Spinal muscular atrophy (SMA) is a progressive neuromuscular disease, associated with motoneuron loss and muscle wasting. Numerous SMA-causative mutations have been reported in survival motor neuron (

) gene(s); however, the pathogenic mechanism underlying SMA remains unclear. In the present study, we showed that modulates the expression of transcription factor EB (TFEB), a master regulator of lysosomal genes that plays a key role in lysosome function, autophagy, and the mammalian target of rapamycin (mTOR) signaling pathway. The transfection of small interfering RNA (siRNA) targeting caused a reduction in TFEB expression in the motoneuron-like NSC-34 cell line. In differentiated NSC-34 cells, either or TFEB knockdown resulted in reduced lysosomes at neurites and the atypical accumulation of swollen and enlarged lysosomes in cell bodies. knockdown caused the reduced expression of lysosome-related genes, resulting in the decline of lysosomal degradation and increased autophagic flux. These -depletion-induced aberrations in lysosomes and autophagy could be rescued by the exogenous expression of TFEB. Furthermore, depletion in NSC-34 cells resulted in the decreased phosphorylation of mTOR and its downstream signals. Finally, SMA transgenic mice exhibited reduced TFEB and lysosomal protein expression and the inactivation of mTOR signaling in the lumbar spinal cord at postnatal day 11, compared with their counterparts. These findings indicated that regulates lysosomal gene expression and functions by altering TFEB expression in motoneurons. The targeting of lysosomes might represent a new strategy for the treatment of SMA.

抄録全体を表示

脊髄性筋萎縮症(spinal muscular atrophy: SMA)は，四肢，体幹および呼吸筋の高度な脱力を引き起こす遺伝性の神経筋疾患で我が国では指定難病に定められている．
SMAは，Survival Motor Neuron 1(以下遺伝子の両対立遺伝子の機能喪失変異による常染色体劣性（潜性)遺伝疾患である．ヒトの遺伝子には機能性タンパク質が産生される遺伝子と，産生されるタンパク質の約90％が不完全長で分解されやすい遺伝子がある．
本剤は， pre-mRNAに作用し，完全長の mRNAへのスプライシングを促進する．経口投与により全身に分布し，中枢神経系および全身の機能性タンパク質を増加させることが期待される．
我が国では，2つの国際共同第Ⅱ/Ⅲ相試験の成績から，「脊髄性筋萎縮症」治療剤として，2021年6月に製造販売承認を取得した．

抄録全体を表示

脊髄性筋萎縮症 (SMA) は5MN 1遺伝子欠失を原因とする常染色体劣性遺伝疾患である. 2は 1と5塩基のみ異なる遺伝子でSMA重症度に影響すると考えられている. SMAは重症度によって3型に区別されている. 私たちはSMA 22例 (Type I 17例, Type II 3例, TypeIII 2例) においてリアルタイムPCRによる 2遺伝子の定量を行い, 臨床症状との相関を検討した. Type I患者は 2遺伝子がそれぞれ1, 2および3コピーと考えられる群に分れ, コピー数1の3例では新生児期より発症し進行が早くType Iの中でも最重症例であった. 残りの14例ではコピー数2または3で様々な臨床像を示した. コピー数3であっても生後2カ月で人工呼吸管理を要したType I症例があった. Type II, III患者5名はコピー数が4以上であった. 2遺伝子は重症度に関与しているが, Type Iの中には 2の代償機序の今後の検討が必要とされる症例があった.

抄録全体を表示

 脊髄性筋萎縮症 (spinal muscular atrophy ; SMA) は, 脊髄前角細胞の変性, 脱落に伴う全身の筋力低下を生じる常染色体劣性神経筋疾患である. 責任遺伝子は

遺伝子であり, SMA 1型の95%は遺伝子欠失のホモ接合体である. 今回我々は, 片側の遺伝子が欠失し, もう一方の遺伝子内に変異を認めるSMA症例を経験した. 本症例は日本人男児で, 新生児期から全身の筋力低下と呼吸障害を認め, 生後20日で非侵襲的陽圧換気を受けることになった. 患者の呼吸障害は急速に進行し, 生後3カ月で気管挿管下陽圧換気に移行し, 生後6カ月で気管切開下陽圧換気に至った. MLPA法を用いて遺伝子欠失を確認したところ, 遺伝子は1コピー存在することを確認した. その後遺伝子の各塩基配列を検索したところ, エクソン6にc.819_820insTの微小変異を認め, 遺伝子欠失と変異型遺伝子の複合ヘテロ接合体であることが明らかとなった. 臨床症状と遺伝子検査結果を踏まえ, 患者はSMA 1型と診断された. この変異は蛋白のC末端の構造変化や機能異常をもたらすことが推測される. 本症例では, 遺伝子内変異がSMAの原因となり, 重症度を規定している因子でもあることを示唆している.

