An exceptionally long CA-repeat in the core promoter of SCGB2B2 links with the evolution of apes and Old World monkeys.

We have recently reported a genome-scale catalog of human protein-coding genes that contain "exceptionally long" STRs (≥6-repeats) in their core promoter, which may be of selective advantage in this species. At the top of that list, SCGB2B2 (also known as SCGBL), contains one of the longest CA-repeat STRs identified in a human gene core promoter, at 25-repeats. In the study reported here, we analyzed the conservation status of this CA-STR across evolution. The functional implication of this STR to alter gene expression activity was also analyzed in the HEK-293 cell line. We report that the SCGB2B2 core promoter CA-repeat reaches exceptional lengths, ranging from 9- to 25-repeats, across Apes (Hominoids) and the Old World monkeys (CA>2-repeats were not detected in any other species). The longest CA-repeats and highest identity in the SCGB2B2 protein sequence were observed between human and bonobo. A trend for increased gene expression activity was observed from the shorter to the longer CA-repeats (p<0.009), and the CA-repeat increased gene expression activity, per se (p<0.02). We propose that the SCGB2B2 gene core promoter CA-repeat functions as an expression code for the evolution of Apes and the Old World monkeys.

Dominant and Protective Role of the CYTH4 Primate-Specific GTTT-Repeat Longer Alleles Against Neurodegeneration.

Primate-specific genes and regulatory mechanisms could provide insight into human brain functioning and disease. In a genome-scale analysis of the entire protein-coding genes listed in the GeneCards database, we have recently reported human genes that contain "exceptionally long" short tandem repeats (STRs) in their core promoter, which may be of adaptive/selective evolutionary advantage in this species. The longest tetra-nucleotide repeat identified in a human gene core promoter belongs to the CYTH4 gene. This GTTT-repeat is specific to Hominidae and Old World monkeys, and the shortest allele of this repeat, (GTTT)6, is linked with neural dysfunction and type I bipolar disorder in human. In the present study, we sought a possibly broader role for the CYTH4 gene core promoter GTTT-repeat in neural functioning and investigated its allelic distribution in a total of 949 human subjects, consisting of two neurodegenerative disorders, multiple sclerosis (MS) (n = 272) and Alzheimer's disease (AD) (n = 257), and controls (n = 420). The range of the alleles of this GTTT-repeat in the human sample studied was between 6- and 9-repeats. The shortest allele, (GTTT)6, was significantly in excess in the MS and AD patients in comparison with the controls (p < 0.004). The 6/6, 6/7, and 7/7 genotypes were in excess in the MS and AD patients, whereas the overall frequency of all other genotypes (consisting of at least one longer allele, i.e., 8- or 9-repeat) was higher in the controls (p < 0.005), indicating a dominant and protective effect for the longer alleles against neurodegeneration. This is the first indication of the involvement of a primate-specific STR in neurodegeneration in humans. We propose an adaptive evolutionary role for the expansion of the CYTH4 gene core promoter GTTT-repeat in the human brain, which is supported by a link between the shortest allele of this repeat with neuropsychiatric disorders.

A primate-specific functional GTTT-repeat in the core promoter of CYTH4 is linked to bipolar disorder in human.

Evidence of primate-specific genes and gene regulatory mechanisms linked to bipolar disorder (BD) lend support to evolutionary/adaptive processes in the pathogenesis of this disorder. Following a genome-scale analysis of the entire protein coding genes annotated in the GeneCards database, we have recently reported that cytohesin-4 (CYTH4) contains the longest tetra-nucleotide short tandem repeat (STR) identified in a human protein-coding gene core promoter, which may be of adaptive advantage to this species. In the current study, we analyzed the evolutionary trend of this STR across evolution. We also analyzed the functional implication and distribution of this STR in a group of patients with type 1 BD (n=233) and controls (n=262). We found that this STR is exceptionally expanded in primates (Fisher exact p<0.00003). Association was observed between type I BD and the 6-repeat allele of this STR, (GTTT)6 (Yates corrected Χ(2)=12.68, p<0.0001, OR: 1.68). This allele is the shortest length of the GTTT-repeat identified in the human subjects studied. Consistent with that finding, excess homozygosity was observed for the shorter alleles, (GTTT)6 and (GTTT)7, vs. the longer alleles, (GTTT)8 and (GTTT)9 in the BD group (Yates corrected Χ(2)=5.18, p<0.01, 1 df, OR: 1.96). Using Dual Glo luciferase system in HEK-293 cells, a trend for gene expression repression was observed from the 6- to the 9-repeat allele (p<0.003), and the GTTT-repeat significantly down-regulated gene expression, per se (p<0.0006). This is the first evidence of a link between a primate-specific STR and a major psychiatric disorder in human. It may be speculated that the CYTH4 GTTT-repeat in primates may have conferred selective advantage to this order, reflected in neural function and neurophenotypes. The role of the CYTH4 gene in the pathogenesis of type I BD remains to be clarified in the future studies.

