Inhibition of Akt/mTOR/p70S6K Signaling Activity With Huangkui Capsule Alleviates the Early Glomerular Pathological Changes in Diabetic Nephropathy

Chinese herbal medicine for the treatment of diabetic nephropathy: From clinical evidence to potential mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic nephropathy (DN) is a typical chronic microvascular complication of diabetes, characterized by proteinuria and a gradual decline in renal function. At present, there are limited clinical interventions aimed at preventing the progression of DN to end-stage renal disease (ESRD). However, Chinese herbal medicine presents a distinct therapeutic approach that can be effectively combined with conventional Western medicine treatments to safeguard renal function. This combination holds considerable practical implications for the treatment of DN.

AIM OF THE STUDY

This review covers commonly used Chinese herbal remedies and decoctions applicable to various types of DN, and we summarize the role played by their active ingredients in the treatment of DN and their mechanisms, which includes how they might improve inflammation and metabolic abnormalities to provide new ideas to cope with the development of DN.

MATERIALS AND METHODS

With the keywords "diabetic nephropathy," "Chinese herbal medicine," "clinical effectiveness," and "bioactive components," we conducted an extensive literature search of several databases, including PubMed, Web of Science, CNKI, and Wanfang database, to discover studies on herbal formulas that were effective in slowing the progression of DN. The names of the plants covered in the review have been checked at MPNS (http://mpns.kew.org).

RESULTS

This review demonstrates the superior total clinical effective rate of combining Chinese herbal medicines with Western medicines over the use of Western medicines alone, as evidenced by summarizing the results of several clinical trials. Furthermore, the review highlights the nephroprotective effects of seven frequently used herbs exerting beneficial effects such as podocyte repair, anti-fibrosis of renal tissues, and regulation of glucose and lipid metabolism through multiple signaling pathways in the treatment of DN.

CONCLUSIONS

The potential of herbs in treating DN is evident from their excellent effectiveness and the ability of different herbs to target various symptoms of the condition. However, limitations arise from the deficiencies in interfacing with objective bioindicators, which hinder the integration of herbal therapies into modern medical practice. Further research is warranted to address these limitations and enhance the compatibility of herbal therapies with contemporary medical standards.

Inhibition of ferroptosis of renal tubular cells with total flavones of Abelmoschus manihot alleviates diabetic tubulopathy

Ferroptosis-related renal tubular lesions play important roles in diabetic kidney disease (DKD) progression, and these pathophysiological responses are collectively described as diabetic tubulopathy (DT), which lacks an effective treatment. Total flavones from Abelmoschus manihot (TFA), a natural extract that extensively used in patients with chronic kidney disease, has been used for treatment of renal tubular injury in DKD; however, whether TFA alleviates DT and its potential mechanisms remain unclear. Hence, we investigated the effects of TFA, compared to dapagliflozin, in DT management both in vivo and in vitro, using a DKD rat model and the NRK-52 E cells. Following modeling, the DKD rats received TFA, dapagliflozin, or vehicle for 6 weeks. For the in vitro research, the NRK-52 E cells were exposed to advanced glycation end products (AGEs) plus ferrostatin-1 (Fer-1), dapagliflozin, or TFA. Changes in biochemical parameters and renal tubular injury were analyzed in vivo, while changes in ferroptosis of renal tubular cells and the ferroptosis-related proteins expression were analyzed both in vivo and in vitro. We found that TFA and dapagliflozin improved biochemical parameters, renal tubular injury, and ferroptosis in the DKD rats. Moreover, TFA and dapagliflozin inhibited ferroptosis by ameliorating iron deposition, lipid peroxidation capacity, and ferroptosis-related proteins expression in vitro, which was similar to the effects of Fer-1. Collectively, this study demonstrated that TFA treated DT in a manner similar to dapagliflozin by inhibiting ferroptosis of renal tubular cells via improving iron deposition and antioxidant capacity. Our findings provide new pharmacological evidence for TFA application in DT treatment.

The pharmacological mechanism of Abelmoschus manihot in the treatment of chronic kidney disease

Abelmoschus manihot (A.manihot) is a herbaceous flowering medicinal plant and flavonoids are its main pharmacological active ingredients. A.manihot is listed in the 2020 edition of the Chinese Pharmacopoeia for the treatment of chronic kidney disease (CKD). A.manihot significantly reduces proteinuria in CKD, and the effectiveness and safety of A.manihot in the treatment including primary glomerulonephropathy and diabetic kidney disease (DKD) have been proved by several randomized controlled trials (RCT). Emerging pharmacological studies have explored the potential active small molecules and the underlying mechanisms in A.manihot. The active constituents of A.manihot are mainly seven flavonoids, including hibifolin, hyperoside, isoquercetin, rutin, quercetin, myricetin, and quercetin-3-O-robinobioside. The mechanisms of action mainly include alleviating renal fibrosis, reducing the inflammatory response and decreasing the apoptosis of podocytes. In this review, we summarize the updated information of active components and molecular mechanisms of A.manihot on chronic kidney disease.

Oral proprietary Chinese medicine for lupus nephritis: A bayesian network meta-analysis

Objective

To analyze the efficacy and safety of proprietary Chinese medicines for the treatment of Lupus Nephritis (LN) based on the reticulated meta analysis. The study aim to provide evidence-based evidence for the clinical treatment of LN.

Methods

The studies related to the randomized controlled studies (RCTs) on the treatment of LN with oral proprietary Chinese medicines were obtained from China National Knowledge Infrastructure (CNKI), Database for Chinese Technical Periodicals (VIP), SinoMed, Wanfang, PubMed, Web of Science, Embase and Cochrane Library databases since its inception-August 2022. Cochrane tools were used for risk bias assessment, Stata 13.0 and ADDIS 1.16.5 software were used for net evidence analysis.Results.1) 41 RCTs with 3124 L N patients were included, involving 9 types of proprietary Chinese medicines.2) The meta-analysis showed that in terms of efficacy, the top 3 Chinese patent medicine interventions were Xin Gan Bao Capsule (XGB) +western medicines (WM), Huang Kui Capsule (HK) + WM, Kun Xian Capsule (KX) + WM; in terms of reducing adverse event rate, the top 3 Chinese patent medicine interventions were Yi Shen Hua Shi Granules (YSHS) + WM, Jin Shui Bao Capsule (JSB) + WM, HK + WM; in terms of reducing 24 h urine protein, the top 3 Chinese patent medicine interventions were XGB + WM, YSHS + WM, Bai Ling Capsule (BL) + WM; in terms of reducing blood creatinine (Cr), the top 3 Chinese patent medicine interventions were Yi Shen Granules (YS) + WM, JSB + WM, KX + WM; in terms of reducing urea nitrogen (BUN), the top 3 Chinese patent medicine interventions were Shen Kang Capsule (SK) + WM, HK + WM, JSB + WM; in terms of reducing systemic lupus erythematosus disease activity index (SLEDAI) scores, the top 3 Chinese patent medicine interventions were JSB + WM, BL + WM, YSHS + WM; in terms of improving complement C3, the top 3 Chinese patent medicine interventions were HK + WM, XGB + WM, BL + WM; in terms of improving complement C4, the top 3 Chinese patent medicine interventions were KX + WM, YSHS + WM, BL + WM.

Conclusion

Xin Gan Bao Capsule has a good efficacy in improving efficiency and the level of complement C3, lowering 24 h urine protein. Jin Shui Bao Capsule and Huang Kui Capsule have a good efficacy in treating LN. However, more multicentre, large sample and high quality RCTs are needed for validation the results.

Identification of PDK4 as Hub Gene for Diabetic Nephropathy Using Co-Expression Network Analysis

INTRODUCTION

Diabetic nephropathy (DN) is related to type 1 and type 2 diabetes. They are the leading cause of end-stage renal disease, but the underling specific pathogenesis of DN is not yet clear. Our study was conducted to explore how DN changed the transcriptome profiles in the kidney.

METHODS

The gene expression profile of microdissected glomeruli of 41 type 2 DN patients and 20 healthy controls were included. The sample dataset GSE96804 was obtained from the GEO database. Differentially expressed genes (DEGs) were analyzed in R with the limma package and the important modules were found by weighted gene co-expression network analysis (WGCNA) clustering. The modules were then analyzed based on Gene Ontology (GO) gene set enrichment analysis, and the hub genes were found out. We next validated the hub gene, PDK4, in a cell model of DN. We also constructed the PDK4-related PPI network to investigate the correlation between PDK4 expression and other genes.

RESULTS

Heatmap and volcano map were drawn to illustrate the mRNA expression profile of 1,204 DEGs in both samples of DN patients and the control group. Using WGCNA, we selected the blue module in which genes showed the strongest correlation with the phenotype and the smallest p value. We also identified PDK4 as a hub gene. PDK4 expression was upregulated in human diabetic kidney tissue. Moreover, PDK4 was speculated to play a role in glomerular basement membrane development and kidney development according to the enrichment of functions and signaling pathways. Furthermore, PDK4 and two key genes GSTA2 and G6PC protein expression were verified highly expressed in the cell model of DN.

CONCLUSION

During the pathogenesis of DN, many genes may change expression in a coordinated manner. The discovery of PDK4 as key gene using WGCNA is of great significance for the development of new treatment strategies to block the development of DN.

Yishen Huashi granule modulated lipid metabolism in diabetic nephropathy via PI3K/AKT/mTOR signaling pathways

Aim

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease worldwide. Although etiology for DN is complex and still needs to be fully understood, lipid metabolism disorder is found to play a role in it. Previously, we found Yishen Huashi (YSHS) granule could inhibit diabetic damage and reduce level of microalbuminuria (mALB) in DN animals. To explore its role and mechanism in lipid metabolism under DN settings, this study was designed.

