Cryo-EM structure of SARS-CoV-2 postfusion spike in membrane.

The entry of SARS-CoV-2 into host cells depends on the refolding of the virus-encoded spike protein from a prefusion conformation, which is metastable after cleavage, to a lower-energy stable postfusion conformation1,2. This transition overcomes kinetic barriers for fusion of viral and target cell membranes3,4. Here we report a cryogenic electron microscopy (cryo-EM) structure of the intact postfusion spike in a lipid bilayer that represents the single-membrane product of the fusion reaction. The structure provides structural definition of the functionally critical membrane-interacting segments, including the fusion peptide and transmembrane anchor. The internal fusion peptide forms a hairpin-like wedge that spans almost the entire lipid bilayer and the transmembrane segment wraps around the fusion peptide at the last stage of membrane fusion. These results advance our understanding of the spike protein in a membrane environment and may guide development of intervention strategies.

Directed Differentiation of Human Induced Pluripotent Stem Cells to Heart Valve Cells.

BACKGROUND: A main obstacle in current valvular heart disease research is the lack of high-quality homogeneous functional heart valve cells. Human induced pluripotent stem cells (hiPSCs)-derived heart valve cells may help with this dilemma. However, there are no well-established protocols to induce hiPSCs to differentiate into functional heart valve cells, and the networks that mediate the differentiation have not been fully elucidated. METHODS: To generate heart valve cells from hiPSCs, we sequentially activated the Wnt, BMP4, VEGF (vascular endothelial growth factor), and NFATc1 signaling pathways using CHIR-99021, BMP4, VEGF-165, and forskolin, respectively. The transcriptional and functional similarity of hiPSC-derived heart valve cells compared with primary heart valve cells were characterized. Longitudinal single-cell RNA sequencing was used to uncover the trajectory, switch genes, pathways, and transcription factors of the differentiation. RESULTS: An efficient protocol was developed to induce hiPSCs to differentiate into functional hiPSC-derived valve endothelial-like cells and hiPSC-derived valve interstitial-like cells. After 6-day differentiation and CD144 magnetic bead sorting, ≈70% CD144+ cells and 30% CD144- cells were obtained. On the basis of single-cell RNA sequencing data, the CD144+ cells and CD144- cells were found to be highly similar to primary heart valve endothelial cells and primary heart valve interstitial cells in gene expression profile. Furthermore, CD144+ cells had the typical function of primary heart valve endothelial cells, including tube formation, uptake of low-density lipoprotein, generation of endothelial nitric oxide synthase, and response to shear stress. Meanwhile, CD144- cells could secret collagen and matrix metalloproteinases, and differentiate into osteogenic or adipogenic lineages like primary heart valve interstitial cells. Therefore, we identified CD144+ cells and CD144- cells as hiPSC-derived valve endothelial-like cells and hiPSC-derived valve interstitial-like cells, respectively. Using single-cell RNA sequencing analysis, we demonstrated that the trajectory of heart valve cell differentiation was consistent with embryonic valve development. We identified the main switch genes (NOTCH1, HEY1, and MEF2C), signaling pathways (TGF-ß, Wnt, and NOTCH), and transcription factors (MSX1, SP5, and MECOM) that mediated the differentiation. Finally, we found that hiPSC-derived valve interstitial-like cells might derive from hiPSC-derived valve endothelial-like cells undergoing endocardial-mesenchymal transition. CONCLUSIONS: In summary, this is the first study to report an efficient strategy to generate functional hiPSC-derived valve endothelial-like cells and hiPSC-derived valve interstitial-like cells from hiPSCs, as well as to elucidate the differentiation trajectory and transcriptional dynamics of hiPSCs differentiated into heart valve cells.

The Arabidopsis pre-mRNA 3' end processing related protein FIP1 promotes seed dormancy via the DOG1 and ABA pathways.

