HMOX1 Expression Research Articles

IMMU-33. REPROGRAMMING OF MYELOID CELL METABOLISM VIA HEME OXYGENASE-1 INHIBITION POTENTIATES ANTI-TUMOR IMMUNITY IN A MURINE GLIOMA MODEL

Abstract Cancer cells exhibit a preference for aerobic glycolysis, a phenomenon known as the Warburg effect. Emerging evidence suggests that immune cells within the tumor microenvironment (TME) may employ a similar metabolic adaptation. Heme oxygenase-1 (HMOX-1), a metabolic regulatory gene, is elevated in myeloid cells of glioblastoma (GBM), yet its precise role in modulating immune suppression and energy utilization remains unclear. Our objective was to explore how targeting HMOX-1 activity in the GBM TME affects immune response and energy metabolism. We utilized syngeneic glioma models with C57BL/6J mice implanted with CT-2A cells, which were randomized into four treatment arms: intracranial (IC) injection of the HMOX-1 inhibitor zinc protoporphyrin (ZnPP), intraperitoneal (IP) injection of anti-PD-1, IC ZnPP + IP anti-PD-1, or IC saline (sham). For mechanistic studies, we developed a myeloid-specific knockdown model via adoptive cell transfer of myeloid-derived suppressor cells (MDSCs) transfected with Hmox-1 siRNA into CSF-1R myeloid-depleted mice. Immunophenotyping was conducted with flow cytometry. The Seahorse mitochondrial stress test was used for evaluation of energy dynamics. Downregulation of myeloid Hmox-1 expression and inhibition of HMOX-1 via ZnPP both led to heightened T cell activation, with increased IFN-γ expression in brain compared to untreated mice (P=0.039, 0.02, respectively). Notably, ZnPP treatment induced a compensatory elevation of PD-L1 in myeloid cells (P<0.0001). Both ZnPP monotherapy and anti-PD-1 + ZnPP combination therapy demonstrated enhanced median overall survival rates in comparison to sham and anti-PD-1 monotherapy groups, with the combined approach yielding the most significant survival advantage (P<0.0001). Metabolic analyses following Hmox-1 knockdown and ZnPP treatment revealed a shift away from cancer-like glycolytic shunting in MDSCs. Inhibiting the HMOX-1 pathway facilitated T cell activation and reversal of glycolysis-predominant metabolism in MDSCs, resulting in improved survival outcomes in a murine glioma model. Modulation of metabolic reprogramming in myeloid cells may potentiate anti-tumor immunity, especially in conjunction with checkpoint blockade.

Gene expression responses of CF airway epithelial cells exposed to elexacaftor/tezacaftor/ivacaftor (ETI) suggest benefits beyond improved CFTR channel function.

The combination of elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) reverses the primary defect in Cystic Fibrosis (CF) by improving CFTR mediated Cl- and HCO3- secretion by airway epithelial cells (AEC), leading to improved lung function and less frequent exacerbations and hospitalizations. However, studies have shown that CFTR modulators like ivacaftor, a component of ETI, has numerous effects on CF cells beyond improved CFTR channel function. Because little is known about the effect of ETI on CF AEC gene expression we exposed primary human AEC to ETI for 48 hours and interrogated the transcriptome by RNA-seq and qPCR. ETI increased CFTR Cl- secretion, and defensin gene expression (DEFB1) an observation consistent with reports of decreased bacterial burden in the lungs of people with CF (pwCF). ETI decreased MMP10 and MMP12 gene expression, suggesting that ETI may reduce proteolytic induced lung destruction in CF. ETI also reduced the expression of the stress response gene heme oxygenase (HMOX1). qPCR analysis confirmed DEFB1, HMOX1, MMP10 and MMP12 gene expression results observed by RNA-seq. Gene pathway analysis revealed that ETI decreased inflammatory signaling, cellular proliferation and MHC Class II antigen presentation. Collectively, these findings suggest that the clinical observation that ETI reduces lung infections in pwCF is related in part to drug induced increases in DEFB1, and that ETI may reduce lung damage by reducing MMP10 and MMP12 gene expression. Moreover, pathway analysis also identified several other genes responsible for the ETI induced reduction in inflammation observed in pwCF.

