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1.
J Physiol ; 602(6): 1211-1225, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38381050

RESUMO

Gestational hypoxia adversely affects uterine artery function, increasing complications. However, an effective therapy remains unidentified. Here, we show in rodent uterine arteries that hypoxic pregnancy promotes hypertrophic remodelling, increases constrictor reactivity via protein kinase C signalling, and triggers compensatory dilatation via nitric oxide-dependent mechanisms and stimulation of large conductance Ca2+ -activated K+ -channels. Maternal in vivo oral treatment with the mitochondria-targeted antioxidant MitoQ in hypoxic pregnancy normalises uterine artery reactivity and prevents vascular remodelling. From days 6-20 of gestation (term ∼22 days), female Wistar rats were randomly assigned to normoxic or hypoxic (13-14% O2 ) pregnancy ± daily maternal MitoQ treatment (500 µm in drinking water). At 20 days of gestation, maternal, placental and fetal tissue was frozen to determine MitoQ uptake. The uterine arteries were harvested and, in one segment, constrictor and dilator reactivity was determined by wire myography. Another segment was fixed for unbiased stereological analysis of vessel morphology. Maternal administration of MitoQ in both normoxic and hypoxic pregnancy crossed the placenta and was present in all tissues analysed. Hypoxia increased uterine artery constrictor responses to norepinephrine, angiotensin II and the protein kinase C activator, phorbol 12,13-dibutyrate. Hypoxia enhanced dilator reactivity to sodium nitroprusside, the large conductance Ca2+ -activated K+ -channel activator NS1619 and ACh via increased nitric oxide-dependent mechanisms. Uterine arteries from hypoxic pregnancy showed increased wall thickness and MitoQ treatment in hypoxic pregnancy prevented all effects on uterine artery reactivity and remodelling. The data support mitochondria-targeted therapy against adverse changes in uterine artery structure and function in high-risk pregnancy. KEY POINTS: Dysfunction and remodelling of the uterine artery are strongly implicated in many pregnancy complications, including advanced maternal age, maternal hypertension of pregnancy, maternal obesity, gestational diabetes and pregnancy at high altitude. Such complications not only have immediate adverse effects on the growth of the fetus, but also they can also increase the risk of cardiovascular disease in the mother and offspring. Despite this, there is a significant unmet clinical need for therapeutics that treat uterine artery vascular dysfunction in adverse pregnancy. Here, we show in a rodent model of gestational hypoxia that in vivo oral treatment of the mitochondria-targeted antioxidant MitoQ protects against uterine artery vascular dysfunction and remodelling, supporting the use of mitochondria-targeted therapy against adverse changes in uterine artery structure and function in high-risk pregnancy.


Assuntos
Placenta , Artéria Uterina , Humanos , Ratos , Animais , Gravidez , Feminino , Placenta/metabolismo , Artéria Uterina/fisiologia , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Roedores , Óxido Nítrico/metabolismo , Ratos Wistar , Hipóxia , Proteína Quinase C/metabolismo , Mitocôndrias/metabolismo
2.
Cardiovasc Res ; 119(1): 136-154, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36082978

RESUMO

AIM: Myocardial infarction remains the leading cause of heart failure. The adult human heart lacks the capacity to undergo endogenous regeneration. New blood vessel growth is integral to regenerative medicine necessitating a comprehensive understanding of the pathways that regulate vascular regeneration. We sought to define the transcriptomic dynamics of coronary endothelial cells following ischaemic injuries in the developing and adult mouse and human heart and to identify new mechanistic insights and targets for cardiovascular regeneration. METHODS AND RESULTS: We carried out a comprehensive meta-analysis of integrated single-cell RNA-sequencing data of coronary vascular endothelial cells from the developing and adult mouse and human heart spanning healthy and acute and chronic ischaemic cardiac disease. We identified species-conserved gene regulatory pathways aligned to endogenous neovascularization. We annotated injury-associated temporal shifts of the endothelial transcriptome and validated four genes: VEGF-C, KLF4, EGR1, and ZFP36. Moreover, we showed that ZFP36 regulates human coronary endothelial cell proliferation and defined that VEGF-C administration in vivo enhances clonal expansion of the cardiac vasculature post-myocardial infarction. Finally, we constructed a coronary endothelial cell meta-atlas, CrescENDO, to empower future in-depth research to target pathways associated with coronary neovascularization. CONCLUSION: We present a high-resolution single-cell meta-atlas of healthy and injured coronary endothelial cells in the mouse and human heart, revealing a suite of novel targets with great potential to promote vascular regeneration, and providing a rich resource for therapeutic development.


