Polydatin Ameliorates High Fructose-Induced Podocyte Oxidative Stress via Suppressing HIF-1α/NOX4 Pathway

Integrated network pharmacological analysis and multi-omics techniques to reveal the mechanism of polydatin in the treatment of silicosis via gut-lung axis

Silicosis is a pulmonary disease characterized by inflammation and progressive fibrosis. Previous studies have shown that polydatin (PD) has potential biological activity in key signaling pathways regulating inflammation and apoptosis. To investigate the effect of PD on rats with silicosis, this study used network pharmacology and molecular docking methods to determine the target of PD treatment for silicosis. The therapeutic effect of PD on silicosis was confirmed by measuring the lung injury score, hydroxyproline content, and mRNA expression levels of key targets. In addition, metagenomic sequencing and gas chromatography-mass spectrometry were used to determine the gut microbiota composition and targeted metabolomics analysis, respectively. The results showed that PD could inhibit the expression of inflammation-related indexes and apoptosis-related indexes at protein and mRNA levels. PD also regulates the diversity of the intestinal flora and the content of short-chain fatty acids. In conclusion, the current data suggest that PD has a protective effect against silica-induced lung injury and plays a protective role in regulating intestinal flora diversity and short-chain fatty acid levels through the gut-lung axis.

Polydatin, a derivative of resveratrol, ameliorates busulfan-induced oligozoospermia in mice by inhibiting NF-κB pathway activation and suppressing ferroptosis

Polydatin (PD), a glucoside derivative of resveratrol (RES), is extracted as a monomer compound from the dried rhizome of Polygonum cuspidatum. Our laboratory synthesized PD via the biotransformation of resveratrol. To assess the reproductive protective effects of PD, an oligozoospermia mouse model was induced by administering 30 mg/kg busulfan (BUS) via intraperitoneal injection. Initially, mice were categorized into groups based on PD concentrations of 10, 50, and 100 mg/kg. Subsequently, the optimal concentration of 10 mg/kg was ascertained based on testis weight and spermatological parameters. Additionally, a 10 mg/kg resveratrol group was included as a control. The findings revealed that exposure to BUS resulted in a reduction of testicular weight, diminished spermatogenic cells and epididymal sperm counts, increased sperm deformity, disordered testicular cytoskeleton, compromised blood-testis barrier integrity, and a significant decrease in serum sex hormone levels, notably testosterone. This resulted in decreased expression of androgen receptors and other testosterone-related proteins, increased levels of malondialdehyde and reactive oxygen species, and promoted testicular ferroptosis. However, PD could successfully reverse these injuries. High-throughput sequencing data demonstrated that polydatin significantly downregulated the expression of inflammatory and metabolic genes, including PRKCQ and CARD11. These proteins are pivotal in the activation of the NF-κB pathway during the inflammatory response. Molecular docking studies showed that PD could interact with PRKCQ and CARD11 to reduce the level of inflammation. Additionally, PD was shown to interact with the ferroptosis-promoting gene ACSL4, modulating ferroptosis. In summary, PD facilitates the reversal of BUS-induced oligozoospermia through the mitigation of oxidative stress and inflammation, the inhibition of ferroptosis, and the modulation of hormonal levels.

The trans-differentiation promotion of parietal epithelial cells by magnesium isoglycyrrhizinate to improve podocyte injury induced by high fructose consumption

BACKGROUND

Podocytes have limited proliferative capacity, which leads to irreversible glomerular injury in diverse kidney diseases. Magnesium isoglycyrrhizinate (MgIG), a hepatoprotective agent in clinic, has been reported to improve glomerular podocyte injury. However, the underlying mechanism of MgIG in ameliorating podocyte injury remains unclear.

PURPOSE

Glomerular parietal epithelial cells (PECs) are recognized as podocyte progenitors and play a pivotal role in the recovery following glomerular injury. This work aims to investigate the protective mechanisms of MgIG in mitigating glomerular injury by promoting PEC trans-differentiation.

STUDY DESIGN

A rat model of progressive glomerular podocyte injury, and in vitro models using the primary podocytes and primary PECs, were established to further explore the pharmacological mechanism of MgIG.

