Ovine HSP90AA1 gene promoter: functional study and epigenetic modifications

Publishe

Everything matters in a promoter. New insights on the ovine HSP90AA1gene regulation: abstract

Publishe

ISGylation drives basal breast tumour progression by promoting EGFR recycling and Akt signalling

ISG15 is an ubiquitin-like modifier that is associated with reduced survival rates in breast cancer patients. The mechanism by which ISG15 achieves this however remains elusive. We demonstrate that modification of Rab GDP-Dissociation Inhibitor Beta (GDI2) by ISG15 (ISGylation) alters endocytic recycling of the EGF receptor (EGFR) in non-interferon stimulated cells using CRISPR-knock out models for ISGylation. By regulating EGFR trafficking, ISGylation enhances EGFR recycling and sustains Akt-signalling. We further show that Akt signalling positively correlates with levels of ISG15 and its E2-ligase in basal breast cancer cohorts, confirming the link between ISGylation and Akt signalling in human tumours. Persistent and enhanced Akt activation explains the more aggressive tumour behaviour observed in human breast cancers. We show that ISGylation can act as a driver of tumour progression rather than merely being a bystander.</p

Association and functional impact of SNPs in 3’UTR CAST gene with tenderness in cattle

Publishe

Nuclear receptor NR5A2 and bone: gene expression and association with bone mineral density

ObjectiveThere is growing evidence for a link between energy and bone metabolism. The nuclear receptor subfamily 5 member A2 (NR5A2) is involved in lipid metabolism and modulates the expression of estrogen-related genes in some tissues. The objective of this study was to explore the influence of NR5A2 on bone cells and to determine whether its allelic variations are associated with bone mineral density (BMD).DesignAnalyses of gene expression by quantitative PCR and inhibition of NR5A2 expression by siRNAs were used to explore the effects of NR5A2 in osteoblasts. Femoral neck BMD and 30 single nucleotide polymorphisms (SNPs) were first analyzed in 935 postmenopausal women and the association of NR5A2 genetic variants with BMD was explored in other 1284 women in replication cohorts.ResultsNR5A2 was highly expressed in bone. The inhibition of NR5A2 confirmed that it modulates the expression of osteocalcin, osteoprotegerin, and podoplanin in osteoblasts. Two SNPs were associated with BMD in the Spanish discovery cohort (rs6663479, P=0.0014, and rs2816948, P=0.0012). A similar trend was observed in another Spanish cohort, with statistically significant differences across genotypes in the combined analysis (P=0.03). However, the association in a cohort from the United States was rather weak. Electrophoretic mobility assays and studies with luciferase reporter vectors confirmed the existence of differences in the binding of nuclear proteins and the transcriptional activity of rs2816948 alleles.ConclusionsNR5A2 modulates gene expression in osteoblasts and some allelic variants are associated with bone mass in Spanish postmenopausal women

A functional variant in the promoter region of ovine stearoyl-CoA desaturasegene (SCD) affects gene expression and fatty acid profile in muscle: abstract

Publishe

Macrophage fumarate hydratase restrains mtRNA-mediated interferon production

Metabolic rewiring underlies the effector functions of macrophages1-3, but the mechanisms involved remain incompletely defined. Here, using unbiased metabolomics and stable isotope-assisted tracing, we show that an inflammatory aspartate-argininosuccinate shunt is induced following lipopolysaccharide stimulation. The shunt, supported by increased argininosuccinate synthase (ASS1) expression, also leads to increased cytosolic fumarate levels and fumarate-mediated protein succination. Pharmacological inhibition and genetic ablation of the tricarboxylic acid cycle enzyme fumarate hydratase (FH) further increases intracellular fumarate levels. Mitochondrial respiration is also suppressed and mitochondrial membrane potential increased. RNA sequencing and proteomics analyses demonstrate that there are strong inflammatory effects resulting from FH inhibition. Notably, acute FH inhibition suppresses interleukin-10 expression, which leads to increased tumour necrosis factor secretion, an effect recapitulated by fumarate esters. Moreover, FH inhibition, but not fumarate esters, increases interferon-β production through mechanisms that are driven by mitochondrial RNA (mtRNA) release and activation of the RNA sensors TLR7, RIG-I and MDA5. This effect is recapitulated endogenously when FH is suppressed following prolonged lipopolysaccharide stimulation. Furthermore, cells from patients with systemic lupus erythematosus also exhibit FH suppression, which indicates a potential pathogenic role for this process in human disease. We therefore identify a protective role for FH in maintaining appropriate macrophage cytokine and interferon responses

Estudio genético y funcional de NR5A2, un factor de transcripción ligado a obesidad y diabetes

RESUMEN: NR5A2 es un receptor nuclear huérfano asociado al metabolismo del colesterol, sus derivados y diferenciación de tejidos, al que recientemente se ha implicado en el mantenimiento de la homeostasis de la glucosa. Además, en un estudio de asociación previo, un SNP del promotor mostró asociación con IMC. Partiendo de esto, realizamos un estudio de la posible implicación de NR5A2 en el desarrollo de enfermedades metabólicas complejas, como la obesidad o la diabetes. Realizamos un secuenciado de RNA para localizar los genes del metabolismo energético regulados por NR5A2 y empleamos como modelos líneas celulares para hígado (HepG2) y mçusculo (C2C12), con expresión de NR5A2 silenciada, sobreexpresada o activada mediante un agonista sintético. Nuestros resultados muestran que NR5A2 reduce la captación de glucosa y la síntesis de TAGs en HepG2 y favorece la captación y consumo de glucosa en C2C12, disminuyendo el de ácidos grasos. Tomando estos resultados, NR5A2 podría actuar como un agente protector contra las patologías asociadas a la resistencia a la insulina.ABSTRACT: NR5A2 is an orphan nuclear receptor associated to the cholesterol metabolism, his derivates and tissue differentiation; recently it has been associated with the control of glucose homeostasis. Furthermore, in a previous association study, a SNP located in the promoter showed association with BMI. From this, we carried out a study of the possible involvement of NR5A2 in the development of complex metabolic diseases, as obesity or diabetes. We performed a RNA sequencing to locate the energy metabolism genes that are regulated by NR5A2, and by using cellular lines as models for liver (HepG2) and muscle (C2C12) with NR5A2 expression silenced, overexpressed or activated by a synthetic agonist. Our results show that NR5A2 reduces glucose removal and TAGs synthesis in HepG2, and increases glucose removal and comsumption in C2C12, and also reduces fatty acid comsumption. Taking this results together, NR5A2 may act as a protective agent against the pathologies associated with insulin resistance