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1.
PLoS One ; 15(7): e0232559, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32658922

RESUMO

PRESENILIN 2 (PSEN2) is one of the genes mutated in early onset familial Alzheimer's disease (EOfAD). PSEN2 shares significant amino acid sequence identity with another EOfAD-related gene PRESENILIN 1 (PSEN1), and partial functional redundancy is seen between these two genes. However, the complete range of functions of PSEN1 and PSEN2 is not yet understood. In this study, we performed targeted mutagenesis of the zebrafish psen2 gene to generate a premature termination codon close downstream of the translation start with the intention of creating a null mutation. Homozygotes for this mutation, psen2S4Ter, are viable and fertile, and adults do not show any gross psen2-dependent pigmentation defects, arguing against significant loss of γ-secretase activity. Also, assessment of the numbers of Dorsal Longitudinal Ascending (DoLA) interneurons that are responsive to psen2 but not psen1 activity during embryogenesis did not reveal decreased psen2 function. Transcripts containing the S4Ter mutation show no evidence of destabilization by nonsense-mediated decay. Forced expression in zebrafish embryos of fusions of psen2S4Ter 5' mRNA sequences with sequence encoding enhanced green fluorescent protein (EGFP) indicated that the psen2S4Ter mutation permits utilization of cryptic, novel downstream translation start codons. These likely initiate translation of N-terminally truncated Psen2 proteins lacking late endosomal/lysosomal localization sequences and that obey the "reading frame preservation rule" of PRESENILIN EOfAD mutations. Transcriptome analysis of entire brains from a 6-month-old family of wild type, heterozygous and homozygous psen2S4Ter female siblings revealed profoundly dominant effects on gene expression likely indicating changes in ribosomal, mitochondrial, and anion transport functions.


Assuntos
Códon de Terminação/genética , Perfilação da Expressão Gênica , Mitocôndrias/genética , Mutação , Presenilina-2/genética , Ribossomos/genética , Proteínas de Peixe-Zebra/genética , Alelos , Animais , Contagem de Células , Homozigoto , Hipóxia/genética , Neurônios/citologia , Estabilidade de RNA/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética
2.
Biol Res ; 53(1): 25, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503642

RESUMO

BACKGROUND: Hypoxia inducible factor-1 (HIF-1) is considered as the most activated transcriptional factor in response to low oxygen level or hypoxia. HIF-1 binds the hypoxia response element (HRE) sequence in the promoter of different genes, mainly through the bHLH domain and activates the transcription of genes, especially those involved in angiogenesis and EMT. Considering the critical role of bHLH in binding HIF-1 to the HRE sequence, we hypothesized that bHLH could be a promising candidate to be targeted in hypoxia condition. METHODS: We inserted an inhibitory bHLH (ibHLH) domain in a pIRES2-EGFP vector and transfected HEK293T cells with either the control vector or the designed construct. The ibHLH domain consisted of bHLH domains of both HIF-1a and Arnt, capable of competing with HIF-1 in binding to HRE sequences. The transfected cells were then treated with 200 µM of cobalt chloride (CoCl2) for 48 h to induce hypoxia. Real-time PCR and western blot were performed to evaluate the effect of ibHLH on the genes and proteins involved in angiogenesis and EMT. RESULTS: Hypoxia was successfully induced in the HEK293T cell line as the gene expression of VEGF, vimentin, and ß-catenin were significantly increased after treatment of untransfected HEK293T cells with 200 µM CoCl2. The gene expression of VEGF, vimentin, and ß-catenin and protein level of ß-catenin were significantly decreased in the cells transfected with either control or ibHLH vectors in hypoxia. However, ibHLH failed to be effective on these genes and the protein level of ß-catenin, when compared to the control vector. We also observed that overexpression of ibHLH had more inhibitory effect on gene and protein expression of N-cadherin compared to the control vector. However, it was not statistically significant. CONCLUSION: bHLH has been reported to be an important domain involved in the DNA binding activity of HIF. However, we found that targeting this domain is not sufficient to inhibit the endogenous HIF-1 transcriptional activity. Further studies about the function of critical domains of HIF-1 are necessary for developing a specific HIF-1 inhibitor.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Western Blotting , Expressão Gênica , Células HEK293 , Humanos , Hipóxia/genética , Fator 1 Induzível por Hipóxia/genética , Reação em Cadeia da Polimerase em Tempo Real , Ativação Transcricional/genética
3.
Aquat Toxicol ; 224: 105520, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32480175

RESUMO

Hypoxia, a low environmental oxygen level, is a common problem in the ocean globally. Hypoxia has been known to cause disruption to the endocrine system of marine organisms in both laboratory and field studies. Our previous studies have demonstrated the sex-specific response to hypoxia in the neural and reproductive systems of marine fish. In the current report, we aim to study the sex-specific hepatic response of fish at the transcriptome level to hypoxic stress. By using a comparative transcriptome analysis, followed by a systematic bioinformatics analysis including Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA), we found that hypoxia altered expression of genes related to cell proliferation and apoptosis of hepatocytes, which are associated with human pathologies, such as liver inflammation hepatic steatosis and steatohepatitis. Furthermore, we observed sex-specific responses in the livers of fish through different cell signaling pathways. In female fish, hypoxia causes dysregulation of expression of genes related to impairment in endoplasmic reticulum structure and liver metabolism. In male fish, genes associated with redox homeostasis and fatty acid metabolism were altered by hypoxic stress. The findings of this study support the notion that hypoxia could cause sex-specific changes (hepatic toxicity and changes) in marine fish.


