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PubMed2025

Balancing LncRNA H19 and miR-675 Bioconversion as a Key Regulator of Embryonic Myogenesis Under Maternal Obesity.

BACKGROUND: Maternal obesity (MO) impairs fetal skeletal muscle development, but the underlying mechanisms remain poorly defined. The regulatory roles of lncRNA H19 and its first exon derived microRNA675 (miR675) in prenatal muscle development remain to be examined. H19/Igf2 are in the same imprinting cluster with H19 expressed from the maternal allele while Igf2 expresses paternally. H19 contains a G-rich loop, and KH-type splicing regulatory protein (KHSRP) mediates the biogenesis of pre-miRNAs containing G-rich loops, which depends on its phosphorylation by AKT, a key mediator of IGF2 signalling. This study aims to depict the elusive function of these regulators that are affected by MO during embryonic myogenesis. METHODS: Single-cell transcriptomic sequencing and GeoMx spatial RNA sequencing were performed to identify the differentially expressed genes between embryos from MO and control (CT) mice. Both E11.5 and E13.5 embryos were collected and analysed to validate the sequencing data. The roles of H19 and miR657 in myogenesis were further analysed in P19 embryonic cells via CRISPR/dCas9-mediated H19 activation and inhibition. The epigenetic changes of H19 were analysed by methylated DNA immunoprecipitation, and allele-targeted analysis of H19 was performed by crossing C57BL/6J and CAST/EiJ mice. RESULTS: Transcriptomic analysis showed that MO embryos contained less differentiated myocytes (1.34%) than CT embryos (2.86%). Myogenesis-related GO biological processes were down-regulated in the MO embryonic myotome region. MO embryos showed lower expression of myogenic transcription factors such as Myf5, Myod1, Myog, Mef2c and Myh3 (p&#x2009;<&#x2009;0.05). MO altered epigenetic modifications of the H19 genomic cluster, showing a decreased methylation level in H19 imprinting control region (p&#x2009;<&#x2009;0.05) and a diallelic expression pattern of H19, which elevated its expression in MO embryos. Overexpression of H19 inhibited myogenesis in P19 cells, but miR675 promoted myogenesis, suggesting the critical regulatory roles of bioconversion of H19 to miR675. A KHSRP mediates the biogenesis of miR675, a process that relies on its phosphorylation by IGF2/AKT signalling. Knocking-down of KHSRP and inhibition of AKT abolished miR675 biogenesis. MO suppressed IGF2/AKT signalling and blocked KHSRP-dependent miR675 biogenesis in embryos. CONCLUSIONS: We found differential effects of H19 and miR675 on embryonic myogenesis. MO up-regulates H19 but blocks its miR675 bioconversion via suppressing IGF2/AKT/KHSRP signalling axis. Myogenesis in MO embryos was impeded due to the highly accumulated H19 and blocked miR675 biogenesis.

RNA, Long Noncoding↗
PubMed2025

Long noncoding RNA H19 promotes the acquisition of a mesenchymal-like invasive phenotype in mesothelial primary cells through an HDAC1-mediated WT1/Sp1 switch.

Peritoneal fibrosis is a pathological alteration of the peritoneal membrane occurring in pro-inflammatory conditions, including peritoneal dialysis (PD), a renal replacement therapy. Characteristic of this process is the acquisition of invasive/pro-fibrotic abilities by mesothelial cells (MCs) through induction of mesothelial to mesenchymal transition (MMT), a cell-specific form of EMT. Long noncoding (lnc) RNAs act as major players in physiologic regulatory circuitries of the cell. While LncRNA-H19 (lncH19), one of the first lncRNAs identified, has been broadly studied in tumorigenesis, its role in peritoneum fibrotic diseases has been scarcely addressed so far. Aim of this study was to investigate the role of H19 in the acquisition of a mesenchymal-like phenotype in primary fibrotic MCs from PD patients, and to elucidate epigenetic mechanisms controlling its expression. Genetic silencing/ectopic expression experiments revealed that H19 promoted the expression of MMT markers while downregulating the epithelial marker E-Cadherin, and favored MC directed migration and invasion on a collagen matrix. Silencing of three main H19 isoforms revealed a synergistic activity in the induction of a mesenchymal phenotype. Treatment with MS-275, an HDAC1-3 specific inhibitor previously known to promote MMT reversal, as well as HDAC1 genetic silencing, downregulated lncRNA H19 expression. Bioinformatic analysis revealed a binding sequence of Wilm's Tumor Protein 1 (WT1), the master gene of mesothelial differentiation, on the H19 promoter at an area with multiple acetylation peaks partially overlapping the binding site of Specificity protein 1 (Sp1), another transcription factor active in cellular plasticity regulation. Genetic silencing and Chromatin Immunoprecipitation (ChIP) experiments demonstrated that HDAC1 inhibition promotes a switch between WT1 and Sp1 in H19 promoter occupancy, favoring an inhibitory effect of WT1 on H19 expression and the reversal towards an epithelial-like phenotype. Overall, we discovered an HDAC1-WT1/Sp1-H19 axis potentially relevant to the design of new therapies aimed at counteracting peritoneal fibrosis.

