The Effect on LRP6 via Regulating Canonical Wnt/β-catenin Signaling in Doxorubicin-induced Cardiomyocyte Injury / 中山大学学报(医学科学版)

@#【Objective】To investigate the function of LRP6 and canonical Wnt/β-catenin signaling pathway in Doxorubicin-induced cardiomyopathy.【Methods】To establish the model of Dox cardiomyopathy in vitro and in vivo，H9C2 cells were treated with Dox（1 μmol/L）for 12 h and twelve SD rats were divided into two groups equally，and intraperitoneally injected with normal saline and Dox respectively. The changes of protein and mRNA levels were detected by western blot and qPCR. Cardiomyocytes were transfected with siRNA to knockdown LRP6. Mitochondrial membrane potential，nuclear condensation and matrix swelling were determined by Rhodamine 123 ，Hoechst and Mitotracker staining respectively. The apoptosis rate of cells was measured by flow cytometric analysis. 【Results】 The model of Dox cardiomyopathy was successfully established in vitro and in vivo. Dox downregulated the mRNA and protein levels of LRP6. Knockdown of LRP6 aggravated the cell apoptosis and mitochondrial damage induced by Dox. Both Dox and silencing LRP6 induced the downregulation of β - catenin ，and activation of β - catenin reversed the cardiomyocytes apoptosis caused by Dox. 【Conclusions】 Dox downregulated the expression of LRP6 and inhibited canonical Wnt/β- catenin signaling pathway，thus causing cardiomyocytes apoptosis and mitochondrial dysfunction.

SIRT3:a potential target for CHF? / 中国药理学与毒理学杂志

Pathological cardiac hypertrophy is a maladaptive response in a variety of organic heart disease(OHD),which is characterized by mitochondrial dysfunction that results from disturbed energy metabolism. SIRT3, a mitochondria-localized sirtuin, regulates global mitochondrial lysine acetylation and preserves mitochondrial function. However, the mechanisms by which SIRT3 regulates cardiac hypertrophy remains to be further elucidated. In this study, we firstly demonstrated that expression of SIRT3 was decreased in AngiotensionⅡ(AngⅡ)-treated cardiomyocytes and in hearts of AngⅡ-induced cardiac hypertrophic mice. In addition, SIRT3 overexpression protected myocytes from hypertrophy, whereas SIRT3 silencing exacerbated Ang II-induced cardiomyocyte hypertrophy.In particular,SIRT3-KO mice exhibited significant cardiac hypertrophy. Mechanistically, we identified NMNAT3 (nicotinamide mononucleotide adenylyltransferase 3), the rate-limiting enzyme for mitochondrial NAD biosynthesis, as a new target and binding partner of SIRT3.Specifically,SIRT3 physically interacts with and deacety-lates NMNAT3,thereby enhancing the enzyme activity of NMNAT3 and contributing to SIRT3-mediated anti-hypertrophic effects.Moreover,NMNAT3 regulates the activity of SIRT3 via synthesis of mitochon-dria NAD.Taken together,these findings provide mechanistic insights into the negative regulatory role of SIRT3 in cardiac hypertrophy.Sirtuin 3(SIRT3),a mitochondrial deacetylase that may play an impor-tant role in regulating cardiac function and a potential target for CHF

Effects of short-chain acyl-CoA dehydrogenase on hypertensive vascular remodeling / 中国病理生理杂志

AIM:To investigate the changes of short-chain acyl-CoA dehydrogenase(SCAD)in hypertensive vascular remodeling and to explore the relationship between SCAD and vascular remodeling in hypertension.METHODS:The spontaneously hypertensive rats(SHR;24 weeks old)and Wistar rats(24 weeks old)were used as experimental con-trol groups.The SHR and Wistar rats of 16 weeks old were trained by swimming as experimental groups.The systolic pres-sure was measured periodically.The thickness of vascular wall and the diameter of the vascular lumen were measured.The contents of ROS and ATP,the enzyme activity of SCAD, and the expression of SCAD at mRNA and protein levels in the aorta were determined.The free fatty acid in the serum and aorta was also measured.RESULTS:Compared with Wistar group,the diameter of vascular lumen decreased in SHR group.The thickness of vascular wall,the ratio of vascular wall and the diameter of vascular lumen,and the blood pressure in SHR group were increased significantly(P<0.05).Com-pared with SHR group,the diameter of vascular lumen increased in SHR +swim group.The thickness of vascular wall,the ratio of vascular wall and the diameter of vascular lumen,and the blood pressure in SHR +swim group were decreased sig-nificantly.Compared with control group, the expression of SCAD at mRNA and protein levels, the enzyme activity of SCAD,and the content of ATP were decreased in SHR group.However,the free fatty acid in the serum and aorta,and the content of ROS in the aorta were increased in SHR group.The expression of SCAD at mRNA and protein levels,the en-zyme activity of SCAD,the content of ATP were increased in Wistar +swim group and SHR +swim group.However, the free fatty acid in serum and aorta,and the content of ROS in the aorta were decreased in Wistar +swim group and SHR+swim group.CONCLUSION: Decrease in SCAD expression may be associated with hypertensive vascular remodeling. Swimming training can reverse hypertensive vascular remodeling by increasing the expression of SCAD in the aorta.

