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Biology Apr 2024Ammonia is a major water quality factor influencing the survival and health of shrimp, among which the gill is the main effector organ for ammonia toxicity. In this...
Ammonia is a major water quality factor influencing the survival and health of shrimp, among which the gill is the main effector organ for ammonia toxicity. In this study, we chose two types of that were cultured in 30‱ seawater and domesticated in 3‱ low salinity, respectively, and then separately subjected to ammonia stress for 14 days under seawater and low-salinity conditions, of which the 3‱ low salinity-cultured shrimp were domesticated from the shrimp cultured in 30‱ seawater after 27 days of gradual salinity desalination. In detail, this study included four groups, namely the SC group (ammonia-N 0 mg/L, salinity 30‱), SAN group (ammonia-N 10 mg/L, salinity 30‱), LC group (ammonia-N 0 mg/L, salinity 3‱), and LAN group (ammonia-N 10 mg/L, salinity 3‱). The ammonia stress lasted for 14 days, and then the changes in the morphological structure and physiological function of the gills were explored. The results show that ammonia stress caused the severe contraction of gill filaments and the deformation or even rupture of gill vessels. Biochemical indicators of oxidative stress, including LPO and MDA contents, as well as T-AOC and GST activities, were increased in the SAN and LAN groups, while the activities of CAT and POD and the mRNA expression levels of antioxidant-related genes (, , , , and ) were decreased. In addition, the mRNA expression levels of the genes involved in ER stress ( and ), apoptosis (, , and ), detoxification (, , and ), glucose metabolism (, , , and ), and the tricarboxylic acid cycle (, , , and ) were decreased in the SAN and LAN groups; the levels of electron-transport chain-related genes (, , and ), and the and genes were decreased in the SAN group but increased in the LAN group; and the level of the gene was decreased but the gene was increased in the SAN and LAN groups. The mRNA expression levels of osmotic regulation-related genes (, , and ) were decreased in the SAN group, while the level of the gene was increased in the LAN group; the gene was decreased in both two groups. The results demonstrate that ammonia stress could influence the physiological homeostasis of the shrimp gills, possibly by damaging the tissue morphology, and affecting the redox, ER function, apoptosis, detoxification, energy metabolism, and osmoregulation.
PubMed: 38666893
DOI: 10.3390/biology13040281 -
Biology Mar 2024The expression of the Na-K-2Cl cotransporter (NKCC), widely associated with cell volume regulation, has never been directly demonstrated in annelids. Its putative...
The expression of the Na-K-2Cl cotransporter (NKCC), widely associated with cell volume regulation, has never been directly demonstrated in annelids. Its putative presence was firstly recovered in silico, and then using immunofluorescence, its signal was retrieved for the first time in different tissues of four species of estuarine annelids from southern Brazil that are regularly subjected to salinity fluctuations. We tested two euryhaline species (wide salinity tolerance), the nereidids and (habitat salinity: ~10-28 psu), and two stenohaline species (restricted salinity tolerance), the nephtyid (habitat salinity: ~6-10 psu), and the melinnid (habitat salinity: ~28-35 psu). All four species showed specific immunofluorescent labelling for NKCC-like expression. However, the expression of an NKCC-like protein was not homogeneous among them. The free-living/burrowers (both euryhaline nereidids and the stenohaline nephtyid) displayed a widespread signal for an NKCC-like protein along their bodies, in contrast to the stenohaline sedentary melinnid, in which the signal was restricted to the branchiae and the internal tissues of the body. The results are compatible with NKCC involvement in cell volume, especially in annelids that face wide variations in salinity in their habitats.
PubMed: 38666847
DOI: 10.3390/biology13040235 -
Iranian Journal of Kidney Diseases Mar 2024In this brief communication, we reemphasize the importance of critical thinking in clinical practice using the example of edema. The common practice of thinking and...
In this brief communication, we reemphasize the importance of critical thinking in clinical practice using the example of edema. The common practice of thinking and inquiry by practicing clinicians has beneficial implications for healthcare by improving outcomes and patient care while alleviating the burden of misconceptions in practice. We provide an in-depth and interactive investigation of physiological concepts as a foundation for understanding body fluid dynamics. Finally, we offer a new classification of symptoms of heart failure. DOI: 10.52547/ijkd.8171.
Topics: Humans; Heart Failure; Edema; Body Fluids; Thinking; Water-Electrolyte Balance
PubMed: 38660694
DOI: 10.5254/1aytkx77 -
Frontiers in Plant Science 2024The exogenous use of the redox compound (HO) plays a significant role in abiotic stress tolerance. The present study investigated various HO application methods (seed...
