Identification of the passion fruit (Passiflora edulis Sims) MYB family in fruit development and abiotic stress, and functional analysis of PeMYB87 in abiotic stresses.

Environmental stresses are ubiquitous in agricultural cultivation, and they affect the healthy growth and development of edible tissues in passion fruit. The study of resistance mechanisms is important in understanding the adaptation and resistance of plants to environmental stresses. In this work, two differently resistant passion fruit varieties were selected, using the expression characteristics of the transcription factor MYB, to explore the resistance mechanism of the MYB gene under various environmental stresses. A total of 174 MYB family members were identified using high-quality passion fruit genomes: 98 2R-MYB, 5 3R-MYB, and 71 1R-MYB (MYB-relate). Their family information was systematically analyzed, including subcellular localization, physicochemical properties, phylogeny at the genomic level, promoter function, encoded proteins, and reciprocal regulation. In this study, bioinformatics and transcriptome sequencing were used to identify members of the PeMYB genes in passion fruit whole-genome data, and biological techniques, such as qPCR, gene clone, and transient transformation of yeast, were used to determine the function of the passion fruit MYB genes in abiotic stress tolerance. Transcriptomic data were obtained for differential expression characteristics of two resistant and susceptible varieties, three expression patterns during pulp development, and four induced expression patterns under abiotic stress conditions. We further focused on the resistance mechanism of PeMYB87 in environmental stress, and we selected 10 representative PeMYB genes for quantitative expression verification. Most of the genes were differentially induced by four abiotic stresses, among which PeMYB87 responded significantly to high-temperature-induced expression and overexpression of the PeMYB87 gene in the yeast system. The transgenic PeMYB87 in yeast showed different degrees of stress resistance under exposure to cold, high temperatures, drought, and salt stresses. These findings lay the foundation for further analysis of the biological functions of PeMYBs involved in stress resistance in passion fruit.

Norepinephrine promotes glioma cell migration through up-regulating the expression of Twist1.

BACKGROUND: Glioma cells are characterized by high migration ability, resulting in aggressive growth of the tumors and poor prognosis of patients. It has been reported that the stress-induced hormone norepinephrine (NE) contributes to tumor progression through mediating a number of important biological processes in various cancers. However, the role of NE in the regulation of glioma migration is still unclear. Epithelial-to-mesenchymal transition (EMT) is one of the most important steps for tumor migration and metastasis. Twist1, as a key regulator of EMT, has been found to be elevated during glioma migration. But it is still unknown whether Twist1 is involved in the effect of NE on the migration of glioma cells. METHODS: Wound healing assay and transwell assay were conducted to evaluate the migration of glioma cells upon different treatments. The mesenchymal-like phenotype and the expression of Twist1 after NE treatment were assessed by cell diameters, real-time PCR, western blot and immunofluorescence staining. The gain-and loss-of-function experiments were carried out to investigate the biological function of Twist1 in the migration induced by NE. Finally, the clinical significance of Twist1 was explored among three public glioma datasets. RESULTS: In this study, our finding revealed a facilitative effect of NE on glioma cell migration in a ß-adrenergic receptor (ADRB)-dependent way. Mechanistically, NE induced mesenchymal-like phenotype and the expression of Twist1. Twist1 overexpression promoted glioma cells migration, while knockdown of Twist1 abolished the discrepancy in the migration ability between NE treated glioma cells and control cells. In addition, the clinical analysis demonstrated that Twist1 was up-regulated in malignant gliomas and recurrent gliomas, and predicted a poor prognosis of glioma patients. CONCLUSIONS: NE enhanced the migration ability of glioma cells through elevating the expression of Twist1. Our finding may provide potential therapeutic target for protecting patients with glioma from the detrimental effects of stress biology on the tumor progression.

miR-137 Inhibition of the Invasion, Metastasis, and Epithelial-Mesenchymal Transition of Nasopharyngeal Cancer by Regulating KDM1A.

