Lack of p38 activation in T cells increases IL-35 and protects against obesity by promoting thermogenesis.

Obesity is characterized by low-grade inflammation, energy imbalance and impaired thermogenesis. The role of regulatory T cells (Treg) in inflammation-mediated maladaptive thermogenesis is not well established. Here, we find that the p38 pathway is a key regulator of T cell-mediated adipose tissue (AT) inflammation and browning. Mice with T cells specifically lacking the p38 activators MKK3/6 are protected against diet-induced obesity, leading to an improved metabolic profile, increased browning, and enhanced thermogenesis. We identify IL-35 as a driver of adipocyte thermogenic program through the ATF2/UCP1/FGF21 pathway. IL-35 limits CD8+ T cell infiltration and inflammation in AT. Interestingly, we find that IL-35 levels are reduced in visceral fat from obese patients. Mechanistically, we demonstrate that p38 controls the expression of IL-35 in human and mouse Treg cells through mTOR pathway activation. Our findings highlight p38 signaling as a molecular orchestrator of AT T cell accumulation and function.

p38γ is essential for cell cycle progression and liver tumorigenesis.

The cell cycle is a tightly regulated process that is controlled by the conserved cyclin-dependent kinase (CDK)-cyclin protein complex1. However, control of the G0-to-G1 transition is not completely understood. Here we demonstrate that p38 MAPK gamma (p38γ) acts as a CDK-like kinase and thus cooperates with CDKs, regulating entry into the cell cycle. p38γ shares high sequence homology, inhibition sensitivity and substrate specificity with CDK family members. In mouse hepatocytes, p38γ induces proliferation after partial hepatectomy by promoting the phosphorylation of retinoblastoma tumour suppressor protein at known CDK target residues. Lack of p38γ or treatment with the p38γ inhibitor pirfenidone protects against the chemically induced formation of liver tumours. Furthermore, biopsies of human hepatocellular carcinoma show high expression of p38γ, suggesting that p38γ could be a therapeutic target in the treatment of this disease.

Myeloid p38 activation maintains macrophage-liver crosstalk and BAT thermogenesis through IL-12-FGF21 axis.

Obesity features excessive fat accumulation in several body tissues and induces a state of chronic low-grade inflammation that contributes to the development of diabetes, steatosis, and insulin resistance. Recent research has shown that this chronic inflammation is crucially dependent on p38 pathway activity in macrophages, suggesting p38 inhibition as a possible treatment for obesity comorbidities. Nevertheless, we report here that lack of p38 activation in myeloid cells worsens high-fat diet-induced obesity, diabetes, and steatosis. Deficient p38 activation increases macrophage IL-12 production, leading to inhibition of hepatic FGF21 and reduction of thermogenesis in the brown fat. The implication of FGF21 in the phenotype was confirmed by its specific deletion in hepatocytes. We also found that IL-12 correlates with liver damage in human biopsies, indicating the translational potential of our results. Our findings suggest that myeloid p38 has a dual role in inflammation and that drugs targeting IL-12 might improve the homeostatic regulation of energy balance in response to metabolic stress.

125I Radioactive Seed Localization vs. Conventional Surgery for the Treatment of Mesenchymal Tumours: A Propensity Score Matching Analysis.

