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Aim To investigate the role of mechano- sensitive ion channel Piezol in regulating electrical re-modeling of atrial myocytes induced by hypertension and to further explore the potential mechanisms.Methods Spontaneously hypertensive rats ( SHR ) aged 30 - 32 weeks treated with or without valsartan (30 mg • kg 1 • d 1 ) were used.Wistar rats were used as control.Western blot was used to detect the protein expression of Piezol , Src and Cavl.2 in atrial appendages of rats and in atrial myocytes ( HL-1 cells) exposed to different levels of high hydrostatic pressure (20 and 40 mmHg) , Piezol inhibitor (GsmTx4) and agonist ( Yodal ) in vitro.Whole-cell patch clamp technique was employed to detect L-tvpe calcium current (ICa, ) and action potential duration ( APD) of atrial myocytes.Results Compared with Wistar rats in control group, the protein expressions of Piezol and Src significantly increased and the expression of Cavl.2 decreased in SHR group (P < 0.05 ), while the a- bove changes could he reversed in SHR treated with valsartan( P < 0.05 ) .Meanwhile, higher hydrostatic pressure (40 mniHg) could increase the expressions of Piezol and Src in HL-1 cells( P <0.05) and decrease the protein expression of Cavl.2 (P <0.05 ) , accompanied by a shortened APD and a decreased ICa,.GsmTx4 could significantly reverse the above changes.In addition, Piezol agonist Yodal could simulate electrical remodeling and related signal molecule changes in atrial myocytes induced by the high hydrostatic pressure.Conclusions Mechanosensitive ion channel Piezol participates in electrical remodeling induced by hypertension via activating Src kinase signaling pathway and then leading to the decrease of ICa ,.
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Aim To investigate the mechanism of Pi- ezol in the phenotypic changes of rat coronary arterial smooth muscle cells ( CASMCs) induced by high hydrostatic pressure.Methods CASMCs were isolated from Wistar rats and stimulated for 24 h at 0, 120 and 180 mmHg, respectively.The expressions of Piezol , contractile phenotvpe-related proteins including Cavl.2 ,SM-MHC ,cx-SMA and synthetic phenotvpe-re- lated proteins including OPN , MMP-2, Coll al were detected by Western blot.The effect of calcium influx mediated by Piezol was detected by Laser confocal mi- j j croscopy.CASMCs were treated with Piezol agonist Yodal , inhibitor GsMTx4 and Piezol-siHNA , respectively and the expressions of contractile phenotvpe and synthetic phenotvpe-related proteins were detected by Western blot.Results Compared with control ( 0 mmHg) , the expressions of Piezol , OPN, MMP-2 and Collal increased, but the expressions of Cavl.2,SM- MHC and cx-SMA decreased in 120 mmHg as well as 180 mmHg group.After stimulated by 180 mmHg high pressure, Piezol-mediated calcium influx was stronger than that in 0 mmHg group, hut decreased after Piezol knockdown.Treated with Yodal at 0 mmHg, the expression of contractile phenotvpe-related protein decreased while the expression of synthetic phenotvpe-re- lated protein increased compared with DMSO group..\Jfter using GsMTx4 to inhibit or siRNA to knockdown Piezol at 180 mmHg,the expression of contractile phe- notvpe-related protein increased and the expression of synthetic phenotype-related protein decreased compared with the control group.Conclusion Piezol promotes the transition from contractile phenotvpe to syn-thetic phenotvpe of CASMCs induced by high hydrostatic pressure.
