Genome-edited zebrafish model of ABCC8 loss-of-function disease

2021 ◽  
Author(s):  
Jennifer M Ikle ◽  
Robert C. Tryon ◽  
Soma S. Singareddy ◽  
Nathaniel W. York ◽  
Maria S. Remedi ◽  
...  
Keyword(s):  
Mouse Models ◽  
Neonatal Diabetes ◽  
Katp Channels ◽  
Pancreatic Disease ◽  
Loss Of Function ◽  
Zebrafish Model ◽  
Abcc8 Gene ◽  
Truncation Mutation ◽  
Knockout Animals ◽  
Sur1 Knockout Mice

KATP channel gain- (GOF) and loss-of-function (LOF) mutations underlie human neonatal diabetes mellitus (NDM) and hyperinsulinism (HI), respectively. Genetically modified mice with transgenic overexpression of GOF mutations recapitulate many features of human NDM but, importantly, there are currently no gene knock-in mouse models of GOF mutations. Moreover, while transgenic mice expressing incomplete KATP LOF do reiterate mild hyperinsulinism, KATP knockout animals do not exhibit persistent hyperinsulinism. We have shown that islet excitability and glucose homeostasis are regulated by identical KATP channels in zebrafish. SUR1 truncation mutation (K499X) was introduced into the abcc8 gene to explore the possibility of using zebrafish for modeling human NDM and HI. Patch-clamp analysis confirmed complete absence of channel activity in β-cells from K499X (SUR1-/-) fish. No difference in random blood glucose was detected in heterozygous SUR1+/- fish, nor in homozygous SUR1-/- fish, mimicking findings in SUR1 knockout mice. Mutant fish did however, demonstrate impaired glucose tolerance, similar to partial LOF mouse models. In paralleling features of mammalian diabetes and hyperinsulinism resulting from equivalent gain- or loss-of-function mutations, these gene-edited animals provide valid zebrafish models of KATP LOF driven-dependent pancreatic disease.

Transient neonatal diabetes due to a disease causing novel variant in the ATP-binding cassette subfamily C member 8 (ABCC8) gene unmasks maturity-onset diabetes of the young (MODY) diabetes cases within a family

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Eleni Z Giannopoulou ◽  
Olga Ovcarov ◽  
Elisa De Franco ◽  
Fabian Kassberger ◽  
Susanne Nusser ◽  
...  
Keyword(s):  
Autoimmune Diabetes ◽  
Family Members ◽  
Neonatal Diabetes ◽  
Atp Binding ◽  
Adult Onset ◽  
Family History Of Diabetes ◽  
Abcc8 Gene ◽  
Onset Diabetes ◽  
Novel Variant ◽  
Atp Binding Cassette

AbstractObjectivesNeonatal diabetes mellitus (NDM) is a rare monogenic diabetes form, occurring mainly from ATP-binding cassette subfamily C member 8 (ABCC8) and KCNJ11 mutations. ABCC8 mutations have also been found to cause adult-onset diabetes. What is new?: •Novel ABCC8 mutation in an NDM case •Heterogeneous clinical presentation of diabetes and response to sulfonylurea therapy among family members with the same ABCC8 mutation.Case presentationWe report the case of a newborn with NDM and a heterozygous ABCC8 novel variant (c.3835G>A), successfully treated with sulfonylurea. The same ABCC8 variant was found in two other family members, already treated for type 2 diabetes.ConclusionsThis case demonstrates the variable phenotypic presentation of diabetes due to a novel ABCC8 mutation (c.3835G>A), ranging from transient NDM to adult-onset, insulin-demanding diabetes, among family members. Genetic testing in young individuals with a strong family history of diabetes, presenting with non-autoimmune diabetes is recommended as it can determine prognosis and treatment of affected family members.

scholarly journals Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos

2021 ◽  
Vol 22 (12) ◽  
pp. 6497
Author(s):  
Anna Ghilardi ◽  
Alberto Diana ◽  
Renato Bacchetta ◽  
Nadia Santo ◽  
Miriam Ascagni ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Hair Cells ◽  
Muscle Fibers ◽  
Underlying Mechanism ◽  
Loss Of Function ◽  
Zebrafish Model ◽  
Developmental Defects ◽  
Inner Ear Development ◽  
Syndromic Hearing Loss

The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.