PURPOSE: Radioguided localization can assist the surgery of hard-to-find lesions. The aim was to evaluate the results of the 125I Radioactive Seed Localization (RSL) technique to guide a margin-free tumoral resection of mesenchymal tumours compared to conventional surgery and its influence in oncological outcomes. METHODS: Retrospective observational study of all consecutive patients who underwent 125I RSL for the surgery of a mesenchymal tumour from January 2012 to January 2020 in a tertiary referral centre in Spain. The control group was formed by patients with conventional surgery in the same period and centre. A Propensity Score matching at 1:4 ratio selected the cases for analysis. RESULTS: A total of 10 lesions excised in 8 radioguided surgeries were compared to 40 lesions excised in 40 conventional surgeries, with equal proportion of histological subtypes in each group. There was a higher proportion of recurrent tumours in the RSL group (80 % [8/10] vs. 27.5 % [11/40]; p: 0.004). An R0 was achieved in 80 % (8/10) of the RSL group and 65 % (26/40) of the conventional surgery group. The R1 rate was 0 % and 15 % (6/40), and the R2 rate was 20 % (2/10 and 8/40) in the RSL group and conventional surgery group, respectively (p: 0.569). No differences were detected in disease-free or overall survival between the different histological subtypes in the subgroup analysis. CONCLUSION: The 125I RSL technique of a challenging sample of mesenchymal tumours achieved a similar margin-free tumoral resection and oncological outcomes as conventional surgery.

The L-α-Lysophosphatidylinositol/G Protein-Coupled Receptor 55 System Induces the Development of Nonalcoholic Steatosis and Steatohepatitis.

BACKGROUND AND AIMS: G protein-coupled receptor (GPR) 55 is a putative cannabinoid receptor, and l-α-lysophosphatidylinositol (LPI) is its only known endogenous ligand. Although GPR55 has been linked to energy homeostasis in different organs, its specific role in lipid metabolism in the liver and its contribution to the pathophysiology of nonalcoholic fatty liver disease (NAFLD) remains unknown. APPROACH AND RESULTS: We measured (1) GPR55 expression in the liver of patients with NAFLD compared with individuals without obesity and without liver disease, as well as animal models with steatosis and nonalcoholic steatohepatitis (NASH), and (2) the effects of LPI and genetic disruption of GPR55 in mice, human hepatocytes, and human hepatic stellate cells. Notably, we found that circulating LPI and liver expression of GPR55 were up-regulated in patients with NASH. LPI induced adenosine monophosphate-activated protein kinase activation of acetyl-coenzyme A carboxylase (ACC) and increased lipid content in human hepatocytes and in the liver of treated mice by inducing de novo lipogenesis and decreasing ß-oxidation. The inhibition of GPR55 and ACCα blocked the effects of LPI, and the in vivo knockdown of GPR55 was sufficient to improve liver damage in mice fed a high-fat diet and in mice fed a methionine-choline-deficient diet. Finally, LPI promoted the initiation of hepatic stellate cell activation by stimulating GPR55 and activation of ACC. CONCLUSIONS: The LPI/GPR55 system plays a role in the development of NAFLD and NASH by activating ACC.

p38α blocks brown adipose tissue thermogenesis through p38δ inhibition.

Adipose tissue has emerged as an important regulator of whole-body metabolism, and its capacity to dissipate energy in the form of heat has acquired a special relevance in recent years as potential treatment for obesity. In this context, the p38MAPK pathway has arisen as a key player in the thermogenic program because it is required for the activation of brown adipose tissue (BAT) thermogenesis and participates also in the transformation of white adipose tissue (WAT) into BAT-like depot called beige/brite tissue. Here, using mice that are deficient in p38α specifically in adipose tissue (p38αFab-KO), we unexpectedly found that lack of p38α protected against high-fat diet (HFD)-induced obesity. We also showed that p38αFab-KO mice presented higher energy expenditure due to increased BAT thermogenesis. Mechanistically, we found that lack of p38α resulted in the activation of the related protein kinase family member p38δ. Our results showed that p38δ is activated in BAT by cold exposure, and lack of this kinase specifically in adipose tissue (p38δ Fab-KO) resulted in overweight together with reduced energy expenditure and lower body and skin surface temperature in the BAT region. These observations indicate that p38α probably blocks BAT thermogenesis through p38δ inhibition. Consistent with the results obtained in animals, p38α was reduced in visceral and subcutaneous adipose tissue of subjects with obesity and was inversely correlated with body mass index (BMI). Altogether, we have elucidated a mechanism implicated in physiological BAT activation that has potential clinical implications for the treatment of obesity and related diseases such as diabetes.

p38γ and p38δ reprogram liver metabolism by modulating neutrophil infiltration.