Seed dormancy is an important adaptive trait to prevent germination occurring at an inappropriate time. The mechanisms governing seed dormancy and germination are complex. Here, we report that FACTOR INTERACTING WITH POLY(A) POLYMERASE 1 (FIP1), a component of the pre-mRNA 3' end processing machinery, is involved in seed dormancy and germination processes in Arabidopsis thaliana. FIP1 is mainly expressed in seeds and the knockout of FIP1 causes reduced seed dormancy, indicating that FIP1 positively influences seed dormancy. Meanwhile, fip1 mutants are insensitive to exogenous ABA during seed germination and early seedling establishment. The terms 'seed maturation' and 'response to ABA stimulus' are significantly enriched in a gene ontology analysis based on genes differentially expressed between fip1-1 and the wild type. Several of these genes, including ABI5, DOG1 and PYL12, show significantly decreased transcript levels in fip1. Genetic analysis showed that either cyp707a2 or dog1-5 partially, but in combination completely, represses the reduced seed dormancy of fip1, indicating that the double mutant cyp707a2 dog1-5 is epistatic to fip1. Moreover, FIP1 is required for CFIM59, another component of pre-mRNA 3' end processing machinery, to govern seed dormancy and germination. Overall, we identified FIP1 as a regulator of seed dormancy and germination that plays a crucial role in governing these processes through the DOG1 and ABA pathways.

Metabolomic and transcriptomic analyses of peach leaves and fruits in response to pruning.

BACKGROUND: Pruning is an important cultivation management option that has important effects on peach yield and quality. However, the effects of pruning on the overall genetic and metabolic changes in peach leaves and fruits are poorly understood. RESULTS: The transcriptomic and metabolomic profiles of leaves and fruits from trees subjected to pruning and unpruning treatments were measured. A total of 20,633 genes and 622 metabolites were detected. Compared with those in the control, 1,127 differentially expressed genes (DEGs) and 77 differentially expressed metabolites (DEMs) were identified in leaves from pruned and unpruned trees (pdLvsupdL), whereas 423 DEGs and 29 DEMs were identified in fruits from the pairwise comparison pdFvsupdF. The content of three auxin analogues was upregulated in the leaves of pruned trees, the content of all flavonoids detected in the leaves decreased, and the expression of almost all genes involved in the flavonoid biosynthesis pathway decreased. The phenolic acid and amino acid metabolites detected in fruits from pruned trees were downregulated, and all terpenoids were upregulated. The correlation analysis revealed that DEGs and DEMs in leaves were enriched in tryptophan metabolism, auxin signal transduction, and flavonoid biosynthesis. DEGs and DEMs in fruits were enriched in flavonoid and phenylpropanoid biosynthesis, as well as L-glutamic acid biosynthesis. CONCLUSIONS: Pruning has different effects on the leaves and fruits of peach trees, affecting mainly the secondary metabolism and hormone signalling pathways in leaves and amino acid biosynthesis in fruits.

WOX2 functions redundantly with WOX1 and WOX4 to positively regulate seed germination in Arabidopsis.

MAIN CONCLUSION: WOX family gene WOX2 is highly expressed during seed development, which functions redundantly with WOX1 and WOX4 to positively regulate seed germination. WOX (WUSCHEL-related homeobox) is a family of transcription factors in plants. They play essential roles in the regulation of plant growth and development, but their function in seed germination is not well understood. In this report, we show that WOX1, WOX2, and WOX4 are close homologues in Arabidopsis. WOX2 has a redundant function with WOX1 and WOX4, respectively, in seed germination. WOX2 is highly expressed during seed development, from the globular embryonic stage to mature dry seeds, and its expression is decreased after germination. Loss of function single mutant wox2, and double mutants wox1 wox2 and wox2 wox4-1 show decreased germination speed. WOX2 and WOX4 are essential for hypocotyl-radicle zone elongation during germination, potentially by promoting the expression of cell wall-related genes. We also found that WOX2 and WOX4 regulate germination through the gibberellin (GA) pathway. These results suggest that WOX2 and WOX4 integrate the GA pathway and downstream cell wall-related genes during germination.

Reduced NR2F2 Expression in the Host Response to Infectious Bursal Disease Virus Infection Suppressed Viral Replication by Enhancing Type I Interferon Expression by Targeting SOCS5.

