Protective role of Astragaloside IV in chronic glomerulonephritis by activating autophagy through PI3K/AKT/AS160 pathway

Oral bacteriome and mycobiome of patients with idiopathic membranous nephropathy with different tongue coatings treated with a Chinese herbal formula

ETHNOPHARMACOLOGICAL RELEVANCE

Moshen Fuyuan Formula (MSFY) is one of the representative Chinese medicine compound for Idiopathic membranous nephropathy (IMN), that originate from Fang Ji Huang Qi decoction in the Han dynasty. IMN is usually accompanied by different tongue coatings in traditional Chinese medicine (TCM), and tongue microorganisms are important factors affecting the formation of the tongue coating. Recently, oral microbiomes, including bacteria and fungi, have been identified as pivotal factors that contribute to disease development. However, the regulation of oral microbiomes by MSFY has not been defined.

AIM OF THE STUDY

In this work, we explore the characteristics of oral bacteria and fungi in IMN patients with different tongue coatings, and clarify the therapeutic effect of MSFY based on oral microbiome.

MATERIALS AND METHODS

We enrolled 24 patients with IMN, including 11 with white tongue (IMN-W) and 13 with yellow tongue (IMN-Y), and recruited an additional 10 healthy individuals. Patients with IMN were treated with the MSFY. The oral bacteriome and fungi before and after treatment were detected using full-length 16S rRNA and internal transcribed spacer gene sequencing.

RESULTS

The therapeutic effect of MSFY on patients with yellow tongue coating was more significant than that on patients with white tongue coating. In terms of oral bacteriome, Campylobacter bacteria were enriched in patients with yellow tongue and could be a promising biomarker for yellow coating. Enrichment of Veillonella parvula_A may partially account for the therapeutic effect of MSFY. As for oral fungi, Malassezia globosa was enhanced in patients with IMN-W and reduced in patients with IMN-Y. Notably, it was reduced by MSFY. We also found that mycobiome-bacteriome interactions were highly complex and dynamic in patients with IMN.

CONCLUSION

The regulation of the dynamic balance between oral fungi and bacteria by MSFY contributes to the treatment of IMN. This study determined the oral bacteriome and mycobiome of patients with IMN with different tongue coatings before and after MSFY treatment, which aids in promoting personalized treatment in clinical TCM and provides direction for investigating the mechanism of Chinese herbal medicines.

The role of PI3K/Akt signaling pathway in chronic kidney disease

Chronic kidney disease (CKD), including chronic glomerulonephritis, IgA nephropathy and diabetic nephropathy, are common chronic diseases characterized by structural damage and functional decline of the kidneys. The current treatment of CKD is symptom relief. Several studies have reported that the phosphatidylinositol 3 kinases (PI3K)/protein kinase B (Akt) signaling pathway is a pathway closely related to the pathological process of CKD. It can ameliorate kidney damage by inhibiting this signal pathway which is involved with inflammation, oxidative stress, cell apoptosis, epithelial mesenchymal transformation (EMT) and autophagy. This review highlights the role of activating or inhibiting the PI3K/Akt signaling pathway in CKD-induced inflammatory response, apoptosis, autophagy and EMT. We also summarize the latest evidence on treating CKD by targeting the PI3K/Akt pathway, discuss the shortcomings and deficiencies of PI3K/Akt research in the field of CKD, and identify potential challenges in developing these clinical therapeutic CKD strategies, and provide appropriate solutions.

Investigation of the Metabolism of Astragaloside IV in a Puromycin-Damaged Rat Model by UPLC-Q-TOF-MS/MS Analysis

Astragaloside IV (AS-IV) has been shown to provide renal protection in various kidney injury models. However, the metabolic profile variation of AS-IV in pathological models in vivo is not well established. This study aims to explore the metabolic pathway of AS-IV in vivo in the classical puromycin aminonucleoside (PAN)-induced kidney injury in a rat model. Twelve Wistar rats were randomly divided into the AS-IV (CA) and the PAN+AS-IV (PA) treatment groups. PAN was injected by a single tail intravenous (i. v.) injection at 5 mg/100 g body weight, and AS-IV was administered intragastrically (i. g.) at 40 mg/kg for 10 days. Fecal samples of these rats were collected, and metabolites of AS-IV were detected by ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) to explore the AS-IV metabolic pathway. The metabolic differences between the AS-IV and PAN+AS-IV groups were compared. A total of 25 metabolites were detected, and deglycosylation, deoxygenation, and methyl oxidation were found to be the main metabolic pathways of AS-IV in vivo. The abundance of most of these metabolites in the PAN+AS-IV group was lower than that in the AS-IV treatment group, and differences for seven of them were statistically significant. Our study indicates that AS-IV metabolism is affected in the PAN-induced kidney injury rat model.

