-
Journal of Cellular and Molecular... Jul 2024In recent years, inflammatory disorders have emerged as a significant concern for human health. Through ongoing research on anti-inflammatory agents, alpinetin has shown...
In recent years, inflammatory disorders have emerged as a significant concern for human health. Through ongoing research on anti-inflammatory agents, alpinetin has shown promising anti-inflammatory properties, including involvement in epigenetic modification pathways. As a crucial regulator of epigenetic modifications, Mecp2 may play a role in modulating the epigenetic effects of alpinetin, potentially impacting its anti-inflammatory properties. To test this hypothesis, two key components, p65 (a member of NF-KB family) and p300 (a type of co-activator), were screened by the expression profiling microarray, which exhibited a strong correlation with the intensity of LPS stimulation in mouse macrophages. Meanwhile, alpinetin demonstrates the anti-inflammatory properties through its ability to disrupt the synthesis of p65 and its interaction with promoters of inflammatory genes, yet it did not exhibit similar effects on p300. Additionally, Mecp2 can inhibit the binding of p300 by attaching to the methylated inflammatory gene promoter induced by alpinetin, leading to obstacles in promoter acetylation and subsequently impacting the binding of p65, ultimately enhancing the anti-inflammatory capabilities of alpinetin. Similarly, in a sepsis mouse model, it was observed that homozygotes overexpressing Mecp2 showed a greater reduction in organ damage and improved survival rates compared to heterozygotes when administered by alpinetin. However, blocking the expression of DNA methyltransferase 3A (DNMT3A) resulted in the loss of Mecp2's anti-inflammatory assistance. In conclusion, Mecp2 may augment the anti-inflammatory effects of alpinetin through epigenetic 'crosstalk', highlighting the potential efficacy of a combined therapeutic strategy involving Mecp2 and alpinetin for anti-inflammatory intervention.
Topics: Methyl-CpG-Binding Protein 2; Animals; Flavanones; Epigenesis, Genetic; Mice; Anti-Inflammatory Agents; Promoter Regions, Genetic; RAW 264.7 Cells; DNA Methylation; Lipopolysaccharides; Transcription Factor RelA; Sepsis; Macrophages; Inflammation; DNA Methyltransferase 3A; Male; E1A-Associated p300 Protein; Disease Models, Animal; Mice, Inbred C57BL; DNA (Cytosine-5-)-Methyltransferases
PubMed: 38953409
DOI: 10.1111/jcmm.18510 -
Frontiers in Microbiology 2024The unique dormancy of plays a significant role in the major clinical treatment challenge of tuberculosis, such as its long treatment cycle, antibiotic resistance,...
INTRODUCTION
The unique dormancy of plays a significant role in the major clinical treatment challenge of tuberculosis, such as its long treatment cycle, antibiotic resistance, immune escape, and high latent infection rate.
METHODS
To determine the function of MtrA, the only essential response regulator, one strategy was developed to establish its regulatory network according to high-quality genome-wide binding sites.
RESULTS AND DISCUSSION
The complex modulation mechanisms were implied by the strong bias distribution of MtrA binding sites in the noncoding regions, and 32.7% of the binding sites were located inside the target genes. The functions of 288 potential MtrA target genes predicted according to 294 confirmed binding sites were highly diverse, and DNA replication and damage repair, lipid metabolism, cell wall component biosynthesis, cell wall assembly, and cell division were the predominant pathways. Among the 53 pathways shared between dormancy/resuscitation and persistence, which accounted for 81.5% and 93.0% of the total number of pathways, respectively, MtrA regulatory genes were identified not only in 73.6% of their mutual pathways, but also in 75.4% of the pathways related to dormancy/resuscitation and persistence respectively. These results suggested the pivotal roles of MtrA in regulating dormancy/resuscitation and the apparent relationship between dormancy/resuscitation and persistence. Furthermore, the finding that 32.6% of the MtrA regulons were essential and/or for provided new insight into its indispensability. The findings mentioned above indicated that MtrA is a novel promising therapeutic target for tuberculosis treatment since the crucial function of MtrA may be a point of weakness for .
PubMed: 38952446
DOI: 10.3389/fmicb.2024.1415554 -
Scientific Reports Jun 2024Deamination of bases is a form of DNA damage that occurs spontaneously via the hydrolysis and nitrosation of living cells, generating hypoxanthine from adenine. E. coli...