The use of glimepiride for the treatment of neonatal diabetes mellitus caused by a novel mutation of the ABCC8 gene

2020 ◽  
Vol 33 (12) ◽  
pp. 1605-1608
Author(s):  
Xiao Qin ◽  
Jingzi Zhong ◽  
Dan Lan
Keyword(s):  
Diabetes Mellitus ◽  
Novel Mutation ◽  
Male Infant ◽  
Neonatal Diabetes ◽  
Monogenic Diabetes ◽  
Neonatal Diabetes Mellitus ◽  
Rare Form ◽  
Case Presentation ◽  
Abcc8 Gene

AbstractObjectivesNeonatal diabetes mellitus (NDM) is a rare form of monogenic diabetes that is usually diagnosed in the first six months of life.Case presentationWe report on a male infant with neonatal diabetes who presented with diabetic ketoacidosis at two months and 16 days. A novel homozygous missense mutation (c.259T>G) was identified in the ABCC8 gene. In this case, insulin was replaced with glimepiride at a dosage of 0.49 mg/kg/day at five months, and this achieved metabolic control and satisfactory growth as observed at follow-up.ConclusionsThis report improves our understanding of the mutational spectrum of ABCC8, which is normally associated with NDM, and shows that the treatment regimen for this condition can be successfully switched from insulin therapy to the use of sulfonylurea.

scholarly journals A Zebrafish Model of Myelodysplastic Syndrome Produced throughtet2Genomic Editing

2014 ◽  
Vol 35 (5) ◽  
pp. 789-804 ◽  
Author(s):  
Evisa Gjini ◽  
Marc R. Mansour ◽  
Jeffry D. Sander ◽  
Nadine Moritz ◽  
Ashley T. Nguyen ◽  
...  
Keyword(s):  
Myelodysplastic Syndrome ◽  
Catalytic Domain ◽  
Specific Activity ◽  
Cpg Islands ◽  
Hematopoietic Cells ◽  
Cell Types ◽  
Loss Of Function ◽  
Zebrafish Model ◽  
Myeloid Progenitor ◽  
Myeloid Progenitor Cells

The ten-eleven translocation 2 gene (TET2) encodes a member of the TET family of DNA methylcytosine oxidases that converts 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) to initiate the demethylation of DNA within genomic CpG islands. Somatic loss-of-function mutations ofTET2are frequently observed in human myelodysplastic syndrome (MDS), which is a clonal malignancy characterized by dysplastic changes of developing blood cell progenitors, leading to ineffective hematopoiesis. We used genome-editing technology to disrupt the zebrafish Tet2 catalytic domain.tet2m/m(homozygous for the mutation) zebrafish exhibited normal embryonic and larval hematopoiesis but developed progressive clonal myelodysplasia as they aged, culminating in myelodysplastic syndromes (MDS) at 24 months of age, with dysplasia of myeloid progenitor cells and anemia with abnormal circulating erythrocytes. The resultanttet2m/mmutant zebrafish lines show decreased levels of 5hmC in hematopoietic cells of the kidney marrow but not in other cell types, most likely reflecting the ability of other Tet family members to provide this enzymatic activity in nonhematopoietic tissues but not in hematopoietic cells.tet2m/mzebrafish are viable and fertile, providing an ideal model to dissect altered pathways in hematopoietic cells and, for small-molecule screens in embryos, to identify compounds with specific activity againsttet2mutant cells.

