1.Analysis of the effect of midazolam on pain in a rat model of lumbar disc herniation based on the p38 MAPK signaling pathway.
Jian LIU ; Yu-Jun YE ; Shu-Min LIU ; Shuang LIU
China Journal of Orthopaedics and Traumatology 2023;36(1):55-60
OBJECTIVE:
To investigate the effect of midazolam on pain in lumbar disc herniation model rats based on p38 MAPK signaling pathway.
METHODS:
Fifty SPF-grade Sprague-Dawley healthy rats, half male and half female, were selected and randomly divided into normal group, model group, and low-dose, medium-dose, high-dose groups. Model group and low-dose, medium-dose, high-dose groups were initially modeled for lumbar disc herniation. Intraperitoneal injection of saline was performed in rats of normal and model groups; and in the low-dose, medium-dose, and high-dose groups, intraperitoneal injection of midazolam was performed with doses of 30, 60, and 90 mg/kg, respectively. Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), 5-hydroxytryptamine (5-HT), β-endorphin (β-EP), substance P (SP), neuropeptide Y (NPY) were detected in the serum of rats by enzyme-linked immunoassay. The expression of p38 MAPK and matrix metalloproteinase-3(MMP-3) protein were detected by Western blot in the tissues of rats of each group.
RESULTS:
The levels of TNF-α, IL-1β and β-EP were higher and the level of 5-HT was lower in the model group than in the normal group(P<0.05);the levels of TNF-α, IL-1β and β-EP were lower and the level of 5-HT was higher in the low-dose, medium-dose and high-dose groups than in the model group(P<0.05). The levels of SP and NPY increased in the model group compared with the normal group (P<0.05) and the levels of SP and NPY decreased in the low-dose, medium-dose and high-dose groups compared with the model group (P<0.05). The expression of p38 MAPK and MMP-3 increased in the model group compared with the normal group (P<0.05); the expression of p38 MAPK and MMP-3 decreased in the low-dose, medium-dose and high-dose compared with the model group(P<0.05).
CONCLUSION
Midazolam may ameliorate the immune inflammatory response in rats with a model of lumbar disc herniation, possibly regulated through the p38MAPK signaling pathway.
Rats
;
Male
;
Female
;
Animals
;
Intervertebral Disc Displacement/pathology*
;
Rats, Sprague-Dawley
;
Matrix Metalloproteinase 3/metabolism*
;
Midazolam
;
Tumor Necrosis Factor-alpha/metabolism*
;
Serotonin/metabolism*
;
MAP Kinase Signaling System/physiology*
;
Pain
;
p38 Mitogen-Activated Protein Kinases/metabolism*
2.Role of p38MAPK signaling pathway in rats with phantom limb pain.
Hui JIANG ; Yongquan CHEN ; Jintao LIU
Journal of Central South University(Medical Sciences) 2018;43(6):589-593
To investigate the role of p38MAPK signal pathway in spinal cord and dorsal root ganglion (DRG) in rats with phantom limb pain and the effects of specific inhibitors.
Methods: Healthy adult male SD rats (n=48) were cut off one side of the sciatic under anesthesia to establish a model of phantom limb pain. In addition, the healthy rats were taken as a sham group (group S, n=24). The animals were scored by observing the action of chewing (0=no chewing, 13=the worst chewing) after the operation and were sacrificed on the following day after the operation. The successful model of phantom limb pain were randomly divided into 2 groups: a phantom limb pain group (group P, n=24) and a phantom limb pain plus inhibitor group (group P+I, n=24). SB203580 was given to the rat at 0.8 mg/kg on every Monday until the rats were sacrificed, the rest of the rats received an equal amount of saline. Eight rats from each group were randomly taken for the determination of levels of P-p38MAPK in spinal cord and DRG before administration and on the 4th, 6th, 8th weekend following the administration, respectively.
Results: In the sham group, no animal developed chewing. Meanwhile, rats in successful model of phantom limb pain group began chewing from the 2nd day after operation with scores at eight to eleven. The chewing scores in the P+I group were reduced after the treatment. Compared with group S, P-p38MAPK levels were elevated in groups of P and P+I (P<0.05 or P<0.01). Compared with group P, P-p38MAPK level was decreased in the group P+I (P<0.05 or P<0.01).
Conclusion: P38MAPK signal pathway involves in the development of phantom limb pain.
