[Antagonistic effect of Lactobacillus reuteri on testicular reproductive toxicity of neonicotinoid insecticides in mice].

Abstract

Objective: To explore the effect of Lactobacillus reuteri on testicular injury in mice exposed to neonicotinoid insecticides (NNI).

Methods: Fifteen C57BL/6 male mice were randomly divided into control group (CTRL group), exposure group (NNI group) and Lactobacillus intervention group (NNI-L group). The mice in CTRL group were given 0.02ml/g of 0.5% carboxymethyl cellulose sodium solution by gavage for 14 days. The mice in NNI group were given 0.02 ml/g of NNI mixture by gavage for 14 days. The mice in NNI-L group were given 0.02 ml/g of NNI mixture by gavage and 5×108cfu/ml of Lactobacillus reuteri powder solution for 14 days. Then, the histomorphology and function of testicle were evaluated by hematoxylin-eosin staining, immunofluorescence staining and RNA sequencing.

Results: Compared with CTRL group, the thickness of testicular seminiferous epithelium in the NNI group was significantly thinner. And the decline in the number of spermatogenic cells and sperm was observed. And the expression of spermatogonial stem cell marker UCHL1 was down-regulated which was significantly improved in NNI-L group compared with the NNI group. The abnormal expressions of hormone and sperm methylation related genes in testis of NNI group were detected by RNA sequencing, with significant down-regulation being found in NPFF and IGF2. While the expression of HSD3B8 was significantly up-regulated. The abnormal expression of these genes could be significantly improved after oral administration of Lactobacillus reuteri.

Conclusion: Testicular spermatogenesis and endocrine function can be damaged by NNI exposure. And oral administration of Lactobacillus reuteri protects testis from the adverse effects of NNI toxicity.