Remdesivir alleviates skin fibrosis by suppressing TGF-ß1 signaling pathway.

Fibrotic skin diseases, such as keloids, are pathological results of aberrant tissue healing and are characterized by overgrowth of dermal fibroblasts. Remdesivir (RD), an antiviral drug, has been reported to have pharmacological activities in a wide range of fibrotic diseases. However, whether RD function on skin fibrosis remains unclear. Therefore, in our study, we explored the potential effect and mechanisms of RD on skin fibrosis both in vivo and in vitro. As expected, the results demonstrated that RD alleviated BLM-induced skin fibrosis and attenuates the gross weight of keloid tissues in vivo. Further studies suggested that RD suppressed fibroblast activation and autophagy both in vivo and in vitro. In addition, mechanistic research showed that RD attenuated fibroblasts activation by the TGF-ß1/Smad signaling pathway and inhibited fibroblasts autophagy by the PI3K/Akt/mTOR signaling pathway. In summary, our results demonstrate therapeutic potential of RD for skin fibrosis in the future.

Pirfenidone use in fibrotic diseases: What do we know so far?

BACKGROUND: Pirfenidone has demonstrated significant anti-inflammatory and antifibrotic effects in both animal models and some clinical trials. Its potential for antifibrotic activity positions it as a promising candidate for the treatment of various fibrotic diseases. Pirfenidone exerts several pleiotropic and anti-inflammatory effects through different molecular pathways, attenuating multiple inflammatory processes, including the secretion of pro-inflammatory cytokines, apoptosis, and fibroblast activation. OBJECTIVE: To present the current evidence of pirfenidone's effects on several fibrotic diseases, with a focus on its potential as a therapeutic option for managing chronic fibrotic conditions. FINDINGS: Pirfenidone has been extensively studied for idiopathic pulmonary fibrosis, showing a favorable impact and forming part of the current treatment regimen for this disease. Additionally, pirfenidone appears to have beneficial effects on similar fibrotic diseases such as interstitial lung disease, myocardial fibrosis, glomerulopathies, aberrant skin scarring, chronic liver disease, and other fibrotic disorders. CONCLUSION: Given the increasing incidence of chronic fibrotic conditions, pirfenidone emerges as a potential therapeutic option for these patients. However, further clinical trials are necessary to confirm its therapeutic efficacy in various fibrotic diseases. This review aims to highlight the current evidence of pirfenidone's effects in multiple fibrotic conditions.

[Modified Fangji Huangqi Decoction alleviates renal interstitial fibrosis by inhibiting TGF-ß1/Smad/Snail signaling pathway during epithelial-mesenchymal transition].

This study investigated the effects of modified Fangji Huangqi Decoction on the expression of proteins related to epithelial-mesenchymal transition(EMT) in a mouse model of unilateral ureteral obstruction( UUO) and in a rat renal tubular epithelial cell(NRK-52E) model of fibrosis induced by transforming growth factor ß1(TGF-ß1). It aims to decipher the molecular mechanism by which modified Fangji Huangqi Decoction alleviates renal interstitial fibrosis. C57/BL mice were subjected to UUO.After the surgery, the mice were treated with 0. 5-fold and 2-fold concentrations of modified Fangji Huangqi Decoction and fosinopril sodium(positive control) for 7 days. The interstitial collagen deposition in the kidney was assessed by Masson staining. Western blot and RT-qPCR were employed to determine the expression levels of TGF-ß1, phosphorylated Smad2/3(p-Smad2/3), Smad2/3, Snail,epithelial cadherin(E-cadherin), alpha smooth muscle actin(α-SMA), and vimentin. The NRK-52E cell model induced by TGF-ß1was treated with the serum samples collected from SD rats treated with different concentrations of modified Fangji Huangqi Decoction.The CCK-8 assay was employed to examine the effects of the serum samples on NRK-52E cell proliferation. The cell morphology in different groups was observed under a microscope. Furthermore, the modeled cells were treated with the serum containing 1-fold decoction. Western blot and RT-qPCR were then employed to measure the expression levels of p-Smad2/3, Smad2/3, Snail,E-cadherin, α-SMA, and vimentin in the cells. Under the same conditions, sh RNA was used to silence the Snail gene, and measurements were repeated before and after treatment with the serum containing 1-fold decoction. The results indicated that modified Fangji Huangqi Decoction alleviated the fibrotic injury in the mouse model of UUO and the fibrosis in the NRK-52E cell model. The treatment with the decoction down-regulated the protein and m RNA levels of EMT-related indicators including p-Smad2/3, α-SMA,Snail, and vimentin, while it up-regulated the expression of E-cadherin. After sh RNA silencing of the Snail gene, the protein and m RNA levels of E-cadherin, α-SMA, and vimentin showed no significant differences before and after treatment with the serum containing the decoction. The results suggest that modified Fangji Huangqi Decoction may alleviate renal interstitial fibrosis by inhibiting the TGF-ß1/Smad/Snail signaling pathway and regulating the EMT process.

