Metformin attenuates hyperlipidaemia-associated vascular calcification through anti-ferroptotic effects

Role of macrophages in vascular calcification: From the perspective of homeostasis

Vascular calcification (VC) is a crucial risk factor for the high morbidity and mortality associated with cardiovascular and cerebrovascular diseases. With the global population aging, the incidence of VC is escalating annually. However, due to its silent clinical process, VC often results in irreversible clinical outcomes. Inflammation is a core element in the VC process, and macrophages are the major inflammatory cells. Due to their diverse origins, microenvironments, and polarization states, macrophages exhibit significant heterogeneity, exerting strong effects on the occurrence, development, and even the regression of VC. In this review, we summarize the origin, distribution, classification, and surface markers of macrophages. Simultaneously, we explore the mechanisms by which macrophages maintain homeostasis or regulate inflammation, including the macrophage-mediated regulation of VC through the release of inflammatory factors, osteogenic genes, extracellular vesicles, and alterations in efferocytosis. Finally, we discuss research targeting inflammation and macrophages to develop novel therapeutic regimens for preventing and treating VC.

Histone deacetylase 9 promotes osteogenic trans-differentiation of vascular smooth muscle cells via ferroptosis in chronic kidney disease vascular calcification

Vascular calcification, a common complication of chronic kidney disease (CKD), remains an unmet therapeutic challenge. The trans-differentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells is crucial in the pathogenesis of vascular calcification in CKD. Despite ferroptosis promotes vascular calcification in CKD, the upstream or downstream regulatory mechanisms involved remains unclear. In this study, we aimed to investigate the regulatory mechanism involved in ferroptosis in CKD vascular calcification. Transcriptome sequencing revealed a potential relationship between HDAC9 and ferroptosis in CKD vascular calcification. Subsequently, we observed increased expression of HDAC9 in calcified arteries of patients undergoing hemodialysis and in a rat model of CKD. We further demonstrated that knockout of HDAC9 attenuates osteogenic trans-differentiation and ferroptosis in VSMCs stimulated by high calcium and phosphorus. In addition, RSL3 exacerbated ferroptosis and osteogenic trans-differentiation of VSMCs exposed to high levels of calcium and phosphorus, and these effects were suppressed to some extent by HDAC9 knockout. In summary, our findings suggest that HDAC9 promotes VSMCs osteogenic trans-differentiation involving ferroptosis, providing new insights for the therapy of CKD vascular calcification.

Lipocalin-2 promotes CKD vascular calcification by aggravating VSMCs ferroptosis through NCOA4/FTH1-mediated ferritinophagy

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD), for which no effective therapies are available. Hyperphosphatemia, a feature of CKD, is a well-known inducer of VC. High phosphate (HP)-induced ferroptosis plays a crucial role in CKD-related VC (CKD-VC), but the mechanisms remain unclear. Lipocalin-2 (LCN2), an iron-trafficking protein, has been implicated in ferroptosis regulation. In the present study, the role of LCN2 as a potential mediator of CKD-VC was investigated. HP-induced LCN2 expression in the arteries of CKD-VC patients, animal models and vascular smooth muscle cells (VSMCs). LCN2 knockout (LCN2KO) mice and wild-type (WT) mice fed with a high adenine and phosphate (AP) diet were studied to explore CKD-VC. Compared with WT mice, LCN2KO mice showed an amelioration of the CKD-VC induced by the AP diet. The inhibition of LCN2 also alleviated HP-induced calcium deposition and phenotypic transition in VSMCs. Conversely, VSMCs-targeted LCN2 overexpression or recombinant LCN2 treatment exacerbated CKD-VC in vivo and in vitro. Mechanistically, nuclear receptor coactivator 4 (NCOA4)/ferritin heavy chain 1 (FTH1)-mediated ferritinophagy-dependent ferroptosis was involved in LCN2-mediated CKD-VC. Under HP conditions, LCN2 interacted with NCOA4, potentially accelerating the degradation of FTH1 and inducing ferroptosis. The inhibition of LCN2 may rescue the degradation of FTH1 and thus ameliorate ferroptosis, significantly suppressing VSMCs calcification. In summary, our study revealed a novel role for LCN2 induced ferritinophagy-dependent ferroptosis in CKD-VC, and targeting LCN2 might be a promising treatment for CKD-VC.

sEV-mediated lipid droplets transferred from bone marrow adipocytes promote ferroptosis and impair osteoblast function

Osteoporosis is linked to increased bone marrow adipocyte (BMAd) proliferation, which displaces bone-forming cells and alters the local environment. The impact of BMAd lipid droplets on bone health and osteoblast function remains unclear. This study investigates the interplay between BMAd-derived lipid droplets and osteoblast functionality, focusing on ferroptosis pathways. Osteoblast cultures were treated with conditioned media from adipocytes to simulate in vivo conditions. High-throughput mRNA sequencing and Western blot analysis were used to profile changes in gene expression and protein levels related to ferroptosis, oxidative phosphorylation, and osteogenic markers. Cellular assays assessed the direct impact of lipid droplets on osteoblast activity. Results showed that osteoblasts exposed to adipocyte-conditioned media had increased intracellular lipid droplet accumulation, upregulation of ferroptosis-related genes and proteins, and downregulation of oxidative phosphorylation and osteoblast differentiation markers. Treatment with ferroptosis inhibitors reversed the detrimental effects on osteoblasts, indicating the functional relevance of this pathway in osteoporosis. BMAd-derived lipid droplets contribute to osteoblast dysfunction through ferroptosis induction. Inhibiting ferroptosis could preserve osteoblast function and combat osteoporosis-related bone issues, suggesting that modulating lipid metabolism and redox balance in bone cells may be promising for future treatments.

Regulated vascular smooth muscle cell death in vascular diseases

Regulated cell death (RCD) is a complex process that involves several cell types and plays a crucial role in vascular diseases. Vascular smooth muscle cells (VSMCs) are the predominant elements of the medial layer of blood vessels, and their regulated death contributes to the pathogenesis of vascular diseases. The types of regulated VSMC death include apoptosis, necroptosis, pyroptosis, ferroptosis, parthanatos, and autophagy-dependent cell death (ADCD). In this review, we summarize the current evidence of regulated VSMC death pathways in major vascular diseases, such as atherosclerosis, vascular calcification, aortic aneurysm and dissection, hypertension, pulmonary arterial hypertension, neointimal hyperplasia, and inherited vascular diseases. All forms of RCD constitute a single, coordinated cell death system in which one pathway can compensate for another during disease progression. Pharmacologically targeting RCD pathways has potential for slowing and reversing disease progression, but challenges remain. A better understanding of the role of regulated VSMC death in vascular diseases and the underlying mechanisms may lead to novel pharmacological developments and help clinicians address the residual cardiovascular risk in patients with cardiovascular diseases.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

The significance of serum SLC7A11 levels in the occurrence of vascular calcification in maintenance peritoneal dialysis patients

AIM

This research aimed to explore the serum levels of solute carrier family 7 member 11 (SLC7A11) in patients with maintenance peritoneal dialysis (MPD) and its correlation with vascular calcification (VC) and clinical results.

METHODS

This present prospective observational cohort study enrolled 189 patients with MPD who were undergoing regular peritoneal dialysis for over 3 months in our hospital from February 2020 to July 2022. The abdominal aortic calcification score was used to assess the VC condition of MPD patients. The serum SLC7A11, interleukin (IL)-6, IL-1β and C-reactive protein levels were measured by enzyme-linked immunosorbent assay (ELISA). Demographic and clinical statistics were collected. All patients were followed up for 1 year and the overall survival time (OS) of all patients were recorded. All data used SPSS 18.0 for statistical analyses.

RESULTS

Patients with moderate/severe calcification in MPD had a longer duration of dialysis, higher serum levels of phosphate (P) and calcium (Ca) and lower serum levels of SLC7A11. Spearman's analysis revealed a negative correlation between serum SLC7A11 levels and the levels of P, Ca and IL-1β. Additionally, we observed an association between serum SLC7A11 levels and clinical prognosis as well as the extent of VC in MPD patients. Multivariate logistic regression analysis indicated that dialysis duration, SLC7A11, and P were risk factors for VC in MPD patients.

CONCLUSION

The serum SLC7A11 levels decreased remarkably in MPD patients with moderate/severe calcification. This study may provide new targets and comprehensive approach to cardiovascular protection in patients with chronic kidney disease.

