Nonalcoholic Steatohepatitis In Nonalcoholic Fatty Liver Disease Patients Research Articles

Association between serum sex hormone-binding globulin and non-alcoholic steatohepatitis

Objective: To investigate the association between serum sex hormone-binding globulin (SHBG) and non-alcoholic steatohepatitis (NASH). Methods: In this cross-sectional study, a total of 371 middle-aged and young obese patients who were hospitalized and underwent liver puncture in Nanjing Drum Tower Hospital from January 2016 to April 2021 were included. The population was divided into control group (n=43) and non-alcoholic fatty liver disease (NAFLD) group (n=328) based on the non-alcoholic fatty liver disease activity score. Subjects in NAFLD group were further divided into non-alcoholic fatty liver (NAFL) (n=60), uncertain-NASH (n=172), and NASH (n=96). Serum SHBG was tested in patients with NAFLD who were divided into three subgroups according to tertiles. The liver pathological characteristics in different SHBG level subgroups were compared. The risk factors of NASH were analyzed by logistic regression. The prediction model of NASH noninvasive diagnosis was established by forward stepwise regression, and the diagnostic value of non-invasive model for NASH was evaluated by receiver operating characteristic (ROC) curve. Results: The median age in patients were (32±10) years old with a body mass index of (39.16±6.58) kg/m², including 236 females (63.6%). Serum SHBG level [M (Q1, Q3)] in NAFLD group was significantly lower than that in control group [16.90 (11.43, 23.00) vs. (23.45 (15.40, 31.22) mmol/L, P<0.05], and progressively diminished in NAFL, uncertain-NASH and NASH subgroups [(22.24±10.47), (20.57±19.58), (15.80±8.74) mmol; P for trend<0.05]. Compared with the high-leveled SHBG subgroup, the steatosis score (2.09±0.80 vs. 1.51±0.72, P<0.01) and lobular inflammation score (1.10±0.68 vs. 0.85±0.68, P<0.05) were significantly higher in the low-leveled SHBG group. Multivariate logistic regression analysis indicated that lower serum SHBG level was an independent risk factor for NASH (OR=2.527, 95%CI: 1.296 to 4.928, P<0.05). The area under ROC curve of SHBG combined with aspartate aminotransferase in predicting NASH in NAFLD patients was 0.752 (95%CI: 0.696 to 0.809). Conclusion: Low serum SHBG level is associated with NASH.

Non-Invasive Detection of Fibrotic NASH in NAFLD Patients with Low or Intermediate FIB-4.

Background: Non-alcoholic steatohepatitis (NASH) and fibrosis are the main prognostic factors in non-alcoholic fatty liver disease (NAFLD). The FIB-4 score has been suggested as an initial test for the exclusion of progressed fibrosis. However, increasing evidence suggests that also NASH patients with earlier fibrosis stages are at risk of disease progression, emphasizing the need for improved non-invasive risk stratification. Methods: We evaluated whether the apoptosis biomarker M30 can identify patients with fibrotic NASH despite low or intermediate FIB-4 values. Serum M30 levels were assessed by ELISA, and FIB-4 was calculated in an exploration (n = 103) and validation (n = 100) cohort of patients with histologically confirmed NAFLD. Results: The majority of patients with low FIB-4 (cut-off value < 1.3) in the exploration cohort revealed increased M30 levels (>200 U/L) and more than 80% of them had NASH, mostly with fibrosis. NASH was also detected in all patients with intermediate FIB-4 (1.3 to 2.67) and elevated M30, from which ~80% showed fibrosis. Importantly, in the absence of elevated M30, most patients with FIB-4 < 1.3 and NASH showed also no fibrosis. Similar results were obtained in the validation cohort. Conclusions: The combination of FIB-4 with M30 enables a more reliable identification of patients at risk for progressed NAFLD and might, therefore, improve patient stratification.

Association of Serum Bilirubin With Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis.

ObjectiveMetabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD) are the leading chronic diseases worldwide. There are still many controversies about the association between serum bilirubin and MetS or NAFLD. This study aims to evaluate the association of serum total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL) with MetS and NAFLD.MethodsMultiple databases were searched for relevant studies until November 2021. Randomized controlled trials, cross-sectional and cohort studies evaluating the association between serum bilirubin levels and MetS or NAFLD were included.ResultsTwenty-four cross-sectional and cohort studies with 101, 517 participants were finally analyzed. Fifteen studies and 6 studies evaluated the association between bilirubin and MetS or NAFLD in health screening population, respectively, while 3 studies evaluated the association between bilirubin and non-alcoholic steatohepatitis (NASH) in NAFLD patients. Random effect model analysis showed the inverse association between TBIL and MetS in male (95%CI=0.71-0.96) and gender-neutral (95%CI=0.61-0.91) group. However, no significant association was found in females. Notably, the inverse association between DBIL and MetS was noticed in male (95%CI=0.36-0.75), female (95%CI=0.16-0.58) and gender-neutral population (95%CI=0.67-0.92). IBIL level was inversely associated with MetS in females (95%CI=0.52-0.96), whereas no statistical correlation presented in males. TBIL was not statistically correlated with NAFLD in gender-neutral or male subgroup. Similarly, there were no association between DBIL or IBIL and NAFLD in gender-neutral subgroup. However, the negative correlation between DBIL and NAFLD existed in males (95%CI=0.76-0.96). In NAFLD patients, IBIL analysis showed an inverse association with NASH (95%CI=0.01-0.12).ConclusionSerum TBIL and DBIL levels, especially DBIL levels, assume an inverse correlation with MetS in healthy population. Serum IBIL is inversely associated with the onset and degree of NASH in NAFLD patients. Exogenous bilirubin supplement may be a potential strategy to assist in lowering the risk of developing MetS and NAFLD.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42021293349

Ultrasonographic index for the diagnosis of non-alcoholic steatohepatitis in patients with non-alcoholic fatty liver disease.

Liver biopsy is a gold standard for the diagnosis of non-alcoholic steatohepatitis (NASH), but has several disadvantages including invasiveness, high cost, and sampling error. Ultrasonography (US) is a noninvasive imaging modality widely used in non-alcoholic fatty liver disease (NAFLD) patients. This study aimed: (I) to assess the feasibility of US in the prediction of NASH and (II) to develop various US indices combining US parameters and laboratory data for the detection of NASH in NAFLD patients and to compare the diagnostic performance of them. Sixty patients who underwent liver biopsy, gray-scale US [hepatorenal index (HRI) and shear-wave elastography (SWE)], and Fibroscan [controlled attenuation parameter (CAP) and transient elastography (TE)] for the evaluation of NASH were included. Patients were classified according to the NAFLD Activity Score (NAS) into the NASH (NAS ≥5) and non-NASH (NAS <5) groups. The diagnostic performance of HRI, CAP, SWE, TE, and laboratory data for grading steatosis, lobular inflammation, ballooning degeneration, and fibrosis was evaluated. After the identification of laboratory data that were independently associated with NASH through univariable and multivariable logistic regression analyses, various US indices were developed by combining US parameters with or without these laboratory data. The diagnostic performance of the US indices was assessed with obtaining area under the curve (AUC) and compared using DeLong test. Twenty-five NASH and 35 non-NASH patients were included. The mean AUCs for grading steatosis were 0.871 using HRI and 0.583 using CAP. The mean AUCs for grading fibrosis and ballooning degeneration were 0.777 and 0.729 using SWE and 0.830 and 0.708 using TE, respectively. Aspartate aminotransferase (AST) was the only significant laboratory data associated with NASH (OR, 1.019; P=0.032). Using AST, the mean AUCs for grading lobular inflammation and ballooning degeneration were 0.712 and 0.775, respectively. Among various US indices, the index consisting of gray-scale US parameters (SWE and HRI) and AST showed the best diagnostic performance for the detection of NASH in NAFLD patients (AUC =0.806). The index combining gray-scale US parameters and AST is useful for the detection of NASH and may be used to exclude the need for liver biopsy in NAFLD patients.