Assuntos
Hipóxia/metabolismo , Oryzias/genética , Estresse Oxidativo/genética , Caracteres Sexuais , Transcriptoma/genética , Animais , Apoptose/genética , Proliferação de Células/genética , Feminino , Humanos , Hipóxia/genética , Hipóxia/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Oryzias/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-32267717

RESUMO

During pregnancy, placental vascular growth, which is essential for supporting the rapidly growing fetus, is associated with marked elevations in blood flow. These vascular changes take place under chronic physiological low O2 (less than 2-8% O2 in human; chronic physiological normoxia, CPN) throughout pregnancy. O2 level below CPN pertinent to the placenta results in placental hypoxia. Such hypoxia can cause severe endothelial dysfunction, which is associated with adverse pregnancy outcomes (e.g., preeclampsia) and high risk of adult-onset cardiovascular diseases in children born to these pregnancy complications. However, our current knowledge about the mechanisms underlying fetoplacental endothelial function is derived primarily from cell models established under atmospheric O2 (~21% O2 at sea level, hyperoxia). Recent evidence has shown that fetoplacental endothelial cells cultured under CPN have distinct gene expression profiles and cellular responses compared with cells cultured under chronic hyperoxia. These data indicate the critical roles of CPN in programming fetal endothelial function and prompt us to re-examine the mechanisms governing fetoplacental endothelial function under CPN. Better understanding these mechanisms will facilitate us to develop preventive and therapeutic strategies for endothelial dysfunction-associated diseases (e.g., preeclampsia). This review will provide a brief summary on the impacts of CPN on endothelial function and its underlying mechanisms with a focus on fetoplacental endothelial cells.


Assuntos
Células Endoteliais/metabolismo , Oxigênio/metabolismo , Placenta/irrigação sanguínea , Pré-Eclâmpsia/genética , Movimento Celular/genética , Células Endoteliais/patologia , Feminino , Feto , Humanos , Hiperóxia/genética , Hiperóxia/metabolismo , Hiperóxia/patologia , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/patologia , Placenta/metabolismo , Placenta/fisiopatologia , Pré-Eclâmpsia/fisiopatologia , Gravidez
5.
Artigo em Inglês | MEDLINE | ID: mdl-32293932

RESUMO

Autophagy is a highly conserved self-protection mechanism that plays a crucial role in cardiovascular diseases. Cardiomyocyte hypoxic injury promotes oxidative stress and pathological alterations in the heart, although the interplay between these effects remains elusive. The transient receptor potential vanilloid 1 (TRPV1) ion channel is a nonselective cation channel that is activated in response to a variety of exogenous and endogenous physical and chemical stimuli. Here, we investigated the effects and mechanisms of action of TRPV1 on autophagy in hypoxic cardiomyocytes. In this study, primary cardiomyocytes isolated from C57 mice were subjected to hypoxic stress, and their expression of TRPV1 and adenosine 5'-monophosphate-activated protein kinase (AMPK) was regulated. The autophagy flux was assessed by Western blotting and immunofluorescence staining, and the cell viability was determined through Cell counting kit-8 assay and Lactate dehydrogenase assays. In addition, the calcium influx after the upregulation of TRPV1 expression in cardiomyocytes was examined. The results showed that the number of autophagosomes in cardiomyocytes was higher under hypoxic stress and that the blockade of autophagy flux aggravated hypoxic damage to cardiomyocytes. Moreover, the expression of TRPV1 was induced under hypoxic stress, and its upregulation by capsaicin improved the autophagy flux and protected cardiomyocytes from hypoxic damage, whereas the silencing of TRPV1 significantly attenuated autophagy. Our observations also revealed that AMPK signaling was activated and involved in TRPV1-induced autophagy in cardiomyocytes under hypoxic stress. Overall, this study demonstrates that TRPV1 activation mitigates hypoxic injury in cardiomyocytes by improving autophagy flux through the AMPK signaling pathway and highlights TRPV1 as a novel therapeutic target for the treatment of hypoxic cardiac disease.


