Molecular regulation of DNA damage and repair in female infertility: a systematic review.

DNA damage is a key factor affecting gametogenesis and embryo development. The integrity and stability of DNA are fundamental to a woman's successful conception, embryonic development, pregnancy and the production of healthy offspring. Aging, reactive oxygen species, radiation therapy, and chemotherapy often induce oocyte DNA damage, diminished ovarian reserve, and infertility in women. With the increase of infertility population, there is an increasing need to study the relationship between infertility related diseases and DNA damage and repair. Researchers have tried various methods to reduce DNA damage in oocytes and enhance their DNA repair capabilities in an attempt to protect oocytes. In this review, we summarize recent advances in the DNA damage response mechanisms in infertility diseases such as PCOS, endometriosis, diminished ovarian reserve and hydrosalpinx, which has important implications for fertility preservation.

E2Fs co-participate in cadmium stress response through activation of MSHs during the cell cycle.

Cadmium is one of the most common heavy metal contaminants found in agricultural fields. MutSα, MutSß, and MutSγ are three different MutS-associated protein heterodimer complexes consisting of MSH2/MSH6, MSH2/MSH3, and MSH2/MSH7, respectively. These complexes have different mismatch recognition properties and abilities to support MMR. However, changes in mismatch repair genes (OsMSH2, OsMSH3, OsMSH6, and OsMSH7) of the MutS system in rice, one of the most important food crops, under cadmium stress and their association with E2Fs, the key transcription factors affecting cell cycles, are poorly evaluated. In this study, we systematically categorized six rice E2Fs and confirmed that OsMSHs were the downstream target genes of E2F using dual-luciferase reporter assays. In addition, we constructed four msh mutant rice varieties (msh2, msh3, msh6, and msh7) using the CRISPR-Cas9 technology, exposed these mutant rice seedlings to different concentrations of cadmium (0, 2, and 4 mg/L) and observed changes in their phenotype and transcriptomic profiles using RNA-Seq and qRT-PCR. We found that the difference in plant height before and after cadmium stress was more significant in mutant rice seedlings than in wild-type rice seedlings. Transcriptomic profiling and qRT-PCR quantification showed that cadmium stress specifically mobilized cell cycle-related genes ATR, CDKB2;1, MAD2, CycD5;2, CDKA;1, and OsRBR1. Furthermore, we expressed OsE2Fs in yeasts and found that heterologous E2F expression in yeast strains regulated cadmium tolerance by regulating MSHs expression. Further exploration of the underlying mechanisms revealed that cadmium stress may activate the CDKA/CYCD complex, which phosphorylates RBR proteins to release E2F, to regulate downstream MSHs expression and subsequent DNA damage repairment, thereby enhancing the response to cadmium stress.

Dietary Supplemental Chromium Yeast Improved the Antioxidant Capacity, Immunity and Liver Health in Broilers under High Stocking Density.

