Modulation of miR-466d-3p on Wnt signaling pathway in response to DEPs-induced blood-brain barrier disruption.

BACKGROUND: Diesel exhaust particles (DEPs), a predominant component of ambient particulate matter (PM), are classified as ultrafine particles with the capacity to penetrate the cerebral blood-brain barrier (BBB). This penetration is implicated in the pathogenesis of central nervous system (CNS) disorders. The integrity of the BBB is inextricably linked to cerebrovascular homeostasis and the development of neurodegenerative disease, highlighting the importance of studying the effects and mechanisms of DEPs on BBB function damage. METHODS AND RESULTS: Utilizing mouse cerebral microvascular endothelial cells (bEnd.3 cells) as an in vitro model of the BBB, we explored the detrimental effects of DEPs exposure on BBB permeability and integrity, with particular focus on inflammation, cell apoptosis, and miRNA expression profiles. Our findings revealed that exposure to DEPs at varying concentrations for 48 h resulted in the inhibition of bEND.3 cell proliferation, induction of cell apoptosis, and an upregulation in the secretion of inflammatory cytokines/chemokines and adhesion molecules. The BBB integrity was further compromised, as evidenced by a decrease in trans-epithelial electrical resistance(TEER), a reduction in cytoskeletal F-actin, and diminished tight junction (TJ) protein expression. Microarray analysis revealed that 23 miRNAs were upregulated and 11 were downregulated in response to a 50 µg/mL DEPs treatment, with miR-466d-3p being notably differentially expressed. Wnt3 was identified as a target of miR-466d-3p, with the Wnt signaling pathway being significantly enriched. We validated that miR-466d-3p expression was downregulated, and the protein expression levels of Wnt/ß-catenin and Wnt/PCP signaling components were elevated. The modulation of the Wnt signaling pathway by miR-466d-3p was demonstrated by the transfection of miR-466d-3p mimic, which resulted in a downregulation of Wnt3 and ß-catenin protein expression, and the mRNA level of Daam1, as well as an enhancement of TJ proteins ZO-1 and Claudin-5 expression. CONCLUSIONS: Our study further confirmed that DEPs can induce the disruption of BBB integrity through inflammatory processes. We identified alterations in the expression profile of microRNAs (miRNAs) in endothelial cells, with miR-466d-3p emerging as a key regulator of tight junction (TJ) proteins, essential for maintaining BBB integrity. Additionally, our findings primarily demonstrated that the Wnt/ ß-catenin and Wnt/PCP signaling pathway can be activated by DEPs and are regulated by miR-466d-3p. Under the combined effects of Wnt/PCP and inflammation, there is an ultimate increase in BBB hyperpermeability.

Global trends and burden of stroke attributable to particulate matter pollution from 1990 to 2019.

OBJECTIVE: To investigate the association between particulate matter and the incidence, disability, and mortality of stroke, we reported the burden of stroke attributable to particulate matter (PM2.5) pollution, including ambient particulate matter pollution (APMP) and household air pollution from solid fuels (HAP), from 1990 to 2019. METHODS: We retrieved the detailed data on the burden of stroke attributable to PM2.5 from the Global Burden of Disease (GBD) 2019. The number of disability-adjusted life-years (DALYs) and deaths, age-standardized death rates (ASMR), and age-standardized disability-adjusted life-years rates (ASDR) attributable to PM2.5 were estimated by age, sex, geographical location, socio-demographic index (SDI), and stroke subtypes (ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage). The estimated annual percentage change (EAPC) was calculated to assess the trends in ASDR and ASMR during the period 1990-2019. RESULTS: Regarding stroke subtypes, the proportion of ischemic stroke burden is increasing, while intracerebral hemorrhage carries the heaviest burden. Both APMP and HAP contributed the most to stroke-related deaths and DALYs of stroke among the elderly populations and males. The highest ASDR and ASMR of stroke attributable to APMP were in the middle SDI regions, especially in East Asia. For HAP, the highest ASDR and ASMR were in the low SDI regions, mainly in Oceania. From 1990-2019, in terms of the EAPC results, APMP caused an increased burden of stroke, whereas the impact of HAP significantly fell. The most pronounced increase in ASDR and ASMR for strokes attributed to APMP were in the low-middle SDI and low SDI regions, particularly among the 25-35 age group. CONCLUSIONS: Stroke attributed to PM2.5 is a global health problem, and the patterns and trends were heterogeneous across APMP and HAP. Targeted interventions should be formulated for APMP and HAP.

