Insuline-like effects of vanadate on glucokinase activity and fructose 2,6-bisphosphate levels in the liver of diabetic rats

Streptozotocin diabetic rats showed more than a 4-fold increase in blood glucose levels, whereas hepatic glycogen, fructose 2,6-bisphosphate concentration, and 6-phosphofructo-2-kinase activity were decreased. The 'total' 6-phosphofructo-2-kinase and the 'active' (nonphosphorylated) form of the enzyme were decreased to a different extent, resulting in a fall of the 'active'/'total' activity ratio. Vanadate administration for a 2-week period restored the altered values in the diabetic rats without modifying significantly in the control animals any of the parameters studied. Glucokinase activity was essentially lacking in the diabetic animals, and vanadate treatment restored the activity to about 65% of its control value, a good correlation between the recovery of the enzyme and the blood glucose level being observed. These results show an insulin-like effect of vanadate in the whole animal and suggest that insulin and vanadate possess similar actions on hepatic intracellular events

PFKFB2 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2)

Review on PFKFB2, with data on DNA/RNA, on the protein encoded and where the gene is implicated

C12orf5 (chromosome 12 open reading frame 5)

Review on C12orf5, with data on DNA/RNA, on the protein encoded and where the gene is implicated

Evaluation of renographic and metabolic parameters in human Kidney transplantation

Background: the aim of this work is to demonstrate that the value of the mean transit time (MTT) obtained from the 99mTc-MAG3 renogram deconvolution is related to the levels of adenine nucleotides determined in cortical biopsies from transplanted kidneys. Methods: the functional state was estimated by means of the MTT and the initial height (H0) of the renal retention function obtained from the 99mTc-MAG3 renogram deconvolution and by the measure of adenine nucleotides obtained from biopsies. We studied 30 kidney graft recipients, 25 normal functioning grafts (NFG) and 5 with acute tubular necrosis (ATN). Results: the MTT is significantly longer for ATN (p < 0.001). The initial uptake values (H0) are significantly lower for ATN (p < 0.001). The sum of adenine nucleotides (SAN) is significantly greater for NFG than for ATN (p < 0.001). The values of the MTT seem to reflect the energy state of the cells in transplanted kidney. Conclusion: the analysis of MTT may be indicative of the functional metabolic recovery and thus it may be predictive of the renal graft function at least in the same extent than the biochemical analysis of a cortical renal biopsy immediately after blood reperfusion of the tissue

The Expression of TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Can Be Controlled by the Antioxidant Orchestrator NRF2 in Human Carcinoma Cells

Hyperactivation of the KEAP1-NRF2 axis is a common molecular trait in carcinomas from different origin. The transcriptional program induced by NRF2 involves antioxidant and metabolic genes that render cancer cells more capable of dealing with oxidative stress. The TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) is an important regulator of glycolysis and the pentose phosphate pathway that was described as a p53 response gene, yet TIGAR expression is detected in p53-null tumors. In this study we investigated the role of NRF2 in the regulation of TIGAR in human carcinoma cell lines. Exposure of carcinoma cells to electrophilic molecules or overexpression of NRF2 significantly increased expression of TIGAR, in parallel to the known NRF2 target genes NQO1 and G6PD. The same was observed in TP53KO cells, indicating that NRF2-mediated regulation of TIGAR is p53-independent. Accordingly, downregulation of NRF2 decreased the expression of TIGAR in carcinoma cell lines from different origin. As NRF2 is essential in the bone, we used mouse primary osteoblasts to corroborate our findings. The antioxidant response elements for NRF2 binding to the promoter of human and mouse TIGAR were described. This study provides the first evidence that NRF2 controls the expression of TIGAR at the transcriptional level

Fructose 2,6-bisphosphate in cancer cell metabolism

For a long time, pioneers in the field of cancer cell metabolism, such as Otto Warburg, have focused on the idea that tumor cells maintain high glycolytic rates even with adequate oxygen supply, in what is known as aerobic glycolysis or the Warburg effect. Recent studies have reported a more complex situation, where the tumor ecosystem plays a more critical role in cancer progression. Cancer cells display extraordinary plasticity in adapting to changes in their tumor microenvironment, developing strategies to survive and proliferate. The proliferation of cancer cells needs a high rate of energy and metabolic substrates for biosynthesis of biomolecules. These requirements are met by the metabolic reprogramming of cancer cells and others present in the tumor microenvironment, which is essential for tumor survival and spread. Metabolic reprogramming involves a complex interplay between oncogenes, tumor suppressors, growth factors and local factors in the tumor microenvironment. These factors can induce overexpression and increased activity of glycolytic isoenzymes and proteins in stromal and cancer cells which are different from those expressed in normal cells. The fructose-6-phosphate/fructose-1,6-bisphosphate cycle, catalyzed by 6-phosphofructo-1-kinase/fructose 1,6-bisphosphatase (PFK1/FBPase1) isoenzymes, plays a key role in controlling glycolytic rates. PFK1/FBpase1 activities are allosterically regulated by fructose-2,6-bisphosphate, the product of the enzymatic activity of the dual kinase/phosphatase family of enzymes: 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFKFB1-4) and TP53-induced glycolysis and apoptosis regulator (TIGAR), which show increased expression in a significant number of tumor types. In this review, the function of these isoenzymes in the regulation of metabolism, as well as the regulatory factors modulating their expression and activity in the tumor ecosystem are discussed. Targeting these isoenzymes, either directly or by inhibiting their activating factors, could be a promising approach for treating cancers