This study was conducted to investigate the effects of different levels of yeast chromium on growth performance, organ index, antioxidant capacity, immune performance and liver health of broilers under high stocking density. A total of 684 1-day-old Arbor Acres broilers were selected and fed a common diet from 1 to 22 days of age. At the end of 22 days, broilers with similar weight were randomly divided into six treatments, with six replications in each treatment. The broilers in control groups were fed with a control diet and raised at low stocking density of broilers (14 broilers/m2, LSD) and high stocking density (20 broilers/m2, HSD). The broilers in treatment groups were fed with diets supplemented with 200, 400, 800 and 1600 µg Cr/kg chromium yeast (Cr-yeast) under HSD, respectively. The experimental period was 23~42 days. Compared with the LSD group, the HSD group significantly decreased the liver index (ratio of liver weight to live weight of broilers) of broilers (p < 0.05), the HSD group significantly increased the content of corticosterone (CORT) and the activities of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) and decreased the prealbumin (PA) level in the serum (p < 0.05). HSD decreased the total antioxidant capacity (T-AOC) contents in the serum, liver and breast, serum glutathione peroxidase (GSH-Px) activities, breast total superoxide dismutase (T-SOD) activities and liver catalase (CAT) activities of broilers (p < 0.05). The HSD group significantly increased the total histopathological score (p < 0.05). Compared with the HSD group, adding 200, 400, and 1600 Cr-yeast significantly increased the liver index of broilers (p < 0.05), all HSD + Cr-yeast groups decreased the ALT activities (p < 0.05), and the HSD + 800 group significantly decreased the CORT contents and the ALP activities of the serum (p < 0.05); the HSD + 400, 800 and 1600 groups increased the PA contents of the serum (p < 0.05); HSD + 800 group significantly reduced the tumor necrosis factor-α (TNF-α) and Interleukin-1ß (IL-1ß) contents of the serum (p < 0.05); moreover, the HSD + 400 group increased the GSH-Px activities of the serum (p < 0.05), the T-AOC and the T-SOD activities of the breast (p < 0.05) and the T-AOC and CAT activities of the liver (p < 0.05). Adding 800 Cr-yeast significantly decreased the total histopathological score (degree of hepatocyte edema and inflammatory cell infiltration) under HSD (p < 0.05). In summary, Cr-yeast can improve the antioxidant capacity and immune traits, and liver health of broilers under HSD. Based on the results of the linear regression analysis, the optimal supplementation of Cr-yeast in antioxidant capacity, immunity ability and liver health were at the range of 425.00−665.00, 319.30−961.00, and 800.00−1531.60 µg Cr/kg, respectively.

Dissection of transcriptome dysregulation and immune characterization in women with germline BRCA1 mutation at single-cell resolution.

BACKGROUND: High-grade serous carcinoma (HGSC) is the most frequent and lethal type of ovarian cancer. It has been proposed that tubal secretory cells are the origin of ovarian HGSC in women with familial BRCA1/2 mutations. However, the molecular changes underlying malignant transformation remain unknown. METHOD: We performed single-cell RNA and T cell receptor sequencing of tubal fimbriated ends from 3 BRCA1 germline mutation carriers (BRCA1 carriers) and 3 normal controls with no high-risk history (non-BRCA1 carriers). RESULTS: Exploring the transcriptomes of 19,008 cells, predominantly from BRCA1+ samples, we identified 5 major cell populations in the fallopian tubal mucosae. The secretory cells of BRCA1+ samples had differentially expressed genes involved in tumor growth and regulation, chemokine signaling, and antigen presentation compared to the wild-type BRCA1 controls. There are several novel findings in this study. First, a subset of the fallopian tubal secretory cells from one BRCA1 carrier exhibited an epithelial-to-mesenchymal transition (EMT) phenotype, which was also present in the mucosal fibroblasts. Second, we identified a previously unreported phenotypic split of the EMT secretory cells with distinct evolutionary endpoints. Third, we observed increased clonal expansion among the CD8+ T cell population from BRCA1+ carriers. Among those clonally expanded CD8+ T cells, PD-1 was significantly increased in tubal mucosae of BRCA1+ patients compared with that of normal controls, indicating that T cell exhaustion may occur before the development of any premalignant or malignant lesions. CONCLUSION: These results indicate that EMT and immune evasion in normal-looking tubal mucosae may represent early events leading to the development of HGSC in women with BRCA1 germline mutation. Our findings provide a probable molecular mechanism explaining why some, but not all, women with BRCA1 germline mutation present with early development and rapid dissemination of HGSC.

Selenium regulates the mitogen-activated protein kinase pathway to protect broilers from hexavalent chromium-induced kidney dysfunction and apoptosis.

