Identification and Validation of SLC9A2 as A Potential Tumor Suppressor in Colorectal Cancer: Integrating Bioinformatics Analysis with Experimental Confirmation.

OBJECTIVE: To uncover the mechanisms underlying the development of colorectal cancer (CRC), we applied bioinformatic analyses to identify key genes and experimentally validated their possible roles in CRC onset and progression. METHODS: We performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis on differentially expressed genes (DEGs), constructed a protein-protein interaction (PPI) network to find the top 10 hub genes, and analyzed their expression in colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ). We also studied the correlation between these genes and immune cell infiltration and prognosis and validated the expression of SLC9A2 in CRC tissues and cell lines using qRT-PCR and Western blotting. Functional experiments were conducted in vitro to investigate the effects of SLC9A2 on tumor growth and metastasis. RESULTS: We found 130 DEGs, with 45 up-regulated and 85 down-regulated in CRC. GO analysis indicated that these DEGs were primarily enriched in functions related to the regulation of cellular pH, zymogen granules, and transmembrane transporter activity. KEGG pathway analysis revealed that the DEGs played pivotal roles in pancreatic secretion, rheumatoid arthritis, and the IL-17 signaling pathway. We identified 10 hub genes: CXCL1, SLC26A3, CXCL2, MMP7, MMP1, SLC9A2, SLC4A4, CLCA1, CLCA4, and ZG16. GO enrichment analysis showed that these hub genes were predominantly involved in the positive regulation of transcription. Gene expression analysis revealed that CXCL1, CXCL2, MMP1, and MMP7 were highly expressed in CRC, whereas CLCA1, CLCA4, SLC4A4, SLC9A2, SLC26A3, and ZG16 were expressed at lower levels. Survival analysis revealed that 5 key genes were significantly associated with the prognosis of CRC. Both mRNA and protein expression levels of SLC9A2 were markedly reduced in CRC tissues and cell lines. Importantly, SLC9A2 overexpression in SW480 cells led to a notable inhibition of cell proliferation, migration, and invasion. Western blotting analysis revealed that the expression levels of phosphorylated ERK (p-ERK) and phosphorylated JNK (p-JNK) proteins were significantly increased, whereas there were no significant changes in the expression levels of ERK and JNK following SLC9A2 overexpression. Correlation analysis indicated a potential link between SLC9A2 expression and the MAPK signaling pathway. CONCLUSION: Our study suggests that SLC9A2 acts as a tumor suppressor through the MAPK pathway and could be a potential target for CRC diagnosis and therapy.

Study of cabbage antioxidant system response on early infection stage of Xanthomonas campestris pv. campestris.

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) significantly affects the production of cabbage and other cruciferous vegetables. Plant antioxidant system plays an important role in pathogen invasion and is one of the main mechanisms underlying resistance to biological stress. Therefore, it is important to study the resistance mechanisms of the cabbage antioxidant system during the early stages of Xcc. In this study, 108 CFU/mL (OD600 = 0.1) Xcc race1 was inoculated on "zhonggan 11" cabbage using the spraying method. The effects of Xcc infection on the antioxidant system before and after Xcc inoculation (0, 1, 3, and 5 d) were studied by physiological indexes determination, transcriptome and metabolome analyses. We concluded that early Xcc infection can destroy the balance of the active oxygen metabolism system, increase the generation of free radicals, and decrease the scavenging ability, leading to membrane lipid peroxidation, resulting in the destruction of the biofilm system and metabolic disorders. In response to Xcc infection, cabbage clears a series of reactive oxygen species (ROS) produced during Xcc infection via various antioxidant pathways. The activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased after Xcc infection, and the ROS scavenging rate increased. The biosynthesis of non-obligate antioxidants, such as ascorbic acid (AsA) and glutathione (GSH), is also enhanced after Xcc infection. Moreover, the alkaloid and vitamin contents increased significantly after Xcc infection. We concluded that cabbage could resist Xcc invasion by maintaining the stability of the cell membrane system and improving the biosynthesis of antioxidant substances and enzymes after infection by Xcc. Our results provide theoretical basis and data support for subsequent research on the cruciferous vegetables resistance mechanism and breeding to Xcc.

