RESUMO
Background Researches showed that triterpenoids,with a similar structure to lanosterol,has therapeutical effect on many systemic diseases,and lanosterol was determined to have a therapeutical effect on cataract recently.However,how the lanosterol plays effects on other eye diseases is still unelucidated.Understanding the distribution of lanosterol in ocular tissue is helpful for us to elucidate the relationship of lanosterol with eye diseases.Objective This study attempted to investigate the distribution of lanosterol synthase (LSS) and lanosterol in cornea,lens and retina tissue of rats and offer a basis for the targeting treatment of eye diseases.Methods Fifteen SPF male SD rats were sacrificed by excessive anesthesia to obtain the eyeballs.The relative expressions of LSS protein and gene in the cornea,lens and retina tissue of the rats were detected by Western blot and reverse transcription (RT)-PCR,respectively.Immunofluorescence staining technology was used to locate the distribution of LSS in cornea,lens and retina tissue.The contents of lanosterol in the cornea,lens and retina tissue were analyzed by liquid chromatograph mass spectrometer (LC-MS).Results No LSS protein and mRNA was expressed in the retinal tissue in normal rats.The mean relative expression of LSS protein in the lens and cornea was 0.43±0.05 and 0.25±0.03,respectively,showing a significant difference between them (t =-5.35,P＜ 0.01).The relative expression of LSS mRNA was 0.51 ±0.04 and 0.29 ±0.02 in the lens and cornea,respectively,with a stronger expression in the lens in comparison with the cornea (t =-8.34,P＜0.01).Immunofluorescence staining showed that LSS primarily located in corneal epithelial layer,stromal layer and endothelial layer as well as lens epithelial cells and shallow cortex layer and hardly expressed in retina,and no co-expression of LSS with the neuron marked by NeuN and the Müller cell marked by glutamine synthetase (GS) in retinal tissue.LC-MS analysis revealed that the contents of lanosterol in lens and cornea was (24.37 ±2.91) ng/mg and (5.31 ±0.58) ng/mg,respectively,with a significant difference between them (t =-11.13,P＜0.01).Conclusions LSS and lanosterol extensively distribute in cornea and lens of normal rats,but not in retina tissue.These results offer new strategies for the target treatment of relevant eye diseases.
RESUMO
Background Retinal microglia (RMG) plays an important role in the pathogenesis of retinal degenerative diseases,while chemokine CX3CL1 participates in the regulation of steady-state of microglia.It has been determined that bone marrow-derived mesenchymal stem cells (BMSCs) have a remarkable role to modulate the immune response and protect the central nervous system through the release of soluble factors in a paracrine fashion and further affect the functional behavior of cells.However,whether BMSCs are able to interact with RMG and activate related signaling pathway for the maintaining of homeostasis in the retina is still unclear.Objective The aim of this study was to investigate the interaction between BMSCs and lipopolysaccharide (LPS)-activated RMG in vitro,and dissect the effects of CX3CL1/CX3CR1 signaling pathway on the biological behavior of BMSCs and RMG.Methods RMG was isolated from SD rats,cultured with mixed culture of retinal glial cells and purified by shaking.The cells were identified by detecting the expression of CD111b,Iba1 and glutamamine synthetase (GS) with indirect immunofluorescence assay.LPS (1 mg/ml,2 μl) was added in the medium for 24 hours to stimulate RMG,and then the cells were divided into LPS control group,BMSCs group (cocultured with BMSCs for 24 hours) and CB-BMSCs group (cocultured with CX3CL1-blocking-BMSCs for 24 hours).The cells without LPS stimulation served as the blank control group.The functions of RMG,including the release content of tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β),the proliferation,phagocytosis,and migration of RMG were examined.Results RMG was successfully isolated and harvested from SD rats by using mixed culture of retinal glial cells and purified by shaking.CD11b and Iba1 showed the positive expression with the green fluorescence in the cells and GS was absent.The contents of TNF-αt in the cell supernatant were (2.55 ±0.97) ng/ml,(24.91 ±3.07) ng/ml,(20.38 ±2.97) ng/ml and (24.90 ± 1.88) ng/ml in the blank control group,LPS control group,BMSCs group and CB-BMSCs group,respectively,showing a significant difference among the groups (F=119.90,P＜0.05).The contents of IL-1 β in the cell supernatant were (1.12±0.36) ng/ml,(10.40±2.76) ng/ml,(7.00± 1.75) ng/ml and (9.55 ± 1.11) ng/ml in the blank control group,LPS control group,BMSCs group and CB-BMSCs group,respectively,showing a significant difference among the groups(F =34.96,P＜0.05).The secretory volume of TNF-α and IL-1 β were evidently lower in the BMSCs group than those in the LPS control group (both at P＜0.05),and no significant differences were found in the secretory volume of TNF-α and IL-1β between CB-BMSCs group and LPS control group (both at P＞0.05).The proliferative rate of RMG was lower in the BMSCs group than that in the LPS control group (P＜0.05),while there was no statistical difference between BMSCs group and CB-BMSCs group (P＞0.05).The mean fluorescence intensity (MFI) and the number of migrated RMG were considerably different among the four groups (F=70.55,15.49,both at P＜0.05),and those in the BMSCs group were significantly increased in comparison with the LPS control group (both at P＜0.05),while there was no significant difference between CB-BMSCs group and LPS control group (both at P＞0.05).Conclusions BMSCs could suppress the proliferation of LPS-activated RMG.Moreover,BMSCs might inhibit proinflammatory cytokines releasing,enhance phagocytosis and migration capabilities of RMG via CX3CL1/CX3CR1 signaling pathway.
