Fat Accumulation In Hepatocytes Research Articles

Exosomes regulate SIRT3-related autophagy by delivering miR-421 to regulate macrophage polarization and participate in OSA-related NAFLD

PurposeTo analyze the role of and mechanism underlying obstructive sleep apnea (OSA)-derived exosomes in inducing non-alcoholic fatty liver (NAFLD).MethodsThe role of OSA-derived exosomes was analyzed in inducing hepatocyte fat accumulation in mice models both in vivo and in vitro.ResultsOSA-derived exosomes caused fat accumulation and macrophage activation in the liver tissue. These exosomes promoted fat accumulation; steatosis was more noticeable in the presence of macrophages. Macrophages could internalize OSA-derived exosomes, which promoted macrophage polarization to the M1 type. Moreover, it inhibited sirtuin-3 (SIRT3)/AMP-activated protein kinase (AMPK) and autophagy and promoted the activation of nucleotide-binding domain, leucine-rich–containing family, pyrin domain–containing-3 (NLRP3) inflammasomes. The use of 3-methyladenine (3-MA) to inhibit autophagy blocked NLRP3 inflammasome activation and inhibited the M1 polarization of macrophages. miR-421 targeting inhibited SIRT3 protein expression in the macrophages. miR-421 was significantly increased in OSA-derived exosomes. Additionally, miR-421 levels were increased in OSA + NAFLD mice- and patient-derived exosomes. In the liver tissues of OSA and OSA + NAFLD mice, miR-421 displayed similar co-localization with the macrophages. Intermittent hypoxia-induced hepatocytes deliver miR-421 to the macrophages via exosomes to inhibit SIRT3, thereby participating in macrophage M1 polarization. After OSA and NAFLD modeling in miR-421−/− mice, liver steatosis and M1 polarization were significantly reduced. Additionally, in the case of miR-421 knockout, the inhibitory effects of OSA-derived exosomes on SIRT3 and autophagy were significantly alleviated. Furthermore, their effects on liver steatosis and macrophage M1 polarization were significantly reduced.ConclusionsOSA promotes the delivery of miR-421 from the hepatocytes to macrophages. Additionally, it promotes M1 polarization by regulating the SIRT3/AMPK-autophagy pathway, thereby causing NAFLD.

Low Hepatic Cardiolipin Levels Promote Increased Mitochondrial Electron Leak and Metabolic Dysfunction-associated Steatohepatitis

Mitochondria adapt to changing energetic demands of the cell. We recently reported that mitochondrial membrane lipid composition represents a regulatory mechanism by which effciency of oxidative phosphorylation becomes altered. Metabolic-associated fatty liver disease (MAFLD) is a progressive disorder characterized by oxidative stress and accumulation of fat in hepatocytes that can lead to metabolic dysfunction-associated steatohepatitis (MASH). We hypothesized that MAFLD alters mitochondrial membrane lipids to induce mitochondrial electron transfer ineffciency and promotes oxidative stress. Lipid mass spectrometric analyses in four models of MAFLD (high-fat diet, ob/ob, carbon tetrachloride administration (CCI4), and Gubra-Amylin-NASH® diet), revealed that low mitochondrial cardiolipin (CL) is a common signature associated with all MAFLD models. In hepa1-6 cells, lentivirus-mediated knockdown of cardiolipin synthase (CLS, generates CL in mitochondria) was suffcient to reduce respiration and increase electron leak. Liver mitochondria from mice with a hepatocyte-specific knockout of CLS exhibited defects in mitochondrial bioenergetics including increased electron leak, concomitant to pathogenesis of MASH. Together, these findings provide evidence that a reduction in hepatic cardiolipin may drive the progression of MAFLD to induce MASH pathology. R01GM144613-03R01AG074535-02S2R01DK107397 07. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Role of ghrelin hormone in the development of alcohol-associated liver disease

