Dentin,the main component of dental hard tissues,is produced by differentiated odontoblasts.How odontoblast differentiation is regulated remains understudied.Here,we screen that the expression of membrane-associated R...Dentin,the main component of dental hard tissues,is produced by differentiated odontoblasts.How odontoblast differentiation is regulated remains understudied.Here,we screen that the expression of membrane-associated RING finger protein 2(March2) is the highest among all March family members,with an increasing trend during odontoblast differentiation.In mouse incisors and molars,MARCH2 is moderately expressed in the undifferentiated dental papilla cells and strongly expressed in the odontoblasts.Knockdown and overexpression experiments demonstrate that MARCH2 inhibits odontoblastic differentiation of mouse dental papilla cells(mDPCs).Additionally,both March2 deficient mice and mice with odontoblast specific knockdown of March2 exhibit the phenotype of increased dentin thickness,accelerated dentin deposition as well as elevated expression levels of odontoblast markers compared with control littermates.Therefore,MARCH2 plays an inhibitory role in odontoblast differentiation.Mechanistically,MARCH2 interacts with protein tyrosine phosphatase receptor delta(PTPRD) and facilitates its K27-linked polyubiquitination and subsequent degradation,which is dependent on the ligase activity of MARCH2.The presence of MARCH2promotes the translocation of PTPRD from the cell membrane to the lysosome,thereby enhancing its degradation via the lysosomal pathway.Further experiments show that knockdown of endogenous Ptprd impairs odontoblastic differentiation of mDPCs.Ptprd and March2 double knockdown in mDPCs apparently reversed the enhanced odontoblastic differentiation by knockdown of March2 alone,indicating that MARCH2 inhibits odontoblastic differentiation by promoting PTPRD degradation.This study unveils a novel mechanism where an E3 ubiquitin ligase regulates odontoblast differentiation through post-translational modification of a membrane protein,highlighting a promising direction for future exploration.展开更多
目的:探讨过表达MARCH2对肝细胞癌HUH7细胞自噬水平和生长的影响及其机制。方法:MTS和EDU检测MARCH2过表达的肝细胞癌HUH7细胞的生长情况。流式细胞术检测MARCH2过表达的肝细胞癌HUH7细胞凋亡、细胞周期的情况。Western blot和激光共聚...目的:探讨过表达MARCH2对肝细胞癌HUH7细胞自噬水平和生长的影响及其机制。方法:MTS和EDU检测MARCH2过表达的肝细胞癌HUH7细胞的生长情况。流式细胞术检测MARCH2过表达的肝细胞癌HUH7细胞凋亡、细胞周期的情况。Western blot和激光共聚焦法检测MARCH2过表达的肝细胞癌HUH7细胞自噬水平。结果:MTS和EDU检测表明,MARCH2的过表达促进了肝细胞癌HUH7的生长。流式细胞术检测表明,MARCH2过表达对肝细胞癌HUH7细胞凋亡和细胞周期没有明显影响。进一步的实验表明,MARCH2过表达损害了肝细胞癌HUH7的自噬。用常见的自噬诱导剂雷帕霉素挽救自噬可以使肝细胞癌HUH7的增殖率恢复到控制水平。结论:我们的数据表明,MARCH2通过抑制自噬在肿瘤发展过程中起着至关重要的作用。因此,MARCH2是一种有前景的肿瘤治疗新靶点。Aims: To investigate the effects and mechanisms of overexpression of MARCH2 on autophagy levels and growth of hepatocellular carcinoma HUH7 cells. Methods: MTS and EDU were used to detect the growth of MARCH2 overexpressing hepatocellular carcinoma HUH7 cells. Flow cytometry was used to detect apoptosis and cell cycle in MARCH2 overexpressing hepatocellular carcinoma HUH7 cells. Western blot and laser confocal microscopy were used to detect the autophagy levels in MARCH2 overexpressing HUH7 hepatocellular carcinoma cells. Results: In this study, MTS and EDU assays showed that the overexpression of MARCH2 promoted the growth of hepatocellular carcinoma HUH7 cells. Flow cytometry detection illustrated that MARCH2 overexpression had no obvious effect on the hepatocellular carcinoma HUH7 cell apoptosis and cell cycle. Further experiments displayed that MARCH2 overexpression impaired the autophagy of hepatocellular carcinoma HUH7 cells. Rescued autophagy with the common autophagy inducer rapamycin can bring the proliferation rate of hepatocellular carcinoma HUH7 cells back to the control level. Conclusions: Our data indicates that MARCH2 plays an essential role in the progression of tumor development through inhibiting autophagy. Therefore, MARCH2 is an attractive novel target for tumor therapy.展开更多
3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be effi...3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be efficient and stable. However, it has low calculation accuracy near the source, which thus gives it low overall accuracy. This paper proposes a joint traveltime calculation method to solve this problem. The method firstly employs the wavefront construction method （WFC）, which has a higher calculation accuracy than FMM in calculating traveltime in the small area near the source, and secondly adopts FMM to calculate traveltime for the remaining grid nodes. Due to the increase in calculation precision of grid nodes near the source, this new algorithm is shown to have good calculation precision while maintaining the high calculation efficiency of FMM, which is employed in most of the computational area. Results are verified using various numerical models.展开更多
