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1.
PLoS One ; 19(4): e0300249, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573994

RESUMO

The effects of jogi (the fish Atlantic croaker, Micropogonias undulatus) on the production of physicochemical components, such as color, organic acids, and amino acids, in kimchi, a traditional fermented vegetable food of Korea, were determined. As fermentation progressed, the color change of jogi-added kimchi increased, but in comparison with that of the control group without jogi-added kimchi, was difficult to distinguish with the naked eye. Reducing sugar decreased in all experimental groups, and as fermentation progressed, kimchi with jogi showed a lower value. Acetic acid, citric acid, lactic acid, and ethanol, were highly produced in both types of kimchi, and above all, the jogi-baechu-kimchi group showed higher acetic acid and lactic acid contents than the control group. The increase and decrease of amino acids were similar in both types of kimchi. However, significantly, immediately after manufacture, the savory components aspartic acid and glutamic acid were detected higher than the control group. Subsequently, the fermentation tended to decrease as it progressed, but the content was higher than that of the control group. The above results show that jogi addition has a greater effect on the contents of amino acid, especially the savory component, than on the physicochemical components.


Assuntos
Alimentos Fermentados , Perciformes , Animais , Aminoácidos , Fermentação , Ácido Láctico , Acetatos , Microbiologia de Alimentos
2.
Heliyon ; 10(5): e25263, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38495172

RESUMO

Attention toward the preventive effects of postbiotics on metabolic diseases has increased because of greater stability and safety over probiotics. However, studies regarding the bioactive effects of postbiotics, especially from probiotic Bacillus strains, are relatively limited. The anti-obesity effects of the cell-free culture supernatant of Bacillus velezensis KMU01 (CFS-B.vele) were evaluated using high-fat-diet (HFD)-induced mice. HFD-induced mice (n = 8 per group) received equal volumes of (1) CFS-B.vele (114 mg/kg) in PBS, (2) Xenical in PBS, or (3) PBS alone by oral gavage daily for 13 weeks. The results demonstrated that CFS-B.vele changed the gut microbiota and showed anti-obesity effects in HFD-induced obese mice. The elevated Firmicutes/Bacteroidota ratio induced by HFD was decreased in the CFS-B.vele group compared to the other groups (p < 0.05). The CFS-B.vele intervention led to the enrichment of SCFA-producers, such as Roseburia and Eubacterium, in the cecum, suggesting their potential involvement in the amelioration of obesity. Due to these changes, the various obesity-related biomarkers (body weight, fat in tissue, white adipose tissue weight and size, serum LDL-cholesterol level, hepatic lipid accumulation, and adipogenesis/lipogenesis-related gene/protein expression) were improved. Our findings suggest that CFS-B.vele has potential as a novel anti-obesity agent through modulation of the gut microbiota.

3.
Dent Traumatol ; 39(6): 565-574, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37530064

RESUMO

BACKGROUND/AIM: Owing to the nearly three-year-long COVID-19 pandemic, small personal transportation devices that allow for greater freedom of movement within the cities have gained attention. Therefore, the number of people using kick or electric scooters has increased. This study aimed to compare the characteristics of kick and electric scooter-related dental and maxillofacial trauma and provide helpful information for preventing scooter accidents, appropriate treatment of patients with scooter-related trauma, and policy establishment. MATERIALS AND METHODS: This retrospective observational study analysed the medical records of 310 patients who visited the emergency room of Ajou University Dental Hospital for kick and electric scooter-related oral and maxillofacial injuries between 1 January 2017 and 31 December 2022. Sex, age, scooter type, time, and mechanism of the accident, helmet use, alcohol consumption, dental and maxillofacial injury types, and treatment were analysed. RESULTS: The average age in the kick-scooter group (5.71 ± 4.25) was lower than that in the electric-scooter group (28.24 ± 10.02) (p < .0001). There were more males in both groups. The helmet usage rates of the two groups were 2.80% and 7.88%, respectively. In the kick-scooter group, periodontal damage was more common than pulp injury, while in the electric-scooter group, pulp injury was more common than periodontal injury. There was no significant difference in soft-tissue damage between the two groups; however, bone fractures occurred significantly more frequently in the electric-scooter group (p < .0001). CONCLUSIONS: Electric scooters cause more crown and bone fractures than kick scooters and require more active treatment of dental and maxillofacial injuries. Riders should use protective equipment to prevent dental and maxillofacial injury. Although there are regulations related to scooters, the effectiveness of both kick- and electric-scooter related laws needs to be evaluated.


