OBJECTIVE: To investigate the protective effect of fucoxanthin (FX) against diabetic cardiomyopathy and explore the underlying mechanism. METHODS: Rat models of diabetes mellitus (DM) induced by intraperitoneal injection of streptozotocin (60 mg/kg) were randomized into DM model group, fucoxanthin treatment (DM+FX) group and metformin treatment (DM+ Met) group, and normal rats with normal feeding served as the control group. In the two treatment groups, fucoxanthin and metformin were administered after modeling by gavage at the daily dose of 200 mg/kg and 230 mg/kg, respectively for 12 weeks, and the rats in the DM model group were given saline only. HE staining was used to examine the area of cardiac myocyte hypertrophy in each group. The expression levels of fibrotic proteins TGF-β1 and FN proteins in rat hearts were detected with Western blotting. In the cell experiment, the effect of 1 μmol/L FX on H9C2 cell hypertrophy induced by exposure to high glucose (HG, 45 mmol/L) was evaluated using FITC-labeled phalloidin. The mRNA expression levels of the hypertrophic factors ANP, BNP and β-MHC in H9C2 cells were detected using qRT-PCR. The protein expressions of Nrf2, Keap1, HO-1 and SOD1 proteins in rat heart tissues and H9C2 cells were determined using Western blotting. The DCFH-DA probe was used to detect the intracellular production of reactive oxygen species (ROS). RESULTS: In the diabetic rats, fucoxanthin treatment obviously alleviated cardiomyocyte hypertrophy and myocardial fibrosis, increased the protein expressions of Nrf2 and HO-1, and decreased the protein expressions of Keap1 in the heart tissue (P < 0.05). In H9C2 cells with HG exposure, fucoxanthin significantly inhibited the enlargement of cell surface area, lowered the mRNA expression levels of ANP, BNP and β-MHC (P < 0.05), promoted Nrf2 translocation from the cytoplasm to the nucleus, and up-regulated the protein expressions its downstream targets SOD1 and HO-1 (P < 0.05) to enhance cellular antioxidant capacity and reduce intracellular ROS production. CONCLUSION Fucoxanthin possesses strong inhibitory activities against diabetic cardiomyocyte hypertrophy and myocardial fibrosis and is capable of up-regulating Nrf2 signaling to promote the expression of its downstream antioxidant proteins SOD1 and HO-1 to reduce the level of ROS.
Animals ; Antioxidants/metabolism* ; Atrial Natriuretic Factor/pharmacology* ; Cardiomegaly ; Diabetes Mellitus, Experimental/metabolism* ; Fibrosis ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Metformin ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; RNA, Messenger/metabolism* ; Rats ; Reactive Oxygen Species/metabolism* ; Superoxide Dismutase-1/pharmacology* ; Xanthophylls

This paper was aimed to investigate the inhibitory effect of aconitine(AC) on angiotensin Ⅱ(Ang Ⅱ)-induced H9 c2 cell hypertrophy and explore its mechanism of action. The model of hypertrophy was induced by Ang Ⅱ(1×10-6 mol·L-1),and cardiomyocytes were incubated with different concentrations of AC. Western blot was used to quantify the protein expression levels of atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP),β-myosin heavy chain(β-MHC),and α-smooth muscle actin(α-SMA). Real-time quantitative PCR(qRT-PCR) was used to quantify the mRNA expression levels of cardiac hypertrophic markers ANP,BNP and β-MHC. In addition,the fluorescence intensity of the F-actin marker,an important component of myofibrils,was detected by using laser confocal microscope. AC could significantly reverse the increase of total protein content in H9 c2 cells induced by Ang Ⅱ; qRT-PCR results showed that AC could significantly inhibit the ANP,BNP and β-MHC mRNA up-regulation induced by AngⅡ. Western blot results showed that AC could significantly inhibit the ANP,BNP and β-MHC protein up-regulation induced by AngⅡ. In addition,F-actin expression induced by Ang Ⅱ could be inhibited by AC,and multiple indicators of cardiomyocyte hypertrophy induced by Ang Ⅱ could be down-regulated,indicating that AC may inhibit cardiac hypertrophy by inhibiting the expression of hypertrophic factors,providing new clues for exploring the cardiovascular protection of AC.
Aconitine ; pharmacology ; Actins ; metabolism ; Angiotensin II ; Atrial Natriuretic Factor ; metabolism ; Cardiac Myosins ; metabolism ; Cardiomegaly ; Cells, Cultured ; Humans ; Hypertrophy ; Myocytes, Cardiac ; drug effects ; Myosin Heavy Chains ; metabolism ; Natriuretic Peptide, Brain ; metabolism

