Polyaspartoyl l-arginine protects endothelial cells against injury

Pravastatin inhibits C-reactive protein generation induced by fibrinogen, fibrin and FDP in isolated rat vascular smooth muscle cells

OBJECTIVE

The available evidence indicates that C-reactive protein (CRP) participates directly in atherosclerosis formation as an inflammatory molecule. Our previous investigation suggested that fibrinogen, fibrin and fibrinogen degradation products (FDP) produce a pro-inflammatory effect on vascular smooth muscle cells (VSMCs) through inducing CRP generation. In the present study, we observed the effect of pravastatin on CRP generation induced by fibrinogen, fibrin and FDP in rat VSMCs.

METHODS

VSMCs from Sprague-Dawley rats were cultured. Fibrinogen, fibrin and FDP were used as stimulants for CRP generation. VSMCs were preincubated with pravastatin at 10, 30, 100 μM for 30 min prior to stimulation. CRP mRNA expression was studied by reverse transcription polymerase chain reaction (RT-PCR). CRP levels in the supernatant of VSMCs were measured by enzyme-linked immunosorbent assay (ELISA). CRP expression in VSMCs was examined with immunocytochemical staining.

RESULTS

ELISA analysis showed that the pravastatin concentration-dependently reduced fibrinogen-, fibrin- and FDP-stimulated generation of CRP in VSMCs, with maximal inhibition of 56.6, 55.7 and 62.3%, respectively. Immunocytochemical staining and RT-PCR revealed that pravastatin inhibited protein and mRNA expression of CRP in VSMCs significantly.

CONCLUSIONS

Pravastatin at the concentrations used in the present experiment has ability to relieve vascular inflammation and to restrain atherosclerotic processes via inhibiting the CRP production induced by fibrinogen, fibrin and FDP in VSMCs, which helps explain the beneficial effects of pravastatin on atherosclerosis.

Synthesis, nanofeatures, in vitro thrombus lysis activity and in vivo thrombolytic activity of poly-α,β-aspartyl-L-alanine

Aim: Applying nanoscale assembly to the design of a thrombolytic agent. Materials: poly-α,β-DL-aspartyl-L-alanine (molecular weight: 15726 atomic mass units) from the thermal polycondensation of DL-aspartic acid and the amidation of polysuccimide with L-alanine. Methods: The correlation of concentration and pH with nanofeatures, the correlation of concentration with in vitro thrombus lysis activity, the correlation of dose with the in vivo thrombolytic activity and the correlation of the dose with nanofeatures are all explained in this article. Results: Poly-α,β-DL-aspartyl-L-alanine was concentration- (6.4 × 104,2,-4,-6,-8,-10,-12 nM) and pH-dependently (pH 1.2, 7.4 and 7.6) assembled to various nanospecies, exhibited concentration-dependent (4, 8 and 16 µM) lysis action in vitro and dose-dependent (5, 0.5 and 0.05 µmol/kg) thrombolytic action in vivo. Conclusion: Upon entering the stomach, intestinal tract, blood and tissue fluids, poly-α,β-DL-aspartyl-L-alanine assembled to small nanoparticles or nanoblocks to escape the entrapment by macrophages and exhibited desirable thrombolytic action.