Abnormal Iron and Lipid Metabolism Mediated Ferroptosis in Kidney Diseases and Its Therapeutic Potential

Exploring the role and therapeutic potential of lipid metabolism in acute kidney injury

Acute kidney injury (AKI) is a prevalent condition, yet no specific treatment is available. Extensive research has revealed the pivotal role of lipid-related alterations in AKI. Lipid metabolism plays an essential role in the sustenance of the kidneys. In addition to their energy-supplying function, lipids contribute to the formation of renal biomembranes and the establishment of the renal microenvironment. Moreover, lipids or their metabolites actively participate in signal transduction, which governs various vital biological processes, such as proliferation, differentiation, apoptosis, autophagy, and epithelial-mesenchymal transition. While previous studies have focused predominantly on abnormalities in lipid metabolism in chronic kidney disease, this review focuses on lipid metabolism anomalies in AKI. We explore the significance of lipid metabolism products as potential biomarkers for the early diagnosis and classification of AKI. Additionally, this review assesses current preclinical investigations on the modulation of lipid metabolism in the progression of AKI. Finally, on the basis of existing research, this review proposes future directions, highlights challenges, and presents novel targets and innovative ideas for the treatment of and intervention in AKI.

Berberine Inhibits KLF4 Promoter Methylation and Ferroptosis to Ameliorate Diabetic Nephropathy in Mice

Inflammation, oxidative stress, fibrosis, and ferroptosis play important roles in diabetic nephropathy development. Krüppel-like factor 4 (KLF4) is a transcriptional factor, which regulates multiple cell processes and is involved in diabetic nephropathy. Berberine has various biological activities, including anti-inflammation, antioxidative stress, and antiferroptosis. Berberine has been shown to inhibit diabetic nephropathy, but whether it involves KLF4 and ferroptosis remains unknown. We established a diabetic nephropathy mice model and administered berberine to the mice. The kidney function, renal structure and fibrosis, expression of KLF4 and DNA methylation enzymes, DNA methylation of the KLF4 promoter, mitochondria structure, and expression of oxidative stress and ferroptosis markers were analyzed. Berberine rescued kidney function and renal structure and prevented renal fibrosis in diabetic nephropathy mice. Berberine suppressed the expression of DNMT1 and DNMT2 and upregulated KLF4 expression by preventing KLF4 promoter methylation. Berberine inhibited the expression of oxidative stress and ferroptosis markers, maintained mitochondria structure, and prevented ferroptosis. Berberine ameliorates diabetic nephropathy by inhibiting Klf4 promoter methylation and ferroptosis.

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.

SRS 16-86 promotes diabetic nephropathy recovery by regulating ferroptosis

Diabetic nephropathy (DN) is a common complication of diabetes mellitus (DM), and cell death plays an important role. Ferroptosis is a recently discovered type of iron-dependent cell death and one that is different from other kinds of cell death including apoptosis and necrosis. However, ferroptosis has not been described in the context of DN. This study explored the role of ferroptosis in DN pathophysiology and aimed to confirm the efficacy of the ferroptosis inhibitor SRS 16-86 on DN. Streptozotocin injection was used to establish the DM and DN animal models. To investigate the presence or occurrence of ferroptosis in DN, we assessed the concentrations of iron, reactive oxygen species and specific markers associated with ferroptosis in a rat model of DN. Additionally, we performed haematoxylin-eosin staining, blood biochemistry, urine biochemistry and kidney function analysis to evaluate the efficacy of the ferroptosis inhibitor SRS 16-86 in ameliorating DN. We found that SRS 16-86 could improve the recovery of renal function after DN by upregulating glutathione peroxidase 4, glutathione and system xc -light chain and by downregulating the lipid peroxidation markers and 4-hydroxynonenal. SRS 16-86 treatment could improve renal organization after DN. The inflammatory cytokines interleukin 1β and tumour necrosis factor α and intercellular adhesion molecule 1 were significantly decreased following SRS 16-86 treatment after DN. The results indicate that there is a strong connection between ferroptosis and the pathological mechanism of DN. The efficacy of the ferroptosis inhibitor SRS 16-86 in DN repair supports its use as a new therapeutic treatment for DN.

Ferroptosis: a promising target for fumarate hydratase-deficient tumor therapeutics literature review

Background and Objective

This review aims to investigate the ferroptosis mechanism of fumarate hydratase (FH)-related tumors for the purpose of possible treatment of tumors. Ferroptosis is an iron (Fe)-dependent form of regulated cell death caused by lipid peroxidation on the cell membrane. Studies have implicated FH in tumorigenesis. As mutations in the FH gene alter cellular metabolism and increase tumorigenesis risk, particularly in the kidneys. As most tumor cells require higher amounts of ferrous ions (Fe2+) than normal cells, they are more susceptible to ferroptosis. Recent studies have indicated that ferroptosis is inhibited the pathogenesis and progression of FH-deficient tumors by regulating lipid and iron metabolism, glutathione-glutathione peroxidase 4 (GSH-GPX4), nuclear factor-erythroid 2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) pathways. While the Fe2+ content is significantly lower in FH-deficient tumor cells, than that in normal cells. It is promising to promote ferroptosis by increasing the concentration of Fe2+ in cells to achieve the purpose of tumor treatment.

Methods

In this study, we searched for relevant articles on ferroptosis and FH-deficient tumors using PubMed database.

Key Content and Findings

FH is a tumor suppressor. A number of basic studies have shown that the loss of FH plays an important role in hereditary leiomyomas and tumors such as renal cell carcinoma, ovarian cancer, and other tumors. This type of tumor cells can through induce ferroptosis, inhibit proliferation, migration and invasion of tumor cells, increase the sensitivity of tumor cells to chemotherapy, and reverse the drug resistance through various molecular mechanisms. At present, the research on ferroptosis in FH-related tumors is still in the basic experimental stage.

