Lanthanum Chloride Induces Axon Abnormality Through LKB1-MARK2 and LKB1-STK25-GM130 Signaling Pathways.

Lanthanum (La) is a natural rare-earth element that can damage the central nervous system and impair learning and memory. However, its neurotoxic mechanism remains unclear. In this study, adult female rats were divided into 4 groups and given distilled water solution containing 0%, 0.125%, 0.25%, and 0.5% LaCl3, respectively, and this was done from conception to the end of the location. Their offspring rats were used to establish animal models to investigate LaCl3 neurotoxicity. Primary neurons cultured in vitro were treated with LaCl3 and infected with LKB1 overexpression lentivirus. The results showed that LaCl3 exposure resulted in abnormal axons in the hippocampus and primary cultured neurons. LaCl3 reduced the expression of LKB1, p-LKB1, STRAD and MO25 proteins, and directly or indirectly affected the expression of LKB1, leading to decreased activity of LKB1-MARK2 and LKB1-STK25-GM130 pathways. This study indicated that LaCl3 exposure could interfere with the normal effects of LKB1 in the brain and downregulate LKB1-MARK2 and LKB1-STK25-GM130 signaling pathways, resulting in abnormal axon in offspring rats.

Aluminum exposure induces central nervous system impairment via activating NLRP3-medicated pyroptosis pathway.

PURPOSE: Aluminum is an environmental toxicant whose long-term exposure is closely associated with nervous system impairment. This study mainly investigated neurological impairment induced by subchronic aluminum exposure via activating NLRP3-medicated pyroptosis pathway. METHODS: In vivo, Kunming mice were exposed to AlCl3 (30.3 mg/kg, 101 mg/kg and 303 mg/kg) via drinking water for 3 months, and administered with Rsv (100 mg/kg) by gavage for 1 month. Cognitive impairment was assessed by Morris water maze test, and pathological injury was detected via H&E staining. BBB integrity, pyroptosis and neuroinflammation were evaluated through western blotting and immunofluorescence methods. In vitro, BV2 microglia was treated with AlCl3 (0.5 mM, 1 mM and 2 mM) to sensitize pyroptosis pathway. The protein interaction was verified by co-immunoprecipitation, and neuronal damage was estimated via a conditioned medium co-culture system with BV2 and TH22 cells. RESULTS: Our results showed that AlCl3 induced mice memory disorder, BBB destruction, and pathological injury. Besides, aluminum caused glial activation, sensitized DDX3X-NLRP3 pyroptosis pathway, released cytokines IL-1ß and IL-18, initiating neuroinflammation. BV2 microglia treated with AlCl3 emerged hyperactivation and pyroptotic death, and Ddx3x knockdown inhibited pyroptosis signaling pathway. DDX3X acted as a live-or-die checkpoint in stressed cells by regulating NLRP3 inflammasome and G3BP1 stress granules. Furthermore, aluminum-activated microglia had an adverse effect on co-cultured neurons and destroyed nervous system homeostasis. CONCLUSION: Aluminum exposure could induce pyroptosis and neurotoxicity. DDX3X determined live or die via selectively regulating pro-survival stress granules or pro-death NLRP3 inflammasome. Excessive activation of microglia might damage neurons and aggravate nerve injury.

Bisphenol A and Di(2-Ethylhexyl) Phthalate promote pulmonary carcinoma in female rats via estrogen receptor beta: In vivo and in silico analysis.

