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BioRxiv : the Preprint Server For... Jan 2024Male germ cells, which are responsible for producing millions of genetically diverse sperm through meiosis in the testis, rely on lactate as their central energy...
Male germ cells, which are responsible for producing millions of genetically diverse sperm through meiosis in the testis, rely on lactate as their central energy metabolite. Recent study has revealed that lactate induces epigenetic modification in cells through histone lactylation, a post-translational modification involving the addition of lactyl groups to lysine residues on histones. Here we report dynamic histone lactylation at histone H4-lysine 5 (K5), -K8, and -K12 during meiosis prophase I in mouse spermatogenesis. By profiling genome-wide occupancy of histone H4-K8 lactylation (H4K8la), which peaks at zygotene, our data show that H4K8la mark is observed at the promoters of genes exhibiting active expression with Gene Ontology (GO) functions enriched for meiosis. Notably, our data also demonstrate that H4K8la is closely associated with recombination hotspots, where machinery involved in the processing DNA double-stranded breaks (DSBs), such as SPO11, DMC1, RAD51, and RPA2, is engaged. In addition, H4K8la was also detected at the meiosis-specific cohesion sites (marked by RAD21L and REC8) flanking the recombination hotspots. Collectively, our findings suggest that histone lactylation serves as a novel mechanism through which lactate regulates germ cell meiosis.
PubMed: 38328171
DOI: 10.1101/2024.01.25.576681 -
Microscopy Research and Technique Aug 2023Industrial activities and unconscious consumption of natural resources cause environmental pollution with the rapid increase in the world population. As a result of the...
Industrial activities and unconscious consumption of natural resources cause environmental pollution with the rapid increase in the world population. As a result of the widespread use of iron oxide nanoparticles (Fe O NP) with nano-industrial activities, it is predicted that this NP will accumulate in the air, water, and soil. In the present study, the purpose was to find out the genotoxic effects on root meristem cells of the Triticum aestivum L. plant, which is an indicator organism exposed to 20-40 nm Fe O NPs at different concentrations (100, 200, and 400 ppm). The amount of Fe O NP accumulated in T. aestivum used in the study was determined with x-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), SEM element map, and EDS characteristic spectrum. All concentrations of Fe O NP caused significant decreases in the mitotic index. Fe O NPs significantly increased the frequency of mitotic abnormalities in T. aestivum root tip cells at all treatment times and all concentrations when compared to the control. Fe O NPs were formed by various mitotic abnormalities such as loss of genetic material, deconstructed prophase, adhesion, chromosome groupings in metaphase, deconstructed metaphase, C-Metaphase, chromosomal loss, chromosomal fracture, polyploidy, deconstructed anaphase, lagging chromosome, fragment, polar deviation, bridging, propagation, asynchronous division, star anaphase, multipolarity, and deconstructed telophase. All these results show that Fe O NPs are genotoxic and clastogenic and may also cause DNA damage. Briefly, these data show that Fe O NPs taken by organisms may pose a danger to the organism and the upper consumer. These findings also show that the production and use of Fe O NPs, which affect organisms, must be controlled, and ultimately, be safely disposed of to reduce their bioaccumulation. RESEARCH HIGHLIGHTS: In the present study, the purpose was to find out the genotoxic effects on root meristem cells of the Triticum aestivum L. (bread wheat) plant, which is an indicator organism exposed to 20-40 nm Fe O NPs at different concentrations (100, 200, and 400 ppm). The amount of Fe O NP accumulated in T. aestivum used in the study was determined with x-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), SEM element map, and EDS characteristic spectrum. The mitotic index was calculated to reveal the genotoxic effect. "Loss of genetic material, deconstructed prophase, adhesion, chromosome groupings in metaphase, deconstructed metaphase, C-Metaphase, chromosomal loss, chromosomal fracture, polyploidy, deconstructed anaphase, lagging chromosome, fragment, polar deviation, bridging, propagation, asynchronous division, star Chromosomal abnormalities such as anaphase, multipolarity, and deconstructed telophase" were visualized. Fe O NPs are genotoxic and clastogenic and may also cause DNA damage.
Topics: Triticum; Nanoparticles; DNA Damage; Chromosome Aberrations; Polyploidy
PubMed: 37357999
DOI: 10.1002/jemt.24377 -
Nature Communications May 2024The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an...