PPARGC1A rs8192678 G>A polymorphism affects the severity of hepatic histological features and nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease.

BACKGROUNDThe association between PPARGC1A rs8192678 and nonalcoholic fatty liver disease (NAFLD) requires further confirmation. In addition, it is still unknown whether PPARGC1A rs8192678 is associated with hepatic histological features in NAFLD in the Chinese population. AIMTo investigate the interaction between PPARGC1A rs8192678 and nonalcoholic steatohepatitis (NASH), and whether this polymorphism is associated with hepatic histological features. METHODSFifty-nine patients with liver biopsy-proven NAFLD and 93 healthy controls were recruited to a cohort representing the Chinese Han population. The SAF (steatosis, activity, and fibrosis) scoring system was used for hepatic histopathological evaluation. The polymorphisms of PPARGC1A rs8192678 and patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 were genotyped. The intrahepatic mRNA expression of PPARGC1A was evaluated by real-time polymerase chain reaction.RESULTSThirty-seven patients with NAFLD had NASH, of which 12 were nonobese. The PPARGC1A rs8192678 risk A allele (carrying GA and AA genotypes) had the lowest P value in the dominant model; the odds ratio (OR) for NAFLD was 2.321 [95% confidence interval (CI): 1.121-4.806]. After adjusting for age, sex, and the PNPLA3 rs738409 risk G allele, the PPARGC1A rs8192678 A allele was a risk factor for NAFLD (OR 2.202, 95%CI: 1.030-4.705, P = 0.042). The genetic analysis showed that patients with NAFLD, moderate-to-severe steatosis (S2-3), and Activity 2-4 (A ≥ 2) were more likely to carry A in PPARGC1A rs8192678 (OR 5.000, 95%CI: 1.343-18.620, P = 0.012; and OR 4.071, 95%CI: 1.076-15.402, P = 0.031). The multivariate logistic regression analysis showed that PPARGC1A rs8192678 risk A allele was also independently associated with S2-3, A ≥ 2, and NASH (OR 6.190, 95%CI: 1.508-25.410, P = 0.011; OR 4.506, 95%CI 1.070-18.978, P = 0.040; and OR 6.337, 95%CI: 1.135-35.392, P = 0.035, respectively) after adjusting for age, sex, body mass index, and PNPLA3 rs738409 risk G allele. The results also showed that this polymorphism was associated with nonobese NASH (OR 22.000, 95%CI: 1.540-314.292, P = 0.021). The intrahepatic expression of PPARGC1A mRNA was significantly lower in the group of patients who carried the risk A allele (P = 0.014). CONCLUSIONThe PPARGC1A rs8192678 risk A allele is associated with NAFLD, and with S2-3, A ≥ 2 and NASH in NAFLD patients, independent of PNPLA3 rs738409, and may be associated with nonobese NASH.

