Frühbeck, G. (Gema)
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- NLRP3 inflammasome: a possible link between obesity-associated low-grade chronic inflammation and colorectal cancer development(NCBI, 2018) Unamuno, X. (Xabier); Marti, P. (Pablo); Baixauli-Fons, J. (Jorge); Catalan, V. (Victoria); Ahechu-Garayoa, P. (Patricia); Zozaya-Larequi, G. (Gabriel); Frühbeck, G. (Gema); Hernandez-Lizoain, J.L. (Jose Luis)Emerging evidence reveals that adipose tissue-associated inflammation is a main mechanism whereby obesity promotes colorectal cancer risk and progression. Increased inflammasome activity in adipose tissue has been proposed as an important mediator of obesity-induced inflammation and insulin resistance development. Chronic inflammation in tumor microenvironments has a great impact on tumor development and immunity, representing a key factor in the response to therapy. In this context, the inflammasomes, main components of the innate immune system, play an important role in cancer development showing tumor promoting or tumor suppressive actions depending on the type of tumor, the specific inflammasome involved, and the downstream effector molecules. The inflammasomes are large multiprotein complexes with the capacity to regulate the activation of caspase-1. In turn, caspase-1 enhances the proteolytic cleavage and the secretion of the inflammatory cytokines interleukin (IL)-1 beta and IL-18, leading to infiltration of more immune cells and resulting in the generation and maintenance of an inflammatory microenvironment surrounding cancer cells. The inflammasomes also regulate pyroptosis, a rapid and inflammation-associated form of cell death. Recent studies indicate that the inflammasomes can be activated by fatty acids and high glucose levels linking metabolic danger signals to the activation of inflammation and cancer development. These data suggest that activation of the inflammasomes may represent a crucial step in the obesity-associated cancer development. This review will also focus on the potential of inflammasome-activated pathways to develop new therapeutic strategies for the prevention and treatment of obesity-associated colorectal cancer development.
- Increased expression levels of netrin-1 in visceral adipose tissue during obesity favour colon cancer cell migration(2023) Neira, G. (Gabriela); Valenti, V. (Víctor); Ferro, A. (Alberto); Baixauli-Fons, J. (Jorge); Ramirez, B. (Beatriz); Catalan, V. (Victoria); Mentxaka, A. (Amaia); Becerril, S. (Sara); Frühbeck, G. (Gema); Burrell, M.A. (María Ángela); Moncada, R. (Rafael); Silva, C. (Camilo); Gomez-Ambrosi, J. (Javier); Rodriguez, A. (Amaia); Claro, V. (Vasco)Simple Summary Netrin-1 (NTN-1) regulates obesity-associated low-grade inflammation, being also involved in the control of cell migration and proliferation. We aim to study whether excess visceral adipose tissue in patients with obesity and colon cancer is associated with increased NTN1 and the expression levels of its main receptors, promoting an inflammatory microenvironment that favours colon cancer development. Increased expression levels of NTN1 and its receptor NEO1 in the visceral adipose tissue from patients with obesity and colon cancer together with elevated DCC and UNC5B mRNA levels in patients with colon cancer were found. Moreover, the treatment of colorectal cancer cells with NTN-1 and with the adipocyte-derived secretome obtained from patients with obesity increased the migration of colorectal cancer cells. These results suggest that NTN-1 plays an important role in obesity-associated colon cancer development. Netrin (NTN)-1, an extracellular matrix protein with a crucial role in inflammation, is dysregulated during obesity (OB) and influences colon cancer (CC) progression. To decipher the mechanisms underlying CC development during obesity, we examined the expression of NTN1 and its receptors in the visceral adipose tissue (VAT) of 74 (25 normal weight (NW)) (16 with CC) and 49 patients with OB (12 with CC). We also evaluated the effect of caloric restriction (CR) on the gene expression levels of Ntn1 and its receptors in the colon from a rat model fed a normal diet. The impact of adipocyte-conditioned media (ACM) from patients with OB and NTN-1 was assessed on the expression levels of neogenin 1(NEO1), deleted in colorectal carcinomas (DCC) and uncoordinated-5 homolog B (UNC5B) in Caco-2 and HT-29 human colorectal cell lines, as well as on Caco-2 cell migration. Increased NTN1 and NEO1 mRNA levels in VAT were due to OB (p < 0.05) and CC (p < 0.001). In addition, an upregulation in the expression levels of DCC and UNC5B in patients with CC (p < 0.01 and p < 0.05, respectively) was observed. Decreased (p < 0.01) Ntn1 levels in the colon from rats submitted to CR were found. In vitro experiments showed that ACM increased DCC (p < 0.05) and NEO1 (p < 0.01) mRNA levels in HT-29 and Caco-2 cell lines, respectively, while UNC5B decreased (p < 0.01) in HT-29. The treatment with NTN-1 increased (p < 0.05) NEO1 mRNA levels in HT-29 cells and DCC (p < 0.05) in both cell lines. Finally, we revealed a potent migratory effect of ACM and NTN-1 on Caco-2 cells. Collectively, these findings point to increased NTN-1 during OB and CC fuelling cancer progression and exerting a strong migratory effect on colon cancer cells.
