Nintedanib prevents TGF-β2-induced epithelial-mesenchymal transition in retinal pigment epithelial cells

Evaluation of nintedanib efficacy: Attenuating the lens fibrosis in vitro and vivo

PURPOSE

Organ fibrosis is a huge challenge in clinic. There are no drugs for fibrotic cataracts treatments in clinic. Nintedanib is approved by the FDA for pulmonary fibrosis treatments. This study aims to investigate the efficacy and mechanism of nintedanib on fibrotic cataracts.

METHODS

Drug efficacy was validated through TGFβ2-induced cell models and injury-induced anterior subcapsular cataract (ASC) mice. A slit lamp and the eosin staining technique were applied to access the degree of capsular fibrosis. The CCK-8 assay was used to evaluate the toxicity and anti-proliferation ability of the drug. The cell migration was determined by wound healing assay and transwell assay. The anti-epithelial mesenchymal transition (EMT) and anti-fibrosis efficacy were evaluated by qRT-PCR, immunoblot, and immunofluorescence. The inhibition of nintedanib to signaling pathways was certified by immunoblot.

RESULTS

Nintedanib inhibited the migration and proliferation of TGFβ2-induced cell models. Nintedanib can also repress the EMT and fibrosis of the lens epithelial cells. The intracameral injection of nintedanib can also allay the anterior subcapsular opacification in ASC mice. The TGFβ2/ Smad and non-Smad signaling pathways can be blocked by nintedanib in vitro and in vivo.

CONCLUSION

Nintedanib alleviates fibrotic cataracts by suppressing the TGFβ2/ Smad and non-Smad signaling pathways. Nintedanib is a potential drug for lens fibrosis.

The role of lipid peroxidation in epithelial-mesenchymal transition of retinal pigment epithelial cells

Epithelial-Mesenchymal Transition (EMT) of retinal pigment epithelial (RPE) cells is recognized as pivotal in various retinal diseases. Previous studies have suggested a reciprocal regulation between reactive oxygen species (ROS) and EMT, though the involvement of peroxidized lipids or the effects of reducing them has remained unclear. The present study disclosed that EMT of ARPE-19 cells induced by TGF-β2 and TNF-α involves increased lipid peroxidation, and Ferrostatin-1 (Fer-1), a lipophilic antioxidative agent, successfully inhibited the increase in lipid peroxidation. Fer-1 suppressed the formation of EMT-associated fibrotic deposits, while EMT induction or Fer-1 treatment did not influence the cell viability or proliferation. Functionally, Fer-1 impeded EMT-driven cell migration and reduction in transepithelial electrical resistance. It demonstrated regulatory prowess by downregulating the mesenchymal marker fibronectin, upregulating the epithelial marker ZO-1, and inhibiting the EMT-associated transcriptional factor ZEB1. Additionally, VEGF, a major pathogenic cytokine in various retinal diseases, is also upregulated during EMT, and Fer-1 significantly mitigated the effect. The present study disclosed the involvement of lipid peroxidation in EMT of RPE cells, and suggests the suppression of lipid peroxidation may be a potential therapeutic target in retinal diseases in which EMT is implicated.

PI3Kδ Mediates Fibrosis by Patient-Derived Vitreous

The epithelial-mesenchymal transition (EMT) is a fundamental process in developing fibrotic diseases, including forming epiretinal membranes (ERMs). ERMs can result in irreversible vision loss. Previous research has demonstrated that vitreous (VIT) derived from patients with proliferative diabetic retinopathy can stimulate angiogenesis through the Axl/PI3K/Akt pathway. Building upon this knowledge, we aimed to explore the influence of VIT from patients with macular membranes in ARPE-19 cells. Our findings reveal that patient-derived VIT from individuals with macular membranes promotes EMT and phosphoinositide 3-kinase-delta (PI3Kδ) expression in ARPE-19 cells. To elucidate the function of PI3Kδ in the ERM, we conducted experiments involving the knockout of p110δ, a key subunit of PI3Kδ, and observed that its absence hinders EMT induced by patient-derived VIT. Moreover, p110δ depletion reduces cell proliferation and migration in ARPE-19 cells. Remarkably, these effects were further corroborated by applying the p110δ inhibitor idelalisib, which blocks fibrosis in the laser-induced fibrosis model. Collectively, our results propose that p110δ plays a critical role in the progression of ERMs. Consequently, targeting p110δ emerges as a promising therapeutic approach for mitigating fibrosis. These findings contribute to a better understanding of the underlying mechanisms involved in ERM formation and highlight the potential for p110δ-directed antifibrotic therapy in retinal diseases.

