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.

Evaluating of suppressor of zeste 12 and chromobox homolog 8 genes expression showed two possible origins for gastric cancer development.

CONTEXT: Changes in genome, made by multiple genetic and epigenetic alterations result to the cancer initiation and progression. Suppressor of zeste 12 (SUZ12) and chromobox homolog 8 (CBX8) proteins are two components of epigenetic regulators that their function in the initiation and progression of cancers are not well-understood. AIMS: The role of SUZ12 and its target CBX8 is examined. SETTINGS AND DESIGN: Comparing the expression levels of SUZ12 and CBX8 between 30 gastric tumor and their marginal tissues. MATERIALS AND METHODS: Quantitative reverse transcription polymerase chain reaction technique was performed. STATISTICAL ANALYSIS: Statistical comparison was carried out using Statistical Program for Social Sciences software 16.0 (Released 2007, SPSS for Windows. SPSS Inc., Chicago, IL, USA) and (GraphPad Prism version 5 for Windows, GraphPad Software, La Jolla, California USA, ww.graphpad.com). RESULTS: Despite the obvious differences in the expression of these genes in each sample for tumor and its marginal tissue, statistical analysis did not show significant differences in the mean of expression for SUZ12 and CBX8 genes in total. Due to the variation in expression levels, the samples could be divided into two groups for each gene; group 1, in which the genes were overexpressed in tumor and group 2, in which the genes were down regulated in tumor samples. CONCLUSION: We found that in each group, the difference in the SUZ12 and CBX8 genes expression were significantly divergent between tumors and their marginal tissues. It means that the regulatory mechanisms involved in developing and controlling the process of gastric cancer pathogenesis is more complex than it thought. These results also bring new evidence on the possible double origin for gastric cancer development, bone-marrow-derived cells and tissue stem cells.

Generation and analysis of bacteriorhodopsin mutants with the potential for biotechnological applications.

The properties of bacteriorhodopsin (BR) can be manipulated by genetic engineering. Therefore, by the methods of gene engineering, Asp85 was replaced individually by two other amino acids (D85V, D85S). The resulting recombinant proteins were assembled into soybean vesicles retinylated to form functional BR-like nano-particles. Proton translocation was almost completely abrogated by the mutant D85S, while the D85V mutant was partially active in pumping protons. Compared with wild type, maximum absorption of the mutants, D85V and D85S, were 563 and 609 nm, which illustrated 5 nm reductions (blue shift) and 41 nm increases (red shift), respectively. Since proton transport activity and spectroscopic activities of the mutants are different, a wide variety of membrane bioreactors (MBr) have been developed. Modified proteins can be utilized to produce unique photo/Electro-chromic materials and tools.

Potential applications of bacteriorhodopsin mutants.

Bacteriorhodopsin (BR), a model system in biotechnology, is a G-protein dependent trans membrane protein which serves as a light driven proton pump in the cell membrane of Halobacterium salinarum. Due to the linkage of retinal to the protein, it seems colored and has numbers of versatile properties. As in vitro culture of the Halobacteria is very difficult, and isolation is time consuming and usually inefficient, production of genetically modified constructs of the protein is essential. There are three important characteristics based on protein catalytic cycle and molecular functions of photo-electric, photochromic and proton transporting, which makes this protein as a strategic molecule with potential applications in biotechnology. Such applications include protein films, used in artificial retinal implants, light modulators, three-dimensional optical memories, color photochromic sensors, photochromic and electrochromic papers and ink, biological camouflage and photo detectors for biodefense and non-defense purposes.

Evaluation of apoptosis-related genes: Fas (CD94), FasL (CD178) and TRAIL polymorphisms in Iranian multiple sclerosis patients.

Multiple sclerosis (MS) is a central nervous system (CNS) demyelinating disease characterized by a relapsing-remitting course leading to progressive disability. Given the critical role of apoptosis-related genes in the maintenance of homeostasis in the immune privilege sites, mutations in these genes have a profound effect on occurring autoimmune diseases such as multiple sclerosis. In the current study, polymorphisms in the apoptosis-related genes: Fas _-670 A>G, FasL _-844C>T, FasLIVS2nt _124 A>G and TRAIL_1595C>T were analyzed in 107 Iranian patients suffering from MS and 112 unrelated healthy controls using PCR-RFLP method. Our results demonstrated that among Iranian patients with MS and controls being homozygous in Fas_670A/A, G/G and FasL_-844C/C, TT in the promoter region and homozygocity in the minor allele for FasLIVS2nt_124G/G and TRAIL_1595C/C, polymorphisms were not associated with the MS risk in Iranian patients when compared with normal controls. However, the Fas _-670G/G genotype had a borderline significantly increased frequency with secondary progressive MS type (X(2)=5.8, P=0.05). In conclusion, no statistical association was found between the Fas, FasL and TRAIL polymorphisms and the risk of MS in Iranian patients.