Vitamin U alleviates AFB1-induced hepatotoxicity in pregnant and lactating mice by regulating the Nrf2/Hmox1 pathway

This study investigated the protective effect of Vitamin U on liver injury induced by aflatoxin B1 (AFB1) in maternal mice. 25 pregnant ICR mice were randomly divided into five groups: the AFB1 group (AF, 0.3 mg AFB1/kg b.w.), the Vitamin U group (U, 50 mg Vitamin U/kg b.w.), the AFB1 + Vitamin U group (AU, 50 mg Vitamin U /kg b.w. + 0.3 mg AFB1/kg b.w.), the control group (DMSO), and the MOCK group (distilled water). They were administered substances by gavage every day for 28 days. Results indicated that exposure to AFB1 increased the liver index and caused histological disruptions. Elevated serum levels of ALT and ALP were observed, along with a significant increase in liver MDA content and a decrease in GSH-Px and T-SOD levels. Moreover, the Keap1 and Hmox1 gene was downregulated with statistical significance, while the IL1β and TNFα gene were significantly upregulated. Vitamin U was demonstrated by the organized structure of liver cells in tissue slices, effectively reducing liver cell necrosis. This intervention was associated with a significant decrease in serum ALT and ALP activities, as well as a significant decrease in liver MDA content. Additionally, there were significant increases in liver T-SOD and GSH-Px levels, along with upregulation of mRNA and protein expression of Nfr2, Hmox1 and Keap1, and downregulation of mRNA expression of the IL1β gene. In summary, Vitamin U mitigated oxidative stress-induced liver injury by modulating the Nrf2/Hmox1 signaling pathway and inflammatory factors affected by AFB1.

Angelica sinensis polysaccharides ameliorate 5-FU-induced stress anemia via promoting extramedullary erythroblastic island central macrophage-mediated erythroid differentiation

BackgroundChronic anemia, especially chemotherapy-induced anemia, is a common and intractable symptom. Puzzlingly, the conventional anemic treatment may lead to various side effects, and the mechanism of stress anemia remains unclear. MethodsHere, peripheral blood, histopathological and transmission electron microscopical examination, colony forming test, flow cytometry, and qRT-PCR assay were used to investigate the effects of Angelia sinensis polysaccharide (ASP), one main active ingredient of Chinese herb medicine Angelica sinensis, on ameliorating 5-fluorouracil (5-FU)-induced stress anemia. ResultsWe found that intraperitoneal injection to a C57BL/6J mouse ASP 100 mg/kg per day for consecutive 10 days or 14 days, remarkably accelerated the recovery of RBC, hemoglobin, and hematocrit in blood. ASP alleviated 5-FU-caused impairment of bone marrow cell and BFU-E enumeration. Meanwhile, ASP antagonized 5-FU promoting extramedullary erythropoiesis in the spleen, inducing splenomegaly due to stress erythroblastic islands, and occurrence of megakaryocytes and hematopoietic precursors in splenic colonies. ASP increased splenic stress BFU-E enumeration, driving BFU-E differentiation towards Pro-E and end-stage erythroblasts. Furthermore, ASP increased the number of F4/80+VCAM-1+ splenic erythroblastic island central macrophages, upregulating genetic expression of EPOR, Emp, VCAM-1, Hmox-1, Trf, TfR1, Fpn1, Spi-C, DNase2a, Tim4, MertK, and Klf1 in splenocytes. ConclusionsOur findings indicate that the possible mechanism of chemotherapy-induced anemia is related to stress erythroid maturation arrest. Whereas, ASP may promote stress erythroid differentiation via elevated EPO sensitivity in extramedullary hematopoietic organs and enhanced macrophage-mediated adhesion, iron homeostasis and transfer, and nuclear engulfment, which may represent a promising therapeutic strategy.

