Obesity, diabetes mellitus, and liver fibrosis

Shear wave elastography to assess stiffness of the human ovary and other reproductive tissues across the reproductive lifespan in health and disease†

The ovary is one of the first organs to show overt signs of aging in the human body, and ovarian aging is associated with a loss of gamete quality and quantity. The age-dependent decline in ovarian function contributes to infertility and an altered endocrine milieu, which has ramifications for overall health. The aging ovarian microenvironment becomes fibro-inflammatory and stiff with age, and this has implications for ovarian physiology and pathology, including follicle growth, gamete quality, ovulation dynamics, and ovarian cancer. Thus, developing a non-invasive tool to measure and monitor the stiffness of the human ovary would represent a major advance for female reproductive health and longevity. Shear wave elastography is a quantitative ultrasound imaging method for evaluation of soft tissue stiffness. Shear wave elastography has been used clinically in assessment of liver fibrosis and characterization of tendinopathies and various neoplasms in thyroid, breast, prostate, and lymph nodes as a non-invasive diagnostic and prognostic tool. In this study, we review the underlying principles of shear wave elastography and its current clinical uses outside the reproductive tract as well as its successful application of shear wave elastography to reproductive tissues, including the uterus and cervix. We also describe an emerging use of this technology in evaluation of human ovarian stiffness via transvaginal ultrasound. Establishing ovarian stiffness as a clinical biomarker of ovarian aging may have implications for predicting the ovarian reserve and outcomes of Assisted Reproductive Technologies as well as for the assessment of the efficacy of emerging therapeutics to extend reproductive longevity. This parameter may also have broad relevance in other conditions where ovarian stiffness and fibrosis may be implicated, such as polycystic ovarian syndrome, late off target effects of chemotherapy and radiation, premature ovarian insufficiency, conditions of differences of sexual development, and ovarian cancer. Summary sentence:  Shear Wave Elastography is a non-invasive technique to study human tissue stiffness, and here we review its clinical applications and implications for reproductive health and disease.

Liver fibrosis pathologies and potentials of RNA based therapeutics modalities

Liver fibrosis (LF) occurs when the liver tissue responds to injury or inflammation by producing excessive amounts of scar tissue, known as the extracellular matrix. This buildup stiffens the liver tissue, hinders blood flow, and ultimately impairs liver function. Various factors can trigger this process, including bloodborne pathogens, genetic predisposition, alcohol abuse, non-steroidal anti-inflammatory drugs, non-alcoholic steatohepatitis, and non-alcoholic fatty liver disease. While some existing small-molecule therapies offer limited benefits, there is a pressing need for more effective treatments that can truly cure LF. RNA therapeutics have emerged as a promising approach, as they can potentially downregulate cytokine levels in cells responsible for liver fibrosis. Researchers are actively exploring various RNA-based therapeutics, such as mRNA, siRNA, miRNA, lncRNA, and oligonucleotides, to assess their efficacy in animal models. Furthermore, targeted drug delivery systems hold immense potential in this field. By utilizing lipid nanoparticles, exosomes, nanocomplexes, micelles, and polymeric nanoparticles, researchers aim to deliver therapeutic agents directly to specific biomarkers or cytokines within the fibrotic liver, increasing their effectiveness and reducing side effects. In conclusion, this review highlights the complex nature of liver fibrosis, its underlying causes, and the promising potential of RNA-based therapeutics and targeted delivery systems. Continued research in these areas could lead to the development of more effective and personalized treatment options for LF patients.

Genetic Investigation of the Trail Mechanism in Diabetic and Non-diabetic Obese Patients

Obesity is an important healthcare issue caused by abnormally increased adipose tissue because of energy-intake overcoming energy expenditure. Disturbances in the physiological function of adipose tissue mediate the development of diabetes. It is a metabolic disease that results from decreased insulin-levels and/or changes in the insulin action mechanism. Tumor Necrosis Factor-Associated Apoptosis-Inducing Ligand(TRAIL), which is a member of the Tumor Necrosis Factor(TNF)-family with an important role in adipose tissue biology, is included in many studies with its ability to induce apoptosis in cancer cells, but the number of human-studies conducted on the gene related to its protective-role against diabetes and obesity at this level is insufficient. Our study was carried out as a case and control and included three groups (80 diabetic obese, 80 non-diabetic obese, and 80 healthy individuals as the control group). The Real-Time-PZR(RT-qPZR), and DNA Sanger-Sequencing Methods were used for gene expression and gene squences. As a result of the analyses, TRAIL gene expression level was found to be higher in the controls than in the diabetic-obese and non-diabetic-obese group. This change in TRAIL gene expression suggests that TRAIL maybe a protective factor against diabetes. The presence of rs781673405, rs143353036, rs1244378045, rs767450259, rs759369504, rs750556128, and rs369143448 mutations, which was determined with the Sequencing-Method, was shown for the first time in the present study. In addition, it is the first study in which human TRAIL gene-expression and sequencing were performed together. We believe that these data will make an important contribution to the literature.

Prevalence and Crucial Parameters in Diabesity-Related Liver Fibrosis: A Preliminary Study

Diabetes and obesity have been recognized as confirmed risk factors for the occurrence of liver fibrosis. Despite the long-standing acknowledgment of "diabesity", the simultaneous existence of diabetes and obesity, scholarly literature has shown limited attention to this topic. The aim of this pilot study was to assess the prevalence of liver fibrosis among individuals with diabetes (specifically those who are obese) in order to identify the key factors associated with hepatofibrosis and determine the most important associations and differences between patients with and without liver fibrosis. The research included a total of 164 participants (48.17% had comorbid obesity). Liver elastography (Fibroscan) was performed on these individuals in addition to laboratory tests. Liver fibrosis was found in 34.76% of type 2 diabetes patients; male gender almost doubled the risk of hepatofibrosis (RR 1.81) and diabesity nearly tripled this risk (RR 2.81; however, in degree III of obesity, the risk was elevated to 3.65 times higher). Anisocytosis, thrombocytopenia, or elevated liver enzymes raised the incidence of liver fibrosis by 1.78 to 2.47 times. In these individuals, liver stiffness was negatively correlated with MCV, platelet count, and albumin concentration; GGTP activity and HbA1c percentage were positively correlated. The regression analysis results suggest that the concentration of albumin and the activity of GGTP are likely to have a substantial influence on the future management of liver fibrosis in patients with diabesity. The findings of this study can serve as the basis for subsequent investigations and actions focused on identifying potential therapeutic and diagnostic avenues.

Diabetic MAFLD is associated with increased risk of hepatocellular carcinoma and mortality in chronic viral hepatitis patients

Metabolic dysfunction-associated fatty liver disease (MAFLD) can coexist with chronic viral hepatitis. MAFLD is a heterogeneous disease because the diagnostic criteria include various metabolic traits. We aimed to identify patients at high risk of poor long-term outcomes based on MAFLD subgroups in chronic viral hepatitis patients. We evaluated 63 273 chronic hepatitis B and C patients. Patient with a fatty liver index ≥30 was defined to have hepatic steatosis. MAFLD was defined as the presence of hepatic steatosis with any one of the following three conditions, overweight/obesity, type 2 diabetes or ≥2 metabolic risk factors. The prevalence of MAFLD was 38.4% (n = 24 290). During a median 8.8-year follow-up, 1839 HCCs and 2258 deaths were documented in MAFLD patients. Among MAFLD patients, diabetes could identify patients at high risk of HCC and mortality, whereas overweight/obesity and metabolic risk factors did not. Compared with non-MAFLD patients, risk of HCC and mortality was significantly higher in diabetic MAFLD patients (adjusted hazard ratio [aHR] = 1.34, 95% confidence interval [CI] = 1.26-1.43 for HCC; aHR = 1.15, 95% CI = 1.08-1.22 for mortality). Risk of HCC and mortality was significantly higher in diabetic MAFLD patients (aHR = 1.40, 95% CI = 1.26-1.55 for HCC; aHR = 1.77, 95% CI = 1.63-1.93 for mortality) compared with non-diabetic MAFLD patients. Diabetic MAFLD is associated with increased risk of HCC and mortality among chronic viral hepatitis patients. Our findings highlight the need for close surveillance and effective treatment for these high-risk patients to reduce HCC and mortality in patients with chronic viral hepatitis.

Hepatic stellate cell-intrinsic role of SOCS1 in controlling hepatic fibrogenic response and the pro-inflammatory macrophage compartment during liver fibrosis

Introduction

Hepatic stellate cells (HSC) become activated, differentiate to myofibroblasts and produce extracellular fibrillar matrix during liver fibrosis. The hepatic fibrogenic response is orchestrated by reciprocal interactions between HSCs and macrophages and their secreted products. SOCS1 can regulate several cytokines and growth factors implicated in liver fibrosis. Here we investigated the role of SOCS1 in regulating HSC activation.