Search for Pharmacoepigenetic Correlations in Type 2 Diabetes Under Sulfonylurea Treatment

2018 ◽  
Vol 127 (04) ◽  
pp. 226-233 ◽  
Author(s):  
Makrina Karaglani ◽  
Georgia Ragia ◽  
Maria Panagopoulou ◽  
Ioanna Balgkouranidou ◽  
Evangelia Nena ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Gene Promoter ◽  
Katp Channels ◽  
Protective Role ◽  
Gene Promoters ◽  
Specific Pcr ◽  
Abcc8 Gene ◽  
First Time ◽  
E23k Polymorphism

AbstractSulfonylureas are insulin secretagogues which act in pancreatic β cells by blocking the KATP channels encoded by KCNJ11 and ABCC8 genes. In the present study, a pharmacoepigenetic approach was applied for the first time, investigating the correlation of KCNJ11 and ABCC8 gene promoter methylation with sulfonylureas-induced mild hypoglycemic events as well as the KCNJ11 E23K genotype. Sodium bisulfite-treated genomic DNA of 171 sulfonylureas treated T2DM patients previously genotyped for KCNJ11 E23K, including 88 that had experienced drug-associated hypoglycemia and 83 that had never experienced hypoglycemia, were analyzed for DNA methylation of KCNJ11 and ABCC8 gene promoters via quantitative Methylation-Specific PCR. KCNJ11 methylation was detected in 19/88 (21.6%) of hypoglycemic and in 23/83 (27.7%) of non-hypoglycemic patients (p=0.353), while ABCC8 methylation in 6/83 (7.2%) of non-hypoglycemic and none (0/88) of the hypoglycemic patients (p=0.012). Methylation in at least one promoter (KCNJ11 or ABCC8) was significantly associated with non-hypoglycemic patients who are carriers of KCNJ11 EK allele (p=0.030). Our data suggest that ABCC8 but not KCNJ11 methylation is associated to hypoglycemic events in sulfonylureas-treated T2DM patients. Furthermore, it is demonstrated that the KCNJ11 E23K polymorphism in association to either of the two genes’ DNA methylation may have protective role against sulfonylurea-induced hypoglycemia.

Opposing functions of β-arrestin 1 and 2 in Parkinson’s disease via microglia inflammation and Nprl3

2020 ◽  
Author(s):  
Yinquan Fang ◽  
Qingling Jiang ◽  
Shanshan Li ◽  
Hong Zhu ◽  
Xiao Ding ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Models ◽  
Inflammatory Responses ◽  
Microglia Activation ◽  
Loss Of Function ◽  
Neuron Loss ◽  
Primary Mouse ◽  
The Impact

Abstract Background Although β-arrestins (ARRBs) regulate diverse physiological and pathophysiological processes, their function and regulation in Parkinson’s disease (PD) remain poorly defined. Methods We measured expression of ARRB1 and ARRB2 in liposaccharide (LPS)-induced and 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced PD mice. ARRB1-deficient and ARRB2-deficient mouse were used to assess the impact of ARRBs on dopaminergic (DA) neuron loss and microglia activation in PD mouse models. After primary mouse DA neurons were exposed to the conditioned medium from ARRB1 knockdown or ARRB2 knockout microglia stimulated by LPS plus interferon γ (IFN-γ), the degeneration of DA neurons was quantified. Gain- and loss-of-function studies were used to study the effects of ARRBs on microglia activation in vitro. To further understand the mechanism, we measured the activation of classical inflammatory pathways and used RNA sequencing to identify the novel downstream effector of ARRBs. Result In this study, we demonstrate that expression of ARRB1 and ARRB2, particularly in microglia, is reciprocally regulated in PD mouse models. ARRB1 ablation ameliorates, whereas ARRB2 knockout aggravates, the pathological features of PD, including DA neuron loss, neuroinflammation and microglia activation in vivo, as well as microglia-mediated neuron damage and inflammation in vitro. In parallel, ARRB1 and ARRB2 produce adverse effects on the activation of inflammatory signal transducers and activators of transcription 1 (STAT1) and nuclear factor-κB (NF-κB) pathways in microglia. We also show that two ARRBs competitively interact with activated p65 in the NF-κB pathway and that nitrogen permease regulator-like 3 (Nprl3), a functionally poorly characterized protein, is a novel effector acting downstream of both ARRBs. Conclusion Collectively, these data demonstrate that two closely related ARRBs have completely opposite functions in microglia-mediated inflammatory responses, via Nprl3, and differentially affect the pathogenesis of PD, and suggest a potential therapeutic strategy.

