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1.
J. physiol. biochem ; 80(1): 27-39, Feb. 2024. ilus, graf
Article in English | IBECS | ID: ibc-229938

ABSTRACT

Cardiovascular disease due to atherosclerosis is one of the leading causes of death worldwide; however, the underlying mechanism has yet to be defined. The sodium-dependent glucose transporter 2 inhibitor (SGLT2i) empagliflozin is a new type of hypoglycemic drug. Recent studies have shown that empagliflozin not only reduces high glucose levels but also exerts cardiovascular-protective effects and slows the process of atherosclerosis. The purpose of this study was to elucidate the mechanism by which empagliflozin ameliorates atherosclerosis. Male apolipoprotein E-deficient (ApoE−/−) mice were fed a high-fat Western diet to establish an atherosclerosis model. The area and size of atherosclerotic lesions in ApoE−/− mice were then assessed by performing hematoxylin–eosin (HE) staining after empagliflozin treatment. Concurrently, oxidized low-density lipoprotein (oxLDL) was used to mimic atherosclerosis in three different types of cells. Then, following empagliflozin treatment of macrophage cells (RAW264.7), human aortic smooth muscle cells (HASMCs), and human umbilical vein endothelial cells (HUVECs), western blotting was applied to measure the levels of autophagy-related proteins and proinflammatory cytokines, and green fluorescent protein (GFP)-light chain 3 (LC3) puncta were detected using confocal microscopy to confirm autophagosome formation. Oil Red O staining was performed to detect the foaming of macrophages and HASMCs, and flow cytometry was used for the cell cycle analysis. 5-ethynyl-2′-deoxyuridine (EdU), cell counting kit-8 (CCK-8), and scratch assays were also performed to examine the proliferation and migration of HASMCs. Empagliflozin suppressed the progression of atherosclerotic lesions in ApoE−/− mice... (AU)


Subject(s)
Autophagy/drug effects , Atherosclerosis/drug therapy , Sodium-Glucose Transporter 2 Inhibitors
2.
J. physiol. biochem ; 80(1): 27-39, Feb. 2024. ilus, graf
Article in English | IBECS | ID: ibc-EMG-563

ABSTRACT

Cardiovascular disease due to atherosclerosis is one of the leading causes of death worldwide; however, the underlying mechanism has yet to be defined. The sodium-dependent glucose transporter 2 inhibitor (SGLT2i) empagliflozin is a new type of hypoglycemic drug. Recent studies have shown that empagliflozin not only reduces high glucose levels but also exerts cardiovascular-protective effects and slows the process of atherosclerosis. The purpose of this study was to elucidate the mechanism by which empagliflozin ameliorates atherosclerosis. Male apolipoprotein E-deficient (ApoE−/−) mice were fed a high-fat Western diet to establish an atherosclerosis model. The area and size of atherosclerotic lesions in ApoE−/− mice were then assessed by performing hematoxylin–eosin (HE) staining after empagliflozin treatment. Concurrently, oxidized low-density lipoprotein (oxLDL) was used to mimic atherosclerosis in three different types of cells. Then, following empagliflozin treatment of macrophage cells (RAW264.7), human aortic smooth muscle cells (HASMCs), and human umbilical vein endothelial cells (HUVECs), western blotting was applied to measure the levels of autophagy-related proteins and proinflammatory cytokines, and green fluorescent protein (GFP)-light chain 3 (LC3) puncta were detected using confocal microscopy to confirm autophagosome formation. Oil Red O staining was performed to detect the foaming of macrophages and HASMCs, and flow cytometry was used for the cell cycle analysis. 5-ethynyl-2′-deoxyuridine (EdU), cell counting kit-8 (CCK-8), and scratch assays were also performed to examine the proliferation and migration of HASMCs. Empagliflozin suppressed the progression of atherosclerotic lesions in ApoE−/− mice... (AU)


Subject(s)
Autophagy/drug effects , Atherosclerosis/drug therapy , Sodium-Glucose Transporter 2 Inhibitors
3.
J Physiol Biochem ; 80(1): 27-39, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37792168

