Publications by authors named "Sumaya Hamadmad"

Ibudilast, an inhibitor of macrophage migration inhibitory factor (MIF) and phosphodiesterase (PDE), has been recently shown to have neuroprotective effects in a variety of neurologic diseases. We utilize a chick excitotoxic retinal damage model to investigate ibudilast's potential to protect retinal neurons. Using single cell RNA-sequencing (scRNA-seq), we find that MIF, putative MIF receptors CD74 and CD44, and several PDEs are upregulated in different retinal cells during damage.

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Objectives: The chick is rapidly becoming a standardized preclinical model in vision research to study mechanisms of ocular disease. We seek to comprehensively evaluate the N-methyl-D-aspartate (NMDA) model of excitotoxic retinal damage using multimodal imaging, functional, and histologic approaches in NMDA-damaged, vehicle-treated, and undamaged chicks.

Methods: Chicks were either left undamaged in both eyes or were injected with NMDA in the left eye and saline (vehicle) in the right eye.

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Purpose: Mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling is neuroprotective in some retinal damage models but its role in neuronal survival during retinal detachment (RD) is unclear. In addition, serous RDs are a prevalent side effect of MEK inhibitors (MEKi), blocking MAPK/ERK signaling for treatment of certain cancers. We tested the hypothesis that MEKi treatment in experimental RD would increase photoreceptor death.

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Article Synopsis
  • Nuclear co-localization labels, crucial for ocular research, require effective quantitation methods to assess cell death, with the TUNEL assay being the standard for apoptosis detection.
  • A new ImageJ-based automated multichannel thresholding (MCT) method was developed, validated against established techniques in a retinal detachment model, showing strong correlation with minimal differences.
  • The MCT method demonstrated reliable performance compared to existing methods, providing a promising tool for accurate quantification of nuclear markers without staining issues.
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Erythropoietin (Epo) receptor (EpoR) is expressed in several cancer cell lines, and the functional consequence of this expression is under extensive study. In this study, we used a cervical cancer cell line in which EpoR was first found to be expressed and to correlate with the severity of the disease. We demonstrate that Epo is a chemoattractant for these cancer cells, enhancing their migration under serum-starved conditions.

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Erythropoietin (Epo) is a cytokine that is required for the survival of erythroid progenitors through interaction with its receptor on the surface of these cells. Recent studies showed that erythropoietin receptor (EpoR) is expressed on many cancer cells. The factors that govern EpoR expression on the cell surface are poorly understood.

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Erythropoietin (Epo) acts through the erythropoietin receptor, a member of the type-1 cytokine receptor family, to influence survival, proliferation, and differentiation of erythroid progenitors. Epo stimulation of factor-dependent 32D cells results in phosphorylation of many proteins, including Janus kinase (Jak) 2, signal transducer and activator of transcription (Stat) 5, and extracellular signal-regulated kinase (Erk). Some of Epo-activated signaling proteins require isoprenylation, either farnesylation or geranylgeranylation, for post-translational modification.

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