Life Sciences Commons^™

Chop Mediates Endoplasmic Reticulum Stress-Induced Apoptosis In Gimap5-Deficient T Cells, Steven Pino, Bryan O'Sullivan-Murphy, Erich Lidstone, Chaoxing Yang, Kathryn Lipson, Agata Jurczyk, Philip Diiorio, Michael Brehm, John Mordes, Dale Greiner, Aldo Rossini, Rita Bortell

Philip J diIorio Jr

Gimap5 (GTPase of the immunity-associated protein 5) has been linked to the regulation of T cell survival, and polymorphisms in the human GIMAP5 gene associate with autoimmune disorders. The BioBreeding diabetes-prone (BBDP) rat has a mutation in the Gimap5 gene that leads to spontaneous apoptosis of peripheral T cells by an unknown mechanism. Because Gimap5 localizes to the endoplasmic reticulum (ER), we hypothesized that absence of functional Gimap5 protein initiates T cell death through disruptions in ER homeostasis. We observed increases in ER stress-associated chaperones in T cells but not thymocytes or B cells from Gimap5(-/-) BBDP rats. We then …

Failure Of Alpha-Galactosylceramide To Prevent Diabetes In Virus-Inducible Models Of Type 1 Diabetes In The Rat, Prerna Chopra, Philip Diiorio, Steven Pino, S. Brian Wilson, Nancy Phillips, John Mordes, Aldo Rossini, Dale Greiner, Leonard Shultz, Rita Bortell

Philip J diIorio Jr

BACKGROUND: Alpha-galactosylceramide (alpha-GalCer) is an invariant natural killer T (iNKT) cell ligand that prevents type 1 diabetes in NOD mice. However, alpha-GalCer can activate or suppress immune responses, raising concern about its potential use in human diabetes.

MATERIALS AND METHODS: To evaluate this therapeutic issue further, BBDR and LEW.1WR1 rats were treated with Kilham rat virus (KRV) plus polyinosinic-polycytidylic acid, with or without alpha-GalCer, and followed for onset of diabetes.

RESULTS: alpha-GalCer did not prevent diabetes in inducible rat models. To investigate this discrepancy, we analyzed iNKT cell function. Splenocytes stimulated with alpha-GalCer produced similar levels of IFNgamma in all …

Tale-Family Homeodomain Proteins Regulate Endodermal Sonic Hedgehog Expression And Pattern The Anterior Endoderm, Philip Diiorio, Kristen Alexa, Seong-Kyu Choe, Letitiah Etheridge, Charles Sagerstrom

Philip J diIorio Jr

sonic hedgehog (shh) is expressed in anterior endoderm, where it is required to repress pancreas gene expression and to pattern the endoderm, but the pathway controlling endodermal shh expression is unclear. We find that expression of meis3, a TALE class homeodomain gene, coincides with shh expression in the endoderm of zebrafish embryos. Using a dominant negative construct or anti-sense morpholino oligos (MOs) to disrupt meis3 function, we observe ectopic insulin expression in anterior endoderm. This phenotype is also observed when meis3 MOs are targeted to the endoderm, suggesting that meis3 acts within the endoderm to restrict insulin expression. We also …

A Zebrafish Unc-45-Related Gene Expressed During Muscle Development, Letitiah Etheridge, Philip Diiorio, Charles Sagerstrom

Philip J diIorio Jr

We report the isolation and expression pattern of zebrafish unc45r, a gene related to Caenorhabditis elegans unc-45. UNC-45 is a muscle-specific protein thought to interact with myosin and promote the assembly of muscle thick filaments during C. elegans development. Zebrafish Unc45r shares sequence features with C. elegans UNC-45, including three tetratricopeptide repeats and a CRO1/She4p homology domain. unc45r is expressed in mesoderm adjacent to the dorsal midline during late gastrula stages and is coexpressed with muscle specific genes in somitic mesoderm during development of trunk skeletal muscle. unc45r is also expressed in cranial skeletal muscle as well as in cardiac …