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2.
PLoS Genet ; 20(7): e1011288, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38990837

ABSTRACT

We examined the associations of vegetarianism with metabolic biomarkers using traditional and genetic epidemiology. First, we addressed inconsistencies in self-reported vegetarianism among UK Biobank participants by utilizing data from two dietary surveys to find a cohort of strict European vegetarians (N = 2,312). Vegetarians were matched 1:4 with nonvegetarians for non-genetic association analyses, revealing significant effects of vegetarianism in 15 of 30 biomarkers. Cholesterol measures plus vitamin D were significantly lower in vegetarians, while triglycerides were higher. A genome-wide association study revealed no genome-wide significant (GWS; 5×10-8) associations with vegetarian behavior. We performed genome-wide gene-vegetarianism interaction analyses for the biomarkers, and detected a GWS interaction impacting calcium at rs72952628 (P = 4.47×10-8). rs72952628 is in MMAA, a B12 metabolic pathway gene; B12 has major deficiency potential in vegetarians. Gene-based interaction tests revealed two significant genes, RNF168 in testosterone (P = 1.45×10-6) and DOCK4 in estimated glomerular filtration rate (eGFR) (P = 6.76×10-7), which have previously been associated with testicular and renal traits, respectively. These nutrigenetic findings indicate genotype can modify the associations between vegetarianism and health outcomes.


Subject(s)
Biomarkers , Calcium , Diet, Vegetarian , Genome-Wide Association Study , Glomerular Filtration Rate , Testosterone , Humans , Male , Glomerular Filtration Rate/genetics , Testosterone/blood , Female , Biomarkers/blood , Middle Aged , Calcium/metabolism , Polymorphism, Single Nucleotide , Vegetarians , Aged , Vitamin D/blood , Adult , Ubiquitin-Protein Ligases/genetics
3.
Curr Protoc ; 4(7): e1101, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38980221

ABSTRACT

Cardiovascular diseases have emerged as one of the leading causes of human mortality, but the discovery of new drugs has been hindered by the absence of suitable in vitro platforms. In recent decades, continuously refined protocols for differentiating human induced pluripotent stem cells (hiPSCs) into hiPSC-derived cardiomyocytes (hiPSC-CMs) have significantly advanced disease modeling and drug screening; however, this has led to an increasing need to monitor the function of hiPSC-CMs. The precise regulation of action potentials (APs) and intracellular calcium (Ca2+) transients is critical for proper excitation-contraction coupling and cardiomyocyte function. These important parameters are usually adversely affected in cardiovascular diseases or under cardiotoxic conditions and can be measured using optical imaging-based techniques. However, this procedure is complex and technologically challenging. We have adapted the IonOptix system to simultaneously measure APs and Ca2+ transients in hiPSC-CMs loaded with the fluorescent dyes FluoVolt and Rhod 2, respectively. This system serves as a powerful high-throughput platform to facilitate the discovery of new compounds to treat cardiovascular diseases with the cellular phenotypes of abnormal APs and Ca2+ handling. Here, we present a comprehensive protocol for hiPSC-CM preparation, device setup, optical imaging, and data analysis. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Maintenance and seeding of hiPSC-CMs Basic Protocol 2: Simultaneous detection of action potentials and Ca2+ transients in hiPSC-CMs.


Subject(s)
Action Potentials , Calcium , Induced Pluripotent Stem Cells , Myocytes, Cardiac , Optical Imaging , Humans , Induced Pluripotent Stem Cells/metabolism , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/drug effects , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/drug effects , Action Potentials/drug effects , Calcium/metabolism , Optical Imaging/methods , Cell Differentiation/drug effects
4.
FASEB J ; 38(13): e23737, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38953724

ABSTRACT

Meningiomas are the most common primary intracranial tumors and account for nearly 30% of all nervous system tumors. Approximately half of meningioma patients exhibit neurofibromin 2 (NF2) gene inactivation. Here, NF2 was shown to interact with the endoplasmic reticulum (ER) calcium (Ca2+) channel inositol 1,4,5-trisphosphate receptor 1 (IP3R1) in IOMM-Lee, a high-grade malignant meningioma cell line, and the F1 subdomain of NF2 plays a critical role in this interaction. Functional assays indicated that NF2 promotes the phosphorylation of IP3R (Ser 1756) and IP3R-mediated endoplasmic reticulum (ER) Ca2+ release by binding to IP3R1, which results in Ca2+-dependent apoptosis. Knockout of NF2 decreased Ca2+ release and promoted resistance to apoptosis, which was rescued by wild-type NF2 overexpression but not by F1 subdomain deletion truncation overexpression. The effects of NF2 defects on the development of tumors were further studied in mouse models. The decreased expression level of NF2 caused by NF2 gene knockout or mutation affects the activity of the IP3R channel, which reduces Ca2+-dependent apoptosis, thereby promoting the development of tumors. We elucidated the interaction patterns of NF2 and IP3R1, revealed the molecular mechanism through which NF2 regulates IP3R1-mediated Ca2+ release, and elucidated the new pathogenic mechanism of meningioma-related NF2 variants. Our study broadens the current understanding of the biological function of NF2 and provides ideas for drug screening of NF2-associated meningioma.


