Microglia play pivotal roles in post-intracerebral hemorrhage (ICH) neural injury. Iron metabolism, which is dysregulated after ICH, participates in microglial dysfunction. Previous studies have shown that iron metabolism-related lipocalin-2 (LCN2) is involved in regulating microglial function following ICH. In this study, we investigated the role of LCN2 in microglial function following ICH.
The BV2 (microglia) cell line, transfected with LCN2 for overexpression/interference, received a blood infusion from C57BL/6 mice in vitro. For the in vivo study of LCN2 function, an LCN2 knockout was conducted in mice. Liproxstatin-1 and RSL3 were used to manipulate ferroptosis and to study the effects of LCN2 on microglia after ICH. A BV2 (microglia) cell line, transfected with ferritin light chain (FTL) for overexpression/interference, was co-cultured with primary cultured neurons for a study on the mechanism of LCN2. Behavioral tests were conducted pre-ICH and on days 3, 7, and 28 post-ICH, and the brains and cultured cells were collected for protein, histological, and morphological studies.
Brain LCN2 expression was upregulated in microglia, astrocytes, and neurons and played hazardous roles after ICH. In microglia, LCN2 promoted ferroptosis, which facilitated neural injury after ICH. LCN2-mediated FTL deficiency was shown to be responsible for microglial ferroptosis-induced neural injury.
Our study suggests that LCN2-enhanced microglial ferroptosis plays a detrimental role by inducing FTL deficiency after ICH. The current study reveals a novel molecular mechanism involved in the pathophysiological progression of ICH.

Ferritin light chain (FtL) is a complex formed by apoferritin and iron core and is one of the main storage forms of iron. Currently, the precise role of FtL in cerebral ischemia/reperfusion injury (CIRI) remains undetermined. This investigation aimed to elucidate the roles and underlying mechanisms of FtL in CIRI. To induce CIRI, an oxygen-glucose deprivation (OGD) model in microglia and middle cerebral artery occlusion (MCAO) model were established using C57BL/6 J mice. The in vivo and in vitro FtL expression patterns were assessed. Furthermore, the potential regulatory mechanism of FtL at the upstream level was also explored. In addition, the in vivo and in vitro role of FtL in post-ischemic inflammation was also clarified. The results indicated that FtL was up-regulated in OGD-induced microglia and CIRI mice. Moreover, OGD activated HIF1α, which interacted with the FtL promoter region as an activator, thereby increasing FtL expression. Furthermore, FtL attenuated the release of pro-inflammatory cytokines (TNFα, IL6) and decreased levels of COX2 and iNOS in microglia; however, FtL knockdown had the opposite effects. Up-regulated FtL was observed to inhibit OGD-induced NF-κB activation in microglia, decreased IκBα degradation, and reduced NF-κB/p65 nuclear translocation. In summary, this study revealed an underlying mechanism of FtL upregulation via HIF1α and highlighted its protective role against post-ischemic neuroinflammation, indicating the potential of FtL as a target for CIRI treatment.

Ferroptosis hallmarked by lipid peroxidation and iron homeostasis imbalance is involved in the occurrence and development of various diseases. The plant growth regulator chlormequat chloride (CCC) can contribute to the causality and exacerbation of reproductive disorders. However, the mechanism by which CCC may cause Leydig cell attenuation remains poorly understood. In this study, TM3 Leydig cells were used to investigate the inhibitory effect of CCC on cell growth and its possible mechanism. The results showed that CCC caused apoptosis, pyroptosis, ferroptosis and necroinflammation in TM3 cells. By comparing the effects of ferroptosis inhibitor Ferrostatin-1 (Fer-1) and pan-Caspase inhibitor Z-VAD-FMK (ZVF) on lipid peroxidation and Caspase-mediated regulated cell death (RCD), we found that Fer-1 was better at rescuing the growth of TM3 cells than ZVF. Although ZVF reduced mitochondrial ROS level and inhibited the activation of Caspase3 and Caspase1, it could not significantly ameliorate lipid peroxidation and the levels of IL-1β and HMGB1 like Fer-1. Therefore, ferroptosis might be a key non apoptotic RCD mode responsible for CCC-driven inflammation, leading to weakened viability and proliferation of TM3 cells. In addition, overexpression of ferritin light chain (FTL) promoted the resistance of TM3 cells to CCC-induced ferroptosis-mediated inflammation and to some extent improved the inhibition of viability and proliferation. Altogether, ferroptosis-initiated inflammation might play a key role in CCC-impaired TM3 cell growth.