Assuntos
Autofagia/genética , Traumatismos Cardíacos/genética , Proteínas Quinases/genética , Canais de Cátion TRPV/genética , Animais , Cálcio/metabolismo , Capsaicina/farmacologia , Sobrevivência Celular/genética , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Traumatismos Cardíacos/patologia , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/patologia , Camundongos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transdução de Sinais/genética
6.
J Biomed Sci ; 27(1): 39, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32114978

RESUMO

Epithelial-mesenchymal transition (EMT) is an important process triggered during cancer metastasis. Regulation of EMT is mostly initiated by outside signalling, including TGF-ß, growth factors, Notch ligand, Wnt, and hypoxia. Many signalling pathways have been delineated to explain the molecular mechanisms of EMT. In this review, we will focus on the epigenetic regulation of two critical EMT signalling pathways: hypoxia and TGF-ß. For hypoxia, hypoxia-induced EMT is mediated by the interplay between chromatin modifiers histone deacetylase 3 (HDAC3) and WDR5 coupled with the presence of histone 3 lysine 4 acetylation (H3K4Ac) mark that labels the promoter regions of various traditional EMT marker genes (e.g. CDH1, VIM). Recently identified new hypoxia-induced EMT markers belong to transcription factors (e.g. SMO, GLI1) that mediate EMT themselves. For TGF-ß-induced ΕΜΤ, global chromatin changes, removal of a histone variant (H2A.Z), and new chromatin modifiers (e.g. UTX, Rad21, PRMT5, RbBP5, etc) are identified to be crucial for the regulation of both EMT transcription factors (EMT-TFs) and EMT markers (EMT-Ms). The epigenetic mechanisms utilized in these two pathways may serve as good model systems for other signalling pathways and also provide new potential therapeutic targets.


Assuntos
Epigênese Genética , Transição Epitelial-Mesenquimal/genética , Hipóxia/genética , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Humanos , Fator de Crescimento Transformador beta/metabolismo
7.
Clin Sci (Lond) ; 134(6): 593-607, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32129439

RESUMO

Small extracellular vesicles (sEVs) released from the extravillous trophoblast (EVT) are known to regulate uterine spiral artery remodeling during early pregnancy. The bioactivity and release of these sEVs differ under differing oxygen tensions and in aberrant pregnancy conditions. Whether the placental cell-derived sEVs released from the hypoxic placenta contribute to the pathophysiology of preeclampsia is not known. We hypothesize that, in response to low oxygen tension, the EVT packages a specific set of proteins in sEVs and that these released sEVs interact with endothelial cells to induce inflammation and increase maternal systemic blood pressure. Using a quantitative MS/MS approach, we identified 507 differentially abundant proteins within sEVs isolated from HTR-8/SVneo cells (a commonly used EVT model) cultured at 1% (hypoxia) compared with 8% (normoxia) oxygen. Among these differentially abundant proteins, 206 were up-regulated and 301 were down-regulated (P < 0.05), and they were mainly implicated in inflammation-related pathways. In vitro incubation of hypoxic sEVs with endothelial cells, significantly increased (P < 0.05) the release of GM-CSF, IL-6, IL-8, and VEGF, when compared with control (i.e. cells without sEVs) and normoxic sEVs. In vivo injection of hypoxic sEVs into pregnant rats significantly increased (P < 0.05) mean arterial pressure with increases in systolic and diastolic blood pressures. We propose that oxygen tension regulates the release and bioactivity of sEVs from EVT and that these sEVs regulate inflammation and maternal systemic blood pressure. This novel oxygen-responsive, sEVs signaling pathway, therefore, may contribute to the physiopathology of preeclampsia.


Assuntos
Citocinas/metabolismo , Vesículas Extracelulares/química , Hipóxia/fisiopatologia , Oxigênio/metabolismo , Pré-Eclâmpsia/fisiopatologia , Animais , Pressão Arterial , Pressão Sanguínea , Citocinas/genética , Células Endoteliais/química , Células Endoteliais/metabolismo , Vesículas Extracelulares/metabolismo , Feminino , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Oxigênio/análise , Pré-Eclâmpsia/genética , Pré-Eclâmpsia/metabolismo , Gravidez , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Trofoblastos/química , Trofoblastos/metabolismo
8.
Artigo em Inglês | MEDLINE | ID: mdl-32159369

RESUMO

Metabolic reprogramming is considered important in the pathogenesis of the occlusive vasculopathy observed in pulmonary hypertension (PH). However, the mechanisms that link reprogrammed metabolism to aberrant expression of genes, which modulate functional phenotypes of cells in PH, remain enigmatic. Herein, we demonstrate that, in mice, hypoxia-induced PH was prevented by glucose-6-phosphate dehydrogenase deficiency (G6PDDef), and further show that established severe PH in Cyp2c44-/- mice was attenuated by knockdown with G6PD shRNA or by G6PD inhibition with an inhibitor (N-ethyl-N'-[(3ß,5α)-17-oxoandrostan-3-yl]urea, NEOU). Mechanistically, G6PDDef, knockdown and inhibition in lungs: 1) reduced hypoxia-induced changes in cytoplasmic and mitochondrial metabolism, 2) increased expression of Tet methylcytosine dioxygenase 2 (Tet2) gene, and 3) upregulated expression of the coding genes and long noncoding (lnc) RNA Pint, which inhibits cell growth, by hypomethylating the promoter flanking region downstream of the transcription start site. These results suggest functional TET2 is required for G6PD inhibition to increase gene expression and to reverse hypoxia-induced PH in mice. Furthermore, the inhibitor of G6PD activity (NEOU) decreased metabolic reprogramming, upregulated TET2 and lncPINT, and inhibited growth of control and diseased smooth muscle cells isolated from pulmonary arteries of normal individuals and idiopathic-PAH patients, respectively. Collectively, these findings demonstrate a previously unrecognized function for G6PD as a regulator of DNA methylation. These findings further suggest that G6PD acts as a link between reprogrammed metabolism and aberrant gene regulation and plays a crucial role in regulating the phenotype of cells implicated in the pathogenesis of PH, a debilitating disorder with a high mortality rate.


