Picosecond Spin Current Generation from Vicinal Metal-Antiferromagnetic Insulator Interfaces

We report the picosecond spin current generation from the interface between a heavy metal and a vicinal antiferromagnet insulator Cr_{2}O_{3} by laser pulses at room temperature and zero magnetic field. It is converted into a detectable terahertz emission in the heavy metal via the inverse spin Hall effect. The vicinal interfaces are apparently the source of the picosecond spin current, as evidenced by the proportional terahertz signals to the vicinal angle. We attribute the origin of the spin current to the transient magnetic moment generated by an interfacial nonlinear magnetic-dipole difference-frequency generation. We propose a model based on the in-plane inversion symmetry breaking to quantitatively explain the terahertz intensity with respect to the angles of the laser polarization and the film azimuth. Our work opens new opportunities in antiferromagnetic and ultrafast spintronics by considering symmetry breaking.

Integrin αvβ1 facilitates ACE2-mediated entry of SARS-CoV-2

Integrins have been suggested to be involved in SARS-CoV-2 infection, but the underlying mechanisms remain largely unclear. This study aimed to investigate how integrins facilitate the ACE2-mediated cellular entry of SARS-CoV-2. We first tested the susceptibility of a panel of human cell lines to SARS-CoV-2 infection using the spike protein pseudotyped virus assay and examined the expression levels of integrins in these cell lines by qPCR, western blot and flow cytometry. We found that integrin αvβ1 was highly enriched in the SARS-CoV-2 susceptible cell lines. Additional studies demonstrated that RGD (403-405)→AAA mutant was defective in binding to integrin αvβ1 compared to its wild type counterpart, and anti-αvβ1 integrin antibodies significantly inhibited the entry of SARS-CoV-2 into the cells. Further studies using mouse NIH3T3 cells expressing human ACE2, integrin αv, integrin β1, and/or integrin αvβ1 suggest that integrin αvβ1 was unable to function as an independent receptor but could significantly facilitate the cellular entry of SASR-CoV-2. Finally, we observed that the Omicron exhibited a significant increase in the ACE2-mediated viral entry. Our findings may enhance our understanding of the pathogenesis of SARS-CoV-2 infection and offer potential therapeutic target for COVID-19.

IL-13 induced inflammation increases DPP4 abundance but does not enhance MERS-CoV replication in airway epithelia

BACKGROUND

Chronic pulmonary conditions such as asthma and COPD increase the risk of morbidity and mortality during infection with the Middle East respiratory syndrome coronavirus (MERS-CoV). We hypothesized that individuals with such comorbidities are more susceptible to MERS-CoV infection due to increased expression of its receptor, dipeptidyl peptidase 4 (DPP4).

METHODS

We modeled chronic airway disease by treating primary human airway epithelia with the Th2 cytokine IL-13, examining how this impacted DPP4 protein levels along with MERS-CoV entry and replication.

RESULTS

IL-13 exposure for 3 days led to increased DPP4 protein abundance, while a 21-day treatment increased DPP4 levels and caused goblet cell metaplasia. Surprisingly, despite this increase in receptor availability, MERS-CoV entry and replication were not significantly impacted by IL-13 treatment.

CONCLUSIONS

Our results suggest that increased DPP4 abundance is likely not the primary mechanism leading to increased MERS severity in the setting of Th2 inflammation. Transcriptional profiling analysis highlighted the complexity of IL-13 induced changes in airway epithelia, including altered expression of genes involved in innate immunity, antiviral responses, and maintenance of the extracellular mucus barrier. These data suggest that additional factors likely interact with DPP4 abundance to determine MERS-CoV infection outcomes.

Nsp3-N interactions are critical for SARS-CoV-2 fitness and virulence

SARS-CoV-2, the causative agent of COVID-19 encodes at least 16 nonstructural proteins of variably understood function. Nsp3, the largest nonstructural protein contains several domains, including a SARS-unique domain (SUD), which occurs only in Sarbecovirus. The SUD has a role in preferentially enhancing viral translation. During isolation of mouse-adapted SARS-CoV-2, we isolated an attenuated virus that contained a single mutation in a linker region of nsp3 (nsp3-S676T). The S676T mutation decreased virus replication in cultured cells and primary human cells and in mice. Nsp3-S676T alleviated the SUD translational enhancing ability by decreasing the interaction between two translation factors, Paip1 and PABP1. We also identified a compensatory mutation in the nucleocapsid (N) protein (N-S194L) that restored the virulent phenotype, without directly binding to SUD. Together, these results reveal an aspect of nsp3-N interactions, which impact both SARS-CoV-2 replication and, consequently, pathogenesis.

The influence of parents' perception on online education and training brand recognition

At present, the academic education of Chinese students is basically public education, but the quality training is mainly handed over to the market for training. Therefore, China's online education and training institutions have gradually developed under this demand. With the improvement of people's living standards, families have higher and higher requirements for children's education, expecting that children can be well improved in physical, mental and psychological aspects, and hoping that they will have their own advantages in the future competition. Therefore, this paper studies the influence of parents' perception on the brand recognition of online education and training. Through the analysis of dance online training institutions, the research shows that among the three categories, teachers' Graduation schools account for the highest proportion, with an average proportion of 47.07%, followed by teachers' grade certificates, with a proportion of 32.29%, and teachers' competition scores of 25.57%. Therefore, in the process of operation, online dance training institutions should meet the needs of parents to understand the professional level of teachers. Improve the service system of training institutions, improve the parent brand recognition and the number of customers of training institutions, further improve online education and training institutions, and provide them with improvement suggestions and measures for reference.

Research on the Filtering and Classification Method of Interactive Music Education Resources Based on Neural Network

This work intends to classify and integrate music genres and emotions to improve the quality of music education. This work proposes a web image education resource retrieval method based on semantic network and interactive image filtering for a music education environment. It makes a judgment on these music source data and then uses these extracted feature sequences as the emotions expressed in the model of the combination of Long Short-Term Memory (LSTM) and Attention Mechanism (AM), thus judging the emotion category of music. The emotion recognition accuracy has increased after improving LSTM-AM into the BiGR-AM model. The greater the difference between emotion genres is, the easier it is to analyze the feature sequence containing emotion features, and the higher the recognition accuracy is. The classification accuracy of the excited, relieved, relaxed, and sad emotions can reach 76.5%, 71.3%, 80.8%, and 73.4%, respectively. The proposed interactive filtering method based on a Convolutional Recurrent Neural Network can effectively classify and integrate music resources to improve the quality of music education.

Effects of piano music of different tempos on heart rate and autonomic nervous system during the recovery period after high-intensity exercise

Purpose

The present study attempted to explore the effects of different tempos of piano music on heart rate and autonomous nervous system during the recovery period after high‐intensity exercise. In addition, the study analyzed the influence of different tempos on the recovery period of athletes to devise methods for accelerating fatigue recovery through piano music.

Method

A total of 57 college students majoring in physical education were selected as experimental subjects and were divided into three groups, namely Lento group (n = 20), Moderato group (n = 20), and Allegretto group (n = 20; only 17 students completed the experiment).

Results

Under the same high‐intensity exercise regimen, the three groups did not differ significantly in the body composition, high‐intensity exercise ability, and time‐domain variation indices, namely heart rate (HR), heart rate variability index parameters (p > .05). The time‐domain variation analysis in the recovery period revealed significant differences in HR frequency domain indices among the groups exposed to different rhythms (p < .05).

