Mouse lung-adapted mutation of E190G in hemagglutinin from H5N1 influenza virus contributes to attenuation in mice

The highly pathogenic H5N1 avian influenza virus is one of the greatest influenza pandemic threats since 2003. The association of the receptor binding domain (RBD) with the virulence of influenza virus is rarely addressed, particularly of H5N1 influenza viruses. In this study, BALB/c mice were intranasally infected with A/Vietnam/1194/2004 (VN1194, H5N1). The mouse lung-adapted variants were isolated and the mutation of E190G (H3 numbering) in the RBD was recognized. The recombinant virus, rVN-E190G carrying E190G in hemagglutinin (HA) was designed and rescued using reverse genetics techniques. The receptor binding activity, growth curve and pathogenicity in mice of the rVN-E190G were investigated. Results demonstrated that rVN-E190G virus increased the binding avidity to α2,6 SA (sialic acid) and reduced the affinity to α2,3 SA, meanwhile weakened the viral replication in vitro. Moreover, the virulence assessment demonstrated that rVN-E190G was attenuated in mice. These results indicated that the mutation E190G in HA decreases H5N1 viral replication in vitro and significantly attenuates virulence in vivo. These findings identify one of the determinants in RBD which can be associated with H5N1 virulence in mice.

Spectroscopic study of Gd nanostructures quantum confined in Fe corrals

Low dimensional nanostructures have attracted attention due to their rich physical properties and potential applications. The essential factor for their functionality is their electronic properties, which can be modified by quantum confinement. Here the electronic states of Gd atom trapped in open Fe corrals on Ag(111) were studied via scanning tunneling spectroscopy. A single spectroscopic peak above the Fermi level is observed after Gd adatoms are trapped inside Fe corrals, while two peaks appear in empty corrals. The single peak position is close to the higher energy peak of the empty corrals. These findings, attributed to quantum confinement of the corrals and Gd structures trapped inside, are supported by tight-binding calculations. This demonstrates and provides insights into atom trapping in open corrals of various diameters, giving an alternative approach to modify the properties of nano-objects.

Molecular characterization and hormonal regulation of tissue inhibitor of metalloproteinase 1 in goat ovarian granulosa cells

Tissue inhibitor of metalloproteinase 1 (TIMP1) belongs to a group of endogenous inhibitors that control the activity of matrix metalloproteinases and other metalloproteinases. TIMP1 is ubiquitously expressed and implicated in many physiological and pathologic processes. In this study, the full-length complementary DNA of goat (Capra hircus) Timp1 was cloned from adult goat ovary for the first time to better understand the regulatory role of TIMP1. The putative TIMP1 protein shared a high amino acid sequence identity with other species. Real-time polymerase chain reaction results showed that Timp1 was widely expressed in adult goat tissues, and messenger RNA expression was higher in the ovary than in other tissues; meanwhile, increasing expression of Timp1 was also discovered during the process of follicle growth and corpus luteum. We then investigated Timp1 expression patterns in different types of ovarian follicular cells from goats. In small or large antral follicles, Timp1 expression was higher (P < 0.05) in theca cells than in granulosa cells, cumulus cells, and oocytes. Increasing expression of Timp1 in theca and granulosa cells was observed as the variation of the follicle size. Immunohistochemical analyses further revealed the presence of the TIMP1 proteins in follicles at all antral stages of development. The most intense staining for TIMP1 was observed in the theca cells and granulosa cells of large antral follicles and corpus luteum. Timp1 was highly (P < 0.05) induced in granulosa cells in vitro after treatment with the luteinizing hormone agonist, human chorionic gonadotropin. Treatments with forskolin, phorbol 12-myristate 13-acetate, or phorbol 12-myristate 13-acetate + forskolin could also stimulate Timp1 messenger RNA expression. The effects of human chorionic gonadotropin were reduced (P < 0.05) by the inhibitors of protein kinase A, protein kinase C, MAPK kinase, or p38 kinase, indicating that Timp1 expression could be adjusted by luteinizing hormone-initiated activation of these signaling mediators. Our results suggested that TIMP1 may be involved in regulating ovarian follicle development and ovulation.