Assuntos
Metilação de DNA/genética , Glucosefosfato Desidrogenase/genética , Hipertensão Pulmonar/genética , Hipóxia/genética , Animais , Proliferação de Células/genética , Família 2 do Citocromo P450/genética , Feminino , Expressão Gênica/genética , Regulação da Expressão Gênica/genética , Pulmão/metabolismo , Masculino , Camundongos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Fenótipo , Artéria Pulmonar/metabolismo , RNA Longo não Codificante/genética , Regulação para Cima/genética
9.
Mol Cell ; 78(3): 382-395.e8, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32183942

RESUMO

N6-Methyldeoxyadenosine (6mA) has recently been shown to exist and play regulatory roles in eukaryotic genomic DNA (gDNA). However, the biological functions of 6mA in mammals have yet to be adequately explored, largely due to its low abundance in most mammalian genomes. Here, we report that mammalian mitochondrial DNA (mtDNA) is enriched for 6mA. The level of 6mA in HepG2 mtDNA is at least 1,300-fold higher than that in gDNA under normal growth conditions, corresponding to approximately four 6mA modifications on each mtDNA molecule. METTL4, a putative mammalian methyltransferase, can mediate mtDNA 6mA methylation, which contributes to attenuated mtDNA transcription and a reduced mtDNA copy number. Mechanistically, the presence of 6mA could repress DNA binding and bending by mitochondrial transcription factor (TFAM). Under hypoxia, the 6mA level in mtDNA could be further elevated, suggesting regulatory roles for 6mA in mitochondrial stress response. Our study reveals DNA 6mA as a regulatory mark in mammalian mtDNA.


Assuntos
DNA Mitocondrial/metabolismo , Desoxiadenosinas/metabolismo , Metiltransferases/metabolismo , Animais , Metilação de DNA , DNA Mitocondrial/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Desoxiadenosinas/genética , Regulação da Expressão Gênica , Células Hep G2 , Humanos , Hipóxia/genética , Metiltransferases/genética , Camundongos Endogâmicos C57BL , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
Biochim Biophys Acta Mol Basis Dis ; 1866(6): 165753, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32126269

RESUMO

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is associated to intermittent hypoxia (IH) and is an aggravating factor of non-alcoholic fatty liver disease (NAFLD). We investigated the effects of hypoxia in both in vitro and in vivo models of NAFLD. METHODS: Primary rat hepatocytes treated with free fatty acids (FFA) were subjected to chemically induced hypoxia (CH) using the hypoxia-inducible factor-1 alpha (HIF-1α) stabilizer cobalt chloride (CoCl2). Triglyceride (TG) content, mitochondrial superoxide production, cell death rates, cytokine and inflammasome components gene expression and protein levels of cleaved caspase-1 were assessed. Also, Kupffer cells (KC) were treated with conditioned medium (CM) and extracellular vehicles (EVs) from hypoxic fat-laden hepatic cells. The choline deficient L-amino acid defined (CDAA)-feeding model used to assess the effects of IH on experimental NAFLD in vivo. RESULTS: Hypoxia induced HIF-1α in cells and animals. Hepatocytes exposed to FFA and CoCl2 exhibited increased TG content and higher cell death rates as well as increased mitochondrial superoxide production and mRNA levels of pro-inflammatory cytokines and of inflammasome-components interleukin-1ß, NLRP3 and ASC. Protein levels of cleaved caspase-1 increased in CH-exposed hepatocytes. CM and EVs from hypoxic fat-laden hepatic cells evoked a pro-inflammatory phenotype in KC. Livers from CDAA-fed mice exposed to IH exhibited increased mRNA levels of pro-inflammatory and inflammasome genes and increased levels of cleaved caspase-1. CONCLUSION: Hypoxia promotes inflammatory signals including inflammasome/caspase-1 activation in fat-laden hepatocytes and contributes to cellular crosstalk with KC by release of EVs. These mechanisms may underlie the aggravating effect of OSAS on NAFLD. [Abstract word count: 257].


