Afferent Renal Denervation Attenuates Sympathetic Overactivation From the Paraventricular Nucleus in Spontaneously Hypertensive Rats.

BACKGROUND: The effectiveness of renal denervation (RDN) in reducing blood pressure and systemic sympathetic activity in hypertensive patients has been established. However, the underlying central mechanism remains unknown. This study aimed to investigate the role of RDN in regulating cardiovascular function via the central renin-angiotensin system (RAS) pathway. METHODS: Ten-week-old spontaneously hypertensive rats (SHR) were subjected to selective afferent renal denervation (ADN) using capsaicin solution. We hypothesized that ADN would effectively reduce blood pressure and rebalance the RAS component of the paraventricular nucleus (PVN) in SHR. RESULTS: The experimental results show that the ADN group exhibited significantly lower blood pressure, reduced systemic sympathetic activity, decreased chronic neuronal activation marker C-FOS expression in the PVN, and improved arterial baroreflex function, compared with the Sham group. Furthermore, ACE and AT1 protein expression was reduced while ACE2 and MAS protein expression was increased in the PVN of SHR after ADN. CONCLUSIONS: These findings suggest that RDN may exert these beneficial effects through modulating the central RAS pathway.

Effect of Exercise Prescription Implementation Rate on Cardiovascular Events.

BACKGROUND: Exercise prescription of cardiac rehabilitation (CR) is vital in patients with cardiovascular diseases (CVDs) and those carrying high risk for CVDs. However, the relation between the implementation rate of exercise prescription and cardiovascular events (CVEs) is unclear. DESIGN AND METHODS: In this retrospective study, using the administration data from the Rehabilitation Center in a hospital, patients aged ≥18 years with CVDs were consecutively enrolled from November 2018 to May 2021. Patients were divided into the high execution group (HEG) and low execution group (LEG) depending on whether they completed more than half the time of the exercise prescriptions. Baseline characteristics, ultrasonic cardiogram, cardiopulmonary exercise test, follow-up data, and CVEs were collected. RESULTS: The mean age of the 197 CR patients was 61.8 ± 13.7 years and the mean follow-up duration was 10.9 ± 4.2 months. Among them, 15 patients suffered CVEs: 4 in the HEG and 11 in the LEG. The incidence of CVEs showed significant differences between HEG and LEG (chi-square test). Free-event survival analysis using Kaplan-Meier survival plots showed that patients in LEG had poor survival. Cox proportional hazards regression analysis revealed that the prescription implementation rate was an independent predictor of CVEs. CONCLUSIONS: Our study suggested a significant effect of exercise prescription execution rate on the occurrence of CVEs. Further, the HEG of exercise prescription was associated with lower CVDs.

[Association between high sensitivity C-reactive protein and contrast induced acute kidney injury in patients with acute coronary syndrome undergoing percutaneous coronary intervention: impact of atorvastatin].

