Nrf2/ASPM axis regulated vasculogenic mimicry formation in hepatocellular carcinoma under hypoxia.

BACKGROUND: Hypoxic microenvironment is a common feature of most solid tumors including hepatocellular carcinoma (HCC). Vasculogenic mimicry (VM) formation by tumor cells could provide blood supply to tumor cells under hypoxia. NFE2 like basic leucine zipper (bZIP) transcription factor 2 (Nrf2), a regulator of cellular homeostasis, may promote tumor progression in the hypoxic conditions. However, the role and regulatory mechanisms of Nrf2 in HCC are not fully elucidated. METHODS: Nrf2 and assembly factor for spindle microtubules (ASPM) expression modulations were conducted by lentiviral transfections. Western blot, immunofluorescence, ChIP-qPCR, dual-luciferase reporter gene assay, flow cytometry, RNA sequencing, multiple bioinformatics databases analysis, cell function assays in vitro, mouse model in vivo and human HCC tissues were employed to assess the effect of Nrf2/ASPM axis on HCC progression under hypoxia. RESULTS: Nrf2 and ASPM expression facilitated epithelial-mesenchymal transition (EMT), cancer stem cells (CSCs) feature, and VM formation of HCC cells under hypoxia. Furthermore, Nrf2-regulated ASPM expression, via binding directly to the promoter region of ASPM and transcriptionally promoting ASPM expression. ASPM re-expression in Nrf2 knockdown cells or ASPM knockdown in Nrf2 overexpression cells reversed the cellular function caused by Nrf2. Meantime, retinol metabolism pathway was disrupted following abnormal ASPM expression. Nrf2/ASPM axis in murine models accelerated tumor growth and VM, corroborating in vitro findings. All-trans retinoic acid treatment reversed stemness and VM of HCC cells in vitro and in vivo. Clinically, Nrf2 and ASPM expressions were related to poor prognosis of HCC patients. CONCLUSIONS: Nrf2 drives EMT, CSCs characteristics and VM in HCC under hypoxia through the modulation of ASPM. Retinol metabolism pathway was dysregulated in HCC cells with ASPM overexpression. Nrf2/ASPM axis and related pathway provided potential therapeutic target for HCC.

Superconductivity in pressurized trilayer La4Ni3O10-δ single crystals.

The pursuit of discovering new high-temperature superconductors that diverge from the copper-based model1-3 has profound implications for explaining mechanisms behind superconductivity and may also enable new applications4-8. Here our investigation shows that the application of pressure effectively suppresses the spin-charge order in trilayer nickelate La4Ni3O10-δ single crystals, leading to the emergence of superconductivity with a maximum critical temperature (Tc) of around 30 K at 69.0 GPa. The d.c. susceptibility measurements confirm a substantial diamagnetic response below Tc, indicating the presence of bulk superconductivity with a volume fraction exceeding 80%. In the normal state, we observe a strange metal behaviour, characterized by a linear temperature-dependent resistance extending up to 300 K. Furthermore, the layer-dependent superconductivity observed hints at a unique interlayer coupling mechanism specific to nickelates, setting them apart from cuprates in this regard. Our findings provide crucial insights into the fundamental mechanisms underpinning superconductivity, while also introducing a new material platform to explore the intricate interplay between the spin-charge order, flat band structures, interlayer coupling, strange metal behaviour and high-temperature superconductivity.

Desmoglein 2 and desmocollin 2 depletions promote malignancy through distinct mechanisms in triple-negative and luminal breast cancer.