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Hipóxia/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Hepatopatia Gordurosa não Alcoólica/genética , Apneia Obstrutiva do Sono/genética , Animais , Caspase 1/genética , Deficiência de Colina/genética , Deficiência de Colina/metabolismo , Deficiência de Colina/patologia , Cobalto/toxicidade , Modelos Animais de Doenças , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patologia , Ácidos Graxos não Esterificados/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Hipóxia/induzido quimicamente , Hipóxia/metabolismo , Hipóxia/patologia , Inflamassomos/genética , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/genética , Macrófagos do Fígado/metabolismo , Macrófagos do Fígado/patologia , Camundongos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos , Apneia Obstrutiva do Sono/etiologia , Apneia Obstrutiva do Sono/metabolismo , Apneia Obstrutiva do Sono/patologia , Triglicerídeos/genética
11.
Epilepsia ; 61(3): 572-588, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32030748

RESUMO

OBJECTIVE: Immediately preceding sudden unexpected death in epilepsy (SUDEP), patients experienced a final generalized tonic-clonic seizure (GTCS), rapid ventilation, apnea, bradycardia, terminal apnea, and asystole. Whether a progressive pathophysiology develops and increases risk of SUDEP remains unknown. Here, we determined (a) heart rate, respiratory rate, and blood oxygen saturation (SaO2 ) in low-risk and high-risk knockout (KO) mice; and (b) whether blocking receptors for orexin, a cardiorespiratory neuromodulator, influences cardiorespiratory function mice or longevity in high-risk KO mice. METHODS: Heart rate and SaO2 were determined noninvasively with ECGenie and pulse oximetry. Respiration was determined with noninvasive airway mechanics technology. The role of orexin was determined within subject following acute treatment with a dual orexin receptor antagonist (DORA, 100 mg/kg). The number of orexin neurons in the lateral hypothalamus was determined with immunohistochemistry. RESULTS: Intermittent bradycardia was more prevalent in high-risk KO mice, an effect that may be the result of increased parasympathetic drive. High-risk KO mice had more orexin neurons in the lateral hypothalamus. Blocking of orexin receptors differentially influenced heart rate in KO, but not wild-type (WT) mice. When DORA administration increased heart rate, it also decreased heart rate variability, breathing frequency, and/or hypopnea-apnea. Blocking orexin receptors prevented the methacholine (MCh)-induced increase in breathing frequency in KO mice and reduced MCh-induced seizures, via a direct or indirect mechanism. DORA improved oxygen saturation in KO mice with intermittent hypoxia. Daily administration of DORA to high-risk KO mice increased longevity. SIGNIFICANCE: High-risk KO mice have a unique cardiorespiratory phenotype that is characterized by progressive changes in five interdependent endpoints. Blocking of orexin receptors attenuates some of these endpoints and increases longevity, supporting the notion that windows of opportunity for intervention exist in this preclinical SUDEP model.


Assuntos
Apneia/genética , Bradicardia/genética , Epilepsia/genética , Hipóxia/genética , Canal de Potássio Kv1.1/genética , Morte Súbita Inesperada na Epilepsia , Animais , Apneia/fisiopatologia , Bradicardia/fisiopatologia , Epilepsia/fisiopatologia , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Região Hipotalâmica Lateral/metabolismo , Região Hipotalâmica Lateral/patologia , Hipóxia/fisiopatologia , Cloreto de Metacolina/toxicidade , Camundongos , Camundongos Knockout , Neurônios/metabolismo , Neurônios/patologia , Antagonistas dos Receptores de Orexina/farmacologia , Orexinas/metabolismo , Oximetria , Oxigênio , Sistema Nervoso Parassimpático/fisiopatologia , Parassimpatomiméticos/toxicidade , Taxa Respiratória/efeitos dos fármacos , Convulsões/induzido quimicamente
12.
Gene ; 731: 144341, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31935502

RESUMO

Hypoxia is one of the major challenges in aquaculture industry. Breeding of fish tolerant to hypoxia is an important task in genetic improvement of aquaculture species. The Asian seabass, Lates calcarifer, is an important foodfish species. We identified and characterized the hypoxia-inducible factor inhibitor (HIF1αn) gene in the Asian seabass. The full-length cDNA sequence of the HIF1αn was 3425 bp, with an ORF of 1065 bp, encoding 354 amino acids. The genomic sequence of the gene was 8667 bp in length, and contained eight exons and seven introns. Phylogenetic analysis of the gene in fish and tetrapods revealed that the HIF1αn in the Asian seabass was closely related to that of tilapia (Oreochromis niloticus). The HIF1αn was highly up-regulated in the gill, spleen and heart after 3.5-hours hypoxia treatment. We identified three SNPs in the third and fourth introns of the HIF1αn gene. The SNP (i.e. SNP 9332241 (C/T)) in the fourth intron was significantly (P < 0.01) associated with hypoxia tolerance. This SNP might be useful in selecting Asian seabass for improved tolerance to hypoxia. Our data also provide useful information for further detailed analysis of the function of the HIF1αn gene in hypoxia tolerance.


