Aim To investigate the mechanism of RhoA/ROCK signaling pathway in abnormal aortic contractility in type 2 diabetes (T2DM) mice. Methods The experiment was divided into two groups, the control group (db/m mice) and the model group (db/db mice). Changes of the response to different methods were measured in aorta rings using a Multi Myograph System. At the same time, the protein expression changes of aortic smooth muscle contraction signaling pathway in mice were determined by Western method. Results Compared with the control group, the blood glucose and body weight levels of the mice in the T2DM group significantly increased, and the cardiac function was abnormal (P <0. 01). The contractile response of the aorta of the diabetic mice induced by the contractile agents Phe, 5-HT and CaCl

To investigate the regulation of N6- methyladenosine ( m6A ) modification on L-type calcium channels in atrial myocytes under high hydrostatic pressure, mediated by methyltransferase-like protein 3 ( METTL3 ). Methods C57BL/6J mice were randomly assigned to the control group and the hypertension group ( treated with continuous administration of angiotensin for four weeks ). Masson staining was used to observe the fibrosis of mouse atrial tissue, while dot blot assay and Western blot were used to detect the levels of m6A, METTL3, and Cavi1 2 in the atrial tissue. A high hydrostatic pressure model was constructed using the HL-1 cell line cultured in vitro, and METTL3 was intervened to observe changes in m6A expression levels, METTL3 and Cavi1 2 levels in cells,and action potential duration ( APD ) and L-type calcium current ( I

Recent population studies have significantly advanced our understanding of how age shapes the gut microbiota.However,the actual role of age could be inevitably confounded due to the complex and variable environmental factors in human populations.A well-controlled envi-ronment is thus necessary to reduce undesirable confounding effects,and recapitulate age-dependent changes in the gut microbiota of healthy primates.Herein we performed 16S rRNA gene sequenc-ing,characterized the age-associated gut microbial profiles from infant to elderly crab-eating maca-ques reared in captivity,and systemically revealed the lifelong dynamic changes of the primate gut microbiota.While the most significant age-associated taxa were mainly found as commensals such as Faecalibacterium,the abundance of a group of suspicious pathogens such as Helicobacter was exclusively increased in infants,underlining their potential role in host development.Importantly,topology analysis indicated that the network connectivity of gut microbiota was even more age-dependent than taxonomic diversity,and its tremendous decline with age could probably be linked to healthy aging.Moreover,we identified key driver microbes responsible for such age-dependent network changes,which were further linked to altered metabolic functions of lipids,carbohydrates,and amino acids,as well as phenotypes in the microbial community.The current study thus demon-strates the lifelong age-dependent changes and their driver microbes in the primate gut microbiota,and provides new insights into their roles in the development and healthy aging of their hosts.

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.

Aim To investigate the role of calcium-independent phospholipase A2(iPLA2)in calcium regu-lation of intrarenal artery smooth muscle contraction.Methods The method of measuring the tension of isolated arterioles was used to explore the effect of bromoenol lactone(BEL), a specific inhibitor of iPLA2, on the tension of the intrarenal arteries in mice induced by different calcium channels, and the laser confocal calcium measurement technology was used to investigate the effect of BEL on the intracellular calcium influx mediated by arachidonic acid-mediated calcium channels.Results The intrarenal artery concentration dependent contractile response induced by the vasoconstrictors phenylephrine and 5-hydroxy tryptamine was inhibited by BEL(P<0.01).The contraction curve induced by CaCl2 was also inhibited by BEL(P<0.05).In the calcium-free K-H solution incubated with nifedipine, the intrarenal artery vasoconstriction caused by the release of sarcoplasmic reticulum calcium and the calcium influx of the SOC channel induced by CaCl2 was inhibited by BEL(P<0.05).BEL significantly inhibited the external calcium influx mediated by the ARC channel of human aortic smooth muscle cell lines incubated with nifedipine(P<0.01).Conclusions iPLA2 mediates the contractile response of intrarenal arteries by regulating the functions of L-type calcium channels, sarcoplasmic reticulum calcium release, SOC channels and ARC channels.

Aim To explore type 1 diabetes mice and the advance glycation end products (AGE) involved in electrical remodeling of atrial myocytes. Methods The diabetic mouse model was induced by intraperitoneal injection of STZ; action potential duration, and the current density of I

Aim To explore the role of cotranscriptional activator p300 in regulating the electrical remodeling of atrial myocytes in aging mouse, which resulted in atrial fibrillation. Methods The left atrial appendage tissues of 5 , 13 and 18monthold C57BL/6 mice were collected respectively. Western blot was used to detect the protein expression levels of p300, L type calcium channel (Cavl. 2) and aging related protein p53/p21. Acute enzymatic hydrolysis was used to isolate single atrial myocytes, and the wholecell patchclamp technique was used to detect the Ltype calcium current (I

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.

Aim To investigate the role of Ca

Objective: To investigate whether inflammatory factor tumor necrosis factor-α (TNF-α) is involved in the electrical remodeling of cardiomyocytes by regulating ultra-rapid delayed rectifier K(+) current (I(kur)) and the role of Src kinase. Methods: H9c2 cells, embryonic cardiomyocytes of rat, were cultured in Dulbecco's modified Eagle's medium (DMEM) and atrium-derived HL-1 cells were cultured in Claycomb medium. Both H9c2 and HL-1 cells were cultured at 37 ℃ with 5% CO(2). Cells cultured in normal conditions without additional treatment served as control group. Experimental groups were treated with different concentration of TNF-α (25 or 50 or 100 ng/ml) for 24 hours. To study whether Src specific inhibitor PP1 could abrogate the effect of TNF-α, cells were pre-treated with 10 μmol/L PP1 for 1 hour, followed by TNF-α (100 ng/ml) for 24 hours. Western blot and the whole cell patch clamp technique were used to detect the protein expression of Kv1.5 and Src and I(kur) in each group. Results: (1) In H9c2 cells, high concentration of TNF-α treatment (100 ng/ml) significantly reduced the Kv1.5 protein expression compared with control group and TNF-α 25 ng/ml group (both P<0.05). Compared with control group, the expression of p-Src protein was higher in 25 ng/ml, 50 ng/ml, 100 ng/ml TNF-α group (all P<0.05), but there was no statistical difference in the expression of Src protein among groups (P>0.05). In addition, the current density of I(kur) was decreased in 50 ng/ml, 100 ng/ml TNF-α group (both P<0.05). Furthermore, the expression of Kv1.5 protein and the current density of I(kur) were increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (both P<0.05). There was no statistical difference in the expression of Kv1.5 protein and the current density of I(kur) between the control group and PP1+TNF-α group (both P>0.05). (2) In atrium-derived HL-1 cells, the expression of Kv1.5 protein was reduced in 100 ng/ml TNF-α group compared with control group and TNF-α 25 ng/ml group (both P<0.01). In addition, the expression of p-Src protein was increased in TNF-α 100 ng/ml group compared with control group (P<0.05), but there was no statistical difference in the protein expression of Src among groups (P>0.05). The expression of Kv1.5 protein was increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (P<0.05). Conclusion: TNF-α is involved in the pathogenesis of atrial fibrillation, probably via decreasing I(kur) current density in atrium-derived myocytes through the activation of Src kinase.
Animals ; Down-Regulation ; Heart Atria ; Myocytes, Cardiac ; Rats ; Tumor Necrosis Factor-alpha ; src-Family Kinases