Viral Infection-Induced Differential Expression of LncRNAs Associated with Collagen in Mouse Placentas and Amniotic Sacs

PROBLEM

We have previously determined that long non-coding RNAs (lncRNAs) are differentially expressed in preterm premature rupture of membranes (PPROM) and hypothesized that the collagenolysis ubiquitin-proteasome system may be activated by infection and inflammation. However, direct evidence of the involvement of lncRNAs in transcriptional and posttranscriptional regulation of the infection-triggered alteration of collagen is lacking.

METHOD OF STUDY

A previously developed mouse model with MHV68 viral infection was assessed to determine whether viral infection may induce differential expression of lncRNAs in mouse placentas and amniotic sacs.

RESULTS

Differential expression of lncRNAs that are associated with collagen was found in HMV68 viral-infected, compared to non-infected, mouse placentas and amniotic sacs. Differential expression of messenger RNAs (mRNAs) of collagen was also documented.

CONCLUSIONS

Our data demonstrate, for the first time, that viral infection may induce the differential expression of lncRNAs that are associated with collagen. Based on this finding, we propose that lncRNA may have involved in regulating of infection-induced collagen transcription.

The isolation and characterization of a novel telomerase immortalized first trimester trophoblast cell line, Swan 71

Studies using first trimester trophoblast cells may be limited by the inability to obtain patient samples and/or adequate cell numbers. First trimester trophoblast cell lines have been generated by SV40 transformation or similar methods, however, this approach is known to induce phenotypic and karyotypic abnormalities. The introduction of telomerase has been proposed to be a viable alternative for the immortalization of primary human cells. To investigate whether telomerase-induced immortalization might be a more feasible approach for the generation of first trimester trophoblast cell lines, we isolated primary trophoblast cells from a 7-week normal placenta and infected the cells with human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase. Although this hTERT-infected first trimester trophoblast cell line, which we have named Swan 71, has been propagated for more than 100 passages, it still has attributes that are characteristic of primary first trimester trophoblast cells. The Swan 71 cells are positive for the expression of cytokeratin 7, vimentin and HLA-G, but do not express CD45, CD68 or the Fibroblast Specific Antigen (FSA), CD90/Thy-1. In addition, we also demonstrated that the Swan 71 cells secrete fetal fibronectin (FFN) as well as low levels of human Chorionic Gonadotrophin (hCG). Moreover, the Swan 71 cells exhibit a cytokine and growth factor profile that is similar to primary trophoblast cells and are resistant to Fas, but not TNF-alpha-induced apoptosis. This suggests that the Swan 71 cells may represent a valuable model for future in vitro trophoblast studies.