Characterization of ferroptosis in kidney tubular cell death under diabetic conditions

Circ-0069561 as a novel diagnostic biomarker for progression of diabetic kidney disease

BACKGROUND

Circular RNAs (circRNAs) are non-coding RNAs that are key regulators of the initiation and progression of various human diseases. However, the role of circRNAs in diabetic kidney disease (DKD) remains unknown.

METHODS

Whole high-throughput RNA sequencing (RNA-seq) was performed on kidney tissues from clinical DKD patients and controls. Circ-0069561 with significantly up-regulated expression level was selected by real-time PCR (RT-PCR) analysis. RT-PCR and fluorescent in situ hybridization (FISH) further validated the expression and subcellular localization of circ-0069561 in type 2 diabetic mice and DKD patients. The clinical significance of circ-0069561 in DKD was evaluated. The circRNA-miRNA-ferroptosis associated mRNA network was constructed. The biological function of circ-0069561 in mouse podocyte clone 5 (MPC5) was analyzed.

RESULTS

The top 10 up-regulated circular RNAs were selected by RT-PCR validation, and the results demonstrated a significant elevation in the expression level of circ-0069561. The RT-PCR and FISH results demonstrated that the expression of circ-0069561 was elevated in renal tissues of type 2 diabetic mice and DKD patients, with a predominant localization in glomerulus. The ROC curves showed that circ-0069561 had a good diagnostic value in massive proteinuria (area under the curve = 0.889). Kaplan-Meier analysis showed that high expression of circ-0069561 was associated with an increased risk of primary endpoints. The circRNA-miRNA-mRNA network indicated that ferroptosis might be involved in the pathogenesis of DKD. In vitro experiments demonstrated that circ-0069561 aggravated glucose-induced podocyte damage and ferroptosis.

CONCLUSION

Circ-0069561 has the potential to be an ideal biomarker and therapeutic target for DKD progression.

Kidney lipid metabolism: impact on pediatric kidney diseases and modulation by early-life nutrition

Our review summarizes and evaluates the current state of knowledge on lipid metabolism in relation to the pathomechanisms of kidney disease with a focus on common pediatric kidney diseases. In addition, we discuss how nutrition in early childhood can alter kidney development and permanently shape kidney lipid and protein metabolism, which in turn affects kidney health and disease throughout life. Comprehensive integrated lipidomics and proteomics network analyses are becoming increasingly available and offer exciting new insights into metabolic signatures. Lipid accumulation, lipid peroxidation, oxidative stress, and dysregulated pro-inflammatory lipid mediator signaling have been identified as important mechanisms influencing the progression of minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, diabetic kidney disease, and acute kidney injury. We outline key features of metabolic homeostasis and lipid metabolic physiology in renal cells and discuss pathophysiological aspects in the pediatric context. On the one hand, special vulnerabilities such as reduced antioxidant capacity in neonates must be considered. On the other hand, there is a unique window of opportunity during kidney development, as nutrition in early life influences the composition of cellular phospholipid membranes in the growing kidney and thus affects local signaling pathways far beyond the growth phase.

Renal expression and clinical significance of Bach1-related oxidative stress indicators in patients with chronic glomerulonephritis

Chronic glomerulonephritis (CGN) and diabetic kidney disease are the primary causes of chronic kidney disease in China. Oxidative stress participates in both the glomerular damage and tubular injury of glomerular diseases. In this study, we evaluated the renal expression and clinical significance of Bach1-associated oxidative stress markers in IgA nephropathy (IgAN), membranous nephropathy (MN) and diabetic nephropathy (DN) using immunohistochemical staining. Our study demonstrated that there was significantly increased expression of Bach1 in the renal tubular injury of all the patients with chronic glomerulonephritis yet with faint expression in glomerular endothelial cells. However, the expression levels of SLC25A39 and Grx2 were significantly decreased in the renal tubular lesions. The renal expression levels of 4-HNE were significantly elevated in the renal tubular injury of all the patients. While the expression levels of MDA were significantly higher in the renal lesions of patients with IgAN and DN compared to the patients with MN. The semi-quantitative scores of renal Bach1 and 4-HNE expression were positively correlated with the renal injury indicators. Whereas the semi-quantitative scores of renal SLC25A39 and Grx2 expression demonstrated a negative correlation with the renal injury indicators. Bach1-associated oxidative stress indicators may be the promising pathologic biomarkers of oxidative stress injury in the tubular injury of patients with chronic glomerulonephritis, which proposed potential therapeutic target.

Nephroprotective effects of Amomum kravanh essential oil by inhibition of ferroptosis regulated by Nrf2/HO-1 signaling pathway

BACKGROUND

Amomum kravanh Pierre ex Gagnep. (BDK) is a Zingiberaceae plant traditionally widely used as a sweet fragrance, and commonly also utilized in minority medicine for various kidney diseases, especially chronic kidney disease (CKD) in Tibetan and Mongolian medicine. However, the underlying mechanisms by which it confers renal protection remain to be fully clarified.

PURPOSE

To investigate the renal protective mechanism of which BDK's essential oil exerts in rats with CKD induced by adenine and 5/6 nephrectomy.

METHODS

Rat models of adenine and 5/6 nephrectomy chronic nephropathy were established, and the therapeutic effects were evaluated by detecting the blood biochemical levels and H&E-/Masson staining and fiber-related factors. Then, the chemical composition of BDK's essential oil and blood components were analyzed using GC-MS. The efficacy of eucalyptol was evaluated by adenine and 5/6 nephrectomy CKD model, with mechanistic studies conducted using RNA-seq, western blot, and metabolomic approaches.

RESULTS

The blood biochemical levels and histopathological analyses (H&E-/Masson's staining) revealed that the BDK's essential oil significantly enhanced renal function and ameliorated kidney tissue fibrosis. Furthermore, GC-MS analysis identified 33 components in the essential oil of BDK, with eucalyptol being the predominant chemical component at 74.07 %. Eucalyptol is capable of entering the bloodstream in its prototypical form. Then, the efficacy and mechanism of eucalyptol were confirmed by adenine/5/6 nephrectomy CKD models, and based on RNA-seq analysis, we found that eucalyptol could significantly improve kidney function and fibrosis of kidney tissues by blocking TGF-β/smad and NF-κB pathways and inhibit ferroptosis through the Nrf2/HO-1 signaling pathway.

CONCLUSION

Both BDK's essential oil and its main constituent, eucalyptol, exhibited protective effects against CKD. They both ameliorated oxidative stress, inflammation, and fibrosis in adenine/5/6 nephrectomy rats. Eucalyptol is implicated in ferroptosis and regulation of renal fibrosis via the Nrf2/HO-1 pathway.

Mapping the future: bibliometric insights into ferroptosis and diabetic nephropathy

Background

Diabetic nephropathy (DN), a leading cause of end-stage renal disease, exerts a substantial burden on healthcare systems globally. Emerging evidence highlights ferroptosis - an iron-dependent form of cell death driven by lipid peroxidation and glutathione depletion - as a critical contributor to DN progression via oxidative stress, tubular injury, and glomerular dysfunction. Despite increasing research interest, a comprehensive synthesis of research trends and mechanistic insights is lacking.

Objective

This study integrated bibliometric analysis with a mechanistic review to map the evolving ferroptosis landscape in DN, identify research hotspots, and propose future directions for therapeutic development.

Methods

In total, 86 publications (2018-2023) were retrieved from the Web of Science Core Collection and analyzed using CiteSpace and VOSviewer. Co-occurrence networks, citation trends, and keyword bursts were examined to delineate global contributions, collaborative networks, and emerging themes.

Results

Annual publication numbers surged 12-fold after 2020, with China contributing the highest proportion (60.4%), and led by institutions such as Zhengzhou University. The United States of America and Germany showed high centrality in collaborative networks. Key research themes included glutathione peroxidase 4 (GPX4)-mediated antioxidant defenses, acyl-CoA synthetase long-chain family member 4 (ACSL4)-mediated lipid remodeling, and iron dysregulation. Frontiers in Endocrinology (nine articles) and Free Radical Biology and Medicine (highest citation count: 171) emerged as pivotal publication platforms. Mechanistic analyses identified three ferroptosis defense axes (GPX4, FSP1/CoQ10, and GCH1/BH4) and cell type-specific vulnerabilities in tubular, podocyte, and endothelial cells. Preclinical agents, including ginkgolide B (GB) and dapagliflozin, effectively restored iron homeostasis and attenuated oxidative damage.

Conclusion

Ferroptosis is a promising therapeutic target for DN, yet its clinical translation remains in its infancy. Future efforts should prioritize large-scale clinical trials, single-cell mechanistic profiling, and interdisciplinary integration to bridge molecular insights with precision therapies. This study provides a roadmap for advancing ferroptosis-targeted interventions for DN, emphasizing global collaborations and biomarker-driven strategies.

Tangshenning formula alleviates tubular injury in diabetic kidney disease via the Sestrin2/AMPK/PGC-1α axis: Restoration of mitochondrial function and inhibition of ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Tangshenning (TSN) is a traditional Chinese medicinal formula developed on principles of kidney tonification and collateral unblocking. TSN, formulated from Astragalus mongholicus Bunge, Rheum palmatum L., Ligusticum chuanxiong Hort., and Rosa laevigata Michx., has demonstrated significant clinical efficacy in the treatment of diabetic kidney disease (DKD). Our previous studies have suggested that TSN mitigates tubular injury in DKD by inhibiting ferroptosis, however, the precise molecular targets and mechanistic pathways underlying these effects remain to be fully elucidated.

AIM OF THE STUDY

We investigated whether the Sestrin2/AMPK/PGC-1α axis serves as a key pathway mediating TSN's protective effects against tubular injury in DKD.

