178 research outputs found
Physiological pathway of differentiation of hematopoietic stem cell population into mural cells
Endothelial cells (ECs), which are a major component of blood vessels, have been reported to develop in adulthood from hematopoietic cell populations, especially those of the monocyte lineage. Here we show that mural cells (MCs), another component of blood vessels, develop physiologically during embryogenesis from a hematopoietic stem cell (HSC) population, based on the in vitro culture of HSCs and histological examination of acute myeloid leukemia 1 mutant embryos, which lack HSCs. As in the embryo, HSCs in adult bone marrow differentiate into CD45+CD11b+ cells before differentiating into MCs. Moreover, CD45+CD11b+ cells are composed of two populations, CD11bhigh and CD11blow cells, both of which can differentiate into MCs as well as ECs. Interestingly, in a murine ischemia model, MCs and ECs derived from the CD11blow population had a long-term potential to contribute to the formation of newly developed blood vessels in vivo compared with the CD11high population, which could not. Moreover, injection of the CD11bhigh population induced leaky blood vessels, but the CD11blow population did not. With respect to the permeability of vessels, we found that angiopoietin 1, which is a ligand for Tie2 receptor tyrosine kinase expressed on ECs and is suggested to induce cell adhesion between ECs and MCs, is produced by the CD11blow population and plays a critical role in the formation of nonleaky vessels. These observations suggested that the CD11low cell population serves as a good source of cells for in vivo blood vessel regeneration
Contribution of hematopoietic stem cells in blood vessel formation
Vascular development consists of vasculogenesis and angiogenesis. The system of TIE2-Angiopoietin (Ang) is involved in angiogenesis. TIE2 regulates adhesion and dissociation between endothelial cells and mural cells, and survival, apoptosis, and chemotaxis of endothelial cells. Ang-2, which is produced by endothelial cells under tissue hypoxia, has been suggested to be a key regulator for the initiation of endothelial cell sprouting from pre-existing vessels. Although Ang-2 binds to TIE2, it does not promote activation of TIE2 on endothelial cells. Ang-2 produced from endothelial cells under hypoxia inhibits