The clinical value of head-neck joint high-resolution vessel wall imaging in ischemic stroke.

BACKGROUND AND PURPOSE: To study the feasibility and clinical utility of head-neck joint high-resolution vessel wall imaging (HNJ-VWI) in the assessment of ischemic stroke. METHODS: We reviewed our institutional HNJ-VWI database. Patients with transient ischemic attack (TIA) or ischemic stroke were included. Abnormal findings of intracranial and/or extracranial artery were assessed on three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) and HNJ-VWI modified from high-resolution 3D T1 sequence and classified into three groups including intracranial, extracranial and coexisting based on the locations. Etiologies of stroke were recorded according to Trial of Org 10172 in Acute Stroke Treatment criteria. RESULTS: One hundred and ten consecutive patients were studied. 3D TOF MRA displayed 71.8% (79/110, based on patients) abnormal arteries (stenosis or occlusion) , while HNJ-VWI displayed 96.3% (106/110) abnormal arteries (plaque,wall thickness and occlusion) including four isolated extracranial lesions and ten coexisting lesions. The etiologies of TIA/ischemic stroke included large artery atherosclerosis (80 cases), cerebral small vessel disease (6 cases), cardiogenic (2 cases), dissection (6 cases), vasculitis (4 cases), moyamoya disease (6 cases), others (2 cases) and undetermined (4 cases). For patients with atherosclerosis stroke, re-infarctions were more common in coexisting group than intracranial group (extracranial vs. intracranial vs coexisting: 0% vs. 9.1% vs. 43.7%, p = 0.001). CONCLUSIONS: HNJ-VWI is a feasible and valuable technique in assessment of ischemic stroke by detecting extracranial and intracranial artery abnormalities with one-step scan.

Blocking Effect of Demethylzeylasteral on the Interaction between Human ACE2 Protein and SARS-CoV-2 RBD Protein Discovered Using SPR Technology.

The novel coronavirus disease (2019-nCoV) has been affecting global health since the end of 2019, and there is no sign that the epidemic is abating. Targeting the interaction between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and the human angiotensin-converting enzyme 2 (ACE2) receptor is a promising therapeutic strategy. In this study, surface plasmon resonance (SPR) was used as the primary method to screen a library of 960 compounds. A compound 02B05 (demethylzeylasteral, CAS number: 107316-88-1) that had high affinities for S-RBD and ACE2 was discovered, and binding affinities (KD, µM) of 02B05-ACE2 and 02B05-S-RBD were 1.736 and 1.039 µM, respectively. The results of a competition experiment showed that 02B05 could effectively block the binding of S-RBD to ACE2 protein. Furthermore, pseudovirus infection assay revealed that 02B05 could inhibit entry of SARS-CoV-2 pseudovirus into 293T cells to a certain extent at nontoxic concentration. The compoundobtained in this study serve as references for the design of drugs which have potential in the treatment of COVID-19 and can thus accelerate the process of developing effective drugs to treat SARS-CoV-2 infections.

Adaptively capturing the heterogeneity of expression for cancer biomarker identification.

BACKGROUND: Identifying cancer biomarkers from transcriptomics data is of importance to cancer research. However, transcriptomics data are often complex and heterogeneous, which complicates the identification of cancer biomarkers in practice. Currently, the heterogeneity still remains a challenge for detecting subtle but consistent changes of gene expression in cancer cells. RESULTS: In this paper, we propose to adaptively capture the heterogeneity of expression across samples in a gene regulation space instead of in a gene expression space. Specifically, we transform gene expression profiles into gene regulation profiles and mathematically formulate gene regulation probabilities (GRPs)-based statistics for characterizing differential expression of genes between tumor and normal tissues. Finally, an unbiased estimator (aGRP) of GRPs is devised that can interrogate and adaptively capture the heterogeneity of gene expression. We also derived an asymptotical significance analysis procedure for the new statistic. Since no parameter needs to be preset, aGRP is easy and friendly to use for researchers without computer programming background. We evaluated the proposed method on both simulated data and real-world data and compared with previous methods. Experimental results demonstrated the superior performance of the proposed method in exploring the heterogeneity of expression for capturing subtle but consistent alterations of gene expression in cancer. CONCLUSIONS: Expression heterogeneity largely influences the performance of cancer biomarker identification from transcriptomics data. Models are needed that efficiently deal with the expression heterogeneity. The proposed method can be a standalone tool due to its capacity of adaptively capturing the sample heterogeneity and the simplicity in use. SOFTWARE AVAILABILITY: The source code of aGRP can be downloaded from https://github.com/hqwang126/aGRP .

