Increased use of pyrethroids and the exposure to pyrethroids for pregnant women and children have raised the concerns over the potential effect of pyrethroids on developmental cardiotoxicity and other abnormalities.Th...Increased use of pyrethroids and the exposure to pyrethroids for pregnant women and children have raised the concerns over the potential effect of pyrethroids on developmental cardiotoxicity and other abnormalities.The purpose of this study was to investigate whether long tenn peri natal deltamethrin exposure altered embryonic cardiac electrophysiology in mice.Pregnant mice were administered with 0 or 3 mg/kg of deltamethrin by gavage daily from gestational day(gd)10.5 to gd 17.5.Whole cell patch-clamp technique was used in electrophysiological study,and real time RT-PCR was applied to analyze the molecular changes for the electrophysiological properties.Deltamethrin exposure resulted in increased mortality of pregnant mice and decreased viability of embryos.Moreover,deltamethrin slowed the maximum depolarization velocity(Vmax),prolonged the action potential duration(APD)and depolarized the maximuin diastolic potential(MDP)of embryonic cardiomyocytes.Additionally,perinatal deltamethrin exposure decreased the mRNA expression of Na^+channel regulatory subunit Navpl,inward rectifier K^+channel subunit Kir2.1,and delayed rectifier K^+channel subunit MERG while the L-type Ca^2+channel subunit,Cavl.2 expression was increased.On the contraiy,deltamethrin administration did not significantly alter the regulation ofβ-adrenergic or muscarinic receptor on embryonic cardiomyocytes.In conclusion,deltamethrin exposure at perinatal stage significantly alters mRNA expression of embryonic cardiac ion channels and therefore influences embryonic cardiac electrophysiological properties.This highlights the need to understand the persistent effects of pyrethroid exposure on cardiac function during embryonic development due to potential for cardiac arrhythmogenicity.展开更多
Thymosin β4（Tβ4） is a key factor in cardiac development, growth, disease, epicardial integrity, blood vessel formation and has cardio-protective properties. However, its role in murine embryonic stem cells（m ESCs...Thymosin β4（Tβ4） is a key factor in cardiac development, growth, disease, epicardial integrity, blood vessel formation and has cardio-protective properties. However, its role in murine embryonic stem cells（m ESCs） proliferation and cardiovascular differentiation remains unclear. Thus we aimed to elucidate the influence of Tβ4 on m ESCs. Target genes during m ESCs proliferation and differentiation were detected by real-time PCR or Western blotting, and patch clamp was applied to characterize the m ESCs-derived cardiomyocytes. It was found that Tβ4 decreased m ESCs proliferation in a partial dose-dependent manner and the expression of cell cycle regulatory genes c-myc, c-fos and c-jun. However, m ESCs self-renewal markers Oct4 and Nanog were elevated, indicating the maintenance of self-renewal ability in these m ESCs. Phosphorylation of STAT3 and Akt was inhibited by Tβ4 while the expression of RAS and phosphorylation of ERK were enhanced. No significant difference was found in BMP2/BMP4 or their downstream protein smad. Wnt3 and Wnt11 were remarkably decreased by Tβ4 with upregulation of Tcf3 and constant ？-catenin. Under m ESCs differentiation, Tβ4 treatment did not change the expression of cardiovascular cell markers α-MHC, PECAM, and α-SMA. Neither the electrophysiological properties of m ESCs-derived cardiomyocytes nor the hormonal regulation by Iso/Cch was affected by Tβ4. In conclusion, Tβ4 suppressed m ESCs proliferation by affecting the activity of STAT3, Akt, ERK and Wnt pathways. However, Tβ4 did not influence the in vitro cardiovascular differentiation.展开更多
基金a grant from the National Natural Science Foundation of China(No.81100818).
文摘Increased use of pyrethroids and the exposure to pyrethroids for pregnant women and children have raised the concerns over the potential effect of pyrethroids on developmental cardiotoxicity and other abnormalities.The purpose of this study was to investigate whether long tenn peri natal deltamethrin exposure altered embryonic cardiac electrophysiology in mice.Pregnant mice were administered with 0 or 3 mg/kg of deltamethrin by gavage daily from gestational day(gd)10.5 to gd 17.5.Whole cell patch-clamp technique was used in electrophysiological study,and real time RT-PCR was applied to analyze the molecular changes for the electrophysiological properties.Deltamethrin exposure resulted in increased mortality of pregnant mice and decreased viability of embryos.Moreover,deltamethrin slowed the maximum depolarization velocity(Vmax),prolonged the action potential duration(APD)and depolarized the maximuin diastolic potential(MDP)of embryonic cardiomyocytes.Additionally,perinatal deltamethrin exposure decreased the mRNA expression of Na^+channel regulatory subunit Navpl,inward rectifier K^+channel subunit Kir2.1,and delayed rectifier K^+channel subunit MERG while the L-type Ca^2+channel subunit,Cavl.2 expression was increased.On the contraiy,deltamethrin administration did not significantly alter the regulation ofβ-adrenergic or muscarinic receptor on embryonic cardiomyocytes.In conclusion,deltamethrin exposure at perinatal stage significantly alters mRNA expression of embryonic cardiac ion channels and therefore influences embryonic cardiac electrophysiological properties.This highlights the need to understand the persistent effects of pyrethroid exposure on cardiac function during embryonic development due to potential for cardiac arrhythmogenicity.
基金supposed by grants from National Natural Science Foundation of China(No.81100818,No.31100828 and No.81070342)the Fundamental Research Funds for the Central Universities(HUST:No.2012TS036)
文摘Thymosin β4（Tβ4） is a key factor in cardiac development, growth, disease, epicardial integrity, blood vessel formation and has cardio-protective properties. However, its role in murine embryonic stem cells（m ESCs） proliferation and cardiovascular differentiation remains unclear. Thus we aimed to elucidate the influence of Tβ4 on m ESCs. Target genes during m ESCs proliferation and differentiation were detected by real-time PCR or Western blotting, and patch clamp was applied to characterize the m ESCs-derived cardiomyocytes. It was found that Tβ4 decreased m ESCs proliferation in a partial dose-dependent manner and the expression of cell cycle regulatory genes c-myc, c-fos and c-jun. However, m ESCs self-renewal markers Oct4 and Nanog were elevated, indicating the maintenance of self-renewal ability in these m ESCs. Phosphorylation of STAT3 and Akt was inhibited by Tβ4 while the expression of RAS and phosphorylation of ERK were enhanced. No significant difference was found in BMP2/BMP4 or their downstream protein smad. Wnt3 and Wnt11 were remarkably decreased by Tβ4 with upregulation of Tcf3 and constant ？-catenin. Under m ESCs differentiation, Tβ4 treatment did not change the expression of cardiovascular cell markers α-MHC, PECAM, and α-SMA. Neither the electrophysiological properties of m ESCs-derived cardiomyocytes nor the hormonal regulation by Iso/Cch was affected by Tβ4. In conclusion, Tβ4 suppressed m ESCs proliferation by affecting the activity of STAT3, Akt, ERK and Wnt pathways. However, Tβ4 did not influence the in vitro cardiovascular differentiation.
