Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fatty liver is a common predisposing risk factor for postoperative liver failure and accounts for most discarded livers during triage of donors. We investigated the effect of heat shock preconditioning (HPc) on recipient survival in a rat fatty liver transplantation model. Fatty liver donor rats were exposed to brief whole-body hyperthermia (10 minutes at 42.5 degrees C) and allowed to recover. HPc induced heat shock proteins (HSPs) (HSP72, HSP90, and heme oxygenase [HO]-1) in donor livers, with levels peaking 12 to 48 hours after HPc. Subsequently, donor livers were harvested 24 hours after HPc, placed in cold storage for 10 hours, and transplanted into normal rats. At 3 hours posttransplantation, HPc reduced serum liver enzymes in the recipients and almost completely suppressed the release of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10. Histologic evaluation 3 and 24 hours after transplantation showed that HPc significantly reduced hepatic inflammation and hepatocellular necrosis without affecting the steatotic appearance of hepatocytes. One week after transplantation, control non-heat-shocked and heat-shocked fatty liver recipients exhibited survival rates of less than 10% and more than 80%, respectively. The evaluation of the survival of recipients receiving fatty livers at different times after HPc showed that the protective effect of HPc was significant when donor livers were transplanted 3 to 48 hours after HPc, with the maximum effect seen 6 to 48 hours after HPc. In conclusion, HPc is a promising avenue to salvage rejected donor fatty livers and enhance the survival rate of fatty liver recipients. We estimate that this technique could increase the annual donor pool by 600 livers.
 ...
PMID:Technique for expanding the donor liver pool: heat shock preconditioning in a rat fatty liver model. 1476 65

Disturbed microcirculation caused by fat accumulation in hepatocytes has been implicated in poor graft preservation and reperfusion. The aim of this study was to investigate the effect of vascular bed expansion (VBE) during cold preservation in graft survival Moderate liver steatosis in male Wistar rats (240-280 g) was induced by choline-deficient diet. Normal, steatotic or VBE-pretreated steatotic grafts were transplanted after 1 h or 9 h of cold preservation. Graft viability was determined by 7-day survival, serum liver enzymes, plasma tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, and malondialdehyde (MDA) levels. Post-reperfusion bile flow and liver histology were also examined. After 9 h of preservation, VBE-pretreated steatotic liver grafts were associated with significantly reduced serum liver enzyme, plasma TNF-alpha, IL-6, and MDA levels, as well as increased bile flow and higher survival rates compared with untreated ones. The present study shows that VBE protects fatty liver grafts from subsequent long-term cold preservation and reperfusion injury in a rat liver transplantation model.
 ...
PMID:The effects of vascular bed expansion in steatotic rat liver graft viability. 1510 72

Living-donor liver transplantation (LDLT) in adults has been expanded after becoming the standard for children in many transplant centres. Advantages of LDLT include thorough donor screening, optimization of timing for transplantation and minimal cold ischaemia time. However, the risk of donor morbidity and mortality must be considered. The preoperative evaluation of the donor typically is performed in consecutive stages. Specific donor considerations in LDLT are thrombosis and embolism, hepatic mass and hepatic steatosis. After complete evaluation, only a small proportion of potential donors are satisfactory candidates. The evaluation protocol for LDLT recipients in most centres is not different from that of cadaveric transplantation. More experience and the development of specific selection and evaluation criteria will further increase the benefit for the recipient and decrease the risk of the donor.
 ...
PMID:Living-donor liver transplantation: evaluation of donor and recipient. 1524 Aug 43

Hepatic steatosis predisposes the liver to cold ischemia-warm reperfusion (CI/WR) injury by unclear mechanisms. Because hepatic steatosis has recently been associated with a lysosomal pathway of apoptosis, our aim was to determine whether this cell-death pathway contributes to CI/WR injury of steatotic livers. Wild-type and cathepsin B-knockout (Ctsb(-/-)) mice were fed the methionine/choline-deficient (MCD) diet for 2 wk to induce hepatic steatosis. Mouse livers were stored in the University of Wisconsin solution for 24 h at 4 degrees C and reperfused for 1 h at 37 degrees C in vitro. Immunofluorescence analysis of the lysosomal enzymes cathepsin B and D showed a punctated intracellular pattern consistent with lysosomal localization in wild-type mice fed a standard diet after CI/WR injury. In contrast, cathepsin B and D fluorescence became diffuse in livers from wild-type mice fed MCD diet after CI/WR, indicating that lysosomal permeabilization had occurred. Hepatocyte apoptosis was rare in both normal and steatotic livers in the absence of CI/WR injury but increased in wild-type mice fed an MCD diet and subjected to CI/WR injury. In contrast, hepatocyte apoptosis and liver damage were reduced in Ctsb(-/-) and cathepsin B inhibitor-treated mice fed the MCD diet following CI/WR injury. In conclusion, these findings support a prominent role for the lysosomal pathway of apoptosis in steatotic livers following CI/WR injury.
 ...
PMID:Cathepsin B inactivation attenuates hepatocyte apoptosis and liver damage in steatotic livers after cold ischemia-warm reperfusion injury. 1547 11

