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1.
Asian J Androl ; 2024 May 10.
Article in English | MEDLINE | ID: mdl-38738948

ABSTRACT

ABSTRACT: For sperm cryopreservation, the conventional method, which requires glycerol, has been used for a long time. In addition, the permeable cryoprotectant-free vitrification method has been continuously studied. Although the differences of cryopreservation effects between the two methods have being studied, differences in microRNA (miRNA) profiles between them remain unclear. In this study, we investigated the differences in miRNA expression profiles among conventional freezing sperm, droplet vitrification freezing sperm and fresh human sperm. We also analyzed the differences between these methods in terms of differentially expressed miRNAs (DEmiRs) related to early embryonic development and paternal epigenetics. Our results showed no significant differences between the cryopreservation methods in terms of sperm motility ratio, plasma membrane integrity, DNA integrity, mitochondrial membrane potential, acrosome integrity, and ultrastructural damage. However, sperm miRNA-sequencing showed differences between the two methods in terms of the numbers of DEmiRs (28 and 19 with vitrification using a nonpermeable cryoprotectant and the conventional method, respectively) in postthaw and fresh sperm specimens. DEmiRs related to early embryonic development and paternal epigenetics mainly included common DEmiRs between the groups. Our results showed that the differences between conventional freezing and droplet vitrification were minimal in terms of miRNA expression related to embryonic development and epigenetics. Changes in sperm miRNA expression due to freezing are not always detrimental to embryonic development. This study compared differences in miRNA expression profiles before and after cryopreservation between cryopreservation by conventional and vitrification methods. It offers a new perspective to evaluate various methods of sperm cryopreservation.

2.
Nat Commun ; 14(1): 6921, 2023 10 30.
Article in English | MEDLINE | ID: mdl-37903816

ABSTRACT

Ca2+ signal-generation through inter-membrane junctional coupling between endoplasmic reticulum (ER) STIM proteins and plasma membrane (PM) Orai channels, remains a vital but undefined mechanism. We identify two unusual overlapping Phe-His aromatic pairs within the STIM1 apical helix, one of which (F394-H398) mediates important control over Orai1-STIM1 coupling. In resting STIM1, this locus is deeply clamped within the folded STIM1-CC1 helices, likely near to the ER surface. The clamped environment in holo-STIM1 is critical-positive charge replacing Phe-394 constitutively unclamps STIM1, mimicking store-depletion, negative charge irreversibly locks the clamped-state. In store-activated, unclamped STIM1, Phe-394 mediates binding to the Orai1 channel, but His-398 is indispensable for transducing STIM1-binding into Orai1 channel-gating, and is spatially aligned with Phe-394 in the exposed Sα2 helical apex. Thus, the Phe-His locus traverses between ER and PM surfaces and is decisive in the two critical STIM1 functions-unclamping to activate STIM1, and conformational-coupling to gate the Orai1 channel.


Subject(s)
Calcium Signaling , Calcium , Stromal Interaction Molecule 1/genetics , Stromal Interaction Molecule 1/metabolism , ORAI1 Protein/genetics , ORAI1 Protein/metabolism , Calcium/metabolism , Cell Membrane/metabolism , Calcium Signaling/physiology
3.
Article in English | MEDLINE | ID: mdl-37317920

ABSTRACT

BACKGROUND: STIM- and Orai-mediated store operated calcium entry (SOCE) is a ubiquitous Ca2+ signaling process, crucial for the proper function of immune, muscle and neuronal systems. To treat SOCE-related disorder or diseases of these systems, and to mechanistically dissect activation and function of SOCE, specific SOCE inhibitors are needed. However, strategies for developing new SOCE modifiers are still limited.

Methodology: In this study, we identified a novel SOCE inhibitor named 2PHDO from a small pool of Chinese herbal extracts used for treating psoriasis. It could block SOCE and SOCE-mediated NFAT translocation in multiple types of cells with a half inhibitory concentration around 1 µM. At this concentration, 2PHDO was specific for SOCE. Mechanistically, 2PHDO didn't affect the activation of STIM1 or its physical coupling with Orai1. Rather, 2PHDO inhibited SOCE via its actions on Orai1.

Results: 2PHDO may serve as a good template for developing new medicines aiming to treat SOCE related diseases.

