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Scientific Reports Jul 2023MYC transcription factors have critical roles in facilitating a variety of cellular functions that have been highly conserved among species during evolution. However,...
MYC transcription factors have critical roles in facilitating a variety of cellular functions that have been highly conserved among species during evolution. However, despite circumstantial evidence for an involvement of MYC in animal osmoregulation, mechanistic links between MYC function and osmoregulation are missing. Mozambique tilapia (Oreochromis mossambicus) represents an excellent model system to study these links because it is highly euryhaline and highly tolerant to osmotic (salinity) stress at both the whole organism and cellular levels of biological organization. Here, we utilize an O. mossambicus brain cell line and an optimized vector-based CRISPR/Cas9 system to functionally disrupt MYC in the tilapia genome and to establish causal links between MYC and cell functions, including cellular osmoregulation. A cell isolation and dilution strategy yielded polyclonal myca (a gene encoding MYC) knockout (ko) cell pools with low genetic variability and high gene editing efficiencies (as high as 98.2%). Subsequent isolation and dilution of cells from these pools produced a myca ko cell line harboring a 1-bp deletion that caused a frameshift mutation. This frameshift functionally inactivated the transcriptional regulatory and DNA-binding domains predicted by bioinformatics and structural analyses. Both the polyclonal and monoclonal myca ko cell lines were viable, propagated well in standard medium, and differed from wild-type cells in morphology. As such, they represent a new tool for causally linking myca to cellular osmoregulation and other cell functions.
Topics: Animals; Tilapia; CRISPR-Cas Systems; Osmoregulation; Gene Expression Regulation; Cell Line
PubMed: 37495710
DOI: 10.1038/s41598-023-37928-x -
Cold Spring Harbor Perspectives in... Nov 2021Since colonizing land, plants have developed mechanisms to tolerate a broad range of abiotic stresses that include flooding, drought, high salinity, and nutrient... (Review)
Review
Since colonizing land, plants have developed mechanisms to tolerate a broad range of abiotic stresses that include flooding, drought, high salinity, and nutrient limitation. Roots play a key role acclimating plants to these as their developmental plasticity enables them to grow toward more favorable conditions and away from limiting or harmful stresses. The phytohormone auxin plays a key role translating these environmental signals into developmental outputs. This is achieved by modulating auxin levels and/or signaling, often through cross talk with other hormone signals like abscisic acid (ABA) or ethylene. In our review, we discuss how auxin controls root responses to water, osmotic and nutrient-related stresses, and describe how the synthesis, degradation, transport, and response of this key signaling hormone helps optimize root architecture to maximize resource acquisition while limiting the impact of abiotic stresses.
Topics: Ethylenes; Indoleacetic Acids; Metals, Heavy; Nitrogen; Osmoregulation; Phosphates; Plant Roots; Receptor Cross-Talk
PubMed: 33903159
DOI: 10.1101/cshperspect.a040014 -
Comparative Biochemistry and... Sep 2021Decapod crustaceans show variable degrees of euryhalinity and osmoregulatory capacity, by responding to salinity changes through anisosmotic extracellular regulation...
