lncRNA MEG3, Acting as a ceRNA, Modulates RPE Differentiation Through the miR-7-5p/Pax6 Axis.

Accumulated evidence indicated that long non-coding RNAs (lncRNAs) involves in numerous biological and pathological processes, including age-related macular degeneration (AMD). Dysfunction and dedifferentiation of retinal pigment epithelium (RPE) cells have been demonstrated to be one of the crucial factor in AMD etiology. Herein, we aim to investigate the essential role of lncRNA maternally expressed gene 3 (MEG3) in AMD progression. Expression patterns of MEG3 were measured in dysfunctional REP cells exposed with H2O2 or TNF-α using qRT-PCR assay. Specifically, the intercellular distribution of MEG3 in REP cells was further explored using the subcellular fraction detection. Relative expression of RPE markers or RPE dedifferentiation-related markers was determined using qRT-PCR and western blot analysis, respectively. Immunofluorescence staining was performed to examine the expressions of RPE markers ZO-1 and ß-catenin. Concentration of vascular endothelial growth factor (VEGFA) in the supernatant was detected using ELISA kit. Luciferase reporter assay was performed to verify the MEG3/miR-7-5p/Pax6 regulatory network, which was further determined in in vitro studies. MEG3 expression was significantly decreased in H2O2 or TNF-α-treated REP cells, and it was upregulated along with RPE differentiation. Reduced MEG3 expression resulted in RPE dedifferentiation, which was indicated by decreased expressions of RPE markers, accumulated mitochondrial reactive oxygen species, and reduced VEGFA. Mechanistically, MEG3 functioned as a sponge for miR-7-5p to restore the expression of Pax6. Our study demonstrated that MEG3 exerts a protective role against AMD by maintaining RPE differentiation via miR-7-5p/Pax6 axis, suggesting a protective therapeutic target in AMD treatment.

Baicalin Alleviates Age-Related Macular Degeneration via miR-223/NLRP3-Regulated Pyroptosis.

BACKGROUND: Age-related macular degeneration (AMD), a major eye degenerative disease, ultimately causes irreversible vision loss. Baicalin was identified to attenuate laser-induced chorodial neovascularization, indicating a therapeutic role in AMD. However, the exact mechanisms for baicalin in AMD remain unknown. METHODS: MTT assay was performed to access the suitable concentration of baicalin or Aß for treating ARPE-19 cells. CCK-8, morphology, and flow cytometry analysis were performed to evaluate cell viability and pyroptosis of baicalin in Aß-envoked ARPE-19 cells. Quantitative real-time polymerase chain reaction and western blot analysis were subjected to measure the correlation between miR-223 and NLRP3. Luciferase reporter assay was performed to determine their direct relationship. Western blot analysis was subjected to determine pyroptosis-related proteins. RESULTS: Baicalin inhibited Aß-envoked pyroptosis in ARPE-19 cells. Mechanistically, baicalin significantly induced upregulation of miR-223 and downregulation of NLRP3, thus suppressing pyroptosis triggered by NLRP3 inflammasome signaling, yet such beneficial effects were reversed by miR-223 knockdown. Additionally, MCC950, a NLRP3 inhibitor, restored anti-pyroptosis activity of baicalin under miR-223 silencing. CONCLUSION: Baicalin alleviates intracellular pyroptosis and viability damage resulted from Aß inducement in human retinal pigment epithelium cells via negative crosstalk of miR-223/NLRP3 inflammasome signaling, indicating that baicalin may be considered as a potential candidate for AMD therapy.

NFE2/miR-423-5p/TFF1 axis regulates high glucose-induced apoptosis in retinal pigment epithelial cells.

