As the aging population increases, cognitive impairment is emerging as a growing health issue worldwide. Low selenium status has been reported to correlate with cognitive decline in older adults. Nonetheless, the impact of prolonged selenium deficiency on cognitive function in adult mice and the underlying mechanisms remain poorly understood. In this research, male C57BL/6 J mice were given either a normal diet (0.2 mg/kg Se) or a selenium-deficient diet (0.02 mg/kg Se) for 24 weeks to evaluate the impact of long-term selenium insufficiency on their cognitive abilities. We performed hippocampus transcriptome sequencing, real-time PCR, Golgi-Cox staining, transmission electron microscopy, western blotting, and untargeted brain metabolomics to uncover the underlying regulatory mechanism. We found that chronic selenium deficiency impaired the capabilities of object recognition, spatial memory, and self-caring in mice, and disrupted the expression of key genes related to cognitive behavior, dendrite morphogenesis, and synaptic plasticity. Additionally, prolonged selenium deficiency compromised neurite integrity, decreased dendritic spine density, impaired synaptic ultrastructure, and reduced synaptic protein expression. Brain metabolomics revealed that differential metabolites (methylmalonic acid, N-acetyl-1-aspartylglutamic acid, and S-adenosylmethionine) may be involved in the process of cognitive impairment. These findings suggest that perturbation in cognition-related transcriptome profiles, lesions in neurites and synapses, and remodeling of the brain metabolic pattern are involved in the cognitive impairment induced by long-term selenium deficiency. Our study offers a new perspective on the pathogenesis of cognitive impairment, highlighting the critical role of selenium supplementation in maintaining healthy cognitive function.

Dental pulp stem cells (DPSCs), a subset of tooth-derived mesenchymal stem cells (MSCs), demonstrate significant promise in clinical stem cell therapy. However, prolonged in vitro expansion commonly results in compromised stemness, limiting therapeutic efficacy. Thus, maintaining the stemness of DPSCs during expansion and culture is a key challenge for regenerative medicine. In the current study, the impact of simulated microgravity (SMG) on DPSC stemness was investigated using the three-dimensional clinostat Cellspace-3D. After SMG treatment for 3 days, DPSCs demonstrated markedly enhanced replicative activity, proliferation efficiency, self-renewal capacity, and effective inhibition of the senescence process. Under specific differentiation induction conditions, DPSCs in the SMG group exhibited superior osteogenic, adipogenic, chondrogenic, and neural differentiation potentials. Additionally, DPSCs exhibited higher expression levels of the MSC surface markers Stro-1 and CD146 and stemness maintenance-related genes Oct4, Nanog, and Sox2 in the SMG group compared to those from the normal gravity (NG) group. To elucidate the potential molecular mechanisms by which SMG influences the stemness of DPSCs, transcriptome sequencing of total RNA was performed, and identified that differentially expressed genes (DEGs) are closely associated with the MAPK signaling pathway. Further verification experiments demonstrated that the MAPK/ERK signaling pathway was activated in the SMG group. In conclusion, SMG effectively maintains the stemness of DPSCs cultivated in vitro, and its mechanism of action may be associated with the activation of the MAPK/ERK signaling pathway.

Aim or purpose: To explore how neutrophil extracellular traps (NETs) and phosphatidylserine exposure contribute to hypercoagulability in periodontitis with type 2 diabetes . Materials and methods: Sixty-four participants were divided into groups with periodontitis (CP), T2D, periodontitis with type 2 diabetes (DP), and a healthy control group (CTR). Participants were recruited from a university-affiliated hospital in Harbin between December 2023 and December 2024. The study was approved by the relevant ethics committee. Coagulation profiles were assessed using coagulation time and fibrin generation tests. Confocal microscopy and flow cytometry were employed to measure PS-exposed cells and NETs in blood samples. The impact of NETs on endothelial cells was evaluated through western blot, confocal microscopy, and angiogenesis assays. Results: DP patients showed significantly shorter coagulation times, higher fibrinogen levels, and increased numbers of blood cells (e.g. platelets and neutrophils) with phosphatidylserine (PS) exposure, along with increased NETs release. PS+ platelets were found to stimulate NETs release more than microparticle-poor plasma. NETs damage vascular endothelial cells, leading to increased VCAM-1, decreased VE-cadherin, actin reorganization, reduced tube formation, and higher procoagulant activity in endothelial cells. These effects were reduced by DNase I inhibition of NETs. Conclusions: In DP patients, PS+ platelets trigger neutrophils to release excess NETs, contributing to a pro-thrombotic state by damaging endothelial cells.

