Zinc transporter mRNA levels in Alzheimer's disease postmortem brain.

Zinc (Zn2+) is concentrated into pre-synaptic vesicles and co-released with neurotransmitter at some synapses. Zn2+ can accelerate assembly of the amyloid-ß peptides (Aß) and tau protein central to the neuropathological changes found in Alzheimer's disease (AD). Altered protein levels of the membrane Zn2+ transporters ZnT1, ZnT4, and ZnT6 have been reported in AD postmortem brain tissue. The present study analyzed mRNA levels of five established (LIV1, ZIP1, ZnT1, ZnT4, and ZnT6) and one potential (PRNP) Zn2+ transporter in human postmortem brain tissue from Braak-staged individuals with AD and controls using quantitative real-time PCR. Four cortical regions (middle temporal gyrus, superior occipital gyrus, superior parietal gyrus, and superior frontal gyrus) and cerebellum were examined. PRNP mRNA levels were decreased by ∼30% in all four cortical regions examined in AD patients, but unchanged in the cerebellum. In contrast, some increases in mRNA levels of the other more established Zn2+ transporters (LIV1, ZIP1, ZnT1, ZnT6) were found in AD cortex. The ratios of the mRNA levels of LIV1, ZIP1, ZnT1, ZnT4, and ZnT6/mRNA level of neuron specific enolase increased significantly as the disease progressed and Braak stage increased. Significant correlations were also identified between mRNA levels of several of the Zn2+ transporters investigated. These expression changes could either reflect or cause the altered cortical Zn2+ distribution in AD, potentially increasing the likelihood of interactions between Zn2+ and Aß or tau protein.

Association of functional haem oxygenase-1 gene promoter polymorphism with polycystic kidney disease and IgA nephropathy.

BACKGROUND: Haem oxygenase-1 (HO-1) is a cytoprotective molecule that is reported to have a protective role in a variety of experimental models of renal injury. A functional dinucleotide repeat (GT)(n) polymorphism, within the HO-1 promoter, regulates HO-1 gene expression; a short number of repeats (S-allele <25) increases transcription. We report the first assessment of the role of this HO-1 gene promoter polymorphism in chronic kidney disease due to autosomal dominant polycystic kidney disease (ADPKD) and IgA nephropathy (IgAN). METHODS: The DNA from 160 patients (99% Caucasian) on renal replacement therapy (RRT) was genotyped. The primary renal disease was ADPKD in 100 patients and biopsy-proven IgAN in 60 patients. RESULTS: Overall, the mean age at commencement of RRT was not significantly different between patients with and without an S-allele (44.1 years versus 45.0 years, P = 0.64). In patients with ADPKD, the age at commencement of RRT was comparable regardless of the HO-1 genotype (47.7 years versus 46.7 years, P = 0.59). The same was true in patients with IgAN (38.3 years versus 42.2 years, P = 0.28). CONCLUSION: This suggests that the functional HO-1 promoter polymorphism does not influence renal survival in CKD due to ADPKD or IgAN.

CTLA4 gene polymorphisms and multiple sclerosis in Northern Ireland.

Four CTLA4 polymorphisms were investigated in a Northern Irish collection of relapsing-remitting (RR) and primary-progressive (PP) multiple sclerosis (MS) patients. The CTLA4 promoter (-318 C/T), exon 1 (+49 A/G) and intergenic CT60 SNPs, as well as a microsatellite found in the 3' UTR (AT(n)) were analysed in 246 RRMS, 84 PPMS and 158 healthy controls. The A allele of the exon 1 +49 A/G SNP (OR=1.36; 95% CI=1.11-1.81; P=0.038), and more so the AA genotype (OR=1.70; 95% CI=1.11-2.60; P=0.015) were associated with RR, but not PPMS. In the PPMS population, overall allele distribution of the AT(n) microsatellite was significantly different from that in the healthy controls. We did not find any association with the promoter (-318 C/T) or intergenic CT60 SNPs in either of the disease cohorts. In concordance with several recent studies, we detected a trend toward higher carriage rates of the +49 G allele in PP vs RR MS patients (66.7% vs 58.9%), though this was not significant. Our data highlight the CTLA4 +49 A/G and 3'UTR polymorphisms as potential modifiers of disease course in MS.

Study of polymorphisms in the interleukin-4 and IL-4 receptor genes in a population of Brazilian patients with multiple sclerosis

This study aimed to investigate in a population of Brazilian patients with multiple sclerosis (MS) single-nucleotide polymorphisms (SNP) in the promoter region of IL4 (*33C-T) and receptor IL4R (*Q551R A-G) genes proposed to interfere with disease progression. No significant differences were observed in either of the SNPs investigated between healthy controls (n=135) and MS patients (n=129). However, the IL4+33 TT genotype was significantly (p=0.039) higher in African descendants MS (AF-MS= 9.09 percent) than in Caucasian MS (CA-MS= 1.35 percent). It was also observed a significant (p=0.016) increase for the IL4R* Q551R CC genotype in AF-MS compared to those of Caucasian ethnicity (AF-MS= 21.62 percent; CA-MS= 4.35 percent). These results suggest that IL4+33 and IL4R*Q551 polymorphisms may have a disease-promoting role of TH2 mediators in African MS descendants. Additionally neither IL4 nor IL4R genes are susceptibility factors for Brazilian MS but may be able to modify ethnicity-dependent disease risk and penetrance of susceptibility factors.

Este é um estudo inédito realizado numa população brasileira de pacientes portadores de esclerose múltipla (EM) visando determinar uma possível associação na expressão de polimorfismo (SNP) nos genes da citocina reguladora IL4 (*33C-T) e do seu respectivo receptor IL4R (*Q551R A-G) capazes de modificar a evolução da doença. Não foi observada diferença significativa em ambos SNPs analisados entre o grupo controle de indivíduos saudáveis (n=135) e os pacientes com EM (n=129). Contudo, o genotipo IL4+33 TT apresentava percentual mais elevado (9,09 por cento) nos pacientes EM com descendência africana (AF-EM) do que nos descendentes caucasianos (CA-EM=1,35 por cento) sendo esta diferença significativa (p=0,039). Também foi observado um aumento significativo (p=0,016) para o genotipo IL4R* Q551R CC nos pacientes AF-EM (21,62 por cento) comparando-se com CA-EM (4,35 por cento). Estes resultados indicam que polimorfismos nos genes da citocina IL4 (*33C-T) e respectivo receptor IL4R (*Q551R A-G) influenciam na produção de citocinas do tipo TH2 e evolução da doença nos pacientes EM com descendência africana. Embora polimorfismo nos genes IL4 (*33C-T) e respectivo receptor IL4R (*Q551R A-G) não sejam fatores indutores de susceptibilidade para EM podem modificar o risco e evolução da EM numa população com alto grau de miscigenação étnica.