• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.163-170
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• 2021

Enzyme replacement therapy for lysosomal storage diseases usually requires recombinant enzymes containing mannose-6-phosphate (M6P) glycans for cellular uptake and lysosomal targeting. For the first time, a strategy is established here for the in vitro mannosyl-phosphorylation of high-mannose type N-glycans that utilizes a recombinant Mnn14 protein derived from Saccharomyces cerevisiae. Among a series of N-terminal- or C-terminal-deleted recombinant Mnn14 proteins expressed in Pichia pastoris, rMnn1477-935 with deletion of N-terminal 76 amino acids spanning the transmembrane domain (46 amino acids) and part of the stem region (30 amino acids), showed the highest level of mannosyl-phosphorylation activity. The optimum reaction conditions for rMnn1477-935 were determined through enzyme assays with a high-mannose type N-glycan (Man8GlcNAc2) as a substrate. In addition, rMnn1477-935 was shown to mannosyl-phosphorylate high-mannose type N-glycans (Man7-9GlcNAc2) on recombinant human lysosomal alpha-glucosidase (rhGAA) with remarkably high efficiency. Moreover, the majority of the resulting mannosyl-phosphorylated glycans were bis-form which can be converted to bis-phosphorylated M6P glycans having a superior lysosomal targeting capability. An in vitro N-glycan mannosyl-phosphorylation reaction using rMnn1477-935 will provide a flexible and straightforward method to increase the M6P glycan content for the generation of "Biobetter" therapeutic enzymes.

• Journal of mucopolysaccharidosis and rare diseases
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• 제5권1호
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• pp.12-16
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• 2021

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-linked lysosomal storage disorder caused by deficiency of the enzyme iduronate-2-sulfatase, leading to the accumulation of glycosaminoglycans (GAGs), which affects multiple organs and systems. Current treatments for MPS II include enzyme replacement therapy (ERT) and hematopoietic cell transplantation (HCT) to reduce the accumulation of GAGs. HCT has the potential advantage that donor-derived enzyme-competent cells can provide a continuous secreting source of the enzyme. However, HCT as a treatment for MPS II remains controversial because its effectiveness is unclear, particularly in terms of neurological symptoms. To date, several clinical experiences with HCT in MPS II have been reported. In this paper, we review post-HCT outcomes in the previously published literature and discuss the effects of HCT on each of the clinical signs and symptoms of MPS II.

• Journal of mucopolysaccharidosis and rare diseases
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• 제4권1호
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• pp.14-20
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• 2018

Mucopolysaccharidoses (MPSs) are a group of rare inherited metabolic disorders caused by specific lysosomal enzyme deficiencies leading to the sequential degradation of glycosaminoglycans, causing substrate accumulation in various cells and tissues and progressive multiple organ dysfunction. The rare disease medical care team at Mackay Memorial Hospital in Taiwan has been dedicated to the study of MPSs for more than 20 years. Since 1999, more than 50 academic papers focusing on MPSs have been published in international medical journals. Topics of research include the following items regarding MPSs: incidence, natural history, clinical manifestations, gene mutation characteristics, cardiac function, bone mineral density, sleep studies, pulmonary function tests, hearing assessments, percutaneous endoscopic gastrostomy, anesthetic experience, imaging analysis, special biochemical tests, laboratory diagnostics, global expert consensus conferences, prenatal diagnosis, new drug clinical trials, newborn screening, and treatment outcomes. Of these published academic research papers, more than half were cross-domain, cross-industry, and international studies with results in cooperation with experts from European, American and other Asian countries. A cross-specialty collaboration platform was established based on high-risk population screening criteria with the acronym "BECARE" (Bone and joints, Eyes, Cardiac and central nervous system, Abdomen and appearance, Respiratory system, and Ear, nose, and throat involvement). Through this platform, orthopedic surgeons, rheumatologists, ophthalmologists, cardiologists, rehabilitation physicians, gastroenterologists, otorhinolaryngologists, and medical geneticists have been educated with regards to awareness of suspected cases of MPSs patients to allow for a further confirmative diagnosis of MPSs. Because of the progressive nature of the disease, an early diagnosis and early multidisciplinary therapeutic interventions including surgery, rehabilitation programs, symptom-based treatments, hematopoietic stem cell transplantation, and enzyme replacement therapy, are very important.

