Mechanistic studies of PEG-asparaginase-induced liver injury and hepatic steatosis in mice.
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SUBMITTER: Kumar GVN
PROVIDER: S-EPMC8727916 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:L-Asparaginase is a bacterial enzyme used in the treatment of acute lymphoblastic leukemia. In the ongoing U.S. Drug-Induced Liver Injury Network (DILIN) prospective study, standard and pegylated asparaginase were the most frequent cause of liver injury with jaundice among anti-cancer agents (8 of 40: 20%). The unique features of this hepatotoxicity are described. METHODS:Eight cases from 5 DILIN centers were reviewed for clinical course, laboratory values, imaging, and histopathology. RESULTS:Seven females, aged 29-59 years, and one 8-year-old boy, all with leukemia, developed jaundice within 9-21 days (median 15 days) of starting asparaginase or pegaspargase, during the first (n?=?6) or second (n?=?2) cycle. Prominent symptoms were jaundice (n?=?8), fatigue (6), abdominal pain (6) but rarely pruritus (1). Initial median ALT level was 284 U/L (range 83-1076), Alk P 159 U/L (64-452), and bilirubin 4.4 mg/dL (3.7-8.4). Bilirubin levels rose thereafter in all patients to median peak of 17.5 mg/dL (11.7-25.7), INR rose to 1.1-1.7 and serum albumin fell to 1.5-2.6 g/dL. Hepatic imaging revealed fatty liver in all patients. Liver biopsy showed steatosis but minimal hepatocyte necrosis. One patient restarted on pegaspargase re-developed less severe injury. CONCLUSION:Asparaginase is a common cause of antineoplastic-induced liver injury with jaundice, typically with short latency, marked steatosis, and prolonged jaundice, which can lead to delays in antileukemic therapy. The cause of injury is likely direct inhibition of hepatic protein synthesis caused by asparagine depletion.
| S-EPMC7226930 | biostudies-literature
Project description:Chronic alcohol consumption causes alcohol-induced lipogenesis and promotes hepatic injury by preventing the oxidation of hepatocellular fatty acids through the suppression of the activation of AMP-activated protein kinase (AMPK). HIMH0021, an active flavonoid compound, which is a component of the Acer tegmentosum extract, has been shown to protect against liver damage caused by alcohol consumption. Therefore, in this study, we aimed to determine whether HIMH0021 could regulate alcoholic fatty liver and liver injury in mice. Oral administration of 10 days of Lieber-DeCarli ethanol plus a single binge of 30% ethanol (chronic-plus-binge model) induced steatosis and liver injury and inflammation in mice, which appears similar to the condition observed in human patients with alcohol-related diseases. HIMH0021, which was isolated from the active methanol extract of A. tegmentosum, inhibited alcohol-induced steatosis and attenuated the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) during hepatocellular alcohol metabolism, both of which promote lipogenesis as well as liver inflammation. Treatment with HIMH0021 conferred protection against lipogenesis and liver injury, inhibited the expression of cytochrome P4502E1, and increased serum adiponectin levels in the mice subjected to chronic-plus-binge feeding. Furthermore, in hepatocytes, HIMH0021 activated fatty acid oxidation by activating pAMPK, which comprises pACC and CPT1a. These findings suggested that HIMH0021 could be used to target a TNFα-related pathway for treating patients with alcoholic hepatitis.
| S-EPMC5665428 | biostudies-literature
Project description:Chronic alcohol consumption causes liver injury, inflammation and fibrosis, thereby increasing morbidity and mortality. Paradoxically, modest drinking is believed to confer metabolic improvement, but the underlying mechanism remains elusive. Here, we have identified a novel hepatoprotective brain/brown adipose tissue (BAT)/liver axis. Alcohol consumption or direct alcohol administration into the brain stimulated hypothalamic neural circuits and sympathetic nerves innervating BAT, and dramatically increased BAT uncoupling protein 1 (Ucp1) expression and activity in a BAT sympathetic nerve-dependent manner. BAT and beige fat oxidized fatty acids to fuel Ucp1-mediated thermogenesis, thereby inhibiting lipid trafficking into the liver. BAT also secreted several adipokines, including adiponectin that suppressed hepatocyte injury and death. Genetic deletion of Ucp1 profoundly augmented alcohol-induced liver steatosis, injury, inflammation and fibrosis in male and female mice. Conversely, activation of BAT and beige fat through cold exposure suppressed alcoholic liver disease development. Our results unravel an unrecognized brain alcohol-sensing/sympathetic nerve/BAT/liver axis that counteracts liver steatosis and injury.
