MicroRNA Profiling of the Inflammatory Response after Early and Late Asthmatic Reaction.

A high proportion of house dust mite (HDM)-allergic asthmatics suffer from both an early asthmatic reaction (EAR) and a late asthmatic reaction (LAR) which follows it. In these patients, allergic inflammation is more relevant. MiRNAs have been shown to play an important role in the regulation of asthma's pathology. The aim of this study was to analyze the miRNA profile in patients with mild asthma and an HDM allergy after bronchial allergen provocation (BAP). Seventeen patients with EAR/no LAR and 17 patients with EAR plus LAR, determined by a significant fall in FEV1 after BAP, were differentially analyzed. As expected, patients with EAR plus LAR showed a more pronounced allergic inflammation and FEV1 delta drop after 24 h. NGS-miRNA analysis identified the down-regulation of miR-15a-5p, miR-15b-5p, and miR-374a-5p after BAP with the highest significance in patients with EAR plus LAR, which were negatively correlated with eNO and the maximum decrease in FEV1. These miRNAs have shared targets like CCND1, VEGFA, and GSK3B, which are known to be involved in airway remodeling, basement membrane thickening, and Extracellular Matrix deposition. NGS-profiling identified miRNAs involved in the inflammatory response after BAP with HDM extract, which might be useful to predict a LAR.

Dual Role of microRNA-146a in Experimental Inflammation in Human Pulmonary Epithelial and Immune Cells and Expression in Inflammatory Lung Diseases.

microRNA (miR)-146a emerges as a promising post-transcriptional regulator in various inflammatory diseases with different roles for the two isoforms miR-146a-5p and miR-146a-3p. The present study aimed to examine the dual role of miR-146a-5p and miR-146a 3p in the modulation of inflammation in human pulmonary epithelial and immune cells in vitro as well as their expression in patients with inflammatory lung diseases. Experimental inflammation in human A549, HL60, and THP1 via the NF-kB pathway resulted in the major upregulation of miR-146a-5p and miR-146a-3p expression, which was partly cell-specific. Modulation by transfection with miRNA mimics and inhibitors demonstrated an anti-inflammatory effect of miR-146a-5p and a pro-inflammatory effect of miR-146a-3p, respectively. A mutual interference between miR-146a-5p and miR-146a-3p was observed, with miR-146a-5p exerting a predominant influence. In vivo NGS analyses revealed an upregulation of miR-146a-3p in the blood of patients with cystic fibrosis and bronchiolitis obliterans, while miR-146a-5p levels were downregulated or unchanged compared to controls. The reverse pattern was observed in patients with SARS-CoV-2 infection. In conclusion, miR-146a-5p and miR-146a-3p are two distinct but interconnected miRNA isoforms with opposing functions in inflammation regulation. Understanding their interaction provides important insights into the progression and persistence of inflammatory lung diseases and might provide potential therapeutic options.

Association between Polyunsaturated Fatty Acid Profile and Bronchial Inflammation in Bronchiolitis Obliterans.

Introduction: Bronchiolitis obliterans (BO) is a chronic lung disease, which occurs after an insult to the lower airways, in particular after airway infections or after stem cell transplantation, and which results in persistent inflammation. N-3 and n-6 polyunsaturated fatty acids (PUFA) have been shown to influence the inflammatory processes in chronic inflammatory conditions. Since BO is maintained by persistent pulmonary inflammation, a disbalanced n-6/n-3 fatty acid profile could support the inflammatory process in patients with BO and therefore, could become an approach to new therapeutic options. Methods: Twenty-five patients with BO (age: 13; 7-39) and 26 healthy controls (age: 19; 7-31) participated in the study. Lung function (forced viral capacity (FVC), forced expiratory volume 1 (FEV1), residual volume (RV)), and lung clearance index (LCI) were measured. Induced sputum was analyzed for cytology and cytokine levels (IL-1ß, IL-6, IL-8, TNF-α) using cytometric bead array (CBA). The PUFA profile was determined in the serum and induced sputum by gas chromatography. Results: Patients presented with significantly lower FVC and FEV1 as well as higher RV and LCI measurements compared to the control group. Apart from a massive airway inflammation indicated by elevated numbers of total cells and neutrophils, the CBA analysis showed significantly increased levels of IL-1ß, IL-6, and IL-8. The analysis of PUFA in sputum and serum revealed a significant difference in the ratio between the n-6 PUFA arachidonic acid (AA) and the n-3 PUFA docosahexaenoic acid (DHA) (AA : DHA). Furthermore, the AA : DHA ratio significantly correlated with the inflammatory cytokines in induced sputum. Conclusion: Lung function in BO is significantly impaired and associated with uncontrolled neutrophil-dominated airway inflammation. Furthermore, the imbalance in the AA/DHA ratio in favor of n-6 PUFA demonstrates a pro-inflammatory microenvironment in the cell membrane, which correlates with the inflammatory cytokines in induced sputum and might be an option for an anti-inflammatory therapy in BO.

