Aβ1-42 increases the expression of neural KATP subunits Kir6.2/SUR1 via the NF-κB, p38 MAPK and PKC signal pathways in rat primary cholinergic neurons

ATP-sensitive potassium channels (KATP) may mediate a potential neuroprotective role in Alzheimer's disease (AD). Given that exposure to Aβ1-42 in cultured primary cholinergic neurons for 72 h significantly upregulates the expression of KATP subunits Kir6.2/SUR1, we aim to study the underlying signal transduction mechanisms that are involved in Aβ_1-42-induced upregulation of KATP subunits Kir6.2/SUR1. In the present study, we first identified the primary cultured rat cortical and hippocampal neurons using immunocytochemistry. 0.5 μM NF-κB inhibitor SN-50, 2 μM p38MAPK inhibitor SB203580 or 2 μM PKC inhibitor Chelerythrine chloride (CTC) were then added in three separate groups, followed by 2 μM Aβ_1-42 30 min later in all 3 groups. Western Blot was performed 72 h later to detect the expression of KATP subunits Kir6.2/SUR1. We found that Aβ_1-42 significantly increased the level of KATP subunits Kir6.2/SUR1 expression at 72 h when compared with the control group ( p < 0.05). However, when compared with the Aβ_1-42 group, the level of KATP subunits Kir6.2/SUR1 expression at 72 h significantly decreased in the SN50 + Aβ_1-42 group, SB203580 + Aβ_1-42 group, and the CTC + Aβ_1-42 group ( p < 0.05). Our findings suggest that the NF-κB, p38 MAPK, and PKC signal pathways are partially involved in the upregulation of KATP subunits Kir6.2/SUR1 expression induced by Aβ_1-42 cytotoxicity in neurons, which supports a potential theoretical basis of targeting these signal pathways in the treatment of AD.

Acanthopanacis Cortex extract: A novel photosensitizer for head and neck squamous cell carcinoma therapy

OBJECTIVES

The aim of this study was to develop a novel photosensitizer from traditional plant extracts and to investigate the photodynamic therapy (PDT) effect and mechanism of action of the novel photosensitizer on KB and Hep-2 cells.

METHODS

Fluorescence emission, cell viability, and intracellular distribution of candidates were analyzed to screen potential photosensitizers from traditional plant extracts. Cellular reactive oxygen species (ROS) quantification, Annexin V-FITC/PI staining, and western blotting were performed to explore the mechanism of cell death in KB and Hep-2 cells.

RESULT

Of 289 traditional plant extracts, 13 plant extracts with strong fluorescence were initially screened by fluorescence emission analysis. The cell viability assay and intracellular distribution of candidates showed that Acanthopanacis Cortex (AC) extract is a potential photosensitizer. Under optimal PDT conditions, high levels of ROS were produced in KB and Hep-2 cells, followed by cell death. However, there was no significant damage to HaCaT cells. Moreover, apoptosis induced by AC extract with 625 nm irradiation (IR) down-regulated the expression of Bcl-2 protein and up-regulated the expression of Bax protein, as well as that of cleaved PARP-1 protein in both KB and Hep-2 cells.

CONCLUSION

The fluorescence intensity of AC extract at 420 nm is similar to that of the commercial Hematoporphyrin (HP). AC extract with 625 nm IR could enhance the PDT effect, induce ROS generation, and trigger apoptotic pathways in KB and Hep-2 cells. Therefore, we suggest that AC is a potential novel photosensitizer for PDT in head and neck squamous cell carcinoma.

Microwave ablation combined with doxorubicin enhances cell death via promoting reactive oxygen species generation in breast cancer cells

PURPOSE

To evaluate the mechanism for enhancing cell death induced by microwave ablation (MWA) combined with doxorubicin treatment in breast cancer cells.

MATERIALS AND METHODS

Different temperatures of heat treatment were used to mimic the tumor affected by sublethal heat during MWA in vitro. Breast cancer cells were treated at 43°C and 45°C, with or without doxorubicin. Cell viability, apoptosis, and intracellular reactive oxygen species (ROS) were evaluated in MDA-MB-231 and SUM-1315 cells. Nude mice breast cancer models were randomly divided into control, MWA, doxorubicin, and combined treatment groups. Tumor apoptosis and DNA damage were evaluated in these groups.

