Caveolin-1 Alleviates Diabetes-Associated Cognitive Dysfunction Through Modulating Neuronal Ferroptosis-Mediated Mitochondrial Homeostasis

Targeting ferroptosis in the neurovascular unit: A promising approach for treating diabetic cognitive impairment

The cognitive decline associated with chronic metabolic disease diabetes has garnered extensive scrutiny, yet its pathogenesis remains incompletely understood, and the advancement of targeted therapeutics has posed a persistent challenge. Ferroptosis, a novel form of cell death characterized by intracellular lipid peroxidation and iron overload, has recently emerged as a significant factor. Numerous contemporary studies have corroborated that ferroptosis within the neurovascular unit is intimately associated with the onset of diabetes-induced cognitive impairment. Numerous contemporary studies have corroborated that ferroptosis within the neurovascular unit is intimately associated with the onset of diabetic cognitive impairment (DCI). This article initially conducts a profound analysis of the mechanism of ferroptosis, followed by a detailed elucidation of the specific manifestations of neurovascular unit ferroptosis in the context of diabetic cognitive function impairment. Furthermore, an exhaustive review of pertinent literature from April 2020 to March 2024 has been undertaken, resulting in the selection of 31 documents of significant reference value. These documents encompass studies on 11 distinct drugs, all of which are centered around investigating methods to inhibit the ferroptosis pathway as a potential treatment for DCI. Simultaneously, we conducted a review of 12 supplementary literary sources that presented 10 pharmacological agents with anti-ferroptosis properties in other neurodegenerative disorders. This article critically examines the potential influence of neurovascular unit ferroptosis on the progression of cognitive impairment in diabetes, from the three aforementioned perspectives, and organizes the existing and potential therapeutic drugs. It is our aspiration that this article will serve as a theoretical foundation for scholars in related disciplines when conceptualizing, investigating, and developing novel clinical drugs for DCI.

Predicting the Risk of Postoperative Delirium in Elderly Patients Undergoing Hip Arthroplasty: Development and Assessment of a Novel Nomogram

OBJECTIVE

To construct and internally validate a nomogram that predicts the likelihood of postoperative delirium in a cohort of elderly individuals undergoing hip arthroplasty.

METHODS

Data for a total of 681 elderly patients underwent hip arthroplasty were retrospectively collected and divided into a model (n = 477) and a validation cohort (n = 204) according to the principle of 7:3 distribution temporally. The assessment of postoperative cognitive function was conducted through the utilization of The Confusion Assessment Method (CAM). The nomogram model for postoperative cognitive impairments was established by a combination of Lasso regression and logistic regression. The receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA) were used to evaluate the performance.

RESULTS

The nomogram utilized various predictors, including age, body mass index (BMI), education, preoperative Barthel Index, preoperative hemoglobin level, history of diabetes, and history of cerebrovascular disease, to forecast the likelihood of postoperative delirium in patients. The area under the ROC curves (AUC) for the nomogram, incorporating the aforementioned predictors, was 0.836 (95% CI: 0.797-0.875) for the training set and 0.817 (95% CI: 0.755-0.880) for the validation set. The calibration curves for both sets indicated a good agreement between the nomogram's predictions and the actual probabilities.

CONCLUSION

The use of this novel nomogram can help clinicians predict the likelihood of delirium after hip arthroplasty in elderly patients and help prevent and manage it in advance.

TREM1 induces microglial ferroptosis through the PERK pathway in diabetic-associated cognitive impairment

Ferroptosis is involved in neurodegenerative disorders including diabetes-associated cognitive impairment (DACI). As central immune cells, microglia have strong siderophilic properties. However, the role of iron deposition in microglia and the underlying regulatory mechanism remains unclear in DACI. Here, we established high glucose (HG) model in BV2/HMC3 cells and diabetes model in C57BL/6 J mice with HFD and STZ. Transmission Electron Microscopy, Western blot, assay kits of Fe2+, GSH/GSSG, MDA and ROS were carried out in vitro. Prussian blue staining, Western blot and immunofluorescence were implemented in vivo. Y-maze and novel object recognition were performed to assess cognitive performance. LP17 was used to inhibit TREM1 (triggering receptor expressed on myeloid cells 1) specifically in vivo and vitro. We found excessively deposited iron and significant reduction in antioxidants in hippocampal microglia of mice with DACI, concomitant with increased TREM1 (a microglia-specific inflammatory amplifier). Furthermore, LP17 (TREM1 specific inhibitor) ameliorated cognitive impairment caused by HFD/STZ through relieving iron accumulation and antioxidant inactivation. In vitro, ferroptosis was induced by HG in mice microglia-BV2 and human microglia-HMC3 cells, which could be blocked by a ferroptosis inhibitor-Fer-1 and LP17. Moreover, PERK pathway of endoplasmic reticulum stress was activated by HG, and then reversed by PERK inhibitor GSK2606414 and LP17 followed by improved ferroptosis in HG-cultured BV2. In summary, our results indicated that TREM1 effectively aggravates T2DM-associated microglial iron accumulation through the PERK pathway of ERS, which contributes to antioxidant inactivation and lipid peroxidation, eventually, massively boosted ROS result in microglial ferroptosis. The mechanism elucidation in our study may shed light on targeted therapy of DACI.

Mechanistic Insights and Potential Therapeutic Implications of NRF2 in Diabetic Encephalopathy

Diabetic encephalopathy (DE) is a complication of diabetes, especially type 2 diabetes (T2D), characterized by damage in the central nervous system and cognitive impairment, which has gained global attention. Despite the extensive research aimed at enhancing our understanding of DE, the underlying mechanism of occurrence and development of DE has not been established. Mounting evidence has demonstrated a close correlation between DE and various factors, such as Alzheimer's disease-like pathological changes, insulin resistance, inflammation, and oxidative stress. Of interest, nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor with antioxidant properties that is crucial in maintaining redox homeostasis and regulating inflammatory responses. The activation and regulatory mechanisms of NRF2 are a relatively complex process. NRF2 is involved in the regulation of multiple metabolic pathways and confers neuroprotective functions. Multiple studies have provided evidence demonstrating the significant involvement of NRF2 as a critical transcription factor in the progression of DE. Additionally, various molecules capable of activating NRF2 expression have shown potential in ameliorating DE. Therefore, it is intriguing to consider NRF2 as a potential target for the treatment of DE. In this review, we aim to shed light on the role and the possible underlying mechanism of NRF2 in DE. Furthermore, we provide an overview of the current research landscape and address the challenges associated with using NRF2 activators as potential treatment options for DE.

The role of ferroptosis in DM-induced liver injury

The liver damage caused by Diabetes Mellitus (DM) has attracted increasing attention in recent years. Liver injury in DM can be caused by ferroptosis, a form of cell death caused by iron overload. However, the role of iron transporters in this context is still not clear. Herein, we attempted to shed light on the pathophysiological mechanism of ferroptosis. DM was induced in 8-week-old male rats by streptozotocin (STZ) before assessment of the degree of liver injury. Together with histopathological changes, variations in glutathione peroxidase 4 (GPX4), glutathione (GSH), superoxide dismutase (SOD), transferrin receptor 1 (TFR1), ferritin heavy chain (FTH), ferritin light chain (FTL), ferroportin and Prussian blue staining, were monitored in rat livers before and after treatment with Fer-1. In the liver of STZ-treated rats, GSH and SOD levels decreased, whereas those of malondialdehyde (MDA) increased. Expression of TFR1, FTH and FTL increased whereas that of glutathione peroxidase 4 (GPX4) and ferroportin did not change significantly. Prussian blue staining showed that iron levels increased. Histopathology showed liver fibrosis and decreased glycogen content. Fer-1 treatment reduced iron and MDA levels but GSH and SOD levels were unchanged. Expression of FTH and FTL was reduced whereas that of ferroportin showed a mild decrease. Fer-1 treatment alleviated liver fibrosis, increased glycogen content and mildly improved liver function. Our study demonstrates that ferroptosis is involved in DM-induced liver injury. Regulating the levels of iron transporters may become a new therapeutic strategy in ferroptosis-induced liver injury.

