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1.
J Cancer Res Clin Oncol ; 148(7): 1803-1811, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34432128

ABSTRACT

PURPOSE: Programmed death-ligand 1 (PD-L1) expression may influence the prognosis of patients with localized esophageal cancer. The current study compared the prognostic value of PD-L1 expression between tumor cells and immune cells. METHODS: Archival esophageal tumor tissue samples were collected from patients who received paclitaxel and cisplatin-based neoadjuvant chemoradiotherapy (CRT) for locally advanced esophageal squamous cell carcinoma (ESCC) in three prospective phase II trials. PD-L1 expression on tumor and immune cells was examined immunohistochemically by using the SP142 antibody and scored by two independent pathologists. The association of PD-L1 expression with patient's outcomes was analyzed using a log-rank test and Cox regression multivariate analysis. RESULTS: A total of 100 patients were included. PD-L1 expression on tumor cells was positive (≥ 1%, TC-positive) in 55 patients; PD-L1 expression on immune cells was high (≥ 5%, IC-high) in 30 patients. TC-positive status was associated with poor overall survival (OS) (HR: 1.63, P = 0.035), whereas IC-high status was associated with improved OS (HR: 0.44, P = 0.0024). Multivariate analysis revealed that TC-positive, IC-high, and performance status were independent prognostic factors for progression-free survival and that IC-high and performance status were independent factors for OS. Furthermore, the combination of IC-high and TC-negative status was associated with the optimal OS, whereas that of TC-positive and IC-low status was associated with the worst OS. CONCLUSION: PD-L1 expression on tumor and immune cells may have different prognostic value for patients with locally advanced ESCC receiving neoadjuvant CRT. A combination of these two indexes may further improve the prognostic prediction.


Subject(s)
Esophageal Neoplasms , Esophageal Squamous Cell Carcinoma , B7-H1 Antigen/metabolism , Chemoradiotherapy , Esophageal Neoplasms/pathology , Esophageal Squamous Cell Carcinoma/therapy , Humans , Neoadjuvant Therapy , Prognosis , Prospective Studies
2.
Hum Pathol ; 107: 69-79, 2021 01.
Article in English | MEDLINE | ID: mdl-33186588

ABSTRACT

The mechanism of high-grade transformation in gastrointestinal stromal tumors (GISTs) remains to be clarified. We aim to discover the key progression events by studying biphasic GISTs. The study group included 101 GISTs. Nineteen of these had been screened from 263 GISTs to represent the early stage of GIST high-grade transformation, characterized by juxtaposed low-grade and high-grade regions in the same tumor (so-called biphasic GISTs). Mutational analyses, fluorescence in situ hybridization (FISH), NanoString analyses, telomere analysis, and gene expression profiling were carried out, followed by in silico analyses, cell line study, and immunohistochemical validation. Using gene expression analysis, downregulation of SFRP1 was revealed to be the main event in GIST high-grade transformation (p = 0.013), accompanied by upregulation of EZH2. In silico analyses revealed that downregulation of SFRP1 was a common feature in GIST progression across several different series. Immunohistochemically, the expression of SFRP1 was validated to be significantly lower in high-grade GISTs (WHO risk group 3a or higher) than in low-grade GISTs (p < 0.001), and attenuation/loss of SFRP1 was associated with GIST tumor progression (p < 0.001). By NanoString and FISH analyses, chromosomal 9/9p loss was the only recurrent large-scale chromosome aberration in biphasic GISTs, with a correlation with SFRP1 downregulation. Subclones containing chromosome 9/9p loss could be appreciated in the low-grade parts of biphasic GISTs. TP53 mutation, RB1 loss, KIT/PDGFRA mutation, and alternative lengthening of telomeres did not play a significant role in GIST high-grade transformation. In conclusion, high-grade transformation of GISTs features SFRP1 downregulation and chromosome 9/9p loss.


