Remote Ischemic Postconditioning-Mediated Neuroprotection against Stroke by Promoting Ketone Body-Induced Ferroptosis Inhibition.

Neuronal death resulting from ischemic stroke is the primary cause of adult mortality and disability, and effective neuroprotective agents for poststroke intervention are still lacking. Remote ischemic postconditioning (RIPostC) has demonstrated significant protective effects against ischemia in various organs; however, the specific mechanisms are not fully understood. This study investigated the potential neuroprotective mechanisms of RIPostC in the context of ischemic stroke. Using a rat model of middle cerebral artery occlusion, we found that RIPostC mitigated neurological damage, improved movement in the open-field test, and protected against neuronal apoptosis. In terms of energy metabolism, RIPostC enhanced ATP levels, suppressed lactate content, and increased the production of ketone bodies (KBs). In the ferroptosis assay, RIPostC protected against lipoperoxidation, reversed the reduction of glutathione peroxidase 4 (GPX4), and mitigated the excessive expression of long-chain acyl-CoA synthetase family member 4 (ACSL4). In oxygen-glucose deprivation/reoxygenation-treated HT22 cells, KBs maintained GPX4 levels, suppressed ACSL4 expression, and preserved the mitochondrial cristae number. However, the effect of KBs on the expression of GPX4, ACSL4, and the number of mitochondrial cristae was blocked by erastin. Moreover, both RIPostC and KBs reduced total iron and ferrous ion content by repressing iron transporters both in vitro and in vivo. In conclusion, KBs-induced mitigation of ferroptosis could represent a new therapeutic mechanism for RIPostC in treating stroke.

Dynamic defects boost in-situ H2O2 piezocatalysis for water cleanup.

Creating efficient catalysts for simultaneous H2O2 generation and pollutant degradation is vital. Piezocatalytic H2O2 synthesis offers a promising alternative to traditional methods but faces challenges like sacrificial reagents, harsh conditions, and low activity. In this study, we introduce a cobalt-loaded ZnO (CZO) piezocatalyst that efficiently generates H2O2 from H2O and O2 under ultrasonic (US) treatment in ambient aqueous conditions. The catalyst demonstrates exceptional performance with ~50.9% TOC removal of phenol and in situ generation of 1.3 mM H2O2, significantly outperforming pure ZnO. Notably, the CZO piezocatalyst maintains its H2O2 generation capability even after multiple cycles, showing continuous improvement (from 1.3 mM to 1.8 mM). This is attributed to the piezoelectric electrons promoting the generation of dynamic defects under US conditions, which in turn promotes the adsorption and activation of oxygen, thereby facilitating efficient H2O2 production, as confirmed by EPR spectrometry, XPS analysis, and DFT calculations. Moreover, the CZO piezocatalysts maintain outstanding performance in pollutant degradation and H2O2 production even after long periods of inactivity, and the deactivated catalyst due to metal ion dissolution could be rejuvenated by pH adjustment, offering a sustainable solution for wastewater purification.

Effective green treatment of sewage sludge from Fenton reactions: Utilizing MoS2 for sustainable resource recovery.

Effectively managing sewage sludge from Fenton reactions in an eco-friendly way is vital for Fenton technology's viability in pollution treatment. This study focuses on sewage sludge across various treatment stages, including generation, concentration, dehydration, and landfill, and employs chemical composite MoS2 to facilitate green resource utilization of all types of sludge. MoS2, with exposed Mo4+ and low-coordination sulfur, enhances iron cycling and creates an acidic microenvironment on the sludge surface. The MoS2-modified iron sludge exhibits outstanding (>95%) phenol and pollutant degradation in hydrogen peroxide and peroxymonosulfate-based Fenton systems, unlike unmodified sludge. This modified sludge maintains excellent Fenton activity in various water conditions and with multiple anions, allowing extended phenol degradation for over 14 d. Notably, the generated chemical oxygen demand (COD) in sludge modification process can be efficiently eliminated through the Fenton reaction, ensuring effluent COD compliance and enabling eco-friendly sewage sludge resource utilization.

Development and evaluation of a new luciferase immunosorbent assay to detect GII.6 norovirus-specific IgG in different domestic and wild animals.