Conclusions

This article reviews the anti-tumor effects and mechanisms of FH and ferroptosis, in order to further explore the medical value of ferroptosis in FH-related tumor therapy.

tRF3-IleAAT reduced extracellular matrix synthesis in diabetic kidney disease mice by targeting ZNF281 and inhibiting ferroptosis

It is well established that the synthesis of extracellular matrix (ECM) in mesangial cells is a major determinant of diabetic kidney disease (DKD). Elucidating the major players in ECM synthesis may be helpful to provide promising candidates for protecting against DKD progression. tRF3-IleAAT is a tRNA-derived fragment (tRF) produced by nucleases at tRNA-specific sites, which is differentially expressed in the sera of patients with diabetes mellitus and DKD. In this study we investigated the potential roles of tRFs in DKD. Db/db mice at 12 weeks were adapted as a DKD model. The mice displayed marked renal dysfunction accompanied by significantly reduced expression of tRF3-IleAAT and increased ferroptosis and ECM synthesis in the kidney tissues. The reduced expression of tRF3-IleAAT was also observed in high glucose-treated mouse glomerular mesangial cells. We administered ferrostatin-1 (1 mg/kg, once every two days, i.p.) to the mice from the age of 12 weeks for 8 weeks, and found that inhibition of the onset of ferroptosis significantly improved renal function, attenuated renal fibrosis and reduced collagen deposition. Overexpression of tRF3-IleAAT by a single injection of AAV carrying tRF3-IleAAT via caudal vein significantly inhibited ferroptosis and ECM synthesis in DKD model mice. Furthermore, we found that the expression of zinc finger protein 281 (ZNF281), a downstream target gene of tRF3-IleAAT, was significantly elevated in DKD models but negatively regulated by tRF3-IleAAT. In high glucose-treated mesangial cells, knockdown of ZNF281 exerted an inhibitory effect on ferroptosis and ECM synthesis. We demonstrated the targeted binding of tRF3-IleAAT to the 3'UTR of ZNF281. In conclusion, tRF3-IleAAT inhibits ferroptosis by targeting ZNF281, resulting in the mitigation of ECM synthesis in DKD models, suggesting that tRF3-IleAAT may be an attractive therapeutic target for DKD.

Olive Flounder By-Product Prozyme2000P Hydrolysate Ameliorates Age-Related Kidney Decline by Inhibiting Ferroptosis

This study explores olive flounder by-product Prozyme2000P (OFBP) hydrolysate as a potential treatment for age-related kidney decline. Ferroptosis, a form of cell death linked to iron overload and oxidative stress, is increasingly implicated in aging kidneys. We investigated whether OFBP could inhibit ferroptosis and improve kidney health. Using TCMK-1 cells, we found that OFBP treatment protected cells from ferroptosis induced by sodium iodate (SI). OFBP also preserved the mitochondria health and influenced molecules involved in ferroptosis regulation. In aging mice, oral administration of OFBP significantly improved kidney health markers. Microscopic examination revealed reduced thickening and scarring in the kidney's filtering units, a hallmark of aging. These findings suggest that OFBP hydrolysate may be a promising therapeutic candidate for age-related kidney decline. By inhibiting ferroptosis, OFBP treatment appears to improve both cellular and structural markers of kidney health. Further research is needed to understand how OFBP works fully and test its effectiveness in more complex models.

GLP-1 receptor agonist attenuates tubular cell ferroptosis in diabetes via enhancing AMPK-fatty acid metabolism pathway through macropinocytosis

Kidney tubules are mostly responsible for pathogenesis of diabetic kidney disease. Actively reabsorption of iron, high rate of lipid metabolism and exposure to concentrated redox-active compounds constructed the three main pillars of ferroptosis in tubular cells. However, limited evidence has indicated that ferroptosis is indispensable for diabetic tubular injury. Glucagon-like peptide-1 receptor agonist (GLP-1RA) processed strong benefits on kidney outcomes in people with diabetes. Moreover, GLP-1RA may have additive effects by improving dysmetabolism besides glucose control and weight loss. Therefore, the present study aimed at exploring the benefits of exendin-4, a high affinity GLP-1RA on kidney tubular dysregulation in diabetes and the possible mechanisms involved, with focus on ferroptosis and adenosine 5'-monophosphate-activated protein kinase (AMPK)-mitochondrial lipid metabolism pathway. Our data revealed that exendin-4 treatment markedly improved kidney structure and function by reducing iron overload, oxidative stress, and ACSL4-driven lipid peroxidation taken place in diabetic kidney tubules, along with reduced GPX4 expression and GSH content. AMPK signaling was identified as the downstream target of exendin-4, and enhancement of AMPK triggered the transmit of its downstream signal to activate fatty acid oxidation in mitochondria and suppress lipid synthesis and glycolysis, and ultimately alleviated toxic lipid accumulation and ferroptosis. Further study suggested that exendin-4 was taken up by tubular cells via macropinocytosis. The protective effect of exendin-4 on tubular ferroptosis was abolished by macropinocytosis blockade. Taken together, present work demonstrated the beneficial effects of GLP-1RA treatment on kidney tubular protection in diabetes by suppressing ferroptosis through enhancing AMPK-fatty acid metabolic signaling via macropinocytosis.

Copper homeostasis in chronic kidney disease and its crosstalk with ferroptosis

Chronic kidney disease (CKD) has become a global public health problem with high morbidity and mortality. Renal fibrosis can lead to end-stage renal disease (ESRD). However, there is still no effective treatment to prevent or delay the progression of CKD into ESRD. Therefore, exploring the pathogenesis of CKD is essential for preventing and treating CKD. There are a variety of trace elements in the human body that interact with each other within a complex regulatory network. Iron and copper are both vital trace elements in the body. They are critical for maintaining bodily functions, and the dysregulation of their metabolism can cause many diseases, including kidney disease. Ferroptosis is a new form of cell death characterized by iron accumulation and lipid peroxidation. Studies have shown that ferroptosis is closely related to kidney disease. However, the role of abnormal copper metabolism in kidney disease and its relationship with ferroptosis remains unclear. Here, our current knowledge regarding copper metabolism, its regulatory mechanism, and the role of abnormal copper metabolism in kidney diseases is summarized. In addition, we discuss the relationship between abnormal copper metabolism and ferroptosis to explore the possible pathogenesis and provide a potential therapeutic target for CKD.

