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Research progress on the regulatory mechanisms of the PSY promoter.

Carotenoids are essential pigments in the plant photosynthetic apparatus, functioning in light harvesting, photoprotection, and signal transduction, and serving as precursors of vital nutrients such as vitamin A. Phytoene synthase (PSY) is the first rate-limiting enzyme in the plant carotenoid biosynthetic pathway, and its transcriptional regulation primarily depends on cis-acting promoter elements, associated transcription factors, and epigenetic status. The PSY promoter region contains core cis-elements as well as multiple light-, hormone-, and stress-responsive elements, which collectively function as key regulatory sites governing spatiotemporal expression. This review systematically summarizes recent advances in PSY promoter regulation by plant hormones (e.g., abscisic acid, ethylene, jasmonic acid), environmental factors (light signaling, temperature, salinity, and drought), and epigenetic mechanisms (DNA methylation, histone modifications, and chromatin remodeling). In addition, the application of transgenic and biotechnological approaches to PSY promoter regulation is further summarized. Including promoter sequence engineering with precise editing of cis-elements and promoter-targeted CRISPR activation/interference (CRISPRa/i) for tunable transcriptional control. Emphasis is placed on how these signals are integrated at the promoter level. Deeper insights into these mechanisms will provide both theoretical foundations and practical strategies for enhancing carotenoid accumulation and stress tolerance in crops through molecular design.

Promoter Regions, Genetic

Bimodal retrograde signaling disrupts a suppressor network and activates a key transcriptional activator to direct stress responses.

Plastid-to-nucleus communication, crucial for regulating stress-responsive gene expression, has long intrigued researchers. This study reveals how the plastidial metabolite 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEcPP) orchestrates transcriptional reprogramming by modulating the rapid stress response element (RSRE), a conserved regulatory hub in the plant general stress response network. Yeast one-hybrid assays identified HAT1, a class II HD-Zip protein, as a negative regulator of RSRE. Genetic analyses, including HAT1 overexpression and knockdowns, confirmed its role in suppressing RSRE activity. Interaction assays uncovered a suppression network involving HAT1, the co-repressor TOPLESS (TPL), and the nuclear importin IMPα-9. Furthermore, HAT1 interacts with calmodulin-binding transcription activator 3 (CAMTA3), a calcium/calmodulin-binding transcription factor known to activate RSRE. AlphaFold modeling provided insights into the architecture of the HAT1-RSRE complex and HAT-CAMTA3 interaction, supported by conserved domains across plant species. Under stress condition, MEcPP accumulation promotes the 26S proteasomal degradation of TPL and IMPα-9 while reduces auxin-dependent HAT1 expression. Additionally, MEcPP enhances Ca2+ influx, activating CAMTA3 and enabling it to bind RSRE, thereby initiating the transcription of stress response genes. This dual mechanism-dismantling suppressors (HAT1, TPL, and IMPα-9) and activating CAMTA3-underscores MEcPP's central role in plastid-to-nucleus signaling. These findings emphasize MEcPP's pivotal function in dynamically regulating gene expression to maintain cellular homeostasis under environmental stress.

Arabidopsis Proteins

Comparative analysis of DREB gene family in buckwheat: the role of FtDREB02 in the delphinidin biosynthesis and drought stress response.

Dehydration response element binding (DREB) transcription factors play a pivotal role in plant abiotic stress responses, but its evolutionary and functional characterization in buckwheat remains unexplored. Here, we conducted a comprehensive analysis of the DREB gene family across three buckwheat species, revealing segmental duplication as the primary driver of family expansion and potential purifying selection during evolution. A FtDREB02 gene, classified as group A2, was identified through genome-wide association analysis (GWAS) on drought tolerance and delphinidin content. Functional validation in Arabidopsis thaliana and the hairy root of Tartary buckwheat (Fagopyrum tataricum) demonstrated that overexpression of this gene promotes delphinidin biosynthesis and enhances plant resistance to water scarcity. Through the integration of DAP-seq and PEG transcriptome cluster analysis, a FtANS candidate was screened. Functional studies showed that FtDREB02 regulates delphinidin content by binding directly to DRE elements of the FtANS promoter. This research identifies and comprehensively analyzes the DREB family within buckwheat species, elucidating the regulatory mechanisms of FtDREB02 in controlling flavonoid biosynthesis and drought resistance, providing potential genetic resources for breeding buckwheat varieties with excellent agronomic traits.