Hexavalent chromium [Cr (VI)] is a common environmental pollutant. Although selenium (Se) can antagonize the toxicity of Cr (VI), the specific underlying mechanism has not been identified. To investigate this mechanism, we used potassium dichromate (K2Cr2O7) and selenium-rich yeast (SeY) to construct single Cr (VI)- and combined Se/Cr (VI)-exposed broiler models during a 42-day period. Broilers were randomly assigned to the control (C), SeY (Se), SeY + Cr (VI) (Se/Cr), and Cr (VI) (Cr) groups. The antagonistic mechanisms of Se and Cr (VI) were evaluated using histopathological evaluation, serum and tissue biochemical tests, real-time fluorescence quantitative polymerase chain reaction, and western blotting. The results suggested that Se alleviated the morphological and structural damage to renal tubules and glomeruli, while reducing the organ index, creatinine levels, and blood urea nitrogen levels in the kidneys of Cr (VI)-exposed broilers. Furthermore, Cr (VI) reduced the levels of superoxide dismutase and glutathione, and increased the levels of malondialdehyde, in broiler kidney tissues. However, Se alleviated Cr (VI)-induced oxidative stress by increasing the levels of superoxide dismutase and glutathione, and decreasing the levels of malondialdehyde, within a certain range. Compared to the C group, the levels of p38, JNK, p-p38, p-JNK, p-p38/p38, and p-JNK/JNK significantly increased, whereas those of ERK, p-ERK, and p-ERK/ERK decreased, in the Cr group. Compared to the Cr group, the levels of p38, JNK, p-p38, p-JNK, p-p38/p38, and p-JNK/JNK significantly decreased, whereas those of ERK, p-ERK, and p-ERK/ERK increased, in the Se/Cr group. Furthermore, the levels of p53, c-Myc, Bax, Cyt-c, caspase-9, and caspase-3 significantly increased, and those of Bcl-2 and Bcl-2/Bax significantly decreased, following Cr (VI) exposure, while Se restored the expression of these genes. In conclusion, our findings suggest that SeY can protect against Cr (VI)-induced dysfunction and apoptosis by regulating the mitogen-activated protein kinase pathway activated by oxidative stress in broiler kidney tissues.

Clinical efficacy evaluation of Erlotinib Combined with Concurrent Chemoradiotherapy in the treatment of locally advanced Pancreatic Cancer.

OBJECTIVE: To evaluate the clinical effects of erlotinib combined with concurrent chemoradiotherapy in the treatment of locally advanced pancreatic cancer. METHODS: Eighty patients with locally advanced pancreatic cancer who attended Shijiazhuang People's Hospital or Anhui Cancer Hospital between January 2018 and January 2020 were randomly divided into two groups, with 40 cases in each group. Patients in the control group were treated with concurrent chemoradiotherapy, while those in the experimental group were treated with erlotinib tablets based on the treatment regimen of the control group. Anti-tumor efficacy evaluation was conducted for all patients in both groups, and the adverse drug reactions, improvement of performance status after treatment were compared and analyzed between the two groups. RESULTS: The overall response rate of the experimental group was 47.5%, which was significantly better than the 25% of the control group (p=0.03). The incidence of adverse drug reactions in the experimental group was 40%, while that in the control group was 30%. The incidence of adverse drug reactions in the experimental group was higher than that in the control group, but there was no statistical significance (p=0.34). Moreover, the improvement rate of performance status score in the experimental group was significantly higher than that in the control group (p=0.00). CONCLUSION: Erlotinib combined with concurrent chemoradiotherapy has been preliminarily proved to be safe and effective in the treatment of locally advanced pancreatic cancer, which can improve the physical condition of patients to a certain extent without significantly increasing adverse reactions.

Selenium ameliorates mercuric chloride-induced brain damage through activating BDNF/TrKB/PI3K/AKT and inhibiting NF-κB signaling pathways.