Assuntos
Infarto do Miocárdio , Fator C de Crescimento do Endotélio Vascular , Adulto , Animais , Camundongos , Humanos , Fator C de Crescimento do Endotélio Vascular/metabolismo , Células Endoteliais/metabolismo , Miócitos Cardíacos/metabolismo , Coração/fisiologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Endotélio/metabolismo , Neovascularização Patológica/metabolismo , Regeneração
3.
Front Cardiovasc Med ; 9: 953211, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36299872

RESUMO

Background: Mechanisms contributing to tissue remodeling of the infarcted heart following cell-based therapy remain elusive. While cell-based interventions have the potential to influence the cardiac healing process, there is little direct evidence of preservation of functional myocardium. Aim: The aim of the study was to investigate tissue remodeling in the infarcted heart following human embryonic stem cell-derived endothelial cell product (hESC-ECP) therapy. Materials and methods: Following coronary artery ligation (CAL) to induce cardiac ischemia, we investigated infarct size at 1 day post-injection in media-injected controls (CALM, n = 11), hESC-ECP-injected mice (CALC, n = 10), and dead hESC-ECP-injected mice (CALD, n = 6); echocardiography-based functional outcomes 14 days post-injection in experimental (CALM, n = 13; CALC, n = 17) and SHAM surgical mice (n = 4); and mature infarct size (CALM and CALC, both n = 6). We investigated ligand-receptor interactions (LRIs) in hESC-ECP cell populations, incorporating a publicly available C57BL/6J mouse cardiomyocyte-free scRNAseq dataset with naive, 1 day, and 3 days post-CAL hearts. Results: Human embryonic stem cell-derived endothelial cell product injection reduces the infarct area (CALM: 54.5 ± 5.0%, CALC: 21.3 ± 4.9%), and end-diastolic (CALM: 87.8 ± 8.9 uL, CALC: 63.3 ± 2.7 uL) and end-systolic ventricular volume (CALM: 56.4 ± 9.3 uL, CALC: 33.7 ± 2.6 uL). LRI analyses indicate an alternative immunomodulatory effect mediated via viable hESC-ECP-resident signaling. Conclusion: Delivery of the live hESC-ECP following CAL modulates the wound healing response during acute pathological remodeling, reducing infarct area, and preserving functional myocardium in this relatively acute model. Potential intrinsic myocardial cellular/hESC-ECP interactions indicate that discreet immunomodulation could provide novel therapeutic avenues to improve cardiac outcomes following myocardial infarction.

4.
Cardiovasc Res ; 118(11): 2519-2534, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34528097

RESUMO

AIMS: Endothelial cell (EC) dysfunction drives the initiation and pathogenesis of pulmonary arterial hypertension (PAH). We aimed to characterize EC dynamics in PAH at single-cell resolution. METHODS AND RESULTS: We carried out single-cell RNA sequencing (scRNA-seq) of lung ECs isolated from an EC lineage-tracing mouse model in Control and SU5416/hypoxia-induced PAH conditions. EC populations corresponding to distinct lung vessel types, including two discrete capillary populations, were identified in both Control and PAH mice. Differential gene expression analysis revealed global PAH-induced EC changes that were confirmed by bulk RNA-seq. This included upregulation of the major histocompatibility complex class II pathway, supporting a role for ECs in the inflammatory response in PAH. We also identified a PAH response specific to the second capillary EC population including upregulation of genes involved in cell death, cell motility, and angiogenesis. Interestingly, four genes with genetic variants associated with PAH were dysregulated in mouse ECs in PAH. To compare relevance across PAH models and species, we performed a detailed analysis of EC heterogeneity and response to PAH in rats and humans through whole-lung PAH scRNA-seq datasets, revealing that 51% of up-regulated mouse genes were also up-regulated in rat or human PAH. We identified promising new candidates to target endothelial dysfunction including CD74, the knockdown of which regulates EC proliferation and barrier integrity in vitro. Finally, with an in silico cell ordering approach, we identified zonation-dependent changes across the arteriovenous axis in mouse PAH and showed upregulation of the Serine/threonine-protein kinase Sgk1 at the junction between the macro- and microvasculature. CONCLUSION: This study uncovers PAH-induced EC transcriptomic changes at a high resolution, revealing novel targets for potential therapeutic candidate development.


Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Animais , Células Endoteliais/metabolismo , Hipertensão Pulmonar Primária Familiar/metabolismo , Humanos , Camundongos , Hipertensão Arterial Pulmonar/genética , Artéria Pulmonar , Ratos , Análise de Sequência de RNA
6.
Am J Physiol Endocrinol Metab ; 321(4): E530-E542, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34459219

RESUMO

Fetal growth restriction (FGR) is associated with decreased insulin secretory capacity and decreased insulin sensitivity in muscle in adulthood. We investigated whether intra-amniotic IGF-I treatment in late gestation mitigated the adverse effects of FGR on the endocrine pancreas and skeletal muscle at 18 mo of age. Singleton-bearing ewes underwent uterine artery embolization between 103 and 107 days of gestational age, followed by 5 once-weekly intra-amniotic injections of 360-µg IGF-I (FGRI) or saline (FGRS) and were compared with an unmanipulated control group (CON). We measured offspring pancreatic endocrine cell mass and pancreatic and skeletal muscle mRNA expression at 18 mo of age (n = 7-9/sex/group). Total α-cell mass was increased ∼225% in FGRI males versus CON and FGRS males, whereas ß-cell mass was not different between groups of either sex. Pancreatic mitochondria-related mRNA expression was increased in FGRS females versus CON (NRF1, MTATP6, UCP2), and FGRS males versus CON (TFAM, NRF1, UCP2) but was largely unchanged in FGRI males versus CON. In skeletal muscle, mitochondria-related mRNA expression was decreased in FGRS females versus CON (PPARGC1A, TFAM, NRF1, UCP2, MTATP6), FGRS males versus CON (NRF1 and UCP2), and FGRI females versus CON (TFAM and UCP2), with only MTATP6 expression decreased in FGRI males versus CON. Although the window during which IGF-I treatment was delivered was limited to the final 5 wk of gestation, IGF-I therapy of FGR altered the endocrine pancreas and skeletal muscle in a sex-specific manner in young adulthood.NEW & NOTEWORTHY Fetal growth restriction (FGR) is associated with compromised metabolic function throughout adulthood. Here, we explored the long-term effects of fetal IGF-I therapy on the adult pancreas and skeletal muscle. This is the first study demonstrating that IGF-I therapy of FGR has sex-specific long-term effects at both the tissue and molecular level on metabolically active tissues in adult sheep.


Assuntos
Líquido Amniótico/metabolismo , Retardo do Crescimento Fetal/tratamento farmacológico , Fator de Crescimento Insulin-Like I/administração & dosagem , Células Secretoras de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Caracteres Sexuais , Animais , Feminino , Retardo do Crescimento Fetal/metabolismo , Retardo do Crescimento Fetal/patologia , Terapias Fetais , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Masculino , Músculo Esquelético/metabolismo , Gravidez , Ovinos
8.
FASEB J ; 35(5): e21446, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33788974