RNA, Long Noncoding↗
PubMed2026

LncRNA H19 promotes vascular remodeling by inhibiting MFN2.

Neointimal hyperplasia, featuring excessive proliferation and migration of vascular smooth muscle cells (VSMCs), is crucial in vascular remodeling diseases. Long non-coding RNA (lncRNA) H19 promotes vascular remodeling, yet underlying mechanisms remain incompletely elucidated. Here, we investigated whether H19 acts via its derivative miR-675-5p. Bioinformatics found a conserved H19/miR-675-5p/MFN2 (mitofusin 2) axis. Cell assays were performed to evaluate the effects of H19 and miR-675-5p on VSMC proliferation and migration. The dual-luciferase reporter gene assay was used to assess the interaction between miR-675-5p and Mfn2 mRNA. The mouse model of common carotid artery ligation was used to evaluate the role of H19 in neointimal hyperplasia. Our data suggested that knockdown of H19 inhibited VSMC proliferation and migration, as well as neointimal hyperplasia. Mechanistically, H19 regulated MFN2 through miR-675-5p, leading to ERK1/2 (extracellular signal-regulated kinase 1/2) activation. In conclusion, we suggest that targeting the H19/miR-675-5p/MFN2/ERK1/2 axis may help to treat vascular remodeling diseases.

Animals↗
PubMed1977

[Immunodepressive activity of cell fractions of Escherichia coli O138:K81:H19].

A soluble cell fraction (cytosol), an O-antigen (endotoxin), and an unsoluble cell ingredient were isolated from a 24-hour culture of Escherichia coli O138:K81:H19. Their immunosuppressive action was determined by using the tuberculin test and the survival rate of the allographts. It was found that: 1. Cytosol appears to be a slightly toxic preparation with well expressed immunosuppressive action. 2. The endotoxin is highly toxic, producing the same effect as cytosol. 3. The unsoluble cell ingredient is a comparatively toxic preparation, producing an undependable immunosuppressive effect. Discussed is the mechanism of the immunosuppressive activity of the investigated subcellular fractions. It believed to be due to a certain injurious action on the function of the T-cells.

Animals↗
PubMed1979

[Immunostimulating activity of certain subcellular fractions of Escherichia coli O138:K81:H19].

A 24-hour culture of Escherichia coli 0138:K81:H19 was used to isolate a soluble cytoplasmic fraction, an O antigen, and an unsolube cell ingredient. Their immunogenic action was followed up through subcutaneous vaccination of mice and the production of humoral antibodies in rabbits. It was found that the cytoplasmic ingredient was a slightly toxic protective antigen forming considerable immunity in mice and a comparatively high titer of antibodies in rabbit sera. The unsoluble cell ingredient and the O antigen proved comparatively toxic and did not produce favourable immune response. Discussed in the use of the cytoplasmic ingredient as a vaccine as well as the type of the immunoglobulins produced.

Animals↗
PubMed2026

Combined effects of urine exposure and cryopreservation on sperm quality: an in vitro study of retrograde ejaculation.

Sperm quality influences fertility and offspring health through both genomic inheritance and epigenetic inheritance. Thus, for use in clinical-assisted reproductive technology (ART), spermatozoa must have optimal genomic and epigenetic structures. In patients with retrograde ejaculation, spermatozoa are usually recovered from urine and then cryopreserved for ART. However, the effects of urine exposure and subsequent freeze-thaw cycles on sperm quality remain unclear. This is particularly true for epigenetic changes and their underlying mechanisms. In this study, we examined how different durations of urine exposure (10 min and 40 min) followed by freeze-thaw cycles affected sperm motility, DNA integrity, and methylation levels of imprinting genes (H19-imprinted maternally expressed transcript [ H19 ], mesoderm-specific transcript [ MEST ], and the transposable element Alu [ Alu ]). As the duration of urine exposure increased, sperm motility (median [interquartile range]) decreased from 48.0% (39.0%-52.5%) to 1.0% (1.0%-5.0%), the DNA fragmentation index (DFI; median [interquartile range]) increased from 12.0% (9.3%-19.9%) to 23.5% (13.9%-33.9%), the MEST methylation level (mean &#xb1; standard deviation [s.d.]) increased from 3.8% &#xb1; 1.5% to 11.5 &#xb1; 1.2%, and the H19 methylation level (mean &#xb1; s.d.) decreased from 86.9% &#xb1; 0.9% to 82.1% &#xb1; 0.5%. The freeze-thaw process further reduced sperm motility, while the DFI and methylation levels of MEST and H19 did not significantly change. The Alu methylation level remained stable. These findings demonstrate that urine exposure affects sperm motility, DNA integrity, and methylation levels of some imprinting genes. These effects intensify over time. In contrast, the freeze-thaw process impacts only sperm motility. In clinical practice, minimizing exposure to urine might improve sperm quality.