Nano-Regulator Inhibits Tumor Immune Escape via the "Two-Way Regulation" Epigenetic Therapy Strategy.

Tumor immune escape caused by low levels of tumor immunogenicity and immune checkpoint-dependent suppression limits the immunotherapeutic effect. Herein, a "two-way regulation" epigenetic therapeutic strategy is proposed using a novel nano-regulator that inhibits tumor immune escape by upregulating expression of tumor-associated antigens (TAAs) to improve immunogenicity and downregulating programmed cell death 1 ligand 1 (PD-L1) expression to block programmed death-1 (PD-1)/PD-L1. To engineer the nano-regulator, the DNA methyltransferase (DNMT) inhibitor zebularine (Zeb) and the bromodomain-containing protein 4 (BRD4) inhibitor JQ1 are co-loaded into the cationic liposomes with condensing the toll-like receptor 9 (TLR9) agonist cytosine-phosphate-guanine (CpG) via electrostatic interactions to obtain G-J/ZL. Then, asparagine-glycine-arginine (NGR) modified material carboxymethyl-chitosan (CMCS) is coated on the surface of G-J/ZL to construct CG-J/ZL. CG-J/ZL is shown to target tumor tissue and disassemble under the acidic tumor microenvironment (TME). Zeb upregulated TAAs expression to improve the immunogenicity; JQ1 inhibited PD-L1 expression to block immune checkpoint; CpG promote dendritic cell (DC) maturation and reactivated the ability of tumour-associated macrophages (TAM) to kill tumor cells. Taken together, these results demonstrate that the nano-regulator CG-J/ZL can upregulate TAAs expression to enhance T-cell infiltration and downregulate PD-L1 expression to improve the recognition of tumor cells by T-cells, representing a promising strategy to improve antitumor immune response.

Ultrasound Images under an Optimized Image Processing Algorithm in Guiding the Neurological Safety of Resection of Lumbar Disc Nucleus Pulposus in Spinal Surgery.

This study was aimed at investigating the effect of an optimized image processing algorithm in ultrasound images and the influence of resection of lumbar disc nucleus pulposus in spinal surgery under the guidance of ultrasound images on the neurological safety of patients. A total of 60 patients with lumbar disc herniation were selected and divided randomly into the control group and observation group. Patients from the control group were treated with resection of lumbar disc nucleus pulposus by an X-ray-guided foraminal microscope, and patients from the observation group underwent the ultrasound image-guided surgeries with an optimized image processing algorithm. Then, the treatment of patients from the two groups was compared. The results showed that the radiotherapy time in the control group was 120 ± 6.3 min and the radiotherapy dose was 129 ± 10.3 min/sec, while the radiotherapy time in the observation group was 4.5 ± 1.2 min and the radiotherapy dose was 22 ± 7.7 min/sec. The time and dose of radiotherapy in the observation group were significantly lower than those in the control group (P < 0.05). In the control group, the numbers of significant effective cases, effective cases, and ineffective cases were 8, 16, and 6, respectively, while those in the observation group were 12, 18, and 0, respectively. The comparison between the groups showed that the number of effective cases and the number of effective cases in the observation group were significantly higher than those in the control group, and the number of ineffective cases was significantly lower than that in the control group (P < 0.05). In conclusion, ultrasound-guided percutaneous foraminal lumbar discectomy could improve patients' clinical symptoms, promote clinical efficacy, and reduce postoperative pain symptoms, thereby accelerating the postoperative rehabilitation of patients. Moreover, it was extremely safe for the nerves.