Assuntos
Fraturas Ósseas , Traumatismos Maxilofaciais , Humanos , Masculino , Fraturas Ósseas/epidemiologia , Dispositivos de Proteção da Cabeça , Traumatismos Maxilofaciais/epidemiologia , Traumatismos Maxilofaciais/etiologia , Pandemias , Estudos Retrospectivos , Feminino , Pré-Escolar , Criança
4.
Nutrients ; 15(13)2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37447355

RESUMO

The purpose of this study was to investigate the effect that Glycine max hydrolyzed with enzymes from Bacillus velezensis KMU01 has on dextran-sulfate-sodium (DSS)-induced colitis in mice. Hydrolysis improves functional health through the bioconversion of raw materials and increase in intestinal absorption rate and antioxidants. Therefore, G. max was hydrolyzed in this study using a food-derived microorganism, and its anti-inflammatory effect was observed. Enzymatically hydrolyzed G. max (EHG) was orally administered once daily for four weeks before DSS treatment. Colitis was induced in mice through the consumption of 5% (w/v) DSS in drinking water for eight days. The results showed that EHG treatment significantly alleviated DSS-induced body weight loss and decreased the disease activity index and colon length. In addition, EHG markedly reduced tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6 production, and increased that of IL-10. EHG improved DSS-induced histological changes and intestinal epithelial barrier integrity in mice. Moreover, we found that the abundance of 15 microorganisms changed significantly; that of Proteobacteria and Escherichia coli, which are upregulated in patients with Crohn's disease and ulcerative colitis, decreased after EHG treatment. These results suggest that EHG has a protective effect against DSS-induced colitis and is a potential candidate for colitis treatment.


Assuntos
Colite Ulcerativa , Colite , Camundongos , Animais , Glycine max , Dextranos/efeitos adversos , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/patologia , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/patologia , Colo , Anti-Inflamatórios/uso terapêutico , Sulfatos , Sódio/efeitos adversos , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
5.
Am J Physiol Cell Physiol ; 325(1): C42-C51, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37212545

RESUMO

Transient receptor potential channels canonical 1 and 4 (TRPC1 and TRPC4) are proteins belonging to the same TRPC channel family, and the two are known to form a heterotetrameric channel. TRPC4 can form a homotetrameric, nonselective cation channel by itself, but the involvement of the TRPC1 subunit changes several major characteristics of the channel. In this study, we focused on the pore region (selectivity filter, pore helix, and S6 helix) of TRPC1 and TRPC4 as a determinant of the identity and characteristics of a heteromeric TRPC1/4 channel: decreased calcium permeability of the channel and outward-rectifying current-voltage (I-V) curve. Mutants and chimeras of the pore residues were created, and their currents were recorded using whole cell patch clamp. The lower gate mutants of TRPC4 exhibited diminished calcium permeability as measured by GCaMP6 fluorescence. Also, chimeric channels substituting the pore region of TRPC1 to TRPC4 were made to locate the pore region that is critical in the production of an outward-rectifying I-V curve characteristic of TRPC1/4 heteromeric channels.NEW & NOTEWORTHY Heteromer research has been a challenging field due to lack of structural studies. Using chimeras and single mutants, we present evidence that the pore region of TRPC1/4 heteromer contributes to determining the channel's characteristics such as calcium permeability, I-V curve, and conductance.