Nuclear receptors are ligand-activated transcription factors that play an important role in regulating innate antiviral immunity and other biological processes. However, the role of nuclear receptors in the host response to infectious bursal disease virus (IBDV) infection remains elusive. In this study, we show that IBDV infection or poly(I·C) treatment of DF-1 or HD11 cells markedly decreased nuclear receptor subfamily 2 group F member 2 (NR2F2) expression. Surprisingly, knockdown, knockout, or inhibition of NR2F2 expression in host cells remarkably inhibited IBDV replication and promoted IBDV/poly(I·C)-induced type I interferon and interferon-stimulated genes expression. Furthermore, our data show that NR2F2 negatively regulates the antiviral innate immune response by promoting the suppressor of cytokine signaling 5 (SOCS5) expression. Thus, reduced NR2F2 expression in the host response to IBDV infection inhibited viral replication by enhancing the expression of type I interferon by targeting SOCS5. These findings reveal that NR2F2 plays a crucial role in antiviral innate immunity, furthering our understanding of the mechanism underlying the host response to viral infection. IMPORTANCE Infectious bursal disease (IBD) is an immunosuppressive disease causing considerable economic losses to the poultry industry worldwide. Nuclear receptors play an important role in regulating innate antiviral immunity. However, the role of nuclear receptors in the host response to IBD virus (IBDV) infection remains elusive. Here, we report that NR2F2 expression decreased in IBDV-infected cells, which consequently reduced SOCS5 expression, promoted type I interferon expression, and suppressed IBDV infection. Thus, NR2F2 serves as a negative factor in the host response to IBDV infection by regulating SOCS5 expression, and intervention in the NR2F2-mediated host response by specific inhibitors might be employed as a strategy for prevention and treatment of IBD.

Critical Role of Viral Protein Hexon in Hypervirulent Fowl Adenovirus Serotype-4-Induced Autophagy by Interaction with BAG3 and Promotion of Viral Replication in LMH Cells.

Hepatitis-pericardial syndrome (HHS) is an acute highly infectious avian disease caused by fowl adenovirus serotype 4 (FAdV-4), characterized by fulminant hepatitis and hydropericardium in broilers. Since 2015, a widespread epidemic has occurred in China due to the emergence of hypervirulent FAdV-4 (HPFAdV-4), causing huge losses to the stakeholders. However, the pathogenesis of HPFAdV-4 and the host responses to its infection remain elusive. Here, we show that infection of leghorn male hepatocellular (LMH) cells by HPFAdV-4 induced complete autophagy in cells and that the autophagy induced by recombinant HPFAdV-4-ON1 (rHPFAdV-4-ON1), a viral strain generated by replacing the hexon gene of wild-type HPFAdV-4 (HPFAdV-4-WT) with the one of nonpathogenic strain FAdV-4-ON1, was remarkably mitigated compared to that of the rHPFAdV-4-WT control, suggesting that HPFAdV-4 hexon is responsible for virus-induced autophagy. Importantly, we found that hexon interacted with a cellular protein, BAG3, a host protein that initiates autophagy, and that BAG3 expression increased in cells infected with HPFAdV-4. Furthermore, knockdown of BAG3 by RNA interference (RNAi) significantly inhibited HPFAdV-4- or hexon-induced autophagy and suppressed viral replication. On the contrary, expression of hexon markedly upregulated the expression of BAG3 via activating the P38 signaling pathway, triggering autophagy. Thus, these findings reveal that HPFAdV-4 hexon interacts with the host protein BAG3 and promotes BAG3 expression by activating P38 signaling pathway, thereby inducing autophagy and enhancing viral proliferation, which immensely furthers our understanding of the pathogenesis of HPFAdV-4 infection. IMPORTANCE HHS, mainly caused by HPFAdV-4, has caused large economic losses to the stakeholders in recent years. Infection of leghorn male hepatocellular (LMH) cells by HPFAdV-4 induced complete autophagy that is essential for HPFAdV-4 replication. By a screening strategy, the viral protein hexon was found responsible for virus-induced autophagy in cells. Importantly, hexon was identified as a factor promoting viral replication by interaction with BAG3, an initiator of host cell autophagy. These findings will help us to better understand the host response to HPFAdV-4 infection, providing a novel insight into the pathogenesis of HPFAdV-4 infection.

Type 1 diabetes, its complications, and non-ischemic cardiomyopathy: a mendelian randomization study of European ancestry.