The human caveolin 1 gene upstream purine complex and neurodegeneration--a common signature.

The caveolin 1 gene (CAV1) is over-expressed in experimental animal models of multiple sclerosis (MS). Increased expression of this gene has also been reported in the Alzheimer's disease (AD) brain. Loss of this gene, on the other hand, has recently been reported to be associated with neruodegeneration. We have recently reported skew in the homozygote haplotypes of the human CAV1 gene -1.5 kb upstream purine complex in patients afflicted with MS and late-onset AD vs. controls. In order to examine reproducibility of those findings, we sequenced the region in independent groups of MS patients (n=120) and controls (n=150). We report two novel extreme homozygote haplotypes at 86-bp and 142-bp in the patients vs. controls. The above haplotypes were also detected in the previously reported cases of late-onset AD. The range of homozygote haplotypes in the controls was detected at between 106-bp to 122-bp. Following pooling of the neurodegenerative (n=486) and non-neurodegenerative (n=610) subjects studied for the human CAV1 purine complex to date, twenty haplotypes were found to be homozygous in the neurodegenerative, and not in the control pool (p<0.000001). Six overlapping haplotypes were detected in the MS and AD patients (p<0.007), strengthening the role of this region as a common etiological factor in the pathophysiology of neurodegenerative disorders, possibly through inflammatory mechanisms. Those overlapping haplotypes contained motif lengths that were non-existent in the control homozygote pool. The CAV1 purine complex GGAA and GAAA motifs are binding sites for numerous inflammatory transcription factors including the Ets, STAT, and IRF family members. Further work on the functionality of this region will shed light on the downstream events to the disease-linked haplotypes.

The detection of disseminated tumor cells in bone marrow and peripheral blood of gastric cancer patients by multimarker (CEA, CK20, TFF1 and MUC2) quantitative real-time PCR.

OBJECTIVE: To investigate the suitability of multimarker detection of DTCs in PB and BM of GC patients. DESIGN AND METHOD: A qRT-PCR assay was developed to estimate the number of CEA, CK20, TFF1 and MUC2 transcripts in PB and BM samples of 35 GC patients prior to the initiation of therapy. PB samples from healthy volunteers and BM from patients with hematological malignancies were used as negative controls. RESULTS: In PB analysis; 22.9%, 37.1%, 31.4%, and 22.9% of GC patients and in BM analysis; 20%, 28.6%, 45.7%, and 22.9% of GC patients were positive for CEA, CK20, TFF1 and MUC2 mRNAs, respectively. Samples from the control group were negative for the expression of all the markers tested in this study. A higher positive ratio was obtained with the multimarker detection in comparison to the single marker detection. There was a significant correlation between the PB and BM samples for DTC detection. CONCLUSION: Multimarker detection assay is a reliable and powerful tool for the early detection of DTCs in GC patients.

ITPase-deficient mice show growth retardation and die before weaning.

Inosine triphosphate pyrophosphatase (ITPase), the enzyme that hydrolyzes ITP and other deaminated purine nucleoside triphosphates to the corresponding purine nucleoside monophosphate and pyrophosphate, is encoded by the Itpa gene. In this study, we established Itpa knockout (KO) mice and used them to show that ITPase is required for the normal organization of sarcomeres in the heart. Itpa(-/-) mice died about 2 weeks after birth with features of growth retardation and cardiac myofiber disarray, similar to the phenotype of the cardiac alpha-actin KO mouse. Inosine nucleotides were found to accumulate in both the nucleotide pool and RNA of Itpa(-/-) mice. These data suggest that the role of ITPase in mice is to exclude ITP from the ATP pool, and the main target substrate of this enzyme is rITP. Our data also suggest that cardiomyopathy, which is mainly caused by mutations in sarcomeric protein-encoding genes, is also caused by a defect in maintaining the quality of the ATP pool, which is an essential requirement for sarcomere function.