The incidence and type of cancer in patients with ataxia-telangiectasia via a retrospective single-centre study.

Ataxia-telangiectasia (A-T) is a hereditary immune system disorder with neurodegeneration. Its first neurologic symptoms include ataxic gait in early childhood, with slowly progressive cerebellar ataxia, oculomotor apraxia, oculocutaneous telangiectasia, and progressive muscle weakness. Neonatal screening for severe T-cell deficiency was recently found to diagnose A-T patients with a significantly reduced naïve T-cell pool. Our study includes 69 A-T patients between 8 January 2002 and 1 December 2019. Nineteen cases of cancer were diagnosed in 17 patients (25%), with a median overall survival [OS; 95% cumulative indcidence (CI)] of 26·9 years for the entire cohort. The 15-year OS of 82·5% (72-95%) was significantly decreased among A-T patients with malignancies, who had a median OS of 2·11 years, with a two-year-estimated OS of 50·7% (31-82%). Haematological malignancies were the major causes of death within the initial years of life with a 15 times increased risk for death [HR (95% CI): 6·9 (3·1-15.2), P < 0·001] upon malignancy diagnosis. Male patients with A-T are at a higher cancer risk than their female counterparts. This manuscript highlights the need for cancer surveillance and prevention, as well as optimal treatment in this cohort.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia.

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978).

The MiR-320 Family Is Strongly Downregulated in Patients with COVID-19 Induced Severe Respiratory Failure.

A high incidence of thromboembolic events associated with high mortality has been reported in severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infections with respiratory failure. The present study characterized post-transcriptional gene regulation by global microRNA (miRNA) expression in relation to activated coagulation and inflammation in 21 critically ill SARS-CoV-2 patients. The cohort consisted of patients with moderate respiratory failure (n = 11) and severe respiratory failure (n = 10) at an acute stage (day 0-3) and in the later course of the disease (>7 days). All patients needed supplemental oxygen and severe patients were defined by the requirement of positive pressure ventilation (intubation). Levels of D-dimers, activated partial thromboplastin time (aPTT), C-reactive protein (CRP), and interleukin (IL)-6 were significantly higher in patients with severe compared with moderate respiratory failure. Concurrently, next generation sequencing (NGS) analysis demonstrated increased dysregulation of miRNA expression with progression of disease severity connected to extreme downregulation of miR-320a, miR-320b and miR-320c. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed involvement in the Hippo signaling pathway, the transforming growth factor (TGF)-ß signaling pathway and in the regulation of adherens junctions. The expression of all miR-320 family members was significantly correlated with CRP, IL-6, and D-dimer levels. In conclusion, our analysis underlines the importance of thromboembolic processes in patients with respiratory failure and emphasizes miRNA-320s as potential biomarkers for severe progressive SARS-CoV-2 infection.

Ataxia telangiectasia alters the ApoB and reelin pathway.

