All‑trans‑retinoic acid modulates TGF‑β‑induced apoptosis, proliferation, migration and extracellular matrix synthesis of conjunctival fibroblasts by inhibiting PI3K/AKT signaling

Pathogenesis of Common Ocular Diseases: Emerging Trends in Extracellular Matrix Remodeling

The prevalence of visual impairments in human societies is worrying due to retinopathy complications of several chronic diseases such as diabetes, cardiovascular diseases, and many more that are on the rise worldwide. Since the proper function of this organ plays a pivotal role in people's quality of life, identifying factors affecting the development/exacerbation of ocular diseases is of particular interest among ophthalmology researchers. The extracellular matrix (ECM) is a reticular, three-dimensional (3D) structure that determines the shape and dimensions of tissues in the body. The ECM remodeling/hemostasis is a critical process in both physiological and pathological conditions. It consists of ECM deposition, degradation, and decrease/increase in the ECM components. However, disregulation of this process and an imbalance between the synthesis and degradation of ECM components are associated with many pathological situations, including ocular disorders. Despite the impact of ECM alterations on the development of ocular diseases, there is not much research conducted in this regard. Therefore, a better understanding in this regard, can pave the way toward discovering plausible strategies to either prevent or treat eye disorders. In this review, we will discuss the importance of ECM changes as a sentimental factor in various ocular diseases based on the research done up to now.

The mechanisms governing mouse embryonic palate mesenchymal cells' proliferation associated with atRA-induced cleft palate in mice: insights from integrated transcriptomic and metabolomic analyses

While exposure to high levels of all-trans retinoic acid (atRA) during pregnancy is known to suppress murine embryonic palate mesenchymal (MEPM) cells proliferation and to result in cleft palate (CP) development, the underlying mechanisms are poorly understood. Accordingly, this study was designed with the goal of clarifying the etiological basis for atRA-induced CP. A murine model of CP was established via the oral administration of atRA to pregnant mice on gestational day (GD) 10.5, after which transcriptomic and metabolomic analyses were performed with the goal of clarifying the critical genes and metabolites associated with CP development through an integrated multi-omics approach. MEPM cells proliferation was altered by atRA exposure as expected, contributing to CP incidence. In total, 110 genes were differentially expressed in the atRA treatment groups, suggesting that atRA may influence key biological processes including stimulus, adhesion, and signaling-related activities. In addition, 133 differentially abundant metabolites were identified including molecules associated with ABC transporters, protein digestion and absorption, mTOR signaling pathway, and the TCA cycle, suggesting a link between these mechanisms and CP. Overall, combined analyses of these transcriptomic and metabolomic results suggested that the MAPK, calcium, PI3K-Akt, Wnt, and mTOR signaling pathways are particularly important pathways enriched in the palatal cleft under conditions of atRA exposure. Together, these integrated transcriptomic and metabolomic approaches provided new evidence with respect to the mechanisms underlying altered MEPM cells proliferation and signal transduction associated with atRA-induced CP, revealing a possible link between oxidative stress and these pathological changes.

All Trans-Retinoic Acids Facilitate the Remodeling of 2D and 3D Cultured Human Conjunctival Fibroblasts

Vitamin A derivative, all-trans-retinoic acid (ATRA), is known to be a potent regulator of the growth and differentiation of various types of cells. In the present study, the unidentified effects of ATRA on superficial and vertical spreading conjunctival scarring were examined. The study involved the use of two-dimensional (2D) and three-dimensional (3D) cultures of human conjunctival fibroblast (HconF) cells in the presence or absence of TGF-β2. The effects of ATRA (1 μM) on superficial or vertical spreading conjunctival scarring were evaluated by the barrier function by trans-endothelial electrical resistance (TEER) and FITC dextran permeability measurements and real-time metabolic analysis, as well as the physical properties, namely, the size and stiffness, of 3D spheroids, respectively. In addition, the expressions of several related molecules, including extracellular matrix (ECM) molecules, ECM modulators including a tissue inhibitor of metalloproteinases (TIMPs), matrix metalloproteinases (MMPs), and ER stress-related factors, were examined. ATRA significantly induced (1) an increase in TEER values and a decrease in FITC dextran permeability, respectively, in the 2D monolayers, and (2) relatively and substantially increased the size and stiffness, respectively, of the 3D spheroids. These ATRA-induced effects were further enhanced in the TGF-β2-treated cells, whereas the TGF-β2-induced enhancement in glycolytic capacity was canceled by the presence of ATRA. Consistent with these physical and morphological effects, the mRNA expressions of several molecules were significantly but differently induced between 2D and 3D cultures by ATRA, although the presence of TGF-β2 did not substantially affect these gene expression levels. The findings reported in this study indicate that ATRA may exacerbate both superficial and vertical conjunctival fibrosis spreading independently of TGF-β2-induced changes.

