Photoelectrochemical sensor based on AuNPs@WO3@TpPa-1-COF for quantification of DNA methylation levels.

A "signal-off" photoelectrochemical (PEC) sensing platform has been designed for the ultrasensitive detection of DNA methylation levels and multiple methylated sites. The platform employs tungsten trioxide and TpPa-1-COF loaded by gold nanoparticle (AuNPs@WO3@TpPa-1-COF) composite material as the photoactive component and p-type reduced graphene (rGO) as an efficient quencher. The PEC signal of AuNPs@WO3@TpPa-1-COF composite is effectively quenched in the presence of p-type rGO, because p-type rGO can compete with AuNPs@WO3@TpPa-1-COF to deplete light energy and electron donors. In addition, a hybrid strand reaction (HCR) amplification strategy fixes more target DNA and then combines with rGO-modified anti-5-methylcytosine antibody to facilitate ultrasensitive DNA methylation detection. Under optimal conditions, DNA methylation can be measured within a linear concentration range of 10-14 to 10-8 M, with an exceptionally low detection limit of 0.19 fM (S/N = 3). At the same time, the platform can conduct quantitative determination of multi-site methylation, with the linear equation △I = 44.19LogA + 61.43, and the maximum number of methylation sites is 5. The sensor demonstrates high sensitivity, excellent selectivity, and satisfactory stability. Furthermore, the proposed signal-off PEC strategy was successfully employed to detect DNA methylation in spiked human serum samples, with recoveries ranging from 93.17 to 107.28% and relative standard deviation (RSD) ranging from 1.15 to 5.49%.

Pathological Diagnosis of Adult Craniopharyngioma on MR Images: An Automated End-to-End Approach Based on Deep Neural Networks Requiring No Manual Segmentation.

PURPOSE: The goal of this study was to develop end-to-end convolutional neural network (CNN) models that can noninvasively discriminate papillary craniopharyngioma (PCP) from adamantinomatous craniopharyngioma (ACP) on MR images requiring no manual segmentation. MATERIALS AND METHODS: A total of 97 patients diagnosed with ACP or PCP were included. Pretreatment contrast-enhanced T1-weighted images were collected and used as the input of the CNNs. Six models were established based on six networks, including VGG16, ResNet18, ResNet50, ResNet101, DenseNet121, and DenseNet169. The area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity were used to assess the performances of these deep neural networks. A five-fold cross-validation was applied to evaluate the performances of the models. RESULTS: The six networks yielded feasible performances, with area under the receiver operating characteristic curves (AUCs) of at least 0.78 for classification. The model based on Resnet50 achieved the highest AUC of 0.838 ± 0.062, with an accuracy of 0.757 ± 0.052, a sensitivity of 0.608 ± 0.198, and a specificity of 0.845 ± 0.034, respectively. Moreover, the results also indicated that the CNN method had a competitive performance compared to the radiomics-based method, which required manual segmentation for feature extraction and further feature selection. CONCLUSIONS: MRI-based deep neural networks can noninvasively differentiate ACP from PCP to facilitate the personalized assessment of craniopharyngiomas.

Protective Effect of NGR1 against Glutamate-Induced Cytotoxicity in HT22 Hippocampal Neuronal Cells by Upregulating the SIRT1/Wnt/ß-Catenin Pathway.

Notoginsenoside R1 (NGR1) is an active compound isolated from Panax notoginseng. Despite the NGR1 having been used as a traditional medicine, little is known about the neuroprotective effects. In this study, we investigate the protective effects of NGR1 against glutamate-induced cytotoxicity in HT22 cells and its possible molecular mechanism. We assessed the toxicity of NGR1 and the protective activity by MTT assay. The levels of oxidative stress indices superoxide dismutase (SOD), glutathione (GSH), and mitochondrial membrane potential (MMP) were measured by the kits. The levels of reactive oxygen species (ROS) and Ca2+ concentration were measured by flow cytometry. Furthermore, we determined the expression of mitochondrial dysfunction related protein PINK1, Parkin, silent mating type information regulation 2 homolog-1 (sirtuin 1; SIRT1), and Wnt/ß-catenin by Western blotting. Here, we discovered that glutamate treatment led to cell viability loss, apoptosis facilitation, Ca2+ upregulation, MMP fluorescence intensity downregulation, and ROS generation of HT22 cells. In parallel, expression of Parkin was declined by glutamate. While, NGR1 treatment alleviated all the above phenomena. We further clarified that NGR1 alleviated glutamate-induced oxidative stress, apoptosis, and mitochondrial dysfunction by upregulating SIRT1 to activate Wnt/ß-catenin pathways. These findings demonstrate that NGR1 alleviated glutamate-induced cell damage, and NGR1 may play a protective role in neurological complications.

Annexin A2 promotes liver fibrosis by mediating von Willebrand factor secretion.

BACKGROUND: Liver fibrosis can lead to cirrhosis and hepatocellular carcinoma if not treated in the early stages. The molecular mechanisms of the pathogenesis of hepatic fibrosis remain unclear. AIM: To identify the molecules involved in the pathogenesis of liver fibrosis and to investigate the potential effect and mechanism of Annexin A2 up-regulation during liver fibrosis progression. METHODS: Twenty Sprague-Dawley rats were divided into two groups: the carbon tetrachloride (CCl4)-induced liver fibrosis group and the normal control group. Hematoxylin and eosin staining or Masson Trichrome staining and enzyme-linked immunosorbent assay were applied to assess the degree of liver damage and fibrosis in rats with CCl4-induced liver fibrosis. Liver tissue protein profiles were analyzed using iTRAQ and mass spectrometry. RT-PCR and western blotting analyses were employed to validate differentially expressed proteins. Small interfering RNA-based silencing was performed to study the function of Annexin A2. RESULTS: Twelve weeks after CCl4 injection, significant body weight changes and liver injury and liver fibrosis were observed in rats. In addition, 130 proteins were differentially expressed in the liver fibrosis group. Overexpression of Annexin A2 was confirmed by RT-PCR and Western blotting analysis. Silencing of Annexin A2 expression in HepG2 and LX-2 cells significantly reduced the secretion of von Willebrand factor (vWF). CONCLUSION: Annexin A2 promotes liver fibrosis by mediating vWF secretion, which can be used to mitigate the progression of liver fibrosis.

