1
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Forte NR, Veasey VN, Christie BJ, Carter A, Hanks MA, Holderfield A, Houston T, Challa AK, Turner AN. Engaging students in a genetics course-based undergraduate research experience utilizing Caenorhabditis elegans in hybrid learning to explore human disease gene variants. J Microbiol Biol Educ 2023; 24:e00078-23. [PMID: 38108007 PMCID: PMC10720527 DOI: 10.1128/jmbe.00078-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 10/13/2023] [Indexed: 12/19/2023]
Abstract
Genetic analysis in model systems using bioinformatic approaches provides a rich context for a concrete and conceptual understanding of gene structure and function. With the intent to engage students in research and explore disease biology utilizing the nematode Caenorhabditis elegans model, we developed a semester-long course-based undergraduate research experience (CURE) in a hybrid (online/in-person) learning environment-the gene-editing and evolutionary nematode exploration CURE (GENE-CURE). Using a combination of bioinformatic and molecular genetic tools, students performed structure-function analysis of disease-associated variants of uncertain significance (VUS) in human orthologs. With the aid of a series of workshop-style research sessions, students worked in teams of two to six members to identify a conserved VUS locus across species and design and test a polymerase chain reaction-based assay for targeted editing of a gene in the nematode and downstream genotyping. Research session discussions, responsible conduct of research training, electronic laboratory notebook, project reports, quizzes, and group poster presentations at a research symposium were assessed for mastery of learning objectives and research progress. Self-reflections were collected from students to assess engagement, science identity, and science efficacy. Qualitative analysis of these reflections indicated several gains suggesting that all students found many aspects of the GENE-CURE rewarding (learning process of research, self-confidence in research and science identity, and personal interest) and challenging (iterative research and failure, time management, COVID-19 pandemic, and life issues).
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Affiliation(s)
- Natalie R. Forte
- Department of Biology, Jacksonville State University, Jacksonville, Alabama, USA
| | - Virginia N. Veasey
- Department of Biology, Jacksonville State University, Jacksonville, Alabama, USA
| | - Bethany J. Christie
- Department of Psychology, Jacksonville State University, Jacksonville, Alabama, USA
| | - Amira Carter
- Department of Biology, Jacksonville State University, Jacksonville, Alabama, USA
| | - Marli A. Hanks
- Department of Secondary Education, Jacksonville State University, Jacksonville, Alabama, USA
| | - Alan Holderfield
- Department of Secondary Education, Jacksonville State University, Jacksonville, Alabama, USA
| | - Taylor Houston
- Department of Secondary Education, Jacksonville State University, Jacksonville, Alabama, USA
| | - Anil K. Challa
- Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
- Department of Life Sciences, Shiv Nadar University, Delhi, National Capital Region, India
| | - Ashley N. Turner
- Department of Biology, Jacksonville State University, Jacksonville, Alabama, USA
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2
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Chen J, Baxi K, Lipsitt AE, Hensch NR, Wang L, Sreenivas P, Modi P, Zhao XR, Baudin A, Robledo DG, Bandyopadhyay A, Sugalski A, Challa AK, Kurmashev D, Gilbert AR, Tomlinson GE, Houghton P, Chen Y, Hayes MN, Chen EY, Libich DS, Ignatius MS. Defining function of wild-type and three patient-specific TP53 mutations in a zebrafish model of embryonal rhabdomyosarcoma. eLife 2023; 12:e68221. [PMID: 37266578 PMCID: PMC10322150 DOI: 10.7554/elife.68221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/01/2023] [Indexed: 06/03/2023] Open
Abstract
In embryonal rhabdomyosarcoma (ERMS) and generally in sarcomas, the role of wild-type and loss- or gain-of-function TP53 mutations remains largely undefined. Eliminating mutant or restoring wild-type p53 is challenging; nevertheless, understanding p53 variant effects on tumorigenesis remains central to realizing better treatment outcomes. In ERMS, >70% of patients retain wild-type TP53, yet mutations when present are associated with worse prognosis. Employing a kRASG12D-driven ERMS tumor model and tp53 null (tp53-/-) zebrafish, we define wild-type and patient-specific TP53 mutant effects on tumorigenesis. We demonstrate that tp53 is a major suppressor of tumorigenesis, where tp53 loss expands tumor initiation from <35% to >97% of animals. Characterizing three patient-specific alleles reveals that TP53C176F partially retains wild-type p53 apoptotic activity that can be exploited, whereas TP53P153Δ and TP53Y220C encode two structurally related proteins with gain-of-function effects that predispose to head musculature ERMS. TP53P153Δ unexpectedly also predisposes to hedgehog-expressing medulloblastomas in the kRASG12D-driven ERMS-model.