Methods

Mice lacking SOCS1 in HSCs (Socs1ΔHSC) were generated by crossing Socs1fl/fl and LratCre mice. Liver fibrosis was induced by carbon tetrachloride and evaluated by Sirius red staining, hydroxyproline content and immunostaining of myofibroblasts. Gene expression of pro-fibrogenic factors, cytokines, growth factors and chemokines were quantified by RT-qPCR. The phenotype and the numbers of intrahepatic leukocyte subsets were studied by flow cytometry. The impact of fibrosis on the development of diethyl nitrosamine-induced hepatocellular carcinoma was evaluated.

Results

Socs1ΔHSC mice developed more severe liver fibrosis than control Socs1fl/fl mice that was characterized by increased collagen deposition and myofibroblast differentiation. Socs1ΔHSC mice showed a significant increase in the expression of smooth muscle actin, collagens, matrix metalloproteases, cytokines, growth factors and chemokines in the liver following fibrosis induction. The fibrotic livers of Socs1ΔHSC mice displayed heightened inflammatory cell infiltration with increased proportion and numbers of Ly6ChiCCR2+ pro-inflammatory macrophages. This macrophage population contained elevated numbers of CCR2+CX3CR1+ cells, suggesting impaired transition towards restorative macrophages. Fibrosis induction following exposure to diethyl nitrosamine resulted in more numerous and larger liver tumor nodules in Socs1ΔHSC mice than in Socs1fl/fl mice.

Discussion

Our findings indicate that (i) SOCS1 expression in HSCs is a critical to control liver fibrosis and development of hepatocaellular carcinoma, and (ii) attenuation of HSC activation by SOCS1 regulates pro-inflammatory macrophage recruitment and differentiation during liver fibrosis.

Lobeglitazone inhibits LPS-induced NLRP3 inflammasome activation and inflammation in the liver

Liver inflammation is a common feature of chronic liver disease and is often associated with increased exposure of the liver to lipopolysaccharide (LPS). Kupffer cells (KCs) are macrophages in the liver and produce various cytokines. Activation of KCs through the NLRP3 inflammasome pathway leads to release of proinflammatory cytokines and induces hepatocyte injury and hepatic stellate cell (HSC) activation. Lobeglitazone is a peroxisome proliferator-activated receptor gamma ligand and a type of thiazolidinedione that elicits anti-inflammatory effects. However, there is no clear evidence that it has direct anti-inflammatory effects in the liver. This study showed that lobeglitazone reduces LPS-induced NLPR3 inflammasome activation and production of proinflammatory cytokines in primary KCs and hepatocytes. Cytokines secreted by activated KCs increased hepatocyte inflammation and HSC activation, and lobeglitazone inhibited these responses. In addition, lobeglitazone suppressed liver fibrosis by inhibiting LPS-induced transforming growth factor (TGF)-β secretion and TGF-β-induced CTGF expression. The inhibitory effect of lobeglitazone on inflammasome activation was associated with suppression of liver fibrosis. These results suggest that lobeglitazone may be a treatment option for inflammation and fibrosis in the liver.

Extracellular matrix remodelling in obesity and metabolic disorders

Obesity causes extracellular matrix (ECM) remodelling which can develop into serious pathology and fibrosis, having metabolic effects in insulin-sensitive tissues. The ECM components may be increased in response to overnutrition. This review will focus on specific obesity-associated molecular and pathophysiological mechanisms of ECM remodelling and the impact of specific interactions on tissue metabolism. In obesity, complex network of signalling molecules such as cytokines and growth factors have been implicated in fibrosis. Increased ECM deposition contributes to the pathogenesis of insulin resistance at least in part through activation of cell surface integrin receptors and CD44 signalling cascades. These cell surface receptors transmit signals to the cell adhesome which orchestrates an intracellular response that adapts to the extracellular environment. Matrix proteins, glycoproteins, and polysaccharides interact through ligand-specific cell surface receptors that interact with the cytosolic adhesion proteins to elicit specific actions. Cell adhesion proteins may have catalytic activity or serve as scaffolds. The vast number of cell surface receptors and the complexity of the cell adhesome have made study of their roles challenging in health and disease. Further complicating the role of ECM-cell receptor interactions is the variation between cell types. This review will focus on recent insights gained from studies of two highly conserved, ubiquitously axes and how they contribute to insulin resistance and metabolic dysfunction in obesity. These are the collagen-integrin receptor-IPP (ILK-PINCH-Parvin) axis and the hyaluronan-CD44 interaction. We speculate that targeting ECM components or their receptor-mediated cell signalling may provide novel insights into the treatment of obesity-associated cardiometabolic complications.

Comparing the effectiveness of long-term use of daily and weekly glucagon-like peptide-1 receptor agonists treatments in patients with nonalcoholic fatty liver disease and type 2 diabetes mellitus: a network meta-analysis

Objective

In the present network meta-analysis (NMA), we aimed to compare the effectiveness of daily and weekly treatment with glucagon-like peptide-1 receptor agonists for patients with nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM).

Method

We used Stata 17.0 for the NMA. Eligible Randomized controlled trials (RCTs) were searched in PubMed, Cochrane, and Embase databases until December 2022. Two researchers independently screened the available studies. The Cochrane Risk of Bias tool was used to assess the risk of bias in the included studies. We used GRADEprofiler (version3.6) to analyze the evidence certainty. Primary outcomes such as liver fat content (LFC), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels, as well as secondary outcomes such as γ-glutamyltransferase (γGGT) and body weight, were evaluated. Then, each intervention was ranked by the surface under the cumulative ranking curve (SUCRA). As a supplement, we drew forest plots of subgroup using RevMan (version 5.4).

Results

Fourteen RCTs involving 1666 participants were included in the present study. The NMA results showed that exenatide (bid) was the best treatment for improving LFC compared with other agents, liraglutide, dulaglutide, semaglutide (qw) and placebo), and the SUCRA values were 66.8%. Among five interventions (except exenatide (bid) and semaglutide (qw)) evaluated for AST outcome, and six interventions (except exenatide (bid)) evaluated for ALT outcome, semaglutide (qd) was the most effective drug (SUCRA (AST) = 100%, SUCRA (ALT) = 95.6%). The result of LFC in daily group was MD = -3.66, 95% CI [-5.56, -1.76] and in weekly GLP-1RAs group, it was MD = -3.51, 95% CI [-4, -3.02]. As to AST and ALT, the results in daily group versus weekly group were AST: MD = -7.45, 95% CI [-14.57, -0.32] versus MD= -0.58, 95% CI [-3.18, 2.01] and ALT: MD = -11.12, 95% CI [-24.18, 1.95] versus MD = -5.62, 95% CI [-15.25, 4]. The quality of evidence was assessed as moderate or low.

Conclusion

The daily GLP-1RAs may be more effective in primary outcomes. And the daily semaglutide may be the most effective treatment for NAFLD and T2DM among the six interventions.

Genetic liability to gastro-esophageal reflux disease, obesity, and risk of idiopathic pulmonary fibrosis

BACKGROUND

Gastro-esophageal reflux disease (GORD) has been associated with a greater risk of idiopathic pulmonary fibrosis (IPF) in observational studies, but results are limited by confounding. We used multivariable Mendelian randomization to examine their causal relationship, adjusting for BMI.

METHODS

We selected genetic instruments for GORD from genome-wide association studies of 80,265 cases and 305,011 controls. Genetic association data for IPF were obtained from 2668 cases and 8591 controls, and BMI from 694,649 individuals. We used the inverse-variance weighted method and a series of sensitivity analyses including weak instrument robust methods.

RESULTS

Although genetic liability to GORD increased IPF risk (OR 1.58; 95% CI 1.10-2.25), this result was attenuated to include the null after adjusting for BMI (OR 1.14; 95% CI 0.85-1.52).

CONCLUSION

Intervention for GORD alone is unlikely to reduce the risk of IPF, whereas reducing obesity may be a better approach.