Materials and methods

DN rats were induced by streptozotocin (STZ), HepG₂ and CaCO₂ cells were applied for in vitro study. Hematoxylin-Eosin (HE), periodic acid-Schiff (PAS) staining, and Transmission Electron Microscopy (TEM) were applied for histological observation; 16s Sequencing was used for intestinal microbiota composition analysis; western blotting (WB) and immunofluorescence were carried out for molecular biological study, and enzyme-linked immunosorbent assay (ELISA) was used for lipid determination.

Results

YSHS administration significantly reduced levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL-C), while increased level of high-density lipoprotein (HDL-C); meanwhile, histological changes and steatosis of the liver was ameliorated, integrity of the intestinal barrier was enhanced, and dysbacteriosis within intestinal lumen was ameliorated. Mechanism study found that YSHS modulated mitophagy within hepatocytes and inhibited mTOR/AMPK/PI3K/AKT signaling pathway.

Conclusion

In conclusion, we found in the present study that YSHS administration could ameliorate lipid metabolism disorder in DN animals, and its modulation on intestinal-liver axis played a significant role in it.

Network pharmacology analysis combined with experimental validation to explore the therapeutic mechanism of Schisandra Chinensis Mixture on diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic nephropathy (DN) is one of the most common and serious microvascular complications of Diabetes mellitus (DM). The inflammatory response plays a critical role in DN. Schisandra Chinensis Mixture (SM) has shown promising clinical efficacy in the treatment of DN while the pharmacological mechanisms are still unclear.

AIM OF THE STUDY

In this study, a network pharmacology approach and bioinformatic analysis were adopted to predict the pharmacological mechanisms of SM in DN therapy. Based on the predicted results, molecular docking and in vivo experiments were used for verification.

MATERIALS AND METHODS

In this study, the candidate bioactive ingredients of SM were obtained via Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and supplementing according to the literature. SM putative targets and the verified targets were acquired from TCMSP and SiwssTartgetPrediction Database. DN-related target genes were collected from GeneCards, OMIM, DisGeNET databases, and microarray data analysis. Biological function and pathway analysis were performed to further explore the pharmacological mechanisms of SM in DN therapy. The protein-protein interaction (PPI) network was established to screen the hub gene. The Receiver Operating Characteristic (ROC) analysis and the molecular docking simulations were performed to validate the potential target-drug interactions. The fingerprint spectrum of multi-components of the SM was characterized by UPLC-MS/MS. The signaling pathways associated with inflammation and hub genes were partially validated in SD rats.

RESULTS

A total of 36 bioactive ingredients were contained, and 666 component-related targets were screened from SM, of which 50 intersected with DN targets and were considered potential therapeutic targets. GO analyses revealed that the 50 intersection targets were mainly enriched in the inflammatory response, positive regulation of angiogenesis, and positive regulation of phosphatidylinositol 3-kinase(PI3K) signaling. KEGG analyses indicated that the PI3K-Akt signaling pathway was considered as the most important pathway for SM antagonism to the occurrence and development of DN, with the highest target count enrichment. PPI network results showed that the top 15 protein targets in degree value, VEGFA, JAK2, CSF1R, NOS3, CCR2, CCR5, TLR7, FYN, BTK, LCK, PLAT, NOS2, TEK, MMP1 and MCL1, were identified as hub genes. The results of ROC analysis showed that VEGFA and NOS3 were valuable in the diagnosis of DN. The molecular docking confirmed that the core bioactive ingredients had well-binding affinity for VEGFA and NOS3. The in vivo experiments confirmed that SM significantly inhibited the over-release of inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor receptor (TNF)-α in DN rats, while regulating the PI3K-AKT and VEGFA-NOS3 signaling pathways.

CONCLUSION

This study revealed the multi-component, multi-target and multi-pathway characteristics of SM therapeutic DN. SM inhibited the inflammatory response and improved renal pathological damage in DN rats, which was related to the regulation of the PI3K-Akt and VEGFA-NOS3 signaling pathways.

Sestrin2 Signaling Pathway Regulates Podocyte Biology and Protects against Diabetic Nephropathy

Sestrin2 regulates cell homeostasis and is an upstream signaling molecule for several signaling pathways. Sestrin2 leads to AMP-activated protein kinase- (AMPK-) and GTPase-activating protein activity toward Rags (GATOR) 1-mediated inhibition of mammalian target of rapamycin complex 1 (mTORC1), thereby enhancing autophagy. Sestrin2 also improves mitochondrial biogenesis via AMPK/Sirt1/peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) signaling pathway. Blockade of ribosomal protein synthesis and augmentation of autophagy by Sestrin2 can prevent misfolded protein accumulation and attenuate endoplasmic reticulum (ER) stress. In addition, Sestrin2 enhances P62-mediated autophagic degradation of Keap1 to release nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 release by Sestrin2 vigorously potentiates antioxidant defense in diabetic nephropathy. Impaired autophagy and mitochondrial biogenesis, severe oxidative stress, and ER stress are all deeply involved in the development and progression of diabetic nephropathy. It has been shown that Sestrin2 expression is lower in the kidney of animals and patients with diabetic nephropathy. Sestrin2 knockdown aggravated diabetic nephropathy in animal models. In contrast, upregulation of Sestrin2 enhanced autophagy, mitophagy, and mitochondrial biogenesis and suppressed oxidative stress, ER stress, and apoptosis in diabetic nephropathy. Consistently, overexpression of Sestrin2 ameliorated podocyte injury, mesangial proliferation, proteinuria, and renal fibrosis in animal models of diabetic nephropathy. By suppressing transforming growth factor beta (TGF-β)/Smad and Yes-associated protein (YAP)/transcription enhancer factor 1 (TEF1) signaling pathways in experimental models, Sestrin2 hindered epithelial-mesenchymal transition and extracellular matrix accumulation in diabetic kidneys. Moreover, modulation of the downstream molecules of Sestrin2, for instance, augmentation of AMPK or Nrf2 signaling and inhibition of mTORC1, has been protective in diabetic nephropathy. Regarding the beneficial effects of Sestrin2 on diabetic nephropathy and its interaction with several signaling molecules, it is worth targeting Sestrin2 in diabetic nephropathy.

The Effectiveness and Safety of Abelmoschus manihot in Treating IgA Nephropathy: A Systematic Review and Meta-Analysis

Introduction

IgA nephropathy (IgAN) is a common issue. In China, Abelmoschus manihot (AM) is widely used in the treatment of IgAN. However, their combined effectiveness and safety for this purpose have not yet been explored. AM is an effective medicine for treating IgAN. This meta-analysis aimed to evaluate the effectiveness of AM for IgAN.

Materials and Methods

The Cochrane Library, PubMed, EMBASE, Allied and Complementary Medicine Database (AMED), Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure Database (CNKI), Chinese Science and Technique Journals Database (VIP), and the Wanfang Database were searched from their inceptions to June 2021. Random clinical trials (RCTs) comparing the effects of AM treatment in patients with IgAN were included. The study evaluated the efficacy or effectiveness of AM for IgAN and had clear outcome data, such as total effectiveness rate or proteinuria.

Results

A total of 11 RCTs with 850 participants were included in this meta-analysis. The results of the meta-analysis showed that, compared with that of the conventional therapy alone, being combined with conventional treatment was significantly more effective for the total efficacy rate (OR = 4.33; 95% CI = 2.66, 7.04; P < 0.00001) and proteinuria (MD = -0.41 g/24 h; 95% CI = -0.44, -0.38; P < 0.00001) but had no effect on serum creatinine (Scr) (MD = -2.23 μmol/L; 95% CI = -5.90, 1.45; P=0.24), eGFR (MD = -0.45 mL/min·1.73 m2; 95% CI = -1.24, 2.13; P=0.60), Bun (MD = -0.22 mmol/L; 95% CI = -0.59, 0.14; P=0.23), systolic blood pressure (MD = -0.04 mmHg; 95% CI = -2.59, 2.51; P=0.98), diastolic blood pressure (MD = -0.34 mmHg, 95% CI = -1.65, 2.33; P=0.74), systolic blood pressure (MD = -0.04 mmHg, 95% CI = -2.59, 2.51; P=0.98), or serum albumin (MD = 1.70 g/L, 95% CI = -1.06, 4.45; P=0.23).

Conclusions

AM provided additional benefits to proteinuria individuals with IgAN. However, due to the high clinical heterogeneity and small sample size of the included trials, future studies should conduct more rigorous RCTs on the clinical efficacy and safety of AM and RCTs with a larger sample size involving multicenters.

Efficacy and safety of Abelmoschus moschatus capsules combined with tripterygium glycoside tablets on diabetic nephropathy: A systematic review and meta-analysis

Background: Diabetic nephropathy (DN) is one of the most serious chronic micro-vascular complications of diabetes and the leading cause of end-stage kidney disease (ESRD) worldwide, with reduced expectancy and quality of life and colossal financial and social burden worldwide. In spite of emerging treatments on DN, effective therapy on delaying the progression of DN is still lacking. In clinical practice, there are many studies focusing on Abelmoschus moschatus (AM) capsules together with Tripterygium glycoside (TG) tablets in the treatment of DN, and excellent results have been obtained.

Objective: The study aimed to evaluate the efficacy and safety of AM combined with TG in the treatment of DN.

Methods: Databases including PubMed, Web of Science, Cochrane Library, Embase, CNKI, WF, and VIP were searched from their inception to 1 March 2022. The “risk of bias” evaluation tool produced by the Cochrane Collaboration Handbook was used for evaluating the quality of the included studies. Revman 5.3 software was used for meta-analysis.