Humans↗
PubMed2026

Deoxyribonucleic acid methylation abnormalities at imprinted loci in oligospermic and azoospermic men.

OBJECTIVE: To assess deoxyribonucleic acid (DNA) methylation at imprinted and repetitive genomic regions in ejaculated and testicular sperm from men with oligospermia, azoospermia, and those undergoing vasectomy reversal (VR), compared with fertile controls. DESIGN: Observational case-control study. SUBJECTS: Samples were obtained from 68 men, including 29 infertile men (18 oligospermic [5-15 million/mL], 11 severely oligospermic [<5 million/mL]) and 20 fertile controls with confirmed natural conceptions. Testicular tissue was collected from 11 azoospermic men (7 obstructive azoospermia [OA], 4 nonobstructive azoospermia [NOA]) and 8 men with prior paternity undergoing VR. EXPOSURE: Sperm DNA methylation at four imprinted genes (H19, GTL2, MEST, and LIT1) and one repetitive element (LINE1). MAIN OUTCOME MEASURES: Methylation levels at CpG sites determined by bisulfite pyrosequencing. RESULTS: The H19 was significantly hypomethylated only in severe oligospermia compared with fertile controls, whereas other groups showed nonsignificant trends with overlapping distributions. In contrast, MEST was significantly hypermethylated in oligospermic, azoospermic, and VR groups compared with fertile controls. No significant differences were observed for GTL2, LIT1, or LINE1. CONCLUSION: The DNA methylation abnormalities in sperm are locus-specific and vary across infertility phenotypes. MEST alterations were consistent across groups, whereas H19 changes were limited to severe oligospermia. Similar methylation patterns in testicular sperm from azoospermic and VR groups suggest that epigenetic alterations may reflect the testicular environment or obstruction, or differences between testicular and ejaculated sperm.

Humans↗
PubMed2025

Genomic epidemiology of enteropathogenic Escherichia coli in southwestern Nigeria.

BACKGROUND: Enteropathogenic Escherichia coli (EPEC) are etiological agents of diarrhea. We studied the genetic diversity and virulence factors of EPEC in southwestern Nigeria, where this pathotype is rarely characterized. METHODOLOGY/PRINCIPAL FINDINGS: EPEC isolates (n&#x2009;=&#x2009;96) recovered from recent southwestern Nigeria diarrhea case-control studies were whole genome-sequenced using Illumina technology. Genomes were assembled using SPAdes and quality was evaluated using QUAST. Virulencefinder, Ectyper, and ResFinder were used to identify virulence genes, serotypes, and resistance genes. Multilocus sequence typing was done by STtyping. Single nucleotide polymorphisms (SNPs) were called out of whole genome alignment using SNP-sites and a phylogenetic tree was constructed using IQtree. Thirty-nine of the 96(40.6%) EPEC isolates were from diarrhea cases diarrhea. Nine isolates from diarrhea patients and four from healthy controls were typical EPEC, harboring bundle-forming pilus (bfp) genes whilst the rest were atypical EPEC. There were 15 EPEC-EAEC hybrids. Atypical serotypes O71:H19 (16, 16.6%), O108:H21 (6, 6.3%), O157:H39 (5, 5.2%), and O165:H9 (4, 4.2%) were the most prevalent; only 8 (8.3%) isolates belonged to classical EPEC serovars. The largest, ST517 clade harbored multiple siderophore and serine protease autotransporter genes and included an O71:H19 subclade <10 SNPs apart, representing a likely outbreak involving 15 children, four with diarrhea. Likely outbreaks, of typical O119:H6(ST28) and atypical O127:H29(ST7798) were additionally identified. CONCLUSION/SIGNIFICANCE: EPEC circulating in southwestern Nigeria are diverse and differ substantially from well-characterized lineages seen previously elsewhere. EPEC carriage and outbreaks could be commonplace but are largely undetected, hence, unreported, and require genomic surveillance for identification.

Nigeria↗
PubMed2026

Long noncoding RNAs and diabetic retinopathy: Current understanding, future directions and challenges.

