Locally Produced IGF-1 Promotes Hypertrophy of the Ligamentum Flavum via the mTORC1 Signaling Pathway

Background/Aims: Narrowing of the lumbar spinal canal is a condition called lumbar spinal stenosis (LSS) and is a high-morbidity problem in the elderly. LSS is commonly caused by hypertrophy of the ligamentum flavum (HLF). Previous studies showed that fibrosis of the ligamentum flavum (LF) largely contributed to HLF. However, the underlying pathomechanism remains unclear. Insulin-like growth factor-1 (IGF-1) is known to have an intimate relationship with fibrosis in various tissues. Nevertheless, currently, there are few studies regarding IGF-1 in HLF. In this study, we investigated the role of IGF-1 in HLF and its potential molecular mechanism of action. Methods: First, the IGF-1, phosphorylation of IGF-1 receptor (pIGF-1R), phosphorylation of AKT (pAKT), phosphorylation of S6(pS6), collagen I and collagen III expression levels were examined via immunohistochemistry and Western blotting in LF tissues from patients with LSS or Non-LSS. Second, primary LF cells were isolated from adults with a normal LF thickness and were cultured with different concentrations of IGF-1 with or without NVP-AEW541/rapamycin. Results: The results showed that IGF-1, pIGF-1R, pAKT, pS6, collagen I and collagen III protein expression in the LSS group was significantly higher than that in the Non-LSS group. Meanwhile, pIGF-1R, pAKT, pS6, collagen I and collagen III protein expression was significantly enhanced in LF cells after IGF-1 exposure, which can be notably blocked by NVP-AEW541. In addition, pS6, collagen I and collagen III protein expression was blocked by rapamycin. Conclusions: Enhanced IGF-1 promotes the synthesis of collagen I and collagen III via the mTORC1 signaling pathway, which eventually contributes to hypertrophy of the ligamentum flavum.

Convenient synthesis of amides by Zn(ClO4)2·6H2O catalysed Ritter reaction with nitriles and halohydrocarbons

A convenient and high yielding procedure for the synthesis of amides by the Ritter reaction of nitriles and halohydrocarbons in the presence of Zn(ClO4)2·6H2O as a highly stable, effective and available catalyst is described.

A novel three‑miRNA signature predicts survival in cholangiocarcinoma based on RNA‑Seq data

Accumulating evidence illustrates that many microRNAs (miRNAs) are abnormally expressed in cholangiocarcinoma and play important roles in tumorigenesis, tumor progression and metastasis. These miRNAs may serve as prognostic biomarkers and potential therapeutic targets. The aim of the present study was to identify the differentially expressed miRNAs in cholangiocarcinoma tissues vs. normal tissues by analyzing high‑throughput data derived from The Cancer Genome Atlas (TCGA) database. Furthermore, we evaluated the prognostic performance of the differentially expressed miRNAs and developed a novel three‑miRNA signature which predicted survival in cholangiocarcinoma patients. According to the cut‑off criteria of P<0.01 and |log2FC|>1.0, a total of 100 miRNAs (54 upregulated and 46 downregulated) were found to be differentially expressed and some of them were significantly associated with clinical features. Of the above 100 miRNAs, we obtained three miRNAs (miR‑10b, miR‑22 and miR‑551b) which were markedly related to patient overall survival (OS). Subsequently, a novel three‑miRNA signature was established and validated to be effective to predict survival. The results demonstrated that the survival rate, as well as the survival time of patients were obviously enhanced in relation to a lower miRNA signature index. Univariate and multivariate Cox regression analyses revealed that the three‑miRNA signature was an independent prognostic factor in cholangiocarcinoma. The reliability of the three‑miRNA signature was validated by an independent cohort from Gene Expression Omnibus (GEO). Furthermore, the functional enrichment analysis emphasized that the target genes of the aforementioned miRNAs may be involved in a variety of pathways and processes associated with cancer. Finally, these three miRNAs were detected for verification of expression using RT‑qPCR, and miR‑551b was selected for the verification of biological functions in cholangiocarcinoma cells. The results revealed that overexpression of miR‑551b decreased cancer cell proliferation and promoted apoptosis. Collectively, the results of the present study indicated that a specific three‑miRNA signature could be considered as an alternative prognostic marker in cholangiocarcinoma.