Anthocyanins

Ternary complex factor-serum response factor complex-regulated gene activity is required for cellular proliferation and inhibition of apoptotic cell death.

Members of the ternary complex factor (TCF) subfamily of the ETS-domain transcription factors are activated through phosphorylation by mitogen-activated protein kinases (MAPKs) in response to a variety of mitogenic and stress stimuli. The TCFs bind and activate serum response elements (SREs) in the promoters of target genes in a ternary complex with a second transcription factor, serum response factor (SRF). The association of TCFs with SREs within immediate-early gene promoters is suggestive of a role for the ternary TCF-SRF complex in promoting cell cycle entry and proliferation in response to mitogenic signaling. Here we have investigated the downstream gene regulatory and phenotypic effects of inhibiting the activity of genes regulated by TCFs by expressing a dominantly acting repressive form of the TCF, Elk-1. Inhibition of ternary complex activity leads to the downregulation of several immediate-early genes. Furthermore, blocking TCF-mediated gene expression leads to growth arrest and triggers apoptosis. By using mutant Elk-1 alleles, we demonstrated that these effects are via an SRF-dependent mechanism. The antiapoptotic gene Mcl-1 is identified as a key target for the TCF-SRF complex in this system. Thus, our data confirm a role for TCF-SRF-regulated gene activity in regulating proliferation and provide further evidence to indicate a role in protecting cells from apoptotic cell death.

Alleles

In vitro fertilization-conceived offspring exhibit altered Long Interspersed Nuclear Elements-1 retrotransposition dynamics associated with long-term disease risks.

BACKGROUND: In vitro fertilization has transformed reproductive medicine, yet offspring conceived through in vitro fertilization display elevated risks for diverse long-term health conditions, with underlying mechanisms unclear. Long Interspersed Nuclear Elements-1, a mobile genetic element responsive to environmental stress, represents a potential mediator. OBJECTIVE: This study aimed to test the hypothesis that in vitro fertilization procedures may act as an embryonic stressor that alters Long Interspersed Nuclear Elements-1 dynamics, potentially contributing to genomic instability associated with long-term disease susceptibility. STUDY DESIGN: Umbilical cord blood or peripheral blood from 33 in vitro fertilization and 42 naturally conceived neonates were collected for whole-genome sequencing. Total Long Interspersed Nuclear Elements-1 proportion in individual genome was counted with Bowtie2 software. De novo Long Interspersed Nuclear Elements-1 insertion and Long Interspersed Nuclear Elements-1 deletion were detected with Mobile Element Locator Tool. Three parent-matched in vitro fertilization-naturally conceived sibling pairs were included to control for genetic background. Disease association analysis was performed for genes within 500 kb of differential Long Interspersed Nuclear Elements-1 sites in The Database for Annotation, Visualization and Integrated Discovery (DAVID). Statistical analysis was performed using the R language. RESULTS: In vitro fertilization offspring demonstrate elevated global Long Interspersed Nuclear Elements-1 content compared to naturally conceived controls (P=.04). This finding was corroborated in 3 sibling pairs from identical genetic backgrounds, where in vitro fertilization-conceived children consistently exhibited higher Long Interspersed Nuclear Elements-1 levels than their naturally conceived siblings. Eleven genomic loci with differential Long Interspersed Nuclear Elements-1 insertion frequencies and 14 loci with differential Long Interspersed Nuclear Elements-1 deletion frequencies between in vitro fertilization offspring and naturally conceived controls were identified. Notably, these differential Long Interspersed Nuclear Elements-1 sites demonstrated significant enrichment near genes implicated in metabolic, cardiovascular, neuropsychiatric, and neoplastic diseases, conditions associated with in vitro fertilization conception. CONCLUSION: These findings provide preliminary evidence that in vitro fertilization conception is associated with increased Long Interspersed Nuclear Elements-1 content and altered genomic distribution of Long Interspersed Nuclear Elements-1 elements. The proximity of these differential Long Interspersed Nuclear Elements-1 sites to disease-associated genes suggests a plausible genomic mechanism linking in vitro fertilization-associated embryonic stress to elevated disease risk. This work provides valuable molecular insights that may inform the ongoing discussion about assisted reproductive technology safety and suggests that continued attention to genomic integrity in in vitro fertilization-conceived individuals would be beneficial.