Results: Here, 11 studies with a total of 1,072 participants were included for this meta-analysis. Our results showed that AM combined with TG plus basic treatment could lower levels of 24 h-UP [MD = -0.18; 95% CI: (-0.21, -0.14); p < 0.00001], Scr [MD = -15.29; 95% CI: (-28.69, -1.88); p = 0.03], and BUN [MD = -1.18; 95% CI: (-1.69, -0.68); p < 0.00001]. Meanwhile, the adverse reaction rate increased in the combination group [RR = 1.88; 95% CI (1.26, 2.82); p = 0.002].

Conclusion: Current evidence suggests that AM combined with TG may be more effective in the treatment of DN, which will be highly beneficial to further theoretical discussion and practical clinical applications. However, the safety cannot be ignored because of nearly increasing 2-fold adverse events, although they can be mitigated through systematic treatment. Meanwhile, due to low quality of the included studies, great possibility of publication bias, and large heterogeneity among different studies, the results of our review should be evaluated with more prudence and high-quality RCTs are warranted to confirm this in the future.

Systematic review Registration:www.crd.york.ac.uk, identifier CRD42022344359.

Evidence construction of Huangkui capsule against chronic glomerulonephritis: A systematic review and network pharmacology

BACKGROUND

Chronic glomerulonephritis (CGN) is a relatively common primary glomerular disease. Huangkui capsule (HKC) combined with angiotensin receptor blocker (ARB) for CGN is frequently used in clinical practice, however, there is still lack of high-quality evidence-based evidence and network pharmacology to clarify the therapeutic efficacy and pharmacological mechanisms.

PURPOSE

Integrating evidence-based medicine and network pharmacology to explain the therapeutic efficacy and pharmacological mechanisms of ARB combined with HKC for CGN.

METHODS

Studies matching the topic were searched from PubMed, Web of Science, Embase database, the Cochrane Library, Chinese National Knowledge Infrastructure, CBM databases, the VIP medicine information system and the Wanfang database and screened according to inclusion and exclusion criteria. The data of the included studies were meta-analyzed by blood urea nitrogen (BUN), serum creatinine (SCR), 24-h urine protein (24hUP) and effective rate (ER). A meta-analysis of the data from the included studies was performed. Then, based on the network pharmacology, the chemical ingredients in HKC and their targets of action, disease targets, common targets and other relevant information were screened, and the key pathways were relevantly annotated based on bioinformatics technology to explore the potential mechanisms of HKC and ARB for CGN.

RESULTS

The results showed that SCR index (p < 0.05), 24hUP index (p < 0.001) in the group treated with HKC and ARB were significantly lower than those in the control group. BUN index in the group treated with HKC and VAL were significantly lower than those in the control group (p < 0.001). Effective rate index in the group treated with HKC and ARB was significantly higher than those in the control group (p < 0.001). There was no significant difference in BUN treated with IRB, LOS, and TEL (p = 0.181; p = 0.811; p = 0.067). Based on network pharmacology, the results were as follows: The PPI network indicated that STAT3, AKT1, MAPK1, TP53 and JUN were key target proteins. The results of KEGG analysis suggested that the pharmacological mechanisms were mainly associated with AGE-RAGE signaling pathway in diabetic complications.

CONCLUSION

The combination of ARB and HKC can achieve better therapeutic effects in the treatment of CGN, meanwhile, ARB and HKC have a significant improved effectiveness in the treatment of CGN compared with ARB or HKC alone. In addition, HKC and ARB synergistically treated CGN through a multi-pathway network.

Efficacy and safety of Abelmoschus manihot in treating chronic kidney diseases: A multicentre, open-label and single-arm clinical trial

RATIONALE AND OBJECTIVE

The efficacy of Abelmoschus manihot (AM) in treating of chronic kidney disease (CKD) has been confirmed by prior trials. AM is also commonly combined to other medicines among CKD patients in clinic. This trial aimed at evaluating the safety of AM combination application, and further verifying the efficacy of AM in treating various types of CKD.

STUDY DESIGN

A multicentre, prospective, open-label, single-arm trial SETTING AND PARTICIPANTS: Approximately 2000 CKD patients with proteinuria (≥ 150 mg/d), from 105 centres across China INTERVENTIONS: AM was administered to patients three times per day for 24 weeks: the daily dose was based on age (> 12 years old: 2.5 g tid; 6∼12 years old: 1.5 g tid; 2∼6 years old: 1 g tid) OUTCOMES: The efficacy outcomes were the change in 24-hour proteinuria and estimated glomerular filtration rate (eGFR) from baseline to week 24. Safety outcomes included adverse events and laboratory tests.

RESULTS

2054 CKD patients from 105 centres were enrolled in this trial, with 1843 (89.7%) completing the 24-week follow-up. The participants' median age was 44 years old and 44.6% were female. Compared to baseline, 24-hour proteinuria decreased 471 mg (95% confident interval, 367 to 575, p < 0.001) at week 24. eGFR did not change significantly relative to baseline with the mean increase as 1.7 ml/min/1.73 m2 (95% confident interval, -0.3 to 3.7, p = 0.09). 902 (43.9%) participants combined medication to AM during follow-up. The total incidence of adverse events was 12.9%; and the most common adverse events were hyperlipidaemia (4.1%), abnormal liver function (2.3%), upper respiratory infection (1.8%), and hyperglycaemia (1.1%). Combined medications did not change the risk for hyperlipidaemia and upper respiratory infection. The combination application with antiplatelet reagents increased the risk of abnormal liver function, and with calcium channel blockers increased the risk of hyperglycaemia.

LIMITATIONS

Single-arm clinical trial and short observation time CONCLUSION: We have provided safety information of AM on various types of CKD in a large trial, especially when combination to medications most commonly prescribed to CKD patients. AM also showed to decrease proteinuria with stable kidney function during follow up. AM is a promising treatment for CKD patients.

Effects of Abelmoschus manihot Flower Extract on Enhancing Sexual Arousal and Reproductive Performance in Zebrafish

The flower of Abelmoschus manihot L. is mainly used for the treatment of chronic kidney diseases, and has been reported to have bioactivities such as antioxidant, anti-inflammatory, antiviral, and antidepressant activities. This study used wild-type adult zebrafish as an animal model to elucidate the potential bioactivity of A. manihot flower ethanol extract (AME) in enhancing their sexual and reproductive functions. Zebrafish were fed AME twice a day at doses of 0.2%, 1%, and 10% for 28 days, and were then given the normal feed for an additional 14 days. The hormone 17-β estradiol was used as the positive control. Sexual behavioral parameters such as the number of times males chased female fish, the production of fertilized eggs, and the hatching rate of the fertilized eggs were recorded at days 0.33, 7, 14, 21, 28, and 42. The expression levels of sex-related genes—including lhcgr, ar, cyp19a1a, and cyp19a1b—were also examined. The results showed that the chasing number, fertilized egg production, and hatching rate were all increased with the increase in the AME treatment dose and treatment time. After feeding with 1% and 10% AME for 28 days, the chasing number in the treated group as compared to the control group increased by 1.52 times and 1.64 times, respectively; the yield of fertilized eggs increased by 1.59 times and 2.31 times, respectively; and the hatching rate increased by 1.26 times and 1.69 times, respectively. All three parameters exhibited strong linear correlations with one another (p < 0.001). The expression of all four genes was also upregulated with increasing AME dose and treatment duration. When feeding with 0.2%, 1%, and 10% AME for 28 days, the four sex-related genes were upregulated at ranges of 1.79−2.08-fold, 2.74−3.73-fold, and 3.30−4.66-fold, respectively. Furthermore, the effect of AME was persistent, as the promotion effect continued after the treatment was stopped for at least two weeks. The present findings suggest that AME can enhance the endocrine system and may improve libido and reproductive performance in zebrafish.

Fucoidan Alleviates Renal Fibrosis in Diabetic Kidney Disease via Inhibition of NLRP3 Inflammasome-Mediated Podocyte Pyroptosis

Background: Fucoidan (FPS) has been widely used to treat renal fibrosis (RF) in patients with diabetic kidney disease (DKD); however, the precise therapeutic mechanisms remain unclear. Recently, research focusing on inflammation-derived podocyte pyroptosis in DKD has attracted increasing attention. This phenomenon is mediated by the activation of the nucleotide-binding oligomerization domain (Nod)-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, leading to RF during DKD progression. Therefore, we designed a series of experiments to investigate the ameliorative effects of FPS on RF in DKD and the mechanisms that are responsible for its effect on NLRP3 inflammasome-mediated podocyte pyroptosis in the diabetic kidney.

Methods: The modified DKD rat models were subjected to uninephrectomy, intraperitoneal injection of streptozotocin, and a high-fat diet. Following induction of renal injury, the animals received either FPS, rapamycin (RAP), or a vehicle for 4 weeks. For in vitro research, we exposed murine podocytes to high glucose and MCC950, an NLRP3 inflammasome inhibitor, with or without FPS or RAP. Changes in the parameters related to RF and inflammatory podocyte injury were analyzed in vivo. Changes in podocyte pyroptosis, NLRP3 inflammasome activation, and activation of the adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin complex 1 (mTORC1)/NLRP3 signaling axis involved in these changes were analyzed in vivo and in vitro.

Results: FPS and RAP ameliorated RF and inflammatory podocyte injury in the DKD model rats. Moreover, FPS and RAP attenuated podocyte pyroptosis, inhibited NLRP3 inflammasome activation, and regulated the AMPK/mTORC1/NLRP3 signaling axis in vivo and in vitro. Notably, our data showed that the regulative effects of FPS, both in vivo and in vitro, on the key signaling molecules, such as p-AMPK and p-raptor, in the AMPK/mTORC1/NLRP3 signaling axis were superior to those of RAP, but similar to those of metformin, an AMPK agonist, in vitro.

