Mesenchymal stem cells alleviate oxidative stress-induced mitochondrial dysfunction in the airways.

Oxidative stress-induced mitochondrial dysfunction can contribute to inflammation and remodeling in patients with chronic obstructive pulmonary disease (COPD). Mesenchymal stem cells protect against lung damage in animal models of COPD. It is unknown whether these effects occur through attenuating mitochondrial dysfunction in airway cells. We sought to examine the effect of induced pluripotent stem cell-derived mesenchymal stem cells (iPSC-MSCs) on oxidative stress-induce mitochondrial dysfunction in human airway smooth muscle cells (ASMCs) in vitro and in mouse lungs in vivo. ASMCs were cocultured with iPSC-MSCs in the presence of cigarette smoke medium (CSM), and mitochondrial reactive oxygen species (ROS) levels, mitochondrial membrane potential (ΔΨm), and apoptosis were measured. Conditioned medium from iPSC-MSCs and transwell cocultures were used to detect any paracrine effects. The effect of systemic injection of iPSC-MSCs on airway inflammation and hyperresponsiveness in ozone-exposed mice was also investigated. Coculture of iPSC-MSCs with ASMCs attenuated CSM-induced mitochondrial ROS, apoptosis, and ΔΨm loss in ASMCs. iPSC-MSC-conditioned medium or transwell cocultures with iPSC-MSCs reduced CSM-induced mitochondrial ROS but not ΔΨm or apoptosis in ASMCs. Mitochondrial transfer from iPSC-MSCs to ASMCs was observed after direct coculture and was enhanced by CSM. iPSC-MSCs attenuated ozone-induced mitochondrial dysfunction, airway hyperresponsiveness, and inflammation in mouse lungs. iPSC-MSCs offered protection against oxidative stress-induced mitochondrial dysfunction in human ASMCs and in mouse lungs while reducing airway inflammation and hyperresponsiveness. These effects are, at least in part, dependent on cell-cell contact, which allows for mitochondrial transfer, and paracrine regulation. Therefore iPSC-MSCs show promise as a therapy for oxidative stress-dependent lung diseases, such as COPD.

Li X ，Michaeloudes C ，Zhang Y ，Wiegman CH ，Adcock IM ，Lian Q ，Mak JCW ，Bhavsar PK ，Chung KF ... -  《-》

Oxidative stress-induced mitochondrial dysfunction drives inflammation and airway smooth muscle remodeling in patients with chronic obstructive pulmonary disease.

Inflammation and oxidative stress play critical roles in patients with chronic obstructive pulmonary disease (COPD). Mitochondrial oxidative stress might be involved in driving the oxidative stress-induced pathology. We sought to determine the effects of oxidative stress on mitochondrial function in the pathophysiology of airway inflammation in ozone-exposed mice and human airway smooth muscle (ASM) cells. Mice were exposed to ozone, and lung inflammation, airway hyperresponsiveness (AHR), and mitochondrial function were determined. Human ASM cells were isolated from bronchial biopsy specimens from healthy subjects, smokers, and patients with COPD. Inflammation and mitochondrial function in mice and human ASM cells were measured with and without the presence of the mitochondria-targeted antioxidant MitoQ. Mice exposed to ozone, a source of oxidative stress, had lung inflammation and AHR associated with mitochondrial dysfunction and reflected by decreased mitochondrial membrane potential (ΔΨm), increased mitochondrial oxidative stress, and reduced mitochondrial complex I, III, and V expression. Reversal of mitochondrial dysfunction by the mitochondria-targeted antioxidant MitoQ reduced inflammation and AHR. ASM cells from patients with COPD have reduced ΔΨm, adenosine triphosphate content, complex expression, basal and maximum respiration levels, and respiratory reserve capacity compared with those from healthy control subjects, whereas mitochondrial reactive oxygen species (ROS) levels were increased. Healthy smokers were intermediate between healthy nonsmokers and patients with COPD. Hydrogen peroxide induced mitochondrial dysfunction in ASM cells from healthy subjects. MitoQ and Tiron inhibited TGF-β-induced ASM cell proliferation and CXCL8 release. Mitochondrial dysfunction in patients with COPD is associated with excessive mitochondrial ROS levels, which contribute to enhanced inflammation and cell hyperproliferation. Targeting mitochondrial ROS represents a promising therapeutic approach in patients with COPD.

Wiegman CH ，Michaeloudes C ，Haji G ，Narang P ，Clarke CJ ，Russell KE ，Bao W ，Pavlidis S ，Barnes PJ ，Kanerva J ，Bittner A ，Rao N ，Murphy MP ，Kirkham PA ，Chung KF ，Adcock IM ，COPDMAP ... -  《-》

Study of Mesenchymal Stem Cell-Mediated Mitochondrial Transfer in In Vitro Models of Oxidant-Mediated Airway Epithelial and Smooth Muscle Cell Injury.

Michaeloudes C ，Li X ，Mak JCW ，Bhavsar PK ... -  《-》

Mitochondrial transfer of induced pluripotent stem cell-derived mesenchymal stem cells to airway epithelial cells attenuates cigarette smoke-induced damage.

Li X ，Zhang Y ，Yeung SC ，Liang Y ，Liang X ，Ding Y ，Ip MS ，Tse HF ，Mak JC ，Lian Q ... -  《-》

iPSC-derived mesenchymal stem cells exert SCF-dependent recovery of cigarette smoke-induced apoptosis/proliferation imbalance in airway cells.

Mesenchymal stem cells (MSCs) have emerged as a potential cell-based therapy for pulmonary emphysema in animal models. Our previous study demonstrated that human induced pluripotent stem cell-derived MSCs (iPSC-MSCs) were superior over bone marrow-derived MSCs (BM-MSCs) in attenuating cigarette smoke (CS)-induced airspace enlargement possibly through mitochondrial transfer. This study further investigated the effects of iPSC-MSCs on inflammation, apoptosis, and proliferation in a CS-exposed rat model and examined the effects of the secreted paracrine factor from MSCs as another possible mechanism in an in vitro model of bronchial epithelial cells. Rats were exposed to 4% CS for 1 hr daily for 56 days. At days 29 and 43, human iPSC-MSCs or BM-MSCs were administered intravenously. We observed significant attenuation of CS-induced elevation of circulating 8-isoprostane and cytokine-induced neutrophil chemoattractant-1 after iPSC-MSC treatment. In line, a superior capacity of iPSC-MSCs was also observed in ameliorating CS-induced infiltration of macrophages and neutrophils and apoptosis/proliferation imbalance in lung sections over BM-MSCs. In support, the conditioned medium (CdM) from iPSC-MSCs ameliorated CS medium-induced apoptosis/proliferation imbalance of bronchial epithelial cells in vitro. Conditioned medium from iPSC-MSCs contained higher level of stem cell factor (SCF) than that from BM-MSCs. Deprivation of SCF from iPSC-MSC-derived CdM led to a reduction in anti-apoptotic and pro-proliferative capacity. Taken together, our data suggest that iPSC-MSCs may possess anti-apoptotic/pro-proliferative capacity in the in vivo and in vitro models of CS-induced airway cell injury partly through paracrine secretion of SCF.

Li X ，Zhang Y ，Liang Y ，Cui Y ，Yeung SC ，Ip MS ，Tse HF ，Lian Q ，Mak JC ... -  《-》