As an indispensable trace element, iron is essential for many biological processes. Increasing evidence has shown that virus infection can perturb iron metabolism and play a role in the occurrence and development of viral infection-related diseases. Ferritin plays a crucial role in maintaining the body\'s iron homoeostasis. It is an important protein to stabilise the iron balance in cells. Ferritin is a 24-mer hollow iron storage protein composed of two subunits: ferritin heavy chain and ferritin light chain. It was reported that ferritin is not only an intra-cellular iron storage protein, but also a pathogenic mediator that enhances the inflammatory process and stimulates the further inflammatory pathway, which is a key member of the vicious pathogenic cycle to perpetuate. Ferritin exerts immuno-suppressive and pro-inflammatory functions during viral infection. In this review, we describe in detail the basic information of ferritin in the first section, including its structural features, the regulation of ferritin. In the second part, we focus on the role of ferritin in viral infection-related diseases and the molecular mechanisms by which viral infection regulates ferritin. The last section briefly outlines the potential of ferritin in antiviral therapy. Given the importance of iron and viral infection, understanding the role of ferritin during viral infection helps us understand the relationship between iron metabolic dysfunction and viral infection, which provides a new direction for the development of antiviral therapeutic drugs.

Background: Iron overload can lead to organ and cell injuries. Although the mechanisms of iron-induced cell damage have been extensively studied using various cells, little is known about these processes in kidney cells. Methods: In this study, we first examined the correlation between serum iron levels and kidney function. Subsequently, we investigated the molecular impact of excess iron on kidney cell lines, HEK293T and HK-2. The presence of the upregulated protein was further validated in urine. Results: The results revealed that excess iron caused significant cell death accompanied by morphological changes. Transcriptomic analysis revealed an up-regulation of the ferroptosis pathway during iron treatment. This was confirmed by up-regulation of ferroptosis markers, ferritin light chain (FTL), and prostaglandin-endoperoxide synthase 2 (PTGS2), and down-regulation of acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4) using real-time PCR and Western blotting. In addition, excess iron treatment enhanced protein and lipid oxidation. Supportively, an inverse correlation between urinary FTL protein level and kidney function was observed. Conclusion: These findings suggest that excess iron disrupts cellular homeostasis and affects key proteins involved in kidney cell death. Our study demonstrated that high iron levels caused kidney cell damage. Additionally, urinary FTL might be a useful biomarker to detect kidney damage caused by iron toxicity. Our study also provided insights into the molecular mechanisms of iron-induced kidney injury, discussing several potential targets for future interventions.

Background: Tumor-associated macrophages (TAMs), the most abundant non-tumor cell population in the glioma microenvironment, play a crucial role in immune evasion and immunotherapy resistance of glioblastoma (GBM). However, the regulatory mechanism of the immunosuppressive TME of GBM remains unclear. Methods: Bioinformatics were used to analyse the potential role of ferritin light chain (FTL) in GBM immunology and explore the effects of FTL on the reprogramming of the GBM immune microenvironment and GBM progression. Results: The FTL gene was found to be upregulated in TAMs of GBM at both the bulk and single-cell RNA-seq levels. FTL contributed to the protumor microenvironment by promoting M2 polarization in TAMs via inhibiting the expression of iPLA2β to facilitate the ferroptosis pathway. Inhibition of FTL in TAMs attenuated glioma angiogenesis, promoted the recruitment of T cells and sensitized glioma to anti-PD1 therapy. Conclusion: Our study suggested that FTL promoted the development of an immunosuppressive TME by inducing M2 polarization in TAMs, and inhibition of FTL in TAMs reprogrammed the TME and sensitized glioma to anti-PD1 therapy, providing a new strategy for improving the therapeutic effect of anti-PD1.

