scholarly journals Salvianolic Acid A Protects Against Diabetic Nephropathy through Ameliorating Glomerular Endothelial Dysfunction via Inhibiting AGE-RAGE Signaling

2017 ◽  
Vol 44 (6) ◽  
pp. 2378-2394 ◽  
Author(s):  
Biyu Hou ◽  
Guifen Qiang ◽  
Yuerong Zhao ◽  
Xiuying Yang ◽  
Xi Chen ◽  
...  

Background/Aims: Glomerular endothelium dysfunction leads to the progression of renal architectonic and functional abnormalities in early-stage diabetic nephropathy (DN). Advanced glycation end products (AGEs) and receptor for AGEs (RAGE) are proved to play important roles in diabetic nephropathy. This study investigated the role of Salvianolic acid A (SalA) on early-stage DN and its possible underlying mechanism. Methods: In vitro AGEs formation and breaking rate were measured to illustrate the effect of SalA on AGEs. Type 2 diabetic nephropathy rats were induced by high-fat diet and low-dose streptozocin (STZ). After eight-week treatment with SalA 1 mg/kg/day, 24h-urine protein, creatinine clearance was tested and renal structural injury was assessed by PAS and PASM staining. Primary glomerular endothelial cell permeability was evaluated after exposed to AGEs. AGEs-induced RhoA/ROCK and subsequently activated disarrange of cytoskeleton were assessed by western blot and immunofluorescence. Results: Biochemical assay and histological examination demonstrated that SalA markedly reduced endothelium loss and glomerular hyperfiltration, suppressed glomerular hypertrophy and mesangial matrix expansion, eventually reduced urinary albumin and ameliorated renal function. Further investigation suggested that SalA exerted its renoprotective effects through inhibiting AGE-RAGE signaling. It not only inhibited formation of AGEs and increased its breaking in vitro, but also reduced AGEs accumulation in vivo and downregulated RAGE expression. SalA restored glomerular endothelial permeability through suppressing AGEs-induced rearrangement of actin cytoskeleton via AGE-RAGE-RhoA/ ROCK pathway. Moreover, SalA attenuated oxidative stress induced by AGEs, subsequently alleviated inflammation and restored the disturbed autophagy in glomerular endothelial cell and diabetic rats via AGE-RAGE-Nox4 axis. Conclusion: Our study indicated that SalA restored glomerular endothelial function and alleviated renal structural deterioration through inhibiting AGE-RAGE, thus effectively ameliorated early-stage diabetic nephropathy. SalA might be a promising therapeutic agent for the treatment of diabetic nephropathy.

2018 ◽  
Vol 49 (6) ◽  
pp. 2320-2332 ◽  
Author(s):  
Guo Zu ◽  
Tingting Zhou ◽  
Ningwei Che ◽  
Xiangwen Zhang

Background/Aims: Ischemia-reperfusion (I/R) adversely affects the intestinal mucosa. The major mechanisms of I/R are the generation of reactive oxygen species (ROS) and apoptosis. Salvianolic acid A (SalA) is suggested to be an effective antioxidative and antiapoptotic agent in numerous pathological injuries. The present study investigated the protective role of SalA in I/R of the intestine. Methods: Adult male Sprague-Dawley rats were subjected to intestinal I/R injury in vivo. In vitro experiments were performed in IEC-6 cells subjected to hypoxia/ reoxygenation (H/R) stimulation to simulate intestinal I/R. TNF-α, IL-1β, and IL-6 levels were measured using enzyme-linked immunosorbent assay. Malondialdehyde and myeloperoxidase and glutathione peroxidase levels were measured using biochemical analysis. Apoptosis was measured by terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling staining or flow cytometry in vivo and in vitro. The level of reactive oxygen species (ROS) was measured by dichlorodihydrofluorescin diacetate (DCFH-DA) staining. Western blotting was performed to determine the expression of heme oxygenase-1 (HO-1), Nrf2 and proteins associated with apoptosis. The mRNA expressions of Nrf2 and HO-1 were detected by quantitative real-time polymerase chain reaction in vivo and in vitro. Results: Malondialdehyde level and myeloperoxidase and glutathione peroxidase, TNF-α, IL-1β, and IL-6 levels group in intestinal tissue decreased significantly in the SalA pretreatment groups compared to the I/R group. SalA markedly abolished intestinal injury compared to the I/R group. SalA significantly attenuated apoptosis and increased Nrf2/HO-1 expression in vivo and in vitro. However, Nrf2 siRNA treatment partially abrogated the above mentioned effects of SalA in H/R-induced ROS and apoptosis in IEC-6 cells. Conclusion: The present study demonstrated that SalA ameliorated oxidation, inhibited the release of pro-inflammatory cytokines and alleviated apoptosis in I/R-induced injury and that these protective effects may partially occur via regulation of the Nrf2/ HO-1 pathways.


