👤 Stephan Sachs

Lower-extremity arterial disease (LEAD) is a manifestation of atherosclerotic cardiovascular disease, affecting 230 million people worldwide with increasing prevalence. Medial arterial calcification (MAC) is common in LEAD patients and contributes to disease-related mortality. However, therapeutic strategies targeting femoral MAC are lacking, and its underlying mechanisms remain unclear. This study aimed to identify molecular drivers of femoral MAC in LEAD. Calcium deposits and pro-calcifying markers were analyzed in human patient samples using von Kossa staining, immunofluorescence, and gene expression analysis. Femorals showed significantly more calcification and pro-calcifying gene expression than carotids. Given MAC abundance in LEAD, we assessed medial calcification in Apoe-/- mice fed a WD for 4/21 weeks. Digital PCR revealed upregulation of Ddr1 and Bmp2 in femoral versus carotid arteries after 21 weeks of WD. DDR1 expression positively correlated with calcification in human femoral samples. In vitro experiments with mouse femoral vs. carotid vascular smooth muscle cells (VSMCs) confirmed a significantly higher prevalence of calcifying proteins (DDR1, BMP2, and RUNX2) in femoral VSMCs. Additionally, calcification analyses in murine and human VSMCs showed that DDR1 inhibition reduced, while DDR1 activation increased, calcium deposition. Transcriptomic analysis revealed elevated NF-κB expression in human femoral arteries, matching data in femoral VSMCs. DDR1 stimulation activated NF-κB, and its inhibition blocked DDR1-induced calcification. This study identifies DDR1 as a key driver of calcification in LEAD, operating through NF-κB activation and the expression of calcifying proteins. Targeting DDR1 may offer a novel therapeutic approach to prevent MAC in LEAD. Show less

Agonism at the receptor for the glucose-dependent insulinotropic polypeptide (GIPR) is a key component of the novel unimolecular GIPR:GLP-1R co-agonists, which are among the most promising drugs in clinical development for the treatment of obesity and type 2 diabetes. The therapeutic effect of chronic GIPR agonism to treat dyslipidemia and thus to reduce the cardiovascular disease risk independently of body weight loss has not been explored yet. After 8 weeks on western diet, LDL receptor knockout (LDLR-/-) male mice were treated with daily subcutaneous injections of long-acting acylated GIP analog (acyl-GIP; 10nmol/kg body weight) for 28 days. Body weight, food intake, whole-body composition were monitored throughout the study. Fasting blood glucose and intraperitoneal glucose tolerance test (ipGTT) were determined on day 21 of the study. Circulating lipid levels, lipoprotein profiles and atherosclerotic lesion size was assessed at the end of the study. Acyl-GIP effects on fat depots were determined by histology and transcriptomics. Herein we found that treatment with acyl-GIP reduced dyslipidemia and atherogenesis in male LDLR-/- mice. Acyl-GIP administration resulted in smaller adipocytes within the inguinal fat depot and RNAseq analysis of the latter revealed that acyl-GIP may improve dyslipidemia by directly modulating lipid metabolism in this fat depot. This study identified an unanticipated efficacy of chronic GIPR agonism to improve dyslipidemia and cardiovascular disease independently of body weight loss, indicating that treatment with acyl-GIP may be a novel approach to alleviate cardiometabolic disease. Show less

Unimolecular peptides targeting the receptors for glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) (GLP-1/GIP co-agonist) have been shown to outperform each single peptide in the treatment of obesity and cardiometabolic disease in preclinical and clinical trials. By combining physiological treatment endpoints with plasma proteomic profiling (PPP), we aimed to identify biomarkers to advance non-invasive metabolic monitoring of compound treatment success and exploration of ulterior treatment effects on an individual basis. We performed metabolic phenotyping along with PPP in body weight-matched male and female diet-induced obese (DIO) mice treated for 21 days with phosphate-buffered saline, single GIP and GLP-1 mono-agonists, or a GLP-1/GIP co-agonist. GLP-1R/GIPR co-agonism improved obesity, glucose intolerance, non-alcoholic fatty liver disease (NAFLD) and dyslipidaemia with superior efficacy in both male and female mice compared with mono-agonist treatments. PPP revealed broader changes of plasma proteins after GLP-1/GIP co-agonist compared with mono-agonist treatments in both sexes, including established and potential novel biomarkers for systemic inflammation, NAFLD and atherosclerosis. Subtle sex-specific differences have been observed in metabolic phenotyping and PPP. We herein show that a recently developed unimolecular GLP-1/GIP co-agonist is more efficient in improving metabolic disease than either mono-agonist in both sexes. PPP led to the identification of a sex-independent protein panel with the potential to monitor non-invasively the treatment efficacies on metabolic function of this clinically advancing GLP-1/GIP co-agonist. Show less

Pharmacological stimulation of brown adipose tissue (BAT) thermogenesis to increase energy expenditure is progressively being pursued as a viable anti-obesity strategy. Here, we report that pharmacological activation of the cold receptor transient receptor potential cation channel subfamily M member 8 (TRPM8) with agonist icilin mimics the metabolic benefits of cold exposure. In diet-induced obese (DIO) mice, treatment with icilin enhances energy expenditure, and decreases body weight, without affecting food intake. To further potentiate the thermogenic action profile of icilin and add complementary anorexigenic mechanisms, we set out to identify pharmacological partners next to icilin. To that end, we specifically targeted nicotinic acetylcholine receptor (nAChR) subtype alpha3beta4 (α3β4), which we had recognized as a potential regulator of energy homeostasis and glucose metabolism. Combinatorial targeting of TRPM8 and nAChR α3β4 by icilin and dimethylphenylpiperazinium (DMPP) orchestrates synergistic anorexic and thermogenic pathways to reverse diet-induced obesity, dyslipidemia, and glucose intolerance in DIO mice. Show less