• 대한유전성대사질환학회지
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• 제14권2호
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• pp.156-162
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• 2014

A 25-month-old boy was referred to the hospital due to large head detected on routine physical examination. At visit, dysmorphic facial appearances, including broad nose, prominent forehead, and coarse face, were noted. Nasal obstruction with nasal voice, prominent adenoids, and bilateral middle ear effusions were detected. His abdomen was distended, and liver and spleen were palpated about 3 finger and 2 finger breadths, respectively. He was operated for bilateral inguinal hernias. The motion of both elbow joints was mildly limited on supination and pronation. Urinary level of glycosaminoglycan was elevated and the enzyme activity of iduronate sulfatase in leukocytes was decreased. The mutational analysis of the gene iduronate 2-sulfatase (IDS) revealed c.263G>A (p.Arg88His) mutation. His developmental scale showed delayed development and there was cardiac valvular involvement (tricuspid regurgitation and mitral valve prolapse). After the diagnosis of Hunter syndrome, enzyme replacement therapy started on a weekly basis without progression of any clinical features. Here we report a case of early diagnosed Hunter syndrome detected by large head on routine examination. Thus, it is important to associate Hunter syndrome in the patient with large head especially, if there is the history of bilateral inguinal hernia and prominent adenoids to increase the possibility of early diagnosis and treatment.

• 대한유전성대사질환학회지
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• 제11권1호
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• pp.27-32
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• 2011

최근 유전공학의 발달로 리소좀 축적 질환에서 효소 치료제가 개발되어 실제 치료에 사용되고 있다. 현재 효소 보충 치료가 가능한 리소좀 축적 질환에는 고셔병(Gaucher disease), 파브리병(Fabry disease), 폼페병(Pompe disease), 뮤코다당체침착병(Mucopolysaccharidosis, MPS) 1형, 2형, 6형이 있으며 비교적 안전하면서 증상 완화에도 효과적으로 보인다. 그러나 이미 진행이 된 증상에 대해서는 비가역적이므로 조기에 진단을 하여 치료를 시작하는 것이 중요하다. 효소 보충 치료의 장기간에 걸친 치료 효과에 대해서 지속적인 평가가 필요하며 무엇보다 뼈와 중추신경계에 대한 효과는 제한적이므로 이에 대한 새로운 치료법의 개발이 필요하다.

• Journal of Genetic Medicine
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• 제17권2호
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• pp.62-67
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• 2020

Purpose: Eliglustat is an oral substrate reduction therapy (SRT) approved for adults with Gaucher disease type I (GD1) who are extensive, intermediate, or poor CYP2D6 metabolizers. Here we report one-year experience of eliglustat switch therapy from long-term enzyme replacement therapy (ERT) in three adult patients with GD1. Materials and Methods: Medical history, clinical (hemoglobin concentration, platelet count, and bone mineral density) and biochemical parameters (angiotensin converting enzyme, total acid phosphatase, and lyso-gb1) of the patients were collected and evaluated by retrospective review of medical records at every 3, 6, or 12 month after switch to SRT. Results: Patient 1 was a 43-year old female diagnosed GD1 and her clinical and biochemical parameters were stabilized for more than 20 years by ERT. Due to the burden of regular hospital visit, she switched to SRT. During one-year of SRT, clinical parameters and biomarkers were maintained stable. However, after suffering acute febrile illness during SRT, she decided to re-switch to ERT due to concerns about drug interaction. Patient 2 was 41-year old male, younger brother of patient 1 and Patient 3 was 31-year old male. They switched to SRT in clinically stable condition with long-term ERT. The one-year SRT was tolerable without specific safety issue and the clinical parameters were maintained stable. Conclusion: One-year eliglustat therapy in three adult patients with GDI was generally tolerable and effective for maintaining the clinical parameters and biomarkers. However, the drug compliance, concurrent drug interactions, and long-term safety of eliglustat should be carefully monitored.

• Childhood Kidney Diseases
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• 제27권2호
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• pp.121-126
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• 2023

The administration of angiotensin type 2 receptor blockers (ARBs) during pregnancy is known to cause ARB fetopathy, including renal insufficiency. We aimed to analyze the outcomes of two patients who survived ARB fetopathy and perform an accompanying literature review. Case 1 was exposed antenatally from a gestational age of 30 weeks to valsartan because of maternal pregnancy-induced hypertension. The patient presented with oliguria immediately after birth, and renal replacement therapy was administered for 24 days. Seven years after birth, renal function was indicative of stage 2 chronic kidney disease (CKD) with impaired urinary concentration. Case 2 had a maternal history of hypertension and transient ischemic attack and was treated with olmesartan until 30 weeks of pregnancy. Renal replacement therapy was performed for 4 days since birth. After 8 years, the patient is with CKD stage 2, with intact tubular function. Recent reports suggest that ARB fetopathy might manifest as renal tubular dysgenesis and nephrogenic diabetes insipidus, in contrast to mild alterations of glomerular filtration. Tubular dysfunction may induce CKD progression and growth retardation. Patients with ARB fetopathy should be monitored until adulthood. The ARB exposure period might be a critical factor in determining the severity and manifestations of fetopathy.

