Nrf2 / HO-1通路在电针减轻肢体缺血再灌注诱发兔肺损伤中的作用

目的:观察核因子E2相关因子2(Nrf2)/血红素氧合酶-1(HO-1)信号通路在电针减轻肢体缺血再灌注诱发兔肺损伤中的作用。方法:40只健康雄性新西兰大白兔,采用随机数字表法分为假手术组、模型组、电针组和全反式维甲酸组(n=10)。采用夹闭股动脉3 h、再灌注4 h的方法制备兔肢体缺血再灌注模型;电针组、全反式维甲酸组于模型制备前1～4 d(30 min/次,1次/d)及模型制备过程中电针足三里穴和肺俞穴,采用疏密波2/15 Hz,强度以兔出现轻微肌颤为宜;全反式维甲酸组于模型制备前30 min腹腔注射Nrf2抑制剂全反式维甲酸7 mg/kg。再灌注4 h时采集颈动脉血样,随后处死兔取肺组织,观察病理学结果并行肺损伤评分,计算肺湿/干重(W/D)比值;测定肺组织MDA含量及SOD活性,采用Western blotting法检测肺组织Nrf2总蛋白、Nrf2核蛋白及HO-l蛋白表达水平。结果:模型组、电针组和全反式维甲酸组再灌注4 h时肺损伤评分分别为5.43±0.82、4.03±0.56、6.21±0.75,均明显高于假手术组(0.92±0.21,P0.05);肺组织W/D比值分别为6.42±1.00、4.45±0.68、7.08±1.12,均明显高于假手术组(2.04±0.29,P0.05);MDA含量分别为(4.82±0.51)nmol/mg、(3.56±0.45)nmol/mg、(5.18±0.47)nmol/mg,均明显高于假手术组(2.10±0.23)nmol/mg,P0.05;SOD活性分别为(50.6±6.3)U/mg、(63.1±7.7)U/mg、(47.2±5.6)U/mg,均明显低于假手术组(72.6±6.3)U/mg,P0.05;Nrf2总蛋白、Nrf2核蛋白及HO-l蛋白表达水平均明显高于假手术组(P0.05)。与模型组比较,电针组再灌注4 h时肺损伤评分、肺组织W/D比值、MDA含量均明显降低(P0.05),SOD活性、Nrf2总蛋白、核蛋白及HO-l蛋白表达水平均明显升高(P0.05)。与电针组比较,全反式维甲酸组再灌注4 h时肺损伤评分、肺组织W/D比值、MDA含量均明显升高(P0.05),SOD活性、Nrf2总蛋白、核蛋白及HO-l蛋白表达水平均明显降低(P0.05)。结论:Nrf2/HO-1信号通路激活参与了电针减轻肢体缺血再灌注诱发兔肺损伤的过程。     

The possible role of interleukin-33 as a new player in the pathogenesis of contrast-induced nephropathy in diabetic rats

Introduction: Patients with diabetic kidney disease (DKD) are more prone to contrast-induced nephropathy (CN). Apoptosis and autophagy were found to be essential in the pathogenesis of DKD. Interleukin-33 (IL-33) is a cytokine, but its role in DKD and CN is unknown. As IL-33 is modulated by apoptosis, we aimed to determine the relationship between IL-33 apoptosis and autophagy in DKD with CN. Materials and methods: Thirty male Sprague–Dawley rats were enrolled and randomly allocated into three groups. The first group was comprised of healthy rats (HRs), whereas the other two groups were made up of diabetic rats (DRs) and diabetic rats with CN (DRs?+?CN). All groups except the HRs received 50?mg/kg/day of streptozotocin (STZ). The DRs?+?CN group was induced by administering 1.5?mg/kg of intravenous radiocontrast dye on the 35th day. Results: We observed increased IL-33 in the kidney tissue following induction of CN in the DRs. The DRs showed moderate immunopositivity, and the DRs?+?CN showed severe immunopositivity for caspase-3, cleaved caspase-3, caspase-8, caspase-9, LC3B, and Beclin-1 in tubular cells and glomeruli. The DRs also showed moderate immunopositivity in tubular cells, and the DRs?+?CN group showed severe immunopositivity for IL-33 in tubular cells. Increased caspase-3 was found in both glomeruli and tubuli; however, we could not demonstrate IL-33 in glomeruli. This could be secondary to inactivation of IL-33 via increased caspase-3 activity. Conclusion: The release of IL-33 from necrotic cells might induce autophagy, which can further balance the effects of increased apoptosis secondary to CN in DKD.     

