RationaleSevere asthma and chronic obstructive pulmonary disease (COPD) share common pathophysiological traits such as relative corticosteroid insensitivity. We recently published three... Show moreRationaleSevere asthma and chronic obstructive pulmonary disease (COPD) share common pathophysiological traits such as relative corticosteroid insensitivity. We recently published three transcriptome-associated clusters (TACs) using hierarchical analysis of the sputum transcriptome in asthmatics from the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) cohort comprising one Th2-high inflammatory signature (TAC1) and two Th2-low signatures (TAC2 and TAC3). ObjectiveWe examined whether gene expression signatures obtained in asthma can be used to identify the subgroup of patients with COPD with steroid sensitivity. MethodsUsing gene set variation analysis, we examined the distribution and enrichment scores (ES) of the 3 TACs in the transcriptome of bronchial biopsies from 46 patients who participated in the Groningen Leiden Universities Corticosteroids in Obstructive Lung Disease COPD study that received 30 months of treatment with inhaled corticosteroids (ICS) with and without an added long-acting beta-agonist (LABA). The identified signatures were then associated with longitudinal clinical variables after treatment. Differential gene expression and cellular convolution were used to define key regulated genes and cell types. Measurements and main resultsBronchial biopsies in patients with COPD at baseline showed a wide range of expression of the 3 TAC signatures. After ICS +/- LABA treatment, the ES of TAC1 was significantly reduced at 30 months, but those of TAC2 and TAC3 were unaffected. A corticosteroid-sensitive TAC1 signature was developed from the TAC1 ICS-responsive genes. This signature consisted of mast cell-specific genes identified by single-cell RNA-sequencing and positively correlated with bronchial biopsy mast cell numbers following ICS +/- LABA. Baseline levels of gene transcription correlated with the change in RV/TLC %predicted following 30-month ICS +/- LABA. ConclusionSputum-derived transcriptomic signatures from an asthma cohort can be recapitulated in bronchial biopsies of patients with COPD and identified a signature of airway mast cells as a predictor of corticosteroid responsiveness. Show less
Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) specific CD4(+ )and CD8(+) T cells in SARS- CoV- 2-unexposed donors has been explained by the presence of T cells primed... Show moreDetection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) specific CD4(+ )and CD8(+) T cells in SARS- CoV- 2-unexposed donors has been explained by the presence of T cells primed by other coronaviruses. However, based on the relatively high frequency and prevalence of cross-reactive T cells, we hypothesized cytomegalovirus (CMV) may induce these cross-reactive T cells. Stimulation of pre-pandemic cryo-preserved peripheral blood mononuclear cells (PBMCs) with SARS- CoV- 2 peptides revealed that frequencies of SARS- CoV- 2-specific T cells were higher in CMVseropositive donors. Characterization of these T cells demonstrated that membrane-specific CD4(+ )and spike-specific CD8(+) T cells originate from cross-reactive CMVspecific T cells. Spike-specific CD8(+ )T cells recognize SARS- CoV- 2 spike peptide FVSNGTHWF (FVS) and dissimilar CMV pp65 peptide IPSINVHHY (IPS) presented by HLA- B*35:01. These dual IPS/FVS-reactive CD8(+) T cells were found in multiple donors as well as severe COVID- 19 patients and shared a common T cell receptor (TCR), illustrating that IPS/FVS- cross-reactivity is caused by a public TCR. In conclusion, CMVspecific T cells cross react with SARS-CoV- 2, despite low sequence homology between the two viruses, and may contribute to the pre-existing immunity against SARS-CoV- 2. Show less
Background: The role of the pulmonary microbiome in sarcoidosis is unknown. The objectives of this study were the following: (1) examine whether the pulmonary fungal and bacterial microbiota... Show moreBackground: The role of the pulmonary microbiome in sarcoidosis is unknown. The objectives of this study were the following: (1) examine whether the pulmonary fungal and bacterial microbiota differed in patients with sarcoidosis compared with controls; (2) examine whether there was an association between the microbiota and levels of the antimicrobial peptides (AMPs) in protected bronchoalveolar lavage (PBAL).Methods: Thirty-five sarcoidosis patients and 35 healthy controls underwent bronchoscopy and were sampled with oral wash (OW), protected BAL (PBAL), and left protected