The role of uncoupling protein 2 in the apoptosis induced by free fatty acid in rat cardiomyocytes.

The apoptotic loss of cardiomyocytes contributes to numerous cardiovascular disorders. Evidence suggests that free fatty acids induce cellular apoptosis, and recent studies have shown that free fatty acids dramatically elevate mRNA levels of uncoupling protein 2 (UCP2) in some cell lines. In this study, we investigated the possibility that free fatty acids induce the expression of UCP2 through the peroxisome proliferator-activated receptor pathway, thereby increasing cell apoptosis in adult rat cardiomyocytes. Primary cultured adult rat cardiomyocytes exposed to free fatty acids exhibited a dose-dependent increase in apoptosis. Quantitative real-time reverse transcription-polymerase chain reaction and Western blotting showed significant increases in the level of UCP2 expression at 6, 12, and at 24 hours after treatment of adult rat cardiomyocytes with free fatty acids. Expression of UCP2 was suppressed with RNA interference, and knockdown of UCP2 attenuated free fatty acid-induced apoptosis in the cardiomyocytes. In summary, free fatty acids induced UCP2 expression through peroxisome proliferator-activated receptor alpha in adult rat cardiomyocytes.

Activation of transient receptor potential vanilloid type-1 channel prevents adipogenesis and obesity.

We tested the hypothesis that activation of transient receptor potential vanilloid type-1 (TRPV1) by capsaicin prevents adipogenesis. TRPV1 channels in 3T3-L1-preadipocytes and visceral adipose tissue from mice and humans were detected by immunoblotting and quantitative real-time RT-PCR. The effect of TRPV1 on cytosolic calcium was determined fluorometrically in 3T3-L1-preadipocytes and in human visceral fat tissue. Adipogenesis in stimulated 3T3-L1-preadipocytes was determined by oil red O-staining of intracellular lipid droplets, triglyceride levels, expression of peroxisome proliferator-activated receptor-gamma, and expression of fatty acid synthase. Long-term feeding experiments were undertaken in wild-type mice and TRPV1 knockout mice. We detected TRPV1 channels in 3T3-L1-preadipocytes and visceral adipose tissue from mice and humans. In vitro, the TRPV1 agonist capsaicin dose-dependently induced calcium influx and prevented the adipogenesis in stimulated 3T3-L1-preadipocytes. RNA interference knockdown of TRPV1 in 3T3-L1-preadipocytes attenuated capsaicin-induced calcium influx, and adipogenesis in stimulated 3T3-L1-preadipocytes was no longer prevented. During regular adipogenesis TRPV1 channels were downregulated which was accompanied by a significant and time-dependent reduction of calcium influx. Compared with lean counterparts in visceral adipose tissue from obese db/db and ob/ob mice, and from obese human male subjects we observed a reduced TRVP1 expression. The reduced TRPV1 expression in visceral adipose tissue from obese humans was accompanied by reduced capsaicin-induced calcium influx. The oral administration of capsaicin for 120 days prevented obesity in male wild type mice but not in TRPV1 knockout mice assigned to high fat diet. We conclude that the activation of TRPV1 channels by capsaicin prevented adipogenesis and obesity.

[The relationship between uncoupling protein 2 expression and myocardial high energy phosphates content in abdominal aorta constriction induced heart failure rats].

OBJECTIVE: To explore the changes of expression of uncoupling protein 2 (UCP2) in pressure overload induced failure myocardium in rats. METHODS: Male SD rats were randomized into 3 groups (n = 15 each): abdominal aorta constriction (AC) 20 weeks group (H20w group), sham operation group (SH20w group) and normal control group (N group). Twenty weeks later, myocardial function was evaluated by echocardiography and hemodynamic measurements. Mitochondria in ventricular tissue were isolated by centrifugation. Adenine nucleotide pools (ATP, ADP, AMP, PCr) in myocardium were measured by high performance liquid chromatography. The expression of UCP2 in mitochondria was detected by PT-PCR and Western blot analysis. RESULTS: Myocardial function was significantly decreased 20 weeks post-AC compared to SH20w group and N group. Myocardial ATP, ADP, AMP and PCr contents were also significantly decreased in H20w group than the other 2 control groups. The expression of UCP2 in myocardial mitochondria was significantly increased in H20w group and negatively correlated with ATP contents (r = -0.929, P < 0.01). CONCLUSIONS: The expression of UCP2 was upregulated in pressure overload induced failure heart and might be responsible for decreased myocardial adenine nucleotide and energy metabolism disturbance in this model.