MiR-1301-3p inhibits human breast cancer cell proliferation by regulating cell cycle progression and apoptosis through directly targeting ICT1

BACKGROUND

MiRNAs regulate a variety of biological processes, such as cell proliferation and apoptosis and play critical roles in cancer progression. Accumulating studies have demonstrated that miR-1301-3p could regulate the development and progression of multiple cancers, but its biological behaviors in breast cancer (BC) are still elusive.

METHODS

The expression of miR-1301-3p was determined in BC tissues and cell lines using quantitative real-time PCR analysis. The effects of miR-1301-3p on BC cell growth, proliferation, cell cycle distribution, and apoptosis were also explored in vitro using MTT, colony formation and Flow cytometry assays. The potential target gene of miR-1301-3p was determined by dual-luciferase reporter assay and verified by quantitative real-time PCR and western blot analysis.

RESULTS

We found the expression of miR-1301-3p was observably significantly down-regulated in BC tissues and cell lines. MiR-1301-3p expression in BC tissues was significantly associated with tumor size and clinical stage. Gain-of-function assays demonstrated that miR-1301-3p inhibited the cell growth and proliferation in breast cancer cell lines, MCF-7 and T-47D. Moreover, up-regulation of miR-1301-3p induced cell cycle G0/G1 phase arrest and apoptosis. Mechanistically, up-regulation of miR-1301-3p reduced the expression of CDK4, Cyclin D1, Bcl-2, but elevated the expression of p21, Bad and Bax. ICT1 was confirmed as a direct target of miR-1301-3p. Furthermore, ICT1 overexpression could partially reverse the effects of miR-1301-3p on BC cell proliferation, cell cycle progression and apoptosis.

CONCLUSION

Our observations suggested that miR-1301-3p inhibits cell proliferation via inducing cell cycle arrest and apoptosis through targeting ICT1, and might be a therapeutic target for BC.

Constraint-Free Natural Image Reconstruction From fMRI Signals Based on Convolutional Neural Network

In recent years, research on decoding brain activity based on functional magnetic resonance imaging (fMRI) has made eye-catching achievements. However, constraint-free natural image reconstruction from brain activity remains a challenge, as specifying brain activity for all possible images is impractical. The problem was often simplified by using semantic prior information or just reconstructing simple images, including digitals and letters. Without semantic prior information, we present a novel method to reconstruct natural images from the fMRI signals of human visual cortex based on the computation model of convolutional neural network (CNN). First, we extracted the unit output of viewed natural images in each layer of a pre-trained CNN as CNN features. Second, we transformed image reconstruction from fMRI signals into the problem of CNN feature visualization by training a sparse linear regression to map from the fMRI patterns to CNN features. By iteratively optimization to find the matched image, whose CNN unit features become most similar to those predicted from the brain activity, we finally achieved the promising results for the challenging constraint-free natural image reconstruction. The semantic prior information of the stimuli was not used when training decoding model, and any category of images (not constraint by the training set) could be reconstructed theoretically. We found that the reconstructed images resembled the natural stimuli, especially in position and shape. The experimental results suggest that hierarchical visual features may be an effective tool to express the human visual processing.

Understanding the surface properties and rheology of a silica suspension mediated by a comb-type poly(acrylic acid)/poly(ethylene oxide) (PAA/PEO) copolymer: effect of salinity

