Biology subjects

Birla, R.

Publications and source records attributed to Birla, R..

5 recordsLinked to original sources

bioRxiv2025

Shear Stress Conditioning Promotes a Pro-Inflammatory Response in Porcine Endocardial Endothelial Cells

PURPOSEDiscrete subaortic stenosis (DSS) is a congenital heart disease characterized by a narrowing of the passage below the aortic valve in the left ventricular outflow tract (LVOT) [1]. While endocardial endothelial cells (EECs) are known to play a role in DSS, the response of these cells to shear stress is not known. In this study, we hypothesize that the response of EECs to shear stress in the LVOT is a mediator of DSS. METHODSTo test this hypothesis, we conditioned porcine EECs to controlled shear stress regimes using cone and plate bioreactors. Subsequently, we quantified the concentration of proinflammatory cytokine in the conditioned media using the Luminex assay. Bulk-RNA sequencing was used to quantify changes in the genotype of the shear stress conditioned EECs. RESULTSThe expression of CD31 was knocked down and subsequently, the changes in release of shear stress induced proinflammatory cytokines released by EECs quantified using the Luminex assay. The results of these studies show that the inflammatory cytokines were highly selected in the conditioning medium, and under bioreactor treatment the cell activated the PI3K-AKT and TNF-a signaling, which also triggered the other immune cell responses though Th1, Th2 and Th17 cell differentiation pathways. Furthermore, CD31 was identified as a mediator of the pro-inflammatory response of shear stress conditioned EECs. CONCLUSIONSThe studies provide a clear link between shear stress, and the subsequent proinflammatory response of EECs as a mediator of DSS.

bioengineering↗

bioRxiv2025

Shear Stress Modulates Inflammatory Responses in Porcine Endothelial Cells Contributing to the Fibrotic Response of Porcine Cardiac Fibroblasts

This study is focused on discrete subaortic stenosis (DSS) which is a congenital heart disease resulting in the formation of fibrotic tissue in the left ventricular outflow track of pediatric patients [1]. The pathogenesis of the molecular mechanism resulting in the formation of the fibrotic tissue remains unknown and is the focus of this study. We hypothesized the cytokine released in response to wall shear stress act on the fibroblasts to promote the formation of the fibrotic membrane and subsequently, DSS. To test this study hypothesis, porcine endocardial endothelial cells were cultured within cone and plate bioreactors, designed to replicate the wall shear stress observed in the left ventricular outflow track of DSS patients. Conditioned media was collected as a function of shear stress magnitude and used to condition porcine cardiac fibroblasts. We used an extensive set of end-point metrics to characterize fibroblast phenotype to include bulk-RNA sequencing, RT-qPCR, cell viability and immunofluorescence. The results of this study demonstrate that shear stress-conditioned media from porcine EEC releases a defined cocktail of cytokines that provide the trigger to program the fibrotic response during DSS. These results provide specific molecular targets that can be developed into a therapeutic strategy for patients with DSS and provide a solution to an otherwise challenging disease to manage.

bioengineering↗

bioRxiv2024

Insights into the Molecular Mechanism of Pulmonary Vein Stenosis in Pediatric Patients

BackgroundPediatric pulmonary vein stenosis (PVS) is associated with substantial morbidity and mortality for the subset of patients with recurrent or progressive disease. The molecular mechanisms underlying the development and trajectory of PVS remain unclear. This study characterizes the transcriptome of clinical and phenotypic subtypes of PVS. MethodsBulk RNA sequencing analysis was performed on human pulmonary vein tissue samples obtained from surgical interventions for pediatric patients with PVS. Transcriptomic profiles were compared for primary versus post-repair PVS as well as aggressive versus non-aggressive clinical phenotypes. Principal component analysis was performed, the differential gene expression quantified, and pathway analysis conducted based on gene ontology, KEGG and Reactome. ResultsWhen comparing AggPPVS vs NonAggPPVS, differences were noted in the genes associated in extracellular matrix regulation and PIEZO1, a mechanosensitive receptor present in endothelial cells. In addition, there were notable changes in cardiac muscle contractility, calcium handling, respiratory and energy metabolism. These results point to a potential mechanism for aggressive PPVS phenotype, due to an overexpression of PIEOZ1 in response to elevated shear stress, subsequent activation of intracellular signaling pathways and leading to reduced contractility and intracellular calcium transients with cardiomyocytes. ConclusionsThe result of this study suggests that aggressive PPVS phenotype is caused by an increase in PIEZO1 expression and subsequent changes in extracellular matrix production, heart muscle contractility and changes in calcium transients within cardiomyocytes. These results provide a potential target for therapeutic invention for primary PPVS by inhibiting the activity of PIEZO1. This could potentially reduce morbidity in this patient population.

genomics↗

bioRxiv2024

Development of a Novel Method to Fabricate Highly Functional Human Purkinje Networks

BACKGROUNDIn this study, we present a method to bioengineer functional Purkinje networks using recent advances in laser-based bioprinting. METHODSA custom bioink as formulated using optimized concentrations of polyethylene glycol diacrylate (PEGDA), gelatin methacryloyl (GELMA), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), and tartrazine. A standard triangle language (STL) model of Purkinje networks was developed based on the mammalian Purkinje network mapped out using India ink staining. A commercial bioprinter, the Lumen X, from CellInk, was used to bioprint Purkinje networks. The biocompatibility of the bioprinted Purkinje networks was tested using iPSCs from healthy donors. Negative molds of the Purkinje networks were designed to simulate interaction between Purkinje cells and adjacent cardiomyocytes using different degrees of overlap between the two cell types. The negative molds were also shown to be biocompatible, based on the culture of iPSCs derived from healthy donors. RESULTSWe were able to successfully bioprint over 100 Purkinje networks and demonstrate biocompatibility with iPSCs for up to 7 days. Three different configurations of the negative molds were designed and fabricated and all three shown to be biocompatible with iPSCs for up to 7 days. A co-culture system was developed by placing the Purkinje networks in proximity to the negative molds for all three configurations designed. CONCLUSIONOur results demonstrate the ability to bioprint Purkinje networks and molds and provide an in vitro system to study the functional interaction between Purkinje cells and adjacent cardiomyocytes.

bioengineering↗

bioRxiv2023

Genomic and Proteomic Analysis of Patients with Reoccurring Discrete Subaortic Stenosis

Discrete subaortic stenosis (DSS) is a pediatric condition in which a fibrotic membrane forms within the left ventricular outflow track. The fibrotic membrane is removed surgically; however, there is a high rate of reoccurrence which requires a second surgery. There are currently no tools available to predict the risk of reoccurrence in DSS patients, a limitation addressed by this study. In this study, we analyzed resected fibrotic membranes for DSS patients at the time of first surgery for non-recurrent and recurrent patients, and at the time of second surgery for recurrent patients. RNA-sequencing was conducted to obtain a global screen of changes in RNA expression while mass spectrometry was used to obtain a global screen of changes in protein expression. The results from the RNA-sequencing and mass spectrometry provide valuable insight into genes and the proteins that are differentially regulated in recurrent vs non-recurrent DSS patients.

molecular biology↗