sterile brushes (LPSB). The fungal ITS1 region and the V3V4 region of the bacterial 16S rRNA gene were sequenced. Bioinformatic analyses were performed with QIIME 2. The AMPs secretory leucocyte protease inhibitor (SLPI) and human beta defensins 1 and 2 (hBD-1 and hBD-2), were measured in PBAL by enzyme-linked immunosorbent assay (ELISA).Results: Aspergillus dominated the PBAL samples in sarcoidosis. Differences in bacterial taxonomy were minor. There was no significant difference in fungal alpha diversity between sarcoidosis and controls, but the bacterial alpha diversity in sarcoidosis was significantly lower in OW (p = 0.047) and PBAL (p = 0.03) compared with controls. The beta diversity for sarcoidosis compared with controls differed for both fungi and bacteria. AMP levels were significantly lower in sarcoidosis compared to controls (SLPI and hBD-1:p < 0.01). No significant correlations were found between alpha diversity and AMPs.Conclusions: The pulmonary fungal and bacterial microbiota in sarcoidosis differed from in controls. Lower antimicrobial peptides levels were seen in sarcoidosis, indicating an interaction between the microbiota and the innate immune system. Whether this dysbiosis represents a pathogenic mechanism in sarcoidosis needs to be confirmed in experimental studies. Show less
Slob, E.M.A.; Faiz, A.; Nijnatten, J. van; Vijverberg, S.J.H.; Longo, C.; Kutlu, M.; ... ; Koppelman, G.H. 2022
Background Vitamin D deficiency is frequently found in patients with chronic obstructive pulmonary disease (COPD). Vitamin D has antimicrobial, anti-inflammatory, and immunomodulatory effects.... Show moreBackground Vitamin D deficiency is frequently found in patients with chronic obstructive pulmonary disease (COPD). Vitamin D has antimicrobial, anti-inflammatory, and immunomodulatory effects. Therefore, supplementation may prevent COPD exacerbations, particularly in deficient patients. Objectives We aimed to assess the effect of vitamin D supplementation on exacerbation rate in vitamin D-deficient patients with COPD. Methods We performed a multicenter, double-blind, randomized controlled trial. COPD patients with >= 1 exacerbations in the preceding year and a vitamin D deficiency (15-50 nmol/L) were randomly allocated in a 1:1 ratio to receive either 16,800 International Units (IU) vitamin D-3 or placebo once a week during 1 y. Primary outcome of the study was exacerbation rate. Secondary outcomes included time to first and second exacerbations, time to first and second hospitalizations, use of antibiotics and corticosteroids, pulmonary function, maximal respiratory mouth pressure, physical performance, skeletal muscle strength, systemic inflammatory markers, nasal microbiota composition, and quality of life. Results The intention-to-treat population consisted of 155 participants. Mean +/- SD serum 25-hydroxyvitamin D [25(OH)D] concentration after 1 y was 112 +/- 34 nmol/L in the vitamin D group, compared with 42 +/- 17 nmol/L in the placebo group. Vitamin D supplementation did not affect exacerbation rate [incidence rate ratio (IRR): 0.90; 95% CI: 0.67, 1.21]. In a prespecified subgroup analysis in participants with 25(OH)D concentrations of 15-25 nmol/L (n = 31), no effect of vitamin D supplementation was found (IRR: 0.91; 95% CI: 0.43, 1.93). No relevant differences were found between the intervention and placebo groups in terms of secondary outcomes. Conclusions Vitamin D supplementation did not reduce exacerbation rate in COPD patients with a vitamin D deficiency. This trial was registered at clinicaltrials.gov as NCT02122627. Show less
Chronic exposure to environmental pollutants is a major contributor to the development and progression of obstructive airway diseases, including asthma and COPD. Understanding the mechanisms... Show moreChronic exposure to environmental pollutants is a major contributor to the development and progression of obstructive airway diseases, including asthma and COPD. Understanding the mechanisms underlying the development of obstructive lung diseases upon exposure to inhaled pollutants will lead to novel insights into the pathogenesis, prevention and treatment of these diseases. The respiratory epithelial lining forms a robust physicochemical barrier protecting the body from inhaled toxic particles and pathogens. Inhalation of airborne particles and gases may impair airway epithelial barrier function and subsequently lead to exaggerated inflammatory responses and airway remodelling, which are key features of asthma and COPD. In addition, air pollutant-induced airway epithelial barrier dysfunction may increase susceptibility to respiratory infections, thereby increasing the risk of exacerbations and thus triggering further inflammation. In this review, we discuss the molecular and immunological mechanisms involved in physical barrier disruption induced by major airborne pollutants and outline their implications in the pathogenesis of asthma and COPD. We further discuss the link between these pollutants and changes in the lung micmbiome as a potential factor for aggravating airway diseases. Understanding these mechanisms may lead to identification of novel targets for therapeutic intervention to restore airway epithelial integrity in asthma and COPD. Show less