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Affiliation(s)
- Jiangfei Chen
- Institute of Environmental Safety and Human Health, Wenzhou Medical UniversityWenzhouChina
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
| | - Kunal Baxi
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Amanda E Lipsitt
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Pediatrics, Division of Hematology Oncology, UT Health Sciences CenterSan AntonioUnited States
| | - Nicole Rae Hensch
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Long Wang
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Prethish Sreenivas
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Paulomi Modi
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Xiang Ru Zhao
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Antoine Baudin
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Biochemistry and Structural Biology, UT Health Sciences CenterSan AntonioUnited States
| | - Daniel G Robledo
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
| | - Abhik Bandyopadhyay
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
| | - Aaron Sugalski
- Department of Pediatrics, Division of Hematology Oncology, UT Health Sciences CenterSan AntonioUnited States
| | - Anil K Challa
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Biology, University of Alabama at BirminghamBirminghamUnited States
| | - Dias Kurmashev
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
| | - Andrea R Gilbert
- Department of Pathology and Laboratory Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Gail E Tomlinson
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Pediatrics, Division of Hematology Oncology, UT Health Sciences CenterSan AntonioUnited States
| | - Peter Houghton
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
| | - Yidong Chen
- Department of Population Health Sciences, UT Health Sciences CenterSan AntonioUnited States
| | - Madeline N Hayes
- Developmental and Stem Cell Biology, Hospital for Sick ChildrenTorontoCanada
| | - Eleanor Y Chen
- Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - David S Libich
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Biochemistry and Structural Biology, UT Health Sciences CenterSan AntonioUnited States
| | - Myron S Ignatius
- Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences CenterSan AntonioUnited States
- Department of Molecular Medicine, UT Health Sciences CenterSan AntonioUnited States
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3
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Alsharif H, Latimer MN, Perez KC, Alexander J, Rahman MM, Challa AK, Kim JA, Ramanadham S, Young M, Bhatnagar S. Loss of Brain Angiogenesis Inhibitor-3 (BAI3) G-Protein Coupled Receptor in Mice Regulates Adaptive Thermogenesis by Enhancing Energy Expenditure. Metabolites 2023; 13:711. [PMID: 37367869 PMCID: PMC10301052 DOI: 10.3390/metabo13060711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/24/2023] [Accepted: 05/18/2023] [Indexed: 06/28/2023] Open
Abstract
Effective energy expenditure is critical for maintaining body weight (BW). However, underlying mechanisms contributing to increased BW remain unknown. We characterized the role of brain angiogenesis inhibitor-3 (BAI3/ADGRB3), an adhesion G-protein coupled receptor (aGPCR), in regulating BW. A CRISPR/Cas9 gene editing approach was utilized to generate a whole-body deletion of the BAI3 gene (BAI3-/-). In both BAI3-/- male and female mice, a significant reduction in BW was observed compared to BAI3+/+ control mice. Quantitative magnetic imaging analysis showed that lean and fat masses were reduced in male and female mice with BAI3 deficiency. Total activity, food intake, energy expenditure (EE), and respiratory exchange ratio (RER) were assessed in mice housed at room temperature using a Comprehensive Lab Animal Monitoring System (CLAMS). While no differences were observed in the activity between the two genotypes in male or female mice, energy expenditure was increased in both sexes with BAI3 deficiency. However, at thermoneutrality (30 °C), no differences in energy expenditure were observed between the two genotypes for either sex, suggesting a role for BAI3 in adaptive thermogenesis. Notably, in male BAI3-/- mice, food intake was reduced, and RER was increased, but these attributes remained unchanged in the female mice upon BAI3 loss. Gene expression analysis showed increased mRNA abundance of thermogenic genes Ucp1, Pgc1α, Prdm16, and Elov3 in brown adipose tissue (BAT). These outcomes suggest that adaptive thermogenesis due to enhanced BAT activity contributes to increased energy expenditure and reduced BW with BAI3 deficiency. Additionally, sex-dependent differences were observed in food intake and RER. These studies identify BAI3 as a novel regulator of BW that can be potentially targeted to improve whole-body energy expenditure.
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Affiliation(s)
- Haifa Alsharif
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (H.A.); (K.C.P.); (J.A.); (M.M.R.); (J.-A.K.)
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Mary N. Latimer
- Division of Cardiovascular Disease, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.Y.)
| | - Katherine C. Perez
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (H.A.); (K.C.P.); (J.A.); (M.M.R.); (J.-A.K.)
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Justin Alexander
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (H.A.); (K.C.P.); (J.A.); (M.M.R.); (J.-A.K.)
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Md Mostafizur Rahman
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (H.A.); (K.C.P.); (J.A.); (M.M.R.); (J.-A.K.)
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Anil K. Challa
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Jeong-A. Kim
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (H.A.); (K.C.P.); (J.A.); (M.M.R.); (J.-A.K.)
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Sasanka Ramanadham
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Martin Young
- Division of Cardiovascular Disease, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.Y.)
| | - Sushant Bhatnagar
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (H.A.); (K.C.P.); (J.A.); (M.M.R.); (J.-A.K.)
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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4
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Santisteban MS, Applewhite L, Natvig L, Challa AK. CRISPR‐ethics in the Undergraduate Classroom using
CCR5
Gene. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r3919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Lydia Natvig
- University of North Carolina at PembrokePembrokeNC
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5
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Turner AN, Challa AK, Cooper KM. Student Perceptions of Authoring a Publication Stemming from a Course-Based Undergraduate Research Experience (CURE). CBE Life Sci Educ 2021; 20:ar46. [PMID: 34415196 PMCID: PMC8715815 DOI: 10.1187/cbe.21-02-0051] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/01/2021] [Accepted: 07/08/2021] [Indexed: 05/23/2023]
Abstract
Course-based undergraduate research experiences (CUREs) engage students in authentic research experiences in a course format and can sometimes result in the publication of that research. However, little is known about student-author perceptions of CURE publications. In this study, we examined how students perceive they benefit from authoring a CURE publication and what they believe is required for authorship of a manuscript in a peer-reviewed journal. All 16 students who were enrolled in a molecular genetics CURE during their first year of college participated in semistructured interviews during their fourth year. At the time of the interviews, students had been authors of a CURE publication for a year and a half. Students reported that they benefited personally and professionally from the publication. Students had varying perceptions of what is required for authorship, but every student thought that writing the manuscript was needed, and only two mentioned needing to approve the final draft. Additionally, we identified incomplete conceptions that students had about CURE publications. This work establishes student-perceived benefits from CURE publications and highlights the need for authorship requirements to be explicitly addressed in CUREs.