METHODS

In vivo, a spontaneous DKD mouse model was developed using KK-Ay mice. In vitro, human tubular epithelial cells (TECs) were used to establish high glucose and ferroptosis models, as well as a Sestrin2 knockdown model for further analysis. Molecular docking was utilized to examine the binding interactions between TSN's key active components and Sestrin2. Colocalization of Sestrin2 and GPX4 was assessed using dual fluorescence staining. Protein expression levels related to the Sestrin2/AMPK/PGC-1α pathway, ferroptosis markers (SLC7A11 and GPX4), and the tubular injury marker KIM-1 were quantified via Western blot analysis. In vivo, DHE staining, TUNEL staining, and ferrous ion content measurement were performed to evaluate ferroptosis levels in renal tissue. In vitro, the BODIPY 581/591 C11 probe and ferrous ion assay were used to assess ferroptosis levels in TECs. MitoSOX staining, JC-1 assay, and ATP level measurements were conducted to evaluate mitochondrial function in TECs.

RESULTS

In vivo, our results demonstrated that TSN improved renal function, alleviated tubular injury, and reduced pathological damage in DKD mice. Furthermore, TSN upregulated the protein expression of the Sestrin2/AMPK/PGC-1α axis and decreased ferroptosis-related markers in the DKD mouse model. Similarly, in vitro, TSN enhanced the expression of the Sestrin2/AMPK/PGC-1α pathway, restored mitochondrial function, and inhibited ferroptosis in TECs under high glucose and ferroptosis-inducing conditions. Additionally, downregulation of Sestrin2 impaired the therapeutic effects of TSN.

CONCLUSION

TSN alleviates tubular injury in DKD by activating the Sestrin2/AMPK/PGC-1α pathway, restoring mitochondrial function, and inhibiting ferroptosis in TECs.

Ferroptosis in organ fibrosis: Mechanisms and therapeutic approaches

Ferroptosis, a form of iron-dependent regulated cell death, has emerged as a critical mechanism in the pathogenesis of organ fibrosis. This review aims to provide an overview of the molecular mechanisms underlying ferroptosis and its contribution to fibrosis in various organs, including the liver, lung, heart, and kidneys. We explore how dysregulated iron metabolism, lipid peroxidation, and oxidative stress contribute to ferroptosis and subsequent tissue damage, promoting the progression of fibrosis. In addition, we highlight the complex interplay between ferroptosis and other cellular processes such as apoptosis, necrosis, and inflammation in the fibrotic microenvironment. Furthermore, this review discusses current therapeutic strategies targeting ferroptosis, including iron chelation, antioxidants, and modulators of lipid peroxidation. We also examine ongoing clinical and preclinical studies aimed at translating these findings into viable treatments for fibrotic diseases. Understanding the role of ferroptosis in organ fibrosis offers novel therapeutic opportunities, with the potential to mitigate disease progression and improve patient outcomes.

Iron Metabolism and Ferroptosis in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a major diabetic microvascular complication that still lacks effective therapeutic drugs. Ferroptosis is a recently identified form of programmed cell death that is triggered by iron overload. It is characterized by unrestricted lipid peroxidation and subsequent membrane damage and is found in various diseases. Accumulating evidence has highlighted the crucial roles of iron overload and ferroptosis in DKD. Here, we review iron metabolism and the biology of ferroptosis. The role of aberrant ferroptosis in inducing diverse renal intrinsic cell death, oxidative stress, and renal fibrosis in DKD is summarized, and we elaborate on critical regulatory factors related to ferroptosis in DKD. Finally, we focused on the significance of ferroptosis in the treatment of DKD and highlight recent data regarding the novel activities of some drugs as ferroptosis inhibitors in DKD, aiming to provide new research targets and treatment strategies on DKD.

Engineered molybdenum disulfide nanosheets as scavengers against oxidative stress inhibit ferroptosis to alleviate acute kidney injury

Acute kidney injury (AKI) is a common clinical kidney dysfunction associated with high morbidity, elevated mortality, and poor prognosis. It results from redox imbalance caused by abnormal excess production of endogenous reactive oxygen species (ROS) at the renal tubules, which in turn initiates a series of pathological processes, such as cellular apoptosis, necrosis, and ferroptosis, eventually leading to structural and functional impairment of the kidney. Thereinto, ferroptosis induced by the lethal accumulation of lipid peroxidation is extensively involved in renal damage. Nanotechnology-mediated therapeutic strategies to scavenge excessive ROS and thereby inhibit ferroptosis represents a promising strategy for AKI management. Herein, we report two engineered ultrathin molybdenum disulfide (MoS2) nanosheets (NSs) modified with polyvinylpyrrolidone (PVP) and bovine serum albumin (BSA), respectively, with excellent biocompatibility and antioxidative defense capability for AKI treatment. The engineered NSs, with a readily variable valence state of molybdenum ions, rescued cell viability by consuming various forms of cellular ROS and significantly facilitated glutathione peroxidase 4 (GPX4) expression to mitigate ferroptosis in renal tubular epithelial cells. In a glycerol-induced AKI mouse model, the PVP-MoS2 NSs were largely accumulated in the injured kidneys, where they provided robust antioxidative protection against ROS attack and suppressed the oxidative stress-induced inflammatory response, thereby maintaining normal kidney function. Of the two engineered NSs, PVP-MoS2 displayed superior biological stability and therapeutic effects and could thus serve as a powerful antioxidant platform for use in the treatment of AKI and other ROS-associated diseases. This study underscores the potential of two-dimensional nanomaterials in precisely treating AKI and other ferroptosis-related diseases.

ACSL4 predicts rapid kidney function decline in patients with diabetic kidney disease

Background

Ferroptosis of kidney tubular epithelial cells contributes to the pathogenesis of diabetic kidney disease (DKD). An increase in the enzyme long-chain fatty acid CoA ligase 4 (ACSL4) favors ferroptosis. However, the association between ACSL4 in renal tubules and kidney outcomes of patients with DKD is unknown.

Methods

To investigate the predictive property of ACSL4 in rapid kidney function decline in patients with DKD, a retrospective cohort of 72 biopsy-proven DKD patients were enrolled and followed up for a median of 23 months. Tubular expression levels of ACSL4 in the renal biopsy specimens from 72 DKD patients and 12 control subjects were measured using immunohistochemistry staining. The associations between the ACSL4 level and clinical characteristics as well as rapid kidney function decline defined as an estimated glomerular filtration rate (eGFR) slope ≤ -5 ml/min/1.73m2/year were analyzed.

Results

ACSL4 was mainly expressed in tubular epithelial cells. The tubular ACSL4 expression levels in the DKD patients were significantly higher than those in the control subjects. ACSL4 was positively correlated with proteinuria and negatively correlated with albumin and hemoglobin at the time of the renal biopsy. During the follow-up time period, the median eGFR slope of these DKD patients was -2.30 ml/min/1.73m2/year. ACSL4 was negatively correlated with the eGFR slope. The top tertile of baseline ACSL4 was found to identify the subjects with DKD who were at high risk for rapid kidney function decline and a similar significant relationship was found using ACSL4 levels as a continuous variable.

Conclusions

ACSL4 was associated with a rapid progression of DKD and may serve as a novel pathological biomarker.

Xanthohumol attenuates TXNIP-mediated renal tubular injury in vitro and in vivo diabetic models

Thioredoxin-interacting protein (TXNIP), as a pivotal protein in the cellular stress response, plays a significant role in the progression of diabetic nephropathy (DN). Consequently, therapeutic strategies aimed at targeting TXNIP may offer novel interventions for patients with DN. Our study is to explore the therapeutic potential of targeting TXNIP in mitigating renal tubular injury induced by hyperglycemia. Cell viability and apoptosis of renal tubular epithelial cells (RTECs) were evaluated using CCK-8, Annexin V/7-AAD, and TUNEL staining after exposure to normal glucose (NG; 5 mM), high glucose (HG; 30 mM), or treatment with TXNIP inhibitors (Xanthohumol, Xan). Furthermore, histochemical staining was utilized to assess the morphological changes in the kidney. Xan was determined to be a potential inhibitor of TXNIP due to its low binding energy value of - 7.433 kcal/mol. Both genetic inhibition of TXNIP using sh-RNA and pharmacological inhibition with Xan were found to reverse HG-induced RTEC apoptosis and inflammatory response. In diabetic mice, administration of Xan resulted in significant improvements in pathological features such as tubular atrophy, tubular injury score, and collagen deposition in the tubulointerstitium. Additionally, treatment with Xan effectively reduced the up-regulation of TXNIP protein expression caused by hyperglycemia. In conclusion, Xan, as a bioactive natural product, has been shown to attenuate hyperglycemia-induced renal tubular injury in both in vitro and in vivo models, potentially through the inhibition of TXNIP expression. Xan has the potential to serve as a therapeutic compound for the treatment of DN.

Ferroptosis in senescence and age-related diseases: pathogenic mechanisms and potential intervention targets

As the global population continues to age, the prevalence of age-related diseases is increasing, significantly influencing social and economic development, the stability of social security systems, and progress in medical technology. Ferroptosis, a recently discovered form of programmed cell death driven by iron-dependent lipid peroxidation, has emerged as a key area of research. Studies have revealed a strong association between ferroptosis and senescence. In this article, we systematically summarize the molecular mechanisms and associated signaling pathways underlying ferroptosis, emphasizing its pivotal role in the onset and progression of age-related diseases. By providing new perspectives, we aim to advance understanding of the pathogenesis of age-related diseases and guide the development of effective intervention strategies.

Inhibition of tubular epithelial cells ferroptosis alleviates renal interstitial fibrosis by reducing lipid hydroperoxides and TGF-β/Smad signaling

BACKGROUND

Ferroptosis is a non-apoptotic form of regulated cell death that involves an imbalance in the homeostasis of two elements: iron and lipid hydroperoxides. The accumulation of lipid hydroperoxide serves as a key trigger for initiating ferroptosis. Recent studies have identified ferroptosis as a critical pathophysiology contributing to kidney disease progression. However, the specific mechanisms underlying the role of ferroptosis in chronic kidney disease (CKD) have not been elucidated.

