A newly identified long noncoding RNA, Acart, exerts a protective effect against cardiomyocyte injury by transactivating PPARγ signaling. However, the function of Acart in preadipocyte differentiation is unclear. To investigate the function of Acart in adipogenesis, a well-established preadipocyte, the 3T3-L1 cell line, was induced to differentiate, and Acart level was assessed during differentiation using quantitative real-time PCR. The biological role of Acart in adipogenesis was analyzed by assessing lipid droplet accumulation, PPARγ and CCAAT/enhancer-binding protein α (C/EBPα) expression, and 3T3-L1 cell proliferation and apoptosis after Acart silencing. We found that Acart level was promptly increased during preadipocyte differentiation in vitro. Acart was also significantly upregulated in obese mouse-derived subcutaneous, perirenal, and epididymal fat tissues compared with nonobese mouse-derived adipose tissues. Functionally, Acart depletion inhibited preadipocyte differentiation, as evidenced by a significant decrease in lipid accumulation and PPARγ and C/EBPα expression levels. Acart silencing also inhibited 3T3-L1 cell proliferation, whereas Acart overexpression accelerated 3T3-L1 cell proliferation and decreased cell apoptosis. Taken together, the current results reveal a novel function of Acart in regulating preadipocyte proliferation and differentiation.

Obesity May Not Be a Risk of Non-Target Lesion Revascularization in the Elderly Patients

Obesity is assumed to be one of the robust risk factors for coronary artery disease. However, the effects of obesity on the progression of atherosclerosis in patients in different age groups after percutaneous coronary intervention (PCI) remain unclear. This study aimed to examine the effect of obesity on prognosis in different age groups.Consecutive patients who underwent urgent or elective PCI were surveyed for this study and were then divided into the elderly group and middle-aged group with a cut-off age of 70 years. All patients underwent coronary angiography or coronary computed tomography angiography 1 year after PCI to examine the progression of atherosclerosis. The primary endpoint was revascularization for a new lesion within 2 years after PCI. In addition, the main effects and correlations between obesity and age were examined. Multivariate logistic regression analysis was conducted to identify independent predictors of non-target lesion revascularization (non-TLR).Of the 711 patients who met the criteria and were available for follow-up analysis, the incidence of non-TLR within 2 years was 97/711 (13.6%). The higher incidence of non-TLR in patients with obesity was observed only in the middle-aged group. Furthermore, in the multivariate analysis, obesity was independently associated with non-TLR only in the middle-aged group.The findings of the present study would enable us to construct the hypothesis that obesity in elderly patients may not be an independent predictor of the incidence of non-TLR, indicating that the management to prevent non-TLR may vary depending on the age of the patient.

Obesity Paradox: Laboratory Findings in Uncomplicated Obesity. Is Bias a Plausible Explanation?

OBJECTIVES

Obesity predisposes to multiple diseases, such as heart disease, diabetes, stroke, arthritis, and malignancy. However, obese patients have better outcomes than normal-weight patients with some of these disorders, including those admitted to critical care units. We compared the results for common laboratory tests in patients with uncomplicated obesity against the findings in normal-weight patients.

METHODS

Patients who had a comprehensive metabolic profile test were identified. Patients with acute and/or chronic debilitating disorders were excluded, and the laboratory parameters were compared among 4 groups based on body mass index.

RESULTS

With the exception of elevated triglycerides and lower high-density lipoprotein in obese and morbidly obese patients, laboratory findings were not meaningfully different from those in normal-weight patients.

CONCLUSIONS

The obesity paradox of better outcomes in obese patients admitted to critical care units could not be explained on the basis of lower additional disease burden necessitating critical care admission due to abnormal laboratory values at the baseline. It is conceivable that unconscious bias against obese patients, with lower disease burden than normal-weight patients, triggers their admission to critical care, thus creating the appearance of better outcomes.