α-Mangostin reduces hypertension in spontaneously hypertensive rats and inhibits EMT and fibrosis in Ang II-induced HK-2 cells.

Hypertension affects a large number of individuals globally and is a common cause of nephropathy, stroke, ischaemic heart disease and other vascular diseases. While many anti-hypertensive medications are used safely and effectively in clinic practice, controlling hypertensive complications solely by reducing blood pressure (BP) can be challenging. α-Mangostin, a xanthone molecule extracted from the pericarp of Garcinia mangostana L., has shown various beneficial effects such as anti-tumor, anti-hyperuricemia, and anti-inflammatory properties. However, the effects of α-Mangostin on hypertension remain unknown. In this study, we observed that α-Mangostin significantly decreased systolic and diastolic blood pressure in spontaneously hypertensive rats (SHR), possibly through the down-regulation of angiotensin II (Ang II). We also identified early markers of hypertensive nephropathy, including urinary N-acetyl-ß-D-glucosaminidase (NAG) and ß2-microglobulin (ß2-MG), which were reduced by α-Mangostin treatment. Mechanistic studies suggested that α-Mangostin may inhibit renal tubular epithelial-to-mesenchymal transformation (EMT) by down-regulating the TGF-ß signaling pathway, thus potentially offering a new therapeutic approach for hypertension and hypertensive nephropathy.

Icariin suppresses nephrotic syndrome by inhibiting pyroptosis and epithelial-to-mesenchymal transition.

CONTEXT: Nephrotic syndrome(NS) has emerged as a worldwide public health problem. Renal fibrosis is the most common pathological change from NS to end-stage renal failure, seriously affecting the prognosis of renal disease. Although tremendous efforts have been made to treat NS, specific drug therapies to delay the progression of NS toward end-stage renal failure are limited. Epimedium is generally used to treat kidney disease in traditional Chinese medicine. Icariin is a principal active component of Epimedium. METHODS: We used Sprague Dawley rats to establish NS models by injecting doxorubicin through the tail vein. Then icariin and prednisone were intragastric administration. Renal function was examined by an automatic biochemical analyzer. Pathology of the kidney was detected by Hematoxylin-Eosin and Masson staining respectively. Furthermore, RT-PCR, Enzyme-Linked Immunosorbent Assay, Immunohistochemistry, Western Blot and Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling staining were employed to detect the proteins related to pyroptosis and EMT. HK-2 cells exposed to doxorubicin were treated with icariin, and cell viability was assessed using the MTT. EMT was assessed using Enzyme-Linked Immunosorbent Assay and Western Blot. RESULTS: The study showed that icariin significantly improved renal function and renal fibrosis in rats. In addition, icariin effectively decreased NOD-like receptor thermal protein domain associated protein 3,Caspase-1, Gasdermin D, Ly6C, and interleukin (IL)-1ß. Notably, treatment with icariin also inhibited the levels of TGF-ß, α-SMA and E-cadherin. DISCUSSION AND CONCLUSIONS: It is confirmed that icariin can improve renal function and alleviate renal fibrosis by inhibiting pyroptosis and the mechanism may be related to epithelial-to-mesenchymal transition. Icariin treatment might be recommended as a new approach for NS.