Subject(s)
Apoptosis , Calcium Signaling , Calcium , Inositol 1,4,5-Trisphosphate Receptors , Meningeal Neoplasms , Meningioma , Animals , Humans , Mice , Calcium/metabolism , Cell Line, Tumor , Endoplasmic Reticulum/metabolism , Inositol 1,4,5-Trisphosphate Receptors/metabolism , Inositol 1,4,5-Trisphosphate Receptors/genetics , Meningeal Neoplasms/metabolism , Meningeal Neoplasms/pathology , Meningeal Neoplasms/genetics , Meningioma/metabolism , Meningioma/pathology , Meningioma/genetics , Neurofibromin 2
5.
Cell Mol Life Sci ; 81(1): 285, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38969941

ABSTRACT

Volume regulation is essential for cell homeostasis and physiological function. Amongst the sensory molecules that have been associated with volume regulation is the transient receptor potential vanilloid 4 (TRPV4), which is a non-selective cation channel that in conjunction with aquaporins, typically controls regulatory volume decrease (RVD). Here we show that the interaction between orthologous AQP4 (Aqp4a) and TRPV4 (Trpv4) is important for regulatory volume increase (RVI) in post-activated marine fish spermatozoa under high osmotic stress. Based upon electrophysiological, volumetric, and in vivo and ex vivo functional experiments using the pharmacological and immunological inhibition of Aqp4a and Trpv4 our model suggests that upon ejaculation and exposure to the hypertonic seawater, spermatozoon shrinkage is initially mediated by water efflux through Aqp1aa in the flagellar tail. The shrinkage results in an increase in intracellular Ca2+ concentration, and the activation of sperm motility and a Na+/K+/2Cl- (NKCC1) cotransporter. The activity of NKCC1 is required for the initiation of cell swelling, which secondarily activates the Aqp4a-Trpv4 complex to facilitate the influx of water via Aqp4a-M43 and Ca2+ via Trpv4 and L-type channels for the mediation of RVI. The inhibitory experiments show that blocking of each of these events prevents either shrinkage or RVI. Our data thus reveal that post-activated marine fish spermatozoa are capable of initiating RVI under a high hypertonic stress, which is essential for the maintenance of sperm motility.


Subject(s)
Cell Size , Osmotic Pressure , Sperm Motility , Spermatozoa , TRPV Cation Channels , Animals , Male , TRPV Cation Channels/metabolism , TRPV Cation Channels/genetics , Spermatozoa/metabolism , Sperm Motility/physiology , Aquaporin 4/metabolism , Aquaporin 4/genetics , Calcium/metabolism , Fishes/metabolism , Fishes/physiology , Swimming , Solute Carrier Family 12, Member 2/metabolism , Solute Carrier Family 12, Member 2/genetics
6.
Biol Res ; 57(1): 44, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38965573

ABSTRACT

BACKGROUND: Exposure of humans and animals to heavy metals is increasing day-by-day; thus, lead even today remains of significant public health concern. According to CDC, blood lead reference value (BLRV) ranges from 3.5 µg/dl to 5 µg/dl in adults. Recently, almost 2.6% decline in male fertility per year has been reported but the cause is not well established. Lead (Pb2+) affects the size of testis, semen quality, and secretory functions of prostate. But the molecular mechanism(s) of lead toxicity in sperm cells is not clear. Thus, present study was undertaken to evaluate the adverse effects of lead acetate at environmentally relevant exposure levels (0.5, 5, 10 and 20 ppm) on functional and molecular dynamics of spermatozoa of bucks following in vitro exposure for 15 min and 3 h. RESULTS: Lead significantly decreased motility, viable count, and motion kinematic patterns of spermatozoa like curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency and maximum amplitude of head lateral displacement even at 5 ppm concentration. Pb2+ modulated intracellular cAMP and Ca2+ levels in sperm cells through L-type calcium channels and induced spontaneous or premature acrosome reaction (AR) by increasing tyrosine phosphorylation of sperm proteins and downregulated mitochondrial transmembrane potential. Lead significantly increased DNA damage and apoptosis as well. Electron microscopy studies revealed Pb2+ -induced deleterious effects on plasma membrane of head and acrosome including collapsed cristae in mitochondria. CONCLUSIONS: Pb2+ not only mimics Ca2+ but also affects cellular targets involved in generation of cAMP, mitochondrial transmembrane potential, and ionic exchange. Lead seems to interact with Ca2+ channels because of charge similarity and probably enters the sperm cell through these channels and results in hyperpolarization. Our findings also indicate lead-induced TP and intracellular Ca2+ release in spermatozoa which in turn may be responsible for premature acrosome exocytosis which is essential feature of capacitation for fertilization. Thus, lead seems to reduce the fertilizing capacity of spermatozoa even at 0.5 ppm concentrations.


