title: PCV2 induces apoptosis and modulates calcium homeostasis in piglet lymphocytes in vitro.
abstract: This study investigated the process of PCV2-induced apoptosis and the effect of PCV2 inoculation on calcium homeostasis in piglet lymphocytes in vitro. PCV2-inoculated lymphocytes exhibited chromatin condensation, chromatin segregation, the appearance of membrane-enclosed apoptotic bodies, and DNA fragmentation. Moreover, the proportion of apoptotic cells increased significantly in PCV2-inoculated lymphocytes compared with controls. These results demonstrate that PCV2 induces lymphocyte apoptosis. Some evidence suggests that an alteration in the intracellular free Ca2+ concentration ([Ca2+]i) could cause apoptosis. We measured elevated [Ca2+]i in PCV2-inoculated lymphocytes for 12 or 24 h compared with controls. Our results support that PCV2-induced apoptosis may be relative to [Ca2+]i. In addition, calmodulin (CaM) was increased in PCV2-inoculated lymphocytes for 12 h compared with controls. The amount of CaM-dependent protein kinase II (CaMKII) did not change with PCV2 inoculation. We infer that the increased [Ca2+]i can bind CaM protein, but functions independently of CaMKII. Inositol 1,4,5-trisphosphate receptor (IP3R)-1 mRNA expression increased with PCV2 inoculation, whereas plasma Ca2+-ATP4 mRNA expression decreased. A decreased Ca2+-ATP4 level may inhibit Ca2+ efflux, and the increased IP3R-1 may trigger Ca2+ release from the endoplasmic reticulum. Both of these changes may contribute to increased [Ca2+]i.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Lv
authors.forename: Lei
authors.initials: L
authors.lastname: Dai
authors.forename: Huili
authors.initials: H
authors.lastname: Han
authors.forename: Shuxia
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D017925:Circovirus / Q000145:classification / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D008214:Lymphocytes / Q000378:metabolism* / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine
chemical_list: D002118:Calcium