scholarly journals Therapeutic manipulation of IKBKAP mis-splicing with a small molecule to cure familial dysautonomia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Masahiko Ajiro ◽  
Tomonari Awaya ◽  
Young Jin Kim ◽  
Kei Iida ◽  
Masatsugu Denawa ◽  
...  
Keyword(s):  
Small Molecule ◽  
Genetic Disease ◽  
Therapeutic Strategy ◽  
Therapeutic Potential ◽  
Familial Dysautonomia ◽  
Therapeutic Modality ◽  
Aberrant Splicing ◽  
Intronic Splicing Enhancer ◽  
Exon 20 ◽  
Splicing Enhancer

AbstractApproximately half of genetic disease-associated mutations cause aberrant splicing. However, a widely applicable therapeutic strategy to splicing diseases is yet to be developed. Here, we analyze the mechanism whereby IKBKAP-familial dysautonomia (FD) exon 20 inclusion is specifically promoted by a small molecule splice modulator, RECTAS, even though IKBKAP-FD exon 20 has a suboptimal 5′ splice site due to the IVS20 + 6 T > C mutation. Knockdown experiments reveal that exon 20 inclusion is suppressed in the absence of serine/arginine-rich splicing factor 6 (SRSF6) binding to an intronic splicing enhancer in intron 20. We show that RECTAS directly interacts with CDC-like kinases (CLKs) and enhances SRSF6 phosphorylation. Consistently, exon 20 splicing is bidirectionally manipulated by targeting cellular CLK activity with RECTAS versus CLK inhibitors. The therapeutic potential of RECTAS is validated in multiple FD disease models. Our study indicates that small synthetic molecules affecting phosphorylation state of SRSFs is available as a new therapeutic modality for mechanism-oriented precision medicine of splicing diseases.

scholarly journals Rectifier of aberrant mRNA splicing recovers tRNA modification in familial dysautonomia

2015 ◽  
Vol 112 (9) ◽  
pp. 2764-2769 ◽  
Author(s):  
Mayumi Yoshida ◽  
Naoyuki Kataoka ◽  
Kenjyo Miyauchi ◽  
Kenji Ohe ◽  
Kei Iida ◽  
...  
Keyword(s):  
Familial Dysautonomia ◽  
Drug Candidate ◽  
Therapeutic Drug ◽  
Aberrant Splicing ◽  
Gene Encoding ◽  
Trna Modifications ◽  
Intronic Mutation ◽  
Gene Enhancer ◽  
Exon 20 ◽  
In Cells

Familial dysautonomia (FD), a hereditary sensory and autonomic neuropathy, is caused by missplicing of exon 20, resulting from an intronic mutation in the inhibitor of kappa light polypeptide gene enhancer in B cells, kinase complex-associated protein (IKBKAP) gene encoding IKK complex-associated protein (IKAP)/elongator protein 1 (ELP1). A newly established splicing reporter assay allowed us to visualize pathogenic splicing in cells and to screen small chemicals for the ability to correct the aberrant splicing of IKBKAP. Using this splicing reporter, we screened our chemical libraries and identified a compound, rectifier of aberrant splicing (RECTAS), that rectifies the aberrant IKBKAP splicing in cells from patients with FD. Here, we found that the levels of modified uridine at the wobble position in cytoplasmic tRNAs are reduced in cells from patients with FD and that treatment with RECTAS increases the expression of IKAP and recovers the tRNA modifications. These findings suggest that the missplicing of IKBKAP results in reduced tRNA modifications in patients with FD and that RECTAS is a promising therapeutic drug candidate for FD.

scholarly journals An Alu-derived intronic splicing enhancer facilitates intronic processing and modulates aberrant splicing in ATM

2009 ◽  
Vol 37 (21) ◽  
pp. 7258-7267 ◽  
Author(s):  
Tibor Pastor ◽  
Gabriele Talotti ◽  
Marzena Anna Lewandowska ◽  
Franco Pagani
Keyword(s):  
Aberrant Splicing ◽  
Intronic Splicing Enhancer ◽  
Splicing Enhancer

scholarly journals An autophagy enhancer ameliorates diabetes of human IAPP-transgenic mice through clearance of amyloidogenic oligomer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jinyoung Kim ◽  
Kihyoun Park ◽  
Min Jung Kim ◽  
Hyejin Lim ◽  
Kook Hwan Kim ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Function ◽  
Therapeutic Potential ◽  
Therapeutic Modality ◽  
Protective Effects ◽  
Β Cells ◽  
Β Cell ◽  
Islet Amyloid ◽  
Amyloid Accumulation ◽  
Human Diabetes

