Distribution of genetic polymorphisms of serum amyloid protein A1 in healthy Chinese Han and Uighur populations in Xinjiang / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic polymorphisms of rs2229338 and rs12218 loci of serum amyloid protein A1 (SAA1) gene in healthy Chinese Han and Uighur populations of Xinjiang.</p><p><b>METHODS</b>The genotypes of the SAA1 gene were detected in 316 Uighur and 362 Han healthy individuals by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).</p><p><b>RESULTS</b>The genotype distributions of both populations were in the Hardy-Weinberg equilibrium (both P>0.05). The frequencies of AA, AG and GG genotypes of the rs2229338 locus were 76.6%, 23.4%, and 0 in the Uighurs, and 91.7%, 7.7% and 0.6% in the Hans. There was significant difference in distribution of genotypes between the two populations (P<0.01). The frequencies of CC, CT and TT genotypes of the rs12218 locus were 10.1%, 47.5%, and 42.4% in Uighurs, and 3.3%, 34.3% and 62.4% in Hans. There was also significant difference in distribution of genotypes between the two populations (P<0.01). The A-C and G-T haplotypes were more frequent in the Uighur but the A-T haplotype was more common in the Han population, respectively (both P<0.01).</p><p><b>CONCLUSION</b>The mutational frequencies of the tagging SNPs in rs2229338 and rs12218 loci of theSAA1 gene in the Uighurs may be higher than those in Hans.</p>

Neuroprotective effects of alpha7 neuronal acetylcholine receptor and its roles in the pathogenesis of Alzheimer's disease / 中华病理学杂志

<p><b>OBJECTIVES</b>To investigate the neuroprotective function of alpha7 nicotinic receptor (nAChR) and its roles in the pathogenesis of Alzheimer's disease (AD).</p><p><b>METHOD</b>Specific RNA interference to alpha7 nAChR mRNA expression was performed by gene specific small interference RNA (siRNA). SH-SY5Y cells were transfected with the siRNA or treated with 20 micromol/L 3-[2, 4-dimethoxybenzylidene] anabaseine (DMXB), an alpha7 nAChR agonist. After 48 hrs culture, levels of alpha7 nAChR mRNA and protein were monitored by RT-PCR and Western blotting, respectively. In the second experiment, SH-SYSY cells treated with siRNA or DMXB were exposed to 1 micromol/L Abeta(25-35), followed by protein analysis of alpha-form of secreted beta-amyloid precursor peptide (alphaAPPs), and total APP was assayed by Western blotting. In addition, lipid peroxidation and MTT [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] reduction were measured by spectrophotometry.</p><p><b>RESULT</b>In RNA interference group, as compared with controls, alpha7 nAChR mRNA and protein levels were decreased with inhibitory efficiency by 80% and 69%, respectively, along with a decrease in protein levels of alphaAPP and reduction of MTT. However the product of lipid peroxidation was increased. There was an enhanced gene inhibition of alpha7 nAChR by Abeta. While cells treated with DMXB, the alpha7 nAChR protein was increased by 23% as compared with that of the control, along with decrease of alphaAPP and ERK 1/2 at the protein level. The enhanced expression of alpha7 nAChR reduced the neurotoxic effects resulted from Abeta.</p><p><b>CONCLUSION</b>The findings indicate that alpha7 nAChR may play a significant neuroprotective role by enhancing cleavage of APP, improving antioxidant defenses and limiting the toxicity of Abeta, which has been implied in the pathogenesis of AD.</p>