👤 Albert Beckers

We investigated the relationship between heart failure etiology and lipoprotein subfractions, and to explore their associations with left ventricular dimension and function in heart failure with reduced ejection fraction (HFrEF) patients. Cross-sectional investigation of serum lipoprotein subfractions from 205 HFrEF patients in the SMARTEX heart failure study. Serum levels of triglycerides, cholesterol, free cholesterol, phospholipids, lipoproteins (Apolipoproteins; A-1, A-2, and B), very-low-density (VLDL), intermediate-density (IDL), low-density (LDL), and high-density lipoprotein (HDL) were determined using Stable HFrEF patients [left ventricular ejection fraction (LVEF) ≤ 35%, NYHA class II-III], with ischemic (ICM, n = 119) or non-ischemic (NICM, n = 86) cardiomyopathy were studied. NICM patients had higher levels of 48 lipoproteins compared to ICM patients, including 29 LDL, 13 VLDL, and 6 HDL subfractions [p <0.05]. NICM patients had 22% higher cholesterol and 27% higher remnant cholesterol levels, with 24% more atherogenic ApoB containing subfractions (VLDL, IDL, LDL) (p <0.05). Heart failure etiology and statin treatment explained 23-24% of the variability in cholesterol, free cholesterol, and ApoB (p <0.001). Triglyceride content in some VLDL and LDL subfractions was weakly associated with left ventricular end-diastolic volume, end-diastolic diameter, ejection fraction, and S'. NICM patients had the highest atherosclerotic lipoprotein burden, attributed to elevated ApoB particles and partly due to less statin treatment. The triglyceride content of some VLDL and LDL subfractions was weakly associated with left ventricular structure and function. However, further research is needed to determine their prognostic significance before implementation into strategies for prevention and treatment. Show less

Mutations in BMP4 have been associated with malformations of the urinary tract in human patients. Genetic studies in mice have shown that these defects are linked to the expression of Bmp4 in the mesenchymal primordium of the ureter, where it acts as a critical signal for coordinated cytodifferentiation of the mesenchymal and epithelial tissues. Here, we used unbiased transcriptional profiling of ureters with genetic depletion of Bmp4 and pharmacological inhibition of BMP4 signaling to decipher the gene regulatory network controlled by BMP4 in the early ureter, focusing on transcription factors as possible drivers of cytodifferentiation. We show that in Bmp4-deficient ureters, expression of Grhl3, Msx2, Pparg, Trp63 and Foxa1 in the epithelial compartment, and of Gata6, Hopx, Id2, Id4, Myocd, Snai1 and Tbx18 in the mesenchymal primordium is reduced. Expression of Msx2, Pparg, Gata6, Id genes, Tbx18 and Snai1 requires direct BMP4 signaling input, whereas reduced expression of the other genes is likely due to secondary changes, including increased retinoic acid signaling. Conditional gene targeting of Smad4 revealed that BMP4-dependent activation of transcription factor genes is mediated in part by SMAD effectors in both ureteral tissues. Thus, our work links BMP4 (signaling) to known transcriptional regulators of ureteral cytodifferentiation and uncovers additional factors that may be relevant to this program. Show less

It is generally accepted that epiblast cells ingress into the primitive streak by epithelial-to-mesenchymal transition (EMT) to give rise to the mesoderm; however, it is less clear how the endoderm acquires an epithelial fate. Here, we used embryonic stem cell and mouse embryo knock-in reporter systems to combine time-resolved lineage labelling with high-resolution single-cell transcriptomics. This allowed us to resolve the morphogenetic programs that segregate the mesoderm from the endoderm germ layer. Strikingly, while the mesoderm is formed by classical EMT, the endoderm is formed independent of the key EMT transcription factor Snail1 by mechanisms of epithelial cell plasticity. Importantly, forkhead box transcription factor A2 (Foxa2) acts as an epithelial gatekeeper and EMT suppressor to shield the endoderm from undergoing a mesenchymal transition. Altogether, these results not only establish the morphogenetic details of germ layer formation, but also have broader implications for stem cell differentiation and cancer metastasis. Show less

