Akt介导炎症反应参与顺铂诱导的急性肾损伤

目的 目前急性肾损伤（acute kidney injury,AKI）发病率和死亡率较高,尤其是肾毒性药物所致AKI更加常见,为了更好地理解和干预AKI,本实验拟研究顺铂诱发的小鼠AKI的潜在发病机制.方法 在小鼠成功构建顺铂诱发的AKI模型基础上,将10只雄性C57BL/6（25-30）克小鼠随机分为2个组,每组6只（n=6）,分为对照组和顺铂诱导的急性肾损伤模型组.模型组腹腔注射顺铂20 mg/kg,对照组腹腔注射生理盐水（20mg/kg）,顺铂或生理盐水注射72 h后处死小鼠,收集小鼠血清和肾脏标本.测定血清肌酐（SCr）和血尿素氮（BUN）.PAS染色后显微镜下观察肾脏形态学变化,Western blotting免疫蛋白印迹分析蛋白激酶B（Akt）和磷酸化蛋白激酶B（p-Akt）的表达,实时定量（RT-PCR）检测白介素-6（IL-6）,干扰素-γ（IFN-γ）和肿瘤坏死因子α（TNF-a）.结果 与对照组相比,模型组SCr和BUN均明显升高,病理检查可见肾脏内肾小管上皮细胞明显肿胀坏死、蛋白管型形成明显,还可观察到炎症细胞浸润明显增加.Western blotting免疫蛋白印迹结果显示pAkt表达明显上调,Akt表达不变,RT-PCR检测显示IL-6,IFN γ和TNFα明显上调.结论 在顺铂导致的小鼠急性肾损伤模型中,Akt的激活通过介导炎症反应参与了顺铂诱导的小鼠急性肾损伤.     

The incidence of acute kidney injury in patients with traumatic brain injury

There is limited information on the incidence of acute kidney injury (AKI) in patients with traumatic brain injury (TBI) although AKI may contribute to morbidity and mortality. We investigated the incidence of AKI in patients with moderate and severe TBI and the association of AKI with risk factors and outcomes in these patients.

We studied all TBI patients over 16 years of age admitted to the two designated trauma hospitals in the state of Victoria, Australia from 1 January to 31 December 2008. Patients were included if they had head trauma and presented with a Glasgow coma scale (GCS) <13. Prospectively collected data from the hospital trauma registries, ICUs, and pathology databases were analyzed retrospectively. Risk injury failure loss end (RIFLE) criteria were used to categorize renal function.

The incidence of AKI was 9.2% (19/207). Patients who developed AKI were older, had higher severity of illness scores, and a lower GCS. Overall 42.1% of these patients died in hospital compared with 18.1% in patients without AKI. In univariable linear regression analysis, age, severity of illness, and admitting hospital were associated with AKI. After multivariable logistic regression, the occurrence of AKI was associated with age (p < 0.001) and higher APACHE III scores (p = 0.016).

AKI is relatively common even in patients with TBI. Its association with age and APACHE III scores helps identify patients at higher risk of AKI.     

Ameliorative effects of pine bark extract on cisplatin-induced acute kidney injury in rats

Objective: This study investigated the dose–response effects of pine bark extract (PBE, pycnogenol^®) on oxidative stress-mediated apoptotic changes induced by cisplatin (Csp) in rats.

Materials and methods: The ameliorating potential of PBE was evaluated after orally administering PBE at doses of 10 or 20?mg/kg for 10 days. Acute kidney injury was induced by a single intraperitoneal injection of Csp at 7?mg/kg on test day 5.

Results: Csp treatment caused acute kidney injury manifested by elevated levels of serum blood urea nitrogen (BUN) and creatinine (CRE) with corresponding histopathological changes, including degeneration of tubular epithelial cells, hyaline casts in the tubular lumen, and inflammatory cell infiltration (interstitial nephritis). Csp also induced significant apoptotic changes in renal tubular cells. In addition, Csp treatment induced high levels of oxidative stress, as evidenced by an increased level of malondialdehyde, depletion of the reduced glutathione (GSH) content, and decreased activities of glutathione S-transferase, superoxide dismutase, and catalase in kidney tissues. On the contrary, PBE treatment lowered BUN and CRE levels and effectively attenuated histopathological alterations and apoptotic changes induced by Csp. Additionally, treatment with PBE suppressed lipid peroxidation, prevented depletion of GSH, and enhanced activities of the antioxidant enzymes in kidney tissue.

Conclusions: These results indicate that PBE has a cytoprotective effect against oxidative stress-mediated apoptotic changes caused by Csp in the rat kidney, which may be attributed to both increase of antioxidant enzyme activities and inhibition of lipid peroxidation.     