[Autologous mesenchymal stem cell implantation promotes myocardial expressions of growth factors and improves cardiac function in failing rat hearts].

OBJECTIVE: To explore the underlying mechanism of mesenchymal stem cells (MSCs) transfer induced cardiac function improvement in failing hearts. METHODS: Congestive heart failure (CHF) was induced in rats by cauterization of the heart wall. MSCs were cultured from autologous bone marrow and injected into the border zone and the remote myocardium 5 days after cauterization. RESULTS: Ten weeks later, cardiomyocyte nucleus mitotic index, capillary density and expression of insulin-like growth factor 1 (IGF-1), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) were significantly increased in the border zone and significantly reduced in the remote myocardium in CHF rats (all P<0.05 vs. sham). Besides cardiac function improvement and left ventricular remodeling attenuation evidenced by hemodynamic and echocardiographic examinations, expressions of IGF-1, HGF and VEGF in the remote myocardium and in the border zone were also significantly upregulated (P<0.05 or P<0.01 vs. CHF), and cardiomyocyte nucleus mitotic index as well as capillary density were significantly increased in CHF rats with MSCs (P<0.05 or P<0.01 vs. CHF). Moreover, collagen area was significantly reduced and myocardial area was significantly increased in the border zone in these rats too. CONCLUSION: Autologous MSC implantation upregulated expressions of growth factors enhanced cardioangiogenesis which might be the underlying mechanisms for improved cardiac function and attenuated left ventricular remodeling induced by MSCs transplantation in failing rat myocardium.

[Metabolic remodeling and the alteration of related receptors expressions in failing heart].

OBJECTIVE: To explore the metabolic remodeling and its correlative mechanisms in human failing heart by contrasting the content of substrate, the activity of correlative enzyme and the mRNA and protein expression of beta(3)-adrenoceptor and peroxisome proliferator-activate receptor alpha (PPARalpha). METHODS: Cardo ac tossie samples were talem from 20 patients with heart failure of valvular heart disease and undergoing valvuloplasty operation as well as 6 subjects being killed in accidents (as control). The levels of free fat acid (FFA) and the activity of succinate dehydrogenase (SDH), Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase of the myocardial tissue were measured. Protein and mRNA expression of beta(3)-adrenergic receptor and peroxisome proliferator-activated receptor alpha (PPARalpha) in myocardial tissue were analyzed using reverse transcriptase-polymerase chain reaction and Western-blot respectively. RESULTS: In the failing hearts, the contents of FA and expression of beta 3 adrenoceptor mRNA and protein were obviously higher than those in the control group, the activity of SDH, Na(+)-K(+)-ATPase, Ca(2+)-Mg(2+)-ATPase and expression of PPARalpha mRNA and protein were on the contrary. CONCLUSION: The human failing myocardium is characterized by metabolic remodeling and it maybe concerned with the upregulation of beta3 adrenoceptor and downregulation of PPARalpha.

[Expressions of beta(3)-adrenoceptor and peroxisome proliferator-activated receptor alpha in human failing heart].

OBJECTIVE: To explore the changes on the content of substrate, the activity of correlative enzyme and the mRNA and protein expressions of beta(3)-adrenoceptor and peroxisome proliferator-activated receptor alpha (PPARalpha) in human failing heart. METHOD: Papillary muscles from 20 patients with heart failure during mitral valves replacement and 6 control subjects died of non-cardiac accidents were obtained and free fat acid (FFA), lactic acid (LD) and the activity of Na(+)K(+)-ATPase and Ca(2+)Mg(2+)-ATPase, protein and mRNA expressions of beta(3)-adrenergic receptor and PPARalpha were measured. RESULT: In the failing heart, the contents of fat acid, LD and expression of beta(3)-adrenoceptor mRNA and protein were significantly higher while the activity of Na(+)K(+)-ATPase and Ca(2+)Mg(2+)-ATPase, expressions of PPARalpha at mRNA and protein levels were significantly lower than those in control myocardium. CONCLUSION: Metabolic remodeling (upregulation of beta(3)-adrenoceptor and downregulation of PPARalpha) might contribute to the pathophysiology of heart failure.

