Gene Expression Profile of Mesenchymal Stem Cells from Paired Umbilical Cord Units: Cord is Different from Blood

Mesenchymal stem cells (MSC) are multipotent cells which can be obtained from several adult and fetal tissues including human umbilical cord units. We have recently shown that umbilical cord tissue (UC) is richer in MSC than umbilical cord blood (UCB) but their origin and characteristics in blood as compared to the cord remains unknown. Here we compared, for the first time, the exonic protein-coding and intronic noncoding RNA (ncRNA) expression profiles of MSC from match-paired UC and UCB samples, harvested from the same donors, processed simultaneously and under the same culture conditions. The patterns of intronic ncRNA expression in MSC from UC and UCB paired units were highly similar, indicative of their common donor origin. The respective exonic protein-coding transcript expression profiles, however, were significantly different. Hierarchical clustering based on protein-coding expression similarities grouped MSC according to their tissue location rather than original donor. Genes related to systems development, osteogenesis and immune system were expressed at higher levels in UCB, whereas genes related to cell adhesion, morphogenesis, secretion, angiogenesis and neurogenesis were more expressed in UC cells. These molecular differences verified in tissue-specific MSC gene expression may reflect functional activities influenced by distinct niches and should be considered when developing clinical protocols involving MSC from different sources. In addition, these findings reinforce our previous suggestion on the importance of banking the whole umbilical cord unit for research or future therapeutic use.

POLYGLYCOLIC ACID TUBE ASSOCIATED WITH GM1 IN REGENERATION OF PERIPHERAL NERVES

Introduction: Nerve allografting is regarded as a treatment of choice in large neural tissue losses preventing repair by primary anastomosis. In these cases, a synthetic polyglycolic acid tube is an alternative for nerve grafting. On the other hand, several studies have emphasized the importance of neurotrophic factors on neural regeneration, including substances with potential to optimize neural regeneration, especially the GM1, an neurotrophic enhancer factor. Objective: to compare, in rats, the neural regeneration degree using histological analysis, regenerated myelinized axons count, and functional analysis with the use of neurotube and GM1. Methods: This assessment was performed by interposing allograft (group A), polyglycolic acid tube (group B) and polyglycolic acid tube associated to GM1 (group C) on 5-mm sciatic nerve defects. Results: Neuroma formation was found only on group A. Groups A and C showed similar histological patterns, except for the regenerated axons on group C, which were shown to be better organized and myelinized than in group A. Conclusion: on functional recovery, no statistically significant difference was found for the three groups, despite of qualitative and quantitative histological differences found.

Evaluation of Experimental Autoimmune Uveitis in Mice Treated with FTY720

PURPOSE. FTY720 (fingolimod) is an immunomodulatory drug capable of preventing T-cell migration to inflammatory sites by binding to and subsequently downregulating the expression of sphingosine-1 phosphate receptor 1 (S1P(1)) leading in turn to T-cell retention in lymphoid organs. Additional effects of FTY720 by increasing functional activity of regulatory T cells have recently been demonstrated, raising the conversion of conventional T cells into regulatory T cells and affecting the sequestration of regulatory T cells in normal mice. In this study, the action of FTY720 in the ocular autoimmune model in mice was investigated. METHODS. Mice were immunized with 161-180 peptide and pertussis toxin and were treated with 1 mg/kg/d FTY720 by gavage (7-21 days postimmunization [dpi]) or left untreated. Spleen cells, harvested 21 dpi, were cultured and assayed for cytokine production. Draining lymph node, spleen, and eye cells 21 dpi were assayed for quantification of T-cell populations. Disease severity was evaluated by histologic examination of the enucleated eyes at 21 and 49 dpi. In addition, anti-IRBP antibodies were analyzed by ELISA. RESULTS. FTY720 was effective in suppressing the experimental autoimmune uveitis score. Although there was a reduction in the number of eye-infiltrating cells, FTY did not prevent Treg accumulation at this site. FTY720 leads to a significant increase of CD4(+)IFN-gamma(+) and CD4(+)Foxp3(+) cell percentages in lymph nodes, suggesting that this site could be the source of Treg cells found in the eye. CONCLUSIONS. The data showed that treatment in vivo with FTY720 was able to suppress EAU in mice. These results are indicative of the possible therapeutic use of FTY720 in ocular autoimmune processes. (Invest Ophthalmol Vis Sci. 2010;51:2568-2574) DOI:10.1167/iovs.09-4769

The geodiamolide H, derived from Brazilian sponge Geodia corticostylifera, regulates actin cytoskeleton, migration and invasion of breast cancer cells cultured in three-dimensional environment

We are investigating effects of the depsipeptide geodiamolide H, isolated from the Brazilian sponge Geodia corticostylifera, on cancer cell lines grown in 3D environment. As shown previously geodiamolide H disrupts actin cytoskeleton in both sea urchin eggs and breast cancer cell monolayers. We used a normal mammary epithelial cell line MCF 10A that in 3D assay results formation of polarized spheroids. We also used cell lines derived from breast tumors with different degrees of differentiation: MCF7 positive for estrogen receptor and the Hs578T, negative for hormone receptors. Cells were placed on top of Matrigel. Spheroids obtained from these cultures were treated with geodiamolide H. Control and treated samples were analyzed by light and confocal microscopy. Geodiamolide H dramatically affected the poorly differentiated and aggressive Hs578T cell line. The peptide reverted HsS78T malignant phenotype to polarized spheroid-like structures. MCF7 cells treated by geodiamolide H exhibited polarization compared to controls. Geodiamolide H induced striking phenotypic modifications in Hs578T cell line and disruption of actin cytoskeleton. We investigated effects of geodiamolide H on migration and invasion of Hs578T cells. Time-lapse microscopy showed that the peptide inhibited migration of these cells in a dose-dependent manner. Furthermore invasion assays revealed that geodiamolide H induced a 30% decrease on invasive behavior of Hs578T cells. Our results suggest that geodiamolide H inhibits migration and invasion of Hs578T cells probably through modifications in actin cytoskeleton. The fact that normal cell lines were not affected by treatment with geodiamolide H stimulates new studies towards therapeutic use for this peptide.