Fatty liver is the earliest response of the liver to excessive alcohol consumption. Previously we identified that chronic alcohol administration increases levels of stomach-derived hormone, ghrelin, which by reducing circulating insulin levels, ultimately contributes to the development of alcohol-associated liver disease (ALD). In addition, ghrelin directly promotes fat accumulation in hepatocytes by enhancing de novo lipogenesis. Other than promoting ALD, ghrelin is known to increase alcohol craving and intake. In this study, we used a ghrelin receptor (GHSR) knockout (KO) rat model to characterize the specific contribution of ghrelin in the development of ALD with emphasis on energy homeostasis. Male Wistar wild type (WT) and GHSR-KO rats were pair-fed the Lieber-DeCarli control or ethanol diet for 6 weeks. At the end of the feeding period, glucose tolerance test was conducted, and tissue samples were collected. We observed reduced alcohol intake by GHSR-KOs compared to a previous study where WT rats were fed ethanol diet ad libitum. Further, when the WTs were pair-fed to GHSR-KOs, the KO rats exhibited resistance to develop ALD through improving insulin secretion/sensitivity to reduce adipose lipolysis and hepatic fatty acid uptake/synthesis and increase fatty acid oxidation. Furthermore, proteomic data revealed that ethanol-fed KO exhibit less alcohol-induced mitochondrial dysfunction and oxidative stress than WT rats. Proteomic data also confirmed that the ethanol-fed KOs are insulin sensitive and are resistant to hepatic steatosis development compared to WT rats. Together, these data confirm that inhibiting ghrelin action prevent alcohol-induced liver and adipose dysfunction independent of reducing alcohol intake.

Ultrasonic evaluation MAFLD in screening severety matabolic disorders

Metabolic dysfunction associated fatty liver disease (MAFLD) is a new proposed term for non-alcoholic fatty liver disease (NAFLD). a liver steatosis associated with Type 2 diabetes mellitus or increased physical weight/thickness, or with two or more metabolic disorders. This indicates metabolic abnormalities that result in fat accumulation in hepatocytes without the presence of alcoholic liver disease or other causes that would lead to hepatocyte abnormalities. Our goal was determine the correlation between certain stages of fatty liver disease determined by ultrasonography with increased body weight/obesity, diabetes mellitus and other metabolic disorders and with the values of biochemical parameters of liver enzymes. A prospective study was conducted at the public health institution Zivinice Health Center from August 2022 until January 2024 on a random sample of 101 patients. Observing the entire examined group, a difference in the gender distribution of hepatic steatosis is noticed, and graphically it is shown that men have hepatic steatosis more often than women. In fatty liver disease (MAFLD), stage G2 was most prevalent in 32% of patients. Ultrasonography, along with clinical and biochemical indicators, should be an integral part of screening and monitoring of metabolic disorders as it is a non-invasive and easily accessible imaging method and allows timely therapeutic action and prevention of hepatic and extrahepatic complications.

Gene Silencing of Angiopoietin-like 3 (ANGPTL3) Induced De Novo Lipogenesis and Lipid Accumulation in Huh7 Cell Line.

Angiopoietin-like 3 (ANGPTL3) is a hepatokine acting as a negative regulator of lipoprotein lipase (LPL). Vupanorsen, an ANGPTL3 directed antisense oligonucleotide, showed an unexpected increase in liver fat content in humans. Here, we investigated the molecular mechanism linking ANGPTL3 silencing to hepatocyte fat accumulation. Human hepatocarcinoma Huh7 cells were treated with small interfering RNA (siRNA) directed to ANGPTL3, human recombinant ANGPTL3 (recANGPTL3), or their combination. Using Western blot, Oil Red-O, biochemical assays, and ELISA, we analyzed the expression of genes and proteins involved in lipid metabolism. Oil Red-O staining demonstrated that lipid content increased after 48 h of ANGPTL3 silencing (5.89 ± 0.33 fold), incubation with recANGPTL3 (4.08 ± 0.35 fold), or their combination (8.56 ± 0.18 fold), compared to untreated cells. This effect was also confirmed in Huh7-LX2 spheroids. A total of 48 h of ANGPTL3 silencing induced the expression of genes involved in the de novo lipogenesis, such as fatty acid synthase, stearoyl-CoA desaturase, ATP citrate lyase, and Acetyl-Coenzyme A Carboxylase 1 together with the proprotein convertase subtilisin/kexin 9 (PCSK9). Time-course experiments revealed that 6 h post transfection with ANGPTL3-siRNA, the cholesterol esterification by Acyl-coenzyme A cholesterol acyltransferase (ACAT) was reduced, as well as total cholesterol content, while an opposite effect was observed at 48 h. Under the same experimental conditions, no differences in secreted apoB and PCSK9 were observed. Since PCSK9 was altered by the treatment, we tested a possible co-regulation between the two genes. The effect of ANGPTL3-siRNA on the expression of genes involved in the de novo lipogenesis was not counteracted by gene silencing of PCSK9. In conclusion, our in vitro study suggests that ANGPTL3 silencing determines lipid accumulation in Huh7 cells by inducing the de novo lipogenesis independently from PCSK9.