METHODS

Tubular epithelial cells (TECs) ferroptosis was evaluated in unilateral ureteral obstruction (UUO) models and in TGF-β-treated HK-2 cells to explore the relationship between ferroptosis and fibrosis. Ferroptosis inhibitors (ferrostatin-1) and TECs-targeted glutathione peroxidase 4 (GPX4) overexpression in vivo and in vitro were used to investigate the effect and mechanism of TECs ferroptosis on fibrosis progression.

RESULTS

Our findings indicate that ferroptosis is persistently activated during various states of the UUO model. As the results, ferroptosis was identified as a core facilitator of renal interstitial fibrosis in TECs during UUO. The reduction in TECs ferroptosis significantly ameliorated renal fibrosis and maintained the structure in the proximal tubules. Persistent activation of TECs ferroptosis effectively aggravated fibrosis progression through the TGF-β/Smad pathway.

CONCLUSIONS

Inhibiting ferroptosis effectively rescues the accumulation of profibrotic cytokines, thereby alleviating renal fibrosis. The profibrotic mechanism of ferroptosis is closely related to the TGF-β/Smad pathway, and targeting ferroptosis and increasing GPX4 expression could be an effective strategy for treating CKD.

Iron and ferroptosis in kidney disease: molecular and metabolic mechanisms

Maintaining iron homeostasis is necessary for kidney functioning. There is more and more research indicating that kidney disease is often caused by iron imbalance. Over the past decade, ferroptosis' role in mediating the development and progression of renal disorders, such as acute kidney injury (renal ischemia-reperfusion injury, drug-induced acute kidney injury, severe acute pancreatitis induced acute kidney injury and sepsis-associated acute kidney injury), chronic kidney disease (diabetic nephropathy, renal fibrosis, autosomal dominant polycystic kidney disease) and renal cell carcinoma, has come into focus. Thus, knowing kidney iron metabolism and ferroptosis regulation may enhance disease therapy. In this review, we discuss the metabolic and molecular mechanisms of iron signaling and ferroptosis in kidney disease. We also explore the possible targets of ferroptosis in the therapy of renal illness, as well as their existing limitations and future strategies.

Enhanced ferroptosis sensitivity promotes the formation of highly myopic cataract via the DDR2-Hippo pathway

Highly myopic cataract (HMC) is a leading cause of blindness among the working-age individuals, with its pathogenesis poorly understood. This study aimed to elucidate the role of ferroptosis in HMC development as well as the underlying mechanisms. In HMC lens epithelia, levels of Fe2+ and lipid peroxidation were found elevated, with increased vulnerability towards ferroptosis as revealed by transmission electron microscopy. Mechanistically, RNA sequencing of HMC lens epithelial samples identified up-regulated expression of discoidin domain receptor tyrosine kinase 2 (DDR2) as a key factor, which could enhance ferroptosis sensitivity via the Src-Hippo pathway. Specifically, DDR2 interacted with Src kinase, leading to the nuclear translocation of homologous transcriptional regulators (yes-associated protein 1 [YAP1] and WW domain containing transcription regulator 1 [WWTR1]) of the Hippo pathway, which altered the expression level of ferroptosis-related genes. Notably, highly myopic eyes of mice exhibited higher sensitivity to RSL3, a ferroptosis inducer, manifested as more severe nuclear lens opacities both in vitro and in vivo compared with the contralateral control eyes, which could be alleviated by inhibitors of either ferroptosis or DDR2. Altogether, these findings highlighted the role of DDR2 in mediating ferroptosis in HMC formation, providing a novel insight for therapeutic interventions.

The mutualistic relationship between M2c macrophages of TGFβ1 induction and gastric cancer cells: the correlation between protective mechanisms in the tumor microenvironment and polarization of subtypes of cells

Background: Gastric cancer (GC) is one of the most common malignant tumors worldwide, with fast metastasis and high mortality rate. GC cells and tumor immune microenvironment exhibit high heterogeneity. Multiple pieces of evidence suggest that TGFβ1 intervenes in the tumor microenvironment, immune cells and GC prognosis. The aim of this study is to comprehensively investigate the functional intervention of macrophage polarization subtypes on gastric cancer cell lines in the GC tumor microenvironment, providing valuable insights into tumor microenvironment research and potential targets for treatment strategies. Methods: TCGA database and multiple GEO datasets were used to validate the role of TGFβ1 in cancer prognosis, immune infiltration and subtype macrophage polarization. Construct different subtypes of macrophages and establish cell co culture systems using Transwell chambers. Enzyme linked immunosorbent assay (ELISA), western blotting (WB) and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were used to verify the changes in the metastatic function and defense mechanism of gastric cancer cells (Hgc27 and MKN45) in different co culture systems. Further analyze the effect of gastric cancer cell metabolites on macrophage subtype polarization. Results: TGFβ1 was highly expressed in GC tissues, highly expressed TGFβ1 could reduce the survival time of GC patients. The GC immune infiltration results confirmed the correlation between TGFβ1 and M2 macrophages. The GEO dataset results of gastric cancer at different stages showed that some M2 macrophage markers showed consistent changes with TGFβ1. The WB, ELISA and RT-qPCR have identified TGFβ1-induced polarization of M2c macrophages, most biomarkers are associated with M2c. M2c macrophages can enhance cell migration and function, can inhibit ferroptosis in gastric cancer cells, endowing them with stronger special environmental resistance. Gastric cancer cells tend to polarize towards M2 macrophages, with M2c being the main M2 subtype of macrophages. Conclusion: In conclusion, our study reveals a mutually beneficial symbiotic relationship between M2c macrophages and cancer cells in the microenvironment of gastric cancer tumors. TGFβ1 promotes the production of M2c macrophages, which enhance the function and ferroptosis resistance of gastric cancer cells. Gastric cancer cells provide the material basis for M2c macrophage polarization. This new evidence may provide new insights into developing more effective targeted therapies for gastric cancer to combat the formation of immune escape and metastasis in gastric cancer.

Fabry Disease Podocytes Reveal Ferroptosis as a Potential Regulator of Cell Pathology

Introduction

Fabry disease (FD) results from pathogenic GLA variants, leading to a deficiency in lysosomal α-galactosidase A (α-Gal A) and accumulation of the sphingolipid globotriaosylceramide (Gb3). This leads to severe renal and cardiovascular complications, primarily affecting kidney podocytes. As a multisystemic disorder, FD initiates at the cellular level; however, the mechanism(s) underlying Gb3-induced cell dysfunction remain largely unknown. This study aimed to identify potential drivers of FD and explore the underlying cell pathology in induced pluripotent stem cell (iPSC)-derived podocytes from patients with FD.

Methods

iPSCs were derived from patients with FD with GLA c.851T>C or GLA c.1193_1196del variants and compared with controls or CRISPR-Cas9-corrected cell lines. iPSCs were differentiated into podocytes; and α-Gal A activity, Gb3 accumulation, and cell morphology were assessed. Label-free mass spectrometry identified the top, differentially expressed proteins which were validated by using western blot.

Results

Podocytes derived from patients with FD exhibited expression of podocyte-specific markers and morphological features of FD. Reduced α-Gal A activity was observed in FD iPSC-derived podocytes along with the accumulation of Gb3. Proteomic profiling revealed distinct proteomic signatures between control and iPSC-derived podocytes from a patient with FD, with apparent variations among FD lines, highlighting GLA variant-specific proteomic alterations. Notably, the ferroptosis-associated protein, arachidonate 15-lipoxygenase (ALOX15), was the most upregulated protein in FD podocytes and ferroptosis was the most enriched pathway. Western blot analysis confirmed the upregulation of ALOX15 in FD podocytes, with validation of other markers implicating ferroptosis in FD pathology.

Conclusion

These findings underscore the heterogeneity of FD and, for the first time, implicate ferroptosis as a potential common pathway driving its pathology.

Naringenin Inhibits Ferroptosis in Renal Tubular Epithelial Cells of Diabetic Nephropathy Through SIRT1/FOXO3a Signaling Pathway

Naringenin has the potential to regulate ferroptosis and mitigate renal damage in diabetic nephropathy (DN). However, it remains unclear whether the naringenin's effects in DN are linked to its ability to regulate ferroptosis. This study investigated the potential anti-ferroptosis properties of naringenin in high glucose (HG)-induced renal tubular epithelial cell models. HK-2 cells were cultured in HG medium to establish the DN cell model. HK-2 cells were treated with different doses of naringenin to explore the effect of naringenin. The CCK-8 results show that 50 μM ~ 200 μM of naringenin do not affect the viability of HK-2 cells and the viability of HG-induced HK-2 cells increase in a dose-dependent manner with naringenin treatment. Additionally, naringenin increased the levels of IL-10 while decreasing the levels of IL-1β, TNF-α, IL-6, and ROS in HG-induced HK-2 cells. Naringenin also reduced the levels of Fe2+, oxidized lipid ROS, MDA, 4-HNE, ACSL4, and TFR1 in HG-induced HK-2 cells, while increasing the levels of non-oxidized lipid ROS, SOD, GSH-Px, SLC7A11, and GPX4. Meanwhile, naringenin restored the levels of MMP, ATP and MPTP opening, reduced OCR in HG-induced HK-2 cells. Furthermore, naringenin reversed the decreased expression of SIRT1, p-FOXO3a, Nrf2 and Nuclear Nrf2 caused by HG. SIRT1 inhibitor EX527 and Nrf2 inhibitor ML385 attenuated the effects of naringenin on ferroptosis in HG-induced HK-2 cells, with EX527 demonstrating a stronger reversal effect on ferroptosis than ML385. These results suggest that naringenin inhibits ferroptosis in HG-induced HK-2 cells mainly through SIRT1/FOXO3a signaling pathway. This finding further enhanced our understanding of the mechanism behind naringenin's protective effect on DN.

