Microscopic computed tomography with AI-CNN-powered image analysis: the path to phenotype bleomycin-induced lung injury.

Bleomycin (BLM)-induced lung injury in mice is a valuable model for investigating the molecular mechanisms that drive inflammation and fibrosis and for evaluating potential therapeutic approaches to treat the disease. Given high variability in the BLM model, it is critical to accurately phenotype the animals in the course of an experiment. In the present study, we aimed to demonstrate the utility of microscopic computed tomography (µCT) imaging combined with an artificial intelligence (AI)-convolutional neural network (CNN)-powered lung segmentation for rapid phenotyping of BLM mice. µCT was performed in freely breathing C57BL/6J mice under isoflurane anesthesia on days 7 and 21 after BLM administration. Terminal invasive lung function measurement and histological assessment of the left lung collagen content were conducted as well. µCT image analysis demonstrated gradual and time-dependent development of lung injury as evident by alterations in the lung density, air-to-tissue volume ratio, and lung aeration in mice treated with BLM. The right and left lung were unequally affected. µCT-derived parameters such as lung density, air-to-tissue volume ratio, and nonaerated lung volume correlated well with the invasive lung function measurement and left lung collagen content. Our study demonstrates the utility of AI-CNN-powered µCT image analysis for rapid and accurate phenotyping of BLM mice in the course of disease development and progression.NEW & NOTEWORTHY Microscopic computed tomography (µCT) imaging combined with an artificial intelligence (AI)-convolutional neural network (CNN)-powered lung segmentation is a rapid and powerful tool for noninvasive phenotyping of bleomycin mice over the course of the disease. This, in turn, allows earlier and more reliable identification of therapeutic effects of new drug candidates, ultimately leading to the reduction of unnecessary procedures in animals in pharmacological research.

Inflammation following acute myocardial infarction: Multiple players, dynamic roles, and novel therapeutic opportunities.

Acute myocardial infarction (AMI) and the heart failure that often follows, are major causes of death and disability worldwide. As such, new therapies are required to limit myocardial infarct (MI) size, prevent adverse left ventricular (LV) remodeling, and reduce the onset of heart failure following AMI. The inflammatory response to AMI, plays a critical role in determining MI size, and a persistent pro-inflammatory reaction can contribute to adverse post-MI LV remodeling, making inflammation an important therapeutic target for improving outcomes following AMI. In this article, we provide an overview of the multiple players (and their dynamic roles) involved in the complex inflammatory response to AMI and subsequent LV remodeling, and highlight future opportunities for targeting inflammation as a therapeutic strategy for limiting MI size, preventing adverse LV remodeling, and reducing heart failure in AMI patients.

A Comprehensive Analysis of Fibroblast Growth Factor Receptor 2b Signaling on Epithelial Tip Progenitor Cells During Early Mouse Lung Branching Morphogenesis.

This study demonstrates that FGF10/FGFR2b signaling on distal epithelial progenitor cells, via ß-catenin/EP300, controls, through a comprehensive set of developmental genes, morphogenesis, and differentiation. Fibroblast growth factor (FGF) 10 signaling through FGF receptor 2b (FGFR2b) is mandatory during early lung development as the deletion of either the ligand or the receptor leads to lung agenesis. However, this drastic phenotype previously hampered characterization of the primary biological activities, immediate downstream targets and mechanisms of action. Through the use of a dominant negative transgenic mouse model (Rosa26rtTA; tet(o)sFgfr2b), we conditionally inhibited FGF10 signaling in vivo in E12.5 embryonic lungs via doxycycline IP injection to pregnant females, and in vitro by culturing control and experimental lungs with doxycycline. The impact on branching morphogenesis 9 h after doxycycline administration was analyzed by morphometry, fluorescence and electron microscopy. Gene arrays at 6 and 9 h following doxycycline administration were carried out. The relationship between FGF10 and ß-catenin signaling was also analyzed through in vitro experiments using IQ1, a pharmacological inhibitor of ß-catenin/EP300 transcriptional activity. Loss of FGF10 signaling did not impact proliferation or survival, but affected both adherens junctions (up-regulation of E-cadherin), and basement membrane organization (increased laminin). Gene arrays identified multiple direct targets of FGF10, including main transcription factors. Immunofluorescence showed a down-regulation of the distal epithelial marker SOX9 and mis-expression distally of the proximal marker SOX2. Staining for the transcriptionally-active form of ß-catenin showed a reduction in experimental vs. control lungs. In vitro experiments using IQ1 phenocopied the impacts of blocking FGF10. This study demonstrates that FGF10/FGFR2b signaling on distal epithelial progenitor cells via ß-catenin/EP300 controls, through a comprehensive set of developmental genes, cell adhesion, and differentiation.

MicroRNA-142 is a multifaceted regulator in organogenesis, homeostasis, and disease.