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Aim To investigate the role and potential mechanism of transcriptional co-activator p300 in atrial fibrosis caused by high hydrostatic pressure. Methods The left atrial appendage tissues of humans in three groups of sinus rhythm, atrial fibrillation (AF), hypertension and AF were collected. The expressions of p300 protein and TGF-β/Smad3 signaling pathway and fibrotic factors as type I/III collagen Alphal chain (Col-lAl/Col-3Al), matrix metalloproteinase 2/9 (MMP-2/9) were tested by Western blot. Mouse atrial appendage fibroblasts were cultured under hydrostatic pressures of 0, 20 and 40 mmHg. The fibroblasts cultured under 40 mmHg pressure were treated with curcumin and p300 interference RNA. Western blot was used to test changes in the expression of p300 and the above fibrosis indicators. CCK-8 method was used to test changes of cell proliferation. Results The expressions of p300 and TGF-β/Smad3 signaling pathway proteins and fibrotic factors in AF group and hypertension combined with AF group were significantly higher than those in sinus rhythm group (P < 0. 05). 40 mmHg high hydrostatic pressure stimulation in vitro could increase the expression of p300 and fibrotic factors in fibroblasts (P < 0. 0 5) and enhance the proliferation ability (P < 0. 05). Both curcumin and p300 interfering RNA could reverse the increased expression of p300 and fibrotic factors (P < 0. 05) and decrease cell proliferation (P < 0. 05) induced by hydrostatic pressure. Conclusions High hydrostatic pressure can induce atrial fibrosis, which involves the participation of p300 in this process by regulating the TGF-β/Smad3 signaling pathway.
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ABSTRACT: The effect of high hydrostatic pressure (HHP) application on whey protein concentrate was evaluated both before (pre-treatment - PT) and during (hydrolysis assisted - HA) hydrolysis processes. A factorial design 22 with 3 central points was used with pressure (100, 250, 400 MPa) and time (5, 20 and 35 minutes) as independent variables. The hydrolysis was evaluated and monitored by soluble protein, aromatic amino acid contents and RP-HPLC. ABTS and ORAC tests were used to evaluate the in vitro antioxidant capacity. The reduction of soluble protein content was approximately 20% for conventional hydrolysis and for all PT treatments up to 4 h of reaction, while HHP assisted hydrolysis at 100 MPa showed a 35% protein reduction after 35 minutes of reaction. In addition, pressurization favored peptic hydrolysis of β-lactoglobulin by up to 98% and also improved the in vitro antioxidant capacity of the hydrolysates, which increased from 34.25 to 60.89 μmoles TE g-1 of protein in the best treatment. The results suggest that the use of HHP assisted hydrolysis favored the peptic hydrolysis, with a reduction in hydrolysis time and increased antioxidant activity.
RESUMO: Neste estudo, o efeito da aplicação de alta pressão hidrostática (HHP) sobre o concentrado proteico de soro de leite foi avaliado antes (pré-tratamento - PT) e durante os processos de hidrólise (assistida por hidrólise - HA). Utilizou-se o delineamento fatorial 22 com três pontos centrais, onde as variáveis independentes foram pressão (100, 250, 400 MPa) e tempo (5, 20 e 35 minutos). A hidrólise foi avaliada pelo conteúdo de proteínas solúveis e aminoácidos aromáticos, além do perfil peptídico por RP-HPLC. As análises de ABTS e ORAC foram utilizadas para avaliar a capacidade antioxidante in vitro. A redução do teor de proteína solúvel foi de aproximadamente 20% para a hidrólise convencional e para todos os pontos de PT até 4h de reação, enquanto a hidrólise assistida por HHP a 100 MPa mostrou uma redução de 35% de proteína em 35 minutos de reação. Além disso, a pressurização favoreceu a hidrólise péptica da β-lactoglobulina em até 98% e também melhorou a capacidade antioxidante in vitro dos hidrolisados, que aumentaram de 34,25 para 60,89 μmoles de TE g-1 de proteína no melhor tratamento. Os resultados sugerem que o uso da hidrólise assistida por HHP favoreceu a hidrólise péptica, com redução no tempo de hidrólise e aumento da atividade antioxidante.
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Background : Cardiovascular surgery involves the use of several artificial materials as graft vessels. Although artificial blood vessels of medium and large diameters currently present a satisfactory patency and durability, those of small diameter remain inferior to one's own vessels to prevent issues such as early thrombosis and vascular stenosis. The present study aimed to investigate the functionality of decellularized tissues that hold structures and growth factors derived from a living body. Methods : Mini pigs were used for the study. The bovine-derived decellularized blood vessels were transplanted into the pigs' carotid artery, and no anticoagulant or antiplatelet drugs were used after the surgery. The blood vessels were dissected and evaluated for patency and tissue staining. Result : The patency of the blood vessels was confirmed in all cases ; however, a thrombus was confirmed in one transplanted vessel. Pathological findings showed maintenance of the blood vessel structure, presenting no issues with collagen or elastin. Conclusion : This study demonstrated that biologically derived decellularized blood vessels are highly functional and present an intact luminal basement membrane, even without antiplatelet therapy. This study suggested that decellularized blood vessels can potentially help in the development of medical devices with higher functionality than that of the existing materials.
