Phagocytic activity of splenic macrophages is enhanced and accompanied by cytosolic alkalinization in TRPM7 kinase-dead mice.
Phagocytic activity of splenic macrophages is enhanced and accompanied by cytosolic alkalinization in TRPM7 kinase-dead mice.
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DOI：
10.1111/febs.15683
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发表时间：
2021-06
期刊：
影响因子：
--
通讯作者：
Kozak JA
中科院分区：
文献类型：
--
作者：
Beesetty P;Rockwood J;Kaitsuka T;Zhelay T;Hourani S;Matsushita M;Kozak JA
瞬时受体电位melastatin 7（TRPM 7）是一种独特的蛋白质，其作为阳离子通道以及丝氨酸/苏氨酸激酶起作用，并且在免疫细胞如淋巴细胞和巨噬细胞中高度表达。TRPM 7激酶死亡（KD）小鼠模型已被用于研究这种蛋白质在免疫细胞中的作用;这些动物显示中度脾肿大和异位造血。从KD小鼠分离的腹腔巨噬细胞中的基础TRPM 7电流幅度较高，但是在胞质Mg 2+洗脱后实现的最大电流没有不同。在本研究中，我们研究了脾和腹腔巨噬细胞中TRPM 7激酶失活的后果。我们使用荧光乳胶珠、pHrodo酵母聚糖生物颗粒和调理红细胞测量了脾巨噬细胞的基础吞噬活性。与WT细胞相比，KD巨噬细胞吞噬效率更高，基线钙水平略高。我们发现WT和KD巨噬细胞之间的钙池操作的Ca 2+内流没有明显差异。相比之下，KD巨噬细胞中的静息胞质pH值比WT中显著更碱性。药理学阻断钠-氢交换器1（NHE 1）逆转了KD巨噬细胞的胞质碱化和减少的吞噬作用。KD巨噬细胞中的基础TRPM 7通道活性在NHE 1阻断后也降低。在WT和KD小鼠中，在腹腔巨噬细胞中测量的TRPM 7通道的胞质Mg 2+敏感性相似。KD巨噬细胞中较高的基础TRPM 7通道活性可能是由于碱化。我们的研究结果确定了TRPM 7激酶作为基础吞噬抑制剂和细胞pH调节剂的新作用。
Transient receptor potential melastatin 7 (TRPM7) is a unique protein functioning as a cation channel as well as a serine/threonine kinase and is highly expressed in immune cells such as lymphocytes and macrophages. TRPM7 kinase-dead (KD) mouse model has been used to investigate the role of this protein in immune cells; these animals display moderate splenomegaly and ectopic hemopoiesis. The basal TRPM7 current magnitudes in peritoneal macrophages isolated from KD mice were higher, however the maximum currents, achieved after cytoplasmic Mg2+ washout were not different. In the present study, we investigated the consequences of TRPM7 kinase inactivation in splenic and peritoneal macrophages. We measured the basal phagocytic activity of splenic macrophages using fluorescent latex beads, pHrodo zymosan bioparticles and opsonized red blood cells. KD macrophages phagocytized more efficiently and had slightly higher baseline calcium levels compared to WT cells. We found no obvious differences in store-operated Ca2+ entry between WT and KD macrophages. By contrast, the resting cytosolic pH in KD macrophages was significantly more alkaline than in WT. Pharmacological blockade of sodium-hydrogen exchanger 1 (NHE1) reversed the cytosolic alkalinization and reduced phagocytosis in KD macrophages. Basal TRPM7 channel activity in KD macrophages was also reduced after NHE1 blockade. Cytosolic Mg2+ sensitivity of TRPM7 channels measured in peritoneal macrophages was similar in WT and KD mice. The higher basal TRPM7 channel activity in KD macrophages is likely due to alkalinization. Our results identify a novel role for TRPM7 kinase as a suppressor of basal phagocytosis and a regulator of cellular pH.
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影响因子：
3.5
作者：
Clark, Kristopher;Middelbeek, Jeroen;van Leeuwen, Frank N.
通讯作者：
van Leeuwen, Frank N.
影响因子：
4.4
作者：
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影响因子：
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影响因子：
2.9
作者：
Dorovkov MV;Kostyukova AS;Ryazanov AG
通讯作者：
Ryazanov AG
影响因子：
4.8
作者：
Bird, Gary S.;DeHaven, Wayne I.;Smyth, Jeremy T.;Putney, James W., Jr.
通讯作者：
Putney, James W., Jr.