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Polyamines in mycoplasmas and in mycoplasma-infected tumour cells
Abstract:
Three out of four different mycoplasma strains analysed for the polyamine contents contained relatively high concentrations of putrescine, cadaverine, spermidine and spermine. In addition to ornithine decarboxylase (EC 4.1.1.17) activity, the mycoplasmas also exhibited comparable or higher lysine decarboxylase (EC 4.1.1.18) activity fully resistant to the action of 2-difluoromethylornithine, an irreversible inhibitor of eukaryotic ornithine decarboxylase. 2-Difluoromethylornithine did not modify the polyamine pattern of actively growing mycoplasmas. Ehrlich ascites carcinoma cells and L1210 mouse leukemia cells infected with any of the four mycoplasma strains contained, in addition to putrescine, spermidine and spermine, and also easily measurable concentrations of cadaverine; the latter diamine was absent in uninfected cultures. When the infected cells were exposed to difluoromethylornithine, the accumulation of cadaverine was markedly enhanced. The modification of cellular polyamine pattern by mycoplasmas, especially in the presence of inhibitors of eukaryotic ornithine decarboxylase, could conceivably be used as an indicator of mycoplasma infection in cultured animal cells.
Insights
Mycoplasma strains alter host cell polyamine levels, producing cadaverine. This change, especially with ornithine decarboxylase inhibitors, can indicate mycoplasma infection in animal cell cultures.
Area of Science:
- Microbiology
- Biochemistry
- Cell Biology
Background:
- Polyamines are essential for cell growth and proliferation.
- Mycoplasma infections can alter host cell metabolism.
- Specific enzymes like ornithine decarboxylase (ODC) regulate polyamine synthesis.
Purpose of the Study:
- To investigate the polyamine profiles of mycoplasma strains.
- To determine the effect of mycoplasma infection on host cell polyamine content.
- To evaluate the potential of polyamine modification as a biomarker for mycoplasma infection.
Main Methods:
- Analysis of polyamine concentrations (putrescine, cadaverine, spermidine, spermine) in four mycoplasma strains.
- Assay of ornithine decarboxylase (EC 4.1.1.17) and lysine decarboxylase (EC 4.1.1.18) activities.
- Treatment of infected and uninfected Ehrlich ascites carcinoma and L1210 mouse leukemia cells with 2-difluoromethylornithine, an ODC inhibitor.
Main Results:
- Three of four mycoplasma strains showed high levels of putrescine, cadaverine, spermidine, and spermine.
- Mycoplasmas exhibited lysine decarboxylase activity resistant to 2-difluoromethylornithine.
- Infected cells accumulated cadaverine, which was absent in uninfected cells.
- 2-Difluoromethylornithine enhanced cadaverine accumulation in infected cells.
Conclusions:
- Mycoplasma infection significantly alters the polyamine pattern of host cells.
- The accumulation of cadaverine in infected cells, particularly when treated with ODC inhibitors, serves as a potential indicator of mycoplasma infection.
- This finding offers a novel diagnostic approach for detecting mycoplasma contamination in cell cultures.