As a dioxygenase. Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hei-natopoi...As a dioxygenase. Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hei-natopoietic stem cells, but its impact on mature hematopoietic cells is not well-characterized. Here we show that Tet2 plays an essential role in osteoclastogenesis. Dele- tion of Tet2 impairs the differentiation of osteoclast precursor cells (macrophages) and their matu- ration into bone-resorbing osteoclasts in vitro. Furthermore, Tet2 / mice exhibit mild osteopetrosis, accompanied by decreased number of osteoclasts in vivo. Tet2 loss in macrophages results in the altered expression of a set of genes implicated in osteoclast differentiation, such as Cehpa, Mafb, and Nfkbiz. Tet2 deletion also leads to a genome-wide alteration in the level of 5-hydroxymethylcytosine (ShmC) and altered expression of a specific subset of macrophage genes associated with osteoclast differentiation. Furthermore, Tet2 interacts with Runxl and negatively modulates its transcriptional activity. Our studies demonstrate a novel molecular mechanism controlling osteoclast differentiation and function by Tet2, that is, through interactions with Runxl and the maintenance of genomie 5hmC. Targeting Tet2 and its pathway could be a potential therapeutic strategy for the prevention and t,'eatment of abnormal bone mass caused by the deregulation of osteoclast activities.展开更多
In the existing shearing processes for fabricating parts such as duplex gears, die roll is difficult to avoid. Accordingly, a method based on sheet-bulk metal forming for fabricating a duplex gear with extremely small...In the existing shearing processes for fabricating parts such as duplex gears, die roll is difficult to avoid. Accordingly, a method based on sheet-bulk metal forming for fabricating a duplex gear with extremely small die roll in one stroke is proposed in the current work. The process could be divided into three stages according to the forming features: upsetting and shearing stage, lateral extrusion stage, and local filling stage. The die roll appeared in the shearing stage, which could be reduced in the subsequent extrusion and local filling stages. To reveal the underground mechanism, material flows under two situations, as a key factor to influence the forming quality, were compared and investigated. The results revealed that by controlling material flow, one could avoid the defects and reduce the die roll.展开更多
基金supported by grants from the National Institutes of Health (Grant No. CA172408 to MX and FCY, Grant No. HL112294 to MX)the Leukemia & Lymphoma Society (LLS) (SCOR program to SN, FCY, and MX+7 种基金 translational grant to SN)University of Miami Sylvester Comprehensive Cancer Center (SCCC to MX and FCY), the United Statessupported by the Ministry of Science and Technology of China (Grant Nos. 2017YFA0103402to WY)National Natural Science Foundation of China (Grant Nos. 81629001 to MX, 81670102 to ZZ, 81600136 to YC, and 81421002 to WY)CAMS Innovation Fund for Medical Sciences (Grant Nos. 2017-I2M-3-015 to WY and 2016-I2M-1-017 to YC)Tianjin Application Foundation and Advanced Technology Research Program (Grant Nos. 16JCYBJC25200 to ZZ and 17JCQNJC09800 to YC)SKLEH-Pilot Research Grand (Grant No. ZK16-3 to ZZ)Peking Union Medical College Youth Fund (Grant No. 3332016092 to YC), China
文摘As a dioxygenase. Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hei-natopoietic stem cells, but its impact on mature hematopoietic cells is not well-characterized. Here we show that Tet2 plays an essential role in osteoclastogenesis. Dele- tion of Tet2 impairs the differentiation of osteoclast precursor cells (macrophages) and their matu- ration into bone-resorbing osteoclasts in vitro. Furthermore, Tet2 / mice exhibit mild osteopetrosis, accompanied by decreased number of osteoclasts in vivo. Tet2 loss in macrophages results in the altered expression of a set of genes implicated in osteoclast differentiation, such as Cehpa, Mafb, and Nfkbiz. Tet2 deletion also leads to a genome-wide alteration in the level of 5-hydroxymethylcytosine (ShmC) and altered expression of a specific subset of macrophage genes associated with osteoclast differentiation. Furthermore, Tet2 interacts with Runxl and negatively modulates its transcriptional activity. Our studies demonstrate a novel molecular mechanism controlling osteoclast differentiation and function by Tet2, that is, through interactions with Runxl and the maintenance of genomie 5hmC. Targeting Tet2 and its pathway could be a potential therapeutic strategy for the prevention and t,'eatment of abnormal bone mass caused by the deregulation of osteoclast activities.
基金the National Natural Science Foundation of China (Grant No. 51475296).
文摘In the existing shearing processes for fabricating parts such as duplex gears, die roll is difficult to avoid. Accordingly, a method based on sheet-bulk metal forming for fabricating a duplex gear with extremely small die roll in one stroke is proposed in the current work. The process could be divided into three stages according to the forming features: upsetting and shearing stage, lateral extrusion stage, and local filling stage. The die roll appeared in the shearing stage, which could be reduced in the subsequent extrusion and local filling stages. To reveal the underground mechanism, material flows under two situations, as a key factor to influence the forming quality, were compared and investigated. The results revealed that by controlling material flow, one could avoid the defects and reduce the die roll.