BACKGROUND: Aberrant expressions of desmoglein 2 (Dsg2) and desmocollin 2(Dsc2), the two most widely distributed desmosomal cadherins, have been found to play various roles in cancer in a context-dependent manner. Their specific roles on breast cancer (BC) and the potential mechanisms remain unclear. METHODS: The expressions of Dsg2 and Dsc2 in human BC tissues and cell lines were assessed by using bioinformatics analysis, immunohistochemistry and western blotting assays. Wound-healing and Transwell assays were performed to evaluate the cells' migration and invasion abilities. Plate colony-forming and MTT assays were used to examine the cells' capacity of proliferation. Mechanically, Dsg2 and Dsc2 knockdown-induced malignant behaviors were elucidated using western blotting assay as well as three inhibitors including MK2206 for AKT, PD98059 for ERK, and XAV-939 for ß-catenin. RESULTS: We found reduced expressions of Dsg2 and Dsc2 in human BC tissues and cell lines compared to normal counterparts. Furthermore, shRNA-mediated downregulation of Dsg2 and Dsc2 could significantly enhance cell proliferation, migration and invasion in triple-negative MDA-MB-231 and luminal MCF-7 BC cells. Mechanistically, EGFR activity was decreased but downstream AKT and ERK pathways were both activated maybe through other activated protein tyrosine kinases in shDsg2 and shDsc2 MDA-MB-231 cells since protein tyrosine kinases are key drivers of triple-negative BC survival. Additionally, AKT inhibitor treatment displayed much stronger capacity to abolish shDsg2 and shDsc2 induced progression compared to ERK inhibition, which was due to feedback activation of AKT pathway induced by ERK inhibition. In contrast, all of EGFR, AKT and ERK activities were attenuated, whereas ß-catenin was accumulated in shDsg2 and shDsc2 MCF-7 cells. These results indicate that EGFR-targeted therapy is not a good choice for BC patients with low Dsg2 or Dsc2 expression. Comparatively, AKT inhibitors may be more helpful to triple-negative BC patients with low Dsg2 or Dsc2 expression, while therapies targeting ß-catenin can be considered for luminal BC patients with low Dsg2 or Dsc2 expression. CONCLUSION: Our finding demonstrate that single knockdown of Dsg2 or Dsc2 could promote proliferation, motility and invasion in triple-negative MDA-MB-231 and luminal MCF-7 cells. Nevertheless, the underlying mechanisms were cellular context-specific and distinct.

RIPK1-dependent necroptosis promotes vasculogenic mimicry formation via eIF4E in triple-negative breast cancer.

Necroptosis is a caspase-independent form of programmed cell death. Receptor interacting protein kinase 1 (RIPK1) is a key molecule in the initiation of necroptosis and the formation of the necrotic complex. Vasculogenic mimicry (VM) provides a blood supply to tumor cells that is not dependent on endothelial cells. However, the relationship between necroptosis and VM in triple-negative breast cancer (TNBC) is not fully understood. In this study, we found that RIPK1-dependent necroptosis promoted VM formation in TNBC. Knockdown of RIPK1 significantly suppressed the number of necroptotic cells and VM formation. Moreover, RIPK1 activated the p-AKT/eIF4E signaling pathway during necroptosis in TNBC. eIF4E was blocked by knockdown of RIPK1 or AKT inhibitors. Furthermore, we found that eIF4E promoted VM formation by promoting epithelial-mesenchymal transition (EMT) and the expression and activity of MMP2. In addition to its critical role in necroptosis-mediated VM, eIF4E was essential for VM formation. Knockdown of eIF4E significantly suppressed VM formation during necroptosis. Finally, through clinical significance, the results found that eIF4E expression in TNBC was positively correlated with the mesenchymal marker vimentin, the VM marker MMP2, and the necroptosis markers MLKL and AKT. In conclusion, RIPK1-dependent necroptosis promotes VM formation in TNBC. Necroptosis promotes VM formation by activating RIPK1/p-AKT/eIF4E signaling in TNBC. eIF4E promotes EMT and MMP2 expression and activity, leading to VM formation. Our study provides a rationale for necroptosis-mediated VM and also providing a potential therapeutic target for TNBC.

MOF-derived ruthenium-doped amorphous molybdenum dioxide hybrid for highly efficient hydrogen evolution reaction in alkaline media.

Ruthenium-doped amorphous molybdenum dioxide coupled with a reduced graphene oxide hybrid (Ru-MoO2@PC/rGO) is synthesized using polyoxometalate-based MOFs/GO as a precursor. Benefitting from the synergistic effect of numerous exposed active sites, Ru dopants and the introduction of GO, the designed catalyst shows exceptional electrocatalytic performance toward the HER in alkaline media.