Conclusion

Moderate‐tempo piano music was the most effective in facilitating HR and autonomic nervous system recovery during the recovery period.

Downregulation of Diacylglycerol kinase zeta (DGKZ) suppresses tumorigenesis and progression of cervical cancer by facilitating cell apoptosis and cell cycle arrest

Diacylglycerol kinase zeta (DGKZ) participates in cancer progression. Here, the current work aims to identify the functional role of DGKZ in cervical cancer (CC). DGKZ expression in cervical cancer tissues and paired adjacent normal cervical tissues was assessed using Immunohistochemistry assay. SiHa and HeLa cells were transfected with lentivirus plasmids (sh-DGKZ or sh-NC) to evaluate the effects of DGKZ knockdown on cell proliferation, apoptosis and cell cycle distribution in vitro. Furthermore, BALB/c nude mice were injected subcutaneously with Lentivirus-sh-DGKZ-SiHa cells or Lentivirus-sh-NC-SiHa cells to analyze the influence of DGKZ silencing on tumor growth of CC in vivo. Moreover, the potential molecular mechanisms were predicted by GO and KEGG analysis and preliminarily explored through PathScan Analysis. Elevated DGKZ expression in cervical tumor was observed. Downregulation of DGKZ repressed proliferation and boosted apoptosis of SiHa and HeLa cells and induced cell cycle arrest at G0/G1 phase. In addition, Knockdown of DGKZ restrained tumor growth in tumor xenograft mice. Importantly, GO and KEGG analysis displayed that differentially expressed proteins induced by silence of DGKZ were mostly enriched in autophagy or mitophagy, indicating that the functions of DGKZ on cell proliferation and tumor growth may be associated with autophagy or mitophagy. PathScan analysis presented that PI3K-AKT and TAK1-NF-κB signaling pathways were prominently inhibited in SiHa cells transfected with sh-DGKZ. In summary, downregulation of DGKZ impeded cell proliferation, boosted cell apoptosis and induced cell cycle arrest to suppress tumorigenesis and progression of cervical cancer.

The role of loneliness in the development of depressive symptoms among partnered dementia caregivers: Evidence from the English Longitudinal Study of Aging

Background

Depressive symptoms are highly prevalent among partnered dementia caregivers, but the mechanisms are unclear. This study examined the mediating role of loneliness in the association between dementia and other types of care on subsequent depressive symptoms.

Methods

Prospective data from partnered caregivers were drawn from the English Longitudinal Study of Aging. The sample consisted of 4,672 partnered adults aged 50–70 living in England and Wales, followed up between 2006–2007 and 2014–2015. Caregiving was assessed across waves 3 (2006–2007), 4 (2008–2009), and 5 (2010–2011), loneliness at wave 6 (2012–2013), and subsequent depressive symptoms at wave 7 (2014–15). Multivariable logistic regression models were used to assess the association between caregiving for dementia and depressive symptoms compared to caregiving for other illnesses (e.g., diabetes, coronary heart disease (CHD), cancer, and stroke). Binary mediation analysis was used to estimate the indirect effects of caregiving on depressive symptoms via loneliness.

Results

Care for a partner with dementia was associated with higher odds of depressive symptoms at follow-up compared to those not caring for a partner at all (odds ratio [OR] = 2.6, 95% confidence intervals [CI]: 1.4, 5.1). This association was partially mediated by loneliness (34%). Care for a partner with other conditions was also associated with higher odds of depressive symptoms compared to non-caregiving partners (OR = 1.7, 95% CI: 1.2, 2.5), but there was no evidence of an indirect pathway via loneliness.

Conclusion

Loneliness represents an important contributor to the relationship between dementia caregiving and subsequent depressive symptoms; therefore, interventions to reduce loneliness among partnered dementia caregivers should be considered.

Metabolism response of grazing yak to dietary concentrate supplementation in warm season

Supplementary feeding has a significant effect on the growth performance of grazing yaks. However, as far as is known, little information is available concerning how energy or protein feed supplementation affects the serum metabolome of grazing yaks during the warm season. We investigated the effects of supplementation with two different concentrates on the serum metabolome in grazing yaks using nuclear magnetic resonance spectroscopy in conjunction with multivariate data analysis. Twenty-four 2-year-old female yaks (133.04 ± 6.52 kg BW) were randomly divided into three groups and fed three different regimes (n = 8 per group): (1) grazing plus hull-less barley (HLB) supplementation, (2) grazing plus rapeseed meal (RSM) supplementation, and (3) grazing without supplementation. Both HLB and RSM supplementation significantly increased the average daily gain (ADG), and ADG under HLB supplementation was 11.9% higher (P < 0.05) than that of the RSM group. Supplementation markedly altered glucose, lipid, and protein metabolism, with the difference manifested as increased levels of some amino acids, acetyl-glycoproteins, low-density lipoproteins, and very low-density lipoproteins . Furthermore, the levels of 3-hydroxybutyrate, acetoacetate, and lactate metabolism were decreased. Serum metabolite changes in yaks in the HLB supplementation treatment differed from those in the RSM supplementation treatment; the difference was primarily manifested in lipid- and protein-related metabolites. We conclude that both the energy supplementation (HLB) and the protein supplementation (RSM) could remarkably promote the growth of yak heifers during the warm season, and the effect of energy supplementation was superior. Supplementary feeding changed the serum metabolite levels of yak heifers, indicating that such feeding could improve glucose's energy-supply efficiency and increase the metabolic intensity of lipids and proteins. Supplementation of yaks with HLB was more efficient in the promotion of yak glucose and protein anabolism compared to supplementation with RSM, while having a lesser effect on lipid metabolism.

F-box protein FBXO31 modulates apoptosis and epithelial-mesenchymal transition of cervical cancer via inactivation of the PI3K/AKT-mediated MDM2/p53 axis

AIMS

Cervical cancer (CC) is one of the most common malignant tumours in the world and a serious threat to women's health. The dysregulation of protein degradation mediated by F-box proteins is involved in tumorigenesis, and F-box protein FBXO31 has been reported to play an important role in various human cancers. However, the role of FBXO31 in CC remains unclear. This study aimed to investigate the function and underlying regulatory mechanism of FBXO31 in CC.

MAIN METHODS

In this study, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were used to measure target gene expression; the Cell Counting Kit-8, cell death ELISA, Transwell invasion assay, wound-healing assay and western blot were applied to assess cell viability, apoptosis, invasion, migration and epithelial-mesenchymal transition (EMT), respectively.

KEY FINDINGS

FBXO31 was expressed at a low level in 37 pairs of CC tissues and three types of CC cell lines. Overexpression of FBXO31 inhibited cell viability, invasion, migration, EMT and induced apoptosis in SiHa cells. FBXO31 promoted p53 activity through suppression of murine double minute 2 (MDM2) expression. Overexpression of MDM2 ameliorated the inhibitory effect of FBXO31 on SiHa cells, while the MDM2/p53 axis-specific inhibitor Nutlin-3a facilitated this inhibitory effect. Further, we confirmed that FBXO31 inactivated MDM2/p53 axis dependence on the phospholipid inositol 3-kinase (PI3K)/protein kinase B (AKT) signalling pathway.

