Sex difference in liver diseases: How preclinical models help to dissect the sex-related mechanisms sustaining NAFLD and hepatocellular carcinoma

Sex differences in the association between total energy intake and all-cause mortality among patients with metabolic dysfunction-associated steatotic liver disease

The long-term association between total energy intake and clinical outcomes in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) remains unclear. The present study aimed to explore the associations between total energy intake and mortality in MASLD patients and to evaluate whether the associations differ by sex. A total of 2,466 MASLD patients from the Third National Health and Nutrition Examination Survey was included. Total energy intake was assessed using 24-hour dietary recall. Mortality was ascertained by linkage to National Death Index records through 31 December 2019. Multivariable Cox proportional hazards model was used to estimate the association between total energy intake and mortality. In MASLD patients, both low and high total energy intake were significantly associated with elevated risk of all-cause mortality. Compared with moderate total energy intake (2,000-3,000 kcal/day for males and 1,600-2,400 kcal/day for females), the HRs (95% CIs) for low and high total energy intake were 1.27 (1.05-1.53; P = 0.01) and 1.40 (1.03-1.92; P = 0.03), respectively. A significant interaction was demonstrated between sex and total energy intake for all-cause mortality (P value for interaction = 0.03). In males, both low and high total energy intake were significantly associated with elevated risk of all-cause mortality. The HRs (95% CIs) for low and high total energy intake were 1.35 (1.02-1.80; P = 0.04) and 1.54 (1.05-2.28; P = 0.03), respectively. However, no significant association was observed in females. The HRs (95% CIs) for low and high total energy intake were 1.14 (0.86-1.52; P = 0.34) and 1.14 (0.81-1.61; P = 0.46), respectively. These findings provide novel evidence supporting sex-specific dietary guidelines for MASLD, with particular emphasis on maintaining moderate energy intake to mitigate mortality risk in male patients.

Transcriptomic and lipidomic analysis of aging-associated inflammatory signature in mouse liver

BACKGROUND

Aging-associated dysbiosis leads to chronic inflammation and the development of a range of aging-related diseases. The gut microbiota crosstalks with the host by providing lipid metabolites and modulating metabolic functions. However, the precise mechanism by which the gut microbiota regulates aging is unknown. The objective of this study was to examine the impact of the gut microbiota on the transcriptome and lipidome associated with aging in mouse liver.

METHODS

RNA-sequencing was conducted on the livers of young and aged male and female-specific pathogen-free (SPF) and germ-free (GF) mice to comprehensively analyze transcriptomic alterations with aging. We also reanalyzed our previously reported results on aging-associated changes in the hepatic lipidome to investigate the gut microbiota-dependent hepatic lipidome signatures associated with aging.

RESULTS

In contrast to the findings in male mice, the changes in hepatic transcriptome associated with aging were attenuated in female GF mice compared with those in SPF mice. In particular, the gene sets associated with inflammatory signatures (i.e., inflammation and tissue remodeling) were found to be suppressed in female GF mice. The ChIP-Atlas database predicted that transcription factors associated with sex differences may be involved in the gene signature of aged female GF mice. Significant differences in the lipid profile were observed between aged SPF and GF female mice, including in bile acids, sterol sulfates, lysophospholipids, oxidized triacylglycerols, vitamin D, and phytoceramides. Moreover, notable alterations were identified in the quality of phospholipids and sphingolipids. Integrated transcriptomic and lipidomic analysis identified candidate enzymes responsible for the change of lipid profiles in aged female mice.

CONCLUSIONS

The findings of this study offer new insights into the molecular mechanisms through which the gut microbiota regulates aging-related phenotypes such as inflammation in the liver, possibly through modulating lipid metabolism in a sex-dependent manner.

