MicroRNA mediated suppression of airway lactoperoxidase by TGF-ß1 and cigarette smoke promotes airway inflammation.

Transforming Growth Factor Beta1 (TGF-ß1) signaling is upregulated in Chronic Obstructive Pulmonary disease (COPD), smokers, and people living with HIV. Cigarette smoking and HIV are also independent risk factors for COPD. Chronic inflammation is a hallmark of COPD. However, the underlying mechanisms remain unknown. Previous research has suggested that TGF-ß1 alters the airway epithelial microRNAome and transcriptome, potentially contributing to lung inflammation. The Lactoperoxidase (LPO) system is an integral component of innate immunity within the airway. LPO plays a crucial role in host defense by catalyzing the oxidation of thiocyanate to hypothiocyanite in the presence of hydrogen peroxide (H2O2), generating a potent antibacterial and antiviral agent. Additionally, the LPO system potentially aids in maintaining cellular redox balance by reducing the levels of H2O2, thus mitigating oxidative stress within the airway epithelium. LPO dysfunction can impair immune responses and exacerbate inflammatory processes in respiratory diseases.In this study, primary bronchial epithelial cells and bronchial cell lines were treated with TGF-ß1 and exposed to cigarette smoke to characterize the effect of these factors on LPO and their downstream effects. RT-qPCR and Western Blot were applied to quantify mRNA and proteins' expression. The levels of H2O2 were detected using the Amplex Red Assay. Magnetofection and transfection were applied to probe the effect of miR-449b-5p. Staining procedures using the MitoTracker Green and C12FDG dyes were used to establish mitochondria mass and senescence. The levels of pro-inflammatory cytokines were measured via Luminex assays.We found that TGF-ß1 and cigarette smoke suppressed airway LPO expression, increasing H2O2 levels. This increase in H2O2 had downstream effects on mitochondrial homeostasis, epithelial cellular senescence, and the pro-inflammatory cytokine response. We demonstrate for the first time that airway LPO is regulated by TGF-ß1-induced miRNA-mediated post-transcriptional silencing through miR-449b-5p in the lungs. Further, we identify and validate miR-449-5p as the candidate miRNA upregulated by TGF-ß1, which is involved in LPO suppression. This paper demonstrates a new mechanism by which TGF-ß1 can lead to altered redox status in the airway.

Lactoperoxidase catalytically oxidize hydrogen sulfide via intermediate formation of sulfheme derivatives.

The biological chemistry of hydrogen sulfide (H2S) with physiologically important heme proteins is in the focus of redox biology research. In this study, we investigated the interactions of lactoperoxidase (LPO) with H2S in the presence and absence of molecular dioxygen (O2) or hydrogen peroxide (H2O2). Under anaerobic conditions, native LPO forms no heme-H2S complex upon sulfide exposure. However, under aerobic conditions or in the presence of H2O2 the formation of both ferrous and ferric sulfheme (sulfLPO) derivatives was observed based on the appearances of their characteristic optical absorptions at 638 nm and 727 nm, respectively. Interestingly, we demonstrate that LPO can catalytically oxidize H2S by H2O2 via intermediate formation of relatively short-lived ferrous and ferric sulfLPO derivatives. Pilot product analyses suggested that the turnover process generates oxidized sulfide species, which include sulfate S O 4 2 - and inorganic polysulfides ( H S x - ; x = 2-5). These results indicated that H2S can serve as a non-classical LPO substrate by inducing a reversible sulfheme-like modification of the heme porphyrin ring during turnover. Furthermore, electron paramagnetic resonance data suggest that H2S can act as a scavenger of H2O2 in the presence of LPO without detectable formation of any carbon-centered protein radical species, suggesting that H2S might be capable of protecting the enzyme from radical-mediated damage. We propose possible mechanisms, which explain our results as well as contrasting observations with other heme proteins, where either no sulfheme formation was observed or the generation of sulfheme derivatives provided a dead end for enzyme functions.

The BLV-miRNAs pathway of BLV inhibits the expression of Lactoferrin, Lactoperoxidase, Alpha-lactalbumin and Beta-lactoglobulin proteins.