Comparative proteomic analysis of differentially expressed proteins between K562 and K562/ADM cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Multidrug resistance to chemotherapeutic agents is an important clinical problem during the treatment of leukemia. The resistance process is multifactorial. To realize the total factors involved in multidrug resistance, we analyzed the differentially expressed proteins of K562 and K562/ADM cells and we investigated one of the up-regulated proteins (CRKL) using siRNA to determine its role in K562/ADM cells.</p><p><b>METHODS</b>Altered protein expressions between K562/S (K562 ADM-sensitive cell line) and K562/ADM (K562 multidrug resistant cell line induced by adriamycin) were identified by 2D-DIGE coupled with mass spectrometry. Meanwhile, we confirmed the differential expression of CRKL and Stathmin in both K562 and K562/ADM cells by Western blot analysis. Furthermore, we used RNA interference to silence the CRKL gene expression.</p><p><b>RESULTS</b>Among the 9 differentially expressed proteins, 3 were up-regulated in K562/ADM cells, while 6 were down-regulated in the K562/ADM cells compared with its parent cell line. The expression of CRKL was up-regulated significantly in K562/ADM cells, and it can be decreased by recombinant lentivirus. Moreover, the multidrug resistance of K562/ADM cells was efficiently reversed by silence of CRKL gene expression.</p><p><b>CONCLUSIONS</b>The data provided the differentially expressed proteins in K562 and its resistant cell line and highlights the power of 2D-DIGE for the discovery of resistance markers in cancer. We found CRKL may be a new protein involved in the multidrug resistance of leukaemia cells.</p>

Berberine ameliorates renal injury in streptozotocin-induced diabetic rats by suppression of both oxidative stress and aldose reductase / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Berberine is one of the main constituents of Coptidis rhizoma (CR) and Cortex phellodendri. In this study, we investigated the beneficial effects of berberine on renal function and its possible mechanisms in rats with diabetic nephropathy (DN).</p><p><b>METHODS</b>Male Wistar rats were divided into three groups: normal, diabetic model, and berberine treatment groups. Rats in the diabetic model and berberine treatment groups were induced to diabetes by intraperitonal injection with streptozotocin (STZ). Glomerular area, glomerular volume, fasting blood glucose (FBG), blood urea nitrogen (BUN), serum creatinine (Cr) and urine protein for 24 hours (UP24h) were measured using commercially available kits. Meanwhile, the activity of superoxide dismutase (SOD), content of malondialdehyde (MDA) in serum, activity of aldose reductase (AR) and the expression of AR mRNA and protein in kidney were detected by different methods.</p><p><b>RESULTS</b>The results showed that oral administration of berberine (200 mg x kg(-1) x d(-1)) significantly ameliorated the ratio of kidney weight to body weight. Glomerular area, glomerular volume, FBG, BUN, Cr and UP24h were significantly decreased in the berberine treatment group compared with the diabetic model group (P < 0.05). Berberine treatment significantly increased serum SOD activity and decreased the content of MDA compared with diabetic model group (P < 0.05). AR activity as well as the expression of AR mRNA and protein in the kidney was markedly decreased in the berberine treatment group compared with diabetic model group (P < 0.05).</p><p><b>CONCLUSION</b>These results suggested that berberine could ameliorate renal dysfunction in DN rats through controlling blood glucose, reduction of oxidative stress and inhibition of the activation of the polyol pathway.</p>

Effect of perioperative continuous epidural morphine administration on plasma D-dimer in patients undergoing total hip replacement / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of perioperative continuous epidural morphine administration on plasma D-dimer level in patients undergoing total hip replacement.</p><p><b>METHODS</b>Forty ASA I-II patients undergoing total hip replacement under epidural anesthesia were randomized into two groups. In one group, the patients were given epidural administration of morphine 15 min before operation at 4 mg (in 10 ml normal saline) and for 48 h after the operation at 80 microg/h, while those in the other group received epidural injection of the same amount of normal saline before operation and 0.15% ropivacaine 2.0 ml/h for 48 h in the same manner after operation. Blood samples were taken before anesthesia (T(0)), at the end of operation (T(1)), and 24 h and 48 h after operation (T(2) and T(3)) for determination of plasma IL-6 and D-dimer levels.</p><p><b>RESULTS</b>In both groups plasma IL-6 and D-dimer levels showed significant increase at T(1), T(2) and T(3) in comparison with those at T(0), and their levels were significantly lower in morphine group than in ropivacaine group at T(1), T(2) and T(3).</p><p><b>CONCLUSION</b>Epidural morphine can lower plasma IL-6 and D-dimer levels and correct blood hypercoagulability in patients undergoing total hip replacement.</p>