Induction of ferroptosis by natural phenols: A promising strategy for cancer therapy

In recent years, heightened interest surrounds the exploration of natural phenols as potential agents for cancer therapy, specifically by inducing ferroptosis, a unique form of regulated cell death characterized by iron-dependent lipid peroxidation. This review delves into the roles of key natural phenols, flavonoids, phenolic acids, curcumin, and stilbenes, in modulating ferroptosis and their underlying mechanisms. Emphasizing the significance of amino acid, lipid, and iron metabolism, the study elucidates the diverse pathways through which these phenols regulate ferroptosis. Notably, curcumin, a well-known polyphenol, exhibits multifaceted interactions with cellular components involved in ferroptosis regulation, providing a distinctive therapeutic avenue. Stilbenes, another phenolic class, demonstrate promising potential in influencing lipid metabolism and iron-dependent processes, contributing to ferroptotic cell death. Understanding the intricate interplay between these natural phenols and ferroptosis not only illuminates complex cellular regulatory networks but also unveils potential avenues for novel cancer therapies. Exploring these compounds as inducers of ferroptosis presents a promising strategy for targeted cancer treatment, capitalizing on the delicate balance between cellular metabolism and regulated cell death mechanisms. This article synthesizes current knowledge, aiming to stimulate further research into the therapeutic potential of natural phenols in the context of ferroptosis-mediated cancer therapy.

Natural product-derived ferroptosis mediators

It has been 11 years since ferroptosis, a new mode of programmed cell death, was first proposed. Natural products are an important source of drug discovery. In the past five years, natural product-derived ferroptosis regulators have been discovered in an endless stream. Herein, 178 natural products discovered so far to trigger or resist ferroptosis are classified into 6 structural classes based on skeleton type, and the mechanisms of action that have been reported are elaborated upon. If pharmacodynamic data are sufficient, the structure and bioactivity relationship is also presented. This review will provide medicinal chemists with some effective ferroptosis regulators, which will promote the research of natural product-based treatment of ferroptosis-related diseases in the future.

Ferroptosis: A new view on the prevention and treatment of diabetic kidney disease with traditional Chinese medicine

Diabetic kidney disease is one of the complications of diabetes mellitus, which can eventually progress to end-stage kidney disease. The increasing prevalence of diabetic kidney disease has brought huge economic burden to society and seriously jeopardized public health. Ferroptosis is an iron-dependent, non-apoptosis-regulated form of cell death. The regulation of ferroptosis involves different molecular mechanisms and multiple cellular metabolic pathways. In recent years, ferroptosis has been proved to be closely related to the occurrence and development of diabetic kidney disease, and can interact with pathological changes such as fibrosis, inflammation, oxidative stress, and disorders of glucose and lipid metabolism, destroying the structure, form and function of the inherent cells of the kidney, and promoting the progression of the disease. Traditional Chinese medicine has a long history of treating diabetic kidney disease with remarkable curative effect. Current scholars have shown that the oral administration of traditional Chinese medicine and the external treatment of Chinese medicine can regulate GPX4, Nrf2, ACSL4, PTGS2, TFR1 and other key signaling molecules, curb ferroptosis, and prevent the progressive deterioration of diabetic kidney disease. In this paper, the mechanism of ferroptosis and diabetic kidney disease and the prevention and treatment of traditional Chinese medicine are analyzed and summarized, in order to provide new ideas and new plans for the treatment of diabetic kidney disease.

Brevilin A attenuates cartilage destruction in osteoarthritis mouse model by inhibiting inflammation and ferroptosis via SIRT1/Nrf2/GPX4 signaling pathway

Osteoarthritis (OA) is a serious orthopedic disease that affects people's quality of life. Although there are many treatment methods, the treatment effect is still not good. Brevilin A is a bioactive compound isolated from the medicinal herbCentipeda minima. The potential efficacy of brevilin A on OA was explored in this study. Mouse chondrocytes were isolated and stimulated by IL-1β and mouse OA model was induced by destabilization of the medial meniscus (DMM). The results demonstrated that brevilin A markedly inhibited IL-1β-induced MMP1 and MMP3 production. IL-1β-induced PGE2, NO, MDA, and iron production were alleviated by brevilin A. The production of GSH and the expression of SIRT1, Nrf2, HO-1, GPX4, and Ferritin were increased by brevilin A. Furthermore, the inhibition of brevilin A on IL-1β-induced inflammation and ferroptosis were prevented by SIRT1 inhibitor. In vivo, the results showed brevilin A markedly attenuated OA progression in DMM-induced mouse OA model. Also, brevilin A could alleviate MMP1, MMP3, iNOS, and COX2 expression in OA mice. In conclusion, brevilin A protected mice against OA via suppressing inflammatory response and ferroptosis by regulating SIRT1/Nrf2/GPX4 signaling.

Saikosaponin A alleviates Staphylococcus aureus-induced mastitis in mice by inhibiting ferroptosis via SIRT1/Nrf2 pathway

Mastitis is a common and serious bacterial infection of the mammary gland. Saikosaponin A (SSA) is a triterpenoid saponin isolated from Bupleurum falcatum that has the ability to treat various diseases. However, little is known about the role of SSA in achieving mastitis remission. Here, we found that SSA alleviated Staphylococcus aureus (S. aureus)-induced mastitis by attenuating inflammation and maintaining blood-milk barrier integrity. Furthermore, S. aureus activated nuclear factor kappa B (NF-κB) pathway by upregulated p-p65 and p-IκB. S. aureus also induced ferroptosis in mammary gland in mice, mainly characterized by excessive iron accumulation, mitochondrial morphological changes and impaired antioxidant production. However, S. aureus-induced NF-κB activation and ferroptosis were prevented by SSA. Moreover, SAA could upregulate the expression of SIRT1, Nrf2, HO-1 and GPX4. And the inhibitory effects of SAA on inflammation and ferroptosis were reversed by SIRT1 inhibitor EX-527. In conclusion, SAA protected S. aureus-induced mastitis through suppressing inflammation and ferroptosis by activating SIRT1/Nrf2 pathway.