Ferroptosis in kidney disease: a bibliometric analysis from 2012 to 2024

Background and aims

Ferroptosis, a novel concept of programmed cell death proposed in 2012, in kidney disease, has garnered significant attention based on evidence of abnormal iron deposition and lipid peroxidation damage in the kidney. Our study aim to examine the trends and future research directions in the field of ferroptosis in kidney disease, so as to further explore the target or treatment strategy for clinical treatment of kidney disease.

Material and Methods

A thorough survey using the Web of Science Core Collection, focusing on literature published between 2012 and 2024 examining the interaction between kidney disease and ferroptosis was conducted. VOSviewer, CiteSpace, and Biblioshiny were used for in-depth scientometric and visualized analyses.

Results

From 2012 to 2024, a total of 2,244 articles met the inclusion criteria for final analysis. The number of annual publications in this area of study showed a steady pattern at the beginning of the decade. The top 3 journals with the highest publication output were Renal Failure, Oxidative Medicine And Cellular Longevity, and Biomedicine & Pharmacotherapy. China and the United States had the highest number of publications. Central South University and Guangzhou Medical University as the most active and influential institutions. Documents and citation analysis suggested that Andreas Linkermann, Jolanta Malyszko, and Alberto Ortiz are active researchers, and the research by Scott J. Dixon and Jose Pedro Friedmann Angeli, as the most cited article, are more important drivers in the development of the field. Keywords associated with glutathione, lipid peroxidation, and nitric oxide had high frequency in the early studies. In recent years, however, there has been a shift towards biomarkers, inflammation and necrosis, which indicate current and future research directions in this area.

Conclusion

The global landscape of the ferroptosis research in kidney disease from 2012 to 2024 was presented. Basic research and mechanism exploration for renal fibrosis and chronic kidney disease may be a hot spot in the future.

Danshen injection ameliorates unilateral ureteral obstruction-induced renal fibrosis by inhibiting ferroptosis via activating SIRT1/GPX4 pathway

Introduction

The pathogenesis of renal fibrosis is related to blood stasis, and the method of promoting blood circulation and removing blood stasis is often used as the treatment principle. Danshen injection (DSI) is a commonly used drug for promoting blood circulation and removing blood stasis in clinic. However, whether DSI slows the progression of renal fibrosis or the potential mechanism is uncertain.

Methods

We investigated renal fibrosis models using UUO mice and TGF-β stimulation in HK-2 cells.

Results

Our findings revealed that DSI or Fer-1 alleviated kidney injury by ameliorating renal morphology injury and pathological injury in vivo. Besides, DSI or Fer-1 inhibited renal fibrosis in vivo and in TGF-β-induced HK-2 cells. Furthermore, ferroptosis was lessened under DSI or Fer-1 treatment. More importantly, the DSI active ingredients (danshensu, salvianolic acid B, protocatechuic aldehyde, caffeic acid and tanshinone IIA) could bind to SIRT1. The protein levels of SIRT1 and GPX4 were downregulated accompanied by the incremental concentrations of TGF-β or Erastin, which were repaired by DSI or Fer-1 intervention. However, the inhibition of ferroptosis and renal fibrosis owing to DSI were reversed by SIRT1 inhibitor EX527.

Conclusion

Taken together, our results indicated that DSI could protect against ferroptosis to attenuate renal fibrosis by activating the SIRT1/GPX4 pathway. It is expected to be a potential agent to treat renal fibrosis.

Exploring Liraglutide's mechanism in reducing renal fibrosis: the Fsp1-CoQ10-NAD(P)H pathway

Studies have confirmed that elevated glucose levels could lead to renal fibrosis through the process of ferroptosis. Liraglutide, a human glucagon-like peptide-1 (GLP-1) analogue, is a potential treatment option for diabetes. This study aimed to examine the potential of liraglutide (LIRA) in inhibiting ferroptosis and reducing high glucose-induced renal fibrotic injury in mice, and whether the Fsp1-CoQ10-NAD(P)H signal pathway is a mechanism for this effect. In our study, we used db/db mice to simulate Type 2 diabetes mellitus (T2DM). The mice were intraperitoneally injected with LIRA (200 µg/kg/d) daily for 6 weeks. Renal function, pathologic changes, lipid peroxidation levels, iron levels, and ferroptosis were assessed. First, LIRA ameliorated renal dysfunction and fibrosis in db/db mice. Second, LIRA inhibited lipid peroxidation by up-regulating T-SOD, GSH-Px, and GSH activities as well as down-regulating the levels of 8-OHDG, MDA, LPO, 4-HNE, 12-Lox, and NOX4 in db/db mice. In addition, LIRA attenuated iron deposition by decreasing the expression of TfR1 and increasing the expression of FPN1. Meanwhile, LIRA reduced high levels of high glucose-induced cell viability decline and intracellular lipid peroxidation. Furthermore, LIRA inhibited ferroptosis by adjusting the Fsp1-CoQ10-NAD(P)H pathway in vivo and in vitro. These findings suggested that LIRA attenuated kidney fibrosis injury in db/db mice by inhibiting ferroptosis through the Fsp1-CoQ10-NAD(P)H pathway.

Empagliflozin attenuates renal tubular ferroptosis in preeclampsia via tazarotene-induced gene 1

Preeclampsia (PE) is a serious pregnancy complication characterized by elevated blood pressure and a major cause of maternal and perinatal morbidities, also known to increase the risk of chronic kidney disease. Mechanisms underlying PE-induced kidney injury remain unclear. Anti-angiotensin II type 1 receptor agonistic autoantibody (AT1-AA) is reported to participate in the pathogenesis of PE-induced kidney injury. Our previous study replicated the major features of PE in pregnant mice by administration of intravenous injection of AT1-AA and found that podocyte senescence plays a role in PE-induced kidney injury. Elevated levels of N-acetyl-β-D glucosaminidase (NAG) and kidney injury molecule-1 (KIM-1) in the urine of patients with PE have been reported, indicating renal tubular injury. In this study, we identified the role of renal proximal tubular epithelial cells (PTECs) in PE-induced kidney injury and the therapeutic value of empagliflozin, an anti-diabetic agent, in a murine model of AT1-AA-induced PE. In our study, higher tubular injury score (Control vs. PE: P < 0.0001) show that PTECs are damaged in AT1-AA-induced PE. We identified ferroptosis as one of the cause of AT1-AA-induced PTEC injury by RNAseq, and confirmed the involvement of ferroptosis by detecting ferrous iron (Control vs. PE: P < 0.0001), reduced glutathione (GSH) (Control vs. PE: P < 0.0001) and lipid peroxidation (Control vs. PE: P < 0.0001). Empagliflozin ameliorates AT1-AA-induced PTEC ferroptosis and injury in PE. Furthermore, we demonstrated that tazarotene-induced gene 1 is involved in AT1-AA-induced PTEC injury. These findings suggest that renal tubules are injured in PE and empagliflozin has therapeutic potential for PE-induced PTEC injury.

GLP-1 Receptor Agonists Alleviate Diabetic Kidney Injury via β-Klotho-Mediated Ferroptosis Inhibition

Semaglutide (Smg), a GLP-1 receptor agonist (GLP-1RA), shows renal protective effects in patients with diabetic kidney disease (DKD). However, the exact underlying mechanism remains elusive. This study employs transcriptome sequencing and identifies β-Klotho (KLB) as the critical target responsible for the role of Smg in kidney protection. Smg treatment alleviates diabetic kidney injury by inhibiting ferroptosis in patients, animal models, and HK-2 cells. Notably, Smg treatment significantly increases the mRNA expression of KLB through the activation of the cyclic adenosine monophosphate (cAMP) signaling pathway, specifically through the phosphorylation of protein kinase A (PKA) and cAMP-response element-binding protein (CREB). Subsequently, the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway is activated, reprograming the key metabolic processes of ferroptosis such as iron metabolism, fatty acid synthesis, and the antioxidant response against lipid peroxidation. Suppression of ferroptosis by Smg further attenuates renal inflammation and fibrosis. This work highlights the potential of GLP-1RAs and KLB targeting as promising therapeutic approaches for DKD management.

Radish red attenuates chronic kidney disease in obese mice through repressing oxidative stress and ferroptosis via Nrf2 signaling improvement

Chronic kidney disease (CKD) presents a significant public health concern, with obesity being a prominent contributing factor to kidney disorders by inducing oxidative stress, lipotoxicity, and tubular cell injury. Natural anthocyanins extracted from red radishes (Raphanus sativus L.) exert antioxidant and anti-apoptotic functions. This study aims to employ a novel natural pigment anthocyanin, referred to as radish red (RR) isolated from red radishes, to alleviate obesity-related metabolic disturbances and kidney impairment in a CKD mouse model induced by high-fat and high-fructose diets (HFFD). The in vitro study initially demonstrated that RR treatment significantly mitigated the palmitate acid (PA)-induced injury and cytotoxicity in human tubular epithelial HK2 cells. Subsequently, RR supplementation notably improved obesity and associated metabolic dysfunctions in mice caused by HFFD. Abnormal renal function indices including serum creatinine, blood urea nitrogen (BUN), uric acid (UA), urine protein, albuminuria and urine albumin-to-creatinine ratio (UACR) were detected in HFFD-fed mice, which were effectively alleviated by RR treatment. Histologically, renal tubular cell injury, lipid deposition, tubular dilatation, and renal fibrosis induced by HFFD were markedly improved after RR administration in mice. Furthermore, RR treatment significantly alleviated oxidative stress in HFFD-fed mice, as evidenced by the decreased renal reactive oxygen species (ROS) production, 4-HNE, and NOX4 expression levels. Anti-oxidants such as superoxide dismutase-1 (SOD1), NAD (P) H: quinone oxidoreductase (NQO1), heme oxygenase-1 (HO-1) and glutamate cysteine ligase (GCLC) were highly upregulated in kidney of HFFD-fed mice with RR consumption through improving NFE2-related factor 2 (Nrf2) signaling activation. Furthermore, ferroptosis was identified in the kidneys of HFFD-fed mice, evidenced by the elevated levels of malondialdehyde (MDA), iron content, and lipid peroxidation, along with the decreased expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). These occurrences were significantly mitigated following RR treatment. Mechanistically, we further discovered that the suppressive effects of RR in restricting oxidative stress, ferroptosis, lipid accumulation, and injury of tubular epithelial cells induced by PA were significantly counteracted by Nrf2 knockdown. Collectively, our results demonstrated that dietary supplementation with RR could potentially serve as an efficacious therapeutic modality for the management of obesity-related CKD progression by enhancing Nrf2 activation to impede oxidative stress and ferroptosis.

