Biology subjects

Dhamodaran, K.

Publications and source records attributed to Dhamodaran, K..

3 recordsLinked to original sources

bioRxiv2024

Inhibition of pterygium cell fibrosis by the Rho kinase inhibitor

Pterygium is an ocular disease in which the conjunctival tissue invades the cornea. When the pterygium tissue reaches the pupillary region, the visual function of the patient is affected. Currently, surgical removal is the only effective treatment. However, the recurrence rate of pterygium after surgery can be high. Pterygium is also a health disparity issue since it is more prevalent in the Hispanic and Latino American population. In this study, we determined if the Rho kinase inhibitor can be used to prevent pterygium recurrence since its anti-fibrosis effects have been reported in other cell and tissue types. We cultured primary pterygium cells from pterygium tissues from Hispanic and Latino American, African American, Caucasian, and Asian donors, and used those cells for viability assays, scratch assays, migration assays, and immunostaining of F-actin, fibronectin, collagen I and smooth muscle actin. We found that the Rho kinase inhibitor Y27632 decreased cell viability, wound healing, cell migration, as well as the expression of extracellular matrix and myofibroblast markers in cultured pterygium cells. We believe that Rho kinases inhibitors are a potential post-surgical treatment to prevent pterygium recurrence.

pharmacology and toxicology↗

bioRxiv2024

Characterization, enrichment, and computational modeling of cross-linked actin networks in trabecular meshwork cells

PurposeCross-linked actin networks (CLANs) are prevalent in the glaucomatous trabecular meshwork (TM), yet their role in ocular hypertension remains unclear. We used a human TM cell line that spontaneously forms fluorescently-labeled CLANs (GTM3L) to explore the origin of CLANs, developed techniques to increase CLAN incidence in GMT3L cells, and computationally studied the biomechanical properties of CLAN-containing cells. MethodsGTM3L cells were fluorescently sorted for viral copy number analysis. CLAN incidence was increased by (i) differential sorting of cells by adhesion, (ii) cell deswelling, and (iii) cell selection based on cell stiffness. GTM3L cells were also cultured on glass or soft hydrogel to determine substrate stiffness effects on CLAN incidence. Computational models were constructed to mimic and study the biomechanical properties of CLANs. ResultsAll GTM3L cells had an average of 1 viral copy per cell. LifeAct-GFP expression level did not affect CLAN incidence rate, but CLAN rate was increased from [~]0.28% to [~]50% by a combination of adhesion selection, cell deswelling, and cell stiffness-based sorting. Further, GTM3L cells formed more CLANs on a stiff vs. a soft substrate. Computational modeling predicted that CLANs contribute to higher cell stiffness, including increased resistance of the nucleus to tensile stress when CLANs are physically linked to the nucleus. ConclusionsIt is possible to greatly enhance CLAN incidence in GTM3L cells. CLANs are mechanosensitive structures that affect cell biomechanical properties. Further research is needed to determine the effect of CLANs on TM biomechanics and mechanobiology as well as the etiology of CLAN formation in the TM.

cell biology↗

bioRxiv2023

Characterization of extracellular matrix deposited by segmental trabecular meshwork cells

Biophysical and biochemical attributes of the extracellular matrix are major determinants of cell fate in homeostasis and disease. Ocular hypertension and glaucoma are diseases where the trabecular meshwork tissue responsible for aqueous humor egress becomes stiffer accompanied by changes in its matrisome in a segmental manner with regions of high or low flow. Prior studies demonstrate these alterations in the matrix are dynamic in response to age and pressure changes. The underlying reason for segmentation or differential response to pressure and stiffening are unknown. This is largely due to a lack of appropriate models (in vitro or ex vivo) to study this phenomena. In this study, we characterize the biomechanical attributes, matrisome, and incidence of crosslinks in the matrix deposited by primary cells isolated from segmental flow regions and when treated with glucocorticosteroid. Data demonstrate that matrix deposited by cells from low flow regions are stiffer and exhibit a greater number of immature and mature crosslinks, and that these are exacerbated in the presence of steroid. We also show a differential response of high or low flow cells to steroid via changes observed in the matrix composition. We conclude that although a mechanistic basis for matrix stiffness was undetermined in this study, it is a viable tool to study cell-matrix interactions and further our understanding of trabecular meshwork pathobiology.

cell biology↗