An improved technique for cerebrospinal fluid collection of cisterna magna in Rhesus monkeys

BACKGROUND

Currently-used cerebellomedullary cistern puncture method for collecting cerebrospinal fluid (CSF) from monkeys is simple, inexpensive, and practical, but with high risk for brainstem injury and CSF blood contamination. An improved technique was thus developed and characterized.

METHOD

Magnetic resonance imaging was used to identify the space and position of the cisterna magna in monkeys. Accordingly, a newly defined procedure for needle punctuation was tested in comparison with the traditional method. Blood contamination in CSF samples and brainstem injury were determined to define the superior of the improved method over the transitional method.

RESULTS

The cisterna magna in monkeys was found to be a "▽" shape. The needle was punctured into the cisterna magna aiming at the wider superior gap avoided brainstem injury. The improved method showed that the rate of blood contamination in the CSF samples was reduced from 66.7% to 16.7%, the higher rate of blood contamination was associated with higher risk for brainstem injury.

COMPARISON WITH EXISTING METHODS

In traditional method, the needle is punctured aiming at the inferior gap with high density of blood vessels. In improved method, the needle is punctured aiming at the superior gap, pointing to the nose root while advancing the needle and avoiding injury to blood vessels.

CONCLUSIONS

This improved technique not only avoids blood contamination of CSF, but also prevents brainstem injury during the process of CSF collection. It is recommended for adaptation for CSF collection in monkeys.

Inhibitor of signal transducer and activator of transcription 3 (STAT3) suppresses ovarian cancer growth, migration and invasion and enhances the effect of cisplatin in vitro

The aim of the present study was to investigate the anti-ovarian cancer effect of the inhibitor of signal transducer and activator of transcription 3 (STAT3), WP1066. Western blot was used to detect the phosphorylation of STAT3 in ovarian cancer cell line SKOV3 and cisplatin-resistant ovarian cancer cell line SKOV3/DDP. MTT and colony-forming assays were performed to evaluate the viability and growth of ovarian cancer cells. The apoptosis of ovarian cancer cells was determined by flow cytometry. The wound healing assay and Transwell assay were performed to examine the migration and invasion of ovarian cancer cells. WP1066 significantly inhibited the phosphorylation of STAT3 in SKOV3 and SKOV3/DDP cells. WP1066 treatment inhibited the proliferation and clonogenicity of both SKOV3 and SKOV3/DDP cells. After WP1066 treatment for 24 h, the apoptosis rates of SKOV3 and SKOV3/DDP cells were significantly increased compared with the control cells. After treatment with WP1066, the reduction of the wound gaps was significantly less in both SKOV3 and SKOV3/DDP cells. WP1066 also significantly inhibited the invasion capacity of SKOV3 and SKOV3/DDP cells compared with the control group. Treatment with WP1066 combined with cisplatin significantly increased proliferation inhibition and apoptosis in SKOV3 and SKOV3/ DDP cells compared with treatment with cisplatin alone. A synergistic action between WP1066 and cisplatin on the proliferation and apoptosis of ovarian cancer cells was determined. In conclusion, inhibition of STAT3 may suppress the proliferation, migration and invasion, induce apoptosis and enhance the chemosensitivity of ovarian cancer cells, indicating that STAT3 is a new therapeutic target of ovarian cancer.

Canagliflozin in Asian patients with type 2 diabetes on metformin alone or metformin in combination with sulphonylurea

AIMS

To evaluate the efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in Asian patients with type 2 diabetes mellitus (T2DM) inadequately controlled by metformin or metformin in combination with sulphonylurea.

METHODS

In this 18-week, randomized, double-blind, placebo-controlled phase III study, patients (N = 676) received canagliflozin 100 or 300 mg or placebo once daily. The primary efficacy endpoint was change in glycated haemoglobin (HbA1c) level from baseline at week 18. Additional endpoints included change in fasting plasma glucose (FPG) and percent change in body weight. Adverse events (AEs) were recorded throughout the study. Efficacy and safety were assessed in the overall population and in two strata based on background therapy.

