Recent studies have documented that Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) pathway can modulate the apoptotic program in a myocardial ischemia/reperfusion (I/R) model. To date, however, limited studies have examined the role of JAK3 on myocardial I/R injury. Here, we investigated the potential effects of pharmacological JAK3 inhibition with JANEX-1 in a myocardial I/R model. Mice were subjected to 45 min of ischemia followed by varying periods of reperfusion. JANEX-1 was injected 1 h before ischemia by intraperitoneal injection. Treatment with JANEX-1 significantly decreased plasma creatine kinase and lactate dehydrogenase activities, reduced infarct size, reversed I/R-induced functional deterioration of the myocardium and reduced myocardial apoptosis. Histological analysis revealed an increase in neutrophil and macrophage infiltration within the infarcted area, which was markedly reduced by JANEX-1 treatment. In parallel, in in vitro studies where neutrophils and macrophages were treated with JANEX-1 or isolated from JAK3 knockout mice, there was an impairment in the migration potential toward interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1), respectively. Of note, however, JANEX-1 did not affect the expression of IL-8 and MCP-1 in the myocardium. The pharmacological inhibition of JAK3 might represent an effective approach to reduce inflammation-mediated apoptotic damage initiated by myocardial I/R injury.
Animals ; Apoptosis/drug effects ; Cell Movement/drug effects ; Chemokines/pharmacology ; Heart Function Tests/drug effects ; Inflammation/pathology ; Janus Kinase 3/*antagonists & inhibitors/metabolism ; Macrophages/drug effects/metabolism/pathology ; Male ; Mice ; Mice, Inbred C57BL ; Myocardial Reperfusion Injury/drug therapy/*enzymology/physiopathology/*prevention & control ; Myocardium/enzymology/pathology ; Myocytes, Cardiac/drug effects/metabolism/pathology ; Neutrophils/drug effects/metabolism/pathology ; Quinazolines/pharmacology/therapeutic use

OBJECTIVETo explore the possible mechanism of lipopolysaccharide (LPS)-induced cardiomyocyte hypertrophy in rats.

METHODSNeonatal rat cardiomyocytes cultured in vitro were stimulated with 100 µg/L LPS for 1, 4 or 8 h and scanned by atomic force microscopy (AFM) for measurement of the two-dimensional area, three-dimensional surface area and volume of each cell. The total proteins and Na(+)-K(+)-ATPase activity in the cardiomyocytes were determined. The same measurements were also carried out in neonatal rat cardiomyocyte cultures stimulated by 0.5 µmol/L ouabain for 8 h and the total protein levels were measured.

RESULTSFollowing a 8-hour stimulation with LPS, the two-dimensional area, three-dimensional surface area and volume of the single cardiomyocyte became enlarged and the total cellular proteins increased significantly as compared with those in the normal control cells (P < 0.05). LPS treatment for 4 and 8 h resulted in significantly decreased activity of Na(+)-K(+)-ATPase in the cardiomyocytes (P < 0.05). In the cells treated with ouabain for 8 h, the two-dimensional area, three-dimensional surface area, volume of the single cardiomyocyte and the total cellular proteins increased significantly in comparison with the normal control group (P < 0.05).

CONCLUSIONLPS can result in cardiomyocyte hypertrophy in rats possibly in relation to lowered Na(+)-K(+)-ATPase activity in the cardiomyocytes after LPS exposure.

Animals ; Animals, Newborn ; Cell Enlargement ; drug effects ; Cells, Cultured ; Hypertrophy ; chemically induced ; Lipopolysaccharides ; Myocytes, Cardiac ; enzymology ; pathology ; Rats ; Rats, Wistar ; Sodium-Potassium-Exchanging ATPase ; metabolism

OBJECTIVETo explore changes of mitochondrial structure and functions, as well as the protection of ligustrazine in the process of myocardial hypertrophy.