Conclusion: We confirmed that FPS, similar to RAP, can alleviate RF in DKD by inhibiting NLRP3 inflammasome-mediated podocyte pyroptosis via regulation of the AMPK/mTORC1/NLRP3 signaling axis in the diabetic kidney. Our findings provide an in-depth understanding of the pathogenesis of RF, which will aid in identifying precise targets that can be used for DKD treatment.

Application of weighted gene co-expression network analysis to identify novel key genes in diabetic nephropathy

AIMS/INTRODUCTION

Diabetic nephropathy (DN) is among the leading causes of end-stage renal disease worldwide. DN pathogenesis remains largely unknown. Weighted gene co-expression network analysis is a powerful bioinformatic tool for identifying key genes in diseases.

MATERIALS AND METHODS

The datasets GSE30122, GSE104948, GSE37463 and GSE47185 containing 23 DN and 23 normal glomeruli samples were obtained from the National Center for Biotechnology Information Gene Expression Omnibus database. After data pre-processing, weighted gene co-expression network analysis was carried out to cluster significant modules. Then, Gene Set Enrichment Analysis-based Gene Ontology analysis and visualization of network were carried out to screen the key genes in the most significant modules. The connectivity map analysis was carried out to find the significant chemical compounds. Finally, some key genes were validated in in vivo and in vitro experiments.

RESULTS

A total of 454 upregulated and 392 downregulated genes were identified. A total of 16 modules were clustered, and the most significant modules (green, red and yellow modules) were determined. The green module was associated with extracellular matrix organization, the red module was associated with immunity reaction and the yellow module was associated with kidney development. We found several key genes in these three modules separately, and part of them were validated in vivo and in vitro successfully. We found the top 15 chemical compounds that could perturb the overall expression of key genes in DN.

CONCLUSION

Weighted gene co-expression network analysis was applied to DN expression profiling in combination with connectivity map analysis. Several novel key genes and chemical compounds were screened out, providing new molecular targets for DN.

Huangkui capsule in combination with metformin ameliorates diabetic nephropathy via the Klotho/TGF-β1/p38MAPK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Huangkui capsule (HKC), extracted from Abelmoschus manihot (L.) medic (AM), as a patent proprietary Chinese medicine on the market for approximately 20 years, has been clinically used to treat chronic glomerulonephritis. Renal fibrosis has been implicated in the onset and development of diabetic nephropathy (DN). However, the potential application of HKC for preventing DN has not been evaluated.

AIM OF THE STUDY

This study was designed to investigate the efficacy and underlying mechanisms of HKC combined with metformin (MET), the first-line medication for treating type 2 diabetes, in the treatment of renal interstitial fibrosis.

MATERIALS AND METHODS

A rat model of diabetes-associated renal fibrosis was established by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg) combined with a high-fat and high-glucose diet. The rats were randomly divided into five groups: normal control, DN, HKC (1.0 g/kg/day), MET (100 mg/kg/d), and HKC plus MET (1.0 g/kg/day + 100 mg/kg/d). Following drug administration for 8 weeks, we collected blood, urine, and kidney tissue for analysis. Biochemical markers and metabolic parameters were detected using commercial kits. Histopathological staining was performed to monitor morphological changes in the rat kidney. High-glucose-induced human kidney HK-2 cells were used to evaluate the renal protective effects of HKC combined with MET (100 μg/mL+10 mmol/L). MTT assay and acridine orange/ethidium bromide were used to examine cell proliferation inhibition rates and apoptosis. Immunofluorescence assay and Western blot analysis were performed to detect renal fibrosis-related proteins including Klotho, TGF-β1, and phosphorylated (p)-p38.

RESULTS

Combination therapy (HKC plus MET) significantly improved the weight, reduced blood glucose (BG), blood urea nitrogen (BUN), total cholesterol (T-CHO), triglycerides (TG), low-density lipoprotein (LDL) and increased the level of high-density lipoprotein (HDL) of DN rats. Combination therapy also significantly reduced urine serum creatinine (SCR) and urine protein (UP) levels as well as reduced the degrees of renal tubule damage and glomerulopathy in DN rats. Combination therapy ameliorated renal fibrosis, as evidenced by reduced levels of alpha-smooth muscle actin and fibronectin and increased expression of E-cadherin in the kidneys. Moreover, HKC plus MET alleviated the degree of DN in part via the Klotho/TGF-β1/p38MAPK signaling pathway. In vitro experiments showed that combination therapy significantly inhibited cell proliferation and apoptosis and regulated fibrosis-related proteins in high-glucose (HG)-induced HK-2 cells. Further studies revealed that combination therapy suppressed cell proliferation and fibrosis by inhibiting the Klotho-dependent TGF-β1/p38MAPK pathway.

CONCLUSIONS

HKC plus MET in combination suppressed abnormal renal cell proliferation and fibrosis by inhibiting the Klotho-dependent TGF-β1/p38MAPK pathway. Collectively, HKC combined with MET effectively improved DN by inhibiting renal fibrosis-associated proteins and blocking the Klotho/TGF-β1/p38MAPK signaling pathway. These findings improve the understanding of the pathogenesis of diabetes-associated complications and support that HKC plus MET combination therapy is a promising strategy for preventing DN.

Efficacy and safety of Huangkui capsule for diabetic nephropathy: A protocol for systematic review and meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is 1 of the most serious complications of diabetes mellitus and the leading cause of end-stage renal disease in the world. Huangkui capsule, extracted from Abelmoschus manihot (L.) medic (AM), has been widely used to treat DN. However, there is no consensus on the efficacy of Huangkui capsule for DN. This study aims to perform meta-analysis to systematically review the efficacy and safety of Huangkui capsule.

METHODS

The following 9 electronic databases will be comprehensively searched: PubMed, web of science, MEDLINE, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Scientific Journals Database, Wanfang data, and Chinese BioMedicine Literature Database. The retrieval time is from their inception to May 2021. According to the inclusion and exclusion criteria, 2 reviewers independently completed the study selection, data extraction, risk of bias assessment, and data synthesis. Review Manager Version 5.3 software will be used to conduct meta-analysis.

RESULTS

This study provides a high-quality synthesis to assess the efficacy of Huangkui capsule for treating diabetic nephropathy.

CONCLUSION

The result of this systematic review will provide objective evidence-based basis to judge the effectiveness and safety of Huangkui capsule on diabetic nephropathy.

Autophagic Activation and Decrease of Plasma Membrane Cholesterol Contribute to Anticancer Activities in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC), an aggressive subtype of pulmonary carcinomas with high mortality, accounts for 85% of all lung cancers. Drug resistance and high recurrence rates impede the chemotherapeutic effect, making it urgent to develop new anti-NSCLC agents. Recently, we have demonstrated that para-toluenesulfonamide is a potential anti-tumor agent in human castration-resistant prostate cancer (CRPC) through inhibition of Akt/mTOR/p70S6 kinase pathway and lipid raft disruption. In the current study, we further addressed the critical role of cholesterol-enriched membrane microdomain and autophagic activation to para-toluenesulfonamide action in killing NSCLC. Similar in CRPC, para-toluenesulfonamide inhibited the Akt/mTOR/p70S6K pathway in NSCLC cell lines NCI-H460 and A549, leading to G1 arrest of the cell cycle and apoptosis. Para-toluenesulfonamide significantly decreased the cholesterol levels of plasma membrane. External cholesterol supplement rescued para-toluenesulfonamide-mediated effects. Para-toluenesulfonamide induced a profound increase of LC3-II protein expression and a significant decrease of p62 expression. Double staining of lysosomes and cellular cholesterol showed para-toluenesulfonamide-induced lysosomal transportation of cholesterol, which was validated using flow cytometric analysis of lysosome staining. Moreover, autophagy inhibitors could blunt para-toluenesulfonamide-induced effect, indicating autophagy induction. In conclusion, the data suggest that para-toluenesulfonamide is an effective anticancer agent against NSCLC through G1 checkpoint arrest and apoptotic cell death. The disturbance of membrane cholesterol levels and autophagic activation may play a crucial role to para-toluenesulfonamide action.

Baicalin improves podocyte injury in rats with diabetic nephropathy by inhibiting PI3K/Akt/mTOR signaling pathway

Objective

To investigate the effect of baicalin on diabetic nephropathy (DN) rats and podocytes and its mechanism.

Methods

The rat models with DN were established by high-fat and high-sugar diet and intraperitoneal injection of streptozotocin. The fasting blood glucose (FBG) and weight of rats in each group were measured at 0, 1, 2, 3, and 4 weeks. Their biochemical indicators, expression of inflammatory, and antioxidant factors were measured using an automatic biochemical analyzer together with ELISA. Hematoxylin-eosin staining and periodic acid-schiff staining were used to observe the morphological changes in the kidneys of rats in each group. Finally, the expressions of related molecules and PI3K/Akt/mTOR signaling pathway proteins in renal tissues and podocytes were examined by qRT-PCR and Western blot.

Results

Compared with the DN group, the FBG and weight, serum creatinine, blood urea nitrogen, total cholesterol, triacylglycerol, microalbumin, and albumin/creatinine ratio were all significantly decreased in the Baicalin treatment groups in a concentration-dependent manner. The levels of inflammatory factors in kidney tissue and podocytes were decreased. In addition, the activities of lactate dehydrogenase and malondialdehyde in tissue were decreased, while the superoxide dismutase was increased. The pathological sections showed that glomerular atrophy and glomerular basement membrane thickening caused by hyperglycemia were improved in the Baicalin treatment groups. Meanwhile, baicalin inhibited the downregulation of Nephrin and Podocin expressions and upregulation of Desmin expression caused by DN, and inhibited the expressions of p-PI3K, p-Akt, and p-mTOR proteins.

