Genetic Phenomena Commons^™

Activating Connexin43 Gap Junctions Primes Adipose Tissue For Therapeutic Intervention, Yi Zhu, Na Li, Mingyang Huang, Xi Chen, Yu A An, Jianping Li, Shangang Zhao, Jan-Bernd Funcke, Jianhong Cao, Zhenyan He, Qingzhang Zhu, Zhuzhen Zhang, Zhao V Wang, Lin Xu, Kevin W Williams, Chien Li, Kevin Grove, Philipp E Scherer

Faculty, Staff and Students Publications

Adipose tissue is a promising target for treating obesity and metabolic diseases. However, pharmacological agents usually fail to effectively engage adipocytes due to their extraordinarily large size and insufficient vascularization, especially in obese subjects. We have previously shown that during cold exposure, connexin43 (Cx43) gap junctions are induced and activated to connect neighboring adipocytes to share limited sympathetic neuronal input amongst multiple cells. We reason the same mechanism may be leveraged to improve the efficacy of various pharmacological agents that target adipose tissue. Using an adipose tissue-specific Cx43 overexpression mouse model, we demonstrate effectiveness in connecting adipocytes to augment metabolic …

Tfeb Induces Mitochondrial Itaconate Synthesis To Suppress Bacterial Growth In Macrophages, Ev-Marie Schuster, Maximilian W Epple, Katharina M Glaser, Michael Mihlan, Kerstin Lucht, Julia A Zimmermann, Anna Bremser, Aikaterini Polyzou, Nadine Obier, Nina Cabezas-Wallscheid, Eirini Trompouki, Andrea Ballabio, Jörg Vogel, Joerg M Buescher, Alexander J Westermann, Angelika S Rambold

Duncan NRI Faculty and Staff Publications

Successful elimination of bacteria in phagocytes occurs in the phago-lysosomal system, but also depends on mitochondrial pathways. Yet, how these two organelle systems communicate is largely unknown. Here we identify the lysosomal biogenesis factor transcription factor EB (TFEB) as regulator for phago-lysosome-mitochondria crosstalk in macrophages. By combining cellular imaging and metabolic profiling, we find that TFEB activation, in response to bacterial stimuli, promotes the transcription of aconitate decarboxylase (Acod1, Irg1) and synthesis of its product itaconate, a mitochondrial metabolite with antimicrobial activity. Activation of the TFEB-Irg1-itaconate signalling axis reduces the survival of the intravacuolar pathogen Salmonella enterica serovar Typhimurium. TFEB-driven …

Vitamin C Reduces Igf-1 And Vegf Signaling In Retinal Endothelial Cells, Jonathon Reynolds

Annual Research Symposium

No abstract provided.

Identification Of The Global Mir-130a Targetome Reveals A Role For Tbl1xr1 In Hematopoietic Stem Cell Self-Renewal And T(8; 21) Aml, Gabriela Krivdova, Veronique Voisin, Erwin M Schoof, Sajid A Marhon, Alex Murison, Jessica L Mcleod, Martino M Gabra, Andy G X Zeng, Stefan Aigner, Brian A Yee, Alexander A Shishkin, Eric L Van Nostrand, Karin G Hermans, Aaron C Trotman-Grant, Nathan Mbong, James A Kennedy, Olga I Gan, Elvin Wagenblast, Daniel D De Carvalho, Leonardo Salmena, Mark D Minden, Gary D Bader, Gene W Yeo, John E Dick, Eric R Lechman

Faculty, Staff and Students Publications

Gene expression profiling and proteome analysis of normal and malignant hematopoietic stem cells (HSCs) point to shared core stemness properties. However, discordance between mRNA and protein signatures highlights an important role for post-transcriptional regulation by microRNAs (miRNAs) in governing this critical nexus. Here, we identify miR-130a as a regulator of HSC self-renewal and differentiation. Enforced expression of miR-130a impairs B lymphoid differentiation and expands long-term HSCs. Integration of protein mass spectrometry and chimeric AGO2 crosslinking and immunoprecipitation (CLIP) identifies TBL1XR1 as a primary miR-130a target, whose loss of function phenocopies miR-130a overexpression. Moreover, we report that miR-130a is highly expressed …

