Biology subjects

Sidhaye, V. K.

Publications and source records attributed to Sidhaye, V. K..

5 recordsLinked to original sources

bioRxiv2023

Decreased fucosylation impacts epithelial integrity and increases risk for COPD.

COPD causes significant morbidity and mortality worldwide. Epithelial damage is fundamental to disease pathogenesis, although the mechanisms driving disease remain undefined. Published evidence from a COPD cohort (SPIROMICS) and confirmed in a second cohort (COPDgene) demonstrate a polymorphism in Fucosyltransferese-2 (FUT2) is a trans-pQTL for E-cadherin, which is critical in COPD pathogenesis. We found by MALDI-TOF analysis that FUT2 increased terminal fucosylation of E-cadherin. Using atomic force microscopy, we found that FUT2-dependent fucosylation enhanced E-cadherin-E-cadherin bond strength, mediating the improvement in monolayer integrity. Tracheal epithelial cells from Fut2-/- mice have reduced epithelial integrity, which is recovered with reconstitution of Fut2. Overexpression of FUT2 in COPD derived epithelia rescues barrier function. Fut2-/- mice show increased susceptibility in an elastase model of disease developing both emphysema and fibrosis. We propose this is due to the role of FUT2 in proliferation and cell differentiation. Overexpression of FUT2 significantly increased proliferation. Loss of Fut2 results in accumulation of Spc+ cells suggesting a failure of alveolar type 2 cells to undergo transdifferentiation to alveolar type 1. Using a combination of population data, genetically manipulated mouse models, and patient-derived cells, we present a novel mechanism by which post-translational modifications modulate tissue pathology and serve as a proof of concept for the development of a disease-modifying target in COPD.

cell biology↗

bioRxiv2022

HDAC6 inhibitor ACY-1083 shows lung epithelial protective features in COPD

Airway epithelial damage is a common feature in respiratory diseases such as COPD and has been suggested to drive inflammation and progression of disease. These features manifest as remodeling and destruction of lung epithelial characteristics including loss of small airways which contributes to chronic airway inflammation. Histone deacetylase 6 (HDAC6) has been shown to play a role in epithelial function and dysregulation, such as in cilia disassembly, epithelial to mesenchymal transition (EMT) and oxidative stress responses, and has been implicated in several diseases. We thus used ACY-1083, an inhibitor with high selectivity for HDAC6, and characterized its effects on epithelial function including epithelial disruption, cytokine production, remodeling, mucociliary clearance and cell characteristics. Primary lung epithelial air-liquid interface cultures from COPD patients were used and the impacts of TNF, TGF-{beta}, cigarette smoke and bacterial challenges on epithelial function in the presence and absence of ACY-1083 were tested. Each challenge increased the permeability of the epithelial barrier whilst ACY-1083 blocked this effect and even decreased permeability in the absence of challenge. TNF was also shown to increase production of cytokines and mucins, with ACY-1083 reducing the effect. We observed that COPD-relevant stimulations created damage to the epithelium as seen on immunohistochemistry sections and that treatment with ACY-1083 maintained an intact cell layer and preserved mucociliary function. Interestingly, there was no direct effect on ciliary beat frequency or tight junction proteins indicating other mechanisms for the protected epithelium. In summary, ACY-1083 shows protection of the respiratory epithelium during COPD-relevant challenges which indicates a future potential to restore epithelial structure and function to halt disease progression in clinical practice.

cell biology↗

bioRxiv2021

Knockout of E-cadherin in adult mouse epithelium results in emphysema and airway disease

Chronic obstructive pulmonary disease (COPD) is a devastating lung disease, characterized by a progressive decline in lung function, alveolar loss (emphysema), and airflow limitation due to excessive mucus secretion (chronic bronchitis), that can occur even after the injurious agent is removed. It is slated to rise to the 3rd leading cause of death due to chronic disease by 2030 globally, and the 4th leading cause of death due to chronic disease in the USA. While there is substantial evidence indicating loss of E-cadherin in the lung epithelium of patients with COPD, it is not known if this is causal to the disease. We investigated if loss of E-cadherin can result in lung disease using in both in vitro models of primary, differentiated human cells and in mouse models. Using a cell type-specific promoter using Cre/LoxP mice system to knock-out E- cadherin in ciliated and alveolar epithelial cell (Type 1 and Type 2) populations in adult mouse models, we determined that loss of E-cadherin caused airspace enlargement, as well as increased airway hyperresponsiveness indicating that it does have a causative role in causing COPD. Strategies to upregulate CDH1 (encodes for E-cadherin) in CHBEs and cigarette-smoke injured NHBEs can rescue the dysfunctional epithelium.

cell biology↗

bioRxiv2020

Adenine Nucleotide Translocase regulates the airway epithelium, mitochondrial metabolism and ciliary function

Airway hydration and ciliary function are critical to airway homeostasis and dysregulated in chronic obstructive lung disease (COPD). COPD is the 4th leading cause of death in the US and is impacted by cigarette smoking with no therapeutic options. We utilized a genetic selection approach in the amoeba Dictyostelium discoideum as a comparative discovery tool in lung biology to identify genetic protectors from cigarette smoke (CS). Adenine nucleotide translocase (ANT), a mitochondrial ADP/ATP transporter, was protective against CS in Dictyostelium and human bronchial epithelial cells. ANT2 gene expression is reduced in lung tissue from COPD patients and in a mouse smoking model. ANT1 and ANT2 overexpression resulted in enhanced oxidative respiration and ATP flux. In addition to ANTs presence in the mitochondria, ANT1 and ANT2 reside at the plasma membrane in airway epithelial cells and this localization plays a role in how ANTs regulate airway homeostasis. ANT2 overexpression stimulates airway surface liquid hydration by ATP and maintains ciliary beating after CS exposure, which are key functions of the airway. Our study highlights the potential of ANT modulation in protecting from dysfunctional mitochondrial metabolism, airway hydration, and ciliary motility in COPD.

cell biology↗

bioRxiv2020

Quantifying Epithelial Plasticity as a Platform to Reverse Epithelial Injury

Epithelial surfaces lining the lung serve as the primary environmental gaseous interface, and are subject to common life-limiting diseases, including COPD (Chronic Obstructive Pulmonary Disease). Despite the critical role of epithelial cells in pulmonary health and disease, quantitative models are lacking but are required given the large patient to patient variability to characterize the epithelial plasticity that follows injury. We have identified a series of assessments to quantitatively identify the changes that occur in the epithelium and to identify targets that reverse injury. The injured epithelium has decreased ciliary function and monolayer height, which in the case of cells derived from COPD patients results in an overall disorganization of structure. Injury causes the cells to shift to an unjammed state, with corresponding increases in the velocity correlation length implicating cell shape and stiffness as fundamental to the injury response. Specific inhibitors of actin polymerization (LatA), of MAPK/ERK kinase (U0126) and Nrf-2 pathway activation (CDDO-Me) push the epithelium back towards a jammed state with decreased cell movement and correlation length, as well as improve barrier function and CBF. These studies attest to cell intrinsic properties that allow for a transition to an unjammed state, and that quantitative phenotypic analysis can identify potential specific pharmacologic targets in a given patient and provide insight into basic mechanisms of cellular damage. One Sentence SummaryEnvironmental toxins undermine tissue integrity by manipulating transitions from jammed to unjammed states, thereby mimicking or inducing disease.

cell biology↗