The endothelium in diabetic nephropathy

The long-term complications of diabetes are characterized by pathologic changes in both the microvasculature and conduit vessels. Although the fenestrated glomerular endothelium classically has been viewed as providing little in the way of an impediment to macromolecular flow, increasing evidence illustrates that this is not the case. Rather, hyperglycemia-mediated endothelial injury may predispose to albuminuria in diabetes both through direct effects and through bidirectional communication with neighboring podocytes. Although neo-angiogenesis of the glomerular capillaries may be a feature of early diabetes, particularly in the experimental setting, loss of capillaries in the glomerulus and in the interstitium are key events that each correlate closely with declining glomerular filtration rate in patients with diabetic nephropathy. The hypoxic milieu that follows the microvascular rarefaction provides a potent stimulus for fibrogenesis, leading to the glomerulosclerosis and tubulointerstitial fibrosis that characterize advanced diabetic kidney disease. Given the pivotal role the endothelium plays in both the development and the progression of diabetic nephropathy we need effective strategies that prevent its loss or accelerate its regeneration. Such advances likely will lead not only to improved tissue oxygenation and reduced fibrosis, but also to improved long-term renal function.     

Association of plasminogen activator inhibitor-1 gene polymorphism and type 2 diabetic nephropathy

Background: We investigated the relationship between plasminogen activator inhibitor-1 (PAI-1) 4G/5G insertion/deletion polymorphism and prevalence of diabetic nephropathy (DN) in Chinese patients. Methods: A total of 107 patients with type 2 diabetes were randomly recruited in the study, and 102 healthy subjects were selected as Control. Patients were divided into three groups according to their urinary albumin–creatinine ratio (UACR). Group A (n?=?44), had patients without DN (serum creatinine <106?µmol/L and UACR <30?µg/mg); Group B (n?=?30), had patients with micro-albuminuria (UACR 30–299?µg/mg), and Group C (n?=?33), had patients with macro-albuminuria (UACR ≥300?µg/mg and creatinine <200?µmol/L). Plasma level of PAI-1 was measured by ELISA. PAI-1 polymorphism was determined by a polymerase chain reaction (PCR) method and DNA sequencing. Results: (1) The plasma PAI-1 levels of group A (60.39?±?17.01?ng/L), group B (68.76?±?17.81?ng/L) and group C and (68.63?±?18.30?ng/L) are higher than that of controls (46.26?±?26.04?ng/L); (2) Patients with genotype 4G/4G tended to exhibit higher PAI-1 level; (3) The distribution frequency of genotype 4G/4G in group C was significantly higher than in group A (42.4% vs. 28.7%, p?Conclusions: (1) Plasma PAI-1 level was elevated in Type 2 diabetic patients; (2) The level of plasma PAI-1 is closely related to PAI-1 gene 4G/5G polymorphism and (3) PAI-1 4G/5G polymorphism is associated with the development and progression of predominant proteinuria diabetes nephropathy.     

莱菔硫烷通过Nrf2-ARE通路减轻大鼠移植心脏冷缺血再灌注损伤

目的 探讨莱菔硫烷(SFN)是否通过核因子相关因子2-抗氧化反应元件(Nrf2-ARE)通路对抗大鼠心脏移植冷缺血再灌注损伤.方法 健康雄性Sprague-Dawley(SD)大鼠40只随机分成3组:假手术组(Sham组,n=8),缺血再灌注组(I/R组,n=16),莱菔硫烷预处理组(I/R+ SFN组,n=16).建立大鼠异体异位心脏移植模型,将冷藏于4℃ HTK液9h的供心移植到I/R组和I/R+ SFN组受体大鼠腹腔,移植后24h取出移植心脏.Sham组开/关腹24 h后取出自体心脏.应用HE染色法、免疫组织化学法及western blot方法观察心肌组织学、核因子相关因子2(Nrf2)、血红素加氧酶1(HO-1)、醌氧化还原酶1(NQO1)的蛋白表达水平.结果 与I/R组比较,I/R+ SFN组心肌组织损伤减轻,心肌组织Nrf2核蛋白、Nrf2、HO-1和NQO1蛋白水平显著升高(P＜0.01).与Sham组比较,I/R+ SFN组心肌组织学和心肌组织Nrf2核蛋白、Nrf2、HO-1和NQO1蛋白水平仍高于正常(P＜0.01).结论 莱菔硫烷通过激活Nrf2-ARE通路,上调下游蛋白HO-1、NQO1表达,提高心肌细胞对氧化应激的防御能力,对抗移植心脏冷缺血再灌注损伤.     