The prevalence of lung cancer in women currently merits our attentions. However, cigarette exposure alone does not tell the whole story that lung cancer is more prevalent among non-smoking women. Since female lung cancer is closely linked to estrogen levels, many of endocrine disrupting chemicals (EDCs), as the substances similar to estrogen, affect hormone levels and become a potential risk of female lung cancer. Additionally, the combined toxicity of EDCs in daily environment has only been discussed on a limited scale. Consequently, this study explored the cancer-promoting effect of two representative substances of EDCs namely Bisphenol A (BPA) and Di(2-Ethylhexyl) Phthalate (DEHP) after their exposure alone or in combination, using a rat pulmonary tumor model published previously, combining bioinformatics analysis based on The Comparative Toxicogenomics Database (CTD) and The Cancer Genome Atlas (TCGA) databases. It demonstrated that BPA and DEHP enhanced the promotion of pulmonary tumor in female rats, either alone or in combination. Mechanistically, BPA and DEHP mainly directly bound and activated ESR2 protein, phosphorylated CREB protein, activated HDAC6 transcriptionally, induced the production of the proto-oncogene c-MYC, and accelerated the formation of pulmonary tumor in female rats. Remarkably, BPA, rather than DEHP, exhibited a much more critical effect in female lung cancer. Additionally, the transcription factor ESR2 was most affected in carcinogenesis, causing genetic disruption. Furthermore, the TCGA database revealed that ESR2 could enhance the promotion and progression of non-small cell lung cancer in females via activating the WNT/ß-catenin pathway. Finally, our findings demonstrated that BPA and DEHP could enhance the promotion of pulmonary carcinoma via ESR2 in female rats and provide a potential and valuable insight into the causes and prevention of lung cancer in non-smoking women due to EDCs exposure.

Aluminum induces neuroinflammation via P2X7 receptor activating NLRP3 inflammasome pathway.

INTRODUCTION: Aluminum is everywhere in nature and is a recognized neurotoxicant closely associated with various neurodegenerative diseases. Neuroinflammation occurs in the early stage of neurodegenerative diseases, but the underlying mechanism by which aluminum induces neuroinflammation remains unclear. MATERIAL AND METHODS: A 3-month subchronic aluminum exposure mouse model was established by drinking water containing aluminum chloride (AlCl3). Microglia BV2 cells and hippocampal neuron HT22 cells were treated with AlCl3 in vitro. BBG and YC-1 were used as intervention agents. RESULTS: Aluminum could activate microglia and increase the level of extracellular ATP, stimulate P2X7 receptor, HIF-1α, activate NLRP3 inflammasome and CASP-1, release more cytokine IL-1ß, and induce an inflammatory response in nerve cells. There was a mutual regulatory relationship between P2X7 and HIF-1α at mRNA and protein levels. The co-culture system of BV2-HT22 cells observed that conditioned medium from microglia treated with aluminum could aggravate neuronal morphological damage, inflammatory response and death. While BBG and YC-1 intervention could rescue these injuries to some extent. CONCLUSION: The P2X7-NLRP3 pathway was involved in aluminum-induced neuroinflammation and injury. P2X7 and HIF-1α might mutually regulate and promote the progression of neuroinflammation, both BBG and YC-1 could relieve it.

Cigarette smoke triggers calcium overload in mouse hippocampal neurons via the ΔFOSB-CACNA2D1 axis to impair cognitive performance.

A growing body of evidence shows that cigarette smoking impairs cognitive performance. The 'Calcium Hypothesis' theory of neuronopathies reveals a critical role of aberrant calcium signaling in compromised cognitive functions. However, the underlying implications of abnormalities in calcium signaling in the neurotoxicity induced by cigarette smoke (CS) have not yet been identified. CACNA2D1, an important auxiliary subunit involved in the composition of voltage-gated calcium channels (VGCCs), was reported to affect the calcium signaling in neurons by facilitating VGCCs-mediated Ca2+ influx. ΔFOSB, an alternatively-spliced product of the Fosb gene, is an activity-dependent transcription factor induced robustly in the brain in response to environmental stimuli such as CS. Interestingly, our preliminary bioinformatics analysis revealed a significant co-expression between ΔFOSB and CACNA2D1 in brain tissues of patients with neurodegenerative diseases characterized by progressive cognitive decline. Therefore, we hypothesized that the activation of the ΔFOSB-CACNA2D1 axis in response to CS exposure might cause dysregulation of calcium homeostasis in hippocampal neurons via VGCCs-mediated Ca2+ influx, thereby contributing to cognitive deficits. To this end, the present study established a CS-induced mouse model of hippocampus-dependent cognitive impairment, in which the activation of the ΔFOSB-CACNA2D1 axis accompanied by severe calcium overload was observed in the mouse hippocampal tissues. More importantly, ΔFOSB knockdown-/overexpression-mediated inactivation/activation of the ΔFOSB-CACNA2D1 axis interdicted/mimicked CS-induced dysregulation of calcium homeostasis followed by severe cellular damage in HT22 mouse hippocampal neurons. Mechanistically speaking, a further ChIP-qPCR assay confirmed the physical interaction between transcription factor ΔFOSB and the Cacna2d1 gene promoter, suggesting a direct transcriptional regulation of the Cacna2d1 gene by ΔFOSB. Overall, our current work aims to deliver a unique insight into the neurotoxic mechanisms induced by CS to explore potential targets for intervention.