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Objective: To explore the application of high hydrostatic pressure in the development of melanoma vaccine.Methods:The high hydrostatic pressure,liquid nitrogen freezing and thawing were used to break the murine B16 melanoma cells and then the cell suspension was mixed with Freund's adjuvant to prepare vaccine for immunizing the mice.Results:After immu-nization,the murine B16 melanoma cells were injected intravenously and subcutaneously.The immune results of the vaccines were evaluated,by comparing survival time of the mice, subcutaneous tumor volume, DTH experiments and the fluorescence imaging of tumors.Conclusion:Compared with the method of liquid nitrogen freeze-thaw broken,high hydrostatic pressure crushing cells has more advantages in the development of tumor vaccine.
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High hydrostatic pressure (HHP) has been investigated and industrially applied to extend shelf life of meat-based products. Traditional ham packaged under microaerophilic conditions may sometimes present high lactic acid bacteria population during refrigerated storage, which limits shelf life due to development of unpleasant odor and greenish and sticky appearance. This study aimed at evaluating the shelf life of turkey ham pressurized at 400 MPa for 15 min and stored at 4, 8 and 12 ºC, in comparison to the non pressurized product. The lactic acid bacteria population up to 10(7) CFU/g of product was set as the criteria to determine the limiting shelf life According to such parameter the pressurized sample achieved a commercial viability within 75 days when stored at 4 ºC while the control lasted only 45 days. Predictive microbiology using Gompertz and Baranyi and Roberts models fitted well both for the pressurized and control samples. The results indicated that the high hydrostatic pressure treatment greatly increased the turkey ham commercial viability in comparison to the usual length, by slowing down the growth of microorganisms in the product.
Subject(s)
Humans , Lactic Acid/analysis , Lactic Acid/isolation & purification , Food Preservation/methods , Food Analysis , Food Microbiology , Foods Modified by Air Incorporation , Meat Products/analysis , Food Samples , Hydrostatic Pressure , Methods , TurkeysABSTRACT
Objective To evaluate the influences of high hydrostatic pressure (HHP) on the virulence and antigenicity of Coxsackie virus B3 (CB3 V) , to explore a new physiological method to develop an active vaccine against Coxsackie virus. Methods The phagocytosis of the macrophages in mice to the CB3 V and the TCID50 of the CB3V before and after treated by HHP were examined. Results TCID50 increased from 10-5 to 10-4 when treated by 680 MPa; viruses were inactivated at 700 MPa. Viruses were also inactivated by the pressure less than 700 MPa, but needed prolonged time. The phagocytic function, antibody and T lymphocyte transformation rate in experimental mice (heated, attenuated, and inactive viruses) exhibited a significant difference compared with control mice (P
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Actinobacillus succinogenes A3 was mutagenized by ultra high hydrostatic pressure for improving the production ability of succinic acid.The effects of pressure,rate of pressure changes and growth periods on the lethality rate of the strain were investigated.The strain in stationary phase was mutagenized at 200 MPa with the pressure changes at the rate of 50 MPa/min.As a result,a mutation strain Actinobacillus succinogenes B19 was obtained,and the concentration of succinic acid could reach 32.2 g/L,which was 17.9%higher than that of the original strain,and in the meanwhile the concentration of acetic acid was decreased by 11.5%.After six generation,the mutant also has good stability of descendiblity for succinic acid production.
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The combination effect of high hydrostatic pressure and moderate heat on the inactivation kinetics of Bacillus coagulans spore in phosphate buffer and UHT(Ultra High Temperature)whole milk was investigated.The pressure come-up time and corresponding log-reduction of spore inactivation were considered during pressure-thermal treatment.Bacillus coagulans spore had a much higher resistance to pressure in UHT whole milk than in phosphate buffer.Survival data were modeled using the linear,Weibull and log-logistic models to obtain relevant kinetic parameters.The tailing phenomenon occurred in all survival curves,indicating the linear model was not adequate for describing these curves.The log-logistic model produced best fits to survival curves,following by Weibull model.