2017 ◽  
Vol 20 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Elena Sergeevna Kamyshova ◽  
Irina Nikolaevna Bobkova ◽  
Irina Mikhailovna Kutyrina

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus associated with the progressive deterioration of renal function. Although microalbuminuria is considered as a gold standard for DN diagnosis, it has limited predictive powers and specificity as a diagnostic tool for the early stage of DN. Therefore, new biomarkers are required for the early detection of DN. Studies using in vitro and in vivo models of DN have revealed an important role of microRNAs (miRNAs), short non-coding RNAs that modulate physiological and pathological processes by inhibiting target gene expression, in DN development. Recent studies have shown that the dysregulation of miRNAs, which is associated with the key features of DN, such as the mesangial expansion and accumulation of extracellular matrix proteins, is related to fibrosis and glomerular dysfunction. Thus, the up- and downregulation of miRNA expression in the renal tissue or biological fluids, including urine, may represent new biomarkers for the diagnosis and monitoring of DN progression. In this review, we highlight the significance of miRNAs as biomarkers for the early detection of DN and emphasise their potential role as a therapeutic target.


2014 ◽  
Vol 306 (11) ◽  
pp. F1335-F1347 ◽  
Author(s):  
Keisuke Omote ◽  
Tomohito Gohda ◽  
Maki Murakoshi ◽  
Yu Sasaki ◽  
Saiko Kazuno ◽  
...  

Chronic inflammation promotes the progression of diabetic nephropathy (DN). However, the role of TNF-α remains unclear. The objectives of the present study were to examine whether TNF-α inhibition with a soluble TNF receptor (TNFR)2 fusion protein, i.e., etanercept (ETN), improves the early stage of DN in the type 2 diabetic model of the KK-Ay mouse and to also investigate which TNF pathway, TNFR1 or TNFR2, is predominantly involved in the progression of this disease. ETN was injected intraperitoneally into mice for 8 wk. Renal damage was evaluated by immunohistochemistry, Western blot analysis, and/or real-time PCR. In vitro, mouse tubular proximal cells were stimulated by TNF-α and/or high glucose (HG) and treated with ETN. ETN dramatically improved not only albuminuria but also glycemic control. Renal mRNA and/or protein levels of TNFR2, but not TNF-α and TNFR1, in ETN-treated KK-Ay mice were significantly decreased compared with untreated KK-Ay mice. mRNA levels of ICAM-1, VCAM-1, and monocyte chemoattractant protein-1 and the number of F4/80-positive cells were all decreased after treatment. Numbers of cleaved caspase-3- and TUNEL-positive cells in untreated mice were very few and were not different from ETN-treated mice. In vitro, stimulation with TNF-α or HG markedly increased both mRNA levels of TNFRs, unlike in the in vivo case. Furthermore, ETN partly recovered TNF-α-induced but not HG-induced TNFR mRNA levels. In conclusion, it appears that ETN may improve the progression of the early stage of DN predominantly through inhibition of the anti-inflammatory action of the TNF-α-TNFR2 pathway.


2021 ◽  
Author(s):  
Junxiu Zhang ◽  
Jingyi Zhu ◽  
Lingzhou Zhao ◽  
Ke Mao ◽  
Qing Gu ◽  
...  

Abstract Background: The development of alternative anti-angiogenesis therapy for choroidal neovascularization (CNV) remains a great challenge. Nanoparticle systems have emerged as a new form of drug delivery in ocular diseases. Here, we report the construction and characterization of arginine-glycine-aspartic acid (RGD)-conjugated polyethyleneimine (PEI) as a vehicle to load antioxidant salvianolic acid A (SAA) for targeted anti-angiogenesis therapy of CNV. In this study, PEI was consecutively modified with polyethylene glycol (PEG) conjugated RGD segments, 3-(4’-hydroxyphenyl) propionic acid-Osu (HPAO), and fluorescein isothiocyanate (FI), followed by acetylation of the remaining PEI surface amines to generate the multifunctional PEI vehicle PEI.NHAc-FI-HPAO-(PEG-RGD) (for short, RGD-PEI). The formed RGD-PEI was utilized as an effective vehicle platform to load SAA. Results: We showed that RGD-PEI/SAA complexes displayed desirable water dispersibility, low cytotoxicity, and sustainable release of SAA under different pH conditions. It could be specifically taken up by ɑvβ5 integrin receptors expressing retinal pigment epithelium (RPE) cells in vitro and selectively accumulated in CNV lesions in vivo. Moreover, the complexes displayed specific therapeutic efficacy in a mouse model of laser induced CNV, and the slow elimination of the complexes in the vitreous cavity was verified by SPECT imaging after 131I radiolabeling. The histological examinations further confimed the biocompatibility of RGD-PEI/SAA.Conclusions: The results suggest that the designed RGD-PEI/SAA complexes may be a potential alternative anti-angiogenesis therapy for posterior ocular neovascular diseases.


