| 1. |
- Umek, Tea, et al.
(författare)
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Oligonucleotide Binding to Non-B-DNA in MYC
- 2019
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Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 24:5
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Tidskriftsartikel (refereegranskat)abstract
- MYC, originally named c-myc, is an oncogene deregulated in many different forms of cancer. Translocation of the MYC gene to an immunoglobulin gene leads to an overexpression and the development of Burkitt's lymphoma (BL). Sporadic BL constitutes one subgroup where one of the translocation sites is located at the 5'-vicinity of the two major MYC promoters P-1 and P-2. A non-B-DNA forming sequence within this region has been reported with the ability to form an intramolecular triplex (H-DNA) or a G-quadruplex. We have examined triplex formation at this site first by using a 17 bp triplex-forming oligonucleotide (TFO) and a double strand DNA (dsDNA) target corresponding to the MYC sequence. An antiparallel purine-motif triplex was detected using electrophoretic mobility shift assay. Furthermore, we probed for H-DNA formation using the BQQ-OP based triplex-specific cleavage assay, which indicated the formation of the structure in the supercoiled plasmid containing the corresponding region of the MYC promoter. Targeting non-B-DNA structures has therapeutic potential; therefore, we investigated their influence on strand-invasion of anti-gene oligonucleotides (ON)s. We show that in vitro, non-B-DNA formation at the vicinity of the ON target site facilitates dsDNA strand-invasion of the anti-gene ONs.
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| 2. |
- Lundin, Karin E., et al.
(författare)
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Eleven percent intact PGM3 in a severely immunodeficient patient with a novel splice-site mutation, a case report
- 2018
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Ingår i: BMC Pediatrics. - : Springer. - 1471-2431 .- 1471-2431. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: A novel immunodeficiency, frequently accompanied by high serum-IgE, and caused by mutations in the PGM3 gene was described in 2014. To date there are no unique phenotype characteristics for PGM3 deficiency. PGM3 encodes a carbohydrate-modifying enzyme, phosphoglucomutase 3. Null-mutations are quite likely lethal, and to date only missense mutations or small deletions have been reported. Such mutations frequently cause a combination of reduced enzyme activity and protein instability, complicating determination of the enzyme level needed for survival. Here we present the first patient with a homozygous splice-modifying mutation in the PGM3 gene. An A > G substitution at position c.871 +3 (transcript NM_001199917) is causing a deletion of exon 7 in the majority of PGM3 transcripts. In addition, this case further increases the clinical phenotypes of immunodeficiency caused by PGM3 mutations. Case presentation: We describe the symptoms of a 3-year-old girl who was severely growth retarded, had vascular malformations, extensive eczema, multiple food-allergies, and was prone to infections. Unlike the majority of reported PGM3 deficient patients she lacked skeletal dysplasia and had normal neurocognitive development. In addition to the high serum-IgE, she displayed altered T cell numbers with reduced naive CD4(+) and CD8(+) T-cells, increased number of activated effector memory CD8(+) T cells and aberrant T-cell functions. The patient was homozygous for a new hypomorphic, splice-modifying mutation in the PGM3 gene, causing severely reduced mRNA levels. In the patient's cells, we observed 5% intact mRNA and approximately 11% of the protein levels seen in healthy controls. Treatment with allogeneic hematopoietic stem cell therapy was planned, but unfortunately the clinical condition deteriorated with multi-organ failure, which led to her death at 3 years of age. Conclusions: There is still no specific phenotype identified that distinguishes immunodeficiency caused by PGM3 mutations from other forms of immunodeficiency. The patient described here yields new information on the phenotypic variability among these patients. In addition, since all the synthesized protein is wild-type, it is possible for the first time to estimate the enzyme activity in vivo. The results suggest that1/10 of the normal PGM3 level is sufficient for survival but that it is insufficient for accurate carbohydrate processing.
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| 3. |
- Lundin, Karin, 1977-, et al.