Assuntos
Multimerização Proteica , Humanos , Células HEK293 , Modelos Moleculares , Estrutura Terciária de Proteína , Cálcio/metabolismo , Canais de Cátion TRPC/química , Estrutura Quaternária de Proteína , Ativação do Canal Iônico , Membrana Celular/química
6.
Nat Commun ; 14(1): 2550, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37137991

RESUMO

G-protein coupled receptors (GPCRs) and ion channels serve as key molecular switches through which extracellular stimuli are transformed into intracellular effects, and it has long been postulated that ion channels are direct effector molecules of the alpha subunit of G-proteins (Gα). However, no complete structural evidence supporting the direct interaction between Gα and ion channels is available. Here, we present the cryo-electron microscopy structures of the human transient receptor potential canonical 5 (TRPC5)-Gαi3 complexes with a 4:4 stoichiometry in lipid nanodiscs. Remarkably, Gαi3 binds to the ankyrin repeat edge of TRPC5 ~ 50 Å away from the cell membrane. Electrophysiological analysis shows that Gαi3 increases the sensitivity of TRPC5 to phosphatidylinositol 4,5-bisphosphate (PIP2), thereby rendering TRPC5 more easily opened in the cell membrane, where the concentration of PIP2 is physiologically regulated. Our results demonstrate that ion channels are one of the direct effector molecules of Gα proteins triggered by GPCR activation-providing a structural framework for unraveling the crosstalk between two major classes of transmembrane proteins: GPCRs and ion channels.


Assuntos
Canais de Potencial de Receptor Transitório , Humanos , Microscopia Crioeletrônica , Receptores Acoplados a Proteínas G/metabolismo , Membrana Celular/metabolismo , Canais de Cátion TRPC/metabolismo
7.
Korean J Physiol Pharmacol ; 27(2): 187-196, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36815258

RESUMO

Transient receptor potential canonical (TRPC) channels are non-selective calcium-permeable cation channels. It is suggested that TRPC4ß is regulated by phospholipase C (PLC) signaling and is especially maintained by phosphatidylinositol 4,5-bisphosphate (PIP2). In this study, we present the regulation mechanism of the TRPC4 channel with PIP2 hydrolysis which is mediated by a channel-bound PLCδ1 but not by the GqPCR signaling pathway. Our electrophysiological recordings demonstrate that the Ca2+ via an open TRPC4 channel activates PLCδ1 in the physiological range, and it causes the decrease of current amplitude. The existence of PLCδ1 accelerated PIP2 depletion when the channel was activated by an agonist. Interestingly, PLCδ1 mutants which have lost the ability to regulate PIP2 level failed to reduce the TRPC4 current amplitude. Our results demonstrate that TRPC4 self-regulates its activity by allowing Ca2+ ions into the cell and promoting the PIP2 hydrolyzing activity of PLCδ1.

8.
J Microbiol ; 61(12): 1063-1073, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38165607

RESUMO

The consumption of fresh produce has led to increase in antibiotic-resistant (AR) Salmonella outbreaks. In this study, indigenous Salmonella was isolated from a total of two hundred-two samples including fresh produce and agricultural environmental samples in Korea. After biochemical confirmation using the Indole, Methyl Red, Voges-Proskauer, Citrate tests, presumable Salmonella isolates were identified by 16S rRNA sequencing. Identified Salmonella isolates were evaluated for antibiotic susceptibility against twenty-two antibiotics. The specificity and the efficiency of plating (EOP) of vB_SalS_KFSSM were evaluated against fifty-three bacterial strains. Twenty-five suspected Salmonella were isolated and confirmed by the positive result for methyl red and citrate, of which ten were identified as Salmonella spp. through 16S rRNA gene sequencing. Eight Salmonella isolates (4.0%, n = 8/202) were resistant to at least one antibiotic, among which five were multi-drug resistant. As a lytic phage against Salmonella spp. CMGS-1, vB_SalS_KFSSM was isolated from cow manure. The phage was observed as a tailed phage belonging to the class Caudoviricetes. It exhibited an intra-broad specificity against four indigenous AR Salmonella isolates, two indigenous Salmonella isolates, and five other Salmonella serotypes with great efficiencies (EOP ≥ 0.75). Thus, this study suggested the potential of vB_SalS_KFSSM to combat indigenous AR Salmonella.