Resveratrol alleviates aluminum-induced intestinal barrier dysfunction in mice.

BACKGROUND: Aluminum is mainly exposed to the general population through food and water, and is absorbed into the systemic circulation through intestine, which in turn damages the intestinal barrier. METHODS: The mice model of subchronic exposure to aluminum chloride (AlCl3 ) was established via oral. Tail suspension test was used to detect depressive behavior. H&E staining was performed to assess pathological intestinal injury. Intestinal permeability was estimated by exogenous Evans blue content. The level of inflammatory cytokines and tight junction protein were assessed via ELISA and western blotting. Simultaneously, resveratrol (Rsv, an agonist of Sirt1) was evaluated the protective role against intestinal barrier injuries caused by aluminum exposure. RESULTS: Our results showed that AlCl3 induced depressive-like behavior, intestinal pathological damage and intestinal barrier permeability, resulting in intestinal barrier dysfunction. Besides, aluminum induced the expression of inflammatory cytokines, which further triggered IRF8-MMP9-mediated downregulation of tight junction proteins including CLD1, OCLD and ZO-1. After Rsv treatment, SIRT1 expression was increased, depressive symptom was improved, pathological injury was reduced, inflammatory reaction was alleviated, and intestinal barrier function restored. CONCLUSION: Our findings revealed that aluminum exposure induced intestinal barrier dysfunction by IRF8-MMP9 signaling pathway. Rsv alleviated these injuries via activating SIRT1.

Benzo[a]pyrene diol epoxide-induced transformed cells identify the significance of hsa_circ_0051488, a ERCC1-derived circular RNA in pulmonary squamous cell carcinoma.

ERCC1 is a gene for repairing DNA damage whose function is related to carcinogenic-induced tumorigenesis and the effectiveness of platinum therapies. Circular RNAs (circRNAs) are products of posttranscriptional regulation with pleiotropic effects on the pathogenesis of lung cancer. We aim to identify that specific circRNAs derived from ERCC1 can regulate key biological processes involved in the development of lung cancer. We performed bioinformatics analysis, in vitro experiments, and analyzed clinical samples, to determine the biological features of a certain ERCC1-derived circRNA termed as hsa_circ_0051488 in benzo[a]pyrene diol epoxide-induced malignant transformed cell and lung cancer cell. The well-established model of transformed cells provided an ideal platform for analyzing the molecular characteristics of this circRNA in the malignant transformation of lung epithelial cell, which supports that hsa_circ_0051488 functions in the onset and growth of lung squamous cell carcinoma (LUSC). Further analysis indicates that the absence of hsa_circ_0051488 promoted the proliferation of cells with the malignant phenotype. Extensive experiments confirm that hsa_circ_0051488 is present in the cytoplasm and functioned as a competing endogenous RNA. In particular, hsa_circ_0051488 binds to mir-6717-5p, thereby modulating the expression of SATB2 gene, a lung cancer suppressor. Furthermore, our in silico experiments indicate that SATB2 can inhibit multiple tumor pathways and its expression positively correlated with the tumor suppressor gene CRMP1. These findings suggest a possible regulatory mechanism of hsa_circ_0051488 in LUSC, and that the newly discovered hsa_circ_0051488/miR-6717-5p/SATB2 axis may be a potential route for therapeutic intervention of LUSC.

Lanthanum Chloride Impairs Learning and Memory and Induces Dendritic Spine Abnormality by Down-Regulating Rac1/PAK Signaling Pathway in Hippocampus of Offspring Rats.

