CRIP1 as a sex-specific regulator of metabolic and cardiovascular risk

Introduction Cardiovascular disease (CVD) is one of the leading causes of death worldwide. Metabolic syndrome (MetS) with subacute, low-grade inflammation, obesity, dyslipidemia, hypertension and peripheral insulin resistance or type 2 diabetes mellitus (T2DM) is a major risk factor for many CVD. The incidence of MetS often parallels the incidence of obesity and type 2 diabetes and the prevalence increases with age. In obesity, adipose tissue and immune cells secrete proinflammatory molecules disrupting metabolic regulation. Transcriptome analysis of human monocytes by our group identified CRIP1 as a gene significantly associated with blood pressure. Purpose This study aims to evaluate whether and to what extent CRIP1 influences the risk of developing metabolic syndrome (MetS) and cardiovascular disease (CVD), with a particular focus on sex-specific differences. Methods Monocytic CRIP1 expression and metabolic risk factors were analysed in 1,527 Gutenberg-Health-Study (GHS) participants. In a prediabetic mouse model, white adipose tissue inflammation markers and Crip1 were measured by qPCR. CRIP1 was downregulated in human monocytes via shRNA, followed by pro-inflammatory stimulation; cytokines were assessed by ELISA and qPCR. Bone marrow cells from Crip1-KO mice were differentiated into monocytes to validate human in vitro findings. Crip1-KO mice were treated with Angiotensin II (AngII) for 7 days, PBMCs were isolated, and single-cell RNA sequencing performed. In aged WT and Crip1-KO mice, insulin and glucose were measured by ELISA and glucometer. Results Monocytic CRIP1 expression increased steadily between 30 and 80 years and correlated with age (R² = 0.058; p = 2.31×10⁻²⁰) in 1,527 GHS participants. Furthermore, CRIP1 associated with BMI and HbA1c, but only in male individuals. Mice fed a Western diet for 20 weeks exhibited weight gain, increased white adipose tissue inflammation (Ccl2, Tnf), and elevated Crip1 gene expression, which was observed only in males. CRIP1 downregulation in LPS-stimulated monocytic cell lines reduced NLRP3 inflammasome activation and IL-1B, IL-18, TNF, and IL6 levels. Bone-marrow-derived monocytes from male Crip1-KO mice confirmed these findings. RNA-seq of PBMCs following 7 days of AngII treatment revealed a robust transcriptional response in WT mice, whereas Crip1-KO male mice displayed elevated basal expression of inflammatory genes that were largely downregulated after AngII, indicating a dampened proinflammatory response. In aged mice (70–80 weeks), male Crip1-KO mice weighed less than WT controls, with no differences in insulin or glucose levels. Conclusions CRIP1 potentially regulates age- and sex-dependent inflammation and metabolism, linking it to male susceptibility to metabolic syndrome and CVD, and highlighting it as a potential target for sex-specific therapies.