SIGNIFICANCE

Collectively, our results reveal that FBXO31 down-regulates CC progression by blocking the PI3K/AKT-mediated MDM2/p53 axis, suggesting that FBXO31 may serve as a promising therapeutic target for CC treatment.

Accelerated diversification correlated with functional traits shapes extant diversity of the early divergent angiosperm family Annonaceae

A major goal of phylogenetic systematics is to understand both the patterns of diversification and the processes by which these patterns are formed. Few studies have focused on the ancient, species-rich Magnoliales clade and its diversification pattern. Within Magnoliales, the pantropically distributed Annonaceae are by far the most genus-rich and species-rich family-level clade, with c. 110 genera and c. 2,400 species. We investigated the diversification patterns across Annonaceae and identified traits that show varied associations with diversification rates using a time-calibrated phylogeny of 835 species (34.6% sampling) and 11,211 aligned bases from eight regions of the plastid genome (rbcL, matK, ndhF, psbA-trnH, trnL-F, atpB-rbcL, trnS-G, and ycf1). Twelve rate shifts were identified using BAMM: in Annona, Artabotrys, Asimina, Drepananthus, Duguetia, Goniothalamus, Guatteria, Uvaria, Xylopia, the tribes Miliuseae and Malmeeae, and the Desmos-Dasymaschalon-Friesodielsia-Monanthotaxis clade. TurboMEDUSA and method-of-moments estimator analyses showed largely congruent results. A positive relationship between species richness and diversification rate is revealed using PGLS. Our results show that the high species richness in Annonaceae is likely the result of recent increased diversification rather than the steady accumulation of species via the 'museum model'. We further explore the possible role of selected traits (habit, pollinator trapping, floral sex expression, pollen dispersal unit, anther septation, and seed dispersal unit) in shaping diversification patterns, based on inferences of BiSSE, MuSSE, HiSSE, and FiSSE analyses. Our results suggest that the liana habit, the presence of circadian pollinator trapping, androdioecy, and the dispersal of seeds as single-seeded monocarp fragments are closely correlated with higher diversification rates; pollen aggregation and anther septation, in contrast, are associated with lower diversification rates.

MYH9 Aggregation Induced by Direct Interaction With PRRSV GP5 Ectodomain Facilitates Viral Internalization by Permissive Cells

Prevention and control of infection by porcine reproductive and respiratory syndrome virus (PRRSV) remains a challenge, due to our limited understanding of the PRRSV invasion mechanism. Our previous study has shown that PRRSV glycoprotein GP5 interacts with MYH9 C-terminal domain protein (PRA). Here we defined that the first ectodomain of GP5 (GP5-ecto-1) directly interacted with PRA and this interaction triggered PRA and endogenous MYH9 to form filament assembly. More importantly, MYH9 filament assembly was also formed in GP5-ecto-1-transfected MARC-145 cells. Notably, PRRSV infection of MARC-145 cells and porcine alveolar macrophages also induced endogenous MYH9 aggregation and polymerization that were required for subsequent PRRSV internalization. Moreover, overexpression of S100A4, a MYH9-specific disassembly inducer, in MARC-145 cells significantly resulted in diminished MYH9 aggregation and marked inhibition of subsequent virion internalization and infection by both PRRSV-1 and PRRSV-2 isolates. The collective results of this work reveal a novel molecular mechanism employed by MYH9 that helps PRRSV gain entry into permissive cells.

Direct Interaction Between CD163 N-Terminal Domain and MYH9 C-Terminal Domain Contributes to Porcine Reproductive and Respiratory Syndrome Virus Internalization by Permissive Cells

Porcine reproductive and respiratory syndrome virus (PRRSV) has a highly restricted tropism for cells of the monocyte-macrophage lineage, including porcine alveolar macrophages (PAMs). PRRSV entry into permissive cells involves several mediators in addition to two required host cell receptors, CD163 and MYH9. It is unknown whether CD163 directly interacts and/or cooperates with MYH9 to facilitate PRRSV infection. In this study, CD163 and MYH9 were co-immunoprecipitated from PAMs regardless of PRRSV infection status. Further truncation analysis indicated that the CD163 N-terminal region, containing scavenger receptor cysteine-rich domains 1 to 4 (SRCR1-4), directly interacts with the MYH9 C-terminal domain region without involvement of other adaptor proteins. Meanwhile, non-permissive HEK293T cells that stably expressed truncated swine CD163 SRCR1-4 domain did not support virus attachment. However, virus attachment to cells stably expressing SRCR5-CT domain was demonstrated to occur without appreciable virus internalization. The involvement of the SRCR1-4 domain in virus internalization was further demonstrated by the fact that incubation of recombinant SRCR1-4 protein with PAMs abolished subsequent virus internalization by permissive cells. These results demonstrated that CD163 SRCR1-4 interacts with the MYH9 C–terminal domain to facilitate PRRSV virion internalization in permissive cells, thus expanding our understanding of PRRSV cell-invasion mechanisms.

Hyperspectral Multiplexed Biological Imaging of Nanoprobes Emitting in the Short-Wave Infrared Region

Optical bioimaging with exogenous luminophores emitting in short-wave infrared spectral region (SWIR, ~ 1000-1700 nm) is a rapidly developing field, and the development of multiple SWIR-photoluminescent nanoprobes has recently been reported. In this regard, hyperspectral imaging (HSI), combined with unmixing algorithms, is a promising tool that can allow for efficient multiplexing of the SWIR-emitting nanoagents by their photoluminescence (PL) spectral profiles. The SWIR HSI technique reported here is developed to multiplex two types of nanoprobes: polymeric nanoparticles doped with organic dye (PNPs) and rare-earth doped fluoride nanoparticles (RENPs). Both types of nanoprobes exhibit PL in the same spectral range (~ 900-1200 nm), which hinders spectral separation of PL with optical filters and limits possibilities for their multiplexed imaging in biological tissues. By applying SWIR HSI, we exploited differences in the PL spectral profiles and achieved the spectrally selective and sensitive imaging of the PL signal from every type of nanoparticles. Unmixing of acquired data allowed for multiplexing of the spectrally overlapping nanoprobes by their PL profile. Both quantitative and spatial distribution for every type of nanoparticles were obtained from their mixed suspensions. Finally, the SWIR HSI technique with unmixing protocol was applied to in vivo imaging of mice subcutaneously injected with PNPs and RENPs. The applicability of hyperspectral techniques to multiplex nanoprobes in the in vivo imaging was successfully demonstrated.

NP30 stimulates Th17 differentiation through DC in Schistosomiasis Japonicum

The murine monoclonal anti‐idiotypic antibody, NP30, is a potential vaccine candidate against Schistosoma japonicum. Previous studies have revealed that NP30 has an immunoregulatory effect, but the underlying mechanism for this effect remains unknown. This study shows that NP30 induces dendritic cell (DC) maturation and increases the production of pro‐inflammatory cytokines. The expression of CD86 and MHC II was upregulated in DCs following stimulation with NP30 in vitro. Moreover, NP30 induced Th17 polarization by increasing the production of IL‐6 and TGF‐β. In vivo, Th17 differentiation was induced by the production of key pro‐inflammatory cytokines, including IL‐6and TGF‐β, from DCs of NP30‐immunized mice. These results indicate that NP30 promotes Th17 polarization through DC activation, preventing serious schistosomiasis.