Therapeutic application of nicotinamide: As a potential target for inhibiting fibrotic scar formation following spinal cord injury.

AIM: We aimed to confirm the inhibitory effect of nicotinamide on fibrotic scar formation following spinal cord injury in mice using functional metabolomics. METHODS: We proposed a novel functional metabolomics strategy to establish correlations between gene expression changes and metabolic phenotypes using integrated multi-omics analysis. Through the integration of quantitative metabolites analysis and assessments of differential gene expression, we identified nicotinamide as a functional metabolite capable of inhibiting fibrotic scar formation and confirmed the effect in vivo using a mouse model of spinal cord injury. Furthermore, to mimic fibrosis models in vitro, primary mouse embryonic fibroblasts and spinal cord fibroblasts were stimulated by TGFß, and the influence of nicotinamide on TGFß-induced fibrosis-associated genes and its underlying mechanism were examined. RESULTS: Administration of nicotinamide led to a reduction in fibrotic lesion area and promoted functional rehabilitation following spinal cord injury. Nicotinamide effectively downregulated the expression of fibrosis genes, including Col1α1, Vimentin, Col4α1, Col1α2, Fn1, and Acta2, by repressing the TGFß/SMADs pathway. CONCLUSION: Our functional metabolomics strategy identified nicotinamide as a metabolite with the potential to inhibit fibrotic scar formation following SCI by suppressing the TGFß/SMADs signaling. This finding provides new therapeutic strategies and new ideas for clinical treatment.

Costunolide Inhibits Chronic Kidney Disease Development by Attenuating IKKß/NF-κB Pathway.

Background: Chronic kidney disease (CKD) is a significant worldwide health concern that leads to high mortality rates. The bioactive substance costunolide (CTD) has demonstrated several pharmacological effects and holds promise as a CKD treatment. This study aims to investigate the impact of CTD on CKD and delve into its mechanisms of action. Methods: Unilateral ureteral obstruction (UUO) methods and renal fibrosis mice models were created. Various concentrations of CTD were injected into UUO mice models to investigate the therapeutic effects of CTD on renal fibrosis of mice. Then, renal morphology, pathological changes, and the expression of genes related to fibrosis, inflammation and ferroptosis were analysed. RNA sequencing was utilized to identify the main biological processes and pathways involved in renal injury. Finally, both overexpression and inhibition of IKKß were studied to examine their respective effects on fibrosis and inflammation in both in vitro and in vivo models. Results: CTD treatment was found to significantly alleviate fibrosis, inflammation and ferroptosis in UUO-induced renal fibrosis mice models. The results of RNA sequencing suggested that the IKKß acted as key regulatory factor in renal injury and the expression of IKKß was increased in vitro and in vivo renal fibrosis model. Functionally, down-regulated IKKß expression inhibits ferroptosis, inflammatory cytokine production and collagen deposition. Conversely, IKKß overexpression exacerbates progressive renal fibrosis. Mechanistically, CTD alleviated renal fibrosis and inflammation by inhibiting the expression of IKKß and attenuating IKKß/NF-κB pathway. Conclusion: This study demonstrates that CTD could mitigate renal fibrosis, ferroptosis and inflammation in CKD by modulating the IKKß/NF-κB pathway, which indicates targeting IKKß has an enormous potential for treating CKD.

Chlorogenic acid alleviates renal fibrosis by reducing lipid accumulation in diabetic kidney disease through suppressing the Notch1 and Stat3 signaling pathway.

