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1.
Food Sci Biotechnol ; 33(4): 769-790, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38371680

ABSTRACT

Whey, a major by-product of cheese production, is primarily composed of whey protein (WP). To mitigate environmental pollution, it is crucial to identify effective approaches for fully utilizing the functional components of whey or WP to produce high-value-added products. This review aims to illustrate the active substances with immunomodulatory, metabolic syndrome-regulating, antioxidant, antibacterial, and anti-inflammatory activities produced by whey or WP through fermentation processes, and summarizes the application and the effects of whey or WP on nutritional properties and health promotion in fermented foods. All these findings indicate that whey or WP can serve as a preservative, a source of high-protein dietary, and a source of physiologically active substance in the production of fermented foods. Therefore, expanding the use of whey or WP in fermented foods is of great importance for converting whey into value-added products, as well as reducing whey waste and potential contamination.

2.
Mol Ecol Resour ; 22(3): 1178-1189, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34689424

ABSTRACT

Fagaceae species are increasingly used as models to elucidate the process and mechanism of adaptation and speciation by integrating ecology, evolution and genomics. The genus Castanopsis belongs to the family Fagaceae and is mainly distributed across subtropical and tropical Asia. In the present study, we reported the first chromosome-scale genome assembly of Castanopsis tibetana, a common species of evergreen broadleaved forests in subtropical China. The combination of Nanopore sequencing and Hi-C technologies enabled a high-quality genome assembly. The final assembled genome size of C. tibetana was 878.6 Mb (97.6% of the estimated genome size), consisting of 477 contigs with an N50 length of 3.3 Mb. The benchmarking universal single-copy orthologue (BUSCO) assessment indicated a completeness of 93.0%. Hi-C scaffolding generated 12 pseudochromosomes, representing 98.7% of the assembled genome. Subsequently, 40,937 protein-coding genes were predicted and 90.04% of them were functionally annotated. More than 476.9 Mb of repetitive sequences (54.3% of the genome) were identified, and the percentage of the genome covered by TE elements was 39.98%. Comparative genomics analysis revealed that C. tibetana was most closely related to Castanea mollissima and diverged at 18.48 Ma, and that C. tibetana has undergone considerable gene family expansion and contraction. Evidence of positive selection was detected in 53 genes, which showed different arrangement pattern compared to Quercus robur. The chromosome-scale genome assembly of C. tibetana will expand Fagaceae genome resources across the family and provide a powerful comparative framework to study the adaptation and evolution of Fagaceae trees.


Subject(s)
Fagaceae , Trees , Chromosomes , Fagaceae/genetics , Genome , Molecular Sequence Annotation , Phylogeny , Trees/genetics
3.
J Mol Cell Cardiol ; 164: 110-125, 2022 03.
Article in English | MEDLINE | ID: mdl-34774547

ABSTRACT

Effects of hypertrophic challenge on small-conductance, Ca2+-activated K+(SK2) channel expression were explored in intact murine hearts, isolated ventricular myocytes and neonatal rat cardiomyocytes (NRCMs). An established experimental platform applied angiotensin II (Ang II) challenge in the presence and absence of reduced p21-activated kinase (PAK1) (PAK1cko vs. PAK1f/f, or shRNA-PAK1 interference) expression. SK2 current contributions were detected through their sensitivity to apamin block. Ang II treatment increased such SK2 contributions to optically mapped action potential durations (APD80) and their heterogeneity, and to patch-clamp currents. Such changes were accentuated in PAK1cko compared to PAK1f/f, intact hearts and isolated cardiomyocytes. They paralleled increased histological and echocardiographic hypertrophic indices, reduced cardiac contractility, and increased SK2 protein expression, changes similarly greater with PAK1cko than PAK1f/f. In NRCMs, Ang II challenge replicated such increases in apamin-sensitive SK patch clamp currents as well as in real-time PCR and western blot measures of SK2 mRNA and protein expression and cell hypertrophy. Furthermore, the latter were enhanced by shRNA-PAK1 interference and mitigated by the PAK1 agonist FTY720. Increased CaMKII and CREB phosphorylation accompanied these effects. These were rescued by both FTY720 as well as the CaMKII inhibitor KN93, but not its inactive analogue KN92. Such CREB then specifically bound to the KCNN2 promoter sequence in luciferase assays. These findings associate Ang II induced hypertrophy with increased SK2 expression brought about by a CaMKII/CREB signaling convergent with the PAK1 pathway thence upregulating the KCNN2 promoter activity. SK2 may then influence cardiac electrophysiology under conditions of cardiac hypertrophy and failure.


