Progress of mitochondrial and endoplasmic reticulum-associated signaling and its regulation of chronic liver disease by Chinese medicine

The endoplasmic reticulum(ER)is connected to mitochondria through mitochondria-associated ER membranes(MAMs).MAMs provide a framework for crosstalk between the ER and mitochondria,playing a crucial role in regulating cellular calcium balance,lipid metabolism,and cell death.Dysregulation of MAMs is involved in the development of chronic liver disease(CLD).In CLD,changes in MAMs structure and function occur due to factors such as cellular stress,inflammation,and oxidative stress,leading to abnormal interactions between mitochondria and the ER,resulting in liver cell injury,fibrosis,and impaired liver function.Traditional Chinese medicine has shown some research progress in regulating MAMs signaling and treating CLD.This paper reviews the literature on the association between mitochondria and the ER,as well as the intervention of traditional Chinese medicine in regulating CLD.

Mitochondrial dysfunction affects hepatic immune and metabolic remodeling in patients with hepatitis B virus-related acute-onchronic liver failure

BACKGROUND Immune dysregulation and metabolic derangement have been recognized as key factors that contribute to the progression of hepatitis B virus(HBV)-related acute-on-chronic liver failure(ACLF).However,the mechanisms underlying immune and metabolic derangement in patients with advanced HBV-ACLF are unclear.AIM To identify the bioenergetic alterations in the liver of patients with HBV-ACLF causing hepatic immune dysregulation and metabolic disorders.METHODS Liver samples were collected from 16 healthy donors(HDs)and 17 advanced HBV-ACLF patients who were eligible for liver transplantation.The mitochondrial ultrastructure,metabolic characteristics,and immune microenvironment of the liver were assessed.More focus was given to organic acid metabolism as well as the function and subpopulations of macrophages in patients with HBV-ACLF.RESULTS Compared with HDs,there was extensive hepatocyte necrosis,immune cell infiltration,and ductular reaction in patients with ACLF.In patients,the liver suffered severe hypoxia,as evidenced by increased expression of hypoxia-inducible factor-1α.Swollen mitochondria and cristae were observed in the liver of patients.The number,length,width,and area of mitochondria were adaptively increased in hepatocytes.Targeted metabolomics analysis revealed that mitochondrial oxidative phosphorylation decreased,while anaerobic glycolysis was enhanced in patients with HBV-ACLF.These findings suggested that,to a greater extent,hepa-tocytes used the extra-mitochondrial glycolytic pathway as an energy source.Patients with HBV-ACLF had elevated levels of chemokine C-C motif ligand 2 in the liver homogenate,which stimulates peripheral monocyte infiltration into the liver.Characterization and functional analysis of macrophage subsets revealed that patients with ACLF had a high abundance of CD68^(+)HLA-DR^(+)macrophages and elevated levels of both interleukin-1βand transforming growth factor-β1 in their livers.The abundance of CD206^(+)CD163^(+)macrophages and expression of interleukin-10 decreased.The correlation analysis revealed that hepatic organic acid metabolites were closely associated with macrophage-derived cytokines/chemokines.CONCLUSION The results indicated that bioenergetic alteration driven by hypoxia and mitochondrial dysfunction affects hepatic immune and metabolic remodeling,leading to advanced HBV-ACLF.These findings highlight a new therapeutic target for improving the treatment of HBV-ACLF.

Utilizing engineered extracellular vesicles as delivery vectors in the management of ischemic stroke:a special outlook on mitochondrial delivery

Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.

Research progress on the mitochondrial mechanism of age-related non-alcoholic fatty liver

Non-alcoholic fatty liver disease(NAFLD)has become the most common chronic liver disease worldwide.Reduced activity and slower metabolism in the elderly affect the balance of lipid metabolism in the liver leading to the accumulation of lipids.This affects the mitochondrial respiratory chain and the efficiency ofβ-oxidation and induces the overproduction of reactive oxygen species.In addition,the dynamic balance of the mitochondria is disrupted during the ageing process,which inhibits its phagocytic function and further aggravates liver injury,leading to a higher incidence of NAFLD in the elderly population.The present study reviewed the manifestations,role and mechanism of mitochondrial dysfunction in the progression of NAFLD in the elderly.Based on the understanding of mitochondrial dysfunction and abnormal lipid metabolism,this study discusses the treatment strategies and the potential therapeutic targets for NAFLD,including lipid accumulation,antioxidation,mitophagy and liver-protecting drugs.The purpose is to provide new ideas for the development of innovative drugs for the prevention and treatment of NAFLD.