High expression levels of haem oxygenase-1 promote ferroptosis in macrophage-derived foam cells and exacerbate plaque instability

Plaque rupture with consequent thrombosis is the leading cause of acute cardiovascular events, during which macrophage death is a hallmark. Ferroptosis is a pivotal intermediate link between early and advanced atherosclerosis. Existing evidence indicates the involvement of macrophage ferroptosis in plaque vulnerability; however, the exact mechanism remains elusive. The aim of this study was to explore key ferroptosis-related genes (FRGs) involved in plaque progression and the underlying molecular mechanisms involved. The expression landscape of FRGs was obtained from atherosclerosis-related GEO datasets. Molecular mechanism studies of ferroptosis were performed using bone marrow-derived macrophages (BMDMs) and macrophage-derived foam cells (MDFCs). Bioinformatics analysis and immunohistochemistry revealed that macrophage haem oxygenase-1 (HMOX1) is the key FRG involved in plaque destabilization. Hypoxic conditions induced a significant increase in Hmox1 expression in MDFCs but not in macrophages. In addition, the beneficial or deleterious effects of Hmox1 were dependent on the degree of Hmox1 induction. Hmox1 overexpression drove inflammatory responses and ferroptotic oxidative stress in MDFCs and aggravated the plaque burden in atherosclerotic model mice. Further mechanistic investigations demonstrated that hypoxia-mediated degradation of egl-9 family hypoxia-inducible factor 3 (Egln3) stabilized Hif1a, which subsequently promoted Hmox1 transcription. Our findings suggest that high Hmox1 expression under hypoxia is deleterious to MDFC viability and plaque stability, providing a reference for the management of acute cardiovascular events.

Fine particulate matter potentiates Th17-cell pathogenicity in experimental autoimmune uveitis via ferroptosis

The effect of fine particulate matter (PM2.5) on the development of uveitis remains unclear. Therefore, this study was designed to investigate the role of PM2.5 in experimental autoimmune uveitis (EAU) and its potential mechanism. Our results showed that PM2.5 could exacerbate the activity of EAU, as evidenced by severer clinical and pathological changes, correlated with elevated Th17 cells frequency and IL-17A expression. Proteomic analysis revealed ferroptosis was the most significant pathway. In vivo, the levels of Fe2+, ROS, lipid ROS, and malondialdehyde, as well as the expression of TFRC, HMOX1, FTH1, and FTL1 in CD4+ T cells were increased, while GSH/GSSG ratio and the expression of ACSL1 and GPX4 were decreased after PM2.5 exposure. In vitro, the expression of TFRC and HMOX1 were increased, while the expression FTH1, FTL1, ACSL1, and GPX4 were decreased after PM2.5 exposure. Ferrostatin-1 effectively alleviated PM2.5-induced intraocular inflammation and suppressed the frequency of Th17 cells. These results suggest that PM2.5 could aggravate intraocular inflammation and immune response in EAU mice through ferroptosis. Ferroptosis could be a potential marker for the prevention and treatment of uveitis.

Network Pharmacology and Experimental Analysis to Explore the Effect and Mechanism of Modified Buyang Huanwu Decoction in the Treatment of Diabetic Nephropathy.

Preventing and treating diabetic nephropathy (DN) are global challenges due to the complexity and diversity of its causes and manifestations. It is important to find effective medications to treat DN. Gene expression files of DN were downloaded from the GEO database to identify the differentially expressed genes. Network pharmacology and molecular docking were used to explore the possible mechanisms of modified Buyang Huanwu Decoction (mBHD) in treating DN. Biochemical, histopathological, and real-time PCR analyses were conducted in both in vivo and in vitro DN models to investigate the effects of mBHD. A total of 336 active ingredients and 124 potential targets of mBHD associated with DN were identified. Among them, 8 hub genes were found to be important targets for mBHD in treating DN and were significantly correlated with the infiltration status of six immune cells. Partially, the active ingredients of mBHD demonstrated good stability in binding to CASP3 and TP53. mBHD treatment significantly reduced levels of total cholesterol, triglyceride, blood urea nitrogen, serum creatinine, and microalbumin in db/db mice. HE and Masson's staining results showed that mBHD attenuated renal injury in db/db mice. Additionally, mBHD treatment could significantly alter the expression of CASP3, CCL2, TP53, ALB, and HMOX1. mBHD may be involved in the treatment of DN through multiple ingredients, targets, and pathways. In addition, mBHD could alleviate renal injury in db/db mice, possibly involving CASP3, CCL2, TP53, ALB, and HMOX1.

