Plasma metabolic alterations in patients with severe obesity and non-alcoholic steatohepatitis

Pump-Less, Recirculating Organ-on-Chip (rOoC) Platform to Model the Metabolic Crosstalk between Islets and Liver

Type 2 diabetes mellitus (T2DM), obesity, and metabolic dysfunction-associated steatotic liver disease (MASLD) are epidemiologically correlated disorders with a worldwide growing prevalence. While the mechanisms leading to the onset and development of these conditions are not fully understood, predictive tissue representations for studying the coordinated interactions between central organs that regulate energy metabolism, particularly the liver and pancreatic islets, are needed. Here, a dual pump-less recirculating organ-on-chip platform that combines human pluripotent stem cell (sc)-derived sc-liver and sc-islet organoids is presented. The platform reproduces key aspects of the metabolic cross-talk between both organs, including glucose levels and selected hormones, and supports the viability and functionality of both sc-islet and sc-liver organoids while preserving a reduced release of pro-inflammatory cytokines. In a model of metabolic disruption in response to treatment with high lipids and fructose, sc-liver organoids exhibit hallmarks of steatosis and insulin resistance, while sc-islets produce pro-inflammatory cytokines on-chip. Finally, the platform reproduces known effects of anti-diabetic drugs on-chip. Taken together, the platform provides a basis for functional studies of obesity, T2DM, and MASLD on-chip, as well as for testing potential therapeutic interventions.

Metabolic adaptations in severe obesity: Insights from circulating oxylipins before and after weight loss

BACKGROUND

The relationship between lipid mediators and severe obesity remains unclear. Our study investigates the impact of severe obesity on plasma concentrations of oxylipins and fatty acids and explores the consequences of weight loss.

METHODS

In the clinical trial identifier NCT05554224 study, 116 patients with severe obesity and 63 overweight/obese healthy controls matched for age and sex (≈2:1) provided plasma. To assess the effect of surgically induced weight loss, we requested paired plasma samples from 44 patients undergoing laparoscopic sleeve gastrectomy one year after the procedure. Oxylipins were measured using ultra-high-pressure liquid chromatography coupled to a triple quadrupole mass spectrometer via semi-targeted lipidomics. Cytokines and markers of interorgan crosstalk were measured using enzyme-linked immunosorbent assays.

RESULTS

We observed significantly elevated levels of circulating fatty acids and oxylipins in patients with severe obesity compared to their metabolically healthier overweight/obese counterparts. Our findings indicated that sex and liver disease were not confounding factors, but we observed weak correlations in plasma with circulating adipokines, suggesting the influence of adipose tissue. Importantly, while weight loss restored the balance in circulating fatty acids, it did not fully normalize the oxylipin profile. Before surgery, oxylipins derived from lipoxygenase activity, such as 12-HETE, 11-HDoHE, 14-HDoHE, and 12-HEPE, were predominant. However, one year following laparoscopic sleeve gastrectomy, we observed a complex shift in the oxylipin profile, favoring species from the cyclooxygenase pathway, particularly proinflammatory prostanoids like TXB2, PGE2, PGD2, and 12-HHTrE. This transformation appears to be linked to a reduction in adiposity, underscoring the role of lipid turnover in the development of metabolic disorders associated with severe obesity.

CONCLUSIONS

Despite the reduction in fatty acid levels associated with weight loss, the oxylipin profile shifts towards a predominance of more proinflammatory species. These observations underscore the significance of seeking mechanistic approaches to address severe obesity and emphasize the importance of closely monitoring the metabolic adaptations after weight loss.

Metabolomics and mitochondrial dysfunction in cardiometabolic disease

Circulating metabolites are indicators of systemic metabolic dysfunction and can be detected through contemporary techniques in metabolomics. These metabolites are involved in numerous mitochondrial metabolic processes including glycolysis, fatty acid β-oxidation, and amino acid catabolism, and changes in the abundance of these metabolites is implicated in the pathogenesis of cardiometabolic diseases (CMDs). Epigenetic regulation and direct metabolite-protein interactions modulate metabolism, both within cells and in the circulation. Dysfunction of multiple mitochondrial components stemming from mitochondrial DNA mutations are implicated in disease pathogenesis. This review will summarize the current state of knowledge regarding: i) the interactions between metabolites found within the mitochondrial environment during CMDs, ii) various metabolites' effects on cellular and systemic function, iii) how harnessing the power of metabolomic analyses represents the next frontier of precision medicine, and iv) how these concepts integrate to expand the clinical potential for translational cardiometabolic medicine.