Mercuric chloride (HgCl2), a heavy metal compound, causes neurotoxicity of animals and humans. Selenium (Se) antagonizes heavy metal-induced organ damage with the properties of anti-oxidation and anti-inflammation. Nevertheless, the molecular mechanism underlying the protective effects of sodium selenite (Na2SeO3) against HgCl2-induced neurotoxicity remains obscure. Therefore, the present study aimed to explore the protective mechanism of Na2SeO3 on HgCl2-induced brain damage in chickens. Morphological observations showed that Na2SeO3 alleviated HgCl2-induced brain tissues damage. The results also showed that Na2SeO3 decreased the protein expression of S100 calcium binding protein B (S100B), and increased the levels of nerve growth factors (NGF), doublecortin domain containing 2 (DCDC2), as well as neurotransmitter to reverse HgCl2-induced brain dysfunction. Further, Na2SeO3 attenuated HgCl2-induced oxidative stress by decreasing the level of malondialdehyde (MDA) and increasing the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC). Mechanistically, Na2SeO3 activated the brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase receptor type B (TrKB)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and suppressed the nuclear factor kappa B (NF-κB) signaling pathway to inhibit apoptosis and inflammation caused by HgCl2 exposure. In summary, Na2SeO3 ameliorated HgCl2-induced brain injury via inhibiting apoptosis and inflammation through activating BDNF/TrKB/PI3K/AKT and suppressing NF-κB pathways.

lncRNA LEF1-AS1 Promotes Proliferation and Induces Apoptosis of Non-Small-Cell Lung Cancer Cells by Regulating miR-221/PTEN Signaling.

INTRODUCTION: LEF1-AS1 is a characterized oncogenic lncRNA in oral cancer. Analysis of TCGA dataset revealed the upregulation of LEF1-AS1 in non-small-cell lung cancer (NSCLC). This study was therefore carried out to investigate the involvement of LEF1-AS1 in NSCLC. METHODS: A total of 62 NSCLC patients were included to collect paired cancer and non-tumor tissues. RT-qPCR was performed to measure levels of LEF1-AS1 and miR-221 expression. Transient transfections were performed to explore the interactions between LEF1-AS1, miR-221 and PTEN. Cell proliferation and apoptosis were analyzed by cell proliferation assay and cell apoptosis assay, respectively. RESULTS: We found that LEF1-AS1 was upregulated in NSCLC patients. In addition, expression of LEF1-AS1 was negatively correlated with the expression of PTEN but positively correlated with the expression of miR-221 in NSCLC tissue samples. In NSCLC cells, overexpression of LEF1-AS1 led to downregulated expression of PTEN but upregulated expression of miR-221, which can directly target PTEN. Overexpression of LEF1-AS1 and miR-221 promoted cancer cell proliferation and inhibited apoptosis. PTEN played an opposite role and reduced the effects of overexpressing LEF1-AS1 and miR-221. CONCLUSION: LEF1-AS1 may promote the proliferation and induce apoptosis of NSCLC cells by regulating miR-221/PTEN signaling.

The proteomic profiling of multiple tissue damage in chickens for a selenium deficiency biomarker discovery.

Over the past decades, substantial advances have been made in both the early diagnosis and accurate prognosis of numerous cancers because of the impressive development of novel proteomic strategies. Selenium (Se) is an essential trace element in humans and animals. Se deficiency could lead to Keshan disease in humans, mulberry heart disease in pigs and damage of tissues including cardiac injury, apoptosis in the liver, reduction in the immune responses in spleen and cerebral lesions in chickens. However, it is well know that plasma biomarkers are not specific and also show alterations in various diseases including those caused by Se deficiency. Therefore, new definition biomarkers are needed to improve disease surveillance and reduce unnecessary chicken losses due to Se deficiency. To identify new biomarkers for Se deficiency, we performed exploratory heart, liver, spleen, muscle, vein, and artery proteomic screens to further validate the biomarkers using Venn analysis, GO enrichment, heatmap analysis, and IPA analysis. Based on the bioinformatics methods mentioned above, we found that differentially expressed genes and proteins are enriched to the PI3K/AKT/mTOR signal pathway and insulin pathway. We further used western blot to detect the expression of proteins related to the two pathways. Results showed that the components of the PI3K/AKT/mTOR signal pathway were definitely decreased in heart, liver, spleen, muscle, vein and artery tissues in the Se deficient group. Expression IGF and IGFBP2 of the insulin pathway were differentially increased in the heart, liver, and spleen in Se deficient group samples and decreased in muscle and artery. In conclusion, 5 proteins, namely PI3K, AKT, mTOR, IGF, and IGFBP2, were differentially expressed, which could be potentially useful Se deficient biomarkers. In the present study, proteomic profiling was used to elucidate protein biomarkers that distinguished Se deficient samples from the controls, which might provide a new direction for the diagnosis and targeted treatment induced by Se deficiency in chickens.

