Pengli Zhu

Resveratrol Protects against TNF-α-Induced Injury in Human Umbilical Endothelial Cells through Promoting Sirtuin-1-Induced Repression of NF-KB and p38 MAPK.

Inflammation and reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerosis. Resveratrol has been shown to possess anti-inflammatory and antioxidative stress activities, but the underlying mechanisms are not fully understood. In the present study, we investigated the molecular basis associated with the protective effects of resveratrol on tumor necrosis factor-alpha (TNF-α)-induced injury in human umbilical endothelial cells (HUVECs) using a variety of approaches including a cell viability assay, reverse transcription and quantitative polymerase chain reaction, western blot, and immunofluorescence staining. We showed that TNF-α induced CD40 expression and ROS production in cultured HUVECs, which were attenuated by resveratrol treatment. Also, resveratrol increased the expression of sirtuin 1 (SIRT1); and repression of SIRT1 by small-interfering RNA (siRNA) and the SIRT1 inhibitor Ex527 reduced the inhibitory effects of resveratrol on CD40 expression and ROS generation. In addition, resveratrol downregulated the levels of p65 and phospho-p38 MAPK, but this inhibitory effect was attenuated by the suppression of SIRT1 activity. Moreover, the p38 MAPK inhibitor SD203580 and the nuclear factor (NF)-κB inhibitor pyrrolidine dithiocarbamate (PDTC) achieved similar repressive effects as resveratrol on TNF-α-induced ROS generation and CD40 expression. Thus, our study provides a mechanistic link between resveratrol and the activation of SIRT1, the latter of which is involved in resveratrol-mediated repression of the p38 MAPK/NF-κB pathway and ROS production in TNF-α-treated HUVECs.

Synergistic effects of telmisartan and pyridoxamine on early renal damage in spontaneously hypertensive rats.

The aim of this study was to investigate the protective effects of telmisartan and/or pyridoxamine on spontaneously hypertensive rats (SHRs). Rats were treated with telmisartan (T group) or pyridoxamine (P group), or telmisartan and pyridoxamine (TP group). The serum levels of advanced glycation end products (AGEs), superoxide dismutase (SOD), malonaldehyde and the level of 24-h urinary albumin were measured. Morphological changes in renal tissues were observed under light (H&E or Massons trichrome) and transmission electron microscopy. Expression of NF-κBp65 and p-ERK1/2 in renal tissue was detected by immunohistochemistry. Expression of receptors for advanced glycation end products (RAGE) and TGF-β in the renal cortex was investigated by western blotting. We found that early renal structural and functional damage was alleviated in the three intervention groups. SOD activity was significantly elevated in the P and TP groups (P<0.05) compared to that in the T group. Of note, both the positive expression of NF-κBp65 (P<0.01 vs. the T and P groups) and p-ERK1/2 (P<0.05 vs. the P group) was lowest in the TP group. Our results suggest that the combined use of telmisartan and pyridoxamine is superior to the single use of either drug on renoprotection, which may result from the alleviation of oxidative stress and the reduction of NF-κBp65 and p-ERK1/2 activation.

GW28-e1025 The relationship between sodium excretion and blood pressure, urine albumin, central retinal arteriolar equivalent

Many studies showed an association between dietary salt intake, blood pressure and increased CVD risk. The potential reason may be related to vascular structural and functional changes, through alterations in endothelial function. The central retinal arteriolar equivalent and urinary albumin

GW27-e1069 Synergistic effect of a tissue kallikrein 1 and tissue inhibitor of matrix metalloproteinase 1 co expression vector on the proliferation of rat vascular smooth muscle cells

Tissue kallikrein 1 (TK1) and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) are important in inhibiting vascular smooth muscle cell (VSMC) proliferation and improving vascular remodeling, respectively. It was hypothesized that a combination of TK1 and TIMP1 genes, mediated by an adenovirus

PS 05-40 PLASMA APELIN LEVELS, BLOOD PRESSURE AND CARDIOVASCULAR RISK FACTORS IN A COASTAL CHINESE POPULATION

Objective: To describe the relationship of plasma apelin levels with blood pressure in a coastal Chinese population. Design and Method: This cross-sectional study included a total of 1031 subjects from the coastal areas of China. One-way analysis of variance (ANOVA) and linear trend test, Pearsons correlation analysis, as well as multivariate linear regression analysis were used to evaluate the association between plasma apelin levels and blood pressure. Results: Plasma apelin levels dropped with increasing quartiles of systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MABP) (all P < 0.001). SBP, DBP, and MABP values decreased as the apelin levels increased within the quartiles. After adjusting for age and gender, the significant differences in SBP, DBP, and MABP between the groups within the apelin quartiles remained (all P < 0.05). A significant negative correlation between SBP, DBP, as well as MABP and apelin levels was observed (all P < 0.01); even after adjusting for cardiovascular confounding factors, this negative correlation remained (all P < 0.001). Conclusions: A negative correlation between plasma apelin levels and blood pressure was found in this 1000-population-based epidemiological study. Apelin may become a potential therapeutic target of anti-hypertensive treatment.

