线粒体功能障碍与脓毒症急性肾损伤的研究进展

脓毒症是急性肾损伤(acute kidney injury,AKI)发生发展的主要原因之一,其发病率和病死率一直居高不下。近年来的研究表明,线粒体功能障碍在脓毒症急性肾损伤(septic acute kidney injury,SAKI)中扮演着重要角色,并有望成为未来的治疗靶点。本文主要针对线粒体氧化应激、线粒体动力学、线粒体自噬、线粒体生物合成、线粒体DNA损伤和免疫应答等方向的研究进展综述,以利于继续寻找靶向线粒体的防护策略与相关生物标志物,帮助临床早期诊断和治疗SAKI,为改善患者生存与预后提供新的思路。     

脓毒症急性肾损伤氧化应激损伤机制的研究进展

脓毒症是急性肾损伤的常见病因,其发病机制非常复杂,其中包括脓毒症患者机体发生的氧化应激反应使肾小管上皮细胞内的线粒体受到损害,从而导致细胞死亡;同时,线粒体又是制造活性氧的主要细胞器,线粒体功能障碍使肾脏损伤进一步加重,形成恶性循环。线粒体受活性氧的影响比其他细胞器更大。抗氧化应激可作为脓毒症急性肾损伤潜在的治疗目标。本文围绕线粒体氧化应激,对氧化应激在脓毒症急性肾损伤发病中的作用机制以及脓毒症急性肾损伤抗氧化应激治疗策略进行了综述。     

脓毒症的急性肾损伤

脓毒症是危重病患者的常见病因或并发症，也是大家熟知的引起急性肾损伤（AKI）和多脏器功能障碍综合征（MODS）的常见危险因素。急性肾功能衰竭（ARF）发生率在一般脓毒症患者约为19％；在重度脓毒症约为23％；在血培养阳性的脓毒症休克者可高达51％。ARF并发脓毒症的病死率高达70％，明显高于无并发脓毒症的45％。因此，研究并了解AKI和脓毒症的相互关系和作用机制，将有助于降低脓毒症时AKI的高发病率以及相关的高器官衰竭率和病死率。     

吸入高浓度氢气对脓毒症小鼠急性肾损伤及线粒体动力学的影响

目的评价吸入高浓度氢气对脓毒症小鼠急性肾损伤(AKI)及线粒体动力学的影响。方法雄性C57BL/6J小鼠128只, 6～8周龄, 体质量20～25 g, 采用随机数字表法分为4组(n=32):假手术组(Sham组)、假手术+氢气组(Sham+H组)、脓毒症AKI组(S-AKI)和脓毒症AKI+氢气组(S-AKI+H组)。采用盲肠结扎穿孔法建立小鼠脓毒症模型。Sham+H组和S-AKI+H组于假手术或造模后1和6 h时分别吸入67%氢气+33%氧气1 h。取20只小鼠观察造模后7 d的生存情况。于造模后24 h时, 取血标本, 采用比色法测定血清BUN和Cr浓度;取肾组织, HE染色后进行肾小管损伤评分, 采用ELISA法测定肾组织TNF-α、IL-1β和高迁移率族蛋白B1(HMGB1)的含量, 采用分光光度法测定SOD和过氧化氢酶(CAT)的活性, 采用Western blot法测定动力相关蛋白1(Drp1)和线粒体融合蛋白2(Mfn2)的表达水平。结果与Sham组比较, S-AKI组生存率降低, 血清BUN和Cr浓度、肾小管损伤评分、肾组织TNF-α、IL-1β和HMGB1含量升高,...     

线粒体质量控制系统在脓毒症相关性脑病中作用的研究进展

脓毒症相关性脑病是脓毒症最常见的中枢神经系统并发症,可导致患者远期神经功能异常、预后不良,目前尚无有效的防治策略。线粒体功能障碍是脓毒症相关性脑病的关键病理机制之一,已成为该领域研究热点。线粒体分裂融合、线粒体生物发生、线粒体自噬及线粒体运输等构成了线粒体质量控制系统,进而调节线粒体功能。因此,线粒体质量控制系统在脓毒症相关性脑病发生发展中具有重要作用。本文总结线粒体质量控制系统的主要调控机制及在脓毒症相关性脑病中的研究进展,并探讨线粒体质量控制系统在脓毒症相关性脑病评估和防治中的潜在价值。     