METHODS

Four-week-old male Sprague-Dawley (SD) rats were fed a 10 % fructose solution for 3, 6, 9 and 12 weeks to induce glomerular injury. The effects of MgIG on the progressive changes in podocytes and PECs, and the correlation between PEC density and podocyte loss, were analyzed. The mechanism of MgIG in triggering PEC trans-differentiation was investigated, by examining adenosine secretion in injured podocytes, as well as the expression of cluster of differentiation 44 (CD44), nephrin, adenosine receptor A2B (ARA2B) and glucocorticoid receptor (GR) in PECs both in vivo and in vitro.

RESULTS

Rats fed a high fructose diet exhibited progressive changes in glomerular PECs, including increased cell density and a preference for trans-differentiation. A positive correlation was observed between PEC density and podocyte loss. Co-culture experiments demonstrated that extracellular adenosine accumulation from injured podocytes induced by high fructose exposure promoted PEC trans-differentiation via ARA2B. MgIG significantly improved podocyte injury and exhibited effects similar to dexamethasone on nephrin upregulation and CD44 inhibition. Moreover, the effect of MgIG on PEC ARA2B activation was more effective than that of dexamethasone. The co-expression of paired box 2 (PAX2)+-Nephrin+ in glomeruli indicated that MgIG induced PEC trans-differentiation and podocyte regeneration in model rats. Accordingly, podocyte loss and increased urine albumin-to-creatinine ratio (UACR) were also alleviated. Moreover, MgIG, which acts as a GR agonist to activate GR, reversed the upregulation of CD44 and decreased ARA2B induced by tumor necrosis factor-α (TNF-α) in primary PECs. The siRNA interference experiment manifested that MgIG exhibited a more pronounced enhancement of GR upregulation, in contrast to ARA2B activation, to promote PEC trans-differentiation.

CONCLUSION

This work reports for the first time that PECs respond to the accumulation of extracellular adenosine from injured podocytes via activating ARA2B and focuses on the role of adenosine and adenosine receptors in the trans-differentiation of PECs. Furthermore, this study provides the first evidence that MgIG may promote podocyte regeneration by enhancing PEC trans-differentiation through GR activation, providing a research basis for investigating the glucocorticoid-like activity of MgIG in ameliorating glomerular podocyte injury.

Network Pharmacology and Machine Learning Reveal Salidroside's Mechanisms in Idiopathic Pulmonary Fibrosis Treatment

Purpose

Idiopathic pulmonary fibrosis (IPF) is an irreversible respiratory disease. In this study, we evaluated the efficacy of salidroside (SAL), the main component of Rhodiola rosea, in treating IPF.

Methods

The pharmacological effects of SAL against epithelial-mesenchymal transition (EMT) and IPF were assessed through in vivo and in vitro experiments. Targets for SAL in treating IPF were identified from various databases and a PPI network was constructed. Functional analyses of target genes were performed using GO, KEGG, DO, and GSEA. Core target genes were identified using LASSO logistic regression and support vector machine (SVM) analysis, followed by molecular docking simulations. Predicted targets and pathways were validated through Western blotting, qRT-PCR, and IHC.

Results

Our results demonstrated that SAL ameliorated alveolar epithelial cells (AECs) EMT and mitigated bleomycin -induced pulmonary fibrosis. Through network pharmacology, we identified 74 targets for SAL in the treatment of IPF (PFDR<0.05) and analyzed their biological functions. Based on these findings, we further applied machine learning techniques to narrow down 9 core targets (PFDR<0.05). Integrating the results from molecular docking, KEGG, and GSEA analyses, we selected three key targets-IGF1, hypoxia-inducible factor 1-alpha (HIF-1α), and MAPK (PFDR<0.05)-for further investigation. Our study revealed that SAL inhibits the IGF1 signaling pathway, thereby improving AECs senescence and cell cycle arrest. By inhibiting the HIF-1α pathway, SAL alleviates endoplasmic reticulum stress and reduces intracellular ROS accumulation. Moreover, SAL suppresses the activation of the MAPK signaling pathway, leading to a decrease in inflammation markers in AECs and lung tissue.

Conclusion

Experimental results suggest that SAL effectively ameliorates BLM-induced EMT and IPF, likely through the inhibition of IGF1, HIF-1α, and MAPK signaling pathways. This study holds potential translational prospects and may provide new perspectives and insights for the use of traditional Chinese medicine in the treatment of IPF.

