ABSTRACT
Background Studies showed that microRNA (miR)-375 suppresses the growth,apoptosis,migration and adhesion of tumor cells,and it plays a regulation to the changes of vascular endothelial growth factor (VEGF) in tumor tissue to arrest neovascularization.However,whether miR-375 intervenes the formation of new blood vessel in eyes is unelucidated.Objective This study was to explore the effects of miR-375 on human retinal capillary endothelial cells (HRCECs) function induced by hypoxia.Methods HRCECs were cultured using IMDM and divided into normal control group,CoCl2 model group,CoCl2 +miR-375 mimic group,CoCl2 +miR-375 mimic control group,CoCl2+miR-375 inhibitor group and CoCl2 +miR-375 inhibitor control group,and hypoxia cell models were created by adding 200 μmol/L CoCl2.MiR-375 and frizzled 4 (FZD4) small interfering RNA (siRNA) were transfected into the cells by 50 nmol/L miRNA lipidosome for 48 hours.The proliferation of the cells was detected by MTT assay;migrated number of the cells was examined by Transwell chamber assay;ELISA was employed to detect the concentrations of VEGF and VE-cadherin in the medium;the expression of β-catenin,cyclinD1,matrix metalloproteinase-2 (MMP2) and VEGF proteins were analyzed by Western blot;tube length of vessel formation was evaluated by Matrigel assay.Cultured cells were divided into normal control group,CoCl2 model group,CoCl2 +mock group and CoCl2 + FZD4 siRNA group,the relative expression of FZD4,a miR-375 targeted gene,was detected by luciferase reporter.Results The relative expression of miR-375 mRNA was significantly increased in the CoCl2 +miR-375 mimic group compared with the CoCl2 + miR-375 mimic control group and reduced in the CoCo2 + miR-375 inhibitor group compared with the CoCo2 + miR-375 inhibitor control group (t =-19.237,8.764,both at P＜0.01),with a higher transfected efficacy for miR-375.The cell proliferative fold,migrated cell number,VEGF and VE-Cadherin contents in the medium and the tube length were significantly different among the CoCl2 model group,CoCl2 +miR-375 mimic group,CoCl2 +miR-375 mimic control group,CoCl2 +miR-375 inhibitor group and CoCl2 +miR-375 inhibitor control group (F =24.324,26.776,14.113,19.225,15.040,all at P＜0.001),and those in the CoCl2 +miR-375 mimic group were evidently reduced in the CoCl2 +miR-375 mimic group compared with the CoCl2 +miR-375 mimic control group,while those in the CoCl2 +miR-375 inhibitor group were considerably elevated in comparison with the CoCl2 +miR-375 inhibitor control group (all at P＜0.01).The expressions of β3-catenin,cyclinD1,MMP2 and VEGF protein were significantly different among the normal control group,CoCl2 model group,CoCl2 +miR-375 mimic group,CoCl2+miR-375 mimic control group,CoCl2 +miR-375 inhibitor group and CoCl2 +miR-375 inhibitor control group (F=11.753,13.283,16.770,10.334,all at P＜0.001).In addition,the cell proliferative fold,migrated cell number and the tube length were significantly increased in the CoCl2 model group and CoCl2+mock group,and those in the CoCl2+FZD4 siRNA group were decreased in comparison with the CoCl2 +mock group (all at P＜0.05).Conclusions MiR-375 inhibits the growth,migration and tube formation ability of HRCECs in hypoxic status probably by regulating the activation of Wnt pathway via directly targeting FZD4.
