Deep learning assists detection of esophageal cancer and precursor lesions in a prospective, randomized controlled study.

Endoscopy is the primary modality for detecting asymptomatic esophageal squamous cell carcinoma (ESCC) and precancerous lesions. Improving detection rate remains challenging. We developed a system based on deep convolutional neural networks (CNNs) for detecting esophageal cancer and precancerous lesions [high-risk esophageal lesions (HrELs)] and validated its efficacy in improving HrEL detection rate in clinical practice (trial registration ChiCTR2100044126 at www.chictr.org.cn). Between April 2021 and March 2022, 3117 patients ≥50 years old were consecutively recruited from Taizhou Hospital, Zhejiang Province, and randomly assigned 1:1 to an experimental group (CNN-assisted endoscopy) or a control group (unassisted endoscopy) based on block randomization. The primary endpoint was the HrEL detection rate. In the intention-to-treat population, the HrEL detection rate [28 of 1556 (1.8%)] was significantly higher in the experimental group than in the control group [14 of 1561 (0.9%), P = 0.029], and the experimental group detection rate was twice that of the control group. Similar findings were observed between the experimental and control groups [28 of 1524 (1.9%) versus 13 of 1534 (0.9%), respectively; P = 0.021]. The system's sensitivity, specificity, and accuracy for detecting HrELs were 89.7, 98.5, and 98.2%, respectively. No adverse events occurred. The proposed system thus improved HrEL detection rate during endoscopy and was safe. Deep learning assistance may enhance early diagnosis and treatment of esophageal cancer and may become a useful tool for esophageal cancer screening.

Selenium deficiency aggravates bisphenol A-induced autophagy in chicken kidney through regulation of nitric oxide and adenosine monophosphate activated protein kinase/mammalian target of rapamycin signaling pathway.

Bisphenol A (BPA), a phenolic compound, is harmful to humans and animals as its residue in the water threatens multiple organs, especially the kidney. Low selenium (Se) diets are consumed in many regions of the world, and poor Se status has exacerbating effect on toxicity of several environmental chemicals. Here, we described the discovery path of Se deficiency aggravation on autophagy in BPA treated chicken kidney through regulating nitric oxide (NO) and adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathways. The actual dietary Se intake for chickens was 0.30 mg/kg in control group and 0.03 mg/kg in Low-Se group, and BPA exposure concentration for chickens was 0.05 g/kg. Chicken embryo kidney (CEK) cells were used in vitro and the BPA exposure concentration for CEK cells was 150 nM. We found that BPA significantly increased levels of NO and inducible nitric oxide synthase, activated AMPK/mTOR signaling pathways, thereby triggering p62/LC3/Beclin1 signaling, resulting in formations of autophagosome and autolysosome, and finally stimulating autophagy in the chicken kidney. Additionally, Se deficiency promoted the occurrence of autophagy in BPA-treated kidneys. Altogether, our findings showed that Se deficiency exacerbates BPA-induced renal autophagy in chickens via regulation of NO and AMPK/mTOR signaling pathways. These findings will improve our understandings of the mechanisms of nephrotoxicity of BPA and detoxification by Se in chickens. In addition, further work is required to determine if Se status of exposed populations needs to be considered in future epidemiological assessments.

Cost-effective low-coverage whole-genome sequencing assay for the risk stratification of gastric cancer.

