Five alternative splicing variants of the TYR gene and their different roles in melanogenesis in the Muchuan black-boned chicken

1. The TYR gene encodes tyrosinase, a multifunctional enzyme that is essential for melanin biosynthesis in melanocytes. This experiment involved the cloning and characterisation of the TYR gene in chicken. Five alternative splice variants were identified in the black feather bulb and designated as TYR-AS1, TYR-AS2, TYR-AS3, TYR-AS4 and TYR-AS5. 2. Among the 11 chicken tissues examined, the feather bulb, comb and skin showed higher levels of all TYR variants. All TYR variants were expressed at significantly different levels in black and white feather bulbs (P < 0.05) and may be involved in melanin formation in plumage. Only TYR-AS1, which plays an important role in muscle melanogenesis, was significantly differentially expressed between black and white muscle (P < 0.01). All TYR variants were expressed at significantly different levels in black and white skin (P < 0.01). 3. The mRNA expression levels of the 5 variants were closely associated with skin melanogenesis in the chicken. These findings provide new clues to the molecular mechanism of melanin formation in the Muchuan black-boned chicken.

Depth of field extension and objective space depth measurement based on wavefront imaging

When all the parts of the wavefront imaging system are kept static after wavefront measuring, the target's images are blurry, because the depth of field (DOF) of the system affects the imaging quality. In this paper, the method for extending the DOF of the wavefront imaging system through an integrated architecture of a liquid-crystal microlens array (LCMLA) powered by electricity and a common photosensitive array, is presented. The DOF can be extended remarkably only by stitching together several sub-images of the LCMLA. The problem that the wavefronts and imaging results are insensitive to the objective depth is also solved. Optimal driving voltage signals are found out according to Sobel mean gradient to efficiently calibrate the depth of objective space in order to quantitatively measure the depth. The approach indicates a viable way to effectively extend the DOF of imaging micro-systems and to measure the geometrical depth of targets at the same time.

An OLTAM system for analysis of brown/beige fat thermogenic activity

BACKGROUND/OBJECTIVES

Thermogenic fat is present in humans and emerging evidence indicates that increasing the content and activity of these adipocytes may lead to weight loss and improved metabolic health. Multiple reporter systems have been developed to assay thermogenic fat activity based on the transcriptional and translational activation of Ucp1, the key molecule that mediates nonshivering thermogenesis. Our study aims to develop a much-needed tool to monitor thermogenic fat activity through a mechanism independent of Ucp1 regulation, therefore effectively assaying not only canonical β-adrenergic activation but also various non-UCP1-mediated thermogenic pathways that have been increasingly appreciated.

METHODS

We detected increased luciferase activity upon thermogenic activation in interscapular brown and inguinal subcutaneous fat in ODD-Luc mice, a hypoxia reporter mouse model. We then developed an OLTAM (ODD-Luc based Thermogenic Activity Measurement) system to assay thermogenic fat cell activity.

RESULTS

In both primary murine and human adipocytes and an immortalized adipose cell line that were transduced with the OLTAM system, luciferase activity can be readily measured and visualized by bioluminescence imaging in response to a variety of stimuli, including UCP1-independent thermogenic signaling. This system can offer a convenient method to assay thermogenic activity for both basic and translational research.

CONCLUSIONS

The OLTAM system offers a convenient way to measure of the activation of thermogenic fat and presents opportunities to discover novel signaling pathways and unknown compounds targeting metabolically active adipocytes to counteract human obesity.

Efficacy and safety of three adefovir-based combination therapies in HBeAg-positive chronic hepatitis B patients with suboptimal response to adefovir monotherapy