ABSTRACT

Cardiovascular disease due to atherosclerosis is one of the leading causes of death worldwide; however, the underlying mechanism has yet to be defined. The sodium-dependent glucose transporter 2 inhibitor (SGLT2i) empagliflozin is a new type of hypoglycemic drug. Recent studies have shown that empagliflozin not only reduces high glucose levels but also exerts cardiovascular-protective effects and slows the process of atherosclerosis. The purpose of this study was to elucidate the mechanism by which empagliflozin ameliorates atherosclerosis. Male apolipoprotein E-deficient (ApoE-/-) mice were fed a high-fat Western diet to establish an atherosclerosis model. The area and size of atherosclerotic lesions in ApoE-/- mice were then assessed by performing hematoxylin-eosin (HE) staining after empagliflozin treatment. Concurrently, oxidized low-density lipoprotein (oxLDL) was used to mimic atherosclerosis in three different types of cells. Then, following empagliflozin treatment of macrophage cells (RAW264.7), human aortic smooth muscle cells (HASMCs), and human umbilical vein endothelial cells (HUVECs), western blotting was applied to measure the levels of autophagy-related proteins and proinflammatory cytokines, and green fluorescent protein (GFP)-light chain 3 (LC3) puncta were detected using confocal microscopy to confirm autophagosome formation. Oil Red O staining was performed to detect the foaming of macrophages and HASMCs, and flow cytometry was used for the cell cycle analysis. 5-ethynyl-2'-deoxyuridine (EdU), cell counting kit-8 (CCK-8), and scratch assays were also performed to examine the proliferation and migration of HASMCs. Empagliflozin suppressed the progression of atherosclerotic lesions in ApoE-/- mice. Empagliflozin also induced autophagy in RAW246.7 cells, HASMCs, and HUVECs via the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, and it significantly increased the levels of the Beclin1 protein, the LC3B-II/I ratio, and p-AMPK protein. In addition, empagliflozin decreased the expression of P62 and the protein levels of inflammatory cytokines, and it inhibited the foaming of RAW246.7 cells and HASMCs, as well as the expression of inflammatory factors by inducing autophagy. Empagliflozin activated autophagy through the AMPK signaling pathway to delay the progression of atherosclerosis. Furthermore, the results of flow cytometry, EdU assays, CCK-8 cell viability assays, and scratch assays indicated that empagliflozin blocked HASMCs proliferation and migration. Empagliflozin activates autophagy through the AMPK signaling pathway to delay the evolution of atherosclerosis, indicating that it may represent a new and effective drug for the clinical treatment of atherosclerosis.


Subject(s)
Atherosclerosis , Benzhydryl Compounds , Glucosides , Sodium-Glucose Transporter 2 Inhibitors , Male , Mice , Humans , Animals , Sodium-Glucose Transporter 2 Inhibitors/pharmacology , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , AMP-Activated Protein Kinases/metabolism , Atherosclerosis/metabolism , Autophagy , Human Umbilical Vein Endothelial Cells/metabolism , Cytokines/metabolism , Apolipoproteins E
4.
Phonetica ; 81(1): 81-117, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-37814341

ABSTRACT

Referents with a topical or focused status have been shown to be preferable antecedents in real-time resolution of pronouns. However, it remains unclear regarding whether topicality and focus compete for prominence when co-present in the same narrative, and if so, how differential prominence affects prosodic realization of a subsequent pronoun. Building upon the general understanding that stress on pronouns signals an unusual, less accessible interpretation, we take advantage of the conditional bi-clausal construction in conjunction with homophonic 3rd person pronouns in Chinese. We manipulated the information status of two referents that were introduced into a six-clause narrative in succession, specifically (i) Topic and (ii) Focus, and also (iii) the Reference of the Pronoun (either the first or second referent). Our acoustic analyses showed that pronouns were produced with higher F0s when the first referent was topicalized than when it was not topicalized under conditions where the second referent was focused. Pronouns referring back to the first referent were uttered longer when the referent was not topicalized than when it was topicalized. These results suggest accessibility statuses of referents vary dynamically in response to different prominence-lending cues, and these variations can be captured by the prosodic features of a following pronoun.


Subject(s)
Language , Narration
5.
Biochemistry (Mosc) ; 88(9): 1296-1303, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37770396

ABSTRACT

Store-operated calcium entry (SOCE) is the main mechanism for the Ca2+ influx in non-excitable cells. The two major components of SOCE are stromal interaction molecule 1 (STIM1) in the endoplasmic reticulum and Ca2+ release-activated Ca2+ channel (CRAC) Orai on the plasma membrane. SOCE requires interaction between STIM1 and Orai. Mammals have three Orai homologs: Orai1, Orai2, and Orai3. Although Orai1 has been widely studied and proven to essential for numerous cellular processes, Orai3 has also attracted a significant attention recently. The gating and activation mechanisms of Orai3 have yet to be fully elucidated. Here, we expressed, purified, and reconstituted Orai3 protein into liposomes and investigated its orientation and oligomeric state in the resulting proteoliposomes. STIM1 interacted with the Orai3-containing proteoliposomes and mediated calcium release from the them, suggesting that the Orai3 channel was functional and that recombinant STIM1 could directly open the Orai3 channel in vitro. The developed in vitro calcium release system could be used to study the structure, function, and pharmacology of Orai3 channel.