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Affiliation(s)
- Ashley N. Turner
- Department of Biology, School of Science, Jacksonville State University, Jacksonville, AL 36265
| | - Anil K. Challa
- Department of Biology, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Katelyn M. Cooper
- Research for Inclusive STEM Education Center, School of Life Sciences, Arizona State University, Tempe, AZ 85281
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6
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Challa AK, Stanford D, Allen A, Rasmussen L, Amanor FK, Raju SV. Validation of gene editing efficiency with CRISPR-Cas9 system directly in rat zygotes using electroporation mediated delivery and embryo culture. MethodsX 2021; 8:101419. [PMID: 34430314 PMCID: PMC8374522 DOI: 10.1016/j.mex.2021.101419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/16/2021] [Indexed: 11/19/2022] Open
Abstract
Successful use of the CRISPR-Cas9 system for gene manipulation relies on identifying effective and efficient guide RNA sequences (gRNAs). When the goal is to create transgenic animal/rodent models by knocking-in desired sequences using homology-directed repair (HDR), selecting effective guides becomes even more critical to minimize developmental time and resources. Currently, validation experiments for gRNAs for generating rat models are carried out using immortalized rat cells. However, there are several limitations with using such cell lines, including ploidy of the genome, non-predictive transfection efficiency, and the ability to identify gene modifications efficiently within diverse cell populations. Since embryos are authentic representatives of live animals compared to cell lines, validating CRISPR guides for their nuclease activity in freshly isolated embryos will provide greater accuracy of in vivo gene editing efficiency. In contrast to microinjections, delivery by electroporation is a more accessible method that can be simple and does not require special skills and equipment. We demonstrate an accessible workflow to either delete or edit target genes in vivo in rats using the efficient editing of a human mutation in alpha7 nicotinic acetylcholine receptor subunit (CHRNA7) ortholog using electroporation as a delivery method for CRISPR-Cas9 ribonucleoprotein complexes in rat embryos.Upon identifying CRISPR targets at the desired genetic alteration site, we designed homologydriven repair (HDR) templates for effective and easy identification of gene editing by Restriction Fragment Length Polymorphism (RFLP). Cultured rat embryos can be genotyped to assess CRISPR activity as seen by either presence of indels resulting from NHEJ or knock-in of repair template resulting from homology driven repair. Heteroduplex mobility assay (HMA) and Restriction Fragment Length Polymorphism (RFLP) of PCR products can be performed reliably and reproducibly at a low-cost.
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Affiliation(s)
- Anil K Challa
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Denise Stanford
- Cystic Fibrosis Research Center, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Antonio Allen
- Cystic Fibrosis Research Center, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lawrence Rasmussen
- Cystic Fibrosis Research Center, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ferdinand K Amanor
- Cystic Fibrosis Research Center, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - S Vamsee Raju
- Cystic Fibrosis Research Center, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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7
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Quiles JM, Pepin ME, Sunny S, Shelar SB, Challa AK, Dalley B, Hoidal JR, Pogwizd SM, Wende AR, Rajasekaran NS. Identification of Nrf2-responsive microRNA networks as putative mediators of myocardial reductive stress. Sci Rep 2021; 11:11977. [PMID: 34099738 PMCID: PMC8184797 DOI: 10.1038/s41598-021-90583-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 04/14/2021] [Indexed: 12/30/2022] Open
Abstract
Although recent advances in the treatment of acute coronary heart disease have reduced mortality rates, few therapeutic strategies exist to mitigate the progressive loss of cardiac function that manifests as heart failure. Nuclear factor, erythroid 2 like 2 (Nfe2l2, Nrf2) is a transcriptional regulator that is known to confer transient myocardial cytoprotection following acute ischemic insult; however, its sustained activation paradoxically causes a reductive environment characterized by excessive antioxidant activity. We previously identified a subset of 16 microRNAs (miRNA) significantly diminished in Nrf2-ablated (Nrf2-/-) mouse hearts, leading to the hypothesis that increasing levels of Nrf2 activation augments miRNA induction and post-transcriptional dysregulation. Here, we report the identification of distinct miRNA signatures (i.e. "reductomiRs") associated with Nrf2 overexpression in a cardiac-specific and constitutively active Nrf2 transgenic (caNrf2-Tg) mice expressing low (TgL) and high (TgH) levels. We also found several Nrf2 dose-responsive miRNAs harboring proximal antioxidant response elements (AREs), implicating these "reductomiRs" as putative meditators of Nrf2-dependent post-transcriptional regulation. Analysis of mRNA-sequencing identified a complex network of miRNAs and effector mRNAs encoding known pathological hallmarks of cardiac stress-response. Altogether, these data support Nrf2 as a putative regulator of cardiac miRNA expression and provide novel candidates for future mechanistic investigation to understand the relationship between myocardial reductive stress and cardiac pathophysiology.
