Panoply™ Human RGMA Knockdown Stable Cell Line

Repulsive guidance molecule a (RGMa) is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein; beyond its role in regulating neuronal differentiation and survival during brain development, it has also been implicated in inflammation-related diseases. However, the specific functions and underlying mechanisms of RGMa in mediating the dedifferentiation of contractile vascular smooth muscle cells (VSMCs) during inflammation-associated atherosclerosis remain unclear. Here, researchers found that VSMC-derived macrophage-like cells express RGMa in the fibrous caps of type V atherosclerotic plaques in ApoE−/− mice and in the neointima following carotid artery ligation. Studies demonstrated that RGMa mRNA and protein levels were elevated in VSMCs exposed to oxidized low-density lipoprotein (ox-LDL). Knockdown of RGMa, both in vivo and in vitro, inhibited ox-LDL-induced VSMC dedifferentiation, proliferation, and migration, and reduced neointimal thickness following left common carotid artery ligation in ApoE−/− mice. Furthermore, the study revealed that RGMa promotes VSMC dedifferentiation by enhancing the activity of the transcription factor Slug; conversely, Slug knockdown reversed the VSMC dedifferentiation induced by RGMa overexpression. Therefore, inhibiting RGMa may serve as a therapeutic strategy for preventing rupture-prone atherosclerotic plaques and vascular restenosis following mechanical injury.

In this study, researchers generated RGMa-knockdown primary rat vascular smooth muscle cells (VSMCs). RGMa knockdown reversed the changes in VSMCs induced by ox-LDL. Western blot analysis showed increased levels of the VSMCs contractile markers, SM22α and α-SMA, and decreased levels of the macrophage-like marker, CD68, in ox-LDL-stimulated RGMa-knockdown VSMCs (Figure 1A–D). Furthermore, scratch assays, Transwell assays, and Cell Counting Kit-8 (CCK-8) assays demonstrated that the proliferation and migration capabilities of ox-LDL-induced RGMa-knockdown VSMCs were reduced (Figure 1E-I). Thus, RGMa knockdown inhibited the proliferation, migration, and dedifferentiation of rat VSMCs under ox-LDL stimulation.

Figure 1. RGMa mediates the dedifferentiation, proliferation, and migration of VSMCs and the neointima formation after arterial injury. (Yuan X, et al., 2022)