One of the most frequent malignancies in the head and neck is nasopharyngeal carcinoma (NPC). MicroRNAs, a kind of tiny noncoding RNA molecule, have been used as negative regulators in different types of cancer therapy in recent decades by downregulating their targets. Recent research suggests that microRNAs play an important role in cancer's epithelial-to-mesenchymal transition (EMT), supporting or inhibiting EMT development. The epithelial-to-mesenchymal transition (EMT) is linked to a variety of cancer-related activities, including growth, metastasis, and invasion. Previous research has linked EMT to cancer stem-like characteristics as well as treatment resistance. Moreover, since microRNAs (miRNAs) are important regulators of the EMT phenotype, certain miRNAs have an effect on cancer stemness and treatment resistance. As a result, both fundamental research and clinical therapy benefit from knowing the connection between EMT-associated miRNAs and cancer stemness/drug resistance. As a result, we looked at the different functions that EMT-associated miRNAs (miR-137) play in the stem-like characteristics of malignant cells in this article. Then we looked at how EMT-associated miRNAs interact with nasopharyngeal cancer's drug-resistant complex signaling pathways. Using qRT-PCR, we evaluated the performance of several micro RNAs with the proposed miR-137 for inhibiting invasion, metastasis, and the EMT process. In conclusion, our findings showed that miR-137 acted as a tumor suppressor gene in controlling NPC EMT and metastasis and that it may be a new therapeutic strategy and prognosis marker for the disease.

Chronic stress promotes glioma cell proliferation via the PI3K/Akt signaling pathway.

High malignancy and high mortality of glioma render it urgent to elucidate the underlying mechanisms of glioma carcinogenesis and explore novel targets for therapy. Epidemiologic and clinical studies have revealed that chronic stress promotes the progression of various solid tumors and is correlated with poor prognosis; however, findings reporting the involvement of chronic stress in glioma are rare. In the present study, a chronic restraint animal model and a chronic stress cell model were established to explore the effects of chronic stress on glioma and its molecular mechanisms. The results revealed that chronic stress promoted glioma growth in vivo, and the serum levels of the stress hormones glucocorticoid (GC) and noradrenaline (NE) were significantly increased. In addition, GC and NE were verified to accelerate the proliferation of glioma cells in vitro. Mechanistically, the phosphatidylinositol 3­kinase (PI3K)/Akt signaling pathway was revealed to be activated under stress conditions, and inhibition of the expression of p­Akt could restrain the stress hormone­induced glioma cell proliferation. In addition, our data indicated that the GC receptor (GR) and ß­adrenergic receptors (ADRBs) were both required for the biological functions of GC and NE in glioma cells. In conclusion, these results indicated that chronic stress and the stress hormones GC and NE activated PI3K/Akt signaling through binding to GR and ADRBs, thereby promoting glioma cell growth. Our findings may provide potential therapeutic targets and pave the way for the development of new strategies to protect patients with glioma from the detrimental effects of stress on tumor progression.

D-serine reduces memory impairment and neuronal damage induced by chronic lead exposure.

Although exogenous D-serine has been applied as a neural regulatory intervention in many studies, the role played by D-serine in hippocampal injuries caused by lead exposure remains poorly understood. Rat models of chronic lead exposure were established through the administration of 0.05% lead acetate for 8 weeks. Simultaneously, rats were administered 30 or 60 mg/kg D-serine, intraperitoneally, twice a day. Our results showed that D-serine treatment shortened the escape latency from the Morris water maze, increased the number of times that mice crossed the original platform location, and alleviated the pathological damage experienced by hippocampal neurons in response to lead exposure. Although D-serine administration did not increase the expression levels of the N-methyl-D-aspartate receptor subtype 2B (NR2B) in the hippocampi of lead-exposed rats, 60 mg/kg D-serine treatment restored the expression levels of NR2A, which are reduced by lead exposure. These findings suggested that D-serine can alleviate learning and memory impairments induced by lead exposure and that the underlying mechanism is associated with the increased expression of NR2A in the hippocampus. This study was approved by the Animal Ethics Committee of North China University of Science and Technology, China (approval No. LX2018155) on December 21, 2018.

Efficacy, immunogenicity and safety of the AS04-HPV-16/18 vaccine in Chinese women aged 18-25 years: End-of-study results from a phase II/III, randomised, controlled trial.

