acyl-CoA Synthetase Long-chain Family Member Research Articles

ACSL4 contributes to ferroptosis-mediated rhabdomyolysis in exertional heat stroke.

BackgroundRhabdomyolysis (RM) is a common complication of exertional heat stroke (EHS) and constitutes a direct cause of death. However, the mechanism underlying RM following EHS remains unclear.MethodsThe murine EHS model was prepared by our previous protocol. RNA sequencing is applied to identify the pathological pathways that contribute to RM following EHS. Inhibition of the acyl‐CoA synthetase long‐chain family member 4 (ACSL4) was achieved by RNA silencing in vitro prior to ionomycin plus heat stress exposure or pharmacological inhibitors in vivo prior to heat and exertion exposure. The histological changes, the iron accumulation, oxidized phosphatidylethanolamines species, as well as histological evaluation and levels of lipid metabolites in skeletal muscle tissues were measured.ResultsWe demonstrated that ferroptosis contributes to RM development following EHS. Ferroptosis inhibitor ferrostatin‐1 administration once EHS onset significantly ameliorated the survival rate of EHS mice from 35.357% to 52.288% within 24 h after EHS (P = 0.0028 compared with control) and markedly inhibited RM development induced by EHS. By comparing gene expression of between sham heat rest (SHR) (n = 3) and EHS (n = 3) mice in the gastrocnemius (Gas) muscle tissue, we identified that Acsl4 mRNA expression is elevated in Gas muscle tissue of EHS mice (P = 0.0038 compared with SHR), so as to its protein levels (P = 0.0001 compared with SHR). Followed by increase in creatine kinase (CK) and myoglobin (MB) levels, the labile iron accumulation, decrease in glutathione peroxidase 4 (GPX4) expression, and elevation of lipid peroxidation products. From in vivo and in vitro experiments, inhibition of Acsl4 significantly improves muscle cell death caused by EHS, thereby ameliorating RM development, followed by reduction in CK and MB levels by 30–40% (P < 0.0001; n = 8–10) and 40% (P < 0.0001; n = 8–10), restoration of GPX4 expression, and decrease in lipid peroxidation products. Mechanistically, ACSL4‐mediated RM seems to be Yes‐associated protein (YAP) dependent via TEA domain transcription factor1/TEA domain transcription factor4.ConclusionsThese findings demonstrate an important role of ACSL4 in mediating ferroptosis activation in the development of RM following EHS and suggest that targeting ACSL4 may represent a novel therapeutic strategy to limit the skeletal muscle cell death and prevent RM after EHS.

Thrombin induces ACSL4-dependent ferroptosis during cerebral ischemia/reperfusion

Ischemic stroke represents a significant danger to human beings, especially the elderly. Interventions are only available to remove the clot, and the mechanism of neuronal death during ischemic stroke is still in debate. Ferroptosis is increasingly appreciated as a mechanism of cell death after ischemia in various organs. Here we report that the serine protease, thrombin, instigates ferroptotic signaling by promoting arachidonic acid mobilization and subsequent esterification by the ferroptotic gene, acyl-CoA synthetase long-chain family member 4 (ACSL4). An unbiased multi-omics approach identified thrombin and ACSL4 genes/proteins, and their pro-ferroptotic phosphatidylethanolamine lipid products, as prominently altered upon the middle cerebral artery occlusion in rodents. Genetically or pharmacologically inhibiting multiple points in this pathway attenuated outcomes of models of ischemia in vitro and in vivo. Therefore, the thrombin-ACSL4 axis may be a key therapeutic target to ameliorate ferroptotic neuronal injury during ischemic stroke.