Anti-hypertensive effect and potential mechanism of gastrodia-uncaria granules based on network pharmacology and experimental validation

Hypertension has become a major contributor to the morbidity and mortality of cardiovascular diseases worldwide. Despite the evidence of the anti-hypertensive effect of gastrodia-uncaria granules (GUG) in hypertensive patients, little is known about its potential therapeutic targets as well as the underlying mechanism. GUG components were sourced from TCMSP and HERB, with bioactive ingredients screened. Hypertension-related targets were gathered from DisGeNET, OMIM, GeneCards, CTD, and GEO. The STRING database constructed a protein-protein interaction network, visualized by Cytoscape 3.7.1. Core targets were analyzed via GO and KEGG using R package ClusterProfiler. Molecular docking with AutodockVina 1.2.2 revealed favorable binding affinities. In vivo studies on hypertensive mice and rats validated network pharmacology findings. GUG yielded 228 active ingredients and 1190 targets, intersecting with 373 hypertension-related genes. PPI network analysis identified five core genes: AKT1, TNF-α, GAPDH, IL-6, and ALB. Top enriched GO terms and KEGG pathways associated with the anti-hypertensive properties of GUG were documented. Molecular docking indicated stable binding of core components to targets. In vivo study showed that GUG could improve vascular relaxation, alleviate vascular remodeling, and lower blood pressure in hypertensive animal models possibly through inhibiting inflammatory factors such as AKT1, mTOR, and CCND1. Integrated network pharmacology and in vivo experiment showed that GUG may exert anti-hypertensive effects by inhibiting inflammation response, which provides some clues for understanding the effect and mechanisms of GUG in the treatment of hypertension.

Nesfatin-1 mitigates calcific aortic valve disease via suppressing ferroptosis mediated by GSH/GPX4 and ZIP8/SOD2 axes

OBJECTIVE

Calcific aortic valve disease (CAVD) predominantly affects the elderly and currently lacks effective medical treatments. Nesfatin-1, a peptide derived from the cleavage of Nucleobindin 2, has been implicated in various calcification processes, both physiological and pathological. This study explores the impact of Nesfatin-1 on the transformation of aortic valve interstitial cells (AVICs) in CAVD.

METHODS AND RESULTS

In vitro experiments showed that Nesfatin-1 treatment mitigated the osteogenic differentiation of AVICs. Corresponding in vivo studies demonstrated a deceleration in the progression of CAVD. RNA-sequencing of AVICs treated with and without Nesfatin-1 highlighted an enrichment of the Ferroptosis pathway among the top pathways identified by the Kyoto Encyclopedia of Genes and Genomes analysis. Further examination confirmed increased ferroptosis in both calcified valves and osteoblast-like AVICs, with a reduction in ferroptosis following Nesfatin-1 treatment. Within the Ferroptosis pathway, ZIP8 showed the most notable modulation by Nesfatin-1. Silencing ZIP8 in AVICs increased ferroptosis and osteogenic differentiation, decreased intracellular Mn2+ concentration, and reduced the expression and activity of superoxide dismutase (SOD2). Furthermore, the silencing of SOD2 exacerbated ferroptosis and osteogenic differentiation. Nesfatin-1 treatment was found to elevate the expression of glutathione peroxidase 4 (GPX4) and levels of glutathione (GSH), as confirmed by Western blotting and GSH concentration assays.

CONCLUSION

In summary, Nesfatin-1 effectively inhibits the osteogenic differentiation of AVICs by attenuating ferroptosis, primarily through the GSH/GPX4 and ZIP8/SOD2 pathways.

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

JOURNAL/nrgr/04.03/01300535-202409000-00037/figure1/v/2024-01-16T170235Z/r/image-tiff Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models. Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis. Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis. Previous studies have shown that, when used to treat cardiovascular and digestive system diseases, metformin can also upregulate heme oxygenase-1 expression. Therefore, we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury. To test this, we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury. Next, we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis. Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury. Subsequently, we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord, and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury. Taken together, these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury, and that this effect is partially dependent on upregulation of heme oxygenase-1.

Dyslipidemia-induced renal fibrosis related to ferroptosis and endoplasmic reticulum stress

Dyslipidemia may induce chronic kidney disease and trigger both ferroptosis and endoplasmic reticulum (ER) stress, but the instigating factors are incompletely understood. We tested the hypothesis that different models of dyslipidemia engage distinct kidney injury mechanisms. Wild-type (WT) or proprotein-convertase subtilisin/kexin type-9 (PCSK9)-gain-of-function (GOF) Ossabaw pigs were fed with a 6-month normal diet (ND) or high-fat diet (HFD) (n = 5-6 each). Renal function and fat deposition were studied in vivo using CT, and blood and kidney tissue studied ex-vivo for lipid profile, systemic and renal vein FFAs levels, and renal injury mechanisms including lipid peroxidation, ferroptosis, and ER stress. Compared with WT-ND pigs, both HFD and PCSK9-GOF elevated triglyceride levels, which were highest in WT-HFD, whereas total and LDL cholesterol levels rose only in PCSK9-GOF pigs, particularly in PCSK9-GOF/HFD. The HFD groups had worse kidney function than the ND groups. The WT-HFD kidneys retained more FFA than other groups, but all kidneys developed fibrosis. Furthermore, HFD-induced ferroptosis in WT-HFD indicated by increased free iron, lipid peroxidation, and decreased glutathione peroxidase-4 mRNA expression, while PCSK9-GOF induced ER stress with upregulated GRP94 and CHOP protein expression. In vitro, pig kidney epithelial cells treated with palmitic acid and oxidized LDL to mimic HFD and PCSK9-GOF showed similar trends to those observed in vivo. Taken together, HFD-induced hypertriglyceridemia promotes renal FFA retention and ferroptosis, whereas PCSK9-GOF-induced hypercholesterolemia elicits ER stress, both resulting in renal fibrosis. These observations suggest different targets for preventing and treating renal fibrosis in subjects with specific types of dyslipidemia.

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.

Metformin Regulates Cardiac Ferroptosis to Reduce Metabolic Syndrome-Induced Cardiac Dysfunction

High-fat diet-induced metabolic syndrome (MetS) is closely associated with cardiac dysfunction. Recent research studies have indicated a potential association between MetS and ferroptosis. Furthermore, metformin can alleviate MetS-induced cardiac ferroptosis. Metformin is a classic biguanide anti-diabetic drug that has protective effects on cardiovascular diseases, which extend beyond its indirect glycemic control. This study aimed to assess whether MetS mediates cardiac ferroptosis, thereby causing oxidative stress and mitochondrial dysfunction. The results revealed that metformin can mitigate cardiac reactive oxygen species and mitochondrial damage, thereby preserving cardiac function. Mechanistic analysis revealed that metformin upregulates the expression of cardiac Nrf2. Moreover, Nrf2 downregulation compromises the cardio-protective effects of metformin. In summary, this study indicated that MetS promotes cardiac ferroptosis, and metformin plays a preventive and therapeutic role, partially through modulation of Nrf2 expression.

Aristolochic acids-hijacked p53 promotes liver cancer cell growth by inhibiting ferroptosis

Aristolochic acids (AAs) have been identified as a significant risk factor for hepatocellular carcinoma (HCC). Ferroptosis is a type of regulated cell death involved in the tumor development. In this study, we investigated the molecular mechanisms by which AAs enhanced the growth of HCC. By conducting bioinformatics and RNA-Seq analyses, we found that AAs were closely correlated with ferroptosis. The physical interaction between p53 and AAs in HepG2 cells was validated by bioinformatics analysis and SPR assays with the binding pocket sites containing Pro92, Arg174, Asp207, Phe212, and His214 of p53. Based on the binding pocket that interacts with AAs, we designed a mutant and performed RNA-Seq profiling. Interestingly, we found that the binding pocket was responsible for ferroptosis, GADD45A, NRF2, and SLC7A11. Functionally, the interaction disturbed the binding of p53 to the promoter of GADD45A or NRF2, attenuating the role of p53 in enhancing GADD45A and suppressing NRF2; the mutant did not exhibit the same effects. Consequently, this event down-regulated GADD45A and up-regulated NRF2, ultimately inhibiting ferroptosis, suggesting that AAs hijacked p53 to down-regulate GADD45A and up-regulate NRF2 in HepG2 cells. Thus, AAs treatment resulted in the inhibition of ferroptosis via the p53/GADD45A/NRF2/SLC7A11 axis, which led to the enhancement of tumor growth. In conclusion, AAs-hijacked p53 restrains ferroptosis through the GADD45A/NRF2/SLC7A11 axis to enhance tumor growth. Our findings provide an underlying mechanism by which AAs enhance HCC and new insights into p53 in liver cancer. Therapeutically, the oncogene NRF2 is a promising target for liver cancer.