ABSTRACT
Background Interleukin-6 (IL-6) is a pleiotropic cytokine involving in inflammation and wound healing.Previous report found that IL-6 increases phosphorylated STAT3 (p-STAT3) level and promotes corneal epithelial wound healing by stimulating migration.However,the essential role of IL-6 in corneal epithelial wound healing and the expression changes in diabetic mellitus remains unknown.Objective This study was to explore the roles of IL-6 in corneal epithelial proliferation and wound healing in both normal and diabetic mice.Methods Fifty-two normal C57BL/6 mice were randomized into normal control group (32 mice) and diabetic group (20 mice).Type 1 diabetic mellitus was induced by intraperitoneal injections of 50 mg/kg streptozotocin once per day for consecutive 5 days in the mice of the diabetic group.Whole corneal epithelium was scraped in all mice,and the corneal epithelial defect area was examined by fluorescein staining in 24,48 and 72 hours after corneal epithelium removal.Recombinant mouse IL-6 or anti-IL-6 blocking antibody of 5 μl were subconjunctivally injected according to the grouping and contrasted with PBS injection group or isotype control antibody group,respectively.TKE2 cells,a mouse corneal epithelial stem/progenitor cell line,were trypsinized and incubated in the KSFM with different concentrations of IL-6 or without IL-6,and colony formation efficency (CFE) was examined by crystal violet staining.The expressions of △NP63 and Ki67,specific makers of stem cells,were detected by immunofluorescine technology.The expressions of △NP63,Ki67 and p-STAT3 proteins were assayed in the cells by Western blot,respectively.The expression of IL-6 mRNA and protein in the regenerated corneal epithelium was detected by real time quantitative PCR and ELISA.The use and care of the mice complied with the Statement of Association for Research in Vision and Ophthalmology.Results The percentage of residual corneal epithelium defect area with initial detect area was gradually shrinked over time after PBS and IL-6 injection in both normal control mice and diabetic mice,and the percentage of residual corneal epithelium defect area was significantly reduced in the IL-6 injected group compared with the PBS injected group (normal control group:Fgroup =19.982,P ＜ 0.01;Ftime =589.350,P ＜ 0.01;Diabetic group:Fgroup =25.411,P＜0.01;Ftime =334.807,P＜0.01).The CFE was (13.23± 1.12)％,(15.87± 1.30)％,(21.69±1.62)％,(25.33±1.28)％ and (18.67±1.54)％ in the blank control group and 10,20,50,100 ng/ml IL-6-treated groups,respectively,showing a gradual increase of CFE dependent upon IL-6 concetrations (F =35.547,P＜0.01).The expressions of △NP63,Ki67,p-STAT3 proteins in the cells were gradually increased over time after 50 ng/ml IL-6 treated for 5,10,15,30 and 60 minutes,and the relative expression level of the cytokines was significnatly higher in the IL-6 cultured groups than that without IL-6 culture group (all at P＜0.05).The relative expression of IL-6 mRNA in the regenerated corneal epithelilum was 0.45±0.21 and 1.00±0.16 in the diabetic group and normal control group,respectively,and compared with the normal control group,the expression of IL-6 mRNA reduced by 56％ (t=3.42,P=0.03).The content of IL-6 protein in regenerated corneal epithelium of the diabetic group was (257±12) ng/μl,which was significantly lower than (323 ± 17) ng/μl of the normal control group (t =5.60,P＜0.01).Conclusions IL-6 promotes the proliferation and regeneration of corneal limbal stem cells to repair defected corneal epithelium by activating STAT3 signaling pathway in both normal and diabetic mice,while the blocking of endogenous IL-6 impairs the corneal epithelial cell activation and wound healing.
ABSTRACT
Background Meningothelial cells (MECs) occupy the predominant cell component of barrier between optic nerve and the cerebral spinal fluid,and any change of cerebral fluid components probably affects the MECs function and further impairs the optic nerve.Objective This study was designed to investigate the influence of glutamate,a potentially excitotoxic amino acid,to the functional changes of MECs and provide a theoretical evidence for clarifying the mechanism of optic nerve disorders.Methods Human MECs strains were cultured in vitro and prepared into cell suspension.The cells were inoculated to 96-well plates with the densities of 1 × 104/we11.The glutamate of 100,200,400,600,800 and 1 000 μmol/L was added into medium for 12,24,36,48 and 72 hours,respectively,and the cultured cells without glutamate were used as normal control group.MTS assay was employed to measure the proliferative rate (absorbency) of the cells.The regularly cultured MECs were divided into 600 μmol/L glutamate-treated group and normal control group and the cells were treated for 12 and 24 hours respectively,and