Nuclear Factor Erythroid 2-Related Factor 2 Activator DDO-1039 Ameliorates Podocyte Injury in Diabetic Kidney Disease via Suppressing Oxidative Stress, Inflammation, and Ferroptosis

Aims: Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease, and podocyte injury is one of the major contributors to DKD. As a crucial transcriptional factor that regulates cellular response to oxidative stress, nuclear factor erythroid 2-related factor 2 (Nrf2) is an attractive therapeutic target for DKD. In this study, we evaluated the therapeutic potential of DDO-1039, a novel small-molecule Nrf2 activator developed with protein-protein interaction strategy, on podocyte injury in DKD. Results: DDO-1039 treatment significantly increased Nrf2 protein level and Nrf2 nuclear translocation, thereby upregulating Nrf2 target genes [heme oxygenase 1, NAD(P)H quinone dehydrogenase 1, glutamate-cysteine ligase modifier, and tyrosine-protein kinase receptor] both in vitro and in vivo. DDO-1039 attenuated glomerular sclerosis and podocyte injury in the high-fat diet/streptozotocin-induced (HFD/STZ) diabetic mice and db/db diabetic mice. It also significantly improved hyperglycemia in both diabetic mice and mitigated proteinuria in HFD/STZ mice. Meanwhile, DDO-1039 attenuated oxidative stress and inflammation as well as apoptosis in vivo and in podocytes stimulated with palmitic acid and high glucose. Interestingly, we identified podocyte protective factor Tyro3 as a novel Nrf2-regulated gene. In addition, podocyte ferroptosis is reduced via activation of glutathione peroxidase 4 by the novel Nrf2 activator. Innovation and conclusion: DDO-1039 activates the Nrf2-based cytoprotective system to mitigate podocyte injury in the context of diabetes, suggesting the potential of DDO-1039 in the treatment of DKD. Antioxid. Redox Signal. 00, 000-000.

Targeting programmed cell death in diabetic kidney disease: from molecular mechanisms to pharmacotherapy

Diabetic kidney disease (DKD), one of the most prevalent microvascular complications of diabetes, arises from dysregulated glucose and lipid metabolism induced by hyperglycemia, resulting in the deterioration of renal cells such as podocytes and tubular epithelial cells. Programmed cell death (PCD), comprising apoptosis, autophagy, ferroptosis, pyroptosis, and necroptosis, represents a spectrum of cell demise processes intricately governed by genetic mechanisms in vivo. Under physiological conditions, PCD facilitates the turnover of cellular populations and serves as a protective mechanism to eliminate impaired podocytes or tubular epithelial cells, thereby preserving renal tissue homeostasis amidst hyperglycemic stress. However, existing research predominantly elucidates individual modes of cell death, neglecting the intricate interplay and mutual modulation observed among various forms of PCD. In this comprehensive review, we delineate the diverse regulatory mechanisms governing PCD and elucidate the intricate crosstalk dynamics among distinct PCD pathways. Furthermore, we review recent advancements in understanding the pathogenesis of PCD and explore their implications in DKD. Additionally, we explore the potential of natural products derived primarily from botanical sources as therapeutic agents, highlighting their multifaceted effects on modulating PCD crosstalk, thereby proposing novel strategies for DKD treatment.

Ferroptosis and its impact on common diseases

Ferroptosis is a novel form of programmed cell death characterized by iron accumulation, lipid peroxidation, and a decline in antioxidant capacity, all of which are regulated by gene expression. The onset of numerous diseases is closely associated with ferroptosis. Common diseases affect a large population, reduce the quality of life, and impose an increased burden on the healthcare system. The role of ferroptosis in common diseases, its therapeutic potential, and even its translation into clinical drug treatments are currently significant research topics worldwide. This study preliminarily explores the theoretical basis of ferroptosis, its mechanism and treatment prospect in common diseases including ischaemia-reperfusion injury, inflammatory bowel diseases, liver fibrosis, acute kidney injury, diabetic kidney disease, stroke, Alzheimer's disease, cardiovascular disease, immune and cancer. This review provides a theoretical foundation for the further study and development of ferroptosis, as well as for the prevention and treatment of common diseases.

The association between vitamin D receptor gene polymorphism FokI and type 2 diabetic kidney disease and its molecular mechanism: a case control study

BACKGROUND

The role of the vitamin D receptor single nucleotide polymorphism FOKI (VDR-FOKI) (rs2228570) in genetic susceptibility to type 2 diabetic kidney disease (T2DKD) remains uncertain. This study investigated the relationship between VDR-FOKI and T2DKD within the Chinese Plateau Han population and analyzed the underlying mechanisms.

METHODS

A total of 316 subjects were enrolled, including 44 healthy adults, 114 individuals with type 2 diabetes mellitus (T2DM), and 158 patients with T2DKD. According to the 2023 American Diabetes Association Diabetes Guidelines, patients with T2DKD were categorized into low-medium-risk and high-risk groups based on estimates of glomerular filtration rate and urinary albumin-to-creatinine ratio. The VDR-FokI genotypes of all participants were identified using the Taqman probe and classified as homozygous mutant genotypes (C/C or FF), heterozygous mutant genotypes (C/T or Ff), and homozygous wild genotypes (T/T or ff). Plasma levels of malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase activity (SOD) were assessed in T2DKD patients with FF and ff genotypes. Additionally, the levels of plasma VDR, GPX4, and P53 were determined using ELISA, while the relative expressions of VDR mRNA, GPX4 mRNA, and TP53 mRNA in whole blood were measured by RT-qPCR.

RESULTS

The T2DM patients with the ff genotype exhibited a 2.93-fold increased likelihood of developing T2DKD compared to those with the FF genotype (ORadjusted = 2.93; 95% CI: 1.142-7.513). Additionally, they were 2.01 times more likely to develop T2DKD than individuals with the FF and Ff genotypes (ORadjusted = 2.01; 95% CI: 1.008-4.006). However, no significant differences in VDR-FokI genotype distribution were observed between the healthy control group and the T2DM group, as well as between the low-medium-risk and high-risk groups of T2DKD. Furthermore, T2DKD patients with the ff genotype had significantly higher plasma levels of MDA compared to those with the FF genotype. In contrast, plasma GSH and SOD content was significantly lower in the ff genotype patients (P < 0.05). Additionally, the GPX4 concentration in ff genotype patients was significantly lower than in FF genotype patients [14.88 (11.32,22.39) vs. 12.76 (8.55,13.75), P = 0.037]. Nevertheless, no statistically significant difference was observed in the expression of VDRmRNA, GPX4mRNA, TP53mRNA, plasma VDR, and plasma P53.

CONCLUSIONS

The ff genotype of VDR-FokI is a risk factor for T2DKD, and the potential mechanism may be related to ferroptosis. However, It is not associated with T2DM or the progression of T2DKD.

Targeting ferroptosis as a prospective therapeutic approach for diabetic nephropathy

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus, causing a substantive threat to the public, which receives global concern. However, there are limited drugs targeting the treatment of DN. Owing to this, it is highly crucial to investigate the pathogenesis and potential therapeutic targets of DN. The process of ferroptosis is a type of regulated cell death (RCD) involving the presence of iron, distinct from autophagy, apoptosis, and pyroptosis. A primary mechanism of ferroptosis is associated with iron metabolism, lipid metabolism, and the accumulation of ROS. Recently, many studies testified to the significance of ferroptosis in kidney tissue under diabetic conditions and explored the drugs targeting ferroptosis in DN therapy. Our review summarized the most current studies between ferroptosis and DN, along with investigating the significant processes of ferroptosis in different kidney cells, providing a novel target treatment option for DN.

Quercetin improves diabetic kidney disease by inhibiting ferroptosis and regulating the Nrf2 in streptozotocin-induced diabetic rats

Diabetic kidney disease (DKD) is a leading factor in end-stage renal disease. The complexity of its pathogenesis, combined with the limited treatment efficacy, necessitates deeper insights into potential causes. Studies suggest that ferroptosis-driven renal tubular damage contributes to DKD's progression, making its counteraction a potential therapeutic strategy. Quercetin, a flavonoid found in numerous fruits and vegetables, has demonstrated DKD mitigation in mouse models, though its protective mechanism remains ambiguous. In this study, we delved into quercetin's potential anti-ferroptotic properties, employing a DKD rat model and high glucose (HG)-treated renal tubular epithelial cell models. Our findings revealed that HG prompted unusual ferroptosis activation in renal tubular epithelial cells. However, quercetin counteracted this by inhibiting ferroptosis and activating NFE2-related factor 2 (Nrf2) expression in both DKD rats and HG-treated HK-2 cells, indicating its renal protective role. Further experiments, both in vivo and in vitro, validated that quercetin stimulates Nrf2. Thus, our research underscores quercetin's potential in DKD treatment by modulating the ferroptosis process via activating Nrf2 in a distinct DKD rat model, offering a fresh perspective on quercetin's protective mechanisms.

