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Full-Text Articles in Life Sciences

Genomic Instability At A Polypurine/Polypyrimidine Repeat Sequence, Nathen S. Zavada Jan 2022

Genomic Instability At A Polypurine/Polypyrimidine Repeat Sequence, Nathen S. Zavada

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Microsatellite repeat sequences have been shown to induce replication stalling, fork collapse, double-strand breaks (DSBs), and possibly stimulate break-induced replication. In this study we use a dual-fluorescent HeLa model that is designed to monitor recombination at an ectopic site through use of flow cytometry and inverse PCR with a microsatellite in the lagging strand for DNA synthesis. To test the stability of the 78 bp polypurine/pyrimidine repeat from the PDK1 locus, we subjected cells to replication stress drugs designed to induce DSBs and measure break-induced replication (BIR). The study revealed that polypurine repeat cells undergo endogenous stress contributing to instability …


Microsatellites And Their Association With Break Induced Replication, French J. Damewood Iv Jan 2021

Microsatellites And Their Association With Break Induced Replication, French J. Damewood Iv

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To study microsatellites instability and their repair pathways a dual fluorescent (DF2) and selectable (ganciclovir sensitive/ thymidine kinase (TK) expressing) cell system was assayed using replication fork stalling agents hydroxyurea and telomestatin. These cell lines carried ectopically integrated microsatellites derived from the Dystrophia Myotonica Protein Kinase (DMPK) gene ((CTG)102 microsatellite), or an 88 bp polypurine/ polypyrimidine (Pu/Py) repeat from the PKD-1 locus, inserted into a FLP recombinase target site. These microsatellites form non-B DNA structures in -vivo and in-vitro causing replication fork stalling and double strand breaks. DF2 myc (CTG)102 -TK cells treated with hydroxyurea were assayed for mutagenesis of …


The Protective Effects Of Mir-210 Modified Endothelial Progenitor Cells Released Exosomes In Hypoxia/Reoxygenation Injured Neurons, Sri Meghana Yerrapragada Jan 2021

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 Jan 2021

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 …


Microsatellites And Their Association With Break Induced Replication, French J. Damewood Iv Jan 2021

Microsatellites And Their Association With Break Induced Replication, French J. Damewood Iv

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To study microsatellites instability and their repair pathways a dual fluorescent (DF2) and selectable (ganciclovir sensitive/ thymidine kinase (TK) expressing) cell system was assayed using replication fork stalling agents hydroxyurea and telomestatin. These cell lines carried ectopically integrated microsatellites derived from the Dystrophia Myotonica Protein Kinase (DMPK) gene ((CTG)102 microsatellite), or an 88 bp polypurine/ polypyrimidine (Pu/Py) repeat from the PKD-1 locus, inserted into a FLP recombinase target site. These microsatellites form non-B DNA structures in -vivo and in-vitro causing replication fork stalling and double strand breaks. DF2 myc (CTG)102 -TK cells treated with hydroxyurea were assayed for mutagenesis of …


Topical Photodynamic Therapy Generates Microvesicle Particles, Oladayo Ayobami Oyebanji Jan 2020

Topical Photodynamic Therapy Generates Microvesicle Particles, Oladayo Ayobami Oyebanji

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Photodynamic therapy (PDT) involves the use of light at an appropriate wavelength acting on a photosensitizing chemical to cause cell death via generation of reactive oxygen species. PDT has been useful in the management of skin conditions (like acne, psoriasis) and cancers like superficial skin, esophageal and non-small cell lung cancers. In addition to these therapeutic effects, previous murine studies from our group have demonstrated that topical PDT induces immunosuppression in vivo. Thus, topical PDT of skin can generate systemic effects through unknown mechanisms. Our group showed that PDT induces an immunosuppressive effect which occurs partly via Platelet-Activating Factor Receptor …


Assessment Of In Vivo Muscle Force In The R6/2 Mouse Model Of Huntington's Disease Using Newly Designed Force Rig, Steven Russell Alan Burke Jan 2020