TIGAR (chromosome 12 open reading frame 5)

Human TIGAR protein consists of 270 arninoacids, with a molecular weight of 30063 Da. It is cornposed of a bisphosphatase active site in which two histidines, His-11 and His-198, and one glutamic acid, Glu-1 02, are key residues for its function TIGAR catalytic domain belongs to the histidine phosphatase superfamily of proteins, a conserved group of proteins which contain a domain with a histidine forming a phosphoenzyme transiently during the catalysis (Rigden, 2008). This domain shares similarity with enzymes ofthe phosphoglycerate rrutase fumily (PGAM) and with the bisphosphatase domain of6-phosphofructo-2-kinase/:6:uctose-2,6-bisphosphatase (PFK-2/FBPase- 2.), in which the three aminoacids in the catalytic domain are conserved. More infurmation about TIGAR protein can be found in Uniprot 0 9N088. Human TIGAR structure contains different motifs as represented in the image below (PDB reference 3DCY). The crystallized structure of Danio rerio TIGAR is available inPDB (3E9D rererence) and was published by Li and Jogl, 2009

Regulation of the MDM2-p53 pathway by the ubiquitin ligase HERC2

The p53 tumor suppressor protein is a transcription factor that plays a prominent role in protecting cells from malignant transformation. Protein levels of p53 and its transcriptional activity are tightly regulated by the ubiquitin E3 ligase MDM2, the gene expression of which is transcriptionally regulated by p53 in a negative feedback loop. The p53 protein is transcriptionally active as a tetramer, and this oligomerization state is modulated by a complex formed by NEURL4 and the ubiquitin E3 ligase HERC2. Here, we report that MDM2 forms a complex with oligomeric p53, HERC2, and NEURL4. HERC2 knockdown results in a decline in MDM2 protein levels without affecting its protein stability, as it reduces its mRNA expression by inhibition of its promoter activation. DNA damage induced by bleomycin dissociates MDM2 from the p53/HERC2/NEURL4 complex and increases the phosphorylation and acetylation of oligomeric p53 bound to HERC2 and NEURL4. Moreover, the MDM2 promoter, which contains p53‐response elements, competes with HERC2 for binding of oligomeric, phosphorylated and acetylated p53. We integrate these findings in a model showing the pivotal role of HERC2 in p53‐MDM2 loop regulation. Altogether, these new insights in p53 pathway regulation are of great interest in cancer and may provide new therapeutic targets

Efectivitat de l'aprenentatge basat en problemes (ABP) en l'assignatura de Teràpia Gènica i Molecular d'Odontologia

Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524L’aprenentatge basat en problemes (ABP) és una estratègia didàctica innovadora centrada en l’estudiant, que facilita l’adquisició d’unes habilitats i competències indispensables en l’entorn professional i que proporciona el context adequat per afavorir el treball en grup i l’aprenentatge significatiu. L’experiència que aquí descrivim neix de la necessitat de motivar i implicar els estudiants d’Odontologia (2n-4t curs) en l’aprenentatge i assoliment de les competències transversals i les específiques definides en el pla docent de l’assignatura optativa de 3 ECTS Teràpia gènica i molecular durant el curs 2013-2014. Han participat un total de 32 estudiants distribuïts en 4 grups La dinàmica de l’ABP consisteix en la resolució d’un cas entre 6 dissenyats prèviament per l'equip de profesors, que cada grup d'estudiants ha de solucionar aplicant conceptes de Teràpia Gènica per a dissenyar una estratègia terapèutica innovadora aplicada a un desordre de la salut. En aquesta comunicació es descriu l’experiència realitzada, tenint en compte aspectes metodològics, descripció de les dinàmiques de grup, avaluació de l’experiència per part dels estudiants i dels tutors, així com la seva incidència en els resultats globals de l’assignatura. Tambè se ha fet una anàlisi comparativa dels resultats d'aquest curs amb els dels cursos previs. Aquest projecte ha constituït la primera experiència amb l