ãããªã³ã管çºçéçšã®è§£æ
ããèã§ã©ã®ããã«ãªã³ã管ãã§ããŠããã®ãã解æ
ãããªã³ã管ã®èåšããšã®å€æ§ãªçºçãéèãšãªã³ã管ã®æ¥åéš(éèè§)ã®çºçéçšã解æ
ãããšããŠã¹èã§ã¯ããªã³ã管çºçã®ã¹ããŒã(æéçµé)ãå šãç°ãªã
æŠèŠ
ãäžé倧åŠå»åŠéšå»åŠç§Â 5 幎 山å£ç¿äžéã4 幎ååºå€èµãäžé倧åŠå€§åŠé¢å»åŠç³»ç ç©¶ç§ ä¿®åŸ©åçç çåŠÂ ç 究ç§å è¬åž«ã®äžžå±±åæãã¯ç ç蚺æã®æ®äœæ€äœã«å«ãŸããããèãéç©ããããã§ãªã³ã管ãã©ã®ããã«åœ¢æãããã®ãã解æããŸããã
ãç 究ã°ã«ãŒãã¯ãããŸã§ããããŠã¹ã䜿çšãããªã³ã管ã®ç±æ¥ãäœã®äžéš(é é žéšãã瞊é)ãšäžéšã§ç°ãªãããã®ç±æ¥ã®éããããã§ã®å 倩æ§ã®è管çŸæ£ã®åå ãšãªã£ãŠããå¯èœæ§ãªã©ãå ±åããŠããŸããããããããªã³ã管ã®çºçãçççãªåœ¹å²ã¯çš®å·®ãéåžžã«å€§ãããããã§å®éã«ãªã³ã管ãã©ã®ããã«åœ¢æãããã®ããããŠã¹ã®ç¥èŠããã®ãŸãŸããã«é©å¿ã§ããã®ãã©ããã¯è§£æãã¹ãåé¡ã§ããã
ãæ¬ç 究éçºèª²é¡ã§ã¯ã3ã8 é±ã®èãšÂ 9 é±ã®èå æšæ¬ã䜿çšããâ ãªã³ã管ãéé¡ã»ããŠã¹ãšåæ§ã«éèå ç®çŽ°èã®åå転æã§åœ¢æãããäºããâ¡äœäžéšãªã³ã管ãäœå¹¹éšã®ãªã³ã管ãšæ¯èŒããéåžžã«ãã£ãããšçºçããããšãâ¢éèè§ãåæãªã³ã管(ãªã³ãå¢)ãšç·äž»éèã®çµåéšã«ãªã³ã管ãšéèãå¢çããåŒã圢æãã圢æãããäºãâ£æ§ã ãªèåšããšã«ãªã³ã管ãã©ã®ããã«å€æ§ãªååžãç²åŸããã®ããæããã«ããŸããã
ãæ¬ç 究ã§ãããã§ã®ãªã³ã管åæçºçãæããã«ãªãããªã³ã管ã®é²åã»çºçããªã³ã管é¢é£çŸæ£(ãªã³ãæµ®è «ãè¥æºãå¿è¡ç®¡çŸæ£ãã¯ããŒã³ç ãå ææ§è管å¥åœ¢ãªã©)ã®ç æ 解æã«åœ¹ç«ã€ããšãæåŸ ãããŸãã
èæ¯
ããªã³ã管ã¯å šèº«ã«ååžããè管(åèãéèãæ¯çŽ°è¡ç®¡ãªã©)ã®Â 1 çš®ã§ãå ç«æ©èœãæµ®è «ã«é¢ããéèŠãªåšå®ã§ããæè¿ã§ã¯ããããŸã§ååšãæããã§ãªãã£ãè³ã骚ã«ããªã³ã管ãååžããäºãããããæ°ããªæ²»çæšçãšããŠãçç®ãããŠããŸãã
ããªã³ã管ãã©ã®ããã«åœ¢æãããã®ãã¯ã1 äžçŽä»¥äžã«æž¡ã£ãŠè°è«ã®ç¶ããŠããåé¡ã§ãããŒãã©ãã£ãã·ã¥ãããŠã¹èãçšããéºäŒç现èç³»è解æãããªã³ã管å ç®çŽ°è(lymphatic endothelial cells:LECs)ã¯ãéèå ç®çŽ°èããªã³ã管çºçã®ãã¹ã¿ãŒè»¢åå åã§ãã Prox1 ãçºçŸããåå転æããäºã§çºçããäºãæããã«ãªããŸããã
äžæ¹ã§ãçè ãã¯é é žéšã»çžŠéé åã§ã¯ãLECs ã第äžã»ç¬¬äºé°åŒã«ç±æ¥ããæªååãªäžèè系现è(å¿èåœé äžèè)ãããçããäºãæããã«ããŠãããLECs ã®ç±æ¥ã解ååŠçãªéšäœã«ããç°ãªãäºã§ãè管çŸæ£ãé é žéšã瞊éé åã«å¥œçºãããšèããŠããŸãã