Shenqi Sanjie Granules induce Hmox1-mediated ferroptosis to inhibit colorectal cancer

BackgroundBecause adverse reactions or drug resistance are often found after current chemotherapies for metastatic colorectal cancer (mCRC), new treatments are still in demand. Shenqi Sanjie Granules (SSG), an antitumor compound preparation of traditional Chinese medicine, has been recognized for its ability in clinical practice of oncotherapy. Nevertheless, the precise effects of SSG in colorectal cancer (CRC) and underlying mechanisms through which SSG inhibits CRC remain uncertain. The current study aimed to evaluate the anti-CRC activity of the Chinese herbal compound preparation SSG and investigate the underlying mechanisms of action. Materials and methodsInitially, nine distinct cancer cell lines, including five CRC cell lines, one breast cancer cell line, two lung adenocarcinoma cell lines and one cervical cancer cell line, were used to evaluate the antitumor activity of SSG, and the mouse CRC cell line CT26 were used for further research. In vitro experiments utilizing diverse assays were conducted to assess the inhibitory effects of the SSG on CT26. Furthermore, subcutaneous syngeneic mouse model and AOM (azoxymethane)/DSS (dextran sodium sulfate) induced in-situ colitis-related mouse CRC model were used to evaluate the antitumor potential and biotoxicity of SSG in vivo. To elucidate the underlying molecular mechanisms, transcriptome sequencing and network pharmacology analysis were performed. Meanwhile, verification is carried out with quantitative real-time PCR (qRT-PCR) and flow cytometry (FCM) analysis. ResultsOur in vitro inhibition study showed that SSG could effectively inhibit CRC cell line CT26 growth and metastasis, and induce cell death. Neither of apoptosis inhibitor, necroptosis inhibitor, ferroptosis inhibitor, but the combination of the three diminished SSG-induced cell death, suggesting that multiple cell death pathways were involved. Both the syngeneic CRC model and the in-situ CRC model indicated SSG inhibited CRC in vivo with few toxic side effects. Further mechanistic study suggested SSG treatment activated the ferroptosis pathway, particularly mediated by Hmox1, which was upregulated scores of times. Network pharmacology analysis indicated that the active ingredients of SSG, including Quercetin, Luteolin and Kaempferol were potential components directly upregulated Hmox1 expression. ConclusionsCollectively, our findings indicate that the administration of SSG has the potential to inhibit CRC both in vitro and in vivo. The mechanism by which this compound preparation exerts its action is, at least partly, the induction of ferroptosis through upregulating Hmox-1 by its three active ingredients Quercetin, Luteolin and Kaempferol.

Bioinformatics and validation reveal the potential target of curcumin in the treatment of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common nerve-damaging complication of diabetes mellitus. Effective treatments are needed to alleviate and reverse diabetes-associated damage to the peripheral nerves. Curcumin is an effective neuroprotectant that plays a protective role in DPN promoted by Schwann cells (SCs) lesions. However, the potential molecular mechanism of curcumin remains unclear. Therefore, our aim is to study the detailed molecular mechanism of curcumin-mediated SCs repair in order to improve the efficacy of curcumin in the clinical treatment of DPN. First, candidate target genes of curcumin in rat SC line RSC96 cells stimulated by high glucose were identified by RNA sequencing and bioinformatic analyses. Enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) was carried out by Metascape, followed by 8 algorithms on Cytoscape to determine 4 hub genes, namly Hmox1, Pten, Vegfa and Myc. Next, gene set enrichment analysis (GSEA) and Pearson function showed that Hmox1 was significantly correlated with apoptosis. Subsequently, qRT-PCR, MTT assay, flow cytometry, caspase-3 activity detection and westernblot showed that curcumin treatment increased RSC96 cell viability, reduced cell apoptosis, increased Hmox1, Pten, Vegfa and Myc expression, and up-regulated Akt phosphorylation level under high glucose environment. Finally, molecular docking predicted the binding site of curcumin to Hmox1. These results suggest that curcumin can reduce the apoptosis of SCs induced by high glucose, and Hmox1 is a potential target for curcumin. Our findings provide new insights about the mechanism of action of curcumin on SC as a potential treatment in DPN.