TMT-Based Quantitative Proteomics Analysis Reveals the Panoramic Pharmacological Molecular Mechanism of β-Elemonic Acid Inhibition of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide but has limited available therapeutic methods; therefore, there is a need to develop highly efficient prevention and treatment strategies. Here, we investigated the anti-cancer activity of β-elemonic acid (EA) in CRC in vitro and in vivo. Our results showed that EA inhibited cell proliferation and migration in the CRC cell lines SW480 and HCT116. Moreover, EA significantly suppressed the growth of transplanted colorectal tumors in nude mice. Interestingly, high-throughput tandem mass tag (TMT)-based quantitative proteomics indicated that EA mainly targets tumor mitochondria and attenuates the translation of 54 mitochondrial ribosome proteins, many of which are discovered significantly upregulated in clinical CRC patients. More interestingly, EA at a low concentration (lower than 15 μg/ml) repressed the cell cycle by downregulating CDK1, CDK6, and CDC20, whereas at a high concentration (higher than 15 μg/ml), caused a non-apoptotic cell death—ferroptosis via downregulating ferritin (FTL) and upregulating transferrin (TF), ferroxidase (CP), and acyl-CoA synthetase long-chain family member 4 (ACSL4). This is the first report on the panoramic molecular mechanism of EA against CRC, which would make great contributions to developing a novel drug for colorectal cancer therapy.

Itraconazole Inhibits the Growth of Cutaneous Squamous Cell Carcinoma by Targeting HMGCS1/ACSL4 Axis.

Background: Cutaneous squamous cell carcinoma (cSCC) is a common cutaneous cancer with increasing incidence. Itraconazole has been identified as a potential anticancer drug candidate. However, the role of itraconazole in cSCC was still unclear. Our objective is exploring the therapeutic potential of itraconazole in cSCC and investigate its molecular mechanism. Methods: The anti-proliferation effect of itraconazole was tested with CCK-8 assay and clone formation assay. Cell cycle distribution and apoptosis rate were detected using flow cytometry and TUNEL assay, respectively. Transcriptomic and proteomic analyses were used to explore the underlying anti-cancer mechanism. Luciferase reporter assay was used for promoter activity. Reactive oxygen species (ROS), lipid peroxidation and iron accumulation were examined. The in vivo efficacy of itraconazole was assessed in a xenograft model. Results: Itraconazole inhibited the cell proliferation, induced apoptosis and blocked cell cycle of cSCC cells. An integrated analysis of transcriptomic and proteomic analyses identified that 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) and acyl-CoA synthetase long-chain family member 4 (ACSL4) were significantly upregulated in A431 cells treated with itraconazole. HMGCS1 silencing reversed the antiproliferative activity of itraconazole in A431 cells. Dual-luciferase assay showed that itraconazole could promote HMGCS1 transcription. HMGCS1 silencing abated the expression of ACSL4 in A431 cells. The level of ROS, lipid peroxidation, as well as iron accumulation were increased by itraconazole. Moreover, treatment with itraconazole impeded tumor growth in A431-bearing mice. Conclusion: We proved itraconazole inhibits the growth of cSCC by regulating HMGCS1/ACSL4 axis.

Depletion of mmu_circ_0001751 (circular RNA Carm1) protects against acute cerebral infarction injuries by binding with microRNA-3098-3p to regulate acyl-CoA synthetase long-chain family member 4

ABSTRACT Circular RNAs (circRNAs) play a critical role in acute cerebral infarction (ACI). Our research discussed the effect of circ-Carm1 in ACI and its potential molecular mechanisms. Healthy controls and patients with ACI were included in this study. The establishment of an oxygen and glucose deprivation/reoxygenation (OGD/R) model of HT22 cells was conducted to mimic ACI in vitro. Quantitative reverse transcription polymerase chain reaction was conducted to determine mRNA levels extracted from serum and HT22 cell samples, and Western blotting was performed to determine protein levels. Terminal deoxynucleotidyl transferase dUTP nick end labeling and cell counting kit 8 assays were conducted to evaluate cellular functions. Concentrations of Fe2+ and malondialdehyde, and levels of transferrin receptor 1, glutathione peroxidase 4, and glutathione were evaluated to determine ferroptosis in OGD/R-induced HT22 cells. The binding relationships between mRNAs and miRNAs were verified. circ-Carm1 was highly expressed in OGD/R-treated HT22 cells. Deficiency of circ-Carm1 restored cell viability and suppressed ferroptosis in OGD/R-induced HT22 cells. miR-3098-3p was predicted to be a target of circ-Carm1. The miR-3098-3p inhibitor partly neutralized the functions of circ-Carm1 in OGD/R-induced HT22 cells. Furthermore, acyl-CoA synthetase long-chain family member 4 (ACSL4) was confirmed to be a downstream target of miR-3098-3p and was elevated in OGD/R-induced HT22 cells. Overexpression of ACSL4 mitigated the functions of miR-3098-3p and accelerated HT22 cell dysfunction. Hence, circ-Carm1 is upregulated in ACI. circ-Carm1 suppression protects HT22 cells from dysfunction by inhibiting ferroptosis. Therefore, inducing circ-Carm1 deficiency may be a promising therapeutic method for ACI.

