Three-dimensional reconstruction of insect chemosensory sensillum.

The olfactory system is involved in food and mate recognition in insects. However, 3D structures of chemosensory sensilla in insects are unexplored yet. Here, the internal structures of an olfactory sensillum on the antenna of the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae), one of the most important rice pests, are examined and imaged using focused ion beam scanning electron microscopy. Based on these images, a 3D structure is reconstructed in this study. We find that the trichoid olfactory sensillum possesses a multiporous wall encircling a lumen with one sensory cell. Besides, there are three accessory cells (ACs) and a glia cell with different cell contents surrounding the sensory cell. The abundant tubular membrane structures in the tormogen cell suggest its role in secreting proteins like odorant binding proteins into the receptor lymph, while three auxiliary cells with simpler cellular content closely enfold the sensory cell, probably to prevent leaking of the receptor lymph into the surrounding epidermis. In the sensory cell, the microtubules and two tandem basal bodies at the base of the microtubules are also reconstructed. They are considered as a propulsive engine to ensure dendrite vibration or spinning in the receptor lymph, so that the proteins and odorant molecules move faster in the receptor lymph, which improves recognition of environmental odors and enables the insect to immediately respond to this information.

VAPB-mediated ER-targeting stabilizes IRS-1 signalosomes to regulate insulin/IGF signaling.

The scaffold protein IRS-1 is an essential node in insulin/IGF signaling. It has long been recognized that the stability of IRS-1 is dependent on its endomembrane targeting. However, how IRS-1 targets the intracellular membrane, and what type of intracellular membrane is actually targeted, remains poorly understood. Here, we found that the phase separation-mediated IRS-1 puncta attached to endoplasmic reticulum (ER). VAPB, an ER-anchored protein that mediates tethers between ER and membranes of other organelles, was identified as a direct interacting partner of IRS-1. VAPB mainly binds active IRS-1 because IGF-1 enhanced the VAPB-IRS-1 association and replacing of the nine tyrosine residues of YXXM motifs disrupted the VAPB-IRS-1 association. We further delineated that the Y745 and Y746 residues in the FFAT-like motif of IRS-1 mediated the association with VAPB. Notably, VAPB targeted IRS-1 to the ER and subsequently maintained its stability. Consistently, ablation of VAPB in mice led to downregulation of IRS-1, suppression of insulin signaling, and glucose intolerance. The amyotrophic lateral sclerosis (ALS)-derived VAPB P56S mutant also impaired IRS-1 stability by interfering with the ER-tethering of IRS-1. Our findings thus revealed a previously unappreciated condensate-membrane contact (CMC), by which VAPB stabilizes the membraneless IRS-1 signalosome through targeting it to ER membrane.

Phase separation of insulin receptor substrate 1 drives the formation of insulin/IGF-1 signalosomes.

As a critical node for insulin/IGF signaling, insulin receptor substrate 1 (IRS-1) is essential for metabolic regulation. A long and unstructured C-terminal region of IRS-1 recruits downstream effectors for promoting insulin/IGF signals. However, the underlying molecular basis for this remains elusive. Here, we found that the C-terminus of IRS-1 undergoes liquid-liquid phase separation (LLPS). Both electrostatic and hydrophobic interactions were seen to drive IRS-1 LLPS. Self-association of IRS-1, which was mainly mediated by the 301-600 region, drives IRS-1 LLPS to form insulin/IGF-1 signalosomes. Moreover, tyrosine residues of YXXM motifs, which recruit downstream effectors, also contributed to IRS-1 self-association and LLPS. Impairment of IRS-1 LLPS attenuated its positive effects on insulin/IGF-1 signaling. The metabolic disease-associated G972R mutation impaired the self-association and LLPS of IRS-1. Our findings delineate a mechanism in which LLPS of IRS-1-mediated signalosomes serves as an organizing center for insulin/IGF-1 signaling and implicate the role of aberrant IRS-1 LLPS in metabolic diseases.