[Angiotensin II induced cardiac hypertrophy is blocked by PTEN via suppressing Ca2+/Calcineurin pathway].

OBJECTIVE: To investigate the effects of PTEN on Ang II induced cardiomyocyte hypertrophy and subsequent Ca(2+)/Calcineurin pathway changes. METHODS: Primary cultured neonatal rat cardiomyocytes were cultured and were treated with phosphate-buffered saline, empty adenovirus (Ad-GFP), or adenovirus encoding for PTEN (Ad-PTEN-GFP) for 48 h and Ang II (10(-7) mol/L) was added to the medium for another 24 h. Cells were harvested and intracellular Ca(2+) concentration ([Ca(2+)] i) was determined by Fura-2/AM ratio imaging analysis; PTEN, ANF, beta-MHC and CaNAbeta mRNA evaluated with RT-PCR; PTEN and CaNAbeta protein by Western blot; CaN phosphatase activity by CaN detecting kits. RESULTS: PTEN at mRNA and protein levels were significantly higher in Ad-PTEN-GFP treated cardiomyocytes than that of Ad-GFP treated cardiomyocytes. Ang II stimulation upregulated [Ca(2+)] i, CaNAbeta at mRNA and protein levels and CaN phosphatase activity in Ad-GFP treated cardiomyocytes but not in Ad-PTEN-GFP treated cardiomyocytes. CONCLUSIONS: Cardiac hypertrophy induced by Ang II could be blocked by PTEN overexpression via suppressing Ca(2+)/Calcineurin pathway.

[Beneficial effects of probucol on endothelial function in patients with acute coronary syndrome].

OBJECTIVE: The study investigate the antioxidant probucol on endothelial function in patients with acute coronary syndrome (ACS). METHODS: A total of 49 ACS patients randomly received standard therapy plus probucol (P, n = 24) or standard therapy (C, n = 25). Plasma oxidized low-density lipoprotein (ox-LDL), nitric oxide (NO) and circulating endothelial cells (CEC) were measured. The brachial arterial hyperemia-induced flow mediated dilation (FMD) and sublingual nitroglycerin (NTG) mediated vasodilatations were measured by high resolution ultrasound. These variables were analyzed before and after 3 months therapy. RESULTS: Plasma NO and FMD was significantly increased after 3 months therapy than before therapy [(80.46 +/- 10.24) micromol/Lvs (48.46 +/- 12.24) micromol/L, P < 0.01; (13.46 +/- 1.20)% vs (7.45 +/- 1.02)%, P < 0.05, respectively], while the number of CEC and ox-LDL were significantly decreased (P < 0.01) in P group. These values were similar before and after 3 months in C group. The linear correlation analysis showed that plasma ox-LDL negatively correlated with NO (r = -0.574, P < 0.01) and FMD (r = -0.517, P < 0.01) and positively correlated with CEC (r = 0.385, P < 0.01) in patients received 3 months probucol therapy. CONCLUSIONS: Chronic antioxidant probucol therapy could improve endothelial function in patients with ACS.

Effect of Phosphatase and Tensin Homologue on Chromosome 10 on Angiotensin II-Mediated Proliferation, Collagen Synthesis, and Akt/P27 Signaling in Neonatal Rat Cardiac Fibroblasts.

Cardiac fibroblasts (CFs) play a key role in cardiac fibrosis by regulating the balance between extracellular matrix synthesis and breakdown. Although phosphatase and tensin homologue on chromosome 10 (PTEN) has been found to play an important role in cardiovascular disease, it is not clear whether PTEN is involved in functional regulation of CFs. In the present study, PTEN was overexpressed in neonatal rat CFs via recombinant adenovirus-mediated gene transfer. The effects of PTEN overexpression on cell-cycle progression and angiotensin II- (Ang II-) mediated regulation of collagen metabolism, synthesis of matrix metalloproteinases, and Akt/P27 signaling were investigated. Compared with uninfected cells and cells infected with green fluorescent protein-expressing adenovirus (Ad-GFP), cells infected with PTEN-expressing adenovirus (Ad-PTEN) significantly increased PTEN protein and mRNA levels in CFs (P < 0.05). The proportion of CFs in the G1/S cell-cycle phase was significantly higher for PTEN-overexpressing cells. In addition, Ad-PTEN decreased mRNA expression and the protein synthesis rate of collagen types I and III and antagonized Ang II-induced collagen synthesis. Overexpression of PTEN also decreased Ang II-induced matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) production as well as gelatinase activity. Moreover, Ad-PTEN decreased Akt expression and increased P27 expression independent of Ang II stimulation. These results suggest that PTEN could regulate its functional effects in neonatal rat CFs partially via the Akt/P27 signaling pathway.