In vivo recognition of bioactive substances of Polygonum multiflorum for protecting mitochondria against metabolic dysfunction-associated fatty liver disease

BACKGROUND Metabolic dysfunction-associated fatty liver disease(MAFLD)is a severe threat to human health.Polygonum multiflorum(PM)has been proven to remedy mitochondria and relieve MAFLD,but the main pharmacodynamic ingredients for mitigating MAFLD remain unclear.AIM To research the active ingredients of PM adjusting mitochondria to relieve highfat diet(HFD)-induced MAFLD in rats.METHODS Fat emulsion-induced L02 adipocyte model and HFD-induced MAFLD rat model were used to investigate the anti-MAFLD ability of PM and explore their action mechanisms.The adipocyte model was also applied to evaluate the activities of PM-derived constituents in liver mitochondria from HFD-fed rats(mitochondrial pharmacology).PM-derived constituents in liver mitochondria were confirmed by ultra-high-performance liquid chromatography/mass spectrometry(mitochondrial pharmacochemistry).The abilities of PM-derived monomer and monomer groups were evaluated by the adipocyte model and MAFLD mouse model,respectively.RESULTS PM repaired mitochondrial ultrastructure and prevented oxidative stress and energy production disorder of liver mitochondria to mitigate fat emulsion-induced cellular steatosis and HFD-induced MAFLD.PM-derived constituents that entered the liver mitochondria inhibited oxidative stress damage and improved energy production against cellular steatosis.Eight chemicals were found in the liver mitochondria of PM-administrated rats.The anti-steatosis ability of one monomer and the anti-MAFLD activity of the monomer group were validated.CONCLUSION PM restored mitochondrial structure and function and alleviated MAFLD,which may be associated with the remedy of oxidative stress and energy production.The identified eight chemicals may be the main bioactive ingredients in PM that adjusted mitochondria to prevent MAFLD.Thus,PM provides a new approach to prevent MAFLD-related mitochondrial dysfunction.Mitochondrial pharmacology and pharmacochemistry further showed efficient strategies for determining the bioactive ingredients of Chinese medicines that adjust mitochondria to prevent diseases.

Study on the mechanism of action of Lizhong Tang in ameliorating non-alcoholic fatty liver disease by regulating mitochondrial autophagy

Objective:To investigate the therapeutic efficacy and underlying mechanisms of LiZhong Tang in the context of non-alcoholic fatty liver disease(NAFLD).Methods:High-fat feed was used to induce NAFLD in rats,Blood and liver samples were collected to facilitate a comparative analysis of rat body mass and liver wet weight and calculate the liver index.Liver pathology was observed,while serum transaminase and blood lipid levels were measured.The protein expression levels of PINK1,Parkin,and LC-3II in rat liver were detected using Western Blot analysis.Results:Compared with the control group,the NAFLD rats exhibited a significant increase in body weight,liver wet weight,liver index,transaminase levels,and blood lipid levels.The expression levels of PINK1,Parkin,and LC3-II protein were significantly decreased(P<0.01).Following intervention with Lizhong Tang,rats in each herbal treatment group displayed a decrease in body weight,liver wet weight,liver index,se-rum transaminase,and blood lipid levels.The expression levels of PINK1,Parkin,and LC-3II rebounded(P<0.05),with the high-dose group demonstrating the most pronounced effects(P<0.01).Histopathological examination of liver tissue revealed that rats in the model group displayed disrupted hepatic lobule structure,swollen hepatocytes,disordered arrangement,and a multi-tude of varying-sized lipid vacuoles within the cytoplasm.Conversely,rats treated with different doses of the herbal remedy exhibited improvements in liver tissue pathology,with the high-dose group showing the most notable enhancement.Conclusion:Lizhong Tang can improve NAFLD disease by regulating mitochondrial autophagy.