Current knowledge about the respiratory microbiome is mainly based on 16S ribosomal RNA gene sequencing. Newer sequencing approaches, such as metatranscriptomics, offer the technical ability to... Show moreCurrent knowledge about the respiratory microbiome is mainly based on 16S ribosomal RNA gene sequencing. Newer sequencing approaches, such as metatranscriptomics, offer the technical ability to measure the viable microbiome response to environmental conditions such as smoking as well as to explore its functional role by investigating host-microbiome interactions. However, knowledge about its feasibility in respiratory microbiome research, especially in lung biopsies, is still very limited. RNA sequencing was performed in bronchial biopsies from clinically stable smokers (n=5) and ex-smokers (n=6) with COPD not using (inhaled) steroids. The Trinity assembler was used to assemble non-human reads in order to allow unbiased taxonomical and microbial transcriptional analyses. Subsequently, host-microbiome interactions were analyzed based on associations with host transcriptomic data. Ultra-low levels of microbial mass (0.009%) were identified in the RNA-seq data. Overall, no differences were identified in microbiome diversity or transcriptional profiles of microbial communities or individual microbes between COPD smokers and ex-smokers in the initial test dataset as well as a larger replication dataset. We identified an upregulated host gene set, related to the simultaneous presence of Bradyrhizobium, Roseomonas, Brevibacterium.spp., which were related to PERK-mediated unfolded protein response (UPR) and expression of the microRNA-155-5p. Our results show that metatranscriptomic profiling in bronchial biopsy samples from stable COPD patients yields ultra-low levels of microbial mass. Further, this study illustrates the potential of using transcriptional profiling of the host and microbiome to gain more insight into their interaction in the airways. Show less
BackgroundThe lower airways microbiome and host immune response in chronic pulmonary diseases are incompletely understood. We aimed to investigate possible microbiome characteristics and key... Show moreBackgroundThe lower airways microbiome and host immune response in chronic pulmonary diseases are incompletely understood. We aimed to investigate possible microbiome characteristics and key antimicrobial peptides and proteins in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD).Methods12 IPF patients, 12 COPD patients and 12 healthy controls were sampled with oral wash (OW), protected bronchoalveolar lavage (PBAL) and right lung protected sterile brushings (rPSB). The antimicrobial peptides and proteins (AMPs), secretory leucocyte protease inhibitor (SLPI) and human beta defensins 1 and 2 (hBD-1 & hBD-2), were measured in PBAL by enzyme linked immunosorbent assay (ELISA).The V3V4 region of the bacterial 16S rDNA gene was sequenced. Bioinformatic analyses were performed with QIIME 2.ResultshBD-1 levels in PBAL for IPF were lower compared with COPD. The predominant phyla in IPF were Firmicutes, Bacteroides and Actinobacteria; Proteobacteria were among top three in COPD. Differential abundance analysis at genus level showed significant differences between study groups for less abundant, mostly oropharyngeal, microbes. Alpha diversity was lower in IPF in PBAL compared to COPD (p = 0.03) and controls (p = 0.01), as well as in rPSB compared to COPD (p = 0.02) and controls (p = 0.04). Phylogenetic beta diversity showed significantly more similarity for IPF compared with COPD and controls. There were no significant correlations between alpha diversity and AMPs.ConclusionsIPF differed in microbial diversity from COPD and controls, accompanied by differences in antimicrobial peptides. Beta diversity similarity between OW and PBAL in IPF may indicate that microaspiration contributes to changes in its microbiome. Show less
Aliee, H.; Massip, F.; Qi, C.C.; Biase, M.S. de; Nijnatten, J. van; Kersten, E.T.G.; ... ; INER-Ciencias Mexican Lung Program 2021