Anti-Inflammatory and Anti-Oxidant Activity of Ultra-Short Wave Diathermy on LPS-Induced Rat Lung Injury.

We studied the lung-protective effect and mechanisms of the anti-inflammatory and antioxidant effects of ultra-short-wave diathermy (USWD) in a rat model of LPS-induced acute lung injury. Histological examination of the lung tissues was performed and the levels of oxidative stress-related factors and inflammatory cytokines were measured. It was shown that the lung injury score, the lung wet-to-dry weight ratio (W/D), oxidative stress-related factors malondialdehyde and acyl-CoA synthetase long-chain family member 4 (ACSL4), and inflammatory cytokines were increased after LPS administration, while USWD treatment reduced these parameters. In addition, superoxide dismutase and glutathione peroxidase 4 were decreased in rats with LPS-induced acute lung injury, while USWD therapy up-regulated the expression of these enzymes. Thus, USWD could antagonize lung injury by inhibiting oxidative stress and inflammatory response in rats with acute lung injury. USWD can be a promising adjunctive treatment to counter oxidative stress and inflammation and a potential therapeutic candidate for the treatment of patients with this pathology.

MiR-218-5p Affects Subcutaneous Adipogenesis by Targeting ACSL1, a Novel Candidate for Pig Fat Deposition

As a centre enzyme in fatty acid activation, acyl-CoA synthetase long-chain family member 1 (ACSL1) plays an important role in body lipid homeostasis. However, the functions of ACSL1 in the subcutaneous adipogenesis of pigs are largely unknown. In the present study, we found that the expression of ACSL1 significantly increased during the process of porcine preadipocyte differentiation. Moreover, silencing of ACSL1 in preadipocytes decreased levels of triglyceride and adipogenic-related markers, including FABP4, APOE, and FASN (p < 0.01), and simultaneously increased levels of lipolytic-related markers, such as ATGL and HSL (p < 0.05). Conversely, overexpression of ACSL1 in preadipocytes increased levels of triglyceride and FABP4, APOE, and FASN (p < 0.01), and reduced levels of ATGL and HSL (p < 0.05). Luciferase reporter assays revealed that ACSL1 is a target of miR-218-5p, which can reduce the mRNA and protein levels of ACSL1 by directly binding the 3′ untranslated region of ACSL1. Furthermore, miR-218-5p has an inhibition role in porcine preadipocyte differentiation by suppressing ACSL1 expression. Taken together, these data provide insights into the mechanism of the miR-218-5p/ACSL1 axis in regulating subcutaneous fat deposition of pigs.

Genetic Alteration, Prognostic and Immunological Role of Acyl-CoA Synthetase Long-Chain Family Member 4 in a Pan-Cancer Analysis.

Acyl-CoA Synthetase long-chain family member 4 (ACSL4) is a member of acyl-CoA synthetase protein long-chain family, which is associated with amino acid synthesis, lipid synthesis and lipid peroxidation dependent iron death. However, the role of ACSL4 in generalized carcinoma remains unclear. We aim to analyze the expression and prognostic value of ACSL4 in pan-cancer, and further explore the correlation between ACSL4 and immune infiltration. Through ONCOMINE, TIMER (Tumor Immune Estimation Resource), GEPIA (Gene expression Profiling Interactive), UALCAN and HPA, ACSL4 expression patterns of in pan-cancer were analyzed. The prognostic value of ACSL4 was analyzed using PrognoScan and Kaplan-Meier Plotter databases. Furthermore, gene variation and epigenetic modification of ACSL4 were analyzed by cBioPortal and GSCA databases. Meanwhile, GEPIA and TIMER databases applied to evaluate the relationship between ACSL4 expression and immune infiltration. These results indicate that ACSL4 expression is down-regulated and associated with prognosis in most tumors. In general, lower ACSL4 expression shows more beneficial prognosis. The most common genetic alteration of ACSL4 is point mutation. ACSL4 is negatively correlated with DNA methylation levels in most cancers. ACSL4 mutations or hypomethylation are associated with poor prognosis. In addition, ACSL4 is positively correlated with immune infiltration in cancers. ACSL4 and immune infiltration are strongly associated with prognosis in BRCA (Breast invasive carcinoma) and SKCM (Skin Cutaneous Melanoma). ACSL4 mutation caused significant changes of immune infiltration in UCEC (Uterine Corpus Endometrial Carcinoma) and SARC (Sarcoma). ACSL4 may be a promising prognostic biomarker for pan-cancer and is closely associated with immune infiltration in the tumor microenvironment.