Subject(s)
Gastrointestinal Stromal Tumors/pathology , Intercellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/metabolism , Biomarkers, Tumor/metabolism , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Chromosomes, Human, Pair 9/genetics , Disease Progression , Enhancer of Zeste Homolog 2 Protein/metabolism , Gastrointestinal Stromal Tumors/genetics , Gastrointestinal Stromal Tumors/metabolism , Humans
3.
Eur J Obstet Gynecol Reprod Biol ; 229: 94-97, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30144728

ABSTRACT

OBJECTIVE: To identify factors predicting cervical elongation in women with uterine prolapse. STUDY DESIGN: The medical records of women with uterine prolapse who underwent vaginal hysterectomy were reviewed. Multivariable logistic regression analysis was performed to identify predictors of cervical elongation. RESULTS: Of 295 women with uterine prolapse, 136 (46.1%) patients had cervical elongation, according to Berger et al. Classification (i.e., cervical length >3.38 cm and/or cervix-to-corpus lengths ratio >0.79). Multivariable analysis revealed that lower parity (odds ratio = 0.85, 95% confidence interval [CI] = 0.73 to 0.99, P = 0.04) and advanced stage of uterine prolapse (odds ratio = 1.97, 95% CI = 1.35-2.88, P < 0.001) were predictors for cervical elongation. Based on a receiver operating characteristic curve (ROC) analysis, the following optimum cut-off values were determined for cervical elongation: (1) parity ≤3, ROC area = 0.60 (95% CI = 0.53 to 0.66); (2) stage of uterine prolapse ≥3, ROC area = 0.63 (95% CI = 0.56 to 0.69). Thus, the predicted logit(p) for a given parity (a) and stage of uterine prolapse (b) can be denoted by logit(p) = -1.26 - 0.16 x a + 0.68 x b. The optimum cut-off values of logit(p) ≥-0.18 to predict cervical elongation were determined using ROC analysis (area = 0.66, 95% CI = 0.59 to 0.73). For women with parity ≤6, we can use either (1) stage 2 uterine prolapse and parity ≤1, or (2) ≥ stage 3 uterine prolapse as criteria to predict cervical elongation. CONCLUSIONS: Lower parity and advanced stage of uterine prolapse are predictors of cervical elongation in women with uterine prolapse. Thus, stage of uterine prolapse ≥3 or logit(p) ≥-0.18 may be useful for predicting cervical elongation.


Subject(s)
Cervix Uteri/pathology , Uterine Prolapse/pathology , Aged , Female , Humans , Middle Aged , Parity , Risk Factors , Uterine Prolapse/complications
4.
Transl Res ; 197: 12-31, 2018 07.
Article in English | MEDLINE | ID: mdl-29653075

ABSTRACT

Inflammation, oxidative stress, and formation of advanced glycated end products (AGEs) and advanced lipoxidation end products (ALEs) are important for atherosclerosis. Vascular adhesion protein-1 (VAP-1) participates in inflammation and has semicarbazide-sensitive amine oxidase (SSAO) activity, which catalyzes oxidative deamination to produce hydrogen peroxide and aldehydes, leading to generation of AGEs and ALEs. However, the effect of VAP-1/SSAO inhibition on atherosclerosis remains controversial, and no studies used coronary angiography to evaluate if plasma VAP-1/SSAO is a biomarker for coronary artery disease (CAD). Here, we examined if plasma VAP-1/SSAO is a biomarker for CAD diagnosed by coronary angiography in humans and investigated the effect of VAP-1/SSAO inhibition by a specific inhibitor PXS-4728A on atherosclerosis in cell and animal models. In the study, VAP-1/SSAO expression was increased in plaques in humans and in apolipoprotein E (ApoE)-deficient mice, and colocalized with vascular endothelial cells and smooth muscle cells (SMCs). Patients with CAD had higher plasma VAP-1/SSAO than those without CAD. Plasma VAP-1/SSAO was positively associated with the extent of CAD. In ApoE-deficient mice, VAP-1/SSAO inhibition reduced atheroma and decreased oxidative stress. VAP-1/SSAO inhibition attenuated the expression of adhesion molecules, chemoattractant proteins, and proinflammatory cytokines in the aorta, and suppressed monocyte adhesion and transmigration across human umbilical vein endothelial cells. Consequently, the expression of markers for macrophage recruitment and activation in plaques was decreased by VAP-1/SSAO inhibition. Besides, VAP-1/SSAO inhibition suppressed proliferation and migration of A7r5 SMC. Our data suggest that plasma VAP-1/SSAO is a novel biomarker for the presence and the extent of CAD in humans. VAP-1/SSAO inhibition by PXS-4728A is a potential treatment for atherosclerosis.