BACKGROUND & OBJECTIVES:Relatively little is known about mitochondrial ROS (mtROS)-mediated neutrophil extracellular traps (NETs) release. The aim of this study was to investigate whether the elevated NETs in liver cirrhosis were induced by platelets via mtROS and their effects on the cirrhotic coagulation system. METHODS:Patients with cirrhosis (n = 103) and healthy controls (n = 19) were included in the study. Platelet-induced NETosis was measured by immunofluorescence staining, confocal microscopy, flow cytometry, and microplate assays. NETs' procoagulant activity was assessed using purified coagulation complex assays and thrombin formation in cirrhotic plasma. RESULTS:NETs' levels were elevated in Child-Pugh B and C patients. Their platelets or high mobility group box 1 (HMGB1) increased NETs release of autologous neutrophils. Cirrhotic neutrophils had an increase in mtROS levels, which were enhanced by autologous platelets. Importantly, Mito TEMPO (a mitochondrial ROS inhibitor) inhibited platelet-induced NETs' formation. Higher levels of HMGB1 on platelets and neutrophil autophagy were detected in Child-Pugh B and C patients. Their platelets or HMGB1 increased autophagy levels of autologous neutrophils. Furthermore, anti-HMGB1, anti-RAGE (receptor for advanced glycation endproducts) antibodies, and wortmannin inhibited platelet-induced autophagy and NETs formation. Subsequently, we found some differences between platelet- and PMA-induced NETosis, and further studied the dynamic changes of platelet-mediated NETosis. Lastly, these elevated NETs increased FXa, thrombin, and fibrin formation, shortened coagulation time, decreased thrombomodulin levels on endothelial cells, and impaired thrombomodulin activity. CONCLUSIONS:Cirrhotic platelets induced NETs formation through mtROS and autophagy, which heightened the procoagulant activity and impaired the anticoagulant activity of thrombomodulin.

Glycolysis supports mesenchymal stem cell (MSC) proliferation and sustains their undifferentiated state by maintaining energy supply and limiting apoptosis. The rapid advancement of space life sciences has spurred considerable interest in the effects of microgravity on stem cells. However, the contribution of glycolytic metabolism to apoptotic regulation under simulated microgravity (SMG) remains unclear. This study examined the influence of SMG on glycolytic activity and apoptosis in human dental pulp stem cells (hDPSCs). Lactic acid and glucose measurements were used to evaluate glycolytic flux, while transcript levels of HK2, PKM2, and LDHA were quantified by qPCR, HK2 and PKM2 protein expression was assessed by Western blotting, and annexin V-FITC/PI staining combined with immunoblotting of apoptosis-related proteins (BAX, BCL-2, and cleaved caspase-3) was performed to assess cell death. SMG markedly increased glycolytic capacity and attenuated apoptosis in hDPSCs. SphK1 expression was also elevated, indicating a role in cell survival. Pharmacological inhibition of SphK1 with PF-543 reduced both glycolysis and the antiapoptotic effect, implicating SphK1 as a critical regulator of these processes. Inhibition of glycolysis by 2-DG further increased apoptosis, confirming the protective role of glycolytic metabolism under SMG. These findings demonstrate that SMG enhances glycolysis and limits apoptosis in hDPSCs via SphK1 upregulation, suggesting that microgravity conditions may augment stem cell survival and function.