Although high potent nucleos(t)ide analogues are strongly recommended as first-line therapy for chronic hepatitis B (CHB) in China, some patients are still being treated with adefovir disoproxil (ADV), especially those low-income patients whose health insurance could not reimburse the drug cost. Therefore, the management of patients who have failed ADV therapy or who sustained renal damage during ADV therapy remains an important clinical problem in China. This retrospective study aimed to compare the efficacy and safety of lamivudine (LAM), telbivudine (LdT) or entecavir (ETV) add-on strategies to optimize the treatment of patients with prior suboptimal response to ADV monotherapy. A total of 277 eligible patients were included in this study, and the baseline characteristics were similar among the LAM + ADV (n = 116), LdT + ADV (n = 72) and ETV + ADV (n = 89) groups. At week 96, both the proportion of undetectable HBV DNA (81.03% for LAM + ADV, 84.72% for LdT + ADV and 88.76% for ETV + ADV; P = .317) and ALT elevation (5.17% for LAM + ADV, 4.17% for LdT + ADV and 4.49% for ETV + ADV; P = 1.000) were similar among the three groups; also, a significant decline in liver stiffness was observed in each group from baseline to week 96. At week 96, the rate of HBeAg seroconversion was significantly higher in LdT + ADV than in LAM + ADV (26.39% vs 13.79%, P = .031) and ETV + ADV (26.39% vs 10.11%, P = .007). During the 96 weeks, no obvious renal injury was reported in any of the three groups, but an improvement in eGFR was found in LdT + ADV compared with LAM + ADV and ETV + ADV. In summary, all three combination strategies provide good control of virus replication, but the LdT + ADV combination therapy may yield better HBeAg seroconversion and eGFR improvement.

Genetic variation in the MITF promoter affects skin colour and transcriptional activity in black-boned chickens

1. Microphthalmia-associated transcription factor (MITF) plays a pivotal role in melanocyte development by regulating the transcription of major pigmentation enzymes (e.g. TYR, TYRP1 and DCT). A single-nucleotide polymorphism (SNP), c.-638T>C, was identified in the MITF promoter, and genotyping of a population (n = 426) revealed that SNP c.-638T>C was associated with skin colour in black-boned chickens. 2. Individuals with genotypes CC and TC exhibited greater MTIF expression than those with genotype TT. Luciferase assays also revealed that genotype CC and TC promoters had higher activity levels than genotype TT. Expression of melanogenesis-related gene (TYR) was higher in the skin of chickens with the CC and CT genotype compared to TT chickens (P < 0.05). 3. Transcription factor-binding site analyses showed that the c.-638C allele contains a putative binding site for transcription factor sterol regulatory element-binding transcription factor 2, aryl hydrocarbon receptor nuclear translocator, transcription factor binding to IGHM enhancer 3 and upstream transcription factor 2. In contrast, the c.-638T allele contains binding sites for Sp3 transcription factor and Krüppel-like factor 1. 4. It was concluded that MITF promoter polymorphisms affected chicken skin colour. SNP c.-638T>C could be used for the marker-assisted selection of skin colour in black-boned chicken breeding.

Characterization of retroviral infectivity and superinfection resistance during retrovirus-mediated transduction of mammalian cells

Retroviral vectors including lentiviral vectors are commonly used tools to stably express transgenes or RNA molecules in mammalian cells. Their utilities are roughly divided into two categories, stable overexpression of transgenes and RNA molecules, which requires maximal transduction efficiency, or functional selection with retrovirus (RV)-based libraries, which takes advantage of retroviral superinfection resistance. However, the dynamic features of RV-mediated transduction are not well characterized. Here, we engineered two murine stem cell virus-based retroviral vectors expressing dual fluorescence proteins and antibiotic markers, and analyzed virion production efficiency and virion stability, dynamic infectivity and superinfection resistance in different cell types, and strategies to improve transduction efficiency. We found that the highest virion production occurred between 60 and 72 h after transfection. The stability of the collected virion supernatant decreased by >60% after 3 days in storage. We found that RV infectivity varied drastically in the tested human cancer lines, while low transduction efficiency was partially overcome with increased virus titer, prolonged infection duration and/or repeated infections. Furthermore, we demonstrated that RV receptors PIT1 and PIT2 were lowly expressed in the analyzed cells, and that PIT1 and/or PIT2 overexpression significantly improved transduction efficiency in certain cell lines. Thus, our findings provide resourceful information for the optimal conditions of retroviral-mediated gene delivery.

First Direct-Detection Constraints on eV-Scale Hidden-Photon Dark Matter with DAMIC at SNOLAB

We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30  eV c^{-2} with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter κ is competitive with constraints from solar emission, reaching a minimum value of 2.2×10^{-14} at 17  eV c^{-2}. These results are the most stringent direct detection constraints on hidden-photon dark matter in the galactic halo with masses 3-12  eV c^{-2} and the first demonstration of direct experimental sensitivity to ionization signals <12  eV from dark matter interactions.