Pharmacological potential of Astragali Radix for the treatment of kidney diseases

BACKGROUND

With the increasing prevalence of hypertension, diabetes, and obesity, the incidence of kidney diseases is also increasing, resulting in a serious public burden. Conventional treatments for kidney diseases have unsatisfactory effects and are associated with adverse reactions. Traditional Chinese medicines have good curative effects and advantages over conventional treatments for preventing and treating kidney diseases. Astragali Radix is a Chinese herbal medicine widely used to treat kidney diseases.

PURPOSE

To review the potential applications and molecular mechanisms underlying the renal protective effects of Astragali Radix and its components and to provide direction and reference for new therapeutic strategies and future research and development of Astragali Radix.

STUDY DESIGN AND METHODS

PubMed, Google Scholar, and Web of Science were searched using keywords, including "Astragali Radix," "Astragalus," "Astragaloside IV" (AS-IV), "Astragali Radix polysaccharide" (APS), and "kidney diseases." Reports on the effects of Astragali Radix and its components on kidney diseases were identified and reviewed.

RESULTS

The main components of Astragali Radix with kidney-protective properties include AS-IV, APS, calycosin, formononetin, and hederagenin. Astragali Radix and its active components have potential pharmacological effects for the treatment of kidney diseases, including acute kidney injury, diabetic nephropathy, hypertensive renal damage, chronic glomerulonephritis, and kidney stones. The pharmacological effects of Astragali Radix are manifested through the inhibition of inflammation, oxidative stress, fibrosis, endoplasmic reticulum stress, apoptosis, and ferroptosis, as well as the regulation of autophagy.

CONCLUSION

Astragali Radix is a promising drug candidate for treating kidney diseases. However, current research is limited to animal and cell studies, underscoring the need for further verifications using high-quality clinical data.

GDF15 Interference Regulates Proliferation, Inflammation, and Autophagy of Lipopolysaccharide-induced Mesangial Cells by Inhibiting PI3K/ AKT/mTOR Signaling

BACKGROUND

Chronic glomerulonephritis (CGN) is a primary glomerular disease. As a circulating protein, growth and differentiation factor 15 (GDF15) participates in a variety of biological processes.

OBJECTIVE

We aimed to investigate the role of GDF15 in CGN.

METHODS

HBZY-1 cells were induced by lipopolysaccharide (LPS). Cell viability was detected using a cell counting kit-8 (CCK-8) assay, and a western blot was applied for the detection of GDF15 protein expression. After GDF15 silencing, cell proliferation was evaluated by CCK-8 assay and 5-ethynyl-2'-deoxyuridine (EDU) staining. Enzyme-linked immunosorbent assay (ELISA) kits were used to detect the levels of inflammatory cytokines. Autophagy was assessed by GFP-LC3B assay. Besides, the expression of NF-κB signaling-, autophagy- (LC3II/I, Beclin l and p62) and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling-related proteins were measured by western blot. Afterwards, PI3K agonist 740Y-P was used to clarify whether GDF15 affected LPS-induced HBZY-1 cells via PI3K/AKT/mTOR signaling.

RESULTS

LPS induction increased cell viability and elevated GDF15 expression in HBZY-1 cells. After GDF15 expression depletion, the increased proliferation of LPS-induced HBZY-1 cells was decreased. Additionally, GDF15 knockdown suppressed the release of inflammatory factors in LPS-induced HBZY-1 cells and activated autophagy. Moreover, the PI3K/AKT/ mTOR signal was evidenced to be activated by GDF15 deficiency. The further addition of 740Y-P reversed the impacts of GDF15 deficiency on the proliferation, inflammation, and autophagy of LPS-induced HBZY-1.

CONCLUSION

Collectively, GDF15 downregulation could protect against CGN via blocking PI3K/AKT/mTOR signaling.

