Investigation of health literacy status and related influencing factors in military health providers of Chinese People's liberation Army, a cross-sectional study.

OBJECTIVE: The aim of this study was to investigate health literacy and analyze its influencing factors in military health providers of the Chinese People's Liberation Army (PLA Army). METHODS: From November to December 2018, cluster sampling was used to select 1512 military health providers from the Army Medical University. Health literacy was measured by using the Chinese Citizen Health Literacy Questionnaire (HLQ) (2015 edition). Influencing factors that may affect health literacy were assessed using the chi-square test and multivariate logistic regression models. RESULTS: The knowledge rate of health literacy was relatively low (21.6%). The knowledge rate of health-related skills (HRS, 18.7%) was the lowest of the three aspects of health literacy, and the knowledge rate of chronic diseases (CD, 19.6%) was the lowest of the six dimensions of health literacy. Participants who were older, were female, were of Han ethnicity, were the only child in their families, came from urban areas, never used tobacco, and had higher household income were likely to have higher health literacy. CONCLUSION: The health literacy levels of military health providers of the PLA Army are relatively low. Further research and health education are necessary to improve health literacy.

Low-dose microcystin-LR antagonizes aflatoxin B1 induced hepatocarcinogenesis through decreasing cytochrome P450 1A2 expression and aflatoxin B1-DNA adduct generation.

Aflatoxin B1 (AFB1) and microcystin-LR (MC-LR) co-existed in food and water, and were associated with hepatocellular carcinoma (HCC). AFB1 induced HCC by activating oxidative stress and generating AFB1-DNA adducts, while MC-LR could promote HCC progression. However, whether they have co-effects in HCC progression remains uncertain. In this study, we found the antagonistic effects of MC-LR on AFB1 induced HCC when they were exposed simultaneously. Compared with single exposure to AFB1, co-exposed to MC-LR significantly repressed the AFB1 induced malignant transformation of human hepatic cells and the glutathione S-transferase Pi positive foci formation in rat livers. MC-LR inhibited AFB1 induced upregulation of cytochrome P450 family 1 subfamily A member 2 (CYP1A2) and reduced the AFB1-DNA adducts generation in both human hepatic cells and rat livers. These results suggest that when co-exposure with AFB1, MC-LR might repress hepatocarcinogenicity of AFB1, which might be associated with its repression on AFB1 induced CYP1A2 upregulation and activation.

Epigenetic inactivation of LHX6 mediated microcystin-LR induced hepatocarcinogenesis via the Wnt/ß-catenin and P53 signaling pathways.

Microcystins (MCs) have been shown to be carcinogenic by animal and cellular experiments and found to be associated with the development of human hepatocellular carcinoma (HCC) through epidemiological studies. However, the molecular mechanism of microcystin-LR (MC-LR) induced HCC is still unclear. This study is determined to clarify the role and mechanism of LHX6 in MC-LR-induced hepatocarcinogenesis. Using the previously established MC-LR-induced malignant transformation model in L02 cells, we screened out LHX6, homeobox gene that was significantly changed. We found that LHX6 was significantly down-regulated in MC-LR treated L02 cells and the liver tissue of rats treated for 35 weeks with 10 µg/kg body weight of MC-LR. Expression of LHX6 in human tumor tissue was significantly down-regulated in high MC-LR-exposure group. LHX6 was hypermethylated in MC-LR treated L02 cells and up-regulated after treatment with 10 µM of 5-aza-2'-deoxycytidine. Furthermore, overexpression of LHX6 inhibited proliferation, invasion and migration of malignantly transformed L02 cells in vitro and in vivo, while knockdown of LHX6 resulted in an opposite phenotype. In addition, we found that up-regulation of P53 and Bax resulted in apoptosis, and that down-regulation of CTNNB1 and MMP7 led to migration of MC-LR treated L02 cells. Blockade of P53 and CTNNB1 by its inhibitor significantly diminished the effect of LHX6. These genes were working together during the process of MC-LR-induced hepatocarcinogenesis. Our study demonstrated for the first time that LHX6 gene expression is regulated by DNA methylation and can inhibit the proliferation, invasion and migration through Wnt/ß-catenin and P53 signaling pathways during the MC-LR-induced hepatocarcinogenesis. This result may suggest that LHX6 gene can be used as a potential target gene and a biomarker for liver cancer treatment.

Epigenetic silencing of ALX4 regulates microcystin-LR induced hepatocellular carcinoma through the P53 pathway.

