Pharmacology, Toxicology and Environmental Health Commons^™

Identification And Quantification Of The Collagen Type I, Iii And V In Rabbit Patellar Tendons, Mahesh Chandra Kodali

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Tendon injuries pose a great clinical challenge to orthopedic surgeons. Over 200,000 patients undergo tendon repair every year in the United States alone. The role of progression of a tendon injury is multifactorial as a lot of factors come into play during and after the injury at various phases of healing process. There is a still a vast requirement for thorough elucidation and understanding of the pathophysiology and the factors involved in the progression of tendon injury. Although the degenerative role of several MMPs and ADAMTs have been reported, yet there is very less information on the actual role and …

Interaction Between Na/ K-Atpase And Bcl-2 Proteins Bclxl And Bak, Tariq M. Alqahtani

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In silico analysis predicts interaction between the Na/ K-ATPase (NKA) and Bcl-2 protein canonical motifs BH3 and BH1. Such interaction is consistent with NKA inhibition by the benzo-phenanthridine alkaloid chelerythrine (CHE), a BH3 mimetic, in human lens epithelial cells (HLEC). This report establishes proof of concept: co-immuno-precipitation and immuno-colocalization showed unequivocal and direct interaction between NKA and Bcl-2 proteins. Particularly, NKA-antibodies co-immunoprecipitated BclXl and BAK in three different epithelial cell lines, HLECs and A549 lung cancer cells, whereas anti-Bcl-2 antibodies failed to pull down NKA. The molecular mass of the BAK proteins pulled down by antibodies against NKA and BclXl …

Endothelial Cell Derived Mvs And Exosomes: Release And Functional Study, Langni Liu

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Extracellular vesicles are membrane derived vesicles exists in all organs. The two major functioning extracellular vesicles are exosomes (EXMs) and microvesicles (MVs). EXMs released from cell membranes via exocytosis with size between 30-150 nm in diameter and MVs directly budded from plasma membrane and size between 100-1000 nm. Ceramide is one of the most important factor in lipid mechanism for EXM release and also associated with MV release. Ceramide generated from breakdown of sphingomyelin by neutral sphingomyelinase (nSMase). In this study, we used an nSMase inhibitor (GW4869) and an analogue of ceramide (C6-ceramide) to modulate the release of MVs and …

Differential Effects Of The Ahr On Immunoglobulin Gene Expression In Human B Cells, Naga Lakshmi Kaulini Burra

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2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a potent and persistent environmental toxin known to inhibit immunoglobulin (Ig) gene expression in various animal models. TCDD is thought to modulate gene expression through the aryl hydrocarbon receptor (AhR) and thereby a subsequent alteration in gene expression. The AhR is a ligand-activated transcription factor that regulates xenobiotic-metabolizing enzymes. The mouse 3'Ig heavy chain regulatory region (3'IghRR) is a sensitive transcriptional target of TCDD that may mediate, in an AhR-dependent manner, the inhibitory effect of TCDD on Ig expression. Human B cells could also be a sensitive target of TCDD. The current study focuses on determining the …

Role Of Bumetanide On Insulin Secretion, Mohammed Mashari Almutairi

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Insulin secretion depends on the electrical properties of the ß-cells in pancreatic islets. The consensus mechanism of insulin secretion involves glucose-stimulated metabolic increase in the ATP/ADP ratio. This increase closes ATP-sensitive K+ (KATP) channels resulting in ß-cell plasma membrane depolarization, which in turn activates voltage-dependent Ca2+ channels further resulting in Ca2+ influx and release of insulin stored in granules. In addition to this well-known consensus mechanism, insulin secretion also depends on electrogenic efflux of Cl- ions. The Na+K 2Cl- cotransporters (NKCCs) maintain the intracellular concentration of Cl- ([Cl-]i) at values higher than those predicted at thermodynamic equilibrium. This distribution of …

Characterization Of Small Conductance Calcium-Activated Potassium Channels In A Human Lens Epithelium Cell Line (B3), Wedad Ali Saqar

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Small conductance calcium-activated potassium (SK) channels belong to the family of K+ channels. They play a significant role in cell volume regulation and in lens homeostasis, and thus are associated with cataract formation. This study was designed to demonstrate the presence of the four different isoforms of SK channels (SK1, SK2, SK3, and SK4) in human lens epithelial (HLE)-B3 cell line using Western blot (WB), immunofluorescence (IF), and reverse transcriptase coupled to the polymerase chain reaction (RT-PCR). Cataract formation involves SK-mediated K+ loss and gain of Na+ ions by lens cells. Further, it has been shown in previous studies that …