BACKGROUND: Type 1 diabetes (T1D) is a significant risk factor for a range of cardiovascular diseases. Nonetheless, the causal relationship between T1D and non-ischemic cardiomyopathy (NICM) remains to be elucidated. Furthermore, the mechanisms responsible for the progression from T1D to NICM have not been definitively characterized. OBJECTIVE: The aim of this study was to conduct a Mendelian randomization (MR) study to investigate the causal effects of T1D and its complications on the development of NICM. Additionally, this study aimed to conduct a mediation analysis to identify potential mediators within this correlation. METHODS: Genetic variants were used as instrumental variables for T1D. The summary data for T1D were obtained from two genome-wide association study datasets. The summary data for T1D with complications and NICM were obtained from the Finnish database. Two-sample MR, multivariable MR and mediation MR were conducted in this study. RESULTS: The study revealed a causal association between T1D, T1D with complications, and NICM (with odds ratios of 1.02, 95% CI 1.01-1.04, p = 1.17e-04 and 1.03, 95% CI 1.01-1.05, p = 3.15e-3). Even after adjusting for confounding factors such as body mass index and hypertension, T1D remained statistically significant (with odds ratio of 1.02, 95% CI 1.01-1.04, p = 1.35e-4). Mediation analysis indicated that monokine induced by gamma interferon may play a mediating role in the pathogenesis of T1D-NICM (mediation effect indicated by odds ratio of 1.005, 95% CI 1.001-1.01, p = 4.9e-2). CONCLUSION: The study demonstrates a causal relationship between T1D, its complications, and NICM. Additionally, monokine induced by gamma interferon may act as a potential mediator in the pathogenesis of T1D-NICM.

The methodological quality of systematic reviews regarding the Core Outcome Set (COS) development.

BACKGROUND: The Core Outcome Measures in Effectiveness Trials (COMET) working group proposed core outcome sets (COS) to address the heterogeneity in outcome measures in clinical studies. According to the recommendations of COMET, performing systematic reviews (SRs) usually was the first step for COS development. However, the SRs that serve as a basis for COS are not specifically appraised by organizations such as COMET regarding their quality. Here, we investigated the status of SRs related to development of COS and evaluated their methodological quality. METHODS: We conducted a search on PubMed to identify SRs related to COS development published from inception to May 2022. We qualitatively summarized the disease included in SR topics, and the studies included in the SRs. We evaluated the methodological quality of the SRs using AMSTAR 2.0 and compared the overall quality of SRs with and without protocols using the Mann-Whitney U test. RESULTS: We included 175 SRs from 23 different countries or regions, and they mainly focused on five diseases: musculoskeletal system or connective tissue disease (n = 19, 10.86%), injury, poisoning, or certain other consequences of external causes (n = 18, 10.29%), digestive system disease (n = 16, 9.14%), nervous system disease (n = 15, 8.57%), and genitourinary system disease (n = 15, 8.57%). Although 88.00% of SRs included randomized controlled trials (RCTs), only a few SRs (23.38%) employed appropriate tools to assess the risk of bias in RCTs. The assessment results on the basis of AMSTAR 2.0 indicated that most SRs (93.71%) were rated as ''critically low'' to ''low'' in terms of overall confidence. The overall confidence of SRs with protocols was significantly higher than that without protocols (P <.001). Compared to the SRs with protocols on Core Outcome Measures in Effectiveness Trials (COMET), SRs with protocols on PROSPERO were of better overall confidence (P = .017). CONCLUSION: The overall quality of published SRs regarding COS development was poor. Our findings emphasize the need for researchers to carefully select the disease topic and strictly adhere to the requirements of optimal methodology when conducting a SR for the establishment of a COS.

Complexation of Hexavalent Neptunium(VI) with Oxydiacetic Acid and Its Amide Derivatives in Aqueous Solution: Spectrophotometry and DFT Calculations.

Unfolding the solution coordination chemistry of high-valent transuranium elements with the "CHON"-type ligands is important to understand the fundamental chemistry of actinides and to design more efficient extractants for partitioning of transuranium elements in advanced nuclear fuel cycles. Here, the complexation of a hexavalent neptunyl ion (NpO22+ or Np(VI)) with oxydiacetic acid (ODA) has been systematically investigated in comparison with its amide analogues N,N-dimethyl-3-oxa-glutaramic acid (DMOGA) and N,N,N',N'-tetramethyl-3-oxa-glutaramide (TMOGA) both experimentally and computationally. The formation of both 1:1 and 1:2 complexes between Np(VI) and the three ligands was identified by spectrophotometry, and their stability constants were obtained and compared with those of hexavalent U(VI) and Pu(VI). The corresponding bonding nature is elucidated by using energy decomposition analysis (EDA), electrostatic potential (ESP), ELF contours, and natural orbitals for chemical valence (NOCV) methods, which shows that the Np-O bonds are essentially ionic in character and the unoccupied 6d orbitals of Np play a key role in enhancing the covalent interactions between Np(VI) and the three ligands.

Amine-Terminated Phenanthroline Diimides as Aqueous Masking Agents for Am(III)/Eu(III) Separation: An Alternative Ligand Design Strategy for Water-Soluble Lanthanide/Actinide Chelating Ligands.

