Platelet-associated biomarkers in nonalcoholic steatohepatitis: Insights from a female cohort with obesity.

BACKGROUND: There is a lack of noninvasive diagnostic methods for nonalcoholic steatohepatitis (NASH), the severe condition of metabolic dysfunction-associated steatotic liver disease (MASLD). Platelet activation, evaluated through certain related parameters, is associated with liver disease and inflammation, but previous results are inconclusive. AIM: To investigate the potential utility of platelet-related indices as noninvasive diagnostic markers for the detection and prediction of MASLD, focusing on NASH. RESULTS: We found that mean platelet volume (MPV), plateletcrit (PCT) and platelet distribution width (PDW) were increased in the severe and morbidly obese (SMO) group compared to the normal weight (NW) group. We found decreased levels of MPV in steatosis and NASH patients. MPV and PCT values were decreased in the presence of mild liver inflammation. Platelet count (PLA) and PCT values were lower in the presence of ballooning. We obtained an area under the ROC curve of 0.84 using MPV and three other variables to predict MASLD. CONCLUSIONS: Some platelet-related indices vary depending on liver condition. Here, we reported decreased MPV in MASLD presence. Moreover, we presented for the first time a predictive model using MPV, ALT levels and the presence of diabetes mellitus and metabolic syndrome to predict MASLD in obese women. Also, MPV is closely related to early liver inflammation in NASH, and PLA and PCT are related to hepatic ballooning. These indices could be widely used for the early detection of NASH since they are usually determined in routine laboratory tests.

LC/MS-Based Untargeted Metabolomics Study in Women with Nonalcoholic Steatohepatitis Associated with Morbid Obesity.

This study investigated the importance of a metabolomic analysis in a complex disease such as nonalcoholic steatohepatitis (NASH) associated with obesity. Using an untargeted metabolomics technique, we studied blood metabolites in 216 morbidly obese women with liver histological diagnosis. A total of 172 patients were diagnosed with nonalcoholic fatty liver disease (NAFLD), and 44 were diagnosed with normal liver (NL). Patients with NAFLD were classified into simple steatosis (n = 66) and NASH (n = 106) categories. A comparative analysis of metabolites levels between NASH and NL demonstrated significant differences in lipid metabolites and derivatives, mainly from the phospholipid group. In NASH, there were increased levels of several phosphatidylinositols and phosphatidylethanolamines, as well as isolated metabolites such as diacylglycerol 34:1, lyso-phosphatidylethanolamine 20:3 and sphingomyelin 38:1. By contrast, there were decreased levels of acylcarnitines, sphingomyelins and linoleic acid. These findings may facilitate identification studies of the main pathogenic metabolic pathways related to NASH and may also have a possible applicability in a panel of metabolites to be used as biomarkers in future algorithms of the disease diagnosis and its follow-up. Further confirmatory studies in groups with different ages and sexes are necessary.

LC/MS-Based Untargeted Metabolomics Analysis in Women with Morbid Obesity and Associated Type 2 Diabetes Mellitus.

Obesity is a chronic and complex disease, with an increasing incidence worldwide that is associated with metabolic disorders such as type 2 diabetes mellitus (T2DM). Thus, it is important to determine the differences between metabolically healthy obese individuals and those with metabolic disorders. The aim of this study was to perform an untargeted metabolomics assay in women with morbid obesity (MO) compared to a normal weight group, and to differentiate the metabolome of these women with MO who present with T2DM. We carried out a liquid chromatography-mass spectrometry-based untargeted metabolomics assay using serum samples of 209 Caucasian women: 73 with normal weight and 136 with MO, of which 71 had T2DM. First, we found increased levels of choline and acylglycerols and lower levels of bile acids, steroids, ceramides, glycosphingolipids, lysophosphatidylcholines, and lysophosphatidylethanolamines in MO women than in the control group. Then, in MO women with T2DM, we found increased levels of glutamate, propionyl-carnitine, bile acids, ceramides, lysophosphatidylcholine 14:0, phosphatidylinositols and phosphoethanolamines, and lower levels of Phe-Ile/Leu. Thus, we found metabolites with opposite trends of concentration in the two metabolomic analyses. These metabolites could be considered possible new factors of study in the pathogenesis of MO and associated T2DM in women.