Resveratrol induced ER expansion and ER caspase-mediated apoptosis in human nasopharyngeal carcinoma cells.

Autophagy and endoplasmic reticulum (ER) stress response is important for cancer cells to maintain malignancy and resistance to therapy. trans-Resveratrol (RSV), a non-flavonoid agent, has been shown to induce apoptosis in human nasopharyngeal carcinoma (NPC) cells. In this study, the involvements of tumor-specific ER stress and autophagy in the RSV-mediated apoptosis were investigated. In addition to traditional autophagosomes, the images of transmission electron microscopy (TEM) indicated that RSV markedly induced larger, crescent-shaped vacuoles with single-layered membranes whose the expanded cisternae contains multi-lamellar membrane structures. Prolonged exposure to RSV induced a massive accumulation of ER expansion. Using an EGFP-LC3B transfection and confocal laser microscopy approach, we found RSV-induced EGFP-LC3 puncta co-localized with ER-tracker red dye, implicating the involvement of LC3II in ER expansion. The proapoptotic effect of RSV was enhanced after suppression of autophagy by ATG7 siRNA or blocking the autophagic flux by bafilomycin A1, but that was not changed after targeted silence of IRE1 or CHOP by siRNA. Using caspase inhibitors, we demonstrated the upregulation of caspase-12 (casp12) and the activation of casp4 were associated with the proapoptotic induction of RSV through the caspase-9/caspase-3 pathway. Intriguingly, siRNA knockdown of casp12, but not caspase-4, decreased the susceptibility of the NPC cells to RSV-mediated apoptosis. Further, we showed that RSV dose-dependently increased the ceramide accumulation as assessed by LC-MS/MS system. Using serine palmitoyltransferase (SPT, a key enzyme of de novo ceramide biosynthesis) inhibitors (L-cycloserine and myriocin), we found the increased ceramide accumulation was strongly correlated with the proapoptotic potential of RSV. This study revealed the ER expansion and upregulation of ER casp12 together may indicate profound biological effects of RSV and contributed to NPC cell death. Targeting the different status of ER stress may provide a possible strategy for cancer treatments.

Associations of sedentary behavior and physical activity with psychological distress: a cross-sectional study from Singapore.

BACKGROUND: Emerging evidence suggests the adverse association between sedentary behaviour (SB) with physical and mental health, but few studies have investigated the relationship between volume of physical activity and psychological distress. The present study examined the independent and interactive associations of daily SB and weekly level of moderate to vigorous physical activity (MVPA) with psychological distress in a multi-ethnic Asian population. METHODS: De-identified data of 4,337 adults (18-79 years old) on sedentary behaviors, physical activity patterns, psychological distresses, and other relevant variables were obtained from the Singapore Ministry of Health's 2010 National Health Survey. Psychological distress was assessed using General Health Questionnaire-12 (GHQ-12), whereas total daily SB and total weekly volume (MET/minutes) of MVPA were estimated using the Global Physical Activity Questionnaire version 2 (GPAQ v2). Multivariate logistic regression analyses were carried out to estimate the odds ratios (95% confidence intervals) of the independent and interactive relationships of SB and MVPA with prevalence of psychological distress. RESULTS: The category of high SB was positively associated with increased odds (OR = 1.29, 1.04-1.59) for psychological distress, whereas the category of active was inversely associated with lower odds (OR = 0.73, 0.62-0.86) for psychological distress. Multivariate analyses for psychological distress by combined daily SB and weekly MVPA levels showed inverse associations between middle SB and active categories (OR = 0.58, 0.45 - 0.74) along with low SB and active categories (OR = 0.61, 0.47-0.80). CONCLUSIONS: The present population-based cross-sectional study indicated that in the multi-ethnic Asian society of Singapore, a high level of SB was independently associated with psychological distress and meeting the recommended guidelines for physical activity along with ≤ 5 h/day of SB was associated with the lowest odds of psychological distress.