Propofol ameliorates cognitive deficits following splenectomy in aged rats by inhibiting ferroptosis via the SIRT1/Nrf2/GPX4 pathway

The aim of this study was to investigate the mechanism by which propofol reduces postoperative cognitive dysfunction after splenectomy in aged rats. The rats in the model group and propofol group were subjected to splenectomy, and anesthetized with isoflurane and propofol, respectively. Utilizing the western blotting to assess the expression of sirtuin-1 (SIRT1) in the hippocampus. Molecular docking technology was used to predict the binding ability of propofol and SIRT1. Behavioral tests were performed using the Morris water maze, and the hippocampus was isolated for mechanistic investigations. Molecular docking showed that propofol and SIRT1 had a strong binding affinity. The expression of SIRT1 and its related proteins Nrf2, HO-1, NQO1, and GPX4 in the model rats was decreased compared with the sham group. Moreover, the model group exhibited cognitive decline, such as extended escape latency and decreased number of platform crossings. Pathological analysis showed that the number of apoptotic neurons, the levels of oxidative stress and neuroinflammation, the iron deposition, and the expressions of ACSL4 and TFR1 were increased, while the expressions of SLC7A11 and FTH1 were decreased in the hippocampal CA1 region within the model group. These pathological changes in the propofol group were, however, less than those in the model group. Nevertheless, the SIRT1 inhibitor increased these pathological changes compared with the propofol group. Compared with isoflurane, propofol inhibits ferroptosis in the hippocampus of splenectomized rats by causing less downregulation of the SIRT1/Nrf2/GPX4 pathway, thereby reducing the negative impact on cognitive function.

Caveolae with GLP-1 and NMDA Receptors as Crossfire Points for the Innovative Treatment of Cognitive Dysfunction Associated with Neurodegenerative Diseases

Some neurodegenerative diseases may be characterized by continuing behavioral and cognitive dysfunction that encompasses memory loss and/or apathy. Alzheimer's disease is the most typical type of such neurodegenerative diseases that are characterized by deficits of cognition and alterations of behavior. Despite the huge efforts against Alzheimer's disease, there has yet been no successful treatment for this disease. Interestingly, several possible risk genes for cognitive dysfunction are frequently expressed within brain cells, which may also be linked to cholesterol metabolism, lipid transport, exosomes, and/or caveolae formation, suggesting that caveolae may be a therapeutic target for cognitive dysfunctions. Interestingly, the modulation of autophagy/mitophagy with the alteration of glucagon-like peptide-1 (GLP-1) and N-methyl-d-aspartate (NMDA) receptor signaling may offer a novel approach to preventing and alleviating cognitive dysfunction. A paradigm showing that both GLP-1 and NMDA receptors at caveolae sites may be promising and crucial targets for the treatment of cognitive dysfunctions has been presented here, which may also be able to modify the progression of Alzheimer's disease. This research direction may create the potential to move clinical care toward disease-modifying treatment strategies with maximal benefits for patients without detrimental adverse events for neurodegenerative diseases.

Baicalein: A potential GLP-1R agonist improves cognitive disorder of diabetes through mitophagy enhancement

There is increasing evidence that the activation of glucagon-like peptide-1 receptor (GLP-1R) can be used as a therapeutic intervention for cognitive disorders. Here, we have screened GLP-1R targeted compounds from Scutellaria baicalensis, which revealed baicalein is a potential GLP-1R small-molecule agonist. Mitophagy, a selective autophagy pathway for mitochondrial quality control, plays a neuroprotective role in multiple cognitive impairment diseases. We noticed that Glp1r knock-out (KO) mice present cognitive impairment symptoms and appear worse in spatial learning memory and learning capacity in Morris water maze (MWM) test than their wide-type (WT) counterparts. Our mechanistic studies revealed that mitophagy is impaired in hippocampus tissue of diabetic mice and Glp1r KO mice. Finally, we verified that the cognitive improvement effects of baicalein on diabetic cognitive dysfunction occur through the enhancement of mitophagy in a GLP-1R-dependent manner. Our findings shed light on the importance of GLP-1R for cognitive function maintenance, and revealed the vital significance of GLP-1R for maintaining mitochondrial homeostasis. Furthermore, we identified the therapeutic potential of baicalein in the treatment of cognitive disorder associated with diabetes.

MVP enhances FGF21-induced ferroptosis in hepatocellular carcinoma by increasing lipid peroxidation through regulation of NOX4

Ferroptosis is a novel, iron-dependent regulatory cell death mainly caused by an imbalance between the production and degradation of intracellular reactive oxygen species (ROS). Recently, ferroptosis induction has been considered a potential therapeutic approach for hepatocellular carcinoma (HCC). Fibroblast growth factor 21 (FGF21) is a new modulator of ferroptosis; however, the regulatory role of FGF21 in HCC ferroptosis has not been investigated. In this study, we explored the role of FGF21 and its underlying molecular mechanism in the ferroptotic death of HCC cells. We identified Major vault protein (MVP) as a target of FGF21 and revealed that knockdown of MVP inhibited the lipid peroxidation levels of HCC cells by decreasing NADPH oxidase 4 (NOX4, a major source of ROS) transcription, thereby attenuating the effect of FGF21-mediated ferroptosis. On the other hand, MVP overexpression showed the opposite results. Mechanistically, MVP binds to IRF1 and thus interferes with the interaction between IRF1 and the YAP1 promoter, leading to an increase in NOX4 transcription. Importantly, forced expression of IRF1 or downregulation of YAP1 partially reversed the effect of MVP overexpression on HCC ferroptosis. Furthermore, the results in xenograft tumor models suggested that overexpression of MVP can efficiently increase the level of lipid peroxidation in vivo. Taken together, these results provide new insights into the regulatory mechanism of ferroptosis in HCC.

Exerkine FNDC5/irisin-enriched exosomes promote proliferation and inhibit ferroptosis of osteoblasts through interaction with Caveolin-1

Postmenopausal osteoporosis is a prevalent metabolic bone disorder characterized by a decrease in bone mineral density and deterioration of bone microstructure. Despite the high prevalence of this disease, no effective treatment for osteoporosis has been developed. Exercise has long been considered a potent anabolic factor that promotes bone mass via upregulation of myokines secreted by skeletal muscle, exerting long-term osteoprotective effects and few side effects. Irisin was recently identified as a novel myokine that is significantly upregulated by exercise and could increase bone mass. However, the mechanisms underlying exercise-induced muscle-bone crosstalk remain unclear. Here, we identified that polyunsaturated fatty acids (arachidonic acid and docosahexaenoic acid) are increased in skeletal muscles following a 10-week treadmill exercise programme, which then promotes the expression and release of FNDC5/irisin. In osteoblasts, irisin binds directly to Cav1, which recruits and interacts with AMP-activated protein kinase α (AMPKα) to activate the AMPK pathway. Nrf2 is the downstream target of the AMPK pathway and increases the transcription of HMOX1 and Fpn. HMOX1 is involved in regulating the cell cycle and promotes the proliferation of osteoblasts. Moreover, upregulation of Fpn in osteoblasts enhanced iron removal, thereby suppressing ferroptosis in osteoblasts. Additionally, we confirmed that myotube-derived exosomes are involved in the transportation of irisin and enter osteoblasts through caveolae-mediated endocytosis. In conclusion, our findings highlight the crucial role of irisin, present in myotube-derived exosomes, as a crucial regulator of exercise-induced protective effects on bone, which provides novel insights into the mechanisms underlying exercise-dependent treatment of osteoporosis.

