Association of triglyceride glucose index with the risk of acute kidney injury in patients with coronary revascularization: a cohort study.

BACKGROUND: The triglyceride glucose (TyG) index is a novel and reliable alternative marker for insulin resistance. Previous studies have shown that TyG index is closely associated with cardiovascular outcomes in cardiovascular diseases and coronary revascularization. However, the relationship between TyG index and renal outcomes of coronary revascularization is unclear. The purpose of this study was to investigate the correlation between TyG index and the risk of acute kidney injury (AKI) in patients with coronary revascularization. METHODS: A retrospective cohort study was conducted to select eligible patients with coronary revascularization admitted to ICU in the medical information mart for intensive care IV (MIMIC-IV). According to the TyG index quartile, these patients were divided into four groups (Q1-Q4). The primary endpoint was the incidence of AKI, and secondary endpoints included 28-day mortality and the rate of renal replacement therapy (RRT) use in the AKI population. Multivariate Cox regression analysis and restricted cubic splines (RCS) were used to analyze TyG index association with AKI risk. Kaplan-Meier survival analysis was performed to assess the incidence of endpoints in the four groups. RESULTS: In this study, 790 patients who underwent coronary revascularization surgery were included, and the incidence of AKI was 30.13%. Kaplan-Meier analysis showed that patients with a high TyG index had a significantly increased incidence of AKI (Log-rank P = 0.0045). Multivariate Cox regression analysis showed that whether TyG index was a continuous variable (HR 1.42, 95% CI 1.06-1.92, P = 0.018) or a categorical variable (Q4: HR 1.89, 95% CI 1.12-3.17, P = 0.017), and there was an independent association between TyG index and AKI in patients with coronary revascularization. The RCS curve showed a linear relationship between higher TyG index and AKI in this particular population (P = 0.078). In addition, Kaplan-Meier analysis showed a significantly increased risk of RRT application in a subset of AKI patients based on quartiles of TyG index (P = 0.029). CONCLUSION: TyG index was significantly associated with increased risk of AKI and adverse renal outcomes in patients with coronary revascularization. This finding suggests that the TyG index may be useful in identifying people at high risk for AKI and poor renal outcomes in patients with coronary revascularization.

Blood urea nitrogen to serum albumin ratio is associated with all-cause mortality in patients with AKI: a cohort study.

Background: This study aims to investigate the relationship between blood urea nitrogen to serum albumin ratio (BAR) and all-cause mortality in patients with acute kidney injury (AKI) and evaluate the effect of BAR on the prognosis of AKI. Methods: Adult patients with AKI admitted to the ICU in the Medical Information Mart for Intensive Care IV (MIMIC-IV) were selected in a retrospective cohort study. BAR (mg/g) was calculated using initial blood urea nitrogen (mg/dl)/serum albumin (g/dl). According to the BAR, these patients were divided into quartiles (Q1-Q4). Kaplan-Meier analysis was used to compare the mortality of the above four groups. Multivariate Cox regression analysis was used to evaluate the association between BAR and 28-day mortality and 365-day mortality. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated, and the subgroup analysis was finally stratified by relevant covariates. Results: A total of 12,125 patients with AKI were included in this study. The 28-day and 365-day mortality rates were 23.89 and 39.07%, respectively. Kaplan-Meier analysis showed a significant increase in all-cause mortality in patients with high BAR (Log-rank p < 0.001). Multivariate Cox regression analysis showed that BAR was an independent risk factor for 28-day mortality (4.32 < BAR≤7.14: HR 1.12, 95% CI 0.97-1.30, p = 0.114; 7.14 < BAR≤13.03: HR 1.51, 95% CI 1.31-1.75, p < 0.001; BAR>13.03: HR 2.07, 95% CI 1.74-2.47, p < 0.001; Reference BAR≤4.32) and 365-day mortality (4.32 < BAR≤7.14: HR 1.22, 95% CI 1.09-1.36, p < 0.001; 7.14 < BAR≤13.03: HR 1.63, 95% CI 1.46-1.82, p < 0.001; BAR>13.03: HR 2.22, 95% CI 1.93-2.54, p < 0.001; Reference BAR ≤ 4.32) in patients with AKI. The AUC of BAR for predicting 28-day mortality and 365-day mortality was 0.649 and 0.662, respectively, which is better than that of blood urea nitrogen and sequential organ failure assessment. In addition, subgroup analysis showed a stable relationship between BAR and adverse outcomes in patients with AKI. Conclusion: BAR is significantly associated with increased all-cause mortality in patients with AKI. This finding suggests that BAR may help identify people with AKI at high risk of mortality.

