Mycoplasma affects baseline gene expression and the response to glucocorticoids in vocal fold fibroblasts

Abstract

Introduction. In vitro experimentation is intentionally contrived to isolate specific phenomena in the context of profound biological complexity. Mycoplasmas in the upper airway likely contribute to this complexity and play a largely unknown role in both health and disease. Similarly, the presence and role of mycoplasma in in vitro investigation are largely unknown. Hypothesis. We hypothesize mycoplasma in human vocal fold fibroblasts (VFF) will affect both basal gene-expression patterns as well as the cell response to exogenous stimuli. Aim. We sought to determine mycoplasma presence across vocal fold fibroblast cultures, basal transcriptional changes as a function of mycoplasma, and responsiveness to exogenous glucocorticoids in mycoplasma-positive and -negative VFF. Methodology. PCR-based mycoplasma detection was performed in an immortalized human VFF line as well as rat and rabbit primary VFF cultures and extracted rat laryngeal tissue. RNA sequencing was performed in mycoplasma-positive and -negative human cells at baseline and in response to dexamethasone. Results. Mycoplasma was identified in the human cell line as well as primary culture from rabbits. Mycoplasma was not detected in tissue or primary culture from rat vocal folds. Basal mRNA expression in human VFF differed significantly following mycoplasma treatment. In addition, differential responses to dexamethasone were observed across multiple pathways as a function of mycoplasma presence in these cells. Pathways including apoptosis, DNA damage repair, and G1 to S cell cycle signalling were significantly enriched in mycoplasma-positive cells. Conclusion. Variability of mycoplasma presence across culture conditions and differential responses to exogenous stimuli as a function of mycoplasma presence are potentially problematic for the translation of in vitro experimentation in the upper aerodigestive tract. It remains unclear if these findings represent contamination or the baseline state of this specialized tissue.

Characterization of a novel picornavirus prevalent in experimental rabbits (Oryctolagus cuniculus)

“…Rabbits, like other animals, often carry multiple pathogens such as viruses, mycoplasma, chlamydia, bacteria, fungi, and various parasites [ [34] , [35] , [36] , [37] , [38] , [39] ]. In some cases, rabbits encounter poultry raised by humans and living environments, the pathogens carried by them may cause diseases in animals and even spread to humans.…”

Human milk inhibits some enveloped virus infections, including SARS-CoV-2, in an intestinal model

“…However, GSEA matched with other SARS-CoV-2 datasets on intestinal organoids without this contamination and inhibitory effect of milk was verified on mycoplasma negative cultures, we assumed the influence of the contamination was minimal. It is, nonetheless, a confounding variable that is likely to affect baseline gene expression values and should be considered when interpreting our transcriptome findings (Doyle et al, 2021). S2 shown for datasets containing all samples (F, n = 12), most correlated samples (G, n = 2), and least correlated samples (H, n = 2).…”

Sık Kullanılan Bazı Hücre Hatları için Kalite Kontrol: Mikoplazma Kontaminasyon Tespiti, Sitokrom B ve Sitokrom Oksidaz Alt Birim I Genlerinin DNA Dizi Analizlerinin Gerçekleştirilmesi

“…Bununla birlikte mikoplazma kontaminasyonu genellikle gözle kolayca tespit edilemez, ancak varlıkları hücrelerin sağlıklı bir şekilde büyümelerine engeldir (hücrelerde kromozom anomalileri de dâhil birçok sorun oluştururlar) 14,15 . Bu kontaminant hakkındaki bilginin artması ile son birkaç yılda mikoplazma kontaminasyonu nedeniyle sonuçların doğru yayımlanamaması üzerine bir dizi makale yayınlanmıştır 12,13,[16][17][18] . Bu nedenle hücre kültürlerinin sık ve gizli bir kontaminantı olan hücre duvarı bulunmayan mikoplazma hücre kültür çalışmaları için önemli bir tehdittir 14,15,19 .…”