Noroviruses (NoVs) are the leading viral pathogens globally causing acute gastroenteritis (AGE) in humans, posing a significant global health threat and economic burden. Recent investigations revealed that human NoVs had been detected in different animals, which raises concerns about whether NoVs are potential zoonotic diseases. This study developed a novel luciferase immunosorbent assay (LISA) to detect GII.6 NoV IgG based on P protein of VP1. The LISA showed high specificity (99.20%) and sensitivity (92.00%) with 4-16 times more sensitivity compared with an ELISA. NoV-LISA was reproducible with human serum regarding the inter- and intra-assay coefficient of variance values. Potential cross-reactivity was also evaluated using mice serum immunized by other antigens, which showed that NoV-LISA could differentiate GII.6 NoV from rotavirus and various genotypes of NoV. Specific GII.6 NoV IgG was widely detected in different domestic and wild animals, including dogs, pigs, bats, rats, and home shrews, with various IgG-positive rates ranging from 2.5 to 74.4%. In conclusion, our newly developed NoV-LISA assay is suitable for NoV-specific IgG detection in humans and animals. The wide distribution of IgG antibodies against human NoV indicates potential zoonotic transmission between humans and animals.

Flavonoid profile of Anoectochilus roxburghii (Wall.) Lindl. Under short-term heat stress revealed by integrated metabolome, transcriptome, and biochemical analyses.

Global warming severely threatens plant growth, and could lead to yield reduction. Although findings suggest that flavonoids play important roles in biological process in plants, their response to heat stress in Anoectochilus roxburghii (Wall.) Lindl. remains unclear. Here, we aimed to examine the flavonoid profile of A. roxburghii under heat stress and assess the effect of exogenous application of quercetin on heat stress tolerance. Metabolome analysis showed that quercetin, tricetin, isorhamnetin, scutellarein, and 4',7-Isoflavandiol were the main upregulated flavonoids in A. roxburghii, based on variable importance in the projection >1 and with fold change >2. Determination of the concentrations of the flavonoids using a standard curve revealed that quercetin, kaempferol, and isorhamnetin contents increased by 8.24-, 7.55-, and 5.01-fold, respectively, during heat stress, whereas rutin concentration decreased from 83.04 to 80.89 mg/kg (dry weight). Additionally, transcriptome analysis indicated increased expression of several genes in flavonoid biosynthesis pathways, including phenylalanine ammonia-lyase and chalcone synthase. Moreover, exogenous application of quercetin improved the antioxidant capacity and physiological parameters, including photosynthetic rate and chlorophyll content, of A. roxburghii under heat stress. Overall, the flavonoid profile of A. roxburghii under short-term heat stress was characterized based on integrated metabolomic, transcriptomic, and biochemical analyses, providing new insights for improving the biological value of A. roxburghii.

Single-atom Mo-Co catalyst with low biotoxicity for sustainable degradation of high-ionization-potential organic pollutants.

Single-atom catalysts (SACs) are a promising area in environmental catalysis. We report on a bimetallic Co-Mo SAC that shows excellent performance in activating peroxymonosulfate (PMS) for sustainable degradation of organic pollutants with high ionization potential (IP > 8.5 eV). Density Functional Theory (DFT) calculations and experimental tests demonstrate that the Mo sites in Mo-Co SACs play a critical role in conducting electrons from organic pollutants to Co sites, leading to a 19.4-fold increase in the degradation rate of phenol compared to the CoCl2-PMS group. The bimetallic SACs exhibit excellent catalytic performance even under extreme conditions and show long-term activation in 10-d experiments, efficiently degrading 600 mg/L of phenol. Moreover, the catalyst has negligible toxicity toward MDA-MB-231, Hela, and MCF-7 cells, making it an environmentally friendly option for sustainable water treatment. Our findings have important implications for the design of efficient SACs for environmental remediation and other applications in biology and medicine.

Serological surveillance of GI norovirus reveals persistence of blockade antibody in a Jidong community-based prospective cohort, 2014-2018.