β-hydroxybutyrate: A crucial therapeutic target for diverse liver diseases

β-hydroxybutyrate (β-HB), the most abundant ketone body, is produced primarily in the liver and acts as a substitute energy fuel to provide energy to extrahepatic tissues in the event of hypoglycemia or glycogen depletion. We now have an improved understanding of β-HB as a signal molecule and epigenetic regulatory factor as a result of intensive research over the last ten years. Because β-HB regulates various physiological and pathological processes, it may have a potential role in the treatment of metabolic diseases. The liver is the most significant metabolic organ, and the part that β-HB plays in liver disorders is receiving increasing attention. In this review, we summarize the therapeutic effects of β-HB on liver diseases and its underlying mechanisms of action. Moreover, we explore the prospects of exogenous supplements and endogenous ketosis including fasting, caloric restriction (CR), ketogenic diet (KD), and exercise as adjuvant nutritional therapies to protect the liver from damage and provide insights and strategies for exploring the treatment of various liver diseases.

Paraoxonase-1: How a xenobiotic detoxifying enzyme has become an actor in the pathophysiology of infectious diseases and cancer

Both infectious and non-infectious diseases can share common molecular mechanisms, including oxidative stress and inflammation. External factors, such as bacterial or viral infections, excessive calorie intake, inadequate nutrients, or environmental factors, can cause metabolic disorders, resulting in an imbalance between free radical production and natural antioxidant systems. These factors may lead to the production of free radicals that can oxidize lipids, proteins, and nucleic acids, causing metabolic alterations that influence the pathogenesis of the disease. The relationship between oxidation and inflammation is crucial, as they both contribute to the development of cellular pathology. Paraoxonase 1 (PON1) is a vital enzyme in regulating these processes. PON1 is an enzyme that is bound to high-density lipoproteins and protects the organism against oxidative stress and toxic substances. It breaks down lipid peroxides in lipoproteins and cells, enhances the protection of high-density lipoproteins against different infectious agents, and is a critical component of the innate immune system. Impaired PON1 function can affect cellular homeostasis pathways and cause metabolically driven chronic inflammatory states. Therefore, understanding these relationships can help to improve treatments and identify new therapeutic targets. This review also examines the advantages and disadvantages of measuring serum PON1 levels in clinical settings, providing insight into the potential clinical use of this enzyme.

Changes of gut microbiota and tricarboxylic acid metabolites may be helpful in early diagnosis of necrotizing enterocolitis: A pilot study

Purpose

We aimed to explore the value of gut microbiota and tricarboxylic acid (TCA) metabolites in early diagnosis of necrotizing enterocolitis (NEC) among infants with abdominal manifestations.

Methods

Thirty-two preterm infants with abdominal manifestations at gestational age ≤ 34 weeks were included in the study and were divided into non-NEC (n = 16) and NEC (n = 16) groups. Faecal samples were collected when the infants were enrolled. The gut microbiota was analysed with high-throughput sequencing, and TCA metabolites were measured with multiple reaction monitoring (MRM) targeted metabolomics. Receiver operating characteristic (ROC) curves were generated to explore the predictive value of the obtained data.

Results

There was no significant difference in alpha diversity or beta diversity between the two groups (p > 0.05). At the phylum level, Proteobacteria increased, and Actinomycetota decreased in the NEC group (p < 0.05). At the genus level, Bifidobacterium and Lactobacillaceae decreased significantly, and at the species level, unclassified Staphylococcus, Lactobacillaceae and Bifidobacterium animalis subsp. lactis decreased in the NEC group (p < 0.05). Further Linear discriminant analysis effect sizes (LEfSe) analysis showed that the change in Proteobacteria at the phylum level and Lactobacillaceae and Bifidobacterium at the genus level scored higher than 4. The concentrations of succinate, L-malic acid and oxaloacetate in the NEC group significantly increased (p < 0.05), and the areas under the ROC curve for these metabolites were 0.6641, 0.7617, and 0.7344, respectively.