RESULTS

At week 18, canagliflozin 100 and 300 mg provided significant reductions from baseline in HbA1c compared with placebo (-0.97, -1.06 and -0.47%, respectively; p < 0.001). Relative to placebo, canagliflozin 100 and 300 mg also significantly reduced FPG (-1.0 and -1.4 mmol/l) and body weight [-2.2% (-1.5 kg) and -2.3% (-1.6 kg)]. Both canagliflozin doses lowered systolic blood pressure (BP) compared with placebo. The overall incidence of AEs was 38.6, 43.2 and 42.0% with canagliflozin 100 and 300 mg and placebo, respectively. The incidence of genital mycotic infections and urinary tract infections was low and similar across groups. Efficacy and safety findings in the two strata were generally consistent with the overall population.

CONCLUSIONS

Canagliflozin provided glycaemic improvements and reductions in body weight and systolic BP, and was generally well tolerated in Asian patients with T2DM on metformin or metformin in combination with sulphonylurea.

Sensitization of suberoylanilide hydroxamic acid (SAHA) on chemoradiation for human cervical cancer cells and its mechanism

PURPOSE

To explore the sensitization of suberoylanilide hydroxamic acid (SAHA) on chemoradiation for cervical cancer cells and its mechanism.

MATERIALS AND METHODS

After human cervical cancer SiHa cells were treated with SAHA and cisplatin (DDP) of different concentrations, inhibition and apoptosis rates, and cell cycle were detected. SiHa cells underwent radiation of various doses after treated with 20% IC50 of SAHA for 24 hours. The survival fraction of SiHa cells was calculated by colony-forming assay, and related parameters were calculated. mRNA and protein expressions of P21, Bax and Ku70 were detected.

RESULTS

The inhibition rate was higher in SD (SAHA combined with DDP) group than in D (DDP alone) group (p < 0.05). The number of cells in G0/G1 phase was higher, and the number of cells in G2/M+S phase and PI (proliferation index) were lower in S (SAHA), D, and SD groups than in control group, and in SD group than in S and D groups (p < 0.05). The apoptosis rate and the expressions of mRNA and protein of Bax and P21 were higher in SD group than in S or D group (p < 0.05). The cell survival fraction was lower in SAHA combined with radiotherapy group than in radiotherapy alone group (p < 0.05). Do, N, and Dq values were 2.329, 2.761, and 1.721, respectively, in radiotherapy alone group and 1.213, 4.770, and 0.823, respectively, in SAHA combined with radiotherapy group. SER was 1.92. Bax mRNA and protein expressions were higher but Ku70 mRNA and protein expressions were lower in SAHA combined with radiotherapy group than in radiotherapy alone group (p < 0.05).

CONCLUSION

SAHA promotes SiHa apoptosis in chemotherapy through up-regulation of mRNA and protein of p21 and Bax which leads to cell cycle arrest in G0/G1 phase. Low dose of SAHA promotes SiHa apoptosis and inhibits cell repair in radiotherapy through Bax up-regulation and Ku70 down-regulation.