The efficacy and safety of intensified enteric-coated mycophenolate sodium with low exposure of calcineurin inhibitors in Chinese de novo kidney transplant recipients: a prospective study

AIMS

The aim of this study was to investigate the efficacy and safety of a transient intensified enteric-coated mycophenolate sodium (EC-MPS) dosing regimen with low exposure of calcineurin inhibitors (CNIs) in Chinese de novo kidney transplantation.

METHODS

In a 6-month prospective study, a total of 97 recipients were enrolled and assigned to either an intensified EC-MPS dosing (IS) regimen or a standard EC-MPS dosing (SD) regimen. The area under the curve (AUC) of MPA was assessed at week 1 post transplant. The incidences of acute rejection, patient and graft survival, renal allograft function and adverse events were analysed.

RESULTS

The IS regimen displayed a trend of acute rejection risk reduction (IS 2.7% vs. SD 13.3%, p = 0.061) and allograft function improvement (IS 62.8 ± 14.0 ml/min per 1.73 m(2) vs. SD 56.6 ± 18.3 ml/min per 1.73 m(2) , p = 0.084) after 6-month follow-up. MPA-AUC0-12 h was substantially higher in the intensified EC-MPS group than the standard EC-MPS group, though without a significant difference (71.4 ± 41.7 vs. 53.0 ± 27.0 mg·h/l, p = 0.107). The IS regimen did not increase the incidence of adverse effects (IS 54.1% vs. 45.0%, p = 0.39), including diarrhoea or leucopenia.

CONCLUSIONS

The intensified EC-MPS dosing regimen maintaining low-dose CNIs in this study may be beneficial for Chinese adult de novo kidney transplant recipients in terms of acute rejection and allograft function and is safe within 6 months post transplant.

eEF-2 kinase is a critical regulator of Warburg effect through controlling PP2A-A synthesis

Cancer cells predominantly metabolize glucose by glycolysis to produce energy in order to meet their metabolic requirement, a phenomenon known as Warburg effect. Although Warburg effect is considered a peculiarity critical for survival and proliferation of cancer cells, the regulatory mechanisms behind this phenomenon remain incompletely understood. We report here that eukaryotic elongation factor-2 kinase (eEF-2K), a negative regulator of protein synthesis, has a critical role in promoting glycolysis in cancer cells. We showed that deficiency in eEF-2K significantly reduced the uptake of glucose and decreased the productions of lactate and adenosine triphosphate in tumor cells and in the Ras-transformed mouse embryonic fibroblasts. We further demonstrated that the promotive effect of eEF-2K on glycolysis resulted from the kinase-mediated restriction of synthesis of the protein phosphatase 2A-A (PP2A-A), a key factor that facilitates the ubiquitin-proteasomal degradation of c-Myc protein, as knockdown of eEF-2K expression led to a significant increase in PP2A-A protein synthesis and remarkable downregulation of c-Myc and pyruvate kinase M2 isoform, the key glycolytic enzyme transcriptionally activated by c-Myc. In addition, depletion of eEF-2K reduced the ability of the transformed cells to proliferate and enhanced the sensitivity of tumor cells to chemotherapy both in vitro and in vivo. These results, which uncover a role of the eEF-2K-mediated control of PP2A-A in tumor cell glycolysis, provide new insights into the regulation of the Warburg effect.

Recipient C6 rs9200 genotype is associated with hepatocellular carcinoma recurrence after orthotopic liver transplantation in a Han Chinese population

Hepatocellular carcinoma (HCC) recurrence is one of the leading causes of death after orthotopic liver transplantation (OLT). The sixth complement component (C6) is a late-acting complement protein that participates in the assembly of the membrane attack complex, which has an indispensable role in innate and acquired immune responses, as well as cancer immune surveillance. However, studies assessing the association between C6 and HCC recurrence after OLT are scarce. This study aimed to evaluate the association of donor and recipient C6 single-nucleotide polymorphisms with the risk for HCC recurrence after OLT. A total of 71 adult patients who underwent primary LT for HCC were enrolled. HCC recurrence was observed in 26 (36.6%) patients. Ten single-nucleotide polymorphisms were genotyped and analyzed in both donor and recipient groups. Patients with the rs9200 heterozygous GA variant presented significantly higher HCC recurrence rates (54.17 vs 27.66%, P=0.028), and lower cumulative tumor-free survival and overall survival (P=0.006 and P=0.013, respectively) compared with those harboring the GG/AA genotype, in multivariate logistic regression and Cox regression analyses. The rs9200 heterozygous GA variant in C6 persisted as a statistically independent prognostic factor (P<0.05) for predicting HCC recurrence after OLT. In conclusion, recipient C6 rs9200 polymorphism is associated with HCC recurrence after OLT, and improves the predictive value of clinical models.

