Tissue localization and regulation by juvenile hormone of human allergen Bla g 4 from the German cockroach, Blattella germanica (L.)

The German cockroach, Blattella germanica (L.), produces several potent protein aeroallergens, including Bla g 4, a approximately 20 kDa lipocalin. RT-PCR, Northern analyses and in situ hybridization showed that Bla g 4 is expressed only in the adult male reproductive system. Western blotting and ELISA with rBla g 4 antiserum detected immunoreactivity in the utricles and the conglobate gland, but not in other tissues of the male reproductive system. The Bla g 4 protein content of males increased from adult emergence to day 14, but during copulation Bla g 4 was depleted in the male and transferred to the female within the spermatophore. Topical application of juvenile hormone III stimulated Bla g 4 production by both conglobate gland and utricles.     

Functional analysis and molecular characterization of two acetylcholinesterases from the German cockroach,Blattella germanica

Two acetylcholinesterases (AChEs; BgAChE1 and BgAChE2) from Blattella germanica were functionally expressed using the baculovirus system. Kinetic analysis demonstrated that BgAChE2 had higher catalytic efficiency but lower substrate specificity than BgAChE1. With the exceptions of paraoxon and propoxur, BgAChE1 was generally less sensitive to inhibitors than BgAChE2. Western blot analysis using anti‐BgAChE antibodies revealed that BgAChE1 was far more abundant in all examined tissues compared to BgAChE2, which is only present in the central nervous system. Both BgAChEs existed in dimeric form, covalently connected via a disulphide bridge under native conditions. Most fractions of BgAChE1 had a glycophosphatidylinositol (GPI) anchor, but a small fraction comprised a collagen‐like tail. BgAChE2 appeared to have a collagen‐GPI‐fused tail. Based on the kinetic and molecular properties, tissue distribution and abundance, BgAChE1 was confirmed to play a major role in postsynaptic transmission.     

RNA interference and functional characterization of a tergal gland alpha amylase in the German cockroach,Blattella germanica L.

German cockroach males possess tergal glands that secrete a combination of oligosaccharides, lipids and proteins. Four major proteins occur in the secretion, with one being the 63 kDa alpha‐amylase Blattella germanica Tergal Gland protein‐1 (BGTG‐1). Denaturing and starch gel electrophoresis coupled with peptide sequencing verified amylase activity for the BGTG‐1 protein. BGTG‐1 gene expression profiles were determined by using quantitative real‐time PCR to compare messenger RNA abundance among isolated tissues of males, females and gravid females. Differences in BGTG‐1 gene expression occurred among male tissues, with tergal gland tissue showing the highest expression. Tissues of nongravid and gravid females had significantly lower expression in comparison with male tergal glands (gravid females lowest). RNA interference (RNAi) was used to silence BGTG‐1 gene expression by injecting BGTG‐1 homologous double‐stranded RNA (dsRNA) into male cockroaches. Groups injected with BGTG‐1 dsRNA showed ～90% lower BGTG‐1 gene and protein expression compared to controls, which correlated with lower amylase activity in colorimetric assays. However, behavioural assays comparing precopulatory behaviour and mating success between RNAi and control males did not reveal differences. These results connect amylase gene expression and activity in tergal gland tissue but suggest other factors, such as other tergal gland components, may contribute more strongly to mating success.     

Cloning of two novel P450 cDNAs from German cockroaches, Blattella germanica (L.): CYP6K1 and CYP6J1

Two novel P450 cDNAs, CYP6K1 and CYP6J1, were isolated from German cockroaches, Blattella germanica (L). Both CYP6K1 and CYP6J1 are typical microsomal P450s and their deduced amino acid sequences share a number of common characteristics with other members of the P450 superfamily. Both CYP6K1 and CYP6J1 showed the highest per cent identity (based on the deduced amino acid sequence) to CYP6L1 from B. germanica and CYP6H1, a putative ecdysone 20‐hydroxylase from Locusta migratoria. Using a CYP6K1 probe, two mRNA signals (~2.5 and ~2.1 kb) were detected in all life stages. Both signals were just detectable in the eggs and became stronger in later instars. The strongest signals were detected in the fifth and sixth instars as well as in adults. These two bands were also detected in the abdomens and in the remainder of bodies of both male and female adults. Southern blots suggest the two mRNA bands detected in the Northern blot might be a result of alternative splicing. No signal could be detected at any life stage using the CYP6J1 probe, suggesting that CYP6J1 was expressed at a low level.     

Characterization of BGTG-1, a tergal gland-secreted alpha-amylase, from the German cockroach, Blattella germanica (L.)