Hallmarks of Cancer Cachexia: Sexual Dimorphism in Related Pathways

Cancer-associated cachexia (CAC), also known as wasting syndrome, is a systemic condition that affects multiple tissues and organs via a variety of metabolic pathways. Systemic inflammation, progressive weight loss, depletion of adipose tissue, and skeletal muscle impairment are some of the hallmark features of cachexia. Despite various studies on the clinical features of CAC, the complexity of the syndrome continues to pose significant challenges in clinical practice, leading to late diagnoses and the absence of a standardised treatment. Men and women respond differently to CAC, which may be prompted by the pre-existing physiologic sex differences. This review presents the sexual dimorphism associated with the hallmark pathways involved in CAC. A comprehensive understanding of sexual dimorphism in these pathways could drive research on cachexia to prioritise the inclusion of more females in related studies in order to achieve personalised sex-based therapeutic approaches and, consequently, enhance treatment efficacy and better patient outcomes.

Widespread discordance between mRNA expression, protein abundance and de novo lipogenesis activity in hepatocytes during the fed-starvation transition

The mammalian liver plays a critical role in maintaining metabolic homeostasis during fasting and feeding. Liver function is further shaped by sex dimorphism and zonation of hepatocytes. To explore how these factors interact, we performed deep RNA-sequencing and label-free proteomics on periportal and pericentral hepatocytes isolated from male and female mice under fed and starved conditions. We developed a classification system to assess protein-mRNA relationship and found that gene products (mRNA or protein) for most zonation markers showed strong concordance between mRNA and protein. Although classical growth hormone regulated sex-biased gene products also exhibited concordance, ∼60% of sex-biased gene products showed protein-level enrichment without corresponding mRNA differences. In contrast, transition between feeding and starvation triggered widespread changes in mRNA expression without significantly affecting protein levels. In particular, key lipogenic mRNAs (e.g. Acly , Acaca , and Fasn ) were dramatically induced by feeding, but their corresponding proteins (ACLY, ACC1, and FAS) showed little to no change even as functional de novo lipogenic activity increased ∼28-fold in the fed state. To facilitate further exploration of these findings, we developed Discorda ( https://shinoda-lab.shinyapps.io/discorda/ ), a web database for interactive analysis. Our findings reinforce the principle that mRNA changes do not reliably predict corresponding protein levels (and vice versa), particularly in the context of sex and acute metabolic regulation of hepatocytes, and that de novo lipogenesis activity can be completely uncoupled from changes in protein expression.

Liver Cancer Risk Across Metabolic Dysfunction-Associated Steatotic Liver Disease and/or Alcohol: A Nationwide Study

INTRODUCTION

New terminologies of metabolic dysfunction-associated steatotic liver disease (MASLD) have been developed. We assessed hepatocellular carcinoma (HCC) risk across MASLD and/or alcohol intake.

METHODS

We included participants aged 40-79 years receiving a national health checkup from 2009 to 2010 in the Republic of Korea, classified as follows: non-MASLD, MASLD, MASLD with increased alcohol intake (MetALD; weekly alcohol 210-420 g for male and 140-350 g for female individuals), and alcohol-associated liver disease (ALD; excessive alcohol intake with weekly alcohol ≥420 g for male or ≥350 g for female individuals). The primary outcome was HCC incidence. HCC risk was estimated using multivariable Cox proportional hazard models.

RESULTS

Among 6,412,209 participants, proportions of non-MASLD, MASLD, MetALD, and ALD cases were 59.5%, 32.4%, 4.8%, and 3.4%, respectively. During follow-up (median 13.3 years), 27,118 had newly developed HCC. Compared with non-MASLD, the HCC risk increased from MASLD (adjusted hazard ratio [aHR] 1.66, 95% confidence interval [CI] 1.62-1.71) and MetALD (aHR 2.17, 95% CI 2.08-2.27) to ALD (aHR 2.34, 95% CI 2.24-2.45) in a stepwise manner. Furthermore, the older and non-cirrhosis subgroups were more vulnerable to detrimental effects of MASLD and/or alcohol intake, concerning HCC risk. Among the older, female, and cirrhosis subgroups, MetALD poses similar HCC risks as ALD.

DISCUSSION

HCC risk increased from MASLD and MetALD to ALD in a stepwise manner, compared with non-MASLD. For an effective primary prevention of HCC, a comprehensive approach should be required to modify both metabolic dysfunction and alcohol intake habit.

Recipient-Donor Sex Constellation in Liver Transplantation for Hepatocellular Carcinoma-An ELTR Study

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Liver transplantation (LT) is a curative treatment option. We investigated survival outcomes based on recipient-donor sex constellation (RDSC) following LT.