The tumor-suppressive effects of alpha-ketoglutarate-dependent dioxygenase FTO via N6-methyladenosine RNA methylation on bladder cancer patients.

N6-methyladenosine (m6A) methylation participates in the progression of bladder cancer (BCa). Nevertheless, the regulatory mechanism of alpha-ketoglutarate-dependent dioxygenase FTO influencing the BCa progression has still remained elusive. In this study, to investigate the tumor-suppressive effects of FTO via m6A RNA methylation on BCa patients, a total of 15 cancer tissues and adjacent normal tissues (ANTs) were collected from BCa patients who received tumor resection in our hospital from September 2015 to December 2019. We found that the FTO expression was significantly reduced in cancer tissues compared with that in ANTs, which indicated a lower malignant potential and a higher overall survival rate. It was revealed that overexpression of FTO in two human urinary BCa cell lines (HT-1197 and HT-1376) significantly decreased the cell proliferation and invasion abilities compared with the negative controls, whereas the cell apoptosis was markedly enhanced. In addition, we noted that the changes in m6A methylation level mainly appeared at 5' untranslated region (5' UTR) of MALAT1 and NOTCH1 transcripts, and at 3' UTR of CSNK2A2 and ITGA6 transcripts, responding to the overexpression of FTO. Mechanistically, we found that the splicing factor, proline- and glutamine-rich (SFPQ) could influence the FTO-mediated m6A RNA demethylation, eventually affecting the gene expression. This study provided a new insight into the relationship between the FTO expression and the m6A RNA methylation, assisting scholars to better understand the pathogenesis of BCa.

Visible-Light-Responsive Nanofibrous α-Fe2O3 Integrated FeOx Cluster-Templated Siliceous Microsheets for Rapid Catalytic Phenol Removal and Enhanced Antibacterial Activity.

Visible-light-driven environmental contaminants control using 2D photocatalytic nanomaterials with an unconfined reaction-diffusion path is advantageous for public health. Here, cost-effective siliceous composite microsheets (FeSiO-MS) combined with two distinct refined α-Fe2O3 nanospecies as photofunctional catalysts were constructed via a one-pot synthesis approach. Through precise control of Fe2+ precursor addition, specially configured α-Fe2O3 nanofibers combined with FeOx cluster-functionalized siliceous microsheets of ∼15 nm gradually evolved from the iron oxide-bearing molecular sieve, endowing a superior light-response characteristic of the formed nanocomposite. The catalytic experiment along with the ESR study demonstrated that the produced FeSiO-MS showed reinforced photo-Fenton reactivity, which was effective for rapid phenol degradation under visible light radiation. Moreover, the phenol removal process was found to be regulated by the specially configured types and concentrations of iron oxides. Notably, the obtained composites exhibited a considerable visible-light-induced bactericidal effect against E. coli. The constructed FeSiO-MS nanocomposites as integrated and eco-friendly photocatalysts exhibit enormous potentials for environmental and hygienic application.

Novel XTENylated AWRK6 analog with hypoglycemic activity, and anti-HSV-2 potential in combination with double shRNA.

