Attenuation of diabetic nephropathy by Chaihuang-Yishen granule through anti-inflammatory mechanism in streptozotocin-induced rat model of diabetics

Ethnopharmacological relevance

Traditional Chinese medical herbs have been used in China for a long time to treat different diseases. Based on traditional Chinese medicine (TCM) principle, Chaihuang-Yishen granule (CHYS) was developed and has been employed clinically to treat chronic kidney disease including diabetic nephropathy (DN). The present study was designed to investigate its mechanism of action in treatment of DN.

Materials and methods

Diabetic rats were established by having a right uninephrectomy plus a single intraperitoneal injection of STZ. Rats were divided into four groups of sham, diabetes, diabetes with CHYS and diabetes with fosinopril. CHYS and fosinopril were given to rats by gavage for 20 weeks. Samples from blood, urine and kidney were collected for biochemical, histological, immunohistochemical and molecular analyses.

Results

Rats treated with CHYS showed reduced 24 h urinary protein excretion, decreased serum TC and TG levels, but CHYS treatment did not affect blood glucose level. Glomerular mesangial expansion and tubulointerstitial fibrosis in diabetic rats were significantly alleviated by CHYS treatment. Moreover, CHYS administration markedly reduced mRNA levels of NF-κB p65 and TGF-β1, as well as decreased protein levels of NF-κB p65, MCP-1, TNF-α and TGF-β1 in the kidney of diabetic rats.

Conclusions

CHYS ameliorates renal injury in diabetic rats through reduction of inflammatory cytokines and their intracellular signaling.     

Podocytic degeneration and regeneration in puromycin aminonucleoside nephropathy in the rat

In various types of chronic glomerulonephritis, proliferation of mesangial and endothelial cells is often seen together with extracellular matrix accumulation. In contrast, the proliferation of visceral glomerular epithelial cells (podocytes) has not been detected in any disease in which these cells are the principal target of injury. To examine whether proliferation of podocytes occurs, puromycin aminonucleoside nephropathy was induced in Wistar rats by intraperitoneal injection of puromycin aminonucleoside (15mg/100g of bodyweight). In this nephropathy model of nephrotic syndrome with minimal change, the main lesions consisted of vacuolation and flattened foot processes of podocytes, which are the primary target of puromycin aminonucleoside. Urine protein excretion and proliferating cell nuclear antigen (PCNA) positive cells were examined. The PCNA+ podocytic count reached its maximum on day 3, indicating that the most marked podocytic proliferation occurs just after the injection of PAN. Twenty-four hour urinary excretion in this nephropathy model supported the hypothesis that mitosis of podocytes occurs in association with recovery on day 13.     

IQGAP1在调节足细胞细胞骨架重组中的作用

目的:研究支架蛋白IQGAP1在足细胞骨架重组中的作用。方法:用嘌呤霉素(PAN)刺激小鼠足细胞,实时定量PCR检测IQGAP1mRNA的表达,免疫印迹法检测足细胞IQGAP1蛋白的表达,激光共聚焦显微镜观察足细胞骨架F-actin分布,F-actin肌动蛋白评分系统(CFS)分析骨架重组;IQGAP1siRNA和IQGAP1质粒转染足细胞,分别观察下调和上调足细胞IQGAP1表达对嘌呤霉素诱导足细胞细胞骨架重组的改变。结果:嘌呤霉素刺激足细胞后IQGAP1mRNA和蛋白表达下调(P<0.05),足细胞F-actin分布发生明显重组;转染IQGAP1siRNA,嘌呤霉素刺激足细胞F-actin重组进一步加重;转染IQGAP1质粒,嘌呤霉素刺激足细胞F-actin重组减轻。结论:IQGAP1可能参与嘌呤霉素诱导的足细胞细胞骨架重组。     

MiR-122稳定转染细胞系的建立及其脂代谢特征

目的:利用稳定表达人miR-122前体的表达载体,转染低表达miR-122的人肝癌细胞系HepG2细胞,获得过量表达miR-122的稳定转染细胞系,探讨miR-122对肝脏细胞脂代谢的影响及其机制。方法:对已构建完成的表达质粒pEZX-hsa-mir-122和对照质粒pEZX-mir-control进行酶切鉴定,对酶切正确的克隆进行DNA测序,测序正确的克隆应用脂质体试剂转染,绿色荧光蛋白表达监测转染效率,应用嘌呤霉素筛选稳定转染细胞系,实时定量PCR在RNA水平鉴定miR-122的表达,蛋白质印迹法从靶分子水平验证miR-122的抑制功能,尼罗红染色观察细胞内脂质。结果:pEZX-hsa-mir-122质粒成功转染HepG2细胞,质粒携带的miR-122前体序列整合到细胞基因组中,获得过量表达miR-122的HepG2细胞株,细胞内成熟体miR-122可抑制靶基因的翻译,细胞内脂质明显增加。结论:人miR-122前体序列可整合在HepG2细胞基因组中,过量表达miR-122的HepG2细胞出现脂质代谢异常。     

Renoprotective potential of Macrothelypteris torresiana via ameliorating oxidative stress and proinflammatory cytokines

Ethnopharmacological relevance

Macrothelypteris torresiana is traditionally used in Chinese folk medicine for the treatment of edema for patients suffering from kidney/bladder problems due to its satisfactory therapeutic effectiveness.