METHODSNeonatal myocardial cells were isolated and cultured with angiotensin II (Ang II) for 72 or 96 h. The total protein content was detected using BCA method. The cell diameter was measured by inverted microscope, by which to reflect the proliferation situation of cardiomyocytes. The mitochondrial membrane potential (MMP) was measured by fluorescence microscope. The mitochondrial monoamine oxidase (MAO) activity was detected by spectrophotometer. The mitochondrial cytochrome oxidase (COX) activity and the mitochondrial damage percentage were detected by microplate reader, by which to reflect the damage of mitochondrial outer membrane's structure and the membranes' function. Also, cells were treated with ligustrazine and losartan and then the pharmacological effects on the mitochondrial structure and functions in the myocardial cells treated with Ang II were observed.

RESULTSAt 72 h and 96 h, when compared with the blank group, cells treated with Ang II had increased total protein content (P < 0.01) and enlarged diameter (P < 0.01). Treated with Ang II, the MAO activity and the outer membrane damage percentage of myocardial cells significantly increased (P < 0.01), and mitochondrial COX activity and the mitochondrial MMP significantly decreased (P < 0.01). Compared with the model group at the same time period, ligustrazine significantly reduced myocardial cells' total protein content and myocardial cell diameter, and significantly decreased myocardial cells' MAO activity, increased mitochondrial COX activity, improved the outer membrane damage percentage and inner membrane MMP at 72 and 96 h, all showing statistical difference (P < 0.01, P < 0.05).

CONCLUSIONSDuring the process of myocardial hypertrophy existed the damage to the mitochondrial structure and functions. Ligustrazine protected the mitochondrial structure and functions of the myocardial cells in reversing Ang II induced myocardial cell hypertrophy.

Angiotensin II ; adverse effects ; Animals ; Cardiomyopathy, Hypertrophic ; chemically induced ; metabolism ; pathology ; Cells, Cultured ; Electron Transport Complex IV ; metabolism ; Mitochondria, Heart ; drug effects ; enzymology ; Monoamine Oxidase ; metabolism ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Pyrazines ; pharmacology ; Rats ; Rats, Sprague-Dawley

The protective effect of aspirin during exposure to heat stress in broiler chickens was investigated. We assayed pathological damage, expression and distribution of Hsp90 protein and hsp90 mRNA expression in chicken heart tissues after oral administration of aspirin following exposure to high temperature for varying times. Heat stress induced increases in plasma aspartate aminotransferase, creatine kinase and lactate dehydrogenase activities while causing severe heart damage, which was characterized by granular and vacuolar degeneration, nuclear shrinkage and even myocardium fragmentation in cardiac muscle fibers. After aspirin administration, myocardial cells showed fewer pathological lesions than broilers treated with heat alone. A high positive Hsp90 signal was always detected in the nuclei of myocardial cells from broilers treated with aspirin, while in myocardial cells treated with heat alone, Hsp90 in the nuclei decreased, as did that in the cytoplasm. Aspirin induced rapid and significant synthesis of Hsp90 before and at the initial phase of heat stress, and significant expression of hsp90 mRNA was stimulated throughout the experiment when compared with cells exposed to heat stress alone. Thus, specific pre-induction of Hsp90 in cardiovascular tissue was useful for resisting heat stress damage because it produced stable damage-related enzymes and fewer pathologic changes.
Animals ; Anti-Inflammatory Agents, Non-Steroidal/pharmacology ; Aspirin/*pharmacology ; Cell Nucleus/genetics ; Chickens ; Gene Expression Regulation/*drug effects ; HSP90 Heat-Shock Proteins/*genetics ; Hot Temperature ; Myocytes, Cardiac/*drug effects/enzymology/pathology ; Stress, Physiological/*drug effects

OBJECTIVETo test whether postconditioning could inhibit the expression of phospho-JNK (P-JNK) mitogen activated protein kinase (MAPK) and study its relation to apoptosis of cardiocyte.