Mitochondrial oxidative stress mediated Fe-induced ferroptosis via the NRF2-ARE pathway

Ferroptosis is a regulated form of cell death induced by iron (Fe)-dependent lipid peroxidation. At present, the underlying molecular mechanisms remain elusive. Herein, we hypothesized that mitochondria and the NRF2 (transcription factor nuclear factor E2-related factor 2) are potential mediators of ferroptosis, considering their well-established involvement in the oxidative stress pathway. We found that a high iron diet increased hepatic iron content and promoted glutathione (GSH) depletion, lipid peroxidation and oxidative stress. Dietary iron overload also decreased mRNA and protein expression levels of glutathione peroxidase 4 (GPX4) and cystine-glutamate antiporter (SLC7A11), and increased mRNA and protein expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), which are all markers of ferroptosis. Consistent with ferroptosis, iron overload promoted lipid peroxidation and the generation of mitochondrial reactive oxygen species (ROS), and decreased the mitochondrial membrane potential (MMP). Pre-treatment with deferoxamine mesylate (DFO, an iron chelator) alleviated ROS generation and lipid peroxidation, indicating a causative link between iron overload and lipid peroxidation. Suppression of mitochondrial oxidative stress attenuated ferroptosis. Experiments with HEK293T cells revealed that Fe-induced ferroptosis involved direct inhibition of NRF2 binding to antioxidant response elements (AREs) within the promoters of the gpx4 and slc7a11 genes, which in turn induced transcriptional silencing. In conclusion, our study provided a direct link between mitochondrial oxidative stress and ferroptosis via the NRF2-ARE pathway.

Protein tyrosine phosphatase 1 protects human pancreatic cancer from erastin-induced ferroptosis

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a fatal malignancy due to the lack of early detection method, therapeutic drug and target. We noticed that the expression of Protein Tyrosine Phosphatase Mitochondria1(PTPMT1) is upregulated in PDAC. However, its role in pancreatic cancer remains unknown. MethodsWe first analyzed the expression of PTPMT1 from 50 PDAC patients. Secondly, the survival proportions of different PTPMT1-expressed patients were analyzed. Then, the role and mechanism of PTPMT1 in PDAC were studied by lentivirus transduction system. ResultsPTPMT1 was upregulated in PDAC and patients with high PTPMT1 expression displayed lower overall survival rate. Knockdown of PTPMT1 increased the sensitivity to erastin or RSL3 induced ferroptosis. Mechanically, knockdown of PTPMT1 resulted in upregulated Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) and downregulated Solute Carrier Family 7 Member 11 (SLC7A11). In addition, SLC7A11 was upregulated in PDAC tumor tissue and correlated positively with the expression of PTPMT1. However, the expression of ACSL4 was downregulated in PDAC and negatively correlated with the expression of PTPMT1. ConclusionOur study demonstrates that PTPMT1 is upregulated in PDAC and PTPMT1 inhibits ferroptosis by suppressing the expression of ACSL4 and upregulating SLC7A11 in Panc-1 cells, suggesting PTPMT1 might be a potential prognosis biomarker and therapeutic target in PDAC.

ACSL4 Directs Intramuscular Adipogenesis and Fatty Acid Composition in Pigs.

