Acetaminophen induces accumulation of functional rat CYP3A via polyubiquitination dysfunction.
Ontology highlight
ABSTRACT:
SUBMITTER: Santoh M
PROVIDER: S-EPMC4761967 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Insulin secretion from pancreatic ?-cells is impaired in all forms of diabetes. The resultant hyperglycaemia has deleterious effects on many tissues, including ?-cells. Here we show that chronic hyperglycaemia impairs glucose metabolism and alters expression of metabolic genes in pancreatic islets. In a mouse model of human neonatal diabetes, hyperglycaemia results in marked glycogen accumulation, and increased apoptosis in ?-cells. Sulphonylurea therapy rapidly normalizes blood glucose levels, dissipates glycogen stores, increases autophagy and restores ?-cell metabolism. Insulin therapy has the same effect but with slower kinetics. Similar changes are observed in mice expressing an activating glucokinase mutation, in in vitro models of hyperglycaemia, and in islets from type-2 diabetic patients. Altered ?-cell metabolism may underlie both the progressive impairment of insulin secretion and reduced ?-cell mass in diabetes.
| S-EPMC5123088 | biostudies-literature
Project description:F-box and WD repeat domain containing 7 (FBXW7) acts as a substrate receptor of SKP1-CUL1-F-box (SCF) E3 ubiquitin ligase and plays crucial roles in the regulation of several cellular processes, including cell growth, division, and differentiation, by targeting diverse key regulators for degradation. However, its role in regulating cellular senescence remains elusive. Here, we found that FBXW7 inactivation by siRNA-based knockdown or CRISPR/Cas9-based knockout induced significant cellular senescence in p53 wild-type cells, but not in p53 mutant or null cells, along with activation of both the p53/p21 and p16INK4a/Rb pathways. Simultaneous p53 inactivation abrogated senescence and cell growth arrest induced by FBXW7 deficiency as well as the alteration of both the p53/p21 and p16INK4a/Rb pathways. Moreover, Fbxw7 deletion accelerated replicative senescence of primary mouse embryonic fibroblasts in a p53-dependent manner. In addition, FBXW7 deletion induced the senescence-associated secretory phenotype to trigger secondary senescence. Importantly, in a radiation-induced senescence mouse model, simultaneous deletion of p53 rescued accelerated senescence and aging caused by Fbxw7 loss. Thus, our study uncovered a novel role for FBXW7 in the regulation of senescence by eliminating p53.
| S-EPMC9475035 | biostudies-literature
Project description:Mitochondria are key contributors to the etiology of diseases associated with neuromuscular defects or neurodegeneration. How changes in cellular metabolism specifically impact neuronal intracellular processes and cause neuropathological events is still unclear. We here dissect the molecular mechanism by which mitochondrial dysfunction induced by Prel aberrant function mediates selective dendritic loss in Drosophila melanogaster class IV dendritic arborization neurons. Using in vivo ATP imaging, we found that neuronal cellular ATP levels during development are not correlated with the progression of dendritic loss. We searched for mitochondrial stress signaling pathways that induce dendritic loss and found that mitochondrial dysfunction is associated with increased eIF2α phosphorylation, which is sufficient to induce dendritic pathology in class IV arborization neurons. We also observed that eIF2α phosphorylation mediates dendritic loss when mitochondrial dysfunction results from other genetic perturbations. Furthermore, mitochondrial dysfunction induces translation repression in class IV neurons in an eIF2α phosphorylation-dependent manner, suggesting that differential translation attenuation among neuron subtypes is a determinant of preferential vulnerability.
| S-EPMC5346966 | biostudies-literature
Project description:Diabetic nephropathy is one of the major complications of diabetes and the major cause of end-stage renal disease. In this study we investigated the insulin deficiency (ID) induced changes in renal mesangial cells (MCs) and in the kidney of STZ-induced diabetic rats.Cultured rat renal MCs were incubated in ID media. Cell proliferation was analyzed using BrdU incorporation assay. The expression of insulin receptor (IR), insulin-like growth factor-1 receptor (IGF-1R), phosphorylated IGF-1R, fibronectin, and collagen IV was determined with Western blot analysis. STZ-induced diabetic rats were treated with an IGF-1R antagonist picropodophyllin (PPP, 20 mg·kg(-1)·d(-1), po) for 8 weeks. After the rats were euthanized, plasma and kidneys were collected. IGF-1 levels in renal cortex were measured with RT-PCR or ELISA. The morphological changes in the kidneys were also examined.Incubation in ID media significantly increased cell proliferation, the synthesis of fibronectin and collagen IV, and the expression of IGF-1 and IGF-1R and phosphorylated IGF-1R in renal MCs. Pretreatment of the cells with PPP (50 nmol/L) blocked ID-induced increases in cell proliferation and the synthesis of fibronectin and collagen IV; knockdown of IGF-1R showed a similar effect as PPP did. In contrast, treatment of the cells with IGF-1 (50 ng/mL) exacerbated ID-induced increases in cell proliferation. In the kidneys of diabetic rats, the expression of IGF-1, IGF-1R and phosphorylated IGF-1R were significantly elevated. Treatment of diabetic rats with PPP did not lower the blood glucose levels, but significantly suppressed the expression of TGF-β, fibronectin and collagen IV in the kidneys, the plasma levels of urinary nitrogen and creatinine, and the urinary protein excretion.Insulin deficiency increases the expression of IGF-1 and IGF-1R in renal MCs and the kidney of diabetic rats, which contributes to the development of diabetic nephropathy.
