Exploring the cause of sudden unexplained death in epilepsy
Dravet syndrome (DS) is a form of infantile-onset, treatment-resistant epilepsy that is caused by a mutation in the gene encoding a voltage-gated sodium channel, SCN1A. DS patients have a 30-fold increased risk of dying from sudden unexplained death in epilepsy (SUDEP) compared to patients with other forms of pediatric-onset epilepsy. In this issue of the Journal of Clinical Investigation, Franck Kalume and colleagues at the University of Washington characterized SUDEP in a mouse model of DS. Observation using video, electroencephalography, and electrocardiography revealed that a prolonged slowing of the heart beat preceded SUDEP in mice. Treatment with with drugs that reduce activity in the parasympathetic nervous system reduced the incidence of SUDEP, suggesting that mortality results from seizure-related parasympathetic hyperactivity. In a companion Attending Physician, Orrin Devinsky and colleagues discuss how these results could relate to SUDEP in human DS patients.
TITLE:
Sudden unexpected death in a mouse model of Dravet Syndrome
AUTHOR CONTACT:
William Catterall
University of Washington, Seattle, WA, USA
Phone: (206) 543-1970; Fax: (206) 685-3822; E-mail: wcatt@uw.edu
View this article at: http://www.jci.org/articles/view/66220?key=bc7ca495798f6f01e8cf
ACCOMPANYING THE ATTENDING PHYSICIAN
TITLE:
Sudden death in epilepsy: Of mice and men
AUTHOR CONTACT:
Orrin Devinsky
New York University Langone Medical Center
Phone: 646-558-0803; E-mail: od4@nyu.edu
View this article at: http://www.jci.org/articles/view/67759?key=77e9caf46a8bc6b89166
Lymphatic vasculature: a cholesterol removal system
Reverse cholesterol transport is a process in which accumulated cholesterol is removed from tissues, including the artery wall, and transported back to the liver for excretion. Little is known about how cholesterol is removed from peripheral tissues, but a better understanding of these mechanisms could help in the development of therapies that treat atherosclerosis and other cholesterol-related disorders. In this issue of the Journal of Clinical Investigation, researchers led by Gwendalyn Randolph and colleagues at Washington University in St. Louis examined the role of the lymphatic system in RCT. The lymphatic system generally mediates transport of large molecules from the area around blood vessels into the blood. Randolph and colleagues tracked RCT in a mouse model of atherosclerosis with normal and impaired lymphatic growth. Mice lacking normal lymphatic growth retained more cholesterol in their aortas, indicating that lymphatic vessels are required for RCT in the aortic wall. These findings suggest that therapies that support lymphatic transport could enhance cholesterol clearance from arteries. In a companion commentary, Carlos Fernandez-Hernando of New York University discusses how such therapies could be used to treat atherosclerotic vascular disease.
TITLE:
Lymphatic vasculature mediates macrophage reverse cholesterol transport in mice
AUTHOR CONTACT:
Gwendalyn J. Randolph
Washington University in St. Louis, Saint Louis, MO, USA
Phone: 314 286 2345; E-mail: grandolph@path.wustl.edu
View this article at: http://www.jci.org/articles/view/63685?key=d3b240337f1e02e4324a
ACCOMPANYING COMMENTARY
TITLE:
Lymphatic vessels clean up your arteries
AUTHOR CONTACT:
Carlos Fernandez-Hernando
New York University School of Medicine, New YorK, NY, USA
Phone: 212-263-9496; E-mail: carlos.fernandez-hernando@nyumc.org
View this article at: http://www.jci.org/articles/view/68657?key=ac89c4e32d2370ab5316
A new therapeutic target in iron overload disorders
Iron is required for multiple cellular functions, including the synthesis of hemoglobin, but a buildup of excess cellular iron can be toxic. Hepcidin is a circulating molecule produced by the liver that triggers the degradation of iron transporters in the intestine and certain immune cells. In response to rising iron stores, increased hepcidin levels lead to reduced iron absorption from the diet. Iron overload can occur due to inherited mutations in this iron homeostasis pathway, or to disorders that lead to ineffective blood cell development, such as β-thalassemia. In this issue of the Journal of Clinical Investigation, Shuling Guo, Carla Casu and colleagues at Weill Cornell Medical College in New York increased hepcidin levels by generating molecules that target a negative regulator of hepcidin production called TMPRSS6. Injection of these molecules improved iron homeostasis and blood cell development in mouse models of iron overload. In the accompanying commentary, Karin Finberg of Duke University how these findings could impact the treatment of patients with β-thalassemia.