AIMS: Abnormal renal lipid metabolism causes renal lipid deposition, which leads to the development of renal fibrosis in diabetic kidney disease (DKD). The aim of this study was to investigate the effect and mechanism of chlorogenic acid (CA) on reducing renal lipid accumulation and improving DKD renal fibrosis. METHODS: This study evaluated the effects of CA on renal fibrosis, lipid deposition and lipid metabolism by constructing in vitro and in vivo models of DKD, and detected the improvement of Notch1 and Stat3 signaling pathways. Molecular docking was used to predict the binding between CA and the extracellular domain NRR1 of Notch1 protein. RESULTS: In vitro studies have shown that CA decreased the expression of Fibronectin, α-smooth muscle actin (α-SMA), p-smad3/smad3, alleviated lipid deposition, promoted the expression of carnitine palmitoyl transferase 1 A (CPT1A), and inhibited the expression of cholesterol regulatory element binding protein 1c (SREBP1c). The expression of Notch1, Cleaved Notch1, Hes1, and p-stat3/stat3 were inhibited. These results suggested that CA might reduce intercellular lipid deposition in human kidney cells (HK2) by inhibiting Notch1 and stat3 signaling pathways, thereby improving fibrosis. Further, in vivo studies demonstrated that CA improved renal fibrosis and renal lipid deposition in DKD mice by inhibiting Notch1 and stat3 signaling pathways. Finally, molecular docking experiments showed that the binding energy of CA and NRR1 was -6.6 kcal/mol, which preliminarily predicted the possible action of CA on Notch1 extracellular domain NRR1. CONCLUSION: CA reduces renal lipid accumulation and improves DKD renal fibrosis by inhibiting Notch1 and stat3 signaling pathways.

Vasoactive and Antifibrotic Properties of Cannabinoids and Applications to Vasospastic/Vaso-Occlusive Disorders: A Systematic Review.

BACKGROUND: Management of vasospastic and vaso-occlusive disorders is a complex challenge, with current treatments showing varied success. Cannabinoids have demonstrated both vasodilatory and antifibrotic properties, which present potential mechanisms for therapeutic relief. No existing review examines these effects in peripheral circulation in relation to vasospastic and vaso-occlusive disorders. This study aims to investigate vasodilatory and antifibrotic properties of cannabinoids in peripheral vasculature for application in vasospastic and vaso-occlusive disorders affecting the hand. METHODS: A systematic search was conducted by 2 independent reviewers across PubMed, Cochrane, Ovid MEDLINE, and CINAHL to identify studies in accordance with the determined inclusion/exclusion criteria. Information regarding study design, medication, dosage, and hemodynamic or antifibrotic effects were extracted. Descriptive statistics were used to summarize study findings as appropriate. RESULTS: A total of 584 articles were identified, and 32 were selected for inclusion. Studies were grouped by effect type: hemodynamic (n = 17, 53%) and antifibrotic (n = 15, 47%). Vasodilatory effects including reduced perfusion pressure, increased functional capillary density, inhibition of vessel contraction, and increased blood flow were reported in 82% of studies. Antifibrotic effects including reduced dermal thickening, reduced collagen synthesis, and reduced fibroblast migration were reported in 100% of studies. CONCLUSION: Overall, cannabinoids were found to have vasodilatory and antifibrotic effects on peripheral circulation via both endothelium-dependent and independent mechanisms. Our review suggests the applicability of cannabis-based medicines for vasospastic and vaso-occlusive disorders affecting the hand (eg, Raynaud disease, Buerger disease). Future research should aim to assess the effectiveness of cannabis-based medicines for these conditions.

IBPA a mutual prodrug of ibuprofen and acetaminophen alleviates inflammation, immune dysregulation and fibrosis in preclinical models of systemic sclerosis.