Understanding the surface properties and rheology of colloidal suspensions in the presence of polymer additives with high salinity are of great importance in formulating construction materials and optimizing process conditions in the mining and petroleum industry. In this work, the surface properties and rheology of a model spherical silica aqueous suspension mediated by a comb-type poly(acrylic acid)/poly(ethylene oxide) (PAA/PEO) copolymer at various salt concentrations have been investigated. Adsorption measurements using a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) align well with zeta potential tests and show that polymer adsorption on silica surfaces is enhanced at high salinity (i.e., 3 M NaCl) than at low salinity (i.e., 1 mM NaCl) due to the suppression of the electrical double layer. Surface Forces Apparatus (SFA) measurements reveal that for interactions between two mica surfaces (the basal plane of which has a similar structure as silica) at a high polymer concentration (e.g., 2 wt%), steric repulsion dominates in 1 mM NaCl while bridging attraction is observed in 3 M NaCl. Surface force measurements agree with rheological results on silica suspensions with 0.5 to 2 wt% of PAA/PEO addition, which shows a significant decrease in yield stress in 1 mM NaCl due to steric repulsion but an insignificant variation in yield stress in 3 M NaCl due to attractive bridging interactions. This work provides useful information regarding the surface properties and rheological properties of comb-type polymer-mediated silica suspensions under different salinity conditions, with implications on designing and processing complex colloidal suspensions with polymer additives for various applications.

[The impact of resection of skull base tumor via an endoscopic endonasal approach on the visual function of vision impaired patients and the analysis of factors affecting their visual recovery]

Objective: To evaluate the visual outcomes of patients with visual impairment after resecting skull base tumor via an endoscopic endonasal approach, and to analyze the factors affecting visual recovery. Methods: One hundred and fifty-three patients with skull base tumor who suffered from preoperative visual impairment from Skull Base Surgery Center of Xuanwu Hospital were operated through an endoscopic endonasal approach. Both preoperative and postoperative visual function outcomes as well as factors that might have affected their visual recovery were analyzed retrospectively by Chi square test and Logistic regression analysis. Results: Complete resection was achieved in 85.6% of the patients using this technique. The rate of postoperative visual recovery in the female group (86.1%) was higher than that in the male group (73.9%), the benign group (90.2%) higher than the malignant group (20.0%), the group without optic atrophy (97.1%) higher than the one with (51.2%), and the acute group (96.6%) higher than the chronic group (80.0%). Significant differences were found between the abovementioned groups (χ(2) value was 5.849, 87.860, 79.757, 4.745, respectively, all P<0.05). The degree of optic atrophy and the property of tumors were significantly associated with visual improvement after treatment (Wold χ(2) value was 18.597 and 35.623, all P<0.001). Conclusions: Our results indicate that endoscopic endonasal surgery shows its ability both to resect skull base tumors and to improve visual function in the majority of patients. The timing of treatment for patients suffered from preoperative visual impairment should be selected in early stage before optic atrophy occurs.

The association of neck circumference with incident congestive heart failure and coronary heart disease mortality in a community-based population with or without sleep-disordered breathing

Background

Neck circumference (NC), representing upper body subcutaneous adipose tissue, may be correlated with increased risk of overweight/obesity, obstructive sleep apnoea, and metabolic and cardiovascular disease. However, the relationship between NC and the incidence of congestive heart failure (CHF) or mortality due to coronary heart disease (CHD) in a community-based population with and without sleep-disordered breathing (SDB) has not yet been clarified.

Methods

We performed a prospective study using the Sleep Heart Health Study (SHHS) cohort. Cox proportional hazards regression models were used to estimate the association of different levels of NC with CHF incidence or CHD mortality in 2234 individuals with SDB and 2199 without SDB, respectively.

Results

After adjusting for age, sex, and body mass index (BMI), NC was significantly associated with CHF when comparing the highest NC quartile group with the lowest (hazard ratio, HR, 2.265, 95% confidence interval, CI, 1.074–4.777) in the non-SDB population. This association diminished after further adjustment for other risk factors, but remained statistically significant, with an adjusted HR of 1.082 (95% CI 1.003–1.166) per unit increase in NC. Additionally, after adjustment for age, sex, and BMI, NC was also shown to be remarkably associated with CHD mortality (HR 1.141, 95% CI 1.014–1.282) per unit increase in NC in the non-SDB population but not in the SDB population. After adjustment for all the covariates, there was a significant association between NC and CHD death in those without SDB, with an adjusted HR of 1.134 (95% CI 1.001–1.284) per unit increase in NC.

