Mechanisms and triggers of adaptation to hypoxia

2021 ◽  
Vol 19 (3) ◽  
pp. 269-280
Author(s):  
Andrey V. Lyubimov ◽  
Dmitriy V. Cherkashin ◽  
Semen V. Efimov ◽  
Andrey E. Alanichev ◽  
Valeriy S. Ivanov ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Side Effects ◽  
Partial Pressure ◽  
Molecular Mechanisms ◽  
Oxygen Metabolism ◽  
External Factors ◽  
Iron Chelators ◽  
Adaptation To Hypoxia ◽  
Partial Pressure Of Oxygen ◽  
Prophylactic Use

It is believed that hypoxia-induced factor (HIF1) is the key mediator of oxygen metabolism. It was first identified as a transcription factor activated in cells and tissues by lowering the partial pressure of oxygen (O2). The HIF1 activator spectrum includes both external factors hypoxia, psycho-emotional stress and in ternal factors and varies from hormones to iron chelators. This review is dedicated to the molecular mechanisms of HIF1 activation, some of its natural activators HIF1, the potential for which is due to the low level of toxicity and the reduced likelihood of undesirable side effects. In turn, this opens up new options to treat diseases associated with local and general ischemia and hypoxia, the possibilities of their prophylactic use for researchers and clinicians in order to reduce the degree of damage in the event of an unforeseen condition of acute injurious to organs and tissues by hypoxia and reperfusion after it.

scholarly journals Acquired Glucocorticoid Resistance Due to Homologous Glucocorticoid Receptor Downregulation: A Modern Look at an Age-Old Problem

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2529
Author(s):  
Lee-Maine L. Spies ◽  
Nicolette J. D. Verhoog ◽  
Ann Louw
Keyword(s):  
Transcription Factor ◽  
Side Effects ◽  
Pharmaceutical Industry ◽  
Glucocorticoid Receptor ◽  
Steroid Hormones ◽  
Molecular Mechanisms ◽  
Protein Levels ◽  
Current Review ◽  
Role Players ◽  
Receptor Conformation

For over 70 years, the unique anti-inflammatory properties of glucocorticoids (GCs), which mediate their effects via the ligand-activated transcription factor, the glucocorticoid receptor alpha (GRα), have allowed for the use of these steroid hormones in the treatment of various autoimmune and inflammatory-linked diseases. However, aside from the onset of severe side-effects, chronic GC therapy often leads to the ligand-mediated downregulation of the GRα which, in turn, leads to a decrease in GC sensitivity, and effectively, the development of acquired GC resistance. Although the ligand-mediated downregulation of GRα is well documented, the precise factors which influence this process are not well understood and, thus, the development of an acquired GC resistance presents an ever-increasing challenge to the pharmaceutical industry. Recently, however, studies have correlated the dimerization status of the GRα with its ligand-mediated downregulation. Therefore, the current review will be discussing the major role-players in the homologous downregulation of the GRα pool, with a specific focus on previously reported GC-mediated reductions in GRα mRNA and protein levels, the molecular mechanisms through which the GRα functional pool is maintained and the possible impact of receptor conformation on GC-mediated GRα downregulation.

scholarly journals Hypoxic regulation of erythropoiesis and iron metabolism

2010 ◽  
Vol 299 (1) ◽  
pp. F1-F13 ◽  
Author(s):  
Volker H. Haase
Keyword(s):  
Transcription Factor ◽  
Blood Cell ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Oxygen Sensor ◽  
Hypoxia Inducible Factor ◽  
Adaptation To Hypoxia ◽  
Cellular Adaptation ◽  
Hypoxic Induction ◽  
Highly Sensitive

The kidney is a highly sensitive oxygen sensor and plays a central role in mediating the hypoxic induction of red blood cell production. Efforts to understand the molecular basis of oxygen-regulated erythropoiesis have led to the identification of erythropoietin (EPO), which is essential for normal erythropoiesis and to the purification of hypoxia-inducible factor (HIF), the transcription factor that regulates EPO synthesis and mediates cellular adaptation to hypoxia. Recent insights into the molecular mechanisms that control and integrate cellular and systemic erythropoiesis-promoting hypoxia responses and their potential as a therapeutic target for the treatment of renal anemia are discussed in this review.

scholarly journals A PAS Protein Directs Metabolic Reprogramming during Cryptococcal Adaptation to Hypoxia

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Youbao Zhao ◽  
Xiaorong Lin
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Metabolic Response ◽  
Regulatory Element ◽  
Metabolic Reprogramming ◽  
Adaptation To Hypoxia ◽  
Content Type ◽  
Hypoxic Adaptation ◽  
Lower Eukaryotes ◽  
Hypoxia Adaptation

ABSTRACT To aerobic organisms, low oxygen tension (hypoxia) presents a physiological challenge. To cope with such a challenge, metabolic pathways such as those used in energy production have to be adjusted. Many of such metabolic changes are orchestrated by the conserved hypoxia-inducible factors (HIFs) in higher eukaryotes. However, there are no HIF homologs in fungi or protists, and not much is known about conductors that direct hypoxic adaptation in lower eukaryotes. Here, we discovered that the transcription factor Pas2 controls the transcript levels of metabolic genes and consequently rewires metabolism for hypoxia adaptation in the human fungal pathogen Cryptococcus neoformans. Through genetic, proteomic, and biochemical analyses, we demonstrated that Pas2 directly interacts with another transcription factor, Rds2, in regulating cryptococcal hypoxic adaptation. The Pas2/Rds2 complex represents the key transcription regulator of metabolic flexibility. Its regulation of metabolism rewiring between respiration and fermentation is critical to our understanding of the cryptococcal response to low levels of oxygen. IMPORTANCE C. neoformans is the main causative agent of fungal meningitis that is responsible for about 15% of all HIV-related deaths. Although an obligate aerobic fungus, C. neoformans is well adapted to hypoxia conditions that the fungus could encounter in the host or the environment. The sterol regulatory element binding protein (SREBP) is well known for its role in cryptococcal adaptation to hypoxia through its regulation of ergosterol and lipid biosynthesis. The regulation of metabolic reprogramming under hypoxia, however, is largely unknown. Here, we discovered one key regulator, Pas2, that mediates the metabolic response to hypoxia together with another transcription factor, Rds2, in C. neoformans. The findings help define the molecular mechanisms underpinning hypoxia adaptation in this and other lower eukaryotes.