[Expression and Clinical Significance of Progesterone and Adiponectin Receptor Family Member 3 in Lung Cancer].

BACKGROUND: Progesterone and adiponectin receptor family member 3 (PAQR3) is a recently discovered tumor suppressor gene, which affects the development of a tumor by inhibiting cell proliferation, cell malignant transformation, angiogenesis, and tumor metastasis. This study investigates the expression of PAQR3 in lung cancer and its clinical significance. METHODS: A total of 106 patients with lung cancer received surgical treatment in hospital, and adjacent normal tissues of these patients were utilized as control group. The diagnosis of all patients was confirmed through clinical pathology. The expression of PAQR3 protein was detected by immunohistochemistry in lung cancer and adjacent normal tissues. The clinical significance of its expression was also investigated. RESULTS: The positive expression rate of PAQR3 protein in lung cancer was lower than that in adjacent normal tissues (P<0.01). The positive expression rate of PAQR3 protein was unrelated to age, tumor size, and gender, but it exhibited a significant relationship with the pathological type and differentiation, TNM staging, and lymph node metastasis (P<0.05). Kaplan-Meier survival analysis showed that the five-year survival rate of patients with PAQR3 protein positive expression was higher than that in patients with negative expression (P=0.026). CONCLUSIONS: The expression of PAQR3 protein significantly decreased in lung cancer, indicating that PAQR3 protein plays an important role in the pathogenesis of PAQR3 in lung cancer.

Improved Survival and Neurological Outcomes after Cardiopulmonary Resuscitation in Toll-like Receptor 4-mutant Mice.

BACKGROUND: Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system and noninfectious immune responses. It has been reported that TLR4 participates in the pathological course of ischemia/reperfusion (I/R) injury. However, the role of TLR4 in the process of I/R injury after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) is still unknown. In this study, we investigated the effects of TLR4 mutation on survival and neurological outcome in a mouse model of CA/CPR. METHODS: A model of potassium-induced CA was performed on TLR4-mutant mice (C3H/HeJ) and wild-type mice (C3H/HeN). After 3 min of untreated CA, resuscitation was attempted with chest compression, ventilation, and intravenous epinephrine. Behavioral tests were performed on mice on day 3 after CPR. The morphological changes in hippocampal neurons were assessed by light and electron microscopy. Expressions of TLR4 and intercellular adhesion molecule-1 (ICAM-1) were detected by Western blot. Levels of tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO) were measured with enzyme-linked immunosorbent assay (ELISA). RESULTS: On day 3 after resuscitation the overall mortality was 33.33% in C3H/HeJ group compared with 53.33% in C3H/HeN group (P < 0.05). And there was much higher central tendency in C3H/HeJ group than C3H/HeN group during open field test (P < 0.05). Meanwhile, the percentage of nonviable neurons was 21.16% in C3H/HeJ group compared with 53.11% in C3H/HeN group (P < 0.05). And there were significantly lower levels of hippocampal TNF-α and MPO in C3H/HeJ mice (TNF-α: 6.85±1.19 ng/mL, MPO: 0.33±0.11 U/g) than C3H/HeN mice (TNF-α: 11.36±2.12 ng/mL, MPO: 0.54±0.17 U/g) (all P < 0.01). CPR also significantly increased the expressions of TLR4 and ICAM-1 in C3H/HeN group. However, the expression of ICAM-1 was much lower in C3H/HeJ group than in C3H/HeN group after CPR (P < 0.01). CONCLUSION: TLR4 signaling is involved in brain damage and in inflammation triggered by CA/CPR.

Association of Genetic Polymorphisms in CDH1 and CTNNB1 with Breast Cancer Susceptibility and Patients' Prognosis among Chinese Han Women.