Causal relationship between PCSK9 inhibitor and primary glomerular disease: a drug target Mendelian randomization study.

Background: Successive observational studies have highlighted low-density lipoprotein cholesterol (LDL-C) as a standalone risk factor for the progression of chronic kidney disease (CKD) to end-stage renal disease. Lowering LDL-C levels significantly reduces the incidence of atherosclerotic events in patients with progressive CKD. Recent research indicates that proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors not only effectively lower LDL-C levels in CKD patients but also exhibit therapeutic potential for autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and ulcerative colitis. However, the role of PCSK9 inhibitors (PCSK9i) in treating CKD beyond lowering LDL-C levels remains uncertain. Therefore, this study employs drug-targeted Mendelian randomization (MR) to investigate the causal impact of PCSK9i on primary glomerular diseases such as IgA nephropathy (IgAN), membranous nephropathy (MN), and nephrotic syndrome (NS). Methods: Single-nucleotide polymorphisms (SNPs) linked to LDL-C were sourced from the Global Lipids Genetics Consortium genome-wide association study (GWAS). Genes situated in proximity to 3-Hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), and PCSK9 served as proxies for therapeutic inhibition of these targets. The causal link between PCSK9i and the risk of primary glomerular disorders was discovered using drug-target MR studies. The HMGCR inhibitor, a drug target of statins, was utilized for comparative analysis with PCSK9i. Primary outcomes included the risk assessment for IgAN, MN, and NS, using the risk of coronary heart disease as a positive control. Results: The inhibition of PCSK9, as proxied genetically, was found to significantly reduce the risk of IgAN [odds ratio, OR (95% confidence interval, CI) = 0.05 (-1.82 to 1.93), p = 2.10 × 10-3]. Conversely, this inhibition was associated with an increased risk of NS [OR (95% CI) = 1.78 (1.34-2.22), p = 0.01]. Similarly, HMGCR inhibitors (HMGCRi) demonstrated a potential reduction in the risk of IgAN [OR (95%CI) = 0.0032 (-3.58 to 3.59), p = 1.60 × 10-3). Conclusions: PCSK9i markedly decreased the risk of IgAN, suggesting a potential mechanism beyond their primary effect on LDL-C. However, these inhibitors were also associated with an increased risk of NS. On the other hand, HMGCRi appears to serve as a protective factor against IgAN. Conversely, PCSK9i may pose a risk factor for NS, suggesting the necessity for cautious application and further research into their impacts on various glomerular diseases.

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.

Ameliorative effects of Modified Huangqi Chifeng decoction on podocyte injury via autophagy mediated by PI3K/AKT/mTOR and AMPK/mTOR pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Proteinuria is recognized as a risk factor for the exacerbation of chronic kidney disease. Modified Huangqi Chifeng decoction (MHCD) has distinct advantages in reducing proteinuria. Our previous experimental results have shown that MHCD can inhibit excessive autophagy. However, the specific mechanism by which MHCD regulates autophagy needs to be further explored. AIM OF THE STUDY: In this study, in vivo and in vitro experiments were conducted to further clarify the protective mechanism of MHCD on the kidney and podocytes by regulating autophagy based on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) and adenosine monophosphate-activated protein kinase (AMPK)/mTOR signaling pathways. MATERIALS AND METHODS: By a single injection via the tail vein, Sprague-Dawley rats received Adriamycin (5 mg/kg) to establish a model of proteinuria nephropathy. They were divided into control, model, MHCD, 3-methyladenine (3 MA), 3 MA + MHCD, and telmisartan groups and were administered continuously for 6 weeks. The MHCD-containing serum was prepared, and a model of podocyte injury induced by Adriamycin (0.2 µg/mL) was established. RESULTS: MHCD reduced the 24-h urine protein levels and relieved pathological kidney damage. During autophagy in the kidneys of rats with Adriamycin-induced nephropathy, the PI3K/AKT/mTOR signaling pathway is inhibited, while the AMPK/mTOR signaling pathway is activated. MHCD antagonized these effects, thereby inhibiting excessive autophagy. MHCD alleviated Adriamycin-induced podocyte autophagy, as demonstrated using Pik3r1 siRNA and an overexpression plasmid for Prkaa1/Prkaa2. Furthermore, MHCD could activate the PI3K/AKT/mTOR signaling pathway while suppressing the AMPK/mTOR signaling pathway. CONCLUSIONS: This study demonstrated that MHCD can activate the interaction between the PI3K/AKT/mTOR and the AMPK/mTOR signaling pathways to maintain autophagy balance, inhibit excessive autophagy, and play a role in protecting the kidneys and podocytes.

