The effect of predifferentiation for adequate periods in vitro on dental tissue regeneration in vivo was examined in this study. Although no significant increase in hard tissue-forming ability was conferred by predifferentiation of the DPSCs, predifferentiated DPSCs generated hard tissue closer to dentin. Besides, predifferentiated PDLSCs appeared to generate higher-quality and more tissue for dental regeneration than their undifferentiated counterparts.
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국문요약
치수 및 치주인대 줄기세포의 사전분화가 조직재생에 미치는 영향
연세대학교 대학원 치의학과 차 윤 선
지도교수: 송제선
줄기세포를 통한 조직재생을 위해서는 목표한 조직으로 재생되도록 적절한 세포를 분리해 세포 분화 및 성장에 필요한 환경을 형성하는 것이 필요하다. 특히 사전분화 과정은 기간이 길수록 줄기세포의 자가복제능은 줄어들지만, 다양한 세포로 분화될 수 있는 줄기세포가 특정 세포로 분화되도록 유도하기 때문에, 조직 재생에 직접적인 영향을 미치는 중요한 과정이다. 이미 골수유래 줄기세포의 다양한 사전분화 기간에 따른 조직재생 효과에 대해서는 여러 연구가 진행되었으나 사람의 치수 및 치주인대 줄기세포를 이용한 연구는 아직 없었다. 따라서 본 연구는 영구치 치수 및 치주인대 줄기세포를 각기 다른 기간 동안 사전분화시킨 뒤 조직재생에 미치는 영향에 대해 알 아보고자 하였다.
사람의 영구치에서 획득한 치수 줄기세포와 치주인대 줄기세포를 각각 0, 4, 8일간 사전분화시킨 뒤, 면역억제된 쥐에 이식하여 9주간 조직재생을 유도하였다. 이후 이식
체를 획득하여 재생된 조직에 대해 조직학적 분석, 알칼리성 인산가수분해효소 활성 (ALP activity), 역전사효소 중합효소 연쇄반응분석, 면역화학염색법을 시행하여 비교하 였다.
치수줄기세포의 경우, 사전분화시키지 않은 군과 비교해 사전분화시킨 군에서 새로 형성된 조직의 양은 차이가 없었으나, 더 높은 OC, DSPP 발현을 나타내 상아질에 더 가까운 조직이 재생되었음을 보여주었다.
치주인대줄기세포의 경우, 사전분화시키지 않은 군보다 사전분화시킨 군에서 더 많 은 양의 조직이 형성되었고, 높은 ALP activity를 나타냈다. 특히, 8일간 사전분화시킨 군에서는 POSTN, CP23, Col XII의 높은 발현을 보여, 백악질/치주인대 복합체에 더 가 까운 조직이 형성되었음을 나타내었다.
본 연구를 통해 사전분화시킨 치수 및 치주인대줄기세포로 재생된 조직의 특성을 이해할 수 있었고, 이는 향후 치수 및 치주인대 줄기세포의 사전분화과정을 이용한 치아조직의 재생에 대한 연구에 응용될 수 있을 것으로 기대한다.
핵심되는 말: 치수줄기세포, 치주인대줄기세포, 사전분화, 조직재생