[Effects of three inducing factors on differentiation of bone marrow derived mesenchymal stem cells into lymphatic endothelial cells]

Objective: To observe the effects of basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), and vascular endothelial growth factor C (VEGF-C) on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into lymphatic endothelial cells (LECs). Methods: The third to the fifth passage of BMSCs of rats were collected for the following experiments. (1) BMSCs of rats were collected and divided into negative control group, CD90 group, CD44 group, and CD34 group according to the random number table (the same grouping method below), with 3 samples in each group. Phosphate buffer of 5 μL was added to cells in negative control group, and cells in the other 3 groups were added with 5 μL corresponding antibodies respectively. The positive expression of cell surface antigen was detected by flow cytometer. (2) BMSCs of rats in 3 batches were collected and divided into blank control group, VEGF-C group, HGF group, bFGF group, VEGF-C+ HGF group, VEGF-C+ bFGF group, HGF+ bFGF group, and VEGF-C+ HGF+ bFGF group, with 3 samples in each group. Cells in blank control group were added with 2 mL complete medium, cells in VEGF-C group were added with 2 mL complete medium and 10 μL VEGF-C of 10 μg/mL, cells in HGF group were added with 2 mL complete medium and 16 μL HGF of 10 μg/mL, and cells in bFGF group were added with 2 mL complete medium and 20 μL bFGF of 1 μg/mL. Cells in VEGF-C+ HGF group, VEGF-C+ bFGF group, HGF+ bFGF group, and VEGF-C+ HGF+ bFGF group were added with 2 mL complete medium and induction factors with corresponding concentration and volume as above. On 10 d of culture, the morphology of the cells was observed by the inverted phase contrast microscope, and the protein and mRNA expressions of lymphatic vessel endothelial hyaluronic acid receptor 1 (LYVE-1), VEGF receptor 3 (VEGFR3), and integrin α9 were detected by Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction respectively. (3) BMSCs of rats were collected and divided into blank control group, HGF+ VEGF-C+ bFGF group, bFGF+ VEGF-C+ HGF group, and VEGF-C+ HGF+ bFGF group, with 3 samples in each group. Cells in blank control group were added with 2 mL complete medium. Cells in HGF+ VEGF-C+ bFGF group were added with 2 mL complete medium, 16 μL HGF of 10 μg/mL, and 10 μL VEGF-C of 10 μg/mL, after 6 hours, 20 μL bFGF of 1 μg/mL was added. Cells in bFGF+ VEGF-C+ HGF group were added with 2 mL complete medium, 20 μL bFGF of 1 μg/mL, and 10 μL VEGF-C of 10 μg/mL, after 6 hours, 16 μL HGF of 10 μg/mL was added. Cells in VEGF-C+ HGF+ bFGF group were simultaneously added with 2 mL complete medium and the same concentration and volume of three inducing factors as above. In addition, BMSCs of rats in another 2 batches were collected and grouped, and they were dealt with the same methods as above except that the interval time of 6 hours in HGF+ VEGF-C+ bFGF group and bFGF+ VEGF-C+ HGF group was adjusted to 12 and 24 hours. On 10 d of culture, protein expressions of LYVE-1, VEGFR3, and integrin α9 were detected by Western blotting. Data were processed with analysis of variance of factorial design, one-way analysis of variance, and least significant difference t test, and Bonferroni correction. Results: (1) The positive expression rates of surface antigen of cells in negative control group, CD90 group, CD44 group, and CD34 group were 0.39%, 99.84%, 99.90%, and 0.57%, respectively. (2) On 10 d of culture, cells in blank control group, HGF group, bFGF group, and HGF+ bFGF group presented long fusiform, while cells in the other groups presented polygonal shape. (3) On 10 d of culture, there were no protein expressions of LYVE-1, VEGFR3, and integrin α9 in cells of blank control group, HGF group, bFGF group, and HGF+ bFGF group. On 10 d of culture, protein expressions of LYVE-1, VEGFR3, and integrin α9 in cells of VEGF-C+ HGF+ bFGF group were significantly higher than those in VEGF-C group (t=24.21, 11.04, 15.43, P<0.01), VEGF-C+ HGF group (t=10.81, 9.93, 10.20, P<0.01), and VEGF-C+ bFGF group (t=11.67, 6.32, 19.00, P<0.01). Protein expressions of LYVE-1 in cells of VEGF-C+ HGF group and VEGF-C+ bFGF group were significantly higher than the protein expression in VEGF-C group (t=8.69, 15.20, P<0.01). Protein expression of VEGFR3 in cells of VEGF-C+ bFGF group was obviously higher than the protein expressions in VEGF-C group and VEGF-C+ HGF group (t=8.67, 7.21, P<0.01). Protein expression of integrin α9 in cells of VEGF-C+ HGF group was obviously higher than the protein expressions in VEGF-C group and VEGF-C+ bFGF group (t=8.80, 8.83, P<0.01). (4) On 10 d of culture, there were no mRNA expressions of LYVE-1, VEGFR3, and integrin α9 in cells of blank control group, HGF group, bFGF group, and HGF+ bFGF group. On 10 d of culture, mRNA expressions of LYVE-1 and VEGFR3 in cells of VEGF-C group were significantly lower than those in VEGF-C+ bFGF group and VEGF-C+ HGF+ bFGF group (t(LYVE-1)=6.22, 18.01, t(VEGFR3)=8.49, 15.34, P<0.01), and mRNA expression of integrin α9 were significantly lower than that in VEGF-C+ HGF group and VEGF-C+ HGF+ bFGF group (t=13.24, 9.65, P<0.01). The mRNA expressions of LYVE-1, VEGFR3, and integrin α9 in cells of VEGF-C+ HGF+ bFGF group were obviously higher than those in VEGF-C+ HGF group and VEGF-C+ bFGF group (t=13.92, 11.95, 13.72, 5.27, 5.64, 9.10, P<0.01). Compared with those of VEGF-C+ bFGF group, the mRNA expression of VEGFR3 of cells in VEGF-C+ HGF group was significantly lower (t=6.91, P<0.01), while the mRNA expression of integrin α9 of cells in VEGF-C+ HGF group was significantly higher (t=11.69, P<0.01). (5) On 10 d of culture at interval time of 6, 12, 24 h, there were no protein expressions of LYVE-1, VEGFR3, or integrin α9 in cells of blank control group. On 10 d of culture at interval time of 6, 12, 24 h, the protein expressions of LYVE-1, VEGFR3, and integrin α9 in cells of HGF+ VEGF-C+ bFGF group, bFGF+ VEGF-C+ HGF group, and VEGF-C+ HGF+ bFGF group were close (F(6 h)=2.25, 2.47, 2.19, F(12 h)=2.93, 1.47, 3.25, F(24 h)=0.28, 0.20, 1.01, P>0.05). Conclusions: VEGF-C is a necessary factor for inducing BMSCs to differentiate into LECs. HGF and bFGF may promote the differentiation by up-regulating the expressions of integrin α9 and VEGFR3 respectively. But the induction effects of the two factors may be independent. The combination of VEGF-C, HGF, and bFGF have the best effects of promoting differentiation.