The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an undifferentiated cancer with high mortality. We show here that depletion of the PIAS2 beta isoform with a transcribed double-stranded RNA-directed RNA interference (PIAS2b-dsRNAi) specifically inhibits growth of ATC cell lines and patient primary cultures in vitro and of orthotopic patient-derived xenografts (oPDX) in vivo. Critically, PIAS2b-dsRNAi does not affect growth of normal or non-anaplastic thyroid tumor cultures (differentiated carcinoma, benign lesions) or cell lines. PIAS2b-dsRNAi also has an anti-cancer effect on other anaplastic human cancers (pancreas, lung, and gastric). Mechanistically, PIAS2b is required for proper mitotic spindle and centrosome assembly, and it is a dosage-sensitive protein in ATC. PIAS2b depletion promotes mitotic catastrophe at prophase. High-throughput proteomics reveals the proteasome (PSMC5) and spindle cytoskeleton (TUBB3) to be direct targets of PIAS2b SUMOylation at mitotic initiation. These results identify PIAS2b-dsRNAi as a promising therapy for ATC and other aggressive anaplastic carcinomas.
Topics: Humans; Protein Inhibitors of Activated STAT; Animals; Cell Line, Tumor; Mitosis; Mice; Thyroid Neoplasms; RNA Interference; Spindle Apparatus; Molecular Chaperones; Xenograft Model Antitumor Assays; Proteasome Endopeptidase Complex; Sumoylation; Carcinoma; Female
PubMed: 38744818
DOI: 10.1038/s41467-024-47751-1 -
Cell Reports Jan 2024Dynamic chromosome remodeling and nuclear compartmentalization take place during mammalian meiotic prophase I. We report here that the crucial roles of male...
Dynamic chromosome remodeling and nuclear compartmentalization take place during mammalian meiotic prophase I. We report here that the crucial roles of male pachynema-specific protein (MAPS) in pachynema progression might be mediated by its liquid-liquid phase separation in vitro and in cellulo. MAPS forms distinguishable liquid phases, and deletion or mutations of its N-terminal amino acids (aa) 2-9 disrupt its secondary structure and charge properties, impeding phase separation. Maps pachytene spermatocytes exhibit defects in nucleus compartmentalization, including defects in forming sex bodies, altered nucleosome composition, and disordered chromatin accessibility. Maps male mice expressing MAPS protein lacking aa 2-9 phenocopy Maps mice. Moreover, a frameshift mutation in C3orf62, the human counterpart of Maps, is correlated with nonobstructive azoospermia in a patient exhibiting pachynema arrest in spermatocyte development. Hence, the phase separation property of MAPS seems essential for pachynema progression in mouse and human spermatocytes.
Topics: Humans; Male; Mice; Animals; Chromatin; Meiosis; Pachytene Stage; Phase Separation; Meiotic Prophase I; Spermatocytes; Mammals
PubMed: 38175751
DOI: 10.1016/j.celrep.2023.113651 -
PloS One 2023Wee1-like protein kinase 2 (WEE2) is an oocyte-specific protein tyrosine kinase involved in the regulation of oocyte meiotic arrest in humans. As such, it has been...
Wee1-like protein kinase 2 (WEE2) is an oocyte-specific protein tyrosine kinase involved in the regulation of oocyte meiotic arrest in humans. As such, it has been proposed as a candidate for non-hormonal female contraception although pre-clinical models have not been reported. Therefore, we developed two novel knockout mouse models using CRISPR/Cas9 to test loss-of-function of Wee2 on female fertility. A frameshift mutation at the Wee2 translation start codon in exon 2 had no effect on litter size, litter production, or the ability of oocytes to maintain prophase I arrest. Because of the lack of a reproductive phenotype, we additionally generated a Wee2 allele with a large deletion by removing all coding exons. While there was no difference in the total number of litters produced, homozygous Wee2 female knockout mice with the larger deletion produced fewer pups than heterozygous littermates. Furthermore, there was no difference for key reproductive parameters measured in the mouse models, including ovarian weight, number of ovulated oocytes, or oocytes that underwent in vitro maturation. Therefore, as loss of Wee2 in mice shows only minor effects on overall fecundity, contraceptive development with WEE2 should consider exploiting alternative properties such as gain-of-function or protein-protein interactions, as Wee2 loss-of-function is likely complicated by biological redundancies with other proteins co-expressed in oocytes.
Topics: Humans; Female; Animals; Mice; Protein Kinases; Cell Cycle Proteins; Oocytes; Fertility; Protein-Tyrosine Kinases
PubMed: 37527245
DOI: 10.1371/journal.pone.0289083 -
Nature Communications Apr 2024Programmed DNA double-strand break (DSB) formation is a crucial feature of meiosis in most organisms. DSBs initiate recombination-mediated linking of homologous...
