Publications by authors named "Sushma Vishwakarma"

Purpose: Human ocular tissue banking plays an important part in the advancement of translational research for identifying the molecular processes involved in disease etiology and pathogenesis. Timely obtaining a good-quality ocular tissue from a cadaveric donor is exceedingly difficult, especially in remote areas, with a variable transportation time (within 12-24 h), raising concerns about RNA quality and its subsequent applications. Therefore, we assessed the utility of retinal tissues from cadaver donor and enucleated eyes based on the RNA quality and gene expression by real-time polymerase chain reaction (PCR).

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Chronic inflammation is a leading cause of neurodegeneration and vision loss in hyperglycemia-associated conditions such as diabetic retinopathy. Corticosteroid injections are widely used for treatment but suffer from limitations such as rapid drug clearance, short drug half-lives and frequent administration. While drug release from biomaterial carriers can overcome these shortcomings, evaluating the combined effects of corticosteroids and polymeric matrices under hyperglycemic stress is an important step towards aiding translation.

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Cellular hypoxia is a major cause of oxidative stress, culminating in neuronal damage in neurodegenerative diseases. Numerous ex vivo studies have implicated that hypoxia episodes leading to disruption of Ca homeostasis and redox status contribute to the progression of various neuropathologies and cell death. Isolation and maintenance of primary cell culture being cost-intensive, the details of the time course relationship between Ca overload, L-type Ca channel function, and neurite retraction under chronic and long-term hypoxia remain undefined.

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Background: Retinal neovascularization is the major cause of vision loss that affects both adults and young children including premature babies. It has been a major pathology in several retinal diseases like age-related macular degeneration (AMD), diabetic retinopathy (DR) and retinopathy of prematurity (ROP). Current treatment modalities such as anti-VEGF therapy, laser are not suitable for every patient and response to these therapies is highly variable.

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Electrospun fibrous meshes are widely used for tissue repair due to their ability to guide a host of cell responses including phenotypic differentiation and tissue maturation. A critical factor determining the eventual biological outcomes of mesh-based regeneration strategies is the early innate immune response following implantation. The natural healing process involves a sequence of tightly regulated, temporally varying and delicately balanced pro-/anti-inflammatory events which together promote mesh integration with host tissue.

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Long non-coding RNAs (lncRNAs) are emerging as key regulators of endothelial cell function. Here, we investigated the role of a novel vascular endothelial-associated lncRNA (VEAL2) in regulating endothelial permeability. Precise editing of veal2 loci in zebrafish (veal2 ) induced cranial hemorrhage.

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In this study, we offer new insights into the contrasting effects of electrospun fiber orientation on microglial polarization under normoxia and hypoxia, and establish for the first time, the intrinsically protective roles of electrospun meshes against hypoxia-induced microglial responses. First, resting microglia were cultured under normoxia on poly(caprolactone) fibers possessing two distinctly different fiber orientations. Matrix-guided differences in cell shape/orientation and differentially expressed Rho GTPases (RhoA, Rac1, Cdc42) were well-correlated with the randomly oriented fibers inducing a pro-inflammatory phenotype and the aligned fibers sustaining a resting phenotype.

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Article Synopsis
  • - Studies aimed at understanding glaucoma's development using mouse models need validation with human cells, leading to the exploration of human primary retinal cells (hPRCs) as a more accurate model for research and drug testing.
  • - hPRCs from patients exhibited a shift in marker expression as they grew, transitioning from showing glial markers to primarily expressing retinal ganglion cell (RGC)-specific markers, indicating they may function similarly to RGCs.
  • - The research found that certain glaucoma-related mutants of the OPTN gene increased cell death in hPRCs, while specific inhibitors were effective in reducing cell death, suggesting hPRCs could be useful for studying glaucoma and testing protective compounds.
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Inflammation plays a key role in the pathogenesis of retinal vascular diseases. We have shown earlier an increase in the activity of matrix metalloproteinases in the vitreous and tears of preterm born babies with retinopathy of prematurity (ROP) compared to those with no-ROP leading to a shift in the balance of angiogenic (vascular endothelial growth factor [VEGF], matrix metalloproteinase [MMPs], complement component [C3]) and anti-angiogenic (opticin, thrombospondin) in ROP eyes. We now confirmed that tear MMP levels in premature infants perfectly correlates with disease severity.

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Background: Traboulsi syndrome is a rare autosomal recessive genetic disorder. The present study aimed to identify the pathogenic variants in the gene responsible for a rare and unique presentation of Traboulsi syndrome associated with cardiac disorder.

Methodology: DNA was isolated from the blood samples from 3 clinically diagnosed Traboulsi syndrome patients (n = 3) after obtaining a prior-informed consent.

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The genes in the 9p21 locus ( & ) are widely associated with Primary open-angle glaucoma (POAG). However, the functional importance of this locus in POAG pathogenesis is still unexplored. This study investigated the role of axis in POAG.

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Fibrocellular membrane or epiretinal membrane (ERM) forms on the surface of the inner limiting membrane (ILM) in the inner retina and alters the structure and function of the retina. ERM formation is frequently observed in ocular inflammatory conditions, such as proliferative diabetic retinopathy (PDR) and retinal detachment (RD). Although peeling of the ERM is used as a surgical intervention, it can inadvertently distort the retina.

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Increasing incidences of multidrug-resistant (MDR) pathogens causing endophthalmitis threaten our ability to treat this condition, and the modulation of inflammatory responses by MDR bacteria is not known. In this study, using human microglia and retinal pigment epithelial (RPE) cells, we compare the inflammatory responses of sensitive (S-) and multidrug-resistant (MDR-) clinical isolates of . Infected cells were subjected to qPCR analysis, enzyme-linked immunosorbent assay (ELISA), and immunostaining to assess the expression of inflammatory mediators.

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The complement system plays a crucial role in retinal homeostasis. While the proteomic analysis of ocular tissues in diabetic retinopathy (DR) has shown the deposition of complement proteins, their exact role in the pathogenesis of DR is yet unclear. We performed a detailed investigation of the role of the complement system by evaluating the levels of major complement proteins including C3, C1q, C4b, Complement Factor B (CFB), and Complement Factor H (CFH) and their activated fragments from both the classical and alternative pathways in vitreous humor and serum samples from proliferative DR (PDR) patients and controls.

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The detailed mechanisms underlying oxidative stress that leads to neuroinflammation and neurodegeneration in retinal vascular conditions, including diabetic retinopathy, retinopathy of prematurity etc., remain largely unexplored mainly due to a lack of suitable disease models that can simulate the inherent neuron-glia interactions in human retina. Specifically, establishment of a mixed retinal culture (MRC) containing both neuron and glial cell types remains a challenge due to different conditions required for their optimal growth and differentiation.

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