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Redox Biology Apr 2024Defects of human trophoblast cells may induce miscarriage (abnormal early embryo loss), which is generally regulated by lncRNAs. Ferroptosis is a newly identified...
Defects of human trophoblast cells may induce miscarriage (abnormal early embryo loss), which is generally regulated by lncRNAs. Ferroptosis is a newly identified iron-dependent programmed cell death. Hypoxia is an important and unavoidable feature in mammalian cells. However, whether hypoxia might induce trophoblast cell ferroptosis and then induce miscarriage, as well as regulated by a lncRNA, was completely unknown. In this work, we discovered at the first time that hypoxia could result in ferroptosis of human trophoblast cells and then induce miscarriage. We also identified a novel lncRNA (lnc-HZ06) that simultaneously regulated hypoxia (indicated by HIF1α protein), ferroptosis, and miscarriage. In mechanism, HIF1α-SUMO, instead of HIF1α itself, primarily acted as a transcription factor to promote the transcription of NCOA4 (ferroptosis indicator) in hypoxic trophoblast cells. Lnc-HZ06 promoted the SUMOylation of HIF1α by suppressing SENP1-mediated deSUMOylation. HIF1α-SUMO also acted as a transcription factor to promote lnc-HZ06 transcription. Thus, both lnc-HZ06 and HIF1α-SUMO formed a positive auto-regulatory feedback loop. This loop was up-regulated in hypoxic trophoblast cells, in RM villous tissues, and in placental tissues of hypoxia-treated mice, which further induced ferroptosis and miscarriage by up-regulating HIF1α-SUMO-mediated NCOA4 transcription. Furthermore, knockdown of either murine lnc-hz06 or Ncoa4 could efficiently suppress ferroptosis and alleviate miscarriage in hypoxic mouse model. Taken together, this study provided new insights in understanding the regulatory roles of lnc-HZ06/HIF1α-SUMO/NCOA4 axis among hypoxia, ferroptosis, and miscarriage, and also offered an effective approach for treatment against miscarriage.
Topics: Mice; Female; Humans; Pregnancy; Animals; Abortion, Spontaneous; Ferroptosis; RNA, Long Noncoding; Placenta; Cell Hypoxia; Hypoxia; Transcription Factors; Trophoblasts; Mammals; Nuclear Receptor Coactivators
PubMed: 38335622
DOI: 10.1016/j.redox.2024.103073 -
International Journal of Molecular... Mar 2024Obstructive sleep apnoea (OSA) and components of metabolic syndrome (MetS) are inextricably connected. Considering the increasing burden of MetS and OSA, in the present... (Review)
Review
Obstructive sleep apnoea (OSA) and components of metabolic syndrome (MetS) are inextricably connected. Considering the increasing burden of MetS and OSA, in the present review, we aimed to collate and summarise the potential pathophysiological mechanisms linking these pathologies. In short, obesity appears to promote OSA development via multiple pathways, some of which are not directly related to mass but rather to metabolic complications of obesity. Simultaneously, OSA promotes weight gain through central mechanisms. On the other hand, diabetes mellitus contributes to OSA pathophysiology mainly through effects on peripheral nerves and carotid body desensitization, while intermittent hypoxia and sleep fragmentation are the principal culprits in OSA-mediated diabetes. Apart from a bidirectional pathophysiological relationship, obesity and diabetes mellitus together additively increase cardiovascular risk in OSA patients. Additionally, the emergence of new drugs targeting obesity and unequivocal results of the available studies underscore the need for further exploration of the mechanisms linking MetS and OSA, all with the aim of improving outcomes in these patients.
Topics: Humans; Metabolic Syndrome; Obesity; Diabetes Mellitus; Sleep Apnea, Obstructive; Hypoxia
PubMed: 38542217
DOI: 10.3390/ijms25063243 -
International Journal of Molecular... Feb 2024Obstructive sleep apnea (OSA), a respiratory sleep disorder associated with cardiovascular diseases, is more prevalent in men. However, OSA occurrence in pregnant women... (Review)
Review
Obstructive sleep apnea (OSA), a respiratory sleep disorder associated with cardiovascular diseases, is more prevalent in men. However, OSA occurrence in pregnant women rises to a level comparable to men during late gestation, creating persistent effects on both maternal and offspring health. The exact mechanisms behind OSA-induced cardiovascular diseases remain unclear, but inflammation and oxidative stress play a key role. Animal models using intermittent hypoxia (IH), a hallmark of OSA, reveal several pro-inflammatory signaling pathways at play in males, such as TLR4/MyD88/NF-κB/MAPK, miRNA/NLRP3, and COX signaling, along with shifts in immune cell populations and function. Limited evidence suggests similarities in pregnancies and offspring. In addition, suppressing these inflammatory molecules ameliorates IH-induced inflammation and tissue injury, providing new potential targets to treat OSA-associated cardiovascular diseases. This review will focus on the inflammatory mechanisms linking IH to cardiovascular dysfunction in males, pregnancies, and their offspring. The goal is to inspire further investigations into the understudied populations of pregnant females and their offspring, which ultimately uncover underlying mechanisms and therapeutic interventions for OSA-associated diseases.