Subject(s)
Acrosome Reaction , Acrosome , Calcium , Lead , Sperm Motility , Spermatozoa , Male , Spermatozoa/drug effects , Calcium/metabolism , Sperm Motility/drug effects , Animals , Acrosome/drug effects , Lead/toxicity , Acrosome Reaction/drug effects , Cyclic AMP/metabolism , Cattle , Membrane Potential, Mitochondrial/drug effects , Signal Transduction/drug effects , Semen Analysis , DNA Damage/drug effects , Organometallic Compounds/toxicity , Organometallic Compounds/pharmacology
7.
PeerJ ; 12: e17582, 2024.
Article in English | MEDLINE | ID: mdl-39006025

ABSTRACT

Background: Disruptions in calcium homeostasis are associated with a wide range of diseases, and play a pivotal role in the development of cancer. However, the construction of prognostic models using calcium extrusion-related genes in colon adenocarcinoma (COAD) has not been well studied. We aimed to identify whether calcium extrusion-related genes serve as a potential prognostic biomarker in the COAD progression. Methods: We constructed a prognostic model based on the expression of calcium extrusion-related genes (SLC8A1, SLC8A2, SLC8A3, SLC8B1, SLC24A2, SLC24A3 and SLC24A4) in COAD. Subsequently, we evaluated the associations between the risk score calculated by calcium extrusion-related genes and mutation signature, immune cell infiltration, and immune checkpoint molecules. Then we calculated the immune score, stromal score, tumor purity and estimate score using the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm. The response to immunotherapy was assessed using tumor immune dysfunction and exclusion (TIDE). Finally, colorectal cancer cells migration, growth and colony formation assays were performed in RKO cells with the overexpression or knockdown SLC8A3, SLC24A2, SLC24A3, or SLC24A4. Results: We found that patients with high risk score of calcium extrusion-related genes tend to have a poorer prognosis than those in the low-risk group. Additionally, patients in high-risk group had higher rates of KRAS mutations and lower MUC16 mutations, implying a strong correlation between KRAS and MUC16 mutations and calcium homeostasis in COAD. Moreover, the high-risk group showed a higher infiltration of regulatory T cells (Tregs) in the tumor microenvironment. Finally, our study identified two previously unreported model genes (SLC8A3 and SLC24A4) that contribute to the growth and migration of colorectal cancer RKO cells. Conclusions: Altogether, we developed a prognostic risk model for predicting the prognosis of COAD patients based on the expression profiles of calcium extrusion-related genes, Furthermore, we validated two previously unreported tumor suppressor genes (SLC8A3 and SLC24A4) involved in colorectal cancer progression.


Subject(s)
Adenocarcinoma , Colonic Neoplasms , Humans , Prognosis , Colonic Neoplasms/genetics , Colonic Neoplasms/pathology , Colonic Neoplasms/mortality , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Adenocarcinoma/immunology , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Calcium/metabolism , Gene Expression Regulation, Neoplastic , Cell Line, Tumor , Male , Female , Mutation
8.
Front Immunol ; 15: 1391355, 2024.
Article in English | MEDLINE | ID: mdl-39007141