Multiparametric MR Index for the Diagnosis of Non-Alcoholic Steatohepatitis in Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic steatohepatitis (NASH) is a complex disease consisting of various components including steatosis, lobular inflammation, and ballooning degeneration, with or without fibrosis. Therefore, it is difficult to diagnose NASH with only one imaging modality. This study was aimed to evaluate the feasibility of magnetic resonance imaging (MRI) for predicting NASH and to develop a non-invasive multiparametric MR index for the detection of NASH in non-alcoholic fatty liver disease (NAFLD) patients. This prospective study included 47 NAFLD patients who were scheduled to undergo or underwent ultrasound-guided liver biopsy within 2 months. Biopsy specimens were graded as NASH or non-NASH. All patients underwent non-enhanced MRI including MR spectroscopy (MRS), MR elastography (MRE), and T1 mapping. Diagnostic performances of MRS, MRE, and T1 mapping for grading steatosis, activity, and fibrosis were evaluated. A multiparametric MR index combining fat fraction (FF), liver stiffness (LS) value, and T1 relaxation time was developed using linear regression analysis. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of the newly devised MR index. Twenty NASH patients and 27 non-NASH patients were included. Using MRS, MRE, and T1 mapping, the mean areas under the curve (AUCs) for grading steatosis, fibrosis, and activity were 0.870, 0.951, and 0.664, respectively. The multiparametric MR index was determined as 0.037 × FF (%) + 1.4 × LS value (kPa) + 0.004 × T1 relaxation time (msec) −3.819. ROC curve analysis of the MR index revealed an AUC of 0.883. The cut-off value of 6 had a sensitivity of 80.0% and specificity of 85.2%. The multiparametric MR index combining FF, LS value, and T1 relaxation time showed high diagnostic performance for detecting NASH in NAFLD patients.

The Serum Biomarkers of Cardiovascular Disease Are Elevated in Patients With Non-alcoholic Fatty Liver Disease (NAFLD) With Advanced Fibrosis and Histologically-Proven Non-alcoholic Steatohepatitis (NASH): 2017 Presidential Poster Award

Introduction: NAFLD is associated with increased risk for cardiovascular disease (CVD) and CV mortality. The progressive NAFLD or NASH and especially those with hepatic fibrosis are at risk for mortality. Given that CVD is the top cause of death in NAFLD/NASH, it is possible that these subjects may share the same pathogenic environment as those with CVD. Recently, N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) and osteopontin (OPN) have been shown to be associated with CVD. Our aim was to see if these biomarkers are associated with the aggressive form of NAFLD such as NASH or significant hepatic fibrosis. Methods: The study cohort included 170 biopsy-proven NAFLD subjects who were prospectively consented and enrolled. Liver biopsies were assessed by the study hepatopathologists and graded for degree of steatosis (0-3), necroinflammation and fibrosis (0-4). Sera samples were frozen from the time of biopsy were used to measure serum levels of OPN (pg/mL), NT-proBNP (pg/mL) and adiponectin (ng/mL) using MILIPLEX® MAP assays by Luminex®. Results: Histologic NASH was seen in 52% of NAFLD and % had stage 2 or higher fibrosis. The median OPN levels were higher in NASH as compared to steatosis alone (3109 vs. 2251, p < 0.01). Additionally, adiponectin levels were lower in NASH as compared to hepatic steatosis by using quartile 4 as cutoff point (34% vs. 53%, p < 0.05). Furthermore, as compared to fibrosis stage (0-1) (2598), the median OPN levels were higher in patients with advance fibrosis (fibrosis stage ≥2) (3360, p < 0.01) as well as bridging fibrosis (3242 vs 2598, p < 0.05). Also, higher levels of OPN positively correlated with AST (r=0.17; p=0.03) and serum ferritin (r=0.28; p=0.03), while adiponectin only positively correlated with HDL (r=0.33; p < 0.01). Histologically, serum OPN significantly correlated with the presence of polymorphonuclear (r=0.24; p < 0.01), and Mallory-Denk body (r=0.28; p < 0.01) in the liver biopsy. In the multivariate analysis, serum OPN was independently associated with presence of histologic NASH in NAFLD patients (OR 2.9 [95% CI 1.2-6.7]). In contrast NT-proBNP was not detectable in both groups. Conclusion: Increased serum levels of OPN seem to be associated with presence of NASH and advanced hepatic fibrosis in patients with NAFLD. Further studies are needed to validate these findings and to determine if serum OPN can also predict presence of development of CVD in subjects with NAFLD.

A novel model using mean platelet volume and neutrophil to lymphocyte ratio as a marker of nonalcoholic steatohepatitis in NAFLD patients: multicentric study.