Bovine leukemia virus (BLV) is a widespread virus that decreases milk production and quality in dairy cows. As crucial components of BLV, BLV-encoded microRNAs (BLV-miRNAs) affect BLV replication and may impact the synthesis of Lactoferrin (LTF), Lactoperoxidase (LPO), Alpha-lactalbumin (alpha-LA), and Beta-lactoglobulin (beta-LG). In this study, we investigated the targeting relationship between BLV-miRNAs and LTF, LPO, alpha-LA, and beta-LG in cow's milk. Additionally, we investigated the possible mechanisms by which BLV reduces milk quality. The results showed that cow's milk had significantly lower levels of LTF, LPO, and alpha-LA proteins in BLV-positive cows than in BLV-negative cows. BLV-△miRNAs (miRNA-deleted BLV) enhanced the reduction of LPO, alpha-LA, and beta-LG protein levels caused by BLV infection. Multiple BLV-miRNAs have binding sites with LTF and LPO mRNA; however, only BLV-miR-B1-5 P has a targeting relationship with LPO mRNA. The results revealed that BLV-miR-B1-5 P inhibits LPO protein expression by targeting LPO mRNA. However, BLV does not directly regulate the expression of LTF, alpha-LA, or beta-LG proteins through BLV-miRNAs.

The molecular mechanism of ferroptosis and its relationship with Parkinson's disease.

Neurodegenerative diseases such as Parkinson's disease (PD) have complex pathogenetic mechanisms. Genetic, age, and environmental factors are all related to PD. Due to the unclear pathogenesis of PD and the lack of effective cure methods, it is urgent to find new targets for treating PD patients. Ferroptosis is a form of cell death that is reliant on iron and exhibits distinct morphological and mechanistic characteristics compared to other types of cell death. It encompasses a range of biological processes, including iron/lipid metabolism and oxidative stress. In recent years, research has found that ferroptosis plays a crucial role in the pathophysiological processes of neurodegenerative diseases and stroke. Therefore, ferroptosis is also closely related to PD, This article reviews the core mechanisms of ferroptosis and elucidates the correlation between PD and ferroptosis. In addition, new compounds that have emerged in recent years to exert anti PD effects by inhibiting the ferroptosis signaling pathway were summarized. I hope to further elaborate the relationship between ferroptosis and PD through the review of this article, and provide new strategies for developing PD treatments targeting ferroptosis.

Development of a Normal Porcine Cell Line Growing in a Heme-Supplemented, Serum-Free Condition for Cultured Meat.

A key element for the cost-effective development of cultured meat is a cell line culturable in serum-free conditions to reduce production costs. Heme supplementation in cultured meat mimics the original meat flavor and color. This study introduced a bacterial extract generated from Corynebacterium that was selected for high-heme expression by directed evolution. A normal porcine cell line, PK15, was used to apply the bacterial heme extract as a supplement. Consistent with prior research, we observed the cytotoxicity of PK15 to the heme extract at 10 mM or higher. However, after long-term exposure, PK15 adapted to tolerate up to 40 mM of heme. An RNA-seq analysis of these heme-adapted PK15 cells (PK15H) revealed a set of altered genes, mainly involved in cell proliferation, metabolism, and inflammation. We found that cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1), lactoperoxidase (LPO), and glutathione peroxidase 5 (GPX5) were upregulated in the PK15H heme dose dependently. When we reduced serum serially from 2% to serum free, we derived the PK15H subpopulation that was transiently maintained with 5-10 mM heme extract. Altogether, our study reports a porcine cell culturable in high-heme media that can be maintained in serum-free conditions and proposes a marker gene that plays a critical role in this adaptation process.

Anti oxidative/neuro-inflammation properties of Withania somnifera root extract on rotenone induced stress in rat brain.

Parkinson's disease (PD) is a neurological condition that worsens with age (i.e., 1% of people over 65) with no permanent cure. Hence, finding a disease-modifying agent with fewer undesirable side effects is urgently needed. Parkinson's disease (PD) pathology results in the degeneration of dopaminergic (DAergic) neurons by accumulating lewy bodies, alpha-synuclein (-syn), lowering anti-oxidants, increasing neuronal inflammation, and altering neuron shape. A well-researched natural substance called Withania somnifera (WS) has a potent anti-oxidative, anti-inflammatory, and anti-neurodegenerative impact. WS, sometimes called as Indian Ginseng, is a subtropical undershrub of the Solanaceae family together with Ashwagandha. In the current work, EWSR's anti-inflammatory and neuroprotective efficacy was assessed in relation to rotenone-induced oxidative stress (i.e., LPO, CAT, and SOD and GSH), microglial activation, and neurodegeneration in the rotenone rat PD model. In ROT-induced brains, EWSR therapy resulted in a considerable decrease in LPO and increased levels of the antioxidants SOD, CAT, and GSH. Furthermore, our research showed that the intraperitoneal treatment of EWSR (40 mg/kg) in rotenone-induced rats reduced microglial activation and neuron loss in the substantia nigra (SN) and hippocampus caused by rotenone-induced neurotoxicity. Based on the observations, EWSR can be considered as an excellent source for neuroprotection, due to its significant anti-oxidative, anti-inflammatory, anti-neurodegenerative and anti-microglial properties when administered individually and in combination with known anti-inflammatory compounds (Doxycycline and Ellagic acids). But, further research is required before replacing the known neuroprotective treatments with phytochemical treatments.