Topics: Male; Animals; Humans; Female; Pregnancy; Cardiovascular Diseases; Hypoxia; Sleep Apnea, Obstructive; Immunity; Inflammation
PubMed: 38339130
DOI: 10.3390/ijms25031852 -
EBioMedicine Aug 2023Therapeutic hypothermia (TH) is standard of care for moderate to severe neonatal hypoxic ischemic encephalopathy (HIE) but many survivors still suffer lifelong... (Observational Study)
Observational Study
BACKGROUND
Therapeutic hypothermia (TH) is standard of care for moderate to severe neonatal hypoxic ischemic encephalopathy (HIE) but many survivors still suffer lifelong disabilities and benefits of TH for mild HIE are under active debate. Development of objective diagnostics, with sensitivity to mild HIE, are needed to select, guide, and assess response to treatment. The objective of this study was to determine if cerebral oxygen metabolism (CMRO) in the days after TH is associated with 18-month neurodevelopmental outcomes as the first step in evaluating CMRO's potential as a diagnostic for HIE. Secondary objectives were to compare associations with clinical exams and characterise the relationship between CMRO and temperature during TH.
METHODS
This was a prospective, multicentre, observational, cohort study of neonates clinically diagnosed with HIE and treated with TH recruited from the tertiary neonatal intensive care units (NICUs) of Boston Children's Hospital, Brigham and Women's Hospital, and Beth Israel Deaconess Medical Center between December 2015 and October 2019 with follow-up to 18 months. In total, 329 neonates ≥34 weeks gestational age admitted with perinatal asphyxia and suspected HIE were identified. 179 were approached, 103 enrolled, 73 received TH, and 64 were included. CMRO was measured at the NICU bedside by frequency-domain near-infrared and diffuse correlation spectroscopies (FDNIRS-DCS) during the late phases of hypothermia (C), rewarming (RW) and after return to normothermia (NT). Additional variables were body temperature and clinical neonatal encephalopathy (NE) scores, as well as findings from magnetic resonance imaging (MRI) and spectroscopy (MRS). Primary outcome was the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) at 18 months, normed (SD) to 100 (15).
FINDINGS
Data quality for 58 neonates was sufficient for analysis. CMRO changed by 14.4% per °C (95% CI, 14.2-14.6) relative to its baseline at NT while cerebral tissue oxygen extraction fraction (cFTOE) changed by only 2.2% per °C (95% CI, 2.1-2.4) for net changes from C to NT of 91% and 8%, respectively. Follow-up data for 2 were incomplete, 33 declined and 1 died, leaving 22 participants (mean [SD] postnatal age, 19.1 [1.2] month; 11 female) with mild to moderate HIE (median [IQR] NE score, 4 [3-6]) and 21 (95%) with BSID-III scores >85 at 18 months. CMRO at NT was positively associated with cognitive and motor composite scores (β (SE) = 4.49 (1.55) and 2.77 (1.00) BSID-III points per 10 moL/dl × mm/s, P = 0.009 and P = 0.01 respectively; linear regression); none of the other measures were associated with the neurodevelopmental outcomes.
INTERPRETATION
Point of care measures of CMRO in the NICU during C and RW showed dramatic changes and potential to assess individual response to TH. CMRO following TH outperformed conventional clinical evaluations (NE score, cFTOE, and MRI/MRS) at predicting cognitive and motor outcomes at 18 months for mild to moderate HIE, providing a promising objective, physiologically-based diagnostic for HIE.
FUNDING
This clinical study was funded by an NIH grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, United States (R01HD076258).