This study aims to investigate whether the germline variants in CDH1 and CTNNB1 would affect breast cancer susceptibility and patients' prognosis among Chinese Han women using a haplotype-based association analysis. We genotyped 12 haplotype-tagging single nucleotide polymorphisms (htSNPs) in CDH1 and CTNNB1 among 1,160 BC cases and 1,336 age-matched cancer-free controls using the TaqMan® Genotyping Assay. For association analyses of germline variants with breast cancer susceptibility, the results showed that rs7200690, rs7198799, rs17715799, rs13689 and diplotype CGC/TGC (rs7200690 + rs12185157 + rs7198799) in CDH1 as well as rs2293303 in CTNNB1 were associated with increased breast cancer risk. In addition, the Generalized Multifactor Dimensionality Reduction (GMDR) and logistic regression analysis predicted an interaction on breast cancer risk between rs17715799 and rs13689 as well as rs13689 and menarche-FFTP (First Full-Term Pregnancy) interval. For survival analyses, the results demonstrated that the minor allele homozygotes of rs13689 and haplotype TGC in CDH1 were linked with unfavorable event-free survival of breast cancer, whereas, rs4783689 of CDH1 showed the opposite effect under dominant model. Notably, the stratified analysis revealed that rs7186053 was associated with favorable event-free survival among patients with estrogen receptor (ER)-positive, progesterone receptor (PR)-positive or lymph node metastasis negative patients. Moreover, rs7200690 and rs7198799 in CDH1 as well as rs4533622 in CTNNB1 were associated with worse event-free survival among patients with clinical stage 0-I tumors. This study indicated that the genetic polymorphisms of CDH1 and CTNNB1 were associated with breast cancer susceptibility and patients' prognosis.

Effect of SP-A/B in lipoic acid on acute paraquat poisoning.

BACKGROUND: This study was undertaken to observe the concentration of SP-A/B and the pulmonary surfactant in the lung tissue of rats with acute lung injury/acute respiratory distress syndrome caused by paraquat poisoning after the treatment of metabolic antioxidant-lipoic acid and whether its influence was related to TNF-α. METHODS: Sixty-six male Sprage-Dawley rats were randomly divided into three groups: normal control group (NS group), 6 rats; paraquat poisoning group (PQ group), 30 rats; and paraquat+lipoic acid treatment group (LA group), 30 rats. The rats in the PQ and LA groups were subdivided into 3-, 6-, 12-, 24-, 48-hour subgroups, with 6 rats in each group. After the rats were sacrificed, lung tissue from the same part was taken from the rats. After HE staining, histological changes were observed in the tissue under a light microscope. Lung tissue was also taken to test the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Whole blood (0.8 mL) without anticoagulant was drawn from the tail vein of rats for the determination of the TNF-α level. The total RNA of the lung tissue was collected, and the Rt-PCR method was used to measure the levels of SP-A and SP-B mRNA. RESULTS: HE staining showed that histopathological changes were milder in the LA group than in the PQ group. There were significant differences in MDA and SOD levels between different intervals both in intergroups and intragroups except the 3-hour subgroup (P<0.01). Likewise, the significant differences in the levels of TNF-α were also present between the three groups and between different intervals (P<0.01). The significant differences in SP-A mRNA and SP-B mRNA amplification ratio were seen between the three groups at the same intervals (P<0.01), but the differences between different intervals in the PQ group were statistically significant (P<0.05). The differences between different intervals in the LA group were statistically significant (P<0.01). CONCLUSION: Lipoic acid in acute paraquat poisoning could diminish lung tissue damage by regulating directly tumor necrosis factor and indirectly the content of pulmonary surfactant so as to reduce pulmonary edema, improve lung compliance, and finally protect lung tissues.

Genetic polymorphisms in AURKA, BRCA1, CCNE1 and CDK2 are associated with ovarian cancer susceptibility among Chinese Han women.

