Akt as a Victim,Villain and Potential Hero in Parkinson’s Disease Pathophysiology and Treatment

There are two major purposes of this essay. The first is to summarize existing evidence that irrespective of the initiating causes, neuron death and degeneration in Parkinson’s disease (PD) are due to the common feature of failure of signaling by Akt, a kinase involved in neuron survival and maintenance of synaptic contacts. The second is to consider possible means by which such a failure of Akt signaling might be benignly prevented or reversed in neurons affected by PD, so as to treat PD symptoms, block disease progression, and potentially, promote recovery.     

Systematic analyses of free ceramide species and ceramide species comprising neutral glycosphingolipids by MALDI-TOF MS with high-energy CID

Free ceramides and glycosphingolipids (GSLs) are important components of the membrane microdomain and play significant roles in cell survival. Recent studies have revealed that both fatty acids and long-chain bases (LCBs) are more diverse than expected, in terms of i) alkyl chain length, ii) hydroxylation and iii) the presence or absence of double bonds. Electrospray ionization mass spectrometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) have been well utilized to characterize sphingolipids with high throughput, but reports to date have not fully characterized various types of ceramide species such as hydroxyl fatty acids and/or trihydroxy-LCBs of both free ceramides and the constituent ceramides in neutral GSLs. We performed a systematic analysis of both ceramide species, including LCBs with nona-octadeca lengths using MALDI-TOF MS with high-energy collision-induced dissociation (CID) at 20 keV. Using both protonated and sodiated ions, this technique enabled us to propose general rules to discriminate between isomeric and isobaric ceramide species, unrelated to the presence or absence of sugar chains. In addition, this high-energy CID generated ^3,5A ions, indicating Hex1-4Hex linkage in the sugar chains. Using this method, we demonstrated distinct differences among ceramide species, including free ceramides, sphingomyelins, and neutral GSLs of glucosylceramides, galactosylceramides, lactosylceramides, globotriaosylceramides and Forssman glycolipids in the equine kidneys.     

Expression,purification and functional characterization of a recombinant 2,3-dihydroxybiphenyl-1,2-dioxygenase from <Emphasis Type="Italic">Rhodococcus rhodochrous</Emphasis>

A 2,3-dihydroxybiphenyl (2,3-DHBP) dioxygenase gene from a Rhodococcus sp. strain, named RrbphCI and involved in the degradation of polychlorinated biphenyls (PCBs), was synthesized. RrbphCI was expressed in Escherichia coli and its encoded enzyme was purified. SDS–PAGE analysis indicated that the size of the protein encoded by RrbphCI was about 32 kDa. The activity of the 2,3-DHBP dioxygenase was 82.8 U/mg when the substrate was 2,3-DHBP, with optimum pH 8.0 at 30°C, and optimum temperature was 40°C at pH 8.0. The RrbphCI gene was transformed into Pseudomonas putida strain EG11, to determine the ability of the enzyme to degrade 2,3-DHBP. The wild type EG11 degraded 61.86% of supplied 2,3-DHBP and the transformed EG11 (hosting the RrbphCI gene) utilized 52.68% after 2 min of treatment at 30°C. The overexpressed and purified enzyme was able to degrade 2,3-DHBP. The 2,3-DHBP dioxygenase is a key enzyme in the PCB degradation pathway. RrbphCI and its encoded 2,3-DHBP dioxygenase may have transgenic applications in bioremediation of PCBs.     

Start codon FokI and intron 8 BsmI variants in the vitamin D receptor gene and susceptibility to colorectal cancer

Epidemiological evidence suggests the protective effect of vitamin D against colorectal cancer (CRC) and the polymorphisms in vitamin D receptor (VDR) gene may influence the development of CRC. In this study the possible association of VDR FokI and BsmI gene polymorphisms with CRC risk was examined. A total of 904 subjects, including 452 cases with CRC and 452 controls were enrolled in this study. All 904 subjects were genotyped for VDR FokI and BsmI gene polymorphisms by PCR-RFLP method. We observed no significant difference in genotype and allele frequencies between the cases with CRC and controls for the both FokI and BsmI polymorphisms either before or after adjustment for confounding factors including age, BMI, sex, and smoking status. Furthermore, no evidence for effect modification of the association VDR gene FokI and BsmI variants and CRC by BMI, sex, or tumor site was observed. In addition, there was no significant difference in genotype and allele frequencies between the normal weight (BMI <25 kg/m²) cases with CRC and overweight/obese (BMI ≥25 kg/m²) cases with CRC for the two SNPs. Our results do not lend support to the hypothesis that VDR gene FokI and BsmI polymorphisms are associated with the risk of CRC. However, further studies are required to confirm this finding.     