OBJECTIVETo investigate the effects of evodiamine (Evo), a component of Evodiaminedia rutaecarpa (Juss.) Benth, on cardiomyocyte hypertrophy induced by angiotensin II (Ang II) and further explore the potential mechanisms.

METHODSCardiomyocytes from neonatal Sprague Dawley rats were isolated and characterized, and then the cadiomyocyte cultures were randomly divided into control, model (Ang II 0.1 μmol/L), and Evo (0.03, 0.3, 3 μmol/L) groups. The cardiomyocyte surface area, protein level, intracellular free calcium ([Ca]) concentration, activity of nitric oxide synthase (NOS) and content of nitric oxide (NO) were measured, respectively. The mRNA expressions of atrial natriuretic factor (ANF), calcineurin (CaN), extracellular signal-regulated kinase-2 (ERK-2), and endothelial nitric oxide synthase (eNOS) of cardiomyocytes were analyzed by real-time reverse transcriptionpolymerase chain reaction. The protein expressions of calcineurin catalytic subunit (CnA) and mitogen-activated protein kinase phosphatase-1 (MKP-1) were detected by Western blot analysis.

RESULTSCompared with the control group, Ang II induced cardiomyocytes hypertrophy, as evidenced by increased cardiomyocyte surface area, protein content, and ANF mRNA expression; increased intracellular free calcium ([Ca]) concentration and expressions of CaN mRNA, CnA protein, and ERK-2 mRNA, but decreased MKP-1 protein expression (P<0.05 or P<0.01). Compared with Ang II, Evo (0.3, 3 μmol/L) significantly attenuated Ang II-induced cardiomyocyte hypertrophy, decreased the [Ca] concentration and expressions of CaN mRNA, CnA protein, and ERK-2 mRNA, but increased MKP-1 protein expression (P<0.05 or P<0.01). Most interestingly, Evo increased the NOS activity and NO production, and upregulated the eNOS mRNA expression (P<0.05).

CONCLUSIONEvo signifificantly attenuated Ang II-induced cardiomyocyte hypertrophy, and this effect was partly due to promotion of NO production, reduction of [Ca]i concentration, and inhibition of CaN and ERK-2 signal transduction pathways.

Angiotensin II ; Animals ; Atrial Natriuretic Factor ; metabolism ; Calcineurin ; genetics ; metabolism ; Calcium ; metabolism ; Dual Specificity Phosphatase 1 ; genetics ; metabolism ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Hypertrophy ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Quinazolines ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley

OBJECTIVEEndogenous hydrogen sulfide (H2S), a novel gasotransmitter in cardiovascular regulation, plays an important protective role in the development and progression of atherosclerosis (AS). This study was designed to explore the effects of H2S donor on the production of adrenomedullin (ADM) and atrial natriuretic peptide (ANP) in AS rats.

