[Impaired cognitive map in transgenic animals relevant to Alzheimer's disease: from neurons to network].

Alzheimer's disease (AD) is a typical cognitive disorder with an increasing incidence in recent years. AD is also one of the main causes of disability and death of the elderly in current aging society. One of the most common symptoms of AD is spatial memory impairment, which occurs in more than 60% of patients. This memory loss is closely related to the impairment of cognitive maps in the brain. The entorhinal grid cells and the hippocampal place cells are important cellular basis for spatial memory and navigation functions in the brain. Understanding the abnormal firing pattern of these neurons and their impaired coordination to neural oscillations in transgenic rodents is crucial for identifying the therapeutic targets for AD. In this article, we review recent studies on neural activity based on transgenic rodent models of AD, with a focus on the changes in the firing characteristics of neurons and the abnormal electroencephalogram (EEG) rhythm in the entorhinal cortex and hippocampus. We also discuss potential cell-network mechanism of spatial memory disorders caused by AD, so as to provide a scientific basis for the diagnosis and treatment of AD in the future.

New data on mitogenomes of Thienemanniella Kieffer, 1911 (Diptera: Chironomidae, Orthocladiinae).

The mitochondrial genome (mitogenome) has been widely used as a powerful marker in phylogenetic and evolutionary studies of various Dipteran groups. However, only a few mitogenomes from the Thienemanniella genus have been reported till now. Furthermore, there is still indeterminacy in the phylogenetic relationships of the genus Thienemanniella. In this study, mitogenomes of five Thienemanniella species were sequenced and analyzed newly. Combined with the published mitogenome of Thienemanniella nipponica, the obtained results showed that mitogenomes of Thienemanniella were conserved in structure, and all genes were observed to be arranged in the same gene order as the ancestral mitogenome. Nucleotide composition varied significantly among different genes, and the control region displayed the highest A + T content. All protein coding genes are subjected to purification selection, and the fastest evolving gene is ATP8. Maximum likelihood and Bayesian inference analyses showed the phylogeny of Thienemanniella which was supported in five topologies. Our present study provides valuable insight into the phylogenetic relationships of Thienemanniella species.

Mitogenomes provide new insights of evolutionary history of Boreheptagyiini and Diamesini (Diptera: Chironomidae: Diamesinae).

Mitogenomes have been widely used for phylogenetic reconstruction of various Dipteran groups, but specifically for chironomid, they have not been carried out to resolve the relationships. Diamesinae (Diptera: Chironomidae) are important bioindicators for freshwater ecosystem monitoring, but its evolutionary history remains uncertain for lack of information. Here, coupled with one previously published and 30 new mitogenomes of Diamesinae, we carried out comparative mitogenomic analysis and phylogenetic analysis. Mitogenomes of Diamesinae were conserved in structure, and all genes arranged in the same order as the ancestral insect mitogenome. All protein-coding genes in Diamesinae were under stronger purifying selection than those of other nonbiting midge species, which may exhibit signs of adaptation to life at cold living conditions. Phylogenetic analyses strongly supported the monophyly of Diamesinae, with Boreheptagyiini deeply nested within Diamesini. In addition, phylogenetic relationship of selected six genera was resolved, except Sympotthastia remained unstable. Our study revealed that the mitogenomes of Diamesinae are highly conserved, and they are practically useful for phylogenetic inference.

First Report on Mitochondrial Gene Rearrangement in Non-Biting Midges, Revealing a Synapomorphy in Stenochironomus Kieffer (Diptera: Chironomidae).