RESULTS

The combined group had lower cell viability than the heat or doxorubicin group (all P<0.05), and enhanced apoptosis rate was observed in the combined group compared to others (all P<0.01) in MDA-MB-231 and SUM-1315. Increased capase3 (all P<0.01) and decreased Bcl-Xl (all P<0.01) were detected after combined therapy compared to single treated group in vitro. The raisedCaspase3 and DNA damage marker histone H2A.X induced by combined treatment were also approved in the nude mice models. Combined treatment promoted ROS generation compared to doxorubicin or MWA treatment (all P < 0.01). NF-κB expression in the combined group was higher than that of the single treatment group (all P<0.05). N-acetylcysteine (NAC), a ROS scavenger, partly restrained the combined treatment induced cell proliferation inhibition, Caspase3 and NF-κB compared to doxorubicin treatment (all P<0.05).

CONCLUSION

MWA combined with doxorubicin promote cell death via ROS induced cell apoptosis and DNA damage. Increasing ROS has potential for improving the efficiency of combined treatment.

Fluid intake in urban China: results of the 2016 Liq.In 7 national cross-sectional surveys

Purpose

To describe total fluid intake (TFI) and types of fluid consumed in urban China by age, gender, regions and city socioeconomic status relative to the adequate intakes (AI) set by the Chinese Nutrition Society.

Methods

In 2016, participants aged 4–9, 10–17 and 18–55 years were recruited via a door-to-door approach in 27 cities in China. In total, 2233 participants were included. The volumes and sources of TFI were collected using the Liq.In⁷ record, assisted by a photographic booklet of standard fluid containers.

Results

The mean daily TFI among children, adolescents and adults were 966, 1177 and 1387 mL, respectively. In each age group, TFI was significantly higher in male vs female (981 vs 949, 1240 vs 1113, 1442 vs 1332; mL). Approximately 45, 36 and 28% of children, adolescents and adults reached the AI. Although plain water was the highest contributor to TFI, the contribution of sugar sweetened beverages (SSB) was ranked in the top three together with water and milk and derivatives. Approximately 27, 48 and 47% of children, adolescents and adults consumed more than one serving of SSB per day, respectively.

Conclusions

A relatively large proportion of participants did not drink enough to meet the AI in urban China. Many children, adolescents and adults consumed more than one serving of SSB per day. A majority of children, adolescents and adults in the study population do not meet both quantitative and qualitative fluid intake requirements, and signal socioeconomic disparities.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1755-5) contains supplementary material, which is available to authorized users.

Molecular Determinants for STIM1 Activation During Store- Operated Ca2+ Entry

BACKGROUND

STIM/ORAI-mediated store-operated Ca2+ entry (SOCE) mediates a myriad of Ca2+-dependent cellular activities in mammals. Genetic defects in STIM1/ORAI1 lead to devastating severe combined immunodeficiency; whereas gain-offunction mutations in STIM1/ORAI1 are intimately associated with tubular aggregate myopathy. At molecular level, a decrease in the Ca2+ concentrations within the lumen of endoplasmic reticulum (ER) initiates multimerization of the STIM1 luminal domain to switch on the STIM1 cytoplasmic domain to engage and gate ORAI channels, thereby leading to the ultimate Ca2+ influx from the extracellular space into the cytosol. Despite tremendous progress made in dissecting functional STIM1-ORAI1 coupling, the activation mechanism of SOCE remains to be fully characterized.

OBJECTIVE AND METHODS

Building upon a robust fluorescence resonance energy transfer assay designed to monitor STIM1 intramolecular autoinhibition, we aimed to systematically dissect the molecular determinants required for the activation and oligomerization of STIM1.

RESULTS

Here we showed that truncation of the STIM1 luminal domain predisposes STIM1 to adopt a more active conformation. Replacement of the single transmembrane (TM) domain of STIM1 by a more rigid dimerized TM domain of glycophorin A abolished STIM1 activation. But this adverse effect could be partially reversed by disrupting the TM dimerization interface. Moreover, our study revealed regions that are important for the optimal assembly of hetero-oligomers composed of full-length STIM1 with its minimal STIM1-ORAI activating region, SOAR.

