Association between mosaic loss of chromosome Y and pulmonary fibrosis susceptibility and severity.

Background Pulmonary fibrosis (PF) is a rare lung disease with diverse pathogenesis and multiple interconnected underlying biological mechanisms. Mosaic loss of chromosome Y (mLOY) is one of the most common forms of acquired chromosome abnormality in men, which has been reported to be associated with increased risk of various chronic progressive diseases including fibrotic diseases. However, the exact role of mLOY in the development of PF remains elusive and to be elucidated. Methods: We adopted three complementary approaches to explore the role of mLOY in the pathogenesis of PF. We used copy number on chromosome Y to estimate mLOY comparing patients in PROFILE and gnomAD cohorts and between cases and control patients from the GE100KGP cohort. Correlation of mLOY with demographic and clinical variables was tested using patients from PROFILE cohort. Lung single-cell transcriptomic data were analysed to assess the cell types implicated in mLOY. We performed Mendelian randomisation to examine the causal relationship between mLOY, IPF, and telomere length. Results: The genetic analysis suggests that mLOY is found in PF from both case cohorts but when compared with an age matched population the effect is minimal (P = 0.0032). mLOY is related to age (P = 0.00021) and shorter telomere length (P = 0.0081) rather than PF severity or progression. Single-cell analysis indicates that mLOY appears to be found primarily in immune cells and appears to be related to presence and severity of fibrosis. Mendelian randomisation demonstrates that mLOY is not on the causal pathway for IPF, but partial evidence supports that telomere shortening is on the causal pathway for mLOY. Conclusion: Our study confirms the existence of mLOY in PF patients and suggests that mLOY is not a major driver of IPF. The combined evidence suggests a triangulation model where telomere shortening leads to both IPF and mLOY.

3D Bioprinting of Collagen-based Microfluidics for Engineering Fully-biologic Tissue Systems.

Microfluidic and organ-on-a-chip devices have improved the physiologic and translational relevance of in vitro systems in applications ranging from disease modeling to drug discovery and pharmacology. However, current manufacturing approaches have limitations in terms of materials used, non-native mechanical properties, patterning of extracellular matrix (ECM) and cells in 3D, and remodeling by cells into more complex tissues. We present a method to 3D bioprint ECM and cells into microfluidic collagen-based high-resolution internally perfusable scaffolds (CHIPS) that address these limitations, expand design complexity, and simplify fabrication. Additionally, CHIPS enable size-dependent diffusion of molecules out of perfusable channels into the surrounding device to support cell migration and remodeling, formation of capillary-like networks, and integration of secretory cell types to form a glucose-responsive, insulin-secreting pancreatic-like microphysiological system.

Shared genetic risk factors: implications for treatment of idiopathic pulmonary fibrosis and systemic hypertension.

The discovery of shared genetic associations, with sometimes different directions of effect, has implications for drug target discovery for idiopathic pulmonary fibrosis and systemic hypertension https://bit.ly/45IqbRv.

Parenchymal lung abnormalities following hospitalisation for COVID-19 and viral pneumonitis: a systematic review and meta-analysis.

INTRODUCTION: Persisting respiratory symptoms in COVID-19 survivors may be related to development of pulmonary fibrosis. We assessed the proportion of chest CT scans and pulmonary function tests consistent with parenchymal lung disease in the follow-up of people hospitalised with COVID-19 and viral pneumonitis. METHODS: Systematic review and random effects meta-analysis of proportions using studies of adults hospitalised with SARS-CoV-2, SARS-CoV, MERS-CoV or influenza pneumonia and followed up within 12 months. Searches performed in MEDLINE and Embase. Primary outcomes were proportion of radiological sequelae on CT scans; restrictive impairment; impaired gas transfer. Heterogeneity was explored in meta-regression. RESULTS: Ninety-five studies (98.9% observational) were included in qualitative synthesis, 70 were suitable for meta-analysis including 60 SARS-CoV-2 studies with a median follow-up of 3 months. In SARS-CoV-2, the overall estimated proportion of inflammatory sequelae was 50% during follow-up (0.50; 95% CI 0.41 to 0.58; I2=95%), fibrotic sequelae were estimated in 29% (0.29; 95% CI 0.22 to 0.37; I2=94.1%). Follow-up time was significantly associated with estimates of inflammatory sequelae (-0.036; 95% CI -0.068 to -0.004; p=0.029), associations with fibrotic sequelae did not reach significance (-0.021; 95% CI -0.051 to 0.009; p=0.176). Impaired gas transfer was estimated at 38% of lung function tests (0.38 95% CI 0.32 to 0.44; I2=92.1%), which was greater than restrictive impairment (0.17; 95% CI 0.13 to 0.23; I2=92.5%), neither were associated with follow-up time (p=0.207; p=0.864). DISCUSSION: Sequelae consistent with parenchymal lung disease were observed following COVID-19 and other viral pneumonitis. Estimates should be interpreted with caution due to high heterogeneity, differences in study casemix and initial severity. PROSPERO REGISTRATION NUMBER: CRD42020183139.

