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American Journal of Human Genetics Feb 2016Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the...
Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are challenging. Exome sequencing in a family with three siblings affected by abnormal Golgi glycosylation revealed a homozygous missense mutation, c.92T>C (p.Leu31Ser), in coiled-coil domain containing 115 (CCDC115), the function of which is unknown. The same mutation was identified in three unrelated families, and in one family it was compound heterozygous in combination with a heterozygous deletion of CCDC115. An additional homozygous missense mutation, c.31G>T (p.Asp11Tyr), was found in a family with two affected siblings. All individuals displayed a storage-disease-like phenotype involving hepatosplenomegaly, which regressed with age, highly elevated bone-derived alkaline phosphatase, elevated aminotransferases, and elevated cholesterol, in combination with abnormal copper metabolism and neurological symptoms. Two individuals died of liver failure, and one individual was successfully treated by liver transplantation. Abnormal N- and mucin type O-glycosylation was found on serum proteins, and reduced metabolic labeling of sialic acids was found in fibroblasts, which was restored after complementation with wild-type CCDC115. PSI-BLAST homology detection revealed reciprocal homology with Vma22p, the yeast V-ATPase assembly factor located in the endoplasmic reticulum (ER). Human CCDC115 mainly localized to the ERGIC and to COPI vesicles, but not to the ER. These data, in combination with the phenotypic spectrum, which is distinct from that associated with defects in V-ATPase core subunits, suggest a more general role for CCDC115 in Golgi trafficking. Our study reveals CCDC115 deficiency as a disorder of Golgi homeostasis that can be readily identified via screening for abnormal glycosylation in plasma.
Topics: Amino Acid Sequence; Child; Child, Preschool; Cloning, Molecular; Endoplasmic Reticulum; Exome; Female; Fibroblasts; Glycosylation; Golgi Apparatus; HeLa Cells; Heterozygote; Homeostasis; Humans; Infant; Male; Molecular Sequence Data; Nerve Tissue Proteins; Pedigree; Phenotype; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 26833332
DOI: 10.1016/j.ajhg.2015.12.010 -
Glia May 2016CLN diseases are mostly fatal lysosomal storage diseases that lead to neurodegeneration in the CNS. We have previously shown that CD8+ T-lymphocytes contribute to axonal...
CLN diseases are mostly fatal lysosomal storage diseases that lead to neurodegeneration in the CNS. We have previously shown that CD8+ T-lymphocytes contribute to axonal perturbation and neuron loss in the CNS of Ppt1(-/-) mice, a model of CLN1 disease. We now investigated the role of the inflammation-related cell adhesion molecule sialoadhesin (Sn) in Ppt1(-/-) and Cln3(-/-) mice, a model of the most frequent form, CLN3 disease. Microglia/macrophages in the CNS of both models showed an upregulation of Sn and markers for proinflammatory M1 polarization and antigen presentation. Sn+ microglia/macrophages associated with SMI32+ axonal spheroids and CD8+ T-lymphocytes. To analyze their pathogenic impact, we crossbred both models with Sn-deficient mice and scored axonal degeneration and neuronal integrity using immunohistochemistry, electron microscopy and optical coherence tomography. Degenerative alterations in the retinotectal pathway of Ppt1(-/-)Sn(-/-) and Cln3(-/-)Sn(-/-) mice were significantly reduced. Ppt1(-/-)Sn(-/-) mice also showed a substantially improved clinical phenotype and extended lifespan, attenuated numbers of M1-polarized microglia/macrophages and reduced expression levels of proinflammatory cytokines. This was accompanied by an increased frequency of CD8+CD122+ T-lymphocytes in the CNS of Ppt1(-/-)Sn(-/-) mice, the regulatory phenotype of which was demonstrated by impaired survival of CD8+CD122- effector T-lymphocytes in co-culture experiments. We show for the first time that increased Sn expression on microglia/macrophages contributes to neural perturbation in two distinct models of CLN disease. Our data also indicate that a rarely described CD8+CD122+ T-cell population can regulate the corresponding diseases. These studies provide insights into CLN pathogenesis and may guide in designing immuno-regulatory treatment strategies.