The aim of this study is to explore how neutrophil extracellular traps (NETs) and phosphatidylserine exposure contribute to hypercoagulability in periodontitis with type 2 diabetes (T2D). Ninety-six participants were divided into groups with periodontitis (CP), T2D, periodontitis with type 2 diabetes (DP), and a healthy control (CTR). Coagulation profiles were assessed using coagulation time and fibrin generation tests. Confocal microscopy and flow cytometry measured phosphatidylserine (PS)-exposed cells and NETs in blood samples. The impact of NETs on endothelial cells was evaluated through Western blot, confocal microscopy, and angiogenesis tests. We evaluated the NETs levels in patients before and after treatment through blood glucose control or periodontitis treatment. DP patients showed shorter coagulation times, higher fibrinogen levels, and more blood cells (e.g., platelets and neutrophils) with PS exposure, along with increased NETs release. Activated platelets were found to stimulate NETs release more than microparticle-poor plasma. NETs damage vascular endothelial cells, leading to increased vascular cell adhesion molecule-1 (VCAM-1), decreased vascular endothelial cadherin (VE-cadherin), actin reorganization, reduced tube formation, and higher procoagulant activity in endothelial cells. After periodontal treatment or blood sugar control, the levels of NETs decreased significantly in patients with DP. In patients with DP, activated platelets trigger neutrophils to release excess NETs, which create a pro-thrombotic state by damaging endothelial cells. Small-scale clinical trials underscore the value of controlling local infection and hyperglycemia as first-line “NET-modulating” strategies. The hypercoagulability of DP patient can be partially explained by the activated platelet-promoted excess NETs providing a scaffold for clotting factors, damaging endothelial cells intercellular connections, converting of endothelial cells to pro-coagulant phenotype, and impairing of endothelial cells tube formation capacity. Blood sugar control and periodontal treatment can regulate the levels of NETs which represents the generation of new promising DP treatment options. In the future, efforts should be made to develop therapeutic strategies targeting NETs or PS.

BACKGROUND:The aim of this study is to explore how neutrophil extracellular traps (NETs) and phosphatidylserine exposure contribute to hypercoagulability in periodontitis with type 2 diabetes (T2D). METHODS:Ninety-six participants were divided into groups with periodontitis (CP), T2D, periodontitis with type 2 diabetes (DP), and a healthy control (CTR). Coagulation profiles were assessed using coagulation time and fibrin generation tests. Confocal microscopy and flow cytometry measured phosphatidylserine (PS)-exposed cells and NETs in blood samples. The impact of NETs on endothelial cells was evaluated through Western blot, confocal microscopy, and angiogenesis tests. We evaluated the NETs levels in patients before and after treatment through blood glucose control or periodontitis treatment. RESULTS:DP patients showed shorter coagulation times, higher fibrinogen levels, and more blood cells (e.g., platelets and neutrophils) with PS exposure, along with increased NETs release. Activated platelets were found to stimulate NETs release more than microparticle-poor plasma. NETs damage vascular endothelial cells, leading to increased vascular cell adhesion molecule-1 (VCAM-1), decreased vascular endothelial cadherin (VE-cadherin), actin reorganization, reduced tube formation, and higher procoagulant activity in endothelial cells. After periodontal treatment or blood sugar control, the levels of NETs decreased significantly in patients with DP. CONCLUSIONS:In patients with DP, activated platelets trigger neutrophils to release excess NETs, which create a pro-thrombotic state by damaging endothelial cells. Small-scale clinical trials underscore the value of controlling local infection and hyperglycemia as first-line "NET-modulating" strategies. PLAIN LANGUAGE SUMMARY:The hypercoagulability of DP patient can be partially explained by the activated platelet-promoted excess NETs providing a scaffold for clotting factors, damaging endothelial cells intercellular connections, converting of endothelial cells to pro-coagulant phenotype, and impairing of endothelial cells tube formation capacity. Blood sugar control and periodontal treatment can regulate the levels of NETs which represents the generation of new promising DP treatment options. In the future, efforts should be made to develop therapeutic strategies targeting NETs or PS.

SARS-CoV-2 can directly or indirectly damage endothelial cells. Endothelial injury, especially phosphatidylserine (PS) exposure on the outer membrane of cells, can more easily promote thrombosis. Type 2 diabetes(T2D) patients were more susceptible to COVID-19, they had more severe symptoms, higher risk of thrombotic complications, and longer duration of post-COVID-19 sequelae. This review provided a detailed overview of the mechanisms underlying endothelial dysfunction in T2D patients with COVID-19 (including long COVID), which may be influenced by hyperglycemia, hypoxia, and pro-inflammatory environments. The mechanisms of thrombosis in T2D patients with COVID-19 are also explored, particularly the effects of increased numbers of PS-exposing particles, blood cells, and endothelial cells on hypercoagulability. Given the high risk of thrombosis in T2D patients with COVID-19, early antithrombotic therapy can both minimize the impact of the disease on patients and maximize the chances of improvement, thereby alleviating patient suffering. We provided detailed guidance on antithrombotic drugs and dosages for mild, moderate, and severe patients, emphasizing that the optimal timing of thromboprophylaxis is a critical factor in influencing prognosis. Considering the potential interactions between antidiabetic, anticoagulant, and antiviral drugs, we proposed practical and comprehensive management recommendations to supplement the incomplete efficacy of vaccines in the diabetic population, reduce the incidence of post-COVID-19 sequelae, and improve patient quality of life.

