Abstract:[Background] LncRNA-GAS5, a functional LncRNA that is encoded by Gas5 gene, plays an important role in the regulation of cell polarization, apoptosis, necrosis and autophagy. [Objective] To investigate the regulatory function of LncRNA-GAS5 on necrosis of macrophage RAW 264.7 induced by Bacillus Calmette-Guérin (BCG) infection. [Methods] The overexpression plasmid and interference plasmid of LncRNA-GAS5 were constructed and transfected into macrophage RAW264.7. Furthermore, the both transfected macrophage were infected by BCG. The cell viability was detected by MTT assay. The morphological changes of necrosis were observed with transmission electron microscope and the necrosis rate was analyzed by flow cytometry. The expression of RIP1, RIP3 and MLKL in mRNA and protein level were determined by qRT-PCR and Western blot. [Results] The expression of LncRNA-GAS5 in macrophage RAW264.7 significantly increased after BCG infection. The cell viability decreased and cell necrosis rate increased significantly when macrophage was transfected with the LncRNA-GAS5 overexpression plasmid alone or combined with BCG infection. Meanwhile, the mRNA and protein expression levels of RIP1, RIP3 and MLKL were upregulated dramatically and this process can be inhibited by LncRNA-GAS5 interference plasmid. [Conclusion] LncRNA-GAS5 can promote necrosis of RAW264.7 infected with BCG by up-regulating necrosis associated factors such as RIP1, RIP3, and MLKL. The results lay foundation on further insight into the molecular mechanisms of macrophage necrosis induced by BCG infection.
