Global array-based transcriptomics from minimal input RNA utilising an optimal RNA isolation process combined with SPIA cDNA probes

Laser capture microdissection: Big data from small samples

Any tissue is made up of a heterogeneous mix of spatially distributed cell types. In response to any (patho) physiological cue, responses of each cell type in any given tissue may be unique and cannot be homogenized across cell-types and spatial co-ordinates. For example, in response to myocardial infarction, on one hand myocytes and fibroblasts of the heart tissue respond differently. On the other hand, myocytes in the infarct core respond differently compared to those in the peri-infarct zone. Therefore, isolation of pure targeted cells is an important and essential step for the molecular analysis of cells involved in the progression of disease. Laser capture microdissection (LCM) is powerful to obtain a pure targeted cell subgroup, or even a single cell, quickly and precisely under the microscope, successfully tackling the problem of tissue heterogeneity in molecular analysis. This review presents an overview of LCM technology, the principles, advantages and limitations and its down-stream applications in the fields of proteomics, genomics and transcriptomics. With powerful technologies and appropriate applications, this technique provides unprecedented insights into cell biology from cells grown in their natural tissue habitat as opposed to those cultured in artificial petri dish conditions.

A novel minimally-invasive method to sample human endothelial cells for molecular profiling

Objective

The endothelium is a key mediator of vascular homeostasis and cardiovascular health. Molecular research on the human endothelium may provide insight into the mechanisms underlying cardiovascular disease. Prior methodology used to isolate human endothelial cells has suffered from poor yields and contamination with other cell types. We thus sought to develop a minimally invasive technique to obtain endothelial cells derived from human subjects with higher yields and purity.

Methods

Nine healthy volunteers underwent endothelial cell harvesting from antecubital veins using guidewires. Fluorescence-activated cell sorting (FACS) was subsequently used to purify endothelial cells from contaminating cells using endothelial surface markers (CD34 / CD105 / CD146) with the concomitant absence of leukocyte and platelet specific markers (CD11b / CD45). Endothelial lineage in the purified cell population was confirmed by expression of endothelial specific genes and microRNA using quantitative polymerase chain reaction (PCR).

Results

A median of 4,212 (IQR: 2161 – 6583) endothelial cells were isolated from each subject. Quantitative PCR demonstrated higher expression of von Willebrand Factor (vWF, P<0.001), nitric oxide synthase 3 (NOS3, P<0.001) and vascular cell adhesion molecule 1 (VCAM-1, P<0.003) in the endothelial population compared to similarly isolated leukocytes. Similarly, the level of endothelial specific microRNA-126 was higher in the purified endothelial cells (P<0.001).

Conclusion

This state-of-the-art technique isolates human endothelial cells for molecular analysis in higher purity and greater numbers than previously possible. This approach will expedite research on the molecular mechanisms of human cardiovascular disease, elucidating its pathophysiology and potential therapeutic targets.