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Affiliation(s)
- Justin M Quiles
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mark E Pepin
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sini Sunny
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sandeep B Shelar
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Anil K Challa
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brian Dalley
- Huntsman Cancer Center-Genomic Core Facility, University of Utah, Salt Lake City, UT, USA
| | - John R Hoidal
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, USA
- Division of Pulmonary Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Steven M Pogwizd
- Comprehensive Cardiovascular Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Adam R Wende
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Namakkal S Rajasekaran
- Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, USA.
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, USA.
- Division of Pulmonary Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, USA.
- Division of Molecular and Cellular Pathology, Department of Pathology, Center for Free Radical Biology, The University of Alabama at Birmingham, BMR2 Room 533, 901 19th Street South, Birmingham, AL, 35294-2180, USA.
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8
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Lipsitt A, Hensch NR, Moreno-Campos R, Baxi K, Chen J, Challa AK, Chen EY, Ignatius MS. Zebrafish Tumor Graft Transplantation to Grow Tumors In Vivo That Engraft Poorly as Single Cell Suspensions. Zebrafish 2021; 18:293-296. [PMID: 34030492 DOI: 10.1089/zeb.2021.0006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Angiosarcoma is a clinically aggressive tumor with a high rate of mortality. It can arise in vascular or lymphatic tissues, involve any part of the body, and aggressively spread locally or metastasize. Angiosarcomas spontaneously develop in the tp53 deleted (tp53del/del) zebrafish mutant. However, established protocols for tumor dissection and transplantation of single cell suspensions of angiosarcoma tumors result in inferior implantation rates. To resolve these complications, we developed a new tumor grafting technique for engraftment of angiosarcoma and similar tumors in zebrafish, which maintains the tumor microenvironment and has superior rates of engraftment.
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Affiliation(s)
- Amanda Lipsitt
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
- Department of Pediatrics, Division of Hematology Oncology, UT Health Sciences Center, San Antonio, Texas, USA
| | - Nicole R Hensch
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
| | - Rodrigo Moreno-Campos
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
| | - Kunal Baxi
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
| | - Jiangfei Chen
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, P.R. China
| | - Anil K Challa
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
- Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Eleanor Y Chen
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Myron S Ignatius
- Department of Molecular Medicine, Greehey Children's Cancer Research Institute (GCCRI), UT Health Sciences Center, San Antonio, Texas, USA
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9
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Icyuz M, Zhang F, Fitch MP, Joyner MR, Challa AK, Sun LY. Physiological and metabolic characteristics of novel double-mutant female mice with targeted disruption of both growth hormone-releasing hormone and growth hormone receptor. Aging Cell 2021; 20:e13339. [PMID: 33755309 PMCID: PMC8045953 DOI: 10.1111/acel.13339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 12/27/2020] [Accepted: 01/12/2021] [Indexed: 12/19/2022] Open
Abstract
Mice with disruptions of growth hormone-releasing hormone (GHRH) or growth hormone receptor (GHR) exhibit similar phenotypes of prolonged lifespan and delayed age-related diseases. However, these two models respond differently to calorie restriction indicating that they might carry different and/or independent mechanisms for improved longevity and healthspan. In order to elucidate these mechanisms, we generated GHRH and GHR double-knockout mice (D-KO). In the present study, we focused specifically on the characteristics of female D-KO mice. The D-KO mice have reduced body weight and enhanced insulin sensitivity compared to wild-type (WT) controls. Growth retardation in D-KO mice is accompanied by decreased GH expression in pituitary, decreased circulating IGF-1, increased high-molecular-weight (HMW) adiponectin, and leptin hormones compared to WT controls. Generalized linear model-based regression analysis, which controls for body weight differences between D-KO and WT groups, shows that D-KO mice have decreased lean mass, bone mineral density, and bone mineral content, but increased adiposity. Indirect calorimetry markers including oxygen consumption, carbon dioxide production, and energy expenditure were significantly lower in D-KO mice relative to the controls. In comparison with WT mice, the D-KO mice displayed reduced respiratory exchange ratio (RER) values only during the light cycle, suggesting a circadian-related metabolic shift toward fat utilization. Interestingly, to date survival data suggest extended lifespan in D-KO female mice.
