Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, India.
Orthopedic Surgery, King Georges Medical University, Lucknow, India.
J Leukoc Biol. 2019 Aug;106(2):397-412. doi: 10.1002/JLB.1A0918-349RR. Epub 2019 Mar 12.
Neutrophils play important role in immunity and inflammation through diverse mechanisms. Reports from this lab and others have demonstrated involvement of NO in neutrophil adhesion, chemotaxis, bacterial killing, reactive oxygen species generation, neutrophil extracellular traps' formation, and apoptosis. Constitutive expression of iNOS in human neutrophils has also been documented. The role of NO-iNOS in neutrophil differentiation however remains ill-defined. The present study was undertaken to understand the role of NO generated from iNOS in the neutrophil differentiation by using iNOS-overexpressing K562 cells (K562 ) and iNOS-deficient murine progenitor cells (lineage negative cells; lin ). We observed that iNOS overexpression led to increased neutrophilic differentiation in K562 cells; more specifically an early and accelerated neutrophilic differentiation was spotted in K562 . These observations were further validated using iNOS knockout lin cells or hematopoietic progenitor cells that exhibited delayed neutrophil differentiation in comparison to its wild-type counterpart. In addition, a significant increase in the gene expression of iNOS during neutrophilic differentiation of CD34 hematopoietic stem and progenitor cells derived from human bone marrow further substantiates importance of iNOS in neutrophil differentiation. Moreover, a significant increase in NO generation during neutrophil differentiation was observed and enhanced neutrophil differentiation with NO donor was also observed, implying the importance of NO in neutrophil differentiation. Collectively, using alternative approaches, we demonstrated that neutrophil differentiation is significantly influenced by iNOS or NO, suggesting the possibility of exploiting this novel link for therapeutic aspects of NO generated from iNOS and neutrophil differentiation in hematopoiesis-related disorders.
中性粒细胞通过多种机制在免疫和炎症中发挥重要作用。本实验室和其他实验室的报告表明，NO 参与中性粒细胞黏附、趋化、杀菌、活性氧生成、中性粒细胞细胞外陷阱形成和细胞凋亡。还已经证明人中性粒细胞中诱导型一氧化氮合酶 (iNOS) 的组成型表达。然而，NO-iNOS 在中性粒细胞分化中的作用仍未明确。本研究旨在通过使用 iNOS 过表达 K562 细胞 (K562) 和 iNOS 缺陷型鼠祖细胞 (谱系阴性细胞；lin) 来理解 iNOS 产生的 NO 在中性粒细胞分化中的作用。我们观察到 iNOS 过表达导致 K562 细胞中中性粒细胞分化增加；更具体地说，在 K562 中观察到早期和加速的中性粒细胞分化。这些观察结果通过使用 iNOS 敲除 lin 细胞或造血祖细胞进一步验证，与野生型相比，这些细胞的中性粒细胞分化延迟。此外，来自人骨髓的 CD34 造血干祖细胞在中性粒细胞分化过程中 iNOS 的基因表达显著增加，进一步证实了 iNOS 在中性粒细胞分化中的重要性。此外，在中性粒细胞分化过程中观察到 NO 生成显著增加，并观察到 NO 供体增强中性粒细胞分化，这表明 NO 在中性粒细胞分化中的重要性。总之，我们使用替代方法证明中性粒细胞分化受 iNOS 或 NO 的显著影响，这表明有可能利用这种新的联系，针对造血相关疾病中 iNOS 产生的 NO 和中性粒细胞分化的治疗方面。