Air-liquid interface (ALI) cultures are frequently used in lung research but require substantial cell numbers that cannot readily be obtained from patients. We explored whether organoid expansion ... Show moreAir-liquid interface (ALI) cultures are frequently used in lung research but require substantial cell numbers that cannot readily be obtained from patients. We explored whether organoid expansion [three-dimensional (3D)] can be used to establish ALI cultures from clinical samples with low epithelial cell numbers. Airway epithelial cells were obtained from tracheal aspirates (TA) from pre-term newborns and from bronchoalveolar lavage (BAL) or bronchial tissue (BT) from adults. TA and BAL cells were 3D-expanded, whereas cells from BT were expanded in 3D and 2D. Following expansion, cells were cultured at ALI to induce differentiation. The impact of cell origin and 2D or 3D expansion was assessed with respect to 1) cellular composition, 2) response to cigarette smoke exposure, and 3) effect of Notch inhibition or IL-13 stimulation on cellular differentiation. We established well-differentiated ALI cultures from all samples. Cellular compositions (basal, ciliated, and goblet cells) were comparable. All 3D-expanded cultures showed a similar stress response following cigarette smoke exposure but differed from the 2D-expanded cultures. Higher peak levels of antioxidant genes HMOX1 and NQO1 and a more rapid return to baseline, and a lower unfolded protein response was observed after cigarette smoke exposure in 3D-derived cultures compared to 2D-derived cultures. In addition, TA- and BAL-derived cultures were less sensitive to modulation by DAPT or IL-13 than BT-derived cultures. Organoid-based expansion of clinical samples with low cell numbers, such as TA from preterm newborns is a valid method and tool to establish ALI cultures. Show less
Bonda, W.L.M.; Lavergne, M.; Vasseur, V.; Brisson, L.; Roger, S.; Legras, A.; ... ; Reverdiau, P. 2021
Inflammation, oxidative stress, and protease/protease inhibitor imbalance with excessive production of proteases are factors associated with pathogenesis of the chronic obstructive pulmonary... Show moreInflammation, oxidative stress, and protease/protease inhibitor imbalance with excessive production of proteases are factors associated with pathogenesis of the chronic obstructive pulmonary disease (COPD). In this study, we report that kallikrein-related peptidase 5 (KLK5) is a crucial protease involved in extracellular matrix (ECM) remodeling and bronchial epithelial repair after injury. First, we showed that KLK5 degrades the basal layer formed by culture of primary bronchial epithelial cells from COPD or non-COPD patients. Also, exogenous KLK5 acted differently on BEAS-2B cells already engaged in epithelial-to-mesenchymal transition (EMT) or on 16HBE 14o- cells harboring epithelial characteristics. Indeed, by inducing EMT, KLK5 reduced BEAS-2B cell adherence to the ECM. This effect, neutralized by tissue factor pathway inhibitor 2, a kunitz-type serine protease inhibitor, was due to a direct proteolytic activity of KLK5 on E-cadherin, beta-catenin, fibronectin, and alpha 5 beta 1 integrin. Thus, KLK5 may strengthen EMT mechanisms and promote the migration of cells by activating the mitogen-activated protein kinase signaling pathway required for this function. In contrast, knockdown of endogenous KLK5 in 16HBE14o- cells, accelerated wound healing repair after injury, and exogenous KLK5 addition delayed the closure repair. These data suggest that among proteases, KLK5 could play a critical role in airway remodeling events associated with COPD during exposure of the pulmonary epithelium to inhaled irritants or smoking and the inflammation process. Show less
Rafiq, R.; Haddaoui, H. el; Mutsert, R. de; Rosendaal, F.R.; Hiemstra, P.S.; Cobbaert, C.M.; ... ; Jongh, R.T. de 2020
Objective: The role of adiposity in the relationship between vitamin D and inflammation is unknown. Our aim was therefore to assess the association of serum 25-hydroxyvitamin D (25(OH)D) with C... Show moreObjective: The role of adiposity in the relationship between vitamin D and inflammation is unknown. Our aim was therefore to assess the association of serum 25-hydroxyvitamin D (25(OH)D) with C-reactive protein (CRP), leptin and adiponectin and the role of adiposity in this relationship.Methods: This is a cross-sectional analysis of The Netherlands Epidemiology of Obesity Study (NEO), a population-based cohort study in men and women aged 45 to 65 years. Main outcome measures were CRP, leptin and adiponectin. In the linear regression