AbstractWe have reported that autophagy is crucial for clearance of amyloidogenic human IAPP (hIAPP) oligomer, suggesting that an autophagy enhancer could be a therapeutic modality against human diabetes with amyloid accumulation. Here, we show that a recently identified autophagy enhancer (MSL-7) reduces hIAPP oligomer accumulation in human induced pluripotent stem cell-derived β-cells (hiPSC-β-cells) and diminishes oligomer-mediated apoptosis of β-cells. Protective effects of MSL-7 against hIAPP oligomer accumulation and hIAPP oligomer-mediated β-cell death are significantly reduced in cells with knockout of MiTF/TFE family members such as Tfeb or Tfe3. MSL-7 improves glucose tolerance and β-cell function of hIAPP+ mice on high-fat diet, accompanied by reduced hIAPP oligomer/amyloid accumulation and β-cell apoptosis. Protective effects of MSL-7 against hIAPP oligomer-mediated β-cell death and the development of diabetes are also significantly reduced by β-cell-specific knockout of Tfeb. These results suggest that an autophagy enhancer could have therapeutic potential against human diabetes characterized by islet amyloid accumulation.

scholarly journals Gene Editing and Modulation: the Holy Grail for the Genetic Epilepsies?

2021 ◽  
Author(s):  
Jenna C. Carpenter ◽  
Gabriele Lignani
Keyword(s):  
Precision Medicine ◽  
Neurological Disorder ◽  
Gene Editing ◽  
Therapeutic Strategy ◽  
Therapeutic Potential ◽  
Single Gene ◽  
Drug Resistant ◽  
Holy Grail ◽  
Effective Therapeutic Strategy ◽  
Genetic Epilepsies

AbstractEpilepsy is a complex neurological disorder for which there are a large number of monogenic subtypes. Monogenic epilepsies are often severe and disabling, featuring drug-resistant seizures and significant developmental comorbidities. These disorders are potentially amenable to a precision medicine approach, of which genome editing using CRISPR/Cas represents the holy grail. Here we consider mutations in some of the most ‘common’ rare epilepsy genes and discuss the different CRISPR/Cas approaches that could be taken to cure these disorders. We consider scenarios where CRISPR-mediated gene modulation could serve as an effective therapeutic strategy and discuss whether a single gene corrective approach could hold therapeutic potential in the context of homeostatic compensation in the developing, highly dynamic brain. Despite an incomplete understanding of the mechanisms of the genetic epilepsies and current limitations of gene editing tools, CRISPR-mediated approaches have game-changing potential in the treatment of genetic epilepsy over the next decade.

scholarly journals Metformin and Niclosamide Synergistically Suppress Wnt and YAP in APC-Mutated Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3437
Author(s):  
Hee Eun Kang ◽  
Yoojeong Seo ◽  
Jun Seop Yun ◽  
Sang Hyun Song ◽  
Dawool Han ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Progression ◽  
Therapeutic Strategy ◽  
Target Gene ◽  
Advanced Colorectal Cancer ◽  
Therapeutic Potential ◽  
Cancer Stemness ◽  
Reciprocal Regulation ◽  
Canonical Wnt

The Wnt and Hippo pathways are tightly coordinated and understanding their reciprocal regulation may provide a novel therapeutic strategy for cancer. Anti-helminthic niclosamide is an effective inhibitor of Wnt and is now in a phase II trial for advanced colorectal cancer (CRC) patients. We found that Axin2, an authentic target gene of canonical Wnt, acts as aYAP phosphorylation activator in APC-mutated CRC. While niclosamide effectively suppresses Wnt, it also inhibits Hippo, limiting its therapeutic potential for CRC. To overcome this limitation, we utilized metformin, a clinically available AMPK activator. This combinatory approach not only suppresses canonical Wnt activity, but also inhibits YAP activity in CRC cancer cells and in patient-derived cancer organoid through the suppression of cancer stemness. Further, combinatory oral administration suppressed in vivo tumorigenesis and the cancer progression of APC-MIN mice models. Our observations provide not only a reciprocal link between Wnt and Hippo, but also clinically available novel therapeutics that are able to target Wnt and YAP in APC-mutated CRC.

scholarly journals Hypophosphatasia: A Unique Disorder of Bone Mineralization

2021 ◽  
Vol 22 (9) ◽  
pp. 4303
Author(s):  
Juan Miguel Villa-Suárez ◽  
Cristina García-Fontana ◽  
Francisco Andújar-Vera ◽  
Sheila González-Salvatierra ◽  
Tomás de Haro-Muñoz ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Genetic Disease ◽  
Therapeutic Strategy ◽  
Pediatric Patients ◽  
Bone Mineralization ◽  
Clinical Manifestations ◽  
Allelic Heterogeneity ◽  
Specific Enzyme ◽  
Inorganic Pyrophosphate ◽  
Enzyme Replacement