Integrated transcriptomics- and structure-based drug repositioning identifies drugs with proteasome inhibitor properties

Computational pharmacogenomics can potentially identify new indications for already approved drugs and pinpoint compounds with similar mechanism-of-action. Here, we used an integrated drug repositioning approach based on transcriptomics data and structure-based virtual screening to identify compounds with gene signatures similar to three known proteasome inhibitors (PIs; bortezomib, MG-132, and MLN-2238). In vitro validation of candidate compounds was then performed to assess proteasomal proteolytic activity, accumulation of ubiquitinated proteins, cell viability, and drug-induced expression in A375 melanoma and MCF7 breast cancer cells. Using this approach, we identified six compounds with PI properties ((-)-kinetin-riboside, manumycin-A, puromycin dihydrochloride, resistomycin, tegaserod maleate, and thapsigargin). Although the docking scores pinpointed their ability to bind to the β5 subunit, our in vitro study revealed that these compounds inhibited the β1, β2, and β5 catalytic sites to some extent. As shown with bortezomib, only manumycin-A, puromycin dihydrochloride, and tegaserod maleate resulted in excessive accumulation of ubiquitinated proteins and elevated HMOX1 expression. Taken together, our integrated drug repositioning approach and subsequent in vitro validation studies identified six compounds demonstrating properties similar to proteasome inhibitors.

Exploring the potency of polyphenol-rich blend from Lonicera caerulea var. Kamtschatica sevast., Aronia melanocarpa, and Echinacea purpurea: Promising anti-inflammatory, antioxidant, and antiviral properties

Previous studies have highlighted the beneficial properties of plants rich in polyphenols, such as Lonicera caerulea var. Kamtschatica Sevast. (LCK), Aronia melanocarpa (AM), and Echinacea purpurea (EP). These plants have demonstrated antioxidant, immunomodulatory, and potential antiviral effects. Thus, the objective of this study was to investigate the impact of the ELA blend, a polyphenol-rich blend containing EP, LCK, and AM, on the cellular mechanisms involved in viral infection. To assess the effects of the ELA blend, various experiments were conducted using A549 cells and a mucociliary tissue 3D model called EpiAirway™. Inflammation and oxidative stress induced by LPS were evaluated through measurements of SOD activity, ELISA, and qPCR analysis. Additionally, antiviral assays were performed in a cell-present environment to examine the blend's effectiveness against HCoV-OC43. The results showed that the ELA blend-treated group exhibited reduced expression of IL1B, CXCL8, ICAM1, MCP1, and RELA in both A549 cells and EpiAirway™. Moreover, the blend enhanced the expression of CAT, HMOX1, SOD1, and SOD2 in A549 cells. The antiviral activity of the ELA blend was also investigated, i.e. its influence on viral replication cycle, to determine the potential as an antiviral preparation. At the highest non-cytotoxic concentration, the ELA blend demonstrated a 87.5 % reduction in viral titer when administered simultaneously with HCoV-OC43. It emphasize potential ability of the preparation to block viral entry to the host cells. At the same time, ELA blend did not express virucidal activity, i.e. inactivation of free viral particles, against HCoV-OC43. In conclusion, ELA blend displayed antiviral activity and exhibited immunomodulatory and antioxidant effects. Based on these findings, it can be concluded that ELA blend has potential for the prevention and treatment of viral infections.

Artesunate induces melanoma cell ferroptosis and augments antitumor immunity through targeting Ido1

Artesunate (ART), a natural product isolated from traditional Chinese plant Artemisia annua, has not been extensively explored for its anti-melanoma properties. In our study, we found that ART inhibited melanoma cell proliferation and induced melanoma cell ferroptosis. Mechanistic study revealed that ART directly targets Ido1, thereby suppressing Hic1-mediated transcription suppression of Hmox1, resulting in melanoma cell ferroptosis. In CD8+ T cells, ART does not cause cell ferroptosis due to the low expression of Hmox1. It also targets Ido1, elevating tryptophan levels, which inhibits NFATc1-mediated PD1 transcription, consequently activating CD8+ T cells. Our study uncovered a potent and synergistic anti-melanoma efficacy arising from ART-induced melanoma cell ferroptosis and concurrently enhancing CD8+ T cell-mediated immune response both in vivo and in vitro through directly targeting Ido1. Our study provides a novel mechanistic basis for the utilization of ART as an Ido1 inhibitor and application in clinical melanoma treatment.