Subject(s)
Calcium Channels , Liposomes , Animals , Calcium Channels/metabolism , Calcium/metabolism , Membrane Proteins/metabolism , ORAI1 Protein/genetics , Mammals/metabolism
6.
Q J Exp Psychol (Hove) ; 76(9): 2139-2154, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36305667

ABSTRACT

Production research has yielded mixed findings regarding whether grammatical encoding specifies grammatical functions and linear word order simultaneously or separately, supporting either one-stage or two-stage models. Here, we focused on the double object (DO) and shifted double object (SDO) constructions in Zhuang, an ethnic minority language in China because they differ only in linear ordering of the two nouns whose grammatical functions are direct object and indirect object, assuming the roles of Theme and Recipient, respectively. Using two structural priming experiments, we found that both DO and SDO constructions induced within-structure priming effects, but they did not prime each other. Such structural priming effects persisted, regardless of whether semantic features (i.e., animacy of the Theme) were repeated across primes and targets. Taken together, these priming patterns support the one-stage model of grammatical encoding, where a conceptual representation is converted into a structure specifying both grammatical functions and linear word order.


Subject(s)
Ethnicity , Minority Groups , Humans , Language , Semantics , China
7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(6): 1146-1153, 2023 Nov 20.
Article in Chinese | MEDLINE | ID: mdl-38162062

ABSTRACT

Objective: To predict the intervention targets of empagliflozin (EMPA), a specific inhibitor of sodium-glucose cotransporter 2 (SGLT2), in gastric adenocarcinoma through comprehensive network pharmacology, and to validate the effects and the molecular mechanisms of EMPA through cellular and molecular biology experiments. Methods: Bioinformatics analysis of gastric adenocarcinoma was conducted to assess the correlation between gastric adenocarcinoma prognosis and SGLT2 expression. Network pharmacology was utilized to identify shared targets of EMPA and gastric adenocarcinoma. AGS cells, a human gastric adenocarcinoma cells line, were incubated with EMPA at different concentrations for 24 h and, then, cell proliferation was assessed using the CCK8 assay. After AGS cells were incubated with EMPA at the doses of 0, 3, and 6 mmol/L, real-time cell analysis (RTCA) and 5-ethynyl-2-deoxyuridine (EdU) incorporation were used to evaluate EMPA's inhibitory effects on the proliferation of the AGS cells. In addition, wound healing and Transwell assays were performed to assess the inhibitory effect of EMPA on the migration and invasion of the APC cells and Western blot analysis was conducted to examine the expression of mammalian target of rapamycin (mTOR) and phosphorylated mTOR (p-mTOR). BALB/c (nu/nu) nude mice were implanted with 5×106 AGS cells in the axilla. The mice were divided into three groups, a control group, a low-dose group, and a high-dose group, each consisting of 7 mice. After one week, the control group received daily intraperitoneal injections of normal saline, while the low-dose group and high-dose group received daily intraperitoneal injections of EMPA at the doses of 3 mg/kg and 5 mg/kg, respectively. The tumor volume was measured one week after the drug intervention started. Results: Gastric adenocarcinoma patients with low expression of SGLT2 exhibited longer survival time and higher survival rate than those with high expression of SGLT2 did. A total of 104 EMPA-related potential targets and 2028 targets associated with gastric adenocarcinoma were identified. Among these, 45 targets associated with gastric adenocarcinoma overlapped with potential targets of EMPA. Further analysis revealed 10 relevant pathways and 4 core genes. The core genes were cyclin-dependent kinase 4 (CDK4), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), mTOR, and cyclin E1 (CCNE1). CCK-8 assay revealed that EMPA at concentrations ranging from 0.39 to 50 mmol/L effectively inhibited the proliferation of AGS cells. RTCA results indicated a downward shift in the cell growth curve. In comparison to the findings for the control group, EdU assay demonstrated that EMPA at the concentrations of 3 mmol/L and 6 mmol/L significantly inhibited AGS cell proliferation (P<0.05). Results from wound healing and Transwell assays indicated a decrease in the levels of cell migration and invasion (P<0.05) and, notably, there was a significant difference between the high and low-dose EMPA groups (P<0.05). Western blot showed no statistically significant difference in the expression of total mTOR protein between the groups. However, the expression of p-mTOR in the 3 mmol/L and 6 mmol/L EMPA groups decreased compared to that of the control group (P<0.05), with the 6 mmol/L EMPA group exhibiting a more pronounced reduction (P<0.05). Nude mice xenograft tumor experiment demonstrated that, compared to that of the control group, the tumor volumes in the EMPA-treatment groups were significantly reduced (P<0.05), with the high-dose group showing a more pronounced reduction (P<0.05). Conclusion: EMPA inhibits the abnormal proliferation and migration of gastric adenocarcinoma cells, potentially through the modulation of mTOR protein activation. This study provides new potential medication and intervention targets for gastric adenocarcinoma treatment.