BACKGROUND: Gastric cancer (GC), a multifactorial disease, is caused by pathogens, such as Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV), and genetic components. AIM: To investigate microbiomes and host genome instability by cost-effective, low-coverage whole-genome sequencing, as biomarkers for GC subtyping. METHODS: Samples from 40 GC patients were collected from Taizhou Hospital, Zhejiang Province, affiliated with Wenzhou Medical University. DNA from the samples was subjected to low-coverage whole-genome sequencing with a median genome coverage of 1.86 × (range: 1.03 × to 3.17 ×) by Illumina × 10, followed by copy number analyses using a customized bioinformatics workflow ultrasensitive chromosomal aneuploidy detector. RESULTS: Of the 40 GC samples, 20 (50%) were found to be enriched with microbiomes. EBV DNA was detected in 5 GC patients (12.5%). H. pylori DNA was found in 15 (37.5%) patients. The other 20 (50%) patients were found to have relatively higher genomic instability. Copy number amplifications of the oncogenes, ERBB2 and KRAS, were found in 9 (22.5%) and 7 (17.5%) of the GC samples, respectively. EBV enrichment was found to be associated with tumors in the gastric cardia and fundus. H. pylori enrichment was found to be associated with tumors in the pylorus and antrum. Tumors with elevated genomic instability showed no localization and could be observed in any location. Additionally, H. pylori-enriched GC was found to be associated with the Borrmann type II/III and gastritis history. EBV-enriched GC was not associated with gastritis. No statistically significant correlation was observed between genomic instability and gastritis. Furthermore, these three different molecular subtypes showed distinct survival outcomes (P = 0.019). EBV-positive tumors had the best prognosis, whereas patients with high genomic instability (CIN+) showed the worst survival. Patients with H. pylori infection showed intermediate prognosis compared with the other two subtypes. CONCLUSION: Thus, using low-coverage whole-genome sequencing, GC can be classified into three categories based on disease etiology; this classification may prove useful for GC diagnosis and precision medicine.

Feasibility of transgastric endoscopic gallbladder-preserving surgery for benign gallbladder diseases (with video).

BACKGROUND: With the increasing realization of the importance of gallbladder function, choledochoscopic gallbladder-preserving surgery has been advocated for benign gallbladder diseases. However, limited information is available regarding the use of endoscopic gallbladder-preserving surgery (EGPS) for patients with benign gallbladder diseases. The aim of this study was to evaluate the feasibility of EGPS for benign gallbladder diseases. METHODS: Between June 2020 and January 2021, 22 patients with gallbladder stones and/or gallbladder polyps were treated with EGPS. The main outcome measures included the rate of complications, residual gallbladder stones, and gallbladder stone recurrence. RESULTS: In this study, transgastric EGPS was successfully performed in 22 patients (13 female, 9 male) with benign gallbladder diseases, and included 8 cases of multiple gallstones, 4 cases of gallbladder polyps with gallstones, 6 cases of multiple gallbladder polyps, 2 cases of single gallstone, and 2 case of singe gallbladder polyp. The median time of transgastric EGPS was 118 min. During hospitalization, 4 patients suffered localized peritonitis (4/22, 18.2%), and these patients successfully recovered after conservative medical treatment. None of the patients experienced massive bleeding, delayed bleeding, diffuse peritonitis, or any other serious complications. During the median follow-up of 4 months, 1 patient suffered residual gallstone, while no gallstone recurrence or deaths related to transgastric EGPS occurred in any patients. CONCLUSIONS: Transgastric EGPS appears to be a feasible treatment method in selected patients with benign gallbladder diseases. However, as it is a new technique, further studies are needed to explore the long-term effectiveness of transgastric EGPS.

Transplantation of acellularized dermis matrix (ADM) plus fully covered metal stent to prevent stricture after circumferential endoscopic submucosal dissection of early esophageal cancer (with video).

BACKGROUD AND STUDY AIMS: Esophageal stricture is a serious adverse event occurring after circular endoscopic submucosal dissection (ESD) involving the whole esophagus. However, there is still a lack of effectively preventive methods. The main purpose of this study is to evaluate the efficacy of application of acellularized dermis matrix (ADM) for the prevention of post-ESD esophageal stricture. The main objective of this study was to evaluate the use of decellularized dermal matrix (ADM) in the prevention of post-esophageal ESD strictures. PATIENTS AND METHODS: A pilot, single-center, prospective study was conducted. The study enrolled seven patients who had high-risks with extended resection of developing post-ESD esophageal stricture. After undergoing ESD, we attached different size of ADM patches to the mucosal defects using titanium clips then fixed with a metal mesh stent. The stent covered with metal mesh was removed at the median time of 27 days after the endoscopic procedure. Follow-up and repeated outpatient endoscopic screening were performed at appropriate scheduled times. RESULTS: The average longitudinal diameter of the resected specimens was 58.3 mm (range 38-90 mm). There were three patients developing strictures postoperatively at a mean time of 87 days (range 42-140). The median number of postoperative endoscopic balloon dilatation (EBD) in patients with stenosis was 2 (range 2-9). There were no deaths during a median follow-up period of 6 moths (range 1-12). CONCLUSIONS: This study was performed to assess the efficacy and safe method of relieving the severity of esophageal stricture after ESD through transplantation of ADM.