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of progressive and chronic liver injury. Mean platelet volume (MPV) and the neutrophil-lymphocyte ratio (N/L ratio) may be considered cheap and simple markers of inflammation in many disorders. We aimed to investigate the clinical utility of MPV and the N/L ratio to predict fibrosis in NAFLD patients and the presence of nonalcoholic steatohepatitis (NASH). A total of 873 patients with biopsy-proven NAFLD and 150 healthy controls were included. Patients were divided into two groups: non-NASH group (n=753) and NASH group (n=120). Liver biopsy, MPV, lymphocyte, and neutrophil counts were registered; the N/L ratio was calculated. Proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) were measured by an ELISA. NASH patients had higher MPV compared with non-NASH patients (10.9±1.8 and 9.5±1.6 fl, respectively, P<0.001). MPV correlated positively with the NAFLD activity score, proinflammatory cytokines, and C-reactive protein (CRP) (P<0.001). Patients with advanced fibrosis (F3-4) had increased MPV (11.3±0.9 fl) compared with patients with early fibrosis (F1-2) (10.2±0.8 fl, P<0.001). NASH patients had an increased N/L ratio compared with non-NASH cases (2.6±1.1 and 1.9±0.7 fl, respectively, P<0.001). The N/L ratio correlated positively with NAFLD activity score, proinflammatory cytokines, and CRP (P<0.001). In addition, patients with advanced fibrosis (F3-4) had an N/L ratio (2.5±1.1) comparable with that of patients with early fibrosis (F1-2) (1.8±0.9) (P<0.001). MPV and the N/L ratio were elevated in NASH patients versus non-NASH cases, and in patients with advanced fibrosis (F3-4) versus early fibrosis (F1-2). They can be used as noninvasive novel markers to predict advanced disease.

Cytokeratin 18, Alanine Aminotransferase, Platelets and Triglycerides Predict the Presence of Nonalcoholic Steatohepatitis

BackgroundNonalcoholic fatty liver disease (NAFLD) is one of the critical public health problems in China. The full spectrum of the disease ranges from simple steatosis and nonalcoholic steatohepatitis (NASH) to cirrhosis and hepatocellular carcinoma(HCC). The infiltration of inflammatory cells characterizes NASH. This characteristic contributes to the progression of hepatitis, fibrosis, cirrhosis, and HCC. Therefore, distinguishing NASH from NAFLD is crucial.Objective and MethodsNinety-five patients with NAFLD, 44 with NASH, and 51 with non-NASH were included in the study to develop a new scoring system for differentiating NASH from NAFLD. Data on clinical and biological characteristics, as well as blood information, were obtained. Cytokeratin-18 (CK-18) fragments levels were measured using an enzyme-linked immunosorbant assay.ResultsSeveral indexes show significant differences between the two groups, which include body mass index (BMI), waist-on-hip ratio (WHR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (γ-GT), platelets, uric acid (UA), hs-C-reactive protein (hs-CRP), triglycerides (TG), albumin (ALB), and CK-18 fragments (all P < 0.05). The CK-18 fragment levels showed a significant positive correlation with steatosis severity, ballooning, lobular inflammation, and fibrosis stage (all P < 0.05). Therefore, a new model that combines ALT, platelets, CK-18 fragments, and TG was established by logistic regression among NAFLD patients. The AUROC curve in predicting NASH was 0.920 (95% CI: 0.866 - 0.974, cutoff value = 0.361, sensitivity = 89%, specificity = 86%, positive predictive value = 89%, negative predictive value = 89%). ConclusionThe novel scoring system may be considered as a useful model in predicting the presence of NASH in NAFLD patients.