Hypophosphatasia (HPP) is a rare genetic disease characterized by a decrease in the activity of tissue non-specific alkaline phosphatase (TNSALP). TNSALP is encoded by the ALPL gene, which is abundantly expressed in the skeleton, liver, kidney, and developing teeth. HPP exhibits high clinical variability largely due to the high allelic heterogeneity of the ALPL gene. HPP is characterized by multisystemic complications, although the most common clinical manifestations are those that occur in the skeleton, muscles, and teeth. These complications are mainly due to the accumulation of inorganic pyrophosphate (PPi) and pyridoxal-5′-phosphate (PLP). It has been observed that the prevalence of mild forms of the disease is more than 40 times the prevalence of severe forms. Patients with HPP present at least one mutation in the ALPL gene. However, it is known that there are other causes that lead to decreased alkaline phosphatase (ALP) levels without mutations in the ALPL gene. Although the phenotype can be correlated with the genotype in HPP, the prediction of the phenotype from the genotype cannot be made with complete certainty. The availability of a specific enzyme replacement therapy for HPP undoubtedly represents an advance in therapeutic strategy, especially in severe forms of the disease in pediatric patients.

scholarly journals Regulation of RNA Splicing: Aberrant Splicing Regulation and Therapeutic Targets in Cancer

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 923
Author(s):  
Koji Kitamura ◽  
Keisuke Nimura
Keyword(s):  
Dna Sequences ◽  
Rna Splicing ◽  
Splicing Factors ◽  
Splicing Regulation ◽  
Aberrant Splicing ◽  
Aberrant Expression ◽  
Non Coding Rnas ◽  
Precursor Mrna ◽  
Splicing Enhancer ◽  
Small Nuclear Ribonucleoproteins

RNA splicing is a critical step in the maturation of precursor mRNA (pre-mRNA) by removing introns and exons. The combination of inclusion and exclusion of introns and exons in pre-mRNA can generate vast diversity in mature mRNA from a limited number of genes. Cancer cells acquire cancer-specific mechanisms through aberrant splicing regulation to acquire resistance to treatment and to promote malignancy. Splicing regulation involves many factors, such as proteins, non-coding RNAs, and DNA sequences at many steps. Thus, the dysregulation of splicing is caused by many factors, including mutations in RNA splicing factors, aberrant expression levels of RNA splicing factors, small nuclear ribonucleoproteins biogenesis, mutations in snRNA, or genomic sequences that are involved in the regulation of splicing, such as 5’ and 3’ splice sites, branch point site, splicing enhancer/silencer, and changes in the chromatin status that affect the splicing profile. This review focuses on the dysregulation of RNA splicing related to cancer and the associated therapeutic methods.

scholarly journals Nova Regulates GABAA Receptor γ2 Alternative Splicing via a Distal Downstream UCAU-Rich Intronic Splicing Enhancer

2003 ◽  
Vol 23 (13) ◽  
pp. 4687-4700 ◽  
Author(s):  
B. Kate Dredge ◽  
Robert B. Darnell
Keyword(s):  
Alternative Splicing ◽  
Rna Binding ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Splicing Regulation ◽  
Globin Genes ◽  
Enhancer Element ◽  
Intronic Splicing Enhancer ◽  
Splicing Enhancer

ABSTRACT Nova is a neuron-specific RNA binding protein targeted in patients with the autoimmune disorder paraneoplastic opsoclonus-myoclonus ataxia, which is characterized by failure of inhibition of brainstem and spinal motor systems. Here, we have biochemically confirmed the observation that splicing regulation of the inhibitory GABAA receptor γ2 (GABAARγ2) subunit pre-mRNA exon E9 is disrupted in mice lacking Nova-1. To elucidate the mechanism by which Nova-1 regulates GABAARγ2 alternative splicing, we systematically screened minigenes derived from the GABAARγ2 and human β-globin genes for their ability to support Nova-dependent splicing in transient transfection assays. These studies demonstrate that Nova-1 acts directly on GABAARγ2 pre-mRNA to regulate E9 splicing and identify an intronic region that is necessary and sufficient for Nova-dependent enhancement of exon inclusion, which we term the NISE (Nova-dependent intronic splicing enhancer) element. The NISE element (located 80 nucleotides upstream of the splice acceptor site of the downstream exon E10) is composed of repeats of the sequence YCAY, consistent with previous studies of the mechanism by which Nova binds RNA. Mutation of these repeats abolishes binding of Nova-1 to the RNA in vitro and Nova-dependent splicing regulation in vivo. These data provide a molecular basis for understanding Nova regulation of GABAARγ2 alternative splicing and suggest that general dysregulation of Nova's splicing enhancer function may underlie the neurologic defects seen in Nova's absence.

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