Chitin synthase 1 and five cuticle protein genes are involved in serosal cuticle formation during early embryogenesis to enhance eggshells in Nilaparvata lugens.

Many holo- and hemimetabolous insects enhance their eggshells during embryogenesis by forming a serosal cuticle (SC). To date, scholarly understanding of the SC composition and SC-related gene functions has been limited, especially for hemimetabolous insects. In this study, we initially performed transmission electron microscopic (TEM) observation and chitin staining of the SC in Nilaparvata lugens, a hemimetabolous rice pest known as the brown planthopper (BPH). We confirmed that the SC was a chitin-rich lamellar structure deposited gradually during the early embryogenesis. Parental RNA interference (RNAi) against Nilaparvata lugens chitin synthase 1 (NlCHS1) in newly emerged and matured females resulted in decreases of egg hatchability by 100% and 76%, respectively. Ultrastructural analyses revealed loss of the lamellar structure of the SC in dsNlCHS1-treated eggs. According to temporal expression profiles, five cuticle protein coding genes, NlugCpr1/2/3/8/90, were specifically or highly expressed during the SC formation period, and NlugCpr1/2/3/90 were further detected in 72 h eggshells extract by ultra-performance liquid chromatography-tandem mass spectrometry/mass spectrometry. NlugCpr2/3/90 were likely three SC-specific cuticle proteins. TEM observations of the SC following parental RNAi against NlugCpr1/2/3/8/90 demonstrated that NlugCpr3/8/90 were essential for SC formation. The study provided an understanding of the SC formation process and SC-related cuticle proteins in BPHs, which offer potential targets for pest control in the egg stage as well.

Three-dimensional reconstruction of a whole insect reveals its phloem sap-sucking mechanism at nano-resolution.

Using serial block-face scanning electron microscopy, we report on the internal 3D structures of the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) at nanometer resolution for the first time. Within the reconstructed organs and tissues, we found many novel and fascinating internal structures in the planthopper such as naturally occurring three four-way rings connecting adjacent spiracles to facilitate efficient gas exchange, and fungal endosymbionts in a single huge insect cell occupying 22% of the abdomen volume to enable the insect to live on plant sap. To understand the muscle and stylet movement during phloem sap-sucking, the cephalic skeleton and muscles were reconstructed in feeding nymphs. The results revealed an unexpected contraction of the protractors of the stylets and suggested a novel feeding model for the phloem sap-sucking.

Since the 19^th century, scientists have been investigating how the organs of insects are shaped and arranged. However, classic microscopy methods have struggled to image these small, delicate structures. Understanding how the organs of insects are configured could help to identify new methods for controlling pests, such as chemicals that target the mouthparts that some insects use to feed on plants. Most insects that feed on the sap of plants suck out the nutrient via their stylet bundle ­ a thin, straw-like structure surrounded by a sheath called the labium. As well as drying out the plant and damaging its tissues, the stylet bundle also allows the insect to transmit viruses that cause further harm. To investigate these mouthparts in more detail, Wang, Guo et al. used a method called SBF-SEM to determine the three-dimensional structure of one of the most destructive pests of rice crops, the brown planthopper. In this technique, a picture of the planthopper was taken every time a thin slice of its body was removed. This continuous slicing and re-imaging generated thousands of images that were compiled into a three-dimensional model of the brown planthopper's whole body and internal organs. Previously unknown features emerged from the reconstruction, including a huge cell in the planthopper's abdomen which is full of fungi that provide the nutrients absent in plants. Next, Wang, Guo et al. used this technique to see how the muscles in the labium and surrounding the stylet move by imaging planthoppers that were frozen at different stages of the feeding process. This revealed that when brown planthoppers bow their heads to eat, the labium compresses and pushes out the stylet, allowing it to pierce deeper into the plant. This is the first time that the body of such a small insect has been reconstructed three-dimensionally using SBF-SEM. Furthermore, these findings help explain how brown planthoppers and other sap-feeding insects insert their stylet and damage plants, potentially providing a stepping stone towards identifying new strategies to stop these pests from destroying millions of crops.

