No abstract

Exercise is known to upregulate mRNA synthesis for carnitine palmitoyl transferase1 (CPT1) and possibly also other mitochondrial carnitine acyltransferases in muscle tissue. The aim of this study was to test whether such an adaptation of oxidative metabolism in skeletal muscle is a systemic process and consequently, also affects other cells. Messenger RNA levels of five genes [carnitine palmitoyl transferases 1 and 2 (CPT1 and CPT2), carnitine acetyltransferase (CRAT), carnitine palmitoyltransferase 2 (CPT2), microsomal carnitine palmitoyltransferase (GRP58) and organic cation transporter (OCTN2)] were determined with quantitative real time polymerase chain reaction (PCR) in blood cells and in muscle biopsy samples from six cross country skiers before and 6 months after a high volume/low intensity exercise training, when training had elicited a significantly slower rate of lactate accumulation. Quantitative real time PCR showed that levels of mRNA in blood cells correlated significantly (CPT1B: P< 0.001) with those in muscle tissue from the same donors. After 6-months training, there was a 15-fold upregulation of CPT1B mRNA, a six to ninefold increase of CRAT mRNA, of CPT2 mRNA, GRP58 mRNA, and of OCTN2 mRNA. The observation of a concordant stimulation of CPT1, CPT2, CRAT, GRP58 and OCTN2 transcription in blood cells and muscle tissue after 6-month-endurance training leads the hypothesis of a common stimulation mechanism other than direct mechanical stress or local chemical environment, but rather humoral factors.

Transplantation of autologous hematopoietic stem cells is a well established therapeutic procedure. Despite advances in efficacy of the stem cell mobilization and apheresis process until now a predictive factor for the expected stem cell yield before initiation of mobilization therapy could not be identified. The main objective of our study was to evaluate alterations in enzymes involved in fatty acid metabolism on the level of gene expression in mononuclear cells, as changes in relative mRNA levels of these enzymes could represent the hematopoietic regenerative potential. Data of 23 consecutive patients with different lymphoid malignancies undergoing stem cell mobilization were analyzed. Our results show that mRNA levels of microsomal carnitine palmitoyltransferase in peripheral blood mononuclear cells quantified before application of mobilization therapy correlate positively with the amount of CD34 positive cells in peripheral blood before first apheresis, in the first apheresis product and in the total harvest outcome. The association of enzymes involved in fatty acid metabolism with hematoopoiesis was further confirmed in healthy subjects on altitude-adaptation training and in proliferating or differentiating HL60 cells. This gives evidence for a possible predictive value of such analyzes though further data of a larger sample are to be collected to confirm our observations.