INTRODUCTION: Centrosome aberrations and cell-cycle deregulation have important implications for ovarian cancer development. The AURKA, BRCA1, CCNE1 and CDK2 genes play pivotal roles in centrosome duplication and cell-cycle regulation. METHODS: Using a haplotype-based analysis, this study aimed to investigate whether genetic polymorphisms in these four genes may contribute to ovarian cancer susceptibility. A total of 22 single nucleotide polymorphisms (SNPs) in these four genes were genotyped in 287 cases of ovarian serous cystadenocarcinomas and 618 age-matched cancer-free controls from the Chinese Han population, and then haplotype blocks were reconstructed according to our genotyping data and linkage disequilibrium (LD) status of these SNPs. RESULTS: For AURKA, we found that haplotype GA [rs6064391 (T→G)+rs911162 (G→A)] was strongly associated with decreased ovarian cancer risk (adjusted OR=0.31, 95% CI=0.15-0.63, P=0.0012). For BRCA1, we found that haplotype CGTAG was associated with decreased ovarian cancer risk (adjusted OR=0.64, 95% CI=0.41-0.98, P=0.0417). Moreover, women harboring homozygous GA/CGTAG haplotypes showed the lowest risk (OR=0.12, 95% CI=0.02-0.94, P=0.0438). In CCNE1, the SNPs rs3218035 and rs3218042 were significantly associated with increased ovarian cancer risk (rs3218035: adjusted OR=5.20, 95% CI=1.85-14.52, P=0.0017; rs3218042: adjusted OR=4.98, 95% CI=1.75-14.19, P=0.0027). For CDK2, no significant association was found. CONCLUSIONS: This study indicates that genetic polymorphisms of AURKA, BRCA1 and CCNE1 may affect ovarian cancer susceptibility in Chinese Han women.

Upregulated expression of S100A8 in mice brain after focal cerebral ischemia reperfusion.

BACKGROUND: Recent studies have showed that S100A8 has been implicated in the pathobiology of inflammatory disorders, and that cerebral ischemia reperfusion (I/R) rapidly activates inflammation responses via Toll-like receptor 4 (TLR4). This study aimed to explore the expression of S100A8 and the relationship between S100A8 and TLR4 in focal cerebral ischemia reperfusion injury. METHODS: C3H/HeJ mice (n=30) and C3H/HeN mice (n=30) were divided randomly into a C3H/HeJ model group (n=18), a C3H/HeJ control group (n=12), a C3H/HeN model group (n=18), and a C3H/HeN control group (n=12). Middle cerebral artery I/R model in mice was produced using a thread embolism method. The brains of the mice were collected after ischemia for 1 hour and reperfusion for 12 hours. Stroke outcome was evaluated by determination of infarct volume and assessment of neurological impairment scores. Brain injury after cerebral I/R was observed by an optical microscope after TTC and HE dyeing. The immunofluorescence technique and real time PCR were used to test the expression level of S100A8 in brain damage. RESULTS: Compared with C3H/HeN mice, TLR4-deficient mice (C3H/HeJ) had lower infarct volumes and better outcomes in neurological tests. The levels of S100A8 increased sharply in the brains of mice after I/R injury. In addition, mice that lacked TLR4 (C3H/HeJ) had lower expression of I/R-induced S100A8 than C3H/HeN mice in the model group, indicating that a close relationship might exist between the levels of S100A8 and TLR4. CONCLUSION: S100A8 interaction with TLR4 might be involved in brain damage and in inflammation triggered by I/R injury.

Association study of germline variants in CCNB1 and CDK1 with breast cancer susceptibility, progression, and survival among Chinese Han women.

