Top 5 Cytocentric Papers of 2016
In this post we highlight the top publications of 2016 that illustrate the Cytocentric approach to cell and tissue culture. Here I specifically excluded papers in the field of Immunology because we will soon be publishing a separate post to highlight Cytocentric Immunology papers of 2016. Let’s count down the best of 2016:
Low Oxygen Modulates Multiple Signaling Pathways Increasing Self-Renewal while Decreasing Differentiation, Senescence and Apoptosis in Stromal MIAMI Cells.This paper in Stem Cells and Development  (paywalled), Rios et al pull together multiple pathways affected by culture oxygen levels in a subtype of immature MSC called marrow-isolated adult multilineage inducible (MIAMI) cells. Their comparison of 21% and 3% oxygen for MIAMI cell culture helped elucidate how specific signal transduction mechanisms produce the observed profound effects of oxygen on cell cycle and differentiation.
It is a small point, but one of the best things about this paper is that the researchers grew the cells for 7 days at physiologically relevant oxygen before their measurements. It has been a frequent disappointment to read a paper that promised results in physiologically relevant culture to find that the reseachers only had their cells in the appropriate conditions for 24 hours (or less!) before their endpoints. The use of these short incubation times is misleading in that it gives us a snapshot of cells in transition to their new environment rather than a steady-state. The authors of this paper understand oxygen biology enough to avoid this mistake and have contributed a key piece to our picture of how culture oxygen levels affect stem cells.
Culturing Human Pluripotent and Neural Stem Cells in an Enclosed Cell Culture System for Basic and Preclinical Research.
Stover et al. published this wonderful methods paper in the JoVE . They grew their cells in the closed Xvivo System X2. Their approach to controlling conditions around their cells full-time, using a cell handling space that is truly separated from room air, allowed them to use physiologically relevant oxygen conditions.
The use of unbroken physiologic simulation for pre-clinical work is critical for reducing variability between technicians and between laboratories. Dramatic swings in CO2 and oxygen levels are experienced by cells when they are moved back and forth from an oxygen-controlled incubator to a room air biological safety cabinet for handling. HIF-1 protein levels change on the order of minutes when oxygen levels shift and pH rapidly goes out of optimum when CO2 levels are not maintained. Well-controlled conditions for pre-clinical work necessitate constant control of conditions, even during cell handling.
Another great thing about this paper is that this group is thinking ahead and setting up their pre-clinical work for the best chance at translation into in vivo studies. It is a waste of time and money to do pre-clinical studies in irrelevant conditions.
Human Cells Cultured Under Physiological Oxygen Utilize Two Cap-binding Proteins to Recruit Distinct mRNAs for Translation.
In this paper in JBC , Timpano et al explored the molecular mechanism underlying the differences between cells handled under physioxic and supraphysioxic conditions. This group, at University of Guelph, found that fundamentally different machinery is used for the basic process of translation under the two different conditions. This novel work is absolutely essential for our understanding of not only the effect of room air on cells, but also our ability to assess the value of any findings generated in supraphysiologic oxygen.
The use of the words “physioxia” and “physioxic” by the authors also helps promote a more scientifically valid terminology. We heartily approve. Physiologic simulation as well as the best terminology to describe it should be used universally. See our interview here with senior author Jim Uniacke, a rising star in physiologically relevant research.
Quantifying the magnitude of the oxygen artefact inherent in culturing airway cells under atmospheric oxygen versus physiological levels.
This paper in FEBS Letters describes the stark differences in responses of human lung cells to air pollutants when cultured in room air rather than physiologically relevant oxygen conditions.  Physiologically relevant conditions for in vitro toxicology should be a given for meaningful results and straight-forward translation to in vivo studies. However, most cell-based toxicological studies are still being performed in the supraphysiologic oxygen of room air.
See our interview here withsenior author Dr. Ian Mudway of King’s College, in which he talks about how hard it was to get this work published. He found a lot of resistance from reviewers to reporting problems with widely accepted traditional cell culture techniques. His group started with the lack of correlation between in vivo and in vitro findings for basic pollution toxicology.They were eventually able to document that the supraphysiologic oxygen was imposing additional stress to the cells which can account for the differences.
It is going to take a broader awareness of this issue to get the widespread adoption of Cytocentric conditions for cells and tissues. However, changing the way the world grows and handles cells is exactly what is needed to get better understanding of the relevant biology.
And the #1 Cytocentric Publication for 2016
cGMP production of patient-specific iPSCs and photoreceptor precursor cells to treat retinal degenerative blindness.
This landmark publication in Scientific Reports  details the cGMP production of iPSC and retinal stem cells in a Cytocentric Xvivo System. Protection of highly valuable patient-specific cells from microbial contamination could not be more important. Here, the group under Budd Tucker reported on the production patient-specific stem cells using the most advanced technology to protect cells from risky room air bioburden.
Their method is a brilliant application of barrier isolator technology to push novel cell therapeutics closer to the clinic. New treatment options for patients suffering from retinal degenerative diseases are one big step closer to reality because of this work.
One prediction for next year: We will see many more publications of cGMP Cytocentric cell production.
1. Rios, C., et al., Low Oxygen Modulates Multiple Signaling Pathways Increasing Self-Renewal while Decreasing Differentiation, Senescence and Apoptosis in Stromal MIAMI Cells. Stem Cells Dev, 2016.
2. Stover, A.E., et al., Culturing Human Pluripotent and Neural Stem Cells in an Enclosed Cell Culture System for Basic and Preclinical Research. J Vis Exp, 2016(112).
3. Timpano, S. and J. Uniacke, Human Cells Cultured Under Physiological Oxygen Utilize Two Cap-binding Proteins to Recruit Distinct mRNAs for Translation. J Biol Chem, 2016.
4. Kumar, A., et al., Quantifying the magnitude of the oxygen artefact inherent in culturing airway cells under atmospheric oxygen versus physiological levels. FEBS Lett, 2016. 590(2): p. 258-69.
5. Wiley, L.A., et al., cGMP production of patient-specific iPSCs and photoreceptor precursor cells to treat retinal degenerative blindness. Sci Rep, 2016. 6: p. 30742.