Assuntos
Antibacterianos , Bacteriófagos , Antibacterianos/farmacologia , Sais , Prevalência , RNA Ribossômico 16S/genética , Salmonella , Cloreto de Sódio , Citratos
9.
J Microbiol Biotechnol ; 32(5): 612-620, 2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35283424

RESUMO

Recent studies have revealed that probiotics and their metabolites are present under various conditions; however, the role of probiotic metabolites (i.e., postbiotics in pathological states) is controversial. Natural killer (NK) cells play a key role in innate and adaptive immunity. In this study, we examined NK cell activation influenced by a postbiotics mixture in response to gut microbiome modulation in stress-induced mice. In vivo activation of NK cells increased in the postbiotics mixture treatment group in accordance with Th1/Th2 expression level. Meanwhile, the Red Ginseng treatment group, a reference group, showed very little expression of NK cell activation. Moreover, the postbiotics mixture treatment group in particular changed the gut microbiome composition. Although the exact role of the postbiotics mixture in regulating the immune system of stress-induced mice remains unclear, the postbiotics mixture-induced NK cell activation might have affected gut microbiome modulation.


Assuntos
Microbioma Gastrointestinal , Probióticos , Imunidade Adaptativa , Animais , Microbioma Gastrointestinal/fisiologia , Células Matadoras Naturais , Camundongos , Prebióticos , Probióticos/metabolismo , Probióticos/farmacologia
10.
J Microbiol Biotechnol ; 32(3): 341-347, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35001009

RESUMO

In this study, the bacterial community of galchi-baechu kimchi was determined using culture-based and culture-independent techniques (next generation sequencing:NGS), and showed discrepancies between results. Weissella koreensis and Pediococcus inopinatus were the dominant species according to the NGS results, while Bacillus species and P. inopinatus were dominant in the culture-dependent analysis. To identify safe starter candidates, sixty-five Bacillus strains isolated from galchi-baechu kimchi using culture-dependent methods were evaluated for their antibiotic resistance, presence of toxin genes, and hemolytic activity. Strains were then assessed for salt tolerance and protease and lipase activity. As a result, four strains-B. safensis GN5_10, B. subtilis GN5_19, B. velezensis GN5_25, and B. velezensis GT8-were selected as safe starter candidates for use in fermented foods.


Assuntos
Bacillus , Alimentos Fermentados , Bacillus/genética , Bactérias/genética , Fermentação , Microbiologia de Alimentos
11.
Foods ; 10(8)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34441683

RESUMO

Bacillus siamensis strain B28 was previously isolated from traditional Korean fermented kimchi and inhibited expression of the microphthalmia-associated transcription factor and ß-catenin in human embryonic kidney 293 cells. Here, we determined the complete genome sequence of strain B28 and compared it with other strains to elucidate its potential probiotic properties. Strain B28 does not contain antibiotic resistance-, hemolysin- or enterotoxin-encoding genes. The genome includes genes related to survival in extreme conditions, adhesion in the gut, and synthesis of the bacteriocin. Considering the potential for enhancement of human health, the strain B28 genome encodes genes related to production of eight essential amino acids, γ-aminobutyric acid, branched-chain fatty acids, γ-glutamyltransferase, and subtilisin. There are genes for the synthesis of uracil, lipoteichoic acid, glutathione, and several reactive oxygen species-scavenging enzymes. Experimentally, strain B28 exhibited sensitivity to eight antibiotics and antibacterial activity against seven foodborne pathogens. B. siamensis B28 is a safe strain with potential for development as a probiotic.

