RNA-binding Protein QKI Inhibits Osteogenic Differentiation Via Suppressing Wnt Pathway

BACKGROUND

Dysregulation of MSCs differentiation is associated with many pathophysiological processes. Genetically modified MSCs transplantation helps restore bone loss efficiently.

METHODS

BMSCs-specific QKI overexpressing and knockdown mice were built to explore QKI's role in bone formation and fat accumulation. Primary BMSCs with QKI overexpression and knockout were subjected to osteogenic and adipogenic differentiation. ALP staining and oil red O staining were performed to evaluate the differences between the groups. RNA immunoprecipitation was performed to identify the QKI-related pathway. QKI deficient BMSCs were transplanted into mice with glucocorticoid-induced osteoporosis to evaluate its therapeutic potential.

RESULTS

Mice harboring BMSC-specific transgenic QKI exhibited reduced bone mass, while BMSC-specific QKI-deficient mice showed an increase in bone mass. Osteogenic differentiation of QKI deficient BMSCs was promoted and adipogenic differentiation was inhibited, while QKI overexpression in BMSCs displayed the opposite effects. To define the underlying mechanisms, RIP sequencing was performed. Wnt pathway-related genes were the putative direct target mRNAs of QKI, Canonical Wnt pathway activation was involved in QKI's effects on osteogenic differentiation. RNA immunoprecipitation quantitative real-time Polymerase Chain Reaction (PCR) and RNA fluorescence in situ hybridization experiments further validated that QKI repressed the expressions of Wnt5b, Fzd7, Dvl3 and β-catenin via direct binding to their putative mRNA specific sites. Glucocorticoid-induced osteoporotic mice transplanted with QKI deficient BMSCs exhibited less bone loss compared with mice transplanted with control BMSCs.

CONCLUSIONS

QKI suppressed BMSCs osteogenic differentiation by downregulating the expressions of Wnt5b, Fzd7, Dvl3 and β-catenin. Loss of QKI in BMSCs transplantation may provide a new strategy for the treatment of orthopedic diseases such as osteoporosis.

Current study on the influence of psychological factors on returning to sports after ACLR

It is considered that psychological factors are important in determining exercise regression outcomes of patients with anterior cruciate ligament reconstruction (ACLR). This review summarizes the definition and research progress of current undefined psychological factors related to returning to sports (RTS) after ACLR, as well as the application of corresponding measuring scales, and common psychological interventions in the field. The aim is to understand and clarify the impact of psychological factors in the ACL injury and rehabilitation, and to provide a theoretical basis for the application of psychological evaluation and intervention in the later stage. It is believed that there are still many prospects for the research in this field.

AQP5 Is a Novel Prognostic Biomarker in Pancreatic Adenocarcinoma

Background

Pancreatic adenocarcinoma (PAAD) is a highly malignant tumor with a poor prognosis. The identification of effective molecular markers is of great significance for diagnosis and treatment. Aquaporins (AQPs) are a family of water channel proteins that exhibit several properties and play regulatory roles in human carcinogenesis. However, the association between Aquaporin-5 (AQP5) expression and prognosis and tumor-infiltrating lymphocytes in PAAD has not been reported.

Methods

AQP5 mRNA expression, methylation, and protein expression data in PAAD were analyzed using GEPIA, UALCAN, HAP, METHSURV, and UCSC databases. AQP5 expression in PAAD patients and cell lines from our cohort was examined using immunohistochemistry and Western blotting. The LinkedOmics database was used to study signaling pathways related to AQP5 expression. TIMER and TISIDB were used to analyze correlations among AQP5, tumor-infiltrating immune cells, and immunomodulators. Survival was analyzed using TCGA and Kaplan-Meier Plotter databases.

Results

In this study, we investigated AQP5 expression in PAAD and determined whether the expression of AQP5 is a strong prognostic biomarker for PAAD. We searched and analyzed public cancer databases (GEO, TCGA, HAP, UALCAN, GEPIA, etc.) to conclude that AQP5 expression levels were upregulated in PAAD. Kaplan-Meier curve analysis showed that high AQP5 expression positively correlated with poor prognosis. Using TIMER and TISIDB, we found that the expression of AQP5 was associated with different tumor-infiltrating immune cells, especially macrophages. We found that hypomethylation of the AQP5 promoter region was responsible for its high expression in PAAD.

Conclusions

AQP5 can serve as a novel biomarker to predict prognosis and immune infiltration in PAAD.

Theoretical Study of O-CH3 Bond Dissociation Enthalpy in Anisole Systems

Understanding ubiquitous methyl transfer reactions requires a systematic study of thermodynamical parameters that could reveal valuable information about the nature of the chemical bond and the feasibility of those processes. In the present study, the O-CH₃ bond dissociation enthalpies (BDEs) of 67 compounds belonging to phenol/anisole systems were calculated employing the Gaussian-4 (G4) method. Those compounds contain different substituents including alkyl groups, electron-donating groups (EDGs), and electron-withdrawing groups (EWGs). The results show that the bigger branched alkyl groups and EDGs will destabilize the O-CH₃ bond, while EWGs have the opposite effect. A combination of different effects including steric effects, hydrogen bonds, and substituents and their position can achieve around 20 kcal/mol difference compared to the basic phenyl frame. Also, the linear correlation between σ_p ⁺ and O-CH₃ BDE can provide a reference for the O-CH₃ BDE prediction. The present study represents a step forward to establish a comprehensive O-CH₃ BDE database to understand the substituent effect and make its contribution to the rational design of inhibitors and drugs.