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Affiliation(s)
- Mert Icyuz
- Department of Biology University of Alabama at Birmingham Birmingham Alabama USA
| | - Fang Zhang
- Department of Biology University of Alabama at Birmingham Birmingham Alabama USA
| | - Michael P. Fitch
- Department of Biology University of Alabama at Birmingham Birmingham Alabama USA
| | - Matthew R. Joyner
- Department of Biology University of Alabama at Birmingham Birmingham Alabama USA
| | - Anil K. Challa
- Department of Biology University of Alabama at Birmingham Birmingham Alabama USA
| | - Liou Y. Sun
- Department of Biology University of Alabama at Birmingham Birmingham Alabama USA
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10
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Brinkley G, Nam H, Shim E, Kirkman R, Kundu A, Karki S, Heidarian Y, Tennessen JM, Liu J, Locasale JW, Guo T, Wei S, Gordetsky J, Johnson-Pais TL, Absher D, Rakheja D, Challa AK, Sudarshan S. Teleological role of L-2-hydroxyglutarate dehydrogenase in the kidney. Dis Model Mech 2020; 13:dmm045898. [PMID: 32928875 PMCID: PMC7710027 DOI: 10.1242/dmm.045898] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022] Open
Abstract
L-2-hydroxyglutarate (L-2HG) is an oncometabolite found elevated in renal tumors. However, this molecule might have physiological roles that extend beyond its association with cancer, as L-2HG levels are elevated in response to hypoxia and during Drosophila larval development. L-2HG is known to be metabolized by L-2HG dehydrogenase (L2HGDH), and loss of L2HGDH leads to elevated L-2HG levels. Despite L2HGDH being highly expressed in the kidney, its role in renal metabolism has not been explored. Here, we report our findings utilizing a novel CRISPR/Cas9 murine knockout model, with a specific focus on the role of L2HGDH in the kidney. Histologically, L2hgdh knockout kidneys have no demonstrable histologic abnormalities. However, GC-MS metabolomics demonstrates significantly reduced levels of the TCA cycle intermediate succinate in multiple tissues. Isotope labeling studies with [U-13C] glucose demonstrate that restoration of L2HGDH in renal cancer cells (which lowers L-2HG) leads to enhanced incorporation of label into TCA cycle intermediates. Subsequent biochemical studies demonstrate that L-2HG can inhibit the TCA cycle enzyme α-ketoglutarate dehydrogenase. Bioinformatic analysis of mRNA expression data from renal tumors demonstrates that L2HGDH is co-expressed with genes encoding TCA cycle enzymes as well as the gene encoding the transcription factor PGC-1α, which is known to regulate mitochondrial metabolism. Restoration of PGC-1α in renal tumor cells results in increased L2HGDH expression with a concomitant reduction in L-2HG levels. Collectively, our analyses provide new insight into the physiological role of L2HGDH as well as mechanisms that promote L-2HG accumulation in disease states.
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Affiliation(s)
- Garrett Brinkley
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hyeyoung Nam
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Eunhee Shim
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Richard Kirkman
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Anirban Kundu
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Suman Karki
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Yasaman Heidarian
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Jason M Tennessen
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Juan Liu
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA
| | - Tao Guo
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Shi Wei
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jennifer Gordetsky
- Departments of Pathology and Urology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Devin Absher
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Dinesh Rakheja
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Anil K Challa
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Sunil Sudarshan
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Birmingham VA Medical Center, Birmingham, AL 35233, USA
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11
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Shanmugam G, Challa AK, Devarajan A, Athmanathan B, Litovsky SH, Krishnamurthy P, Davidson CJ, Rajasekaran NS. Exercise Mediated Nrf2 Signaling Protects the Myocardium From Isoproterenol-Induced Pathological Remodeling. Front Cardiovasc Med 2019; 6:68. [PMID: 31245386 PMCID: PMC6563599 DOI: 10.3389/fcvm.2019.00068] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 05/07/2019] [Indexed: 12/14/2022] Open
Abstract
Although exercise derived activation of Nrf2 signaling augments myocardial antioxidant signaling, the molecular mechanisms underlying the benefits of moderate exercise training (MET) in the heart remain elusive. Here we hypothesized that exercise training stabilizes Nrf2-dependent antioxidant signaling, which then protects the myocardium from isoproterenol-induced damage. The present study assessed the effects of 6 weeks of MET on the Nrf2/antioxidant function, glutathione redox state, and injury in the myocardium of C57/BL6J mice that received isoproterenol (ISO; 50 mg/kg/day for 7 days). ISO administration significantly reduced the Nrf2 promoter activity (p < 0.05) and downregulated the expression of cardiac antioxidant genes (Gclc, Nqo1, Cat, Gsr, and Gst-μ) in the untrained (UNT) mice. Furthermore, increased oxidative stress with severe myocardial injury was evident in UNT+ISO when compared to UNT mice receiving PBS under basal condition. Of note, MET stabilized the Nrf2-promoter activity and upheld the expression of Nrf2-dependent antioxidant genes in animals receiving ISO, and attenuated the oxidative stress-induced myocardial damage. Echocardiography analysis revealed impaired diastolic ventricular function in UNT+ISO mice, but this was partially normalized in the MET animals. Interestingly, while there was a marginal reduction in ubiquitinated proteins in MET mice that received ISO, the pathological signs were attenuated along with near normal cardiac function in response to exercise training. Thus, moderate intensity exercise training conferred protection against ISO-induced myocardial injury by augmentation of Nrf2-antioxidant signaling and attenuation of isoproterenol-induced oxidative stress.