Conclusion

Decreased unclassified Staphylococcus, Lactobacillaceae and Bifidobacterium animalis subsp. lactis at the species level as well as the increase in the contents of some TCA metabolites, including succinate, L-malic acid and oxaloacetate, have potential value for the early diagnosis of NEC.

Integration of transcriptomics and metabonomics revealed the protective effects of hemp seed oil against methionine-choline-deficient diet-induced non-alcoholic steatohepatitis in mice

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease with few therapeutic options available currently. Hemp seed oil extracted from the seeds of hemp (Cannabis sativa L.) has significant nutritional and biological properties due to the unique composition of polyunsaturated fatty acids and various antioxidant compounds. However, little is known about the beneficial effects and molecular mechanisms of hemp seed oil on NASH. Here, the hepatoprotective effects of hemp seed oil on methionine-choline-deficient (MCD) diet-induced NASH in C57BL/6 mice were explored via integration of transcriptomics and metabolomics. Hemp seed oil could improve hepatic steatosis, inflammation and fibrosis in mice with MCD diet-induced NASH. In a nuclear magnetic resonance (NMR)-based metabonomic study, the hepatic and urinary metabolic profiles of mice supplemented with hemp seed oil showed a tendency to recover to healthy controls compared to those of NASH mice. Eight potential biomarkers associated with NASH in both liver tissue and urine were restored to near normal levels by administration of hemp seed oil. The proposed pathways were mainly involved in pyrimidine metabolism, one-carbon metabolism, amino acid metabolism, glycolysis and the tricarboxylic acid (TCA) cycle. Hepatic transcriptomics based on Illumina RNA-Seq sequencing showed that hemp seed oil exerted anti-NASH activities by regulating multiple signaling pathways, e.g., downregulation of the TNF signaling pathway, the IL-17 signaling pathway, the MAPK signaling pathway and the NF-κB signaling pathway, which played a pivotal role in the pathogenesis of NASH. In particular, integration of metabonomic and transcriptomic results suggested that hemp seed oil could attenuate NASH-related liver fibrosis by inhibition of glutaminolysis. These results provided new insights into the hepatoprotective effects of hemp seed oil against MCD diet-induced NASH and hemp seed oil might have potential as an effective therapy for NASH.

Accurate liquid biopsy for the diagnosis of non-alcoholic steatohepatitis and liver fibrosis

OBJECTIVE

Clinical diagnosis and approval of new medications for non-alcoholic steatohepatitis (NASH) require invasive liver biopsies. The aim of our study was to identify non-invasive biomarkers of NASH and/or liver fibrosis.

DESIGN

This multicentre study includes 250 patients (discovery cohort, n=100 subjects (Bariatric Surgery Versus Non-alcoholic Steato-hepatitis - BRAVES trial); validation cohort, n=150 (Liquid Biopsy for NASH and Liver Fibrosis - LIBRA trial)) with histologically proven non-alcoholic fatty liver (NAFL) or NASH with or without fibrosis. Proteomics was performed in monocytes and hepatic stellate cells (HSCs) with iTRAQ-nano- Liquid Chromatography - Mass Spectrometry/Mass Spectrometry (LC-MS/MS), while flow cytometry measured perilipin-2 (PLIN2) and RAB14 in peripheral blood CD14⁺CD16^- monocytes. Neural network classifiers were used to predict presence/absence of NASH and NASH stages. Logistic bootstrap-based regression was used to measure the accuracy of predicting liver fibrosis.