Non-alcoholic fatty liver disease (NAFLD) is a major health problem and the main cause of liver disease in Western countries. Although NAFLD is strongly associated with obesity and insulin resistance, its pathogenesis remains poorly understood. The disease begins with an excessive accumulation of triglycerides in the liver, which stimulates an inflammatory response. Alternative p38 mitogen-activated kinases (p38γ and p38δ) have been shown to contribute to inflammation in different diseases. Here we demonstrate that p38δ is elevated in livers of obese patients with NAFLD and that mice lacking p38γ/δ in myeloid cells are resistant to diet-induced fatty liver, hepatic triglyceride accumulation and glucose intolerance. This protective effect is due to defective migration of p38γ/δ-deficient neutrophils to the damaged liver. We further show that neutrophil infiltration in wild-type mice contributes to steatosis development by means of inflammation and liver metabolic changes. Therefore, p38γ and p38δ in myeloid cells provide a potential target for NAFLD therapy.

Remodeling p38 signaling in muscle controls locomotor activity via IL-15.

Skeletal muscle has gained recognition as an endocrine organ releasing myokines upon contraction during physical exercise. These myokines exert both local and pleiotropic health benefits, underscoring the crucial role of muscle function in countering obesity and contributing to the overall positive effects of exercise on health. Here, we found that exercise activates muscle p38γ, increasing locomotor activity through the secretion of interleukin-15 (IL-15). IL-15 signals in the motor cortex, stimulating locomotor activity. This activation of muscle p38γ, leading to an increase locomotor activity, plays a crucial role in reducing the risk of diabetes and liver steatosis, unveiling a vital muscle-brain communication pathway with profound clinical implications. The correlation between p38γ activation in human muscle during acute exercise and increased blood IL-15 levels highlights the potential therapeutic relevance of this pathway in treating obesity and metabolic diseases. These findings provide valuable insights into the molecular basis of exercise-induced myokine responses promoting physical activity.

Radioguided surgery of mesenchymal tumors with 125I seeds.

INTRODUCTION: Radioguided surgery uses radioactive substances to identify and remove hard-to-locate lesions. Mesenchymal tumors constitute a heterogeneous group of neoplasms derived from the mesoderm, including benign lesions and malignant sarcomas. The aim of this study was to evaluate the ability of 125I radioactive seeds to guide intraoperative localization of mesenchymal tumors, analyzing the complication rates and evaluating the margins of the surgical specimens retrieved. METHODS: Retrospective observational study of all consecutive patients undergoing radioguided surgery of a mesenchymal tumor with a 125I radioactive seed from January 2012 to January 2020 at a tertiary referral center in Spain. The seed was inserted percutaneously guided by ultrasound or computed tomography in an outpatient setting. RESULTS: Fifteen lesions were resected in 11 interventions in 11 patients, recovering all lesions marked (100%) with a 125I seed. The lesions included areas of benign fibrosis (26.7%), cellular angiofibroma (6.7%), desmoid tumor (20%), solitary fibrous tumor (13.3%), chondrosarcoma (6.7%), and pleomorphic sarcoma (26.7%), with a high rate of recurrent tumors (60%). There was only one complication (6.7%) due to the seed falling within the surgical bed. According to the UICC classification of residual tumors, 80% of the lesions resulted in an R0 resection, 6.7% were R1 resections, and 13.3% were R2 resections. CONCLUSION: Radioguided surgery is an accurate technique for the resection of hard-to-locate mesenchymal tumors.

PPAR-γ Gene Expression in Human Adipose Tissue Is Associated with Weight Loss After Sleeve Gastrectomy.