A comparative study in healthy and diabetic mice followed the exposure of polystyrene microplastics: Differential lipid metabolism and inflammation reaction

Human exposure to microplastics (MPs) continues to occur due to ingestion of contaminated food, water and air. Intake of MPs can pose potential health risks by interfering with the production and circulation of nutrients, leading to physiological stress (such as immune responses and metabolic abnormalities). Toxicity data of MPs based on healthy individuals may not be applicable to large populations of patients with chronic diseases represented by diabetes. Therefore, in this study, the response of diabetic mice was compared with that of healthy mice after exposure to polystyrene microplastics (PS-MPs), and interesting differences were observed. PS-MPs exposure significantly increased liver tissue damage, abnormal lipid metabolism, inflammatory effect, liver metabolic disorder and changes of intestinal microbial composition in diabetic mice. Moreover, PS-MPs overstated abnormal lipid metabolism in diabetic mice. The difference between the increased inflammation after exposure to PS-MPs in healthy and diabetic mice involves that the former is mainly modulated by gut microbes, while diabetic mice seem to be more susceptible to lipid metabolism disturbances. In addition, the size effect of MPs was also observed in diabetic mice. These results suggested that individuals with chronic diseases may be more sensitive to pollution due to altered homeostasis, and therefore disease status should be fully considered when assessing the health risk of pollutants.

Ablation of Tumor Necrosis Factor Alpha Receptor 1 Signaling Blunts Steatohepatitis in Peroxisome Proliferator Activated Receptor α-Deficient Mice

Tumor necrosis factor -alpha (TNFα) is strongly associated with fatty liver disease (i.e, hepatosteatosis). Cytokine production has been thought of as a consequence of hepatic lipid accumulation which becomes a critical factor in the development of chronic liver pathologies as well as insulin resistance. The purpose of this study was to test the hypothesis that TNFα directly regulates lipid metabolism in liver in the mutant peroxisome-proliferator activated receptor-alpha (PPARα^-/-) mouse model with robust hepatic lipid accumulation. At 10 weeks of age, TNFα and TNF receptor 1 expression are increased in livers of PPARα^-/- mice compared to wild type. PPARα^-/- mice were then crossed with mice lacking the receptor for TNFα receptor 1 (TNFR1^-/-). Wild type, PPARα^-/-, TNFR1^-/-, PPARα^-/- x TNFR1^-/- mice were housed on ad-libitum standard chow diet for up to 40 weeks. Increases in hepatic lipid and liver injury and metabolic disruption associated with PPARα ablation were largely blunted when PPARα^-/- mice were crossed with TNFR1^-/- mice. These data support the hypothesis that TNFR1 signaling is critical for accumulation of lipid in liver. Therapies that reduce pro-inflammatory responses, namely TNFα, could have important clinical implications to reduce hepatosteatosis and progression of severe liver disease.

Association of serum vitamin C with liver fibrosis in adults with nonalcoholic fatty liver disease

OBJECTIVE

This study aimed to investigate the association between serum vitamin C and liver fibrosis in patients with NAFLD in the US adults.

METHODS

We conducted a cross-sectional analysis of data from the 2017 to 2018 cycle of National Health and Nutrition Examination Survey (NHANES). Serum vitamin C and transient elastography (TE)-accessed liver stiffness was taken as independent and dependent variables, respectively. Liver steatosis and fibrosis were detected by controlling attenuation parameter (CAP) and TE. NAFLD was defined by a CAP score of ≥248 dB/m without any indication of other causes of chronic liver disease. The median liver stiffness of ≥8.2 kPa was used to identify significant fibrosis (≥F2) among NAFLD patients. We calculated the adjusted odds ratio (OR) and 95% confidential intervals (CIs) for associations with significant NAFLD fibrosis using multivariable logistic regression models.

RESULTS

Overall, 1926 individuals with NAFLD were included in the analysis and 267 subjects met the definition of significant fibrosis. Serum vitamin C was associated with lower odds of liver fibrosis in NAFLD after adjusting for potential confounders (OR = 0.60, 95% CI, 0.43-0.84), while in the subgroup analysis stratified by gender and body mass index (BMI), this association showed a difference after adjusting for confounders (males: OR = 0.43, 95% CI, 0.26-0.71; females: OR = 0.78, 95% CI, 0.49-1.24). There were no significant associations of serum vitamin C with liver fibrosis in NAFLD with underweight or normal (OR = 1.34, 95% CI, 0.19-9.34).

CONCLUSIONS

This cross-sectional study indicated an association of serum vitamin C with significant fibrosis in men and overweight or obese patients with NAFLD.

The Determinants of Liver Fibrosis in Patients with Nonalcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus

Liver fibrosis is a key pathophysiology process in chronic liver disease. It is still unclear whether the impact of liver fibrosis is not fully realized in type 2 diabetes mellitus (T2D) patients with nonalcoholic fatty liver disease (NAFLD), and the factors affecting nonalcoholic steatohepatitis (NASH) or liver stiffness also remain unclear. The aim of this study was to evaluate the determinants of liver fibrosis and in T2D patients with NAFLD. Liver fibrosis and steatosis were measured using transient elastography (FibroScan). Of 226 T2D patients with NAFLD, 50 with liver fibrosis had higher body mass index, serum uric acid, triglyceride and glycated hemoglobin levels and lower high density lipoprotein levels than 176 without liver fibrosis. Multivariate analysis revealed that aging, obesity, sulfonylurea usage and high levels of AST increased the risk of liver fibrosis in T2D patients with NAFLD. Our findings provide useful information to clinical physicians for earlier detection of liver fibrosis in T2D patients with NAFLD and to prevent liver fibrosis through controlling these risk factors.

The Impact of Insulin Resistance on Hepatic Fibrosis among United States Adults with Non-Alcoholic Fatty Liver Disease: NHANES 2017 to 2018

BACKGRUOUND

We aimed to investigate the association of hepatic steatosis with liver fibrosis and to assess the interactive effects of hepatic steatosis and insulin resistance on liver fibrosis in a nationally representative sample of United States adults.

METHODS

We conducted a cross-sectional analysis using data from National Health and Nutrition Examination Survey 2017 to 2018, which for the first time included transient elastography to assess liver stiffness and hepatic steatosis. We evaluated the association between hepatic steatosis (using controlled attenuation parameter [CAP]) and clinically significant liver fibrosis (defined as liver stiffness ≥7.5 kPa) using logistic regression with an interaction term for hepatic steatosis and insulin resistance (defined as homeostatic model assessment of insulin resistance ≥3.0).

RESULTS

Among adults undergoing transient elastography (n=2,023), 45.9% had moderate or greater hepatic steatosis and 11.3% had clinically significant liver fibrosis. After adjustment for demographic and metabolic factors, the odds of significant liver fibrosis increased as CAP score rose (odds ratio, 1.35 per standard deviation increment; 95% confidence interval, 1.11 to 1.64). We detected a significant interaction effect between CAP score and insulin resistance on the probability of significant liver fibrosis (P=0.016 for interaction). The probability of significant liver fibrosis increased in the presence of insulin resistance with increasing CAP score, while those without insulin resistance had low probability of significant liver fibrosis, even with high CAP scores.

CONCLUSION

Individuals with hepatic steatosis had higher odds of fibrosis when insulin resistance was present. Our findings emphasize the importance of the metabolic aspects of the disease on fibrosis risk and suggest a need to better identify patients with metabolic associated fatty liver disease.

The Regulation of Adipose Tissue Health by Estrogens

Obesity and its' associated metabolic diseases such as type 2 diabetes and cardiometabolic disorders are significant health problems confronting many countries. A major driver for developing obesity and metabolic dysfunction is the uncontrolled expansion of white adipose tissue (WAT). Specifically, the pathophysiological expansion of visceral WAT is often associated with metabolic dysfunction due to changes in adipokine secretion profiles, reduced vascularization, increased fibrosis, and enrichment of pro-inflammatory immune cells. A critical determinate of body fat distribution and WAT health is the sex steroid estrogen. The bioavailability of estrogen appears to favor metabolically healthy subcutaneous fat over visceral fat growth while protecting against changes in metabolic dysfunction. Our review will focus on the role of estrogen on body fat partitioning, WAT homeostasis, adipogenesis, adipocyte progenitor cell (APC) function, and thermogenesis to control WAT health and systemic metabolism.

Steatosis is involved in the progression of kidney disease in a high-fat-diet-induced non-alcoholic steatohepatitis mouse model

Chronic kidney disease (CKD) and non-alcoholic steatohepatitis (NASH) are major health issues associated with the metabolic syndrome. Although NASH is a known risk factor of CKD, the mechanisms linking these two diseases remain poorly understood. We aimed to investigate alterations in the kidney complicated with dyslipidemia in an established NASH mouse model. Male C57BL6/J mice were fed with control diet or high-fat diet (HFD), containing 40% fat, 22% fructose, and 2% cholesterol for 16 weeks. Metabolic characteristics, histological changes in the kidney, endoplasmic reticulum (ER) stress, apoptosis, and fibrosis were evaluated by histological analysis, immunoblotting, and quantitative reverse transcription-polymerase chain reaction. Levels of serum aspartate aminotransferase, alanine aminotransferase, alkali-phosphatase, total cholesterol, and urinary albumin were significantly higher in mice fed with HFD. Remarkable steatosis, glomerular hypertrophy, and interstitial fibrosis were also shown in in the kidney by leveraging HFD. Furthermore, HFD increased the mRNA expression levels of Casp3, Tgfb1, and Nfe2l2 and the protein level of BiP. We observed the early changes of CKD and speculate that the underlying mechanisms that link CKD and NASH are the induction of ER stress and apoptosis. Further, we observed the activation of Nfe2l2 in the steatosis-induced CKD mouse model. This NASH model holds implications in investigating the mechanisms linking dyslipidemia and CKD.

