A Pilot Study Of Effect Of Oleic Acid On The SP-B Expression In A Model Of Lung Injury In Vitro

Objective: Detecating the concentration of TNF-ɑ in the suprenatant of A549cells wereincubated with OA to realize the relationship of TNF-ɑ and themechanism of cell damage.Exploring the relationship between OA and ARDS and establish a rational ARDS in vitroexperimental model by detecting the expression and distribution of SP-B after A549cellswere stimulated by OA to provide a new ideas and experimental evidence to the clinicalprecaution and therapy of the ARDS disease.Methods: After A549cell have been cultivated for a time, it has been divided into thecontrol and the experimental group. A549Cells were incubated with OA (oleic acid) atdifferent concentration during24hours and cell proliferation was measured by CKK-8. Weobserve the morphology change of the cultured cell. We detect the expression anddistribution of SP-B in all groups by immunocytochemical method, and the concentrationof TNF-ɑwas determined by ELISA.Results:1. Morphology of A549cell: In the control group, the shape of A549cell ispolygon, abundant kytoplasm, cell process manifest, adherence grow. After A549cellswere incubated with OA (oleic acid) at300μmol/L concentration, the shape of the cellschange round, volume contract and appear a little inequality of size grain in the kytoplasm.After A549cells were incubated with OA (oleic acid) at400μmol/L concentration, theshape of A549cell change round obviously, the endochylema lucency, emphysema reduceand appear abundant inequality of size thickness grain in the kytoplasm. After A549cellswere incubated with OA (oleic acid) at500μmol/L concentration, the organelle collapse.2. The cell OD was detected using the CCK-8method. The cell proliferationwas suppressed after A549cells induced by OA for24h. Compared with the controlgroup, the OD of A549cells treated with OA decreased significantly at24h. There wasstatistical significance among groups of treatment concentration at24h.3. ELISA showed there were no significant differences in the TNF-α levels inA549cells by OA(300μmol/L,400μmol/L,500μmol/L) groups at3,6,12,24h,compared with control group.4. The immunocytochemical staining results showed Compared with control group(0.2647±0.06317), the expression of SP-B was decreased in two experimentalgroup(300μmol/L:0.1379±0.01934;400μmol/L:0.0873±0.02144, P<0.05).Conclusion:1. The model of oleic acid-induced in vitro lung injury of ATⅡ wasestablished successfully。2. OA can not only induce the cell morphology change of A549cell, but alsomay down regulate the expression of SP-B.3. The mechanism of oleic acid causes the AT Ⅱ injury directly to downregulate the expression of SP-B may not through inflammatory mediators and orinflammatory signaling pathways.