The Dark Side of Pyroptosis of Diffuse Large B-Cell Lymphoma in B-Cell Non-Hodgkin Lymphoma: Mediating the Specific Inflammatory Microenvironment.

Background: Diffuse large B-cell lymphoma (DLBCL) is a common aggressive B-cell non-Hodgkin lymphoma (B-NHL). While combined chemotherapy has improved the outcomes of DLBCL, it remains a highly detrimental disease. Pyroptosis, an inflammatory programmed cell death, is considered to have both tumor-promoting and tumor-suppressing effects. The role of pyroptosis in DLBCL has been gradually appreciated, but its value needs further investigation. Methods: We analyzed mutations and copy number variation (CNV) alterations of pyroptosis-related genes (PRGs) from The Cancer Genome Atlas (TCGA) cohort and evaluated the differences in expression in normal B cells and DLBCL patients in two Gene Expression Omnibus (GEO) datasets (GSE12195 and GSE56315). Based on the expression of 52 PRGs, we divided 421 DLBCL patients from the GSE31312 dataset into distinct clusters using consensus clustering. The Kaplan-Meier method was used to prognosis among the three clusters, and GSVA was used to explore differences in the biological functions. ESTIMATE and single-sample gene-set enrichment analysis (ssGSEA) were used to analyze the tumor immune microenvironment (TME) in different clusters. A risk score signature was developed using a univariate survival analysis and multivariate regression analysis, and the reliability and validity of the signature were verified. By combining the signature with clinical factors, a nomogram was established to predict the prognosis of DLBCL patients. The alluvial diagram and correlation matrix were used to explore the relationship between pyroptosis risk score, clinical features and TME. Results: A large proportion of PRGs are dysregulated in DLBCL and associated with the prognosis. We found three distinct pyroptosis-related clusters (cluster A, B, and C) that differed significantly with regard to the prognosis, biological process, clinical characteristics, chemotherapeutic drug sensitivity, and TME. Furthermore, we developed a risk score signature that effectively differentiates high and low-risk patients. The nomogram combining this signature with several clinical indicators showed an excellent ability to predict the prognosis of DCBCL patients. Conclusions: This work demonstrates that pyroptosis plays an important role in the diversity and complexity of the TME in DLBCL. The risk signature of pyroptosis is a promising predictive tool. A correct and comprehensive assessment of the mode of action of pyroptosis in individuals will help guide more effective treatment.

Effectiveness and safety of over-the-scope clip in closing perforations after duodenal surgery.

BACKGROUND: Endoscopic resection of duodenal subepithelial lesions (SELs) is a difficult procedure with a high risk of perforation. At present, dealing with perforation after endoscopic resection of duodenal SELs is still considered a great challenge. AIM: To evaluate the effectiveness and safety of an over-the-scope clip (OTSC) in the treatment of perforation post-endoscopic resection of duodenal SELs. METHODS: From May 2015 to November 2019, 18 patients with perforation following endoscopic resection of duodenal SELs were treated with OTSCs. Data comprising the rate of complete resection, closure of intraprocedural perforation, delayed bleeding, delayed perforation, and postoperative infection were extracted. RESULTS: The rate of complete removal of duodenal SELs and successful closure of the perforation was 100%. The median perforation size was 1 cm in diameter. Seventeen patients had minor intraoperative bleeding, while the remaining 1 patient had considerable amount of bleeding during the procedure. Seven patients had postoperative abdominal infections, of which 1 patient developed an abscess in the right iliac fossa and another patient developed septic shock. All 18 patients recovered and were discharged. No delayed bleeding or perforation was reported. The mean time taken to resume normal diet after the procedure was 6.5 d. The mean postoperative hospital stay was 9.5 d. No residual or recurrent lesions were detected during the follow-up period (15-66 mo). CONCLUSION: Closing a perforation after endoscopic resection of duodenal SELs with OTSCs seems to be an effective and reasonably safe therapeutic method.

Use of Artificial Intelligence to Improve the Quality Control of Gastrointestinal Endoscopy.