Iron Chelator Deferiprone Restores Iron Homeostasis and Inhibits Retinal Neovascularization in Experimental Neovascular Age-Related Macular Degeneration

Purpose

Retinal neovascularization is a significant feature of advanced age-related macular degeneration (AMD) and a major cause of blindness in patients with AMD. However, the underlying mechanism of this pathological neovascularization remains unknown. Iron metabolism has been implicated in various biological processes. This study was conducted to investigate the effects of iron metabolism on retinal neovascularization in neovascular AMD (nAMD).

Methods

C57BL/6J and very low-density lipoprotein receptor (VLDLR) knockout (Vldlr-/-) mice, a murine model of nAMD, were used in this study. Bulk-RNA sequencing was used to identify differentially expressed genes. Western blot analysis was performed to test the expression of proteins. Iron chelator deferiprone (DFP) was administrated to the mice by oral gavage. Fundus fluorescein angiography was used to evaluate retinal vascular leakage. Immunofluorescence staining was used to detect macrophages and iron-related proteins.

Results

RNA sequencing (RNA-seq) results showed altered transferrin expression in the retina and RPE of Vldlr-/- mice. Disrupted iron homeostasis was observed in the retina and RPE of Vldlr-/- mice. DFP mitigated iron overload and significantly reduced retinal neovascularization and vascular leakage. In addition, DFP suppressed the inflammation in Vldlr-/- retinas. The reduced signals of macrophages were observed at sites of neovascularization in the retina and RPE of Vldlr-/- mice after DFP treatment. Further, the IL-6/JAK2/STAT3 signaling pathway was activated in the retina and RPE of Vldlr-/- mice and reversed by DFP treatment.

Conclusions

Disrupted iron metabolism may contribute to retinal neovascularization in nAMD. Restoring iron homeostasis by DFP could be a potential therapeutic approach for nAMD.

Different Types of Cell Death in Diabetic Neuropathy: A Focus on Mechanisms and Therapeutic Strategies

Diabetic neuropathy (DN) is a common complication of diabetes, affecting over 50% of patients, leading to significant pain and a burden. Currently, there are no effective treatments available. Cell death is considered a key factor in promoting the progression of DN. This article reviews how cell death is initiated in DN, emphasizing the critical roles of oxidative stress, mitochondrial dysfunction, inflammation, endoplasmic reticulum stress, and autophagy. Additionally, we thoroughly summarize the mechanisms of cell death that may be involved in the pathogenesis of DN, including apoptosis, autophagy, pyroptosis, and ferroptosis, among others, as well as potential therapeutic targets offered by these death mechanisms. This provides potential pathways for the prevention and treatment of diabetic neuropathy in the future.

STZ-induced diabetes exacerbates neurons ferroptosis after ischemic stroke by upregulating LCN2 in neutrophils

Diabetic is a major contributor to the unfavorable prognosis of ischemic stroke. However, intensive hypoglycemic strategies do not improve stroke outcomes, implying that diabetes may affect stroke outcomes through other ways. Ferroptosis is a novel programmed cell death pathway associated with the development of diabetes and ischemic stroke. This study aimed to investigate the effect of streptozotocin (STZ)-induced diabetes on ferroptosis after stroke from the immune cell perspective, and to provide a theoretical foundation for the clinical management of ischemic stroke in patients with diabetes. The results revealed that STZ-induced diabetes not only facilitates the infiltration of neutrophils into the brain after stroke, but also upregulates the expression of lipocalin 2 (LCN2) in neutrophils. LCN2 promotes lipid peroxide accumulation by increasing intracellular ferrous ions, which intensify ferroptosis in major brain cell populations, especially neurons. Our findings suggest that STZ-induced diabetes aggravates ischemic stroke partially by mediating ferroptosis through neutrophil-derived LCN2. These data contribute to improved understanding of post-stroke immune regulation in diabetes, and offer a potentially novel therapeutic target for the management of acute-stage ischemic stroke complicated with diabetes.

Zedoarondiol inhibits human bronchial smooth muscle cell proliferation through the CAV-1/PDGF signalling pathway

Airway remodelling in lung diseases can be treated by inhibiting excessive smooth muscle cell proliferation. Zedoarondiol (Zed) is a natural compound isolated from the Chinese herb Curcuma longa. The caveolin-1 (CAV-1) is widely expressed in lung cells and plays a key role in platelet-derived growth factor (PDGF) signalling and cell proliferation. This study aims to investigate the effect of Zed on human bronchial smooth muscle cell (HBSMC) proliferation and explore its potential molecular mechanisms. We assessed the effect of Zed on the proliferation of PDGF-stimulated HBSMCs and performed proteomic analysis to identify potential molecular targets and pathways. CAV1 siRNA was used to validate our findings in vitro. In PDGF-stimulated HBSMCs, Zed significantly inhibited excessive proliferation of HBSMCs. Proteomic analysis of zedoarondiol-treated HBSMCs revealed significant enrichment of differentially expressed proteins in cell proliferation-related pathways and biological processes. Zed inhibition of HBSMC proliferation was associated with upregulation of CAV1, regulation of the CAV-1/PDGF pathway and inhibition of MAPK and PI3K/AKT signalling pathway activation. Treatment of HBSMCs with CAV1 siRNA partly reversed the inhibitory effect of Zed on HBSMC proliferation. Thus, this study reveals that zedoarondiol potently inhibits HBSMC proliferation by upregulating CAV-1 expression, highlighting its potential value in airway remodelling and related diseases.

Diabetes and vascular mild cognitive impairment among Chinese ≥50 years: A cross-sectional study with 2020 participants

BACKGROUND

With the decline of cognitive function in vascular cognitive impairment, the burden on the family and society will increase. Therefore, early identification of vascular mild cognitive impairment (VaMCI) is crucial. The focus of early identification of VaMCI is on the attention of risk factors. Therefore, this study aimed to investigate the relationship between diabetes and VaMCI among the Chinese, hoping to predict the risk of VaMCI by diabetes and to move the identification of vascular cognitive impairment forward.

METHODS

We collected data from seven clinical centers and nine communities in China. All participants were over 50 years of age and had cognitive complaints. We collected basic information of the participants, and cognitive function was professionally assessed by the Montreal Cognitive Assessment scale. Finally, logistic regression analysis was used to analyze the correlation between each factor and VaMCI.

RESULTS

A total of 2020 participants were included, including 1140 participants with VaMCI and 880 participants with normal cognition. In univariate logistic regression analysis, age, heavy smoking, and diabetes had a positive correlation with VaMCI. At the same time, being married, high education, and light smoking had a negative correlation with VaMCI. After correction, only diabetes (OR = 1.04, 95% CI: 1.01-1.09, p = 0.05) had a positive correlation with VaMCI, and high education (OR = 0.60, 95% CI:.45-.81, p = 0.001) had a negative correlation with VaMCI.

CONCLUSION

In our study, we found that diabetes had a positive correlation with VaMCI, and high education had a negative correlation with VaMCI. Therefore, early identification and timely intervention of diabetes may reduce the risk of VaMCI and achieve early prevention of VaMCI.