Effect of hydrogen sulfide on cabbage photosynthesis under black rot stress.

Hydrogen sulfide (H2S), as a potential gaseous signaling molecule, is involved in mediating biotic and abiotic stress in plants. Currently, there are no studies investigating the mechanism by which H2S improves photosynthesis under black rot (BR) stress caused by Xanthomonas campestris pv. Campestris (Xcc). In this study, we investigated the effect of exogenous H2S on Xcc induced photosynthetic impairment in cabbage seedlings. BR has an inhibitory effect on the photosynthetic ability of cabbage seedlings. Xcc infection can significantly reduce the chlorophyll content, photosynthetic characteristics, chlorophyll fluorescence, Calvin cycle related enzyme activity and gene expression in cabbage leaves. The use of H2S can alleviate this inhibitory effect, reduce chlorophyll decomposition, improve gas exchange, enhance the activity of Calvin cycle related enzymes, and increase the expression of related genes. Transcriptome analysis showed that all differential genes related to photosynthesis were up regulated under H2S treatment compared to normal inoculation. Therefore, spraying exogenous H2S can improve the photosynthetic capacity of cabbage seedlings, reduce Xcc induced photoinhibition, and improve plant resistance.

Organoids derived from patients provide a new opportunity for research and individualized treatment of malignant peritoneal mesothelioma.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is an extremely rare and highly invasive tumor. Due to the lack of accurate models that reflect the biological characteristics of primary tumors, studying MPM remains challenging and is associated with an exceedingly unfavorable prognosis. This study was aimed to establish a new potential preclinical model for MPM using patient-derived MPM organoids (MPMOs) and to comprehensively evaluate the practicality of this model in medical research and its feasibility in guiding individualized patient treatment. METHODS: MPMOs were constructed using tumor tissue from MPM patients. Histopathological analysis and whole genome sequencing (WGS) were employed to determine the ability of MPMOs to replicate the original tumor's genetic and histological characteristics. The subcutaneous and orthotopic xenograft models were employed to assess the feasibility of establishing an in vivo model of MPM. MPMOs were also used to conduct drug screening and compare the results with retrospective analysis of patients after treatment, in order to evaluate the potential of MPMOs in predicting the effectiveness of drugs in MPM patients. RESULTS: We successfully established a culture method for human MPM organoids using tumor tissue from MPM patients and provided a comprehensive description of the necessary medium components for MPMOs. Pathological examination and WGS revealed that MPMOs accurately represented the histological characteristics and genomic heterogeneity of the original tumors. In terms of application, the success rate of creating subcutaneous and orthotopic xenograft models using MPMOs was 88% and 100% respectively. Drug sensitivity assays demonstrated that MPMOs have different medication responses, and these differences were compatible with the real situation of the patients. CONCLUSION: This study presents a method for generating human MPM organoids, which can serve as a valuable research tool and contribute to the advancement of MPM research. Additionally, these organoids can be utilized as a means to evaluate the effectiveness of drug treatments for MPM patients, offering a model for personalized treatment approaches.

Raman Spectroscopy of Emulsions and Emulsion Chemistry.

Emulsions are dispersed systems widely used in various industries. In recent years, Raman spectroscopy (RS), as a spectroscopic technique, has gained much attention for measuring and monitoring emulsions. In this review, we explore the use of RS on emulsion structures and emulsification, important reactions that use emulsions such as emulsion polymerization, catalysis and cascading reactions, as well as various applications of emulsions. We explore how RS is used in emulsions, reactions and applications. RS is a powerful and versatile tool for studying emulsions, but there are also challenges in using RS to monitor emulsion processes, especially if they are rapid or volatile. We also explore these challenges and difficulties, as well as possible designs that can be used to overcome them.

