The dynamics of N6-methyladenine RNA modification in resistant and susceptible rice varieties responding to rice stem borer damage.

N6-methyladenosine (m6A) is the most prevalent modification in cellular RNA which orchestrates diverse physiological and pathological processes during stress response. However, the differential m6A modifications that cope with herbivore stress in resistant and susceptible crop varieties remain unclear. Here, we found that rice stem borer (RSB) larvae grew better on indica rice (e.g., MH63, IR64, Nanjing 11) than on japonica rice varieties (e.g., Nipponbare, Zhonghua 11, Xiushui 11). Then, transcriptome-wide m6A profiling of representative resistant (Nipponbare) and susceptible (MH63) rice varieties were performed using a nanopore direct RNA sequencing approach, to reveal variety-specific m6A modifications against RSB. Upon RSB infestation, m6A methylation occurred in actively expressed genes in Nipponbare and MH63, but the number of methylation sites decreased across rice chromosomes. Integrative analysis showed that m6A methylation levels were closely associated with transcriptional regulation. Genes involved in herbivorous resistance related to mitogen-activated protein kinase, jasmonic acid (JA), and terpenoid biosynthesis pathways, as well as JA-mediated trypsin protease inhibitors, were heavily methylated by m6A, and their expression was more pronounced in RSB-infested Nipponbare than in RSB-infested MH63, which may have contributed to RSB resistance in Nipponbare. Therefore, dynamics of m6A modifications act as the main regulatory strategy for expression of genes involved in plant-insect interactions, which is attributed to differential responses of resistant and susceptible rice varieties to RSB infestation. These findings could contribute to developing molecular breeding strategies for controlling herbivorous pests.

Tyrosine hydroxylase plays crucial roles in larval cuticle formation and larval-pupal tanning in the rice stem borer, Chilo suppressalis.

The striped stem borer, Chilo suppressalis (Walker), a notorious pest infesting rice, has evolved a high level of resistance to many commonly used insecticides. In this study, we investigate whether tyrosine hydroxylase (TH), which is required for larval development and cuticle tanning in many insects, could be a potential target for the control of C. suppressalis. We identified and characterized the full-length cDNA (CsTH) of C. suppressalis. The complete open reading frame of CsTH (MW690914) was 1683 bp in length, encoding a protein of 560 amino acids. Within the first to the sixth larval instars, CsTH was high in the first day just after molting, and lower in the ensuing days. From the wandering stage to the adult stage, levels of CSTH began to rise and reached a peak at the pupal stage. These patterns suggested a role for the gene in larval development and larval-pupal cuticle tanning. When we injected dsCsTH or 3-iodotyrosine (3-IT) as a TH inhibitor or fed a larva diet supplemented with 3-IT, there were significant impairments in larval development and larval-pupal cuticle tanning. Adult emergence was severely impaired, and most adults died. These results suggest that CsTH might play a critical role in larval development as well as larval-pupal tanning and immunity in C. suppressalis, and this gene could form a potential novel target for pest control.

Defence and nutrition synergistically contribute to the distinct tolerance of rice subspecies to the stem borer, Chilo suppressalis.

Damage caused by the rice striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is much more severe on indica/xian rice than on japonica/geng rice (Oryza sativa) which matches pest outbreak data in cropping regions of China. The mechanistic basis of this difference among rice subspecies remains unclear. Using transcriptomic, metabolomic and genetic analyses in combination with insect bioassay experiments, we showed that japonica and indica rice utilise different defence responses to repel SSB, and that SSB exploited plant nutrition deficiencies in different ways in the subspecies. The more resistant japonica rice induced patterns of accumulation of methyl jasmonate (MeJA-part of a defensive pathway) and vitamin B1 (VB1-a nutrition pathway) distinct from indica cultivars. Using gene-edited rice plants and SSB bioassays, we found that MeJA and VB1 jointly affected the performance of SSB by disrupting juvenile hormone levels. In addition, genetic variants of key biosynthesis genes in the MeJA and VB1 pathways (OsJMT and OsTH1, respectively) differed between japonica and indica rice and contributed to performance differences; in indica rice, SSB avoided the MeJA defence pathway and hijacked the VB1 nutrition-related pathway to promote development. The findings highlight important genetic and mechanistic differences between rice subspecies affecting SSB damage which could be exploited in plant breeding for resistance.