Conclusions

NC may correlate with CHF incidence and CHD mortality in population without SDB. NC measurement may help risk stratification for cardiovascular diseases.

Trial registration

NCT00005275, January 1994.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0846-9) contains supplementary material, which is available to authorized users.

Nuclear EGFR-PKM2 axis induces cancer stem cell-like characteristics in irradiation-resistant cells

Radiation therapy has become an important tool in the treatment of cancer patients, but most patients relapse within 5 years. Relapse is due to the presence of cancer stem cells (CSCs), but the molecular mechanism of radioresistance in CSCs remains largely elusive. Here, we found that irradiation-resistant (IR) cells exhibited increased stem cell-like properties together with elevated anchorage-independent growth and metastasis ability. EGFR not only leads to increased acquisition of endometrial cancer stem cell markers in radioresistant sublines but is critical for the cancer stem-cell phenotype and tumorigenicity. Moreover, PKM2 functions as an interacting partner of EGFR, which induces the EMT phenotype and stem cell-like properties in IR cells. Finally, we found that the regulatory function of the EGFR-PKM2 axis is dependent on nuclear EGFR. In sum, our study indicated that EGFR and PKM2 directly interact and bind with each other to regulate the transcription of stemness-related genes and promote the stem-like phenotype, thus promoting invasion and metastasis.

Regenerable urchin-like Fe3O4@PDA-Ag hollow microspheres as catalyst and adsorbent for enhanced removal of organic dyes

In this work, novel urchin-like Fe₃O₄@polydopamine (PDA)-Ag hollow microspheres have been prepared via a facile synthesis method by in situ reduction and growth of Ag nanoparticles on mussel-inspired PDA layers coated on Fe₃O₄ hollow cores. The catalytic reduction efficiency and adsorption performance of the as-prepared urchin-like Fe₃O₄@polydopamine (PDA)-Ag hollow microspheres for model organic dyes (i.e., methylene blue and rhodamine B) under varying pH condition have been systematically investigated, which are demonstrated to be significantly enhanced as compared to that of spherical (relatively smooth) solid Fe₃O₄@PDA-Ag microspheres. The as-prepared urchin-like Fe₃O₄@PDA-Ag hollow microspheres show high reusability, easy separability, and fast regeneration ability, with no obvious drop in the catalytic and adsorption efficiency after cyclic reuse. The versatile PDA coatings on the urchin-like microspheres allow further surface functionalization for development of multifunctional catalyst and adsorbent materials. This work provides a very useful and facile methodology for synthesizing and tuning the urchin-like morphology of Fe₃O₄@PDA-Ag microspheres, with great potential applications in catalysis and wastewater treatment.

Anti-deception: reliable EEG-based biometrics with real-time capability from the neural response of face rapid serial visual presentation

Background

The electroencephalogram (EEG) signal represents a subject’s specific brain activity patterns and is considered as an ideal biometric given its superior invisibility, non-clonality, and non-coercion. In order to enhance its applicability in identity authentication, a novel EEG-based identity authentication method is proposed based on self- or non-self-face rapid serial visual presentation.

Results

In contrast to previous studies that extracted EEG features from rest state or motor imagery, the designed paradigm could obtain a distinct and stable biometric trait with a lower time cost. Channel selection was applied to select specific channels for each user to enhance system portability and improve discriminability between users and imposters. Two different imposter scenarios were designed to test system security, which demonstrate the capability of anti-deception. Fifteen users and thirty imposters participated in the experiment. The mean authentication accuracy values for the two scenarios were 91.31 and 91.61%, with 6 s time cost, which illustrated the precision and real-time capability of the system. Furthermore, in order to estimate the repeatability and stability of our paradigm, another data acquisition session is conducted for each user. Using the classification models generated from the previous sessions, a mean false rejected rate of 7.27% has been achieved, which demonstrates the robustness of our paradigm.