Ferroptosis is involved in focal segmental glomerulosclerosis in rats.

To explore whether ferroptosis is involved in focal segmental glomerulosclerosis (FSGS) and its mechanism. The FSGS rat model was constructed by single nephrectomy combined with fractional tail vein injection of doxorubicin. 24-hour urine protein, serum biochemistry, HE, PAS and Masson pathological staining were measured to assess renal injury. Glomerular and morphological changes of ferroptosis were observed by transmission electron microscopy. Iron content in renal tissue was assessed by Prussian blue staining and iron detection. GSH/GSSG kit was used to detect the content and proportion of reduced/oxidized glutathione. Lipid peroxidation related proteins including MDA expression was assessed by colorimetry. The iron metabolism biomarkers such as hepcidin, ferroportin and TFR, ferroptosis biomarkers such as GPX4, ACSL4, and ferritinophagy biomarkers such as LC3II/LC3I, NCOA4, and FTH1 were detected by Western blot. Significant urinary protein, hyperlipidemia, azotemia, increased serum creatinine and hypoproteinemia were observed in FSGS rats. Histology and electron microscopy showed segmental sclerosis of glomeruli, compensatory enlargement of some glomeruli, occlusion of capillary lumen, balloon adhesion, increased mesangial matrix, atrophy of some tubules, and renal interstitial fibrosis in renal tissue of FSGS rats. The morphology of glomerular foot processes disappeared; the foot processes were extensively fused and some foot processes detached. Mitochondria became smaller, membrane density increased, and mitochondrial cristae decreased or disappeared. In addition, iron deposition was observed in renal tissue of FSGS rats. Compared with the control group, the levels of GSH, GSH/GSSG, GPX4, and ferroportin were reduced and the expression of GSSG, MDA, ACSL4, hepcidin, and TFR was increased in the renal tissue of FSGS rats; meanwhile, the expression of LC3II/LC3I and NCOA4 was increased and the expression of FTH1 was decreased. Ferroptosis is involved in the pathological progression of FSGS, which is probably associated with activation of ferritinophagy. This represents a potential therapeutic target for FSGS.

Inhibition of excessive autophagy alleviates renal injury and inflammation in a rat model of immunoglobulin A nephropathy.

The pathogenesis of immunoglobulin A nephropathy (IgAN) is closely related to immunity and inflammation. The clinical process of IgAN varies greatly, making the assessment of prognosis challenging and limiting progress on effective treatment measures. Autophagy is an important pathway for the development of IgAN. However, the role of autophagy in IgAN is complex, and the consequences of autophagy may change during disease progression. In the present study, we evaluated the dynamic changes in autophagy during IgAN. Specifically, we examined autophagy in the kidney of a rat model of IgAN at different time points. We found that autophagy was markedly and persistently induced in IgAN rats, and the expression level of inflammation was also persistently elevated. The autophagy enhancer rapamycin and autophagy inhibitor 3-methyladenine were used in this study, and the results showed that 3-methyladenine can alleviate renal injury and inflammation in IgAN rats. Our study provides further evidence for autophagy as a therapeutic target for IgAN.

Ferroptosis is involved in passive Heymann nephritis in rats.

