Abstract 17277: Myocardial Rescue by Mesenchymal Stem Cell via Tunneling Nanotube Formation
Objectives: Mesenchymal stem cell (MSC) shows promising therapeutic potentials for heart diseases in numerous animal studies and clinical trials. The cardiogenic transdifferentiation and paracrine factors delivery of MSCs are generally accepted mechanisms for myocardial rescue. Recent studies suggest that the rescue may also be achieved by direct delivery of subcellular organelles such as mitochondria. Tunneling nanotube (TNT) formation between MSCs and various damaged cell types has been observed both in vitro and in vivo for assisting organelle transfer. Based on our recent observation in a cell patterning-based in vitro assay, it is found that mitochondria are transferred from MSCs to neonatal cardiomyocytes (NCMs) through TNTs to enhance myocyte survival. Adequate investigation of hetero-paired TNTs is hampered by their random formation in standard cell culture and the difficulty of capturing them in vivo. Accordingly, a PDMS (polydimethylsiloxane) biochip-based coculture model was microfabricated to enable more consistent examination of TNT formation and mitochondrial transfer.
Methods: Rat MSC (GFP tagged in green) and 3-day NCMs (w or w/0 treatment of 1 μg/ml lipopolysaccharide (LPS)) were introduced into a two-channel microfluidics-based biochip (Figure 1A) microfabricated with PDMS, and TNTs were guided to form in microchannels between the two cell types. The numbers of TNT formed between MSC and LPS treated or untreated NCM were counted per biochip after 24 hours coculturing. Then the sample was stained with annexin V to evaluate the cardiac stress of NCMs.
Results and Discussion: It was observed that mitochondria were transferred unidirectionally from MSCs to NCMs via TNT (Figure 1B), irrespective of the TNT’s direction of formation. NCMs in stressed conditions triggered more TNT formation in red of annexin V staining with MSCs than the control (Figure 1C). It suggests that a rescue effect may be produced by TNT-mediated mitochondrial transfer.
Author Disclosures: H. Yang: None. R.B. Runyan: None. T.K. Borg: None. R. Markwald: None. M. Xu: None. B.Z. Gao: None.
This research has received full or partial funding support from the American Heart Association
- © 2014 by American Heart Association, Inc.