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Brain Bank Bulletin The PDS Tissue Bank is sponsored by the Parkinson's Disease Society

Issue 8 Spring 2007

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This experiment was carried out to determine which of these ante and post-mortem variables affect the quality of RNA. A total of 149 snap frozen tissue samples were used in this analysis which included 70 samples from the UK MS and 32 samples from the UK PD tissue banks and 47 snap frozen tissue samples from Brain Net Europe participants. These 47 samples were provided by Barcelona (8 samples), Edinburgh (5 samples), Institutes of Psychiatry London (8 samples), Wuerzburg (8 samples), Paris (8 samples) and Munich (10 samples).

RNA was extracted from all the samples using a special kit, utilising methods previously optimised for the network. RNA quantity and quality was assessed using a piece of specialised equipment, the Agilent Bioanalyser. The data obtained was analysed against predetermined variables. As the information supplied by a majority of the participants was limited to:

• Age;
• Gender;
• Post Mortem (PM) delay;
• Disease type;
• Cerebral Spinal Fluid pH and;
• Freezer interval.

These were used as the main factors against which the quality of RNA was analysed. The statistical analysis of the data was carried out with advice and support from the Imperial College Statistical Advisory Service.

Results:
This initial analysis suggests that gender, age, post-mortem delay, freezer interval and CSF pH do not have a significant effect on the quality of RNA. From these observations it can be concluded that it is possible to isolate adequate concentrations of good quality RNA from human post-mortem brain tissue even with longer PM delays and freezer intervals. Although variation in the quality of RNA between samples was observed, the factors analysed could not account for this variation. These results mean that the way tissue is currently being collected by the Tissue Banks, the method of storing, and PM delay times are appropriate to allow use of the tissue in molecular studies.

Future Research:
We plan to carry out a prospective study by obtaining tissue samples from ten postmortem brains from each of the brain banks that participated in this experiment. Also in the future we plan to carry out the first micro-array study to look at gene expression levels across diseases using the same test procedures. Gene expression analysis looks at which genes maybe 'switched on' or 'switched off' more in disease processes. In the past gene expression studies have been carried out on individual diseases like PD but this study will not only look at PD but also MS, Alzheimer's disease, Huntington's disease, Schizophrenia, Amyotrophic Lateral Sclerosis at the same time to see whether common gene changes occur in several diseases. This may help identify whether certain drug treatments may be effective in more than one disease.

Dr Francisca S Fernando Research Associate