TITLE:
Reducing TMPRSS6 ameliorates hemochromatosis and beta-thalassemia in mice
AUTHOR CONTACT:
Stefano Rivella
Weill Cornell Medical College, New York, NY, USA
Phone: 212-746-4941; Fax: 212-746-8423; E-mail: str2010@med.cornell.edu
View this article at: http://www.jci.org/articles/view/66969?key=94b8b0c4a137ae990970
ACCOMPANYING ARTICLE
TITLE:
Striking the target in iron overload disorders
AUTHOR CONTACT:
Karin Finberg
Duke University Medical School, Durham, NC, USA
Phone: +1 919.684.3491; Fax: ; E-mail: karin.finberg@duke.edu
View this article at: http://www.jci.org/articles/view/68889?key=c5c95c5b3a8b1b1152ed
Protein pair promotes skin regeneration
Because skin protects our bodies from pathogens and harsh environmental conditions, it must undego constant renewal. The cells that form the top most layer of the skin, known as cornified keratinocytes, are shed constantly and must be resupplied. Repression of a cellular signaling pathway mediated by ERK proteins is required for differentiation of keratinocytes, but this pathway is hyperactivated in a group of disorders known as RASopathies. In this issue of the Journal of Clinical Investigaiton, researchers led by Kathleen Green at Northwestern University, identified a pair of proteins that function to suppress ERK activation and drive the development of keratinocytes. In skin cells, two proteins, RAS and SHOC2 form a complex that activates ERK. Green and colleagues found that the proteins Erbin and DSG1 disrupt SHOC2/RAS complexes and prevent ERK activation. These findings reveal a previously unknown role for DSG1/Erbin in skin disorders. In a companion commentary, John Stanley of the University of Pennsylvania discusses how these findings contribute to our understanding of how skin is maintained.
TITLE:
Desmoglein-1/Erbin interaction suppresses ERK activation to support epidermal differentiation
AUTHOR CONTACT:
Kathleen J. Green
Professor, Chicago, IL, USA
Phone: 312-503-5300; Fax: 312-503-8240; E-mail: kgreen@northwestern.edu
View this article at: http://www.jci.org/articles/view/65220?key=e01448d06d00a554dcf9
ACCOMPANYING COMMENTARY
TITLE:
Desmoglein 1, Differentiation, and Disease
AUTHOR CONTACT:
John R. Stanley
Dept. Of Dermatology, Philadelphia, PA, USA
Phone: 215/898-3240; Fax: 215-573-2033; E-mail: jrstan@mail.med.upenn.edu
View this article at: http://www.jci.org/articles/view/69071?key=64cb3a0ec3a2a8bbeb4f
Researchers optimize embryonic stem cell-derived retinal progenitors for transplant
Tissues derived from embryonic stem cells (ESCs) could potentially be used to replace cells and tissues in patients with degenerative diseases, but they could also cause serious side effects - ESCs and ESC-derived progenitor cells have previously been shown to spontaneously form tumors. In this issue of the Journal of Clinical Investigation, researchers led by Ying Jin at the Institute of Health Sciences in Shanghai, identified a cellular signaling pathway that controls tumorigenicity in ESC-derived retinal progenitor cells. Retinal degeneration is a leading cause of blindness that could potentially be treated by replacement of the defective retinal cells. Jin and colleagues found that the WNT signaling cascade was a critical determinant of both the tumorigenicity and therapeutic function of ESC-derived retinal progenitors. By inhibiting WNT signaling, they could improve the function of retinal progenitors in mice while preventing tumor formation. In a companion commentary, Kang Zhang and colleagues the University of California, San Diego, discuss how these findings could broadly apply to the development of new stem cell therapies.
TITLE:
WNT signaling determines tumorigenicity and function of ESC-derived retinal progenitors
AUTHOR CONTACT:
Ying Jin
Institute of Health Sciences, CHN
Phone: 13918812150; E-mail: yjin@sibs.ac.cn
View this article at: http://www.jci.org/articles/view/65048?key=7aa034c46aa441cf9fbe
ACCOMPANYING COMMENTARY
Wnt signaling in stem cell differentiation and tumor formation
AUTHOR CONTACT:
Kang Zhang
University of California, San Diego, School of Medicine, La Jolla, CA, USA
Phone: (858) 246-0814; Fax: (858) 246-0873; E-mail: kang.zhang@gmail.com
View this article at: http://www.jci.org/articles/view/69324?key=6f41b86a23b1a3729ecd
ALSO IN THIS ISSUE
TITLE:
Coordination of hypothalamic and pituitary T3 production regulates TSH expression
AUTHOR CONTACT:
Antonio Bianco
University of Miami, Miami, FL, USA
Phone: (305)243-5631; E-mail: ABianco@med.miami.edu
View this article at: http://www.jci.org/articles/view/61231?key=75c201c58065bf3ec9d6
TITLE:
The TGR5 receptor mediates bile acid-induced itch and analgesia
AUTHOR CONTACT:
Nigel W Bunnett
Monash Institute of Pharmaceutical Sciences, Parkville, UNK, AUS
Phone: +61 3 9903 9136; E-mail: Nigel.Bunnett@Monash.edu
View this article at: http://www.jci.org/articles/view/64551?key=2ff8103182d445dd2666
TITLE:
Liver-resident NK cells confer adaptive immunity in skin-contact inflammation
AUTHOR CONTACT:
Zhigang Tian
University of Science and Technology of China, Heifei, , CHN
Phone: 86-551-360-0845; E-mail: tzg@ustc.edu.cn
View this article at: http://www.jci.org/articles/view/66381?key=8c20ed0fc0d1cca8d452
Journal
Journal of Clinical Investigation