Topics: Infant, Newborn; Infant; Pregnancy; Humans; Female; Young Adult; Adult; Cohort Studies; Prospective Studies; Hypoxia-Ischemia, Brain; Infant, Newborn, Diseases; Oxygen; Hypothermia, Induced
PubMed: 37392599
DOI: 10.1016/j.ebiom.2023.104673 -
Cell Death & Disease Feb 2024Cellular senescence is a stress response mechanism that induces proliferative arrest. Hypoxia can bypass senescence and extend the lifespan of primary cells, mainly by...
Cellular senescence is a stress response mechanism that induces proliferative arrest. Hypoxia can bypass senescence and extend the lifespan of primary cells, mainly by decreasing oxidative damage. However, how hypoxia promotes these effects prior to malignant transformation is unknown. Here we observed that the lifespan of mouse embryonic fibroblasts (MEFs) is increased when they are cultured in hypoxia by reducing the expression of p16, p15 and p21. We found that proliferating MEFs in hypoxia overexpress Tfcp2l1, which is a main regulator of pluripotency and self-renewal in embryonic stem cells, as well as stemness genes including Oct3/4, Sox2 and Nanog. Tfcp2l1 expression is lost during culture in normoxia, and its expression in hypoxia is regulated by Hif1α. Consistently, its overexpression in hypoxic levels increases the lifespan of MEFs and promotes the overexpression of stemness genes. ATAC-seq and Chip-seq experiments showed that Tfcp2l1 regulates genes that control proliferation and stemness such as Sox2, Sox9, Jarid2 and Ezh2. Additionally, Tfcp2l1 can replicate the hypoxic effect of increasing cellular reprogramming. Altogether, our data suggest that the activation of Tfcp2l1 by hypoxia contributes to immortalization prior to malignant transformation, facilitating tumorigenesis and dedifferentiation by regulating Sox2, Sox9, and Jarid2.
Topics: Animals; Mice; Carcinogenesis; Cell Transformation, Neoplastic; Cells, Cultured; Cellular Senescence; Fibroblasts; Hypoxia
PubMed: 38418821
DOI: 10.1038/s41419-024-06567-z -
Journal of Translational Medicine Jul 2023Pulmonary arterial hypertension (PAH) is a highly prevalent cardiopulmonary disorder characterized by vascular remodeling and increased resistance in pulmonary artery....
BACKGROUND
Pulmonary arterial hypertension (PAH) is a highly prevalent cardiopulmonary disorder characterized by vascular remodeling and increased resistance in pulmonary artery. Mitochondrial coiled-coil-helix-coiled-coil-helix domain (CHCHD)-containing proteins have various important pathophysiological roles. However, the functional roles of CHCHD proteins in hypoxic PAH is still ambiguous. Here, we aimed to investigate the role of CHCHD4 in hypoxic PAH and provide new insight into the mechanism driving the development of PAH.
METHODS
Serotype 1 adeno-associated viral vector (AAV) carrying Chchd4 was intratracheally injected to overexpress CHCHD4 in Sprague Dawley (SD) rats. The Normoxia groups of animals were housed at 21% O. Hypoxia groups were housed at 10% O, for 8 h/day for 4 consecutive weeks. Hemodynamic and histological characteristics are investigated in PAH. Primary pulmonary artery smooth muscle cells of rats (PASMCs) are used to assess how CHCHD4 affects proliferation and migration.
RESULTS
We found CHCHD4 was significantly downregulated among CHCHD proteins in hypoxic PASMCs and lung tissues from hypoxic PAH rats. AAV1-induced CHCHD4 elevation conspicuously alleviates vascular remodeling and pulmonary artery resistance, and orchestrates mitochondrial oxidative phosphorylation in PASMCs. Moreover, we found overexpression of CHCHD4 impeded proliferation and migration of PASMCs. Mechanistically, through lung tissues bulk RNA-sequencing (RNA-seq), we further identified CHCHD4 modulated mitochondrial dynamics by directly interacting with SAM50, a barrel protein on mitochondrial outer membrane surface. Furthermore, knockdown of SAM50 reversed the biological effects of CHCHD4 overexpression in isolated PASMCs.
CONCLUSIONS
Collectively, our data demonstrated that CHCHD4 elevation orchestrates mitochondrial oxidative phosphorylation and antagonizes aberrant PASMC cell growth and migration, thereby disturbing hypoxic PAH, which could serve as a promising therapeutic target for PAH treatment.