OBJECTIVE: To observe the association between preprocedural high sensitivity C-reactive protein (hs-CRP) level and incidence of contrast induced acute kidney injury (CI-AKI) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) and the impact of atorvastatin pretreatment on CI-AKI. METHODS: According to the level of preprocedural hs-CRP, 270 ACS patients were divided into three groups: high hs-CRP group (hs-CRP ≥ 3 mg/L, n = 176), moderate hs-CRP group (hs-CRP 1-3 mg/L, n = 60) and normal hs-CRP group (hs-CRP < 1 mg/L, n = 34). According to the dosage of preprocedural atorvastatin, the high hs-CRP group was further divided into 10 mg group (n = 49), 20 mg group (n = 66) and 40 mg group (n = 61). Serum creatinine (Scr), blood urea nitrogen (BUN), cystatin C (Cys C), hs-CRP were measured at before and 24 hours, 48 hours after PCI. CCr and GFR were calculated according to Scr and Cys C. Risk factors for CI-AKI were determined by multivariate logistic regression analysis. RESULTS: (1) Cys C was significantly increased and GFR after PCI significantly reduced in high and moderate hs-CRP groups compared with normal hs-CRP group (P < 0.05). (2) Incidence of CI-AKI was 43.18%, 38.33%, 20.59% in high, moderate and normal hs-CRP groups, respectively (P < 0.05). (3) In high hs-CRP group, postprocedural GFR was significantly higher while postprocedural Cys C and hs-CRP were significantly lower in 40 mg statin subgroup than 10 mg and 20 mg statin subgroups (P < 0.05), similar trends were documented when comparing 20 mg statin subgroup with 10 mg statin subgroup (P < 0.05). (4) Multivariate logistic regression analysis showed that pretreatment with high dose atorvastatin was a protective factor for post CI-AKI (20 mg atorvastatin: OR = 0.15, 95%CI 0.06 - 0.33, P = 0.001; 40 mg atorvastatin: OR = 0.10, 95%CI 0.04 - 0.23, P = 0.001), while high levels of preprocedural hs-CRP (OR = 2.06, 95%CI 1.01 - 4.23, P = 0.048), diabetes mellitus (OR = 10.71, 95%CI 5.29 - 21.70, P = 0.001), advanced age (OR = 2.64, 95%CI 1.05 - 6.63, P = 0.038) and renal failure (OR = 5.14, 95%CI 1.13 - 23.39, P = 0.034) were independent risk factors of CI-AKI. CONCLUSION: High hs-CRP level is linked with the development of CI-AKI in ACS patients undergoing PCI and pretreatment with 40 mg atorvastatin is associated with lower incidence CI-AKI, possibly by reducing the postprocedural inflammation responses.

[Arresting effect of p16 and dll4 transfection on cell cycle of K562 cells].

This study was purposed to investigate the expression and role of eukaryotic expression vector containing p16, dll4 genes in leukemia K562 cells. A vector pBudCE4.1-16-dll4 containing wild type p16cDNA and dll4cDNA was designed and constructed, then this vector was transfected into leukemia K562 cells by using lipofectamine 2000. The expression of p16 and dll4 genes was detected by Western blot, the cell growth curve and cell cycle were determined by CCK-8 kit and flow cytometry respectively. The results showed that the recombinant plasmid pBudCE4.1-16-dll4 was constructed and transfected into K562 cells in vitro successfully. The expression of exogenous P16 and Dll4 proteins could be detected in K562 cells. After transfection for 48 hours, the K562 cells were arrested in G(1) phase, the cell count increased in G(0)/G(1) phase and reduced in S phase, the cell proliferation decreased as compared with control. It is concluded that the p16 and dll4 genes can simultaneously express in K562 cells transfected with recombinant plasmid pBudCE4.1-16-dll4 in vitro which results in G(0)/G(1) arrest and reduces cell proliferation.

[Inhibitory effect of p16, p53 transfection on leukemic cell lines K562 and HL-60].

This study was purposed to construct a vector containing human suppressor gene p53 and p16, and to investigate their expression and effect on K562 and HL-60 cells. pBudCE4.1-53-16 is a vector designed for simultaneous expression of human suppressor gene p53 and p16 in mammalian cell line. After transfection into K562 cells with lipofectamine(TM) 2000, the expression of p53 and p16 genes was detected by Western blot and immunocytochemical method. The growth curve, apoptosis, cell cycle were assayed by CCK-8 and flow cytometry. The results showed that the recombinant plasmid pBudCE4.1-53-16 was constructed successfully and were verified by PCR and restriction analysis. The expression of P53 and P16 protein could be detected after transfection into leukemia cells (K562 and HL-60) for 48 hours. As compared with control group, the cell proliferation in experimental group was inhibited, the cells were arrested in G0 phase and apoptotic cells increased (p<0.001). It is concluded that the recombinant plasmid pBudCE4.1-53-16 has been established. p16 and p53 in the recombinant plasmid pBudCE4.1-53-16 synchronously express in leukemic cells after transfection in vitro for 2 days and results in reduced proliferation, G0 arrest and apoptosis increase.