Conclusions

Experimental results reveal that the proposed paradigm and methods are effective for EEG-based identity authentication.

Ribosomal RNA Biogenesis and Its Response to Chilling Stress in Oryza sativa

Ribosome biogenesis is crucial for plant growth and environmental acclimation. Processing of ribosomal RNAs (rRNAs) is an essential step in ribosome biogenesis and begins with transcription of the rDNA. The resulting precursor-rRNA (pre-rRNA) transcript undergoes systematic processing, where multiple endonucleolytic and exonucleolytic cleavages remove the external and internal transcribed spacers (ETS and ITS). The processing sites and pathways for pre-rRNA processing have been deciphered in Saccharomyces cerevisiae and, to some extent, in Xenopus laevis, mammalian cells, and Arabidopsis (Arabidopsis thaliana). However, the processing sites and pathways remain largely unknown in crops, particularly in monocots such as rice (Oryza sativa), one of the most important food resources in the world. Here, we identified the rRNA precursors produced during rRNA biogenesis and the critical endonucleolytic cleavage sites in the transcribed spacer regions of pre-rRNAs in rice. We further found that two pre-rRNA processing pathways, distinguished by the order of 5' ETS removal and ITS1 cleavage, coexist in vivo. Moreover, exposing rice to chilling stress resulted in the inhibition of rRNA biogenesis mainly at the pre-rRNA processing level, suggesting that these energy-intensive processes may be reduced to increase acclimation and survival at lower temperatures. Overall, our study identified the pre-rRNA processing pathway in rice and showed that ribosome biogenesis is quickly inhibited by low temperatures, which may shed light on the link between ribosome biogenesis and environmental acclimation in crop plants.

Activation of AhR with nuclear IKKα regulates cancer stem-like properties in the occurrence of radioresistance

Most cancer patients receive radiotherapy in the course of their disease and the occurrence of radioresistance is associated with poor prognosis. The molecular pathways that drive enhanced tumorigenic potential during the development of radioresistance are poorly understood. Here, we demonstrate that aryl hydrocarbon receptor (AhR) plays a vital role in the maintenance of cancer stem-like properties. AhR promotes the cancer stem-like phenotype and drives metastasis by directly targeting the promoters of 'stemness' genes, such as the ATP-binding cassette sub-family G member 2 (ABCG2) gene. Moreover, the radioresistant sublines display high levels of oncometabolites including α-ketoglutarate, and treatment of cancer cells with α-ketoglutarate enhances their stem-like properties in an AhR activation-dependent manner. IKKα directly activates stemness-related genes through an interaction with AhR as a bone fide chromatin modifier. Thus, AhR is functionally linked with cancer stem-like properties, and it drives tumorigenesis in the occurrence of radioresistance.

Block-matching sparsity regularization-based image reconstruction for low-dose computed tomography

PURPOSE

Low-dose computed tomography (CT) imaging has been widely explored because it can reduce the radiation risk to human bodies. This presents challenges in improving the image quality because low radiation dose with reduced tube current and pulse duration introduces severe noise. In this study, we investigate block-matching sparsity regularization (BMSR) and devise an optimization problem for low-dose image reconstruction.

METHOD

The objective function of the program is built by combining the sparse coding of BMSR and analysis error, which is subject to physical data measurement. A practical reconstruction algorithm using hard thresholding and projection-onto-convex-set for fast and stable performance is developed. An efficient scheme for the choices of regularization parameters is analyzed and designed.

RESULTS

In the experiments, the proposed method is compared with a conventional edge preservation method and adaptive dictionary-based iterative reconstruction. Experiments with clinical images and real CT data indicate that the obtained results show promising capabilities in noise suppression and edge preservation compared with the competing methods.

CONCLUSIONS

A block-matching-based reconstruction method for low-dose CT is proposed. Improvements in image quality are verified by quantitative metrics and visual comparisons, thereby indicating the potential of the proposed method for real-life applications.