Assuntos
Adaptação Biológica/genética , Bass/genética , Hipóxia/genética , Oxigenases de Função Mista/genética , Animais , Bass/classificação , Bass/metabolismo , Clonagem Molecular , Feminino , Estudos de Associação Genética/veterinária , Masculino , Oxigenases de Função Mista/metabolismo , Perciformes/classificação , Perciformes/genética , Filogenia , Polimorfismo de Nucleotídeo Único , Proteínas Repressoras/genética , Homologia de Sequência , Proteínas de Peixe-Zebra/genética
13.
Arterioscler Thromb Vasc Biol ; 40(3): 523-533, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31893949

RESUMO

Peripheral artery disease, caused by chronic arterial occlusion of the lower extremities, affects over 200 million people worldwide. Peripheral artery disease can progress into critical limb ischemia (CLI), its more severe manifestation, which is associated with higher risk of limb amputation and cardiovascular death. Aiming to improve tissue perfusion, therapeutic angiogenesis held promise to improve ischemic limbs using delivery of growth factors but has not successfully translated into benefits for patients. Moreover, accumulating studies suggest that impaired downstream signaling of these growth factors (or angiogenic resistance) may significantly contribute to CLI, particularly under harsh environments, such as diabetes mellitus. Noncoding RNAs are essential regulators of gene expression that control a range of pathophysiologies relevant to CLI, including angiogenesis/arteriogenesis, hypoxia, inflammation, stem/progenitor cells, and diabetes mellitus. In this review, we summarize the role of noncoding RNAs, including microRNAs and long noncoding RNAs, as functional mediators or biomarkers in the pathophysiology of CLI. A better understanding of these ncRNAs in CLI may provide opportunities for new targets in the prevention, diagnosis, and therapeutic management of this disabling disease state.


Assuntos
Isquemia/genética , Doença Arterial Periférica/genética , RNA não Traduzido/genética , Animais , Estado Terminal , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatologia , Diabetes Mellitus/terapia , Regulação da Expressão Gênica , Hemodinâmica , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Hipóxia/terapia , Inflamação/genética , Inflamação/metabolismo , Inflamação/fisiopatologia , Inflamação/terapia , Isquemia/metabolismo , Isquemia/fisiopatologia , Isquemia/terapia , Neovascularização Fisiológica , Doença Arterial Periférica/metabolismo , Doença Arterial Periférica/fisiopatologia , Doença Arterial Periférica/terapia , Prognóstico , RNA não Traduzido/metabolismo , Fluxo Sanguíneo Regional , Fatores de Risco , Transdução de Sinais , Células-Tronco/metabolismo
14.
Int J Mol Med ; 45(2): 451-460, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31894303

RESUMO

Circular RNAs (circRNAs) serve important roles in cardiovascular diseases, including myocardial infarction. However, the mechanisms underlying the roles of circRNAs in cardiomyocyte death induced by anoxia/reoxygenation (A/R) are not fully understood. In the present study, the roles of circRNA_101237 and let­7a­5p in cardiomyocyte death induced by A/R injury were investigated. It was identified that circRNA_101237 was induced by A/R injury in a time­dependent manner and that circRNA_101237 knockdown protected cardiomyocytes from A/R­mediated apoptosis. Additional mechanistic studies revealed that circRNA_101237 served as a sponge for let­7a­5p, subsequently regulating insulin­like growth factor 2 mRNA­binding protein 3 (IGF2BP3)­dependent autophagy. IGF2BP3 downregulation decreased the levels of apoptosis and inhibited autophagy induced by A/R challenge in primary cardiomyocytes. These results identified circRNA_101237 as a novel circRNA that regulates cardiomyocyte death and autophagy, and demonstrated that the circRNA­101237/let­7a­5p/IGF2BP3 axis, which serves as a regulator of cardiomyocyte death, may be a potential therapeutic target for the management of cardiovascular diseases.


Assuntos
Hipóxia/genética , MicroRNAs/genética , Miócitos Cardíacos/patologia , RNA Circular/genética , Proteínas de Ligação a RNA/genética , Animais , Apoptose , Células Cultivadas , Regulação para Baixo , Regulação da Expressão Gênica , Hipóxia/patologia , Camundongos , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo
15.
Artigo em Inglês | MEDLINE | ID: mdl-31913656

RESUMO

Pulmonary hypertension (PH) is a multicellular and progressive disease with a high mortality rate. Among many cell types, hematopoietic stem cells (HSCs) are incriminated in the pathogenesis of PH. However, our understanding of the mechanisms that increase HSCs in blood and lungs of hypertensive animals or patients and the role played by HSCs in the pathogenesis of PH remains elusive. Studies suggest that glycolysis is critical for the survival and growth of HSCs. In various cell types from hypertensive lungs of animals and patients, glycolysis and the glucose-6-phosphate dehydrogenase (G6PD) activity are increased. Herein, we demonstrated in mice that chronic hypoxia increased HSCs (CD34+, CD117+, CD133+, CD34+/CD117+, and CD34+/CD133+) in bone marrow and blood and around hypertensive pulmonary arteries in a time-dependent manner. Intriguingly, we found fewer CD133+ cells in the bone marrow of C57BL/6 mice compared with Sv129J mice, and C57BL mice developed less severe chronic hypoxia-elicited PH and heart failure than Sv129J mice. Similarly, the numbers of CD34+ and CD117+ cells in blood of patients with pulmonary arterial hypertension (PAH) were higher (>3-fold) compared with healthy individuals. By allogeneic bone marrow transplantation, we found that GFP+ bone marrow cells infiltrated the lungs and accumulated around the pulmonary arteries in lungs of hypoxic mice, and these cells contributed to increased α-adrenergic receptor-mediated contraction of the pulmonary artery cultured in hypoxia. Inhibition of G6PD activity with (3ß,5α)-3,21-dihydroxypregnan-20-one, a novel and potent G6PD inhibitor, decreased HSCs in bone marrow, blood, and lungs of hypoxic mice and reduced α-agonist-induced contraction of the pulmonary artery and established hypoxia-induced PH. We did not observe CD133+ cells around the pulmonary arteries in the lungs of chronically hypoxic G6PD-deficient mice. Furthermore, knockdown of G6PD and inhibition of G6PD activity: 1) downregulated canonical and noncanonical Wnt and Fzd receptors genes; 2) upregulated Bmpr1a; 3) decreased Cxcl12, and 4) reduced HSC (CD117+ and CD133+) numbers. In all, our findings demonstrate unexpected function for bone marrow-derived HSCs in augmenting α-adrenergic receptor-mediated contraction of pulmonary arteries and remodeling of pulmonary arteries that contribute to increase pulmonary vascular resistance in PAH patients and hypoxic mice and suggest that G6PD, by regulating expression of genes in the WNT and BMPR signaling, contributed to increase and release of HSCs from the bone marrow in response to hypoxic stimuli.


