线粒体功能障碍和氧化应激在脂肪肝中的作用机制

目前各种病因引起的肝脏脂肪变性甚至发展为脂肪性肝炎或脂肪性肝硬化成为当今严重的公共卫生及医疗问题。氧化应激、NO信号通路的中断和线粒体功能障碍等被认为是加速脂肪变性和启动脂肪肝和纤维化进程的关键机制。线粒体损伤和氧化应激之间相互作用的复杂机制,也使得临床治疗脂肪性肝炎效果不佳。因此找到一种多基因、多靶点安全有效阻断氧化应激和线粒体损伤的分子靶向药物和治疗方案成为了学术界的难题。     

干细胞治疗神经退行性疾病的前景与问题

背景：虽然各种神经退行性疾病的人群发病率居高不下且有上升趋势,但至今仍无有效治疗方法,因此,寻求有效的治疗神经退行性疾病的途径是科学界面临的挑战.目的：文章分析和综述了对干细胞治疗神经退行性疾病的近年研究进展及热点问题.方法：文章对干细胞移植治疗神经退行性疾病,如阿尔茨海默病、帕金森病、脑卒中、亨廷顿病、视网膜色素变性疾病、肌萎缩性侧索硬化症、癫痫等疾病的基础与临床研究进展进行概述,探讨干细胞治疗神经退行性疾病的可行性、优势及问题.结果与结论：干细胞治疗神经退行性疾病大部分研究还是集中在实验动物模型阶段,还没有支持干细胞临床治疗的有效证据,其安全性和有效性还没有确切临床保证和标准,临床治疗效果及不良反应都有待大宗及长期临床试验研究进一步验证.     

The path to biomarker-based diagnostic criteria for the spectrum of neurodegenerative diseases

ABSTRACT

Introduction: The postmortem examination still represents the reference standard for detecting the pathological nature of chronic neurodegenerative diseases (NDD). This approach displays intrinsic conceptual limitations since NDD represent a dynamic spectrum of partially overlapping phenotypes, shared pathomechanistic alterations that often give rise to mixed pathologies.

Areas covered: We scrutinized the international clinical diagnostic criteria of NDD and the literature to provide a roadmap toward a biomarker-based classification of the NDD spectrum. A few pathophysiological biomarkers have been established for NDD. These are time-consuming, invasive, and not suitable for preclinical detection. Candidate screening biomarkers are gaining momentum. Blood neurofilament light-chain represents a robust first-line tool to detect neurodegeneration tout court and serum progranulin helps detect genetic frontotemporal dementia. Ultrasensitive assays and retinal scans may identify Aβ pathology early, in blood and the eye, respectively. Ultrasound also represents a minimally invasive option to investigate the substantia nigra. Protein misfolding amplification assays may accurately detect α-synuclein in biofluids.

Expert opinion: Data-driven strategies using quantitative rather than categorical variables may be more reliable for quantification of contributions from pathophysiological mechanisms and their spatial-temporal evolution. A systems biology approach is suitable to untangle the dynamics triggering loss of proteostasis, driving neurodegeneration and clinical evolution.     

Sepsis-induced mitochondrial dysfunction: A narrative review

Sepsis represents a deranged and exaggerated systemic inflammatory response to infection and is associated with vascular and metabolic abnormalities that trigger systemic organic dysfunction. Mitochondrial function has been shown to be severely impaired during the early phase of critical illness, with a reduction in biogenesis, increased generation of reactive oxygen species and a decrease in adenosine triphosphate synthesis of up to 50%. Mitochondrial dysfunction can be assessed using mitochondrial DNA concentration and respirometry assays, particularly in peripheral mononuclear cells. Isolation of monocytes and lymphocytes seems to be the most promising strategy for measuring mitochondrial activity in clinical settings because of the ease of collection, sample processing, and clinical relevance of the association between metabolic alterations and deficient immune responses in mononuclear cells. Studies have reported alterations in these variables in patients with sepsis compared with healthy controls and non-septic patients. However, few studies have explored the association between mitochondrial dysfunction in immune mononuclear cells and unfavorable clinical outcomes. An improvement in mitochondrial parameters in sepsis could theoretically serve as a biomarker of clinical recovery and response to oxygen and vasopressor therapies as well as reveal unexplored pathophysiological mechanistic targets. These features highlight the need for further studies on mitochondrial metabolism in immune cells as a feasible tool to evaluate patients in intensive care settings. The evaluation of mitochondrial metabolism is a promising tool for the evaluation and management of critically ill patients, especially those with sepsis. In this article, we explore the pathophysiological aspects, main methods of measurement, and the main studies in this field.     