AIMS: To design and evaluate a novel AWRK6 peptide-based long-acting GLP-1 receptor agonist (GLP-1RA) conjugated a recombinant polyethylene glycol mimetic (XTEN protein) with significant therapeutic potential on type 2 diabetes mellitus (T2DM) alone as well as Herpes simplex virus type 2 (HSV-2) infection in combination with double shRNA. MAIN METHODS: First, four AWRK6 analogs (termed XA-1 to XA-4) were designed and produced by solid phase synthesis strategy. Further surface plasmon resonance (SPR) measurement and in vitro cAMP accumulation assay were performed to detect the GLP-1R binding affinities and GLP-1R activation, respectively. The in vivo efficacy evaluation including pharmacokinetic test, oral glucose tolerance test (OGTT), hypoglycemic duration test and chronic pharmacodynamics study in rodent animals were all carefully performed. KEY FINDINGS: Four XA peptides were synthesized with purity >99%. High binding affinity as well as activation potency of XA-4 for GLP-1R were demonstrated by SPR and cell-based luciferase reporter assay, respectively. Additionally, XA-4 exhibited the long-lasting antidiabetic effects in the multiple OGTTs, hypoglycemic duration test and chronic study in mice. Furthermore, combined treatment of XA-4 and double shRNA (D-shRNA) achieved potent antiviral effects in HSV-2 infected HEK293 cells. SIGNIFICANCE: XA-4 exhibited promising pharmaceutical potential to be a therapeutic drug for treating T2D, and also held potential to against the HSV-2 infection, which is really an accidental discovery. The strategy of recombinant XTENylation can also be applied to other peptides or small molecules for the development of long-acting therapeutic drugs.

Designing orodispersible films containing everolimus for enhanced compliance and bioavailability.

INTRODUCTION: Everolimus (EVR) has been approved for the treatment of various advanced cancers and its indications are increasingly expanding. Therefore, it is crucial for patients who have difficulty in swallowing, such as pediatric and elderly patients, to obtain a convenient formulation. The oral absorption of EVR is limited due to its low solubility in water, intestinal metabolism by CYP3A4 enzyme, P-gp-mediated efflux, and metabolism in the liver. The aim of this study was to develop a novel sublingual orodispersible film loading everolimus for improving patient compliance and enhancing oral bioavailability of EVR. RESEARCH DESIGN AND METHODS: Sublingual orodispersible films loading EVR were prepared by the solvent casting method and evaluated by in vitro and in vivo studies. RESULTS: The properties of films were determined by scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier-transform infrared spectrometry. The addition of acacia gum appeared to be crucial for protecting the drug from oxidation. Pharmacokinetic studies showed that loading into the sublingual orodispersible films significantly increased the oral bioavailability of EVR. CONCLUSION: The EVR-loaded sublingual orodispersible films are a promising, economical, and convenient approach for delivering EVR efficiently in a solid dosage form.

Dibromoacetic Acid Induced Hepatotoxicity in Mice through Oxidative Stress and Toll-Like Receptor 4 Signaling Pathway Activation.

Dibromoacetic acid (DBA) is one of haloacetic acids, often as a by-product of disinfection in drinking water. DBA is a multiple-organ carcinogen in rodent animals, but little research on its hepatotoxicity has been conducted and its mechanism has not been elucidated. In this study, we found that DBA could induce obvious hepatotoxcity in Balb/c mice as indicated by histological changes, increasing serum level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and accumulation of hepatic glycogen, after the mice were administered DBA at doses of 1.25, 5, and 20 mg/kg body weight for 28 days via oral gavage. In mechanism study, DBA induced oxidative stress as evidenced by increasing the level of malondialdehyde (MDA), reactive oxygen species (ROS) in the liver, advanced oxidative protein products (AOPPs) in the serum, and decreasing the level of glutathione (GSH) in the liver. DBA induced inflammation in the liver of the mice which is supported by increasing the production of tumor necrosis factor-α (TNF-α) and the mRNA levels of TNF-α, interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and nuclear factor κB (NF-κB) in the liver. DBA also upregulated the protein levels of Toll-like receptor (TLR) 4, myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF6), inhibitor of nuclear factor κB alpha (IκB-α), nuclear factor κB p65 (NF-κB p65), and the phosphoralation of P38 mitogen-activated protein kinase (P38MAPK) and c-Jun N-terminal kinase (JNK). Conclusion. DBA could induce hepatotoxicity in mice by oral exposure; the mechanism is related to oxidative stress, inflammation, and Toll-like receptor 4 signaling pathway activation.

Dibromoacetic acid induced Cl.Ly1+2/-9 T-cell apoptosis and activation of MAPKs signaling cascades.