Basic mechanisms and novel potential therapeutic targets for ferroptosis in acute myeloid leukemia.

Ferroptosis is a form of cell death that is regulated by iron and characterized by the buildup of lipid peroxides (LPO) and subsequent rupture of the cell membrane. The molecular mechanisms of ferroptosis involve metabolic pathways related to iron, lipids, and amino acids, which contribute to the production of lipid reactive oxygen species (ROS). In recent years, there has been increasing attention on the occurrence of ferroptosis in various diseases. Ferroptosis has been found to play a crucial role in cardiovascular diseases, digestive diseases, respiratory and immunological diseases, and particularly in malignancies. However, there is still a lack of studies on ferroptosis in acute myeloid leukemia (AML). This paper provides a comprehensive review of the mechanism of ferroptosis and its regulatory molecules and therapeutic agents in AML. It also evaluates the relationship between ferroptosis-related genes (FRGs), non-coding RNAs (ncRNAs), and prognosis to develop prognostic molecular models in AML. The study also explores the association between ferroptosis and immune infiltration in AML, to identify novel potential target regimens for AML.

Features of the Free Radical Oxidation Process and Antioxidant System in Newborns Born to HIV-Infected of Mothers Who Received Antiretroviral Therapies to Prevent HIV Transmission.

The LPO processes and the state of the antioxidant system in perinatally HIV-exposed newborns were studied. Perinatally HIV-exposed (n=62) and healthy newborns (n=80; control) were examined retrospectively (Apgar score 8 in both groups). Blood plasma and erythrocyte hemolysate were used as the material for biochemical tests. Using spectrophotometric, fluorometric, and statistical methods, we found enhanced LPO processes insufficiently compensated by the antioxidant system with excessive accumulation of damaging metabolites in the blood of perinatally HIV-exposed newborns. These changes can be a consequence of oxidative stress during the perinatal period.

Ethoxidol as a Broad-spectrum Adaptogen.

BACKGROUND: Stress factors lead to a shift in the antioxidant-prooxidant relationship, allowing an increase in the generation of reactive oxygen species (ROS) by mitochondria, which results in the development of oxidative stress. Consequently, it is possible to put forward an assumption that drugs which reduce the excessive generation of ROS by these organelles should increase the body's resistance to stress factors. Antioxidants can be used as such drugs. In this regard, the aim of this work was to study the bioenergetics characteristic of mitochondria under stress conditions and under the action of 2-ethyl-6-methyl-3-hydroxypyridinium hydroxybutanedioate (ethoxidol). METHODS: The antiradical activity of the drug was evaluated by the chemiluminescent method (CL). The functional state of the mitochondria was studied with reference to the level of lipid peroxidation by the spectrofluorimetry and in terms of fatty acid composition of mitochondrial membranes using the chromatography technique. The study of mitochondrial morphology was performed employing the method of atomic force microscopy. RESULTS: The injection in mice of ethoxidol at a dose of 10-5 mol/kg for 7 days led to the prevention of the stress-induced increase in the intensity of LPO in the membranes of the mitochondria, and swelling of these organelles; it also prevented a decrease in the content of unsaturated fatty acids, containing 18 and 20 carbon atoms. At the same time, ethoxidol increased the life expectancy of mice by 3.0-4.2 times in conditions of various types of hypoxia. CONCLUSION: The adaptogenic properties of ethoxidol can be attributed to its antiradical and antioxidant properties.

Evaluation of the antioxidative potential of diisopropyldithiocarbamates sodium salt on diclofenac-induced toxicity in male albino rats.