Three-dimensional architecture of a mechanoreceptor in the brown planthopper, Nilaparvata lugens, revealed by FIB-SEM.

Trichoid sensilla are the most common mechanoreceptors in insects; depending on their distribution, they can act as either exteroceptors or proprioceptors. In this study, the internal structure of the trichoid sensillum from Nilaparvata lugens was studied, using focused ion beam scanning electron microscopy (FIB-SEM). We reconstructed a three-dimensional (3D) model derived from the FIB-SEM data set. The model displayed characteristic mechanosensory sensilla components, including a hair inserted in the socket, a dendrite going through the laminated cuticle, and an electron-dense tubular body at the dendrite terminal. The detailed 3D model showed the relationship between the microtubules within the tubular body and those outside of the tubular body. We also found an autocellular junction in the tormogen cell, indicating that the tormogen cell grows around the dendrite sheath to form a hollow column shape during sensilla morphogenesis.

The flightin gene is necessary for the emission of vibrational signals in the rice brown planthopper (Nilaparvata lugens Stǻl).

In duet-based courtship, species- and sex-specific vibrational signals enable animals to identify the species and sex of the singer and also provide the necessary information with which to locate a partner. Substrate-borne communication has been described in a wide variety of insects. Here, we focus on the gene necessary for the emission of male vibrational signals and whether the male song fulfills such a functional role in the mating system of the brown planthopper (BPH, Nilaparvata lugens). We generated mute BPH adult males via RNA interference (RNAi) of the flightin gene, which encodes a myosin-binding protein expressed exclusively in the dorsal longitudinal muscle (DLM) in the basal two abdominal segments used for driving the vibration of the male-specific tymbal structure in short-winged (brachypterous) BPH adults. Transmission electron microscopy (TEM) observation showed that flightin knockdown disrupted the normal sarcomere structure of the abdominal DLM. No courtship song could be detected in the brachypterous males after RNAi treatment. Behavior and competition trials showed that the lack of male courtship songs prolonged copulation latency and even caused female rejection. Unexpectedly, the mute males exhibited greater competitiveness when competing against normal males.

High expression of the ANKRD49 protein is associated with progression and poor prognosis of gastric cancer.

BACKGROUND: Gastric cancer is one of the most common malignant tumours. Identifying novel genes that govern the development of gastric cancer will help to elucidate its molecular mechanisms and find novel biomarkers. METHODS: Expression of the ANKRD49 protein was assessed by immunohistochemical analysis of tissue microarrays containing 92 sets of human gastric cancer specimens with adjacent non-cancerous tissue. Associations between ANKRD49 levels and clinicopathological characteristics of the patient were investigated. The correlation between ANKRD49 expression and patient survival was analysed by the Kaplan-Meier method. RESULTS: The results revealed that the expression level of the ANKRD49 protein in gastric cancer was significantly upregulated and correlated with the tumour size, tumour-node-metastasis (TNM) stage, histological grade, depth of invasion, vessel invasion, lymph node metastasis and distant metastasis. The mean survival time of patients with low expression levels of ANKRD49 was significantly longer than that of patients with high expression levels of ANKRD49. Multivariate Cox regression analysis demonstrated that the ANKRD49 protein expression level was an independent prognostic indicator for the survival rate of patients with gastric cancer. CONCLUSION: The results of the present study highlighted an important role of the ANKRD49 protein in the progression of gastric cancer. The ANKRD49 protein could act as a potential biomarker for prognosis evaluation of gastric cancer and may be used as a molecular target for gastric cancer treatment.

Facile Method and Novel Dielectric Material Using a Nanoparticle-Doped Thermoplastic Elastomer Composite Fabric for Triboelectric Nanogenerator Applications.

