Mycoplasma genitalium Protein of Adhesion Promotes the Early Proliferation of Human Urothelial Cells by Interacting with RPL35.

Pei Dai,Xiangying Deng,Dan Luo,Yating Liao,Lingling Li,Peng Liu,Yanhua Zeng

doi:10.3390/pathogens10111449

Abstract

Mycoplasma genitalium is a newly recognized pathogen associated with sexually transmitted diseases (STDs). MgPa, the adhesion protein of Mycoplasma genitalium, is the main adhesin and the key factor for M. genitalium interacting with host cells. Currently, the long-term survival mechanism of M. genitalium in the host is not clear. In this study, a T7 phage-displayed human urothelial cell (SV-HUC-1) cDNA library was constructed, and the interaction of MgPa was screened from this library using the recombinant MgPa (rMgPa) as a target molecule. We verified that 60S ribosomal protein L35 (RPL35) can interact with MgPa using far-Western blot and co-localization analysis. According to the results of tandem mass tag (TMT) labeling and proteome quantitative analysis, there were altogether 407 differentially expressed proteins between the pcDNA3.1(+)/MgPa-transfected cells and non-transfected cells, of which there were 6 downregulated proteins and 401 upregulated proteins. The results of qRT-PCR demonstrated that interaction between rMgPa and RPL35 could promote the expressions of EIF2, SRP68, SERBP1, RPL35A, EGF, and TGF-β. 3-(4,5)-Dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide bromide (MTT) assays corroborated that the interaction between rMgPa and RPL35 could promote SV-HUC-1 cell proliferation. Therefore, our findings indicated that the interaction between rMgPa and RPL35 can enhance the expressions of transcription-initiation and translation-related proteins and thus promote cell proliferation. This study elucidates a new biological function of MgPa and can explain this new mechanism of M. genitalium in the host.

Highlights

Mycoplasma genitalium is an emerging pathogen causing genitourinary tract infections in both men and women
The T7 phage-displayed cDNA library of SV-HUC-1 cells was constructed in order to screen the recombinant MgPa (rMgPa)-interacting proteins from the human urethral epithelium
The exogenous DNA fragments inserted into phages were all within the range of 250–1000 bp, which demonstrated that the library has good diversity

Summary

Introduction

Mycoplasma genitalium is an emerging pathogen causing genitourinary tract infections in both men and women. The bacterium is reportedly linked to male urethritis and adverse reproductive sequelae in women, including cervicitis, endometritis, pelvic inflammatory diseases, and nongonococcal urethritis [1]. Researchers have proven that M. genitalium is closely associated with human immunodeficiency virus (HIV) infection and can promote the replication of HIV after invading host cells [2,3,4]. M. genitalium can combine with motile male sperm and, lead to diffuse infection, which causes reproductive diseases and infertility [5]. The initial adhesion of M. genitalium to host cells is considered to be essential for the colonization of M. genitalium, leading subsequently to human urethritis [6].

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