Yanni Yang

Diabetic retinopathy (DR) seriously endangers human beings' health, uncovering the underlying mechanism might help to cure DR. In this study, we found that the effects of glucose on retinal pigment epithelium (RPE) varies in a dose dependent manner, high-glucose (50mM) promotes reactive oxygen species (ROS) generation and cell apoptosis, inhibits cell mitophagy as well as proliferative abilities, while low-glucose (15mM) induces ROS production and cell mitophagy, but has little impacts on cell apoptosis and proliferation. Of note, the toxic effects of high-glucose (50mM) on RPE are alleviated by ROS scavengers and aggravated by autophagy inhibitor 3-methyladenine (3-MA) or mitophagy inhibitor cyclosporin A (CsA). High-glucose (50mM) induced ROS generation is merely eliminated by ROS scavengers instead of mitophagy or autophagy inhibitor. We also proved that high-glucose (50mM) inhibits cell proliferation and promotes cell apoptosis by regulating ROS mediated inhibition of mitophagy. In addition, mitophagy associated proteins PINK1 and Parkin are downregulated by high-glucose (50mM) or hydrogen peroxide treatments, which are reversed by ROS scavengers. Of note, Knock-down of PINK1 decreases phospharylated Parkin instead of total Parkin levels in RPE. Intriguingly, high-glucose's inhibiting effects on cell mitophagy as well as proliferation and its promoting effects on cell apoptosis are reversed by either PINK1 or Parkin overexpression. Therefore, we concluded that high-glucose promotes RPE apoptosis and inhibits cell proliferation as well as mitophagy by regulating ROS mediated inactivation of ROS/PINK1/Parkin signal pathway.

experiments showed that inhibition of lncRNA ZFAS1 abolished BLM-induced lipid peroxidation and PF development. Mechanistically, silencing of lncRNA ZFAS1 attenuated ferroptosis and PF progression by lncRNA ZFAS1 acting as a competing endogenous RNA (ceRNA) and sponging miR-150-5p to downregulate SLC38A1 expression. Collectively, our studies demonstrated the role of the lncRNA ZFAS1/miR-150-5p/SLC38A1 axis in the progression of PF, and may provide a new biomarker for the treatment of PF patients.

A) modifications. However, it is still unclear whether METTL3 involves in the pathogenesis of diabetic retinopathy (DR). In the present study, we found that high-glucose inhibited RPE cell proliferation, promoted cell apoptosis and pyroptosis in a time-dependent manner. In addition, both METTL3 mRNA and miR-25-3p were low-expressed in the peripheral venous blood samples of diabetes mellitus (DM) patients compared to normal volunteers, and high-glucose inhibited METTL3 and miR-25-3p expressions in RPE cells. As expected, upregulation of METTL3 and miR-25-3p alleviated the cytotoxic effects of high-glucose on RPE cells, and knock-down of METTL3 and miR-25-3p had opposite effects. Additionally, METTL3 overexpression increased miR-25-3p levels in RPE cells in a microprocessor protein DGCR8-dependent manner, and miR-25-3p ablation abrogated the effects of overexpressed METTL3 on cell functions in high-glucose treated RPE cells. Furthermore, PTEN could be negatively regulated by miR-25-3p, and overexpression of METTL3 increased phosphorylated Akt (p-Akt) levels by targeting miR-25-3p/PTEN axis. Consistently, upregulation of PTEN abrogated the protective effects of METTL3 overexpression on RPE cells treated with high-glucose. Collectively, METTL3 rescued cell viability in high-glucose treated RPE cells by targeting miR-25-3p/PTEN/Akt signaling cascade.

BACKGROUND: Interleukin-27 (IL-27) is a multifunctional cytokine with both pro-inflammatory and immunoregulatory functions. At present, the role of IL-27 in pulmonary fibrosis remains unknown. METHODS: In this study, we observed the expression of IL-27/IL-27R in a mouse model of bleomycin (BLM)-induced pulmonary fibrosis. We verified the role of IL-27 using hematoxylin and eosin as well as Masson's staining methods and measuring the content of hydroxyproline as well as collagen I and III. We assessed the differentiation of T lymphocytes in the spleen and measured the concentration of cytokines in bronchoalveolar lavage fluid (BALF) and the expression level of relevant proteins in the JAK/STAT and TGF-ß/Smad signaling pathways in lung tissue. RESULTS: Increased IL-27 expression in BLM-induced pulmonary fibrosis was noted. IL-27 treatment may alleviate pulmonary fibrosis and increase the survival of mice. IL-27 inhibited the development of CD4(+) IL-17(+), CD4(+) IL-4(+) T, and CD4(+) Foxp3(+) cells and the secretion of IL-17, IL-4, IL-6, and TGF-ß. IL-27 induced the production of CD4(+) IL-10(+) and CD4(+) INF-γ(+) T cells. IL-27 decreased the levels of phosphorylated STAT1, STAT3, STAT5, Smad1, and Smad3 but increased the level of SOCS3. CONCLUSIONS: This study demonstrates that IL-27 potentially attenuates BLM-induced pulmonary fibrosis by regulating Th17 differentiation and cytokine secretion.

Much evidence suggests that immune imbalance in the lung plays a crucial role in the development of pulmonary fibrosis. Recently, all-trans retinoic acid (ATRA) shifting the regulatory T/T-helper 17 (Treg/Th17) profile had been proven in some diseases. However, to date, the effect of ARTA of pulmonary fibrosis has not been examined from this aspect. The objective of this study was to study the effect of ATRA on bleomycin-induced pulmonary fibrosis in mice and its possible mechanism. Pulmonary fibrosis was induced in C57BL/6 male mice by intratracheal instillation of bleomycin (5 mg.kg(-1)), which were randomly divided into control, bleomycin, and ATRA groups. Five mice in each group were sacrificed on day 28 after intratracheal instillation. Hemotoxylin and eosin (H&E) and Masson staining were used for pathological examination, and hydroxyproline in lung tissue was measured. Interleukin (IL)-17A protein expression was observed in lung with immunohistochemistry. The expression of IL-17A, IL-10, IL-6, and transforming growth factor (TGF)-β mRNAs were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Th17 and Treg expression in spleen lymphocytes were measured by flow cytometry. H&E and masson staining and expression of hydroxyproline showed that ATRA significantly alleviated lung fibrosis than in the bleomycin group. The expression of IL-17A, IL-10, IL-6, and TGF-β mRNAs were higher in the bleomycin group than in the normal group. ATRA can decrease these cytokines except for IL-10. CD4+CD25+ Treg cell ratio in the bleomycin group was significantly lower than normal, but CD4+IL-17+ T cells was higher; ARTA reversed this kind of expression. ATRA may ease the bleomycin-induced pulmonary fibrosis by inhibiting the expression of IL-6 and TGF-β, shifting the Treg/Th17 ratio and reducing the secretion of IL-17A.