抄録全体を表示

Background : A second malignant neoplasm () has the greatest impact on the prognosis of childhood cancer survivors (CCSs). Although germline abnormalities in cancer predisposition genes have been reported as a cause of in CCSs, the genetic background is not considered for surveillance in the follow-up guidelines. This study aimed to present an surveillance system for CCSs using germline cancer predisposition genes and evaluate their efficacy. We also aimed to elucidate the psychological impact of a surveillance system on CCSs and their guardians.
Methods : CCSs who visited the long-term follow-up clinic at Shinshu University Hospital were recruited. They underwent next-generation sequencing-based germline genetic investigation using a custom panel including 165 cancer predisposition genes and a multiplex ligation-dependent probe amplification method for TP53. Based on the molecular findings, appropriate surveillance was proposed. A questionnaire-based survey was conducted to comprehend the thoughts of CCSs and/or their guardians regarding , clinical sequencing, and surveillance.
Results : As of March 2021, 16 CCSs, mostly with leukemia as a primary cancer, participated in this study. No pathogenic or likely pathogenic variants were detected in any of the participants. Variants of uncertain significance were found in four CCSs showing increased anxiety.
Conclusions : This study could not show the efficacy of an surveillance system for CCSs, because no pathogenic or likely pathogenic variants were detected. Further evaluation, including more CCSs with a wider spectrum of cancers, would be necessary to evaluate this system. Genetic counseling might require careful anticipatory guidance for clinical sequencing and follow-up services.

抄録全体を表示

Spinal muscular atrophy (SMA) is the second most frequent autosomal recessive disease characterized by degeneration of the anterior horn cells of the spinal cord, leading to muscular atrophy. SMA is classified into three types according to disease severity and age-onset: severe (type I), intermediate (type II) and mild (type III). Deletions in the survival motor neuron () gene, located in the chromosome region 5q11.2- 5q13.3, are major determinants of SMA phenotype. Extended deletions that include the neuronal apoptosis inhibitory protein (NAIP) gene may correlate with the severtity of SMA. gene is present in two highly homologous copies, 1 and 2, but only deletions of the 1 gene (exons 7 and 8 or exon 7) are responsible for clinical manifestations of SMA. Here, we present the deletion profiling of 1 and NAIP genes in 89 children with SMA from Serbia: 52 patients with type I, 26 with type II, and 11 with type III. The homozygous deletion of the 1 gene was confirmed in 72 of 89 (81%) patients, being the most frequent in SMA type I (48/52): 68 patients (94.4%) with deletion of exons 7 and 8 and 4 patients (5.6%) with deletion of exon 7. The extended deletion including the NAIP gene was detected in 18 of 89 (20.2%) patients, mostly affected with type I. This study has revealed the lower incidence of deletions in the 1 and NAIP genes in families with SMA in Serbia and will provide important information for genetic counselling in these families.

抄録全体を表示

As the performance of each node becomes higher, it is expected that the ad hoc network is used for the community network in which a few thousands of mobile nodes exist. In such a network, the number of hops between a source node and a destination node also becomes longer. However, as the route becomes longer, it is difficult to provide the robust and reliable route for mobile ad hoc networks since the multiple route breaks occur at the same time due to the topology change. Therefore, this paper proposes a Route-Split Routing resilient to simultaneous failure (RSR). RSR sets up multiple Subroute Management Nodes ('s) on the route and each manages the subroute between the and the neighboring . When the multiple route breaks occur at the same time, each subroute is repaired by the . Consequently, RSR can reduce the number of control packets used for the route repair and mitigate the network congestion even in case that the number of nodes in the network becomes very larger.