RESULTS

The algorithm for NASH using PLIN2 mean florescence intensity (MFI) combined with waist circumference, triglyceride, alanine aminotransferase (ALT) and presence/absence of diabetes as covariates had an accuracy of 93% in the discovery cohort and of 92% in the validation cohort. Sensitivity and specificity were 95% and 90% in the discovery cohort and 88% and 100% in the validation cohort, respectively.The area under the receiver operating characteristic (AUROC) for NAS level prediction ranged from 83.7% (CI 75.6% to 91.8%) in the discovery cohort to 97.8% (CI 95.8% to 99.8%) in the validation cohort.The algorithm including RAB14 MFI, age, waist circumference, high-density lipoprotein cholesterol, plasma glucose and ALT levels as covariates to predict the presence of liver fibrosis yielded an AUROC of 95.9% (CI 87.9% to 100%) in the discovery cohort and 99.3% (CI 98.1% to 100%) in the validation cohort, respectively. Accuracy was 99.25%, sensitivity 100% and specificity 95.8% in the discovery cohort and 97.6%, 99% and 89.6% in the validation cohort. This novel biomarker was superior to currently used FIB4, non-alcoholic fatty liver disease fibrosis score and aspartate aminotransferase (AST)-to-platelet ratio and was comparable to ultrasound two-dimensional shear wave elastography.

CONCLUSIONS

The proposed novel liquid biopsy is accurate, sensitive and specific in diagnosing the presence and severity of NASH or liver fibrosis and is more reliable than currently used biomarkers.

CLINICAL TRIALS

Discovery multicentre cohort: Bariatric Surgery versus Non-Alcoholic Steatohepatitis, BRAVES, ClinicalTrials.gov identifier: NCT03524365.Validation multicentre cohort: Liquid Biopsy for NASH and Fibrosis, LIBRA, ClinicalTrials.gov identifier: NCT04677101.

Optimization of a GC-MS Injection-Port Derivatization Methodology to Enhance Metabolomics Analysis Throughput in Biological Samples

Advances in metabolomics analysis and data treatment increase the knowledge of complex biological systems. One of the most used methodologies is gas chromatography-mass spectrometry (GC-MS) due to its robustness, high separation efficiency, and reliable peak identification through curated databases. However, methodologies are not standardized, and the derivatization steps in GC-MS can introduce experimental errors and take considerable time, exposing the samples to degradation. Here, we propose the injection-port derivatization (IPD) methodology to increase the throughput in plasma metabolomics analysis by GC-MS. The IPD method was evaluated and optimized for different families of metabolites (organic acids, amino acids, fatty acids, sugars, sugar phosphates, etc.) in terms of residence time, injection-port temperature, and sample/derivatization reagent ratio. Finally, the method's usefulness was validated in a study consisting of a cohort of obese patients with or without nonalcoholic steatohepatitis. Our results show a fast, reproducible, precise, and reliable method for the analysis of biological samples by GC-MS. Raw data are publicly available at MetaboLights with Study Identifier MTBLS5151.

The contribution of the gut-liver axis to the immune signaling pathway of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the liver manifestation of metabolic syndrome and is the most common chronic liver disease in the world. The pathogenesis of NAFLD has not been fully clarified; it involves metabolic disturbances, inflammation, oxidative stress, and various forms of cell death. The “intestinal-liver axis” theory, developed in recent years, holds that there is a certain relationship between liver disease and the intestinal tract, and changes in intestinal flora are closely involved in the development of NAFLD. Many studies have found that the intestinal flora regulates the pathogenesis of NAFLD by affecting energy metabolism, inducing endotoxemia, producing endogenous ethanol, and regulating bile acid and choline metabolism. In this review, we highlighted the updated discoveries in intestinal flora dysregulation and their link to the pathogenesis mechanism of NAFLD and summarized potential treatments of NAFLD related to the gut microbiome.

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.

An MMP-degraded and cross-linked fragment of type III collagen as a non-invasive biomarker of hepatic fibrosis resolution

BACKGROUND AND AIMS

Liver fibrosis results from a prolonged wound healing response to continued injury with excessive production of extracellular proteins. In patients with chronic liver disease, the monitoring of liver fibrosis dynamics is of high interest. Whilst markers of fibrogenesis exist, markers of hepatic fibrosis resolution remain an unmet clinical need. Thus, we sought to develop an assay quantifying a circulating proteolytic fragment of cross-linked type III collagen as a biomarker of fibrolysis, testing its utility in two clinical cohorts of liver fibrosis of distinct aetiology and regressing endotype METHODS: We used a monoclonal antibody targeting the C-telopeptide of type III collagen following C-proteinase cleavage to develop and validate a neo-epitope-specific enzyme-linked immunosorbent assay (CTX-III). A potential fibrosis resolution marker, CTX-III, was measured in two clinical cohorts of patients with obesity-associated non-alcoholic fatty liver disease undergoing bariatric surgery or hepatitis C virus infection from a clinical trial study evaluating the anti-fibrotic effect of farglitazar.