CONCLUSIONS

Our study clarifies the roles of major STIM1 functional domains in maintaining a quiescent configuration of STIM1 to prevent preactivation of SOCE.

An Antimicrobial Peptide-Loaded Gelatin/Chitosan Nanofibrous Membrane Fabricated by Sequential Layer-by-Layer Electrospinning and Electrospraying Techniques

Guided bone regeneration (GBR) technique is widely used in the treatment of bone defects caused by peri-implantitis, periodontal disease, etc. However, the GBR membranes commonly used in clinical treatments currently have no antibacterial activity. Therefore, in this study, sequential layer-by-layer electrospinning and electrospraying techniques were utilized to prepare a gelatin (Gln) and chitosan (CS) composite GBR membrane containing hydroxyapatite nanoparticles (nHAp) and antimicrobial peptide (Pac-525)-loaded PLGA microspheres (AMP@PLGA-MS), which was supposed to have osteogenic and antibacterial activities. The scanning electron microscope (SEM) observation showed that the morphology of the nanofibers and microspheres could be successfully produced. The diameters of the electrospun fibers with and without nHAp were 359 ± 174 nm and 409 ± 197 nm, respectively, and the mechanical properties of the membrane were measured according to the tensile stress-strain curve. Both the involvement of nHAp and the chemical crosslinking were able to enhance their tensile strength. In vitro cell culture of rat bone marrow mesenchymal stem cells (rBMSCs) indicated that the Gln/CS composite membrane had an ideal biocompatibility with good cell adhesion, spreading, and proliferation. In addition, the Gln/CS membrane containing nHAp could promote osteogenic differentiation of rBMSCs. Furthermore, according to the in vitro drug release assay and antibacterial experiments, the composite GBR membrane containing AMP@PLGA-MS exhibited a long-term sustained release of Pac-525, which had bactericidal activity within one week and antibacterial activity for up to one month against two kinds of bacteria, S. aureus and E. coli. Our results suggest that the antimicrobial peptide-loaded Gln/CS composite membrane (AMP@PLGA-MS@Gln/CS/nHAp) has a great promise in bone generation-related applications for the unique functions of guiding bone regeneration and inhibiting bacterial infection as well.

Overexpression of UBE2C correlates with poor prognosis in gastric cancer patients

OBJECTIVE

The ubiquitin-conjugating enzyme E2C (UBE2C) has been known as a crucial factor upregulated in various tumors. The functions of UBE2C is mainly involved in the pathway protein ubiquitination. This study investigates the expression of UBE2C in gastric cancers and its correlation with overall survival rate.

MATERIALS AND METHODS

Real-time PCR (RT-PCR) and Western blotting were performed to determine the expression of UBE2C in gastric cancer samples and adjacent normal tissues. Immunohistochemical staining was used to assess the expression of UBE2C in 216 paraffin-embedded gastric cancer tissues.

RESULTS

The mRNA and relevant protein levels of UBE2C in gastric cancer tissues are significantly greater than those in the adjacent normal tissues. Also, the expression of UBE2C is found to correlate with lymphatic metastasis, serosa invasion, TNM (Malignant Tumors) staging and Lauren's classification (p<0.05). The univariate analysis shows that the overexpression of UBE2C associates with poor prognosis (p=0.001). The multivariate analysis demonstrates that expression of UBE2C, lymphatic metastasis, and TNM staging are independent prognostic indicators.

CONCLUSIONS

This study shows that overexpression of UBE2C contributes to the development of gastric cancer, and UBE2C has the potential to be exploited as a therapeutic target.

Enhanced antitumor efficacy through microwave ablation in combination with immune checkpoints blockade in breast cancer: A pre-clinical study in a murine model

PURPOSE

The purpose of this study was to investigate the therapeutic efficacy of the combination of microwave ablation (MWA) in combination with immune checkpoints blockade in the treatment of breast cancer using the 4T1 tumor-bearing mice model.

