Adipose tissue is an endocrine organ with strong proinflammatory capacity; however, the role of this tissue in highly pathogenic virus infections has not been extensively examined. We show that mice infected with a mouse-adapted Ebola Virus (EBOV) exhibit increasing levels of viral transcript in visceral and subcutaneous adipose tissue over the course of infection. Human adipocytes were found to be susceptible to EBOV.
View Article and Find Full Text PDFMutations in BBS6 cause two clinically distinct syndromes, Bardet-Biedl syndrome (BBS), a syndrome caused by defects in cilia transport and function, as well as McKusick-Kaufman syndrome, a genetic disorder characterized by congenital heart defects. Congenital heart defects are rare in BBS, and McKusick-Kaufman syndrome patients do not develop retinitis pigmentosa. Therefore, the McKusick-Kaufman syndrome allele may highlight cellular functions of BBS6 distinct from the presently understood functions in the cilia.
View Article and Find Full Text PDFEstablishment of the left-right axis is essential for normal organ morphogenesis and function. Ca(2+) signaling and cilia function in the zebrafish Kuppfer's Vesicle (KV) have been implicated in laterality. Here we describe an endogenous Ca(2+) release event in the region of the KV precursors (dorsal forerunner cells, DFCs), prior to KV and cilia formation.
View Article and Find Full Text PDFThe node, or its zebrafish equivalent, Kupffers Vesicle (KV), is thought to generate laterality cues through cilia-dependent signaling. An interaction between Nodal ligands and Nodal antagonists around the node/KV is also required. Here we investigate whether loss of Brachyury/Notail or Tbx16/Spadetail disrupts the balance of Nodal ligands (Southpaw) and antagonists (Charon) around Kupffers Vesicle.
View Article and Find Full Text PDFHuntington's disease (HD) and other polyglutamine (polyQ) neurodegenerative diseases are characterized by neuronal accumulation of the disease protein, suggesting that the cellular ability to handle abnormal proteins is compromised. As both a cochaperone and ubiquitin ligase, the C-terminal Hsp70 (heat shock protein 70)-interacting protein (CHIP) links the two major arms of protein quality control, molecular chaperones, and the ubiquitin-proteasome system. Here, we demonstrate that CHIP suppresses polyQ aggregation and toxicity in transfected cell lines, primary neurons, and a novel zebrafish model of disease.
View Article and Find Full Text PDFWe have isolated a novel gene, charon, that encodes a member of the Cerberus/Dan family of secreted factors. In zebrafish, Fugu and flounder, charon is expressed in regions embracing Kupffer's vesicle, which is considered to be the teleost fish equivalent to the region of the mouse definitive node that is required for left-right (L/R) patterning. Misexpression of Charon elicited phenotypes similar to those of mutant embryos defective in Nodal signaling or embryos overexpressing Antivin(Atv)/Lefty1, an inhibitor for Nodal and Activin.
View Article and Find Full Text PDFTrends Cardiovasc Med
February 2004
The establishment of the left-right (LR) asymmetry of the zebrafish heart involves at least two discrete events: cardiac jogging and cardiac looping. The nodal-related gene southpaw is required for both aspects of heart LR asymmetry as well as for LR patterning of other visceral organs. Reductions in southpaw activity abolish the normal LR biases of jogging and looping and uncouple the normal correlation between jogging and looping polarities.
View Article and Find Full Text PDFMany vertebrate organs adopt asymmetric positions with respect to the midline, but little is known about the cellular changes and tissue movements that occur downstream of left-right gene expression to produce this asymmetry. Here, we provide evidence that the looping of the zebrafish gut results from the asymmetric migration of the neighboring lateral plate mesoderm (LPM). Mutations that disrupt the epithelial structure of the LPM perturb this asymmetric migration and inhibit gut looping.
View Article and Find Full Text PDFWe have identified and characterized a new zebrafish gene, southpaw, that is required for visceral and diencephalic left-right asymmetry. southpaw encodes a new member of the nodal-related class of proteins, a subfamily within the transforming growth factor beta superfamily of secreted factors. southpaw is expressed bilaterally in paraxial mesoderm precursors and then within the left lateral plate mesoderm.
View Article and Find Full Text PDFNodal signalling is essential for many developmental events during vertebrate development, including the establishment of left-right asymmetry, of dorsoventral axis of the central nervous system, and endoderm and mesoderm formation. The zebrafish TGFbeta-related type I receptor, TARAM-A (Tar), is expressed in the prospective mesendodermal territory and, when activated, can transfate early blastomeres into endoderm, suggesting that Nodal and Tar may represent similar signalling pathways. We have analysed the functional relationships between those two pathways in zebrafish.
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