Autosomal recessive ataxia telangiectasia (A-T) is characterized by radiosensitivity, immunodeficiency, and cerebellar neurodegeneration. A-T is caused by inactivating mutations in the ataxia telangiectasiamutated (ATM) gene, a serine-threonine protein kinase involved in DNA damage response and excitatory neurotransmission. The selective vulnerability of cerebellar Purkinje neurons (PN) to A-T is not well understood. Employing global proteomic profiling of cerebrospinal fluid from patients at ages around 15 years, we detected reduced calbindin, reelin, cerebellin-1, cerebellin-3, protocadherin fat 2, sempahorin 7A, and increased apolipoprotein B and J peptides. Bioinformatic enrichment was observed for pathways of lipoproteins, endocytosis, extracellular matrix receptor interaction, peptidase activity, adhesion, calcium binding, and complement immunity. This seemed important since secretion of reelin from glutamatergic afferent axons is crucial for PN lipoprotein receptor endocytosis and lipid signaling. Reelin expression is downregulated by irradiation and reelin/ApoB mutations are known causes of ataxia. Validation efforts in 2-month-old Atm-/- mice before onset of motor deficits confirmed cerebellar transcript reductions for reelin receptors Apoer2/Vldlr with increases for their ligands Apoe/Apoh and cholesterol 24-hydroxylase Cyp46a1. Concomitant dysregulations were found for Vglut2/Sema7a as climbing fiber markers, glutamate receptors like Grin2b, and calcium homeostasis factors (Atp2b2, Calb1, Itpr1), while factors involved in DNA damage, oxidative stress, neuroinflammation, and cell adhesion were normal at this stage. Quantitative immunoblots confirmed ApoB and ApoJ increases and VLDLR reduction in cerebellar tissue at the age of 2 months. These findings show that ApoB excess and reelin signaling deficits reflect the neurodegeneration in A-T in a sensitive and specific way. As extracellular factors, apolipoproteins and their cargo such as vitamin E may be useful for neuroprotective interventions.

Altered mucosal immune response after acute lung injury in a murine model of Ataxia Telangiectasia.

BACKGROUND: Ataxia telangiectasia (A-T) is a rare but devastating and progressive disorder characterized by cerebellar dysfunction, lymphoreticular malignancies and recurrent sinopulmonary infections. In A-T, disease of the respiratory system causes significant morbidity and is a frequent cause of death. METHODS: We used a self-limited murine model of hydrochloric acid-induced acute lung injury (ALI) to determine the inflammatory answer due to mucosal injury in Atm (A-T mutated)- deficient mice (Atm(-/-)). RESULTS: ATM deficiency increased peak lung inflammation as demonstrated by bronchoalveolar lavage fluid (BALF) neutrophils and lymphocytes and increased levels of BALF pro-inflammatory cytokines (e.g. IL-6, TNF). Furthermore, bronchial epithelial damage after ALI was increased in Atm(-/-) mice. ATM deficiency increased airway resistance and tissue compliance before ALI was performed. CONCLUSIONS: Together, these findings indicate that ATM plays a key role in inflammatory response after airway mucosal injury.

In Cerebellar Atrophy of 12-Month-Old ATM-Null Mice, Transcriptome Upregulations Concern Most Neurotransmission and Neuropeptide Pathways, While Downregulations Affect Prominently Itpr1, Usp2 and Non-Coding RNA.

The autosomal recessive disorder Ataxia-Telangiectasia is caused by a dysfunction of the stress response protein, ATM. In the nucleus of proliferating cells, ATM senses DNA double-strand breaks and coordinates their repair. This role explains T-cell dysfunction and tumour risk. However, it remains unclear whether this function is relevant for postmitotic neurons and underlies cerebellar atrophy, since ATM is cytoplasmic in postmitotic neurons. Here, we used ATM-null mice that survived early immune deficits via bone-marrow transplantation, and that reached initial neurodegeneration stages at 12 months of age. Global cerebellar transcriptomics demonstrated that ATM depletion triggered upregulations in most neurotransmission and neuropeptide systems. Downregulated transcripts were found for the ATM interactome component Usp2, many non-coding RNAs, ataxia genes Itpr1, Grid2, immediate early genes and immunity factors. Allelic splice changes affected prominently the neuropeptide machinery, e.g., Oprm1. Validation experiments with stressors were performed in human neuroblastoma cells, where ATM was localised only to cytoplasm, similar to the brain. Effect confirmation in SH-SY5Y cells occurred after ATM depletion and osmotic stress better than nutrient/oxidative stress, but not after ATM kinase inhibition or DNA stressor bleomycin. Overall, we provide pioneer observations from a faithful A-T mouse model, which suggest general changes in synaptic and dense-core vesicle stress adaptation.

Epigenetic regulation of inflammation by microRNAs in post-infectious bronchiolitis obliterans.

