Interactions between mycoplasma lipid-associated membrane proteins and the host cells

Mycoplamas are a group of wall-less prokaryotes widely distributed in nature, some of which are pathogenic for humans and animals. There are many lipoproteins anchored on the outer face of the plasma membrane, called lipid-associated membrane proteins (LAMPs). LAMPs are highly antigenic and could undergo phase and size variation, and are recognized by the innate immune system through Toll-like receptors (TLR) 2 and 6. LAMPs can modulate the immune system, and could induce immune cells apoptosis or death. In addition, they may associate with malignant transformation of host cells and are also con-sidered to be cofactors in the progression of AIDS.

Expression of inducible nitric oxide synthase induced by lipid-associated membrane proteins of Ureaplasma urealyticum is regulated by nuclear factor κB-mediated mechanism in murine macrophages

The aim was to investigate the molecular mechanisms responsible for the inducible nitric oxide synthase （iNOS） gene expression stimulated by lipid associated membrane proteins （LAMPs） of Ureaplasma urealytictan （ U. urealyticum ）. Detection of NO, the expression of iNOS and the activation of nuclear factor κB （NF-κB） in direct response to U. urealyticum LAMPs in a murine macrophages, the effects of pyrrolidine dithiocarbamate （PDTC）, an inhibitor of NF-κB and of cycloheximide （CHX）, a protein synthase inhibitor were available. The results indicated that U. urealyticum LAMPs stimulated mouse macrophages to express iNOS and thus produce NO in dose- and time-dependent manner by activating NF-κB. The expression of iNOS, NO production and the activation of NF-κB were inhibited by U. urealyticum LAMPs combination with PDTC or CHX. In conclusion, our findings suggest that U. urealyticum may be an etiological factor to certain diseases due to its ability to stimulate the expression of iNOS, which is probably mediated through the activation of NF-κB.

Ureaplasma urealyticum-derived lipid-associated membrane proteins introduce IL-6, IL-8, and TNF-α cytokines into human amniotic epithelial cells via Toll-like receptor 2

Objective： The purpose of this study was to determine the role of Ureaplasma urealyticum-derived lipidassociated membrane proteins （LAMPs） in the host innate immune system, specifically their effect on Toll-like receptors （TLRs）. Methods： LAMPs were derived from U. urea/yticum strains, and human amniotic epithelial cells （HAECs） were isolated from healthy full-term placentas. Cytokine concentrations were determined by enzyme-linked immunosorbent assay （ELISA） and TLR2 mRNA by real-time PCR. Expression of TLR2 was confirmed by Western blotting and immunohistochemistry. Results： LAMPs induced HAECs to produce inflammatory cytokines interleukin （IL）-6, IL-8, and tumor necrosis factor （TNF）-α. Cytokine production was reduced after blocking TLR2 using TLR2 inhibitor （anti-hTLR2-IgA）. Conclusions： LAMPs isolated from U. urealyticum induced TLR2-dependent up-regulation of inflammatory genes and cytokines in HAECs.

DBLiPro:A Database for Lipids and Proteins in Human Lipid Metabolism

To help researchers in the field of biology,medicine,chemistry,and materials science to use lipidomic data conveniently,there is an urgent need to develop a platform that provides a systematic knowledgebase of human lipid metabolism and lipidome-centric omics analysis tools.DBLiPro is a user-friendly webserver allowing for access to human metabolism-related lipids and proteins knowledge database and an interactive bioinformatics integrative analysis workflow for lipidomics,transcriptomics,and proteomics data.In DBLiPro,there are 3109 lipid-associated proteins(LAPs)and 2098 lipid metabolites in the knowledge base section,which were obtained from Uniprot,Kyoto Encyclopedia of Genes and Genomes(KEGG)and were further annotated by information from other public resources in the knowledge base section,such as RaftProt and PubChem.DBLiPro offers a step-by-step interactive analysis workflow for lipidomics,transcriptomics,proteomics,and their integrating multi-omics analysis focusing on the human lipid metabolism.In summary,DBLiPro is capable of helping users discover key molecules(lipids and proteins)in human lipid metabolism and investigate lipid–protein functions underlying mechanisms based on their own omics data.The DBLiPro is freely available at http://lipid.cloud na.cn/home.