Publications by authors named "Radhakrishnan Karthikeyan"

Article Synopsis
  • * A combined treatment approach using improved lentiviral (LV) gene therapy with hematopoietic stem cell transplants shows promise for MLD, but requires careful management of vector copy numbers (VCN) to prevent potential toxicity.
  • * The newly developed vector EA1 demonstrates significantly increased ARSA activity compared to existing treatments and effectively restores normal behavior and brain structure in a mouse model of MLD, indicating a safer and more efficient therapy for young patients.
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Sulfatases catalyze essential cellular reactions, including degradation of glycosaminoglycans (GAGs). All sulfatases are post-translationally activated by the formylglycine generating enzyme (FGE) which is deficient in multiple sulfatase deficiency (MSD), a neurodegenerative lysosomal storage disease. Historically, patients were presumed to be deficient of all sulfatase activities; however, a more nuanced relationship is emerging.

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Multiple sulfatase deficiency (MSD, MIM #272200) results from pathogenic variants in the SUMF1 gene that impair proper function of the formylglycine-generating enzyme (FGE). FGE is essential for the posttranslational activation of cellular sulfatases. MSD patients display reduced or absent sulfatase activities and, as a result, clinical signs of single sulfatase disorders in a unique combination.

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Multiple sulfatase deficiency (MSD) is an ultrarare lysosomal storage disorder due to deficiency of all known sulfatases. MSD is caused by mutations in the Sulfatase Modifying Factor 1 (SUMF1) gene encoding the enzyme responsible for the post-translational modification and activation of all sulfatases. Most MSD patients carry hypomorph SUMF1 variants resulting in variable degrees of residual sulfatase activities.

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Background: Dental caries continue to be one among the major problems related to oral health in developing countries, that affects 60%-90% of school-aged children and adults. According to the WHO Global oral data bank in 2009 the point prevalence was 54% among 12 years old. Studies on prevalence conducted in Dakshina Kannada district reported a caries prevalence ranging from 32.

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Aim And Objective: To assess the application of clotrimazole (1%) as a complementary antifungal agent along with sodium hypochlorite (5.25%), chlorhexidine gluconate (2%), and doxycycline hydrochloride (5%) against .

Materials And Methods: Seventy freshly extracted single-rooted premolars with matured apices were collected, stored, and handled according to the Occupational Safety and Health Administration (OSHA) and the Center for Disease Control and Prevention (CDC) guidelines and recommendations.

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Aim And Objective: The aim of the study was to assess the efficacy of probiotic and green tea mouthrinse on salivary pH.

Materials And Methods: This study was conducted over a period of 1 month among 40 healthy schoolchildren aged between 6 and 8 years. The subjects who fulfilled inclusion criteria were selected and randomly divided into two groups, namely probiotic and green tea groups.

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Background: Eugenol released from zinc oxide eugenol (ZOE)-based sealants may cause irritation to the periapical tissues and has cytotoxic potential. Ozone therapy has numerous clinical applications with humans because of its bactericidal action, detoxifying effect, stimulation of angiogenesis, and wound-healing capacity. Therefore ozone can be incorporated in ZOE sealer to exploit these properties.

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Article Synopsis
  • Multiple sulfatase deficiency (MSD) is a rare neurodegenerative disorder linked to mutations in the SUMF1 gene, impacting sulfatase activation and leading to various sulfatase deficiencies.
  • The study analyzed 35 cases, focusing on the relationship between genetic variants and clinical outcomes, revealing that earlier symptom onset and severe genetic variants were associated with poorer neurological outcomes.
  • Findings highlighted differences between severe and attenuated cases, providing insights that could aid in prognosis and future research on MSD.
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Multiple sulfatase deficiency (MSD, MIM #272200) is an ultra-rare disease comprising pathophysiology and clinical features of mucopolysaccharidosis, sphingolipidosis and other sulfatase deficiencies. MSD is caused by impaired posttranslational activation of sulfatases through the formylglycine generating enzyme (FGE) encoded by the sulfatase modifying factor 1 () gene, which is mutated in MSD. FGE is a highly conserved, non-redundant ER protein that activates all cellular sulfatases by oxidizing a conserved cysteine in the active site of sulfatases that is necessary for full catalytic activity.

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Background: Multiple sulfatase deficiency (MSD, MIM #272200) is an ultrarare congenital disorder caused by SUMF1 mutation and often misdiagnosed due to its complex clinical presentation. Impeded by a lack of natural history, knowledge gained from individual case studies forms the source for a reliable diagnosis and consultation of patients and parents.

Methods: We collected clinical records as well as genetic and metabolic test results from two MSD patients.

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Multiple sulfatase deficiency (MSD) is a fatal, inherited lysosomal storage disorder characterized by reduced activities of all sulfatases in patients. Sulfatases require a unique post-translational modification of an active-site cysteine to formylglycine that is catalyzed by the formylglycine-generating enzyme (FGE). FGE mutations that affect intracellular protein stability determine residual enzyme activity and disease severity in MSD patients.