Subject(s)
Angiotensin II , p21-Activated Kinases , Angiotensin II/metabolism , Angiotensin II/pharmacology , Animals , Apamin/metabolism , Apamin/pharmacology , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Cardiomegaly/metabolism , Fingolimod Hydrochloride/metabolism , Fingolimod Hydrochloride/pharmacology , Mice , Myocytes, Cardiac/metabolism , Protein Serine-Threonine Kinases , RNA, Small Interfering/metabolism , Rats , Up-Regulation , p21-Activated Kinases/genetics , p21-Activated Kinases/metabolism , p21-Activated Kinases/pharmacology
4.
Epigenomics ; 14(22): 1411-1425, 2022 11.
Article in English | MEDLINE | ID: mdl-36695107

ABSTRACT

Aim: To explore the effect of the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (Aza) on early renal injury. Materials & methods: Cell damage and inflammation are features of early renal injury. The apoptosis and inflammation in hypoxia/reoxygenation (H/R)-induced human proximal tubular epithelial cells (HK-2) and ischemia-reperfusion kidney were studied, and expression of the protein klotho was investigated. Results: Aza induced HK-2 apoptosis in a dose-dependent manner, but low-dose Aza attenuated the apoptosis and inflammation in H/R-induced HK-2 cells and ischemia-reperfusion kidney. Low-dose Aza ameliorated renal function in mice with renal ischemia-reperfusion injury. Meanwhile, low-dose Aza upregulated klotho expression in H/R-induced HK-2 cells and ischemia-reperfusion kidney. Klotho knockdown abrogated the effects of low-dose Aza on apoptosis and inflammation. Conclusion: Low-dose Aza protects against renal early injury by increasing klotho expression.


DNA methylation affects kidney disease and might be a clinically useful therapeutic target for kidney disease. It has been reported that blocking DNA methylation may reduce renal fibrosis. Early renal injury is a priming event of late renal function failure, and inhibition of early renal injury may be beneficial to prevent late loss of function. In this study, the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine was studied for its effects on cell apoptosis and inflammation in early renal injury. Low-dose 5-aza-2'-deoxycytidine had antiapoptotic and anti-inflammatory effects on HK-2 cells induced by hypoxia/reoxygenation and renal tissue with ischemia­reperfusion injury (IRI), and improved renal function following renal IRI. Possible mechanisms involved reduced methylation of klotho promoter DNA and upregulation of klotho expression. Therefore, it is attractive to speculate that preventing DNA methylation may be an effective strategy or method to attenuate renal early injury or renal IRI in human patients, as it is in rodents.


Subject(s)
Apoptosis , Kidney , Humans , Mice , Animals , Decitabine/pharmacology , Kidney/metabolism , Ischemia/metabolism , Inflammation/metabolism
5.
Int J Stem Cells ; 14(4): 410-422, 2021 Nov 30.
Article in English | MEDLINE | ID: mdl-34158418

ABSTRACT

BACKGROUND AND OBJECTIVES: Manipulating different signaling pathways via small molecules could efficiently induce cardiomyocytes from human induced pluripotent stem cells (hiPSC). However, the effect of transcription factors on the hiPSC-directed cardiomyocytes differentiation remains unclear. Transcription factor, p53 has been demonstrated indispensable for the early embryonic development and mesendodermal differentiation of embryonic stem cells (ESC). We tested the hypothesis that p53 promotes cardiomyocytes differentiation from human hiPSC. METHODS AND RESULTS: Using the well-characterized GiWi protocol that cardiomyocytes are generated from hiPSC via temporal modulation of Wnt signaling pathway by small molecules, we demonstrated that forced expression of p53 in hiPSC remarkably improved the differentiation efficiency of cardiomyocytes from hiPSC, whereas knockdown endogenous p53 decreased the yield of cardiomyocytes. This p53-mediated increased cardiomyocyte differentiation was mediated through WNT3, as evidenced by that overexpression of p53 upregulated the expression of WNT3, and knockdown of p53 decreased the WNT3 expression. Mechanistic analysis showed that the increased cardiomyocyte differentiation partially depended on the amplified mesendodermal specification resulted from p53-mediated activation of WNT3-mediated Wnt signaling. Consistently, endogenous WNT3 knockdown significantly ameliorated mesendodermal specification and subsequent cardiomyocyte differentiation. CONCLUSIONS: These results provide a novel insight into the potential effect of p53 on the development and differentiation of cardiomyocyte during embryogenesis.