BACKGROUND: The peroxisome proliferator-activated receptor (PPAR)-γ plays a key role in adipose tissue differentiation and fat metabolism. However, it is unclear which factors may regulate its expression and whether obese patients have changes in adipose tissue expression of PPAR-γor potential regulators such as miR-27. Thus, our aims were to analyze PPAR-γ and miR-27 expression in adipose tissue of obese patients, and to correlate their levels with clinical variables. SUBJECTS AND METHODS: We included 43 morbidly obese subjects who underwent sleeve gastrectomy (31 of them completed 1-year follow-up) and 19 non-obese subjects. mRNA expression of PPAR-γ1 and PPAR-γ2, miR-27a, and miR-27b was measured by qPCR in visceral and subcutaneous adipose tissue. Clinical variables and serum adipokine and hormone levels were correlated with PPAR-γ and miR-27 expression. In addition, a systematic review of the literature regarding PPAR-γ expression in adipose tissue of obese patients was performed. RESULTS: We found no differences in the expression of PPAR-γ and miR-27 in adipose tissue of obese patients vs. controls. The literature review revealed discrepant results regarding PPAR-γ expression in adipose tissue of obese patients. Of note, we described a significant negative correlation between pre-operative PPAR-γ1 expression in adipose tissue of obese patients and post-operative weight loss, potentially linked with insulin resistance markers. CONCLUSION: PPAR-γ1 expression in adipose tissue is associated with weight loss after sleeve gastrectomy and may be used as a biomarker for response to surgery.

Neutrophil infiltration regulates clock-gene expression to organize daily hepatic metabolism.

Liver metabolism follows diurnal fluctuations through the modulation of molecular clock genes. Disruption of this molecular clock can result in metabolic disease but its potential regulation by immune cells remains unexplored. Here, we demonstrated that in steady state, neutrophils infiltrated the mouse liver following a circadian pattern and regulated hepatocyte clock-genes by neutrophil elastase (NE) secretion. NE signals through c-Jun NH2-terminal kinase (JNK) inhibiting fibroblast growth factor 21 (FGF21) and activating Bmal1 expression in the hepatocyte. Interestingly, mice with neutropenia, defective neutrophil infiltration or lacking elastase were protected against steatosis correlating with lower JNK activation, reduced Bmal1 and increased FGF21 expression, together with decreased lipogenesis in the liver. Lastly, using a cohort of human samples we found a direct correlation between JNK activation, NE levels and Bmal1 expression in the liver. This study demonstrates that neutrophils contribute to the maintenance of daily hepatic homeostasis through the regulation of the NE/JNK/Bmal1 axis.

Every day, the body's biological processes work to an internal clock known as the circadian rhythm. This rhythm is controlled by 'clock genes' that are switched on or off by daily physical and environmental cues, such as changes in light levels. These daily rhythms are very finely tuned, and disturbances can lead to serious health problems, such as diabetes or high blood pressure. The ability of the body to cycle through the circadian rhythm each day is heavily influenced by the clock of one key organ: the liver. This organ plays a critical role in converting food and drink into energy. There is evidence that neutrophils ­ white blood cells that protect the body by being the first response to inflammation ­ can influence how the liver performs its role in obese people, by for example, releasing a protein called elastase. Additionally, the levels of neutrophils circulating in the blood change following a daily pattern. Crespo, González-Terán et al. wondered whether neutrophils enter the liver at specific times of the day to control liver's daily rhythm. Crespo, González-Terán et al. revealed that neutrophils visit the liver in a pattern that peaks when it gets light and dips when it gets dark by counting the number of neutrophils in the livers of mice at different times of the day. During these visits, neutrophils secreted elastase, which activated a protein called JNK in the cells of the mice's liver. This subsequently blocked the activity of another protein, FGF21, which led to the activation of the genes that allow cells to make fat molecules for storage. JNK activation also switched on the clock gene, Bmal1, ultimately causing fat to build up in the mice's liver. Crespo, González-Terán et al. also found that, in samples from human livers, the levels of elastase, the activity of JNK, and whether the Bmal1 gene was switched on were tightly linked. This suggests that neutrophils may be controlling the liver's rhythm in humans the same way they do in mice. Overall, this research shows that neutrophils can control and reset the liver's daily rhythm using a precisely co-ordinated series of molecular changes. These insights into the liver's molecular clock suggest that elastase, JNK and BmaI1 may represent new therapeutic targets for drugs or smart medicines to treat metabolic diseases such as diabetes or high blood pressure.