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.     

Paradigm shift in the role of uric acid in acute kidney injury

It has been known for decades that uric acid causes acute kidney injury by intratubular crystal precipitation and obstructing the renal tubules. Uric acid crystals stimulate inflammation and elicit immune responses in many disease conditions, including gouty arthritis. More recently, soluble uric acid has been reported to stimulate proliferation of vascular smooth muscle cells, inhibit endothelial function, cause renal vasoconstriction, impair renal blood flow autoregulation, and induce inflammatory response via crystal-independent mechanisms. This article examines the changing role for uric acid in acute kidney injury.     

Renal regeneration after acute kidney injury

Acute kidney injury is common and associated with negative renal and patient outcomes. The human kidney has a real but limited regeneration capacity. Understanding renal regeneration may allow us to manipulate this process and thus develop therapeutic weapons to improve patients’ outcome. In the first part of this paper we discuss the clinical factors associated with renal recovery: baseline patient particularities, acute kidney injury characteristics and the medical approach taken in the short and long‐term. In the second part, the cellular and molecular mechanisms underlying renal regeneration are explored. The immune system seems to have an important role, first promoting inflammation and then tissue healing. Other players, such as cellular senescence, mitochondrial dysfunction, renal haemodynamics and metabolic reprogramming also have a role in renal regeneration. We aim to develop a short review of renal regeneration, offering a holistic view of this process.     

Complement activation is a crucial driver of acute kidney injury in rhabdomyolysis

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Early detection of acute kidney injury: emerging new biomarkers

SUMMARY:   Acute kidney injury (AKI) has recently become the preferred term to describe the syndrome of acute renal failure (ARF) with 'failure' or 'ARF' restricted to patients who have AKI and need renal replacement therapy. ¹ This allows capture of the broader clinical spectrum of modest reductions in creatinine, which are themselves known to be associated with major increases in both short- and long-term mortality risk. ^2–5 It is hoped that this change in nomenclature will facilitate an expansion of our understanding of the underlying pathophysiology and also facilitate definitions of AKI, which allow comparisons among clinical trials of patients with similar duration and severity of illness. This review will cover the need for early detection of AKI and the role of urinary and plasma biomarkers, including enzymuria. The primary message is that use of existing criteria to diagnose AKI, namely elevation of the serum creatinine with or without oliguria, results in identification that is too late to allow successful intervention. New biomarkers are essential to change the dire prognosis of this common condition.     

Amelioration of cisplatin-induced acute kidney injury by recombinant neutrophil gelatinase-associated lipocalin

We investigated the protective effect and mechanism of neutrophil gelatinase-associated lipocalin (NGAL) in a murine model of cisplatin-induced nephrotoxicity. Male Swiss-Webster mice were assigned to four groups (n?=?10 in each group). Control mice received vehicle only. Mice in the experimental group were given a single intraperitoneal injection of cisplatin (20?mg/kg) to induce nephrotoxicity, and were divided into three groups. The first group received 100?μL of saline only via tail vein at the time of cisplatin administration. The second group was given biologically active recombinant NGAL via tail vein (250?μg/100?μL solution). The third group was injected with a 250?μg/100μL solution of inactivated NGAL. After 4 days, we measured serum creatinine and urinary N-acetyl-β-d-glucosaminidase (NAG), and performed histologic studies. Biologically active NGAL significantly blunted the rise in serum creatinine (NGAL plus cisplatin 1.33?±?0.31 versus cisplatin alone 2.43?±?0.31?mg/dL, p?<?.001) as well as the increase in urine NAG (NGAL plus cisplatin 60.7?±?14.2 versus cisplatin alone 120.5?±?22.5 units/gm creatinine, p?<?.005). In addition, NGAL conferred a marked reduction in tubule cell necrosis and apoptosis (NGAL plus cisplatin 6.9?±?1.2 versus cisplatin alone 15.1?±?3.4 TUNEL positive nuclei per 100 cells, p?<?.001). These beneficial effects were completely abolished when heat-inactivated NGAL was administered instead of the biologically active form. Since induction of NGAL in kidney tubules is a known physiologic response to cisplatin, the pharmacologic use of NGAL to prevent cisplatin nephrotoxicity is likely to be safe and effective.     