Deamination of bases is a form of DNA damage that occurs spontaneously via the hydrolysis and nitrosation of living cells, generating hypoxanthine from adenine. E. coli endonuclease V (eEndoV) cleaves hypoxanthine-containing double-stranded DNA, whereas human endonuclease V (hEndoV) cleaves hypoxanthine-containing RNA; however, hEndoV in vivo function remains unclear. To date, hEndoV has only been examined using hypoxanthine, because it binds closely to the base located at the cleavage site. Here, we examined whether hEndoV cleaves other lesions (e.g., AP site, 6-methyladenine, xanthine) to reveal its function and whether 2'-nucleoside modification affects its cleavage activity. We observed that hEndoV is hypoxanthine-specific; its activity was the highest with 2'-OH modification in ribose. The cleavage activity of hEndoV was compared based on its base sequence. We observed that it has specificity for adenine located on the 3'-end of hypoxanthine at the cleavage site, both before and after cleavage. These data suggest that hEndoV recognizes and cleaves the inosine generated on the poly A tail to maintain RNA quality. Our results provide mechanistic insight into the role of hEndoV in vivo.
Topics: Inosine; Humans; Poly A; Substrate Specificity; Hypoxanthine; Endodeoxyribonucleases
PubMed: 38951658
DOI: 10.1038/s41598-024-65814-7 -
The EMBO Journal Jul 2024Cells have evolved a robust and highly regulated DNA damage response to preserve their genomic integrity. Although increasing evidence highlights the relevance of RNA...
Cells have evolved a robust and highly regulated DNA damage response to preserve their genomic integrity. Although increasing evidence highlights the relevance of RNA regulation, our understanding of its impact on a fully efficient DNA damage response remains limited. Here, through a targeted CRISPR-knockout screen, we identify RNA-binding proteins and modifiers that participate in the p53 response. Among the top hits, we find the mA reader YTHDC1 as a master regulator of p53 expression. YTHDC1 binds to the transcription start sites of TP53 and other genes involved in the DNA damage response, promoting their transcriptional elongation. YTHDC1 deficiency also causes the retention of introns and therefore aberrant protein production of key DNA damage factors. While YTHDC1-mediated intron retention requires mA, TP53 transcriptional pause-release is promoted by YTHDC1 independently of mA. Depletion of YTHDC1 causes genomic instability and aberrant cancer cell proliferation mediated by genes regulated by YTHDC1. Our results uncover YTHDC1 as an orchestrator of the DNA damage response through distinct mechanisms of co-transcriptional mRNA regulation.
PubMed: 38951610
DOI: 10.1038/s44318-024-00153-x -
Nature Communications Jun 2024Argonaute proteins are the central effectors of RNA-guided RNA silencing pathways in eukaryotes, playing crucial roles in gene repression and defense against viruses and...
Argonaute proteins are the central effectors of RNA-guided RNA silencing pathways in eukaryotes, playing crucial roles in gene repression and defense against viruses and transposons. Eukaryotic Argonautes are subdivided into two clades: AGOs generally facilitate miRNA- or siRNA-mediated silencing, while PIWIs generally facilitate piRNA-mediated silencing. It is currently unclear when and how Argonaute-based RNA silencing mechanisms arose and diverged during the emergence and early evolution of eukaryotes. Here, we show that in Asgard archaea, the closest prokaryotic relatives of eukaryotes, an evolutionary expansion of Argonaute proteins took place. In particular, a deep-branching PIWI protein (HrAgo1) encoded by the genome of the Lokiarchaeon 'Candidatus Harpocratesius repetitus' shares a common origin with eukaryotic PIWI proteins. Contrasting known prokaryotic Argonautes that use single-stranded DNA as guides and/or targets, HrAgo1 mediates RNA-guided RNA cleavage, and facilitates gene silencing when expressed in human cells and supplied with miRNA precursors. A cryo-EM structure of HrAgo1, combined with quantitative single-molecule experiments, reveals that the protein displays structural features and target-binding modes that are a mix of those of eukaryotic AGO and PIWI proteins. Thus, this deep-branching archaeal PIWI may have retained an ancestral molecular architecture that preceded the functional and mechanistic divergence of eukaryotic AGOs and PIWIs.