LHBs can elevate the expression of MDR1 through HIF-1α in patients with CHB infection: a comparative proteomic study.

BACKGROUND AND AIMS: Hepatitis B virus (HBV) infection is a major risk factor for liver cirrhosis and hepatocellular carcinoma (HCC). To gain a better understanding of the pathogenesis of HBV infection, this study aimed to investigate the differentially expressed proteins (DEPs) in liver tissues from patients with chronic hepatitis B (CHB) infection. RESULTS: Seventy-one DEPs were identified. Overexpression of multi-drug resistance protein 1 (MDR1) was validated by RT-qPCR and western blot analyses. Moreover, its expression was increased at both the mRNA and protein levels in response to overexpression of HBV large surface protein (LHBs). Furthermore, screening of transcription factors suggested the possible involvement of hypoxia-inducible factor 1α (HIF-1α) in the interaction between LHBs and MDR1. The function of HIF-1α in the MDR1 activation was confirmed by EMSA and reporter gene analyses. MATERIALS AND METHODS: Liver samples from CHB patients and controls without HBV infection were collected and subjected to isobaric tags for relative and absolute quantitation (iTRAQ) and mass spectrometric analysis. CONCLUSIONS: These results imply that LHBs, in association with HIF-1α, induces MDR1 overexpression, which may contribute to the pathogenic changes in CHB infection.

A quantitative proteomics study on olfactomedin 4 in the development of gastric cancer.

Gastric cancer (GC) is now one of the most common malignancies with a relatively high incidence and high mortality rate. The prognosis is closely related to the degree of tumor metastasis. The mechanism of metastasis is still unclear. Proteomics analysis is a powerful tool to study and evaluate protein expression in tumor tissues. In the present study, we collected 15 gastric cancer and adjacent normal gastric tissues and used the isobaric tags for relative and absolute quantitation (iTRAQ) method to identify differentially expressed proteins. A total of 134 proteins were differentially expressed between the cancerous and non-cancerous samples. Azurocidin 1 (AZU1), CPVL, olfactomedin 4 (OLFM4) and Villin 1 (VIL1) were upregulated and confirmed by western blot analysis, real-time quantitative PCR and immunohistochemical analyses. These results were in accordance with iTRAQ. Furthermore, silencing the OLFM4 expression suppressed the migration, invasion and proliferation of the GC cells in vitro. The present study represents a successful application of the iTRAQ method in analyzing the expression levels of thousands of proteins. Overexpression of OLFM4 in gastric cancer may induce the development of gastric cancer. Overall, suppression of OLFM4 expression may be a promising strategy in the development of novel cancer therapeutic drugs.

C-reactive protein is a biomarker of AFP-negative HBV-related hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most aggressive cancers worldwide and is associated with the high rates of morbidity and mortality. α-fetoprotein (AFP) is common used in diagnosis of HCC; however, a growing body of research is questioning the diagnostic power of AFP. There is, therefore, an urgent need to develop additional novel non-invasive techniques for the early diagnosis of HCC, particularly for patients with AFP-negative [AFP(-)] HCC. Accordingly, in the present study, we employed iTRAQ-based mass spectro-metry to analyze the plasma proteins of subjects with AFP(-) HBV-related HCC, AFP(+) HBV-related HCC and non-malignant cirrhosis. We identified 14 aberrantly expressed proteins specific to the HCC patients, including 10 upregulated and 4 downregulated proteins. We verified C-reactive protein (CRP) overexpression by ELISA and immunohistochemical staining of clinical samples. Per ROC curve analyses, CRP was positive in 73.3% of patients with HBV-related HCC, and CRP overexpression had significant diagnostic power for AFP(-) HBV-related HCC. Furthermore, we found that silencing CRP caused a >2-fold decease in HBV replication. Additionally, we determined that this reduction in HBV replication involved the interferon-signaling pathway. However, silencing CRP also promoted HCC invasion and migration in vitro. In conclusion, we demonstrated that CRP can serve as a diagnostic biomarker for AFP(-) HBV-related HCC.

iTRAQ-based quantitative proteomic analysis of cervical cancer.

Cervical cancer is the seventh most common cancer overall and the third among females. To obtain systematic insight into the protein profile that participates in cervical tumor oncogenesis and improve the current target therapies, iTRAQ labeling and NanoLC-MS/MS analysis were utilized to detect differentially expressed proteins in cervical cancer. As a result, 3,647 proteins were identified, among which the expression levels of 294 proteins in cervical cancer samples were distinct from the paired non-tumor samples. Further validation of the differentially expressed proteins, including G6PD, ALDH3A1, STAT1 and HSPB1, was carried out via qRT-PCR, western blot analysis and tissue microarray. Functional analysis of one of the highly expressed proteins, G6PD, was performed using RNA interference. Attenuated G6PD expression reduced the capacity of HeLa cells to migrate and invade in vitro. Our investigation complemented the understanding of cervical cancer progression. Furthermore, the present study supports the notion that suppressing the expression of G6PD may be a promising strategy in developing novel cancer therapeutic drugs.