Introduction: Herd immunity against norovirus (NoV) is poorly understood in terms of its serological properties and vaccine designs. The precise neutralizing serological features of genotype I (GI) NoV have not been studied. Methods: To expand insights on vaccine design and herd immunity of NoVs, seroprevalence and seroincidence of NoV genotypes GI.2, GI.3, and GI.9 were determined using blockade antibodies based on a 5-year longitudinal serosurveillance among 449 residents in Jidong community. Results: Correlation between human histo-blood group antigens (HBGAs) and GI NoV, and dynamic and persistency of antibodies were also analyzed. Seroprevalence of GI.2, GI.3, and GI.9 NoV were 15.1%-18.0%, 35.0%-38.8%, and 17.6%-22.0%; seroincidences were 10.0, 21.0, and 11.0 per 100.0 person-year from 2014 to 2018, respectively. Blockade antibodies positive to GI.2 and GI.3 NoV were significantly associated with HBGA phenotypes, including blood types A, B (excluding GI.3), and O+; Lewis phenotypes Leb+/Ley+ and Lea+b+/Lex+y+; and secretors. The overall decay rate of anti-GI.2 antibody was -5.9%/year (95% CI: -7.1% to -4.8%/year), which was significantly faster than that of GI.3 [-3.6%/year (95% CI: -4.6% to -2.6%/year)] and GI.9 strains [-4.0%/year (95% CI: -4.7% to -3.3%/year)]. The duration of anti-GI.2, GI.3, and GI.9 NoV antibodies estimated by generalized linear model (GLM) was approximately 2.3, 4.2, and 4.8 years, respectively. Discussion: In conclusion, enhanced community surveillance of GI NoV is needed, and even one-shot vaccine may provide coast-efficient health benefits against GI NoV infection.

Under-five mortality in Sierra Leone and possible associated factors: evidence from the 2019 Demographic and Health Survey.

High under-five mortality rate remains one of the public health challenges, especially in Sub-Saharan Africa, accounting for more than half of all global cases. Sierra Leone was and is still one of the countries with the highest under-five mortality rate. Using the latest 2019 Sierra Leone Demographic and Health Survey data, we investigated factors associated with under-five mortality in Sierra Leone. A total of 9771 mothers aged 15-49 years in the country were interviewed and included in the analysis. The dependent variable is child status (dead = 1; alive = 0). A total of 871 (9%) children died before their fifth birthday. The maternal age of 20-24 years [adjusted odds ratios (AOR) = 0.46; 95% confidence interval (CI) = 0.33-0.64; P < 0.001] up to 40-44 years (AOR = 0.43; CI = 0.27-0.7; P = 0.001), currently breastfeeding (AOR = 0.20; CI = 0.17-0.24; P < 0.001), maternal media exposure and usage of reading newspapers/magazines less than once a week (AOR = 0.48; CI = 0.28-0.85; P = 0.011) were more likely to enhance child survivability through their fifth birthday. Also, the child sex being female (AOR = 0.68; CI = 0.59-0.79) was more likely to survive under-five mortality compared to their male counterpart. On the other hand, mothers who listened to radio at least once a week (AOR = 1.31; CI = 1.08-1.59; P = 0.007) watched television less than once a week (AOR = 1.48; CI = 1.16-1.90), had two (AOR = 3.4, CI = 2.78-4.16; P < 0.001) or three and above birth (AOR = 8.11; CI = 6.07-10.83; P < 0.001) in five years, had multiple birth children (AOR = 1.41; CI = 1.08-1.86) and very small-sized child at birth (AOR= 1.95; CI = 1.41-2.70) were more likely to lose their children below the age of 5 years. The factors contributing to under-five mortality in Sierra Leone are critical to ensuring child survival and improving maternal health. Breastfeeding, maternal age, media exposure, child's sex, multiple birth type, very small-sized child and the total number of births in 5 years were significant drivers of under-five mortality. The result affirms the need for attention to be focused on enhancing the survival rate of under-five children in Sierra Leone.

Recommendations for the validation of flow cytometric testing during drug development: II assays.

Flow cytometry-based assays serve as valuable tools for various aspects of the drug development process ranging from target discovery and characterization to evaluation of responses in a clinical setting. The integrity of the samples and the appropriate selection and characterization of the reagents used in these assays are in themselves challenging. These concerns taken together with the flow-based technology makes the validation of flow cytometry assays a challenging effort. Therefore, apart from summarizing the role of flow cytometry technology in various stages of drug development, this manuscript focuses on recommendations for the validation of methods applying flow cytometry. Information is also provided on the relevant validation parameters for different types of flow cytometry assays to guide the users of this platform. Together, the recommendations and the information on regulatory guidelines provided in this manuscript represent the consensus of all the authors and can assist the flow cytometry user in implementing the appropriate method validation strategies.