Inactivation Of At1a Receptors Attenuate Lactate Accumulation And Improve Cardiac Performance And Acid-Base Homeostasis During Endurance Exercise, Ahmad Mohammed Alhajoj

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Angiotensin Type 1 (AT1) receptors are involved in cardiovascular pathology. Losartan, the AT1 receptor blocker, in combination with exercise has been shown to be effective in improving cardiac performance. The goal of the study was to investigate the role of AT1a receptors on cardiac function, and exercise tolerance in response to aerobic exercise using AT1a receptor knockout (AT1aKO) mice. An exercise wheel system was used for the exercise paradigm. Male (C57BL/6) wild type (WT) and AT1aKO mice were randomly assigned to four groups: WT control (n=6), WT exercise (WTEX, n=8), AT1a KO (KO) control (n=5), and AT1a KO exercise (KOEX, …

Early Increase Of Cd11c In Human Monocyte-Derived Dendritic Cells In The Presence Of A/California/07/2009 (H1n1pdm), Amber M. Braddock

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Influenza A continues to cause significant morbidity and mortality. Vaccine production time, viral antigenic variability and low vaccine efficacy contribute to the annual pandemics and seasonal epidemics. A better understanding of human immune responses to influenza A could result in more effective vaccines. Dendritic cells (DCs) play an important role in the initiation of immune responses. Populations of B lymphocytes secrete protective antibodies but the role of different populations of B cells in the protective response is unknown. In this thesis we developed assays to determine subclasses of influenza specific antibodies. Mononuclear cells were assessed using flow cytometry to identify …

The Modulatory Role Of Circulating Microvesicles In Endothelial Progenitor Cell Function Is Altered In T2dm, Hala Mustafa Ammar

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Circulating microvesicles (cMVs) are the extracellular MVs released from the cells in the blood and on the vascular wall. Our previous study demonstrates that cMVs of diabetic mouse are detrimental to endothelial progenitor cells (EPCs), which are known to be very important for maintaining normal endothelial function and structure. In this study, we compared the levels of circulating EPCs and EPC-derived MVs (EPC-MVs) in diabetic and healthy subjects. Also, the migration ability, apoptosis rate and reactive oxygen species (ROS) production of EPCs cultured from diabetic and healthy subjects were determined. More importantly, we evaluated whether cMVs from healthy subjects (ch-MVs) …

Expression, Characterization, Cloning And Functional Impact Of Slc12a5 In The Endocrine Pancreas, Shams Kursan

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The Slc12a5 gene encodes the neuron-specific electroneutral K+Cl- cotransporter-2 (KCC2), a constitutively active Cl- extruder. In mature neurons, KCC2 functionally predominates over other members of the Slc12a family, particularly the Na+K+2Cl- cotransporter-1 (NKCC1), a ubiquitous Cl- loader. Therefore, KCC2 keeps and maintains the intracellular chloride concentration ([Cl-]i) below values predicted by thermodynamic equilibrium and in doing so, KCC2 plays a key role in neuron physiology: it makes possible the inhibitory action of neurotransmitters such as gamma-aminobutyric acid (GABA) and glycine. Neurons and insulin-secreting pancreatic ß-cells share many genes and functions. Indeed, neuron-specific genes have been also found in ß-cells whereas …

Effect Of The Broad-Spectrum Caspase Inhibitor Q-Vd-Oph On Neurodegeneration And Neuroinflammation Of Sarin Exposed Mice, Ekta J. Shah

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Organophosphates (OP) cause CNS hyperstimulation resulting in seizures, convulsions and brain damage. Sarin is a toxic nerve agent used in Syria, the Gulf War and in terrorist attacks in Japan. Exposure to sarin is associated with presence of dead neurons, activation of astrocytes, microglia and neuroinflammation. Since, cell death and neuroinflammation are found in sarin exposed animals, we evaluated the efficacy of Q-VD-OPh, a broad spectrum caspase inhibitor that prevents cell death and has anti-inflammatory properties. Currently, treatment for sarin exposures is effective only if administered within 30-40 minutes of exposure. In this study, adult female C57BL/6 mice were subjected …

Increased Urinary Angiotensin Converting Enzyme 2 (Ace2) And Neprilysin (Nep) In Type 2 Diabetic Patients, Sridevi Gutta