Topics: Animals; Antigens, CD; Astrocytes; CD8-Positive T-Lymphocytes; Calcium-Binding Proteins; Central Nervous System; Disease Models, Animal; Disease Progression; Encephalitis; Macrophages; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microfilament Proteins; Microglia; Molecular Chaperones; Neuronal Ceroid-Lipofuscinoses; Retina; Sialic Acid Binding Ig-like Lectin 1; Thiolester Hydrolases; Tomography, Optical Coherence
PubMed: 26775238
DOI: 10.1002/glia.22962 -
Indian Pediatrics Dec 2015To study the etiology of neuroregression in children having deficiency of the lysosomal enzymes.
OBJECTIVE
To study the etiology of neuroregression in children having deficiency of the lysosomal enzymes.
DESIGN
Review of medical records.
SETTING
Specialized Genetic Center.
PARTICIPANTS
432 children aged 3 mo-18 y having regression in a learned skill, selected from 1453 patients referred for diagnostic workup of various Lysosomal storage disorders (LSDs).
METHODS
Plasma chitotriosidase, quantitative and qualitative glycosaminoglycans, and mucolipidosis-II/II screening followed by confirmatory enzyme study using specific substrate was carried out; Niemann-Pick disease Type-C was studied by fillipin stain method on skin fibroblasts.
RESULTS
Total 309 children (71.5%) were diagnosed with different lysosomal storage disorders as the underlying cause of neuroregression. Plasma chitotriosidase was raised in 82 of 135; 64 (78%) of these had various LSDs. 69 out of 90 cases showed high excretion of glycoaminoglycans, and 67 (97.1%) of these were confirmed to have enzyme deficiency for various mucoplysaccharide disorders. While 3 of 90 children with positive Icell screening had confirmed mucolipidosis II/III disease. Among all, glycolipid storage disorders were the most common (50.2%) followed by mucopolysaccharidosis (MPS) (21.7%) and sulphatide degradation defect (17.5%). Neuronal ceroid lipofucinosis1 and 2 (7.4%), mucolipidosis-II/III (1%), Sialic acid storage disorder (1%), Niemann-Pick disease type-C (1%) and Fucosidosis (0.3%) were observed with less frequency. Most common phenotypes in all subjects were cherry red spot (18.5%), hepatosplenomegaly (17.9%), coarse facies (15%), seizures (13.1%) and skeletal abnormalities (12.14%).
CONCLUSIONS
Lysosomal storage disorders are considered to be one of the common causes in children with regression in learned skill, dysmorphic features and cherry red spot. Among these, glycolipid storage disorders are the most common, followed by mucopolysaccharidosis.
Topics: Adolescent; Child; Child, Preschool; Cohort Studies; Developmental Disabilities; Genetic Counseling; Humans; India; Infant; Lysosomal Storage Diseases
PubMed: 26713986
DOI: 10.1007/s13312-015-0768-x -
Frontiers in Pediatrics 2015Cronobacter is a class of Enterobacteriaceae that cause infections in neonates, especially those born prematurely. Over 90% of these infections have been linked... (Review)
Review
Cronobacter is a class of Enterobacteriaceae that cause infections in neonates, especially those born prematurely. Over 90% of these infections have been linked epidemiologically to powdered infant formula (PIF). Contamination of PIF can occur at manufacture, reconstitution, or storage of reconstituted product. Intrinsic properties that enable Cronobacter to cause disease include resistance to heat, ultraviolet radiation, oxygen radicals, stomach acids, and pasteurization; an ability to utilize sialic acid (a nutrition additive to PIF that facilitates the organism's growth and survival), and an exceptional affinity for biofilms in enteral feeding tubes. As part of ongoing endeavors to reduce the incidence of neonatal PIF-associated Cronobacter infections, the World Health Organization and the US Food and Drug Administration have established guidelines for PIF production, preparation for infant feeding, and storage of reconstituted product.
PubMed: 26191519
DOI: 10.3389/fped.2015.00056 -
Journal of Neurodevelopmental Disorders 2015Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by...
BACKGROUND
Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by mutations in the SLC17A5 gene. The aim of the study was to investigate the course of neurocognitive features of SD patients in a long-term follow-up.