RESUMO

Mitochondria-derived oxidative stress during fetal development increases cardiovascular risk in adult offspring of pregnancies complicated by chronic fetal hypoxia. We investigated the efficacy of the mitochondria-targeted antioxidant MitoQ in preventing cardiovascular dysfunction in adult rat offspring exposed to gestational hypoxia, integrating functional experiments in vivo, with those at the isolated organ and molecular levels. Rats were randomized to normoxic or hypoxic (13%-14% O2 ) pregnancy ± MitoQ (500 µM day-1 ) in the maternal drinking water. At 4 months of age, one cohort of male offspring was chronically instrumented with vascular catheters and flow probes to test in vivo cardiovascular function. In a second cohort, the heart was isolated and mounted onto a Langendorff preparation. To establish mechanisms linking gestational hypoxia with cardiovascular dysfunction and protection by MitoQ, we quantified the expression of antioxidant system, ß-adrenergic signaling, and calcium handling genes in the fetus and adult, in frozen tissues from a third cohort. Maternal MitoQ in hypoxic pregnancy protected offspring against increased α1 -adrenergic reactivity of the cardiovascular system, enhanced reactive hyperemia in peripheral vascular beds, and sympathetic dominance, hypercontractility and diastolic dysfunction in the heart. Inhibition of Nfe2l2-mediated oxidative stress in the fetal heart and preservation of calcium regulatory responses in the hearts of fetal and adult offspring link molecular mechanisms to the protective actions of MitoQ treatment of hypoxic pregnancy. Therefore, these data show the efficacy of MitoQ in buffering mitochondrial stress through NADPH-induced oxidative damage and the prevention of programmed cardiovascular disease in adult offspring of hypoxic pregnancy.


Assuntos
Antioxidantes/farmacologia , Doenças Cardiovasculares/prevenção & controle , Hipóxia Fetal/complicações , Mitocôndrias/metabolismo , Estresse Oxidativo , Efeitos Tardios da Exposição Pré-Natal/prevenção & controle , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/patologia , Feminino , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos Wistar
9.
Int J Mol Sci ; 22(2)2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33478078

RESUMO

Long non-coding RNAs (lncRNAs) have structural and functional roles in development and disease. We have previously shown that the LINC00961/SPAAR (small regulatory polypeptide of amino acid response) locus regulates endothelial cell function, and that both the lncRNA and micropeptide counter-regulate angiogenesis. To assess human cardiac cell SPAAR expression, we mined a publicly available scRNSeq dataset and confirmed LINC00961 locus expression and hypoxic response in a murine endothelial cell line. We investigated post-natal growth and development, basal cardiac function, the cardiac functional response, and tissue-specific response to myocardial infarction. To investigate the influence of the LINC00961/SPAAR locus on longitudinal growth, cardiac function, and response to myocardial infarction, we used a novel CRISPR/Cas9 locus knockout mouse line. Data mining suggested that SPAAR is predominantly expressed in human cardiac endothelial cells and fibroblasts, while murine LINC00961 expression is hypoxia-responsive in mouse endothelial cells. LINC00961-/- mice displayed a sex-specific delay in longitudinal growth and development, smaller left ventricular systolic and diastolic areas and volumes, and greater risk area following myocardial infarction compared with wildtype littermates. These data suggest the LINC00961/SPAAR locus contributes to cardiac endothelial cell and fibroblast function and hypoxic response, growth and development, and basal cardiovascular function in adulthood.


Assuntos
Crescimento e Desenvolvimento/genética , Coração/fisiologia , Infarto do Miocárdio/fisiopatologia , Peptídeos/fisiologia , Animais , Células Endoteliais/fisiologia , Feminino , Loci Gênicos/fisiologia , Coração/crescimento & desenvolvimento , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infarto do Miocárdio/genética , Miocárdio/metabolismo , Neovascularização Fisiológica/genética , Peptídeos/genética
10.
JACC Basic Transl Sci ; 5(7): 665-681, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32760855

RESUMO

In ST-segment elevation myocardial infarction of both patients and mice, there was a decline in blood eosinophil count, with activated eosinophils recruited to the infarct zone. Eosinophil deficiency resulted in attenuated anti-inflammatory macrophage polarization, enhanced myocardial inflammation, increased scar size, and deterioration of myocardial structure and function. Adverse cardiac remodeling in the setting of eosinophil deficiency was prevented by interleukin-4 therapy.