X-ray-induced reproductive dysfunction and differentially expressed piRNAs in male mice

The effects of X-ray radiation on spermatogenesis, sperm motility, and PIWI-interacting RNAs (piRNAs) in mice were analyzed. Male C57BL/6 J mice were divided into control and two irradiation groups ( n = 9 mice/group). After irradiation of their reproductive regions, the mice were fed for 3 days (irradiation group 1) or 7 days (control and irradiation group 2). The sperm viability, motility, velocity, and motion curve were analyzed. After piRNA expression profiling, quantitative reverse-transcription polymerase chain reaction was conducted for validation. Ionizing radiation led to vessel dilation and congestion, fewer spermatogenic cells, and reduced sperm production compared to the control. At 3 and 7 days postirradiation, the sperm count (grade d) increased while sperm viability and sperm lateral head displacement decreased. At 7 days, the sperm abnormality rate was higher compared to the control. Many piRNAs were differentially expressed after irradiation, including decreased and increased expression of mmu_piR_009082 and mmu_piR_020217, respectively. Downregulated piRNAs were involved in Rap1 signaling, non-homologous end-joining, hedgehog signaling, oxytocin signaling, and cholinergic synapse. Upregulated piRNAs participated in pathways including proteoglycans in cancer, phosphatidylinositol signaling, cGMP-PKG signaling, and stem cell pluripotency regulation. X-ray irradiation inhibited spermatogenesis and increased abnormal sperm rate in mice. piRNA-related signaling pathways may be involved in this process.

Clover-tagged porcine reproductive and respiratory syndrome virus infectious clones for rapid detection of virus neutralizing antibodies

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is a widespread disease that affects domestic pigs of all ages. Accurate and rapid detection of PRRSV specific neutralizing antibodies levels in a pig herd is beneficial for the evaluation of the herd's immunity to combat the specific viral infection. However, the current methods for viral detection, including fluorescent focus neutralization (FFN) and cytopathic effect (CPE) reduction neutralizing assays, are subjective and time-consuming. Therefore, a Clover-tagged PRRSV virus neutralization assay were developed that instrumentally measures the fluorescence signal of Clover stably expressing by a PRRSV infectious clone for at least 10 passages. Herein, the results showed that the proposed Clover-tagged PRRSV neutralization assay is reliable using instrumental measurements of the fluorescence signal of Clover and allows for rapid detection of neutralizing antibodies against PRRSV. The assay was evaluated by testing swine sera from experimental and field samples, and comparisons were made with the traditional FFN and CPE reduction assays. These results suggest that the Clover-tagged PRRSV infectious clone offers a fast and reliable testing method for neutralizing antibodies and could permit high-throughput screening of new antiviral agents.

Recombinant MYH9 protein C-terminal domain blocks porcine reproductive and respiratory syndrome virus internalization by direct interaction with viral glycoprotein 5

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important infectious diseases impacting the swine industry worldwide. Prevention and control of PRRS have been problematic, as vaccination has achieved little success. MYH9 (encoded by the gene MYH9) is an essential cellular factor for PRRS virus (PRRSV) infection. The MYH9 C-terminal domain (designated PRA) interacts with viral glycoprotein 5 (GP5), a major PRRSV envelope protein. In this study, we investigated whether soluble PRA could serve as a novel blocking agent of PRRSV infection. Our data showed that preincubation of PRRSV with PRA inhibited virus infection of susceptible cells in a dose-dependent manner. Notably, PRA also exhibited broad-spectrum ability to inhibit infection with diverse strains of both PRRSV genotype 1 and 2. Analysis of the interaction between PRA and PRRSV GP5 revealed that PRA is able to capture PRRSV virions. In conclusion, our data suggest that PRA could serve as a novel broad-spectrum inhibitor of infection by heterogeneous PRRSV strains in vivo.

Generation of murine macrophage-derived cell lines expressing porcine CD163 that support porcine reproductive and respiratory syndrome virus infection

Background

Porcine reproductive and respiratory syndrome virus (PRRSV) exhibits a highly restricted tropism for cells of the monocyte-macrophage lineage, utilizing porcine CD163 (pCD163) as an indispensable cellular receptor for infection. Transfection the gene of pCD163 into several non-permissive cell lines followed by protein expression confers susceptibility to PRRSV. A lack of specialized porcine antibody tools for use with existing porcine-derived primary cells and cell lines has hampered studies of both PRRSV pathogenesis and virus triggering of immune response cascades. Therefore, we constructed PRRSV-susceptible murine alveolar macrophage-derived MH-S and peritoneal macrophage-like RAW264.7 cell lines by achieving pCD163 cell surface expression in these cells. We then evaluated PRRSV susceptibility and cytokine expression patterns induced upon PRRSV infection of these pCD163-expressing cell lines.

Results

Growth of MH-S^CD163 and RAW264.7^CD163 cells was indistinguishable from growth of un-transfected parental cell lines. Meanwhile, various stages of the PRRSV replication cycle, including viral particle attachment, internalization, disassembly and infection were confirmed in both pCD163-transfected cell lines. Analysis of PRRSV replication using immunofluorescence staining of virus and viral titration of cell lysates demonstrated that both MH-S^CD163 and RAW264.7^CD163 cells supported replication of various genotype 2 PRRSV isolates. Moreover, PRRSV replication in MH-S^CD163 cells was similar to that observed in porcine alveolar macrophages (PAMs) and was more efficient than in RAW264.7^CD163 cells. However, peak virus titers in MH-S^CD163 cells were attained at 60 h post-infection (pi) versus 48 hpi in PAMs. Analysis of cytokine expression showed that post-PRRSV infection, mRNA expression patterns of anti-inflammatory cytokines (IL-4 and IL-10) and pro-inflammatory cytokines (TNF-α and IFN-γ) in MH-S^CD163 cells were more similar to those observed in PAMs versus levels in RAW264.7^CD163 cells.

Conclusions

MH-S and RAW264.7 cells were not susceptible to PRRSV infection until transfection and subsequent expression of pCD163 were achieved in these cell lines. The PRRSV-susceptible MH-S^CD163 cell line efficiently supported viral replication of various genotype 2 PRRSV isolates and exhibited similar cytokine expression patterns as observed in PAMs. In conclusion, this work describes the development of new tools to further understand PRRSV pathogenesis and immune response mechanisms to PRRSV infection.

Electronic supplementary material

The online version of this article (10.1186/s12896-017-0399-5) contains supplementary material, which is available to authorized users.

Effect of different levels of protein concentrates supplementation on the growth performance, plasma amino acids profile and mTOR cascade genes expression in early-weaned yak calves

Objective

This study evaluated the effects of different levels of protein concentrate supplementation on the growth performance of yak calves, and correlated the growth rate to changes occurring in the plasma- amino acids, -insulin profile, and signaling activity of mammalian target of rapamycin (mTOR) cascade to characterize the mechanism through which the protein synthesis can be improved in early weaned yaks.

Methods

For this study, 48 early (3 months old) weaned yak calves were selected, and assigned into four dietary treatments according to randomized complete block design. The four blocks were balanced for body weight and sex. The yaks were either grazed on natural pasture (control diet) in a single herd or the grazing yaks was supplemented with one of the three protein rich supplements containing low (17%; LP), medium (19%; MP), or high (21%; HP) levels of crude proteins for a period of 30 days.

