The biological function of the proto-oncogene Cot/tpl-2

Capítulo 2.-- Editor: Pedro A. Lazo.Cot, as well as its murine homologue tpl-2, was discovered in a COOH–terminal truncated form that unmasks the transformation capacity of the protein. The COOH-terminal domain of wt Cot contains an amino acid sequence that is a recognition signal for degradation via proteasome, besides, this domain of wt Cot is also an autoinhibitory domain of the specific activity of the wild type form. These data explain the transformation capacity of trunc-Cot/tpl-2, that when overexpressed is capable of activating several MAP kinases pathways as well as AP-1, NFAT, and NF-κB2 transcriptional activities. Earlier sobreexpression experiments lead to the proposal that Cot/tpl-2 could be involved in proliferative signalling, but the use of new technologies such as genetically modifies mice and interference RNA end up with the already accepted hypothesis that Cot/tpl-2 is involved in immune innate and adaptive processes. Cot/tpl-2 is activated in response to the activation of the TLR/IL-1 receptor superfamily as well as in response to the activation of some receptors of the TNF family. Independently of the cell system it is accepted that in resting cells Cot/tpl-2 forms a stable and inactive complex with p105 NF-κB among other proteins to protect it from degradation, adequate TLR/IL-1R stimulation induces the activation of the IKK complex that targets p105 NF-κB to be rapidly degraded by the proteasome pathway to p50 NF-κB, a subunit of the NF-κB transcription factor. Consequently Cot/tpl-2 is released from the complex and susceptible to transduce the activatory signal, leading to the activation of the MEK1-Erk1/Erk2 pathway. However, actually it is not completely understood all the requests that Cot/tpl-2 needs to be fully active and to this end it is also accepted that Cot/tpl2 requires to be phosphorylated. In addition the possibility that the requirements vary from cell system to cell system cannot be excluded. Physiologically, Cot/tpl-2 is involved in provoking innate immunity to establish adaptive immunity. In fact it is the unique MAP3K that activates Erk1/Erk2 when the TLRs/IL-1 receptors are activated and mediates the production of proinflammatory cytokines, such as TNFα, IL-1, or IL-6. More recently it has been shown that Cot/tpl-2 has the capacity to regulate the balance between Th1 and Th2 cytokines. All these data indicate that, although mutations in Cot gene result in the expression of a protein linked with cell malignancies, physiologically wt Cot/tpl-2 is involved in innate and adaptive immunity.Our research is supported by the Plan Nacional (SAF 2008-00819) and Mutua Madrileña.Peer Reviewe

Effect of bombesin receptor subtype-3 and its synthetic agonist on signaling, glucose transport and metabolism in myocytes from patients with obesity and type 2 diabetes

Bombesin receptor subtype-3 (BRS-3) is an orphan G-protein-coupled receptor (GPCR) member of the bombesin receptor family. Several studies have suggested an association between obesity, alterations in glucose metabolism, diabetes and the BRS-3 receptor. In this study, we focused on patients simultaneously diagnosed with obesity and type 2 diabetes (OB/T2D). The analysis of BRS-3 expression in the skeletal muscle of these patients revealed a marked decrease in the expression of BRS-3 at the mRNA (23.6±1.3-fold downregulation, p<0.0001) and protein level (49±7% decrease, p<0.05) compared to the normal patients (no obesity and diabetes). Moreover, in cultured primary myocytes from patients with OB/T2D, the synthetic BRS-3 agonist, [D-Try6,β‑Ala11,Phe13,Nle14]bombesin6-14, significantly increased the phosphorylation levels of mitogen-activated protein kinase (MAPK), p90RSK1, protein kinase B (PKB) and p70s6K. Specifically, the ligand at 10-11 M induced the maximal phosphorylation of MAPKs (p42, 159±15% of the control; p44, 166±11% of the control; p<0.0001) and p90RSK1 (148±2% of the control, p<0.0001). The basal phosphorylation levels of all kinases were reduced (p<0.05) in the patients with OB/T2D compared to the normal patients. Furthermore, the BRS-3 agonist stimulated glucose transport, which was already detected at 10-12 M (133±9% of the control), reached maximal levels at 10-11 M (160±9%, p<0.0001) and was maintained at up to 10-8 M (overall mean, 153±7%; p<0.007). This effect was less promiment than that attained with 10-8 M insulin (202±9%, p=0.009). The effect of the agonist on glycogen synthase a activity achieved the maximum effect at 10-11 M (165±16% of the control; p<0.0001), which did not differ from that observed with higher concentrations of the agonist. These results suggest that muscle cells isolated from patients with OB/T2D have extremely high sensitivity to the synthetic ligand, and the effects are particularly observed on MAPK and p90RSK1 phosphorylation, as well as glucose uptake. Moreover, our data indicate that BRS-3 may prove to be useful as a potential therapeutic target for the treatment of patients with OB/T2DThis study was supported by a grant from the Instituto de Salud Carlos III (CP08/000158; PIE13/00051), Fundación Eugenio Rodríguez Pascual (12224/001) and Fundación Mutua Madrileña (12224/002), Spain. S.P.-N. is the recipient of a study contract from RETICEF (RD12/0043/008