The trends toward flexible and wearable electronic devices give rise to the attention of triboelectric nanogenerators (TENGs) which can gather tiny energy from human body motions. However, to accommodate the needs, wearable electronics are still facing challenges for choosing a better dielectric material to improve their performance and practicability. As a kind of synthetic rubber, the thermoplastic elastomer (TPE) contains many advantages such as lightweight, good flexibility, high tear strength, and friction resistance, accompanied by good adhesion with fabrics, which is an optimal candidate of dielectric materials. Herein, a novel nanoparticle (NP)-doped TPE composite fabric-based TENG (TF-TENG) has been developed, which operates based on the NP-doped TPE composite fabric using a facile coating method. The performances of the TENG device are systematically investigated under various thicknesses of TPE films, NP kinds, and doping mass. After being composited with a Cu NP-doped TPE film, the TPE composite fabric exhibited superior elastic behavior and good bending property, along with excellent flexibility. Moreover, a maximum output voltage of 470 V, a current of 24 µA, and a power of 12 mW under 3 MΩ can be achieved by applying a force of 60 N on the TF-TENG. More importantly, the TF-TENG can be successfully used to harvest biomechanical energy from human body and provides much more comfort. In general, the TF-TENG has great application prospects in sustainable wearable devices owing to its lightweight, flexibility, and high mechanical properties.

Effect of Shuwei Decoction () on rats with functional dyspepsia.

OBJECTIVE: To investigate the effects of Shuwei Decoction (, SWD) on gastric emptying, serum stem cell factor (SCF), the content of serum nitric oxide (NO), and structure change of interstitial cells of Cajal (ICC) in functional dyspepsia (FD) rats. METHODS: Sixty Sprague Dawley rats were randomly divided into 6 groups: blank group (group A), model group (group B), mosapride group (group C), Muxiang Shunqi Pill (, MSP) group (group D), SWD low-dose group (group E), and SWD high-dose group (group F), 10 rats in each group. FD rat model was established by clasping rats' tails for 7 days, except the group A. After 3 days, group A and group B were given distilled water, and the medicated rats were given corresponding medicine for 14 days. The gastric emptying, structure change of ICC in gastric antrum by transmission electron microscope, the content of serum NO by nitrate reductant and SCF by enzyme linked immunosorbent assay were observed. RESULTS: Compared with group A, the rats in group B delayed gastric emptying, serum SCF decreased, serum NO increased (P <0.05). Compared with group B, the rats in groups D, E and F were improved on gastric emptying, obviously increased on serum SCF, decreased on serum NO (P <0.05), and structure change of ICC in gastric antrum improved. Compared with group B, structure change of ICC of group E after treatment was improved and was closed to group A. CONCLUSION: SWD recovered gastrointestinal motility of FD, possibly by regulating the levels of serum NO and SCF, and improving the structure of ICC in gastric antrum.

[Prognostic associations of preoperative plasma levels of fibrinogen and D-dimer after curative resection in patients with colorectal cancer].

OBJECTIVE: To explore the associations of preoperative plasma levels of fibrinogen and D-dimer with clinicopathologic parameters and overall survival in colorectal cancer patients after curative resection. METHODS: From January 2002 to December 2003, a total of 341 colorectal cancer patients underwent curative resection. And their relevant clinical data were reviewed. The median age was 58 years (range: 23 - 90 years) and the median follow-up period was 64 months (range: 5 - 89 months). The preoperative plasma levels of fibrinogen and D-dimer were examined, the correlation of clinicopathologic findings and overall survival was analyzed. A Log-rank test was used for univariate analysis and a Cox regression model for multivariate analysis. RESULTS: The preoperative plasma levels of fibrinogen and D-dimer were (3.7 ± 0.7) g/L and (0.49 ± 0.18) mg/L respectively. Elevated plasma levels of fibrinogen were associated with advanced tumor stage (P = 0.008), venous invasion (P = 0.006), postoperative distant metastases (P < 0.01) and lymph node involvement (P = 0.001), but not with histologic grade (P = 0.232), and invasion depth (P = 0.253). The overall survival is 64.5% (220/341). Elevated plasma levels of D-dimer were associated with advanced tumor stage (P = 0.013), invasion depth (P = 0.007) and lymph node involvement (P = 0.001), but not with histologic grade (P = 0.082), venous invasion (P = 0.746) or postoperative distant metastases (P = 0.131). Multivariate analysis showed that preoperative plasma levels of fibrinogen (P = 0.029), histologic grade (P = 0.001), and lymph node involvement (P = 0.001) were independent prognostic factors. CONCLUSIONS: High preoperative plasma levels of fibrinogen and D-dimer are associated with clinicopathologic parameters. And a high preoperative plasma level of fibrinogen is associated with distant metastases and poor prognosis after curative resection in colorectal cancer patients.

