Life Sciences Commons^™

Heightened Levels Of Microvesicle Particles Resulting From Combination Of Ethanol And Thermal Burn Injury, Chad Alan Brewer

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Ethanol (EtOH), in combination with thermal burn injury, is a clinically significant problem resulting in an increase in morbidity and mortality due to acute multi-organ toxicity from excess systemic cytokine release. This intoxicated thermal burn affects close to 50% of the total numbers of hospital-admitted burn patients and currently has no standard treatment. However, using in vitro cellular and in vivo murine models, our group has provided data implicating the augmented production of the lipid mediator Platelet-activating factor (PAF) in keratinocytes in response to intoxicated thermal burn injury in the subsequent pathology. Of importance, our group has demonstrated that activation …

Replication Stress Induced By The Ribonucleotide Reductase Inhibitors Guanazole, Triapine, And Gemcitabine In Fission Yeast, Mashael Yahya A Alyahya

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Replication stress can be produced by various exogenous or endogenous factors that perturb the movement of replication forks. To overcome the stress, the cells provoke the DNA replication checkpoint to mobilize several pathways to protect the forks, maintain genome integrity, and promote cell survival. Defects in the replication checkpoint cause forks collapse, leading to chromosomal DNA damage or cell death. Although the replication checkpoint is crucial for genome integrity in all eukaryotes, the underlying mechanisms remains to be fully understood. To investigate the mechanisms of DRC, hydroxyurea (HU), an established inhibitor of ribonucleotide reductase (RNR), has been widely used in …

Ahr-Mediated Transcriptional Regulation Of The Human Immunoglobulin Hs1.2 Enhancer, Sydney White

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The 3'IGHRR is thought to be responsible for the transcription of the immunoglobulin heavy chain (IGH) gene locus, which is essential for the production of antibodies. The human 3’IGHRR, which is duplicated in humans, contains the hs3, hs4, and hs1.2 enhancers. Additionally, the hs1.2 enhancer is polymorphic in humans and consists of a 53 bp invariant sequence that can be repeated one to four times. Previous experiments in a mouse and human B-cell line model have shown that the high affinity AhR ligand and environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce hs1.2 enhancer activity in an AhR-dependent manner. The AhR is …

The Effect Of Circadian Clock Modulation On Cisplatin Cytotoxicity, Nadeen Nibal Ahmad Anabtawi

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Cisplatin is a DNA damage-based chemotherapeutic drug widely used to treat various types of cancers; however, the treatment's toxicity restricts its efficiency. Studies have shown that the circadian rhythm controls the DNA damage response and affects the repair pathways of cisplatin-induced DNA damage. Circadian clock modulation, therefore, has been proposed to be a potential mechanism for enhancing cisplatin tolerability. Here we used clock-enhancing molecules to evaluate the effect of pharmacological clock modulation on cisplatin cytotoxicity. Using cultured human cell lines, cisplatin cytotoxicity was found to be attenuated following treatment with circadian-enhancing molecules KS15 and SR8278. Moreover, the protein and mRNA …

Stress-Induced Senescence In Human Dermal Fibroblasts : Effects Of Creatine And Nicotinamide Post Stress Treatment, Venkata Sravya Arikatla

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In skin connective tissue, dermal fibroblasts appear to be the most prevalent cell type. They are in charge of making the extracellular matrix that makes up the skin's connective tissue, and also involved in wound healing. Moreover, they produce Insulin-like growth factor-1 (IGF-1) which helps in activation of Insulin growth factor-1 receptor (IGF-1R). This receptor helps to control cell proliferation and responses to DNA-damaging substances such as UVB radiation, reactive oxygen species (ROS), and therapeutic drugs. According to our findings, lack of IGF-1 expression in the dermis of elderly patients due to fibroblast senescence (senescence is characterized by which cells …

The Protective Effects Of Mir-210 Modified Endothelial Progenitor Cells Released Exosomes In Hypoxia/Reoxygenation Injured Neurons, Sri Meghana Yerrapragada

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Endothelial progenitor cells (EPCs) have been shown to provide beneficial effects on oxidative stress. Exosomes (EXs) released from these stem cells could be one of the major contributors, as they are known to convey the benefit of one cell to another cell via microRNAs (miRNA). At first, we determined that EPCs release more EXs when they are serum-starved for 48 hours., and by determining the microRNA-210 (miR-210) levels in the EXs, we found that miRNA is being transferred from cells to EXs. Meanwhile, miR-210 is gaining popularity in reducing elevated oxidative stress levels. In this study, we investigated the role …

Functions Of Atr Kinase In Terminally Differentiated Human Epidermal Keratinocyles And In Human Ex-Vivo Skin After Exposure To Ultraviolet B Radiation, Vivek Shashank Nag Gogusetti