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ICU中急性肾损伤(AKI)病人营养支持的主要目的在于确保适当的热量,预防组织蛋白和瘦肉组织不必要的浪费,改善组织修复,支持免疫系统,降低病死率。应首选肠内途径,但即便如此,仍然经常需要辅以肠外营养,以满足目标营养的需求。需要特别关注肾脏替代治疗(RRT)对三大营养素和微量营养素的影响以及可能导致并发症的防范。事实上,由于肾脏体液平衡功能的急性丢失,常需要RRT治疗,AKI病人尤其易出现血糖异常、高甘油三酯血症以及体液、酸碱、电解质的失衡。     

The protective effect of ozone oxidative preconditioning against hypoxia/reoxygenation injury in rat kidney cells

Ozone (O3) has been viewed as a novel treatment for different diseases in these years and oxidative stress and apoptosis play a key role in the pathogenesis of kidney diseases including renal ischemia and reperfusion (I/R). In the present study, we investigated the role of ozone oxidative preconditioning (OzoneOP) in attenuating oxidative stress and apoptosis in a hypoxia/reoxygenation (H/R) injury model using rat kidney cells. We induced H/R injury in kidney cells treated with or without OzoneOP. Oxidative stress parameters such as superoxide dismutase (SOD), malondialdehyde (MDA) and lactate dehydrogenase (LDH) were determined, as well as some apoptotic proteins. We observed that oxidative stress and apoptosis were increased in H/R group compared to OzoneOP group; however, these changes were significantly decreased by the treatment with OzoneOP. We concluded that OzoneOP can protect the kidney cells against H/R injury and its mechanism may be through the reduction of oxidative stress and apoptosis.     

吗啡预处理减轻小鼠海马神经元氧-糖缺失/恢复损伤的影响因素

目的 探讨吗啡预处理减轻小鼠海马神经元氧-糖缺失/恢复损伤的影响因素(剂量和作用时间窗).方法 急性分离小鼠海马组织,制备脑片,行4部分实验,实验Ⅰ:应用吗啡0.1、0.3、0.5、1.0、3.0、10.0 μmol/L孵育脑片30 min,再常规培养30 min,缺氧无糖20 min,复氧复糖2 h.实验Ⅱ:应用吗啡3.0 μmol/L孵育脑片5、15、30、45、60 min,再常规培养30 min,缺氧无糖20 min,复氧复糖2 h.实验Ⅲ:应用吗啡3.0 μmol/L孵育脑片30 min,再常规培养即刻、5、15、30、60、120 min时行缺氧无糖20 min,复氧复糖2 h.实验Ⅳ:应用蛋白激酶C(PKC)非特异性抑制剂白屈菜赤碱10 μmol/L、选择性新奇型PKCε(nPKCε)抑制剂εVI.2 2 μmol/L、特异性钙-钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)抑制剂AIP 2 μmol/L、N.甲基-D-天冬氨酸(NMDA)受体特异性阻断剂MK-801 10 μmol/L孵育脑片30 min,再与吗啡3.0 μmol,L共同孵育30 min,常规培养30 min,缺氧无糖20 min,复氧复糖2 h.计算神经元存活率.结果 与氧-糖缺失/恢复组比较,吗啡0.5、1.0、3.0、10.0 μmol/L预处理组、吗啡预处理15、30、45、60 min组、吗啡预处理后常规培养即刻、5、15、30、60 min组神经元存活率升高(P<0.05).PKC、nPKGt、CaMKⅡ抑制剂和NMDA受体阻断剂可部分抑制吗啡预处理升高神经元存活率的作用.结论 有效减轻小鼠海马神经元氧-糖缺失,恢复损伤的吗啡预处理方式为:浓度0.5～1.0 μmol/L,持续时间15～60 min,间隔时间小于60 min;其保护作用可能部分依赖于PKC、nPKCε、CaMKⅡ的活化和NMDA受体的激活.     

Recurrent acute kidney injury following bath salts intoxication

"Bath salts" are becoming recognized as a frequently abused and highly addictive substance that can be obtained legally in some areas. These agents contain stimulant compounds, such as methylenedioxopyrrovalerone and mephedrone, that have been associated with sympathomimetic effects and psychotic features, such as paranoia, delusions, agitation, and confusion. They may have a benign course; however, intoxication with these agents may lead to severe cardiovascular and neurologic complications and death. We report a case of recurrent acute kidney injury associated with repeated bath salts intoxication. The patient, who presented with neurologic and cardiovascular symptoms and signs, also developed rhabdomyolysis, hyperuricemia, and metabolic acidosis as part of the clinical presentation. Bath salts intoxication should be included on the list of substances that can cause acute kidney injury and other metabolic abnormalities.     