The microbiota–gut–liver axis has emerged as an important player in developing nonalcoholic steatohepatitis (NASH), a type of nonalcoholic fatty liver disease (NAFLD). Higher mushroom intake is negatively associated with the prevalence of NAFLD. This study examined whether lentinan, an active ingredient in mushrooms, could improve NAFLD and gut microbiota dysbiosis in NAFLD mice induced by a high-fat (HF) diet. Dietary lentinan supplementation for 15 weeks significantly improved gut microbiota dysbiosis in HF mice, evidenced by increased the abundance of phylum Actinobacteria and decreased phylum Proteobacteria and Epsilonbacteraeota. Moreover, lentinan improved intestinal barrier integrity and characterized by enhancing intestinal tight junction proteins, restoring intestinal redox balance, and reducing serum lipopolysaccharide (LPS). In the liver, lentinan attenuated HF diet-induced steatohepatitis, alteration of inflammation–insulin (NFκB-PTP1B-Akt-GSK3β) signaling molecules, and dysregulation of metabolism and immune response genes. Importantly, the antihepatic inflammation effects of lentinan were associated with improved gut microbiota dysbiosis in the treated animals, since the Spearman's correlation analysis showed that hepatic LPS-binding protein and receptor (Lbp and Tlr4) and pro- and antiinflammatory cytokine expression were significantly correlated with the abundance of gut microbiota of phylum Proteobacteria, Epsilonbacteraeota and Actinobacteria. Therefore, lentinan supplementation may be used to mitigate NAFLD by modulating the microbiota–gut–liver axis.

BACKGROUND:Nonalcoholic steatohepatitis (NASH) patients are at a high risk of developing venous thromboembolism, with a high rate of morbidity and mortality. The role of neutrophil extracellular traps (NETs) in procoagulant activity (PCA) in patients with NASH remains unclear. Our study aimed to investigate the formation of NETs in NASH patients stimulated by specific pro-inflammatory factors. Moreover, we evaluated the pivotal role of NETs in the induction of hypercoagulability in NASH and the interaction between NETs and endothelial injury.METHOD:The levels of the NETs biomarkers were evaluated in the plasma samples of 27 NASH patients and 18 healthy subjects. The formation of NETs was visualized using immunofluorescence microscopy. The PCA of the NETs was assessed using coagulation time, purified coagulation complex, and fibrin formation assays. Confocal microscopy was further used to evaluate the interactions between the NETs and HUVECs.RESULTS:The levels of NETs markers in the plasma of NASH patients were significantly higher than healthy controls. NETs derived from NASH enhanced thrombin and fibrin formation and significantly reduced CT (p<0.05). The mixture of IL-6 and TNF-α triggered the NETs release in the plasma rather than them alone. Additionally, the NETs exerted cytotoxic effects on the endothelial cells, converting them to a procoagulant and pro-inflammatory phenotype, and DNase I could reverse these effects.CONCLUSION:Our results revealed the primary role of NETs in promoting the hypercoagulable state in NASH patients. Methods that prevent the formation of NETs may be a novel approach for the prevention and treatment of NASH.

