Opposing effects of oestradiol and progesterone on intracellular pathways and activation processes in the oxidative stress induced activation of cultured rat hepatic stellate cells

Role of the type 3 cytokines IL-17 and IL-22 in modulating metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) comprises a spectrum of liver diseases that span simple steatosis, metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis and may progress to cirrhosis and cancer. The pathogenesis of MASLD is multifactorial and is driven by environmental, genetic, metabolic and immune factors. This review will focus on the role of the type 3 cytokines IL-17 and IL-22 in MASLD pathogenesis and progression. IL-17 and IL-22 are produced by similar adaptive and innate immune cells such as Th17 and innate lymphoid cells, respectively. IL-17-related signaling is upregulated during MASLD resulting in increased chemokines and proinflammatory cytokines in the liver microenvironment, enhanced recruitment of myeloid cells and T cells leading to exacerbation of inflammation and liver disease progression. IL-17 may also act directly by activating hepatic stellate cells resulting in increased fibrosis. In contrast, IL-22 is a pleiotropic cytokine with a dominantly protective signature in MASLD and is currently being tested as a therapeutic strategy. IL-22 also exhibits beneficial metabolic effects and abrogates MASH-related inflammation and fibrosis development via inducing the production of anti-oxidants and anti-apoptotic factors. A sex-dependent effect has been attributed to both cytokines, most importantly to IL-22 in MASLD or related conditions. Altogether, IL-17 and IL-22 are key effectors in MASLD pathogenesis and progression. We will review the role of these two cytokines and cells that produce them in the development of MASLD, their interaction with host factors driving MASLD including sexual dimorphism, and their potential therapeutic benefits.

Intestinal microbiota promoted NiONPs-induced liver fibrosis via effecting serum metabolism

Nickel oxide nanoparticles (NiONPs) are toxic heavy metal compounds that induce liver fibrosis and metabolic disorders. Current research shows that the intestinal microbiota regulates liver metabolism through the gut-liver axis. However, it is unclear whether NiONPs affect the intestinal microbiota and the relationship between microbiota and liver metabolic disorders. Therefore, in this study, we established liver fibrosis model by administering 0.015, 0.06 and 0.24 mg/mL NiONPs through tracheal instillation twice a week for 9 weeks in rats, then we collected serum and fecal sample for whole metabolomics and metagenomic sequencing. As the result of sequencing, we screened out seven metabolites (beta-D-glucuronide, methylmalonic acid, linoleic acid, phosphotidylcholine, lysophosphatidylinositol, docosapentaenoic acid and progesterone) that related to functional alterations (p < 0.05), and obtained a decrease of probiotics abundances (p < 0.05) as well as a variation of the microbiota enzyme activity (p < 0.05), indicating that NiONPs inhibited the proliferation of probiotics. As the result of correlation analysis, we found a positive correlation between differential metabolites and probiotics, such as lysophosphatidylinositol was positively correlated with Desulfuribacillus, Jeotgallibacillus and Rummeliibacillus (p < 0.05). We also found that differential metabolites had correlations with differential proteins and enzymes of intestinal microbiota, such as glucarate dehydratase, dihydroorotate dehydrogenase and acetyl-CoA carboxylase (p < 0.05). Finally, we screened six metabolic pathways with both differential intestinal microbiota enzymes and metabolites were involved, such as pentose and glucuronate interconversions, and linoleic acid metabolism. In vitro experiments showed that NiONPs increased the transcriptional expression of Col1A1 in LX-2 cells, while reducing the mRNA expression of serine/threonine activators, acetyl coenzyme carboxylase, and lysophosphatidylinositol synthase, and short chain fatty acid sodium butyrate can alleviate these variation trends. The results proved that the intestinal microbiota enzyme systems were associated with serum metabolites, suggesting that the disturbance of intestinal microbiota and reduction of probiotics promoted the occurrence and development of NiONPs-induced liver fibrosis by affecting metabolic pathways.

Positive Progesterone Receptor Expression in Meningioma May Increase the Transverse Relaxation: First Prospective Clinical Trial Using Single-Shot Ultrafast T2 Mapping

RATIONALE AND OBJECTIVES

This project aims to investigate the diagnostic performance of multiple overlapping-echo detachment imaging (MOLED) technique-derived transverse relaxation time (T2) maps in predicting progesterone receptor (PR) and S100 expression in meningiomas.

MATERIALS AND METHODS

63 meningioma patients were enrolled from October 2021 to August 2022, who underwent a complete routine magnetic resonance imaging and T2 MOLED, which can characterize the whole brain transverse relaxation time within 32 seconds in a single scan. After the surgical resection of meningiomas, the expression levels of PR and S100 were determined by an experienced pathologist using immunohistochemistry techniques. Histogram analysis was performed in tumor parenchyma based on the parametric maps. Independent t test and Mann-Whitney U test were applied for the comparison of histogram parameters between different groups, with a significance level of P < .05. Logistic regression and receiver operating characteristic (ROC) analysis with 95% confidence interval were conducted for the diagnostic efficiency evaluation.

RESULTS

PR-positive group had significantly elevated T2 histogram parameters (P = .001-.049) compared to the PR-negative group. The multivariate logistic regression model with T2 showed the highest area under the ROC curve (AUC) for predicting PR expression (AUC=0.818). Additionally, the multivariate model also had the best diagnostic performance for predicting meningioma S100 expression (AUC=0.768).

CONCLUSION

The MOLED technique-derived T2 maps can distinguish PR and S100 status in meningiomas preoperatively.

Predisposing factors for advanced liver fibrosis in patients with sickle cell disease

Sickle cell disease (SCD) is one of the most common monogenic disorders worldwide and liver complications are common in this group of patients. Our study aims to highlight the prevalence of chronic liver complications and the main predisposing factors for advanced liver fibrosis in SCD patients. For this purpose, 219 patients from eight Thalassemia and Sickle Cell Units across Greece enrolled in our study and history of liver related disease complications was recorded, as well as a full laboratory and imaging analysis concerning their liver function. 13.6% of the patients had advanced liver fibrosis. The presence of liver fibrosis was significantly correlated with advanced age, male gender, cholelithiasis and higher LDH, γ-GT, INR, direct and indirect bilirubin levels. These patients had exhibited significantly more episodes of liver crises and acute intrahepatic cholestasis. No correlation was observed with right heart failure or previous viral hepatitis. Patients with advanced liver fibrosis were receiving a more intensive transfusion therapy for a longer period of time and had higher Liver Iron Concentration levels. Our study shows that liver complications and cirrhosis is a significant cause of morbidity in patients with SCD and it is primarily associated with intravascular hemolysis and vaso-occlusive phenomena and secondarily with iron overload.

Remodeling liver microenvironment by L-arginine loaded hollow polydopamine nanoparticles for liver cirrhosis treatment

Liver cirrhosis is a liver disease with a high mortality rate worldwide, and antifibrotic drugs are commonly used clinically to alleviate the symptoms, but there are still many challenges. Many studies have shown that excessive reactive oxygen species (ROS) in the microenvironment of liver lesions is an important factor leading to the development of liver cirrhosis. Herein, a nanomedicine-mediated antioxidant therapy was utilized to remodel liver microenvironment and hence reverse the process of cirrhosis from the root. Firstly, L-arginine (L-Arg) loaded and pPB peptide modified PEGylated hollow polydopamine (HPDA) nanoparticles (L-Arg@HPDA-PEG-pPB, L@HPp) were prepared successfully. The in vitro and in vivo experiment showed that L@HPp significantly inhibited oxidative stress and inflammatory reaction, reduced the activation of hepatic stellate cells (HSCs), inhibited the pro-fibrosis molecular pathway, and reduced the deposition of extracellular matrix (ECM), thereby effectively inhibiting liver fibrosis. The pPB peptide modification increased the targeting effect to HSCs. In addition, the oxidative microenvironment in liver cirrhosis promoted the transformation of the loaded L-Arg to nitric oxide (NO), and the latter one caused vascular dilation and further relieved portal hypertension, a typical complication of liver cirrhosis. Therefore, L@HPp had a good prospect of clinical application in the treatment of liver cirrhosis and its complications.

Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones

The prevalence of non-alcoholic fatty liver disease (NAFLD) differs between various stages of the female lifespan. The aim of this review is to summarize current evidence on the association of NAFLD and circulating sex hormones and to explore the pathogenesis of NAFLD within the context of (1) sex hormone changes during the reproductive, post-reproductive female life and beyond and (2) the in vitro and in vivo evidence on pharmacological modulation in women on menopausal hormone treatment (MHT) or endocrine therapy after breast cancer. The fluctuation in estrogen concentrations, the relative androgen excess, and the age-related reduction in sex hormone-binding globulin are related to increased NAFLD risk. Moreover, the peri-menopausal changes in body composition and insulin resistance might contribute to the increased NAFLD risk. Whether MHT prevents or improves NAFLD in this population remains an open question. Studies in women with breast cancer treated with tamoxifen or non-steroidal aromatase inhibitors point to their adverse effects on NAFLD development, although a more pronounced effect of tamoxifen is reported. Future studies focusing on the underlying pathogenesis should identify subgroups with the highest risk of NAFLD development and progression into more aggressive forms, as well as elucidate the role of hormone therapies, such as MHT.

Transcriptome changes in stages of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the United States and globally. The currently understood model of pathogenesis consists of a ‘multiple hit’ hypothesis in which environmental and genetic factors contribute to hepatic inflammation and injury.

AIM

To examine the genetic expression of NAFLD and non-alcoholic steatohepatitis (NASH) tissue samples to identify common pathways that contribute to NAFLD and NASH pathogenesis.

METHODS

We employed the Search Tag Analyze Resource for Gene Expression Omnibus platform to search the The National Center for Biotechnology Information Gene Expression Omnibus to elucidate NAFLD and NASH pathology. For NAFLD, we conducted meta-analysis of data from 58 NAFLD liver biopsies and 60 healthy liver biopsies; for NASH, we analyzed 187 NASH liver biopsies and 154 healthy liver biopsies.

RESULTS

Our results from the NAFLD analysis reinforce the role of altered metabolism, inflammation, and cell survival in pathogenesis and support recently described contributors to disease activity, such as altered androgen and long non-coding RNA activity. The top upstream regulator was found to be sterol regulatory element binding transcription factor 1 (SREBF1), a transcription factor involved in lipid homeostasis. Downstream of SREBF1, we observed upregulation in CXCL10, HMGCR, HMGCS1, fatty acid binding protein 5, paternally expressed imprinted gene 10, and downregulation of sex hormone-binding globulin and insulin-like growth factor 1. These molecular changes reflect low-grade inflammation secondary to accumulation of fatty acids in the liver. Our results from the NASH analysis emphasized the role of cholesterol in pathogenesis. Top canonical pathways, disease networks, and disease functions were related to cholesterol synthesis, lipid metabolism, adipogenesis, and metabolic disease. Top upstream regulators included pro-inflammatory cytokines tumor necrosis factor and IL1B, PDGF BB, and beta-estradiol. Inhibition of beta-estradiol was shown to be related to derangement of several cellular downstream processes including metabolism, extracellular matrix deposition, and tumor suppression. Lastly, we found riciribine (an AKT inhibitor) and ZSTK-474 (a PI3K inhibitor) as potential drugs that targeted the differential gene expression in our dataset.

CONCLUSION

In this study we describe several molecular processes that may correlate with NAFLD disease and progression. We also identified ricirbine and ZSTK-474 as potential therapy.

The Hepatoprotective and Hepatotoxic Roles of Sex and Sex-Related Hormones

Most liver diseases, including acute liver injury, drug-induced liver injury, viral hepatitis, metabolic liver diseases, and end-stage liver diseases, are strongly linked with hormonal influences. Thus, delineating the clinical manifestation and underlying mechanisms of the “sexual dimorphism” is critical for providing hints for the prevention, management, and treatment of those diseases. Whether the sex hormones (androgen, estrogen, and progesterone) and sex-related hormones (gonadotrophin-releasing hormone, luteinizing hormone, follicle-stimulating hormone, and prolactin) play protective or toxic roles in the liver depends on the biological sex, disease stage, precipitating factor, and even the psychiatric status. Lifestyle factors, such as obesity, alcohol drinking, and smoking, also drastically affect the involving mechanisms of those hormones in liver diseases. Hormones deliver their hepatic regulatory signals primarily via classical and non-classical receptors in different liver cell types. Exogenous sex/sex-related hormone therapy may serve as a novel strategy for metabolic liver disease, cirrhosis, and liver cancer. However, the undesired hormone-induced liver injury should be carefully studied in pre-clinical models and monitored in clinical applications. This issue is particularly important for menopause females with hormone replacement therapy (HRT) and transgender populations who want to receive gender-affirming hormone therapy (GAHT). In conclusion, basic and clinical studies are warranted to depict the detailed hepatoprotective and hepatotoxic mechanisms of sex/sex-related hormones in liver disease. Prolactin holds a promising perspective in treating metabolic and advanced liver diseases.

Sphingosine Kinase 1 Mediates Sexual Dimorphism in Fibrosis in a Mouse Model of NASH

OBJECTIVE

Men with non-alcoholic fatty liver disease (NAFLD) are more likely to progress to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of this dimorphism is unclear. We have previously shown that mice with global deletion of SphK1, the enzyme that produces the bioactive sphingolipid metabolite sphingosine 1-phosphate (S1P), were protected from development of NASH. The aim of this study was to elucidate the role of hepatocyte-specific SphK1 in development of NASH and to compare its contribution to hepatosteatosis in male and female mice.

RESULTS

We generated hepatocyte-specific SphK1 knockout mice (SphK1-hKO). Unlike the global knockout, SphK1-hKO male mice were not protected from diet-induced steatosis, inflammation, or fibrogenesis. In contrast, female SphK1-hKO mice were protected from inflammation. Surprisingly, however, in these female mice, there was a ∼10-fold increase in the fibrosis markers Col1α1 and 2-3 fold induction of alpha smooth muscle actin and the pro-fibrotic chemokine CCL5. Because increased fibrosis in female SphK1-hKO mice occurred despite an attenuated inflammatory response, we investigated the crosstalk between hepatocytes and hepatic stellate cells, central players in fibrosis. We found that estrogen stimulated release of S1P from female hepatocytes preventing TGFβ-induced expression of Col1α1 in HSCs via S1PR3.

CONCLUSIONS

The results revealed a novel pathway of estrogen-mediated cross-talk between hepatocytes and HSCs that may contribute to sex differences in NAFLD through an anti-fibrogenic function of the S1P/S1PR3 axis. This pathway is susceptible to pharmacologic manipulation, which may lead to novel therapeutic strategies.

Chitosan Oligosaccharides Alleviate H2O2-stimulated Granulosa Cell Damage via HIF-1α Signaling Pathway

Oocyte maturation disorder and decreased quality are the main causes of infertility in women, and granulosa cells (GCs) provide the only microenvironment for oocyte maturation through autocrine and paracrine signaling by steroid hormones and growth factors. However, chronic inflammation and oxidative stress caused by ovarian hypoxia are the largest contributors to ovarian aging and GC dysfunction. Therefore, the amelioration of chronic inflammation and oxidative stress is expected to be a pivotal method to improve GC function and oocyte quality. In this study, we detected the protective effect of chitosan oligosaccharides (COS), on hydrogen peroxide- (H₂O₂-) stimulated oxidative damage in a human ovarian granulosa cell line (KGN). COS significantly increased cell viability, mitochondrial function, and the cellular glutathione (GSH) content and reduced apoptosis, reactive oxygen species (ROS) content, and the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial-derived growth factor (VEGF) in H₂O₂-stimulated KGN cells. COS treatment significantly increased levels of the TGF-β1 and IL-10 proteins and decreased levels of the IL-6 protein. Compared with H₂O₂-stimulated KGN cells, COS significantly increased the levels of E₂ and P₄ and decreased SA-β-gal protein expression. Furthermore, COS caused significant inactivation of the HIF-1α-VEGF pathway in H₂O₂-stimulated KGN cells. Moreover, inhibition of this pathway enhanced the inhibitory effects of COS on H₂O₂-stimulated oxidative injury and apoptosis in GCs. Thus, COS protected GCs from H₂O₂-stimulated oxidative damage and apoptosis by inactivating the HIF-1α-VEGF signaling pathway. In the future, COS might represent a therapeutic approach for ameliorating disrupted follicle development.

Nonalcoholic Fatty Liver Disease and Endocrine Axes—A Scoping Review

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease. NAFLD often occurs associated with endocrinopathies. Evidence suggests that endocrine dysfunction may play an important role in NAFLD development, progression, and severity. Our work aimed to explore and summarize the crosstalk between the liver and different endocrine organs, their hormones, and dysfunctions. For instance, our results show that hyperprolactinemia, hypercortisolemia, and polycystic ovary syndrome seem to worsen NAFLD’s pathway. Hypothyroidism and low growth hormone levels also may contribute to NAFLD’s progression, and a bidirectional association between hypercortisolism and hypogonadism and the NAFLD pathway looks likely, given the current evidence. Therefore, we concluded that it appears likely that there is a link between several endocrine disorders and NAFLD other than the typically known type 2 diabetes mellitus and metabolic syndrome (MS). Nevertheless, there is controversial and insufficient evidence in this area of knowledge.