Simple SummaryIn the livestock industry, intramuscular fat content is an important indicator of the meat quality of domestic animals. The variations of the Acyl-CoA Synthetase Long-Chain Family Member 4 (ACSL4) gene locus are associated with intramuscular fat content in different pig populations, but the detailed molecular function of ACSL4 in pig intramuscular adipogenesis remains obscure. Our study reveals the function of ACSL4 in pig intramuscular adipogenesis and provides new clues for improving the palatability of meat and enhancing the nutritional value of pork for human health.The intramuscular fat is a major quality trait of meat, affecting sensory attributes such as flavor and texture. Several previous GWAS studies identified Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) gene as the candidate gene to regulate intramuscular fat content in different pig populations, but the underlying molecular function of ACSL4 in adipogenesis within pig skeletal muscle is not fully investigated. In this study, we isolated porcine endogenous intramuscular adipocyte progenitors and performed ACSL4 loss- and gain-of-function experiments during adipogenic differentiation. Our data showed that ACSL4 is a positive regulator of adipogenesis in intramuscular fat cells isolated from pigs. More interestingly, the enhanced expression of ACSL4 in pig intramuscular adipocytes could increase the cellular content of monounsaturated and polyunsaturated fatty acids, such as gamma-L eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA). The above results not only confirmed the function of ACSL4 in pig intramuscular adipogenesis and meat quality attributes, but also provided new clues for the improvement of the nutritional value of pork for human health.

Lipidome changes due to accumulation of cholesterol via APP‐C99 alters neuronal permeability

γ-secretase activity is enriched at mitochondria-associated ER membranes (MAMs),a lipid-raft subdomain of the ER, where APP fragment C99 is delivered for its cleavage. Moreover, γ-secretase activity deficiency linked to AD mutations causes C99 accumulation at MAM, resulting in the upregulation of MAM activities such as sphingomyelin turnover and cholesterol esterification. We now explore whether the interaction of C99 with cholesterol could explain the link between C99 accumulation at MAM and the lipid abnormalities found in AD. Using cellular models of C99 accumulation versus a cholesterol-binding deficient C99, we assessed cholesterol uptake dynamics and sub-cellular distribution along with MAM-regulated functionalities. Also, we used a photo click activable cholesterol analog to study the proteins interacting with cholesterol at MAM in both conditions. Finally, we compare membrane permeability dynamics in neuronal models of Alzheimer's disease. C99 accumulation at MAM caused an increase in cholesterol uptake, cholesterol esterification, phospholipid synthesis and sphingomyelinase activity accompanied by a sub cellular redistribution of cholesterol to endolysosomes and ER, while C99-defective in cholesterol binding showed no changes in these activities. Moreover, when the cholesterol-interacting proteome of both conditions was compared, C99 caused a huge change/recruitment at MAM, especially of enzymes involved in lipid metabolism. ACSL4 (Acyl-CoA Synthetase Long Chain Family Member 4) activation was detected as an important player in the lipidome changes associated with C99 accumulation that led to membrane permeability alterations CONCLUSION: We report that the lipid alterations caused by pathogenic C99 accumulation are a consequence of an exacerbated uptake of extracellular cholesterol and mobilization towards MAM. The increase content of cholesterol at MAM driven by C99 might be responsible of the persistent activation of MAM and a subsequent alteration of the lipid metabolism since a cholesterol-binding deficient C99 fails to increase MAM activities and cholesterol trafficking. We also point to ACSL4 activation as a possible molecular switch for the permeability changes found in cellular models of AD.

Inhibiting ACSL1-Related Ferroptosis Restrains Murine Coronavirus Infection.

Murine hepatitis virus strain A59 (MHV-A59) was shown to induce pyroptosis, apoptosis, and necroptosis of infected cells, especially in the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59 is unknown. We utilized murine macrophages and a C57BL/6 mice intranasal infection model to address this. In primary macrophages, the ferroptosis inhibitor inhibited viral propagation, inflammatory cytokines released, and cell syncytia formed after MHV-A59 infection. In the mouse model, we found that in vivo administration of liproxstatin-1 ameliorated lung inflammation and tissue injuries caused by MHV-A59 infection. To find how MHV-A59 infection influenced the expression of ferroptosis-related genes, we performed RNA-seq in primary macrophages and found that MHV-A59 infection upregulates the expression of the acyl-CoA synthetase long-chain family member 1 (ACSL1), a novel ferroptosis inducer. Using ferroptosis inhibitors and a TLR4 inhibitor, we showed that MHV-A59 resulted in the NF-kB-dependent, TLR4-independent ACSL1 upregulation. Accordingly, ACSL1 inhibitor Triacsin C suppressed MHV-A59-infection-induced syncytia formation and viral propagation in primary macrophages. Collectively, our study indicates that ferroptosis inhibition protects hosts from MHV-A59 infection. Targeting ferroptosis may serve as a potential treatment approach for dealing with hyper-inflammation induced by coronavirus infection.