Mechanisms of ferroptosis in nonalcoholic fatty liver disease and therapeutic effects of traditional Chinese medicine: a review.

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of fat in hepatocytes (nonalcoholic fatty liver (NAFL)), and lobular inflammation and hepatocyte damage (which characterize nonalcoholic steatohepatitis (NASH) are found in most patients). A subset of patients will gradually develop liver fibrosis, cirrhosis, and eventually hepatocellular carcinoma, which is a deadly disease that threatens human life worldwide. Ferroptosis, a novel nonapoptotic form of programmed cell death (PCD) characterized by iron-dependent accumulation of reactive oxygen radicals and lipid peroxides, is closely related to NAFLD. Traditional Chinese medicine (TCM) has unique advantages in the prevention and treatment of NAFLD due to its multicomponent, multipathway and multitarget characteristics. In this review, we discuss the effect of TCM on NAFLD by regulating ferroptosis, in order to provide reference for the further development and application of therapeutic drugs to treat NAFLD.

El estrés psicosocial en la esteatosis hepática asociada a disfunción metabólica (MASLD): sobreposición desfavorable

The metabolic dysfunction-associated steatotic liver disease (MASLD)(1) is considered the leading cause of liver disease worldwide. It is a complex pathology, which includes a spectrum of diseases ranging from steatosis to advanced forms of liver damage, such as cirrhosis. Its prevalence has increased in recent years, becoming a relevant public health problem. It is characterized by fat accumulation in hepatocytes, which induces lipotoxicity, oxidative stress, inflammation, and consequently, liver damage. The mechanisms involved in MASLD progression are not fully understood. Also, the factors that determine the heterogeneous susceptibility towards liver fibrosis among patients, remain unresolved. In recent years, chronic stress has been described as a relevant risk factor in the progression of MASLD. The presence of stress is associated with alterations in the gut-liver-brain axis, which promotes systemic low-grade inflammation that reinforces the liver damage progression. This review aims to discuss the evidence about the role of psychosocial stress in MASLD and its association with the pathogenic mechanisms involved in liver damage.

Effects of plant natural products on metabolic-associated fatty liver disease and the underlying mechanisms: a narrative review with a focus on the modulation of the gut microbiota.

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease characterized by the excessive accumulation of fat in hepatocytes. However, due to the complex pathogenesis of MAFLD, there are no officially approved drugs for treatment. Therefore, there is an urgent need to find safe and effective anti-MAFLD drugs. Recently, the relationship between the gut microbiota and MAFLD has been widely recognized, and treating MAFLD by regulating the gut microbiota may be a new therapeutic strategy. Natural products, especially plant natural products, have attracted much attention in the treatment of MAFLD due to their multiple targets and pathways and few side effects. Moreover, the structure and function of the gut microbiota can be influenced by exposure to plant natural products. However, the effects of plant natural products on MAFLD through targeting of the gut microbiota and the underlying mechanisms are poorly understood. Based on the above information and to address the potential therapeutic role of plant natural products in MAFLD, we systematically summarize the effects and mechanisms of action of plant natural products in the prevention and treatment of MAFLD through targeting of the gut microbiota. This narrative review provides feasible ideas for further exploration of safer and more effective natural drugs for the prevention and treatment of MAFLD.