Effects of weight loss after bariatric surgery on pulmonary function tests and aobtructive sleep apnea in morbidly obese women

Introducción: la obesidad afecta a la función respiratoria e incrementa el riesgo de síndrome de apneas-hipopneas del sueño (SAHS). Objetivo: evaluar el efecto de la cirugía bariátrica, en mujeres con obesidad mórbida, sobre la función respiratoria y sobre el índice de apneas-hipopneas (IAH) tras dos años de seguimiento. Métodos: se incluyeron 15 mujeres (índice de masa corporal [IMC] medio 50,52 ± 12,71 kg.m-2, edad media 40,13 ± 10,06 años). Los enfermos fueron analizados en dos fases: previo a la cirugía bariátrica y tras dos años de la misma. En cada visita se valoraron las medidas antropométricas y se realizaron pruebas de función respiratoria consistentes en espirometría, pletismografía, medida de la presión inspiratoria máxima y del índice de tensión-tiempo de los músculos inspiratorios, así como análisis de gases arteriales. Por último, también se efectuó una poligrafía cardiorrespiratoria durante el sueño. Resultados: tras la cirugía bariátrica el IMC disminuyó en 44,07 kg.m-2 (IC 95% 38,32 – 49,81). De igual forma, se observaron incrementos significativos en el volumen espiratorio forzado al primer segundo (FEV1) (p < 0,01), la capacidad vital forzada (FVC) (p < 0,01), el volumen de reserva espiratorio (ERV) (p = 0,040), la capacidad funcional residual (FRC) (p = 0,009) y la resistencia de las vías aéreas (Raw) (p = 0,018). Por otra parte, el IAH (p = 0,001) y el índice de desaturación de oxígeno (p = 0,001) disminuyeron tras la cirugía. Se observó una correlación significativa entre el grado de pérdida de peso y el incremento del ERV (0,774, p = 0,024). Conclusiones: tras dos años desde la cirugía bariátrica se siguen observando mejorías significativas en la función respiratoria y en la gravedad del SAHS. La mejoría del ERV estaría en relación directa con los niveles de peso perdidoIntroduction: obesity impacts on respiratory function and also it acts as a risk factor for obstructive sleep apnea (OSA). Aims: to study the effects of bariatric surgery on pulmonary function tests and on OSA in morbidly obese women over 4 years. Methods: fifteen morbidly obese women (mean body mass index [BMI] 50.52 ± 12.71 kg.m-2, mean age 40.13 ± 10.06 years) underwent pulmonary function tests (PFT) in two opportunities (before and after weight loss surgery). PFT included spirometry, body plethysmography and measure of maximal inspiratory mouth pressure (PImax) and of tension-time index for inspiratory muscles. Also, in both opportunities, resting arterial blood gas tensions were evaluated and a full night sleep register was performed. Results: BMI significantly decreased after bariatric surgery (-44.07 kg.m-2 [CI 95% -38.32 – -49.81]). Also, there was a significantly increase in forced expiratory volume in 1 second (FEV1) (p < 0.01), forced vital capacity (FVC) (p < 0.01), expiratory reserve volume (ERV) (p = 0.040), functional residual capacity (FRC) (p = 0.009) and a decline in airways resistance (Raw) (p = 0.018). Concerning sleep registers, apnea hypopnea index (p = 0.001) and desaturation index (p = 0.001) were also reduced after weight loss. Improve in ERV had a significant correlation with weight loss (r = 0.774, p = 0.024). Conclussions: pulmonary function tests and apnea hypopnea index improve after bariatric surgery in mor- bidly obese women. Improvement of ERV is well correlated with weight los