Versatile function of AMPK signaling in osteosarcoma: An old player with new emerging carcinogenic functions

AMP-activated protein kinase (AMPK) signaling has a versatile role in Osteosarcoma (OS), an aggressive bone malignancy with a poor prognosis, particularly in cases that have metastasized or recurred. This review explores the regulatory mechanisms, functional roles, and therapeutic applications of AMPK signaling in OS. It focuses on the molecular activation of AMPK and its interactions with cellular processes like proliferation, apoptosis, and metabolism. The uncertain role of AMPK in cancer is also discussed, highlighting its potential as both a tumor suppressor and a contributor to carcinogenesis. The therapeutic potential of targeting AMPK signaling in OS treatment is examined, including direct and indirect activators like metformin, A-769662, resveratrol, and salicylate. Further research is needed to determine dosing, toxicities, and molecular mechanisms responsible for the anti-osteosarcoma effects of these compounds. This review underscores the complex involvement of AMPK signaling in OS and emphasizes the need for a comprehensive understanding of its molecular mechanisms. By elucidating the role of AMPK in OS, the aim is to pave the way for innovative therapeutic approaches that target this pathway, ultimately improving the prognosis and quality of life for OS patients.

Targeting ferroptosis in renal cell carcinoma: Potential mechanisms and novel therapeutics

Renal cell carcinoma (RCC) is an increasingly prevalent urologic malignancy that impacts human health worldwide. Surgery is an effective strategy for early RCC treatment, but advanced RCC is resistant to chemotherapy, thus development of other potential therapeutic strategies is urgent. Ferroptosis is a newly defined form of programmed cell death characterized by accumulation of iron-dependent lipid peroxides and plays a crucial role in the tumor progression and drug resistance. Recent studies have shown that ferroptosis participates in RCC progression and chemoresistance. Therefore, identifying the potential role of ferroptosis in RCC could develop novel therapeutic targets and clinical markers for this disease. This review concisely summarizes the regulatory role of iron, amino acid, and lipid metabolism in ferroptosis, as well as discusses the relationship between ferroptosis and RCC, and details the role of ferroptosis in tumor progression, which indicates that various ferroptosis regulators are dysregulated in RCC and exert paradoxical effects, either tumor-suppressive or oncogenic. These ferroptosis-related regulators are expected to be used as clinical markers for RCC prognosis. Thus, targeting these regulators to trigger ferroptosis may be the key to the development of potential therapeutic strategies for this disease.

Melanin precursors mediated adaption to temperature changes in fungus and animal via inhibition of lipid-mediated ferroptosis

The discovery of biological activities of natural products plays a vital part in drug development. The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely cryptic. A thermophilic fungus under cold stress turned black and accumulated a polyketide metabolite 1 and lipid mass. Deficiency in 1 caused melanin loss and accumulated extra lipid mass, unexpectedly leading to seriously damaged mitochondria diagnostic for ferroptosis. Further analysis revealed that lipid mass induced by cold stress intensively increased ferroptosis risk and 1 functioned as cell wall reinforcer against mass lipid accumulation and as reactive oxygen species scavenger against lipid peroxidation. We also found that melanin in mice lowered lipid level but enhanced animal resistance to cold stress. Treatment with melanin precursors significantly increased mouse cell survival rate under cold stress. Our results unveiled a metabolite-lipid-ferroptosis-cold relationship, which provided mechanistic insights into the functions of most common metabolites and into diseases related to cold stress. These findings opened a perspective for developing anti-cold and anti-ferroptosis therapeutics and agents.

Ferroptosis in diabetic nephropathy: Mechanisms and therapeutic implications

Diabetic Nephropathy (DN), the most common complication in diabetes mellitus, has been affecting the lives of people diabetic for a long time. Numerous studies have demonstrated the unbreakable connection between ferroptosis and kidney cell damage. Ferroptosis is a type of iron-dependent, non-apoptotic, regulated cell death, characterized by the buildup of intracellular lipid peroxides to lethal levels. Although the role of programmed cell deaths like apoptosis, autophagy, and necroptosis in the pathogenesis of DN has been demonstrated, the implication of ferroptosis in DN was least interrogated. Hence, the main aim of this review was to discuss the current understanding of ferroptosis focusing on its potential mechanisms, its involvement in DN, and emerging therapeutic opportunities.

Novel Insight into Ferroptosis in Kidney Diseases

BACKGROUND

Various kidney diseases such as acute kidney injury, chronic kidney disease, polycystic kidney disease, renal cancer, and kidney stones, are an important part of the global burden, bringing a huge economic burden to people around the world. Ferroptosis is a type of nonapoptotic iron-dependent cell death caused by the excess of iron-dependent lipid peroxides and accompanied by abnormal iron metabolism and oxidative stress. Over the past few decades, several studies have shown that ferroptosis is associated with many types of kidney diseases. Studying the mechanism of ferroptosis and related agonists and inhibitors may provide new ideas and directions for the treatment of various kidney diseases.

SUMMARY

In this review, we discuss the differences between ferroptosis and other types of cell death such as apoptosis, necroptosis, pyroptosis, cuprotosis, pathophysiological features of the kidney, and ferroptosis-induced kidney injury. We also provide an overview of the molecular mechanisms involved in ferroptosis and events that lead to ferroptosis. Furthermore, we summarize the possible clinical applications of this mechanism among various kidney diseases.

KEY MESSAGE

The current research suggests that future therapeutic efforts to treat kidney ailments would benefit from a focus on ferroptosis.