Association between the inclination angle of the proximal tibiofibular joint surface and medial compartment knee osteoarthritis

BACKGROUND

Fibular support for the lateral tibial plateau through the proximal tibiofibular joint (PTFJ) results in nonuniform settlement of the tibial plateau in middle-aged and elderly persons and may lead to medial compartment knee osteoarthritis. However, the inclination angle of the PTFJ surface varies widely and may affect nonuniform settlement. The purpose of this case-control study was to assess the association between the inclination angle of the PTFJ surface and medial compartment knee osteoarthritis.

METHODS

The fibular inclination angle (FIA) and tibial inclination angle (TIA) of the PTFJ surface were measured using radiographs. Differences of FIA and TIA among groups were assessed with t tests and the odds ratios (ORs) for risk factors of medial compartment knee osteoarthritis were calculated with binary logistic regression analysis.

RESULTS

Forty patients and 40 control participants were included in this case-control study. Patients had both a lower FIA (P=0.005) and TIA (P=0.000) than the controls, and logistic regression analysis showed that FIA (OR =7.000) and TIA (OR =17.000) were risk factors for medial compartment knee osteoarthritis.

CONCLUSIONS

A lower inclination angle of the PTFJ surface is associated with a risk of medial compartment knee osteoarthritis. Clinically, early prevention of medial compartment knee osteoarthritis should be considered for middle-aged and elderly persons with low PTFJ inclination angles.

Loss of QKI in macrophage aggravates inflammatory bowel disease through amplified ROS signaling and microbiota disproportion

Inflammatory bowel disease (IBD) is a refractory chronic inflammatory illness of the gastrointestinal (GI) tract. Macrophage exerts an important role in IBD development. QKI, as an RNA binding protein, was related with inflammatory responses in bacterial infections by regulating the polarization of macrophages. Therefore, we suspected that QKI-regulated macrophages have the potential to play a certain role in IBD and the underlying mechanism. Our results demonstrated that the mice with macrophage-specific deletion of QKI induced with dextran sodium sulfate (DSS) are more susceptible to IBD development, exhibited a severe leaky gut barrier phenotype and higher intense oxidative stress, which are rescued by treating with butylated hydroxyanisole (BHA), an agonist of NRF2. Mechanically, we observed that Keap1 mRNA in the nucleus was exported to the cytoplasm after LPS stimuli in parallel with QKI reductions, and the removal of QKI by shRNA facilitated Keap1 mRNA nuclear exporting and expression in cytoplasm, consequently NRF2 activation in nucleus was weakened, and led to the impaired antioxidant abilities. In addition, mice models of fecal microbiota transplant (FMT) and the co-culturing of mice epithelia cells with feces derived from the DSS-treated QKI-deficit mice revealed consistently aggravated colitis along with a severe oxidative stress; 16S sequencing analysis substantiated the altered compositions of commensal bacteria too. Overall, the current study represents the first effort to explore the anti-oxidant role of QKI in the intestinal macrophage via post-transcriptional regulation of Keap1 mRNA localization and the relevant NRF2 antioxidant signaling, and the disproportional changes in the microbiota were attributable to the mediation of pathogenic damage in the IBD development of QKI-deficit mice.

QKI deficiency leads to osteoporosis by promoting RANKL-induced osteoclastogenesis and disrupting bone metabolism

Quaking (QKI), an RNA-binding protein, has been reported to exhibit numerous biological functions, such as mRNA regulation, cancer suppression, and anti-inflammation. However, little known about the effects of QKI on bone metabolism. In this study, we used a monocyte/macrophage-specific QKI knockout transgenic mouse model to investigate the effects of QKI deficiency on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. The loss of QKI promoted the formation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts (OCs) from bone marrow macrophages, and upregulated the expression of OC-specific markers, including TRAP (Acp5) and cathepsin K (Ctsk). The pro-osteoclastogenesis effect of QKI deficiency was achieved by amplifying the signaling cascades of the NF-κB and mitogen-activated protein kinase (MAPK) pathways; then, signaling upregulated the activation of nuclear factor of activated T cells c1 (NFATc1), which is considered to be the core transcription factor that regulates OC differentiation. In addition, QKI deficiency could inhibit osteoblast (OB) formation through the inflammatory microenvironment. Taken together, our data suggest that QKI deficiency promoted OC differentiation and disrupted bone metabolic balance, and eventually led to osteopenia under physiological conditions and aggravated the degree of osteoporosis under pathological conditions.

