Anti-Calponin-1 monoclonal antibody, clone SN373

The vascular smooth muscle cell (VSMC) phenotypic switch is a key pathophysiological change in various cardiovascular diseases, such as aortic dissection (AD), with a high morbidity. Polycystin-1 (PC1) is significantly downregulated in the VSMCs of AD patients. PC1 is an integral membrane glycoprotein and kinase that regulates different biological processes, including cell proliferation, apoptosis, and cell polarity. However, the role of PC1 in intracellular signaling pathways remains poorly understood. In this study, PC1 downregulation in VSMCs promoted the expression of SM22a, ACTA2 and calponin 1 (CNN1) proteins. Furthermore, PC1 downregulation in VSMCs upregulated phospho-MEK, phospho-ERK and myc, but did not change phospho-JNK and phospho-p38. These findings suggest that the MEK/ERK/myc signaling pathway is involved in PC1-mediated human VSMC phenotypic switch. Opposite results were observed when an ERK inhibitor was used in VSMCs downregulated by PC1. When the C-terminal domain of PC1 (PC1 C-tail) was overexpressed in VSMCs, the expression levels of phosphor-ERK, myc, SM22a, ACTA2 and CNN1 proteins were downregulated. The group with the overexpressed mutant protein (S4166A) in the PC1 Ctail showed similar results to the group with the downregulated PC1 in VSMCs. These results suggest that the Ser at the 4166 site in PC1 is crucial in the PC1 mediated MEK/ERK/myc signaling pathway, which might be the key pathophysiological cause of AD.

Vascular smooth muscle cells (VSMCs) are major component of the vascular wall, and they play an essential role in maintaining the basic physiological function and stable structure of the Vascular wall. In the present study, human gingival fibroblasts (HGFs) were cultured and induced into VSMC-like cells in vitro to confirm that HGFs with properties of stem cells have the potential for differentiation. The epithelium isolated from patients was extracted from normal human gingiva consisting of epithelium and connective tissue. HGFs were first identified by morphological examination, as well as specific gene and protein expression, and then induced by 10 ng/mL PDGF-BB combined with 2 ng/mL of TGF-beta 1 for 28 days. After induction, ICS data indicated that induced VSMC-like cells were positive for alpha-SMA and SM-MHC, and IFA data showed that induced cells were positive for SM22 alpha and Cnn1. RT-PCR results demonstrated that alpha-SMA and SM-MHC mRNA were specifically expressed, and myofilament-like structures also appeared in induced cells. In conclusion, the data indicated that HGFs could differentiate to VSMC-like cells with typical VSMC morphologic, ultrastructural, and immunological characteristics via induction with PDGF-BB and TGF-beta 1.