[Different operation sequences between acupuncture and cupping therapy for lumbar muscle strain with cold and dampness: a randomized controlled trial].

OBJECTIVE: To compare the clinical efficacy on lumbar muscle strain with cold and dampness between the different operation sequences of acupuncture and cupping therapy. METHODS: Seventy-six patients with lumbar muscle strain with cold and dampness were randomly divided into an acupuncture + cupping group (A + C group, 38 cases) and a cupping + acupuncture group (C + A group, 38 cases, 1 case dropped off). In the A + C group, cupping therapy was delivered 10 min after the end of treatment with acupuncture, while in the C + A group, acupuncture therapy was exerted 10 min after the end of treatment with cupping. Acupuncture was applied to Mingmen (GV 4), Yaoyangguan (GV 3), ashi point and bilateral Shenshu (BL 23), Dachangshu (BL 25), Weizhong (BL 40) and Yanglingquan (GB 34), and the needles were retained for 30 min in each intervention. Flash cupping was operated along the bilateral sides of the lumbar spine for 3 min, and the cups were retained for 10 min at bilateral Shenshu (BL 23), Dachangshu (BL 25) and ashi points. The intervention was delivered once every two days, 3 times weekly, for 3 weeks totally in each group. The scores of visual analogue scale (VAS) and Oswestry disability index (ODI), TCM syndrome score and the mean temperature of the lumbar region before and after treatment were compared between the two groups. The safety and the clinical efficacy were assessed for the interventions of the two groups. RESULTS: Compared with the values before treatment, except for the sleep score of ODI, the VAS scores, ODI scores and TCM syndrome scores were decreased after treatment (P<0.01, P<0.05); while the mean temperature of the lumbar region was increased (P<0.01) in both groups. After treatment, the VAS score and the pain score of ODI in the C + A group were lower than those in the A + C group (P<0.05). The incidence rate of adverse reactions of the C + A group was lower than that of the A + C group (P<0.01). The effective rate in the A+C group was 92.1% (35/38), that in the C+A group was 94.6%(35/37), there was no statistical difference between the two groups (P>0.05). CONCLUSION: Different operation sequences between acupuncture and cupping therapy obtain the similar efficacy on lumbar muscle strain with cold and dampness, but cupping therapy delivered prior to acupuncture has certain advantages in relieving pain and improving safety.

Complementary protective effects of autophagy and oxidative response against graphene oxide toxicity in Caenorhabditis elegans.

Graphene oxide (GO) exposure may cause damage to C. elegans. However, the role of autophagy and its interactive effect with oxidative response in GO toxicity still remain largely unclear. In the present study, we investigated the protective role of autophagy against GO and its association with oxidative response using C. elegans as an in vivo system. Results indicated that GO exposure induced autophagy in a dose dependent manner in C. elegans. Autophagy inhibitor 3-methyladenine (3-MA) and silencing autophagy genes lgg-1, bec-1 and unc-51 exacerbated the toxicity of GO whereas autophagy activator rapamycin alleviated it. In addition, the antioxidant N-Acetyl-L-cysteine (NAC) effectively suppressed the toxicity of GO with increased resistance to oxidative stress. Worms with RNAi-induced antioxidative genes sod-1, sod-2, sod-3 and sod-4 knockdown were more sensitive to GO. 3-MA increased the expression of superoxide dismutase SOD-3 under GO exposure conditions and exacerbated the toxicity of GO under the anti-oxidation inaction condition by sod-3 RNAi. In contrast, NAC reduced autophagy levels in GO exposed nematodes and increased tolerance to GO in autophagy-defective worms. These results suggested that autophagy and antioxidative response provide complementary protection against GO in C. elegans.

DNMBP-AS1 Regulates NHLRC3 Expression by Sponging miR-93-5p/17-5p to Inhibit Colon Cancer Progression.

Long non-coding RNAs (LncRNAs) act as competing endogenous RNAs (ceRNAs) in colon cancer (CC) progression, via binding microRNAs (miRNAs) to regulate the expression of corresponding messenger RNAs (mRNAs). This article aims to explore the detailed molecular mechanism of ceRNA in CC. Top mad 5000 lncRNAs and top mad 5000 mRNAs were used to perform weighted gene co-expression network analysis (WGCNA), and key modules were selected. We used 405 lncRNAs in the red module and 145 mRNAs in the purple module to build the original ceRNA network by online databases. The original ceRNA network included 50 target lncRNAs, 41 target miRNAs, and 34 target mRNAs. Fifty target lncRNAs were used to establish a prognostic risk model by univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses. LncRNAs in the risk model were used to build the secondary ceRNA network, which contained 9 lncRNAs in the risk model, 35 miRNAs, and 29 mRNAs. Survival analyses of 29 mRNAs in the secondary ceRNA network have shown HOXA10 and NHLRC3 were identified as crucial prognostic factors. Finally, we constructed the last ceRNA network including 5 lncRNAs in the risk model, 8 miRNAs, and 2 mRNAs related to prognosis. Quantitative real-time polymerase chain reaction (qRT-PCR) results revealed that DNMBP-AS1 and FAM87A were down-regulated in CC cells and tissues. Function assays showed that over-expression of DNMBP-AS1 and FAM87A inhibited CC cells proliferation and migration. Mechanism study showed that DNMBP-AS1 served as miR-93-5p/17-5p sponges and relieved the suppression effect of miR-93-5p/17-5p on their target NHLRC3. Our study suggested that DNMBP-AS1 inhibited the progression of colon cancer through the miR-93-5p/17-5p/NHLRC3 axis, which could be potential therapeutic targets for CC.

Sublethal toxicity of graphene oxide in Caenorhabditis elegans under multi-generational exposure.

Nanomaterials have received increasing attentions owing to their potential hazards to the environment and human health; however, the multi-generational toxicity of graphene oxide under consecutive multi-generational exposure scenario still remains unclear. In the present study, Caenorhabditis elegans as an in vivo model organism was employed to explore the multi-generational toxicity effects of graphene oxide and the underlying mechanisms. Endpoints including development and lifespan, locomotion behaviors, defecation cycle, brood sizes, and oxidative response were evaluated in the parental generation and subsequent five filial generations. After continuous exposure for several generations, worms grew smaller and lived shorter. The locomotion behaviors were reduced across the filial generations and these reduced trends were following the impairments of locomotion-related neurons. In addition, the extended defecation cycles from the third filial generation were in consistency with the relative size reduction of the defecation related neuron. Simultaneously, the fertility function of the nematode was impaired under consecutive exposure as reduced brood sizes and oocytes numbers, increased apoptosis of germline, and aberrant expression of reproductive related genes ced-3, ced-4, ced-9, egl-1 and ced-13 were detected in exposed worms. Furthermore, the antioxidant enzyme, SOD-3 was significantly increased in the parent and filial generations. Thus, continuous multi-generational exposure to graphene oxide caused damage to the neuron development and the reproductive system in nematodes. These toxic effects could be reflected by indicators such as growth inhibition, shortened lifespan, and locomotion behavior impairment and induced oxidative response.

Indirect Regulation and Equilibrium of p35 and p40 Subunits of Interleukin (IL)-12/23 by Ustekinumab in Psoriasis Treatment.

BACKGROUND Ustekinumab, a human-derived monoclonal antibody that targets the p40 subunit of interleukin (IL)-12 and IL-23, has excellent clinical efficacy and safety in treating psoriasis, with a long half-life. However, no reports have described the use of human skin/serum samples to elucidate its molecular mechanisms. MATERIAL AND METHODS Twenty-four psoriasis patients were enrolled in our double-blind study and randomly divided into placebo and ustekinumab-administered groups. Dynamic changes in psoriasis area-severity index scores, and mRNA and protein levels of p35 and p40 were analyzed at 3 time points (before treatment and during the 12th and 24th weeks of treatment). RESULTS Ustekinumab initially increased and then decreased p35 mRNA expression, but increased p40 mRNA levels throughout the study. The p35 protein levels were not significantly altered, while p40 protein levels were increased after the first 2 injections but decreased after the third injection. CONCLUSIONS We concluded that 2 equilibria influence the efficacy of ustekinumab against psoriasis. First, because of the dual roles of p35 in psoriasis pathogenesis, homeostasis occurs between p35 and p40 expression levels. The second balance lies between the upregulation of p40 mRNA levels and the ability of ustekinumab to neutralize the function of the elevated p40 protein.

