Genesis of the novel human-infecting influenza A(H10N8) virus and potential genetic diversity of the virus in poultry, China

Human infection with a novel influenza A(H10N8) virus was first described in China in December 2013. However, the origin and genetic diversity of this virus is still poorly understood. We performed a phylogenetic analysis and coalescent analysis of two viruses from the first case of influenza A(H10N8) (A/Jiangxi-Donghu/346-1/2013 and A/Jiangxi-Donghu/346-2/2013 and a novel A(H10N8) virus (A/chicken/Jiangxi/102/2013) isolated from a live poultry market that the patient had visited. The haemagglutinin (HA), neuraminidase (NA), PA subunit of the virus polymerase complex, nucleoprotein (NP), M and nonstructural protein (NS) genes of the three virus strains shared the same genetic origins. The origins of their HA and NA genes were similar: originally from wild birds to ducks, and then to chickens. The PA, NP, M, and NS genes were similar to those of chicken influenza A(H9N2) viruses. Coalescent analyses showed that the reassortment of these genes from A(H9N2) to A(H10N8) might have occurred at least twice. However, the PB1 and PB2 genes of the chicken A(H10N8) virus most likely originated from H7-like viruses of ducks, while those of the viruses from the case most likely stemmed from A(H9N2) viruses circulating in chickens. The oseltamivir-resistance mutation, R292K (R291K in A(H10N8) numbering) in the NA protein, occurred after four days of oseltamivir treatment. It seems that A(H10N8) viruses might have become established among poultry and their genetic diversity might be much higher than what we have observed.

β-Catenin-regulated ALDH1A1 is a target in ovarian cancer spheroids

Cancer cells form three dimensional (3D) multicellular aggregates (or spheroids) under non-adherent culture conditions. In ovarian cancer (OC), spheroids serve as a vehicle for cancer cell dissemination in the peritoneal cavity, protecting cells from environmental stress-induced anoikis. To identify new targetable molecules in OC spheroids, we investigated gene expression profiles and networks upregulated in three dimensional (3D) versus traditional monolayer culture conditions. We identified ALDH1A1, a cancer stem cell marker as being overexpressed in OC spheroids and directly connected to key elements of the β-catenin pathway. B-catenin function and ALDH1A1 expression were increased in OC spheroids vs. monolayers and in successive spheroid generations, suggesting that 3D aggregates are enriched in cells with stem cell characteristics. B-catenin knockdown decreased ALDH1A1 expression levels and β-catenin coimmunoprecipitated with the ALDH1A1 promoter, suggesting that ALDH1A1 is a direct β-catenin target. Both siRNA mediated β-catenin knockdown and A37, a novel ALDH1A1 small molecule enzymatic inhibitor described here for the first time, disrupted OC spheroid formation and cell viability (p<0.001). B-catenin knockdown blocked tumor growth and peritoneal metastasis in an OC xenograft model. These data strongly support the role of β-catenin regulated ALDH1A1 in the maintenance of OC spheroids and propose new ALDH1A1 inhibitors targeting this cell population.

Enhanced myeloid differentiation factor 88 promotes tumor metastasis via induction of epithelial-mesenchymal transition in human hepatocellular carcinoma

Metastasis is the leading cause of death in patients with hepatocellular carcinoma (HCC) after curative resection. Therefore, it is critical to understand the mechanisms underlying tumor metastasis in HCC. We have previously shown that elevated expression of myeloid differentiation factor 88 (MyD88) may promote tumor growth and metastasis in HCC. In this study, we reported that enhanced expression of MyD88 promoted epithelial–mesenchymal transition (EMT) properties and tumor-initiating capabilities in HCC cells. MyD88 was found to be able to interact with p85, a regulatory subunit of phosphoinositide 3-kinase (PI3-K), independent of TLR/IL-1R-mediated response and caused PI3-K/v-akt murine thymoma viral oncogene homolog (Akt) activation, which resulted in subsequent phosphorylation of glycogen synthase kinase-3β and stabilization of Snail, a critical EMT mediator. Consistently, we observed a significant correlation between MyD88 expression and p-Akt levels in a cohort of HCC patients, and found that the combination of these two parameters have better prognostic value for HCC patients. Taken together, these results suggest that elevated MyD88 may facilitate HCC metastasis by promoting EMT properties and tumor-initiating capabilities via PI3–K/Akt pathway.