Mice deficient for either long-chain acyl-CoA dehydrogenase (LCAD-/-) or very-long-chain acyl-CoA dehydrogenase (VLCAD-/-) develop hepatic steatosis upon fasting, due to disrupted mitochondrial fatty acid oxidation. Moreover, neither mouse model can maintain core body temperature when exposed to cold. We investigated the effects of fasting and cold exposure on gene expression in these mice. Non-fasted LCAD-/- mice showed gene expression changes indicative of fatty liver, including elevated mRNA levels for peroxisome proliferator-activated receptor-gamma (PPARgamma) and genes involved in lipogenesis. In LCAD-/- and VLCAD-/- mice challenged with fasting and cold exposure, expression of fatty acid oxidation genes was elevated in liver, consistent with increased PPARalpha activity. This effect was not seen in brown adipose tissue, suggesting that expression of these genes may be regulated differently than in liver. The effect of acute cold exposure on expression of fatty acid oxidation genes was measured in peroxisome proliferator-activated receptor (PPAR)-alpha-deficient mice (PPARalpha-/-) and controls. In PPARalpha-/- mice, basal expression of the acyl-CoA dehydrogenases was reduced in liver but was not altered in brown adipose tissue. While cold altered the expression of PPARgamma, sterol-regulatory element binding protein-1 (SREBP-1), ATP citrate lyase, and the uncoupling proteins in brown adipose tissue from both PPARalpha-/- and control mice, fatty acid oxidation genes were unaffected. Thus, while fatty acid oxidation appears critical for non-shivering thermogenesis, expression of the acyl-CoA dehydrogenases is not influenced by cold exposure. Moreover, mitochondrial fatty acid oxidation genes are not regulated by PPARalpha in brown adipose tissue as they are in liver.
 ...
PMID:Differential induction of genes in liver and brown adipose tissue regulated by peroxisome proliferator-activated receptor-alpha during fasting and cold exposure in acyl-CoA dehydrogenase-deficient mice. 1563 94

The gene encoding the transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) was targeted in mice. PGC-1alpha null (PGC-1alpha(-/-)) mice were viable. However, extensive phenotyping revealed multi-system abnormalities indicative of an abnormal energy metabolic phenotype. The postnatal growth of heart and slow-twitch skeletal muscle, organs with high mitochondrial energy demands, is blunted in PGC-1alpha(-/-) mice. With age, the PGC-1alpha(-/-) mice develop abnormally increased body fat, a phenotype that is more severe in females. Mitochondrial number and respiratory capacity is diminished in slow-twitch skeletal muscle of PGC-1alpha(-/-) mice, leading to reduced muscle performance and exercise capacity. PGC-1alpha(-/-) mice exhibit a modest diminution in cardiac function related largely to abnormal control of heart rate. The PGC-1alpha(-/-) mice were unable to maintain core body temperature following exposure to cold, consistent with an altered thermogenic response. Following short-term starvation, PGC-1alpha(-/-) mice develop hepatic steatosis due to a combination of reduced mitochondrial respiratory capacity and an increased expression of lipogenic genes. Surprisingly, PGC-1alpha(-/-) mice were less susceptible to diet-induced insulin resistance than wild-type controls. Lastly, vacuolar lesions were detected in the central nervous system of PGC-1alpha(-/-) mice. These results demonstrate that PGC-1alpha is necessary for appropriate adaptation to the metabolic and physiologic stressors of postnatal life.
 ...
PMID:PGC-1alpha deficiency causes multi-system energy metabolic derangements: muscle dysfunction, abnormal weight control and hepatic steatosis. 1576 Feb 70