Ustekinumab treats psoriasis by suppressing RORC and T-box but its suppression of GATA restrains its efficacy

Psoriasis is a T-cell mediated disease that involves IL-23/Th17 and IL-12/Th1 axes. Ustekinumab, a fully human monoclonal antibody targeting the p40 subunit of both IL-12 and IL-23, has proven to be efficient and safe for treating patients with psoriasis. Yet, there have been no reports with human skin/blood samples that would elucidate the molecular mechanisms by which ustekinumab calms psoriasis skin lesions. To investigate the efficacy and molecular pathway (RORC, t-BOX and GATA) of ustekinumab in treating patients with psoriasis skin lesions. A total of 30 patients with psoriasis were randomized into placebo group and treatment group. PASI of each patient was calculated at 0, 12 and 24 weeks post-treatment. The mRNA levels of RORC, t-BOX and GATA in peripheral blood mononuclear cells separated from patients' whole blood were analyzed using qPCR. Decreased mRNA of RORC, t-BOX and GATA were observed after continuous injections, indicating that ustekinumab exerts its effect by interacting with these molecules; while no significant difference in foxp3 mRNA levels were found between placebo group and treatment group.

Integrated analysis of paraquat-induced microRNAs-mRNAs changes in human neural progenitor cells.

Paraquat (PQ), one of the most widely used fast-acting and non-selective herbicides in the world is believed to act as a neurotoxicant, which increases the risk of developing Parkinson's disease (PD) by selectively impairing dopaminergic neurons. However, the mechanism of PQ on neural progenitor cells remains unclear. As regulator of mRNA expression, miRNA play a crucial role in neurotoxicity. Based on our previous study, we chose 10µM PQ, which induced ROS production and inhibited proliferation but not reduced the cell viability. In this study, we present an integrative analysis of PQ-induced whole transcriptome changes and its regulatory miRNA networks in human neural progenitor cells (hNPCs). Integrated analysis of PQ-induced miRNA-mRNA alteration reveals differential expression of 3972 mRNAs and 52 miRNAs. Based on the GO analysis and pathway analysis of the intersection genes, we found 48 significantly altered GO terms and 22 significant pathways, among which, Wnt signaling being the top-ranked pathway. We verified that the expression of 9 miRNAs and 11 mRNAs related to the Wnt signaling pathway were altered in a dose-dependent manner by qPCR. These results indicate that PQ changes mRNAs and miRNAs expression in hNPCs, leading to the alteration of several neurodevelopment related key biological processes and crucial pathways, especially Wnt signaling pathway. Moreover, it suggests that PQ could downregulate Wnt signaling pathway via miRNA to induce developmental neurotoxicity.

Aphicidal Activity of Illicium verum Fruit Extracts and Their Effects on the Acetylcholinesterase and Glutathione S-transferases Activities in Myzus persicae (Hemiptera: Aphididae).

