Ameliorative effect and mechanism of Yi-Suan-Cha against hyperuricemia in rats.

BACKGROUND: This study aimed to evaluate the urate-lowering effects of Yi-Suan-Cha and explore its underlying mechanisms in experimental hyperuricemia induced in rats. METHODS: Forty-eight male SD rats were randomly allocated into normal control, model, allopurinol, benzbromarone, low-dose Yi-Suan-Cha (0.2 g/ml), and high-dose Yi-Suan-Cha (0.4 g/ml) groups (n = 8 rats per group). Rat models of hyperuricemia were established through intragastric administration of adenine 25 mg/kg + potassium oxalate 300 mg/kg for 3 weeks. After the last administration, serum uric acid, creatinine, and urea nitrogen levels were measured. Renal histopathology was observed by hematoxylin-eosin staining. Xanthine oxidase level in serum and liver homogenates was measured by ELISA. The protein and mRNA expression of URAT1, ABCG2, OAT1, and GLUT9 in the kidney was detected by Western blotting and RT-PCR, respectively. RESULTS: The serum uric acid levels were significantly lowered in all medication groups than in the model group. The benzbromarone and both Yi-Suan-Cha groups showed clear kidney structures with no obvious abnormalities. Compared with the normal control group, the model group showed increased URAT1/GLUT9 protein expression and decreased ABCG2/OAT1 protein expression. Compared with the model group, both Yi-Suan-Cha groups showed decreased URAT1/GLUT9 protein expression and increased ABCG2/OAT1 protein expression. Compared with that in the normal control group, URAT1/GLUT9 mRNA expression increased in the model group. Compared with the model group, the low-dose and high-dose Yi-Suan-Cha groups showed decreased URAT1/GLUT9 mRNA expression and increased ABCG2/OAT1 mRNA expression. CONCLUSION: Yi-Suan-Cha may lower uric acid level by downregulating URAT1/GLUT9 expression and upregulating ABCG2/OAT1 expression.

A Novel Mutation of SLC19A2 in a Chinese Zhuang Ethnic Family with Thiamine-Responsive Megaloblastic Anemia.

BACKGROUND/AIMS: Thiamine-responsive megaloblastic anemia syndrome is a rare autosomal recessive disorder resulting from mutations in SLC19A2, and is mainly characterized by megaloblastic anemia, diabetes, and progressive sensorineural hearing loss. METHODS: We study a Chinese Zhuang ethnicity family with thiamine-responsive megaloblastic anemia. The proband of the study presented with anemia and diabetes, similar to his late brother, as well as visual impairment. All clinical manifestations were corrected with thiamine (30 mg/d) supplementation for 1-3 months, except for visual impairment, which was irreversible. The presence of mutations in all exons and the flanking sequences of the SLC19A2 gene were analyzed in this family based on the proband's and his brother's clinical data. Computer analysis and prediction of the protein conformation of mutant THTR-1. The relative concentration of thiamine pyrophosphate in the proband's whole blood before and after initiation of thiamine supplement was measured by high performance liquid chromatography (HPLC). RESULTS: Gene sequencing showed a homozygous mutation in exon 6 of the SLC19A2 gene (c.1409insT) in the proband. His parents and sister were diagnosed as heterozygous carriers of the c.1409insT mutation. Computer simulation showed that the mutations caused a change in protein conformation. HPLC results suggested that the relative concentration of thiamine pyrophosphate in the proband's whole blood after thiamine supplement was significantly different (P=0.016) from that at baseline. CONCLUSIONS: This novel homozygous mutation (c.1409insT) caused the onset of thiamine-responsive megaloblastic anemia in the proband.

A novel lectin from Artocarpus lingnanensis induces proliferation and Th1/Th2 cytokine secretion through CD45 signaling pathway in human T lymphocytes.

Lectins are carbohydrate-binding proteins and have been used for purification and characterization of glycoproteins. In this study, a novel 58.9-kDa tetrameric lectin from Artocarpus lingnanensis seeds was purified, characterized, and its mitogenic potential was evaluated. The hemagglutination inhibition assay indicated that Artocarpus lingnanensis lectin (ALL) showed specificity toward galactose. ALL was effectively purified in a single-step using affinity chromatography on a galactose-Sepharose column. ALL showed pH optima between 5.0 and 9.0, and optimal temperature between 20 and 40 °C. ALL triggered proliferation and activation of human T lymphocytes (e.g., CD4+ T lymphocytes). Flow cytometry and laser scanning confocal microscopy revealed binding of ALL to T cells and colocalized with CD45. Affinity chromatography and Western blot suggested that CD45 isolated from human T cell membrane fraction may be the major receptor of ALL. CD45 blocking antibody attenuated the binding and proliferation of T cells induced by ALL. CD45-PTPase inhibitor dephostatin reduced ALL-induced T cells proliferation and expression of CD25 and pZAP-70. Furthermore, secretion of ALL-induced Th1/Th2 cytokines was blocked with dephostatin. Also, dephostatin inhibited phosphorylation of ALL-mediated activation of ERK and p38MAPK. This study demonstrates the involvement of CD45-mediated signaling in ALL-induced T lymphocyte proliferation and Th1/Th2 cytokine secretion through activation of p38 and ERK.