Postpartum acute kidney injury: a review of 99 cases

Postpartum acute kidney injury (PPAKI) constitutes an important cause of obstetric AKI. It is associated with high maternal and fetal mortality in developing nations. The aim of this study is to survey the etiology and outcomes of PPAKI in a tertiary care Indian hospital. Ninety-nine patients, without prior comorbidities, treated for PPAKI, between 2005–2014 at M.S. Ramaiah Medical College, were included for analysis in this retrospective, observational study. AKI was analyzed in terms of maximal stage of renal injury attained as per RIFLE criteria. Outcomes included requirement for renal replacement therapy (RRT), maternal and fetal outcomes. PPAKI constituted 60% of all obstetric AKI cases. Median maternal age was 23 years and 52% of patients were primigravidas. Mean serum creatinine was 4.1?mg/dL. Failure (33%) and injury (31%) were the major categories as per RIFLE criteria. Thirty-nine percent of cases required RRT. Sepsis, particularly puerperal sepsis, was the leading causes of PPAKI (75% of cases) and maternal mortality (94% of deaths). Maternal and fetal mortality were 19% and 22% respectively. The incidence of cortical necrosis was 10.3%. Three patients required long-term RRT. In conclusion, consistent with other Indian literature, we report a high incidence of PPAKI. We found incremental mortality on moving from “Risk” to “Failure” category of RIFLE. PPAKI was associated with high maternal and fetal mortality with sepsis being the leading cause. Our study highlights the need for provision of better quality of maternal care and fetal monitoring to decrease mortality associated with PPAKI in developing countries.     

Kidney outcomes and prognostic factors of myeloma associated acute kidney injury in the contemporary era

Myeloma cast nephropathy (MCN) has historically been associated with poor kidney outcomes. We aimed to evaluate the kidney outcomes and identify prognostic factors of myeloma-associated acute kidney injury (M-AKI) in the contemporary era of anti-plasma cell therapy. Patients who received anti-myeloma therapy with M-AKI (January 2012 to June 2020) from a single centre were identified from electronic medical records. Diagnosis of MCN was either biopsy confirmed (BC) or clinically suspected (CS), the latter defined as acute kidney injury with reduced estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m² and involved serum free light chains (iSFLC) >500 mg/L at diagnosis. Twenty-six patients with M-AKI were identified (BC: n = 13, CS: n = 13). Median eGFR at diagnosis was 12 (interquartile range 6–20) mL/min/1.73 m². All six dialysis-requiring patients achieved dialysis independence after 71 (43–208) days. The best-achieved eGFR was 47 (32–67) mL/min/1.73 m² after 120 (63–167) days post-treatment, which was maintained at 47 (33–66) mL/min/1.73 m² 12 months post-treatment. Patients with best-achieved eGFR above the median were more likely to have achieved an iSFLC of <20 mg/L (above median group 62% versus below median group 0%; p < .001) and lower best post-treatment iSFLC (20 (12–90) versus 67 (29–146) mg/L; p < .05). Best-achieved iSFLC was a prognostic factor for superior eGFR following treatment for M-AKI. Despite low eGFR at diagnosis, contemporary anti-myeloma therapy can achieve significant recovery of kidney function.     

Reduction of natural killer and natural killer T cells is not protective in cisplatin-induced acute renal failure in mice

Aims: A recent report showed that fractalkine (CX3CL1), which functions as both a potent chemoattractant and adhesion molecule for monocytes and natural killer (NK) cells was significantly increased in cisplatin‐induced acute renal failure (CisARF) in mice. Therefore, we developed the hypothesis that increased CX3CL1 expression in CisARF initiates NK cell infiltration in the kidney. The aim of the present study was to determine the role of NK cells in CisARF in mice. Methods: Time course of pan‐NK positive cells in CisARF was investigated by using immunohistochemistry (IHC) for CD49b. Pan‐NK positive cells were reduced by using anti‐NK1.1 mAb. The model of pan‐NK positive cells reduction was confirmed by flow cytometry of the spleen and IHC of the kidney. The expression of granzyme A and caspase‐1 was examined, and the activity of caspase‐1 was also determined. We performed a study on whether there was significant protection of renal function after reduction of pan‐NK positive cells. Results: (i) Infiltration of pan‐NK positive cells was prominent on day 3 after cisplatin administration. (ii) granzyme A expression was significantly increased in CisARF and CisARF+NK1.1 Ab compared to vehicle. (iii) Caspase‐1 expression and activity was significantly increased in CisARF mice compared to vehicle and CisARF+NK1.1 Ab. (iv) Reduction of pan‐NK positive cells was not protective in cisplatin‐induced acute renal failure in mice. Conclusions: Although infiltration of pan‐NK cells was significantly increased in CisARF, reduction of infiltration of pan‐NK cells into the kidney was not protective against CisARF in mice.