The exogenous use of the redox compound (HO) plays a significant role in abiotic stress tolerance. The present study investigated various HO application methods (seed priming, foliar spray, and surface irrigation) with varying concentration levels (0 mM, 5 mM, 10 mM, 15 mM, 40 mM, 80 mM, and 160 mM) to evaluate the efficiency of supplying exogenous HO to quinoa under water-deficit conditions. Drought stress reduced quinoa growth and yield by perturbing morphological traits, leading to the overproduction of reactive oxygen species and increased electrolyte leakage. Although all studied modes of HO application improved quinoa performance, surface irrigation was found to be sensitive, causing oxidative damage in the present study. Seed priming showed a prominent increase in plant height due to profound emergence indexes compared to other modes under drought conditions. Strikingly, seed priming followed by foliar spray improved drought tolerance in quinoa and showed higher grain yield compared to surface irrigations. This increase in the yield performance of quinoa was attributed to improvements in total chlorophyll (37%), leaf relative water content (RWC; 20%), superoxide dismutase (SOD; 35%), peroxidase (97%), polyphenol oxidase (60%), and phenylalanine ammonia-lyase (58%) activities, and the accumulation of glycine betaine (96%), total soluble protein (TSP; 17%), proline contents (35%), and the highest reduction in leaf malondialdehyde contents (MDA; 36%) under drought stress. PCA analysis indicated that physio-biochemical traits (proline, SOD, TSP, total chlorophyll, MSI, and RWC) were strongly positively correlated with grain yield, and their contribution was much higher in redox priming than other application methods. In conclusion, exogenous HO application, preferably redox priming, could be chosen to decrease drought-induced performance and yield losses in quinoa.
PubMed: 38638353
DOI: 10.3389/fpls.2024.1253677 -
BMC Biology Apr 2024Cyprinidae, the largest fish family, encompasses approximately 367 genera and 3006 species. While they exhibit remarkable adaptability to diverse aquatic environments,...
BACKGROUND
Cyprinidae, the largest fish family, encompasses approximately 367 genera and 3006 species. While they exhibit remarkable adaptability to diverse aquatic environments, it is exceptionally rare to find them in seawater, with the Far Eastern daces being of few exceptions. Therefore, the Far Eastern daces serve as a valuable model for studying the genetic mechanisms underlying seawater adaptation in Cyprinidae.
RESULTS
Here, we sequenced the chromosome-level genomes of two Far Eastern daces (Pseudaspius brandtii and P. hakonensis), the two known cyprinid fishes found in seawater, and performed comparative genomic analyses to investigate their genetic mechanism of seawater adaptation. Demographic history reconstruction of the two species reveals that their population dynamics are correlated with the glacial-interglacial cycles and sea level changes. Genomic analyses identified Pseudaspius-specific genetic innovations related to seawater adaptation, including positively selected genes, rapidly evolving genes, and conserved non-coding elements (CNEs). Functional assays of Pseudaspius-specific variants of the prolactin (prl) gene showed enhanced cell adaptation to greater osmolarity. Functional assays of Pseudaspius specific CNEs near atg7 and usp45 genes suggest that they exhibit higher promoter activity and significantly induced at high osmolarity.
CONCLUSIONS
Our results reveal the genome-wide evidence for the evolutionary adaptation of cyprinid fishes to seawater, offering valuable insights into the molecular mechanisms supporting the survival of migratory fish in marine environments. These findings are significant as they contribute to our understanding of how cyprinid fishes navigate and thrive in diverse aquatic habitats, providing useful implications for the conservation and management of marine ecosystems.
Topics: Animals; Phylogeny; Ecosystem; Cyprinidae; Genomics; Seawater; Adaptation, Physiological
PubMed: 38637780
DOI: 10.1186/s12915-024-01885-2 -
Journal of Critical Care Aug 2024A positive fluid balance (FB) is associated with harm in intensive care unit (ICU) patients with acute kidney injury (AKI). We aimed to understand how a positive balance... (Observational Study)
Observational Study
PURPOSE
A positive fluid balance (FB) is associated with harm in intensive care unit (ICU) patients with acute kidney injury (AKI). We aimed to understand how a positive balance develops in such patients.
METHODS
Multinational, retrospective cohort study of critically ill patients with AKI not requiring renal replacement therapy.