BACKGROUND: Cervical cancer is a major public health concern in China. We report the end-of-study results of a phase II/III trial to assess the efficacy, immunogenicity, and safety of the AS04-human papillomavirus (HPV)-16/18 vaccine in Chinese women aged 18-25 years followed for up to 72 months after first vaccination. Results of approximately 57 months following first vaccination have been previously reported. METHODS: Healthy 18-25-year-old women (N = 6051) were randomized (1:1) to receive three doses of AS04-HPV-16/18 vaccine or Al(OH)3 (control) at Months 0-1-6. Vaccine efficacy against HPV-16/18 infection and cervical intraepithelial neoplasia (CIN), cross-protective vaccine efficacy against infections and lesions associated with nonvaccine oncogenic HPV types, immunogenicity, and safety were assessed. Efficacy was assessed in the according-to-protocol efficacy (ATP-E) cohort (vaccine N = 2888; control N = 2892), total vaccinated cohort for efficacy (TVC-E; vaccine N = 2987; control N = 2985) and TVC-naïve (vaccine N = 1660; control N = 1587). RESULTS: In initially HPV-16/18 seronegative/DNA-negative women, vaccine efficacy against HPV-16/18-associated CIN grade 2 or worse was 87.3% (95% CI: 5.5, 99.7) in the ATP-E, 88.7% (95% CI: 18.5, 99.7) in the TVC-E, and 100% (95% CI: 17.9, 100) in the TVC-naïve. Cross-protective efficacy against incident infection with HPV-31, HPV-33 and HPV-45 was 59.6% (95% CI: 39.4, 73.5), 42.7% (95% CI: 15.6, 61.6), and 54.8% (95% CI: 19.3, 75.6), respectively (ATP-E). At Month 72, >95% of initially seronegative women who received HPV vaccine in the ATP cohort for immunogenicity (N = 664) remained seropositive for anti-HPV-16/18 antibodies; anti-HPV-16 and anti-HPV-18 geometric mean titers were 678.1 EU/mL (95% CI: 552.9, 831.5) and 343.7 EU/mL (95% CI: 291.9, 404.8), respectively. Serious adverse events were infrequent (1.9% vaccine group [N = 3026]; 2.7% control group [N = 3025]). Three and zero women died in the control group and the vaccine group respectively. New onset autoimmune disease was reported in two women in the vaccine group and two in the control group. CONCLUSIONS: This is the first large-scale randomized clinical trial of HPV vaccination in China. High and sustained vaccine efficacy against HPV-16/18-associated infection and cervical lesions was demonstrated up to Month 72. The vaccine had an acceptable safety profile. Combined with screening, prophylactic HPV vaccination could potentially reduce the high burden of HPV infection and cervical cancer in China. TRIAL REGISTRATION: NCT00779766.

Aberrant hypermethylation of the HOXD10 gene in papillary thyroid cancer with BRAFV600E mutation.

Epigenetic abnormalities as well as genetic abnormalities may play a vital role in the tumorigenesis of papillary thyroid cancer (PTC). The present study aimed to analyze the function and methylation status of the HOXD10 gene in PTC and aimed to identify relationships between HOXD10 methylation, HOXD10 expression, BRAF mutation and clinicopathological characteristics of PTC. A total of 152 PTC patients were enrolled in the present study. The methylation status of the HOXD10 promoter was analyzed by quantitative methylation-specific polymerase chain reaction (Q-MSP). BRAFV600E mutation status was analyzed by polymerase chain reaction (PCR) followed by DNA sequencing. HOXD10 mRNA expression level was analyzed by real-time polymerase chain reaction (RT-PCR). 5-Aza-2-deoxycytidine (5-Aza) treatment was performed in 4 PTC cell lines to observe the change in HOXD10 expression. Transwell, cell cycle and apoptosis assays were then performed in an HOXD10-overexpressing PTC cell line. Furthermore, we analyzed the associations between HOXD10 methylation, HOXD10 expression, BRAF mutation and clinicopathological characteristics in PTC. Overexpression of HOXD10 suppressed the migration of PTC cells, and promoted cell apoptosis. Q-MSP showed that methylation levels of the HOXD10 promoter were significantly higher in PTC tissues than levels in the adjacent normal thyroid tissues (P=0.02). In addition, expression of HOXD10 was decreased in the PTC cell lines and PTC tissues compared with that noted in the adjacent normal thyroid tissues (P=0.008). However, BRAFV600E mutation was detected in 42.1% of PTC patients enrolled. In addition, the BRAF mutation status was associated with the methylation and expression level of HOXD10 in PTC. We then observed that 5-Aza treatment could revert the expression of HOXD10 in PTC cell lines. Moreover, the hypermethylation of HOXD10 was associated with invasion of the primary tumor and age >45. In conclusion, the HOXD10 gene may act as a tumor suppressor in PTC. The aberrant hypermethylation and decreased expression of the HOXD10 gene were shown in PTC patients, particularly in those with BRAFV600E mutation. The epigenetic suppression of the HOXD10 gene may play a role in the tumorigenesis of PTC, and it is a prospective biomarker for the diagnosis and prognosis of PTC.

Efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine in Chinese women aged 18-25 years: event-triggered analysis of a randomized controlled trial.

We previously reported the results of a phase II/III, double-blind, randomized controlled study in Chinese women (NCT00779766) showing a 94.2% (95% confidence interval: 62.7-99.9) HPV-16/18 AS04-adjuvanted vaccine efficacy (VE) against cervical intraepithelial neoplasia grade 1 or higher (CIN1+) and/or 6-month (M) persistent infection (PI) with a mean follow-up of <2 years, and immunogenicity until 7 months post-dose 1. Here, we report efficacy and safety results from an event-triggered analysis with ~3 years longer follow-up, and immunogenicity until M24. Healthy 18-25-year-old women (N = 6051) were randomized (1:1) to receive three doses of HPV-16/18 vaccine or Al(OH)3 (control) at M0, 1, 6. VE against HPV-16/18-associated CIN2+, and cross-protective VE against infections with nonvaccine oncogenic HPV types, immunogenicity, and safety were assessed. In the according-to-protocol efficacy cohort, in initially seronegative/DNA-negative women (vaccine group: N = 2524; control group: N = 2535), VE against HPV-16/18-associated CIN2+ was 87.3% (5.3-99.7); VE against incident infection or against 6-month persistent infection associated with HPV-31/33/45 was 50.1% (34.3-62.3) or 52.6% (24.5-70.9), respectively. At least, 99.6% of HPV-16/18-vaccines remained seropositive for anti-HPV-16/18 antibodies; anti-HPV-16 and -18 geometric mean titers were 1271.1 EU/mL (1135.8-1422.6) and 710.0 EU/ml (628.6-801.9), respectively. Serious adverse events were infrequent (1.7% vaccine group [N = 3026]; 2.5% control group [N = 3026]). Of the 1595 reported pregnancies, nine had congenital anomalies (five live infants, three elective terminations, one stillbirth) that were unlikely vaccination-related (blinded data). VE against HPV-16/18-associated CIN2+ was demonstrated and evidence of cross-protective VE against oncogenic HPV types was shown. The vaccine was immunogenic and had an acceptable safety profile.

Efficacy, immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Chinese women aged 18-25 years: results from a randomized controlled trial.

This phase II/III, double-blind, randomized trial assessed the efficacy, immunogenicity and safety of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in young Chinese women (ClinicalTrials.gov registration NCT00779766). Women aged 18-25 years from Jiangsu province were randomized (1:1) to receive HPV vaccine (n = 3,026) or Al(OH)3 control (n = 3,025) at months 0, 1 and 6. The primary objective was vaccine efficacy (VE) against HPV-16/18 associated 6-month persistent infection (PI) and/or cervical intraepithelial neoplasia (CIN) 1+. Secondary objectives were VE against virological and clinical endpoints associated with HPV-16/18 and with high-risk HPV types, immunogenicity and safety. Mean follow-up for the according-to-protocol cohort for efficacy (ATP-E) was ∼15 months after the third dose. In the ATP-E (vaccine = 2,889; control = 2,894), for initially HPV DNA negative and seronegative subjects, HPV-16/18 related VE (95% CI) was 94.2% (62.7, 99.9) against 6-month PI and/or CIN1+ and 93.8% (60.2, 99.9) against cytological abnormalities. VE against HPV-16/18 associated CIN1+ and CIN2+ was 100% (-50.4, 100) and 100% (-140.2, 100), respectively (no cases in the vaccine group and 4 CIN1+ and 3 CIN2+ cases in the control group). At Month 7, at least 99.7% of initially seronegative vaccine recipients had seroconverted for HPV-16/18; geometric mean antibody titres (95% CI) were 6,996 (6,212 to 7,880) EU/mL for anti-HPV-16 and 3,309 (2,942 to 3,723) EU/mL for anti-HPV-18. Safety outcomes between groups were generally similar. The HPV-16/18 AS04-adjuvanted vaccine is effective, immunogenic and has a clinically acceptable safety profile in young Chinese women. Prophylactic HPV vaccination has the potential to substantially reduce the burden of cervical cancer in China.