Diclofenac (DIC) is a non-steroidal anti-inflammatory drug (NSAID) which is known to induce oxidative stress. Dithiocarbamates are compounds with proven antioxidant effect. The aim of the present study was to investigate the antioxidant capacity of diisopropyldithiocarbamates sodium salt (a synthetized compound) (Na(i-Pr2dtc)) against diclofenac-induced toxicity in the testes of male Wistar albino rats. The animals were assigned into six groups of six rats each. Group 1 (control) received corn oil, Groups 2, 3, 4, 5, 6 received DIC (100 mg/kg), DIC and (Na(i-Pr2dtc) (30 mg/kg), DIC and vitamin E (30 mg/kg), (Na(i-Pr2dtc) (30 mg/kg) and vitamin E only respectively. Our findings show that treatment with DIC significantly reduced superoxide dismutase (SOD) activity by 42% compared to normal control (NC) animals. In DIC treated group, Na(i-Pr2dtc) caused a 17% elevation of catalase (CAT) activity compared to DIC only group. Reduced glutathione level was significantly reduced in DIC only treated group when compared with DIC and VIT E treated group. Photomicrographs of testis from Na(i-Pr2dtc) treated rats showed normal seminiferous epithelium with no lesions. In conclusion, Na(i-Pr2dtc) has antioxidant properties.

Modulatory Efficiency of LP/LF Nano-Combination on Neurochemical and Behavioural Retardations in the Brain of Induced-Epileptic Rats.

<b>Background and Objective:</b> Epilepsy is one of the normal neurological problems that came about because of strange electrical movements and prompt serious and far-reaching cell misfortune in the mind. This study aimed to investigate if a nano-Chitosan formulation loaded with bovine milk lactoperoxidase (LPO) and lactoferrin (LF) could prevent Lithium Chloride/Pilocarpine-induced epilepsy in rats or not. <b>Materials and Methods:</b> Adult male rats (200-250 g) were partitioned into four groups (8 animals each) as follows: Group (1) Normal rats served as control group and received saline orally, group (2) Normal rats ingested with a daily oral dose of LPO and LF-NPS formulation at 50 mg kg¹, group (3) Pilocarpine-induced epileptic rats and group (4) Epilepsy-modeled rats were treated with LPO+LF NPs (50 mg/kg/day, orally) for 6 weeks. <b>Results:</b> The results revealed that the administration of LPO+LF-NPs markedly improved the induced-epilepsy disorders, this was monitored from the significant reduction in the values of caspase-3, TNF-α, IL-1ß, CD4⁺, MDA and NO coupled with remarkable raise in AchE-ase, dopamine, serotonin, SOD and GPx, CAT and GSH values in both brain regions. <b>Conclusion:</b> This study supported the anti-epilepsy features of LPO+LF-NPS against Lithium Chloride/Pilocarpine-induced epilepsy in rats through the improvement of the immune response, reduction of inflammation and restoration of the impaired oxidative stress status.

The levels of oxidative stress in a combination of stress factors.

We studied the effect of the combined action of ionizing radiation and induced immobilization stress on the lipid peroxidation process and antioxidant protection of organs (mesenteric lymph nodes, spleen, adrenal glands, thymus, and liver) and immune cels - the blood lymphocytes. Results were obtained on the role of free-radical oxidation in combination with exposure to ionizing radiation and immobilization stress at an early stage in the experiment. Gamma radiation in the acute period resulted in significant changes in lipoperoxidation and antioxidant systems. The first period of immobilization stress was marked by the imbalance of LPO-AOS systems disturbance with an accumulation of toxic compounds in tissues which had affected their function. The combined sublethal gamma radiation and immobilization stress disturbed the functional activity of adaptive systems of the body in the early stage of adaptation syndrome. Furthermore, the results show the dominant role of ionizing radiation in it.

Origanum majorana essential oil improves the rat's sexual behavior and testicular oxidative damage induced by imidacloprid via modulating the steroidogenesis pathways.

