Molecular Genetics and Genomics最新文献

Pro-differentiation and anti-senescence treatment may be potential strategies for senile osteoporosis therapy. However, the regulatory mechanism underlying osteoblast differentiation and senescence in senile osteoporosis remain to be clarified. In the present study, the preosteoblast cell line MC3T3-E1 was used to induce osteoblast differentiation. The H₂O₂ was applied to induce senescence. H₂O₂ treatment significantly inhibited the expression of Wilms tumor 1-associating protein (WTAP), runtrelated transcription factor 2 (Runx2), Osterix and specific protein 1 (Sp1), inhibited the alkaline phosphatase (ALP) activity, upregulated the senescence-associated β-galactosidase (SA-β-Gal), and increased the mRNA levels of p16 and p21. WTAP overexpression significantly reversed the effect of H₂O₂, during the osteoblast differentiation of MC3T3-E1 cells. The RIP-qRT-PCR and MeRIP-qRT-PCR assays confirmed that N6-methyladenosine (m⁶A) modification of Sp1 mRNA was significantly decreased by H₂O₂ treatment, but was increased by WTAP overexpression. The m⁶A modification of Sp1 mRNA significantly increased the stability of Sp1 mRNA. The ChIP-qRT-PCR assay and luciferase reporter gene assay showed that Sp1 could bind to the promoter of BMP2. BMP2 knockdown reversed the effect of Sp1 on osteoblast differentiation and senescence. In conclusion, WTAP increased BMP2 expression to promote osteoblast differentiation and inhibit osteoblast senescence via increasing m⁶A methylation of Sp1 mRNA. This study sheds new light on our understanding of mechanisms underlying osteoblast differentiation and senescence, and provides potential strategies for senile osteoporosis therapy.

Pseudomonas fluorescens is commonly found in diverse environments and is well known for its metabolic and antagonistic properties. Despite its remarkable attributes, its potential role in promoting plant growth remains unexplored. This study examines these traits across 14 strains residing in diverse rhizosphere environments through pangenome and comparative genome analysis, alongside molecular docking studies against Erwinia amylovora to combat fire blight. Whole genome analysis revealed circular chromosome (6.01-7.07 Mb) with GC content averaging 59.95-63.39%. Predicted genes included 16S rRNA and protein-coding genes ranging from 4435 to 6393 bp and 1527 to 1541 bp, respectively. Pangenome analysis unveiled an open pangenome, shedding light on genetic factors influencing plant growth promotion and biocontrol, including nitrogen fixation, phosphorus solubilization, siderophore production, stress tolerance, flagella biosynthesis, and induced systemic resistance. Furthermore, pyrrolnitrin, phenazine-1-carboxylic acid, pyoluteorin, lokisin, 2,4-diacetylpholoroglucinol and pseudomonic acid were identified. Molecular docking against key proteins of E. amylovora highlighted the high binding affinities of 2,4-diacetylphloroglucinol, pseudomonic acid, and lokisin. These findings underscore the multifaceted role of P. fluorescens in plant growth promotion and biocontrol, with key biomolecules showing promising applications in plant growth and defense against pathogens.

Colorectal cancer (CRC) is a malignant tumor with poor prognosis and adverse therapeutic effect. The study aims to elucidate the contribution of OGT-mediated glycosylation of ADAR to chemoresistance in CRC through its role and regulatory mechanisms. Variations in OGT expression levels and their impact on CRC cell chemoresistance were investigated using gain-of-function and loss-of-function assays. Through a series of molecular biology experiments, we confirmed that ADAR is the downstream target of OGT regulation, emphasizing the role of OGT-mediated glycosylation in stabilizing ADAR. Furthermore, RNA immunoprecipitation (RIP) assays were conducted to examine the effects of ADAR-mediated A-to-I editing on the mRNA stability and translation of genes associated with DNA damage repair. Elevated OGT expression was found to enhance CRC's malignancy and resistance to chemotherapy. OGT's influence leads to the glycosylation of ADAR, thereby increasing its protein levels. ADAR, through its role in A-to-I editing, modulates the mRNA editing of genes implicated in DNA damage repair. This regulation enhances the expression of these genes, improves DNA repair capabilities, and ultimately, fosters chemoresistance in CRC cells. In conclusion, ADAR promotes PARP1 expression under the positive regulation of OGT-mediated O-glycosylation modification to enhance drug resistance in COAD cells. It provides the research basis for overcoming the drug resistance of CRC.