Ces2 Sustains Hnf4Α Expression To Promote Pancreatic Adenocarcinoma Progression Through An Epoxide Hydrolase-Dependent Regulatory Loop, Yihui Chen, Michela Capello, Mayrim V Rios Perez, Jody V Vykoukal, David Roife, Ya'an Kang, Laura R Prakash, Hiroyuki Katayama, Ehsan Irajizad, Alia Fleury, Sammy Ferri-Borgogno, Dodge L Baluya, Jennifer B Dennison, Kim-Anh Do, Oliver Fiehn, Anirban Maitra, Huamin Wang, Paul J Chiao, Matthew H G Katz, Jason B Fleming, Samir M Hanash, Johannes F Fahrmann

Faculty, Staff and Student Publications

Objective: Intra-tumoral expression of the serine hydrolase carboxylesterase 2 (CES2) contributes to the activation of the pro-drug irinotecan in pancreatic ductal adenocarcinoma (PDAC). Given other potential roles of CES2, we assessed its regulation, downstream effects, and contribution to tumor development in PDAC.

Methods: Association between the mRNA expression of CES2 in pancreatic tumors and overall survival was assessed using The Cancer Genome Atlas. Cell viability, clonogenic, and anchorage-independent growth assays as well as an orthotopic mouse model of PDAC were used to evaluate the biological relevance of CES2 in pancreatic cancer. CES2-driven metabolic changes were determined by untargeted and targeted …

A Novel Group Of Genes That Cause Endocrine Resistance In Breast Cancer Identified By Dynamic Gene Expression Analysis, Arvand Asghari, Katherine Wall, Michael Gill, Natascha Del Vecchio, Farnaz Allahbakhsh, Jacky Wu, Nan Deng, W Jim Zheng, Hulin Wu, Michihisa Umetani, Vahed Maroufy

Faculty, Staff and Student Publications

Breast cancer (BC) is the most common type of cancer diagnosed in women. Among female cancer deaths, BC is the second leading cause of death worldwide. For estrogen receptor-positive (ER-positive) breast cancers, endocrine therapy is an effective therapeutic approach. However, in many cases, an ER-positive tumor becomes unresponsive to endocrine therapy, and tumor regrowth occurs after treatment. While some genetic mutations contribute to resistance in some patients, the underlying causes of resistance to endocrine therapy are mostly undetermined. In this study, we utilized a recently developed statistical approach to investigate the dynamic behavior of gene expression during the development of …

An Asian Case Of Combined 17Α-Hydroxylase/17,20-Lyase Deficiency Due To Homozygous Pr96q Mutation: A Case Report And Review Of The Literature, Qian Liao, Rufei Shen, Mingyu Liao, Chenxi Ran, Ling Zhou, Yuling Zhang, Guiliang Peng, Zheng Sun, Hongting Zheng, Min Long

Center on Aging Staff Publications

Background: Combined 17α-hydroxylase/17,20-lyase deficiency (17-OHD) is a very rare form of congenital adrenal hyperplasia (CAH) caused by mutations in the CYP17A1 gene. Almost 100 different mutations of the CYP17A1 gene have been reported, including p.R96Q mutation, but no case of p.R96Q mutation has been described in Asian populations.

Case presentation: We describe a 22-year-old female patient of 46,XY karyotype, who presented with pseudohermaphrodism, primary amenorrhea, underdeveloped secondary sexual characteristics, delayed epiphyseal healing, hypertension, and hypokalemia. The diagnosis of 17-OHD was reached by measurement of steroid hormones and abdominal CT scan and confirmed by genetic sequencing, which revealed a homozygous p.R96Q …

Supercoiling And Looping Promote Dna Base Accessibility And Coordination Among Distant Sites, Jonathan M Fogg, Allison K Judge, Erik Stricker, Hilda L Chan, Lynn Zechiedrich

Faculty, Staff and Students Publications

DNA in cells is supercoiled and constrained into loops and this supercoiling and looping influence every aspect of DNA activity. We show here that negative supercoiling transmits mechanical stress along the DNA backbone to disrupt base pairing at specific distant sites. Cooperativity among distant sites localizes certain sequences to superhelical apices. Base pair disruption allows sharp bending at superhelical apices, which facilitates DNA writhing to relieve torsional strain. The coupling of these processes may help prevent extensive denaturation associated with genomic instability. Our results provide a model for how DNA can form short loops, which are required for many essential …

Targeting The Apoa1 Locus For Liver-Directed Gene Therapy, Marco De Giorgi, Ang Li, Ayrea Hurley, Mercedes Barzi, Alexandria M Doerfler, Nikitha A Cherayil, Harrison E Smith, Jonathan D Brown, Charles Y Lin, Karl-Dimiter Bissig, Gang Bao, William R Lagor

