Fish Oil Ameliorates Vibrio parahaemolyticus Infection in Mice by Restoring Colonic Microbiota, Metabolic Profiles, and Immune Homeostasis.

The effect of fish oil (FO) on colonic function, immunity, and microbiota was investigated in Vibrio parahaemolyticus (Vp)-infected C57BL/6J mice. Mice intragastrically presupplemented with FO (4.0 mg) significantly reduced Vp infection as evidenced by stabilizing body weight and reducing disease activity index score and immune organ ratios. FO minimized colonic pathological damage, strengthened the mucosal barrier, and sustained epithelial permeability by increasing epithelial crypt depth, goblet cell numbers, and tight junctions and inhibiting colonic collagen accumulation and fibrosis protein expression. Mechanistically, FO enhanced immunity by decreasing colonic CD3+ T cells, increasing CD4+ T cells, downregulating the TLR4 pathway, reducing interleukin-17 (IL-17) and tumor necrosis factor-α, and increasing immune cytokine IL-4 and interferon-γ levels. Additionally, FO maintained colonic microbiota eubiosis by improving microbial diversity and boosting Clostridium, Akkermansia, and Roseburia growth and their derived propionic acid and butyric acid levels. Collectively, FO alleviated Vp infection by enriching beneficial colonic microbiota and metabolites and restoring immune homeostasis.

The effect of sulindac on redox homeostasis and apoptosis-related proteins in melanotic and amelanotic cells.

BACKGROUND: Non-steroidal anti-inflammatory drugs have been shown to inhibit the development of induced neoplasms. Our previous research demonstrated that the cytotoxicity of sulindac against melanoma cells is comparable to dacarbazine, the drug used in chemotherapy. The aim of this study was to investigate the mechanism of sulindac cytotoxicity on COLO 829 and C32 cell lines. METHODS: The influence of sundilac on the activity of selected enzymes of the antioxidant system (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)) and the content of hydrogen peroxide as well as the level of proteins initiating (p53, Bax) and inhibiting (Bcl-2) apoptosis were measured in melanoma cells. RESULTS: In melanotic melanoma cells, sulindac increased the activity of SOD and the content of H2O2 but decreased the activity of CAT and GPx. The level of p53 and Bax proteins rose but the content of Bcl-2 protein was lowered. Similar results were observed for dacarbazine. In amelanotic melanoma cells, sulindac did not cause an increase in the activity of measured enzymes or any significant changes in the level of apoptotic proteins. CONCLUSION: The cytotoxic effect of sulindac in the COLO 829 cell line is connected to disturbed redox homeostasis by changing the activity of SOD, CAT, GPx, and level of H2O2. Sulindac also induces apoptosis by changing the ratio of the pro-apoptotic/anti-apoptotic protein. The presented studies indicate the possibility of developing target therapy against melanotic melanoma using sulindac.

Cannabidiol mediates epidermal terminal differentiation and redox homeostasis through aryl hydrocarbon receptor (AhR)-dependent signaling.

BACKGROUND: Cannabidiol, a non-psychoactive phytocannabinoid, has antioxidant and anti-inflammatory activity in keratinocytes. However, the signaling pathway through which cannabidiol exerts its effect on keratinocytes or whether it can modulate keratinocyte differentiation has not been fully elucidated yet. OBJECTIVE: We investigated whether cannabidiol modulates epidermal differentiation and scavenges reactive oxygen species through the aryl hydrocarbon receptor (AhR) in keratinocytes and epidermal equivalents. METHODS: We investigated the cannabidiol-induced activation of AhR using AhR luciferase reporter assay, qRT-PCR, western blot, and immunofluorescence assays. We also analyzed whether keratinocyte differentiation and antioxidant activity are regulated by cannabidiol-induced AhR activation. RESULTS: In both keratinocytes and epidermal equivalents, cannabidiol increased both the mRNA and protein expression of filaggrin, involucrin, NRF2, and NQO1 and the mRNA expression of the AhR target genes, including CYP1A1 and aryl hydrocarbon receptor repressor. Additionally, cannabidiol showed antioxidant activity that was attenuated by AhR knockdown or co-administration with an AhR antagonist. Moreover, cannabidiol increased the ratio of OVOL1/OVOL2 mRNA expression, which is a downstream regulator of AhR that mediates epidermal differentiation. In addition to increased expression of barrier-related proteins, cannabidiol-treated epidermal equivalent showed a more prominent granular layer than the control epidermis. The increased granular layer by cannabidiol was suppressed by the AhR antagonist. CONCLUSION: Cannabidiol can be a modulator of the AhR-OVOL1-filaggrin axis and AhR-NRF2-NQO1 signaling, thus indicating a potential use of cannabidiol in skin barrier enhancement and reducing oxidative stress.