Biodegradation of Uric Acid by Bacillus paramycoides-YC02

High serum uric acid levels, known as hyperuricemia (HUA), are associated with an increased risk of developing gout, chronic kidney disease, cardiovascular disease, diabetes, and other metabolic syndromes. In this study, a promising bacterial strain capable of biodegrading uric acid (UA) was successfully isolated from Baijiu cellar mud using UA as the sole carbon and energy source. The bacterial strain was identified as Bacillus paramycoides-YC02 through 16S rDNA sequence analysis. Under optimal culture conditions at an initial pH of 7.0 and 38 °C, YC02 completely biodegraded an initial UA concentration of 500 mg/L within 48 h. Furthermore, cell-free extracts of YC02 were found to catalyze and remove UA. These results demonstrate the strong biodegradation ability of YC02 toward UA. To gain further insight into the mechanisms underlying UA biodegradation by YC02, the draft genome of YC02 was sequenced using Illumina HiSeq. Subsequent analysis revealed the presence of gene1779 and gene2008, which encode for riboflavin kinase, flavin mononucleotide adenylyl transferase, and flavin adenine dinucleotide (FAD)-dependent urate hydroxylase. This annotation was based on GO or the KEEG database. These enzymes play a crucial role in the metabolism pathway, converting vitamin B2 to FAD and subsequently converting UA to 5-hydroxyisourate (HIU) with the assistance of FAD. Notably, HIU undergoes a slow non-enzymatic breakdown into 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and (S)-allantoin. The findings of this study provide valuable insights into the metabolism pathway of UA biodegradation by B. paramycoides-YC02 and offer a potential avenue for the development of bacterioactive drugs against HUA and gout.

Integrating network pharmacology approach and experimental validation to reveal the alleviation of Shenkangning capsule on chronic nephritis

ETHNOPHARMACOLOGICAL RELEVANCE

Shenkangning (SKN), a Chinese patent medicine composed by eight Chinese medicinal herbs, is commonly applied to treat chronic glomerulonephritis (CGN) in clinic. However, its mechanism is still not clear now.

AIM OF THE STUDY

This study is designed to evaluate the SKN-provided alleviation on adriamycin (ADR)-induced nephropathy, to reveal its mechanism by integrating network pharmacology analysis and experimental evidences, and to further find the main drug that makes a major contribution to its efficacy.

MATERIALS AND METHODS

ADR was intravenously injected to mice to induce focal segmental glomerulosclerosis (FSGS). Renal histological evaluation was conducted. The level of urinary protein, and serum amounts of creatinine, urea nitrogen (BUN) and albumin were detected. The potential mechanisms were predicted by network pharmacology analysis and further validated by Real-time polymerase chain reaction (RT-PCR), Western-blot and enzyme-linked immunosorbent assay (ELISA).

RESULTS

SKN (1, 10 g/kg) improved ADR-induced nephropathy in mice. Network pharmacology results predicted that inflammation and oxidative stress were crucially involved in the SKN-provided amelioration on nephropathy. SKN reduced the activation of nuclear factor-κB (NF-κB) and the expression of some pro-inflammatory cytokines, and increased the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the expression of its downstream genes in ADR-induced nephropathy in mice. Furthermore, SKN also restored the reduced expression of both podocin and synaptopodin, which are podocyte-associated proteins. Further results showed that the toxic drug Danfupian (DFP) had no contribution to the SKN-provided alleviation on ADR-induced nephropathy in mice. After integrating the results from evaluating anti-inflammation, anti-oxidant and anti-injury of podocytes in vitro and from comparing the activity of the whole SKN and SKN without Astragali Radix (Huangqi, HQ) in vivo, we found that HQ played a crucial contribution to the SKN-provided amelioration on ADR-induced nephropathy in mice.

CONCLUSION

SKN improved ADR-induced nephropathy through suppressing renal inflammation and oxidative stress injury via abrogating NF-κB activation and activating Nrf2 signaling pathway. HQ played a main contribution to the SKN-provided amelioration on ADR-induced nephropathy.

Review of the pharmacological effects of astragaloside IV and its autophagic mechanism in association with inflammation

Astragalus membranaceus Bunge, known as Huangqi, has been used to treat various diseases for a long time. Astragaloside IV (AS-IV) is one of the primary active ingredients of the aqueous Huangqi extract. Many experimental models have shown that AS-IV exerts broad beneficial effects on cardiovascular disease, nervous system diseases, lung disease, diabetes, organ injury, kidney disease, and gynaecological diseases. This review demonstrates and summarizes the structure, solubility, pharmacokinetics, toxicity, pharmacological effects, and autophagic mechanism of AS-IV. The autophagic effects are associated with multiple signalling pathways in experimental models, including the PI3KI/Akt/mTOR, PI3K III/Beclin-1/Bcl-2, PI3K/Akt, AMPK/mTOR, PI3K/Akt/mTOR, SIRT1–NF-κB, PI3K/AKT/AS160, and TGF-β/Smad signalling pathways. Based on this evidence, AS-IV could be used as a replacement therapy for treating the multiple diseases referenced above.