Decapod crustaceans show variable degrees of euryhalinity and osmoregulatory capacity, by responding to salinity changes through anisosmotic extracellular regulation and/or cell volume regulation. Cell volume regulatory mechanisms involve exchange of inorganic ions between extra- and intra-cellular (tissue) compartments. Here, this interplay of inorganic ions between both compartments has been evaluated in four decapod species with distinct habitats and osmoregulatory strategies. The marine/estuarine species Litopenaeus vannamei (Lv) and Callinectes danae (Cd) were submitted to reduced salinity (15‰), after acclimation to 25 and 30‰, respectively. The freshwater Macrobrachium acanthurus (Ma) and Aegla schmitti (As) were submitted to increased salinity (25‰). The four species were salinity-challenged for both 5 and 10 days. Hemolymph osmolality, sodium, chloride, potassium, and magnesium were assayed. The same inorganic ions were quantified in muscle samples. Muscle hydration (MH) and ninhydrin-positive substances (NPS) were also determined. Lv showed slight hemolymph dilution, increased MH and no osmotically-relevant decreases in muscle osmolytes; Cd displayed hemolymph dilution, decreased muscular NaCl and stable MH; Ma showed hypo-regulation and steady MH, with no change in muscle ions; As conformed hemolymph sodium but hypo-regulated chloride, had stable MH and increased muscle NPS and ion levels. Hemolymph and muscle ions (especially chloride) of As were highly correlated (Pearson, +0.83). Significant exchanges between hemolymph and muscle ionic pools were more evident in the two species with comparatively less AER regulatory power, C. danae and A. schmitti. Our findings endorse that the interplay between extracellular and tissue ionic pools is especially detectable in euryhaline species with relatively lower osmoregulatory strength.
Topics: Animals; Cadmium; Decapoda; Hemolymph; Ions; Magnesium; Osmolar Concentration; Osmoregulation; Palaemonidae; Penaeidae; Potassium; Salinity; Sodium Chloride; Species Specificity; Water-Electrolyte Balance
PubMed: 34098129
DOI: 10.1016/j.cbpa.2021.111001 -
International Journal of Molecular... Feb 2021Soil salinity is a serious menace in rice production threatening global food security. Rice responses to salt stress involve a series of biological processes, including... (Review)
Review
Soil salinity is a serious menace in rice production threatening global food security. Rice responses to salt stress involve a series of biological processes, including antioxidation, osmoregulation or osmoprotection, and ion homeostasis, which are regulated by different genes. Understanding these adaptive mechanisms and the key genes involved are crucial in developing highly salt-tolerant cultivars. In this review, we discuss the molecular mechanisms of salt tolerance in rice-from sensing to transcriptional regulation of key genes-based on the current knowledge. Furthermore, we highlight the functionally validated salt-responsive genes in rice.
Topics: Gene Expression Regulation, Plant; Oryza; Osmoregulation; Phenotype; Plant Proteins; Salt Tolerance; Stress, Physiological
PubMed: 33668247
DOI: 10.3390/ijms22052254 -
Nephron. Physiology 2011Although hyponatremia is a recognized complication of several inflammatory diseases, its pathophysiology in this setting has remained elusive until recently. A growing... (Review)
Review
Although hyponatremia is a recognized complication of several inflammatory diseases, its pathophysiology in this setting has remained elusive until recently. A growing body of evidence now points to an important role for interleukin-6 in the non-osmotic release of vasopressin. Here, we review this evidence by exploring the immuno-neuroendocrine pathways connecting interleukin-6 with vasopressin. The importance of these connections extends to several clinical scenarios of hyponatremia and inflammation, including hospital-acquired hyponatremia, postoperative hyponatremia, exercise-associated hyponatremia, and hyponatremia in the elderly. Besides insights in pathophysiology, the recognition of the propensity for antidiuresis during inflammation is also important with regard to monitoring patients and selecting the appropriate intravenous fluid regimen, for which recommendations are provided.
Topics: Cytokines; Humans; Hyponatremia; Inflammation; Interleukin-6; Signal Transduction; Vasopressins; Water-Electrolyte Balance
PubMed: 21196778
DOI: 10.1159/000322238 -
Hereditas Feb 2020Tobacco, an economic crop and important model plant, has received more progress in salt tolerance with the aid of transgenic technique. Salt stress has become a key... (Review)
Review
Tobacco, an economic crop and important model plant, has received more progress in salt tolerance with the aid of transgenic technique. Salt stress has become a key research field in abiotic stress. The study of tobacco promotes the understanding about the important adjustment for survival in high salinity environments, including cellular ion transport, osmotic regulation, antioxidation, signal transduction and expression regulation, and protection of cells from stress damage. Genes, which response to salt, have been studied using targeted transgenic technologies in tobacco plants to investigate the molecular mechanisms. The transgenic tobacco plants exhibited higher seed germination and survival rates, better root and shoot growth under salt stress treatments. Transgenic approach could be the promising option for enhancing tobacco production under saline condition. This review highlighted the salt tolerance molecular mechanisms of tobacco.