RNA methylation and cellular response to oxidative stress-promoting anticancer agents.

Disruption of the complex network that regulates redox homeostasis often underlies resistant phenotypes, which hinder effective and long-lasting cancer eradication. In addition, the RNA methylome-dependent control of gene expression also critically affects traits of cellular resistance to anti-cancer agents. However, few investigations aimed at establishing whether the epitranscriptome-directed adaptations underlying acquired and/or innate resistance traits in cancer could be implemented through the involvement of redox-dependent or -responsive signaling pathways. This is unexpected mainly because: i) the effectiveness of many anti-cancer approaches relies on their capacity to promote oxidative stress (OS); ii) altered redox milieu and reprogramming of mitochondrial function have been acknowledged as critical mediators of the RNA methylome-mediated response to OS. Here we summarize the current state of understanding on this topic, as well as we offer new perspectives that might lead to original approaches and strategies to delay or prevent the problem of refractory cancer and tumor recurrence.

Emerging polyfluorinated compound Nafion by-product 2 disturbs intestinal homeostasis in zebrafish (Danio rerio).

Nafion by-product 2 (Nafion BP2), an emerging fluorinated sulfonic acid commonly used in polymer electrolyte membrane technologies, has been detected in various environmental and human matrices. To date, however, few studies have explored its toxicity. In this study, zebrafish embryos were exposed to Nafion BP2 at concentrations of 20, 40, 60, 80, 100, 120, 140, and 160 mg/L from fertilization to 120 post-fertilization (hpf), and multiple developmental parameters (survival rate, hatching rate, and malformation rate) were then determined. Results showed that Nafion BP2 exposure led to a significant decrease in survival and hatching rates and an increase in malformations. The half maximal effective concentration (EC50) of Nafion BP2 for malformation at 120 hpf was 55 mg/L, which is higher than the globally important contaminant perfluorooctane sulfonate (PFOS, 6 mg/L). Furthermore, exposure to Nafion BP2 resulted in additional types of malformations compared to PFOS exposure. Pathologically, Nafion BP2 caused abnormal early foregut development, with exfoliation of intestinal mucosa, damage to lamina propria, and aberrant proliferation of lamina propria cells. Nitric oxide content also decreased markedly. In addition, embryos showed an inflammatory response following Nafion BP2 exposure, with significantly increased levels of pro-inflammatory factors C4 and IL-6. Acidic mucin in the hindgut increased more than two-fold. 16 S rRNA sequencing revealed a marked increase in the pathogen Pseudomonas otitidis. Furthermore, pathways involved in intestinal protein digestion and absorption, inflammatory response, and immune response were significantly altered. Our findings suggest that the intestine is a crucial toxicity target of Nafion BP2 in zebrafish, thus highlighting the need to evaluate its health risks.

A single-cell mass cytometry platform to map the effects of preclinical drugs on cartilage homeostasis.