Conclusion: Overall, we proved the feasibility of screening and identification of novel SOCE inhibitors from active monomers of Chinese herbal medicine.

4.
Cell Calcium ; 112: 102735, 2023 06.
Article in English | MEDLINE | ID: mdl-37126912

ABSTRACT

The STIM-Orai signaling pathway mediates Ca2+ signals vital for controlling transcription and cell growth. The Ca2+ sensing STIM proteins are activated by depletion of Ca2+ stored in the ER, and translocate into ER-PM junctions to gate PM Orai channels. STIM1 activation also results from heating STIM1 proteins, and new evidence reveals the STIM1-mediated gating of Orai1 channels is activated by noxious cooling of cells. This activation of the STIM-Orai pathway may be important in mediating vascular dilation that occurs in response to severe cold exposure.


Subject(s)
Calcium Signaling , Signal Transduction , ORAI1 Protein/metabolism , Stromal Interaction Molecule 1/metabolism , Calcium Signaling/physiology , Calcium/metabolism
5.
Cancers (Basel) ; 15(9)2023 Apr 23.
Article in English | MEDLINE | ID: mdl-37173886

ABSTRACT

Cell-cell communication, either through direct contact or indirectly, is critical for multiple cellular processes, such as proliferation, survival, differentiation, and transdifferentiation, and it plays a fundamental role in maintaining the integrity of tissue structure and cellular environment [...].

6.
Front Pharmacol ; 14: 1111798, 2023.
Article in English | MEDLINE | ID: mdl-36817139

ABSTRACT

Introduction: Psoriasis is an inflammatory autoimmune skin disease that is hard to cure and prone to relapse. Currently available global immunosuppressive agents for psoriasis may cause severe side effects, thus it is crucial to identify new therapeutic reagents and druggable signaling pathways for psoriasis. Methods: To check the effects of SOCE inhibitors on psoriasis, we used animal models, biochemical approaches, together with various imaging techniques, including calcium, confocal and FRET imaging. Results and discussion: Store operated calcium (Ca2+) entry (SOCE), mediated by STIM1 and Orai1, is crucial for the function of keratinocytes and immune cells, the two major players in psoriasis. Here we showed that a natural compound celastrol is a novel SOCE inhibitor, and it ameliorated the skin lesion and reduced PASI scores in imiquimod-induced psoriasis-like mice. Celastrol dose- and time-dependently inhibited SOCE in HEK cells and HaCaT cells, a keratinocyte cell line. Mechanistically, celastrol inhibited SOCE via its actions both on STIM1 and Orai1. It inhibited Ca2+ entry through constitutively-active Orai1 mutants independent of STIM1. Rather than blocking the conformational switch and oligomerization of STIM1 during SOCE activation, celastrol diminished the transition from oligomerized STIM1 into aggregates, thus locking STIM1 in a partially active state. As a result, it abolished the functional coupling between STIM1 and Orai1, diminishing SOCE signals. Overall, our findings identified a new SOCE inhibitor celastrol that suppresses psoriasis, suggesting that SOCE pathway may serve as a new druggable target for treating psoriasis.

7.
Clin Otolaryngol ; 47(6): 664-671, 2022 11.
Article in English | MEDLINE | ID: mdl-36073732

ABSTRACT

OBJECTIVE: To investigate the associations between weekly alcohol consumption and the risk and surgical outcome of Chronic Rhinosinusitis (CRS). DESIGN: A case-control study. SETTING AND PARTICIPANTS: The study population consisted of 1095 CRS patients and 909 healthy collected from the first affiliated hospital of Zhengzhou University between May 2018 and December 2019. MAIN OUTCOME MEASURES: Unconditional multivariate logistic regression analysis and Cox proportional hazards regression analysis were performed to estimate the association of alcohol consumption with the risk and surgical outcomes of CRS. Odds ratios (OR) or hazard ratio (HR) with 95% confidence intervals (CI) were calculated separately. The Kruskal-Wallis test was used to explore the possible molecular mechanisms. RESULTS: As compared with nondrinkers, the multivariable-adjusted OR (95% CI) values of current drinkers consuming 7.5-22 drinks and >22 drinks per week were 2.158 (1.249-3.729) and 5.373 (2.912-9.911), respectively. The rate of mucosal epithelialization after CRS surgery for patients who drank 7.5-22 drinks and >22 drinks per week was lower than that of nondrinkers [HR (95% CI) = 0.487 (0.351-0.675) and 0.252 (0.184-0.346), respectively]. The association of alcohol consumption with the risk and surgical outcome of CRS was dose dependent (p < .01). Alcohol consumption increased the risk of CRS and extended the time of mucosal epithelialization after CRS surgery by possibly increasing serum IgE levels (p < .05). CONCLUSION: Higher alcohol consumption of >7.5 drinks per week was an independent risk factor for CRS and extended the time of mucosal epithelialization after surgery. As a potential underlying mechanism, alcohol consumption increases serum IgE levels.