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Chronic Kidney Disease (CKD) has reached epidemic proportions affecting more than 20 million adults in the US. CKD is routinely diagnosed and defined as reduced glomerular filtration rate (GFR), increased urinary albumin creatinine ratio (UACR) or both. Diabetes, hypertension and obesity share a major part in causing CKD. Angiotensin (1-7) (Ang (1-7)) is a vasodilator that plays an important renoprotective role in the renin angiotensin system, counteracting the vasoconstrictor and proliferative effects of Ang II. ACE2 and NEP which form Ang (1-7) by degrading Ang II and Ang I, respectively. A Disintegrin and Metalloproteinase (ADAM) 17, which is responsible for …

Insulin Treatment Attenuates Renal Adam17 And Ace2 Shedding In Akita Diabetic Mice, Esam Said Busah Salem

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Diabetic patients have a 40%-50% lifetime chance of developing chronic kidney disease, which remains one of the leading causes of morbidity and mortality. Alterations within renin angiotensin system balance contribute to the pathogenesis of diabetic kidney disease. Angiotensin converting enzyme 2 (ACE2) has an endogenous renoprotective role due to its ability to form angiotensin (1-7) (Ang 1-7) by degrading angiotensin II (Ang II). We have shown previously that hyperglycemia increases urinary ACE2 and albumin excretion in db/db diabetic mice. The protease, disintegrin and metalloprotease (ADAM) 17, is involved in the shedding of several transmembrane proteins, including ACE2 in vitro. Tissue …

Physical Exercise Training But Not Metformin Attenuates Albuminuria And Shedding Of Ace2 In Type 2 Diabetic Db/Db Mice, Hari Krishna Somineni

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Angiotensin II (Ang II), a potent vasoconstrictor cleaved from Ang I, is responsible for renal damage in diabetes. Angiotensin converting enzyme 2 (ACE2) is highly expressed in the kidney and has been shown to be renoprotective by degrading Ang II to Ang-(1-7). A Disintegrin and Metalloproteinases (ADAMs) were recently identified as an ectodomain sheddases of transmembrane proteins. ADAM17 mediated shedding of renal ACE2 could contribute to the pathogenesis of diabetic nephropathy. In our previous study, rosiglitazone treatment normalized hyperglycemia and improved renal injury by preventing ACE2 shedding. The aim of this study is to test the hypothesis that improved glucose …

Bioaccumulation And Neuroinflammation Of Gold Nanoparticles In The Central Nervous System, Fahimeh Fallahi

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Gold nanoparticles (GNPs) possess unique physicochemical properties that may facilitate entry into the central nervous system (CNS) where they may act therapeutically. There is little information on biodistribution or inflammatory effects of GNPs in specific brain regions. Brain Localization and neuroinflammatory response to citrate-capped spherical GNP (10 nm) was determined 24 hours after intravenous (IV) injection in male C57Bl mice. A known inflammogen, lipopolysaccharide (LPS, 2 mg kg-1, SC), was tested as a positive control supplement. Aggregation of GNPs was measured using various Phosphate-Buffered Saline (PBS) concentrations (10, 1, 0.1, 0.01 X) to determine the optimal buffer concentration to maintain …

K-Cl Cotransport: Role Of Kcc3 In Cellular Potassium (K) Homeostasis In Kcc3- Transfected Hek-293 Cells, Nagendra Babu Ravilla

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K-Cl cotransport (KCC) mediated by four protein isoforms, KCC1 to KCC4, plays a significant role in cell volume regulation, and in K and Cl homeostasis. In this study, we demonstrate the importance of KCC3 and its two threonine (T) phosphorylation sites T991 and T1048 in cellular K homeostasis in isogenic human embryonic kidney (HEK-293) cells transfected with KCC3 wild type (WT) or constitutively active double mutant KCC3 (AA) expressed under tetracycline or doxycycline control. In both WT and AA cells, under baseline conditions, the Na-K-2Cl cotransport (NKCC) (55 %- 60 %) was the major contributor of Rb influx followed by …

Chronic Swim Stress Attenuates Endocrine Response And Improves Cardiac Function In Mice Lacking The Angiotensin Ii Type 1a Receptor, Najat Khalifa Almahroug

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Stress is a stimulus that causes an often abrupt but always large change in autonomic activity and hormone secretion. Angiotensin II (AngII) is one of the main neurohormonal mediators that are stimulated by stress. AngII mediates most of its relevant biological effects via AngII type1 receptor (AT1R) activation. Stress increases tissue and circulating levels of Ang II which contributes to stimulation of adrenal AT1R, mediating stressinduced hormone release. Ang II through the activation of AT1R not only elevates blood pressure but also has a patho-physiological relevance in cardiac remodeling. The goal of this study was to assess the influence of …

"Characterization Of Red Diamondback Rattlesnake Venom Proteins On Cell Death And Function", Venus Ebrahimian