Molecular mechanism of ferroptosis and its application in the treatment of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common malignant tumor of the urinary tract, the incidence of which is continuously increasing and affects human health worldwide. Despite advances in existing treatments, treatment outcomes still need to be improved due to higher rates of postoperative recurrence, chemotherapy resistance, etc.; thus, there is an urgent need for innovative therapeutic approaches. Ferroptosis is a recently found type of regulated cell death that is characterized primarily by the buildup of lipid peroxidation products and fatal reactive oxygen species created by iron metabolism, which plays a crucial role in tumor progression and therapy.With the molecular mechanisms associated with ferroptosis being increasingly studied and refined, triggering ferroptosis by regulators that target ferroptosis and ccRCC may be the key to developing potential therapeutic strategies for ccRCC. Therefore, ferroptosis is expected to be a new breakthrough in treating ccRCC. This paper examines the mechanism of ferroptosis, the regulatory mechanism of ferroptosis in ccRCC, and the potential application of ferroptosis in combination with other therapies for the treatment of ccRCC. The goal is to offer novel perspectives for the research and clinical application of ferroptosis in the treatment of ccRCC.

Transcriptome-centric approach to the derivation of adverse outcome pathway networks of vascular dysfunction after long-term low-level exposure of human endothelial cells to dibutyl phthalate

Dibutyl phthalate (DBP) is an endocrine disruptor that adversely affects reproduction; however, evidence suggests it can also impact other systems, including vascular function. The mechanisms underlying DBP-induced vascular dysfunction, particularly after long-term low-level exposure of endothelial cells to this phthalate, remain largely unknown. To address this gap, we used experimentally derived data on differentially expressed genes (DEGs) obtained after 12 weeks of exposure of human vascular endothelial cells EA.hy926 to the concentrations of DBP to which humans are routinely exposed (10-9 M, 10-8 M, and 10-7 M) and various computational tools and manual data curation to build the first adverse outcome pathway (AOP) network relevant to DBP-induced vascular toxicity. DEGs were used to infer transcription factors (molecular initiating events) and molecular functions and biological processes (key events, KEs) using the Enrichr database. The AOP-helpFinder 2.0, an artificial intelligence-based web tool, was used to link genes and KEs and assign confidence scores to co-occurred terms. We constructed the AOP networks using Cytoscape and then manually arranged KEs to depict the flow of mechanistic information across different levels of network organization. An AOP network was created for each DBP concentration, revealing several distinct high-confidence subnetworks that could be involved in DBP-induced vascular toxicity: the insulin-like growth factor subnetwork for 10-7 M DBP, the CXCL8-dependent chemokine subnetwork for 10-8 M DBP, and the fatty acid subnetwork for 10-9 M DBP. We also developed an AOP network providing a mechanistic insight into the dose-dependent effects of DBP in endothelial cells leading to vascular dysfunction. In summary, we present novel putative AOP networks describing the mechanistic flow of information involved in DBP-induced vascular dysfunction in a long-term low-level exposure scenario.

Sodium tanshinone IIA sulfonate protects vascular relaxation in ApoE-knockout mice by inhibiting the SYK-NLRP3 inflammasome-MMP2/9 pathway

BACKGROUND

Hyperlipidemia damages vascular wall and serves as a foundation for diseases such as atherosclerosis, hypertension and stiffness. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is implicated in vascular dysfunction associated with hyperlipidemia-induced vascular injury. Sodium tanshinone IIA sulfonate (STS), a well-established cardiovascular protective drug with recognized anti-inflammatory, antioxidant, and vasodilatory properties, is yet to be thoroughly investigated for its impact on vascular relaxant imbalance induced by hyperlipidemia.

METHODS

In this study, we treated ApoE-knockout (ApoE-/-) mouse with STS and assessed the activation of the NLRP3 inflammasome, expression of MMP2/9, integrity of elastic fibers, and vascular constriction and relaxation.

RESULTS

Our findings reveal that STS intervention effectively preserves elastic fibers, significantly restores aortic relaxation function in ApoE-/- mice, and reduces their excessive constriction. Furthermore, STS inhibits the phosphorylation of spleen tyrosine kinase (SYK), suppresses NLRP3 inflammasome activation, and reduces MMP2/9 expression.

CONCLUSIONS

These results demonstrate that STS protects vascular relaxation against hyperlipidemia-induced damage through modulation of the SYK-NLRP3 inflammasome-MMP2/9 pathway. This research provides novel insights into the mechanisms underlying vascular relaxation impairment in a hyperlipidemic environment and uncovers a unique mechanism by which STS preserves vascular relaxation, offering valuable foundational research evidence for its clinical application in promoting vascular health.

Lipotoxicity: The missing link between diabetes and periodontitis?

Lipotoxicity refers to the accumulation of lipids in tissues other than adipose tissue (body fat). It is one of the major pathophysiological mechanisms responsible for the progression of diabetes complications such as non-alcoholic fatty liver disease and diabetic nephropathy. Accumulating evidence indicates that lipotoxicity also contributes significantly to the toxic effects of diabetes on periodontitis. Therefore, we reviewed the current in vivo, in vitro, and clinical evidence of the detrimental effects of lipotoxicity on periodontitis, focusing on its molecular mechanisms, especially oxidative and endoplasmic reticulum stress, inflammation, ceramides, adipokines, and programmed cell death pathways. By elucidating potential therapeutic strategies targeting lipotoxicity and describing their associated mechanisms and clinical outcomes, including metformin, statins, liraglutide, adiponectin, and omega-3 PUFA, this review seeks to provide a more comprehensive and effective treatment framework against diabetes-associated periodontitis. Furthermore, the challenges and future research directions are proposed, aiming to contribute to a more profound understanding of the impact of lipotoxicity on periodontitis.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Ferroptosis inhibitors: past, present and future

Ferroptosis is a non-apoptotic mode of programmed cell death characterized by iron dependence and lipid peroxidation. Since the ferroptosis was proposed, researchers have revealed the mechanisms of its formation and continue to explore effective inhibitors of ferroptosis in disease. Recent studies have shown a correlation between ferroptosis and the pathological mechanisms of neurodegenerative diseases, as well as diseases involving tissue or organ damage. Acting on ferroptosis-related targets may provide new strategies for the treatment of ferroptosis-mediated diseases. This article specifically describes the metabolic pathways of ferroptosis and summarizes the reported mechanisms of action of natural and synthetic small molecule inhibitors of ferroptosis and their efficacy in disease. The paper also describes ferroptosis treatments such as gene therapy, cell therapy, and nanotechnology, and summarises the challenges encountered in the clinical translation of ferroptosis inhibitors. Finally, the relationship between ferroptosis and other modes of cell death is discussed, hopefully paving the way for future drug design and discovery.

The NRF2/ID2 Axis in Vascular Smooth Muscle Cells: Novel Insights into the Interplay between Vascular Calcification and Aging

Vascular calcification (VC) increases with age and markedly exacerbates the risk of cardiovascular morbidity and mortality. However, effective pharmaceutical interventions are lacking and the molecular mechanisms linking aging to VC remain elusive. This study explored the role of nuclear factor erythroid 2-related factor 2 (NRF2) in age-associated VC, specifically focusing on vascular smooth muscle cell (VSMC) senescence. Using a chronologically aging mouse model, we noted a significant decline in the expression of NRF2 in the aged mice aortas, coinciding with increased VC. Administering NRF2 activators effectively reduced calcification. By establishing adenine-and vitamin D-induced VC models in VSMC-specific Nrf2 knockout (Nrf2SMCKO) mice, there was an increase in VC with increased VSMC senescence. Aortic rings and primary VSMCs from Nrf2SMCKO mice also showed increased VC under high-phosphate conditions. Furthermore, Nrf2 overexpression inhibited VSMC calcification with decreased VSMC senescence and an osteogenic phenotype, whereas Nrf2 silencing aggravated calcification. Transcriptome RNA-seq analysis of the aortas from Nrf2SMCKO and control mice revealed that inhibitor of DNA binding 2 (Id2) is a core downstream gene of NRF2. Id2 overexpression alleviated NRF2 knockdown-induced VC and VSMC senescence, while silencing Id2 negated the protective effects of NRF2. Moreover, results of a dual luciferase reporter assay indicated that NRF2 promotes the transcriptional activity of the Id2 gene promoter region. This study emphasizes the critical role of age-related NRF2 dysfunction in the nexus between VSMC senescence and VC. The NRF2-ID2 axis in VSMCs has been proposed as a promising therapeutic target for reducing VC and mitigating age-related cardiovascular diseases.