(+)-Lipoic acid reduces mitochondrial unfolded protein response and attenuates oxidative stress and aging in an in vitro model of non-alcoholic fatty liver disease

BackgroundNon-alcoholic fatty liver disease (NAFLD) is a liver disorder characterized by the ac-cumulation of fat in hepatocytes without alcohol consumption. Mitochondrial dysfunction and endoplasmic reticulum (ER) stress play significant roles in NAFLD pathogenesis. The unfolded protein response in mitochondria (UPRmt) is an adaptive mechanism that aims to restore mitochondrial protein homeostasis and mitigate cellular stress. This study aimed to investigate the effects of ( +)-Lipoic acid (ALA) on UPRmt, inflammation, and oxidative stress in an in vitro model of NAFLD using HepG2 cells treated with palmitic acid and oleic acid to induce steatosis.ResultsTreatment with palmitic and oleic acids increased UPRmt-related proteins HSP90 and HSP60 (heat shock protein), and decreased CLPP (caseinolytic protease P), indicating ER stress activation. ALA treatment at 1 μM and 5 μM restored UPRmt-related protein levels. PA:OA (palmitic acid:oleic acid)-induced ER stress markers IRE1α (Inositol requiring enzyme-1), CHOP (C/EBP Homologous Protein), BIP (Binding Immunoglobulin Protein), and BAX (Bcl-2-associated X protein) were significantly reduced by ALA treatment. ALA also enhanced ER-mediated protein glycosylation and reduced oxidative stress, as evidenced by decreased GPX1 (Glutathione peroxidase 1), GSTP1 (glutathione S-transferase pi 1), and GSR (glutathione-disulfide reductase) expression and increased GSH (Glutathione) levels, and improved cellular senescence as shown by the markers β-galactosidase, γH2Ax and Klotho-beta.ConclusionsIn conclusion, ALA ameliorated ER stress, oxidative stress, and inflammation in HepG2 cells treated with palmitic and oleic acids, potentially offering therapeutic benefits for NAFLD providing a possible biochemical mechanism underlying ALA beneficial effects.Graphical

Liver damage of autopsied patients with acquired immunodeficiency syndrome and antirretroviral therapy effect

Aim: To evaluate steatosis percentage and hepatic interstitial fibers of autopsied patients with Acquired Immunodeficiency Syndrome (AIDS), relating to the use of antiretroviral therapy (ART). Methods: 62 liver fragments from patients with and without AIDS autopsied from 1996 to 2017, matched by age (18-49), gender and race. These patients were divided in two groups: patients with AIDS (n=31) and patients without AIDS (n=31). Patients with AIDS were analyzed according to treatment on ART (n=15) or non-ART (n=16). In the histomorphometric analysis sections were made and stained with hematoxylin-eosin, picrosirius and reticulin for steatosis, type I and type III collagen analysis, respectively. Results: Patients with AIDS showed significantly larger steatosis percentage (26.05 vs 21.95%, p<0.001), type I collagen (1.63 vs 1.01%, p<0.001) and type III collagen (8.68 vs 7.83%, p<0.001). Patients with AIDS on ART showed significantly lower steatosis percentage (25.45 vs 26.36%, p<0.001) and type I collagen (1.52 vs 1.75%, p<0.001). Patients with AIDS on ART showed lower percentage of type III collagen (8.52 vs 8.77%, p<0.96), however it was not statistically significant. Conclusion: AIDS increases in hepatocyte fat accumulation and steatosis and liver fibrosis. However, ART has a decreased beneficial role in hepatocyte fat accumulation and fibrosis development since the medication detains both processes.

Lipid Peroxidation in Ferroptosis and Association with Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) constitutes a commonly diagnosed liver pathology with perturbed lipid metabolism, which is mainly caused by excessive accumulation of fat in hepatocytes by various pathogenic factors. Currently, there are no effective drug treatments for NAFLD. Ferroptosis represents a novel form of programmed cell death depending on iron, which is driven by large cellular amounts of reactive oxygen species (ROS) and lipid peroxides. Ferroptosis plays critical regulatory roles in the pathogenesis of NAFLD, and overaccumulation of Fe2+ contributes to lipid peroxidation, which subsequently aggravates NAFLD. Therefore, ferroptosis suppression might constitute an important target for NAFLD treatment. This article reviews the discovery, production pathways, and defense mechanisms of ferroptosis, and explores its association with NAFLD. This may provide new reference targets and strategies for the development of NAFLD drugs from the perspective of ferroptosis.

