👤 L A Blomberg

The chimeric cytokine IC7Fc conveys the metabolic signaling properties of the glycoprotein 130 receptor cytokines interleukin-6 and ciliary neurotrophic factor via membrane-bound signaling. IC7Fc was previously shown to slow the progression of type 2 diabetes mellitus, and here, we demonstrate its effect on atherosclerotic development. In APOE*3-Leiden.CETP mice, an atherosclerosis-prone model with a humanized lipoprotein metabolism, IC7Fc markedly lowered plasma triglyceride and total cholesterol levels. This was mechanistically explained by an inhibition of de novo lipogenesis in the liver, increased synthesis of bile acids from cholesterol, and down-regulated apolipoprotein B synthesis, which resulted in decreased cholesterol secretion in very low-density lipoprotein particles. As a consequence, IC7Fc treatment considerably reduced atherosclerotic lesion formation and vascular inflammation compared with current antihyperlipidemic therapy. In conclusion, IC7Fc is a promising pharmacological treatment for cardiometabolic diseases targeting hyperlipidemia and inflammation. Show less

LIPC encodes hepatic lipase (HL), a liver-bound protein with both phospholipase and triglyceride lipase activity, and involved in the catabolism of circulating lipoproteins. We recently identified the gain-of-function variant HL-E97G, with selectively increased phospholipase activity, as a new genetic cause of familial combined hypocholesterolaemia in humans. The role of HL in the development of atherosclerosis remains controversial. In this context, the action of HL-E97G on the development of atherosclerosis remains unknown. To evaluate the lipid-lowering and anti-atherogenic properties of HL-E97G vs. wildtype HL (HL-WT) in hypercholesterolaemic APOE*3-Leiden.CETP mice, a well-established model for human-like lipoprotein metabolism, and to assess dependence of these effects on the LDL receptor (LDLR) pathway in LDLR-deficient (Ldlr-/-) mice. APOE*3.Leiden.CETP mice or Ldlr-/- mice received an intravenous injection of AAV8 expressing either eGFP (control), HL-WT or HL-E97G (3 × 1011 GC/mouse) while being fed pro-atherogenic diets. Plasma cholesterol levels were measured monthly, and aortic atherosclerotic lesion sizes were assessed at termination. HL-E97G largely decreased plasma total cholesterol exposure in APOE*3-Leiden.CETP mice (-63% vs. control; -58% vs. HL-WT), resulting at least in part from increased uptake of (V)LDL by the liver, accompanied by a marked decrease in atherosclerotic lesion size (-98% vs. control; -97% vs. HL-WT) in the aortic root. Importantly, HL-E97G also strongly reduced plasma cholesterol exposure in Ldlr-/- mice (-80% vs. control; -77% vs. HL-WT), and decreased atherosclerotic lesion size in the aortic root (-54% vs. control; -41% vs. HL-WT) and the aortic arch (-73% vs. control; -70% vs. HL-WT). HL-E97G strongly reduces plasma cholesterol levels, by increasing the uptake of (V)LDL, to decrease atherosclerosis development in mice independently of the LDLR pathway. These data suggest that modulating HL function is a promising tool in patients with familial hypercholesterolaemia. Show less

Habitual physical activity (PA) affects metabolism and homeostasis in various tissues and organs. However, detailed knowledge of associations between PA and cardiovascular disease (CVD) risk markers is limited. We sought to identify associations between accelerometer-assessed PA classes and 183 proteomic and 154 metabolomic CVD-related biomarkers. We utilized cross-sectional data from the main SCAPIS cohort (n = 4647, median age: 57.5 yrs, 50.5% female) as a discovery sample and the SCAPIS pilot cohort (n = 910, median age: 57.5 yrs, 50.3% female) as a validation sample. PA was assessed via hip-worn accelerometers, while plasma concentrations of proteomic biomarkers were measured using Olink CVD II and III panels. Metabolomic markers were assessed using the Nightingale NMR platform. We evaluated associations between four PA classes (moderate-to-vigorous PA [MVPA], low-intensity PA [LIPA], sedentary [SED], and prolonged SED [prolSED]) and biomarkers, controlling for potential confounders and applying a false discovery rate of 5% using multiple linear regressions. A total of eighty-five metabolomic markers and forty-three proteomic markers were validated and found to be significantly associated with one or more PA classes. LIPA and SED markers demonstrated significant mirroring or opposing relations to biomarkers, while prolSED mainly shared relations with SED. Notably, HDL species were predominantly negatively associated with SED, whereas LDL species were positively associated with SED and negatively associated with MVPA. Among the proteomic markers, eighteen were uniquely associated with MVPA (among those Interleukin - 6 [IL6] and Growth/differentiation factor 15 [GDF15] both negatively related), seven with SED (among those Metalloproteinase inhibitor 4 [TIMP4] and Tumor necrosis factor receptor 2 [TNFR2], both positively related), and eight were related to both SED/prolSED (among those Lipoprotein lipase [LPL] negatively related to SED and leptin [LEP] positively related to SED) and MVPA (with LPL positively related to MVPA and LEP negatively related to MVPA). Our findings suggest the existence of specific associations between PA classes and metabolomic and cardiovascular protein biomarkers in a middle-aged population. Beyond validation of previous results, we identified new associations. This multitude of connections between PA and CVD-related markers may help elucidate the previously observed relationship between PA and CVD. The identified cross-sectional associations could inform the design of future experimental studies, serving as important outcome measures. Show less

Pharmacological blockade of the cannabinoid type 1 receptor, a G protein-coupled receptor expressed in the central nervous system and various peripheral tissues, reverses diet-induced obesity and dyslipidemia through the reduction of food intake and altered nutrient partitioning. This strategy is being explored for a number of therapeutic applications; however, its potency for the treatment of atherosclerotic cardiovascular disease via improvements in lipid metabolism remains unclear. Therefore, here, we aimed to investigate whether inhibition of the endocannabinoid system can attenuate atherosclerosis development through improvement of dyslipidemia. Lean, dyslipidemic female APOE∗3-Leiden.CETP transgenic mice were fed a Western-type diet supplemented with or without the cannabinoid type 1 receptor inverse agonist rimonabant (20 mg·kg body weight Show less

In order to establish the rat testis as a model system for studying the human pregnancy-specific beta1-glycoprotein (PSG), expression and cellular distribution of PSG in rat testis were examined. Three partial PSG cDNAs, namely, rnCGM6, rnGCM7, and rnCGM8 were obtained when rat testis cDNA libraries were screened with a human placental PSG cDNA probe. Unlike the human PSGs, the rat PSGs show less nucleotide and amino acid sequence homology among family members. The rat PSGs also have multiple truncated leader sequences followed by immunoglobulin variable-like N domains while human PSGs have a single N domain. Examination of the testis, intestine, kidney, liver, lung, and muscle of male rats by reverse transcription-polymerase chain reaction (RT-PCR) with nested gene-specific primers showed that rnCGM6 was present only in the testis, while rnCGM8 was present in the testis, intestine and lung. On the other hand rnCMG7 was found in all tissues examined. Furthermore, rnCGM7 transcript was present in all somatic cells examined whereas rnCGM6 was predominantly in myoid cells and rnCMG8 in Leydig cells. These results suggest that there is cell-specificity in the expression of PSGs in the rat testis and that the rat testis is a good model for studying the biological activities of the PSGs. Show less