Molecular mechanisms and potential therapeutic targets in the pathogenesis of hypertension in visceral adipose tissue induced by a high-fat diet

Background

Hypertension (HTN) presents a significant global public health challenge with diverse causative factors. The accumulation of visceral adipose tissue (VAT) due to a high-fat diet (HFD) is an independent risk factor for HTN. While various studies have explored pathogenic mechanisms, a comprehensive understanding of impact of VAT on blood pressure necessitates bioinformatics analysis.

Methods

Datasets GSE214618 and GSE188336 were acquired from the Gene Expression Omnibus and analyzed to identify shared differentially expressed genes between HFD-VAT and HTN-VAT. Gene Ontology enrichment and protein-protein interaction analyses were conducted, leading to the identification of hub genes. We performed molecular validation of hub genes using RT-qPCR, Western-blotting and immunofluorescence staining. Furthermore, immune infiltration analysis using CIBERSORTx was performed.

Results

This study indicated that the predominant characteristic of VAT in HTN was related to energy metabolism. The red functional module was enriched in pathways associated with mitochondrial oxidative respiration and ATP metabolism processes. Spp1, Postn, and Gpnmb in VAT were identified as hub genes on the pathogenic mechanism of HTN. Proteins encoded by these hub genes were closely associated with the target organs-specifically, the resistance artery, aorta, and heart tissue. After treatment with empagliflozin, there was a tendency for Spp1, Postn, and Gpnmb to decrease in VAT. Immune infiltration analysis confirmed that inflammation and immune response may not be the main mechanisms by which visceral adiposity contributes to HTN.

Conclusions

Our study pinpointed the crucial causative factor of HTN in VAT following HFD. Spp1, Postn, and Gpnmb in VAT acted as hub genes that promote elevated blood pressure and can be targets for HTN treatment. These findings contributed to therapeutic strategies and prognostic markers for HTN.

Oxidized phospholipid POVPC contributes to vascular calcification by triggering ferroptosis of vascular smooth muscle cells

Vascular calcification is an actively regulated biological process resembling bone formation, and osteogenic differentiation of vascular smooth muscle cells (VSMCs) plays a crucial role in this process. 1-Palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), an oxidized phospholipid, is found in atherosclerotic plaques and has been shown to induce oxidative stress. However, the effects of POVPC on osteogenic differentiation and calcification of VSMCs have yet to be studied. In the present study, we investigated the role of POVPC in vascular calcification using in vitro and ex vivo models. POVPC increased mineralization of VSMCs and arterial rings, as shown by alizarin red staining. In addition, POVPC treatment increased expression of osteogenic markers Runx2 and BMP2, indicating that POVPC promotes osteogenic transition of VSMCs. Moreover, POVPC increased oxidative stress and impaired mitochondria function of VSMCs, as shown by increased ROS levels, impairment of mitochondrial membrane potential, and decreased ATP levels. Notably, ferroptosis triggered by POVPC was confirmed by increased levels of intracellular ROS, lipid ROS, and MDA, which were decreased by ferrostatin-1, a ferroptosis inhibitor. Furthermore, ferrostatin-1 attenuated POVPC-induced calcification of VSMCs. Taken together, our study for the first time demonstrates that POVPC promotes vascular calcification via activation of VSMC ferroptosis. Reducing the levels of POVPC or inhibiting ferroptosis might provide a novel strategy to treat vascular calcification.

Interplay between lipid dysregulation and ferroptosis in chondrocytes and the targeted therapy effect of metformin on osteoarthritis

INTRODUCTION

Osteoarthritis (OA) is a devastating whole-joint disease affecting a large population worldwide; the role of lipid dysregulation in OA and mechanisms underlying targeted therapy effect of lipid-lowering metformin on OA remains poorly defined.

OBJECTIVES

To investigate the effects of lipid dysregulation on OA progression and to explore lipid dysregulation-targeting OA treatment of metformin.

METHODS

RNA-Seq data, biochemical, and histochemical assays in human and murine OA cartilage as well as primary chondrocytes were utilized to determine lipid dysregulation. Effects of metformin, a potent lipid-lowering medication, on ACSL4 expression and chondrocyte metabolism were determined. Further molecular experiments, including RT-qPCR, western blotting, flow cytometry, and immunofluorescence staining, were performed to investigate underlying mechanisms. Mice with intra-articular injection of metformin were utilized to determine the effects on ACLT-induced OA progression.

RESULTS

ACSL4 and 4-HNE expressions were elevated in human and ACLT-induced mouse OA cartilage and IL-1β-treated chondrocytes (P < 0.05). Ferrostatin-1 largely rescued IL-1β-induced MDA, lipid peroxidation, and ferroptotic mitochondrial morphology (P < 0.05). Metformin decreased the levels of OA-related genes (P < 0.05) and increased the levels of p-AMPK and p-ACC in IL-1β-treated chondrocytes. Intra-articular injection of metformin alleviated ACLT-induced OA lesions in mice, and reverted the percentage of chondrocytes positive for MMP13, Col2a1, ACSL4 and 4-HNE in ACLT mice (P < 0.05). Ferroptotic chondrocytes promoted the recruitment and chemotaxis of RAW264.7 cells via CCL2, which was blocked by metformin in vitro (P < 0.05).

CONCLUSION

We establish a critical role of polyunsaturated fatty acids metabolic process in OA cartilage degradation and define metformin as a potential OA treatment. Metformin reshapes lipid availability and ameliorates chondrocyte ferroptosis sensitivity via the AMPK/ACC pathway. In the future, gene-edited animals and extensive omics technologies will be utilized to reveal detailed lipids' involvement in cartilage lesions.

Silencing of METTL3 suppressed ferroptosis of myocardial cells by m6A modification of SLC7A11 in a YTHDF2 manner

Myocardial infarction (MI) is the main cause of heart failure (HF). N6-methyladenosine (m6A) methylation is associated with the progression of HF. The study aimed to explore whether METTL3 regulates ferroptosis of cardiomyocytes in HF. We evaluated ferroptosis by detecting lactic dehydrogenase (LDH) release, lipid reactive oxygen species (ROS), Fe2+, glutathione (GSH), and malonaldehyde (MDA) levels. M6A methylation was assessed using methylated RNA immunoprecipitation assay. The binding relationship was assessed using RNA immunoprecipitation assays. The mRNA stability was assessed using actinomycin D treatment. The results showed that METTL3 was upregulated in oxygen glucose deprivation/recovery (OGD/R) cells, which knockdown suppressed OGD/R-induced ferroptosis. Moreover, METTL3 could bind to SLC7A11, promoting m6A methylation of SLC7A11. Silencing of SLC7A11 abrogated the suppression of ferroptosis induced by METTL3 knockdown. Additionally, YTHDF2 was the reader that recognized the methylation of SLC7A11, reducing the stability of SLC7A11. The silencing of METTL3 inhibited OGD/R-induced ferroptosis by suppressing the m6A methylation of SLC7A11, which is recognized by YTHDF2. The findings suggested that METTL3-mediated ferroptosis might be a new strategy for MI-induced HF therapy.

Ferroptosis mechanisms and regulations in cardiovascular diseases in the past, present, and future

Cardiovascular diseases (CVDs) are the main diseases that endanger human health, and their risk factors contribute to high morbidity and a high rate of hospitalization. Cell death is the most important pathophysiology in CVDs. As one of the cell death mechanisms, ferroptosis is a new form of regulated cell death (RCD) that broadly participates in CVDs (such as myocardial infarction, heart transplantation, atherosclerosis, heart failure, ischaemia/reperfusion (I/R) injury, atrial fibrillation, cardiomyopathy (radiation-induced cardiomyopathy, diabetes cardiomyopathy, sepsis-induced cardiac injury, doxorubicin-induced cardiac injury, iron overload cardiomyopathy, and hypertrophic cardiomyopathy), and pulmonary arterial hypertension), involving in iron regulation, metabolic mechanism and lipid peroxidation. This article reviews recent research on the mechanism and regulation of ferroptosis and its relationship with the occurrence and treatment of CVDs, aiming to provide new ideas and treatment targets for the clinical diagnosis and treatment of CVDs by clarifying the latest progress in CVDs research.

