cytocentric visionaries dp p2Cytocentric Visionaries: Donald Phinney

Part Two: MSC vs Exosomes and Therapies

In Part One, Chief Scientific Officer Alicia Henn talks with Dr. Phinney about his publication in Nature Communications, ”Mesenchymal stem cells use extracellular vesicles to outsource mitophagy and shuttle microRNAs”[Phinney et al., 2015]. Here we continue that conversation and discuss why exosomes have an advantage over MSC cells (interview edited for length).

cytocentric visionaries dp p1Cytocentric Visionaries: Donald Phinney, Chair Department of Molecular Therapeutics, The Scripps Research Institute

Part One: Mesenchymal Stem Cells, as Healers, Aren’t So Selfless

Chair of the Molecular Therapeutics Department at Scripps, Dr. Phinney has almost 20 years of experience in the adult stem cell field and has been an editor of prominent stem cell journals. Here, Alicia Henn talks with Dr. Phinney about his latest publication in Nature Communications, ”Mesenchymal stem cells use extracellular vesicles to outsource mitophagy and shuttle microRNAs”[Phinney et al., 2015]. This conversation on understanding how MSC stem cells affect macrophage biology was edited for length.

Phinney and his co-authors reported that in response to oxidative stress, MSCs export damaged mitochondria to nearby macrophages, which recycle them for their own bioenergetics. The MSCs also export exosomes containing miRNAs that reduce the inflammatory activities of macrophage through TLR-7 signaling pathways. This benefits the nearby MSCs, and is also a mechanism by which MSCs may have their clinical effects on surrounding tissues.

Gas Control in Semi-sealed Chambers

Dalton in the Incubator

bp035 c21 CchamberWe are all familiar with how CO2 is infused into cell culture incubators to raise CO2 to physiologic levels and keep carbonic acid based media in the proper pH range for cells. However, managing a system for a gas infusion system necessitates understanding how mixed gases work in a semi-sealed cell incubator chamber.

bp34 image001Temperature, CO2, and pH in Cell Culture Media

What Seems Best for Incubation is Not Always Best for Handling

Most, but not all, cell culture media contain carbonate-based buffers which work with elevated gaseous carbon dioxide levels in the incubator to stabilize cell culture pH (see figure).  Carbonate-based buffers are present in vivo and so seem like an obvious choice for physiologically relevant incubation conditions. However, carbonate-based buffers can create non-optimal conditions for cultures during cell culture handling outside of the incubator. The critical cell parameters of temperature and carbon dioxide levels can affect carbonate buffered cell media. Continue reading to learn about the importance of having a cell culture growth medium during incubation.

Top 5 Cytocentric Publications of 2015

Overall, 2015 was a big year for moving cytocentric research forward. Some publications have stood out from the rest as impactful. The authors of these papers not only used cytocentric principles in carrying out their experiments, but their findings and language help describe a new scientific era of more physiologically relevant in vitro cell systems. Check out our list below to discover the top 5 publications for cell-focused research in 2015.