Mitochondrial carnitine palmitoyltransferase-Ⅱ dysfunction: A possible novel mechanism for nonalcoholic fatty liver disease in hepatocarcinogenesis

Nonalcoholic fatty liver disease(NAFLD)or metabolic-associated fatty liver disease has been characterized by the lipid accumulation with injury of hepatocytes and has become one of the most common chronic liver diseases in the world.The complex mechanisms of NAFLD formation are still under identification.Carnitine palmitoyltransferase-Ⅱ(CPT-Ⅱ)on inner mitochondrial membrane(IMM)regulates long chain fatty acidβ-oxidation,and its abnormality has had more and more attention paid to it by basic and clinical research in NAFLD.The sequences of its peptide chain and DNA nucleotides have been identified,and the catalytic activity of CPT-Ⅱ is affected on its gene mutations,deficiency,enzymatic thermal instability,circulating carnitine level and so on.Recently,the CPT-Ⅱ dysfunction has been discovered in models of liver lipid accumulation.Meanwhile,the malignant transformation of hepatocyte-related CD44^(+) stem T cell activation,high levels of tumor-related biomarkers(AFP,GPC3)and abnormal activation of Wnt3a expression as a key signal molecule of the Wnt/β-catenin pathway run parallel to the alterations of hepatocyte pathology.This review focuses on some of the progress of CPT-Ⅱ inactivity on IMM with liver fatty accumulation as a possible novel pathogenesis for NAFLD in hepatocarcinogenesis.

Steatotic livers are susceptible to normothermic ischemiareperfusion injury from mitochondrial Complex-Ⅰ?dysfunction

AIM: To assess the effects of ischemic preconditioning(IPC, 10-min ischemia/10-min reperfusion) on steatotic liver mitochondrial function after normothermic ischemia-reperfusion injury(IRI).METHODS: Sixty male Sprague-Dawley rats were fed8-wk with either control chow or high-fat/high-sucrose diet inducing > 60% mixed steatosis. Three groups(n = 10/group) for each dietary state were tested:(1) the IRI group underwent 60 min partial hepatic ischemia and 4 h reperfusion;(2) the IPC group underwent IPC prior to same standard IRI; and(3) sham underwent t h e s a m e s u r g e r y w i t h o u t I R I o r I P C. H e p a t i c mitochondrial function was analyzed by oxygraphs. Mitochondrial Complex-Ⅰ, Complex-Ⅱ enzyme activity, serum alanine aminotransferase(ALT), and histological injury were measured.RESULTS: Steatotic-IRI livers had a greater increase in ALT(2476 ± 166 vs 1457 ± 103 IU/L, P < 0.01) and histological injury following IRI compared to the lean liver group. Steatotic-IRI demonstrated lower Complex-Ⅰ?activity at baseline [78.4 ± 2.5 vs 116.4 ± 6.0 nmol/(min.mg protein), P < 0.001] and following IRI [28.0 ± 6.2 vs 104.3 ± 12.6 nmol/(min.mg protein), P < 0.001]. Steatotic-IRI also demonstrated impaired Complex-Ⅰ?function post-IRI compared to the lean liver IRI group. Complex-Ⅱ activity was unaffected by hepatic steatosis or IRI. Lean liver mitochondrial function was unchanged following IRI. IPC normalized ALT and histological injury in steatotic livers but had no effect on overall steatotic liver mitochondrial function or individual mitochondrial complex enzyme activities. CONCLUSION: Warm IRI impairs steatotic liver Complex-Ⅰ?activity and function. The protective effects of IPC in steatotic livers may not be mediated through mitochondria.

Role of mitochondria in alcoholic liver disease

Alcohol abuse is the leading cause of liver related morbidity and mortality.Chronic or binge alcohol drinking causes hepatic steatosis which can develop to steatohepatitis,cirrhosis and ultimately hepatocellular carcinoma.The pathogenesis of alcoholic liver disease(ALD)is poorly characterized,however several recent studies point to a major role of mitochondria in this process.Mitochondria play a crucial role in cellular energy metabolism and in reactive species formation.Alcohol treatment causes mitochondrial DNA damage,lipid accumulation and oxidative stress.Studies in both animal models and in humans showed that alcohol administration causes changes in the mitochondrial morphology and function suggesting a role of these changes in the pathogenesis of ALD.We review recent findings on mechanisms by which alcohol negatively impacts mitochondrial biogenesis and function and we will discuss the specific intracellular pathways affected by alcohol consumption.Interestingly,recent findings indicate that a large number of mitochondrial proteins are acetylated and that mitochondrial proteins acetylation and sirtuins are modulated by alcohol.Un-derstanding the mechanisms behind alcohol mediated impaired mitochondrial biogenesis and function may help identify potential therapeutic targets for treating ALD in humans.