Ferroptosis is found to be involved in some experimental models of kidney diseases, but its role in membrane nephropathy (MN) is still unclear. The purpose of this study is to explore whether ferroptosis occurred in MN, and the role of ferritinophagy. In this study, passive Heymann nephritis (PHN) rats were induced by single tail vein injection of anti-Fx1A serum, and normal rats were used as control. The changes of 24 h urinary protein, serum biochemical parameters, renal pathological damage, iron content, lipid peroxidation parameters, ferroptosis markers, and ferritinophagy markers were evaluated in the two groups. Compared with the control group, PHN rats showed obvious proteinuria, hypoproteinemia, and hyperlipidemia. Besides, more severe renal pathological damage and higher Fe2+ levels were observed in PHN rats, and the levels of malondialdehyde (MDA) increased significantly, while the levels of superoxide Dismutase (SOD) and glutathione (GSH) decreased. In addition, the expression of glutathione peroxidase 4 (GPX4) in renal tissues of PHN rats decreased significantly, while the expression of transferrin receptor (TFR) and acyl-CoA synthetase long-chain family member 4 (ACSL4) increased. The expression of microtubule associated protein 1 light chain 3 (LC3) II/LC3I and nuclear receptor coactivator 4 (NCOA4) increased significantly. Therefore, our study shows that ferroptosis is involved in the pathological damage of MN, and companied by activation of ferritinophagy.

Analysis of the alleviating effect of modified Huangqi Chifeng decoction on rats with focal segmental glomerulosclerosis based on gut microbiota and fecal metabolomics.

AIMS: To investigate the reno-protective effects of modified Huangqi Chifeng decoction (MHCD) on focal segmental glomerulosclerosis (FSGS) rats, and the underlying mechanisms of systemic regulation of gut microbiota and metabolite profiles. METHODS AND RESULTS: A rat FSGS model was established via unilateral nephrectomy plus doxorubicin injections. Rats were divided into sham, FSGS, and MHCD groups from which urine, blood, and histological tests were conducted. Fecal microbiotas were identified via 16S rRNA gene sequencing. Fecal metabolomics allowed for metabolic pathways analysis. Biochemical indices and pathological examination revealed that MHCD treatment improved the symptoms of FSGS, and corrected dysbiosis of gut microbiota, enriched the abundance of Bifidobacterium, Odoribacter, Christensella, Oscillospira, and reduced that of harmful bacteria such as Collinsella and Coprobacterilus at the genus level. Fecal metabolomic profiles revealed 152 different metabolites between the FSGS and sham groups, which are mainly enriched in signaling pathways like arachidonic acid, serotonergic synapse, and oxytocin. Besides, 93 differential metabolites between MHCD and FSGS groups were identified, which are mainly enriched in signaling pathways like steroid hormone biosynthesis, prostate cancer, and linoleic acid metabolism. Spearman's correlation analysis showed a correlation between differential fecal metabolites and enriched gut microbiota or serum biochemical parameters. CONCLUSIONS: MHCD may exert a reno-protective effect by regulating the gut microbiome and metabolite profiles in FSGS rats.

Effects and mechanisms of Chinese herbal medicine on IgA nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN), is the main cause of end-stage renal disease, that causes serious physical and psychological burden to patients worldwide. Some traditional treatment measures, such as blocking the renin-angiotensin-aldosterone system, controlling blood pressure, and following a low-protein diet, may not achieve satisfactory results. Therefore, more effective and safe therapies for IgAN are urgently needed. PURPOSE: The aim of this review is to summarize the clinical efficacy of Chinese herbal medicines (CHMs) and their active ingredients in the treatment and management of IgAN based on the results of clinical trials, systematic reviews, and meta-analyses, to fully understand the advantages and perspectives of CHMs in the treatment of IgAN. STUDY DESIGN AND METHODS: For this review, the following electronic databases were consulted: PubMed, ResearchGate, Science Direct, Web of Science, Chinese National Knowledge Infrastructure and Wanfang Data, "IgA nephropathy," "traditional Chinese medicine," "Chinese herbal medicine," "herb," "mechanism," "Meta-analysis," "systematic review," "RCT" and their combinations were the keywords to search the relevant literature. Data were collected from 1990 to 2022. RESULTS: This review found that the active ingredients of CHMs commonly act on multiple signaling pathways in the clinical treatment of IgAN, mainly with antioxidant, anti-inflammatory and anti-fibrosis effects, and regulation of autophagy. CONCLUSION: Compared with the single-target therapy of modern medicine, CHMs can regulate the corresponding pathways from the aspects of anti-inflammation, anti-oxidation, anti-fibrosis and autophagy to play a multi-target treatment of IgAN through syndrome differentiation and treatment, which has good clinical efficacy and can be used as the first choice or alternative therapy for IgAN treatment. This review provides evidence and research direction for a comprehensive clinical understanding of the protective effect of Chinese herbal medicine on IgAN.