11.
Am J Physiol Endocrinol Metab ; 318(4): E568-E578, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32101029

RESUMO

Fetal growth restriction (FGR) is associated with compromised growth and metabolic function throughout life. Intrauterine therapy of FGR with intra-amniotic insulin-like growth factor-1 (IGF1) enhances fetal growth and alters perinatal metabolism and growth in a sex-specific manner, but the adult effects are unknown. We investigated the effects of intra-amniotic IGF1 treatment of FGR on adult growth and body composition, adrenergic sensitivity, and glucose-insulin axis regulation. Placental embolization-induced FGR was treated with four weekly doses of 360 µg intra-amniotic IGF1 (FGRI) or saline (FGRS). Offspring were raised to adulthood (18 mo: FGRI, n = 12 females, 12 males; FGRS, n = 13 females, 10 males) alongside offspring from unembolized and untreated sheep (CON; n = 12 females, 21 males). FGRI females had increased relative lean mass compared with CON but not FGRS (P < 0.05; 70.6 ± 8.2% vs. 61.4 ± 8.2% vs. 67.6 ± 8.2%), decreased abdominal adipose compared with CON and FGRS (P < 0.05; 43.7 ± 1.2% vs. 49.3 ± 0.9% vs. 48.5 ± 1.0%), increased glucose utilization compared with FGRS but not CON (P < 0.05; 9.6 ± 1.0 vs. 6.0 ± 0.9 vs. 7.6 ± 0.9 mg·kg-1·min-1), and increased ß-hydroxybutyric acid:nonesterified fatty acid ratio in response to adrenaline compared with CON and FGRS (P < 0.05; 3.9 ± 1.4 vs. 1.1 ± 1.4 vs. 1.8 ± 1.4). FGRS males were smaller and lighter compared with CON but not FGRI (P < 0.05; 86.8 ± 6.3 vs. 93.5 ± 6.1 vs. 90.7 ± 6.3 kg), with increased peak glucose concentration (10%) in response to a glucose load but few other differences. These effects of intra-amniotic IGF1 therapy on adult body composition, glucose-insulin axis function, and adrenergic sensitivity could indicate improved metabolic regulation during young adulthood in female FGR sheep.


Assuntos
Composição Corporal/efeitos dos fármacos , Retardo do Crescimento Fetal/tratamento farmacológico , Fator de Crescimento Insulin-Like I/uso terapêutico , Metabolismo/efeitos dos fármacos , Ácido 3-Hidroxibutírico/metabolismo , Absorciometria de Fóton , Animais , Epinefrina/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Glucose/metabolismo , Injeções , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/administração & dosagem , Gravidez , Caracteres Sexuais , Ovinos , Embolização da Artéria Uterina , Útero
12.
Cardiovasc Res ; 116(12): 1981-1994, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31990292

RESUMO

AIMS: Long non-coding RNAs (lncRNAs) play functional roles in physiology and disease, yet understanding of their contribution to endothelial cell (EC) function is incomplete. We identified lncRNAs regulated during EC differentiation and investigated the role of LINC00961 and its encoded micropeptide, small regulatory polypeptide of amino acid response (SPAAR), in EC function. METHODS AND RESULTS: Deep sequencing of human embryonic stem cell differentiation to ECs was combined with Encyclopedia of DNA Elements (ENCODE) RNA-seq data from vascular cells, identifying 278 endothelial enriched genes, including 6 lncRNAs. Expression of LINC00961, first annotated as an lncRNA but reassigned as a protein-coding gene for the SPAAR micropeptide, was increased during the differentiation and was EC enriched. LINC00961 transcript depletion significantly reduced EC adhesion, tube formation, migration, proliferation, and barrier integrity in primary ECs. Overexpression of the SPAAR open reading frame increased tubule formation; however, overexpression of the full-length transcript did not, despite production of SPAAR. Furthermore, overexpression of an ATG mutant of the full-length transcript reduced network formation, suggesting a bona fide non-coding RNA function of the transcript with opposing effects to SPAAR. As the LINC00961 locus is conserved in mouse, we generated an LINC00961 locus knockout (KO) mouse that underwent hind limb ischaemia (HLI) to investigate the angiogenic role of this locus in vivo. In agreement with in vitro data, KO animals had a reduced capillary density in the ischaemic adductor muscle after 7 days. Finally, to characterize LINC00961 and SPAAR independent functions in ECs, we performed pull-downs of both molecules and identified protein-binding partners. LINC00961 RNA binds the G-actin sequestering protein thymosin beta-4x (Tß4) and Tß4 depletion phenocopied the overexpression of the ATG mutant. SPAAR binding partners included the actin-binding protein, SYNE1. CONCLUSION: The LINC00961 locus regulates EC function in vitro and in vivo. The gene produces two molecules with opposing effects on angiogenesis: SPAAR and LINC00961.


