EXPRESSION/REGULATION OF PHOSPHODIESTERASE 3 ISOFORMS

磷酸二酯酶 3 异构体的表达/调节

• 批准号: 6290429
• 负责人: VINCENT MANGANIELLO
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6290429
• 关键词: 3'5' cyclic nucleotide phosphodiesterase; B lymphocyte; T lymphocyte; cell differentiation; cell type; enzyme activity; esterase inhibitor; gene targeting; in situ hybridization; inflammation; isozymes; laboratory mouse; laboratory rat; leukocyte activation /transformation; macrophage; natural killer cells; northern blottings; protein isoforms; transfection

By catalyzing hydrolysis of cAMP and cGMP, cyclic nucleotide phosphodiesterases (PDEs) are critical regulators of intracellular concentrations of, and biological responses mediated by, cyclic nucleotides, including immune/inflammatory responses. Understanding cellular regulation of PDE isoforms [which belong to ten gene families (PDE1-10)] will be of increasing importance for targeting specific PDEs in treating pulmonary disorders. Although individual cells usually contain representatives of several PDE gene families, little is known of signalling pathways involved in cytokine and growth factor regulation of different PDEs in a single cell. In murine FDCP2 promyeloid cells, IL-4 and IGF-1 activate PDE3 and PDE4, whereas IL-3 activates only PDE4. Studies with TNFalpha and inhibitors of JAK, PI3- K, PKC, and MAPK kinases indicate that both IGF-1 and IL-3 activate PDE3 and PDE4 via PI3-K-dependent signals. Downstream of PI3-K, regulatory pathways diverge; PDE4, but not PDE3, is activated by MEK/MAPK-dependent signals. FDCP2 cells were, therefore, permanently transfected with wild type (wt), constitutively active (CA), or kinase inactive (KI) forms of MEK and PKB. Studies with these transfected cells indicated that PDE4 was activated by MEK/MAPK-dependent signals, and that PDE3 was phosphorylated and activated by PKB-dependent signals. Recombinant mouse (M) PDE3B was phosphorylated and activated in vitro by PKB; a truncated MPDE3B mutant lacking consensus PKB phosphorylation sites was not phosphorylated/activated. In cells expressing WT PKB, the proapoptotic protein BAD was phosphorylated in response to IGF-1; phosphorylation was blocked by 8-Br-cAMP or the PDE3 inhibitor cilostamide. These and other data suggest that PDE3B is a downstream target, if not substrate, of PKB and may function as an effector of PKB in regulation of cAMP pools that modulate, at least in part, effects of PKB on survival/proliferation of FDCP2 cells. - PDE3, PDE4, cyclic nucleotide hydrolysis, insulin, IGF-1, Protein Kinase B, FDCP2 hematopoietic cells, cell survival/proliferation

通过催化 cAMP 和 cGMP 的水解，环核苷酸磷酸二酯酶 (PDE) 是环核苷酸细胞内浓度和环核苷酸介导的生物反应（包括免疫/炎症反应）的关键调节剂。了解 PDE 同工型（属于 10 个基因家族 (PDE1-10)）的细胞调节对于针对特定 PDE 治疗肺部疾病将变得越来越重要。尽管单个细胞通常含有多个 PDE 基因家族的代表，但人们对单个细胞中不同 PDE 的细胞因子和生长因子调节所涉及的信号通路知之甚少。在小鼠 FDCP2 早幼粒细胞中，IL-4 和 IGF-1 激活 PDE3 和 PDE4，而 IL-3 仅激活 PDE4。对 TNFα 以及 JAK、PI3-K、PKC 和 MAPK 激酶抑制剂的研究表明，IGF-1 和 IL-3 均通过 PI3-K 依赖性信号激活 PDE3 和 PDE4。 PI3-K 下游的监管途径存在差异； PDE4（而非 PDE3）被 MEK/MAPK 依赖性信号激活。因此，FDCP2 细胞永久转染野生型 (wt)、组成型活性 (CA) 或激酶失活 (KI) 形式的 MEK 和 PKB。对这些转染细胞的研究表明，PDE4 被 MEK/MAPK 依赖性信号激活，PDE3 被磷酸化并被 PKB 依赖性信号激活。重组小鼠（M）PDE3B在体外被PKB磷酸化并激活；缺乏共有 PKB 磷酸化位点的截短 MPDE3B 突变体未被磷酸化/激活。在表达 WT PKB 的细胞中，促凋亡蛋白 BAD 在 IGF-1 的作用下被磷酸化；磷酸化被 8-Br-cAMP 或 PDE3 抑制剂西洛酰胺阻断。这些和其他数据表明，PDE3B 即使不是底物，也是 PKB 的下游靶标，并且可能在 cAMP 池的调节中充当 PKB 的效应子，从而至少部分调节 PKB 对 FDCP2 细胞存活/增殖的影响。 - PDE3、PDE4、环核苷酸水解、胰岛素、IGF-1、蛋白激酶 B、FDCP2 造血细胞、细胞存活/增殖