Progesterone Aggravates Lung Fibrosis in a Mouse Model of Systemic Sclerosis

Background

Gender-related factors have explained the higher prevalence of autoimmune diseases in women. Sex hormones play a key role in the immune system and parenchymal cells function; therefore, these hormones can be important in the pathogenesis of autoimmune diseases as a risk or beneficial factor. Lung fibrosis is the main cause of mortality in systemic sclerosis, a female predominant autoimmune disease. The objective of this study was to examine the effect of progesterone on lung fibrosis in a mouse model of systemic sclerosis.

Methods

Mice with bleomycin-induced lung fibrosis treated with progesterone subcutaneously for 21 and 28 days. Blood was collected for hormone and cytokine measurement at the end of treatment then, skin and lung tissues were harvested for histological assessment, gene expression, cytokine, hydroxyproline, and gelatinase measurement.

Results

Trichrome staining and hydroxyproline measurements showed that progesterone treatment increased the content of collagen in fibrotic and normal lung tissues. Progesterone increased α-SMA (P < 0.01), TGF- β (P < 0.05) and decreased MMP9 (P < 0.05) in fibrotic lung tissues. Also progesterone treatment decreased the gene expression of Col1a2 (P <0.05), Ctgf (P <01), End1 (0.001) in bleomycin- injured lung tissues. The serum level of TNF-α was decreased, but the serum level of cortisol was increased by progesterone treatment in fibrotic mice (P< 0.05).

Conclusion

Our results showed that progesterone aggravates lung fibrosis in a mouse model of systemic sclerosis.

The Cost of Reproduction in a Cooperatively Breeding Mammal: Consequences of Seasonal Variation in Rainfall, Reproduction, and Reproductive Suppression

Biological investments, such as reproduction, are influenced by both biotic and abiotic factors and their interactions. The trade-off between reproduction and survival has been well established. Seasonally breeding species, therefore, may exhibit variations in these trade-offs, but there is a dearth of knowledge concerning this. This study investigated the physiological cost of reproduction (measured through oxidative stress) across seasons in the cooperatively breeding highveld mole-rat (Cryptomys hottentotus pretoriae), one of the few seasonal breeding mole-rats. Oxidative stress indicates elevated reactive oxygen species (ROS) levels, which can overwhelm antioxidant defences resulting in damaged proteins, lipids and DNA, which overall can reduce longevity and compromise reproduction. Oxidative markers such as total oxidant status (TOS-measure of total peroxides present), total antioxidant capacity (TAC), oxidative stress index (OSI), and malondialdehyde (MDA) are utilised to measure oxidative stress. In this study, breeding and non-breeding male (NBM) and female mole-rats were captured during the dry season (breeding period) and wet season (non-breeding period). There was an apparent cost of reproduction in the highveld mole-rat; however, the seasonality pattern to the cost of reproduction varied between the sexes. Breeding females (BFs) had significantly higher MDA during the breeding period/dry season in comparison to the non-breeding period/wet season; this is possibly a consequence of bearing and nursing offspring. Contrastingly, breeding males (BMs) showed increased oxidative damage in the non-breeding/wet season compared to the breeding/dry season, possibly due to increased activities of protecting their mating rights for the next breeding/dry season, but this was not significant. Interestingly, during the non-breeding period/wet season, non-breeding females (NBFs) are released from their reproductive suppression, which resulted in increases in TOS and OSI, which again indicated that just the mere ability to be able to breed results in a cost (oxidative stress). Therefore we can speculate that highveld mole-rats exhibited seasonal variation in redox balance brought about by variation in abiotic variables (e.g., rainfall), physiology and behaviour. We conclude that physiological changes associated with reproduction are sufficient to induce significant acute oxidative stress in the plasma of female highveld mole-rats, which become alleviated following transition to the non-breeding season/wet period suggesting a possible hormetic effect.

Estrogens in Hepatocellular Carcinoma: Friends or Foes?

Simple Summary

Today, we know that estrogen hormones are required for the development and function of many organs, such as the liver, in both males and females. However, in some circumstances, estrogen excess may be implicated in the appearance of various chronic diseases, including cancer. This review will inspect the results of several studies to better understand the mechanisms responsible for estrogens to change from protective into harmful hormones in human liver.

Abstract

Estrogens are recognized as key players in physiological regulation of various, classical and non-classical, target organs, and tissues, including liver development, homeostasis, and function. On the other hand, multiple, though dispersed, experimental evidence is highly suggestive for the implication of estrogen in development and progression of hepatocellular carcinoma. In this paper, data from our own studies and the current literature are reviewed to help understanding this apparent discrepancy.

Acute aggressive behavior perturbates the oxidative status of a wild bird independently of testosterone and progesterone

Aerobically demanding activities like aggression can lead to an elevated oxidative metabolism affecting the concentration of pro-oxidant and antioxidant compounds and can result in an overall perturbation of the oxidative status. Aggression may also alter the oxidative status indirectly through an increase in testosterone and progesterone concentrations. Given that changes in the oxidative status could represent a physiological cost of aggression, we tested the hypothesis that acute conspecific aggression impairs the oxidative status and evaluated the role of testosterone and progesterone as potential mediators. To achieve this, we experimentally manipulated the aggressive behavior of wild female and male birds and measured the concentrations of pro-oxidants, enzymatic- and non-enzymatic antioxidants, testosterone and progesterone in blood. After 20 min of conspecific aggressive behavior, both sexes had lower concentrations of non-enzymatic antioxidants than control individuals. This effect was independent of testosterone and progesterone concentrations, and much stronger in females than in males. Further, only in females (but not in males) being more aggressive came at the expense of lower antioxidant concentration. We provide the first experimental evidence that acute aggressive behavior perturbates the oxidative state of a wild vertebrate independently of testosterone and progesterone, with potential ecological and evolutionary implications given the role of the redox system in shaping life-history traits.

Hepatoprotective effect and possible mechanism of phytoestrogen calycosin on carbon tetrachloride-induced liver fibrosis in mice

The study was to explore the hepatoprotective effect and possible mechanism of calycosin on carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Hepatic fibrosis was induced by intraperitoneal injection of CCl4 in C57BL/6 male mice. Serum alanine aminotransferase (ALT) and aspartate transaminase (AST) activity, superoxide dismutase (SOD) activity, and hydroxyproline (Hyp) and malondialdehyde (MDA) levels were determined by biochemical assays. Liver histopathology was assessed by H&E and Masson trichrome staining. The mRNA expressions of α-smooth muscle actin (α-SMA), collagen-I (Col-I), Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were determined using qRT-PCR. The protein levels of α-SMA, Col-I, estrogen receptor α (ERα), estrogen receptor β (ERβ), tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase-1 (MMP-1), JAK2, phospho-JAK2 (p-JAK2), STAT3, and phospho-STAT3 (p-STAT3) were detected by Western blotting. The levels of α-SMA and ERβ were measured by immunohistochemistry. Calycosin significantly reduced liver index, MDA level, and ALT and AST activity and increased SOD activity. The α-SMA, Col-I, and Hyp of the calycosin group were significantly lower than those of the model group. Calycosin increased MMP-1 and inhibited TIMP-1 expression resulting in the improvement of MMP-1/TIMP-1 ratio. Importantly, calycosin improved ERβ protein expression, JAK2 and STAT3 mRNA expressions, p-JAK2/JAK2, and p-STAT3/STAT3 relative protein expressions. However, ERα, JAK2, and STAT3 protein expressions were relatively unchanged. Calycosin significantly inhibits liver fibrosis in mice, and its mechanism may involve the following: calycosin inhibits oxidative stress; calycosin inhibits collagen synthesis and balances MMP-1/TIMP-1 system; calycosin increases ERβ expression and activates JAK2-STAT3 pathway.

Influence of Gender and Reproductive Factors on Liver Fibrosis in Patients With Chronic Hepatitis B Infection

INTRODUCTION:

The role of reproductive factors in the development of chronic hepatitis B (CHB) remains unknown. We assessed the potential contributions of gender, menopausal status, and menarche age to liver fibrosis in CHB.

METHODS:

A cross-sectional prospective study included 716 women and 716 age-matched men with CHB who were not currently receiving antiviral therapy. Liver stiffness measurement using transient elastography was used to stage liver fibrosis as F0–F1 (<7.2 kPa), F ≥ 2 (7.2 kPa), F ≥ 3 (9.4 kPa), and F = 4 (12.2 kPa). Female patients were asked regarding their age at menarche and menopausal status using a questionnaire.

RESULTS:

Of the 716 women, 121 (16.9%) were postmenopausal, and 80 (11.2%) had advanced liver fibrosis. Multivariate logistic regression analysis showed that the postmenopausal status compared with the premenopausal status (odds ratio [OR] = 3.65–8.83; P < 0.05) and age at menarche of >14 years compared with <13 years (OR = 2.85–3.95; P < 0.05) were significantly associated with advanced fibrosis. Compared with premenopausal women, age-matched men had a higher OR for advanced fibrosis (P < 0.05). Compared with postmenopausal women, age-matched men did not show a significant difference in the degree of liver fibrosis (P > 0.05). Longitudinal data analysis showed that postmenopausal women (n = 31) were significantly less likely to undergo regression of liver fibrosis after antiviral treatment vs premenopausal women (n = 19) (26.3% vs 74.2%, respectively; P < 0.001).

DISCUSSION:

Menopause and late menarche aggravated liver fibrosis in untreated CHB, besides menopause delayed fibrosis regression under antiviral therapy. The protective effect of female gender against fibrosis was lost for postmenopausal women.

TRANSLATIONAL IMPACT:

It is important to consider menopausal status and age at menarche in establishing surveillance strategies among CHB females. Postmenopausal estrogen therapy may be considered for the prevention or treatment of liver fibrosis.

Characteristic Features of Nonalcoholic Fatty Liver Disease in Japan with a Focus on the Roles of Age, Sex and Body Mass Index

This review provides an update on the characteristics of nonalcoholic fatty liver disease (NAFLD), with a focus on the effects of age, sex, and body mass index. Age is a risk factor for NAFLD progression; however, extremely old patients have unique features, namely, the associations between metabolic comorbidities and NAFLD are weaker and NAFLD is not a risk factor for mortality. The prevalence of NAFLD is higher in men than in premenopausal women, whereas the reverse is true after menopause. Thus, before menopause, estrogen may have protective effects against NAFLD. Our hospital data showed that over 25% of male patients with NAFLD and almost 40% of female patients with NAFLD, especially elderly patients, were nonobese. Although histological steatosis and activity were associated with body mass index, the prevalence of nonalcoholic steatohepatitis was not. The prevalence of advanced fibrosis showed a significant sex difference. Advanced fibrosis was significantly more frequent among severely obese men but the prevalence was lower among severely obese women. This difference could be because a substantial proportion of severely obese women were premenopausal; thus, estrogen may have much stronger effects on the development of fibrosis than on obesity. Further studies are required to develop tailored management strategies.

The Role of Airways 17β-Estradiol as a Biomarker of Severity in Postmenopausal Asthma: A Pilot Study

Background: Asthma severity differs according to gender; in adult women, there is higher prevalence and severity of asthma than in men, and it coincides with changes in sex hormones. Recently, a new phonotype of asthma has been identified that appears after menopause, and it may be associated with decreased estrogen levels. Our goal was to study the 17β-estradiol (E2) concentrations in the blood and airways of women affected by asthma onset after menopause, evaluating its possible role in the severity of the disease. Methods: We enrolled 33 consecutive women with a diagnosis of postmenopausal asthma, recruited from the outpatient pulmonary clinic: 18 with severe (SA) and 15 with mild-to-moderate (MMA) asthma. We also included 30 age-matched healthy menopausal women as controls (HS). All subjects enrolled underwent blood and sputum collection (IS), and E2 concentrations were determined in plasma and sputum supernatant samples using an enzyme-linked immunosorbent assay (ELISA) kit. Results: Significantly higher serum concentrations of E2 were found in postmenopausal SA compared to MMA and HS, respectively (33 ± 5.5 vs. 24 ± 6.63 vs. 7.79 ± 1.54 pg/mL, p < 0.05). Similar results were found in the IS: significantly higher levels of E2 were detected in patients with postmenopausal SA compared with MMA and HS, respectively (0.34 ± 0.17 vs. 0.26 ± 0.13 vs. 0.07 ± 0.06 pg/mL, p < 0.05). We found positive correlations between IS E2 concentrations and sputum neutrophil levels in SA group (ρ = 0.52, p < 0.05). Conclusions: Our findings showed the possibility to measure E2 in the airways, and it has increased in postmenopausal asthmatic patients, especially in those with SA. Airways E2 levels may serve as a suitable biomarker of postmenopausal SA to help to phenotype SA patients with neutrophil inflammation.

NAFLD in women: Unique pathways, biomarkers and therapeutic opportunities

Purpose of review

In this review article we evaluate sex differences in the natural history of NAFLD and highlight distinct risk profiles of women with NAFLD, as well as unique treatment considerations and research gaps.

Summary of findings

Reproductive factors, such as menopausal status should be considered when evaluating NAFLD risk in women, as well as additional reproductive risk factors such as age at menarche, presence of polycystic ovary syndrome, and gestational diabetes. Women do appear to have lower risk for hepatocellular carcinoma from NASH, as well as lower mortality from NASH cirrhosis than men, although among women, NASH is now the leading indication for liver transplant. Data on sex differences in biomarker development and clinical trials are lacking, and researchers should be encouraged to evaluate biomarker performance by sex, and specifically report clinical trial endpoints in women.

Menopause and Non-Alcoholic Fatty Liver Disease: A Review Focusing on Therapeutic Perspectives

There is increasing evidence that menopause is associated with the progression and severity of non-alcoholic fatty liver disease (NAFLD). Estrogen deficiency worsens non-alcoholic steatohepatitis (NASH) in mice models with fatty liver. The prevalence of NAFLD seems to be higher in postmenopausal compared with premenopausal women. Although more data are needed, lower serum estradiol levels are associated with NASH in postmenopausal women. Apart from estrogen deficiency, relative androgen excess and decrease in sex hormone-binding protein are observed in postmenopausal women. These hormonal changes seem to interplay with an increase in abdominal adipose mass, also observed in postmenopausal women, and aging, which are both closely related to the severity and progressive forms of NAFLD. NAFLD adds extra morbidity to postmenopausal women, possibly increasing the risk of type 2 diabetes mellitus and cardiovascular disease. Improving parameters of the metabolic syndrome via modifications in diet and physical exercise may reduce the risk of NAFLD and its related morbidity. Limited studies have shown a beneficial effect of hormone replacement therapy (HRT) on NAFLD, although adverse hepatic effects have been attributed to progesterone in one study. Phytoestrogens may be alternatives to HRT, but their long-term efficacy and safety remain to be shown. The aim of this review was to summarize evidence linking menopause with NAFLD with a special focus on potential therapeutic perspectives.

Potential Therapeutic Application of Estrogen in Gender Disparity of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) caused by fat accumulation in the liver is globally the most common cause of chronic liver disease. Simple steatosis can progress to nonalcoholic steatohepatitis (NASH), a more severe form of NAFLD. The most potent driver for NASH is hepatocyte death induced by lipotoxicity, which triggers inflammation and fibrosis, leading to cirrhosis and/or liver cancer. Despite the significant burden of NAFLD, there is no therapy for NAFLD/NASH. Accumulating evidence indicates gender-related NAFLD progression. A higher incidence of NAFLD is found in men and postmenopausal women than premenopausal women, and the experimental results, showing protective actions of estradiol in liver diseases, suggest that estrogen, as the main female hormone, is associated with the progression of NAFLD/NASH. However, the mechanism explaining the functions of estrogen in NAFLD remains unclear because of the lack of reliable animal models for NASH, the imbalance between the sexes in animal experiments, and subsequent insufficient results. Herein, we reviewed the pathogenesis of NAFLD/NASH focused on gender and proposed a feasible association of estradiol with NAFLD/NASH based on the findings reported thus far. This review would help to expand our knowledge of the gender differences in NAFLD and for developing gender-based treatment strategies for NAFLD/NASH.

Sex Differences in Nonalcoholic Fatty Liver Disease: State of the Art and Identification of Research Gaps

Despite tremendous research advancements in nonalcoholic fatty liver disease (NAFLD), our understanding of sex differences in NAFLD remains insufficient. This review summarizes the current knowledge on sex differences in NAFLD, identifies gaps, and discusses important considerations for future research. The prevalence and severity of NAFLD are higher in men than in women during the reproductive age. However, after menopause, NAFLD occurs at a higher rate in women, suggesting that estrogen is protective. Sex differences also exist for the major risk factors of NAFLD. In general, animal models of NAFLD recapitulate the sex differences observed in patients, with more severe steatosis and steatohepatitis, more proinflammatory/profibrotic cytokines, and a higher incidence of hepatic tumors in male than female subjects. Based on computer modeling, female and male livers are metabolically distinct with unique regulators modulating sex-specific metabolic outcomes. Analysis of the literature reveals that most published clinical and epidemiological studies fail to examine sex differences appropriately. Considering the paucity of data on sex differences and the knowledge that regulators of pathways relevant to current therapeutic targets for NAFLD differ by sex, clinical trials should be designed to test drug efficacy and safety according to sex, age, reproductive stage (i.e., menopause), and synthetic hormone use. Conclusion: Sex differences do exist in the prevalence, risk factors, fibrosis, and clinical outcomes of NAFLD, suggesting that, while not yet incorporated, sex will probably be considered in future practice guidelines; adequate consideration of sex differences, sex hormones/menopausal status, age, and other reproductive information in clinical investigation and gene association studies of NAFLD are needed to fill current gaps and implement precision medicine for patients with NAFLD.

Beneficial and Deleterious Effects of Female Sex Hormones, Oral Contraceptives, and Phytoestrogens by Immunomodulation on the Liver

The liver is considered the laboratory of the human body because of its many metabolic processes. It accomplishes diverse activities as a mixed gland and is in continuous cross-talk with the endocrine system. Not only do hormones from the gastrointestinal tract that participate in digestion regulate the liver functions, but the sex hormones also exert a strong influence on this sexually dimorphic organ, via their receptors expressed in liver, in both health and disease. Besides, the liver modifies the actions of sex hormones through their metabolism and transport proteins. Given the anatomical position and physiological importance of liver, this organ is evidenced as an immune vigilante that mediates the systemic immune response, and, in turn, the immune system regulates the hepatic functions. Such feedback is performed by cytokines. Pro-inflammatory and anti-inflammatory cytokines are strongly involved in hepatic homeostasis and in pathological states; indeed, female sex hormones, oral contraceptives, and phytoestrogens have immunomodulatory effects in the liver and the whole organism. To analyze the complex and interesting beneficial or deleterious effects of these drugs by their immunomodulatory actions in the liver can provide the basis for either their pharmacological use in therapeutic treatments or to avoid their intake in some diseases.

Protective effect of genistein on nonalcoholic fatty liver disease (NAFLD)

NAFLD is a vital health problem worldwide; however, no effective treatment is currently available for NAFLD. Intensive studies have indicated the efficacy of genistein (GE), a bioactive isoflavone extracted from soy, in treating NAFLD. In addition to its oestrogen-like effects, GE is known to have multiple molecular effects, for instance, lipid and glucose metabolism-promoting effects and activities against lipid peroxidation, inflammation, fibrosis, and NAFLD-related tumours. Here, this review summarizes the potential role of GE in the treatment and prevention of NAFLD and some of the currently known targets and signalling pathways of GE in NAFLD.

Reproductive Endocrinology of Nonalcoholic Fatty Liver Disease

The liver and the reproductive system interact in a multifaceted bidirectional fashion. Sex steroid signaling influences hepatic endobiotic and xenobiotic metabolism and contributes to the pathogenesis of functional and structural disorders of the liver. In turn, liver function affects the reproductive axis via modulating sex steroid metabolism and transport to tissues via sex hormone-binding globulin (SHBG). The liver senses the body's metabolic status and adapts its energy homeostasis in a sex-dependent fashion, a dimorphism signaled by the sex steroid milieu and possibly related to the metabolic costs of reproduction. Sex steroids impact the pathogenesis of nonalcoholic fatty liver disease, including development of hepatic steatosis, fibrosis, and carcinogenesis. Preclinical studies in male rodents demonstrate that androgens protect against hepatic steatosis and insulin resistance both via androgen receptor signaling and, following aromatization to estradiol, estrogen receptor signaling, through regulating genes involved in hepatic lipogenesis and glucose metabolism. In female rodents in contrast to males, androgens promote hepatic steatosis and dysglycemia, whereas estradiol is similarly protective against liver disease. In men, hepatic steatosis is associated with modest reductions in circulating testosterone, in part consequent to a reduction in circulating SHBG. Testosterone treatment has not been demonstrated to improve hepatic steatosis in randomized controlled clinical trials. Consistent with sex-dimorphic preclinical findings, androgens promote hepatic steatosis and dysglycemia in women, whereas endogenous estradiol appears protective in both men and women. In both sexes, androgens promote hepatic fibrosis and the development of hepatocellular carcinoma, whereas estradiol is protective.

Inhibition effect of phytoestrogen calycosin on TGF-β1-induced hepatic stellate cell activation, proliferation, and migration via estrogen receptor β

The present study was designed to investigate the effects of calycosin on hepatic stellate cell (HSC) function and to explore whether the drug exerts its effect through the estrogen receptor. HSC proliferation and migration were measured by MTT assay and transwell chamber assay, respectively. The mRNA and protein expression of α-SMA, COL-I, and ERβ were detected by real-time PCR and Western blotting. The co-localization and expression of α-SMA and ERβ protein were detected by immunofluorescence. All the studies were investigated in the absence or presence of ICI 182,780. The results showed that calycosin inhibited the proliferation of activated HSCs and remarkably inhibited HSC migration. Calycosin significantly reduced the expression of α-SMA and COL-I in activated HSCs. However, with co-treatment with ICI 182,780, the inhibitory effect of calycosin against the above effects was strongly negated. Importantly, calycosin significantly downregulated the expression of ERβ protein, while co-treatment with ICI 182,780 partially reversed the ERβ downregulation. In addition, α-SMA decreased with the decrease of ERβ expression and the subtype of ERβ on HSC is ERβ5. In conclusion, calycosin inhibits proliferation, activation, and migration of TGF-β1-induced HSCs. The effect may be related to binding and downregulation of ERβ5.

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and liver fibrosis: A review

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are key producer of reactive oxygen species in liver cells. Hepatic stellate cells (HSCs) and Kupffer cells (KCs) are the two key cells for expression of NOX in liver. KCs produce only NOX2, while HSCs produce NOX1, 2, and 4, all of which play essential roles in the process of fibrogenesis within liver. These NOX subtypes are contributed to induction of liver fibrosis by acting through multiple pathways including induction of HSC activation, proliferation, survival and migration, stimulation of hepatocyte apoptosis, enhancement of fibrogenic mediators, and mediation of an inflammatory cascade in both KCs and HSCs.

SIGNIFICANCE

KCs and HSCs are two key cells for production of NOX in liver in relation to the pathology of liver fibrosis. NOX subtypes 1, 2, and 4 are inducers of fibrogenesis in liver. NOX activation favors hepatocyte apoptosis, HSC activation, and KC-mediated inflammatory cascade in liver, all of which are responsible for generation of liver fibrosis.

Expression patterns of STAT3, ERK and estrogen-receptor α are associated with development and histologic severity of hepatic steatosis: a retrospective study

BACKGROUND

Hepatic steatosis renders hepatocytes vulnerable to injury, resulting in the progression of preexisting liver disease. Previous animal and cell culture studies implicated mammalian target of rapamycin (mTOR), signal transducer and activator of transcription-3 (STAT3), extracellular signal-regulated kinase (ERK) and estrogen-receptor α in the pathogenesis of hepatic steatosis and disease progression. However, to date there have been few studies performed using human liver tissue to study hepatic steatosis. We examined the expression patterns of mTOR, STAT3, ERK and estrogen-receptor α in liver tissues from patients diagnosed with hepatic steatosis.

METHODS

We reviewed the clinical and histomorphological features of 29 patients diagnosed with hepatic steatosis: 18 with non-alcoholic fatty liver disease (NAFLD), 11 with alcoholic fatty acid disease (AFLD), and a control group (16 biliary cysts and 22 hepatolithiasis). Immunohistochemistry was performed on liver tissue using an automated immunostainer. The histologic severity of hepatic steatosis was evaluated by assessing four key histomorphologic parameters common to NAFLD and AFLD: steatosis, lobular inflammation, ballooning degeneration and fibrosis.

RESULTS

mTOR, phosphorylated STAT3, phosphorylated pERK, estrogen-receptor α were found to be more frequently expressed in the hepatic steatosis group than in the control group. Specifically, mTOR was expressed in 78% of hepatocytes, and ERK in 100% of hepatic stellate cells, respectively, in patients with NAFLD. Interestingly, estrogen-receptor α was diffusely expressed in hepatocytes in all NALFD cases. Phosphorylated (active) STAT3 was expressed in 73% of hepatocytes and 45% of hepatic stellate cells in patients with AFLD, and phosphorylated (active) ERK was expressed in hepatic stellate cells in all AFLD cases. Estrogen-receptor α was expressed in all AFLD cases (focally in 64% of AFLD cases, and diffusely in 36%). Phosphorylated STAT3 expression in hepatocytes and hepatic stellate cells correlated with severe lobular inflammation, severe ballooning degeneration and advanced fibrosis, whereas diffusely expressed estrogen-receptor α correlated with a mild stage of fibrosis.