(1) Background: Gene rearrangement of mitochondrial genome, especially those with phylogenetic signals, has long fascinated evolutionary biologists. The synapomorphic gene rearrangements have been identified across multiple orders and at many different taxonomic levels, supporting the monophyletic or systematic relationships of related lineages. However, mitochondrial gene rearrangement has never been observed in the non-biting midges (Diptera: Chironomidae); (2) methods: in this study, the complete mitogenomes of seven Stenochironomus species were sequenced and analyzed for the first time; (3) results: each mitogenome of Stenochironomus contains 37 typical genes and a control region. The whole mitogenomes of Stenochironomus species exhibit a higher A+T bias than other published chironomid species. The gene order rearranges from trnI-trnQ-trnM to trnI-trnM-trnQ in all the seven mitogenomes of Stenochironomus, which might be act as a synapomorphy of the genus, supporting the monophyletic of Stenochironomus species. In addition, another derived gene cluster: trnA-trnG-ND3-trnR exists in Stenochironomus tobaduodecimus. The derived gene orders described above are the first case of mitochondrial gene rearrangement in Chironomidae. Coupled with published data, phylogenetic relationships were reconstructed within Chironominae, and strongly supported the monophyly of Stenochironomus; (4) conclusions: our study provides new insights into the mitochondrial gene order of Chironomidae, and provides a valuable resource for understanding the synapomorphic gene rearrangements.

First complete mitogenomes of Diamesinae, Orthocladiinae, Prodiamesinae, Tanypodinae (Diptera: Chironomidae) and their implication in phylogenetics.

BACKGROUND: The mitochondrial genome (mitogenome) has been extensively used for phylogenetic and evolutionary analysis in Diptera, but the study of mitogenome is still scarce in the family Chironomidae. METHODS: Here, the first complete mitochondrial genomes of four Chironomid species representing Diamesinae, Orthocladiinae, Prodiamesinae and Tanypodinae are presented. Coupled with published mitogenomes of two, a comparative mitochondrial genomic analysis between six subfamilies of Chironomidae was carried out. RESULTS: Mitogenomes of Chironomidae are conserved in structure, each contains 37 typical genes and a control region, and all genes arrange the same gene order as the ancestral insect mitogenome. Nucleotide composition is highly biased, the control region displayed the highest A + T content. All protein coding genes are under purifying selection, and the ATP8 evolves at the fastest rate. In addition, the phylogenetic analysis covering six subfamilies within Chironomidae was conducted. The monophyly of Chironomidae is strongly supported. However, the topology of six subfamilies based on mitogenomes in this study is inconsistent with previous morphological and molecular studies. This may be due to the high mutation rate of the mitochondrial genetic markers within Chironomidae. Our results indicate that mitogenomes showed poor signals in phylogenetic reconstructions at the subfamily level of Chironomidae.

Rutaecarpine Ameliorated High Sucrose-Induced Alzheimer's Disease Like Pathological and Cognitive Impairments in Mice.

High sucrose can induce tau hyperphosphorylation and cognitive dysfunction/memory impairment as observed in Alzheimer's disease (AD). Rutaecarpine, a specific (transient receptor potential vanilloid 1 [TRPV1]) agonist, is neuroprotective against high sucrose diet-induced impairment, but detailed mechanisms are still elusive. In this study, we investigated whether rutaecarpine mitigates high sucrose diet-induced pathological alterations and cognitive in AD-like mice. Mice were administered fodder containing 0.01% rutaecarpine and 20% sucrose solution. Our results showed that rutaecarpine significantly attenuated high sucrose diet-induced spatial memory impairment and enhanced synaptic plasticity; rutaecarpine prevented high sucrose diet-induced tau hyperphosphorylation by decreasing glycogen synthase kinase-3ß (GSK-3ß) activity; activation of GSK-3ß reversed the protective effect of rutaecarpine on learning and memory deficits, synaptic plasticity, and tau hyperphosphorylation induced by high-glucose diet significantly, suggesting that GSK-3ß activation is required for high glucose-induced tau hyperphosphorylation. These results demonstrated that rutaecarpine can mitigate high sucrose diet-induced hyperphosphorylation of AD-associated tau protein and cognitive impairment by inhibiting GSK-3ß, which supported that dietary rutaecarpine might have a promising use for therapeutic intervention of AD.

[Progress in the encoding characteristics and mechanisms of hippocampal neural assemble sequences in spatial memory].