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Snake venom is composed of many different toxins and protein components such as metalloproteases and phospholipase A2. Together, these proteins cause an up regulation in cell death pathways and disrupt the overall homeostasis of a living cell. The Red Diamondback Rattlesnake is abundantly available and well-known specie and has been used as a source for development of new drugs. It has been mainly used for the purposes of making anti-venom but it has also been therapeutically used for surgical purposes to act as an anti-aggregate. Integrins derived from RDB venom has been used for cancer cell treatment as well. Specifically …

Locating Chelerythrine, An Alkaloid, Within A Cytosolic Environment By Maldi-Tof Mass Spectrometry, Bradley Allen Williams

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The quaternary benzo-phenanthridine alkaloid (QBA) chelerythrine (CET) is a well-known inhibitor of PKC and cancer growth (Herbert et al., 1990). In human lens epithelial cells (HLECs), CET almost completely inhibits the Na+/K+ pump ATPase (NKA) without changes in phosphorylation (Lauf et al. 2013). Protein alignment studies revealed B-lymphocyte type 2 protein (Bcl-2) BH1- like motifs within the a1 subunit of the NKA to which CET, a drug mimicking Bcl-2 protein BH3-like motifs, might bind thus disrupting NKA function (Lauf et al, 2013). It is unknown by which mechanism CET crosses the plasma membrane to reach its intracellular targets, especially the …

Effects Of Red Diamondback Rattlesnake Venom On Keloid Dermal Fibroblasts In Vitro, Mackenzie Shelby Newman

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Keloid scarring is an inflammatory healing response to physical injury such as incision or piercing in the dermis. It is characterized by aberrant extracellular matrix production, the overaccumulation of mature collagen, and excessive fibroblast proliferation and migration beyond the borders of the original wound site. This results in swelling, depigmentation, itchiness, and pain akin to a benign tumor. Although there are myriad treatments for the condition, most are invasive and exhibit a high recurrence rate. Previous studies have shown that rattlesnake venom stimulates apoptosis in the skin via multiple specific mechanisms, largely composed of extracellular matrix and its receptors' interactions. …

Effects Of Ang 1-7 And Endothelial Microvesicles On Ang Ii-Induced Dysfunction And Apoptosis In Cerebral Endothelial Cells, Xiang Xiao

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Angiotensin II (Ang II) induces endothelial dysfunction and is implicated in the pathogenesis of vascular diseases. Angiotensin 1-7 (Ang 1-7) has been reported to counteract many deleterious effects of Ang II. Endothelial microvesicles (EMVs) are small membrane vesicles released from endothelial cells (ECs) undergoing stress and apoptosis. But their functions are largely unknown. In this study, we investigated the effects of Ang 1-7 and EMVs on apoptosis and dysfunction of human brain microvascular endothelial cells (HbmECs). Reactive oxygen species (ROS) and nitric oxide (NO) production, and Nox2, p-Akt/Akt, p-eNOS/eNOS expression were analyzed. We found that Ang II dose-dependently induced HbmEC …

Role Of Bax, Ibpa, Ibpb And Csph Genes In Protecting Cft073 (Uropathogenic Escherichia Coli) Against Salt And Urea Stress, Pavani Beesetty

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Uropathogenic Escherichia coli (UPEC) are the primary cause of 80 to 90% of uncomplicated urinary tract infections. After entering the urinary tract, uropathogenic E.coli has to tolerate high levels of salt and urea in urine to cause a successful infection. The osmotic stress imposed by urea is different from that by NaCl, as urea can freely move across the cell membrane and is a protein denaturant. Hence, microarray experiments were performed to observe the differential expression of genes in CFT073 (UPEC) due to the presence of 0.3 M NaCl and 0.6 M urea in K medium individually. Based on the …

Tolfenamic Acid Induces Cell Apoptosis And Inhibits Collagen Accumulation In Keloid Fibroblasts, Dan Yi

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Keloid scar is a fibroproliferative disorder which results from the accumulation of collagen through the activation of TGF-B/Smad signaling. Tolfenamic acid (TA) has been found to inhibit collagen synthesis in animal and induce cancer cell apoptosis. In this study, we investigated the effect of DMSO on cell apoptosis, TA on collagen deposition, and TA on collagen type I and smad2 protein expression in human normal fibroblasts (NFs) and human keloid fibroblasts (KFs). In the dose- and exposure time- response assays, we found that 1% DMSO for 48h treatment did not obviously induce NF and KF apoptosis and that 0.55x10-3 M …