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition and ranks as the fourth leading cause of mortality worldwide. Despite extensive research efforts, a reliable diagnostic or prognostic tool for COPD remains elusive. The identification of novel biomarkers may facilitate improved therapeutic strategies for patients suffering from this debilitating disease. MicroRNAs (miRNAs), which are small non-coding RNA molecules, have emerged as promising candidates for the prediction and diagnosis of COPD. Studies have demonstrated that dysregulation of miRNAs influences critical cellular and molecular pathways, including Notch, Wnt, hypoxia-inducible factor-1α, transforming growth factor, Kras, and Smad, which may contribute to the pathogenesis of COPD. Extracellular vesicles, particularly exosomes, merit further investigation due to their capacity to transport various biomolecules such as mRNAs, miRNAs, and proteins between cells. This intercellular communication can significantly impact the progression and severity of COPD by modulating signaling pathways in recipient cells. A deeper exploration of circulating miRNAs and the content of extracellular vesicles may lead to the discovery of novel diagnostic and prognostic biomarkers, ultimately enhancing the management of COPD. The current review focus on the pathogenic role of miRNAs and their exosomal counterparts in chest and respiratory diseases, centering COPD.

With the advent of advanced sequencing technologies, new insights into the genomes of pathogens, including those in the genus Curtobacterium, have emerged. This research investigates a newly isolated C. flaccumfaciens strain 208 (Cf208) from Arthrocereus glaziovii, and endemic plant from Iron Quadrangle. Previous results show that Cf208 exhibits the potential to remediate soils, facilitating the growth of tomato plants. Furthermore, Cf208 showed no virulence towards bean plants, thus, confounding its phytopathogenic origins. Using a comprehensive comparative genomics approach, we analyzed the Cf208 genome against 34 other Curtobacterium strains, aiming to discern the genomic landmarks associated with its adaptation as an endophyte and its avirulence in bean crops. This revealed a predominant core genome comprising about 2426 genes (68%). Notably, Cf208 possesses a unique plasmid, pCF208-73, which contains 84 unique genes (2.5%). However, unlike the plasmids previously described for pathogenic strains, pCF208-73 does not feature genes associated with virulence induction. In contrast, while several genes traditionally linked to virulence, like pectate lyases and proteases were identified, but the T4P apparatus emerged as new crucial factor for understanding virulence in the Curtobacterium genus. The presence or absence of this apparatus, especially in strains from different clades, may determine their virulence towards leguminous plants. In conclusion, this work highlights the significance of comparative genomics in unraveling the complexities of pathogenicity within the Curtobacterium genus. Our findings suggest that, although the limited genetic variations, specific genes, particularly those linked to the T4P apparatus, play a fundamental role in their interactions with host plants.

Citrus huanglongbing (HLB) is a major challenge that impacts the flourishing of the citrus industry. Therefore, analyzing the genomic information of HLB-resistant or tolerant citrus resources is crucial for breeding HLB-resistant citrus varieties. The Carrizo citrange, a hybrid of Citrus sinensis and Poncirus trifoliata, plays a pivotal role in citrus cultivation. However, its genetic explorations are difficult due to the absence of a reference genome or full-length transcriptome. In order to enhance our understanding of the genetic information of citrange, we conducted a full-length transcriptomic sequencing of multiple tissues from the Carrizo citrange using the PacBio Sequel II platform. Moreover, we performed gene ontology (GO) annotation, gene functional annotation, simple sequence repeats (SSR) types analysis, as well as identification of lncRNAs, alternative splicing events, and analysis of pathogen defense-related genes. Results showed that a total of 43,452 isoforms were generated, with 43,307 of them being annotated. GO annotation indicated the involvement of these isoforms in various biological processes, cellular components, and molecular functions. The coding sequence length of the isoforms ranged from 1,000 to 4,000 base pairs (bp). Moreover, we have discovered 54 varieties of transcription factors and regulators, along with 16 classifications of genes associated with resistance. Among all types of SSRs, trimer type SSRs were the most abundant. 130 lncRNAs were predicted to be highly reliable in the isoforms of the Carrizo citrange, with alternative splicing events identified, and the most frequent being retained intron. The analysis of gene family expansion and contraction revealed a significant increase in pathogen defense-related genes within the Carrizo citrange. The results of this study will be of great value for future investigations into gene function in citrange and for expanding the genetic pool for breeding citrus varieties resistant or tolerant to HLB.