ABSTRACT

Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel that exhibits Ca2+ permeability. The TRPM2 channel is expressed in various tissues and cells and can be activated by multiple factors, including endogenous ligands, Ca2+, reactive oxygen species (ROS) and temperature. This article reviews the multiple roles of the TRPM2 channel in physiological and pathological processes, particularly on oxidative stress, inflammation and ischemia-reperfusion (I/R) injury. In oxidative stress, the excessive influx of Ca2+ caused by the activation of the TRPM2 channel may exacerbate cellular damage. However, under specific conditions, activating the TRPM2 channel can have a protective effect on cells. In inflammation, the activation of the TRPM2 channel may not only promote inflammatory response but also inhibit inflammation by regulating ROS production and bactericidal ability of macrophages and neutrophils. In I/R, the activation of the TRPM2 channel may worsen I/R injury to various organs, including the brain, heart, kidney and liver. However, activating the TRPM2 channel may protect the myocardium from I/R injury by regulating calcium influx and phosphorylating proline-rich tyrosine kinase 2 (Pyk2). A thorough investigation of the bidirectional role and regulatory mechanism of the TRPM2 channel in these physiological and pathological processes will aid in identifying new targets and strategies for treatment of related diseases.


Subject(s)
Inflammation , Oxidative Stress , Reperfusion Injury , TRPM Cation Channels , TRPM Cation Channels/metabolism , Humans , Reperfusion Injury/metabolism , Reperfusion Injury/immunology , Inflammation/metabolism , Inflammation/immunology , Animals , Reactive Oxygen Species/metabolism , Calcium/metabolism
9.
Biointerphases ; 19(4)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-39007691

ABSTRACT

Retinal degenerative diseases, which can lead to photoreceptor cell apoptosis, have now become the leading irreversible cause of blindness worldwide. In this study, we developed an organic photovoltaic biomaterial for artificial retinas, enabling neural cells to detect photoelectric stimulation. The biomaterial was prepared using a conjugated polymer donor, PCE-10, and a non-fullerene receptor, Y6, both known for their strong near-infrared light absorption capabilities. Additionally, a fullerene receptor, PC61BM, was incorporated, which possesses the ability to absorb reactive oxygen species. We conducted a comprehensive investigation into the microstructure, photovoltaic properties, and photothermal effects of this three-component photovoltaic biomaterial. Furthermore, we employed Rat adrenal pheochromocytoma cells (PC-12) as a standard neural cell model to evaluate the in vitro photoelectric stimulation effect of this photovoltaic biomaterial. The results demonstrate that the photovoltaic biomaterial, enriched with fullerene derivatives, can induce intracellular calcium influx in PC-12 cells under 630 nm (red light) and 780 nm (near-infrared) laser irradiation. Moreover, there were lower levels of oxidative stress and higher levels of mitochondrial activity compared to the non-PC61BM group. This photovoltaic biomaterial proves to be an ideal substrate for near-infrared photoelectrical stimulation of neural cells and holds promise for restoring visual function in patients with photoreceptor apoptosis.


Subject(s)
Biocompatible Materials , Fullerenes , Infrared Rays , Animals , Fullerenes/chemistry , Fullerenes/pharmacology , Rats , Biocompatible Materials/chemistry , PC12 Cells , Neurons/drug effects , Neurons/radiation effects , Calcium/metabolism , Calcium/chemistry
10.
PeerJ ; 12: e17333, 2024.
Article in English | MEDLINE | ID: mdl-38948204

ABSTRACT

Acute heart attack is the primary cause of cardiovascular-related death worldwide. A common treatment is reperfusion of ischemic tissue, which can cause irreversible damage to the myocardium. The number of mitochondria in cardiomyocytes is large, which generate adenosine triphosphate (ATP) to sustain proper cardiac contractile function, and mitochondrial dysfunction plays a crucial role in cell death during myocardial ischemia-reperfusion, leading to an increasing number of studies investigating the impact of mitochondria on ischemia-reperfusion injury. The disarray of mitochondrial dynamics, excessive Ca2+ accumulation, activation of mitochondrial permeable transition pores, swelling of mitochondria, ultimately the death of cardiomyocyte are the consequences of ischemia-reperfusion injury. κ-opioid receptors can alleviate mitochondrial dysfunction, regulate mitochondrial dynamics, mitigate myocardial ischemia-reperfusion injury, exert protective effects on myocardium. The mechanism of κ-OR activation during myocardial ischemia-reperfusion to regulate mitochondrial dynamics and reduce myocardial ischemia-reperfusion injury will be discussed, so as to provide theoretical basis for the protection of ischemic myocardium.