[Disorder of copper homeostasis induced by lead exposure among mice and intervention effect of quercetin].

OBJECTIVE: To investigate the effect of lead exposure on copper and copper metalloenzyme and the intervention effect of quercetin. METHODS: Twenty-four specific pathogen-free male Sprague-Dawley rats of good health were randomly divided into control group (n = 8), lead acetate group (n = 8), and lead acetate + quercetin group (n = 8). The rats in lead acetate group were poisoned by drinking water with 1 g/L lead acetate for 8 weeks, while the rats in control group were fed by drinking water with sodium acetate of the same volume for 8 weeks; the rats in lead acetate+quercetin group were intraperitoneally injected with quercetin (30 mg × kg-1 × d-1) for 8 weeks while drinking water with lead acetate. The Morris water maze was used to test the learning and memory abilities of rats. The lead and copper levels in the serum, hippocampus, cortex, and bone were measured by graphite furnace atomic absorption spectrometry. The level of advanced glycation end products, activity of Cu/Zn superoxide dismutase (SOD), and content and activity of ceruloplasmin (CP) in the hippocampus and serum were measured using a test kit. HE staining was performed to observe the pathological changes in the hippocampus. RESULTS: The Morris water maze test showed that the latency in lead acetate group (52.50±12.04 s) was significantly longer than that in control group (28.08±7.31 s) (P<0.05), and the number of platform crossings was significantly lower in the lead acetate group than in the control group. Compared with those in the control group, the lead levels in the cortex and hippocampus in lead acetate group increased 2.72-fold and 3.79-fold, and the copper in the cortex and hippocampus, and serum free copper levels in lead acetate group increased 1.15-fold, 1.48-fold, and 6.44-fold. Compared with the control group, the lead acetate group had a lower content of CP in the hippocampus (1.23±0.40 U/mg provs0.78±0.08 U/mg pro) and 31.81%and 19.49%decreases in CP content and Cu/Zn SOD activity. Free copper level in serum was positively correlated with the latency and lead levels in the serum, cortex, and hippocampus. The escape latency of rats in lead acetate + quercetin group was decreased by 42.15% (P<0.05). The lead levels in the cortex and hippocampus in lead acetate + quercetin group (0.246 ± 0.58 µg/g and 0.202±0.049 µg/g) were significantly lower than those in lead acetate group (0.391±0.49 µg/g and 0.546±0.120 µg/g), but the free copper and copper levels in the hippocampus and cortex were not significantly reduced. The lead acetate + quercetin group had higher Cu/Zn SOD activity and CP content in the hippocampus than the lead acetate group (P < 0.05). The light microscope observation showed that the number of cells in the hippocampus was reduced with disordered arrangement in the lead acetate group; with quercetin intervention, the hippocampus damage was reduced. CONCLUSION: Lead exposure results in disorder of copper homeostasis, while quercetin may alleviate the damage induced by lead to some extent.

[The change of pulmonary surfactant protein of rat following silica exposure].