Lanthanum (La) is a natural rare earth element. It has neurotoxic effects which can impair learning and memory in humans. However, its mechanism of neurotoxicity is unclear. Learning and memory are coordinated by dendritic spines which form tiny protruding structures on the dendritic branches of neurons. This study investigated the effect of LaCl3 exposure to pregnant and lactating rats on the offspring rats' learning and memory ability. In this study, rats were divided into 4 groups and given distilled water solution containing 0%, 0.125%, 0.25%, 0.5% LaCl3, respectively, and this was done from conception to the end of the location. The effects of LaCl3 on spatial learning and memory ability in offspring rats and in the development of dendritic spines in CA1 pyramidal cells were investigated. The results showed that LaCl3 impaired spatial learning and memory ability in offspring rats, and decreased dendritic spine density during development. In addition, LaCl3 can affect the expression of CaMKII, miRNA132, p250GAP, Tiam1, PARD3, and down-regulated the activation of Rac1 which led to a decrease in the expression of Rac1/PAK signaling pathway and downstream regulatory proteins Cortactin and actin-related protein 2/3 complex (Arp2/3 complex). This study indicated that the learning and memory impairment and the decrease of dendritic spine density in the offspring of LaCl3 exposure may be related to the down-regulation of the Rac1/PAK signaling pathway regulated by Tiam1 and p250GAP.

Tension-Free Mesh Repair for Incarcerated Groin Hernia: A Comparative Study.

Background. Management of emergent groin hernias remains challenging, due to limited consensus in surgical approach and repair options (eg, mesh vs nonmesh, biological mesh, and polypropylene [PP] mesh). Methods. A 5-year retrospective study was conducted on 118 patients who received emergency incarcerated groin hernia repair in Beijing Chaoyang Hospital. The incidence of surgical site infection (SSI), preoperative mortality, sepsis, and ileus was noted. In the follow-up, postoperative foreign body sensation, chronic pain, seroma/hematoma, and recurrence were recorded. The outcomes of different surgical procedures (with mesh/without mesh, biological mesh/PP mesh, transabdominal preperitoneal (TAPP)/Lichtenstein repair) were compared and analyzed. Results. Out of the 118 patients, 14 cases received suture repair (as group A); 104 cases had TAPP repair (n = 44) or Lichtenstein repair (n = 60) with meshes, including 23 cases of biological mesh (as group B); and 81 cases had repair with PP mesh (group C). There were no significant differences between the 3 groups regarding SSI, mortality, sepsis, and ileus. After 20.5 months of follow-up (range from 6 to 65 months), 21.4% of group A developed recurrence, a rate significantly higher than that of group B (4.3%) and group C (0). The incidence of seroma/hematoma in group B was higher than that in group A (7.1%) and group C (7.4%). The results between TAPP group and Lichtenstein group were comparable. Conclusion. Tension-free mesh repair in the treatment of emergency incarcerated groin hernia is safe and effective, which can reduce hernia recurrence without increasing infection risk. The results of biological mesh and PP mesh were comparable.

Establishment of a Rabbit Model of Giant Abdominal Wall Hernia.

PURPOSE: Animal models play an important role in abdominal wall hernia research. However, there is still no standard animal models for abdominal wall hernia. This study aimed to introduce a novel rabbit model of giant abdominal wall hernia. METHODS: Sixteen 1-year-old New Zealand rabbits weighing 3 to 5 kg were used. After general anesthesia, a 5-cm longitudinal incision was made 2 cm lateral to the ventral midline, and a full-thickness laparotomy incision was made en bloc including the peritoneum (except skin). A full-thickness defect of the abdominal wall with a diameter of 3 cm was created. To increase the intraabdominal pressure, constipation was induced by deprivation of water perioperatively. The development of giant abdominal wall hernia was recorded. The bulge area of these rabbits was redissected to assess the hernia 3 months postoperatively. RESULTS: Of the 16 rabbits, 13 (81.25%) rabbits had grade I healing and 3 (18.75%) rabbits had grade III healing. Reversible abdominal bulge at the incisional site was observed in all rabbits 3 to 18 days postoperatively. The average maximum diameter of the bulge was 8.73 ± 1.00 cm. Redissection of the bulge area showed successful establishment of giant abdominal wall hernia. CONCLUSION: We successfully established a rabbit model of giant abdominal wall hernia, which may provide an easy-to-use tool for the research of abdominal wall hernia.