Gene polymorphisms associated with sudden decreases in heart rate during extensive peritoneal lavage with distilled water after gastrectomy.

BACKGROUND: Our previous study found that the telomerase-associated protein 1 (TEP1, rs938886 and rs1713449) and homo sapiens RecQ like helicase 5 (RECQL5, rs820196) single nucleotide polymorphisms (SNPs) were associated with changes in heart rate (HR) ≥ 30% during peritoneal lavage with distilled water after gastrectomy. This study established a single tube method for detecting these three SNPs using two-dimensional (2D) polymerase chain reaction (PCR), and investigated whether SNP-SNP and SNP-environment interactions increase the risk of high HR variability (HRV). AIM: To investigate whether genotypes, genetic patterns, SNP-SNP and SNP-environment interactions were associated with HRV. METHODS: 2D PCR was used to establish a single-tube method to detect TEP1 rs938886 and rs1713449 and RECQL5 rs820196, and the results were compared with those of sanger sequencing. After adjusting for confounders such as age, sex, smoking, hypertension, and thyroid dysfunction, a nonconditional logistic regression model was used to assess the associations between the genotypes and the genetic patterns (codominant, dominant, overdominant, recessive, and additive) of the three SNPs and a risk ≥ 15% or ≥ 30% of a sudden drop in HR during postoperative peritoneal lavage in patients with gastric cancer. Gene-gene and gene-environment interactions were analyzed using generalized multifactor dimensionality reduction. RESULTS: The coincidence rate between the 2D PCR and sequencing was 100%. When the HRV cutoff value was 15%, the patients with the RECQL5 (rs820196) TC genotype had a higher risk of high HRV than those who had the TT genotype (odds ratio = 1.97; 95%CI: 1.05-3.70; P = 0.045). Under the codominant and overdominant models, the TC genotype of RECQL5 (rs820196) was associated with a higher risk of HR decrease relative to the TT and TT + CC genotypes (P = 0.031 and 0.016, respectively). When the HRV cutoff value was 30%, patients carrying the GC-TC genotypes of rs938886 and rs820196 showed a higher HRV risk when compared with the GG-TT genotype carriers (P = 0.01). In the three-factor model of rs938886, rs820196, and rs1713449, patients carrying the GC-TC-CT genotype had a higher risk of HRV compared with the wild-type GG-TT-CC carriers (P = 0.01). For rs820196, nonsmokers with the TC genotype had a higher HRV risk compared with nonsmokers carrying the TT genotype (P = 0.04). When the HRV cutoff value was 15%, patients carrying the TT-TT and the TC-CT genotypes of rs820196 and rs1713449 showed a higher HRV risk when compared with TT-CC genotype carriers (P = 0.04 and 0.01, respectively). Patients carrying the GC-CT-TC genotypes of rs938886, rs1713449, and rs820196 showed a higher HRV risk compared with GG-CC-TT genotype carriers (P = 0.02). When the HRV cutoff value was 15%, the best-fitting models for the interactions between the SNPs and the environment were the rs820196-smoking (P = 0.022) and rs820196-hypertension (P = 0.043) models. Consistent with the results of the previous grouping, for rs820196, the TC genotype nonsmokers had a higher HRV risk compared with nonsmokers carrying the TT genotype (P = 0.01). CONCLUSION: The polymorphism of the RECQL5 and TEP1 genes were associated with HRV during peritoneal lavage with distilled water after gastrectomy.

Identification of a fatty acid synthase gene (FAS1) from Laodelphax striatellus planthoppers contributing to fecundity.