A mechanism linking ferroptosis and ferritinophagy in melatonin-related improvement of diabetic brain injury

Ferroptosis and ferritinophagy play critical roles in various disease contexts. Herein, we observed that ferroptosis and ferritinophagy were induced both in the brains of mice with diabetes mellitus (DM) and neuronal cells after high glucose (HG) treatment, as evidenced by decreases in GPX4, SLC7A11, and ferritin levels, but increases in NCOA4 levels. Interestingly, melatonin administration ameliorated neuronal damage by inhibiting ferroptosis and ferritinophagy both in vivo and in vitro. At the molecular level, we found that not only the ferroptosis inducer p53 but also the ferritinophagy mediator NCOA4 was the potential target of miR-214-3p, which was downregulated by DM status or HG insult, but was increased after melatonin treatment. However, the inhibitory effects of melatonin on ferroptosis and ferritinophagy were blocked by miR-214-3p downregulation. These findings suggest that melatonin is a potential drug for improving diabetic brain damage by inhibiting p53-mediated ferroptosis and NCOA4-mediated ferritinophagy through regulating miR-214-3p in neurons.

Artemisinin ameliorates cognitive decline by inhibiting hippocampal neuronal ferroptosis via Nrf2 activation in T2DM mice

BACKGROUND

Neuronal ferroptosis plays a critical role in the pathogenesis of cognitive deficits. The present study explored whether artemisinin protected type 2 diabetes mellitus (T2DM) mice from cognitive impairments by attenuating neuronal ferroptosis in the hippocampal CA1 region.

METHODS

STZ-induced T2DM mice were treated with artemisinin (40 mg/kg, i.p.), or cotreated with artemisinin and Nrf2 inhibitor MEL385 or ferroptosis inducer erastin for 4 weeks. Cognitive performance was determined by the Morris water maze and Y maze tests. Hippocampal ROS, MDA, GSH, and Fe2+ contents were detected by assay kits. Nrf2, p-Nrf2, HO-1, and GPX4 proteins in hippocampal CA1 were assessed by Western blotting. Hippocampal neuron injury and mitochondrial morphology were observed using H&E staining and a transmission electron microscope, respectively.

RESULTS

Artemisinin reversed diabetic cognitive impairments, decreased the concentrations of ROS, MDA and Fe2+, and increased the levels of p-Nr2, HO-1, GPX4 and GSH. Moreover, artemisinin alleviated neuronal loss and ferroptosis in the hippocampal CA1 region. However, these neuroprotective effects of artemisinin were abolished by Nrf2 inhibitor ML385 and ferroptosis inducer erastin.

CONCLUSION

Artemisinin effectively ameliorates neuropathological changes and learning and memory decline in T2DM mice; the underlying mechanism involves the activation of Nrf2 to inhibit neuronal ferroptosis in the hippocampus.

PANoptosis-related genes function as efficient prognostic biomarkers in colon adenocarcinoma

Background

PANoptosis is a newly discovered cell death type, and tightly associated with immune system activities. To date, the mechanism, regulation and application of PANoptosis in tumor is largely unknown. Our aim is to explore the prognostic value of PANoptosis-related genes in colon adenocarcinoma (COAD).

Methods

Analyzing data from The Cancer Genome Atlas-COAD (TCGA-COAD) involving 458 COAD cases, we concentrated on five PANoptosis pathways from the Molecular Signatures Database (MSigDB) and a comprehensive set of immune-related genes. Our approach involved identifying distinct genetic COAD subtype clusters and developing a prognostic model based on these parameters.

Results

The research successfully identified two genetic subtype clusters in COAD, marked by distinct profiles in PANoptosis pathways and immune-related gene expression. A prognostic model, incorporating these findings, demonstrated significant predictive power for survival outcomes, underscoring the interplay between PANoptosis and immune responses in COAD.

Conclusion

This study enhances our understanding of COAD's genetic framework, emphasizing the synergy between cell death pathways and the immune system. The development of a prognostic model based on these insights offers a promising tool for personalized treatment strategies. Future research should focus on validating and refining this model in clinical settings to optimize therapeutic interventions in COAD.

The Tao Hong Si Wu Decoction ameliorates diabetes-associated cognitive dysfunction by inhibiting the formation of amyloid plaques

OBJECTIVES

The herbs in Tao Hong Si Wu Decoction (THSWD) are beneficial in the treatment of cognitive impairment. However, the underlying mechanisms of THSWD in treating diabetes-associated cognitive dysfunction (DACD) are not entirely explored. This study is aimed to investigate the therapeutic effects of THSWD in DACD model rats and the underlying mechanism.

METHODS

Ultra-high-phase liquid chromatography was employed to identify the main compounds contained in the THSWD extract. DACD rat model was induced by feeding with a high-sugar and high-fat diet and injecting streptozotocin (35 mg/kg). DACD rats were gavaged with THSWD for 1 week. The learning and memory abilities of the rats were measured by using the Morris water maze. Western blotting was used to detect the changes in DACD rat targets. Statistical methods were used to evaluate the correlation between proteins.

RESULTS

The results show that THSWD effectively reduced the escape latency, hippocampal neuron damage, glycosylated hemoglobin, type A1C, and blood lipid levels in DACD rats. Furthermore, DACD rats showed significantly increased amyloid precursor protein, β-secretase, Aβ1-40 , Aβ1-42 , Tau phosphorylation, and advanced glycation end products (AGEs) expression. However, THSWD treatment can reverse this phenomenon.

CONCLUSIONS

THSWD can improve the learning and memory abilities of DACD rats by inhibiting the expression of AEGs-AGE receptors pathway, which provides an experimental basis for the clinical application of THSWD. In addition, the experiment combines pharmacological and statistical methods, which offers a new perspective for the study of Chinese herbal medicine.

Ferroptosis: Mechanisms and role in diabetes mellitus and its complications

Diabetes mellitus (DM) and its complications are major diseases that affect human health and pose a serious threat to global public health. Although the prevention and treatment of DM and its complications are constantly being revised, optimal treatment strategies remain unavailable. Further exploration of new anti-diabetic strategies is an arduous task. Revealing the pathological changes and molecular mechanisms of DM and its complications is the cornerstone for exploring new therapeutic strategies. Ferroptosis is a type of newly discovered iron-dependent regulated cell death. Notably, the role of ferroptosis in the occurrence, development, and pathogenesis of DM and its complications has gradually been revealed. Numerous studies have shown that ferroptosis plays an important role in the pathophysiology and pathogenesis of DM and its associated complications. The aim of this review is to discuss the known underlying mechanisms of ferroptosis, the relationship between ferroptosis and DM, and the relationship between ferroptosis as a mode of cell death and diabetic kidney disease, diabetic retinopathy, diabetic cardiomyopathy, diabetic osteoporosis, diabetes-associated cognitive dysfunction, DM-induced erectile dysfunction, and diabetic atherosclerosis.

Identification and validation of ferroptosis-related genes for diabetic retinopathy

Diabetic retinopathy (DR) is a leading cause of blindness, and ferroptosis may be an essential component of the pathological process of DR. In this study, we aimed to screen five hub genes (TLR4, CAV1, HMOX1, TP53, and IL-1B) using bioinformatics analysis and experimentally verify their expression and effects on ferroptosis and cell function. The online Gene Expression Omnibus microarray expression profiling datasets GSE60436 and GSE1025485 were selected for investigation. Ferroptosis-related genes that might be differentially expressed in DR were identified. Then, Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and protein-protein interaction (PPI) network analyses were conducted to characterize the differentially-expressed ferroptosis-related genes. After tissue-specific analyses and external dataset validation of hub genes, the mRNA and protein levels of hub genes in retinal microvascular endothelial cells (HRMECs) symbiotic with high glucose were verified using real-time quantitative PCR (qRT-PCR) and immunocytochemistry (ICC). Finally, hub genes were knocked down using siRNA, and changes in ferroptosis and cell function were observed. Based on the differential expression analysis, 19 ferroptosis-related genes were identified. GO and KEGG enrichment analyses showed that ferroptosis-related genes were significantly enriched in reactive oxygen species metabolic processes, necrotic cell death, hypoxia responses, iron ion responses, positive regulation of cell migration involved in sprouting angiogenesis, NF-kappa B signaling pathway, ferroptosis, fluid shear stress, and atherosclerosis. Subsequently, PPI network analysis and critical module construction were used to identify five hub genes. Based on bioinformatics analysis of mRNA microarrays, qRT-PCR confirmed higher mRNA expression of five genes in the DR model, and immunocytochemistry confirmed their higher protein expression. Finally, siRNA interference was used to verify the effects of five genes on ferroptosis and cell function. Based on bioinformatics analysis, five potential genes related to ferroptosis were identified, and their upregulation may affect the onset or progression of DR. This study sheds new light on the pathogenesis of DR.

