[Mechanism of traditional Chinese medicine in regulating NLRP3 inflammasomes to alleviate renal interstitial fibrosis in diabetic nephropathy: a review].

Diabetic nephropathy(DN), a progressive chronic kidney disease(CKD) induced by diabetes mellitus, is the main cause of end-stage renal disease. Renal interstitial fibrosis(RIF) is an irreversible factor in the progression and deterioration of the renal function in DN. Chronic inflammation has become a key link in the pathogenesis of DN-RIF. The NOD-like receptor thermal protein domain associated protein 3(NLRP3) inflammasome is an important inflammatory regulator regulated by a variety of signals. It promotes the production of pro-inflammatory cytokines and induces renal inflammatory cell infiltration to participate in the process of renal fibrosis, demonstrating a complex mechanism of action. In view of the important role of NLRP3 inflammasomes in the prevention and treatment of DN-RIF, a large number of experimental studies have demonstrated that traditional Chinese medicine(TCM) can reduce the inflammation by regulating the pathways involving NLRP3 inflammasome, thereby slowing down the progression of DN-RIF and improving the renal function. This paper reviews the relationship between NLRP3 inflammasomes and DN-RIF, and the research progress in the mechanism of TCM intervention in NLRP3 inflammasomes to alleviate DN-RIF, aiming to provide new ideas for the targeted treatment of DN-RIF.

Demethylzeylasteral protects against renal interstitial fibrosis by attenuating mitochondrial complex I-mediated oxidative stress.

ETHNOPHARMACOLOGICAL RELEVANCE: Renal interstitial fibrosis (RIF) is a main pathological process in chronic kidney disease (CKD). Demethylzeylasteral (DML), a major component of Tripterygium wilfordii Hook. f., has anti-renal fibrosis effects. However, its mechanism of action remains incompletely understood. AIM OF THE STUDY: The present study was designed to comprehensively examine the effects of DML on RIF and the underlying mechanisms. MATERIALS AND METHODS: Pathological experiments were performed to determine the therapeutic effect of DML on a mouse model of UUO-induced RIF. To determine the novel mechanisms underlying the therapeutic effects of DML against RIF, a comprehensive transcriptomics analysis was performed on renal tissues, which was further verified by a series of experiments. RESULTS: Pathological and immunohistochemical staining showed that DML inhibited UUO-induced renal damage and reduced the expression of fibrosis-related proteins in mice. Transcriptomic analysis revealed that the partial subunits of mitochondrial complex (MC) I and II may be targets by which DML protects against RIF. Furthermore, DML treatment reduced mitochondrial reactive oxygen species (ROS) levels, consequently promoting ATP production and mitigating oxidative stress-induced injury in mice and cells. Notably, this protective effect was attributed to the inhibition of MC I activity, suggesting a crucial role for this specific complex in mediating the therapeutic effects of DML against RIF. CONCLUSIONS: This study provides compelling evidence that DML may be used to treat RIF by effectively suppressing mitochondrial oxidative stress injury mediated by MC I. These findings offer valuable insights into the pharmacological mechanisms of DML and its potential clinical application for patients with CKD.

Signaling Pathways Related to Renal Interstitial Fibrosis in Diabetic Kidney Disease Regulated by Traditional Chinese Medicine： A Review / 中国实验方剂学杂志

Diabetic kidney disease （DKD） is a common microvascular complication of diabetics mellitus （DM） and the leading cause of end-stage renal disease （ESRD）. Renal interstitial fibrosis （RIF） is the primary pathological basis for DKD progression to ESRD， which significantly increases the mortality rate of DKD patients and burdens patients and society， and it is thus a clinical problem that needs to be solved urgently. The pathogenesis of RIF is complex and mainly associated with excessive deposition of extracellular matrix （ECM）， epithelial-mesenchymal transition （EMT）， oxidative stress， inflammation， and autophagy. Multiple signaling pathways such as transforming growth factor-β1/Smad （TGF-β1/Smad）， nuclear transcription factor-κB （NF-κB）， p38 mitogen-activated protein kinase （p38 MAPK）， secretory glycoprotein/β-catenin （Wnt/β-catenin）， mammalian target of rapamycin （mTOR）， Janus kinase/signal transducer and activator of transcription （JAK/STAT）， neurogenic site-gap homologous protein （Notch）， and nuclear factor E2-associated factor 2 （Nrf2） mediate the development of RIF， which are currently novel targets for DKD therapy. Due to the complexity of its pathogenesis， the current Western medical treatment mainly focuses on essential treatment to improve metabolism， which has poor efficacy and is difficult to prevent the progression of DKD， so it is significant to find new treatment methods clinically. In recent years， many studies have proved that traditional Chinese medicine can alleviate oxidative stress， inhibit inflammatory response， and regulate cellular autophagy by modulating relevant signaling pathways， so as to treat RIF in DKD， which has the advantages of multi-pathway， multi-targeting， multi-linking， and significant therapeutic efficacy. However， there is still a lack of relevant summary. By reviewing the latest research reports in China and abroad， this article examines the roles of the signaling pathways mentioned above in the occurrence and development of RIF in DKD and the recent research progress in the intervention of RIF in DKD by traditional Chinese medicine via these pathways， aiming to provide new ideas and references for further scientific research and clinical practice.

