Latent Pathways Identification by Microarray Expression Profiles in Thyroid-Associated Ophthalmopathy Patients.

This study aimed to screen potential genes related to thyroid-associated ophthalmopathy (TAO) and get a further understanding about the pathogenesis of this disease. GSE9340 was downloaded from Gene Expression Omnibus, including eight thyroid tissue samples from hyperthyroid patients without TAO and ten ones from hyperthyroid patients with TAO. The differentially expressed genes (DEGs) were identified by the linear models for microarray data package. And their potential functions were predicted by Gene Ontology (GO) and pathway enrichment analyses. Furthermore, protein-protein interaction (PPI) was obtained from the Search Tool for the Retrieval of Interacting Genes database, and the PPI network was visualized with Cytoscape. Then, module analysis was performed by the Molecular Complex Detection analysis. Additionally, the potential pathway interactions were identified by Latent Pathway Identification Analysis. Totally, 511 upregulated and 507 downregulated DEGs in TAO were screened. Some DEGs (e.g., UBE2C) were related to cell cycle, and DEGs encoding proteasome (e.g., PSMA1, PSMC5, PSMC4, and PSMD1) were related to negative regulation of ubiquitin-protein ligase activity. Several upregulated DEGs encoding signal recognition particle (e.g., SRP14, SRP54, and SRP9) were found to be enriched in protein export pathway. Furthermore, some pathways (e.g., ribosome and protein export) had interactions. The DEGs related to cell cycle (e.g., UBE2C), DEGs encoding proteasome (e.g., PSMA1, PSMC5, PSMC4, and PSMD1) and signal recognition particle (e.g., SRP14, SRP54, and SRP9), as well as pathways of ribosome, protein export and retinol metabolism, might play key roles in the development of TAO.

An in vitro comparison study: the effects of fetal bovine serum concentration on retinal progenitor cell multipotentiality.

Retinal progenitor cells (RPCs) are an excellent resource for retinal replacement therapy, because they show enormous potential to differentiate into retinal-specific cell types. While the differentiating influence of serum has long been appreciated, the effects of serum concentration on RPC differentiation into specified retinal neural cells have not been investigated. Using cultured murine RPCs, this study compared the effects of different levels of fetal bovine serum (FBS) (1%, 5%, 10% and 20%) on RPC differentiation in vitro. RPC multipotentiality was assessed by using quantitative polymerase chain reaction (qPCR) to determine the relative expression levels of 10 genes involved in retinal development. In addition, analyses of cell morphology and retinal development-related protein expression were performed using microscopy and immunocytochemistry. The data revealed that 1% FBS-induced cultures preferentially generated rhodopsin- and PKC-α-positive cells. Calbindin and AP2α expression levels were greater in 5% FBS-induced cultures. Brn3a was expressed at similar levels in 1%, 5% and 10% FBS treatment conditions but diminished in 20% FBS conditions. Twenty percent FBS induced more glial fibrillary acid protein (GFAP)-immunoreactive cells corresponding to glia populations. These findings suggest that the concentration of FBS plays an important role in RPC differentiation in vitro. Treatment with low levels of FBS favors differentiation of rhodopsin-positive photoreceptors, interneurons and retinal ganglion cells (RGCs), while high FBS concentrations preferentially induce differentiation of glia cells. These results are expected to facilitate research in the treatment of neurodegenerative retinal diseases.

Insulin-like growth factor 1 promotes the proliferation and adipogenesis of orbital adipose-derived stromal cells in thyroid-associated ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO) is characterised by increased volume of the orbital contents involving adipose tissue, but the factors responsible for stimulation of orbital adipogenesis remain uncertain. Previous studies have shown that insulin-like growth factor 1 (IGF-1) is increased in the orbital fatty connective tissues of patients with TAO. The present study was conducted to investigate the effects of IGF-1 on orbital adipose-derived stromal cells (OADSCs) derived from TAO patients and to identify the signalling mechanisms involved. Our results showed that IGF-1 significantly promoted the cell proliferation and lipid accumulation of TAO OADSCs. The mRNA expression of adipogenic markers (adiponectin, leptin, adipocyte fatty acid binding protein [AP2] and fatty acid synthase [FAS]) was increased in TAO cultures treated with IGF-1. Further research demonstrated that the protein levels of peroxisome proliferator-activated receptor-γ (PPARγ) were up-regulated when OADSCs were treated with IGF-1. We also found that the inhibition of either IGF-1 receptor (IGF-1R) or phosphoinositide 3-kinase (PI3K) activity decreased the levels of IGF-1-stimulated mRNA encoding adiponectin, leptin, AP2, and FAS, as well as PPARγ protein levels. Moreover, the expression of phosphorylated Akt (p-Akt) protein in TAO cells was up-regulated by IGF-1, while a specific PI3K inhibitor (LY294002) or an antibody of IGF-1R blocked this effect. These results indicate that IGF-1 is a pro-proliferative and pro-adipogenic factor in TAO OADSCs. IGF-1 enhances the adipogenesis of TAO OADSCs by up-regulation of PPARγ via the activation of the IGF-1R and PI3K pathways, suggesting that the blocking of IGF-1R or inhibition of PI3K signalling might be a potential novel therapeutic approach to TAO.