Possible Therapeutic Target Found for Idiopathic Pulmonary Fibrosis
Idiopathic pulmonary fibrosis is a chronic disease. The clinical management and treatment of this fatal disease are challenging for various reasons. And although antifibrotic therapies exist, doctors are still unable to tell which patient will benefit from individual treatments.
The family of interstitial lung diseases is characterized by cellular proliferation, interstitial inflammation, fibrosis or a combination of such findings within the alveolar wall that is not due to infection or cancer. The most common chronic condition is idiopathic pulmonary fibrosis a chronic progressive, fibrotic interstitial lung disease. It is often misdiagnosed, managed inappropriately, and associated with high mortality rate. This disease presents with chronic exertion difficulty breathing, dry chronic cough, bilateral Velcro-like crackles, resting low oxygen levels or dramatic decrease in oxygen with exertion. Interstitial pulmonary fibrosis carries a poor prognosis with the median age of 3.8 years among adults 60 years or more in the US. Most patients succumb to acute respiratory failure (Lederer & Martinez, 2018).
In an article published online researchers at Medical University of South Carolina report that they have identified a potential therapeutic target for lung fibrosis or scarring. They showed that the protein-promotes fibrosis by turning on profibrotic genes and increase levels of profibrotic factors. The lung fibrosis, lung tissue thickens, stiffens and scars. It can’t function normally and that leads to patients having breathing difficulty. The only real treatment is a lung transplant but few patients are eligible. That is why researchers need to find new effective treatments for idiopathic pulmonary fibrosis (Nguyen et al, 2018).
What exactly is IPF?
Despite the best medical management, idiopathic pulmonary fibrosis remains a progressive disease. Even with the different causative things the actual underlying pathological mechanism remains poorly characterized. Anti-inflammatory medications do not improve the clinical outcomes. Even though the FDA has approved two anti-fibrotic medications for treatment of IPF, many patients are not able to tolerate the toxicities and the fact it still remains a fatal disease makes it hard to treat. Some of the toxicities include diarrhea, photosensitivity, and liver dysfunction. This study has found IL-11 is a novel target for future studies for treatment of IPF with less drastic side effects. IL-11 neutralization shows improvement in overall progression of IPF while not stopping it entirely; it is being seen as a good place to start further research (Ng et al, 2018).
IPF is a chronic and progressive fibrotic lung disease with a short median survival rate of three to five years. It has excessive collagen deposits eventually leading to respiratory failure. This disease has also been found to create an increase in lung cancer. IPF lung cancer is challenging to treat even in the early stages because of the risk of increased chance of exacerbation of respiratory impairment after surgery. This study found that these growths tended to appear where IPF affected lung tissue met the ‘normal’ or unaffected tissue. These tumors appear to be related to long term smoking and environmental exposure to carcinogens (Hwang et al, 2018).
What is next?
Idiopathic pulmonary fibrosis is a progressive disease with limited therapeutic options. And while there are presently two approved drugs for treatment, neither are tolerated well leaving IPF patients in need of more effective treatments. The disease is thought to arise after damage to the air sacs occurs from smoking or other environmental exposure. This study found TGFβ-1 was a pro-fibrotic maker in human lungs. And it is a key growth factor driving the fibrosis of IPF. This model the researchers used may represent an invaluable new tool to facilitate the analysis of causative factors. And the Kca 3.1 ion channel promotes TGFβ-1 dependent activation may be a potential area for further research (Roach et al, 2018).
In this study the researchers explored the potential role Homer-1 in IPF cells obtained from human lungs with IPF were treated with TGFβ-1 and it was noted to have an expression of Homer-1. The results were that IPF fibroblasts treated with TGFβ-1 showed more changes than in normal cells. Thus the researchers of this study feel TGFβ-1 long treatment modifies methylation patterns in IPF. In addition Homer-1 showed a hyper-mentholated unregulated localized in fibroblastic foci in IPF may play a role in increasing resistance to apoptosis in the diseased lungs (Negreros et al, 2018).
At present the etiology of idiopathic pulmonary fibrosis remains elusive. Over the past two decades researchers have identified and described the underlying processes that result in metabolic dysregulation, metabolic reprogramming and mitochondrial dysfunction observed in the cells of IPF lungs. Metabolic changes in IPF include decreased efficiency of electron transport chain function. These changes also have potential impact on lung cell function, differentiation and activation of fibrotic responses. These alterations result in activation of TGFβ-1and predispose to development of pulmonary fibrosis. (Zank et al, 2018).
This disease has high mortality and morbidity. The hallmark of the disease is impaired healing after alveolar injury. Development of the two present drugs has changed the landscape of treatment but more work needs to be done. IPF is a complex disease involving several different pathways ending up with fibrosis. Better end points will need to include use of multidrug treatments and individually personalized genotyping as well (Aryal & Nathan, 2018).
Aryal, S. & Nathan, S. D. (2018). An update on emerging drugs for the treatment of idiopathic pulmonary fibrosis. Expert Opinion on Emerging Drugs, 23(2).
Hwang, J.A. et al. (2018). Genomic profiles of lung cancer associated with idiopathic pulmonary fibrosis. Journal of Pathology, 244(1).
Kreuter, M. & Maher, T. (2018), Gazing into the crystal ball: Can treatment response be predicted in IPF? The Lancet-Respiratory Medicine.
Lederer, D.J. & Martinez,F.J. (2018). Idiopathic Pulmonary Fibrosis. The New England Journal of Medicine, 378(19).
Negreros, N. et al. (2018). Transforming growth factor beta 1 induced profound methylation changes in fibroblasts, and revealed an unexpected role of Homer1 in Idiopathic pulmonary fibrosis. American Thoracic Society 2018 International Conference.
Ng, B. et al. (2018). IL-11 is a therapeutic target in idiopathic pulmonary fibrosis. bioRxiv.
Nguyen, X.X. et al. (2018). Potential therapeutic target for lung fibrosis identified. The Medical University of South Carolina.
Roach, K.M. et al. (2018). A model of human lung fibrogenesis for assessment of anti-fibrotic strategies in idiopathic pulmonary fibrosis. Scientific Reports,8(342).
Zank, D.C. et al. (2018). Idiopathic pulmonary fibrosis: Aging, mitochondrial dysfunction, and cellular bioenergetics. Frontiers in Medicine-Pulmonary Medicine.