Disease Progression-Dependent Expression of CD200R1 and CX3CR1 in Mouse Models of Parkinson's Disease

Microglial activation is an important contributor to the pathogenesis of Parkinson’s disease (PD). Microglia are tightly and efficiently regulated by immune checkpoints, including CD200-CD200R1 and CX3CL1-CX3CR1. Understanding the involvement of these checkpoints in disease progression provides important insights into how microglial activation contributes to PD pathology. However, so far, studies have produced seemingly conflicting results. In this study, we demonstrate that CD200R1 expression is down-regulated at both early and late stage of PD model, and CX3CR1 expression is down-regulated in early stage and recovered in late stage. In primary cultured microglia, CD200R1 and CX3CR1 expressions are both directly regulated by LPS or α-synuclein, and CD200R1 expression is more sensitively regulated than CX3CR1. In addition, CD200 knockout causes an increase in proinflammatory cytokine production and microglial activation in the midbrain. Remarkably, DA neurons in the substantial nigra are degenerated in CD200^-/- mice. Finally, activation of the CD200R with CD200Fc alleviates the neuroinflammation in microglia. Together, these results suggest that immune checkpoints play distinct functional roles in different stage of PD pathology, and the CD200-CD200R1 axis plays a significant role in nigrostriatal neuron viability and function.

CD200 maintains the region-specific phenotype of microglia in the midbrain and its role in Parkinson's disease

Microglia are a specialized population of tissue macrophages in the mammalian brain. Microglial phenotype is tightly regulated by local environmental factors, although little is known about these factors and their region-preferred roles in regulating local neuroinflammatory responses. We hypothesized that microglia in different brain regions respond differently to neuroinflammatory stimulation and that CD200, an anti-inflammatory protein mainly originated from neurons, acts as a local cue inhibiting microglia activation in the midbrain. We utilized a CD200-deficient mouse line to analyze the phenotypic role of CD200 in the regulation of normal neuron-microglia homeostasis in the midbrain and in the dopaminergic degeneration in an α-synuclein overexpression model of PD. We found that systemic administration of an endotoxin lipopolysaccharide induced a region-preferred change in CD200 expression in the midbrain. Similarly, CD200^-/- mice showed a regional preference in an enhancement of microglia activation and baseline inflammatory levels in the midbrain and dopamine neuron loss in the substantia nigra (SN). In a mouse model of Parkinson's disease (PD) induced by rAAV-hSYN injection into the SN, CD200^-/- mice showed more dopamine neuron loss in the SN than wild type mice. Activation of CD200 receptors with a CD200 fusion protein alleviated the neuroinflammation and neuronal death in the SN of PD mice. These findings demonstrate that CD200 is essential for the midbrain homeostasis and acts as a critical local regulator in controlling microglial properties related to the PD pathogenesis.

MOTS-c inhibits Osteolysis in the Mouse Calvaria by affecting osteocyte-osteoclast crosstalk and inhibiting inflammation

The Mitochondrial-derived peptide MOTS-c has recently been reported as a 16-amino acid peptide regulating metabolism and homeostasis in different cells. However, its effects on immune cells and bone metabolism are rarely reported. Here we demonstrate that MOTS-c treatment in ultra-high molecular weight polyethylene (UHMWPE) particle-induced osteolysis mouse model alleviated bone erosion and inflammation. MOTS-c increased osteoprotegerin (OPG)/ receptor activator of nuclear factor kappa-B ligand (RANKL) ratio in osteocytes, leading to inhibition of osteoclastogenesis. In primary bone marrow macrophages (BMMs) MOTS-c alleviated STAT1 and NF-κB phosphorylation triggered by UHMWPE particles. Promoting ROS production or suppressing peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) repression blocked these anti-inflammatory effects of MOTS-c treatment. Taken together, these findings provide evidence that the small peptide inhibits osteoclastogenesis by regulating osteocyte OPG/RANKL secretion and suppressing inflammation via restraining NF-κB and STAT1 pathway. Moreover, its effects on NF-κB activation is dependent on the AMPK-PGC-1α-ROS axis, suggesting its potential use in osteolysis and other inflammation disorders.

A theoretical model to estimate inactivation effects of OH radicals on marine Vibrio sp. in bubble-shock interaction

A theoretical model for estimating inactivation effects on marine Vibrio sp. is developed from the viewpoint of the chemical action of the OH radicals induced by interaction of bubbles with shock waves. It consists of a biological probability model for cell viability and a bubble dynamic model for its collapsing motion due to the shock pressures. The biological probability model is built by defining a sterilized space of the OH radicals. To determine the radius of the sterilized space, the Herring equation is solved in the bubble dynamic model in consideration of the effect of the heat conductivity and mass transportation. Furthermore, the pressure waveform of incident shock wave used in the model is obtained with the pressure measurement. On the other hand, a bio-experiment of marine Vibrio sp. is carried out using a high-voltage power supply in a cylindrical water chamber. Finally, the viability ratio of marine bacteria estimated by the theoretical model is examined under the experimental conditions of this study. In addition, we also discuss the influence of bubble initial size for predicting the inactivation effects.