Animals
;
Disease Models, Animal
;
Enzyme Inhibitors
;
pharmacology
;
Ganglia, Spinal
;
enzymology
;
Imidazoles
;
pharmacology
;
Male
;
Mastication
;
physiology
;
Phantom Limb
;
enzymology
;
etiology
;
physiopathology
;
Pyridines
;
pharmacology
;
Random Allocation
;
Rats
;
Rats, Sprague-Dawley
;
Sciatic Nerve
;
injuries
;
Self Mutilation
;
enzymology
;
physiopathology
;
Signal Transduction
;
Spinal Cord
;
enzymology
;
p38 Mitogen-Activated Protein Kinases
;
antagonists & inhibitors
;
metabolism
3.Effects of Glucocorticoid-Induced Transcript 1 Gene Deficiency on Glucocorticoid Activation in Asthmatic Mice.
Cheng-Ping HU ; Qiu-Fen XUN ; Xiao-Zhao LI ; Xin-Yue HU ; Ling QIN ; Ruo-Xi HE ; Jun-Tao FENG
Chinese Medical Journal 2018;131(23):2817-2826
Background:
Glucocorticoid (GC) is the first-line therapy for asthma, but some asthmatics are insensitive to it. Glucocorticoid-induced transcript 1 gene (GLCCI1) is reported to be associated with GCs efficiency in asthmatics, while its exact mechanism remains unknown.
Methods:
A total of 30 asthmatic patients received fluticasone propionate for 12 weeks. Forced expiratory volume in 1 s (FEV) and GLCCI1 expression were detected. Asthma model was constructed in wild-type and GLCCI1 knockout (GLCCI1) mice. Glucocorticoid receptor (GR) and mitogen-activated protein kinase phosphatase 1 (MKP-1) expression were detected by polymerase chain reaction and Western blotting (WB). The phosphorylation of p38 mitogen-activated protein kinase (MAPK) was also detected by WB.
Results:
In asthmatic patients, the change of FEV was well positively correlated with change of GLCCI1 expression (r = 0.430, P = 0.022). In animal experiment, GR and MKP-1 mRNA levels were significantly decreased in asthmatic mice than in control mice (wild-type: GR: 0.769 vs. 1.000, P = 0.022; MKP-1: 0.493 vs. 1.000, P < 0.001. GLCCI1: GR: 0.629 vs. 1.645, P < 0.001; MKP-1: 0.377 vs. 2.146, P < 0.001). Hydroprednisone treatment significantly increased GR and MKP-1 mRNA expression levels than in asthmatic groups; however, GLCCI1 asthmatic mice had less improvement (wild-type: GR: 1.517 vs. 0.769, P = 0.023; MKP-1: 1.036 vs. 0.493, P = 0.003. GLCCI1: GR: 0.846 vs. 0.629, P = 0.116; MKP-1: 0.475 vs. 0.377, P = 0.388). GLCCI1 asthmatic mice had more obvious phosphorylation of p38 MAPK than wild-type asthmatic mice (9.060 vs. 3.484, P < 0.001). It was still higher even though after hydroprednisone treatment (6.440 vs. 2.630, P < 0.001).
Conclusions:
GLCCI1 deficiency in asthmatic mice inhibits the activation of GR and MKP-1 and leads to more obvious phosphorylation of p38 MAPK, leading to a decremental sensitivity to GCs.
Trial Registration
ChiCTR.org.cn, ChiCTR-RCC-13003634; http://www.chictr.org.cn/showproj.aspx?proj=5926.
Animals
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Asthma
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drug therapy
;
metabolism
;
Dual Specificity Phosphatase 1
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genetics
;
metabolism
;
Forced Expiratory Volume
;
genetics
;
physiology
;
Glucocorticoids
;
therapeutic use
;
Mice
;
Mice, Knockout
;
Phosphorylation
;
genetics
;
physiology
;
Receptors, Glucocorticoid
;
deficiency
;
genetics
;
metabolism
;
p38 Mitogen-Activated Protein Kinases
;
genetics
;
metabolism
4.Sex Differences in Neuropathology and Cognitive Behavior in APP/PS1/tau Triple-Transgenic Mouse Model of Alzheimer's Disease.
