GLP-1R Nuclear Export Promotes the Proliferation and Migration of Vascular Smooth Muscle Cells via the C14orf166-GSK3β Signaling Axis
FAN Shaohua1, SHI Yawei2*
The cardiovascular protective effects of GLP-1R (glucagon-like peptide-1 receptor) have been documented, and most studies have focused on canonical cell-membrane signaling pathways mediated by GLP-1R. The previous study revealed that GLP-1R exhibited a non-classical nuclear localization, and AngII (angiotensin II) induced its nuclear export. However, the molecular mechanism by which GLP-1R regulates the abnormal proliferation and migration of VSMCs (vascular smooth muscle cells) remains unclear. This study aimed to explore the molecular mechanism underlying the proliferation and migration of RASMCs (rat thoracic aortic smooth muscle cells) mediated by GLP-1R nuclear export. Cell proliferation, cell migration, as well as the expression levels of cyclin D1 and PCNA, were detected by MTT assay, wound healing assay and Western blot. Immunofluorescence staining was used to observe the subcellular localization of GLP-1R, and co-immunoprecipitation was applied to verify protein-protein interactions. Bioinformatics analysis and yeast two-hybrid assay confirmed the nuclear interaction between GLP-1R and C14orf166. To further clarify their intranuclear functions, an AngII-induced injury model of RASMCs was established. The results showed that under resting conditions, GLP-1R binded to C14orf166 in the nucleus, and inhibited its transcriptional activity. Upon AngII stimulation, GLP-1R undergone nuclear export, leading to its dissociation from C14orf166. The dissociated free C14orf166 inhibits the activity of GSK3β (glycogen synthase kinase 3β), consequently activating the signaling pathways that promote proliferation and migration of RASMCs, and ultimately mediating pathological vascular remodeling. In conclusion, this study elucidates a novel molecular mechanism of vascular remodeling mediated by GLP-1R nuclear export: GLP-1R nuclear export-activating the transcription of C14orf166-inhibition of GSK3β activity-promoting RASMCs proliferation and migration-vascular remodeling. These finding expands the functional scope of GLP-1R, provides new perspectives for understanding the cardiovascular protective effects of GLP-1R.
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