Abstract P1-03-03: Invasive lobular carcinoma and invasive ductal carcinoma differ in immune response, translation efficiency and metabolic rate

Background

Invasive lobular carcinoma (ILC) is the second most common histological subtype of breast cancer after invasive ductal carcinoma (IDC). ILC differs from IDC in pathologic, molecular, and clinical features. ILC tumors are most often characterized as luminal A by PAM50 analysis, suggestive of an indolent disease. Yet, when matched for receptor status and tumor grade, patients with ILC tend to have worse long-term outcomes than patients with IDC. The main distinguishing molecular feature of ILC is the loss of functional E-cadherin, and yet, beyond that loss, the mechanisms underlying the differences between ILC and IDC are largely unknown. We examined the RNA expression profiles of ILC and IDC tumors to assess if there may be underlying vulnerabilities of ILC tumors to novel therapeutic strategies.

Methods

Differential expression analysis was performed on 159 luminal A (LumA) ILC tumors versus 311 LumA IDC tumors from The Cancer Genome Atlas (TCGA). The METABRIC cohort (65 LumA ILC and 533 LumA IDC) was used as a validation dataset. Pathway enrichment analysis was performed to identify potential differences in biological processes, and these potential differences were then tested in a series of in vitro experiments, using 3 ER+ ILC (MDA-MB-134VI, SUM44PE, and MDA-MB-330) and 3 ER+ IDC (MCF7, T47D, and ZR75.1) cell lines.

Results

Pathway analysis led to the identification of three main signaling differences between LumA ILC and LumA IDC: immune regulation, translation, and metabolism. A series of immune pathways, including Immunological Synapse, Biocarta IL17 pathway, and Response to Wounding were up-regulated in ILC tumors. We examined specific cell type markers, and found that ILC tumors have a higher activity of nearly all immune cell types, including CD4+ T cells, CD8+ T cells, B cells, NK cells, dendritic cells, M1 macrophages, and M2 macrophages. These results were surprising, since ILC tumors have a lower incidence of stromal inflammation, as defined by H&E staining, suggesting a unique immune regulatory mechanism in ILC.

Next, we examined the translational regulation in ILC vs IDC tumors by comparing RNA expression and protein quantities as determined by RPPA analysis. ILC tumors have a lower protein:RNA ratio, suggesting a lower translation efficiency. This was reflected in the RPPA data by lower protein expression of eIF4G, ribosome protein S6 (S6) and p70-S6K in ILC tumors. Phosphorylation of 4E-BP1 (Ser65), eEF2, S6 (Ser235/236, Ser240/244), and mTOR (Ser2448) were also significantly lower in LumA ILCs. This lower translation efficiency was then validated in cell lines by O-propargyl-puromycin treatment.

Finally, the pathway analysis suggested lower rates of metabolism in lobular tumors. Comparative studies of OXPHOS and glycolysis with a Seahorse analyzer confirmed this finding.

Conclusions

ILC tumors have a higher immune activity than IDC tumors, even with lower rates of stromal inflammation, suggesting a potential for differential response to immunotherapy. The lower rates of translation and metabolism, which are general identifiers of tumor dormancy, could enable ILC to escape from cytotoxic therapies, and may play an important role in the late recurrence of ILC.

Citation Format: Levine KM, Du T, Zhu L, Tasdemir N, Lee AV, Van Houten B, Tseng GC, Oesterreich S. Invasive lobular carcinoma and invasive ductal carcinoma differ in immune response, translation efficiency and metabolic rate [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-03-03.

HOXA10 promotes nasopharyngeal carcinoma cell proliferation and invasion via inducing the expression of ZIC2

OBJECTIVE

In this study, we aimed to explore the dysregulated genes in nasopharyngeal carcinoma (NPC) and to investigate the regulative effect of HOXA10 on ZIC2 expression and their involvement in NPC cell proliferation and invasion.

MATERIALS AND METHODS

Microarray data that compared the transcription profile of NPC tissues and normal tissues was searched in GEO datasets and was re-analyzed. The expression of HOXA10 and ZIC2 mRNA were retrieved in TCGA database. CNE1 and CNE2 cells were used as an in-vitro cell model. Luciferase reporters carrying truncated ZIC2 promoter sequences were generated to verify the predicted HOXA10 binding site. CCK-8 assay and transwell assay were applied to assess cell proliferation and invasion respectively.

RESULTS

HOXC6, HOXA3, and HOXA10 were upregulated in NPC tissues. Data mining in TCGA database showed that HOXA10, but not HOXC6 or HOXA3 is positively correlated to ZIC2 expression. Enforced HOXA10 expression significantly elevated ZIC2 expression at both mRNA and protein levels in both CNE1 and CNE2 cells. HOXA10 can directly bind to the promoter of ZIC2 and upregulate ZIC2 transcription. ZIC2 knockdown significantly reduced cell proliferation and invasion capability of CNE1 cells and also partly abrogated the effect of HOXA10 overexpression on enhancing cell proliferation and invasion.