OBJECTIVE: To investigate the change of lung surfactant protein (SP) A,B,C,D of rats following silica dust exposure in order to provide the evidences for the early diagnosis indices or therapy of silicosis. METHODS: 60 male SD rats were randomly divided into silica group, and corresponding controls group. Rats in silica group were administrated 1 ml silica solution by intratracheal instillation at dose of 50 mg/ml. Rats in control group were administrated the same amount saline. At 3rd, 7th, 14th, 21st, 28th after silica exposure, serum and bronchoalveolar lavage fluid (BALF) samples were obtained. The concentration of SP-A, SP-B, SP-C, SP-D in serum and BALF were measured by using enzyme immunoassay (ELISA). Meanwhile the levels of total anti-oxidative activity (T-AOC) and hydroxyproline (HYP) in lung tissue were also detected. The pathology of lung tissue was conducted. RESULTS: Compared with control group, SP-A concentration in BALF of silica exposed rat for 3, 14, 21, 28d was significant lower and SP-D concentration in BALF of silica exposed rat for all time points was also lower. The differences were significant (P < 0.05). Meanwhile SP-B level in 7, 14, 21, 28 d silica exposed rats BALF and SP-C level in 14, 21, 28 d silica exposed rats markedly decreased (P < 0.05). In addition compared with control group, SP-A, SP-B and SP-C concentration in serum of silica exposed rat were higher when SP-A for 14, 21, 28 d silica exposure, SP-B for 7, 14, 21 d silica exposure and Sp-C for 7, 14, 21, 28 d exposure. And all difference were significant (P < 0.05). As silica exposure time increased, SP-C concentration in serum showed an increase trend, which showed a time-response relationship (r = 0.618, P = 0.042). However, SP-D concentration in serum of rat for 7, 14, 21, 28d silica exposure were significant lower than that of control group (P < 0.005). And there was a decrease trend with time point exposure regarding of SP-D (r = -0.731, P = 0.016). The HYP content in lung tissue of experiment rats increased at 3rd, 7th, 14th, 21st and 28th day time point and The T-AOC activity in lung tissue decrease at, 7th, 14th, 21st and 28th day time point. The differences were significant (P < 0.05). There was a positive correlation (P = 0.803, P = 0.045) between SP-C in BALF and HYP of silica exposed rats and a negative correlation between SP-D in BALF and HYP (r = -0.867, P = 0.033). No significant correlation were seen between SP-A, SP-B BALF and HYP (y = 0.416, P = 0.28; r = 0.592, P = 0.071). SP-C concentration in BALF and serum all showed an increased trend and a positive correlation was seen (r = 0.539, P = 0.046). The same decrease trend was seen between SP-D in BALF and serum and correlation value was 0.870 (P = 0.034). CONCLUSION: The silica exposure did cause the change of SP content both in BALF and serum. The SP-C and SP-D content in serum might be served as an early effective biomarker of silicosis.

[Effects of acrylamide on the permeability of blood cerebrospinal fluid barrier in rats].

OBJECTIVE: To explore the effects of acrylamide on the permeability of blood cerebrospinal fluid barrier (BCB) and tight junction protein ZO-1 of choroid plexus in rats and to provide a theoretical basis for explaining the mechanism of nerve injury induced by acrylamide. METHODS: Thirty two male Sprague-Dawley rats were randomly divided into ACR and control groups. ACR group was exposed to 20 mg/kg ACR daily for 5 days a week by intraperitoneal injection (i.p.) for 4 weeks. Control group was exposed to normal saline. The neurobehavioral tests (including sensatory and motor functions) were performed every week. At the end of exposure, Evan blue (EB) and Sodium fluorescein (NaFI) content in rat CSF were detected for determining the BCB permeability, Real-time PCR was used to measure the expression levels of ZO-1 mRNA in the epithelium cells of choroid plexus, and laser scanning confocal microscope (LSCM) was utilized to observe the distribution of ZO-1 protein. RESULTS: Neurobehavioral tests showed that the tail-flick latencies of ACR group were 27.77% and 53.71% as long as control group in the 3rd week and 4th week, respectively (P < 0.05). The hind lamb splay distances of ACR group were 131.76% and 153.77% as long as control group in the 3rd week and 4th week, respectively (P < 0.05). Evan blue (EB) and Sodium fluorescein (NaFI) content of ACR group were significantly higher than those of control group (P < 0.05). In the 4th week, the expression level of ZO-1 mRNA in ACR group was 0.21 +/- 0.07, which was significantly lower than that (0.31 +/- 0.11) in control group (P < 0.05). In the 4th week, the ZO-1 protein expression level of choroid plexus in ACR group was significantly lower than that in control group (P < 0.05). CONCLUSION: Acrylamide could increased the BCB permeability of rats, which may be involved in the central nervous injury induced by ACR.

[Preliminary study of biomarker in blood or cerebrospinal fluid of rat following manganese exposure].