METHODSMale Sprague-Dawley rats were randomly divided into control group (n=10), AS group (n=10), and AS+NaHS group (n=10). Rats in the AS and AS+NaHS groups were given 3-day intraperitoneal injections of vitamin D3 and 8-week high-fat diet to induce AS, and the rats in the AS+NaHS group were intraperitoneally injected with H2S donor NaHS. Oil red O staining was applied to detect changes in the areas of the atherosclerotic plaques in the aortic root and the coronary artery; sulfide-sensitive electrode method was used to measure the plasma concentration of H2S. ADM and ANP levels in plasma were determined by radioimmunoassay.

RESULTSCompared with the control group, marked atherosclerotic plaques were observed in the aortic root and the coronary artery in AS rats. Moreover, plasma H2S level decreased significantly, ADM level increased, and ANP level decreased significantly in AS rats (P<0.01). However, after the treatment with H2S donor NaHS for 8 weeks, the above changes in AS rats were reversed, demonstrated by significantly reduced areas of the atherosclerotic plaques in both the aortic root and the coronary artery, significantly increased plasma H2S level, significantly decreased plasma ADM level, and significantly increased plasma ANP level (P<0.01).

CONCLUSIONSH2S plays an important regulatory effect on vasoactive peptides ADM and ANP in AS rats.

Adrenomedullin ; biosynthesis ; Animals ; Atherosclerosis ; metabolism ; pathology ; Atrial Natriuretic Factor ; biosynthesis ; Hydrogen Sulfide ; pharmacology ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effect of peroxisiome proliferator activated receptor-α (PPAR-α) on the regulation of cardiomyocyte hypertrophy and the relationship between the effect of PPAR-α with PI3K/Akt//mTOR signal pathway.

METHODSCardiomyocyte hypertrophy was induced by isoproterenol (ISO). The cell surface area was measured by image analysis system (Leica). The expressions of atrial natriuretic peptide (ANP), β-myosin heavy chain (β-MHC) and PPAR-α mRNA were detected by qRT-PCR. The protein expressions of Akt, mTOR and P70S6K were detected by Western blot. The expression of PPAR-α was suppressed by RNAi.

RESULTS(1) The expression of PPAR-α was significantly reduced in cardiomyocyte hypertrophy. PPAR-α activator Fenofibrate (Feno) increased the expression of PPAR-α and suppressed cardiomyocyte hypertrophy. The inhibitory effect of Feno on cardiomyocyte hypertrophy was reversed by PPAR-α RNAi. (2) Feno significantly inhibited the increase of the protein expressions of p-Akt, p-mTOR and p-p70S6K in ISO induced cardiomyocyte hypertrophy, which could be blocked by PPAR-α RNAi. (3) PI3K antagonist LY294002 (LY) or mTOR antagonist rapamycin (RAPA) markedly-inhibited cardiomyocyte hypertrophy. The inhibitory effects of LY or RAPA on cardiomyocyte hypertrophy were reversed by PPAR-α RNAi.

CONCLUSIONPPAR-α can negatively regulate cardiomyocyte hypertrophy. The effect might be associated with PPAR-α inhiting PI3K/ Akt/mTOR signal pathway.

Atrial Natriuretic Factor ; metabolism ; Cardiomegaly ; metabolism ; Cells, Cultured ; Fenofibrate ; pharmacology ; Humans ; Isoproterenol ; adverse effects ; Myocytes, Cardiac ; drug effects ; metabolism ; Myosin Heavy Chains ; metabolism ; PPAR alpha ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Signal Transduction ; TOR Serine-Threonine Kinases ; metabolism

OBJECTIVETo investigate the effect of estrogen on cell proliferation and expression of proteins of C-type natriuretic peptide (CNP), natriuretic peptides B receptor (NPR-B) and natriuretic peptides C receptor (NPR-C) in ATDC5 cells during chondrogenesis.