CONCLUSIONS

Both HOXA10 and ZIC2 are upregulated in NPC tissues compared to the normal tissues. HOXA10 can increase ZIC2 expression via binding to the ZIC2 promoter. Functionally, the HOXA10-ZIC2 axis can enhance NPC cell proliferation and invasion.

Sex differences in the impact of nonalcoholic fatty liver disease on cardiovascular risk factors

BACKGROUND AND AIMS

Information on sex differences in the association of nonalcoholic fatty liver disease (NAFLD) with cardiovascular disease (CVD) risk factors is scarce. We examined whether men exhibit greater differences in established CVD risk factors between NAFLD and non-NAFLD than women.

METHODS AND RESULTS

We conducted a cross-sectional analysis using a cohort of 10761 apparently healthy Chinese adults who underwent comprehensive health checkups including abdominal ultrasonography. In the setting of NAFLD and non-NAFLD, although men had significantly higher levels of atherogenic lipids as indicated by higher levels of triglyceride, triglyceride/HDL-cholesterol, and lower levels of HDL-cholesterol and worsen renal function as indicated by higher levels of creatinine and lower levels of estimated glomerular filtration rate (eGFR) than female counterparts, men with NAFLD showed greater relative differences in atherogenic lipids and deteriorated renal function than women with NAFLD when compared with their non-NAFLD counterparts. The interactions between sex and NAFLD on triglyceride, HDL-cholesterol, triglyceride/HDL-cholesterol, creatinine, and eGFR were statistically significant (P < 0.05). In the multivariate Logistic regression analyses, we observed a stronger association of TG with NAFLD and comparable associations of eGFR or HDL-C with NAFLD in men compared with women.

CONCLUSION

There was greater adverse influence of NAFLD per se on triglyceride, and triglyceride/HDL-cholesterol in men compared with women. The greater adverse influence of NAFLD per se on HDL-C and eGFR in men compared with women probably related to the gender differences in TG levels.

A Systematic Review of Anterior Cruciate Ligament Femoral Footprint Location Evaluated by Quadrant Method for Single-Bundle and Double-Bundle Anatomic Reconstruction

PURPOSE

To unravel the standard position of anterior cruciate ligament (ACL) femoral origin and deduce practical arthroscopic localization and postsurgical evaluation method.

METHODS

Two independent reviewers searched PubMed using the terms ACL, footprint, femur, etc. We included studies published since January 1, 2000, in which the results were measured by Bernard's quadrant method. This method consists of 4 distances, including total diameter of lateral condyle along Blumensaat's line (distance t), maximum intercondylar notch height (distance h), distance from center of footprint to proximal border (distance x), and distance from center of footprint to Blumensaat's line (distance y). The data of included studies were combined to calculate theoretical centers and standard area for both ACL as a whole bundle and as anteromedial (AM) and posterolateral (PL) bundles individually. Finally, we translated the combined data to arthroscopic localization and postsurgical evaluation.

RESULTS

A total of 13 studies were included. The theoretical centers of ACL as a whole bundle is 28.4% ± 5.1% (x) of distance t and 35.7% ± 6.9% (y) of distance h, whereas AM bundle is 24.2% ± 4%, 21.6% ± 5.2% (x, y) and PL bundle is 32.8% ± 4.7%, 46.7% ± 4.9% (x, y), respectively. The standard area of ACL footprint is a circle with a center of 27.53%, 35.85% (x, y), and a radius of 4.58%, 9.2% (x, y), respectively. Translation of combined data shows that under arthroscopy, for single-bundle ACL reconstruction, the midpoint of distance from border of proximal to distal articular cartilage is the center of anatomic femoral socket.

CONCLUSIONS

Combined data unravel the standard position of ACL femoral origin. It can be used by clinicians to localize anatomic tunnel both in surgery and postsurgical evaluation. For single-bundle ACL reconstruction, the midpoint of lateral femoral condyle corresponds to anatomic socket.

LEVEL OF EVIDENCE

Level V, systematic review of anatomic studies.

SP6616 as a new Kv2.1 channel inhibitor efficiently promotes β-cell survival involving both PKC/Erk1/2 and CaM/PI3K/Akt signaling pathways

Kv2.1 as a voltage-gated potassium (Kv) channel subunit has a pivotal role in the regulation of glucose-stimulated insulin secretion (GSIS) and pancreatic β-cell apoptosis, and is believed to be a promising target for anti-diabetic drug discovery, although the mechanism underlying the Kv2.1-mediated β-cell apoptosis is obscure. Here, the small molecular compound, ethyl 5-(3-ethoxy-4-methoxyphenyl)-2-(4-hydroxy-3-methoxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate (SP6616) was discovered to be a new Kv2.1 inhibitor. It was effective in both promoting GSIS and protecting β cells from apoptosis. Evaluation of SP6616 on either high-fat diet combined with streptozocin-induced type 2 diabetic mice or db/db mice further verified its efficacy in the amelioration of β-cell dysfunction and glucose homeostasis. SP6616 treatment efficiently increased serum insulin level, restored β-cell mass, decreased fasting blood glucose and glycated hemoglobin levels, and improved oral glucose tolerance. Mechanism study indicated that the promotion of SP6616 on β-cell survival was tightly linked to its regulation against both protein kinases C (PKC)/extracellular-regulated protein kinases 1/2 (Erk1/2) and calmodulin(CaM)/phosphatidylinositol 3-kinase(PI3K)/serine/threonine-specific protein kinase (Akt) signaling pathways. To our knowledge, this may be the first report on the underlying pathway responsible for the Kv2.1-mediated β-cell protection. In addition, our study has also highlighted the potential of SP6616 in the treatment of type 2 diabetes.