6.
Gerontology ; 67(3): 323-337, 2021.
Article in English | MEDLINE | ID: mdl-33752204

ABSTRACT

INTRODUCTION: Vasoconstriction is triggered by an increase in intracellular-free calcium concentration. Growing evidence indicates that contraction is also regulated by calcium-independent mechanisms involving RhoA-Rho kinase (ROCK), protein kinase C (PKC), and so on. In this study, we studied the changes of vascular reactivity as well as the underlying signaling pathways in aging spontaneously hypertensive rats (SHRs). METHODS: The artery tension induced by α1-adrenergic receptor activator (α1-AR) phenylephrine (PE) was measured in the absence or presence of myosin light chain kinase (MLCK), PKC, and ROCK inhibitors. The α1-AR, PKC, ROCK, phosphorylation of myosin light chain (MLC), and PKC-potentiated phosphatase inhibitors of 17 kDa (CPI-17) of rat mesenteric arteries were analyzed at the mRNA level or protein level. RESULTS: The vascular tension measurements showed that there was a significant increase in the mesenteric artery contraction induced by PE in old SHR. MLCK inhibitor ML-7 can similarly inhibit PE-induced vasoconstriction. PKC inhibitor GF109203X has the weakest inhibitory effect on PE-induced contraction in old SHR. At the presence of ROCK inhibitor H1152, PE-induced contraction was significantly reduced in young Wistar-Kyoto (WKY) rats, but this phenomenon disappeared in other rats. Furthermore, in old SHR the protein expression of α1-AR decreased and phosphorylation of MLC and CPI-17 were upregulated and MLC phosphatase (MLCP) activity was significantly lower. The expressions of PKC were upregulated in SHR and old rats. In addition, the expression of ROCK-1 was decreased and ROCK-2 was significantly upregulated with age in SHR. CONCLUSION: In aging hypertension, the expression/activity of PKC or ROCK-2/CPI-17 excessively increased, MLCP activity decreased and MLC phosphorylation enhanced, leading to increased α1-AR-induced vasoconstriction.


Subject(s)
Hypertension , Muscle Proteins , Aging , Animals , Mesenteric Arteries , Phosphoproteins , Rats , Rats, Inbred WKY
7.
Front Psychol ; 12: 792167, 2021.
Article in English | MEDLINE | ID: mdl-35082728

ABSTRACT

Based on conversations between 10 Chinese children with Autism Spectrum Disorders (ASD) and five therapists in the context of Naturalistic Intervention, this study investigated the therapists' agreement expressions in this typical setting. The study found that (1) the therapists mainly used four agreement strategies: acknowledgment, positive evaluation, repetition and blending. These four strategies could be used individually or in combination. The first three strategies and their combinations were used frequently during the therapeutic conversation. (2) With the major occurrences in the post-expansion position, the agreement expressions in the therapeutic conversation mainly performed three functions, namely, creating a supportive therapeutic relationship, serving as positive reinforcers and implementing interventions pertinent to communication skills. (3) This study proposed that the therapists' preferred use of agreement expressions in the intervention process could be explained by the features of Naturalistic Intervention.

8.
Int J Biol Macromol ; 160: 1066-1077, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-32502610

ABSTRACT

In this paper, selenized Artemisia sphaerocephala polysaccharides (SePAS) were obtained through employing N-methyl-2-pyrrolidone hydrosulfate as catalyst, which showed a maximum Se content enhanced to 8744 µg/g. FT-IR, 1D/2D NMR, X-ray photoelectron spectroscopy (XPS) and size-exclusion chromatograph analysis exhibited that Se had been successfully introduced into PAS and existed in the form of selenate group (Se4+) with the substitution position at C-6. Furthermore, immunostimulating assays indicated that SePAS with high Se content exhibited stronger immunomodulatory activities by upregulated the phosphorylation level of ERK, JNK and p38, thus enhancing RAW264.7 cells proliferation, phagocytosis, levels of interleukin-6, nitric oxide, tumor necrosis factor and interleukin-1ß. The current outcome suggested that Se content might be a critical factor affecting the immunomodulatory effects of selenized PAS on macrophage RAW264.7.