Over the past decade, microRNA-142 (miR-142) is emerging as a major regulator of cell fate decision in the hematopoietic system. However, miR-142 is expressed in many other tissues, and recent evidence suggests that it may play a more pleiotropic role during embryonic development. In addition, miR-142 has been shown to play important functions in disease. miR-142 displays a functional role in cancer, virus infection, inflammation, and immune tolerance. Both a guide strand (miR-142-3p) and passenger strand (miR-142-5p) are generated from the miR-142 hairpin. miR-142-3p and -5p display overlapping but also independent target genes. Loss of function mouse models (genetrap, global knock out [KO], and conditional KO) have been reported and support the important role of miR-142 in different biological processes. This review will summarize the abundant literature already available for miR-142 and will lay the foundation for future works on this important microRNA. Developmental Dynamics 246:285-290, 2017. © 2016 Wiley Periodicals, Inc.

Human adipose-derived stem cells stimulate neuroregeneration.

Traumatic brain injuries and degenerative neurological disorders such as Alzheimer's dementia, Parkinson's disease, amyotrophic lateral sclerosis and many others are characterized by loss of brain cells and supporting structures. Restoring microanatomy and function using stem cells is a promising therapeutic approach. Among the many various sources, adipose-derived stem cells (ADSCs) are one of the most easily harvested alternatives, they multiply rapidly, and they demonstrate low immunogenicity with an ability to differentiate into several cell types. The objective of this study was to evaluate the effect of xenotransplanted human ADSCs on post-traumatic regeneration of rat sciatic nerve. Peripheral reconstruction following complete sciatic transection and autonerve grafting was complemented by intra-operative injection of hADSCs into the proximal and distal stumps. The injury caused gliosis and apoptosis of sensory neurons in the lumbar 5 (L5) ganglia in the control rodents; however, animals treated with hADSCs demonstrated a smaller amount of cellular loss. Formation of amputation neuroma, which hinders axonal repair, was less prominent in the experimental group, and immunohistochemical analysis of myelin basic protein showed good myelination 65 days after surgery. At this point, control groups still exhibited high levels of microglia/macrophage-specific marker Iba-1 and proliferating cell nuclear antigen, the mark of an ongoing inflammation and incomplete axonal growth 2 months after the injury. This report demonstrates that hADSCs promote neuronal survival in the spinal ganglion, fuel axonal repair and stimulate the regeneration of peripheral nerves.

Generation and Validation of miR-142 Knock Out Mice.

microRNA-142 (miR-142) is an important regulator of many biological processes and associated signaling pathways during embryonic development, homeostasis and disease. The miR-142 hairpin gives rise to the "guide strand" miR-142-3p and the sister "passenger" strand miR-142-5p. miR-142-3p has been shown to play critical, non-redundant functions in the development of the hematopoietic lineage. We have recently reported that miR-142-3p is critical for the control of Wnt signaling in the mesenchyme of the developing lung. miR-142-5p has been proposed to control adaptive growth in cardiomyocytes postnatally and its increase is associated with extensive apoptosis and cardiac dysfunction in a murine heart failure model. Using homologous recombination, we now report the generation and validation of miR-142-null mice. miR-142-null mice show a significant decrease in th expression levels of both the 3p and 5p isoforms. The expression of Bzrap1, a gene immediately flanking miR-142 is not altered while the expression of a long non-coding RNA embedded within the miR-142 gene is decreased. miR-142-null newborn pups appear normal and are normally represented indicating absence of embryonic lethality. At embryonic day 18.5, miR-142-null lungs display increased Wnt signaling associated with the up-regulation of Apc and p300, two previously reported targets of miR-142-3p and -5p, respectively. Adult miR-142-null animals display impaired hematopoietic lineage formation identical to previously reported miR-142 gene trap knockdown mice. We report, for the first time, the homologous recombination-based miR-142-null mice that will be useful for the scientific community working on the diverse biological functions of miR-142.

Quantitative proteome analysis of alveolar type-II cells reveals a connection of integrin receptor subunits beta 2/6 and WNT signaling.

Alveolar type-II cells (ATII cells) are lung progenitor cells responsible for regeneration of alveolar epithelium during homeostatic turnover and in response to injury. Characterization of ATII cells will have a profound impact on our understanding and treatment of lung disease. The identification of novel ATII cell-surface proteins can be used for sorting and enrichment of these cells for further characterization. Here we combined a high-resolution mass spectrometry-based membrane proteomic approach using lungs of the SILAC mice with an Affymetrix microarray-based transcriptome analysis of ATII cells. We identified 16 proteins that are enriched in the membrane fraction of ATII cells and whose genes are highly expressed in these cells. Interestingly, we confirmed our data for two of these genes, integrin beta 2 and 6 (Itgb2 and Itgb6), by qRT-PCR expression analysis and Western blot analysis of protein extracts. Moreover, flow cytometry and immunohistochemistry in adult lung revealed that ITGB2 and ITGB6 are present in subpopulations of surfactant-associated-protein-C-positive cells, suggesting the existence of different types of ATII cells. Furthermore, analysis of the Itgb2(-/-) mice showed that Itgb2 is required for proper WNT signaling regulation in the lung.