Programmed DNA double-strand break (DSB) formation is a crucial feature of meiosis in most organisms. DSBs initiate recombination-mediated linking of homologous chromosomes, which enables correct chromosome segregation in meiosis. DSBs are generated on chromosome axes by heterooligomeric focal clusters of DSB-factors. Whereas DNA-driven protein condensation is thought to assemble the DSB-machinery, its targeting to chromosome axes is poorly understood. We uncover in mice that efficient biogenesis of DSB-machinery clusters requires seeding by axial IHO1 platforms. Both IHO1 phosphorylation and formation of axial IHO1 platforms are diminished by chemical inhibition of DBF4-dependent kinase (DDK), suggesting that DDK contributes to the control of the axial DSB-machinery. Furthermore, we show that axial IHO1 platforms are based on an interaction between IHO1 and the chromosomal axis component HORMAD1. IHO1-HORMAD1-mediated seeding of the DSB-machinery on axes ensures sufficiency of DSBs for efficient pairing of homologous chromosomes. Without IHO1-HORMAD1 interaction, residual DSBs depend on ANKRD31, which enhances both the seeding and the growth of DSB-machinery clusters. Thus, recombination initiation is ensured by complementary pathways that differentially support seeding and growth of DSB-machinery clusters, thereby synergistically enabling DSB-machinery condensation on chromosomal axes.
Topics: Mice; Animals; Cell Cycle Proteins; DNA Breaks, Double-Stranded; DNA; Meiosis; Synaptonemal Complex; Recombination, Genetic; Homologous Recombination
PubMed: 38580643
DOI: 10.1038/s41467-024-47020-1 -
Schizophrenia Research Jun 2024The literature has paid very little attention to pericarditis, pericardial effusion and pancreatitis during clozapine treatment in children and adolescents.
BACKGROUND
The literature has paid very little attention to pericarditis, pericardial effusion and pancreatitis during clozapine treatment in children and adolescents.
METHODS
Cases of clozapine-associated pericarditis and pancreatitis in children were studied using searches in: 1) PubMed (June 16, 2023), and 2) the World Health Organization's pharmacovigilance database (June 1, 2022), VigiBase. VigiBase uses a logarithmic measure of disproportionality called the information component (IC).
RESULTS
The PubMed search yielded 3 clozapine-associated pericarditis cases, 1 pancreatitis case and 1 with both. VigiBase provided a significant clozapine-associated pericarditis IC = 3.6 with an IC = 2.9 (only 3 cases were expected while 22 were observed). VigiBase provided a significant clozapine-associated pancreatitis IC = 2.2 with an IC = 1.4 (only 3 cases were expected while 16 were observed). In VigiBase clozapine-associated pericarditis and pericardial effusion in youth looked similar and on a continuum with myocarditis, as myocarditis, pericarditis and pancreatitis appeared to occur mainly during clozapine titration. Combining PubMed and VigiBase we identified: 1) 29 cases of at least possible clozapine-associated pericarditis/pericardial effusion (6 probable and 23 possible) including 7 cases with and 22 without myocarditis, and 2) 17 cases of clozapine-associated pancreatitis (1 definite and 16 possible). Two of the pancreatitis cases occurred during overdoses. No fatal outcomes were found in any clozapine-associated pericarditis and pancreatitis cases.
CONCLUSIONS
Despite the lack of attention in the literature to clozapine-associated pericarditis and pancreatitis, results demonstrate that they can happen in youth, particularly during titration. Pericarditis and pancreatitis appear to be forms of clozapine-associated inflammation during dose titration.
Topics: Humans; Pancreatitis; Clozapine; Pericarditis; Pharmacovigilance; Adolescent; Child; Antipsychotic Agents; Databases, Factual; Male; Female; Pericardial Effusion
PubMed: 37981478
DOI: 10.1016/j.schres.2023.10.027 -
Current Biology : CB Mar 2024In most eukaryotes, balanced chromosome segregation at meiosis requires crossovers, but female Bombyx mori lack these structures. Instead, the synaptonemal complex is...
In most eukaryotes, balanced chromosome segregation at meiosis requires crossovers, but female Bombyx mori lack these structures. Instead, the synaptonemal complex is repurposed to compensate for this absence of crossovers, a remarkable example of exaptation.