Novel evidence of the involvement of calreticulin in major psychiatric disorders.

Calreticulin (CALR) is a multi-functional protein that is strictly conserved across species. Two mRNA transcripts have been recognized for the CALR gene in humans, which use a common promoter sequence. We have recently reported mutations in the CALR promoter that co-occur with psychosis. One of those mutations at -220A increases gene expression in human BE(2)-C and HEK-293 cell lines. This mutation is the first instance of a functional cognition-deficit mutation reversing a human gene promoter to the primitive type. In the current study, we analyzed the effect of the most widely-used mood-stabilizing drug, valproic acid (VPA), on nucleotide -220 in two neuronal cell lines, LAN-5 and N2A. Remarkably, VPA increased gene expression in the cells with the wild-type -220C construct, whereas a dramatic decrease in gene expression was observed in the cell lines with the mutant construct (p<0.000004 and p<0.016, respectively). We also sequenced the 600-bp CALR promoter, and the highly conserved intron 1 sequence in an independent sample of patients afflicted with major psychiatric disorders and controls. A new case of major depressive disorder with psychotic features with the -220A mutation was identified. A novel 1-bp insertion was also detected in intron 1 at IVSI-310, in a case of amphetamine-induced psychosis. As for the psychosis-linked CALR promoter mutations identified to-date, the IVSI mutation was not detected in the control pool. This mutation creates a RREB-1 transcription factor binding site within the first intron. Our present findings identify the site of action of VPA in the CALR promoter, and introduce a novel mutation in a case of substance-induced psychosis in the first intron of CALR.

Polymorphism in the promoter region of the CD14 gene and susceptibility to Brucellosis.

A single-nucleotide polymorphism in the promoter region of the CD14 gene at position 159 has been implicated in susceptibility to infectious diseases. We sought to determine the association between CD14 C-159 T functional promoter polymorphism and brucellosis in Western Iranian population where the disease is endemic. The CD14 genotype was determined in 228 patients with brucellosis from a rural area and 129 healthy volunteers from the same area. The prevalence of genotype TT was significantly higher in the patients while the controls showed higher prevalence of genotype CC (34.5% vs 15.5%, 15.4% vs 25.6%, P = 0.009). Multiple logistic regression analysis after adjustment for gender demonstrated that the patients who were homozygous for allele T of promoter of CD14 gene had a significantly higher risk for developing brucellosis with odds ratio of 3.03 (95% CI, 5.2, 1.75 P = 0.0004). The existence of homozygous genotype of allele T of CD14 was an independent determinant for occurrence of arthritis among the patients with brucellosis (odds ratio of 3.92 (95% CI, 2.93, 5.88, P = 0.001).Our findings provide suggestive evidence of association of the CD14 gene polymorphism with susceptibility to development of brucellosis in Iranian populations.

TLR4 polymorphism in Iranian patients with brucellosis.

OBJECTIVE: Brucellosis is a zoonosis of both public health and economic significance in most developing countries. Polymorphisms in Toll-like receptor-4 (TLR4) have been reported to be associated with a blunted immune response to microbial pathogens. Information regarding any association between genetic variation of TLR4 and susceptibility to brucellosis is not available in the literatures. The main purpose of this research is to evaluate the role of polymorphic alleles of TLR4 gene in susceptibility to brucellosis. MATERIALS AND METHODS: In this case-control study, 198 patients with brucellosis and 111 healthy volunteers matched for sex, age and geographic area were evaluated by genotyping for polymorphism in TLR4 gene (Asp299Gly) using amplification refractory mutation system (ARMS)-PCR method. RESULTS: Allele 896G was more prevalent in patients with brucellosis compared to healthy controls (33.6% vs. 20.7%, P=0.000003). Also the frequency of G allele of TLR4 gene was significantly higher in male patients with brucellosis compared to the same sex in control group (36% vs. 21.7%, P=0.00005). Multiple logistic regression analysis demonstrated that male patients heterozygous at allele G gene had a significantly higher risk for brucellosis with an odds ratio of OR 2.89, 95% CI: 1.79-4.69, P<0.0001). CONCLUSION: This study is the first to show an association between genetic polymorphism in TLR4 gene and susceptibility to brucellosis.

Multichannel physiological monitor plus simultaneous full-duplex speech channel using a dial-up telephone line.

Because of bandwidth limitations, the Public Switched Telephone Network (PSTN) cannot normally accommodate simultaneous multichannel physiological signaling with speech. This communication describes work carried out to build a physiological monitoring system which can transmit up to six low-frequency data channels in the presence of a full-duplex speech channel using one telephone line.