Assessment Of In Vivo Muscle Force In The R6/2 Mouse Model Of Huntington's Disease Using Newly Designed Force Rig, Steven Russell Alan Burke

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In this thesis, we develop a system to study in vivo muscle function in a mouse model of Huntington’s disease that allows for the recording of muscle force by stimulating the motor nerves or the muscles directly after a nerve block. This allows us to distinguish between defects in the nerve, such as problems with vesicle release, and primary muscle defects, such as altered intracellular calcium homeostasis. We hypothesize that there are primary defects in R6/2 skeletal muscle that are separate from neurodegeneration or defects in the CNS. In this case, we should see defects in muscle force generation during …


Erk3 Negatively Regulates The Il-6/Stat3 Signaling Via Socs3, Astha Shakya Jan 2019

Erk3 Negatively Regulates The Il-6/Stat3 Signaling Via Socs3, Astha Shakya

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Mitogen activated protein kinases (MAPKs) are Ser/Thr kinases that relay the extracellular signal into intracellular responses and regulate several biological responses. They are classified into conventional MAPKs and atypical MAPKs. Extracellular signal regulated kinase 3 (ERK3) is an atypical MAPK that has a single phospho-acceptor site (Ser 189) in its activation motif instead of the canonical Thr-Xaa-Tyr (TXY) motif of conventional MAPK like ERK1/2. ERK3 comprises of a unique C terminal tail and a central C34 domain that further distinguishes it from ERK1/2. Moreover, compared to ERK1/2, much less is known about the upstream activators and the downstream targets of …


∆Np63Α Positively Regulates Erk3 Expression In Non-Melanoma Skin Cancer, Eid Salem Alshammari Jan 2019

∆Np63Α Positively Regulates Erk3 Expression In Non-Melanoma Skin Cancer, Eid Salem Alshammari

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Non-melanoma skin cancer (NMSC) is a group of skin cancer that includes basal cell carcinoma of the skin (BCC), squamous cell carcinoma of the skin (SCC), actinic keratoses, a precursor to SCC, and other rare cutaneous carcinomas. p63, a member of the p53 gene family, is an important regulator for epithelial tissue growth and development. ∆Np63α, a main isoform of p63, is highly expressed in NMSC and plays essential roles in NMSCs development. Extracellular signal-regulated kinase 3 (ERK3) is an atypical member of the MAPK family. It possesses a single phosphorylation site (serine 189) in its activation loop, which makes …


Lipin1 Regulates Skeletal Muscle Differentiation Through The Pkc/Hdac5/Mef2c:Myod -Mediated Pathway, Abdulrahman M. Jama Jan 2018

Lipin1 Regulates Skeletal Muscle Differentiation Through The Pkc/Hdac5/Mef2c:Myod -Mediated Pathway, Abdulrahman M. Jama

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Our previous characterization of global lipin1-deficient (fld) mice demonstrated that lipin1 played a novel role in skeletal muscle (SM) regeneration. The clinical relevance of lipin1 has been observed in patients with lipin1 null mutations where they exhibited severe rhabdomyolysis with aggregated and dysfunctional mitochondria. Lipin1 is a key gene that plays an important role in lipid biosynthesis and metabolism. It has dual functions as it contains a phosphatase activity that converts phosphatidic acid (PA) to diacylglycerol (DAG), the penultimate step in triglycerides (TAG) biosynthesis as well as transcriptional co-activator function. In the cytosol and ER, lipin1 carries out its lipid …


Novel Approaches For The Eradication Of Hiv Latently Infected Cells, Sally Al Ali Jan 2013

Novel Approaches For The Eradication Of Hiv Latently Infected Cells, Sally Al Ali

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The development of a suitable experimental cell model to study HIV latency in primary cells could have a massive effect on the current approaches to eradicate virus in latently infected cells. The main proposal of this paper is to develop an in vitro HIV cell model that represents HIV latency in vivo, then to create a more effective viral vector in order to target HIV reservoirs. For this goal, a directed evolution method is suggested to be used in order to mutate the AAV cap gene to generate a recombinant AAV vector that is capable of infecting primary resting CD4+ …