Results

Results showed that the average daily gain of calves increased (0.14 vs 0.23–0.26 kg; p<0.05) with protein concentrates supplementation. The concentration of plasma methionine increased (p<0.05; 8.6 vs 10.1–12.4 μmol/L), while those of serine and tyrosine did not change (p>0.05) when the grazing calves were supplemented with protein concentrates. Compared to control diet, the insulin level of calves increased (p<0.05; 1.86 vs 2.16–2.54 μIU/mL) with supplementation of protein concentrates. Addition of protein concentrates up-regulated (p<0.05) expression of mTOR-raptor, mammalian vacuolar protein sorting 34 homolog, the translational regulators eukaryotic translation initiation factor 4E binding protein 1, and S6 kinase 1 genes in both Longissimus dorsi and semitendinosus. In contrast, the expression of sequestosome 1 was down-regulated in the concentrate supplemented calves.

Conclusion

Our results show that protein supplementation improves the growth performance of early weaned yak calves, and that plasma methionine and insulin concentrations were the key mediator for gene expression and protein deposition in the muscles.

Exogenous substances regulate silkworm fat body protein synthesis through MAPK and PI3K/Akt signaling pathways

Insect fat body is an important intermediate metabolic organ that plays an important role in protein metabolism and detoxification. In order to study the effects of TiO₂ NPs and phoxim on fat body protein synthesis through MAPK and PI3K/Akt signaling pathways in silkworms, we determined the effects of TiO₂ NPs and phoxim, alone and in combination, on fat body protein content of silkworms, analyzed the gene expression profile of the fat body, and verified the expression of characteristic genes. We found that TiO₂ NPs and phoxim alone increased the total protein content of the fat body, and up-regulated MAPK and PI3K/Akt signaling pathway genes. TiO₂ NPs up-regulated the expression of two growth and development-related genes-insulin-like peptide and neuropeptide receptor B-by 5.17 and 3.89-fold, respectively. Phoxim up-regulated the expression of detoxification genes-P450, GST, and CarE2. Pretreatment with TiO₂ NPs could reduce phoxim-increased total protein content and up-regulated MAPK and PI3K/Akt signaling pathway genes and detoxification genes; the activities of detoxification enzymes were consistent with the gene expression pattern. Our results showed that MAPK and PI3K/Akt signaling pathways both regulate fat body protein synthesis in silkworms, but the target proteins induced to express were different under different inducing factors. Our finding may provide a reference for investigating the mechanism of protein synthesis regulation through MAPK and PI3K/Akt signaling pathways.

Exposure to famine in early life and the risk of obesity in adulthood in Qingdao: Evidence from the 1959-1961 Chinese famine

BACKGROUND AND AIMS

We aimed to evaluate the association between famine exposure during early life and obesity and obesity_max (obese at the highest weight) in adulthood.

METHODS AND RESULTS

Data were from two population-based cross-sectional surveys conducted in 2006 and 2009 in Qingdao, China. A total of 8185 subjects born between 1/1/1941 and 12/31/1971 were categorized into unexposed (born between 01/01/1962 and 12/31/1971), fetal/infant exposed (born between 01/01/1959 and 12/31/1961), childhood exposed (born between 01/01/1949 and 12/31/1958) and adolescence exposed (born between 01/01/1941 and 12/31/1948) according to their age when exposed to the Chinese famine from 1959 to 1961. Obesity was defined as BMI (body mass index) ≥28.0 and obesity_max was defined as BMI_max (BMI at the highest weight) ≥28.0. We compared fetal/infant exposed, childhood exposed and adolescence exposed to the unexposed using logistic regression models to assess the effect of famine exposure on later obesity and obesity_max. Fetal/infant exposed (OR = 1.59, P < 0.001), childhood exposed (OR = 1.42, P < 0.01) and adolescence exposed (OR = 1.86, P < 0.01) all had higher risks of obesity than the unexposed. Exposure groups were more likely to be obese at their highest weight than the unexposed, and ORs (95%CIs) for obesity_max in the fetal/infant exposed, childhood exposed and adolescence exposed were 1.49(1.20-1.86), 1.24(1.02-1.49) and 1.64 (1.40-1.93), respectively. Similar results were found in both men and women.

CONCLUSION

Exposure to famine in early life was associated with increased risks of obesity and obesity_max in adulthood. Preventing undernutrition in early life appears beneficial to reduce the prevalence of later obesity.

G protein-coupled estrogen receptor is involved in modulating colonic motor function via nitric oxide release in C57BL/6 female mice

BACKGROUND

Estrogen may regulate gastrointestinal motor functions, but the mechanism(s) is not totally understood. Here, we investigated whether G protein-coupled estrogen receptor (GPER/GPR30) was involved in regulating colonic motor functions and explored the underlying physiological mechanisms.

METHODS

Adult female C57BL/6 mice were used. The expression and localization of GPER were examined by RT-PCR, western blot, and immuno-labeling. The role of GPER in modulating colonic motor functions was assessed by the bead propulsion test in vivo and organ bath experiments in vitro.

KEY RESULTS

GPER was expressed in colonic myenteric neurons. The colonic transit time (CTT) in proestrus and estrus was significantly longer than that in diestrus. In vivo treatment with the selective GPER blocker G15 significantly shortened CTT in proestrus and estrus. In ovariectomized mice, acute estrogen supplementation increased CTT, which could be abolished by G15 co-administration. The GPER agonist G-1 caused a concentration-dependent inhibition of carbachol -induced circular muscle strips contraction, which was abolished by tetrodotoxin and the neuronal nitric oxide synthase (nNOS) inhibitor N-propyl-l-arginine. G-1 stimulated NO production in isolated longitudinal muscle myenteric plexus and cultured myenteric neurons, which was dependent on nNOS. Immunofluorescence labeling showed co-localization of GPER with nNOS in the myenteric plexus.

CONCLUSIONS & INFERENCES

We suggest that activation of GPER exerts an inhibitory effect on colonic motility by promoting NO release from myenteric nitrergic nerves. These results raise a possibility that GPER may be involved in mediating the inhibitory effect of estrogen on colonic motor functions, via a non-genomic, neurogenic mechanism.

Rescue and evaluation of a recombinant PRRSV expressing porcine Interleukin-4

BACKGROUND

The current vaccines for porcine reproductive and respiratory syndrome virus (PRRSV) have failed to provide broad protection against infection by various strains of PRRSV. Porcine Interleukin-4 (pIL-4) plays an important role in the regulation of the immune response and has been used previously as an immunological adjuvant. The objective of this study was to construct a recombinant PRRSV expressing pIL-4 and to evaluate the immune response of the recombinant virus in piglets.

METHODS

The pIL-4 gene was inserted in the PRRSV (CH-1R strain) infectious clone by overlap PCR. Indirect immunofluorescence assay (IFA) and Western blotting were used to confirm the recombinant virus. The stability of the recombinant virus was assessed by DNA sequencing and IFA after 15 passages in vitro. Recombinant virus was injected into pigs and efficacy of immune protection was evaluated in comparison with the parental virus.

RESULTS

The recombinant virus (CH-1R/pIL-4) was successfully rescued and shown to have similar growth kinetics as the parental virus. The recombinant virus was stable for 15 passages in cell culture. Pigs vaccinated with CH-1R/pIL-4 produced a similar humoral response to the response elicited by parental virus, but IL-4 level in the supernatant of PBMCs from pigs vaccinated with CH-1R/pIL-4 was significantly higher than the parent virus at 28 days post-immunization (DPI). Flow cytometric (FCM) analysis showed that the percentage of CD4(+)CD8(+) double positive T (DPT) cells in the CH-1R/pIL-4 vaccinated group was significantly higher than the parental virus at 3 and 7 Days Post-Challenge (DPC), and the IL-4 level in the blood significantly increased at 7 DPC. However, the viral load and histopathology did not show significant difference between the two groups.