Subject(s)
Amine Oxidase (Copper-Containing)/antagonists & inhibitors , Apolipoproteins E/deficiency , Atherosclerosis/drug therapy , Atherosclerosis/enzymology , Enzyme Inhibitors/therapeutic use , Semicarbazides/pharmacology , Allylamine/analogs & derivatives , Allylamine/pharmacology , Allylamine/therapeutic use , Animals , Atherosclerosis/blood , Benzamides/pharmacology , Benzamides/therapeutic use , Biomarkers/metabolism , Cell Adhesion Molecules/metabolism , Cell Movement/drug effects , Cell Proliferation/drug effects , Cholesterol , Cytokines/metabolism , Enzyme Inhibitors/pharmacology , Female , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Hydrogen Peroxide/metabolism , Inflammation Mediators/metabolism , Macrophages/metabolism , Male , Mice, Inbred C57BL , Middle Aged , Oxidative Stress/drug effects , Plaque, Atherosclerotic/drug therapy , Plaque, Atherosclerotic/pathology
5.
J Cereb Blood Flow Metab ; 37(2): 435-443, 2017 Feb.
Article in English | MEDLINE | ID: mdl-26823474

ABSTRACT

We aim to determine the cerebrospinal fluid levels of high mobility group box 1 in subarachnoid hemorrhage patients and to investigate the involvement of the receptor for advanced glycation end products and high mobility group box 1 in the pathogenesis of post-subarachnoid hemorrhage neuronal death. The study included 40 patients (mean age, 59 ± 19 years) with Fisher's grade ≥ III aneurysmal subarachnoid hemorrhage. Cerebrospinal fluid was collected on the seventh day post-hemorrhage. Receptor for advanced glycation end products expression was examined in rat brain tissue following subarachnoid hemorrhage and in cultured neurons exposed to post-subarachnoid hemorrhage cerebrospinal fluid. Therapeutic effects of the recombinant soluble form of RAGE on subarachnoid hemorrhage models were also investigated. The results indicated that a higher level of cerebrospinal fluid high mobility group box 1 was independently associated with unfavorable outcome at three months post-subarachnoid hemorrhage (OR = 1.061, 95% CI: 1.005-1.121). Expression of RAGE increased in post-subarachnoid hemorrhage rat brain cells and in cultured neuron with stimulation of post-subarachnoid hemorrhage cerebrospinal fluid. Administration of recombinant soluble form of RAGE significantly reduced the number of positive TUNEL staining cells in subarachnoid hemorrhage rat and improved cell viability in post-subarachnoid hemorrhage cerebrospinal fluid-treated cultured neurons. Thus, the level of cerebrospinal fluid high mobility group box 1 can be a prognostic indicator for patients with Fisher's grade ≥ III aneurysmal subarachnoid hemorrhage and that treatment with soluble form of RAGE is a novel approach for subarachnoid hemorrhage.


Subject(s)
Brain/pathology , HMGB1 Protein/cerebrospinal fluid , Neurons/pathology , Subarachnoid Hemorrhage/cerebrospinal fluid , Subarachnoid Hemorrhage/pathology , Adult , Aged , Animals , Brain/drug effects , Brain/metabolism , Cell Death , Cells, Cultured , Female , Glycation End Products, Advanced/metabolism , HMGB1 Protein/metabolism , Humans , Male , Middle Aged , Neurons/drug effects , Neurons/metabolism , Prognosis , Rats, Wistar , Receptor for Advanced Glycation End Products/metabolism , Receptor for Advanced Glycation End Products/therapeutic use , Recombinant Proteins/metabolism , Recombinant Proteins/therapeutic use , Subarachnoid Hemorrhage/drug therapy , Subarachnoid Hemorrhage/metabolism
6.
J Cereb Blood Flow Metab ; 37(6): 2098-2111, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27492949

ABSTRACT

The C-type lectin Mincle is implicated in innate immune responses to sterile inflammation, but its contribution to associated pathologies is not well understood. Herein, we show that Mincle exacerbates neuronal loss following ischemic but not traumatic spinal cord injury. Loss of Mincle was beneficial in a model of transient middle cerebral artery occlusion but did not alter outcomes following heart or gut ischemia. High functional scores in Mincle KO animals using the focal cerebral ischemia model were accompanied by reduced lesion size, fewer infiltrating leukocytes and less neutrophil-derived cytokine production than isogenic controls. Bone marrow chimera experiments revealed that the presence of Mincle in the central nervous system, rather than recruited immune cells, was the critical regulator of a poor outcome following transient middle cerebral artery occlusion. There was no evidence for a direct role for Mincle in microglia or neural activation, but expression in a subset of macrophages resident in the perivascular niche provided new clues on Mincle's role in ischemic stroke.