The Involvement of Chronic Mental and Physical Stress on the Liver Steatosis and Fibrosis

Background: Nonalcoholic fatty liver disease (NAFLD), which is the liver's manifection of metabolic syndrome, includes a wide spectrum of liver diseases, ranging from pure fatty liver to nonalcoholic steatohepatitis (NASH). A crucial event in the initiation of NASH seems to involve early lipid accumulation and lipid peroxidation in the hepatocytes, followed by kupffer cells (KC) and hepatic stellate cells activation. However, the mechanism of NASH progression is still unknown. Recently, because some study groups have reported that NASH patients have chronic stress, the association between stress and NASH progression has been suspected. Neuroendocrine mediators produced from hypothalamic pituitary adrenal axis, such as cortisol or norepinephrine (NE), have been known to affect immune cells. It is possible that KC affected by stress induced mediators are involved in the NADH initiation. In this study, we investigated the involvement of chronic stress on NASH progression with a murine restraint stress (RST) model. Methods: Five weeks old male C57/BL6j mice were used in this study. Mice were fed the methionine and choline deficient (MCD) diet or control diet for 8 weeks. RST was loaded on mice with placing in well-ventilated 50 ml conical tubes for 6 hrs twice a week. In some experiments, clodronate lyposomes were administrated in mice with injection to deplete KC. Mice were randomly divided into six groups : (1) MCD diet only (n=9), (2) MCD diet and RST (n=7), (3) MCD diet, RST and KC depletion (n=7), (4) control diet only (n=5), (5) control diet and RST (n=8), (6) control diet, RST and KC depletion (n=8). After 8 weeks, the degrees of steatohepatitis were histologically analyzed in all groups. Results: By loading RST, serum cortisol (1.27±0.29 vs. 1.97±0.35, p < 0.05) and hyaluronic acid (113.3±36.3 vs. 191.5±77.9, p < 0.05) were elevated, and liver steatosis was occurred in mice fed control diet. Next, the administration of MCD diet was induced steatohepatitis, and serum ALT, cortisol, hyaluronic acid (106±84, 2.3±0.3, 256.3±78.9 in MCD vs. 119±64, 2.5±0.5, 293.3±197.9 in MCD plus RST) and steatohepatitis induce by MCD diet were aggravated by loading RST. However, when mice were treated with clodronate lyposomes to deplete KC, the degree of liver steatosis and fibrosis were decreased in mice fed MCD diet or loaded RST. Conclusion: M2 macrophages, which are induced by cortisol or IL-10, have known to produce TGF-β. These results suggest that chronic stress may be involved in the progression of NASH through the alternative activation of KC. Reduction of mental or physical stress may be decreased the risk of NASH in NAFLD patients.

Analysis of Abnormal Iron Metabolism and Efficacy of Iron Reduction Therapy in Patients With Nonalcoholic Steatohepatitis

Background: Nonalcoholic fatty liver disease (NAFLD), which is the liver's manifection of metabolic syndrome, includes a wide spectrum of liver diseases, ranging from pure fatty liver to nonalcoholic steatohepatitis (NASH). A crucial event in the initiation of NASH seems to involve early lipid accumulation and lipid peroxidation in the hepatocytes, followed by kupffer cells (KC) and hepatic stellate cells activation. However, the mechanism of NASH progression is still unknown. Recently, because some study groups have reported that NASH patients have chronic stress, the association between stress and NASH progression has been suspected. Neuroendocrine mediators produced from hypothalamic pituitary adrenal axis, such as cortisol or norepinephrine (NE), have been known to affect immune cells. It is possible that KC affected by stress induced mediators are involved in the NADH initiation. In this study, we investigated the involvement of chronic stress on NASH progression with a murine restraint stress (RST) model. Methods: Five weeks old male C57/BL6j mice were used in this study. Mice were fed the methionine and choline deficient (MCD) diet or control diet for 8 weeks. RST was loaded on mice with placing in well-ventilated 50 ml conical tubes for 6 hrs twice a week. In some experiments, clodronate lyposomes were administrated in mice with injection to deplete KC. Mice were randomly divided into six groups : (1) MCD diet only (n=9), (2) MCD diet and RST (n=7), (3) MCD diet, RST and KC depletion (n=7), (4) control diet only (n=5), (5) control diet and RST (n=8), (6) control diet, RST and KC depletion (n=8). After 8 weeks, the degrees of steatohepatitis were histologically analyzed in all groups. Results: By loading RST, serum cortisol (1.27±0.29 vs. 1.97±0.35, p < 0.05) and hyaluronic acid (113.3±36.3 vs. 191.5±77.9, p < 0.05) were elevated, and liver steatosis was occurred in mice fed control diet. Next, the administration of MCD diet was induced steatohepatitis, and serum ALT, cortisol, hyaluronic acid (106±84, 2.3±0.3, 256.3±78.9 in MCD vs. 119±64, 2.5±0.5, 293.3±197.9 in MCD plus RST) and steatohepatitis induce by MCD diet were aggravated by loading RST. However, when mice were treated with clodronate lyposomes to deplete KC, the degree of liver steatosis and fibrosis were decreased in mice fed MCD diet or loaded RST. Conclusion: M2 macrophages, which are induced by cortisol or IL-10, have known to produce TGF-β. These results suggest that chronic stress may be involved in the progression of NASH through the alternative activation of KC. Reduction of mental or physical stress may be decreased the risk of NASH in NAFLD patients.