Subject(s)
Myocardial Reperfusion Injury , Myocytes, Cardiac , Receptors, Opioid, kappa , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/pathology , Receptors, Opioid, kappa/metabolism , Humans , Animals , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Mitochondria, Heart/metabolism , Mitochondria, Heart/pathology , Mitochondrial Dynamics/physiology , Calcium/metabolism
11.
Planta ; 260(2): 39, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38951320

ABSTRACT

MAIN CONCLUSION: Nitrogen stress altered important lipid parameters and related genes in Chlorella pyrenoidosa via ROS and Ca2+ signaling. The mutual interference between ROS and Ca2+ signaling was also uncovered. The changed mechanisms of lipid parameters (especially lipid classes and unsaturation of fatty acids) in microalgae are not completely well known under nitrogen stress. Therefore, Chlorella pyrenoidosa was exposed to 0, 0.5, 1 and 1.5 g L-1 NaNO3 for 4 days. Then, the physiological and biochemical changes were measured. It was shown that the total lipid contents, neutral lipid ratios as well as their related genes (accD and DGAT) increased obviously while the polar lipid ratios, degrees of unsaturation as well as their related genes (PGP and desC) decreased significantly in nitrogen stress groups. The obvious correlations supported that gene expressions should be the necessary pathways to regulate the lipid changes in C. pyrenoidosa under nitrogen stress. The changes in ROS and Ca2+ signaling as well as their significant correlations with corresponding genes and lipid parameters were analyzed. The results suggested that ROS and Ca2+ may regulate these gene expressions and lipid changes in C. pyrenoidosa under nitrogen stress conditions. This was verified by the subordinate tests with an ROS inhibitor and calcium reagents. It also uncovered the clues of mutual interference between ROS and Ca2+ signaling. To summarize, this study revealed the signaling pathways of important lipid changes in microalgae under N stress.


Subject(s)
Chlorella , Nitrogen , Reactive Oxygen Species , Stress, Physiological , Chlorella/metabolism , Chlorella/genetics , Chlorella/physiology , Reactive Oxygen Species/metabolism , Nitrogen/metabolism , Lipid Metabolism/genetics , Calcium/metabolism , Lipids , Calcium Signaling , Signal Transduction , Microalgae/metabolism , Microalgae/genetics
12.
Cell Biochem Funct ; 42(5): e4085, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38951992

ABSTRACT

This review rigorously investigates the early cerebral changes associated with Alzheimer's disease, which manifest long before clinical symptoms arise. It presents evidence that the dysregulation of calcium (Ca2+) homeostasis, along with mitochondrial dysfunction and aberrant autophagic processes, may drive the disease's progression during its asymptomatic, preclinical stage. Understanding the intricate molecular interplay that unfolds during this critical period offers a window into identifying novel therapeutic targets, thereby advancing the treatment of neurodegenerative disorders. The review delves into both established and emerging insights into the molecular alterations precipitated by the disruption of Ca2+ balance, setting the stage for cognitive decline and neurodegeneration.


Subject(s)
Alzheimer Disease , Autophagy , Calcium , Mitochondria , Mitophagy , Humans , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Mitochondria/metabolism , Mitochondria/pathology , Calcium/metabolism , Animals , Hemostasis , Homeostasis
13.
Environ Geochem Health ; 46(8): 283, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38963423

ABSTRACT

Phosphorus (P) scarcity and eutrophication have triggered the development of new materials for P recovery. In this work, a novel magnetic calcium-rich biochar nanocomposite (MCRB) was prepared through co-precipitation of crab shell derived biochar, Fe2+ and Fe3+. Characteristics of the material demonstrated that the MCRB was rich in calcite and that the Fe3O4 NPs with a diameter range of 18-22 nanometers were uniformly adhered on the biochar surface by strong ether linking (C-O-Fe). Batch tests demonstrated that the removal of P was pH dependent with an optimal pH of 3-7. The MCRB exhibited a superior P removal performance, with a maximum removal capacity of 105.6 mg g-1, which was even higher than the majority lanthanum containing compounds. Study of the removal mechanisms revealed that the P removal by MCRB involved the formation of hydroxyapatite (HAP-Ca5(PO4)3OH), electrostatic attraction and ligand exchange. The recyclability test demonstrated that a certain level (approximately 60%) was still maintained even after the six adsorption-desorption process, suggesting that MCRB is a promising material for P removal from wastewater.