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Affiliation(s)
- Gobinath Shanmugam
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Anil K. Challa
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Asokan Devarajan
- Department of Medicine, Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Baskaran Athmanathan
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Silvio H. Litovsky
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Prasanna Krishnamurthy
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Christopher J. Davidson
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, United States
| | - Namakkal Soorappan Rajasekaran
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, United States
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, Salt Lake City, UT, United States
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, United States
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12
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Wolyniak MJ, Austin S, Bloodworth LF, Carter D, Harrison SH, Hoage T, Hollis-Brown L, Jefferson F, Krufka A, Safadi-Chamberlin F, Santisteban MS, Soneral P, VanWinkle B, Challa AK. Integrating CRISPR-Cas9 Technology into Undergraduate Courses: Perspectives from a National Science Foundation (NSF) Workshop for Undergraduate Faculty, June 2018. J Microbiol Biol Educ 2019; 20:jmbe-20-19. [PMID: 31160943 PMCID: PMC6508915 DOI: 10.1128/jmbe.v20i1.1702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/23/2019] [Indexed: 05/24/2023]
Abstract
As CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 technology becomes more mainstream in life science research, it becomes critical for undergraduate instructors to devise engaging ways to bring the technology into their classrooms. To help meet this challenge, the National Science Foundation sponsored a workshop for undergraduate instructors in June 2018 at The Ohio State University in conjunction with the annual Association of Biology Laboratory Educators meeting based on a workflow developed by the workshop's facilitators. Over the course of two and a half days, participants worked through a modular workflow for the use of CRISPR-Cas9 in a course-based (undergraduate) research experience (CURE) setting while discussing the barriers each of their institutions had to implementing such work, and how such barriers could be overcome. The result of the workshop was a team with newfound energy and confidence to implement CRISPR-Cas9 technology in their courses and the development of a community of undergraduate educators dedicated to supporting each other in the implementation of the workflow either in a CURE or modular format. In this article, we review the activities and discussions from the workshop that helped each participant devise their own tailored approaches of how best to bring this exciting new technology into their classes.
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Affiliation(s)
| | - Shane Austin
- Department of Biological and Chemical Sciences, The University of the West Indies at Cave Hill, Bridgetown, BB11000, Barbados
| | | | - Dawn Carter
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY 14623
| | - Scott H. Harrison
- Department of Biology, North Carolina A&T State University, Greensboro, NC 27411
| | - Tiffany Hoage
- Department of Biology, University of Wisconsin—Stout, Menomonie, WI 54751
| | - Lisa Hollis-Brown
- Department of Biology, Pikes Peak Community College, Colorado Springs, CO 80906
| | - Felicia Jefferson
- Department of Biology, Fort Valley State University, Fort Valley, GA 31030
| | - Alison Krufka
- Department of Biological Sciences, Rowan University, Glassboro, NJ 08028
| | - Farida Safadi-Chamberlin
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523
| | - Maria S. Santisteban
- Department of Biology, University of North Carolina at Pembroke, Pembroke, NC 28372
| | - Paula Soneral
- Department of Biological Sciences, Bethel University, St. Paul, MN 55112
| | - Beth VanWinkle
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY 14623
| | - Anil K. Challa
- Department of Biology, The University of Alabama Birmingham, Birmingham, AL 35294
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13
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Chumley P, Zhou J, Mrug S, Chacko B, Parant JM, Challa AK, Wilson LS, Berryhill TF, Barnes S, Kesterson RA, Bell PD, Darley-Usmar VM, Yoder BK, Mrug M. Truncating PKHD1 and PKD2 mutations alter energy metabolism. Am J Physiol Renal Physiol 2018; 316:F414-F425. [PMID: 30566001 PMCID: PMC6442375 DOI: 10.1152/ajprenal.00167.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Deficiency in polycystin 1 triggers specific changes in energy metabolism. To determine whether defects in other human cystoproteins have similar effects, we studied extracellular acidification and glucose metabolism in human embryonic kidney (HEK-293) cell lines with polycystic kidney and hepatic disease 1 ( PKHD1) and polycystic kidney disease (PKD) 2 ( PKD2) truncating defects along multiple sites of truncating mutations found in patients with autosomal recessive and dominant PKDs. While neither the PKHD1 or PKD2 gene mutations nor their position enhanced cell proliferation rate in our cell line models, truncating mutations in these genes progressively increased overall extracellular acidification over time ( P < 0.001 for PKHD1 and PKD2 mutations). PKHD1 mutations increased nonglycolytic acidification rate (1.19 vs. 1.03, P = 0.002), consistent with an increase in tricarboxylic acid cycle activity or breakdown of intracellular glycogen. In addition, they increased basal and ATP-linked oxygen consumption rates [7.59 vs. 5.42 ( P = 0.015) and 4.55 vs. 2.98 ( P = 0.004)]. The PKHD1 and PKD2 mutations also altered mitochondrial morphology, resembling the effects of polycystin 1 deficiency. Together, these data suggest that defects in major PKD genes trigger changes in mitochondrial energy metabolism. After validation in in vivo models, these initial observations would indicate potential benefits of targeting energy metabolism in the treatment of PKDs.