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Hipertensão Pulmonar/fisiopatologia , Células-Tronco Pluripotentes/metabolismo , Artéria Pulmonar/fisiopatologia , Receptores Adrenérgicos alfa/metabolismo , Animais , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/metabolismo , Contagem de Células , Células Cultivadas , Quimiocina CXCL12/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucosefosfato Desidrogenase/antagonistas & inibidores , Glucosefosfato Desidrogenase/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Coração/fisiopatologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Hipertensão Pulmonar/etiologia , Hipóxia/sangue , Hipóxia/complicações , Hipóxia/genética , Pulmão/patologia , Pulmão/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células-Tronco Pluripotentes/efeitos dos fármacos , Artéria Pulmonar/efeitos dos fármacos , Via de Sinalização Wnt/genética
16.
Bull Exp Biol Med ; 168(3): 390-394, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31940130

RESUMO

The features of B16 melanoma progression in male C57BL/6 mice with initially high and low resistance to hypoxia were studied. To assess the resistance to hypoxia, the mice were placed in a low-pressure chamber at a simulated altitude of 10,000 m. One month after testing, B16 melanoma was inoculated to high- and low-resistant animals. In 19 days after melanoma transplantation, the severity of melanoma progression was assessed by morphological and immunofluorescent methods. The expression of vegf-a and hif-1a in the liver of melanomabearing and control mice was evaluated by real-time PCR. Tumor growth progression was more pronounced in low-resistant mice, which was seen from high weight of the primary tumor node, relative necrosis area, proliferation rates (mitotic index and number of Ki-67+ cells), and expression of vegf-a gene in the liver. In high-resistant to hypoxia animals, the number of caspase-3+ cells dying by apoptosis was higher. The data on more rapid melanoma progression in mice with low resistance to hypoxia should be considered during the search of new prognostic markers and methods for therapy of malignant neoplasms.


Assuntos
Hipóxia/metabolismo , Hipóxia/patologia , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Animais , Caspase 3/genética , Caspase 3/metabolismo , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Progressão da Doença , Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Melanoma Experimental/genética , Camundongos Endogâmicos C57BL , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Reação em Cadeia da Polimerase em Tempo Real , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
17.
BMC Genomics ; 21(1): 39, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931709

RESUMO

BACKGROUND: Hypoxia mediated pulmonary hypertension (HPH) is a lethal disease and lacks effective therapy. CircRNAs play significant roles in physiological process. Recently, circRNAs are found to be m6A-modified. The abundance of circRNAs was influenced by m6A. Furthermore, the significance of m6A circRNAs has not been elucidated in HPH yet. Here we aim to investigate the transcriptome-wide map of m6A circRNAs in HPH. RESULTS: Differentially expressed m6A abundance was detected in lungs of HPH rats. M6A abundance in circRNAs was significantly reduced in hypoxia in vitro. M6A circRNAs were mainly from protein-coding genes spanned single exons in control and HPH groups. Moreover, m6A influenced the circRNA-miRNA-mRNA co-expression network in hypoxia. M6A circXpo6 and m6A circTmtc3 were firstly identified to be downregulated in HPH. CONCLUSION: Our study firstly identified the transcriptome-wide map of m6A circRNAs in HPH. M6A can influence circRNA-miRNA-mRNA network. Furthermore, we firstly identified two HPH-associated m6A circRNAs: circXpo6 and circTmtc3. However, the clinical significance of m6A circRNAs for HPH should be further validated.