Zhen-Wu-Tang Induced Mitophagy to Protect Mitochondrial Function in Chronic Glomerulonephritis via PI3K/AKT/mTOR and AMPK Pathways

Chronic glomerulonephritis (CGN) is one of the major causes of end-stage kidney disease. Zhen-wu-tang (ZWT), as a famous Chinese herbal prescription, is widely used in China for CGN therapy in clinic. However, the mechanism of ZWT in CGN has not been fully understood. The present study explored the therapeutic effect and the underlying mechanism of ZWT on mitochondrial function in cationic bovine serum albumin (C-BSA)-induced CGN model rats and tumor necrosis factor (TNF-α)-damaged mouse podocytes. The renal functions were measured by serum creatinine (Scr) and blood urea nitrogen (BUN). Renal pathological changes and ultrastructure of kidney tissues were evaluated by periodic acid-Schiff (PAS) staining and transmission electron microscopy. The levels of antioxidases, including mitochondrial catalase (CAT), superoxide dismutase 2 (SOD2), and peroxiredoxin 3 (PRDX3), in CGN rats were examined by real-time PCR. The mitochondrial functions of podocytes were measured by ATP concentration, mitochondrial membrane potential (MMP), and mitochondrial ROS (mtROS). For mitophagy level detection, the expressions of mitophagy-related proteins, including LC3, p62, heat shock protein 60 (HSP60), and translocase of outer mitochondrial membrane 20 (TOMM20), were measured by Western blot, as the colocation of LC3 and mitochondrial marker COX IV were evaluated by immunofluorescence. Our results manifested that ZWT ameliorated CGN model rats by a remarkable decrease in Scr and BUN, inhibition of mesangial matrix proliferation, protection against foot processes fusion, and basement membrane thickening. More importantly, ZWT protected against mitochondrial dysfunction by increasing the expressions of CAT, SOD2, and PRDX3 in CGN model rats, increased ATP content and MMP in podocytes, and decreased excessive mtROS. Furthermore, ZWT induced mitophagy in CGN through increasing the expression of LC3, and decreasing p62, HSP60, TOMM20, and ZWT also enhanced the colocation of LC3 to the mitochondria. We found that ZWT inhibited the PI3K/AKT/mTOR pathway, which could be disturbed by PI3K inhibitor LY294002 and agonist insulin-like growth factor 1. Moreover, ZWT reversed the inhibition of the AMPK pathway in CGN. Overall, ZWT ameliorated renal mitochondrial dysfunction probably by inducing mitophagy via the PI3K/AKT/mTOR and AMPK pathways.

Astragaloside IV Alleviates Intestinal Barrier Dysfunction via the AKT-GSK3β-β-Catenin Pathway in Peritoneal Dialysis

Background and aims: Long-term peritoneal dialysis (PD) causes intestinal dysfunction, including constipation, diarrhea, or enteric peritonitis. However, the etiology and pathogenesis of these complications are still unclear and there are no specific drugs available in the clinic. This study aims to determine whether Astragaloside IV (AS IV) has therapeutic value on PD-induced intestinal epithelial barrier dysfunction in vivo and in vitro.

Methods: We established two different long-term PD treatment mice models by intraperitoneally injecting 4.25% dextrose-containing peritoneal dialysis fluid (PDF) in uremia mice and normal mice, which were served as controls. In addition, PDF was applied to T84 cells in vitro. The therapeutic effects of AS IV on PD-induced intestinal dysfunction were then examined by histopathological staining, transmission electron microscopy, western blotting, and reverse transcription polymerase chain reaction. The protein levels of protein kinase B (AKT), glycogen synthase kinase 3β (GSK-3β) and β-catenin were examined after administration of AS IV.

Results: In the present study, AS IV maintained the intestinal crypt, microvilli and desmosome structures in an orderly arrangement and improved intestinal epithelial permeability with the up-regulation of tight junction proteins in vivo. Furthermore, AS IV protected T84 cells from PD-induced damage by improving cell viability, promoting wound healing, and increasing the expression of tight junction proteins. Additionally, AS IV treatment significantly increased the levels of phosphorylation of AKT, inhibited the activity GSK-3β, and ultimately resulted in the nuclear translocation and accumulation of β-catenin.

