The Role Of Intelectin In Cigarette Smoke-Induced Pulmonary Inflammation

Partâ… The Expression of Intelectin, Interleukin 6 (IL-6) and monocyte chemotatic protein 1 (MCP-1) in Mouse Lung Epithelial Cells (MLE-12) after Cigarette Smoke Extract StimulationObsjecive Preparing for the next step of research by detecting the expression of intelectin, IL-6 and MCP-1 in mouse lung epithelial cell (MLE-12) after cigarette smoke extract (CSE) stimulation.Methods Firstly we chosed the proper concentration and stimulating time of CSE on MLE-12 cells through deciding the toxicity of CSE on MLE-12 cells. Then quantitive PCR was used to assess intelectin, IL-6 and MCP-1 expression in MLE-12 cells after CSE stimulation.Results Twenty-four hours of stimulation with higher concentration than 10% CSE remarkably decreased the viability of MLE-12 cells. And seventy-two hours of stimulation with higher concentration than 2.5% CSE the viability decreased significantly too. Twenty-four hours of stimulation with CSE (10%) moderately increased intelectin1 and decreased IL-6 production over control. The intelectin2 and MCP-1 expression was not changed. Moreover, twenty-four hours of stimulation with CSE (2.5%) decreased MCP-1 production. Seventy-two hours of stimulation with CSE (2.5%) increased intelectin2 mRNA expression only. Conclusions Our cell experiment results showed CSE increased intlectin and decreased IL-6, MCP-1 expression on mouse lung epithelial cells. The different effects of CSE on these cytokines may depend on the different concentration of CSE and different stimulating time. Using animal models studing the role of intelectin on cigarette smoke-induced pulmonary inflammation should be further performed. The correlation between intelectin upregulation and IL-6, MCP-1 downregulation after CSE stimulation should be further investgated too.Partâ…¡The role of intelectin in interleukin 6(IL-6) and monocyte chemotatic protein 1 (MCP-1) expression of mouse lung epithelial cellsObsjective:We used RNA interference and gene over-expressing technicals to determine whether intelectin was involved in the downregulation of IL-6 and MCP-1 after CSE stimulation of mouse lung epithelial cells.Methods:PGCsi3.0-shRNA plasmid expressing short hairpin RNA targeting intelectin1/2 was constructed and transfected to MLE-12 cells. After CSE stimulating, cells were collected for assessing the expression of intelectin, IL-6 and MCP-1. Moreover, plasmid overexpressing intelectin cDNA was also transfected to MLE-12 cells too. After 48hours, intelectin, IL-6 and MCP-1 expressions were also determined.Results:After transfection with intelectin shRNA targeting conserved sequences in intelectin1/2, expression of intelectin1 transcripts in CSE-stimulated cells was inhibited. We also confirmed that CSE-downregulated IL-6 expression was reversed after intelectin shRNA transfection. The intelectin2 and MCP-1 expression was not changed. In a separate experiment, we discovered that intelectinl transcripts increased after intelectinl cDNA transfection, but the IL-6 expression reduced.Conclusions:In combination with the intelectin shRNA and cDNA transfection results, we concluded that intelectinl was involved in the downregulation of interleukin 6 after CSE stimulation of MLE-12 cells. We inferred that CSE can upregulate intelectinl expression in lung epithelial cells, this upregulation of intelectinl reduced interleukin 6 expression in these cells. Reduction of interlerkin 6 attenuated the anti-infection ability of lung epithelial cells. That may contribute to the susceptibility to pulmonary infection of smokers and chronic obstructive pulmonary disease (COPD) patients. However, this deduction was based on cell experiments in vitro; more experiments in animal models should be further performed to invesgate the role of intelectin in cigarette smoke-induced pulmonary inflammation.Partâ…¢Lentiviral-mediated intelectin1/2 RNAi decreased intelectin expression in mice lung with cigarette smoke treatmentObsjective:To investgate the role of intelectin in cigarette smoke-induced pulmonary inflammation.Methods:We firstly onstructed intelectin1/2 shRNA and cloned it into lenteviral vectors. Intelectin and interleukin 6 expression were detected in mouse lung after intranasal administration of these lentivirus and cigarette exprosure. The total cells counts and differential cell counts in BALF, lung histology including airway inflammation were assessed too.Results:Histological analysis revealed that subacute pulmonary inflammation occurred and inflammatory cell infiltration around airways and alveoli after mice exposed to cigarette smoke 4 weeks. Intelectin2 transcripts and intelectin1/2 protein level increased in lung of smoke-exposed mice. And interleukin 6 transcripts increased too. Moreover, we successfully constructed intelectin shRNA and cloned it into lenteviral vectors. After pre-treatment airway with LPC, intranasal administration of lentivirus inhibited intelectin1/2 but not interleukin 6 expression in lung of smoke-exposed mice. The total cells counts and differential cell counts in BALF and airway inflammation were not attenuated after lentivirus treatment.Conclusions:The level of intelectin and interleukin 6 depended on cigarette smoke-exposed time and the stimulating concentration. After pre-treatment airway with LPC, intranasal administration of lentivirus inhibited intelectin but not interleukin 6 expression in lung of smoke-exposed mice. The total cells counts and differential cell counts in BALF and airway inflammation were not attenuated after lentivirus treatment. Interleukin 6 unchanging may because many kinds of cells including epithelial cells and leucocytes can secret them.