With the rapid development of science and technology, artificial intelligence (AI) systems are becoming ubiquitous, and their utility in gastroenteroscopy is beginning to be recognized. Digestive endoscopy is a conventional and reliable method of examining and diagnosing digestive tract diseases. However, with the increase in the number and types of endoscopy, problems such as a lack of skilled endoscopists and difference in the professional skill of doctors with different degrees of experience have become increasingly apparent. Most studies thus far have focused on using computers to detect and diagnose lesions, but improving the quality of endoscopic examination process itself is the basis for improving the detection rate and correctly diagnosing diseases. In the present study, we mainly reviewed the role of AI in monitoring systems, mainly through the endoscopic examination time, reducing the blind spot rate, improving the success rate for detecting high-risk lesions, evaluating intestinal preparation, increasing the detection rate of polyps, automatically collecting maps and writing reports. AI can even perform quality control evaluations for endoscopists, improve the detection rate of endoscopic lesions and reduce the burden on endoscopists.

Progress of esophageal stricture prevention after endoscopic submucosal dissection by regenerative medicine and tissue engineering.

Endoscopic submucosal dissection (ESD) has been widely accepted as an effective treatment for early esophageal cancer. However, post-ESD esophageal stricture remains a thorny issue. We herein review many strategies for preventing post-ESD esophageal stricture, as well as discuss their strengths and weaknesses. These strategies include pharmacological prophylaxis, esophageal stent and tissue engineering and regenerative medicine treatment. In this review, we summarize these studies and discuss the underlying progress and future directions of tissue engineering and regenerative medicine treatment.

Identification and Validation of a Novel RNA-Binding Protein-Related Gene-Based Prognostic Model for Multiple Myeloma.

BACKGROUND: Multiple myeloma (MM) is a malignant hematopoietic disease that is usually incurable. RNA-binding proteins (RBPs) are involved in the development of many tumors, but their prognostic significance has not been systematically described in MM. Here, we developed a prognostic signature based on eight RBP-related genes to distinguish MM cohorts with different prognoses. METHOD: After screening the differentially expressed RBPs, univariate Cox regression was performed to evaluate the prognostic relevance of each gene using The Cancer Genome Atlas (TCGA)-Multiple Myeloma Research Foundation (MMRF) dataset. Lasso and stepwise Cox regressions were used to establish a risk prediction model through the training set, and they were validated in three Gene Expression Omnibus (GEO) datasets. We developed a signature based on eight RBP-related genes, which could classify MM patients into high- and low-score groups. The predictive ability was evaluated using bioinformatics methods. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and gene set enrichment analyses were performed to identify potentially significant biological processes (BPs) in MM. RESULT: The prognostic signature performed well in the TCGA-MMRF dataset. The signature includes eight hub genes: HNRNPC, RPLP2, SNRPB, EXOSC8, RARS2, MRPS31, ZC3H6, and DROSHA. Kaplan-Meier survival curves showed that the prognosis of the risk status showed significant differences. A nomogram was constructed with age; B2M, LDH, and ALB levels; and risk status as prognostic parameters. Receiver operating characteristic (ROC) curve, C-index, calibration analysis, and decision curve analysis (DCA) showed that the risk module and nomogram performed well in 1, 3, 5, and 7-year overall survival (OS). Functional analysis suggested that the spliceosome pathway may be a major pathway by which RBPs are involved in myeloma development. Moreover, our signature can improve on the R-International Staging System (ISS)/ISS scoring system (especially for stage II), which may have guiding significance for the future. CONCLUSION: We constructed and verified the 8-RBP signature, which can effectively predict the prognosis of myeloma patients, and suggested that RBPs are promising biomarkers for MM.

Prediction of Re-positivity for Coronavirus Nucleic Acid Among COVID-19 Patients in the Recovery Phase.