- Targeted disruption of the iNOS gene improves adipose tissue inflammation and fibrosis in leptin-deficient ob/ob mice: role of tenascin C(Nature, 2018) Unamuno, X. (Xabier); Sainz, N. (N.); Catalan, V. (Victoria); Becerril, S. (Sara); Frühbeck, G. (Gema); Llorente-Ortega, M. (Marcos); Gomez-Ambrosi, J. (Javier); Rodriguez, A. (Amaia); Ramírez, L. (L.); Méndez-Giménez-de-los-Galanes, L. (Leire)Background/Objectives: Obesity is related to a dynamic extracellular matrix (ECM) remodeling, which involves the synthesis and degradation of different proteins, such as tenascin C (TNC) in the adipose tissue (AT). Given the functional relationship between leptin and inducible nitric oxide synthase (iNOS), our aim was to analyze the impact of the absence of the iNOS gene in AT inflammation and ECM remodeling in ob/ob mice. Subjects/Methods: The expression of genes involved in inflammation and ECM remodeling was evaluated in 10-week-old male double knockout (DBKO) mice simultaneously lacking the ob and iNOS genes as well as in ob/ob mice classified into three groups [control, leptin-treated (1 mg kg−1 day−1 ) and pair-fed]. Results: Leptin deficiency increased inflammation and fibrosis in AT. As expected, leptin treatment improved the obesity phenotype. iNOS deficiency in ob/ob mice improved insulin sensitivity, AT inflammation, and ECM remodeling, as evidenced by lower AT macrophage infiltration and collagen deposition, a downregulation of proinflammatory and profibrogenic genes Tnf, Emr1, Hif1a, Col6a1, Col6a3, and Tnc, as well as lower circulating TNC levels. Interestingly, leptin upregulated TNC expression and release in 3T3-L1 adipocytes, and iNOS knockdown in 3T3-L1 fat cells produced a significant decrease in basal and leptin-induced Tnc expression. Conclusions: Ablation of iNOS in leptin-deficient mice improved AT inflammation and ECM remodeling-related genes, attenuating fibrosis, and metabolic dysfunction. The activation of iNOS by leptin is necessary for the synthesis and secretion of TNC in adipocytes, suggesting an important role of this alarmin in the development of AT inflammation and fibrosis.
