Immunology and Microbiology Department, Dasman Diabetes Institute, Kuwait City, Kuwait.
Bioenergetic Department, Dasman Diabetes Institute, 15462, Dasman, Kuwait.
Sci Rep. 2023 Sep 1;13(1):14351. doi: 10.1038/s41598-023-41514-6.
Studies have established the association between increased plasma levels of matrix metalloproteinase (MMP)-9 and adipose tissue inflammation. Tumor necrosis factor α (TNFα) was elevated in obesity and is involved in the induction of MMP-9 in monocytic cells. However, the underlying molecular mechanism was incompletely understood. As per our recent report, TNFα mediates inflammatory responses through long-chain acyl-CoA synthetase 1 (ACSL1). Therefore, we further investigated the role of ACSL1 in TNFα-mediated MMP-9 secretion in monocytic cells. THP-1 cells and primary monocytes were used to study MMP-9 expression. mRNA and protein levels of MMP-9 were determined by qRT-PCR and ELISA, respectively. Signaling pathways were studied using Western blotting, inhibitors, and NF-kB/AP1 reporter cells. We found that THP-1 cells and primary human monocytes displayed increased MMP-9 mRNA expression and protein secretion after incubation with TNFα. ACSL1 inhibition using triacsin C significantly reduced the expression of MMP-9 in the THP-1 cells. However, the inhibition of β-oxidation and ceramide biosynthesis did not affect the TNFα-induced MMP-9 production. Using small interfering RNA-mediated ACSL1 knockdown, we further confirmed that TNFα-induced MMP-9 expression/secretion was significantly reduced in ACSL1-deficient cells. TNFα-mediated MMP-9 expression was also significantly reduced by the inhibition of ERK1/ERK2, JNK, and NF-kB. We further observed that TNFα induced phosphorylation of SAPK/JNK (p54/46), ERK1/2 (p44/42 MAPK), and NF-kB p65. ACSL1 inhibition reduced the TNFα-mediated phosphorylation of SAPK/JNK, c-Jun, ERK1/2, and NF-kB. In addition, increased NF-κB/AP-1 activity was inhibited in triacsin C treated cells. Altogether, our findings suggest that ACSL1/JNK/ERK/NF-kB axis plays an important role in the regulation of MMP-9 induced by TNFα in monocytic THP-1 cells.
研究已经证实，基质金属蛋白酶（MMP）-9 血浆水平升高与脂肪组织炎症有关。肿瘤坏死因子 α（TNFα）在肥胖症中升高，并参与单核细胞中 MMP-9 的诱导。然而，其潜在的分子机制尚不完全清楚。根据我们最近的报告，TNFα 通过长链酰基辅酶 A 合成酶 1（ACSL1）介导炎症反应。因此，我们进一步研究了 ACSL1 在 TNFα 介导的单核细胞 MMP-9 分泌中的作用。THP-1 细胞和原代单核细胞用于研究 MMP-9 的表达。通过 qRT-PCR 和 ELISA 分别测定 MMP-9 的 mRNA 和蛋白水平。使用 Western blot、抑制剂和 NF-kB/AP1 报告细胞研究信号通路。我们发现，与 TNFα 孵育后，THP-1 细胞和原代人单核细胞的 MMP-9 mRNA 表达和蛋白分泌增加。使用三乙酰精氨酸 C 抑制 ACSL1 显著降低了 THP-1 细胞中 MMP-9 的表达。然而，β-氧化和神经酰胺生物合成的抑制并不影响 TNFα 诱导的 MMP-9 产生。使用小干扰 RNA 介导的 ACSL1 敲低，我们进一步证实，ACSL1 缺陷细胞中 TNFα 诱导的 MMP-9 表达/分泌显著减少。TNFα 介导的 MMP-9 表达也被 ERK1/ERK2、JNK 和 NF-kB 的抑制显著降低。我们还观察到，TNFα 诱导 SAPK/JNK（p54/46）、ERK1/2（p44/42 MAPK）和 NF-kB p65 的磷酸化。ACSL1 抑制减少了 TNFα 介导的 SAPK/JNK、c-Jun、ERK1/2 和 NF-kB 的磷酸化。此外，三乙酰精氨酸 C 处理的细胞中 NF-κB/AP-1 活性增加受到抑制。总之，我们的研究结果表明，ACSL1/JNK/ERK/NF-kB 轴在 TNFα 诱导的单核细胞 THP-1 细胞中 MMP-9 的调节中发挥重要作用。