Metabolomic-Based Noninvasive Serum Test to Diagnose Nonalcoholic Steatohepatitis: Results From Discovery and Validation Cohorts

Nonalcoholic fatty liver disease (NAFLD) is the most common type of chronic liver disease worldwide and includes a broad spectrum of histologic phenotypes, ranging from simple hepatic steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). While liver biopsy is the reference gold standard for NAFLD diagnosis and staging, it has limitations due to its sampling variability, invasive nature, and high cost. Thus, there is a need for noninvasive biomarkers that are robust, reliable, and cost effective. In this study, we measured 540 lipids and amino acids in serum samples from biopsy-proven subjects with normal liver (NL), NAFL, and NASH. Using logistic regression analysis, we identified two panels of triglycerides that could first discriminate between NAFLD and NL and second between NASH and NAFL. These noninvasive tests were compared to blinded histology as a reference standard. We performed these tests in an original cohort of 467 patients with NAFLD (90 NL, 246 NAFL, and 131 NASH) that was subsequently validated in a separate cohort of 192 patients (7 NL, 109 NAFL, 76 NASH). The diagnostic performances of the validated tests showed an area under the receiver operating characteristic curve, sensitivity, and specificity of 0.88 +/- 0.05, 0.94, and 0.57, respectively, for the discrimination between NAFLD and NL and 0.79 +/- 0.04, 0.70, and 0.81, respectively, for the discrimination between NASH and NAFL. When the analysis was performed excluding patients with glucose levels >136 mg/dL, the area under the receiver operating characteristic curve for the discrimination between NASH and NAFL increased to 0.81 +/- 0.04 with sensitivity and specificity of 0.73 and 0.80, respectively. Conclusion: The assessed noninvasive lipidomic serum tests distinguish between NAFLD and NL and between NASH and NAFL with high accuracy.Supported by the National Institutes of Health Blueprint for Neuroscience Research (R01AT001576 to S.C.L., J.M.M.), Agencia Estatal de Investigacion of the Ministerio de Economia, Industria y Competitividad (SAF2014-52097R to J.M.M.), CIBER Hepatic and Digestive Diseases and Instituto de Salud Carlos III (PIE14/0003 to J.M.M.), Etorgai 2015-Gobierno Vasco (ER-2015/00015 to R.M., I.M.A., C.A., A.C.), Plan de Promocion de la Innovacion 2015-Diputacion Foral de Bizkaia (6/12/IN/2015/00131 to A.C., C.A.), National Institute of Diabetes and Digestive and Kidney Diseases (RO1DK81410 to A.J.S.), and Czech Ministry of Health (RVO VFN64165 to L.V.)

Liquid Chromatography-Mass Spectrometry-Based Parallel Metabolic Profiling of Human and Mouse Model Serum Reveals Putative Biomarkers Associated with the Progression of Nonalcoholic Fatty Liver Disease

Keywords: NAFLD, steatosis, NASH, metabolomics, biomarkers. FOOTNOTE

Metabolic subtypes of patients with NAFLD exhibit distinctive cardiovascular risk profiles

