The changes and effects of Apelin/APJ system in LPS-induced injury of rat pulmonary microvascular endothelial cells / 中国药理学通报

ABSTRACT

Aim To explore the changes of Apelin/APJ system in LPS-induced injury of rat pulmonary mi-crovascular endothelial cells( PMVECs) , and the effect and mechanism of Apelin. Methods PMVECs were cultured with the explant technique, and the identifica-tion of rat PMVECs was carried out by immunocyto-chemical staining of factorⅧrelated antigen. MTT as-say was used to evaluate the viability of PMVECs. The mRNA expression of Apelin and APJ was detected by RT-PCR. The protein expression of PCNA and the phosphorylation of Akt was analyzed by Western blot. Results The mRNA expression of Apelin and APJ showed a compensatory increase after LPS treatment for a short period of time ( P<0. 01 ) , but with the exten-sion of time, which was significantly inhibited, even lower than the control group ( P<0. 05 or P<0. 01 ) , suggesting that Apelin/ APJ system might be involved in LPS-induced PMVECs injury. MTT results showed that 10 -6 ~10 -9 mol · L-1 Apelin obviously promoted the proliferation of rat PMVECs ( P <0. 05 or P <0. 01 ) , and with certain concentration and time de-pendence. Moreover, Apelin also improved the LPS-induced PMVECs injury in different degrees ( P<0. 05 or P < 0. 01 ) . In addition, Western blot analysis showed that Apelin significantly reversed the decrease of the protein expression of PCNA and the Akt phos-phorylation level induced by LPS ( P <0. 05 or P <0. 01 ) . Conclusions The Apelin/APJ system is in-volved in LPS-induced PMVECs injury. Apelin plays an important role in protecting the pulmonary microvas-cular endothelial function and reversing the LPS-in-duced PMVECs injury, which might be related to the activation of Akt phosphorylation pathway.