Subject(s)
Alcohol Drinking , Immunoglobulin E , Alcohol Drinking/adverse effects , Alcohol Drinking/epidemiology , Case-Control Studies , China/epidemiology , Humans , Prospective Studies , Risk Factors , Treatment Outcome
9.
Cell Rep ; 35(13): 109322, 2021 06 29.
Article in English | MEDLINE | ID: mdl-34192542

ABSTRACT

Junctional coupling between endoplasmic reticulum (ER) Ca2+-sensor STIM proteins and plasma membrane (PM) Orai channels mediates Ca2+ signals in most cells. We reveal that PM-tethered, fluorescently tagged C-terminal M4x (fourth transmembrane helix contains a cytoplasmic C-terminal extension) peptides from Orai channels undergo a Leu-specific signature of direct interaction with the STIM1 Orai-activating region (SOAR), exactly mimicking STIM1 binding to gate Orai channels. The 20-amino-acid Orai3-M4x peptide associates avidly with STIM1 within ER-PM junctions, functions to competitively block native Ca2+ signals, and mediates a key modification of STIM-Orai coupling induced by 2-aminoethoxydiphenyl borate. By blocking STIM-Orai coupling, the Orai3-M4x peptide reveals the critical role of Orai channels in driving Ca2+ oscillatory signals and transcriptional control through NFAT. The M4x peptides interact independently with SOAR dimers consistent with unimolecular coupling between Orai subunits and STIM1 dimers. We reveal the critical role of M4x helices in defining the coupling interface between STIM and Orai proteins to mediate store-operated Ca2+ signals.


Subject(s)
Calcium Signaling , ORAI1 Protein/chemistry , ORAI1 Protein/metabolism , Peptides/metabolism , Stromal Interaction Molecule 1/metabolism , Amino Acid Sequence , Binding Sites , Boron Compounds/pharmacology , Calcium Channels/metabolism , Cell Membrane/metabolism , Cytosol/metabolism , Endoplasmic Reticulum/metabolism , HEK293 Cells , HeLa Cells , Humans , Ion Channel Gating , Leucine/metabolism , Models, Molecular , Mutation/genetics , NFATC Transcription Factors/metabolism , Protein Binding , Protein Multimerization , Transcription, Genetic/drug effects
11.
Curr Opin Physiol ; 17: 106-114, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32954113

ABSTRACT

Store-operated Ca2+ entry signals are critical for cellular regulation. This intricate signaling pathway involves coupling of proteins in two different membranes: the ER-resident Ca2+-sensing STIM proteins and the highly Ca2+-selective PM Orai channels. The molecular nature of the STIM-Orai coupling interface in ER-PM junctions and consequent Orai channel gating, are processes under intense study. We describe recent developments in determining the mechanism of Orai activation through the key STIM-Orai Activating Region (SOAR) of STIM1. We describe the unexpected unimolecular coupling of STIM with Orai and explain the observed variable stoichiometry of STIM-Orai interactions. We also define the discrete C-terminal regions in Orai channels that initially latch onto STIM proteins and mediate allosteric activation of the channel. A critical "nexus" region closely associated with the STIM-activated C-terminus of Orai1, propagates the STIM-binding signal through the four tightly-associated transmembrane helices of Orai1, finally to modify the pore-forming helices and effect channel opening.