Fatty acid synthase (FAS) is a multifunctional enzyme that plays an important role in the formation of fatty acids. The fatty acids take part in many processes, such as cell signaling and energy metabolism, and in insects they are important in both cuticular hydrocarbon (CHC) formation and reproduction. Here we characterized the sequence structure and function of an FAS from the small brown planthopper (SBPH), Laodelphax striatellus. The full-length open reading frame (ORF) sequence of LsFAS1 was 7122 bp, encoding a predicted protein of 2373 amino acid residues. There were 7 functional domains in the LsFAS1 protein sequence. Gene expression screening by real-time quantitative polymerase chain reaction (RT-qPCR) showed that LsFAS1 was expressed in all developmental stages. Relative expression was highest at the 4th-instar and female adult stages. Among different tissues, the expression level of LsFAS1 in the ovary was the highest. Phylogenetic analysis showed that LsFAS1 clustered in a clade with 2 FASs from Nilaparvata lugens. Furthermore, these 3 FASs are related to cockroach BgFAS and locust LmFAS. After RNA interference-mediated knock-down, most treated insects died at eclosion. In addition, the lifespan of dsFAS1-treated female adults was shorter than that of the dsGFP-injected control, and offspring production decreased. Also, the expression of vitellogenin (Vg) and vitellogenin receptor (VgR) genes decreased. Virgin females dissected at days 2 and 4 post-eclosion showed many matured oocytes in planthoppers treated with dsGFP but not with dsFAS1. These data highlight the importance of LsFAS1 in SBPH, including a role in reproduction.

SoxC is Required for Ecdysteroid Induction of Neuropeptide Genes During Insect Eclosion.

In insects, the shedding of the old exoskeleton is accomplished through ecdysis which is typically followed by the expansion and tanning of the new cuticle. Four neuropeptides, eclosion hormone (EH), ecdysis triggering hormone (ETH), crustacean cardioactive peptide (CCAP) and bursicon (Bur) are known to control ecdysis. However, the regulation of these neuropeptide genes is still poorly understood. Here, we report that in the red flour beetle (RFB) Tribolium castaneum and the fall armyworm (FAW) Spodoptera frugiperda, knockdown or knockout of the SoxC gene caused eclosion defects. The expansion and tanning of wings were not complete. In both RFB and FAW, the knockdown or knockout of SoxC resulted in a decrease in the expression of EH gene. Electrophoretic mobility shift assays revealed that the SfSoxC protein directly binds to a motif present in the promoter of SfEH. The luciferase reporter assays in Sf9 cells confirmed these results. These data suggest that transcription factor SoxC plays a key role in ecdysteroid induction of genes coding for neuropeptides such as EH involved in the regulation of insect eclosion.

Assessment of structural brain changes in patients with type 2 diabetes mellitus using the MRI-based brain atrophy and lesion index.

Patients with type 2 diabetes mellitus (T2DM) often have cognitive impairment and structural brain abnormalities. The magnetic resonance imaging (MRI)-based brain atrophy and lesion index can be used to evaluate common brain changes and their correlation with cognitive function, and can therefore also be used to reflect whole-brain structural changes related to T2DM. A total of 136 participants (64 men and 72 women, aged 55-86 years) were recruited for our study between January 2014 and December 2016. All participants underwent MRI and Mini-Mental State Examination assessment (including 42 healthy control, 38 T2DM without cognitive impairment, 26 with cognitive impairment but without T2DM, and 30 T2DM with cognitive impairment participants). The total and sub-category brain atrophy and lesion index scores in patients with T2DM with cognitive impairment were higher than those in healthy controls. Differences in the brain atrophy and lesion index of gray matter lesions and subcortical dilated perivascular spaces were found between non-T2DM patients with cognitive impairment and patients with T2DM and cognitive impairment. After adjusting for age, the brain atrophy and lesion index retained its capacity to identify patients with T2DM with cognitive impairment. These findings suggest that the brain atrophy and lesion index, based on T1-weighted and T2-weighted imaging, is of clinical value for identifying patients with T2DM and cognitive impairment. Gray matter lesions and subcortical dilated perivascular spaces may be potential diagnostic markers of T2DM that is complicated by cognitive impairment. This study was approved by the Medical Ethics Committee of University of South China (approval No. USC20131109003) on November 9, 2013, and was retrospectively registered with the Chinese Clinical Trial Registry (registration No. ChiCTR1900024150) on June 27, 2019.