Transcription factor/DNA interactions visualized by electron spectroscopic imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 450-451
Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown
Keyword(s):  
Transcription Factor ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Phosphorus Content ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Dna Backbone ◽  
Two Parameters ◽  
High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

Ginger and Heart Health: From Mechanisms to Therapeutics

2020 ◽  
Vol 13 ◽  
Author(s):  
Sajad Fakhri ◽  
Jayanta Kumar Patra ◽  
Swagat Kumar Das ◽  
Gitishree Das ◽  
Mohammad Bagher Majnooni ◽  
...  
Keyword(s):  
Side Effects ◽  
Molecular Mechanisms ◽  
Biological Activities ◽  
Health Benefits ◽  
Herbal Medicines ◽  
Cardiovascular Complications ◽  
National Database ◽  
Heart Health ◽  
Natural Entities ◽  
Cardioprotective Effects

Background: As a major cause of morbidity and mortality, cardiovascular diseases (CVDs) are globally increasing. In spite of recent development in the management of cardiovascular complications, CVDs have remained a medical challenge. Numerous conventional drugs are used to play cardioprotective roles; however, they are associated with several side effects. Considering the rich phytochemistry and fewer side effects of herbal medicines, they have gained particular attention to develop novel herbal drugs with cardioprotective potentials. Amongst natural entities, ginger is an extensively used and well-known functional food and condiment, possessing plentiful bioactivities, like antiinflammatory, antioxidant, and antimicrobial properties in several disorders management. Objective: The current review deliberated phytochemical properties as well as the ginger/ginger constituents' biological activities and health benefits in several diseases, with particular attention to cardiovascular complications. Methods: A comprehensive research was conducted using multiple databases, including Scopus, PubMed, Medline, Web of Science, national database (Irandoc and SID), and related articles in terms of the health benefits and cardioprotective effects of ginger/ginger constituents. These data were collected from inception until August 2019. Results: In recent years, several herbal medicines were used to develop new drugs with more potency and also minor side effects. Amongst natural entities, ginger is an extensively used traditional medicine in several diseases. The crude extract, along with related pungent active constituents, is mostly attributed to heart health. The cardioprotective effects of ginger are contributed to its cardiotonic, antihypertensive, anti-hyperlipidemia, and anti-platelet effects. The signaling pathways and molecular mechanisms of ginger regarding its cardioprotective effects are also clarified. Conclusion: This study revealed the biological activities, health benefits, and cardioprotective properties of ginger/ginger constituents along with related mechanisms of action, which gave new insights to show new avenue in the treatment of CVDs.

scholarly journals Molecular regulation of Snai2 in development and disease

2019 ◽  
Vol 132 (23) ◽  
Author(s):  
Wenhui Zhou ◽  
Kayla M. Gross ◽  
Charlotte Kuperwasser
Keyword(s):  
Transcription Factor ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Zinc Finger Protein ◽  
Main Role ◽  
Biological Processes ◽  
Developmental Defects ◽  
Mesenchymal Transition ◽  
Damage Repair

ABSTRACT The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.

scholarly journals Light regulates stomatal development by modulating paracrine signaling from inner tissues

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shenqi Wang ◽  
Zimin Zhou ◽  
Rini Rahiman ◽  
Grace Sheen Yee Lee ◽  
Yuan Kai Yeo ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Gas Exchange ◽  
Cell Lineage ◽  
Developmental Outcomes ◽  
External Factors ◽  
Light Signaling ◽  
Stomatal Development ◽  
Paracrine Signaling ◽  
Mesophyll Cells ◽  
Light Signals

AbstractDevelopmental outcomes are shaped by the interplay between intrinsic and external factors. The production of stomata—essential pores for gas exchange in plants—is extremely plastic and offers an excellent system to study this interplay at the cell lineage level. For plants, light is a key external cue, and it promotes stomatal development and the accumulation of the master stomatal regulator SPEECHLESS (SPCH). However, how light signals are relayed to influence SPCH remains unknown. Here, we show that the light-regulated transcription factor ELONGATED HYPOCOTYL 5 (HY5), a critical regulator for photomorphogenic growth, is present in inner mesophyll cells and directly binds and activates STOMAGEN. STOMAGEN, the mesophyll-derived secreted peptide, in turn stabilizes SPCH in the epidermis, leading to enhanced stomatal production. Our work identifies a molecular link between light signaling and stomatal development that spans two tissue layers and highlights how an environmental signaling factor may coordinate growth across tissue types.

Biorhythm of the partial pressure of oxygen in uterine and fetal tissues

1981 ◽  
Vol 92 (4) ◽  
pp. 1305-1307
Author(s):  
A. Ya. Chizhov ◽  
V. G. Filimonov ◽  
Yu. M. Karash ◽  
R. B. Strelkov
Keyword(s):  
Partial Pressure ◽  
Partial Pressure Of Oxygen ◽  
Fetal Tissues
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