Idiopathic pulmonary fibrosis is a progressive diffuse parenchymal lung disorder of unknown etiology. Mesenchymal stem cell (MSC)-based therapy is a novel approach with great therapeutic potential for the treatment of lung diseases. Despite demonstration of MSC grafting, the populations of engrafted MSCs have been shown to decrease dramatically 24 hours post-transplantation due to exposure to harsh microenvironments. Hypoxia is known to induce expression of cytoprotective genes and also secretion of anti-inflammatory, anti-apoptotic and anti-fibrotic factors. Hypoxic preconditioning is thought to enhance the therapeutic potency and duration of survival of engrafted MSCs. In this work, we aimed to prolong the duration of survival of engrafted MSCs and to enhance the effectiveness of idiopathic pulmonary fibrosis transplantation therapy by the use of hypoxia-preconditioned MSCs.
Chronic obstructive pulmonary disease (COPD) is a sustained blockage of the airways due to lung inflammation occurring with chronic bronchitis and/or emphysema. Progression of emphysema may be slowed by vascular endothelial growth factor A (VEGFA), which reduces apoptotic tissue depletion. Previously, authors of the present report demonstrated that cis-resveratrol (c-RSV)-induced heat-shock protein 70 (HSP70) promoter-regulated VEGFA expression promoted neovascularization of genetically modified mesenchymal stem cells (HSP-VEGFA-MSC) in a mouse model of ischemic disease. Here, this same stem cell line was evaluated for its protective capacity to alleviate elastase-induced pulmonary emphysema in mice. Results of this study showed that c-RSV-treatment of HSP-VEGFA-MSC exhibited synergy between HSP70 transcription activity and induced expression of anti-oxidant-related genes when challenged by cigarette smoke extracts. Eight weeks after jugular vein injection of HSP-VEGFA-MSC into mice with elastase-induced pulmonary emphysema followed by c-RSV treatment to induce transgene expression, significant improvement was observed in respiratory functions. Expression of VEGFA, endogenous nuclear factor erythroid 2-related factor (Nrf 2), and manganese superoxide dismutase (MnSOD) was significantly increased in the lung tissues of the c-RSV-treated mice. Histopathologic examination of treated mice revealed gradual but significant abatement of emphysema and restoration of airspace volume. In conclusion, the present investigation demonstrates that c-RSV-regulated VEGFA expression in HSP-VEGFA-MSC significantly improved the therapeutic effects on the treatment of COPD in the mouse, possibly avoiding side effects associated with constitutive VEGFA expression.