Comparative proteomic analysis associated with term placental insufficiency in cloned pig

Abstract

Somatic cell-derived nuclear transfer (scNT) is a method of animal cloning in which the oocyte reprograms a somatic cell nucleus to divide and execute developmental programs. Despite many successes in this field, cloning by scNT remains very inefficient. Unlike other cloned animals, pigs derived by scNT have placentas with severe villous hypoplasia. To obtain a better understanding of the protein networks involved in this phenomenon, we assessed global protein expression profiles in term placentas from scNT-derived and control animals. Proteomic analysis of term placentas from scNT-derived animals identified 43 proteins that were differentially expressed compared to control animals. Among them, 14-3-3 proteins and Annexin V, which are closely involved in the apoptotic signaling pathway, were significantly down- and up-regulated, respectively. Western blot analysis and immunohistochemistry indicated that down-regulation of 14-3-3 proteins in scNT-derived placentas induced apoptosis of cytotrophoblast cells via mitochondria-mediated apoptosis. Taken together, our results suggest that placental insufficiency in scNT-derived placentas may be due to apoptosis, induced in part by the down-regulation of 14-3-3 proteins and up-regulation of Annexin V. They also indicate that proteomic maps represent an important tool for future studies of placental insufficiency and pathology.

Serial cloning of pigs by somatic cell nuclear transfer: Restoration of phenotypic normality during serial cloning

“…Histological analyses of 28 of the 38 scNT clones that died after birth revealed 11 had distinct histological anomalies, the most common of which was meningitis, followed by poor development of the elbow joint bone, flexor tendons, congestion, and Leydig cell hypoplasia (Park et al, 2004(Park et al, , 2005. As shown in our very recent report, the abnormal histopathologic findings of the deceased cloned pigs are closely associated with aberrant protein expression patterns (Park et al, 2005;Chae et al, 2006;Lee et al, 2007).…”

“…This finding is in part because of a high incidence of fetal death that is due to a variety of afflictions during pregnancy, including fetal overgrowth and placental malformations (Hiendleder et al, 2004;Arnold et al, 2006;Chae et al, 2006;Lee et al, 2007). These studies have revealed that some of the subtle abnormalities of adult scNT-derived animals are species-specific.…”

Comparative Proteomic Analysis of Liver Mitochondrial Proteins Derived from Cloned Adult Pigs Reconstructed with Meishan Pig Fibroblast Cells and European Pig Enucleated Oocytes

“…Accordingly, many abnormalities observed in SCNT fetuses and offspring may be influenced by deficiencies in mitochondrial function. Recently, comparative proteomic analyses of SCNT piglets and placentae from SCNT pigs were reported [18][19][20]35]. Two-dimensional gel electrophoresis analysis revealed changes in the responses of several detoxification-related proteins to stress and inflammation in sudden death observed in SCNT piglets with extensive hepatopneumonic apoptosis [17].…”

“…Two-dimensional gel electrophoresis analysis revealed changes in the responses of several detoxification-related proteins to stress and inflammation in sudden death observed in SCNT piglets with extensive hepatopneumonic apoptosis [17]. Lee et al [18] assessed the global protein expression profiles in term placentas from SCNT pigs and found that the proteins closely involved in the apoptotic signaling pathway were different in comparison with controls. In malformed umbilical cords of SCNT piglets, proteins prevention of oxidative stress were downregulated, while molecules involved in apoptosis were upregulated [20].…”

“…Recently, global comparative proteomic analysis was performed to identify the proteins that cause problems in animal cloning [17][18][19][20]. Different expression levels in disease-relevant proteins and/or in apoptosis were observed in piglets, fetuses and placentae of offspring derived from SCNT pigs [17][18][19][20].…”