Ferroptosis: A new mechanism of traditional Chinese medicine compounds for treating acute kidney injury.

Acute kidney injury (AKI) is a major health concern owing to its high morbidity and mortality rates, to which there are no drugs or treatment methods, except for renal replacement therapy. Therefore, identifying novel therapeutic targets and drugs for treating AKI is urgent. Ferroptosis is an iron-dependent and lipid-peroxidation-driven regulatory form of cell death and is closely associated with the occurrence and development of AKI. Traditional Chinese medicine (TCM) has unique advantages in treating AKI due to its natural origin and efficacy. In this review, we summarize the mechanisms underlying ferroptosis and its role in AKI, and TCM compounds that play essential roles in the prevention and treatment of AKI by inhibiting ferroptosis. This review suggests ferroptosis as a potential therapeutic target for AKI, and that TCM compounds show broad prospects in the treatment of AKI by targeting ferroptosis.

Clinical efficacy of supplementing qi dispelling wind and activating blood circulation method in the treatment of IgA nephropathy: A meta-analysis.

BACKGROUND: IgA nephropathy (IgAN) is a common primary glomerular disease, and supplementing qi dispelling wind and activating blood is commonly used as a treatment method in Chinese medicine. However, the existing studies have small sample sizes. This study aimed to use a meta-analysis to explore the clinical efficacy of this method and to systematically introduce this effective treatment. METHODS: We searched for randomized controlled trial studies on supplementing qi dispelling wind and activating blood circulation methods for IgAN indexed in the China National Knowledge Infrastructure, Wanfang Data, Chongqing VIP, SinoMed, PubMed, EMBASE, and Web of Science databases, which were interrogated from database inception to January 2022. Combining the inclusion and exclusion criteria to screen the literature, we included a total of 15 eligible studies; the quality of the included studies was evaluated using the risk of bias assessment tool of the Cochrane System Revies Manual 5.4. The outcome indexes were extracted, and a meta-analysis was performed using Review Manager 5.4 software. RESULTS: Fifteen articles were included in this review. A meta-analysis of the results led to the conclusion that supplementing qi dispelling wind and activating blood circulation prescription has beneficial effects on the total effective rate [odds ratios = 3.95, 95% confidence interval (CI) 2.76-5.67], and can reduce 24-hour urinary protein quantity (mean deviation = -0.35, 95% CI -0.54 to -0.16) and serum creatinine (mean deviation = -15.41,95% CI -28.39 to -2.44) without impact normal level of alanine transaminase, hemoglobin, and serum albumin. CONCLUSIONS: Supplementing qi dispelling wind and activating blood can significantly improve renal function and reduce 24-hour urinary protein quantity levels in patients with IgAN compared to the use of non-Chinese medicine treatment. This finding provides a rationale for using this method in the clinical treatment of IgAN.

Hirudin ameliorates diabetic nephropathy by inhibiting Gsdmd-mediated pyroptosis.

Our group previously reported that hirudin ameliorated diabetic nephropathy (DN) in streptozotocin (STZ)-injected rats, but the mechanism remained largely unknown. Therefore, we further explored its possible mechanism. We subcutaneously injected 5 U hirudin into STZ-induced WT mice or Gasdermin D (Gsdmd)-/- (KO) mice daily for 12 weeks, respectively, and evaluated their kidney injury. Next, glomerular endothelial cells (GECs), renal tubular epithelial cells (RTECs), and bone-marrow-derived macrophages (BMDMs) were isolated from WT mice and treated with hirudin in the presence of high glucose/lipopolysaccharides and ATP to measure the release of interleukin-18 and interleukin-1ß. Kidney injury induced by STZ injection was significantly ameliorated by hirudin through inhibiting Gsdmd-mediated pyroptosis in the mice, not Caspase 1-mediated apoptosis. Meanwhile, hirudin also suppressed pyroptosis in primary GECs, RTECs, and BMDMs in vitro. Moreover, the deletion of Gsdmd reduced pyroptosis and kidney injury both in vivo and in vitro. We also found that hirudin regulated the expression of Gsdmd by inhibiting interferon regulatory factor 2 (Irf2). Hirudin ameliorated Gsdmd-mediated pyroptosis by inhibiting irf2, leading to the improvement of kidney injury. Therefore, hirudin might serve as a potential therapeutic strategy to treat DN.

