Genetic variability of human papillomavirus type 18 based on E6, E7 and L1 genes in central China.

BACKGROUND: High-risk human papillomavirus (HR-HPV) infection is an important factor for the development of cervical cancer. HPV18 is the second most common HR-HPV after HPV16. METHODS: In this study, MEGA11 software was used to analyze the variation and phylogenetic tree of HPV18 E6-E7 and L1 genes. The selective pressure to E6, E7 and L1 genes was estimated using pamlX. In addition, the B cell epitopes of L1 amino acid sequences and T cell epitopes of E6-E7 amino acid sequences in HPV18 were predicted by ABCpred server and IEDB website, respectively. RESULTS: A total of 9 single nucleotide variants were found in E6-E7 sequences, of which 2 were nonsynonymous variants and 7 were synonymous variants. Twenty single nucleotide variants were identified in L1 sequence, including 11 nonsynonymous variants and 9 synonymous variants. Phylogenetic analysis showed that E6-E7 and L1 sequences were all distributed in A lineage. In HPV18 E6, E7 and L1 sequences, no positively selected site was found. The nonconservative substitution R545C in L1 affected hypothetical B cell epitope. Two nonconservative substitutions, S82A in E6, and R53Q in E7, impacted multiple hypothetical T cell epitopes. CONCLUSION: The sequence variation data of HPV18 may lay a foundation for the virus diagnosis, further study of cervical cancer and vaccine design in central China.

Prevalence and genotype distribution of human papillomavirus infection among women in Jingzhou, China: a population-based study of 51,720 women.

BACKGROUND: Cervical cancer is the fourth most common cancer among women worldwide with a serious threat to women's health. Persistent infection with high-risk human papillomavirus (HR-HPV) has been identified as the main cause of cervical cancer. This study aimed to evaluate the prevalence and genotype distribution of HR-HPV among women in Jingzhou, Hubei province, China, which is critical for the government to formulate the precision strategies of cervical cancer screening and HPV vaccine innoculation. METHODS: To obtain the baseline data on the population-based prevalence and genotype distribution of HR-HPV infection among age groups and different years, a total of 51,720 women from 2018 to 2022 who went to Jingzhou Hospital Affiliated to Yangtze University for physical examination or gynacological treatment and received HR-HPV DNA genotyping were included in this retrospective study. The possible cervicovaginal infection of 15 high-risk HPV genotypes were analyzed by multiplex fluorescent real-time PCR, including HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68 and 82. RESULTS: The overall high-risk HPV prevalence among 51,720 women was 18.75% (9,698/51,720), and the HPV-positive rate of physical examination group (PEG) was 13.22% (541/4,091), which was lower than the HPV-positive rate of gynacological checkup group (GCG) 19.23% (9,157/47,629), with statistical difference (χ2 = 89.069, P < 0.01). The five most common prevalent genotypes were HPV52 (6.55%), HPV58 (3.41%), HPV16 (2.58%), HPV68 (1.82%) and HPV51 (1.57%). Single HPV infection was the predominant (14.36%), which compared to double (3.34%) and multiple (1.05%) infections. The HPV-positive rate was the highest in the > 60 age group (31.73%), and the lowest in the 31-40 age group (15.46%). CONCLUSIONS: The prevalence of high-risk HPV infection among women in Jingzhou area was 18.75%. HPV52, HPV58 and HPV16 genotypes were the most common. The higher prevalence was in the > 60 and ≤ 20 age group, which showed a "U" shape curve, suggesting the necessity of screening among older women to decrease the mortality of cervical cancer.

Genetic variation of E6 and E7 genes of human papillomavirus type 16 from central China.