Conclusion

Baicalin slows down podocyte injury caused by DN by inhibiting the activity of PI3K/Akt/mTOR signaling pathway.

Clinical efficacies, underlying mechanisms and molecular targets of Chinese medicines for diabetic nephropathy treatment and management

Diabetic nephropathy (DN) has been recognized as a severe complication of diabetes mellitus and a dominant pathogeny of end-stage kidney disease, which causes serious health problems and great financial burden to human society worldwide. Conventional strategies, such as renin-angiotensin-aldosterone system blockade, blood glucose level control, and bodyweight reduction, may not achieve satisfactory outcomes in many clinical practices for DN management. Notably, due to the multi-target function, Chinese medicine possesses promising clinical benefits as primary or alternative therapies for DN treatment. Increasing studies have emphasized identifying bioactive compounds and molecular mechanisms of reno-protective effects of Chinese medicines. Signaling pathways involved in glucose/lipid metabolism regulation, antioxidation, anti-inflammation, anti-fibrosis, and podocyte protection have been identified as crucial mechanisms of action. Herein, we summarize the clinical efficacies of Chinese medicines and their bioactive components in treating and managing DN after reviewing the results demonstrated in clinical trials, systematic reviews, and meta-analyses, with a thorough discussion on the relative underlying mechanisms and molecular targets reported in animal and cellular experiments. We aim to provide comprehensive insights into the protective effects of Chinese medicines against DN.

Inhibition of Renal Tubular Epithelial Mesenchymal Transition and Endoplasmic Reticulum Stress-Induced Apoptosis with Shenkang Injection Attenuates Diabetic Tubulopathy

Background: The proximal renal tubule plays a critical role in diabetic kidney disease (DKD) progression. Early glomerular disease in DKD triggers a cascade of injuries resulting in renal tubulointerstitial disease. These pathophysiological responses are collectively described as diabetic tubulopathy (DT). Thus, therapeutic strategies targeting DT hold significant promise for early DKD treatment. Shenkang injection (SKI) has been widely used to treat renal tubulointerstitial fibrosis in patients with chronic kidney disease in China. However, it is still unknown whether SKI can alleviate DT. We designed a series of experiments to investigate the beneficial effects of SKI in DT and the mechanisms that are responsible for its effect on epithelial-to-mesenchymal transition (EMT) and endoplasmic reticulum (ER) stress-induced apoptosis in DT.

Methods: The modified DKD rat models were induced by uni-nephrectomy, streptozotocin intraperitoneal injection, and a high-fat diet. Following the induction of renal injury, these animals received either SKI, rosiglitazone (ROS), or vehicle, for 42 days. For in vitro research, we exposed NRK-52E cells to high glucose (HG) and 4-phenylbutyric acid (4-PBA) with or without SKI or ROS. Changes in parameters related to renal tubular injury and EMT were analyzed in vivo. Changes in the proportion of apoptotic renal tubular cells and ER stress, and the signaling pathways involved in these changes, were analyzed both in vivo and in vitro.

Results: SKI and ROS improved the general condition, the renal morphological appearance and the key biochemical parameters, and attenuated renal injury and EMT in the rat model of DKD. In addition, SKI and ROS alleviated apoptosis, inhibited ER stress, and suppressed PERK-eIF2α-ATF4-CHOP signaling pathway activation both in vivo and in vitro. Notably, our data showed that the regulatory in vitro effects of SKI on PERK-eIF2α-ATF4-CHOP signaling were similar to those of 4-PBA, a specific inhibitor of ER stress.

Conclusion: This study confirmed that SKI can alleviate DT in a similar manner as ROS, and SKI achieves this effect by inhibiting EMT and ER stress-induced apoptosis. Our findings thereby provide novel information relating to the clinical value of SKI in the treatment of DT.

Total Flavones of Abelmoschus manihot Ameliorates Podocyte Pyroptosis and Injury in High Glucose Conditions by Targeting METTL3-Dependent m6A Modification-Mediated NLRP3-Inflammasome Activation and PTEN/PI3K/Akt Signaling

Background: The total flavones of Abelmoschus manihot (TFA), a compound that is extracted from Abelmoschus manihot, has been widely used in China to reduce podocyte injury in diabetic kidney disease (DKD). However, the mechanisms underlying the therapeutic action of this compound have yet to be elucidated. Podocyte pyroptosis is characterized by activation of the NLRP3 inflammasome and plays an important role in inflammation-mediated diabetic kidneys. Regulation of the PTEN/PI3K/Akt pathway is an effective strategy for improving podocyte damage in DKD. Previous research has also shown that N6-methyladenosine (m6A) modification is involved in DKD and that m6A-modified PTEN regulates the PI3K/Akt pathway. In this study, we investigated whether TFA alleviates podocyte pyroptosis and injury by targeting m6A modification-mediated NLRP3-inflammasome activation and PTEN/PI3K/Akt signaling. Methods: We used MPC-5 cells under high glucose (HG) conditions to investigate the key molecules that are involved in podocyte pyroptosis and injury, including activation of the NLRP3 inflammasome and the PTEN/PI3K/Akt pathway. We detected alterations in the levels of three methyltransferases that are involved in m6A modification. We also investigated changes in the levels of these key molecules in podocytes with the overexpression or knockdown of methyltransferase-like (METTL)3. Results: Analysis showed that TFA and MCC950 protected podocytes against HG-induced pyroptosis and injury by reducing the protein expression levels of gasdermin D, interleukin-1β, and interleukin-18, and by increasing the protein expression levels of nephrin, ZO-1, WT1 and podocalyxin. TFA and 740Y-P inhibited activation of the NLRP3 inflammasome via the PI3K/Akt pathway by inhibiting the protein levels of NIMA-related kinase7, NLRP3, ASC, and caspase-1, and by increasing the protein expression levels of p-PI3K and p-Akt. TFA improved pyroptosis and injury in HG-stimulated podocytes by regulating METTL3-dependent m6A modification. Conclusion: Collectively, our data indicated that TFA could ameliorate pyroptosis and injury in podocytes under HG conditions by adjusting METTL3-dependent m6A modification and regulating NLRP3-inflammasome activation and PTEN/PI3K/Akt signaling. This study provides a better understanding of how TFA can protect podocytes in DKD.

β-LAPachone is renoprotective in streptozotocin-induced diabetic mice via regulating the PI3K/Akt/mTOR signaling pathway

OBJECTIVES

β-LAPachone (B-LAP) is a natural product with established anti-inflammatory properties. In this study, we investigated the protective potential of B-LAP against diabetic nephropathy in streptozotocin (STZ) induced diabetic mice.

MATERIALS AND METHODS

Diabetes induction in mice was carried out by a single intraperitoneal injection of STZ. 2.5 mg/kg/day and 5 mg/kg/day doses of B-LAP were administered orally for twelve weeks and renal histoarchitecture, caspase-3, tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), glutathione peroxidase (GPX), as well as urinary nephrin and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated. Additionally, kidney levels of PI3K, phosphorylated (p)-Akt, p-mTOR, p-CREB, and SIRT1 were assessed in the present investigation.

RESULTS

5 mg/kg B-LAP significantly decreased urinary excretions of nephrin and NGAL. It also mitigated renal TNF-α and MDA levels and simultaneously improved GPX activities. 5 mg/kg B-LAP improved renal function in diabetic mice as indicated by elevated values of creatinine clearance. While B-LAP elevated renal levels of SIRT1, it alleviated PI3K, p-Akt, p-mTOR, and p-CREB levels in the kidneys of diabetic mice.

CONCLUSION

Collectively, these findings suggest B-LAP as a potential renoprotective agent in STZ-induced diabetic mice probably via modulating the PI3K/Akt/mTOR pathway.

Hyperoside ameliorates diabetic nephropathy induced by STZ via targeting the miR-499-5p/APC axis

Diabetic nephropathy is a serious complication of diabetes. Hyperoside has been widely reported to ameliorate diabetes-associated disease. The current study is designed to explore the mechanism of hyperoside in diabetic nephropathy. In the present study, high glucose was used to treat podocytes. Diabetic nephropathy mice models were established by high-fat feeding followed by multiple low dose injections of streptozocin. Western blot analysis was conducted for detection of extracellular matrix accumulation, inflammatory response and cell apoptosis. We found out that hyperoside improved high glucose-induced cell injury. Additionally, hyperoside prevented mice with diabetic nephropathy from diabetic symptoms and renal dysfunction. Mechanistically, hyperoside inhibited the mRNA and protein expression of APC. MiR-499-5p was found to be an upstream negative mediator of APC, and hyperoside induced the upregulation of miR-499-5p. MiR-499-5p bound with the 3' untranslated region of APC to inhibit its expression. Finally, rescue assays revealed that the suppressive effects of miR-499-5p overexpression on renal dysfunction were rescued by upregulation of APC in mice with diabetic nephropathy. In conclusion, these findings indicated that hyperoside ameliorates diabetic nephropathy via targeting the miR-499-5p/APC axis, suggesting that hyperoside may offer a potential tactic for diabetic nephropathy treatment.

