Induction of MASH in three-dimensional bioprinted human liver tissue.

Metabolic dysfunction-associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis (MASH), is a major risk factor for cirrhosis and hepatocellular carcinoma (HCC) and a leading cause of liver transplantation. MASH is caused by an accumulation of toxic fat molecules in the hepatocyte which leads to inflammation and fibrosis. Inadequate human "MASH in a dish" models have limited our advances in understanding MASH pathogenesis and in drug discovery.

Serum amyloid P (PTX2) attenuates hepatic fibrosis in mice by inhibiting the activation of fibrocytes and HSCs.

Background: Liver fibrosis is caused by chronic toxic or cholestatic liver injury. Fibrosis results from the recruitment of myeloid cells into the injured liver, the release of inflammatory and fibrogenic cytokines, and the activation of myofibroblasts, which secrete extracellular matrix, mostly collagen type I. Hepatic myofibroblasts originate from liver-resident mesenchymal cells, including HSCs and bone marrow-derived CD45+ collagen type I+ expressing fibrocytes.

Multi-modal analysis of human hepatic stellate cells identifies novel therapeutic targets for metabolic dysfunction-associated steatotic liver disease.

Background & Aims: Metabolic dysfunction-associated steatotic liver disease ranges from metabolic dysfunction-associated steatotic liver (MASL) to metabolic dysfunction-associated steatohepatitis (MASH) with fibrosis. Transdifferentiation of hepatic stellate cells (HSCs) into fibrogenic myofibroblasts plays a critical role in the pathogenesis of MASH liver fibrosis. We compared transcriptome and chromatin accessibility of human HSCs from NORMAL, MASL, and MASH livers at single-cell resolution.

Fibrosis, biomarkers and liver biopsy in AAT deficiency and relation to liver Z protein polymer accumulation.

Background And Aims: The course of adults with ZZ alpha-1-antitrypsin deficiency (AATD) liver disease is unpredictable. The utility of markers, including liver biopsy, is undefined.

Methods: A prospective cohort, including protocol liver biopsies, was enrolled to address these questions.

HIF-2α drives hepatic Kupffer cell death and proinflammatory recruited macrophage activation in nonalcoholic steatohepatitis.

Proinflammatory hepatic macrophage activation plays a key role in the development of nonalcoholic steatohepatitis (NASH). This involves increased embryonic hepatic Kupffer cell (KC) death, facilitating the replacement of KCs with bone marrow-derived recruited hepatic macrophages (RHMs) that highly express proinflammatory genes. Moreover, phago/efferocytic activity of KCs is diminished in NASH, enhancing liver inflammation.

Lipid-associated macrophages' promotion of fibrosis resolution during MASH regression requires TREM2.

While macrophage heterogeneity during metabolic dysfunction-associated steatohepatitis (MASH) has been described, the fate of these macrophages during MASH regression is poorly understood. Comparing macrophage heterogeneity during MASH progression vs regression, we identified specific macrophage subpopulations that are critical for MASH/fibrosis resolution. We elucidated the restorative pathways and gene signatures that define regression-associated macrophages and establish the importance of TREM2 macrophages during MASH regression.

Protocol to generate human liver spheroids to study liver fibrosis induced by metabolic stress.

Currently, there is no effective treatment for obesity and alcohol-associated liver diseases, partially due to the lack of translational human models. Here, we present a protocol to generate 3D human liver spheroids that contain all the liver cell types and mimic "livers in a dish." We describe strategies to induce metabolic and alcohol-associated hepatic steatosis, inflammation, and fibrosis.

Alcohol-Associated Liver Disease Outcomes: Critical Mechanisms of Liver Injury Progression.

Alcohol-associated liver disease (ALD) is a substantial cause of morbidity and mortality worldwide and represents a spectrum of liver injury beginning with hepatic steatosis (fatty liver) progressing to inflammation and culminating in cirrhosis. Multiple factors contribute to ALD progression and disease severity. Here, we overview several crucial mechanisms related to ALD end-stage outcome development, such as epigenetic changes, cell death, hemolysis, hepatic stellate cells activation, and hepatic fatty acid binding protein 4.

Role of Hepatic Stellate and Liver Sinusoidal Endothelial Cells in a Human Primary Cell Three-Dimensional Model of Nonalcoholic Steatohepatitis.

Nonalcoholic steatohepatitis (NASH) is an inflammatory and fibrotic liver disease that has reached epidemic proportions and has no approved pharmacologic therapies. Research and drug development efforts are hampered by inadequate preclinical models. This research describes a three-dimensional bioprinted liver tissue model of NASH built using primary human hepatocytes and nonparenchymal liver cells (hepatic stellate cells, liver sinusoidal endothelial cells, and Kupffer cells) from either healthy or NASH donors.

SREBP Regulation of Lipid Metabolism in Liver Disease, and Therapeutic Strategies.

Sterol regulatory element-binding proteins (SREBPs) are master transcription factors that play a crucial role in regulating genes involved in the biogenesis of cholesterol, fatty acids, and triglycerides. As such, they are implicated in several serious liver diseases, including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma (HCC). SREBPs are subject to regulation by multiple cofactors and critical signaling pathways, making them an important target for therapeutic interventions.

Alternatives to animal testing to assess MASH drugs and hepatotoxicity.

The Food and Drug Administration (FDA) Modernization Act 2.0 "allows for alternatives to animal testing for purposes of drug and biological product applications." This provides an opportunity to develop and improve alternatives to animal studies to assess drugs in the liver.

The Origin and Fate of Liver Myofibroblasts.

Liver fibrosis of different etiologies is a serious health problem worldwide. There is no effective therapy available for liver fibrosis except the removal of the underlying cause of injury or liver transplantation. Development of liver fibrosis is caused by fibrogenic myofibroblasts that are not present in the normal liver, but rather activate from liver resident mesenchymal cells in response to chronic toxic or cholestatic injury.