Topics: Animals; Rats; Hypoxia; Mitochondrial Proteins; Oxidative Phosphorylation; Pulmonary Arterial Hypertension; Rats, Sprague-Dawley; Vascular Remodeling; Mitochondrial Precursor Protein Import Complex Proteins
PubMed: 37438854
DOI: 10.1186/s12967-023-04268-3 -
Frontiers in Immunology 2023Although higher incidence of cancer represents a major burden for obstructive sleep apnea (OSA) patients, the molecular pathways driving this association are not...
INTRODUCTION
Although higher incidence of cancer represents a major burden for obstructive sleep apnea (OSA) patients, the molecular pathways driving this association are not completely understood. Recently, the adhesion receptor P-selectin glycoprotein-1 (PSGL 1) has been identified as a novel immune checkpoint, which are recognized major hallmarks in several types of cancer and have revolutionized cancer therapy.
METHODS
The expression of PSGL-1 and its ligands VISTA and SIGLEC-5 was assessed in the leucocytes of OSA patients and control subjects exploring the role of intermittent hypoxia (IH) using models. In addition, PSGL-1 impact on T-cells function was evaluated by models.
RESULTS
Data showed PSGL-1 expression is upregulated in the T-lymphocytes from patients with severe OSA, indicating a relevant role of hypoxemia mediated by intermittent hypoxia. Besides, results suggest an inhibitory role of PSGL-1 on T-cell proliferation capacity. Finally, the expression of SIGLEC-5 but not VISTA was increased in monocytes from OSA patients, suggesting a regulatory role of intermittent hypoxia.
DISCUSSION
In conclusion, PSGL-1 might constitute an additional immune checkpoint leading to T-cell dysfunction in OSA patients, contributing to the disruption of immune surveillance, which might provide biological plausibility to the higher incidence and aggressiveness of several tumors in these patients.
Topics: Humans; Hypoxia; Membrane Glycoproteins; Neoplasms; Sialic Acid Binding Immunoglobulin-like Lectins; Sleep Apnea, Obstructive; T-Lymphocytes
PubMed: 37854605
DOI: 10.3389/fimmu.2023.1277551 -
Stem Cells Translational Medicine Dec 2023Many advanced human cancers contain regions of intratumoral hypoxia, with O2 gradients extending to anoxia. Hypoxia-inducible factors (HIFs) are activated in hypoxic...
Many advanced human cancers contain regions of intratumoral hypoxia, with O2 gradients extending to anoxia. Hypoxia-inducible factors (HIFs) are activated in hypoxic cancer cells and drive metabolic reprogramming, vascularization, invasion, and metastasis. Hypoxia induces breast cancer stem cell (BCSC) specification by inducing the expression and/or activity of the pluripotency factors KLF4, NANOG, OCT4, and SOX2. Recent studies have identified HIF-1-dependent expression of PLXNB3, NARF, and TERT in hypoxic breast cancer cells. PLXNB3 binds to and activates the MET receptor tyrosine kinase, leading to activation of the SRC non-receptor tyrosine kinase and subsequently focal adhesion kinase, which promotes cancer cell migration and invasion. PLXNB3-MET-SRC signaling also activates STAT3, a transcription factor that mediates increased NANOG gene expression. Hypoxia-induced NARF binds to OCT4 and serves as a coactivator by stabilizing OCT4 binding to the KLF4, NANOG, and SOX2 genes and by stabilizing the interaction of OCT4 with KDM6A, a histone demethylase that erases repressive trimethylation of histone H3 at lysine 27, thereby increasing KLF4, NANOG, and SOX2 gene expression. In addition to increasing pluripotency factor expression by these mechanisms, HIF-1 directly activates expression of the TERT gene encoding telomerase, the enzyme required for maintenance of telomeres, which is required for the unlimited self-renewal of BCSCs. HIF-1 binds to the TERT gene and recruits NANOG, which serves as a coactivator by promoting the subsequent recruitment of USP9X, a deubiquitinase that inhibits HIF-1α degradation, and p300, a histone acetyltransferase that mediates acetylation of H3K27, which is required for transcriptional activation.
Topics: Humans; Female; Hypoxia-Inducible Factor 1; Breast Neoplasms; Hypoxia; Gene Expression Regulation, Neoplastic; Neoplastic Stem Cells; Ubiquitin Thiolesterase
PubMed: 37768037
DOI: 10.1093/stcltm/szad061 -
Clinical and Translational Medicine Feb 2024Defective decidualization of endometrial stromal cells (ESCs) in endometriosis (EM) patients leads to inadequate endometrial receptivity and EM-associated infertility....
