Histone lysine-specific demethylase 1 regulates the proliferation of hemocytes in the oyster Crassostrea gigas

• Published in: Frontiers in Immunology
• Main Authors: Gu, Xiaoyu, Qiao, Xue, Yu, Simiao, Song, Xiaorui, Wang, Lingling, Song, Linsheng
• Other Authors: National Key Research and Development Program of China
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Frontiers Media SA 2022
• Subjects: Pacific; Crassostrea gigas; Pacific oyster
• Online Access: http://dx.doi.org/10.3389/fimmu.2022.1088149; https://www.frontiersin.org/articles/10.3389/fimmu.2022.1088149/full

Background Lysine-specific demethylase 1 (LSD1) is an essential epigenetic regulator of hematopoietic differentiation, which can specifically mono-methylate H3K4 (H3K4me1) and di-methylate H3K4 (H3K4me2) as a transcriptional corepressor. Previous reports have been suggested that it participated in hematopoiesis and embryonic development process. Here, a conserved LSD1 ( Cg LSD1) with a SWIRM domain and an amino oxidase (AO) domain was identified from the Pacific oyster Crassostrea gigas . Methods We conducted a comprehensive analysis by various means to verify the function of Cg LSD1 in hematopoietic process, including quantitative real-time PCR (qRT-PCR) analysis, western blot analysis, immunofluorescence assay, RNA interference (RNAi) and flow cytometry. Results The qRT-PCR analysis revealed that the transcripts of Cg LSD1 were widely expressed in oyster tissues with the highest level in the mantle. And the transcripts of Cg LSD1 were ubiquitously expressed during larval development with the highest expression level at the early D-veliger larvae stage. In hemocytes after Vibrio splendidus stimulation, the transcripts of Cg LSD1 were significantly downregulated at 3, 6, 24, and 48 h with the lowest level at 3 h compared to that in the Seawater group (SW group). Immunocytochemical analysis showed that Cg LSD1 was mainly distributed in the nucleus of hemocytes. After the Cg LSD1 was knocked down by RNAi, the H3K4me1 and H3K4me2 methylation level significantly increased in hemocyte protein. Besides, the percentage of hemocytes with EdU-positive signals in the total circulating hemocytes significantly increased after V. splendidus stimulation. After RNAi of Cg LSD1, the expression of potential granulocyte markers Cg SOX11 and Cg AATase as well as oyster cytokine-like factor Cg Astakine were increased significantly in mRNA level, while the transcripts of potential agranulocyte marker Cg CD9 was decreased significantly after V. splendidus stimulation. Conclusion The above results demonstrated that Cg LSD1 was a ...