Subject(s)
Immunologic Factors/chemical synthesis , MAP Kinase Signaling System/drug effects , Polysaccharides/chemistry , Pyrrolidinones/chemistry , Selenious Acid/chemistry , Animals , Artemisia/chemistry , Cell Proliferation , Immunologic Factors/pharmacology , Interleukin-6/metabolism , MAP Kinase Kinase 4/metabolism , Mice , Nitric Oxide/metabolism , Phagocytosis , RAW 264.7 Cells , Tumor Necrosis Factor-alpha/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism
9.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(3): 382-387, 2020 Mar 30.
Article in Chinese | MEDLINE | ID: mdl-32376582

ABSTRACT

OBJECTIVE: To analyze the correlation of annexin A2 with coronary atherosclerotic heart disease (CAD) and the severity of CAD. METHODS: We collected data from a total of 200 inpatients admitted in our department between August, 2017 and August, 2019. According to the. RESULTS: of coronary angiography, the patients were divided into CAD group (n=150) and non-CAD (n=50), and the CAD patients was further divided, according to their clinical stability, into stable angina (SAP) group and acute coronary syndrome (ACS) group. Serum levels of annexin A2, MPO and PON1 were detected in all these patients, and their correlations with CAD, disease severity, and degree of coronary artery stenosis were analyzed.ResultsThe levels of annexin A2 and MPO were significantly higher in CAD patients than in non-CAD patients (P < 0.05). Among the CAD patients, those with ACS had significantly higher levels of annexin A2 (P < 0.05) and lower levels of PON-1 (P < 0.05) than those with SAP, but annexin A2 level was not significantly correlated with coronary lesion count, Gensini score, or the co-morbidity of diabetes. CONCLUSIONS: Annexin A2 is significantly elevated in patients with CAD, especially in those with ACS, and can be used as a predictor of clinical instability.


Subject(s)
Annexin A2/blood , Coronary Artery Disease , Aryldialkylphosphatase , Biomarkers , Coronary Angiography , Female , Humans , Male , Severity of Illness Index
10.
Biochem Biophys Res Commun ; 526(4): 960-966, 2020 06 11.
Article in English | MEDLINE | ID: mdl-32303334

ABSTRACT

Intracellular calcium is related to cardiac hypertrophy. The CaV1.2 channel and Ca2+/calmodulin-dependent protein kinase II (CaMKII) and CaM regulate the intracellular calcium content. However, the differences in CaMKII and CaM in cardiac hypertrophy are still conflicting and are worthy of studying as drug targets. Therefore, in this study, we aim to investigate the roles and mechanism of CaM and CaMKII on CaV1.2 in pathological myocardial hypertrophy. The results showed that ISO stimulation caused SD rat heart and cardiomyocyte hypertrophy. In vivo, the HW/BW, LVW/BW, cross-sectional area, fibrosis ratio and ANP expression were all increased. There were no differences in CaV1.2 channel expression in the in vivo model or the in vitro model, but the ISO stimulation induced channel activity, and the [Ca2+]i increased. The protein expression levels of CaMKII and p-CaMKII were all increased in the ISO group, but the CaM expression level decreased. AIP inhibited ANP, CaMKII and p-CaMKII expression, and ISO-induced [Ca2+]i increased. AIP also reduced HDAC4, p-HDAC and MEF2C expression. However, CMZ did not play a cardiac hypertrophy reversal role in vitro. In conclusion, we considered that compared with CaM, CaMKII may be a much more important drug target in cardiac hypertrophy reversal.


Subject(s)
Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Calmodulin/metabolism , Cardiomegaly/chemically induced , Cardiomegaly/metabolism , Animals , Calcium Channels, L-Type/metabolism , Cardiomegaly/pathology , Disease Models, Animal , Histone Deacetylases/metabolism , Isoproterenol , MEF2 Transcription Factors/metabolism , Male , Phosphorylation , Rats, Sprague-Dawley
11.
Int J Biol Macromol ; 150: 189-199, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32050084