Dibromoacetic acid (DBA), a haloacetic acid by-product of disinfection of drinking water, can cause many adverse effects in test animals, including immunotoxicity. However, the underlying molecular mechanism for the immunomodulatory effects remains unclear. The present study was undertaken to help in defining some potential mechanisms for this type of toxicity. Here, Cl.Ly1+2/-9 T-cells were exposed to varying levels of DBA and then several parameters, including cell survival, apoptosis, changes in mitochondrial potentials, and effects on select kinases (i.e., p38, ERK1/2, JNK1/2) were examined. The data showed that DBA significantly decreased Cl.Ly1+2/-9 cell viability in a dose-related manner. DBA also induced apoptosis, a decrease in mitochondrial trans-membrane potential, and up-regulated the protein expression of cleaved caspase-3. Moreover, DBA increased the phosphorylation of all three mitogen-activated protein kinases (MAPKs) evaluated. Pre-treatment with specific p38, ERK1/2, and JNK1/2 inhibitors (SB203580, U0126, SP600125, respectively) attenuated the inducible phosphorylation events. DBA also induced up-regulation of mRNA levels of the MAPKs downstream transcription factors ATF-2 and Elk-1. When taken together, the results suggest that DBA could induce murine Cl.Ly1+2/-9 T-cells apoptosis through mitochondria-dependent way, and activate the MAPKs pathways and downstream transcription factors ATF-2 and Elk-1.

The toxic influence of dibromoacetic acid on the hippocampus and pre-frontal cortex of rat: involvement of neuroinflammation response and oxidative stress.

Dibromoacetic acid (DBA) exsits in drinking water as a by-product of disinfection as a result of chlorination or ozonation processes. Hippocampus and pre-frontal cortex are the key structures in memory formation and weanling babies are more sensitive to environmental toxicant than adults, so this study was conducted to evaluate the potential neurotoxicity effects of DBA exposure when administered intragastrically for 4 weeks to weanling Sprague-Dawley rats, at concentration of 0, 20, 50, 125 mg/kg via the neurobehavioral and neurochemical effects. Results indicated that animals weight gain and food consumption were not significantly affected by DBA. However, morris water maze test showed varying degrees of changes between control and high-dose group. Additionally, the level of malondialdehyde (MDA) and generation of reactive oxygen species (ROS) in the hippocampus and pre-frontal cortex of rats increased significantly. The activities of total superoxide dismutase (SOD) and the glutathione (GSH) content in the hippocampus and pre-frontal cortex of rats decreased significantly after treatment with DBA. Treatment with DBA increased the protein and mRNA expression of Iba-1, NF-κB, TNF-α, IL-6, IL-1ß and HO-1 in the hippocampus and pre-frontal cortex of rats. These data suggested that DBA had a toxic influence on the hippocampus and pre-frontal cortex of rats, and that the mechanism of toxicity might be associated with the neuroinflammation response and oxidative stress.

DBA-induced caspase-3-dependent apoptosis occurs through mitochondrial translocation of cyt-c in the rat hippocampus.

Dibromoacetic acid (DBA), a by-product of disinfection, develops in drinking water during chlorination or ozonation processes. Water intake is the main source of DBA exposure in humans, which is potentially neurotoxic. The present study investigated the neurotoxic effects of DBA by assessing the behavioral and biochemical characteristics of Sprague Dawley rats intragastrically treated with DBA at concentrations of 20, 50 and 125 mg kg-1 body weight for 28 consecutive days. The results indicated that animal weight gain and food consumption were not significantly affected by DBA. However, shuttle box tests showed increases in mistake frequency and reaction latency between the control and high-dose group. We found significant changes in hippocampal neurons by histomorphological observation. Additionally, biochemical analysis indicated enhanced production of reactive oxygen species (ROS) resulting in disruption of cellular antioxidant defense systems including decreased mitochondrial superoxide dismutase (SOD) activity and release of cytochrome c (cyt-c) from mitochondria into the cytosol, which can induce neuronal apoptosis. Furthermore, the increase of cyt-c in the cytosol enhanced caspase-3 and caspase-9 activity, which was confirmed by poly ADP-ribose polymerase-1 (PARP-1) cleavage to its signature fragment of 85 kDa and decreased levels of protein kinase C-δ (PKC-δ) in the hippocampus. Meanwhile, DBA treatment caused differential modulation of apoptosis-associated proteins and mRNAs for phosphorylated apoptosis signal regulating kinase 1 (p-ASK-1), phosphorylated c-jun N-terminal kinase (p-JNK), cyt-c, Bax, Bcl-2, caspase-9 and cleaved caspase-3 accompanied by DNA damage. Taken together, these data indicate that DBA may induce neurotoxicity via caspase-3-dependent apoptosis involving mitochondrial translocation of cyt-c in the rat hippocampus.