the binding of Ang-1 to TIE2. On the other hand, Ang-1 promotes activation of TIE2 and adhesion between endothelial cells and mural cells. Therefore, endothelial cells dissociated from mural cells by Ang-2 are free to move to avascular area where oxygen or nutrient is needed. We recently found that hematopoietic stem cells produce Ang-1 and promote chemotaxis and network formation of TIE2-positive endothelial cells. Moreover, hematopoietic stem cells change their fate into mural cell and stabilize the vessel structure. This novel function may be applied clinically to promote neovascularization by transplanting the hematopoietic stem cells at the desired site.Biomedical Reviews 2003; 14: 1-8
ãã现èã®ãã幹现èåã«ãããåååºç€ã®è§£æãšãã®å¶åŸ¡
é沢倧åŠå»è¬ä¿å¥ç 究åå»åŠç³»è¿å¹Žãåºåœ¢ããã¯åäžã®ãã现èéå£ã«ãã圢æãããŠããã®ã§ã¯ãªããå€å€èæ§èœãæãããã幹现èãšããããååãéå°å¢æ®ãããããããã现èã«ãã£ãŠåœ¢æãããŠããããšã解æãããŠããããã®ããšã¯ãããæ²»çã«ãããããéçž®åŸã®åçºæ©æ§ã«ãã幹现èã®è²¢ç®æ§ãé«ãããšã瀺åãããã幹现èãã¿ãŒã²ãããšããããæ²»çæ³ã®éçºã®éèŠæ§ãèæ
®ãããããããçŸåšããã现èããããªãååæ©åºã«ãããã幹现èåããã®ãã«ã€ããŠã¯å
šãäžæã®ãŸãŸã§ãããããã§ãæäœå
ã®çµç¹çŽ°èãšå¹¹çŽ°èã®çŽ°èèåã®ã¡ã«ããºã ã«çç®ãããã现èãšãé è¡å¹¹çŽ°èãšã®çŽ°èèåã«ãããã现èã®ãã幹现èåã®å¯èœæ§ã«ã€ãæ€èšãããæšå¹ŽåºŠãè©Šéšç®¡å
ã§ã¯é è¡å¹¹çŽ°èãšã¡ã©ããŒã现èæ ªB16ã®æ··åå¹é€ã«ãããè¡æ¶²çŽ°èãšèåããB16现èãã10-10^3åã§ãããŠã¹ã«è
«çã圢æãããããšããããã®èåãã现èã®æªæ§åã瀺ããããæ¬å¹ŽåºŠã¯çäœå
ã§åæ§ã®çŸè±¡ãçãããåŠããæ€èšãããCATéºäŒåãLoxPã§ãµã³ãã€ããã«ããã³ã³ã¹ãã©ã¯ãã®äžæµã«GFPãé£çµããéºäŒåãCAGããã¢ãŒã¿ãŒã®å¶åŸ¡äžã§çºçŸããçºçŸãã©ã¹ãããäœæãB16现èã«éºäŒåå°å
¥ããã次ã«ã¢ã¯ãã³ããã¢ãŒã¿ãŒå¶åŸ¡äžã§Creãªã³ã³ãããŒã¹ãçºçŸããããŠã¹ç±æ¥ã®éªšé«ãçšããŠãéçåããŠã¹ã®éªšé«ãåæ§ç¯ãããããŠã¹ãäœè£œããããã®ããŠã¹ã«å
ã®CAT-Floxed-GFPãçºçŸãããB16现èã移æ€ãããšãããäžéšã®B16现èã«GFPãçºçŸãã现èãåºçŸããããã®GFPéœæ§B16现èãååããå床10åã®çŽ°èãããŠã¹ã«ç§»æ€ãããšãGFPéœæ§ãšé°æ§ã®B16现èã«ããè
«ç圢æãèªå°ãããããã®ããšã¯éªšé«çŽ°èãšè
«ç现èãèåãã现èã¯ãéåžžã«å
å°ã®çŽ°èã§ãããåæ§ç¯ã§ããããšãæå³ãããããããã幹现èãšããŠã®åœ¢è³ªãç²åŸããããšã瀺åããããç 究課é¡/é åçªå·:17659091, ç 究æé(幎床):2005 â 2006åºå
žïŒããã现èã®ãã幹现èåã«ãããåååºç€ã®è§£æãšãã®å¶åŸ¡ãç 究ææå ±åæžã課é¡çªå·17659091ïŒKAKENïŒç§åŠç 究費å©æäºæ¥ããŒã¿ããŒã¹ïŒåœç«æ
å ±åŠç 究æïŒïŒïŒhttps://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-17659091/)ãå å·¥ããŠäœ
é è¡å¹¹çŽ°èã®å¯å¡æ§ãèªå°ããç°å¢å åã®åå®ãšåçå»çãžã®å¿çš
é沢倧åŠããé²å±å¶åŸ¡ç 究æèèªçµç¹ã¯éªšé«ãšåæ§ãéåžžã«ç·»å¯ãªè¡ç®¡ç¶²ã®æ§ç¯ããªãããŠããããŸãèèªçµç¹ã«ååšããéè系现èã®äºåç»ã¯ããã¡ããèèªçŽ°èã«ååãããã®ã®ããã®ä»è¡ç®¡å
ç®çŽ°èãéªšæ Œç现èãç¥çµçŽ°èãªã©ãžã®ååèœãæããããšããããããŠãããããããå®éã«èèªçµç¹å
ã«ååšããéã«ã¯ãããã®å¹¹çŽ°èã¯çš®ã
ã®èåšçŽ°èãžã®ååã¯æå¶ãããŠããããã®èèªçµç¹äžã«ã¯éåžžã¯å¹¹çŽ°èã®å¯å¡æ§ãæå¶ããååãååšããå¯èœæ§ã瀺åããããããã§å¹¹çŽ°èã®å¯å¡æ§ã®å¶åŸ¡ã解æããäžã§ãèèªçµç¹ã¯ããææãšãªããšèãããèèªçµç¹ã®è©Šéšç®¡å
ç¶æå¹é€ç³»ã®ç¢ºç«ãè©Šã¿ãããã®çµæãäºæ³ããªãããšã«ãæã
ã®å¹é€ç³»ã§ã¯èèªçµç¹ããéåžžã«è±å¯ã«beatingããå¿ç现èãååããããšãå€æããããããå¿ç现èã¯Î±-sarcomeric proteinãNkh2.5ãªã©å¿çç¹ç°çãªçŽ°èéªšæ Œååã転åå åãçºçŸããŠããããããå¹é€ããå¿ç现èãå®éãå¿çæ¢å¡ã¢ãã«ã©ããã®å¿èãžççããå¿çèè¡ãæ¹åãããããšãå¯èœã§ããããšãå€æãããä»åã®ç 究æéã§ã¯ãŸã æããã«ããããšãã§ããªãã£ãããä»åŸãããªã现èåç»ãå¿ç现èã«ååãããã®ãããããŠèèªçµç¹ã®å¹é€ç³»ã§ã¯ãããªãååãèèªçµç¹å
ã®ãããã幹现èåç»ãšèãããã现èãå¿ç现èãžãšåå転æãããã®ãã解æãããããŸããåè¿°ããããã«äœå
ã«ååšããèèªçµç¹å
ã§ã¯å¿ç现èã«ååãæå¶ããååãååšããããšãäºæ³ãããæ¬ååãæ確ã«ããããšã§ããã®ååã®æ©èœæå¶ã«ããéè系幹现èãå¿ç现èãžå®¹æã«ååãããããšã®ã§ããå¹é€ç³»ãæš¹ç«ããå¿çæ¢å¡ãªã©éå·ã®å¿çŸæ£ã«å¯Ÿããæ°èŠã®æ²»çæŠå¿µã確ç«ããããç 究課é¡/é åçªå·:14657244, ç 究æé(幎床):2002 â 2003åºå
žïŒãé è¡å¹¹çŽ°èã®å¯å¡æ§ãèªå°ããç°å¢å åã®åå®ãšåçå»çãžã®å¿çšãç 究ææå ±åæžã課é¡çªå·14657244ïŒKAKENïŒç§åŠç 究費å©æäºæ¥ããŒã¿ããŒã¹ïŒåœç«æ
å ±åŠç 究æïŒïŒïŒhttps://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-14657244/)ãå å·¥ããŠäœ
é è¡å¹¹çŽ°èã®çºçã»èªå·±è€è£œã«é¢ããååã¯ããŒãã³ã°ãšãã®æ©èœè§£æ
é沢倧åŠããç 究æé è¡å¹¹çŽ°èãçšããåçå»çãžã®å¿çšã®ãããå¹çã®ãã幹现èã®è©Šéšç®¡å
å¢å¹
ã«ããé è¡å¹¹çŽ°èã®æªååæ§ã®ç¶æãèªå·±è€è£œçã®å¹¹çŽ°èæ§ã®ç¶æã®ååæ©åºãæã
ã以åããé è¡å¹¹çŽ°èãè¡ç®¡å
ç®çŽ°èã«å
±ã«çºçŸãã幹现èã®å¢æ®æ©æ§ã«é¢äžããããšããã®ããã¯ã¢ãŠãããŠã¹ã«ãããŠè§£æããŠããã¬ã»ãã¿ãŒåããã·ã³ãããŒãŒTIE2ã®æ©èœè§£æãäžå¿ã«è¡ãªã£ããèå
èãæäœéªšé«ãªã©é è¡çµç¹ã§ã¯é è¡å¹¹çŽ°èã®å¢æ®ãè¡ç®¡å
ç®çŽ°èè¿åã§çããããšãæããã«ãªã£ãããããé è¡å¹¹çŽ°èã¯TIE2ã°ããã§ãªãTIE2ã®çµåå åã¢ã³ãžãªããšãã³-1(Ang1)ãåæ³ããããšãå€æãããããã§TIE2ãæåžžçã«æŽ»æ§åããTIE2ã®å€ç°cDNAãäœæãTIE2ã®è©³çŽ°ãªæ©èœã解æããããã®çµæTIE2ã®æŽ»æ§åã¯çŽ°èæ»ã®æå¶ã现èåšæã®é
延åã现èå€ãããªãã¯ã¹ãžã®çŽ°èæ¥çã®å¢åŒ·ãèªå°ããããšãå€æãããããã«ãTIE2ã掻æ§åããè¡ç®¡å
ç®çŽ°èãšè¡æ¶²çŽ°èã¯éžæçã«æ¥çããããšãæããã«ãªããé è¡å¹¹çŽ°èã®åæ³ããAng1ãå
ç®-é è¡å¹¹çŽ°èéã®æ¥çã«é¢äžãããããåŒãéãšãªã幹现èã®èªå·±è€è£œãèªå°ããããšèå¯ãããã以äžã®ç 究çµæã«ç«èããTIE2ã®æŽ»æ§åã«ããå¶åŸ¡ããããååã«ã€ããã€ã¯ãã¢ã¬ã€æ³ãçšããŠè€æ°ã®éºäŒååé¢ã«æåãããæã
ãE11ãšåŒã¶æ°èŠã®è»¢åå åã¯æ¥µã
ã®èåšã®å¹¹çŽ°èã¬ãã«ã®çŽ°èã«çºçŸããæ¬éºäŒåã®ããã¯ã¢ãŠãããŠã¹ã§ã¯é è¡å¹¹çŽ°èã®çºçãã9.5æ¥ç®ã«ã¯ãã§ã«èçèŽæ»ã§ããããšãå€æãããä»åŸé è¡çŽ°èç¹ç°çãªE11ã®ããã¯ã¢ãŠãããŠã¹ãäœæããŠé è¡å¹¹çŽ°èã«ãããæ©èœã詳现ã«ããããŸãã幹现èãè¡ç®¡å