analyses we adjusted for age, sex, ethnicity, creatinine, education, alcohol use, smoking status, physical activity, number of chronic diseases, season, total body fat and waist circumference.Results: Of the 6287 participants, 21% were vitamin D deficient (serum 25(OH)D < 50 nmol/L). Mean (SD) age and BMI were 56 (6) years and 26.3 (4.4) kg/m(2), respectively. Although after adjustment for most examined potential confounders, each 10 nmol/L increase in serum 25(OH)D was associated with 2.3% (95%CI: -4.0 to -0.5) lower CRP, 3.5% (-4.7 to -2.2) lower leptin, and 0.13 ng/mL (0.04-0.21) higher adiponectin, most of these associations seemed to largely stem from an additional potential confounder - adiposity - as they either disappeared (leptin and CRP) or were largely diminished (adiponectin) upon further adjustment for adiposity indices (total body fat and waist circumference).Conclusion: We found that measures of adiposity largely explained the negative association of serum 25(OH)D with the pro-inflammatory CRP and leptin, and the positive association with the anti-inflammatory adiponectin. These results suggest that future studies should take the effect of adiposity into account. Show less
Osteopontin (OPN) plays a role in inflammation via recruitment of neutrophils and tissue remodeling. In this study, we investigated the distribution of OPN-expressing cells in the airway epithelium... Show moreOsteopontin (OPN) plays a role in inflammation via recruitment of neutrophils and tissue remodeling. In this study, we investigated the distribution of OPN-expressing cells in the airway epithelium of normal lung tissue and that from patients with chronic obstructive pulmonary disease (COPD). OPN was detected on the epithelial cell surface of small airways and in scattered cells within the epithelial cell layer. Staining revealed higher OPN concentrations in tissue showing moderate to severe COPD compared to that in controls. In addition, OPN expression was confined to goblet and club cells, and was absent from ciliated and basal cells as detected via immunohistochemistry. However, OPN expression was up-regulated in submerged basal cells cultures exposed to cigarette smoke (CS) extract. Cell fractioning of air-liquid interface cultures revealed increased OPN production from basal compartment cells compared to that in luminal fraction cells. Furthermore, both constitutive and CS-induced expression of OPN decreased during differentiation. In contrast, cultures stimulated with interleukin (IL)-13 to promote goblet cell hyperplasia showed increased OPN production in response to CS exposure. These results indicate that the cellular composition of the airway epithelium plays an important role in OPN expression and that these levels may reflect disease endotypes in COPD. Show less
Rijn, A.L. van; Boheemen, S. van; Sidorov, I.; Carbo, E.C.; Pappas, N.; Mei, H.; ... ; Vries, J.J.C. de 2019
IntroductionExacerbations are major contributors to morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD), and respiratory bacterial and viral infections are an... Show moreIntroductionExacerbations are major contributors to morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD), and respiratory bacterial and viral infections are an important trigger. However, using conventional diagnostic techniques, a causative agent is not always found. Metagenomic next-generation sequencing (mNGS) allows analysis of the complete virome, but has not yet been applied in COPD exacerbations.ObjectivesTo study the respiratory virome in nasopharyngeal samples during COPD exacerbations using mNGS.Study design88 nasopharyngeal swabs from 63 patients from the Bergen COPD Exacerbation Study (2006-2010) were analysed by mNGS and in-house qPCR for respiratory viruses. Both DNA and RNA were sequenced simultaneously using an Illumina library preparation protocol with in-house adaptations.ResultsBy mNGS, 24/88 samples tested positive. Sensitivity and specificity, as compared with PCR, were 96% and 98% for diagnostic targets (23/24 and 1093/1120, respectively). Additional viral pathogens detected by mNGS were herpes simplex virus type 1 and coronavirus OC43. A positive correlation was found between Cq value and mNGS viral normalized species reads (log value) (p = 0.002). Patients with viral pathogens had lower percentages of bacteriophages (p<0.001). No correlation was found between viral reads and clinical markers.ConclusionsThe mNGS protocol used was highly sensitive and specific for semi-quantitative detection of respiratory viruses. Excellent negative predictive value implicates the power of mNGS to exclude any pathogenic respiratory viral infectious cause in one test, with consequences for clinical decision making. Reduced abundance of bacteriophages in COPD patients with viral pathogens implicates skewing of the virome during infection, with potential consequences for the bacterial populations, during infection. Show less
