Journal of Life Science (생명과학회지)

Korean Society of Life Science (한국생명과학회)
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Wnt7b is Upregulated in Macrophages during Thymic Regeneration and Negatively Regulated by RANKL

흰쥐 가슴샘 재생과정 동안 대식세포에서 Wnt 7b의 발현증가 및 RANKL에 의한 발현조절

  • Kim, Jong-Gab (Department of Anatomy, School of Medicine, Pusan National University, Medical Research Center for Ischemic Tissue Regeneration, Pusan National University) ;
  • Kim, Sung-Min (Department of Anatomy, School of Medicine, Pusan National University, Medical Research Center for Ischemic Tissue Regeneration, Pusan National University) ;
  • Kim, Bong-Seon (Department of Anatomy, School of Medicine, Pusan National University) ;
  • Kim, Jae-Bong (Department of Anatomy, School of Medicine, Pusan National University) ;
  • Yoon, Sik (Department of Anatomy, School of Medicine, Pusan National University, Medical Research Center for Ischemic Tissue Regeneration, Pusan National University) ;
  • Bae, Soo-Kyung (Department of Anatomy, School of Medicine, Pusan National University, Medical Research Center for Ischemic Tissue Regeneration, Pusan National University)
  • 김종갑 (부산대학교 의학전문대학원) ;
  • 김성민 (부산대학교 의학전문대학원) ;
  • 김봉선 (부산대학교 의학전문대학원) ;
  • 김재봉 (부산대학교 의학전문대학원) ;
  • 윤식 (부산대학교 의학전문대학원) ;
  • 배수경 (부산대학교 의학전문대학원)
  • Published : 2007.07.30
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Abstract

Thymus can regenerate to its normal mass within 14 days after acute involution induced by cyclophosphamide (CY) in adult rat. Despite the established role of Wnt pathways in the process of thymus development, they have not yet been associated with the regeneration of adult thymus. The purpose of this study was to investigate whether Wnt7b, which is expressed in developing thymic epithelial cells rather than in thymocytes, is modulated during thymic regeneration in adult rat. Here, we show that Wnt7b expression was up-regulated in the regenerating thymus. Cells immunolabeled for the Wnt7b were identified as macrophages. Furthermore, Wnt7b gene expression was decreased by the treatment of receptor activator of NF-kappaB ligand (RANKL). Taken together, our results demonstrate that Wnt7b gene expression was increased in macrophages during thymic regeneration and negatively regulated by RANKL.

성체흰쥐의 경우 항암제인 싸이클로포스파마이드 (CY)처리로 퇴축된 가슴샘은 2주 후에 정상조직으로 재생된다. 가슴샘 발생과정에서 이미 알려진 Wnt신호전달의 중요성과는 달리 성체의 가슴샘 재생과정에서 그 역할에 관해서는 알려진 바 전혀 없다. 본 연구의 목적은 발생중인 가슴샘 상피세포에서 발현이 증가된다고 이미 알려져 있는 Wnt7b가 성체의 가슴샘재생과정에서 어떤 발현 양상을 보이는지를 조사하는 것이다. Wnt7b는 가슴샘의 급성 퇴축 이후 3일째 되는 시기에 mRNA와 단백질의 양이 급격히 증가 하였으며, 이중 면역 염색 형광법을 통해 큰포식 세포와 위치적 분포가 일치함을 확인하였다. 또한, Wnt7b유전자의 발현 조절 기전을 밝히기 위해 Wnt7b의 Reporter Vector를 제작하여 Luciferase assay를 이용하여 상위의 신호를 분석하였고, 그 결과 Wnt7b는 RANKL에 의해 그 발현이 감소된다는 사실을 처음으로 밝혔다. 따라서, 본 연구 결과들을 통해 Wnt 7b는 가슴샘의 급성 퇴축 초기 과정에서 나타나는 손상된 세포를 처리하는 큰포식 세포의 기능 조절에 관여할 것으로 생각된다.

Keywords

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