Subject(s)
Adenocarcinoma , Sodium-Glucose Transporter 2 Inhibitors , Stomach Neoplasms , TOR Serine-Threonine Kinases , Animals , Humans , Mice , Adenocarcinoma/drug therapy , Adenocarcinoma/pathology , Cell Line, Tumor , Cell Proliferation , Mice, Nude , Signal Transduction , Sirolimus/pharmacology , Sodium-Glucose Transporter 2/metabolism , Stomach Neoplasms/metabolism , TOR Serine-Threonine Kinases/metabolism , Sodium-Glucose Transporter 2 Inhibitors/pharmacology
8.
Oncogenesis ; 11(1): 55, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-36109490

ABSTRACT

As an important second messenger, calcium (Ca2+) regulates a wide variety of physiological processes. Disturbance of intracellular calcium homeostasis implicated in the occurrence of multiple types of diseases. Orai1 is the major player in mediating store-operated calcium entry (SOCE) and regulates calcium homeostasis in non-excitable cells. Over-expression and activation of Orai1 have been reported in breast cancer. However, its molecular mechanisms are still not very clear. Here, we demonstrated that Nucleolin (NCL) was a novel interacting partner of Orai1. NCL is a multifunctional nucleocytoplasmic protein and is upregulated in human breast tumors. The binding of C-termini of NCL (NCL-CT) to N-termini of Orai1 (Orai1-NT) is critical for mediating calcium influx and proliferation of breast cancer cells. Blocking the NCL-Orai1 interaction by synthesized Orai1 peptide can effectively reduce the intracellular calcium influx and suppress the proliferation of breast cancer cells in vitro and in vivo. Our findings reveal a novel activation mechanism of Orai1 via direct interaction with NCL, which may lead to calcium homeostasis imbalance and promote the proliferation of breast cancer cells. Blocking NCL-Orai1 interaction might be an effective treatment of breast cancer.

9.
Int J Cardiol ; 367: 56-62, 2022 11 15.
Article in English | MEDLINE | ID: mdl-35931206

ABSTRACT

OBJECTIVE: In recent years, some authoritative clinical studies have found that SGLT2 inhibitor can reduce cardiovascular risk in patients with diabetes, which may imply that SGLT2 inhibitor can play a role beyond lowering blood glucose. In this study, we explored the effect of empagliflozin on vascular atherosclerosis after removing the effect of diabetes. METHODS: The interaction between SGLT2 inhibitor and the AMPK(Adenosine 5'-monophosphate-activated protein kinase) signal pathway to attenuate atherosclerosis was studied in both spontaneously atherosclerotic mice in vivo and oxidized low-density lipoprotein(ox-LDL) induced macrophage inflammation model in vitro. In vivo experiment the aorta tree and aortic valve area were stained with oil red, and the level of inflammatory factors in the diseased tissue was evaluated by immunohistochemistry. Meanwhile, serum was collected to detect the levels of inflammatory factors. In vitro experiment, the RAW264.7 cell line was selected and ox-LDL was used to induce the release of proinflammatory factors, and different doses of empagliflozin were added. The phagocytosis of macrophages to ox-LDL density lipoprotein, and the expression of inflammatory factors at the protein and RNA levels were measured. RESULTS: Empagliflozin reduced the area of atherosclerotic plaque and macrophage infiltration in atherosclerotic plaques, decreased the expression of inflammatory factors in local plaque tissues and serum of APOE-/- mice fed with high-fat diet. Empagliflozin can improve the protein expression level of p-AMPK affected by ox-LDL in cell and reduce the gene expression level of inflammatory factors and protein expression level of NF-κB, thus playing an anti-atherosclerosis role. CONCLUSIONS: Empagliflozin improves energy metabolism and reduces the expression of inflammatory factors by activating AMPK. As empagliflozin inhibits atherosclerosis progression, it may be of use in prevention of cardiovascular diseases.


