Citation:
ABSTRACT [Download PDF] [Read Full Text]
Objective To investigate the expression of latent transforming growth factor-β-binding protein (LTBP), transforming growth factor-β (TGF-β), cyclin-dependent kinase 2 (CDK2) and cyclin D2 (CCND2) in fibrillin-2 ( FBN2) interfering induced mouse retinopathy.
Methods Twenty-seven 8-week-old C57BL/6J mice were randomly divided into normal control group, empty vector group and FBN2 interference group according to the random number table method, with 9 mice in each group.The normal control group was not treated.The empty vector group and FBN2 interference group were intravitreally injected with 3 μl empty vector and 3 μl adeno-associated virus (AAV) carrying the sh-FBN2 interference plasmid in the right eye, respectively.The structural and functional changes of the retina were detected at 4 weeks after injection by optical coherence tomography (OCT) and full-field electroretinography (ERG).The expression and distribution of FBN2 protein in the retina were detected by immunofluorescence staining.The mRNA and protein expression levels of FBN2, LTBP-1, TGF-β2, CDK2 and CCND2 in mouse retina were detected by real-time fluorescence quantitative PCR and Western blot.All experiments complied with the ARVO statement.The research scheme was approved by the Experimental Animal Ethics Committee of Shandong University of Traditional Chinese Medicine (No.2019036).
Results Four weeks after injection, the results of OCT examination showed that compared with normal control and empty vector groups, the retinal pigment cortex of the FBN2 interference group was irregular with high density reflection areas.Full-field ERG results showed that compared with normal control and empty vector groups, the amplitude of Rod-a, Rod-b, Max-a and Max-b waveforms in FBN2 interference group decreased, and the differences were statistically significant (all at P<0.05).The results of immunofluorescence staining showed that FBN2 was expressed in the whole retina, and the fluorescence intensity of FBN2 was weaker in FBN2 interference group than that in normal control and empty vector groups.The fluorescence intensity of FBN2 in normal control group, empty vector group and FBN2 interference group was 16.21±2.21, 15.57±3.63 and 5.32±1.06, respectively, with a statistically significant overall difference ( F=66.03, P<0.05).The fluorescence intensity of FBN2 protein in FBN2 interference group was significantly lower than that in empty carrier group and normal control group (both at P<0.05).Compared with normal control and empty vector groups, the relative expression levels of LTBP-1 and TGF-β2 mRNA and protein were significantly increased in FBN2 interference group, while the relative expression levels of FBN2, CDK2 and CCND2 mRNA and protein were significantly decreased, and the differences were statistically significant (all at P<0.05).
Conclusions The increase of LTBP-1 and TGF-β2 and the decrease of G1/S phase related proteins CDK2 and CCND2 are involved in the development of FBN2-deficient retinopathy.