The protein fraction of the German cockroach, Blattella germanica (L.), tergal gland secretion was examined. SDS-PAGE separation of proteins present in B. germanica tergal gland secretion revealed a tergal gland-secreted protein, BGTG-1, at approximately 63 kDa. BGTG-1 first appeared in tergal gland secretion at 2 days postimaginal moult and the amount of protein observed increased through day 5. A 2051 bp cDNA sequence, bgtg-1, was obtained by RACE polymerase chain reaction and contains a 1494 bp ORF encoding a predicted protein of 498 amino acids. In a Northern hybridization experiment using total RNA from B. germanica tergal gland tissue, a (32)P-labelled bgtg-1 probe hybridized to an RNA approximately 2000 bp and confirmed the 2051 bp cDNA size obtained by RACE PCR. Using the BLASTx sequence similarity search tool, the top match to the bgtg-1 ORF was found to be an alpha-amylase from Drosophila kikkawai (e-value = 1 x 10(-178)). Alignment of the bgtg-1 deduced protein sequence with alpha-amylases from fruit fly, Drosophila melanogaster, honey bee, Apis mellifera (L.) and yellow mealworm, Tenebrio molitor (L.), revealed conserved residues throughout the ORF and sequence identities ranging from 58.4 to 58.2%. Using a gel-based assay, degradation of starch by native BGTG-1 was demonstrated in vitro and we propose that BGTG-1 may be involved in processing phagostimulatory sugars present in B. germanica tergal gland secretion.     

RNA interference-mediated gene silence of the NR1 subunit of the NMDA receptor by subcutaneous injection of vector-encoding short hairpin RNA reduces formalin-induced nociception in the rat

There is accumulating evidence to implicate the importance of N-methyl-d-aspartate (NMDA) receptors to the induction and maintenance of central sensitization during pain states. However, the use of NMDA receptor antagonists can often be limited by serious central nervous system side effects. The development of peripheral NMDA receptor antagonists that do not interfere with central glutamate processing can avoid adverse effects of the central nervous system. RNA interference is an evolutionarily conserved mechanism for silencing gene expression in which a targeted mRNA is degraded by a double-stranded RNA sequence known as a small interfering RNA (siRNA). siRNAs can be derived from short hairpin (sh) RNAs, which can be expressed from plasmids or viral vectors to achieve long-term gene silencing. In this study, we examined the effect of gene silence and antinociception on formalin-induced pain by subcutaneous injection of vector-encoding shRNA targeting the NR1 subunit of the NMDA receptor. The results revealed that subcutaneous injection of vector-expressing NR1 shRNA could effectively diminish the nociception induced by formalin stimuli and inhibit gene expression of NR1 evidenced by a decreased level of mRNA and protein. The effect of antinociception and inhibition of NR1 expression by NR1 shRNA persisted for about 14 days. The data suggest that NR1 shRNA has therapeutic potential to provide long-term treatment of pathological pain that is induced or maintained by peripheral nociceptor activity.     

RNA干扰质粒对胰腺癌细胞系Panc-1原癌基因AKT2表达的影响

  目的  探讨RNA干扰质粒抑制胰腺癌细胞系Panc-1原癌基因AKT2的表达对胰腺癌细胞生长和凋亡的影响, 并初步探讨其作用机制。  方法  选择胰腺癌细胞系Panc-1, 构建特异性抑制AKT2表达的RNA干扰质粒, 瞬时和稳定转染胰腺癌细胞, 采用MTT法及软琼脂克隆形成实验检测胰腺癌细胞生长能力, Heochst染色及Annexin V-FITC/PI染色法检测细胞凋亡情况, 通过Western blot方法检测凋亡蛋白caspase-3表达; 并进行裸鼠移植瘤体内转染实验。  结果  采用RNA干扰质粒沉默胰腺癌细胞系Panc-1原癌基因AKT2, 能够有效抑制胰腺癌细胞Panc-1体外生长能力、促进细胞凋亡, 诱导凋亡激酶caspase-3的表达; 动物体内实验结果显示, 干扰质粒能够有效抑制胰腺癌细胞系Panc-1在动物体内的成瘤能力。  结论  RNA干扰质粒抑制原癌基因AKT2表达, 可有效抑制胰腺癌细胞生长, 促进凋亡, 针对原癌基因AKT2的基因治疗对胰腺癌具有重要的潜在应用价值。     

The involvement of clathrin‐mediated endocytosis and two Sid‐1‐like transmembrane proteins in double‐stranded RNA uptake in the Colorado potato beetle midgut

RNA interference (RNAi) is a powerful tool in entomology and shows promise as a crop protection strategy, but variability in its efficiency across different insect species limits its applicability. For oral uptake of the double‐stranded RNA (dsRNA), the RNAi trigger, two different mechanisms are known: systemic RNA interference deficient‐1 (Sid‐1) transmembrane channel‐mediated uptake and clathrin‐mediated endocytosis. So far, a wide range of experiments has been conducted, confirming the involvement of one of the pathways in dsRNA uptake, but never both pathways in the same species. We investigated the role of both pathways in dsRNA uptake in the Colorado potato beetle, Leptinotarsa decemlineata, known to have an efficient RNAi response. Through RNAi‐of‐RNAi experiments, we demonstrated the contribution of two different sid‐1‐like (sil) genes, silA and silC, and clathrin heavy chain and the 16kDa subunit of the vacuolar H⁺ ATPase (vha16), elements of the endocytic pathway, to the RNAi response. Furthermore, the sid‐1‐like genes were examined through phylogenetic and hydrophobicity analysis. This article reports for the first time on the involvement of two pathways in dsRNA uptake in an insect species and stresses the importance of evaluating both pathways through a well‐devised reporter system in any future experiments on cellular dsRNA uptake.     