In vitro evaluation of ruthenium complexes for photodynamic therapy.

BACKGROUND: Photodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated. METHODS: Photocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed. RESULTS: Rup-03 and Rup-04 had the lowest IC50 values. Rup-03 had an IC50 value of 29.5±2.3µM in HepG2 cells and 59.0±6.1µM in RAW264.7 cells, while Rup-04 had an IC50 value of 40.0±3.8µM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells. CONCLUSIONS: Among six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03.

The effects of icariin on the expression of HIF-1α, HSP-60 and HSP-70 in PC12 cells suffered from oxygen-glucose deprivation-induced injury.

CONTEXT: The effects of icariin, a chief constituent of flavonoids from Epimedium brevicornum Maxim (Berberidaceae), on the levels of HIF-1α, HSP-60 and HSP-70 remain unknown. OBJECTIVE: To explore the effects of icariin on the levels of HSP-60, HIF-1α and HSP-70 neuron-specific enolase (NSE) and cell viability. MATERIALS AND METHODS: PC12 cells were treated with icariin (10-7, 10-6 or 10-5 mol/L) for 3 h (1 h before oxygen-glucose deprivation (OGD) plus 2 h OGD). HSP-60, HIF-1α, HSP-70 and NSE were measured using enzyme-linked immunosorbent assay (ELISA). Cell viability was determined by metabolic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: After 2 h OGD, levels of HIF-1α, HSP-60, HSP-70 and NSE were increased significantly (HIF-1α: 33.3 ± 1.9 ng/L, HSP-60: 199 ± 16 ng/L, HSP-70: 195 ± 17 ng/L, NSE: 1487 ± 125 ng/L), and cell viability was significantly decreased (0.26 ± 0.03), while icariin (10-7, 10-6, or 10-5 mol/L) significantly reduced the contents of HIF-1α, HSP-60, HSP-70 and NSE (HIF-1α: 14.1 ± 1.4, 22.6 ± 1.8, 15.7 ± 2.1, HSP-60: 100 ± 12, 89 ± 6, 113 ± 11, HSP-70: 139 ± 9, 118 ± 7, 95 ± 9 and NSE: 1121 ± 80, 1019 ± 52, 731 ± 88), and improved cell viability (0.36 ± 0.03, 0.38 ± 0.04, 0.37 ± 0.03) in OGD-treated PC12 cells. DISCUSSION AND CONCLUSION: These results indicate that the protective mechanisms of icariin against OGD-induced injury may be related to down-regulating the expression of HIF-1α, HSP-60 and HSP-70.

miR-520e regulates cell proliferation, apoptosis and migration in breast cancer.

Previous studies have indicated that the deregulation of microRNAs contributes to tumorigenesis. Misregulation of microRNA-520e (miR-520e) has been observed in various types of cancer. However, the expression profile and biological function of miR-520e in breast cancer remains largely unknown. The present study demonstrated that miR-520e expression was significantly increased in breast cancer tissues compared with adjacent non-cancerous breast tissues in 21 patients, as revealed by reverse transcription-quantitative polymerase chain reaction. Furthermore, the proliferation capacity of breast cancer cells was markedly enhanced by the introduction of miR-520e in vitro using a cell counting kit-8 assay. The present study also revealed that the overexpression of miR-520e could suppress breast cancer cell apoptosis, revealed using Annexin V/propidium iodide double staining and flow cytometry analysis. In addition, the ectopic expression of miR-520e promoted the migration of breast cancer cells in vitro, as demonstrated by a Transwell assay. Overall, the findings of the present study highlight an important role for miR-520e in breast cancer development and in the molecular etiology of breast cancer, which indicates the potential application of miR-520e in cancer therapy.