The neonicotinoid insecticide imidacloprid has been linked to significant reproductive damage in mammals. Origanum majorana essential oil (OME) is a natural herbal product used in the management of many diseases due to its strong antioxidant effects. The oil was hydrodistilled from O. Majorana and analyzed using GC/MS then its possible protective mechanisms against IMI-induced reprotoxicity in male rats were investigated. 28-adult male Wistar rats were divided into 4 groups as follows: group (1) control group, group (2) OME, group (3) IMI, and group (4) IMI + OME. The treatments were applied daily via oral gavage for 60 days. Remarkable abnormalities in both territorial aggressive and sexual behaviors were observed in IMI-treated rats with a significant elevation of serum FSH and LH as well as altered testicular redox status. Along with inhibition of the testicular expression of StAR and aromatase genes and serum total testosterone in addition to abnormal sperm count, viability, motility, and morphology. Histopathological examination showed severe degeneration and necrosis in both germ cells and Leydig cells with atrophy in most of the seminiferous tubules. Co-administration of OME with IMI notably improved all the above-mentioned studied parameters, and restored rats' spermatogenesis, sexual behavior, and favorably modulates the levels of both testosterone and gonadotropic hormones via its potent antioxidant effect. These findings support the use of OME as a fertility enhancer and suggest that it could be used to manage pesticide-induced male infertility.

Therapeutic efficacy of Nano-formulation of lactoperoxidase and lactoferrin via promoting immunomodulatory and apoptotic effects.

This study identifies promising potential of a novel and safer nanocombination of bovine milk lactoperoxidase (LPO) and lactoferrin (LF) to target breast cancer in vitro and in adult female albino rat model. Favorable selective anticancer effects of the prepared nanocombination were observed, in a dose-dependent manner, against both MCF-7 and MDA cell lines, sparing normal HFB-4 cells. The administration of LPO + LFNPs markedly improved the induced-breast cancer disorders, prolonged survival and reduced the values of serum TNF-α, IL1ß, CD4+, ALAT, ASAT, urea, creatinine, cholesterol and triglycerides with remarkable elevation in mammary SOD and GPx activity and GSH level. Moreover, the histopathological findings showed that LPO + LFNPs succeeded in prevention of mammary gland tumorigenesis. Superior efficacy of LPO + LFNPs was observed against pro-inflammatory cytokines through their anti-inflammatory and immunomodulatory properties. The treatment of LPO + LFNPs more significantly modulated the apoptosis and enhanced the expression of cell cycle regulator genes, which demonstrates a successful tumor therapy in vitro and in vivo. Therefore, this study provided evidence that the chemo-preventive feature of LPO + LFNPs may offer a novel alternative therapy for the treatment of breast cancer through enhances apoptosis pathway, improvement of immune response, reduction of inflammation and restoration of the impaired oxidative stress.

Synergistic hydroxyl radical formation, system XC- inhibition and heat shock protein crosslinking tango in ferrotherapy: A prove-of-concept study of "sword and shield" theory.

Ferroptosis provide new insights into designing nanomedicines for enhanced cancer therapy; however, its antitumor efficacy is relatively low, mainly due to self-protective mechanism of cancer cells, e.g., heat shock protein (HSP) overexpression. Since HSPs can be modified/inhibited by lipid peroxidation (LPO) ending products, we construct a nanoplatform, namely MPDA@Fe3O4-Era, to amplify intracellular reactive oxygen species (ROS) and LPO for synergistic ferrotherapy. Upon tumor acidic microenvironment and local near-infrared stimuli, this nanoplatform releases Fe3O4 and reacts with intracellular hydrogen peroxide (H2O2) to promote Fenton reaction, and yields significant intracellular ROS (specifically hydroxyl radical, •OH) and LPO. In turn, LPO ending products crosslink HSPs to destroy self-preservation pathways of cancer cells to enhance anticancer effect. Meanwhile, the released erastin inhibits system XC - signal pathway to depletes glutathione. Fe3O4 loading further provides magnetic resonance imaging T2-weighted signal to guide anti-tumor treatment. Together, this nanoplatform not only provides •OH (as a "sword" to attack tumor cells), but also inhibits system XC - signal pathway and crosslinks HSP (break down the "shield" of tumor cells) to maximize synergistic ferro-therapeutic effect. MPDA@Fe3O4-Era plus laser irradiation possessed highly efficient tumor suppression with magnified the levels of •OH and inactive glutathione peroxidase 4 (GPX4), which can promote the development of precise cooperative cancer therapy.

Vitamin D-Dimer: A Possible Biomolecule Modulator in Cytotoxic and Phagocytosis Processes?