METHODSSixty rats were randomly divided into six groups: sham, reperfusion injury (R/I), postconditioning (Post), SP600125 (I_JNK), anisomycin and postconditioning (Ani+Post) and anisomycin (Ani) groups. After acute myocardial infarction was induced in rats, placebo solution (DMSO), SP600125 (6 mg/kg) or anisomycin (2 mg/kg) was injected through jugular vein 5 min before reperfusion; 6 h later 3 rats of each group were executed and the hearts were separated to measure the signaling molecules (phospho-JNK, TNF alpha, Caspase-8, Bcl-2/Bax, cytochrome-c). Twenty-two hours later hemodynamic data were measured in the left rats, and then blood samples were taken to determine serum markers of cardiac damage, and hearts were separated to measure the infarction area and cardiocyte apoptosis.

RESULTPostconditioning improved +/-DP/DTmax of left ventricle, limited infarct area, relieved apoptosis and necrosis of cardiocytes, and inhibited the expression of P-JNK (1.12 +/-0.21 Compared with 1.90 +/-0.32, P<0.05). At the same time the levels of TNFalpha Caspase-8, Bax and Cyt-c were lower in Post group than those in R/I group, but Bcl-2 expression levels were higher. I_JNK group presented the similar protection effect of postconditioning [TUNEL index: (6.23 +/-2.43)% Compared with (18.22 +/-5.10)%, P<0.05; Infarct area: (23.44 +/-6.34)% Compared with (42.31 +/-8.21)%, P<0.05]. On the other hand, Ani+Post group partially lost cardioprotection effect [TUNEL index: (14.12 +/-2.00)% Compared with (18.22 +/-5.10)%,P>0.05; Infarct area: (35.27 +/-5.28)% Compared with (42.31+/-8.21)%,P>0.05], because of the activation of JNK MAPK.

CONCLUSIONPostconditioning can inhibit phosphorylation of JNK MAPK, which attenuates cardiocyte apoptosis by both extrinsic and mitochondria pathway.

Animals ; Apoptosis ; drug effects ; Ischemic Preconditioning, Myocardial ; JNK Mitogen-Activated Protein Kinases ; metabolism ; pharmacology ; Male ; Myocardial Infarction ; enzymology ; pathology ; therapy ; Myocardial Reperfusion Injury ; prevention & control ; Myocytes, Cardiac ; enzymology ; pathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the role of focal adhesion kinase (FAK) in cardiac hypertrophy induced by hypertension.

METHODSUsing immunofluorescent labeling, confocal microscopy and Western blot, the expression and subcellular location of FAK-pSer722 and FAK-pSer910 were determined in cardiac myocytes of the left ventricles from 2, 6, 12, and 18 month-old spontaneously hypertensive heart failure (SHHF) rats and age-matched Wistar-Kyoto (WKY) control rats, respectively.

RESULTSThere was no obvious difference in FAK-pSer722 and FAK-pSer910 expression between 2 month-old SHHF and WKY rats. In contrast with the control groups, the expression of FAK-pSer722 and FAK-pSer910 significantly increased in cardiac myocytes of the left ventricle, from 6, 12 and 18 month-old SHHF rats. Both FAK-pSer722 and FAK-pSer910 were translocated and acummulated in nuclei of cardiac myocytes from 6, 12, and 18 month-old SHHF rats.

CONCLUSIONPhosphorylation and translocation of serine 722 and serine 910 of phosphorylated FAK play an important role in the de-compensatory cardiac hypertrophy.