Ootheca mantidis mitigates renal fibrosis in mice by the suppression of apoptosis via increasing the gut microbe Akkermansia muciniphila and modulating glutamine metabolism.

Renal interstitial fibrosis (RIF), a progressive process affecting the kidneys in chronic kidney disease (CKD), currently lacks an effective therapeutic intervention. Traditional Chinese medicine (TCM) has shown promise in reducing RIF and slowing CKD progression. In this study, we demonstrated the dose-dependent attenuation of RIF by Ootheca mantidis (SPX), a commonly prescribed TCM for CKD, in a mouse model of unilateral ureteral obstruction (UUO). RNA-sequencing analysis suggested that SPX treatment prominently downregulated apoptosis and inflammation-associated pathways, thereby inhibiting the fibrogenic signaling in the kidney. We further found that transplantation of fecal microbiota from SPX-treated mice conferred protection against renal injury and fibrosis through suppressing apoptosis in UUO mice, indicating that SPX ameliorated RIF via remodeling the gut microbiota and reducing apoptosis in the kidneys. Further functional exploration of the gut microbiota combined with fecal metabolomics revealed increased levels of some probiotics, including Akkermansia muciniphila (A. muciniphila), and modulations in glutamine-related amino acid metabolism in UUO mice treated with SPX. Subsequent colonization of A. muciniphila and supplementation with glutamine effectively mitigated cell apoptosis and RIF in UUO mice. Collectively, these findings unveil a functionally A. muciniphila- and glutamine-involved gut-renal axis that contributes to the action of SPX, and provide important clue for the therapeutic potential of SPX, A. muciniphila, and glutamine in combatting RIF.

Shen Qi Wan attenuates renal interstitial fibrosis through upregulating AQP1.

Renal interstitial fibrosis (RIF) is the crucial pathway in chronic kidney disease (CKD) leading to the end-stage renal failure. However, the underlying mechanism of Shen Qi Wan (SQW) on RIF is not fully understood. In the current study, we investigated the role of Aquaporin 1 (AQP1) in SQW on tubular epithelial-to-mesenchymal transition (EMT). A RIF mouse model induced by adenine and a TGF-ß1-stimulated HK-2 cell model were etablished to explore the involvement of AQP 1 in the protective effect of SQW on EMT in vitro and in vivo. Subsequently, the molecular mechanism of SQW on EMT was explored in HK-2 cells with AQP1 knockdown. The results indicated that SQW alleviated kidney injury and renal collagen deposition in the kidneys of mice induced by adenine, increased the protein expression of E-cadherin and AQP1 expression, and decreased the expression of vimentin and α-smooth muscle actin (α-SMA). Similarly, treatmement with SQW-containing serum significantly halted EMT process in TGF-ß1 stimulated HK-2 cells. The expression of snail and slug was significantly upregulated in HK-2 cells after knockdown of AQP1. AQP1 knockdown also increased the mRNA expression of vimentin and α-SMA, and decreased the expression of E-cadherin. The protein expression of vimentin increased, while the expression of E-cadherin and CK-18 significantly decreased after AQP1 knockdown in HK-2 cells. These results revealed that AQP1 knockdown promoted EMT. Furthermore, AQP1 knockdown abolished the protective effect of SQW-containing serum on EMT in HK-2 cells. In sum, SQW attentuates EMT process in RIF through upregulation of the expression of AQP1.

Myo-Inositol Attenuates Renal Interstitial Fibrosis in Obstructive Nephropathy by Inhibiting PI3K/AKT Activation.

Emerging evidence suggests that myo-inositol (MI) has a critical role in reducing renal inflammatory processes and improving podocyte function and preventing diabetes-related renal damage. We aimed to explore the function and underlying workings of MI in renal interstitial fibrosis (RIF). Based on a mouse model, we explored the effect of MI in unilateral ureteral obstruction (UUO) and in transforming growth factor-ß1 (TGF-ß1)-treated HK-2 cells. Pathological changes of the kidney tissues were examined following staining of the tissues with hematoxylin, eosin, and Masson's trichrome. The mRNA quantities of fibrosis markers, fibronectin, α-smooth muscle actin (α-SMA), and collagen I, were analyzed by means of real-time polymerase chain reaction, whereas those of protein levels were assessed with Western blotting. We also determined the expression of collagen I by immunofluorescence, and the levels of phosphorylated phosphotidylinositol-3-kinase and protein kinase B (PI3K/AKT) by Western blot. In vivo, histopathological examination in the UUO mice revealed renal tubular epithelial cell necrosis, inflammatory cell infiltration, and RIF. UUO mice showed higher expression levels of collagen I, fibronectin, α-SMA, pPI3K, and pAKT compared with sham-operated mice. However, MI treatment diminished the pathological alterations of RIF in UUO mice and downregulated the expression of fibrosis markers and phosphorylated PI3K/AKT. In vitro, TGF-ß1 positively influenced the propagation and differentiation of HK-2 cells and upregulated the levels of α-SMA, fibronectin, collagen I, pPI3K, and pAKT, but these became significantly reversed by MI treatment. In conclusion, MI ameliorates RIF, possibly by negatively regulating TGF-ß1-induced epithelial transdifferentiation and PI3K/AKT activation.