The CCNB1 and CDK1 genes encode the proteins of CyclinB1 and CDK1 respectively, which interact with each other and are involved in cell cycle regulation, centrosome duplication and chromosome segregation. This study aimed to investigate whether the genetic variants in these two genes may affect breast cancer (BC) susceptibility, progression, and survival in Chinese Han population using haplotype-based analysis. A total of ten tSNPs spanning from 2kb upstream to 2kb downstream of these genes were genotyped in 1204 cases and 1204 age-matched cancer-free controls. The haplotype blocks were determined according to our genotyping data and linkage disequilibrium (LD) status of these SNPs. For CCNB1, rs2069429 was significantly associated with increased BC susceptibility under recessive model (OR=2.352, 95%CI=1.480-3.737), so was the diplotype TAGT/TAGT (OR=1.947 95%CI=1.154-3.284, P=0.013). In addition, rs164390 was associated with Her2-negative BC. For CDK1, rs2448343 and rs1871446 were significantly associated with decreased BC risk under dominant models, so was the haplotype ATATT. These two SNPs also showed a dose-dependent effect on BC susceptibility. Using stratified association analysis, we found that women with the heterozygotes or minor allele homozygotes of rs2448343 had much less BC susceptibility among women with BMI<23. In CDK1, three closely located SNPs, rs2448343, rs3213048 and rs3213067, were significantly associated with tumor's PR status: the heterozygotes of rs2448343 were associated with PR-positive tumors, while the minor allele homozygotes of rs3213048 and heterozygotes of rs3213067 were associated with PR-negative BC tumors. In survival analysis, rs1871446 was associated with unfavorable event-free survival under recessive model, so was the CDK1 diplotype ATATG/ATATG, which carried the minor allele homozygote of rs1871446. Our study indicates that genetic polymorphisms of CCNB1 and CDK1 are related to BC susceptibility, progression, and survival in Chinese Han women. Further studies need to be performed in other populations as an independent replication to verify these results.

Association of germline variation in CCNE1 and CDK2 with breast cancer risk, progression and survival among Chinese Han women.

BACKGROUND: Somatic alterations of cyclin-dependent kinase 2 (CDK2)-cyclin E complex have been shown to contribute to breast cancer (BC) development and progression. This study aimed to explore the effects of single nucleotide polymorphisms (SNPs) in CDK2 and CCNE1 (a gene encoding G1/S specific cyclin E1 protein, formerly called cyclin E) on BC risk, progression and survival in a Chinese Han population. METHODOLOGY/PRINCIPAL FINDINGS: We herein genotyped 6 haplotype-tagging SNPs (htSNPs) of CCNE1 and 2 htSNPs of CDK2 in 1207 BC cases and 1207 age-matched controls among Chinese Han women, and then reconstructed haplotype blocks according to our genotyping data and linkage disequilibrium status of these htSNPs. For CCNE1, the minor allele homozygotes of three htSNPs were associated with BC risk (rs3218035: adjusted odds ratio [aOR] = 3.35, 95% confidence interval [CI] = 1.69-6.67; rs3218038: aOR = 1.81, 95% CI = 1.22-2.70; rs3218042: aOR = 2.64, 95% CI = 1.31-5.34), and these three loci showed a dose-dependent manner in increasing BC risk (P(trend) = 0.0001). Moreover, the 5-SNP haplotype CCGTC, which carried none of minor alleles of the 3 at-risk SNPs, was associated with a favorable event-free survival (hazard ratio [HR] = 0.53, 95% CI = 0.32-0.90). Stratified analysis suggested that the minor-allele homozygote carriers of rs3218038 had a worse event-free survival among patients with aggressive tumours (in tumour size>2 cm group: HR = 2.06, 95% CI = 1.06-3.99; in positive lymph node metastasis group: HR = 2.41, 95% CI = 1.15-5.03; in stage II-IV group: HR = 2.03, 95% CI = 1.09-3.79). For CDK2, no significant association was found. CONCLUSIONS/SIGNIFICANCE: This study indicates that genetic variants in CCNE1 may contribute to BC risk and survival in Chinese Han population. They may become molecular markers for individual evaluation of BC susceptibility and prognosis. Nevertheless, further validation studies are needed.

Genetic polymorphisms in centrobin and Nek2 are associated with breast cancer susceptibility in a Chinese Han population.