Expression of STING in Women with Morbid Obesity and Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic hepatic disease. Although mostly benign, this disease can evolve into nonalcoholic steatohepatitis (NASH). The stimulator of interferon genes (STING) plays an important role in the immune response against stressed cells, but this protein may also be involved in liver lipogenesis and microbiota composition. In this study, the role of STING in NAFLD was evaluated by RT-qPCR to analyze STING mRNA abundance and by immunohistochemical analysis to evaluate protein expression in liver biopsies from a cohort composed of 69 women with morbid obesity classified according to their liver involvement (normal liver, n = 27; simple steatosis (SS), n = 26; NASH, n = 16). The results showed that STING mRNA expression in the liver increases with the occurrence of NAFLD, specifically in the SS stage in which the degree of steatosis is mild or moderate. Protein analysis corroborated these results. Positive correlations were observed among hepatic STING mRNA abundance and gamma-glutamyl transferase and alkaline phosphatase levels, hepatic Toll-like receptor 9 expression and some circulating microbiota-derived bile acids. In conclusion, STING may be involved in the outcome and progression of NAFLD and may be related to hepatic lipid metabolism. However, further studies are needed to confirm these findings.

Propuesta para mejorar la formación en profesionalismo y en competencias transversales en los estudios de medicina de las universidades de Cataluña / Proposal to improve training in professionalism and transversal competences in medical studies at the universities of Catalonia

Introducción: En un grupo de trabajo de la Administración de la Generalitat de Cataluña y de los decanos de las facultades con estudios de Medicina de las universidades catalanas se creó una comisión para elaborar una propuesta para fomentar la formación en profesionalismo, en humanidades y en competencias transversales de los graduados en Medicina. Desarrollo: Dicha comisión, compuesta por docentes de todas las facultades, elaboró un documento con tres objetivos específicos: a) mostrar el estado real de dicha formación en los currículos; b) proponer actividades docentes concretas para mejorar dicha formación, considerando las buenas prácticas que se están realizando en las universidades; y c) sugerir criterios y métodos de evaluación de la formación en profesionalismo o de competencias transversales y, también, evaluar competencias específicas que pueden favorecer el desarrollo de las competencias genéricas. Conclusiones: Se espera que las sugerencias presentadas puedan servir para aumentar la formación en valores profesionales, en humanidades y en competencias transversales de los futuros profesionales de la medicina, con el objetivo final de mejorar la salud de la población.(AU)

Introduction: In a working group of the Administration of the regional government of Catalonia and the deans of the faculties with medical studies of the Catalan universities, a commission was created to prepare a document to promote training in professionalism and transversal competences of graduates in Medicine. Development: This commission, made up of teachers from all the faculties, prepared a document with three specific objectives: a) show the real state of said training in the curricula; b) propose specific teaching activities to improve said training, considering those good practices that are being carried out in universities; and c) suggest criteria and methods of evaluation of training in professionalism or of transversal competences and, also, evaluate specific competences that can improve the development of generic competences. Conclusions: It is hoped that the suggestions presented can serve to increase training in professional values, in the humanities and in transversal competences of future medical professionals with the ultimate goal of improving the health of the population.(AU)

The Role of Olfactomedin 2 in the Adipose Tissue-Liver Axis and Its Implication in Obesity-Associated Nonalcoholic Fatty Liver Disease.

This study's objective was to assess the involvement of olfactomedin 2 (OLFM2), a secreted glycoprotein related to lipid metabolism regulation, in nonalcoholic fatty liver disease (NAFLD) mediated by the adipose-tissue-liver axis. OLFM2 mRNA expression was analyzed in subcutaneous (SAT) and visceral (VAT) adipose tissue by RT-qPCR. The cohort included women with normal weight (n = 16) or morbid obesity (MO, n = 60) who were subclassified into normal liver (n = 20), simple steatosis (n = 21), and nonalcoholic steatohepatitis (NASH, n = 19) groups. The results showed that OLFM2 expression in SAT was enhanced in MO individuals and in the presence of NAFLD. Specifically, OLFM2 expression in SAT was increased in mild and moderate degrees of steatosis in comparison to the absence of it. Moreover, OLFM2 expression in SAT was negatively correlated with interleukin-6 levels. On the other hand, OLFM2 expression in VAT decreased in the presence of NASH and exhibited a positive correlation with adiponectin levels. In conclusion, OLFM2 in SAT seems to be implicated in hepatic lipid accumulation. Additionally, since we previously suggested the possible implication of hepatic OLFM2 in NAFLD progression, now we propose a possible interaction between the liver and SAT, reinforcing the potential implication of this tissue in NAFLD development.