脑肠肽对脓毒症相关性肾损伤的保护作用研究

目的 探讨脑肠肽对内毒素所致大鼠脓毒症相关性肾损伤的影响.方法 健康雄性SD大鼠36只,随机分为3组：正常对照组,急性肾损伤（acute kidney injury,AKI）组,脑肠肽治疗组.采用内毒素静注制备脓毒症AKI模型,脑肠肽治疗组于造模前后30 min给予皮下注射脑肠肽（1.0mg/kg）,选择不同时间点（6 h、12 h、24 h）处死动物后留取血标本和肾组织,检测血清肌酐（SCr）、尿素氮（BUN）、血清肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）、观察肾组织的病理变化并检测肾脏组织中核因子κB的活化.结果 与同时间点比较,AKI组6h和12 h大鼠血清中TNF-α表达水平明显升高（P＜0.01）,24 h降至对照组水平（P＞0.05）,AKI组6h、12 h和24 h大鼠血清中BUN水平逐渐升高（P＜0.05）,24 h血清中SCr水平明显升高（P＜0.01）;AKI组24 h大鼠肾脏组织核因子κB p65核阳性率明显升高（P＜0.01）.脑肠肽治疗组对应时间点血清BUN和SCr水平较AKI组明显降低（P＜0.01）.TNF-α和核因子κB p65表达明显低于AKI组（P＜0.01）.病理显示脑肠肽治疗组大鼠肾损伤减轻,SCr、BUN、TNF-α、光镜检查均未见明显差异.结论 脑肠肽可通过抑制肾组织核因子κB的表达,下调TNF水平,对脓毒症相关性肾损伤发挥保护作用.     

脓毒症心肌损伤的线粒体机制研究进展

脓毒症是机体对于感染的失控反应所导致的威胁生命的器官功能障碍,心肌损伤是脓毒症常见的并发症,而线粒体作为心肌细胞能量供应的主要场所,其结构和功能障碍在其中起重要作用。文章旨在总结脓毒症时线粒体功能障碍而导致心肌损伤的相关机制：线粒体内活性氧产生和氧化应激、线粒体能量代谢障碍、线粒体动力学失衡、线粒体生物合成和自噬过程异...     

生物标志物在脓毒症急性肾损伤早期诊断的应用价值

脓毒症是由于宿主对感染的反应失调而导致危及生命的器官功能障碍.肾脏作为严重脓毒症的常见受损靶器官之一,发病率高,预后极差.如不能早期诊断,可显著增加患者治疗难度及病死率,使肾脏替代治疗(renal replacement therapy,RRT)使用率增加,机械通气、重症监护病房住院时间延长、增加医疗费用以及消耗医疗资...     

重视脓毒症性急性肾损伤

脓毒症（Sepsis）和脓毒症休克是引起ICU患者急性肾损伤（AKI）最重要的原因,一项23个国家54家医院参与的研究显示47．5％的ICU患者AKI病因是脓毒症,脓毒症性AKI住院病死率明显高于非脓毒症性AKI（70．2％VS51．8％）。我院一组203例AKI患者流行病学分析显示46．3％的患者伴有各种感染,31％可诊断为脓毒症相关性AKI。     

氯沙坦对脓毒症小鼠急性肾损伤的影响及其与线粒体融合-分裂的关系

目的评价氯沙坦对脓毒症小鼠急性肾损伤的影响及其与线粒体融合-分裂的关系。方法 SPF级雄性C57BL/6J小鼠128只, 6～8周龄, 体质量20～25 g, 采用随机数字表法分为4组(n=32):假手术组(Sham组)、假手术+氯沙坦组(Sham+LOS组)、脓毒症相关性急性肾损伤组(SA-AKI组)及脓毒症相关性急性肾损伤+氯沙坦组(SA-AKI+LOS组)。采用盲肠结扎穿孔法建立小鼠脓毒症模型。Sham+LOS组及SA-AKI+LOS组分别于假手术或造模前3 d开始, 腹腔注射氯沙坦5 mg/kg, 1次/d, 连续3 d;Sham组及SA-AKI组腹腔注射等量溶剂。随机取20只小鼠, 观察术后7 d生存情况。于假手术或造模后24 h, 采用比色法测定血清BUN及Cr浓度, 采用ELISA法测定血清TNF-α、IL-6和高迁移率族蛋白B1(HMGB1)浓度;取肾组织, HE染色后光镜下观察病理学结果, 并行肾小管损伤评分, 采用荧光素酶法测定ATP含量, 采用JC-1法测定线粒体膜电位(MMP)水平, 采用Western blot法检测动力相关蛋白1(Drp1)及线粒体融合蛋白2...     