Berberine attenuates cognitive dysfunction and hippocampal apoptosis in rats with prediabetes

The cognitive dysfunction caused by prediabetes causes great difficulties in human life, and the terrible thing is that the means to prevent the occurrence of this disease are very limited at present, Berberine has shown the potential to treat diabetes and cognitive dysfunction, but it still needs to be further explored to clarify the mechanism of its therapeutic effect. Therefore, the aim of this study was to investigate the effects and mechanisms of Berberine on prediabetes-induced cognitive dysfunction. Prediabetes rat model was induced by a high-fat diet and a normal diet was used as a control. They were fed for 20 weeks. At week 13, the model rats were given 100 mg/kg Berberine by gavage for 7 weeks. The cognitive function of rats was observed. At the same time, OGTT, fasting blood glucose, blood lipids, insulin and other metabolic parameters, oxidative stress, and apoptosis levels were measured. The results showed that the model rats showed obvious glucose intolerance, elevated blood lipids, and insulin resistance, and the levels of oxidative stress and apoptosis were significantly increased. However, after the administration of Berberine, the blood glucose and lipid metabolism of prediabetic rats were significantly improved, and the oxidative stress level and apoptosis level of hippocampal tissue were significantly reduced. In conclusion, Berberine can alleviate the further development of diabetes in prediabetic rats, reduce oxidative stress and apoptosis in hippocampal tissue, and improve cognitive impairment in prediabetic rats.

Neuron-targeted overexpression of caveolin-1 alleviates diabetes-associated cognitive dysfunction via regulating mitochondrial fission-mitophagy axis

BACKGROUND

Type 2 diabetes mellitus (T2DM) induced diabetes-associated cognitive dysfunction (DACD) that seriously affects the self-management of T2DM patients, is currently one of the most severe T2DM-associated complications, but the mechanistic basis remains unclear. Mitochondria are highly dynamic organelles, whose function refers to a broad spectrum of features such as mitochondrial dynamics, mitophagy and so on. Mitochondrial abnormalities have emerged as key determinants for cognitive function, the relationship between DACD and mitochondria is not well understood.

METHODS

Here, we explored the underlying mechanism of mitochondrial dysfunction of T2DM mice and HT22 cells treated with high glucose/palmitic acid (HG/Pal) focusing on the mitochondrial fission-mitophagy axis with drug injection, western blotting, Immunofluorescence, and electron microscopy. We further explored the potential role of caveolin-1 (cav-1) in T2DM induced mitochondrial dysfunction and synaptic alteration through viral transduction.

RESULTS

As previously reported, T2DM condition significantly prompted hippocampal mitochondrial fission, whereas mitophagy was blocked rather than increasing, which was accompanied by dysfunctional mitochondria and impaired neuronal function. By contrast, Mdivi-1 (mitochondrial division inhibitor) and urolithin A (mitophagy activator) ameliorated mitochondrial and neuronal function and thereafter lead to cognitive improvement by inhibiting excessive mitochondrial fission and giving rise to mitophagy, respectively. We have previously shown that cav-1 can significantly improve DACD by inhibiting ferroptosis. Here, we further demonstrated that cav-1 could not only inhibit mitochondrial fission via the interaction with GSK3β to modulate Drp1 pathway, but also rescue mitophagy through interacting with AMPK to activate PINK1/Parkin and ULK1-dependent signlings.

CONCLUSIONS

Overall, our data for the first time point to a mitochondrial fission-mitophagy axis as a driver of neuronal dysfunction in a phenotype that was exaggerated by T2DM, and the protective role of cav-1 in DACD. Graphic Summary Illustration. In T2DM, excessive mitochondrial fission and impaired mitophagy conspire to an altered mitochondrial morphology and mitochondrial dysfunction, with a consequent neuronal damage, overall suggesting an unbalanced mitochondrial fission-mitophagy axis. Upon cav-1 overexpression, GSK3β and AMPK are phosphorylated respectively to activate Drp1 and mitophagy-related pathways (PINK1 and ULKI), ultimately inhibits mitochondrial fission and enhances mitophagy. In the meantime, the mitochondrial morphology and neuronal function are rescued, indicating the protective role of cav-1 on mitochondrial fission-mitophagy axis. Video Abstract.

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.

Ketohexokinase-dependent metabolism of cerebral endogenous fructose in microglia drives diabetes-associated cognitive dysfunction

Dementia, as an advanced diabetes-associated cognitive dysfunction (DACD), has become the second leading cause of death among diabetes patients. Given that little guidance is currently available to address the DACD process, it is imperative to understand the underlying mechanisms and screen out specific therapeutic targets. The excessive endogenous fructose produced under high glucose conditions can lead to metabolic syndrome and peripheral organ damage. Although generated by the brain, the role of endogenous fructose in the exacerbation of cognitive dysfunction is still unclear. Here, we performed a comprehensive study on leptin receptor-deficient T2DM mice and their littermate m/m mice and revealed that 24-week-old db/db mice had cognitive dysfunction and excessive endogenous fructose metabolism in the hippocampus by multiomics analysis and further experimental validation. We found that the rate-limiting enzyme of fructose metabolism, ketohexokinase, is primarily localized in microglia. It is upregulated in the hippocampus of db/db mice, which enhances mitochondrial damage and reactive oxygen species production by promoting nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) expression and mitochondrial translocation. Inhibiting fructose metabolism via ketohexokinase depletion reduces microglial activation, leading to the restoration of mitochondrial homeostasis, recovery of structural synaptic plasticity, improvement of CA1 pyramidal neuron electrophysiology and alleviation of cognitive dysfunction. Our findings demonstrated that enhanced endogenous fructose metabolism in microglia plays a dominant role in diabetes-associated cognitive dysfunction and could become a potential target for DACD.

Integrated proteomics and metabolomics analysis of D-pinitol function during hippocampal damage in streptozocin-induced aging-accelerated mice

Purpose

Diabetes can cause hippocampal damage and lead to cognitive impairment. Diabetic cognitive impairment (DCI) is a chronic complication of diabetes associated with a high disability rate; however, its pathogenesis and therapeutic targets are unclear. We aimed to explore the mechanism of hippocampal damage during diabetes and evaluate the potential role of D-pinitol (DP) in protecting hippocampal tissue and improving cognitive dysfunction.

Methods

DP (150 mg/kg/day) was administered intragastrically to streptozocin-induced aging-accelerated mice for 8 weeks. Hippocampal tissues were examined using tandem mass tag (TMT)-based proteomics and liquid chromatography-mass spectrometry (LC-MS)/MS-based non-targeted metabolomic analysis. Differentially expressed proteins (DEPs) and differentially regulated metabolites (DRMs) were screened for further analysis, and some DEPs were verified using western blotting.