Molecular hallmarks of anti-chromatin antibodies associated with the lupus susceptibility locus, Sle1.

Anti-nuclear antibodies constitute the hallmark of lupus. The NZM2410-derived Sle1 lupus susceptibility interval on murine chromosome 1 breaches tolerance, leading to the emergence of anti-nuclear autoantibodies targeting nucleosomes. However, little is known about the molecular structure of the anti-nucleosome autoantibodies from this genetically simplified mouse model of lupus. In this study, the immunoglobulin heavy chain and light chain sequences of 50 anti-nuclear monoclonal antibodies derived from five B6.Sle1(z) mice were compared to non-nuclear antibody controls. Compared to two different sets of non-nuclear antibodies, anti-nucleosome antibodies derived from B6.Sle1(z) congenic mice exhibited a high degree of clonal expansion and three distinct sequence motifs in their heavy chains - cationic CDR3 stretches, non-anionic CDR2 regions, and an increased frequency of aspartate residues at H50, which together increased the likelihood of an antibody being chromatin-reactive by approximately 4-fold.

Sle1ab mediates the aberrant activation of STAT3 and Ras-ERK signaling pathways in B lymphocytes.

The Sle1ab genomic interval on murine chromosome 1 mediates the loss of immune tolerance to chromatin resulting in antinuclear Abs (ANA) production in the lupus-prone NZM2410 mouse. Global gene expression analysis was used to identify the molecular pathways that are dysregulated at the initiation of B lymphocyte autoimmunity in B6.Sle1ab mice. This analysis identified that STAT3 and ras-ERK signaling pathways are aberrantly activated in Sle1ab B lymphocytes, consistent with increased production of IL-6 by splenic B lymphocytes and monocytes in B6.Sle1ab mice. In vitro treatment of splenic mononuclear cells isolated from ANA-positive Sle1ab mice with anti-IL-6 Ab or AG490, an inhibitor of STAT3 signaling pathway, suppressed ANA production in short-term culture, indicating that this pathway was essential to the production of autoantibodies. In vivo treatment of ANA-positive B6.Sle1ab mice with the ras pathway inhibitor, perillyl alcohol, suppressed the increase of ANA. These findings identify IL-6 as a early key cytokine in Sle1ab-mediated disease development and indicate that the STAT3 and ras-ERK signaling pathways are potential therapeutic targets for treating systemic lupus erythematosus.

Pathogenic profiles and molecular signatures of antinuclear autoantibodies rescued from NZM2410 lupus mice.

Two outstanding questions concerning antinuclear antibodies (ANAs) in lupus involve their pathogenic potential and their molecular signatures. To address these questions, a panel of 56 antinuclear and 47 nonnuclear binding monoclonal antibodies was rescued from four seropositive NZM2410 lupus mice. The monoclonals varied in their reactivity to nucleosomes, ssDNA, dsDNA, and glomerular substrate. A large fraction of the antibodies demonstrated apparent polyreactivity (to DNA, histones, and glomerular antigens) due to bound, DNase-1 sensitive nuclear antigenic bridges. Although nephrophilic immunoglobulin (Ig) M and IgG antibodies were the most pathogenic, the dsDNA-binding antibodies were modestly so; in contrast, antinucleosome antibodies were clearly not pathogenic. Compared with the nonnuclear antigen-binding monoclonal antibodies rescued from the same mice, ANAs exhibited increased utilization of VH5/7183 genes and highly cationic heavy chain (HC) CDR3 regions. Most intriguingly, the CDR3 regions of the ANAs exhibited alternating arginine/lysine peaks at H96, H98, and H100, with neutral troughs at H95, H97, and H99. To summarize, glomerular-binding anti-dsDNA antibodies appear to be the most pathogenic variety of lupus autoantibodies. The presence of an alternating charge pattern in their HC CDR3 regions appears to be a prominent hallmark of ANAs.

