| First Author | Gupta S | Year | 2022 |
| Journal | Front Cardiovasc Med | Volume | 9 |
| Pages | 1020006 | PubMed ID | 36505365 |
| Mgi Jnum | J:334302 | Mgi Id | MGI:7409159 |
| Doi | 10.3389/fcvm.2022.1020006 | Citation | Gupta S, et al. (2022) Sex-specific differences in atherosclerosis, thrombospondin-1, and smooth muscle cell differentiation in metabolic syndrome versus non-metabolic syndrome mice. Front Cardiovasc Med 9:1020006 |
| abstractText | INTRODUCTION: Metabolic syndrome (MetS) amplifies the risks of atherosclerosis. Despite well-known sexual dimorphism in atherosclerosis, underlying mechanisms are poorly understood. Our previous findings highlight a proatherogenic protein, thrombospondin-1 (TSP-1), in hyperglycemia- or hyperleptinemia (mimicking obesity)-induced atherosclerosis. However, the role of TSP-1 in the development of atherosclerosis prompted by co-existing hyperglycemia and obesity, characteristic of MetS, is unknown. The goal of this study was to examine sex-specific differences in lesion progression in a model of combined MetS and atherosclerosis (KKAyApoE) and interrogate how these differences relate to TSP-1 expression. METHODS: Male and female KKAy(+/-)ApoE(-/-) (with ectopic agouti gene expression) and age-matched non-agouti KKAy(-/-)ApoE(-/-) littermates were placed on a standard laboratory diet from 4 to 24 weeks age followed by blood and tissue harvests for biochemical, molecular, and aortic root morphometric studies. RESULTS: Metabolic profiling confirmed MetS phenotype of KKAy(+/-)ApoE(-/-); however, only male genotypes were glucose intolerant with elevated VLDL-cholesterol and VLDL-triglyceride levels. Aortic root morphometry demonstrated profound lipid-filled lesions, increased plaque area, and augmented inflammatory and SMC abundance in MetS vs non-MetS males. This increase in lesion burden was accompanied with elevated TSP-1 and attenuated LMOD-1 (SM contractile marker) and SRF (transcriptional activator of SM differentiation) expression in male MetS aortic vessels. In contrast, while lipid burden, plaque area, and TSP-1 expression increased in MetS and non-MetS female mice, there was no significant difference between these genotypes. Increased collagen content was noted in MetS and non-MetS genotypes, specific to female mice. Measurement of plasma testosterone revealed a link between the atherogenic phenotype and abnormally high or low testosterone levels. To interrogate whether TSP-1 plays a direct role in SMC de-differentiation in MetS, we generated KKAy(+/-) mice with and without global TSP-1 deletion. Immunoblotting showed increased SM contractile markers in male KKAy(+/-)TSP-1(-/-) aortic vessels vs male KKAy(+/-)TSP-1(+/ +). In contrast, TSP-1 deletion had no effect on SM contractile marker expression in female genotypes. CONCLUSION: Together, the current study implicates a role of plasma testosterone in sex-specific differences in atherosclerosis and TSP-1 expression in MetS vs non-MetS mice. Our data suggest a sex-dependent differential role of TSP-1 on SMC de-differentiation in MetS. Collectively, these findings underscore a fundamental link between TSP-1 and VSMC phenotypic transformation in MetS. |