Developing a highly-reliable learning health system.

Multiple independent frameworks to support continuous improvement have been proposed to guide healthcare organizations. Two of the most visible are High-reliability Health care, (Chassin et al., 2013) which is emphasized by The Joint Commission, and Learning Health Systems, (Institute of Medicine, 2011) highlighted by the National Academy of Medicine.

Isolation of primary human liver cells from normal and nonalcoholic steatohepatitis livers.

Here, we present a protocol for isolating human hepatocytes and neural progenitor cells from normal and nonalcoholic steatohepatitis livers. We describe steps for perfusion for scaled-up liver cell isolation and optimization of chemical digestion to achieve maximal yield and cell viability. We then detail a liver cell cryopreservation and potential applications, such as the use of human liver cells as a tool to link experimental and translational research.

Human Hepatic Stellate Cells: Isolation and Characterization.

Liver fibrosis of different etiologies is characterized by activation of hepatic stellate cells (aHSCs) into collagen type I secreting myofibroblasts, which produce fibrous scar and make the liver fibrotic. aHSCs are the major source of myofibroblasts and, therefore, the primary targets of anti-fibrotic therapy. Despite extensive studies, targeting of aHSCs in patients provides challenges.

Candida albicans-specific Th17 cell-mediated response contributes to alcohol-associated liver disease.

Alcohol-associated liver disease is accompanied by intestinal mycobiome dysbiosis, yet the impacts on liver disease are unclear. We demonstrate that Candida albicans-specific T helper 17 (Th17) cells are increased in circulation and present in the liver of patients with alcohol-associated liver disease. Chronic ethanol administration in mice causes migration of Candida albicans (C.

The Role of Mesothelin in Activation of Portal Fibroblasts in Cholestatic Liver Injury.

Fibrosis is a common consequence of abnormal wound healing, which is characterized by infiltration of myofibroblasts and formation of fibrous scar. In liver fibrosis, activated Hepatic Stellate Cells (aHSCs) and activated Portal Fibroblasts (aPFs) are the major contributors to the origin of hepatic myofibroblasts. aPFs are significantly involved in the pathogenesis of cholestatic fibrosis, suggesting that aPFs may be a primary target for anti-fibrotic therapy in cholestatic injury.

Multiplex short tandem repeat profiling of immortalized hepatic stellate cell line Col-GFP HSC.

Misidentification, cross-contamination and genetic drift of continuous animal cell lines are persistent problems in biomedical research, leading to erroneous results and inconsistent or invalidated studies. The establishment of immortalized hepatic stellate cell line Col-GFP HSC was reported in PLoS One in the year 2013. In the present study a multi loci short tandem repeat signature for this cell line was established that allows for unique cell line authentication.

Metabolic Injury of Hepatocytes Promotes Progression of NAFLD and AALD.

Nonalcoholic liver disease is a component of metabolic syndrome associated with obesity, insulin resistance, and hyperlipidemia. Excessive alcohol consumption may accelerate the progression of steatosis, steatohepatitis, and fibrosis. While simple steatosis is considered a benign condition, nonalcoholic steatohepatitis with inflammation and fibrosis may progress to cirrhosis, liver failure, and hepatocellular cancer.

Aberrant iron distribution via hepatocyte-stellate cell axis drives liver lipogenesis and fibrosis.

Hepatocytes have important roles in liver iron homeostasis, abnormalities in which are tightly associated with liver steatosis and fibrosis. Here, we show that non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are characterized by iron-deficient hepatocytes and iron overload in hepatic stellate cells (HSCs). Iron deficiency enhances hepatocyte lipogenesis and insulin resistance through HIF2α-ATF4 signaling.

MiR-690 treatment causes decreased fibrosis and steatosis and restores specific Kupffer cell functions in NASH.

Nonalcoholic steatohepatitis (NASH) is a liver disease associated with significant morbidity. Kupffer cells (KCs) produce endogenous miR-690 and, via exosome secretion, shuttle this miRNA to other liver cells, such as hepatocytes, recruited hepatic macrophages (RHMs), and hepatic stellate cells (HSCs). miR-690 directly inhibits fibrogenesis in HSCs, inflammation in RHMs, and de novo lipogenesis in hepatocytes.

CRIg on liver macrophages clears pathobionts and protects against alcoholic liver disease.

Complement receptor of immunoglobulin superfamily (CRIg) is expressed on liver macrophages and directly binds complement component C3b or Gram-positive bacteria to mediate phagocytosis. CRIg plays important roles in several immune-mediated diseases, but it is not clear how its pathogen recognition and phagocytic functions maintain homeostasis and prevent disease. We previously associated cytolysin-positive Enterococcus faecalis with severity of alcohol-related liver disease.

PNPLA3 downregulation exacerbates the fibrotic response in human hepatic stellate cells.

Non-alcoholic steatohepatitis (NASH) results, in part, from the interaction of metabolic derangements with predisposing genetic variants, leading to liver-related complications and mortality. The strongest genetic determinant is a highly prevalent missense variant in patatin-like phospholipase domain-containing protein 3 (PNPLA3 p.I148M).

Mutation of the 5'-untranslated region stem-loop mRNA structure reduces type I collagen deposition and arterial stiffness in male obese mice.

Arterial stiffening, a characteristic feature of obesity and type 2 diabetes, contributes to the development and progression of cardiovascular diseases (CVD). Currently, no effective prophylaxis or therapeutics is available to prevent or treat arterial stiffening. A better understanding of the molecular mechanisms underlying arterial stiffening is vital to identify newer targets and strategies to reduce CVD burden.