| S-EPMC6546460 | biostudies-literature
Project description:Key pointsNon-alcoholic fatty liver disease, characterized in part by elevated liver triglycerides (i.e. hepatic steatosis), is a growing health problem. In this study, we found that hepatic steatosis is associated with robust hepatic sympathetic overactivity. Removal of hepatic sympathetic nerves reduced obesity-induced hepatic steatosis. Liver sympathetic innervation modulated hepatic lipid acquisition pathways during obesity.AbstractNon-alcoholic fatty liver disease (NAFLD) affects 1 in 3 Americans and is a significant risk factor for type II diabetes mellitus, insulin resistance and hepatic carcinoma. Characterized in part by excessive hepatic triglyceride accumulation (i.e. hepatic steatosis), the incidence of NAFLD is increasing - in line with the growing obesity epidemic. The role of the autonomic nervous system in NAFLD remains unclear. Here, we show that chronic hepatic sympathetic overactivity mediates hepatic steatosis. Direct multiunit recordings of hepatic sympathetic nerve activity were obtained in high fat diet and normal chow fed male C57BL/6J mice. To reduce hepatic sympathetic nerve activity we utilized two approaches including pharmacological ablation of the sympathetic nerves and phenol-based hepatic sympathetic nerve denervation. Diet-induced NAFLD was associated with a nearly doubled firing rate of the hepatic sympathetic nerves, which was largely due to an increase in efferent nerve traffic. Furthermore, established high fat diet-induced hepatic steatosis was effectively reduced with pharmacological or phenol-based removal of the hepatic sympathetic nerves, independent of changes in body weight, caloric intake or adiposity. Ablation of liver sympathetic nerves was also associated with improvements in liver triglyceride accumulation pathways including free fatty acid uptake and de novo lipogenesis. These findings highlight an unrecognized pathogenic link between liver sympathetic outflow and hepatic steatosis and suggest that manipulation of the liver sympathetic nerves may represent a novel therapeutic strategy for NAFLD.
| S-EPMC6716997 | biostudies-literature
Project description:ObjectiveTo identify metabolic pathways that may underlie susceptibility or resistance to high-fat diet-induced hepatic steatosis.Research design and methodsWe performed comparative transcriptomic analysis of the livers of A/J and C57Bl/6 mice, which are, respectively, resistant and susceptible to high-fat diet-induced hepatosteatosis and obesity. Mice from both strains were fed a normal chow or a high-fat diet for 2, 10, and 30 days, and transcriptomic data were analyzed by time-dependent gene set enrichment analysis. Biochemical analysis of mitochondrial respiration was performed to confirm the transcriptomic analysis.ResultsTime-dependent gene set enrichment analysis revealed a rapid, transient, and coordinate upregulation of 13 oxidative phosphorylation genes after initiation of high-fat diet feeding in the A/J, but not in the C57Bl/6, mouse livers. Biochemical analysis using liver mitochondria from both strains of mice confirmed a rapid increase by high-fat diet feeding of the respiration rate in A/J but not C57Bl/6 mice. Importantly, ATP production was the same in both types of mitochondria, indicating increased uncoupling of the A/J mitochondria.ConclusionsTogether with previous data showing increased expression of mitochondrial ?-oxidation genes in C57Bl/6 but not A/J mouse livers, our present study suggests that an important aspect of the adaptation of livers to high-fat diet feeding is to increase the activity of the oxidative phosphorylation chain and its uncoupling to dissipate the excess of incoming metabolic energy and to reduce the production of reactive oxygen species. The flexibility in oxidative phosphorylation activity may thus participate in the protection of A/J mouse livers against the initial damages induced by high-fat diet feeding that may lead to hepatosteatosis.
| S-EPMC3161312 | biostudies-literature
Project description:ObjectivePARKIN is an E3 ubiquitin ligase that regulates mitochondrial quality control through a process called mitophagy. Recent human and rodent studies suggest that loss of hepatic mitophagy may occur during the pathogenesis of obesity-associated fatty liver and contribute to changes in mitochondrial metabolism associated with this disease. Whole-body Prkn knockout mice are paradoxically protected against diet-induced hepatic steatosis; however, liver-specific effects of Prkn deficiency cannot be discerned in this model due to pleotropic effects of germline Prkn deletion on energy balance and subsequent protection against diet-induced obesity. We therefore generated the first liver-specific Prkn knockout mouse strain (LKO) to directly address the role of hepatic Prkn.MethodsLittermate control (WT) and LKO mice were fed regular chow (RC) or high-fat diet (HFD) and changes in body weight and composition were measured over time. Liver mitochondrial content was assessed using multiple, complementary techniques, and mitochondrial respiratory capacity was assessed using Oroboros O2K platform. Liver fat was measured biochemically and assessed histologically, while global changes in hepatic gene expression were measured by RNA-seq. Whole-body and tissue-specific insulin resistance were assessed by hyperinsulinemic-euglycemic clamp with isotopic tracers.ResultsLiver-specific deletion of Prkn had no effect on body weight or adiposity during RC or HFD feeding; however, hepatic steatosis was increased by 45% in HFD-fed LKO compared with WT mice (P < 0.05). While there were no differences in mitochondrial content between genotypes on either diet, mitochondrial respiratory capacity and efficiency in the liver were significantly reduced in LKO mice. Gene enrichment analyses from liver RNA-seq results suggested significant changes in pathways related to lipid metabolism and fibrosis in HFD-fed Prkn knockout mice. Finally, whole-body insulin sensitivity was reduced by 35% in HFD-fed LKO mice (P < 0.05), which was primarily due to increased hepatic insulin resistance (60% of whole-body effect; P = 0.11).ConclusionsThese data demonstrate that PARKIN contributes to mitochondrial homeostasis in the liver and plays a protective role against the pathogenesis of hepatic steatosis and insulin resistance.