Glucagon-Like Peptide-1 (GLP-1) Analogue Inhibited Hepatic Inflammation in Nonalcoholic Steatohepatitis (NASH)

Background: Nonalcoholic fatty liver disease (NAFLD), which is the liver's manifection of metabolic syndrome, includes a wide spectrum of liver diseases, ranging from pure fatty liver to nonalcoholic steatohepatitis (NASH). A crucial event in the initiation of NASH seems to involve early lipid accumulation and lipid peroxidation in the hepatocytes, followed by kupffer cells (KC) and hepatic stellate cells activation. However, the mechanism of NASH progression is still unknown. Recently, because some study groups have reported that NASH patients have chronic stress, the association between stress and NASH progression has been suspected. Neuroendocrine mediators produced from hypothalamic pituitary adrenal axis, such as cortisol or norepinephrine (NE), have been known to affect immune cells. It is possible that KC affected by stress induced mediators are involved in the NADH initiation. In this study, we investigated the involvement of chronic stress on NASH progression with a murine restraint stress (RST) model. Methods: Five weeks old male C57/BL6j mice were used in this study. Mice were fed the methionine and choline deficient (MCD) diet or control diet for 8 weeks. RST was loaded on mice with placing in well-ventilated 50 ml conical tubes for 6 hrs twice a week. In some experiments, clodronate lyposomes were administrated in mice with injection to deplete KC. Mice were randomly divided into six groups : (1) MCD diet only (n=9), (2) MCD diet and RST (n=7), (3) MCD diet, RST and KC depletion (n=7), (4) control diet only (n=5), (5) control diet and RST (n=8), (6) control diet, RST and KC depletion (n=8). After 8 weeks, the degrees of steatohepatitis were histologically analyzed in all groups. Results: By loading RST, serum cortisol (1.27±0.29 vs. 1.97±0.35, p < 0.05) and hyaluronic acid (113.3±36.3 vs. 191.5±77.9, p < 0.05) were elevated, and liver steatosis was occurred in mice fed control diet. Next, the administration of MCD diet was induced steatohepatitis, and serum ALT, cortisol, hyaluronic acid (106±84, 2.3±0.3, 256.3±78.9 in MCD vs. 119±64, 2.5±0.5, 293.3±197.9 in MCD plus RST) and steatohepatitis induce by MCD diet were aggravated by loading RST. However, when mice were treated with clodronate lyposomes to deplete KC, the degree of liver steatosis and fibrosis were decreased in mice fed MCD diet or loaded RST. Conclusion: M2 macrophages, which are induced by cortisol or IL-10, have known to produce TGF-β. These results suggest that chronic stress may be involved in the progression of NASH through the alternative activation of KC. Reduction of mental or physical stress may be decreased the risk of NASH in NAFLD patients.