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  • Downregulation of vimentin in macrophages infected with live Mycobacterium tuberculosis is mediated by Reactive Oxygen Species.

Downregulation of vimentin in macrophages infected with live Mycobacterium tuberculosis is mediated by Reactive Oxygen Species.

Scientific reports (2016-02-16)
P P Mahesh, R J Retnakumar, Sathish Mundayoor

Mycobacterium tuberculosis persists primarily in macrophages after infection and manipulates the host defence pathways in its favour. 2D gel electrophoresis results showed that vimentin, an intermediate filament protein, is downregulated in macrophages infected with live Mycobacterium tuberculosis H37Rv when compared to macrophages infected with heat- killed H37Rv. The downregulation was confirmed by Western blot and quantitative RT-PCR. Besides, the expression of vimentin in avirulent strain, Mycobacterium tuberculosis H37Ra- infected macrophages was similar to the expression in heat-killed H37Rv- infected macrophages. Increased expression of vimentin in H2O2- treated live H37Rv-infected macrophages and decreased expression of vimentin both in NAC and DPI- treated heat-killed H37Rv-infected macrophages showed that vimentin expression is positively regulated by ROS. Ectopic expression of ESAT-6 in macrophages decreased both the level of ROS and the expression of vimentin which implies that Mycobacterium tuberculosis-mediated downregulation of vimentin is at least in part due to the downregulation of ROS by the pathogen. Interestingly, the incubation of macrophages with anti-vimentin antibody increased the ROS production and decreased the survival of H37Rv. In addition, we also showed that the pattern of phosphorylation of vimentin in macrophages by PKA/PKC is different from monocytes, emphasizing a role for vimentin phosphorylation in macrophage differentiation.

Product Number
Product Description

RIPA Buffer
Diphenyleneiodonium chloride, ≥98%
5′-Nucleotides Sodium Salts
Protease Inhibitor Cocktail, for use with mammalian cell and tissue extracts, DMSO solution
RPMI-1640 Medium, HEPES Modification, with L-glutamine and 25mM HEPES, without sodium bicarbonate, powder, suitable for cell culture
Phosphatase Inhibitor Cocktail 2, aqueous solution (dark coloration may develop upon storage, which does not affect the activity)
Phosphatase Inhibitor Cocktail 3, DMSO solution
Gö 6983, ≥97%
IGEPAL® CA-630, for molecular biology
Lipopolysaccharides from Escherichia coli O111:B4, γ-irradiated, BioXtra, suitable for cell culture
Amyloid Protein Non-Aβ Component, ≥80% (HPLC)