[Atorvastatin attenuated contrast induced renal function damage].

OBJECTIVE: To study the effects of atorvastatin on contrast induced renal function change and plasma hsCRP in patients undergoing coronary angiography. METHODS: 120 patients who underwent coronary angiography were randomized to receive atorvastatin (20 mg/qn, n = 60) or no atorvastatin (n = 60) treatment 2 to 3 days before coronary angiography. Urinary alpha1-MG, TRF and mALB were checked for evidence of tubular or glomerular damage at start, 1 day and 2 days after the administration of a radiocontrast agent. Serum creatinine, BUN, cystatin C and hsCRP levels were also assessed at the same time. Ccr and GFR were calculated according to Cockcroft-Gault and GFR (ml/min) = 74.835/Cys C(1.333) formulas basing on serum creatinine or cystatin C concentration. RESULTS: (1) In control group, comparison with the value before coronary angiography, urinary alpha1-MG, TRF and mALB or serum cystatin C and hsCRP significantly increased at day 1 after angiography (P < 0.01). In comparison to the levels at day 1 after angiography, urinary alpha1-MG, TRF, mALB, serum cystatin C significantly decreased at day 2 after angiography (P < 0.01), but alpha1-MG, cystatin C still exceeded the values before coronary angiography, TRF and mALB levels at day 2 after angiography had no significant change compared to baseline (P > 0.05), hsCRP level at day 2 after angiography had no significant change compared to that at day 1 after angiography (P > 0.05) too. (2) In comparison with the value before coronary angiography in atorvastatin-treated group, the levels of urinary alpha1-MG, TRF and mALB or serum cystatin C at day 1 and day 2 after angiography had no significant change compared to baseline (P > 0.05).Serum hsCRP significantly increased at day 1 after angiography compared to baseline (P < 0.01), but it had no significant change compared to day 2 after angiography (P > 0.05). (3) To compare to the atorvastatin-treated group, the values of urinary alpha1-MG, TRF and mALB or Cys C and hsCRP significantly increased at day 1 after angiography in control group (P < 0.01), the values of urinary alpha1-MG, cystatin C and hsCRP still significantly increased at day 2 (P < 0.01)too, but those of TRF and mALB had no significantly change at day 1 or day 2 after angiography between the two groups (P > 0.05). There was no significant change in BUN, Cr, Ccr levels before and after angiography between the two groups. CONCLUSIONS: Low dose contrast induces light renal function damage. Pretreatment with atorvastatin 20 mg/qn for 2 to 3 days could significantly reduce procedural inflammatory reaction, attenuate urinary protein and the effect of degrading GFR in coronary angiography patients.

[Transplantation of mesenchymal stem cells transfected with hepatocyte growth factor gene improves heart function in rats with heart failure].

AIM: To investigate the effects of hepatocyte growth factor gene transfected MSCs transplantation on cardiac function and fibrosis in rats heart failure model induced by adriamycin. METHODS: MSCs were isolated from SD rats by density gradient centrifugation, purified, and transfected with Ad-hHGF. ELISA were used to detect the protein expression of hHGF in these MSCs. Forty SD rats underwent intraperitoneal injection with adriamycin to induce heart failure model. 8 healthy rats served as control, 24 survival rats were randomly divided into 3 groups (n = 8): Rats in Ad-hHGF transfected MSCs group were injected with Ad-hHGF transfected MSCs 2 weeks after the establishment of the model, rats in MSC group injected with suspension of MSCs only, and model group was injected with cold culture fluid. Heart function was evaluated by a physiological recorder 4 weeks after cell transplantation. Myocardial cell morphology and interstitial collagen were studied by electron microscope and were stained by Sirus red. TGF-beta1 was detected by immunohistochemical method. RESULTS: (1) MSCs could be transfected efficiently by Ad-hHGF, manifested by a higher level of expression in vitro, persisting 14 days at least. (2) Four weeks after the cells transplantion, cardiac necrosis in MSC-hHGF rats was improved when compared with those in the MSCs (P < 0.05) and Model group (P < 0.01). The heart function of the MSC-hHGF rats was greatly improved with an significant increase in LVSP and + dp/dt(max), although LVEDP still highter than that of normal rats. (3) MSC-Ad-hHGF decreased Myocardial collagen content and the level of TGFbeta1 compaired with MSCs transplanted rats (P < 0.01). CONCLUSION: Transplantation of HGF gene transfected MSCs improved heart function, decreased myocardial collagen and the level of TGFbeta1.