右美托咪定对脓毒症小鼠急性肾损伤的影响

目的 探讨右美托咪定对脓毒症小鼠急性肾损伤的影响及与肾脏细胞焦亡的关系。
方法 健康清洁级ICR小鼠32只,雌雄各半,8~12周龄,体重20~25 g。采用随机数字表法将小鼠分为四组：对照组（C组）、脂多糖（LPS）组（L组）、LPS+右美托咪定组（LD组）和LPS+右美托咪定+阿替美唑组（LT组）,每组8只。L组、LD组和LT组腹腔注射LPS 400 μg/kg,8 h后腹腔注射LPS 10 mg/kg建立脓毒症急性肾损伤模型。L组于建模即刻、建模后0.5、2、2.5、4、4.5 h腹腔注射生理盐水0.5 ml;LD组于建模即刻、建模后2、4 h腹腔注射生理盐水0.5 ml,于建模后0.5、2.5、4.5 h分别腹腔注射右美托咪定40 μg/kg;LT组于建模即刻、建模后2、4 h腹腔注射阿替美唑750 μg/kg,于建模后0.5、2.5、4.5 h分别腹腔注射右美托咪定40 μg/kg;C组在各时点腹腔注射等量生理盐水。所有小鼠于建模后24 h麻醉处死。采用全自动生化分析仪检测血清肌酐（Scr）和尿素氮（BUN）浓度,化学发光法测量肾皮质细胞三磷酸腺苷(ATP)和血清ATP浓度,ELISA法检测肾组织IL-1β和IL-18浓度,qRT-PCR法检测肾组织caspase-11、泛连接蛋白1（pannexin-1）、P2X7 mRNA表达量,Western blot法检测肾组织caspase-11、pannexin-1、P2X7蛋白含量,HE染色法观察肾组织病理结构,TUNEL染色记录肾小管上皮细胞凋亡细胞数并计算细胞凋亡率。
结果 与C组比较,L组、LD组和LT组血清BUN、Scr、ATP浓度均明显升高（P<0.05）,肾皮质细胞ATP浓度明显降低（P<0.05）,肾组织IL-1β和IL-18浓度、肾组织caspase-11、pannexin-1、P2X7 mRNA表达量及蛋白含量均明显升高（P<0.05）,肾小管上皮细胞凋亡率明显升高（P<0.05）。与L组比较,LD组血清Scr、BUN、ATP浓度均明显降低（P<0.05）,肾皮质细胞ATP浓度明显升高（P<0.05）,肾组织IL-1β浓度、肾组织caspase-11、pannexin-1 mRNA表达量均明显降低（P<0.05）,肾小管上皮细胞凋亡率明显降低（P<0.05）;LD组和LT组肾组织IL-18浓度、肾组织caspase-11、pannexin-1蛋白含量、肾组织P2X7 mRNA表达量及蛋白含量均明显降低（P<0.05）。与LD组比较,LT组血清BUN、Scr、ATP浓度均明显升高（P<0.05）,肾皮质细胞ATP浓度明显降低（P<0.05）,肾组织IL-1β和IL-18浓度、肾组织caspase-11、pannexin-1、P2X7 mRNA表达量及蛋白含量均明显升高（P<0.05）,肾小管上皮细胞凋亡率明显升高（P<0.05）。
结论 右美托咪定减轻了LPS导致的脓毒症小鼠肾脏病理学损伤,降低肾组织IL-1β和IL-18浓度,降低肾小管上皮细胞凋亡率,可能通过非经典途径减轻了肾脏细胞焦亡。     

右美托咪定预防造影剂诱导急性肾损伤机制的研究进展

造影剂诱导急性肾损伤（CI-AKI）是在血管内应用造影剂（CM）进行诊断或治疗性血管造影干预后观察到的医源性急性肾损伤（AKI）。造影剂通过肾小管毒性、肾内血管收缩和活性氧（ROS）的过量产生等方面导致肾功能受损。右美托咪定（DEX）是一种选择性α₂肾上腺素能受体激动药,具有良好的抗氧化、抗炎作用,在围手术期的器官保护作用日益突显。DEX对患者术后肾功能具有保护作用。本文旨在对DEX对CI-AKI的预防作用、可能机制以及临床应用的研究进展作一综述。     

