Chemical genetics technology regulates the activity of GLP-1 neurons and its effect on appetite / 中华内分泌代谢杂志

ABSTRACT

Objective:To conduct a glucagon like peptide-1(GLP-1)controllability model rat by chemical genetics, and observe the impact of GLP-1 neuron excitability on appetite.Methods:Fifteen rats were evenly divided into Green fluorescent protein(GFP)group, HM3D group, and HM4D group. Various combinations of adeno-associated virus(rAAV)were injected into the nucleus tractus solitarius(NTS). rAAV-GLP-1-cre and rAAV-GFP-dio were administered in rats of GFP group. The rats of HM3D group were injected with rAAV-GLP-1-cre and rAAV-HM3D-mCherry-dio while rAAV-GLP-1-cre and rAAV-HM4D-mCherry-dio were injected in rats of HM4D group . The optimal dose of clozapine N-oxide(CNO)was selected based on feeding behavior and body weight changes of rats after intraperitoneal injection of different doses of CNO. The controllability of GLP-1 neurons was confirmed by comparing with intraperitoneal injection of saline. The number of activated GLP-1 neurons in the NTS area and the expression of POMC neurons in the hypothalamus were detected 30 minutes after CNO injection.Results:GLP-1 neurons in the NTS area of rats were successfully labeled. The rat of HM3D group revealed a decrease in food intake( P=0.021)while the rat of HM4D group showed an increase( P=0.002), when given 1 mg/kg of CNO, no changes at the dose of 0.5 mg/kg and 3.0 mg/kg. Immunofluorescence showed that the activity of GLP-1 neurons in NTS of GFP group was lower than that of HM3D group( P=0.022), and higher compared with that of the HM4D group( P=0.049). The expression of GLP-1 neurons in NTS and POMC neurons in the hypothalamus of the HM3D group after intraperitoneal injection of CNO was also higher than that in the HM4D group( P=0.003). Conclusion:Using chemical genetics technology, GLP-1 controllability model rat could be successfully established via injecting varying combinations of rAAV into the NTS area of rat. Injection of 1 mg/kg CNO can effectively activate or inhibit the neuron to regulate appetite.