CONCLUSIONS

Our data indicate ERK activation and estrogen-receptor α may be relevant in the development of hepatic steatosis. However, diffuse expression of estrogen-receptor α would appear to impede disease progression, including hepatic fibrosis. Finally, phosphorylated STAT3 may also contribute to disease progression.

Estrogen receptor‑β‑dependent effects of saikosaponin‑d on the suppression of oxidative stress‑induced rat hepatic stellate cell activation

Saikosaponin-d (SSd) is one of the major triterpenoid saponins derived from Bupleurum falcatum L., which has been reported to possess antifibrotic activity. At present, there is little information regarding the potential target of SSd in hepatic stellate cells (HSCs), which serve an important role in excessive extracellular matrix (ECM) deposition during the pathogenesis of hepatic fibrosis. Our recent study indicated that SSd may be considered a novel type of phytoestrogen with estrogen-like actions. Therefore, the present study aimed to investigate the effects of SSd on the proliferation and activation of HSCs, and the underlying mechanisms associated with estrogen receptors. In the present study, a rat HSC line (HSC-T6) was used and cultured with dimethyl sulfoxide, SSd, or estradiol (E₂; positive control), in the presence or absence of three estrogen receptor (ER) antagonists [ICI-182780, methylpiperidinopyrazole (MPP) or (R,R)-tetrahydrochrysene (THC)], for 24 h as pretreatment. Oxidative stress was induced by exposure to hydrogen peroxide for 4 h. Cell proliferation was assessed by MTT growth assay. Malondialdehyde (MDA), CuZn-superoxide dismutase (CuZn-SOD), tissue inhibitor of metalloproteinases-1 (TIMP- 1), matrix metalloproteinase-1 (MMP-1), transforming growth factor-β1 (TGF-β1), hydroxyproline (Hyp) and collagen-1 (COL1) levels in cell culture supernatants were determined by ELISA. Reactive oxygen species (ROS) was detected by flow cytometry. Total and phosphorylated mitogen-activated protein kinases (MAPKs) and α-smooth muscle actin (α-SMA) were examined by western blot analysis. TGF-β1 mRNA expression was determined by RT-quantitative (q)PCR. SSd and E₂ were able to significantly suppress oxidative stress-induced proliferation and activation of HSC-T6 cells. Furthermore, SSd and E₂ were able to reduce ECM deposition, as demonstrated by the decrease in transforming growth factor-β1, hydroxyproline, collagen-1 and tissue inhibitor of metalloproteinases-1, and by the increase in matrix metalloproteinase-1. These results suggested that the possible molecular mechanism could involve downregulation of the reactive oxygen species/mitogen-activated protein kinases signaling pathway. Finally, the effects of SSd and E₂ could be blocked by co-incubation with ICI-182780 or THC, but not MPP, thus indicating that ERβ may be the potential target of SSd in HSC-T6 cells. In conclusion, these findings suggested that SSd may suppress oxidative stress-induced activation of HSCs, which relied on modulation of ERβ.

Associations of gender and a proxy of female menopausal status with histological features of drug-induced liver injury

BACKGROUND & AIM

Gender and menopause may contribute to type and severity of drug-induced liver injury (DILI) by influencing host responses to injury. The aim of this study was to assess the associations of gender and female age 50 [a proxy of menopause] with histological features of liver injury in 212 adults enrolled in the Drug-Induced Liver Injury Network (DILIN) registry.

METHODS

All participants had a causality score of at least 'probable', a liver biopsy within 30 days of DILI onset, and no prior chronic liver disease. Biochemical and histological injury types were classified as hepatocellular or cholestatic/mixed injury. The cohort was divided into three gender/age categories: men (41.0%), women <50 years (27.4%) and women ≥50 years of age (31.6%). Interaction of gender and age category (≥50 or not) was assessed.

RESULTS

Hepatocellular injury was more prevalent in women <50 years vs. others (P=.002). After adjusting for biochemical injury types, black race and possible ageing effects, more severe interface hepatitis was noted in biopsies of women <50 years compared to those of men and women ≥50 years (P=.009 and P=.055 respectively). Compared to those of men, biopsies of women showed greater plasma cell infiltration, hepatocyte apoptosis, hepatocyte rosettes and lobular disarray but less iron-positive hepatocytes and histological cholestasis (P<.05). These associations persisted after excluding cases of amoxicillin/clavulanic acid, anabolic steroids or nitrofurantoin DILI which showed gender-specific distributions.

CONCLUSION

Gender and a proxy of menopause were associated with various features of inflammation and injury in DILI.

Child mortality, hypothalamic-pituitary-adrenal axis activity and cellular aging in mothers

Psychological challenges, including traumatic events, have been hypothesized to increase the age-related pace of biological aging. Here we test the hypothesis that psychological challenges can affect the pace of telomere attrition, a marker of cellular aging, using data from an ongoing longitudinal-cohort study of Kaqchikel Mayan women living in a population with a high frequency of child mortality, a traumatic life event. Specifically, we evaluate the associations between child mortality, maternal telomere length and the mothers’ hypothalamic-pituitary-adrenal axis (HPAA), or stress axis, activity. Child mortality data were collected in 2000 and 2013. HPAA activity was assessed by quantifying cortisol levels in first morning urinary specimens collected every other day for seven weeks in 2013. Telomere length (TL) was quantified using qPCR in 55 women from buccal specimens collected in 2013. Results: Shorter TL with increasing age was only observed in women who experienced child mortality (p = 0.015). Women with higher average basal cortisol (p = 0.007) and greater within-individual variation (standard deviation) in basal cortisol (p = 0.053) presented shorter TL. Non-parametric bootstrapping to estimate mediation effects suggests that HPAA activity mediates the effect of child mortality on TL. Our results are, thus, consistent with the hypothesis that traumatic events can influence cellular aging and that HPAA activity may play a mediatory role. Future large-scale longitudinal studies are necessary to confirm our results and further explore the role of the HPAA in cellular aging, as well as to advance our understanding of the underlying mechanisms involved.

17,β-estradiol inhibits hepatitis C virus mainly by interference with the release phase of its life cycle

BACKGROUND & AIMS

Oestrogen and oestrogen-mediated signalling protect from hepatitis C virus through incompletely understood mechanisms. We aimed to ascertain which phase(s) of hepatitis C virus life cycle is/are affected by oestrogens.

METHODS

Huh7 cells infected with the JFH1 virus (genotype 2a) were exposed to dehydroepiandrosterone, testosterone, progesterone and 17β-estradiol (tested with/without its receptor antagonist fulvestrant). Dose-response curves were established to calculate half maximal inhibitory concentration values. To dissect how 17β-estradiol interferes with phases of hepatitis C virus life cycle, its effects were measured on the hepatitis C virus pseudo-particle system (viral entry), the subgenomic replicon N17/JFH1 and the replicon cell line Huh7-J17 (viral replication). Finally, in a dual-step infection model, infectious supernatants, collected from infected cells exposed to hormones, were used to infect naïve cells.

RESULTS

Progesterone and testosterone showed no inhibitory effect on hepatitis C virus; dehydroepiandrosterone was only mildly inhibitory. In contrast, 17β-estradiol inhibited infection by 64%-67% (IC₅₀ values 140-160 nmol/L). Fulvestrant reverted the inhibition by 17β-estradiol in a dose-dependent manner. 17β-estradiol exerted only a slight inhibition (<20%) on hepatitis C virus pseudo-particles, and had no effect on cells either transiently or stably (Huh7-J17 cells) expressing the N17/JFH1 replicon. In the dual-step infection model, a significant half maximal inhibitory concentration decline occurred between primary (134 nmol/L) and secondary (100 nmol/L) infections (P=.02), with extracellular hepatitis C virus RNA and infectivity being reduced to a higher degree in comparison to its intracellular counterpart.

CONCLUSIONS

17β-estradiol inhibits hepatitis C virus acting through its intracellular receptors, mainly interfering with late phases (assembly/release) of the hepatitis C virus life cycle.