Increased Hepatic ATG7 mRNA and ATG7 Protein Expression in Nonalcoholic Steatohepatitis Associated with Obesity.

The autophagy gene ATG7 has been shown to be essential for the induction of autophagy, a process that used to be suppressed in nonalcoholic fatty liver disease (NAFLD). However, the specific role of ATG7 in NAFLD remains unclear. The aim of this study was to analyze hepatic ATG7 mRNA and ATG7 protein expression regarding obesity-associated NAFLD. Patients included women classified into normal weight (NW, n = 6) and morbid obesity (MO, n = 72). The second group was subclassified into normal liver (NL, n = 11), simple steatosis (SS, n= 29), and nonalcoholic steatohepatitis (NASH, n = 32). mRNA expression was analyzed by RT-qPCR and protein expression was evaluated by Western blotting. Our results showed that NASH patients presented higher ATG7 mRNA and ATG7 protein levels. ATG7 mRNA expression was increased in NASH compared with SS, while ATG7 protein abundance was enhanced in NASH compared with NL. ATG7 mRNA correlated negatively with the expression of some hepatic lipid metabolism-related genes and positively with endocannabinoid receptors, adiponectin hepatic expression, and omentin levels. These results suggest that ATG7-mediated autophagy may play an important role in the pathogenesis of NAFLD, especially in NASH, perhaps playing a possible protective role. However, this is a preliminary study that needs to be further studied.

Are Ingested or Inhaled Microplastics Involved in Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) has emerged as the predominant cause of chronic liver injury; however, the mechanisms underlying its progression have not been fully elucidated. Pathophysiological studies have stated that NAFLD is significantly influenced by dietary and environmental factors that could participate in the development of NAFLD through different mechanisms. Currently, "plastic pollution" is one of the most challenging environmental problems worldwide since several plastics have potential toxic or endocrine disputing properties. Specifically, the intake of microplastics (MPs) and nanoplastics (NPs) in water or diet and/or the inhalation from suspended particles is well established, and these particles have been found in human samples. Laboratory animals exposed to MPs develop inflammation, immunological responses, endocrine disruptions, and alterations in lipid and energy metabolism, among other disorders. MPs additives also demonstrated adverse reactions. There is evidence that MPs and their additives are potential "obesogens" and could participate in NAFLD pathogenesis by modifying gut microbiota composition or even worsen liver fibrosis. Although human exposure to MPs seems clear, their relationship with NAFLD requires further study, since its prevention could be a possible personalized therapeutic strategy. Adequate mitigation strategies worldwide, reducing environmental pollution and human exposure levels of MPs, could reduce the risk of NAFLD.

Increased Secreted Frizzled-Related Protein 5 mRNA Expression in the Adipose Tissue of Women with Nonalcoholic Fatty Liver Disease Associated with Obesity.

Secreted frizzled-related protein 5 (SFRP5) is an anti-inflammatory adipocytokine secreted by adipocytes that seems to be linked with nonalcoholic fatty liver disease (NAFLD). We aimed to evaluate the role of the SFRP5-wingless-MMTV integration site family member 5a (WNT5A) pathway, closely related to adipogenesis, in subcutaneous (SAT) and visceral adipose tissues (VAT) and its relationship with obesity-related NAFLD. Our cohort was composed of 60 women with morbid obesity (MO), who underwent hypocaloric diet, subclassified according to their hepatic histopathology and 15 women with normal weight. We observed increased SFRP5 mRNA expression in VAT and lower WNT5A expression in SAT in MO compared to normal weight. We found elevated SFRP5 expression in nonalcoholic steatohepatitis (NASH) in SAT and in mild simple steatosis (SS) and NASH in VAT. We observed higher WNT5A expression in SS compared to normal liver in SAT, and a peak of WNT5A expression in mild SS. To conclude, we reported increased SFRP5 mRNA expression in SAT and VAT of NAFLD-related to obesity subjects, suggesting an implication of the SFRP5-WNT5A pathway in NAFLD pathogenesis, probably due to the adipose tissue-liver axis. Since the mechanisms by which this potential interaction takes place remain elusive, more research in this field is needed.