Aim of the study

The aim of this study was to investigate the renoprotective nature of the total polyphenols fraction from Macrothelypteris torresiana (PMT).

Materials and methods

The biochemical criterions of plasma and kidney tissues were evaluated to study the effects of PMT on puromycin aminonucleoside-induced chronic nephrotic syndrome (NS) in hyperlipidemic mice.

Results

In this study, the NS and hyperlipidemia were ameliorated after 9 weeks administration of PMT. Besides, PMT was able to modulate the level of renal oxidative stress and vascular endothelial growth factor-nitric oxide (VEGF-NO) pathway.

Conclusions

It represented a potential resource of PMT for the treatment of NS involved in metabolic syndrome.     

雷公藤甲素干预足细胞病变的体外观察

目的：雷公藤甲素对Heymann肾炎和嘌呤霉素肾病大鼠的疗效及其对足细胞病变的影响提示，雷公藤甲素有可能直接作用于足细胞，从而改善其病变状况。本研究借助小鼠足细胞系，体外观察了雷公藤甲素对足细胞损伤的保护和修复作用，并对其作用机制进行了研究。方法：体外采用氨基核苷嘌呤霉素（puromycin aminonucleoside，PAN）致足细胞损伤模型。观察雷公藤甲素对足细胞损伤的保护作用研究中，雷公藤甲素与足细胞预孵育30min后，再加入含PAN的培养基，继续作用24h；观察雷公藤甲素对足细胞损伤的修复作用研究中，PAN作用足细胞24h，造成足细胞明显损伤后，再加入含或不含雷公藤甲素的培养基，继续培养3天。免疫荧光法和流式细胞仪分析足细胞骨架相关蛋白F-actin和Synaptopodin的变化，并进一步观察了细胞内调节骨架装配的Rho／ROCK信号通路的活性，即采用Western Blot检测ROCK-Ⅰ底物——肌球蛋白磷酸酶结合亚单位（MBS）磷酸化水平，以及Rho／ROCK信号通路选择性阻断剂Y-27632对雷公藤甲素作用的影响。同时采用免疫荧光法和流式细胞仪分析足细胞裂孔膜相关分子Nephrin和Podocin在足细胞的分布及表达量的变化。结果：正常分化足细胞F—actin呈丝状结构，密度大，丝强劲有力，沿细胞极性分布；Synaptopodin呈颗粒状沿细胞骨架分布。裂孔膜蛋白Nephrin沿足细胞膜和细胞骨架分布，Podocin呈线状均匀分布于胞浆内，PAN作用24h后，细胞足突回缩，F—actin几乎完全解聚，Synaptopodin表达消失。Nephrin和Podocin表达减弱，正常丝状结构消失。而经过雷公藤甲素的预处理，PAN诱导的足细胞损伤明显减弱，足细胞未表现出上述骨架结构的改变，Synaptopodin表达没有明显减弱。同时我们的结果显示，在PAN造成足细胞明显损伤后再加入雷公藤甲素，足细胞损伤能够得到一定修复，细胞内重新出现极性分布的微丝，同时，Synaptopodin的表达也得以修复。Rho／ROCK信号通路研究显示，100μg／ml PAN明显降低Rho／ROCK通路活性。雷公藤甲素能有效遏制MBS磷酸化水平的降低，维持足细胞Rho／ROCK通路的活性状态。Rho／ROCK信号通路选择性抑制剂Y-27632可阻断雷公藤对足细胞骨架结构的保护作用。此外，对裂孔膜蛋白Nephrin，Podocin的研究表明，不论是在预防组和治疗组，PAN对Nephrin和Podocin的损伤可在一定程度上被雷公藤甲素预防和修复。结论：雷公藤甲素可稳定足细胞的细胞骨架，拮抗PAN对足细胞的损伤。在足细胞损伤已经发生后，雷公藤甲素可逆转足细胞的损伤，修复足细胞骨架结构和相关分子的表达。雷公藤甲素的上述作用与细胞内Rho／ROCK信号通路密切相关。雷公藤甲素对足细胞的影响可能是其降低肾小球肾炎患者尿蛋白的重要机制之一。     

免疫核糖核酸体外介导白细胞粘附抑制反应中转录和翻译的意义

以[~3H]Leu-LAI为指标,观察放线菌素D和嘌呤霉素对小鼠S_(180)腹水瘤细胞特异性iRNA体外转移细胞免疫活性的影响。结果表明,正常小鼠脾淋巴细胞经iRNA致敏后,用放线菌素D阻断其转录,或用嘌呤霉素阻断其翻译,并不能使该淋巴细胞失去对相应抗原产生LAI反应的能力;若先将淋巴细胞分别与放线菌素D或嘌呤霉素温育,使转录或翻译被阻断后再用iRNA作用时,见对相应抗原无LAI反应。这些结果说明iRNA体外介导LAI反应的过程,必须有受体细胞的转录或翻译功能参与;同时也提示临床使用iRNA治疗恶性肿瘤时,先行治疗方法若能抑制淋巴细胞的转录或翻译,则有可能降低iRNA的疗效,