This study aims to explore the aphicidal activity and underlying mechanism of Illicium verum Hook. f. that is used as both food and medicine. The contact toxicity of the extracts from I. verum fruit with methyl alcohol (MA), ethyl acetate (EA), and petroleum ether (PE) against Myzus persicae (Sulzer), and the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs) of M. persicae after contact treatment were tested. The results showed that MA, EA, and PE extracts of 1.000 mg/l caused, respectively, M. persicae mortalities of 68.93%, 89.95% and 74.46%, and the LC50 of MA, EA, and PE extracts were 0.31, 0.14 and 0.27 mg/l at 72 h after treatment, respectively; the activities of AChE and GSTs in M. persicae were obviously inhibited by the three extracts, as compared with the control, with strong dose and time-dependent effects, the inhibition rates on the whole reached more than 50.00% at the concentration of 1.000 mg/l at 72 h after treatment. The inhibition of the extracts on AChE and GSTs activities (EA extract > PE extract > MA extract) were correlated with theirs contact toxic effects, so it is inferred that the decline of the metabolic enzymes activities may be one of important reasons of M. persicae death. The study results suggested that I. verum extracts have potential as a eco-friendly biopesticide in integrated pest management against M. persicae.

Nrf2/ARE Pathway Involved in Oxidative Stress Induced by Paraquat in Human Neural Progenitor Cells.

Compelling evidences have shown that diverse environmental insults arising during early life can either directly lead to a reduction in the number of dopaminergic neurons or cause an increased susceptibility to neurons degeneration with subsequent environmental insults or with aging alone. Oxidative stress is considered the main effect of neurotoxins exposure. In this study, we investigated the oxidative stress effect of Paraquat (PQ) on immortalized human embryonic neural progenitor cells by treating them with various concentrations of PQ. We show that PQ can decrease the activity of SOD and CAT but increase MDA and LDH level. Furthermore, the activities of Cyc and caspase-9 were found increased significantly at 10 µM of PQ treatment. The cytoplasmic Nrf2 protein expressions were upregulated at 10 µM but fell back at 100 µM. The nuclear Nrf2 protein expressions were upregulated as well as the downstream mRNA expressions of HO-1 and NQO1 in a dose-dependent manner. In addition, the proteins expression of PKC and CKII was also increased significantly even at 1 µM. The results suggested that Nrf2/ARE pathway is involved in mild to moderate PQ-induced oxidative stress which is evident from dampened Nrf2 activity and low expression of antioxidant genes in PQ induced oxidative damage.

Analysis of epithelial-mesenchymal transition markers in psoriatic epidermal keratinocytes.

Psoriasis is similar to endpoints of epithelial-mesenchymal transition (EMT), a process of epithelial cells transformed into fibroblast-like cells. The molecular epithelial and mesenchymal markers were analysed in psoriatic keratinocytes. No obvious alteration of epithelial markers E-cadherin (E-cad), keratin 10 (K10), K14 and K16 was detected in psoriatic keratinocytes. However, significantly increased expression of Vim, FN, plasminogen activator inhibitor 1 (PAI-1) and Slug was seen. IL-17A and IL-13 at 50 ng ml(-1) strongly decreased expression of K10, Vim and FN. TGF-ß1 at 50 ng ml(-1) promoted the production of N-cad, Vim, FN and PAI-1. Slug was decreased by dexamethasone (Dex), but E-cad was upregulated by Dex. Silencing of ERK partially increased E-cad and K16, but remarkably inhibited K14, FN, Vim, ß-catenin, Slug and α5 integrin. Moreover, inhibition of Rho and GSK3 by their inhibitors Y27632 and SB216763, respectively, strongly raised E-cad, ß-catenin and Slug. Dex decreased Y27632-mediated increase of ß-catenin. Dex at 2.0 µM inhibited SB216763-regulated E-cad, ß-catenin and slug. In conclusion, EMT in psoriatic keratinocytes may be defined as an intermediate phenotype of type 2 EMT. ERK, Rho and GSK3 play active roles in the process of EMT in psoriatic keratinocytes.

Involvement of pituitary tumor transforming gene 1 in psoriasis, seborrheic keratosis, and skin tumors.