Humans

NAD activates olfactory receptor 1386 to regulate type I interferon responses in Plasmodium yoelii YM infection.

Olfactory receptors (Olfr) are G protein-coupled receptors that are normally expressed on olfactory sensory neurons to detect volatile chemicals or odorants. Interestingly, many Olfrs are also expressed in diverse tissues and function in cell-cell recognition, migration, and proliferation as well as immune responses and disease processes. Here, we showed that many Olfr genes were expressed in the mouse spleen, linked to Plasmodium yoelii genetic loci significantly, and/or had genome-wide patterns of LOD scores (GPLSs) similar to those of host Toll-like receptor genes. Expression of specific Olfr genes such as Olfr1386 in HEK293T cells significantly increased luciferase signals driven by IFN-β and NF-κB promoters, with elevated levels of phosphorylated TBK1, IRF3, P38, and JNK. Mice without Olfr1386 were generated using the CRISPR/Cas9 method, and the Olfr1386-/- mice showed significantly lower IFN-α/β levels and longer survival than wild-type (WT) littermates after infection with P. yoelii YM parasites. Inhibition of G protein signaling and P38 activity could affect cyclic AMP-responsive element promoter-driven luciferase signals and IFN-β mRNA levels in HEK293T cells expressing the Olfr1386 gene, respectively. Screening of malaria parasite metabolites identified nicotinamide adenine dinucleotide (NAD) as a potential ligand for Olfr1386, and NAD could stimulate IFN-β responses and phosphorylation of TBK1 and STAT1/2 in RAW264.7 cells. Additionally, parasite RNA (pRNA) could significantly increase Olfr1386 mRNA levels. This study links multiple Olfrs to host immune response pathways, identifies a candidate ligand for Olfr1386, and demonstrates the important roles of Olfr1386 in regulating type I interferon (IFN-I) responses during malaria parasite infections.

Animals

Identification of rice DUF1719 gene family and analysis of alkaline tolerance function of OsDUF1719.8.

Alkaline stress severely constrains the physiological metabolism and growth and development of rice through high pH and ionic toxicity. Domains of unknown function (DUF) play significant roles in plant stress responses. However, the function of the DUF1719 family (PF08224) in rice has not been reported and further research is needed. This study systematically identified the OsDUF1719 gene family in rice and investigated the function of OsDUF1719.8 under alkaline stress. The results demonstrate that the rice DUF1719 family comprises 13 protein members, all containing the PF08224 domain. It is predicted that this domain may play a role in ATPase activation. Evolutionary analysis divided DUF1719 proteins from eight grass species into six subgroups, with highly conserved gene structures, motifs, and tertiary architectures within each subgroup. Promoter analysis indicated enrichment of stress- and hormone-responsive elements, implying broad involvement in stress regulation. Expression analysis revealed that several genes, including OsDUF1719.5 and OsDUF1719.8, were upregulated under multiple abiotic stresses. Notably, OsDUF1719.8 was strongly induced during early alkaline stress. Consequently, we further analyzed the function of OsDUF1719.8 in the rice alkaline stress response. The results demonstrate that overexpression of OsDUF1719.8 enhanced rice alkaline tolerance, whereas knockout mutants exhibited stress sensitivity. OsDUF1719.8 enhances rice tolerance to alkaline stress by coordinately regulating reactive oxygen species metabolism, promoting the accumulation of osmotic adjustment compounds, and modulating ion homeostasis. This study provides the first systematic identification of the DUF1719 family and elucidates the function of OsDUF1719.8 in positively regulating rice alkaline tolerance, offering a novel gene for alkali-tolerant molecular breeding of rice.

Oryza

Functional genomic analysis of non-canonical DNA regulatory elements of the aryl hydrocarbon receptor.

The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor activated by environmental toxicants like halogenated and polycyclic aromatic hydrocarbons, which then binds to DNA and regulates gene expression. AHR is implicated in numerous physiological processes, including liver and immune function, cell cycle control, oncogenesis, and metabolism. Traditionally, AHR binds a consensus DNA sequence (GCGTG), the xenobiotic response element (XRE), recruits coregulators, and modulates gene expression. Yet, recent evidence suggests AHR can also regulate gene expression via a non-consensus sequence (GGGA), termed the non-consensus XRE (NC-XRE). The prevalence and functional significance of NC-XRE motifs in the genome have remained unclear. While ChIP and reporter studies hinted at AHR-NC-XRE interactions, direct evidence for transcriptional regulation in a native context was lacking. In this study, we analyzed AHR binding to NC-XRE sequences genome-wide in mouse liver, integrating ChIP-seq and RNA-seq data to identify candidate AHR target genes containing NC-XRE motifs in their regulatory regions. We found NC-XRE motifs in 82% of AHR-bound DNA, significantly enriched compared to random regions, and present in promoters and enhancers of AHR targets. Functional genomics on the Serpine1 gene revealed that deleting NC-XRE motifs reduced TCDD-induced Serpine1 upregulation, demonstrating direct regulation. These findings provide the first direct evidence for AHR-mediated regulation via NC-XRE in a natural genomic context, advancing our understanding of AHR-bound DNA and its impact on gene expression and physiological relevance.

Journal Article

Transcriptional Mapping of the Human Cannabinoid Receptor 1 (CNR1) Gene Promoter.

The transcriptional regulation of the cannabinoid receptor 1 (CB1R) by promoter/enhancer elements and transcription factors is an area of cannabinoid research that has historically been understudied. To map the promoter region of the human CNR1 gene (the gene encoding CB1R), a 997-base-pair fragment from the sequence upstream of the CNR1 gene was cloned into a secreted luciferase reporter vector, and a series of deletion fragments were constructed. The transcriptional activity of these constructs was tested in human cell lines from three tissues: neuronal tissue (SHSY5Y), kidney tissue (HEK293T), and colonic epithelium (HCT116). Through this mapping, we have identified two key regulatory regions within the promoter. Increased levels of cAMP suppressed reporter expression from the full-length promoter fragment in all three cell lines, and in silico modeling predicts potential cAMP response elements (CRE) within one of the key regulatory sequences. Additionally, the minimal promoter region for CNR1 also appears to be in the second regulatory region identified, and in silico modeling predicts BRE and INR elements within this sequence. These findings begin to unravel the mechanisms by which CNR1 is transcriptionally regulated.

Humans

Genome-wide identification of the Glutathione Peroxidase (GPX) gene family in Taxodium distichum and functional characterization of TdGPX9 in enhancing salt tolerance.

This study systematically identified 10 TdGPX genes in Taxodium distichum, demonstrating that the nucleocytoplasmic-localized TdGPX9 plays a pivotal role in salt stress response. Overexpression of TdGPX9 significantly enhances salt tolerance by strengthening the antioxidant defense system and improving root system plasticity under stress. Taxodium distichum is a premier coniferous species renowned for its exceptional waterlogging and salinity tolerance, serving as a vital forest resource for coastal afforestation and wetland ecological restoration. Within the physiological framework of plant stress resistance, the glutathione peroxidase (GPX) family represents a cornerstone of the antioxidant enzymatic system, playing a critical role in scavenging reactive oxygen species and maintaining cellular redox homeostasis. In this study, 10 TdGPX genes were identified via a comprehensive genome-wide analysis and mapped across eight chromosomes. These genes possess a highly conserved Thioredoxin_like domain, with structural and motif analyses revealing a well-maintained arrangement of conserved motifs within each subgroup. The promoter analysis identified a sophisticated regulatory network enriched with cis-acting elements responsive to light, phytohormones, and abiotic stresses, suggesting their integration into diverse signaling pathways. Expression profiling across various tissues and embryonic developmental stages further highlighted the versatile roles of TdGPX members in plant growth and organogenesis. Notably, qRT-PCR analysis identified the nucleocytoplasmic-localized TdGPX9 as a primary respondent to salinity. Functional validation demonstrated that TdGPX9 overexpression significantly enhances salt tolerance in transgenic Arabidopsis and T. distichum callus by strengthening the antioxidant defense system. Furthermore, TdGPX9 promoted root system plasticity under stress, as evidenced by increased lateral root density. These findings provide a systematic basis for understanding the redox-regulatory mechanisms in baldcypress and offer vital genetic resources for improving forest resilience in coastal wetland ecosystems.

