Dr. Pika Miklavc

My research focuses on cell biology of secretion. One example are cellular mechanisms of surfactant secretion in lung alveoli and their disruption in pulmonary disease. This research investigates the molecular basis of surfactant secretion in lung alveoli and dysfunctional surfactant secretion in pulmonary disease. Surfactant is a hydrophobic substance that enables breathing and is secreted from alveolar type II cells into alveolar lumen via exocytosis. Exocytosis is an intracellular trafficking process where a secretory vesicle undergoes fusion with the plasma membrane to release vesicle contents form the cell. Surfactant deficiency can cause infant respiratory distress syndrome and pulmonary fibrosis; however, the molecular mechanisms of surfactant secretion in health and disease are not well known. Surfactant secretion is investigated using cell culture of lung epithelial cell lines and live cell fluorescence microscopy. 

The second example are mechanisms and function of extracellular vesicle (EV) and miRNA secretion. This research compares the secretion of EVs and miRNA in cell models of lung and brain cancer by using fluorescent labelling of EVs in living cells. EVs are small extracellular vesicles that play a role in cell-cell communication. Communication between cells is essential for normal function of tissues and organs in multicellular organisms and chemical messengers such as hormones, transmitters, growth factors and cytokines have been researched in considerable detail. However, recent studies show that cells can also communicate though EVs. EVs are continuously released from cells and contain genetic material, proteins and lipids that can influence gene expression and induce phenotypic changes in recipient cells. The mechanisms of EV secretion are not yet clear and are the focus of this project. MiRNAs on the other hand are small non-coding RNA which usually downregulate the expression of their target mRNAs. The role of miRNA in cancer has been well documented and it was proposed that secreted extracellular miRNA may function in a manner similar to hormones. Secreted miRNAs can be free or enclosed in exosomes; however, the triggers of miRNA secretion are poorly understood.