The Aryl Hydrocarbon Receptor Regulates An Essential Transcriptional Element In The Immunoglobulin Heavy Chain Gene, Michael J. Wourms

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2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous environmental contaminant that inhibits immunoglobulin (Ig) expression and Ig heavy (IgH) chain gene transcription. Transcription of the IgH gene involves several regulatory elements including the 3'lgh regulatory region (3'lghRR) which is composed of four enhancers (hs3A, hs1,2, hs4, and hs3B). Dioxin responsive elements (DRE) in the hs4 and hs1,2 enhancers of the 3lghRR that bind the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that regulates dioxin sensitive genes suggest that the 3'lghRR may be a transcriptional target of TCDD. The current study utilized an IgA secreting mouse …

Role Of Na+K+2cl- Co-Transporters In Insulin Secretion, Saeed Alshahrani

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The objective of this study is to investigate the role of intracellular chloride concentration ([Cl^-]i) in insulin secretion in vivo and in vitro.

The maintenance of high [Cl^-]i in insulin-secreting pancreatic β-cells plays an important role in glucose-induced depolarization and insulin secretion. Insulinotropic glucose concentrations i.e., >6 mM induces electrical activity in β-cells which results in insulin secretion. This electrical activity is mainly due to electrogenic efflux of Cl^- from β-cells through volume-regulated anion channels (VRAC). The solute carrier family 12 group A member 1 (Slc12a1) and 2 (Slc12a2) encode several splice variants of the …

Elucidating Transcription Factor Regulation By Tcdd Within The Hs1,2 Enhancer, Sharon D. Ochs

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Immunoglobulin heavy chain (IgH) expression and Ig secretion is inhibited by the environmental contaminant 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD). Within the IgH gene, the 3' IgH regulatory region (3'IgH RR) has been identified as a transcriptional target of TCDD. The 3'IgH RR, which in part regulates transcription of the IgH gene, is composed of four enhancers in the mouse: hs3a; hs1,2; h3b; hs4 and three enhancers in the human: hs3a; hs1,2; hs4. In humans the hs1,2 enhancer has an invariant sequence (IS) containing a DRE, NF-κB, NF1 and AP-1 binding site. Also, the enhancer has an AP1.ETS and Oct …

Evaluation Of Cm-2,525 As A Neuroprotectant Against Sarin: A Comparison With 8-Oh-Dpat, Amanda R. Furman

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Exposure to the chemical warfare agent sarin produces long term neurological deficits. The long term medical consequences could be averted with the development of neuroprotectants to preserve brain function. In our mouse model, the combination of the carboxylesterase inhibitor 2-(o-cresyl)-4H-1:3:2-benzodioxaphosphorin-2-oxide (CBDP) with the organophosphorus (OP) nerve agent sarin was used to render mice more sensitive to poisoning and reduce the amount of hydrogen fluoride cleaved from sarin during binding to esterases. Since carboxylesterase acts as a scavenger, reducing the levels causes sarin to have a greater inhibition effect on acetylcholinesterase. These smaller doses permitted the use of doses similar to …

Use Of Phage Display Libraries To Select For B-Cell Receptor-Specific Peptides Of Chronic Lymphocytic Leukemia Cells, Richard M. Chou

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Peptides with high affinity to the B-cell receptor (BCR) fused to a toxin could be an effective therapy for Chronic Lymphocytic Leukemia (CLL) patients. We screened captured BCR of a CLL patient with peptides from 7 and 12-mer phage display libraries, using two strategies. Lymphocytes from two patients diagnosed with CLL expressing two different unmutated VH genes (VH 1-3 and VH4-34, respectively) were used. Membrane BCRs were obtained from patient CLL cells by lysis, identified by western blot, semi-quantified and screened with phage libraries. The first strategy involved using patient VH4-34 BCRs which were captured using goat anti-human IgM to …

Light-Limited Access To Fructose Alters Metabolic Function And Adipose Tissue Catecholaminergic Activity In Mice, Naima Salem Rodwan

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Consumption of high levels of fructose produces glucose intolerance, sympathetic nervous system activation, and renal dysfunction. A diet high in fructose may play a role in the worldwide epidemic of obesity and diabetes. The aim of this study was to test the hypothesis that time (light/dark) limited access to fructose influences body fat, metabolic function, and adipose tissue catecholaminergic activity in mice. Male C57BL/6 mice were given standard chow and assigned to one of three groups: Control (n=10, water 24h); FL (n=11, 10% fructose solution during 12h light period); and FD (n=10, 10% fructose solution during 12h dark period). Metabolic …

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 …