No disease-modifying drug exists for osteoarthritis (OA). Despite success in animal models, candidate drugs continue to fail in clinical trials owing to the unmapped interpatient heterogeneity and disease complexity. We used a single-cell platform based on cytometry by time-of-flight (cyTOF) to precisely outline the effects of candidate drugs on human OA chondrocytes. OA chondrocytes harvested from patients undergoing total knee arthroplasty were treated with 2 drugs, an NF-κB pathway inhibitor, BMS-345541, and a chondroinductive small molecule, kartogenin, that showed preclinical success in animal models for OA. cyTOF conducted with 30 metal isotope-labeled antibodies parsed the effects of the drugs on inflammatory, senescent, and chondroprogenitor cell populations. The NF-κB pathway inhibition decreased the expression of p-NF-κB, HIF2A, and inducible NOS in multiple chondrocyte clusters and significantly depleted 4 p16ink4a-expressing senescent populations, including NOTCH1+STRO1+ chondroprogenitor cells. While kartogenin also affected select p16ink4a-expressing senescent clusters, there was a less discernible effect on chondroprogenitor cell populations. Overall, BMS-345541 elicited a uniform drug response in all patients, while only a few responded to kartogenin. These studies demonstrate that a single-cell cyTOF-based drug screening platform can provide insights into patient response assessment and patient stratification.

Exogenous administration of unacylated ghrelin attenuates hepatic steatosis in high-fat diet-fed rats by modulating glucose homeostasis, lipogenesis, oxidative stress, and endoplasmic reticulum stress.

Low levels of unacylated ghrelin (UAG) and a higher ratio of acylated ghrelin (AG)/UAG in obesity are associated with non-alcoholic fatty liver disease (NAFLD). This study tested the potential protective effect of increased circulatory levels of UAG by exogenous UAG administration on hepatic steatosis in high-fat diet (HFD)-fed rats and investigated some possible mechanisms. Rats were divided (n = 6/group) as low fat diet (LFD), LFD + UAG (200 mg/kg), HFD, HFD + UAG (50, 100, or 200 mg/kg). Treatments were given for 8 weeks. Increasing the dose of UAG increased circulatory levels of UAG and normalized the ratio of AG/UAG at the dose of 200 mg/kg. With no change in insulin levels, and in a dose-dependent manner, treatment with UAG to HFD rats attenuated the gain in food intake, body weights, and liver weights, lowered fasting glucose levels, prevented hepatic cytoplasmic vacuolization, and reduced serum and hepatic levels of cholesterol, triglycerides, and free fatty acids. They also progressively reduced levels of reactive oxygen species, lipid peroxides, tumor necrosis factor-α, and interleukin-6, as well as mRNA levels of Bax and caspase-3 but increased levels of glutathione and superoxide dismutase and mRNA levels of Bcl2. In concomitant, UAG, in a dose-response manner, significantly reduced hepatic mRNA levels of SREBP1, SREBP2, ATF-6, IRE-1, and eIF-2α but increased those of PPARα. In conclusion, reducing the circulatory ratio of AG/UAG ratio by exogenous administration of UAG attenuates HFD-induced hepatic steatosis by suppressing lipogenesis, stimulating FAs oxidation, preventing oxidative stress, inflammation, ER stress, and apoptosis.

The 26RFa (QRFP)/GPR103 neuropeptidergic system in mice relays insulin signalling into the brain to regulate glucose homeostasis.

AIMS/HYPOTHESIS: 26RFa (pyroglutamilated RFamide peptide [QRFP]) is a biologically active peptide that regulates glucose homeostasis by acting as an incretin and by increasing insulin sensitivity at the periphery. 26RFa is also produced by a neuronal population localised in the hypothalamus. In this study we investigated whether 26RFa neurons are involved in the hypothalamic regulation of glucose homeostasis. METHODS: 26Rfa+/+, 26Rfa-/- and insulin-deficient male C57Bl/6J mice were used in this study. Mice received an acute intracerebroventricular (i.c.v.) injection of 26RFa, insulin or the 26RFa receptor (GPR103) antagonist 25e and were subjected to IPGTTs, insulin tolerance tests, acute glucose-stimulated insulin secretion tests and pyruvate tolerance tests (PTTs). Secretion of 26RFa by hypothalamic explants after incubation with glucose, leptin or insulin was assessed. Expression and quantification of the genes encoding 26RFa, agouti-related protein, the insulin receptor and GPR103 were evaluated by quantitative reverse transcription PCR and RNAscope in situ hybridisation. RESULTS: Our data indicate that i.c.v.-injected 26RFa induces a robust antihyperglycaemic effect associated with an increase in insulin production by the pancreatic islets. In addition, we found that insulin strongly stimulates 26Rfa expression and secretion by the hypothalamus. RNAscope experiments revealed that neurons expressing 26Rfa are mainly localised in the lateral hypothalamic area, that they co-express the gene encoding the insulin receptor and that insulin induces the expression of 26Rfa in these neurons. Concurrently, the central antihyperglycaemic effect of insulin is abolished in the presence of a GPR103 antagonist and in 26RFa-deficient mice. Finally, our data indicate that the hypothalamic 26RFa neurons are not involved in the central inhibitory effect of insulin on hepatic glucose production, but mediate the central effects of the hormone on its own peripheral production. CONCLUSION/INTERPRETATION: We have identified a novel mechanism in the hypothalamic regulation of glucose homeostasis, the 26RFa/GPR103 system, and we provide evidence that this neuronal peptidergic system is a key relay for the central regulation of glucose metabolism by insulin.

