Luo Wang, Zhang Fang, Zhao Fangzhen, Fang Yang, Zhao Long, Su Ying
Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education) and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
J Mol Cell Biol. 2025 Mar 21;16(9). doi: 10.1093/jmcb/mjae028.
Drosophila melanogaster crystal cells are a specialized type of blood cells for the innate immune process upon injury. Under normal conditions, crystal cells rarely proliferate and constitute a small proportion of fly blood cells. Notch signaling has been known to guide the cell fate determination of crystal cells and maintain their survival. Here, we reported that protein phosphatase V (PpV), the unique catalytic subunit of protein phosphatase 6 in Drosophila, is a novel regulator of crystal cell proliferation and integrity. We found that PpV proteins highly accumulated in crystal cells in the larval hematopoietic organ termed the lymph gland. Silencing PpV using RNA interference led to increased crystal cell proliferation in a Notch-independent manner and induced crystal cell rupture dependent on Notch signaling. Moreover, additive PpV prevented the rupture of crystal cells in lymph glands upon a needle injury, suggesting the involvement of PpV in wound healing. Altogether, our results indicated that PpV plays a dual role in lymph glands, preventing crystal cell proliferation to limit the cell number, as well as inhibiting crystal cell rupture to maintain their survival.
黑腹果蝇的晶细胞是损伤后先天免疫过程中的一种特殊血细胞类型。在正常情况下，晶细胞很少增殖，在果蝇血细胞中占比很小。已知Notch信号传导可指导晶细胞的细胞命运决定并维持其存活。在此，我们报道了蛋白磷酸酶V（PpV），即果蝇中蛋白磷酸酶6的唯一催化亚基，是晶细胞增殖和完整性的新型调节因子。我们发现PpV蛋白在幼虫造血器官即淋巴腺的晶细胞中高度积累。使用RNA干扰沉默PpV会以不依赖Notch的方式导致晶细胞增殖增加，并诱导依赖Notch信号传导的晶细胞破裂。此外，添加PpV可防止针刺损伤后淋巴腺中的晶细胞破裂，表明PpV参与伤口愈合。总之，我们的结果表明PpV在淋巴腺中发挥双重作用，防止晶细胞增殖以限制细胞数量，同时抑制晶细胞破裂以维持其存活。