- Factors related to increased resting energy expenditure in men with liver cirrhosis(2016) Prieto-Frías, C. (Cesár); Conchillo, M. (M.); Payeras, M. (Marina); Iñarrairaegui, M. (Mercedes); D'Avola, D. (Delia); Frühbeck, G. (Gema); Salvador, J. (Javier); Rodriguez, M. (Macarena); Richter, J.A. (José Ángel); Mugueta, C. (Carmen); Gil-Maria, J. (Jesús); Herrero, I. (Ignacio); Prieto, J. (Jesús); Sangro, B. (Bruno); Quiroga, J. (Jorge)Objective Hypermetabolism in cirrhosis is associated with a high risk of complications and mortality. However, studies about underlying mechanisms are usually focussed on isolated potential determinants and specific etiologies, with contradictory results. We aimed at investigating differences in nutrition, metabolic hormones, and hepatic function between hypermetabolic and nonhypermetabolic men with cirrhosis of the liver. Patients and methods We prospectively enrolled 48 male cirrhotic inpatients. We evaluated their resting energy expenditure (REE) and substrate utilization by indirect calorimetry, body composition by dual-energy X-ray absorptiometry, liver function, and levels of major hormones involved in energy metabolism by serum sample tests. Patients with ascites, specific metabolic disturbances, and hepatocellular carcinoma were excluded. Results REE and REE adjusted per fat-free mass (FFM) were significantly increased in cirrhotic patients. Overall, 58.3% of cirrhotic patients were classified as hypermetabolic. Groups did not differ significantly in age, etiology of cirrhosis, liver function, presence of ascites, use of diuretics, β-blockers, or presence of transjugular intrahepatic portosystemic shunts. Hypermetabolic cirrhotic patients had lower weight, BMI (P< 0.05), nonprotein respiratory quotient (P< 0.01), leptin (P<0.05), and leptin adjusted per fat mass (FM) (P<0.05), but higher FFM% (P< 0.05) and insulin resistance [homeostatic model assessment-insulin resistance (HOMA-IR)] (P<0.05). Only HOMA-IR, leptin/FM, and FFM% were independently related to the presence of hypermetabolism. Conclusion Hypermetabolic cirrhotic men are characterized by lower weight, higher FFM%, insulin resistance, and lower leptin/FM when compared with nonhypermetabolic men. HOMA-IR, FFM%, and leptin/FM were independently associated with hypermetabolism, and may serve as easily detectable markers of this condition in daily clinical practice
- Increased adipose tissue expression of lipocalin-2 in obesity is related to inflammation and matrix metalloproteinase-2 and metalloproteinase-9 activities in humans(Elsevier Scientific Pub, 2009) Rotellar, F. (Fernando); Ramirez, B. (Beatriz); Catalan, V. (Victoria); Álvarez-Cienfuegos, J. (Javier); Frühbeck, G. (Gema); Silva, C. (Camilo); Gomez-Ambrosi, J. (Javier); Salvador, J. (Javier); Rodriguez, A. (Amaia); Gil, M.J. (María José)Abstract Lipocalin-2 (LCN2) is a novel adipokine with potential roles in obesity, insulin resistance, and inflammation. The aim of the present work was to evaluate the effect of obesity on circulating concentrations and gene and protein expression levels of LCN2 in human visceral adipose tissue (VAT) as well as its involvement in inflammation. VAT biopsies from 47 subjects were used in the study. Real-time PCR and Western-blot analyses were performed to quantify levels of LCN2 in VAT as well as the association with other genes implicated in inflammatory pathways. Forty-four serum samples were used to analyze the circulating concentrations of LCN2. Zymography analysis was used to determine the activity of matrix metalloproteinase (MMP) in VAT. Obese patients exhibited increased mRNA (p<0.0001) and protein (p=0.017) expression levels of LCN2 compared to lean subjects. Although no differences in plasma LCN2 concentrations were observed, increased circulating LCN2/MMP-9 complex levels were found (p=0.038) in the obese group. Moreover, obese individuals showed increased (p<0.01) activity of MMP-2 and MMP-9/LCN2 complex, while a positive correlation (p<0.01) between MMP-2 and MMP-9 activities and BMI was observed. Gene and protein expression levels of LCN2 in VAT were positively associated with inflammatory markers (p<0.01). These findings represent the first observation that mRNA and protein levels of LCN2 are increased in human VAT of obese subjects. Furthermore, LCN2 is associated with MMP-2 and MMP-9 activities as well as with proinflammatory markers suggesting its potential involvement in the low-grade chronic inflammation accompanying obesity.