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Multiple sulfatase deficiency (MSD) is a rare inherited metabolic disease caused by defective cellular sulfatases. Activity of sulfatases depends on post-translational modification catalyzed by formylglycine-generating enzyme (FGE), encoded by the SUMF1 gene. SUMF1 pathologic variants cause MSD, a syndrome presenting with a complex phenotype.

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C α-formylglycine (FGly) is the catalytic residue of sulfatases in eukaryotes. It is generated by a unique post-translational modification catalysed by the FGly-generating enzyme (FGE) in the endoplasmic reticulum. FGE oxidizes a cysteine residue within the conserved CxPxR sequence motif of nascent sulfatase polypeptides to FGly.

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Here, we describe altered sorting of sortilin in adipocytes deficient for the σ1B-containing AP-1 complex, leading to the inhibition of adipogenesis. The AP-1 complex mediates protein sorting between the trans-Golgi network and endosomes. Vertebrates express three AP1 σ1 subunit isoforms - σ1A, σ1B and σ1C (also known as AP1S1, AP1S2 and AP1S3, respectively).

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The AP-1 complex recycles between membranes and the cytoplasm and dissociates from membranes during clathrin-coated-vesicle uncoating, but also independently of vesicular transport. The μ1A N-terminal 70 amino acids are involved in regulating AP-1 recycling. In a yeast two-hybrid library screen we identified the cytoplasmic prolyl-oligopeptidase-like protein PREPL as an interaction partner of this domain.

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Multiple sulfatase deficiency (MSD) is a rare inborn error of metabolism affecting posttranslational activation of sulfatases by the formylglycine generating enzyme (FGE). Due to mutations in the encoding SUMF1 gene, FGE's catalytic capacity is impaired resulting in reduced cellular sulfatase activities. Both, FGE protein stability and residual activity determine disease severity and have previously been correlated with the clinical MSD phenotype.

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Formylglycine-generating enzyme (FGE) post-translationally converts a specific cysteine in newly synthesized sulfatases to formylglycine (FGly). FGly is the key catalytic residue of the sulfatase family, comprising 17 nonredundant enzymes in human that play essential roles in development and homeostasis. FGE, a resident protein of the endoplasmic reticulum, is also secreted.

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Multiple Sulfatase Deficiency (MSD) is caused by mutations in the sulfatase-modifying factor 1 gene encoding the formylglycine-generating enzyme (FGE). FGE post translationally activates all newly synthesized sulfatases by generating the catalytic residue formylglycine. Impaired FGE function leads to reduced sulfatase activities.

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Multiple sulfatase deficiency (MSD), mucolipidosis (ML) II/III and Niemann-Pick type C1 (NPC1) disease are rare but fatal lysosomal storage disorders caused by the genetic defect of non-lysosomal proteins. The NPC1 protein mainly localizes to late endosomes and is essential for cholesterol redistribution from endocytosed LDL to cellular membranes. NPC1 deficiency leads to lysosomal accumulation of a broad range of lipids.

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Formylglycine-generating enzyme (FGE) catalyzes the oxidation of a specific cysteine residue in nascent sulfatase polypeptides to formylglycine (FGly). This FGly is part of the active site of all sulfatases and is required for their catalytic activity. Here we demonstrate that residues 34-68 constitute an N-terminal extension of the FGE catalytic core that is dispensable for in vitro enzymatic activity of FGE but is required for its in vivo activity in the endoplasmic reticulum (ER), i.

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Inside the endoplasmic reticulum (ER) formylglycine-generating enzyme (FGE) catalyzes in newly synthesized sulfatases the post-translational oxidation of a specific cysteine. Thereby formylglycine is generated, which is essential for sulfatase activity. Here we show that ERp44 interacts with FGE forming heterodimeric and, to a lesser extent, also heterotetrameric and octameric complexes, which are stabilized through disulfide bonding between cysteine 29 of ERp44 and cysteines 50 and 52 in the N-terminal region of FGE.

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The adaptor protein complex AP-1 mediates vesicular protein sorting between the trans Golgi network and endosomes. AP-1 recycles between membranes and the cytoplasm together with clathrin during transport vesicle formation and vesicle uncoating. AP-1 recycles independent of clathrin, indicating binding to unproductive membrane domains and premature termination of vesicle budding.

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A number of peptides and peptide analogs derived from the membrane proximal region of gp41 ectodomain are found to be effective inhibitors of human immunodeficiency virus type 1 (HIV-1)-mediated fusion events. One of them, T20 (aa 638-673), was found disordered and sparingly soluble in water, but became soluble upon mixing with selected, structured peptides from the amino terminal heptad repeat (HR1) region of gp41 using a simple and sensitive method of reduction in the scattering of T20 suspension. From the results on mapping the locus of interaction with T20 by employing partially overlapping peptides derived from HR1, it was concluded that the LLSGIV segment was a critical docking site for the C-terminal peptide of gp41 in its putative inhibitory action consistent with a previous fluorescence study.

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