Fucoidan Ameliorates Renal Injury-Related Calcium-Phosphorus Metabolic Disorder and Bone Abnormality in the CKD-MBD Model Rats by Targeting FGF23-Klotho Signaling Axis

Background: Recently, chronic kidney disease (CKD)-mineral and bone disorder (MBD) has become one of common complications occurring in CKD patients. Therefore, development of a new treatment for CKD-MBD is very important in the clinic. In China, Fucoidan (FPS), a natural compound of Laminaria japonica has been frequently used to improve renal dysfunction in CKD. However, it remains elusive whether FPS can ameliorate CKD-MBD. FGF23-Klotho signaling axis is reported to be useful for regulating mineral and bone metabolic disorder in CKD-MBD. This study thereby aimed to clarify therapeutic effects of FPS in the CKD-MBD model rats and its underlying mechanisms in vivo and in vitro, compared to Calcitriol (CTR). Methods: All male rats were divided into four groups: Sham, CKD-MBD, FPS and CTR. The CKD-MBD rat models were induced by adenine administration and uninephrectomy, and received either FPS or CTR or vehicle after induction of renal injury for 21 days. The changes in parameters related to renal dysfunction and renal tubulointerstitial damage, calcium-phosphorus metabolic disorder and bone lesion were analyzed, respectively. Furthermore, at sacrifice, the kidneys and bone were isolated for histomorphometry, immunohistochemistry and Western blot. In vitro, the murine NRK-52E cells were used to investigate regulative actions of FPS or CTR on FGF23-Klotho signaling axis, ERK1/2-SGK1-NHERF-1-NaPi-2a pathway and Klotho deficiency. Results: Using the modified CKD-MBD rat model and the cultured NRK-52E cells, we indicated that FPS and CTR alleviated renal dysfunction and renal tubulointerstitial damage, improved calcium-phosphorus metabolic disorder and bone lesion, and regulated FGF23-Klotho signaling axis and ERK1/2-SGK1-NHERF-1-NaPi-2a pathway in the kidney. In addition, using the shRNA-Klotho plasmid-transfected cells, we also detected, FPS accurately activated ERK1/2-SGK1-NHERF-1-NaPi-2a pathway through Klotho loss reversal. Conclusion: In this study, we emphatically demonstrated that FPS, a natural anti-renal dysfunction drug, similar to CTR, improves renal injury-related calcium-phosphorus metabolic disorder and bone abnormality in the CKD-MBD model rats. More importantly, we firstly found that beneficial effects in vivo and in vitro of FPS on phosphorus reabsorption are closely associated with regulation of FGF23-Klotho signaling axis and ERK1/2-SGK1-NHERF-1-NaPi-2a pathway in the kidney. This study provided pharmacological evidences that FPS directly contributes to the treatment of CKD-MBD.

Role of mTOR Complex 1 Signaling Pathway in the Pathogenesis of Diabetes Complications; A Mini Review

The mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine-protein kinase that senses and combines various environmental signals to regulate the growth and homeostasis of human cells. This signaling pathway synchronizes many critical cellular processes and is involved in an increasing number of pathological conditions such as diabetes, cancer, obesity, and metabolic syndrome. Here, we review different complications of diabetes that are associated with mTOR complex 1 imbalance. We further discuss pharmacological approaches to treat diabetes complications linked to mTOR deregulation.

Geraniol ameliorates diabetic nephropathy via interference with miRNA-21/PTEN/Akt/mTORC1 pathway in rats

Deregulated activity of protein kinase B/mammalian target of rapamycin complex-1 (Akt/mTORC1) incites crucial pathological characteristics of diabetic nephropathy. The acyclic monoterpene geraniol has been recently reported to possess antidiabetic effects; however, its potential renoprotective effect in diabetes has not yet been elucidated. This study aimed to assess the possible modulatory effect of geraniol on the Akt/mTORC1 pathway in diabetes-induced nephropathy in rats compared to the standard antidiabetic drug gliclazide. Geraniol and gliclazide was administered daily to diabetic rats for 6 weeks starting on the 3rd-day post diabetes induction by streptozotocin (STZ). Geraniol amended the deteriorated renal function (serum creatinine; blood urea nitrogen). It exerted a remarkable antihyperglycemic effect that is comparable to that of gliclazide and suppressed the fibrotic marker, transforming growth factor-β. Geraniol restored redox balance and inhibited lipid peroxidation by reducing nicotine amide adenine dinucleotide phosphate oxidase and enhancing the antioxidant enzyme, superoxide dismutase. These beneficial effects were associated with a robust downregulation of miRNA-21 and consequently, reversion of tumor suppressor protein phosphatase and tension homolog (PTEN)/Akt/mTORC1 cue and its downstream proteins required for mesangial cell proliferation and matrix protein synthesis. The current study indicates that geraniol interfered with miRNA-21/ PTEN/AKT/mTORC1 pathway signaling that contributes largely to the progression of mesangial expansion and extracellular matrix deposition in diabetic nephropathy.

Celastrol slows the progression of early diabetic nephropathy in rats via the PI3K/AKT pathway

Background

Diabetic nephropathy serves as one of the most regular microvascular complications of diabetes mellitus and is the main factor that causes end-stage renal disease and incident mortality. As the beneficial effect and minute adverse influence of Celastrol on the renal system requires further elucidation, the renoprotective function of Celastrol in early diabetic nephropathy was investigated.

Methods

In high-fat and high-glucose diet/streptozotocin-induced diabetic rats which is the early diabetic nephropathy model, ALT, AST, 24 h urinary protein, blood urea nitrogen, and serum creatinine content were observed. Periodic acid-Schiff staining, enzyme-linked immunosorbent assay, immunohistochemical analysis, reverse transcription-polymerase chain reaction, and western blot analysis were used to explore the renoprotective effect of Celastrol to diabetic nephropathy rats and the underlying mechanism.

Results

High dose of Celastrol (1.5 mg/kg/d) not only improved the kidney function of diabetic nephropathy (DN) rats, and decreased the blood glucose and 24 h urinary albumin, but also increased the expression of LC3II and nephrin, and downregulated the expression of PI3K, p-AKT, and the mRNA level of NF-κB and mTOR.

Conclusion

Celastrol functions as a potential therapeutic substance, acting via the PI3K/AKT pathway to attenuate renal injury, inhibit glomerular basement membrane thickening, and achieve podocyte homeostasis in diabetic nephropathy.

Integrated Network Pharmacology Analysis and Pharmacological Evaluation to Explore the Active Components and Mechanism of Abelmoschus manihot (L.) Medik. on Renal Fibrosis

Background

Renal fibrosis is a common pathological outcome of chronic kidney diseases (CKD) that is considered as a global public health issue with high morbidity and mortality. The dry corolla of Abelmoschus manihot (L.) Medik. (AMC) has been used for chronic nephritis in clinic and showed a superior effect in alleviating proteinuria in CKD patients to losartan. However, the effective components and underlying mechanism of AMC in the treatment of renal fibrosis have not been systematically clarified.

Methods

Based on drug-likeness evaluation, oral bioavailability prediction and compound contents, a systematic network pharmacology analysis was conducted to predict the active ingredients. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway analysis and protein–protein interaction analysis were applied to predict the potential pathway and target of AMC against renal fibrosis. The formula of component contribution index (CI) based on the algorithm was used to screen the principal active compounds of AMC in the treatment of renal fibrosis. Finally, pharmacological evaluation was conducted to validate the protective effect and primary predicted mechanism of AMC in the treatment of renal fibrosis on a 5/6 nephrectomy mice model.

Results

Fourteen potential active components of AMC possessing favorable pharmacokinetic profiles and biological activities were selected and hit by 17 targets closely related to renal fibrosis. Quercetin, caffeic acid, 9.12-octadecadienoic acid, and myricetin are recognized as the more highly predictive components as their cumulative contribution rate reached 85.86%. The AMC administration on 5/6 nephrectomy mice showed a protective effect on kidney function and renal fibrosis. The hub genes analysis revealed that AMC plays a major role in inhibiting epithelial-to-mesenchymal transition during renal fibrosis.

Conclusion

Our results predicted active components and potential targets of AMC for the application to renal fibrosis from a holistic perspective, as well as provided valuable direction for further research of AMC and improved comprehension of renal fibrosis pathogenesis.

Total Flavones of Abelmoschus manihot Remodels Gut Microbiota and Inhibits Microinflammation in Chronic Renal Failure Progression by Targeting Autophagy-Mediated Macrophage Polarization

Background

Recently, progression of chronic renal failure (CRF) has been closely associated with gut microbiota dysbiosis and intestinal metabolite-derived microinflammation. In China, total flavones of Abelmoschus manihot (TFA), a component of Abelmoschus manihot, has been widely used to delay CRF progression in clinics for the past two decades. However, the overall therapeutic mechanisms remain obscure. In this study, we designed experiments to investigate the renoprotective effects of TFA in CRF progression and its underlying mechanisms involved in gut microbiota and microinflammation, compared with febuxostat (FEB), a potent non-purine selective inhibitor of xanthine oxidase.

Methods

In vivo, the CRF rat models were induced by uninephrectomy, potassium oxonate, and proinflammatory diet, and received either TFA suspension, FEB, or vehicle after modeling for 28 days. In vitro, the RAW 264.7 cells were exposed to lipopolysaccharide (LPS) with or without TFA or FEB. Changes in parameters related to renal injury, gut microbiota dysbiosis, gut-derived metabolites, and microinflammation were analyzed in vivo. Changes in macrophage polarization and autophagy and its related signaling were analyzed both in vivo and in vitro.

Results

For the modified CRF model rats, the administration of TFA and FEB improved renal injury, including renal dysfunction and renal tubulointerstitial lesions; remodeled gut microbiota dysbiosis, including decreased Bacteroidales and Lactobacillales and increased Erysipelotrichales; regulated gut-derived metabolites, including d-amino acid oxidase, serine racemase, d-serine, and l-serine; inhibited microinflammation, including interleukin 1β (IL1β), tumor necrosis factor-α, and nuclear factor-κB; and modulated macrophage polarization, including markers of M1/M2 macrophages. More importantly, TFA and FEB reversed the expression of beclin1 (BECN1) and phosphorylation of p62 protein and light chain 3 (LC3) conversion in the kidneys by activating the adenosine monophosphate-activated protein kinase-sirtuin 1 (AMPK-SIRT1) signaling. Further, TFA and FEB have similar effects on macrophage polarization and autophagy and its related signaling in vitro.