DUSP1 is involved in the progression of small cell carcinoma of the prostate.

Small cell carcinoma of the prostate (SCCP) is a rare and the most aggressive variant of prostate cancer. There is no effective cure or treatment for SCCP. Therefore, there is an urgent need for new therapy to improve the prognosis of patients with SCCP. DUSP1 is a dual specific phosphatase with an increasingly recognized in tumor biology. Altered expression of DUSP1 induced changes in the expression of genes involved in various biological pathways, including cell-cell signaling and angiogenesis. To understand more about the role of DUSP1 in SCCP, we evaluated the biological function and associated regulatory mechanism of DUSP1. In this study, DUSP1 was significantly down-regulated in human SCCP compared with the non-carcinoma tissues (P < 0.05). Overexpression of DUSP1 was found to suppress MAPK signaling and cell proliferation in PC-3 cells. Additionally, silencing of DUSP1 enhanced MAPK signaling and PC-3 cell proliferation. Moreover, it was observed that DUSP1 blocked the phosphorylation of p38 MAPK induced by anisomycin. Taken together, this investigation suggests that DUSP1 is involved in the progression of SCCP and may provide a new therapeutic target for SCCP treatment.

PAFAH1B2 is a HIF1a target gene and promotes metastasis in pancreatic cancer.

Platelet-activating factor acetylhydrolase IB subunit beta (PAFAH1B2) plays important roles in inflammation and anaphylaxis. However, its primary function in pancreatic cancer remains unclear. In the current study, we report that PAFAH1B2 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and correlated inversely with patient survival. PAFAH1B2 overexpression induced epithelial-mesenchymal transition (EMT), migration and invasion in vitro and metastasis in vivo. Conversely, silencing PAFAH1B2 inhibited these aggressive phenotypes. Moreover, PAFAH1B2 overexpression in PDAC cells was directly mediated by HIF1a. PAFAH1B2 expression in PDAC clinical specimens correlated positively with HIF1a expression. Overall, our results defined PAFAH1B2 as a target gene of HIF1a and a critical driver of PDAC metastatic behaviors.

PD-L1 promoter methylation mediates the resistance response to anti-PD-1 therapy in NSCLC patients with EGFR-TKI resistance.

