TAZ and myostatin involved in muscle atrophy of congenital neurogenic clubfoot

BACKGROUND Muscular atrophy is the basic defect of neurogenic clubfoot.Muscle atrophy of clubfoot needs more scientific and reasonable imaging measurement parameters to evaluate.The Hippo pathway and myostatin pathway may be directly correlated in myogenesis.In this study,we will use congenital neurogenic clubfoot muscle atrophy model to verify in vivo.Further,the antagonistic mechanism of TAZ on myostatin was studied in the C2C12 cell differentiation model.AIM To identify muscle atrophy in fetal neurogenic clubfoot by ultrasound imaging and detect the expression of TAZ and myostatin in gastrocnemius muscle.To elucidate the possible mechanisms by which TAZ antagonizes myostatin-induced atrophy in an in vitro cell model.METHODS Muscle atrophy in eight cases of fetal unilateral clubfoot with nervous system abnormalities was identified by 2D and 3D ultrasound.Western blotting and immunostaining were performed to detect expression of myostatin and TAZ.TAZ overexpression in C2C12 myotubes and the expression of associated proteins were analyzed by western blotting.RESULTS The maximum cross-sectional area of the fetal clubfoot on the varus side was reduced compared to the contralateral side.Myostatin was elevated in the atrophied gastrocnemius muscle,while TAZ expression was decreased.They were negatively correlated.TAZ overexpression reversed the diameter reduction of the myotube,downregulated phosphorylated Akt,and increased the expression of forkhead box O4 induced by myostatin.CONCLUSION Ultrasound can detect muscle atrophy of fetal clubfoot.TAZ and myostatin are involved in the pathological process of neurogenic clubfoot muscle atrophy.TAZ antagonizes myostatin-induced myotube atrophy,potentially through regulation of the Akt/forkhead box O4 signaling pathway.

Evaluation of right ventricular volume and systolic function in normal fetuses using intelligent spatiotemporal image correlation

BACKGROUND Heart defects are the most common congenital malformations in fetuses.Fetal cardiac structure and function abnormalities lead to changes in ventricular volume.As ventricular volume is an important index for evaluating fetal cardiovascular development,an effective and reliable method for measuring fetal ventricular volume and cardiac function is necessary for accurate ultrasonic diagnosis and effective clinical treatment.The new intelligent spatiotemporal image correlation(iSTIC)technology acquires high-resolution volumetric images.In this study,the iSTIC technique was used to measure right ventricular volume and to evaluate right ventricular systolic function to provide a more accurate and convenient evaluation of fetal heart function.AIM To investigate the value of iSTIC in evaluating right ventricular volume and systolic function in normal fetuses.METHODS Between October 2014 and September 2015,a total of 123 pregnant women received prenatal ultrasound examinations in our hospital.iSTIC technology was used to acquire the entire fetal cardiac volume with off-line analysis using QLAB software.Cardiac systolic and diastolic phases were defined by opening of the atrioventricular valve and the subsequent closure of the atrioventricular valve.The volumetric data of the two phases were measured by manual tracking and summation of multiple slices and recording of the right ventricular end-systolic volume and the right ventricular end-diastolic volume.The data were used to calculate the right stroke volume,the right cardiac output,and the right ejection fraction.The correlations of changes between the above-mentioned indices and gestational age were analyzed.The right ventricular volumes of 30 randomly selected cases were measured twice by the same sonographer,and the intraobserver agreement measurements were calculated.RESULTS Among the 123 normal fetuses,the mean right ventricular end-diastolic volume increased from 0.99±0.34 mL at 22 wk gestation to 3.69±0.36 mL at 35+6 wk gestation.The mean right ventricular end-systolic volume increased from 0.43±0.18 mL at 22 wk gestation to 1.36±0.22 mL at 35+6 wk gestation.The mean right stroke volume increased from 0.62±0.29 mL at 22 wk gestation to 2.33±0.18 mL at 35+6 wk gestation.The mean right cardiac output increased from 92.23±40.67 mL/min at 22 wk gestation to 335.83±32.75 mL/min at 35+6 wk gestation.Right ventricular end-diastolic volume,right ventricular end-systolic volume,right stroke volume,and right cardiac output all increased with gestational age and the correlations were linear(P<0.01).Right ejection fraction had no apparent correlation with gestational age(P>0.05).CONCLUSION Fetal right ventricular volume can be quantitatively measured using iSTIC technology with relative ease and high repeatability.iSTIC technology is expected to provide a new method for clinical evaluation of fetal cardiac function.