Liver Fibrosis in Asians With Metabolic Dysfunction-Associated Fatty Liver Disease

BACKGROUND & AIMS

This study aimed to evaluate risk factors associated with liver fibrosis in metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

A cross-sectional study of 967 Korean patients with MAFLD involved a cohort from a health screening program during the years 2015-2018. The patients were classified into 4 MAFLD subgroups: group 1 (overweight). group 2 (obese), group 3 (lean/normal weight with metabolic abnormalities), and group 4 (diabetes). Liver fibrosis was assessed based on liver stiffness measurement (LSM) value using 2-dimensional real-time magnetic resonance elastography. We investigated differences in liver fibrosis according to MAFLD subgroup classification and determined the risk factors for significant fibrosis.

RESULTS

The mean age was 50.8 years, and 869 (90%) patients were male. The mean value of LSM in magnetic resonance elastography was 2.48 ± 0.47 kPa. Significant fibrosis (LSM ≥2.97 kPa) was observed in 66 (6.8%) of 967 patients. The proportion of significant fibrosis in MAFLD group 1, group 2, group 3, and group 4 was 1.3%, 5.5%, 6.4%, and 18.9%, respectively (P < .001). Multivariable analysis indicated that the risk factors for significant fibrosis were serum ferritin ≥300 ng/mL (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.10-3.49; P = .023), Fibrosis-4 ≥1.3 (OR, 2.97; 95% CI, 1.68-5.24; P < .001), homeostatic model assessment of insulin resistance ≥2.0 (OR, 2.60; 95% CI, 1.25-5.43; P = .011), metabolic syndrome (OR, 2.53; 95% CI, 1.31-4.88; P = .006), and MAFLD group 4 (OR, 6.93; 95% CI, 1.96-24.51; P = .003). However, the etiology of liver disease was not statistically associated with liver fibrosis.

CONCLUSION

Liver fibrosis in patients with MAFLD varies according to subgroup classification based on diabetes, body mass index, and metabolic risk factors.

Prevalence of liver cirrhosis based on the metabolic health and weight criteria: Report from the Korea National Health and Nutrition Examination Survey (KNHANES) data analysis

BACKGROUND

Recent studies have proposed two distinctive types of obesity, metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUHO), based on various physiological factors. This study sought to explore the relationship between the metabolic obesity types and the incidence of liver cirrhosis (LC) in a large nationally-representative population.

METHODS

Data on 27,629 adults with MHO or MUHO, were analyzed from the Korea National Health and Nutrition Examination Survey (KNHANES) obtained from 2015 through 2019. Four categories of metabolic health and weight (MHW) were generated for analysis: (1) MHO, (2) MUHO, (3) Metabolically unhealthy normal weight (MUHNW), and (4) Metabolically healthy normal weight (MHNW). Statistical analyzes were performed with univariate and multivariate logistic regression.

RESULTS

The prevalence of LC did not show statistically significant differences among the MHW categories: 0.5% in MHO, 0.4% in MUHO, 0.2% in MHNW, and 0.3% in MUHNW. The unadjusted analysis showed a significant association between self-reported LC and MUHO, but this association was not evident in the adjusted analysis. In the adjusted analysis of the prevalence of laboratory LC, a significant association emerged in the MUHO group, followed in descending order of magnitude by the MHO and MUHNW groups. A favorable fasting blood glucose level was the only factor associated with increased prevalence of reported LC in MUHO.

CONCLUSIONS

The study demonstrated a difference in the prevalence of LC between MHO and MUHO. Our study concludes that the MHO phenotype is a transient status with regard to metabolic abnormalities, and caution is necessary when evaluating MHO.

The Mechanism of Lipopolysaccharide Escaping the Intestinal Barrier in Megalobrama amblycephala Fed a High-Fat Diet

With the popularity of western food characterized by excessive fat and sugars, obesity has currently been a public health issue. Low-grade chronic inflammation accompanied by obesity increases the risk of multiple epidemics such as diabetes, cancer and cardiovascular diseases. Here, we show that feeding Megalobrama amblycephala with a high-fat diet (HFD) drives obesity-related chronic inflammation and the penetration of lipopolysaccharide (LPS). Interference with antibiotics inhibits the produce of LPS and this alleviates the sustained release of pro-inflammatory factors induced by HFD. LPS penetration is attributed to weakened intestinal mucus barrier after high-fat exposure. Mechanically, the consumption of HFD inhibits the secretion of mucin 2 (MUC2) due to the induction of endoplasmic reticulum stress mediated by the inositol-requiring enzyme 1 (IRE1) /X box-binding protein 1 (XBP1) pathway in goblet cells. Furthermore, excessive lipid exacerbates the leakage of LPS across the intestinal epithelial cell barrier via the transcellular pathway. Mechanically, lipid increases the internalization of LPS in intestinal epithelial cells depending on the activation of fatty acid translocase (FAT/CD36). These results demonstrate that HFD causes the penetration of LPS due to the weakened intestinal mucosal barrier and the assistance of CD36.

Exploring the Mediating Effect of Physical Activities on Built Environment and Obesity for Elderly People: Evidence From Shanghai, China

There is still a scarcity of literature on the specific mechanisms of the linkage between the built environment and obesity. As a result, this study investigated whether and how physical activities mediate the associations between the objective built environment and the BMI of elderly people. To investigate the effect of the duration and intensity of physical activity on the effect of the built environment, the study made use of the bootstrap method. In general, we discovered that physical activity duration has a huge mediating effect on the elderly people in Shanghai, especially with respect to the density and accessibility of facilities (gyms, parks, fast-food restaurants) that can greatly stimulate physical activity in elderly people to reduce their BMI. There were both direct and indirect effects on their BMI, which means that the health benefits of green spaces for older people may be more complicated than first thought.

Keeping It Local in Metabolic Disease: Adipose Tissue Paracrine Signaling and Insulin Resistance

Alterations in adipose tissue composition and function are associated with obesity and contribute to the development of type 2 diabetes. While the significance of this relationship has been cemented, our understanding of the multifaceted role of adipose tissue in metabolic heath and disease continues to evolve and expand. Heterogenous populations of cells that make up adipose tissue throughout the body generate diverse secretomes containing a mosaic of bioactive compounds with vast structural and signaling capabilities. While there are many reports highlighting the important role of adipose tissue endocrine signaling in insulin resistance and type 2 diabetes, the direct, local, paracrine effect of adipose tissue has received less attention. Recent studies have begun to underscore the importance of considering anatomically discrete adipose depots for their specific impact on local microenvironments and metabolic function in neighboring tissues as well as regulation of whole-body physiology. This article highlights the important role of adipose tissue paracrine signaling on metabolic function and insulin sensitivity in nearby tissues and organs, specifically focusing on visceral, pancreatic, subcutaneous, intermuscular, and perivascular adipose tissue depots.

Non-alcoholic Fatty Liver Disease and Steatohepatitis: Risk Factors and Pathophysiology

Non-alcoholic fatty liver disease (NAFLD) and its progressive subtype non-alcoholic steatohepatitis (NASH) are the most prevalent liver diseases, often leading to hepatocellular carcinoma (HCC). This review aims to describe the present knowledge of the risk factors responsible for the development of NAFLD and NASH. I performed a literature review identifying studies focusing on the complex pathogenic pathway and risk factors of NAFLD and steatohepatitis. The relationship between NAFLD and metabolic syndrome is well established and widely recognized. Obesity, dyslipidemia, type 2 diabetes, hypertension, and insulin resistance are the most common risk factors associated with NAFLD. Among the components of metabolic syndrome, current evidence strongly suggests obesity and type 2 diabetes as risk factors of NASH and HCC. However, other elements, namely gender divergences, ethnicity, genetic factors, participation of innate immune system, oxidative stress, apoptotic pathways, and adipocytokines, take a leading role in the onset and promotion of NAFLD. Pathophysiological mechanisms that are responsible for NAFLD development and subsequent progression to NASH are insulin resistance and hyperinsulinemia, oxidative stress, hepatic stellate cell (HSC) activation, cytokine/adipokine signaling pathways, and genetic and environmental factors. Major pathophysiological findings of NAFLD are dysfunction of adipose tissue through the enhanced flow of free fatty acids (FFAs) and release of adipokines, and altered gut microbiome that generate proinflammatory signals and cause NASH progression. Understanding the pathophysiology and risk factors of NAFLD and NASH; this review could provide insight into the development of therapeutic strategies and useful diagnostic tools.