12.
Foods ; 10(3)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803098

RESUMO

Bacillus velezensis strain KMU01 showing γ-glutamyltransferase activity as a probiotic candidate was isolated from kimchi. However, the genetic information on strain KMU01 was not clear. Therefore, the current investigation was undertaken to prove the probiotic traits of B. velezensis strain KMU01 through genomic analysis. Genomic analysis revealed that strain KMU01 did not encode enterotoxin genes and acquired antibiotic resistance genes. Strain KMU01 genome possessed survivability traits under extreme conditions such as in the presence of gastric acid, as well as several probiotic traits such as intestinal epithelium adhesion and the production of thiamine and essential amino acids. Potential genes for human health enhancement such as those for γ-glutamyltransferase, nattokinase, and bacteriocin production were also identified in the genome. As a starter candidate for food fermentation, the genome of KMU01 encoded for protease, amylase, and lipase genes. The complete genomic sequence of KMU01 will contribute to our understanding of the genetic basis of probiotic properties and allow for the assessment of the effectiveness of this strain as a starter or probiotic for use in the food industry.

13.
Biochim Biophys Acta Mol Cell Res ; 1867(2): 118620, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31812495

RESUMO

Protein S-palmitoylation, the covalent lipid modification of the side chain of Cys residues with the 16­carbon fatty acid palmitate, is the most common acylation, and it enhances the membrane stability of ion channels. This post-translational modification (PTM) determines a functional mechanism of ion channel life cycle from maturation and membrane trafficking to localization. Especially, neurodevelopment is regulated by balancing the level of synaptic protein palmitoylation/depalmitoylation. Recently, we revealed the pathological role of the transient receptor potential canonical type 5 (TRPC5) channel in striatal neuronal loss during Huntington's disease (HD), which is abnormally activated by oxidative stress. Here, we report a mechanism of TRPC5 palmitoylation at a conserved cysteine residue, that is critical for intrinsic channel activity. Furthermore, we identified the therapeutic effect of TRPC5 depalmitoylation by enhancing the TRPC5 membrane instability on HD striatal cells in order to lower TRPC5 toxicity. Collectively, these findings suggest that controlling S-palmitoylation of the TRPC5 channel as a potential risk factor can modulate TRPC5 channel expression and activity, providing new insights into a therapeutic strategy for neurodegenerative diseases.


Assuntos
Neurônios/metabolismo , Estresse Oxidativo , Canais de Cátion TRPC/metabolismo , Motivos de Aminoácidos , Animais , Antineoplásicos Alquilantes/toxicidade , Apoptose/efeitos dos fármacos , Carmustina/toxicidade , Complexo de Golgi/metabolismo , Células HEK293 , Humanos , Proteína Huntingtina/genética , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Lipoilação/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Mutagênese Sítio-Dirigida , Estresse Oxidativo/efeitos dos fármacos , Palmitatos/farmacologia , Estabilidade Proteica , Subunidades Proteicas/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Canais de Cátion TRPC/química , Canais de Cátion TRPC/genética
14.
Korean J Physiol Pharmacol ; 23(5): 357-366, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31496873

RESUMO

Gαq-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate (PI(4,5)P2) depletion. When PI(4,5)P2 depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon Gαq-phospholipase C ß (Gαq-PLCß) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in PLCß activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by Ca2+ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic Ca2+ due to Ca2+ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following PI(4,5)P2 depletion.

15.
J Microbiol Biotechnol ; 29(7): 1078-1082, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31280528

RESUMO

Poly-γ-glutamate (γ-PGA) has various applications due to its desirable characteristics in terms of safety and biodegradability. Previous studies have been conducted on γ-PGA hydrogels produced by γ-ray irradiation, but these hydrogels have proved unstable in solutions. This study was conducted to enable the γ-PGA hydrogel to maintain a stable form in solutions. The γ-PGA mixture for UV-irradiation was prepared with a cross-linker (N,N,N-trimethyl-3-[(2- methylacryloyl)amino]propan-1-aminium). Both γ-PGA hydrogels' characteristics, including stability in solutions, were examined. The UV-irradiated γ-PGA hydrogel maintained a stable form during the nine weeks of the study, but the γ-ray irradiated hydrogel dissolved after one week.