Differences in p38-STAT3-S100A11 signaling after the administration of aristolochic acid I and IVa may account for the disparity in their nephrotoxicity.

BACKGROUND: The safety of herbs containing aristolochic acids (AAs) has become a widespread concern. Previous reports indicate that AAs are highly nephrotoxic and carcinogenic, although there are more than 170 analogues of aristolochic acid. Not all AAs have the same degree of nephrotoxicity or carcinogenicity. Previous studies have found that aristolochic acid IVa (AA-IVa), the principal component of AAs within members of the Aristolochiaceae family, especially Asarum, a commonly used herb in China, has essentially no significant nephrotoxicity. However, several studies, including ours, have shown that aristolochic acid I (AA-I) is clearly nephrotoxic. PURPOSE: The focus of the study was to elucidate the molecular mechanism responsible for the difference in nephrotoxicity between the AA-I and AA-IVa. STUDY DESIGN/METHOD: Mice were administered with AA-I or AA-IVa for 22 weeks through the oral route, followed by a 50-week recovery time. The kidney tissues of mice were extracted at the end of 22 weeks. Pathological examination and proteomic detection (tandem mass tagging (TMT) and phosphorylated proteomics) were performed on the kidney tissue to investigate the key signaling pathways and targets of AAs-induced renal interstitial fibrosis (RIF). The key signaling pathways and targets were verified by Western blot (WB), siRNA transfection, and luciferase assays. RESULTS: AA-I caused severe nephrotoxicity, high mortality, and extensive RIF. However, the same AA-IVa dosage exhibited almost no nephrotoxicity and does not trigger RIF. The activation of the p38-STAT3-S100A11 signaling pathway and upregulated expression of α smooth muscle actin (α-SMA) and Bcl2-associated agonist of cell death (Bad) proteins could be the molecular mechanism underlying AA-I-induced nephrotoxicity. On the other hand, AA-IVa did not regulate the activation of the p38-STAT3-S100A11 signaling pathway and had relatively little effect on the expression of α-SMA and Bad. Consequently, the difference in the regulation of p38-STAT3-S100A11 pathway, α-SMA, and Bad proteins between AA-I and AA-IVa may be responsible for the divergence in their level of nephrotoxicity. CONCLUSION: This is the first study to reveal the molecular mechanism underlying the difference in nephrotoxicity between AA-I and AA-IVa. Whether STAT3 is activated or not may be the key factor leading to the difference in nephrotoxicity between AA-I and AA-IVa.

Gypenosides suppress fibrosis of the renal NRK-49F cells by targeting miR-378a-5p through the PI3K/AKT signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: The incidence of renal fibrosis caused by chronic kidney disease is increasing year by year. Preventing the activation and conversion of kidney-intrinsic fibroblasts to a myofibroblast phenotype is an important target for blocking the development of renal interstitial fibrosis. Our team established a stable renal interstitial fibrosis cell model in the early stage, and the screening results showed that GPs has good anti-fibrosis potential. At this stage, only a few literatures have reported its anti-fibrosis effect, and the mechanism of action is still unclear. AIM OF THE STUDY: The massive synthesis and secretion of extracellular-matrix (ECM) components by activated fibroblasts in the kidneys causes irreversible renal interstitial fibrosis. Gypenosides (GPs) have been shown to decelerate this process, in which micro RNAs (miRNAs) play an important regulatory role. This study aimed to evaluate the mechanism underlying the suppressive effect of GPs on renal fibrosis. MATERIALS AND METHODS: This study used TGF-ß1-stimulated NRK-49F renal cells as an in-vitro model of renal interstitial fibrosis. First, the concentration range of GPs that significantly affects the cytoactive was determined. Then, the anti-fibrotic effects of various concentrations of GPs in the in-vitro model were assessed via immunofluorescence, western blotting, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Non-coding-RNA sequencing combined with bioinformatics was used to predict the mechanistic basis of the anti-fibrotic effect of GPs, and qRT-PCR was used to verify the sequencing results and bioinformatic predictions. The identified relationships of the anti-fibrotic effect of GPs with miR-378a-5p and the PI3K/AKT signaling were evaluated using a miR-NC mimic and the PI3K inhibitor LY294002 as controls, respectively. RESULTS: TGF-ß1 stimulation up-regulated α-SMA, COL1, and COL3 in NRK-49F cells, and this effect was suppressed by GPs. Additionally, TGF-ß1 stimulation significantly changed the expression levels of 151 miRNAs, and GPs significantly suppressed the effect of TGF-ß1 on the levels of 18 of these miRNAs. Among them, miR-3588 and miR-378a-5p were down-regulated, and miR-135b-5p and miR-3068-5p were up-regulated upon TGF-ß1 induction. Of these miRNAs, miR-378a-5p was predicted to target the mRNAs of numerous proteins mainly enriched in the PI3K/AKT signaling pathway. The miRNA transfection experiments with the miR-NC mimic and PI3K inhibitor as controls showed that miR-378a-5p overexpression could suppress the TGF-ß1-induced up-regulation of α-SMA, COL1, PI3K, and AKT, including the phosphorylated form (p-AKT). CONCLUSION: GPs inhibit the PI3K/AKT signaling by up-regulating miR-378a-5p in TGF-ß1-stimulated NRK-49F cells and thereby reduce their massive secretion of ECM components. Given that this in-vitro model of renal interstitial fibrosis closely mimics the in-vivo pathogenesis, our results most likely apply to the in-vivo conditions.