ããªã³ã管ã¯ç¡¬éªšéé¡ããååšããŸããããã®è§£åã»çºçã»çççãªåœ¹å²ã¯çš®ã«ããå·®ã倧ããäºãç¥ãããŠããŸãããŸããå 倩æ§çŸæ£ãèããäžã§ã¯ãçºçã®é床(ããŠã¹ã¯çŽÂ 20 æ¥éã®åŠåš æéãããã§ã¯Â 280æ¥)ãææã»éºäŒçã»ãšããžã§ããã£ãã¯ãªåœ±é¿ã®åãããããèŠå®ããŠããå¯èœæ§ããããŸãããã®ãããéé¡ãããŠã¹ã¢ãã«ã§åŸãããç¥èŠããã®ãŸãŸããã«é©å¿ã§ããã®ãã©ããã¯è°è«ããããããã§ã®çºçéçšãç¥ãå¿ èŠããããŸãããããã§çè ãã¯ãç ç蚺æã®æ®äœæ€äœäžã«å«ãŸããããèãéç©ã 31 åäœã®ããè(3ïœ8 é±)ãšÂ 3 åäœã®Â 9 é±èå ãçšããŠãæ§ã ãªãªã³ã管ããŒã«ãŒãé§äœ¿ããäºã§ããªã³ã管åæçºçéçšãåèåšãžã®ãªã³ã管ååžç¶æ³ã解æããŸããã
ç 究å 容
éèã«ç±æ¥ãããªã³ã管å ç®çŽ°è
ããªã³ã管ã¯ãéºäŒåãæ¹å€ãããŒãã©ãã£ãã·ã¥ãããŠã¹èã®å®éšãããäž»ã«éèå ç®çŽ°èã®åå転æã«ãã圢æããããšèããããŠããŸãããã€ãŸããèçæã«ååšããç·äž»éè(åŸã«äžå€§éèãå éèæŽã圢æãã)å ç®çŽ°èã«ãªã³ã管ãžã®ååã«å¿ é ã®è»¢åå å(Prox1, Coup-TFII, Sox18)ãçºçŸãããªã³ã管å ç®çŽ°è(LECs)ãžãšåå転æãå šèº«ãžååžããªããæçããŸããçè ãã¯ãããçºçã®ã¹ããŒãžCarnegie Stage (CS) 12(å粟åŸçŽÂ 30 æ¥)ã§ç·äž»éèå ç®çŽ°èã«ãCoup-TF2, Prox1 ãçºçŸãLECs ãçããäºãæããã«ããŸãããCS13 ã§ãã®Â LECs ã¯ãäœå¹¹éšåŸæ¹ãžãšååžãåºãã€ã€ãåŸã ã«æ¯çŽ°ãªã³ã管網ã圢æããCS16 ã§ã¯äœå¹¹éšã«ç®¡è æ§é ãæãããªã³ãå¢(åæãªã³ã管)ã®åœ¢æãèªããŸããã
Â
é°åŒã«ç±æ¥ãããªã³ã管ã¯çºçããã£ãããšé²ã
ãçè ããããŠã¹èã§åå®ããå¿èåœé äžèèã«ç±æ¥ãããšèããããé°åŒå ã® LECs ã¯ãCS14-15 ä»è¿ã§åºçŸããŠããŸããããã®é°åŒã«ç±æ¥ãã LECs ã¯å°æ¥çã«é é žéšã瞊éé å(äœäžéš)ã®ãªã³ã管ã圢æããŸããããã®é åã§ç®¡è æ§é ãèªããããã®ã¯ãCS23ã9 é±ä»è¿ã§ãããã€ãŸããé é žéšé åã®LECs ã¯ç®¡è æ§é ã圢æãããŸã§ã«æ°é±éãã®éãLECs ãå€åšæ§ã«ãã(管è æ§é ãå°ãªã)ãçºçãéåžžã«ãã£ããã§ãããäžæ¹ã§èºãè žéèã®ãªã³ã管ã¯æéçµéãšãšãã«Â LECsã®æ°ã管è æ§é ãæã€ãªã³ã管ã®æ°ãå¢ããŠããŸããã
ãå 倩æ§ã®è管çŸæ£ã¯é é žéšé åã«å¥œçºããäºãç¥ãããŠããŸããããã®é é žéšé åã§ã®ãã£ãããšãããªã³ã管çºçããçŸæ£ã®çºçãæåæ§ã«äœããã®åœ±é¿ãäžããŠããã®ãããããŸãããè管å¥åœ¢ã§é »åºŠã®é«ãéºäŒåå€ç°ãã©ã®çºçã®ææã«çããã®ããçŸæ£ã®éç床ãåºãããè¡šçŸåãèŠå®ããå¯èœæ§ã瀺åãããŸãã
