A Barrier to Defend - Models of Pulmonary Barrier to Study Acute Inflammatory Diseases

Pulmonary diseases represent four out of ten most common causes for worldwide mortality. Thus, pulmonary infections with subsequent inflammatory responses represent a major public health concern. The pulmonary barrier is a vulnerable entry site for several stress factors, including pathogens such as viruses, and bacteria, but also environmental factors e.g. toxins, air pollutants, as well as allergens. These pathogens or pathogen-associated molecular pattern and inflammatory agents e.g. damage-associated molecular pattern cause significant disturbances in the pulmonary barrier. The physiological and biological functions, as well as the architecture and homeostatic maintenance of the pulmonary barrier are highly complex. The airway epithelium, denoting the first pulmonary barrier, encompasses cells releasing a plethora of chemokines and cytokines, and is further covered with a mucus layer containing antimicrobial peptides, which are responsible for the pathogen clearance. Submucosal antigen-presenting cells and neutrophilic granulocytes are also involved in the defense mechanisms and counterregulation of pulmonary infections, and thus may directly affect the pulmonary barrier function. The detailed understanding of the pulmonary barrier including its architecture and functions is crucial for the diagnosis, prognosis, and therapeutic treatment strategies of pulmonary diseases. Thus, considering multiple side effects and limited efficacy of current therapeutic treatment strategies in patients with inflammatory diseases make experimental in vitro and in vivo models necessary to improving clinical therapy options. This review describes existing models for studyying the pulmonary barrier function under acute inflammatory conditions, which are meant to improve the translational approaches for outcome predictions, patient monitoring, and treatment decision-making. Copyright © 2022 Herminghaus, Kozlov, Szabó, Hantos, Gylstorff, Kuebart, Aghapour, Wissuwa, Walles, Walles, Coldewey and Relja

A Barrier to Defend - Models of Pulmonary Barrier to Study Acute Inflammatory Diseases

Pulmonary diseases represent four out of ten most common causes for worldwide mortality. Thus, pulmonary infections with subsequent inflammatory responses represent a major public health concern. The pulmonary barrier is a vulnerable entry site for several stress factors, including pathogens such as viruses, and bacteria, but also environmental factors e.g. toxins, air pollutants, as well as allergens. These pathogens or pathogen-associated molecular pattern and inflammatory agents e.g. damage-associated molecular pattern cause significant disturbances in the pulmonary barrier. The physiological and biological functions, as well as the architecture and homeostatic maintenance of the pulmonary barrier are highly complex. The airway epithelium, denoting the first pulmonary barrier, encompasses cells releasing a plethora of chemokines and cytokines, and is further covered with a mucus layer containing antimicrobial peptides, which are responsible for the pathogen clearance. Submucosal antigen-presenting cells and neutrophilic granulocytes are also involved in the defense mechanisms and counterregulation of pulmonary infections, and thus may directly affect the pulmonary barrier function. The detailed understanding of the pulmonary barrier including its architecture and functions is crucial for the diagnosis, prognosis, and therapeutic treatment strategies of pulmonary diseases. Thus, considering multiple side effects and limited efficacy of current therapeutic treatment strategies in patients with inflammatory diseases make experimental in vitro and in vivo models necessary to improving clinical therapy options. This review describes existing models for studyying the pulmonary barrier function under acute inflammatory conditions, which are meant to improve the translational approaches for outcome predictions, patient monitoring, and treatment decision-making

MiR-34a is differentially expressed in dorsal root ganglia in a rat model of chronic neuropathic pain

Introduction: Recent evidence shows that numerous microRNAs (miRNAs) regulate pain-related genes in chronic pain. The aim of the present study was to further explore the regulation of miRNAs and their effect on the expression of pain-associated target genes in experimental neuropathic pain. Methods: Male Wistar rats underwent chronic constriction injury (CCI) of the sciatic nerve or Sham procedure. After assessment of mechanical allodynia, the ipsilateral dorsal root ganglia (DRG) were harvested. MiRNA expression levels were analysed with Agilent microRNA microarrays and real time quantitative PCR. An interaction between miRNAs and pain-relevant genes was confirmed by luciferase assays. Western Blot analysis and ELISA were performed to evaluate protein expression, respectively. Results: Mechanical allodynia developed within 6 days after CCI. MiRNA-arrays revealed the differential expression of 49 miRNAs after 4 h, of 3 miRNAs after 1 d, of 26 miRNAs after 6 d and of 28 miRNAs after 12 d in the CCI group versus Sham. Time-dependent down regulation of miR-34a was verified by qPCR. Bioinformatic prediction revealed an interaction with several pain-relevant targets including voltage-gated sodium channel β2 subunit (SCN2B) and vesicle-associated membrane protein 2 (VAMP-2), both of which were subsequently confirmed by luciferase assay. VAMP-2 expression was statistically significantly increased 12 d after CCI. A non-significant upregulation of SCN2B in the DRG after CCI was confirmed by ELISA. Discussion: Peripheral mononeuropathic pain in rats was associated with distinct alterations of miRNA expression in the ipsilateral DRG. Notably, miR-34a was time-dependently down regulated. We validated SCN2B and VAMP-2 as new targets of miR-34a. While SCN2B expression was only marginally altered, VAMP-2 expression was increased. The present study underlines that the induction and maintenance of neuropathic pain is accompanied by expression changes of miRNAs in the peripheral nervous system, adding several previously unreported miRNAs, including miR-34a

Frequency and clinical correlates of somatic Ying Yang 1 mutations in sporadic insulinomas

Context: Insulinomas represent pancreatic neuroendocrine neoplasms that cause severe morbidity attributed to their often pronounced endocrine activity. Apart from hereditary forms such as multiple endocrine neoplasia type 1 (MEN-1), genetic causes for sporadic insulinoma development had remained obscure until recently. Applying next-generation sequencing methods, disease-causing genetic alterations have been identified in various endocrine tumors. Objective and Design: Paired tumor and blood DNA from eight patients with sporadic insulinomas (five females and two malignant tumors) were analyzed by whole-exome sequencing. After this initial analysis, Ying Yang 1 (YY1) mutation status was assessed in a larger cohort of 39 additional insulinomas (including eight malignant and one liver metastasis) from three German hospitals by targeted sequencing. The mutation status was correlated with various clinical parameters. Results: A range of one to 12 somatic genetic variants were identified by exome sequencing. A recurrent somatic Thr372Arg YY1 point mutation was detected in two patients of the initial cohort and four patients of the second cohort (total, six of 47; 13%). The presence of the mutation was associated with a trend toward higher age (63.5 y; IQR, 48.0-74.0 vs 45.0 y; IQR, 33.0-63.0; P = .05), and all affected patients were females (six of six; P = .04). All other clinical parameters, including the presence of malignancy and metastatic spread, tumor localization, and hypoglycemic episodes were not different between YY1-mutated and nonmutated tumor carriers. Conclusions: The somatic Thr372Arg YY1 mutation is a relevant finding in female patients with sporadic insulinomas. The prevalence of this mutation in this Caucasian population is considerably lower compared to that of a recently described Asian cohort