Conclusion

In this study, we demonstrated that TFA, similar to FEB, exerts its renoprotective effects partially by therapeutically remodeling gut microbiota dysbiosis and inhibiting intestinal metabolite-derived microinflammation. This is achieved by adjusting autophagy-mediated macrophage polarization through AMPK-SIRT1 signaling. These findings provide more accurate information on the role of TFA in delaying CRF progression.

Traditional Uses, Chemical Constituents, Biological Properties, Clinical Settings, and Toxicities of Abelmoschus manihot L.: A Comprehensive Review

Abelmoschus manihot, an annual herbal flowering plant, is widely distributed throughout eastern Europe and in temperate and subtropical regions of Asia. Its flowers have been traditionally used for the treatment of chronic kidney disease in China. Currently, more than 128 phytochemical ingredients have been obtained and identified from the flowers, seeds, stems, and leaves of A. manihot. The primary components are flavonoids, amino acids, nucleosides, polysaccharides, organic acids, steroids, and volatile oils. A. manihot and its bioactive constituents possess a plethora of biological properties, including antidiabetic nephropathy, antioxidant, antiadipogenic, anti-inflammatory, analgesic, anticonvulsant, antidepressant, antiviral, antitumor, cardioprotective, antiplatelet, neuroprotective, immunomodulatory, and hepatoprotective activities, and have effects on cerebral infarction, bone loss, etc. However, insufficient utilization and excessive waste have already led to a rapid reduction of resources, meaning that a study on the sustainable use of A. manihot is urgent and necessary. Moreover, the major biologically active constituents and the mechanisms of action of the flowers have yet to be elucidated. The present paper provides an early and comprehensive review of the traditional uses, chemical constituents, pharmacological activities, and pharmaceutical, quality control, toxicological, and clinical settings to emphasize the benefits of this plant and lays a solid foundation for further development of A. manihot.

Circ_LARP4 regulates high glucose-induced cell proliferation, apoptosis, and fibrosis in mouse mesangial cells

The current study aimed to investigate the role and underlying mechanisms of circ_LARP4 in diabetic nephropathy (DN). Here, mouse mesangial cells (SV40-MES13) were cultured with 30 mM glucose to establish a DN cellular model. The qRT-PCR results indicated that circ_LARP4 expression was downregulated in the DN cellular model compared to that in the control cells. As determined by an MTT assay, circ_LARP4 overexpression via the circ_LARP4 overexpression (OE) plasmids inhibited the cell proliferation rate. As determined by an Annexin V/PI kit and flow cytometry, circ_LARP4 overexpression increased the cell apoptosis rate. As measured by Western blot, circ_LARP4 overexpression enhanced BAX expression but reduced Bcl-2 expression, also suggesting an enhancement of cell apoptosis. Moreover, regarding cell fibrosis, circ_LARP4 overexpression reduced the mRNA levels of fibrosis markers, including fibronectin, collagen I and collagen IV. Interestingly, miR-424 was found to be reduced in the DN cellular model after transfection with the circ_LARP4 OE plasmids. In addition, restoration of miR-424 expression with the miR-424 mimics reversed the negative effects of circ_LARP4 overexpression on cell proliferation and fibrosis. In conclusion, circ_LARP4 was lower in the DN cellular model than in normal cells, and circ_LARP4 overexpression resulted in decreased cell proliferation and cell fibrosis but increased cell apoptosis in the DN cellular model by sponging miR-424.

Rapamycin improves renal injury induced by Iodixanol in diabetic rats by deactivating the mTOR/p70S6K signaling pathway

AIMS

To study how to effectively prevent or reduce renal injury caused by contrast agents in diabetic patients.

MAIN METHODS

Sprague Dawley (SD) rats were bred with a high-fat diet for eight weeks, then intraperitoneally injected with Streptozotocin (STZ) to prepare the diabetes model. Rats were treated with Iodixanol to prepare a contrast-induced acute kidney injury (CIAKI) model. Moreover, 3-methyladenine (3-MA), an autophagy inhibitor, was administrated to diabetic rats with or without Rapamycin treatment. Serum creatinine (SCr) and blood urea nitrogen (BUN) were examined using Biochemical detector. Kidney injury molecule-1 (KIM-1), N-acetyl-β-D-amino glycosidase (NAG) in urine, inflammatory and oxidative stress factors in serum were determined by ELISA. The expression level of ROS was quantified by immunofluorescence (IF). The protein expressions of Bax, BCl-2, LC3, Beclin1, mTOR and p70S6K in renal tissue were detected by Western blot.

KEY FINDINGS

Rapamycin was demonstrated to improve renal injury induced by Iodixanol diabetic rats, decrease the levels of SCr, BUN, KIM-1, NAG, improve renal functions, reduce inflammatory response and oxidative stress injury, down-regulate Bax, while up-regulate BCl-2 and inhibit apoptosis. Moreover, Rapamycin could inhibit the phosphorylation of mTOR/p70S6K pathway-associated proteins, activate autophagy and increase the levels of LC3 and Beclin1. After treatment with 3MA, an inhibitor of mTOR/p70S6K signaling pathway, the protective effects of Rapamycin on CIAKI were weakened.

SIGNIFICANCE

Rapamycin can alleviate renal injury induced by Iodixanol diabetic rats, and its regulatory mechanisms may be related to the regulation of mTOR/p70S6K signaling pathway and the activating autophagy.

Huangkui Capsule Ameliorates Renal Fibrosis in a Unilateral Ureteral Obstruction Mouse Model Through TRPC6 Dependent Signaling Pathways

Renal fibrosis is the final common pathological manifestation of almost all progressive chronic kidney diseases (CKD). Transient receptor potential canonical (TRPC) channels, especially TRPC3/6, were proposed to be essential therapeutic targets for kidney injury. Huangkui capsule (HKC), an important adjuvant therapy for CKD, showed superior efficacy for CKD at stages 1–2 in clinical practice. However, its anti-fibrotic effect and the underlying mechanisms remain to be investigated. In the present study, we evaluated the efficacy of HKC on renal fibrosis in a mouse model of unilateral ureteral obstruction (UUO) and explored the potential underlying mechanism. Administration of HKC by intragastric gavage dose-dependently suppressed UUO-induced kidney injury and tubulointerstitial fibrosis. Similarly, HKC suppressed the expression level of α-smooth muscle actin (α-SMA), increased the expression of E-cadherin, and suppressed the mRNA expression of a plethora of proinflammatory mediators that are necessary for the progression of renal fibrosis. Mechanistically, HKC suppressed both canonical and non-canonical TGF-β signaling pathways in UUO mice as well as the TRPC6/calcineurin A (CnA)/nuclear factor of activated T cells (NFAT) signaling axis. In addition, TRPC6 knockout mice and HKC treated wild type mice displayed comparable protection on UUO-triggered kidney tubulointerstitial injury, interstitial fibrosis, and α-SMA expression. More importantly, HKC had no additional protective effect on UUO-triggered kidney tubulointerstitial injury and interstitial fibrosis in TRPC6 knockout mouse. Further investigation demonstrated that HKC could directly suppress TRPC3/6 channel activities. Considered together, these data demonstrated that the protective effect of HKC on renal injury and interstitial fibrosis is dependent on TRPC6, possibly through direct inhibition of TRPC6 channel activity and indirect suppression of TRPC6 expression.

Chemical constituents, clinical efficacy and molecular mechanisms of the ethanol extract of Abelmoschus manihot flowers in treatment of kidney diseases

Abelmoschus manihot, also called as “Huangkui” in Chinese, is an annual flowering herb plant in the family of Malvaceae. As a traditional Chinese medicine, the ethanol extract of the flower in Abelmoschus manihot is made as Huangkui capsule and has been used for medication of the patients with kidney diseases. Its efficacy in clinical symptoms is mainly improving renal function and reducing proteinuria among the patients with chronic kidney disease, diabetic kidney disease or IgA nephropathy. The possible mechanism of Huangkui capsule treatment in kidney diseases may include reducing inflammation and anti‐oxidative stress, improving immune response, protecting renal tubular epithelial cells, ameliorating podocyte apoptosis, glomerulosclerosis and mesangial proliferation, as well as inhibiting renal fibrosis. In this review, we first described chemical constituents and pharmacokinetic characteristics in ethanol extract of the flower of Abelmoschus manihot. We then summarized the clinical and epidemiological relevancies of kidney diseases particularly in the mainland of China and discussed the possible molecular mechanisms of Huangkui capsule in the treatment of kidney diseases. Finally, we prospected further research on cellular and molecular mechanisms and application of this Chinese natural medicine in kidney diseases.

Therapeutic Effect of Abelmoschus manihot on Type 2 Diabetic Nonproliferative Retinopathy and the Involvement of VEGF

Objective

To evaluate the efficacy of Abelmoschus manihot in treating type 2 diabetic nonproliferative retinopathy.

Methods

It was a randomized controlled clinical trial. The recruited eighty subjects with type 2 diabetic nonproliferative retinopathy were randomly divided into treatment group and control group. The two groups received basic treatments including control of blood glucose, blood pressure and blood lipid, management of diet, exercise and health education, and monitoring of relevant indicators. Additionally, the treatment group was given oral administration of Abelmoschus manihot. All subjects were followed up on monthly basis for consecutive six months. The related parameters including diabetic retinopathy (DR) incidence rates, “Early Treatment Diabetic Retinopathy Study” (ETDRS) vision scores, retinal thicknesses in macular region, serum vascular endothelial growth factor (VEGF) levels, and biochemical indicators of both groups before and after treatment were accurately collected and statistically analyzed.