Assuntos
Células Endoteliais/metabolismo , Membro Posterior/irrigação sanguínea , Isquemia/metabolismo , Neovascularização Fisiológica , Peptídeos/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Células-Tronco Embrionárias Humanas/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Isquemia/genética , Isquemia/fisiopatologia , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Peptídeos/genética , Ligação Proteica , RNA Longo não Codificante/genética , RNA-Seq , Transdução de Sinais , Timosina/genética , Timosina/metabolismo , Transcriptoma
13.
FASEB J ; 33(6): 7758-7766, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30888848

RESUMO

Chronic fetal hypoxia is a common complication observed in human pregnancy, impacting pregnancies across global contexts. Exposure to chronic intrauterine hypoxia has major short- and long-term consequences for offspring health. However, the impact of chronic gestational hypoxia on female reproductive system development is unknown. We aimed to understand the impact of exposure to chronic fetal hypoxia on the developing female reproductive system. Wistar rat dams underwent normoxia (21%) or hypoxia (13%) during pregnancy. Postnatally, all female offspring were maintained in normoxic conditions into early adulthood. Female rats exposed to chronic gestational hypoxia (13%) during their intrauterine development had decreased ovarian primordial follicular reserve compared to controls (P < 0.05). Adult females who had been exposed to chronic fetal hypoxia had significantly reduced somatic ovarian telomere length (P < 0.05) and reduced ovarian protein expression of KU70, a critical component of the DNA-activated protein kinase repair complex (P < 0.01). Gene expression of NADPH oxidase 2-mediated oxidative stress markers was increased (P < 0.05). Exposure to chronic hypoxia during fetal development leads to accelerated aging of the somatic ovary and decreased ovarian reserve in adulthood. Ovarian aging is highly sensitive to gestational hypoxia, with implications for future fertility in next-generation offspring of high-risk pregnancies.-Aiken, C. E., Tarry-Adkins, J. L., Spiroski, A.-M., Nuzzo, A. M., Ashmore, T. J., Rolfo, A., Sutherland, M. J., Camm, E. J., Giussani, D. A., Ozanne, S. E. Chronic gestational hypoxia accelerates ovarian aging and lowers ovarian reserve in next-generation adult rats.


Assuntos
Hipóxia/fisiopatologia , Reserva Ovariana , Ovário/fisiopatologia , Envelhecimento , Animais , Doença Crônica , Feminino , Expressão Gênica , Gravidez , Ratos , Ratos Wistar
14.
J Physiol ; 597(9): 2391-2401, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30791124