Laparoscopic Sleeve Gastrectomy in Patients with Severe Obesity Restores Adaptive Responses Leading to Nonalcoholic Steatohepatitis.

The surgically induced remission of liver disease represents a model to investigate the signalling processes that trigger the development of nonalcoholic steatohepatitis with the aim of identifying novel therapeutic targets. We recruited patients with severe obesity with or without nonalcoholic steatohepatitis and obtained liver and plasma samples before and after laparoscopic sleeve gastrectomy for immunoblotting, immunocytochemical, metabolomic, transcriptomic and epigenetic analyses. Functional studies were performed in HepG2 cells and primary hepatocytes. Surgery was associated with a decrease in the inflammatory response and revealed the role of mitogen-activated protein kinases. Nonalcoholic steatohepatitis was associated with an increased glutaminolysis-induced production of α-ketoglutarate and the hyperactivation of mammalian target of rapamycin complex 1. These changes were crucial for adenosine monophosphate-activated protein kinase/mammalian target of rapamycin-driven pathways that modulated hepatocyte survival by coordinating apoptosis and autophagy and affected methylation-related epigenomic remodelling enzymes. Hepatic transcriptome signatures and differentially methylated genomic regions distinguished patients with and without steatohepatitis. Our results suggest that the increased glutaminolysis-induced α-ketoglutarate production and the mammalian target of rapamycin complex 1 dysregulation play a crucial role in the inefficient adaptive responses leading to steatohepatitis in obesity.

New Insights of OLFM2 and OLFM4 in Gut-Liver Axis and Their Potential Involvement in Nonalcoholic Fatty Liver Disease.

Olfactomedins (OLFMs) are a family of glycoproteins that play a relevant role in embryonic development and in some pathological processes. Although OLFM2 is involved in the regulation of the energy metabolism and OLFM4 is an important player in inflammation, innate immunity and cancer, the role of OLFMs in NAFLD-related intestinal dysbiosis remains unknown. In this study, we analysed the hepatic mRNA expression of OLFM2 and the jejunal expression of OLFM4 in a well-established cohort of women with morbid obesity (MO), classified according to their hepatic histology into normal liver (n = 27), simple steatosis (n = 26) and nonalcoholic steatohepatitis (NASH, n = 16). Our results showed that OLFM2 hepatic mRNA was higher in NASH, in advanced degrees of steatosis and in the presence of lobular inflammation. Additionally, we obtained positive correlations between hepatic OLFM2 and glucose, cholesterol, trimethylamine N-oxide and deoxycholic acid levels and hepatic fatty acid synthase, and negative associations with weight and jejunal Toll-like receptors (TLR4) and TLR5 expression. Regarding jejunal OLFM4, we observed positive correlations with circulating interleukin (IL)-8, IL-10, IL-17 and jejunal TLR9. In conclusion, OLFM2 in the liver seems to play a relevant role in NAFLD progression, while OLFM4 in the jejunum could be involved in gut dysbiosis-related inflammatory events.

NASH Presence is Associated with a Lower Weight Loss One and 2 Years After Bariatric Surgery in Women with Severe Obesity.

PURPOSE: Given that obesity is a major medical problem associated with non-alcoholic fatty liver disease and the lack of studies on postsurgery weight loss according to hepatic histology, we aimed to analyse weight loss indicators according to non-alcoholic steatohepatitis (NASH) presence one and 2 years postsurgery. MATERIALS AND METHODS: The weight loss pattern of 410 women with severe obesity (SO) was analysed after sleeve gastrectomy (SG, n = 191) and Roux-en-Y gastric bypass (RYGB, n = 219) according to NASH presence at baseline and at 12 and 24 months postsurgery. Weight loss indicators: expected BMI (eBMI), excess BMI loss percentage (%EBMIL), total weight loss percentage (%TWL) and alterable weight loss percentage (%AWL). RESULTS: Unlike RYGB, after SG, a higher percentage of NASH patients do not reach the eBMI 2 years postsurgery. %TWL and %AWL presented no differences after RYGB despite the presence of NASH. After SG, there is a worse ponderal evolution of all indicators analysed in the presence of NASH. Unlike SG, diabetic patients lose less weight than non-diabetic patients after RYGB. The presence of NASH in diabetics had no impact on weight loss indicators, but in non-diabetics, it had an impact, particularly in the SG group. CONCLUSION: The presence of NASH suggests a worse weight loss pattern through all the analysed indicators one and 2 years after SG in women. The presence of T2DM appears to result in less weight loss after RYGB, but only non-diabetic women presenting NASH lose less weight that non-diabetic women in the absence of NASH after SG.