Traditional Chinese medicine compounds ameliorating glomerular diseases via autophagy: A mechanism review.

Glomerular diseases are major components of kidney disease, mainly manifested as podocyte disease, immune complex-associated glomerulonephritis, and renal autoimmune disease. They are the third leading cause of end-stage renal disease, especially in younger populations. Podocyte death or shedding is a key factor in the progression of glomerular diseases, and autophagy plays an important role in maintaining podocyte homeostasis. Dysfunction of autophagy has been associated with the progression of various glomerular diseases. Modulation of autophagy has been shown to play a protective role in experimental models of glomerular diseases, suggesting that autophagy is a potential therapeutic target for glomerular diseases. Traditional Chinese medicine (TCM) has unique advantages in the treatment of kidney disease. In vivo and in vitro studies have shown that TCM compounds can reduce podocyte apoptosis, inhibit inflammation, improve endoplasmic reticulum stress and oxidative stress responses, and play an active role via autophagy. This review summarizes the roles of autophagy in glomerular diseases and provides evidence that TCM compounds can regulate autophagy through different signaling pathways to ameliorate glomerular diseases.

Ameliorative role of SIRT1 in peritoneal fibrosis: an in vivo and in vitro study.

BACKGROUND: Peritoneal fibrosis is one of the major complications induced by peritoneal dialysis (PD). Damaged integrity and function of peritoneum caused by peritoneal fibrosis not only limits the curative efficacy of PD and but affects the prognosis of patients. However, the detailed mechanisms underlying the process remain unclear and therapeutic strategy targeting TGF-ß is deficient. Transforming growth factor-ß (TGF-ß) signaling participates in the progression of peritoneal fibrosis through enhancing mesothelial-mesenchymal transition of mesothelial cells. METHODS: The study aims to demonstrate the regulatory role of Sirtuin1 (SIRT1) to the TGF-ß signaling mediated peritoneal fibrosis. SIRT1-/- mice were used to establish animal model. Masson's staining and peritoneal equilibration assay were performed to evaluate the degree of peritoneal fibrosis. QRT-PCR assays were used to estimate the RNA levels of Sirt1 and matrix genes related to peritoneal fibrosis, and their protein levels were examined by Western blot assays. RESULTS: SIRT1 significantly decreased in vivo post PD treatment. SIRT1 knockout exacerbated peritoneal fibrosis both in vivo and vitro. Overexpression of SIRT1 efficiently inhibited peritoneal fibrosis by inhibiting the peritoneal inflammation and the activation of TGF-ß signaling. CONCLUSION: SIRT1 ameliorated peritoneal fibrosis both in vivo and in vitro through inhibiting the expression of protein matrix induced by TGF-ß signaling.

Ginkgo Biloba Extract EGB761 Ameliorates the Extracellular Matrix Accumulation and Mesenchymal Transformation of Renal Tubules in Diabetic Kidney Disease by Inhibiting Endoplasmic Reticulum Stress.