Animals ; Cardiomegaly ; enzymology ; metabolism ; Cell Nucleus ; enzymology ; metabolism ; Focal Adhesion Kinase 1 ; metabolism ; Focal Adhesion Protein-Tyrosine Kinases ; metabolism ; physiology ; Heart Failure ; Heart Ventricles ; pathology ; Hypertension ; enzymology ; Hypertrophy ; enzymology ; Myocytes, Cardiac ; enzymology ; pathology ; Phosphorylation ; Protein Transport ; drug effects ; physiology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Serine ; metabolism ; Signal Transduction ; drug effects ; physiology

OBJECTIVETo explore the molecular biological mechanism for tanshinone II A reversing left ventricular hypertrophy, it would be studying the effect of tashinone on the endothelial nitric oxide synthase (eNOS) and protein kinase C (PKC) in the hypertrophic cadiocyte of rats suffered abdominal aorta constriction.

METHODSD rats were operated with abdominal aorta constriction and 8 rats were done with sham surgery. After 4 weeks, all rats were divided into 4 groups: myocardial hypertrophy group, low dose tanshinone II A group (10 mg x kg(-1) x d(-1)), high dose tanshinone II A group (20 mg x kg(-1) x d(-1)) and valsartan group (10 mg x kg(-1) d(-1) intragastric administration). 8 weeks later, the rats were used to measure the left ventricular mass index (LVMI) with the tissue of left ventricle and myocardial fiber dimension (MFD) by pathological section and HE stain, to detect the nitric oxide content by nitrate reductase, to detect the genic expression of eNOS by RT-PCR and to detect the activity of protein kinase C (PKC) by Western blotting.

RESULT1) The blood pressure in group myocardial hypertrophy [(186 +/- 13) mmHg] and tansginone II A [low and high dose (188 +/- 11,187 +/- 14) mmHg] was obviously higher than that in group sham surgery and valsartan group [vs (117 +/- 8, 136 +/- 15) mmHg, P < 0.01]. But there was no difference between group myocardial hypertrophy and group tanshinone II A (low and high dose). 2) The LVMI and MFD were obviously higher in group tanshinone II A low and high dose) and group valsartan than those in group sham surgery (P < 0.05), and lower than those in group myocardial hypertrophy (P < 0.01). 3) The NO level was obviously higher in group tanshinone II A (low and high dose) and group valsartan than that in group myocardial hypertrophy (12.78 +/- 1.66, 11.95 +/- 1.39, 12.26 +/- 2.08 vs 5.83 +/- 1.06) micromol x L(-1), (P < 0.01 ), and lower than that in group sham surgery (vs 19.35 +/- 1.47) micromol x L(-1), (P < 0.05). 4) The expressive level of eNOS mRNA and protein in myocardial hypertrophy group was less than that in other groups (P < 0.01). And valsartan group was less than tanshinone II A groups and sham surgery group (P < 0.05), but there were no difference among the two tanshinone II A groups and sham surgery group. 5) The level of PKC protein in group myocardial hypertrophy was obviously higher than that in all the other groups (1.291 +/- 0.117 vs 0.563 +/- 0.094, 0.605 +/- 0.051, 0.519 +/- 0.062, 0.827 +/- 0.086, P < 0.01), and the level in group valsartan was higher than that in group sham operation and group tanshinone II A (low and high dose).

CONCLUSIONNO/NOS system in local myocardium has close relationship with the pathological process for myocardial hypertrophy. Tanshinone II A can produce the pharmacological action to reverse myocardial hypertrophy by inhibiting the activity of PKC and promoting the genic expression of eNOS in local myocardium and the production of endogenous NO.

Animals ; Aorta, Abdominal ; pathology ; Benzofurans ; pharmacology ; Blood Pressure ; drug effects ; Cardiomyopathy, Hypertrophic ; complications ; enzymology ; physiopathology ; Constriction, Pathologic ; complications ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Endothelium, Vascular ; drug effects ; enzymology ; Female ; Gene Expression Regulation, Enzymologic ; drug effects ; Heart Ventricles ; drug effects ; metabolism ; pathology ; physiopathology ; Male ; Myocytes, Cardiac ; drug effects ; enzymology ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; genetics ; metabolism ; Protein Kinase C ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats

Cardiomyocyte hypertrophy is a major cause of morbidity and mortality worldwide. The aim of this study is to determine the effects of sodium tanshinone IIA sulfonate (STS) on cardiomyocyte hypertrophy induced by angiotensin II (Ang II) in vivo and in vitro. In long-term treatment, adult Wistar rats were infused with Ang II for three weeks via osmotic mini-pumps and some of them were given intragastrically of STS. Left ventricle was isolated; the ratio of left ventricular weight to body weight and systolic blood pressure (SBP) were determined and heart morphometry was assessed after hematoxylin and eosin staining. Results indicated STS inhibited Ang II-induced increases in myocyte diameter and decreased the LVW/BW ratio independent of decreasing systolic blood pressure. In vitro, treatment of cultured cardiomyocytes with STS inhibited Ang II-induced increase in cell size, protein synthesis, ANP expression, activation of extracellular signal-regulated kinase (ERK) and ERK kinase (MEK). Then we reexamined the mechanism of STS-induced anti-hypertrophic effects. Results revealed MEK inhibitor U0126 (20 microM) markedly enhanced STS-induced depressions in [3H]leucine incorporation and ANP expression. In conclusion, MEK/ERK pathway plays a significant role in the anti-hypertrophic effects of STS.
Rats, Wistar ; Rats ; Phenanthrenes/chemistry/*pharmacology ; Myocytes, Cardiac/*drug effects/enzymology/pathology ; Molecular Structure ; Mitogen-Activated Protein Kinase Kinases/*metabolism ; MAP Kinase Signaling System/*drug effects ; Extracellular Signal-Regulated MAP Kinases/*metabolism ; Enzyme Activation/drug effects ; Cardiomegaly/chemically induced/enzymology/*metabolism/pathology ; Animals ; Angiotensin II/*antagonists & inhibitors/pharmacology

OBJECTIVETo investigate the role of the TLR4-NFκB-TNFα inflammation pathway on: lipopolysaccharide (LPS)-induced neonatal rat cardiomyocyte injury and the possible protective effects of salvianolic acid B (Sal B).

METHODSWistar rat (1-2 days old) cardiomyocytes were isolated and cultured. Sal B 10(-5)mol/L, 10(-6)mol/L and 10(-7)mol/L were pre-treated for 6 h in the culture medium. LPS (1 μg/mL) was added to mol/the culture medium and kept for 6 h to induce inflammation injury. The concentration of lactate dehydrogenase (LDH) in the supernatant was detected by spectrophotometry. The concentrations of tumor necrosis factor α (TNFα) and heat shock protein 70 (HSP70) in the supernatant were detected by enzyme linked immunosorbent assay. The protein expressions of toll, such as receptor 4 (TLR4) and nuclear factor kappa B (NFκB) were detected by immunohistochemistry. The mRNA expressions of TLR4 and NFκB were detected by real-realtime reverse transcription polymerase chain reaction (RT-PCR).