Zooming in and out of ferroptosis in human disease

Ferroptosis is defined as an iron-dependent regulated form of cell death driven by lipid peroxidation. In the past decade, it has been implicated in the pathogenesis of various diseases that together involve almost every organ of the body, including various cancers, neurodegenerative diseases, cardiovascular diseases, lung diseases, liver diseases, kidney diseases, endocrine metabolic diseases, iron-overload-related diseases, orthopedic diseases and autoimmune diseases. Understanding the underlying molecular mechanisms of ferroptosis and its regulatory pathways could provide additional strategies for the management of these disease conditions. Indeed, there are an expanding number of studies suggesting that ferroptosis serves as a bona-fide target for the prevention and treatment of these diseases in relevant pre-clinical models. In this review, we summarize the progress in the research into ferroptosis and its regulatory mechanisms in human disease, while providing evidence in support of ferroptosis as a target for the treatment of these diseases. We also discuss our perspectives on the future directions in the targeting of ferroptosis in human disease.

Total Flavonoids of Rhizoma Drynariae Mitigates Aflatoxin B1-Induced Liver Toxicity in Chickens via Microbiota-Gut-Liver Axis Interaction Mechanisms

Aflatoxin B1 (AFB1) is a common mycotoxin that widely occurs in feed and has severe hepatotoxic effects both in humans and animals. Total flavonoids of Rhizoma Drynaria (TFRD), a traditional Chinese medicinal herb, have multiple biological activities and potential hepatoprotective activity. This study investigated the protective effects and potential mechanisms of TFRD against AFB1-induced liver injury. The results revealed that supplementation with TFRD markedly lessened broiler intestinal permeability by increasing the expression of intestinal tight junction proteins, as well as correcting the changes in gut microbiota and liver damage induced by AFB1. Metabolomics analysis revealed that the alterations in plasma metabolites, especially taurolithocholic acid, were significantly improved by TFRD treatment in AFB1-exposed chickens. In addition, these metabolites were closely associated with [Ruminococcus], ACC, and GPX1, indicating that AFB1 may cause liver injury by inducing bile acid metabolism involving the microbiota–gut–liver axis. We further found that TFRD treatment markedly suppressed oxidative stress and hepatic lipid deposition, increased plasma glutathione (GSH) concentrations, and reversed hepatic ferroptosis gene expression. Collectively, these findings indicate that ferroptosis might contribute to the hepatotoxicity of AFB1-exposed chickens through the microbiota–gut–liver axis interaction mechanisms; furthermore, TFRD was confirmed as an herbal extract that could potentially antagonize mycotoxins detrimental effects.

Landscape of Well-Coordinated Fracture Healing in a Mouse Model Using Molecular and Cellular Analysis

The success of fracture healing relies on overlapping but coordinated cellular and molecular events. Characterizing an outline of differential gene regulation throughout successful healing is essential for identifying crucial phase-specific markers and may serve as the basis for engineering these in challenging healing situations. This study analyzed the healing progression of a standard closed femoral fracture model in C57BL/6N (age = 8 weeks) wild-type male mice. The fracture callus was assessed across various days post fracture (D = days 0, 3, 7, 10, 14, 21, and 28) by microarray, with D0 serving as a control. Histological analyses were carried out on samples from D7 until D28 to support the molecular findings. Microarray analysis revealed a differential regulation of immune response, angiogenesis, ossification, extracellular matrix regulation, mitochondrial and ribosomal genes during healing. In-depth analysis showed differential regulation of mitochondrial and ribosomal genes during the initial phase of healing. Furthermore, the differential gene expression showed an essential role of Serpin Family F Member 1 over the well-known Vascular Endothelial Growth Factor in angiogenesis, especially during the inflammatory phase. The significant upregulation of matrix metalloproteinase 13 and bone sialoprotein from D3 until D21 asserts their importance in bone mineralization. The study also shows type I collagen around osteocytes located in the ossified region at the periosteal surface during the first week of healing. Histological analysis of matrix extracellular phosphoglycoprotein and extracellular signal-regulated kinase stressed their roles in bone homeostasis and the physiological bone-healing process. This study reveals previously unknown and novel candidates, that could serve as a target for specific time points in healing and to remedy cases of impaired healing.

Mechanism of ferroptosis in traditional chinese medicine for clinical treatment: A review

Ferroptosis is an iron-dependent regulation of cell death driven by lipid peroxidation, which is intracellularly dependent on iron and independent of other metals, and morphologically, biochemically, and genetically distinct from apoptosis, necrosis, and autophagy. Ferroptosis is closely related to physiological and pathological processes, such as development, aging, and immunity, and it plays an important role in a variety of diseases. In many departments, traditional Chinese medicine plays an increasingly important role in their clinical treatment. In recent years, an increasing number of studies have been conducted on the mechanism of ferroptosis in traditional Chinese medicine. However, the role of ferroptosis in the clinical treatment of traditional Chinese medicine requires further exploration. This article mainly introduces the application of ferroptosis in studies of the mechanism of traditional Chinese medicine to help clinicians understand the current status of traditional Chinese medicine therapy for the treatment of ferroptosis-related diseases.

Identifying the molecular mechanisms of sepsis-associated acute kidney injury and predicting potential drugs

