Dysregulated lipolysis and lipophagy in lipid droplets of macrophages from high fat diet-fed obese mice.

Obesity is associated with lipid droplet (LD) accumulation, dysregulated lipolysis and chronic inflammation. Previously, the caspase recruitment domain-containing protein 9 (CARD9) has been identified as a potential contributor to obesity-associated abnormalities including cardiac dysfunction. In the current study, we explored a positive feedback signalling cycle of dysregulated lipolysis, CARD9-associated inflammation, impaired lipophagy and excessive LD accumulation in sustaining the chronic inflammation associated with obesity. C57BL/6 WT and CARD9-/- mice were fed with normal diet (ND, 12% fat) or a high fat diet (HFD, 45% fat) for 5 months. Staining of LDs from peritoneal macrophages (PMs) revealed a significant increase in the number of cells with LD and the number of LD per cell in the HFD-fed WT but not CARD9-/- obese mice. Rather, CARD9 KO significantly increased the mean LD size. WT obese mice showed down regulation of lipolytic proteins with increased diacylglycerol (DAG) content, and CARD9 KO normalized DAG with restored lipolytic protein expression. The build-up of DAG in the WT obese mice is further associated with activation of PKCδ, NF-κB and p38 MAPK inflammatory signalling in a CARDD9-dependent manner. Inhibition of adipose triglyceride lipase (ATGL) by Atglistatin (Atg) resulted in similar effects as in CARD9-/- mice. Interestingly, CARD9 KO and Atg treatment enhanced lipophagy. In conclusion, HFD feeding likely initiated a positive feedback signalling loop from dysregulated lipolysis, CARD9-dependent inflammation, impaired lipophagy, to excessive LD accumulation and sustained inflammation. CARD9 KO and Atg treatment protected against the chronic inflammation by interrupting this feedforward cycle.

E-cigarette exposure with or without heating the e-liquid induces differential remodeling in the lungs and right heart of mice.

Various cardiopulmonary pathologies associated with electronic cigarette (EC) vaping have been reported. This study investigated the differential adverse effects of heating-associated by-products versus the intact components of EC aerosol to the lungs and heart of mice. We further dissected the roles of caspase recruitment domain-containing protein 9 (CARD9)-associated innate immune response and NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in EC exposure-induced cardiopulmonary injury. C57BL/6 wild type (WT), CARD9-/-, and NLRP3-/- mice were exposed to EC aerosol 3 h/day, 5 days/week for 6 month with or without heating the e-liquid with exposure to ambient air as the control. In WT mice, EC exposure with heating (EwH) significantly increased right ventricle (RV) free wall thickness at systole and diastole. However, EC exposure without heating (EwoH) caused a significant decrease in the wall thickness at systole. RV fractional shortening was also markedly reduced following EwH in WT and NLRP3-/- mice. Further, EwH activated NF-κB and p38 MAPK inflammatory signaling in the lungs, but not in the RV, in a CARD9- and NLRP3-dependent manner. Levels of circulatory inflammatory mediators were also elevated following EwH, indicating systemic inflammation. Moreover, EwoH activated TGF-ß1/SMAD2/3/α-SMA fibrosis signaling in the lungs but not the RV of WT mice. In conclusion, EC aerosol exposure following EwH or EwoH induced differential cardiopulmonary remodeling and CARD9 innate immune response and NLRP3 inflammasome contributed to the adverse effects.

A potential role of caspase recruitment domain family member 9 (Card9) in transverse aortic constriction-induced cardiac dysfunction, fibrosis, and hypertrophy.

Macrophage- and monocyte-derived cytokines are elevated in the myocardium of pressure-overloaded hearts, where they play critical roles in pathological remodeling. Caspase recruitment domain family member 9 (CARD9) regulates macrophage cytokine secretion, but its role in a transverse aortic constriction (TAC) model of pressure overload has not been evaluated. To investigate whether CARD9 may serve as a valuable therapeutic target, wild-type (WT) and CARD9-knockout mice were subjected to 3 months of TAC, and then cardiac function, hypertrophy, and fibrosis were analyzed. The expression of protein markers of myocardial autophagy and nuclear factor kappa B signaling was also investigated. At 1 month after TAC, cardiomyocyte contractile dynamics were measured in a separate cohort to further assess contractility and diastolic function. In WT but not CARD9-/- mice, TAC resulted in severe cardiomyocyte contractile dysfunction at 1 month and functional decrements in fractional shortening at 3 months in vivo. Furthermore, CARD9-/- mice did not develop cardiac fibrosis or hypertrophy. CARD9-/- mice also had decreased protein expression of inhibitor of κB kinase-α/ß, decreased phosphorylation of p65, and increased expression of protein markers of autophagy. These findings suggest that CARD9 plays a role in pathological remodeling and cardiac dysfunction in mouse hearts subjected to TAC and should be investigated further.

Antihypertensive activity of 80% methanol seed extract of Calpurnia aurea (Ait.) Benth. subsp. aurea (Fabaceae) is mediated through calcium antagonism induced vasodilation.

ETHNOPHARMACOLOGICAL RELEVANCE: Calpurnia aurea (Ait.) Benth. subsp. aurea (CASA) (Fabaceae) seeds are used to treat hypertension in Ethiopian folklore medicine, particularly by Shinasha, Agew-awi and Amhara people in northwest Ethiopia. However, the claim has so far not been substantiated scientifically. AIM OF THE STUDY: The study was conducted to evaluate the antihypertensive activity of 80% methanol extract of CASA in animal model of hypertension as well as its vasorelaxant effect and possible underlying mechanisms in isolated guinea pig aorta. MATERIAL AND METHODS: Hypotensive and antihypertensive effect of CASA extract was determined in vivo through the intravenous (iv) route in normotensive and hypertensive anesthetized rats using 2-kidney-1-clip (2K1C) rat model. Ex vivo, guinea pig thoracic aortic rings were isolated and suspended in organ bath, and the vasodepressor effects as well as the mechanism of action of the extract were studied by means of isometric tension recording experiments. RESULTS: The blood pressure fell dose-dependently and significantly in renal hypertensive and normotensive rats following i.v. administration, suggesting that the hydroalcoholic extract possesses hypotensive and antihypertensive effects. The extract also caused a dose-dependent relaxation of aorta pre-contracted with KCl at a concentration of 5-250mg/L, with a maximum relaxation of 92.1% achieved at 250mg/L. The relaxation mechanism was found to be independent of the muscarinic receptors, histamine receptors, ATP dependent K(+) channels, cyclooxygenase enzymes, cGMP/NO pathway and the endothelium system. The extract caused rightward shift of the Ca(++) dose-response curves, similar to that caused by verapamil, indicating that it produced vasorelaxation by inhibiting extracellular Ca(2+) influx. CONCLUSIONS: The findings demonstrate that the plant is endowed with antihypertensive effect, providing evidence for its traditional use. The effect may be, at least in part, due to dilation of blood vessels through blockage of Ca(2+) channels.