MATERIALS AND METHODS

We treated tumor-bearing mice with MWA, programmed cell death protein1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade (P+C), MWA plus PD-1 and CTLA-4 blockade (combination therapy), or no-treatment. Survival time was evaluated with the Kaplan-Meyer method comparing survival curves by log-rank test. On day 15 after MWA, five mice from the combination therapy group received tumor rechallenge with 4T1 or CT26 cells and the volumes of rechallenge tumor were calculated every 5 days. Immune cells were identified by immunohistochemistry and flow cytometry, and the concentrations of plasma interferon-γ (IFN-γ) were identified by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The combination therapy significantly prolonged tumor-bearing mice survival compared to no-treatment group, P+C group or MWA group (P<0.001, P<0.001 and P=0.01, respectively) and protected most surviving mice from 4T1 tumor rechallenge (P=0.002) but not CT26 tumor rechallenge (P=0.905). Both local and systemic CD8+ T-cell responses were induced by MWA (all P<0.05) and further augmented by subsequent administration of PD-1 and CTLA-4 blockade (all P<0.05). Plasma IFN-γ concentrations were significantly elevated in the combination therapy group compared to no-treatment group, P+C group or MWA group (P<0.001, P<0.001 and P=0.01, respectively).

CONCLUSION

MWA combined with immune checkpoints blockade could synergistically enhance antitumor efficacy with augmented specific immune responses, and the combination therapy is a promising approach to treat breast cancer.

Safety and efficacy of dual-wavelength laser (1064 + 595 nm) for treatment of non-treated port-wine stains

BACKGROUND

Patients with port-wine stain (PWS) suffer physically and psychologically because of the high incidence (0.3%-0.5%) of the disease. Pulsed-dye laser (PDL) at 595 nm is the gold standard of the treatment for PWS. Nevertheless, clinicians intend to determine whether the dual-wavelength laser (DWL; 595-nm PDL + 1064-nm Nd:YAG) is an adequate choice in the treatment of non-treated PWS. This study is the first prospective within-patient controlled research seeking to investigate the safety and efficacy of DWL for the treatment of non-treated PWS.

METHODS

A total of 61 patients with non-treated flat facial PWS, who were treated using the Cynergy laser system in our clinic, were included in this study. Each PWS lesion was divided into two adjacent test treatment sites of similar size and colour. The two sites were randomly assigned to PDL or DWL treatment in a blinded manner of participants. In each case, two sets of treatment parameters were used: (i) 595-nm PDL and (ii) 595-nm PDL + 1064-nm Nd:YAG. Both had a 10 mm spot size, an epidermal cooling system and 1-s interpulse interval between two pulses. Clinical efficacy and safety outcomes were evaluated by visual assessment 2 months after treatment.

RESULTS

Comparison by visual evaluation suggests that the responses of non-treated PWS to treatment by PDL and DWL were not significantly different. Moreover, three patients developed scarring after DWL treatment.

CONCLUSION

Compared with PDL, DWL exhibits a higher risk of potential scarring and has no advantage in efficacy of treating non-treated PWS.

Prognostic value of the cancer oncogene Kelch-like 6 in gastric cancer

Background

Kelch-like 6 (KLHL6) is a cancer oncogene previously associated with specific human cancers, such as chronic lymphocytic leukaemia. Here, the mechanisms of KLHL6 function were explored in gastric cancer (GC) cells, in an in vivo experimental tumour model, and the prognostic value of KLHL6 analysis in GC tissue evaluated in a cohort of patients with GC.

Methods

Associations between clinicopathological and survival data and KLHL6 expression in GC tissues were analysed. The effects of downregulation of KLHL6 in GC cells was investigated using proliferation, invasion, apoptosis and lymphangiogenesis assays, and analysis of tumour growth in an in vivo experimental model.

Results

KLHL6 was upregulated in 43 per cent of GC tissues compared with 5 per cent of paired non-tumour tissues from 84 patients. KLHL6 protein expression in GC tissues was much higher than that in atrophic gastritis, intestinal metaplasia and dysplasia tissues from benign gastric disease samples. KLHL6 expression was positively related to the intestinal Laurén classification in GC tissues. Downregulated expression of KLHL6 in MGC-803 GC cells reduced colony formation, proliferation, viability, migration and invasion, enhanced apoptosis and inhibited the cell cycle in the G1 phase. Downregulated expression of KLHL6 also suppressed tumour growth in mice. Furthermore, downregulated expression of KLHL6 mRNA reduced the expression of nuclear-associated antigen Ki-67, vascular endothelial growth factor C, hepatocyte growth factor and matrix metalloproteinase 2 in vitro, and KLHL6 protein in tumour tissue of mice.