Effect of AT2 receptor on expression of AT1 and TGF-beta receptors in VSMCs from SHR.

We recently reported that overexpression of the angiotensin II type 2 (AT2) receptor downregulates the AT1a receptor through the bradykinin/NO pathway in a ligand-independent manner in vascular smooth muscle cells (VSMCs). In the present study, we investigated the effect of AT2 receptor overexpression on the expression of the AT1a receptor and transforming growth factor-beta (TGF-beta) receptor subtypes in VSMCs from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Transfection of the AT2 receptor gene downregulated expression of the AT1a receptor in VSMCs from WKY, but did not affect expression of the AT1a receptor in VSMCs from SHR. Transfection of the AT2 receptor abolished DNA synthesis in response to angiotensin II in VSMCs from WKY; in VSMCs from SHR, basal DNA synthesis was suppressed, but DNA synthesis in response to Ang II was not altered. The NO substrate L-arginine augmented downregulation of the AT1a receptor in VSMCs from WKY, whereas it did not affect expression of the AT1a receptor in VSMCs from SHR. In response to AT2 receptor transfection, expression of TGF-beta type I receptor mRNA was suppressed significantly in VSMCs from WKY, whereas expression of TGF-beta type I receptor was not altered in VSMCs from SHR. These results suggest that the AT2 receptor downregulates AT1a and TGF-beta type I receptors in normal VSMCs, but not in SHR-derived VSMCs. The lack of downregulation of the AT1a receptor may contribute, in part, to the exaggerated growth of VSMCs from SHR.

Etidronate influences growth and phenotype of rat vascular smooth muscle cells.

Bisphosphonates have been reported to exhibit antiarteriosclerotic and anticalcification effects. We investigated the effect of a bisphosphonate, etidronate, on growth and phenotype of vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR). Etidronate (10 microM) significantly decreased DNA synthesis evaluated by [3H]thymidine incorporation in VSMC cultured without serum, and 1 microM etidronate significantly inhibited DNA synthesis in the presence of 10% calf serum. Etidronate (10 microM) significantly inhibited VSMC proliferation after 72h incubation. Etidronate (100 microM) significantly increased the expression of SM22alpha mRNA and protein in VSMC, while 10 microM etidronate significantly decreased the expression of matrix Gla mRNA. These findings indicate that etidronate inhibits the exaggerated growth of VSMC from SHR, while altering their phenotype from synthetic to contractile one. These effects of etidronate may account for its antiarteriosclerotic action.

Angiotensin II type 2 receptor gene transfer downregulates angiotensin II type 1a receptor in vascular smooth muscle cells.