ABSTRACT

Interest in galactomannans and its derivatives as a functional health supplement is growing based on physicochemical properties. In this work, the optimized conditions of sulfated tara gum (STG) with a maximum DS of 0.66 by box-behnken design (BBD) were obtained as following: ratio of chlorosulfonic acid/pyridine 3:1, reaction time 4 h and reaction temperature 40 °C. The structure features of STG such as the degree of substitution (DS), substitution position, weight average molar mass (MW), monosaccharide components and chain conformation were investigated. Decreasing of MW, the increasing of Z-average radius of gyration (〈S2〉Z1/2) and specific volume for gyration (SVg) were obtained by SEC-MALLS. In addition, the structural properties of four sulfated galactomannans were comparatively investigated and analyzed based on our earlier reports of sulfated fenugreek gum, guar gum and locust bean gum. A conclusion was drown that higher galactose branch could enhance steric hindrance, which was inferred as one of the significant factors for the derivatization efficiency, thus affecting the DS, MW and conformational transition of sulfated galactomannans. This study will provide valuable information for further research on the comparison of bioactivities and medical application of galactomannans family.


Subject(s)
Models, Chemical , Plant Gums/chemistry , Sulfates/chemistry , Algorithms , Molecular Structure , Molecular Weight , Monosaccharides/chemistry , Plant Gums/chemical synthesis , Reproducibility of Results , Spectrum Analysis , Temperature
12.
J Pharmacol Sci ; 142(4): 131-139, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31992491

ABSTRACT

N-methyl berbamine (N-MB) is a berberine derivative. Its analogue berbamine has been reported to have remarkable antiarrhythmic and ischemic protective effects. However, the pharmacological effects of N-MB are ill-defined. In this study, molecular docking was used to evaluate the binding of N-MB to CaV1.2 Ca2+ and KV11.1 K+ channels, and the effects of N-MB on action potential and ionic currents were observed in the ventricular myocytes of rabbits, HEK293 cells stably transfected with the hCaV1.2 gene and CHO cells stably transfected with hERG (human ether-a-go-go related gene). The results showed that N-MB was able to bind to both CaV1.2 and KV11.1 channels. Following a perfusion with N-MB, the durations of action potentials (APD20, APD50 and APD90) were extended, and the outward tail current, Itail, as well as the hERG current, IhERG, were inhibited, while the amplitude of action potential (APA) was only slightly reduced. N-MB also decreased the peak amplitude of the L-type Ca2+ channel current, ICaL, as well as the CaV1.2 current, ICaV1.2; this may limit the prolongation of APD. In conclusion, N-MB is a potent and natural antiarrhythmic multitarget drug that may elicit its antiarrhythmic effect through blocking both Ca2+ and K+ channel currents.


Subject(s)
Anti-Arrhythmia Agents , Benzylisoquinolines/pharmacology , Calcium Channel Blockers , Potassium Channel Blockers , Action Potentials/drug effects , Benzylisoquinolines/chemistry
13.
Front Cell Neurosci ; 13: 415, 2019.
Article in English | MEDLINE | ID: mdl-31616252

ABSTRACT

Hyperpolarization-activated cyclic nucleotide-gated ion channels (HCN channels) are widely expressed in the central and peripheral nervous systems and organs, while their functions are not well elucidated especially in the sympathetic nerve. The present study aimed to investigate the roles of HCN channel isoforms in the differentiation of sympathetic neurons using PC12 cell as a model. PC12 cells derived from rat pheochromocytoma were cultured and induced by nerve growth factor (NGF) (25 ng/ml) to differentiate to sympathetic neuron-like cells. Sympathetic directional differentiation of PC12 cells were evaluated by expressions of growth-associated protein 43 (GAP-43) (a growth cone marker), tyrosine hydroxylase (TH) (a sympathetic neuron marker) and neurite outgrowth. Results show that the HCN channel isoforms (HCN1-4) were all expressed in PC12 cells; blocking HCN channels with ivabradine suppressed NGF-induced GAP-43 expression and neurite outgrowth; silencing the expression of HCN2 and HCN4 using silenced using small interfering RNAs (siRNA), rather than HCN1 and HCN3, restrained GAP-43 expression and neurite outgrowth, while overexpression of HCN2 and HCN4 channels with gene transfer promoted GAP-43 expression and neurite outgrowth. Patch clamp experiments show that PC12 cells exhibited resting potentials (RP) of about -65 to -70 mV, and also presented inward HCN channel currents and outward (K+) currents, but no inward voltage-gated Na+ current was induced; NGF did not significantly affect the RP but promoted the establishment of excitability as indicated by the increased ability to depolarize and repolarize in the evoked suspicious action potentials (AP). We conclude that HCN2 and HCN4 channel isoforms, but not HCN1 and HCN3, promote the differentiation of PC12 cells toward sympathetic neurons. NGF potentiates the establishment of excitability during PC12 cell differentiation.