METHODATDC5 cells were induced for differentiation with insulin 10 µg/ml (day 0), and were started to be investigated on day 6. They were incubated with: (1) Estradiol (E2) at different concentrations (10(-11)-10(-5) mol/L) for 24 hours (for studying cell proliferation), or for 48 hours (for studying CNP, NPR-B and NPR-C protein expression); (2) E2 (10(-8) mol/L) for 24, 48, 72, 96 and 120 h (for studying cell proliferation), or for 24, 48, 72 and 96 hours (for studying CNP, NPR-B and NPR-C protein expression); (3) E2 (10(-8) mol/L) , and/or ICI 182782 (estrogen receptor antagonist ) (10(-7) mol/L) for 24 hours (for studying cell proliferation). ATDC5 cells proliferation were determined by MTT (OD value). Western-blotting was performed to identify the protein levels of CNP, NPR-B and NPR-C.

RESULT(1) After incubation with E2 (10(-11)-10(-5) mol/L) for 24 h, ATD5 cell number increased with the increasing E2 concentration, peak in E2 concentrations of 10(-9) and 10(-8) mol/L (0.56 ± 0.06 and 0.52 ± 0.02, P < 0.05 and <0.01, respectively) , while significantly decreased in E2 (10(-5) mol/L) (0.30 ± 0.02) compared with DMSO-control (0.38 ± 0.02) (P < 0.05). After incubation with E2 (10(-11)-10(-5) mol/L) for 48 h, the protein level of CNP, NPR-B and NPR-C increased significantly, with the greatest effect seen at a concentration of 10(-10) mol/L E2 for CNP and NPR-B, 10(-9) mol/L E2 for NPR-C (P < 0.05). (2) After incubation with E2 (10(-8) mol/L) for 24 to 96 hours: (1) The cell number in each of the four time points was significantly increased compared with DMSO-control, with the greatest effect in 48 h (0.030 ± 0.003) (P < 0.05 or <0.01, respectively). While the cell number at 120 h was similar to that in DMSO-control. (2) The protein level of CNP increased significantly at 24 h (P < 0.05), seemed to be increased at 48 h and 72 h and decreased at 96 h. Both NPR-B and NPR-C level seemed to be increased at 24 h (P = 0.060 and 0.055, respectively) and seemed to decrease at 48 h, with decreasing significantly at both 72 h and 96 h (P < 0.05). (3) After incubation for 24 h, there was significant difference among the cell number of the four groups (P < 0.05). Cell number of group E2 (0.470 ± 0.032) was increased compared with group (E2+ICI) (0.410 ± 0.018), both being increased compared with group DMSO-control (0.370 ± 0.011, P < 0.05, respectively). There was no difference in cell number between group ICI 182782(0.360 ± 0.035) and group DMSO-control.

CONCLUSIONE2 promotes the proliferation of ATDC5 cells i.e. chondrogenesis via estrogen receptor mediated mechanism, in both concentration-dependent and time-dependent manner. E2 (10(-11)-10(-8) mol/L) up-regulates protein expression of CNP, NPR-B and NPR-C of ATDC5 cells during chondrogenesis, and regulate the expression of the three proteins mentioned above positively or negatively at different time point, which implied that estrogen is one of the regulators of CNP signaling pathway.

Animals ; Blotting, Western ; Cell Differentiation ; drug effects ; Cell Line ; Cell Proliferation ; drug effects ; Chondrogenesis ; Dose-Response Relationship, Drug ; Estradiol ; pharmacology ; Gene Expression Regulation ; drug effects ; Mice ; Natriuretic Peptide, C-Type ; metabolism ; Receptors, Atrial Natriuretic Factor ; metabolism ; Signal Transduction ; drug effects ; Time Factors

OBJECTIVETo investigate the expression of C-type natriuretic peptides (CNP) and natriuretic peptide receptor-B (NPR-B) receptor in diabetic rats renal cortex, and the regulation by Tongluo Recipe (TLR).

