Immunity, inflammation and disease
Interleukin-35 Ameliorates Obesity-Associated Impairment of Endothelium-Dependent Vasodilation via the STAT3-MAPK/ERK-eNOS Signaling Axis
By Li K, Feng J, Gong R and 2 others.
Abstract
Background
Obesity impairs endothelial nitric oxide synthase (eNOS)-nitric oxide (NO) signaling, triggering chronic inflammation, endothelial dysfunction and defective vasodilation, which drives cardiometabolic diseases. Existing metabolic therapies provide only indirect vascular protection and fail to resolve residual inflammatory-mediated cardiovascular risk. As an anti-inflammatory interleukin 12 (IL-12) family cytokine, interleukin 35 (IL-35) is suppressed in obesity and exerts vascular protective effects under inflammatory conditions, yet its function and underlying mechanisms in obesity‑related endothelial vasodilator dysfunction remain undefined.
Materials and methods
An obese mouse model was established by 8-week high-fat diet (HFD) feeding, followed by 4-week intraperitoneal administration of recombinant mouse IL-35. Aortic-ring assays evaluated vasodilatory function. Palmitic acid (PA)-treated human umbilical vein endothelial cells (HUVECs), recapitulate lipotoxic endothelial injury, were treated with recombinant human IL-35. Western blotting, immunofluorescence, 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM DA) detection and immunoprecipitation-mass spectrometry (IP-MS) were applied to detect IL-35-subunit (Epstein-Barr virus-induced gene 3 [EBI3] and interleukin-12 subunit alpha [IL-12A]) levels, eNOS Ser1177 phosphorylation, phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling molecules (cellular rapidly accelerated fibrosarcoma [cRAF], mitogen-activated protein kinase kinase [MEK], and ERK) and signal transducer and activator of transcription 3 (STAT3) activation, NO production, and eNOS-binding partners. Rescue assays were performed using Raf or ERK specific inhibitors and STAT3 small interfering RNA (siRNA).