Metformin improves nonalcoholic fatty liver disease in db/db mice by inhibiting ferroptosis

Nonalcoholic fatty liver disease (NAFLD) is the primary complication of type 2 diabetes (T2DM)-related liver disease, lacking effective treatment options. Metformin (Met), a widely prescribed anti-hyperglycemic medication, has been found to protect against NAFLD. Ferroptosis, a newly discovered form of cell death, is associated with the development of NAFLD. Despite this association, the extent of Met's protective effects on NAFLD through the modulation of ferroptosis has yet to be thoroughly investigated. In the present study, the administration of erastin or Ras-selective lethal 3 (RSL3), both known ferroptosis inducers, resulted in elevated cell mortality and reduced cell viability in AML12 hepatocytes. Notably, Met treatment demonstrated the capacity to mitigate these effects. Furthermore, we observed increased ferroptosis levels in both AML12 hepatocytes treated with palmitate and oleate (PA/OA) and in the liver tissue of db/db mice. Met treatment demonstrated significant reductions in iron accumulation and lipid-related reactive oxygen species production, simultaneously elevating the glutathione/glutathione disulfide ratio in both PA/OA-treated AML12 hepatocytes and the liver tissue of db/db mice. Interestingly, the anti-ferroptosis effects of Met were significantly reversed with the administration of RSL3, both in vitro and in vivo. Mechanistically, Met treatment regulated the glutathione peroxidase 4/solute carrier family 7 member 11/acyl-CoA synthetase long-chain family member 4 axis to alleviate ferroptosis in NAFLD hepatocytes. Overall, our findings highlight the crucial role of ferroptosis in the development of T2DM-related NAFLD and underscore the potential of Met in modulating key factors associated with ferroptosis in the context of NAFLD.

Allogeneic platelet-rich plasma inhibits ferroptosis in promoting wound repair of type 2 diabetic ulcers

Increasing evidence has revealed the emerging role of ferroptosis in the pathophysiology of type 2 diabetes mellitus (T2DM) and its complications. Platelet-rich plasma (PRP) has been demonstrated to facilitate the healing of T2DM ulcers. However, the mechanism by which PRP repairs T2DM ulcers remains unclear. Here, we sought to investigate the interaction between PRP and ferroptosis in repairing T2DM ulcers. The results showed that the cellular activity, proliferation, and migration of fibroblasts were down-regulated, and the cellular activity and normal function of vascular endothelial cells were impaired in the high glucose environment or under RSL3 conditions (a GSH peroxidase 4 inhibitor and ferroptosis inducer). Additionally, both cells experienced over-activation of multiple forms of reactive oxygen species (ROS) and lipid peroxidation. In the T2DM rat model, we observed a decreased rate of ulcer wound healing, impaired proliferative capacity, diminished vascular regeneration, and marked inflammation and hyperfibrosis. More importantly, there was typical damage to mitochondria, increased levels of iron ions, and consistent alterations in protein expression of ferroptosis-related factors. These factors include cyclooxygenase-2 (COX2), glutathione peroxidase 4 (GPX4), transferrin receptor (TFRC), and Solute Carrier Family 7 Member 11 (SLC7A11), among others. Due to the strong association between ferroptosis and T2DM ulcers, the use of allogeneic platelet-rich plasma (Al-PRP) exhibited physiological effects similar to those of the ferroptosis inhibitor Ferrostatin-1 (Fer-1). In vivo experiments, both drugs inhibited a range of impediments to wound healing caused by T2DM and ameliorated the adverse effects associated with ferroptosis. Moreover, Al-PRP attenuated the impairment of normal cellular function, activation of ROS and lipid peroxidation induced by high glucose or RSL3. These results suggested that ferroptosis was involved in the development of T2DM ulcers, which could be treated with Al-PRP by inhibiting ferroptosis, and inhibition of ferroptosis may be a suitable treatment strategy for T2DM ulcers.

Mitochondrial DNA leakage triggers inflammation in age-related cardiovascular diseases

Mitochondrial dysfunction is one of the hallmarks of cardiovascular aging. The leakage of mitochondrial DNA (mtDNA) is increased in senescent cells, which are resistant to programmed cell death such as apoptosis. Due to its similarity to prokaryotic DNA, mtDNA could be recognized by cellular DNA sensors and trigger innate immune responses, resulting in chronic inflammatory conditions during aging. The mechanisms include cGAS-STING signaling, TLR-9 and inflammasomes activation. Mitochondrial quality controls such as mitophagy could prevent mitochondria from triggering harmful inflammatory responses, but when this homeostasis is out of balance, mtDNA-induced inflammation could become pathogenic and contribute to age-related cardiovascular diseases. Here, we summarize recent studies on mechanisms by which mtDNA promotes inflammation and aging-related cardiovascular diseases, and discuss the potential value of mtDNA in early screening and as therapeutic targets.

The mechanisms of ferroptosis and its role in atherosclerosis

Ferroptosis is a newly identified form of non-apoptotic programmed cell death, characterized by the iron-dependent accumulation of lethal lipid reactive oxygen species (ROS) and peroxidation of membrane polyunsaturated fatty acid phospholipids (PUFA-PLs). Ferroptosis is unique among other cell death modalities in many aspects. It is initiated by excessive oxidative damage due to iron overload and lipid peroxidation and compromised antioxidant defense systems, including the system Xc-/ glutathione (GSH)/glutathione peroxidase 4 (GPX4) pathway and the GPX4-independent pathways. In the past ten years, ferroptosis was reported to play a critical role in the pathogenesis of various cardiovascular diseases, e.g., atherosclerosis (AS), arrhythmia, heart failure, diabetic cardiomyopathy, and myocardial ischemia-reperfusion injury. Studies have identified dysfunctional iron metabolism and abnormal expression profiles of ferroptosis-related factors, including iron, GSH, GPX4, ferroportin (FPN), and SLC7A11 (xCT), as critical indicators for atherogenesis. Moreover, ferroptosis in plaque cells, i.e., vascular endothelial cell (VEC), macrophage, and vascular smooth muscle cell (VSMC), positively correlate with atherosclerotic plaque development. Many macromolecules, drugs, Chinese herbs, and food extracts can inhibit the atherogenic process by suppressing the ferroptosis of plaque cells. In contrast, some ferroptosis inducers have significant pro-atherogenic effects. However, the mechanisms through which ferroptosis affects the progression of AS still need to be well-known. This review summarizes the molecular mechanisms of ferroptosis and their emerging role in AS, aimed at providing novel, promising druggable targets for anti-AS therapy.

Diabetes Mellitus to Accelerated Atherosclerosis: Shared Cellular and Molecular Mechanisms in Glucose and Lipid Metabolism

Diabetes is one of the critical independent risk factors for the progression of cardiovascular disease, and the underlying mechanism regarding this association remains poorly understood. Hence, it is urgent to decipher the fundamental pathophysiology and consequently provide new insights into the identification of innovative therapeutic targets for diabetic atherosclerosis. It is now appreciated that different cell types are heavily involved in the progress of diabetic atherosclerosis, including endothelial cells, macrophages, vascular smooth muscle cells, dependence on altered metabolic pathways, intracellular lipids, and high glucose. Additionally, extensive studies have elucidated that diabetes accelerates the odds of atherosclerosis with the explanation that these two chronic disorders share some common mechanisms, such as endothelial dysfunction and inflammation. In this review, we initially summarize the current research and proposed mechanisms and then highlight the role of these three cell types in diabetes-accelerated atherosclerosis and finally establish the mechanism pinpointing the relationship between diabetes and atherosclerosis.