Objective: To provide insights into the diagnosis and therapy of SA-AKI via ferroptosis genes. Methods: Based on three datasets (GSE57065, GSE30718, and GSE53771), we used weighted co-expression network analysis to identify the key regulators of SA-AKI, its potential biological functions, and constructed miRNA‒mRNA complex regulatory relationships. We also performed machine learning and in vitro cell experiments to identify ferroptosis genes that are significantly related to SA-AKI in the two datasets. The CIBERSORT algorithm evaluates the degree of infiltration of 22 types of immune cell. We compared the correlation between ferroptosis and immune cells by Pearson's correlation analysis and verified the key genes related to the immune response to reveal potential diagnostic markers. Finally, we predicted the effects of drugs and the potential therapeutic targets for septic kidney injury by pRRophetic. Results: We found 264 coDEGs involving 1800 miRNA molecules that corresponded to 210 coDEGs. The miRNA‒mRNA ceRNA interaction network was constructed to obtain the top-10 hub nodes. We obtained the top-20 ferroptosis genes, 11 of which were in the intersection. We also identified a relationship between ferroptosis genes and the immune cells in the AKI dataset, which showed that neutrophils were activated and that regulatory T cells were surpassed. Finally, we identified EHT1864 and salubrinal as potential therapeutic agents. Conclusion: This study demonstrated the roles of miR-650 and miR-296-3p genes in SA-AKI. Furthermore, we identified OLFM4, CLU, RRM2, SLC2A3, CCL5, ADAMTS1, and EPHX2 as potential biomarkers. The irregular immune response mediated by neutrophils and Treg cells is involved in the development of AKI and shows a correlation with ferroptosis genes. EHT 1864 and salubrinal have potential as drug candidates in patients with septic acute kidney injury.

Identification of ferroptosis‑associated genes in chronic kidney disease

Ferroptosis serves a pivotal role in developing chronic kidney disease (CKD). The present study aimed to detect and confirm the relevance of potential ferroptosis-related genes in CKD using bioinformatics and experimentation strategies. The original GSE15072 mRNA expression dataset was retrieved from the Gene Expression Omnibus database. Subsequently, the potential differentially expressed genes associated with ferroptosis of CKD were screened using R software. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analyses, correlation analysis and protein-protein interactions (PPI) were performed for differentially expressed ferroptosis-associated genes (DFGs). Lastly, the expression levels of the top nine DFGs were measured in the kidney tissue of Adriamycin-induced CKD rats and healthy controls via reverse transcription-quantitative (RT-q)PCR analysis. Overall, 49 DFGs among 21 patients with CKD and nine healthy controls were identified. GO and KEGG enrichment analyses demonstrated that these DFGs were primarily involved in 'ferroptosis' and 'mitophagy'. PPI findings indicated that these ferroptosis-associated genes interacted with one another. RT-qPCR of CKD tissue from the rat model revealed that STAT3, MAPK14, heat shock protein (HSP)A5, MTOR and solute carrier family 2 member 1 (SLC2A1) mRNA levels in CKD were upregulated. Overall, 49 potential ferroptosis-associated genes of CKD were identified via bioinformatics analyses. STAT3, MAPK14, HSPA5, MTOR and SLC2A1 may influence CKD onset by regulating ferroptosis. The present results add to the existing body of knowledge about CKD and may be useful in the treatment of CKD.

Ferroptosis and renal fibrosis: A new target for the future (Review)

Ferroptosis is a type of non-apoptotic controlled cell death triggered by oxidative stress and iron-dependent lipid peroxidation. Ferroptosis is regulated by signalling pathways that are associated with metabolism, including glutathione peroxidase 4 dysfunction, the cystine/glutamate antiporter system, lipid peroxidation and inadequate iron metabolism. Ferroptosis is associated with renal fibrosis; however, further research is required to understand the specific molecular mechanisms involved. The present review aimed to discuss the known molecular mechanisms of ferroptosis and outline the biological reactions that occur during renal fibrosis that may be associated with ferroptosis. Further investigation into the association between ferroptosis and renal fibrosis may lead to the development of novel treatment methods.

Ginsenoside Rg1 ameliorates sepsis-induced acute kidney injury by inhibiting ferroptosis in renal tubular epithelial cells

Acute kidney injury (AKI) represents a prevailing complication of sepsis, and its onset involves ferroptosis. Ginsenoside Rg1 exerts a positive effect on kidney diseases. This study explored the action of ginsenoside Rg1 in sepsis-induced AKI (SI-AKI) by regulating ferroptosis in renal tubular epithelial cells (TECs). Sepsis rat models were established using cecal ligation and puncture (CLP) and cell models were established by treating human renal TECs (HK-2) with LPS to induce ferroptosis. Serum creatinine (SCr) and blood urea nitrogen (BUN) and urine KIM1 contents in rats were determined by ELISA kits. Kidney tissues were subjected to immunohistochemical and H&E stainings. Iron concentration, malondialdehyde (MDA), glutathione (GSH), and ferroptosis-related protein (ferritin light chain [FTL], ferritin heavy chain [FTH], GSH peroxidase 4 [GPX4], and Ferroptosis suppressor protein 1 [FSP1]) levels in kidney tissues and HK-2 cells were measured using ELISA kits and Western blotting. HK-2 cell viability was detected by cell counting kit-8, and cell death was observed via propidium iodide staining. Reactive oxygen species accumulation in cells was detected using C11 BODIPY 581/591 as a molecular probe. In CLP rats, ginsenoside Rg1 reduced SCr, BUN, KIM1, and NGAL levels, thus palliating SI-AKI. Additionally, ginsenoside Rg1 decreased iron content, FTL, FTH, and MDA levels, and elevated GPX4, FSP1, and GSH levels, thereby inhibiting lipid peroxidation and ferroptosis. Moreover, FSP1 knockdown annulled the inhibition of ginsenoside Rg1 on ferroptosis. In vitro experiments, ginsenoside Rg1 raised HK-2 cell viability and lowered iron accumulation and lipid peroxidation during ferroptosis, and its antiferroptosis activity was dependent on FSP1. Ginsenoside Rg1 alleviates SI-AKI, possibly resulting from inhibition of ferroptosis in renal TECs through FSP1.