Diabetic retinopathy remains as the leading cause of preventable blindness in working-aged people. The pathophysiology of this sight-threatening disease is complex and involves intricate interactions among metabolic, hemodynamic and epigenetic pathways, leading to molecular, structural, functional and genomic abnormalities in retinal vascular and nonvascular cells. Diabetes also results in differential expressions of several noncoding RNAs, including micro RNAs (miRNAs) and long noncoding RNAs (LncRNAs). Compared to about 2000 miRNA identified in human genome thus far, more than 30,000 LncRNA transcripts have been already identified, but the function and mechanism of action of most of the LncRNAs is still not fully characterized, and there remains a possibility that some LncRNAs could have diverse functions under different contexts. LncRNAs are mainly noncoding, but they have many regulatory functions, and regulate gene expression by interacting with DNA, RNA and protein. Aberrant expressions of several LncRNAs including MALAT1, MEG3, HOTAIR, MIAT1 and H19, is associated with metabolic abnormalities implicated in the pathogenesis of diabetic retinopathy. LncRNAs are also released into circulation and show high organ and cell specificity, and greater disease-associated differences compared to disease-associated mRNAs. Furthermore, LncRNAs maintain stable expression in the plasma and can be isolated from total RNA present in biological samples including blood, which makes them promising and reliable candidates for diagnostic or prognostic markers and therapeutic targets for various diseases. With continued improvement in innovative RNA modifications and delivery modalities, use of LncRNAs as possible biomarkers, and of LncRNA-based therapeutics, for diabetic retinopathy appears promising.

Biomarkers↗
PubMed1979

A regulatory sequence near the 3' end of sea urchin histone genes.

The 3' flanking sequences of all five histone genes have been sequenced in the histone DNA clone h19 of the sea urchin Psammechinus miliaris. A large (23 bp) and a small (10 bp) conserved sequence was found by sequence comparison, some 29-40 bp downstream from the termination codon. 12 bases of the larger homology block show a dyad symmetry. The available sequences of clone h22 of the same species and those of the histone clones pSp2 and pSp17 of Strongylocentrotus purpuratus, another sea urchin species, fit well into this comparison. Two types of sequences are involved in the dyad symmetry; one is H1, H3 and H4 specific, the other is H2A and H2B specific. If these conserved sequences are transcribed, a hairpin loop could form in the RNA molecules. This secondary structure might serve as a recognition signal for a regulatory protein.

Animals↗
PubMed1978

[Flagellar antigens of E. coli serologically interrlelated to H40, 41 and H41, 42, 43 flagellar antigens of Citrobacter. New H-antigeny E. coli i Citrobacter].

The authors confirmed the reference of the test strains H13 (P6c) and H22 (A231a) of the international collection of E. coli to Citrobacter; their antigenic formula was established. As shown, strains P6c possessed a variety of the H-antigen which was not described in Citrobacter earlier, designated as H41a, 97. Three types of flagellar antigens characterized by the presence of an interrelationship with the partial factor H41 of the flagellar Citrobacter antigens were revealed in E. coli; the partial composition of H-antigenic components common for E. coli and Citrobacter was studied. Two of three new varieties of the E. coli H-antigen revealed was characterized by a cross correlation and a relation to the standard H19 E. coli antigen. The strain with the third variety of the H-antigen was capable of forming the H-antigenic mutants which acquired the antigenic component identical to the standard H16 E. coli antigen. E. coli strain is recommended for the replacement of the strain P6c in the International collection of E. coli.

Agglutinins↗
PubMed2025

The genetic changes in 11p15.5-related pheochromocytomas and paragangliomas.

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors. The development of these tumors is associated with more than 20 genes. The aforementioned genes are subdivided into three clusters. The pseudohypoxic, kinase-signaling and Wnt clusters. The pseudohypoxic cluster is the only one that has been demonstrated to be associated with DNA methylation changes, including alterations in the 11p15.5 region. The objective of this study was to identify alterations in the 11p15.5 region, ascertain their prevalence in PPGLs, and subsequently compare them with the genomic and somatic mutations that cluster PPGLs. One hundred and fifty tumor samples were subjected to analysis. A total of 90 cases (60%) exhibited no alterations in the 11p15.5 region. The most prevalent alterations were maternal allele loss, observed in 45 cases (30%), pUPD (paternal uniparental disomy) in five cases (3.33%), and paternal allele gain in four cases (2.67%). The data presented here suggest that two mechanisms may be involved in the formation of PPGLs. These are reduced expression of CDKN1C (maternal allele deletion) and overexpression of IGF2 (pUPD, paternal allele gain). A statistically significant difference was observed in the frequency of alterations in the 11p15.5 region when comparing cluster 1 and cluster 2 (P-value <0.0001). This study is the first to describe pUPD and paternal allele gain as somatic alterations in PPGLs. In addition, our findings indicate that alterations in the 11p15.5 region are not exclusive to cluster 1. Consequently, the alterations in the 11p15.5 region cannot be regarded as a marker for cluster 1.

Humans↗