The formation, consolidation and retrieval of spatial memory depend on sequential firing patterns of place cells assembling in the hippocampus. Theta sequences of place cells during behavior play a role in acquisition of spatial memory, trajectory prediction and decision making. In awake rest and slow wave sleep, place cell sequences occur during the sharp wave-ripples (SWRs), called "replay", which is crucial for memory consolidation and retrieval. In this review, we summarize the functional significances of theta sequences and SWRs replay sequences and the mechanism of these sequences. We also discuss the relationship between theta and replay sequences with the formation of spatial memory. We propose the research direction in this field in future and aim to provide new ideas for related researches.

Two generalized algorithms measuring phase-amplitude cross-frequency coupling in neuronal oscillations network.

An increasing number of studies pays attention to cross-frequency coupling in neuronal oscillations network, as it is considered to play an important role in exchanging and integrating of information. In this study, two generalized algorithms, phase-amplitude coupling-evolution map approach and phase-amplitude coupling-conditional mutual information which have been developed and applied originally in an identical rhythm, are generalized to measure cross-frequency coupling. The effectiveness of quantitatively distinguishing the changes of coupling strength from the measurement of phase-amplitude coupling (PAC) is demonstrated based on simulation data. The data suggest that the generalized algorithms are able to effectively evaluate the strength of PAC, which are consistent with those traditional approaches, such as PAC-PLV and PAC-MI. Experimental data, which are local field potentials obtained from anaesthetized SD rats, have also been analyzed by these two generalized approaches. The data show that the theta-low gamma PAC in the hippocampal CA3-CA1 network is significantly decreased in the glioma group compared to that in the control group. The results, obtained from either simulation data or real experimental signals, are consistent with that of those traditional approaches PAC-MI and PAC-PLV. It may be considered as a proper indicator for the cross frequency coupling in sub-network, such as the hippocampal CA3 and CA1.

Range wide molecular data and niche modeling revealed the Pleistocene history of a global invader (Halyomorpha halys).

Invasive species' Pleistocene history contains much information on its present population structure, dispersability and adaptability. In this study, the Pleistocene history of a global invasive pest (Brown Marmorated Stink Bug BMSB, Halyomorpha halys) was unveiled using the coupled approach of phylogeography and ecological niche modelling. Rangewide molecular data suggests that the Taiwan and other native populations had diverged in mid-Pleistocene. In mainland China, the native BMSB did not experience population contraction and divergence during last glacial, but persisted in interconnected populations. Combined Bayesian Skyline Plot (BSP) and niche modelling revealed a rapid expansion occurred during the transition of Last Inter Glacial (LIG) to Last Glacial Maximum (LGM). High genetic diversity and multi-reticular haplotypes network exist in the original sources populations of BMSB invasion in northern China. They were speculated to be colonized from the central China, with many derived haplotypes evolved to adapt the novel environment. The ENM future prediction suggest that BMSB may expand northward to higher latitudes in the US and Europe, because of its high invasive ability, together with the available suitable climate space there.

[Genotypes and clinical features of 595 children with HbH disease in Guangxi, China].

OBJECTIVE: To investigate the genotypes and clinical features of children with HbH disease in Guangxi Zhuang Autonomous Region, China. METHODS: A total of 595 children from Guangxi were recruited. Single-tube multiplex polymerase chain reaction combined with agarose gel electrophoresis, as well as reverse dot blotting, were performed to detect the three α-globin gene deletion mutations (--(SEA), -α(3.7), and -α(4.2)) and three non-deletion mutations (Hb Westmead, Hb Constant Spring, and Hb Quong Sze) which are common in the Chinese population. RESULTS: Among the 595 cases, five common genotypes were identified, which were --(SEA)/-α(3.7) (232 cases), --(SEA)/α(CS)α (174 cases), --(SEA)/-α(4.2) (122 cases), --(SEA)/α(WS)α (35 cases), and --(SEA)/α(QS)α (24 cases). The genotype of THAI deletion associated with α-thalassemia-2 was detected in eight cases. Six ß-mutations including CD41-42, CD17-28, CD26, IVS-II-654, IVS-I-1, and CD27-28 were identified in 23 cases. All children with HbH disease had microcytic hypochromic anemia; children with HbH-CS disease had the most severe anemia, and those with HbH-WS disease had the mildest anemia. CONCLUSIONS: Deletional HbH disease is the main type in children with HbH disease in Guangxi, and some patients also have mild beta-thalassemia. Non-deletional HbH disease shows more severe phenotype than deletional HbH disease.

