Slow hydrogel matrix degradation enhances salivary gland mimetic phenotype.

We recently developed a salivary gland tissue mimetic (SGm), comprised of salivary gland cells encapsulated in matrix metalloproteinase (MMP)-degradable poly(ethylene glycol) hydrogels within arrays of ∼320 µm diameter spherical cavities molded in PDMS. The SGm provides a functional and physiologically relevant platform well-suited to high-throughput drug screening for radioprotective compounds. However, the utility of the SGm would benefit from improved retention of acinar cell phenotype and function.

Encapsulation of Primary Salivary Gland Acinar Cell Clusters and Intercalated Ducts (AIDUCs) within Matrix Metalloproteinase (MMP)-Degradable Hydrogels to Maintain Tissue Structure and Function.

Progress in the development of salivary gland regenerative strategies is limited by poor maintenance of the secretory function of salivary gland cells (SGCs) in vitro. To reduce the precipitous loss of secretory function, a modified approach to isolate intact acinar cell clusters and intercalated ducts (AIDUCs), rather than commonly used single cell suspension, is investigated. This isolation approach yields AIDUCs that maintain many of the cell-cell and cell-matrix interactions of intact glands.

The critical role of collagen VI in lung development and chronic lung disease.

Type VI collagen (collagen VI) is an obligate extracellular matrix component found mainly in the basement membrane region of many mammalian tissues and organs, including skeletal muscle and throughout the respiratory system. Collagen VI is probably most recognized in medicine as the genetic cause of a spectrum of muscular dystrophies, including Ullrich Congenital Myopathy and Bethlem Myopathy. Collagen VI is thought to contribute to myopathy, at least in part, by mediating muscle fiber integrity by anchoring myoblasts to the muscle basement membrane.

3D iPSC modeling of the retinal pigment epithelium-choriocapillaris complex identifies factors involved in the pathology of macular degeneration.

The retinal pigment epithelium (RPE)-choriocapillaris (CC) complex in the eye is compromised in age-related macular degeneration (AMD) and related macular dystrophies (MDs), yet in vitro models of RPE-CC complex that enable investigation of AMD/MD pathophysiology are lacking. By incorporating iPSC-derived cells into a hydrogel-based extracellular matrix, we developed a 3D RPE-CC model that recapitulates key features of both healthy and AMD/MD eyes and provides modular control over RPE and CC layers. Using this 3D RPE-CC model, we demonstrated that both RPE- and mesenchyme-secreted factors are necessary for the formation of fenestrated CC-like vasculature.

Development of a functional salivary gland tissue chip with potential for high-content drug screening.

Radiation therapy for head and neck cancers causes salivary gland dysfunction leading to permanent xerostomia. Limited progress in the discovery of new therapeutic strategies is attributed to the lack of in vitro models that mimic salivary gland function and allow high-throughput drug screening. We address this limitation by combining engineered extracellular matrices with microbubble (MB) array technology to develop functional tissue mimetics for mouse and human salivary glands.

Lymphocyte-Specific Biomarkers Associated With Preterm Birth and Bronchopulmonary Dysplasia.

Many premature babies who are born with neonatal respiratory distress syndrome (RDS) go on to develop Bronchopulmonary Dysplasia (BPD) and later Post-Prematurity Respiratory Disease (PRD) at one year corrected age, characterized by persistent or recurrent lower respiratory tract symptoms frequently related to inflammation and viral infection. Transcriptomic profiles were generated from sorted peripheral blood CD8+ T cells of preterm and full-term infants enrolled with consent in the NHLBI Prematurity and Respiratory Outcomes Program (PROP) at the University of Rochester and the University at Buffalo. We identified outcome-related gene expression patterns following standard methods to identify markers for oxygen utilization and BPD as outcomes in extremely premature infants.

Rare Pulmonary Connective Tissue Type Mast Cells Regulate Lung Endothelial Cell Angiogenesis.

Within the human lung, mast cells typically reside adjacent to the conducting airway and assume a mucosal phenotype (MC). In rare pathologic conditions, connective tissue phenotype mast cells (MCs) can be found in the lung parenchyma. MCs accumulate in the lungs of infants with severe bronchopulmonary dysplasia, a chronic lung disease associated with preterm birth, which is characterized by pulmonary vascular dysmorphia.

Collagen VI Deficiency Results in Structural Abnormalities in the Mouse Lung.

Collagen VI (COL6) is known for its role in a spectrum of congenital muscular dystrophies, which are often accompanied by respiratory dysfunction. However, little is known regarding the function of COL6 in the lung. We confirmed the presence of COL6 throughout the basement membrane region of mouse lung tissue.

CX3CR1 as a respiratory syncytial virus receptor in pediatric human lung.

Background: Data on the host factors that contribute to infection of young children by respiratory syncytial virus (RSV) are limited. The human chemokine receptor, CX3CR1, has recently been implicated as an RSV receptor. Here we evaluate a role for CX3CR1 in pediatric lung RSV infections.

A novel in vitro model of primary human pediatric lung epithelial cells.

Background: Current in vitro human lung epithelial cell models derived from adult tissues may not accurately represent all attributes that define homeostatic and disease mechanisms relevant to the pediatric lung.

Methods: We report methods for growing and differentiating primary Pediatric Human Lung Epithelial (PHLE) cells from organ donor infant lung tissues. We use immunohistochemistry, flow cytometry, quantitative RT-PCR, and single cell RNA sequencing (scRNAseq) analysis to characterize the cellular and transcriptional heterogeneity of PHLE cells.

Type VI collagen promotes lung epithelial cell spreading and wound-closure.

Basement membrane (BM) is an essential part of the extracellular matrix (ECM) that plays a crucial role in mechanical support and signaling to epithelial cells during lung development, homeostasis and repair. Abnormal composition and remodeling of the lung ECM have been associated with developmental abnormalities observed in multiple pediatric and adult respiratory diseases. Collagen VI (COL6) is a well-studied muscle BM component, but its role in the lung and its effect on pulmonary epithelium is largely undetermined.

Interpreting in vitro micronucleus positive results: simple biomarker matrix discriminates clastogens, aneugens, and misleading positive agents.

The specificity of in vitro mammalian cell genotoxicity assays is low, as they yield a high incidence of positive results that are not observed in animal genotoxicity and carcinogenicity tests, that is, "misleading" or "irrelevant" positives. We set out to develop a rapid and effective follow-up testing strategy that would predict whether apparent in vitro micronucleus-inducing effects are due to a clastogenic, aneugenic, or secondary irrelevant mode(s) of action. Priority was given to biomarkers that could be multiplexed onto flow cytometric acquisition of micronucleus frequencies, or that could be accomplished in parallel using a homogeneous-type assay.

Interlaboratory Pig-a gene mutation assay trial: Studies of 1,3-propane sultone with immunomagnetic enrichment of mutant erythrocytes.

An international collaborative trial was established to systematically investigate the merits and limitations of a rat in vivo Pig-a gene mutation assay. The product of this gene is essential for anchoring CD59 to the plasma membrane, and mutations in this gene are identified by flow cytometric quantification of circulating erythrocytes without cell surface CD59 expression. Initial interlaboratory data from rats treated with several potent mutagens have been informative, but the time required for those flow cytometric analyses (∼20 min per sample) limited the number of cells that could be interrogated for the mutant phenotype.