Protective Effects of Aqueous Extract of Eucommia ulmiodes Oliver Leaves on Liver Mitochondria

[Objective] This study aimed to investigate the protective effects of aqueous extract of Eucommia ulmiodes Oliver leaves （AEO） on liver mitochondrial injury induced by free radicals. [Method] MDA content was determined by thiobarbituric acid colorimetric method; mitochondrial swelling degree was determined by spectrophotometry; the superoxide anion radical scavenging ability was determined using reduced coenzyme I-tetrazolium-phenazine methosulfate as the superoxide anion generation system. Mice were hypodermically injected in the back and neck with D- galactose, after 50 d, the effects of AEO on the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px） and anti-hydroxyl radicals in mouse liver were determined using kits. [Result] AEO can efficiently reduce the liver injury and inhibit mitochondrial swelling induced by Fe2＋-L-Cys, which can also scavenge superoxide anion and improve the activities of antioxidant enzymes. [Conclusion] This study provided scientific basis for the development and application of AEO resources.

Nonalcoholic fatty liver disease and mitochondrial dysfunction

Nonalcoholic fatty liver disease (NAFLD) includes hepatic steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. NAFLD is the most common liver disorder in the United States and worldwide. Due to the rapid rise of the metabolic syndrome, the prevalence of NAFLD has recently dramatically increased and will continue to increase. NAFLD has also the potential to progress to hepatocellular carcinoma (HCC) or liver failure. NAFLD is strongly linked to caloric overconsumption, physical inactivity, insulin resistance and genetic factors. Although significant progress in understanding the pathogenesis of NAFLD has been achieved in years, the primary metabolic abnormalities leading to lipid accumulation within hepatocytes has remained poorly understood. Mitochondria are critical metabolic organelles serving as "cellular power plants". Accumulating evidence indicate that hepatic mitochondrial dysfunction is crucial to the pathogenesis of NAFLD. This review is focused on the significant role of mitochondria in the development of NAFLD.

Mitochondrial metabolomic profiling for elucidating the alleviating potential of Polygonatum kingianum against high-fat diet-induced nonalcoholic fatty liver disease

BACKGROUND Developing mitochondrial regulators/nutrients from natural products to remedy mitochondrial dysfunction represent attractive strategies for therapy of nonalcoholic fatty liver disease(NAFLD).Polygonatum kingianum(PK)has been traditionally used in China as a medicinal and nutritional ingredient for centuries and can alleviate high-fat diet(HFD)-induced NAFLD by promoting mitochondrial functions.To date,the underlying molecular mechanism of PK for treating mitochondrial dysfunctions and thus alleviating NAFLD remains unclear.AIM To identify the molecular mechanism behind the mitochondrial regulatory action of PK against HFD-induced NAFLD in rats.METHODS NAFLD model was induced in rats with HFD.The rats were intragastrically administered PK(4 g/kg per day)for 14 wk.Metabolites in hepatic mitochondrial samples were profiled through ultra-high performance liquid chromatography/mass spectrometry followed by multivariate statistical analysis to find the potential biomarkers and metabolic pathways.RESULTS PK significantly restored the metabolites’levels in the mitochondrial samples.Ten potential biomarkers were identified in the analyzed samples.These biomarkers are involved in riboflavin metabolism.CONCLUSION PK can alleviate HFD-induced NAFLD by regulating the riboflavin metabolism and further improving the mitochondrial functions.Thus,PK is a promising mitochondrial regulator/nutrient for alleviating NAFLD-associated diseases.

Anti-lipid peroxidation and protection of liver mitochondria against injuries by picroside Ⅱ

AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachloride (CCl4: 0.1 mL/10 g, ip), D-galactasamine (D-GaIN: 500 mg/kg, ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated. RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by the administration of CCl4, D-GaIN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dose dependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱ inhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism. CONCLUSION: Picroside II can evidently relieve hepatocyte injuries induced by CCI4, D-GaIN and AP, help scavenge free radicals, protect normal constructions of mitochondria membrane and enhance the activity of ATPase in mitochondria, thereby modulating the balance of liver energy metabolism, which might be part of the mechanisms of hepatoprotective effects of picroside Ⅱ.

Novel interactions of mitochondria and reactive oxygen/nitrogen species in alcohol mediated liver disease

Mitochondrial dysfunction is known to be a contributing factor to a number of diseases including chronic alcohol induced liver injury. While there is a detailed understanding of the metabolic pathways and proteins of the liver mitochondrion, little is known regarding how changes in the mitochondrial proteome may contribute to the development of hepatic pathologies. Emerging evidence indicates that reactive oxygen and nitrogen species disrupt mitochondrial function through post-translational modifications to the mitochondrial proteome. Indeed, various new affinity labeling reagents are available to test the hypothesis that post-translational modification of proteins by reactive species contributes to mitochondrial dysfunction and alcoholic fatty liver disease. Specialized proteomic techniques are also now available, which allow for identification of defects in the assembly of multi-protein complexes in mitochondria and the resolution of the highly hydrophobic proteins of the inner membrane. In this review knowledge gained from the study of changes to the mitochondrial proteome in alcoholic hepatotoxicity will be described and placed into a mechanistic framework to increase understanding of the role of mitochondrial dysfunction in liver disease.