12.
Nat Commun ; 11(1): 3351, 2020 07 03.
Article in English | MEDLINE | ID: mdl-32620897

ABSTRACT

The sodium-leak channel NALCN forms a subthreshold sodium conductance that controls the resting membrane potentials of neurons. The auxiliary subunits of the channel and their functions in mammals are largely unknown. In this study, we demonstrate that two large proteins UNC80 and UNC79 are subunits of the NALCN complex. UNC80 knockout mice are neonatal lethal. The C-terminus of UNC80 contains a domain that interacts with UNC79 and overcomes a soma-retention signal to achieve dendritic localization. UNC80 lacking this domain, as found in human patients, still supports whole-cell NALCN currents but lacks dendritic localization. Our results establish the subunit composition of the NALCN complex, uncover the inter-subunit interaction domains, reveal the functional significance of regulation of dendritic membrane potential by the sodium-leak channel complex, and provide evidence supporting that genetic variations found in individuals with intellectual disability are the causes for the phenotype observed in patients.


Subject(s)
Carrier Proteins/genetics , Intellectual Disability/genetics , Ion Channels/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Nerve Tissue Proteins/genetics , Animals , Carrier Proteins/metabolism , Child , DNA Mutational Analysis , Datasets as Topic , Dendrites/pathology , Disease Models, Animal , Gene Knock-In Techniques , HEK293 Cells , Hippocampus/cytology , Hippocampus/pathology , Humans , Intellectual Disability/diagnosis , Intellectual Disability/pathology , Ion Channels/genetics , Male , Mice , Mice, Knockout , Mutation , Nerve Tissue Proteins/metabolism , Primary Cell Culture , Protein Domains/genetics , Severity of Illness Index , Exome Sequencing
13.
Cells ; 9(2)2020 01 22.
Article in English | MEDLINE | ID: mdl-31979185

ABSTRACT

Being the largest the Ca2+ store in mammalian cells, endoplasmic reticulum (ER)-mediated Ca2+ signalling often involves both Ca2+ release via inositol 1, 4, 5-trisphosphate receptors (IP3R) and store operated Ca2+ entries (SOCE) through Ca2+ release activated Ca2+ (CRAC) channels on plasma membrane (PM). IP3Rs are functionally coupled with CRAC channels and other Ca2+ handling proteins. However, it still remains less well defined as to whether IP3Rs could regulate ER-mediated Ca2+ signals independent of their Ca2+ releasing ability. To address this, we generated IP3Rs triple and double knockout human embryonic kidney (HEK) cell lines (IP3Rs-TKO, IP3Rs-DKO), and systemically examined ER Ca2+ dynamics and CRAC channel activity in these cells. The results showed that the rate of ER Ca2+ leakage and refilling, as well as SOCE were all significantly reduced in IP3Rs-TKO cells. And these TKO effects could be rescued by over-expression of IP3R3. Further, results showed that the diminished SOCE was caused by NEDD4L-mediated ubiquitination of Orai1 protein. Together, our findings indicate that IP3R3 is one crucial player in coordinating ER-mediated Ca2+ signalling.


Subject(s)
Calcium/metabolism , Endoplasmic Reticulum/metabolism , Inositol 1,4,5-Trisphosphate Receptors/metabolism , Calcium Signaling , Cell Movement , Cell Proliferation , HEK293 Cells , Humans , Nedd4 Ubiquitin Protein Ligases/metabolism , ORAI1 Protein/metabolism , Protein Isoforms/metabolism
14.
Front Immunol ; 10: 2421, 2019.
Article in English | MEDLINE | ID: mdl-31681309