Role of copper in regression of cardiac hypertrophy

Pressure overload causes an accumulation of homocysteine in the heart, which is accompanied by copper depletion through the formation of copper-homocysteine complexes and the excretion of the complexes. Copper supplementation recovers cytochrome c oxidase (CCO) activity and promotes myocardial angiogenesis, along with the regression of cardiac hypertrophy and the recovery of cardiac contractile function. Increased copper availability is responsible for the recovery of CCO activity. Copper promoted expression of angiogenesis factors including vascular endothelial growth factor (VEGF) in endothelial cells is responsible for angiogenesis. VEGF receptor-2 (VEGFR-2) is critical for hypertrophic growth of cardiomyocytes and VEGFR-1 is essential for the regression of cardiomyocyte hypertrophy. Copper, through promoting VEGF production and suppressing VEGFR-2, switches the VEGF signaling pathway from VEGFR-2-dependent to VEGFR-1-dependent, leading to the regression of cardiomyocyte hypertrophy. Copper is also required for hypoxia-inducible factor-1 (HIF-1) transcriptional activity, acting on the interaction between HIF-1 and the hypoxia responsible element and the formation of HIF-1 transcriptional complex by inhibiting the factor inhibiting HIF-1. Therefore, therapeutic targets for copper supplementation-induced regression of cardiac hypertrophy include: (1) the recovery of copper availability for CCO and other critical cellular events; (2) the activation of HIF-1 transcriptional complex leading to the promotion of angiogenesis in the endothelial cells by VEGF and other factors; (3) the activation of VEGFR-1-dependent regression signaling pathway in the cardiomyocytes; and (4) the inhibition of VEGFR-2 through post-translational regulation in the hypertrophic cardiomyocytes. Future studies should focus on target-specific delivery of copper for the development of clinical application.

A novel knot method for individually measurable aortic constriction in rats

A novel knot method in rats is reported that addresses several drawbacks in the current model of aortic constriction-induced heart hypertrophy. Using a rat model, we developed a two-step procedure that includes 1) measurement of individual aorta circumference using a surgical thread; and 2) constriction of the aorta using a thread with the desired length predefined by a knot at each end for a measurable reduction of the aortic circumference as referenced to the measurement in step 1. This knot approach produces a manageable gradient of aortic constriction in each rat, reaching a consistency among experimental animals that cannot be achieved by the traditional needle method. Notably, the animal model produced by our knot method showed cardiac hypertrophy and dysfunction with the severity proportional to the percentage reduction of the aorta circumference (50% vs. 60%). Additionally, our new procedure produced a lower mortality rate compared with the traditional needle method. Therefore, we recommend this knot method as an alternative procedure for aortic constriction with desired gradient in rats and larger-animal models.

Comparative proteomic analysis of Bombyx mori hemocytes treated with destruxin A

Destruxin A (DA), a cyclodepsipeptidic secondary metabolite of the entomopathogenic fungus, Metarhizium anisopliae, is an important anti-immunity agent against insect hemocytes. To understand the mechanism of the molecular responses to DA, fifth-instar larvae of the silkworm, Bombyx mori, were injected with 2 μg of DA. The proteomics of hemocytes were then investigated using two-dimensional electrophoresis and mass spectrometry, and validated qPCR. As a result, a total of 47 differently expressed protein spots were detected and 22 proteins in 26 spots were identified. There are eight immunity-related proteins, including three downregulated proteins (antitrypsin isoform 3, p50 protein, and calreticulin precursor) and five upregulated proteins (C-type lectin 10 precursor, serine proteinase-like protein, paralytic peptide, PPO-1, and PPO-2). Four resistance- and/or stress-related proteins (arginine kinase, carboxylesterase clade H, member 1, aminoacylase, and thiol peroxiredoxin) were upregulated. Ten proteins with other or unknown functions were also recorded. Five selected proteins were verified with qPCR. These results provide new insights into the molecular mechanism of host immune response to DA challenge.

U4 at the 3' UTR of PB1 segment of H5N1 influenza virus promotes RNA polymerase activity and contributes to viral pathogenicity

The viral RNA-dependent RNA polymerase has been found to contribute to efficient replication in mammalian systems and to the high pathogenicity of H5N1 influenza A virus in humans and other mammals. The terminal untranslated regions of the viral segments perform functions such as polyadenylation and contain signals for genomic packaging and initiation of RNA synthesis. These sequences are highly conserved, apart from a U/C polymorphism at position 4 of the 3′ end, most often seen in the polymerase gene segments. However, no study has yet tested whether the untranslated regions of H5N1 make any contribution to its high pathogenicity. Herein, the association of the fourth nucleotide at the 3′ end of the untranslated region in segment 2 (PB1), of A/Vietnam/1194/2004 (H5N1), with pathogenicity was examined in mice. To this end, an RNA polymerase reporter system was constructed, and viruses with mutations at this site were rescued. Results showed the U₄ in PB1 was found to contribute to greater amounts of RNA-dependent RNA polymerase activity and differentially regulate genomic transcription and replication. Although a recombinant H5N1 virus with the rarer C₄ sequence in all eight segments was viable and replicated to high titers in vitro, replacing a single U₄ at the 3′ termini of the PB1 gene segment enhanced viral reproduction and more pathogenesis. In this way, these data showed the importance of untranslated regions of H5N1 influenza virus to pathogenicity.

