Unidad Asociada de Inmunología, Instituto de Química Biológica (IQB), Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo 11400, Uruguay; Area Inmunología, Departamento de Biociencias (DEPBIO), Facultad de Química, Universidad de la República, General Flores 2124, Montevideo 11800, Uruguay; Laboratorio de Inmunología, Instituto de Higiene "Prof. Arnoldo Berta", Universidad de la República, Alfredo Navarro 3051, Montevideo 11600, Uruguay.
Unidad Asociada de Inmunología, Instituto de Química Biológica (IQB), Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo 11400, Uruguay; Area Inmunología, Departamento de Biociencias (DEPBIO), Facultad de Química, Universidad de la República, General Flores 2124, Montevideo 11800, Uruguay; Laboratorio de Inmunología, Instituto de Higiene "Prof. Arnoldo Berta", Universidad de la República, Alfredo Navarro 3051, Montevideo 11600, Uruguay.
Immunobiology. 2023 Nov;228(6):152752. doi: 10.1016/j.imbio.2023.152752. Epub 2023 Oct 2.
Tissue transglutaminase (TG2) expressed in monocytes and macrophage is known to participate in processes during either early and resolution stages of inflammation. The alternative splicing of tissue transglutaminase gene is a mechanism that increases its functional diversity. Four spliced variants are known with truncated C-terminal domains (TGM2_v2, TGM2_v3, TGM2_v4a, TGM2_v4b) but scarce information is available about its expression in human monocyte and macrophages. We studied the expression of canonical TG2 (TGM2_v1) and its short spliced variants by RT-PCR during differentiation of TPH-1 derived macrophages (dTHP-1) using two protocols (condition I and II) that differ in Phorbol-12-myristate-13-acetate dose and time schedule. The production of TNF-α and IL-1β in supernatant of dTHP-1, measured by ELISA in supernatants showed higher proinflammatory milieu in condition I. We found that the expression of all mRNA TG2 spliced variants were up-regulated during macrophage differentiation and after IFN-γ treatment of dTHP-1 cells in both conditions. Nevertheless, the relative fold increase or TGM2_v3 in relation with TGM2_v1 was higher only with the condition I. M1/M2-like THP-1 macrophages obtained with IFN-γ/IL-4 treatments showed that the up-regulation of TGM2_v1 induced by IL-4 was higher in relation with any short spliced variants. The qualitative profile of relative contribution of spliced variants in M1/M2-like THP-1 cells showed a trend to higher expression of TGM2_v3 in the inflammatory functional phenotype. Our results contribute to the knowledge about TG2 spliced variants in the biology of monocyte/macrophage cells and show how the differentiation conditions can alter their expression and cell function.
组织转谷氨酰胺酶 (TG2) 在单核细胞和巨噬细胞中表达，已知参与炎症的早期和解决阶段的过程。组织转谷氨酰胺酶基因的选择性剪接是增加其功能多样性的一种机制。已知有四个截短的 C 末端结构域的剪接变体 (TGM2_v2、TGM2_v3、TGM2_v4a、TGM2_v4b)，但关于其在人单核细胞和巨噬细胞中的表达信息很少。我们通过 RT-PCR 研究了两种方案 (方案 I 和 II) 中 TPH-1 衍生的巨噬细胞 (dTHP-1) 分化过程中经典 TG2 (TGM2_v1) 和其短剪接变体的表达，这两种方案在佛波醇-12-肉豆蔻酸-13-乙酸酯剂量和时间安排上有所不同。通过 ELISA 在上清液中测量上清液中 dTHP-1 产生的 TNF-α 和 IL-1β，结果显示方案 I 中具有更高的前炎症环境。我们发现，在两种条件下，所有 mRNA TG2 剪接变体的表达在巨噬细胞分化过程中以及 IFN-γ 处理 dTHP-1 细胞后均上调。然而，仅在方案 I 中，TGM2_v3 与 TGM2_v1 的相对倍数增加或 TGM2_v3 与 TGM2_v1 的相对倍数增加更高。用 IFN-γ/IL-4 处理获得的 M1/M2 样 THP-1 巨噬细胞显示，IL-4 诱导的 TGM2_v1 上调与任何短剪接变体相比更高。M1/M2 样 THP-1 细胞中剪接变体相对贡献的定性特征显示出在炎症功能表型中 TGM2_v3 表达较高的趋势。我们的研究结果有助于了解单核细胞/巨噬细胞中 TG2 剪接变体的生物学特性，并展示分化条件如何改变其表达和细胞功能。