All-trans Retinoic Acids Synergistically and Beneficially Affect In Vitro Glaucomatous Trabecular Meshwork (TM) Models Using 2D and 3D Cell Cultures of Human TM Cells

We report herein on the effects of all-trans retinoic acid (ATRA) on two-dimensional (2D) and three-dimensional (3D) cultures of human trabecular meshwork (HTM) cells that were treated with transforming growth factor β2 (TGF-β2). In the presence of 5 ng/mL TGF-β2, the effects of ATRA on the following were observed: (1) the barrier function of the 2D HTM monolayers, as determined by trans-endothelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC) dextran permeability measurements; (2) a Seahorse cellular bio-metabolism analysis; (3) physical properties, including the size and stiffness, of 3D spheroids; (4) the gene expression of extracellular matrix (ECM) molecules, ECM modulators including tissue inhibitor of metalloproteinases (TIMPs), matrix metalloproteinases (MMPs), tight junction (TJ)-related molecules, and endoplasmic reticulum (ER)-stress-related factors. ATRA significantly inhibited the TGF-β2-induced increase in the TEER values and FITC dextran permeability of the 2D monolayers, while an ATRA monotreatment induced similar effects as TGF-β2. A real-time metabolic analysis revealed that ATRA significantly inhibited the TGF-β2-induced shift in metabolic reserve from mitochondrial oxidative phosphorylation to glycolysis in 2D HTM cells, whereas ATRA alone did not induce significant metabolic changes. In contrast, ATRA induced the formation of substantially downsized and softer 3D spheroids in the absence and presence of TGF-β2. The different effects induced by ATRA toward 2D and 3D HTM cells were also supported by the qPCR analysis of several proteins as above. The findings reported here indicate that ATRA may induce synergistic and beneficial effects on TGF-β2-treated 2D- and 3D-cultured HTM cells; those effects varied significantly between the 2D and 3D cultures.

Effectiveness of Green Synthesis of Silver/Kaolinite Nanocomposite Using Quercus infectoria Galls Aqueous Extract and Its Chitosan-Capped Derivative on the Healing of Infected Wound

Kaolinite nanocomposites (NCs) could be utilized as agents for wound healing owing to their efficiency and low toxicity. The present study was conducted to synthesize a novel silver/kaolinite NCs (Ag/Kaol NCs) and investigate their chitosan derivation (Ag/Kaol/Chit NCs) using oak extract. XRD, SEM, EDX, FT-IR, and DLS were employed for the investigation of structural and physio-chemical properties of the synthesized NCs. The obtained results revealed that synthesized Ag/Kaol NCs were mesoporous and spherical with sizes ranging from 7-11 nm. They also demonstrated successful synthesis between silver and kaolinite using the extract. Cytotoxicity and in vitro antibacterial activity were also investigated. The clinical effects of ointments containing the NCs for improving wound healing were studied on the wound area, total bacterial count, histological parameters, and protein expression of some genes. Nanocomposites were safe up to 0.50 mg/mL. The results of in vivo and in vitro antibacterial activity showed that Ag/Kaol NCs, were of antibacterial activity ( ). The results of antioxidant activity indicated that Ag/Kaol NCs have antioxidant structures. Our findings concerning molecular mechanism implied that Ag/Kaol/Chit increased the expression of Wnt/ β -catenin and collagen ( ). In sum, Ag/Kaol/Chit showed antibacterial activity and improved wound healing by decreasing the inflammation and promoting the proliferative phase. The novel NCs showed wound healing properties by decreasing inflammation and total bacterial count and increasing proliferative phase. The application of Ag/Kaol/Chit was suggested as a green agent for improving infected wound healing.

Inhibition of TGF-β2-induced migration and epithelial-mesenchymal transition in ARPE-19 by sulforaphane

AIM

To investigate the effects of sulforaphane (SFN) on transforming growth factor (TGF)-β2 stimulated migration and epithelial-mesenchymal transition (EMT) in ARPE-19 cells.