Results

Our results showed that 329 proteins had significantly altered hippocampal expression in untreated diabetic mice (DM), which was restored to normal after DP treatment in 72 cases. In total, 207 DRMs were identified in the DM group, and the expression of 32 DRMs was restored to normal post-DP treatment. These proteins and metabolites are involved in metabolic pathways (purine metabolism, arginine and proline metabolism, and histidine metabolism), actin cytoskeleton regulation, oxidative phosphorylation, and Rap1-mediated signaling.

Conclusions

Our study may help to better understand the mechanism of diabetic hippocampal damage and cognitive impairment and suggest a potential therapeutic target.

The Role of Iron Overload in Diabetic Cognitive Impairment: A Review

It is well documented that diabetes mellitus (DM) is strongly associated with cognitive decline and structural damage to the brain. Cognitive deficits appear early in DM and continue to worsen as the disease progresses, possibly due to different underlying mechanisms. Normal iron metabolism is necessary to maintain normal physiological functions of the brain, but iron deposition is one of the causes of some neurodegenerative diseases. Increasing evidence shows that iron overload not only increases the risk of DM, but also contributes to the development of cognitive impairment. The current review highlights the role of iron overload in diabetic cognitive impairment (DCI), including the specific location and regulation mechanism of iron deposition in the diabetic brain, the factors that trigger iron deposition, and the consequences of iron deposition. Finally, we also discuss possible therapies to improve DCI and brain iron deposition.

The mechanism of ferroptosis and its related diseases

Ferroptosis, a regulated form of cellular death characterized by the iron-mediated accumulation of lipid peroxides, provides a novel avenue for delving into the intersection of cellular metabolism, oxidative stress, and disease pathology. We have witnessed a mounting fascination with ferroptosis, attributed to its pivotal roles across diverse physiological and pathological conditions including developmental processes, metabolic dynamics, oncogenic pathways, neurodegenerative cascades, and traumatic tissue injuries. By unraveling the intricate underpinnings of the molecular machinery, pivotal contributors, intricate signaling conduits, and regulatory networks governing ferroptosis, researchers aim to bridge the gap between the intricacies of this unique mode of cellular death and its multifaceted implications for health and disease. In light of the rapidly advancing landscape of ferroptosis research, we present a comprehensive review aiming at the extensive implications of ferroptosis in the origins and progress of human diseases. This review concludes with a careful analysis of potential treatment approaches carefully designed to either inhibit or promote ferroptosis. Additionally, we have succinctly summarized the potential therapeutic targets and compounds that hold promise in targeting ferroptosis within various diseases. This pivotal facet underscores the burgeoning possibilities for manipulating ferroptosis as a therapeutic strategy. In summary, this review enriched the insights of both investigators and practitioners, while fostering an elevated comprehension of ferroptosis and its latent translational utilities. By revealing the basic processes and investigating treatment possibilities, this review provides a crucial resource for scientists and medical practitioners, aiding in a deep understanding of ferroptosis and its effects in various disease situations.

Praeruptorin C alleviates cognitive impairment in type 2 diabetic mice through restoring PI3K/AKT/GSK3β pathway

Diabetic encephalopathy is a common consequence of diabetes mellitus that causes cognitive dysfunction and neuropsychiatric disorders. Praeruptorin C (Pra-C) from the traditional Chinese medicinal herb Peucedanum praeruptorum Dunn. is a potential antioxidant and neuroprotective agent. This study was conducted to investigate the molecular mechanisms underlying the effect of Pra-C on diabetic cognitive impairment. A novel object recognition test and the Morris water maze test were performed to assess the behavioral performance of mice. Electrophysiological recordings were made to monitor synaptic plasticity in the hippocampus. A protein-protein interaction network of putative Pra-C targets was constructed, and molecular docking simulations were performed to predict the potential mechanisms of the action of Pra-C. Protein expression levels were detected by western blotting. Pra-C administration significantly lowered body weight and fasting blood glucose levels and alleviated learning and memory deficits in type 2 diabetic mice. Network pharmacology and molecular docking results suggested that Pra-C affects the PI3K/AKT/GSK3β signaling pathway. Western blot analysis confirmed significant increases in phosphorylated PI3K, AKT, and GSK3β levels in vivo and in vitro upon Pra-C administration. Pra-C alleviated cognitive impairment in type 2 diabetic mice by activating PI3K/AKT/GSK3β pathway.

Ferroptosis-Regulated Cell Death as a Therapeutic Strategy for Neurodegenerative Diseases: Current Status and Future Prospects

Ferroptosis is increasingly being recognized as a key element in the pathogenesis of diverse diseases. Recent studies have highlighted the intricate links between iron metabolism and neurodegenerative disorders. Emerging evidence suggests that iron homeostasis, oxidative stress, and neuroinflammation all contribute to the regulation of both ferroptosis and neuronal health. However, the precise molecular mechanisms underlying the involvement of ferroptosis in the pathological processes of neurodegeneration and its impact on neuronal dysfunction remain incompletely understood. In our Review, we provide a comprehensive analysis and summary of the potential molecular mechanisms underlying ferroptosis in neurodegenerative diseases, aiming to elucidate the disease progression of neurodegeneration. Additionally, we discuss potential therapeutic agents that modulate ferroptosis with the goal of identifying novel drug molecules for the treatment of neurodegenerative disorders.

Cognitive protection of sinomenine in type 2 diabetes mellitus through regulating the EGF/Nrf2/HO-1 signaling, the microbiota-gut-brain axis, and hippocampal neuron ferroptosis

Recent years have witnessed a growing research interest in traditional Chinese medicine as a neuroprotective nutrient in the management of diabetic cognitive dysfunction. However, the underlying molecular mechanisms of sinomenine in mediating ferroptosis of hippocampal neurons have been poorly understood. This study sought to decipher the potential effect and molecular mechanism of sinomenine in the cognitive dysfunction following type 2 diabetes mellitus (T2DM). Multi-omics analysis was conducted to identify the microbiota-gut-brain axis in T2DM patient samples obtained from the publicly available database. In HT-22 cells, erastin was utilized to create a ferroptosis model, and streptozotocin was injected intraperitoneally to create a rat model of DM. It was noted that intestinal flora imbalance occurred in patients with T2DM-associated cognitive dysfunction. Sinomenine could reduce Erastin-induced hippocampus neuronal ferroptosis by increasing EGF expression. EGF protected hippocampal neurons against ferroptosis by activating the Nrf2/HO-1 signaling pathway. Furthermore, in vivo results confirmed that sinomenine blocked ferroptosis of hippocampal neurons and alleviated cognitive dysfunction in T2DM rats. Collectively, these results suggest that sinomenine confers neuroprotective effects by curtailing hippocampal neuron ferroptosis via the EGF/Nrf2/HO-1 signaling and microbiota-gut-brain axis. It may be a candidate for the treatment of diabetic cognitive dysfunction.

Caveolin-1 in endothelial cells: A potential therapeutic target for atherosclerosis

Atherosclerosis (AS) is a chronic vascular disease characterized by lipid accumulation and the activation of the inflammatory response; it remains the leading nation-wide cause of death. Early in the progression of AS, stimulation by pro-inflammatory agonists (TNF-α, LPS, and others), oxidized lipoproteins (ox-LDL), and biomechanical stimuli (low shear stress) lead to endothelial cell activation and dysfunction. Consequently, it is crucial to investigate how endothelial cells respond to different stressors and ways to alter endothelial cell activation in AS development, as they are the earliest cells to respond. Caveolin-1 (Cav1) is a 21-24-kDa membrane protein located in caveolae and highly expressed in endothelial cells, which plays a vital role in regulating lipid transport, inflammatory responses, and various cellular signaling pathways and has atherogenic effects. This review summarizes recent studies on the structure and physiological functions of Cav1 and outlines the potential mechanisms it mediates in AS development. Included are the roles of Cav1 in the regulation of endothelial cell autophagy, response to shear stress, modulation of the eNOS/NO axis, and transduction of inflammatory signaling pathways. This review provides a rationale for proposing Cav1 as a novel target for the prevention of AS, as well as new ideas for therapeutic strategies for early AS.