[Effect of electroacupuncture on transforming growth factor-ß1 and renal tubular epithelial mesenchymal transformation in renal tissue of spontaneously hypertensive rats].

OBJECTIVE: To observe the effects of electroacupuncture (EA) on renal fibrosis, the expression of transforming growth factor-ß1 (TGF-ß1) and epithelial mesenchymal transition (EMT) marker proteins in renal tissue of spontaneously hypertensive rats (SHR), so as to explore the underlying mechanism on EA alleviating hypertensive renal impairment. METHODS: Twenty-four male SHR were randomly divided into model group, losartan group and EA group, with 8 rats in each group, and eight male Wistar-Kyoto rats were taken as the normal group. Rats in the losartan group received gavage of losartan potassium solution (3 mg/mL, 30 mg·kg-1·d-1),once every other day for 12 weeks. Rats in the EA group received EA stimulation at bilateral "Shenshu" (BL23) and "Geshu" (BL17) (2 Hz/15 Hz, 1.0 mA), 15 min each time, once every other day for 12 weeks. The systolic blood pressure of caudal artery was measured before, and 4, 8 and 12 weeks after the intervention. The 24-hour urinary protein was measured before, and 6 and 12 weeks after the intervention. Histopathological changes of the left renal tissue were observed under light mircoscope after H.E. stain. Extracellular matrix (ECM) in renal tissues was observed after periodate Schiff staining. Basement membrane and collagen fibers were observed after Masson staining with collagen volume fraction (CVF) evaluated. The expression of TGF-ß1 mRNA in the right renal was detected by real-time fluorescence quantitative PCR. The expression of TGF-ß1 and EMT marker E-cadherin, α-SMA and fibronectin (FN) proteins in the left renal tissue was measured by immunohistochemistry. RESULTS: In the model group, irregular arrangement of nephrocytes, renal tubule atrophy, lumen stenosis, ECM hyperplasia and deposition, scar and sclerosis were observed, which were relatively milder in the EA and losartan groups. Compared with the normal group, tubulointerstitium CVF, systolic blood pressure of caudal artery before, and at 4, 8 and 12 weeks after the intervention, 24-hour urinary protein before, and at 6 and 12 weeks after the intervention, the expression of TGF-ß1 mRNA, area of TGF-ß1, α-SMA and FN positive staining in renal tissues were significantly increased (P<0.01), while the area of E-cadherin positive staining was significantly decreased (P<0.01) in the model group. Compared with the model group, tubulointerstitium CVF, systolic blood pressure of caudal artery at 4, 8 and 12 weeks after the intervention, 24-hour urinary protein at 6 and 12 weeks after the intervention, the expression of TGF-ß1 mRNA, area of TGF-ß1, α-SMA and FN positive staining in renal tissues were significantly decreased (P<0.01，P<0.05), while area of E-cadherin positive staining was significantly increased (P<0.01) in the losartan and EA groups. Compared with the losartan group, the area of E-cadherin was conside-rately increased (P<0.01), while the area of α-SMA protein decreased (P<0.01) in the EA group. CONCLUSION: EA could effectively alleviate hypertension and renal interstitial fibrosis in SHR, the mechanism of which may be related to its function in reducing the expression of TGF-ß1 and inhibiting EMT in renal tissue.

Shen Qi Wan attenuates renal interstitial fibrosis through upregulating AQP1 / 中国天然药物

Renal interstitial fibrosis (RIF) is the crucial pathway in chronic kidney disease (CKD) leading to the end-stage renal failure. However, the underlying mechanism of Shen Qi Wan (SQW) on RIF is not fully understood. In the current study, we investigated the role of Aquaporin 1 (AQP1) in SQW on tubular epithelial-to-mesenchymal transition (EMT). A RIF mouse model induced by adenine and a TGF-β1-stimulated HK-2 cell model were etablished to explore the involvement of AQP 1 in the protective effect of SQW on EMT in vitro and in vivo. Subsequently, the molecular mechanism of SQW on EMT was explored in HK-2 cells with AQP1 knockdown. The results indicated that SQW alleviated kidney injury and renal collagen deposition in the kidneys of mice induced by adenine, increased the protein expression of E-cadherin and AQP1 expression, and decreased the expression of vimentin and α-smooth muscle actin (α-SMA). Similarly, treatmement with SQW-containing serum significantly halted EMT process in TGF-β1 stimulated HK-2 cells. The expression of snail and slug was significantly upregulated in HK-2 cells after knockdown of AQP1. AQP1 knockdown also increased the mRNA expression of vimentin and α-SMA, and decreased the expression of E-cadherin. The protein expression of vimentin increased, while the expression of E-cadherin and CK-18 significantly decreased after AQP1 knockdown in HK-2 cells. These results revealed that AQP1 knockdown promoted EMT. Furthermore, AQP1 knockdown abolished the protective effect of SQW-containing serum on EMT in HK-2 cells. In sum, SQW attentuates EMT process in RIF through upregulation of the expression of AQP1.