METHODS

ARPE-19 cells were cultured in the presence or absence of SFN or TGF-β2. SFN toxicity was assessed by performing a lactate dehydrogenase assay (LDH) and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays, and cell migration was evaluated by Transwell migration assay. Actin stress fiber formation in ARPE-19 cells was determined using immunofluorescence analysis. Immunoblotting analysis was used to determine fibronectin and α-smooth muscle actin expressions along with the degree of Smad and Akt phosphorylation.

RESULTS

SFN inhibited ARPE-19 migration. Additionally, SFN attenuated TGF-β2-induced appearance of actin stress fibers as well as fibronectin and α-smooth muscle actin expressions in these cells. SFN also hindered the TGF-β2-stimulated phosphorylation of Smad2, Smad3, and Akt. SFN showed no cytotoxicity towards ARPE-19 cells.

CONCLUSION

SFN inhibits TGF-β2-stimulated migration and EMT in ARPE-19 cells, probably by preventing the establishment of actin stress fibers and Akt and Smad2/3 signaling.

Changes in the expression levels of elastic fibres in yak lungs at different growth stages

BACKGROUND

Yaks have a strong adaptability to the plateau environment, which can be attributed to the effective oxygen utilization rate of their lung tissue. Elastic fibre confers an important adaptive structure to the alveolar tissues in yaks. However, little research has been focused on the structural development of lung tissues and the expression levels of elastic fibres in yaks after birth. Therefore, this study aimed to investigate the morphological changes of elastic fibers and expression profiles of fibre-formation genes in yak lungs at different growth stages and the relationship between these changes and plateau adaptation.

RESULTS

Histological staining was employed to observe the morphological changes in the lung tissue structure of yaks at four different ages: 1 day old, 30 days old, 180 days old and adult. There was no significant difference in the area of a single alveolus between the 1-day-old and 30-day-old groups (P-value > 0.05). However, the single alveolar area was gradually increased with an increase in age (P-value < 0.05). Elastic fibre staining revealed that the amount of elastic fibres in alveolar tissue was increased significantly from the ages of 30 days to 180 days (P-value < 0.05) and stabilized during the adult stage. Transcriptome analysis indicated that the highest levels of differentially expressed genes were found between 30 days of age and 180 days of age. KEGG analysis showed that PI3K-Akt signalling pathway and MAPK pathway, which are involved in fibre formation, accounted for the largest proportion of differentially expressed genes between 30 days of age and 180 days of age. The expression levels of 36 genes related to elastic fibre formation and collagen fibre formation were also analysed, and most of these genes were highly expressed in 30-day-old and 180-day-old yaks.

CONCLUSIONS

The content of elastic fibres in the alveolar tissue of yaks increases significantly after birth, but this change occurs only from 30 days of age to 180 days of age. Our study indicates that elastic fibres can improve the efficiency of oxygen utilization in yaks under harsh environmental conditions.

AP-2α Regulates S-Phase and Is a Marker for Sensitivity to PI3K Inhibitor Buparlisib in Colon Cancer

Activating protein 2 alpha (AP-2α; encoded by TFAP2A) functions as a tumor suppressor and influences response to therapy in several cancer types. We aimed to characterize regulation of the transcriptome by AP-2α in colon cancer. CRISPR-Cas9 and short hairpin RNA were used to eliminate TFAP2A expression in HCT116 and a panel of colon cancer cell lines. AP-2α target genes were identified with RNA sequencing and chromatin immunoprecipitation sequencing. Effects on cell cycle were characterized in cells synchronized with aphidicolin and analyzed by FACS and Premo FUCCI. Effects on invasion and tumorigenesis were determined by invasion assay, growth of xenografts, and phosphorylated histone H3 (PHH3). Knockout of TFAP2A induced significant alterations in the transcriptome including repression of TGM2, identified as a primary gene target of AP-2α. Loss of AP-2α delayed progression through S-phase into G₂-M and decreased phosphorylation of AKT, effects that were mediated through regulation of TGM2. Buparlisib (BKM120) repressed in vitro invasiveness of HCT116 and a panel of colon cancer cell lines; however, loss of AP-2α induced resistance to buparlisib. Similarly, buparlisib repressed PHH3 and growth of tumor xenografts and increased overall survival of tumor-bearing mice, whereas, loss of AP-2α induced resistance to the effect of PI3K inhibition. Loss of AP-2α in colon cancer leads to prolonged S-phase through altered activation of AKT leading to resistance to the PI3K inhibitor, Buparlisib. The findings demonstrate an important role for AP-2α in regulating progression through the cell cycle and indicates that AP-2α is a marker for response to PI3K inhibitors. IMPLICATIONS: AP-2α regulated cell cycle through the PI3K cascade and activation of AKT mediated through TGM2. AP-2α induced sensitivity to Buparlisib/BKM120, indicating that AP-2α is a biomarker predictive of response to PI3K inhibitors.

