Project description:The goal of this study was to identify transcriptional changes in SC-beta and SC-endothelial cells pre and post IFN-gamma stimulation. Specifically, to characterize the differential expression of immune cell ligands in these cells with respect to a partial inflammatory stimulus.
Project description:total RNA from mouse (male c57BL/6) spleen labeled with Cy3 vs total RNA from mouse (male c57BL/6) B cells treated with Interferon-beta (IFN beta) labeled with Cy5- time course with repeats Keywords: ordered
Project description:Stem cell-derived β (SC-β) cells are an emerging regenerative therapy to compensate for loss of functional β cell mass in diabetes. Glucose-stimulated insulin secretion in SC-β cells is variable in vitro but stabilizes after transplantation and maturation under the kidney capsule of mice. We identified mechanisms correlated with functional maturation using RNA-sequencing and co-expression network analysis. In vivo maturation enhanced glucose-stimulated but not basal insulin secretion, up-regulated β cell hormones IAPP and ADCYAP1, increased expression of maturation markers MAFA, UCN3, and SIX2, and resolved endocrine identity of incompletely specified polyhormonal cells produced during differentiation. Transplantation promoted calcium signalling, induced exocytotic machinery supporting hormone secretion and improved stimulus-secretion coupling that fine-tunes insulin secretion. Growth hormone signalling emerged as candidate driver of in vivo maturation and was confirmed in vitro. Also, a large co-expression module correlated with HbA1c and was enriched in genes up-regulated during in vivo maturation but down-regulated in hyperglycaemic and palmitate stress conditions, suggesting that transcriptional maturation of SC-β cells in vivo mirrors processes lost in diabetic β cells.
Project description:Islet transplantation for treatment of diabetes is limited by availability of donor islets and requirements for immunosuppression. Stem cell-derived islets might circumvent these issues. SC-islets effectively control glucose metabolism post transplantation, but do not yet achieve full function in vitro with currently published differentiation protocols. We aimed to identify markers of mature subpopulations of SC-β cells by studying transcriptional changes associated with in vivo maturation of SC-β cells using RNA-seq and co-expression network analysis. The β cell-specific hormone islet amyloid polypeptide (IAPP) emerged as the top candidate to be such a marker. IAPP+ cells had more mature β cell gene expression and higher cellular insulin content than IAPP- cells in vitro. IAPP+ INS+ cells were more stable in long-term culture than IAPP- INS+ cells and retained insulin expression after transplantation into mice. Finally, we conducted a small molecule screen to identify compounds that enhance IAPP expression. Aconitine up-regulated IAPP and could help to optimize differentiation protocols.
Project description:Zika virus (ZIKV) is unique among mosquito-borne flaviviruses in its ability to be sexually transmitted. The testes have been implicated as sites of long-term ZIKV replication, and our previous studies have identified Sertoli cells (SC), the nurse cells of the seminiferous epithelium that govern spermatogenesis, as major targets of ZIKV infection. To improve our understanding of the host-ZIKV interaction within human testicular cells, we analyzed ZIKV-induced proteome changes in SC and mixed seminiferous tubule cells (STC) using high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS). We found that ZIKV infection in SC and STC induced distinct IFN-stimulated proteins and impacted pathways and functional networks associated with innate antiviral defense. IFN signaling was the most significantly enriched pathway and MX1 was the most abundant IFN-stimulated protein in both SC and STC. Increased levels of MX1 at later time points of infection coincided with diminished propagation of ZIKV in SC, whereas silencing of MX1 and IFIT1 enhanced peak ZIKV titers in SC. Furthermore, although downstream IFN-I signaling was found to be functional and restricted ZIKV replication in SC, in comparison to A549 cells, SC exhibited dampened expression of IFN-I/III-stimulated genes despite higher levels of virus progeny and IFN-I/III transcripts. Together, this study highlights the IFN-I/III response as a driver of the antiviral state that limits ZIKV infection in SC and suggests that delayed and reduced robustness of innate antiviral defense in SC may contribute to ZIKV persistence in the testes.
Project description:Glioma cells are sensitized to the alkylator temozolomide after exposure to IFN-beta. In glioma-initiating cells (GIC), IFN-beta alone reduces clonogenicity. We investigated differentially expressed genes with or without IFN exposure in either longterm glioma cells or GIC. We used microarrays to investigate differential gene regulation in glioma cells after exposure to either ddH20 or IFN-beta 300 IU/ml at 6 h or 24 h. We used either the longterm cell line LNT-229 or the GIC cell lines GS-2 and GS-9 and exposed them to either IFN-beta 300 IU/ml or ddH20 for 6 h or 24 h.
Project description:We aimed to identify specific biomarkers of IFN-beta bioactivity in order to compare their gene expression induction by type I IFNs with the MxA, and to investigate their potential role in MS pathogenesis. Gene expression microarrays were performed in PBMC from MS patients who developed neutralizing antibodies (NAB) to IFN-beta. Nine genes followed patterns in gene expression over time similar to the MX1 and were selected for further experiments: IFI6, IFI27, IFI44L, IFIT1, HERC5, LY6E, RSAD2, SIGLEC1, and USP18. In vitro experiments revealed specific induction of selected biomarkers by IFN-beta but not IFN-gamma, and several markers, in particular USP18 and HERC5, were significantly induced at lower IFN-beta concentrations and more selective than the MX1 as biomarkers of IFN-beta bioactivity. In addition, USP18 expression was deficient in MS patients compared with healthy controls (p=0.0004). We propose specific biomarkers that may be considered in addition to the MxA to evaluate IFN-beta bioactivity, and to further explore their implication in MS pathogenesis. Number of samples: 32. We analyzed PBMC from 8 patients at baseline and after 3, 12 and 24 months of IFN-beta treatment