Homeostasis of postmitotic and proliferating cells is maintained by pathways that repress stress. We found that the Caenorhabditis elegans histone 3 lysine 4 (H3K4) demethylases RBR-2 and SPR-5 promoted postmitotic longevity of stress-resistant daf-2 adults, altered pools of methylated H3K4, and promoted silencing of some daf-2 target genes. In addition, RBR-2 and SPR-5 were required for germ cell immortality at a high temperature. Transgenerational proliferative aging was enhanced for spr-5; rbr-2 double mutants, suggesting that these histone demethylases may function sequentially to promote germ cell immortality by targeting distinct H3K4 methyl marks. RBR-2 did not play a comparable role in the maintenance of quiescent germ cells in dauer larvae, implying that it represses stress that occurs as a consequence of germ cell proliferation, rather than stress that accumulates in nondividing cells. We propose that H3K4 demethylase activities promote the maintenance of chromatin states during stressful growth conditions, thereby repressing postmitotic aging of somatic cells as well as proliferative aging of germ cells.
Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric and Gynaecological Diseases, State Key Laboratory of Common Mechanism Research for Major Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Background: Ovarian cancer (OC) is a heterogeneous malignancy with multiple histological subtypes, showing global variability in incidence. Temporal changes in diagnostic criteria and risk factors might influence the incidence and distribution of OC and its subtypes.
Methods: This study analyzed incidence patterns (2013-2017) and trends (1988-1992 to 2013-2017) of OC and its subtypes across 65 and 40 countries, respectively.
Biochemical signaling arising from mechanical force-induced physical changes in biological macromolecules is a critical determinant of key physiological processes across all biological lengths and time scales. Recent studies have deepened our understanding of how mechano-transduction regulates somatic tissues such as those in alveolar, gastrointestinal, embryonic, and skeleto-muscular systems. The germline of an organism has a heterogeneous composition - of germ cells at different stages of maturation and mature gametes, often supported and influenced by their accessory somatic tissues.
Chameleons are a family of lizards distinguished by several unique features related to their arboreal lifestyles, such as a ballistic tongue, skin color changes, independent movement of both eyes, a prehensile tail, and cleft hands and feet. The veiled chameleon (Chamaeleo calyptratus) has been proposed as a promising model species for studying squamate biology. Despite its potential, the developmental biology of this species remains poorly understood, particularly in terms of gonadal development.
One of the major age-related declines in female reproductive function is the reduced quantity and quality of oocytes. Here we demonstrate that structural changes in the zona pellucida (ZP) were associated with decreased fertilization rates from 34- to 38-week-old female mice, equivalent to the mid-reproductive of human females. In middle-aged mouse ovaries, the decline in the number of transzonal projections was accompanied by a decrease in cumulus cell-oocyte interactions, resulting in a deterioration of the oocyte quality.
Germ cell tumors (GCTs) are chemosensitive neoplasms with high cure rates; however, a small group of patients present tumors with refractory chemotherapy, with a dismal prognosis and few effective management options. Although immune checkpoint inhibitors (ICIs) are approved for use in chemotherapy refractory GCT, the evidence supporting this indication remains scarce. Original research studies were included on patients with GCTs refractory to chemotherapy treated with ICI up to December 2023.