Isolation and characterization of endothelial progenitor cells from Rhesus monkeys

Background

Endothelial progenitor cells (EPCs) are increasingly becoming a major focus of regenerative medicine research and practice. The present study was undertaken to establish an appropriate procedure for isolation and characterization of EPCs from Rhesus monkeys for regenerative medicine research.

Result

Selective CD34+ and nonselective mononuclear EPCs were isolated from bone marrow and cultured under varying conditions. The results showed that nonselective mononuclear EPCs were a better choice for high yield of the target cells. The cells grew in M 200 better than in EGM-2, and supplementation with fetal bovine serum promoted cell proliferation; but serum level at 7.5% was better than at 10%. In addition, surface coating of the culture dishes with human fibronectin significantly improved the proliferation and ontogeny of the isolated EPCs. Immunocytochemistry including detection of markers CD34, CD133 and CD31 and double-staining for Ac-LDL and lectin verified the purity of the cultured mononuclear EPCs.

Conclusion

By a thorough analysis, we established a practical procedure for isolation and propagation of EPCs from Rhesus monkeys. This procedure would help using these valuable cells for regenerative medicine research.

Detection of hepatic hemodynamics in normal rhesus monkeys using high-frequency ultrasound

The rhesus monkey liver disease model provides useful information for hepatic research, as studies of hepatic hemodynamics in humans are rare. A 3-9 MHz high-frequency linear transducer (iU22, Philips Medical Systems, Royal Philips Electronics, The Netherlands) was used to obtain ultrasonograms of the livers of 28 normal rhesus monkeys (16 males, 12 females). Diameters of the portal vein and proper hepatic artery; maximum velocity of the portal vein; and peak-systolic and end-diastolic velocity and resistive index of the proper hepatic artery were also assessed. The portal vein and proper hepatic artery were 0.584 ± 0.123 and 0.151 ± 0.052 cm in diameter, respectively. The maximum velocity of the portal vein was 40.2 ± 13.7 cm/s. Peak systolic velocity and resistive index of the proper hepatic artery were 72.2 ± 25.4 cm/s and 0.67 ± 0.10, respectively. We found that high-frequency Doppler ultrasonography can be used to obtain clear portal vein and proper hepatic artery ultrasonograms and to measure the hemodynamic parameters of the portal vein and proper hepatic artery in rhesus monkeys. It is thus an effective method for studying changes in hepatic hemodynamics and has interesting technical and therapeutic implications. Our results provide useful information and establish normal reference values for future studies of adult healthy rhesus monkeys.

Exposure to perfluorooctane sulfonate in utero reduces testosterone production in rat fetal Leydig cells

BACKGROUND

Perfluorooctane sulfonate (PFOS) is a synthetic material that has been widely used in industrial applications for decades. Exposure to PFOS has been associated with decreased adult testosterone level, and Leydig cell impairment during the time of adulthood. However, little is known about PFOS effects in utero on fetal Leydig cells (FLC).

METHODS AND RESULTS

The present study investigated effects of PFOS on FLC function. Pregnant Sprague Dawley female rats received vehicle (0.05% Tween20) or PFOS (5, 20 mg/kg) by oral gavage from gestational day (GD) 11-19. At GD20, testosterone (T) production, FLC numbers and ultrastructure, testicular gene and protein expression levels were examined. The results indicate that exposures to PFOS have affected FLC function as evidenced by decreased T production, impaired FLC, reduced FLC number, and decreased steroidogenic capacity and cholesterol level in utero.

CONCLUSION

The present study shows that PFOS is an endocrine disruptor of male reproductive system as it causes reduction of T production and impairment of rat fetal Leydig cells.