Multilayer photo-aligned thin-film structure for polarizing photonics

In this Letter, an advanced multilayer photo-aligned liquid crystal polymer (LCP) thin-film structure with multiple optical functions is introduced. Within each LCP layer, a spatially distribution of local optical axes can be controlled by a patterned photo-alignment layer. As an embodiment of the proposed structure, a two-layer structure with pixelated controlled light-propagation directions and polarizations has been studied, which has shown the potential to be used as a photomask for generating multi-domain photo-alignment structures with a single exposure step. The combination of the multilayer structure with patterned photo-alignment technology provides a new perspective of designing optical structures for polarizing photonics applications.

A point mutation of zebrafish c-cbl gene in the ring finger domain produces a phenotype mimicking human myeloproliferative disease

Controlled self-renewal and differentiation of hematopoietic stem/progenitor cells (HSPCs) are critical for vertebrate development and survival. These processes are tightly regulated by the transcription factors, signaling molecules and epigenetic factors. Impaired regulations of their function could result in hematological malignancies. Using a large-scale zebrafish N-ethyl-N-nitrosourea mutagenesis screening, we identified a line named LDD731, which presented significantly increased HSPCs in hematopoietic organs. Further analysis revealed that the cells of erythroid/myeloid lineages in definitive hematopoiesis were increased while the primitive hematopoiesis was not affected. The homozygous mutation was lethal with a median survival time around 14-15 days post fertilization. The causal mutation was located by positional cloning in the c-cbl gene, the human ortholog of which, c-CBL, is found frequently mutated in myeloproliferative neoplasms (MPN) or acute leukemia. Sequence analysis showed the mutation in LDD731 caused a histidine-to-tyrosine substitution of the amino acid codon 382 within the RING finger domain of c-Cbl. Moreover, the myeloproliferative phenotype in zebrafish seemed dependent on the Flt3 (fms-like tyrosine kinase 3) signaling, consistent with that observed in both mice and humans. Our study may shed new light on the pathogenesis of MPN and provide a useful in vivo vertebrate model of this syndrome for screening drugs.

Ammonium increases Ca(2+) signalling and upregulates expression of Cav1.2 gene in astrocytes in primary cultures and in the in vivo brain

AIM

The primary aim of this study was to identify the effects of hyperammonaemia on functional expression of Cav1.2 L-type Ca(2+) channels in astroglia.

METHODS

Primary cultures of mouse astrocytes were used to study effects of chronic treatment (1-5 days) with ammonium chloride, at 1, 3 and 5 mm on depolarization-induced increases in free cytosolic Ca(2+) concentration ([Ca(2+)]i , measured with Fura-2 based microfluorimetry) in control conditions and following treatment with the L-type Ca(2+) channel inhibitor, nifedipine, or with ryanodine receptor inhibitor, ryanodine. Expression of Cav1.2 mRNA was identified with RT-PCR, whereas protein content was determined by Western blotting. Sustained hyperammonaemia in vivo was induced by daily injections of urease (33 units kg body weight(-1), i.p.) for 3 days.

RESULTS

Depolarization-induced [Ca(2+)]i transients sensitive to nifedipine (peak of the response) and to ryanodine (plateau phase) were significantly increased in astrocytes chronically exposed to ammonium. The ammonium-induced increase in Ca(2+) influx in astrocytes resulted from an upregulation of Cav1.2 channel's expression detected at mRNA and protein levels. Increase in Cav1.2 expression was prevented by ouabain antagonist canrenone. Similar upregulation of Cav1.2 gene expression was found in the brains of adult mice subjected to intraperitoneal injection of urease. In transgenic mice tagged with an astrocyte-specific or neurone-specific markers and treated with intraperitoneal injections of urease, the fluorescence-activated cell sorting of neurones and astrocytes demonstrated that Cav1.2 mRNA expression was upregulated in astrocytes, but not in neurones.

CONCLUSIONS

Ammonium-induced deregulation of astroglial Ca(2+) signalling, is, in part, associated with upregulation of Cav1.2 L-type calcium channels.

