Project description:The precise origin of newly formed alpha smooth muscle actin-positive (ACTA2+) cells appearing in non-muscularized vessels in the context of pulmonary hypertension (PH) is still debatable, although it is believed that they predominantly derive from pre-existing vascular smooth muscle cells (VSMCs). Here, Gli1Cre-ERT2; tdTomatoflox mice were used to lineage-trace GLI1+ cells in the context of PH using two independent models of vascular remodeling (VR) and reverse remodeling (RR): hypoxia and cigarette-smoke exposure (SE). Hemodynamic measurements, right ventricular hypertrophy assessment, flow cytometry, and histological analysis of thick lung sections followed by state-of-the-art 3D reconstruction and quantification using Imaris software were used to investigate the contribution of GLI1+ cells to neo-muscularization of the pulmonary vasculature. The data show that GLI1+ cells are abundant around distal, non-muscularized, vessels during steady state, and that this lineage contributes to around 50% of newly formed ACTA2+ cell around these normally non-muscularized vessels. During RR, cells derived from the GLI1+ lineage are largely cleared in parallel to the reversal of muscularization. Partial ablation of GLI1+ cells greatly prevented VR in response to hypoxia and attenuated the increase in RVSP and right heart hypertrophy. Single-cell RNA sequencing (scRNA-seq) on sorted lineage-labeled GLI1+ cells revealed an Acta2high fraction of cells with pathways in cancer and MAPK signaling as potential players in reprogramming these cells during VR. Analysis of human lung-derived material suggests that GLI1 signaling is overactivated in both Group 1 and Group 3 PH and can promote proliferation and myogenic differentiation. Our data highlight GLI1+ cells as an alternative cellular source of VSMCs in PH and suggest that these cells and the associated signaling pathways represent an important therapeutic target for further studies.
Project description:The precise origin of newly formed alpha smooth muscle actin-positive (ACTA2+) cells appearing in non-muscularized vessels in the context of pulmonary hypertension (PH) is still debatable, although it is believed that they predominantly derive from pre-existing vascular smooth muscle cells (VSMCs). Here, Gli1Cre-ERT2; tdTomatoflox mice were used to lineage-trace GLI1+ cells in the context of PH using two independent models of vascular remodeling (VR) and reverse remodeling (RR): Hypoxia and cigarette-smoke exposure (SE). Hemodynamic measurements, right ventricular hypertrophy assessment, flow cytometry, and histological analysis of thick lung sections followed by state-of-the-art 3D reconstruction and quantification using Imaris software were used to investigate the contribution of GLI1+ cells to neo-muscularization of the pulmonary vasculature. The data show that GLI1+ cells are abundant around distal, nonmuscularized vessels during steady state, and that this lineage contributes to around 50% of newly formed ACTA2+ cell around these normally non-muscularized vessels. During RR, cells derived from the GLI1+ lineage are largely cleared in parallel to the reversal of muscularization. Partial ablation of GLI1+ cells greatly prevented VR in response to hypoxia and attenuated the increase in RVSP and right heart hypertrophy. Single-cell RNA sequencing (scRNA-seq) on sorted lineage-labeled GLI1+ cells revealed an Acta2high fraction of cells with pathways in cancer and MAPK signaling as potential players in reprogramming these cells during VR. Analysis of human lungderived material suggests that GLI1 signaling is overactivated in both Group 1 and Group 3 PH and can promote proliferation and myogenic differentiation. Our data highlight GLI1+ cells as an alternative cellular source of VSMCs in PH and suggest that these cells and the associated signaling pathways represent an important therapeutic target for further studies.
Project description:NOXO1 KO mice seem to be protected from cigarette smoke-induced emphysema and pulmonary hypertension. Since the molecular mechanisms are not clear yet, this microarray experiment should help to identify the molecular differences in these KO mice compared to the wild-type (WT), figuring out how the protection occurs. Since we believe that vascular altertions could not only be responsible for vascular remodeling but also the trigger for emphysema development, we microdissected pre-capillary vessels from WT and KO mice, both controls and smoke-exposed. In addition, alveolar septa were microdissected to investigate the alveolar changes.
Project description:normal human bronchial epithelial cultures from two cultures in parallel exposed to cigarette smoke (CS) or air (mock) at timepoints 4 hours and 24 hours. Keywords = cigarette smoke Keywords = microarray Keywords = bronchial cell Keywords = tobacco Keywords: time-course
Project description:The goal of this project is to identify novel genes that contribute to inflammation in cigarette smoke induced chronic obstructive pulmonary disease (COPD). Our lab is interested in a class of RNA genes called Long noncoding RNAs (lncRNAs). There are over 16,000 lncRNAs in the human genome and less than 3% have defined functions. Here we aim to identify inflammatory specific lncRNAs that are dysregulated following cigarette smoke exposure in macrophages.
Project description:Proteasome dysfunction is emerging as a novel pathomechanism for the development of chronic obstructive pulmonary disease (COPD), a major leading cause of death in the world. Cigarette smoke is one of the main risk factors for COPD and has been shown to impair proteasome function in vitro and in vivo. Importantly, proteasome activity is inhibited in COPD lungs while expression levels of proteasome subunits are not altered. In the present study, we dissected the molecular changes induced by cigarette smoke on proteasome function in lung epithelial cells and mouse lungs. We analyzed the integrity, composition, and the interactome of isolated 26S proteasome complexes from smoke-exposed cells and mouse lungs. Moreover, we applied native MS analysis to investigate whether reactive compounds of cigarette smoke directly modify and inhibit the 20S proteasome complex. Our data reveal that the 20S proteasome is slightly destabilized in the absence of any dominant modification of proteasomal proteins. 26S pulldown and stoichiometry analysis indicated that 26S proteasome complexes become instable in response to cigarette smoke exposure. Of note, the interactome of the 26S was clearly altered in smoke-exposed mouse lungs possibly reflecting an altered cellular composition in the lungs of the smoke-exposed mice. Taken together, our results suggest that cigarette smoke induces minor but detectable changes in the stability and interactome of 20S and 26S proteasome complexes which might contribute in a chronic setting to imbalanced proteostasis as observed in chronic lung diseases associated with cigarette smoking.
Project description:Cigarette smoke is the most relevant risk factor for the development of lung cancer and chronic obstructive pulmonary disease. Many of its more than 4500 chemicals are highly reactive, thereby altering protein structure and function. Here, we used subcellular fractionation coupled to label-free quantitative MS to globally assess alterations in the proteome of different compartments of lung epithelial cells upon exposure to cigarette smoke extract. Proteomic profiling of the human alveolar derived cell line A549 revealed the most pronounced changes within the cellular secretome with preferential downregulation of proteins involved in wound healing and extracellular matrix organization. In particular, secretion of secreted protein acidic and rich in cysteine, a matricellular protein that functions in tissue response to injury, was consistently diminished by cigarette smoke extract in various pulmonary epithelial cell lines and primary cells of human and mouse origin as well as in mouse ex vivo lung tissue cultures. Our study reveals a previously unrecognized acute response of lung epithelial cells to cigarette smoke that includes altered secretion of proteins involved in extracellular matrix organization and wound healing. This may contribute to sustained alterations in tissue remodeling as observed in lung cancer and chronic obstructive pulmonary disease.
Project description:Mycbacterium tuberculosis was exposed to cigarette smoke condensate (CSC) in 7H9 dextrose culture media. The transcriptional response to cigarette smoke condensate was compared to that of exposure to the CSC diluent, DMSO..