The stellate cell system (vitamin A-storing cell system)

Past, present, and future research into hepatic stellate cells (HSCs, also called vitamin A-storing cells, lipocytes, interstitial cells, fat-storing cells, or Ito cells) are summarized and discussed in this review. Kupffer discovered black-stained cells in the liver using the gold chloride method and named them stellate cells (Sternzellen in German) in 1876. Wake rediscovered the cells in 1971 using the same gold chloride method and various modern histological techniques including electron microscopy. Between their discovery and rediscovery, HSCs disappeared from the research history. Their identification, the establishment of cell isolation and culture methods, and the development of cellular and molecular biological techniques promoted HSC research after their rediscovery. In mammals, HSCs exist in the space between liver parenchymal cells (PCs) or hepatocytes and liver sinusoidal endothelial cells (LSECs) of the hepatic lobule, and store 50-80% of all vitamin A in the body as retinyl ester in lipid droplets in the cytoplasm. SCs also exist in extrahepatic organs such as pancreas, lung, and kidney. Hepatic (HSCs) and extrahepatic stellate cells (EHSCs) form the stellate cell (SC) system or SC family; the main storage site of vitamin A in the body is HSCs in the liver. In pathological conditions such as liver fibrosis, HSCs lose vitamin A, and synthesize a large amount of extracellular matrix (ECM) components including collagen, proteoglycan, glycosaminoglycan, and adhesive glycoproteins. The morphology of these cells also changes from the star-shaped HSCs to that of fibroblasts or myofibroblasts.

TCF7L2 involvement in estradiol- and progesterone-modulated islet and hepatic glucose homeostasis

To evaluate the role of TCF7L2, a key regulator of glucose homeostasis, in estradiol (E2) and progesterone (P4)-modulated glucose metabolism, mouse insulinoma cells (MIN6) and human liver cancer cells (hepG2 and HUH7) were treated with physiological concentrations of E2 or P4 in the up- and down-regulation of TCF7L2. Insulin/proinsulin secretion was measured in MIN6 cells, while glucose uptake and production were evaluated in liver cancer cells. E2 increased insulin/proinsulin secretion under both basal and stimulated conditions, whereas P4 increased insulin/proinsulin secretion only under glucose-stimulated conditions. An antagonistic effect, possibly concentration-dependent, of E2 and P4 on the regulation of islet glucose metabolism was observed. After E2 or P4 treatment, secretion of insulin/proinsulin was positively correlated with TCF7L2 protein expression. When TCF7L2 was silenced, E2- or P4-promoted insulin/proinsulin secretion was significantly weakened. Under glucotoxicity conditions, overexpression of TCF7L2 increased insulin secretion and processing. In liver cancer cells, E2 or P4 exposure elevated TCF7L2 expression, enhanced the activity of insulin signaling (pAKT/pGSK), reduced PEPCK expression, subsequently increased insulin-stimulated glucose uptake, and decreased glucose production. Silencing TCF7L2 eliminated effects of E2 or P4. In conclusion, TCF7L2 regulates E2- or P4-modulated islet and hepatic glucose metabolism. The results have implications for glucose homeostasis in pregnancy.

A "systems medicine" approach to the study of non-alcoholic fatty liver disease

The prevalence of fatty liver (steatosis) in the general population is rapidly increasing worldwide. The progress of knowledge in the physiopathology of fatty liver is based on the systems biology approach to studying the complex interactions among different physiological systems. Similarly, translational and clinical research should address the complex interplay between these systems impacting on fatty liver. The clinical needs drive the applications of systems medicine to re-define clinical phenotypes, assessing the multiple nature of disease susceptibility and progression (e.g. the definition of risk, prognosis, diagnosis criteria, and new endpoints of clinical trials). Based on this premise and in light of recent findings, the complex mechanisms involved in the pathology of fatty liver and their impact on the short- and long-term clinical outcomes of cardiovascular, metabolic liver diseases associated with steatosis are presented in this review using a new "systems medicine" approach. A new data set is proposed for studying the impairments of different physiological systems that have an impact on fatty liver in different subsets of subjects and patients.

Number of Children and Telomere Length in Women: A Prospective, Longitudinal Evaluation

Life history theory (LHT) predicts a trade-off between reproductive effort and the pace of biological aging. Energy invested in reproduction is not available for tissue maintenance, thus having more offspring is expected to lead to accelerated senescence. Studies conducted in a variety of non-human species are consistent with this LHT prediction. Here we investigate the relationship between the number of surviving children born to a woman and telomere length (TL, a marker of cellular aging) over 13 years in a group of 75 Kaqchikel Mayan women. Contrary to LHT's prediction, women who had fewer children exhibited shorter TLs than those who had more children (p = 0.045) after controlling for TL at the onset of the 13-year study period. An "ultimate" explanation for this apparently protective effect of having more children may lay with human's cooperative-breeding strategy. In a number of socio-economic and cultural contexts, having more chilren appears to be linked to an increase in social support for mothers (e.g., allomaternal care). Higher social support, has been argued to reduce the costs of further reproduction. Lower reproductive costs may make more metabolic energy available for tissue maintenance, resulting in a slower pace of cellular aging. At a "proximate" level, mechanisms involved may include the actions of the gonadal steroid estradiol, which increases dramatically during pregnancy. Estradiol is known to protect TL from the effects of oxidative stress as well as increase telomerase activity, an enzyme that maintains TL. Future research should explore the potential role of social support as well as that of estradiol and other potential biological pathways in the trade-offs between reproductive effort and the pace of cellular aging within and among human as well as in non-human populations.

Raloxifene Ameliorates Liver Fibrosis of Nonalcoholic Steatohepatitis Induced by Choline-Deficient High-Fat Diet in Ovariectomized Mice

BACKGROUND AND AIM

The prevalence of nonalcoholic fatty liver disease (NAFLD) is higher in men than in women, but according to some epidemiological studies, this gender difference disappears after menopause. Estrogen therapy protects against NAFLD and nonalcoholic steatohepatitis (NASH) after menopause. We investigated the therapeutic effect of raloxifene, a second-generation selective estrogen-receptor modulator, on NASH induced by a choline-deficient high-fat (CDHF) diet in female ovariectomized (OVX) mice.

METHODS

Seven-week-old female C57BL/6J mice were divided into three experimental groups as follows: (1) sham operation (SHAM group), (2) ovariectomy (OVX group), and (3) ovariectomy + raloxifene (intraperitoneal injection, 3 mg/kg body weight/day; OVX + RLX group). These three groups of mice were fed a CDHF diet for 8 weeks; choline-sufficient high-fat (CSHF) diet was used as control diet. Serum biochemical indicators of hepatic function and liver histological changes were evaluated.

RESULTS

Compared with CSHF diet, ovariectomy enhances liver injury and fibrosis in CDHF diet-fed mice. Serum alanine aminotransferase (ALT) levels were significantly lower in the OVX + RLX group than in the OVX group. The OVX group developed extensive steatosis with inflammation and fibrosis. Lobular inflammatory scores and fibrosis staging in the OVX + RLX group were significantly lower than in the OVX group. Furthermore, the OVX + RLX group exhibited significantly higher expression of hepatic estrogen receptor-α, which was significantly lower in the OVX group than in the SHAM group.

CONCLUSIONS

Raloxifene may ameliorate progression of liver fibrosis of NASH induced by CDHF diet in ovariectomized female mice, and up-regulation of estrogen receptor-α may play an important role in the beneficial effects of raloxifene on NASH.

Ovarian senescence increases liver fibrosis in humans and zebrafish with steatosis

Contrasting data exist on the effect of gender and menopause on the susceptibility, development and liver damage progression in non-alcoholic fatty liver disease (NAFLD). Our aim was to assess whether menopause is associated with the severity of liver fibrosis in individuals with NAFLD and to explore the issue of ovarian senescence in experimental liver steatosis in zebrafish. In 244 females and age-matched males with biopsy-proven NAFLD, we assessed anthropometric, biochemical and metabolic features, including menopausal status (self-reported); liver biopsy was scored according to 'The Pathology Committee of the NASH Clinical Research Network'. Young and old male and female zebrafish were fed for 24 weeks with a high-calorie diet. Weekly body mass index (BMI), histopathological examination and quantitative real-time PCR analysis on genes involved in lipid metabolism, inflammation and fibrosis were performed. In the entire cohort, at multivariate logistic regression, male gender [odds ratio (OR): 1.408, 95% confidence interval (95% CI): 0.779-2.542, P=0.25] vs women at reproductive age was not associated with F2-F4 fibrosis, whereas a trend was observed for menopause (OR: 1.752, 95% CI: 0.956-3.208, P=0.06). In women, menopause (OR: 2.717, 95% CI: 1.020-7.237, P=0.04) was independently associated with F2-F4 fibrosis. Similarly, in overfed zebrafish, old female fish with failing ovarian function [as demonstrated by extremely low circulating estradiol levels (1.4±0.1 pg/µl) and prevailing presence of atretic follicles in the ovaries] developed massive steatosis and substantial fibrosis (comparable with that occurring in males), whereas young female fish developed less steatosis and were totally protected from the development of fibrosis. Ovarian senescence significantly increases the risk of fibrosis severity both in humans with NAFLD and in zebrafish with experimental steatosis.