Two distinct subtypes of angiotensin (Ang) II receptors, type 1 (AT(1)) and type 2 (AT(2)), have been identified. Vascular smooth muscle cells (VSMCs) usually express AT(1) receptor. To elucidate the direct effects of the AT(2) receptor on the AT(1) receptor in VSMCs, we transfected AT(2) receptor gene into cultured rat VSMCs. Overexpression of AT(2) receptor significantly decreased expression of AT(1a) receptor at both the mRNA and protein levels in the presence and absence of Ang II in VSMCs. Overexpression of AT(2) receptor increased expression of bradykinin and inducible NO in the presence and absence of Ang II in VSMCs. Bradykinin B(2) receptor antagonist HOE-140 and NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) inhibited the decreases in AT(1a) receptor expression by the overexpression of AT(2) receptor in VSMCs. L-Arginine augmented the decrease in AT(1a) receptor expression. Overexpression of AT(2) receptor suppressed basal DNA synthesis and proliferation of VSMCs and abolished response of DNA synthesis to Ang II in VSMCs. Our results demonstrate that overexpression of the AT(2) receptor downregulates AT(1a) receptor expression in rat VSMCs in a ligand-independent manner that is mediated by the bradykinin/NO pathway. Downregulation of AT(1a) receptor is a novel mechanism by which the AT(2) receptor regulates growth and metabolism of VSMCs.

Novel mechanisms of the antiproliferative effects of amlodipine in vascular smooth muscle cells from spontaneously hypertensive rats.

The calcium channel blocker amlodipine continues to be of interest due to its potential proven ability to hinder the progression of atherosclerosis and reduce the number of clinical ischemic events. Vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) are useful in the study of atherosclerosis because they show exaggerated growth with production of angiotensin II (Ang II) by conversion to the synthetic phenotype. To clarify mechanisms of the antiproliferative effects of amlodipine, we evaluated effects of the expression of growth factors, the changes in phenotype, and the proliferation of VSMC from SHR. Amlodipine significantly inhibited basal DNA synthesis and proliferation of VSMC from SHR. Amlodipine also inhibited expression of platelet-derived growth factor (PDGF) A-chain, transforming growth factor beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF) mRNAs in VSMC from SHR. Decreases in levels of PDGF A-chain and bFGF mRNAs in VSMC from SHR were greater with amlodipine than with nifedipine. Amlodipine significantly inhibited expression of the synthetic phenotype markers osteopontin and matrix Gla mRNAs, indicating that it inhibited the exaggerated growth of VSMC from SHR and suppressed the change from the contractile phenotype to the synthetic phenotype. Thus, amlodipine may be a beneficial therapeutic agent for patients with hypertensive vascular diseases.

Co-transfection of p16(INK4a) and p53 genes into the K562 cell line inhibits cell proliferation.

BACKGROUND AND OBJECTIVES: The tumor suppressor genes p53 and p16(INK4a), both of which act in tumor surveillance, are homozygously deleted in the human leukemia cell line K562. This study was performed to assess whether co-transfection of the p16(INK4a) and p53 genes could inhibit K562 cell proliferation. DESIGN AND METHODS: p16(INK4a) and p53 genes were co-transfected into K562 cells with liposome, and the expression of the transfected genes was detected by Western-immunoblotting and immunocytochemistry. The effect of the p16(INK4a) and p53 transfected cell culture was quantified by trypan blue staining, and the number of recovered viable cells was assessed every day after transfection. Cells were analyzed for expression of annexin V in order to detect apoptosis. Differentiation of transfected K562 cells was measured by the benzidine oxidation test, and the cell cycle was analyzed by flow cytometry. RESULTS: After co-transfection, there were 23% and 28% p53 and p16(INK4a) positive cells respectively. Co-transfection with p16(INK4a) and p53 genes significantly inhibited cell proliferation when compared to transfection with either p16(INK4a) or p53 gene. The percentage of cells expressing the apoptosis-related cell surface antigen annexin V was significantly higher in p53 and p16(INK4a) transfected cells than in p53 or p16(INK4a) transfected cells (6.24+/-0.37% vs 4.88+/- 0.17%, p<0.05 and vs 2.78+/-0.26%, p<0.05, respectively). p16(INK4a) and p53 co-transfection significantly increased the number of cells in G1 phase and decreased that in S phase. INTERPRETATION AND CONCLUSIONS: Expression of wild-type p16(INK4a) and p53 genes in K562 cells results in reduced proliferation and apoptosis. Introduction of exogenous p16(INK4a) and p53 genes into K562 cells might contribute to the clinical treatment of leukemia.