• Journal of mucopolysaccharidosis and rare diseases
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• 제3권1호
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• pp.1-8
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• 2017

Mucopolysaccharidosis (MPS) type III, or Sanfilippo syndrome is a rare autosomal recessive lysosomal storage disorder. It is caused by a deficiency of one of four enzymes involved in the degradation of the glycosaminoglycan (GAG) heparan sulfate. The resultant cellular accumulation of heparan sulfate causes various clinical manifestations. MPS III is divided into four subtypes depending on the deficient enzyme: MPS IIIA, MPS IIIB, MPS IIIC and MPS IIID. All the subtypes show similar clinical features and are characterized by progressive degeneration of the central nervous system (CNS). Main purpose of the treatment for MPS III is to prevent neurologic deterioration. However, conventional enzyme replacement therapy has a limitation due to inability to cross the blood-brain barrier. Several experimental treatment options for MPS III are being developed.

• Biomolecules & Therapeutics
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• 제17권1호
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• pp.104-110
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• 2009

Phenylketonuria (PKU) is an inherited metabolic disorder caused by mutations in the phenylalanine catabolic enzyme, phenylalanine hydroxylase (PAH). The use of phenylalanine ammonia-lase (PAL) by oral and parenteral routes as a therapeutic drug for PKU has been severely limited due to inactivation by intestinal proteolysis and immune reactions. PEGylation was applied to PAL to reduce the degrees of antigenicity and proteolytic inactivation. Kinetic experiments with native PAL and pegylated PALs were performed, and pH stability, temperature stability, and protease susceptibility were evaluated. Enzyme linked immunosorbent assay (ELISA) was carried out to measure the immune complex between pegylated PALs and antiserum that had been extracted from a PAL-immunized mouse. Pegylated PAL, especially branched pegylated PAL (10 kDa, 1:32), was more active for phenylalanine and more stable in pancreatic proteases than native PAL. Native PAL was optimal at pH 8.5, corresponding to the average pH range of the small intestine; the same finding was noted for pegylated PALs. All linear and branched pegylated PALs had low reactivity with mouse antiserum, especially the 1:16 formulation with linear 5-kDa PEG and the 1:32 formulation with branched 10-kDa PEG. Therefore, we suggest the 1:32 formulation with branched 10-kDa PEG as the most promising formulation for enzyme replacement therapy.

• 대한유전성대사질환학회지
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• 제16권3호
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• pp.117-122
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• 2016

제1형 고셔병(Gaucher disease type 1)은 리소좀 효소인 산성 ${\beta}$-글루코시다아제(acid ${\beta}-glucosidase$)의 결핍으로 인한 리소솜 축적 질환이다. 효소 활성도가 감소되어 기질이 축적되어, 간비종대, 빈혈, 혈소판감소증 및 골질환을 포함한 전신 증상이 발생한다. 재조합 효소 단백을 정맥 주입하는 효소 대체요법(Enzyme replacement therapy)는 지난 20년 넘게 고셔병의 표준 치료법이었다. 그러나 성공적인 효소 대체요법에도 불구하고, 심각한 폐증상과 골격 증상 등 고셔병 치료에 여전히 해결되지 않는 문제들이 남아 있다. 기질 감소 치료(Substrate reduction therapy)는 기질의 생합성을 억제하여 축적을 감소시킨다. 최근 새로운 경구용 기질감소 치료제인 엘리글루스타트(eliglustat)가 적합한 CYP2D6 대사 표현형을 가진 고셔병 성인 환자를 위한 1차 치료제로 미국과 유럽에서 승인되었다. 엘리글루스타트가 아직 한국에서는 쓰이지 않고 있지만, 본 종설에서는 문헌 검토를 통해 고셔병의 새로운 치료로서의 효소 대체요법을 소개하고자 한다. 아직 확고한 결론을 도출하기에는 연구 결과가 제한적이기는 하지만, 현재까지의 데이터에 따르면 엘리글루스타트는 임상 효능에 있어서 효소 보충 요법에 비열등성을 보인다. 장기 결과에 대한 추가 연구가 필요하지만, 엘리글루스타트의 승인은 해당 1형 고셔병 성인 환자들에게 경구 치료제라는 새로운 선택을 가능하게 하였다. 향후 국내에서 엘리글루스타트가 처방 가능해 지면, 각 환자 마다 철저한 평가를 통해 치료법을 선택할 수 있도록 해야 할 것이다. 나아가, 국내 1형 고셔병 환자들을 위해 엘리글루스타트의 사용에 관한 임상적 지침 또한 조만간 개발될 필요가 있다.