Nontraditional risk factors for cardiovascular disease and visceral adiposity index among different body size phenotypes

BACKGROUND AND AIMS

Increased cardiovascular disease and mortality risk in metabolically healthy obese (MHO) individuals remain highly controversial. Several studies suggested risk while others do not. The traditional cardiovascular risk factors may be insufficient to demonstrate the complete range of metabolic abnormalities in MHO individuals. Hence, we aimed to compare the prevalence of elevated lipoprotein (a), apolipoprotein B, and uric acid (UA) levels, apolipoprotein B/apolipoprotein A1 ratio, and visceral adiposity index (VAI) scores, and low apolipoprotein A1 levels among 6 body size phenotypes (normal weight with and without metabolic abnormalities, overweight with and without metabolic abnormalities, and obese with or without metabolic abnormalities).

METHODS AND RESULTS

We conducted a cross-sectional analysis of 7765 Chinese adults using data from the nationwide China Health and Nutrition Survey 2009. MHO persons had intermediate prevalence of elevated apolipoprotein B and UA levels, apolipoprotein B/apolipoprotein A1 ratio and VAI scores, and low apolipoprotein A1 levels between metabolically healthy normal-weight (MHNW) and metabolically abnormal obese individuals (P < 0.001 for all comparisons). Elevated apolipoprotein B and UA concentrations, apolipoprotein B/apolipoprotein A1 ratio, and VAI scores were all strongly associated with the MHO phenotype (all P < 0.01).

CONCLUSIONS

Prevalence of elevated apolipoprotein B and UA levels, apolipoprotein B/apolipoprotein A1 ratio and VAI scores, and low levels of apolipoprotein A1 was higher among MHO persons than among MHNW individuals. The elevated levels of the nontraditional risk factors and VAI scores in MHO persons could contribute to the increased cardiovascular disease risk observed in long-term studies.

Relationship between deep venous thrombosis and inflammatory cytokines in postoperative patients with malignant abdominal tumors

Deep venous thrombosis (DVT) is a common surgical complication in cancer patients and evidence that inflammation plays a role in the occurrence of DVT is increasing. We studied a population of cancer patients with abdominal malignancies with the aim of investigating whether the levels of circulating inflammatory cytokines were associated with postoperative DVT, and to determine the levels in DVT diagnoses. The serum levels of C-reactive protein (CRP), interleukins (IL)-6 and IL-10, nuclear transcription factor-κB (NF-κB) and E-selectin (E-Sel) were determined in 120 individuals, who were divided into 3 groups: healthy controls, patients with and patients without DVT after surgery for an abdominal malignancy. Data were analyzed by ANOVA, Dunnet's T3 test, chi-square test, and univariate and multivariate logistic regression as needed. The CRP, IL-6, NF-κB, and E-Sel levels in patients with DVT were significantly higher than those in the other groups (P<0.05). The IL-10 level was higher in patients with DVT than in controls but lower than in patients without DVT. Univariate analysis revealed that CRP, IL-6, NF-κB, and E-Sel were statistically associated with the risk of DVT (OR=1.98, P=0.002; OR=1.17, P=0.000; OR=1.03, P=0.042; and OR=1.38, P=0.003; respectively), whereas IL-10 had a protective effect (OR=0.94, P=0.011). Multivariate analysis showed that E-Sel was an independent risk factor (OR=1.41, P=0.000). Thus, this study indicated that an increased serum level of E-Sel was associated with increased DVT risk in postoperative patients with abdominal malignancy, indicating that E-Sel may be a useful predictor of diagnosis of DVT.

Liquid crystal Fresnel zone lens based on single-side-patterned photoalignment layer

In this article, we disclose a method to fabricate a liquid crystal (LC) Fresnel zone lens (FZL) with high efficiency. The LCFZL, based on patterned planar-aligned regions, has been prepared by means of a two-step photoalignment technique. The proposed binary-phase LCFZL manifests 39% diffraction efficiency at the focal point, which is close to the theoretical limit, 41%. Moreover, because of a lower driving voltage and faster response time, these elements could find application in many modern devices.

Regulation of epidermal growth factor receptor signaling by plasmid-based microRNA-7 inhibits human malignant gliomas growth and metastasis in vivo

MicroRNAs are endogenous, non-coding RNAs of approximately 20-22 nucleotides that regulate genes expression by binding to the 3' untranslated region (UTR) of targets mRNAs and play critical roles in cancer pathways. Malignant glioma is the most common and highly lethal central nervous system tumor for which little effective treatment is available over several decades. The purpose of this study was to explore the therapeutic potential of plasmid-based microRNA-7 (miR-7) for gliomas in vivo. Enhancing miR-7 levels in vitro could significantly induce cell apoptosis, and inhibit cell proliferation, cell migration and invasion. Western blotting analysis was performed, which indicated that miR-7 directly inhibited epidermal growth factor receptor (EGFR) and further antagonized the downstream protein kinases including ERK, Akt and Stat3. Furthermore, systemic administration of miR-7 encapsulated in cationic liposome resulted in glioma xenografts growth arrest and the metastatic nodules decrease effectively in a sequence-specific manner. In this study, miR-7 was applied in glioma treatment for the first time in vivo. Our findings suggested that the plasmid-mediated gene therapy with miR-7 appeared to be a promising candidate for the development of new antitumor and anti-metastasis treatment for human glioma.