Gut-derived ammonia contributes to alcohol-related fatty liver development via facilitating ethanol metabolism and provoking ATF4-dependent de novo lipogenesis activation

Background & aimsDysbiosis contributes to alcohol-associated liver disease (ALD); however, the precise mechanisms remain elusive. Given the critical role of the gut microbiota in ammonia production, we herein aim to investigate whether and how gut-derived ammonia contributes to ALD. MethodsBlood samples were collected from human subjects with/without alcohol drinking. Mice were exposed to the Lieber-DeCarli isocaloric control or ethanol-containing diets with and without rifaximin (a nonabsorbable antibiotic clinically used for lowering gut ammonia production) supplementation for five weeks. Both in vitro (NH4Cl exposure of AML12 hepatocytes) and in vivo (urease administration for 5 days in mice) hyperammonemia models were employed. RNA sequencing and fecal amplicon sequencing were performed. Ammonia and triglyceride concentrations were measured. The gene and protein expression of enzymes involved in multiple pathways were measured. ResultsChronic alcohol consumption causes hyperammonemia in both mice and human subjects. In healthy livers and hepatocytes, ammonia exposure upregulates the expression of urea cycle genes, elevates hepatic de novo lipogenesis (DNL), and increases fat accumulation. Intriguingly, ammonia promotes ethanol catabolism and acetyl-CoA formation, which, together with ammonia, synergistically facilitates intracellular fat accumulation in hepatocytes. Mechanistic investigations uncovered that ATF4 activation, as a result of ER stress induction and general control nonderepressible 2 activation, plays a central role in ammonia-provoked DNL elevation. Rifaximin ameliorates ALD pathologies in mice, concomitant with blunted hepatic ER stress induction, ATF4 activation, and DNL activation. ConclusionsAn overproduction of ammonia by gut microbiota, synergistically interacting with ethanol, is a significant contributor to ALD pathologies.

Female and male obese Zucker rats display differential inflammatory mediator and long non-coding RNA profiles

AimsThe goal of this study was to identify mediators in peri-lymphatic adipose tissue (PLAT) that are altered in obese versus lean Zucker rats, with focus on potential sex differences Main methodsMesenteric PLAT was analyzed with protein and lncRNA arrays. Additional RT-PCR confirmation was performed with epididymal/ovarian fat. Key findingsMCP-1, TCK-1, Galectin-1, Galectin-3, and neuropilin-1 were elevated in PLAT from obese rats of both sexes. However, 11 additional proteins were elevated only in obese males while 24 different proteins were elevated in obese females. Profiling of lncRNAs revealed lean males have elevated levels of NEAT1, MALAT1 and GAS5 compared to lean females. NEAT1, MALAT1, and GAS5 were significantly reduced with obesity in males but not in females. Another lncRNA, HOTAIR, was higher in lean females compared to males, and its levels in females were reduced with obesity. Obese rats of both sexes had similar histologic findings of mesenteric macrophage crown-like structures and hepatocyte fat accumulation. SignificanceWhile obese male and female Zucker rats both have increased inflammation, they have distinct signals. Future studies of the proteome and lncRNA landscape of obese males vs. females in various animal models and in human subjects are warranted to better guide development of therapeutics for obesity-induced inflammation.