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inherited disorder of mitochondrial fatty acid beta-oxidation in humans. To better understand the pathogenesis of this disease, we developed a mouse model for MCAD deficiency (MCAD-/-) by gene targeting in embryonic stem (ES) cells. The MCAD-/- mice developed an organic aciduria and fatty liver, and showed profound cold intolerance at 4 degrees C with prior fasting. The sporadic cardiac lesions seen in MCAD-/- mice have not been reported in human MCAD patients. There was significant neonatal mortality of MCAD-/- pups demonstrating similarities to patterns of clinical episodes and mortality in MCAD-deficient patients. The MCAD-deficient mouse reproduced important aspects of human MCAD deficiency and is a valuable model for further analysis of the roles of fatty acid oxidation and pathogenesis of human diseases involving fatty acid oxidation.
 ...
PMID:Medium-chain acyl-CoA dehydrogenase deficiency in gene-targeted mice. 1612 Dec 56

The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta) has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO) was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT). Under ambient temperature conditions, PGC-1beta ablation was partially compensated by up-regulation of PGC-1alpha in BAT and white adipose tissue (WAT) that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1betaKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1beta was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1betaKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1betaKO mice have impaired mitochondrial function. Lack of PGC-1beta also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1beta plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress.
 ...
PMID:Ablation of PGC-1beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance. 2007 97

Chronic shortage of donor organs has led to acceptance of steatotic livers as grafts, although there is a higher risk of primary graft dysfunction. We herein report the beneficial impact of Polysol, a newly developed preservation solution, on cold storage of steatotic rat livers. Dietary hepatic steatosis was induced in Wistar rats by 2-day fasting and subsequent 3-day re-feeding with a fat-free, carbohydrate-rich diet. Fatty livers were retrieved, flushed and then stored at 4 degrees C for 24 hours with either HTK or Polysol. Functional integrity of the grafts was evaluated by isolated reperfusion with oxygenated Krebs-Henseleit buffer at 37 degrees C for 45 minutes in both groups. Polysol preservation resulted in significant reductions of not only parenchymal (AST (IU/L); 6728+/-824 in HTK vs. 3107+/-718 in Polysol; P < 0.001) but also mitochondrial (GLDH (IU/L); 3189+/-773 vs. 1282+/-365; P < 0.01) enzyme release throughout reperfusion. Moreover, PVP (16.9+/-2.7 vs. 7.8+/-1.5 mmHg; P < 0.05), hepatic O2 consumption (0.291+/-0.047 vs. 1.056+/-0.053 micromol/g liver/min; P < 0.001), tissue ATP content (0.695+/-0.086 vs. 1.340+/-0.157 micromol/g dry-liver; P < 0.005), bile production (0.79+/-0.11 vs. 4.08+/-0.66 microL/g liver/45-min; P < 0.001), malondialdehyde into the perfusate (1.922+/-0.198 vs. 0.573+/-0.094 nmol/L; P < 0.0001) and wet/dry-weight ratio of the liver tissues (5.20+/-0.31 vs. 3.85+/-0.15; P < 0.005) were all better preserved by Polysol. In line with these benefits, electron microscopy revealed that Polysol preservation substantially suppressed deleterious mitochondrial alterations in steatotic livers. In conclusion, cold storage using Polysol resulted in significantly better integrity and function of steatotic livers. Polysol, therefore, may be a new alternative especially for "marginal" organs.
 ...
PMID:Impact of polysol, a newly developed preservation solution, on cold storage of steatotic rat livers. 1711 34

Factors affecting cell viability, plating efficiency, and survival of hepatocytes after cryopreservation have been investigated. We focused especially on the effect of including trehalose and related oligosaccharides in the cryopreservation fluid. This was supplemented with either glucose, trehalose, maltotriose, or other sugars, in addition to dimethyl sulfoxide (10%) and first tested with primary rat hepatocytes cooled in a controlled rate freezer. After thawing, viability by trypan blue exclusion of cells frozen in oligosaccharide-supplemented medium was significantly higher than for those cryopreserved without oligosaccharides. Use of oligosaccharides with higher molecular weights resulted in greatest improvement in viability. Moreover, attachment and survival rates in plastic dishes were approximately 1.2-1.8-fold greater after freezing in the presence of di-, tri-, and tetrasaccharides. Human hepatocytes isolated from untransplantable liver showed the same tendency regarding viability, but cell adherence was not similarly improved by the addition of oligosaccharides. Possible reasons for these differences may be prior cell damage during extended cold ischemia of the human liver, donor age, or cell degradation caused by progression of fatty liver in humans, and/or species differences.
 ...
PMID:Improvement of hepatocyte viability after cryopreservation by supplementation of long-chain oligosaccharide in the freezing medium in rats and humans. 1729 96


<< Previous 1 2 3 4 5 6 7 8 Next >>