The oxidized phospholipid PGPC impairs endothelial function by promoting endothelial cell ferroptosis via FABP3

Ferroptosis is a novel cell death mechanism that is mediated by iron-dependent lipid peroxidation. It may be involved in atherosclerosis development. Products of phospholipid oxidation play a key role in atherosclerosis. 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) is a phospholipid oxidation product present in atherosclerotic lesions. It remains unclear whether PGPC causes atherosclerosis by inducing endothelial cell ferroptosis. In this study, human umbilical vein endothelial cells (HUVECs) were treated with PGPC. Intracellular levels of ferrous iron, lipid peroxidation, superoxide anions (O2•-), and glutathione were detected, and expression of fatty acid binding protein-3 (FABP3), glutathione peroxidase 4 (GPX4), and CD36 were measured. Additionally, the mitochondrial membrane potential (MMP) was determined. Aortas from C57BL6 mice were isolated for vasodilation testing. Results showed that PGPC increased ferrous iron levels, the production of lipid peroxidation and O2•-, and FABP3 expression. However, PGPC inhibited the expression of GPX4 and glutathione production and destroyed normal MMP. These effects were also blocked by ferrostatin-1, an inhibitor of ferroptosis. FABP3 silencing significantly reversed the effect of PGPC. Furthermore, PGPC stimulated CD36 expression. Conversely, CD36 silencing reversed the effects of PGPC, including PGPC-induced FABP3 expression. Importantly, E06, a direct inhibitor of the oxidized 1-palmitoyl-2-arachidonoyl-phosphatidylcholine IgM natural antibody, inhibited the effects of PGPC. Finally, PGPC impaired endothelium-dependent vasodilation, ferrostatin-1 or FABP3 inhibitors inhibited this impairment. Our data demonstrate that PGPC impairs endothelial function by inducing endothelial cell ferroptosis through the CD36 receptor to increase FABP3 expression. Our findings provide new insights into the mechanisms of atherosclerosis and a therapeutic target for atherosclerosis.

P53 together with ferroptosis: a promising strategy leaving cancer cells without escape

TP53, functioning as the keeper of the genome, assumes a pivotal function in the inhibition of tumorigenesis. Recent studies have revealed that p53 regulates ferroptosis pathways within tumor cells and is closely related to tumorigenesis. Therefore, we summarize the pathways and mechanisms by which p53 regulates ferroptosis and identify a series of upstream and downstream molecules involved in this process. Furthermore, we construct a p53-ferroptosis network centered on p53. Finally, we present the progress of drugs to prevent wild-type p53 (wtp53) degeneration and restore wtp53, highlighting the deficiencies of drug development and the prospects for p53 in cancer treatment. These findings provide novel strategies and directions for future cancer therapy.

Ferroptosis and metabolic syndrome and complications: association, mechanism, and translational applications

Metabolic syndrome is a medical condition characterized by several metabolic disorders in the body. Long-term metabolic disorders raise the risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Therefore, it is essential to actively explore the aetiology of metabolic syndrome (MetS) and its comorbidities to provide effective treatment options. Ferroptosis is a new form of cell death that is characterized by iron overload, lipid peroxide accumulation, and decreased glutathione peroxidase 4(GPX4) activity, and it involves the pathological processes of a variety of diseases. Lipid deposition caused by lipid diseases and iron overload is significant in metabolic syndrome, providing the theoretical conditions for developing ferroptosis. Recent studies have found that the major molecules of ferroptosis are linked to common metabolic syndrome consequences, such as T2DM and atherosclerosis. In this review, we first discussed the mechanics of ferroptosis, the regulatory function of inducers and inhibitors of ferroptosis, and the significance of iron loading in MetS. Next, we summarized the role of ferroptosis in the pathogenesis of MetS, such as obesity, type 2 diabetes, and atherosclerosis. Finally, we discussed relevant ferroptosis-targeted therapies and raised some crucial issues of concern to provide directions for future Mets-related treatments and research.

Ferroptosis induction via targeting metabolic alterations in triple-negative breast cancer

Triple-negative breast cancer (TNBC), the most aggressive form of breast cancer, presents severe threats to women's health. Therefore, it is critical to find novel treatment approaches. Ferroptosis, a newly identified form of programmed cell death, is marked by the buildup of lipid reactive oxygen species (ROS) and high iron concentrations. According to previous studies, ferroptosis sensitivity can be controlled by a number of metabolic events in cells, such as amino acid metabolism, iron metabolism, and lipid metabolism. Given that TNBC tumors are rich in iron and lipids, inducing ferroptosis in these tumors is a potential approach for TNBC treatment. Notably, the metabolic adaptability of cancer cells allows them to coordinate an attack on one or more metabolic pathways to initiate ferroptosis, offering a novel perspective to improve the high drug resistance and clinical therapy of TNBC. However, a clear picture of ferroptosis in TNBC still needs to be completely revealed. In this review, we provide an overview of recent advancements regarding the connection between ferroptosis and amino acid, iron, and lipid metabolism in TNBC. We also discuss the probable significance of ferroptosis as an innovative target for chemotherapy, radiotherapy, immunotherapy, nanotherapy and natural product therapy in TNBC, highlighting its therapeutic potential and application prospects.

Efficacy and mechanism of Shenqi Compound in inhibiting diabetic vascular calcification

BACKGROUND

Shenqi Compound (SQC) has been used in clinic for several decades in the prevention and treatment of diabetes and its complications. But this is merely a heritage of experience. The primary aim of this study is to scientifically validate the therapeutic effects of SQC on diabetic vascular calcification (DVC) in an animal model and, simultaneously, uncover its potential underlying mechanisms.

METHOD

Spontaneous diabetic rat- Goto Kakizaki (GK) rats were selected for rat modeling. We meticulously designed three distinct groups: a control group, a model group, and an SQC treatment group to rigorously evaluate the influence of SQC. Utilizing a comprehensive approach that encompassed methods such as pathological staining, western blot analysis, qRT-PCR, and RNA sequencing, we thoroughly investigated the therapeutic advantages and the underlying mechanistic pathways associated with SQC in the treatment of DVC.

RESULT

The findings from this investigation have unveiled the extraordinary efficacy of SQC treatment in significantly mitigating DVC. The underlying mechanisms driving this effect encompass multifaceted facets, including the restoration of aberrant glucose and lipid metabolism, the prevention of phenotypic transformation of vascular smooth muscle cells (VSMCs) into osteogenic-like states, the subsequent inhibition of cell apoptosis, the modulation of inflammation responses, the remodeling of the extracellular matrix (ECM), and the activation of the Hippo-YAP signaling pathway. Collectively, these mechanisms lead to the dissolution of deposited calcium salts, ultimately achieving the desired inhibition of DVC.

CONCLUSION

Our study has provided compelling and robust evidence of the remarkable efficacy of SQC treatment in significantly reducing DVC. This reduction is attributed to a multifaceted interplay of mechanisms, each playing a crucial role in the observed therapeutic effects. Notably, our findings illuminate prospective directions for further research and potential clinical applications in the field of cardiovascular health.

Protective effects of metformin on pancreatic β-cell ferroptosis in type 2 diabetes in vivo

Metformin (Met) is the recommended first-line therapeutic drug for type 2 diabetes mellitus (T2DM) and exerts protective effects on β-cell damage. Ferroptosis, a new form of cell death, is associated with pancreatic islet injury in patients with T2DM. However, the protective effects of Met treatment against β-cell damage through ferroptosis modulation remain under-reported. This study investigated the in vivo effects of Met treatment on pancreatic β-cell ferroptosis using two different diabetic mouse models, namely, low-dose streptozotocin (STZ) and high-fat diet (HFD)-induced diabetic mice and db/db mice. Met treatment significantly restored insulin release, reduced cell mortality, and decreased the overproduction of lipid-related reactive oxygen species in the islets of both STZ/HFD-induced diabetic mice and db/db mice. Administration of the Ras-selective lethal 3 injection significantly attenuated the antiferroptosis effects of Met. Mechanistically, Met treatment alleviated β-cell ferroptosis in T2DM, which was associated with the regulation of the GPX4/ACSL4 axis in the islets. In conclusion, our findings highlight the significance of ferroptosis in T2DM β-cell damage and provide novel insights into the protective effects of Met against islet β cells.

Natural compounds efficacy in complicated diabetes: A new twist impacting ferroptosis

Ferroptosis, as a way of cell death, participates in the body's normal physiological and pathological regulation. Recent studies have shown that ferroptosis may damage glucose-stimulated islets β Insulin secretion and programmed cell death of T2DM target organs are involved in the pathogenesis of T2DM and its complications. Targeting suppression of ferroptosis with specific inhibitors may provide new therapeutic opportunities for previously untreated T2DM and its target organs. Current studies suggest that natural bioactive compounds, which are abundantly available in drugs, foods, and medicinal plants for the treatment of T2DM and its target organs, have recently received significant attention for their various biological activities and minimal toxicity, and that many natural compounds appear to have a significant role in the regulation of ferroptosis in T2DM and its target organs. Therefore, this review summarized the potential treatment strategies of natural compounds as ferroptosis inhibitors to treat T2DM and its complications, providing potential lead compounds and natural phytochemical molecular nuclei for future drug research and development to intervene in ferroptosis in T2DM.