Ischemic Conditioning in the Right Colon and Terminal Ileum: An Experimental Rat Model.

INTRODUCTION: Preoperative gastric ischemic conditioning (IC) improves the outcome of esophageal replacement gastroplasty and is associated with low morbidity. However, when the stomach cannot be used for esophageal replacement, a colonic replacement is required. The study aim was to assess the viability of right colon and terminal ileum IC in a rat model and the histological damage/recovery sequence and determine if neovascularization is a potential adaptive mechanism. METHODS: The study was conducted in Rattus norvegicus with ileocolic vascular ligation. Seven groups of animals were established (6 rats per group) with groups defined by the date of their post-IC euthanasia (+1, +3, +6, +10, +15, and +21 days). Comparisons were made with a sham group. Viability of the model was defined as <10% of transmural necrosis. The evaluation of histological damage used the Chiu score in hematoxylin and eosin sections of paraffin-embedded specimens with CD31 immunohistochemical assessment of neovascularization by the median of submucosal vessel counts in 5 high-magnification fields. RESULTS: Transmural colon necrosis occurred in 1/36 animals (2.78%) with no animal demonstrating transmural ileal necrosis. The maximum damage was observed in the colon on +1 day post-IC (average Chiu score 1.67, p = 0.015), whereas in the ileum, it was on days +1, +3, and +6 (average Chiu score 1.5, 1.3, and 1.17; p = 0.015, 0.002, and 0.015, respectively). In the +21-day group, histological recovery was complete in the colon in 4 (66.7%) of the 6 animals and in the ileum in 5 (83.3%) of 6 animals. There were no significant differences in quantitative neovascularization in any of the groups when compared with the sham group or when comparisons were made between groups. CONCLUSIONS: The tested animal model for IC of the colon and terminal ileum appeared to be feasible. Histological damage was maximal between the 1st and 3rd day following IC, but by day 21, recovery was complete in two-thirds of the rats. There was no evidence in this preliminary IC model that would suggest neovascularization as an adaptive mechanism.

Expression of Jejunal Taste Receptors in Women with Morbid Obesity.

Nutrient sensing plays important roles in promoting satiety and maintaining good homeostatic control. Taste receptors (TAS) are located through the gastrointestinal tract, and recent studies have shown they have a relationship with metabolic disorders. The aim of this study was to analyze the jejunal expression of TAS1R2, TAS1R3, TAS2R14 and TAS2R38 in women with morbid obesity, first classified according to metabolic syndrome presence (MetS; n = 24) or absence (non-MetS; n = 45) and then classified according to hepatic histology as normal liver (n = 28) or nonalcoholic fatty liver disease (n = 41). Regarding MetS, we found decreased expression of TAS2R14 in MetS patients. However, when we subclassified patients according to liver histology, we did not find differences between groups. We found negative correlations between glucose levels, triglycerides and MetS with TAS1R3 expression. Moreover, TAS2R14 jejunal expression correlated negatively with the presence of MetS and ghrelin levels and positively with the jejunal Toll-like receptor (TLR)4, peroxisome proliferator-activated receptor (PPAR)-γ, and interleukin (IL)-10 levels. Furthermore, TAS2R38 expression correlated negatively with TLR9 jejunal expression and IL-6 levels and positively with TLR4 levels. Our findings suggest that metabolic dysfunctions such as MetS trigger downregulation of the intestinal TASs. Therefore, taste receptors modulation could be a possible therapeutic target for metabolic disorders.

Circulating Levels of Pro-Neurotensin and Its Relationship with Nonalcoholic Steatohepatitis and Hepatic Lipid Metabolism.