Impact of metabolism-related mutations on the heart rate of gastric cancer patients after peritoneal lavage.

BACKGROUND: During surgery for gastric cancer, peritoneal lavage using warm distilled water can cause temporary hemodynamic changes. AIM: To examine the associations between changes in heart rate and single nucleotide polymorphisms (SNPs). METHODS: This was a prospective observational study of patients with gastric cancer who underwent gastrectomy and peritoneal hypotonic lavage at the Third Affiliated Hospital of Soochow University from March 2018 to March 2019. Related SNPs were selected, and the verified exons were analyzed. Heart rate and blood pressure (BP) were measured before and after lavage. The patients were grouped as heart rate change ≥ 30% vs < 30%. Comparison and regression analyses of the selected SNPs were performed between the two groups. RESULTS: According to the inclusion/exclusion criteria, 194 patients were included in the analysis. Of these patients, 138 were male, with a mean age of 65.9 ± 0.8 years, and 56 were female, with a mean age of 65.0 ± 1.3 years. Heart rate dropped by 0%-10% in 65 participants, by 10%-15% in 29, by 15%-20% in 23, by 20%-50% in 39, by 50%-100% in four, six had a cardiac arrest, and 28 had an increase in heart rate. Considering the possible impact of exonic SNPs on the phenotypes, TEP1 (rs938886), TEP1 (rs1713449), and RECQL5 (rs820196) were analyzed. The haplotype analysis suggested that the haplotypes CTT [odds ratio (OR) = 2.018, 95% confidence interval (CI): 1.012-4.025, P = 0.0430] and GCC (OR = 2.293, 95%CI: 1.174-4.477, P = 0.0131) of TEP1 (rs938886), TEP1 (rs1713449), and RECQL5 (rs820196) increased the risk of a drop in heart rate > 30%. CONCLUSION: The TEP1 (rs938886), TEP1 (rs1713449), and RECQL5 (rs820196) SNPs were associated with changes in heart rate ≥ 30% during intraperitoneal lavage using distilled water after gastrectomy for gastric cancer.

Magnetic Resonance Texture Analysis in Alzheimer's disease.

Texture analysis is an emerging field that allows mathematical detection of changes in MRI signals that are not visible among image pixels. Alzheimer's disease, a progressive neurodegenerative disease, is the most common cause of dementia. Recently, multiple texture analysis studies in patients with Alzheimer's disease have been performed. This review summarizes the main contributors to Alzheimer's disease-associated cognitive decline, presents a brief overview of texture analysis, followed by review of various MR imaging texture analysis applications in Alzheimer's disease. We also discuss the current challenges for widespread clinical utilization. MR texture analysis could potentially be applied to develop neuroimaging biomarkers for use in Alzheimer's disease clinical trials and diagnosis.

DNA methylation detection methods used in colorectal cancer.

Colorectal cancer (CRC) remains a major contributor to the number of cancer-related deaths that occur annually worldwide. With the development of molecular biology methods, an increasing number of molecular biomarkers have been identified and investigated. CRC is believed to result from an accumulation of epigenetic changes, and detecting aberrant DNA methylation patterns is useful for both the early diagnosis and prognosis of CRC. Numerous studies are focusing on the development of DNA methylation detection methods or DNA methylation panels. Thus, this review will discuss the commonly used techniques and technologies to evaluate DNA methylation, their merits and deficiencies as well as the prospects for new methods.

Porphyromonas gingivalis and digestive system cancers.