Jun-Ting YANG ; Zhao-Jun WANG ; Hong-Yan CAI ; Li YUAN ; Meng-Ming HU ; Mei-Na WU ; Jin-Shun QI
Neuroscience Bulletin 2018;34(5):736-746
Alzheimer's disease (AD) is the most common form of dementia among the elderly, characterized by amyloid plaques, neurofibrillary tangles, and neuroinflammation in the brain, as well as impaired cognitive behaviors. A sex difference in the prevalence of AD has been noted, while sex differences in the cerebral pathology and relevant molecular mechanisms are not well clarified. In the present study, we systematically investigated the sex differences in pathological characteristics and cognitive behavior in 12-month-old male and female APP/PS1/tau triple-transgenic AD mice (3×Tg-AD mice) and examined the molecular mechanisms. We found that female 3×Tg-AD mice displayed more prominent amyloid plaques, neurofibrillary tangles, neuroinflammation, and spatial cognitive deficits than male 3×Tg-AD mice. Furthermore, the expression levels of hippocampal protein kinase A-cAMP response element-binding protein (PKA-CREB) and p38-mitogen-activated protein kinases (MAPK) also showed sex difference in the AD mice, with a significant increase in the levels of p-PKA/p-CREB and a decrease in the p-p38 in female, but not male, 3×Tg-AD mice. We suggest that an estrogen deficiency-induced PKA-CREB-MAPK signaling disorder in 12-month-old female 3×Tg-AD mice might be involved in the serious pathological and cognitive damage in these mice. Therefore, sex differences should be taken into account in investigating AD biomarkers and related target molecules, and estrogen supplementation or PKA-CREB-MAPK stabilization could be beneficial in relieving the pathological damage in AD and improving the cognitive behavior of reproductively-senescent females.
Alzheimer Disease
;
metabolism
;
pathology
;
psychology
;
Amyloid beta-Protein Precursor
;
genetics
;
metabolism
;
Animals
;
Cyclic AMP Response Element-Binding Protein
;
metabolism
;
Cyclic AMP-Dependent Protein Kinases
;
metabolism
;
Disease Models, Animal
;
Female
;
Hippocampus
;
metabolism
;
pathology
;
Humans
;
Inflammation
;
metabolism
;
pathology
;
psychology
;
Male
;
Maze Learning
;
physiology
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
Neurofibrillary Tangles
;
metabolism
;
pathology
;
Plaque, Amyloid
;
metabolism
;
pathology
;
psychology
;
Presenilin-1
;
genetics
;
metabolism
;
Sex Characteristics
;
Spatial Memory
;
physiology
;
p38 Mitogen-Activated Protein Kinases
;
metabolism
;
tau Proteins
;
genetics
;
metabolism
5.Role of c-Jun N-terminal kinase-mediated FOXO3a nuclear translocation in neuronal apoptosis in neonatal rats with hypoxic-ischemic brain damage.
De-Yuan LI ; Jin-Lin WU ; Li-Li LUO ; Li-Na QIAO ; Zhong-Qiang LIU ; Guo-Yan LU ; Yang WANG
Chinese Journal of Contemporary Pediatrics 2017;19(4):458-462
OBJECTIVETo explore the mechanisms of neuroprotective effects of c-Jun N-terminal kinase (JNK)/FOXO3a transcription factor signaling pathway inhibition on hypoxic-ischemic neuronal apoptosis in neonatal rats with hypoxic-ischemic brain damage (HIBD).
METHODSSixty-four 7-day-old Sprague-Dawley rats were divided into four groups: hypoxia-ischemia (HI), sham-operated, JNK specific inhibitor AS601245-treated, and DMSO vehicle. Rats' cerebral cortexes were collected at 24 hours after HI. Western blot was used to detect the protein expression of JNK, p-JNK, FOXO3a, nuclear and cytoplasmic FOXO3a, Bim, and CC3. TUNEL staining was used to detect the apoptotic cells.
RESULTSCompared with the sham-operated group, p-JNK protein increased (P<0.01), nuclear protein of FOXO3a increased (P<0.01), cytoplasmic protein decreased (P<0.01), and pro-apoptotic proteins Bim and CC3 increased 24 hours after HI (P<0.01). Compared with the HI and DMSO vehicle groups, p-JNK protein was reduced (P<0.01), nuclear protein of FOXO3a was also reduced (P<0.01), cytoplasmic protein increased (P<0.01), and Bim and CC3 proteins decreased (P<0.01) in the AS601245-treated group 24 hours after HI. TUNEL positive cells were reduced in the AS601245-treated rats compared with the HI and DMSO vehicle groups 24 hours after HI (P<0.01).
CONCLUSIONSJNK activity increases in the neonatal rat brain with HI damage. JNK activity inhibition can inhibit FOXO3a translocation from cytoplasm to nucleus and downregulate the levels of pro-apoptotic proteins Bim and CC3, leading to the reduction of neuronal apoptosis.