Nrf2-ARE通路在自噬过程中的变化及其对肝癌细胞周期的影响

肝癌是我国常见的恶性肿瘤之一,在其发生过程中,自噬活性以及Nrf2-ARE通路的改变发挥着重要作用.Nrf2属于CNC家族,是肝癌的重要调节剂,自噬抑制后Nrf2-ARE通路活化有助于研究肝癌的发生发展.本文旨在探讨自噬与Nrf2-ARE通路的相互关系及其对肝癌的影响.     

The predictive value of diabetic retinopathy on subsequent diabetic nephropathy in patients with type 2 diabetes: a systematic review and meta-analysis of prospective studies

This systematic review and meta-analysis aimed to assess the predictive value of diabetic retinopathy (DR) on further diabetic nephropathy (DN) risk in patients with type 2 diabetes (T2D) based on the prospective cohort studies. PubMed, Embase, and the Cochrane Library were systematically searched for eligible prospective cohort studies through March 2020. The predictive value of DR was assessed using sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC) through the bivariate generalized linear mixed model and the random-effects model. Ten prospective cohort studies recruited 635 patients with T2D. The pooled sensitivity and specificity of DR for predicted DN were noted to be 0.64 (95% CI, 0.54–0.73) and 0.77 (95% CI, 0.60–0.88), respectively. The pooled PLR and NLR of DR for predicted DN were 2.72 (95% CI, 1.42–5.19) and 0.47 (95% CI, 0.33–0.67), respectively. The summary DOR for the relationship between DR and subsequent DN for T2D patients was 5.53 (95% CI, 2.00–15.30), and the AUC of DR for predicted DN was 0.73 (95% CI, 0.69–0.77). This study found significant associations between DR and subsequent DN risk for patients with T2D. Moreover, the predictive value of DR on subsequent DN risk was relatively lower.     

2型糖尿病肾病并发骨质疏松大鼠模型研究

目的构建2型糖尿病肾病并发骨质疏松大鼠模型。方法选用SD大鼠,通过喂养高糖高脂饲料4周后,予以链脲佐菌素(STZ 35 mg/kg)进行腹腔注射,继续喂养4周后观察血糖、尿量、尿蛋白及Ca、P等生化指标变化,通过双能X线测量骨密度以及进行生物力学检测骨强度,并取肾、骨组织进行病理检测。结果造模组在高糖高脂饲料喂养后,血糖、尿量及尿蛋白较正常组均逐渐升高,在第4周腹腔注射链脲佐菌素后,造模组的血糖、尿量及尿蛋白较正常组显著升高。在第8周时,造模组的血糖、尿量、尿蛋白及尿Ca、P均明显高于正常组,差异有统计学意义。造模组的骨密度及骨骼强度低于正常组。病理显示造模组大鼠出现肾脏肥大,肾小球毛细血管袢肥大,系膜基质增多肾脏病变以及骨小梁稀疏、变细、连续性中断等骨骼病变。结论通过腹腔注射链脲佐菌素联合8周高糖高脂饮食可建立2型糖尿病肾病并发骨质疏松的大鼠模型,该模型具有高糖、多尿、尿蛋白增加、骨密度下降以及肾小球病变和骨吸收增加的特点。     

Association of angiotensin-converting enzyme insertion/deletion polymorphism with type 1 diabetic nephropathy: a meta-analysis

Objective: This study aimed to systematically evaluate the effect of an angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism on type 1 diabetic nephropathy (DN).

Methods: Cochrane Library, Embase, PubMed, Science Direct, Web of science, Wanfang data, VIP database, China Knowledge Resource Integrated Database, and SinoMed were searched. A total of 17 case–control studies analyzing ACE I/D polymorphism and type 1 DN risk were included in the present meta-analysis.