Assuntos
Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , RNA Circular , Transcriptoma , Animais , Biomarcadores , Suscetibilidade a Doenças , Regulação da Expressão Gênica , Hipertensão Pulmonar/fisiopatologia , MicroRNAs , RNA Mensageiro , Ratos
18.
Mol Genet Genomics ; 295(1): 31-46, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31414227

RESUMO

The buff-throated partridge (Tetraophasis szechenyii) is a hypoxia-tolerant bird living in an extremely inhospitable high-altitude environment, which has high ultraviolet (UV) radiation as well as a low oxygen supply when compared with low-altitude areas. To further understand the molecular genetic mechanisms of the high-altitude adaptation of the buff-throated partridges, we de novo assembled the complete genome of the buff-throated partridge. Comparative genomics revealed that positively selected hypoxia-related genes in the buff-throated partridge were distributed in the HIF-1 signaling pathway (map04066), response to hypoxia (GO:0001666), response to oxygen-containing compound (GO:1901700), ATP binding (GO:0005524), and angiogenesis (GO:0001525). Of these positively selected hypoxia-related genes, one positively selected gene (LONP1) had one buff-throated partridge-specific missense mutation which was classified as deleterious by PolyPhen-2. Moreover, positively selected genes in the buff-throated partridge were enriched in cellular response to DNA damage stimulus (corrected P value: 0.028006) and DNA repair (corrected P value: 0.044549), which was related to the increased exposure of the buff-throated partridge to UV radiation. Compared with other avian genomes, the buff-throated partridge showed expansion in genes associated with steroid hormone receptor activity and contractions in genes related to immune and olfactory perception. Furthermore, comparisons between the buff-throated partridge genome and red junglefowl genome revealed a conserved genome structure and provided strong evidence of the sibling relationship between Tetraophasis and Lophophorus. Our data and analysis contributed to the study of Phasianidae evolutionary history and provided new insights into the potential adaptation mechanisms to the high altitude employed by the buff-throated partridge.


Assuntos
Adaptação Fisiológica/genética , Aves/genética , Altitude , Animais , Evolução Biológica , Genoma/genética , Estudo de Associação Genômica Ampla/métodos , Hipóxia/genética , Masculino , Seleção Genética/genética
19.
Aquat Toxicol ; 218: 105359, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31765944

RESUMO

Carbohydrate metabolism switches from aerobic to anaerobic (glycolysis) to supply energy in response to acute hypoxic stress. Acute hypoxic stress with dissolved oxygen (DO) levels of 1.2 ±â€¯0.1 mg/L for 24 h and 12 h re-oxygenation was used to investigate the response of the anaerobic glycolytic pathway in Micropterus salmoides muscle. The results showed that the glucose concentration was significantly lower in muscle, while the lactic acid and pyruvic acid concentrations tended to increase during hypoxic stress. No significant difference was observed in muscle glycogen, and ATP content fluctuated significantly. The activities of gluconeogenesis-related enzymes were slightly elevated, such as phosphoenolpyruvate carboxykinase (PEPCK). The activities of the glycolytic enzymes increased after the induction of hypoxia, such as hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase (LDH). Curiously, phosphofructokinase (PFK) activity was significantly down-regulated within 4 h during hypoxia, although these effects were transient, and most indices returned to control levels after 12 h of re-oxygenation. Upregulated hif-1α, ampkα, hk, glut1, and ldh mRNA expression suggested that carbohydrate metabolism was reprogrammed under hypoxia. Lactate transport was regulated by miR-124-5p according to quantitative polymerase chain reaction and dual luciferase reporter assays. Our findings provide new insight into the molecular regulatory mechanism of hypoxia in Micropterus salmoides muscle.


Assuntos
Aclimatação/fisiologia , Bass/metabolismo , Hipóxia/metabolismo , Ácido Láctico/metabolismo , MicroRNAs/genética , Transportadores de Ácidos Monocarboxílicos/genética , Músculos/metabolismo , Simportadores/genética , Aclimatação/genética , Animais , Bass/genética , Metabolismo dos Carboidratos/genética , Metabolismo dos Carboidratos/fisiologia , Regulação da Expressão Gênica , Hipóxia/genética , Músculos/enzimologia , Oxigênio/metabolismo
20.
J Agric Food Chem ; 68(1): 193-205, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31826610

RESUMO

Gynostemma pentaphyllum possesses neuroprotective bioactivity. However, the effect of gypenosides on hypoxia-induced neural damage remains obscure. In this study, Gyp, the active fraction extracted from G. pentaphyllum and its bioactive compounds as well as the underlying molecular mechanisms were investigated. Eighteen dammarane-type saponins were isolated from Gyp. The absolute configurations of six unreported compounds (13-18) were assessed via electron capture detection (ECD) analyses. The results of cell viability assay showed that Gyp and its bioactive compounds (13-16 and 18) effectively protected PC12 cells from hypoxia injury. Gyp pretreatment also improved mice spatial memory impairment caused by hypoxia exposure. At the molecular level, Gyp and its bioactive compounds could activate the signaling pathways of ERK, Akt, and CREB in vitro and in vivo. In summary, Gyp and its bioactive compounds could prevent hypoxia-induced injury via ERK, Akt, and CREB signaling pathways.


Assuntos
Proteína de Ligação a CREB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gynostemma/química , Hipóxia/tratamento farmacológico , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Proteína de Ligação a CREB/genética , Sobrevivência Celular , MAP Quinases Reguladas por Sinal Extracelular/genética , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Células PC12 , Extratos Vegetais/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Saponinas/administração & dosagem
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