[PS 01-23] SYNERGISTIC EFFECT OF A TISSUE KALLIKREIN 1 AND TISSUE INHIBITOR OF MATRIX METALLOPROTEINASE 1 CO—EXPRESSION VECTOR ON THE PROLIFERATION OF RAT VASCULAR SMOOTH MUSCLE CELLS

Objective: Tissue kallikrein 1 (TK1) and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) are important in inhibiting vascular smooth muscle cell (VSMC) proliferation and improving vascular remodeling, respectively. It was hypothesized that a combination of TK1 and TIMP1 genes, mediated by an adenovirus vector could augment or act in synergy to enhance the inhibitory effects. Design and Method: The promoter, mCMV carrying hTIMP1 cDNA was subcloned into pDC316—hTK1 to construct a recombinant plasmid carrying hTK1 and hTIMP1 genes. Subsequently, the double gene plasmid and adenovirus backbone plasmid were packaged into HEK293A cells. Gene transcription and protein expression were examined, respectively using reverse transcription—quantitative polymerase chain reaction (PCR) and western blotting assays. VSMC proliferation was assessed using cell counting and methyl—thiazolyl—tetrazoliuin methods. Results: The constructed plasmid containing hTK1 and hTIMP1 genes was correctly identified by means of PCR, double digestion and sequencing analysis. The co—expression vector, Ad—hTK1—hTIMP1 was successfully constructed and packaged into HEK293A cells. When VSMCs were transfected with the co—expression vector, the mRNA transcription and protein expression of hTK1 and hTIMP1 exhibited abundant expression in a concentration—dependent and time—dependent manner, independently. Conclusions: The co—expression vector synergistically inhibited the cell growth and proliferation induced by platelet—derived growth factor—BB compared with the single gene vector.

PS 07-06 RESVERATROL PROTECTS AGAINST TNF-α-INDUCED INJURY IN HUMAN UMBILICAL ENDOTHELIAL CELLS THROUGH PROMOTING SIRTUIN-1-INDUCED REPRESSION OF NF-KB AND P38 MAPK

Objective: Inflammation and reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerosis. Resveratrol has been shown to possess anti-inflammatory and antioxidative stress activities, but the underlying mechanisms are not fully understood. Design and Method: In the present study, we investigated the molecular basis associated with the protective effects of resveratrol on tumor necrosis factor-alpha (TNF-&agr;)-induced injury in human umbilical endothelial cells (HUVECs) using a variety of approaches including a cell viability assay, reverse transcription and quantitative polymerase chain reaction, western blot, and immunofluorescence staining. Results: We showed that TNF-&agr; induced CD40 expression and ROS production in cultured HUVECs, which were attenuated by resveratrol treatment. Also, resveratrol increased the expression of sirtuin 1 (SIRT1); and repression of SIRT1 by small-interfering RNA (siRNA) and the SIRT1 inhibitor Ex527 reduced the inhibitory effects of resveratrol on CD40 expression and ROS generation. In addition, resveratrol downregulated the levels of p65 and phospho-p38 MAPK, but this inhibitory effect was attenuated by the suppression of SIRT1 activity. Moreover, the p38 MAPK inhibitor SD203580 and the nuclear factor (NF)-&kgr;B inhibitor pyrrolidine dithiocarbamate (PDTC) achieved similar repressive effects as resveratrol on TNF-&agr;-induced ROS generation and CD40 expression. Conclusions: Our study provides a mechanistic link between resveratrol and the activation of SIRT1, the latter of which is involved in resveratrol-mediated repression of the p38 MAPK/NF-&kgr;B pathway and ROS production in TNF-&agr;-treated HUVECs.