Centrosome aberrations have been suggested to cause chromosomal instability and aneuploidy, and eventually promote cancer development. The Centrobin and Nek2 proteins interact with each other and both are involved in centrosome duplication and chromosome segregation. This study aimed to investigate whether genetic polymorphisms in these two genes may affect breast cancer susceptibility in Chinese Han population using a haplotype-based analysis. Five single nucleotide polymorphisms (SNPs) in centrobin and four SNPs in Nek2 were genotyped in 1,215 cases of infiltrating ductal breast cancer and 1,215 age-matched cancer-free controls from Chinese Han population. The results showed that CATCG haplotype of centrobin was strongly associated with decreased breast cancer risk (adjusted OR = 0.14, 95 % CI = 0.09-0.22), which was mainly driven by the C allele of SNP rs11650083 (A>C, located in exon 12, resulting in Pro578Gln). None of the individual SNPs in Nek2 was associated with breast cancer risk. However, haplotype GTAT of Nek2 was associated with increased risk of breast cancer (adjusted OR = 1.56, 95 % CI = 1.18-2.06) and its risk was significantly elevated among women with both family history of cancer and a longer menarche-first full-term pregnancy (FFTP) interval (>11 years) (adjusted OR = 5.31, 95 % CI = 1.97-14.32). Furthermore, women harboring both at-risk haplotype GTAT of Nek2 and protective haplotype CATCG of centrobin were linked with decreased breast cancer risk, suggesting that the association between genetic variants of Nek2 and increased breast cancer risk was modified by genetic variants of centrobin. Our results indicate that genetic polymorphisms of centrobin and Nek2 are related to breast cancer susceptibility in Chinese Han women.

Edaravone attenuates paraquat-induced lung injury by inhibiting oxidative stress in human type II alveolar epithelial cells.

BACKGROUND: Edaravone (3-methyl-1-penyl-2-pyrazolin-5-one) is a potent free-radical scavenger and has the antioxidant ability to inhibit lipid peroxidation. The study aimed to examine the effect of edaravone on protecting the acute injury of human type II alveolar epithelial cells (A549 cells) induced by paraquat (PQ) and the change of production of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD). METHODS: A549 cells were cultured and divided into PQ group (group P), edaravone-treated group (group E) and normal control group (group C). The cells in group P were exposed to paraquat (600 µmol/L), and the cells in group E were treated with edaravone (100 µmol/L) additionally, and no drug intervention was given to the cells in group C. Real-time monitoring by LSCM was used to detect the cell response and the intracellular dynamic change of ROS level in A549 cells after administration of PQ and edaravone. And the levels of SOD and MDA were detected respectively by biochemistry colorimetry. Data were expressed as mean ± standard error of the mean. Statistical analysis was carried out with the soft SPSS 16.0. RESULTS: The concentration of intracellular ROS significantly increased when PQ was given to A549 cells. But after administration of edaravone, the concentration of intracellular ROS was decreased. Compared to the PQ group, the levels of SOD in the edaravone group were significantly increased while the levels of MDA were markedly decreased. CONCLUSIONS: Paraquat can increase the oxidative stress, and induce the lipid peroxidation of A549 cells. Edaravone has the effect to scavenge reactive oxygen species, and to protect against the PQ-induced lung toxicity.

Genetic polymorphisms in AURKA and BRCA1 are associated with breast cancer susceptibility in a Chinese Han population.

Centrosome defects can result in aneuploidy and genomic instability, and have important implications for breast cancer development. The Aurora-A and BRCA1 proteins interact and both are strongly involved in centrosome regulation. Genetic variants in these two genes may have an effect on breast cancer development. Here, we report a comprehensive single nucleotide polymorphism (SNP) and haplotype-tagging association study on these two genes in 1334 breast cancer cases and 1568 unaffected controls among the Chinese Han population. Apart from a missense SNP, rs2273535 (Phe31Ile), and a probable risk SNP, rs2064863, six htSNPs were analysed in three high-LD blocks of AURKA spanning from 10 kb upstream to 2 kb downstream of AURKA. For BRCA1, six htSNPs were analysed in a large high-LD region covering 98 kb (10 kb was extended to each end of BRCA1). The results showed that four SNPs in AURKA (data in recessive model, rs2273535: OR = 2.19, 95% CI = 1.03-4.66, p = 0.0422; rs2298016: OR = 0.38, 95% CI = 0.18-0.82, p = 0.0141; rs6024836: OR = 1.54, 95% CI = 1.18-2.00, p = 0.0014; rs10485805: OR = 0.68, 95% CI = 0.47-0.98, p = 0.0380) and one SNP in BRCA1 (rs3737559, dominant model OR = 1.35, 95% CI = 1.11-1.64, p = 0.0030) were associated with breast cancer susceptibility. After correction for multiple comparisons (FDR = 0.05), only rs6024836 and rs3737559 remained significant. Two haplotypes (CC of block 2, OR = 20.74, 95% CI = 4.35-98.88, p = 0.0001; GG of block 3, OR = 1.32, 95% CI = 1.12-1.56, p = 0.0010) and one diplotype (AG-GG of block 3, OR = 1.63, 95% CI = 1.18-2.26, p = 0.0031) within AURKA showed strong associations with breast cancer risk. One haplotype of BRCA1 (CTGTTG, OR = 1.30, 95% CI = 1.06-1.59, p = 0.0118) was also associated with breast cancer risk. However, women harbouring both at-risk genotypes of Aurora-A and BRCA1 were at a slightly increased risk compared with those harbouring either at-risk variant alone. Common genetic variants in the AURKA and BRCA1 genes may contribute to breast cancer development.