BACKGROUND: Persistent high-risk human papillomavirus (HR-HPV) infection is an important factor in the development of cervical cancer, and human papillomavirus type 16 (HPV-16) is the most common HR-HPV type worldwide. The oncogenic potential of HPV-16 is closely related to viral sequence variation. METHODS: In order to clarify the variant characteristics of HPV-16 E6 and E7 genes in central China, E6 and E7 sequences of 205 HPV-16 positive samples were amplified by polymerase chain reaction. PCR products of E6 and E7 genes were further sequenced and subjected to variation analysis, phylogenetic analysis, selective pressure analysis and B-cell epitope prediction. RESULTS: Twenty-six single nucleotide variants were observed in E6 sequence, including 21 non-synonymous and 5 synonymous variants. Twelve single nucleotide variants were identified in E7 sequence, including 6 non-synonymous and 6 synonymous variants. Four new variants were found. Furthermore, nucleotide variation A647G (N29S) in E7 was significantly related to the higher risk of HSIL and cervical cancer. Phylogenetic analysis showed that the E6 and E7 sequences were all distributed in A lineage. No positively selected site was found in HPV-16 E6 and E7 sequences. Non-conservative substitutions in E6, H31Y, D32N, D32E, I34M, L35V, E36Q, L45P, N65S and K75T, affected multiple B-cell epitopes. However, the variation of E7 gene had little impact on the corresponding B-cell epitopes (score < 0.85). CONCLUSION: HPV-16 E6 and E7 sequences variation data may contribute to HR-HPV prevention and vaccine development in Jingzhou, central China.

Genetic diversity and functional implication of the long control region in human papillomavirus types 52, 58, and 16 from Central China.

OBJECT: High-risk human papillomavirus (HR-HPV) is a main reason for cervical cancer. The long control region (LCR) of the genome plays a variety of roles in the transcription of the virus. METHODS: LCR sequences were amplified by polymerase chain reaction (PCR) and confirmed by DNA sequencing. MEGA 11.0 software and NCBI blast were used to analyze the sequences and construct the Neighbor-Joining tree. In addition, the JASPAR database was used to predict the potential transcription factor binding sites (TFBS). RESULTS: For HPV-52 LCR, 68 single nucleotide polymorphisms (SNPs), 8 deletions, and 1 insertion were found, 17 of which were novel variations. Most of the variants were clustered in B2 sub-lineage (96.22%). For HPV-58 LCR, 25.43% of samples were prototype. 49 SNPs, 2 deletions, and 1 insertion were observed in the remaining samples. A1 sub-lineage was the most frequent (64.16%). For HPV-16 LCR, 75 SNPs and 2 deletions were identified, 13 of which were newly identified. A total of 55.68% of the variants were distributed in A4 sub-lineage. The JASPAR results suggested that multiple variations occurred in TFBSs, which might affect the function of transcription factors. CONCLUSIONS: This study provides experimental data for further studies on the epidemiology and biological function of LCR. Various LCR mutational data may prove useful for exploring the carcinogenic mechanism of HPV.

Association of TLR4 and TLR9 gene polymorphisms with the risk and progression of cervical lesions in HPV-infected women.

Aim: Toll-like receptors involved in tumor-associated inflammatory response, this study aimed to investigate the role of TLR4 and TLR9 gene polymorphisms in the risk and progression of HPV-related cervical lesions. Materials & methods: A total of 220 cervical lesion patients and 227 healthy controls were enrolled. Single-nucleotide polymorphisms were genotyped using PCR-restriction fragment length polymorphism. Results: A significantly decreased risk of cervical lesions was observed to be associated with the TLR4 rs10116253 (C), rs1927911 (T) and rs10759931 (G) mutant alleles. rs187084-rs1927911-HPV-16/18 was the best interaction model to affect cervical lesion risk. Conclusion: TLR4 rs10116253, rs1927911 and rs10759931 were potential biomarkers for cervical lesion susceptibility.

Cervical lesions are common diseases in women worldwide. Infection with high-risk HPV over a long time is a major risk factor for cervical lesions. Toll-like receptors play an important role in the natural defenses against virus infection. However, they may promote inflammation related to cancer development. The aim of this research was to investigate the association between TLR4/TLR9 gene polymorphisms and the risk/progression of HPV-related cervical lesions. The study found that mutant allele carriers of TLR4 rs10116253 (CT and CT + CC), rs1927911 (CT and CT + TT) and rs10759931 (AG and AG + GG) had a significantly decreased risk of cervical lesions compared with those carrying the wild-type homozygous genotypes. The interaction between TLR4/TLR9 gene polymorphisms and HPV-16/18 infection influenced cervical lesion risk. These results can be used to evaluate the risk of cervical lesions in women with high-risk HPV infection.

Association of TLR4 and TLR9 gene polymorphisms with cervical HR-HPV infection status in Chinese Han population.