Naringin protects human nucleus pulposus cells against TNF-α-induced inflammation, oxidative stress, and loss of cellular homeostasis by enhancing autophagic flux via AMPK/SIRT1 activation.

Activation of the proinflammatory-associated cytokine, tumor necrosis factor-α (TNF-α), in nucleus pulposus (NP) cells is essential for the pathogenesis of intervertebral disc degeneration (IDD). Restoring autophagic flux has been shown to effectively protect against IDD and is a potential target for treatment. The goal of this study was to explore particular autophagic signalings responsible for the protective effects of naringin, a known autophagy activator, on human NP cells. The results showed that significantly increased autophagic flux was observed in NP cells treated with naringin, with pronounced decreases in the inflammatory response and oxidative stress, which rescued the disturbed cellular homeostasis induced by TNF-α activation. Autophagic flux inhibition was detectable in NP cells cotreated with 3-methyladenine (3-MA, an autophagy inhibitor), partially offsetting naringin-induced beneficial effects. Naringin promoted the expressions of autophagy-associated markers via SIRT1 (silent information regulator-1) activation by AMPK (AMP-activated protein kinase) phosphorylation. Either AMPK inhibition by BML-275 or SIRT1 silencing partially counteracted naringin-induced autophagic flux enhancement. These findings indicate that naringin boosts autophagic flux through SIRT1 upregulation via AMPK activation, thus protecting NP cells against inflammatory response, oxidative stress, and impaired cellular homeostasis. Naringin can be a promising inducer of restoration autophagic flux restoration for IDD.

PD-1/PD-L1 inhibitor ameliorates silica-induced pulmonary fibrosis by maintaining systemic immune homeostasis.

Pulmonary fibrosis induced by silica particles is defined as silicosis, which is an incurable disease. The pathogenesis of silicosis is not completely clear, but it's certain that immune system dysfunction is closely related to it. Immune checkpoint inhibitors (ICIs) are emerging immunotherapeutic agents that mainly target adaptive immune cells, and there is abundant evidence that ICIs are of great value in cancer treatment. However, whether these attractive agents can be implemented in silicosis treatment is unclear. In this study, we explored the efficacy of small molecule inhibitors targeted PD-1/PD-L1 and CTLA-4 on silica-induced pulmonary fibrosis in mice. ICIs were injected intraperitoneally into mice that received silica instillation twice a week. The mice were sacrificed 7 and 28 days after the injection. The lungs, spleen, hilar lymph nodes, thymus, and peripheral blood of mice were collected and subjected to histological examination, flow cytometry analysis, and mRNA and protein quantification. Our results demonstrated that silica exposure caused damage to multiple immune organs in mice, leading to an imbalance in systemic immune homeostasis. Specifically, proportions and subtypes of T and B cells were significantly altered, and the expressions of PD-1, PD-L1 and CTLA-4 were abnormal on these cells. Both PD-1/PD-L1 and CTLA-4 inhibitor administration modulated silica-induced immune system disruption, however, only PD-1/PD-L1 signaling inhibition showed significant amelioration of silicosis. Our findings confirmed for the first time the potential value of ICIs for the treatment of silica-induced pulmonary fibrosis, and this may provide new ideas for the treatment of other fibrosis-related diseases.

sSTEAP4 regulates cellular homeostasis and improves high-fat-diet-caused oxidative stress in hepatocytes.

