Nicotine Impairs the Anti-Contractile Function of Perivascular Adipose Tissue by Inhibiting the PPARγ-Adiponectin-AdipoR1 Axis

Cigarette smoke extract decreases human bone marrow mesenchymal stromal cell adipogenic differentiation

BACKGROUND

Smoking and nicotine impose detrimental health effects including adipose tissue dysfunction. Despite extensive physiological evidence, the cellular mechanisms remain poorly understood, with few studies examining the effects of cigarette smoke extract (CSE) or nicotine on adipocyte differentiation.

METHODS

Primary human bone marrow-derived mesenchymal stromal cells (MSCs) were exposed to CSE or nicotine (50-500 ng/ml) during adipogenic differentiation. Cell viability and metabolic activity were assessed via MTT assay. Lipid droplet accumulation was evaluated using Sudan III staining and quantitative image analysis. Adiponectin, IL6, and IL8 concentrations were measured after 35 days using ELISA.

RESULTS

At these doses, CSE and nicotine do not immediately affect cell viability but inhibit undifferentiated cell proliferation. Notably, both agents at 50 ng/ml significantly increased lipid accumulation during adipogenesis, while higher CSE doses nearly completely inhibited this process. Additionally, CSE dose-dependently decreased adiponectin secretion and increased IL6 and IL8, indicating a shift towards an inflammatory state. Nicotine alone primarily increased IL6 secretion with less pronounced effects.

CONCLUSION

The study highlights the complex impact of CSE and nicotine on adipocyte function during early differentiation from MSCs. Dose-dependent changes in lipid accumulation, cytokine, and adiponectin secretion induced by CSE and nicotine can partly explain smoking-related adipose tissue dysfunction.

Persicaria minor (Huds.) Opiz Exhibits Antihypertensive Effects by Inhibiting the Angiotensin-Converting Enzyme/Angiotensin II Type 1 Receptor Pathway in Human Endothelial Cells

Overactivation of the angiotensin-converting enzyme (ACE)/angiotensin II type 1 receptor (AT1R) pathway leads to vasoconstriction and elevated blood pressure. Persicaria minor (Huds.) Opiz is an herbal plant known for its antioxidant, anti-hyperlipidemic, and anti-atherosclerotic properties, with bioactive compounds that exhibit antihypertensive effects. Therefore, this study aimed to evaluate the antihypertensive effects of the standardized aqueous extract of P. minor leaf (AEPM) through the ACE/AT1R pathway in human umbilical vein endothelial cells (HUVECs) induced with phorbol 12-myristate 13-acetate (PMA). HUVECs were stimulated with PMA to induce ACE, with or without AEPM or captopril treatment, for 24 h. Subsequently, ACE mRNA expression, ACE protein levels, ACE activity, angiotensin II levels, and AT1R expression were measured. The results demonstrated that AEPM treatment significantly reduced ACE mRNA expression, ACE protein levels, ACE activity, angiotensin II levels, and AT1R expression in PMA-induced HUVECs. The modulatory effects of AEPM on the ACE/AT1R pathway were comparable to those of captopril. Ex vivo experiments further confirmed that AEPM reduced the contraction responses of rat aortic rings to PMA. In conclusion, P. minor effectively inhibits the ACE/AT1R pathway in PMA-induced HUVECs, suggesting its potential as a natural antihypertensive agent.

Piper sarmentosum Roxb. Inhibits Angiotensin-Converting Enzyme Activity in Phorbol 12-Myristate-13-Acetate-Induced Endothelial Cells

Angiotensin-converting enzyme (ACE) plays a crucial role in the pathogenesis of hypertension. Piper sarmentosum Roxb., an herb known for its antihypertensive effect, lacks a comprehensive understanding of the mechanism underlying its antihypertensive action. This study aimed to elucidate the antihypertensive mechanism of aqueous extract of P. sarmentosum leaves (AEPS) via its modulation of the ACE pathway in phorbol 12-myristate-13-acetate (PMA)-induced human umbilical vein endothelial cells (HUVECs). HUVECs were divided into five groups: control, treatment with 200 µg/mL AEPS, induction 200 nM PMA, concomitant treatment with 200 nM PMA and 200 µg/mL AEPS, and treatment with 200 nM PMA and 0.06 μM captopril. Subsequently, ACE mRNA expression, protein level and activity, angiotensin II (Ang II) levels, and angiotensin II type 1 receptor (AT1R) and angiotensin II type 2 receptor (AT2R) mRNA expression in HUVECs were determined. AEPS successfully inhibited ACE mRNA expression, protein and activity, and angiotensin II levels in PMA-induced HUVECs. Additionally, AT1R expression was downregulated, whereas AT2R expression was upregulated. In conclusion, AEPS reduces the levels of ACE mRNA, protein and activity, Ang II, and AT1R expression in PMA-induced HUVECs. Thus, AEPS has the potential to be developed as an ACE inhibitor in the future.