Expression of genes related to apoptosis,cell cycle and signaling pathways are independent of <Emphasis Type="Italic">TP53</Emphasis> status in urinary bladder cancer cells

Urinary bladder cancer is the fourth most common malignancy in the Western world. Transitional cell carcinoma (TCC) is the most common subtype, accounting for about 90% of all bladder cancers. The TP53 gene plays an essential role in the regulation of the cell cycle and apoptosis and therefore contributes to cellular transformation and malignancy; however, little is known about the differential gene expression patterns in human tumors that present with the wild-type or mutated TP53 gene. Therefore, because gene profiling can provide new insights into the molecular biology of bladder cancer, the present study aimed to compare the molecular profiles of bladder cancer cell lines with different TP53 alleles, including the wild type (RT4) and two mutants (5637, with mutations in codons 280 and 72; and T24, a TP53 allele encoding an in-frame deletion of tyrosine 126). Unsupervised hierarchical clustering and gene networks were constructed based on data generated by cDNA microarrays using mRNA from the three cell lines. Differentially expressed genes related to the cell cycle, cell division, cell death, and cell proliferation were observed in the three cell lines. However, the cDNA microarray data did not cluster cell lines based on their TP53 allele. The gene profiles of the RT4 cells were more similar to those of T24 than to those of the 5637 cells. While the deregulation of both the cell cycle and the apoptotic pathways was particularly related to TCC, these alterations were not associated with the TP53 status.     

Phylogeny of kangaroo apples (<Emphasis Type="Italic">Solanum</Emphasis> subg. <Emphasis Type="Italic">Archaesolanum</Emphasis>, Solanaceae)

Kangaroo apples, subgenus Archaesolanum, are a unique and still poorly known group within the genus Solanum. Here we aimed to reveal phylogeny, historical biogeography and age of diversification of Archaesolanum. We sampled all recognized species of the group and sequenced three chloroplast regions, the trnT-trnL spacer, trnL intron and trnL-trnF spacer to calibrate a molecular clock to estimate the age of the group. Distributional data were combined with the results of phylogenetic analysis to track the historical processes responsible for the current range of the group. Our analysis supported the monophyly of the kangaroo apples and the biogeographical disjunction between the two subclades within the group. Based on the divergence time estimates the most recent common ancestor of kangaroo apples is from the late Miocene age (~9 MYA). Based on the age estimate the common ancestors of the kangaroo apples are presumed to have arrived in Australia by long-distance dispersal. The two distinct lineages within the group have separated during the aridification of the continent and further speciated in the brief resurgence of rainforests during the Pliocene.     

Synthesis and characterization of graft copolymer of chitosan and polyethylene glycol

MPEG was modified with 1,1′-carbonyldiimidazole, then the activated MPEG reacted with primary amino groups of chitosan. Synthesize the graft copolymer of chitosan and polyethylene glycol in two steps. The structure of the copolymer was characterized by FT-IR and 1H-NMR. It agrees with the PEG content of classical stealth nanoparticles materials. The X-ray diffraction and DSC analysis proved that the crystallinity of the copolymer increased. It is a promising material for the stealth nanoparticles. It is a potential new carrier for the drug delivery systems of long-circulation and solid carcinoma.     

Season- and age-associated telomerase activity in <Emphasis Type="Italic">Ginkgo biloba</Emphasis> L.

Telomeres have lately received considerable attention in the development of broad-leaved tree species. In order to determine tissue-, sex-, season- and age-specific changes in telomerase activity in ginkgo trees, analyses of the telomerase repeat amplification protocol were carried out. In all of the tissues detected (embryonal callus, microspore tissues and leaves) telomerase activity was found, with differences between these activities statistically significant (P < 0.05). The highest telomerase activity was found in embryonal callus, suggesting that ginkgo trees have tissue-specific telomerase activity. Tissues containing high levels of dividing cells also have high levels of telomerase activity. No significant difference of telomerase activity was found between male and female trees (P > 0.05). In the annual development cycle, the highest telomerase activity was found in April and a decreasing trend over time in the four age groups studied: 10, 20, 70 and 700 year. The most obvious decline appeared in trees of the 700 year old group, suggesting that ginkgo trees have season-specific telomerase activities and trees of various ages react differently to seasonal changes. The mean annual telomerase activity showed a regular decreasing trend in all leaf samples analyzed from 10 to 700 year old ginkgo trees. We conclude that maintenance of telomere length depends on season- and age- associated telomerase activity. An optimal telomere length is regulated and maintained by telomerase in Ginkgo biloba L.     

Overexpression a novel zebra fish spermatogenesis-associated gene 17 (<Emphasis Type="Italic">SPATA17</Emphasis>) induces apoptosis in GC-1 cells

The spermatogenesis-associated 17 gene (SPATA17, previously named MSRG-11) was reported to be a candidate spermatocyte apoptosis-related gene which may play a critical role in human spermatogenesis, especially in meiosis. Analysis of SPATA17 expression and regulation in zebra fish may provide insight into the understanding of the complicated process of gonadogenesis and its potential function in spermatocyte cell apoptosis. In this study, we cloned and characterized the SPATA17 gene from zebra fish which consists of nine exons separated by eight introns. The consensus open reading frame (1258 bp) encodes a polypeptide of 357 amino acids which shares 44% identity with the human SPATA17 gene. Bioinformatic analysis reveals that SPATA17 protein contains three short calmodulin-binding motifs (IQ motif) and is considered to play a critical role in interactions with CaM proteins. Multi-tissue RT-PCR and Northern blot results demonstrated that the zebra fish SPATA17 gene was expressed strongly in testis and a slight amount of expression in ovary. Flow cytometry analysis and genomic DNA ladders result showed that the expression of SPATA17 protein in the GC-1 cell line could accelerate cell apoptosis. Analysis of the SPATA17 sequence and its spatial expression pattern indicate that this gene is highly conserved and may play an important role in the process of zebra fish gonadogenesis.