Neuroprotective effects of Caralluma tuberculata on ameliorating cognitive impairment in a d-galactose-induced mouse model

Cognitive deficiency and oxidative stress have been well documented in aging disorders including Alzheimer’s disease. The aim of this study was to investigate the therapeutic efficacy of Caralluma tuberculata methanolic extract (CTME) on cognitive impairment in mice induced with d-galactose. In this study we assessed the therapeutic efficacy of CTME on cognitive impairment in mice induced with d-galactose by conduction of behavioral and cognitive performance tests. In order to explore the possible role of CTME against d-galactose-induced oxidative damages, various biochemical indicators were assessed. Chronic administration of d-galactose (150 mg/kg d, s.c.) for 7 weeks significantly impaired cognitive performance (in step-through passive, active avoidance test, Hole-Board test, Novel object recognition task and Morris water maze) and oxidative defense as compared to the control group. The results revealed that CTME treatment for two weeks (100, 200 and 300 mg/kg p.o) significantly ameliorated cognitive performance and oxidative defense. All groups of CTME enhanced the learning and memory ability in step-through passive, active avoidance test, Hole-Board test Novel object recognition task and Morris water maze. Furthermore, high and middle level of CTME (300 and 200 mg/kg p.o) significantly increased Total antioxidative capacity (T-AOC), Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activity, neprilysin (NEP), and β-site AβPP cleaving enzyme 1 (BACE1) expression while Nitric Oxide (NO), Nitric Oxide Synthase (NOS) activity and Malondialdehyde (MDA) concentration, and the level of Aβ1-42 and presenilin 1 (PS1) were decreased. The present study showed that CTME have a significant relieving effect on learning, memory and spontaneous activities in d-galactose-induced mice model, and ameliorates cognitive impairment and biochemical dysfunction in mice.     

The role of mitochondrial dysfunction in cardiovascular disease: a brief review

Cardiovascular disease (CVD) is a leading cause of mortality worldwide. Proper mitochondrial function is necessary in tissues and organs that are of high energy demand, including the heart. Mitochondria are very sensitive to nutrient and oxygen supply and undergo metabolic adaptation to the changing environment. In CVD, such an adaptation is impaired, which, in turn, leads to a progressive decline of the mitochondrial function associated with abnormalities in the respiratory chain and ATP synthesis, increased oxidative stress, and loss of the structural integrity of mitochondria. Uncoupling of the electron transport chain in dysfunctional mitochondria results in enhanced production of reactive oxygen species, depletion of cell ATP pool, extensive cell damage, and apoptosis of cardiomyocytes. Mitophagy is a process, during which cells clear themselves from dysfunctional and damaged mitochondria using autophagic mechanism. Deregulation of this process in the failing heart, accumulation of dysfunctional mitochondria makes the situation even more adverse. In cardiac pathology, aberrations of the activity of the respiratory chain and ATP production may be considered as a core of mitochondrial dysfunction. Indeed, therapeutic restoration of these key functional properties can be considered as a primary goal for improvement of mitochondrial dysfunction in CVD.

• Key messages

• Mitochondrial dysfunction plays a crucial role in cardiovascular disease pathogenesis.

• Cardiovascular disease is associated with altered mithochondrial biogenesis and clearance.

• In cardiovascular disease, impaired mitochondrial function results in decreased ATP production and enhanced ROS formation.