Recent studies have shown that microcystin-LR (MC-LR) is one of the principal factors that cause liver cancer. Previously we have found that Aristaless-like Homeobox 4 (ALX4) was differentially expressed in MC-LR-induced malignant transformed L02 cells. However, the expression regulation, role and molecular mechanism of ALX4 during the process of liver cancer induced by MC-LR are still unclear. The expression of ALX4 was detected by quantitative reverse-transcription PCR and Western blot in MC-LR induced malignantly transformed cell and rat models. Methylation status of ALX4 promoter region was evaluated by methylation-specific PCR and bisulfite genomic sequencing. The anti-tumor effects of ALX4 on MC-LR induced liver cancer were identified in vitro and in vivo. ALX4 expression was progressively down-regulated in MC-LR-induced malignantly transformed L02 cells and the MC-LR exposed rat models. ALX4 promoter regions were highly methylated in malignantly transformed cells, while treatment with demethylation agent 5-aza-dC significantly increased ALX4 expression. Functional studies showed that overexpression of ALX4 inhibits cell proliferation, migration, invasion and metastasis in vitro and in vivo, blocks the G1/S phase and promotes the apoptosis. Conversely, knockdown of ALX4 promotes cell proliferation, migration and invasion. Mechanism study found that ALX4 exerts its antitumor function through the P53 pathway, C-MYC and MMP9. More importantly, ALX4 expression level showed a negative relation with serum MC-LR levels in patients with hepatocellular carcinoma. Our results suggested that ALX4 was inactivated by DNA methylation and played a tumor suppressor function through the P53 pathway in MC-LR induced liver cancer.

Chronic Microcystin-LR Exposure Induces Hepatocarcinogenesis via Increased Gankyrin in Vitro and in Vivo.

BACKGROUND/AIMS: Our recent study indicated that the serum microcystin-LR (MC-LR) level is positively linked to the risk of human hepatocellular carcinoma (HCC). Gankyrin is over-expressed in cancers and mediates oncogenesis; however, whether MC-LR induces tumor formation and the role of gankyrin in this process is unclear. METHODS: We induced malignant transformation of L02 liver cells via 35 passages with exposure to 1, 10, or 100 nM MC-LR. Wound healing, plate and soft agar colony counts, and nude mice tumor formation were used to evaluate the tumorigenic phenotype of MC-LR-treated cells. Silencing gankyrin was used to confirm its function. We established a 35-week MC-LR exposure rat model by twice weekly intraperitoneal injection with 10 µg/kg body weight. In addition, 96 HCC patients were tested for tumor tissue gankyrin expression and serum MC-LR levels. RESULTS: Chronic low-dose MC-LR exposure increased proliferation, mobility, clone and tumor formation abilities of L02 cells as a result of gankyrin activation, while silencing gankyrin inhibited the carcinogenic phenotype of MC-LR-treated cells. MC-LR also induced neoplastic liver lesions in Sprague-Dawley rats due to up-regulated gankyrin. Furthermore, a trend of increased gankyrin was observed in humans exposed to MC-LR. CONCLUSION: These results suggest that MC-LR induces hepatocarcinogenesis in vitro and in vivo by increasing gankyrin levels, providing new insight into MC-LR carcinogenicity studies.

Microcystin-LR increases genotoxicity induced by aflatoxin B1 through oxidative stress and DNA base excision repair genes in human hepatic cell lines.

Aflatoxin B1 (AFB1) and microcystin-LR (MC-LR) simultaneously exist in polluted food and water in humid and warm areas, and each has been reported to be genotoxic to liver and associated with hepatocellular carcinoma (HCC). However, the genotoxic effects of the two biotoxins in combination and potential mechanism remain unknown. We treated the human hepatic cell line HL7702 with AFB1 and MC-LR together at different ratios, examined their genotoxic effects using micronuclei and comet assays, and evaluated the possible mechanism by measuring oxidative stress markers and DNA base excision repair (BER) genes. Our data show that co-exposure to AFB1 and MC-LR significantly increased DNA damage compared with AFB1 or MC-LR alone as measured by the levels of both micronuclei and tail DNA. Meanwhile, AFB1 and MC-LR co-exposure showed biphasic effects on ROS production, and a gradual trend towards increased Glutathione (GSH) levels and activity of Catalase (CAT) and Superoxide Dismutase (SOD). Furthermore, MC-LR, with or without AFB1, significantly down-regulated the expression of the base excision repair (BER) genes 8-oxoguanine glycosylase-1 (OGG1) and X-ray repair cross complementing group 1 (XRCC1). AFB1 and MC-LR in combination upregulated the expression of the BER gene apurinic/apyrimidinic endonuclease 1 (APE1), whereas either agent alone had no effect. In conclusion, our studies show that MC-LR exacerbates AFB1-induced genotoxicity and we report for the first time that this occurs through effects on oxidative stress and the deregulation of DNA base excision repair genes.

Interaction Effects of AFB1 and MC-LR Co-exposure with Polymorphism of Metabolic Genes on Liver Damage: focusing on SLCO1B1 and GSTP1.

AFB1 and MC-LR are two major environmental risk factors for liver damage worldwide, especially in warm and humid areas, but there are individual differences in health response of the toxin-exposed populations. Therefore, we intended to identify the susceptible genes in transport and metabolic process of AFB1 and MC-LR and find their effects on liver damage. We selected eight related SNPs that may affect liver damage outcomes in AFB1 and MC-LR exposed persons, and enrolled 475 cases with liver damage and 475 controls of healthy people in rural areas of China. The eight SNPs were genotyped by PCR and restriction fragment length polymorphism. We found that SLCO1B1 (T521C) is a risk factor for liver damage among people exposed to high AFB1 levels alone or combined with MC-LR, and that GSTP1 (A1578G) could indicate the risk of liver damage among those exposed to high MC-LR levels alone or combined with high AFB1 levels. However, GSTP1 (A1578G) could reduce the risk of liver damage in populations exposed to low MC-LR levels alone or combined with high AFB1 levels. In conclusion, SLCO1B1 (T521C) and GSTP1 (A1578G) are susceptible genes for liver damage in humans exposed to AFB1 and/or MC-LR in rural areas of China.

Prevalence of metabolic syndrome among adults with liver function injury in rural area of Southwest China: A cross-sectional study.

Abnormal liver function (ALF) plays a key role in metabolic syndrome (MetS), but only few data on the relationship between MetS and the risk factors for ALF (e.g., biotoxins) are available. We aimed to provide the prevalence of MetS and its association with the risk factors for ALF in rural area of Southwest China. A cross-sectional study within the hepatocellular carcinoma cohort was conducted, and included 5493 people with age from 30 to 85 years old. MetS was defined according to the Joint Scientific Statement. We observed that the prevalence of MetS was 31.8% (39.0% in women and 19.8% in men). Logistic regression analysis showed that significantly increased risk of MetS was found in those showing ALF (OR = 3.00, 95% CI: 2.43-3.71). Significantly decreased risk of MetS was found in those with higher HBV DNA titers (OR = 0.49, 95% CI: 0.33-0.74), and in those with higher aflatoxin B1 exposure (estimated daily intake, EDI) (OR = 0.60, 95% CI: 0.53-0.67). No significant change was found in those with higher microcystin-LR exposure (EDI). Therefore, the different risk factors for ALF might exert different effects on MetS. However, there should be an interaction effect existing that might decide the severity of MetS.

Serum microcystin levels positively linked with risk of hepatocellular carcinoma: A case-control study in southwest China.

Microcystins have been reported to be carcinogenic by animal and cell experimentation, but there are no data on the linkage between serum microcystins and hepatocellular carcinoma (HCC) risk in humans. We conducted a clinical case-control study to investigate the association between serum microcystins and HCC risk after controlling several known risk factors, such as hepatitis B virus, alcohol, and aflatoxin. From December 2013 to May 2016, 214 patients newly diagnosed with HCC along with 214 controls (frequency-matched by age and sex) were recruited from three hospitals in Chongqing, southwest China. Basic information on lifestyle and history of disease was obtained by questionnaire. Blood samples were collected and analyzed for serum microcystin-LR (MC-LR) and aflatoxin-albumin adduct by enzyme-linked immunosorbent assay and for hepatitis B surface antigen status by chemiluminescence assay. Binary logistic regression analyses were performed to assess the independent effects of MC-LR and its joint effects with other factors on HCC risk. The adjusted odds ratio for HCC risk by serum MC-LR was 2.9 (95% confidence interval [CI], 1.5-5.5) in all patients. Notably, a clear relationship between increased MC-LR level (Q2, Q3, and Q4) and HCC risk was observed with elevated adjusted odds ratios (1.3, 2.6, and 4.0, respectively). Positive interactions with the additive model were investigated between MC-LR and hepatitis B virus infection (synergism index = 3.0; 95% CI, 2.0-4.5) and between MC-LR and alcohol (synergism index = 4.0; 95% CI, 1.7-9.5), while a negative interaction was found between MC-LR and aflatoxin (synergism index = 0.4; 95% CI, 0.3-0.7). Additionally, serum MC-LR was significantly associated with tumor differentiation (r = -0.228, P < 0.001). CONCLUSION: We provide evidence that serum MC-LR was an independent risk factor for HCC in humans, with an obvious positive interaction with hepatitis B virus and alcohol but a negative interaction with aflatoxin. (Hepatology 2017;66:1519-1528).

Environmental Microcystin Exposure Increases Liver Injury Risk Induced by Hepatitis B Virus Combined with Aflatoxin: A Cross-Sectional Study in Southwest China.

Three liver hazards, two confirmed-hepatitis B virus (HBV) and aflatoxin (AFB), and one rarely studied in populations-microcystin (MC), simultaneously exist in tropical and humid areas; however, there are no epidemiological data on their risks in the same population. We conducted a community-based cross-sectional survey among 5493 adults in two rural towns and statistically analyzed the comparative and combinative effects of the three factors after detecting HBsAg and HBV DNA titers, determining estimated daily intakes (EDIs) of AFB1 and MC-LR and testing serum AST and ALT as liver injury markers for each participant. We observed a HBsAg(+) rate of 7.6%, a relatively high AFB1 exposure level (mean EDIAFB1 = 471.30 ng/d), and a relatively low MC-LR exposure level (mean EDIMC-LR = 228.25 ng/d). ORs for abnormal AST (2.42, 95%CI = 1.69-3.45) and ALT (2.87, 95%CI = 1.91-4.29) increased in HBV infections compared with HBV-unexposed participants but did not increase in participants with separate or combined exposure to AFB1 and MC-LR (EDIs ≥ mean). Meanwhile, after adjustment for confounding factors, means of AST and ALT and ORs of abnormal AST and ALT were successively elevated after exposure to HBV, HBV&AFB1 (or HBV&MC-LR), and HBV&AFB1&MC-LR, especially in the group with detectable HBV DNA (AST: OR = 11.38, 95%CI = 3.91-33.17; ALT: OR = 17.09, 95%CI = 5.36-54.53). Notably, ORs for abnormal AST and ALT in the HBV exposed group were not significantly different from those in HBV&AFB1 or in the HBV&MC-LR exposed group but were significantly higher in the HBV&AFB1&MC-LR exposed group (P = 0.029 and P = 0.037, respectively). Our study indicated that microcystin may have the potential to increase the risk of liver injury induced by combined exposure to HBV and aflatoxin. However, in consideration of the uncertainties in the detection of the toxins and evaluation of the EDIs, more epidemiological data are expected to determine the increasing toxic effects of microcystins.

Determination of Environmental Exposure to Microcystin and Aflatoxin as a Risk for Renal Function Based on 5493 Rural People in Southwest China.

Although the nephrotoxicity of microcystin and aflatoxin has been observed in animal and clinical cases, few population data are available. We conducted a cross-sectional study in Southwest China to investigate the association of renal function indicators (RFIs, including BUN, SCr, and eGFR) with exposure to microcystin and aflatoxin in 5493 members of the general population. Microcystin-LR levels in water and aquatic products and aflatoxin B1 levels in daily foods were measured by ELISA, and individual estimated daily intake (EDI) was assessed on the basis of the measurement and questionnaire. We found that participants with abnormal RFIs had a much higher mean level of microcystin-LR EDI than those with normal RFIs and that there was a significant increasing trend for abnormal rates and odds ratios of RFIs with increasing microcystin-LR EDI quartiles (p for trend = 0.000). Compared with the lowest quartile of microcystin-LR exposure, those in the highest quartile had significantly higher risks of abnormal BUN (OR = 1.80, 95% CI = 1.34-2.42), SCr (OR = 4.58, 95% CI = 2.92-7.21), and eGFR (OR = 4.41, 95% CI = 2.55-7.63), respectively, but no higher risk was found in subjects with higher AFB1 exposure. After adjustment for confounding factors, risk associations with microcystin-LR persisted. Consequently, our results suggest that microcystin, rather than aflatoxin, might be one important risk of renal-function impairment.