Reproductive toxicity of enrofloxacin in Caenorhabditis elegans involves oxidative stress-induced cell apoptosis.

Fluoroquinolone antibiotics (FQs) that persist and bioaccumulate in the environment have aroused people's great concern. Here, we studied the adverse effects of FQs in soil animals of Caenorhabditis elegans via food-chronically exposure. The result shows C. elegans exposed to FQs exhibited reproductive toxicity with small-brood size and low-egg hatchability. To study the underlying mechanism, we conduct a deep investigation of enrofloxacin (ENR), one of the most frequently detected FQs, on nematodes which is one of commonly used animal indicator of soil sustainability. The concentration-effect curves simulated by the Hill model showed that the half effect concentrations (EC50) of ENR were (494.3 ± 272.9) µmol/kg and (107.4 ± 30.9) µmol/kg for the brood size and the hatchability, respectively. Differential gene expression between the control and the ENR-exposure group enriched with the oxidative stress and cell apoptosis pathways. The results together with the enzyme activity in oxidative stress and the cell corpses suggested that ENR-induced reproductive toxicity was related to germ cell apoptosis under oxidative stress. The risk quotients of some soil and livestock samples were calculated based on the threshold value of EC10 for the egg hatchability (2.65 µmol/kg). The results indicated that there was possible reproductive toxicity on the nematodes in certain agricultural soils for the FQs. This study suggested that chronic exposure to FQs at certain levels in environment would induce reproductive toxicity to the nematodes and might reduce the soil sustainability, alarming the environment risks of antibiotics abuse.

[Construction of recombinant gene adenovirus encoding enhanced green fluorecence protein-peroxisome proliferator-activated receptor gamma2 fusion protein and its expression in bone marrow mesenchymal stem cells].

OBJECTIVE: To construct mouse enhanced green fluorecence protein (EGFP) -peroxisome proliferator-activated receptor (PPAR)gamma2, and to detect EGFP-PPARgamma2 expression in infected mouse bone marrow mesenchymal stem cells (BMSC). METHODS: Cut the fragment of PPARgamma2 from the expression plasmid pcDNA flag PPARgamma2, then cloned the gene fragment into pEGFP-C1 and pEGFP-N1 vector. Subsequently, subclone the fragment EGFP-PPARgamma2 from pEGFP-C1-PPARgamma2 into the shuttle plasmid DC315. HEK293 cells were co-transfected with the constructed recombinant shuttle plasmid DC315-EGFP-PPARgamma2 and large adenovirus helper plasmid pBHGlox deltaE1, 3Cre in mediation of liposome. The obtained replication-defective recombinant adenovirus Ad-EGFP-PPARgamma2 was confirmed. Then it was propagated in HEK293 cells. After the BMSC were transfected for 72 h, adipogenic differentiation was demonstrated. RESULTS: HEK293 cells were transfected with the pEGFP-C1-PPARgamma2 or pEGFP-N1-PPARgamma2 in mediation of liposome. The former green fluorescence protein was better than the latter by fluorescence microscope. The recombinant plasmids were digested and identified. Western blot analysis showed the expression of EGFP-PPARgamma2 in vitro. EGFP-PPARgamma2 protein was detectable in the nucleus of BMSC. CONCLUSION: The recombinant adenovirus encoding EGFP-PPARgamma2 fusion protein was successfully constructed, which provided a basis for application of EGFP-PPARgamma2 gene to adenovirus-mediated gene therapy.