Stem cell autotomy and niche interaction in differentsystems

• 作者: David C Dorn August Dorn
• 来源期刊: 世界干细胞杂志：英文版（电子版）
• 学科: 医学
• 关键词: STEM cell-niche INTERACTION Male germlinestem cells SPERMATOGENESIS ERYTHROPOIESIS STEM cellautotomy Thrombopoiesis
• 年，卷（期）: 2015,（6）
• 页码范围: 922-944
• 页数: 23页
• 分类号: R

摘要

The best known cases of cell autotomy are theformation of erythrocytes and thrombocytes （platelets）from progenitor cells that reside in special niches.Recently, autotomy of stem cells and its enigmaticinteraction with the niche has been reported from malegermline stem cells （GSCs） in several insect species.First described in lepidopterans, the silkmoth, followedby the gipsy moth and consecutively in hemipterans,foremost the milkweed bug. In both, moths and themilkweed bug, GSCs form finger-like projectionstoward the niche, the apical cells （homologs of thehub cells in Drosophila）. Whereas in the milkweedbug the projection terminals remain at the surfaceof the niche cells, in the gipsy moth they protrudedeeply into the singular niche cell. In both cases, theprojections undergo serial retrograde fragmentationwith progressing signs of autophagy. In the gipsy moth,the autotomized vesicles are phagocytized and digestedby the niche cell. In the milkweed bug the autotomizedvesicles accumulate at the niche surface and disintegrate.Autotomy and sprouting of new projectionsappears to occur continuously. The significance of theGSC-niche interactions, however, remains enigmatic.Our concept on the signaling relationship betweenstem cell-niche in general and GSC and niche （hubcells and cyst stem cells） in particular has been greatlyshaped by Drosophila melanogaster. In comparingthe interactions of GSCs with their niche in Drosophilawith those in species exhibiting GSC autotomy itis obvious that additional or alternative modes ofstem cell-niche communication exist. Thus, essentialsignaling pathways, including niche-stem cell adhesion（E-cadherin） and the direction of asymmetrical GSCdivision - as they were found in Drosophila - can hardlybe translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomyof GSC projections shows remarkable similarities withWallerian axonal destruction, developmental axonpruning and dying-back degeneration in neurodegenerativediseases. Esp