- Cardiometabolic risk stratification using a novel obesity phenotyping system based on body adiposity and waist circumference(Elsevier B.V., 2024) Marugan-Pinos, R. (Rocío); Perdomo-Zelaya, C.M. (Carolina M.); Ramirez, B. (Beatriz); Catalan, V. (Victoria); Aguas-Ayesa, M. (Maite); Becerril, S. (Sara); Frühbeck, G. (Gema); Olazarán, L. (Laura); Salmón-Gómez, L. (Laura); Silva, C. (Camilo); Gomez-Ambrosi, J. (Javier); Rodriguez, A. (Amaia); Escalada, J. (Javier); Yárnoz-Esquiroz, P. (Patricia)Background: The estimation of obesity-associated cardiometabolic risk does not usually take into account body composition or the distribution of adiposity. The aim of the present study was to assess the clinical usefulness of a novel obesity phenotyping system based on the combination of actual body fat percentage (BF%) and waist circumference (WC) according to the cardiometabolic risk estimation. Methods: A classification matrix combining BF% and WC as measures of both amount and distribution of adiposity establishing nine body phenotypes (3 BF% x 3 WC) was developed. Individuals were grouped in five different cardiometabolic risk phenotypes. We conducted a validation study in a large cohort of White subjects from both genders representing a wide range of ages and adiposity (n = 12,754; 65 % females, aged 18–88 years). Results: The five risk groups using the matrix combination of BF% and WC exhibited a robust linear distribution regarding cardiometabolic risk, estimated by the Metabolic Syndrome Severity Score, showing a continuous increase between groups with significant differences (P < 0.001) among them, as well as in other cardiometabolic risk factors. An additional 24 % of patients at very high risk was detected with the new classification system proposed (P < 0.001) as compared to an equivalent matrix using BMI and WC instead of BF% and WC. Conclusions: A more detailed phenotyping should be a priority in the diagnosis and management of patients with obesity. Our classification system allows to gradually estimate the cardiometabolic risk according to BF% and WC, thus representing a novel and useful tool for both research and clinical practice.
- Obesity and COVID-19: A perspective from the european association for the study of obesity on immunological perturbations, therapeutic challenges, and opportunities in obesity(Karger, 2020) Farpour-Lambert, N. (Nathalie); Woodward, E. (Euan); Holm, J.C. (Jens-Christian); Mullerova, D. (Dana); Frühbeck, G. (Gema); Dicker, D. (Dror); Goossens, G.H. (Gijs H.)Accumulating evidence suggests that obesity is a major risk factor for the initiation, progression, and outcomes of coronavirus disease 2019 (COVID-19). The European Association for the Study of Obesity (EASO), as a scientific and medical society dedicated to the promotion of health and well-being, is greatly concerned about the concomitant obesity and COVID-19 pandemics and their impact on health and society at large. In this perspective, we will address the inherent immunological perturbations and alterations in the renin-angiotensin-aldosterone system in patients with obesity and COVID-19, and discuss how these impairments may underlie the increased susceptibility and more detrimental outcomes of COVID-19 in people with obesity. Clearly, this has important implications for preventive measures, vaccination, and future therapeutic strategies to combat COVID-19. Furthermore, we will highlight important knowledge gaps and provide suggestions for future research and recommendations for policy actions. Since many new reports on COVID-19 rapidly appear, the present perspective should be seen as a focus for discussion to drive forward further understanding, research initiatives, and clinical management of COVID-19.
- Metrics: Reflections on the 2020s impact factors(Wiley, 2021) Catalan, V. (Victoria); Frühbeck, G. (Gema); Gomez-Ambrosi, J. (Javier)As soon as the new impact factors (IF) are released, we start receiving dozens of emails from the journals celebrating the rise in their specific IF. However, this year's global rise in IF is particularly surprising. In the 2020 edition, the average IF of the journals in the Science Edition of JCR has increased 25.1% as compared to 2019 (Figure 1), representing more than four times the average increase in the three previous years (6.2%). Noteworthy, the IF of the 25 top journals in the list has risen 34%. Since the number of journals has only increased 1.3% (slightly lower than precedent years) and the number of citable items remains more or less constant, it might be speculated that this is due to an increase in citations (equating 25.7%, similar to the average increase in the IF). Precisely, according to Clarivate's web page,1 this year's release introduces Early Access articles ‘reflecting the earliest availability of new research as it appears in the ‘version of record’ prior to official publication’. This represents a dramatic change that needs clarification regarding its application in further years since metrics are used worldwide in evaluation processes.2 As it is expected that the new advanced content taken into account for this year's calculations cannot be taken into account next year when it is published in its final version, it is possible that next year, we will see an unprecedented decrease in the journals’ IF.