METHODSSixty male SD rats were divided into 3 groups: the normal control group, diabetic model group and diabetic TLR group. Each group was further divided into two subgroups of ten in each, according to 4-week or 12-week observation period. Streptozotocin (STZ)-induced diabetic rats were treated with TLR (1.0 g·kg(-1)·d(-1)) for 4 and 12 weeks, respectively. (1) The essential information was collected for comparing renal mass, serum creatinine and 24 h urine albumen on each group was calculated. (2) CNP mRNA and NPR-B mRNA were detected by realtime-polymerase chain reaction (PCR) on rats renal cortex. (3) Concentration of CNP on renal cortex or serum were analyzed by enzyme-linked immunosorbent assay (ELISA). (4) Pathological evaluation and NPR-B immunostaining for renal tissue were also performed.

RESULTS(1) CNP and NPR-B mRNA levels were detected in each treated or untreated group, with slight elevated in untreated diabetes rats administrated with STZ after 4-week and CNP mRNA level remarkable elevated at 39.21 times higher than normal control group after 12 weeks, but NPR-B mRNA level showed a remarkably down-regulation at 98.07% after 12 weeks. CNP mRNA of TLR-treated group was also elevated after 12-week treatment, but less than untreated group. (2) Concentrations of CNP in renal cortex were obviously increased in treated or untreated diabetes rats, within these groups the treatment of TLR was found more significantly on prompting CNP concentration. Comparing to normal group, serum concentrations of CNP were also increased in treated or untreated diabetic groups, but there was no difference between these diabetic groups. (3) Renal lesions like glomerular volume increased are observed mostly in the relative early stage after 4 weeks. Although TLR treated group had no significant difference in their glomerular volume, the degrees of injury of glomerulus were ameliorated, as well as the NPR-B immunostaining enhanced in glomerulus. Weakly positive immunostaining of NPR-B are observed in glomerulus of normal control, and negative in glomerulus of untreated diabetes rats administrated with STZ after 12 weeks, whereas TLR-treatment groups showed a little enhancement.

CONCLUSIONCNP and NPR-B showed different characteristic on renal cortex at different pathological period in diabetes rats, and TLR regulated their expression.

Animals ; Body Weight ; drug effects ; Diabetes Mellitus, Experimental ; complications ; drug therapy ; genetics ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Gene Expression Regulation ; drug effects ; Hematuria ; complications ; genetics ; pathology ; Immunohistochemistry ; Kidney ; drug effects ; metabolism ; pathology ; Kidney Cortex ; drug effects ; metabolism ; pathology ; Kidney Glomerulus ; drug effects ; metabolism ; pathology ; Male ; Natriuretic Peptide, C-Type ; genetics ; metabolism ; Organ Size ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Atrial Natriuretic Factor ; genetics ; metabolism ; Staining and Labeling ; Streptozocin