Results: Overall, a significant increased risk was found in allele comparison (OR?=?1.16, 95% CI?=?1.05–1.28, p?=?0.04), dominant comparison (OR?=?1.56, 95% CI?=?1.14–2.15, p?=?0.006) and homozygote comparison (OR?=?1.52, 95% CI?=?1.06–2.19, p?=?0.02). In subgroup analyses according to ethnicity, the risk of type 1 DN in Asian population was increased in allele comparison (OR?=?1.98, 95% CI?=?1.15–3.42, p?=?0.01), recessive comparison (OR?=?2.48, 95% CI?=?1.51–4.10, p?=?0.0004), dominant comparison (OR?=?3.15, 95% CI?=?1.90–5.23, p?p?=?0.05). However, there was no association between the ACE I/D genetic variants and type 1 DN in Caucasian populations.

Conclusions: Our meta-analysis results indicate that the ACE I/D polymorphism may contribute to type 1 DN development, especially in the Asian groups with type 1 diabetes. The current findings need to be confirmed by future well-designed and larger sample size primary studies in populations with different ethnicities.     

Low birth weight does not increase the risk of nephropathy in Finnish type 1 diabetic patients.

BACKGROUND: Low birth weight (LBW) has been linked to renal disease both in animal models and human studies. However, the role of birth weight in the development of diabetic nephropathy is unclear. We, therefore, studied the impact of birth weight on the development of diabetic nephropathy and other related traits, such as diabetic retinopathy and macrovascular disease, in Caucasian type 1 diabetic patients. METHODS: Data on size at birth were obtained from original birth certificates in 1543 Finnish patients with type 1 diabetes. The patients were divided into those with low (LBW; below the 10th percentile), normal (NBW; 11-90th percentile) and high birth weight (HBW; above the 90th percentile). RESULTS: Diabetic nephropathy was equally common in the groups with various birth weight (LBW vs NBW vs HBW: 21 vs 20 vs 17%, P = NS). End-stage renal disease (3 vs 5 vs 4%, P = NS), laser-treated retinopathy (31 vs 31 vs 31%, P = NS) and macrovascular disease (5 vs 5 vs 8%, P = NS) were equally prevalent in the various birth weight groups. The time from the onset of diabetes to the onset of diabetic nephropathy was similar irrespective of birth weight (log-rank test; P = NS). CONCLUSIONS: Based on our cross-sectional data, LBW does not have an impact on the development of diabetic nephropathy, laser-treated retinopathy or macrovascular disease later in life in Caucasians with type 1 diabetes.     

Protective effect of paraoxonase 1 of high-density lipoprotein in type 2 diabetic patients with nephropathy

Aim:   Paraoxonase 1 (PON1) is an important antioxidative enzyme associated with high-density lipoproteins (HDL). Recent data suggest that HDL antioxidative ability may be altered in type 2 diabetic patients. The aim of this study was, therefore, to investigate whether HDL-PON1 activity and HDL antioxidative ability were related to the presence and severity of diabetic nephropathy.
Methods:   Sixty type 2 diabetic patients, who were subdivided into normoalbuminuria, microalbuminuria and macroalbuminuria, and 20 age- and sex-matched healthy controls were recruited. HDL was then isolated to measure PON1 activity, lipid peroxide and its ability in protecting low-density lipoprotein (LDL) from oxidation.
Results:   HDL-PON1 activity and HDL antioxidative ability in protecting LDL from oxidation was preserved in diabetic patients with normoalbuminuria, but significantly decreased in those with microalbuminuria or macroalbuminuria. HDL peroxide was comparable between healthy controls and normoalbuminuric patients, but significantly increased in those with microalbuminuria or macroalbuminuria. On multiple analyses, urinary protein was an independent negative determinant of HDL-PON1 activity, and HDL-PON1 activity was positively associated with HDL antioxidative ability, and negatively associated with HDL peroxide.
Conclusion:   HDL-PON1 activity is decreased in type 2 diabetic patients with incipient or overt nephropathy, which relates to the reduced HDL antioxidative ability in protecting LDL from oxidation and increased peroxide in HDL.     