Selective actinide coordination (from lanthanides) is critical for both nuclear waste management and sustainable development of nuclear power. Hydrophilic ligands used as masking agents to withhold actinides in the aqueous phase are currently highly pursued, while synthetic accessibility, water solubility, acid resistance, and extraction capability are the remaining problems. Most reported hydrophilic ligands are only effective at low acidity. We recently proved that the phenanthroline diimide skeleton was an efficient building block for the construction of highly efficient acid-resistant hydrophilic lanthanide/actinide separation agents, while the limited water solubility hindered the loading capability of the ligand. Herein, amine was introduced as the terminal solubilizing group onto the phenanthroline diimide backbone, which after protonation in acid showed high water solubility. The positively charged terminal amines enhanced the ligand water solubility to a large extent, which, on the other side, was believed to be detrimental for the coordination and complexation of the metal cations. We showed that by delicately adjusting the alkyl chain spacing, this intuitive disadvantage could be relieved and superior extraction performances could be achieved. This work holds significance for both hydrophilic lanthanide/actinide separation ligand design and, concurrently, offers insights into the development of water-soluble lanthanide/actinide complexes for biomedical and bioimaging applications.

Study on interface engineering and chemical bonding of the ReS2@ZnO heterointerface for efficient charge transfer and nonlinear optical conversion efficiency.

Rhenium sulfide (ReS2) has emerged as a promising two-dimensional material, demonstrating broad-spectrum visible absorption properties that make it highly relevant for diverse optoelectronic applications. Manipulating and optimizing the pathway of photogenerated carriers play a pivotal role in enhancing the efficiency of charge separation and transfer in novel semiconductor composites. This study focuses on the strategic construction of a semiconductor heterostructure by synthesizing ZnO on vacancy-containing ReS2 (VRe-ReS2) through chemical bonding processes. The ingeniously engineered built-in electric field within the heterostructure effectively suppresses the recombination of photogenerated electron-hole pairs. A direct and well-established interfacial connection between VRe-ReS2 and ZnO is achieved through a robust Zn-S bond. This distinctive bond configuration leads to enhanced nonlinear optical conversion efficiency, attributed to shortened carrier migration distances and accelerated charge transfer rates. Furthermore, theoretical calculations unveil the superior chemical interactions between Re vacancies and sulfide moieties, facilitating the formation of Zn-S bonds. The photoluminescence (PL) intensity is increased by the formation of VRe-ReS2 and ZnO heterostructure and the PL quantum yield of VRe-ReS2 is improved. The intricate impact of the Zn-S bond on the nonlinear absorption behavior of the VRe-ReS2@ZnO heterostructure is systematically investigated using femtosecond Z-scan techniques. The charge transfer from ZnO to ReS2 defect levels induces a transition from saturable absorption to reverse saturable absorption in the VRe-ReS2@ZnO heterostructure. Transient absorption measurements further confirm the presence of the Zn-S bond between the interfaces, as evidenced by the prolonged relaxation time (τ3) in the VRe-ReS2@ZnO heterostructure. This study offers valuable insights into the rational construction of heterojunctions through tailored interfacial bonding and surface/interface charge transfer pathways. These endeavors facilitate the modulation of electron transfer dynamics, ultimately yielding superior nonlinear optical conversion efficiency and effective charge regulation in optoelectronic functional materials.

Outcomes of antiretroviral treatment for 0-14-year-old children living with HIV in Ganzhou, China, 2006-2023.

BACKGROUND: Studies on antiretroviral therapy (ART) in children living with HIV (CLHIV) are limited due to the small population and low accession rate of ART. METHODS: All 0-14-year-old CLHIV admitted to the Ganzhou Center for Disease Control and Prevention from January 2006 to June 2023 were included retrospectively. The information of treatment regimens, disease progression, and laboratory tests of the patients under ART were used to explore the outcomes and impacts of long-term ART. The normality of all the data was tested by the Shapiro-Wilk test. RESULTS: From 2006 to 2023, 18 CLHIV were reported in Ganzhou. Among them, 11 received ART and were followed up for 60.0 ± 48.4 months. After receiving ART, the median viral load of them decreased from 89,600 copies/ml to 22 copies/ml (P = 0.007), the median CD4+ T cell count increased from 380.7 cells/µL to 661.9 cells/µL (P = 0.028), and the median CD8+ T cell count decreased from 1065.8 cells/µL to 983.3 cells/µL (P = 0.584). The laboratory test results regarding liver function, renal function, blood cell count, and glucolipid metabolism tended to be within normal reference ranges, and the mean height-for-age z-score and weight-for-age z-score increased. However, all the three CLHIV who received cotrimoxazole developed pneumocystis carinii pneumonia, upper respiratory infection, skin lesions, bacterial pneumonia and/or thrush; the mean body-mass-index-for-age z-score decreased from 0.52 to -0.63. CONCLUSION: For CLHIV, ART could effectively inhibit the replication of HIV and improve the immune function of patients. More studies that focus on ART in CLHIV are urgently needed.

