ABSTRACT
Unlike adult mammalian heart, zebrafish heart has a remarkable capacity to regenerate after injury. Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium and this activation is mediated by hemodynamic alteration after injury, however, the molecular mechanism has not been fully explored. In this study we demonstrated that blood flow change could be perceived and transmitted in a primary cilia dependent manner to control the hemodynamic responsive klf2 gene expression and subsequent activation of Notch signaling in the endocardium. First we showed that both homologues of human gene KLF2 in zebrafish, klf2a and klf2b, could respond to hemodynamic alteration and both were required for Notch signaling activation and heart regeneration. Further experiments indicated that the upregulation of klf2 gene expression was mediated by endocardial primary cilia. Overall, our findings reveal a novel aspect of mechanical shear stress signal in activating Notch pathway and regulating cardiac regeneration.
ABSTRACT
Unlike adult mammalian heart, zebrafish heart has a remarkable capacity to regenerate after injury. Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium and this activation is mediated by hemodynamic alteration after injury, however, the molecular mechanism has not been fully explored. In this study we demonstrated that blood flow change could be perceived and transmitted in a primary cilia dependent manner to control the hemodynamic responsive klf2 gene expression and subsequent activation of Notch signaling in the endocardium. First we showed that both homologues of human gene KLF2 in zebrafish, klf2a and klf2b, could respond to hemodynamic alteration and both were required for Notch signaling activation and heart regeneration. Further experiments indicated that the upregulation of klf2 gene expression was mediated by endocardial primary cilia. Overall, our findings reveal a novel aspect of mechanical shear stress signal in activating Notch pathway and regulating cardiac regeneration.
ABSTRACT
Objective To observe the effect of intermittent and continuous blue light therapy for pathological neonatal jaundice,and to evaluate the prognosis of newborns.Methods 214 patients with pathologic neonatal jaundice who treated with blue light irradiation were slected,they were randomly divided into two groups according to the admission number combined with single and double numbers,107 patients in each group.Group A received continuous blue light irradiation treatment.Group B received intermittent blue light irradiation.The clinical efficacy and prognosis of children,blue light exposure time,serum total bilirubin (TBiL) recovery time,the hospitalization time and the adverse reactions during the treatment were observed.The levels of serum TBiLwere measured before and after light exposure 3,5 days.Results The total effective rate of group B was 97.18％ (104/107),which was higher than that of group A [90.65 ％ (97/107)],the difference was statistically significant (x2 =10.30,P ＜ 0.05).The time of blue light irradiation and hospital stay time of group B were (71.59 ± 7.05) d and (11.51 ± 1.23) d,respectively,which were significantly shorter than those of group A [(79.54 ± 6.82) d and (13.64 ± 1.18) d],the differences were statistically significant (u =11.42,9.87,all P ＜ 0.05).The level of TBiL of group B was (96.28 ± 10.25) μmol/L,which was significantly lower than (104.52 ± 10.31) μmol/L of group A (u =8.94,P ＜ 0.05).The incidence rate of adverse reactions in group B was 2.55％ (4/157),which was lower than that in group A [7.01％ (11/157)],the difference was statistically significant (x2 =9.66,P ＜ 0.05).The prognosis of neonatal in the two groups was good.Conclusion The intermittent and continuous blue light in the treatment of pathological neonatal jaundice has good clinical effect and the neonatal prognosis is good.The clinical efficacy of intermittent blue light irradiation is better,which can significantly shorten the treatment time and has higher safety.