Subject(s)
Atherosclerosis , Plaque, Atherosclerotic , Sodium-Glucose Transporter 2 Inhibitors , AMP-Activated Protein Kinases/metabolism , Adenosine/pharmacology , Animals , Apolipoproteins E/genetics , Atherosclerosis/drug therapy , Atherosclerosis/genetics , Atherosclerosis/prevention & control , Benzhydryl Compounds , Blood Glucose/metabolism , Glucosides , Inflammation/metabolism , Lipoproteins, LDL/metabolism , Macrophages/metabolism , Mice , NF-kappa B/metabolism , Plaque, Atherosclerotic/metabolism , RNA , Signal Transduction , Sodium-Glucose Transporter 2 Inhibitors/metabolism , Sodium-Glucose Transporter 2 Inhibitors/pharmacology , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use
10.
Front Psychol ; 12: 794500, 2021.
Article in English | MEDLINE | ID: mdl-34925195

ABSTRACT

English as a verb-medial language has a short-before-long preference, whereas Korean and Japanese as verb-final languages show a long-before-short preference. In second language (L2) research, little is known regarding how L1 processing strategies affect the ultimate attainment of target structures. Existing work has shown that native speakers of Chinese strongly prefer to utter demonstrative-classifier (DCL) phrases first in subject-extracted relatives (DCL-SR-N) and DCLs second in object-extracted relatives (OR-DCL-N). But it remains unknown whether L2 learners with typologically different language backgrounds are able to acquire native-like strategies, and how they deviate from native speakers or even among themselves. Using a phrase-assembly task, we investigated advanced L2-Chinese learners whose L1s were English, Korean, and Japanese, because English lacks individual classifiers and has postnominal relative clause (RC), whereas Korean and Japanese have individual classifiers and prenominal RCs. Results showed that the English and Korean groups deviated from the native controls' asymmetric pattern, but the Japanese group approximated native-like performance. Furthermore, compared to the English group, the Korean and Japanese groups favored the DCL-second configuration in SRs and ORs. No differences were found between the Korean and Japanese groups. Overall, our findings suggest that L1 processing strategies play an overarching role in L2 acquisition of asymmetric positioning of DCLs in Chinese RCs.

11.
Mol Carcinog ; 60(12): 813-825, 2021 12.
Article in English | MEDLINE | ID: mdl-34499772

ABSTRACT

Cancer multidrug resistance (MDR) is existence in stem cell-like cancer cells characterized by stemness including high-proliferation and self-renewal. Programmed cell death 4 (PDCD4), as a proapoptotic gene, whether it engaged in cancer stemness and cisplatin resistance is still unknown. Here we showed that PDCD4 expressions in Hela/DDP (cisplatin resistance) cells were lower than in parental Hela cells. Moreover, the levels of drug resistance genes and typical stemness markers were markedly elevated in Hela/DDP cells. In vivo, xenograft tumor assay confirmed that knockdown of PDCD4 accelerated the grafted tumor growth. In vitro, colony formation and MTT assay demonstrated that PDCD4 overexpression inhibited cells proliferation in conditions with or without cisplatin. By contrast, PDCD4 deficiency provoked cell proliferation and cisplatin resistance. On mechanism, PDCD4 decreased the protein levels of pAKT and pYB1, accompanied by reduced MDR1 expression. Correspondingly, luciferase reporter assay showed PDCD4 regulated MDR1 promoter activity entirely relied on YB1. Furthermore, Ch-IP, GST-pulldown, and Co-IP assays provided novel evidence that PDCD4 could directly bind with YB1 by the nucleolar localization signal (NOLS) segment, causing the reduced YB1 binding into the MDR1 promoter region through blocking YB1 nucleus translocation, triggering the decreased MDR1 transcription. Taken together, PDCD4-pAKT-pYB1 forms the integrated molecular network to regulate MDR1 transcription during the process of stemness-associated cisplatin resistance.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Drug Resistance, Neoplasm , RNA-Binding Proteins/metabolism , Uterine Cervical Neoplasms/pathology , Y-Box-Binding Protein 1/metabolism , ATP Binding Cassette Transporter, Subfamily B/genetics , ATP Binding Cassette Transporter, Subfamily B/metabolism , Animals , Antineoplastic Agents/pharmacology , Apoptosis Regulatory Proteins/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Cisplatin/pharmacology , Down-Regulation , Female , Gene Expression Regulation, Neoplastic/drug effects , Gene Knockdown Techniques , HeLa Cells , Humans , Mice , Promoter Regions, Genetic , RNA-Binding Proteins/genetics , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/metabolism
12.
J Oncol ; 2021: 9992218, 2021.
Article in English | MEDLINE | ID: mdl-33976698