The anti-PD-1/PD-L1 therapy has been demonstrated effective and safe for advanced NSCLC patients, especially for EGFR-TKIs (epidermal growth factor receptor - tyrosine kinase inhibitors) resistant NSCLC (non-small cell lung cancer) patients with EGFR mutations. However, whether the anti-PD-1/PD-L1 therapy also promotes drug resistance as EGFR-TKIs treatment remains unclear. Thus, we conducted the present study to investigate the effects of anti-PD-1 therapy on the expression of PD-L1, which is one important factor mediates the efficacy of anti-PD-1 therapy. To address the expression dynamics of PD-L1 after anti-PD-1 therapy, we first divided the patients into three groups according to the EGFR mutation status (wild type, L858R and T790M mutation). The PD-L1 was highly expressed in the NSCLC tissues than the corresponding normal tissues. After cancer recurrence, the PD-L1 was further up-regulated in patients treated with chemotherapy or EGFR-TKI therapy but decreased in the patients with anti-PD1 therapy. Promoter methylation analysis showed that the secondary NSCLC after cancer recurrence with anti-PD1 therapy had much higher promoter methylation level than the primary cancer tissue or normal tissues. In the mice model, the anti-PD-1 therapy could induce PD-L1 promoter methylation irrespective of EGFR mutation status. Combining DNA hypomethylating agent azacytidine with anti-PD-1 therapy could significantly further reduce the tumor size when comparing with the anti-PD-1 therapy alone. Our results demonstrated that the anti-PD-1 therapy might promote drug resistance through PD-L1 promoter methylation and down-regulation. And combining DNA hypomethylating agent azacytidine with anti-PD-1 therapy might be a promising approach to overcome the resistance.

Down-regulation of microRNA-155 promotes selenium deficiency-induced apoptosis by tumor necrosis factor receptor superfamily member 1B in the broiler spleen.

The aim of this work was to explore the microRNA profile and the effect of microRNA-155 on apoptosis in the spleen of selenium-deficient broilers. We replicated the splenic-apoptotic model in selenium-deficient broilers. In vitro, microRNA-155 oligonucleotides were transfected into lymphocytes and subsequently treated with H2O2. We observed that selenium deficiency altered the microRNA profile and decreased the expression of microRNA-155 in the broiler spleens. Tumor necrosis factor receptor superfamily member 1B was verified as a target of microRNA-155 in the splenocytes. Morphological changes, increased levels of tumor necrosis factor receptor superfamily member 1B, c-Jun N-terminal kinase, Bak, Bax, Cyt-c, caspase9 and caspase3 and decreased levels of Bcl-2 demonstrated that selenium deficiency induced apoptosis in the spleen tissues. In vitro, microRNA-155 m inhibited the levels of ROS and reduced apoptosis compared with microRNA-155i in the lymphocytes. These results suggested that the reduced levels of microRNA-155 due to selenium deficiency could promote oxidative stress-induced apoptosis by increased tumor necrosis factor receptor superfamily member 1B in splenic cells.

lncRNA LINC00152 knockdown had effects to suppress biological activity of lung cancer via EGFR/PI3K/AKT pathway.

Accumulating evidence demonstrates that lncRNAs play important roles in regulating gene expression and are involved in various pathological processes. In our present study, we firstly evaluated lncRNA LINC00152 and EGFR expressions by ISH or IHC methods, and analyzed the correlation between LINC00152 and EGFR with RT-PCR. lncRNA LINC00152 of NSCLC tissues were significantly up-regulation compared with adjacent normal tissues and positively correlated with EGPR. The further cell experiments demonstrated that Linc00152 knockdown had effects of suppression cell proliferation, invasion and migration abilities and improving cell apoptosis and G1 phase rates in both A549 and H1299 cell lines. In the mechanism study, the results were shown that EGFR, PI3K, AKT, Fibronectin and Vimentin proteins expressions were significantly reduced and P21 protein expression was significantly increased in Linc00152 knockdown groups. Our results suggested lncRNA LINC00152 knock-down had anti-tumor effects via EGFR/PI3K/AKT pathway.

Selenium accelerates chicken dendritic cells differentiation and affects selenoproteins expression.