Faculty, Staff and Students Publications

Clinical application of somatic genome editing requires therapeutics that are generalizable to a broad range of patients. Targeted insertion of promoterless transgenes can ensure that edits are permanent and broadly applicable while minimizing risks of off-target integration. In the liver, the Albumin (Alb) locus is currently the only well-characterized site for promoterless transgene insertion. Here, we target the Apoa1 locus with adeno-associated viral (AAV) delivery of CRISPR-Cas9 and achieve rates of 6% to 16% of targeted hepatocytes, with no evidence of toxicity. We further show that the endogenous Apoa1 promoter can drive robust and sustained expression of therapeutic …

Effects Of Nicotinamide Riboside And Beta-Hydroxybutyrate On C. Elegans Lifespan, Jeffery Peters

Undergraduate Honors Theses

The nicotinamide riboside (NR) form of vitamin B₃and the ketone body ß-hydroxybutyrate (BHB) are two of the most promising natural compounds yet identified for the treatment of aging and aging-related diseases. Forms of vitamin B₃are precursors for the synthesis of the coenzymes nicotinamide adenine dinucleotide (NAD(H)) and nicotinamide adenine dinucleotide phosphate (NADP(H)). In aged cells levels of NAD⁺decline, decreasing metabolism and decreasing activity of protective sirtuin protein deacetylases. In aged cells NR, but not more common forms of vitamin B3, boost NAD⁺levels. BHB is naturally produced by the body when individuals fast …

An In-Depth Review Of Retinitis Pigmentosa Development And Pathologies Overtime In Patients, Abdul Harris

Honors College Theses

Retinitis Pigmentosa is a disease which can cause blindness and affects around 2.5 million people worldwide. It is a disorder that has a multitude of ways of being inherited, such as autosomal dominant, autosomal recessive as well as X-linked and mitochondrial linked disorder. While some versions of RP may be syndromic (20%-30%), a majority of cases are in fact non-syndromic. The majority of non-syndromic cases inherited via autosomal dominant RP having RHO gene mutations, and X-linked means of inheritance having majority of patients with RPGR gene mutations. Ushers Syndrome, a syndromic version of retinitis pigmentosa and autosomal recessive RP having …

The Pharmabiotic For Phenylketonuria: Development Of A Novel Therapeutic, Chloé Elizabeth Lebegue

Senior Theses

Phenylketonuria, now known as phenylalanine hydroxylase (PAH) deficiency, is a genetic disorder of metabolism affecting approximately one in every 15,000 infants born in the United States. Patients have nonfunctional PAH enzyme secondary to one or more genetic mutations. The enzyme deficit results in destructive supraphysiologic blood phenylalanine levels upon consumption of the essential dietary amino acid phenylalanine. Current standards of care mitigate signs and symptoms of the disorder, but do not approach a cure. The methods for creating a prototype pharmabiotic as an innovative treatment strategy for PAH deficiency are described herein.

DNA molecular cloning techniques were utilized to engineer …

Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle

Electronic Theses and Dissertations

Background: Human arylamine N-acetyltransferase 1 (NAT1) is a phase II xenobiotic metabolizing enzyme found in almost all tissues. NAT1 can additionally hydrolyze acetyl-coenzyme A (acetyl-CoA) in the absence of an arylamine substrate. NAT1 expression varies inter-individually and is elevated in several cancers including estrogen receptor positive (ER+) breast cancers. Additionally, multiple studies have shown the knockdown of NAT1, by both small molecule inhibition and siRNA methods, in breast cancer cells leads to decreased invasive ability and proliferation and decreased anchorage-independent colony formation. However, the exact mechanism by which NAT1 expression affects cancer risk and progression remains unclear. Additionally, consequences …

P33. Design And Evaluation Of An Escherichia Coli Biomarker For Indication Of Ph, Kevin X. Zhou, Luana Langlois, Ashmita Singh, John Prince

Western Research Forum

Measuring pH is one of the most commonly used techniques in both the laboratory as well as the field due to its importance in a multitude of biochemical processes. Traditional methods of measuring pH may be highly developed in accuracy and precision but often involve disruption of the environment. Biological markers offer an alternative that allows for long-term pH monitoring. This innovative approach allows for vast applications such as in the manufacturing, food processing and research industries. Under moderate acidic conditions, the asr (acid shock RNA) gene is highly inducible and has been demonstrated to be crucial for growth at …