| S-EPMC4753370 | biostudies-other
Project description:ObjectiveMitochondrial dysfunction affects hepatic lipid homeostasis and promotes ROS generation. Copine7 (CPNE7) belongs to the ubiquitous copine family of calcium-dependent phospholipid binding proteins. CPNE7 has a high calcium ion binding affinity and the capacity to scavenge reactive oxygen species (ROS). A recent study reported that abnormalities in fatty acid and lipid metabolism were linked to the gene variant of CPNE7. Therefore, the purpose of this study is to examine the role of Cpne7 in hepatic lipid metabolism based on mitochondrial function.MethodsLipid metabolism, mitochondrial function, and ROS production were investigated in high-fat diet (HFD)-fed Cpne7-/- mice and H2O2-damaged HepG2 hepatocytes following CPNE7 silencing or overexpression.ResultsCpne7 deficiency promoted severe hepatic steatosis in the HFD-induced NAFLD model. More importantly, mitochondrial dysfunction was observed along with an imbalance of mitochondrial dynamics in the livers of HFD-fed Cpne7-/-mice, resulting in high ROS levels. Similarly, CPNE7-silenced HepG2 hepatocytes showed high ROS levels, mitochondrial dysfunction, and increased lipid contents. On the contrary, CPNE7-overexpressed HepG2 cells showed low ROS levels, enhanced mitochondrial function and decreased lipid contents under H2O2-induced oxidative stress.ConclusionsIn the liver, Cpne7 deficiency causes excessive ROS formation and mitochondrial dysfunction, which aggravates lipid metabolism abnormalities. These findings provide evidence that Cpne7 deficiency contributes to the pathogenesis of NAFLD, suggesting Cpne7 as a novel therapeutic target for NAFLD.
| S-EPMC10637907 | biostudies-literature
Project description:Smoking is a major preventable risk factor for atherosclerosis. However, the causative link between cigarette smoke and atherosclerosis remains to be established. The objective of this study is to characterize the role of GTP cyclohydrolase 1 (GTPCH1), the rate-limiting enzyme for de novo tetrahydrobiopterin (BH4) synthesis, in the smoking-accelerated atherosclerosis and the mechanism involved. In vitro, human umbilical vein endothelial cells were treated with nicotine, a major component of cigarette smoke, which reduced the mRNA and protein levels of GTPCH1 and led to endothelial dysfunction. GTPCH1 overexpression or sepiapterin could attenuate nicotine-reduced nitric oxide and -increased reactive oxygen species levels. Mechanistically, human antigen R (HuR) bound with the adenylateuridylate-rich elements of the GTPCH1 3' untranslated region and increased its stability; nicotine inhibited HuR translocation from the nucleus to cytosol, which downregulated GTPCH1. In vivo, nicotine induced endothelial dysfunction and promoted atherosclerosis in ApoE-/- mice, which were attenuated by GTPCH1 overexpression or BH4 supplement. Our findings may provide a novel and promising approach to atherosclerosis treatment.
| S-EPMC6201367 | biostudies-literature
Project description:Acetaminophen (APAP) overdose causes hepatotoxicity involving mitochondrial dysfunction and c-jun N-terminal kinase (JNK) activation. Because the safe limit of APAP dosing is controversial, our aim was to evaluate the role of the mitochondrial permeability transition (MPT) and JNK in mitochondrial dysfunction after APAP dosing considered nontoxic by criteria of serum alanine aminotransferase (ALT) release and histological necrosis in vivo. C57BL/6 mice were given APAP with and without the MPT inhibitor, N-methyl-4-isoleucine cyclosporin (NIM811), or the JNK inhibitor, SP600125. Fat droplet formation, cell viability, and mitochondrial function in vivo were monitored by intravital multiphoton microscopy. Serum ALT, liver histology, total JNK, and activated phospho(p)JNK were also assessed. High APAP (300?mg/kg) caused ALT release, necrosis, irreversible mitochondrial dysfunction, and hepatocellular death. By contrast, lower APAP (150?mg/kg) caused reversible mitochondrial dysfunction and fat droplet formation in hepatocytes without ALT release or necrosis. Mitochondrial protein N-acetyl-p-benzoquinone imine adducts correlated with early JNK activation, but irreversible mitochondrial depolarization and necrosis at high dose were associated with sustained JNK activation and translocation to mitochondria. NIM811 prevented cell death and/or mitochondrial depolarization after both high and low dose APAP. After low dose, SP600125 decreased mitochondrial depolarization. In conclusion, low dose APAP produces reversible MPT-dependent mitochondrial dysfunction and steatosis in hepatocytes without causing ALT release or necrosis, whereas high dose leads to irreversible mitochondrial dysfunction and cell death associated with sustained JNK activation. Thus, nontoxic APAP has the potential to cause transient mitochondrial dysfunction that may synergize with other stresses to promote liver damage and steatosis.