Three-Month FVC Change: A Trial Endpoint for Idiopathic Pulmonary Fibrosis Based on Individual Participant Data Meta-analysis.

Rationale: Novel therapies for idiopathic pulmonary fibrosis (IPF) are in development, but there remains uncertainty about the optimal trial endpoint. An earlier endpoint would enable assessment of a greater number of therapies in adaptive trial designs. Objectives: To determine whether short-term changes in FVC, DlCO, and six-minute-walk distance could act as surrogate endpoints to accelerate early-phase trials in IPF. Methods: Individual participant data (IPD) from IPF clinical trials were included in a two-step random-effects meta-analysis to determine whether baseline or 3-month changes in FVC, DlCO, and 6-minute-walk distance were associated with mortality or disease progression in placebo arms. Three-month and 12-month FVC decline endpoints were compared with treatment arm data from antifibrotic studies by meta-regression. Measurements and Main Results: IPD were available from 12 placebo cohorts totaling 1,819 participants, with baseline and 3-month changes in all physiological variables independently associated with poorer outcomes. Treatment data were available from six cohorts with 1,684 participants. For each 2.5% relative decline in FVC over 3 months, there was an associated 15% (adjusted hazard ratio, 1.15; 95% confidence interval [CI], 1.06-1.24; I2 = 59.4%) and 20% (adjusted hazard ratio, 1.20; 95% CI, 1.12-1.28; I2 = 18.0%) increased risk for mortality in untreated and treated individuals, respectively. An FVC change treatment effect was observed between treatment and placebo arms at 3 months (difference in FVC change of 42.9 ml; 95% CI, 24.0-61.8 ml; P < 0.001). Conclusions: IPD meta-analysis demonstrated that 3-month changes in physiological variables, particularly FVC, were associated with mortality among individuals with IPF. FVC change over 3 months may hold potential as a surrogate endpoint in IPF adaptive trials.

Systematic review and meta-analysis of anakinra, sarilumab, siltuximab and tocilizumab for COVID-19.

BACKGROUND: There is accumulating evidence for an overly activated immune response in severe COVID-19, with several studies exploring the therapeutic role of immunomodulation. Through systematic review and meta-analysis, we assess the effectiveness of specific interleukin inhibitors for the treatment of COVID-19. METHODS: Electronic databases were searched on 7 January 2021 to identify studies of immunomodulatory agents (anakinra, sarilumab, siltuximab and tocilizumab) for the treatment of COVID-19. The primary outcomes were severity on an Ordinal Scale measured at day 15 from intervention and days to hospital discharge. Key secondary endpoints included overall mortality. RESULTS: 71 studies totalling 22 058 patients were included, 6 were randomised trials. Most studies explored outcomes in patients who received tocilizumab (60/71). In prospective studies, tocilizumab was associated with improved unadjusted survival (risk ratio 0.83, 95% CI 0.72 to 0.96, I2=0.0%), but conclusive benefit was not demonstrated for other outcomes. In retrospective studies, tocilizumab was associated with less severe outcomes on an Ordinal Scale (generalised OR 1.34, 95% CI 1.10 to 1.64, I2=98%) and adjusted mortality risk (HR 0.52, 95% CI 0.41 to 0.66, I2=76.6%). The mean difference in duration of hospitalisation was 0.36 days (95% CI -0.07 to 0.80, I2=93.8%). There was substantial heterogeneity in retrospective studies, and estimates should be interpreted cautiously. Other immunomodulatory agents showed similar effects to tocilizumab, but insufficient data precluded meta-analysis by agent. CONCLUSION: Tocilizumab was associated with a lower relative risk of mortality in prospective studies, but effects were inconclusive for other outcomes. Current evidence for the efficacy of anakinra, siltuximab or sarilumab in COVID-19 is insufficient, with further studies urgently needed for conclusive findings. PROSPERO REGISTRATION NUMBER: CRD42020176375.