Role of OMA1 in lipopolysaccharide-induced acute kidney injury

Objective To investigate the role of OMA1 in acute kidney injury (AKI) induced by lipopolysaccharide (LPS). Methods OMA1 wild-type and knocked out mice (8 week old) were injected with 10 mg/kg body weight of LPS. The model was confirmed by testing mouse serum creatinine and blood urea nitrogen. The apoptosis in mouse kidney cortex was examined by TUNEL staining and cleaved caspase 3. In vitro, in humam kidney proximal tubular cells (HK2) were knocked down OMA1 by transfecting OMA1 shRNA, with the scramble shRNA being used as negative control of transfection. HK2 cells were cultured with 5 μg/ml of LPS for 24 hours to induce apoptosis. DAPI staining of cells and caspase-3 activity were applied to test apoptosis. The images of mitochondria in cells were obtained by transfection of mito-green plasmid and OMA1 shRNA. Western blotting was used to exam the OMA1 and Cytochrome C expressions. Results Compared with OMA1 KO mice, LPS induced more severe AKI of WT mice with higher Scr [(97.2±26.5) μmol/L vs (53.0±17.7) μmol/L, P＜0.05] and BUN [(43.3±13.7) mmol/L vs (29.7±7.7) mmol/L, P＜0.05]. Moreover, there were more apoptosis cells in kidney cortex in WT mice than in OMA1 KO mice [(75.4± 26.1)/mm2 vs (38.3± 14.4)/mm2, P＜0.05]. About 46% of OMA1 expressions in HK2 cells were inhibited by OMA1 shRNA transfection (P＜0.05). Further, OMA1 shRNA cells with LPS stimulation had decreased mitochondria fragmentation [(29.8±10.9)% vs (43.2±6.8)% , P＜0.05], Cytochrome C release [(37.0±12.3)% vs (76.0±26.2)%, P＜0.05], and cell apoptosis [(13.2±3.9)% vs (25.0±7.1)%, P＜0.05] as compared with control cells. Conclusion Knockdown of OMA1 alleviated septic AKI through inhibition of cell apoptosis, mitochondria fragmentation, and Cytochrome C release.     

乌司他丁对脓毒症致大鼠急性肾损伤肾功能及尿相关指标的影响

目的探讨乌司他丁（UTI）对盲肠结扎穿孔术（CLP〉所致大鼠脓毒症急性肾损伤（AKI）的保护作用。方法SD健康雄性大鼠55只,按随机化原则分成3组：正常对照组5只、模型组25只、乌司他丁治疗组25只,后两组再随机分为5个时间点（1h、6h、12h、24h、48h）,每组每时间点各5只,采用盲肠结扎穿孔术复制脓毒症模型,乌司他丁治疗组,造模后立即给予乌司他丁10万U／kg,尾静脉注射,分别在各个时间点采血、留尿标本,进行肾功能血肌酐（Scr）、尿素（Urea）,尿肾损伤分子（KIM-1）、白细胞介素-18（IL-18）和中性粒细胞明胶酶相关脂质运载蛋白（NGAL）检测分析。结果与模型组相比,乌司他丁治疗组大鼠各时间点Scr、Urea,尿KIM-1、IL-18、NGAL浓度均显著降低,差异均有统计学意义（P〈0．05）。结论乌司他丁对脓毒症所致急性肾损伤具有一定的肾脏保护作用。     

Epidemiology of acute kidney injury in surgical intensive care at University Hospital in Egypt. A prospective observational study