Porphyromonas gingivalis (P. gingivalis) is an anaerobic gram-negative bacterium that colonizes in the epithelium and has been strongly associated with periodontal disease. Recently, various degrees of associations between P. gingivalis and digestive system cancers, including oral squamous cell carcinoma in the oral cavity, oesophageal squamous carcinoma in the digestive tract, and pancreatic cancer in pancreatic tissues, have been displayed in multiple clinical and experimental studies. Since P. gingivalis has a strong association with periodontal diseases, not only the relationships between P. gingivalis and digestive system tumours but also the effects induced by periodontal diseases on cancers are well-illustrated in this review. In addition, the prevention and possible treatments for these digestive system tumours induced by P. gingivalis infection are also included in this review. At the end, we also highlighted the possible mechanisms of cancers caused by P. gingivalis. One important carcinogenic effect of P. gingivalis is inhibiting the apoptosis of epithelial cells, which also plays an intrinsic role in protecting cancerous cells. Some signalling pathways activated by P. gingivalis are involved in cell apoptosis, tumourigenesis, immune evasion and cell invasion of tumour cells. In addition, metabolism of potentially carcinogenic substances caused by P. gingivalis is also one of the connections between this bacterium and cancers.

Short hairpin RNA-mediated knockdown of nuclear factor erythroid 2-like 3 exhibits tumor-suppressing effects in hepatocellular carcinoma cells.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with high mortality-to-incidence ratios. Nuclear factor erythroid 2-like 3 (NFE2L3), also known as NRF3, is a member of the cap 'n' collar basic-region leucine zipper family of transcription factors. NFE2L3 is involved in the regulation of various biological processes, whereas its role in HCC has not been elucidated. AIM: To explore the expression and biological function of NFE2L3 in HCC. METHODS: We analyzed the expression of NFE2L3 in HCC tissues and its correlation with clinicopathological parameters based on The Cancer Genome Atlas (TCGA) data portal. Short hairpin RNA (shRNA) interference technology was utilized to knock down NFE2L3 in vitro. Cell apoptosis, clone formation, proliferation, migration, and invasion assays were used to identify the biological effects of NFE2L3 in BEL-7404 and SMMC-7721 cells. The expression of epithelial-mesenchymal transition (EMT) markers was examined by Western blot analysis. RESULTS: TCGA analysis showed that NFE2L3 expression was significantly positively correlated with tumor grade, T stage, and pathologic stage. The qPCR and Western blot results showed that both the mRNA and protein levels of NFE2L3 were significantly decreased after shRNA-mediated knockdown in BEL-7404 and SMMC-7721 cells. The shRNA-mediated knockdown of NFE2L3 could induce apoptosis and inhibit the clone formation and cell proliferation of SMMC-7721 and BEL-7404 cells. NFE2L3 knockdown also significantly suppressed the migration, invasion, and EMT of the two cell lines. CONCLUSION: Our study showed that shRNA-mediated knockdown of NFE2L3 exhibited tumor-suppressing effects in HCC cells.

Apolipoprotein M induces inhibition of inflammatory responses via the S1PR1 and DHCR24 pathways.