AIM: Nonalcoholic fatty liver disease (NAFLD) has become a global epidemic, but its pathogenesis is unclear. STEAP4, a member of six transmembrane protein family, integrates inflammatory and metabolic responses. Our present aim is to explore the roles of STEAP4 in maintaining cellular homeostasis and improving high-fat-diet (HFD)-caused oxidative stress in hepatocytes. MAIN METHODS: NAFLD model was established by HFD-feeding mice. The effects of over-nutrition on liver were detected by serum biochemical analysis and bulk RNA-seq. The levels of gene expression were measured by QPCR and Western Blot. Immunofluorescent staining was applied to determine the localization of STEAP4. AMPK agonist was employed to investigate the link between STEAP4 and AMPK pathway. KEY FINDINGS: Sus scrofa STEAP4 (sSTEAP4) relieved oxidative stress and rescued the viability of hepatocytes. sSTEAP4 increased AKT phosphorylation and SOD2 level in hepatocytes, whether or not treated with H2O2, suggesting sSTEAP4 has regulatory effects on insulin signaling and antioxidant pathways. However, sSTEAP4 inhibited AMPK phosphorylation and Beclin1/LC3 expression under H2O2-deficiency situation, but the results were conversed with H2O2 stimulation. The cellular ER stress was aggravated with the increased energy during oxidative stress, indicating that sSTEAP4 might regulate the energetic communication between ER and mitochondria by intervening mitochondrial energy production. In addition, sSTEAP4 was demonstrated to localize in the membranes of plasma and ER in HepG2 hepatocytes. SIGNIFICANCE: Our results reveal that sSTEAP4 based on the needs of cell itself to improve hepatic oxidative stress and HFD-caused NAFLD, which might provide a new therapeutic scheme for NAFLD.

Dietary cadmium induced declined locomotory and reproductive fitness with altered homeostasis of essential elements in Drosophila melanogaster.

Cadmium (Cd) exerts detrimental effects on multiple biological processes of the living organisms along with epigenetic transgenerational effect. Drosophila melanogaster offers unique opportunity to evaluate Cd toxicity when studying important life traits in short duration of time by designing distinct behavioural assays. Present study utilized this model organism to assess Cd induced lethality, retarded growth, decreased life span and altered behaviour of the animals either at larval or adult stage. Our investigations revealed reduced locomotion and reproductive fitness of the animals upon Cd exposure. Transgenerational effect on locomotion was found to be behaviour specific as larval crawling was affected, but adult fly negative geotaxis was comparable to the control. Mechanistically, decreased antioxidant enzymes activity, superoxide dismutase (SOD) and catalase (CAT) together with altered homeostasis of essential elements (Fe, Zn and Mg) may be responsible for the observed effects. Altogether our work showed extensive range of Cd altered Drosophila behaviour which warrants need to control environmental Cd toxicity.

Artesunate induces ferroptosis via modulation of p38 and ERK signaling pathway in glioblastoma cells.

Ferroptosis is implicated in various tumors, including glioblastoma. Artesunate (ART), an anti-malarial drug, exerted antitumor properties in several cancer types. However, the role of ferroptosis in the inhibiting effect of artesunate on glioblastoma remains unclear. The purpose of this study was to investigate the effects of ART on the ferroptosis of glioblastoma and to elucidate the underlying mechanisms. We found that ART inhibited the proliferation of glioblastoma cells in vitro and glioblastoma tumorigenesis in vivo. Characteristic changes of ferroptosis were observed in ART group, including GSH depletion, lipid peroxidation and iron overload. Meanwhile, the protein level of GPX4 were lower in ART group than that in control group. Ferrostatin-1, a ferroptosis inhibitor, could rescue the cell death induced by ART in U251 cells. Further examination of the mechanism revealed that the effect of ART on ferroptosis was partially governed by regulating iron homeostasis and p38 and ERK signaling pathway. These findings support that ART triggers ferroptosis in glioblastoma and might be a potential therapeutic agent for glioblastoma treatment.