Assuntos
Raios gama , Hidrogéis/química , Ácido Poliglutâmico/análogos & derivados , Raios Ultravioleta , Materiais Biocompatíveis/química , Reagentes de Ligações Cruzadas/química , Hidrogéis/síntese química , Concentração de Íons de Hidrogênio , Ácido Poliglutâmico/química , Soluções , Viscosidade
16.
Pflugers Arch ; 471(8): 1045-1053, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31222490

RESUMO

Transient receptor potential canonical (TRPC) channels are calcium permeable, non-selective cation channels with wide tissue-specific distribution. Among 7 TRPC channels, TRPC 1/4/5 and TRPC3/6/7 are subdivided based on amino acid sequence homology. TRPC4 and TRPC5 channels exhibit cationic current with homotetrameric form, but they also form heterotetrameric channel such as TRPC1/4 or TRPC1/5 once TRPC1 is incorporated. The expression of TRPC1 is ubiquitous whereas the expressions of TRPC4 and TRPC5 are rather focused in nervous system. With the help of conditional knock-out of TPRC1, 4 and/or 5 genes, TRPC channels made of these constituents are reported to be involved in various pathophysiological functions such as seizure, anxiety-like behaviour, fear, Huntington's disease, Parkinson's disease and many others. In heterologous expression system, many issues such as activation mechanism, stoichiometry and relative cation permeabilites of homomeric or heteromeric channels have been addressed. In this review, we discussed the role of TRPC1 channel per se in plasma membrane, role of TRPC1 in heterotetrameric conformation (TRPC1/4 or TRPC1/5) and relationship between TRPC1/4/5 channels, calcium influx and voltage-gated calcium channels.


Assuntos
Neurônios/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Humanos , Potenciais da Membrana , Neurônios/fisiologia , Multimerização Proteica , Canais de Cátion TRPC/química , Canais de Cátion TRPC/genética
17.
Korean J Physiol Pharmacol ; 23(3): 219-227, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31080352

RESUMO

Polycystic kidney disease 2-like-1 (PKD2L1), polycystin-L or transient receptor potential polycystin 3 (TRPP3) is a TRP superfamily member. It is a calcium-permeable non-selective cation channel that regulates intracellular calcium concentration and thereby calcium signaling. Although the calmodulin (CaM) inhibitor, calmidazolium, is an activator of the PKD2L1 channel, the activating mechanism remains unclear. The purpose of this study is to clarify whether CaM takes part in the regulation of the PKD2L1 channel, and if so, how. With patch clamp techniques, we observed the current amplitudes of PKD2L1 significantly reduced when coexpressed with CaM and CaMΔN. This result suggests that the N-lobe of CaM carries a more crucial role in regulating PKD2L1 and guides us into our next question on the different functions of two lobes of CaM. We also identified the predicted CaM binding site, and generated deletion and truncation mutants. The mutants showed significant reduction in currents losing PKD2L1 current-voltage curve, suggesting that the C-terminal region from 590 to 600 is crucial for maintaining the functionality of the PKD2L1 channel. With PKD2L1608Stop mutant showing increased current amplitudes, we further examined the functional importance of EF-hand domain. Along with co-expression of CaM, ΔEF-hand mutant also showed significant changes in current amplitudes and potentiation time. Our findings suggest that there is a constitutive inhibition of EF-hand and binding of CaM C-lobe on the channel in low calcium concentration. At higher calcium concentration, calcium ions occupy the N-lobe as well as the EF-hand domain, allowing the two to compete to bind to the channel.