Proteomic analysis of glutathione S-transferase isoforms in mouse liver mitochondria

AIM:To survey glutathione(GSH) S-transferase(GST) isoforms in mitochondria and to reveal the isoforms' biological significance in diabetic mice.METHODS:The presence of GSTs in mouse liver mitochondria was systematically screened by two proteomic approaches,namely,GSH affinity chromatography/two dimensional electrophoresis(2DE/MALDI TOF/TOF MS) and SDS-PAGE/LC ESI MS/MS.The proteomic results were further confirmed by Western blotting using monoclonal antibodies against GSTs.To evaluate the liver mitochondrial GSTs quantitatively,calibration curves were generated by the loading amounts of individual recombinant GST protein vs the relative intensities elicited from the Western blotting.An extensive comparison of the liver mitochondrial GSTs was conducted between normal and db/db diabetic mice.Student's t test was adopted for the estimation of regression and significant difference.RESULTS:Using GSH affinity/2DE/MALDI TOF/TOF MS,three GSTs,namely,alpha3,mu1 and pi1,were identified;whereas five GSTs,alpha3,mu1,pi1,kappa1 and zeta1,were detected in mouse liver mitochondria using SDS-PAGE/LC ESI MS/MS,of these GSTs,GST kappa1 was reported as a specific mitochondrial GST.The R 2 values of regression ranged between values of about 0.86 and 0.98,which were acceptable for the quantification.Based on the measurement of the GST abundances in liver mitochondria of normal and diabetic mice,the four GSTs,alpha3,kappa1,mu1 and zeta1,were found to be almost comparable between the two sets of animals,whereas,lower GST pi1 was detected in the diabetic mice compared with normal ones,the signal of Western blotting in control and db/db diabetic mice liver mitochondria is 134.61 ± 53.84 vs 99.74 ± 46.2,with P < 0.05.CONCLUSION:Our results indicate that GSTs exist widely in mitochondria and its abundances of mitochondrial GSTs might be tissue-dependent and disease-related.

Protective Effect of Pueraria lobota Extracts on Mitochondria Damage of Liver

[Objective] This study aimed to investigate the protective effect of Pueraria lobota extracts on mitochondria damage of liver. [Method] The liver mitochondria injury was induced by Vc-Fe2＋ , and the influences of Pueraria lobota extracts on mitochondria ATPase activity, mitochondria swelling and protein carbonyl content were measured. In addition, the lipid peroxidation in liver mitochondria was induced by H2O2-Fe2＋ to analyze the influence of Pueraria lobota extracts on MDA content. Futhermore, NBT method was used to evaluate the inhibitory function of Pueraria lobota extracts on the superoxide anion. [Result] The results showed that Pueraria lobota extracts could significantly inhibit mitochondria oxidative damage,prevent mitochondria swelling and ATPase activity reduction,decrease protein carbonyl level,and effectively scavenge superoxide anion produced by mitochondria, indicating that Pueraria lobota extracts can protect rat liver mitochondria from oxidative damage. [Conclusion] This study provided theoretical basis for investigating the pharmacological functions of Pueraria lobota.

Elafibranor:A promising treatment for alcoholic liver disease,metabolic-associated fatty liver disease,and cholestatic liver disease

Liver diseases pose a significant threat to human health.Although effective therapeutic agents exist for some liver diseases,there remains a critical need for advancements in research to address the gaps in treatment options and improve patient outcomes.This article reviews the assessment of Elafibranor's effects on liver fibrosis and intestinal barrier function in a mouse model of alcoholic liver disease(ALD),as reported by Koizumi et al in the World Journal of Gastroenterology.We summarize the impact and mechanisms of Elafibranor on ALD,metabolic-associated fatty liver disease,and cholestatic liver disease based on current research.We also explore its potential as a dual agonist of PPARα/δ,which is undergoing Phase III clinical trials for metabolic-associated steatohepatitis.Our goal is to stimulate further investigation into Elafibranor's use for preventing and treating these liver diseases and to provide insights for its clinical application.