Background and Objectives: Although the pathogenesis and treatment of coronavirus disease 2019 (COVID-19) have been gradually revealed, the risk for re-emergence of coronavirus nucleic acids in recovered patients remains poorly understood. Hence, this study evaluated the risk predictors associated with re-positivity for virus nucleic acid. Methods: Between February 1 and March 20, 2020, we retrospectively reviewed the clinical epidemiological data of 129 COVID-19 patients who were treated at Zhongxiang People's Hospital of Hubei Province in China. Subsequently, a risk prediction model for the re-positivity of virus nucleic acid was developed, and a receiver operating characteristic (ROC) curve was drawn for further validation. Results: In this study, the rate of re-positivity for virus nucleic acid was 17.8% (23/129) where all re-positivity cases were asymptomatic. The median time interval from discharge to nucleic acid re-positivity to discharge after being cured again was 11.5 days (range: 7-23 days). Multivariate logistic regression analysis showed that leukocytopenia [odds ratio (OR) 7.316, 95% confidence interval (CI) 2.319-23.080, p = 0.001], prealbumin < 150 mg/L (OR 4.199, 95% CI 1.461-12.071, p = 0.008), and hyperpyrexia (body temperature >39°C, OR 4.643, 95% CI 1.426-15.117, p = 0.011) were independent risk factors associated with re-positivity. The area under the ROC curve was 0.815 (95% CI, 0.729-0.902). Conclusion: COVID-19 patients with leukocytopenia, low prealbumin level, and hyperpyrexia are more likely to test positive for virus nucleic acid after discharge. Timely and effective treatment and appropriate extension of hospital stays and quarantine periods may be feasible strategies for managing such patients.

Identification and Validation of a Novel DNA Damage and DNA Repair Related Genes Based Signature for Colon Cancer Prognosis.

Backgrounds: Colorectal cancer (CRC) with high incidence, has the third highest mortality of tumors. DNA damage and repair influence a variety of tumors. However, the role of these genes in colon cancer prognosis has been less systematically investigated. Here, we aim to establish a corresponding prognostic signature providing new therapeutic opportunities for CRC. Method: After related genes were collected from GSEA, univariate Cox regression was performed to evaluate each gene's prognostic relevance through the TCGA-COAD dataset. Stepwise COX regression was used to establish a risk prediction model through the training sets randomly separated from the TCGA cohort and validated in the remaining testing sets and two GEO datasets (GSE17538 and GSE38832). A 12-DNA-damage-and-repair-related gene-based signature able to classify COAD patients into high and low-risk groups was developed. The predictive ability of the risk model or nomogram were evaluated by different bioinformatics- methods. Gene functional enrichment analysis was performed to analyze the co-expressed genes of the risk-based genes. Result: A 12-gene based prognostic signature established within 160 significant survival-related genes from DNA damage and repair related gene sets performed well with an AUC of ROC 0.80 for 5 years in the TCGA-CODA dataset. The signature includes CCNB3, ISY1, CDC25C, SMC1B, MC1R, LSP1P4, RIN2, TPM1, ELL3, POLG, CD36, and NEK4. Kaplan-Meier survival curves showed that the prognosis of the risk status owns more significant differences than T, M, N, and stage prognostic parameters. A nomogram was constructed by LASSO regression analysis with T, M, N, age, and risk as prognostic parameters. ROC curve, C-index, Calibration analysis, and Decision Curve Analysis showed the risk module and nomogram performed best in years 1, 3, and 5. KEGG, GO, and GSEA enrichment analyses suggest the risk involved in a variety of important biological processes and well-known cancer-related pathways. These differences may be the key factors affecting the final prognosis. Conclusion: The established gene signature for CRC prognosis provides a new molecular tool for clinical evaluation of prognosis, individualized diagnosis, and treatment. Therapies based on targeted DNA damage and repair mechanisms may formulate more sensitive and potential chemotherapy regimens, thereby expanding treatment options and potentially improving the clinical outcome of CRC patients.

H2S exposure-induced oxidative stress promotes LPS-mediated hepatocyte autophagy through the PI3K/AKT/TOR pathway.