High intake of carbohydrates, particularly sucrose, in western societies is associated with the development of non-alcoholic fatty liver (NAFL) and diabetes mellitus. It is unclear whether this is related primarily to the carbohydrate quantity or to the hormonal responses, particularly glucose-dependent insulinotropic polypeptide (GIP), which is released in the proximal intestine. Therefore, we investigated the role of GIP by comparing two glucose-fructose dimers, sucrose and Palatinose (isomaltulose), resorbed proximally or distally. The glycaemic and incretin responses to sucrose and Palatinose were studied by oral gavage and meal tests. We then analysed phenotypic and metabolic diet-induced changes in C57Bl/6J mice exposed to isoenergetic diets differing in carbohydrate type. Studies were repeated in GIP receptor knockout (Gipr(-/-)) mice and their wild-type littermates. Compared with sucrose, Palatinose intake resulted in slower glucose absorption and reduced postprandial insulin and GIP levels. After 22 weeks, Palatinose feeding prevented hepatic steatosis (48.5%) compared with sucrose and improved glucose tolerance, without differences in body composition and food intake. Ablation of GIP signalling in Gipr(-/-) mice completely prevented the deleterious metabolic effects of sucrose feeding. Furthermore, our microarray analysis indicated that sucrose increased 2.3-fold the hepatic expression of Socs2, which is involved in the growth hormone signalling pathway and participates in the development of NAFL. Our results suggest that the site of glucose absorption and the GIP response determine liver fat accumulation and insulin resistance. GIP may play a role in sucrose induced fatty liver by regulating the expression of Socs2. Show less

The neuroendocrine control of reproduction in mammals is governed by a neural hypothalamic network of nearly 1500 gonadotropin-releasing hormone (GnRH) secreting neurons that modulate the activity of the reproductive axis across life. Congenital hypogonadotropic hypogonadism (HH) is a clinical syndrome that is characterized by partial or complete pubertal failure. HH may result from inadequate hypothalamic GnRH axis activation, or a failure of pituitary gonadotropin secretion/effects. In man, several genes that participate in olfactory and GnRH neuronal migration are thought to interact during the embryonic life. A growing number of mutations in different genes are responsible for congenital HH. Based on the presence or absence of olfaction dysfunction, HH is divided in two syndromes: HH with olfactory alterations [Kallmann syndrome (KS)] and idiopathic hypogonadotropic hypogonadism (IHH) with normal smell (normosmic IHH). KS is a heterogeneous disorder affecting 1 in 5000 males, with a three to fivefold of males over females. KS is associated with mutations in KAL1, FGFR1/FGF8, FGF17, IL17RD, PROK2/PROKR2, NELF, CHD7, HS6ST1, FLRT3, SPRY4, DUSP6, SEMA3A, NELF, and WDR11 genes that are related to defects in neuronal migration. These reproductive and olfactory deficits include a variable non-reproductive phenotype, including sensorineural deafness, coloboma, bimanual synkinesis, craniofacial abnormalities, and/or renal agenesis. Interestingly, defects in PROKR2, FGFR1, FGF8, CHD7, DUSP6, and WDR11 genes are also associated with normosmic IHH, whereas mutations in KISS1/KISSR, TAC3/TACR3, GNRH1/GNRHR, LEP/LEPR, HESX1, FSHB, and LHB are only present in patients with normosmic IHH. In this paper, we summarize the reproductive, neurodevelopmental, and genetic aspects of HH in human pathology. Show less

Mechanisms explaining the relationship in non-alcoholic fatty liver disease (NAFLD), obesity, and insulin resistance are poorly understood. A genetic basis has been suggested. We studied the association between the genes patatin-like phospholipase domain-containing protein 3 (PNPLA3) and apolipoprotein C3 (APOC3) and metabolic and histological parameters of NAFLD in obese patients. Overweight and obese patients underwent a metabolic and liver assessment. If NAFLD was suspected, liver biopsy was proposed. APOC3 variant rs2854117 and PNPLA3 variant rs738409 were genotyped. Four hundred seventy patients were included (61.1% had liver biopsy). The percentage of patients with non-alcoholic steatohepatitis (NASH) was significantly different according to the PNPLA3 variant. After adjustment for age and body mass index, the PNPLA3 variant was associated with alanine aminotransferase (P < 0.001) and aspartate aminotransferase (P < 0.001). The PNPLA3 variant was associated with more severe features of steatohepatitis: steatosis (P < 0.001), lobular inflammation (P < 0.001), and ballooning (P = 0.002), but not with liver fibrosis, anthropometry, or insulin resistance. No significant difference in liver histology, anthropometric, or metabolic parameters was found between carriers and non-carriers of the APOC3 variant. PNPLA3 polymorphism rs738409 was associated with NASH and the severity of necroinflammatory changes independently of metabolic factors. No association between APOC3 gene variant rs2854117 and histological or metabolic parameters of NAFLD was found. Show less