Regulation of pyroptosis and ferroptosis by mitophagy in chronic kidney disease

Chronic kidney disease (CKD) is a chronic progressive disease characterized by kidney injury or declining renal function. With its insidious onset and significant harm, CKD has become a major global public health concern. Abnormal cell death can directly or indirectly contribute to kidney injury, among which excessive pyroptosis and ferroptosis are central events in CKD pathogenesis. These two forms of cell death may interact through mechanisms such as reactive oxygen species release, further aggravating renal damage. Mitophagy, a selective autophagic process that removes damaged mitochondria, plays an important role in maintaining cellular homeostasis. In CKD, mitophagy is impaired; however, enhancing mitophagy signaling pathways can alleviate inflammation, reduce iron accumulation and lipid peroxidation in renal cells. This suggests that mitophagy may be a key regulator of pyroptosis and ferroptosis in kidney cells and holds potential as a novel target for the prevention, diagnosis, and treatment of CKD.

Human Umbilical Cord Mesenchymal Stem Cells Alleviate Diabetic Nephropathy by Inhibiting Ferroptosis via the JNK/KEAP1/NRF2 Signaling Pathway

Aims: Diabetic nephropathy (DN) is a major cause of end-stage renal disease, with no therapeutic interventions available to control its progression. Ferroptosis, an iron-dependent regulated cell death characterized by lipid peroxidation, plays a pivotal role in the pathogenesis of DN. Human umbilical cord mesenchymal stem cells (hUCMSCs) are an effective treatment modality for DN; however, the underlying mechanism of action remains unclear. The aim of the present study was to investigate whether hUCMSCs alleviate DN via inhibiting ferroptosis and its molecular mechanisms in type 2 diabetic mice and high-glucose and palmitate-stimulated human renal tubular epithelial cell (HK-11) models. Results: Our findings revealed that hUCMSCs improved the renal structure and function and tubular injuries. HUCMSC treatment can inhibit ferroptosis by decreasing iron content, reducing reactive oxygen species, malondialdehyde and 4-hydroxynonenal generation, decreasing the expression of positive ferroptosis mediator transferrin receptor 1 and long-chain acyl-CoA synthetase 4, and enhancing the expression of negative ferroptosis mediators (i.e., ferritin heavy chain, glutathione peroxidase 4, and system Xc-cystine/glutamate reverse transporter). Mechanistically, hUCMSC treatment inhibited c-Jun N-terminal kinase (JNK) and Kelch-like ECH-associated protein 1 (KEAP1) activation while increasing the expression of nuclear factor erythroid 2-related factor 2 (NRF2). Furthermore, pretreatment of HK-11 cells with NRF2 siRNA, the JNK inhibitor SP600125, or the JNK agonist anisomycin demonstrated the regulation of the JNK/KEAP1/NRF2 signaling pathway by hUCMSCs. Innovation and Conclusion: HUCMSCs inhibit ferroptosis in DN via the JNK/KEAP1/NRF2 signaling pathway, providing a new perspective and scientific evidence for treating DN. Antioxid. Redox Signal. 00, 000-000.

A new strategy for Astragaloside IV in the treatment of diabetic kidney disease: Analyzing the regulation of ferroptosis and mitochondrial function of renal tubular epithelial cells

In China, the Astragalus membranaceus root is used to treat chronic kidney disease. Astragaloside IV (AS-IV), the primary bioactive compound, exhibits anti-inflammatory and antioxidative properties; however, its renoprotective mechanism in diabetic kidney disease (DKD) remains unclear. The study aimed to investigate the protective effects of AS-IV on DKD revealing the underlying mechanisms. We established an early diabetic rat model by feeding a high-fat diet and administering low-dose streptozotocin. Twelve weeks post-treatment, renal function was evaluated using functional assays, histological analyses, immunohistochemistry, western blotting, and transmission electron microscopy. HK-2 cells exposed to high glucose conditions were used to examine the effect of AS-IV on oxidative stress, iron levels, reactive oxygen species (ROS), and lipid peroxidation. Network pharmacology, proteomics, molecular docking, and molecular dynamics simulation techniques were employed to elucidate the role of AS-IV in DKD. The results revealed that AS-IV effectively enhanced renal function and mitigated disease pathology, oxidative stress, and ferroptosis markers in DKD rats. In HK-2 cells, AS-IV lowered the levels of lipid peroxides, Fe2+, and glutathione, indicating the repair of ferroptosis-related mitochondrial damage. AS-IV reduced mitochondrial ROS while enhancing mitochondrial membrane potential and ATP production, indicating its role in combating mitochondrial dysfunction. Overall, in silico analyses revealed that AS-IV interacts with HMOX1, FTH1, and TFR1 proteins, supporting its efficacy in alleviating renal injury by targeting mitochondrial dysfunction and ferroptosis. AS-IV may play a renoprotective role by regulating mitochondrial dysfunction and inhibiting. HMOX1/FTH1/TFR1-induced ferroptosis. Accordingly, AS-IV could be developed for the clinical treatment of DKD-related renal injury.

Pathological Characteristics of Ferroptosis in Kidney Tissues in Type 2 Diabetic Patients with Diabetic Kidney Disease

Background

Diabetes kidney disease (DKD) is a common complication of diabetes and is currently considered the primary cause of end-stage renal disease. Ferroptosis has been found to participate in the development of DKD. However, no ferroptosis-related markers have been evaluated in human DKD samples. This study aimed to examine the ferroptosis-related pathological alterations in DKD samples.

Methods

This study enrolled patients with DKD at the Third Hospital of Hebei Medical University between January 2018 and December 2022, of whom 30 were diagnosed with DKD and 10 with non-DKD (CON). Clinical data of patients were collected, and hematoxylin-eosin staining (H&E), PASM, and immunohistochemical staining were performed to evaluate pathological changes and the expression of ferroptosis-related proteins, including GPX4, ACSL4, Nrf2, TfR1, FTH, and FTL.

Results

Compared with the CON group, patients with DKD exhibited significantly elevated serum creatinine levels and reduced eGFR (P < 0.05). Iron content and the expression of the ferroptosis-related protein ACSL4 were significantly increased, while the expression of Nrf2 was significantly decreased in the renal tissues of patients with DKD (P all < 0.05). There were no differences in the expression of GPX4, TfR1, FTH, or FTL between the two groups. Nrf2 and ACSL4 expression were influential factors in the occurrence of DKD and both exhibited diagnostic value for DKD. Nrf2 was a protective factor (OR, < 1), whereas ACSL4 was a risk factor (OR, > 1).

Conclusion

Ferroptosis-promoting gene profile was identified in DKD renal samples, indicating that ferroptosis may participate in the pathogenesis of DKD. The expression levels of Nrf2 and ASCL4 in the kidneys are related to the severity and progression of DKD.

Regulated cell death in chronic kidney disease: current evidence and future clinical perspectives

Chronic kidney disease (CKD) is the progressive loss of kidney function/structure over a period of at least 3 months. It is characterised histologically by the triad of cell loss, inflammation and fibrosis. This literature review focuses on the forms of cell death that trigger downstream inflammation and fibrosis, collectively called regulated cell death (RCD) pathways. Discrete forms of RCD have emerged as central mediators of CKD pathology. In particular, pathways of regulated necrosis - including mitochondrial permeability transition pore (mPTP)-mediated necrosis, necroptosis, ferroptosis and pyroptosis - have been shown to mediate kidney pathology directly or through the release of danger signals that trigger a pro-inflammatory response, further amplifying tissue injury in a cellular process called necroinflammation. Despite accumulating evidence in pre-clinical models, no clinical studies have yet targeted these RCD modes in human CKD. The review summarizes recent advances in our understanding of RCD pathways in CKD, looks at inter-relations between the pathways (with the emphasis on propagation of death signals) and the evidence for therapeutic targeting of molecules in the RCD pathways to prevent or treat CKD.

The biology of ferroptosis in kidney disease

Ferroptosis is a regulated cell death modality triggered by iron-dependent lipid peroxidation. Ferroptosis plays a causal role in the pathophysiology of various diseases, making it a promising therapeutic target. Unlike all other cell death modalities dependent on distinct signaling cues, ferroptosis occurs when cellular antioxidative defense mechanisms fail to suppress the oxidative destruction of cellular membranes, eventually leading to cell membrane rupture. Physiologically, only two such surveillance systems are known to efficiently prevent the lipid peroxidation chain reaction by reducing (phospho)lipid hydroperoxides to their corresponding alcohols or by reducing radicals in phospholipid bilayers, thus maintaining the integrity of lipid membranes. Mechanistically, these two systems are linked to the reducing capacity of glutathione peroxidase 4 (GPX4) by consuming glutathione (GSH) on one hand and ferroptosis suppressor protein 1 (FSP1, formerly AIFM2) on the other. Notably, the importance of ferroptosis suppression in physiological contexts has been linked to a particular vulnerability of renal tissue. In fact, early work has shown that mice genetically lacking Gpx4 rapidly succumb to acute renal failure with pathohistological features of acute tubular necrosis. Promising research attempting to implicate ferroptosis in various renal disease entities, particularly those with proximal tubular involvement, has generated a wealth of knowledge with widespread potential for clinical translation. Here, we provide a brief overview of the involvement of ferroptosis in nephrology. Our goal is to introduce this expanding field for clinically versed nephrologists in the hope of spurring future efforts to prevent ferroptosis in the pathophysiological processes of the kidney.