Pharmacological functions of salidroside in renal diseases: facts and perspectives.

Rhodiola rosea is a valuable functional medicinal plant widely utilized in China and other Asian countries for its anti-fatigue, anti-aging, and altitude sickness prevention properties. Salidroside, a most active constituent derived from Rhodiola rosea, exhibits potent antioxidative, hypoxia-resistant, anti-inflammatory, anticancer, and anti-aging effects that have garnered significant attention. The appreciation of the pharmacological role of salidroside has burgeoned over the last decade, making it a beneficial option for the prevention and treatment of multiple diseases, including atherosclerosis, Alzheimer's disease, Parkinson's disease, cardiovascular disease, and more. With its anti-aging and renoprotective effects, in parallel with the inhibition of oxidative stress and inflammation, salidroside holds promise as a potential therapeutic agent for kidney damage. This article provides an overview of the microinflammatory state in kidney disease and discuss the current therapeutic strategies, with a particular focus on highlighting the recent advancements in utilizing salidroside for renal disease. The potential mechanisms of action of salidroside are primarily associated with the regulation of gene and protein expression in glomerular endothelial cells, podocytes, renal tubule cells, renal mesangial cells and renal cell carcinoma cell, including TNF-α, TGF-ß, IL-1ß, IL-17A, IL-6, MCP-1, Bcl-2, VEGF, ECM protein, caspase-3, HIF-1α, BIM, as well as the modulation of AMPK/SIRT1, Nrf2/HO-1, Sirt1/PGC-1α, ROS/Src/Cav-1, Akt/GSK-3ß, TXNIP-NLRP3, ERK1/2, TGF-ß1/Smad2/3, PI3K/Akt, Wnt1/Wnt3a ß-catenin, TLR4/NF-κB, MAPK, JAK2/STAT3, SIRT1/Nrf2 pathways. To the best of our knowledge, this review is the first to comprehensively cover the protective effects of salidroside on diverse renal diseases, and suggests that salidroside has great potential to be developed as a drug for the prevention and treatment of metabolic syndrome, cardiovascular and cerebrovascular diseases and renal complications.

Huangqi decoction attenuates renal interstitial fibrosis transforming growth factor-ß1/mitogen-activated protein kinase signaling pathways in 5/6 nephrectomy mice.

OBJECTIVE: To investigate the effect of Huangqi decoction on renal interstitial fibrosis and its association with the transforming growth factor-ß1 (TGF-ß1) / mitogen-activated protein kinase (MAPK) signaling pathway. METHODS: 120 C57/BL mice were randomly divided into six groups: sham group, Enalapril (20 mg/kg) group, 5/6 nephrectomy model group, and 5/6 nephrectomy model plus Huangqicoction (0.12, 0.36 and 1.08 g/kg respectively) groups. Detecting 24hours urinary protein, blood pressure, serum creatinine, urea nitrogen content changes. Periodic Acid-Schiff stain (PAS) and Masson's trichrome staining was used to observe the renal tissue pathological changes. Protein expression of TGF-ß1, Phosphorylated P38 mitogen activated protein kinases (P-P38), Phosphorylated c-jun N-terminal kinase (P-JNK), Phosphorylated extracellular regulated proteinhnase (P-ERK), Fibroblast-specific protein-1 (FSP-1), Alpha smooth muscle actin (α-SMA), Type III collagen (Collagen III), Connective tissue growth factor (CTGF), Bcl-2 Assaciated X protein (Bax) and B cell lymphoma 2 (Bcl-2) were measured with western blot and immunohistochemical. RESULTS: Both Huangqi decoction and Enalapril improved the kidney function, 24 h urinary protein and the fibrosis in 5/6 nephrectomy mice, Huangqi decoction downregulated the expressions of TGF-ß1, FSP-1, α-SMA, Collagen III and CTGF in a dose-dependent manner, and it has a significant difference ( 0.01) compared with model group.Huangqi decoction downregulated the expressions of P-P38, P-JNK, P-ERK and Bcl-2 in a dose-dependent manner, while upregulated the expression of Bax. CONCLUSIONS: The protective effect of Huangqi decoction for renal interstitial fibrosis in 5/6 nep-hrectomized mice the inhibition of Epithelial-Mesenchymal Transitions and downregulating the TGF-ß1/ MAPK signaling pathway.

Effects of salvianolic acid A and salvianolic acid B in renal interstitial fibrosis via PDGF-C/PDGFR-α signaling pathway.