- Mejora en la calidad de vida tras cirugía bariátrica(Gobierno de Navarra, 2018) Salvador-Rodríguez, F.J. (Francisco Javier); Catalan, V. (Victoria); Frühbeck, G. (Gema); Gomez-Ambrosi, J. (Javier)La obesidad se ha convertido en las últimas décadas en una de las principales causas de morbi-mortalidad. A pesar de la alarma despertada, la pandemia sigue creciendo de forma imparable. La prevalencia de obesidad en la población adulta española se estima en un 23%. Las cifras en Navarra son similares a las encontradas en el resto del país. Tanto el sobrepeso como la obesidad se asocian a un mayor riesgo de padecer enfermedades cardiovasculares, diabetes tipo 2, dislipidemia, accidentes cerebrovasculares, síndrome de apneas obstructivas del sueño, y desarrollo de determinados tipos de cáncer. Diversos estudios apuntan que el impacto económico de la obesidad supone entre un 2 y un 7% del total del gasto sanitario, pudiendo conllevar un coste en todo el país de hasta 5.000 millones de euros anuales. A pesar del enorme problema de salud, se ha demostrado que en la práctica médica no le estamos prestando la atención necesaria
- Study of caveolin-1 gene expression in whole adipose tissue and its subfractions and during differentiation of human adipocytes(BioMed Central, 2010) Catalan, V. (Victoria); Frühbeck, G. (Gema); Ricart, W. (Wifredo); Moreno-Navarrete, J. (José); Gomez-Ambrosi, J. (Javier); Ortega, F.J. (Francisco J.); Rodriguez-Hermosa, J.I. (José I.); Fernandez-Real, J.M. (José Manuel)Caveolins are 21-24 kDa integral membrane proteins that serve as scaffolds to recruit numerous signaling molecules. Specific subclasses of caveolae carry out specific functions in cell metabolism. In particular, triglycerides are synthesized at the site of fatty acid entry in one of these caveolae classes. OBJECTIVE AND METHODS: We studied the expression of caveolin-1 (CAV-1) gene in association with metabolic variables in 90 visceral and 55 subcutaneous adipose tissue samples from subjects with a wide range of fat mass, in the stromovascular fraction (SVC) and isolated adipocytes, and during differentiation of human adipocytes. RESULTS: CAV-1 gene expression was significantly decreased in visceral adipose tissue (v-CAV-1) of obese subjects. v-CAV-1 was positively associated with several lipogenic genes such as acetyl-coA carboxylase (ACACA, r = 0.34, p = 0.004) and spot-14 (r = 0.33, p = 0.004). In non-obese subjects v-CAV-1 also correlated with fatty acid synthase (FAS, r = 0.60, p < 0.0001). Subcutaneous (sc) adipose tissue (sc-CAV-1) gene expression was not associated with these lipogenic factors when obese and non-obese subjects were studied together. In obese subjects, however, sc-CAV-1 was associated with fatty acid synthase (FAS, r = 0.36, p = 0.02), sterol regulatory element binding protein-1c (SREBP-1c (r = 0.58, p < 0.0001), ACACA (r = 0.33, p = 0.03), spot-14 (r = 0.36, p = 0.02), PPAR-gamma co-activator-1 (PGC-1, r = 0.88, n = 19). In these obese subjects, sc-CAV-1 was also associated with fasting triglycerides (r = -0.50, p < 0.0001).CAV-1 expression in mature adipocytes was significantly higher than in stromal vascular cells. CAV-1 gene expression in adipocytes from subcutaneous adipose tissue (but not in adipocytes from visceral adipose tissue) was significatively associated with fasting triglycerides. CAV-1 gene expression did not change significantly during differentiation of human preadipocytes from lean or obese subjects despite significant increase of FAS gene expression. CONCLUSION: Decreased CAV-1 gene expression was simultaneously linked to increased triglycerides and decreased lipogenic gene expression among obese subjects, paralleling the observations of hypertriglyceridemia in CAV-1 knockout mice. However, the regulation of CAV-1 gene expression seems independent of the adipogenic program.