Tag: lung fibrosis

A Novel Pathway with Potential to Slow the Progression of Pulmonary Fibrosis

Credit: Scientific Animations CC4.0

Researchers have found a potential new way to slow the progression of lung fibrosis and other fibrotic diseases by inhibiting the expression or function of Piezo2, a receptor that senses mechanical forces in tissues including stress, strain, and stiffness. The new study in The American Journal of Pathology, published by Elsevier, sheds light on the underlying mechanisms of pulmonary fibrotic diseases and identifies potential new targets and options for therapy to improve patients’ outcomes.

Pulmonary fibrotic diseases are a group of conditions that cause significant morbidity and sometimes mortality. Idiopathic pulmonary fibrosis (IPF) is a devastating progressive fibrotic lung disease with a median survival of 2.9 years from diagnosis. Lung fibrosis results in dramatic mechanical changes including increased stiffness in the tissue that cells can sense and respond to, making it difficult for the lungs to expand and contract properly during breathing.

Piezo channels are a newly discovered receptor that are sensitive to mechanical signals. Since the 2021 Nobel Prize in Medicine was awarded to Dr Ardem Patapoutian for the discovery of Piezo channels in 2010, interest has increased in their role in tissue homeostasis and disease outside of neuronal signalling, however, little has been published on their possible role in fibrotic lung diseases. A group of researchers driven to understand how mechanical forces in lung tissue contribute to and drive pulmonary fibrosis investigated the role of Piezo2 in pulmonary fibrosis using donor tissue from patients with IPF, mouse models of lung fibrosis, cell culture investigation of lung cells (fibroblasts) that create the fibrosis lesions, and by examining publicly available RNAseq datasets from other research groups.

Investigators found that:

  • Piezo2 is highly expressed in human lung tissue from patients with IPF and in multiple (different) mouse models of lung fibrosis.
  • Piezo2 is highly expressed in primary human lung fibroblasts in culture, the cells that are believed to play key roles in producing fibrosis in tissues (by proliferating and laying down matrix proteins, creating scar-like features).
  • Lung fibroblasts grown on stiffer substrates are reprogrammed to be more profibrotic, by proliferating, producing extra matrix proteins, and differentiating to scar-forming myofibroblasts.
  • Inhibition of Piezo2 with either RNA silencing or a peptide inhibitor, to prevent them from sensing the stiffness of their environment, reduces profibrotic programming.

Lead investigator Patricia J. Sime, MD, Division of Pulmonary Disease and Critical Care Medicine, Virginia Commonwealth University, says, “We are excited to report that this research that suggests inhibiting expression or function of Piezo2 could be a potential new therapeutic route to treating lung fibrosis and other fibrotic diseases. This is especially important as there is an unmet need for additional therapies for fibrotic diseases.”

Despite the introduction of nintedanib and pirfenidone for therapy of some fibrotic lung diseases, pulmonary fibrosis can remain challenging to effectively treat. This is in part because lung cells can be driven to a profibrotic phenotype by multiple pathways that reinforce each other, so that targeting one pathway alone may not be effective to slow or stop disease progression.

First author Margaret A.T. Freeberg, PhD, Division of Pulmonary Disease and Critical Care Medicine, Virginia Commonwealth University, continues, “Some types of lung fibrosis have been very difficult to treat. For example, IPF is a form of pulmonary fibrosis that often progresses. While there have been advances in therapy, the approved medications for IPF can slow, but do not always halt progression. One of the reasons that fibrosis can be difficult to effectively treat may be explained by the multiple profibrotic disease pathways that reinforce each other. Blocking Piezo2 signaling to prevent fibroblast reprogramming represents a new pathway we can target in our fight against fibrosis.”

Dr. Sime concludes, “This research identifies mechanical forces and a new specific target (Piezo2) that we can block to prevent fibrotic reprogramming of some lung cells. We believe this points to Piezo2 as an important new therapeutic target that might (by itself or in combination with other therapies) slow the progression of pulmonary fibrosis in our patients. Many new investigational drugs that target pulmonary fibrosis receive orphan drug designation from the FDA, and this may accelerate development and increase interest from pharmaceutical partners.”

Source: Elsevier

Researchers Develop Nanoparticle Therapeutic for Fibrosis

Credit: Scientific Animations CC4.0

Researchers at The University of Texas at El Paso are developing a new therapeutic approach that uses nanoparticles for the treatment of skin and lung fibrosis, conditions that can result in severe damage to the body’s tissues.

Md Nurunnabi, PhD, is an associate professor in UTEP’s School of Pharmacy and the lead researcher on two studies published this June in the Journal of Controlled Release; one study focuses on skin fibrosis and the other on lung fibrosis.

“We are closer than ever to developing a safe, effective and reliable approach to treating fibrosis,” Nurunnabi said.

Fibrosis is a condition in which the tissues in an organ become thicker and stiffer, Nurunnabi says. This can have multiple damaging effects, such as the lungs not being able to hold enough oxygen or blood vessels becoming narrower, leading to high blood pressure.

“I studied fibrosis during my postdoctoral training but became interested in focusing on it in my lab during the COVID-19 pandemic,” Nurunnabi said. “I observed that many people were passing away not because of COVID itself, but because of the inflammation and fibrosis caused by the viral infection in the lungs. Our lab focuses on developing nanotechnology that can target specific cells.”

Fibrosis can occur as a side effect of chemotherapy or the result of a viral infection or autoimmune disease, a condition in which the body’s immune system attacks its own cells. For example, with an autoimmune condition, the body kills fibroblasts, the cells that help form connective tissue. The body then produces more collagen than it needs, which leads to fibrosis.

Nurunnabi’s team focused on designing a nanoparticle that could target the cells that are responsible for fibrosis development and progression without disturbing the “good” cells necessary for the body’s healthy functioning. Rather than killing the ”bad” cells, the team was successful in modifying them so that they no longer produced excess collagen, in effect rehabilitating the cells. The studies were conducted in the test tube and in mice.  

“Dr Nurunnabi’s research into skin and lung fibrosis sheds light on the devastating impact of these conditions, whether acute or chronic,” said José Rivera, PharmD, founding dean of the School of Pharmacy. “His findings offer hope for improved treatments that could significantly increase life expectancy and enhance the quality of life for affected individuals.” 

Source: University of Texas at El Paso

To Beat Lung Fibrosis, Researchers Turn to Body’s own Healing Powers

Photo by Robina Weermeijer on Unsplash

The most common type of lung fibrosis is idiopathic – of unknown cause. Researchers are urgently trying to find ways to prevent or slow idiopathic pulmonary fibrosis (IPF) and related lung conditions, which can cause worsening shortness of breath, dry cough, and extreme fatigue. Average survival following diagnosis of IPF is just three to five years, and the disease has no cure.

A recent U-M study from a team led by Sean Fortier, MD and Marc Peters-Golden, MD at University of Michigan Medical School uncovers a pathway used during normal wound healing that has the potential to reverse IPF. They published their research in the Journal of Clinical Investigation.

Using a mouse model, they simulated IPF by administering bleomycin, a chemotherapy agent that causes cell injury and confirmed that the resulting lung scarring resolved itself over the span of about six weeks.

Because of this, “studying fibrosis is kind of tough,” said Fortier. “If we’re going to give experimental drugs to try and resolve fibrosis, we have to do it before it resolves on its own.

Otherwise, we will not be able to tell if the resolution was the action of the drug or natural repair mechanisms of the body.”

However, he said, “there’s actually a lot to learn about how the mouse gets better on its own. If we can learn the molecular mechanisms by which this occurs, we may uncover new targets for IPF.”

The process by which lung injury either leads to healing or fibrosis relies in part on what happens to fibroblasts – cells which forms connective tissue.

During injury or illness, fibroblasts are activated, becoming myofibroblasts that form scar tissue by secreting collagen. When the job is done, these fibroblasts must be deactivated, or de-differentiated, to go back to their quiet state or undergo programmed cell death and be cleared.

“This is the major distinction between normal wound healing and fibrosis – the persistence of activated myofibroblasts,” explained Fortier. That deactivation is controlled by molecular brakes. The study examined one of these brakes, called MKP1 – which the team found was expressed at lower levels in fibroblasts from patients with IPF.

By genetically eliminating MKP1 in fibroblasts of mice after establishing lung injury, the team saw that fibrosis continued uncontrolled.

“Instead of at day 63, seeing that nice resolution, you still see fibrosis,” said Fortier.

“We argued by contradiction: when you knock out this brake, fibrosis that would otherwise naturally disappear, persists and therefore MKP1 is necessary for spontaneous resolution of fibrosis.”

They performed several additional studies using CRISPR techniques to demonstrate how MKP1 applies the brakes, mainly by deactivating the enzyme p38α, which is implicated in a cell’s reaction to stress.

Furthermore, they demonstrated that neither of the two current FDA approved drugs for lung fibrosis, pirfenidone and nintedanib, are able to turn off myofibroblasts.

“That’s totally in keeping with the fact that they do slow the progression, but they don’t halt or reverse disease,” said Fortier.

Fortier hopes the discovery that this pathway reverses fibrosis leads to exploration of additional brakes on fibrosis.

“So much work on fibrosis has focused on how we can prevent it, but when a patient presents to my clinic with a dry cough, shortness of breath, and low oxygen as a result of underlying IPF, the scarring is already present. Of course, we’d love a way to prevent the scarring from getting worse, but the Holy Grail is to reverse it.”

Source: Michigan Medicine – University of Michigan