Aerosol exposure at air-liquid-interface (AE-ALI) in vitro toxicity system characterisation: Particle deposition and the importance of air control responses

Experimental systems allowing aerosol exposure (AE) of cell cultures at the air-liquid-interface (ALI) are increasingly being used to assess the toxicity of inhaled contaminants as they are more biomimetic than standard methods using submerged cultures, however, they require detailed characterisation before use. An AE-ALI system combining aerosol generation with a CULTEX® exposure chamber was characterised with respect to particle deposition and the cellular effects of filtered air (typical control) exposures. The effect of system parameters (electrostatic precipitator voltage, air flowrate to cells and insert size) on deposition efficiency and spatial distribution were investigated using ICP-MS and laser ablation ICP-MS, for an aerosol of CeO2 nanoparticles. Deposition varied with conditions, but appropriate choice of operating parameters produced broadly uniform deposition at suitable levels. The impact of air exposure duration on alveolar cells (A549) and primary small airway epithelial cells (SAECs) was explored with respect to LDH release and expression of selected genes. Results indicated that air exposures could have a significant impact on cells (e.g., cytotoxicity and expression of genes, including CXCL1, HMOX1, and SPP1) at relatively short durations (from 10 mins) and that SAECs were more sensitive. These findings indicate that detailed system characterisation is essential to ensure meaningful results.

Transcriptional coactivation of NRF2 signaling in cardiac fibroblasts promotes resistance to oxidative stress

We recently discovered that steroid receptor coactivators (SRCs) SRCs-1, 2 and 3, are abundantly expressed in cardiac fibroblasts (CFs) and their activation with the SRC small molecule stimulator MCB-613 improves cardiac function and dramatically lowers pro-fibrotic signaling in CFs post-myocardial infarction. These findings suggest that CF-derived SRC activation could be beneficial in the mitigation of chronic heart failure after ischemic insult. However, the cardioprotective mechanisms by which CFs contribute to cardiac pathological remodeling are unclear. Here we present studies designed to identify the molecular and cellular circuitry that governs the anti-fibrotic effects of an MCB-613 derivative, MCB-613-10-1, in CFs. We performed cytokine profiling and whole transcriptome and proteome analyses of CF-derived signals in response to MCB-613-10-1. We identified the NRF2 pathway as a direct MCB-613-10-1 therapeutic target for promoting resistance to oxidative stress in CFs. We show that MCB-613-10-1 promotes cell survival of anti-fibrotic CFs exposed to oxidative stress by suppressing apoptosis. We demonstrate that an increase in HMOX1 expression contributes to CF resistance to oxidative stress-mediated apoptosis via a mechanism involving SRC co-activation of NRF2, hence reducing inflammation and fibrosis. We provide evidence that MCB-613-10-1 acts as a protectant against oxidative stress-induced mitochondrial damage. Our data reveal that SRC stimulation of the NRF2 transcriptional network promotes resistance to oxidative stress and highlights a mechanistic approach toward addressing pathologic cardiac remodeling.

Ribonuclease inhibitor 1 emerges as a potential biomarker and modulates inflammation and iron homeostasis in sepsis

Sepsis, marked by organ dysfunction, necessitates reliable biomarkers. Ribonuclease inhibitor 1 (RNH1), a ribonuclease (RNase) inhibitor, emerged as a potential biomarker for acute kidney injury and mortality in thoracoabdominal aortic aneurysm patients. Our study investigates RNH1 dynamics in sepsis, its links to mortality and organ dysfunction, and the interplay with RNase 1 and RNase 5. Furthermore, we explore RNH1 as a therapeutic target in sepsis-related processes like inflammation, non-canonical inflammasome activation, and iron homeostasis. We showed that RNH1 levels are significantly higher in deceased patients compared to sepsis survivors and correlate with creatine kinase, aspartate and alanine transaminase, bilirubin, serum creatinine and RNase 5, but not RNase 1. RNH1 mitigated LPS-induced TNFα and RNase 5 secretion, and relative mRNA expression of ferroptosis-associated genes HMOX1, FTH1 and HAMP in PBMCs. Monocytes were identified as the predominant type of LPS-positive PBMCs. Exogenous RNH1 attenuated LPS-induced CASP5 expression, while increasing IL-1β secretion in PBMCs and THP-1 macrophages. As RNH1 has contradictory effects on inflammation and non-canonical inflammasome activation, its use as a therapeutic agent is limited. However, RNH1 levels may play a central role in iron homeostasis during sepsis, supporting our clinical observations. Hence, RNH1 shows promise as biomarkers for renal and hepatic dysfunction and hepatocyte injury, and may be useful in predicting the outcome of septic patients.