BACKGROUND: Toll-like receptors (TLRs) may be involved in the natural history of human papillomavirus (HPV) infection. In our study, we aimed to investigate the association of TLR4 (rs10116253, rs1927911, rs10759931) and TLR9 (rs187084, rs352140) gene polymorphisms with cervical persistent high-risk HPV (HR-HPV) infection, as well as multiple HR-HPV infections. METHODS: A total of 269 study subjects were enrolled and grouped by retrospectively analyzing the HR-HPV testing results and other clinical data of 2647 gynecological outpatients from Jingzhou Hospital Affiliated to Yangtze University. We conducted a case-control study to compare the role of TLR4/TLR9 gene polymorphisms between HR-HPV transient and persistent infections, as well as between HR-HPV single and multiple infections. HR-HPV genotypes were detected using Real-time polymerase chain reaction (RT-PCR). PCR-restriction fragment length polymorphism (PCR-RFLP) was used to determine TLR4 and TLR9 gene polymorphisms. Analyses of the different outcome variables (HR-HPV infection status and time for HR-HPV clearance) with respect to TLR4/TLR9 polymorphisms were carried out. Logistic regression analysis was used to determine the association of TLR4/TLR9 genotypes and alleles with HR-HPV infection status. The Kaplan-Meier method with the log-rank test was used to analyze the relationship between TLR4/TLR9 genotypes and the time for HR-HPV clearance. RESULTS: The mutant genotypes of TLR9 rs187084 and rs352140 were associated with persistent (rs187084: CT and CT+CC; rs352140: CT and CT+TT) and multiple (rs187084: CT and CT+CC; rs352140: CT+TT) (all P < 0.05) HR-HPV infection. However, no association was found between TLR4 polymorphisms and HR-HPV infection status. Kaplan-Meier time to HR-HPV clearance analysis demonstrated that women carrying rs187084 and rs352140 mutant genotypes take longer duration to clear HR-HPV infection compared with wild-type genotype carriers (P1 = 0.012; P2 = 0.031). CONCLUSION: Our results suggested that TLR9 polymorphisms, but not TLR4, were associated with cervical persistent and multiple HR-HPV infections, which could be useful as a potential predictor of HR-HPV infection status.

Genetic variability of E6 and E7 genes of human papillomavirus type 58 in Jingzhou, Hubei Province of central China.

BACKGROUND: Cervical cancer is a common malignant tumor in women, with a high mortality rate, has great harm to women's health. Long-term and persistent infection of high-risk human papillomavirus (HR-HPV) is the main reason of the occurrence and development of cervical cancer. METHODS: The infection rate of HPV-58 is higher in the Jingzhou area. In this study, 172 complete HPV-58 E6-E7 sequences were amplified by polymerase chain reaction (PCR), the amplified products were sequenced, and the gene variations of HPV-58 E6-E7 were analyzed. A Neighbor-Joining phylogenetic tree was constructed by MEGA 11. The secondary structure of E6 and E7 protein was investigated. PAML X was used to analyze the selective pressure. The B cell epitopes of E6 and E7 proteins in HPV-58 were predicted by ABCpred server. RESULTS: In E6 sequences, 10 single nucleotide variants were observed, including 7 synonymous and 3 non-synonymous variants. In E7 sequences, 12 single nucleotide variants were found, including 3 synonymous variants and 9 non-synonymous variants. There are 5 novel variants. The phylogenetic analysis showed that all the E6-E7 sequences were distributed in A lineage. No positively selected site was found in E6 sequence, but G63 in E7 sequences was identified as positively selected site. Some amino acid substitutions affected multiple B cell epitopes. CONCLUSION: Various E6 and E7 mutational data may prove useful for development of better diagnostic and vaccines for the region of Jingzhou, Hubei province of central China.

Genetic variation of E6, E7, and L1 genes of human papillomavirus 51 from central China.