Molecular properties, structure, neurotrophic and anti-inflammatory activities of cultured secondary metabolites from the cultures of the mushroom Cyathus striatus CBPFE A06.

Two previously undescribed natural cyathane diterpenoids Me-dentifragilin A (1) and Epi-neocyathin O (2), and three known cyathane diterpenoids 3-5, cyathin O, neocyathin P, and cyathin I, were isolated from the rice medium of the Cyathus striatus CBPFE A06. Their structures were established by NMR spectra, and HR-ESI-MS. Compounds 1-5 displayed encouraging neurotrophic activity in PC-12 cells at doses of 5 µM. Meanwhile, 1-5 significantly inhibited LPS-induced NO generation in BV2 cells with the IC50 values ranging from 2.44 ± 0.16 to 4.33 ± 0.32 µM. Western blot analysis showed that 2 and 4 inhibited the expression of genes involved in nitric oxide (NO) production. Molecular docking revealed that five residues of inducible NO synthase (iNOS) are key residues affecting the interaction of 2 and 4 with iNOS. This study enriches the structural diversity of cyathane diterpenes and adds to the evidence that cyathane diterpenes prevent and treat neurodegenerative diseases.

Molecular mechanism of the negative regulation of Smad1/5 protein by carboxyl terminus of Hsc70-interacting protein (CHIP).

The transforming growth factor-ß (TGF-ß) superfamily of ligands signals along two intracellular pathways, Smad2/3-mediated TGF-ß/activin pathway and Smad1/5/8-mediated bone morphogenetic protein pathway. The C terminus of Hsc70-interacting protein (CHIP) serves as an E3 ubiquitin ligase to mediate the degradation of Smad proteins and many other signaling proteins. However, the molecular mechanism for CHIP-mediated down-regulation of TGF-ß signaling remains unclear. Here we show that the extreme C-terminal sequence of Smad1 plays an indispensable role in its direct association with the tetratricopeptide repeat (TPR) domain of CHIP. Interestingly, Smad1 undergoes CHIP-mediated polyubiquitination in the absence of molecular chaperones, and phosphorylation of the C-terminal SXS motif of Smad1 enhances the interaction and ubiquitination. We also found that CHIP preferentially binds to Smad1/5 and specifically disrupts the core signaling complex of Smad1/5 and Smad4. We determined the crystal structures of CHIP-TPR in complex with the phosphorylated/pseudophosphorylated Smad1 peptides and with an Hsp70/Hsc70 C-terminal peptide. Structural analyses and subsequent biochemical studies revealed that the distinct CHIP binding affinities of Smad1/5 or Smad2/3 result from the nonconservative hydrophobic residues at R-Smad C termini. Unexpectedly, the C-terminal peptides from Smad1 and Hsp70/Hsc70 bind in the same groove of CHIP-TPR, and heat shock proteins compete with Smad1/5 for CHIP interaction and concomitantly suppress, rather than facilitate, CHIP-mediated Smad ubiquitination. Thus, we conclude that CHIP inhibits the signaling activities of Smad1/5 by recruiting Smad1/5 from the functional R-/Co-Smad complex and further promoting the ubiquitination/degradation of Smad1/5 in a chaperone-independent manner.

Molecular basis of Wnt activation via the DIX domain protein Ccd1.

The Wnt signaling plays pivotal roles in embryogenesis and cancer, and the three DIX domain-containing proteins, Dvl, Axin, and Ccd1, play distinct roles in the initiation and regulation of canonical Wnt signaling. Overexpressed Dvl has a tendency to form large polymers in a cytoplasmic punctate pattern, whereas the biologically active Dvl in fact forms low molecular weight oligomers. The molecular basis for how the polymeric sizes of Dvl proteins are controlled upon Wnt signaling remains unclear. Here we show that Ccd1 up-regulates canonical Wnt signaling via acting synergistically with Dvl. We determined the crystal structures of wild type Ccd1-DIX and mutant Dvl1-DIX(Y17D), which pack into "head-to-tail" helical filaments. Structural analyses reveal two sites crucial for intra-filament homo- and hetero-interaction and a third site for inter-filament homo-assembly. Systematic mutagenesis studies identified critical residues from all three sites required for Dvl homo-oligomerization, puncta formation, and stimulation of Wnt signaling. Remarkably, Ccd1 forms a hetero-complex with Dvl through the "head" of Dvl-DIX and the "tail" of Ccd1-DIX, depolymerizes Dvl homo-assembly, and thereby controls the size of Dvl polymer. These data together suggest a molecular mechanism for Ccd1-mediated Wnt activation in that Ccd1 converts latent polymeric Dvl to a biologically active oligomer(s).