Exposure to perfluorooctane sulfonate in utero reduces testosterone production in rat fetal Leydig cells

BACKGROUND

Perfluorooctane sulfonate (PFOS) is a synthetic material that has been widely used in industrial applications for decades. Exposure to PFOS has been associated with decreased adult testosterone level, and Leydig cell impairment during the time of adulthood. However, little is known about PFOS effects in utero on fetal Leydig cells (FLC).

METHODS AND RESULTS

The present study investigated effects of PFOS on FLC function. Pregnant Sprague Dawley female rats received vehicle (0.05% Tween20) or PFOS (5, 20 mg/kg) by oral gavage from gestational day (GD) 11-19. At GD20, testosterone (T) production, FLC numbers and ultrastructure, testicular gene and protein expression levels were examined. The results indicate that exposures to PFOS have affected FLC function as evidenced by decreased T production, impaired FLC, reduced FLC number, and decreased steroidogenic capacity and cholesterol level in utero.

CONCLUSION

The present study shows that PFOS is an endocrine disruptor of male reproductive system as it causes reduction of T production and impairment of rat fetal Leydig cells.

Decreases in electrocardiographic R-wave amplitude and QT interval predict myocardial ischemic infarction in Rhesus monkeys with left anterior descending artery ligation

Clinical studies have demonstrated the predictive values of changes in electrocardiographic (ECG) parameters for the preexisting myocardial ischemic infarction. However, a simple and early predictor for the subsequent development of myocardial infarction during the ischemic phase is of significant value for the identification of ischemic patients at high risk. The present study was undertaken by using non-human primate model of myocardial ischemic infarction to fulfill this gap. Twenty male Rhesus monkeys at age of 2–3 years old were subjected to left anterior descending artery ligation. This ligation was performed at varying position along the artery so that it produced varying sizes of myocardial infarction at the late stage. The ECG recording was undertaken before the surgical procedure, at 2 h after the ligation, and 8 weeks after the surgery for each animal. The correlation of the changes in the ECG waves in the early or the late stage with the myocardial infarction size was analyzed. The R wave depression and the QT shortening in the early ischemic stage were found to have an inverse correlation with the myocardial infarction size. At the late stage, the R wave depression, the QT prolongation, the QRS score, and the ST segment elevation were all closely correlated with the developed infarction size. The poor R wave progression was identified at both the early ischemic and the late infarction stages. Therefore, the present study using non-human primate model of myocardial ischemic infarction identified the decreases in the R wave and the QT interval as early predictors of myocardial infarction. Validation of these parameters in clinical studies would greatly help identifying patients with myocardial ischemia at high risk for the subsequent development of myocardial infarction.

Proteomic and properties analysis of botanical insecticide rhodojaponin III-induced response of the diamondback moth, Plutella xyllostella (L.)

BACKGROUND

Rhodojaponin III, as a botanical insecticide, affects a wide variety of biological processes in insects, including reduction of feeding, suspension of development, and oviposition deterring of adults in a dose-dependent manner. However, the mode of these actions remains obscure.

PRINCIPAL FINDINGS

In this study, a comparative proteomic approach was adopted to examine the effect of rhodojaponin III on the Plutella xyllostella (L.). Following treating 48 hours, newly emergence moths were collected and protein samples were prepared. The proteins were separated by 2-DE, and total 31 proteins were significantly affected by rhodojaponin III compared to the control identified by MALDI-TOF/TOF-MS/MS. These differentially expressed proteins act in the nervous transduction, odorant degradation and metabolic change pathways. Further, gene expression patterns in treated and untreated moths were confirmed by qRT-PCR and western blot analysis. RNAi of the chemosensory protein (PxCSP) gene resulted in oviposition significantly increased on cabbage plants treated with rhodojaponin III.

CONCLUSIONS

These rhodojaponin III-induced proteins and gene properties analysis would be essential for a better understanding of the potential molecular mechanism of the response to rhodojaponin III from moths of P. xylostella.