SKLB1002, a novel inhibitor of VEGF receptor 2 signaling, induces vascular normalization to improve systemically administered chemotherapy efficacy

Vascular endothelial growth factor receptor (VEGFR) or vascular endothelial growth factor (VEGF) inhibitors have shown only modest clinical activity for most tumor types when used as single agents. However, present evidence indicates that these antiangiogenic drugs can cause transient "normalization" of the tumor vasculature, thereby improving the delivery of systemic chemotherapy. We examined temporal changes in tumor vascular function in response to the novel VEGFR2 inhibitor, SKLB1002. Established tumor-bearing animals were evaluated at serial time points for treatment-associated changes in tumor vascular architecture and function. As a result, blocking VEGF signaling by SKLB1002 produced a morphologically and functionally "normalized" vascular network. Consistent with our observations, a 2.2 fold increase in intratumoral doxorubicin levels was determined with SKLB1002 pretreatment compared with administration of doxorubicin alone. Finally, combined SKLB1002 and doxorubicin exhibited significant antitumor (49% of control size) and antimetastatic effects (12% of control metastatic nodules) in vivo. Our results showed SKLB1002 induced vascular normalization and enhanced anticancer drug delivery, which were associated with the observed synergistic effect in vivo.

Inhibition of hepatitis B virus gene expression by small interfering RNAs targeting cccDNA and X antigen

To test the possible inhibition of hepatitis B virus (HBV) replication and expression by small interfering RNAs (siRNAs) targeting simultaneously covalenthy closed circular DNA (dnacccDNA) and X antigen, corresponding recombinant plasmids were transfected into HepG2.2.15 cells and the levels of cccDNA, HBXAg, HBcAg, and HBeAg were assayed at various times post transfection. As expected, the single siRNAs showed marked inhibitory effects but their combination was even more efficient. These results provide a new insight into the development of a potential anti-HBV strategy of enhancing the efficacy of individual antivirals and overcoming the high mutation rate of HBV.

Susceptibility of meat starter cultures to antimicrobials used in food animals in Canada

Lactic acid bacteria (LAB) are extensively used in the food industry for fermentation processes. However, it is possible that these bacteria may serve as a reservoir for antibiotic resistance genes that can be transferred to pathogens, giving rise to public health concerns. Animal operations that use antimicrobials as growth promotants have been linked to the origin of resistance due to the selective effect of low levels of antimicrobial used in this management strategy. The objective of this study was to determine the antimicrobial susceptibilities and mechanisms of resistance for 30 isolates of meat starter cultures commonly used in dry sausage fermentations to 20 antimicrobial agents. Susceptibility tests were performed by broth microdilution using Iso-Sensitest broth (90%, vol/vol) and de Man Rogosa Sharpe (MRS) broth (10%, vol/vol). The results showed that all 30 isolates exhibited resistance to at least three antimicrobials regardless of antimicrobial class while 17 or 30% of strains were resistant to antibiotics in three or six different classes, respectively. The incidence of antimicrobial resistance was higher among Pediococcus pentosaceus and lower for Staphylococcus carnosus strains. Genetic determinants for the lincosamide, macrolide, and tetracycline antimicrobials were not found using PCR. Phenotypic resistance in the absence of known resistance genes found here suggests that other mechanisms or genes might have contributed to the negative results. Further studies are needed to explore the genetic mechanisms underlying the prevalence of antibiotic resistance in Pediococcus species.

Paroxysmal kinesigenic choreoathetosis: evidence of linkage to the pericentromeric region of chromosome 16 in four Chinese families

BACKGROUND

Paroxysmal kinesigenic choreoathetosis (PKC) is an autosomal dominant condition characterized by abnormal involuntary movements precipitated by sudden movement. The pericentromeric region of chromosome 16 has been linked to PKC by several reports. This study was to localize and identify PKC gene in four Chinese PKC families.

METHODS

Genetic linkage mapping with eight markers spanning chromosome 16p12-q13 was performed in 43 family members. Genome-wide single nucleotide polymorphism (SNP) scans were performed on four individuals in Family 1 in which infantile convulsion (IC) was co-inherited with PKC.

RESULTS

Individuals in Family 1 presented with both IC and paroxysmal choreoathetosis (ICCA), and Families 2, 3, and 4 presented only with PKC. Evidence for linkage was found with a maximum two-point LOD score of 4.89 for D16S690 (theta = 0.0) and a maximum multipoint LOD score was 5.34 between D16S3080 and D16S3136. Haplotype analysis showed the disease locus was between D16S3093 and D16S3057. A total of 84 SNPs spanned on 16q12.1-q13 was not segregated with the PKC phenotype, which defined an unlinked region from rs9933187 to rs8044753. Thus, the critical region of the PKC gene is across the pericentromeric region of chromosome 16, and most likely maps to a region of 20.5 Mb (6.2 cM) between D16S3093 and rs9933187 (16p11.2-q12.1).

CONCLUSION

The assignment of the locus for PKC to the pericentromeric region of chromosome 16 is confirmed and putatively narrowed in the present study.