Chicken gga-miR-19a Targets ZMYND11 and Plays an Important Role in Host Defense against Mycoplasma gallisepticum (HS Strain) Infection.

Qingchang Hu,Yue Hou,Jianjun Sun,Dingren Bi,Zaiwei Wang,Xiuli Peng,Yabo Zhao

doi:10.3389/fcimb.2016.00102

Abstract

Mycoplasma gallisepticum (MG), one of the most pathogenic Mycoplasmas, can cause chronic respiratory disease (CRD) in chickens. It has been suggested that micro-ribonucleic acids (miRNAs) are involved in microbial pathogenesis. However, little is known about the roles of miRNAs in MG infection. Previously, we found by deep sequencing that gga-miR-19a was significantly up-regulated in the lungs of MG-infected chicken embryos. In this work, we confirmed that gga-miR-19a was up-regulated in both MG-infected chicken embryonic lungs and MG-infected DF-1 (chicken embryo fibroblast) cells. At 72 h post-transfection, we found that the over-expression of gga-miR-19a significantly enhanced the proliferation of MG-infected DF-1 cells by promoting the transition from the G1 phase to the S and G2 phases, while a gga-miR-19a inhibitor repressed the proliferation of MG-infected DF-1 cells by arresting the cell cycle in the G1 phase. Moreover, we found that gga-miR-19a regulated the expression of the host zinc-finger protein, MYND-type containing 11 (ZMYND11), through binding to its 3′ untranslated region (3′-UTR). DAVID analysis revealed that ZMYND11 could negatively regulate the NF-kappaB (NF-κB) signaling pathway in chickens (Gallus gallus). Upon MG infection, gga-miR-19a, NF-κB, MyD88, and TNF-α were all up-regulated, whereas ZMYND11 was down-regulated. The over-expression of gga-miR-19a in the DF-1 cells did not affect the above gene expression patterns, and gga-miR-19a inhibitor repressed the expression of NF-κB, MyD88, and TNF-α, but enhanced the expression of ZMYND11. In conclusion, gga-miR-19a might suppress the expression of ZMYND11 in MG-infected chicken embryonic lungs and DF-1 cells, activate the NF-κB signaling pathway, and promote pro-inflammatory cytokines expression, the cell cycle progression and cell proliferation to defend against MG infection.

Highlights

Mycoplasma, an important prokaryote, can infect humans, wildlife, and a wide range of economically important livestock species (Gambarini et al, 2009; Osman et al, 2009; Nicholas and Ayling, 2016)
Using micro-ribonucleic acids (miRNAs) deep sequencing, we previously found that gga-miR-19a was up-regulated in infected chicken embryonic lung tissues
It is well documented that miRNAs are critical regulators of gene silencing that exert their function through suppressing translation or/and promoting degradation of targeted mRNAs

Summary

Introduction

Mycoplasma, an important prokaryote, can infect humans, wildlife, and a wide range of economically important livestock species (Gambarini et al, 2009; Osman et al, 2009; Nicholas and Ayling, 2016). One of the most important Mycoplasma species, Mycoplasma gallisepticum (MG) is the causative pathogen of avian chronic respiratory disease (CRD) (Ley, 2003), which is invasive and causes severe inflammation in the tracheas and lungs of chickens and turkeys around the world (Davidson et al, 1982; Yoder, 1991; Stipkovits et al, 2012). MG is very difficult to be eliminated from chicken farms. Vaccination and antibiotics can be used to control the infection, it is impossible to completely clear MG from infected chickens. Mycoplasmosis is causing huge economic losses to the poultry industry worldwide (Pennycott et al, 2005)

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