Lipid droplets contribute myogenic differentiation in C2C12 by promoting the remodeling of the acstin-filament

Lipid droplet (LD), a multi-functional organelle, is found in most eukaryotic cells. LDs participate in the regulation of many cellular processes including proliferation, stress, and apoptosis. Previous studies showed the athlete’s paradox that trained athletes accumulate LDs in their skeletal muscle. However, the impact of LDs on skeletal muscle and myogenesis is not clear. We discovered that C2C12 myoblast cells containing more LDs formed more multinucleated muscle fibers. We also discovered that LDs promoted cell migration and fusion by promoting actin-filaments remodeling. Mechanistically, two LD-proteins, Acyl-CoA synthetase long chain family member 3 (ACSL3) and lysophosphatidylcholine acyltransferase 1 (LPCAT1), medicated the recruitment of actinin proteins which contributed to actin-filaments formation on the surface of LDs. During remodeling, the actinin proteins on LDs surface translocated to actin-filaments via ARF1/COPI vesicles. Our study demonstrate LDs contribute to cell differentiation, which lead to new insight into the LD function.

Activation of pyroptosis and ferroptosis is involved in the hepatotoxicity induced by polystyrene microplastics in mice

Microplastics (MPs) are new environmental pollutants and have received widespread attention in recent years, but the toxicity of the MPs remains to be fully elucidated. To explore the effect of MPs on hepatotoxicity in mice and unravel the mechanism of pyroptosis and ferroptosis in the process of liver injury, we treated mice with 5.0 μm polypropylene microplastics (MPs) at 0.1, 0.5 and 1 mg/mL for 4 weeks. Results revealed that MPs could damage liver structure and function with broken and reduced mitochondrial cristae, as well as increased levels of aspartate minotransferase (AST), alanine aminotransferase (ALT), AST/ALT, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Treatment with MPs resulted in pyroptosis as evidenced by increasing expressions of interleukin IL-1β, IL-18. Additionally, MPs were shown to induce the NOD-like receptor protein 3 (NLRP3) inflammasomes and apoptosis associated speck-like protein (ASC) containing a caspase recruitment domain activation in liver tissue, enabling activation of Caspase-1-dependent signaling pathway induced by inflammatory stimuli resulting from oxidative stress. In addition, the increase of malondialdehyde (MDA) and decrease of glutathione (GSH) and superoxide dismutase (SOD) in the liver indicated that MPs could induce oxidative damage. Moreover, MPs induced lipid peroxidation in the liver of mice could activate the expression of ferroptosis related proteins, including iron metabolism, such as transferrin receptor (TFRC) was active but ferritin heavy chain 1 (FTH1) was inhibited; amino acid metabolism, such as XCT system and glutathione peroxidase 4 (GPX4) were inhibited; lipid metabolism, such as acyl-CoA synthetase long-chain family member 4 (ACSL4) was inhibited. Collectively, these findings evidenced that pyroptosis and ferroptosis occurred in MPs-induced liver injury accompanied by intense oxidative stress and inflammation.