     

氧化应激及凋亡与重症急性胰腺炎肠屏障功能障碍

目的 通过动物实验,观察重症急性胰腺炎(severe acute pancreatitis,SAP)肠道屏障功能变化,探讨炎症因子释放、肠黏膜氧化应激及凋亡在肠屏障功能障碍中的作用.方法 上海交通大学附属第一人民医院动物实验中心内,24只BALB/c小鼠,随机数字法分为2组,SAP组:以雨蛙素联合脂多糖腹腔注射法诱导,先腹腔内注射雨蛙素50 μg/kg,连续6次,每次间隔1h,在末次雨蛙素注射同时,腹腔内注射脂多糖10 mg/kg(LPS E.Coli);对照(假手术)组:每小时一次腹腔注射生理盐水2 ml,共6次.两组动物分2批(每批6只/组)分别于建模后4h及8h,麻醉后打开腹腔取血及标本.观察小鼠胰腺及肠道病理变化并予评分,测定小鼠血二胺氧化酶(diamine oxidase,DAO)、淀粉酶、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)含量,测定肠黏膜丙二醛( malondialdehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)、还原型谷胱甘肽( glutathione,GSH)含量及黄嘌呤氧化酶(xanthine oxidase,XO)活力,检测小鼠肠黏膜细胞caspase-3酶活性,脱氧核糖核苷酸末端转移酶介导的缺口末端标记(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling,TUNEL)法检测小鼠肠黏膜凋亡细胞并计算凋亡指数.以PASW 18.0软件对数据进行方差分析及t检验,明确上述检测指标在两组小鼠间差异是否有统计学意义,从而明确重症急性胰腺炎肠道屏障功能障碍的机制.结果 建模后4h及8h,SAP组小鼠胰腺出血、坏死、炎症细胞浸润较对照组严重,胰腺病理评分与对照组比较差异具有统计学意义(P＜0.01),血淀粉酶含量与对照组比较差异具有统计学意义(P＜0.05);肠组织病理评分及血DAO质量浓度与对照组比较差异具有统计学意义(P＜0.01);血TNF-α质量浓度与对照组比较差异具有统计学意义(P＜0.01);肠黏膜MDA含量及XO活力与对照组比较差异具有统计学意义(P＜0.01),肠黏膜SOD含量与对照组比较差异具有统计学意义(P＜0.01)、GSH含量与对照组比较差异具有统计学意义(P＜0.05);肠黏膜细胞caspase-3酶活性及凋亡指数与对照组比较差异具有统计学意义(P＜0.01).结论 重症急性胰腺炎发病后,TNF-α等炎症因子瀑布样释放,导致肠黏膜缺血-再灌注损伤,形成严重的氧化应激反应,进一步激活caspase-3通路,导致肠黏膜细胞凋亡增加,是肠黏膜屏障功能受损的重要机制.     

Oxidative stress and antioxidant capacity in patients with inflammatory bowel disease

OBJECTIVES: In this study we aimed to determine the levels of Glutathione peroxidase (GSH-Px) and Malondialdehyde (MDA) in patients with inflammatory bowel disease (IBD) to investigate their contribution to tissue injury in inflammatory bowel disease. DESIGN AND METHODS: Forty-seven GSH-Px patients (35 with ulcerative colitis and 12 with Crohn's disease) and 30 healthy controls were included in the study. Their plasma and MDA levels were compared using nonparametric statistical methods. RESULTS: Plasma GSH-Px levels of the patients group were significantly higher than the control group (p < 0.001). There was no significant difference between patients and controls in view of plasma levels of MDA. CONCLUSIONS: High levels of GSH-Px, which is response against oxidative stress, indicates the increase of free radicals in IBD, while normal plasma MDA levels suggest the clearance of free radicals without leading to lipid peroxidation. Our result reveals that there is an existing antioxidant capacity despite oxidative stress in patients with IBD.     