Solubilization on cryptotanshinone by hydroxypropyl-beta-cyclodextrin and preparation of their inclusion compound / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare cryptotanshinone (CT)-cyclodextrin inclusion compound and improve dissolution of CT.</p><p><b>METHOD</b>Inclusion ratio was determined by plotting the phase solubility curve of CT versus hydroxypropyl-beta-cyclodextrin (HPCD). CT-cyclodextrin inclusion compound was made by wet grinding method. Properties of the inclusion compound was investigated by in vitro dissolution test, DTA and IR spectrum.</p><p><b>RESULT</b>Inclusion ratio of CT versus HPCD was 1:1. Dissolution of CT-HPCD inclusion compound at 45 min was 21.6 times of material drug.</p><p><b>CONCLUSION</b>Dissolution of CT was improved remarkably in CT-HPCD inclusion compound. The complexation force of the inclusion compound was hydrogen bond formed by carbonyl group of CT and hydroxyl group of HPCD.</p>

Influence of nitric oxide on the angiotensin II-activated protein kinase C activity in cultured neonatal rat cardiomycytes / 生理学报

We examined the effect of endogenous and exogenous nitric oxide (NO) on protein kinase C (PKC) activity induced by angiotensin II (Ang II) in cultured neonatal rat cardiomyocytes. The results are as follows. The activity of PKC was increased by Ang II (0.01-10 micromol/L) in a dose-dependent manner, but decreased by NO precursor L-arginine (L-Arg) (10 micromol/L-10 mmol/L) in a dose-dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with L-Arg (100 micromol/L) decreased significantly Ang II -activated PKC activity and PKC activity induced by phorbol 12-myristate 13-acetate (PMA) ( 10 micromol/L), a PKC activator. Pretreatment with N(G)-nitro-L-argingie methyl ester (L-NAME), a nitric oxide synthase (NOS) blocker, may inhibit significantly the role of L-Arg on Ang II - and PMA-activated PKC activity. The activity of PKC was also decreased by NO donor sodium nitroprusside (SNP) (10 micromol/L-1 mmol/L) in a dose-dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with SNP (10 micromol/L) decreased significantly Ang II - and PMA-activated PKC activity. These results indicate that PKC was controlled by both NO and Ang II. PKC may be a cross talk between Ang II and NO in cardiomyocytes. NO abolished the activity of PKC and impaired PKC downstream signaling transduction pathway cascades.

Effects of antioxidation and ceramide of improved prescription of didang-tang (IPDT) on exprimental atherosclerosis rabbits / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effects of antioxidation and ceramide content of improved prescription of Didang-tang (IPDT) on exprimental atherosclerosis(AS) rabbits.</p><p><b>METHOD</b>Plasm Superoxide Dismutase(SOD) activity was detected with micro-content fast detecting method, Plasm Malondialdehyde(MDA) content with improved BaMuGuoFu method, and Aortic Ceramide (CER) content with thinlayer scanning.</p><p><b>RESULT</b>IPDT could effectivly improve plasma SOD activity and decrease plasma MDA content and decrease aortic CER content.</p><p><b>CONCLUSION</b>IPDT on exprimental AS is related to the improvement of antioxidation and decrease of CER content.</p>

Molecular mechanism of nitric oxide in preventing cardiomyocytes from hypertrophic response induced by angiotensin II / 生理学报

The aim of this study was to determine the molecular mechanism of nitric oxide (NO) in preventing cardiomyocytes from hypertrophic response induced by angiotensin II (Ang II). Hypertrophic response of neonatal rat cardiomyocytes was assayed by protein synthesis rate and expression of atrial natriuretic peptide (ANP) mRNA. The level of NO was shown by the content of nitrate and nitrite in cardiac myocytes. The protein expression of MKP-1 and the gene expression of eNOS were measured with Western blotting and RT-PCR, respectively. The results are as follows. (1) L-arginine (L-Arg) induced a dose-dependent increase in NO by 16% and 31% at the concentrations of 10 micromol/L and 100 micromol/L, respectively. L-Arg also increased the gene expression of eNOS. However, these effects were inhibited by L-NAME, the inhibitor of NOS. (2) The gene expression and the protein synthesis of ANP induced by Ang II (0.1 micromol/L) were inhibited by L-Arg (100 micromol/L). The inhibitory action of L-Arg was abolished after pretreatment with antisense oligoneucleotide against MKP-1. (3) L-Arg (100 micromol/L) increased the protein expression of MKP-1 by 225%, which was inhibited by L-NAME, an NOS inhibitor, and KT-5823, a cGMP-dependent protein kinase (PKG) inhibitor. However, Ang II enhanced the effect induced by L-Arg. The above results show that NO may activate PKG, and thereby promote the protein expression of MKP-1 and inactivate MAPK, resulting in an inhibition of cardiomyocyte hypertrophic response induced by Ang II.