Topics: Animals; Female; Elephants; Bombyx; Meiosis; Synaptonemal Complex; Eukaryota; Chromosome Segregation
PubMed: 38471453
DOI: 10.1016/j.cub.2024.01.046 -
Andrology Feb 2024The ubiquitin ligase HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 is essential for the establishment and maintenance of spermatogonia. However, the...
BACKGROUND
The ubiquitin ligase HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 is essential for the establishment and maintenance of spermatogonia. However, the role of HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 in regulating germ cell differentiation remains unclear, and clinical evidence linking HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 to male infertility pathogenesis is lacking.
OBJECTIVE
This study aims to investigate the role of HUWE1 in germ cell differentiation and the mechanism by which a HUWE1 single nucleotide polymorphism increases male infertility risk.
MATERIALS AND METHODS
We analyzed HUWE1 single nucleotide polymorphisms in 190 non-obstructive azoospermia patients of Han Chinese descent. We evaluated HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 regulation by retinoic acid receptor alpha using chromatin immunoprecipitation assays, electrophoretic mobility shift assays, and siRNA-mediated RARα knockdown. Using C18-4 spermatogonial cells, we determined whether HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 participated in retinoic acid-mediated retinoic acid receptor alpha signaling. We performed luciferase assays, cell counting kit-8 assays, immunofluorescence, quantitative real-time polymerase chain reaction, and western blotting. We quantified HUWE1 and retinoic acid receptor alpha in testicular biopsies from non-obstructive azoospermia and obstructive azoospermia patients using quantitative real-time polymerase chain reaction and immunofluorescence.
RESULTS
Three HUWE1 single nucleotide polymorphisms were significantly associated with spermatogenic failure in 190 non-obstructive azoospermia patients; one (rs34492591) was in the HUWE1 promoter. Retinoic acid receptor alpha regulates HUWE1 gene expression by binding to its promoter. HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 participates in retinoic acid/retinoic acid receptor alpha signaling pathway and regulates the expression of germ cell differentiation genes STRA8 and SCP3 to inhibit cell proliferation and reduce γH2AX accumulation. Notably, significantly lower levels of HUWE1 and RARα were detected in testicular biopsy samples from non-obstructive azoospermia patients.
CONCLUSIONS
An HUWE1 promoter single nucleotide polymorphism significantly downregulates its expression in non-obstructive azoospermia patients. Mechanistically, HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 regulates germ cell differentiation during meiotic prophase through its participation in retinoic acid/retinoic acid receptor alpha signaling and subsequent modulation of γH2AX. Taken together, these results strongly suggest that the genetic polymorphisms of HUWE1 are closely related to spermatogenesis and non-obstructive azoospermia pathogenesis.
Topics: Humans; Male; Polymorphism, Single Nucleotide; Meiosis; Azoospermia; Retinoic Acid Receptor alpha; Ubiquitin-Protein Ligases; Tretinoin; China; Tumor Suppressor Proteins
PubMed: 37290064
DOI: 10.1111/andr.13474 -
Proceedings of the National Academy of... May 2024In the meiotic prophase, programmed DNA double-strand breaks are repaired by meiotic recombination. Recombination-defective meiocytes are eliminated to preserve genome...
In the meiotic prophase, programmed DNA double-strand breaks are repaired by meiotic recombination. Recombination-defective meiocytes are eliminated to preserve genome integrity in gametes. BRCA1 is a critical protein in somatic homologous recombination, but studies have suggested that BRCA1 is dispensable for meiotic recombination. Here we show that BRCA1 is essential for meiotic recombination. Interestingly, BRCA1 also has a function in eliminating recombination-defective oocytes. knockout (KO) rescues the survival of KO oocytes far more efficiently than removing CHK2, a vital component of the DNA damage checkpoint in oocytes. Mechanistically, BRCA1 activates chromosome asynapsis checkpoint by promoting ATR activity at unsynapsed chromosome axes in KO oocytes. Moreover, KO also rescues the survival of asynaptic KO oocytes. Collectively, our study not only unveils an unappreciated role of chromosome asynapsis in eliminating recombination-defective oocytes but also reveals the dual functions of BRCA1 in safeguarding oocyte genome integrity.
Topics: Oocytes; Animals; BRCA1 Protein; Female; Mice; Cell Cycle Proteins; Mice, Knockout; Meiosis; Ataxia Telangiectasia Mutated Proteins; DNA Breaks, Double-Stranded; Chromosome Pairing; Endodeoxyribonucleases; Checkpoint Kinase 2; Phosphate-Binding Proteins; Recombination, Genetic; Homologous Recombination; Genomic Instability
PubMed: 38696471
DOI: 10.1073/pnas.2401386121