Recent studies suggest a link between pro-neurotensin (pro-NT) and nonalcoholic fatty liver disease (NAFLD), but the published data are conflicting. Thus, we aimed to analyze pro-NT levels in women with morbid obesity (MO) and NAFLD to investigate if this molecule is involved in NAFLD and liver lipid metabolism. Plasma levels of pro-NT were determined in 56 subjects with MO and 18 with normal weight (NW). All patients with MO were subclassified according to their liver histology into the normal liver (NL, n = 20) and NAFLD (n = 36) groups. The NAFLD group had 17 subjects with simple steatosis (SS) and 19 with nonalcoholic steatohepatitis (NASH). We used a chemiluminescence sandwich immunoassay to quantify pro-NT in plasma and RT-qPCR to evaluate the hepatic mRNA levels of several lipid metabolism-related genes. We reported that pro-NT levels were significantly higher in MO with NAFLD than in MO without NAFLD. Additionally, pro-NT levels were higher in NASH patients than in NL. The hepatic expression of lipid metabolism-related genes was found to be altered in NAFLD, as previously reported. Additionally, although pro-NT levels correlated with LDL, there was no association with the main lipid metabolism-related genes. These findings suggest that pro-NT could be related to NAFLD progression.

Deregulation of Secreted Frizzled-Related Protein 5 in Nonalcoholic Fatty Liver Disease Associated with Obesity.

Secreted frizzled-related protein 5 (SFRP5), an antagonist of the noncanonical WNT pathway, has a controversial role in liver disease. The aim of this study was to analyze the role of SFRP5 and the noncanonical WNT pathway in nonalcoholic fatty liver disease (NAFLD). Plasma SFRP5 levels were determined by ELISA in women with normal weight (NW; n = 20) and morbid obesity (MO; n = 69). Women with MO were subclassified according to hepatic histology into normal liver (NL; n = 28), NAFLD (n = 41) (simple steatosis (SS; n = 24), and nonalcoholic steatohepatitis (NASH; n = 17)). We used RT-qPCR to evaluate the hepatic mRNA expression of SFRP5, WNT5A, and JNK in women with MO. SFRP5 levels were lower in NW than in MO patients who underwent a very low-calorie diet before surgery. Hepatic SFRP5 mRNA expression was higher in SS than in NL or NASH; additionally, patients with hepatic inflammation or ballooning presented lower SFRP5 abundance. WNT5A and JNK expression was enhanced in NAFLD compared with NL. In conclusion, circulating SFRP5 levels depend on the diet, and hepatic SFRP5 seems to have a protective role in the first steps of NAFLD; however, SFRP5 could be deregulated in an advanced stage while WNT5A and JNK are activated, promoting liver damage.

The Potential Protective Role of RUNX1 in Nonalcoholic Fatty Liver Disease.

The pathogenic mechanisms underlying nonalcoholic fatty liver disease (NAFLD) are beginning to be understood. RUNX1 is involved in angiogenesis, which is crucial in inflammation, but its role in nonalcoholic steatohepatitis (NASH) remains unclear. The aim of this study was to analyze RUNX1 mRNA hepatic and jejunal abundance in women with morbid obesity (MO) and NAFLD. RUNX1, lipid metabolism-related genes, and TLRs in women with MO and normal liver (NL, n = 28), NAFLD (n = 41) (simple steatosis (SS, n = 24), or NASH (n = 17)) were analyzed by RT-qPCR. The RUNX1 hepatic expression was higher in SS than in NL or NASH, as likewise confirmed by immunohistochemistry. An increased expression of hepatic FAS was found in NAFLD. Hepatic RUNX1 correlated positively with FAS. There were no significant differences in the jejunum RUNX1 expressions in the different groups. Jejunal FXR expression was lower in NASH than in NL, while the TLR9 expression increased as NAFLD progressed. Jejunal RUNX1 correlated positively with jejunal PPARγ, TLR4, and TLR5. In summary, the hepatic expression of RUNX1 seems to be involved in the first steps of the NAFLD process; however, in NASH, it seems to be downregulated. Our findings provide important insights into the role of RUNX1 in the context of NAFLD/NASH, suggesting a protective role.

Glutaminolysis-induced mTORC1 activation drives non-alcoholic steatohepatitis progression.