RESULTS
AKI occurred at a median of two days after admission in 7894 (17.3%) patients. Cumulative FB became progressively positive, peaking on day three despite only 848 (10.7%) patients receiving fluid resuscitation in the ICU. In those three days, persistent crystalloid use (median:60.0 mL/h; IQR 28.9-89.2), nutritional intake (median:18.2 mL/h; IQR 0.0-45.9) and limited urine output (UO) (median:70.8 mL/h; IQR 49.0-96.7) contributed to a positive FB. Although UO increased each day, it failed to match input, with only 797 (10.1%) patients receiving diuretics in ICU. After adjustment, a positive FB four days after AKI diagnosis was associated with an increased risk of hospital mortality (OR 1.12;95% confidence intervals 1.05-1.19;p-value <0.001).
CONCLUSION
Among ICU patients with AKI, cumulative FB increased after diagnosis and was associated with an increased risk of mortality. Continued crystalloid administration, increased nutritional intake, limited UO, and minimal use of diuretics all contributed to positive FB.
KEY POINTS
Question How does a positive fluid balance develop in critically ill patients with acute kidney injury? Findings Cumulative FB increased after AKI diagnosis and was secondary to persistent crystalloid fluid administration, increasing nutritional fluid intake, and insufficient urine output. Despite the absence of resuscitation fluid and an increasing cumulative FB, there was persistently low diuretics use, ongoing crystalloid use, and a progressive escalation of nutritional fluid therapy. Meaning Current management results in fluid accumulation after diagnosis of AKI, as a result of ongoing crystalloid administration, increasing nutritional fluid, limited urine output and minimal diuretic use.
Topics: Humans; Acute Kidney Injury; Retrospective Studies; Female; Male; Water-Electrolyte Balance; Middle Aged; Fluid Therapy; Intensive Care Units; Critical Illness; Aged; Hospital Mortality; Crystalloid Solutions; Diuretics
PubMed: 38609773
DOI: 10.1016/j.jcrc.2024.154809 -
Cells Mar 2024The oral mucosa represents a defensive barrier between the external environment and the rest of the body. Oral mucosal cells are constantly bathed in hypotonic saliva...
Oral Antiviral Defense: Saliva- and Beverage-like Hypotonicity Dynamically Regulate Formation of Membraneless Biomolecular Condensates of Antiviral Human MxA in Oral Epithelial Cells.
The oral mucosa represents a defensive barrier between the external environment and the rest of the body. Oral mucosal cells are constantly bathed in hypotonic saliva (normally one-third tonicity compared to plasma) and are repeatedly exposed to environmental stresses of tonicity, temperature, and pH by the drinks we imbibe (e.g., hypotonic: water, tea, and coffee; hypertonic: assorted fruit juices, and red wines). In the mouth, the broad-spectrum antiviral mediator MxA (a dynamin-family large GTPase) is constitutively expressed in healthy periodontal tissues and induced by Type III interferons (e.g., IFN-λ1/IL-29). Endogenously induced human MxA and exogenously expressed human GFP-MxA formed membraneless biomolecular condensates in the cytoplasm of oral carcinoma cells (OECM1 cell line). These condensates likely represent storage granules in equilibrium with antivirally active dispersed MxA. Remarkably, cytoplasmic MxA condensates were exquisitely sensitive sensors of hypotonicity-the condensates in oral epithelium disassembled within 1-2 min of exposure of cells to saliva-like one-third hypotonicity, and spontaneously reassembled in the next 4-7 min. Water, tea, and coffee enhanced this disassembly. Fluorescence changes in OECM1 cells preloaded with calcein-AM (a reporter of cytosolic "macromolecular crowding") confirmed that this process involved macromolecular uncrowding and subsequent recrowding secondary to changes in cell volume. However, hypertonicity had little effect on MxA condensates. The spontaneous reassembly of GFP-MxA condensates in oral epithelial cells, even under continuous saliva-like hypotonicity, was slowed by the protein-phosphatase-inhibitor cyclosporin A (CsA) and by the K-channel-blocker tetraethylammonium chloride (TEA); this is suggestive of the involvement of the volume-sensitive WNK kinase-protein phosphatase (PTP)-K-Cl cotransporter (KCC) pathway in the regulated volume decrease (RVD) during condensate reassembly in oral cells. The present study identifies a novel subcellular consequence of hypotonic stress in oral epithelial cells, in terms of the rapid and dynamic changes in the structure of one class of phase-separated biomolecular condensates in the cytoplasm-the antiviral MxA condensates. More generally, the data raise the possibility that hypotonicity-driven stresses likely affect other intracellular functions involving liquid-liquid phase separation (LLPS) in cells of the oral mucosa.
Topics: Humans; Biomolecular Condensates; Coffee; Epithelial Cells; Saliva; Tea; Water; Myxovirus Resistance Proteins
PubMed: 38607029
DOI: 10.3390/cells13070590 -
Physiological Reports Apr 2024Clinical hyponatremia guidelines, protocols and flowcharts are a convenient means for clinicians to quickly establish an etiological diagnosis for hyponatremia, and...