TLR4 signaling induced TLR2 expression in the process of mimic cerebral ischemia/reperfusion in vitro.

Both TLR4 and TLR2 participated in the mediation of the inflammatory injury in the process of partial cerebral ischemia/reperfusion. However, it still remains unclear whether a crosstalk exists between TLR2 and TLR4 in ischemic cerebral damage. In the present study, we investigated the effect of TLR4 signaling on TLR2 expression during mimic cerebral I/R in vitro. BV-2 cells were cultured and treated with ischemia/reperfusion, then transfected with the plasmid pEGFP-H1/TLR4-siRNA, the plasmid pEGFP-H1/control sequence-siRNA and the blank plasmid, respectively. Interestingly, the expression of TLR2 and TLR4 mRNA and protein, NF-kappaB p65 mRNA and supernatant TNF-alpha level were significantly higher in ischemia/reperfusion treated cells than those lack of ischemia/reperfusion treatment, and as compared with those in ischemia/reperfusion treated cells without transfection, no significant differences about the above mentioned gene and protein expression were found in the blank plasmid tranfected cells and the plasmid pEGFP-H1/control sequence-siRNA transfected cells respectively, while the expression levels in the plasmid pEGFP-H1/TLR4-siRNA transfected cells were significantly lower. Additionally, in order to determine the effects of pyrrolidinediethyldithiocarbamate (PDTC), an NF-kappaB inhibitor, on the TLR4-induced TLR2 expression in BV-2 cells treated with ischemia/reperfusion, it was found that TLR4 and TLR2 mRNA expressions in PDTC pretreated cells were significantly lower in comparison with normal saline pretreated cells and non-pretreated cells. The data suggested that TLR2 activation, signaled by TLR4 and regulated by NF-kappaB, might be directly involved play an important role in ischemia/reperfusion induced brain damage.

The antidotal effects of high-dosage gamma-aminobutyric acid on acute tetramine poisoning as compared with sodium dimercaptopropane sulfonate.

To investigate the therapeutic effect of high-dosage gamma-aminobutyric acid (GABA) on acute tetramine (TET) poisoning, 50 Kunming mice were divided into 5 groups at random and the antidotal effects of GABA or sodium dimercaptopropane sulfonate (Na-DMPS) on poisoned mice in different groups were observed in order to compare the therapeutic effects of high-dosage GABA with those of Na-DMPS. Slices of brain tissue of the poisoned mice were made to examine pathological changes of cells. The survival analysis was employed. Our results showed that both high-dosage GABA and Na-DMPS could obviously prolong the survival time, delay onset of convulsion and muscular twitch, and ameliorate the symptoms after acute tetramine poisoning in the mice. Better effects could be achieved with earlier use of high dosage GABA or Na-DMPS. There was no significant difference in prolonging the survival time between high-dose GABA and Na-DMPS used immediately after poisioning. It is concluded that high-dosage GABA can effectively antagonize acute toxicity of teramine in mice. And it is suggested that high-dosage GABA may be used as an excellent antidote for acute TET poisoning in clinical practice. The indications and correct dosage for clinical use awaits to be further studied.