14.
Cell Mol Life Sci ; 76(24): 5027-5039, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31190084

ABSTRACT

The embedding of small peptide ligands within large inactive pre-pro-precursor proteins encoded by orphan open reading frames (ORFs) makes them difficult to identify and study. To address this problem, we generated oligonucleotide (< 100-400 base pair) combinatorial libraries from either the epidermal growth factor (EGF) ORF that encodes the > 1200 amino acid EGF precursor protein or the orphan ECRG4 ORF, that encodes a 148 amino acid Esophageal Cancer Related Gene 4 (ECRG4), a putative cytokine precursor protein of up to eight ligands. After phage display and 3-4 rounds of biopanning for phage internalization into prostate cancer epithelial cells, sequencing identified the 53-amino acid EGF ligand encoded by the 5' region of the EGF ORF and three distinct domains within the primary sequence of ECRG4: its membrane targeting hydrophobic signal peptide, an unanticipated amino terminus domain at ECRG437-63 and a C-terminus ECRG4133-148 domain. Using HEK-blue cells transfected with the innate immunity receptor complex, we show that both ECRG437-63 and ECRG4133-148 enter cells by interaction with the TLR4 immune complex but neither stimulate NFkB. Taken together, the results help establish that phage display can be used to identify cryptic domains within ORFs of the human secretome and identify a novel TLR4-targeted internalization domain in the amino terminus of ECRG4 that may contribute to its effects on cell migration, immune cell activation and tumor suppression.


Subject(s)
Immunity, Innate/genetics , Prostatic Neoplasms/genetics , Toll-Like Receptor 4/genetics , Tumor Suppressor Proteins/genetics , Cell Line, Tumor , Cell Movement/genetics , Cell Surface Display Techniques , Genes, Tumor Suppressor , Humans , Hydrophobic and Hydrophilic Interactions , Ligands , Male , NF-kappa B/genetics , Oligonucleotides/genetics , Open Reading Frames/genetics , Prostatic Neoplasms/pathology , Protein Domains/genetics , Transfection
15.
J Mol Cell Cardiol ; 131: 20-28, 2019 06.
Article in English | MEDLINE | ID: mdl-30998981

ABSTRACT

Angiotensin II (Ang II) modulates blood pressure via Ang II type 1 receptor (AT1R) and type 2 receptor (AT2R). The activation of AT2R relaxes vascular tone through opening large-conductance Ca2+-activated potassium (BKCa) channels in vascular smooth muscle cells (SMCs). In the present study, we studied the role of the AT2R-BKCa pathway in patients with hypertension. The mesenteric arterial SMCs (MSMCs) were obtained from normotensive patients (NP) and hypertensive patients (HP). BKCa currents were recorded with patch clamp and the expressions of mRNAs and proteins of AT1R/AT2R were analyzed by RT-PCR and Western blotting, respectively. Ang II significantly increased the macroscopic BKCa currents at the whole cell level, while increased the open probability and decreased the mean close time of BKCa channels at the single channel level with AT1R blockade by valsartan in NP. However, Ang II had no effect on the BKCa currents at the same condition in HP. Furthermore, the expressions of mRNA and protein of AT2R but not AT1R were markedly decreased in the MSMCs of HP compared to that of NP. The data suggest that AT2R is well functioned in the MSMCs in NP but not in HP and deficiency in the AT2R-BKCa pathway may contribute to the development of hypertension.


Subject(s)
Large-Conductance Calcium-Activated Potassium Channels/metabolism , Mesenteric Arteries/cytology , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/metabolism , Receptor, Angiotensin, Type 2/metabolism , Angiotensin II/pharmacology , Blood Pressure/drug effects , Blood Pressure/genetics , Blotting, Western , Cells, Cultured , Female , Humans , Hypertension/metabolism , In Vitro Techniques , Large-Conductance Calcium-Activated Potassium Channels/genetics , Male , Middle Aged , Patch-Clamp Techniques , Receptor, Angiotensin, Type 2/genetics , Reverse Transcriptase Polymerase Chain Reaction
16.
Med Sci Monit ; 24: 3011-3023, 2018 May 08.
Article in English | MEDLINE | ID: mdl-29737974