Subject(s)
Charcoal , Nanocomposites , Phosphates , Water Pollutants, Chemical , Charcoal/chemistry , Nanocomposites/chemistry , Water Pollutants, Chemical/chemistry , Phosphates/chemistry , Adsorption , Hydrogen-Ion Concentration , Calcium/chemistry , Water Purification/methods , Wastewater/chemistry
14.
Proc Natl Acad Sci U S A ; 121(28): e2407066121, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38959038

ABSTRACT

Mammalian transglutaminases, a family of Ca2+-dependent proteins, are implicated in a variety of diseases. For example, celiac disease (CeD) is an autoimmune disorder whose pathogenesis requires transglutaminase 2 (TG2) to deamidate select glutamine residues in diet-derived gluten peptides. Deamidation involves the formation of transient γ-glutamyl thioester intermediates. Recent studies have revealed that in addition to the deamidated gluten peptides themselves, their corresponding thioester intermediates are also pathogenically relevant. A mechanistic understanding of this relevance is hindered by the absence of any structure of Ca2+-bound TG2. We report the X-ray crystallographic structure of human TG2 bound to an inhibitory gluten peptidomimetic and two Ca2+ ions in sites previously designated as S1 and S3. Together with additional structure-guided experiments, this structure provides a mechanistic explanation for how S1 regulates formation of an inhibitory disulfide bond in TG2, while also establishing that S3 is essential for γ-glutamyl thioester formation. Furthermore, our crystallographic findings and associated analyses have revealed that i) two interacting residues, H305 and E363, play a critical role in resolving the thioester intermediate into an isopeptide bond (transamidation) but not in thioester hydrolysis (deamidation); and ii) residues N333 and K176 stabilize preferred TG2 substrates and inhibitors via hydrogen bonding to nonreactive backbone atoms. Overall, the intermediate-state conformer of TG2 reported here represents a superior model to previously characterized conformers for both transition states of the TG2-catalyzed reaction.


Subject(s)
Calcium , GTP-Binding Proteins , Protein Glutamine gamma Glutamyltransferase 2 , Transglutaminases , Transglutaminases/metabolism , Transglutaminases/chemistry , Protein Glutamine gamma Glutamyltransferase 2/metabolism , Humans , Calcium/metabolism , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/chemistry , Crystallography, X-Ray , Glutens/metabolism , Glutens/chemistry , Models, Molecular , Protein Conformation , Celiac Disease/metabolism , Protein Binding
15.
J Cell Mol Med ; 28(13): e18509, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38957035

ABSTRACT

Pruritus is often accompanied with bacterial infections, but the underlying mechanism is not fully understood. Although previous studies revealed that lipopolysaccharides (LPS) could directly activate TRPV4 channel and TRPV4 is involved in the generation of both acute itch and chronic itch, whether and how LPS affects TRPV4-mediated itch sensation remains unclear. Here, we showed that LPS-mediated TRPV4 sensitization exacerbated GSK101-induced scratching behaviour in mice. Moreover, this effect was compromised in TLR4-knockout mice, suggesting LPS acted through a TLR4-dependent mechanism. Mechanistically, LPS enhanced GSK101-evoked calcium influx in mouse ear skin cells and HEK293T cells transfected with TRPV4. Further, LPS sensitized TRPV4 channel through the intracellular TLR4-PI3K-AKT signalling. In summary, our study found a modulatory role of LPS in TRPV4 function and highlighted the TLR4-TRPV4 interaction in itch signal amplification.


Subject(s)
Lipopolysaccharides , Phosphatidylinositol 3-Kinases , Pruritus , Signal Transduction , TRPV Cation Channels , Toll-Like Receptor 4 , TRPV Cation Channels/metabolism , TRPV Cation Channels/genetics , Animals , Toll-Like Receptor 4/metabolism , Pruritus/metabolism , Pruritus/chemically induced , Pruritus/pathology , Lipopolysaccharides/pharmacology , Humans , Mice , HEK293 Cells , Phosphatidylinositol 3-Kinases/metabolism , Mice, Knockout , Mice, Inbred C57BL , Male , Calcium/metabolism , Proto-Oncogene Proteins c-akt/metabolism
16.
Nat Commun ; 15(1): 5817, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38987270

ABSTRACT

Respiratory infections caused by the human fungal pathogen Aspergillus fumigatus are a major cause of mortality for immunocompromised patients. Exposure to these pathogens occurs through inhalation, although the role of the respiratory epithelium in disease pathogenesis has not been fully defined. Employing a primary human airway epithelial model, we demonstrate that fungal melanins potently block the post-translational secretion of the chemokines CXCL1 and CXCL8 independent of transcription or the requirement of melanin to be phagocytosed, leading to a significant reduction in neutrophil recruitment to the apical airway both in vitro and in vivo. Aspergillus-derived melanin, a major constituent of the fungal cell wall, dampened airway epithelial chemokine secretion in response to fungi, bacteria, and exogenous cytokines. Furthermore, melanin muted pathogen-mediated calcium fluxing and hindered actin filamentation. Taken together, our results reveal a critical role for melanin interaction with airway epithelium in shaping the host response to fungal and bacterial pathogens.


