Objective:To explore the expression and mechanism of lncRNA MALAT1 in negative sputum for tuberculous bac-terium.Methods:Expression of lncRNA MALAT1 in peripheral blood mononuclear cells(PBMC)of patients with positive sputum bacteria(Positive group)and negative sputum bacteria(Negative group)and healthy volunteers(HC group)was detected by RT-PCR.ELISA was used to detect expression levels of TNF-α,IL-1β and IL-6 in plasma.Expression of lncRNA MALAT1 in mice macro-phages RAW264.7 was silenced by siRNA interference,and RAW264.7 cells were infected with mycobacterium tuberculosis(MTB)H37Rv.Cells were divided into four groups:Control group,Control+MTB group,MTB+si-NC group and MTB+si-MALAT1 group.Proliferation activity of RAW264.7 cells in each group was detected by CCK-8 method.The number of MTB in each group was detected by CFU.Expressions of TNF-α,IL-1β and IL-6 in supernatant of RAW264.7 cells were detected by ELISA.Results:Compared with HC group,expressions of lncRNA MALAT1 in PBMC,and TNF-α,IL-1β and IL-6 in plasma were significantly increased in Positive group and Negative group(P<0.01).Compared with Control group,expression level of lncRNA MALAT1,proliferation activity,CFU value,and concentrations of TNF-α,IL-1β and IL-6 in supernatant of Control+MTB group,MTB+si-NC group and MTB+si-MALAT1 group were significantly increased(P<0.05).Compared with MTB+si-NC group,the above detection indexes in MTB+si-MALAT1 group were significantly decreased(P<0.05),while there was no significant difference in Control+MTB group(P>0.05).Conclusion:The significantly increased expression of MALAT1 in patients with negative sputum for tuberculous bacterium is positively correlated with expression of plasma inflammatory factors,while the silence of MALAT1 expression can reduce MTB induced inflammatory response by inhibiting the proliferation and phagocytosis of MTB infected macrophages.

Objective:To explore the expression and mechanism of lncRNA MALAT1 in negative sputum for tuberculous bac-terium.Methods:Expression of lncRNA MALAT1 in peripheral blood mononuclear cells(PBMC)of patients with positive sputum bacteria(Positive group)and negative sputum bacteria(Negative group)and healthy volunteers(HC group)was detected by RT-PCR.ELISA was used to detect expression levels of TNF-α,IL-1β and IL-6 in plasma.Expression of lncRNA MALAT1 in mice macro-phages RAW264.7 was silenced by siRNA interference,and RAW264.7 cells were infected with mycobacterium tuberculosis(MTB)H37Rv.Cells were divided into four groups:Control group,Control+MTB group,MTB+si-NC group and MTB+si-MALAT1 group.Proliferation activity of RAW264.7 cells in each group was detected by CCK-8 method.The number of MTB in each group was detected by CFU.Expressions of TNF-α,IL-1β and IL-6 in supernatant of RAW264.7 cells were detected by ELISA.Results:Compared with HC group,expressions of lncRNA MALAT1 in PBMC,and TNF-α,IL-1β and IL-6 in plasma were significantly increased in Positive group and Negative group(P<0.01).Compared with Control group,expression level of lncRNA MALAT1,proliferation activity,CFU value,and concentrations of TNF-α,IL-1β and IL-6 in supernatant of Control+MTB group,MTB+si-NC group and MTB+si-MALAT1 group were significantly increased(P<0.05).Compared with MTB+si-NC group,the above detection indexes in MTB+si-MALAT1 group were significantly decreased(P<0.05),while there was no significant difference in Control+MTB group(P>0.05).Conclusion:The significantly increased expression of MALAT1 in patients with negative sputum for tuberculous bacterium is positively correlated with expression of plasma inflammatory factors,while the silence of MALAT1 expression can reduce MTB induced inflammatory response by inhibiting the proliferation and phagocytosis of MTB infected macrophages.