Salt Tolerance

Identification of essential genes for conjugative transfer in antimicrobial resistance-associated pELF-type linear plasmids of opportunistic pathogen Enterococcus faecium.

The pELF-type linear plasmid is a critical mobile genetic element responsible for the dissemination of various antimicrobial resistance (AMR) genes, most notably vancomycin resistance in Enterococcus faecium, which is a leading cause of hospital outbreaks worldwide. Despite their crucial role in the expansion of AMR, the molecular mechanisms underlying the conjugative transfer of these linear plasmids remain poorly understood. In this study, the transfer (tra) region of pELF2, a representative vanA-harboring linear plasmid was characterized. Transcriptomic data suggested that the FtsK/VirD4-type adenosine triphosphatase is encoded within a multi-gene operon. By developing a genetic manipulation framework for E. faecium, an extensive mutational analysis of the tra region was performed and the following three essential genes were identified: traCB4 (a putative VirB4 analog), traDD4 (a VirD4-like coupling protein), and traGB6 (a putative VirB6 analog). These genes are indispensable for conjugative transfer. Reporter assays experimentally confirmed the presence of a functional promoter upstream of the identified tra genes. We confirmed that these genes are highly conserved among pELF-type plasmid sequences deposited in public database. The study findings revealed that pELF-type plasmids utilize highly minimized conjugation machinery, which is similar to unusual systems previously identified in other gram-positive bacteria, such as Streptomyces. This study provides the first molecular insights into the transmission of these clinically important linear plasmids in enterococci and lays a foundation for understanding the dissemination of resistance determinants mediated by atypical mobile genetic elements.

Enterococcus faecium

Development and Characterization of an Inducible Bacterial Artificial Chromosome System for Studying Lytic Replication and Pathogenesis of Kaposi's Sarcoma-Associated Herpesvirus.

Bacterial artificial chromosome (BAC) is widely used to manipulate herpesvirus genome and generate recombinant virus. Here, we developed a new KSHV BACmid, namely as iBAC, by replacing the EGFP with TET3G transactivator under EF1α promoter and inserted Tet response elements in the promoter of RTA in the original KSHV BAC16 clone and characterized KSHV lytic replication in SLK-iBAC cells. SLK-iBAC cells developed more efficient lytic replication and generated more progeny virus than iSLK-BAC16 cells upon the same conditions of doxycycline treatment. Since SLK-iBAC cells only occupied hygromycin selection marker, it is convenient to generate cellular gene knockout via lentivirus-mediated CRISPR-Cas9 or stably express viral or cellular gene via lentivirus followed by antibiotic selection, making iBAC system a better tool to identify cellular targets of viral proteins in the context of virus infection or study the role of viral or cellular genes for KSHV lytic replication and pathogenesis. In addition, iBAC is color-free and can be utilized to track subcellular localization of viral proteins or colocalization between different viral proteins by introducing fusing fluorescent proteins into the BAC backbone. Therefore, the new KSHV iBAC is a powerful inducible tool to study KSHV lytic replication and pathogenesis in cell model.

Chromosomes, Artificial, Bacterial

Discovery of the Underlying Mechanism of Ginger Juice Processed Ziziphi Spinosae Semen for Its Sedative-Hypnotic Effect on Insomnia Mice via Regulation of HPA Axis and cAMP/PKA Signaling Pathway.

Based on Traditional Chinese Medicine (TCM) theory, the efficacy and mechanism of Ginger juice processed Ziziphi Spinosae Semen (GJPZSS) for treating insomnia, particularly stress-related types, were investigated to provide empirical evidence. An insomnia model was induced in mice by DL-4-chlorophenylalanine (PCPA) and chronic tail clamping. The sedative effect was evaluated by behavioral tests. Serum components from GJPZSS were analyzed by UHPLC-Q-TOF-MS/MS, and 64 potential targets were identified. The cAMP signaling pathway was enriched as the core pathway by Kyoto Encyclopedia of genes and genomes (KEGG) analysis and was validated by molecular docking. GJPZSS was demonstrated to prolong sleep time, reduce immobility time, increase 5-hydroxytryptamine (5-HT) and gamma-aminobutyric acid (GABA) levels, decrease hypothalamic-pituitary-adrenal (HPA) axis levels, and suppress neuronal death. The reduction of the cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP-response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the brain was also significantly inhibited. It was concluded that the sleep-improving effect of GJPZSS was mediated through the regulation of the HPA axis and the cAMP/PKA/CREB/BDNF signaling pathway.