Subject(s)
Hypoxia-Ischemia, Brain/metabolism , Lectins, C-Type/metabolism , Membrane Proteins/metabolism , Reperfusion Injury/metabolism , Spinal Cord Injuries/metabolism , Animals , Disease Models, Animal , Flow Cytometry , Hypoxia-Ischemia, Brain/pathology , Hypoxia-Ischemia, Brain/physiopathology , In Situ Nick-End Labeling , Intestines/blood supply , Lectins, C-Type/genetics , Male , Membrane Proteins/genetics , Mice, Inbred C57BL , Mice, Knockout , Motor Activity/physiology , Myocardial Infarction/metabolism , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Reperfusion Injury/pathology , Reperfusion Injury/physiopathology , Spinal Cord Injuries/pathology , Spinal Cord Injuries/physiopathology
7.
Ann Neurol ; 77(3): 504-16, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25558977

ABSTRACT

OBJECTIVE: Stroke is a leading cause of mortality and disability. The peptidyl-prolyl cis/trans isomerase Pin1 regulates factors involved in cell growth. Recent evidence has shown that Pin1 plays a major role in apoptosis. However, the role of Pin1 in ischemic stroke remains to be investigated. METHODS: We used Pin1 overexpression and knockdown to manipulate Pin1 expression and explore the effects of Pin1 in cell death on ischemic stress in vitro and in a mouse stroke model. We also used Pin 1 inhibitor, γ-secretase inhibitor, Notch1 intracellular domain (NICD1)-deleted mutant cells, and Pin1 mutant cells to investigate the underlying mechanisms of Pin1-NICD1-mediated cell death. RESULTS: Our findings indicate that Pin1 facilitates NICD1 stability and its proapoptotic function following ischemic stroke. Thus, overexpression of Pin1 increased NICD1 levels and enhanced its potentiation of neuronal death in simulated ischemia. By contrast, depletion or knockout of Pin1 reduced the NICD1 level, which in turn desensitized neurons to ischemic conditions. Pin1 interacted with NICD1 and increased its stability by inhibiting FBW7-induced polyubiquitination. We also demonstrate that Pin1 and NICD1 levels increase following stroke. Pin1 heterozygous (+/-) and knockout (-/-) mice, and also wild-type mice treated with an inhibitor of Pin1, each showed reduced brain damage and improved functional outcomes in a model of focal ischemic stroke. INTERPRETATION: These results suggest that Pin1 contributes to the pathogenesis of ischemic stroke by promoting Notch signaling, and that inhibition of Pin1 is a novel approach for treating ischemic stroke.


Subject(s)
Apoptosis/physiology , Ischemia/metabolism , Neurons/metabolism , Peptidylprolyl Isomerase/metabolism , Receptor, Notch1/metabolism , Stroke/metabolism , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid Precursor Protein Secretases/metabolism , Animals , Cells, Cultured , Cerebral Cortex/cytology , Cerebral Cortex/pathology , Disease Models, Animal , Humans , Ischemia/drug therapy , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Peptidylprolyl Isomerase/antagonists & inhibitors , Peptidylprolyl Isomerase/genetics , Protein Stability , Protein Structure, Tertiary/physiology , Signal Transduction/physiology , Stroke/drug therapy
8.
Clin Chim Acta ; 428: 51-6, 2014 Jan 20.
Article in English | MEDLINE | ID: mdl-24211727