Curative Effect of Bracketless and Invisible Orthodontic Treatment for Periodontitis and the Influence on Gingival Crevicular Fluid and Serum IL-6, MMP-8 and TNF-α Levels.

Objective: To observe the therapeutic effects of bracketless and invisible orthodontic treatment on periodontitis, as well as on gingival crevicular fluid and serum interleukin-6 (IL-6), matrix metalloproteinase-8 (MMP-8) and tumors. The impact of necrosis factor-alpha (TNF-α) levels fills the current knowledge gap regarding the impact of different orthodontic treatment modalities on biomarker levels in periodontitis patients. Methods: 100 patients with malocclusion secondary to periodontitis were selected as subjects.They were divided into a control group (n=50) and a study group (n=50) according to the random number method. The control group was treated with a straight wire appliances, and the study group was given bracketless and invisible orthodontic treatment. Clinical effects, Periodontal indicators [plaque index (PLI), gingival crevicular bleeding index (SBI), gingival index (GI), periodontal pocket probe depth (PD), clinical attachment loss (CAL)], gingival crevicular fluid and serum IL-6, MMP-8 and TNF-α levels and the incidence of adverse reactions were compared between the two groups. The uniqueness of this method is that it compares the impact of traditional straight-wire orthodontic treatment and invisible orthodontic treatment without brackets on biomarker levels and clinical effects in patients with periodontitis. In order to understand the role of orthodontic treatment methods in Provides useful information for use in periodontitis treatment. Results: The main findings of this study highlight the significant impact of bracketless clear braces in improving periodontal indicators and cytokine levels. Patients treated with bracketless clear braces demonstrate better clinical outcomes in periodontitis treatment compared with traditional straight-wire orthodontic treatment. The response rate of the study group was higher than that of the control group (94.00% vs. 72.00%) (P < .05). After 2 years of treatment, PLT, SBI, GI, PD and CAL were decreased in both groups and the observation group was significantly lower than the control group (P < .05). After 6 months of treatment, the levels of IL-6, MMP-8 and TNF-α in gingival crevicular fluid and serum were decreased in both groups, and the observation group was significantly lower than the control group (P < .05). There was no significant difference in the incidence of adverse reactions between the two groups (P > .05). Conclusion: The treatment of periodontitis without brackets has a significant effect, which can improve the periodontal condition and reduce the levels of IL-6, MMP-8 and TNF-α in gingival crevicular fluid and serum. Bracketless invisible braces have shown potential clinical significance in improving periodontal indicators and cytokine levels in patients with periodontitis, providing support for providing more comfortable and effective orthodontic treatment options, which may help promote patients' Oral health. These findings suggest the positive role of bracketless invisible braces in comprehensive periodontal treatment, which is expected to influence the practice of orthodontics and periodontal treatment and improve patient treatment experience and effects.

An analysis of the prognostic role of reactive oxygen species-associated genes in breast cancer.

BACKGROUND: This study aimed to type breast cancer in relation to reactive oxygen species (ROS), clinical indicators, single nucleotide variant (SNV) mutations, functional differences, immune infiltration, and predictive responses to immunotherapy or chemotherapy, and constructing a prognostic model. METHODS: We used uniCox analysis, ConsensusClusterPlus, and the proportion of ambiguous clustering (PAC) to analyze The Cancer Genome Atlas (TCGA) data to determine optimal groupings and obtain differentially expressed ROS-related genes. Clinical indicators were then combined with the classification results and the Chi-square test was used to assess differences. We further examined SNV mutations, and functional differences using gene set enrichment analysis (GSEA) analysis, the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, immune cell infiltration, and response to immunotherapy and chemotherapy. A prognostic model for breast cancer was constructed using these differentially expressed genes, immunotherapy or chemotherapy responses, and survival curves. RT-qPCR was used to detect the differences in the expression of LCE3D, CA1, PIRT and SMR3A in breast cancer cell lines and normal breast epithelial cell line. RESULTS: We identified two distinct tumor types with significant differences in ROS-related gene expression, clinical indicators, SNV mutations, functional pathways, and immune infiltration. The response to specific chemotherapy drugs and immunotherapy treatments also documented significant differences. The prognostic model constructed with 16 genes linked to survival could efficiently divide patients into high- and low-risk groups. The high-risk group showed a poorer prognosis, higher tumor purity, distinct immune microenvironment, and lower immunotherapy response. RT-qPCR results showed that LCE3D, CA1, PIRT and SMR3A are highly expressed in breast cancer. CONCLUSION: Our methodical examination presented an enhanced insight into the molecular and immunological heterogeneity of breast cancer. It can contribute to the understanding of prognosis and offer valuable insights for personalized treatment strategies. Further, the prognostic model can potentially serve as a powerful tool for risk stratification and therapeutic decision-making in clinical settings.

KYNA Ameliorates Glutamate Toxicity of HAND by Enhancing Glutamate Uptake in A2 Astrocytes.

Reactive astrocytes are key players in HIV-associated neurocognitive disorders (HAND), and different types of reactive astrocytes play opposing roles in the neuropathologic progression of HAND. A recent study by our group found that gp120 mediates A1 astrocytes (neurotoxicity), which secrete proinflammatory factors and promote HAND disease progression. Here, by comparing the expression of A2 astrocyte (neuroprotective) markers in the brains of gp120 tgm mice and gp120+/α7nAChR-/- mice, we found that inhibition of alpha 7 nicotinic acetylcholine receptor (α7nAChR) promotes A2 astrocyte generation. Notably, kynurenine acid (KYNA) is an antagonist of α7nAChR, and is able to promote the formation of A2 astrocytes, the secretion of neurotrophic factors, and the enhancement of glutamate uptake through blocking the activation of α7nAChR/NF-κB signaling. In addition, learning, memory and mood disorders were significantly improved in gp120 tgm mice by intraperitoneal injection of kynurenine (KYN) and probenecid (PROB). Meanwhile, the number of A2 astrocytes in the mouse brain was significantly increased and glutamate toxicity was reduced. Taken together, KYNA was able to promote A2 astrocyte production and neurotrophic factor secretion, reduce glutamate toxicity, and ameliorate gp120-induced neuropathological deficits. These findings contribute to our understanding of the role that reactive astrocytes play in the development of HAND pathology and provide new evidence for the treatment of HAND via the tryptophan pathway.

Meta-analyses of the relationship between five CXCL8 gene polymorphisms and overall cancer risk, and a case-control study of oral cancer.

BACKGROUND: C-X-C motif chemokine ligand (CXCL8), also known as interleukin-8, is a prototypical CXC family chemokine bearing a glutamic acid-leucine-arginine (ELR) motif that plays key roles in the onset and progression of a range of cancers in humans. Many prior studies have focused on exploring the relationship between CXCL8 gene polymorphisms and the risk of cancer. However, the statistical power of many of these reports was limited, yielding ambiguous or conflicting results in many cases. METHODS: Accordingly, the PubMed, Wanfang, Scopus and Web of Science databases were searched for articles published until July 20, 2023 using the keywords 'IL-8' or 'interleukin-8' or 'CXCL8', 'polymorphism' and 'cancer' or 'tumor'. Odds ratios (ORs) and 95% confidence intervals (CIs) were utilized to examine the association. The CXCL8 +781 polymorphism genotypes were assessed with a TaqMan assay. RESULTS: About 29 related publications was conducted in an effort to better understand the association between these polymorphisms and disease risk. The CXCL8 -353A/T polymorphism was associated with an increased overall cancer risk [A vs. T, odds ratio (OR) = 1.255, 95% confidence interval (CI) (1.079-1.459), Pheterogeneity = 0.449, P = 0.003]. The CXCL8 +781 T/C allele was similarly associated with a higher risk of cancer among Caucasians [TT vs. TC + CC, OR = 1.320, 95%CI (1.046-1.666), Pheterogeneity = 0.375, P = 0.019]. Furthermore, oral cancer patients carrying the CXCL8 +781 TT + TC genotypes exhibited pronounced increases in serum levels of CXCL8 as compared to the CC genotype (P < 0.01), and also shown similar trend as compared to genotype-matched normal controls (P < 0.01). Finally, several limitations, such as the potential for publication bias or heterogeneity among the included studies should be paid attention. CONCLUSION: Current study suggested that the CXCL8 -353 and +781 polymorphisms may be associated with a greater risk of cancer, which might impact cancer prevention, diagnosis, or treatment through the different expression of CXCL8. At the same time, the +781 polymorphism may further offer value as a biomarker that can aid in the early identification and prognostic evaluation of oral cancer.