The incidence of cervical cancer is closely related to high-risk human papillomavirus (HR-HPV). Women in Jingzhou had relatively high susceptibility to HPV-51, whose ratio was 9.61% (456/4743) among HR-HPV-positive samples and ranked fifth in all analyzed HR-HPV types. In this study, variations and phylogenetic trees of HPV-51 E6-E7 and L1 sequences were analyzed by MEGA-X. The selective pressure was estimated using PAML. The B-cell epitope of L1 amino acid sequences and T-cell epitope of E6 and E7 amino acid sequences were further predicted by ABCpred server and IEDB website, respectively. In the E6-E7 sequences 14 single nucleotide variants occurred, among which 4 were nonsynonymous variants and 10 were synonymous variants. A total of 41 single nucleotide variants were identified in the L1 sequences, including 10 nonsynonymous variants and 31 synonymous variants. All the isolates of both E6-E7 and L1 were classified into the A variant lineage. In HPV-51 E6-E7 and L1 sequences, no positively selected site was found. Two nonconservative substitutions, H119Y and N176S in L1, affected multiple hypothetical B-cell epitopes. Three nonconservative substitutions, T86P, S100L in E6, and F29L in E7, affected multiple hypothetical T-cell epitopes. Elucidation of the HR-HPV prevalence characteristics and genetic variations of HPV-51 in central China may contribute to future investigations of diagnostic probes, therapeutic or preventative vaccines with wider coverage.

USF3 modulates osteoporosis risk by targeting WNT16, RANKL, RUNX2, and two GWAS lead SNPs rs2908007 and rs4531631.

Osteoporotic fractures cause major morbidity and mortality in the aging population. Genome-wide association studies (GWAS) have identified USF3 as the novel susceptibility gene of osteoporosis. However, the functional role in bone metabolism and the target gene of the basic helix-loop-helix transcription factor USF3 are unclear. Here, we show that USF3 enhances osteoblast differentiation and suppresses osteoclastogenesis in cultured human osteoblast-like U-2OS cells. Mechanistic studies revealed that transcription factor USF3 antagonistically interacts with anti-osteogenic TWIST1/TCF12 heterodimer in the WNT16 and RUNX2 promoter, and counteracts CREB1 and JUN/FOS in the RANKL promoter. Importantly, the osteoporosis GWAS variant g.1744A>G (rs2908007A>G) located in the WNT16 promoter confers G-allele-specific transcriptional modulation by USF3, TWIST1/TCF12 and TBX5/TBX15, and USF3 transactivates the osteoclastogenesis suppressor WNT16 promoter activity and antagonizes the repression of WNT16 by TWIST1 and TCF12. The risk G allele of osteoporosis GWAS variant g.3260A>G (rs4531631A>G) in the RANKL promoter facilitates the binding of CREB1 and JUN/FOS and enhances transactivation of the osteoclastogenesis contributor RANKL that is inhibited by USF3. Our findings uncovered the functional mechanisms of osteoporosis novel GWAS-associated gene USF3 and lead single nucleotide polymorphisms rs2908007 and rs4531631 in the regulation of bone formation and resorption.

Genetic variation of E6 and E7 genes of human papillomavirus 52 from Central China.

Cervical cancer is the fourth most common malignant tumor in women worldwide and is closely related to human papillomavirus (HPV). Women have the highest susceptibility to HPV-52 type in Jingzhou, China. In this study, E6-E7 sequences of 183 HPV-52 positive samples were amplified by a polymerase chain reaction and sequenced. HPV-52 E6-E7 gene variations were analyzed. The phylogenetic tree was constructed using the Kimura 2-parameter method. The secondary structure of the protein was analyzed. The selective pressure to E6-E7 genes was estimated using PAML. In addition, the B cell epitopes of the E6-E7 sequences in HPV-52 were predicted by the ABCpred server. In E6 sequences, 15 single nucleotide variants were observed, including 6 nonsynonymous variants and 9 synonymous variants. In E7 sequences, 19 single nucleotide variants occurred, including 10 nonsynonymous variants and 9 synonymous variants. Six amino acid variants, including 3 nonconservative substitutions, were found in sequences encoding the alpha helix. Eight amino acid variants, including three nonconservative substitutions, occurred in sequences encoding the strand. Through phylogenetic analysis, the E6-E7 sequences were mainly distributed in B lineage. In HPV-52 E6-E7 sequences, no positively selected site was found. The nonconservative substitutions, such as K93R, K93E in E6, T37I, and D38N in E7, affected multiple hypothetical epitopes in the B cell. This study provides information for the investigation of HPV epidemic characters. The discovery of new variants of HPV-52 may lay the basis for the development of the virus diagnosis, further study of cervical cancer, and vaccine design in Central China.