Selenium (Se) promotes immune cell differentiation and improves immune response. Antigen-presenting cells such as dendritic cells (DCs) play an important role in immune system, however, the impact of Se on DCs is still unclear. In this study, we successfully induced and cultured chicken DCs from peripheral blood mononuclear cells by incubating mononuclear cells with 50 ng/mL recombinant chicken granulocyte-macrophage colony stimulating factor and 10 ng/mL recombinant chicken interleukin-4 for total 9 days. In + Se group, we added 10-7 mol/L sodium selenite from the first day of cell culture. The results showed that Se supplementation expedited and increased the expression of cell surface markers including CD11c, CD40, CD86, and MHC II. Principal component analysis showed that the expression of selenoproteins SelW, SelK, Dio3, GPX1, GPX2, SelN, SelS, SelH in chicken DCs was highly correlated, and SelW had highest correlation with the cell surface markers MHC II and CD11c. In conclusion, Se accelerates the differentiation and maturation of chicken DCs. Se regulates the differentiation and maturation of chicken DCs by selenoproteins. Selenoproteins has closely correlated to surface markers of chicken DCs.

The Functions of Antioxidants and Heat Shock Proteins Are Altered in the Immune Organs of Selenium-Deficient Broiler Chickens.

Despite increasing evidence indicating the essential involvement of selenium (Se) in the immune system, the effect of Se deficiency on the regulation of oxidative stress and heat shock proteins (Hsps) in broiler chickens is still unclear. In the present study, we established an exudative diathesis (ED) broiler chicken model caused by Se deficiency. We then analyzed histological observations and detected the expression levels of Hsps and antioxidant indexes in immune tissues. The antioxidant function declined remarkably, and most of the Hsp expression levels increased significantly in the spleen, thymus, and bursa of Fabricius of the broiler chicks with ED (except the messenger RNA (mRNA) levels of Hsp27, Hsp40, and Hsp70, which decreased in thymus tissues from the treatment groups); therefore, constitutive oxidation resistance and higher Hsps in broiler chicks with ED caused defects in immune organ morphology and function, as evidenced by abnormal histological structures: red pulp broadening and lymphocytes in the cortex and medulla of the thymic lobule decreased distinctly and distributed loosely. These results underscore the importance of Se in establishing an immune organ microenvironment conducive to normal function.

Selenium Deficiency Mainly Influences Antioxidant Selenoproteins Expression in Broiler Immune Organs.

Selenoprotein has many functions in chicken, and the expression of selenoproteins is closely associated with the selenium (Se) level. However, little is known about the expression patterns of selenoproteins in chicken immune organs. Here, we investigated the effect of dietary Se deficiency on the expressions of 23 selenoproteins in broiler immune organs. In this study, 150 broilers were randomly divided into two groups (75 chickens per group). The chickens were maintained either on a diet supplemented with Se through the addition of 0.2 mg/kg of Se (C group) via sodium selenite or on a Se-deficient granulated diet (L group) until the broilers exhibited an onset of exudative diathesis (ED). Following euthanasia, the samples from the immune tissues (including the spleen, thymus, and bursa of Fabricius) were quickly collected, and the messenger RNA (mRNA) expression levels of 23 selenoproteins were examined by real-time quantitative PCR and analyzed using principal component analysis. The results showed that Se deficiency decreased the mRNA levels of 23 selenoproteins in the thymus, spleen, and bursa of the Fabricius tissues of broiler chickens. Furthermore, we found that among 23 selenoproteins, the mRNA levels of Dio1 in the thymus, Txnrd2 in the spleen, and Txnrd3 in the bursa of Fabricius decreased significantly (90.9 %, 83.3 %, and 96.8 %, respectively). In addition, the principal component analysis (PCA) results suggested that Se deficiency mainly influenced the expression of antioxidative selenoproteins, especially glutathione peroxidases (Gpxs), thioredoxin reductases (Txnrds), and iodothyronine deiodinases (Dios) in chicken immune organs. The results of this study are valuable for understanding the relevance of selenoprotein activity in vivo.

Biodistribution characteristics and SPECT imaging of (99m)Tc-RET and (99m)Tc-REG in human lung cancer xenografts.