Oral Exposure to Atrazine Induces Oxidative Stress and Calcium Homeostasis Disruption in Spleen of Mice.

The widely used herbicide atrazine (ATR) can cause many adverse effects including immunotoxicity, but the underlying mechanisms are not fully understood. The current study investigated the role of oxidative stress and calcium homeostasis in ATR-induced immunotoxicity in mice. ATR at doses of 0, 100, 200, or 400 mg/kg body weight was administered to Balb/c mice daily for 21 days by oral gavage. The studies performed 24 hr after the final exposure showed that ATR could induce the generation of reactive oxygen species in the spleen of the mice, increase the level of advanced oxidation protein product (AOPP) in the host serum, and cause the depletion of reduced glutathione in the serum, each in a dose-related manner. In addition, DNA damage was observed in isolated splenocytes as evidenced by increase in DNA comet tail formation. ATR exposure also caused increases in intracellular Ca2+ within splenocytes. Moreover, ATR treatment led to increased expression of genes for some antioxidant enzymes, such as HO-1 and Gpx1, as well as increased expression of NF-κB and Ref-1 proteins in the spleen. In conclusion, it appears that oxidative stress and disruptions in calcium homeostasis might play an important role in the induction of immunotoxicity in mice by ATR.

Dibromoacetic Acid Induces Thymocyte Apoptosis by Blocking Cell Cycle Progression, Increasing Intracellular Calcium, and the Fas/FasL Pathway in Vitro.

Dibromoacetic acid (DBAA), a haloacetic acid found in drinking water as a disinfection by-product, can cause many adverse effects, including immunotoxicity. In a previous study, we confirmed that DBAA can induce obvious immunotoxicity in mice but that the underlying mechanisms are not clearly understood. In our current study, we confirmed that DBAA induced cytotoxicity and apoptosis in thymocytes isolated from mice by a range of DBAA concentrations (0, 5, 10, 20, or 40 µM). The data showed that DBAA exposure led to a significant decrease in proliferative responses to T-cell mitogens and obvious inhibition in the production of cytokines interleukin-2 and interleukin-4. We found obvious morphological changes of apoptosis in thymocytes and observed the percentage of apoptotic thymocytes to increase significantly as the DBAA concentration increased. Further investigation showed that DBAA can cause G0/G1 arrest in cell cycle analysis, increase intracellular calcium ([Ca(2+)]i) levels, increase the expression of Fas/FasL proteins, and decrease the expression of Bcl-2 protein. It is concluded that in vitro exposure to DBAA can lead to marked cytotoxicity and apoptosis among thymocytes, and the mechanism involved is strongly related to blocking cell cycle progression, increasing intracellular calcium, and increasing Fas/FasL expressions.

A bivalent recombinant immunotoxin with high potency against tumors with EGFR and EGFRvIII expression.