Association of carotid artery geometries with middle cerebral artery atherosclerosis.

BACKGROUND AND AIMS: Evidence shows that artery geometries play a role in atherogenesis by influencing blood flow dynamics. However, whether upstream artery geometries influence downstream atherosclerosis remains unclear. We aimed to investigate whether carotid artery geometries were associated with middle cerebral artery (MCA) atherosclerosis. METHODS: We reviewed our institutional database of 3-dimensional head-neck combined high-resolution magnetic resonance imaging. The carotid artery geometries, carotid atherosclerosis, MCA configurations, and MCA atherosclerosis were examined. The associations between carotid artery geometry and MCA atherosclerosis were also analyzed. A final model integrating carotid artery geometries was established, and the incremental diagnostic value was evaluated and compared to a basic model that included only traditional risk factors. RESULTS: Among the 575 artery units of the ipsilateral carotid artery and MCA, the artery units with MCA plaques (n = 273) were associated with a larger bifurcation angle (odds ratio [OR], 1.138 per 10-degree increase; 95% confidential interval [CI], 1.023-1.264) and kinking-type extracranial internal carotid artery (ICA; OR, 2.193; 95%CI, 1.283-3.748) compared with those without MCA plaques (n = 302). These associations were independent of traditional risk factors, carotid atherosclerosis, and MCA configuration. A larger carotid bifurcation angle was also associated with tandem ICA and MCA atherosclerosis (OR, 1.211 per 10-degree increase; 95%CI, 1.110-1.321). The incremental diagnostic value of carotid artery geometry to traditional risk factors was revealed by comparing the area under the curves of the two diagnostic models (basic model, 0.673 vs. final model, 0.701; p = 0.016). CONCLUSIONS: Carotid artery geometries are independently associated with ipsilateral MCA atherosclerosis, providing new insights into the pathophysiology of intracranial atherosclerosis.

ZIF-8 with cationic defects toward efficient 125I2 uptake for in vitro radiotherapy of colon cancer.

Introducing 2,3-dimethyl-1H-imidazol-3-ium iodide (Dmim) as a monodentate ligand during the preparation of ZIF-8 yields ZIF-8 + (50) and ZIF-8 + (38) with cationic 'missing linker' defects. ZIF-8 + (38) adsorbs 125I2 and the resulting radioactive host-guest complex exhibits in vitro cytotoxicity comparable to that of Na125I against colon cancer cell line CT26.

Essential oil from the roots of Paeonia lactiflora pall. has protective effect against corticosterone-induced depression in mice via modulation of PI3K/Akt signaling pathway.

For thousands of years, the roots of Paeonia lactiflora Pall (PLP) has been considered by traditional Chinese medicine as a drug that can improve mental or emotional disorders, including depression, anxiety and affective disorders. Unfortunately, the research on the mechanism of action and active ingredients of this beneficial drug is not comprehensive. This study focused on the activity of essential oil from PLP (EOP), systematically studied the antidepressant effect of EOP for the first time, and discussed the potential mechanism of its antidepressant effect. In this study, we used a mouse model of corticosterone (CORT)-induced depression, and found that EOP had a significant antidepressant effect on the symptoms of CORT-induced depression in mice, and significantly down-regulated the levels of CRH, ACTH and cortisol in the brain tissues of mice. In addition, we found that EOP treatment alleviated CORT-induced hippocampal neuron injury in mice In vitro experiments. It was also found that EOP could inhibit CORT-induced apoptosis and improve the proliferation ability and cell viability of PC12 cells. Further, with the help of network analysis, it was revealed that PI3K-Akt might be one of the main signaling pathways of EOP against CORT-induced hippocampal neuron apoptosis. In this study, we also found that EOP up-regulated the phosphorylation of PI3K and Akt in CORT-induced mouse hippocampal neurons and PC12 cells, and promoted the nuclear transcription of Nrf2 in CORT-induced PC12 cells. In conclusion, with the integrated approach, we demonstrated that EOP exerted anti-apoptotic effects on hippocampal neurons through PI3K/Akt/Nrf2 signaling pathway.

