Triamcinolone acetonide reduces viability, induces oxidative stress, and alters gene expressions of human chondrocytes.

OBJECTIVE: Patients with knee osteoarthritis (OA) are sometimes prescribed intra-articular injections of glucocorticoids (GCs), such as triamcinolone acetonide (TA). Whether GCs cause chondrotoxicity is not known. We wished to ascertain if TA induces toxicity by causing oxidative stress and alters expression of P21, growth differentiation factor (GDF)15, and cFos. PATIENTS AND METHODS: Primary chondrocytes isolated from 10 OA patients undergoing total knee replacement surgery were incubated with TA (0, 1, 5, 10 mg/ml), with or without 100 µM vitamin C for 7 and 14 days for viability assays and 48 h for oxidative stress and gene expression analyses. RESULTS: TA significantly decreased chondrocyte viability and increased the ratio of oxidized glutathione to total glutathione suggesting an increase in oxidative stress. Vitamin C significantly increased the viability and decreased the oxidative stress of cells treated with 5 mg/ml TA. Expression of P21, GDF15, and cFos increased significantly when TA was added (5.17 ± 2.4-, 4.96 ± 3.1-fold for P21, 9.97 ± 2.9- and 4.2 ± 1.6-fold for GDF15, and 6.65 ± 4.8-, 12.96 ± 8.3-fold for cFos at 1, and 5 mg/ml TA, respectively). CONCLUSIONS: TA induced chondrotoxicity by increasing oxidative stress and altering expressions of genes involved in cell death. The addition of vitamin C decreased oxidative stress and increased viability, suggesting that antioxidants might attenuate TA toxicity in cartilage.

Glucocorticoid receptor gene (NR3C1) promoter is hypermethylated in Thai females with major depressive disorder.

Major depressive disorder (MDD) has been associated with the stress response in the brain, which is controlled by the hypothalamic-pituitary-adrenal (HPA) axis. This HPA negative feedback mechanism acts via the activation of glucocorticoid receptor, which is encoded by the NR3C1 gene. The methylation status at the promoter of NR3C1 has been correlated with traumatic experiences in early life, which develop into mental disorder. The aim of this study was to examine the potential associations between the methylation status of NR3C1 promoter, gene expression, blood plasma cortisol levels, and adulthood MDD. The study was conducted with 29 MDD patients (9 males, 20 females) and 33 normal individuals (7 males, 26 females). Bisulfite pyrosequencing on 7 CpG dinucleotides in the region showed significantly higher methylation levels at the CpG7 in MDD patients. When separated by gender, the methylation levels differed significantly in females, but not in males. No significant differences between NR3C1 gene expression level and plasma cortisol levels of MDD patients and normal controls were observed. These data suggest that higher levels of methylation at the NR3C1 promoter may be associated with MDD in a gender-specific manner.

ADAMTS14 gene polymorphism associated with knee osteoarthritis in Thai women.

Osteoarthritis (OA) is the most prevalent form of arthritis in the elderly. This disease is characterized by breakdown and loss of articular cartilage due to genetic, mechanical and environmental factors. Although the pathophysiology of OA is not completely known, several candidate genes have been reported to be associated with OA susceptibility. We assessed the association between genetic variation in the ADAMTS14 region and knee osteoarthritis susceptibility in the Thai population. The rs4747096 SNP was genotyped by PCR-RFLP on genomic DNA extracted from peripheral blood of 108 OA patients and 119 controls. The PCR product (196 bp) was digested with BspEI. A sample with the GG genotype showed two band sizes of 158 and 38 bp, while a sample with the AA genotype showed a single band size of 196 bp. Heterozygotes with the AG genotype showed all three corresponding bands. Genotype distributions, allele frequencies and model of inheritance in patients and controls were compared. In females, the frequency of the AA genotype and the A allele were significantly higher in knee OA patients than in controls [odds ratio (OR) = 2.79, 95% confidence interval (CI) = 1.05-7.59 and OR = 1.58, 95%CI = 1.00-2.45, respectively]. Moreover, genotypic AA and AG were associated with significantly increased risk for knee OA when compared to GG (OR = 2.72, 95%CI = 1.10-6.87). No significant associations were observed in males. In conclusion, the nsSNP rs4747096 in ADAMTS14 was associated with knee OA in female Thai patients; therefore, the role of ADAMTS14 in OA seems to be gender-dependent.

Holocarboxylase synthetase deficiency: novel clinical and molecular findings.

Multiple carboxylase deficiency (MCD) is an autosomal recessive metabolic disorder caused by defective activity of biotinidase or holocarboxylase synthetase (HLCS) in the biotin cycle. Clinical symptoms include skin lesions and severe metabolic acidosis. Here, we reported four unrelated Thai patients with MCD, diagnosed by urine organic acid analysis. Unlike Caucasians, which biotinidase deficiency has been found to be more common, all of our four Thai patients were affected by HLCS deficiency. Instead of the generally recommended high dose of biotin, our patients were given biotin at 1.2 mg/day. This low-dose biotin significantly improved their clinical symptoms and stabilized the metabolic state on long-term follow-up. Mutation analysis by polymerase chain reaction-sequencing of the entire coding region of the HLCS gene revealed the c.1522C>T (p.R508W) mutation in six of the eight mutant alleles. This suggests it as the most common mutation in the Thai population, which paves the way for a rapid and unsophisticated diagnostic method for the ethnic Thai. Haplotype analysis revealed that the c.1522C>T was on three different haplotypes suggesting that it was recurrent, not caused by a founder effect. In addition, a novel mutation, c.1513G>C (p.G505R), was identified, expanding the mutational spectrum of this gene.

Prenatal diagnosis of a novel mutation, c.529C>T (p.Q177X), in the BCKDHA gene in a family with maple syrup urine disease.

Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder caused by defective activity of the branched-chain alpha-keto-acid dehydrogenase (BCKD) complex. The disease-causing mutations can affect the BCKDHA, BCKDHB or DBT genes encoding for the E1a, E1b, and E2 subunits, respectively, of the BCKD complex. Here we report a girl who first presented to our clinic at 4 years of age with profound mental retardation. A diagnosis of MSUD was subsequently made based on the results of plasma amino acid analysis. Mutation analysis confirmed that she was homozygous for a novel mutation, c.529C>T (p.Q177X) in BCKDHA, while both parents, who were first cousins, were heterozygous. This enabled us to give an option of prenatal diagnosis to the parents. The prenatal testing for MSUD was performed during the mother's subsequent pregnancy and revealed that the fetus was heterozygous for the mutation. The healthy male neonate was born and his genotype was tested by restriction enzyme analysis, which confirmed the result of the prenatal testing. In summary, a late diagnosis of MSUD in patients without an unusual odour could occur especially in countries without neonatal screening programs as seen in the index patient. Mutation detection was, however, still beneficial to the family since prenatal testing could be performed in subsequent pregnancies. In addition, a novel mutation was found, expanding the mutation spectrum of this disease.