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The functions of Ataxia telangiectasia and Rad-3 related protein (ATR) is very much important in a cell, as it is a DNA damage response protein, which plays an important role in cell division, DNA repair and apoptosis. This protein helps in proliferation in the actively DNA dividing normal cells and in cancer cells. The functions of ATR in a proliferating cell are well studied and known to involve regulation of replication fork and cell cycle progression after DNA damage. Whereas, in a non-replicating cell, the functions of ATR are not so well known. In the human body, most of the …

Xeroderma Pigmentosum A Deficiency Results In Increased Generation Of Microvesicle Particles In Response To Ultraviolet B Radiation, Christian Lea Rajeshkumar

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Xeroderma Pigmentosum is a genetic disorder in which ability to repair DNA damage such as from UV radiation is decreased. Nucleotide excision repair is known for repairing DNA damage caused by UV radiation and XPA plays a major role in recognizing and eliminating abnormal section of DNA. Therefore, XPA deficiency decreases repair efficiency of DNA. Of note, XPA deficiency is linked with photosensitivity. Microvesicle particles are membrane-bound particles which are released into the extracellular environment in response to multiple stimuli including the lipid Platelet activating factor (PAF). Previous studies have shown that XPA deficiency can induce increase production of reactive …

Insulin-Like Growth Factor-1 (Igf-1) Impacts P53-Regulated Gene Products In Uvb-Irradiated Human Keratinocytes And Skin Epidermis, Abdulrhaman Mohammed Mohammed Alkawwar

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Skin cancer is the most prevalent human malignancy and is primarily caused by ultraviolet (UV) wavelengths of sunlight. However, the fact that most skin cancers occur in people over the age of 60 indicates that advantaged age is a second skin cancer risk factor. Why geriatric skin is prone to developing skin cancers is not clear, but several studies have shown that dermal fibroblasts in geriatric skin express lower levels of the hormone insulin-like growth factor-1 (IGF-1) than young adult skin and that deficient IGF-1 signaling negatively impacts how epidermal keratinocytes respond to UVB radiation. A major regulator of the …

Identification Of New Metabolic Mutations In The Fission Yeast Schizosaccharomyces Pombe That Sensitize The Cell To Hydroxyurea, Alaa Mahdi

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Cancer is a life-threatening illness and innovative research is therefore required to fuel the development of new anti-cancer therapies. As an anti-proliferative drug, hydroxyurea (HU) has been used in the treatment of various neoplastic and non-neoplastic diseases such as sickle cell anemia, psoriasis, and viral infections. HU is a well-known inhibitor of ribonucleotide reductase (RNR), an enzyme that generates dNTPs for DNA replication and repair. In our genetic screen in fission yeast looking for mutants with defects in checkpoint response, we also found a set of mutants that are highly sensitive to HU but with a functional checkpoint response. It …

Multiple Genotoxic Agents Activate Atr Kinase Signaling In Quiescent Human Cells, Mariyyah Ahmed O. Madkhali

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The ATR protein kinase is activated in response to DNA damage and other forms of genotoxic stress caused by both environmental carcinogens and anti-cancer drugs. However, much of our understanding of ATR kinase function is limited to proliferating cells in which DNA replication stress is the primary signal for ATR activation and where the major regulatory targets of ATR signaling are proteins involved in DNA synthesis and cell cycle progression. Here we have used HaCaT keratinocytes maintained in a non-replicating, quiescent state in vitro to examine how cell killing by different genotoxic agents is impacted by cell growth status and …

Role Of Exercise In Macrophage Polarization Of Perivascular Adipose Tissue And Adipose Tissue Inflammation In Hypertensive Mice Model, Venkata Sai Usha Sri Polaki

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Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. It can lead to severe health complications and increase the risk of heart disease, stroke, and sometimes death. Perivascular adipose tissue (PVAT) is known as the adipose tissue (AT) surrounding all the blood vessels and plays a critical role in the pathogenesis of the vascular disease. In vascular pathologies, PVAT increases in volume and becomes dysfunctional, with altered cellular composition and molecular characteristics. Macrophages have been found to accumulate in PVAT during hypertension, which might be involved …

Potential Role Of Ahr In Antibody Production, Mili Bhakta

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Aryl hydrocarbon receptor (AhR) mediates the immunosuppressive effects of 2,3,7,8 -tetrachlorodibenzodioxin (TCDD) in murine B cells. The effects of AhR activation on the regulation of expression of human immunoglobulin isotypes (μ, γ1-4, α1-2 and ε) and Ig secretion is unclear. Our previous results using CL-01 cell-line originating from a Burkitt’s lymphoma patient, demonstrated an inhibitory effect of TCDD on IgG expression but a surprising and marked loss of IgG secretion when the AhR was knocked out by siRNA or CRISPR/Cas9 gene editing. To determine if the AhR is a critical mediator of IgG expression, current study is focused on characterizing …