Active Transport, Cell Nucleus ; Animals ; Animals, Newborn ; Apoptosis ; Cell Nucleus ; metabolism ; Female ; Forkhead Box Protein O3 ; metabolism ; Hypoxia-Ischemia, Brain ; pathology ; JNK Mitogen-Activated Protein Kinases ; physiology ; Male ; Neurons ; pathology ; Rats ; Rats, Sprague-Dawley
6.Dual-specificity Phosphatase 1 Deficiency Induces Endometrioid Adenocarcinoma Progression via Activation of Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase Pathway.
Yuan YANG ; Jing-Yi ZHOU ; Li-Jun ZHAO ; Bao-Rong GAO ; Xiao-Ping WAN ; Jian-Liu WANG
Chinese Medical Journal 2016;129(10):1154-1160
BACKGROUNDPreviously, we reported that dual-specificity phosphatase 1 (DUSP1) was differentially expressed in endometrioid adenocarcinoma (EEA). However, the role of DUSP1 in EEA progression and the relationship between DUSP1 and medroxyprogesterone (MPA) are still unclear.
METHODSThe expression of DUSP1 in EEA specimens was detected by immunohistochemical analysis. The effect of DUSP1 on cell proliferation was analyzed by Cell Counting Kit 8 and colony formation assay, and cell migration was analyzed by transwell assay. MPA-induced DUSP1 expression in EEA cells was measured by Western blot.
RESULTSDUSP1 expression was deficient in advanced International Federation of Gynecology and Obstetrics stage, high-grade and myometrial invasive EEA. In EEA cell lines (Hec1A, Hec1B, RL952, and Ishikawa), the DUSP1 expression was substantially higher in Ishikawa cells than in other cell lines (P < 0.05). Knockdown of DUSP1 promoted Ishikawa cells proliferation, migration, and activation of mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/Erk) pathway. MPA-induced DUSP1 expression and inhibited MAPK/Erk pathway in Ishikawa cells.
CONCLUSIONSOur data suggest that DUSP1 deficiency promotes EEA progression via MAPK/Erk pathway, which may be reversed by MPA, suggesting that DUSP1 may serve as a potential therapeutic target for the treatment of EEA.
Carcinoma, Endometrioid ; metabolism ; Cell Culture Techniques ; Cell Proliferation ; genetics ; physiology ; Dual-Specificity Phosphatases ; genetics ; metabolism ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Female ; Humans ; Mitogen-Activated Protein Kinases ; metabolism
7.Extracellular signal-regulated kinase signaling pathway regulates the endothelial differentiation of periodontal ligament stem cells.
Hong ZHU ; Lankun LUO ; Ying WANG ; Jun TAN ; Peng XUE ; Qintao WANG
Chinese Journal of Stomatology 2016;51(3):154-159
OBJECTIVETo investigate the effect of extracellular signal-regulated kinase (ERK) signaling pathway on the endothelial differentiation of periodontal ligament stem cells (PDLSC).
METHODSHuman PDLSC was cultured in the medium with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) to induce endothelial differentiation. Endothelial inducing cells was incubated with U0126, a specific p-ERK1/2 inhibitor. PDLSC from one person were randomly divided into four groups: control group, endothelial induced group, endothelial induced+DMSO group and endothelial induced+U0126 group. The protein expression of the p-EKR1/2 was analyzed by Western blotting at 0, 1, 3, 6 and 12 hours during endonthelial induction. The mRNA expressions of CD31, VE-cadherin, and VEGF were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) after a 7-day induction. The proportion of CD31(+) to VE-cadherin(+) cells was identified by flow cytometry, and the ability of capillary-like tubes formation was detected by Matrigel assay after a 14-day induction. The measurement data were statistically analyzed.
RESULTSPhosphorylated ERK1/2 protein level in PDLSC was increased to 1.24±0.12 and 1.03±0.24 at 1 h and 3 h respectively, during the endothelial induction (P<0.01). The mRNA expressions of CD31 and VEGF in induced+U0126 group were decreased to 0.09±0.18 and 0.49±0.17, which were both significantly different with those in induced group (P<0.05). The proportion of CD31(+) to VE-cadherin(+) cells of induced+U0126 group were decreased to 5.22±0.85 and 3.56±0.87, which were both significantly different with those in induced group (P<0.05). In Matrigel assay, the branching points, tube number and tube length were decreased to 7.0±2.7, 33.5±6.4, and (15 951.0±758.1) pixels, which were all significantly different with those in induced group (P<0.05).