the expression of superoxide dismutase (SOD) mRNA and heat shock protein 90 (HSP90) mRNA in the cells was detected by real-time PCR;the level of total anti-oxidative capacity (T-AOC) of the cells was processed by enzyme linked immunosorbent assay (ELISA),and the reactive oxygen species (ROS) production was determined by DCFH-DA probe.Results Cultured MECs grew well and formed 80％ confluence after 72 hours culture.The proliferative rate of the cells were gradually decreased with the increase of glutamate dose and the lapse of affected time,with significant differences among different concentrations of glutamate and various time points (F tration =52.501,P＜0.001;Ftime =8.505,P＜0.001).The relative expression level of SOD mRNA was significantly reduced in the glutamate-treated group compared with the normal control group in both 24 hours and 48 hours after culture (t =20.278,t =16.724,both at P＜0.001),and the expression of HSP90 mRNA in the cells was significantly lower in the glutamate-treated group than that in the normal control group in 24 hours after culture (t =5.065,P =0.002).No significant difference was found in T-AOC activity between glutamate-treated group and normal control group in 24 hours after culture ([30.835±2.094] nmol/(min · L) vs.[32.873±2.317] nmol/(min · L)) (t=1.599,P =1.414).In 48 hours after culture,T-AOC activity was (29.561 ± 1.831) nmol/(min · L) in the glutamate-treated group,which was significantly lower in comparison with normal control group (33.680±2.039) nmol/(min · L)(t =3.682,P =0.004).Fluorescence staining showed that the intensity of green fluorescence of ROS in MECs in the normal control group was weaker than that in the glutamate-treated group under the immunofluorescense microscope.The ROS level was 48.110± 1.712 and 40.982± 1.853 at 24 hours and 48 hours in the glutamate-treated cells,and which was significantly elevated in comparison with 36.608± 1.009 and 37.153 ± 1.424 in the normal control group (t=14.178,P＜0.001;t=4.012,P=0.002).Conclusions Glutamate inhibits the proliferation of MECs in vitro,and excitatory toxicity of glutamate on MECs probably is associated with oxidative stress response.
ABSTRACT
Background Thyroid associated ophthalmopathy (TAO) is an autoimmune disease.Current research on the pathogenesis focuses on common autoantigen.Insulin-like growth factor-1 receptor (IGF-1R) is necessary for the function of IGF-1,also IGF-1 plays an important role in signaling pathway of thyroid stimulating hormone receptor (TSHR).Objective This study was to investigate the effects of IGF-1 on the proliferation,expression of IGF-1R and TSHR on cultured orbital fibroblasts (OFs) derived from TAO.Methods Human orbital tissue was obtained from 17 TAO patients who received orbital adipectomy and 4 normal controls who received cosmetic surgery in West China Hospital from March 2016 to June 2016.OFs were cultured by explant culture with DMEM/F12 containing 5％ fetal bovine serum and identified by immunochemistry.The OFs were treated with different concentrations of IGF-1.IGF-1 at different concentrations (0,50,100,125 μg/L) was added into the medium,respectively,and the proliferation of the cells (absorbancy) was detected by MTS.The percentages of IGF-1R and TSHR expressions in the cells were assayed by flow cytometry.Results Cultured cells appeared to be spindle-like in shape and grew well with abundant cytoplasm.The characteristics of the cells derived from TAO patients were consistant with normal ones.The cells showed the positive response for vimentin and absent respose for desmin,S-100,myoglobin and cytokeratin.The proliferative values of OFs were gradually elevated with the increase of IGF-I dose in both TAO group and normal group (Fgroup =219.639,P＜0.001;F ion =17.752,P＜0.001) with the optimal effects in 100 μg/L IGF-1.The expression levels of IGF-1R in the OFs were (0.009 1 ±0.008 7)％,(0.095 3±0.023 3) ％,(0.083 7±0.022 7) ％ and (0.070 9 ± 0.024 1) ％ in the TAO group,and those in the normal group were (0.0023± 0.0006)％,(0.0093±0.0012)％,(0.0073±0.0015)％ and (0.0083±0.0012)％ after treatment of 50,100,125 μg/L IGF-1.The expression levels of IGF-1 R were significantly higher after treatment of 50,100 and 125 μtg/L IGF-1 than those treatment of 0 μg/L IGF-1 in both TAO group and normal group,and the expression levels of IGF-1R in the OFs were significantly increased in the TAO group compared with the normal group (all at P＜0.05).No statistical difference was seen in the TSHR expression between the TAO group and normal group after treatment of 0,50,100 and 125 μg/L IGF-1 (Fgroup =0.133,P ＞ 0.05;F ion =0.004,P ＞ 0.05).Conclusions IGF-1 can promote the proliferation of OFs and up-regulate the expression of IGF-1R in OFs.However,IGF-1 dose not play a regulating effect on the expression of TSHR in OFs.