EGFR and EGFRvIII are overexpressed in various types of cancer, serving as optimal targets for cancer therapy. Capitalizing on the high specificity of humanized antibody 806 (mAb806) to the EGFR and EGFRvIII overexpressed in cancer, we designed and generated a bivalent recombinant immunotoxin (RIT, DT390-BiscFv806) by fusing the mAb806-derived bivalent single-chain variable fragment with a diphtheria toxin fragment, DT390. In vitro, DT390-BiscFv806 efficiently internalized into the cells and exhibited high cytotoxicity against the U87 glioblastoma cells and the EGFRvIII-transfected U87 (U87-EGFRvIII) cells with a half maximal inhibition concentration (IC50) of 1.47 nM and 2.26 × 10(-4) nM, respectively. Notably, DT390-BiscFv806 was 4 orders of magnitude more potent against the U87-EGFRvIII cells than against the parent U87 cells. The cytotoxicity against a group of 6 head and neck squamous cell carcinoma cell lines were further analyzed, showing an IC50 ranging from 0.24 nM to 156 nM, depending on the expression level of EGFR/EGFRvIII. In animals, the U87-EGFRvIII tumor xenografts grew extremely faster than the parental U87, and systemic administration of DT390-BiscFv806 significantly inhibited the growth of established U87-EGFRvIII and U87 tumor xenografts, showing a growth inhibition rate of 76.3% (59.82-96.2%) and 59.4% (31.5-76.0%), respectively. In pathology, the RIT-treated tumors exhibited a low mitotic activity and a large number of degenerative tumor cells, compared with the control tumors. The results indicate that DT390-BiscFv806 is promising for treatment of various types of cancer, especially for those with high EGFR expression or with EGFR and EGFRvIII co-expression.

Drosophila ryanodine receptors mediate general anesthesia by halothane.

BACKGROUND: Although in vitro studies have identified numerous possible targets, the molecules that mediate the in vivo effects of volatile anesthetics remain largely unknown. The mammalian ryanodine receptor (Ryr) is a known halothane target, and the authors hypothesized that it has a central role in anesthesia. METHODS: Gene function of the Drosophila Ryr (dRyr) was manipulated in the whole body or in specific tissues using a collection of mutants and transgenes, and responses to halothane were measured with a reactive climbing assay. Cellular responses to halothane were studied using Ca imaging and patch clamp electrophysiology. RESULTS: Halothane potency strongly correlates with dRyr gene copy number, and missense mutations in regions known to be functionally important in the mammalian Ryrs gene cause dominant hypersensitivity. Tissue-specific manipulation of dRyr shows that expression in neurons and glia, but not muscle, mediates halothane sensitivity. In cultured cells, halothane-induced Ca efflux is strictly dRyr-dependent, suggesting a close interaction between halothane and dRyr. Ca imaging and electrophysiology of Drosophila central neurons reveal halothane-induced Ca flux that is altered in dRyr mutants and correlates with strong hyperpolarization. CONCLUSIONS: In Drosophila, neurally expressed dRyr mediates a substantial proportion of the anesthetic effects of halothane in vivo, is potently activated by halothane in vitro, and activates an inhibitory conductance. The authors' results provide support for Ryr as an important mediator of immobilization by volatile anesthetics.

[Transcriptional regulatory properties of DNA sequence upstream of the human ezrin gene promoter in nasopharyngeal carcinoma cells].

AIM: To investigate transcriptional regulatory properties of DNA sequence upstream of the ezrin gene promoter in nasopharyngeal carcinoma CNE2 cells. METHODS: A series of reporter gene expression vectors carrying ezrin-1541/-706 sequence were constructed. In forward or reverse orientation, the ezrin -1541/-706 segment was located upstream of the luc gene in pGL3-Basic, upstream of the ezrin promoter or SV40 promoter, or downstream of the luc gene controlled by ezrin promoter or SV40 promoter. These plasmids were transfected into CNE2 cells for luciferase assay. RESULTS: In CNE2 cells, when the ezrin -1541/-706 was located upstream of luc gene in pGL3-Basic in the forward orientation, it exhibited transcriptional activation about 50% of ezrin promoter; while this transactivation nearly abolished when this segment was reversed. When this segment was located upstream of the ezrin promoter or SV40 promoter in the forward orientation, it dramatically increased luciferase expression. However, the transcriptional enhancement disappeared when this segment was located upstream of promoters in the reverse orientation, or downstream of reporter genes in the forward or reverse orientation. CONCLUSION: In CNE2 cells, the DNA sequence upstream of the ezrin promoter could exhibit transcriptional activation and enhancement, in a position- and orientation-dependent manner.