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Full-Text Articles in Medicine and Health Sciences

Cd4+ Regulatory T Cells Require Ctla-4 For The Maintenance Of Systemic Tolerance, Randall Friedline, David Brown, Hai Nguyen, Hardy Kornfeld, Jinhee Lee, Yi Zhang, Mark Appleby, Sandy Der, Joonsoo Kang, Cynthia Chambers Dec 2015

Cd4+ Regulatory T Cells Require Ctla-4 For The Maintenance Of Systemic Tolerance, Randall Friedline, David Brown, Hai Nguyen, Hardy Kornfeld, Jinhee Lee, Yi Zhang, Mark Appleby, Sandy Der, Joonsoo Kang, Cynthia Chambers

David C. Brown

Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a critical role in negatively regulating T cell responses and has also been implicated in the development and function of natural FOXP3(+) regulatory T cells. CTLA-4-deficient mice develop fatal, early onset lymphoproliferative disease. However, chimeric mice containing both CTLA-4-deficient and -sufficient bone marrow (BM)-derived cells do not develop disease, indicating that CTLA-4 can act in trans to maintain T cell self-tolerance. Using genetically mixed blastocyst and BM chimaeras as well as in vivo T cell transfer systems, we demonstrate that in vivo regulation of Ctla4(-/-) T cells in trans by CTLA-4-sufficient T cells is …


Defining Behavioral And Molecular Differences Between Summer And Migratory Monarch Butterflies, Haisun Zhu, Robert Gegear, Amy Casselman, Sriramana Kanginakudru, Steven Reppert Dec 2015

Defining Behavioral And Molecular Differences Between Summer And Migratory Monarch Butterflies, Haisun Zhu, Robert Gegear, Amy Casselman, Sriramana Kanginakudru, Steven Reppert

Robert J. Gegear

BACKGROUND: In the fall, Eastern North American monarch butterflies (Danaus plexippus) undergo a magnificent long-range migration. In contrast to spring and summer butterflies, fall migrants are juvenile hormone deficient, which leads to reproductive arrest and increased longevity. Migrants also use a time-compensated sun compass to help them navigate in the south/southwesterly direction en route for Mexico. Central issues in this area are defining the relationship between juvenile hormone status and oriented flight, critical features that differentiate summer monarchs from fall migrants, and identifying molecular correlates of behavioral state. RESULTS: Here we show that increasing juvenile hormone activity to induce summer-like …


The Fly Camta Transcription Factor Potentiates Deactivation Of Rhodopsin, A G Protein-Coupled Light Receptor, Junhai Han, Ping Gong, Keith Reddig, Mirna Mitra, Peiyi Guo, Hong-Sheng Li Jul 2015

The Fly Camta Transcription Factor Potentiates Deactivation Of Rhodopsin, A G Protein-Coupled Light Receptor, Junhai Han, Ping Gong, Keith Reddig, Mirna Mitra, Peiyi Guo, Hong-Sheng Li

Peiyi Guo

Control of membrane-receptor activity is required not only for the accuracy of sensory responses, but also to protect cells from excitotoxicity. Here we report the isolation of two noncomplementary fly mutants with slow termination of photoresponses. Genetic and electrophysiological analyses of the mutants revealed a defect in the deactivation of rhodopsin, a visual G protein-coupled receptor (GPCR). The mutant gene was identified as the calmodulin-binding transcription activator (dCAMTA). The known rhodopsin regulator Arr2 does not mediate this visual function of dCAMTA. A genome-wide screen identified five dCAMTA target genes. Of these, overexpression of the F box gene dFbxl4 rescued the …


Post-Transcriptional Regulation Of Myelin Formation, Nancy Zearfoss, Brian Farley, Sean Ryder May 2015

Post-Transcriptional Regulation Of Myelin Formation, Nancy Zearfoss, Brian Farley, Sean Ryder

Sean P. Ryder

Myelin is a specialized structure of the nervous system that both enhances electrical conductance and protects neurons from degeneration. In the central nervous system, extensively polarized oligodendrocytes form myelin by wrapping cellular processes in a spiral pattern around neuronal axons. Myelin formation requires the oligodendrocyte to regulate gene expression in response to changes in its extracellular environment. Because these changes occur at a distance from the cell body, post-transcriptional control of gene expression allows the cell to fine-tune its response. Here, we review the RNA-binding proteins that control myelin formation in the brain, highlighting the molecular mechanisms by which they …


The Tissue-Specific Nuclear Matrix Protein, Nmp-2, Is A Member Of The Aml/Cbf/Pebp2/Runt Domain Transcription Factor Family: Interactions With The Osteocalcin Gene Promoter, Harold Merriman, Andre Van Wijnen, Scott Hiebert, Joseph Bidwell, Edward Fey, Jane Lian, Janet Stein, Gary Stein Feb 2015

The Tissue-Specific Nuclear Matrix Protein, Nmp-2, Is A Member Of The Aml/Cbf/Pebp2/Runt Domain Transcription Factor Family: Interactions With The Osteocalcin Gene Promoter, Harold Merriman, Andre Van Wijnen, Scott Hiebert, Joseph Bidwell, Edward Fey, Jane Lian, Janet Stein, Gary Stein

Harold L. Merriman

The nuclear matrix protein, NMP-2, was originally identified as an osteoblast-specific DNA-binding complex localized exclusively to the nuclear matrix. NMP-2 was shown to recognize two binding sites, site A (nt-605 to -599) and site B (nt -441 to -435), in the rat bone-specific osteocalcin gene promoter. This study shows that the NMP-2 binding sites A and B as well as a third NMP-2 binding site (nt -135 to -130) constitute a consensus sequence, ATGCTGGT, and represent an AML-1 recognition motif. AML-1 is a member of the AML transcription factor family which is associated with acute myelogenous leukemia and binds to …


Amphetamine-Induced Decreases In Dopamine Transporter Surface Expression Are Protein Kinase C-Independent, Ekaterina Boudanova, Deanna Navaroli, Haley Melikian Feb 2015

Amphetamine-Induced Decreases In Dopamine Transporter Surface Expression Are Protein Kinase C-Independent, Ekaterina Boudanova, Deanna Navaroli, Haley Melikian

Haley Melikian

Amphetamine (AMPH) is a potent dopamine (DA) transporter (DAT) inhibitor that markedly increases extracellular DA levels. In addition to its actions as a DAT antagonist, acute AMPH exposure induces DAT losses from the plasma membrane, implicating transporter-specific membrane trafficking in amphetamine's actions. Despite reports that AMPH modulates DAT surface expression, the trafficking mechanisms leading to this effect are currently not defined. We recently reported that DAT residues 587-596 play an integral role in constitutive and protein kinase C (PKC)-accelerated DAT internalization. In the current study, we tested whether the structural determinants required for PKC-stimulated DAT internalization are necessary for AMPH-induced …