18.
Sci Rep ; 8(1): 12117, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30108272

RESUMO

The transient receptor potential canonical (TRPC) 1 channel is widely distributed in mammalian cells and is involved in many physiological processes. TRPC1 is primarily considered a regulatory subunit that forms heterotetrameric channels with either TRPC4 or TRPC5 subunits. Here, we suggest that the regulation of TRPC1/4 and TRPC1/5 heterotetrameric channels by the Gαq-PLCß pathway is self-limited and dynamically mediated by Gαq and PI(4,5)P2. We provide evidence indicating that Gαq protein directly interacts with either TRPC4 or TRPC5 of the heterotetrameric channels to permit activation. Simultaneously, Gαq-coupled PLCß activation leads to the breakdown of PI(4,5)P2, which inhibits activity of TRPC1/4 and 1/5 channels.


Assuntos
Multimerização Proteica/fisiologia , Transdução de Sinais/fisiologia , Canais de Cátion TRPC/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Humanos , Técnicas de Patch-Clamp , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfolipase C beta/metabolismo
19.
Sci Rep ; 8(1): 3480, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29472562

RESUMO

Hypertension and aneurysm are frequently associated with autosomal dominant polycystic kidney disease (ADPKD) caused by polycystin-1 (PC1) mutations, which is closely related to endothelial dysfunction. PC1 is an atypical G-protein-coupled receptor that activates G-proteins by self-cleavage; currently, however, the molecular and cellular mechanisms of the associated intracellular signaling and ion channel activation remain poorly elucidated. Here, we report an activation mechanism of a calcium-permeable canonical transient receptor potential 4 (TRPC4) channel by PC1 and its endothelial function. We found that the inhibitory Gαi3 protein selectively bound to the G-protein-binding domain on the C-terminus of PC1. The dissociation of Gαi3 upon cleavage of PC1 increased TRPC4 activity. Calcium influx through TRPC4 activated the transcription factor STAT1 to regulate cell proliferation and death. The down-regulation of PC1/TRPC4/STAT1 disrupted migration of endothelial cell monolayers, leading to an increase in endothelial permeability. These findings contribute to greater understanding of the high risk of aneurysm in patients with ADPKD.


Assuntos
Aneurisma/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Rim Policístico Autossômico Dominante/genética , Canais de Cátion TRPC/genética , Canais de Cátion TRPP/genética , Aneurisma/etiologia , Aneurisma/patologia , Apoptose/genética , Cálcio/metabolismo , Movimento Celular , Proliferação de Células/genética , Endotélio/metabolismo , Endotélio/patologia , Células HEK293 , Humanos , Hipertensão/etiologia , Hipertensão/genética , Hipertensão/patologia , Rim Policístico Autossômico Dominante/complicações , Rim Policístico Autossômico Dominante/patologia , Fatores de Risco , Fator de Transcrição STAT1/genética
20.
J Microbiol Biotechnol ; 28(4): 527-533, 2018 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-29385660

RESUMO

This study compared the radioprotective effects of high-molecular-weight poly-gamma-glutamate (γ-PGA, average molecular mass 3,000 kDa) and a reduced form of glutathione (GSH, a known radioprotector) on calf thymus DNA damage. The radiation-induced DNA damage was measured on the basis of the decreased fluorescence intensity after binding the DNA with ethidium bromide. All the experiments used 6°Co gamma radiation at 1,252 Gy, representing 50% DNA damage. When increasing the concentration of γ-PGA from 0.33 to 1.65 µM, the DNA protection from radiation-induced damage also increased, with a maximum of 87% protection. Meanwhile, the maximal DNA protection when increasing the concentration of GSH was only 70%. Therefore, γ-PGA exhibited significant radioprotective effects against gamma irradiation.


Assuntos
Cosmecêuticos/farmacologia , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Raios gama/efeitos adversos , Glutamatos/farmacologia , Protetores contra Radiação/farmacologia , Cosmecêuticos/administração & dosagem , Cosmecêuticos/química , DNA/efeitos dos fármacos , DNA/efeitos da radiação , Radicais Livres/efeitos adversos , Glutamatos/administração & dosagem , Glutamatos/química , Glutationa/metabolismo , Protetores contra Radiação/administração & dosagem , Protetores contra Radiação/química , Espectrometria de Fluorescência
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