Effects of blue light-exposed retinal pigment epithelial cells on the process of ametropia

Ametropia is one of the most common ocular disorders worldwide, to which almost half of visual impairments are attributed. Growing evidence has linked the development of ametropia with ambient light, including blue light, which is ubiquitous in our surroundings and has the highest photonic energy among the visible spectrum. However, the underlying mechanism of blue light-mediated ametropia remains controversial and unclear. In the present study, our data demonstrated that exposure of the retinal pigment epithelium (RPE) to blue light elevated the levels of the vital ametropia-related factor type Ⅰ collagen (COL1) via β-catenin inhibition in scleral fibroblasts, leading to axial ametropia (hyperopic shift). Herein, our study provides evidence for the vital role of blue light-induced RPE dysfunction in the process of blue light-mediated ametropia, providing intriguing insights into ametropic aetiology and pathology by proposing a link among blue light, RPE dysfunction and ametropia.

[Effect of temporomandibular joint disc perforation on expression of type Ⅰ collagen in temporomandibular joint disc cells]

Objective: To investigate the effect of temporomandibular joint (TMJ) disc perforation on expression of type Ⅰ collagen in TMJ disc cells. Methods: The fibroblastic-like cells from the surgical removed TMJ disc tissue (disc perforation or TMJ condyle hyperplasia) were cultured. The cultured cells were identified as fibroblastic-like cells by toluidine blue and immunofluorescence staining. The expression of type Ⅰ collagen was detected with Western blotting and the content of type Ⅰ collagen was examined by enzyme linked immunosorbent assay (ELISA). Results: Fibroblastic-like cells were cultured from TMJ disc cells and the controls. The collagen-Ⅰ and collagen-Ⅱ were positive in both toluidine blue and immunofluorescence staining. In Western blotting, the expression of typeⅠcollagen in cells from joints with disc perforation was lower than that from normal joints. The content of collagen-Ⅰ was (1.62±0.52) μg/L from controls, and (0.85±0.33) μg/L from disc perforation respectively (P=0.0134). Conclusions: The disc cells from TMJ with disc perforation expressed lower type Ⅰ collagen than that from controls, which may be related to the lower content of collagen-Ⅰ in TMJ disc and the formation of TMJ disc perforation.

Impact of upregulation of miR-203 on cell proliferation and collagen synthesis in hepatic stellate cells

AIM: To investigate the impact of upregulation of miR-203 on cell proliferation and collagen synthesis in hepatic stellate cells.

METHODS: HSC-T6 cells were transfected with miR-203 mimic using Lipofectamine™ 2000, and propagated for 48 h. Total proteins and total RNAs were extracted from these cells. The mRNA and protein expression of α-smooth muscle actin (α-SMA), type Ⅰ collagen and type Ⅲ collagen was measured by RT-qPCR and Western blot, respectively. The proliferation of HSC-T6 cells was assessed using MTT assay.

RESULTS: Compared with the negative control group, α-SMA protein and mRNA expression in the miR-203 mimic group decreased by 75% and 80%, respectively (P < 0.01); type Ⅰ collagen protein and mRNA expression decreased by 56% (P < 0.01) and 48% (P < 0.05), respectively; type Ⅲ collagen protein and mRNA expression decreased 45% and 60%, respectively (P < 0.05); cellular proliferative activity decreased by 20% ± 5% (P < 0.01).

CONCLUSION: Upregulation of miR-203 can significantly inhibit cell proliferation and collagen synthesis in hepatic stellate cells.