隐丹参酮与多奈哌齐合用对Aβ诱导大鼠皮层神经元损伤的保护作用

目的：观察隐丹参酮与多奈哌齐合用对Aβ42诱导大鼠皮层神经元凋亡的保护作用及其可能机制。方法通过Aβ42诱导体外培养的大鼠皮层神经元,建立阿尔茨海默病（Alzheimer＆#39;s disease,AD）细胞模型,MTT比色法检测细胞存活率,流式细胞仪检测细胞凋亡率,分光光度法测定SOD活性、MDA含量及LDH漏出量。结果成功建立大鼠皮层神经元AD细胞模型,经检测模型组MDA含量及LDH漏出量显著高于空白对照组且SOD活力明显低于空白对照组;隐丹参酮组、隐丹参酮加多奈哌齐组MDA含量及LDH漏出量均低于模型组,且SOD活力明显高于模型组,差异均有统计学意义（P〈0.05）;隐丹参酮与多奈哌齐合用在抑制神经元凋亡,降低MDA含量、LDH漏出量及提高SOD活性方面的效果显著强于隐丹参酮与多奈哌齐单用。结论隐丹参酮与多奈哌齐合用对Aβ损伤细胞有保护作用,其机制可能与协同抗氧化能力有关。     

Safflower yellow reduces lipid peroxidation,neuropathology, tau phosphorylation and ameliorates amyloid β-induced impairment of learning and memory in rats

Insoluble plaques of amyloid β proteins (Aβ) and neurofibrillary tangles of hyperphosphorylated tau are key markers for Alzheimer’s disease (AD). Safflower yellow (SY) is one of traditional Chinese medicine extracted from safflower, which is suggested to have therapeutic potential for neurodegenerative disorders. However, whether SY can ameliorate impairment of learning and memory in AD model, and its causal mechanism are still unclear. Here, we applied different doses of SY intragastrically to Wistar rats injected with amyloid β (1–42) for 1 month. By the Morris water maze test, we found that treatment of SY significantly attenuated amyloid β (1–42)-induced impairment of memory in rats. Mechanistically, SY treatment increased the level of superoxidedismutase (SOD) and Glutathione peroxidase (GSH-Px), and decreased the level of malondialdehyde (MDA) and acetylcholinesterase (T-CHE) in brain tissues of AD rats. Pathological analysis also showed that SY treatment inhibited the morphological alteration of neurons and tau hyperphosphorylation induced by amyloid β (1–42)-injection in the cortex and hippocampus. Moreover, SY treatment inhibited CDK-5 and GSK-3 signaling pathways, which are upregulated in AD rats. Our data indicate that safflower yellow can serve as a therapeutic candidate for Alzheimer’s disease.     

A mitochondrial superoxide theory for oxidative stress diseases and aging

Fridovich identified CuZnSOD in 1969 and manganese superoxide dismutase (MnSOD) in 1973, and proposed ”the Superoxide Theory,” which postulates that superoxide (O₂^•−) is the origin of most reactive oxygen species (ROS) and that it undergoes a chain reaction in a cell, playing a central role in the ROS producing system. Increased oxidative stress on an organism causes damage to cells, the smallest constituent unit of an organism, which can lead to the onset of a variety of chronic diseases, such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis and other neurological diseases caused by abnormalities in biological defenses or increased intracellular reactive oxygen levels. Oxidative stress also plays a role in aging. Antioxidant systems, including non-enzyme low-molecular-weight antioxidants (such as, vitamins A, C and E, polyphenols, glutathione, and coenzyme Q₁₀) and antioxidant enzymes, fight against oxidants in cells. Superoxide is considered to be a major factor in oxidant toxicity, and mitochondrial MnSOD enzymes constitute an essential defense against superoxide. Mitochondria are the major source of superoxide. The reaction of superoxide generated from mitochondria with nitric oxide is faster than SOD catalyzed reaction, and produces peroxynitrite. Thus, based on research conducted after Fridovich’s seminal studies, we now propose a modified superoxide theory; i.e., superoxide is the origin of reactive oxygen and nitrogen species (RONS) and, as such, causes various redox related diseases and aging.     