Subject(s)
Aspergillus fumigatus , Calcium , Chemokine CXCL1 , Interleukin-8 , Melanins , Melanins/metabolism , Humans , Interleukin-8/metabolism , Calcium/metabolism , Chemokine CXCL1/metabolism , Animals , Respiratory Mucosa/metabolism , Respiratory Mucosa/microbiology , Mice , Epithelial Cells/metabolism , Epithelial Cells/microbiology , Chemokines/metabolism , Mice, Inbred C57BL
17.
Nat Commun ; 15(1): 5819, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38987287

ABSTRACT

Hyperactivity mediated by synaptotoxic ß-amyloid (Aß) oligomers is one of the earliest forms of neuronal dysfunction in Alzheimer's disease. In the search for a preventive treatment strategy, we tested the effect of scavenging Aß peptides before Aß plaque formation. Using in vivo two-photon calcium imaging and SF-iGluSnFR-based glutamate imaging in hippocampal slices, we demonstrate that an Aß binding anticalin protein (Aß-anticalin) can suppress early neuronal hyperactivity and synaptic glutamate accumulation in the APP23xPS45 mouse model of ß-amyloidosis. Our results suggest that the sole targeting of Aß monomers is sufficient for the hyperactivity-suppressing effect of the Aß-anticalin at early disease stages. Biochemical and neurophysiological analyses indicate that the Aß-anticalin-dependent depletion of naturally secreted Aß monomers interrupts their aggregation to neurotoxic oligomers and, thereby, reverses early neuronal and synaptic dysfunctions. Thus, our results suggest that Aß monomer scavenging plays a key role in the repair of neuronal function at early stages of AD.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Disease Models, Animal , Hippocampus , Mice, Transgenic , Neurons , Animals , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Alzheimer Disease/genetics , Amyloid beta-Peptides/metabolism , Neurons/metabolism , Neurons/drug effects , Mice , Hippocampus/metabolism , Hippocampus/pathology , Humans , Male , Plaque, Amyloid/metabolism , Plaque, Amyloid/pathology , Glutamic Acid/metabolism , Mice, Inbred C57BL , Female , Calcium/metabolism , Synapses/metabolism , Synapses/drug effects
18.
Front Endocrinol (Lausanne) ; 15: 1395028, 2024.
Article in English | MEDLINE | ID: mdl-38989001

ABSTRACT

Introduction: Biphasic insulin secretion is an intrinsic characteristic of the pancreatic islet and has clinical relevance due to the loss of first-phase in patients with Type 2 diabetes. As it has long been shown that first-phase insulin secretion only occurs in response to rapid changes in glucose, we tested the hypothesis that islet response to an increase in glucose is a combination of metabolism plus an osmotic effect where hypertonicity is driving first-phase insulin secretion. Methods: Experiments were performed using perifusion analysis of rat, mouse, and human islets. Insulin secretion rate (ISR) and other parameters associated with its regulation were measured in response to combinations of D-glucose and membrane-impermeable carbohydrates (L-glucose or mannitol) designed to dissect the effect of hypertonicity from that of glucose metabolism. Results: Remarkably, the appearance of first-phase responses was wholly dependent on changes in tonicity: no first-phase in NAD(P)H, cytosolic calcium, cAMP secretion rate (cAMP SR), or ISR was observed when increased D-glucose concentration was counterbalanced by decreases in membrane-impermeable carbohydrates. When D-glucose was greater than 8 mM, rapid increases in L-glucose without any change in D-glucose resulted in first-phase responses in all measured parameters that were kinetically similar to D-glucose. First-phase ISR was completely abolished by H89 (a non-specific inhibitor of protein kinases) without affecting first-phase calcium response. Defining first-phase ISR as the difference between glucose-stimulated ISR with and without a change in hypertonicity, the peak of first-phase ISR occurred after second-phase ISR had reached steady state, consistent with the well-established glucose-dependency of mechanisms that potentiate glucose-stimulated ISR. Discussion: The data collected in this study suggests a new model of glucose-stimulated biphasic ISR where first-phase ISR derives from (and after) a transitory amplification of second-phase ISR and driven by hypertonicity-induced rise in H89-inhibitable kinases likely driven by first-phase responses in cAMP, calcium, or a combination of both.