1999 ◽  
Vol 55 (6) ◽  
pp. 2236-2249 ◽  
Author(s):  
Christian P.M. Hugo ◽  
Raimund P. Pichler ◽  
Eckhard Schulze-Lohoff ◽  
Felicitas Pröls ◽  
Stephen Adler ◽  
...  

2019 ◽  
Vol 67 (44) ◽  
pp. 12199-12207
Author(s):  
Fuqiong Zhou ◽  
Linxin Teng ◽  
Yu Liu ◽  
Yanxia Ma ◽  
Weiping Chen ◽  
...  

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 543 ◽  
Author(s):  
Ruiying Wang ◽  
Jingyi Zhang ◽  
Shan Wang ◽  
Min Wang ◽  
Tianyuan Ye ◽  
...  

Arsenic trioxide (ATO) has been verified as a breakthrough with respect to the management of acute promyelocytic leukemia (APL) in recent decades but associated with some serious adverse phenomena, particularly cardiac functional abnormalities. Salvianolic acid A (Sal A) is a major effective component in treating ATO-induced cardiotoxicity. Therefore, the objective of our study was to assess whether Sal A had protective effects by the regulation of calcium homeostasis and endoplasmic reticulum (ER) stress. For the in vivo study, BALB/c mice were treated with ATO and/or Sal A via daily tail vein injections for two weeks. For the in vitro study, we detected the effects of ATO and/or Sal A in real time using adult rat ventricular myocytes (ARVMs) and an IonOptix MyoCam system. Our results showed that Sal A pretreatment alleviated cardiac dysfunction and Ca2+ overload induced by ATO in vivo and vitro. Moreover, Sal A increased sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) activity and expression, alleviated [Ca2+]ER depletion, and decreased ER stress-related protein expression. Sal A protects the heart from ATO-induced injury and its administration correlates with the modulation of SERCA, the recovery of Ca2+ homeostasis, and the down-regulation of ER stress-mediated apoptosis.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Shaojiang Tian ◽  
Junming Tang ◽  
Huihui Liu ◽  
Liping Wang ◽  
Jianming Shen ◽  
...  

There is growing evidence suggesting that glomerular endothelial cell proliferation and angiogenesis may be responsible for the pathophysiological events in the early stage of diabetic nephropathy. This study was designed to investigate the factors related to glomerular endothelial cell proliferation and glomerular angiogenesis and assess the effect of propyl gallate on preventing these disorders in diabetic rats. We found that glomerular hypertrophy, glomerular mesangial matrix expansion, and albuminuria were significantly increased in DN rats. CD31+ endothelial cells significantly increased in glomerulus of diabetic rats. Double immunofluorescence staining showed some structurally defective vasculus tubes in glomerulus. Real-time PCR and western blot demonstrated the glomerular eNOS expression remained at the same level, while remarkable decreased NO productions and suppressed eNOS activities were observed in diabetic rats. Treatment with propyl gallate improved glomerular pathological changes, reduced endothelial cell proliferation, decreased albuminuria, and restored eNOS activity, but did not alter eNOS expression. These data suggest that endothelial cell proliferation and immature angiogenesis may be the contributors to progression of DN. Propyl gallate is a potential novel therapeutic agent on prevention of diabetic nephropathy.


2021 ◽  
Author(s):  
Fengzhen Wang ◽  
Dong Sun ◽  
Haihan Sun ◽  
Bangjie Zuo ◽  
Kun Shi ◽  
...  

Abstract The aim of the study was to compare the role of metformin on tubulointerstitial fibrosis (TIF) in different stages of diabetic nephropathy (DN) in vivo and evaluate its mechanism in high-glucose-treated Renal tubular epithelial cells (RTECs) in vitro. Sprague-Dawley (SD) rats were used to establish model of DN, then the changes of biochemical indicators and body weight were measured. The degree of renal fibrosis was quantified via histological analysis, immunohistochemistry, and immunoblot. The underlying relationship between autophagy and DN was analyzed and the cellular regulatory mechanism of metformin on epithelial-to-mesenchymal transition (EMT) was detected. Metformin markedly improved renal function and showed histological restoration of renal tissues especially in the early stage of DN, with a significant improvement of autophagy and a low expression of fibrotic biomarkers (Fibronectin and Collagen I) in renal tissue. RTECs under hyperglycemic conditions exhibited inactivation of p-AMPK and activation of EMT. But the promotion of AMPK activated by metformin significantly improved renal autophagic function, inhibited the EMT of RTECs, attenuated TIF, so as to effectively prevent or delay the course of DN. This evidence provided theoretical and experimental basis for the following research on the potential clinical usefulness of metformin for the treatment of diabetic TIF.


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