Systemic sclerosis (SSc) is a devastating autoimmune illness with a wide range of clinical symptoms, including vascular abnormalities, inflammation, and persistent and progressive fibrosis. The disease's complicated pathophysiology makes it difficult to develop effective therapies, necessitating research into novel therapeutic options. Molecular hybridization is a strategy that can be used to develop new drugs that act on two or multiple targets and represents an interesting option to be explored for the treatment of complex diseases. We aimed to evaluate the effects of a hybrid mutual prodrug of ibuprofen and acetaminophen (IBPA) in peripheral blood mononuclear cells (PBMC) isolated from SSc patients, and in an in vivo model of SSc induced in BALB/c mice by intradermal injections of hypochlorous acid (HOCl) for 6 weeks. The mice were treated at the same time with daily intraperitoneal injections of IBPA (40 mg/kg). Pulmonary and skin fibrosis as well as immune responses were evaluated. IBPA significantly decreased the release of cytokines in PBMC culture supernatants from SSc patients after stimulation with phytohemagglutinin-M (IL-2, IL-4, IL-6, IL-10, IL-13, IL-17A, TNF and IFN-γ).In HOCl-induced SSc, IBPA treatment prevented dermal and pulmonary fibrosis, in addition to reducing CD4 + T and B cells activation and reversing the M2 polarization of macrophages in spleen cells, and inhibiting IFN-γ secretion in splenocyte cultures. These results show the anti-inflammatory and antifibrotic effects of IBPA in SSc and highlight the therapeutic potential of this mutual prodrug, providing support for future studies.

Unlocking the potential of tranilast: Targeting fibrotic signaling pathways for therapeutic benefit.

Fibrosis is the excessive deposition of extracellular matrix in an organ or tissue that results from an impaired tissue repair in response to tissue injury or chronic inflammation. The progressive nature of fibrotic diseases and limited treatment options represent significant healthcare challenges. Despite the substantial progress in understanding the mechanisms of fibrosis, a gap persists translating this knowledge into effective therapeutics. Here, we discuss the critical mediators involved in fibrosis and the role of tranilast as a potential antifibrotic drug to treat fibrotic conditions. Tranilast, an antiallergy drug, is a derivative of tryptophan and has been studied for its role in various fibrotic diseases. These include scleroderma, keloid and hypertrophic scars, liver fibrosis, renal fibrosis, cardiac fibrosis, pulmonary fibrosis, and uterine fibroids. Tranilast exerts antifibrotic effects by suppressing fibrotic pathways, including TGF-ß, and MPAK. Because it disrupts fibrotic pathways and has demonstrated beneficial effects against keloid and hypertrophic scars, tranilast could be used to treat other conditions characterized by fibrosis.

Celastrol alleviates subconjunctival fibrosis induced by silicone implants mimicking glaucoma surgery.

Subconjunctival fibrosis is critical to the outcomes of several ophthalmic conditions or procedures, such as glaucoma filtering surgery. This study aimed to investigate the anti-fibrotic effect of celastrol on subconjunctival fibrosis and to further reveal the underlying mechanisms. We used celastrol-loaded nanomicelles hydrogel hybrid as a sustained-release drug. A rabbit model of subconjunctival fibrosis following silicone implantation was used for in vivo study, and TGF-ß1-induced human pterygium fibroblast (HPF) activation as an in vitro model. The effects of celastrol on inhibiting TGF-ß1-induced migration and proliferation of HPFs were evaluated by scratch wound assay and CCK-8, respectively. Immunofluorescence and western blotting were used to examine the effect of celastrol on the expression of α-SMA, collagen I, fibronectin, and the targets of the Hippo signaling pathway. We found that in vivo celastrol treatment reduced the expression of YAP and TAZ in subconjunctival tissue. Moreover, celastrol alleviated collagen deposition and subconjunctival fibrosis at 8 weeks. No obvious tissue toxicity was observed in the rabbit models. Mechanistically, celastrol significantly inhibited TGF-ß1-induced proliferation and migration of HPFs. Pretreatment of HPFs with celastrol also suppressed the TGF-ß1-induced protein expression of α-SMA, collagen I, fibronectin, TGF-ßRII, phosphorylated Smad2/3, YAP, TAZ, and TEAD1. In conclusion, celastrol effectively prevented subconjunctival fibrosis through inhibiting TGF-ß1/Smad2/3-YAP/TAZ pathway. Celastrol could serve as a promising therapy for subconjunctival fibrosis.

