ACMD Seminar: The importance of mitochondrial fission and fusion in a beating heart cell

Adarsh Kumbhari
University of Sydney, Australia

Thursday, October 18, 15:00 - 16:00
Building 101 Lecture Room B
Gaithersburg

Thursday, October 18, 13:00 - 14:00
Building 1 Room 4072
Boulder

Host: Tony Kearsley

Abstract: Mitochondria are specialised organelles that produce adenosine triphosphate (ATP) a molecule used by cells as an energy source. Owing to its unique energetic demands, cardiomyocytes have evolved to have a high mitochondrial density. These mitochondria form dynamic networks that are constantly undergoing fission and fusion events in response to a variety of stressors such as increased ATP demand or oxidative stress.  

However, the precise bioenergetic roles that mitochondrial fission and fusion play are unknown. This is further complicated by a lack of high-resolution data tracking the reorganisation mitochondrial networks in a beating heart cell. Previously, it was shown that mitochondria may split in an attempt to minimise the propagation of local dysfunction. 

Here, we use a hybrid agent-based-PDE model to quantify how different fission and fusion rates impact the distribution of ATP. We find that in normoxic regimes, varied fusion and fusion rates do not result in substantial changes in ATP production. By contrast, increased rates of mitochondrial fusion in hypoxic regimes are associated with more homogenous but reduced levels of ATP. Our findings suggest that the role of mitochondrial fission and fusion might be to assist in ensuring ATP homogeneity in hypoxic regimes.

Bio: Adarsh Kumbhari is a second-year PhD student specialising in mathematical biology at the University of Sydney, Australia under the supervision of Peter Kim. His current research focuses on modelling cancer-immune interactions and mitochondrial networks using a combination of agent-based models, ordinary differential equations, and partial differential equations.

Note: Visitors from outside NIST must contact Cathy Graham; (301) 975-3800; at least 24 hours in advance.