The Independent Association of Non-alcoholic Fatty Liver Disease With Incident Cardiovascular Disease: A GRADE Evaluation of the Evidence Through a Systematic Review and Meta-analysis

Cholesterol overload in macrophages drives metabolic dysfunction-associated steatohepatitis via inhibiting 7-dehydrocholesterol reductase in mice

BACKGROUND

Dietary cholesterol promotes metabolic dysfunction-associated steatohepatitis (MASH), with hepatic macrophages central to disease pathology. However, the mechanisms by which cholesterol-loaded macrophages influence MASH remain unclear.

METHODS

In this study, mice were fed a cholesterol-rich choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD). Hepatic cholesterol levels, inflammatory markers, and pro-inflammatory macrophage polarization were assessed. In vitro studies examined the impact of cholesterol on macrophage polarization, identifying 7-dehydrocholesterol reductase (DHCR7) as a key cholesterol- and inflammation-responsive enzyme. DHCR7 expression in macrophages from MASH patients and model mice was evaluated. Functional studies involving in vitro knockdown and overexpression experiments, were complemented using myeloid-specific DHCR7 knockout mice. RNA sequencing was performed on liver tissues from wild-type and DHCR7 knockout mice to identify affected signaling pathways.

RESULTS

CDAHFD-fed mice exhibited local cholesterol accumulation and a pro-inflammatory macrophage phenotype in the liver. Cholesterol overload in vitro promoted M1 polarization and liver inflammation, reversible by simvastatin. DHCR7 expression, responded to cholesterol and polarization state, was downregulated in M1-polarized and hepatic macrophages from MASH patients and mice. DHCR7 suppression promoted pro-inflammatory phenotype, while its overexpression showed anti-inflammatory effects. Myeloid-specific DHCR7 deficiency in CDAHFD-fed mice worsened liver inflammation and pro-inflammatory macrophage infiltration. RNA sequencing identified the phosphoinositide 3-kinase (PI3K) pathway in DHCR7-regulated effects, with DHCR7-PI3K axis activation mitigating cholesterol-driven inflammation.

CONCLUSIONS

These findings unveil novel mechanistic insights into MASH pathogenesis, suggesting targeting macrophage-specific DHCR7 activation may offer a promising therapeutic strategy for MASH.

Disparities in the Prevalence of Hospitalizations and In-Hospital Mortality Due to Acute Myocardial Infarction Among Patients with Non-Alcoholic Fatty Liver Disease: A Nationwide Retrospective Study

Background: Non-alcoholic liver disease (NAFLD) may be associated with cardiovascular diseases; however, only a few studies have analyzed this relationship. We aimed to assess the epidemiologic data and the association between NAFLD and acute myocardial infarction (AMI) in the United States. Methods: The National Inpatient Sample (NIS) database 2016-2019 was queried using ICD10-CM diagnostic codes to identify hospitalizations of AMI + NAFLD. Essential demographic variables were analyzed to determine the disparities in the prevalence of AMI hospitalizations and deaths among NAFLD patients. Univariate and multivariate logistic regression models determined the association between NAFLD and AMI hospitalizations and death. Results: Among the total 5450 NAFLD patients hospitalized with AMI, 5.11% (279) died. Females were less likely to be admitted and die due to AMI than males. Younger patients (<50) were less likely to be hospitalized and die than those ≥50. Compared to the white population, black patients were less likely; however, Hispanics, Asians, and Pacific Islanders were more likely to be hospitalized. Race was not found to affect hospital mortality. On multivariate analysis, NAFLD was associated with higher odds of AMI hospitalization [OR 1.55, 95% CI 1.51-1.60, p < 0.01] and death [OR 1.96, 95% CI 1.74-2.21, p < 0.01]. Conclusions: Older white males with NAFLD had a higher prevalence of AMI hospitalizations and mortality.

Exploring the Multifaceted Landscape of MASLD: A Comprehensive Synthesis of Recent Studies, from Pathophysiology to Organoids and Beyond

Non-alcoholic fatty liver disease (NAFLD) is a widespread contributor to chronic liver disease globally. A recent consensus on renaming liver disease was established, and metabolic dysfunction-associated steatotic liver disease, MASLD, was chosen as the replacement for NAFLD. The disease's range extends from the less severe MASLD, previously known as non-alcoholic fatty liver (NAFL), to the more intense metabolic dysfunction-associated steatohepatitis (MASH), previously known as non-alcoholic steatohepatitis (NASH), characterized by inflammation and apoptosis. This research project endeavors to comprehensively synthesize the most recent studies on MASLD, encompassing a wide spectrum of topics such as pathophysiology, risk factors, dietary influences, lifestyle management, genetics, epigenetics, therapeutic approaches, and the prospective trajectory of MASLD, particularly exploring its connection with organoids.