(författare)
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Re-implantation of an auditory brainstem implant (ABI) in a child : A case report
- 2017
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Ingår i: Acta oto-laryngologica case reports. - : Taylor & Francis Group. - 2377-2484. ; 2:1, s. 119-124
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Tidskriftsartikel (refereegranskat)abstract
- The study aimed at describing a case of auditory brainstem implant (ABI) paediatric re-implantation performed at the Akademiska University Hospital, Sweden. The patient was a boy with Goldenhar syndrome with absent vestibular-cochlear nerves and was first implanted with an ABI in 2009 at the age of two years. A technical device failure in 2015 led to a re-implantation at the age of nine years. The ABI was successfully re-implanted although the implant was closely attached to the surrounding tissue and difficult to remove. The intraoperative electrical auditory brainstem measures (eABRs) gave unclear responses after re-implantation. After 12 months, the patient's hearing thresholds was not as good as it was after the primary implant, but it is still developing. The child is a full-time user. ABI re-implantation is possible even after many years, although there is a risk that the implant might be fixed to the brainstem and difficult to remove.
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| 4. |
- Zaghloul, Eman M., et al.
(författare)
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CTG repeat-targeting oligonucleotides for down-regulating Huntingtin expression
- 2017
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Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 45:9, s. 5153-5169
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Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is a fatal, neurodegenerative disorder in which patients suffer from mobility, psychological and cognitive impairments. Existing therapeutics are only symptomatic and do not significantly alter the disease progression or increase life expectancy. HD is caused by expansion of the CAG trinucleotide repeat region in exon 1 of the Huntingtin gene (HTT), leading to the formation of mutant HTT transcripts (muHTT). The toxic gain-of-function of muHTT protein is a major cause of the disease. In addition, it has been suggested that the muHTT transcript contributes to the toxicity. Thus, reduction of both muHTT mRNA and protein levels would ideally be the most useful therapeutic option. We herein present a novel strategy for HD treatment using oligonucleotides (ONs) directly targeting the HTT trinucleotide repeat DNA. A partial, but significant and potentially long-term, HTT knock-down of both mRNA and protein was successfully achieved. Diminished phosphorylation of HTT gene-associated RNA-polymerase II is demonstrated, suggestive of reduced transcription downstream the ON-targeted repeat. Different backbone chemistries were found to have a strong impact on the ON efficiency. We also successfully use different delivery vehicles as well as naked uptake of the ONs, demonstrating versatility and possibly providing insights for in vivo applications.
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| 5. |
- Geny, Sylvain, et al.
(författare)
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Next-generation bis-locked nucleic acids with stacking linker and 2 '-glycylamino-LNA show enhanced DNA invasion into supercoiled duplexes
- 2016
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Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 44:5, s. 2007-2019
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Tidskriftsartikel (refereegranskat)abstract
- Targeting and invading double-stranded DNA with synthetic oligonucleotides under physiological conditions remain a challenge. Bis-locked nucleic acids (bisLNAs) are clamp-forming oligonucleotides able to invade into supercoiled DNA via combined Hoogsteen and Watson-Crick binding. To improve the bisLNA design, we investigated its mechanism of binding. Our results suggest that bisLNAs bind via Hoogsteen-arm first, followed by Watson-Crick arm invasion, initiated at the tail. Based on this proposed hybridization mechanism, we designed next-generation bisLNAs with a novel linker able to stack to adjacent nucleobases, a new strategy previously not applied for any type of clamp-constructs. Although the Hoogsteen-arm limits the invasion, upon incorporation of the stacking linker, bisLNA invasion is significantly more efficient than for non-clamp, or nucleotide-linker containing LNA-constructs. Further improvements were obtained by substituting LNA with 2'-glycylamino-LNA, contributing a positive charge. For regular bisLNAs a 14-nt tail significantly enhances invasion. However, when two stacking linkers were incorporated, tail-less bisLNAs were able to efficiently invade. Finally, successful targeting of plasmids inside bacteria clearly demonstrates that strand invasion can take place in a biologically relevant context.
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| 6. |
- Lundin, Karin, et al.