抄録全体を表示

Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder characterized by degeneration of the anterior horn of the spinal cord and muscle atrophy, most commonly caused by the survival motor neuron 1 (

) on chromosome 5 (5q13). The severity ranges according to time of onset and is classified as type 0–4. is paralogous to , and the copy number of the is an important determinant of SMA severity. That is, a greater number of copies can generate more protein and presents milder SMA phenotypes. A series of novel therapies have been approved for SMA in recent years, which include nusinersen, a nucleic acid drug using antisense oligonucleotides ; onasemnogene abeparvovec–xioi, a gene therapy drug ; and risidiplam, a small molecule drug. Each has different routes and intervals of administration, but all are designed to increase protein. Clinical trials have shown positive effect on survival, respiratory function, as well as motor function. In order to achieve higher efficacy, evidences have shown that initiation of the treatment as early as possible is essential. In this term, a newborn screening system is being developed for early diagnosis. The further accumulation of data to assess the long–term efficacy and safety of these drugs are needed.

抄録全体を表示

Spinal muscular atrophy (SMA) is an autosomal recessive lower motor neuron degenerative disease. Approximately 90% of patients do not produce normal survival motor neuron (

) protein due to deletion or mutation of the gene. Instead, the gene produces protein, but when transcribed into mRNA, exon7 is skipped by about 90%, and full–length functional protein is produced by only about 10%. Intrathecal nusinersen in 2017 and oral risdiplam in 2021 became available as treatments for adult SMA. The importance of diagnosing SMA with therapeutic agents is increasing. Nusinersen is an antisense oligonucleotide preparation that modifies splicing of gene. After the 3–month introduction period, maintenance administration will be performed every 6 months. Since the administration interval is different from overseas, the therapeutic effect overseas does not always match the therapeutic effect in this method. Intramedullary approach may be required under fluoroscopy in patients who have difficulty with normal lumbar puncture due to scoliosis. Risdiplam is also a small molecule compound that modifies splicing gene. Adult SMA patients are now able to choose between two treatments. Diagnosis will become more and more important in the future.

抄録全体を表示

Spinal muscular atrophy (SMA) is a lower motor neuron disease caused by a deficiency of survival motor neuron (

) protein due to deletions or mutations in the gene. In SMA patients, protein is produced from the paralogous gene , but the produced amount of is minimal due to a defect in the splicing process. Nusinersen, an antisense oligonucleotides, and risdiplam, an oral small molecule, have been developed to repair splicing failure for full amount of production. Nusinersen has been used in clinical practice in these years and the improvement of clinical score has been observed even in adult patients with long disease duration. Thus, it has led to a dramatic evolution for SMA treatment. Risdiplam has the advantage of oral administration and the accumulation of real–world data on its efficacy in adult patients is now ongoing. In addition, onasemnogene abeparvovec utilizes a nonreplicating adeno–associated virus 9 to provide a copy of the gene encoding the protein and is applicable for patients younger than 2 years of age. Onasemnogene has significantly improved the prognosis of severe cases with SMA. Since these drugs are extremely costly and their treatment responses differ between individuals, discontinuation or replacement with another drug should be considered if they are truly ineffective. However, it is not always easy to determine the efficacy of treatment by clinical scores, especially in adult patients with slow progression of the disease. Therefore, the development of reliable biomarkers is underway that can objectively help to evaluate the treatment efficacy. In addition to the molecular markers such as neurofilament H, creatinine, and cathepsin D, microRNA is attracting attention. SMA therapy is a representative example of a successful treatment for neurodegenerative diseases and is expected to have a major impact on the development of future treatments for many intractable neurological diseases.

抄録全体を表示

Background: Spinal muscular atrophy (SMA) is a lower motor neuron disease caused by

. Several clinical trials have indicated that valproic acid (VPA) benefits a limited number of SMA patients. To clarify the difference in VPA responsiveness and elucidate the mechanism, we analyzed gene expression changes by VPA treatment in Japanese pediatric patients using data from clinical trials.

Methods: To identify VPA responders, we correlated the changes in motor function and survival motor neuron (

) protein levels. To determine the effects of VPA on gene expression profiles, a microarray analysis was performed. The Gene Ontology (GO) analysis evaluated statistically overexpressed GO terms within a group of genes.

Results: The group with significant improvement showed elevated

protein levels following VPA administration, whereas that with the highest levels at baseline did not improve immediately. GO analysis suggested that specific factors contributed to the correlation between changes in motor function and the protein levels, including splicing factors HNRNPC and SNRNP70.