METHODS

We performed a European Liver Transplant Registry analysis, including patients from 1988 to December 2022. The cohort was split into four RDSC groups: female donor female recipient (FDFR), female donor male recipient (FDMR), male donor female recipient (MDFR) and male donor male recipient (MDMR). Survival analysis, including death with recurrence, was performed.

RESULTS

In 7601 LT for HCC with an overall median follow-up of 22.6 months (5.8, 60.7), death was registered in 25.1% and, as primary cause of death, HCC tumour recurrence in 26.0%. There was no statistically significant difference on crude survival estimates among the different RDSC groups (log-rank p = 0.66) with 10-year overall survival (OS) of 54.5% in FDFR, 54.6% in FDMR, 59.1% in MDFR and 56.9% in MDMR. On multivariable analysis, RDSC showed a significant effect on OS (FDFR as reference): MDFR (aHR 0.72, p = 0.023). No significant difference was found for FDMR (aHR 0.98, p = 0.821) and MDMR (aHR 0.90, p= 0.288). Regarding overall registered causes of death, differences between RDSC groups were found in rejection (p = 0.017) and cardiovascular (p = 0.046) associated deaths.

CONCLUSIONS

In female recipients undergoing LT for HCC, male donor grafts were associated with a 28% reduction of mortality compared to female donor grafts.

Development of a novel diagnostic model to monitor the progression of metabolic dysfunction-associated steatotic liver disease to hepatocellular carcinoma in females

BACKGROUND AND AIMS

The onset of metabolic dysfunction-associated steatotic liver disease-associated hepatocellular carcinoma (MASLD-HCC) is insidious and exhibits sex-specific variations. Effective methods for monitoring MASLD-HCC progression in females have not yet been developed.

METHODS

Transcriptomic data of female liver tissue samples were obtained from multiple public databases. Differentially expressed genes (DEGs) in MASLD-HCC were identified using differential expression and robust rank aggregation analyses. Diagnostic prediction models for MASLD (DP.MASLD) and HCC (DP.HCC) were developed and validated using elastic net analysis, and diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. Bioinformatics was used to assess the pathogenesis of MASLD-HCC.

RESULTS

Seven overlapping DEGs were identified in female patients with MASLD and HCC: AKR1B10, CLEC1B, CYP2C19, FREM2, MT1H, NRG1, and THBS1). The area under the ROC curve (AUC) values for the training and validation groups of the DP.MASLD model were 0.864 and 0.782, 0.932 and 1.000, and 0.920 and 0.969 when differentiating between the steatosis and normal liver, steatohepatitis and steatosis, and steatohepatitis and normal liver groups, respectively. The AUCs for DP.HCC were 0.980 and 0.997 in the training and validation groups, respectively. The oncogenesis of female MASLD-HCC is associated with molecular pathways, including cytochrome P450-associated drug metabolism, tyrosine metabolism, fatty acid degradation, focal adhesion, extracellular matrix receptor interactions, and protein digestion and absorption.

CONCLUSION

A novel and effective method to quantitatively assess the risk of MASLD-HCC progression in female patients was developed, and this method will aid in the generation of precise diagnostic, preventive, and therapeutic strategies.

Fanlian Huazhuo Formula: A promising herbal preparation for metabolic liver disease

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) has increased significantly in recent decades and is projected to increase further due to the rising obesity rates. MASLD patients are at higher risk of developing advanced liver diseases "cirrhosis and hepatocellular carcinoma" as well as liver- or cardiovascular-related mortality. Existing lipid-lowering therapies failed to reduce the risk of mortality in these patients. Therefore, there is an urgent need for pharmacotherapies that can control and even reverse this disease. Fanlian Huazhuo Formula (FLHZF) is a combination herbal preparation, and its various individual constituents regulate hepatic lipid metabolism, adipose tissue inflammation, and gut microbiota. Despite, these useful effects, limited information is available on its benefits in diet-induced hepatosteatosis. In this article, we discuss the research findings recently published about the therapeutic effects of FLHZF in suppressing MASLD development and underlying mechanisms. Utilizing a series of in vitro and in vivo experiments, the authors demonstrated for the first time that FLHZF suppresses MASLD in male mice possibly by inhibiting hepatic de novo lipogenesis pathways and reducing hepatocyte death. This study paves the way for future investigations aimed at investigating FLHZF's role in inhibiting lipogenesis particularly using radioactively-labeled glucose and acetate, and governing hepatocyte mitochondrial function, gut microbiome profile, and its effects in other models of MASLD, and female mice.