RESUMO

KEY POINTS: Exposure to chronic hypoxia during gestation influences long-term health and development, including reproductive capacity, across generations. If the peri-conceptual environment in the developing oviduct is affected by gestational hypoxia, then this could have implications for later fertility and the health of future generations. In the present study, we show that the oviducts of female rats exposed to chronic hypoxia in utero have reduced telomere length, decreased mitochondrial DNA biogenesis and increased oxidative stress The results of the present study show that exposure to chronic gestational hypoxia leads to accelerated ageing of the oviduct in early adulthood and they help us understand how exposure to hypoxia during development could influence reproductive health across generations. ABSTRACT: Exposure to chronic hypoxia during fetal development has important effects on immediate and long-term outcomes in offspring. Adverse impacts in adult offspring include impairment of cardiovascular function, metabolic derangement and accelerated ovarian ageing. However, it is not known whether other aspects of the female reproductive system may be similarly affected. In the present study, we examined the impact of chronic gestational hypoxia on the developing oviduct. Wistar rat dams were randomized to either normoxia (21%) or hypoxia (13%) from day 6 post-mating until delivery. Post-delivery female offspring were maintained in normoxia until 4 months of age. Oviductal gene expression was assayed at the RNA (quantitative RT-PCR) and protein (western blotting) levels. Oviductal telomere length was assayed using Southern blotting. Oviductal telomere length was reduced in the gestational hypoxia-exposed animals compared to normoxic controls (P < 0.01). This was associated with a specific post-transcriptional reduction in the KU70 subunit of DNA-pk in the gestational hypoxia-exposed group (P < 0.05). Gestational hypoxia-exposed oviducts also showed evidence of decreased mitochondrial DNA biogenesis, reduced mtDNA copy number (P < 0.05) and reduced gene expression of Tfam (P < 0.05) and Pgc1α (P < 0.05). In the hypoxia-exposed oviducts, there was upregulation of mitochondrial-specific anti-oxidant defence enzymes (MnSOD; P < 0.01). Exposure to chronic gestational hypoxia leads to accelerated ageing of the oviduct in adulthood. The oviduct plays a central role in early development as the site of gamete transport, syngamy, and early development; hence, accelerated ageing of the oviductal environment could have important implications for fertility and the health of future generations.


Assuntos
Hipóxia Fetal/fisiopatologia , Infertilidade/etiologia , Oviductos/metabolismo , Animais , DNA Mitocondrial/genética , Epigênese Genética , Feminino , Fertilidade , Hipóxia Fetal/complicações , Hipóxia Fetal/genética , Hipóxia Fetal/metabolismo , Oviductos/patologia , Estresse Oxidativo , Ratos , Ratos Wistar , Homeostase do Telômero , Transcriptoma
15.
Am J Pathol ; 188(12): 2704-2716, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30248337

RESUMO

The placenta responds to adverse environmental conditions by adapting its capacity for substrate transfer to maintain fetal growth and development. Early-onset hypoxia effects on placental morphology and activation of the unfolded protein response (UPR) were determined using an established rat model in which fetal growth restriction is minimized. We further established whether maternal treatment with a mitochondria-targeted antioxidant (MitoQ) confers protection during hypoxic pregnancy. Wistar dams were exposed to normoxia (21% O2) or hypoxia (13% to 14% O2) from days 6 to 20 of pregnancy with and without MitoQ treatment (500 µmol/L in drinking water). On day 20, animals were euthanized and weighed, and the placentas from male fetuses were processed for stereology to assess morphology. UPR activation in additional cohorts of frozen placentas was determined with Western blot analysis. Neither hypoxic pregnancy nor MitoQ treatment affected fetal growth. Hypoxia increased placental volume and the fetal capillary surface area and induced mitochondrial stress as well as the UPR, as evidenced by glucose-regulated protein 78 and activating transcription factor (ATF) 4 protein up-regulation. MitoQ treatment in hypoxic pregnancy increased placental maternal blood space surface area and volume and prevented the activation of mitochondrial stress and the ATF4 pathway. The data suggest that mitochondria-targeted antioxidants may be beneficial in complicated pregnancy via mechanisms protecting against placental stress and enhancing placental perfusion.


Assuntos
Adaptação Fisiológica , Antioxidantes/farmacologia , Retardo do Crescimento Fetal/tratamento farmacológico , Hipóxia/fisiopatologia , Mitocôndrias/efeitos dos fármacos , Placenta/fisiologia , Animais , Feminino , Retardo do Crescimento Fetal/metabolismo , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Placenta/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Resposta a Proteínas não Dobradas
16.
J Mol Cell Cardiol ; 123: 88-91, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30118790