(författare)
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Experiences from Auditory Brainstem Implantation (ABI) in four Paediatric Patients
- 2016
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Ingår i: Cochlear Implants International. - : Taylor & Francis. - 1467-0100 .- 1754-7628. ; 17:2, s. 109-115
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Indications for auditory brainstem implants (ABIs) have been widened from patients with neurofibromatosis type 2 (NF2) to paediatric patients with congenital cochlear malformations, cochlear nerve hypoplasia/aplasia, or cochlear ossification after meningitis. We present four ABI surgeries performed in children at Uppsala University Hospital in Sweden since 2009.Methods: Three children were implanted with implants from Cochlear Ltd. (Lane Cove, Australia) and one child with an implant from MedEl GMBH (Innsbruck, Austria). A boy with Goldenhar syndrome was implanted with a Cochlear Nucleus ABI24M at age 2 years (patient 1). Another boy with CHARGE syndrome was implanted with a Cochlear Nucleus ABI541 at age 2.5 years (patient 2). Another boy with post-ossification meningitis was implanted with a Cochlear Nucleus ABI24M at age 4 years (patient 3). A girl with cochlear aplasia was implanted with a MedEl Synchrony ABI at age 3 years (patient 4). In patients 1, 2, and 3, the trans-labyrinthine approach was used, and in patient 4 the retro-sigmoid approach was used.Results: Three of the four children benefited from their ABIs and use it full time. Two of the full time users had categories of auditory performance (CAP) score of 4 at their last follow up visit (6 and 2.5 years postoperative) which means they can discriminate consistently any combination of two of Ling's sounds. One child has not been fully evaluated yet, but is a full time user and had CAP 2 (responds to speech sounds) after 3 months of ABI use. No severe side or unpleasant stimulation effects have been observed so far. There was one case of immediate electrode migration and one case of implant device failure after 6.5 years.Conclusion: ABI should be considered as an option in the rehabilitation of children with similar diagnoses.
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| 7. |
- Lundin, Karin, 1977-
(författare)
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Experiences from Cochlear Implantation and Auditory Brainstem Implantation in Adults and Children : Electrophysiological Measurements, Hearing Outcomes and Patient Satisfaction
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cochlear implants (CIs) and auditory brainstem implants (ABIs) are prostheses for hearing used in patients with profound hearing impairment. A CI requires an operational cochlear nerve to function in contrast to an ABI. ABIs were initially designed for adult patients with neurofibromatosis type 2 (NF2), suffering from bilateral vestibular schwannomas. Now ABIs are also used for patients, both adults and children, with congenital cochlear malformations, cochlear nerve hypoplasia/aplasia, and cochlear ossification. The aims of this thesis are to evaluate hearing outcome in patients implanted with a CI after long-term deafness. An extended period of deafness has earlier been considered as a contraindication for CI surgery. Further, we analyzed if electrically evoked auditory brainstem responses (eABRs) can predict CI outcome and pinpoint the optimal selection of treatment such as CI or ABI. We also disclose our experiences from ABI surgery in Uppsala, such as implant use, hearing outcome, complications, and satisfaction among the patients. Finally, we evaluated the results and benefits of ABIs in non-NF2 pediatric patients.Results show that patients with an extended deafness period and durations over 20 years can achieve speech understanding and benefit from CIs. Patients with long-term deafness and limited years of hearing before deafness did not perform as well as those with shorter deafness duration and longer hearing experience did. eABR seems to have a definite role in the diagnostic armamentarium, to better consider alternative surgical strategies such as ABI. No eABR waveform predicted a poor CI outcome. There was no correlation between speech perception and eABR waveform latencies or eABR waveform quality. A majority of the ABI patients used their ABIs and benefited from them for at least some period. ABI assisted voice control in a majority of the full-time users and they reported improved understanding of speech with the implant switched on. No severe complications from ABI surgery or ABI stimulation were noted. The patients were generally satisfied, even if their hearing remained very limited. All pediatric patients but one used the implant continuously and benefited from it.
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| 8. |
- Lundin, Karin, et al.