Long non-coding RNA phosphatase and tensin homolog pseudogene 1 suppresses osteosarcoma cell growth via the phosphoinositide 3-kinase/protein kinase B signaling pathway

Osteosarcoma is a common type of human carcinoma, which exhibits a high metastasis and recurrence rate. Previous studies have indicated that long non-coding RNA phosphatase and tensin homolog pseudogene 1 (lnPTENP1) has tumor suppressive action by modulating PTEN expression in different types of tumor cells. However, the potential mechanism by which lnPTENP1 has an effect in osteosarcoma cells remains elusive. In the present study, the role of lnPTENP1 in osteosarcoma cells was investigated and the possible mechanisms by which it functions were explored. It was revealed that lnPTENP1 transfection significantly inhibited osteosarcoma cell growth, proliferation, migration and invasion. LnPTENP1 transfection also significantly promoted apoptosis in Mg63 cells treated with tunicamycin. Further analysis revealed that lnPTENP1 transfection regulated osteosarcoma cell growth via the PI3K/AKT signaling pathway. In vivo assays revealed that lnPTENP1 transfection significantly inhibited osteosarcoma tumor growth and significantly increased the protein expression and phosphorylation levels of PI3K and AKT. In conclusion, the results of the present study indicated that lnPTENP1 may inhibit osteosarcoma cell growth via the PI3K/AKT signaling pathway, which may be a potential novel target for human osteosarcoma therapy.

[Advances in surgical techniques of periodontal corticotomy]

The number of adults seeking orthodontic treatment is increasing. Shortening the course of orthodontic treatment has become a research hotspot in recent years. Methods of accelerating tooth movement have been reported. Theoretical and clinical studies have confirmed that periodontal corticotomy is effective in accelerating tooth movement and increasing osteogenic potential. Many surgical techniques of periodontal corticotomy have been developed. This review summarizes the history of periodontal corticotomy and the development of the surgical techniques in recent years, thereby providing references for the clinical application of corticotomy.

Application of a double-colour upconversion nanofluorescent probe for targeted imaging of mantle cell lymphoma

Upconversion nanoparticles are a new type of fluorescent marker in biomedical imaging that can convert a longer wavelength (such as near-infrared fluorescence) into a shorter wavelength (such as visible light). Mantle cell lymphoma, which is derived from B-cell lymphoma, is a subtype of non-Hodgkin's lymphoma, and the immune phenotype is a mature B-cell phenotype (CD20+, CD5+). To develop the use of nanomaterials as specific markers for the medical imaging of mantle cell lymphoma, we modified the surface of UCNPs by oxidation so that the CD20 or CD5 antibody could covalently attach to the upconversion nanoparticles to form antibody-UCNP conjugates. These antibody-UCNP conjugates were used as fluorescent probes to detect the CD20 or CD5 antigen. Due to the excessive expression of these antigens on the surface of MCL cells and successful strong connection between the antibody and UCNPs, the latter could specifically combine with mantle cell lymphoma cells. Upon near-infrared excitation at 980 nm, cells labelled with UCNPs emitted bright upconversion fluorescence.

Circadian Blood Pressure Variations in Postmenopausal Females with Hypertension

The abnormalities of blood pressure (BP) nocturnal decline have been found to be predictive for carotid plaque and lacunar infarction in patients with hypertension. In this study, BP dipping patterns in postmenopausal females with hypertension were investigated. The nocturnal decline of systolic BP (SBP) was evaluated using 24-hour ambulatory BP monitoring (ABPM). A total of 163 postmenopausal females were eventually included in our study. The prevalence of reverse-dipper BP pattern was 32.3% in females with menopause age in their 40s and 40% in their 50s. However, after multivariate logistic regression analysis, menopause age was shown to be an independent risk factor for BP reverse dipping (Odds ratio [OR] 1.148; 95%CI 1.020 - 1.292; P = 0.020). Moreover, menopause age was negatively correlated with the decline rate of nocturnal SBP (r = -0.159; P < 0.05) and diastolic BP (r = -0.161; P < 0.05). Our study suggested that the menopause age might serve as a risk factor for reverse-dipper BP pattern in postmenopausal females with hypertension.