| S-EPMC7399260 | biostudies-literature
Project description:Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in mammalian nicotinamide adenine dinucleotide (NAD)+ biosynthesis. Through its NAD+-biosynthetic activity, NAMPT influences the activity of NAD+-dependent enzymes, such as sirtuins. NAMPT is able to modulate processes involved in the pathogenesis of non-alcohol induced fatty liver disease (NAFLD), but the roles NAMPT plays in development of alcoholic liver disease (ALD) still remain unknown. Here, we show that ethanol treatment suppresses the expression of Nampt in hepatocytes. Consistently, chronic ethanol administration also reduces Nampt expression in the mouse liver. We next demonstrate that hepatocytes infected with Ad-NAMPT adenovirus exhibit significantly elevated intracellular NAD+ levels and decreased ethanol-induced triglyceride (TG) accumulation. Similarly, adenovirus-mediated overexpression of NAMPT in mice ameliorates ethanol induced hepatic steatosis. Moreover, we demonstrate that SIRT1 is required to mediate the effects of NAMPT on reduction of hepatic TG accumulation and serum ALT, AST levels in ethanol-fed mice. Our results provide important insights in targeting NAMPT for treating alcoholic fatty liver disease.
| S-EPMC6386387 | biostudies-literature
Project description:Nonalcoholic fatty liver disease (NAFLD) is becoming the most common indication for liver transplantation. The growing prevalence of NAFLD not only increases the demand for liver transplantation, but it also limits the supply of available organs because steatosis predisposes grafts to ischemia/reperfusion injury (IRI) and many steatotic grafts are discarded. We have shown that monoacylglycerol acyltransferase (MGAT) 1, an enzyme that converts monoacylglycerol to diacylglycerol, is highly induced in animal models and patients with NAFLD and is an important mediator in NAFLD-related insulin resistance. Herein, we sought to determine whether Mogat1 (the gene encoding MGAT1) knockdown in mice with hepatic steatosis would reduce liver injury and improve liver regeneration following experimental IRI. Antisense oligonucleotides (ASO) were used to knockdown the expression of Mogat1 in a mouse model of NAFLD. Mice then underwent surgery to induce IRI. We found that Mogat1 knockdown reduced hepatic triacylglycerol accumulation, but it unexpectedly exacerbated liver injury and mortality following experimental ischemia/reperfusion surgery in mice on a high-fat diet. The increased liver injury was associated with robust effects on the hepatic transcriptome following IRI including enhanced expression of proinflammatory cytokines and chemokines and suppression of enzymes involved in intermediary metabolism. These transcriptional changes were accompanied by increased signs of oxidative stress and an impaired regenerative response. We have shown that Mogat1 knockdown in a mouse model of NAFLD exacerbates IRI and inflammation and prolongs injury resolution, suggesting that Mogat1 may be necessary for liver regeneration following IRI and that targeting this metabolic enzyme will not be an effective treatment to reduce steatosis-associated graft dysfunction or failure.
| S-EPMC7785593 | biostudies-literature
Project description:The interaction between fat deposition and inflammation during obesity contributes to the development of non-alcoholic fatty liver disease (NAFLD). The present study examined the effects of palmitoleate, a monounsaturated fatty acid (16:1n7), on liver metabolic and inflammatory responses, and investigated the mechanisms by which palmitoleate increases hepatocyte fatty acid synthase (FAS) expression. Male wild-type C57BL/6J mice were supplemented with palmitoleate and subjected to the assays to analyze hepatic steatosis and liver inflammatory response. Additionally, mouse primary hepatocytes were treated with palmitoleate and used to analyze fat deposition, the inflammatory response, and sterol regulatory element-binding protein 1c (SREBP1c) activation. Compared with controls, palmitoleate supplementation increased the circulating levels of palmitoleate and improved systemic insulin sensitivity. Locally, hepatic fat deposition and SREBP1c and FAS expression were significantly increased in palmitoleate-supplemented mice. These pro-lipogenic events were accompanied by improvement of liver insulin signaling. In addition, palmitoleate supplementation reduced the numbers of macrophages/Kupffer cells in livers of the treated mice. Consistently, supplementation of palmitoleate decreased the phosphorylation of nuclear factor kappa B (NF-?B, p65) and the expression of proinflammatory cytokines. These results were recapitulated in primary mouse hepatocytes. In terms of regulating FAS expression, treatment of palmitoleate increased the transcription activity of SREBP1c and enhanced the binding of SREBP1c to FAS promoter. Palmitoleate also decreased the phosphorylation of NF-?B p65 and the expression of proinflammatory cytokines in cultured macrophages. Together, these results suggest that palmitoleate acts through dissociating liver inflammatory response from hepatic steatosis to play a unique role in NAFLD.
| S-EPMC3387145 | biostudies-literature
Project description: Not available
| S-EPMC10046991 | biostudies-literature