PS 08-33 INFLUENCE OF CHANGES IN SERUM URIC ACID LEVELS ON RENAL FUNCTION IN ELDERLY PATIENTS WITH HYPERTENSION: A RETROSPECTIVE COHORT STUDY WITH 3.5-YEAR FOLLOW-UP

Objective: Hyperuricemia is closely related to renal diseases. Therefore, the aim of this study was to explore the relationship between the longitudinal changes in serum uric acid and the estimated glomerular filtration rate (eGFR) in a cohort of elderly hypertensive patients. Design and Method: Eighty hundred and thirty-seven re-hospitalized patients with hypertension were included in this retrospective cohort study. Multiple regression analysis was used to investigate the relationship between changes in serum uric acid and renal function after 3.5 years follow-up. Results: The average age at baseline was 69.0+/-10.0 years, and the average follow-up duration was 3.5 years. Multiple linear regression analysis showed that the baseline uric acid levels had a linearly negative correlation with baseline eGFR (P < 0.01), after adjustment for age, gender, blood pressure, and body mass index, et al. An increase of 100 &mgr;mol/L baseline uric acid level resulted in a decrease of 5.684 ml/min/1.73 m2 in eGFR [95% confidence interval (CI): 7.735–3.633]. Patients with increased uric acid levels had higher risk of renal function decline over the follow-up period, with an adjusted odds ratio of 1.639 (95% CI: 1.129–2.378, P = 0.009), whereas eGFR was remained unchanged in patients with hyperuricemia at baseline and with normal uric acid level 3.5-year later. Conclusions: Longitudinal changes in uric acid levels were independently associated with the renal function decline in elderly patients with hypertension. Uric acid level should be considered in hypertension management in the elderly.

Synergistic effect of a tissue kallikrein 1 and tissue inhibitor of matrix metalloproteinase 1 co‑expression vector on the proliferation of rat vascular smooth muscle cells

Tissue kallikrein 1 (TK1) and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) are important in inhibiting vascular smooth muscle cell (VSMC) proliferation and improving vascular remodeling, respectively. It was hypothesized that a combination of TK1 and TIMP1 genes, mediated by an adenovirus vector could augment or act in synergy to enhance the inhibitory effects. The promoter, mCMV carrying hTIMP1 cDNA was subcloned into pDC316-hTK1 to construct a recombinant plasmid carrying hTK1 and hTIMP1 genes. Subsequently, the double gene plasmid and adenovirus backbone plasmid were packaged into HEK293A cells. Gene transcription and protein expression were examined, respectively using reverse transcription-quantitative polymerase chain reaction (PCR) and western blotting assays. VSMC proliferation was assessed using cell counting and methyl-thiazolyl-tetrazoliuin methods. The constructed plasmid containing hTK1 and hTIMP1 genes was correctly identified by means of PCR, double digestion and sequencing analysis. The co-expression vector, Ad-hTK1-hTIMP1 was successfully constructed and packaged into HEK293A cells. When VSMCs were transfected with the co-expression vector, the mRNA transcription and protein expression of hTK1 and hTIMP1 exhibited abundant expression in a concentration-dependent and time-dependent manner, independently. In conclusion, the co-expression vector synergistically inhibited the cell growth and proliferation induced by platelet-derived growth factor-BB compared with the single gene vector.

Effects of pyridoxamine on preliferation of rat vascular smooth muscle cells

Objective To investigate the influence of pyridoxamine on the pre- iferation of rat vascular smooth muscle cells induced by Angiotensin (A)in vitro and its mechanism. Methods Primary VSMCs were cultivated from the thoracic aortas of spontaneously hypertensive rats, and which from the 3th to 5th generation at exponential phase of growth were selected for the experiments and induced by A (10−7 mol/l). The proliferation of VSMCs after intervention with pyridoxamine (0.1, 1 and 10 mmol/l) was determined by MTT. The levels of advanced glycation end-products in cellular supernatant was determined by enzyme-linked immunosorbent assay (ELISA) and the intracellular level of reactive oxygen species (ROS) was detected by f1ow cytometry. The mRNA expressions of RAGE, NF-κB-P65, NADPH oxidaseP47phox were detected by Real-time PCR. Results The proliferation of VSMCs induced by A was inhibited by pyridoxamine in dependent-concentration manner (0.1, 1 and 10 mmol/l). The cellular supernatant AGEs level in pyridoxamine (1 mmol/l, P1) and pyridoxamine (10 mmol/l, P10) group was significantly lower (p<0.001) as compared with A group. It was decreased more in P10 group than that in P1 group (p<0.001); the intracellular ROS level significantly was decreased in P1and P10 group as compared with that in A group (p<0.001), and less in P10 group than that in P1 group (p<0.001); Compared with A group, The mRNA expressions of advanced glycation end-products receptor (RAGE), NF-κB-P65, NADPH oxidaseP47phox and MMP-9 mRNA in P1 and P10 group all were significantly lower (p<0.01), and they were much decreased in P10 group than that in P1 group (p<0.01). Conclusions The pyridoxamine inhibits the proliferation of VSMCs induced by A in dependent-concentration manner, and the potential mechanism of which pyridoxamine may reduce the expressions of RAGE by NF-κB pathway signals and inhibiting AGEs expressing and oxidative stress.