Development of lipophilic cations as therapies for disorders due to mitochondrial dysfunction

Mitochondrial dysfunction causes or exacerbates a number of diseases. These include genetic disorders such as Friedreich’s ataxia where the primary lesion is a defect in a nuclear gene and those diseases caused by mutations to mitochondrial DNA. Mitochondrial damage also contributes to neurodegenerative diseases, diabetes and ischaemia-reperfusion injury. Drug therapies to prevent or alleviate mitochondrial dysfunction use redox active compounds, anti-oxidants or mitochondrial co-factors, however, their effectiveness is limited. A promising approach to increase the selectivity and potency of these compounds is to modify them so that they concentrate within mitochondria. This can be done by incorporating a lipophilic cation which causes the molecules to concentrate several hundred-fold in mitochondria, driven by the membrane potential across the inner membrane. As lipophilic cations cross biological membranes easily, they can be delivered to mitochondria of the heart, brain and skeletal muscle, the organs most affected by mitochondrial damage. Mitochondria-targeted lipophilic cations may lead to improved therapies for diseases involving mitochondrial dysfunction.     

体外膈肌起搏对机械通气兔膈肌功能障碍的保护作用及机制研究

目的 探讨体外膈肌起搏对机械通气兔膈肌功能障碍的保护作用及其机制.方法 85只成年新西兰兔按随机数字表法分为空白对照组(blank control group,BC)、自主呼吸组(spontaneous breathing group,SB)、容量控制通气组(volume control ventilation gro...     

微炎症及氧化应激对慢性肾脏病患者肾功能的影响

目的：研究非透析不同分期慢性肾脏病（chronickidneydisease,CKD）患者血清中微炎症及氧化应激相关指标的变化及对肾功能的影响。方法：对CKD第1～5期92例患者测定血清超敏C反应蛋白（hs—CRP）、脂蛋白a[LP（a）]、超氧化物歧化酶（SOD）水平,并比较它们在不同分期患者中的水平。结果：随cKD分期的增加,患者血清hs—CRP、LP（a）水平逐渐升高,血清s0D活性逐渐下降;血清hs—CRP、LP（a）水平与s0D水平呈负相关,血清s0D活性与肾小球滤过率（estimatedglomeru1arfiltrationrate,eGFR）呈正相关。结论：CKD患者均存在一定程度的微炎症、氧化应激增强,而且随着肾功能损害加重,其微炎症及氧化应激状态增强。CKD非透析患者微炎症与氧化应激反应相互促进,均参与并促进肾功能的减退。     

The influence of common free radicals and antioxidants on development of Alzheimer’s Disease

Alzheimer’s Disease (AD) is one of the most important neurodegenerative disorders in the 21st century for the continually aging population. Despite an increasing number of patients, there are only few drugs to treat the disease. Numerous studies have shown several causes of the disorder, one of the most important being oxidative stress. Oxidative stress is connected with a disturbance between the levels of free radicals and antioxidants in organisms. Solutions to this problem are antioxidants, which counteract the negative impact of the reactive molecules. Unfortunately, the currently available drugs against AD do not exhibit activity toward these structures. Due to the fact that natural substances are extremely significant in new drug development, numerous studies are focused on substances which exhibit a few activities including antioxidants and other anti-AD behaviors. This review article presents the most important studies connected with the influence of free radicals on development of AD and antioxidants as potential drugs toward AD.     

Role of neurotoxicants in the pathogenesis of Alzheimer’s disease: a mechanistic insight

Alzheimer’s disease (AD) is the most conspicuous chronic neurodegenerative syndrome, which has become a significant challenge for the global healthcare system. Multiple studies have corroborated a clear association of neurotoxicants with AD pathogenicity, such as Amyloid beta (Aβ) proteins and neurofibrillary tangles (NFTs), signalling pathway modifications, cellular stress, cognitive dysfunctions, neuronal apoptosis, neuroinflammation, epigenetic modification, and so on. This review, therefore, aimed to address several essential mechanisms and signalling cascades, including Wnt (wingless and int.) signalling pathway, autophagy, mammalian target of rapamycin (mTOR), protein kinase C (PKC) signalling cascades, cellular redox status, energy metabolism, glutamatergic neurotransmissions, immune cell stimulations (e.g. microglia, astrocytes) as well as an amyloid precursor protein (APP), presenilin-1 (PSEN1), presenilin-2 (PSEN2) and other AD-related gene expressions that have been pretentious and modulated by the various neurotoxicants. This review concluded that neurotoxicants play a momentous role in developing AD through modulating various signalling cascades. Nevertheless, comprehension of this risk agent-induced neurotoxicity is far too little. More in-depth epidemiological and systematic investigations are needed to understand the potential mechanisms better to address these neurotoxicants and improve approaches to their risk exposure that aid in AD pathogenesis.

