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PUBLIC RELEASE DATE:
18-Mar-2014

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Contact: Corinne Williams
press_releases@the-jci.org
Journal of Clinical Investigation

JCI online ahead of print table of contents for March 18, 2014

Cardiac conduction altered by intragenic enhancer

Genome-wide association studies (GWAS) have determined a surprising link between dysfunctional cardiac conduction and variants within SCN10A, which encodes nociceptor-associated sodium-gated ion channel subunit NaV1.8. Follow-up functional studies targeting NaV1.8 revealed only a minor contribution to cardiac physiology; therefore, it was unclear how SCN10A mutations promoted the development of cardiac conduction disease. In this issue of the Journal of Clinical Investigation, the research groups of Vincent Christoffels, Marcelo Nobrega, Phil Barnett, and Ivan Moskowitz teamed up and have now revealed that a transcriptional enhancer within SCN10A is required for cardiac expression of SCN5A, encoding the sodium-gated ion channel subunit NaV1.5, which is critical for cardiac conduction. In humans, a variant in the enhancer within SCN10A was associated with slowed conduction, Brugada syndrome, and reduced SCN5A transcription. In the accompanying Commentary, David Park and Glenn Fishman of the New York School of Medicine discuss how this study highlights the importance of functional studies to distinguish between coding and non-coding functions of genomic regions identified by GWAS.

TITLE: A common genetic variant within SCN10A modulates cardiac SCN5A expression

AUTHOR CONTACT: Ivan Moskowitz
The University of Chicago, Chicago, IL, USA
Phone: 773 834 0462; Fax: 773 834 2132; E-mail: imoskowitz@peds.bsd.uchicago.edu

View this article at: http://www.jci.org/articles/view/73140

ACCOMPANYING COMMENTARY

TITLE: Nav-igating through a complex landscape: SCN10A and cardiac conduction

AUTHOR CONTACT: Glenn I Fishman
NYU School of Medicine, New York, NY, USA
Phone: 212-263-3967; Fax: 212-263-3972; E-mail: glenn.fishman@med.nyu.edu

View this article at: http://www.jci.org/articles/view/75240


Inflammatory feedback loop promotes colorectal cancer metastasis

Induction of the epithelial-mesenchymal transition (EMT) in cancer cells is associated with an increased capacity to invade into surrounding tissue and migrate to distant sites. The tumor-specific factors that drive EMT aren't completely understood; however, evidence implicates inflammation in this process. In this issue of the Journal of Clinical Investigation, a team led by Heiko Hermeking at Ludwigs-Maximilians University determined that exposure of human colorectal cancer cells to the proinflammatory cytokine IL-6 activates the oncogenic transcription factor STAT3, which represses the gene encoding microRNA-34a (miR-34a) and promotes mesenchymal phenotypes. The IL-6 receptor (IL-6R) was identified as a direct target of miR-34a, defining an IL-6R/STAT3/miR-34a feedback loop that promotes EMT, invasion, and metastasis. Activation of p53, which induces miR-34a, decreased IL-6-dependent invasion and migration via reduced IL-6R expression, while loss of miR-34a in a murine model of colitis-associated cancer resulted in enhanced. In an accompanying Commentary, Raghu Kalluri and colleagues of the University of Texas MD Anderson Cancer Center discuss the role of tumor microenvironment in promoting EMT and metastasis.

TITLE: IL-6R/STAT3/miR-34a feedback loop promotes EMT-mediated colorectal cancer invasion and metastasis

AUTHOR CONTACT: Heiko Hermeking
Ludwigs-Maximilians University, Munich, , DEU
Phone: 011-49-89-2180-73685; Fax: 011-49-89-2180-73697; E-mail: Heiko.Hermeking@med.uni-muenchen.de

View this article at: http://www.jci.org/articles/view/73531

ACCOMPANYING COMMENTARY TITLE: Microenvironment-dependent cues trigger miRNA-regulated feedback loop to facilitate the EMT/MET switch

AUTHOR CONTACT: Raghu Kalluri
University of Texas MD Anderson Cancer Center, Houston, TX, USA
Phone: 713-792-8586; E-mail: rkalluri@mdanderson.org

View this article at: http://www.jci.org/articles/view/75239?key=e516522eb60efe2d4b40


Insulin resistance in bone disrupts whole-body glucose homeostasis

Insulin signaling in osteoblasts mediates the activation of osteocalcin, which promotes insulin secretion in the pancreas and insulin sensitivity in other tissues. It is unknown if insulin resistance develops in bone in response to a high fat diet (HFD) and contributes to the disruption of glucose metabolism associated with the development of type 2 diabetes. In thie issue of the Journal of Clinical Investigation, Gerard Karsenty and colleagues of Columbia University determined that insulin resistance does develop in osteoblasts of mice fed a HFD and that this insulin resistance in bone cells contribute to the development of whole-body glucose intolerance through decreased circulation of active osteocalcin. Osteoblast-specific insulin resistance resulted, in part, from increased ubiquitination and degradation of the insulin receptor in response to saturated fatty acids. In the accompanying Commentary, Ryan Riddle and Thomas Clemens of Johns Hopkins University indicate that understanding the interplay between the skeletal system and whole-body metabolism will be beneficial for a wide range of metabolic diseases.