Association of high PM2.5 levels with short-term and medium-term lung function recovery in patients with pulmonary lobectomy.

The association between exposure to ambient fine particulate matter with an aerodynamic diameter of ≤ 2.5 µm (PM2.5) and short- and medium-term lung function recovery (LFR) in patients undergoing lobectomy remains uncertain. This study investigated the associations between PM2.5 concentrations and LFR in adult patients (n = 526) who underwent video-assisted thoracoscopic (VATS) lobectomy in Guangzhou, China between January 2018 and June 2021. All patients underwent at least two spirometry tests. Environmental PM2.5 concentrations in the same period were collected from the nearest monitoring station. A multiple linear regression (MLR) model was employed to investigate the associations between changes in PM2.5 concentrations and LFR in patients who underwent lobectomy after adjusting for potential confounders. We assessed short- and medium-term LFR in patients who underwent lobectomy. The three- and 6-month average PM2.5 concentrations in each patient's residential area were divided into regional mild pollution (PM2.5 <25 µg/m3), moderate pollution (25 µg/m3 ≤ PM2.5 <35 µg/m3), and severe pollution (35 µg/m3 ≤ PM2.5) periods. The MLR model confirmed that PM2.5 was an independent risk factor affecting short-term forced lung capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximum expiratory flow at 50% vital capacity (MEF50) recovery (adjusted P = 0.041, 0.014, 0.016, respectively). The MLR model confirmed that PM2.5 was an independent risk factor affecting medium-term MEF50 recovery (adjusted P = 0.046). Compared with the moderate and severe pollution periods, the short- and medium-term LFR (FVC, FEV1, MEF50) of patients in the mild pollution period were faster and better (P < 0.001, P < 0.001, P < 0.001, P = 0.048, P = 0.010, P = 0.013, respectively). Thus, exposure to high PM2.5 levels was associated with significantly reduced speed and degree of short- and medium-term LFR in patients who underwent lobectomy.

Moderate Dose Irradiation Induces DNA Damage and Impairments of Barrier and Host Defense in Nasal Epithelial Cells in vitro.

Purpose: Radiotherapy (RT) is the mainstay treatment for head and neck cancers. However, chronic and recurrent upper respiratory tract infections and inflammation have been commonly reported in patients post-RT. The underlying mechanisms remain poorly understood. Method and Materials: We used a well-established model of human nasal epithelial cells (hNECs) that forms a pseudostratified layer in the air-liquid interface (ALI) and exposed it to single or repeated moderate dose γ-irradiation (1Gy). We assessed the DNA damage and evaluated the biological properties of hNECs at different time points post-RT. Further, we explored the host immunity alterations in irradiated hNECs with polyinosinic-polycytidylic acid sodium salt (poly [I:C]) and lipopolysaccharides (LPS). Results: IR induced DNA double strand breaks (DSBs) and triggered DNA damage response in hNECs. Repeated IR significantly reduced basal cell proliferation with low expression of p63/KRT5 and Ki67, induced cilia loss and inhibited mucus secretion. In addition, IR decreased ZO-1 expression and caused a significant decline in the transepithelial electrical resistance (TEER). Moreover, hyperreactive response against pathogen invasion and disrupted epithelial host defense can be observed in hNECs exposed to repeated IR. Conclusion: Our study suggests that IR induced prolonged structural and functional impairments of hNECs may contribute to patients post-RT with increased risk of developing chronic and recurrent upper respiratory tract infection and inflammation.

High-Survival Rate After Microinjection of Mouse Oocytes and Early Embryos With mRNA by Combining a Tip Pipette and Piezoelectric-Assisted Micromanipulator.