Accumulating evidence suggests that pituitary tumor transforming gene 1 (PTTG1) is a potential biomarker for cancer malignancy and a cell-cycle regulatory protein. This investigation was performed to address the subcellular localization of PTTG1 and its possible involvement in proliferative skin diseases. In vitro primary-cultured keratinocytes and skin samples from psoriasis, seborrheic keratosis (SK), basal cell carcinoma (BCC), and squamous cell carcinoma (SCC) were investigated by immunofluorescence and real-time PCR. In normal skin, PTTG1 is localized predominantly in 10% of basal keratinocytes, while 30-40% in basal and suprabasal psoriatic keratinocytes. PTTG1 mRNA in psoriatic epidermis is about 5-fold more than that in normal one (P<0.01). PTTG1 is localized in cytoplasm in primary-cultured normal and psoriatic keratinocytes, and PTTG1 in HaCaT cells is distributed throughout the cytoplasm of metaphase cells. PTTG1 is seen at both G2 and M phases, and highest PTTG1 expression correlates with highest cyclin B1 expression and highest degree of nuclear pleomorphism at M phase. The positive rate of PTTG1 in SK, BCC, and SCC is about 10%, 20%, and more than 80%, respectively. PTTG1 siRNA, which knocks down the expression of PTTG1, reduced the invasive capacity of A431 cells. In conclusion, PTTG1 is a marker for proliferative skin diseases associated with cell cycle regulation and may aid in detection of aggressive cancers.

[Paraquat involves differentiation of human neural stem cells via Notch signaling].

OBJECTIVE: To investigate effects of paraquat on the mRNA expression of key elements of Notch signaling (Notch1, Jagged1 and DTX1) during differentiation process of human neural stem cells (hNSCs). METHODS: hNSCs exposed to PQ at the concentrations 0.10, 1.00, 10.00 M. Cell proliferation ability was assessed using MTT assay and mRNA expressions of Notch1, Jagged1 and DTX1 were detected by Real-time RT-PCR at 2, 4, 8, 12 d of differentiation. RESULTS: Compared with control group, NOTCH1, JAG1 mRNA expression levels exposed to PQ at the concentration of 0.10 M significantly reduced at 2, 4, 8 d and significantly went up at 12d (P < 0.01). Compared with control group, NOTCH1, JAG1 and DTX1 mRNA expression levels exposed to PQ at the concentration of 10.00 M significantly reduced at 2, 8, 12 d (P < 0.01). PQ could down-regulate Notch1, Jagged1 and DTX1 mRNA expressions at the early stage of differentiation, then up-regulate Notch1 mRNA expression, and down-regulate Notch1, Jagged1 and DTX1 mRNA expressions at the end of differentiation. CONCLUSION: Notch signaling pathway may be involved in differentiation of neural stem cell exposed to PQ.

Paraquat inhibits cell viability via enhanced oxidative stress and apoptosis in human neural progenitor cells.

Paraquat (PQ) is one of the most widely used herbicides in the world. Although available evidence indicates that people exposed to PQ have a higher risk of developing Parkinson's disease, adverse effects of PQ on neural progenitor cells have not been investigated yet. In this study, we investigated the in vitro effect of PQ on immortalized human embryonic neural progenitor cells (hNPCs) by treating them with various concentrations of PQ (0, 0.1, 1, 10 and 100 µM) for 24h. We show that PQ treatment reduces the cell viability and proliferation and induces reactive oxygen species (ROS) production in a dose-dependent manner. In addition, apoptosis induced by PQ was significantly increased at a concentration of as low as 1 µM. To illustrate the underlying molecular mechanisms, we examined the caspase-3 activity, intracellular calcium level, the NF-κB activity, as well as expression of p21, p53 and metallothionein-III mRNA. PQ significantly increased caspase-3 activity at the concentration of 100 µM. Similarly, PQ triggered intracellular Ca(2+) releases and activation of NF-κB was observed after exposure of hNPCs at low concentrations of PQ (1 µM). Meanwhile, p53 and p21 mRNA transcripts were significantly up-regulated at 10 µM and 1 µM of PQ, respectively. MT-III mRNA and protein expression was significantly up-regulated at 1 µM of PQ and reached peak at 10 µM. These results suggest that PQ could reduce viability of hNPCs by inducing oxidative stress and apoptosis.