Govindasamy Navishaa, Chung Chok Kian, Ying Ng Pei, Yian Koh Rhun, Moi Chye Soi
School of Medicine, International Medical University, 57000 Kuala Lumpur, Malaysia.
School of Health Science, International Medical University, 57000 Kuala Lumpur, Malaysia.
Rep Biochem Mol Biol. 2022 Apr;11(1):63-73. doi: 10.52547/rbmb.11.1.63.
Peripheral nerve injury (PNI) is a common condition that compromises motor and sensory functions. Peripheral nerves are known to have regenerative capability and the pineal hormone, melatonin, is known to aid nerve regeneration. However, the role of Schwann cells and the pathways involved remain unclear. Thus, the aim of this study is to identify the effects of melatonin on Schwann cell proliferation, dedifferentiation, and the involvement of nuclear factor kappa light chain enhancer of activated B cells (NF-ĸB), focal adhesion kinase (FAK) and proto-oncogene tyrosine-protein kinase, Src pathways in this process.
Schwann cells was treated with melatonin and its proliferation and dedifferentiation were identified using MTT assay and immunofluorescence staining for SRY (sex determining region Y)-box 2 (SOX2). Next, the protein expressions of NF-ĸB, FAK and Src pathways were identified by Western blot.
MTT results confirmed increased proliferation of Schwann cells with melatonin treatment, and it was highest at 10 μM melatonin. Immunofluorescent staining revealed an increase in the green fluorescence staining for SOX2 in melatonin-treated cells, showing enhanced dedifferentiation. Western blot assay revealed melatonin increased phospho-NF-ĸB (PNF-ĸB), IKK-α, FAK (D2R2E), phospho-FAK (Tyr 576/577 and Tyr 397) protein expressions as compared with control. However, Src (32G6), Lyn (C13F9), Fyn, Csk (C74C1) protein expressions were not increased as compared with control.
Melatonin promotes Schwann cell proliferation and dedifferentiation via NF-ĸB, FAK-dependent but Src-independent pathways.
周围神经损伤（PNI）是一种常见病症，会损害运动和感觉功能。已知周围神经具有再生能力，松果体激素褪黑素有助于神经再生。然而，雪旺细胞的作用及相关途径仍不清楚。因此，本研究的目的是确定褪黑素对雪旺细胞增殖、去分化的影响，以及在此过程中核因子κB轻链增强子（NF-κB）、粘着斑激酶（FAK）和原癌基因酪氨酸蛋白激酶Src途径的参与情况。
用褪黑素处理雪旺细胞，使用MTT法和针对性别决定区Y框蛋白2（SOX2）的免疫荧光染色鉴定其增殖和去分化情况。接下来，通过蛋白质印迹法鉴定NF-κB、FAK和Src途径的蛋白表达。
MTT结果证实，褪黑素处理可增加雪旺细胞的增殖，在10μM褪黑素时增殖最高。免疫荧光染色显示，褪黑素处理的细胞中SOX2的绿色荧光染色增加，表明去分化增强。蛋白质印迹分析显示，与对照组相比，褪黑素增加了磷酸化NF-κB（pNF-κB）、IKK-α、FAK（D2R2E）、磷酸化FAK（Tyr 576/577和Tyr 397）的蛋白表达。然而，与对照组相比，Src（32G6）、Lyn（C13F9）、Fyn、Csk（C74C1）的蛋白表达并未增加。
褪黑素通过NF-κB、FAK依赖但Src非依赖的途径促进雪旺细胞增殖和去分化。
