Tiaozhi Tongmai Formula attenuates atherosclerosis by modulating the JAK1/STAT3 pathway to inhibit phenotypic transformation of vascular smooth muscle cells.

Abstract

Background: Atherosclerosis (AS) progression is closely associated with phenotypic transformation of vascular smooth muscle cells (VSMCs) and activation of the Janus kinase 1/signal transducer and activator of transcription 3 (JAK1/STAT3) signaling pathway. This study aimed to elucidate the active components and underlying mechanisms of the Tiaozhi Tongmai Formula (TZTMF) in ameliorating AS through both in vivo and in vitro experiments.

Methods: The chemical constituents and serum pharmacochemistry of TZTMF were characterized using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. An AS model was established in apolipoprotein E-deficient mice fed with a high-fat diet. The therapeutic effects of TZTMF were evaluated using hematoxylin and eosin, Movat pentachrome, and immunohistochemical staining, as well as western blot analysis. In hypoxia-stimulated mouse VSMCs, enzyme-linked immunosorbent assay, Transwell migration, wound-healing, immunofluorescence, western blot, and reverse transcription-quantitative polymerase chain reaction assays were conducted to assess cell viability and cellular responses to TZTMF.

Results: A total of seventy-eight compounds were identified in TZTMF, of which thirty-nine were detected in serum. In vivo, TZTMF reduced AS progression, promoted plaque stabilization, and attenuated inflammation, abnormal proliferation, and phenotypic transformation of smooth muscle cells (SMCs) through downregulation of the JAK1/STAT3 signaling pathway. In vitro, TZTMF-containing serum suppressed hypoxia-induced SMC proliferation and migration, prevented the transition from the contractile to the synthetic phenotype, and decreased JAK1 and STAT3 expression at both the messenger RNA (mRNA) and protein levels. Furthermore, the regulatory effects of TZTMF on mouse aortic vascular smooth muscle (MOVAS) cells were largely mediated through the JAK1 pathway.

Conclusions: TZTMF exerts anti-atherosclerotic effects in both in vivo and in vitro models. It contributes to plaque stabilization by enhancing collagen deposition, reducing inflammation, and suppressing SMC proliferation and phenotypic transformation, primarily through inhibition of the JAK1/STAT3 signaling pathway.