RESULTS(1) The concentrations of LDH and: TNFα in the LPS control group were significantly higher than those in the control group (561.41±67.39 U/L and 77.94±15.08 pg/mL, versus 292.13±26.02 U/L and 25.39±16.53 pg/mL, respectively, P<0.01, P<0.05). Compared with the LPS control group, the concentrations of LDH and TNFα were significantly decreased in the Sal B 10(-5)mol/L pre-treated group (451.76±83.96 U/L and 34.00±10.38 pg/mL, respectively, P<0.05). (2) The TLR4 and NFκB protein expression area in the LPS control group were significantly higher than those in the control group (1712.41±410.12 μm(2) and 2378.15±175.29 μm(2), versus 418.62±24.42 μm(2) and 1721.74±202.87 μm(2), respectively, P<0.01). The TLR4 and NFκB protein expression internal optical density (IOD) values in the LPS control group were also significantly higher than those in the control group (3.06±0.33 and 7.20±1.04, versus 0.91±0.21 and 4.24±0.48, respectively, P<0.05 and P<0.01). Compared with the LPS control group, the TLR4 and NFκB protein expression areas were significantly decreased in the Sal B 10(-5)mol/L pre-treated group (1251.54±133.82 μm(2) and 1996.37±256.67 μm(2), respectively, P<0.05), the TLR4 and NFκB protein expression IOD values were also significantly decreased in the Sal B 10(-5)mol/L pre- mol/pretreated group (1.92±0.28 and 5.17±0.77, respectively, treated P<0.05). (3) The TLR4 and NFκB mRNA expressions (2(-ΔΔ)CT value) in the LPS control group were significantly higher than those in the control group (3.16±0.38 and 5.03±0.43 versus 1.04±0.19 and 1.08±0.21, respectively, P<0.01). Compared with the LPS control group, the TLR4 and NFκB mRNA expressions (2(-ΔΔ) -CT value) were significantly decreased in the Sal B 10(-5)mol/L pre- mol/pretreated group (1.34±0.22 and 1.74±0.26, respectively, treated P<0.05). The concentration of HSP70 did not show any 0.05).

CONCLUSIONSThe TLR4-NFκB-TNFα pathway was quickly activated: and was independent of HSP70 in the early phase of neonatal cardiomyocyte injury induced by LPS. The protective effects of Sal B may be through inhibiting the TLR4-NFκB-TNFα pathway and are dose-dependent.

Animals ; Animals, Newborn ; Benzofurans ; chemistry ; pharmacology ; Gene Expression Regulation ; drug effects ; HSP70 Heat-Shock Proteins ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lipopolysaccharides ; pharmacology ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; NF-kappa B ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Signal Transduction ; drug effects ; Subcellular Fractions ; drug effects ; enzymology ; Toll-Like Receptor 4 ; genetics ; metabolism ; Transcription, Genetic ; drug effects ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo observe the effects of sodium tanshinone II A sulfonate (STS) on angiotensin II (Ang II)-induced hypertrophy of myocardial cells through the expression of phosphorylated extracellular signal-regulated kinase (p-ERK1/2).

METHODSIn the primary culture of neonatal rat myocardial cells, the total protein content in myocardial cells was determined by coomassie brilliant blue and the protein synthesis rate was measured by [3H]-Leucine incorporation as indexes for hypertrophy of myocardial cells. The expression of p-ERK1/2 was determined using Western blot and immunofluorescence labeling.

RESULTS(1) The total protein and protein synthesis rate increased significantly in contrast to the control group after the myocardial cells were stimulated by Ang II (1 micromol/L) for 24 h; STS markedly inhibited the increment of the total protein level induced by Ang II and the syntheses of protein. (2) After pretreatment of myocardial cells with Ang II (1 micromol/L) for 5 min, the p-ERK1/2 protein expression was increased, with the most obvious effect shown at about 10 min; pretreatment of myocardial cells with STS at different doses (2, 10, 50 micromol/L) for 30 min resulted in obvious inhibition of the expression of p-ERK1/2 stimulated by Ang II in a dose-dependent manner. (3) After the myocardial cells were stimulated by Ang II (1 micromol/L), the immunofluorescence of ERK1/2 rapidly appeared in the nucleus. The activation and translocation process of ERK1/2 induced by Ang II was blocked distinctly by STS.

CONCLUSIONSTS inhibited the myocardial cell hypertrophy induced by Ang II, and the mechanism may be associated with the inhibition of p-ERK1/2 expression.

Angiotensin II ; pharmacology ; Animals ; Hypertrophy ; Leucine ; metabolism ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocytes, Cardiac ; drug effects ; enzymology ; pathology ; Phenanthrenes ; pharmacology ; Phosphorylation ; drug effects ; Protein Biosynthesis ; drug effects ; Protein Transport ; drug effects ; Rats ; Rats, Wistar ; Tritium