Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New research may boost drug efficacy in treating pulmonary arterial hypertension

08.01.2014
Intravenous/sublingual tissue-penetrating homing peptide enhances activity of other pulmonary drugs, according to new research published in the American Journal of Pathology

The development of new, more effective vasodilators to treat pulmonary arterial hypertension (PAH) has been hampered because of their systemic toxicity and adverse side effects.

An international team of investigators seeking to surmount these problems and increase drug efficacy have determined that a vascular homing peptide can selectively target hypertensive pulmonary arteries to boost the pulmonary but not systemic effects of vasodilators. Importantly for potential clinical use, this peptide retains its activity when given sublingually. The results using a rat model of PAH are published in the American Journal of Pathology.

PAH is a cardiovascular disease characterized by a resting mean pulmonary arterial pressure >25 mmHg, or >30 mmHg during exercise. Symptoms of PAH are shortness of breath, chronic fatigue, dizziness, peripheral edema, cyanosis, and chest pain. PAH results from pulmonary vasoconstriction and vascular remodelling accompanied by endothelial dysfunction, fibroblast activation, and endothelial cellular proliferation. Without treatment, heart failure and death may occur.

"Our results open the door to a new direction of PAH treatment. These findings have high clinical significance because CAR (peptide CARSKNKDC) enables the down-dosing of not only vasodilators, but any PAH drug to reduce its systemic side effects without decreasing its pulmonary efficacy," says Masahiko Oka, MD, PhD, of the Department of Pharmacology and Internal Medicine and Center for Lung Biology at the University of South Alabama.

In previous work, the investigators found that in two experimental models of PAH in rats the homing peptide CAR selectively accumulates in the walls of hypertensive pulmonary arteries. In the current study, PAH was experimentally induced in rats by subcutaneous injection of Sugen5416, followed by exposure to hypoxia for three weeks, and then returned to normal oxygen levels for two weeks. These rats manifest very high right ventricular systolic pressure (RVSP) compared to controls (102 mmHg vs.24 mmHg). Histologically, small pulmonary arteries and arterioles display severe, occlusive neointimal lesions.

Intravenous CAR was found in the pulmonary arteries of the PAH rats but not in normal pulmonary arteries. CAR was not detectable in the liver, spleen, or heart but was found in the endothelium and fibrotic tissue of severely remodeled pulmonary arterial walls. Notable levels were also found in kidney tubules but this reflects where it is excreted, say the authors.

The investigators then looked at the effects of CAR on vasodilating drugs. They found that co-administration of CAR significantly enhanced the pressure-lowering effects of the Rho kinase inhibitor fasudil on RVSP but not on systolic systemic arterial pressure. CAR also boosted the pulmonary vasodilator effects of the phosphodiesterase 5 inhibitor sildenafil and the tyrosine kinase inhibitor imatinib.

One limitation of homing peptides is finding a good route of administration. Intravenous administration is impractical on a routine basis and oral bioavailability of peptides is poor due to digestive degradation. The authors were able to show that CAR was effective when given sublingually, and this route might even be superior to administration via injection.

"Additional studies are warranted to examine if CAR works similarly in human PAH as in the rat model. However, our results open the door to a new direction of PAH treatment and warrant further investigation," says Dr. Oka.

The concepts underlying the study were first established in tumor biology with the identification of disease-specific, distinctive surface markers of tumor blood vessels that are not present in the vessels of normal tissues. Homing peptides are substances that find their way to receptors in these abnormal blood vessels, and are being developed to transport drugs selectively to tumors. These peptides can spread into tumor tissue, and can target drug delivery where it is needed. Some homing peptides chemically couple with the drug being transported, but this can weaken the drug's activity. Other homing peptides can transport a drug without chemically interacting with it, a process known as the "bystander effect"; the advantage is that the drug's activity is not compromised by its carrier.

Eileen Leahy | EurekAlert!
Further information:
http://www.elsevier.com

More articles from Health and Medicine:

nachricht Vanishing capillaries
23.03.2017 | Technische Universität München

nachricht How prenatal maternal infections may affect genetic factors in Autism spectrum disorder
22.03.2017 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>