Animals

Thyroid Hormones and Co-workers: An Overview.

The hypothalamus secretes the thyroid-releasing hormone (TRH) that induces the pituitary gland to release the thyroid-stimulating hormone (TSH) which stimulates thyroid follicular cells to release the thyroid hormones (THs), thyroxine (T4), and triiodothyronine (T3). The process of synthesizing T3 and T4 hormones involves various enzymatic steps, starting with the iodination of L-tyrosine residues present in the protein thyroglobulin. Thyroid hormones are released into the bloodstream, where they bind to thyroid hormone distributor proteins (THDPs) which transport them in the circulation. The conversion of T4 to T3 (the more biologically active hormone) in target tissues is facilitated by selenoprotein enzymes known as deiodinases. THs can bind to different molecules located on the plasma membrane, such as integrin αvβ3, through which they exercise regulatory non-genomic control. Nevertheless, most of thyroid hormone's actions are mediated intracellularly by binding to thyroid hormone receptors (TRs). Thyroid hormone receptors act as ligand-dependent transcription factors, Thyroid hormone receptors activate thyroid hormone response elements on gene promoters through canonical signaling. Thyroid hormones mediate several critical physiological processes including organ development, cell differentiation, metabolism, and cell growth and maintenance.

Humans

TGA6 directly activates ABF2 and ABF3 to promote leaf senescence in Arabidopsis thaliana.

Leaf senescence is a tightly regulated developmental process governed by a complex transcriptional network. Although the TGACG motif-binding (TGA) family of basic leucine zipper (bZIP) transcription factors are well-characterized regulators of plant defense responses, their roles in leaf senescence remain poorly understood. Here, we report that overexpression of TGA6 in Arabidopsis thaliana promotes early leaf senescence. Independent TGA6-overexpressing lines displayed premature leaf yellowing and significantly lower chlorophyll levels than wild-type (WT) plants under both normal growth and dark-induced senescence conditions. At the molecular level, RT-qPCR analysis revealed significant upregulation of canonical senescence marker genes, including NYC1, PAO, SAG12, SAG13, SGR1, and SGR2, in the TGA6-OE lines relative to WT plants. Furthermore, we found that the transcript levels of ABA-responsive element binding factor 2 (ABF2) and ABF3, which act upstream of these senescence markers, were significantly elevated in the TGA6-OE lines. Dual-luciferase reporter assays and electrophoretic mobility shift assay demonstrated that TGA6 directly binds to the TGACG motifs within the promoters of ABF2 and ABF3 to activate their transcription. Collectively, these findings demonstrate that TGA6 functions as a positive regulator of leaf senescence.

Arabidopsis

CACNA1C Genetic Variants Differentially Affect Neuronal Networks Through Divergent Pathways.