CONCLUSIONS

A recombinant PRRSV expressing porcine IL-4 was rescued and it remained genetically stable in vitro. The recombinant virus induced higher DPT ratios and IL-4 levels in the blood after HP-PRRSV challenge compared to the parental virus in piglets. However, it did not significantly improve protection efficacy of PRRSV vaccine.

Live-cell and super-resolution imaging reveal that the distribution of wall-associated protein A is correlated with the cell chain integrity of Streptococcus mutans

Streptococcus mutans is a primary pathogen responsible for dental caries. It has an outstanding ability to form biofilm, which is vital for virulence. Previous studies have shown that knockout of Wall-associated protein A (WapA) affects cell chain and biofilm formation of S. mutans. As a surface protein, the distribution of WapA remains unknown, but it is important to understand the mechanism underlying the function of WapA. This study applied the fluorescence protein mCherry as a reporter gene to characterize the dynamic distribution of WapA in S. mutans via time-lapse and super-resolution fluorescence imaging. The results revealed interesting subcellular distribution patterns of WapA in single, dividing and long chains of S. mutans cells. It appears at the middle of the cell and moves to the poles as the cell grows and divides. In a cell chain, after each round of cell division, such dynamic relocation results in WapA distribution at the previous cell division sites, resulting in a pattern where WapA is located at the boundary of two adjacent cell pairs. This WapA distribution pattern corresponds to the breaking segmentation of wapA deletion cell chains. The dynamic relocation of WapA through the cell cycle increases our understanding of the mechanism of WapA in maintaining cell chain integrity and biofilm formation.

Immune responses of pigs immunized with a recombinant porcine reproductive and respiratory syndrome virus expressing porcine GM-CSF

Porcine reproductive and respiratory syndrome virus (PRRSV) has spread worldwide, causing huge economic losses to the swine industry. The current PRRSV vaccines have failed to provide broad protection against various strains. Granulocyte macrophage colony-stimulating factor (GM-CSF), an efficacious adjuvant, has been shown to enhance the immunogenicity of various vaccines. The purpose of this study was to construct a recombinant live attenuated PRRSV that expresses porcine GM-CSF (pGM-CSF) and evaluate the immune responses of pigs immunized with the recombinant virus. The results showed that the recombinant PRRSV was successfully rescued and had similar growth properties to parental virus grown in Marc-145 cells. The recombinant virus was stable for 10 passages in cell culture. Pigs intramuscularly immunized with the recombinant virus produced a similar humoral response to that elicited using parental virus. With regard to cell-mediated immunity assessed in peripheral blood, the recombinant virus induced higher proportion of CD4(+)CD8(+) double-positive T cells (DPT), higher IFN-γ level at 0 and 7 days post-challenge (DPC), and lower viremia at 21 DPC than pigs immunized with parental virus. These results indicate that recombinant PRRSV expressing pGM-CSF can induce a significant higher cellular immune response and reduce the persistent infection compared pigs vaccinated with the parental virus. This is first report of evaluation of immune response in pigs elicited by a recombinant live attenuated PRRSV expressing porcine GM-CSF. It may represent a novel strategy for future development of genetic engineered vaccines against PRRSV infection.

Modulation of intestinal afferent nerve sensitivity to inflammatory mediators following systemic endotoxin in mice

BACKGROUND

Endotoxin exposure may be followed by visceral hypersensitvity but potential mechanisms are not fully explored. We aimed to test the hypothesis that mast cells and the cyclooxygenase pathway (COX) mediate modulation of afferent nerve sensitivity following systemic endotoxin.

METHODS

C57Bl6 mice received endotoxin injection i.p. to induce systemic inflammation. Control animals received normal saline. Extracellular multi-unit afferent nerve discharge was recorded from jejunal mesenteric nerves in vitro. Afferent nerve response to 5-hydroxytryptamine (5-HT, 250 μmol/L), bradykinin (BK, 0.5 μmol/L), and to mechanical ramp distension of the intestinal lumen from 0 to 60 cmH2O were recorded 2 h following endotoxin administration.

KEY RESULTS

Following endotoxin administration peak afferent discharge to 5-HT and BK was increased compared to controls (p < 0.05). Pre-perfusion with the mast cell stabilizer Doxantrazole (10(-4) M), or the cyclooxygenase inhibitor Naproxen inhibited the increased response to 5-HT and BK (p < 0.05 vs endotoxin pretreatment). Mechanosensitivity during luminal ramp distension from 10 to 60 cmH2O was increased following endotoxin pretreatment compared to controls (p < 0.05). This increase in sensitivity following endotoxin was no longer observed after Doxantrazole or Naproxen administration for pressures from 10 to 30 cmH2O (p < 0.05). Selective COX-2 inhibition by NS398 (10 μM) but not COX-1 inhibition by SC560 (300 μM) reduced increased afferent discharge in endotoxin pretreated animals to 5-HT, BK and mechanical ramp distension from 10 to 40 cmH2O (all p < 0.05).

CONCLUSIONS & INFERENCES

Systemic endotoxin sensitizes mesenteric afferent nerve fibers to 5-HT, BK and mechanical stimuli. The underlying mechanism responsible for this sensitization seems to involve mast cells and the COX-2 pathway.

Population pharmacokinetic analyses for BC-3781 using phase 2 data from patients with acute bacterial skin and skin structure infections

BC-3781, a pleuromutilin antimicrobial agent, is being developed for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia. Data from a phase 2 study of patients with ABSSSI were used to refine a previous population pharmacokinetic (PK) model and explore potential predictors of PK variability. The previously derived population PK model based on data from three phase 1 studies was applied to sparse sampling data from a phase 2 ABSSSI study and modified as necessary. Covariate analyses were conducted to identify descriptors (e.g., body size, renal function, age) associated with interindividual variability in PK. All population PK analyses were conducted by using Monte Carlo parametric expectation maximization implemented in S-ADAPT 1.5.6. The population PK data set contained 1,167 concentrations from 129 patients; 95% of the patients had 5 or more PK samples (median, 11). The previous population PK model (three-compartment model with first-order elimination and nonlinear protein binding) provided an acceptable and unbiased fit to the data from the 129 patients. Population PK parameters were estimated with acceptable precision; individual clearance values were particularly well estimated (median individual precision of 9.15%). Graphical covariate evaluations showed no relationships between PK and age or renal function but modest relationships between body size and clearance and volume of distribution, which were not statistically significant when included in the population PK model. This population PK model will be useful for subsequent PK-pharmacodynamic analyses and simulations conducted to support phase 3 dose selection. (This study has been registered at ClinicalTrials.gov under registration no. NCT01119105.).

Oxytocin down-regulates mesenteric afferent sensitivity via the enteric OTR/nNOS/NO/KATP pathway in rat

BACKGROUND

Oxytocin plays an analgesic role in modulation of nociception and pain. Most work to date has focused on the central mechanisms of oxytocin analgesia, but little is known about whether peripheral mechanisms are also involved.

METHODS

The mesenteric afferent discharge was recorded in vitro. The expressions of oxytocin receptor (OTR) and neuronal nitric oxide synthase (nNOS) in longitudinal muscle myenteric plexus (LMMP) was identified by immunofluorescence.