Analysis of NO-synthase expression and clinical risk factors in human diabetic nephropathy.

BACKGROUND: Changes of renal nitric oxide (NO) production have been associated with glomerular hyperfiltration, vascular permeability, albuminuria, glomerulosclerosis and tubulointerstitial fibrosis. Several studies demonstrated an up- as well as downregulated expression of NO-synthases (NOS) in experimental diabetic nephropathy. It is still not yet specified whether the regulation and activity of NOS is changed in human diabetic nephropathy. METHODS: Renal biopsies and clinical data of 45 patients with diabetic nephropathy and of 10 control subjects were investigated. Glomerular and cortical endothelial NOS (eNOS) and inducible NOS (iNOS) expression were assessed by immunohistochemical staining and related to clinical data such as the duration of diabetes, insulin therapy and arterial hypertension, albuminuria/proteinuria, eGFR according to the formula modification of diet in renal disease (MDRD), presence of vascular complications or diabetic retinopathy. RESULTS: The mean age of patients at biopsy was 60.3 years and the mean duration of diabetes 12.9 years. Expression of cortical and glomerular eNOS was increased in type 2 diabetes (P < 0.05). Increased expression of glomerular and cortical eNOS correlated with more severe vascular complications (r = 0.44; P < 0.05). Glomerular eNOS was strongly increased among different degrees of proteinuria (P < 0.01). In contrast to expression levels of eNOS, the glomerular expression pattern of iNOS changed from an endothelial pattern in glomeruli with preserved morphology towards expression predominantly by inflammatory cells. CONCLUSIONS: Thus, increased eNOS expression by the renal endothelium could be demonstrated in type 2 diabetic nephropathy, whereas iNOS was unchanged but spatially differentially expressed. The eNOS expression was related to vascular lesions and the degree of proteinuria.     

MicroRNA-122-5p ameliorates tubular injury in diabetic nephropathy via FIH-1/HIF-1α pathway

Diabetes kidney disease (DKD) affects approximately one-third of diabetes patients, however, the specific molecular mechanism of DKD remains unclear, and there is still a lack of effective therapies. Here, we demonstrated a significant increase of microRNA-122-5p (miR-122-5p) in renal tubular cells in STZ induced diabetic nephropathy (DN) mice. Moreover, inhibition of miR-122-5p led to increased cell death and serve tubular injury and promoted DN progression following STZ treatment in mice, whereas supplementation of miR-122-5p mimic had kidney protective effects in this model. In addition, miR-122-5p suppressed the expression of factor inhibiting hypoxia-inducible factor-1 (FIH-1) in vitro models of DN. microRNA target reporter assay further verified FIH-1 as a direct target of miR-122-5p. Generally, FIH-1 inhibits the activity of HIF-1α. Our in vitro study further indicated that overexpression of HIF-1α by transfection of HIF-1α plasmid reduced tubular cell death, suggesting a protective role of HIF-1α in DN. Collectively, these findings may unveil a novel miR-122-5p/FIH-1/HIF-1α pathway which can attenuate the DN progression.     

Time course of the antiproteinuric and antihypertensive effect of losartan in diabetic nephropathy.

BACKGROUND: Blockade of the renin-angiotensin system is the primary target in the treatment of diabetic kidney disease. Angiotensin II subtype 1 (AT1) receptor antagonists reduce albuminuria and lower blood pressure, but the initial time course of these effects after initiation of treatment is unknown. We evaluated the time course of the antihypertensive and antialbuminuric effect after initiation of AT1 receptor blockade by losartan in diabetic nephropathy. METHODS: Ten hypertensive type 1 diabetic patients with diabetic nephropathy were included in the study. After a washout period of 4 weeks, patients received losartan 100 mg once daily for 28 days. Every morning, one urine sample was collected for daily determination of albumin/creatinine ratio. Twenty-four hour blood pressure (Takeda TM2420), plasma renin and plasma creatinine were measured at baseline and days 7, 14 and 28. RESULTS: Baseline levels of urinary albumin/creatinine ratio and 24 h mean arterial blood pressure were 676 (402-1136) mg/g (geometric mean and 95% CI, respectively) and 100+/-3 mmHg (mean +/- SEM). Albumin/creatinine ratio was significantly reduced after 7 days of treatment by 29% (15-41) (95% CI) without significant further reductions during the 28 day study period (P<0.01 vs baseline). Mean arterial blood pressure was significantly lowered by 7 mmHg after 7 days of treatment and remained unchanged throughout the study (P<0.01 vs baseline). Plasma renin was significantly increased from baseline after initiation of losartan treatment and stabilized after 7 days (P<0.01). We found no changes in plasma creatinine during the study. CONCLUSIONS: The initial time course of the reduction in arterial blood pressure and albuminuria are concordant, which suggests that systemic and renal haemodynamic mechanisms are of primary importance in the reduction of albuminuria.     