The study is aimed at investigating the effects of Ginkgo biloba extract EGB761 on renal tubular damage and endoplasmic reticulum stress (ERS) in diabetic kidney disease (DKD). A total of 50 C57BL/6 N mice were randomly divided into the normal group, DKD group, DKD+EGB761 group (36 mg/kg), and DKD+4-phenylbutyrate (4-PBA) group (1 g/kg). The DKD model was replicated by high-fat diet combined with intraperitoneal injection of streptozotocin (STZ). Renal tubular epithelial cells (HK-2) were divided into the control group, high-glucose group (30 mmol/L), EGB761 group (40 mg/L, 20 mg/L, 10 mg/L), TM group, and TM+4-PBA group. After 8 weeks of administration, expressions of serum creatinine (Scr), blood urea nitrogen (BUN), 24 h urinary protein (24 h Pro), fasting blood glucose (FBG), ß 2-microglobulin (ß 2-MG), and retinol binding protein 4 (RBP4) of mice were tested. The pathological changes of renal tissue were observed. The expressions of extracellular matrix (ECM) accumulation and epithelial-mesenchymal transition (EMT) markers α-smooth muscle actin (α-SMA), E-cadherin, fibronectin, and collagen IV, as well as the ERS markers GRP78 and ATF6, were tested by Western blot, qPCR, immunohistochemistry, or immunofluorescence. EGB761 could decrease the Scr, BUN, 24 h Pro, and FBG levels in the DKD group, alleviate renal pathological injury, decrease urine ß 2-MG, RBP4 levels, and decrease the expression of α-SMA, collagen IV, fibronectin, and GRP78, as well as ATF6, while increase the expression of E-cadherin. These findings demonstrate that EGB761 can improve renal function, reduce tubular injury, and ameliorate ECM accumulation and EMT in DKD kidney tubules, and the mechanism may be related to the inhibition of ERS.

Tongluo Digui decoction treats renal injury in diabetic rats by promoting autophagy of podocytes.

OBJECTIVE: To investigate the effects of Tongluo Digui decoction on renal injury and streptozotocin-induced podocyte autophagy in diabetic rats. METHODS: Male Sprague-Dawley rats were randomly divided into six groups: normal, model, Tongluo Digui decoction (high, medium, and low dose) and valsartan. Streptozotocin was injected intraperitoneally to replicate the diabetic animal model. After 8 weeks, proteinuria was evaluated to establish the diabetic nephropathy model. Treatments were administered daily via the intragastric route. At 16 weeks after gavage, we determined 24 h urine protein concentration, and blood glucose, serum creatinine, and urea nitrogen concentrations. Then, rats were sacrificed, and kidneys were harvested and stained with periodic acid-Schiff to evaluate the pathological changes in glomeruli, including glomerular podocytes by transmission electron microscopy. Western blot analysis was used to determine the expression of nephrin, podocin, p62, beclin-1, LC3Ⅱ/Ⅰ, and p-mTOR/mTOR protein in kidney tissues. RESULTS: Compared with the model group, Tongluo Digui decoction was associated with decreases in 24 h urine protein concentration, and blood glucose, hemoglobin A1c, serum creatinine, urea nitrogen concentrations, total serum protein and albumin. Concurrently, mesangial mesenteric broadening and fusion of foot processes were reduced, the glomerular basement membrane was not significantly thickened, and the number of podocytes and the number of autophagosomes in the podocytes was increased. Further, expression of nephrin, podocin, LC3Ⅱ, and beclin-1 protein in kidney tissue was up-regulated, while expression of p62 protein was down-regulated and mTOR phosphorylation was inhibited. CONCLUSION: Tongluo Digui decoction may inhibit the progression of diabetic nephropathy by inhibiting mTOR phosphorylation, thereby increasing autophagy to protect podocytes and reducing proteinuria.

Hirudin Protects Against Kidney Damage in Streptozotocin-Induced Diabetic Nephropathy Rats by Inhibiting Inflammation via P38 MAPK/NF-κB Pathway.

BACKGROUND: Inflammation-induced podocyte apoptosis plays an important role in kidney injury during diabetic nephropathy (DN). Hirudin (HIR), a natural compound extracted from leeches, can inhibit inflammation. However, whether HIR can protect the kidneys against inflammation during DN is unknown. In the present study, we aimed to study the effects of HIR on kidney damage in a DN rat model and explore its anti-inflammatory properties. METHODS: A streptozotocin-induced DN rat model was generated, and HIR was administered subcutaneously. Immortal podocytes and primary peritoneal macrophages were used for vitro studies. Hematoxylin and eosin staining was used to evaluate renal pathological changes; quantitative polymerase chain reaction and immunoblotting were used to detect gene expression; and TUNEL staining was used to detect apoptotic cells. RESULTS: Our results showed that HIR protected against renal injury, as indicated by kidney weight/body weight, serum creatinine, renal pathological changes, blood urea nitrogen, and detection of urine proteins. Notably, HIR treatment reduced macrophage infiltration, pro-inflammatory cytokine expression, and podocyte apoptosis in the kidney tissues of DN rats. In vitro, high glucose (HG) induced the activation of M1 macrophages, which was accompanied by increased podocyte apoptosis. HIR could decrease HG-induced podocyte apoptosis and suppress pro-inflammatory cytokine expression in podocytes in vitro. This was achieved via inhibition of p38 MAPK/NF-κB activation in renal tissues and podocytes. CONCLUSION: HIR could inhibit inflammation via the p38 MAPK/NF-κB pathway, prevent podocyte apoptosis, and protect against kidney damage in a DN rat model.