| S-EPMC5009618 | biostudies-literature
Project description:Toxicity related to acetaminophen is most encountered with the acute ingestion of large doses. However, toxicity may also result from chronic ingestion, even when recommended doses are administered over a prolonged period of time. We present the case of a 20-month-old female toddler who received therapeutic recommended doses of acetaminophen (oral or intravenous) following multiple surgical interventions for treatment of a tracheo-esophageal fistula following ingestion of a button battery. The potential role of chronic acetaminophen administration in the etiology of hepatoxicity is discussed and prevention strategies are presented.
| S-EPMC8244954 | biostudies-literature
Project description:Mitochondrial dysfunction is associated with familial Alzheimer's disease (fAD), and the accumulation of damaged mitochondria has been reported as an initial symptom that further contributes to disease progression. In the amyloidogenic pathway, the amyloid precursor protein (APP) is cleaved by β-secretase to generate a C-terminal fragment, which is then cleaved by γ-secretase to produce amyloid-beta (Aβ). The accumulation of Aβ and its detrimental effect on mitochondrial function are well known, yet the amyloid precursor protein-derived C-terminal fragments (APP-CTFs) contributing to this pathology have rarely been reported. We demonstrated the effects of APP-CTFs-related pathology using induced neural stem cells (iNSCs) from AD patient-derived fibroblasts. APP-CTFs accumulation was demonstrated to mainly occur within mitochondrial domains and to be both a cause and a consequence of mitochondrial dysfunction. APP-CTFs accumulation also resulted in mitophagy failure, as validated by increased LC3-II and p62 and inconsistent PTEN-induced kinase 1 (PINK1)/E3 ubiquitin ligase (Parkin) recruitment to mitochondria and failed fusion of mitochondria and lysosomes. The accumulation of APP-CTFs and the causality of impaired mitophagy function were also verified in AD patient-iNSCs. Furthermore, we confirmed this pathological loop in presenilin knockout iNSCs (PSEN KO-iNSCs) because APP-CTFs accumulation is due to γ-secretase blockage and similarly occurs in presenilin-deficient cells. In the present work, we report that the contribution of APP-CTFs accumulation is associated with mitochondrial dysfunction and mitophagy failure in AD patient-iNSCs as well as PSEN KO-iNSCs.
| S-EPMC8748980 | biostudies-literature
Project description:Mitochondria are best known as the essential intracellular organelles that host the homeostasis required for cellular survival, but they also have relevance in diverse disease-related conditions, including Alzheimer's disease (AD). Amyloid β (Aβ) peptide is the key molecule in AD pathogenesis, and has been highlighted in the implication of mitochondrial abnormality during the disease progress. Neuronal exposure to Aβ impairs mitochondrial dynamics and function. Furthermore, mitochondrial Aβ accumulation has been detected in the AD brain. However, the underlying mechanism of how Aβ affects mitochondrial function remains uncertain, and it is questionable whether mitochondrial Aβ accumulation followed by mitochondrial dysfunction leads directly to neuronal toxicity. This study demonstrated that an exogenous Aβ(1-42) treatment, when applied to the hippocampal cell line of mice (specifically HT22 cells), caused a deleterious alteration in mitochondria in both morphology and function. A clathrin-mediated endocytosis blocker rescued the exogenous Aβ(1-42)-mediated mitochondrial dysfunction. Furthermore, the mitochondria-targeted accumulation of Aβ(1-42) in HT22 cells using Aβ(1-42) with a mitochondria-targeting sequence induced the identical morphological alteration of mitochondria as that observed in the APP/PS AD mouse model and exogenous Aβ(1-42)-treated HT22 cells. In addition, subsequent mitochondrial dysfunctions were demonstrated in the mitochondria-specific Aβ(1-42) accumulation model, which proved indistinguishable from the mitochondrial impairment induced by exogenous Aβ(1-42)-treated HT22 cells. Finally, cellular toxicity was directly induced by mitochondria-targeted Aβ(1-42) accumulation, which mimics the apoptosis process in exogenous Aβ(1-42)-treated HT22 cells. Taken together, these results indicate that mitochondria-targeted Aβ(1-42) accumulation is the necessary and sufficient condition for Aβ-mediated mitochondria impairments, and leads directly to cellular death rather than along with other Aβ-mediated signaling alterations.
| S-EPMC3325919 | biostudies-literature