METHODS
Neuropsychological and neurological investigations were carried out on 24 SD patients, aged 16-65 years, 13 years after a similar examination.
RESULTS
The survival analysis showed excess mortality among patients with SD after the age of 30 years. The course of the disease was progressive, but follow-up of SD patients revealed that motor skills improved till the age of 20 years, while mental abilities improved in most patients till 40 years of age. Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria. Motor deficits were marked. Ataxia was prominent in childhood, but it was replaced by athetotic movements during the teens. Spasticity became more obvious with age especially in severely disabled SD patients.
CONCLUSIONS
Younger SD patients performed better in almost every task measuring mental abilities that then seem to remain fairly constant till early sixties. Thus, the results indicate better prognosis in cognitive skills than earlier assumed. There is an apparent decline in motor skills after the age of 20 years. The early neurocognitive development predicts the later course of motor and cognitive development.
PubMed: 26171070
DOI: 10.1186/s11689-015-9116-7 -
Methods in Molecular Biology (Clifton,... 2015Insect cells lack the ability to synthesize the sialic acid donor molecule CMP-sialic acid or its precursor, sialic acid. In this chapter, we describe a method to...
Insect cells lack the ability to synthesize the sialic acid donor molecule CMP-sialic acid or its precursor, sialic acid. In this chapter, we describe a method to engineer CMP-sialic acid synthesis capability into Spodoptera frugiperda (Sf9) cells, a prototypical insect cell line, by recombinant expression of sialic acid synthesis pathway genes using baculovirus technology. Co-expression of a sialuria mutant UDP-GlcNAc-2-epimerase/ManNAc kinase (EKR263L), wild-type sialic acid 9-phosphate synthase (SAS), and wild-type CMP-sialic acid synthetase (CSAS) in the presence of GlcNAc leads to synthesis of CMP-sialic acids synthesis to support sialylation of N-glycans on glycoproteins.
Topics: Animals; Baculoviridae; Genetic Engineering; Glycoproteins; Insecta; N-Acetylneuraminic Acid; Polysaccharides; Recombinant Proteins; Spodoptera
PubMed: 26082222
DOI: 10.1007/978-1-4939-2760-9_12 -
Journal of Obstetrics and Gynaecology :... 2015
Topics: Female; Humans; Hydrops Fetalis; Pregnancy; Sialic Acid Storage Disease; Young Adult
PubMed: 26076308
DOI: 10.3109/01443615.2015.1017558 -
Pediatric and Developmental Pathology :... 2014Galactosialidosis (GS) is a rare autosomal recessive lysosomal storage disease caused by a combined deficiency of lysosomal β-galactosidase and neuraminidase as a...
Galactosialidosis (GS) is a rare autosomal recessive lysosomal storage disease caused by a combined deficiency of lysosomal β-galactosidase and neuraminidase as a result of a genetic defect in the protective protein/cathepsin A gene. We report a case of unsuspected fetal galactosialidosis presenting as severe intrauterine growth restriction and oligohydramnios prenatally and as hyperinsulinemic hypoglycemia in the immediate postnatal period. Placental pathology examination showed striking vacuolations of the villous syncytiotrophoblast, extravillous trophoblast, and villous Hofbauer cells. Electron microscopy revealed numerous membrane-bound electron-lucent lysosomes, mainly within the syncytiotrophoblast. The characteristic histologic and ultrastructural placental findings prompted biochemical and molecular genetic testing for fetal storage disease. Enzyme activity of β-galactosidase was decreased in leukocytes and fibroblasts. Sialic acid content was elevated. Molecular genetic studies revealed 3 variants--c.108, 110delGCT(L37del), c.1045T>A (C349S), and c.1321C>T(R441C)--of the cathepsin A gene, the latter 2 of which have not been previously reported. These findings are consistent with galactosialidosis. We emphasize the importance of following the accepted practice guideline for the examination of the placenta in discovering unsuspected fetal metabolic disorders.
Topics: Adult; Biopsy; Cathepsin A; DNA Mutational Analysis; Female; Genetic Predisposition to Disease; Humans; Infant, Newborn; Lysosomal Storage Diseases; Microscopy, Electron; Mutation; Phenotype; Trophoblasts; Vacuoles
PubMed: 25075748
DOI: 10.2350/14-05-1500-CR.1 -
European Journal of Medical Genetics Sep 2014We describe here a 34 months child, practically asymptomatic which presented with high levels of free sialic acid in urine by biochemical detection in second-tier tests...
