Ni Min, Zhang Hua, Li Fan Chi, Wang Bin Bin, Xu Kai Zun, Shen Wei De, Li Bing
School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China.
School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, Jiangsu 215123, PR China.
Peptides. 2015 Jun;68:64-71. doi: 10.1016/j.peptides.2014.12.014. Epub 2015 Jan 27.
Bombyx mori orphan G protein-coupled receptor, BNGR-A4, is the specific receptor of B. mori neuropeptide F (BmNPFR, neuropeptide F designated NPF). BmNPFR binds specifically and efficiently to B. mori neuropeptides BmNPF1a and BmNPF1b, which activates the ERK1/2 signaling pathway to regulate B. mori food intake and growth. Titanium dioxide nanoparticles (TiO2 NPs) can promote B. mori growth. However, whether the mechanisms of TiO2 NPs' effects are correlated with BmNPFR remains unknown. In this study, the effects of TiO2 NPs (5mg/L) feeding and BmNPFR-dsRNA injection on B. mori food intake and growth were investigated; after TiO2 NPs treatments, B. mori food intake, body weight, and cocoon shell weight were 5.82%, 4.64%, and 9.30% higher, respectively, than those of controls. The food intake, body weight, and cocoon shell weight of the BmNPFR-dsRNA injection group were reduced by 8.05%, 6.28%, and 6.98%, respectively, compared to the control. After TiO2 NPs treatment for 72h, the transcriptional levels of BmNPFR, BmNPF1a, and BmNPF1b in the midgut were 1.58, 1.43, and 1.34-folds, respectively, of those of the control, but 1.99, 2.26, and 2.19-folds, respectively, of the BmNPFR-dsRNA injection group; the phosphorylation level of MAPK was 24.03% higher than the control, while the phosphorylation level of BmNPFR-dsRNA injection group was 71.00% of control. The results indicated that TiO2 NPs affect B. mori feeding and growth through increasing the expression of BmNPFR. This study helps clarify the roles of BmNPF/BmNPFR system in TiO2 NPs' effects on B. mori feeding, growth, and development.
家蚕孤儿G蛋白偶联受体BNGR-A4是家蚕神经肽F（BmNPFR，神经肽F命名为NPF）的特异性受体。BmNPFR能特异性且高效地结合家蚕神经肽BmNPF1a和BmNPF1b，从而激活ERK1/2信号通路来调节家蚕的食物摄取和生长。二氧化钛纳米颗粒（TiO2 NPs）能够促进家蚕生长。然而，TiO2 NPs作用机制是否与BmNPFR相关仍不清楚。在本研究中，探究了TiO2 NPs（5mg/L）添食和注射BmNPFR-dsRNA对家蚕食物摄取和生长的影响；TiO2 NPs处理后，家蚕的食物摄取量、体重和茧层重量分别比对照组高5.82%、4.64%和9.30%。与对照组相比，注射BmNPFR-dsRNA组的食物摄取量、体重和茧层重量分别降低了8.05%、6.28%和6.98%。TiO2 NPs处理72小时后，中肠中BmNPFR、BmNPF1a和BmNPF1b的转录水平分别是对照组的1.58倍、1.43倍和1.34倍，但分别是注射BmNPFR-dsRNA组的1.99倍、2.26倍和2.19倍；MAPK的磷酸化水平比对照组高24.03%，而注射BmNPFR-dsRNA组的磷酸化水平是对照组的71.00%。结果表明，TiO2 NPs通过增加BmNPFR的表达来影响家蚕的摄食和生长。本研究有助于阐明BmNPF/BmNPFR系统在TiO2 NPs对家蚕摄食、生长和发育影响中的作用。