CONCLUSIONSThe endothelial differentiation of PDLSC is positively regulated by ERK signaling pathway. Inhibition of ERK1/2 phosphorylation could suppress endothelial differentiation of PDLSC.
Antigens, CD ; genetics ; metabolism ; Butadienes ; pharmacology ; Cadherins ; genetics ; metabolism ; Cell Differentiation ; Endothelial Cells ; cytology ; physiology ; Enzyme Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; physiology ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; Mitogen-Activated Protein Kinase 3 ; antagonists & inhibitors ; metabolism ; Nitriles ; pharmacology ; Periodontal Ligament ; cytology ; metabolism ; Phosphorylation ; Platelet Endothelial Cell Adhesion Molecule-1 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Signal Transduction ; Stem Cells ; cytology ; physiology ; Time Factors ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; pharmacology
8.Loss of IκB kinase β promotes myofibroblast transformation and senescence through activation of the ROS-TGFβ autocrine loop.
Liang CHEN ; Zhimin PENG ; Qinghang MENG ; Maureen MONGAN ; Jingcai WANG ; Maureen SARTOR ; Jing CHEN ; Liang NIU ; Mario MEDVEDOVIC ; Winston KAO ; Ying XIA
Protein & Cell 2016;7(5):338-350
Using forward and reverse genetics and global gene expression analyses, we explored the crosstalk between the IκB kinase β (IKKβ) and the transforming growth factor β (TGFβ) signaling pathways. We show that in vitro ablation of Ikkβ in fibroblasts led to progressive ROS accumulation and TGFβ activation, and ultimately accelerated cell migration, fibroblast-myofibroblast transformation and senescence. Mechanistically, the basal IKKβ activity was required for anti-oxidant gene expression and redox homeostasis. Lacking this activity, IKKβ-null cells showed ROS accumulation and activation of stress-sensitive transcription factor AP-1/c-Jun. AP-1/c-Jun activation led to up-regulation of the Tgfβ2 promoter, which in turn further potentiated intracellular ROS through the induction of NADPH oxidase (NOX). These data suggest that by blocking the autocrine amplification of a ROS-TGFβ loop IKKβ plays a crucial role in the prevention of fibroblast-myofibroblast transformation and senescence.
Adenoviridae
;
genetics
;
Animals
;
Autocrine Communication
;
physiology
;
Cell Line
;
Cell Movement
;
Cellular Senescence
;
Genetic Vectors
;
genetics
;
metabolism
;
I-kappa B Kinase
;
deficiency
;
genetics
;
metabolism
;
JNK Mitogen-Activated Protein Kinases
;
metabolism
;
Mice
;
Myofibroblasts
;
cytology
;
metabolism
;
NADPH Oxidases
;
metabolism
;
Oxidative Stress
;
Promoter Regions, Genetic
;
Reactive Oxygen Species
;
metabolism
;
Signal Transduction
;
Superoxide Dismutase
;
genetics
;
metabolism
;
Transcription Factor AP-1
;
metabolism
;
Transforming Growth Factor beta
;
genetics
;
metabolism
;
Up-Regulation
9.Effect of Chinese herbal drug-containing serum for activating blood, activating blood and dispelling toxin on TNF-alpha-induced adherence between endothelial cells and neutrophils and the expression of MAPK pathway.
Chun-yu GUO ; Xiao-juan MA ; Qian LIU ; Hui-jun YIN ; Da-zhuo SHI
Chinese Journal of Integrated Traditional and Western Medicine 2015;35(2):204-209
OBJECTIVETo explore the effect of drug-containing serum of Chinese herbal compounds [Xiongshao Capsule (XS, for activating blood) and Huanglian Capsule (HL, for dispelling toxin)] on tumor necrosis factor-alpha (TNF-alpha)-induced adherence between human umbilical vein endothelial cells (HUVECs) and polymorphonuclear neutrophils (PMN), inflammatory reaction and expression of related proteins in mitogen-activated protein kinase (MAPK) pathway.
METHODSThirty-two rats were randomly divided into four groups (8 in each group) using random digit table: the blank control group treated with distilled water, the test group I treated with Chinese herbal compound of XS (0.135 g/kg), the test group II treated with Chinese herbal compound of HL (0.135 g/kg), and the test group Ill treated with Chinese herbal compound of XS (0.135 g/kg) and HL (0.135 g/kg). All medication was given by gastrogavage once a day for a week. Rats' blood serum was harvested 1 h after the last administration to prepare drug-containing serum. HUVECs were exposed to TNF-alpha (100 ng/mL) to induce cell injury model and incubated with corresponding drug-containing serum (10%) for 24 h. Normal rats' serum was given to cells in the blank control group and the model group, while XC + HL containing serum was given to cells in the rest 3 groups. The adherence of HUVECs and PMN cells was detected by using rose bengal strain. Levels of E-selectin, intercellular adhesion molecule-1 (ICAM-1), and interleukin-1beta (IL-1P) in the supernatant of cultured HU-VECs were determined by ELISA. Protein expressions of mitogen-activated protein kinases p38 (p38MAPK) and extracellular signal-regulated kinase 1/2 (ERK 12) were determined by Western blot.
RESULTSCompared with the blank control group, HUVECs were seriously injured; PMN adherence amount significantly increased; levels of E-selectin, ICAM-1, and IL-1beta increased; expression levels of p-p38MAPK and p-ERK 1/2 in the supernatant of HUVECs significantly increased in the model group (all P < 0.01). Compared with the model group, HUVECs-PMN adherence amount decreased (P < 0.05); levels of E-selectin, ICAM-1, and IL-1 beta in the supernatant of HUVECs decreased (P < 0.01, P < 0.05); expression levels of p-p38MAPK and p-ERK 1/2 of endothelial cells decreased in the test group I, II, and III (P < 0.01).
CONCLUSIONSDrug-containing serums of activating blood, activating blood and dispelling toxin could attenuate TNF-alpha induced injury of HUVECs, inhibit HUVECs-PMN adherence and the release of adhesion factors. Its mechanism might be involved with protein phosphorylation of p38MAPK and ERK 1/2 in the MAPK pathway.
Animals ; Drugs, Chinese Herbal ; therapeutic use ; E-Selectin ; Endothelial Cells ; physiology ; Human Umbilical Vein Endothelial Cells ; Humans ; Inflammation ; Intercellular Adhesion Molecule-1 ; metabolism ; Interleukin-1beta ; Mitogen-Activated Protein Kinase 3 ; Neutrophils ; Rats ; Serum ; Tumor Necrosis Factor-alpha ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism
10.The effects of DR2 on myocardial ischemic postconditioning and its underlying mechanisms.
Hong-Zhu LI ; Jun GAO ; Xiao-Min HAO ; Li-Min ZHANG ; Jun-Ting CHEN
Chinese Journal of Applied Physiology 2014;30(4):301-305
OBJECTIVETo study the effects of dopamin receptors-2 (DR2) on myocardial ischemic postconditioning and explore its underlying mechanisms.
METHODSThe myocardial ischemic postconditioning (PC) model was established in cultured primary rat neonatal cardiomyocytes which were then randomly assigned in the following groups: Nomial control group, Isehemia/reperfusion (L'R) group, PC (ischemic postconditioning) group, PC + Bro (Bromocriptine, a DB2 antagonist) group, PC + Hal (Haloperidol, a DB2 repressor) and PC + Hal + Bro groups. The lactate dehydrogenase (LDH) and superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in cell medium were analyzed by colorunetry. The cell ultrastructure changes were observed by transmission electron microscope. The cell apoptosis was analyzed using flowcytometiy. The protein expression level of D112 and activity of p-p38 and p-JNK were detected by Western blot.
RESULTSCompared with the nonnal control group, hR increased the protein expression level of DB2, enhanced LDH activity and MDA content, promoted cell injury and apoptosis, decreased SOD activity, up-regulated the activity of p-p38 and p-JNK. Compared with the hR group, although PC further increased the expression of DR2 protein, it decreased LDH activity and MDA content, cell injury and apoptosis, increased SOD activity, down-regulated activity of p-p38 and p-JNK. Bromocriptine treatment further enhanced PC-induced canlioprotective effect, yet Hal addition attenuated this enhancing effect exerted by bromocriptine.
CONCLUSIONThe activation of DB2 is involved in the protective effect of ischemic postconditioning on myocardial ischemia/reperfusion injury through down-regulating the activity of p-p38 and p-JNK.
Animals ; Apoptosis ; Cells, Cultured ; Ischemic Postconditioning ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Myocardial Reperfusion Injury ; prevention & control ; Myocytes, Cardiac ; pathology ; Rats ; Rats, Wistar ; Receptors, Dopamine D2 ; physiology ; p38 Mitogen-Activated Protein Kinases ; metabolism

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