RESULTS

CTX-III was robust and specific for the targeted neo-epitope with good reproducibility in EDTA plasma. We assessed type III collagen remodelling using a panel of biomarkers, including a type III collagen formation marker (PRO-C3), degradation (C3M), and CTX-III (fibrolysis). Net fibrolysis was increased in patients with non-alcoholic fatty liver disease following bariatric surgery (p < .001). Moreover, net fibrolysis identified spontaneous fibrotic regressors from stable and progressors (p < .05 and p < .001) among hepatitis C virus infection patients.

CONCLUSION

Circulating CTX-III as a marker of fibrolysis indicates the biomarker's beneficial use in assessing hepatic fibrosis resolution.

Metabolomic signatures after bariatric surgery - a systematic review

Metabolomics emerged as an important tool to gain insights on how the body responds to therapeutic interventions. Bariatric surgery is the most effective treatment for severe obesity and obesity-related co-morbidities. Our aim was to conduct a systematic review of the available data on metabolomics profiles that characterize patients submitted to different bariatric surgery procedures, which could be useful to predict clinical outcomes including weight loss and type 2 diabetes remission. For that, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA guidelines were followed. Data from forty-seven original study reports addressing metabolomics profiles induced by bariatric surgery that met eligibility criteria were compiled and summarized. Amino acids, lipids, energy-related and gut microbiota-related were the metabolite classes most influenced by bariatric surgery. Among these, higher pre-operative levels of specific lipids including phospholipids, long-chain fatty acids and bile acids were associated with post-operative T2D remission. As conclusion, metabolite profiling could become a useful tool to predict long term response to different bariatric surgery procedures, allowing more personalized interventions and improved healthcare resources allocation.

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.

Folic acid oversupplementation during pregnancy disorders lipid metabolism in male offspring via regulating arginase 1-associated NOS3-AMPKα pathway

BACKGROUND & AIMS

Folic acid supplementation is widely accepted during pregnancy, as it exerts a protective effect on neural tube defects. However, the long-term underlying effects of folic acid supplementation during pregnancy (FASDP) on offspring remain unclear.

METHODS

Thirty pregnant female rats were randomly divided into normal control group, folic acid appropriate supplementation group (2.5 × FA group) and folic acid oversupplementation group (5 × FA group) and fed with corresponding folic acid concentration AIN93G diet. UPLC-Q-TOF-MS, UPLC-TQ-MS and GC-MS were performed to detect the serum metabolites profiles in adult male offspring and explore the effects of FASDP. Moreover, molecular biology technologies were used to clarify the underlying mechanism.

RESULTS

We demonstrate that 2.5-folds folic acid leads to dyslipidemic-diabetic slightly in male offspring, while 5-folds folic acid aggravates the disorder and prominent hepatic lipid accumulations. Using untargeted and targeted metabolomics, total 63 differential metabolites and 12 significantly differential KEGG pathways are identified. Of note, arginine biosynthesis, arginine and proline metabolism are the two most significant pathways. Mechanistic investigations reveal that the increased levels of arginase-1 (Arg1) causes the lipid metabolism disorder by regulating nitric oxide synthase-3 (NOS3)-adenosine monophosphate activated protein kinase-α (AMPKα) pathway, resulting in lipid accumulation in hepatocytes.

CONCLUSIONS

Our data suggest that maternal folic acid oversupplementation during pregnancy contributes to lipid metabolism disorder in male offspring by regulating Arg1-NOS3-AMPKα pathway.