Establishment and validation of a polygene prognostic model for clear cell renal cell carcinoma

Purpose: To establish an effective prognostic model for patients with clear cell renal cell carcinoma (ccRCC). Methods: We identified four hub differentially expressed genes (DEGs) in Gene Expression Omnibus (GEO) database and verified them in the Cancer Gene Atlas (TCGA), STRING, UALCAN, TIMER, and Gene Expression Profiling Interactive Analysis (GEPIA) databases. We then used TCGA and International Cancer Genome Consortium (ICGC) to identify tumor pathway molecules highly correlated with hub DEGs. And by further LASSO and Cox regression analysis, we successfully identified five genes as prognostic factors. Results: We successfully identified a risk prediction model consisting of five genes: IGF2BP3, CDKN1A, GSDMB, FABP5, RBMX. We next distributed patients into low-risk and high-risk groups using the median as a cutoff. The low-risk group obviously had better survival than those in the predicted high-risk group. The results showed discrepancies in tumor-associated immune cell infiltration between risk groups. We also combined the risk model with clinical variables to create a nomogram. Conclusion: Our model has a satisfactory predictive effect on the prognosis of ccRCC patients and may provide new ideas for future immune therapy.

Molecular Mechanisms of Cellular Injury and Role of Toxic Heavy Metals in Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive disease that affects millions of adults every year. Major risk factors include diabetes, hypertension, and obesity, which affect millions of adults worldwide. CKD is characterized by cellular injury followed by permanent loss of functional nephrons. As injured cells die and nephrons become sclerotic, remaining healthy nephrons attempt to compensate by undergoing various structural, molecular, and functional changes. While these changes are designed to maintain appropriate renal function, they may lead to additional cellular injury and progression of disease. As CKD progresses and filtration decreases, the ability to eliminate metabolic wastes and environmental toxicants declines. The inability to eliminate environmental toxicants such as arsenic, cadmium, and mercury may contribute to cellular injury and enhance the progression of CKD. The present review describes major molecular alterations that contribute to the pathogenesis of CKD and the effects of arsenic, cadmium, and mercury on the progression of CKD.

Unraveling the interplay between iron homeostasis, ferroptosis and extramedullary hematopoiesis

Iron participates in myriad processes necessary to sustain life. During the past decades, great efforts have been made to understand iron regulation and function in health and disease. Indeed, iron is associated with both physiological (e.g., immune cell biology and function and hematopoiesis) and pathological (e.g., inflammatory and infectious diseases, ferroptosis and ferritinophagy) processes, yet few studies have addressed the potential functional link between iron, the aforementioned processes and extramedullary hematopoiesis, despite the obvious benefits that this could bring to clinical practice. Further investigation in this direction will shape the future development of individualized treatments for iron-linked diseases and chronic inflammatory disorders, including extramedullary hematopoiesis, metabolic syndrome, cardiovascular diseases and cancer.

Ferrostatin‑1 alleviates oxalate‑induced renal tubular epithelial cell injury, fibrosis and calcium oxalate stone formation by inhibiting ferroptosis

The present study aimed to evaluate the role and mechanism of ferrostatin-1 (Fer-1) in oxalate (Ox)-induced renal tubular epithelial cell injury, fibrosis, and calcium oxalate (CaOx) stone formation. A CaOx model in mice kidneys was established via intraperitoneal injection of 80 mg/kg glyoxylic acid for 14 days. The mice were randomly divided into three groups (n=6), namely, the control (Con), the CaOx group, and the CaOx + Fer-1 group. Cultured human renal tubular epithelial cells (HK-2 cells) were randomly divided into three groups (n=3), namely, the control (Con), the Ox group, and the Ox + Fer-1 group. The levels of heme oxygenase 1 (HO-1), superoxide dismutase 2 (SOD2), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11) were assessed by immunofluorescence and western blot analysis. Renal tubular injury and apoptosis were evaluated by H&E and TUNEL staining. Kidney interstitial fibrosis was evaluated by Masson and Sirius red staining, and the levels of E-cadherin, vimentin and α-SMA were detected by immunofluorescence or western blot analysis. Mitochondrial structure was observed using a transmission electron microscope. The levels of reactive oxygen species (ROS) were determined by flow cytometry and CaOx stone formation was evaluated by von Kossa staining. The results revealed that in comparison with the Con group, mitochondrial injury under glyoxylic acid treatment was observed by TEM. The expression of GPX4 and SLC7A11 in the CaOx and Ox groups was downregulated (P<0.05), whereas the expression of HO-1 and SOD2 was upregulated (P<0.05). Renal tissue damage, apoptosis of renal tubular epithelial cells, and interstitial fibrosis were increased in the CaOx and Ox groups (P<0.05). In comparison with the CaOx or Ox group, the expression of GPX4 and SLC7A11 in the CaOx + Fer-1 or Ox + Fer-1 group was upregulated (P<0.05), whereas that of HO-1 and SOD2 was downregulated (P<0.05). Renal tissue damage, apoptosis of renal tubular epithelial cells and interstitial fibrosis were decreased following Fer-1 treatment (P<0.05). The ROS level was also decreased following Fer-1 treatment. Moreover, CaOx stone formation was decreased in the CaOx + Fer-1 group (P<0.05). In conclusion, Fer-1 alleviated Ox-induced renal tubular epithelial cell injury, fibrosis, and CaOx stone formation by inhibiting ferroptosis.

Molecular Mechanisms of Epigenetic Regulation, Inflammation, and Cell Death in ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder, which is caused by mutations in the PKD1 and PKD2 genes, characterizing by progressive growth of multiple cysts in the kidneys, eventually leading to end-stage kidney disease (ESKD) and requiring renal replacement therapy. In addition, studies indicate that disease progression is as a result of a combination of factors. Understanding the molecular mechanisms, therefore, should facilitate the development of precise therapeutic strategies for ADPKD treatment. The roles of epigenetic modulation, interstitial inflammation, and regulated cell death have recently become the focuses in ADPKD. Different epigenetic regulators, and the presence of inflammatory markers detectable even before cyst growth, have been linked to cyst progression. Moreover, the infiltration of inflammatory cells, such as macrophages and T cells, have been associated with cyst growth and deteriorating renal function in humans and PKD animal models. There is evidence supporting a direct role of the PKD gene mutations to the regulation of epigenetic mechanisms and inflammatory response in ADPKD. In addition, the role of regulated cell death, including apoptosis, autophagy and ferroptosis, have been investigated in ADPKD. However, there is no consensus whether cell death promotes or delays cyst growth in ADPKD. It is therefore necessary to develop an interactive picture between PKD gene mutations, the epigenome, inflammation, and cell death to understand why inherited PKD gene mutations in patients may result in the dysregulation of these processes that increase the progression of renal cyst formation.