Cisplatin, which is effective for the treatment of solid tumors, also can induce cochlear hair cell damage. Therefore, this study was intended to explore how Hippo/YAP signaling pathway affects the cochlear hair cell injury by regulating ferroptosis. After cisplatin induction, or LAT1-IN-1 (YAP activator) and verteporfin (YAP inhibitor) treatment or transfection, the viability of HEI-OC1 cells was detected by cell counting kit-8 (CCK-8) assay. The iron level and the levels of oxidative stress markers (ROS, MDA and 4-HNE) were analyzed by iron assay kit, reactive oxygen species (ROS), malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) assay kits, respectively. The expression of ferritin light chain (FTL) in HEI-OC1 cells was detected by immunofluorescence and protein expressions of yes associated protein (YAP,) phosphorylated YAP (p-YAP), transferrin receptor (TFRC), glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and solute carrier family 7 member 11 (SLC7A11) in HEI-OC1 cells were detected by western blot. The transcription of FTL and TFRC by YAP1 was verified by dual-luciferase reporter assay. The transfection efficiency of small interfering RNA (si-RNA) specific to FTL (siRNA-FTL) and TFRC (siRNA-TFRC) was confirmed by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). As a result, cisplatin inhibited the viability of HEI-OC1 cells by increasing free Fe2+ level and decreasing FTL level. LAT1-IN-1 promoted the viability of cisplatin-induced HEI-OC1 cells by suppressing oxidative stress level, free Fe2+ level, ferroptosis and increasing FTL level, while the effect of verteporfin was the opposite. YAP1 transcriptionally regulated the expression of FTL and TFRC. Inhibition of FTL suppressed the viability of cisplatin-induced HEI-OC1 cells by increasing oxidative stress level, free Fe2+ level, ferroptosis and decreasing FTL level, while the effect of TFRC inhibition was the opposite. In conclusion, YAP1 ameliorated cochlear hair cell injury by upregulating FTL and TFRC to suppress ferroptosis.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) remains one of the most lethal cancers worldwide accompany with an extremely poor prognosis. Therefore, this study aims to screen for new molecules affecting ESCC and explore their mechanisms of action to provide ideas for targeted therapies for ESCC.
METHODS: Firstly, we screened out the membrane protein SCARA5 by high-throughput sequencing of the ESCC patient tissues, and RT-qPCR and WB were used to verify the differential expression of SCARA5 in esophageal cell lines, and IHC analyzed the expression localization of SCARA5 in ESCC tissue. Then, flow cytometry, wound healing assay, Transwell assay and CCK-8 assay were used to explore the effects of SCARA5 on cell cycle, migration and invasion as well as cell proliferation activity of esophageal squamous carcinoma cells. Meanwhile, transmission electron microscopy was used to detect changes in cellular mitochondrial morphology, and flow cytometry were used to detect changes in intracellular reactive oxygen metabolism, and immunofluorescence and flow cytometry were used to detect changes in intracellular Fe2+. Mechanistically, co-immunoprecipitation was used to detect whether SCARA5 binds to ferritin light chain, and ferroptosis-related protein expression was detected by WB. Finally, the tumor xenograft model was applied to validation the role of SCARA5 tumor growth inhibition in vivo.
RESULTS: We found that SCARA5 was aberrantly decreased in ESCC tissues and cell lines. Furthermore, we confirmed that SCARA5 suppressed the cell cycle, metastasis and invasion of ESCC cells. Meanwhile, we also found that overexpression of SCARA5 caused changes in mitochondrial morphology, accumulation of intracellular reactive oxygen species and increased intracellular Fe2+ in ESCC cells, which induced ferroptosis in ESCC cells. Mechanically, we validated that SCARA5 combined with ferritin light chain and increased intracellular Fe2+. As well as, overexpression SCARA5 induced ferroptosis by increasing ferritin light chain in nude mice subcutaneous tumors and inhibited the growth of nude mice subcutaneous tumors.
CONCLUSIONS: Collectively, our findings demonstrated that SCARA5 suppressed the proliferation and metastasis of ESCC by triggering ferroptosis through combining with ferritin light chain.