Inhibition of keratinocyte ferroptosis suppresses psoriatic inflammation

Psoriasis is a common, chronic, and recurrent inflammatory disease. It is characterized by hyperproliferation and abnormal differentiation of keratinocytes. Keratinocyte death is also involved in many pathophysiological conditions and amplifies the inflammatory cascade. As a newly recognized form of cell death, ferroptosis is involved in several inflammatory diseases. In this study, we aimed to investigate a previously unrecognized role for ferroptosis in psoriasis. Ferroptosis is mediated by lipid peroxidation and iron overload. Compared with normal lesions, the mRNA expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), prostaglandin-endoperoxide synthase 2 (PTGS2), and transferrin receptor (TFRC) were highly expressed in psoriatic lesions, with decreased levels of glutathione peroxidase 4 (GPX4), ferritin light chain (FTL), and ferritin heavy chain 1 (FTH1). The protein levels of ACSL4 and GPX4 were consistent with their mRNA levels. A similar tendency of ferroptosis was also observed in erastin-treated human primary keratinocytes and the Imiquimod (IMQ)-induced model of psoriasis. To investigate the correlation between inflammation and peroxidation, we analyzed single-cell RNA-sequencing data and identified 15 cell types. There was a high correlation between the activity of the lipid oxidation and the Th22/Th17 response in keratinocytes at a single-cell level. Moreover, ferrostatin-1 (Fer-1), a potent inhibitor of lipid peroxidation, suppressed ferroptosis-related changes in erastin-treated keratinocytes and alleviated psoriasiform dermatitis of IMQ-induced models. Additionally, Fer-1 blocked inflammatory responses in vitro and in vivo, reducing the production of cytokines including TNF-α, IL-6, IL-1α, IL-1β, IL-17, IL-22, and IL-23. This study revealed an expression pattern of ferroptosis in which specific molecules enhance inflammatory reactions in psoriasis.

Environmental allergens house dust mite-induced asthma is associated with ferroptosis in the lungs.

Previous studies have indicated that allergens such as house dust mites (HDM) in the environment can induce allergic asthma. Ferroptosis is a newly discovered form of regulatory cell death characterized by aberrant lipid peroxidation and the accumulation of reactive oxygen species (ROS) in cells. However, whether ferroptosis participates in the pathological process of asthma remains to be elucidated. The present study used a HDM-induced mouse asthma model to determine the effect of HDM exposure on allergic asthma and its underlying mechanisms. Female BALB/c mice were intranasally exposed to HDM to induce allergic asthma. Airway hyperresponsiveness (AHR), lung inflammation, mucus secretion, IgE levels, cytokine levels and inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were investigated. In addition, the morphological changes of mitochondria, ROS levels, glutathione (GSH) levels and changes in ferroptosis pathway proteins were also determined in murine lungs. As a result, HDM exposure significantly increased AHR, inflammatory cell infiltration and mucus secretion around the airways. Furthermore, elevated IgE levels in the BALF, lung eosinophilia and a concomitant increase in IL-13 and IL-5 levels in BALF were observed. HDM inhalation increased ROS and decreased GSH levels in the lungs. HDM inhalation induced dysmorphic small mitochondria with decreased crista, as well as condensed, ruptured outer membranes. Western blotting demonstrated that the activities of glutathione peroxidase 4 and catalytic subunit solute carrier family 7 member 11 were significantly decreased, and that protein expression levels of acyl-CoA synthetase long-chain family member 4 and 15 lipoxygenase 1 were upregulated compared with mice in the normal control group. Overall, these results indicated that the AHR, airway inflammation, lipid peroxidation and ROS levels increased in HDM-induced asthma, and that HDM inhalation induced ferroptosis in the lungs, which helped to form an improved understanding of the pathogenesis of allergic asthma.

Multi-Omics Integration to Reveal the Mechanism of Hepatotoxicity Induced by Dictamnine.