OBJECTIVE: To explore the biomarkers of manganese exposure by measuring the manganese (Mn) and iron (Fe) level as well as the mRNA change of Hepcidin, divalent metal-ion transporter-1 (DMT1) and Parkin-2, one of genes related to Parkinson disease in body fluid and brain tissues of rat. METHODS: Male Sprague-Dawley rats were administered (i.p) either MnCl2 solution (6 mg Mn/kg) or the same volume saline, 5 times per week and for 4 weeks. Graphic furnace Atom Absorption Spectrum (AAS) was applied to measure the concentration of Mn and Fe in brain tissue and body fluids. Meanwhile Hepcidin, DMT1 and Parkin-2 mRNA expression were detected by real-time RT-PCR. RESULTS: Mn concentration in erythrocytes of rats was the 86.9 folds of that in control; No significant change was found in plasma. However the trend and range of Mn increase in cerebrospinal fluid (CSF) was the same as that in brain tissue including striatum, cortex, hippocampus and choroid plexus. Meanwhile Fe concentration in brain tissue of Mn exposed rats was also higher than that of control, whose trend was as same as that in CSF. However iron concentration in plasma decreased. The real-time RT-PCR data also showed that Hepcidin mRNA expression in Mn-exposed rat decreased 56% in blood, which was in line with its expression in cortex(67%). Similarly, Parkin-2 mRNA expression decreased both in blood (42%) and in striatum. However DMT1 mRNA expression increase 38% in striatum of Mn-exposed rats but decreased in blood. CONCLUSION: Hepcidin and Parkin-2 mRNA expression in blood might be serves as the effective biomarkers following manganese exposure, certainly which needs to be further explored.

[The effect of 2,5-hexanedione on nerve growth factor in sciatic nerve of rats and VSC4.1 cell].

OBJECTIVE: To explore the effect of 2,5-hexanedione (2,5-HD) on the levels of nerve growth factor (NGF) in sciatic nerve of rats and motor-neurons. METHOD: A total of 50 Wistar rats were randomly designed into five groups and intoxicated with 400 mgxkg(-1)xd(-1) 2,5-HD for 0, 7, 14, 21, 28 d. Immunohistochemistry and real-time PCR were used to detect the levels of NGF and NGF mRNA. Motor neuron VSC4.1 cells were administrated with 0, 2.5, 5.0, 10.0, 20.0 mmol/L 2,5-HD for 24 h and 10.0 mmol/L 2,5-HD was chosen to intoxicated VSC4.1 cells for 0, 1, 3, 6, 12, 24, 48 h respectively. Immunofluorescence technique was selected to detect the levels of NGF. RESULTS: The NGF level in sciatic nerve of rats administrated with 400 mgxkg(-1)xd(-1) 2,5-HD showed increase tendency at begin and then decrease after exposure. The NGF mRNA level in 14 d (2(-DeltaDeltaCt)= 3.46), 21 d (2(-DeltaDeltaCt)= 5.28) and 28 d (2(-DeltaDeltaCt)= 3.10) were higher than those in 0 d (2(-DeltaDeltaCt)= 1) and 7 d (2(-DeltaDeltaCt)= 0.78). In vitro tests of VSC4.1 cells showed that NGF levels in 5.0 mmol/L (43.24 +/- 7.52), 10.0 mmol/L (43.48 +/- 10.86) and 20.0 mmol/L (63.13 +/- 10.68) were higher than those in 0 mmol/L (16.32 +/- 4.20)(q values were 19.92, 19.72, 32.78, respectively, P < 0.01) and 2.5 mmol/L (19.78 +/- 2.66) (q values were 17.50, 17.42, 30.63, respectively, P < 0.01) in 24 h and the NGF level in 20.0 mmol/L was higher than those in 5.0 mmol/L (q = 13.04, P < 0.01) and 10.0 mmol/L (q = 11.71, P < 0.01). The NGF levels of VSC4.1 cells with 10.0 mmol/L 2,5-HD in 6 h (18.66 +/- 2.89), 12 h (23.14 +/- 6.08), 24 h (27.66 +/- 6.11) and 48 h (17.25 +/- 3.05) were increased compared with that in 0 h (10.18 +/- 1.81) (q values were 9.64, 15.74, 21.76, 8.50, respectively, P < 0.01), 1 h (9.31 +/- 1.28) (q values were 10.28, 16.17, 21.95, 9.20, respectively, P < 0.01) and 3 h (10.44 +/- 2.13) (q values were 9.25, 15.24, 21.17, 8.10, respectively, P < 0.01), and NGF levels in 12 h and 24 h increased compared with those in 6 h (q values were 5.24, 10.77, respectively, P < 0.01) and 48 h (q values were 7.31, 13.26, respectively, P < 0.01). CONCLUSION: 2,5-HD could increase NGF levels in sciatic nerve of rats and motor-neurons, and the dose or time dependent effects were observed in this study.