L-type calcium ion channel-mediated activation of autophagy in vascular smooth muscle cells via thonningianin A (TA) alleviates vascular calcification in type 2 diabetes mellitus

Vascular calcification (VC) is associated with increased morbidity and mortality, especially among people with type 2 diabetes mellitus (T2DM). The pathogenesis of vascular calcification is incompletely understood, and until now, there have been no effective therapeutics for vascular calcification. The L-type calcium ion channel in the cell membrane is vital for Ca2+ influx. The effect of L-type calcium ion channels on autophagy remains to be elucidated. Here, the natural compound thonningianin A (TA) was found to ameliorate vascular calcification in T2DM via the activation of L-type calcium ion channels. The results showed that TA had a concentration-dependent ability to decrease the transcriptional and translational expression of the calcification-related proteins runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteopontin (OPN) (P < 0.01) via ATG7-dependent autophagy in β-glycerophosphate (β-GP)- and high glucose (HG)-stimulated primary mouse aortic smooth muscle cells (MASMCs) and alleviate aortic vascular calcification in VitD3-stimulated T2DM mice. However, nifedipine, an inhibitor of L-type calcium ion channels, reversed TA-induced autophagy and Ca2+ influx in MASMCs. Molecular docking analysis revealed that TA was located in the hydrophobic pocket of Cav1.2 α1C and was mainly composed of the residues Ile, Phe, Ala and Met, which confirmed the efficacy of TA in targeting the L-type calcium channel of Cav1.2 on the cell membrane. Moreover, in an in vivo model of vascular calcification in T2DM mice, nifedipine reversed the protective effects of TA on aortic calcification and the expression of the calcification-related proteins RUNX2, BMP2 and OPN (P < 0.01). Collectively, the present results reveal that the activation of cell membrane L-type calcium ion channels can induce autophagy and ameliorate vascular calcification in T2DM. Thonningianin A (TA) can target and act as a potent activator of L-type calcium ion channels. Thus, this research revealed a novel mechanism for autophagy induction via L-type calcium ion channels and provided a potential therapeutic for vascular calcification in T2DM.

Autophagy reduces aortic calcification in diabetic mice by reducing matrix vesicle body-mediated IL-1β release

Vascular calcification (VC) is a common pathological process of cardiovascular disease that occurs in patients with type 2 diabetes mellitus (T2DM). However, the molecular basis of VC progression remains unknown. A GEO dataset (GSE146638) was analyzed to show that microbodies and IL-1β may play important roles in the pathophysiology of VC. The release of matrix vesicle bodies (MVBs) and IL-1β and the colocalization of IL-1β with MVBs or autophagosomes were studied by immunofluorescence in an in vivo diabetes mouse model with aortic calcification and an in vitro high glucose cell calcification model. MVB numbers, IL-1β levels and autophagy were increased in calcified mouse aortas and calcified vascular smooth muscle cells (VSMCs). IL-1β colocalized with MVBs and autophagosomes. The MVBs from calcified VSMCs induced the calcification of normal recipient VSMCs, and this effect was alleviated by silencing IL-1β. The autophagy inducer rapamycin reduced IL-1β expression and calcification in VSMCs, while these processes were induced by the autophagy inhibitor chloroquine. In conclusion, our results suggested that MVBs could carry IL-1β out of cells and induce VC in normal VSMCs, and these processes could be counteracted by autophagy. These results suggested that MVB-mediated IL-1β release may be an effective target for treating vascular calcification.

Metabolic dysfunction-associated steatotic liver disease: ferroptosis related mechanisms and potential drugs

Metabolic dysfunction-associated steatotic liver disease (MASLD) is considered a "multisystem" disease that simultaneously suffers from metabolic diseases and hepatic steatosis. Some may develop into liver fibrosis, cirrhosis, and even hepatocellular carcinoma. Given the close connection between metabolic diseases and fatty liver, it is urgent to identify drugs that can control metabolic diseases and fatty liver as a whole and delay disease progression. Ferroptosis, characterized by iron overload and lipid peroxidation resulting from abnormal iron metabolism, is a programmed cell death mechanism. It is an important pathogenic mechanism in metabolic diseases or fatty liver, and may become a key direction for improving MASLD. In this article, we have summarized the physiological and pathological mechanisms of iron metabolism and ferroptosis, as well as the connections established between metabolic diseases and fatty liver through ferroptosis. We have also summarized MASLD therapeutic drugs and potential active substances targeting ferroptosis, in order to provide readers with new insights. At the same time, in future clinical trials involving subjects with MASLD (especially with the intervention of the therapeutic drugs), the detection of serum iron metabolism levels and ferroptosis markers in patients should be increased to further explore the efficacy of potential drugs on ferroptosis.

Network pharmacology and in vitro experimental verification to reveal the mechanism of Astragaloside IV against kidney ischemia-reperfusion injury

Ischemic acute kidney injury (AKI) is a prevalent disorder among hospitalized patients worldwide. Astragaloside IV (AS-IV) has been shown to protect against ischemic AKI. However, the specific effects and mechanisms of AS-IV on alleviating kidney ischemia-reperfusion (I/R) injury remain unclear. The objective of this research was to elucidate the regulatory targets and mechanisms through which AS-IV protects kidney I/R injury. A combination of network pharmacology, molecular docking, molecular dynamics (MD) simulation, pharmacodynamic study and Western blot were employed to explore the underlying mechanisms. Network pharmacology revealed that ferroptosis was a potential mechanism of AS-IV against kidney I/R injury. Molecular docking and MD simulations demonstrated strong binding affinity between the GPX4/SLC7A11 and AS-IV. The experimental verification demonstrated that AS-IV improved cell proliferation, decreased the level of ROS and Fe2+, and increased the expressions of GPX4 and SLC7A11 as same as Ferrostatin-1 in OGD/R-injured HUVECs. In conclusion, AS-IV had a significant inhibition on ferroptosis in kidney I/R injury, providing a new perspective for drug development on kidney I/R injury. Definitely, further exploration in vivo is necessary to fully understand whether AS-IV alleviates kidney I/R injury through inhibiting endothelial ferroptosis.

Metformin alleviates glucolipotoxicity-induced pancreatic β cell ferroptosis through regulation of the GPX4/ACSL4 axis

Ferroptosis, a new type of cell death, is associated with pancreatic β cell damage. However, the role of glucolipotoxicity in inducing β cell ferroptosis remains unclear. Metformin (Met), exenatide (Exe), and saxagliptin (Sax) are frequently used anti-hyperglycaemic drugs. However, their protective effects on β cells through ferroptosis modulation are not well-established. In this study, we observed significant ferroptosis in NIT-1 cells and primary mouse islets after exposure to high glucose and palmitate (HG/PA). Compared to Exe and Sax, Met significantly alleviated glucolipotoxicity-induced pancreatic β cell ferroptosis. Blocking the activity of glutathione peroxidase 4 (GPX4) with Ras-selective lethal 3 or inhibiting its expression by small interfering RNA transfection significantly attenuated the anti-ferroptosis effects of Met. Mechanistically, Met alleviates HG/PA-induced β cell ferroptosis by regulating the GPX4/ACSL4 axis. Collectively, our findings highlight the significance of ferroptosis in pancreatic β cell glucolipotoxicity-induced injury and provide novel insights into the protective effects of Met on islet β cells.

Identifying Ferroptosis-Related Genes Associated with Weight Loss Outcomes and Regulation of Adipocyte Microenvironment

SCOPE

The study is about the influence of ferroptosis-related genes combined with the immune microenvironment exerted on weight control outcomes and systematic analysis.

METHODS AND RESULTS

Subcutaneous adipose tissue (sWAT) samples from 11 subjects with good outcome and 10 subjects with poor outcome in weight management are obtained from the Gene Expression Omnibus database. The results are validated in vivo in animal models with different weight loss outcomes. The CIBERSORT algorithm is used to evaluate the differences in immune cell infiltration in each sample. Patients with poor outcome have higher levels of ferroptosis in the adipose tissue. Remarkable differences in cytokine production, nuclear factor kappa-B(NF-κB) transcription factor activity, leukocyte migration involved in the inflammatory response, and other biological processes are also observed compared to that in the well-controlled group. Aldo-keto reductase family 1-member C1(AKR1C1), nuclear receptor coactivator 4(NCOA4), and glutamate-cysteine ligase catalytic subunit(GCLC) are identified as core predictive markers and their expression patterns are confirmed in animal models.