Effects of alkaloid-rich extracts obtained from Grifola frondosa on gut microbiota and glucose homeostasis in rats.

Grifola frondosa (GF), also known as maitake (a type of mushroom), has been widely used as a food item and it exhibits various health-beneficial hypoglycemic activities. Rats fed with a fat/high-sucrose-based diet were used to determine the hypoglycemic activity of 95% and 55% GF ethanol extracts (labeled as GF95 and GF55, respectively). The activity was determined by monitoring the fasting blood glucose level. Oral glucose tolerance tests were conducted, and the levels of alanine aminotransferase and aspartate aminotransferase were studied to study the hypoglycemic activity. The HPLC-ESI-TOF-MS technique was used to analyze the samples, and the results revealed that alkaloids were present in abundance in GF95 and GF55. It was also observed that GF55 contained some organic acids and GF95 contained extra small amounts of phenoloid. The levels of intestinal microbiota were analyzed, and the results from transcriptome analysis indicated that GF55 reduced the relative abundance of Romboutsia and affected RT-Db1, thereby improving the extent of glucose metabolism achieved. GF95 downregulated the mRNA level of Socs1 by increasing the levels of Oscillibacter, Butyricimonas, Barnesiella, Turicibacter, Methanosphaera, Asaccharobacter, Globicatella, Bifidobacterium, Allobaculum, and Romboutsia. The expression of Pik3rl was upregulated when the levels of Ruminococcus and Saccharibacteria increased. The hypoglycemic activity was induced under these conditions. The obtained data indicated that the efficiency of GF95 to control glucose levels was higher than the efficiency of GF55. This suggested that GF95 can be potentially used to protect against hyperglycemia.

The Reservoir of Persistent Human Papillomavirus Infection; Strategies for Elimination Using Anti-Viral Therapies.

Human Papillomaviruses have co-evolved with their human host, with each of the over 200 known HPV types infecting distinct epithelial niches to cause diverse disease pathologies. Despite the success of prophylactic vaccines in preventing high-risk HPV infection, the development of HPV anti-viral therapies has been hampered by the lack of enzymatic viral functions, and by difficulties in translating the results of in vitro experiments into clinically useful treatment regimes. In this review, we discuss recent advances in anti-HPV drug development, and highlight the importance of understanding persistent HPV infections for future anti-viral design. In the infected epithelial basal layer, HPV genomes are maintained at a very low copy number, with only limited viral gene expression; factors which allow them to hide from the host immune system. However, HPV gene expression confers an elevated proliferative potential, a delayed commitment to differentiation, and preferential persistence of the infected cell in the epithelial basal layer, when compared to their uninfected neighbours. To a large extent, this is driven by the viral E6 protein, which functions in the HPV life cycle as a modulator of epithelial homeostasis. By targeting HPV gene products involved in the maintenance of the viral reservoir, there appears to be new opportunities for the control or elimination of chronic HPV infections.

Paradoxical neuronal hyperexcitability in a mouse model of mitochondrial pyruvate import deficiency.

Neuronal excitation imposes a high demand of ATP in neurons. Most of the ATP derives primarily from pyruvate-mediated oxidative phosphorylation, a process that relies on import of pyruvate into mitochondria occuring exclusively via the mitochondrial pyruvate carrier (MPC). To investigate whether deficient oxidative phosphorylation impacts neuron excitability, we generated a mouse strain carrying a conditional deletion of MPC1, an essential subunit of the MPC, specifically in adult glutamatergic neurons. We found that, despite decreased levels of oxidative phosphorylation and decreased mitochondrial membrane potential in these excitatory neurons, mice were normal at rest. Surprisingly, in response to mild inhibition of GABA mediated synaptic activity, they rapidly developed severe seizures and died, whereas under similar conditions the behavior of control mice remained unchanged. We report that neurons with a deficient MPC were intrinsically hyperexcitable as a consequence of impaired calcium homeostasis, which reduced M-type potassium channel activity. Provision of ketone bodies restored energy status, calcium homeostasis and M-channel activity and attenuated seizures in animals fed a ketogenic diet. Our results provide an explanation for the seizures that frequently accompany a large number of neuropathologies, including cerebral ischemia and diverse mitochondriopathies, in which neurons experience an energy deficit.