ABSTRACT

BACKGROUND: Vascular adhesion protein-1 (VAP-1) participates in inflammation and catalyzes the breakdown of amines to produce aldehyde, hydrogen peroxide, and ammonia. Serum VAP-1 can predict cancer mortality, including colorectal cancer (CRC) mortality, in type 2 diabetic subjects. However, it remains unknown if serum VAP-1 can predict mortality in CRC patients. This prospective cohort study investigates if serum VAP-1 is a novel biomarker for mortality prediction in CRC. METHODS: We enrolled 300 CRC patients. Preoperative serum VAP-1 was measured by time-resolved immunofluorometric assay. They were followed until September 2009 or death, which was ascertained by the National Death Registration System. RESULTS: The median follow-up period was 4.7 years. Compared with normal counterpart, VAP-1 immunoactivity was upregulated in CRC tissues, especially at the invasion front. Serum VAP-1 can independently predict all-cause mortality (HR: 1.0026, 95% CI: 1.0003-1.0050, P<0.05) and cancer-related mortality (HR: 1.0026, 95% CI: 1.0001-1.0050, P<0.05). A risk score composed of age, gender, carcinoembryonic antigen (CEA) >5 ng/ml, tumor grading, tumor staging, and serum VAP-1 could stratify CRC patients into low-, intermediate-, and high-risk subgroups, with a 5-year mortality rate of 10%, 34%, and 78%, respectively. CONCLUSIONS: Serum VAP-1 predicts mortality independently and improves risk stratification in CRC subjects.


Subject(s)
Amine Oxidase (Copper-Containing)/blood , Cause of Death , Cell Adhesion Molecules/blood , Colorectal Neoplasms/blood , Colorectal Neoplasms/mortality , Aged , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Survival Analysis
9.
Exp Neurol ; 250: 341-7, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24196452

ABSTRACT

Toll-like receptors (TLRs) are transmembrane pattern-recognition receptors that initiate signals in response to diverse pathogen-associated molecular patterns. Several groups have recently reported a role for TLR2 and TLR4 in ischemic stroke-induced brain injury. However, relatively little is known about the role of TLR8 in ischemic stroke. Here we provide the first evidence that TLR8 activation plays a detrimental role in stroke outcome by promoting neuronal apoptosis and T cell-mediated post-stroke inflammation. TLR8 is expressed in cerebral cortical neurons, where its levels and downstream signaling via JNK are increased in response to oxygen glucose deprivation (OGD). Treatment with a TLR8 agonist activated pro-apoptotic JNK and increased neuronal cell death during OGD. Furthermore, selective knockdown of TLR8 using siRNA protected SH-SY5Y cells following OGD, and TLR8 agonist administration in vivo increased mortality, neurological deficit and T cell infiltration following stroke. Taken together, our findings indicate a detrimental role for neuronal TLR8 signaling in the triggering of post-stroke inflammation and neuronal death.


Subject(s)
Apoptosis/physiology , Signal Transduction/physiology , Stroke/metabolism , Toll-Like Receptor 8/metabolism , Animals , Blotting, Western , Cell Line , Disease Models, Animal , Flow Cytometry , Humans , Immunohistochemistry , Inflammation/immunology , Inflammation/metabolism , Male , Mice , Mice, Inbred C57BL , Reverse Transcriptase Polymerase Chain Reaction , Stroke/immunology , Toll-Like Receptor 8/immunology
10.
Arterioscler Thromb Vasc Biol ; 33(3): 585-94, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23288172

ABSTRACT

OBJECTIVE: Little is known about the involvement of the soluble form of receptor for advanced glycation end products (sRAGE) in acute ischemic stroke (IS). Here, we aim to identify the role of plasma sRAGE and high mobility group box 1 (HMGB1) in imaging-confirmed IS patients, as well as mice subjected to focal ischemic stroke. METHODS AND RESULTS: IS patients were recruited and plasma samples were collected for the measurement of sRAGE and HMGB1 after stroke. The relation of sRAGE and HMGB1 with acute IS was also investigated in a C57BL/6J mouse model of focal ischemic stroke and primary cortical neurons subjected to oxygen and glucose deprivation. Plasma levels of sRAGE and HMGB1 were both significantly increased within 48 hours after IS, and the sRAGE level was an independent predictor of functional outcome at 3 months poststroke. Immunoprecipitation assays revealed that the binding of plasma HMGB1 to sRAGE increased progressively after IS both in patients and mice. Administration of recombinant sRAGE significantly reduced infiltrating immune cells and improved the outcome of injury in mice, protected cultured neurons against oxygen and glucose deprivation-induced cell death, and ameliorated the detrimental effect of recombinant HMGB1. CONCLUSIONS: Early poststroke plasma sRAGE may play a protective role in IS by capturing HMGB1. Hence, recombinant sRAGE is a potential therapeutic agent in acute IS.