(författare)
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Self-Reported Benefit, Sound Perception, and Quality-of-Life in Patients with Auditory Brainstem Implants (ABIs)
- 2016
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 136:1, s. 62-67
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Tidskriftsartikel (refereegranskat)abstract
- CONCLUSION:The majority of the patients used their auditory brainstem implants (ABIs) all the time, reporting that he/she would make the decision to receive an implant again if the decision were reconsidered. The findings support that the ABI is a valuable treatment in patients with type 2 neurofibromatosis (NF2) and in children with congenital inner ear and nerve anomalies or cochlear ossification.OBJECTIVE:To evaluate the patients who underwent ABI implantation in Uppsala during 1993-2013. This study analyzed patients' implant use, perception of environmental sounds, perceived benefit from the implant, and quality-of-life (QoL).METHOD:The NF2-patients (n = 20) comprised the majority of the patients, and there were a few non-NF2 pediatric patients (n = 4). The exclusion criteria included deceased patients (n = 4) and patients with no hearing sensations from the implant, or those with an inactivated ABI (n = 2). The data were collected from a questionnaire survey.RESULTS:Eleven adult patients and two pediatric patients answered the questionnaires. Eight of the adult patients used their implants 'always'. The two children always used their implants. Hearing problems had the largest negative effect on the QoL. The non-users and the users scored equally on the NFTI-QoL.
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| 9. |
- Lundin, Karin E, et al.
(författare)
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Susceptibility to infections, without concomitant hyper-IgE, reported in 1976, is caused by hypomorphic mutation in the phosphoglucomutase 3 (PGM3) gene
- 2015
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Ingår i: Clinical Immunology. - : Elsevier. - 1521-6616 .- 1521-7035. ; 161:2, s. 366-372
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Tidskriftsartikel (refereegranskat)abstract
- Phosphoglucomutase 3 (PGM3) is an enzyme converting N-acetyl-glucosamine-6-phosphate to N-acetylglucosamine-l-phosphate, a precursor important for glycosylation. Mutations in the PGM3 gene have recently been identified as the cause of novel primary immunodeficiency with a hyper-IgE like syndrome. Here we report the occurrence of a homozygous mutation in the PGM3 gene in a family with immunodeficient children, described already in 1976. DNA from two of the immunodeficient siblings was sequenced and shown to encode the same homozygous missense mutation, causing a destabilized protein with reduced enzymatic capacity. Affected individuals were highly prone to infections, but lack the developmental defects in the nervous and skeletal systems, reported in other families. Moreover, normal IgE levels were found. Thus, belonging to the expanding group of congenital glycosylation defects, PGM3 deficiency is characterized by immunodeficiency, with or without increased IgE levels, and with variable forms of developmental defects affecting other organ systems.
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| 10. |
- Lundin, Karin, et al.
(författare)
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Prognostic Value of Electrically Evoked Auditory Brainstem Responses in Cochlear Implantation
- 2015
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Ingår i: Cochlear Implants International. - 1467-0100 .- 1754-7628. ; 16:5, s. 254-261
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesThe aim of this study was to investigate whether electrical auditory brainstem responses (eABRs) obtained during cochlear implantation (CI) can predict CI outcomes. We also aimed to assess whether eABR can be used to select patients for auditory brainstem implantation (ABI).MethodsThis was a retrospective study. The latencies and quality of the eABR waveforms from adult patients implanted with CI in Uppsala from 2011 to 2013 (n = 74) and four children with severe cochlear abnormalities were analyzed. Speech perception was assessed through postoperative monosyllabic word (MS-word) recognition. A score was constructed for each patient based on wave II, III, and V patency.ResultseABR latencies increased towards base stimulation of the cochlea. Wave V for the mid- and low-frequency regions was the most robust. Significant latency shifts occurred in wave V from the low- to high-frequency regions (**P < 0.01) and from the mid- to high-frequency regions (**P < 0.01). No correlations were found between waveform score, wave V–III interval, wave V latency, and MS-word scores. A negative eABR always predicted a negative outcome. Among the patients with negative outcomes, 75% had eABRs.DiscussionImplant electrical stimulation and brain stem recordings can be used (eABRs wave V) to predict a negative functional outcome. Low-frequency waves V were observed in all patients with successful CI outcomes. Patients for whom eABR waveforms were completely absent had unsuccessful CI outcomes.
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