Abstract P2-11-03: Phase I/II randomized study of combination immunotherapy with or without polysaccharide krestin (PSK) concurrently with a HER2 ICD peptide-based vaccine in patients with stage IV breast cancer receiving HER2-targeted monoclonal antibody therapy

Natural killer (NK) cell defects, commonly seen in metastatic breast cancer (MBC) lead to decrease in dendritic cell (DC) maturation, proinflammatory cytokine production, and tumor infiltrating T-cells (TILs). This results in a protumorigenic Th2 immune microenvironment with low response rates to immunotherapy (i.e., immune checkpoint blockade) and standard chemotherapy. PSK, a potent TLR-2 agonist, activates NK cells to produce IFN-γ and IL-12 and promote DC maturation/differentiation toward a Th1 profile in the tumor microenvironment which results in antigen specific TIL that can eradicate tumor. The combination immunotherapy of PSK and HER2 directed therapy described here, aims at inducing Th1 immunity and tumor specific T-cells. This proposed regimen could eradicate microscopic residual disease and prevent recurrence in optimally treated HER2+ MBC patients. Moreover, the regimen could result in enhanced trafficking of TILs to the site of tumor and improve the efficacy of checkpoint inhibitors and other therapies. A phase I/II randomized 2 arm study of combination immunotherapy with oral PSK (or placebo) given with a HER2 peptide vaccine and HER2 mAb therapy (trastuzumab (TZ) +/- pertuzumab (PZ)) was initiated to assess the safety of the approach and evaluate the effect of PSK on NK cell activity, pro-inflammatory cytokine/chemokine profile; and HER2 vaccine-induced T cell immunity.

Methods: Up to 30 patients with HER2+ MBC who are without evidence of disease after definitive therapy and currently on maintenance TZ +/- PZ are enrolled and randomly assigned in equal numbers to 1 of 2 arms (15 patients/arm): Arm 1: HER2 ICD vaccine + placebo or Arm 2: HER2 ICD vaccine + PSK. All patients receive concomitant treatment with 4 months of daily oral PSK or placebo, 3 monthly intradermal HER2 ICD vaccinations and continued TZ +/- PZ. Toxicity is evaluated per CTEP CTCAE 4.0, during and post vaccination. Serial blood draws for immunologic evaluation of NK cell activity and antigen-specific T cell immunity via flow cytometry and IFN-γ ELISPOT, respectively; and pro-inflammatory cytokines/chemokines.

Results: 24 subjects have been enrolled and 60 vaccines have been given. 16 subjects have completed all 3 vaccines and PSK/placebo; and 6 subjects are currently in progress. 2 subjects received &lt; 3 vaccines and were taken off study. Of 144 reported adverse events (AEs), 97% were Grade 1-2; 66 (46%) were possibly, probably, or definitely related to study treatment. Most common AEs are injection site reaction and flu-like symptoms. There have been a total of four Grade 3 AEs, 1 episode of self-limited nausea/vomiting attributed to study treatment; and cognitive disturbance, fatigue, and lymphopenia all in 1 subject and attributed to disease progression. There have been no Grade 4 AEs. Immunologic analyses are ongoing and will be presented along with completed clinical data on all patients.

Conclusion: Combination immunotherapy with PSK/placebo and concurrent HER2 directed therapy is safe and well-tolerated. Further ongoing immunologic studies will help define the immunogenicity of the approach.

Citation Format: Salazar LG, Higgins D, Childs J, Coveler AL, Liao J, Stanton S, Gooley T, Standish LJ, Sasagawa M, DISIS ML. Phase I/II randomized study of combination immunotherapy with or without polysaccharide krestin (PSK) concurrently with a HER2 ICD peptide-based vaccine in patients with stage IV breast cancer receiving HER2-targeted monoclonal antibody therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-03.