[Study on four natures of six flavor Chinese materia medica as rhizoma coptidis and radix aconiti lateralis praeparata etc].

OBJECTIVE: To study on four natures of six flavor Chinese meteria medica as rhizoma coptidis, radix scutellariae, radix aconiti lateralis praeparata, rhizoma zingiberis, rhizoma dioscoreae and radix et rhizoma glycyrrhizae. METHODS: To determine the biological enthalpy of extracts of Chinese meteria medica, rats' metabolites and excrement after feeding the extract of medicines and the standard substance of basic by the oxygen bomb calorimeter. RESULTS: The biological enthalpy of rhizoma coptidis, radix scutellariae, radix aconiti lateralis praeparata, rhizoma zingiberis, rhizoma dioscoreae and radix et rhizoma glycyrrhizae were (3006.02 +/- 201.51)J/g, (1592.41 +/- 404.41)J/g, -(433.10 +/- 64.43)J/g, -(665.72 +/- 198.59)J/g, -(18.41 +/- 50.08)J/g, (29.55 +/- 55.13)J/g respectively. According to the results, rhizoma coptidis and radix scutellariae showed cold properties, whereas those of radix aconiti lateralis praeparata and rhizoma zingiberis were opposite as well as rhizoma dioscoreae and radix et rhizoma glycyrrhizae were neutral drugs. CONCLUSION: The four natures of Chinese meteria medica presente in traditional Chinese pharmacology could be determined by the mathematical model of four natures.

[Impact on the model of rat osteoarthritis of jingu tablet].

OBJECTIVE: To observe the influence of Jingu tablet (JGT) on the development and repair of osteoarthritis (OA). METHOD: The admixture of 4% papain and 0.3 mol x L(-1) cysteine was injected into the rat's knee joint to make the model of rat OA, and distilled water, Gucining Capsule and JGT was given ig simultaneously to treat for 4 weeks in succession, and then animals were killed to measure every index. RESULT: JGT could obviously improve the scope of activities of knee joint. There were significant differences between every dosage group and model group. In every dosage group, JGT could suppress the swelling of thickness of slippery membrane of joint, alleviate the inflammation symptoms of OA and obviouslical improve the pathologicol changes of slippery membrane and cartilage. JGT could also obviously reduce the content of MDA of slippery membrane and lighten the degree of cell damage. CONCLUSION: JGT can lighten the retrograde affection of joint cartilage, obviously suppress the slippery membrane's inflammation and alleviate the scathing degree of cell. Therefore JGT has definite remedial effect to OA.

[Experimental research of songzhi pills on inducement of interferon in mice and rats].

OBJECTIVE: To develop a new drug of treating the hepatitis C virus by studing the mechanisms of songzhi pills. METHOD: The four-wee old mice and two-month old rats were chosen to induce interferon. RESULT: The contents of interferon among the groups treated with songzhi pills were significantly higher than those of the normal group and the model group (P < 0.01), CONCLUSIONS: Songzhi pills may have the function of inducing interferon.