[Analysis of chromosomal abnormalities and a report of eight new karyotypes among children in genetic counseling].

OBJECTIVE: To study the relationship between abnormal karyotypes and clinical phenotypes among children in genetic counseling in Guangxi Zhuang Autonomous Region, China. METHODS: We studied 601 children who visited Guangxi Zhuang Autonomous Region Women and Children Care Hospital for genetic counseling between January 2009 and July 2012. Blood samples were cultured routinely for karyotype analysis with G banding as well as clinical analysis. RESULTS: Out of 601 patients, 329 (54.7%) had chromosomal abnormalities, and 8 new abnormal human karyotypes were found. Among 329 children with abnormal karyotypes, 317 (96.4%) had an abnormal number of chromosomes, and 12 (3.6%) had abnormal chromosomal structure. Abnormal karyotypes were clinically manifested by Down's syndrome (74.5%), growth retardation (10.9%), and mental retardation (3.0%). CONCLUSIONS: Eight rare abnormal karyotypes were found in the study, providing new resources for the genetic studies and etiological analysis of growth retardation, mental retardation, gonadal dysgenesis, and multiple congenital anomalies in children.

rs10505474 and rs7837328 at 8q24 cumulatively confer risk of prostate cancer in Northern Han Chinese.

AIMS: Genome-wide association studies (GWAS) have identified several risk variants for prostate cancer (pCa) mainly in Europeans, which need to be further verified in other racial groups. We selected six previously identified variants as candidates and to define the association with PCa in Northern Han Chinese. METHODS: 749 subjects from Beijing and Tianjin in Northern China were included. Six variants (rs10505474, rs7837328, rs4242384, rs7813, rs486907 and rs1058205) were genotyped by high resolution melting (HRM) assays. The individual and cumulative contribution for of the risk of PCa and clinical covariates were analyzed. RESULTS: Among the six candidate variants, only rs10505474, and rs7837328, both locating at 8q24 region, were associated with PCa in our population.rs10505474 (A) was associated with PCa (ORrecessive= 1.56, p=0.006); and rs7837328 (A) was associated with PCa (ORdominant= 1.38, p=0.042/ORrecessive=1.99, p=0.003). Moreover, we observed a cumulative effects between them (ptrend=2.58?10-5). The joint population attributable risk showed the two variants might account for 71.85% of PCa risk. In addition, we found the homozygotes of rs10505474 (A) and rs7837328 (A) were associated with PCa clinical covariants (age at onset, tumor stage, respectively) (page=0.046, Ptumorstage =0.048). CONCLUSION: rs10505474 (A) and rs7387328 (A) at 8q24 are associated with PCa and cumulatively confer risk, suggesting the two variations could determine susceptibility to PCa in the Northern Chinese Han population.

Association between APOC1 polymorphism and Alzheimer's disease: a case-control study and meta-analysis.

BACKGROUND: Previous association studies examining the relationship between the APOC1 polymorphism and susceptibility to Alzheimer's disease (AD) have shown conflicting results, and it is not clear if an APOC1 variant acts as a genetic risk factor in AD etiology across multiple populations. METHODS: To confirm the risk association between APOC1 and AD, we designed a case-control study and also performed a meta-analysis of previously published studies. RESULTS: Seventy-nine patients with AD and one hundred fifty-six unrelated controls were included in case-control study. No association was found between the variation of APOC1 and AD in stage 1 of our study. However, our meta-analysis pooled a total of 2092 AD patients and 2685 controls. The APOC1 rs11568822 polymorphism was associated with increased AD risk in Caucasians, Asians and Caribbean Hispanics, but not in African Americans. APOE ε4 carriers harboring the APOC1 insertion allele, were more prevalent in AD patients than controls (χ(2) = 119.46, OR = 2.79, 95% CI = 2.31-3.36, P<0.01). CONCLUSIONS: The APOC1 insertion allele, in combination with APOE ε4, likely serves as a potential risk factor for developing AD.

Trans-ethnical shift of the risk genotype in the CETP I405V with longevity: a Chinese case-control study and meta-analysis.