Defective decidualization of endometrial stromal cells (ESCs) in endometriosis (EM) patients leads to inadequate endometrial receptivity and EM-associated infertility. Hypoxia is an inevitable pathological process of EM and participates in deficient decidualization of the eutopic secretory endometrium. Enhancer of zeste homology 2 (EZH2) is a methyltransferase which catalyses H3K27Me3, leading to decreased expression levels of target genes. Although EZH2 expression is low under normal decidualization, it is abundantly increased in the eutopic secretory endometrium of EM and is induced by hypoxia. Chromatin immunoprecipitation-PCR results revealed that decidua marker IGFBP1 is a direct target of EZH2, partially explaining the increased levels of histone methylation modification in defected decidualization of EM. To mechanism controlling this, we examined the effects of hypoxia on EZH2 and decidualization. EZH2 mRNA showed decreased m A modification and increased expression levels under hypoxia and decidualization combined treatment. Increased EZH2 expression was due to the increased expression of m A demethylase ALKBH5 and decreased expression of the m A reader protein YTHDF2. YTHDF2 directly bind to the m A modification site of EZH2 to promote EZH2 mRNA degradation in ESCs. Moreover, selective Ezh2 depletion in mouse ESCs increased endometrial receptivity and improved mouse fertility by up-regulating decidua marker IGFBP1 expression. This is the first report showing that YTHDF2 can act as a m A reader to promote decidualization by decreasing the stability of EZH2 mRNA and further increasing the expression of IGFBP1 in ESCs. Taken together, our findings highlight the critical role of EZH2/H3K27Me3 in decidualization and reveal a novel epigenetic mechanism by which hypoxia can suppress EM decidualization by decreasing the m A modification of EZH2 mRNA.
Topics: Female; Humans; Animals; Mice; Endometriosis; Histones; RNA; Infertility; Transcription Factors; RNA, Messenger; Methylation; Hypoxia
PubMed: 38344897
DOI: 10.1002/ctm2.1564 -
PeerJ 2023Individual hypoxia tolerance is a major influence on the course and outcome of infectious and inflammatory diseases. Macrophages, which play central roles in systemic...
Individual hypoxia tolerance is a major influence on the course and outcome of infectious and inflammatory diseases. Macrophages, which play central roles in systemic inflammatory response and other immunity reactions, are subject to functional activation orchestrated by several transcription factors including hypoxia inducible factors (HIFs). HIF-1 expression levels and the lipopolysaccharide (LPS)-induced systemic inflammatory response severity have been shown to correlate with hypoxia tolerance. Molecular and functional features of macrophages, depending on the organisms resistance to hypoxia, can determine the severity of the course of infectious and inflammatory diseases, including the systemic inflammatory response. The purpose is the comparative molecular and functional characterization of non-activated and LPS-activated bone marrow-derived macrophages under normoxia in rats with different tolerance to oxygen deprivation. Hypoxia resistance was assessed by gasping time measurement in an 11,500 m altitude-equivalent hypobaric decompression chamber. Based on the outcome, the animals were assigned to three groups termed 'tolerant to hypoxia' ( = 12), 'normal', and 'susceptible to hypoxia' ( = 13). The 'normal' group was excluded from subsequent experiments. One month after hypoxia resistance test, the blood was collected from the tail vein to isolate monocytes. Non-activated and LPS-activated macrophage cultures were investigated by PCR, flow cytometry and Western blot methods. Gene expression patterns of non-activated cultured macrophages from tolerant and susceptible to hypoxia animals differed. We observed higher expression of VEGF and CD11b and lower expression of , and in non-activated cultures obtained from tolerant to hypoxia animals, whereas HIF-1α mRNA and protein expression levels were similar. LPS-activated macrophage cultures derived from susceptible to hypoxia animals expressed higher levels of and CCR7 than the tolerant group; in addition, the activation was associated with increased content of HIF-1α in cell culture medium. The observed differences indicate a specific propensity toward pro-inflammatory macrophage polarization in susceptible to hypoxia rats.
Topics: Rats; Animals; Lipopolysaccharides; Macrophages; Hypoxia; Monocytes; Disease Susceptibility; Systemic Inflammatory Response Syndrome
PubMed: 37842051
DOI: 10.7717/peerj.16052