BACKGROUND: CACNA1C encodes the pore-forming subunit of the L-type calcium channel Cav1.2. Common variants in CACNA1C are associated with psychiatric disorders, whereas rare single nucleotide variants cause CACNA1C-related disorder, a multisystem disorder with symptoms that include autism spectrum disorder (ASD), intellectual disability, and seizures. However, the cellular mechanisms linking CACNA1C dysfunction to neurodevelopmental phenotypes remain poorly understood. METHODS: We generated isogenic CACNA1C loss-of-function induced pluripotent stem cell lines and reprogrammed a line from an individual carrying a novel predicted gain-of-function variant (p.Ala1521Pro) in CACNA1C. Neuronal activity was assessed using multielectrode arrays, pharmacological manipulation, and gene expression analysis. Early developmental phenotypes were examined using quantitative reverse transcriptase polymerase chain reaction, immunocytochemistry, and RNA sequencing. RESULTS: Neurons carrying CACNA1C variants displayed opposing alterations in network dynamics, depending on variant type. Pharmacological and molecular assays indicated that these network differences were associated with dysregulated GABAergic (gamma-aminobutyric acidergic) signaling. Early developmental analysis revealed that loss of CACNA1C altered rosette morphology, CREB (cAMP response element binding protein) phosphorylation, and transcriptional programs related to axonogenesis and synaptic signaling, indicating effects on neuronal differentiation. The patient line exhibited opposing effects on rosette morphology and CREB signaling, reflecting variant-specific effects. CONCLUSIONS: These findings demonstrate that Cav1.2 regulates excitatory-inhibitory balance, network organization, and aspects of neurodevelopment. Divergent effects of CACNA1C variants highlight how altered Cav1.2 signaling contributes to variable neurodevelopmental phenotypes, including ASD and epilepsy, and establish a framework for defining CACNA1C variant effects in human neurons.

CACNA1C

Identification and functional characterization of a novel antiviral chicken interferon-υ.

Interferons are critical mediators of antiviral immunity in vertebrates. While type IV interferon (IFN-υ) has been identified in fish and amphibians, its existence and function in chickens remained unknown. Through systematic genomic screening, we identified and cloned a novel chicken interferon gene, designated ChIFN-υ. Phylogenetic analysis placed ChIFN-υ within a distinct clade alongside zebrafish and clawed frog IFN-υ, confirming its identity as a type IV interferon, with minimal homology to classical type I, II, or III IFNs. Expression profiling revealed constitutive ChIFN-υ expression in mucosal and immune tissues of healthy chickens, exhibiting a distinct developmental shift: highest in trachea and small intestine in 1-day-old chicks, shifting to spleen and lung in 4-week-old chickens. ChIFN-υ expression was strongly upregulated following H9N2 AIV infection. Functionally, recombinant ChIFN-υ protein activated the interferon-stimulated response element (ISRE) and Mx promoter in a dose-dependent manner and significantly inhibited the replication of both vesicular stomatitis virus (VSV) and H9N2 AIV in DF-1 cells. In vivo, early treatment with exogenous ChIFN-υ significantly reduced pulmonary and tracheal viral loads and decreased oropharyngeal and cloacal virus shedding in H9N2-infected chickens. In conclusion, this study identifies and functionally characterizes the type IV interferon in chickens, elucidating the evolutionary status, regulated expression, and antiviral efficacy of ChIFN-υ. These findings highlight its potential as a candidate for developing interferon-based therapies against avian viral diseases.

Animals

Nonsteroidal anti-inflammatory drugs repress beta-secretase gene promoter activity by the activation of PPARgamma.

Epidemiological evidence suggests that nonsteroidal anti-inflammatory drugs (NSAIDs) decrease the risk for Alzheimer's disease (AD). Certain NSAIDs can activate the peroxisome proliferator-activated receptor-gamma (PPARgamma), which is a nuclear transcriptional regulator. Here we show that PPARgamma depletion potentiates beta-secretase [beta-site amyloid precursor protein cleaving enzyme (BACE1)] mRNA levels by increasing BACE1 gene promoter activity. Conversely, overexpression of PPARgamma, as well as NSAIDs and PPARgamma activators, reduced BACE1 gene promoter activity. These results suggested that PPARgamma could be a repressor of BACE1. We then identified a PPARgamma responsive element (PPRE) in the BACE1 gene promoter. Mutagenesis of the PPRE abolished the binding of PPARgamma to the PPRE and increased BACE1 gene promoter activity. Furthermore, proinflammatory cytokines decreased PPARgamma gene transcription, and this effect was supressed by NSAIDs. We also demonstrate that in vivo treatment with PPARgamma agonists increased PPARgamma and reduced BACE1 mRNA and intracellular beta-amyloid levels. Interestingly, brain extracts from AD patients showed decreased PPARgamma expression and binding to PPRE in the BACE1 gene promoter. Our data strongly support a major role of PPARgamma in the modulation of amyloid-beta generation by inflammation and suggest that the protective mechanism of NSAIDs in AD involves activation of PPARgamma and decreased BACE1 gene transcription.

Aged