scholarly journals MicroRNAs in mouse models of lymphoid malignancies

2010 ◽  
Vol 1 (1) ◽  
pp. 8 ◽  
Author(s):  
Nicola A. O. Zanesi ◽  
Yuri Pekarsky ◽  
Francesco Trapasso ◽  
George Calin ◽  
Carlo M. Croce
Keyword(s):  
Gene Expression ◽  
Mouse Models ◽  
Gene Expression Regulation ◽  
Human Leukemia ◽  
Down Regulation ◽  
Over Expression ◽  
Lymphoid Malignancies ◽  
Knockout Animals ◽  
Mouse Modeling

<!--StartFragment--> <p class="MsoBodyText"><span style="mso-tab-count: 1;"> </span>The discovery of microRNAs (miRNAs) has revealed a new layer of gene expression regulation that affects many normal and pathologic biological systems. Among the malignancies affected by the dysregulation of miRNAs there are cancers of lymphoid origin, in which miRNAs are thought to have tumor suppressive or tumor promoting activities, depending on the nature of their specific targets. In the last 4-5 years, the experimental field that provided the deepest insights into the <em>in vivo</em><span style="font-style: normal;"> biology of miRNAs is that of mouse modeling in which transgenic and knockout animals mimic, respectively, over-expression or down-regulation of specific miRNAs involved in human leukemia/lymphoma. This review discusses recent advances in our understanding of lymphoid malignancies based on the natural and engineered mouse models of three different miRNAs, miR-15a/16-1 cluster, miR-155, and miR-17-92 cluster.</span></p> <!--EndFragment-->

scholarly journals Phages as immunomodulators and their promising use as anti-inflammatory agents in a cftr loss-of-function zebrafish model

2020 ◽  
Author(s):  
Marco Cafora ◽  
Alessia Brix ◽  
Francesca Forti ◽  
Nicoletta Loberto ◽  
Massimo Aureli ◽  
...  
Keyword(s):  
Loss Of Function ◽  
Zebrafish Model ◽  
Anti Inflammatory

Gene of the month: GLIS1-3

2020 ◽  
Vol 73 (9) ◽  
pp. 527-530
Author(s):  
Karen Pinto ◽  
Runjan Chetty
Keyword(s):  
Autosomal Recessive ◽  
Interstitial Fibrosis ◽  
Neonatal Diabetes ◽  
Diagnostic Value ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Facial Dysmorphism ◽  
Loss Of Function ◽  
Tubular Atrophy ◽  
Colon Cancers

The GLIS 1–3 genes belong to a family of transcription factors, the Krüppel-like zinc finger proteins. The GLIS proteins function primarily as activators of transcription (GLIS 1 and 3), while GLIS 2 functions as a repressor. Collectively, the GLIS proteins are involved in a variety of diseases in several organs ranging from Alzheimer’s disease, facial dysmorphism, neonatal diabetes mellitus, breast and colon cancers and leukaemia. In particular, loss-of-function mutations in GLIS2 are responsible for an autosomal recessive cystic kidney disease called nephronophthisis, which is characterised by tubular atrophy, interstitial fibrosis and corticomedullary cysts.Of diagnostic value in current practice are the presence of GLIS 3 and 1 fusions with PAX8 in almost 100% of hyalinising trabecular tumours of the thyroid gland. This enables its separation from papillary thyroid cancer.

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