Osteoporosis genome-wide association study variant c.3781 C>A is regulated by a novel anti-osteogenic factor miR-345-5p.

Upstream transcription factor family member 3 (USF3) c.3781C>A (rs1026364) in the 3'-untranslated region (3'-UTR) has been firmly associated with bone mineral density (BMD) in genome-wide association study (GWAS). However, the molecular mechanism by which it influences BMD and osteoporosis is unknown. Bioinformatics analyses suggested that the risk c.3781A allele creates a target site for hsa-miR-345-5p binding. Luciferase assay validated that the c.3781A allele displayed significantly lower luciferase activities than the c.3781C allele in the human osteoblast cell line hFOB1.19, osteosarcoma cell lines U-2OS and Saos-2, and embryonic kidney cell line 293T. Furthermore, hsa-miR-345-5p regulated USF3 expression on both messenger RNA and protein levels in hFOB1.19 and U937 cells with heterozygous A/C genotype. Transfection of hsa-miR-345-5p antagomiR in heterozygous hFOB1.19 cells significantly increased the expression of osteogenic marker genes RUNX2, OSTERIX, COL1A1, ALP, OPN, OCN, and alkaline phosphatase activity and matrix mineralization level. Importantly, we found that hsa-miR-345-5p also inhibits osteoblast maturation in cell lines U-2OS with hsa-miR-345-5p nonbinding C/C genotype by targeting RUNX3 and SMAD1. Our findings uncovered a novel pathogenetic mechanism of osteoporosis by GWAS variant c.3781C>A-mediated disruption of hsa-miR-345-5p binding at the 3'-UTR of USF3 and the functional role of hsa-miR-345-5p in osteogenic differentiation.

LncRNA ZBTB40-IT1 modulated by osteoporosis GWAS risk SNPs suppresses osteogenesis.

Previous genome-wide linkage and association studies have identified an osteoporosis-associated locus at 1p36 that harbors SNPs rs34920465 and rs6426749. The 1p36 locus also comprises the WNT4 gene with known role in bone metabolism and functionally unknown ZBTB40/lncRNA ZBTB40-IT1 genes. How these might interact to contribute to osteoporosis susceptibility is not known. In this study, we show that lncRNA ZBTB40-IT1 is able to suppress osteogenesis and promote osteoclastogenesis by regulating the expression of WNT4, RUNX2, OSX, ALP, COL1A1, OPG and RANKL in U-2OS and hFOB1.19 cell lines, whereas ZBTB40 plays an opposite role in bone metabolism. Treatment with parathyroid hormone significantly downregulates the expression of ZBTB40-IT1 in U-2OS cell lines. ZBTB40 can suppress ZBTB40-IT1 expression but has no response to parathyroid hormone treatment. Dual-luciferase assay and biotin pull-down assay demonstrate that osteoporosis GWAS lead SNPs rs34920465-G and rs6426749-C alleles can respectively bind transcription factors JUN::FOS and CREB1, and upregulate ZBTB40 and ZBTB40-IT1 expression. Our study discovers the critical role of ZBTB40 and lncRNA ZBTB40-IT1 in bone metabolism, and provides a mechanistic basis for osteoporosis GWAS lead SNPs rs34920465 and rs6426749.

miR-125b promotes tau phosphorylation by targeting the neural cell adhesion molecule in neuropathological progression.

MicroRNAs, small noncoding RNAs, not only regulate gene expression at the post-transcriptional level in a variety of physiological processes but also accompany the initiation and progression of a vast number of diseases, including dementia. While miR-125b has been shown to be aberrantly expressed in some dementia patients, its role in the pathological process remains ambiguous. Presenilin-1/2 conditional double knockout mice exhibit a range of symptoms, including impaired cognition and memory, increased tau phosphorylation, neuroinflammation, and apoptosis, and are therefore regarded as a useful dementia model. In the prefrontal cortices of double knockout mice, miR-125b was found to be abnormally increased in an age-dependent manner. We further verified the neural cell adhesion molecule (NCAM) as an miR-125b target using the dual luciferase reporter assay. The NCAM protein level was decreased when miR-125b was overexpressed (OE) in neuronal growth factor-induced differentiated PC12 cells, which further inhibited the neuronal growth factor-induced phosphorylation of glycogen synthase kinase 3 beta (GSK3ß) at the Ser9 site and ultimately increased the GSK3ß activity and tau phosphorylation. Moreover, on serum deprivation, high GSK3ß activity in differentiated miR-125b-OE PC12 cells induced increased caspase-3 activation. Finally, adeno-associated virus-mediated miR-125b overexpression in the prefrontal cortexes of wild-type C57B/L6 mice resulted in decreased dendritic spine density. In addition, similar to the in vitro data, elevated GSK3ß activity and hyperphosphorylation of the tau protein were confirmed. Taken together, our findings reveal a direct regulation of miR-125b on NCAM, which leads to further effects on downstream GSK3ß activity and tau phosphorylation and may contribute to the generation of neurofibrillary tangles in neuropathological progression.