OBJECTIVES: Post-infectious bronchiolitis obliterans (PiBO) is a rare, chronic disease initiated by severe infection and followed by perpetuating inflammation and obliteration of the small airways. MicroRNAs (miRNAs) have been proposed to play a central role as epigenetic regulators, which control resolution and prevent the uncontrolled progress of inflammation. The aim of this study was to define biomarkers on the level of post-transcriptional gene regulation in order to characterise PiBO. METHODS: A total of 39 patients with well-defined PiBO and 31 controls from two centres, Barcelona, Spain, and Frankfurt, Germany, were analysed by next-generation sequencing (NGS). The evaluation of the biological targets of the miRNAs was performed by pathway enrichment analysis and protein-protein interaction network analysis respectively. RESULTS: Patients with PiBO had significantly lower lung function values and increased airway inflammation in induced sputum as indicated by total cell counts, neutrophils, IL-1ß, IL-6, IL-8 and TGF-ß compared to controls.Next-generation sequencing analysis revealed a total of 22 dysregulated miRNAs, which passed significance threshold for Padj ≤ 0.001 with 17 being upregulated and 5 being downregulated. Of these dysregulated miRNAs, miR-335-5p, miR-186-5p, miR-30b-5p and miR-30c-5p were further validated using qRT-PCR. Interestingly, these miRNAs are functionally implicated in cytokine-cytokine receptor interaction, TGF-ß signalling and FoxO signalling pathway and significantly correlated with lung function values (FEV1). CONCLUSION: Our results demonstrate an aberrant miRNA expression profile in PiBO, which impacts pathways responsible for the regulation of inflammation and fibrosis. The defined miRNAs are useful biomarkers and should be assessed as potential target in the field of miRNA therapeutics.

Survival and Functional Immune Reconstitution After Haploidentical Stem Cell Transplantation in Atm-Deficient Mice.

Hematopoietic stem cell transplantation (HSCT) has been proposed as a promising therapeutic opportunity to improve immunity and prevent hematologic malignancies in Ataxia-telangiectasia (A-T). However, experience in the transplantation strategy for A-T patients is still scarce. The aim of this study was to investigate whether different approaches of HSCT are feasible in regard to graft versus host response and sufficient concerning functional immune reconstitution. Atm-deficient mice were treated with a clinically relevant non-myeloablative host-conditioning regimen and transplanted with CD90.2-depleted, green fluorescent protein (GFP)-expressing, and ataxia telangiectasia mutated (ATM)-competent bone marrow donor cells in a syngeneic, haploidentical or allogeneic setting. Like syngeneic HSCT, haploidentical HSCT, but not allogeneic HSCT extended the lifespan of Atm-deficient mice through the reduction of thymic tumors and normalized T-cell numbers. Donor-derived splenocytes isolated from transplanted Atm-deficient mice filled the gap of cell loss in the naïve T-cell population and raised CD4 cell functionality up to wild-type level. Interestingly, HSCT using heterozygous donor cells let to a significantly improved survival of Atm-deficient mice and increased CD4 cell numbers as well as CD4 cell functionality equivalent to HSCT using with wild-type donor cells. Our data provided evidence that haploidentical HSCT could be a feasible strategy for A-T, possibly even if the donor is heterozygous for ATM. However, this basic research cannot substitute any research in humans.

Tracking of Infused Mesenchymal Stem Cells in Injured Pulmonary Tissue in Atm-Deficient Mice.

Pulmonary failure is the main cause of morbidity and mortality in the human chromosomal instability syndrome Ataxia-telangiectasia (A-T). Major phenotypes include recurrent respiratory tract infections and bronchiectasis, aspiration, respiratory muscle abnormalities, interstitial lung disease, and pulmonary fibrosis. At present, no effective pulmonary therapy for A-T exists. Cell therapy using adipose-derived mesenchymal stromal/stem cells (ASCs) might be a promising approach for tissue regeneration. The aim of the present project was to investigate whether ASCs migrate into the injured lung parenchyma of Atm-deficient mice as an indication of incipient tissue damage during A-T. Therefore, ASCs isolated from luciferase transgenic mice (mASCs) were intravenously transplanted into Atm-deficient and wild-type mice. Retention kinetics of the cells were monitored using in vivo bioluminescence imaging (BLI) and completed by subsequent verification using quantitative real-time polymerase chain reaction (qRT-PCR). The in vivo imaging and the qPCR results demonstrated migration accompanied by a significantly longer retention time of transplanted mASCs in the lung parenchyma of Atm-deficient mice compared to wild type mice. In conclusion, our study suggests incipient damage in the lung parenchyma of Atm-deficient mice. In addition, our data further demonstrate that a combination of luciferase-based PCR together with BLI is a pivotal tool for tracking mASCs after transplantation in models of inflammatory lung diseases such as A-T.