[PTEN negatively regulates isoproterenol-induced cardiac hypertrophy and effects of captopril on PTEN expression].

OBJECTIVE: To examine the negative regulation role of PTEN in isoproterenol-induced cardiac hypertrophy by testing the expression of PTEN mRNA and protein and to explore the effects of captopril (Cap) on PTEN expression. METHODS: Twenty four rats were randomly divided into three groups: control group, ISO group, and ISO+Cap group. The following parameters were examined:body weight (BW), heart weight (HW), left ventricular weight (LVW), left ventricular end-diastolic pressure (LVEDP), left ventricular end-systolic pressure (LVESP) and +/- dp/dt(max). The ratio of HW/BW and LVW/BW was calculated. PTEN mRNA and protein were tested by RT-PCR and Western blot, respectively. RESULTS: (1) Compared with the control group, the ratio of HW/BW and LVW/BW, LVEDP and LVESP were all increased in ISO group and ISO+Cap group (P < 0.05), but +/- dp/dt(max) was decreased (P < 0.05); (2) compared with the ISO group, the ratio of HW/BW and LVW/BW, LVEDP, LVESP were all decreased in ISO+Cap group (P < 0.05), but +/- dp/dt(max) was increased (P < 0.05); (3) compared with the control group, PTEN mRNA and protein were up-regulated in ISO group and ISO+Cap group; (4) compared with the ISO group, PTEN mRNA and protein were up-regulated in ISO+Cap group. CONCLUSIONS: PTEN mRNA and protein are up-regulated in isoproterenol-induced cardiac hypertrophy. Captopril can up-regulate PTEN expression in cardiac hypertrophy. There is a negative regulative mechanism in cardiac hypertrophy process, in which PTEN is probably an endogenous negative regulator of cardiac hypertrophy.

[The relationship between expressions of beta1-, beta2-, beta3-adrenoceptor mRNA of myocardium and cardiac function in patients with heart failure].

OBJECTIVE: To investigate the alteration of expressions of beta(1)-, beta(2)-, beta(3)-adrenoceptor mRNA in human myocardial tissue and the relation between their expressions and cardiac function in patient with heart failure. METHODS: The mRNA expressions of beta(1)-, beta(2)- and beta(3)-adrenergic receptors in myocardial tissue were analyzed by using the reverse transcriptase-polymerase chain reaction in 24 patients with heart failure of valvular heart disease and 5 control subjects. RESULTS: Beta(1)-adrenergic receptor mRNA expressions in myocardium were significantly lower in patients with heart failure than those in control subjects, and progressively reduced with aggravation of heart function. By contrast, beta(3)-adrenoceptor mRNA expressions were significantly higher in patients with heart failure than those in controls, and progressively elevated with aggravation of cardiac function. No difference was observed in beta(2)-adrenergic receptor among all groups. CONCLUSION: The changes of beta-adrenergic receptor mRNA expression are associated with the severity of heart failure.

[Relationship between proliferation of vascular smooth muscle cells and PDGF-AA and PDGFR-alpha expression in SHRs].

To explore the role of platelet derived growth factor-AA (PDGF-AA) and PDGFR-alpha expression in the proliferation and hypertrophy of vascular smooth muscle cells (VSMCs) in spontaneously hypertension rats (SHR), protein expression of PDGF-AA, PDGFR-alpha and PDGFR-beta in SHR/Wistar-Kyoto (WKY)-VSMC was observed by Western blot. Proliferation and hypertrophy of SHR-VSMCs induced by PDGF-AA were observed by measurement of PCNA and [(3)H] incorporation. PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMCs compared with that in WKY-VSMCs, but PDGFR-beta was not different in SHR and WKY-VSMCs. PDGF-AA induced PCNA expression and [(3)H] incorporation was increased in a dose-dependent manner in SHR, but not in WKY. It is suggested that an enhancement of PDGF-AA and PDGFR-alpha in SHRs may be one of the important factors for vascular modeling.