Targeted delivery of type I TGF-ß receptor-mimicking peptide to fibrotic kidney for improving kidney fibrosis therapy via enhancing the inhibition of TGF-ß1/Smad and p38 MAPK pathways.

Renal fibrosis is a representative pathological feature of various chronic kidney diseases, and efficient treatment is needed. Interstitial myofibroblasts are a key driver of kidney fibrosis, which is dependent on the binding of TGF-ß1 to type I TGF-ß receptor (TßRI) and TGF-ß1-related signaling pathways. Therefore, attenuating TGF-ß1 activity by competing with TGF-ß1 in myofibroblasts is an ideal strategy for treating kidney fibrosis. Recently, a novel TßRI-mimicking peptide RIPΔ demonstrated a high affinity for TGF-ß1. Thus, it could be speculated that RIPΔ may be used for anti-fibrosis therapy. Platelet-derived growth factor ß receptor (PDGFßR) is highly expressed in fibrotic kidney. In this study, we found that target peptide Z-RIPΔ, which is RIPΔ modified with PDGFßR-specific affibody ZPDGFßR, was specifically and highly taken up by TGF-ß1-activated NIH3T3 fibroblasts. Moreover, Z-RIPΔ effectively inhibited the myofibroblast proliferation, migration and fibrosis response in vitro. In vivo and ex vivo experiments showed that Z-RIPΔ specifically targeted fibrotic kidney, improved the damaged renal function, and ameliorated kidney histopathology and renal fibrosis in UUO mice. Mechanistic studies showed that Z-RIPΔ hold the stronger inhibition of the TGF-ß1/Smad and TGF-ß1/p38 pathways than unmodified RIPΔ in vitro and in vivo. Furthermore, systemic administration of Z-RIPΔ to UUO mice led to minimal toxicity to major organs. Taken together, RIPΔ modified with ZPDGFßR increased its therapeutic efficacy and reduced its systemic toxicity, making it a potential candidate for targeted therapy for kidney fibrosis.

Oridonin ameliorates renal fibrosis in diabetic nephropathy by inhibiting the Wnt/ß-catenin signaling pathway.

Diabetic nephropathy (DN) is one of the most serious and frequent complications among diabetes patients and presently constitutes vast the cases of end-stage renal disease worldwide. Tubulointerstitial fibrosis is a crucial factor related to the occurrence and progression of DN. Oridonin (Ori) is a diterpenoid derived from rubescens that has diverse pharmacological properties. Our previous study showed that Ori can protect against DN by decreasing the inflammatory response. However, whether Ori can alleviate renal fibrosis in DN remains unknown. Here, we investigated the mechanism through which Ori affects the Wnt/ß-catenin signaling pathway in diabetic rats and human proximal tubular epithelial cells (HK-2) exposed to high glucose (HG) levels. Our results revealed that Ori treatment markedly decreased urinary protein excretion levels, improved renal function and alleviated renal fibrosis in diabetic rats. In vitro, HG treatment increased the migration of HK-2 cells while reducing their viability and proliferation rate, and treatment with Ori reversed these changes. Additionally, the knockdown of ß-catenin arrested cell migration and reduced the expression levels of Wnt/ß-catenin signaling-related molecules (Wnt4, p-GSK3ß and ß-catenin) and fibrosis-related molecules (α-smooth muscle actin, collagen I and fibronectin), and Ori treatment exerted an effect similar to that observed after the knockdown of ß-catenin. Furthermore, the combination of Ori treatment and ß-catenin downregulation exerted more pronounced biological effects than treatment alone. These findings may provide the first line of evidence showing that Ori alleviates fibrosis in DN by inhibiting the Wnt/ß-catenin signaling pathway and thereby reveal a novel therapeutic avenue for treating tubulointerstitial fibrosis.

Tanshinone IIA Liposomes Treat Doxorubicin-Induced Glomerulonephritis by Modulating the Microenvironment of Fibrotic Kidneys.