Utilizing microinjection to introduce biological molecules such as DNA, mRNA, siRNA, and proteins into the cell is well established to study oocyte maturation and early embryo development in vitro. However, microinjection is an empirical technology. The cellular survival after microinjection is mainly dependent on the operator, and an experienced operator should be trained for a long time, from several months to years. Optimizing the microinjection to be highly efficient and quickly learned should be helpful for new operators and some newly established laboratories. Here, we combined the tip pipette and piezo-assisted micromanipulator to microinject the oocyte and early embryos at different stages of mouse. The results showed that the survival rate after microinjection was more than 85% for cumulus-oocyte complex, germinal vesicle oocyte, two-cell, and four-cell embryos, and close to 100% for MII oocyte and zygotes. The high-rate survival of microinjection can save many experimental samples. Thus, it should be helpful in studying some rare animal models such as aging and conditional gene knockout mice. Furthermore, our protocol is much easier to learn for new operators, who can usually master the method proficiently after several training times. Therefore, we would like to publicly share this experience, which will help some novices master microinjection skillfully and save many laboratory animals.

A narrative review of research progress on FoxM1 in breast cancer carcinogenesis and therapeutics.

OBJECTIVE: The purpose of this review is to clarify the potential roles of forkhead box transcription factor M1 (FoxM1) in the occurrence and progression of breast cancer, as well as the predictive value of FoxM1 as a prognostic biomarker and potential therapeutic target for breast cancer. BACKGROUND: Breast cancer, well-known as a molecularly heterogeneous cancer, is still one of the most frequently diagnosed malignant tumors among females worldwide. Tumor recurrence and metastasis are the central causes of high mortality in breast cancer patients. Many factors contribute to the occurrence and progression of breast cancer, including FoxM1. FoxM1, widely regarded as a classic proliferation-related transcription factor, plays pivotal roles in the occurrence, proliferation, invasion, migration, drug resistance, and epithelial-mesenchymal transition (EMT) processes of multiple human tumors including breast cancer. METHODS: The PubMed database was searched for articles published in English from February 2008 to May 2021 using related keywords such as "forkhead box transcription factor M1", "human breast cancer", "FoxM1", and "human tumor". About 90 research papers and reports written in English were identified, most of which were published after 2015. These papers mainly concentrated on the functions of FoxM1 in the occurrence, development, drug resistance, and treatment of human breast cancer. CONCLUSIONS: Considering that the abnormal expression of FoxM1 plays a significant role in the proliferation, invasion, metastasis, and chemotherapy drug resistance of breast cancer, and its overexpression is closely correlated with the unfavorable clinicopathological characteristics of breast tumor patients, it is considerably important to comprehend the regulatory mechanism of FoxM1 in breast cancer. This will provide strong evidence for FoxM1 as a potential biomarker for the targeted treatment and prognostic evaluation of breast cancer patients.

Extensive intestinal first-pass elimination and predominant hepatic distribution of berberine explain its low plasma levels in rats.

Berberine, one of the most commonly used natural products, exhibits a poor plasma concentration-effect relationship whose underlying mechanisms remain largely unclear. This study was designed to test the hypothesis that extensive first-pass elimination and abundant tissue distribution of berberine may be its specific pharmacokinetic properties. For that, four different dosing routes, intragastric, intraduodenal, intraportal, and intravenous, were used to investigate the gastric, intestinal, and hepatic first-pass elimination of berberine. After intragastric dosing, approximately half of berberine ran intact through the gastrointestinal tract and another half was disposed of by the small intestine, leading to an extremely low extent of absolute oral bioavailability in rats (0.36%). Moreover, the major berberine metabolites were identified and quantified in rat enterocyte S9 fractions, portal vein plasma, and intestinal perfusates; plasma concentrations and tissue distribution of berberine and its major metabolites were determined as well. Data indicated that M1, M2 glucuronide, and M3 were the major metabolites generated from the small intestine and that there was a 70-fold increase in the ratio of the area under the concentration-time curve value for berberine (liver versus plasma). We conclude that intestinal first-pass elimination of berberine is the major barrier of its oral bioavailability and that its high extraction and distribution in the liver could be other important factors that lead to its low plasma levels in rats.

Mechanistic Insight into pH-Dependent Luminol Chemiluminescence in Aqueous Solution.

