• Journal of Life Science
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• v.14 no.2
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• pp.315-319
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• 2004

For antibody development of human serine palmitoyltransferase (SPT, EC 2.3.1.50), SPTLC1 and SPTLC2 genes were subcloned in pRset vector and expressed in E. coli BL21 (DE3)pLys cells. Eucaryotic SPT is a membrane-bound heterodimer enzyme, while all other members are soluble homodimer enzymes. cDNA library were obtained from total RNA from human embryo kidney cell line, HEK293, using RT-PCR and PCR with specific primers was carried out for preparing SPTLC1 and SPTLC2 genes. pRset vector which can express hexahistidine-tag fusion protein was used and the DNA sequences of pRsetB/SPTLC1 and pRsetA/SPTLC2 were confirmed. Recombinant BL21 cells with SPTLC subunits were selected with LB plate containing ampicillin and chroramphenicol. SPTLC1 and SPTLC2 proteins were induced with 1 mM IPTG and seperated on 10% SDS-PAGE gel. Expressed proteins were confirmed by western blotting with His-tag antibody.

• BMB Reports
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• v.50 no.3
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• pp.144-149
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• 2017

Ceramides are the major sphingolipid metabolites involved in cell survival and apoptosis. When HepG2 hepatoma cells were treated with celecoxib, the expression of the genes in de novo sphingolipid biosynthesis and sphingomyelinase pathway was upregulated and cellular ceramide was elevated. In addition, celecoxib induced endoplasmic reticulum (ER) stress in a time-dependent manner. SPTLC2, a subunit of serine palmitoyltransferase, was overexpressed by adenovirus. Adenoviral overexpression of SPTLC2 (AdSPTLC2) decreased cell viability of HEK293 and HepG2 cells. In addition, AdSPTLC2 induced apoptosis via the caspase-dependent apoptotic pathway and elevated cellular ceramide, sphingoid bases, and dihydroceramide. However, overexpression of SPTLC2 did not induce ER stress. Collectively, celecoxib activates de novo sphingolipid biosynthesis and the combined effects of elevated ceramide and transcriptional activation of ER stress induce apoptosis. However, activation of de novo sphingolipid biosynthesis does not activate ER stress in hepatoma cells and is distinct from the celecoxib-mediated activation of ER stress.

• Molecules and Cells
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• v.39 no.5
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• pp.382-388
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• 2016

Inherited peripheral neuropathies (IPN), which are a group of clinically and genetically heterogeneous peripheral nerve disorders including Charcot-Marie-Tooth disease (CMT), exhibit progressive degeneration of muscles in the extremities and loss of sensory function. Over 70 genes have been reported as genetic causatives and the number is still growing. We prepared a targeted gene panel for IPN diagnosis based on next generation sequencing (NGS). The gene panel was designed to detect mutations in 73 genes reported to be genetic causes of IPN or related peripheral neuropathies, and to detect duplication of the chromosome 17p12 region, the major genetic cause of CMT1A. We applied the gene panel to 115 samples from 63 non-CMT1A families, and isolated 15 pathogenic or likelypathogenic mutations in eight genes from 25 patients (17 families). Of them, eight mutations were unreported variants. Of particular interest, this study revealed several very rare mutations in the SPTLC2, DCTN1, and MARS genes. In addition, the effectiveness of the detection of CMT1A was confirmed by comparing five 17p12-nonduplicated controls and 15 CMT1A cases. In conclusion, we developed a gene panel for one step genetic diagnosis of IPN. It seems that its time- and cost-effectiveness are superior to previous tiered-genetic diagnosis algorithms, and it could be applied as a genetic diagnostic system for inherited peripheral neuropathies.