Role of GPS2 in regulating transcription in adipose tissue and skeletal muscle differentiation

Metabolic syndrome is an umbrella term for a large network of interdependent biochemical, metabolic and physiological factors that are associated with a higher risk of cardiovascular disease, and type 2 diabetes mellitus. Physiological risk factors such as insulin resistance, elevated blood pressure, visceral adiposity, and chronic inflammation are often rooted in alterations and dysfunction of the underlying metabolic tissues of the body, such as the adipose tissue and skeletal muscle. This work focuses on elucidating molecular mechanisms of gene regulation that impact the differentiation and function of both adipose tissue and skeletal muscle using well established in vitro models as well as genetic mouse models. The first two chapters describe the transcriptional profiling of GPS2-Adiponectin-Cre specific knockout (GPS2-AKO) mice upon high fat diet feeding. We used various next generation sequencing (NGS) technologies to explore how the lack of GPS2 impact upon adipose tissue adaptation to the dietary stress on a molecular level. In the first Chapter, I discuss how RNAseq experiments performed in the epididymal white adipose tissue (eWAT), and subcutaneous white adipose tissue (scWAT) reveal a complex role for GPS2 in the regulation of mitochondrial genes, inflammation and metabolism in mature adipocytes. The second chapter utilizes single cell RNA sequencing to examine how loss of GPS2 in mature adipocytes alters the underlying stromal vascular fraction tissue environment. This work has demonstrated key roles for GPS2 in directly regulating the response of adipocytes to high fat diet stress and indirectly affecting the crosstalk between adipocytes and the underlying SVF. The third chapter explores the role of GPS2 as a key mediator of skeletal muscle cell differentiation. Given the known role of GPS2 as a transcriptional cofactor, we profiled the genomic occupancy of GPS2 across C2C12 differentiation via ChIPseq and found binding to known enhancer regions linked to important muscle differentiation terms. This led to the identification of an unexpected role for GPS2 as a required factor for the differentiation of C2C12 skeletal muscle cells in vitro

Alcamo Project: un laboratorio integrato per l’analisi e lo studio del settore officinale romano di Contrada Foggia ad Alcamo Marina (TP)

During the archaeological research activities carried out in the past three years near Alcamo Matina (TP) an officinal area of the Roman period was brought to light. The find was accidental and consisted of a series of kilns used for the cooking of ceramic material which dates back to the centuries I-V A.D. The architectonic and structural solutions adopted for the realization of the ceramic complex are very interesting, a series of kilns on various levels with a system of terracing of the ground, orientation of the axis and of the opening of the praefurnium towards the non dominant winds, alternation of containment and strengthening wall structures and structural fillings made of clay. Some studies under way help better understand the officinal complex, they focus on the analysis of the ceramic material found there and on the reconstruction of the territory on the basis of methods of satellite bearing (GPS) and on the basis of cartographic results of models on the GIS platform

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

Star-shaped conjugated systems with varying oligofluorene arm length and substitution patterns of the central BODIPY core have been synthesised, leading to two families of compounds, T-B1–T-B4 and Y-B1–Y-B4, with T- and Y-shaped motifs, respectively. Thermal stability, cyclic voltammetry, absorption and photoluminescence spectroscopy of each member of these two families were studied in order to determine their suitability as emissive materials in photonic applications

Systemic insulin sensitivity is regulated by GPS2 inhibition of AKT ubiquitination and activation in adipose tissue

OBJECTIVE: Insulin signaling plays a unique role in the regulation of energy homeostasis and the impairment of insulin action is associated with altered lipid metabolism, obesity, and Type 2 Diabetes. The main aim of this study was to provide further insight into the regulatory mechanisms governing the insulin signaling pathway by investigating the role of non-proteolytic ubiquitination in insulin-mediated activation of AKT. METHODS: The molecular mechanism of AKT regulation through ubiquitination is first dissected in vitro in 3T3-L1 preadipocytes and then validated in vivo using mice with adipo-specific deletion of GPS2, an endogenous inhibitor of Ubc13 activity (GPS2-AKO mice). RESULTS: Our results indicate that K63 ubiquitination is a critical component of AKT activation in the insulin signaling pathway and that counter-regulation of this step is provided by GPS2 preventing AKT ubiquitination through inhibition of Ubc13 enzymatic activity. Removal of this negative checkpoint, through GPS2 downregulation or genetic deletion, results in sustained activation of insulin signaling both in vitro and in vivo. As a result, the balance between lipid accumulation and utilization is shifted toward storage in the adipose tissue and GPS2-AKO mice become obese under normal laboratory chow diet. However, the adipose tissue of GPS2-AKO mice is not inflamed, the levels of circulating adiponectin are elevated, and systemic insulin sensitivity is overall improved. CONCLUSIONS: Our findings characterize a novel layer of regulation of the insulin signaling pathway based on non-proteolytic ubiquitination of AKT and define GPS2 as a previously unrecognized component of the insulin signaling cascade. In accordance with this role, we have shown that GPS2 presence in adipocytes modulates systemic metabolism by restricting the activation of insulin signaling during the fasted state, whereas in absence of GPS2, the adipose tissue is more efficient at lipid storage, and obesity becomes uncoupled from inflammation and insulin resistance