Aging exacerbates oxidative stress and liver fibrosis in an animal model of Down Syndrome.

Down Syndrome (DS) is a common genetic disorder characterized by an extra copy of chromosome 21, leading to dysregulation of various metabolic pathways. Oxidative stress in DS is associated with neurodevelopmental defects, neuronal dysfunction, and a dementia onset resembling Alzheimer's disease. Additionally, chronic oxidative stress contributes to cardiovascular diseases and certain cancers prevalent in DS individuals. This study investigates the impact of ageing on oxidative stress and liver fibrosis using a DS murine model (Ts2Cje mice). Our results show that DS mice show increased liver oxidative stress and impaired antioxidant defenses, as evidenced by reduced glutathione levels and increased lipid peroxidation. Therefore, DS liver exhibits an altered inflammatory response and mitochondrial fitness as we showed by assaying the expression of HMOX1, CLPP, and the heat shock proteins Hsp90 and Hsp60. DS liver also displays dysregulated lipid metabolism, indicated by altered expression of PPARα, PPARγ, FATP5, and CTP2. Consistently, these changes might contribute to non-alcoholic fatty liver disease development, a condition characterized by liver fat accumulation. Consistently, histological analysis of DS liver reveals increased fibrosis and steatosis, as showed by Col1a1 increased expression, indicative of potential progression to liver cirrhosis. Therefore, our findings suggest an increased risk of liver pathologies in DS individuals, particularly when combined with the higher prevalence of obesity and metabolic dysfunctions in DS patients. These results shed a light on the liver's role in DS-associated pathologies and suggest potential therapeutic strategies targeting oxidative stress and lipid metabolism to prevent or mitigate liver-related complications in DS individuals.

Stephaochratidin A, a Rare Stephacidin-Asperochratide Hybrid with Ferroptosis Inhibitory Activity from the Deep-Sea-Derived Aspergillus ochraceus.

One rare stephacidin-asperochratide hybrid, stephaochratidin A (1), was isolated from the deep-sea-derived Aspergillus ochraceus MCCC 3A00521. The relative structure of 1 was determined by comprehensive analyses of its 1D and 2D NMR data as well as HRESIMS data. And the absolute configuration was unambiguously assigned by ECD calculations and the X-ray single-crystal diffraction analysis. Plausible biosynthetic pathway of 1 was proposed. Stephaochratidin A (1) exhibited significant ferroptosis inhibitory activity with the EC50 value of 15.4 μM by downregulating HMOX-1 expression and lipid peroxidation.

Effect of dapagliflozin on ferroptosis through the gut microbiota metabolite TMAO during myocardial ischemia–reperfusion injury in diabetes mellitus rats

Dapagliflozin (DAPA) demonstrates promise in the management of diabetic mellitus (DM) and cardiomyopathy. Trimethylamine N-oxide (TMAO) is synthesized by the gut microbiota through the metabolic conversion of choline and phosphatidylcholine. Ferroptosis may offer novel therapeutic avenues for the management of diabetes and myocardial ischemia–reperfusion injury (IRI). However, the precise mechanism underlying ferroptosis in cardiomyocytes and the specific role of TMAO generated by gut microbiota in the therapeutic approach for DM and myocardial IRI utilizing DAPA need to be further explored. Nine male SD rats with specific pathogen-free (SPF) status were randomly divided equally into the normal group, the DM + IRI (DIR) group, and the DAPA group. The diversity of the gut microbiota was analyzed using 16S rRNA gene sequencing. Additionally, the Wekell technique was employed to measure the levels of TMAO in the three groups. Application of network pharmacology to search for intersection targets of DAPA, DIR, and ferroptosis, and RT-PCR experimental verification. Ultimately, the overlapping targets that were acquired were subjected to molecular docking analysis with TMAO. The changes of Bacteroidetes and Firmicutes in the gut microbiota of DIR rats were most significantly affected by DAPA. Escherichia-Shigella and Prevotella_9 within the phylum Bacteroidetes could be identified as the primary effects of DAPA on DIR. Compared with the normal group, the TMAO content in the DIR group was significantly increased, while the TMAO content in the DAPA group was decreased compared to the DIR group. For the network pharmacology analysis, DAPA and DIR generated 43 intersecting target genes, and then further intersected with ferroptosis-related genes, resulting in 11 overlapping target genes. The mRNA expression of ALB, HMOX1, PPARG, CBS, LCN2, and PPARA decreased in the DIR group through reverse transcription polymerase chain reaction (RT-PCR) validation, while the opposite trend was observed in the DAPA group. The docking score between TMAO and DPP4 was − 5.44, and the MM-GBSA result of − 22.02 kcal/mol. It epitomizes the finest docking performance among all the target genes with the lowest score. DAPA could reduce the levels of metabolite TMAO produced by gut microbiota, thereby regulating related target genes to decrease ferroptosis in DIR cardiomyocytes.