ç®çŽ°èã®æ¥çã«é¢ãããšèããããååã®åè£ãšããŠgalectin-3ãåé¢ãããä»åŸgalectin-3ãTDB2éºäŒåã®ããã¢ãŒã¿ãŒå¶åŸ¡äžã§éå°çºçŸããããŠã¹ãäœæããé è¡å¹¹çŽ°èæ§ã«äžãã圱é¿ã芳å¯ãããFor regeneration therapy using hematopoietic stem cells(HSCs), it is necessary to expand HSCs in vitro effectively. We tried to analyze the self-renewal and maintenance of immature phenotype so called, "HSC\u27s stemness" for in vitro expansion of HSCs. In this experiment, we focused on receptor tyrosine kinase, TIE2,which is expressed on both HSCs and endothelial cells(ECs).We found that proliferation of HSCs are observed near ECs forming capillary in hematopoietic organ, such as fetal liver, bone marrow and so on and such HSCs produce angiopoietin-1(Ang1), a ligand for TIE2. Then, we analyzed the function of TIE2 for sternness by using constitutively active form of TIE2. Result showed that TIE2 activation promote several kinds of biological phenomena such as anti-apoptosis, delay of cell cycle, and enhancement of cell adhesion to matrix. Moreover, upon an activation of TIE2 on ECs and hematopoietic cells(HCs), those cells selectively adhered with each other tightly. This suggests that Ang1 from HSCs stimulates TIE2 on both HSCs and ECs in the foci and becomes trigger for cell adhesion and stemness of HSCs.Based on these experiments, we tried to isolate TIE2 activation associating gene using micro-array methods and obtained several candidate genes. E11, a novel gene of putative transcriptional factor, expresses on several stem cells in variety of organ and targeted disruption of this gene led to early embryonic lethality before HSCs develop. We will try to establish knock out mice those have HSCs specifically disrupted of E11 gene and analyze this gene in hematopoiesis precisely. Moreover, we isolated a candidate gene, galectin-3, that may associate with cell adhesion between HSCs and ECs. We have started to generate a transgenic mice expressing galectin-3 on HSCs and ECs under the transcriptional control of TIE2 promoter and will analyze the stemness of HSCs using this mice.ç 究課é¡/é åçªå·:13470207, ç 究æé(幎床):2001 â 2003åºå
žïŒãé è¡å¹¹çŽ°èã®çºçã»èªå·±è€è£œã«é¢ããååã¯ããŒãã³ã°ãšãã®æ©èœè§£æãç 究ææå ±åæžã課é¡çªå·13470207ïŒKAKENïŒç§åŠç 究費å©æäºæ¥ããŒã¿ããŒã¹ïŒåœç«æ
å ±åŠç 究æïŒïŒïŒhttps://kaken.nii.ac.jp/ja/report/KAKENHI-PROJECT-13470207/134702072003kenkyu_seika_hokoku_gaiyo/)ãå å·¥ããŠäœ
- âŠ