Subject(s)
Glucose , Insulin Secretion , Insulin , Animals , Insulin Secretion/drug effects , Glucose/metabolism , Rats , Humans , Insulin/metabolism , Mice , Male , Islets of Langerhans/metabolism , Islets of Langerhans/drug effects , Cyclic AMP/metabolism , Calcium/metabolism
19.
Nutrients ; 16(13)2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38999874

ABSTRACT

A useful perioperative nutritional therapy for highly invasive esophageal cancer surgical cases needs to be developed. We clarified the usefulness of amino-acid-enriched nutritional therapy using glutamine (Gln)/arginine (Arg)/calcium ß-hydroxy-ß-methylbutyrate (HMB) products on the short-term postoperative outcomes of minimally invasive esophagectomy for esophageal cancer. Altogether, 114 patients (Gln/Arg/HMB group) received perioperative nutritional therapy with Gln/Arg/HMB products, and we retrospectively investigated the change in nutritional parameters including skeletal muscle mass, occurrence of postoperative complications, and short-term postoperative outcomes in this group. The results were compared between the Gln/Arg/HMB and control groups (79 patients not receiving the Gln/Arg/HMB products). The incidence of all postoperative complications, sputum expectoration disorder, and pleural effusion of grade ≥ III was significantly lower in the Gln/Arg/HMB group (62.0% vs. 38.6%, p = 0.001; 44.3% vs. 28.1%, p = 0.020; 27.8% vs. 13.2%, p = 0.011, respectively). The psoas muscle area and postoperative body weight were significantly higher at 1 month and 1 year after surgery in the Gln/Arg/HMB group than in the control group (93.5% vs. 99.9%, p < 0.001; 92.0% vs. 95.4%, p = 0.006). Perioperative amino-acid-enriched nutritional therapy may improve the short-term postoperative outcomes, nutritional status, and skeletal muscle mass of esophageal cancer surgical patients.


Subject(s)
Arginine , Esophageal Neoplasms , Esophagectomy , Glutamine , Perioperative Care , Postoperative Complications , Valerates , Humans , Male , Esophageal Neoplasms/surgery , Female , Arginine/administration & dosage , Retrospective Studies , Aged , Middle Aged , Valerates/administration & dosage , Postoperative Complications/prevention & control , Glutamine/administration & dosage , Perioperative Care/methods , Calcium , Nutrition Therapy/methods , Treatment Outcome , Nutritional Status , Muscle, Skeletal/drug effects
20.
Int J Mol Sci ; 25(13)2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38999980

ABSTRACT

We have previously reported that, in aortic rings, 18:1 lysophosphatidic acid (LPA) can induce both vasodilation and vasoconstriction depending on the integrity of the endothelium. The predominant molecular species generated in blood serum are poly-unsaturated LPA species, yet the vascular effects of these species are largely unexplored. We aimed to compare the vasoactive effects of seven naturally occurring LPA species in order to elucidate their potential pathophysiological role in vasculopathies. Vascular tone was measured using myography, and thromboxane A2 (TXA2) release was detected by ELISA in C57Bl/6 mouse aortas. The Ca2+-responses to LPA-stimulated primary isolated endothelial cells were measured by Fluo-4 AM imaging. Our results indicate that saturated molecular species of LPA elicit no significant effect on the vascular tone of the aorta. In contrast, all 18 unsaturated carbon-containing (C18) LPAs (18:1, 18:2, 18:3) were effective, with 18:1 LPA being the most potent. However, following inhibition of cyclooxygenase (COX), these LPAs induced similar vasorelaxation, primarily indicating that the vasoconstrictor potency differed among these species. Indeed, C18 LPA evoked a similar Ca2+-signal in endothelial cells, whereas in endothelium-denuded aortas, the constrictor activity increased with the level of unsaturation, correlating with TXA2 release in intact aortas. COX inhibition abolished TXA2 release, and the C18 LPA induced vasoconstriction. In conclusion, polyunsaturated LPA have markedly increased TXA2-releasing and vasoconstrictor capacity, implying potential pathophysiological consequences in vasculopathies.


Subject(s)
Aorta , Lysophospholipids , Mice, Inbred C57BL , Thromboxane A2 , Vasoconstriction , Animals , Thromboxane A2/metabolism , Vasoconstriction/drug effects , Mice , Lysophospholipids/metabolism , Lysophospholipids/pharmacology , Aorta/drug effects , Aorta/metabolism , Male , Endothelial Cells/metabolism , Endothelial Cells/drug effects , Vasodilation/drug effects , Calcium/metabolism
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