BACKGROUND: Renal interstitial fibrosis (RIF) is the main pathological feature of end-stage renal disease (ESRD) caused by various chronic kidney diseases (CKD), and is closely related to renal dysfunction and patient prognosis. Salvianolic acid A (Sal A) and salvianolic acid B (Sal B), isolated from traditional Chinese medicine Salviae miltiorrhizae, have been confirmed to have anti-fibrotic effects on liver, cardiac and kidney. However, the precise molecular mechanism underlying the nephroprotective effects of Sal A and Sal B, and whether there is a difference between the two in RIF are still unclear. PURPOSE: This study investigated the pharmacological effects of Sal A and Sal B in RIF and explore the underlying mechanisms by in vivo and in vitro experiments. METHODS: The nephroprotective effects of Sal A, Sal B and Sal A+B were evaluated by assessing the parameters related to kidney function such as renal histology, renal function, urinary protein NAG, urinary ß2 microglobulin. In addition, RIF-related markers such as CTCF and Par3 were also detected. Thereafter, the related protein or gene levels of PDGF-C/PDGFR-α signaling pathways, apoptosis and endoplasmic reticulum stress (ERS) were determined by western blot, real-time PCR, flow cytometry or immunofluorescence staining. RESULTS: In vivo, the results showed that Sal A, Sal B and Sal A+B partially improved kidney dysfunction, increased the expression of Par-3 and reduced the expression of CTGF, PDGF-C and PDGFR-α. In vitro, the results also showed that Sal A, Sal B and Sal A+B reversed apoptosis and ERS in HSA-induced HK-2 cells via regulating PDGF-C/PDGFR-α signaling pathway. CONCLUSION: This article revealed a novel mechanism linking PDGF-C/PDGFR-α signaling pathway to RIF and suggested that Sal A, Sal B and Sal A+B were considered as potential therapeutic agents for the amelioration of RIF.

Shenkang injection protects against renal fibrosis by reducing perforin expression through the STING/TBK1/IRF3 signaling pathways in natural killer cells.

BACKGROUND: Immune activation, chronic inflammation, and renal interstitial fibrosis (RIF) are associated with chronic kidney disease (CKD). The herbal formula, Shenkang injection (SKI), has been reported to attenuate RIF. However, the mechanisms by which SKI alleviates renal fibrosis, especially the role of natural killer (NK) cells, are unknown and require exploration. PURPOSE: This study aimed to determine the mechanisms by which SKI alleviates RIF. METHODS: Differential gene expression between CKD mice and control groups was explored using bioinformatics analysis. To reveal how SKI reduces RIF in CKD, a CKD mouse model was established using folic acid for in vivo studies, and human kidney-2 cells were used for in vitro experiments. The effects of various SKI doses were then determined. Immunohistochemical staining, Enzyme-linked immunosorbent assay, western blotting, and quantitative real-time PCR were used for pathological and molecular expression detection. RESULTS: We first investigated the potential immune dysfunction in CKD using bioinformatics analysis. Some differentially expressed genes were enriched in immune-related functions. The expressions of perforin and interferon (IFN)-γ, which are mainly released by NK cells, were significantly higher in patients with CKD (p< 0.05). In vivo experiments showed that SKI alleviated renal fibrosis in a folic acid-induced renal fibrosis model. Serum creatinine and blood urea nitrogen levels were reduced in the high-dose SKI-treated group. Additionally, the mRNA and protein expression levels of type IV collagen and alpha-spinal muscular atrophy were reduced. Biochemical detection showed that SKI could also downregulate the activity of NK cells (by decreasing the expressions of perforin and IFN-γ). Increased levels of stimulator of interferon genes (STING)/TANK-binding kinase 1 (TBK1)/IFN regulatory factor 3 (IRF3), phosphorylation of TBK1, and IRF3 in FA-induced RIF mice were alleviated by SKI treatment, which was consistent with the results of in vitro experiments. CONCLUSION: These results demonstrated that SKI could decrease the activation of NK cells via the STING/TBK1/IRF3 signaling pathway, thereby alleviating RIF and protecting renal function in CKD. This may provide valuable evidence supporting the clinical use of SKI in the treatment of patients with CKD.

Research Progress of Chinese Herbal Medicine Intervention in Renal Interstitial Fibrosis.

Chronic kidney diseases usually cause renal interstitial fibrosis, the prevention, delay, and treatment of which is a global research hotspot. However, no definite treatment options are available in modern medicine. Chinese herbal medicine has a long history, rich varieties, and accurate treatment effects. Hitherto, many Chinese herbal medicine studies have emerged to improve renal interstitial fibrosis. This paper reviews the mechanisms of renal interstitial fibrosis and recent studies on the disease intervention with Chinese herbal medicine through literature search, intend to reveal the importance of Chinese herbal medicine in renal interstitial fibrosis. The results show that Chinese herbal medicine can improve renal interstitial fibrosis, and the effects of Chinese herbal medicine on specific pathological mechanisms underlying renal interstitial fibrosis have been explored. Additionally, the limitations and advantages of Chinese herbal medicine in the treatment of renal interstitial fibrosis, possible research directions, and new targets of Chinese herbal medicine are discussed to provide a basis for studies of renal interstitial fibrosis.

[Icariin improves renal interstitial fibrosis in a rat model of chronic renal failure by regulating mitochondrial dynamics].