Production and repair of implant-induced microdamage in the cortical bone of goats after long-term estrogen deficiency

SUMMARY

By using an ovariectomized goat model, we found that estrogen depletion decreases bone quality and makes it susceptible to screw-induced mechanical microdamage. Both diffuse microdamage and linear cracks accumulated up to 3 weeks after screw implantation, and the microdamage was repaired gradually after 4-8 months.

INTRODUCTION

The aim of this study was to observe the effect of long-term estrogen deficiency on the creation and repair of microdamage in cortical bone adjacent to bone screw.

METHODS

Cortical bone screws were placed in the tibial diaphyses 28 months after ovariectomy (OVX) or sham operation (Sham-Op) in female goats. The goats were euthanized at 0 day, 21 days, 4 months, and 8 months after screw implantation. Microdamage morphology and repair were examined in peri-screw bone using histomorphometric method, and the nanomechanical properties of peri-screw bone were examined with nanoindentation testing.

RESULTS

Tibiae from ovariectomized goats in which screws had been placed had significantly higher levels of diffuse microdamage and significantly more linear cracks than those from sham goats, and the diffuse microdamage was more obvious than linear cracks in the region adjacent to the implant. Both diffuse microdamage and linear cracks accumulated up to day 21 and then gradually repaired at 4 and 8 months after surgery. The trend for bone remodeling in each group was consistent with changes in the level of microdamage. Nanoindentation testing showed that both elastic modulus and hardness in peri-screw bone were significantly decreased in OVX group compared to Sham-Op group. The hardness and elastic modulus also showed a downward trend up to 4 months after screw implantation and then exhibited some recovery after 8 months.

CONCLUSIONS

Estrogen depletion decreases bone quality and makes it vulnerable to screw-induced mechanical damage, which may compromise the initial stability of an orthopedic implant.

A pilot study of the SARC-F scale on screening sarcopenia and physical disability in the Chinese older people

INTRODUCTION

The SARC-F scale is a newly developed tool to diagnose sarcopenia and obviate the need for measurement of muscle mass. SARC-F ≥ 4 is defined as sarcopenia. The questions of SARC-F cover physical functions targeting sarcopenia or initial presentation for sarcopenia. The aim of the study is to explore the application of SARC-F in the Chinese people.

METHODS

Two hundred thirty Chinese people over 65 years old were assessed by the SARC-F scale, PSMS, Lawton IADL and the shortened version of the falls efficacy scale-international(the short FES-I). Hospitalization was investigated. Physical performance and strength were measured. The association of SARC-F with other scales or tests was analyzed.

RESULTS

Poor physical performance and grip strength were associated with SARC-F ≥ 4 independently (P<0.005). The κ value for agreement of SARC-F ≥ 4 and cutoff points of tests were 0.391 to 0.635. The short FES-I were correlated to SARC-F scores (Spearman's coefficient 0.692). Poor PSMS and Lawton IADL scores were associated with SARC-F ≥ 4(P=0.000) and SARC-F ≥ 4 was associated with hospitalization in the past 2 years (P=0.000).

CONCLUSION

The SARC-F scale can identify old Chinese people with impaired physical function who may suffered from sarcopenia. SARC-F judgment reflects fear of falling, indicates the hospitalization events and is associated with ability of daily life. Thus, SARC-F may be a simple and useful tool for screening individuals with impaired physical function. Further studies on SARC-F in Chinese people would be worthy.