RETRACTED: Tangzhiqing-mediated NRF2 reduces autophagy-dependent ferroptosis to mitigate diabetes-related cognitive impairment neuronal damage

The publisher of Rejuvenation Research officially retracts the article entitled, "Tangzhiqing-mediated NRF2 reduces autophagy-dependent ferroptosis to mitigate diabetes-related cognitive impairment neuronal damage," by Lingyan Qiu, Mr. Kai Chen, Prof. Xu Wang, and Ms. Yun Zhao. (Rejuvenation Res 2023; epub 6 Jun; doi: 10.1089/rej.2023.0013). After the acceptance and Instant Online publication of the paper, the authors were contacted repeatedly regarding their page proofs, and for further clarification of unresolved issues within the paper. All attempts to reach the authors were unsuccessful. Concurrently, the publisher identified a problematic overlap with a paper published in 2023 in Endocrine, Metabolic & Immune Disorders - Drug Targets.1 This paper was subsequently withdrawn. These troubling details have led the editorial leadership of Rejuvenation Research to lose confidence in the validity of the submission and to retract the paper. All authors were notified of the decision to retract the paper via email. The lead author, Lingyan Qiu, and the corresponding author, Xu Wang, quickly responded and appealed the decision to retract. The appeal was denied. Reference 1. https://www.eurekaselect.com/article/132631. Withdrawn: Experimental study on NRF2 mediated by Chinese medicine tangzhiqing to reduce autophagy-dependent ferroptosis and alleviate neuron damage in HT22 mice with diabetes-related cognitive disorder. 22 June, 2023; DOI: 10.2174/1871530323666230622151649 Diabetes is a chronic condition defined by the body's inability to process glucose. The most common form, diabetes mellitus, reflects the body's insulin resistance, which leads to long-term raised glucose blood levels. These levels can cause oxidative damage, cell stress, and excessive autophagy throughout the body, including the nervous system. Diabetes-related cognitive impairment (DCI) results from chronic elevation of blood glucose, and as diabetes cases continue to rise, so too do comorbidities such as DCI. Although there are medications to address high blood glucose, there are few that can inhibit excessive autophagy and cell death. Therefore, we investigated if the Traditional Chinese Medicine, Tangzhiqing (TZQ), can reduce the impact of DCI in a high-glucose cell model. We used commercially available kits to evaluate cell viability, mitochondrial activity, and oxidative stress. We found that TZQ treatment increased cell viability, ensured continued mitochondrial activity, and reduced reactive oxygen species. We also found that TZQ functions by increasing NRF2 activity, which decreases the ferroptotic-associated pathways that involve p62, HO-1, and GPX4. Therefore, TZQ should be further investigated for its role in reducing DCI.

Vitexin ameliorated diabetic nephropathy via suppressing GPX4-mediated ferroptosis

Diabetic nephropathy (DN) is common complication of diabetes. Ferroptosis is an atypical form of iron-dependent modulated necrosis and have been proven to contribute to the progress of diabetic nephropathy. Vitexin, a flavonoid monomer derived from medicinal plants that has various biological activities including anti-inflammatory and anticancer effects, has not been investigated in diabetic nephropathy studies. However, whether vitexin has a protective effect on diabetic nephropathy remains unclear. In this study, the roles and mechanism of vitexin on alleviating DN were explored in vivo and in vitro. The protective effect of vitexin in diabetic nephropathy were evaluated by in vitro and in vivo experiment. In this research, we validated that vitexin protect HK-2 against HG-induced damage. Besides, vitexin pretreatment also reduced fibrosis (Collagen type I Col I, TGF-β1). Furthermore, vitexin inhibited ferroptosis induced by HG, accompanied by changes of morphological, decrease of ROS, Fe²⁺ and MDA, and increased GSH levels. Meanwhile, vitexin up-regulated the protein expression of GPX4 and SLC7A11 in HG-induced HK-2 cells. Moreover, knockdown of GPX4 by shRNA migrated the protective effect of vitexin on HG-challenged HK-2 and reversed the ferroptosis induced by vitexin. Consistent with in vitro, vitexin alleviated renal fibrosis, damage and ferroptosis in DN rat. In conclusion, our findings revealed that vitexin could alleviate diabetic nephropathy by attenuated ferroptosis via activating GPX4.

Early-life metabolic dysfunction impairs cognition and mitochondrial function in mice

The impact of overnutrition early in life is not restricted to the onset of cardiovascular and metabolic diseases, but also affects critical brain functions related to cognition. This study aimed to evaluate the relationship between peripheral metabolic and bioenergetic changes induced by a two-hit protocol and their impact on cognitive function in juvenile mice. Three-week-old male C57BL/6 mice received a high-fat diet (HFD) or control diet for 7 weeks, associated with 2 low doses of streptozotocin (STZ) or vehicle. Despite the absence of obesity, HFD+STZ impaired glucose metabolism and induced a trend towards cholesterol increase. The two-hit protocol impaired recognition and spatial memories in juvenile mice, without inducing a depressive-like behavior. HFD+STZ mice presented increased immunoreactivity for GFAP and a trend towards a decrease in NeuN in the hippocampus. The treatment caused a bioenergetic impairment in the hippocampus, characterized by a decrease in both O₂ consumption related to ATP production and in the maximum respiratory capacity. The thermogenic capacity of brown adipose tissue was impaired by the two-hit protocol, here verified through the absence of a decrease in O₂ consumption after uncoupled protein-1 inhibition and an increase in the reserve respiratory capacity. Impaired mitochondrial function was also observed in the liver of HFD+STZ juvenile mice, but not in their heart. These results indicate that exposure to HFD+STZ early in life has a detrimental impact on the bioenergetic and mitochondrial function of tissues with metabolic and thermogenic activities, which is likely related to hippocampal metabolic changes and cognitive impairment.

Iron metabolism and ferroptosis in type 2 diabetes mellitus and complications: mechanisms and therapeutic opportunities

The maintenance of iron homeostasis is essential for proper endocrine function. A growing body of evidence suggests that iron imbalance is a key factor in the development of several endocrine diseases. Nowadays, ferroptosis, an iron-dependent form of regulated cell death, has become increasingly recognized as an important process to mediate the pathogenesis and progression of type 2 diabetes mellitus (T2DM). It has been shown that ferroptosis in pancreas β cells leads to decreased insulin secretion; and ferroptosis in the liver, fat, and muscle induces insulin resistance. Understanding the mechanisms concerning the regulation of iron metabolism and ferroptosis in T2DM may lead to improved disease management. In this review, we summarized the connection between the metabolic pathways and molecular mechanisms of iron metabolism and ferroptosis in T2DM. Additionally, we discuss the potential targets and pathways concerning ferroptosis in treating T2DM and analysis the current limitations and future directions concerning these novel T2DM treatment targets.