ABSTRACT

PURPOSE: Cervical cancer is the fourth most common cancer in women worldwide and is the main cause of cancer-related deaths in women. Cisplatin (DDP) is one of the major chemotherapeutic drugs for cervical cancer patients. But, drug resistance limits the effectiveness of cancer therapy. Nucleolin (NCL) is a nucleocytoplasmic multifunctional protein involved in the development of cancer. It has been reported that NCL may be a potential target for modulation of drug resistance. However, the precise molecular mechanisms are poorly understood. MATERIALS AND METHODS: Human cervical cancer Hela cells and their cisplatin-resistant cell line Hela/DDP were used in this study. The protein level of NCL in cervical cancer cells was measured by western blot analysis. Hela cells and Hela/DDP cells were transfected with NCL overexpression plasmid or NCL siRNA separately. MTT and EdU assay were performed to evaluate the cell viability and sensitivity to cisplatin. The drug efflux function of MDR1 protein was assessed by intracellular rhodamine-123 accumulation assay.The promoter activity of MDR1 was assessed by using a dual-luciferase reporter assay. RESULTS: We found that the protein level of NCL was elevated in Hela/DDP cells. Overexpression of NCL increased cervical cancer cell proliferation and attenuated the sensitivity to cisplatin. Overexpression of NCL increased Multidrug resistance (MDR1) gene expression and drug efflux. Our results demonstrated that NCL was highly related with cisplatin resistance in cervical cancer. NCL played an important role in MDR1 gene transcription through regulation of the transcription factor YB1. CONCLUSION: Our findings revealed the novel role of NCL in cisplatin-resistant cervical cancer and NCL may be a potential therapeutic target for chemoresistance.

13.
J Cell Sci ; 133(8)2020 04 29.
Article in English | MEDLINE | ID: mdl-32107289

ABSTRACT

Store-operated Ca2+ entry (SOCE) is critical for numerous Ca2+-related processes. The activation of SOCE requires engagement between stromal interaction molecule 1 (STIM1) molecules on the endoplasmic reticulum and Ca2+ release-activated channel (CRAC) Orai on the plasma membrane. However, the molecular details of their interactions remain elusive. Here, we analyzed STIM1-Orai interactions using synthetic peptides derived from the N- and C-termini of Orai channels (Orai-NT and Orai-CT, respectively) and purified fragments of STIM1. The binding of STIM1 to Orai-NT is hydrophilic based, whereas binding to the Orai-CT is mostly hydrophobic. STIM1 decreases its affinity for Orai-CT when Orai-NT is present, supporting a stepwise interaction. Orai3-CT exhibits stronger binding to STIM1 than Orai1-CT, largely due to the shortness of one helical turn. The role of newly identified residues was confirmed by co-immunoprecipitation and Ca2+ imaging using full-length molecules. Our results provide important insight into CRAC gating by STIM1.


Subject(s)
Calcium Channels , Calcium , Calcium/metabolism , Calcium Channels/genetics , Calcium Channels/metabolism , Calcium Signaling , Endoplasmic Reticulum/genetics , Endoplasmic Reticulum/metabolism , ORAI1 Protein/genetics , ORAI1 Protein/metabolism , Stromal Interaction Molecule 1/genetics , Stromal Interaction Molecule 1/metabolism
14.
Biochem Biophys Res Commun ; 516(4): 1066-1072, 2019 09 03.
Article in English | MEDLINE | ID: mdl-31279526

ABSTRACT

Intracellular Ca2+ signals play many important cellular functions such as migration, proliferation and differentiation. Store-operated Ca2+ entry (SOCE) is a major route of Ca2+ entry in nonexcitable cells. The activation of SOCE requires engagement between stromal interaction molecule 1 (STIM1) molecules on the endoplasmic reticulum and Ca2+ release-activated Ca2+ (CRAC) channel Orais (Orai1-3) on the plasma membrane. Accumulating evidence indicates that SOCE plays critical roles in cancer cell proliferation, invasion and metastasis. Here, we used the synthetic intracellular peptides derived from the C-termini of Orai channels to treat the breast cancer cells. We have found that Orai3-CT peptide exhibits stronger binding to STIM1 than Orai1-CT, and Orai3-CT peptide acts in a dominant negative fashion, blocking the STIM1-Orai1 interaction and reducing the Ca2+ entry and proliferation of breast cancer cells.


Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Calcium Release Activated Calcium Channels/pharmacology , Cell Proliferation/drug effects , Peptides/pharmacology , Antineoplastic Agents/chemistry , Breast Neoplasms/metabolism , Calcium/metabolism , Calcium Channels/chemistry , Calcium Channels/pharmacology , Calcium Release Activated Calcium Channels/chemistry , Calcium Signaling/drug effects , Female , Humans , MCF-7 Cells , Neoplasm Proteins/metabolism , ORAI1 Protein/chemistry , ORAI1 Protein/pharmacology , Peptides/chemistry , Protein Interaction Maps/drug effects , Stromal Interaction Molecule 1/metabolism
15.
J Cell Biochem ; 120(5): 7689-7700, 2019 May.
Article in English | MEDLINE | ID: mdl-30426537

ABSTRACT

BACKGROUND: Advanced glycation end-product is a modified form of low-density lipoprotein (AGE-LDL) and accelerates atherosclerosis through undefined mechanisms. Programmed cell death protein 4 (PDCD4), a transcriptional regulator, plays an important role in the regulation of autophagy. The aim of the present study was to investigate the role of PDCD4 involved in AGE-LDL-induced foam cell formation. METHODS: The characterization of AGE-LDL was measured by the thiobarbituric assay and agarose gel electrophoresis in vitro. RAW264.7, THP-1 cell line and primary peritoneal macrophages of mice were transfected with shPDCD4 plasmid AGE-LDL-induced foam cell formation was stained by Oil Red, and the levels of autophagy and apoptosis were determined by Western blot analysis. Autophagosome was observed with immunofluorescence microscopy. Mitochondrial membrane potential and autophagic flux were assessed by flow cytometry. RESULTS: AGE modification resulted in significant reduction of absorbance shown by thiobarbituric assay and augmentation of electrophoresis mobility. Further studies suggest that macrophages exposed AGE-LDL triggered autophagy in the early stage of foam cell formation. PDCD4 deficiency enhanced lipoautophagy but inhibited apoptosis and mitochondria dysfunction. Previous studies have been reported that autophagy is an adaptive response might prevent lesional macrophage apoptosis. In our study, we found PDCD4 deficiency attenuated apoptosis and AGE-LDL-induced foam cell formation relied on increased autophagy. CONCLUSION: Our data revealed that PDCD4 deficiency can facilitate autophagy and benefit for AGE-LDL-induced foam cell formation.

16.
Cogn Sci ; 42 Suppl 4: 1101-1133, 2018 06.
Article in English | MEDLINE | ID: mdl-29023849

ABSTRACT

We used Chinese prenominal relative clauses (RCs) to test the predictions of two competing accounts of sentence comprehension difficulty: the experience-based account of Levy () and the Dependency Locality Theory (DLT; Gibson, ). Given that in Chinese RCs, a classifier and/or a passive marker BEI can be added to the sentence-initial position, we manipulated the presence/absence of classifiers and the presence/absence of BEI, such that BEI sentences were passivized subject-extracted RCs, and no-BEI sentences were standard object-extracted RCs. We conducted two self-paced reading experiments, using the same critical stimuli but somewhat different filler items. Reading time patterns from both experiments showed facilitative effects of BEI within and beyond RC regions, and delayed facilitative effects of classifiers, suggesting that cues that occur before a clear signal of an upcoming RC can help Chinese comprehenders to anticipate RC structures. The data patterns are not predicted by the DLT, but they are consistent with the predictions of experience-based theories.


Subject(s)
Language , Psychological Theory , Comprehension , Cues , Humans , Psycholinguistics , Reading
17.
Oncotarget ; 8(1): 329-344, 2017 Jan 03.
Article in English | MEDLINE | ID: mdl-27861147

ABSTRACT

Triple-negative breast cancers (TNBCs) are the most aggressive and hard-to-treat breast tumors with poor prognosis, and exploration for novel therapeutic drugs is impending. Arctigenin (Atn), a bioactive lignan isolated from seeds of Arctium lappa L, has been reported to inhibit many cancer types; however, the effect of Atn on TNBC remains unclear. In this study, we demonstrated that Atn decreased proliferation, and induced apoptosis in TNBC cells. Furthermore, we explored the underlying mechanism of Atn inhibition on TNBC cells. Computational docking and affinity assay showed that Atn bound to the SH2 domain of STAT3. Atn inhibited STAT3 binding to genomic DNA by disrupting hydrogen bond linking between DNA and STAT3. In addition, Atn augmented Taxotere®-induced TNBC cell cytotoxicity. TNBC xenograft tests also confirmed the antitumor effect of Atn in vivo. These characteristics render Atn as a promising candidate drug for further development and for designing new effective STAT3 inhibitors.