Adiponectin accounts for gender differences in hepatocellular carcinoma incidence.

Hepatocellular carcinoma (HCC) is the sixth most common cancer type and the fourth leading cause of cancer-related death. This cancer appears with higher incidence in men and during obesity; however, the specific mechanisms underlying this correlation are unknown. Adipose tissue, a key organ in metabolic syndrome, shows evident gender disparities in the production of adipokines. Levels of the important adipokine adiponectin decrease in men during puberty, as well as in the obese state. Here, we show that this decrease in adiponectin levels is responsible for the increased liver cancer risk in males. We found that testosterone activates the protein JNK in mouse and human adipocytes. JNK-mediated inhibition of adiponectin secretion increases liver cancer cell proliferation, since adiponectin protects against liver cancer development through the activation of AMP-activated protein kinase (AMPK) and p38α. This study provides insight into adipose tissue to liver crosstalk and its gender relation during cancer development, having the potential to guide strategies for new cancer therapeutics.

Corrigendum: Hepatic p63 regulates steatosis via IKKß/ER stress.

This corrects the article DOI: 10.1038/ncomms15111.

Hepatic p63 regulates steatosis via IKKß/ER stress.

p53 family members control several metabolic and cellular functions. The p53 ortholog p63 modulates cellular adaptations to stress and has a major role in cell maintenance and proliferation. Here we show that p63 regulates hepatic lipid metabolism. Mice with liver-specific p53 deletion develop steatosis and show increased levels of p63. Down-regulation of p63 attenuates liver steatosis in p53 knockout mice and in diet-induced obese mice, whereas the activation of p63 induces lipid accumulation. Hepatic overexpression of N-terminal transactivation domain TAp63 induces liver steatosis through IKKß activation and the induction of ER stress, the inhibition of which rescues the liver functions. Expression of TAp63, IKKß and XBP1s is also increased in livers of obese patients with NAFLD. In cultured human hepatocytes, TAp63 inhibition protects against oleic acid-induced lipid accumulation, whereas TAp63 overexpression promotes lipid storage, an effect reversible by IKKß silencing. Our findings indicate an unexpected role of the p63/IKKß/ER stress pathway in lipid metabolism and liver disease.

MKK6 controls T3-mediated browning of white adipose tissue.

Increasing the thermogenic capacity of adipose tissue to enhance organismal energy expenditure is considered a promising therapeutic strategy to combat obesity. Here, we report that expression of the p38 MAPK activator MKK6 is elevated in white adipose tissue of obese individuals. Using knockout animals and shRNA, we show that Mkk6 deletion increases energy expenditure and thermogenic capacity of white adipose tissue, protecting mice against diet-induced obesity and the development of diabetes. Deletion of Mkk6 increases T3-stimulated UCP1 expression in adipocytes, thereby increasing their thermogenic capacity. Mechanistically, we demonstrate that, in white adipose tissue, p38 is activated by an alternative pathway involving AMPK, TAK, and TAB. Our results identify MKK6 in adipocytes as a potential therapeutic target to reduce obesity.Brown and beige adipose tissues dissipate heat via uncoupling protein 1 (UCP1). Here the authors show that the stress activated kinase MKK6 acts as a repressor of UCP1 expression, suggesting that its inhibition promotes adipose tissue browning and increases organismal energy expenditure.

Metástasis en mano de adenocarcinoma de recto. Un caso excepcional / Hand metastasis of rectal cancer. An unusual case

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Supresión de la mucosa residual vesicular tras la colecistectomía parcial / Suppression of residual mucosa after partial cholecystectomy

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