Chronic toxicity assessment of nano-formulated Bischofia javanica leaves: Implications for pharmacological use

This study explores the chronic toxicity of nano-formulated Bischofia javanica leaves, a plant with pharmacological significance in Indonesia, following OECD guidelines 452. Graded doses (2, 4, 6, and 8 g/kg BW) of nano-formulated Bischofia javanica were administered to the treatment groups for 60 days, while the control group (K-) received only water. On the 61st day, the mice were euthanized, and samples for biochemical, hematological, and histopathological analysis were collected. Statistical analysis involved one-way ANOVA and Tukey’s post hoc tests. Graded doses of nano-formulated Bischofia javanica leaves caused significant alterations in liver function. Doses between 2 and 4 g/kg BW improved liver histology and physiological markers. Higher doses (6 to 8 g/kg BW) led to liver dysfunction and histological degeneration, characterized by substantial fatty alterations, intracellular fat accumulation in hepatocytes, and compromised central blood vessels and sinusoids. The lungs showed signs of alveolar inflammation, epithelial exfoliation, debris, and the accumulation of inflammatory cells in alveolar spaces. Lower doses showed uniformly distributed cardiac blood vessels, while higher doses resulted in heart hemorrhages and amorphous exudates. Except for high doses, which significantly elevated specific liver damage indicators, no other levels of Bischofia javanica caused treatment-related mortality or significant alterations in hematological and biochemical parameters. Blood sugar levels remained stable across the dose range. In conclusion, moderate doses of nano-formulated Bischofia javanica leaf extracts can enhance physiological functions positively. However, caution is necessary when contemplating high doses, as they can cause dysfunction or damage vital organ systems.

The potential effect of Alpha-linolenic acid against oxidative stress in non-alcoholic fatty liver disease

Non-alcoholic Fatty Liver Disease (NAFLD) is characterized by fat accumulation in hepatocytes without secondary causes. Oxidative stress plays an important role in forming and progressing from NAFLD to non-alcoholic steatohepatitis (NASH). Alpha-linolenic acid (ALA) is an essential omega-3 (n-3) polyunsaturated fatty acid (PUFA) that has a high antioxidant effect. The purpose of writing this article is to determine the potential of ALA on oxidative stress in NAFLD. This article was made using an online search from 2013 to 2023, and six articles were obtained. From this review, we concluded that ALA has an antioxidant effect that can reduce the impact of oxidative stress in NAFLD, especially in liver tissue, which provides a hepatoprotective effect and regulates gene expression that can reduce oxidative stress in NAFLD.

Prebiotics and Probiotics: Effects on Dyslipidemia and NAFLD/NASH and the Associated Mechanisms of Action.

Non-alcoholic fatty liver disease (NAFLD) is now considered the most common chronic liver disease worldwide. NAFLD is related to changes in lipid metabolism and is characterized by the increase or accumulation of fat in hepatocytes that may progress to nonalcoholic steatohepatitis (NASH), which leads to the appearance of inflammatory processes. Treatment consists of changes in diet, physical activity, and weight control; however, these disorders represent a health problem and require the development of novel alternatives to treatment and prevention. NAFLD/NASH are strongly associated with other disorders, such as metabolic syndrome (MetS); in fact, NAFLD is considered the hepatic manifestation of MetS. These disorders are related to other components of MetS, including dyslipidemia, which is characterized by an imbalance in blood cholesterol and triglyceride levels. Prebiotics and probiotics benefit from treating and preventing several ailments, including liver diseases. Specifically, in dyslipidemia, NAFLD, and NASH, probiotics play a fundamental role in conducting the biotransformation of primary bile acids into secondary bile acids, which generally have important activity as immunomodulators and metabolism regulators. The mechanisms of action of pre and probiotics involve the activity of bile acid receptors, such as FXR and TGR-5, and the events resulting from their activation. Therefore, prebiotics and probiotics may be reasonable options to prevent and treat metabolic- related liver diseases.

Role of Nutrition in the Etiopathogenesis and Prevention of Nonalcoholic Fatty Liver Disease (NAFLD) in a Group of Obese Adults.