IntroductionThe acute kidney injury (AKI) incidence in ICU patients varies widely from 3% to 30%, with mortality ranging from 36% to 90%, depending on the type of ICU, study population, the period during which the study is conducted, and the criteria used to define AKI.There have been many studies about the epidemiology and risk factors of AKI in critically ill patients in the different regions of the world. However, little data on the epidemiology of AKI in critically ill patients are available in Egypt.ObjectivesThe aim of this study was to assess the incidence of AKI among critical ill patients using RIFEL [risk (R), injury (I), failure (F), loss (L), and end-stage kidney disease (E)] classification and to determine the risk factors and outcome of patients who developed AKI in our surgical ICU.MethodsWe conducted a 6-month prospective observational study in the surgical ICU. Patients were classified daily using the RIFLE criteria. Patients were considered as having new AKI if they did not have AKI on ICU admission and subsequently reached at least class risk during their follow-up. Deterioration of AKI was diagnosed if the patient had increased in RIFLE class compared to the initial classification.ResultsOne hundred and twelve patients were studied. AKI occurred in 40 (35.7%) of patients. The most common risk factors for AKI are APACHE II score (acute physiology and chronic health evaluation score, version II.) and sepsis. APACHEII was lower in non-AKI group than AKI group (17.3 ± 7.5 versus 22.4 ± 7.4, p = 0.001), and sepsis was more common in AKI patients than non-AKI patients (77.5% versus 49% p = 0.004). Patients with AKI had a mortality rate of 67.5% which was more in patients with failure compared with risk patients. APACHEII, AKI, and needs for mechanical ventilation were independent risks for mortality.     

Isoliquiritigenin attenuates septic acute kidney injury by regulating ferritinophagy-mediated ferroptosis

Defined differently from apoptosis, necrosis, and autophagy, ferroptosis has been implicated in acute kidney injury (AKI) such as ischemia-reperfusion injury induced AKI, folic acid caused AKI and cisplatin induced AKI. However, whether ferroptosis is involved in LPS induced AKI could be remaining unclear and there is still a lack of therapies associated with ferroptosis in LPS induced AKI without side effects. This study aimed to elucidate the role of isoliquiritigenin (ISL) in ferroptosis of LPS-induced AKI. We used LPS to induce renal tubular injury, followed by treatment with ISL both in vitro and in vivo. Human renal tubular HK2 cells were pretreated with 50 μM or 100 μM ISL for 5 h before stimulation with 2 μg/mL LPS. Mice were administered a single dose of either 50 mg/kg ISL orally or 5 mg/kg ferroptosis inhibitor ferrostatin-1 intraperitoneally before 10 mg/kg LPS injection. We found that LPS could induce mitochondria injury of renal tubular presented as the shape of mitochondria appeared smaller than normal with increased membrane density and are faction or destruction of mitochondrial crista through scanning electron microscope. Ferrostatin-1 significantly protected mice against renal dysfunction and renal tubular damage in LPS-induced AKI. ISL inhibited Fe²⁺ and lipid peroxidation accumulation in LPS-stimulated HK2 cells. It also increased the expression of GPX4 and xCT, reduced the expression of HMGB1 and NCOA4 then attenuated mitochondria injury in renal tubular following LPS stimulation. These results indicated the potential role of ISL against ferritinophagy-mediated ferroptosis in renal tubular following LPS stimulation.     

Mitochondrial dysfunction in the process of cisplatin-induced acute kidney injury in mice

Objective To assess the characteristics of different doses of cisplatin-induced acute kidney injury, further to understand mitochondrial dysfunction and its role in acute kidney injury (AKI). Methods Male C57BL/6J mice were first randomly divided into two groups: control group (n＝6) and AKI group (n＝12). Then, AKI group was subsequently divided into other two groups according to different dose of cisplatin (10 mg/kg or 20 mg/kg). AKI group received intraperitoneal injection of cisplatin. All mice were sacrificed after 72 h of injection. Renal biochemical function, renal pathological changes, renal injury markers, kidney mitochondrial function and structural changes were observed. Results (1) After 72 hours of injection, the AKI group performed significant kidney injury changes compared to control group, thereinto 20 mg/kg group was more serious than 10 mg/kg group. With the cisplatin dose increasing, renal function markers such as serum creatinine, urine protein gradually increased. (2)Kidney biopsy showed tubular structural damage, the formation of protein casts, kidney injury molecule-1 (KIM-1) gradually increased(P＜0.05). (3)Electron microscopy found tubular mitochondrial structural damage, mtDNA copy number decreased, the level of peroxisome proliferator-activated receptor -gamma coactivator-1alpha (PGC-1α), ATP synthase β decreased(P＜0.05), and Western blotting manifested cytochrome C was released from mitochondria to the cytoplasm. These data all exhibited significant difference between different groups(P＜0.05). Conclusions Cisplatininduces acute kidney injury in dose-dependent manner. Mitochondrial dysfunction participates in kidney injury, and is also related to the kidney pathological damage.