Analysis of De Novo Telomere Addition by Southern Blot

The effect of pre-operative autologous blood donation on bone marrow hematopoietic functions in rabbits after hepatectomy

BACKGROUND

Pre-operative autologous blood donation (PABD) is one of the most widely distributed autologous blood donation means, which has positive effect on erythropoiesis. However, whether PABD can stimulate the bone marrow hematopoiesis after hepatectomy have not been reported.

METHODS

Totally 80 New Zealand rabbits were randomly divided into 4 groups that included control group, surgery group, hemodilutional autotransfusion (HA) group and PABD group. Automatic reticulocyte examination was performed to detect the content of reticulocyte and immature reticulocyte fractions (IRF). Flow cytometric analysis was employed to monitor the level of CD34+ cells and the cell cycle status. Southern blotting was conducted to determine the telomere length of CD34+ cells.

RESULTS

The content of high fluorescence reticulocytes (HFR) and IRF was decreased at 6 h and 24 h after autotransfusion. However, the level of CD34+ cells was upregulated after PABD. Cell cycle status analysis revealed that majority of the CD34+ cells in HA and PABD group were maintained in G0/G1 phase. The telomere length in HA and PABD group was shorten than that of control group and surgery group.

CONCLUSION

PABD could promote the bone marrow hematopoietic functions in rabbits after hepatectomy via stimulating proliferation of CD34+ cells and shortening the telomere length of CD34+ cells, but the content of HFR was not increased immediately because of the stuck of CD34+ cells in G0/G1 phase.

The telomere world and aging: Analytical challenges and future perspectives

Telomeres, the terminal nucleoprotein structures of eukaryotic chromosomes, play pleiotropic functions in cellular and organismal aging. Telomere length (TL) varies throughout life due to the influence of genetic factors and to a complex balancing between "shortening" and "elongation" signals. Telomerase, the only enzyme that can elongate a telomeric DNA chain, and telomeric repeat-containing RNA (TERRA), a long non-coding RNA involved in looping maintenance, play key roles in TL during life. Despite recent advances in the knowledge of TL, TERRA and telomerase activity (TA) biology and their measurement techniques, the experimental and theoretical issues involved raise a number of problems that should carefully be considered by researchers approaching the "telomere world". The increasing use of such parameters - hailed as promising clinically relevant biomarkers - has failed to be paralleled by the development of automated and standardized measurement technology. Consequently, associating given TL values to specific pathological conditions involves on the one hand technological issues and on the other clinical-biological issues related to the planning of clinically relevant association studies. Addressing these issues would help avoid major biases in association studies involving TL and a number of outcomes, especially those focusing on psychological and bio-behavioral variables. The main challenge in telomere research is the development of accurate and reliable measurement methods to achieve simple and sensitive TL, TERRA, and TA detection. The discovery of the localization of telomeres and TERRA in cellular and extracellular compartments had added an additional layer of complexity to the measurement of these age-related biomarkers. Since combined analysis of TL, TERRA and TA may well provide more exhaustive clinical information than a single parameter, we feel it is important for researchers in the various fields to become familiar with their most common measurement techniques and to be aware of the respective merits and drawbacks of these approaches.