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Affiliation(s)
- Phillip Chumley
- Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | - Juling Zhou
- Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | - Sylvie Mrug
- Department of Psychology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Balu Chacko
- Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | - John M Parant
- Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham , Birmingham, Alabama
| | - Anil K Challa
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Landon S Wilson
- Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham , Birmingham, Alabama
| | - Taylor F Berryhill
- Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham , Birmingham, Alabama
| | - Stephen Barnes
- Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham , Birmingham, Alabama.,Department of Pharmacology and Toxicology, University of Alabama at Birmingham , Birmingham, Alabama.,Department of Genetics, University of Alabama at Birmingham , Birmingham, Alabama
| | - Robert A Kesterson
- Department of Genetics, University of Alabama at Birmingham , Birmingham, Alabama
| | - P Darwin Bell
- Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | | | - Bradley K Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Alabama
| | - Michal Mrug
- Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama.,Department of Veterans Affairs Medical Center , Birmingham, Alabama
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14
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Turner AN, Andersen RS, Bookout IE, Brashear LN, Davis JC, Gahan DM, Davis JC, Gotham JP, Hijaz BA, Kaushik AS, Mcgill JB, Miller VL, Moseley ZP, Nowell CL, Patel RK, Rodgers MC, Patel RK, Shihab YA, Walker AP, Glover SR, Foster SD, Challa AK. Analysis of novel domain-specific mutations in the zebrafish ndr2/ cyclops gene generated using CRISPR-Cas9 RNPs. J Genet 2018. [PMID: 30555080 DOI: 10.1101/277715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Nodal-related protein (ndr2) is amember of the transforming growth factor type β superfamily of factors and is required for ventral midline patterning of the embryonic central nervous system in zebrafish. In humans, mutations in the gene encoding nodal cause holoprosencephaly and heterotaxy. Mutations in the ndr2 gene in the zebrafish (Danio rerio) lead to similar phenotypes, including loss of the medial floor plate, severe deficits in ventral forebrain development and cyclopia. Alleles of the ndr2 gene have been useful in studying patterning of ventral structures of the central nervous system. Fifteen different ndr2 alleles have been reported in zebrafish, of which eight were generated using chemical mutagenesis, four were radiation-induced and the remaining alleles were obtained via random insertion, gene targeting (TALEN) or unknown methods. Therefore, most mutation sites were random and could not be predicted a priori. Using the CRISPR-Cas9 system from Streptococcus pyogenes, we targeted distinct regions in all three exons of zebrafish ndr2 and observed cyclopia in the injected (G0) embryos.We show that the use of sgRNA-Cas9 ribonucleoprotein (RNP) complexes can cause penetrant cyclopic phenotypes in injected (G0) embryos. Targeted polymerase chain reaction amplicon analysis using Sanger sequencing showed that most of the alleles had small indels resulting in frameshifts. The sequence information correlates with the loss of ndr2 activity. In this study, we validate multiple CRISPR targets using an in vitro nuclease assay and in vivo analysis using embryos. We describe one specific mutant allele resulting in the loss of conserved terminal cysteine-coding sequences. This study is another demonstration of the utility of the CRISPR-Cas9 system in generating domain-specific mutations and provides further insights into the structure-function of the ndr2 gene.
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Affiliation(s)
- Ashley N Turner
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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15
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Foster SD, Glover SR, Turner AN, Chatti K, Challa AK. A mixing heteroduplex mobility assay (mHMA) to genotype homozygous mutants with small indels generated by CRISPR-Cas9 nucleases. MethodsX 2018; 6:1-5. [PMID: 30591915 PMCID: PMC6305891 DOI: 10.1016/j.mex.2018.11.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 11/26/2018] [Indexed: 11/17/2022] Open
Affiliation(s)
- Samantha D Foster
- Science and Technology Honors Program, University of Alabama at Birmingham (UAB), United States of America.,Undergraduate Neuroscience Program, UAB, United States of America
| | - Sarah R Glover
- Science and Technology Honors Program, University of Alabama at Birmingham (UAB), United States of America.,Department of Biology, UAB, United States of America
| | | | - Kiranam Chatti
- Dr. Reddy's Institute of Life Sciences, Hyderabad, India
| | - Anil K Challa
- Department of Genetics, UAB, United States of America
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16
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Lambert LJ, Challa AK, Niu A, Zhou L, Tucholski J, Johnson MS, Nagy TR, Eberhardt AW, Estep PN, Kesterson RA, Grams JM. Increased trabecular bone and improved biomechanics in an osteocalcin-null rat model created by CRISPR/Cas9 technology. Dis Model Mech 2016; 9:1169-1179. [PMID: 27483347 PMCID: PMC5087831 DOI: 10.1242/dmm.025247] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 07/19/2016] [Indexed: 11/20/2022] Open
Abstract
Osteocalcin, also known as bone γ-carboxyglutamate protein (Bglap), is expressed by osteoblasts and is commonly used as a clinical marker of bone turnover. A mouse model of osteocalcin deficiency has implicated osteocalcin as a mediator of changes to the skeleton, endocrine system, reproductive organs and central nervous system. However, differences between mouse and human osteocalcin at both the genome and protein levels have challenged the validity of extrapolating findings from the osteocalcin-deficient mouse model to human disease. The rat osteocalcin (Bglap) gene locus shares greater synteny with that of humans. To further examine the role of osteocalcin in disease, we created a rat model with complete loss of osteocalcin using the CRISPR/Cas9 system. Rat osteocalcin was modified by injection of CRISPR/Cas9 mRNA into the pronuclei of fertilized single cell Sprague-Dawley embryos, and animals were bred to homozygosity and compound heterozygosity for the mutant alleles. Dual-energy X-ray absorptiometry (DXA), glucose tolerance testing (GTT), insulin tolerance testing (ITT), microcomputed tomography (µCT), and a three-point break biomechanical assay were performed on the excised femurs at 5 months of age. Complete loss of osteocalcin resulted in bones with significantly increased trabecular thickness, density and volume. Cortical bone volume and density were not increased in null animals. The bones had improved functional quality as evidenced by an increase in failure load during the biomechanical stress assay. Differences in glucose homeostasis were observed between groups, but there were no differences in body weight or composition. This rat model of complete loss of osteocalcin provides a platform for further understanding the role of osteocalcin in disease, and it is a novel model of increased bone formation with potential utility in osteoporosis and osteoarthritis research. Summary: A complete null of osteocalcin, generated by the CRISPR/Cas9 system, results in an increase in trabecular bone, increased bone strength and altered glucose homeostasis in Sprague-Dawley rats.