Subject(s)
Antineoplastic Agents/pharmacology , Arctium/chemistry , Furans/pharmacology , Lignans/pharmacology , STAT3 Transcription Factor/antagonists & inhibitors , Taxoids/pharmacology , Triple Negative Breast Neoplasms/drug therapy , Animals , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , DNA/metabolism , Docetaxel , Drug Evaluation, Preclinical , Drug Synergism , Asia, Eastern , Female , Fluorescent Antibody Technique , Furans/therapeutic use , Humans , Hydrogen Bonding/drug effects , Lignans/therapeutic use , Mice, Nude , Molecular Docking Simulation , Plants, Medicinal/chemistry , Protein Domains , STAT3 Transcription Factor/metabolism , Signal Transduction/drug effects , Triple Negative Breast Neoplasms/pathology , Xenograft Model Antitumor Assays
18.
PLoS One ; 10(6): e0131936, 2015.
Article in English | MEDLINE | ID: mdl-26125621

ABSTRACT

The syntax-first model and the parallel/interactive models make different predictions regarding whether syntactic category processing has a temporal and functional primacy over semantic processing. To further resolve this issue, an event-related potential experiment was conducted on 24 Chinese speakers reading Chinese passive sentences with the passive marker BEI (NP1 + BEI + NP2 + Verb). This construction was selected because it is the most-commonly used Chinese passive and very much resembles German passives, upon which the syntax-first hypothesis was primarily based. We manipulated semantic consistency (consistent vs. inconsistent) and syntactic category (noun vs. verb) of the critical verb, yielding four conditions: CORRECT (correct sentences), SEMANTIC (semantic anomaly), SYNTACTIC (syntactic category anomaly), and COMBINED (combined anomalies). Results showed both N400 and P600 effects for sentences with semantic anomaly, with syntactic category anomaly, or with combined anomalies. Converging with recent findings of Chinese ERP studies on various constructions, our study provides further evidence that syntactic category processing does not precede semantic processing in reading Chinese.


Subject(s)
Brain Waves/physiology , Evoked Potentials/physiology , Semantics , Speech , Adult , Asian People , China , Comprehension , Electroencephalography , Female , Humans , Male , Young Adult
20.
Protein Cell ; 6(2): 139-46, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25407413

ABSTRACT

Formation of the endoplasmic reticulum (ER) network requires homotypic membrane fusion, which involves a class of atlastin (ATL) GTPases. Purified Drosophila ATL is capable of mediating vesicle fusion in vitro, but such activity has not been reported for any other ATLs. Here, we determined the preliminary crystal structure of the cytosolic segment of Drosophila ATL in a GDP-bound state. The structure reveals a GTPase domain dimer with the subsequent three-helix bundles associating with their own GTPase domains and pointing in opposite directions. This conformation is similar to that of human ATL1, to which GDP and high concentrations of inorganic phosphate, but not GDP only, were included. Drosophila ATL restored ER morphology defects in mammalian cells lacking ATLs, and measurements of nucleotide-dependent dimerization and GTPase activity were comparable for Drosophila ATL and human ATL1. However, purified and reconstituted human ATL1 exhibited no in vitro fusion activity. When the cytosolic segment of human ATL1 was connected to the transmembrane (TM) region and C-terminal tail (CT) of Drosophila ATL, the chimera still exhibited no fusion activity, though its GTPase activity was normal. These results suggest that GDP-bound ATLs may adopt multiple conformations and the in vitro fusion activity of ATL cannot be achieved by a simple collection of functional domains.


Subject(s)
Drosophila Proteins/chemistry , GTP Phosphohydrolases/chemistry , GTP-Binding Proteins/chemistry , Membrane Proteins/chemistry , Protein Conformation , Animals , Dimerization , Drosophila , Drosophila Proteins/genetics , Endoplasmic Reticulum/chemistry , GTP Phosphohydrolases/genetics , GTP-Binding Proteins/genetics , Guanosine Diphosphate/chemistry , Guanosine Diphosphate/metabolism , Humans , Membrane Proteins/genetics , Mutation , Protein Structure, Secondary
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