Leptin: an entry point for the treatment of peripheral tissue fibrosis and related diseases

Leptin is a small peptide mainly secreted by adipocyte, which acts on the central nervous system of the hypothalamus to regulate the body's energy balance by inhibiting food intake, it also can directly act on specific cells through leptin receptors (for example, ObRa, which exists in the blood-brain barrier or kidneys), thereby affect cell metabolism. Excessive deposition of extracellular matrix (ECM) causes damage to normal tissues or destruction of organ structure, which will eventually lead to tissue or organ fibrosis. The sustainable development of fibrosis can lead to structural damage and functional decline of organs, and even exhaustion, which seriously threatens human health and life. In recent years, studies have found that leptin directly alleviates the fibrosis process of various tissues and organs in mammals. Therefore, we speculate that leptin may become a significant treatment for fibrosis of various tissues and organs in the future. So, the main purpose of this review is to explore the specific mechanism of leptin in the process of fibrosis in multiple tissues and organs, and to provide a theoretical basis for the treatment of various tissues and organs fibrosis and related diseases caused by it, which is of great significance in the future.

MicroRNA-122-5p Inhibition Improves Inflammation and Oxidative Stress Damage in Dietary-Induced Non-alcoholic Fatty Liver Disease Through Targeting FOXO3

Misregulated microRNA network has been emerging as the main regulator in non-alcoholic fatty liver disease (NAFLD). The deregulation of miR-122-5p is associated with the liver disease. However, the specific role and molecular mechanism of miR-122-5p in NAFLD remain unclear. In this study, we have reported that the high-fat diet (HFD) or palmitic acid (PA) significantly upregulated the hepatic miR-122-5p expression in vivo and in vitro. Inhibition of miR-122-5p suppressed accumulation-induced inflammation of lipids and oxidative stress damage in PA-treated L02 cells and HFD-induced fatty liver. The effect of the miR-122-5p inhibitor on NAFLD did not depend on insulin resistance-mediated PI3K/AKT/mammalian target of rapamycin (mTOR) signaling pathway but rather on the upregulation of its downstream FOXO3. Subsequently, we validated that miR-122-5p directly binds to the predicted 3′-UTR of FOXO3 to inhibit its gene expression. Conversely, silencing FOXO3 abolished the hepatic benefits of miR-122-5p inhibition to obese mice by decreasing the activity of antioxidant enzymes of superoxide dismutase (SOD). This study provides a novel finding that FOXO3 was the target gene of miR-122-5p to attenuate inflammatory response and oxidative stress damage in dietary-induced NAFLD. Our study provided evidence to reveal the physiological role of miR-122-5p in dietary-induced NAFLD.

Cumulative Betel Quid Chewing and the Risk of Significant Liver Fibrosis in Subjects With and Without Metabolic Syndrome

Background

Betel quid chewing is associated with metabolic disorders, oral cancer, cardiovascular disease, and chronic liver diseases. Metabolic syndrome (MetS) is also a factor associated with liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). However, studies on the relationship between betel quid and liver fibrosis while also considering MetS are lacking. The aim of this study was thus to investigate the association of betel quid chewing and liver fibrosis with MetS.

Methods

A total of 9,221 subjects were enrolled after excluding subjects <18 years of age, with past history of chronic liver diseases, cancer, significant alcohol consumption, and incomplete data. Betel nut chewing habit was classified into three groups: none, former-chewing, and current-chewing, and cumulative exposure was calculated by multiplying the duration with the quantity. Liver fibrosis was evaluated based on the NAFLD fibrosis score (NFS), which is a composite score of age, hyperglycemia, BMI, platelet count, albumin, and the AST/ALT ratio. Significant liver fibrosis was defined as NFS ≥-1.455.

Results

After adjusting for other variables, MetS was positively associated with significant liver fibrosis. Subjects with both MetS and betel quid chewing had a higher associated risk of significant liver fibrosis than those with neither MetS nor betel quid chewing (adjusted OR: 3.03, 95% CI: 2.04–4.50, p < 0.001). Betel quid chewing was associated with significant liver fibrosis (adjusted OR: 2.00, 95% CI: 1.14–3.49, p = 0.015) in subjects with MetS, but not in subjects without.

Conclusion

Metabolic syndrome increased the associated risk of significant liver fibrosis. Cumulative betel quid exposure increased the associated risk of significant liver fibrosis in subjects with MetS, but not in subjects without.

Fibroblast Growth Factor 19 and Fibroblast Growth Factor 21 Regulation in Obese Diabetics, and Non-Alcoholic Fatty Liver Disease after Gastric Bypass

Background: Gastric bypass (GB) is an effective treatment for those who are morbidly obese with coexisting type 2 diabetes mellitus (T2DM) or non-alcoholic fatty liver disease (NAFLD). Fibroblast growth factors (FGFs) are involved in the regulation of energy metabolism. Methods: We investigated the roles of FGF 19, FGF 21, and total bile acid among those with morbidly obese and T2DM undergoing GB. A total of 35 patients were enrolled. Plasma FGF 19, FGF 21, and total bile acid levels were measured before surgery (M0), 3 months (M3), and 12 months (M12) after surgery, while the hepatic steatosis index (HSI) was calculated before and after surgery. Results: Obese patients with T2DM after GB presented with increased serum FGF 19 levels (p = 0.024) and decreased total bile acid (p = 0.01) and FGF 21 levels (p = 0.005). DM complete remitters had a higher FGF 19 level at M3 (p = 0.004) compared with DM non-complete remitters. Fatty liver improvers tended to have lower FGF 21 (p = 0.05) compared with non-improvers at M12. Conclusion: Changes in FGF 19 and FGF 21 play differential roles in DM remission and NAFLD improvement for patients after GB. Early increases in serum FGF 19 levels may predict complete remission of T2DM, while a decline in serum FGF 21 levels may reflect the improvement of NAFLD after GB.

Adipocyte-Specific Ablation of PU.1 Promotes Energy Expenditure and Ameliorates Metabolic Syndrome in Aging Mice

Objective: Although PU.1/Spi1 is known as a master regulator for macrophage development and function, we have reported previously that it is also expressed in adipocytes and is transcriptionally induced in obesity. Here, we investigated the role of adipocyte PU.1 in the development of the age-associated metabolic syndrome.

Methods: We generated mice with adipocyte-specific PU.1 knockout, assessed metabolic changes in young and older adult PU.1^fl/fl (control) and AdipoqCre PU.1^fl/fl (aPU.1KO) mice, including body weight, body composition, energy expenditure, and glucose homeostasis. We also performed transcriptional analyses using RNA-Sequencing of adipocytes from these mice.

Results: aPU.1KO mice have elevated energy expenditure at a young age and decreased adiposity and increased insulin sensitivity in later life. Corroborating these observations, transcriptional network analysis indicated the existence of validated, adipocyte PU.1-modulated regulatory hubs that direct inflammatory and thermogenic gene expression programs.

Conclusion: Our data provide evidence for a previously uncharacterized role of PU.1 in the development of age-associated obesity and insulin resistance.

Obesity and the Development of Lung Fibrosis

Obesity is an epidemic worldwide and the obese people suffer from a range of respiratory complications including fibrotic changes in the lung. The influence of obesity on the lung is multi-factorial, which is related to both mechanical injury and various inflammatory mediators produced by excessive adipose tissues, and infiltrated immune cells. Adiposity causes increased production of inflammatory mediators, for example, cytokines, chemokines, and adipokines, both locally and in the systemic circulation, thereby rendering susceptibility to respiratory diseases, and altered responses. Lung fibrosis is closely related to chronic inflammation in the lung. Current data suggest a link between lung fibrosis and diet-induced obesity, although the mechanism remains incomplete understood. This review summarizes findings on the association of lung fibrosis with obesity, highlights the role of several critical inflammatory mediators (e.g., TNF-α, TGF-β, and MCP-1) in obesity related lung fibrosis and the implication of obesity in the outcomes of idiopathic pulmonary fibrosis patients.