A murine locus on chromosome 18 controls NKT cell homeostasis and Th cell differentiation.

Th cell differentiation is a critical event in the adaptive immune response. C57BL strains develop predominant Th1 responses while BALB/c develops a predominant Th2 response. To identify quantitative trait loci controlling this variation, we performed Th1/Th2 differentiation assays of F(1) x BALB/c progeny. A single strong quantitative trait locus was identified on chromosome 18, with weaker effects detectable on chromosomes 5, 12, and 14. By preparing a congenic BALB.B10.D2c18 strain, we were able to demonstrate that this single locus was sufficient to "repolarize" spleen cell cultures. This difference was not due to intrinsic differences in CD4(+) T cells. Rather, introgression of the chromosome 18 locus into BALB/c disrupted Va14Ja18 NKT cell homeostasis resulting in the almost complete absence of this T cell subset. Taken together, these data indicate that genes within chromosome 18 control strain-dependent development of Va14Ja18 NKT cells.

Molecular signatures of anti-nuclear antibodies: contributions of specific light chain residues and a novel New Zealand Black V kappa 1 germline gene.

Although the Ig H chains of anti-nuclear Abs (ANA) have been described to possess certain shared molecular signatures, it remains unclear whether the L chains of these Abs also possess distinctive molecular features. The present study examines this by generating and analyzing two comprehensive murine Ig L chain databases, one consisting of 264 monoclonal ANAs and the other consisting of 145 non-ANAs, drawn from previously published work. Importantly, clonal replicates were represented only once each, so as to minimize bias. ANAs and non-ANAs did not differ in Vkappa family or Jkappa gene usage, nor in their mutation frequencies. Interestingly, the L chains of ANAs exhibited differential usage of certain complementarity-determining region residues, arising almost entirely from the increased usage of certain Vkappa germline genes, notably, Vkappa ai4 among anti-dsDNA ANAs, Vkappa23-45 among anti-ssDNA ANAs, and Vkappa21-12 among non-ANAs. Finally, prompted by the increased prevalence of a particular Vkappa1 family sequence among ANAs, we proceeded to clone a novel New Zealand Black Vkappa1 germline gene, named bb1.1, which appears to be frequently used to encoded anti-ssDNA Abs. Collectively, these studies underline the potential contribution of particular Vkappa germline genes in promoting or thwarting DNA binding.

Use of a novel elution regimen reveals the dominance of polyreactive antinuclear autoantibodies in lupus kidneys.

OBJECTIVE: The autoantibody specificities that dominate the deposits in lupus kidneys remain unclear. Reasoning that previously utilized elution buffers such as acidic glycine and ammonium thiocyanate may not have been maximally effective in eluting all Ig deposits from the kidneys, this study was conducted to experiment with a stronger dissociating agent, urea-glycine. METHODS: Seven antinuclear antibody-positive, nephritic female (SWR x NZB)F(1) (SNF1) lupus mice were selected for the elution study. Deposited Ig was eluted from their kidneys using 3 different elution buffers: 0.15M glycine-HCl buffer, 1.3M ammonia thiocyanate/0.15M glycine-HCl buffer, and 5M urea/0.15M glycine-HCl buffer. All eluates were tested for specificity against a variety of nuclear and glomerular antigens. RESULTS: Compared with conventional elution buffers, the urea-based regimen eluted severalfold more IgG and IgM antinuclear antibodies from the kidneys of nephritic SNF1 lupus mice. IgG anti-double-stranded DNA (anti-dsDNA) antibodies were not only the most prevalent species in these renal deposits, they were also heavily enriched in the kidneys, relative to the corresponding serum levels. A substantial fraction of the anti-single-stranded DNA and antihistone/DNA (but not antihistone) reactivity in these eluates was due to cross-reactive anti-dsDNA antibodies. No reactivity with SSA, SSB, Sm, RNP, Jo-1, Scl-70, or ribosomal P antigens could be demonstrated in these eluates. Importantly, the urea-glycine eluates differed from the conventional eluates in having significantly greater reactivity to glomerular substrate and laminin. CONCLUSION: This novel urea-based elution provides further support for the dominance of antibodies in lupus kidneys, with strong polyreactivity to DNA and glomerular substrate.