Conclusions: This is the first study to indicate that the time for VPA effectiveness varies among individuals and is associated with

protein levels at baseline and expression changes in splicing factor genes.

Clinical Trials Registry of the Center for Clinical Trials, Japan Medical Association, a registry of the Japan Primary Registries Network certified by the World Health Organization as a primary registry (registration numbers: SMART01 trial, JMA-II A00190; SMART02 trial, JMA-II A00231; SMART03 trial, JMA-II A00259).

抄録全体を表示

Loss–of–function mutations in

cause spinal muscular atrophy (SMA), a leading genetic cause of infant mortality. Humans have a closely related , but it only expresses low levels of protein, due to alternative splicing of exon 7. Antisense oligonucleotides (ASOs) can be designed to regulate splicing of target pre–mRNAs. Based on an ASO–tiling method, we succeeded in identifying an optimized 2′–MOE phosphorothioate ASO that efficiently redirects splicing. Its therapeutic efficacy, safety, and pharmacokinetics were proven in preclinical studies using mice and NHPs and further supported by clinical trials in SMA infants and children. Exploring of the in vivo spatial and temporal ASO effects yields insights into roles in SMA pathogenesis, which in turn contributes to the successful development of targeted therapeutics.

抄録全体を表示

In July 2017, a nucleic acid agent (drug name : Nusinersen) for patients with spinal muscular atrophy (SMA) obtained manufacturing approval in Japan. The functional full length survival motor neuron (

) protein is only minimally produced by the gene in patients with SMA. The mechanism of action of Nusinersen involves binding to the hnRNP–A1/A2–dependent splicing silencer region in the pre–mRNA of , which is responsible for impaired binding of hnRNP–A1/A2 to the pre–mRNA, and inclusion of exon 7. The full–length protein is synthesized due to this exon inclusion. At present, new SMA treatments are under development. These novel approaches include intrathecal administration of nucleic acid agents, oral administration of small molecules, and gene therapy using viral vectors. The effectiveness and safety of these treatments are being evaluated by international joint clinical trials. Early diagnosis and intervention at an early disease stage by genetic testing have become important at medical sites worldwide, in anticipation of slowing or even halting the symptoms of SMA as well as preventing the onset of this disease.

抄録全体を表示

Loss–of–function mutations in

cause spinal muscular atrophy (SMA), a leading genetic cause of infant mortality. Humans have a closely related , but it only expresses low levels of protein, due to alternative splicing. Based on clinical trials showing a significant increase in survival and motor development in SMA infants and children, an splicing–correcting antisense oligonucleotide has been approved as the disease–modifying drug for SMA. Development of therapies and advanced medical care have dramatically improved the prognosis of SMA. Collected clinical data will allow filling the current gaps in our knowledge of SMA natural history during adult life and the drug efficacy especially for long–term chronic progressors.

抄録全体を表示

Nusinersen (Spinraza^®), the first approved medicine for spinal muscular atrophy (SMA), exemplifies a successful path from basic studies of cellular mechanisms to an effective treatment for a devastating disease. This successful clinical application comes >120 years after the first description of the disease, and 40 years after the discovery of RNA splicing and the first reported use of antisense technology.

SMA is a motor-neuron disease, caused by mutations in

. Patients retain one or more copies of the nearly identical gene, which mainly expresses mRNA lacking exon 7, coding for an unstable protein isoform. The small amount of full-length mRNA and protein expressed from only partially compensates for the loss of . Together with Ionis Pharmaceuticals, we developed nusinersen, a splice-switching antisense oligonucleotide (ASO) that efficiently promotes exon 7 inclusion and restores protein levels. Nusinersen hybridizes to intron 7 of the pre-mRNA, preventing binding of the splicing repressors hnRNPA1/A2 to a bipartite intronic splicing silencer; this in turn facilitates binding of U1 snRNP to the intron 7 5' splice site, resulting in enhanced exon 7 inclusion. Clinical trials of nusinersen in SMA patients, sponsored by Ionis and Biogen, began at the end of 2011. Based on the results of two phase-3 trials in infants with the most severe form of SMA, and in children with an intermediate form of SMA, respectively, Spinraza was approved by the FDA in December 2016, for all SMA types. It was subsequently approved in Europe and Japan in 2017.