Apolipoprotein M (ApoM) is a type of apolipoprotein. It is well known that high­density lipoprotein (HDL) decreases inflammatory responses via the apoM­sphingosine­1­phosphate (S1P) pathway. The present study further investigated the importance of ApoM in the inhibitory effects of HDL on inflammation. Mice with an apoM gene deficiency (apoM­/­) were employed to investigate the effects of ApoM on the expression of interleukin­1ß (IL­1ß), monocyte chemotactic protein­1 (MCP­1), S1P receptor­1 (S1PR1) and 3ß­hydroxysterol Δ­24­reductase (DHCR24), as compared with in wild­type mice (apoM+/+). Furthermore, cell culture experiments were performed using a permanent human hybrid endothelial cell line (EA.hy926). Cells were cultured in the presence of recombinant human apoM (rec­apoM) or were induced to overexpress apoM (apoMTg); subsequently, cells were treated with tumor necrosis factor­α (TNF­α), in order to investigate the effects of ApoM on IL­1ß and MCP­1. The results demonstrated that the mRNA expression levels of IL­1ß and MCP­1 were significantly higher in the liver following administration of lipopolysaccharide in apoM­/­ mice compared with in apoM+/+ mice. In cell culture experiments, when cells were pre­cultured with rec­apoM or were engineered to overexpress apoM (apoMTg), they exhibited decreased expression levels of IL­1ß and MCP­1 following TNF­α treatment compared with in normal apoM­expressing cells (apoMTgN). Furthermore, the mRNA expression levels of IL­1ß and MCP­1 were significantly elevated following addition of the S1PR1 inhibitor W146, but not by the scavenger receptor class B type I inhibitor, block lipid transport­1 (BLT­1), in apoMTg cells prior to TNF­α treatment. Conversely, there were no differences in these inflammatory biomarkers under the same conditions in apoMTgN cells. The mRNA expression levels of DHCR24 were significantly reduced by the addition of BLT­1 prior to TNF­α treatment in apoMTg cells; however, there was no difference in the expression of this inflammatory biomarker in apoMTgN cells. In conclusion, ApoM displayed inhibitory effects against the inflammatory response in vivo and in vitro; these effects may be induced via the S1PR1 and DHCR24 pathways.

Increased apolipoprotein M induced by lack of scavenger receptor BI is not activated via HDL-mediated cholesterol uptake in hepatocytes.

BACKGROUND: Scavenger receptor BI (SR-BI) is a classic high-density lipoprotein (HDL) receptor, which mediates selective lipid uptake from HDL cholesterol esters (HDL-C). Apolipoprotein M (ApoM), as a component of HDL particles, could influence preß-HDL formation and cholesterol efflux. The aim of this study was to determine whether SR-BI deficiency influenced the expression of ApoM. METHODS: Blood samples and liver tissues were collected from SR-BI gene knockout mice, and serum lipid parameters, including total cholesterol (TC), triglyceride (TG), high and low-density lipoprotein cholesterol (HDL-C and LDL-C) and ApoM were measured. Hepatic ApoM and ApoAI mRNA levels were also determined. In addition, BLT-1, an inhibitor of SR-BI, was added to HepG2 cells cultured with cholesterol and HDL, under serum or serum-free conditions. The mRNA and protein expression levels of ApoM were detected by RT-PCR and western blot. RESULTS: We found that increased serum ApoM protein levels corresponded with high hepatic ApoM mRNA levels in both male and female SR-BI-/- mice. Besides, serum TC and HDL-C were also significantly increased. Treatment of HepG2 hepatoma cells with SR-BI specific inhibitor, BLT-1, could up-regulate ApoM expression in serum-containing medium but not in serum-free medium, even in the presence of HDL-C and cholesterol. CONCLUSIONS: Results suggested that SR-BI deficiency promoted ApoM expression, but the increased ApoM might be independent from HDL-mediated cholesterol uptake in hepatocytes.

Apolipoprotein M Protects Against Lipopolysaccharide-Induced Acute Lung Injury via Sphingosine-1-Phosphate Signaling.

It had been demonstrated that apolipoprotein M (apoM) is an important carrier of sphingosine-1-phosphate (S1P) in blood, and the S1P has critical roles in the pathogenesis of sepsis-induced acute lung injury (ALI). In the present study, we investigated whether apoM has beneficial effects in a mouse model after lipopolysaccharide (LPS)-induced ALI. Forty-eight mice were divided into two groups: male C57BL/6 wild-type (apoM+/+) group (n = 24) and apoM gene-deficient (apoM-/-) group (n = 24) and then randomly subdivided into four subgroups (n = 6 each) according to different intraperitoneal (i.p.) injection: control group, W146 group, LPS group, and LPS + W146 group. Serum levels of interleukin-1 beta (IL-1ß) and mRNA levels of IL-1ß, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), lung histology, wet/dry weight ratio, and immunohistochemistry were measured at 3 h after the baseline and compared in each group. Our results clearly demonstrated that IL-1ß mRNA levels and other inflammatory biomarkers were significantly increased in the lungs of LPS-induced ALI apoM-/- mice compared to those of the apoM+/+ mice. Moreover, when apoM+/+ mice were treated with W146, a S1P receptor (S1PR1) antagonist, these inflammatory biomarkers could be significantly upregulated by LPS-induced ALI. Therefore, it suggests that apoM-S1P-S1PR1 signaling might underlie the pathogenesis of ALI and apoM could have physiological benefits to alleviate LPS-induced ALI.