Sexual dimorphism of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver condition. MASLD is a sexually dimorphic condition, with its development and progression influenced by sex chromosomes and hormones. Estrogens typically protect against, whereas androgens promote, MASLD. Therapeutic approaches for a sex-specific personalized medicine include estrogen replacement, androgen blockers, and novel drugs targeting hormonal pathways. However, the interactions between hormonal factors and inherited genetic variation impacts MASLD risk, necessitating more tailored therapies. Understanding sex disparities and the role of estrogens could improve MASLD interventions and management, whereas clinical trials addressing sex differences are crucial for advancing personalized treatment. This review explores the underappreciated impact of sexual dimorphism in MASLD and discusses the potential therapeutic application of sex-related hormones.

Evolving epidemiology of non-alcoholic fatty liver disease in South Korea: incidence, prevalence, progression, and healthcare implications from 2010 to 2022

BACKGROUND/AIMS

Non-alcoholic fatty liver disease (NAFLD), now the most common chronic liver worldwide, has become a significant public health concern. This study aims to analyze the evolving epidemiology of NAFLD in South Korea.

METHODS

We utilized claim data from the Korean National Health Insurance Service from 2010 to 2022 to analyze NAFLD's incidence, prevalence, and progression.

RESULTS

From 2010 to 2022, the incidence and prevalence rates of NAFLD each increased from 1.87% to 4.47% and from 10.49% to 17.13%, respectively. The differences in prevalence rates between urban and rural areas were minimal in 2012 and 2022, yet both areas showed significant increases in the prevalence of NAFLD over the decade. The NAFLD group had a higher prevalence of comorbidities compared to the control group, and the most common comorbid condition was hypertension. Moreover, the ten-year incidence rates of malignancy, heart disease, and stroke in the NAFLD group were 13.42%, 15.72%, and 8.36%, respectively, which were significantly higher than those in the control group. The incidence rates of cirrhosis and hepatocellular carcinoma in NAFLD over 10 years were 2.22% and 0.77%, respectively. The total medical costs of NAFLD patients more than doubled over ten years and were all significantly higher than those of the control group.

CONCLUSION

A significant increase in NAFLD prevalence and its impact on healthcare utilization was observed in South Korea. With NAFLD leading to serious liver diseases and increased healthcare costs, integrated care strategies that include both medical treatment and lifestyle modifications are essential.

Implications of innate immune sexual dimorphism for MASLD pathogenesis and treatment

Growing evidence suggests that metabolic dysfunction-associated steatotic liver disease (MASLD) is significantly higher in men versus women. Increased prevalence is observed in postmenopausal women, suggesting that age and sex (hormones) influence MASLD development and progression. Molecular data further reveal that sex regulates the innate immune responses with an essential role in MASLD progression. To date, there has been limited focus on the role of innate immune sexual dimorphism in MASLD, and differences between men and women are not considered in the current drug discovery landscape. In this review, we summarize the sex disparities and innate immune sexual dimorphism in MASLD pathogenesis. We further highlight the importance of harnessing sexual dimorphism in identifying therapeutic targets, developing pharmacological therapies, and designing (pre-) clinical studies for the personalized treatment for MASLD.