We are continuing to explore aspects of SMA pathogenesis and treatment, using ASO therapy in SMA mouse models. We are also exploring prenatal ASO treatment, as it is likely that early intervention will maximize the clinical benefit.

抄録全体を表示

Hypertension affects many people and increases the risk of serious illnesses. Blood pressure (BP) can be reduced by decreasing heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR). We aimed to investigate non-pharmaceutical therapy for reducing hypertension by evaluating the effects of self-administered high-voltage, low-frequency (HV-LF) electrical stimulation of peripheral nerves in the limbs. The hypothesis was that such stimulation would induce a decrease in HR and increase skin blood flow (SBF), leading to a decrease in BP. A crossover trial was used to verify the effects of stimulation of the median nerve (

) and superficial peroneal nerve (SSPN) in 16 healthy adult male participants. Patients with hypertension were excluded from the study. Stimulation was performed at 1 Hz for 20 s using an electrical stimulator capable of generating high voltage using a piezoelectric element. HR, SV, and CO were evaluated as parameters of circulatory dynamics, while SBF was an indicator of peripheral blood flow. TPR was calculated from BP and CO values. BP was significantly lower following both and SPPN. In , an immediate decrease in HR and an increase in SBF were observed. In SPPN, transient decreases in HR and CO and an increase in SBF were observed. Thus, both stimuli affected circulatory dynamics and local blood flow, supporting the hypothesis. However, TPR remained unchanged, indicating that the effect of blood pressure reduction was mainly due to central circulation suppression rather than SBF. The decreases in HR and BP were similar in the and SSPN groups; however, CO and SBF showed different response trends in the two groups. This difference suggests that the primary factors that decrease BP may differ between and SSPN, and that this should be investigated further. Thus, self-administered HV-LF electrical stimulation of superficial skin nerves, as used in this study, may be useful as a novel non-pharmacological intervention for the treatment of hypertension, although further studies are needed to optimize stimulation parameters in patients with hypertension.

抄録全体を表示

Spinal muscular atrophy (SMA) is a lower motor neuron disease characterized by muscle atrophy and progressive muscle weakness due to the degeneration and loss of anterior horn cells of the spinal cord. For a long time, it was a disease that received only care in hospitals and at home as a disease without cure. SMA is caused by the deletion or mutation of the survival of motor neuron 1 (

) gene, therefore only a small amount of functional full-length survival motor protein () protein is produced from the gene. There are three disease-modifying therapies that increase the production of the protein: nusinersen, a nucleic acid drug with an exon inclusion mechanism; risdipram, a small molecule-drug with a similar mechanism; and onasemnogene abeparvovec, an adeno-associated virus 9 vector containing the gene. Each drug was listed on the national health insulance (NHI) drug price based on the success of global clinical trials in which the author acted as the principal investigator. With the development of these effective therapeutic agents, early diagnosis and early treatment are essential. By administering the drug before the symptoms appear, it is possible to suppress or reduce the symptoms of SMA, and newborn screening at a nationwide level is expected to realized.

抄録全体を表示

Spinal Muscular Atrophy (SMA) is an autosomal recessive lower motor neuron degenerative disease. About 90% of patients do not produce normal

protein due to deletion of the gene. Instead, 2 gene produces protein, but when transcribed into mRNA, exon 7 is slipped by about 90%, and full–length functional protein is produced by only about 10%. In July 2017, nusinersen became available as a therapeutic agent for SMA. Expected to strengthen muscle strength and maintain function. Nusinersen treatment for adult SMA patients is performed by the Department of Neurology, but there is still insufficient information regarding nusinersen for adult SMA patients. In pediatric case such as SMA type 1 or 2, a visible muscle strengthening effect such as acquisition of standing walking can be expected, but the therapeutic effect in adult SMA patients is unknown. The Department of Neurology, Kagoshima University provides this treatment to 16 adult SMA patients. HFMSE (Hammersmith functional motor scale–expanded), RULM (Revised upper limb module), respiratory function, and 6–minute walking for walkable patients are evaluated as therapeutic effect. Normal lumbar puncture is difficult for patients who have severe scoliosis or surgery for scoliosis. In such case, cooperation with other departments such as orthopedics and anesthesiology is required. There is little information on long–term effects, but patients have high expectations.

抄録全体を表示