We describe here a 34 months child, practically asymptomatic which presented with high levels of free sialic acid in urine by biochemical detection in second-tier tests newborn screening and with two disease causing mutations in SLC17A5 gene. SLC17A5 mutation analysis showed p.Tyr306* previously described and the novel mutation p.Leu167Pro. This early onset diagnosis allowed us to perform a fast and accurate genetic counseling to the family, helped to better understanding the natural history of this rare disease and probably it could promote cost reduction in future diagnostic tests in the hypothetic case of starting symptoms without diagnosis established. Moreover, an early diagnosis could save family from a long period of time until achieving a definitive diagnostic and to develop an early symptomatic and supportive management of patient to attenuate, as much as possible, disease complications. But, above all, this case illustrates the huge ethical dilemma which arises from any secondary finding (second tier) in newborn screening.
Topics: Amino Acid Sequence; DNA Mutational Analysis; Early Diagnosis; Female; Humans; Incidental Findings; Infant; Infant, Newborn; Molecular Sequence Data; Mutation; N-Acetylneuraminic Acid; Neonatal Screening; Organic Anion Transporters; Sequence Alignment; Sialic Acid Storage Disease; Symporters
PubMed: 24993898
DOI: 10.1016/j.ejmg.2014.06.005 -
Glycoconjugate Journal May 2014Mucopolysaccharidosis II (MPS II, Hunter syndrome; OMIM 309900) is an X-linked lysosomal storage disease caused by a deficiency in the enzyme iduronate-2-sulfatase...
Mucopolysaccharidosis II (MPS II, Hunter syndrome; OMIM 309900) is an X-linked lysosomal storage disease caused by a deficiency in the enzyme iduronate-2-sulfatase (IDS), leading to accumulation of glycosaminoglycans (GAGs). For enzyme replacement therapy (ERT) of Hunter syndrome, two recombinant enzymes, idursulfase (Elaprase(®), Shire Human Genetic Therapies, Lexington, MA) and idursulfase beta (Hunterase(®), Green Cross Corporation, Yongin, Korea), are currently available in Korea. To compare the biochemical and physicochemical differences between idursulfase and idursulfase beta, we examined the formylglycine (FGly) content, specific enzyme activity, mannose-6-phosphate (M6P) content, sialic acid content, and in vitro cell uptake activity of normal human fibroblasts of these two enzymes.The FGly content, which determines the enzyme activity, of idursulfase beta was significantly higher than that of idursulfase (79.4 ± 0.9 vs. 68.1 ± 2.2 %, P < 0.001). In accordance with the FGly content, the specific enzyme activity of idursulfase beta was significantly higher than that of idursulfase (42.6 ± 1.1 vs. 27.8 ± 0.9 nmol/min/μg protein, P < 0.001). The levels of M6P and sialic acid were not significantly different (2.4 ± 0.1 vs 2.4 ± 0.3 mol/mol protein for M6P and 12.3 ± 0.7 vs. 12.4 ± 0.4 mol/mol protein for sialic acid). However, the cellular uptake activity of the normal human fibroblasts in vitro showed a significant difference (Kuptake, 5.09 ± 0.96 vs. 6.50 ± 1.28 nM protein, P = 0.017).In conclusion, idursulfase beta exhibited significantly higher specific enzyme activity than idursulfase, resulting from higher FGly content. These biochemical differences may be partly attributed to clinical efficacy. However, long-term clinical evaluations of Hunter syndrome patients treated with these two enzymes will be needed to demonstrate the clinical implications of significant difference of the enzyme activity and the FGly content.
Topics: Alanine; Animals; CHO Cells; Cricetinae; Cricetulus; Enzyme Replacement Therapy; Fibroblasts; Glycine; Humans; Iduronate Sulfatase; Mannosephosphates; Mucopolysaccharidosis II; N-Acetylneuraminic Acid; Recombinant Fusion Proteins
PubMed: 24781369
DOI: 10.1007/s10719-014-9523-0