This study aims to explore the effect of icariin(ICA) on mitochondrial dynamics in a rat model of chronic renal failure(CRF) and to investigate the molecular mechanism of ICA against renal interstitial fibrosis(RIF). CRF was induced in male Sprague-Dawley(SD) rats with 5/6(ablation and infarction, A/I) surgery(right kidney ablation and 2/3 infarction of the left kidney). Four weeks after surgery, the model rats were randomized into the following groups: 5/6(A/I) group, 5/6(A/I)+low-dose ICA group, and 5/6(A/I)+high-dose ICA group. Another 12 rats that received sham operation were randomly classified into 2 groups: sham group and sham+ICAH group. Eight weeks after treatment, the expression of collagen-Ⅰ(Col-Ⅰ), collagen-Ⅲ(Col-Ⅲ), mitochondrial dynamics-related proteins(p-Drp1 S616, p-Drp1 S637, Mfn1, Mfn2), and mitochondrial function-related proteins(TFAM, ATP6) in the remnant kidney tissues was detected by Western blot. The expression of α-smooth muscle actin(α-SMA) was examined by immunohistochemical(IHC) staining. The NRK-52 E cells, a rat proximal renal tubular epithelial cell line, were cultured in vitro and treated with ICA of different concentration. Cell viability was detected by CCK-8 assay. In NRK-52 E cells stimulated with 20 ng·mL~(-1) TGF-ß1 for 24 h, the effect of ICA on fibronectin(Fn), connective tissue growth factor(CTGF), p-Drp1 S616, p-Drp1 S637, Mfn1, Mfn2, TFAM, and ATP6 was detected by Western blot, and the ATP content and the mitochondrial morphology were determined. The 20 ng·mL~(-1) TGF-ß1-stimulated NRK-52 E cells were treated with or without 5 µmol·L~(-1) ICA+10 µmol·L~(-1) mitochondrial fusion promoter M1(MFP-M1) for 24 h and the expression of fibrosis markers Fn and CTGF was detected by Western blot. Western blot result showed that the levels of Col-Ⅰ, Col-Ⅲ, and p-Drp1 S616 were increased and the levels of p-Drp1 S637, Mfn1, Mfn2, TFAM, and ATP6 were decreased in 5/6(A/I) group compared with those in the sham group. The levels of Col-Ⅰ, Col-Ⅲ, and p-Drp1 S616 were significantly lower and the levels of p-Drp1 S637, Mfn1, Mfn2, TFAM, and ATP6 were significantly higher in ICA groups than that in 5/6(A/I) group. IHC staining demonstrated that for the expression of α-SMA in the renal interstitium was higher in the 5/6(A/I) group than in the sham group and that the expression in the ICA groups was significantly lower than that in the 5/6(A/I) group. Furthermore, the improvement in the fibrosis, mitochondrial dynamics, and mitochondrial function were particularly prominent in rats receiving the high dose of ICA. The in vitro experiment revealed that ICA dose-dependently inhibited the increase of Fn, CTGF, and p-Drp1 S616, increased p-Drp1 S637, Mfn1, Mfn2, TFAM, and ATP6, elevated ATP content, and improved mitochondrial morphology of NRK-52 E cells stimulated by TGF-ß1. ICA combined with MFP-M1 further down-regulated the expression of Fn and CTGF in NRK-52 E cells stimulated by TGF-ß1 compared with ICA alone. In conclusion, ICA attenuated RIF of CRF by improving mitochondrial dynamics.

Chinese herbal decoction astragalus and angelica exerts its therapeutic effect on renal interstitial fibrosis through the inhibition of MAPK, PI3K-Akt and TNF signaling pathways.

Astragalus and Angelica decoction (A&A) has been clinically used as a classical traditional Chinese medicine (TCM) formula in China for many years for the treatment of kidney diseases, especially renal interstitial fibrosis (RIF). However, the mechanisms underlying the therapeutic effects of A&A on RIF remains poorly understood. In the present study, systematic network pharmacology and effective experimental verification were utilized for the first time to elucidate the pharmacological efficacy and potential mechanism. The outcomes indicated that 22 active components and 87 target genes of A&A were identified and cross-referenced with RIF-associated genes, contributing to confirmation of 74 target genes of A&A for RIF. Pathway and functional enrichment analyses revealed that A&A had substantial effects on MAPK, PI3K-Akt and TNF signaling pathways. In addition, seven core targets with relatively higher betweenness and degree were identified in the constructed Chinese medicine material-chemical component-target-signal pathway network. Moreover, we verified the potential therapeutic effect of A&A in vivo (using a mouse model of RIF), confirming that A&A could effectively protect the kidney by regulating these target genes. The therapeutic effect of A&A on RIF could be attributed to its role in regulating the cell cycle, limiting the apoptosis, and inhibiting the inflammation.

Role of Autophagy in Renal Interstitial Fibrosis and Intervention of Chinese Medicine： A Review / 中国实验方剂学杂志