Hydrogen sulfide (H2S), a common air pollutant and toxic gas, is detrimental to organisms and the environment. Exposure to highly concentrated H2S can induce oxidative stress and autophagy. However, the mechanism underlying the liver damage caused by H2S has not been identified. Lipopolysaccharide (LPS), the key component of endotoxin, can induce oxidative stress and autophagy. For this experiment, we used one-day-old chickens as model organisms to evaluate the effects of H2S combined with LPS on oxidative stress and autophagy. The four groups (control group, LPS group, H2S group and H2S-LPS group) were observed by electron microscopy, detected by oxidative stress kit, analyzed by quantitative real-time quantitative PCR, and analyzed by Western blot. We found that the activities of antioxidant enzymes (superoxide dismutase, antioxidant glutathione, catalase, and glutathione peroxidase) decreased in the H2S group compared to those in the control group; however, malondialdehyde levels in the H2S group increased. Molecular-level studies showed that the expression of genes associated with the PI3K/ AKT/ TOR pathways in the H2S group decreased, whereas the expression of other autophagy-related genes (Beclin1, ATG5 and the ratio of LC3-II/ LC3-I) increased compared to that in the control group. These findings suggest that H2S caused oxidative stress and induced autophagy through the PI3K/ AKT/ TOR pathway in chicken liver cells. Additionally, exposure to H2S aggravated LPS-induced oxidative stress and autophagy injury. Capsule: Aerial exposure to H2S can cause oxidative stress in chicken livers and induce autophagy through the PI3K/AKT/TOR pathway, and can aggravate LPS-induced oxidative stress and autophagy.

Nitrate Reductase-Mediated Nitric Oxide Regulates the Leaf Shape in Arabidopsis by Mediating the Homeostasis of Reactive Oxygen Species.

As a gaseous biological signaling molecule, nitric oxide (NO) regulates many physiological processes in plants. Over the last decades, this low molecular weight compound has been identified as a key signaling molecule to regulate plant stress responses, and also plays an important role in plant development. However, elucidation of the molecular mechanisms for NO in leaf development has so far been limited due to a lack of mutant resources. Here, we employed the NO-deficient mutant nia1nia2 to examine the role of NO in leaf development. We have found that nia1nia2 mutant plants displayed very different leaf phenotypes as compared to wild type Col-0. Further studies have shown that reactive oxygen species (ROS) levels are higher in nia1nia2 mutant plants. Interestingly, ROS-related enzymes ascorbate peroxidase (APX), catalases (CAT), and peroxidases (POD) have shown decreases in their activities. Our transcriptome data have revealed that the ROS synthesis gene RBOHD was enhanced in nia1nia2 mutants and the photosynthesis-related pathway was impaired, which suggests that NO is required for chloroplast development and leaf development. Together, these results imply that NO plays a significant role in plant leaf development by regulating ROS homeostasis.

Gga-let-7f-3p promotes apoptosis in selenium deficiency-induced skeletal muscle by targeting selenoprotein K.

Selenoprotein K (SELENOK) is primarily observed in the endoplasmic reticulum, and serves to maintain the normal physiological functions of skeletal muscle. Skeletal muscle development and regeneration are associated with significant changes in the expression of specific microRNAs (miRNAs). Downregulated SELENOK expression is observed in chicken muscles deficient of Se. However, the mechanisms of miRNA regulation of SELENOK expression remain elusive. Here, deep sequencing was used to detect the miRNA profiles of muscle in Se deficient (-Se group) and normal (C group) chickens. A dual-luciferase reporter assay was adopted to verify the relationship between SELENOK and gga-let-7f-3p. In addition, gga-let-7f-3p was either overexpressed or knocked-down in chicken myoblasts. Furthermore, the cells were treated with N-acetyl-l-cysteine (NAC) or hydrogen peroxide (H2O2) in order to probe the factors involved in oxidative stress, endoplasmic reticulum stress (ERS) and apoptosis, respectively. Relative to the C group, there were 132 differentially expressed miRNAs (including 57 upregulated and 75 downregulated) in the muscles of the -Se group. The dual-luciferase reporter assay showed that SELENOK was a primary target of gga-let-7f-3p. It was also observed that the overexpression or knock-down of gga-let-7f-3p significantly influenced the SELENOK expression. Moreover, NAC blocked mimics of ga-let-7f-3p, thus inducing oxidative stress, ERS and apoptosis. Simultaneously, gga-let-7f-3p inhibitors blocked the stimulant effects caused by H2O2 in chicken myoblasts. Furthermore, Se deficiency downregulated the SELENOK protein expression and induced oxidative stress, ERS and apoptosis in chicken muscles. In conclusion, the gga-let-7f-3p-SELENOK pathway played a pivotal role in Se deficiency mediated muscle injuries through the induction of oxidative stress and ERS, ultimately promoting apoptosis.

