Publications by authors named "Anil K Challa"

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 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.

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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.

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In embryonal rhabdomyosarcoma (ERMS) and generally in sarcomas, the role of wild-type and loss- or gain-of-function 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 , yet mutations when present are associated with worse prognosis.

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The application of CRISPR has greatly facilitated genotype-phenotype studies of human disease models. In this protocol, we describe CRISPR-Cas9-induced gene knockout in zebrafish, utilizing purified Cas9 protein and -transcribed sgRNA. This protocol targets the PHLPP1 gene in an Indian wild-caught strain, but is broadly applicable.

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Nuclear factor, erythroid 2 like 2 (Nfe2l2 or Nrf2), is a transcription factor that protects cells by maintaining a homeostatic redox state during stress. The constitutive expression of Nrf2 (CaNrf2-TG) was previously shown to be pathological to the heart over time. We tested a hypothesis that the cardiac-specific expression of full length Nrf2 (mNrf2-TG) would moderately increase the basal antioxidant defense, triggering a pro-reductive environment leading to adaptive cardiac remodeling.

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Objective: Hydroxyacylglutathione hydrolase (aka as GLO-2) is a component of the glyoxalase pathway involved in the detoxification of the reactive oxoaldehydes, glyoxal and methylglyoxal. These reactive metabolites have been linked to a variety of pathological conditions, including diabetes, cancer and heart disease and may be involved in the aging process. The objective of this study was to generate a mouse model deficient in GLO-2 to provide insight into the function of GLO-2 and to determine if it is potentially linked to endogenous oxalate synthesis which could influence urinary oxalate excretion.

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The development of the heart follows a synergic action of several signaling pathways during gestational, pre- & postnatal stages. The current study aimed to investigate whether the myocardium experiences transcriptional changes during the transition from post-natal to adult hood stages. Herein, we used C57/B16/J mice at 4 (28- days; post-natal/PN) and 20 weeks (adulthood/AH) of ages and employed the next generation RNAseq (NGS) to profile the transcriptome and echocardiography analysis to monitor the structural/functional changes in the heart.

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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.

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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.

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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.

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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 deleted () zebrafish mutant.

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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).

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Undergraduate microbiology curriculum should be amenable to periodic changes to incorporate new developments and ideas. The curriculum should be used not merely as a way to disseminate facts but also as a way to allow students to experience the process of science. In the context of undergraduate microbiology education in Osmania University (Hyderabad, India), existing curriculum does not explicitly allow students to engage in deeper understanding of concepts and understanding of the process of science, both in lecture and laboratory courses.

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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 larval development. L-2HG is known to be metabolized by L-2HG dehydrogenase (L2HGDH), and loss of L2HGDH leads to elevated L-2HG levels.

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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).

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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.

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Nuclear factor (erythroid-derived 2)-like 2 (NFE2L2/Nrf2) is an inducible transcription factor that is essential for maintenance of redox signaling in response to stress. This suggests that if Nrf2 expression response could be enhanced for a defined physiological pro-oxidant stress then it would be protective. This has important implications for the therapeutic manipulation of the Keap1/Nrf2 signaling pathway which is now gaining a lot of attention.

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The development of gene editing technologies, especially the CRISPR-Cas9 system, has been pivotal for understanding the functional role of proteins. Rapid and efficient genotyping methods are necessary to screen for generated mutations and streamline the isolation of homozygotes. CRISPR-Cas9 system targeting a single site in the gene typically results in small indels.

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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.

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Article Synopsis
  • * The study successfully utilized the CRISPR-Cas9 system to target and induce specific mutations in the ndr2 gene in zebrafish embryos, leading to the expected cyclopic phenotypes.
  • * Analysis revealed that most induced mutations resulted in small changes that disrupted normal gene function, enhancing the understanding of ndr2's role and demonstrating the effectiveness of CRISPR technology for targeted genetic studies.
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The key negative regulatory gene of the RAS pathway, , is mutated or deleted in numerous cancer types and is associated with increased cancer risk and drug resistance. Even though women with neurofibromatosis (germline mutations) have a substantially increased breast cancer risk at a young age and is commonly mutated in sporadic breast cancers, we have a limited understanding of the role of in breast cancer. We utilized CRISPR-Cas9 gene editing to create rat models to evaluate the effect of deficiency on tumorigenesis.

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Genetic analysis in model systems can provide a rich context for conceptual understanding of gene structure, regulation, and function. With an intent to create a rich learning experience in molecular genetics, we developed a semester-long course-based undergraduate research experience (CURE) using the CRISPR-Cas9 gene editing system to disrupt specific genes in the zebrafish. The course was offered to freshman students; nine students worked in four groups (two to three members per group) to design, synthesize, and test the nuclease activity of the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/sgRNAs for targeted disruption of specific genes in the zebrafish.

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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.

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Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development.

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Tyrosinase is a key enzyme in melanin biosynthesis. Mutations in the gene encoding tyrosinase (Tyr) cause oculocutaneous albinism (OCA1) in humans. Alleles of the Tyr gene have been useful in studying pigment biology and coat color formation.

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