We use advanced three-dimensional (3D) microscopy imaging techniques to investigate cell signaling and its downstream effects
across a variety of tissues, including the brain, clinical tumor samples, primary cell cultures, established cell lines, and
stem cells. Our research integrates novel tissue preparation protocols, state-of-the-art imaging technologies, and cutting-edge
genetic tools to study key biological phenomena such as neuronal circuits, spatial transcriptional expression, intratumoral
heterogeneity, cancer stem cells, epithelial-mesenchymal transition (EMT), cell division, differentiation, and cellular
migration and networking. To advance these efforts, we are continuously developing and refining tissue processing methods and
3D imaging approaches that enable high-resolution visualization of whole brains, intact tumors, and complex tissue architectures.
Whole-brain imaging
The phrase “seeing is believing” dates back at least to the 17th century and highlights the idea that visual evidence
is one of the strongest forms of understanding. In our work, we aim to make the invisible visible by developing new 3D imaging
methods. We are creating novel tissue preparation protocols and labeling techniques to enable multiplexed imaging of large
numbers of RNA transcripts. Our TRISCO method allows whole-brain visualization of triplexed RNA transcripts with high spatial
resolution. The movie shows a 3D rendering of the entire brain from an 8-week-old adult mouse, stained using TRISCO to label
cortical interneuron transcripts: Somatostatin (Sst mRNA, red), Parvalbumin (Pvalb mRNA, green), and Glutamate
decarboxylase 1 (Gad1 mRNA, blue). Bounding box, 7.7 × 10.6 × 5.5 mm.
Tumor visualisation
Intratumoral heterogeneity is a critical factor
when diagnosing and treating patients with cancer. Marked differences in the genetic and epigenetic backgrounds of cancer
cells have been revealed by advances in genome sequencing, yet little is known about the phenotypic landscape and the
spatial distribution of intratumoral heterogeneity within solid tumours. Here, we show that three-dimensional light-sheet
microscopy of cleared solid tumours can identify unique patterns of phenotypic heterogeneity, in the epithelial-to-mesenchymal
transition and in angiogenesis, at single-cell resolution in whole FFPE biopsy samples. We also show that cleared FFPE
samples can be re-embedded in paraffin after examination for future use, and that our tumour-phenotyping pipeline can
determine tumour stage and stratify patient prognosis from clinical samples with higher accuracy than current diagnostic
methods, thus facilitating the design of more efficient cancer therapies.
Calcium signaling
Calcium is an almost universal intracellular
messenger that controls a vast number of cellular processes spanning from fertilization to cell death. Cells create large
calcium concentration gradients (~10'000 to 1) between the extracellular fluid, cytoplasm, and internal calcium stores by
means of calcium-pumps located in the plasma membrane and in the membranes of internal calcium stores. These gradients
provide ideal conditions for the use of calcium as a cellular currency that supports the propagation of intracellular
calcium waves. The concerted actions of calcium transporters located in the plasma membrane and in the membranes
surrounding internal stores, including the endoplasmic and sarcoplasmic reticulum, the mitochondria, and the nucleus, can
generate calcium oscillations. As with a radio transmitter, cells exploit the two key features of oscillatory signals -
frequency and amplitude - to utilize calcium as a second messenger to generate a large variety of intracellular signals.
This is an efficient way to use the same second messenger to activate many different cell processes.
The Lab
The lab is located on the 6th floor of the Biomedicum research building at the Karolinska Institutet's north campus in
Solna. To study tissue samples we are applying various imaging techniques, such as fluorescence microscopy, confocal
microscopy, 2-photon laser scanning microscopy, and light-sheet microscopy. All imaging setups are available in our
laboratory. The unit is well-equipped in a highly vibrant research community with substantial resources and excellent
core facilities.
Intratumoral heterogeneity is a critical factor
when diagnosing and treating patients with cancer. Marked differences in the genetic and epigenetic backgrounds of cancer
cells have been revealed by advances in genome sequencing, yet little is known about the phenotypic landscape and the
spatial distribution of intratumoral heterogeneity within solid tumours. Here, we show that three-dimensional light-sheet
microscopy of cleared solid tumours can identify unique patterns of phenotypic heterogeneity, in the epithelial-to-mesenchymal
transition and in angiogenesis, at single-cell resolution in whole FFPE biopsy samples. We also show that cleared FFPE
samples can be re-embedded in paraffin after examination for future use, and that our tumour-phenotyping pipeline can
determine tumour stage and stratify patient prognosis from clinical samples with higher accuracy than current diagnostic
methods, thus facilitating the design of more efficient cancer therapies.
Calcium is an almost universal intracellular
messenger that controls a vast number of cellular processes spanning from fertilization to cell death. Cells create large
calcium concentration gradients (~10'000 to 1) between the extracellular fluid, cytoplasm, and internal calcium stores by
means of calcium-pumps located in the plasma membrane and in the membranes of internal calcium stores. These gradients
provide ideal conditions for the use of calcium as a cellular currency that supports the propagation of intracellular
calcium waves. The concerted actions of calcium transporters located in the plasma membrane and in the membranes
surrounding internal stores, including the endoplasmic and sarcoplasmic reticulum, the mitochondria, and the nucleus, can
generate calcium oscillations. As with a radio transmitter, cells exploit the two key features of oscillatory signals -
frequency and amplitude - to utilize calcium as a second messenger to generate a large variety of intracellular signals.
This is an efficient way to use the same second messenger to activate many different cell processes.