Antiproliferative effects of CDK4/6 inhibition in CDK4-amplified human liposarcoma in vitro and in vivo.

Well-differentiated/dedifferentiated liposarcomas (WD/DDLPS) are among the most common subtypes of soft tissue sarcomas. Conventional systemic chemotherapy has limited efficacy and novel therapeutic strategies are needed to achieve better outcomes for patients. The cyclin-dependent kinase 4 (CDK4) gene is highly amplified in more than 95% of WD/DDLPS. In this study, we explored the role of CDK4 and the effects of NVP-LEE011 (LEE011), a novel selective inhibitor of CDK4/CDK6, on a panel of human liposarcoma cell lines and primary tumor xenografts. We found that both CDK4 knockdown by siRNA and inhibition by LEE011 diminished retinoblastoma (RB) phosphorylation and dramatically decreased liposarcoma cell growth. Cell-cycle analysis demonstrated arrest at G0-G1. siRNA-mediated knockdown of RB rescued the inhibitory effects of LEE011, demonstrating that LEE011 decreased proliferation through RB. Oral administration of LEE011 to mice bearing human liposarcoma xenografts resulted in approximately 50% reduction in tumor (18)F-fluorodeoxyglucose uptake with decreased tumor biomarkers, including RB phosphorylation and bromodeoxyuridine incorporation in vivo. Continued treatment inhibited tumor growth or induced regression without detrimental effects on mouse weight. After prolonged continuous dosing, reestablishment of RB phosphorylation and cell-cycle progression was noted. These findings validate the critical role of CDK4 in maintaining liposarcoma proliferation through its ability to inactivate RB function, and suggest its potential function in the regulation of survival and metabolism of liposarcoma, supporting the rationale for clinical development of LEE011 for the treatment of WD/DDLPS.

Functional profiling of receptor tyrosine kinases and downstream signaling in human chondrosarcomas identifies pathways for rational targeted therapy.

PURPOSE: Chondrosarcomas are notoriously resistant to cytotoxic chemotherapeutic agents. We sought to identify critical signaling pathways that contribute to their survival and proliferation, and which may provide potential targets for rational therapeutic interventions. EXPERIMENTAL DESIGN: Activation of receptor tyrosine kinases (RTK) was surveyed using phospho-RTK arrays. S6 phosphorylation and NRAS mutational status were examined in chondrosarcoma primary tumor tissues. siRNA or small-molecule inhibitors against RTKs or downstream signaling proteins were applied to chondrosarcoma cells and changes in biochemical signaling, cell cycle, and cell viability were determined. In vivo antitumor activity of BEZ235, a phosphoinositide 3-kinase (PI3K)/mTOR inhibitor, was evaluated in a chondrosarcoma xenograft model. RESULTS: Several RTKs were identified as critical mediators of cell growth, but the RTK dependencies varied among cell lines. In exploration of downstream signaling pathways, strong S6 phosphorylation was found in 69% of conventional chondrosarcomas and 44% of dedifferentiated chondrosarcomas. Treatment with BEZ235 resulted in dramatic reduction in the growth of all chondrosarcoma cell lines. Tumor growth was similarly inhibited in a xenograft model of chondrosarcoma. In addition, chondrosarcoma cells with an NRAS mutation were sensitive to treatment with a mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor. Functional NRAS mutations were found in 12% of conventional central chondrosarcomas. CONCLUSIONS: RTKs are commonly activated in chondrosarcoma, but because of their considerable heterogeneity, targeted inhibition of the PI3K/mTOR pathway represents a rational therapeutic strategy. Chondrosarcomas with NRAS mutations may benefit from treatment with MEK inhibitors.