Quaternary ammonium iminofullerenes improve root growth of oxidative-stress maize through ASA-GSH cycle modulating redox homeostasis of roots and ROS-mediated root-hair elongation.

BACKGROUND: Various environmental factors are capable of oxidative stress to result in limiting plant development and agricultural production. Fullerene-based carbon nanomaterials can enable radical scavenging and positively regulate plant growth. Even so, to date, our knowledge about the mechanism of fullerene-based carbon nanomaterials on plant growth and response to oxidative stress is still unclear. RESULTS: 20 or 50 mg/L quaternary ammonium iminofullerenes (IFQA) rescued the reduction in root lengths and root-hair densities and lengths of Arabidopsis and maize induced by accumulation of endogenous hydrogen peroxide (H2O2) under 3-amino-1,2,4-triazole or exogenous H2O2 treatment, as well as the root active absorption area and root activity under exogenous H2O2 treatment. Meanwhile, the downregulated contents of ascorbate acid (ASA) and glutathione (GSH) and the upregulated contents of dehydroascorbic acid (DHA), oxidized glutathione (GSSG), malondialdehyde (MDA), and H2O2 indicated that the exogenous H2O2 treatment induced oxidative stress of maize. Nonetheless, application of IFQA can increase the ratios of ASA/DHA and GSH/GSSG, as well as the activities of glutathione reductase, and ascorbate peroxidase, and decrease the contents of H2O2 and MDA. Moreover, the root lengths were inhibited by buthionine sulfoximine, a specific inhibitor of GSH biosynthesis, and subsequently rescued after addition of IFQA. The results suggested that IFQA could alleviate exogenous-H2O2-induced oxidative stress on maize by regulating the ASA-GSH cycle. Furthermore, IFQA reduced the excess accumulation of ROS in root hairs, as well as the NADPH oxidase activity under H2O2 treatment. The transcript levels of genes affecting ROS-mediated root-hair development, such as RBOH B, RBOH C, PFT1, and PRX59, were significantly induced by H2O2 treatment and then decreased after addition of IFQA. CONCLUSION: The positive effect of fullerene-based carbon nanomaterials on maize-root-hair growth under the induced oxidative stress was discovered. Application IFQA can ameliorate oxidative stress to promote maize-root growth through decreasing NADPH-oxidase activity, improving the scavenging of ROS by ASA-GSH cycle, and regulating the expressions of genes affecting maize-root-hair development. It will enrich more understanding the actual mechanism of fullerene-based nanoelicitors responsible for plant growth promotion and protection from oxidative stress.

Increased energy demand from anabolic-catabolic processes drives ß-lactam antibiotic lethality.

ß-Lactam antibiotics disrupt the assembly of peptidoglycan (PG) within the bacterial cell wall by inhibiting the enzymatic activity of penicillin-binding proteins (PBPs). It was recently shown that ß-lactam treatment initializes a futile cycle of PG synthesis and degradation, highlighting major gaps in our understanding of the lethal effects of PBP inhibition by ß-lactam antibiotics. Here, we assess the downstream metabolic consequences of treatment of Escherichia coli with the ß-lactam mecillinam and show that lethality from PBP2 inhibition is a specific consequence of toxic metabolic shifts induced by energy demand from multiple catabolic and anabolic processes, including accelerated protein synthesis downstream of PG futile cycling. Resource allocation into these processes is coincident with alterations in ATP synthesis and utilization, as well as a broadly dysregulated cellular redox environment. These results indicate that the disruption of normal anabolic-catabolic homeostasis by PBP inhibition is an essential factor for ß-lactam antibiotic lethality.