Hematopoietic Stem Cell Transplantation Restores Naïve T-Cell Populations in Atm-Deficient Mice and in Preemptively Treated Patients With Ataxia-Telangiectasia.

Background: Ataxia-telangiectasia (A-T) is a multisystem disorder with progressive cerebellar ataxia, immunodeficiency, chromosomal instability, and increased cancer susceptibility. Cellular immunodeficiency is based on naïve CD4+ and CD8+ T-cell lymphopenia. Hematopoietic stem cell transplantation (HSCT) offers a potential to cure immunodeficiency and cancer due to restoration of the lymphopoietic system. The aim of this investigation was to analyze the effect of HSCT on naïve CD4+ as well as CD8+ T-cell numbers in A-T. Methods: We analyzed total numbers of peripheral naïve (CD45RA+CD62L+) and memory (CD45RO+CD62L-) CD4+ and CD8+ T-cells of 32 A-T patients. Naïve (CD62LhighCD44low) and memory (CD62LlowCD44high) T-cells were also measured in Atm-deficient mice before and after HSCT with GFP-expressing bone marrow derived hematopoietic stem cells. In addition, we analyzed T-cells in the peripheral blood of two A-T patients after HLA-identic allogeneic HSCT. Results: Like in humans, naïve CD4+ as well as naïve CD8+ lymphocytes were decreased in Atm-deficient mice. HSCT significantly inhibited thymic lymphomas and increased survival time in these animals. Donor cell chimerism increased up to more than 50% 6 months after HSCT accompanied by a significant increase of naïve CD4 and CD8 T-cell subpopulations, but not of memory T-cells. This finding was also identified in the blood of the A-T patients after HSCT. Conclusion: HSCT seems to be a feasible strategy to overcome immunodeficiency and might be a conceivable strategy to avoid T-cell driven cancer in A-T at higher risk for malignancy. Naïve CD4 and CD8 T-cells counts are suitable markers for monitoring immune reconstitution post-HSCT. However, risks and benefits of HSCT in A-T have to be properly weighted.

Oxidative stress-driven pulmonary inflammation and fibrosis in a mouse model of human ataxia-telangiectasia.

Lung failure is responsible for significant morbidity and is a frequent cause of death in ataxia-telangiectasia (A-T). Disturbance in the redox balance of alveolar epithelial cells must be considered as a causal factor for respiratory disease in A-T. To investigate bronchoalveolar sensitivity to reactive oxygen species (ROS) and ROS-induced DNA damage, we used bleomycin (BLM) to induce experimental inflammation and fibrotic changes in the Atm-deficient mouse model. BLM or saline was administered by oropharyngeal instillation into the lung of Atm-deficient mice and wild-type mice. Mice underwent pulmonary function testing at days 0, 9, and 28, and bronchoalveolar lavage (BAL) was analysed for cell distribution and cytokines. Lung tissue was analysed by histochemistry. BLM administration resulted in a tremendous increase in lung inflammation and fibrotic changes in the lung tissue of Atm-deficient mice and was accompanied by irreversible deterioration of lung function. ATM (ataxia telangiectasia mutated) deficiency resulted in reduced cell viability, a delay in the resolution of γH2AX expression and a significant increase in intracellular ROS in pulmonary epithelial cells after BLM treatment. This was confirmed in the human epithelial cell line A549 treated with the ATM-kinase inhibitor KU55933. Our results demonstrate high bronchoalveolar sensitivity to ROS and ROS-induced DNA damage in the Atm-deficient mouse model and support the hypothesis that ATM plays a pivotal role in the control of oxidative stress-driven lung inflammation and fibrosis.