Differing Functions Of Atr Kinase In Human Epidermal Keratinocytes Exposed To Ultraviolet B Radiation, Kavya Shaj

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Ataxia-telangiectasia and Rad-3 related (ATR) is a DNA damage response protein kinase that is upregulated in various cancer cell types and has key roles in cell cycle progression, DNA repair and apoptosis. Small molecule ATR kinase inhibitors are of importance as antineoplastic agents because they sensitize cancer cells to DNA damaging chemotherapy drugs. However, only a few studies have looked at the effects of ATR kinase inhibitors on non-replicating cells, which constitute the majority of cells in the human body and have suggested an opposite, pro-apoptotic role for ATR kinase signaling in non-replicating cells in comparison to a pro-survival function …

Species Differences In The Effects Of Tcdd On A Transcriptional Regulatory Region Within The Ig Heavy Chain Gene, Zahra J. Alfaheeda

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The immunoglobulin heavy chain gene (Igh) is regulated by numerous regulatory elements including the 3'Igh regulatory region (3'IghRR). Several transcription factors are involved in modulating the 3'IghRR including NF-B, AP-1, and the aryl hydrocarbon receptor (AhR). The AhR is a ligand-activated transcription factor that mediates the transcription of genes involved in the metabolism of environmental toxicants such as TCDD. TCDD binds AhR and regulates immunoglobulin (Ig) expression in B cells of animal models. This modulation appears to be directly mediated by binding of the AhR to dioxin response elements (DRE) within the 3'IghRR. Structural differences have been found between the …

Behavior Of Gold Nanoparticles In Physiological Environment And The Role Of Agglomeration And Fractal Dimension, Rose Cooper

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The Present study was designed to examine the role of agglomeration, density and the resulting fractal dimension of nanomaterials in cell culture media. Studies were completed on the kinetics and the process of agglomeration, as well as how to calculate fractal dimensions. The correlation of such complex agglomeration patterns of nanomaterials in culture media, their translocation into cells, and toxic effects were observed. Our results showed that smaller primary particles agglomerated at an accelerated rate when compared to the larger primary particles. They also demonstrated increased cellular uptake, but exhibited lower fractal dimensions. The larger primary particle agglomerates displayed obvious …

Enhanced Angiotensin Ii-Induced Cardiac And Aortic Remodeling In Ace2 Knockout Mice, Mahmoud Alghamri

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Activation of the renin angiotensin system (RAS) is a well-known driving force, governing the aggravation and progression of CVD and associated target organ damage. Angiotensin (Ang) converting enzyme 2 (ACE2), a new member within the RAS family, was first cloned from the ventricle of patient with heart failure. ACE2 was shown to be upregulated under pathological conditions. We hypothesize that loss of ACE2 negatively affects cardiac function and exacerbates hypertrophic cardiomyopathy and aortic remodeling in response to Ang II. Eight weeks old ACE2 knock out (KO) and wild type (WT) mice were infused with Ang II s.c. (1000 ng/kg/min for …

Response Of Monovalent Cation Transporters To Pro-Apoptotic Protein Kinase C Modulators In Human Lens Epithelial Cells, Michael Anthony Lepera

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Protein kinase inhibition by staurosporine causes apoptotic volume decrease involving potassium (K) channels in immortalized human B3 lens epithelial cells (LECs). Here, the effect of two pro-apoptotic protein kinase C (PKC) inhibitors [12-O-tetradecanoyl-phorbol-13-acetate (TPA) and chelerythrine (CET)] were studied on membrane K transport in a fetal human LEC line (FHL124) by western blotting, immunofluorescence, ion flux, ATP, apoptosis, and biotinylation assays. Long term TPA exposure (0-6 h) inhibited 75% of Na-K-2Cl cotransport (NKCC). In contrast, short term (0-20 min) exposure to 50 μM CET reduced Na/K pump and NKCC by >90% and >70%, respectively, without retrieval from the membrane into …

Differentiation Of Megakaryocytes/Platelets And Neurons From Human Endometrial Stromal Progenitor Cells, Jinju Wang

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Human endometrium is a high dynamic tissue that contains stem/progenitor cells. These endometrial stromal progenitor cells (hESCs) have been differentiated into a number of mesodermal lineages. There is limited information on differentiating hESCs into neurons, and no information on differentiating hESCs into megakaryocytes (MKs) and platelets (PLTs). The aim of this work was to investigate the possibility of differentiating hESCs into two distinct lineages: MKs, with subsequent PLT formation, and neurons.

We isolated hESCs from human endometrial tissue and cultured the cells for 4-6 passages. Before each differentiation experiment, the purity of hESCs was confirmed by flow cytometry analysis which …