Selenium deficiency has been considered to increase the risk of gestational complications. Our previous work showed that maternal selenium deficiency suppressed proliferation, induced autophagy dysfunction, and apoptosis in the placenta of mice. However, other effects of maternal selenium deficiency on the placenta and the underlying mechanisms remain unclear. In the present study, dietary selenium deficiency in dams significantly suppressed glutathione peroxidase (GSH-Px) activity, total antioxidant capacity (T-AOC), and increased malondialdehyde (MDA) content in the placentae, confirming the oxidative stress in the placenta. By transcriptome sequencing analysis, the DEGs were involved in many biological processes, including ion transport, lipid metabolic process, immune response, transmembrane transport, and others. According to the KEGG analysis, the DEGs were primarily enriched in metabolic pathways, PI3K-Akt signaling pathway, and others. Among these, the steroid hormone biosynthesis pathway enriched the most DEGs. Hsd3b1, an ER enzyme involved in progesterone synthesis, was validated downregulated. Consistently, the progesterone content in the serum of the selenium-deficient group was decreased. Ion transporters and transmembrane transporters, such as Heph, Trf, Slc39a8, Slc23a1, Atp7b, and Kcnc1, were reduced in the selenium-deficient placentae. Immune response-related genes, including Ccl3, Ccl8, Cxcl10, and Cxcl14, were increased in the selenium-deficient placentae, along with an increase in macrophage number. These results suggested that maternal selenium deficiency may impair progesterone biosynthesis, reduce nutrient transporters expression, and promote immune response by increasing the oxidative stress of the placentae. This present study provides a novel insight into the possible cause of placenta disorder during pregnancy.

Circulating neutrophil extracellular traps (NETs) resistant to t-PA have not been studied completely although NETs in thrombi may contribute to tissue plasminogen activator (t-PA) resistance. This research intended to elucidate whether circulating NETs are associated with t-PA resistance and the underlying mechanism. The levels of NETs were detected in the circulating neutrophils, ischemic brain tissue of acute ischemic stroke (AIS) patients, and transient middle cerebral artery occlusion (tMCAO) models. NET formation in blood, thrombi, and ischemic brain tissue of mice were analyzed by immunofluorescence. Exposed phosphatidylserine (PS) was assessed using flow cytometry and confocal microscopy. Procoagulant activity (PCA) was evaluated using fibrin formation assays, thrombin, and purified coagulation complex. The plasma levels of NETs in AIS patients were significantly higher than those in healthy individuals. After thrombolysis, a significant increase was noted in NET markers in no-improvement patients, while the changes in improvement patients were not significant. Importantly, NETs were decorated with von Willebrand factor (vWF) and plasminogen activator inhibitor-1 (PAI-1) in the blood and thrombi, which could reverse the fibrinolytic effects. In addition, NETs activated platelets (PLTs) and endothelial cells (ECs), stimulating a procoagulant phenotype and facilitating vWF and PAI-1 release. DNase I, activated protein C (APC), and sivelestat markedly inhibited these effects. Furthermore, targeting NETs protected mice from tMCAO-induced cerebral ischemia, possibly by regulating vWF and PAI-1. In summary, NETs may contribute to t-PA resistance in AIS through activation of PLTs and ECs. Strategies against NETs may present a promising therapeutic approach to improve the thrombolysis efficiency of t-PA in AIS patients.

Selenium deficiency is thought to be associated with the occurrence of gestational complications. However, the underlying mechanism of selenium deficiency impairs placental function remains unclear. In this study, female mice were separately supplemented with a Se-deficient (0.02 mg/kg Se) or control diet (0.2 mg/kg Se) for 12 weeks before mating and throughout gestation. Maternal liver and placentas were collected at embryonic day 15.5 and analyzed for Se content. Oxidative stress status, proliferation capability, autophagy, and apoptosis of the placenta were determined. We found that maternal selenium deficiency decreased placental Se concentration and some antioxidant selenoproteins expressions. The concentrations of catalase and glutathione in selenium-deficient placentas were reduced, along with an increase in hydrogen peroxide (H2O2) content. Selenium deficiency inhibited the expression of proliferating cell nuclear antigen. Autophagosomes, autophagolysosomes, and upregulation of autophagy-related protein microtubule-associated protein 1 light chain 3 alpha II (LC3B), Beclin1, PTEN-induced putative kinase 1 (PINK1), and Parkin were found in the selenium-deficient trophoblasts. Autophagic substrate p62/sequestosome 1 was surprisingly increased, indicating autophagy flux dysfunction. Selenium deficiency increased expressions of B cell leukemia/lymphoma 2 associated X protein (Bax), cleaved caspase-9/-3, and decreased the B cell leukemia/lymphoma 2 (Bcl2) level. Moreover, typical apoptotic ultrastructure and apoptosis-positive cells were observed in the selenium-deficient placenta. Our results suggested that maternal selenium deficiency impaired placental proliferation, induced autophagy dysfunction and apoptosis via increasing oxidative stress, and the Akt/mechanistic target of rapamycin (mTOR) pathway involved in this process. This study revealed a novel mechanism by which maternal selenium deficiency caused impairment of the placenta.