Topics: Argonaute Proteins; Humans; RNA Interference; Archaea; RNA, Small Interfering; Archaeal Proteins; Cryoelectron Microscopy; MicroRNAs; Evolution, Molecular; Phylogeny
PubMed: 38951509
DOI: 10.1038/s41467-024-49452-1 -
Biochemistry Research International 2024The plant has been utilized in folk medicine. Analyzing phytochemical composition of dichloromethane/methanol (1 : 1) root part of gave oleic acid (), caffeic...
The plant has been utilized in folk medicine. Analyzing phytochemical composition of dichloromethane/methanol (1 : 1) root part of gave oleic acid (), caffeic acid-2-hydroxynonylester (), catechin (), and a pregnane derivative (). NMR spectroscopy was used to characterize compounds , while compound was identified through GC-MS analysis and literature comparison. The cytotoxicity of extracts from roots of was conducted against MCF-7 cell lines (human breast cancer) by MTT assay. According to the cytotoxicity study, -hexane extract exhibited a high level of toxicity with 28.9 ± 5.6% cell viability. Antibacterial activity was tested against , , , and The highest bacterial growth mean inhibition zone was measured for catechin (3) (13.72 ± 0.05 mm)) against at 0.25 mg/mL and acceptable related to standard. Antioxidant activity was studied by the DPPH assay. Based on the data from the antioxidant study, DCM/MeOH extract (70.32%) and catechin () showed good antioxidant activity (65.61%) (IC 0.25 g/mL) relative to that of the positive control (78.21%, IC 0.014 g/mL) at 12.5 g/mL. In each docking pose, catechin () scored higher binding affinity of -7.9, -7.2, and -6.4 kcal/mol towards PqsA, DNA gyraseB, and PK, respectively, compared to amoxicillin (-8.1, -6.1, and -6.4 kcal/mol). All five Lipinski rules were obeyed by compounds , which showed an acceptable drug resemblance. The lipophilicity was computed as less than five (1.47-4.01) indicating a lipophilic property. Catechin () obeys Veber's rule implying its good oral bioavailability. Binding affinity scores of catechin ()-protein interactions are in line with those from tests, indicating its potential antibacterial effect. The obtained cytotoxicity and antibacterial activity results support the utilization of in folk medicine.
PubMed: 38948887
DOI: 10.1155/2024/3713620 -
BioRxiv : the Preprint Server For... Jun 2024The XPD/Rad3-like helicase, YoaA, and DNA polymerase III subunit, χ, are involved in DNA damage tolerance and repair. YoaA and χ promote tolerance to the DNA...
The XPD/Rad3-like helicase, YoaA, and DNA polymerase III subunit, χ, are involved in DNA damage tolerance and repair. YoaA and χ promote tolerance to the DNA chain-terminator, 3□-azidothymidine (AZT), and together form the functional helicase complex, YoaA-χ. How YoaA-χ contributes to DNA damage tolerance is not well understood. single-stranded DNA binding protein (SSB) accumulates at stalled replication forks, and the SSB-χ interaction is required to promote AZT tolerance via an unknown mechanism. YoaA-χ and SSB interactions were investigated to better understand this DNA damage tolerance mechanism, and we discovered YoaA-χ and SSB have a functional interaction. SSB confers a substrate-specific effect on the helicase activity of YoaA-χ, barely affecting YoaA-χ on an overhang DNA substrate but inhibiting YoaA-χ on forked DNA. A paralog helicase, DinG, unwinds SSB-bound DNA in a similar manner to YoaA-χ on the substrates tested. Through use of ensemble experiments, we believe SSB binds behind YoaA-χ relative to the DNA ds/ss junction and show via single-molecule assays that SSB translocates along ssDNA with YoaA-χ. This is, to our knowledge, the first demonstration of a mechanoenzyme pulling SSB along ssDNA.
PubMed: 38948847
DOI: 10.1101/2024.06.21.600097 -
BioRxiv : the Preprint Server For... Jun 2024Unique for a eukaryote, protein-coding genes in trypanosomes are arranged in polycistronic units (PTUs). This genome arrangement has led to a model where Pol II...