Heterogeneous behavior of each cell type and their cross-talks in tumor immune microenvironment (TIME) refers to tumor immunological heterogeneity that emerges during tumor progression and represents formidable challenges for effective anti-tumor immune response and promotes drug resistance. To comprehensively elucidate the heterogeneous behavior of individual cell types and their interactions across different stages of tumor development at system level, a computational framework was devised that integrates cell specific data from single-cell RNASeq into networks illustrating interactions among signaling and metabolic response genes within and between cells in TIME. This study identified stage specific novel markers which remodel the cross-talks, thereby facilitating immune stimulation. Particularly, multicellular knockout of metabolic gene APOE (Apolipoprotein E in mast cell, myeloid cell and fibroblast) combined with signaling gene CAV1 (Caveolin1 in endothelial and epithelial cells) resulted in the activation of T-cell mediated signaling pathways. Additionally, this knockout also initiated intervention of cytotoxic gene regulations during tumor immune cell interactions at the early stage of Lung Adenocarcinoma (LUAD). Furthermore, a unique interaction motif from multiple cells emerged significant in regulating the overall immune response at the advanced stage of LUAD. Most significantly, FCER1G (Fc Fragment of IgE Receptor Ig) was identified as the common regulator in activating the anti-tumor immune response at both stages. Predicted markers exhibited significant association with patient overall survival in patient specific dataset. This study uncovers the significance of signaling and metabolic interplay within TIME and discovers important targets to enhance anti-tumor immune response at each stage of tumor development.

Single nucleotide polymorphisms (SNPs) in homologous regions play a critical role in the field of genetics. However, genotyping these SNPs is challenging due to the presence of repetitive sequences within genome, which demand specific method. We introduce a new, mid-throughput method that simplifies SNP genotyping in homologous DNA sequences by utilizing a combination of multiplex kb level PCR (PCR size 2.5k-3.5 kb) for capturing targeted regions and multiplex nested PCR library construction for next-generation sequencing (Multi-kb level capture-seq). First of all, we randomly selected 7 SNPs in homologous regions and successfully captured 6-plex kb level amplicons (one of segments contains 2 SNPs, while the remaining segments each have only one SNP) in a single tube. And then, the amplification products were subjected to multiplex nested PCR for library construction and sequenced on Illumina platform. We tested this strategy using 600 amplicons from 100 samples and accurately genotyped 96.8% of target SNPs with a coverage depth of ≥ 15×. For the uniformity within the samples, over 66.7% (4/6) of the amplicons had a coverage depth above 0.2-fold of average sequencing depth. To validate the accuracy of this approach, we performed Ligase detection reaction PCR for genotyping the 100 samples, and found that the genotyping data was 97.71% consistent with our NGS results. In conclusion, we have developed a highly efficient and accurate method for SNP genotyping in homologous regions, which offers researchers a new strategy to explore the complex regions of genome.

Ethanol stress in Saccharomyces cerevisiae is a well-studied phenomenon, but pinpointing specific genes or polymorphisms governing ethanol tolerance remains a subject of ongoing debate. Naturally found in sugar-rich environments, this yeast has evolved to withstand high ethanol concentrations, primarily produced during fermentation in the presence of suitable oxygen or sugar levels. Originally a defense mechanism against competing microorganisms, yeast-produced ethanol is now a cornerstone of brewing and bioethanol industries, where customized yeasts require high ethanol resistance for economic viability. However, yeast strains exhibit varying degrees of ethanol tolerance, ranging from 8 to 20%, making the genetic architecture of this trait complex and challenging to decipher. In this study, we introduce a novel QTL mapping pipeline to investigate the genetic markers underlying ethanol tolerance in an industrial bioethanol S. cerevisiae strain. By calculating missense mutation frequency in an allele located in a prominent QTL region within a population of 1011 S. cerevisiae strains, we uncovered rare occurrences in gene IRA2. Following molecular validation, we confirmed the significant contribution of this gene to ethanol tolerance, particularly in concentrations exceeding 12% of ethanol. IRA2 pivotal role in stress tolerance due to its participation in the Ras-cAMP pathway was further supported by its involvement in other tolerance responses, including thermotolerance, low pH tolerance, and resistance to acetic acid. Understanding the genetic basis of ethanol stress in S. cerevisiae holds promise for developing robust yeast strains tailored for industrial applications.