Renal interstitial fibrosis（RIF）is a common pathway for the progression of chronic kidney disease to renal failure，and its pathogenesis is mainly related to renal inflammatory damage，oxidative stress，apoptosis，and excessive extracellular matrix（ECM） deposition. Transforming growth factor-β1（TGF-β1） signaling pathway，mammalian target of rapamycin（mTOR） signaling pathway and other signaling pathways mediate the occurrence and development of RIF. Because of the complicated mechanism of RIF，there have been no specific prevention and treatment measures in clinical practice. Autophagy is a non-damaging response produced by eukaryotic cells. It maintains the balance of tissue homeostasis through degradation and reabsorption. At present， Chinese medicine has achieved desirable clinical effects with its unique advantages of multiple components，multiple effects，and multiple targets in the treatment of chronic kidney disease to delay the process of RIF. Scholars have found that autophagy is consistent with the Yin-Yang theory and the theory of abdominal mass in traditional Chinese medicine （TCM） to a certain extent，and it is involved in many aspects of RIF. The progression of RIF is closely related to autophagy. The targeted therapy of RIF by intervention in autophagy has become the frontier of research. However，little is known about the role of autophagy in RIF and the regulation of autophagy by Chinese medicine in the treatment of RIF. Therefore，it is necessary to further elucidate the relationship between autophagy and RIF in order to clarify the mechanism of autophagy in RIF and the mechanism of Chinese medicine regulating autophagy in targeted therapy of RIF. This article focused on the correlation between autophagy and RIF based on TCM theory，and systematically summarized the role of autophagy in RIF and the intervention of Chinese medicine by combining the effects of autophagy on inflammation damage，oxidative stress，apoptosis，and excessive ECM deposition in RIF， and the regulation mechanism of autophagy in TGF-β1 and mTOR signaling pathways in RIF. This study was expected to provide a certain reference for the clinical treatment of RIF and the development of new drugs.

Role of Autophagy in Renal Interstitial Fibrosis and Intervention of Chinese Medicine： A Review / 中国实验方剂学杂志

Renal interstitial fibrosis（RIF）is a common pathway for the progression of chronic kidney disease to renal failure，and its pathogenesis is mainly related to renal inflammatory damage，oxidative stress，apoptosis，and excessive extracellular matrix（ECM） deposition. Transforming growth factor-β1（TGF-β1） signaling pathway，mammalian target of rapamycin（mTOR） signaling pathway and other signaling pathways mediate the occurrence and development of RIF. Because of the complicated mechanism of RIF，there have been no specific prevention and treatment measures in clinical practice. Autophagy is a non-damaging response produced by eukaryotic cells. It maintains the balance of tissue homeostasis through degradation and reabsorption. At present， Chinese medicine has achieved desirable clinical effects with its unique advantages of multiple components，multiple effects，and multiple targets in the treatment of chronic kidney disease to delay the process of RIF. Scholars have found that autophagy is consistent with the Yin-Yang theory and the theory of abdominal mass in traditional Chinese medicine （TCM） to a certain extent，and it is involved in many aspects of RIF. The progression of RIF is closely related to autophagy. The targeted therapy of RIF by intervention in autophagy has become the frontier of research. However，little is known about the role of autophagy in RIF and the regulation of autophagy by Chinese medicine in the treatment of RIF. Therefore，it is necessary to further elucidate the relationship between autophagy and RIF in order to clarify the mechanism of autophagy in RIF and the mechanism of Chinese medicine regulating autophagy in targeted therapy of RIF. This article focused on the correlation between autophagy and RIF based on TCM theory，and systematically summarized the role of autophagy in RIF and the intervention of Chinese medicine by combining the effects of autophagy on inflammation damage，oxidative stress，apoptosis，and excessive ECM deposition in RIF， and the regulation mechanism of autophagy in TGF-β1 and mTOR signaling pathways in RIF. This study was expected to provide a certain reference for the clinical treatment of RIF and the development of new drugs.

Regulation of Wnt/β-catenin Signaling Pathway in Renal Interstitial Fibrosis by Traditional Chinese Medicine：A Review / 中国实验方剂学杂志

Chronic kidney disease （CKD） has become a public health problem worldwide with renal interstitial fibrosis （RIF） serving as the important pathological feature and pathological outcome of various CKD. Therefore， anti-fibrosis therapy has important practical significance for delaying the progression of CKD and improving the prognosis of CKD patients. The Wnt/β-catenin signaling pathway is a conserved signaling pathway through evolution， which plays a vital role in organ formation， tissue homeostasis， and disease progression during embryonic development. A growing body of research has confirmed that the Wnt/β-catenin signaling pathway is one of the key signaling pathways in a variety of kidney diseases and its activation is closely related to RIF. RIF is aggravated by the specific regulation of the expression of downstream target genes， such as fibroblasts， zinc finger transcription factor 1 （Snail1）， M2 macrophages， matrix metalloproteinase-7 （MMP-7）， plasminogen activator inhibitor-1 （PAI-1）， and renin-angiotensin system（RAS）， and relieved by targeting the signaling pathways， such as Klotho， Dickkopf-related protein 1 （DKK1）， secreted frizzled-related protein 1 （Sfrp1）， and indocyanine green-001. In addition，the pathological view of RIF in traditional Chinese medicine （TCM） coincides with that in western medicine. Based on the etiology and pathogenesis of TCM in the combination of deficiency and excess， TCM regulates fibrosis-promoting mediators by tonifying deficiency， eliminating turbidity， removing the toxin， resolving stasis， and treating both symptoms and root causes in a multi-target， multi-layer， and multi-pathway manner to inhibit the Wnt/β-catenin signaling pathway and play an important role in renal protection. Therefore， this study reviewed the regulatory mechanism of the Wnt/β-catenin signaling pathway in RIF and the protective effect of targeting this signaling pathway on renal function and discussed the potential role of TCM in delaying the progression of RIF， which is expected to provide new targets and strategies for the prevention and treatment of RIF.