Unique for a eukaryote, protein-coding genes in trypanosomes are arranged in polycistronic units (PTUs). This genome arrangement has led to a model where Pol II transcription of PTUs is unregulated. The initial step in trypanosome lytic factor (TLF) mediated lysis of requires high affinity haptoglobin/hemoglobin receptor (HpHbR) binding. Here we demonstrate that by selection with TLF, resistance is obtained in a stepwise process correlating with loss of HpHbR expression at an allelic level. RNA-seq, Pol II ChIP and run-on analysis indicate HpHbR silencing is at the transcriptional level, where loss of Pol II binding at the promoter region specifically shuts down transcription of the HpHbR containing gene cluster and the adjacent opposing gene cluster. Reversible transcriptional silencing of the divergent PTUs correlates with DNA base J modification of the shared promoter region. Therefore, epigenetic mechanisms exist to regulate gene expression via Pol II transcription initiation of gene clusters in a mono-allelic fashion. These findings suggest epigenetic chromatin-based regulation of gene expression is deeply conserved among eukaryotes, including primitive eukaryotes that rely on polycistronic transcription.
PubMed: 38948844
DOI: 10.1101/2024.06.21.600114 -
BioRxiv : the Preprint Server For... Jun 2024Invasive mucinous adenocarcinoma (IMA) comprises ∼5% of lung adenocarcinoma. There is no effective therapy for IMA when surgical resection is not possible. IMA is...
BACKGROUND
Invasive mucinous adenocarcinoma (IMA) comprises ∼5% of lung adenocarcinoma. There is no effective therapy for IMA when surgical resection is not possible. IMA is sometimes confused with adenocarcinoma with signet ring cell features (SRCC) pathologically since both adenocarcinomas feature tumor cells with abundant intracellular mucin. The molecular mechanisms by which such mucin-producing lung adenocarcinomas develop remain unknown.
METHODS
Using a Visium spatial transcriptomics approach, we analyzed IMA and compared it with SRCC patho-transcriptomically. Combining spatial transcriptomics data with studies using RNA-seq and ChIP-seq, we assessed downstream targets of transcription factors HNF4A and SPDEF that are highly expressed in IMA and/or SRCC.
RESULTS
Spatial transcriptomics analysis indicated that there are 6 distinct cell clusters in IMA and SRCC. Notably, two clusters (C1 and C3) of mucinous tumor cells exist in both adenocarcinomas albeit at a different ratio. Importantly, a portion of genes (e.g., , , and ) are distinctly expressed while some mucous-related genes (e.g., and ) are expressed in both adenocarcinomas. We determined that HNF4A induces and and that BI 6015, an HNF4A antagonist, suppressed the growth of IMA cells. Using mutant SPDEF that is associated with COVID-19, we also determined that an intact DNA-binding domain of SPDEF is required for SPDEF-mediated induction of mucin genes ( , and ). Additionally, we found that XMU-MP-1, a SPDEF inhibitor, suppressed the growth of IMA cells.
CONCLUSION
These results revealed that IMA and SRCC contain heterogenous tumor cell types, some of which are targetable.
PubMed: 38948839
DOI: 10.1101/2024.06.13.598839 -
BioRxiv : the Preprint Server For... Jun 2024The multidrug-resistant, nosocomial pathogen is a major threat to human health. A sensor kinase-response regulator system, BfmS-BfmR, is a potential antimicrobial...
The multidrug-resistant, nosocomial pathogen is a major threat to human health. A sensor kinase-response regulator system, BfmS-BfmR, is a potential antimicrobial target in the bacterium due to its essential role in promoting drug resistance and virulence. Important questions remain, however, about how the system controls resistance and pathogenesis. Although knockout of BfmR is known to alter expression of >1000 genes, its direct regulon is undefined. Moreover, how phosphorylation controls BfmR is unclear. Here, we address these problems by combining mutagenesis, ChIP-seq, and reactions using a small phosphodonor to study how phosphorylation affects BfmR function. We show that phosphorylation requires the BfmR active site Asp58 and is essential to gene regulation, antibiotic resistance, and virulence in a sepsis model. Consistent with activation of the protein, phosphorylation induces dimerization and increases its affinity for target DNA. Integrated analysis of the genome-wide binding and transcriptional profiles of BfmR led to several key findings: (1) Phosphorylation dramatically expands the number of genomic sites bound by BfmR, from 4 to >250; (2) BfmR recognizes a direct repeat motif widespread across promoters; (3) BfmR directly regulates >300 genes as activator (eg, capsule, peptidoglycan, and outer membrane biogenesis) or repressor (eg, type IV pilus machinery); (4) The regulator also directly controls a set of non-coding sRNAs. These studies reveal the centrality of a phosphorylation signal in driving resistance and pathogenicity and unravel the extensive gene regulatory network under its control.
PubMed: 38948834
DOI: 10.1101/2024.06.16.599214