Chronic angiotensin receptor activation promotes hepatic triacylglycerol accumulation during an acute glucose challenge in obese-insulin-resistant OLETF rats

PURPOSE

Angiotensin receptor blockers (ARBs) can ameliorate metabolic syndrome (MetS)-associated dyslipidemia, hepatic steatosis, and glucose intolerance, suggesting that angiotensin receptor (AT1) over-activation contributes to impaired lipid and glucose metabolism, which is characteristic of MetS. The aim of this study was to evaluate changes in the lipid profile and proteins of fatty acid uptake, triacylglycerol (TAG) synthesis, and β-oxidation to better understand the links between AT1 overactivation and non-alcoholic fatty liver disease (NAFLD) during MetS.

METHODS

Four groups of 25-week-old-rats were used: (1) untreated LETO, (2) untreated OLETF, (3) OLETF + angiotensin receptor blocker (ARB; 10 mg olmesartan/kg/d × 8 weeks) and (4) OLETF ± ARB (MINUS; 10 mg olmesartan/kg/d × 4 weeks, then removed until dissection). To investigate the dynamic shifts in metabolism, animals were dissected after an oral glucose challenge (fasting, 3 and 6 h post-glucose).

RESULTS

Compared to OLETF, plasma total cholesterol and TAG remained unchanged in ARB. However, liver TAG was 55% lesser in ARB than OLETF, and remained lower throughout the challenge. Basal CD36 and ApoB were 28% and 29% lesser, respectively, in ARB than OLETF. PRDX6 abundance in ARB was 45% lesser than OLETF, and it negatively correlated with liver TAG in ARB.

CONCLUSIONS

Chronic blockade of AT1 protects the liver from TAG accumulation during glucose overload. This may be achieved by modulating NEFA uptake and increasing TAG export via ApoB. Our study highlights the contributions of AT1 signaling to impaired hepatic substrate metabolism and the detriments of a high-glucose load and its potential contribution to steatosis during MetS.

A meta-analysis of the effects of glucagon-like-peptide 1 receptor agonist (GLP1-RA) in nonalcoholic fatty liver disease (NAFLD) with type 2 diabetes (T2D)

Treatment options for nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D), two conditions which coexist, are limited though weight loss is an important strategy to improve outcomes in either disease. Glucagon-like peptide 1 receptor agonist (GLP1-RA) present a novel option to treat this dual disease by their salutary effects on glycaemic control and weight reduction. Eight randomized controlled trials on T2D and NAFLD from the Cochrane Library, Embase, and PubMed were included in this meta-analysis. The Comprehensive Meta-Analysis Software version 3 was used to calculate the effect size. In a pooled population of 615 patients-297 on GLP1-RA and 318 in the control arm, GLP1-RA produced a significant improvement in alanine aminotransferase [standardised mean difference (SDM), - 0.56, 95% CI - 0.88 to - 0.25, P < 0.01], aspartate aminotransferase (SDM, - 0.44, SE, 95% CI - 0.64 to - 0.24, P < 0.01), gamma glutaryl transaminase (SDM, - 0.60, 95% CI - 0.86 to - 0.34, P < 0.01) and reduction in liver fat content (LFC) (SDM, - 0.43, 95% CI - 0.74 to - 0.12, P < 0.01), as well as glycosylated haemoglobin (SDM, - 0.40, 95% CI, - 0.61 to - 0.19, P < 0.01) and weight (SDM, - 0.66, 95% CI, - 0.88 to - 0.44, P < 0.01), in comparison to standard of care or placebo. Significant improvement in biopsy resolution was also seen in the GLP1-RA arm (Rate Ratio, 6.60, 95% CI 2.67 to 16.29, P < 0.01). This is possibly the first meta-analysis conducted exclusively in patients with T2D and NAFLD which presents a strong signal that GLP1-RA, improve liver function and histology by improving glycaemia, reducing body weight and hepatic fat, which in turn reduces hepatic inflammation.Trial Registration: PROSPERO (ID: CRD42021228824).

The Obscure Effect of Tribulus terrestris Saponins Plus Inulin on Liver Morphology, Liver Fatty Acids, Plasma Glucose, and Lipid Profile in SD Rats with and without Induced Type 2 Diabetes Mellitus

Diabetes is a predictor of nonalcoholic fatty liver disease (NAFLD). There are data suggesting that Tribulus terrestris (TT) saponins act as antidiabetic agents and protect against NAFLD. The effect of saponins may be increased by fermentable fibers such as inulin. The aim of the present study was to investigate the influence of TT saponins and TT saponins plus inulin on the plasma lipid profile and liver fatty acids of rats with induced diabetes mellitus type 2 (T2DM). The study was performed on 36 male Sprague–Dawley rats divided into two main groups: control and diabetic. Animals of the diabetic (DM) group were fed a high-fat diet and injected with streptozotocin (low doses). Animals of the control group (nDM) were on a regular diet and were injected with buffer. After the injections, the animals were split into subgroups: three non-diabetic (nDM): (i) control (c-C); (ii) saponin-treated rats (C-Sap); (iii) rats treated with saponins + inulin (C-Sap + IN), and three diabetic subgroups (DM): (iv) control (c-DM); (v) saponin-treated rats (DM-Sap); (vi) rats treated with saponins + inulin (DM-Sap + IN). Liver fatty acids were extracted and analyzed by gas chromatography, and plasma glucose and lipids were measured. The study showed significant changes in liver morphology, liver fatty acids, plasma lipid profile, and plasma glucose. In summary, supplementation with TT saponins or saponins with inulin for one month decreased the level of steatosis in rats with induced type 2 diabetes. Moreover, there were favorable effects on the plasma lipid profile in the rats. However, additional supplementation with inulin had a negative effect on liver morphology (with a microvesicular type of steatosis) in the non-diabetes group. Moreover, supplementation with inulin had a negative effect on plasma glucose in both diabetic and non-diabetic rats. These data show that a diet enriched with fermentable fibers reveals different effects in different organisms, and not all sources and forms of fiber are beneficial to health.

Cellular protein markers, therapeutics, and drug delivery strategies in the treatment of diabetes-associated liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix due to chronic injuries, such as viral infection, alcohol abuse, high-fat diet, and toxins. Liver fibrosis is reversible before it progresses to cirrhosis and hepatocellular carcinoma. Type 2 diabetes significantly increases the risk of developing various complications including liver diseases. Abundant evidence suggests that type 2 diabetes and liver diseases are bidirectionally associated. Patients with type 2 diabetes experience more severe symptoms and accelerated progression of live diseases. Obesity and insulin resistance resulting from hyperlipidemia and hyperglycemia are regarded as the two major risk factors that link type 2 diabetes and liver fibrosis. This review summarizes possible mechanisms of the association between type 2 diabetes and liver fibrosis. The cellular protein markers that can be used for diagnosis and therapy of type 2 diabetes-associated liver fibrosis are discussed. We also highlight the potential therapeutic agents and their delivery systems that have been investigated for type 2 diabetes-associated liver fibrosis.

Outcomes of Idiopathic Pulmonary Fibrosis Improve with Obesity: A Rural Appalachian Experience

OBJECTIVES

Obesity can be an independent predictor of fibrosis in tissues, including the liver, heart, and skin. We evaluated a rural Appalachian cohort of idiopathic pulmonary fibrosis (IPF) for its relation to obesity.

METHODS

Using American Thoracic Society 2018 diagnostic guidelines, an IPF cohort was systematically identified at an Appalachian academic medical center (2015-2019). The cohort was categorized in subgroups of body mass index (BMI) <30 or BMI ≥30 kg/m². Demographics, clinical variables, and treatment details were collected retrospectively and evaluated for their associations with obesity.

RESULTS

In our IPF cohort (N = 138), a usual interstitial pneumonia pattern was less prevalent in the obese group (n = 49) relative to the nonobese group (69% vs 85%, respectively). The obese group was younger (mean age 73.27 ± 9.12 vs 77.97 ± 9.59 years) and had a higher prevalence of hypertension (90% vs 72%), hyperlipidemia (83% vs 68%), diabetes mellitus (47% vs 25%), sleep-disordered breathing (47% vs 25%), chronic pain disorders (28% vs 15%), and deep vein thrombosis (19% vs 7%). An increased proportion of obese-IPF patients was seen at a tertiary or an interstitial lung disease center, with more surgical lung biopsies performed and incident diagnosis (ie, within 6 months of presentation) assigned. Only a minority of patients underwent lung transplantation (3.6%), all of them from the obese-IPF subgroup. Approximately 30% of the total IPF cohort died, with a lower mortality observed in the obese group (35% vs 20%, P = 0.017). An increasing BMI predicted a better survival in the total IPF cohort (BMI 25-29.9, 20-24.9, and <20 had mortality rates of 20%, 47%, and 75%, respectively; P < 0.001).