Selenophosphate synthetase 1 (SPS1) is required for the development and selenium homeostasis of central nervous system in chicken (Gallus gallus).

Selenophosphate synthetase (SPS) is essential for selenoprotein biosynthesis. In two SPS paralogues, SPS1 was only cloned from a cDNA library prepared from avian organ. However, the biological function of SPS1 in chicken central nervous system (CNS) remains largely unclear. To investigate the role of avian SPS1 in the development and selenium (Se) homeostasis of CNS, fertile eggs, chicken embryos, embryo neurons and chicks were employed in this study. The response of SPS1 transcription to the development and Se levels of CNS tissues was analyzed using qRT-PCR. SPS1 gene exists extensively in the development of chicken CNS. The wide expression of avian SPS1 can be controlled by the Se content levels, which suggests that SPS1 is important in the regulation of Se homeostasis. The fundamental mechanism of these effects is that Se alters the half-life and stability of SPS1 mRNA. Therefore, SPS1 exerts an irreplaceable biological function in chicken CNS and Se homeostasis is closely related to the expression of SPS1. These results suggested that SPS1 was required for the development and Se homeostasis of CNS in chicken.

A Novel Organic Selenium Compound Exerts Unique Regulation of Selenium Speciation, Selenogenome, and Selenoproteins in Broiler Chicks.

Background: A new organic selenium compound, 2-hydroxy-4-methylselenobutanoic acid (SeO), displayed a greater bioavailability than sodium selenite (SeNa) or seleno-yeast (SeY) in several species.Objective: This study sought to determine the regulation of the speciation of selenium, expression of selenogenome and selenocysteine biosynthesis and degradation-related genes, and production of selenoproteins by the 3 forms of selenium in the tissues of broiler chicks.Methods: Day-old male chicks (n = 6 cages/diet, 6 chicks/cage) were fed a selenium-deficient, corn and soy-based diet [base diet (BD), 0.05 mg Se/kg] or the BD + SeNa, SeY, or SeO at 0.2 mg Se/kg for 6 wk. Plasma, livers, and pectoral and thigh muscles were collected at weeks 3 and 6 to assay for total selenium, selenomethionine, selenocysteine, redox status, and selected genes, proteins, and enzymes.Results: Although both SeY and SeO produced greater concentrations (P < 0.05) of total selenium (20-172%) and of selenomethionine (≤15-fold) in the liver, pectoral muscle, and thigh than those of SeNa, SeO further raised (P < 0.05) these concentrations by 13-37% and 43-87%, respectively, compared with SeY. Compared with the BD, only SeO enhanced (P < 0.05) the mRNA of selenoprotein (Seleno) s and methionine sulfoxide reductase B1 (Msrb1) in the liver and thigh (62-98%) and thioredoxin reductase (TXRND) activity in the pectoral and thigh muscles (20-37%) at week 3. Furthermore, SeO increased (P < 0.05) the expression of glutathione peroxidase (Gpx) 3, GPX4, SELENOP, and SELENOU relative to the SeNa group by 26-207%, and the expression of Selenop, O-phosphoseryl-transfer RNA (tRNA):selenocysteinyl-tRNA synthase, GPX4, and SELENOP relative to the SeY group by 23-55% in various tissues.Conclusions: Compared with SeNa or SeY, SeO demonstrated a unique ability to enrich selenomethionine and total selenium depositions, to induce the early expression of Selenos and Mrsb1 mRNA and TXRND activity, and to enhance the protein production of GPX4, SELENOP, and SELENOU in the tissues of chicks.

Effects of Atrazine and Chlorpyrifos on Autophagy-Related Genes in the Brain of Common Carp: Health-Risk Assessments.