Subject(s)
Cerebral Cortex/metabolism , Infarction, Middle Cerebral Artery/blood , Neurons/metabolism , Receptors, Immunologic/blood , Stroke/blood , Adult , Aged , Aged, 80 and over , Analysis of Variance , Animals , Biomarkers/blood , Case-Control Studies , Cell Death , Cell Hypoxia , Cells, Cultured , Cerebral Cortex/drug effects , Cerebral Cortex/pathology , Chi-Square Distribution , Disease Models, Animal , Female , Glucose/deficiency , HMGB1 Protein/blood , Humans , Immunoprecipitation , Infarction, Middle Cerebral Artery/diagnosis , Infarction, Middle Cerebral Artery/drug therapy , Logistic Models , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Neurons/drug effects , Neurons/pathology , Neuroprotective Agents/administration & dosage , Oxygen/metabolism , Prognosis , Protein Binding , Rats , Rats, Sprague-Dawley , Receptor for Advanced Glycation End Products , Receptors, Immunologic/administration & dosage , Receptors, Immunologic/deficiency , Receptors, Immunologic/genetics , Risk Factors , Stroke/diagnosis , Stroke Rehabilitation , Taiwan , Time Factors , Up-Regulation
11.
Brain Pathol ; 23(4): 402-12, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23211047

ABSTRACT

Calsenilin is a calcium sensor protein that interacts with presenilin and increases calcium-triggered neuronal apoptosis, and γ-secretase activity. Notch is a cell surface receptor that regulates cell-fate decisions and synaptic plasticity in brain. The aim of the present study was to characterize the role of calsenilin as a regulator of the γ-secretase cleavage of Notch in ischemic stroke. Here, we determined the modulation of expression level and cellular distribution of calsenilin in neurons subjected to ischemic-like conditions. The levels of calsenilin and presenilin were increased in primary neurons after oxygen and glucose deprivation. Furthermore, calsenilin was found to enhance the γ-secretase cleavage of Notch and to contribute to cell death under ischemia-like conditions. The inhibition of γ-secretase activity and a presenilin deficiency were both found to protect against calsenilin-mediated ischemic neuronal death. The expression of calsenilin was found to be increased in brain following experimental ischemic stroke. These findings establish a specific molecular mechanism by which the induction of calsenilin enhances Notch activation in ischemic stroke, and identify calsenilin as an upstream of the γ-secretase cleavage of Notch.


Subject(s)
Apoptosis/physiology , Brain Ischemia/pathology , Infarction, Middle Cerebral Artery/pathology , Kv Channel-Interacting Proteins/metabolism , Neurons/metabolism , Animals , Animals, Newborn , Brain/cytology , Cells, Cultured , Disease Models, Animal , Embryo, Mammalian , Glucose/deficiency , Hypoxia/pathology , Male , Mice , Mice, Inbred C57BL , Neurons/pathology , Presenilins/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction/physiology , Time Factors , Up-Regulation/physiology
12.
Exp Transl Stroke Med ; 2(1): 15, 2010 Aug 11.
Article in English | MEDLINE | ID: mdl-20701790

ABSTRACT

BACKGROUND: Adiponectin is a hormone produced in and released from adipose cells, which has been shown to have anti-diabetic and anti-inflammatory actions in peripheral cells. Two cell surface adiponectin receptors (ADRs) mediate the majority of the known biological actions of adiponectin. Thus far, ADR expression in the brain has been demonstrated in the arcuate and the paraventricular nucleus of hypothalamus, where its activation affects food intake. Recent findings suggest that levels of circulating adiponectin increase after an ischemic stroke, but the role of adiponectin receptor activation in stroke pathogenesis and its functional outcome is unclear. METHODS: Ischemic stroke was induced in C57BL/6 mice by middle cerebral artery occlusion (MCAO) for 1 h, followed by reperfusion. Primary cortical neuronal cultures were established from individual embryonic neocortex. For glucose deprivation (GD), cultured neurons were incubated in glucose-free Locke's medium for 6, 12 or 24 h. For combined oxygen and glucose deprivation (OGD), neurons were incubated in glucose-free Locke's medium in an oxygen-free chamber with 95% N2/5% CO2 atmosphere for either 3, 6, 9, 12 or 24 h. Primary neurons and brain tissues were analysed for Adiponectin and ADRs using reverse transcriptase polymerase chain reaction (RT-PCR), immunoblot and immunochemistry methods. RESULTS: Cortical neurons express ADR1 and ADR2, and that the levels of ADR1 are increased in neurons in response to in vitro or in vivo ischemic conditions. Neurons treated with either globular or trimeric adiponectin exhibited increased vulnerability to oxygen and glucose deprivation which was associated with increased activation of a pro-apoptotic signaling cascade involving p38 mitogen-activated protein kinase (p38MAPK) and AMP-activated protein kinase (AMPK). CONCLUSIONS: This study reveals a novel pathogenic role for adiponectin and adiponectin receptor activation in ischemic stroke. We show that cortical neurons express ADRs and reveal a pro-apoptotic role for ADR1 activation in neurons, which may render them vulnerable to ischemic death.