BACKGROUND: The I405V polymorphism of the cholesteryl ester transfer protein gene (CETP) has been suggested to be a protective factor conferring longevity in Ashkenazi Jews, although findings in other races are not supportive. This paper describes a case-control study and a meta-analysis conducted to derive a more precise estimation of the association between CETP 405V and longevity. METHODS: We enrolled 1,021 ethnic Han Chinese participants (506 in the longevity group and 515 controls), then performed a meta-analysis that integrated the current study and previously published ones. Pooled odds ratios (OR) were calculated for allele contrasts, dominant and recessive inheritance models to assess the association between CETP 405V and longevity according to the ethnic stratification. RESULTS: Our case-control data indicated that CETP 405V is a longevity risk allele in all genetic models (P additive =0.008; P dominant =0.008, OR(dominant)=0.673; P recessive =0.017, OR(recessive)=0.654) after adjustment for the apolipoprotein E (APOE) ε4 allele, body mass index and high-density lipoprotein cholesterol. A synergy was detected between 405V and APOE ε4 (P=0.001, OR=0.530). Eight studies were eligible for meta-analysis, which confirmed 405V is the risky allele against longevity in all genetic models: allele contrasts (OR=0.81, 95%CI=0.74-0.88), dominant model (OR=0.72, 95%CI=0.64-0.82) and recessive model (OR=0.80, 95%CI=0.67-0.96). After ethnic stratification, 405V remained a risk allele in East Asians but no significant association was found in Europeans or white Americans. CONCLUSION: Our case-control study suggests CETP 405V as a risk allele against longevity in Chinese. The meta-analysis suggests the involvement of CETP 405V is protective in Ashkenazi Jews but is a risk allele against longevity in the East Asian (Chinese) population.

[Cytogenetic analysis of 105 new human abnormal karyotypes].

To analyze the genetic effect of the abnormal chromosome karyotype, we summarized and studied the clinical data of the new abnormal karyotypes diagnosed at the Guangxi Zhuang Autonomous Region Women and Children Care Hospital from January 2009 to July 2012. The samples were cultured routinely for the karyotype analysis using G banding and C banding. Chromosomal aberrations were named according to the International System for Human Cytogenetic Nomenclature (ISCN 2009). Among tested samples, 105 new human abnormal karyotypes were identified (86 reciprocal translocation, 10 chromosomal inversion, six derivative chromosome, one duplication, one isochromosome, one partial trisomy and monosomy). The results suggest that chromosomal abnormalities were a major cause of miscarriage, infertility, congenital abnormalities, mental retardation and amenorrhea in humans.

[Association between SIRT1 gene polymorphisms and longevity of populations from Yongfu region of Guangxi].

OBJECTIVE: To assess the association between SIRT1 gene polymorphisms and the longevity phenomena in Yongfu region of Guangxi. In this case-control study, 500 individuals from Yongfu region of Guangxi were recruited. The subjects were divided into a longevity group (n=223, average age=93.17 U+00B1 3.08 yr) and a healthy control group (n=277, average age=46.92 U+00B1 17.12 yr). Polymerase chain reaction-high resolution melting curve (PCR-HRM) and DNA sequencing were used to determine the allelic and genotypic frequencies of rs3758391, rs3740051, rs2273773, rs4746720 and rs10997870 polymorphisms of SIRT1 gene in the two groups. The association between above polymorphisms and longevity was assessed. RESULTS: In the longevity group, CT genotype of the rs4746720 locus was significantly more common than CC and TT genotypes (P=0.000, OR=2.098, 95%CI:1.412-4.117). However, no significant difference was found in the allelic and genotypic frequencies of rs3758391, rs3740051 and rs2273773 between the two groups. CONCLUSION: There is an association between rs4746720 of SIRT1 gene and longevity in Yongfu region of Guangxi.

Genetic correction of ß-thalassemia patient-specific iPS cells and its use in improving hemoglobin production in irradiated SCID mice.