Identification of a novel cuproptosis-related gene signature for rheumatoid arthritis-A prospective study.

BACKGROUND: Rheumatoid arthritis (RA) is a multifactorial systemic autoimmune disease characterized by ongoing synovial inflammation, leading to the degradation of cartilage. Cuproptosis, as a newly characterized form of cell death, may influence RA progression by regulating immune cells and chondrocytes. This study sets out to identify the hub cuproptosis-related gene (CRG) associated with the pathogenesis of RA. METHODS: A series of bioinformatic analyses were performed to evaluate the expression score of CRGs and the immune infiltration landscape between RA and normal samples. The hub gene was screened through the correlation analysis of CRGs, and the interaction network between the hub gene and transcription factors (TFs) was constructed. Finally, the hub gene was validated through quantitative real-time polymerase chain reaction (qRT-PCR) of patient samples and cell experiments. RESULTS: Drolipoamide S-acetyltransferase (DLAT) was screened as the hub gene. Correlation analysis between the hub gene and immune microenvironment demonstrated that DLAT had the highest correlation with T follicular helper cells. Eight pairs of DLAT-TF interaction networks were constructed. Single-cell sequencing showed that CRGs were highly expressed in RA chondrocytes, and chondrocytes could be classified into three different subsets. qRT-PCR was used to validate the above results. Dlat knockdown in immortalized human chondrocytes led to significantly improved mitochondrial membrane potentials and reduced levels of intracellular reactive oxygen species (ROS), mitochondrial ROS and apoptosis. CONCLUSIONS: This study rudimentarily demonstrates the correlation between CRGs and immune cell infiltration in RA. The biomarker DLAT may provide comprehensive insights into the pathogenesis and drug targets of RA.

Kynurenic acid blunts A1 astrocyte activation against neurodegeneration in HIV-associated neurocognitive disorders.

Despite extensive astrocyte activation in patients suffering from HIV-associated neurocognitive disorders (HAND), little is known about the contribution of astrocytes to HAND neuropathology. Here, we report that the robust activation of neurotoxic astrocytes (A1 astrocytes) in the CNS promotes neuron damage and cognitive deficits in HIV-1 gp120 transgenic mice. Notably, knockout of α7 nicotinic acetylcholine receptors (α7nAChR) blunted A1 astrocyte responses, ultimately facilitating neuronal and cognitive improvement in the gp120tg mice. Furthermore, we provide evidence that Kynurenic acid (KYNA), a tryptophan metabolite with α7nAChR inhibitory properties, attenuates gp120-induced A1 astrocyte formation through the blockade of α7nAChR/JAK2/STAT3 signaling activation. Meanwhile, compared with gp120tg mice, mice fed with tryptophan showed dramatic improvement in cognitive performance, which was related to the inhibition of A1 astrocyte responses. These initial and determinant findings mark a turning point in our understanding of the role of α7nAChR in gp120-mediated A1 astrocyte activation, opening up new opportunities to control neurotoxic astrocyte generation through KYNA and tryptophan administration.

Overexpression of Taetr1-1 promotes enhanced seed dormancy and ethylene insensitivity in wheat.

MAIN CONCLUSION: Taetr1-1 can promote enhanced seed dormancy and ethylene insensitivity in wheat, indicating a conserved function of ETR1 in regulating seed dormancy. Lots of wheat cultivars have weak dormant seed. Weak seed dormancy can cause pre-harvest sprouting (PHS) in grain which significantly reduces grain yield and quality. The mining of causal genes of PHS resistance will serve to enhance breeding selection and cultivar development. In a previous study in Arabidopsis, we identified reduced dormancy 3 as a loss-of-function mutant of the ethylene receptor 1 (ETR1), which can control seed dormancy through the ERF12-TPL-DOG1 pathway. However, it is unknown whether ETR1 also functions in the regulation of wheat seed dormancy. To identify the regulatory role of ETR1 in wheat, we cloned TaETR1 and overexpressed the gain-of-function mutant Taetr1-1. The result indicated that overexpression of Taetr1-1 can promote enhanced seed dormancy and ethylene insensitivity in wheat. This study contributed to our understanding of the molecular basis for the regulation of wheat PHS resistance.