Suppression of ferroptosis through the SLC7A11/glutathione/glutathione peroxidase 4 axis contributes to the therapeutic action of the Tangshenning formula on diabetic renal tubular injury

BACKGROUND

Tangshenning (TSN) is a safe and effective formula to treat diabetic nephropathy (DN), and clinical studies have demonstrated that its therapeutic effects are related to oxidative stress improvements in patients. Herein, this study aims to explore the potential mechanism of how TSN alleviates diabetic renal tubular injury.

METHODS

The ultrahigh pressure liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-QTOF/MS) was used to identify the chemical composition and serum components of TSN. KK-Ay mice served to investigate the protective effects and regulatory mechanisms of TSN on tubular damage in DN. Furthermore, inhibitors and inducers of ferroptosis were employed in high glucose-cultured tubular epithelial cells (TECs) to verify the potential mechanisms of TSN. The expressions of proteins related to renal tubular injury, ferroptosis and solute carrier family 7, member 11 (SLC7A11)/glutathione (GSH)/glutathione peroxidase 4 (GPX4) axis were analyzed by western blot and immunofluorescence. Mitochondrial ultrastructure was observed in kidney tissues and TECs by a transmission electron microscope. Pathological changes in the renal tissues were observed by HE, PAS, and Prussian blue staining. Ferroptosis-related reactive oxygen species (ROS), malondialdehyde (MDA), ferrous ion, the intake of cystine, GSH, and oxidized glutathione (GSSG) were evaluated and contrasted in vivo or in vitro.

RESULTS

51 compounds of TSN powder and 11 components in TSN-containing serum were identified by UPLC-QTOF/MS method. Administration of TSN ameliorated the elevated levels of proteinuria, serum creatinine, blood urea nitrogen, abnormal expression of renal tubular injury markers, and pathological damage to the renal tubules in DN mice model. Intriguingly, a strong inhibition of ferroptosis after TSN treatment occurred in both DN mice model and high glucose-cultured TECs. Notably, induction of ferroptosis by erastin attenuated the protective effect of TSN in high glucose-cultured TECs, while the ferroptosis inhibition by ferrostatin-1 treatment protected renal tubular, which was similar to TSN, suggesting the contribution of TSN-mediated by the inhibition of ferroptosis in DN progression. Mechanistically, TSN upregulated the SLC7A11/GSH/GPX4 axis to inhibit ferroptosis.

CONCLUSION

TSN may delay the DN progression and attenuate the renal tubular injury by inhibiting the ferroptosis regulated by the SLC7A11/GSH/GPX4 axis.

Targeting Ferroptosis as an Advance Strategy in Cancer Therapy

Significance: This study innovates by systematically integrating the molecular mechanisms of iron death and its application in cancer therapy. By deeply analyzing the interaction between iron death and the tumor microenvironment, the study provides a new theoretical basis for cancer treatment and directions for developing more effective treatment strategies. In addition, the study points to critical issues and barriers that need to be addressed in future research, providing valuable insights into the use of iron death in clinical translation. Recent Advances: These findings are expected to drive further advances in cancer treatment, bringing patients more treatment options and hope. Through this paper, we see the great potential of iron death in cancer treatment and look forward to more research results being translated into clinical applications in the future to contribute to the fight against cancer. Critical Issues: In today's society, cancer is still one of the major diseases threatening human health. Despite advances in existing treatments, cancer recurrence and drug resistance remain a severe problem. These problems increase the difficulty of treatment and bring a substantial physical and mental burden to patients. Therefore, finding new treatment strategies to overcome these challenges has become significant. Future Directions: The study delved into the molecular basis of iron death in tumor biology. It proposed a conceptual framework to account for the interaction of iron death with the tumor immune microenvironment, guide treatment selection, predict efficacy, explore combination therapies, and identify new therapeutic targets to overcome cancer resistance to standard treatments, peeving a path for future research and clinical translation of ferroptosis as a potential strategy in cancer therapy. Antioxid. Redox Signal. 41, 616-636. [Figure: see text].

Advanced glycation end products and reactive oxygen species: uncovering the potential role of ferroptosis in diabetic complications

Advanced glycation end products (AGEs) are a diverse range of compounds that are formed when free amino groups of proteins, lipids, and nucleic acids are carbonylated by reactive carbonyl species or glycosylated by reducing sugars. Hyperglycemia in patients with diabetes can cause an overabundance of AGEs. Excess AGEs are generally acknowledged as major contributing factors to the development of diabetic complications because of their ability to break down the extracellular matrix directly and initiate intracellular signaling pathways by binding to the receptor for advanced glycation end products (RAGE). Inflammation and oxidative stress are the two most well-defined pathophysiological states induced by the AGE-RAGE interaction. In addition to oxidative stress, AGEs can also inhibit antioxidative systems and disturb iron homeostasis, all of which may induce ferroptosis. Ferroptosis is a newly identified contributor to diabetic complications. This review outlines the formation of AGEs in individuals with diabetes, explores the oxidative damage resulting from downstream reactions of the AGE-RAGE axis, and proposes a novel connection between AGEs and the ferroptosis pathway. This study introduces the concept of a vicious cycle involving AGEs, oxidative stress, and ferroptosis in the development of diabetic complications.

Ferroptosis at the nexus of metabolism and metabolic diseases

Ferroptosis, an iron-dependent form of regulated cell death, is emerging as a crucial regulator of human physiology and pathology. Increasing evidence showcases a reciprocal relationship between ferroptosis and dysregulated metabolism, propagating a pathogenic vicious cycle that exacerbates pathology and human diseases, particularly metabolic disorders. Consequently, there is a rapidly growing interest in developing ferroptosis-based therapeutics. Therefore, a comprehensive understanding of the intricate interplay between ferroptosis and metabolism could provide an invaluable resource for mechanistic insight and therapeutic development. In this review, we summarize the important metabolic substances and associated pathways in ferroptosis initiation and progression, outline the cascade responses of ferroptosis in disease development, overview the roles and mechanisms of ferroptosis in metabolic diseases, introduce the methods for ferroptosis detection, and discuss the therapeutic perspectives of ferroptosis, which collectively aim to illustrate a comprehensive view of ferroptosis in basic, translational, and clinical science.

PDK4-mediated Nrf2 inactivation contributes to oxidative stress and diabetic kidney injury

Diabetic kidney disease (DKD) is often featured with redox dyshomeostatis. Pyruvate dehydrogenase kinase 4 (PDK4) is the hub for DKD development. However, the mechanism by which PDK4 mediates DKD is poorly understood. The current work aimed to elucidate the relationship between PDK4 and DKD from the perspective of redox manipulation. Oxidative stress was observed in the human proximal tubular cell line (HK-2 cells) treated with a high concentration of glucose and palmitic acid (HGL). The mechanistic study showed that PDK4 could upregulate Kelch-like ECH-associated protein 1 (Keap1) in HGL-treated HK-2 cells through the suppression of autophagy, resulting in the depletion of nuclear factor erythroid 2-related factor 2 (Nrf2), the master regulator of redox homeostasis. At the cellular level, pharmacological inhibition or genetic knockdown of PDK4 could boost Nrf2, followed by the increase of a plethora of antioxidant enzymes and ferroptosis-suppression enzymes. Meanwhile, the inhibition or knockdown of PDK4 remodeled iron metabolism, further mitigating oxidative stress and lipid peroxidation. The same trend was observed in the DKD mice model. The current work highlighted the role of PDK4 in the development of DKD and suggested that PDK4 might be a promising target for the management of DKD.

The main molecular mechanisms of ferroptosis and its role in chronic kidney disease

The term ferroptosis, coined in 2012, has been widely applied in various disease research fields. Ferroptosis is a newly regulated form of cell death distinct from apoptosis, necrosis, and autophagy, the mechanisms of which have been extensively studied. Chronic kidney disease, characterized by renal dysfunction, is a common disease severely affecting human health, with its occurrence and development influenced by multiple factors and leading to dysfunction in multiple systems. It often lacks obvious clinical symptoms in the early stages, and thus, diagnosis is typically made in the later stages, complicating treatment. While research on ferroptosis and acute kidney injury has made continuous progress, studies on the association between ferroptosis and chronic kidney disease remain limited. This review aims to summarize chronic kidney disease, investigate the mechanism and regulation of ferroptosis, and attempt to elucidate the role of ferroptosis in the occurrence and development of chronic kidney disease.

The significance of ferroptosis in renal diseases and its therapeutic potential

Kidney diseases are significant global public health concern, with increasing prevalence and substantial economic impact. Developing novel therapeutic approaches are essential for delaying disease progression and improving patient quality of life. Cell death signifying the termination of cellular life, could facilitate appropriate bodily development and internal homeostasis. Recently, regulated cell death (RCD) forms such as ferroptosis, characterized by iron-dependent lipid peroxidation, has garnered attention in diverse renal diseases and other pathological conditions. This review offers a comprehensive examination of ferroptosis, encompassing an analysis of the involvement of iron and lipid metabolism, the System Xc - /glutathione/glutathione peroxidase 4 signaling, and additional associated pathways. Meanwhile, the review delves into the potential of targeting ferroptosis as a therapeutic approach in the management of acute kidney injury (AKI), chronic kidney disease (CKD), diabetic nephropathy, and renal tumors. Furthermore, it emphasizes the significance of ferroptosis in the transition from AKI to CKD and further accentuates the potential for repurposing drug and utilizing traditional medicine in targeting ferroptosis-related pathways for clinical applications. The integrated review provides valuable insights into the role of ferroptosis in kidney diseases and highlights the potential for targeting ferroptosis as a therapeutic strategy.