ABSTRACT

BACKGROUND Increased small-conductance Ca2+-activated K+ current (SK), abnormal intracellular Ca2+ handling, and enhanced expression and activity of Ca2+/calmodulin-dependent protein kinase II (CaMKII) have been found in clinical and/or experimental models of atrial fibrillation (AF), but the cumulative effect of these phenomena and their mechanisms in AF are still unclear. This study aimed to test the hypothesis that CaMKII increases SK current in human chronic AF. MATERIAL AND METHODS Right atrial appendage tissues from patients with either sinus rhythm (SR) or AF and neonatal rat atrial myocytes were used. Patch clamp, qRT-PCR, and Western blotting techniques were used to perform the study. RESULTS Compared to SR, the apamin-sensitive SK current (IKAS) was significantly increased, but the mRNA and protein levels of SK1, SK2, and SK3 were significantly decreased. In AF, the steady-state Ca2+ response curve of [i]IKAS[/i] was shifted leftward and the [Ca2+]i level was significantly increased. CaMKII inhibitors (KN-93 or autocamtide-2-related inhibitory peptide (AIP)) reduced the IKAS in both AF and SR. The inhibitory effect of KN-93 or AIP on [i]IKAS[/i] was greater in AF than in SR. The expression levels of calmodulin, CaMKII, and autophosphorylated CaMKII at Thr287 (but not at Thr286) were significantly increased in AF. Furthermore, KN-93 inhibited the expression of (Thr287)p-CaMKII and SK2 in neonatal rat atrial myocytes. CONCLUSIONS SK current is increased via the enhanced activation of CaMKII in patients with AF. This finding may explain the difference between SK current and channels expression in AF, and thus may provide a therapeutic target for AF.


Subject(s)
Atrial Fibrillation/metabolism , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Small-Conductance Calcium-Activated Potassium Channels/metabolism , Animals , Atrial Fibrillation/genetics , Atrial Fibrillation/pathology , Benzylamines/pharmacology , Calcium/metabolism , Cell Membrane Permeability/drug effects , Chronic Disease , Coronary Sinus/drug effects , Coronary Sinus/pathology , Cytosol/metabolism , Down-Regulation , Female , Heart Atria/drug effects , Heart Atria/metabolism , Heart Atria/pathology , Humans , Ion Channel Gating/drug effects , Male , Middle Aged , Patch-Clamp Techniques , Peptides/pharmacology , Phosphorylation/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Sprague-Dawley , Small-Conductance Calcium-Activated Potassium Channels/genetics , Sulfonamides/pharmacology , Up-Regulation/drug effects
17.
Front Pharmacol ; 9: 62, 2018.
Article in English | MEDLINE | ID: mdl-29456510

ABSTRACT

Background: We previously have proved that sodium tanshinone II-A sulfonate (DS-201), a derivative of traditional Chinese medicinal herb Danshen (Salvia miltiorrhiza), is an opener and vasodilator of BKCa channel in the vascular smooth muscle cells (VSMCs). Vascular tension is closely associated with Ca2+ dynamics and activation of BKCa channel may not be the sole mechanism for the relaxation of the vascular tension by DS-201. Therefore, we hypothesized that the vasorelaxing effect of DS-20 may be also related to Ca2+ channel and cytoplasmic Ca2+ level in the VSMCs. Methods: Arterial tension was measured by Danish Myo Technology (DMT) myograph system in the mesentery vessels of rats, intracellular Ca2+ level by fluorescence imaging system in the VSMCs of rats, and L-type Ca2+ current by patch clamp technique in Ca2+ channels transfected human embryonic kidney 293 (HEK-293) cells. Results: DS-201 relaxed the endothelium-denuded artery rings pre-constricted with PE or high K+ and the vasorelaxation was reversible. Blockade of K+ channel did not totally block the effect of DS-201 on vasorelaxation. DS-201 suppressed [Ca2+]i transient induced by high K+ in a concentration-dependent manner in the VSMCs, including the amplitude of Ca2+ transient, the time for Ca2+ transient reaching to the [Ca2+]i peak and the time to remove Ca2+ from the cytoplasm. DS-201 inhibited L-type Ca2+ channel with an EC50 of 59.5 µM and at about 40% efficacy of inhibition. However, DS-201did not significantly affect the kinetics of Ca2+ channel. The effect of DS-201 on L-type Ca2+ channel was rate-independent. Conclusion: The effect of DS-201 on vasorelaxation was not only via activating BKCa channel, but also blocking Ca2+ channel and inhibiting Ca2+ influx in the VSMCs of rats. The results favor the use of DS-201 and Danshen in the treatment of cardiovascular diseases clinically.