TITLE: Bone-specific insulin resistance disrupts whole-body glucose homeostasis via decreased osteocalcin activation

AUTHOR CONTACT: Gerard Karsenty
Columbia University, New York, NY, USA
Phone: 212 305 4011; E-mail: gk2172@columbia.edu

View this article at: http://www.jci.org/articles/view/72323

ACCOMPANYING COMMENTARY TITLE: Insulin, osteoblasts, and energy metabolism: why bone counts calories

AUTHOR CONTACT: Thomas Clemens
Center for Musculoskeletal Research, John Hopkins, Baltimore, MD, USA
Phone: 410.955.3245; E-mail: tclemen5@jhmi.edu

View this article at: http://www.jci.org/articles/view/75554


Pathogenic interactions between platelets and neutrophils are mediated by AKT2

Pathological interactions between blood cells promote thrombo-inflammatory disease and result in complications such as vaso-occlusion during atherothrombosis, inflammation, and ischemia. Activated platelets, leukocytes and endothelial cells all contribute to the development of vaso-occlusion: though how interactions between these cell types are regulated is poorly understood. In this issue of the Journal of Clinical Investigation, Jaehyung Cho and colleagues at the University of Illinois determined that the serine/threonine kinase AKT2 was required for heterotypic aggregation of activated platelets, neutrophils and endothelial cells during TNF-α-induced vascular inflammation. In neutrophils, AKT2 phosphorylation activated and resulted in membrane translocation of αMβ2 integrin, which promoted cell-cell attachment. Neutrophils and platelets from patients with sickle cell disease (SCD) had increased levels of AKT phosphorylation, and specific inhibition of AKT2 diminished aggregation of these patients' cells. In SCD mice, targeting AKT2 reduced platelet-neutrophil aggregation and improved blood flow rates. In a companion Commentary, Gregory Vercellotti and John Belcher of the University of Minnesota discuss the complicated etiology of SCD-associated vaso-occlusion.

TITLE: Neutrophil AKT2 regulates heterotypic cell-cell interactions during vascular inflammation

AUTHOR CONTACT: Jaehyung Cho
University of Illinois at Chicago, Chicago, IL, USA
Phone: 312-355-5923; E-mail: thromres@uic.edu

View this article at: http://www.jci.org/articles/view/72305?key=ab5b2ca850b1530e92dd

ACCOMPANYING COMMENTARY TITLE: Not simply misshapen red cells: multimolecular and cellular events in sickle vaso-occlusion

AUTHOR CONTACT: Gregory M Vercellotti
University of Minnesota, Minneapolis, MN, USA
Phone: 612 626 3757; Fax: 612 625 6919; E-mail: verce001@umn.edu

View this article at: http://www.jci.org/articles/view/75238


ALSO IN THIS ISSUE:

CLINICAL MEDICINE

TITLE: Sympathetic activity–associated periodic repolarization dynamics predict mortality following myocardial infarction

AUTHOR CONTACT: Axel Bauer
Eberhard Karls University, Tübingen, Tübingen, , DEU
Phone: + 49.7071.29.82922; E-mail: bauer@thebiosignals.org

View this article at: http://www.jci.org/articles/view/70085

STEM CELLS

TITLE: Human muscle–derived stem/progenitor cells promote functional murine peripheral nerve regeneration

AUTHOR CONTACT: Johnny Huard
University of Pittsburgh, Pittsburgh, PA, USA
Phone: 412-648-2798; Fax: 412-648-4066; E-mail: jhuard@pitt.edu

View this article at: http://www.jci.org/articles/view/44071

ONCOLOGY

TITLE: Tumor endothelial marker 1–specific DNA vaccination targets tumor vasculature

AUTHOR CONTACT: Andrea Facciabene
Ovarian Cancer Research Center, Philadelphya, PA, USA
Phone: 215-746-7071; Fax: 2155735129; E-mail: facciabe@mail.med.upenn.edu

View this article at: http://www.jci.org/articles/view/67382

NEPHROLOGY

TITLE: Podocyte-specific RAP1GAP expression contributes to focal segmental glomerulosclerosis–associated glomerular injury

AUTHOR CONTACT: Lewis Kaufman
Mount Sinai School of Medicine, New York, NY, USA
Phone: 646 245-2294; Fax: 212 987-0389; E-mail: lewis.kaufman@mssm.edu

View this article at: http://www.jci.org/articles/view/67846

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