To investigate the protective effect of folic acid on the epithelial-mesenchymal transition (EMT) induced by N-methyl-N ’-nitro-n-nitroguanidine (MNNG) and its signaling mechanism.
SD rats were randomly divided into blank group, model group, low-dose, medium-dose and high-dose folate groups (1.25, 2.5, 5 mg/kg), control group was given 10 mL/kg normal saline, and other groups were given 25 mg/kg MNNG.All were administered with free drinking water once a day for 12 weeks. After 12 weeks, the expression of E-cadherin and N-cadherin protein was observed by immunohistochemistry. The expressions of E-cadherin, ZO-1, N-cadherin and Vimentin were detected by Western blot. In vitro (0.1, 0.2, 0.4 μg/mL), the concentration of folic acid was treated with 20 μmol/L MNNG for 24 h, and the mRNA transcription levels of E-cadherin, ZO-1, N-cadherin, Vimentin, TGF-β, Wnt/β-catenin, JAK/STAT 3 signaling pathways were detected by RT-qPCR. The expressions of E-cadherin, ZO-1, N-cadherin and Vimentin were detected by Western blot.
Compared with the model group, folic acid could improve the precancerous lesions caused by MNNG, up-regulate the expression of E-cadherin (F=90.3,P<0.001) and ZO-1 protein (F=188.9,P<0.001), and down-regulate the expression of N-cadherin (F=68.9,P<0.001) and Vimentin protein (F=82.6,P<0.001). The results of cell Western blot showed that compared with the control group, the expression levels of E-cadherin and ZO-1 were decreased, decreasing to 63.7% (95%CI: 0.589-0.675, P<0.001) and 57.1% (95%CI: 0.494-0.706, P<0.001) of the control group. Cell RT-qPCR results showed that compared with the model group, E-cadherin mRNA levels were increased (F=8.5, P=0.007), the expression of ZO-1 mRNA increased (F=31.5, P<0001), N-cadherin mRNA levels were decreased (F=34.1, P<0.001), and the expression of Vimentin mRNA decreased (F=17.8, P<0.001).Cell RT-qPCR confirmed that MNNG can promote the transcription of key mRNA in TGF-β signaling pathway, Wnt/β-Catenin signaling pathway, and JAK/STAT 3 signaling pathway. The downstream transcription factors snail and ZEB1 mRNA transcription were activated, while folic acid could antagonize the process.
Folic acid has certain protective ability against MNNG induced esophageal epithelial-mesenchymal transformation, which may be related to inhibiting the activation of JAK/ STAT3 signaling pathway.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |