scholarly journals Accelerated tumor growth under intermittent hypoxia is associated with hypoxia-inducible factor-1-dependent adaptive responses to hypoxia

Oncotarget ◽  
2017 ◽  
Vol 8 (37) ◽  
pp. 61592-61603 ◽  
Author(s):  
Dae Wui Yoon ◽  
Daeho So ◽  
Sra Min ◽  
Jiyoung Kim ◽  
Mingyu Lee ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Intermittent Hypoxia ◽  
Hypoxia Inducible Factor ◽  
Adaptive Responses ◽  
Hypoxia Inducible Factor 1

Regulation of Oxygen Homeostasis by Hypoxia-Inducible Factor 1

Physiology ◽  
2009 ◽  
Vol 24 (2) ◽  
pp. 97-106 ◽  
Author(s):  
Gregg L. Semenza
Keyword(s):  
Transcription Factor ◽  
Growth Factor ◽  
Intermittent Hypoxia ◽  
Hypoxia Inducible Factor ◽  
Metabolic Reprogramming ◽  
Systemic Hypertension ◽  
Adaptive Responses ◽  
Hypoxia Inducible Factor 1 ◽  
Oxygen Homeostasis ◽  
Genes Encoding

Metazoan organisms are dependent on a continuous supply of O2 for survival. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that regulates oxygen homeostasis and plays key roles in development, physiology, and disease. HIF-1 activity is induced in response to continuous hypoxia, intermittent hypoxia, growth factor stimulation, and Ca2+ signaling. HIF-1 mediates adaptive responses to hypoxia, including erythropoiesis, angiogenesis, and metabolic reprogramming. In each case, HIF-1 regulates the expression of multiple genes encoding key components of the response pathway. HIF-1 also mediates maladaptive responses to chronic continuous and intermittent hypoxia, which underlie the development of pulmonary and systemic hypertension, respectively.

scholarly journals Hypoxia-inducible factor-1 modulates gene expression in solid tumors and influences both angiogenesis and tumor growth

1997 ◽  
Vol 94 (15) ◽  
pp. 8104-8109 ◽  
Author(s):  
P. H. Maxwell ◽  
G. U. Dachs ◽  
J. M. Gleadle ◽  
L. G. Nicholls ◽  
A. L. Harris ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Growth ◽  
Solid Tumors ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1

scholarly journals Adaptive and Maladaptive Cardiorespiratory Responses to Continuous and Intermittent Hypoxia Mediated by Hypoxia-Inducible Factors 1 and 2

2012 ◽  
Vol 92 (3) ◽  
pp. 967-1003 ◽  
Author(s):  
Nanduri R. Prabhakar ◽  
Gregg L. Semenza
Keyword(s):  
Transcriptional Activation ◽  
Intermittent Hypoxia ◽  
Hypoxia Inducible Factor ◽  
Metabolic Reprogramming ◽  
Hypoxia Inducible Factor 1 ◽  
Oxygen Homeostasis ◽  
Physiological Adaptations ◽  
Prolyl Hydroxylation ◽  
Insight Into ◽  
Subsequent Identification

Hypoxia is a fundamental stimulus that impacts cells, tissues, organs, and physiological systems. The discovery of hypoxia-inducible factor-1 (HIF-1) and subsequent identification of other members of the HIF family of transcriptional activators has provided insight into the molecular underpinnings of oxygen homeostasis. This review focuses on the mechanisms of HIF activation and their roles in physiological and pathophysiological responses to hypoxia, with an emphasis on the cardiorespiratory systems. HIFs are heterodimers comprised of an O2-regulated HIF-1α or HIF-2α subunit and a constitutively expressed HIF-1β subunit. Induction of HIF activity under conditions of reduced O2availability requires stabilization of HIF-1α and HIF-2α due to reduced prolyl hydroxylation, dimerization with HIF-1β, and interaction with coactivators due to decreased asparaginyl hydroxylation. Stimuli other than hypoxia, such as nitric oxide and reactive oxygen species, can also activate HIFs. HIF-1 and HIF-2 are essential for acute O2sensing by the carotid body, and their coordinated transcriptional activation is critical for physiological adaptations to chronic hypoxia including erythropoiesis, vascularization, metabolic reprogramming, and ventilatory acclimatization. In contrast, intermittent hypoxia, which occurs in association with sleep-disordered breathing, results in an imbalance between HIF-1α and HIF-2α that causes oxidative stress, leading to cardiorespiratory pathology.

scholarly journals Intermittent hypoxia enhances the expression of HIF1A by increasing the quantity and catalytic activity of KDM4A-C and demethylating H3K9me3 at the HIF1A locus

2021 ◽  
Author(s):  
Chloe-Anne Martinez ◽  
Neha Bal ◽  
Peter A Cistulli ◽  
Kristina M Cook
Keyword(s):  
Intermittent Hypoxia ◽  
Target Genes ◽  
Chronic Hypoxia ◽  
Oxygen Sensing ◽  
Biological Effects ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1 ◽  
Sensing Systems ◽  
Cellular Oxygen ◽  
Fine Tune

Cellular oxygen-sensing pathways are primarily regulated by hypoxia inducible factor-1 (HIF-1) in chronic hypoxia and are well studied. Intermittent hypoxia also occurs in many pathological conditions, yet little is known about its biological effects. In this study, we investigated how two proposed cellular oxygen sensing systems, HIF-1 and KDM4A-C, respond to cells exposed to intermittent hypoxia and compared to chronic hypoxia. We found that intermittent hypoxia increases HIF-1 activity through a pathway distinct from chronic hypoxia, involving the KDM4A, -B and -C histone lysine demethylases. Intermittent hypoxia increases the quantity and activity of KDM4A-C resulting in a decrease in H3K9 methylation. This contrasts with chronic hypoxia, which decreases KDM4A-C activity, leading to hypermethylation of H3K9. Demethylation of histones bound to the HIF1A gene in intermittent hypoxia increases HIF1A mRNA expression, which has the downstream effect of increasing overall HIF-1 activity and expression of HIF target genes. This study highlights how multiple oxygen-sensing pathways can interact to regulate and fine tune the cellular hypoxic response depending on the period and length of hypoxia.

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