Background: Vitamin D3 complexed to deglycosylated vitamin D binding protein (VitD-dgVDBP) is a water-soluble vitamin D dimeric compound (VitD-dgVDBP). It is not clear how VitD-dgVDBP affects circulating monocytes, macrophages, other immune cell systems, including phagocytosis and apoptosis, and the generation of reactive oxygen species (ROS) compared to dgVDBP. Methods: Flow cytometry was used to measure superoxide anion radical (O2*−) levels and macrophage activity in the presence of VitD-dgVDBP or dgVDBP. VitD-dgVDBP was incubated with normal human lymphocytes (nPBMCs), and several clusters of determination (CDs) were estimated. dgVDBP and VitD-dgVDBP apoptosis was estimated on malignant prostatic cells. Results: The macrophage activity was 2.8-fold higher using VitD-dgVDBP (19.8·106 counts) compared to dgVDBP (7.0·106 counts), but O2*− production was 1.8-fold lower in favor of VitD-dgVDBP (355·103 counts) compared to dgVDBP (630·106 counts). The calculated ratio of the radical/macrophage activity was 5-fold lower compared to that of dgVDBP. Only VitD-dgVDBP activated caspase-3 (8%), caspase-9 (13%), and cytochrome-C (11%) on prostatic cancer cells. PE-Cy7-labeled VitD-dgVDBP was found to bind to cytotoxic suppressor cells, monocytes/macrophages, dendritic and natural killer cells (CD8+), and helper cells (CD4+). After 12 h of co-incubation of nPBMCs with VitD-dgVDBP, significant activation and expression were measured for CD16++/CD16 (0.6 ± 0.1% vs. 0.4 ± 0.1%, p < 0.05), CD45k+ (96.0 ± 6.0% vs. 84.7 ± 9.5%, p < 0.05), CD85k+ (24.3 ± 13.2% vs. 3.8 ± 3.2%, p < 0.05), and CD85k+/CD123+ (46.8 ± 8.1% vs. 3.5 ± 3.7%, p < 0.001) compared to the control experiment. No significant difference was found using CD3+, CD4+, CD8+, CD4/CD8, CD4/CD8, CD16+, CD16++, CD14+, or CD123+. A significant decline in CD14+/CD16+ was obtained in the presence of VitD-dgVDBP (0.7 ± 0.2% vs. 3.1 ± 1.7%; p < 0.01). Conclusion: The newly developed water-soluble VitD3 form VitD-dgVDBP affected cytotoxic suppressor cells by activating the low radical-dependent CD16 pathway and seemed to induce apoptosis in malignant prostatic cells.

Sanguinarine Induces H2O2-Dependent Apoptosis and Ferroptosis in Human Cervical Cancer.

Sanguinarine (SNG) is a benzophenanthridine alkaloid isolated mainly from Sanguinaria canadensis, Chelidonium majus, and Macleaya cordata. SNG is considered an antineoplastic agent based on its cytotoxic activity against various tumors. However, the exact molecular mechanism through which SNG mediates this activity has not been elucidated. Here, we report that SNG induces death in human cervical cancer (HeLa) cells through activation of two interdependent cell death pathways-apoptosis and ferroptosis. SNG-induced apoptosis was characterized by caspase activation and PARP cleavage, while ferroptosis involved solute carrier family 7 member 11 (SLC7A11) down-regulation, glutathione (GSH) depletion, iron accumulation, and lipid peroxidation (LPO). Interestingly, incubation with caspase inhibitor z-VAD-fmk not only inhibited the features of apoptosis, but also negated markers of SNG-induced ferroptosis. Similarly, pretreatment with ferroptosis inhibitor ferrostatin-1 (Fer-1), apart from rescuing cells from SNG-induced ferroptosis, also curbed the features of SNG-induced apoptosis. Our study implies that, together, apoptosis and ferroptosis act as partners in the context of SNG mediated tumor suppression in HeLa cells. Importantly, SNG increased the generation of reactive oxygen species (ROS), and ROS inhibition blocks the induction of both apoptosis and ferroptosis. These findings highlight the value of continued investigation into the potential use of SNG as an antineoplastic agent.

Canonical Wnt signaling works downstream of iron overload to prevent ferroptosis from damaging osteoblast differentiation.