Apolipoprotein M increases the expression of vitamin D receptor mRNA in colorectal cancer cells detected with duplex fluorescence reverse transcription-quantitative polymerase chain reaction.

Apolipoprotein M (ApoM) and the vitamin D receptor (VDR) are apolipoproteins predominantly presenting in high-density lipoprotein (HDL) and a karyophilic protein belonging to the steroid­thyroid receptor superfamily, respectively. Previous studies have demonstrated that ApoM and VDR are associated with cholesterol metabolism, immune and colorectal cancer regulation. In order to investigate whether ApoM affected the expression of VDR in colorectal cancer cells, a single­tube duplex fluorescence reverse transcription­quantitative polymerase chain reaction (RT­qPCR) system was developed to simultaneously detect the mRNA levels of VDR and GAPDH in HT­29 cells overexpressing ApoM. The results demonstrated that the amplification products were confirmed as the specific fragment of VDR/GAPDH using the DNA sequencing instrument. The sensitivity, linear range, correlation coefficient, amplification efficiency, intra­assay and inter­assay coefficients of variation were 40 copies/µl, 4.00x101­4.00x105 copies/µl, 0.999, 92.42%, 0.09­0.34% and 0.32­0.65% for VDR, and 40 copies/µl, 4.00x101­4.00x105 copies/µl, 0.999, 98.07%, 0.19­0.43% and 0.40­0.75% for GAPDH, respectively. The results indicated that the expression of VDR mRNA was significantly higher in HT­29 cells overexpressing ApoM, compared with the negative control group (P<0.05). In conclusion, the current study successfully developed the single­tube duplex RT­qPCR to simultaneously detect VDR and GAPDH expression in colorectal cancer cells. The methodology results demonstrated that the duplex RT­qPCR system with high sensitivity and specificity could ensure the objectivity and credibility of the detection. The present study confirmed that ApoM significantly increased the expression of VDR in HT­29 cells. In addition, it was hypothesized that ApoM may be involved in antineoplastic activity via the upregulation of VDR expression, which may provide novel directions for the investigation of ApoM in cancer.

17ß-estradiol regulates the expression of apolipoprotein M through estrogen receptor α-specific binding motif in its promoter.

BACKGROUND: We have previously demonstrated that estrogen could significantly enhance expression of apolipoprotein M (apoM), whereas the molecular basis of its mechanism is not fully elucidated yet. To further investigate the mechanism behind the estrogen induced up-regulation of apoM expression. RESULTS: Our results demonstrated either free 17ß-estradiol (E2) or membrane-impermeable bovine serum albumin-conjugated E2 (E2-BSA) could modulate human apoM gene expression via the estrogen receptor alpha (ER-α) pathway in the HepG2 cells. Moreover, experiments with the luciferase activity analysis of truncated apoM promoters could demonstrate that a regulatory region (from-1580 to -1575 bp (-GGTCA-)) upstream of the transcriptional start site of apoM gene was essential for the basal transcriptional activity that regulated by the ER-α. With the applications of an electrophoresis mobility shift assay and a chromatin immunoprecipitation assay, we could successfully identify a specific ER-α binding element in the apoM promoter region. CONCULSION: In summary, the present study indicates that 17ß-estradiol induced up-regulation of apoM in HepG2 cells is through an ER-α-dependent pathway involving ER-α binding element in the promoter of the apoM gene.

Variability in development of the striped rice borer, Chilo suppressalis (Lepidoptera: Pyralidae), due to instar number and last instar duration.