Epidemic Situation of Brucellosis in Jinzhou City of China and Prediction Using the ARIMA Model.

OBJECTIVE: This study aimed to investigate the specific epidemiological characteristics and epidemic situation of brucellosis in Jinzhou City of China so as to establish a suitable prediction model potentially applied as a decision-supportive tool for reasonably assigning health interventions and health delivery. METHODS: Monthly morbidity data from 2004 to 2013 were selected to construct the autoregressive integrated moving average (ARIMA) model using SPSS 13.0 software. Moreover, stability analysis and sequence tranquilization, model recognition, parameter test, and model diagnostic were also carried out. Finally, the fitting and prediction accuracy of the ARIMA model were evaluated using the monthly morbidity data in 2014. RESULTS: A total of 3078 cases affected by brucellosis were reported from January 1998 to December 2015 in Jinzhou City. The incidence of brucellosis had shown a fluctuating growth gradually. Moreover, the ARIMA(1,1,1)(0,1,1)12 model was finally selected among quite a few plausible ARIMA models based upon the parameter test, correlation analysis, and Box-Ljung test. Notably, the incidence from 2005 to 2014 forecasted using this ARIMA model fitted well with the actual incidence data. Notably, the actual morbidity in 2014 fell within the scope of 95% confidence limit of values predicted by the ARIMA(1,1,1)(0,1,1)12 model, with the absolute error between the predicted and the actual values in 2014 ranging from 0.02 to 0.74. Meanwhile, the MAPE was 19.83%. CONCLUSION: It is suitable to predict the incidence of brucellosis in Jinzhou City of China using the ARIMA(1,1,1)(0,1,1)12 model.

Lanthanum chloride reduces lactate production in primary culture rat cortical astrocytes and suppresses primary co-culture rat cortical astrocyte-neuron lactate transport.

Lanthanum (La) can impair learning memory and induce behavioral abnormalities in animals. However, the mechanism underlying these adverse effects of La is still elusive. It has been demonstrated that lactate derived from astrocytes is the major energy source for neurons during long-term memory (LTM) formation and the deficiency of lactate supply can result in LTM damage. However, little work has been done with respect to the impact of La on the lactate production in astrocytes and astrocyte-neuron lactate transport (ANLT). Herein, experiments were undertaken to explore if there was such an adverse effect of La. Primary culture rat cortical astrocytes and primary co-culture rat cortical astrocyte-neuron were treated with (0.125, 0.25 and 0.5 mM) lanthanum chloride (LaCl3) for 24 h. The results showed that LaCl3 treatment significantly downregulated the mRNA and protein expression of glucose transporter 1 (GLUT1), glycogen synthase (GS), glycogen phosphorylase (GP), lactate dehydrogenase A (LDHA), and monocarboxylate transporter 1, 2 and 4 (MCT 1 2 and 4); upregulated the mRNA and protein expression of lactate dehydrogenase B (LDHB); and decreased the glycogen level, total LDH and GP activity, GS/p-GS ratio and lactate contents. Moreover, rolipram (20, 40 µM) or forskolin (20, 40 µM) could increase the lactate content by upregulating GP expression and the GS/p-GS ratio, as well as antagonize the effects of La. These results suggested that La-induced learning-memory damage was probably related to its suppression of lactate production in astrocytes and ANLT. This study provides some novel clues for clarifying the mechanism underlying the neurotoxicity of La.

The effect of nuclear factor erythroid 2-related factor/antioxidant response element signalling pathway in the lanthanum chloride-induced impairment of learning and memory in rats.

Lanthanum exerts adverse effects on the central nervous system. However, the mechanism underlying these adverse effects has not been clarified. It is known that oxidative stress plays an important role in neurological injuries induced by harmful factors. Nuclear factor erythroid 2-related factor (Nrf2) is very important in the response to oxidative stress in tissues and cells. The purpose of this study was to explore the effect of lanthanum chloride (LaCl3 ) on the spatial learning and memory of rats and to determine whether the Nrf2/antioxidant response element pathway acts in the hippocampus. Four groups of Wistar rats were exposed to 0 mM, 9 mM, 18 mM or 36 mM LaCl3 through their drinking water from the day of birth to 2 months after weaning. The results showed that LaCl3 impaired the spatial learning and memory of the rats, damaged the neuronal ultrastructure, increased reactive oxygen species levels and significantly down-regulated Nrf2 as well as the mRNA and protein expression of Nrf2-regulated genes, including NADP(H): dehydrogenase quinone 1, haeme oxygenase-1, superoxide dismutase 2, glutathione peroxidase 1, glutathione-S-transferase, γ-glutamine cysteine synthase and glutathione reductase, in the hippocampus. This study suggests that LaCl3 can impair the spatial learning and memory of rats, possibly by perturbing the Nrf2/antioxidant response element signalling pathway.

