Penehyclidine effects the angiogenic potential of pulmonary microvascular endothelial cells

The present study sought to determine the pharmacological effects of penehyclidine, an anticholinergic agent, on the angiogenic capacity of pulmonary microvascular endothelial cells (PMVECs). In vitro Matrigel network formation assay, cell proliferation assay, cell-matrix adhesion assay, and wound-healing assay were performed in PMVECs with or without exposure to penehyclidine or, in some cases, glycopyrrolate or acetylcholine, over a concentration range. In addition, the phosphorylation state of Akt and ERK, as well as the endogenous level of mTOR and RICTOR were examined in PMVECs by Western blot following the cells exposure to penehyclidine or, for some proteins, glycopyrrolate or acetylcholine. Finally, Western blot for Akt phosphorylation and in vitro Matrigel network formation assay were performed in PMVECs following their exposure to penehyclidine with or without phosphoinositide 3-kinase (PI3K) inhibitor LY294002 or mTOR inhibitor torin-1. We found that, in PMVECs, penehyclidine affected the network formation and cell migration, but not proliferation or cell-matrix adhesion, in a concentration-specific manner, i.e., penehyclidine increased the network formation and cell migration at lower concentrations but increased these processes at higher concentrations. Coincidentally, we observed that penehyclidine concentration-specifically affected the phosphorylation state of Akt in PMVECs, i.e., increased Akt phosphorylation at lower concentrations and decreased it at higher concentrations. In contrast, glycopyrrolate was found straightly to decrease network formation and Akt phosphorylation in a concentration-dependent manner. Further, we demonstrated that PI3K or mTOR blockade abolished both the enhanced network formation and the increased Akt phosphorylation by penehyclidine. Hence, penehyclidine may differentially alter the angiogenic capacity of PMVECs through affecting the Akt signaling pathway downstream of PI3K and mTOR. Findings from this study suggest a unique pharmacological feature of penehyclidine, which may imply its clinical and therapeutic value in modulating angiogenesis.