Ferulic acid alleviates high fat diet-induced cognitive impairment by inhibiting oxidative stress and apoptosis

Cognitive impairment has become a major public health problem. Growing evidence suggests that high-fat diet (HFD) can cause cognitive dysfunction and increase the risk of dementia. However, effective treatment for cognitive impairment is not available. Ferulic acid (FA) is a single phenolic compound with anti-inflammatory and antioxidant properties. Nevertheless, its role in regulating learning and memory in HFD-fed mice and the underlying mechanism remains unclear. In this study, we aimed to identify the neuroprotective mechanisms of FA in HFD induced cognitive impairment. We found that FA improved the survival rate of HT22 cells treated with palmitic acid (PA), inhibited cell apoptosis, and reduced oxidative stress via the IRS1/PI3K/AKT/GSK3β signaling pathway; Furthermore, FA treatment for 24 weeks improved the learning and memory of HFD-fed mice and decreased hyperlipidemia. Moreover, the expression of Nrf2 and Gpx4 proteins were decreased in HFD-fed mice. After FA treatment, the decline of these proteins was reversed. Our study showed that the neuroprotective effect of FA on cognitive impairment was related to the inhibition of oxidative stress and apoptosis and regulation of glucose and lipid metabolism. These findings suggested that FA can be developed as a potential agent for the treatment of HFD-induced cognitive impairment.

Activated AMPK mitigates diabetes-related cognitive dysfunction by inhibiting hippocampal ferroptosis

Clinical and preclinical interest in Type 2 diabetes (T2D)-associated cognitive dysfunction (TDACD) has grown in recent years. However, the precise mechanisms underlying TDACD need to be further elucidated. Ferroptosis was reportedly involved in neurodegenerative diseases and diabetes-related organ injuries; however, its role in TDACD remains elusive. In this study, mice fed with a high-fat-diet combined with streptozotocin (HFD-STZ) were used as a T2D model to assess the role of ferroptosis in cognitive dysfunction. We found that ferroptosis was mainly activated in hippocampal neurons but not in microglia or astrocytes. Accordingly, increased levels of transferrin receptor and decreased levels of ferritin, GPX4, and SLC7A11 were observed in hippocampal neurons. In addition, pre-treatment with liproxstatin-1, a ferroptosis inhibitor, attenuated iron accumulation and oxidative stress response, which resulted in improved cognitive function in the HFD-STZ group. Furthermore, we found that p-AMP-activated protein kinase (AMPK) was decreased in the HFD-STZ group. Pre-treatment with AMPK agonist increased the expression of AMPK and GPX4, but decreased lipocalin 2 (LCN2) in the hippocampus that resulted in improved spatial learning ability in the HFD-STZ group. Taken together, we found that activation of neuronal ferroptosis in the hippocampus contributed to cognitive impairment of HFD-STZ mice. Furthermore, AMPK activation may reduce hippocampal ferroptosis, and consequently improve cognitive performance in diabetic mice.

Identification of ferroptosis-related genes in syncytiotrophoblast-derived extracellular vesicles of preeclampsia

Preeclampsia (PE), defined as new-onset hypertension and multi-organ systemic complication during pregnancy, is the leading cause of maternal and neonatal mortality and morbidity. With extracellular vesicles research progresses, current data refers to the possibility that ferroptosis may play a role in exosomal effects. Evidence has suggested that ferroptosis may contribute to the pathogenesis of preeclampsia by bioinformatics analyses. The purpose of the current study is to identify the potential ferroptosis-related genes in syncytiotrophoblast-derived extracellular vesicles (STB-EVs) of preeclampsia using bioinformatics analyses. Clinical characteristics and gene expression data of all samples were obtained from the NCBI GEO database. The differentially expressed mRNAs (DE-mRNAs) in STB-EVs of preeclampsia were screened and then were intersected with ferroptosis genes. Functional and pathway enrichment analyses of ferroptosis-related DE-mRNAs in STB-EVs were performed. Ferroptosis-related hub genes in STB-EVs were identified by Cytoscape plugin CytoHubba with a Degree algorithm using a protein-protein interaction network built constructed from the STRING database. The predictive performance of ferroptosis-related hub genes was determined by a univariate analysis of receiver operating characteristic (ROC). The miRNA-hub gene regulatory network was constructed using the miRwalk database. A total of 1976 DE-mRNAs in STB-EVs were identified and the most enriched item identified by gene set enrichment analysis was signaling by G Protein-Coupled Receptors (normalized enrichment score = 1.238). These DE-mRNAs obtained 26 ferroptosis-related DE-mRNAs. Ferroptosis-related DE-mRNAs of gene ontology terms and Encyclopedia of Genes and Genomes pathway enrichment analysis were enriched significantly in response to oxidative stress and ferroptosis. Five hub genes (ALB, NOX4, CDKN2A, TXNRD1, and CAV1) were found in the constructed protein-protein interaction network with ferroptosis-related DE-mRNAs and the areas under the ROC curves for ALB, NOX4, CDKN2A, TXNRD1, and CAV1 were 0.938 (CI: 0.815-1.000), 0.833 (CI: 0.612-1.000), 0.875 (CI: 0.704-1.000), 0.958 (CI: 0.862-1.000), and 0.854 (CI: 0.652-1.000) in univariate analysis of ROC. We constructed a regulatory network of miRNA-hub gene and the findings demonstrate that hsa-miR-26b-5p, hsa-miR-192-5p, hsa-miR-124-3p, hsa-miR-492, hsa-miR-34a-5p and hsa-miR-155-5p could regulate most hub genes. In this study, we identified several central genes closely related to ferroptosis in STB-EVs (ALB, NOX4, CDKN2A, TXNRD1, and CAV1) that are potential biomarkers related to ferroptosis in preeclampsia. Our findings will provide evidence for the involvement of ferroptosis in preeclampsia and improve the understanding of ferroptosis-related molecular pathways in the pathogenesis of preeclampsia.

Electroacupuncture May Inhibit Oxidative Stress of Premature Ovarian Failure Mice by Regulating Intestinal Microbiota

Premature ovarian failure (POF) is the leading cause of female infertility, and there is no optimal treatment or medication available currently. For POF, electroacupuncture (EA) has been considered a promising therapeutic approach, but the mechanism for this is not clear. In this study, we explored the effects of EA (CV4, ST36, and SP6) on oxidative stress and intestinal microbiota of high-fat and high-sugar- (HFHS-) induced POF mice. The development of mice follicles was observed by hematoxylin and eosin (HE) staining. The serum levels of estrone (E1), estrogen (E2), estriol (E3), and 21-deoxycortisol (21D) were measured by the HPLC-MS/MS method. The concentrations of Fe2+, superoxide dismutase (SOD), hydroxyl radical (·OH), glutathione (GSH), superoxide anion, and malondialdehyde (MDA) were measured by spectrophotometry. The 16S-rDNA sequencing was used to measure many parameters related to the host gut bacteriome and mycobiome composition, relative abundance, and diversity. mRNA expression levels of ferroptosis-related genes were determined by RT-qPCR. After 4 weeks of EA intervention in POF mice, mature follicles were increased and the levels of the sex hormone were improved. SOD activities, antisuperoxide activities, and GSH increased while MDA, ·OH, and Fe2+ decreased. In addition, EA also altered the intestinal microbiota. These results reveal that EA can effectively inhibit ovarian oxidative stress and the accumulation of Fe2+ in POF mice. It may be that the alteration in the intestinal microbiota is one of the potential mechanisms of EA treatment. These findings suggest that EA has clinical potential as a safe treatment for POF.

Ferroptosis and Its Role in Chronic Diseases

Ferroptosis, which has been widely associated with many diseases, is an iron-dependent regulated cell death characterized by intracellular lipid peroxide accumulation. It exhibits morphological, biochemical, and genetic characteristics that are unique in comparison to other types of cell death. The course of ferroptosis can be accurately regulated by the metabolism of iron, lipids, amino acids, and various signal pathways. In this review, we summarize the basic characteristics of ferroptosis, its regulation, as well as the relationship between ferroptosis and chronic diseases such as cancer, nervous system diseases, metabolic diseases, and inflammatory bowel diseases. Finally, we describe the regulatory effects of food-borne active ingredients on ferroptosis.