Herb-induced liver injury (HILI) has become a great concern worldwide due to the widespread usage of herbal products. Among these products is Dictamni Cortex (DC), a well-known Traditional Chinese Medicine (TCM), widely used to treat chronic dermatosis. Dictamni Cortex has drawn increasing attention because of its hepatotoxicity caused by the hepatotoxic component, dictamnine. However, the potential hepatotoxicity mechanism of dictamnine remains unclear. Therefore, this study aimed to use the multi-omics approach (transcriptomic, metabolomic, and proteomic analyses) to identify genes, metabolites, and proteins expressions associated with dictamnine-induced hepatotoxicity. A study on mice revealed that a high dose of dictamnine significantly increases serum aspartate aminotransferase (AST) activity, total bilirubin (TBIL), and direct bilirubin (DBIL) levels, the relative liver weight and liver/brain weight ratio in female mice (P < 0.05 and P < 0.01), compared to the normal control group. Liver histologic analysis further revealed a high dose of dictamnine on female mice caused hepatocyte vesicular steatosis characterized by hepatocyte microvesicles around the liver lobules. The expressed genes, proteins, and metabolites exhibited strong associations with lipid metabolism disorder and oxidative stress. Dictamnine caused increased oxidative stress and early hepatic apoptosis via up-regulation of glutathione S transferase a1 (GSTA1) and Bax/Bcl-2 ratio and down-regulation of the antioxidative enzymes superoxide dismutase (SOD), catalase, and glutathione peroxidase 1 (GPx-1). Besides, the up-regulation of Acyl-CoA synthetase long-chain family member 4 (ACSL4) and down-regulation of acetyl-coa acetyltransferase 1 (ACAT1) and fatty acid binding protein 1 (FABP-1) proteins were linked to lipid metabolism disorder. In summary, dictamnine induces dose-dependent hepatotoxicity in mice, which impairs lipid metabolism and aggravates oxidative stress.

Ferroptosis is involved in the anti-tumor effect of lycorine in renal cell carcinoma cells.

Renal cell carcinoma (RCC) is a most common malignant tumor in the genitourinary system. Studies have shown that Lycorine has promising anticancer activities with minor side effects. However, the effect of lycorine on the proliferation of RCC cells and its underlying anti-tumor mechanism have not yet been fully elucidated. The human renal cancer cell lines 786-O, A498 and Caki-1 were cultured and treated with different concentrations of lycorine or ferrostatin-1, a ferroptosis inhibitor. Cell viability and colony formation assays were used to measure cell proliferation. The 5-, 12- and 15-HETE hydroxyeicosatetraenoic acid (HETE) and MDA levels, as well as the reduced to oxidized glutathione (GHS/GSSG) ratio, were analyzed. Western blot analysis was used to detect the expression of glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long chain family member 4 (ACSL4), which are key markers of ferroptosis. Transmission electron microscopy was used to observe the morphological features associated with ferroptosis. Lycorine was found to inhibit the proliferation of RCC cells. After lycorine treatment, the expression levels of GPX4 in RCC cells decreased, whereas those of ACSL4 increased. Lycorine induced the expression of 5-HETE, 12-HETE, 15-HETE and MDA in RCC cells, and reduced the GSH/GSSG ratio. In addition, ferrostatin-1 could prevent lycorine-induced ferroptosis in RCC cells.

The Ferroptosis-NLRP1 Inflammasome: The Vicious Cycle of an Adverse Pregnancy.

One of the hallmarks of placental dysfunction is the increase of oxidative stress. This process, along with the overexpression of the inflammasome, creates a downward spiral that can lead to a series of severe pregnancy complications. Ferroptosis is a form of iron-mediated cell death involving the accumulation of reactive oxygen species, lipid peroxides. In this study, the rats’ model of oxidative stress abortion was established, and hydrogen peroxide (H2O2) was used to establish a cellular model of placental oxidative stress. RNAi, western blot, and immunofluorescence were used to evaluate the expression of specific markers of ferroptosis and the expression of the inflammasome in placental trophoblast cells. We observed excessive levels of ferroptosis and inflammasome activation in both rats’ model and placental trophoblast cell model of oxidative stress. When the NLRP1 inflammasome was silenced, the expression levels of GSH and Glutathione peroxidase 4 (GPX4) were increased, while the expression levels of transferrin receptor 1 (TFR1), acyl-CoA synthetase long-chain family member 4 (ACSL4), Superoxide dismutase (SOD), and Malondialdehyde (MDA) were decreased. However, when an NLRP1 activator was applied, we observed the opposite phenomenon. We further explored the mechanisms underlying the actions of ferroptosis to inflammasomes. The expression levels of NLRP1, NLRP3, IL-1β, and caspase-1 were positively correlated with the ferroptosis following the application of ferroptosis inhibitor (ferrostatin-1) and ferroptosis activator (erastin). The existence of ferroptosis was demonstrated in the oxidative stress model of placental trophoblast cells; the results also indicate ferroptosis is linked with the expression of NLRP1 inflammasome. These findings may provide a valuable therapeutic target for the pathogenesis of pregnancy-related diseases.