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

Star-shaped conjugated systems with varying oligofluorene arm length and substitution patterns of the central BODIPY core have been synthesised, leading to two families of compounds, T-B1-T-B4 and Y-B1-Y-B4, with T- and Y-shaped motifs, respectively. Thermal stability, cyclic voltammetry, absorption and photoluminescence spectroscopy of each member of these two families were studied in order to determine their suitability as emissive materials in photonic applications

Altered calcium metabolism in chronic renal failure

Altered calcium metabolism in chronic renal failure. A compartmental analysis of 47Ca tracer kinetic data and Ca balance measurements was employed to evaluate several indexes of Ca metabolism in patients with mild to severe renal insufficiency. Rates of Ca accretion and resorption and the size of the exchangeable Ca pools were measured. In addition, absolute measurements were made of total body Ca, P, Cl and Na by means of neutron activation analysis. Total body K was measured by whole-body counting. Total body levels of Ca, P, Na, Cl and K in patients with modest renal insufficiency did not differ from those of a normal contrast population. In patients with severe renal failure, however, there were a number of changes in Ca and P metabolism. The total body P/Ca and P/K ratios were increased above normal. Most of the patients with renal insufficiency had total body Ca levels within the normal range, when normalized for skeletal size and the age and sex of the patient. The levels of total body Ca were inversely related to the accretion rate of Ca into bone; that is, the patients with the greatest calcium deficit had the highest accretion rate. Alterations in compartment sizes and intercompartmental transfer rates were observed in severe renal failure. The increased size of an exchangeable Ca compartment together with the essentially normal levels of total body Ca suggest a translocation of skeletal Ca to soft tissue mediated by increased parathyroid hormone secretion. Further studies, including a measure of the size of the soft tissue and skeletal compartments, are required to substantiate this hypothesis.Le modification du métabolisme du calcium dans l'insuffisance rénale chronique. Une analyse compartimentale des résultats de cinétiques du traceur 47Ca et du bilan de calcium a été employée pour évaluer divers paramètres du métabolisme du calcium chez des malades atteints d'insuffisance rénale moyenne ou sévère. Les débits d'accrétion et de résorption et la taille des pools échangeables de calcium ont été déterminés. De surcroît les mesures des masses corporelles totales de Ca, P, Cl et Na ont été faites au moyen de l'activation neutronique. Le potassium total corporel a été mesuré par comptage corporel total. Les masses corporelles de Ca, P, Na, Cl et K des malades atteints d'insuffisance rénale modest ne sont pas différentes de celles d'une population normale. Chez les malades atteints d'insuffisance rénale sévère, cependant, il existe des modifications des métabolismes de Ca et P. Les rapports P/Ca et P/K de l'organisme entier sont augmentés par rapport aux valeurs normales. La plupart des malades atteints d'insuffisance rénale ont un Ca total dans l'éventail des valeurs normales quand les données sont corrigées par la masse du squelette l'âge et le sexe du malade. Le Ca total corporel est inversement corrélé au débit d'accrétion du Ca dans l'os; c'est-à-dire que les malades qui ont le déficit en calcium le plus grand ont aussi le débit d'accrétion le plus élevé. Des modifications de la taille des compartiments et des débits de transfert ont été observés dans l'insuffisance rénale sévère. L'augmentation de la taille d'un compartiment de Ca échangeable alors que le Ca total corporel est normal suggère une translocation du calcium squelettique vers les tissus mous sous l'influence d'une secrétion accrue d'hormone parathyroïdienne. Des travaux supplémentaires comprennant une mesure de la taille des compartiments tissulaires et squelettique sont nécessaires pour étayer cette hypothèse