Nonalcoholic fatty liver disease (NAFLD) is liver damage characterized by an accumulation of triglycerides in hepatocytes of >5% (due to an alteration of the balance of the lipid metabolism in favour of lipogenesis compared to lipolysis) that is not induced by the consumption of alcohol. The pathology includes simple steatosis and nonalcoholic steatohepatitis, or NASH (steatosis associated with microinflammatory activities), which can evolve in 15% of subjects with hepatic fibrosis to cirrhosis and the development of hepatocellular carcinoma. The aim of this study is to report the role of macro- and micronutrients in the pathogenesis and prevention of NAFLD in obese subjects. A total of 22 obese or overweight patients with hepatic steatosis were monitored periodically, evaluating their eating habits, fasting glycaemia, lipid picture, liver enzymes, anthropometric parameters, nutrition status, liver ultrasound, oxidative stress, and adherence to the Mediterranean diet. A statistical analysis shows a significant positive relationship between total cholesterol and the Mediterranean adequacy index (MAI) (r = -0.57; p = 0.005) and a significant negative relationship between ALT transaminases and the MAI (r = -0.56; p = 0.007). Nutrition and diet are important factors in the pathogenesis and prevention of NAFLD. The dietary model, based on the canons of the Mediterranean diet, prevents and reduces the accumulation of fat in hepatocytes. Therefore, in agreement with other studies in the literature, we can state that a dietary model characterized by foods rich in fibre, carotenoids, polyphenols, ω3 fatty acids, folic acid, and numerous other molecules is inversely correlated with the serum levels of ALT transaminases, an enzyme whose level increases when the liver is damaged and before the most obvious symptoms of organ damage appear.

Hepatic MCPIP1 protein levels are reduced in NAFLD patients and are predominantly expressed in cholangiocytes and liver endothelium

NAFLD is characterized by the excessive accumulation of fat in hepatocytes. NAFLD can range from simple steatosis to the aggressive form called NASH, which is characterized by both fatty liver and liver inflammation. Without proper treatment, NAFLD may further progress to life-threatening complications, such as fibrosis, cirrhosis, or liver failure. Monocyte chemoattractant protein-induced protein 1 (MCPIP1, alias Regnase 1) is a negative regulator of inflammation, acting through the cleavage of transcripts coding for proinflammatory cytokines and the inhibition of NF-κB activity. In this study, we investigated MCPIP1 expression in the liver and peripheral blood mononuclear cells (PBMCs) collected from a cohort of 36 control and NAFLD patients hospitalized due to bariatric surgery or primary inguinal hernia laparoscopic repair. Based on liver histology data (hematoxylin and eosin and Oil Red-O staining), 12 patients were classified into the NAFL group, 19 into the NASH group, and 5 into the control (non-NAFLD) group. Biochemical characterization of patient plasma was followed by expression analysis of genes regulating inflammation and lipid metabolism. The MCPIP1 protein level was reduced in the livers of NAFL and NASH patients in comparison to non-NAFLD control individuals. In addition, in all groups of patients, immunohistochemical staining showed that the expression of MCPIP1 was higher in the portal fields and bile ducts in comparison to the liver parenchyma and central vein. The liver MCPIP1 protein level negatively correlated with hepatic steatosis but not with patient body mass index or any other analyte. The MCPIP1 level in PBMCs did not differ between NAFLD patients and control patients. Similarly, in patients' PBMCs there were no differences in the expression of genes regulating β-oxidation (ACOX1, CPT1A, and ACC1) and inflammation (TNF, IL1B, IL6, IL8, IL10, and CCL2), or transcription factors controlling metabolism (FAS, LCN2, CEBPB, SREBP1, PPARA, and PPARG). We have demonstrated that MCPIP1 protein levels are reduced in NAFLD patients, but further research is needed to investigate the specific role of MCPIP1 in NAFL initiation and the transition to NASH.