Analysis Of The Role Of Astrocyte Elevated Gene-1 In Normal Liver Physiology And In The Onset And Progression Of Hepatocellular Carcinoma, Chadia L. Robertson

Theses and Dissertations

First identified over a decade ago, Astrocyte Elevated Gene-1 (AEG-1) has been studied extensively due to early reports of its overexpression in various cancer cell lines. Research groups all over the globe including our own have since identified AEG-1 overexpression in cancers of diverse lineages including cancers of the liver, colon, skin, prostate, breast, lung, esophagus, neurons and neuronal glia as compared to matched normal tissue. A comprehensive and convincing body of data currently points to AEG-1 as an essential component, critical to the progression and perhaps onset of cancer. AEG-1 is a potent activator of multiple pro-tumorigenic signal transduction …

A Truncation Mutation In Tbc1d4 In A Family With Acanthosis Nigricans And Postprandial Hyperinsulinemia, Satya Dash, Hiroyuki Sano, Justin J. Rochford, Robert K. Semple

Dartmouth Scholarship

Tre-2, BUB2, CDC16, 1 domain family member 4 (TBC1D4) (AS160) is a Rab-GTPase activating protein implicated in insulin-stimulated glucose transporter 4 (GLUT4) translocation in adipocytes and myotubes. To determine whether loss-of-function mutations in TBC1D4 might impair GLUT4 translocation and cause insulin resistance in humans, we screened the coding regions of this gene in 156 severely insulin-resistant patients. A female presenting at age 11 years with acanthosis nigricans and extreme postprandial hyperinsulinemia was heterozygous for a premature stop mutation (R363X) in TBC1D4. After demonstrating reduced expression of wild-type TBC1D4 protein and expression of the truncated protein in lymphocytes from the proband, …

Identification And Characterization Of Novel Sir3/Mecp2-Chromatin Interactions, Nicholas L. Adkins

Theses, Dissertations and Capstones

The eukaryotic genome is packaged into chromosomes that are made up of a highly organized and heavily regulated structure called chromatin. The proteins involved in the compaction of DNA into this condensed state are mostly understood at the level of the structure of the nucleosome. The higher order arrangement of chromatin and how it effects gene regulation is only partially understood and characterized. The compaction of nucleosomal arrays into 30-nm and higher structures are partially the responsibility of architectural, or structural, chromatin associated proteins. The following dissertation analyzes the individual chromatin contributions of two well studied architectural proteins, the yeast …

Glucocorticoid Regulation Of Insulin Like Growth Factor Binding Protein-5 Gene Transcription In Human Osteoblasts, Xiaoying Wang

Loma Linda University Electronic Theses, Dissertations & Projects

Glucocorticoids (GCs) inhibit bone formation in vivo and inhibit osteoblast proliferation and collagen synthesis in vitro. These effects may be mediated by alterations in the insulin-like growth factor (IGF) system. In the present study of normal human osteoblast-like (HOB) cells, we tested the hypothesis that dexamethasone (Dex) inhibits the expression of IGF binding protein-5 (IGFBP-5). Dex decreased IGFBP-5 mRNA levels to 54% of control after 4 hr. Dex did not modify the decay of IGFBP-5 mRNA in transcriptionally arrested osteoblast cells. Dex decreased IGFBP-5 hnRNA levels to 67% of control after 2 hr, and the activity of the human IGFBP- …

Molecular Mechanism Of The Stimulation Of Alkaline Phosphatase Activity In Human Bone Cells By 1,25(Oh)2 D3, Eru Kyeyune-Nyombi

Loma Linda University Electronic Theses, Dissertations & Projects

To facilitate this study an in vitro human model system was established that exhibited many aspects of normal osteoblasts. The human osteosarcoma cell line (TE85 cells) expressed a skeletal alkaline phosphatase activity (an accepted bone cell differentiation marker) which was stimulated by 1,25(OH)₂D₃ (a potent differentiating agent), under serum-free conditions in a dose-dependent, time-dependent, and cell density-dependent manner. Cytochemical analysis of the stimulation of ALP activity by 1,25(OH)₂D₃ showed that 1,25(OH)₂D₃ increased the number of TE85 cells that expressed detectable ALP activity, suggesting that 1,25(OH)₂D₃ promoted the process …