CONCLUSIONS

Our study represents a first known effort to develop an IPF cohort in a rural Appalachian region. Although they shared an increased burden of comorbidities, the obese subgroup showed less advanced fibrosis with a lower mortality rate relative to nonobese subgroup, suggesting a potential "obesity paradox" in IPF. The study findings significantly advance our understanding of challenges posed by IPF in a rural population that also suffers from an alarming rate of obesity. We highlight the need for the multidisciplinary management of these patients and prospective studies to better define this complex relation.

Pathophysiology and Treatment Options for Hepatic Fibrosis: Can It Be Completely Cured?

Hepatic fibrosis is a dynamic process that occurs as a wound healing response against liver injury. During fibrosis, crosstalk between parenchymal and non-parenchymal cells, activation of different immune cells and signaling pathways, as well as a release of several inflammatory mediators take place, resulting in inflammation. Excessive inflammation drives hepatic stellate cell (HSC) activation, which then encounters various morphological and functional changes before transforming into proliferative and extracellular matrix (ECM)-producing myofibroblasts. Finally, enormous ECM accumulation interferes with hepatic function and leads to liver failure. To overcome this condition, several therapeutic approaches have been developed to inhibit inflammatory responses, HSC proliferation and activation. Preclinical studies also suggest several targets for the development of anti-fibrotic therapies; however, very few advanced to clinical trials. The pathophysiology of hepatic fibrosis is extremely complex and requires comprehensive understanding to identify effective therapeutic targets; therefore, in this review, we focus on the various cellular and molecular mechanisms associated with the pathophysiology of hepatic fibrosis and discuss potential strategies to control or reverse the fibrosis.

Early initiation of insulin attenuates histological and functional changes in the liver of streptozotocin-induced diabetic rats using 99mTc-sulfur colloid functional imaging

This study aimed to investigate the effect of insulin on the reticuloendothelial system (RES) in the liver and spleen in diabetic rats. Sprague Dawley rats were divided into control, diabetic rats (DM) and diabetic rats treated with insulin (IDM) for 2 weeks. Rats were imaged with technetium-99m-sulfur colloid (^99mTc-SC) tracer to determine regional distributions of the tracer for all groups by drawing regions of interest and then obtained the ratios as the cumulative counts of heart, liver, and spleen to the whole body (WB). Liver tissue from sacrificed rats from each group was examined by light and electron microscopy. ^99mTc-SC uptake ratios showed a lower liver to WB uptake ratio in the DM rats compared to both controls and IDM rats. Electron microscopy showed severe vacuolization of the hepatocytes of DM rats. The IDM rats show complete resolution of the vacuolization. The early administration of insulin for 2 weeks to diabetic rats could significantly resolve the phagocytic RES function and histological changes in the liver.

Ursolic Acid Lactone Obtained from Eucalyptus tereticornis Increases Glucose Uptake and Reduces Inflammatory Activity and Intracellular Neutral Fat: An In Vitro Study

Obesity has a strong relationship to insulin resistance and diabetes mellitus, a chronic metabolic disease that alters many physiological functions. Naturally derived drugs have aroused great interest in treating obesity, and triterpenoids are natural compounds with multiple biological activities and antidiabetic mechanisms. Here, we evaluated the bioactivity of ursolic acid lactone (UAL), a lesser-known triterpenoid, obtained from Eucalyptus tereticornis. We used different cell lines to show for the first time that this molecule exhibits anti-inflammatory properties in a macrophage model, increases glucose uptake in insulin-resistant muscle cells, and reduces triglyceride content in hepatocytes and adipocytes. In 3T3-L1 adipocytes, UAL inhibited the expression of genes involved in adipogenesis and lipogenesis, enhanced the expression of genes involved in fat oxidation, and increased AMP-activated protein kinase phosphorylation. The range of biological activities demonstrated in vitro indicates that UAL is a promising molecule for fighting diabetes.

Diet-Dependent Changes of the DNA Methylome Using a Göttingen Minipig Model for Obesity

Objective: Environmental factors can influence obesity by epigenetic mechanisms. The aim of this study was to investigate obesity-related epigenetic changes and the potential for reversal of these changes in the liver of Göttingen minipigs subjected to diet interventions. Methods: High-throughput liquid hybridization capture-based bisulfite sequencing (LHC-BS) was used to quantify the methylation status of gene promotor regions in liver tissue in three groups of male castrated Göttingen minipigs: a standard chow group (SD, N = 7); a group fed high fat/fructose/cholesterol diet (FFC, N = 10) and a group fed high fat/fructose/cholesterol diet during 7 months and reversed to standard diet for 6 months (FFC/SD, N = 12). Expression profiling by qPCR of selected metabolically relevant genes was performed in liver tissue from all pigs. Results: The pigs in the FFC diet group became morbidly obese. The FFC/SD diet did not result in a complete reversal of the body weight to the same weight as in the SD group, but it resulted in reversal of all lipid related metabolic parameters. Here we identified widespread differences in the patterning of cytosine methylation of promoters between the different feeding groups. By combining detection of differentially methylated genes with a rank-based hypergeometric overlap algorithm, we identified 160 genes showing differential methylation in corresponding promoter regions in the FFC diet group when comparing with both the SD and FFC/SD groups. As expected, this differential methylation under FFC diet intervention induced de-regulation of several metabolically-related genes involved in lipid/cholesterol metabolism, inflammatory response and fibrosis generation. Moreover, five genes, of which one is a fibrosis-related gene (MMP9), were still perturbed after diet reversion. Conclusion: Our findings highlight the potential of exploring diet-epigenome interactions for treatment of obesity.

Exposure to High-Fat Style Diet Induced Renal and Liver Structural Changes, Lipid Accumulation and Inflammation in Intact and Ovariectomized Female Rats

Purpose

We hypothesized that low estrogen levels aggravate obesity-related complications. Diet-induced obesity can cause distinct pathologies, including impaired glucose tolerance, inflammation, and organ injury that leads to fatty liver and chronic kidney diseases. To test this hypothesis, ovariectomized (OVX) rats were fed a high-fat style diet (HFSD), and we examined structural changes and inflammatory response in the kidney and liver.

Methods

Sprague-Dawley female rats were ovariectomized or sham-operated and divided into four groups: sham-operated rats fed a normal diet (ND); ovariectomized rats fed a normal diet (OVX-ND); sham-operated rats fed a HFSD; ovariectomized rats fed a high-fat style diet (OVX-HFSD). Mean blood pressure and fasting blood glucose were measured on weeks 0 and 10. The rats were sacrificed 10 weeks after initiation of ND or HFSD, the kidney and liver were harvested for histological, immunohistochemical and immunofluorescence studies.

Results

HFSD-fed rats presented a significantly greater adiposity index compared to their ND counterparts. Liver index, fasting blood glucose and mean blood pressure was increased in OVX-HFSD rats compared to HFSD rats at study terminal. Histological and morphometric studies showed focal interstitial mononuclear cell infiltration in the kidney of HFSD rats with mesangial expansion being greater in the OVX-HFSD rats. Both HFSD fed groups showed increased expressions of renal inflammatory markers, namely TNF-alpha, IL-6 and MCP-1, and infiltrating M1 macrophages with some influence of ovarian hormonal status. HFSD-feeding also caused hepatocellular steatosis which was aggravated in ovariectomized rats fed the same diet. Furthermore, hepatocellular ballooning was observed only in the OVX-HFSD rats. Similarly, HFSD-fed rats showed increased expressions of the inflammatory markers and M1 macrophage infiltration in the liver; however, only IL-6 expression was magnified in the OVX-HFSD.

Conclusion

Our data suggest that some of the structural changes and inflammatory response in the kidney and liver of rats fed a HFSD are exacerbated by ovariectomy.

The role of protein kinase D (PKD) in intracellular nutrient sensing and regulation of adaptive responses to the obese environment

Obesity is associated with ectopic accumulation of lipids, which is implicated in the development of insulin resistance, type 2 diabetes mellitus and cardiovascular disease. As the global prevalence of obesity continues to rise, it is becoming increasingly important to understand the underlying cellular mechanisms of this disease. Protein kinase D (PKD) is an intracellular signalling kinase with well characterized roles in intracellular vesicle transport and secretion, cancer cell proliferation and cardiac hypertrophy. However, emerging evidence also highlights PKD as a novel nutrient sensor. PKD activation is mediated by the accumulation of the lipid intermediate diacylglycerol, and PKD activity in the liver, heart and adipose tissue increases upon feeding. In obesity, PKD signalling is linked to reduced insulin signalling and dysfunction in adipose tissue, liver and heart, whilst in the pancreas, PKD is essential for the compensatory increase in glucose-stimulated insulin secretion from β-cells during obesity. Collectively, these studies reveal aspects of PKD signalling that are involved in the tissue-specific responses to obesity. This review summarizes the emerging evidence suggesting that PKD plays an important role in regulating the adaptive response to the obese environment.

