Leptin treatment has vasculo-protective effects in lipodystrophic mice.

Lipodystrophy syndromes (LDs) are characterized by loss of adipose tissue, metabolic complications such as dyslipidemia, insulin resistance, and fatty liver disease, as well as accelerated atherosclerosis. As a result of adipose tissue deficiency, the systemic concentration of the adipokine leptin is reduced. A current promising therapeutic option for patients with LD is treatment with recombinant leptin (metreleptin), resulting in reduced risk of mortality. Here, we investigate the effects of leptin on endothelial to mesenchymal transition (EndMT), which impair the functional properties of endothelial cells and promotes atherogenesis in LD. Leptin treatment reduced inflammation and TGF-ß2-induced expression of mesenchymal genes and prevented impairment of endothelial barrier function. Treatment of lipodystrophic- and atherosclerosis-prone animals (Ldlr-/-; aP2-nSrebp1c-Tg) with leptin reduced macrophage accumulation in atherosclerotic lesions, vascular plaque protrusion, and the number of endothelial cells with mesenchymal gene expression, confirming a reduction in EndMT in LD after leptin treatment. Treatment with leptin inhibited LD-mediated induction of the proatherosclerotic cytokine growth/differentiation factor 15 (GDF15). Inhibition of GDF15 reduced EndMT induction triggered by plasma from patients with LD. Our study reveals that in addition to the effects on adipose tissue function, leptin treatment exerts beneficial effects protecting endothelial function and identity in LD by reducing GDF15.

NLRP3 inflammasome-induced pyroptosis and serum ASC specks are increased in patients with cardiogenic shock.

BACKGROUND: Cardiogenic shock (CS) is characterized by impaired cardiac function, very high mortality, and limited treatment options. The pro-inflammatory signalling during different phases of CS is incompletely understood. METHODS: We collected serum and plasma (N=44) as well as freshly isolated peripheral blood mononuclear cells (PBMC, N=7) of patients with CS complicating acute myocardial infarction on admission and after revascularization (24h, 48h, 72h) and of healthy controls (serum and plasma N=75; PBMC N=12). RESULTS: PBMC of CS patients had increased gene expression of NLRP3, CASP1, PYCARD, IL1B, and IL18 and showed increased rates of pyroptosis (control: 4.7±0.3% vs. 9.9±1.7% in CS patients, p=0.02). Serum interleukin (IL)-1ß levels were increased after revascularization. IL-18 and IL-6 were higher in patients with CS than in healthy controls but comparable before and after revascularization. Pro-inflammatory apoptosis-associated speck-like proteins containing CARD (ASC) specks were elevated in the serum of CS patients on admission and increased after revascularization (admission: 11.1±4.4 specks/µl, after 24h: 19.0±3.9, p=0.02). ASC specks showed a significant association with 30-day mortality in patients with CS (p<0.05). The estimated regression coefficients and odds ratios indicated a positive relationship between ASC specks and mortality (Odds ratio 1.029, 95% CI, 1.000 to 1.072; p=0.02). CONCLUSIONS: Pyroptosis and circulating ASC specks are increased in patients with CS and are particularly induced after reperfusion This underscores their potential role as a biomarker for poor outcomes in CS patients. ASC specks represent promising new therapeutic targets for CS patients with high inflammatory burden.