RNA干扰骨髓基质细胞衍生因子表达对共培养Jurkat细胞增殖及凋亡的影响

目的探讨阻抑骨髓基质细胞衍生因子(SDF1)表达对与其共培养的Jurkat细胞增殖、凋亡的影响。方法脂质体介导SDF1特异性RNA干扰质粒转染培养的急性白血病骨髓基质细胞,G418筛选阳性克隆(A组),采用ELISA法检测SDF1表达变化;与Jurkat细胞共培养,绘制生长曲线并计算倍增时间,用流式细胞术检测细胞周期,末端脱氧核苷酸转移酶介导的dUTP缺失末端标记(TUNEL)法检测细胞凋亡,免疫细胞化学检测增殖细胞核抗原(PCNA)、Bcl2、Bax、Fas、FasL表达。以未转染急性白血病骨髓基质细胞(B组)及正常骨髓基质细胞(C组)作为对照。结果A组骨髓基质细胞培养上清SDF1含量为(384±41)pg/ml,较B组[(2474±271)pg/ml]、C组[(1324±154)pg/ml]明显降低。与之共培养的Jurkat细胞,A组与B组、C组比较,细胞增殖速度减缓,倍增时间延长(A组42h,B组29h,C组33h);细胞周期分析G0/G1期细胞比例增多[A组(28.47±2.39)%,B组(19.43±2.80)%,C组(27.15±2.07)%],S期细胞减少[A组(25.57±1.90)%,B组(74.48±3.23)%,C组(60.99±2.33)%],G2/M期细胞增多[A组(45.96±3.24)%,B组(6.09±1.96)%,C组(11.86±1.98)%];细胞凋亡率增加[A组(15.2±0.8)%,B组(5.4±0.7)%,C组(9.5±0.4)%];PCNA、Bcl2、Fas表达减少,Bax、FasL表达增多。结论阻抑SDF1表达在一定程度上抑制与骨髓基质细胞共培养的Jurkat细胞的增殖活性,并促进其凋亡。     

Age- and division-of-labour-dependent differential expression of a novel non-coding RNA, Nb-1, in the brain of worker honeybees, Apis mellifera L.

To elucidate the molecular mechanisms underlying honeybee social behaviours, we identified a novel gene, Nb-1 , whose expression in the worker brain changes according to the age-dependent division of labour in normal colonies. The open reading frames contained in the Nb-1 cDNA were not conserved in the homologue of a related species, suggesting that the Nb-1 gene product is a non-coding RNA. The distribution of Nb-1- expressing cells partially overlapped that of octopamine-immunoreactive cells and neurosecretory cells, the latter of which are involved in the synthesis and secretion of juvenile hormone (JH). Octopamine and JH control worker task transition, and thus Nb-1 might be involved in task transition through the modulation of octopamine/JH synthesis and secretion.     

Evaluating the potency of blood long noncoding RNA PVT1 as candidate biomarker reflecting inflammation,multiple organ dysfunction,and mortality risk in sepsis patients

ObjectiveLong noncoding RNA plasmacytoma variant translocation 1 (lnc‐PVT1) promotes septic inflammation and organ injuries via multiple ways, while its clinical engagement in sepsis management is indistinct. This study aimed to investigate its relationship with inflammation, multiple organ dysfunction, and mortality risk in sepsis patients.MethodsSepsis patients and age‐/gender‐matched healthy controls were enrolled; their lnc‐PVT1 expression in plasma were detected by RT‐qPCR. For sepsis patients only, the inflammatory cytokine levels (tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, and IL‐17A) in plasma were detected by ELISA. According to the survival data during 28‐day follow‐up, sepsis patients were divided into sepsis survivors and sepsis deaths.ResultsLnc‐PVT1 expression was increased in sepsis patients (N = 157) compared with healthy controls (N = 80) (p < 0.001). In sepsis patients, lnc‐PVT1 was linked with higher acute physiology and chronic health evaluation II (APACHEII) score (p = 0.001), total sequential organ failure assessment (SOFA) score, and its most subitems (SOFA‐respiratory system, SOFA‐coagulation, SOFA‐liver, SOFA‐cardiovascular system, and SOFA‐renal system scores) (all p < 0.01), but not SOFA‐nervous system score (p = 0.091); it did not relate to primary infection sites either (p = 0.204). Furthermore, lnc‐PVT1 correlated with increased C‐reactive protein, TNF‐α, IL‐1β, and IL‐17 in sepsis patients (all p < 0.01). Additionally, lnc‐PVT1 expression was higher in sepsis deaths than that in sepsis survivors (p < 0.001), following receiver‐operating characteristic curve disclosed that lnc‐PVT1 predicted 28‐day septic mortality risk (area under the curve: 0.789, 95% confidence interval: 0.702–0.875).ConclusionCirculating lnc‐PVT1 exhibits the potential as a biomarker in sepsis patients to inform inflammation, multiple organ dysfunction, and mortality risk.