Conclusion

Abnormal expression of the KLHL6 oncogene promoted GC progression in vitro and in vivo, and its expression level in tumour tissue was found to be of prognostic value.

Combined diffusion-weighted imaging and dynamic contrast-enhanced MRI for differentiating radiologically indeterminate malignant from benign orbital masses

AIM

To evaluate the performance of the combination of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for differentiating radiologically indeterminate malignant from benign orbital masses.

MATERIALS AND METHODS

Sixty-five patients with orbital masses (36 benign and 29 malignant) underwent DW and DCE MRI examinations for pre-treatment evaluation. The apparent diffusion coefficient (ADC) was derived from DW imaging data using the mono-exponential model. The volume transfer constant (K^trans), the flux rate constant between the extravascular extracellular space and the plasma (K_ep), and the extravascular extracellular volume fraction (V_e) were calculated using modified Tofts model. Differences in quantitative metrics were tested using independent-samples t test. Receiver operating characteristic (ROC) curve analyses were used to determine and compare the diagnostic ability of each significant metric.

RESULTS

The malignant group demonstrated significantly lower ADC (0.711±0.260 versus 1.187±0.389, p<0.001) and higher K_ep values (1.265±0.637 versus 0.871±0.610, p=0.008) than the benign group. Optimal diagnostic performance (area under the ROC curve [AUC], 0.941; sensitivity, 0.966; specificity, 0.917) could be achieved using combined ADC and K_ep values as the diagnostic index. The diagnostic performance of the combination of ADC and K_ep was significantly better than K_ep alone (p=0.006). Compared with ADC alone, combined ADC and K_ep values also showed higher AUC (0.941 versus 0.898), although the difference did not reach statistical significance (p=0.220).

CONCLUSION

K_ep and ADC could help to differentiate radiologically indeterminate malignant from benign orbital masses. The combination of DW and DCE MRI might improve the differentiating performance.

Fabrication of Antimicrobial Peptide-Loaded PLGA/Chitosan Composite Microspheres for Long-Acting Bacterial Resistance

An antimicrobial decapeptide, KSL-W (KKVVFWVKFK-CONH₂), which could maintain stable antimicrobial activity in saliva, has therefore been widely used to inhibit biofilm formation on teeth and prevent the growth of oral microorganisms for related infectious diseases treatment. In order to control the release of KSL-W for long-term bacterial resistance, KSL-W-loaded PLGA/chitosan composite microspheres (KSL/PLGA/CS MSs) were prepared by electrospraying and combined crosslinking-emulsion methods. Different formulations of microspheres were characterized as to surface morphology, size distribution, encapsulation efficiency, in vitro drug release, and antimicrobial activity. Antibacterial experiment demonstrated the prolonged antimicrobial and inhibitory effects of KSL/PLGA/CS MSs on oral bacteria. Moreover, the cell proliferation assay proved that the released KSL-W antibacterial dosage had no cytotoxicity to the growth of osteoblast MC3T3-E1. Thus, our study suggested that the KSL-W-loaded PLGA/CS composite microspheres may have potentially therapeutic applications as an effective drug delivery system in the treatment of oral infectious diseases such as periodontitis and periodontitis, and also within bone graft substitutes for alveolar bone augmentation.

Next Generation Driver for Attosecond and Laser-plasma Physics

The observation and manipulation of electron dynamics in matter call for attosecond light pulses, routinely available from high-order harmonic generation driven by few-femtosecond lasers. However, the energy limitation of these lasers supports only weak sources and correspondingly linear attosecond studies. Here we report on an optical parametric synthesizer designed for nonlinear attosecond optics and relativistic laser-plasma physics. This synthesizer uniquely combines ultra-relativistic focused intensities of about 10²⁰ W/cm² with a pulse duration of sub-two carrier-wave cycles. The coherent combination of two sequentially amplified and complementary spectral ranges yields sub-5-fs pulses with multi-TW peak power. The application of this source allows the generation of a broad spectral continuum at 100-eV photon energy in gases as well as high-order harmonics in relativistic plasmas. Unprecedented spatio-temporal confinement of light now permits the investigation of electric-field-driven electron phenomena in the relativistic regime and ultimately the rise of next-generation intense isolated attosecond sources.