COVID-19 is widely epidemic in the world and poses a great threat to our life. Coagulopathy is one of the major characteristics in the COVID-19 patients. A growing number of studies have found that the severe COVID-19 patients have thrombotic microangiopathy and thromboembolism. Coagulopathy associated with increased risk of death in the patients. Unfortunately, the mechanism of coagulopathy is not clearly addressed. Understanding the pathophysiological mechanism of COVID-19 thrombosis and improving the coagulopathy through efficient treatment may help to stop disease progression, reduce mortality and sequelae. In severe COVID-19 patients, inflammation, cytokine storm, and coagulation are closely related, which together cause blood congestion and thrombosis. Many cytokines activate blood cells, expressing activating factors or releasing activated microparticles, and then accelerating thrombosis. However, the role of blood cells is not well understood in COVID-19 patients. In addition, cytokines stimulate endothelial cells, transforming them into a procoagulant phenotype. Therefore, determine their role and propose new strategies for the prevention and treatment of thrombosis in severe COVID-19 patients. We outline the major events of coagulopathies, discuss the role of blood and endothelial cells in thrombosis, to formulate a new anticoagulation protocol.

COVID-19 has swept quickly across the world with a worrisome death toll. SARS-CoV-2 infection induces cytokine storm, acute respiratory distress syndrome with progressive lung damage, multiple organ failure, and even death. In this review, we summarize the pathophysiologic mechanism of neutrophil extracellular traps (NETs) and hypoxia in three main phases, focused on lung inflammation and thrombosis. Furthermore, microparticle storm resulted from apoptotic blood cells are central contributors to the generation and propagation of thrombosis. We focus on microthrombi in the early stage and describe in detail combined antithrombotic with fibrinolytic therapies to suppress microthrombi evolving into clinical events of thrombosis. We further discuss pulmonary hypertension causing plasmin, fibrinogen and albumin, globulin extruding into alveolar lumens, which impedes gas exchange and induces severe hypoxia. Hypoxia in turn induces pulmonary hypertension, and amplifies ECs damage in this pathophysiologic process, which forms a positive feedback loop, aggravating disease progression. Understanding the mechanisms paves the way for current treatment of COVID-19 patients.

• Excessive fluoride inhibited division and induced apoptosis of thymocytes. • Excessive fluoride induced activation of PERK and IRE1 signaling in thymocytes. • PERK and IRE1 signaling induced by fluoride plays a key role in immunosuppression.

The tRNA selenocysteine 1 associated protein 1 (Trnau1ap, initially named SECp43) is involved in Selenocysteine (Sec) biosynthesis and incorporation into selenoproteins, which play a key role in biological processes, such as embryonic development. We previously reported that downregulation of Trnau1ap inhibited proliferation of cardiomyocyte-like H9c2 cells. However, the effects of Trnau1ap on cell proliferation and migration of embryonic development are not known, and the mechanisms remain elusive. Herein, lentiviral shRNA vectors were transfected in NIH3T3, JEG-3 and Bewo cells (embryonic, trophoblast and placental cells). We found that knockdown of Trnau1ap resulted in reduced expression levels of selenoproteins. The data of Cell Count Kit-8 (CCK-8) assay and wound scratch assay revealed the proliferation and migration rates were reduced in the Trnau1ap-shRNA groups. Furthermore, western blot analysis showed that the phosphorylation level of Akt in the phosphatidylinositol 3-kinase (PI3K)/Akt pathway was attenuated. These results indicate that Trnau1ap plays an important role in regulation of cell proliferation and migration through the PI3K/Akt signaling pathway, as well as being essential for embryonic development by regulating the expression of selenoproteins.