BACKGROUND & AIMS: A holistic insight on the relationship between obesity and metabolic dysfunction-associated fatty liver disease is an unmet clinical need. Omics investigations can be used to investigate the multifaceted role of altered mitochondrial pathways to promote nonalcoholic steatohepatitis, a major risk factor for liver disease-associated death. There are no specific treatments but remission via surgery might offer an opportunity to examine the signaling processes that govern the complex spectrum of chronic liver diseases observed in extreme obesity. We aim to assess the emerging relationship between metabolism, methylation and liver disease. METHODS: We tailed the flow of information, before and after steatohepatitis remission, from biochemical, histological, and multi-omics analyses in liver biopsies from patients with extreme obesity and successful bariatric surgery. Functional studies were performed in HepG2 cells and primary hepatocytes. RESULTS: The reversal of hepatic mitochondrial dysfunction and the control of oxidative stress and inflammatory responses revealed the regulatory role of mitogen-activated protein kinases. The reversible metabolic rearrangements leading to steatohepatitis increased the glutaminolysis-induced production of α-ketoglutarate and the hyperactivation of mammalian target of rapamycin complex 1. These changes were crucial for the adenosine monophosphate-activated protein kinase/mammalian target of rapamycin-driven pathways that modulated hepatocyte survival by coordinating apoptosis and autophagy. The signaling activity of α-ketoglutarate and the associated metabolites also affected methylation-related epigenomic remodeling enzymes. Integrative analysis of hepatic transcriptome signatures and differentially methylated genomic regions distinguished patients with and without steatohepatitis. CONCLUSION: We provide evidence supporting the multifaceted potential of the increased glutaminolysis-induced α-ketoglutarate production and the mammalian target of rapamycin complex 1 dysregulation as a conceivable source of the inefficient adaptive responses leading to steatohepatitis. LAY SUMMARY: Steatohepatitis is a frequent and threatening complication of extreme obesity without specific treatment. Omics technologies can be used to identify therapeutic targets. We highlight increased glutaminolysis-induced α-ketoglutarate production as a potential source of signals promoting and exacerbating steatohepatitis.

Nonalcoholic Steatohepatitis Modifies Serum Iron-Related Variables in Patients with Morbid Obesity.

Nonalcoholic steatohepatitis (NASH) is frequently associated with severe obesity. The liver is the principal storage repository for iron, and the excessive accumulation of this metal may promote hepatic inflammation. Laparoscopic sleeve gastrectomy (LSG) results in weight loss and improvement in comorbidities such as NASH. The aim of this study was to assess the specific NASH-related changes in iron metabolism and to investigate whether these changes are reversed by LSG. We included 150 patients with morbid obesity who provided 12-h fasting blood samples immediately before LSG together with an intraoperative wedge-liver biopsy. Thirty-eight patients with NASH underwent a second blood extraction 12 months postsurgery. Serum samples were collected from a control group comprising 50 healthy volunteers. We found significantly higher serum iron and transferrin concentrations in patients with NASH along with the highest degrees of steatosis, fibrosis, hepatocellular ballooning, and lobular inflammation. However, we did not find any significant accumulation of iron in the hepatic biopsies. Presurgery serum iron concentrations were lower in the patient group than in the control group and increased 1 year postsurgery. Serum ferritin levels showed changes in the opposite direction. We did not observe any significant change in serum transferrin concentrations. These changes were reversed by LSG. We conclude that alterations in serum iron-related variables are related to the severity of NASH in patients with morbid obesity, and these alterations are reversed by LSG. We also found that severe forms of NASH can be found in the absence of increased iron stores.

Laparoscopic sleeve gastrectomy alters 1H-NMR-measured lipoprotein and glycoprotein profile in patients with severe obesity and nonalcoholic fatty liver disease.

Patients with morbid obesity frequently present non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) associated with pro-atherogenic alterations. Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for weight reduction, and for the remission of hepatic alterations. Using 1H-nuclear magnetic resonance (1H-NMR), we investigated the effects of LSG on lipoprotein and glycoprotein profile in patients with morbid obesity and liver disease. We included 154 patients with morbid obesity (49 non-NASH, 54 uncertain NASH, 51 definite NASH). A blood sample was obtained before surgery and, in patients with definite NASH, one year after surgery. Patients with NASH had increased concentrations of medium and small VLDL particles, VLDL and IDL cholesterol concentrations, IDL, LDL, and HDL triglyceride concentrations, and elevated glycoprotein levels. These changes were more marked in patients with type 2 diabetes mellitus. LSG produced significant decreases in the concentration of VLDL particles, VLDL cholesterol and triglycerides, an increase in the concentration LDL particles and LDL cholesterol concentrations, and a decrease in protein glycation. We conclude that patients with obesity and NASH had significant alterations in circulating levels of lipoproteins and glycoproteins that were associated with the severity of the disease. Most of these changes were reversed post-LSG.