Computational and functional characterization of four SNPs in the SOST locus associated with osteoporosis.

The SOST gene encodes sclerostin, a C-terminal cysteine knot-like domain containing key negative regulator of osteoblastic bone formation that inhibits LRP5/6-mediated canonical Wnt signaling. Numerous single nucleotide polymorphisms (SNPs) in the SOST locus are firmly associated with bone mineral density (BMD) and fracture in genome-wide association studies (GWAS) and candidate gene association studies. However, the validation and mechanistic elucidation of causal genetic variants, especially for SNPs located beyond the promoter-proximal region, remain largely unresolved. By employing computational and experimental approaches, here we identify four SNPs rs1230399, rs7220711, rs1107748 and rs75901553 as functional variants which display allelic variation in SOST gene expression. The osteoporosis associated SNP rs1230399 in the SOST distal upstream regulatory region shows FOXA1 binding activity with subsequent transinactivation in a T allele-specific manner. The BMD GWAS lead SNPs rs7220711 and rs1107748 both reside in the 52-kb regulatory element deletion 35-kb downstream of the SOST gene which leads to Van Buchem disease. The rs7220711-A has a higher affinity for the transcriptional repressors MAFF or MAFK homodimers than rs7220711-G, while rs1107748 confers C allele specific transcriptional enhancer activity via a CTCF binding element. The variant rs75901553 C>T located in a conserved site of the SOST 3' UTR abolishes a target binding site for miR-98-5p which is negatively responsive to parathyroid hormone or 17ß-estradiol in osteoblastic cell lines. Our findings uncover the biological consequences of four independent genetic variants in the SOST region and their important roles in SOST expression via diverse mechanisms, providing new insights into the genetics and molecular pathogenesis of osteoporosis.

Inhibitor κBα protein therapy alleviates severe pneumonia through inhibition of nuclear factor κB.

To investigate the effect of inhibitor κBα (IκBα) on severe pneumonia and explain the mechanisms of nuclear factor κB (NF-κB), the activation of NF-κB was induced in Sprague-Dawley (SD) rats infected with Klebsiella pneumoniae (K. pneumoniae). The rats were then treated with differing concentrations of IκBα protein. A histological analysis was performed to compare the lung structure prior to and following treatment, and an immunohistochemistry assay was used to detect NF-κB activity. In addition, the expression of certain inflammatory factors was detected using a protein chip assay. The severe pneumonia rat model was successfully produced and in model rats, NF-κB was activated by K. pneumoniae. Following treatment with IκBα, the activity of NF-κB was inhibited and pneumonia symptoms in model rats were alleviated. Furthermore, the expression of a number of inflammatory factors including tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interferon γ (IFN-γ) and monocyte chemoattractant protein-1 (MCP-1) were also inhibited. The current study demonstrates that NF-κB inhibition with IκBα protein therapy prevents the development of pneumonia in a K. pneumoniae rat model. The therapeutic effect is indicated by the responses of proinflammatory factors, including TNF-α, IL-6, IFN-γ and MCP-1.

Characterization of a glutamine synthetase gene DvGS2 from Dunaliella viridis and biochemical identification of DvGS2-transgenic Arabidopsis thaliana.