This study assessed the impacts of atrazine (ATR), chlorpyrifos (CPF), and a combined ATR/CPF exposure on the brain of common carp (Cyprinus carpio L.). The carp were sampled after a 40-days exposure to CPF and ATR, individually or in combination, followed by a 40-days recovery period to measure autophagy and antioxidant activity. The results indicate that the anti-superoxide anion and anti-hydroxy radical activities decreased upon exposure to ATR, CPF, and the ATR/CPF combination but increased after a subsequent 40-days recovery period. Quantitative real-time PCR and Western blot analyses revealed that the mRNA and protein levels of LC3B and dynein in common carp decreased significantly after exposure to ATR and CPF alone or in combination. Moreover, the mRNA and protein levels of beclin1 gene decreased significantly only in the 116 and 11.3 µg/L treatment groups. However, the mRNA and protein levels of all tested genes increased significantly after a 40-days recovery. Transmission electron microscope demonstrated the occurrence of autolysosomes in the recovery groups but not in the exposure groups. These results suggest that exposure to ATR, CPF, or their combination promotes oxidative stress and autophagic responses in the brain of common carp.

The role of selenoprotein W in inflammatory injury in chicken immune tissues and cultured splenic lymphocyte.

Selenoprotein W (SelW) is mainly understood in terms of its antioxidant effects in the cellular defense system. Inflammation is an important indicator of animal tissue injury, and the inflammatory cells may trigger a sophisticated and well-orchestrated inflammatory cascade, resulting in exaggerated oxidative stress. To investigate the role of SelW in inflammatory injury in chicken immune tissues and cultured splenic lymphocyte, in this report, the effects of selenium (Se) on mRNA expressions of SelW and inflammatory factors (iNOS, COX-2, NF-κB, PTGEs, and TNF-α) in the chicken immune organs (spleen, thymus and bursa of Fabricius) and cultured splenic lymphocyte treated with sodium selenite and H2O2, or knocked down SelW with small interfering RNAs (siRNAs) were examined. The results showed that Se-deficient diets effectively decreased the mRNA expression of SelW (P < 0.05), and induced a significantly up-regulation of COX-2, iNOS, NF-κB, PTGEs and TNF-α mRNA levels (P < 0.05). The histopathological analysis showed that immune tissues were obviously injured in the low-Se groups. In vitro, H2O2 induced a significantly up-regulation of the mRNA levels of inflammation-related genes (iNOS, COX-2, NF-κB, PTGEs, and TNF-α) in cultured splenic lymphocyte (P < 0.05). When lymphocytes were pretreated with Se before treated with H2O2, the inflammation-related genes were significantly decreased (P < 0.05). Silencing of SelW significantly up-regulated the inflammation-related genes (iNOS, COX-2, NF-κB, PTGEs, and TNF-α) in cultured splenic lymphocyte (P < 0.05). The results suggested that the expression levels of inflammatory factors (iNOS, COX-2, NF-κB, PTGEs, and TNF-α) and SelW can be influenced by Se in birds. SelW commonly played an important role in the protection of immune organs of birds from inflammatory injury by the regulations of inflammation-related genes.

The role of nitric oxide and oxidative stress in intestinal damage induced by selenium deficiency in chickens.

Nitric oxide (NO) is an essential messenger molecule and is associated with inflammation and oxidative stress. Although NO has important biological functions in mammals, its role in the mechanism that occurs after intestinal injuries in chickens remains unknown. The objective of the present study was to investigate the real role of NO and oxidative stress in the intestinal injuries of chickens induced by selenium (Se) deficiency. A total 150 chickens were randomly divided into the following two groups: a low-Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a commercial diet containing 0.2 mg/kg Se). The activities and mRNA levels of glutathione peroxidase (GSH-Px), the production of glutathione (GSH) and NO, and the protein and mRNA levels of inducible nitric oxide synthase (iNOS) were examined in the intestinal tissues (duodenum, jejunum, and rectum) at 15, 25, 35, 45, and 55 days. Methane dicarboxylic aldehyde (MDA) levels were also detected by assay kits. Then, the morphologies of the tissues were observed under the microscope after hematoxylin and eosin staining (H&E staining). The results showed that Se deficiency induced higher inflammatory damage and MDA levels (P < 0.05), which were accompanied by higher levels of iNOS and NO but lower levels of GSH and GSH-Px (P < 0.05). Our results indicated that Se deficiency induced oxidative damage in the intestinal tracts of chickens and that low levels of GSH-Px and high contents of NO may exert a major role in the injury of the intestinal tract induced by Se deficiency.