BACKGROUND: A study has shown that miR-423-5p is highly expressed in proliferative diabetic retinopathy. However, the exact biological functions and mechanisms of miR-423-5p in diabetic retinopathy (DR) progression are currently unclear. This study aimed to investigate the role of miR-423-5p in DR and the underlying mechanism. RESULTS: Our data demonstrate that the expression of miR-423-5p is significantly increased in HG-induced RPE cells and DR patient plasma. Moreover, the overexpression of miR-423-5p exacerbates HG-induced apoptosis. Mechanistically, our results provide evidence that miR-423-5p directly targets TFF1. MiR-423-5p exerts its effect on HG-induced apoptosis in RPE cells through TFF1, and the NF-κB pathway is involved in the regulatory mechanism. Further analysis revealed that the transcription factor NFE2 regulates miR-423-5p promoter activity. In addition, NFE2 regulates the levels of TFF1 and NF-κB pathway-associated proteins by regulating the expression of miR-423-5p. CONCLUSION: The NFE2-miR-423-5p-TFF1 axis is a novel molecular mechanism and provides a new direction for the study and treatment of DR.

Alveolar bone thickness around maxillary central incisors of different inclination assessed with cone-beam computed tomography.

OBJECTIVE: To assess the labial and lingual alveolar bone thickness in adults with maxillary central incisors of different inclination by cone-beam computed tomography (CBCT). METHODS: Ninety maxillary central incisors from 45 patients were divided into three groups based on the maxillary central incisors to palatal plane angle; lingual-inclined, normal, and labial-inclined. Reformatted CBCT images were used to measure the labial and lingual alveolar bone thickness (ABT) at intervals corresponding to every 1/10 of the root length. The sum of labial ABT and lingual ABT at the level of the root apex was used to calculate the total ABT (TABT). The number of teeth exhibiting alveolar fenestration and dehiscence in each group was also tallied. One-way analysis of variance and Tukey's honestly significant difference test were applied for statistical analysis. RESULTS: The labial ABT and TABT values at the root apex in the lingual-inclined group were significantly lower than in the other groups (p < 0.05). Lingual and labial ABT values were very low at the cervical level in the lingual-inclined and normal groups. There was a higher prevalence of alveolar fenestration in the lingual-inclined group. CONCLUSIONS: Lingual-inclined maxillary central incisors have less bone support at the level of the root apex and a greater frequency of alveolar bone defects than normal maxillary central incisors. The bone plate at the marginal level is also very thin.

[The relationship between labial-lingual inclination and the thickness of the alveolar bone in the mandibular central incisors assessed with cone-beam computed tomography].

PURPOSE: To investigate the alveolar bone thickness of mandibular central incisors with different labial-lingual inclinations by cone-beam computed tomography (CBCT). METHODS: CBCT and lateral cephalometric images of 60 patients were chosen. The data was respectively classified into 3 groups by L1-MP: lingual inclination group (L1-MP<85.6°); normal group (L1-MP 85.6°-99.6°), and labial inclination group(L1-MP>99.6°). Three-dimensional reconstruction was made for CBCT, and the sagittal images of the largest alveolar bone area along the tooth axis were chosen. The central incisor roots were divided into 4 sections from cementoenamel junction to root apex, then the labial and lingual alveolar bone thickness were measured and added up to get total alveolar bone thickness, and the occurrence of fenestration and dehiscence were recorded. The data was analyzed with SPSS 17.0 software package. RESULTS: The alveolar bone thickness on lingual side and the total bone thickness were significantly different between every 2 sections of all the measured zone. The average values of bone thickness on labial side were thinner than that on lingual side in sections of middle 1/2, root apex 1/4 and root apex. The total bone and lingual bone were thinner in lingual inclination group than in labial inclination group at root apex, root apex 1/4 and middle 1/2. Labial and lingual inclination group were more likely to develop dehiscence (P<0.05). CONCLUSIONS: Lingual and total alveolar bone of central incisors become increasingly thinner from root apex area to cementoenamel junction. The total bone and lingual bone are thinner in lingual inclination group than in labial inclination group. Labial or lingual inclined incisors have higher incidence of dehiscence.