Selenoprotein K (SelK), a member of selenoprotein family, is identified as a single endoplasmic reticulum (ER) transmembrane protein. Although over-expression of SelK inhibits adherence and migration of human gastric cancer BGC-823 cells, the effects of SelK in human choriocarcinoma (CCA) are not well understood. In this study, the expression levels of SelK in three CCA cell lines, BeWo, JEG-3, and JAR, were examined. The effects of silencing or over-expressing SelK on expression of human chorionic gonadotropin beta subunit (β-hCG) were detected by western blotting. The results show that the protein level of β-hCG was reciprocally regulated by down- or up-regulation of SelK (*P < 0.05; #P < 0.05). The proliferative, migratory, and invasive capabilities of JEG-3 cells with reduced or over-expressed SelK were then tested using the cell counting kit-8 (CCK-8), wound healing, and transwell chamber assays. We found that these cellular activities were markedly increased by the loss of SelK in JEG-3 cells. Conversely, over-expressing SelK in JEG-3 cells suppressed these phenotypes. In addition, SelK expression after down- or up-regulation of β-hCG was also measured. Surprisingly, we found that level of SelK was affected by β-hCG (*P < 0.05; #P < 0.05). The proliferation, migration, and invasion were determined in JEG-3 cells after each over-expression and reduction of β-hCG. The results confirmed that β-hCG functions as a promoter of human choriocarcinoma. Furthermore, ERK/p38 MAPK and Akt signaling pathways were found to involve in these cellular functions. This work suggests that SelK may act as a tumor suppressor in human choriocarcinoma cells by negatively regulating β-hCG expression via ERK, p38 MAPK, and Akt signaling pathways. These findings revealed that selenoprotein K may serve as a novel target for human choriocarcinoma therapy in vitro.

Oxidative stress induces apoptosis in cardiac cells, and antioxidants attenuate the injury. MicroRNAs (miRNAs) are also involved in cell death; therefore, this study aimed to investigate the role of miRNAs in the effect of selenium on oxidative stress‐induced apoptosis. The effects of sodium selenite were analyzed via cell viability, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) concentration. Flow cytometry was used to evaluate cell apoptosis. Fura‐2AM was used to calculate intracellular Ca2+ concentration. Sodium selenite could ameliorate hydrogen peroxide (H2O2)‐induced cell apoptosis and improve expression levels of glutathione peroxidase and thioredoxin reductase. Pretreatment with sodium selenite improved SOD activity and reduced MDA concentration. Treatments with H2O2 or sodium selenite decreased miR‐328 levels. MiR‐328 overexpression enhanced cell apoptosis, reduced ATP2A2 levels, and increased intracellular Ca2+ concentration, while inhibition produced opposite effects. MiR‐328 might be involved in the effect of sodium selenite on H2O2‐induced cell death in H9c2 cells.

INTRODUCTION:Selenocysteine insertion binding protein 2 (SECISBP2) plays a vital role in selenocysteine incorporation into selenoprotein in many creatures. However, the impact of SECISBP2 in development of trophoblast cells remains unclear. The aim of this study was to investigate the roles of SECISBP2 in human trophoblast cells and the underlying molecular mechanism.METHODS:Low-expression of SECISBP2 in trophoblast cells was achieved by transfection with siRNAs. Then protein levels of selenoproteins and MDA content were performed to evaluate the levels of oxidative stress. CCK-8 assays, transwell chamber assay and wound healing assay were used to assess the trophoblast proliferation, migration/invasion. Production of β-hCG and progesterone was quantified to estimate the effect of SECISBP2 on hormone secretion. The underlying mechanisms were also examined in two trophoblast cell lines.RESULTS:Knockdown of SECISBP2 clearly reduced the levels of some selenoproteins, including GPx1, SelK, Dio2 (p < 0.05). On the contrary, the levels of oxidative stress presented as MDA content markedly increased in two cell lines (p < 0.05). In addition, proliferative, migratory and invasive abilities of trophoblast cells were significantly suppressed when SECISBP2 was partially deleted (p < 0.05). Furthermore, silencing SECISBP2 reduced the expression of β-hCG at mRNA and protein levels (p < 0.05), and inhibited the production of progesterone (p < 0.01). The PI3K/Akt and ERK signaling pathway were found to involve in the progress (p < 0.05).DISCUSSION:Our results suggest that the decreased SECISBP2 impaired trophoblast proliferation, migration/invasion and hormone secretion through inactivation of the PI3K/Akt and ERK signaling pathway may provide an insight into the preeclampsia and miscarriage induced by selenium deficiency.