HDAC6 inhibition reverses long-term doxorubicin-induced cognitive dysfunction by restoring microglia homeostasis and synaptic integrity.

Breast cancer is the most common female malignancy in both the developed and developing world. Doxorubicin is one of the most commonly used chemotherapies for breast cancer. Unfortunately, up to 60% of survivors report long-term chemotherapy-induced cognitive dysfunction (CICD) characterized by deficits in working memory, processing speed and executive function. Currently, no therapeutic standard for treating CICD exists. Here, we hypothesized that treatment with a blood-brain barrier permeable histone deacetylase 6 (HDAC6) inhibitor can successfully reverse long-term doxorubicin-induced cognitive dysfunction. Methods: The puzzle box test and novel object/place recognition test were used to assess cognitive function following a therapeutic doxorubicin dosing schedule in female mice. Mitochondrial function and morphology in neuronal synaptosomes were evaluated using the Seahorse XF24 extracellular flux analyzer and transmission electron microscopy, respectively. Hippocampal postsynaptic integrity was evaluated using immunofluorescence. Hippocampal microglia phenotype was determined using advanced imaging techniques and single-nucleus RNA sequencing. Results: A 14-day treatment with a blood-brain barrier permeable HDAC6 inhibitor successfully reversed long-term CICD in the domains of executive function, working and spatial memory. No significant changes in mitochondrial function or morphology in neuronal synaptosomes were detected. Long-term CICD was associated with a decreased expression of postsynaptic PSD95 in the hippocampus. These changes were associated with decreased microglial ramification and alterations in the microglia transcriptome that suggest a stage 1 disease-associated microglia (DAM) phenotype. HDAC6 inhibition completely reversed these doxorubicin-induced alterations, indicating a restoration of microglial homeostasis. Conclusion: Our results show that decreased postsynaptic integrity and a neurodegenerative microglia phenotype closely resembling stage 1 DAM microglia contribute to long-term CICD. Moreover, HDAC6 inhibition shows promise as an efficacious pharmaceutical intervention to alleviate CICD and improve quality of life of breast cancer survivors.

Treatment with soluble CD24 attenuates COVID-19-associated systemic immunopathology.

BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) through direct lysis of infected lung epithelial cells, which releases damage-associated molecular patterns and induces a pro-inflammatory cytokine milieu causing systemic inflammation. Anti-viral and anti-inflammatory agents have shown limited therapeutic efficacy. Soluble CD24 (CD24Fc) blunts the broad inflammatory response induced by damage-associated molecular patterns via binding to extracellular high mobility group box 1 and heat shock proteins, as well as regulating the downstream Siglec10-Src homology 2 domain-containing phosphatase 1 pathway. A recent randomized phase III trial evaluating CD24Fc for patients with severe COVID-19 (SAC-COVID; NCT04317040) demonstrated encouraging clinical efficacy. METHODS: Using a systems analytical approach, we studied peripheral blood samples obtained from patients enrolled at a single institution in the SAC-COVID trial to discern the impact of CD24Fc treatment on immune homeostasis. We performed high dimensional spectral flow cytometry and measured the levels of a broad array of cytokines and chemokines to discern the impact of CD24Fc treatment on immune homeostasis in patients with COVID-19. RESULTS: Twenty-two patients were enrolled, and the clinical characteristics from the CD24Fc vs. placebo groups were matched. Using high-content spectral flow cytometry and network-level analysis, we found that patients with severe COVID-19 had systemic hyper-activation of multiple cellular compartments, including CD8+ T cells, CD4+ T cells, and CD56+ natural killer cells. Treatment with CD24Fc blunted this systemic inflammation, inducing a return to homeostasis in NK and T cells without compromising the anti-Spike protein antibody response. CD24Fc significantly attenuated the systemic cytokine response and diminished the cytokine coexpression and network connectivity linked with COVID-19 severity and pathogenesis. CONCLUSIONS: Our data demonstrate that CD24Fc rapidly down-modulates systemic inflammation and restores immune homeostasis in SARS-CoV-2-infected individuals, supporting further development of CD24Fc as a novel therapeutic against severe COVID-19.