The salt-tolerant green alga Dunaliella has remarkable capability to survive in some extreme environments such as nitrogen starvation, which makes Dunaliella be a proper model for mining novel genes on nitrogen uptake or assimilation. In this study, a glutamine synthetase (GS) gene DvGS2 with amino acid identity of 72% to other homologous GS proteins, was isolated and characterized from Dunaliella viridis. Phylogenetic comparison with other GSs revealed that DvGS2 occupied an independent phylogenetic position. Expressional analysis in D. viridis cells under nitrogen starvation confirmed that DvGS2 increased its mRNA level in 12h. Subcellular localization study and functional analysis in a GS-deficient Escherichia coli mutant proved that DvGS2 was a chloroplastic and functional GS enzyme. In order to investigate the potential application of DvGS2 in higher plants, the transgenic studies of DvGS2 in Arabidopsis thaliana were carried out. Results showed that the transgenic lines expressed the DvGS2 gene and demonstrated obviously enhanced root length (29%), fresh weight (40%-48% at two concentrations of nitrate supplies), stem length (21%), leaf size (39%) and silique number (44%) in contrast with the wild-type Arabidopsis. Furthermore, the transgenic lines had higher total nitrogen content (35%-43%), total GS activity (39%-45%) and soluble protein concentration (23%-24%) than the wild type. These results indicated that the overexpression of DvGS2 in A. thaliana resulted in higher biomass and the improvement of the host's nitrogen use efficiency.

MicroRNA-191 targets N-deacetylase/N-sulfotransferase 1 and promotes cell growth in human gastric carcinoma cell line MGC803.

As a family of post-transcriptional regulator of gene expression, the microRNAs (miRNAs) control a wide array of biological processes including cell differentiation, proliferation and apoptosis, and the dysregulation of miRNAs is a hallmark of cancer. Here, we found that the microRNA-191 (miR-191) was at a high-expression level in human gastric adenocarcinoma cell line MGC803 and human gastric cancer tissues. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays showed that miR-191 could promote cell growth and suppress apoptosis of MGC803 cells. The N-deacetylase/N-sulfotransferase 1 (NDST1) was confirmed to be a direct target gene of miR-191 by enhanced green fluorescent protein reporter experiment. The mRNA and protein levels of NDST1 were inversely correlated with miR-191 in MGC803 cells, suggesting the negative regulation of NDST1 by miR-191. Furthermore, NDST1 played an inhibitory role and could suppress MGC803 cell proliferation. Our findings suggested that miR-191 could act as an oncogene in MGC803 cells, and the cellular function was partially due to its negative regulation of NDST1.

Spatiotemporal multicolor labeling of individual cells using peptide-functionalized quantum dots and mixed delivery techniques.

Multicolor fluorescent labeling of both intra- and extracellular structures is a powerful technique for simultaneous monitoring of multiple complex biochemical processes. This approach remains extremely challenging, however, as it often necessitates the combinatorial use of numerous targeting probes (e.g., antibodies), multistep bioconjugation chemistries, different delivery strategies (e.g., electroporation or transfection reagents), cellular fixation coupled with membrane permeabilization, and complex spectral deconvolution. Here, we present a nanoparticle-based fluorescence labeling strategy for the multicolor labeling of distinct subcellular compartments within live cells without the need for antibody conjugation or cellular fixation/permeabilization. This multipronged approach incorporates an array of delivery strategies, which localize semiconductor quantum dots (QDs) to various subcellular structures. QD uptake is implemented in a spaciotemporal manner by staggering the delivery of QD-peptide composites and exploiting various innate (peptide-mediated endocytosis, peptide-membrane interaction, polymer-based transfection) along with physical (microinjection) cellular delivery modalities to live cells growing in culture over a 4 day period. Imaging of the different intracellular labels is simplified by the unique photophysical characteristics of the QDs in combination with Förster resonance energy transfer sensitization, which allow for multiple spectral windows to be accessed with one excitation wavelength. Using this overall approach, QDs were targeted to both early and late endosomes, the cellular cytosol, and the plasma membrane in live cells, ultimately allowing for simultaneous five-color fluorescent imaging.

Peptide p3 may play a neuroprotective role in the brain.

Alzheimer's disease (AD) is an age-related neurodegenerative disease. The amyloid-ß (Aß) peptide is considered a major etiological factor in the development of AD. BACE1-deficient mice and forebrain-specific conditional presenilin1 and presenilin2 double knockout mice (presenilins cDKO mice) both lack Aß, but exhibit completely different phenotypes. The peptide p3 may play a neuroprotective role. A lack of peptide p3 could trigger an inflammatory response in the brain of presenilins cDKO mice.