Renal fibrosis plays a key role in the pathogenesis of chronic kidney disease (CKD), in which the persistent high expression of transforming growth factor ß1 (TGF-ß1) and α-smooth muscle actin (α-SMA) contributes to the progression of CKD to renal failure. In order to improve the solubility, bioavailability, and targeting of tanshinone IIA (Tan IIA), a novel targeting material, aminoethyl anisamide-polyethylene glycol-1,2-distearoyl-sn-glycero-3-phosphate ethanolamine (AEAA-PEG-DSPE, APD) modified Tan IIA liposomes (APD-Tan IIA-L) was constructed. An animal model of glomerulonephritis induced by doxorubicin in BALB/c mice was established. APD-Tan IIA-L significantly decreased blood urea nitrogen and serum creatinine (SCr), and the consequences of renal tissue oxidative stress indicators showed that APD-Tan IIA-L downregulated malondialdehyde, upregulated superoxide dismutase, catalase, and glutathione peroxidase. Masson's trichrome staining showed that the deposition of collagen in the APD-Tan IIA-L group decreased significantly. The pro-fibrotic factors (fibronectin, collagen I, TGF-ß1, and α-SMA) and epithelial-mesenchymal transition marker (N-cadherin) were significantly inhibited by APD-Tan IIA-L. By improving the microenvironment of fibrotic kidneys, APD-Tan IIA-L attenuated TGF-ß1-induced excessive proliferation of fibroblasts and alleviated oxidative stress damage to the kidney, providing a new strategy for the clinical treatment of renal fibrosis.

Polydatin attenuates diabetic renal inflammatory fibrosis via the inhibition of STING pathway.

Diabetic nephropathy (DN) is a complication of diabetes and is mainly characterized by renal fibrosis, which could be attributed to chronic kidney inflammation. Stimulator of interferon genes (STING), a linker between immunity and metabolism, could ameliorate various metabolic and inflammatory diseases. However, the regulatory role of STING in DN remains largely unexplored. In this study, knockdown of STING decreased extracellular matrix (ECM), pro-inflammatory, and fibrotic factors in high glucose (HG)-induced glomerular mesangial cells (GMCs), whereas overexpression of STING triggered the inflammatory fibrosis process, suggesting that STING was a potential target for DN. Polydatin (PD) is a glucoside of resveratrol and has been reported to ameliorate DN by inhibiting inflammatory responses. Nevertheless, whether PD improved DN via STING remains unclear. Here, transcriptomic profiling implied that the STING/NF-κB pathway might be an important target for PD. We further found that PD decreased the protein expression of STING, and subsequently suppressed the activation of downstream targets including TBK1 phosphorylation and NF-κB nuclear translocation, and eventually inhibited the production of ECM, pro-inflammatory and fibrotic factors in HG-induced GMCs. Notably, results of molecular docking, molecular dynamic simulations, surface plasmon resonance, cellular thermal shift assay and Co-immunoprecipitation assay indicated that PD directly bound to STING and restored the declined proteasome-mediated degradation of STING induced by HG. In diabetic mice, PD also inhibited the STING pathway and improved the pathological changes of renal inflammatory fibrosis. Our study elucidated the regulatory role of STING in DN, and the novel mechanism of PD treating DN via inhibiting STING expression.

Advances in drug delivery-based therapeutic strategies for renal fibrosis treatment.

Renal fibrosis is the result of all chronic kidney diseases and is becoming a major global health hazard. Currently, traditional treatments for renal fibrosis are difficult to meet clinical needs due to shortcomings such as poor efficacy or highly toxic side effects. Therefore, therapeutic strategies that target the kidneys are needed to overcome these shortcomings. Drug delivery can be attained by improving drug stability and addressing controlled release and targeted delivery of drugs in the delivery category. By combining drug delivery technology with nanosystems, controlled drug release and biodistribution can be achieved, enhancing therapeutic efficacy and reducing toxic cross-wise effects. This review discusses nanomaterial drug delivery strategies reported in recent years. Firstly, the present review describes the mechanisms of renal fibrosis and anti-renal fibrosis drug delivery. Secondly, different nanomaterial drug delivery strategies for the treatment of renal injury and fibrosis are highlighted. Finally, the limitations of these strategies are also discussed. Investigating various anti-renal fibrosis drug delivery strategies reveals the characteristics and therapeutic effects of various novel nanosystem-derived drug delivery approaches. This will serve as a reference for future research on drug delivery strategies for renal fibrosis treatment.