Cinnamyl alcohol (CAL) is known as an antipyretic, and a recent study showed its vasodilatory activity without explaining the mechanism. Here we demonstrate the vasodilatory effect and the mechanism of action of CAL in rat thoracic aorta. The change of tension in aortic strips treated with CAL was measured in an organ bath system. In addition, vascular strips or human umbilical vein endothelial cells (HUVECs) were used for biochemical experiments such as Western blot and nitrite and cyclic guanosine monophosphate (cGMP) measurements. CAL attenuated the vasoconstriction of phenylephrine (PE, 1 microM)-precontracted aortic strips in an endothelium-dependent manner. CAL-induced vasorelaxation was inhibited by pretreatment with NG-nitro-L-arginine methyl ester (L-NAME; 10(-4) M), methylene blue (MB; 10(-5) M) and 1 H-[1,2,4]-oxadiazolole-[4,3-a] quinoxalin-10one, (ODQ; 10(-6) or 10(-7) M) in the endothelium-intact aortic strips. Atrial natriuretic peptide (ANP; 10(-8) or 10(-9) M) did not affect the vasodilatory effect of CAL. The phosphorylation of endothelial nitric oxide synthase (eNOS) and generation of nitric oxide (NO) were stimulated by CAL treatment in HUVECs and inhibited by treatment with L-NAME. In addition, cGMP and PKG1 activation in aortic strips treated with CAL were also significantly inhibited by L-NAME. Furthermore, CAL relaxed Rho-kinase activator calpeptin-precontracted aortic strips, and the vasodilatory effect of CAL was inhibited by the ATP-sensitive K+ channel inhibitor glibenclamide (Gli; 10(-5) M) and the voltage-dependent K+ channel inhibitor 4-aminopyridine (4-AP; 2 x 10(-4) M). These results suggest that CAL induces vasorelaxation by activating K+ channels via the NO-cGMP-PKG pathway and the inhibition of Rho-kinase.
Animals ; Aorta/drug effects/metabolism/physiology ; Atrial Natriuretic Factor/pharmacology ; Cyclic GMP/*metabolism ; Cyclic GMP-Dependent Protein Kinases/*metabolism ; Dipeptides/pharmacology ; Human Umbilical Vein Endothelial Cells/drug effects/metabolism ; Humans ; Male ; Methylene Blue/pharmacology ; NG-Nitroarginine Methyl Ester/pharmacology ; Nitric Oxide/*metabolism ; Nitric Oxide Synthase/metabolism ; Oxadiazoles/pharmacology ; Phenylephrine/pharmacology ; Phosphorylation ; Potassium Channel Blockers/pharmacology ; Potassium Channels/*agonists ; Propanols/*pharmacology ; Quinoxalines/pharmacology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Vasoconstriction/*drug effects ; Vasodilation/drug effects ; rho-Associated Kinases/antagonists & inhibitors/*metabolism

OBJECTIVETo study the effect of Qianyang Recipe (QYR) on the Gan-yang hyperactivity syndrome (GYHS), the blood pressure, and correlated vascular regulatory factors of hypertension rat.

METHODSThirty SD rats were randomly divided into the normal control group, the model group, and the QYR group, ten in each. Hypertension rat model of GYHS was prepared using Aconiti Praeparata Decoction plus ephedrine plus salt water. Rats in the QYR group orally took QYR physic liquor, while distilled water was given to rats in the normal control group and the model group. They were medicated for 28 successive days. The facial temperature, the grip strength, and the systolic pressure were determined once every 7 days. Rats' irritable degree and feather color were observed and recorded once every 14 days. After the last administration the plasma renin (PR), angiotensin II (Ang II), aldosterone (ALD), atrial natriuretic peptide (ANP), calcitonin gene-related peptide (cGRP) were determined.

RESULTSCompared with the model group of the same phase, the facial temperature of rats in the QYR group significantly decreased on the 14th, 21th and 28th day after administration. The systolic pressure obviously decreased on the 21st day after administration. On the 28th day after administration symptoms such as irritability, dry hair were improved, and the Ang II level decreased. There was significant difference in all these changes (P<0.05, P<0.01).

CONCLUSIONSQYR could relieve GYHS rats' symptoms such as facial hotness, irritability, dry hair, and so on, and decrease the systolic pressure. Decreased Ang II level might be one of its mechanisms.

Aldosterone ; blood ; Angiotensin II ; blood ; Animals ; Atrial Natriuretic Factor ; blood ; Calcitonin Gene-Related Peptide ; blood ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hypertension ; blood ; diagnosis ; Male ; Medicine, Chinese Traditional ; Rats ; Rats, Sprague-Dawley ; Renin ; blood

Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y4 receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y4 receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y2 receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y1, 2, 5 receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y3 receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y2 receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y4 and Y2 receptor differently regulate the release of atrial ANP.
Animals ; Arginine/analogs & derivatives/pharmacology ; Atrial Natriuretic Factor/*metabolism ; Benzazepines/pharmacology ; Gene Expression Regulation ; Pancreatic Polypeptide/pharmacology ; Peptide YY/pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Neuropeptide Y/agonists/antagonists & inhibitors/*metabolism