Topics: Crops, Agricultural; Gene Expression Regulation, Plant; Ion Transport; Osmoregulation; Plants, Genetically Modified; Reactive Oxygen Species; Salt Tolerance; Signal Transduction; Stress, Physiological; Nicotiana
PubMed: 32093781
DOI: 10.1186/s41065-020-00118-0 -
International Review of Cell and... 2013While free-living protists are usually subjected to hyposmotic environments, parasitic protists are also in contact with hyperosmotic habitats. Recent work in one of... (Review)
Review
While free-living protists are usually subjected to hyposmotic environments, parasitic protists are also in contact with hyperosmotic habitats. Recent work in one of these parasites, Trypanosoma cruzi, has revealed that its contractile vacuole complex, which usually collects and expels excess water as a mechanism of regulatory volume decrease after hyposmotic stress, has also a role in cell shrinking when the cells are submitted to hyperosmotic stress. Trypanosomes also have an acidic calcium store rich in polyphosphate (polyP), named the acidocalcisome, which is involved in their response to osmotic stress. Here, we review newly emerging insights on the role of acidocalcisomes and the contractile vacuole complex in the cellular response to hyposmotic and hyperosmotic stresses. We also review the current state of knowledge on the composition of these organelles and their other roles in calcium homeostasis and protein trafficking.
Topics: Organelles; Osmoregulation; Trypanosoma cruzi; Vacuoles
PubMed: 23890380
DOI: 10.1016/B978-0-12-407695-2.00002-0 -
Clinical Journal of the American... May 2019
Topics: Critical Illness; Humans; Hypernatremia; Hyponatremia; Sodium; Water-Electrolyte Balance
PubMed: 31064771
DOI: 10.2215/CJN.02950319 -
ELife Jul 2021The causative agent of Chagas disease undergoes drastic morphological and biochemical modifications as it passes between hosts and transitions from extracellular to...
The causative agent of Chagas disease undergoes drastic morphological and biochemical modifications as it passes between hosts and transitions from extracellular to intracellular stages. The osmotic and mechanical aspects of these cellular transformations are not understood. Here we identify and characterize a novel mechanosensitive channel in (TcMscS) belonging to the superfamily of small-conductance mechanosensitive channels (MscS). TcMscS is activated by membrane tension and forms a large pore permeable to anions, cations, and small osmolytes. The channel changes its location from the contractile vacuole complex in epimastigotes to the plasma membrane as the parasites develop into intracellular amastigotes. TcMscS knockout parasites show significant fitness defects, including increased cell volume, calcium dysregulation, impaired differentiation, and a dramatic decrease in infectivity. Our work provides mechanistic insights into components supporting pathogen adaptation inside the host, thus opening the exploration of mechanosensation as a prerequisite for protozoan infectivity.
Topics: Antibodies, Protozoan; CRISPR-Cas Systems; Calcium; Cell Differentiation; Cloning, Molecular; Computational Biology; Electrophysiological Phenomena; Gene Expression Regulation; HEK293 Cells; Humans; Ion Channels; Mechanotransduction, Cellular; Mutation; Osmoregulation; Osmotic Pressure; Protein Conformation; Protozoan Proteins; Trypanosoma cruzi
PubMed: 34212856
DOI: 10.7554/eLife.67449 -
PLoS Pathogens Jan 2020
Topics: Animals; Anthelmintics; Humans; Nematoda; Nematode Infections; Osmoregulation; Water
PubMed: 31999796
DOI: 10.1371/journal.ppat.1008202