Histone acetyltransferase Kat2a regulates ferroptosis via enhancing Tfrc and Hmox1 expression in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a prevalent myocardial microvascular complication of the myocardium with a complex pathogenesis. Investigating the pathogenesis of DCM can significantly contribute to enhancing its prevention and treatment strategies. Our study revealed an upregulation of lysine acetyltransferase 2 A (Kat2a) expression in DCM, accompanied by a decrease in N6-methyladenosine (m6A) modified Kat2a mRNA levels. Our study revealed an upregulation of lysine acetyltransferase 2 A (Kat2a) expression in DCM, accompanied by a decrease in N6-methyladenosine (m6A) modified Kat2a mRNA levels. Functionally, inhibition of Kat2a effectively ameliorated high glucose-induced cardiomyocyte injury both in vitro and in vivo by suppressing ferroptosis. Mechanistically, Demethylase alkB homolog 5 (Alkbh5) was found to reduce m6A methylation levels on Kat2a mRNA, leading to its upregulation. YTH domain family 2 (Ythdf2) played a crucial role as an m6A reader protein mediating the degradation of Kat2a mRNA. Furthermore, Kat2a promoted ferroptosis by increasing Tfrc and Hmox1 expression via enhancing the enrichment of H3K27ac and H3K9ac on their promoter regions. In conclusion, our findings unveil a novel role for the Kat2a-ferroptosis axis in DCM pathogenesis, providing valuable insights for potential clinical interventions.

A bioinspired regenerative antimicrobial hydrogel coating for cardiovascular implantable electronic devices

Elderly patients predispose to cardiovascular implantable electronic devices (CIEDs) pocket infections due to multiple comorbidities. Treating infections with the antibiotics further carry higher risks for complications, and surgical intervention can be costly when device removal and reimplantation are required, both emphasizing the importance of novel preventive strategies to minimize the incidence of pocket infections. To meet the unique needs for elderly, we constructed an CIED surface modified hydrogel which crosslinked polyethylene glycol diacrylate (PEGDA) with hyaluronic acid-nitrobenzene (HN) to form the polymeric structures that mimic the natural environment for promoting “Pocket” surrounding tissue integration and healing. Importantly, we synthesized the new peptidomimetics FK-13 derived by shortening amino acid sequence of LL-37 which is the only human cathelicidin-derived antimicrobial peptide. By incorporating FK-13 with initial PN hydrogel via Schiff base formation, the created PN-FK hydrogel exhibited broad-spectrum antimicrobial activityagainst bacteria with excellent biocompatibility and mechanical properties in a long-term release manner. In an in vitro setting, PN-FK hydrogel demonstrated the regeneration capacity by expression of Hmox1, Col5 and Col6 associated genes in fibroblasts as well as expression of Gpx1, Cdc20 and MMP9 genes in stem cells to accelerate self-renewal, collagen secretion and reconstitution of matrix components. In the following in vivo model of subcutaneous implantation, CIED-shape titanium mesh with surface modification by PN-FK hydrogel efficiently subsided over-inflammation compared to bare titanium implant, and expedited collagen deposition and angiogenesis in peri-pocket tissues within 2 weeks. These findings underscore the potential of the PN-FK hydrogel as a transformative approach to CIED postoperative management, offering a dual-action solution that combines infection resistance with tissue regeneration capabilities.