The striped stem borer, Chilo suppressalis (Walker), is an important insect pest of rice which shows substantial variation in developmental duration among individuals. This variation is currently poorly characterized but it is important from a control perspective because pesticides can only target early sensitive instars. It is unclear whether there are key stages that determine the length of developmental duration of individuals and/or whether variation in instar number contributes to this variation. In this study, a laboratory population and a population recently established from the field were used to test variation in development time across instar stages. The duration of developmental time of C. suppressalis started to diverge from the 5th instar onward. Individuals pupated at the 5th, 6th, 7th or even 8th instar stage. In both populations, both the instar at which the larva pupated and the duration of the last larval instar stage determined total developmental time of an individual. There was little impact of the developmental time of early instars on total developmental duration or on instar number prior to pupation. Sex influenced the number of instars but not development time within this number. The biological and applied significance of uneven development in C. suppressalis are discussed.

Transition and Transversion Mutations Are Biased towards GC in Transposons of Chilo suppressalis (Lepidoptera: Pyralidae).

Transposons are often regulated by their hosts, and as a result, there are transposons with several mutations within their host organisms. To gain insight into the patterns of the variations, nucleotide substitutions and indels of transposons were analysed in Chilo suppressalis Walker. The CsuPLE1.1 is a member of the piggyBac-like element (PLE) family, which belongs to the DNA transposons, and the Csu-Ty3 is a member of the Ty3/gypsy family, which belongs to the RNA transposons. Copies of CsuPLE1.1 and Csu-Ty3 were cloned separately from different C. suppressalis individuals, and then multiple sequence alignments were performed. There were numerous single-base substitutions in CsuPLE1.1 and Csu-Ty3, but only a few insertion and deletion mutations. Similarly, in both transposons, the occurring frequencies of transitions were significantly higher than transversions (p ≤ 0.01). In the single-base substitutions, the most frequently occurring base changes were A→G and T→C in both types of transposons. Additionally, single-base substitution frequencies occurring at positions 1, 2 or 3 (pos1, pos2 or pos3) of a given codon in the element transposase were not significantly different. Both in CsuPLE1.1 and Csu-Ty3, the patterns of nucleotide substitution had the same characteristics and nucleotide mutations were biased toward GC. This research provides a perspective on the understanding of transposon mutation patterns.

Cloning of Two Acetylcholinesterase Genes and Analysis of Point Mutations Putatively Associated with Triazophos Resistance in Chilo auricilius (Lepidoptera: Pyralidae).

Acetylcholinesterase (AChE) is the target of organophosphate (OP) and carbamate insecticides. Mutations in the AChE gene (ace) leading to decreased insecticide susceptibility is the main resistance mechanism in insects. In this study, two Chilo auricilius acetylcholinesterase genes, designated as Caace1 and Caace2, were cloned using RT-PCR and RACE. Caace1 cDNA is 2534 bp, with ORF of 2082 bp, and it encodes an acetylcholinesterase 1 (CaAChE1) protein comprising a calculated 693 amino acid (aa) residues. Caace2 cDNA contains 2280 bp, with a full-length ORF of 1917 bp, encoding acetylcholinesterase 2 (CaAChE2) comprising a calculated 638 aa residues. At the aa level, CaAChE1 displays the highest similarity (97%) with the Chilo suppressalis AChE1, and CaAChE2 shows the highest similarity with the C. suppressalis AChE2 (99%). From the restriction fragment length polymorphism (RFLP) PCR (RFLP-PCR) analysis, one mutation in Caace1, similar to the ace1 mutation associated with triazophos resistance in C. suppressalis, was detected. Detailed examination of field populations of C. auricilius indicated this resistance mutation in C. auricilius is still quite infrequent. Based on the assay of AChE activity and RFLP-PCR testing, an individual that contains resistance mutation has lower AChE activities, while the individual that does not contain the resistance mutation has higher AChE activities. This study provides a basis for future investigations into the mechanism of OP resistance in C. auricilius, as well as a guidance for C. auricilius control with reasonable choice of pesticides.