ABSTRACT

Wound healing-promoting peptides exhibit excellent therapeutic potential in regenerative medicine. However, amphibian-derived wound healing-promoting peptides and their mechanism of action remain to be further elucidated. We hereby characterized a wound healing-promoting peptide, Ot-WHP, derived from Chinese concave-eared frog Odorrana tormota. It efficiently promoted wound healing in a mouse model of full-thickness wounds. Ot-WHP significantly increased the number of neutrophils in wounds, and modestly promoted neutrophil phagocytosis and phorbol myristate acetate (PMA)-induced neutrophil extracellular trap formation. Ot-WHP also significantly increased the number of macrophages in wound sites, and directly induced chemokine, cytokine and growth factor production in macrophages by activating mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) signaling pathways. Of note, Ot-WHP did not act as a chemoattractant for neutrophils and macrophages, suggesting its chemotactic activity depends on inducing chemoattractant production in macrophages. Besides, Ot-WHP directly promoted keratinocyte migration by enhancing integrin expression and cell adhesion. In addition, Ot-WHP significantly enhanced the cross-talk between macrophages and keratinocytes/fibroblasts by promoting keratinocyte/fibroblast proliferation, and fibroblast-to-myofibroblast transition despite having no direct effects on keratinocyte/fibroblast proliferation, and fibroblast differentiation. Collectively, Ot-WHP directly elicited the production of regulatory factors in macrophages, consequently initiated and accelerated the inflammatory phase by recruiting neutrophils and macrophages to wounds, and in turn enhanced the cross-talk between macrophages and keratinocytes/fibroblasts, additionally promoted keratinocyte migration, and finally promoted cutaneous wound healing. Our findings provide a promising immunomodulator for acute wound management and new clues for understanding the mechanism of action of amphibian-derived wound healing-promoting peptides.


Subject(s)
Anura , Immunologic Factors/pharmacology , Peptides/pharmacology , Amino Acid Sequence , Animals , Base Sequence , Biomarkers/metabolism , Chemotaxis, Leukocyte/immunology , Collagen/metabolism , Cytokines/metabolism , Disease Models, Animal , Fibroblasts/metabolism , Immunologic Factors/chemistry , Immunologic Factors/isolation & purification , Keratinocytes/metabolism , Macrophages/immunology , Macrophages/metabolism , Mice , Myofibroblasts/metabolism , NF-kappa B/metabolism , Neutrophils/immunology , Neutrophils/metabolism , Peptides/chemistry , Peptides/isolation & purification , Signal Transduction/drug effects , Skin/injuries , Skin/pathology , Wound Healing/drug effects
15.
PLoS Biol ; 17(8): e3000413, 2019 08.
Article in English | MEDLINE | ID: mdl-31469825

ABSTRACT

Calcium signals drive an endless array of cellular responses including secretion, contraction, transcription, cell division, and growth. The ubiquitously expressed Orai family of plasma membrane (PM) ion channels mediate Ca2+ entry signals triggered by the Ca2+ sensor Stromal Interaction Molecule (STIM) proteins of the endoplasmic reticulum (ER). The 2 proteins interact within curiously obscure ER-PM junctions, driving an allosteric gating mechanism for the Orai channel. Although key to Ca2+ signal generation, molecular understanding of this activation process remain obscure. Crystallographic structural analyses reveal much about the exquisite hexameric core structure of Orai channels. But how STIM proteins bind to the channel periphery and remotely control opening of the central pore, has eluded such analysis. Recent studies apply both crystallography and single-particle cryogenic electron microscopy (cryo-EM) analyses to probe the structure of Orai mutants that mimic activation by STIM. The results provide new understanding on the open state of the channel and how STIM proteins may exert remote allosteric control of channel gating.


Subject(s)
Calcium Channels , Calcium , Calcium Signaling , ORAI1 Protein , Stromal Interaction Molecule 1
16.
17.
J Biol Chem ; 294(16): 6318-6332, 2019 04 19.
Article in English | MEDLINE | ID: mdl-30824535

ABSTRACT

Store-operated Ca2+ entry (SOCE) is a ubiquitous pathway for Ca2+ influx across the plasma membrane (PM). SOCE is mediated by the endoplasmic reticulum (ER)-associated Ca2+-sensing proteins stromal interaction molecule 1 (STIM1) and STIM2, which transition into an active conformation in response to ER Ca2+ store depletion, thereby interacting with and gating PM-associated ORAI1 channels. Although structurally homologous, STIM1 and STIM2 generate distinct Ca2+ signatures in response to varying strengths of agonist stimulation. The physiological functions of these Ca2+ signatures, particularly under native conditions, remain unclear. To investigate the structural properties distinguishing STIM1 and STIM2 activation of ORAI1 channels under native conditions, here we used CRISPR/Cas9 to generate STIM1-/-, STIM2-/-, and STIM1/2-/- knockouts in HEK293 and colorectal HCT116 cells. We show that depending on cell type, STIM2 can significantly sustain SOCE in response to maximal store depletion. Utilizing the SOCE modifier 2-aminoethoxydiphenyl borate (2-APB), we demonstrate that 2-APB-activated store-independent Ca2+ entry is mediated exclusively by endogenous STIM2. Using variants that either stabilize or disrupt intramolecular interactions of STIM C termini, we show that the increased flexibility of the STIM2 C terminus contributes to its selective store-independent activation by 2-APB. However, STIM1 variants with enhanced flexibility in the C terminus failed to support its store-independent activation. STIM1/STIM2 chimeric constructs indicated that coordination between N-terminal sensitivity and C-terminal flexibility is required for specific store-independent STIM2 activation. Our results clarify the structural determinants underlying activation of specific STIM isoforms, insights that are potentially useful for isoform-selective drug targeting.