Shining a spotlight on sarcopenia and myosteatosis in liver disease and liver transplantation: Potentially modifiable risk factors with major clinical impact

Muscle-wasting and disease-related malnutrition are highly prevalent in patients with chronic liver diseases (CLD) as well as in liver transplant (LT) candidates. Alterations of body composition (BC) such as sarcopenia, myosteatosis and sarcopenic obesity and associated clinical frailty were tied to inferior clinical outcomes including hospital admissions, length of stay, complications, mortality and healthcare costs in various patient cohorts and clinical scenarios. In contrast to other inherent detrimental individual characteristics often observed in these complex patients, such as comorbidities or genetic risk, alterations of the skeletal muscle and malnutrition are considered as potentially modifiable risk factors with a major clinical impact. Even so, there is only limited high-level evidence to show how these pathologies should be addressed in the clinical setting. This review discusses the current state-of-the-art on the role of BC assessment in clinical outcomes in the setting of CLD and LT focusing mainly on sarcopenia and myosteatosis. We focus on the disease-related pathophysiology of BC alterations. Based on these, we address potential therapeutic interventions including nutritional regimens, physical activity, hormone and targeted therapies. In addition to summarizing existing knowledge, this review highlights novel trends, and future perspectives and identifies persisting challenges in addressing BC pathologies in a holistic way, aiming to improve outcomes and quality of life of patients with CLD awaiting or undergoing LT.

Cenicriviroc Suppresses and Reverses Steatohepatitis by Regulating Macrophage Infiltration and M2 Polarization in Mice

The inhibition of hepatic macrophage and Kupfer cell recruitment and activation is a potential strategy for treating insulin resistance and nonalcoholic steatohepatitis (NASH). Cenicriviroc (CVC), a dual C-C chemokine receptor 2 (CCR2) and CCR5 antagonist, has shown antifibrotic activity in murine models of NASH and has been evaluated in clinical trials on patients with NASH. This study investigated the effects of CVC on macrophage infiltration and polarization in a lipotoxic model of NASH. C57BL/6 mice were fed a high-cholesterol, high-fat (CL) diet or a CL diet containing 0.015% CVC (CL + CVC) for 12 weeks. Macrophage recruitment and activation were assayed by immunohistochemistry and flow cytometry. CVC supplementation attenuated excessive hepatic lipid accumulation and peroxidation and alleviated glucose intolerance and hyperinsulinemia in the mice that were fed the CL diet. Flow cytometry analysis revealed that compared with the CL group, mice fed the CL + CVC diet had fewer M1-like macrophages, more M2-like macrophages, and fewer T cell counts, indicating that CVC caused an M2-dominant shift of macrophages in the liver. Similarly, CVC decreased lipopolysaccharide-stimulated M1-like macrophage activation, whereas it increased interleukin-4-induced M2-type macrophage polarization in vitro. In addition, CVC attenuated hepatic fibrosis by repressing hepatic stellate cell activation. Lastly, CVC reversed insulin resistance as well as steatosis, inflammation, and fibrosis of the liver in mice with pre-existing NASH. In conclusion, CVC prevented and reversed hepatic steatosis, insulin resistance, inflammation, and fibrogenesis in the liver of NASH mice via M2 macrophage polarization.

Strength Training Protects High-Fat-Fed Ovariectomized Mice against Insulin Resistance and Hepatic Steatosis

Menopause is characterized by a reduction in sex hormones in women and is associated with metabolic changes, including fatty liver and insulin resistance. Lifestyle changes, including a balanced diet and physical exercise, are necessary to prevent these undesirable changes. Strength training (ST) has been widely used because of the muscle and metabolic benefits it provides. Our study aims to evaluate the effects of ST on hepatic steatosis and insulin resistance in ovariectomized mice fed a high-fat diet (HFD) divided into four groups as follows: simulated sedentary surgery (SHAM-SED), trained simulated surgery (SHAM-EXE), sedentary ovariectomy (OVX-SED), and trained ovariectomy (OVX-EXE). They were fed an HFD for 9 weeks. ST was performed thrice a week. ST efficiently reduced body weight and fat percentage and increased lean mass in OVX mice. Furthermore, ST reduced the accumulation of ectopic hepatic lipids, increased AMPK phosphorylation, and inhibited the de novo lipogenesis pathway. OVX-EXE mice also showed a better glycemic profile, associated with greater insulin sensitivity identified by the euglycemic-hyperinsulinemic clamp, and reduced markers of hepatic oxidative stress compared with sedentary animals. Our data support the idea that ST can be indicated as a non-pharmacological treatment approach to mitigate metabolic changes resulting from menopause.