Stacey J Ellery1, Paul A Della Gatta2, Clinton R Bruce2, Greg M Kowalski2, Miranda Davies-Tuck1, Joanne C Mockler3, Padma Murthi4, David W Walker1, Rod J Snow2, Hayley Dickinson5. 1. The Ritchie Centre, Hudson Institute of Medical Research, Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia. 2. Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood Campus, Melbourne, Australia. 3. Department of Obstetrics and Gynaecology, Monash University & Monash Health, Melbourne, Australia. 4. The Ritchie Centre, Hudson Institute of Medical Research, Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia; Department of Medicine, School of Clinical Sciences, Monash University, Monash Medical Centre, Clayton, Australia. 5. The Ritchie Centre, Hudson Institute of Medical Research, Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia. Electronic address: Hayley.Dickinson@hudson.org.au.
Abstract
INTRODUCTION: Creatine is an amino acid derivative that is involved in preserving ATP homeostasis. Previous studies suggest an important role for the creatine kinase circuit for placental ATP turnover. Creatine is obtained from both the diet and endogenous synthesis, usually along the renal-hepatic axis. However, some tissues with a high-energy demand have an inherent capacity to synthesise creatine. In this study, we determined if the term human placenta has the enzymatic machinary to synthesise creatine. METHODS: Eleven placentae were collected following elective term caesarean section. Samples from the 4 quadrants of each placenta were either fixed in formalin or frozen. qPCR was used to determine the mRNA expression of the creatine synthesising enzymes arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), and the creatine transporter (SLC6A8). Protein expression of AGAT and GAMT was quantified by Western blot, and observations of cell localisation of AGAT, GAMT and SLC6A8 made with immunohistochemistry. Synthesis of guanidinoacetate (GAA; creatine precursor) and creatine in placental homogenates was determined via GC-MS and HPLC, respectively. RESULTS: AGAT, GAMT and SLC6A8 mRNA and protein were detected in the human placenta. AGAT staining was identified in stromal and endothelial cells of the fetal capillaries. GAMT and SLC6A8 staining was localised to the syncytiotrophoblast of the fetal villi. Ex vivo, tissue homogenates produce both GAA (4.6 nmol mg protein-1h-1) and creatine (52.8 nmol mg protein-1h-1). DISCUSSION: The term human placenta has the capacity to synthesise creatine. These data present a new understanding of placental energy metabolism.
INTRODUCTION:Creatine is an amino acid derivative that is involved in preserving ATP homeostasis. Previous studies suggest an important role for the creatine kinase circuit for placental ATP turnover. Creatine is obtained from both the diet and endogenous synthesis, usually along the renal-hepatic axis. However, some tissues with a high-energy demand have an inherent capacity to synthesise creatine. In this study, we determined if the term human placenta has the enzymatic machinary to synthesise creatine. METHODS: Eleven placentae were collected following elective term caesarean section. Samples from the 4 quadrants of each placenta were either fixed in formalin or frozen. qPCR was used to determine the mRNA expression of the creatine synthesising enzymes arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), and the creatine transporter (SLC6A8). Protein expression of AGAT and GAMT was quantified by Western blot, and observations of cell localisation of AGAT, GAMT and SLC6A8 made with immunohistochemistry. Synthesis of guanidinoacetate (GAA; creatine precursor) and creatine in placental homogenates was determined via GC-MS and HPLC, respectively. RESULTS:AGAT, GAMT and SLC6A8 mRNA and protein were detected in the human placenta. AGAT staining was identified in stromal and endothelial cells of the fetal capillaries. GAMT and SLC6A8 staining was localised to the syncytiotrophoblast of the fetal villi. Ex vivo, tissue homogenates produce both GAA (4.6 nmol mg protein-1h-1) and creatine (52.8 nmol mg protein-1h-1). DISCUSSION: The term human placenta has the capacity to synthesise creatine. These data present a new understanding of placental energy metabolism.
Authors: Anthony L Su; Sean M Harris; Elana R Elkin; Alla Karnovsky; Justin A Colacino; Rita Loch-Caruso Journal: Reprod Toxicol Date: 2022-03-15 Impact factor: 3.143
Authors: Stacey J Ellery; Padma Murthi; Paul A Della Gatta; Anthony K May; Miranda L Davies-Tuck; Greg M Kowalski; Damien L Callahan; Clinton R Bruce; Euan M Wallace; David W Walker; Hayley Dickinson; Rod J Snow Journal: Int J Mol Sci Date: 2020-01-26 Impact factor: 5.923
Authors: Anna Maria Muccini; Nhi T Tran; Deborah L de Guingand; Mamatha Philip; Paul A Della Gatta; Robert Galinsky; Larry S Sherman; Meredith A Kelleher; Kirsten R Palmer; Mary J Berry; David W Walker; Rod J Snow; Stacey J Ellery Journal: Nutrients Date: 2021-02-02 Impact factor: 5.717
Authors: Nhi Thao Tran; Sharmony B Kelly; Rod J Snow; David W Walker; Stacey J Ellery; Robert Galinsky Journal: Cells Date: 2021-10-27 Impact factor: 6.600