Lanthanum damages learning and memory and suppresses astrocyte-neuron lactate shuttle in rat hippocampus.

Rare-earth elements (REEs) are applied in various fields by virtue of their superior physical and chemical properties. Surveys have reported that REEs can impair learning and memory in children and induce neurobehavioral abnormalities in animals. However, the mechanism underlying this neurotoxicity is still unclear. Lanthanum (La) is often chosen to study the effects of REEs. Here, we investigated the role of astrocyte-neuron lactate shuttle (ANLS) in spatial learning and memory impairment induced by LaCl3 in hippocampus, an important spatial memory-related brain region. Pregnant Wistar rats were exposed to 0, 0.125, 0.25, 0.5, or 1% LaCl3 in drinking water during pregnancy and lactation. After weaning, young rats continued to receive 0, 0.125, 0.25, 0.5, and 1% LaCl3 in the drinking water for 1 month. The results showed that LaCl3 exposure impaired the spatial learning and memory of rats in Morris water maze test, significantly reduced the mRNA and protein levels of glycogen synthetase, glycogen phosphorylase, lactate dehydrogenase A, monocarboxylate transporter 4, MCT-1, and MCT-2, and decreased total LDH activity and lactate contents in rat hippocampus. These results indicate that LaCl3 impairs spatial learning and memory in rats probably by suppressing ANLS in rat hippocampus. The study provides a novel clue of energy supply for neurons to clarify the neurotoxicity of REEs.

Controllable synthesis of nickel bicarbonate nanocrystals with high homogeneity for a high-performance supercapacitor.

The electrochemical performance of supercapacitors might be associated with the homogeneous structure of the electrode materials. However, the relationship between the degree of uniformity for the electrode materials and the electrochemical performance of the supercapacitor is not clear. Herein, we synthesize two types of nickel bicarbonate nanocrystals with different degrees of uniformity to investigate this relationship. As the electroactive material, the nickel bicarbonate nanocrystals with a homogeneous structure could provide a larger space and offer more exposed atoms for the electrochemical reaction than the nanocrystals with a heterogeneous structure. The homogeneous nickel bicarbonate nanocrystals exhibit better electrochemical performance and show excellent specific capacitance (1596 F g-1 at 2 A g-1 and 1260 F g-1 at 30 A g-1), which is approximately twice that of the heterogeneous nickel bicarbonate nanocrystals. The cycling stability for the homogeneity (∼80%) is higher than the inhomogeneity (∼61%) at a high current density of 5 A g-1.

Protective Role of tert-Butylhydroquinone Against Sodium Fluoride-Induced Oxidative Stress and Apoptosis in PC12 Cells.

The neurotoxicity of fluoride is associated with oxidative stress due to imbalance between production and removal of reactive oxygen species (ROS). In contrast, induction of detoxifying and antioxidant genes through activation of NF-E2-related factor 2 (Nrf2) has been implicated in preventing oxidative stress and apoptosis in neurodegenerative diseases. The present study aimed to investigate the possible neuroprotective role of tert-butylhydroquinone (tBHQ), a general Nrf2 activator, on sodium fluoride (NaF)-induced oxidation damage and apoptosis in neuron-like rat pheochromocytoma (PC12) cells. Pretreatment with tBHQ protected PC12 cells against NaF-induced cytotoxicity as measured by MTT assay and apoptosis detection, simultaneously, inhibited NaF-induced overproduction of intracellular ROS and reduction of total glutathione content. Furthermore, NaF or tBHQ induced the stabilization of Nrf2, and enhanced expression of heme oxygenase-1 (HO-1) and γ-glutamylcysteine synthetase (γ-GCS) as a consequence of Nrf2 inducing. These findings indicated that tBHQ pretreatment conferred protective effect on PC12 cells against NaF-induced apoptotic cell death and oxidation-redox imbalance through stabilization of Nrf2 and elevation of downstream HO-1 and γ-GCS expressions.

