Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022672 (acute tubular necrosis)
 2,175 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cellular stress, particularly in response to toxic and metabolic insults that perturb function of the endoplasmic reticulum (ER stress), is a powerful inducer of the transcription factor CHOP. The role of CHOP in the response of cells to injury associated with ER stress was examined in a murine deficiency model obtained by homologous recombination at the chop gene. Compared with the wild type, mouse embryonic fibroblasts (MEFs) derived from chop -/- animals exhibited significantly less programmed cell death when challenged with agents that perturb ER function. A similar deficit in programmed cells death in response to ER stress was also observed in MEFs that lack CHOP's major dimerization partner, C/EBPbeta, implicating the CHOP-C/EBP pathway in programmed cell death. An animal model for studying the effects of chop on the response to ER stress was developed. It entailed exposing mice with defined chop genotypes to a single sublethal intraperitoneal injection of tunicamycin and resulted in a severe illness characterized by transient renal insufficiency. In chop +/+ and chop +/- mice this was associated with the early expression of CHOP in the proximal tubules followed by the development of a histological picture similar to the human condition known as acute tubular necrosis, a process that resolved by cellular regeneration. In the chop -/- animals, in spite of the severe impairment in renal function, evidence of cellular death in the kidney was reduced compared with the wild type. The proximal tubule epithelium of chop -/- animals exhibited fourfold lower levels of TUNEL-positive cells (a marker for programmed cell death), and significantly less evidence for subsequent regeneration. CHOP therefore has a role in the induction of cell death under conditions associated with malfunction of the ER and may also have a role in cellular regeneration under such circumstances.
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PMID:CHOP is implicated in programmed cell death in response to impaired function of the endoplasmic reticulum. 953 36

Nephrotoxicity is the dose-limiting factor for colistin, but the exact mechanism is unknown. This study aimed to investigate the roles of the mitochondrial, death receptor, and endoplasmic reticulum pathways in colistin-induced nephrotoxicity. Mice were intravenously administered 7.5 or 15 mg of colistin/kg of body weight/day (via a 3-min infusion and divided into two doses) for 7 days. Renal function, oxidative stress, and apoptosis were measured. Representative biomarkers involved in the mitochondrial, death receptor, and endoplasmic reticulum pathways were investigated, and the key markers involved in apoptosis and autophagy were examined. After 7-day colistin treatment, significant increase was observed with blood urea nitrogen, serum creatinine, and malondialdehyde, while activities of superoxide dismutase (SOD) and catalase decreased in the kidneys. Acute tubular necrosis and mitochondrial dysfunction were detected, and colistin-induced apoptosis was characterized by DNA fragmentation, cleavage of poly(ADP-ribose) polymerase (PARP-1), increase of 8-hydroxydeoxyguanosine (8-OHdG), and activation of caspases (caspase-8, -9, and -3). It was evident that colistin-induced apoptosis involved the mitochondrial pathway (downregulation of Bcl-2 and upregulation of cytochrome C [cytC] and Bax), death receptor pathway (upregulation of Fas, FasL, and Fas-associated death domain [FADD]), and endoplasmic reticulum pathway (upregulation of Grp78/Bip, ATF6, GADD153/CHOP, and caspase-12). In the 15-mg/kg/day colistin group, expression of the cyclin-dependent kinase 2 (CDK2) and phosphorylated JNK (p-JNK) significantly increased (P < 0.05), while in the 7.5-mg/kg/day colistin group, a large number of autophagolysosomes and classic autophagy were observed. Western blot results of Beclin-1 and LC3B indicated that autophagy may play a protective role in colistin-induced nephrotoxicity. In conclusion, this is the first study to demonstrate that all three major apoptosis pathways and autophagy are involved in colistin-induced nephrotoxicity.
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PMID:Colistin-induced nephrotoxicity in mice involves the mitochondrial, death receptor, and endoplasmic reticulum pathways. 2479 92

Rasburicase is a recombinant urate-oxidase enzyme and is a very important medication for tumor lysis syndrome. Methemoglobinemia and hemolysis are known side effects of rasburicase that result from oxidative stress caused by hydrogen peroxide, a byproduct generated during the breakdown of uric acid to allantoin. Patients with G6PD deficiency have a decreased tolerance to oxidative stress and are therefore at a greater risk of hemolysis and methemoglobinemia with rasburicase. Our patient is a 56-year-old Caucasian male with a recent diagnosis of grade 2-3a non-Hodgkin's lymphoma who presented to our emergency department with shortness of breath and dark discoloration of urine. Patient was discharged 36 hours ago from our hospital after he was given a first course of R-CHOP regimen and a dose of rasburicase. On further evaluation, patient was found to have severe anemia with hemolytic picture, hyperkalemia and acute kidney injury. He also had a discrepancy of the transcutaneous saturation (75%) and the saturation in an arterial blood gas value (99%). His methemoglobin level was found to be 11.9%. We were aware that methylene blue is a contraindication in patients with G6PD deficiency but considering patient being Caucasian and low risk for it and his deteriorating respiratory condition, it was decided to offer the treatment and patient received 1 dose of methylene blue which failed to improve his methemoglobinemia. He was also given vitamin C and 8 units of packed red blood cell throughout his stay in the hospital. Patient's hospital course was complicated by ARDS needed to be on mechanical ventilation support for 4 days and acute renal failure secondary to pigment nephropathy and acute tubular necrosis which required a hemodialysis support. Even if rasburicase induced methemoglobinemia and hemolysis are not very common complications, clinicians who prescribe and follow patients should detect this serious complication early and manage it accordingly. Our case can be used as a reminder that patients should be followed closely and given the right instructions on discharge to treat these complications which are associated with severe consequences. It is also vital to assume a diagnosis of G6PD deficiency until proven otherwise in a patient who presents with rasburicase induced hemolysis and avoid administration of methylene blue even if the patient is from a low risk ethnicity for G6PD as in our patient.
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PMID:Rasburicase induced severe hemolysis and methemoglobinemia in a Caucasian patient complicated by acute renal failure and ARDS. 3060 5