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Abstract Background Retinoid Receptors are involved in development and cell homeostasis. Alterations of their expressions have been observed in lung cancer. However, retinoid chemoprevention trials in populations at risk to develop such tumors have failed. Therefore, the pertinence of new clinical trials using second generation retinoid requires prior better understanding of retinoid signalling. This is our aim when validating extensively research tools, focused on Retinoic Acid Receptor beta, whose major role in lung cancer is documented. Methods Biocomputing was used to assess the genomic organization of RAR beta. Its putative RAR-beta1' promoter features were investigated experimentally. Specific measures realized, with qRT-PCR Syber Green assays and a triplex of Taqman probes, were extensively validated to establish Retinoid Receptors mRNAs reference values for in vivo normal human bronchial cells, lung tumors and cell lines. Finally, a pan-RAR-beta antibody was generated and extensively validated by western-blot and immunoprecipitation. Results No promoter-like activity was found for RAR-beta1'. RAR-beta2 mRNAs increase signs the normal differentiation of the human bronchial epithelium while a decrease is observed in most lung cancer cell lines. Accordingly, it is also, along with RXR beta, down-regulated in lung tumors. When using nuclear extracts of BEAS-2B and normal lung cells, only the RAR-beta2 long protein isoform was recognized by our antibody. Conclusion Rigorous samples processing and extensive biocomputing, were the key factors for this study. mRNA reference values and validated tools can now be used to advance researches on retinoid signalling in the lung.

Context: Liver function abnormalities have been reported in patients with Turner syndrome (TS); however, the pathophysiological mechanisms have not been well elucidated. Low-grade inflammation has been associated with metabolic dysfunction-associated steatotic liver disease., Objective: We studied systemic inflammatory indices [aspartate transaminase to lymphocyte ratio index (ALRI), aspartate transaminase to platelet ratio index (APRI), gamma-glutamyl transferase to platelet ratio (GPR), neutrophil-lymphocyte-ratio (NLR), and platelet lymphocyte ratio and examined their associations with the hepatic abnormalities observed in these subjects., Methods: We performed a retrospective analysis of the medical records of 79 patients with TS (mean age 32.5 ± 9.2 SD years) who were treated at the University Hospital of Nancy. Using matched-pair analyses based on age and body mass index (BMI), we compared 66 patients with TS (25.6 ± 7.3 years; BMI 25.9 ± 6.3 kg/m 2 ) to 66 healthy control participants (24.7 ± 6.8 years; BMI 26 ± 6.7 kg/m 2 )., Results: Liver function abnormalities were present in 57% of the patients with TS. The ALRI, APRI, GPR, and NLR were significantly greater in patients with TS who presented with liver dysfunction than in patients with TS who had normal liver function. According to the matched-pair analyses, the ALRI, APRI, and GPR were greater in patients with TS than in healthy control participants. Logistic regression revealed that a diagnosis of TS was significantly associated with ALRI, APRI, and GPR and liver dysfunction., Conclusion: Noninvasive inflammatory indices (ALRI, APRI, and GPR) might be a promising indicators of liver dysfunction in patients with TS. Future prospective studies are needed to confirm our findings and to explore the clinical significance and prognostic value of systemic inflammatory indices in Turner syndrome., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Vitamin B12 (cobalamin, cbl) is a cofactor of methionine synthase (MTR) in the synthesis of methionine, the precursor of the universal methyl donor S-Adenosylmethionine (SAM), which is involved in epigenomic regulatory mechanisms. We have established a neuronal cell model with stable expression of a transcobalamin-oleosin chimer and subsequent decreased cellular availability of vitamin B12, which produces reduced proliferation, increased apoptosis and accelerated differentiation through PP2A, NGF and TACE pathways. Anti-transcobalamin antibody or impaired transcobalamin receptor expression produce also impaired proliferation in other cells. Consistently, the transcription, protein expression and activity of MTR are increased in proliferating cells of skin and intestinal epitheliums, in rat intestine crypts and in proliferating CaCo2 cells, while MTR activity correlates with DNA methylation in rat intestine villi. Exposure to nitrous oxide in animal models identified impairment of MTR reaction as the most important metabolic cause of neurological manifestations of B12 deficiency. Early vitamin B12 and folate deprivation during gestation and lactation of a 'dam-progeny' rat model developed in our laboratory is associated with long-lasting disabilities of behavior and memory capacities, with persisting hallmarks related to increased apoptosis, impaired neurogenesis and altered plasticity. We found also an epigenomic deregulation of energy metabolism and fatty acids beta-oxidation in myocardium and liver, through imbalanced methylation/acetylation of PGC-1alpha and decreased expression of SIRT1. These nutrigenomic effects display similarities with the molecular mechanisms of fetal programming. Beside deficiency, B12 loading increases the expression of MTR through internal ribosome entry sites (IRES) and down-regulates MDR-1 gene expression. In conclusion, vitamin B12 influences cell proliferation, differentiation and apoptosis in brain. Vitamin B12 and folate combined deficiency impairs fatty acid oxidation and energy metabolism in liver and heart through epigenomic mechanisms related to imbalanced acetylation/methylation. Some but not all of these effects reflect the upstream role of vitamin B12 in SAM synthesis., (Copyright © 2013. Published by Elsevier Masson SAS.)

Survival in the wild requires organismal adaptations to the availability of nutrients. Endosomes and lysosomes are key intracellular organelles that couple nutrition and metabolic status to cellular responses, but how they detect cytosolic ATP levels is not well understood. Here, we identify an endolysosomal ATP-sensitive Na(+) channel (lysoNa(ATP)). The channel is a complex formed by two-pore channels (TPC1 and TPC2), ion channels previously thought to be gated by nicotinic acid adenine dinucleotide phosphate (NAADP), and the mammalian target of rapamycin (mTOR). The channel complex detects nutrient status, becomes constitutively open upon nutrient removal and mTOR translocation off the lysosomal membrane, and controls the lysosome's membrane potential, pH stability, and amino acid homeostasis. Mutant mice lacking lysoNa(ATP) have much reduced exercise endurance after fasting. Thus, TPCs make up an ion channel family that couples the cell's metabolic state to endolysosomal function and are crucial for physical endurance during food restriction., (Copyright © 2013 Elsevier Inc. All rights reserved.)