Background and Aims We previously identified subsets of patients with NAFLD with different metabolic phenotypes. Here we align metabolomic signatures with cardiovascular disease (CVD) and genetic risk factors. Approach and Results We analyzed serum metabolome from 1154 individuals with biopsy-proven NAFLD, and from four mouse models of NAFLD with impaired VLDL-triglyceride (TG) secretion, and one with normal VLDL-TG secretion. We identified three metabolic subtypes: A (47%), B (27%), and C (26%). Subtype A phenocopied the metabolome of mice with impaired VLDL-TG secretion; subtype C phenocopied the metabolome of mice with normal VLDL-TG; and subtype B showed an intermediate signature. The percent of patients with NASH and fibrosis was comparable among subtypes, although subtypes B and C exhibited higher liver enzymes. Serum VLDL-TG levels and secretion rate were lower among subtype A compared with subtypes B and C. Subtype A VLDL-TG and VLDL-apolipoprotein B concentrations were independent of steatosis, whereas subtypes B and C showed an association with these parameters. Serum TG, cholesterol, VLDL, small dense LDL5,6, and remnant lipoprotein cholesterol were lower among subtype A compared with subtypes B and C. The 10-year high risk of CVD, measured with the Framingham risk score, and the frequency of patatin-like phospholipase domain-containing protein 3 NAFLD risk allele were lower in subtype A. Conclusions Metabolomic signatures identify three NAFLD subgroups, independent of histological disease severity. These signatures align with known CVD and genetic risk factors, with subtype A exhibiting a lower CVD risk profile. This may account for the variation in hepatic versus cardiovascular outcomes, offering clinically relevant risk stratification.National Institutes of Health (R01DK123763, R01DK119437, HL151328, P30DK52574, P30DK56341, and UL1TR002345); Ministerio de Economía y Competitividad de España (SAF2017-88041-R); Ministerio de Economía y Competitividad de España for the Severo Ochoa Excellence Accreditation (SEV-2016-0644); CIBERehd (Biomedical Research Center in Hepatic and Digestive Diseases) and Netherlands Organization for Applied Scientific Research Program (PMC13 and PMC15); Spanish Carlos III Health Institute (PI15/01132 and PI18/01075); Miguel Servet Program (CON14/00129 and CPII19/00008); Fondo Europeo de Desarrollo Regional, CIBERehd, Department of Industry of the Basque Country (Elkartek: KK-2020/00008); La Caixa Scientific Foundation (HR17-00601); Liver Investigation: Testing Marker Utility in Steatohepatitis consortium funded by the Innovative Medicines Initiative Program of the European Union (777377), which receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA; Newcastle NIHR Biomedical Research Center; Czech Ministry of Health (RVO-VFN64165/2020); Fondo Nacional De Ciencia y Tecnología de Chile (1191145); and the Comisión Nacional de Investigación, Ciencia y Tecnología (AFB170005, CARE Chile UC); Agencia Nacional de Investigación y Desarrollo (ANID ACE 210009); European Union's Horizon 2020 Research and Innovation Program (825510)

Raíces y alas: recuerdos y ficciones

El segundo número de la colección Laboratorio Transmedia (ISSN: 2794-0861) contiene 36 relatos escritos durante el curso 2021/2022 por estudiantes de la Universidad para Mayores

Metabolismo de la s-adenosil-L-metionina en la cirrosis humana

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Cirugía. Fecha de lectura: 8 de Marzo de 198

Characterization of a full-length cDNA encoding human liver S-adenosylmethionine synthetase: Tissue-specific gene expression and mRNA levels in hepatopathies

The sequence of a full-length cDNA coding for human liver S-adenosylmethionine synthetase has been determined. It spans 3217 nucleotides and encodes a protein of 395 amino acid residues, with a calculated molecular mass of 43647 Da. The structural features deduced from the amino acid sequence show a close similarity to those of the rat liver enzyme. The liver-specific S-adenosylmethionine synthetase gene appears to be present as a single copy in the genome, as revealed by Southern analysis. The occurrence of a single mRNA species for this enzyme has been determined by primer extension and Northern analysis. Among several human tissues examined, this gene is expressed only in the liver. Similar S-adenosylmethionine synthetase mRNA levels have been detected in biopsies from normal human liver and from patients with alcoholic cirrhosis and hepatocellular carcinoma. Based on these results, a possible mechanism of regulation of human liver S-adenosylmethionine synthetase is discussed.This work was supported by grants from Fondo de Investigaciones Sanitarias (91/0220) and Europharma. L.A. and F. C. are fellows from Ministerio de Educación y Ciencia.Peer Reviewe

S-adenosyl-L-methionine synthetase and phospholipid methyltransferase are inhibited in human cirrhosis

We have measured the activity S-adenosyl-L-methionine synthetase in liver biopsies from a group of controls (n = 17) and in 26 cirrhotics (12 alcoholic and 14 posthepatitic). The activity of this enzyme was markedly reduced in the group of cirrhotics (285 ± 32 pmoles per min per mg protein) when compared with that observed in controls (505 ± 37 pmoles per min per mg protein). No differences in S-adenosyl-L-methionine synthetase was observed between both groups of cirrhotics. Similarly, a marked reduction in the activity phospholipid methyltransferase was also observed in liver biopsies from the same group of cirrhotics (105 ± 12 pmoles per min per mg protein) when compared with the control subjects (241 ± 13 pmoles per min per mg protein). Again, no difference in the activity of this enzyme was observed between both groups of cirrhotics. These results indicated a marked deficiency in the metabolism of S-adenosyl-L-methionine in cirrhosis.Funded by: CAICYT, FISS, EUROPHARMA.Peer Reviewe