Â
Lympho-Venous Valve ã®åœ¢æ
ããªã³ã管ã¯ãé骚äžéèãšå é žéèã®åå²éšã«åæµããŸãããã®éšå(éèè§)ã«ã¯è¡æ¶²ããªã³ã管ã«éæµããäºãé²ãåŒæ§é (Lympho-Venous Valve)ãååšããŸããä»åã®ç 究ã§ã¯ããã® LymphoVenous Valve ã®çºçéçšãæããã«ãªããŸããã
ãç·äž»éèããåºèœããLECs ã¯Â CS16 ã§ãªã³ãå¢(åæã®åŸã®å€§ããªãªã³ã管)ã圢æããŸããCS18 ã§ã¯ããã®ãªã³ãå¢ãšç·äž»éèã®æ¥åéšã«ã¯ãçãªå è é¢ãžã®çãäžãããèªãããã®èšééšã¯ã¹ããŒãžãé²ãããšã«ãæŽã£ãåŒæ§é ã圢æããCS21ã9 é±ã§æŽã£ã圢ç¶ã®Â lympho-venous valve ã圢æããŠããäºãããããŸãã(å³Â 1)ã
èåšããšã®ãªã³ã管
ãæ¬ç 究ã§ã¯å¿èãèºãè èãè žéèã»è žç®¡ãé¡é¢ãªã©ã®ãªã³ã管çºçã®æŠç¥ãæããã«ããŸãããäžæ¹ã§ä»åã®è§£æã§çšããåšå®åœ¢ææ(3ã8 é±)èãšÂ 9 é±èå ã§ã¯èé«ã»è³åšèŸºãå®è³ªå ã«Â LECs ããªã³ã管ãèªããŸããã§ããã
ããããšããŠã¹ã®ãªã³ã管çºçã®æ¯èŒè¡šãšãããªã³ã管ãLympho-venous valves çºçã®ãŸãšãå³ãæ²èŒããŸãã(å³Â 2)ã
ä»åŸã®å±æ
ãä»åã®ç 究ã§ã¯ãâ ãªã³ã管ãéé¡ã»ããŠã¹ãšåæ§ã«éèå ç®çŽ°èã®åå転æã§æåã«åœ¢æãããäºãâ¡äœäžéšãªã³ã管ãäœå¹¹éšã®ãªã³ã管ãšæ¯èŒããéåžžã«ãã£ãããšçºçããããšãâ¢Lympho-venousvalve(éèè§)ãåæãªã³ã管(ãªã³ãå¢)ãšç·äž»éèã®å¢çã«åœ¢æãããäºãâ£æ§ã ãªèåšããšã«ãªã³ã管ãã©ã®ããã«å€æ§ãªååžãç²åŸããã®ããæããã«ãªããããã®ãªã³ã管é¢é£çŸæ£(ãªã³ãæµ®è «ãè¥æºãå¿è¡ç®¡çŸæ£ãã¯ããŒã³ç ãå ææ§è管å¥åœ¢ãªã©)ãç解ããäžã§ã®åºç€ç¥èŠãšãªã£ããšèããŸãã
çšèªè§£èª¬
éºäŒç现èç³»è解æïŒ
现èã«ç®å°ãã€ã(äŸãã°ãGFP ãªã©)ããã®çŽ°èã®åå課çšã远跡ããæè¡ã
Â
å¿èåœé äžèè(Cardiopharyngeal mesoderm; CPM):
è¿å¹Žæ°ãã«å®çŸ©ãããäžèèé åãåŽæ¿äžèèã沿軞äžèèãåœé èæ(çºçã®ç¹å®ã®ææ)ã«åœé äžèèã§æ··ããåã圢æãããããã®äžèèé åã«ç°åžžãèµ·ãããšé¡é¢ãšå¿èã®å 倩æ§çŸæ£(äŸãã°Â DiGeorge çå矀)ãèµ·ãããšèããããŠããã
Â
å 倩æ§è管å¥åœ¢:
äŸãã°ç¹å®é£æ²»æ§çŸæ£ã®å·šå€§ãªã³ã管å¥åœ¢(é žéšé¡é¢ç å€ãæå®é£ç  279)ã巚倧éèå¥åœ¢(é žéšé¡é¢ç å€ãæå®é£ç  280)ãªã©