Conclusion: These findings provide novel insight into the AS IV-mediated protection of the intestinal epithelial barrier from damage via the AKT-GSK3β-β-catenin signal axis during peritoneal dialysis.

Protective Effects of Astragaloside IV on Uric Acid-Induced Pancreatic β-Cell Injury through PI3K/AKT Pathway Activation

Background

Elevated uric acid (UA) has been found to damage pancreatic β-cell, promote oxidative stress, and cause insulin resistance in type 2 diabetes (T2D). Astragaloside IV (AS-IV), a major active monomer extracted from Astragalus membranaceus (Fisch.) Bunge. which belongs to TRIB. Galegeae (Br.) Torrey et Gray, Papilionaceae, exhibits various activities in a pathophysiological environment and has been widely employed to treat diseases. However, the effects of AS-IV on UA-induced pancreatic β-cell damage need to be investigated and the associating mechanism needs to be elucidated. This study was designed to determine the protective effects and underlying mechanism of AS-IV on UA-induced pancreatic β-cell dysfunction in T2D.

Methods

UA-treated Min6 cells were exposed to AS-IV or wortmannin. Thereafter, the 3-(45)-dimethylthiahiazo(-z-y1)-35-di-phenytetrazoliumromide (MTT) assay and flow cytometry were employed to determine the effect of AS-IV on cell proliferation and apoptosis, respectively. Insulin secretion was evaluated using the glucose-stimulated insulin secretion (GSIS) assay. Finally, western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to determine the effect of AS-IV on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway in UA-treated cells.

Results

AS-IV had no cytotoxic effects on Min6 cells. UA significantly suppressed Min6 cell growth, promoted cell apoptosis, and enhanced caspase-3 activity; however, AS-IV abolished these effects in a dose-dependent manner. Further, decreased insulin secretion was found in UA-treated Min6 cells compared to control cells, and the production of insulin was enhanced by AS-IV in a dose-dependent manner. AS-IV significantly increased phosphorylated (p)-AKT expression and the ratio of p-AKT/AKT in Min6 cells exposed to UA. No evident change in AKT mRNA level was found in the different groups. However, the effects of AS-IV on UA-stimulated Min6 cells were reversed by 100 nM wortmannin.

Conclusion

Collectively, our data suggest that AS-IV protected pancreatic β-cells from UA-treated dysfunction by activating the PI3K/AKT pathway. Such findings suggest that AS-IV may be an efficient natural agent against T2D.

Acidic Stigma maydis polysaccharides protect against podocyte injury in membranous nephropathy by maintenance of glomerular filtration barrier integrity and gut-kidney axis

MN mice models were induced by C-BSA, and we found that acidic stigma maydis polysaccharides  maintained the integrity of the glomerular filtration barrier by promoting slit diaphragm proteins expression and PI3K/AKT signaling.

Structural modulation of gut microbiota during alleviation of experimental passive Heymann nephritis in rats by a traditional Chinese herbal formula

BACKGROUND

Jianpi-Qushi-Heluo formula (JQHF) has been used to treat idiopathic membranous nephropathy (IMN) in hospitals for many years.

PURPOSE

Elucidating the protective effect and exploring the potential mechanism of JQHF against IMN.

METHODS

Passive Heymann nephritis (PHN) was induced in rats by a single tail vein injection of anti-Fx1A antiserum. Then, the animals were treated with JQHF at 16.2 g/kg or 32.4 g/kg, with benzepril (10 mg/kg) as a positive control. Renal function was evaluated by biochemical measurements and pathological testing. Fecal samples were collected before and after treatment to analyze the gut microbiota composition by shotgun whole metagenome sequencing.

RESULTS

JQHF exhibited potent efficacy in ameliorating PHN at both doses, as revealed by decreasing the deposition of IgG and C5b-9, relieving podocyte injury, and reducing glomerular and tubular cell apoptosis. The lower dose was corresponding to the clinical dosage and showed better therapeutic effects than the higher dose. Metagenomic analysis showed that gavage with 16.2 g/kg of JQHF shifted the structure of the gut microbiota in PHN rats and significantly increased the relative abundances of Prevotella copri, Lactobacillus vaginalis and Subdoligranulum variabile. Particularly, S. variabile was strongly negatively correlated with serum levels of TC and TG, the deposition of IgG and C5b-9, and apoptosis of glomerular cells.

CONCLUSIONS

The JQHF is an effective agent for the treatment of experimental PHN. The PHN-allevating effect of JQHF is associated with specific alternation of gut microbiota.