A rare loss-of-function SCN5A variant is associated with lidocaine-induced ventricular fibrillation

The human genome contains over 4 million variant sites, as compared to the reference genome, including rare sequence variants, which have the potential to exert large phenotypic effects, such as susceptibility to drug toxicity. We report identification and functional characterization of a rare non-synonymous (p.A1427S) variant in the SCN5A gene that was associated with incessant and lethal ventricular tachycardia and fibrillation after administration of lidocaine to a patient with acute myocardial infarction. The variant, located in a highly conserved domain distinct from the predicted lidocaine binding site, decreased peak current density of the sodium channel. With the increasing availability of the whole exome and whole genome sequencing data, it would be possible to identify and characterize rare variants in SCN5A that might predispose to lethal ventricular arrhythmias.

MiR-324-5p inhibits proliferation of glioma by target regulation of GLI1

OBJECTIVES

To study the effects of the miR-324-5p on the glioma cells proliferation via the targeted regulation of the glioma-associated oncogene 1.

METHODS

The luciferase reporter gene was used to test whether the glioma-associated oncogene 1 was the target of the miR-324-5p microRNA. The glioma-associated oncogene 1 expression was detected by Western blot. The proliferation and cell cycle were evaluated by MTT assay and flow cytometry.

RESULTS

The glioma-associated oncogene 1 is a target of the miR-324-5p. An over-expressed miR-324-5p could reduce the cell survival rate and increase the G1/G0 phase rate in the glioma cell lines.

CONCLUSIONS

The miR-324-5p can inhibit proliferation of the glioma cells via the targeted regulation of the glioma-associated oncogene 1.

Study of co-transplantation of SPIO labeled bone marrow stromal stem cells and Schwann cells for treating traumatic brain injury in rats and in vivo tracing of magnetically labeled cells by MRI

AIM

The aims of this study are to investigate the effects of co-transplantation Bone Marrow Stromal Stem Cells (BMSCs) and Schwann Cells (SCs) in treating rat traumatic brain injury (TBI), the migration of BMSCs in the brain, and whether co-transplantation treatment is superior to single transplantation.

MATERIALS AND METHODS

Superparamagnetic iron oxide (SPIO) labeled BMSCs and SCs were transplanted and co-transplanted into the rats with TBI. The neurological functions of the rats were evaluated by the NSS (Neurological Severity Score) at day 3, 7, 14, and 30. Moreover, 7.0T MRI (Magnetic Resonance Imaging) scan was conducted in order to observe the migration of the labeled BMSCs.

RESULTS

MRI scan showed that when SPIO labeled BMSCs were injected into the brain, T2WI (weighted image) showed low signals and these low signals migrated toward the lesion. The speed of migration was faster in the co-transplantation group than in the single transplantation group. NSS results showed that the prognosis was better in the co-transplantation group than in the single transplantation group at day 14 after injection.

CONCLUSIONS

The co-transplantation of BMSCs and SCs showed faster cell migration and better prognosis in rat TBI.

Phenotypic Identification of Spinal Cord-Infiltrating CD4+ T Lymphocytes in a Murine Model of Neuropathic Pain

BACKGROUND

Neuropathic pain is one of the most devastating kinds of chronic pain. Neuroinflammation has been shown to contribute to the development of neuropathic pain. We have previously demonstrated that lumbar spinal cord-infiltrating CD4⁺ T lymphocytes contribute to the maintenance of mechanical hypersensitivity in spinal nerve L5 transection (L5Tx), a murine model of neuropathic pain. Here, we further examined the phenotype of the CD4⁺ T lymphocytes involved in the maintenance of neuropathic pain-like behavior via intracellular flow cytometric analysis and explored potential interactions between infiltrating CD4⁺ T lymphocytes and spinal cord glial cells.

