Publications by authors named "Shireen Mentor"

The blood-brain barrier (BBB) is a robust interface between the blood and the central nervous system. Barrier type endothelium is able to limit paracellular (PC) movement, relegating molecular flux to the transendothelial pathways of brain endothelial cells (BECs). It is, therefore, apparent that any leakage the PC shunts would effectively nullify the regulation of molecular flux across the transcellular pathways.

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Scanning electron microscopy (SEM) provides a technical platform for nanoscopic mapping of biological structures. Correct preparation of SEM samples can provide an unprecedented understanding of the nexus between cellular morphology and topography. This comparative study critically examines two coating methods for preparing biological samples for scanning electron microscopy, while also providing novel advice on how to prepare in vitro epithelial or endothelial samples for high-resolution scanning-electron microscopy (HR-SEM).

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The blood-brain barrier (BBB) is fundamental in maintaining central nervous system (CNS) homeostasis by regulating the chemical environment of the underlying brain parenchyma. Brain endothelial cells (BECs) constitute the anatomical and functional basis of the BBB. Communication between adjacent BECs is critical for establishing BBB integrity, and knowledge of its nanoscopic landscape will contribute to our understanding of how juxtaposed zones of tight-junction protein interactions between BECs are aligned.

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The brain capillary endothelium is highly regulatory, maintaining the chemical stability of the brain's microenvironment. The role of cytoskeletal proteins in tethering nanotubules (TENTs) during barrier-genesis was investigated using the established immortalized mouse brain endothelial cell line (bEnd5) as an blood-brain barrier (BBB) model. The morphology of bEnd5 cells was evaluated using both high-resolution scanning electron microscopy and immunofluorescence to evaluate treatment with depolymerizing agents Cytochalasin D for F-actin filaments and Nocodazole for α-tubulin microtubules.

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High-resolution electron microscopy (HREM) imaging of the blood-brain barrier (BBB), is a promising modality for investigating the dynamic morphological interplay underpinning BBB development. The successful establishment of BBB integrity is grounded in the brain endothelial cells (BEC's) ability to occlude its paracellular spaces of brain capillaries through the expression of the intercellular tight junction (TJ) proteins. The impermeability of these paracellular spaces are crucial in the regulation of transcellular transport systems to achieve homeostasis of the central nervous system.

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Traumatic brain injury (TBI) is a major health problem in the United States, which affects about 1.7 million people each year. Glial cells, T-cells, and mast cells perform specific protective functions in different regions of the brain for the recovery of cognitive and motor functions after central nervous system (CNS) injuries including TBI.

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Despite significant advancements in the field of molecular neurobiology especially neuroinflammation and neurodegeneration, the highly complex molecular mechanisms underlying neurodegenerative diseases remain elusive. As a result, the development of the next generation neurotherapeutics has experienced a considerable lag phase. Recent advancements in the field of genome editing offer a new template for dissecting the precise molecular pathways underlying the complex neurodegenerative disorders.

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Nanoparticles (NPs) have gained importance in addressing drug delivery challenges across biological barriers. Here, we reformulated pentamidine, a drug used to treat Human African Trypanosomiasis (HAT) in polymer based nanoparticles and liposomes and compared their capability to enhance pentamidine penetration across blood brain barrier (BBB). Size, polydispersity index, zeta potential, morphology, pentamidine loading and drug release profiles were determined by various methods.

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The pathological form of amyloid beta (Aβ) peptide is shown to be toxic to the mitochondria and implicates this organelle in the progression and pathogenesis of Alzheimer's disease (AD). Mitochondria are dynamic structures constantly undergoing fission and fusion, and altering their shape and size while traveling through neurons. Mitochondrial fission (Drp1, Fis1) and fusion (OPA1, Mfn1, and Mfn2) proteins are balanced in healthy neuronal cells.

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Mast cell activation plays an important role in stress-mediated disease pathogenesis. Chronic stress cause or exacerbate aging and age-dependent neurodegenerative diseases. The severity of inflammatory diseases is worsened by the stress.

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Oxidative stress in the brain microvasculature is a common characteristic in models of cerebrovascular disease. Considering the effects of reactive oxygen species activity in vascular-derived insults, it is naturally prudent to hypothesize those interventions inhibiting reactive oxygen species activity, such as antioxidant supplementation, may be beneficial for cerebrovascular disease. Hyper doses of antioxidant supplements, and foods with high antioxidant concentrations, are commonly used as an ongoing remedial and 'over-the-counter' treatments for most seasonal ailments.

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