Excessive iron has emerged in a large population of patients suffering from degenerative or hematological diseases with a common outcome, osteoporosis. However, its underlying mechanism remains to be clarified in order to formulate effective prevention and intervention against the loss of bone-forming osteoblasts. We show herein that increased intracellular iron by ferric ammonium citrate (FAC) mimicking the so-called non-transferrin bound iron concentrations leads to ferroptosis and impaired osteoblast differentiation. FAC upregulates the expression of Trfr and DMT1 genes to increase iron uptake, accumulating intracellular labile ferrous iron for iron overload status. Then, the excessive ferrous iron generates reactive oxygen species (ROS) and lipid peroxidation products (LPO), causing ferroptosis with its typical mitochondrial morphological changes, such as shrinkaged and condensed membrane with diminution and loss of crista and outer membrane rupture. We further examined that ferroptosis is the main cause responsible for FAC-disrupted osteoblast differentiation, although apoptosis and senescence are concurrently induced as well. Mechanistically, we revealed that iron dose-dependently down-regulates the expression of Wnt target genes and inhibits the transcription of Wnt reporter TopFlash construct, so as to inhibit the canonical Wnt signaling. Wnt agonist, ferroptosis inhibitor, or antioxidant melatonin reverses iron-inhibited canonical Wnt signaling to restore osteoblast differentiation by reducing ROS and LPO production to prevent ferroptosis notably without reducing iron overload. This study proposes a working model against excessive iron-induced osteoporosis: iron chelator deferoxamine or the above three drugs prevent ferroptosis, restore traditional Wnt signaling to maintain osteoblast differentiation no matter whether iron overload is removed or not. Additionally, iron chelator should be used to a suitable extent because iron itself is necessary for osteogenic differentiation.

Celastrol induces ferroptosis in activated HSCs to ameliorate hepatic fibrosis via targeting peroxiredoxins and HO-1.

Ferroptosis is a form of regulated cell death, characterized by excessive membrane lipid peroxidation in an iron- and ROS-dependent manner. Celastrol, a natural bioactive triterpenoid extracted from Tripterygium wilfordii, shows effective anti-fibrotic and anti-inflammatory activities in multiple hepatic diseases. However, the exact molecular mechanisms of action and the direct protein targets of celastrol in the treatment of liver fibrosis remain largely elusive. Here, we discover that celastrol exerts anti-fibrotic effects via promoting the production of reactive oxygen species (ROS) and inducing ferroptosis in activated hepatic stellate cells (HSCs). By using activity-based protein profiling (ABPP) in combination with bio-orthogonal click chemistry reaction and cellular thermal shift assay (CETSA), we show that celastrol directly binds to peroxiredoxins (PRDXs), including PRDX1, PRDX2, PRDX4 and PRDX6, through the active cysteine sites, and inhibits their anti-oxidant activities. Celastrol also targets to heme oxygenase 1 (HO-1) and upregulates its expression in activated-HSCs. Knockdown of PRDX1, PRDX2, PRDX4, PRDX6 or HO-1 in HSCs, to varying extent, elevated cellular ROS levels and induced ferroptosis. Taken together, our findings reveal the direct protein targets and molecular mechanisms via which celastrol ameliorates hepatic fibrosis, thus supporting the further development of celastrol as a promising therapeutic agent for liver fibrosis.

The Tol-Pal System Plays an Important Role in Maintaining Cell Integrity During Elongation in Escherichia coli.

The Tol-Pal system is a transenvelope complex widely conserved among Gram-negative bacteria. It is recruited to the septal ring during cytokinesis, and its inactivation causes pleiotropic phenotypes mainly associated with the division process. From our genetic screen to identify factors required for delaying lysis upon treatment of beta lactams, we discovered that the tol-pal mutant shares similar defects with mutants of the major class A PBP system (PBP1b-LpoB) in terms of lysis prevention. Further phenotypic analyses revealed that the Tol-Pal system plays an important role in maintaining cell integrity not only during septation, but also during cell elongation. Simultaneous inactivation of the Tol-Pal system and the PBP1b-LpoB system leads to lysis during cell elongation as well as during division. Moreover, production of the Lpo activator-bypass PBP1b, but not wild-type PBP1b, partially suppressed the Tol-Pal defect in maintaining cell integrity upon treatment of mecillinam specific for the Rod system, suggesting that the Tol-Pal system is likely to be involved in the activation of aPBP by Lpo factors. Overall, our results indicate that the Tol-Pal system plays an important role in maintaining cell wall integrity during elongation in addition to its multifaceted roles during cytokinesis.