RESUMO
Vascular smooth muscle cell (VSMC) apoptosis is a major defining feature of abdominal aortic aneurysm (AAA) and mainly caused by inflammatory cell infiltration. Smooth muscle (SM) 22α prevents AAA formation through suppressing NF-κB activation. However, the role of SM22α in VSMC apoptosis is controversial. Here, we identified that SM22α loss contributed to apoptosis of VSMCs via activation of macrophages. Firstly, deficiency of SM22α enhanced the interaction of VSMCs with macrophages. Macrophages were retained and activated by Sm22α -/- VSMCs via upregulating VCAM-1 expression. The ratio of apoptosis was increased by 1.62-fold in VSMCs treated with the conditional media (CM) from activated RAW264.7 cells, compared to that of the control CM (P < 0.01), and apoptosis of Sm22α -/- VSMCs was higher than that of WT VSMCs (P < 0.001). Next, circRasGEF1B from activated macrophages was delivered into VSMCs promoting ZFP36 expression via stabilization of ZFP36 mRNA. Importantly, circRasGEF1B, as a scaffold, guided ZFP36 to preferentially bind to and decay Bcl-2 mRNA in a sequence-specific manner and triggered apoptosis of VSMCs, especially in Sm22α -/- VSMCs. These findings reveal a novel mechanism by which the circRasGEF1B-ZFP36 axis mediates macrophage-induced VSMC apoptosis via decay of Bcl-2 mRNA, whereas Sm22α -/- VSMCs have a higher sensitivity to apoptosis.
Assuntos
Macrófagos/citologia , Macrófagos/metabolismo , Proteínas dos Microfilamentos/deficiência , Proteínas Musculares/deficiência , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , RNA Circular/metabolismo , Animais , Apoptose/fisiologia , Comunicação Celular/fisiologia , Técnicas de Reprogramação Celular , Humanos , Masculino , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Células RAW 264.7 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Tristetraprolina/biossíntese , Tristetraprolina/genética , Tristetraprolina/metabolismoRESUMO
AIM: To investigate the abundance and potential diagnostic significance of neuroligin-1 and glutamate (Glu) in Hirschsprung's disease (HSCR). METHODS: Ninety children with HSCR and 50 children without HSCR matched for similar nutritional status, age and basal metabolic index were studied. The expression and localization of neuroligin-1 and Glu were assessed using double-labeling immunofluorescence staining of longitudinal muscles with adherent myenteric plexus from the surgically excised colon of children with HSCR. Western blot analysis, quantitative real-time PCR (qRT-PCR) and immunohistochemistry were performed to evaluate the abundance of neuroligin-1 and Glu in different HSCR-affected segments (ganglionic, transitional, and aganglionic segments). Enzyme-linked immunosorbent assay (ELISA) was used to detect and compare serum Glu levels in the long-segment HSCR, short-segment HSCR and non-HSCR samples. RESULTS: Neuroligin-1 and Glu were co-expressed highest to lowest in the ganglionic, transitional and aganglionic segments based on Western blot (neuroligin-1: 0.177 ± 0.008 vs 0.101 ± 0.006, 0.177 ± 0.008 vs 0.035 ± 0.005, and 0.101 ± 0.006 vs 0.035 ± 0.005, P < 0.005; Glu: 0.198 ± 0.006 vs 0.115 ± 0.008, 0.198 ± 0.006 vs 0.040 ± 0.003, and 0.115 ± 0.008 vs 0.040 ± 0.003, P < 0.005) and qRT-PCR (neuroligin-1: 9.58 × 10(-5) ± 9.94 × 10(-6) vs 2.49 × 10(-5) ± 1.38 × 10(-6), 9.58 × 10(-5) ± 9.94 × 10(-6) vs 7.17 × 10(-6 ±) 1.12 × 10(-6), and 2.49 × 10(-5) ± 1.38 × 10(-6) vs 7.17 × 10(-6) ± 1.12 × 10(-6), P < 0.005). Serum Glu level was the highest to lowest in the non-HSCR, short-type HSCR and long-type HSCR samples based on ELISA (in nmol/µL, 0.93 ± 0.31 vs 0.57 ± 0.25, 0.93 ± 0.31 vs 0.23 ± 0.16, and 0.57 ± 0.25 vs 0.23 ± 0.16, P < 0.005). CONCLUSION: Neuroligin-1 and Glu may represent new markers of ganglion cells, whose expression may correlate with the pathogenesis, diagnosis, differential diagnosis or classification of HSCR.