Association between periodontitis and fibrotic progression of non-alcoholic fatty liver among Japanese adults

AIM

Non-alcoholic fatty liver (NAFL) is known to develop into liver fibrosis, which increases the risk of liver cirrhosis and liver cancer. The association between periodontal condition and fibrotic progression of NAFL is unclear. This study aimed to clarify this longitudinal association.

MATERIALS AND METHODS

Among 4812 participants aged 35-64 years undergoing annual health check-ups between 2003 and 2004, and follow-up 5 years later, 392 participants were diagnosed with NAFL. After excluding participants with liver fibrosis at baseline, 341 participants were followed up for 5 years. NAFL disease fibrosis score of ≥-1.455 was used to evaluate the probability of the presence of liver fibrosis.

RESULTS

During the follow-up period, 10.6% of participants progressed to liver fibrosis. A higher clinical attachment level (CAL) tended to be associated with the incidence of liver fibrosis in the logistic regression analysis (odds ratio [OR] 1.82, 95% confidence interval [CI], 0.94-3.49, p = .074). The stratified analysis by obesity revealed a significant association with higher CAL in obese participants (OR 2.87, 95% CI, 1.23-6.69, p = .015), but not in non-obese participants.

CONCLUSION

Higher CAL was associated with an increased probability of liver fibrosis in obese adults with NAFL.

Epidemiology of non-alcoholic fatty liver disease and risk of hepatocellular carcinoma progression

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. Its incidence has grown alongside the increasing global prevalence of type 2 diabetes, obesity, and metabolic syndrome. The risk of progression to hepatocellular carcinoma for nonalcoholic steatohepatitis patients over 5 years is 8%, and despite targeted and immunotherapy treatment advances, HCC maintains a bleak 5-year survival of 19%. NAFLD’s primary risk factors are components of metabolic syndrome as well as possible sleep disturbances. NAFLD is most common among men 50-60 years of age, though incidence in women catches up after menopause. In the US, Hispanics are most likely to develop NAFLD and African Americans least likely, in part due to the prevalence of the PNPLA3 gene variant. With NAFLD risk factors especially prevalent in underserved populations and developing nations, public health interventions, earlier diagnosis, and novel treatments could curb the growing disease burden.

The Use of Two-Dimensional Shear Wave Elastography in People with Obesity for the Assessment of Liver Fibrosis in Non-Alcoholic Fatty Liver Disease

Obesity is associated with significant comorbidities, including non-alcoholic fatty liver disease (NAFLD). Given its potential to progress to advanced liver disease, monitoring the extent and progress of liver fibrosis and assessing its fibrosis stage are essential. Although liver biopsy is considered to be the gold standard for liver fibrosis staging, it is an invasive procedure with risk of complications. Considering the rising prevalence of obesity and NAFLD globally, developing non-invasive diagnostic methods is a priority. Transient elastography (TE) is increasingly being used to assess the severity of liver disease. However, in the presence of severe obesity, the increased thickness of subcutaneous adipose tissue and changes in anatomy may affect its diagnostic accuracy. Two-dimensional shear wave elastography (2D-SWE) assesses the liver stiffness in real time along with simultaneous anatomic B-mode ultrasound imaging and allows selection of the region of interest. This would suggest that 2D-SWE has several advantages over TE in patients with severe obesity. The purpose of this review is to examine the current literature addressing the use of 2D-SWE in the assessment of liver fibrosis in patients with NAFLD. This review also examines the evidence on the use of 2D-SWE in patients with obesity and NAFLD and compares it to TE as a novel and non-invasive method of assessing liver fibrosis.

A model integrating donor gene polymorphisms predicts fibrosis after liver transplantation

Post-transplant liver fibrosis (PTLF) is a common and severe complication in liver recipients. In this study, we assessed the impact of donor liver genetics on the development of PTLF. A total of 232 patients undergoing liver transplantation were included. Twenty-two single nucleotide polymorphisms (SNPs) associated with liver fibrosis were analyzed. Univariate analysis revealed seven donor SNPs to be associated with PTLF. In a multivariate analysis, independent risk factors of PTLF were genetic variation of donor GRP78 rs430397 (OR = 8.99, p = 0.003), GSTP1 rs1695 (OR = 0.13, p = 0.021), miRNA-196a rs12304647 (OR = 16.01, p =0.001), and TNF-α rs1800630 (OR = 79.78, p = 0.001); blood tacrolimus levels at maintenance > 7 ng/ml (OR =7.48, p <0.001); and post-transplant diabetes mellitus (OR = 7.50, p = 0.001). A predictive model that included donor SNPs showed better prognostic ability for PTLF than a model with only clinical parameters (AUROC: 0.863 vs 0.707, P < 0.001). Given that donor gene SNPs are associated with an increased risk of PTLF, this model integrated with donor gene polymorphisms may help clinicians predict PTLF.

The mother relationship between insulin resistance and non-alcoholic steatohepatitis: Glucosinolates hydrolysis products as a promising insulin resistance-modulator and fatty liver-preventer

Non-alcoholic fatty liver disease (NFLD) is one of the present public health problems which have no specific and effective treatment. The speed of the disease progression depends on the patient's lifestyle. Due to life stresses and lack of time, a high number of people depend on fast food containing a high amount of fats which one of the main causes of insulin resistance (IR). IR is one of the metabolic disorders which strongly intersected with molecular NAFLD and leading to its progression into non-alcoholic steatohepatitis (NASH). In this review, we introduced the updated statistics of NAFLD and NASH progression all over the world shows its importance, etiologies, and pathogenesis. Also, IR and its role in NASH initiation and progression explored, and current treatments with its limitations have been explained. Glucosinolates (GLS) is a group of phytochemicals which known by its potent hydrolysis products with promising anti-cancer effect. In this review, we have collected the recent experimental studies of different GLS hydrolysis products against IR and chronic liver diseases supported by our lab finding. Finally, we recommend this group of phytochemicals as promising molecules to be studied experimentally and clinically against a wide range of chronic liver diseases with an acceptable safety margin.

Differential long noncoding RNA profiling of BMI in twins

Aim: Many efforts have been deployed to identify genetic variants associated with BMI. Alternatively, we explore epigenetic contribution to BMI variation by focusing on long noncoding RNAs (lncRNAs) which represents a key layer of epigenetic control. Materials & methods: We analyzed lncRNA expression in whole blood of 229 monozygotic twin pairs in association with BMI using generalized estimating equations. Results & conclusion: Six lncRNA probes were identified as significant (false discovery rate <0.05), with BMI showing causal effects on the expression of the significant lncRNAs. Functional annotation of differential profiles identified Gene ontology biological processes including kidney development, regulations of lipid biosynthetic process, circadian rhythm, notch signaling, etc. Whole blood lncRNAs are significantly expressed in response to BMI variation.

Predicting microRNA-disease associations from lncRNA-microRNA interactions via Multiview Multitask Learning

MOTIVATION

Identifying microRNAs that are associated with different diseases as biomarkers is a problem of great medical significance. Existing computational methods for uncovering such microRNA-diseases associations (MDAs) are mostly developed under the assumption that similar microRNAs tend to associate with similar diseases. Since such an assumption is not always valid, these methods may not always be applicable to all kinds of MDAs. Considering that the relationship between long noncoding RNA (lncRNA) and different diseases and the co-regulation relationships between the biological functions of lncRNA and microRNA have been established, we propose here a multiview multitask method to make use of the known lncRNA-microRNA interaction to predict MDAs on a large scale. The investigation is performed in the absence of complete information of microRNAs and any similarity measurement for it and to the best knowledge, the work represents the first ever attempt to discover MDAs based on lncRNA-microRNA interactions.

RESULTS

In this paper, we propose to develop a deep learning model called MVMTMDA that can create a multiview representation of microRNAs. The model is trained based on an end-to-end multitasking approach to machine learning so that, based on it, missing data in the side information can be determined automatically. Experimental results show that the proposed model yields an average area under ROC curve of 0.8410+/-0.018, 0.8512+/-0.012 and 0.8521+/-0.008 when k is set to 2, 5 and 10, respectively. In addition, we also propose here a statistical approach to predicting lncRNA-disease associations based on these associations and the MDA discovered using MVMTMDA.

AVAILABILITY

Python code and the datasets used in our studies are made available at https://github.com/yahuang1991polyu/MVMTMDA/.