Ferroptosis and iron metabolism in diabetes: Pathogenesis, associated complications, and therapeutic implications

Diabetes mellitus is a complex chronic disease, considered as one of the most common metabolic disorders worldwide, posing a major threat to global public health. Ferroptosis emerges as a novel mechanism of programmed cell death, distinct from apoptosis, necrosis, and autophagy, driven by iron-dependent lipid peroxidation accumulation and GPx4 downregulation. A mounting body of evidence highlights the interconnection between iron metabolism, ferroptosis, and diabetes pathogenesis, encompassing complications like diabetic nephropathy, cardiomyopathy, and neuropathy. Moreover, ferroptosis inhibitors hold promise as potential pharmacological targets for mitigating diabetes-related complications. A better understanding of the role of ferroptosis in diabetes may lead to an improvement in global diabetes management. In this review, we delve into the intricate relationship between ferroptosis and diabetes development, exploring associated complications and current pharmacological treatments.

Ferroptosis and inflammation are modulated by the NFIL3-ACSL4 axis in sepsis associated-acute kidney injury

Sepsis-associated acute kidney injury (SA-AKI) increases the risk of death in patients with sepsis, and its major pathological change is the death of renal tubular cells. However, the mechanism of its occurrence remains unclear. Sepsis can lead to circadian dysregulation, and the rhythm gene NFIL3 has been reported to regulate lipid metabolism. There is compelling evidence that has demonstrated that lipid peroxidation can cause cellular ferroptosis. In this study, we established the in vitro and in vivo models of SA-AKI and confirmed the presence of ferroptosis of the renal tubular epithelial cells in SA-AKI. In addition, analysis of the GEO database showed that NFIL3 was highly expressed in sepsis patients and was highly correlated with the key molecule of ferroptosis, ACSL4. The in vitro and in vivo data suggested that NFIL3 was involved in ferroptosis and inflammation in SA-AKI. Subsequently, loss-of-function experiments revealed that NFIL3 knockdown attenuated ferroptosis and inflammation in renal tubular epithelial cells by downregulating ACSL4 expression, thus protecting SA-AKI. In conclusion, this study is the first to illustrate the involvement of the rhythm gene NFIL3 in SA-AKI, providing new insights and potential therapeutic targets for SA-AKI.

Functional mechanism of hypoxia-like conditions mediating resistance to ferroptosis in cervical cancer cells by regulating KDM4A SUMOylation and the SLC7A11/GPX4 pathway

The discovery of ferroptosis has unveiled new perspectives for cervical cancer (CC) management. We elucidated the functional mechanism of hypoxia-like conditions in CC cell ferroptosis resistance. CC cells were subjected to normoxia or hypoxia-like conditions, followed by erastin treatment to induce ferroptosis. The assessment of cell viability/ferroptosis resistance was performed by MTT assay/Fe2+, MDA, and glutathione measurement by colorimetry. KDM4A/SUMO1/Ubc9/SENP1 protein levels were determined by Western blot. Interaction and binding sites between KDM4A and SUMO1 were analyzed and predicted by immunofluorescence/co-immunoprecipitation and GPS-SUMO 1.0 software, with the target relationship verified by mutation experiment. SLC7A11/GPX4/H3K9me3 protein levels, and H3K9me3 level in the SLC7A11 gene promoter region were determined by RT-qPCR and Western blot/chromatin immunoprecipitation. H3H9me3/SLC7A11/GPX4 level alterations, and ferroptosis resistance after KDM4A silencing or KDM4A K471 mutation were assessed. Hypoxia-like conditions increased CC cell ferroptosis resistance and KDM4A, SUMO1, and Ubc9 protein levels, while it decreased SENP1 protein level. KDM4A and SUMO1 were co-localized in the nucleus, and hypoxia-like conditions promoted their interaction. Specifically, the K471 locus of KDM4A was the main locus for SUMO1ylation. Hypoxia-like conditions up-regulated SLC7A11 and GPX4 expression levels and decreased H3K9me3 protein level and H3K9me3 abundance in the SLC7A11 promoter region. KDM4A silencing or K471 locus mutation resulted in weakened interaction between KDM4A and SUMO1, elevated H3K9me3 levels, decreased SLC7A11 expression, ultimately, a reduced CC cell ferroptosis resistance. CoCl2-stimulated hypoxia-like conditions enhanced SUMO1 modification of KDM4A at the K471 locus specifically, repressed H3K9me3 levels, and up-regulated SLC7A11/GPX4 to enhance CC cell ferroptosis resistance.

Tanshinone IIA suppresses ferroptosis to attenuate renal podocyte injury in diabetic nephropathy through the embryonic lethal abnormal visual-like protein 1 and acyl-coenzyme A synthetase long-chain family member 4 signaling pathway

AIMS/INTRODUCTION

Tanshinone IIA (TIIA) is one of the main components of the root of the red-rooted Salvia miltiorrhiza Bunge. However, the molecular mechanisms underlying TIIA-mediated protective effects in diabetic nephropathy (DN) are still unclear.

MATERIALS AND METHODS

High glucose (HG)-induced mouse podocyte cell line (MPC5) cells were used as the in vitro model of DN and treated with TIIA. Cell viability, proliferation and apoptosis were detected using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide, 5-ethynyl-2'-deoxyuridine and flow cytometry assays. The protein levels were assessed using western blot assay. The levels of inflammatory factors were deleted by enzyme-linked immunoassay. Fe+ level, reactive oxygen species, malondialdehyde and glutathione products were detected using special assay kits. After ENCORI prediction, the interaction between embryonic lethal abnormal visual-like protein 1 (ELAVL1) and acyl-coenzyme A synthetase long-chain family member 4 (ACSL4) was verified using co-immunoprecipitation assay and dual-luciferase reporter assays. ACSL4 messenger ribonucleic acid expression was measured using real-time quantitative polymerase chain reaction.

RESULTS

TIIA repressed HG-induced MPC5 cell apoptosis, inflammatory response and ferroptosis. ACSL4 upregulation relieved the repression of TIIA on HG-mediated MPC5 cell injury and ferroptosis. ELAVL1 is bound with ACSL4 to positively regulate the stability of ACSL4 messenger ribonucleic acid. TIIA hindered HG-triggered MPC5 cell injury and ferroptosis by regulating the ELAVL1-ACSL4 pathway. TIIA blocked DN progression in in vivo research.

CONCLUSION

TIIA treatment restrained HG-caused MPC5 cell injury and ferroptosis partly through targeting the ELAVL1-ACSL4 axis, providing a promising therapeutic target for DN treatment.

Ferroptosis in renal fibrosis: a mini-review

Ferroptosis is a novel form of programmed cell death that is iron-dependent and distinct from autophagy, apoptosis, and necroptosis. It is primarily characterised by a decrease in glutathione peroxidase 4 (GPX4) activity, or by the accumulation of lipid peroxidation and reactive oxygen species (ROS). Renal fibrosis is a common pathological change in the progression of various primary and secondary renal diseases to end-stage renal disease and poses a serious threat to human health with high morbidity and mortality. Multiple pathways contribute to the development of renal fibrosis, with ferroptosis playing a crucial role in renal fibrosis pathogenesis due to its involvement in the production of ROS. Ferroptosis is related to several signalling pathways, including System Xc-/GPX4, abnormal iron metabolism and lipid peroxidation. A number of studies have indicated that ferroptosis is closely involved in the process of renal fibrosis caused by various kidney diseases such as glomerulonephritis, renal ischaemia-reperfusion injury, diabetic nephropathy and renal calculus. Identifying the underlying molecular mechanisms that determine cell death would open up new insights to address a therapeutic strategy to renal fibrosis. The review aimed to browse and summarise the known mechanisms of ferroptosis that may be associated with biological reactions of renal fibrosis.

Circulating inflammatory factors and risk causality associated with type 2 diabetic nephropathy: A Mendelian randomization and bioinformatics study

The main causative factors of diabetic nephropathy (DN), a common complication of diabetes mellitus, are metabolic abnormalities and hemodynamic changes. However, studies have shown that the immune-inflammatory response also plays an important role in DN pathogenesis. Therefore, in this study, we analyzed the causal relationship and immune infiltration between inflammatory factors and DN using Mendelian randomization (MR) and bioinformatics techniques. We analyzed the causal relationship between 91 inflammatory factors and DN using two-sample MR dominated by the results of inverse variance-weighted analysis. Based on the MR analysis, the immune mechanism of inflammatory factors in DN was further explored using immune cell infiltration analysis. MR analysis indicated a positive causal relationship between DN and IL1A, caspase 8 (CASP8), macrophage colony-stimulating factor 1, IL10, STAM-binding protein, and tumor necrosis factor ligand superfamily member 12 (TNFSF12) and a negative causal relationship between DN and cystatin D, fibroblast growth factor 19, neurturin, and TNFSF14. The pathogenic mechanism of CASP8 may involve the recruitment of CD4+ T cells and macrophages for DN infiltration. In this study, we found a causal relationship between DN and IL1A, CASP8, macrophage colony-stimulating factor 1, IL10, STAM-binding protein, TNFSF12, cystatin D, fibroblast growth factor 19, neurturin, and TNFSF14. Bioinformatic immune infiltration analysis further revealed that CASP8 regulates DN by influencing the infiltration of immune cells, such as T cells and macrophages.

Costunolide Inhibits Chronic Kidney Disease Development by Attenuating IKKβ/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 IKKβ 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 IKKβ acted as key regulatory factor in renal injury and the expression of IKKβ was increased in vitro and in vivo renal fibrosis model. Functionally, down-regulated IKKβ expression inhibits ferroptosis, inflammatory cytokine production and collagen deposition. Conversely, IKKβ overexpression exacerbates progressive renal fibrosis. Mechanistically, CTD alleviated renal fibrosis and inflammation by inhibiting the expression of IKKβ and attenuating IKKβ/NF-κB pathway.

Conclusion

This study demonstrates that CTD could mitigate renal fibrosis, ferroptosis and inflammation in CKD by modulating the IKKβ/NF-κB pathway, which indicates targeting IKKβ has an enormous potential for treating CKD.