Environment dependent expression of mycobacterium hormone sensitive lipases: expression pattern under ex-vivo and individual in-vitro stress conditions in M. tuberculosis H37Ra

• Published in: Molecular biology reports Vol. 49; no. 6; pp. 4583 - 4593
• Main Authors: Arya, Stuti, Singh, Parul, Kaur, Jashandeep, Kumar, Arbind, Kaur, Jagdeep
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2022; Springer Nature B.V
• Subjects: Aerobic conditions; Animal Anatomy; Animal Biochemistry; Biomedical and Life Sciences; Environmental conditions; Histology; Life Sciences; Lipase; Lipids; Morphology; Nutrient deficiency; Original Article; rRNA; Stationary phase; Tuberculosis; HSL; Stress conditions; Lipids; Gene expression; Survival; Mtb
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-022-07305-4

Background Hormone-sensitive lipase (HSL) is a neutral lipase capable of hydrolysing various kinds of lipids. In comparison to single human Hormone Sensitive Lipase (hHSL), that is induced under nutritional stress, twelve serine hydrolases are annotated as HSL in Mycobacterium tuberculosis (mHSL). Mycobacterium is exposed to multiple stresses inside the host. Therefore, the present study was carried out to investigate if mHSL are also expressed under stress condition and if there is any correlation between various stress conditions and expression pattern of mHSL. Methods and results The expression pattern of mHSL under different environmental conditions ( in-vitro and ex -vivo ) were studied using qRT-PCR in M. tuberculosis H37Ra strain with 16  S rRNA as internal control. Out of 12, only two genes (lipU and lipY) were expressed at very low level in mid log phase culture under aerobic conditions, while 9 genes were expressed at stationary phase of growth. Ten mHSLs were expressed post-infection under ex-vivo conditions in time dependent manner. LipH and lipQ did not express at any time point under ex-vivo condition. The relative expression of most of the genes under individual stress was much higher than observed in ex-vivo conditions. The expression pattern of genes varied with change in stress condition. Conclusions Different sets of mHSL genes were expressed under different individual stress conditions pointing towards the requirement of different mHSL to combat different stress conditions. Overall, most of the mHSLs have demonstrated stress dependent expression pointing towards their role in intracellular survival of mycobacteria.