Magnolol Inhibits High Fructose-Induced Podocyte Inflammation via Downregulation of TKFC/Sp1/HDAC4/Notch1 Activation

BACKGROUND/OBJECTIVES

High fructose has been implicated as an important trigger of kidney inflammation in patients and experimental models. Magnolol, isolated from Magnolia officinalis, has an anti-inflammatory effect, but its protective role in podocytes remains underexplored. This study explored the protective effects and underlying mechanism of magnolol against high fructose-induced podocyte inflammation.

METHODS

The effects of magnolol on high fructose-induced podocyte inflammation were assessed in male Sprague Dawley rats administered 10% (w/v) fructose water for 12 weeks and heat-sensitive human podocyte cell lines (HPCs) exposed to 5 mM fructose. Podocyte foot processes were examined using transmission electron microscopy. The expression levels of nephrin, podocin, tumor necrosis factor-α (TNF-α), Notch1 intracellular domain (NICD1), triokinase/FMN cyclase (TKFC), specificity protein 1 (Sp1) and histone deacetylase 4 (HDAC4) were determined by Western blot, immunofluorescence and real-time quantitative polymerase chain reaction (qRT-PCR). The chromatin immunoprecipitation (ChIP) assay was performed to evaluate the interaction between Sp1 and the promoter region of HDAC4.

RESULTS

Magnolol mitigated the impairment of glomerular filtration function in high fructose-fed rats. Besides, it significantly alleviated the inflammatory responses in glomeruli and HPCs, evidenced by decreased protein levels of TNF-α and NICD1. Increased protein levels of TKFC, Sp1 and HDAC4 were observed in high fructose-stimulated HPCs and rat glomeruli. TMP195, an HDAC4 inhibitor, reduced TNF-α and NICD1 protein levels in high fructose-exposed HPCs. The increased Sp1 was shown to associate with the promoter region of HDAC4, promoting HDAC4 protein expression in high fructose-exposed HPCs. The knockdown of TKFC in HPCs by TKFC siRNA decreased Sp1, HDAC4 and NICD1 protein levels, alleviating podocyte inflammatory response. Furthermore, magnolol inhibited TKFC/Sp1/HDAC4/Notch1 activation in vivo and in vitro.

CONCLUSIONS

Magnolol attenuated high fructose-induced podocyte inflammation possibly through the suppression of TKFC/Sp1/HDAC4/Notch1 activation, providing new evidence for its potential role in podocyte protection.

Traditional herbs: mechanisms to combat cellular senescence

Cellular senescence plays a very important role in the ageing of organisms and age-related diseases that increase with age, a process that involves physiological, structural, biochemical and molecular changes in cells. In recent years, it has been found that the active ingredients of herbs and their natural products can prevent and control cellular senescence by affecting telomerase activity, oxidative stress response, autophagy, mitochondrial disorders, DNA damage, inflammatory response, metabolism, intestinal flora, and other factors. In this paper, we review the research information on the prevention and control of cellular senescence in Chinese herbal medicine through computer searches of PubMed, Web of Science, Science Direct and CNKI databases.

Podocyte injury of diabetic nephropathy: Novel mechanism discovery and therapeutic prospects

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus, posing significant challenges in terms of early prevention, clinical diagnosis, and treatment. Consequently, it has emerged as a major contributor to end-stage renal disease. The glomerular filtration barrier, composed of podocytes, endothelial cells, and the glomerular basement membrane, plays a vital role in maintaining renal function. Disruptions in podocyte function, including hypertrophy, shedding, reduced density, and apoptosis, can impair the integrity of the glomerular filtration barrier, resulting in elevated proteinuria, abnormal glomerular filtration rate, and increased creatinine levels. Hence, recent research has increasingly focused on the role of podocyte injury in DN, with a growing emphasis on exploring therapeutic interventions targeting podocyte injury. Studies have revealed that factors such as lipotoxicity, hemodynamic abnormalities, oxidative stress, mitochondrial dysfunction, and impaired autophagy can contribute to podocyte injury. This review aims to summarize the underlying mechanisms of podocyte injury in DN and provide an overview of the current research status regarding experimental drugs targeting podocyte injury in DN. The findings presented herein may offer potential therapeutic targets and strategies for the management of DN associated with podocyte injury.