[Changes of mitochondrial genes expressed in the brain tissue of rat in stroke-like episodes rats].

OBJECTIVE: Stroke is a complex disorder caused by a combination of genetic and environmental factors. Epidemiological studies have provided evidence of genetic influence on the development of human stroke. However, genetic changes which contribute to the development of stroke are not well known. This study was designed to gain a deep insight into that aspect. METHODS: Using cold-stimuli plus high-salt intake as environmental risk factors, the authors established a hypertension model in rats, which produced a complication of stroke. Then, they used the suppression subtractive hybridization(SSH) technique to identify the differential genes that specifically expressed in total cerebrum tissue of the rats in stroke group. A comparison was made between two populations, namely the control group and stroke group. RESULTS: By the use of SSH approach, a total of 576 clones were generated in this study from two subtractive libraries, among them 456 clones were usable and were analyzed. Genes for metabolism transcripts in stroke group were shown to be up-regulated (P<0.01). Mitochondrial transcripts were observed in a high rate of 26.5%. CONCLUSION: The findings suggested that mitochondrial genes should induce an increased sensitivity to stroke through the changes of gene expressions. Mitochondrial genes probably play important roles in the causes and effects of stroke.

[CaN-NFAT3 signal pathway: a crucial hinge relates Ca2+ signal with cardiomyocyte hypertrophy].

OBJECTIVE: To investigate the role of [Ca2+]i from different origins in the course of myocardial hypertrophy mediated by CaN-NFAT3 signal transduction. METHODS: The primarily cultured cardiomyocyte were irritated with angiotensin (Ang) II and ryanodine (RY) which cause Ca2+ inflow and release respectively. Then to observe the changes of CaN-NFAT3 pathway were then observed. Western blotting was employed to semi-quantify CaN, NFAT3 and GATA4. The distribution of NFAT3 was shown with immunocytochemistry, (3)H-Leu incorporation was used as an index of myocyte hypertrophy. Cyclosporin A (CsA) was applied to restrain CaN-NFAT3 pathway as a kind of CaN-selective antagonist. RESULTS: CaN, NFAT3, GATA4 expression significantly increased 1 and 3 days after the stimulation of cardiomyocytes with Ang II and RY (10(-7) mol/L) as compared with that of a control group (P > 0.05) and (3)H-Leu incorporation distinctly increased after Ang II and RY (10(-7) mol/L) stimulation (P > 0.05 versus control group). On the first day of Ang II and RY stimulation, NFAT3 was shown mainly as intra-nuclear expression rather than cytoplasmic expression as seen in the control group. All of the above effects were suppressed by CsA administration, but they were rarely suppressed if CsA was not administered (P > 0.05). CONCLUSIONS: It is shown that both Ca2+ inflow and release may activate CaN-NFAT3 signal pathway, which responds to increase of [Ca2+]i and is independent of its origin, indicating the augment of [Ca2+]i may trigger CaN-NFAT3 signal transduction and consequently induce myocyte hypertrophy. Moreover, CsA may restrain the expression and activation of CaN-NFAT3 and protein synthesis of myocytes in response to Ang II and RY stimulation.

[Transplantation of exogenous mesenchymal stem cells for treatment of myocardial infarction in rat].

OBJECTIVE: To investigate the possibility of homing,survival, migration and differentiation of rat mesenchymal stem cells (rMSCs) in host myocardium and the effects of rMSCs transplantation on the function of heart with myocardial infarction; To observe the feasibility of using exogenous adult stem cells for cell therapy. METHODS: 35 female rats were separated randomly into three groups: normal control group (control, n = 10), acute myocardial infarction control group (AMI, n = 10) and myocardial infarction plus cell transplantation group (AMI + Cell, n = 15). The infarcted hearts were made by occlusion of left coronary artery. Male Wistar rats MSCs were isolated and purified. Then the cells were implanted into the infarcted hearts of female Wistar rats. Heart functions were measured 10 weeks after implantation. The hearts were harvested 10 weeks after implantation for immunohischemistry. RESULTS: (1) Purified rMSCs survived and homed in exogenous host hearts; (2) DAPI-labelled rMSCs with oval nucleus were widely distributed and stained positively of cardiac specific proteins. The arrangements of the donated cells paralleled with host myocardium fibers in infarcted host hearts. Transplantation of rMSCs was associated with a significant decrease of end left ventricular volumes, increase of left ventricular end-systolic pressure and increase of ratio of left ventricular pressure rise and left ventricular pressure decay (+/- dp/dt) (P < 0.05) as compared with the control hearts. The numbers of blood vessels were increased at the boundary of infarction site and the sizes of infarction were decreased significantly (P < 0.05). CONCLUSIONS: The purified rMSCs can survive in exogenous host hearts without addition of any immunosuppressant. These exogenous cells take part in myocardium regeneration and have beneficial effects on heart function.