The generation of induced pluripotent stem cells (iPSCs) from differentiated somatic cells by over-expression of several transcription factors has the potential to cure many genetic and degenerative diseases currently recalcitrant to traditional clinical approaches. One such genetic disease is ß-thalassemia major (Cooley's anemia). This disease is caused by either a point mutation or the deletion of several nucleotides in the ß-globin gene, and it threatens the lives of millions of people in China. In the present study, we successfully generated iPSCs from fibroblasts collected from a 2-year-old patient who was diagnosed with a homozygous 41/42 deletion in his ß-globin gene. More importantly, we successfully corrected this genetic mutation in the ß-thalassemia iPSCs by homologous recombination. Furthermore, transplantation of the genetically corrected iPSCs-derived hematopoietic progenitors into sub-lethally irradiated immune deficient SCID mice showed improved hemoglobin production compared with the uncorrected iPSCs. Moreover, the generation of human ß-globin could be detected in the mice transplanted with corrected iPSCs-derived hematopietic progenitors. Our study provides strong evidence that iPSCs generated from a patient with a genetic disease can be corrected by homologous recombination and that the corrected iPSCs have potential clinical uses.

Molecular spectrum of α- and ß-globin gene mutations detected in the population of Guangxi Zhuang Autonomous Region, People's Republic of China.

We studied 6,023 individuals diagnosed with anemia on the basis of hematological examinations. The study showed that the frequency of α-thalassemia (α-thal) carriers was 26.9% and ß-thal carriers comprised 19.9% of the population of Guangxi Zhuang Autonomous Region, People's Republic of China (PCR). The diagnosed α-thal anomalies were related to six gene mutations and 16 genotypes, whereas the ß-thal were related to 10 gene mutations and 65 genotypes. The four most common mutations [codons 41/42 (-TTCT), codon 17 (A>T), -28 (A>G) and IVS-II-654 (C>T)] accounted for 86.38% of the ß-globin gene mutations. Risk analysis of mutation alleles in thalassemia cases identified four mutations (-α(3.7), -α(4.2), αα(Westmead) and αα(CS)) that were associated with α-thal intermedia, with an odds ratio (OR) of 62.41-32.68. Four high-risk mutations, namely, codon 26 (G>A), -28, codons 41/42 and codon 17, were associated with ß-thal major (ß-TM), with an OR of 3.93-2.20. The present study provides important genetic information on thalassemia in this population.

[Study on the longevity related mitochondrial genome variation in Bama elderly population in Guangxi province].

OBJECTIVE: To investigate the human mitochondrial DNA (mtDNA) variations associated with longevity in Bama elderly population from Guangxi. METHODS: Mitochondrial genome of 20 individuals over 96 years of age was sequenced, and seven target single nucleotide polymorphism (SNPs) were observed by comparing with the standard rCRS sequence, and two were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a larger population including 208 individuals of 90-113 years old, and 586 unrelated control individuals from Guangxi. RESULTS: The 4824G frequency of the mtDNA4824A/G locus increased with age both in the long-lived elderly and in controls. And it was significantly higher in controls than that in long-lived population (P<0.05). CONCLUSION: The mtDNA4824 A/G is not only an age-related locus, its mutation is also negatively correlated with longevity.

[Analysis of the chromosomal abnormality in 5774 patients with clinical reproductive abnormality and 32 new karyotypes].

To study the relationship between chromosomal abnormality and clinical ending events of reproductive abnormality, G-banding and karyotype analyses were carried out by using chromosome preparations from peripheral blood lymphocytes. Out of 5 774 cases with reproductive abnormality, 550 individuals had chromosomal abnormalities. Among them, 255 cases (46.36%) were trisomy, 91 cases (16.55%) were reciprocal translocation, 85 cases (15.45%) were chromosomal inversion, 81 cases (14.73%) were deletions, 21 cases (3.82%) were Robertsonian translocation, 7 cases (1.27%) were short arm increment, 6 cases (1.09%) were Y chromosome increment and 4 cases (0.73%) were abnormal satellites. Thirty-two cases with novel chromosomal abnormality karyotypes in them, being complicated by miscarriage, sterility, and congenital malformation, were firstly reported. The results suggested that chromosomal abnormality could be the one of main factors related to the bad reproductive ending events.