Aim: Biomarkers of acute respiratory distress syndrome (ARDS) after cardiac-surgery may help risk-stratification and management. Preoperative single-value proADM increases predictive capacity of... Show moreAim: Biomarkers of acute respiratory distress syndrome (ARDS) after cardiac-surgery may help risk-stratification and management. Preoperative single-value proADM increases predictive capacity of scoring-system EuroSCORE. To include the impact of surgery, we aim to assess the predictive value of the perioperative proADM-change on development of ARDS in 40 cardiac-surgery patients. Materials & methods: ProADM was measured in nine sequential blood samples. The Berlin definition of ARDS was used. For data-analyses, a multivariate model of EuroSCORE and perioperative proADM-change, linear mixed models and logistic regression were used. Results: Perioperative proADM-change was associated with ARDS after cardiac-surgery, and it was superior to EuroSCORE. A perioperative proADM-change >1.5 nmol/l could predict ARDS. Conclusion: Predicting post-surgery ARDS with perioperative proADM-change enables clinicians to intensify lung-protective interventions and individualized fluid therapy to minimize secondary injury. Show less
Turk, Y.; Sin, H.K.; Huisstede, A. van; Birnie, E.; Biter, U.; Hiemstra, P.S.; Braunstahl, G.J. 2019
Morbidly obese subjects with airflow obstruction who underwent laparoscopic bariatric surgery appear to have the greatest risk to develop complications. In a retrospective cohort study, we... Show moreMorbidly obese subjects with airflow obstruction who underwent laparoscopic bariatric surgery appear to have the greatest risk to develop complications. In a retrospective cohort study, we identified a waist circumference >= 120 cm, smoking history >= 5PY and history of obstructive lung disease as statistically significant predictors of airflow obstruction. The resulting algorithm, aimed to identify subjects with airflow obstruction before bariatric surgery, was validated in a prospective study. The algorithm was found to be effective in identifying patients with low risk of airflow obstruction (negative predictive value 94.7%). Airflow obstruction, however, was not associated with post-operative complications as we expected. In contrast, inspiratory capacity and the Epworth Sleepiness scale were more promising predictors for post-operative complications in subjects undergoing bariatric surgery. Show less
Ng-Blichfeldt, J.P.; Jong, T. de; Kortekaas, R.K.; Wu, X.H.; Lindner, M.; Guryev, V.; ... ; Gosens, R. 2019
Transforming growth factor-beta (TGF-beta)-induced fibroblast-to-myofibroblast differentiation contributes to remodeling in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis,... Show moreTransforming growth factor-beta (TGF-beta)-induced fibroblast-to-myofibroblast differentiation contributes to remodeling in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, but whether this impacts the ability of fibroblasts to support lung epithelial repair remains little explored. We pretreated human lung fibroblasts [primary (phFB) or MRC5 cells] with recombinant human TGF-beta to induce myofibroblast differentiation, then cocultured them with adult mouse lung epithelial cell adhesion molecule-positive cells (EpCAM(+)) to investigate their capacity to support epithelial organoid formation in vitro. While control phFB and MRC5 lung fibroblasts supported organoid formation of mouse EpCAM(+) cells, TGF-beta pretreatment of both phFB and MRC5 impaired organoid-supporting ability. We performed RNA sequencing of TGF beta-treated phFB. which revealed altered expression of key Wnt signaling pathway components and Wnt/beta-catenin target genes, and modulated expression of secreted factors involved in mesenchymal-epithelial signaling. TGF-beta profoundly skewed the transcriptional program induced by the Wnt/beta-catenin activator CHIR99021. Supplementing organoid culture media recombinant hepatocyte growth factor or fibroblast growth factor 7 promoted organoid formation when using TGF-beta pretreated fibroblasts. In conclusion, TGF-beta-induced myofibroblast differentiation results in Wnt/beta-catenin pathway skewing and impairs fibroblast ability to support epithelial repair likely through multiple mechanisms, including modulation of secreted growth factors. Show less