DL-3-n-butylphthalide (NBP)-a compound isolated from Apium graveolens seeds-is protective against brain ischemia via various mechanisms in humans and has been approved for treatment of acute ischemic stroke. NBP has shown recent potential as a treatment for Parkinson\'s disease. However, the underlying mechanism of action of NBP remains poorly understood. In this study, we established a rat model of Parkinson\'s disease by intraperitoneal injection of rotenone for 28 successive days, followed by intragastric injection of NBP for 14-28 days. We found that NBP greatly alleviated rotenone-induced motor disturbance in the rat model of Parkinson\'s disease, inhibited loss of dopaminergic neurons and aggregation of α-synuclein, and reduced iron deposition in the substantia nigra and iron content in serum. These changes were achieved by alterations in the expression of the iron metabolism-related proteins transferrin receptor, ferritin light chain, and transferrin 1. NBP also inhibited oxidative stress in the substantia nigra and protected mitochondria in the rat model of Parkinson\'s disease. Our findings suggest that NBP alleviates motor disturbance by inhibition of iron deposition, oxidative stress, and ferroptosis in the substantia nigra.

Background: The carcinogenesis and prognosis of hepatocellular carcinoma (HCC) involve complex molecular mechanisms, and ferroptosis is related to the development and therapeutic efficacy of HCC, but the specific mechanism and prognostic role of ferroptosis-related genes in HCC have not been elucidated. Methods: Differentially expressed gene analysis, Cox regression, and unsupervised consensus clustering were applied to identify crucial ferroptosis regulators and establish ferroptosis-related subtypes in HCC. Random forest analysis and survival analysis were adopted to confirm FTL as the hub prognostic and diagnostic ferroptosis regulator in HCC. Results: The ferroptosis-related subtypes based on the crucial prognostic ferroptosis regulators showed that patients in fescluster A had a higher survival probability (p < 0.001) and better clinical characteristics than patients in fescluster B in the TCGA-LIHC cohort. Patients with a high tumor mutation burden (TMB) in fescluster B presented a significantly poorer prognosis. FTL was the core ferroptosis regulator, and its low expression revealed a significant survival advantage compared with its high expression (p = 0.03). The expression and predictive value of FTL were both closely related to the clinical features (p < 0.05). Expression of FTL accurately distinguished HCC from normal tissues in the TCGA-LIHC cohort, ICGC cohort, and GSE14520 dataset. In addition, higher infiltrating fractions of immune cells, such as activated CD8+ T cells and Gamma delta T cells, mainly enriched immune-related signaling pathways, including the IL2-STAT3 signaling pathway and interferon-gamma response signaling pathway, and higher expression of immune checkpoints, including PDCD1, CTLA4, TIGIT, and CD83, were presented in patients with high FTL expression (p < 0.05). Patients with high FTL were more sensitive to some targeted drugs, such as cisplatin, dasatinib, and sorafenib, than those with low FTL (p < 0.05). A nomogram based on FTL accurately predicted the prognosis of HCC. Further knockdown of FTL was determined to significantly inhibit cell proliferation and migration in HCC. Conclusion: Our study validated ferroptosis-related subtypes and FTL with effective prognostic value in HCC and was beneficial for identifying candidates suitable for targeted drug therapy and immunotherapy, thereby offering further insight into individual treatment strategies to improve disease outcomes in HCC patients.