Navigation Links
First Potential Treatment for Dengue

Millions of people are affected by dengue globally. Dengue is a viral disease transmitted by mosquitoes of the genus Aedes. Dengue shock syndrome is a fatal shock associated// with severe blood loss, though there may or may not be any hemorrhage. The pathology of this disease is unknown thus there is no treatment or vaccine available. The only prevention is vector control.

This context brought IRD immunology and virology specialists and their research partners (1) to focus on these little-known biological mechanisms that are set into operation on infection by the virus, responsible for increasing the permeability of vascular wall endothelial cells and hence blood loss. The researchers found evidence of the role played by particular enzymes, metalloproteinases, in the occurrence of this leakage.

Low concentrations of these enzymes are present naturally in the organism, and they are involved in the reconfiguration of organ tissues during human embryonic development or tissue repair, but also in the development of certain cancers. They attack specifically the intercellular cement that binds the vascular walls. The research team demonstrated, in vitro, that Dengue-virus infection of certain targeted cells of the immune system (the dendritic cells) triggered an inflammatory reaction, stimulating these same target cells to overproduce metalloproteinases (gelatinolytic matrix metalloproteinases – MMP-9) and secrete them into the cellular supernatant (2). The quantity of enzyme produced therefore appears to be proportional to the concentration of viral particles present.

To verify that the metalloproteinases were the only agents responsible for the increased vascular permeability, the researchers performed tests on cell cultures of endothelial tissue, of the same type as that of the blood vessel walls. The supernatant of the infected cells, consequently containing the metalloproteinases, were brought into contact with this tissue. The vascular p ermeability, estimated by the quantity of supernatant passing through the endothelial tissue, appeared significantly higher. Conversely, the natural permeability of the tissue was restored when a specific inhibitor of these enzymes (SB-3CT) was added to the supernatant. Fluorescence microscope images of proteins of the intercellular cement, subjected to the action of the same supernatant, revealed that metalloproteinases act on the blood vessel walls like biological "scissors": they destroy the protein bonds which maintain cell adhesion and hence keep them together. This action was, however, neutralized by specific metalloproteinases inhibitors.

A series of in vivo experiments following the same principle confirmed these hypotheses. A mouse model with blood circulatory system colored blue was injected with supernatant containing these enzymes, on their own or in the presence of their inhibitor. This procedure not only reproduced the mechanisms of vascular rupture that originated blood leakage, but also – and more significantly – succeeded in neutralizing them.

This research sheds completely new light on Dengue's pathological strategy. The results provide a way of explaining the major role played by direct action of metalloproteinases on blood-vessel walls. The overproduction of these enzymes, linked to the viral infection and the inflammatory reaction it triggers, does not however appear to be restricted to Dengue. The mechanism described here could provide a molecular basis for a new model of the action of other known hemorrhage-inducing viruses, such as Ebola, Marburg, or Hanta. New lines of therapeutic research against these pathologies, for which no treatment yet exists, can now be envisaged. Indeed, clinical trials on Dengue are currently in preparation.

Source-Eurekalert
KM
'"/>




Related medicine news :

1. First Vaccine Designed for Africa Cleared for Testing in Humans
2. Ajanta Launches Worlds First Once-A-Day Nimesulide Oral Formulation
3. First human clone is near
4. First Artificial Heart patient has Major setback
5. First head-to-head trials of once weekly Fosamax and Actonel therapies
6. WHO Declares Vietnam First Country to Control SARS
7. Russia Reports First SARS Case
8. Hope for First New Melanoma Treatment in Decades
9. First global SARS meet opens
10. Stanford Medical Center Implements The First Virtual Cardiac Ultrasound
11. Hyderabad To Have Asia’s First Catheter Making Uni
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/5/2016)... CA (PRWEB) , ... May ... ... lectures and hands-on exercises, the Wharton Seminars for Business Journalists , ... better understanding of key business and economic issues.  This one-day program at ...
(Date:5/5/2016)... , ... May 05, 2016 , ... LELO ... self-love. Every day, LELO fans reach out via email, social media and on the ... upcoming up: “Is the way I masturbate ‘normal’ or ‘correct’?” , While some methods ...
(Date:5/5/2016)... Indianapolis, IN (PRWEB) , ... May 05, 2016 ... ... employee benefits advisory organization, announces McLaughlin & Smoak Benefits as the latest addition ... & Smoak Benefits has a dedicated team of compliance, wellness, human resources, and ...
(Date:5/5/2016)... Bremerton, WA (PRWEB) , ... May 05, 2016 , ... ... program serving the families of Bremerton, Port Orchard and communities west of Seattle. The ... Lowery, a 12 year local girl who died suddenly due to complications from the ...
(Date:5/5/2016)... ... May 05, 2016 , ... ... grants the most heartfelt wishes of these children. The wishes provide hope ... President and CEO of Make-A-Wish Mississippi, Brent Wilson said, “In 2016, the ...
Breaking Medicine News(10 mins):
(Date:5/4/2016)... Valeritas Holdings, Inc. (OTCQB: VLRX) ... offering (APO). This was accomplished via a reverse merger ... a private placement of approximately 5 million shares of ... Under the terms of the reverse merger, which ... will trade on the OTC Markets under the symbol ...
(Date:5/4/2016)... , May 4, 2016 ... of the  "Global Acute lymphocytic Leukemia Market ... to their offering.       (Logo: ... Acute Lymphocytic Leukemia Market and Competitive Landscape ... Lymphocytic Leukemia pipeline products, Acute Lymphocytic Leukemia ...
(Date:5/3/2016)... 3, 2016  As a teenager, an active and ... which damaged his heart. He continued enjoying sports and ... 2013, Shepherd,s heart was giving out and he was ... 20, 2013, the Mesa, Arizona ... Like a heart transplant, the SynCardia TAH-t is the ...
Breaking Medicine Technology: