MMP12 is a Potential Predictive and Prognostic Biomarker of Various Cancers Including Lung Adenocarcinoma

OBJECTIVE

This study sought to explore the clinical value of matrix metalloproteinases 12 (MMP12) in multiple cancers, including lung adenocarcinoma (LUAD).

METHODS

Using >10,000 samples, this retrospective study demonstrated the first pan-cancer analysis of MMP12. The expression of MMP12 between cancer groups and their control groups was analyzed using Wilcoxon rank-sum tests. The clinical significance of MMP12 expression in multiple cancers was assessed using receiver operating characteristic curves, Kaplan-Meier curves, and univariate Cox analysis. A further LUAD-related analysis based on 4565 multi-center and in-house samples was performed to verify the findings regarding MMP12 in pan-cancer analysis partly.

RESULTS

MMP12 mRNA is highly expressed in 13 cancers compared to their controls, and the MMP12 protein level is elevated in some of these cancers (e.g., colon adenocarcinoma) (P < .05). MMP12 expression makes it feasible to distinguish 21 cancer tissues from normal tissues (AUC = 0.86). A high MMP12 expression is a prognosis risk factor in eight cancers, such as adrenocortical carcinoma (hazard ratio >1, P < .05). The elevated MMP12 expression is also a prognosis protective factor in breast-invasive carcinoma and colon adenocarcinoma (hazard ratio <1, P < .05). Some pan-cancer findings regarding MMP12 are verified in LUAD-MMP12 expression is upregulated in LUAD at both the mRNA and protein levels (P < .05), has the potential to distinguish LUAD with considerable accuracy (AUC = .91), and plays a risk prognosis factor for patients with the disease (P < .05).

CONCLUSIONS

MMP12 is highly expressed in most cancers and may serve as a novel biomarker for the prediction and prognosis of numerous cancers.

[A case of metastatic breast cancer complicated by pulmonary tumor thrombotic microangiopathy]

Pulmonary tumor thrombotic microangiopathy is a malignancy-related complication with rapid progression and high mortality. To improve the understanding of the disease, early diagnosis and treatment are key to successful treatment. A 39-year-old patient with pulmonary hypertension transferred from another hospital was admitted to the First Affiliated Hospital of Guangzhou Medical University on September 26, 2021. The patient developed shortness of breath and progressive exacerbation over the past month. No pulmonary artery embolism was seen on computed tomography pulmonary angiography (CTPA) at the outside hospital where the breast cancer was diagnosed. Pulmonary tumor thrombotic microangiopathy was immediately considered on admission and oncological endocrine therapy was started. After treatment, the patient's dyspnoea improved, PET-CT showed significant tumor regression, and cardiac ultrasound showed a significant decrease in pulmonary artery pressure. The successful treatment experience of this case was summarized for reference.

[Review and perspective of clinical research involving chest tightness variant asthma in China]

Chest tightness variant asthma (CTVA) was first reported and named by Chinese scholars in 2013. It is a new clinical type of asthma characterized by chest tightness as the only or primary symptom, without typical asthma manifestations such as recurrent wheezing and shortness of breath, and without wheezing sounds heard during lung auscultation. The overall epidemiological data on CTVA is currently unavailable. Its pathogenesis is similar to that of typical asthma, involving eosinophilic airway inflammation. Due to the lack of typical clinical manifestations, insufficient knowledge of this disease in some clinicians and some other reasons, CTVA is susceptible to misdiagnosis or missed diagnosis. Currently, the diagnostic criteria for CTVA are: chest tightness as the only or primary symptom, without typical asthma symptoms and signs such as wheezing and shortness of breath, and with any one of the objective indicators of variable airflow limitation. Effective anti-asthma treatment is required, and other diseases that cause chest tightness, such as cardiovascular, digestive, nervous, muscular, and mental diseases should be excluded. CTVA treatment follows that of typical asthma, but the specific treatment duration is uncertain and may require long-term management. Traditional Chinese medicine has shown some therapeutic effects on CTVA. Most CTVA patients have a good prognosis after active anti-asthma treatment. This paper analyzes and summarizes the research of CTVA in China from 2013 and provides new perspectives for further exploration of CTVA.

[Investigation on cognition, diagnosis and treatment status of chest tightness variant asthma among Chinese pediatricians]

Objective: To evaluate the awareness, diagnosis and treatment of chest tightness variant asthma (CTVA) among pediatricians in China. Methods: The survey was conducted by convenient sampling method. Pediatricians with professional title of attending physician and above from different grades hospitals in 30 provinces were invited to conduct online questionnaire surveys through WeChat, pediatricians scan QR codes to complete electronic questionnaires in the mini program from January 16th to February 4th, 2021. The contents of questionnaire included the awareness, diagnosis and treatment of CTVA, and comparing the differences between pediatricians in secondary hospitals and tertiary hospitals. Results: A total of 1 529 pediatricians participated in the survey, and 1 484 (97.06%) pediatricians completed the questionnaire and included in the analysis, including 420 males (28.30%). The awareness rate of CTVA among pediatricians was 77.83 % (1 155/1 484). Pediatricians in tertiary hospitals had higher rates of awareness of CTVA than pediatricians in secondary hospitals [81.86% (898/1 097) vs 66.41% (257/387), P<0.001] and had better execution of the guidelines [89.15% (978/1 097) vs 79.59% (308/387), P<0.001]. A total of 93.06 % (1 381/1 484) of pediatricians' first-line treatment included inhaled corticosteroids (ICS) for CTVA. Among them, a higher proportion of pediatricians in tertiary hospitals used ICS included regimens for first-line treatment of CTVA compared with pediatricians in secondary hospitals [94.90% (1 041/1 097) vs 87.86% (340/387), P<0.001]. The reported well control rate of CTVA was 32.08% (476/1 484), which was significantly lower in secondary hospitals than that in tertiary hospitals [17.31% (67/387) vs 37.28% (409/1 097), P<0.001]. Conclusion: Most pediatricians are well aware of CTVA, among which there is a certain gap in clinical practice between pediatricians in secondary hospitals and tertiary hospitals in terms of understanding, diagnosis, and treatment of CTVA.

LPCAT1 enhances the invasion and migration in gastric cancer: Based on computational biology methods and in vitro experiments

BACKGROUND AND AIM

The biological functions and clinical implications of lysophosphatidylcholine acyltransferase 1 (LPCAT1) remain unclarified in gastric cancer (GC). The aim of the current study was to explore the possible clinicopathological significance of LPCAT1 and its perspective mechanism in GC tissues.

MATERIALS AND METHODS

The protein expression and mRNA levels of LPCAT1 were detected from in-house immunohistochemistry and public high-throughput RNA arrays and RNA sequencing. To have a comprehensive understanding of the clinical value of LPCAT1 in GC, all enrolled data were integrated to calculate the expression difference and standard mean difference (SMD). The biological mechanism of LPCAT1 in GC was confirmed by computational biology and in vitro experiments. Migration and invasion assays were also conducted to confirm the effect of LPCAT1 in GC.

RESULTS

Both protein and mRNA expression levels of LPCAT1 in GC were remarkably higher than those in noncancerous controls. Comprehensively, the SMD of LPCAT1 mRNA was 1.11 (95% CI = 0.86-1.36) in GC, and the summarized AUC was 0.85 based on 15 datasets containing 1727 cases of GC and 940 cases of non-GC controls. Moreover, LPCAT1 could accelerate the invasion and migration of GC by boosting the neutrophil degranulation pathway and disturbing the immune microenvironment.

CONCLUSION

An increased level of LPCAT1 may promote the progression of GC.

[Annual progress in treatment of bronchial asthma 2022]

Bronchial asthma is one of the most common chronic inflammatory airway diseases. Its incidence is increasing annually worldwide, posing a heavy medical burden to society and individuals. At the same time, continuous improvement has been made in the diagnosis and treatment strategies of asthma. With the advancement of basic research and the emergence of evidence-based evidence on asthma, new drugs, updated ideas and strategies have appeared in the field of asthma treatment. This article reviewed the progress and achievements in the field of asthma treatment from 1^st October 2021 to 30^th September 2022, as well as several updated guidelines and consensus guidance on asthma, providing clinical perspective for the treatment of asthma.

[Development of a risk assessment scale and test of its validity and reliability for venous thromboembolism in adult burn patients]

Objective: To develop a venous thromboembolism (VTE) risk assessment scale for adult burn patients and to test its reliability and validity. Methods: The scale research method and multi-center cross-sectional survey method were used. Based on the results of literature analysis method and brain-storming method, the letter questionnaire for experts was formulated. Then 27 experts (9 doctors of burn department, 9 vascular surgeons, and 9 nurses) were performed with two rounds of correspondences by Delphi method, and the reliability of the experts was analyzed. The weight of each item was determined by optimal sequence diagram method and expert importance evaluation to form the VTE Risk Assessment Scale for Adult Burn Patients. A total of 223 adult burn inpatients, who were admitted to 5 tier Ⅲ grade A general hospitals including the Affiliated Hospital of Southwest Medical University, West China Hospital of Sichuan University, the Affiliated Hospital of North Sichuan Medical College, Nanchong Central Hospital, and the Second People's Hospital of Yibin City from October 1st 2019 to January 1st 2020, were selected as respondents by convenience sampling method. The first assessment was performed with the VTE Risk Assessment Scale for Adult Burn Patients within 24 hours of admission of patients, and real-time assessment was performed as the patients' condition and treatment changed. The highest value was taken as the result. Correlation coefficient method and critical ratio method were used for item analysis; Cronbach's α coefficient was used to test the internal consistency of scale; content validity index was used to analyze the content validity of the scale, and receiver's operating characteristic (ROC) curve was drawn to test the predictive validity of the scale. Data were statistically analyzed with chi-square test, Pearson correlation analysis, independent sample t test, and Z test. Results: As four questionnaires in the first round of correspondence were rejected as unqualified, and another 4 experts were selected for the 2 rounds of correspondence. Most of them were aged 41 to 50 years with postgraduate degrees, engaging in the current profession for 11 to 30 years, and all of them had professional titles of associate senior or above. The scale, constructed through literature analysis, group brainstorming, and two rounds of correspondence, includes 3 primary items and 50 secondary items. In the first round of correspondence, the recovery rate of valid questionnaires and the ratio with expert opinions were 85.2% (23/27) and 47.8% (11/23), respectively. In the second round of correspondence, the recovery rate of valid questionnaires and the ratio with expert opinions were 100% (27/27) and 11.1% (3/27), respectively. The average collective authority coefficients of experts were both 0.90 in the 2 rounds of correspondence. The mean values of importance assignment, full score rate, and selection rate above 4 were 4.21, 52.5%, and 77.2%, respectively, in the first round of correspondence, and 4.28, 45.2%, and 85.8%, respectively, in the second round of correspondence. The mean coefficients of variation and the mean value of Kendall's coefficient of harmony for each item were 0.21 and 0.30 in the first round of correspondence, respectively, and 0.16 and 0.36 in the second round of correspondence, respectively. In the first and second rounds of correspondence, the Kendall's coefficients of harmony of 3 primary items (age and underlying diseases, burn injury factors, and burn treatment factors) and total secondary items were statistically significant (with χ2 values of 121.46, 107.09, 116.00, 331.97, 169.97, 152.12, 141.54, and 471.70, P<0.01). The weights of primary items for age and underlying diseases, burn injury factors, and burn treatment factors were 0.04, 0.05, and 0.07, respectively. The weights of secondary items ranged from 0.71 to 0.99, with assigned values of 3 to 6. The total burn area of 223 patients ranged from 1% to 89% total body surface area, and the patients were aged from 19 to 96 years, with the risk assessment score from 0 to 98. Nine patients developed VTE, with a risk assessment score of 41 to 90. The scores of 37 items were significantly positively correlated with the total score of scale (with r values of 0.14 to 0.61, P<0.05 or P<0.01), and the items were retained. There were 36 secondary items with statistically significant differences between the patients in high-score group and low-score group (with Z values of -4.88 to -2.09, t values of -11.63 to -2.09, P<0.05 or P<0.01), and the items were retained. The total Cronbach's α coefficient of scale was 0.88. The total content validity index of scale was 0.95. The optimal threshold of the scale for the diagnosis of VTE was 40, at which the sensitivity was 88.9%, the specificity was 87.4%, the Youden index was 0.87, and the area under the ROC curve was 0.96 (with 95% confidence interval of 0.93 to 0.99, P<0.01). Conclusions: The age and underlying diseases, burn injury factors, and burn treatment factors are the risk factors for VTE in adult burn patients. The VTE risk assessment scale for adult burn patients developed based on these factors has good reliability and validity, and provide good reference value for clinical VTE risk assessment.

Upregulation of the transmembrane protease serine 3 mRNA level in radioresistant colorectal cancer tissues

Aim: To investigate the clinical role of transmembrane protease serine 3 (TMPRSS3) in radioresistance and prognosis of colorectal cancer (CRC). Methods: Standardized mean difference (SMD) and summary area under the curve (AUC) of TMPRSS3 were calculated by combining all available high-throughput data globally. The prognostic significance of TMPRSS3 was determined by Kaplan-Meier and Cox regression analyses. Results: TMPRSS3 was remarkably upregulated in 198 CRC radioresistant cases compared with nonradioresistance (SMD = 0.38, AUC = 0.71). Overexpression of TMPRSS3 was observed in 1601 CRC patients compared with control subjects without CRC. TMPRSS3 was a risk factor for disease-free survival of CRC with the summarized hazard ratio 1.28. Conclusion: TMPRSS3 contributes to the radioresistance and unfavorable prognosis of CRC.

Active Enhancer Assessment by H3K27ac ChIP-seq Reveals Claudin-1 as a Biomarker for Radiation Resistance in Colorectal Cancer

Background

Colorectal cancer (CRC) represents the third most common malignant tumor in the worldwide. Radiotherapy is the common therapeutic treatment for CRC, but radiation resistance is often encountered. ChIP-seq of Histone H3K27 acetylation (H3K27ac) has revealed enhancers that play an important role in CRC. This study examined the relationship between an active CRC enhancer and claudin-1 (CLDN1), and its effect on CRC radiation resistance.

Methods

The target CRC genes of active enhancers were obtained from public H3K27ac ChIP-seq, and the genes highly expressed in radio-resistant CRC were screened and intersected with enhancer-driven genes. The clinical roles of CLDN1 in radiation resistance were examined using the t-test, standard mean deviation (SMD), summary receiver operating characteristic curve and Kaplan-Meier curves. The co-expressed genes of CLDN1 were calculated using Pearson Correlation analysis, and Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes and Gene Set Variation Analysis (GSVA) analyses were used to examine the molecular mechanisms of CLDN1.

Results

Total 13 703 CRC genes were regulated by enhancers using 58 H3K27ac ChIP-seq. Claudin-1 (CLDN1) was enhancer-driven and notably up-regulated in CRC tissues compared to non-CRC controls, with a SMD of 3.45 (95 CI % = .56-4.35). CLDN1 expression was increased in radiation-resistant CRC with a SMD of .42 (95% CI = .16-.68) and an area under the curve of .74 (95% CI = .70-.77). The cell cycle and immune macrophage levels were the most significant pathways associated with CLDN1.

Conclusion

CLDN1 as an enhancer-regulated gene that can boost radiation resistance in patients with CRC.

BCAT1: A risk factor in multiple cancers based on a pan-cancer analysis

Background

Although branched chain amino acid transaminase 1 (BCAT1) has been identified to play an essential role in multiple tumors, no studies on its role in pan‐cancer have been consulted before.

Methods

The study comprehensively analyzes the expression, potential mechanisms, and clinical significance of BCAT1 in pan‐cancer through utilizing 16,847 samples, providing novel clues for the treatment of cancers. A Kruskal–Wallis test and the Wilcoxon rank‐sum and signed‐rank tests were applied to investigate diverse BCAT1 expression between various groups (e.g., cancer tissues versus normal tissues). Spearman’s rank correlation coefficient was used in all correlation analyses in the study. Cox analyses and Kaplan‐Meier curves were utilized to identify the prognosis significance of BCAT1 expression in cancers. The significance of BCAT1 expression in differentiating cancer and non‐cancer tissues was explored via the area under the receiver operating characteristic curves (AUC).

Results

The differential expression of BCAT1 was detected in various cancers (p < 0.05), which is relevant to some DNA methyltransferases expression. BCAT1 expression was associated with mismatch repair gene expression, immune checkpoint inhibitors expression, microsatellite instability, and tumor mutational burden in some cancers, indicating its potential in immunotherapy. BCAT1 expression showed prognosis significance and played a risk role in multiple cancers (hazard ratio > 0, p < 0.05). BCAT1 expression also demonstrated conspicuous ability to distinguish some cancers tissues from their normal tissues (AUC > 0.7), indicating its potential to detect cancers. Further analyses on head and neck squamous cell carcinoma certified upregulated BCAT1 expression at both mRNA and protein levels in this disease based on in‐house tissue microarrays and multicenter datasets.

Conclusions

For the first time, the research comprehensively demonstrates the overexpression of BCAT1 in pan‐cancer, which improves the understanding of the pathogenesis of BCAT1 in pan‐cancer. Upregulated BCAT1 expression represented a poor prognosis for cancers patients, and it serves as a potential marker for cancer immunotherapy.

[Outcome of radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type]

Objective: To evaluate the prognosis and determine the failure patterns after radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type (ENKTCL). Methods: A total of 557 patients from 2000-2015 with low-risk early-stage ENKTCL who received radiotherapy (RT) with or without chemotherapy (CT) from China Lymphoma Collaborative Group were retrospectively reviewed. Among them, 427 patients received combined modality therapy, whereas 130 patients received RT alone. Survivals were calculated by Kaplan-Meier method and compared with Log-rank test. Overall survival (OS) was compared with age and sex-matched general Chinese population using expected survival and standardized mortality ratio (SMR). Cox stepwise regression model was used for multivariate analysis. Results: The 5-year OS and progression-free survival (PFS) were 87.2% and 77.2%. The SMR was 3.59 (P<0.001) at 1 year after treatment, whereas it was 1.50 at 4 years after treatment, without significant difference between ENKTCL group and country-matched general population (P=0.146). Compared with RT alone, CMT did not result in significantly superior 5-year OS (87.0% vs 87.4%, P=0.961) or PFS (76.1% vs 80.7%, P=0.129). Local failure (11.5%, 64/557) and distant failure (10.8%, 60/557) were the main failure modes, while regional failure was rare (2.9%, 16/557). The 5-year locoregional control rate (LRC) was 87.2% for the whole group, with 89.5% for ≥50 Gy versus 73.7% for <50 Gy (P<0.001). Radiotherapy dose was an independent factor affecting LRC(P<0.05). Conclusions: Radiotherapy achieves a favorable prognosis in patients with low-risk early-stage ENKTCL. The incidence of either locoregional or distant failure is low. Radiation dose still is an important prognostic factor for LRC.

Association of improved overall survival with decreased distant metastasis following asparaginase-based chemotherapy and radiotherapy for intermediate- and high-risk early-stage extranodal nasal-type NK/T-cell lymphoma: a CLCG study

BACKGROUND

This study evaluated the survival benefit of asparaginase (ASP)-based versus non-ASP-based chemotherapy combined with radiotherapy in a real-world cohort of patients with early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL).

PATIENTS AND METHODS

We identified 376 patients who received combined radiotherapy with either ASP-based (ASP, platinum, and gemcitabine; n = 286) or non-ASP-based (platinum and gemcitabine; n = 90) regimens. The patients were stratified into low-, intermediate-, and high-risk groups using the early stage-adjusted nomogram-revised risk index. Overall survival (OS) and distant metastasis (DM)-free survival (DMFS) between the chemotherapy regimens were compared using inverse probability of treatment weighting (IPTW) and multivariable analyses.

RESULTS

ASP-based (versus non-ASP-based) regimens significantly improved 5-year OS (84.5% versus 73.2%, P = 0.021) and DMFS (84.4% versus 74.5%, P = 0.014) for intermediate- and high-risk patients, but not for low-risk patients in the setting of radiotherapy. Moreover, ASP-based regimens decreased DM, with a 5-year cumulative DM rate of 14.9% for ASP-based regimens compared with 25.1% (P = 0.014) for non-ASP-based regimens. The survival benefit of ASP-based chemotherapy and radiotherapy remained consistent after adjusting the confounding variables using IPTW and multivariate analyses; additional sensitivity analyses confirmed these results.

CONCLUSIONS

The findings provided support for ASP-based chemotherapy and radiotherapy as a first-line treatment strategy for intermediate- and high-risk early-stage ENKTCL.

Down-regulation of microRNA-125b-2-3p is a risk factor for a poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of mortality in cancer patients, but the association between miR-125b-2-3p and the onset and prognosis of HCC has not been reported in previous studies; thus, the clinicopathological implications of miR-125b-2-3p in HCC require elaboration. To examine the expression of miR-125b-2-3p in HCC, both in-house RT-qPCR and public datasets were used to calculate the standard mean difference (SMD) and the summary receiver operating characteristic (sROC). MiR-125b-2-3p was markedly lower in HCC than in non-tumor tissue as assessed by the in-house RT-qPCR which was confirmed by the integrative analysis showing the SMD being -0.69 and the area under the curve (AUC) being 0.84 based on 1,233 cases of HCC and 630 cases of non-HCC controls. To gain a overview of the clinical value of miR-125b-2-3p in HCC, all possible datasets were integrated, and lower miR-125b-2-3p levels could lead to poorer differentiation and a more advanced clinical stage of HCC. The hazard ratio (HR) of miR-125b-2-3p was also calculated using a Cox proportional hazards model, and the miR-125b-2-3p level could act as an protective indication for the survival with the HR being 0.74 based on 586 cases of HCC. Furthermore, the effect of nitidine chloride (NC), a natural bioactive phytochemical alkaloid, on the regulation of miR-125b-2-3p and its potential targets was also investigated. The miR-125b-2-3p level was increased after NC treatment, while the expression of its potential target PRKCA was reduced. Above all, a low-expressed level of miR-125b-2-3p plays a tumor suppressive role in HCC.

USP9X deubiquitinates connexin43 to prevent high glucose-induced epithelial-to-mesenchymal transition in NRK-52E cells

Epithelial-to-mesenchymal transition (EMT) plays an important role in diabetic nephropathy (DN). Ubiquitin-specific protease 9X (USP9X/FAM) is closely linked to TGF-β and fibrosis signaling pathway. However, it remains unknown whether USP9X is involved in the process of EMT in DN. Our previous study has shown that connexin 43 (Cx43) activation attenuated the development of diabetic renal tubulointerstitial fibrosis (RIF). Here, we showed that USP9X is a novel negative regulator of EMT and the potential mechanism is related to the deubiquitination and degradation of Cx43. To explore the potential regulatory mechanism of USP9X, the expression and activity of USP9X were studied by CRISPR/Cas9-based synergistic activation mediator (SAM) system, short hairpin RNAs, and selective inhibitor. The following findings were observed: (1) Expression of USP9X was down-regulated in the kidney tissue of db/db diabetic mice; (2) overexpression of USP9X suppressed high glucose (HG)-induced expressions of EMT markers and extra cellular matrix (ECM) in NRK-52E cells; (3) depletion of USP9X further aggravated EMT process and ECM production in NRK-52E cells; (4) USP9X deubiquitinated Cx43 and suppressed its degradation to regulate EMT process; (5) USP9X deubiquitinated Cx43 by directly binding to the C-terminal Tyr²⁸⁶ of Cx43. The current study determined the protective role of USP9X in the process of EMT and the molecular mechanism clarified that the protective effects of USP9X on DN were associated with the deubiquitination of Cx43.

Polydatin attenuates renal fibrosis in diabetic mice through regulating the Cx32-Nox4 signaling pathway

We previously found that polydatin could attenuate renal oxidative stress in diabetic mice and improve renal fibrosis. Recent evidence shows that NADPH oxidase 4 (Nox4)-derived reactive oxygen species (ROS) contribute to inflammatory and fibrotic processes in diabetic kidneys. In this study we investigated whether polydatin attenuated renal fibrosis by regulating Nox4 in vitro and in vivo. In high glucose-treated rat glomerular mesangial cells, polydatin significantly decreased the protein levels of Nox4 by promoting its K48-linked polyubiquitination, thus inhibited the production of ROS, and eventually decreasing the expression of fibronectin (FN) and intercellular adhesion molecule-1 (ICAM-1), the main factors that exacerbate diabetic renal fibrosis. Overexpression of Nox4 abolished the inhibitory effects of polydatin on FN and ICAM-1 expression. In addition, the expression of Connexin32 (Cx32) was significantly decreased, which was restored by polydatin treatment. Cx32 interacted with Nox4 and reduced its protein levels. Knockdown of Cx32 abolished the inhibitory effects of polydatin on the expression of FN and ICAM-1. In the kidneys of streptozocin-induced diabetic mice, administration of polydatin (100 mg·kg-1·d-1, ig, 6 days a week for 12 weeks) increased Cx32 expression and reduced Nox4 expression, decreased renal oxidative stress levels and the expression of fibrotic factors, eventually attenuating renal injury and fibrosis. In conclusion, polydatin promotes K48-linked polyubiquitination and degradation of Nox4 by restoring Cx32 expression, thereby decreasing renal oxidative stress levels and ultimately ameliorating the pathological progress of diabetic renal fibrosis. Thus, polydatin reduces renal oxidative stress levels and attenuates diabetic renal fibrosis through regulating the Cx32-Nox4 signaling pathway.

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。

TC > 0.05 as a Pharmacokinetic Parameter of Paclitaxel for Therapeutic Efficacy and Toxicity in Cancer Patients

BACKGROUND

Paclitaxel (PTX) has remarkable anti-tumor activity, but it causes severe toxicities. There is an urgent need to seek an appropriate pharmacokinetic parameter of PTX to improve treatment efficacy and reduce adverse effects.

OBJECTIVE

To evaluate the association of pharmacokinetic parameter TC > 0.05 of paclitaxel (PTX) and its therapeutic efficacy and toxicity in patients with solid tumors.

METHODS

A total of 295 patients with ovarian cancer, esophageal cancer, breast cancer, and non-small cell lung cancer (NSCLC), who were admitted to the Tumor Hospital of Shantou University Medical College, China, were recruited for this study. Patients received 3 weeks of PTX chemotherapy. The plasma concentrations of PTX were examined using the MyPaclitaxel™ kit. The patients' PTX TC > 0.05 (the time during which PTX plasma concentration exceed 0.05µmol/L) were calculated based on pharmacokinetic analysis.

RESULTS

The results showed that: (1) the concentrations of PTX in these 295 patients ranged from 0.0358-0.127 µmol/L; (2) the PTX TC > 0.05 ranged from 14 to 38h with a median time of 27h; (3) among all treatment cycles, there was a statistically significant difference in the PTX TC > 0.05 between CR+PR and SD+PD; (4) with the increasing value of TC > 0.05, level of leukopenia and leukopenic fever increased; (5) high PTX TC > 0.05 led to the occurrence of neutropenia, neutropenic fever, severe anemia, and severe peripheral neurotoxicity. Taken together, our results indicated that the pharmacokinetic parameter PTX TC > 0.05 was an effective measure of treatment efficacy and toxicity in patients with solid tumors. Maintaining PTX TC > 0.05 at 26 to 30h could improve its efficacy and reduce the incidence of leukopenia, neutropenia, anemia, and peripheral neurotoxicity in these patients.

CONCLUSION

PTX TC > 0.05 is a key pharmacokinetic parameter of PTX which should be monitored to optimize individual treatment in patients with solid tumors.

Multiple variants in 5q31.1 are associated with systemic lupus erythematosus susceptibility and subphenotypes in the Han Chinese population

BACKGROUND

A previous study provided evidence for a genetic association between PPP2CA on 5q31.1 and systemic lupus erythematosus (SLE) across multi-ancestral cohorts, but failed to find significant evidence for an association in the Han Chinese population.

OBJECTIVES

To explore the association between this locus and SLE using data from our previously published genome-wide association study (GWAS).

METHODS

Single-nucleotide polymorphisms (SNPs) rs7726414 and rs244689 (near TCF7 and PPP2CA in 5q31.1) were selected as candidate independent associations from a large-scale study in a Han Chinese population consisting of 1047 cases and 1205 controls. Subsequently, 3509 cases and 8246 controls were genotyped in two further replication studies. We then investigated the SNPs' associations with SLE subphenotypes and gene expression in peripheral blood mononuclear cells.

RESULTS

Highly significant associations with SLE in the Han Chinese population were detected for SNPs rs7726414 and rs244689 by combining the genotype data from our previous GWAS and two independent replication cohorts. Further conditional analyses indicated that these two SNPs contribute to disease susceptibility independently. A significant association with SLE, age at diagnosis < 20 years, was found for rs7726414 (P = 0·001). The expression levels of TCF7 and PPP2CA messenger RNA in patients with SLE were significantly decreased compared with those in healthy controls.

CONCLUSIONS

This study found evidence for multiple associations with SLE in 5q31.1 at genome-wide levels of significance for the first time in a Han Chinese population, in a combined genotype dataset. These findings suggest that variants in the 5q31.1 locus not only provide novel insights into the genetic architecture of SLE, but also contribute to the complex subphenotypes of SLE.

Cerebral ganglion ultrastructure and differential proteins revealed using proteomics in the aplysiid (Notarcus leachii cirrosus Stimpson) under cadmium and lead stress

Cadmium (Cd) and lead (Pb) are both highly toxic metals in environments. However the toxicological mechanism is not clear. In this study, the aplysiid, Notarcus leachii cirrosus Stimpson (NLCS) was subjected to Cd (NLCS-Cd) or Pb (NLCS-Pb). The cerebral ganglion of NLCS was investigated with a transmission electron microscope. Next the differential proteins were separated and identified using proteomic approaches. Eighteen protein spots in NLCS-Cd and seventeen protein spots in NLCS-Pb were observed to be significantly changed. These protein spots were further excised in gels and identified. A hypothetical pathway was drawn to show the correlation between the partially identified proteins. The results indicated that damage to the cerebral ganglion was follows: cell apoptosis, lysosomes proliferation, cytoskeleton disruption, and oxidative stress. These phenomena and data indicated potential biomarkers for evaluating the contamination levels of Cd and Pb. This study provided positive insights into the mechanisms of Cd and Pb toxicity.

Novel A20-gene-eluting stent inhibits carotid artery restenosis in a porcine model

Background

Carotid artery stenosis is a major risk factor for ischemic stroke. Although carotid angioplasty and stenting using an embolic protection device has been introduced as a less invasive carotid revascularization approach, in-stent restenosis limits its long-term efficacy and safety. The objective of this study was to test the anti-restenosis effects of local stent-mediated delivery of the A20 gene in a porcine carotid artery model.

Materials and methods

The pCDNA3.1EHA20 was firmly attached onto stents that had been collagen coated and treated with N-succinimidyl-3-(2-pyridyldithiol)propionate solution and anti-DNA immunoglobulin fixation. Anti-restenosis effects of modified vs control (the bare-metal stent and pCDNA3.1 void vector) stents were assessed by Western blot and scanning electron microscopy, as well as by morphological and inflammatory reaction analyses.

Results

Stent-delivered A20 gene was locally expressed in porcine carotids in association with significantly greater extent of re-endothelialization at day 14 and of neointimal hyperplasia inhibition at 3 months than stenting without A20 gene expression.

Conclusion

The A20-gene-eluting stent inhibits neointimal hyperplasia while promoting re-endothelialization and therefore constitutes a novel potential alternative to prevent restenosis while minimizing complications.

The role of melanin pathways in extremotolerance and virulence of Fonsecaea revealed by de novo assembly transcriptomics using illumina paired-end sequencing

Melanisation has been considered to be an important virulence factor of Fonsecaea monophora. However, the biosynthetic mechanisms of melanisation remain unknown. We therefore used next generation sequencing technology to investigate the transcriptome and digital gene expression data, which are valuable resources to better understand the molecular and biological mechanisms regulating melanisation in F. monophora. We performed de novo transcriptome assembly and digital gene expression (DGE) profiling analyses of parent (CBS 122845) and albino (CBS 125194) strains using the Illumina RNA-seq system. A total of 17 352 annotated unigenes were found by BLAST search of NR, Swiss-Prot, Gene Ontology, Clusters of Orthologous Groups and Kyoto Encyclopedia of Genes and Genomes (KEGG) (E-value <1e‒5). A total of 2 283 unigenes were judged to be the differentially expressed between the two genotypes. We identified most of the genes coding for key enzymes involved in melanin biosynthesis pathways, including polyketide synthase (pks), multicopper oxidase (mco), laccase, tyrosinase and homogentisate 1,2-dioxygenase (hmgA). DEG analysis showed extensive down-regulation of key genes in the DHN pathway, while up-regulation was noted in the DOPA pathway of the albino mutant. The transcript levels of partial genes were confirmed by real time RT-PCR, while the crucial role of key enzymes was confirmed by either inhibitor or substrate tests in vitro. Meanwhile, numbers of genes involved in light sensing, cell wall synthesis, morphology and environmental stress were identified in the transcriptome of F. monophora. In addition, 3 353 SSRs (Simple Sequence Repeats) markers were identified from 21 600 consensus sequences. Blocking of the DNH pathway is the most likely reason of melanin deficiency in the albino strain, while the production of pheomelanin and pyomelanin were probably regulated by unknown transcription factors on upstream of both pathways. Most of genes involved in environmental tolerance to oxidants, irradiation and extreme temperatures were also assembled and annotated in transcriptomes of F. monophora. In addition, thousands of identified cSSR (combined SSR) markers will favour further genetic linkage studies. In conclusion, these data will contribute to understanding the regulation of melanin biosynthesis and help to improve the studies of pathogenicity of F. monophora.

Effects of goal-directed fluid therapy with different lactated Ringer's: hydroxyethyl starch ratios in hemorrhagic shock dogs

The effects of goal-directed fluid therapy, with lactated Ringer's (LR) and 6% hydroxyethyl starch (HES) solution, on hemorrhagic shock dogs are unknown. We aimed to determine the optimal LR: HES ratio for the resuscitation of hemorrhagic shock dogs. Hemorrhagic shock was induced in 40 ventilated dogs by drawing an estimated 60% blood volume. The animals were randomly divided into five groups (N = 8) according to the LR: HES ratio of the resuscitation fluid (3:1, 2:1, 1:1, 1:2, and 1:3), and were then resuscitated for 24 h to reach the stroke volume variation (SVV) and hemoglobin (Hb) goals by fluid infusion and autologous blood perfusion. The extravascular lung water index (EVLWI), pH, partial pressure of oxygen (PaO2), base excess (BE), sodium, chloride, Hb and creatinine clearance (Clearcrea) were checked after 24 h (R24). The EVLWI of the 3:1 group at R24 were higher than that of the 1:3 group and the baseline value (P < 0.05), whereas the PaO2 was lower (P < 0.05). In contrast to the 3:1 group at R24 and baseline, plasma chloride and sodium in the 1:3 and 1:2 groups increased; however, pH, BE, and Clearcrea decreased (P < 0.05). No significant differences were found in the 1:1 and 2:1 groups at R24 compared with baseline (P > 0.05). Resuscitation with LR and HES at 2:1 and 1:1 ratios are superior in maintaining the acid-base, electrolyte, and lung water balances as well as renal function in hemorrhagic shock dogs than at ratios of 3:l, 1:2, and1:3.

Formononetin sensitizes glioma cells to doxorubicin through preventing EMT via inhibition of histone deacetylase 5

Chemoresistance is a major obstacle to successful chemotherapy for glioma. Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus and possesses antitumorigenic properties. In the present study, we investigated the anti-proliferative effects of formononetin on human glioma cells, and further elucidated the molecular mechanism underlying the anti-tumor property. We found that formononetin enhanced doxorubicin cytotoxicity in glioma cells. Combined treatment with formononetin reversed the doxorubicin-induced epithelial-mesenchymal transition (EMT) in tumor cells. Moreover, we found that formononetin treatment significantly decreased the expression of HDAC5. Overexpression of HDAC5 diminished the suppressive effects of formononetin on glioma cell viability. Furthermore, knockdown of HDAC5 by siRNA inhibited the doxorubicin-induced EMT in glioma cells. Taken together, these results demonstrated that formononetin-combined therapy may enhance the therapeutic efficacy of doxorubicin in glioma cells by preventing EMT through inhibition of HDAC5.

Identification of differentially expressed proteins of brain tissue in response to methamidophos in flounder (Paralichthys olivaceus)

Methamidophos (MAP), an organophosphorus pesticide used around the world, has been associated with a wide spectrum of toxic effects on organisms in the environment. In this study, the flounder Paralichthys olivaceus was subjected to 10 mg/L MAP for 72 h and 144 h, and the morphological and proteomic changes in the brain were observed, analyzed and compared with those in the non-exposed control group. Under the light microscope and transmission electron microscope, MAP had evidently induced changes in or damage to the flounder tissues. Gas chromatography analysis demonstrated that the MAP residues were significantly accumulated in the flounder brain tissues. Proteomic changes in the brain tissue were revealed using two-dimensional gel electrophoresis and 27 protein spots were observed to be significantly changed by MAP exposure. The results indicated that the regulated proteins were involved in immune and stress responses, protein biosynthesis and modification, signal transduction, organismal development, and 50% of them are protease. qRT-PCR was used to further detect the corresponding change of transcription. These data may be beneficial to understand the molecular mechanism of MAP toxicity in flounder, be very useful for MAP-resistance screening in flounder culture. According to our results and analyzing, heat shock protein 90 (HSP90) and granzyme K (GzmK) had taken important part in immune response to MAP-stress and could be biomarkers for MAP-stress in flounder.

AGEs-RAGE system down-regulates Sirt1 through the ubiquitin-proteasome pathway to promote FN and TGF-β1 expression in male rat glomerular mesangial cells

We previously demonstrated that advanced glycation-end products (AGEs) promote the pathological progression of diabetic nephropathy by decreasing silent information regulator 2-related protein 1 (Sirt1) expression in glomerular mesangial cells (GMCs). Here, we investigated whether AGEs-receptor for AGEs (RAGE) system down-regulated Sirt1 expression through ubiquitin-proteasome pathway and whether Sirt1 ubiquitination affected fibronectin (FN) and TGF-β1, 2 fibrotic indicators in GMCs. Sirt1 was polyubiquitinated and subsequently degraded by proteasome. AGEs increased Sirt1 ubiquitination and proteasome-mediated degradation, shortened Sirt1 half-life, and promoted FN and TGF-β1 expression. Ubiquitin-specific protease 22 (USP22) reduced Sirt1 ubiquitination and degradation and decreased FN and TGF-β1 expression in GMCs under both basal and AGEs-treated conditions. USP22 depletion enhanced Sirt1 degradation and displayed combined effects with AGEs to further promote FN and TGF-β1 expression. RAGE functioned crucial mediating roles in these processes via its C-terminal cytosolic domain. Inhibiting Sirt1 by EX-527 substantially suppressed the down-regulation of FN and TGF-β1 resulting from USP22 overexpression under both normal and AGEs-treated conditions, eventually leading to their up-regulation in GMCs. These results indicated that the AGEs-RAGE system increased the ubiquitination and subsequent proteasome-mediated degradation of Sirt1 by reducing USP22 level, and AGEs-RAGE-USP22-Sirt1 formed a cascade pathway that regulated FN and TGF-β1 level, which participated in the pathological progression of diabetic nephropathy.

Toxicological responses of the hard clam Meretrix meretrix exposed to excess dissolved iron or challenged by Vibrio parahaemolyticus

The responses of genes encoding defense components such as ferritin, the lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITAF), the inhibitor of nuclear factor-κB (IκB), metallothionein, and glutathione peroxidase were assessed at the transcriptional level in order to investigate the toxicological and immune mechanism of the hard clam Meretrix meretrix (HCMM) following challenge with iron or a bacterium (Vibrio parahaemolyticus). Fe dissolved in natural seawater led to an increase of Fe content in both the hepatopancreas and gill tissue of HCMM between 4 and 15 days of exposure. The ferritin gene responded both transcriptionally as indicated by real-time quantitative PCR and translationally as shown by western blotting results to iron exposure and both transcriptional and translational ferritin expression in the hepatopancreas had a positive correlation with the concentration of dissolved iron in seawater. Both iron and V. parahaemolyticus exposure triggered immune responses with similar trends in clam tissues. There was a significant post-challenge mRNA expression of LITAF and IκB at 3h, ferritin at 24h, and metallothionein and glutathione peroxidase at 48h. This behavior might be linked to their specific functions in physiological processes. These results suggested that similar signaling pathways were triggered during both iron and V. parahaemolyticus challenges. Here, we indicated that the ferritin of Meretrix meretrix was an intermediate in the pathway of iron homeostasis and in its innate immune defense mechanism.

Differential expression profile of membrane proteins in Aplysia pleural–pedal ganglia under the stress of methyl parathion

This study was aimed to analyze the alteration of membrane protein profiles in Aplysia juliana Quoy & Gaimard (A. juliana) pleural–pedal ganglia under MP exposure. Both the results of GC–MS analysis and the activity assay of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) reveal that MP toxicological effects on Aplysia left and right pleural–pedal ganglia are different under 7 and 14 days of exposure. Therefore, Aplysia were subjected for exposure at two concentrations (1 and 2 mg/l) of MP for 7 and 14 days for membrane proteomic study. As a result, 19 and 14 protein spots were differentially expressed in A. juliana left pleural–pedal ganglia under 7 and 14 days treatment, and 20 and 14 protein spots found with differential expressions in their right ganglia under the same treatment, respectively. Several proteins with expression variations were detected from both the left and right pleural–pedal ganglia; however, most proteins have distinctive expressions, indicating different mechanisms might be involved in initiating MP toxicology in left and right ganglia. Among the total differential protein spots obtained, 29 proteins were classed as membrane proteins. These proteins are mainly involved in the metabolism process, cell redox homeostasis, signal transduction, immunology, intracellular transport and catalysis, indicating MP toxicity in mollusks seems to be complex and diverse. Some differentially expressed proteins were further confirmed by Western blotting and quantitative real-time PCR. These results might provide renovated insights to reveal the mechanism of MP-induced neurotoxicity, and the novel candidate biomarkers might have potential application for environmental evaluation of MP pollution level.

The evidence of HeLa cell apoptosis induced with tetraethylammonium using proteomics and various analytical methods

Tetraethylammonium (TEA) is a potassium channel (KCh) blocker applied in the functional and pharmacological studies of the KChs. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, a colorimetric assay to quantitatively measure living cells, demonstrated that TEA reduced the HeLa cell viability dose-dependently. Flow cytometry analysis indicated an increased apoptosis rate of the HeLa cell after exposing to TEA. The patch clamp technique revealed that the K(+) current of the HeLa cell was inhibited up to 80% when exposed to TEA. In addition, quantitative real-time PCR approach set up cross-talk among the cytotoxicity of TEA, 4-aminopyridine, and anti-cancer drug such as cisplatin. Using comparative proteomics combined with MALDI-TOF MS/MS, 33 significantly changed proteins were found from TEA treatment group; among these proteins, 12 were up-regulated, and 21 were down-regulated. Here we indicated that these proteins were closely connected with many biological functions such as oxidative stress response, signal transduction, metabolism, protein synthesis, and degradation. Both Western blotting and quantitative real-time PCR approaches further verified these differential proteins. Ingenuity Pathways Analysis software, a tool to analyze "omics" data and model biological system, was applied to analyze the interaction pathways of these proteins. The subcellular locations of the differential proteins are also predicted from Uniprot. All results above can help in our understanding of the mechanism of TEA-induced cytotoxicity and provide potential cancer biomarkers. Various experimental results in this study (like those for cisplatin) indicated that TEA is not only a KCh blocker but also a potential anti-cancer drug.

Differential protein profile in zebrafish (Danio rerio) brain under the joint exposure of methyl parathion and cadmium

As different chemicals, methyl parathion (MP) and cadmium (Cd) can induce neurotoxicity on the brain of aquatic ecosystems. This study aims to explore the differential expression proteins in the brain induced by their joint stress and their joint effects, which are poorly reported, and devotes finding novel biomarkers for monitoring their contamination in water and assessing their neurological effects. The bioaccumulation of MP and Cd in tissues after 96 h of exposure was first analyzed by GC and inductively coupled plasma-MS to provide insights into the interaction. Protein profile changes in the brains of the zebrafish (Danio rerio) exposed to MP and Cd were further investigated using the proteomic approach. The correlation of gene expression on the transcription level of mRNA and the translation level of protein was examined by real-time quantitative PCR and Western blotting analysis. It showed that Cd and MP have an interaction on their bioaccumulation, which suggests that their joint effect over 96 h might be antagonistic. Proteomics revealed that 22 protein spots changed their expression levels under stress, of which 16 proteins were identified using MS. These proteins were involved in oxidation/reduction, metabolism, energy production, receptor activity, and cytoskeleton assembly. Among them, five proteins with a remarkable abundance change are significantly suggested to play important roles in the joint effect. This work demonstrates that there exists an interaction between MP and Cd toxicities, which may aid in our understanding of the mechanism of neurotoxicity induced by joint stress. The results may also provide the possibility of the establishment of candidate biomarkers for monitoring MP and Cd contamination in water.

Transferrin-cisplatin specifically deliver cisplatin to HepG2 cells in vitro and enhance cisplatin cytotoxicity

Cisplatin is a major broad-spectrum chemotherapeutic agent, however, its dose-dependent side effects limit the administration of large doses. Presently, developing a drug targeted delivery system is suggested as one of the most promising approaches to minimize the side effects of cisplatin. Here, we found that each human serum transferrin (HTf) has the potential to bind with over 22 cisplatins, and the complex of apo-HTf-cisplatin can specifically deliver cisplatin to HepG2 cells (human hepatocellular liver carcinoma cell line) in vitro, and facilitate HepG2 cells to apoptosis. Moreover, proteomics methods revealed that the abundances of 23 proteins in HepG2 cells were remarkably altered in response to cisplatin/apo-HTf-cisplatin exposure, and Realtime-PCR revealed that a number of important genes related to chemotherapeutic cytotoxicity and chemotherapeutic resistance are differentially transcribed between the HepG2 cells of cisplatin exposed and HTf-cisplatin exposed. The pathway analysis of the differentially expressed proteins and gene transcriptions indicated that those regulated proteins and gene transcriptions are involved in apoptosis regulation, transcription, cell cycle control, protein biosynthesis, energy metabolism, signal transduction, protein binding and other functions. It indicated that the cisplatin toxicity in HepG2 cell is diverse, the transport process has an effect on the cisplatin cytotoxicity, and the mechanism of the apoptosis of HepG2 cells induced by apo-HTf-cisplatin is different from that of cisplatin.

Cloning analysis of ferritin and the cisplatin-subunit for cancer cell apoptosis in Aplysia juliana hepatopancreas

Ferritin, an iron storage protein, plays a key role in iron metabolism in vivo. Here, we have cloned an inducible ferritin cDNA with 519 bp within the open reading frame fragment from the hepatopancreas of Aplysia juliana (AJ). The subunit sequence of the ferritin was predicted to be a polypeptide of 172 amino acids with a molecular mass of 19.8291kDa and an isoelectric point of 5.01. The cDNA sequence of hepatopancreas ferritin in AJ was constructed into a pET-32a system for expressing its relative protein efficiently in E. coli strain BL21, under isopropyl-β-d-thiogalactoside induction. The recombinant ferritin, which was further purified on a Ni-NTA resin column and digested with enterokinase, was detected as a single subunit of approximately 20 kDa mass using both SDS-PAGE and mass spectrometry. The secondary structure and phosphorylation sites of the deduced amino acids were predicted using both ExPASy proteomic tools and the NetPhos 2.0 server, and the subunit space structure of the recombinant AJ ferritin (rAjFer) was built using a molecular operating environment software system. The result of in-gel digestion and identification using MALDI-TOF MS/MS showed that the recombinant protein was AjFer. ICP-MS results indicated that the rAjFer subunit could directly bind to cisplatin[cis-Diaminedichloroplatinum(CDDP)], giving approximately 17.6 CDDP/ferritin subunits and forming a novel CDDP-subunit. This suggests that a nanometer CDDP core-ferritin was constructed, which could be developed as a new anti-cancer drug. The flow cytometry results indicated that CDDP-rAjFer could induce Hela cell apoptosis. Results of the real-time PCR and Western blotting showed that the expression of AjFer mRNA was up-regulated in AJ under Cd(2+) stress. The recombinant AjFer protein should prove to be useful for further study of the structure and function of ferritin in Aplysia.

Proteomic analysis of dimethoate-responsive proteins in the oyster (Saccostrea cucullata) gonad

INTRODUCTION

The organophosphorus pesticide dimethoate (DM) has been widely used in agriculture, and its extensive use could still have left many environmental problems.

METHODS

In the present study, the oyster (Saccostrea cucullata) was subjected to acute DM toxicity (2 mg/L), and gas chromatographic analysis revealed and quantified residues of DM in the oyster gonad.

RESULTS

Two-dimensional gel electrophoresis showed 12 differentially expressed proteins in the DM-exposed oyster gonad in comparison to the control. Among these 12 protein spots, nine were down-regulated, and three were up-regulated. Both matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry and database searching were utilized to identify these differential proteins, and revealed five proteins previously described as being related to DM toxicity. In addition, the levels of mRNA expression corresponding to these differential proteins were further proved in part by real-time PCR. The functions of these proteins were summarized as: carrying out energy metabolism, DNA repair, DNA transcriptional regulation, and oxidative protection. The remaining seven protein spots were of particular interest in terms of their responses to DM, which have seldom been reported.

CONCLUSION

These data might point to a number of novel and significant biomarkers for evaluating the contamination levels of DM and provide useful insight into the mechanisms of DM toxicity in vivo.

Alteration of the kidney membrane proteome of Mizuhopecten yessoensis induced by low-level methyl parathion exposure

Methyl parathion (MP) is a widely used organophosphorus pesticide that causes severe health and environmental effects. We investigated the alteration of the proteomic profile in the membrane enriched fraction of the kidneys of the scallop Mizuhopecten yessoensis exposed to low-level MP. Gas chromatography analysis showed that MP residues were significantly accumulated in the kidneys and the digestive glands of the scallops. According to two-dimensional electrophoresis, 17 proteins were differentially modulated under MP exposure. The mRNA expressions of 12 differential proteins were analyzed using quantitative PCR, and 10 showed consistent alteration of mRNA level with that of protein expression level. Altered expressions of two proteins (mitochondrial processing peptidase and α-tubulin) were also examined using Western blotting, showing that the mitochondrial processing peptidase was down-regulated but α-tubulin remained unchanged in response to MP exposure. Subcellular locations of all the identified proteins that were predicted using bioinformatics tools indicate that few of them are permanently located in the membrane. The differentially expressed proteins are involved in several critical biological processes, and their relevance to human health has been illuminated. These data taken together have provided some novel insights into the chronic toxicity mechanism of MP and have suggested mitochondrial processing peptidase as a potential biomarker for human health and environmental monitoring.

Gonad differential proteins revealed with proteomics in oyster (Saccostrea cucullata) using alga as food contaminated with cadmium

As mercury and lead, cadmium (Cd) is one of the highly toxic metals in both the ocean and land environments, but its toxicological mechanism in organisms including human is still unclear because of the complex toxicological pathways in vivo. Here, the alga Chlorella vulgaris were cultivated at room temperature under the stress of cadmium (1 mg L(-1)) to obtain a toxic food, and then the contaminated food were directly supplied to oyster (Saccostrea cucullata) in seawater. After feeding with C. vulgaris contaminated with Cd (C. vulgaris-Cd), the differential proteins in the oyster gonad (OG) were effectively separated and identified with proteomic approaches. Eleven protein spots were observed to be significantly changed in the OG feeding with C. vulgaris-Cd, which seven spots of these differential proteins were down-regulated while four spots were up-regulated. These altered spots were further excised in gels and identified by a combined technique of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) and database searching. A portion of these differential proteins were further proofed by real-time PCR and Western blotting. The results indicate that the major functions of these differential proteins were described as follows: binding, protein translocation, catalysis, regulation of energy metabolism, reproductive function and skeleton structure. These differential proteins in part may effectively provide a few novel biomarkers for the evaluation of Cd pollution level via a food pathway for harming halobios, mammal and human health, and for understanding the complex mechanisms of Cd toxicity in vivo.

Alterations of protein profile in zebrafish liver cells exposed to methyl parathion: a membrane proteomics approach

Methyl parathion (MP) is an extensively used organophosphorus pesticide, which has been associated with a wide spectrum of toxic effects on environmental organisms. The aim of this study is to investigate the alterations of membrane protein profiles in zebrafish liver (ZFL) cell line exposed to MP for 24 h using proteomic approaches. Two-dimensional gel electrophoresis revealed a total of 13 protein spots, whose expression levels were significantly altered by MP. These differential proteins were subjected to matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry analysis, and nine proteins were identified to be membrane proteins, among which seven were up-regulated, while two were down-regulated. In addition, the mRNA levels corresponding to these differential membrane proteins were further analyzed by quantitative real-time PCR. And the differential expression of arginase-2 was specially validated via Western blotting. Regarding the physiological functions, these proteins are involved in molecular chaperon, cytoskeleton system, cell metabolism, signal transduction, transport and hormone receptor respectively, suggesting the complexity of MP-mediated toxicity to ZFL cell. These data could provide useful insights for better understanding the hepatotoxic mechanisms of MP and develop novel protein biomarkers for effectively monitoring MP contamination level in aquatic environment.

Different binding affinities of Pb2+ and Cu2+ to glycosylation variants of human serum transferrin interfere with the detection of carbohydrate-deficient transferrin

Carbohydrate-deficient transferrin (CDT) is a specific biomarker of alcohol abuse, and for diagnosis of chronic alcohol, abuse is often determined using isoelectric focusing (IEF) and chromatographic techniques. To allow this method to be used for the diagnosis of alcohol abuse, inferences of various physical and chemical factors with the detection of CDT have been investigated. However, few reports have focused thus far on whether different metal ions have different binding affinities to CDT and HTf variants or further interfere in the detection of CDT. Here, in order to figure out whether and how metal ions such as Pb(2+) and Cu(2+) bind to holo-human serum transferrin (holo-HTf) and further interfere in CDT detection, the binding characteristics and the binding parameters of holo-HTf with metal ions such as Pb(2+) and Cu(2+) were investigated using UV-visible spectroscopy, Fluorescence spectroscopy, and ICP-MS. Moreover, whether the metal ions such as Pb(2+) and Cu(2+) will reduce the diagnostic accuracy of CDT in clinic was investigated using IEF. The present study demonstrates that Pb(2+) and Cu(2+) have different binding affinities to holo-HTf variants and produce different changes in the relative amounts of each glycosylation isoforms of HTf. Accordingly, the glycosylation chains of HTf will affect the binding affinities of glycosylation isoforms with Pb(2+) and Cu(2+), causing further interferences in CDT detection.

Superoxide dismutase, catalase and acetylcholinesterase: biomarkers for the joint effects of cadmium, zinc and methyl parathion contamination in water

Heavy metals are known to reduce the activities of antioxidant enzymes (e.g. superoxide dismutase, catalase), while organophosphorous insecticides are known to inhibit the activity of the enzyme acetylcholinesterase. In this study, the activities of these three enzymes in zebrafish (Danio rerio) tissues were assessed to evaluate the consequences heavy metal and organophosphate contamination in aquatic systems. When the fish were contacted with water containing a single pollutant, superoxide dismutase activity was affected by the presence of Cd but not by methyl parathion or Zn. However, catalase and acetylcholinesterase activities were sensitive to all three pollutants. The combined treatment showed that the three enzymes could be chosen as biomarkers of joint pollution by both metals and organophosphate. Toxicity tests showed an antagonism interaction between methyl parathion and Cd or Zn, and the change of enzyme activities at 96 hours was in accordance with that.

Mass spectrometric characteristics and kinetics of iron release in visceral mass of Saccostrea cucullata

Ferritins with electrophoretic homogeneity were prepared from the visceral mass of Saccostrea cucullata in batch. The native PAGE approach showed similar electrophoretic mobility among pig pancreatic ferritin, liver ferritin of Dasyatis akajei, and visceral mass ferritin of Saccostrea cucullata. SDS-PAGE indicated that the Saccostrea cucullata visceral ferritin (SCVF) consisted of a single subunit type and had a molecular weight (MW) of approximately 20 kDa, suggesting that the protein shell in SCVF was composed of a single subunit. In addition, peptide mass fingerprinting and transmission electron microscopy were used to identify SCVF further, and to observe its molecular structure. We found that the molecular structure in SCVF was similar to that of most mammalian ferritins, which are composed of a protein shell and an iron core. The results of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry under the assistance of an acidic matrix, sinapic acid, also showed that SCVF was composed of a single subunit type and its subunit MW was calculated to be 19871.042 Da in the absence of heme. Kinetics analysis revealed that the complete process of iron release fitted the law of a first-order reaction, which is similar to that of most ferritins in mammals. Similar to bacterial ferritin, studies indicated that the shell consisted of a single subunit type and showed similar kinetics of iron release, suggesting that this subunit plays two important roles in iron release and storage, and that it shows different stability and intensity of interaction in carrying out its physiological functions in SCVF.

Single subunit type of ferritin from visceral mass of Saccostrea cucullata: cloning, expression and cisplatin-subunit analysis

Ferritin, the iron storage protein, plays a key role in iron metabolism. Here, we have cloned an inducible ferritin cDNA with 516 bp within the open reading frame fragment from the visceral mass of Saccostrea cucullata. The subunit sequence of the ferritin was predicted to be a polypeptide of 171 amino acids with a molecular weight (MW) of 19.9182 kDa and an isoelectric point of 5.24. The cDNA sequence of S. cucullata ferritin was constructed into a pET-32a expression system for expressing its relative protein efficiently in the Escherichia coli BL21 strain under isopropyl-β-D-thiogalactoside (IPTG) induction. The recombinant ferritin, which was further purified on a Ni-NTA resin column and digested with enterokinase, was detected as a single subunit of approximately MW 20 kDa using both SDS-PAGE and mass spectrometry. S. cucullata ferritin (ScFer) showed 98% identity with Crassostrea gigas ferritin at the amino acid level. The secondary structure and phosphorylation sites of deduced amino acids were predicted with ExPASy proteomics tools and the NetPhos 2.0 server, respectively, and the subunit space structure of recombinant S. cucullata ferritin (rScFer) was built using the molecular operating environmental software system. The results of both in-gel digestion and identification using MALDI-TOF MS/MS showed that the recombinant protein was ScFer. ICP-MS indicated that rScFer subunit can directly bind to cisplatin[cis-Diaminedichloroplatinum(CDDP)], giving approximately 22.9 CDDP/ferritin subunit for forming a novel complex of CDDP-subunit, which suggests that it constructs a nanometer CDDP core-ferritin for developing a new drug of anti-cancer. The results of both the real-time PCR and Western blotting showed that the expression of ScFer mRNA was up-regulated in the oyster under the stress of Cd(2+). In addition, the expression increment of ScFer mRNA under bacterial challenge indicated that ferritin participated in the immune response of S. cucullata. The recombinant ScFer should prove to be useful for further study of the structure and function of ferritin in S. cucullata.

Differential protein expression of kidney tissue in the scallop Patinopecten yessoensis under acute cadmium stress

Morphological and proteomic changes in the kidney of scallops exposed to acute cadmium chloride (CdCl₂) were observed, analyzed and compared with those in the non-exposed control group. Under microscopy the paraffin-embedded sections of the kidney revealed that the microstructure of the tissue had been severely deformed after Cd exposure. Two dimensional electrophoresis, MALDI-TOF mass spectrometry and database searches showed 13 differentially expressed protein spots, of which 11 were up-regulated, while two were down-regulated. Among these proteins, guanylate kinase (GK) and C₂H₂-type zinc finger protein are considered to be tightly connected with Cd toxicity. Further studies using quantitative PCR method validated that the GK mRNA was induced under Cd stress. Other proteins identified which had some relevance to Cd toxicity are also discussed. We suggested that differential proteins such as GK could play a potential role as novel biomarkers for monitoring the level of Cd contamination in seawater.

Cryptotanshinone suppressed inflammatory cytokines secretion in RAW264.7 macrophages through inhibition of the NF-κB and MAPK signaling pathways

Cryptotanshinone (CTS), a major constituent extracted from the medicinal herb Salvia miltiorrhiza Bunge, has well-documented antioxidative and anti-inflammatory effects. In the present study, the pharmacological effects and underlying molecular mechanisms of CTS on lipopolysaccharide (LPS)-induced inflammatory responses were investigated. By enzyme-linked immunosorbent assay, we observed that CTS reduced significantly the production of proinflammatory mediators (tumor necrosis factor-α and interleukin-6) induced by LPS in murine macrophage-like RAW264.7 cells. Mechanistically, CTS inhibited markedly the phosphorylation of mitogen-activated protein kinases (MAPKs), including ERK1/2, p38MAPK, and JNK, which are crucially involved in regulation of proinflammatory mediator secretion. Moreover, immunofluorescence and western blot analysis indicated that CTS abolished completely LPS-triggered nuclear factor-κB (NF-κB) activation. Taken together, these data implied that NF-κB and MAPKs might be the potential molecular targets for clarifying the protective effects of CTS on LPS-induced inflammatory cytokine production in macrophages.

Application of capillary isoelectric focusing and peptide mass fingerprinting in carbohydrate-deficient transferrin detection

Carbohydrate-deficient transferrin (CDT) is a specific biomarker of alcohol abuse and is widely used in clinical diagnosis to detect and follow up excessive alcohol consumption. However, false %CDT results still exist in CDT detection, because of interference from genetic variants and the lack of standardization in CDT analysis. Therefore, it is still very important to find a method with high sensitivity and high accuracy for CDT detection. Here, we compared the detection sensitivity and accuracy of pI values based methods [isoelectric focusing on polyacrylamide gel electrophoresis (IEF-PAGE) and capillary isoelectric focusing (CIEF)] with hydrophobic characteristic based methods [reversed-phase high-performance liquid chromatography (RP-HPLC)] on CDT detection. Moreover, we investigated the potential of peptide mass fingerprinting (PMF), a method based on the mass spectrometry to identify human transferrin (HTf) variants including CDT isoforms and genetic variants, based on their specific peptide masses. Results indicated that PMF can identify HTf variants including CDT isoforms and genetic variants based on their specific peptides, and CIEF showed higher sensitivity detection of HTf variants than RP-HPLC and IEF-PAGE did. Accordingly, we suggest that PMF is suitable for identifying CDT with high accuracy, and CIEF has potential for detection of CDT and genetic variants with high sensitivity; moreover, they are both worth further investigation in clinical diagnosis.

Relief of carotid stenosis improves impaired cognition in a rat model of chronic cerebral hypoperfusion

To investigate how cognitive impairment is affected by the relief of bilateral carotid stenosis, chronic cerebral hypoperfusion was established through stenosis of the bilateral carotid common artery in adult Sprague-Dawley rats. Subsequently, the model rats received the intragastric placebo, donepezil (5 mg per kg), or surgery to relieve carotid stenosis after bilateral carotid common artery stenosis. After carotid stenosis was relieved, the cerebral blood flow values significantly increased, and P300 latency and escape latency in the Morris water-maze were significantly shortened. The concentrations of acetylcholine and norepinephrine in the dorsal hippocampus increased after carotid stenosis was relieved. Furthermore, P300 latency and escape latency were shortened in the relief-treated group compared to the drug-treated group, and acetylcholine levels in the relief-treated group were higher than the drug-treated group. No significant difference was found for the norepinephrine levels in the dorsal hippocampus between the relief-treated and drug-treated groups. Cognitive impairment can be significantly reduced by bilateral carotid stenosis relief, and the effect of relieving stenosis on cognitive dysfunction is superior to the effect of administering an acetylcholinesterase inhibitor.

Proteomic analysis of methyl parathion-responsive proteins in zebrafish (Danio rerio) brain

Methyl parathion (MP), an organophosphorus pesticide used worldwide, has been associated with a wide spectrum of toxic effects on organisms in the environment. This study set out to analyze the alteration of protein profiles in MP-exposed zebrafish (Danio rerio) brain and find the proteins responsive to MP toxicity. Zebrafish were subjected to 1, 3 and 5mg/L MP and the proteomic changes in their brains were revealed using two-dimensional gel electrophoresis. Six protein spots were observed to be significantly changed by MP exposure. Among these, 4 spots were down-regulated, while 2 spots were up-regulated. These altered spots were excised from the gels and identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry and database searching. The results indicate that these proteins were involved in binding, catalysis, regulation of energy metabolism and cell structure. These data may provide novel biomarkers for the evaluation of MP contamination and useful insights for understanding the mechanisms of MP toxicity.