Tag: lung disease

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Researchers Breathe New Life into Lung Repair

by Nathi Magubane

Image: iStock/Mohammed Haneefa Nizamudeen

In the human body, the lungs and their vasculature can be likened to a building with an intricate plumbing system. The lungs’ blood vessels are the pipes essential for transporting blood and nutrients for oxygen delivery and carbon dioxide removal. Much like how pipes can get rusty or clogged, disrupting normal water flow, damage from respiratory viruses, like SARS-CoV-2 or influenza, can interfere with this “plumbing system.”

In a recent study, researchers looked at the critical role of vascular endothelial cells in lung repair. Their work, published in Science Translational Medicine, was led by Andrew Vaughan of the University of Pennsylvania’s School of Veterinary Medicine and shows that, by using techniques that deliver vascular endothelial growth factor alpha (VEGFA) via lipid nanoparticles (LNPs), that they were able to greatly enhance modes of repair for these damaged blood vessels, much like how plumbers patch sections of broken pipes and add new ones.

“While our lab and others have previously shown that endothelial cells are among the unsung heroes in repairing the lungs after viral infections like the flu, this tells us more about the story and sheds light on the molecular mechanisms at play,” says Vaughan, assistant professor of biomedical sciences at Penn Vet. “Here we’ve identified and isolated pathways involved in repairing this tissue, delivered mRNA to endothelial cells, and consequently observed enhanced recovery of the damaged tissue. These findings hint at a more efficient way to promote lung recovery after diseases like COVID-19.”

They found VEGFA’s involvement in this recovery, while building on work in which they used single cell RNA sequencing to identify transforming growth factor beta receptor 2 (TGFBR2) as a major signaling pathway. The researchers saw that when TGFBR2 was missing it stopped the activation of VEGFA. This lack of signal made the blood vessel cells less able to multiply and renew themselves, which is vital for the exchange of oxygen and carbon dioxide in the tiny air sacs of the lungs.

“We’d known there was a link between these two pathways, but this motivated us to see if delivering VEGFA mRNA into endothelial cells could improve lung recovery after disease-related injury,” says first author Gan Zhao, a postdoctoral researcher in the Vaughan Lab.

The Vaughan Lab then reached out to Michael Mitchell of the School of Engineering and Applied Science, whose lab specializes in LNPs, to see if delivery of this mRNA cargo would be feasible.

“LNPs have been great for vaccine delivery and have proven incredibly effective delivery vehicles for genetic information. But the challenge here was to get the LNPs into the bloodstream without them heading to the liver, which is where they tend to congregate as its porous structure lends favor to substances passing from the blood into hepatic cells for filtration,” says Mitchell, an associate professor of bioengineering at Penn Engineering and a coauthor of the paper. “So, we had to devise a way to specifically target the endothelial cells in the lungs.”

Lulu Xue, a postdoctoral researcher in the Mitchell Lab and a co-first author of the paper, explains that they engineered the LNP to have an affinity for lung endothelial cells, this is known as extra hepatic delivery, going beyond the liver.

Read the full story in Penn Today.

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Week in BioE (September 8, 2017)

A Breath of Fresh Air

lung grafts
A macrophage in the alveolus of a lung.

At Columbia, a new way of treating lung disease is under development. As reported recently in Science Advances, a Columbia research group, headed by Gordana Vunjak-Novakovic, Ph.D., from the Department of Biomedical Engineering, developed a way to prepare grafted lung tissue for transplantation that could make the process easier. The challenge has been removing the epithelial cells, which ultimately make up the surface of the organ, from potential grafts without damaging the blood vessels. Applying a detergent solution to lung tissue from rats, Dr. Vunjak-Novakovic’s team was able to obtain grafts that could subsequently be used as scaffolds for human pulmonary cells and stem cell-derived lung epithelial cells.  Although this approach remains in a very early state, the results here indicate promise for this technology for end-stage lung diseases such as emphysema.

Eliminating Obesity and Diabetes With Injections

You’ve probably heard that there’s an epidemic of obesity in the United States. Obesity carries an enormous health cost because it is linked to a variety of major health complications, including diabetes and heart disease. At a cell level, white fat cells require more energy to work off than brown fat cells. Approaches to fight obesity now include efforts to increase the number of brown fat cells. Scientists at Purdue University might have found a significant shortcut to creating more brown fat cells. By inhibiting the Notch signaling pathway, Meng Deng, Ph.D., of the Weldon School of Biomedical Engineering and his colleagues were able to cause white fat cells to convert into brown cells. Reporting their results in Molecular Therapy, the team used nanoparticles loaded with dibenazapine, a chemical used widely in pharmacology, to treat obese mice with targeted injections of the drug-laden nanoparticles. Results showed that the reduction of white fat in the mice was correlated with improved glucose metabolism and reduced body weight. While it’s not yet time to cancel the gym membership, an easier way to combat obesity could be on the horizon.

Diabetes is a chronic health condition with treatments that include diet management and/or insulin injections. In a new twist on diabetes treatments, scientists at the University of Toronto have shown, in a recent PNAS study, that pancreatic islets cells, which produce insulin, could be injected subcutaneously to reverse diabetes in mice. While the idea of transplanting islets into the pancreas has been investigated for some time, this is the first time that transplants were placed under the skin, far away from the pancreas. Impressively, the modules could be retrieved and reused. If future investigations are successful, these modules could form the basis of a treatment for type 1 (so-called juvenile) diabetes, which is caused by autoimmune destruction of the pancreatic islets.

News from New England

Feng Zhang, Ph.D., associate professor in the Departments of Brain and Cognitive Sciences and of Biological Engineering at MIT, is one of five scientists to receive the Albany Medical Prize in Medicine and Biomedical Research for his work on CRISPR-Cas9 gene editing technology. We offer Dr. Zhang our heartfelt congratulations.

Across the river from Cambridge in Medford, Tufts University has announced that its newly completed Science and Engineering Complex (SEC) will open this semester and will combine classrooms and laboratories — specifically what the developers are calling “lab neighborhoods,” or spaces for collaboration among laboratories working on related research questions. Bruce Panilaitis, Ph.D., a research assistant professor in the Department of Biomedical Engineering, is the director of the SEC, and his department will also have offices there.