Subepithelial fibrosis is a component of the remodeling observed in the bronchial wall of patients diagnosed with asthma. In this process, human bronchial fibroblasts (HBFs) drive the fibroblast-to-myofibroblast transition (FMT) in response to transforming growth factor-β1 (TGF-β1), which activates the canonical Smad-dependent signaling. However, the pleiotropic properties of TGF-β1 also promote the activation of non-canonical signaling pathways which can affect the FMT. In this study we investigated the effect of p38 mitogen-activated protein kinase (MAPK) inhibition by SB203580 on the FMT potential of HBFs derived from asthmatic patients using immunocytofluorescence, real-time PCR and Western blotting methods. Our results demonstrate for the first time the strong effect of p38 MAPK inhibition on the TGF-β1-induced FMT potential throughout the strong attenuation of myofibroblast-related markers: α-smooth muscle actin (α-SMA), collagen I, fibronectin and connexin 43 in HBFs. We suggest the pleiotropic mechanism of SB203580 on FMT impairment in HBF populations by the diminishing of TGF-β/Smad signaling activation and disturbances in the actin cytoskeleton architecture along with the maturation of focal adhesion sites. These observations justify future research on the role of p38 kinase in FMT efficiency and bronchial wall remodeling in asthma.

Human-induced pluripotent stem cells (hiPSCs) offer numerous possibilities in science and medicine, particularly when combined with precise genome editing methods. hiPSCs are artificially generated equivalents of human embryonic stem cells (hESCs), which possess an unlimited ability to self-renew and the potential to differentiate into any cell type of the human body. Importantly, generating patient-specific hiPSCs enables personalized drug testing or autologous cell therapy upon differentiation into a desired cell line. However, to ensure the highest standard of hiPSC-based biomedical products, their safety and reliability need to be proved. One of the key factors influencing human pluripotent stem cell (hPSC) characteristics and function is oxygen concentration in their microenvironment. In recent years, emerging data have pointed toward the beneficial effect of low oxygen pressure (hypoxia) on both hiPSCs and hESCs. In this review, we examine the state-of-the-art research on the oxygen impact on hiPSC functions and activity with an emphasis on their niche, metabolic state, reprogramming efficiency, and differentiation potential. We also discuss the similarities and differences between PSCs and cancer stem cells (CSCs) with respect to the role of oxygen in both cell types.

Precise genome editing using designer nucleases (DNs), such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) system, has become a method of choice in a variety of biological and biomedical applications in recent years. Notably, efficacy of these systems is currently under scrutiny in about 50 clinical trials. Although high DNs activity in various cell types in vitro has already been achieved, efficient in vivo genome editing remains a challenge. To solve this problem, we employed stem cells-derived extracellular vesicles (EVs) as carriers of DNs. We used umbilical cord-derived mesenchymal stem cells (UC-MSCs) and induced pluripotent stem cells (iPSCs) as EV-producer cells, since they are both applied in regenerative medicine. In our proof-of-concept studies, we achieved up to 50% of EGFP marker gene knockout in vivo using EVs carrying either ZFN, TALEN or the CRISPR/Cas9 system, particularly in the liver. Importantly, we obtained almost 50% of modified alleles in the liver of the experimental animals, when targeting the Pcsk9 gene, whose overexpression is implicated in hypercholesterolemia. Taken together, our data provide strong evidence that stem cells-derived EVs constitute a robust tool in delivering DNs in vivo, which may be harnessed to clinical practice in the future.