Polymorphism of the aldosterone synthase gene is not associated with progression of diabetic nephropathy, but associated with hypertension in type 2 diabetic patients

Aim: Inhibition of aldosterone system is beneficial in diabetic nephropathy, and aldosterone synthesis is regulated at the gene-encoding aldosterone synthase (CYP11B2). Considering the role of aldosterone in diabetic nephropathy, genetic polymorphism of this gene may contribute to the development and progression of diabetic nephropathy. In this study, we investigated whether it is associated with diabetic nephropathy in type 2 diabetic patients. Methods: 197 type 2 diabetic patients and 71 healthy controls were enrolled. The study subjects were divided into four groups: healthy controls with normoalbuminuria (n = 71), normoalbuminuric diabetic group (n = 71), microalbuminuric diabetic group (n = 51) and overt proteinuria group (n = 51). Polymorphism of aldosterone synthase gene was determined using standard PCR technique. Results: Higher frequency of TT genotype and T allele in steroidogenic factor-1 (SF-1) binding site and wild type (WT) in intronic conversion (IC) in CYP11B2 was observed in diabetic patients than controls. However, there was no significant difference in SF-1 and IC genotype among diabetic patients according to the state of diabetic nephropathy. Subgroup analysis based on SF-1 polymorphism demonstrated that TT genotype is associated with higher systolic and diastolic blood pressure and higher plasma aldosterone level. In addition, WT in IC genotype showed a significantly higher urinary albumin excretion rate. Plasma aldosterone level was significantly related with systolic blood pressure. Conclusion: Our study suggests that aldosterone synthase gene polymorphism is not associated with progression of diabetic nephropathy, but it may contribute to the development of hypertension associated with increased aldosterone secretion in type 2 diabetic patients.     

PC-1 amino acid variant (K121Q) has no impact on progression of diabetic nephropathy in type 1 diabetic patients.

BACKGROUND: Recently, an amino acid variant (K121Q) in the glycoprotein PC-1 (Q allele) has been associated with faster progression of diabetic nephropathy, as estimated by calculated creatinine clearance. We tested the impact of the PC-1 (K121Q) variant on loss of glomerular filtration rate (GFR) measured by the [(51)Cr]EDTA plasma clearance technique. METHODS: We performed an observational follow-up study of 295 (182 males) type 1 patients with diabetic nephropathy [mean age 37 (SE 0.7) years, mean duration of diabetes 23 (SE 0.5) years]. All patients were followed for at least 3 years, median 8 years (range 3-17), with at least three measurements of GFR using [(51)Cr]EDTA (median 11 measurements (range 3-32)). Two hundred and seventeen patients had the KK genotype and 78 carried the Q allele (71 KQ and 7 QQ). RESULTS: Patients carrying the Q allele had a mean rate of decline in GFR during follow-up of 3.6 ml/min per year (SE 0.4) compared with 4.0 ml/min per year (SE 0.3) in patients with the KK genotype. Other risk factors for progression of diabetic nephropathy were similar in Q carriers and KK carriers. When dividing patients in tertiles based on rate of decline in GFR, we found no difference in distribution of K121Q genotypes. No difference in the number of patients who died or reached end-stage renal disease during follow-up according to K121Q genotype were found. A multiple linear regression analysis revealed that albuminuria, mean arterial blood pressure, haemoglobin A(1C) and serum cholesterol during follow-up predicted a steeper decline in GFR [R(2) (adjusted)=0.27], whereas the PC-1 genotype did not contribute. CONCLUSIONS: Our study did not reveal an association between the PC-1 amino acid variant K121Q and progression of diabetic nephropathy.