Luminol is one of the best known chemiluminescent cyclic hydrazides used in basic solution. Owing to the complexity of luminol oxidation, the mechanism of luminol chemiluminescence (CL), especially in aqueous solution, has not yet been fully elucidated. Recent theoretical computations have confirmed that luminol CL originates from the chemiexcitation of a 1,2-dioxane-3,6-dione dianion (CP2-). This seems to be inconsistent with the luminol oxidation in aqueous solutions, where only the decomposition of a monoanionic peroxyketal (L-OOH) is confirmed to yield CL. In this work, we theoretically investigated the complete decomposition of L-OOH and the pKa of key intermediates in aqueous solutions using (time-dependent) density functional theory. L-OOH first cyclizes to an endoperoxide monoanion (EP-). When pH < pKa (EP-), EP- directly decomposes by a retro-Diels-Alder (rDA) reaction to an aminophthalate monoanion (AP-) without CL activity. Moreover, when pH > pKa (EP-), EP- deprotonates to dianionic EP2-, which rapidly eliminates N2 to CP2-, inducing chemiexcitation. This conclusion is supported by the pKa (EP-) ≈ 8 estimated in this work, which is consistent with the pH-dependent profile of luminol CL observed in previous experiments. Thus, the pH-dependent CL determined by the acidity of endoperoxides may provide a theoretical basis to design new cyclic hydrazides with CL activity at different pH.

Tritiated Water Induces Toxicity in Human Umbilical Vein Vascular Endothelial Cells via IL8.

We aimed to determine the toxic effects of tritiated water (HTO) on 12 generations (T1-T12) of human umbilical vein vascular endothelial cells (HUVECs) and elucidate the underlying mechanisms. We evaluated cellular senescence, interleukin (IL) 8 concentrations, and angiogenesis using ß-galactosidase staining, enzyme-linked immunosorbent assay, and in vitro assays, respectively. The adhesion properties of contaminated cells and differentially expressed genes were assessed using the xCELLigence RTCA SP system and gene chip analysis, respectively. We found that long-term exposure to low levels of HTO can reduce the adhesion of HUVECs to the cellular matrix as well as their angiogenic capacity, while increasing their permeability, senescence, and adhesion to monocytes. Interleukin 8 activated the p38 and Epidermal Growth Factor Receptor (EGFR) pathways in HTO-treated cells and hence was identified as a key candidate of biomarker. The present study clarified the toxicity of HTO in vascular endothelial cells and identified IL8 as a novel protective target with important theoretical and practical values.

Testing the utility of DNA barcodes and a preliminary phylogenetic framework for Chinese freshwater mussels (Bivalvia: Unionidae) from the middle and lower Yangtze River.

The middle and lower portions of the Yangtze River basin is the most species-rich region for freshwater mussels in Asia. The management and conservation of the taxa in this region has been greatly hampered by the lack of a well-developed phylogeny and species-level taxonomic framework. In this study, we tested the utility of two mitochondrial genes commonly used as DNA barcodes: the first subunit of the cytochrome oxidase c gene (COI) and the first subunit of the NADH dehydrogenase gene (ND1) for 34 putative species representing 15 genera, and also generated phylogenetic hypotheses for Chinese unionids based on the combined dataset of the two mitochondrial genes. The results showed that both loci performed well as barcodes for species identification, but the ND1 sequences provided better resolution when compared to COI. Based on the two-locus dataset, Bayesian Inference (BI) and Maximum Likelihood (ML) phylogenetic analyses indicated 3 of the 15 genera of Chinese freshwater mussels examined were polyphyletic. Additionally, the analyses placed the 15 genera into 3 subfamilies: Unioninae (Aculamprotula, Cuneopsis, Nodularia and Schistodesmus), Gonideninae (Lamprotula, Solenaia and Ptychorhychus) and Anodontinae (Cristaria, Arconaia, Acuticosta, Lanceolaria, Anemina and Sinoanodonta). Our results contradict previous taxonomic classification that placed the genera Arconaia, Acuticosta and Lanceolaria in the Unioninae. This study represents one of the first attempts to develop a molecular phylogenetic framework for the Chinese members of the Unionidae and will provide a basis for future research on the evolution, ecology, and conservation of Chinese freshwater mussels.