基金supported by grants from the National Natural Science Foundation of China (82370913,82170914 to Guohua Yuan and 82270947 to Guobin Yang)the National Natural Science Foundation of China Key Program (82230029 to Z.C)+1 种基金the Fundamental Research Funds for the Central Universities (2042022dx0003)the Innovation Project of Municipal Science and Technology Bureau (2023020201010170) to Guohua Yuan。
文摘Dentin,the main component of dental hard tissues,is produced by differentiated odontoblasts.How odontoblast differentiation is regulated remains understudied.Here,we screen that the expression of membrane-associated RING finger protein 2(March2) is the highest among all March family members,with an increasing trend during odontoblast differentiation.In mouse incisors and molars,MARCH2 is moderately expressed in the undifferentiated dental papilla cells and strongly expressed in the odontoblasts.Knockdown and overexpression experiments demonstrate that MARCH2 inhibits odontoblastic differentiation of mouse dental papilla cells(mDPCs).Additionally,both March2 deficient mice and mice with odontoblast specific knockdown of March2 exhibit the phenotype of increased dentin thickness,accelerated dentin deposition as well as elevated expression levels of odontoblast markers compared with control littermates.Therefore,MARCH2 plays an inhibitory role in odontoblast differentiation.Mechanistically,MARCH2 interacts with protein tyrosine phosphatase receptor delta(PTPRD) and facilitates its K27-linked polyubiquitination and subsequent degradation,which is dependent on the ligase activity of MARCH2.The presence of MARCH2promotes the translocation of PTPRD from the cell membrane to the lysosome,thereby enhancing its degradation via the lysosomal pathway.Further experiments show that knockdown of endogenous Ptprd impairs odontoblastic differentiation of mDPCs.Ptprd and March2 double knockdown in mDPCs apparently reversed the enhanced odontoblastic differentiation by knockdown of March2 alone,indicating that MARCH2 inhibits odontoblastic differentiation by promoting PTPRD degradation.This study unveils a novel mechanism where an E3 ubiquitin ligase regulates odontoblast differentiation through post-translational modification of a membrane protein,highlighting a promising direction for future exploration.
文摘目的:探讨过表达MARCH2对肝细胞癌HUH7细胞自噬水平和生长的影响及其机制。方法:MTS和EDU检测MARCH2过表达的肝细胞癌HUH7细胞的生长情况。流式细胞术检测MARCH2过表达的肝细胞癌HUH7细胞凋亡、细胞周期的情况。Western blot和激光共聚焦法检测MARCH2过表达的肝细胞癌HUH7细胞自噬水平。结果:MTS和EDU检测表明,MARCH2的过表达促进了肝细胞癌HUH7的生长。流式细胞术检测表明,MARCH2过表达对肝细胞癌HUH7细胞凋亡和细胞周期没有明显影响。进一步的实验表明,MARCH2过表达损害了肝细胞癌HUH7的自噬。用常见的自噬诱导剂雷帕霉素挽救自噬可以使肝细胞癌HUH7的增殖率恢复到控制水平。结论:我们的数据表明,MARCH2通过抑制自噬在肿瘤发展过程中起着至关重要的作用。因此,MARCH2是一种有前景的肿瘤治疗新靶点。Aims: To investigate the effects and mechanisms of overexpression of MARCH2 on autophagy levels and growth of hepatocellular carcinoma HUH7 cells. Methods: MTS and EDU were used to detect the growth of MARCH2 overexpressing hepatocellular carcinoma HUH7 cells. Flow cytometry was used to detect apoptosis and cell cycle in MARCH2 overexpressing hepatocellular carcinoma HUH7 cells. Western blot and laser confocal microscopy were used to detect the autophagy levels in MARCH2 overexpressing HUH7 hepatocellular carcinoma cells. Results: In this study, MTS and EDU assays showed that the overexpression of MARCH2 promoted the growth of hepatocellular carcinoma HUH7 cells. Flow cytometry detection illustrated that MARCH2 overexpression had no obvious effect on the hepatocellular carcinoma HUH7 cell apoptosis and cell cycle. Further experiments displayed that MARCH2 overexpression impaired the autophagy of hepatocellular carcinoma HUH7 cells. Rescued autophagy with the common autophagy inducer rapamycin can bring the proliferation rate of hepatocellular carcinoma HUH7 cells back to the control level. Conclusions: Our data indicates that MARCH2 plays an essential role in the progression of tumor development through inhibiting autophagy. Therefore, MARCH2 is an attractive novel target for tumor therapy.
基金supported by NSFC(Nos.41274120,41404085,and 41504084)
文摘3D traveltime calculation is widely used in seismic exploration technologies such as seismic migration and tomography. The fast marching method （FMM） is useful for calculating 3D traveltime and has proven to be efficient and stable. However, it has low calculation accuracy near the source, which thus gives it low overall accuracy. This paper proposes a joint traveltime calculation method to solve this problem. The method firstly employs the wavefront construction method （WFC）, which has a higher calculation accuracy than FMM in calculating traveltime in the small area near the source, and secondly adopts FMM to calculate traveltime for the remaining grid nodes. Due to the increase in calculation precision of grid nodes near the source, this new algorithm is shown to have good calculation precision while maintaining the high calculation efficiency of FMM, which is employed in most of the computational area. Results are verified using various numerical models.