Experimental research on phospholipids variation of halothane on liver mitochondria

AIM To study the pathogenesis of hepatotoxicity of halothane. METHODS The effect of different concentration of halothane and sevoflurane on mitochondrial membrane phospholipids composition of rat liver were analyzed using high performance liquid chromatography (HPLC) technology. RESULTS Halothane at low concentration could degrade mitochondrial membrane major phospholipids and increase lysophosphatidylcholine. CONCLUSION The pathogenesis of halothane hepatotoxicity was the phospholipids variation on liver mitochondria.

Liver fat deposition and mitochondrial dysfunction in morbid obesity:An approach combining metabolomics with liver imaging and histology

AIM: To explore the usefulness of magnetic resonance imaging(MRI) and spectroscopy(MRS) for assessment of non-alcoholic fat liver disease(NAFLD) as compared with liver histological and metabolomics findings. METHODS: Patients undergoing bariatric surgery following procedures involved in laparoscopic sleeve gastrectomy were recruited as a model of obesityinduced NAFLD in an observational, prospective, singlesite, cross-sectional study with a pre-set duration of 1 year. Relevant data were obtained prospectively and surrogates for inflammation, oxidative stress and lipid and glucose metabolism were obtained through standard laboratory measurements. To provide reliable data from MRI and MRS, novel procedures were designed to limit sampling variability and other sources of error using a 1.5T Signa HDx scanner and protocols acquired from the 3D or 2D Fat SAT FIESTA prescription manager. We used our previously described 1H NMRbased metabolomics assays. Data were obtained immediately before surgery and after a 12-mo period including histology of the liver and measurement of metabolites. Values from 1H NMR spectra obtained after surgery were omitted due to technical limitations.RESULTS: MRI data showed excellent correlation with the concentration of liver triglycerides, other hepatic lipid components and the histological assessment, w h i c h e xc l u d e d t h e p r e s e n c e o f n o n-a l c o h o l i c steatohepatitis(NASH). MRI was sufficient to follow up NAFLD in obese patients undergoing bariatric surgery and data suggest usefulness in other clinical situations. The information provided by MRS replicated that obtained by MRI using the-CH3 peak(0.9 ppm), the-CH2- peak(1.3 ppm, mostly triglyceride) and the-CH=CH- peak(2.2 ppm). No patient depicted NASH. After surgery all patients significantly decreased their body weight and steatosis was virtually absent even in patients with previous severe disease. Improvement was also observed in the serum concentrations of selected variables. The most relevant findings using metabolomics indicate increased levels of triglyceride and monounsaturated fatty acids in severe steatosis but those results were accompanied by a significant depletion of diglycerides, polyunsaturated fatty acids, glucose-6-phosphate and the ATP/AMP ratio. Combined data indicated the coordinated action on mitochondrial fat oxidation and glucose transport activity and may support the consideration of NAFLD as a likely mitochondrial disease. This concept may helpto explain the dissociation between excess lipid storage in adipose tissue and NAFLD and may direct the search for plasma biomarkers and novel therapeutic strategies. A limitation of our study is that data were obtained in a relatively low number of patients.CONCLUSION: MRI is sufficient to stage NAFLD in obese patients and to assess the improvement after bariatric surgery. Other data were superfluous for this purpose.

Oxidative stress, cardiolipin and mitochondrial dysfunction in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease(NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, ranging from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. Obesity, hyperglycemia, type 2 diabetes and hypertriglyceridemia are the most important risk factors. The pathogenesis of NAFLD and its progression to fibrosis and chronic liver disease is still unknown. Accumulating evidence indicates that mitochondrial dysfunction plays a key role in the physiopathology of NAFLD, although the mechanisms underlying this dysfunction are still unclear. Oxidative stress is considered an important factor in producing lethal hepatocyte injury associated with NAFLD. Mitochondrial respiratory chain is the main subcellular source of reactive oxygen species(ROS), which may damage mitochondrial proteins, lipids and mitochondrial DNA. Cardiolipin, a phospholipid located at the level of the inner mitochondrial membrane, plays an important role in several reactions and processes involved in mitochondrial bioenergetics as well as in mitochondrial dependent steps of apoptosis. This phospholipid is particularly susceptible to ROS attack. Cardiolipin peroxidation has been associated with mitochondrial dysfunction in multiple tissues in several physiopathological conditions, including NAFLD. In this review, we focus on the potential roles played by oxidative stress and cardiolipin alterations in mitochondrial dysfunction associated with NAFLD.