Key messages

• Inevitable cascade mechanisms of how Alzheimer’s Disease-related (AD-related) gene expressions are modulated by neurotoxicants have been discussed.
• Involvement of the neurotoxicants-induced pathways caused an extended risk of AD is explicited.
• Integration of cell culture, animals and population-based analysis on the clinical severity of AD is addressed.

     

Oxidative stress as a novel target in pediatric sepsis management

Sepsis with secondary multisystem organ dysfunction syndrome is the leading cause of death in the pediatric intensive care unit. Increased reactive oxygen species may influence circulating and endothelial cells, contributing to inflammatory tissue injury and explaining the tissue hypoxia paradigm based on microvascular dysfunction. An impaired mitochondrial cellular oxygen utilization, rather than inadequate oxygen delivery, was claimed to play a more important role in the development of multisystem organ dysfunction syndrome. Anyway, it seems plausible that reactive oxygen species can mediate the pathophysiologic processes occurring in sepsis. However, the consensus guidelines for the management of patients with these conditions do not include the enhancement of antioxidant potential. Therefore, further investigation is needed to support interventions aimed to attenuate the severity of the systemic compromise by abrogating the mechanism of oxidative damage. Antioxidant supplementation currently in use lacks a mechanistic support. Specific pharmacologic targets, such as mitochondria or Nicotinamide Adenine Dinucleotide Phospate-Oxidase (NADPH) oxidase system, need to be explored. Furthermore, the early recognition of oxidative damage in these seriously ill patients and the usefulness of oxidative stress biomarkers to define a cut point for more successful therapeutic antioxidant interventions to be instituted would offer a new strategy to improve the outcome of critically ill children.     

Beliefs and Attitudes of Graduate Gerontology Students about Medical Marijuana Use for Alzheimer’s and Parkinson’s Disease

AimsThe aims of the current study were as follows: 1) to assess gerontology graduate students’ beliefs about medical marijuana’s (MMJ) effectiveness for two common age-related conditions - Alzheimer’s (AD) and Parkinson’s disease (PD); 2) to assess students’ beliefs and attitudes toward MMJ; 3) to explore associations linking background characteristics, MMJ-related attitudes and beliefs, and beliefs about the MMJ effectiveness for AD and PD.MethodA sample of 104 (84 women and 20 men) gerontology graduate students voluntarily participated in the anonymous online survey.ResultsThe vast majority (95%) of the participants indicated they had no formal education about MMJ and reported being unprepared to answer clients’ MMJ-related questions (84.6%). Most of the participants believed that MMJ is effective for use with AD (70.2%) and PD (80.8%) patients. Participants reported favorable beliefs about MMJ benefits, concerns about risks, the need for training, and positive attitudes toward recreational marijuana use legalization. Prior marijuana use (e.g., self-use, friends or family) was found to be associated with more positive beliefs about MMJ benefits, risks, and its legalization for recreational purposes. Prior marijuana use was the only factor associated with the belief that MMJ is an effective therapy for use with AD or PD patients.ConclusionsThe study findings show the need for students’ MMJ education in order to provide future gerontology service providers with the necessary knowledge and ability to address clients’ questions about MMJ use. Efforts to develop curricula and training programs need to be promoted.     

Delusional misidentification in Parkinson’s disease: report of two cases and a review

Syndromes of delusional misidentification consist of disordered familiarity and have been reported in diverse diagnoses, including Parkinson’s disease. Although the most common delusional misidentification is Capgras syndrome, in which the sufferer believes a familiar person has been replaced by an identical imposter, other forms have been also described. The pathogenesis of delusions of misidentification appears to require dysfunction of or connection to a left cerebral cortical area involved in recognition of familiarity, and also right frontal cortex serving belief evaluation. Two cases of Parkinson’s disease with an unusual delusional misidentification, intermetamorphosis, are presented, along with their improvement with pimavanserin, a novel atypical antipsychotic medication.