CONCLUSIONS

Ferroptosis and its mediated inflammation play an important role in long-term weight control, and analyses of the role of ferroptosis-related genes(FRGs) in weight control may provide new potential therapeutic targets for long-term weight control. Anti-inflammatory diets that mitigate inflammatory responses and affect ferroptosis may be considered in the future to improve weight control.

The suppression of hyperlipid diet-induced ferroptosis of vascular smooth muscle cells protests against atherosclerosis independent of p53/SCL7A11/GPX4 axis

Ferroptosis as a novel programmed cell death that involves metabolic dysfunction due to iron-dependent excessive lipid peroxidation has been implicated in atherosclerosis (AS) development characterized by disrupted lipid metabolism, but the atherogenic role of ferroptosis in vascular smooth muscle cells (VSMCs), which are principal components of atherosclerotic plaque fibrous cap, remains unclear. The aim of this study was to determine the effects of ferroptosis on AS induced by lipid overload, and the effects of that on VSMCs ferroptosis. We found intraperitoneal injection of Fer-1, a ferroptosis inhibitor, ameliorated obviously high-fat diet-induced high plasma levels of triglycerides, total cholesterol, low-density lipoprotein, glucose and atherosclerotic lesions in ApoE-/- mice. Moreover, in vivo and in vitro, Fer-1 reduced the iron accumulation of atherosclerotic lesions through affecting the expression of TFR1, FTH, and FTL in VSMCs. Interestingly, Fer-1 did augment nuclear factor E2-related factor 2/ferroptosis suppressor protein 1 to enhance endogenous resistance to lipid peroxidation, but not classic p53/SCL7A11/GPX4. Those observations indicated inhibition of VSMCs ferroptosis can improve AS lesions independent of p53/SLC7A11/GPX4, which preliminarily revealed the potential mechanism of ferroptosis in aortic VSMCs on AS and provided new therapeutic strategies and targets for AS.

Silibinin alleviates ferroptosis of rat islet β cell INS-1 induced by the treatment with palmitic acid and high glucose through enhancing PINK1/parkin-mediated mitophagy

Type 2 diabetes (T2DM) is induced by the abundance of glucose and lipids, which causes glucolipotoxicity to the pancreatic β-cells. Silibinin is a natural flavonoid possessing the regulatory activity on insulin production and therapeutic activity in diabetic mice; however, its effect on glucolipotoxicity is not fully explained. This in vitro study investigates the effects of silibinin on palmitic acid (PA) and high glucose (HG)-induced cell loss and ferroptosis of rat insulinoma INS-1 cells. In the cells treated with PA and HG, expressions of glucose transporter 4 (Glut4) and carnitine acyltransferase I (CPT1) for β-oxidation of fatty acids are reduced. Mitochondria are the metabolic organelles for glucose and fatty acids. The mitochondrial membrane potential (MMP) and ATP production were decreased, while the ROS level was elevated in the cells treated with PA and HG, indicating an induction of mitochondrial disorder. Cell loss was partially rescued by ferroptosis inhibition, suggesting an involvement of ferroptosis in the cells treated with PA and HG. More importantly, the increases in total iron, lipid ROS, MDA and COX-2, and the decrease in ferroptosis inhibitory molecules GSH, GPX4 and FSP1 appeared in the cells treated with PA and HG, confirming the occurrence of ferroptosis. Moreover, PINK1/parkin-mediated mitophagy, a vital process for selective elimination of damaged mitochondria, was blocked. Interestingly, silibinin rescued the mitochondria, restricted the ferroptosis and restored the mitophagy. By using the pharmacological stimulator and inhibitor of mitophagy, and si-RNA transfection to silence PINK1 expression, silibinin's protective effect against ferroptosis caused by PA and HG treatment was found to depend on mitophagy. Collectively, our current study reveals the new mechanisms for the protection of silibinin against the injury of INS-1 cells treated with PA and HG, elucidates the participation of ferroptosis in glucolipotoxicity, highlighting the involvement of mitophagy in defense against ferroptotic cell death.

Defense systems to avoid ferroptosis caused by lipid peroxidation-mediated membrane damage

The presence of hydrogen peroxide along with ferrous iron produces hydroxyl radicals that preferably oxidize polyunsaturated fatty acids (PUFA) to alkyl radicals (L•). The reaction of L• with an oxygen molecule produces lipid peroxyl radical (LOO•) that collectively trigger chain reactions, which results in the accumulation of lipid peroxidation products (LOOH). Oxygenase enzymes, such as lipoxygenase, also stimulate the peroxidation of PUFA. The production of phospholipid hydroperoxides (P-LOOH) can result in the destruction of the architecture of cell membranes and ultimate cell death. This iron-dependent regulated cell death is generally referred to as ferroptosis. Radical scavengers, which include tocopherol and nitric oxide (•NO), react with lipid radicals and terminate the chain reaction. When tocopherol reductively detoxifies lipid radicals, the resultant tocopherol radicals are recycled via reduction by coenzyme Q or ascorbate. CoQ radicals are reduced back by the anti-ferroptotic enzyme FSP1. •NO reacts with lipid radicals and produces less reactive nitroso compounds. The resulting P-LOOH is reductively detoxified by the action of glutathione peroxidase 4 (GPX4) or peroxiredoxin 6 (PRDX6). The hydrolytic removal of LOOH from P-LOOH by calcium-independent phospholipase A2 leads the preservation of membrane structure. While the expression of such protective genes or the presence of these anti-oxidant compounds serve to maintain a healthy condition, tumor cells employ them to make themselves resistant to anti-tumor treatments. Thus, these defense mechanisms against ferroptosis are protective in ordinary cells but are also potential targets for cancer treatment.

Critical Roles of the Cysteine-Glutathione Axis in the Production of γ-Glutamyl Peptides in the Nervous System

γ-Glutamyl moiety that is attached to the cysteine (Cys) residue in glutathione (GSH) protects it from peptidase-mediated degradation. The sulfhydryl group of the Cys residue represents most of the functions of GSH, which include electron donation to peroxidases, protection of reactive sulfhydryl in proteins via glutaredoxin, and glutathione conjugation of xenobiotics, whereas Cys-derived sulfur is also a pivotal component of some redox-responsive molecules. The amount of Cys that is available tends to restrict the capacity of GSH synthesis. In in vitro systems, cystine is the major form in the extracellular milieu, and a specific cystine transporter, xCT, is essential for survival in most lines of cells and in many primary cultivated cells as well. A reduction in the supply of Cys causes GPX4 to be inhibited due to insufficient GSH synthesis, which leads to iron-dependent necrotic cell death, ferroptosis. Cells generally cannot take up GSH without the removal of γ-glutamyl moiety by γ-glutamyl transferase (GGT) on the cell surface. Meanwhile, the Cys-GSH axis is essentially common to certain types of cells; primarily, neuronal cells that contain a unique metabolic system for intercellular communication concerning γ-glutamyl peptides. After a general description of metabolic processes concerning the Cys-GSH axis, we provide an overview and discuss the significance of GSH-related compounds in the nervous system.

Signaling pathways in vascular function and hypertension: molecular mechanisms and therapeutic interventions

Hypertension is a global public health issue and the leading cause of premature death in humans. Despite more than a century of research, hypertension remains difficult to cure due to its complex mechanisms involving multiple interactive factors and our limited understanding of it. Hypertension is a condition that is named after its clinical features. Vascular function is a factor that affects blood pressure directly, and it is a main strategy for clinically controlling BP to regulate constriction/relaxation function of blood vessels. Vascular elasticity, caliber, and reactivity are all characteristic indicators reflecting vascular function. Blood vessels are composed of three distinct layers, out of which the endothelial cells in intima and the smooth muscle cells in media are the main performers of vascular function. The alterations in signaling pathways in these cells are the key molecular mechanisms underlying vascular dysfunction and hypertension development. In this manuscript, we will comprehensively review the signaling pathways involved in vascular function regulation and hypertension progression, including calcium pathway, NO-NOsGC-cGMP pathway, various vascular remodeling pathways and some important upstream pathways such as renin-angiotensin-aldosterone system, oxidative stress-related signaling pathway, immunity/inflammation pathway, etc. Meanwhile, we will also summarize the treatment methods of hypertension that targets vascular function regulation and discuss the possibility of these signaling pathways being applied to clinical work.