Results

There were no significant differences of DR severity levels, ETDRS vision scores, macular retinal thicknesses such as cube average thickness (CAT), central subfield thickness (CST), and cube volume (CV), and serum VEGF levels between two groups before treatment. Meanwhile, there were no significant differences of demographic characteristics, case terminations, blood glucose, blood lipid, blood pressure, biochemical indicators of hepatorenal function, hypoglycemic drugs, hypotensive drugs, and other basic treatments between two groups during six months treatment. The present study suggested that the remission rate of DR and the ETDRS vision score in the treatment group were significantly higher than those of the control group (remission rate: 25.4% vs 9.3%, P=0.01; ETDRS score: 78 (72, 82) vs 72 (67, 80), P=0.0002) while the progression rate of DR in the treatment group was significantly lower than that of the control group (progression rate: 4.2% vs 18.7%, P=0.007) after six months treatment. In addition, the CAT, CST, CV, and serum VEGF levels of the treatment group were significantly improved after the treatment (CAT: 286 (278, 302) vs 282 (270, 295) μm, P < 0.0001; CST: 251 (239, 274) vs 248 (235, 265) μm, P < 0.0001; CV: 10.3 (10.0, 10.9) vs 10.1 (9.7, 10.6) mm³, P < 0.0001; VEGF: 0.21 (0.14, 0.58) vs 0.16 (0.10, 0.23) ng/ml, P=0.0026), while there were no significant differences of the control group before and after treatment (CAT: 287 (279, 294) vs 287 (279, 295) μm, P=0.27; CST: 250 (240, 266) vs 252 (238, 266) μm, P=0.72; CV: 10.4 (10.1, 10.6) vs 10.4 (10.1, 10.7) mm³, P=0.53; VEGF: 0.21 (0.13, 0.66) vs 0.23 (0.12, 0.64) ng/ml, P=0.85).

Conclusion

The study offered the novel evidence for the therapeutic effect of Abelmoschus manihot on type 2 diabetic nonproliferative retinopathy, which was associated with improved VEGF. This trial is registered with ChiCTR1800019292.

LINC00462 is involved in high glucose-induced apoptosis of renal tubular epithelial cells via AKT pathway

New evidences suggest that long non-coding RNAs (lncRNAs) may play important roles in a variety of kidney diseases, including diabetic nephropathy (DN). Our present study investigated the potential function of LINC00462 in high glucose (HG)-induced apoptosis of renal tubular epithelial cells (RTEC) and to determine the underlying mechanism. The expression of LINC00462 in renal biopsy tissues was examined using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Then, a loss of function assay was performed to determine the protective effect of LINC00462 in HG-induced RTEC damage. In addition, the downstream signaling pathway of LINC00462 was also investigated. The qRT-PCR results showed that the expression of LINC00462 was significantly up-regulated in renal biopsies from DN patients. At the same time, LINC00462 was enhanced in a glucose concentration- and time-dependent manner in human kidney (HK-2 and HKC) cells subjected to HG treatment. The knockdown of LINC00462 improved the significantly reduced cell viability of HG treatment, decreased HG-induced reactive oxygen species (ROS) and malondialdehyde levels, and up-regulated the response of antioxidant systems to ROS by increasing superoxide dismutase and catalase levels. In addition, knockdown of LINC00462 inhibited HG-induced cell apoptosis and affected the expression of apoptosis-related proteins. Most importantly, we found that knockdown of LINC00462 enhanced the expression of p-AKT. Moreover, AKT-specific inhibitor LY294002 restored the effect of LINC00462 knockdown on apoptosis. In conclusion, our study demonstrated that knockdown of LINC00462 can ameliorate oxidative stress and apoptosis in HG-induced RTEC by activating the AKT pathway, suggesting that knockdown of LINC00462 may provide a potential therapeutic approach for DN.

Huangkui capsule alleviates renal tubular epithelial-mesenchymal transition in diabetic nephropathy via inhibiting NLRP3 inflammasome activation and TLR4/NF-κB signaling

BACKGROUND

Huangkui capsule (HKC), an anti-inflammatory Chinese modern patent medicine, has been now widely applied to the clinical therapy of diabetic nephropathy (DN). However, the overall therapeutic mechanisms in vivo are still unclear. Renal tubular epithelial-to-mesenchymal transition (EMT) is one of the major pathogenesis of renal interstitial fibrosis in DN. Recently, the physiological roles of NLRP3 inflammasome activation and toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signaling are closely linked to EMT. But, it remains elusive whether HKC regulates renal tubular EMT in vivo through targeting NLRP3 inflammasome activation and TLR4/NF-κB signaling in the kidneys.

PURPOSE

This study thereby aimed to clarify the therapeutic effects of HKC on renal tubular EMT in DN and its underlying mechanisms in vivo, compared to rapamycin (RAP).

METHODS

Thirty-two rats were randomly divided into 4 groups: the Sham group, the Vehicle group, the HKC group and the RAP group. The early DN rat models were induced by unilateral nephrectomy combined with intraperitoneal injection of streptozotocin, and administered with HKC suspension or RAP suspension or vehicle after modeling for 4 weeks. Changes in the incipient renal lesions-related parameters in urine and blood were analyzed, respectively. Renal interstitial tissues were isolated for histomorphometry, immunohistochemistry and Western blotting at sacrifice.

RESULTS

For the early DN rat models, HKC at the suitable dose of 2 g/kg/day ameliorated the general condition and biochemical parameters partially including kidney weight (KW), urinary albumin (UAlb), serum creatinine (Scr) and serum albumin (Alb), attenuated renal tubular EMT significantly and inhibited the activation of NLRP3 inflammasome in the kidneys obviously, which was superior to RAP generally. In addition to these, HKC also suppressed TLR4/NF-κB signaling in the kidneys of the DN model rats accurately, which was different from RAP specifically.

CONCLUSION

The results of this study further indicated that HKC, different from RAP, can alleviate renal tubular EMT in the DN model rats, likely by inhibiting NLRP3 inflammasome activation and TLR4/NF-κB signaling in the kidneys. Our findings thus provide the more accurate information in vivo about a clinical value of HKC, a traditional anti-inflammatory phytomedicine, in the treatment of the early DN patients.

Astragaloside IV ameliorates high glucose‑induced renal tubular epithelial‑mesenchymal transition by blocking mTORC1/p70S6K signaling in HK‑2 cells

Astragaloside IV (AST) is the major active saponin in Astragalus membranaceus and, reportedly, has a variety of pharmacological activities. However, the potential of AST to ameliorate high glucose‑mediated renal tubular epithelial‑mesenchymal transition (EMT) remains undetermined. The aim of the present research was to explore the effect and mechanism of AST in EMT of renal tubular epithelial cells, as an underlying mechanism of renal fibrosis and a vital feature involved in diabetic nephropathy. The effect of AST on the EMT of renal tubular epithelial cells (HK‑2) stimulated by high glucose was investigated and it was attempted to elucidate the potential underlying mechanism. The expression of E‑cadherin and α‑smooth muscle actin were determined by western blotting and immunofluorescence assays. The expression of the mammalian target of rapamycin complex 1 (mTORC1)/ ribosomal protein S6 kinase β‑1 (p70S6K) signaling pathway and protein levels of four transcriptional factors (snail, slug, twist and zinc finger E‑box‑binding homeobox 1) were also determined by western blotting. Additionally, extracellular matrix components, including fibronectin (FN) and collagen type IV (Col IV) were detected by ELISA. The results suggested that the EMT of HK‑2 cells and the mTORC1/p70S6K pathway were activated by high glucose. The expression of snail and twist in HK‑2 cells was elevated by high glucose. Furthermore, extracellular matrix components, FN and Col IV, were increased in HK‑2 cells cultured with high glucose. In turn, treatment with AST reduced EMT features in HK‑2 cells, inhibited mTORC1/p70S6K pathway activation, downregulated expression of snail and twist, and reduced secretion of FN and Col IV. In summary, the findings suggested that AST ameliorates high glucose‑mediated renal tubular EMT by blocking the mTORC1/p70S6K signaling pathway in HK‑2 cells.

Salvia miltiorrhiza protects against diabetic nephropathy through metabolome regulation and wnt/β-catenin and TGF-β signaling inhibition

Diabetic nephropathy (DN) is a complication of diabetes that is caused by uncontrolled high blood sugar. It has been reported that Salvia miltiorrhiza (SM) possesses the ability to prevent kidney damage, although the mechanisms remain unclear. The study was to investigate whether and how SM improved DN injury via regulation of metabolome and the molecular mechanisms. In this study, SD rats were fed a high glucose / high fat diet accompanied by 0.5% glucose water. Three weeks later, the rats were given one intraperitoneal injection of 30 mg/kg STZ each day for three days for DN model. The biochemical indicators and metabolomics of plasma, urine and renal tissue were analyzed. Then the western blotting analysis of renal tissue and glomerular mesangial cells were investigated. The results showed that Salvia miltiorrhiza extracts improved the renal injury and regulation of abnormal glycolipid metabolism. The metabolites in serum, urine and renal tissues have been changed significantly. The involved metabolic pathways mainly include phospholipid, arachidonic acid, and pyrimidine metabolisms. Meanwhile, SM inhibited the relative expression levels of wnt4, β-catenin and TGF-β in renal tissue and high-glucose induced glomerular mesangial cells.