Morphological Study On The Interaction Between Human Macrophages And Renal Calculi Crystal With Microscopical Technique In Vitro

Objective To study the interaction of renal calculi crystals with U937-derivedmacrophages in vitro, to observe morphology of cell-crystal reaction, and toinvestigate the potential role of macrophages in the formation of renal calculicrystals.Methods Macrophages were differentiated from U937human monocytic cellline by activated with phorbol-12-myristate-13-acetate (PMA) in vitro，whowere co-cultured with a variety of crystals. The cell-crystal reaction wasdetected by an inverted phase-contrast microscope, scanning electronmicroscopy (SEM), and live-cell imaging technologies. The amount of calciumdeposition was quantified through the extraction of the Alizarin Red S stain fromcell matrix using a cetylpyridinium chloride extraction method.Result We have observed the adhesion and phagocytosis of crystals by themacrophages under light microscope and SEM; representative results showdynamic processes, including crystals adsorbed, phagocytized, dissolved, and transported by macrophages in morphology with live-cell imaging technologiesmicroscopic imaging techniques. The amount of calcium deposition in HAP(hydroxyapatite)+COM (calcium oxalate monohydrate) group after interacted24hr was higher than any other group(P＜0.05). The difference between HAPgroup and the control group in the same period was statistically significant(P＜0.05),except COM group(P＞0.05).There was no statistical significance in thecontrol group and COM group at the same time(P＞0.05),and the same resultwas reflected in between HAP group and COM group(P＞0.05).The differencebetween12hr period and24hr period in the same treated group was statisticallysignificant(P＜0.05),nevertheless respectively was not in contrast of6hr periodwith statistical value(P＞0.05).There was no interaction at different times indifferent treated groups(P＞0.05).Conclusion Our study detected the macrophages have the activity, which canadhere, phagocytize, and transport the renal calculi crystals. Our findingsenlightened the possible role of HAP crystals in enhanced HAP andCOM-phagocytized activity of the HAP-exposed macrophages, and evenmediated COM-phagocytized activity.