Subject(s)
Calcium Signaling , Calcium/metabolism , Endoplasmic Reticulum/metabolism , Stromal Interaction Molecule 2/metabolism , Boron Compounds/chemistry , Boron Compounds/pharmacology , Calcium/chemistry , Endoplasmic Reticulum/chemistry , Endoplasmic Reticulum/genetics , Gene Knockdown Techniques , HCT116 Cells , HEK293 Cells , Humans , Neoplasm Proteins/chemistry , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Protein Domains , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , Stromal Interaction Molecule 1/chemistry , Stromal Interaction Molecule 1/genetics , Stromal Interaction Molecule 1/metabolism , Stromal Interaction Molecule 2/chemistry , Stromal Interaction Molecule 2/genetics
18.
J Cell Mol Med ; 23(3): 1687-1697, 2019 03.
Article in English | MEDLINE | ID: mdl-30636376

ABSTRACT

Tissue damage and its associated-inflammation act as tumour initiators or propagators. AMP-activated protein kinase (AMPK) is activated by environmental or nutritional stress factors, such as hypoxia, glucose deprivation, and other cell injury factors, to regulate cell energy balance and differentiation. We previously have reported that AMPKα2 deficiency resulted in the energy deprivation in tumour-bearing liver and the enhanced-hepatocyte death. In this study, AMPKα2 knockout mice and the liver metastasis model of colon cancer cells were used to address the role of AMPKα isoforms in tumour inflammation. First, we found that the AMPKα2 deficiency exacerbated the liver injury and recruitment of macrophages. Meanwhile, although compensatory expression of AMPKα1 was not significant after AMPKα2 knockout, AMPKα1 phosphorylation was elevated in remnant liver in AMPKα2 knockout mice, which was positively associated with the enhanced energy deprivation in the AMPKα2 deficient mice. Furthermore, the activated AMPKα1 in macrophage contributed to its polarizing to tumour-associated phenotype. Thus, the enhanced tumour-associated inflammation and activation of AMPKα1 in the AMPKα2 deficient mice may exacerbate the tumour development by affecting the tumour inflammatory microenvironment. Our study suggests that the two isoforms of AMPKα, AMPKα1 and AMPKα2 play different roles in controlling tumour development.


Subject(s)
AMP-Activated Protein Kinases/physiology , Colonic Neoplasms/etiology , Disease Models, Animal , Inflammation/etiology , Liver Neoplasms/etiology , Macrophages/pathology , Animals , Cell Differentiation , Cells, Cultured , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Energy Metabolism , Inflammation/metabolism , Inflammation/pathology , Liver Neoplasms/metabolism , Liver Neoplasms/secondary , Macrophages/immunology , Macrophages/metabolism , Mice , Mice, Knockout , Phosphorylation , Tumor Microenvironment
19.
Parasit Vectors ; 11(1): 470, 2018 Aug 14.
Article in English | MEDLINE | ID: mdl-30107813