Clinical hyponatremia guidelines, protocols and flowcharts are a convenient means for clinicians to quickly establish an etiological diagnosis for hyponatremia, and facilitate its often complex analysis. Unfortunately, they often erroneously attribute multifactorial hyponatremia to a single cause, which is potentially dangerous. In this manuscript, a novel criterion is proposed to quickly determine the physiological relevance of non-osmotic arginine vasopressin (AVP) release, and to add nuance to hyponatremia analysis. While analyzing hypotonic hyponatremia, it is imperative to not only verify whether or not a certain degree of inappropriate AVP release is present, but also to ascertain whether it-in itself-could sufficiently explain the observed hyponatremia, as these two are not always synonymous. Using well-known concepts from renal physiology to combine the electrolyte-free water balance and solute-free water balance, a novel physiological criterion is derived mathematically to easily distinguish three common hyponatremia scenarios, and to further elucidate the underlying etiology. The derived criterion can hopefully facilitate the clinician's and physiologist's interpretation of plasma and urine parameters in a patient presenting with hyponatremia, and warn against the important clinical pitfall of attributing hyponatremia too readily to a single cause.
Topics: Humans; Hyponatremia; Arginine Vasopressin; Water-Electrolyte Balance; Water
PubMed: 38584119
DOI: 10.14814/phy2.15967 -
ELife Apr 2024Natural environments of living organisms are often dynamic and multifactorial, with multiple parameters fluctuating over time. To better understand how cells respond to...
Natural environments of living organisms are often dynamic and multifactorial, with multiple parameters fluctuating over time. To better understand how cells respond to dynamically interacting factors, we quantified the effects of dual fluctuations of osmotic stress and glucose deprivation on yeast cells using microfluidics and time-lapse microscopy. Strikingly, we observed that cell proliferation, survival, and signaling depend on the phasing of the two periodic stresses. Cells divided faster, survived longer, and showed decreased transcriptional response when fluctuations of hyperosmotic stress and glucose deprivation occurred in phase than when the two stresses occurred alternatively. Therefore, glucose availability regulates yeast responses to dynamic osmotic stress, showcasing the key role of metabolic fluctuations in cellular responses to dynamic stress. We also found that mutants with impaired osmotic stress response were better adapted to alternating stresses than wild-type cells, showing that genetic mechanisms of adaptation to a persistent stress factor can be detrimental under dynamically interacting conditions.
Topics: Saccharomyces cerevisiae; Osmotic Pressure; Osmoregulation; Cell Proliferation; Glucose
PubMed: 38568203
DOI: 10.7554/eLife.88750 -
Physiological Reports Apr 2024Mutations in PKD1 and PKD2 cause autosomal dominant polycystic kidney disease (ADPKD), which is characterized by the formation of fluid-filled cysts in the kidney. In a...
Mutations in PKD1 and PKD2 cause autosomal dominant polycystic kidney disease (ADPKD), which is characterized by the formation of fluid-filled cysts in the kidney. In a subset of ADPKD patients, reduced blood calcium (Ca) and magnesium (Mg) concentrations are observed. As cystic fluid contains increased ATP concentrations and purinergic signaling reduces electrolyte reabsorption, we hypothesized that inhibiting ATP release could normalize blood Ca and Mg levels in ADPKD. Inducible kidney-specific Pkd1 knockout mice (iKsp-Pkd1) exhibit hypocalcemia and hypomagnesemia in a precystic stage and show increased expression of the ATP-release channel pannexin-1. Therefore, we administered the pannexin-1 inhibitor brilliant blue-FCF (BB-FCF) every other day from Day 3 to 28 post-induction of Pkd1 gene inactivation. On Day 29, both serum Ca and Mg concentrations were reduced in iKsp-Pkd1 mice, while urinary Ca and Mg excretion was similar between the genotypes. However, serum and urinary levels of Ca and Mg were unaltered by BB-FCF treatment, regardless of genotype. BB-FCF did significantly decrease gene expression of the ion channels Trpm6 and Trpv5 in both control and iKsp-Pkd1 mice. Finally, no renoprotective effects of BB-FCF treatment were observed in iKsp-Pkd1 mice. Thus, administration of BB-FCF failed to normalize serum Ca and Mg levels.
Topics: Animals; Humans; Mice; Adenosine Triphosphate; Kidney; Mice, Knockout; Mutation; Polycystic Kidney, Autosomal Dominant; TRPP Cation Channels; Water-Electrolyte Balance
PubMed: 38561249
DOI: 10.14814/phy2.15956