RESULTS

We consistently observed significantly higher numbers of T-Bet⁺, IFN-γ⁺, TNF-α⁺, and GM-CSF⁺, but not GATA3⁺ or IL-4⁺, lumbar spinal cord-infiltrating CD4⁺ T lymphocytes in the L5Tx group compared to the sham group at day 7 post-L5Tx. This suggests that the infiltrating CD4⁺ T lymphocytes expressed a pro-inflammatory type 1 phenotype (Th1). Despite the observation of CD4⁺ CD40 ligand (CD154)⁺ T lymphocytes in the lumbar spinal cord post-L5Tx, CD154 knockout (KO) mice did not display significant changes in L5Tx-induced mechanical hypersensitivity, indicating that T lymphocyte-microglial interaction through the CD154-CD40 pathway is not necessary for L5Tx-induced hypersensitivity. In addition, spinal cord astrocytic activation, represented by glial fibillary acidic protein (GFAP) expression, was significantly lower in CD4 KO mice compared to wild type (WT) mice at day 14 post-L5Tx, suggesting the involvement of astrocytes in the pronociceptive effects mediated by infiltrating CD4⁺ T lymphocytes.

CONCLUSIONS

In all, these data indicate that the maintenance of L5Tx-induced neuropathic pain is mostly mediated by Th1 cells in a CD154-independent manner via a mechanism that could involve multiple Th1 cytokines and astrocytic activation.

Jamming graphs: a local approach to global mechanical rigidity

We revisit the concept of minimal rigidity as applied to frictionless, repulsive soft sphere packings in two dimensions with the introduction of the jamming graph. Minimal rigidity is a purely combinatorial property encoded via Laman's theorem in two dimensions. It constrains the global, average coordination number of the graph, for example. However, minimal rigidity does not address the geometry of local mechanical stability. The jamming graph contains both properties of global mechanical stability at the onset of jamming and local mechanical stability. We demonstrate how jamming graphs can be constructed using local moves via the Henneberg construction such that these graphs fall under the jurisdiction of correlated percolation. We then probe how jamming graphs destabilize, or become unjammed, by deleting a bond and computing the resulting rigid cluster distribution. We also study how the system restabilizes with the addition of new contacts and how a jamming graph with extra (redundant) contacts destabilizes. The latter endeavor allows us to probe a disk packing in the rigid phase and uncover a potentially new diverging length scale associated with the random deletion of contacts as compared to the study of cut-out (or frozen-in) subsystems.

Simultaneous Quantification of Six Major Flavonoids From Fructus sophorae by LC-ESI-MS/MS and Statistical Analysis

A new, sensitive and selective high-performance liquid chromatography–tandem mass spectrometric method has been developed for the determination of six major flavonoids including sophoricoside, genistin, genistein, rutin, quercetin, kaempferol in Fructus sophorae. Principal component analysis and hierarchical clustering analysis were used to classify and differentiate these samples. Chromatographic separation was performed on a C₁₈ column with linear gradient elution of methanol and 0.05% acetic acid (v/v) at a flow rate of 0.8 ml/min. The detection was accomplished in the negative mode using multiple-reaction monitoring. The total run time was 8.0 min. Full validation of the assay was carried out including linearity, precision, accuracy, recovery, limit of detection and limit of quantification. The validated method was successfully applied to the simultaneous determination of these active components in Fructus sophorae. The results demonstrated that the quantitative difference in content of six active compounds was useful for chemotaxonomy of many samples from different sources and the standardization and differentiation of many similar samples. Simultaneous quantification of bioactive components by high-performance liquid chromatography–tandem mass spectrometric method coupled with chemometric techniques would be a well-acceptable strategy to comprehensively control the quality of Fructus sophorae.

SIRT1 negatively regulates amyloid-beta-induced inflammation via the NF-κB pathway

Chronic inflammation induced by amyloid-beta (Aβ) plays a key role in the development of age-related macular degeneration (AMD), and matrix metalloproteinase-9 (MMP-9), interleukin (IL)-6, and IL-8 may be associated with chronic inflammation in AMD. Sirtuin 1 (SIRT1) regulates inflammation via inhibition of nuclear factor-kappa B (NF-κB) signaling, and resveratrol has been reported to prevent Aβ-induced retinal degeneration; therefore, we investigated whether this action was mediated via activation of SIRT1 signaling. Human adult retinal pigment epithelial (RPE) cells were exposed to Aβ, and overactivation and knockdown of SIRT1 were performed to investigate whether SIRT1 is required for abrogating Aβ-induced inflammation. We found that Aβ-induced RPE barrier disruption and expression of IL-6, IL-8, and MMP-9 were abrogated by the SIRT1 activator SRT1720, whereas alterations induced by Aβ in SIRT1-silenced RPE cells were not attenuated by SRT1720. In addition, SRT1720 inhibited Aβ-mediated NF-κB activation and decrease of the NF-κB inhibitor, IκBα. Our findings suggest a protective role for SIRT1 signaling in Aβ-dependent retinal degeneration and inflammation in AMD.