KEY RESULTS

Oxytocin per se had no effect on the jejunal mesenteric afferent discharge, however, it markedly attenuated the bradykinin- or distention-evoked increase of mesenteric afferent discharge, which was mimiced by the nitric oxide (NO) donor sodium nitroprusside (SNP). Pretreatment of either NOS inhibitor L-NAME or NPLA largely reduced the inhibitory effect of oxytocin on bradykinin-evoked mesenteric afferent discharge. Such effect, to a large extent, was also alleviated by N-and P-type voltage-dependent calcium channel antagonists or KATP blocker glibenclamide. In addition, immunofluorescence studies show strong colocalization of OTR with nNOS in LMMP of the rat jejunum.

CONCLUSIONS & INFERENCES

Oxytocin down-regulates the mesenteric afferent sensitivity through nNOS-NO-KATP pathway. Our findings may reveal a new peripheral mechanism for oxytocin analgesia.

Piperlongumine induces autophagy by targeting p38 signaling

Piperlongumine (PL), a natural product isolated from the plant species Piper longum L., can selectively induce apoptotic cell death in cancer cells by targeting the stress response to reactive oxygen species (ROS). Here we show that PL induces cell death in the presence of benzyloxycarbonylvalyl-alanyl-aspartic acid (O-methyl)-fluoro-methylketone (zVAD-fmk), a pan-apoptotic inhibitor, and in the presence of necrostatin-1, a necrotic inhibitor. Instead PL-induced cell death can be suppressed by 3-methyladenine, an autophagy inhibitor, and substantially attenuated in cells lacking the autophagy-related 5 (Atg5) gene. We further show that PL enhances autophagy activity without blocking autophagy flux. Application of N-acetyl-cysteine, an antioxidant, markedly reduces PL-induced autophagy and cell death, suggesting an essential role for intracellular ROS in PL-induced autophagy. Furthermore, PL stimulates the activation of p38 protein kinase through ROS-induced stress response and p38 signaling is necessary for the action of PL as SB203580, a p38 inhibitor, or dominant-negative p38 can effectively reduce PL-mediated autophagy. Thus, we have characterized a new mechanism for PL-induced cell death through the ROS-p38 pathway. Our findings support the therapeutic potential of PL by triggering autophagic cell death.

Identification of LRP16 as a negative regulator of insulin action and adipogenesis in 3T3-L1 adipocytes

Leukemia related protein 16 (LRP16) was first cloned from acute myeloid leukemia cells in our laboratory. In the present study, we sought to investigate the role of LRP16 in insulin action and sensitivity, using LRP16-depleted and -overexpressing 3T3-L1 cells. LRP16 silencing resulted in a reduction of the expression and secretion of tumor necrosis factor-alpha (TNF-α) and a concomitant increase in the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ). Moreover, LRP16 depletion promoted insulin-induced glucose uptake and adipocyte differentiation of 3T3-L1 cells. In contrast, LRP16 overexpression increased TNF-α secretion, suppressed glucose uptake, and attenuated 3T3-L1 cell differentiation. The phosphorylation levels of insulin receptor substrate 1 (IRS-1), phosphatidylinositide 3-kinase (PI3-K), and Akt were increased in LRP16-deficient 3T3-L1 cells, and conversely, diminished in LRP16-overexpressing 3T3-L1 cells, when compared to the corresponding control cells. Additionally, LRP16 overexpression raised the phosphorylation level of mammalian target of rapamycin (mTOR). The pretreatment with rapamycin, a specific inhibitor of mTOR, prevented the TNF-α elevation and PPAR-γ reduction and restored the phosphorylation of IRS-1, PI3-K, and Akt in LRP16-overexpressing cells. Our data collectively indicate that LRP16 acts as a negative regulator of insulin action and adipogenesis in 3T3-L1 adipocytes, which involves the activation of the mTOR signaling pathway.

Population pharmacokinetic analysis of clopidogrel in healthy Jordanian subjects with emphasis optimal sampling strategy

AIM

Clopidogrel is metabolized primarily into an inactive carboxyl metabolite (clopidogrel-IM) or to a lesser extent an active thiol metabolite. A population pharmacokinetic (PK) model was developed using NONMEM(®) to describe the time course of clopidogrel-IM in plasma and to design a sparse-sampling strategy to predict clopidogrel-IM exposures for use in characterizing anti-platelet activity.

METHODS

Serial blood samples from 76 healthy Jordanian subjects administered a single 75 mg oral dose of clopidogrel were collected and assayed for clopidogrel-IM using reverse phase high performance liquid chromatography. A two-compartment (2-CMT) PK model with first-order absorption and elimination plus an absorption lag-time was evaluated, as well as a variation of this model designed to mimic enterohepatic recycling (EHC). Optimal PK sampling strategies (OSS) were determined using WinPOPT based upon collection of 3-12 post-dose samples.

RESULTS

A two-compartment model with EHC provided the best fit and reduced bias in C(max) (median prediction error (PE%) of 9.58% versus 12.2%) relative to the basic two-compartment model, AUC(0-24) was similar for both models (median PE% = 1.39%). The OSS for fitting the two-compartment model with EHC required the collection of seven samples (0.25, 1, 2, 4, 5, 6 and 12 h). Reasonably unbiased and precise exposures were obtained when re-fitting this model to a reduced dataset considering only these sampling times.

CONCLUSIONS

A two-compartment model considering EHC best characterized the time course of clopidogrel-IM in plasma. Use of the suggested OSS will allow for the collection of fewer PK samples when assessing clopidogrel-IM exposures.

Mast cells and the cyclooxygenase pathway mediate colonic afferent nerve sensitization in a murine colitis model

INTRODUCTION

Intestinal inflammation alters colonic afferent nerve sensitivity which may contribute to patients' perception of abdominal discomfort. We aimed to explore whether mast cells and the cyclooxygenase pathway are involved in altered afferent nerve sensitivity during colitis.

METHODS

C57Bl6 mice received 3% dextran-sulfate sodium (DSS) in drinking water for 7 days to induce colitis. Control animals received regular water. On day 8 inflammation was assessed in the proximal colon by morphology and histology. Extracellular afferent nerve discharge was recorded from the mesenteric nerve of a 2 cm colonic segment. Subgroups were treated in vitro with the mast cell stabilizer doxantrazole (10⁻⁴M) or the cyclooxygenase inhibitor naproxen (10⁻⁵M).

RESULTS

DSS colitis resulted in morphological and histological signs of inflammation. At baseline, peak firing was 11±2 imp s⁻¹ in colitis segments and 5±1 imp s⁻¹ in uninflamed control segments (p<0.05; mean ± SEM; each n=6). In colitis segments, afferent nerve discharge to bradykinin (0.5 μM) was increased to 47±7 compared to 23±6 imp s⁻¹ in recordings from non-inflamed control tissue (p<0.05). Mechanosensitivity during luminal ramp distension (0-80 cm H₂O) was increased reaching 24±5 imp s⁻¹ at 80 cm H₂O during colitis compared to 14±2 in non-inflamed controls (p<0.05). Doxantrazole or naproxen reduced afferent discharge to bradykinin and luminal ramp distension in colitis segments to control levels.

CONCLUSION

Intestinal inflammation sensitizes mesenteric afferent nerve fibers to bradykinin and mechanical stimuli. The underlying mechanism responsible for this sensitization seems to involve mast cells and prostaglandins.