Yanying Wang1, Pingping Zhu1, Jing Wang2, Xiaoxiao Zhu3, Jianjun Luo3, Shu Meng3, Jiayi Wu2, Buqing Ye1, Luyun He2, Ying Du1, Lei He4, Runsheng Chen5, Yong Tian6, Zusen Fan7. 1. CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. 2. CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. 3. CAS Key Laboratory of RNA Biology; Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. 4. Department of Hepatobiliary Surgery, PLA General Hospital, Beijing 100853, China. 5. University of Chinese Academy of Sciences, Beijing 100049, China; CAS Key Laboratory of RNA Biology; Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: crs@sun5.ibp.ac.cn. 6. University of Chinese Academy of Sciences, Beijing 100049, China; CAS Key Laboratory of RNA Biology; Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: ytian@sun5.ibp.ac.cn. 7. CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: fanz@moon.ibp.ac.cn.
Abstract
BACKGROUND & AIMS: Long noncoding RNAs (lncRNAs) play important roles in various biological processes, regulating gene expression by diverse mechanisms. However, how lncRNAs regulate liver repopulation is unknown. Herein, we aimed to identify lncRNAs that regulate liver repopulation and elucidate the signaling pathways involved. METHODS: Herein, we performed 70% partial hepatectomy in wild-type and gene knockout mice. We then performed transcriptomic analyses to identify a divergent lncRNA termed lncHand2 that is highly expressed during liver regeneration. RESULTS: LncHand2 is constitutively expressed in the nuclei of pericentral hepatocytes in mouse and human livers. LncHand2 knockout abrogates liver regeneration and repopulation capacity. Mechanistically, lncHand2 recruits the Ino80 remodeling complex to initiate expression of Nkx1-2 in trans, which triggers c-Met (Met) expression in hepatocytes. Finally, knockout of both Nkx1-2 and c-Met causes more severe liver injury and poorer repopulation ability. Thus, lncHand2 promotes liver repopulation via initiating Nkx1-2-induced c-Met signaling. CONCLUSIONS: Our findings reveal that lncHand2 acts as a critical mediator regulating liver repopulation. It does this by inducing Nkx1-2 expression, which in turn triggers c-Met signaling. LAY SUMMARY: Long noncoding RNAs play important roles in various biological processes. While long noncoding RNAs do not directly code proteins, they can regulate gene expression by diverse mechanisms. We identified the long noncoding RNA, termed lncHand2 because of its proximity to the gene Hand2, to be an important determinant of liver regeneration through c-Met signaling.
BACKGROUND & AIMS: Long noncoding RNAs (lncRNAs) play important roles in various biological processes, regulating gene expression by diverse mechanisms. However, how lncRNAs regulate liver repopulation is unknown. Herein, we aimed to identify lncRNAs that regulate liver repopulation and elucidate the signaling pathways involved. METHODS: Herein, we performed 70% partial hepatectomy in wild-type and gene knockout mice. We then performed transcriptomic analyses to identify a divergent lncRNA termed lncHand2 that is highly expressed during liver regeneration. RESULTS:LncHand2 is constitutively expressed in the nuclei of pericentral hepatocytes in mouse and human livers. LncHand2 knockout abrogates liver regeneration and repopulation capacity. Mechanistically, lncHand2 recruits the Ino80 remodeling complex to initiate expression of Nkx1-2 in trans, which triggers c-Met (Met) expression in hepatocytes. Finally, knockout of both Nkx1-2 and c-Met causes more severe liver injury and poorer repopulation ability. Thus, lncHand2 promotes liver repopulation via initiating Nkx1-2-induced c-Met signaling. CONCLUSIONS: Our findings reveal that lncHand2 acts as a critical mediator regulating liver repopulation. It does this by inducing Nkx1-2 expression, which in turn triggers c-Met signaling. LAY SUMMARY: Long noncoding RNAs play important roles in various biological processes. While long noncoding RNAs do not directly code proteins, they can regulate gene expression by diverse mechanisms. We identified the long noncoding RNA, termed lncHand2 because of its proximity to the gene Hand2, to be an important determinant of liver regeneration through c-Met signaling.