Growth inhibition of bovine pulmonary artery smooth muscle cells following long‐term heparin treatment

Abstract

Heparin (HP) inhibits pulmonary artery smooth-muscle cell (PASMC) growth in vitro and vascular remodeling in vivo. Barzu et al (1994) suggested that the antiproliferative effect of HP on rat aortic smooth muscle cell in vitro diminishes with prolonged exposure to heparin. We exposed cultured bovine PASMC (BPASMC) to prolonged pretreatment with 20μg/ml of 0-hexanoylated HP from passages 3 to13 and compared them to control (no pretreatment) cultures of identical passages. The pretreated BPASMC and control groups were growth arrested for 48 hrs, followed by treatment of 0-hexanoylated HP at different doses. On day five, the growth inhibition of BPASMC was determined. The percent inhibition by 1μg/ml of 0-hexanoylated HP was 46±14% vs. 62±13%, for control and pretreated BPASMC respectively. At 10μg/ml the inhibition was 62±7% vs. 84±6%. For 100μg/ml the inhibition increased to 92±5% vs. 100% and at 200μg/ml the inhibition was 95±3% vs. 100%. BPASMC (with or without preexposure to 0-hexanoylated HP), at passage 13, were sensitive to the growth inhibitory effect of 0-hexanoylated HP with no significant difference among the groups (95±3% inhibition vs. 100% for pretreated BPASMC). We found that 0-hexanoylated HP induced necrosis as shown by flow cytometry and only minor apoptosis. Caspase3 and PARP detection was insignificant between the groups. In summary, no cell subpopulation at long-term treatment exhibited resistance to 0-hexanoylated HP. The HP antiproliferative effect on SMC is potentially important in defining new approaches to the treatment of the remodeled vasculature of pulmonary hypertension.

Role of parnaparin in atherosclerosis

“…; Mrabat et al . ). Because vascular atherosclerosis is a typical VSMC proliferative lesion, it is reasonable to hypothesize that PNP could ameliorate vascular remodelling in atherosclerosis‐prone mice, such as ApoE−/−.…”

Antiproliferative Effect of Echinacoside on Rat Pulmonary Artery Smooth Muscle Cells Under Hypoxia

“…Procaspase-3 could be directly or indirectly activated by other factors, and the active enzyme is composed of two subunits of 17 kDa and 12 kDa (28,29). We investigated the effect of caspase-3 in the suppression effect of ECH using the caspase-3-specific inhibitor Z-DEVD-FMK.…”

Low molecular weight (LMW) heparin inhibits injury-induced femoral artery remodeling in mouse via upregulating CD44 expression

“…As previously described, 5 growth inhibition analysis was introduced to assess the most effective antiproliferative dose of LMW heparin for in vitro assay. VSMCs between passages four and six were used to perform this study.…”

“…Western blot analysis was performed as previously described. 5 Protein was extracted from the femoral arteries of each group (five mice were used in each group) or cultured mouse VSMCs. CD44 antibody (rabbit polyclonal antibody; Abcam Inc, Cambridge, Mass) and GAPDH (mouse monoclonal antibody, Research Diagnostics Inc, Flanders, NJ) were used for Western blot detection.…”

“…LMW heparin has been shown to inhibit VSMC proliferation. 4 Our previous studies have indicated that LMW heparin inhibits pulmonary vascular remodeling in bovine and rodent models, 5,6 but the mechanism of this inhibition is not well understood.…”