PAK4 kinase-mediated SCG10 phosphorylation involved in gastric cancer metastasis

Superior cervical ganglia 10 (SCG10), as a microtubule (MT) destabilizer, maintains MT homeostasis and has a critical role in neuronal development, but its function in tumorigenesis has not been characterized. In the present study, we demonstrated that p21-activated kinase 4 (PAK4)-mediated SCG10 phosphorylation regulates MT homeostasis in metastatic gastric cancer. Our results indicate that SCG10 is a physiological substrate of PAK4, which is phosphorylated on serine 50 (Ser50) in a PAK4-dependent manner. Phosphorylated SCG10 regulated MT dynamics to promote gastric cancer cell migration and invasion in vitro and metastasis in a xenograft mouse models. Inhibiting PAK4, either by LCH-7749944 or RNA interference, resulted in the inhibition of Ser50 phosphorylation and a blockade to cell invasion, suggesting that PAK4-SCG10 signaling occurs in gastric cancer cell invasion. Moreover, we demonstrated a strong positive correlation between PAK4 and phospho-Ser50 SCG10 expression in gastric cancer samples. We also showed that high expression of SCG10 phospho-Ser50 is highly correlated to an aggressive phenotype of clinical gastric cancer. These findings revealed a novel function of SCG10 in promoting invasive potential of gastric cancer cells, suggesting that blocking PAK4-mediated SCG10 phosphorylation might be a potential therapeutic strategy for metastasis of gastric cancer.

Catalase abrogates β-lapachone-induced PARP1 hyperactivation-directed programmed necrosis in NQO1-positive breast cancers

Improving patient outcome by personalized therapy involves a thorough understanding of an agent's mechanism of action. β-Lapachone (clinical forms, Arq501/Arq761) has been developed to exploit dramatic cancer-specific elevations in the phase II detoxifying enzyme NAD(P)H:quinone oxidoreductase (NQO1). NQO1 is dramatically elevated in solid cancers, including primary and metastatic [e.g., triple-negative (ER-, PR-, Her2/Neu-)] breast cancers. To define cellular factors that influence the efficacy of β-lapachone using knowledge of its mechanism of action, we confirmed that NQO1 was required for lethality and mediated a futile redox cycle where ∼120 moles of superoxide were formed per mole of β-lapachone in 2 minutes. β-Lapachone induced reactive oxygen species (ROS), stimulated DNA single-strand break-dependent poly(ADP-ribose) polymerase-1 (PARP1) hyperactivation, caused dramatic loss of essential nucleotides (NAD(+)/ATP), and elicited programmed necrosis in breast cancer cells. Although PARP1 hyperactivation and NQO1 expression were major determinants of β-lapachone-induced lethality, alterations in catalase expression, including treatment with exogenous enzyme, caused marked cytoprotection. Thus, catalase is an important resistance factor and highlights H2O2 as an obligate ROS for cell death from this agent. Exogenous superoxide dismutase enhanced catalase-induced cytoprotection. β-Lapachone-induced cell death included apoptosis-inducing factor (AIF) translocation from mitochondria to nuclei, TUNEL+ staining, atypical PARP1 cleavage, and glyceraldehyde 3-phosphate dehydrogenase S-nitrosylation, which were abrogated by catalase. We predict that the ratio of NQO1:catalase activities in breast cancer versus associated normal tissue are likely to be the major determinants affecting the therapeutic window of β-lapachone and other NQO1 bioactivatable drugs.