SIRT1-modified human umbilical cord mesenchymal stem cells ameliorate experimental peritoneal fibrosis by inhibiting the TGF-ß/Smad3 pathway.

INTRODUCTION: Peritoneal fibrosis is a serious complication of long-term peritoneal dialysis (PD). Combination therapies are emerging as a promising treatment for tissue damage. Here, we investigated the therapeutic potential of SIRT1-modified human umbilical cord mesenchymal stem cells (hUCMSCs) for peritoneal fibrosis. METHODS: SIRT1 was overexpressed in hUCMSCs to establish SIRT1-modified hUCMSCs. Co-culture and transplantation experiments were performed in TGF-ß-stimulated Met-5A cells and peritoneal damage rodent model to assess the therapeutic potential of SIRT1-modified hUCMSCs for peritoneal fibrosis through qPCR, Western blot, and peritoneal function analyses. RESULTS: SIRT1-modified hUCMSC administration had more potent anti-fibrosis ability than hUCMSCs, which significantly inhibited the expression of fibrotic genes and suppressed EMT process, increased ultrafiltration volume, and restored homeostasis of bioincompatible factors in dialysis solution. Mechanistically, SIRT1-modified hUCMSCs attenuated peritoneal fibrosis through reducing peritoneal inflammation and inhibiting the TGF-ß/Smad3 pathway in peritoneal omentum tissues. CONCLUSION: SIRT1-modified hUCMSCs might work as a promising therapeutic strategy for the treatment of peritoneal dialysis-induced peritoneal damage and fibrosis.

Hirudin Reduces the Expression of Markers of the Extracellular Matrix in Renal Tubular Epithelial Cells in a Rat Model of Diabetic Kidney Disease Through the Hypoxia-Inducible Factor-1α (HIF-1α)/Vascular Endothelial Growth Factor (VEGF) Signaling Pathway.

BACKGROUND This study aimed to investigate the effects of hirudin on the production of extracellular matrix (ECM) factors by renal tubular epithelial cells in a rat model of diabetic kidney disease (DKD) and HK-2 human renal tubule epithelial cells. MATERIAL AND METHODS Sprague-Dawley rats were divided into the normal control group (n=10), the normal control+hirudin group (n=10), the DKD model group (n=12) and the DKD+hirudin group (n=12). At the end of the study, renal histopathology was undertaken, and the expression of type IV collagen, fibronectin, hypoxia-inducible factor-1alpha (HIF-1alpha), and vascular endothelial growth factor (VEGF) were evaluated using immunohistochemistry, Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). HK-2 cells were cultured in glucose and treated with hirudin. Protein and mRNA expression of fibronectin, type IV collagen, HIF-1alpha, and VEGF were evaluated following knockdown or overexpression of HIF-1alpha. RESULTS Hirudin significantly improved renal function in the rat model of DKD (P<0.01), and significantly down-regulated the expression of fibronectin, type IV collagen, HIF-1alpha, and VEGF proteins (P<0.05). The expression of ECM associated proteins was increased in HK-2 cells treated with high glucose and reduced in the high glucose+shRNA HIF-1alpha group (P<0.05). Compared with the control group, the expression of ECM associated proteins was increased in the HIF-1alpha over-expressed group, and decreased following treatment with hirudin (P<0.05). CONCLUSIONS Hirudin reduced the expression of markers of ECM by inhibiting the HIF-1alpha/VEGF signaling pathway in DKD renal tubular epithelial cells.