13.
Metabolism ; 58(4): 560-7, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19303979

ABSTRACT

Apolipoprotein A5 (APOA5) is expressed primarily in the liver and modulates plasma triglyceride levels in mice and humans. Mice overexpressing APOA5 exhibit reduced plasma triglyceride levels. Because there is a tight association between plasma triglyceride concentration and traits of the metabolic syndrome, we used transgenic mice overexpressing human APOA5 to test the concept that these mice would be protected from diet-induced obesity and insulin resistance. Male and female transgenic and wild-type mice on the FVB/N genetic background were fed standard rodent chow or a diet rich in fat and sucrose for 18 weeks, during which time clinical phenotypes associated with obesity and glucose homeostasis were measured. We found that APOA5 transgenic (A5tg) mice were resistant to diet-induced changes in plasma triglyceride but not total cholesterol levels. Body weights were similar between the genotypes for females and males, although male A5tg mice showed a modest but significant increase in the relative size of inguinal fat pads. Although male A5tg mice showed a significantly increased ratio of plasma glucose to insulin, profiles of glucose clearance as evaluated after injections of glucose or insulin failed to reveal any differences between genotypes. Overall, our data showed that there was no advantage to responses to diet-induced obesity with chronic reduction of plasma triglyceride levels as mediated by overexpression of APOA5.


Subject(s)
Apolipoproteins/metabolism , Blood Glucose/metabolism , Homeostasis/genetics , Weight Gain/genetics , Animals , Apolipoprotein A-V , Apolipoproteins/genetics , Body Weight , Female , Insulin Resistance , Lipase/metabolism , Lipids/blood , Male , Mice , Mice, Transgenic
14.
Life Sci ; 83(15-16): 557-62, 2008 Oct 10.
Article in English | MEDLINE | ID: mdl-18762198

ABSTRACT

AIMS: Tanshinone IIA is an important ingredient in the herb danshen (Salvia miltiorrhiza), which has been used to treat cardiovascular diseases such as atherosclerosis and angina for hundreds of years in China. There are numerous reports that TIIA has anti-oxidant properties but the chemical structure indicates that TIIA is fully oxidized. Here, we test the hypothesis that TIIA alters the expression and/or activity of specific anti-oxidation enzymes to protect cells from oxidant damage. MAIN METHODS: We utilized J774 macrophages to model cellular responses to TIIA when challenged with H(2)O(2). Expression and activity levels of several anti-oxidation enzymes were investigated and the only system modulated by TIIA was glutathione peroxidase (GPx). KEY FINDINGS: GPx-1 mRNA levels were significantly increased by TIIA but not the vitamin E analogue, Trolox. GPx activities were also significantly increased by TIIA. Mercaptosuccinic acid inhibited GPx activity and the protective effect of TIIA was attenuated. Thus, TIIA protects cultured macrophages from H(2)O(2)-induced cell death and protection is mediated in large part by TIIA induction of GPx gene expression and activity. SIGNIFICANCE: Because of the importance of GPx in health and because TIIA is able to modulate GPx activity to some extent in cell culture, we suggest that TIIA is a worthwhile candidate for further study in animal models of atherosclerosis and eventually in human prospective trials.


Subject(s)
Glutathione Peroxidase/biosynthesis , Hydrogen Peroxide/antagonists & inhibitors , Hydrogen Peroxide/toxicity , Macrophages/drug effects , Oxidants/toxicity , Phenanthrenes/pharmacology , Protective Agents , Abietanes , Animals , Caspases/metabolism , Catalase/metabolism , Cell Death/drug effects , Cells, Cultured , Chromans/pharmacology , DNA Fragmentation/drug effects , Glutathione Peroxidase/metabolism , Membrane Potentials/drug effects , Mice , Mitochondrial Membranes/drug effects , Oxidative Stress/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Up-Regulation/drug effects
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