[Effect of 2, 5-hexanedione on calcium homeostasis of motor neuron].

OBJECTIVE: To explore the mechanism of cytotoxic effect of 2, 5-hexanedione (2, 5-HD) on motor neuron. METHODS: Vsc4.1 (a cell line from motor neuron) was incubated with a series concentration of 2, 5-HD. The cell viability, Ca(2+) Mg(2+) ATPase and Na(+)K(+) ATPase were detected. Laser scanning confocal microscope (LSCM) was used for detecting intracellular calcium level. The average calcium level in VSC4.1 was measured by flow cytometry. RESULTS: The cell viability was decreased when Vsc4.1 cells were treated with 2, 5-HD at the dosage of 2.5, 5.0, 7.5, 10, 15 and 20 mmol/L for 24 hours. Compared with the control group the activity of Ca(2+) Mg(2+) ATPase was decreased to 70.02%, 77.44% and 47.47% respectively; the activity of Na(+)K(+) ATPase was decreased to 82.07%, 72.45% and 50.71%. The difference was significant. Intracellular free calcium of VSC4.1 cell was increased rapidly within 10 s and then recovered within 40 seconds when it was exposed to 33.5 mmol/L 2, 5-HD. An increase in intracellular calcium was observed when the VSC4.1 was treated with 33.5 mmol/L 2, 5-HD. The peak of intracellular calcium level occurred ten minutes later. CONCLUSION: The disturbance of calcium homeostasis may be involved in the mechanisms of neurotoxicity of 2, 5-HD.

[Association between XRCC1 gene polymorphisms and DNA damage of workers exposed to formaldehyde].

OBJECTIVE: To investigate the association between polymorphisms of DNA repair gene XRCC1 and DNA damage in peripheral blood lymphocytes among workers exposed to formaldehyde. METHODS: One hundred and fifty-one workers exposed to formaldehyde from plywood factories and one hundred and twelve workers without occupational exposure to formaldehyde were recruited into this study. DNA damage levels were measured by comet assay. The polymorphisms of XRCC1 gene were analyzed by polymerase chain reaction(PCR) with restriction fragment length polymorphism(RFLP) method. The multiple covariance analysis was used to compare olive trail moment and comet trail length adjusted confounding factors. RESULTS: In formaldehyde exposed workers, after ages, smoking and drinking status and occupational exposure level were adjusted, means of Olive trail moment and comet trail length in the subjects with variant genotype at Arg280 His site (geometric means 4.30 and 13.42 respectively) were higher than subjects with wild type homozygote (geometric means 3.38 and 11.71 respectively), the differences were significant (Olive trail moment: P < 0.05, comet trail length: P < 0.01) . No associations between the polymorphisms at other three sites in XRCC1 gene and means of olive trail moment and comet trail length in exposure workers were found. CONCLUSION: The polymorphisms of XRCC1 gene may modulate the effects of DNA damages induced by formaldehyde in workers.

[Effects of 2,5-hexanedione on NGF expression in motor and sensory neuronal cells of rats].

OBJECTIVE: To investigate the effects of 2,5-Hexanedione (2,5-HD), a metabolite of n-hexane,on nerve growth factor (NGF) expression in motor and sensory neuronal cells of peripheral nervous system of rats. METHODS: Primary cultured dorsal root ganglion (DRG) neurons were obtained from new born rats on day 4. The cell line VSC4.1 were cultured. The growth condition of cells were observed with a phase contrast microscope. Immunohistochemistry technology was used to analyze the NGF expression in both VSC4.1 cells and primary cultured DRG cells treated with 4 different dosages of 2, 5-HD (2.5, 5.0, 10.0, 20.0 mmol/L) respectively for 24 hours. RESULTS: The NGF expression decreased significantly in both DRG neurons and VSC4.1 cells dosed respectively with 5.0,10.0,20.0 mmol/L 2,5-HD in comparison with the control group (P < 0.05), with a tendency of dose-effect correlation. CONCLUSION: The results suggested that 2,5-HD can decrease the endogenous NGF levels in both cultured DRG sensory neurons and VSC4.1 motor neuron cells of rats.