Identification of key genes and pathways in scleral extracellular matrix remodeling in glaucoma: Potential therapeutic agents discovered using bioinformatics analysis

Background: Glaucoma is a leading cause of irreversible blindness. Remodeling of the scleral extracellular matrix (ECM) plays an important role in the development of glaucoma. The aim of this study was to identify the key genes and pathways for the ECM remodeling of sclera in glaucoma by bioinformatics analysis and to explore potential therapeutic agents for glaucoma management. Methods: Genes associated with glaucoma, sclera and ECM remodeling were detected using the text mining tool pubmed2ensembl, and assigned Gene Ontology (GO) biological process terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways using the GeneCodis program. A protein-protein interaction (PPI) network was constructed by STRING and visualized in Cytoscape, module analysis was performed using the Molecular Complex Detection (MCODE) plugin, and GO and KEGG analyses of the gene modules were performed using the Database of Annotation, Visualization and Integrated Discovery (DAVID) platform. The genes that clustered in the significant module were selected as core genes, and functions and pathways of the core genes were visualized using ClueGO and CluePedia. Lastly, the drug-gene interaction database was used to explore drug-gene interactions of the core genes to find drug candidates for glaucoma. Results: We identified 125 genes common to "Glaucoma", "Sclera", and "ECM remodeling" by text mining. Gene functional enrichment analysis yielded 30 enriched GO terms and 20 associated KEGG pathways. A PPI network that included 60 nodes with 249 edges was constructed, and three gene modules were obtained using the MCODE. We selected 13 genes that clustered in module 1 as core candidate genes that were associated mainly with ECM degradation and cell proliferation and division. The HIF-1 signaling pathway, FOXO signaling pathway, PI3K-Akt signaling pathway and TGFB signaling pathway were found to be enriched. We found that 11 of the 13 selected genes could be targeted by 26 existing drugs. Conclusions: The results showed that VEGFA, TGFB1, TGFB2, TGFB3, IGF2, IGF1, EGF, FN1, KNG1, TIMP1, SERPINE1, THBS1, and VWF were potential key genes involved to scleral ECM remodeling. Furthermore, 26 drugs were identified as potential therapeutic agents for glaucoma treatment and management.

The Clinical Significance of PPEF1 as a Promising Biomarker and Its Potential Mechanism in Breast Cancer

Background

Breast cancer (BC) is the leading cause of malignancy death in females worldwide. While intense efforts have been made to elucidate the pathogeny, the molecular mechanism of BC remains elusive. Thus, this study aimed to investigate the role of PPEF1 in the progression of BC and further explore the better clinical significance.

Methods

The diagnostic and prognostic values of elevated PPEF1 expression in BC were unveiled via public databases analysis. In addition, Gene Ontology (GO), Gene Set Enrichment Analysis (GSEA) and Protein–protein interaction (PPI) analysis were performed to explore the potential functions and molecular mechanisms of PPEF1 in BC progression. Experimentally, transwell and CCK-8 assays were carried out to estimate the effects of PPEF1 on the BC metastasis. Meanwhile, the differential expressions of PPEF1 in paraffin-embedded tissues and serum samples were, respectively, analyzed by Immunohistochemical (IHC) analysis and enzyme-linked immunosorbent assay (ELISA) kit.

Results

The transcriptional levels of PPEF1 were higher in BC than in normal breast tissues or adjacent normal tissues. Moreover, survival analysis revealed that higher PPEF1 expression was negatively associated with overall survival (OS), all events-free (AE-free) and metastatic recurrence-free (MR-free) survival, and further was an independent risk factor of unfavorable prognosis in BC patients. Additionally, the present study provided the first evidence that PPEF1 participated in multiple biological processes and underly signaling pathways involving in tumorigenesis and development of BC. Furthermore, PPEF1 promotes the BC progression and can be used as a noninvasive diagnostic marker. Noteworthy, the combined determination of serum PPEF1 and traditional tumor markers can enhance diagnostic accuracy thus is of vital importance in the early diagnosis of BC.

Conclusion

PPEF1 exerted a tumorigenic role and involved in molecular mechanism of tumorigenesis in BC which served as a promising biomarker for prognosis and diagnosis.