[Tumor necrosis factor alpha and myocardial matrix metalloproteinases in left ventricular remodeling].

OBJECTIVE: The cytokine tumor necrosis factor (TNF) alpha has been causally linked to left ventricular (LV) remodeling, but the molecular basis for this effect is unknown. It is essential to study the changes of plasma levels of TNF alpha and matrix metalloproteinase-2,3,9 (MMP-2,3,9) expressions in myocardium during congestive heart failure (CHF). METHODS: Plasma levels of TNF alpha were measured with enzyme-linked immunoassay in CHF patients of various degrees and in healthy controls. Using Western blotting assay, we detected the protein expressions of MMP-2,3,9 on myocardial tissue in CHF patients and in healthy controls. Cardiac function parameters were measured with echocardiographic studies. RESULTS: Plasma levels of TNF alpha increased significantly in patients with CHF (P < 0.05 or < 0.01). The protein expressions of MMP-2,3,9 were significantly higher in patients with CHF than in controls (P < 0.05 or < 0.01). The higher the degree of CHF, the greater the numbers of expressions. No changes of MMP-2 could be found between the controls and CHF patients of NYHA II. There was a positive correlation between plasma levels of TNF alpha and the protein expressions of MMP-2,3,9 (P < 0.01 or < 0.001). CONCLUSIONS: It is suggested that alterations of TNF alpha may stimulate the expressions of MMPs, contribute to myocardial remodeling and lead to the development and progression of congestive heart failure. These changes may induce a direct effect on the progression and deterioration of heart failure.

[Migration and differentiation of exogenous rat mesenchymal stem cells engrafted into normal and injured hearts of rats].

OBJECTIVE: To investigate the effects of different microcircumstances on the migration and differentiation of grafted rat mesenchymal stem cells (rMSC) in host myocardium and the feasibility of treatment of myocardial infarction by exogenous adult stem cells. METHODS: rMSC were isolated from the femurs and tibiae of a male Wistar rat and then purified, made into cell suspension, and labeled with DAPI. 35 female Wistar rat were divided randomly into four groups: acute myocardial infarction control group (AMI group, n = 10, the descending anterior branch of left coronary artery was ligated), acute myocardial infarction + rMSC transplantation group (AMI + rMSC group, n = 10, 1 - 3 hours after the ligation DAPI-labeled rMSC were injected into the peri-infarct tissues), normal heart + rMSC transplantation group (normal heart + MSC group, n = 10, DAPI-labeled rMSC were injected into the corresponding myocardium), and mono-nuclear cells transplantation group (AMI + MNCS, n = 5 DAPI-labeled mononuclear cells were injected into he periinfarct tissues). Ten weeks after the implantation, the rats were killed and their hearts were harvested. Immunohistochemistry was used to examine the troponin, GATA-4 and connexin-43. RESULTS: No lymphocyte proliferation and immonologic rejection were seen in the cardiac tissues of the rats implanted with rMSC. DAPI-labeled rMSC with blue nuclei were distributed extensively in the myocardium of the AMI + rMSC group, ovoid in shape and arranged in parallel with the cardiac muscle fibers, and were distributed sporadically like islands in the myocardium of the normal heart + rMSC group, irregular in shape and not arranged in parallel with the cardiac muscle fibers. No blue nucleus was seen in the cardiac tissues of the hearts implanted with DAPI-labeled mononuclear cells. Troponin and GATA4 were positive immunohistochemically in the implanted rMSC with blue nuclei and the host cardiac muscle cells of the AMI group and AMI + rMSC group, however, were negative in the implanted rMSC with blue nuclei and normal cardiac muscle cells of the normal heart + rMSC group. CONCLUSION: Purified rMSC are immunologically tolerable and can be used as donor cells for exogenous cells therapy. Capable of surviving and homing in both in normal and injured hearts, exogenous rMSC migrate and differentiate into cardiac muscle cell-like cells in myocardium with infarction, however, not in normal heart.