Dietary Supplementation of Genistein Alleviates Liver Inflammation and Fibrosis Mediated by a Methionine-Choline-Deficient Diet in db/db Mice

Nonalcoholic fatty liver disease is a complex disorder which includes simple steatosis, steatohepatitis, fibrosis and ultimately cirrhosis. Previous studies have reported that genistein, a soy phytoestrogen, attenuates steatohepatitis induced in obese and type 2 diabetic models. Here we investigated the effect of dietary genistein supplementation (0.05%) on nonalcoholic steatohepatitis (NASH) development induced by a methionine-choline-deficient (MCD) diet in db/db mice. MCD-diet-fed mice exhibited a significantly lower body weight and a higher degree of steatohepatitis with increased oxidative stress, steatosis, inflammation, stellate cell activation, and mild fibrosis. Although genistein did not inhibit hepatic steatosis, we observed that oxidative stress, endoplasmic reticulum stress, and AMP-dependent kinase inactivation were alleviated by genistein. Genistein also down-regulated the augmented gene expressions associated with hepatic inflammation and fibrosis. Therefore, these results suggest that genistein may protect MCD-diet-mediated NASH development by suppressing lipid peroxidation, inflammation, and even liver fibrosis in db/db mice.

Maternal effects underlie ageing costs of growth in the zebra finch (Taeniopygia guttata)

Maternal effects provide a mechanism to adapt offspring phenotype and optimize the mother's fitness to current environmental conditions. Transferring steroids to the yolk is one way mothers can translate environmental information into potential adaptive signals for offspring. However, maternally-derived hormones might also have adverse effects for offspring. For example, recent data in zebra finch chicks suggested that ageing related-processes (i.e. oxidative stress and telomere loss) were increased after egg-injection of corticosterone (CORT). Still, we have few experimental data describing the effect of maternal effects on the growth-ageing trade-off in offspring. Here, we chronically treated pre-laying zebra finch females (Taeniopygia guttata) with 17-β-estradiol (E2) or CORT, and followed offspring growth and cellular ageing rates (oxidative stress and telomere loss). CORT treatment decreased growth rate in male chicks and increased rate of telomere loss in mothers and female offspring. E2 increased body mass gain in male offspring, while reducing oxidative stress in both sexes but without affecting telomere loss. Since shorter telomeres were previously found to be a proxy of individual lifespan in zebra finches, maternal effects may, through pleiotropic effects, be important determinants of offspring life-expectancy by modulating ageing rate during embryo and post-natal growth.

Gender and menopause impact severity of fibrosis among patients with nonalcoholic steatohepatitis

Estrogens inhibit stellate cell activation and fibrogenesis. Thus, gender and reproductive states may influence the degree of fibrosis in patients with nonalcoholic steatohepatitis (NASH). To investigate the association between gender, menopause, and the severity of liver fibrosis in patients with NASH, we analyzed 541 adult patients enrolled from our Duke Liver Clinics (n = 338) and the Duke Metabolic and Weight Loss Surgery Program (n = 203) who had a histologic diagnosis of NASH. Multiple ordinal logistic regression models were used to assess the association between gender, menopause, and severity of liver fibrosis. Overall, men, premenopausal, and postmenopausal women composed 35.1%, 28.4%, and 36.5% of the population, respectively. The mean age was 48 years and 22% had advanced fibrosis. After adjusting for covariates (enrolling site, grades of portal inflammation, and hepatocyte ballooning) and potential confounders (race, body mass index, diabetes/prediabetes, hypertension), adjusted cumulative odd ratio (ACOR) and 95% confidence interval (CI) for greater fibrosis severity was 1.4 (0.9, 2.1) (P = 0.17) for postmenopausal women and 1.6 (1.0, 2.5) (P = 0.03) for men, having premenopausal women as a reference. There was borderline interaction between gender and age group divided by age 50, the average age at menopause in the U.S. (P = 0.08): ACOR and 95% CI of having greater fibrosis severity in men compared to women was 1.8 (1.1, 2.9) for patients with age <50 years (P = 0.02) and 1.2 (0.7, 2.1) for patients with age ≥50 years (P = 0.59).

CONCLUSION

Men are at a higher risk of having more severe fibrosis compared to women before menopause, while postmenopausal women have a similar severity of liver fibrosis compared to men. These findings may be explained by the protective effects of estrogen against fibrogenesis.

Estradiol and progesterone exhibit similar patterns of hepatic gene expression regulation in the bovine model

Female sex steroid hormones, estradiol-17β (E2-17β) and progesterone (P4) regulate reproductive function and gene expression in a broad range of tissues. Given the central role of the liver in regulating homeostasis including steroid hormone metabolism, we sought to understand how E2-17β and P4 interact to affect global gene expression in liver. Ovariectomized cows (n = 8) were randomly assigned to 4 treatment groups applied in a replicated Latin Square design: 1) No hormone supplementation, 2) E2-17β treatment (ear implant), 3) P4 treatment (intravaginal inserts), and 4) E2-17β combined with P4. After 14 d of treatment, liver biopsies were collected, allowing 28 d intervals between periods. Changes in gene expression in the liver biopsies were monitored using bovine-specific arrays. Treatment with E2-17β altered expression of 479 genes, P4 472 genes, and combined treatment significantly altered expression of 468 genes. In total, 578 genes exhibited altered expression including a remarkable number (346 genes) that responded similarly to E2-17β, P4, or combined treatment. Additional evidence for similar gene expression actions of E2-17ß and/or P4 were: principal component analysis placed almost every treatment array at a substantial distance from controls; Venn diagrams indicated overall treatment effects for most regulated genes; clustering analysis indicated the two major clusters had all treatments up-regulating (172 genes) or down-regulating (173 genes) expression. Thus, unexpectedly, common biological pathways were regulated by E2-17β and/or P4 in liver. This indicates that the mechanism of action of these steroid hormones in the liver might be either indirect or might occur through non-genomic pathways. This unusual pattern of gene expression in response to steroid hormones is consistent with the idea that there are classical and non-classical tissue-specific responses to steroid hormone actions. Future studies are needed to elucidate putative mechanism(s) responsible for overlapping actions of E2-17β and P4 on the liver transcriptome.

N-acetylcysteine attenuates cardiopulmonary bypass-induced lung injury in dogs

Background

Cardiopulmonary bypass (CPB) is usually associated with inflammatory response that leads to various degrees of organ dysfunction in multiple systems, including lung injury. Our previous study showed that transforming growth factor beta1 (TGFβ1) was involved in CPB-induced lung injury. N-acetylcysteine (NAC) is an antioxidant and is able to prevent CPB-induced pneumocyte apoptosis through scavenging radical. Therefore, we investigated whether NAC may attenuate CPB-induced lung injury by inhibiting TGFβ1 expression.

Methods

Fifty-four 18 to 24-month-old mongrel dogs (15–16 kg) were randomly divided into control group, CPB group and NAC group (n = 18). Six dogs in each group were killed prior to, as well as 30 and 60 minutes after the operation (T0, T1 and T2). Lung injury was evaluated by hematoxylin and eosin (H&E) staining. Respiratory index (RI), oxygenation index (OI), malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung were determined at each time point. TGFβ1 expression was determined using real time RT-PCR and immunohistochemistry.

Results

A serious lung injury was observed after CPB in dogs. RI and MDA content were increased significantly after CPB, whereas OI and SOD activity were decreased. H&E staining showed that NAC treatment obviously attenuated CPB-induced lung injury. NAC treatment upregulated OI and SOD activity and downregulated RI and MDA content in the lung tissues of dogs after CPB. Treatment with NAC significantly suppressed the TGFβ1 expression in the lung tissues at both mRNA and protein levels.

Conclusion

Our results suggest that NAC is a potent agent against CPB-induced acute lung injury through inhibiting TGFβ1 expression.

Estrogen derivatives: novel therapeutic agents for liver cirrhosis and portal hypertension

Sex differences in the incidence of liver cirrhosis and portal hypertension have been reported by epidemiological studies. Previous studies have indicated that estrogen therapy improved hepatic fibrosis, inhibited the activation of hepatic stellate cells, and reduced portal pressure, whereas the administration of exogenous estrogens resulted in some potential risks, limiting their clinical use. However, the biological actions of estrogens are mediated by three subtypes of estrogen receptors (ERs): ERα, ERβ, and G-protein-coupled ER. These ER subtypes act in distinct ways and exert different biological effects that mediate genomic and nongenomic events, resulting in tissue-specific responses. In addition, active estrogen metabolites, with little or no affinity for ERs, could mediate the fibrosuppressive effect of estrogens through an ER-independent pathway. Taken together, such specific estrogen derivatives as ER selective agonists, or active estrogen metabolites, would provide novel therapeutic opportunities, stratifying this hormonal treatment, thereby reducing undesired side-effects in the treatment of liver cirrhosis and portal hypertension.