ABSTRACT

BACKGROUND: Mosquitoes are armed with physiologically active compounds to suppress the host immunity including host inflammatory reaction. However, the specific anti-inflammatory components in mosquitoes remain unknown. RESULTS: By searching for the immunomodulatory molecules from the mosquito Aedes aegypti (Diptera: Culicidae) at NCBI for anti-inflammatory function, five cecropins (for short in this study: AeaeCec1, 2, 3, 4 and 5) were selected. AeaeCec1-5 efficiently inhibited the expression of inducible nitric oxide synthase (iNOS), nitrite, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages and human peripheral blood mononuclear cells (PBMCs) with low toxicity to mammalian cells. Among the five analogues, AeaeCec5 had the strongest anti-inflammatory activity, and generated an additive effect with other AeaeCec peptides. In a mouse model of endotoxin shock, AeaeCec1-5 effectively reduced TNF-α, IL-1ß and IL-6 expression in lungs, serum and peritoneal lavage and correspondingly reduced lung damage and edema, with AeaeCec5 showing the best protection. In mice infected with Escherichia coli or Pseudomonas aeruginosa, administration of AeaeCec5 reduced the production of TNF-α, IL-1ß and IL-6 and correspondingly reduced lung tissue damage. These effects of Ae. aegypti AeaeCec1-5 were attributed to an efficient inhibition of the activation of mitogen-activated protein kinases (MAPKs) and transcriptional nuclear factor-κB (NF-κB) signaling pathways, as well as partial neutralization of LPS. CONCLUSIONS: The current work characterized the specific anti-inflammatory agents in Ae. aegypti and provided AeaeCec5 as a potent anti-endotoxin peptide that could serve as the basis for the development of anti-inflammatory therapy.


Subject(s)
Aedes/chemistry , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/pharmacology , Cecropins/immunology , Shock, Septic/prevention & control , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/isolation & purification , Bacterial Infections/drug therapy , Bacterial Infections/immunology , Cecropins/administration & dosage , Cecropins/chemistry , Cecropins/pharmacology , Humans , Immunologic Factors/administration & dosage , Immunologic Factors/chemistry , Immunologic Factors/isolation & purification , Immunologic Factors/pharmacology , Interleukin-1beta/drug effects , Interleukin-1beta/genetics , Interleukin-6/genetics , Leukocytes, Mononuclear/drug effects , Lipopolysaccharides/pharmacology , Macrophages, Peritoneal/drug effects , Mice , Mitogen-Activated Protein Kinases/drug effects , Nitric Oxide Synthase Type II/drug effects , Nitric Oxide Synthase Type II/genetics , Shock, Septic/immunology , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/drug effects , Tumor Necrosis Factor-alpha/genetics
20.
Pflugers Arch ; 470(10): 1555-1567, 2018 10.
Article in English | MEDLINE | ID: mdl-29934936

ABSTRACT

Mediated through the combined action of STIM proteins and Orai channels, store-operated Ca2+ entry (SOCE) functions ubiquitously among different cell types. The existence of multiple STIM and Orai genes has made it difficult to assign specific roles of each STIM and Orai homolog in mediating Ca2+ signals. Using CRISPR/Cas9 gene editing tools, we generated cells with both STIM or all three Orai homologs deleted and directly monitored store Ca2+ and Ca2+ signals. We found that unstimulated, SOCE null KO cells still retain 50~70% of ER Ca2+ stores of wildtype (wt) cells. After brief exposure to store-emptying conditions, acute refilling of ER Ca2+ stores was totally blocked in KO cells. However, after 24 h in culture, stores were eventually refilled. Thus, SOCE is critical for immediate refilling of ER Ca2+ but is dispensable for the maintenance of long-term ER Ca2+ homeostasis. Using the Orai null background triple Orai-KO cells, we examined the plasma membrane translocation properties of a series of truncated STIM1 variants. FRET analysis reveals that, even though PM tethering of STIM1 expedites the activation of STIM1 by facilitating its oligomerization, migration, and accumulation in ER-PM junctions, it is not required for the conformational switch, oligomerization, and clustering of STIM1. Even without overt puncta formation at ER-PM junctions, STIM11-491 and STIM11-666 could still rescue SOCE when expressed in STIM KO cells. Thus, ER-PM trapping and clustering of STIM molecules only facilitates the process of SOCE activation, but is not essential for the activation of Orai channels.


Subject(s)
Calcium Signaling , ORAI1 Protein/deficiency , Stromal Interaction Molecule 1/deficiency , Cell Membrane/metabolism , Endoplasmic Reticulum/metabolism , HEK293 Cells , Humans , ORAI1 Protein/genetics , Protein Multimerization , Protein Transport , Stromal Interaction Molecule 1/genetics
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