Epithelial-Mesenchymal Transition: A Fundamental Cellular and Microenvironmental Process in Benign and Malignant Prostate Pathologies

Epithelial-mesenchymal transition (EMT) is a crucial and fundamental mechanism in many cellular processes, beginning with embryogenesis via tissue remodulation and wound healing, and plays a vital role in tumorigenesis and metastasis formation. EMT is a complex process that involves many transcription factors and genes that enable the tumor cell to leave the primary location, invade the basement membrane, and send metastasis to other tissues. Moreover, it may help the tumor avoid the immune system and establish radioresistance and chemoresistance. It may also change the normal microenvironment, thus promoting other key factors for tumor survival, such as hypoxia-induced factor-1 (HIF-1) and promoting neoangiogenesis. In this review, we will focus mainly on the role of EMT in benign prostate disease and especially in the process of establishment of malignant prostate tumors, their invasiveness, and aggressive behavior. We will discuss relevant study methods for EMT evaluation and possible clinical implications. We will also introduce clinical trials conducted according to CONSORT 2010 that try to harness EMT properties in the form of circulating tumor cells to predict aggressive patterns of prostate cancer. This review will provide the most up-to-date information to establish a keen understanding of the cellular and microenvironmental processes for developing novel treatment lines by modifying or blocking the pathways.

ERH gene knockdown inhibits the proliferation and migration of ARPE-19 cells through MCM complex and EMT process

PURPOSE

To explore the role of the Enhancer of rudimentary homolog (ERH) gene on the proliferation and migration of ARPE-19 cells, and its mechanism.

METHODS

ARPE-19 cells were divided into ERH gene knockdown (ERH KD) and normal ERH gene (ERH NC) groups and infected with respected virus. Cell counting kit-8 assay, wound-healing assay, and flow cytometry were performed to evaluate the effects of the ERH gene on cell proliferation, migration, and cell cycle. A 4D label-free quantitative proteomic analysis was conducted to obtain the ERH gene knockdown-related differential proteins list (DPL). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein domain analysis, subcellular localization analysis, and protein-protein interaction (PPI) analysis were performed to explore the main downstream functions of the ERH gene. Proteins related to DNA replication, cell cycle, and epithelial-mesenchymal transition (EMT) were identified by Western blot test.

RESULTS

The ERH gene was successfully knocked down in ARPE-19 cells of the ERH KD group. The proliferation and migration of cells were reduced and the cell cycle was arrested at the S phase in the ERH KD group. A DPL of 47 upregulated and 108 downregulated proteins was obtained, and their functions were explored and found to be associated with the MCM complex, DNA replication, and cell cycle. Protein domain analysis, protein subcellular localization analysis, and PPI analysis showed that the MCM complex may play a key role in the proliferation of ARPE-19 cells affected by the ERH gene. DNA replication, cell cycle, and EMT-related proteins were affected when the ERH gene was knocked down.

CONCLUSION

Knockdown of ERH gene inhibits the proliferation and migration of ARPE-19 cells through the MCM complex and EMT process.

The Research Progress in Transforming Growth Factor-β2

Transforming growth factor-beta 2 (TGF-β2), an important member of the TGF-β family, is a secreted protein that is involved in many biological processes, such as cell growth, proliferation, migration, and differentiation. TGF-β2 had been thought to be functionally identical to TGF-β1; however, an increasing number of recent studies uncovered the distinctive features of TGF-β2 in terms of its expression, activation, and biological functions. Mice deficient in TGF-β2 showed remarkable developmental abnormalities in multiple organs, especially the cardiovascular system. Dysregulation of TGF-β2 signalling was associated with tumorigenesis, eye diseases, cardiovascular diseases, immune disorders, as well as motor system diseases. Here, we provide a comprehensive review of the research progress in TGF-β2 to support further research on TGF-β2.

Nintedanib inhibits normal human vitreous-induced epithelial-mesenchymal transition in human retinal pigment epithelial cells

PURPOSE

In this study, we aim to investigate the potential of nintedanib as a therapeutic approach to proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal detachment repair. PVR is characterized by the epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells, and understanding the effects of nintedanib on EMT in the normal human vitreous (HV)-induced RPE cells is crucial.

METHODS

Our research focuses on assessing the impact of nintedanib on HV-induced EMT in human retinal pigment epithelial (ARPE-19) cells in vitro. We employed various techniques, including quantitative real-time PCR (qPCR), western blot analysis, and immunofluorescence staining, to evaluate the mRNA and protein expression of EMT biomarkers in HV-induced ARPE-19 cells. Additionally, we measured the proliferation of RPE cells using cell counting, CCK-8, and Ki-67 assays. Migration was assessed through wound healing and transwell migration assays, while contraction was determined using a collagen gel contraction assay. Morphological changes were examined using phase-contrast microscopy.

RESULTS

Our results demonstrate that nintedanib selectively attenuates the upregulation of mesenchymal markers in HV-induced ARPE-19 cells, at both the mRNA and protein levels. Furthermore, nintedanib effectively suppresses the HV-induced proliferation, migration, and contraction of ARPE-19 cells, while maintaining the cells' basal activity. These findings strongly suggest that nintedanib exhibits protective effects against EMT in ARPE-19 cells and could be a promising therapeutic option for PVR.

CONCLUSIONS

By elucidating the anti-EMT effects of nintedanib in HV-induced RPE cells, our study highlights the potential of this oral triple tyrosine kinase inhibitor in the treatment of PVR. These findings contribute to the growing body of research aimed at developing novel strategies to prevent and manage PVR, ultimately improving the success rates of retinal detachment repair.