Glabridin, a bioactive component of licorice, ameliorates diabetic nephropathy by regulating ferroptosis and the VEGF/Akt/ERK pathways

Background

Glabridin (Glab) is a bioactive component of licorice that can ameliorate diabetes, but its role in diabetic nephropathy (DN) has seldom been reported. Herein, we explored the effect and underlying mechanism of Glab on DN.

Methods

The bioactive component-target network of licorice against DN was by a network pharmacology approach. The protective effect of Glab on the kidney was investigated by a high-fat diet with streptozotocin induced-diabetic rat model. High glucose-induced NRK-52E cells were used for in vitro studies. The effects of Glab on ferroptosis and VEGF/Akt/ERK pathways in DN were investigated in vivo and in vitro using qRT-PCR, WB, and IHC experiments.

Results

Bioinformatics analysis constructed a network comprising of 10 bioactive components of licorice and 40 targets for DN. 13 matching targets of Glab were mainly involved in the VEGF signaling pathway. Glab treatment ameliorated general states and reduced FBG, HOMA-β, and HOMA-insulin index of diabetic rats. The renal pathological changes and the impaired renal function (the increased levels of Scr, BUN, UREA, KIM-1, NGAL, and TIMP-1) were also improved by Glab. Moreover, Glab repressed ferroptosis by increasing SOD and GSH activity, and GPX4, SLC7A11, and SLC3A2 expression, and decreasing MDA and iron concentrations, and TFR1 expression, in vivo and in vitro. Mechanically, Glab significantly suppressed VEGF, p-AKT, p-ERK1/2 expression in both diabetic rats and HG-induced NRK-52E cells.

Conclusions

This study revealed protective effects of Glab on the kidney of diabetic rats, which might exert by suppressing ferroptosis and the VEGF/Akt/ERK pathway.

Vitamin E (Alpha-Tocopherol) Metabolism and Nutrition in Chronic Kidney Disease

Vitamin E (alpha-tocopherol) is an essential micronutrient and fat-soluble antioxidant with proposed role in protecting tissues from uncontrolled lipid peroxidation. This vitamin has also important protein function and gene modulation effects. The metabolism of vitamin E depends on hepatic binding proteins that selectively retain food alpha-tocopherol for incorporation into nascent VLDL and tissue distribution together with esterified cholesterol and triglycerides. Chronic kidney disease (CKD) is a condition of oxidative stress and increased lipid peroxidation, that are associated with alterations of alpha-tocopherol metabolism and function. Specific changes have been reported for the levels of its enzymatic metabolites, including both short-chain and long-chain metabolites, the latter being endowed with regulatory functions on enzymatic and gene expression processes important for the metabolism of lipids and xenobiotics detoxification, as well as for the control of immune and inflammatory processes. Vitamin E therapy has been investigated in CKD using both oral vitamin E protocols and vitamin E-coated hemodialyzers, showing promising results in the secondary prevention of cardiovascular disease, as well as of immune and hematological complications. These therapeutic approaches are reviewed in the present article, together with a narrative excursus on the main findings indicating CKD as a condition of relative deficiency and impaired metabolism of vitamin E.

IFNγ enhances ferroptosis by increasing JAK‑STAT pathway activation to suppress SLCA711 expression in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare type of tumor with a poor prognosis. Ferroptosis is a relatively novel form of programmed cell death driven by iron-dependent lipid peroxidation accumulation. Recent evidence suggests that IFNγ facilitates erastin-induced ferroptosis, which contributed to anticancer therapy in various types of cancer. However, it has remained elusive whether the regulation of IFNγ on ferroptosis has a positive role in the treatment of ACC. Thus, the aim of the present study was to explore the effects of IFNγ on erastin-induced ferroptosis in the ACC cell line NCI-H295R and investigate the underlying mechanisms. Cell viability was assessed using a Cell Counting Kit-8 assay, an ethynyldioxyuridine proliferation assay and Live/Dead staining. The levels of iron, reactive oxygen species, lipid peroxidation and mitochondrial damage were also assessed. Western blot and reverse transcription-quantitative PCR analyses were used to determine the underlying molecular mechanisms involved in the erastin-induced ferroptosis of NCI-H295R cells. The results suggested that IFNγ promoted erastin-induced ferroptotic cell death. Furthermore, IFNγ enhanced erastin-induced ferroptosis, as evidenced by the accumulation of iron, as well as the increase in lipid peroxidation and promotion of mitochondrial damage. Further analysis suggested that IFNγ enhanced ferroptosis by suppressing the expression of solute carrier family 7 member 11, an important negative regulator of ferroptosis, and this was achieved via activation of the JAK/STAT pathway in NCI-H295R cells. The present study provided experimental evidence on the activity and mechanism of ferroptosis enhanced by IFNγ in ACC and may give critical insight into the immunotherapeutic management of ACC.

Research progress on ferroptosis in diabetic kidney disease

Ferroptosis is a newly discovered form of cell death that differs from other forms of regulated cell death at morphological, biochemical, and genetic levels, and is characterized by iron-dependent accumulation of lipid peroxides. Ferroptosis is closely related to intracellular metabolism of amino acids, lipids, and iron. Hence, its regulation may facilitate disease intervention and treatment. Diabetic kidney disease is one of the most serious complications of diabetes, which leads to serious psychological and economic burdens to patients and society when it progresses to end-stage renal disease. At present, there is no effective treatment for diabetic kidney disease. Ferroptosis has been recently identified in animal models of diabetic kidney disease. Herein, we systematically reviewed the regulatory mechanism of ferroptosis, its association with different forms of cell death, summarized its relationship with diabetic kidney disease, and explored its regulation to intervene with the progression of diabetic kidney disease or as a treatment.