RESUMO

Ischemia-reperfusion (IR) injury occurs when blood supply to an organ is disrupted and then restored, and underlies many disorders, notably myocardial infarction and stroke. While reperfusion of ischemic tissue is essential for survival, it also initiates cell death through generation of mitochondrial reactive oxygen species (ROS). Recent work has revealed a novel pathway underlying ROS production at reperfusion in vivo in which the accumulation of succinate during ischemia and its subsequent rapid oxidation at reperfusion drives ROS production at complex I by reverse electron transport (RET). Pharmacologically inhibiting ischemic succinate accumulation, or slowing succinate metabolism at reperfusion, have been shown to be cardioprotective against IR injury. Here, we determined whether ischemic preconditioning (IPC) contributes to cardioprotection by altering kinetics of succinate accumulation and oxidation during IR. Mice were subjected to a 30-minute occlusion of the left anterior descending coronary artery followed by reperfusion, with or without a protective IPC protocol prior to sustained ischemia. We found that IPC had no effect on ischemic succinate accumulation with both control and IPC mice having profound increases in succinate compared to normoxia. Furthermore, after only 1-minute reperfusion succinate was rapidly metabolised returning to near pre-ischemic levels in both groups. We conclude that IPC does not affect ischemic succinate accumulation, or its oxidation at reperfusion.


Assuntos
Precondicionamento Isquêmico Miocárdico , Traumatismo por Reperfusão Miocárdica/metabolismo , Oxirredução , Ácido Succínico/metabolismo , Análise de Variância , Animais , Modelos Animais de Doenças , Metabolismo Energético , Masculino , Metaboloma , Metabolômica/métodos , Camundongos , Mitocôndrias/metabolismo , Traumatismo por Reperfusão Miocárdica/etiologia , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Miocárdio/patologia , Espécies Reativas de Oxigênio/metabolismo
17.
J Stroke Cerebrovasc Dis ; 24(6): 1153-62, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25847304

RESUMO

BACKGROUND: Stroke is the third most common cause of death and a major cause of chronic disability in New Zealand. Linked to risk factors that develop across the life-course, stroke is considered to be largely preventable. This study assessed the awareness of stroke risk, symptoms, detection, and prevention behaviors in an urban New Zealand population. METHODS: Demographics, stroke risk factors awareness, symptoms, responsiveness, and prevention behaviors were evaluated using a structured oral questionnaire. Binomial logistic regression analyses were used to identify predictors of stroke literacy. RESULTS: Although personal experience of stroke increased awareness of symptoms and their likeliness to indicate the need for urgent medical attention, only 42.7% of the respondents (n = 850) identified stroke as involving both blood and the brain. Educational attainment at or above a trade certificate, apprenticeship, or diploma increased the awareness of stroke symptoms compared with those with no formal educational attainment. Pacific Island respondents were less likely than New Zealand Europeans to identify a number of stroke risk factors. Maori, Pacific Island, and Asian respondents were less likely to identify symptoms of stroke and indicate the need for urgent medical attention. CONCLUSIONS: The variability in stroke awareness and knowledge may suggest the need to enhance stroke-related health literacy that facilitates understanding of risk and of factors that reduce morbidity and mortality after stroke in people of Maori and Pacific Island descent and in those with lower educational attainment or socioeconomic status. It is therefore important that stroke awareness campaigns include tailored components for target audiences.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Letramento em Saúde , Acidente Vascular Cerebral , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Fatores de Risco , População Urbana , Adulto Jovem
18.
Semin Fetal Neonatal Med ; 18(3): 118-123, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23639574

RESUMO

Optimal fetal growth is important for a healthy pregnancy outcome and also for lifelong health. Fetal growth is largely regulated by fetal nutrition, and mediated via the maternal and fetal glucose/insulin/insulin-like growth factor axes. Fetal nutrition may reflect maternal nutrition, but abnormalities of placental function can also affect fetal growth, as the placenta plays a key intermediary role in nutritional signalling between mother and fetus. Fetal nutrition also impacts on the development of key fetal endocrine systems such as the glucose-insulin and insulin-like growth factor axes. This is likely to contribute to the link between both fetal growth restriction and fetal overgrowth, and increased risks of obesity and impaired glucose tolerance in later life. This review focuses on the associations between maternal and fetal nutrition, fetal growth and later disease risk, with particular emphasis on the role of insulin-like growth factors and the importance of the periconceptional period.

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