19.
Gene ; 642: 26-31, 2018 Feb 05.
Article in English | MEDLINE | ID: mdl-29126922

ABSTRACT

Epidemiogical evidence has shown that the incidence of atrial fibrillation in tumor patients is higher than non-tumor patients and general population. The potential risk factors predisposing tumor patients to atrial fibrillation include advanced age, comorbidities, direct anatomic local occupying effect of tumors in the heart or adjacent organs, paraneoplastic manifestations of some tumors, tumor-induced dys-regulation of metabolism, radio-, bio- and chemo-therapeutics, disturbance of autonomous nerve system because of physical pain and psychological sufferings, chronic inflammation typical of most tumors, and surgical interventions among others. However, whether tumor suppressor genes commonly mutated or dys-regulated in tumor play any roles in the pathogenesis of atrial fibrillation remain largely unexplored. Tumor suppressor genes or genes possessing tumor suppressing function have been reported to be constitutively expressed in quiescent heart, and mutations, small nucleotide polymorphisms, or disturbed expression of tumor suppressor genes has been implicated in the pathogenesis of atrial fibrillation. Here, we provide a state-of-the-art overview of the unrecognized roles of tumor suppressor genes in the pathogenesis of atrial fibrillation, focusing mainly on the two well-characterized tumor suppressor genes, zinc finger homeobox protein-3 and esophageal cancer related gene-4.


Subject(s)
Atrial Fibrillation/genetics , Homeodomain Proteins/genetics , Neoplasm Proteins/genetics , Neoplasms/complications , Atrial Fibrillation/epidemiology , Atrial Fibrillation/etiology , Female , Gene Expression Regulation , Genetic Predisposition to Disease , Homeodomain Proteins/metabolism , Humans , Male , Mutation , Myocardium/metabolism , Myocardium/pathology , Neoplasm Proteins/metabolism , Neoplasms/genetics , Polymorphism, Genetic , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism
20.
Purinergic Signal ; 13(4): 591-600, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28929376

ABSTRACT

Uridine adenosine tetraphosphate (Up4A) exerts potent relaxation in porcine coronary arteries that is reduced following myocardial infarction, suggesting a crucial role for Up4A in the regulation of coronary flow (CF) in cardiovascular disorders. We evaluated the vasoactive effects of Up4A on CF in atherosclerosis using ApoE knockout (KO) mice ex vivo and in vivo. Functional studies were conducted in isolated mouse hearts using the Langendorff technique. Immunofluorescence was performed to assess purinergic P2X1 receptor (P2X1R) expression in isolated mouse coronary arteries. In vivo effects of Up4A on coronary blood flow (CBF) were assessed using ultrasound. Infusion of Up4A (10-9-10-5 M) into isolated mouse hearts resulted in a concentration-dependent reduction in CF in WT and ApoE KO mice to a similar extent; this effect was exacerbated in ApoE KO mice fed a high-fat diet (HFD). The P2X1R antagonist MRS2159 restored Up4A-mediated decreases in CF more so in ApoE KO + HFD than ApoE KO mice. The smooth muscle to endothelial cell ratio of coronary P2X1R expression was greater in ApoE KO + HFD than ApoE KO or WT mice, suggesting a net vasoconstrictor potential of P2X1R in ApoE KO + HFD mice. In contrast, Up4A (1.6 mg/kg) increased CBF to a similar extent among the three groups. In conclusion, Up4A decreases CF more in ApoE KO + HFD mice, likely through a net upregulation of vasoconstrictor P2X1R. In contrast, Up4A increases CBF in vivo regardless of the atherosclerotic model.


Subject(s)
Atherosclerosis/metabolism , Coronary Circulation/drug effects , Dinucleoside Phosphates/pharmacology , Receptors, Purinergic P2X1/metabolism , Animals , Isolated Heart Preparation , Mice , Mice, Inbred C57BL , Mice, Knockout, ApoE , Purinergic P2X Receptor Antagonists/pharmacology
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