OBJECTIVE: To investigate the biodistribution and single-photon emission computed tomography (SPECT) imaging of (99m)Tc-labeled arginine-glutamic acid-threonine (RET) and arginine-glutamic acid-glycine (REG) in nude mice bearing human lung cancer xenografts. MATERIALS AND METHODS: RET and REG were labeled directly with (99m)Tc and their binding efficiency to tumor cells was measured in human nonsmall cell lung cancer H1299 cells. After intravenously injecting (99m)Tc-RET and (99m)Tc-REG into normal mice and nude mice bearing human lung cancer xenografts, their biodistribution was measured at different postinjection times, and percentages of injected dose per gram tissue (% ID/g) of organs of interest were calculated. The mice bearing H1299 lung cancer xenografts were scanned by SPECT at different times following the (99m)Tc-RET or (99m)Tc-REG injection. RESULTS: The radiochemical purity of (99m)Tc-RET and (99m)Tc-REG was 93.15%±2.02% and 92.90%±2.86%, respectively. The binding rate of (99m)Tc-RET and (99m)Tc-REG to H1299 cells was 3.56%±0.37% and 2.32%±0.31%, respectively. The uptake of (99m)Tc-RET and (99m)Tc-REG in tumor was 4.96±1.05% ID/g at 4 hours postinjection and 1.95±0.73% ID/g at 2 hours postinjection, respectively. Tumors in nude mice could be best imaged at 4.5-6 hours postinjection of (99m)Tc-RET. CONCLUSION: (99m)Tc-RET has a higher binding rate to H1299 cells than (99m)Tc-REG and might be used as a potential lung cancer imaging agent.

Autophagy is upregulated in brain tissues of pigeons exposed to avermectin.

Avermectin (AVM) is used in agriculture and veterinary medicine for the prevention of parasitic diseases; AVM is the active component of some insecticidal and nematicidal products. Residues of AVM drugs or their metabolites in livestock feces have toxic effects on non-target aquatic and terrestrial organisms. In this study, changes in the levels of autophagy related genes and ultrastructure in pigeon brain tissues after subchronic exposure to AVM for 30, 60 and 90 d were investigated. The decrease in the mRNA levels of TORC1 and TORC2 and increase in the mRNA levels of LC3, Beclin 1, Dynein, ATG5 and ATG4B and the increase in the protein levels of LC3, Beclin 1 and Dynein in a dose- and time-dependent manner in the pigeon brain were observed. The number of autophagic vacuoles in the cerebrum, cerebellum and optic lobe increased significantly with the concentration of AVM and the exposure time. We found that the changes in the levels of autophagy related genes and the ultrastructure in the cerebrum were more obvious than in the cerebellum and the optic lobe. The results suggest that AVM could induce autophagy in pigeon brain tissues. The information presented in this study is helpful for understanding the mechanism of AVM-induced autophagy in birds.

Effects of avermectin on immune function and oxidative stress in the pigeon spleen.

Avermectin (AVM) is a pesticide that can accumulate in the environment through spray-drift, runoff or field drainage. Residues of AVM or its metabolites in livestock feces have toxic effects on non-target aquatic and terrestrial organisms. In this study, changes in oxidative stress and immunity in pigeon spleen tissues were detected after subchronic exposure to AVM for 30, 60, and 90 days. In pigeon spleen, the activities of total anti-oxidation capability (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased significantly, whereas the levels of malondialdehyde (MDA), protein carbonyl (PCO), and DNA-protein crosslink (DPC) coefficients increased. Additionally, obvious ultrastructure alterations were observed. These results indicated that AVM induced oxidative stress and damaged the normal structure of spleen cells. The exposure to AVM could lead to increases in the mRNA levels of interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and interleukin-4 (IL-4), as well as a decrease in the mRNA level of interferon-γ (IFN-γ), in a dose-time-dependent manner in pigeon spleen. The results imply that AVM induces immunosuppression in the spleen tissue of pigeons. The information presented in this study may be helpful for understanding the mechanism of AVM-induced immunotoxicity in birds.