Eplerenone reduces lymphangiogenesis in the contralateral kidneys of UUO rats.

Inflammation and fibrosis often occur in the kidney after acute injury, resulting in chronic kidney disease and consequent renal failure. Recent studies have indicated that lymphangiogenesis can drive renal inflammation and fibrosis in injured kidneys. However, whether and how this pathogenesis affects the contralateral kidney remain largely unknown. In our study, we uncovered a mechanism by which the contralateral kidney responded to injury. We found that the activation of mineralocorticoid receptors and the increase in vascular endothelial growth factor C in the contralateral kidney after unilateral ureteral obstruction could promote lymphangiogenesis. Furthermore, mineralocorticoid receptor activation in lymphatic endothelial cells resulted in the secretion of myofibroblast markers, thereby contributing to renal fibrosis. We observed that this process could be attenuated by administering the mineralocorticoid receptor blocker eplerenone, which, prevented the development of fibrotic injury in the contralateral kidneys of rats with unilateral ureteral obstruction. These findings offer valuable insights into the intricate mechanisms underlying kidney injury and may have implications for the development of therapeutic strategies to mitigate renal fibrosis in the context of kidney disease.

Renal protective effects and mechanisms of Astragalus membranaceus for diabetic kidney disease in animal models: An updated systematic review and meta-analysis.

BACKGROUND: Astragalus membranaceus (AM) shows potential therapeutic benefits for managing diabetic kidney disease (DKD), a leading cause of kidney failure with no cure. However, its comprehensive effects on renal outcomes and plausible mechanisms remain unclear. PURPOSE: This systematic review and meta-analysis aimed to synthesize the effects and mechanisms of AM on renal outcomes in DKD animal models. METHODS: Seven electronic databases were searched for animal studies until September 2023. Risk of bias was assessed based on SYRCLE's Risk of Bias tool. Standardized mean difference (SMD) or mean difference (MD) were estimated for the effects of AM on serum creatinine (SCr), blood urea nitrogen (BUN), albuminuria, histological changes, oxidative stress, inflammation, fibrosis and glucolipids. Effects were pooled using random-effects models. Heterogeneity was presented as I2. Subgroup analysis investigated treatment- and animal-related factors for renal outcomes. Publication bias was assessed using funnel plots and Egger's test. Sensitivity analysis was performed to assess the results' robustness. RevMan 5.3 and Stata MP 15 software were used for statistical analysis. RESULTS: Forty studies involving 1543 animals were identified for analysis. AM treatment significantly decreased SCr (MD = -19.12 µmol/l, 95 % CI: -25.02 to -13.23), BUN (MD = -6.72 mmol/l, 95 % CI: -9.32 to -4.12), urinary albumin excretion rate (SMD = -2.74, 95 % CI: -3.57, -1.90), histological changes (SMD = -2.25, 95 % CI: -3.19 to -1.32). AM treatment significantly improved anti-oxidative stress expression (SMD = 1.69, 95 % CI: 0.97 to 2.41), and decreased inflammation biomarkers (SMD = -3.58, 95 % CI: -5.21 to -1.95). AM treatment also decreased fibrosis markers (i.e. TGF-ß1, CTGF, collagen IV, Wnt4 and ß-catenin) and increased anti-fibrosis marker BMP-7. Blood glucose, lipids and kidney size were also improved compared with the DM control group. CONCLUSION: AM could improve renal outcomes and alleviate injury through multiple signaling pathways. This indicates AM may be an option to consider for the development of future DKD therapeutics.