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Affiliation(s)
- Laura J Lambert
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Anil K Challa
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Aidi Niu
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lihua Zhou
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Janusz Tucholski
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Maria S Johnson
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Tim R Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Alan W Eberhardt
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Patrick N Estep
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Robert A Kesterson
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jayleen M Grams
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA Department of Surgery, Birmingham VA Medical Center, Birmingham, AL 35233, USA
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17
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Challa AK, McWhorter ML, Wang C, Seeger MA, Beattie CE. Robo3 isoforms have distinct roles during zebrafish development. Mech Dev 2006; 122:1073-86. [PMID: 16129585 DOI: 10.1016/j.mod.2005.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Accepted: 06/17/2005] [Indexed: 11/16/2022]
Abstract
Roundabout (Robo) receptors and their secreted ligand Slits have been shown to function in a number of developmental events both inside and outside of the nervous system. We previously cloned zebrafish robo orthologs to gain a better understanding of Robo function in vertebrates. Further characterization of one of these orthologs, robo3, has unveiled the presence of two distinct isoforms, robo3 variant 1 (robo3var1) and robo3 variant 2 (robo3var2). These two isoforms differ only in their 5'-ends with robo3var1, but not robo3var2, containing a canonical signal sequence. Despite this difference, both forms accumulate on the cell surface. Both isoforms are contributed maternally and exhibit unique and dynamic gene expression patterns during development. Functional analysis of robo3 isoforms using an antisense gene knockdown strategy suggests that Robo3var1 functions in motor axon pathfinding, whereas Robo3var2 appears to function in dorsoventral cell fate specification. This study reveals a novel function for Robo receptors in specifying ventral cell fates during vertebrate development.
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Affiliation(s)
- Anil K Challa
- Center for Molecular Neurobiology, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
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18
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Abstract
Sialic acids are sometimes 9-O-acetylated in a developmentally regulated and cell-type-specific manner. Cells naturally expressing the disialoganglioside GD3 often O-acetylate the terminal sialic acid residue, giving 9-O-acetyl-GD3 (9AcGD3), a marker of neural differentiation and malignant transformation. We also reported that Chinese hamster ovary cells transfected with GD3 synthase can spontaneously O-acetylate some of the newly synthesized GD3. It is unclear whether such phenomena result from induction of the 9-O-acetylation machinery and whether induction is caused by the GD3 synthase protein or by the GD3 molecule itself. We now show that exogenously added GD3 rapidly incorporates into the plasma membrane of Chinese hamster ovary cells, and 9AcGD3 is detected after approximately 6 h. The incorporated GD3 and newly synthesized 9AcGD3 have a half-life of approximately 24 h. This phenomenon is also seen in other cell types, such as human diploid fibroblasts. Inhibitors of gene transcription, protein translation, or endoplasmic reticulum-to-Golgi transport each prevent induction of 9-O-acetylation, without affecting GD3 incorporation. Inhibition of the initial clathrin-independent internalization of incorporated GD3 also blocks induction of 9-O-acetylation. Thus, new synthesis of one or more components of the 9-O-acetylation machinery is induced by incorporation and internalization of GD3. Prepriming with structurally related gangliosides fails to accelerate the onset of 9-O-acetylation of subsequently added GD3, indicating a requirement for specific recognition of GD3. To our knowledge, this is the first example wherein a newly expressed or exogenously introduced ganglioside induces de novo synthesis of an enzymatic machinery to modify itself, and the first evidence for a mechanism of induction of sialic acid O-acetylation.
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Affiliation(s)
- Helen Y Chen
- Glycobiology Research and Training Center, Department of Medicine, University of California San Diego, La Jolla, California 92093-0687, USA
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19
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Abstract
The Roundabout (Robo) family of receptors and their extracellular ligands, the Slit protein family, play important roles in repulsive axon guidance. First identified in Drosophila, Robo receptors form an evolutionarily conserved sub-family of the immunoglobulin (Ig) superfamily that are characterized by the presence of five Ig repeats and three fibronectin-type III repeats in the extracellular domain, a transmembrane domain, and a cytoplasmic domain with several conserved motifs that play important roles in Robo-mediated signaling (Cell 92 (1998) 205; Cell 101 (2000) 703). Robo family members have now been identified in C. elegans, Xenopus, rat, mouse, and human (Cell 92 (1998) 205; Cell 92 (1998) 217; Cell 96 (1999) 807; Dev. Biol. 207 (1999) 62). Furthermore, multiple robo genes have been described in Drosophila, rat, mouse and humans, raising the possibility of potential redundancy and diversity in robo gene function. As a first step in elucidating the role of Robo receptors during vertebrate development, we identified and characterized two Robo family members from zebrafish. We named these zebrafish genes robo1 and robo3, reflecting their amino acid sequence similarity to other vertebrate robo genes. Both genes are dynamically expressed in the developing nervous system in distinct patterns. robo3 is expressed during the first day of development in the hindbrain and spinal cord and is later expressed in the tectum and retina. robo1 nervous system expression appears later in development and is more restricted. Moreover, both genes are expressed in non-neuronal tissues consistent with additional roles for these genes during development.
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Affiliation(s)
- A K Challa
- Neurobiotechnology Center, The Ohio State University, Columbus, OH 43210, USA
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