Lanthanum chloride impairs spatial memory through ERK/MSK1 signaling pathway of hippocampus in rats.

Rare earth elements (REEs) are used in many fields for their diverse physical and chemical properties. Surveys have shown that REEs can impair learning and memory in children and cause neurobehavioral defects in animals. However, the mechanism underlying these impairments has not yet been completely elucidated. Lanthanum (La) is often selected to study the effects of REEs. The aim of this study was to investigate the spatial memory impairments induced by lanthanum chloride (LaCl3) and the probable underlying mechanism. Wistar rats were exposed to LaCl3 in drinking water at 0 % (control, 0 mM), 0.25 % (18 mM), 0.50 % (36 mM), and 1.00 % (72 mM) from birth to 2 months after weaning. LaCl3 considerably impaired the spatial learning and memory of rats in the Morris water maze test, damaged the synaptic ultrastructure and downregulated the expression of p-MEK1/2, p-ERK1/2, p-MSK1, p-CREB, c-FOS and BDNF in the hippocampus. These results indicate that LaCl3 exposure impairs the spatial learning and memory of rats, which may be attributed to disruption of the synaptic ultrastructure and inhibition of the ERK/MSK1 signaling pathway in the hippocampus.

[Study on the effect of deficient ERCC2/XPD gene on the repair of DNA damage induced by UVC in CHO cell line].

OBJECTIVE: To explore the function of ERCC2/XPD in the repair of DNA damage induced by UVC. METHODS: Chinese hamster ovary (CHO) cell line including AA8 (wild-type) and UV5 (mutant type, ERCC2/XPD defective), was selected as a cell control model. The cell inhibition rate of AA8 and UV5 after UVC treatment was estimated by MTT assay, and DNA repair capacity to difference irradiation intensity of UVC in cells after 1 h, 3 h, 6 h, 24 h incubation were measured by the Comet Assay and Rad51 immunofluorescence test. RESULTS: As compared to AA8, UV5 was more sensitive to UVC, and whose cell viability decreased. Comet assay and Rad51 immunofluorescence test results show, DNA damage level of UV5 was more serious than AA8. In addition, the DNA damage repair capacity reduced obviously compared with AA8. CONCLUSION: DNA damage repair capacity of UV5 cells reduced due to ERCC2/XPD defective, indicating us that ERCC2/XPD play a critical role in the repair process of DNA damage induced by UVC.

Downregulation of serum miR-17 and miR-106b levels in gastric cancer and benign gastric diseases.

Altered microRNA (miRNA) associated with gastric cancer (GC) development and miR-17 and miR-106b were differentially expressed in GC tissues. This study detected serum levels of miR-17 and miR-106b expression in GC, benign gastric disease (BGD) and healthy controls to assess them as tumor markers for GC. Serum samples from 40 GC, 32 BGD (10 gastric ulcer, 14 gastric polyps, and 8 gastric ulcer with polyps) and 36 healthy individuals were subjected to quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis of miR-17 and miR-106b expression. The data showed that the serum levels of miR-17 and miR-106b were significantly reduced in healthy individuals and BGD patients compared to GC patients. There was a significant association of miR-17 and miR-106b expression with age, but not with other clinicopathological features, such as gender, tumor differentiation, stage and lymphatic metastasis. Further analysis showed that, in discriminating GC patients from healthy controls, miR-17 could yield a receiver-operating characteristic (ROC) area under the curve (AUC) of 0.879 with 80.6% sensitivity and 87.5% specificity and miR-106b could yield an AUC of 0.856 with 75.0% sensitivity and 92.5% specificity. The combined AUC of miR-17 and miR-106b was 0.913 with 83.3% sensitivity and 87.5% specificity. Collectively, these data suggest that detection of serum miR-17 and miR-106b levels should be further evaluated as novel non-invasive biomarkers in early GC detection and surveillance of disease progression.