Rol kyshkovoi mikrobioty, endotoksemii ta systemnoho zapalennia u patohenezi nealkoholnoi zhyrovoi khvoroby pechinky

Introduction. Currently there are few and contradictory data concerning the influence of intestinal microbiota (IM) disturbances on the nature and severity of inflammatory processes in the liver tissue, the role of microbial metabolites in the activation of steatosis and fibrosis processes in patients with non-alcoholic fatty liver disease (NAFLD). The aim of the study. To clarify the role of intestinal microbiota, endotoxemia and systemic inflammation in the development and progression of nonalcoholic fatty liver disease. Materials and methods. 108 patients with NAFLD were examined, control group included 30 people. Detection of CRP and TNF-alpha levels, endotoxin in blood serum was carried out by the immunoenzymatic method. Determination of IM composition at the level of the main phylotypes was carried out by the method of quantitative polymerase chain reaction in real time. Results. A weak direct correlation between TNF-alpha, CRP and endotoxin with Firmicutes content (F), and an inverse correlation between CRP with Bacteroidetes content (B) was revealed. The dependence of the ratio of main intestinal phyla (F/B) on markers of systemic inflammation in NAFLD patients with different levels of endotoxin was evaluated. In patients with NAFLD, as endotoxin concentration increased, a deeper imbalance of IM was observed. In the group of patients with NAFLD with a high level of endotoxin, the maximum values of the F/B index were observed. Also, the increase in the intestinal permeability of the mucous barrier depended not only on changes in the IM, but also on systemic inflammation. The highest levels of endotoxemia were observed in patients with a high F/B index and increased activity of pro-inflammatory markers. In patients with NAFLD with varying degrees of fatty infiltration of the liver, an imbalance of IM was detected in comparison with the control group. As the degree of steatosis increased in NAFLD patients, an increase in Firmicutes content was observed. The maximum shift in the balance of the main phyla towards a decrease in the relative content of Bacteroidetes and an increase in Firmicutes was determined in patients with 3rd degree of steatosis (p-value less than 0.05). In the group of patients with a low and moderate degree of steatosis, a similar trend of IM disorders was observed, but these changes were insignificant. The relative number of Actinobacteria exposed no differences between the examined patients. The analysis of changes in IM in patients with NAFLD depending on the stage of liver fibrosis revealed no significant differences both from the control group and between groups with different degrees of fibrosis. The obtained data indicate that the imbalance of IM makes a significant contribution to the development of liver steatosis, while other important factors are involved in the formation of fibrosis processes, in particular, inflammation, the activity of intestinal metabolites and regulatory molecules. Conclusions.The imbalance of the intestinal microbiota towards an increase in Firmicutes leads to an increase in the production of intestinal metabolites with subsequent initiation of systemic inflammation, which stimulates the accumulation of fat in hepatocytes, affecting the progression of steatosis and the processes of fibrosis in the liver.

Aqueous extract of Artemisia capillaris improves non-alcoholic fatty liver and obesity in mice induced by high-fat diet.

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases and is a nutritional metabolic disease. Artemisia capillaris (AC) is the above-ground dried part of Artemisia capillaris Thunb. or Artemisia scoparia Waldst. et Kit., a natural medicinal plant with pharmacological effects of heat-clearing and biliary-promoting. In order to evaluate the therapeutic effect of Artemisia capillaris on NAFLD and obesity, experiments were conducted using aqueous extracts of Artemisia capillaris (WAC) to intervene in NAFLD models in vivo and in vitro. In vivo experiments were performed using HFD-fed (high fat diet) C57BL/6 mice to induce NAFLD model, and in vitro experiments were performed using oleic acid to induce HepG2 cells to construct NAFLD cell model. H.E. staining and oil red O staining of liver tissue were used to observe hepatocytes. Blood biochemistry analyzer was used to detect serum lipid levels in mice. The drug targets and mechanism of action of AC to improve NAFLD were investigated by western blotting, qRT-PCR and immunofluorescence. The results showed that C57BL/6 mice fed HFD continuously for 16weeks met the criteria for NAFLD in terms of lipid index and hepatocyte fat accumulation. WAC was able to reverse the elevation of serum lipid levels induced by high-fat diet in mice. WAC promoted the phosphorylation levels of PI3K/AKT and AMPK in liver and HepG2 cells of NAFLD mice, inhibited SREBP-1c expression, reduced TG and lipogenesis, and decreased lipid accumulation. In summary, WAC extract activates PI3K/AKT pathway, reduces SREBP-1c protein expression by promoting AMPK phosphorylation, and decreases fatty acid synthesis and TG content in hepatocytes. AC can be used as a potential health herb to improve NAFLD and obesity.