Growth factors induce the improved cardiac remodeling in autologous mesenchymal stem cell-implanted failing rat hearts.

Therapeutically delivered mesenchymal stem cells (MSCs) improve ventricular remodeling. However, the mechanism underlying MSC cardiac remodeling has not been clearly determined. Congestive heart failure (CHF) was induced in rats by cauterization of the left ventricular free wall. MSCs were cultured from autologous bone marrow and injected into the border zone and the remote myocardium 5 d after injury. Ten weeks later, when compared with sham operation, CHF significantly increased nucleus mitotic index, capillary density, and expression of insulin-like growth factor 1, hepatocyte growth factor and vascular endothelial growth factor in the border zone (P<0.01) and decreased each of them in the remote myocardium (P<0.05 or P<0.01). MSC implantation in CHF dramatically elevated expression of these growth factors in the remote myocardium and further elevated their expression in the border zone when compared with CHF without MSC addition (P<0.05 or P<0.01). This was paralleled by a higher nucleus mitotic index and a significantly increased capillary density both in the remote myocardium and in the border zone, and by a lower percentage of area of collagen and a higher percentage of area of myocardium in the border zone (P<0.05 or P<0.01), and cardiac remodeling markedly improved. Autologous MSC implantation promoted expression of growth factors in rat failing myocardium, which might enhance cardiomyogenesis and angiogenesis, and improved cardiac remodeling.

[Effect of PDGF-AA on [Ca2+]i in vascular smooth muscle cells in SHRs].

AIM: To explore the relationship between proliferation and hypertrophy of vascular smooth muscle cells and PDGF-AA and PDGFR-alpha expression in SHRs and the role of [Ca2+]i in it. METHODS: Express difference of PDGF-AA, PDGFR-alpha, PDGFR-beta in SHR/WKY-VSMC was observed by Western blot. The effect of Ca2+ inhibitor (nimodipine) on proliferation, hypertrophy and free Ca2+ concentration of SHR-VSMC induced by PDGF-AA was observed by Western blot, [3H] incorporation and fluorescent digital image technique. RESULTS: PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMC than in WKY-VSMC, but PDGFR-beta was not different in SHR and WKY-VSMC. PDGF-AA-stimulated PCNA expression, [3H] incorporation and [Ca2+]i increasing were observed in SHR-VSMC. Dose-dependent nimodipine-inhibited PCNA expression, [3H] incorporation and [Ca2+]i increasing induced by PDGF-AA also were observed in SHR-VSMC. CONCLUSIONS: Spontaneously expression increasing of PDGF-AA and PDGFR-alpha in spontaneously hypertension rats (SHRs) may be one of the important factors on vascular reactivity and vascular modeling mediated through proliferation and hypertrophy in SHR-VSMC, and [Ca2+]i play an important role in this process.

[Study on the relationship between nitric oxide synthase gene G894T polymorphism and hypertension related risk factors in patients with essential hypertension in Chongqing city].

OBJECTIVE: To explore the relationship between genetic anomaly and risk factors in hypertension, a polymorphism at position G894T of the gene encoding the endothelial nitric oxide synthase (eNOS) together with hypertension related risk factors were observed in patients with essential hypertension (EH) in Chongqing city. METHODS: Two hundred and twenty-six patients with EH and matched controls were selected. Genotypes of polymorphisms were determined by polymerase chain reaction (PCR), while PCR products were digested by restriction endonuclease (BanII). Questionnaire referred to life style, dietary, smoking, alcohol consumption, psychological and mental state, waist-to-hip ratio (WHR), etc was administered. RESULTS: There was no significant difference noticed in genotype distribution for the eNOS gene G894T genotype between hypertensive groups and controls, but difference was found among certain related risk factors, such as salt intake, snoring and WHR, etc. Logistic regression analysis showed no association between 894T allele and hypertension. CONCLUSION: Although the polymorphism of eNOS gene G894T did not seem to play an important and direct role in the pathogenesis of EH it might have indirect effects through certain risk factors.