On the Role of Paraoxonase-1 and Chemokine Ligand 2 (C-C motif) in Metabolic Alterations Linked to Inflammation and Disease. A 2021 Update

Infectious and many non-infectious diseases share common molecular mechanisms. Among them, oxidative stress and the subsequent inflammatory reaction are of particular note. Metabolic disorders induced by external agents, be they bacterial or viral pathogens, excessive calorie intake, poor-quality nutrients, or environmental factors produce an imbalance between the production of free radicals and endogenous antioxidant systems; the consequence being the oxidation of lipids, proteins, and nucleic acids. Oxidation and inflammation are closely related, and whether oxidative stress and inflammation represent the causes or consequences of cellular pathology, both produce metabolic alterations that influence the pathogenesis of the disease. In this review, we highlight two key molecules in the regulation of these processes: Paraoxonase-1 (PON1) and chemokine (C-C motif) ligand 2 (CCL2). PON1 is an enzyme bound to high-density lipoproteins. It breaks down lipid peroxides in lipoproteins and cells, participates in the protection conferred by HDL against different infectious agents, and is considered part of the innate immune system. With PON1 deficiency, CCL2 production increases, inducing migration and infiltration of immune cells in target tissues and disturbing normal metabolic function. This disruption involves pathways controlling cellular homeostasis as well as metabolically-driven chronic inflammatory states. Hence, an understanding of these relationships would help improve treatments and, as well, identify new therapeutic targets.

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.

Therapeutic potential of puerarin against methionine-choline-deficient diet-induced non-alcoholic steatohepatitis determined by combination of 1H NMR spectroscopy-based metabonomics and 16S rRNA gene sequencing

Previously published studies have revealed the protective effect of puerarin against non-alcoholic steatohepatitis (NASH), but the definite mechanism of this effect still remains unclear. The present work was an attempt to assess the beneficial effects and the underlying mechanisms of puerarin on methionine-choline-deficient (MCD) diet-induced NASH in C57BL/6 mice by using a combination of metabonomics and 16S rRNA gene sequencing technology. Nuclear magnetic resonance (NMR)-based metabonomics showed significant hepatic and urinary metabolic phenotype changes between MCD-diet fed mice and the healthy controls. A total of eight and thirteen metabolites were identified as differential metabolites associated with NASH in liver tissue and urine of mice, respectively. The proposed pathways mainly included pyrimidine metabolism, one-carbon metabolism, amino acid metabolism, glycolysis, tricarboxylic acid (TCA) cycle and synthesis and degradation of ketone bodies. Furthermore, 16S rRNA gene sequencing analysis delineated remarkable variations in gut microbiota profiles in response to MCD diet in mice and forty differential bacterial taxa related to NASH were found between the control and model group. Puerarin could improve hepatic steatosis and inflammation in NASH mice via partially ameliorating metabolic disorders and rebalancing the gut flora. Specifically, puerarin could inhibit lipopolysaccharide (LPS)-producing genus Helicobacter, and promote butyrate-producing genus Roseburia. These findings offered novel insights into the in-depth understanding of the pathogenesis of NASH and provided further evidence for the potential use of puerarin as an anti-NASH agent.

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.

Effectiveness comparisons of catgut implantation at acupoint for obese type 2 diabetes: A protocol for systematic review and meta analysis

BACKGROUND

With the change of people's life style, many more people are suffering from obese type 2 diabetes mellitus (T2DM). Acupoint catgut embedding is one of the acupuncture treatment principles in traditional Chinese medicine, which is widely used in the treatment of obese T2DM. However, there is no systematic review of the therapeutic effect of acupoint catgut embedding on obesity T2DM. Therefore, this article aims at the meta-analysis of acupoint catgut embedding in the treatment of obese T2DM, to clarify its curative effect.

METHODS

A structured and systemic literature search was conducted in the following databases up to December 1, 2019: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, EMBASE, CNKI, Wanfang Database. We will use the Review Manager 5.3 software provided by Cochrane collaborative network for statistical analysis. Then we assessed the quality and risk of the included studies and observed the outcome measures.

RESULTS

This meta-analysis will further determine the beneficial efficacy of acupoint catgut embedding on obesity T2DM.

CONCLUSION

The purpose of this meta-analysis is to explore the effect of acupoint catgut embedding intervention on obese T2DM patients, and provide more options for clinicians and patients to treat obese T2DM.

ETHICS AND DISSEMINATION

This systemic review will evaluate the efficacy and safety of acupoint catgut embedding in the treatment of obesity T2DM. Since all the data included are published, the systematic review does not need ethical approval.

REGISTRATION NUMBER

CRD42020160801.