Honey bee Royalactin unlocks conserved pluripotency pathway in mammals
Authors: Cole M Dovey
Derrick C Wan
Jan E Carette
Dana Huh
Andrew L Spencley
Hua Tu
Jennifer Lumb
Marco Quarta
Roel Nusse
Jordon Wang
Star K Huynh
Katharine V Brown
Erin Y Chang
Natasha Mariano
Victoria L Mascetti
Jasmine M Garcia
Richard Luong
Kevin C Wang
Sharon J Pitteri
J Fernando Bazan
Vittorio Sebastiano
Thomas A Rando
Hong Zeng
Gautam Shankar
Yunhai Luo
Abel Bermudez
Ling Liu
Stefanie L Morgan
Ted H Li
Journal: Nature Communications (2018)
Discipline: Multidisciplinary
Keywords: Royal jelly; Apis mellifera; longevity; fertility; regeneration
Affiliations: Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA., Hagey Laboratory for Pediatric Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA., Program in Cancer Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA., Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA., The Glenn Laboratories for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA., Department of Developmental Biology, Howard Hughes Medical Institute, Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA., Canary Center for Cancer Early Detection, Department of Radiology, Stanford University School of Medicine, Palo Alto, CA, 94304, USA., Department of Comparative Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA., Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA., LakePharma, Inc., Belmont, CA, 94002, USA., R&D Systems, Inc, Minneapolis, MN, 55413, USA., Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA. ., Program in Cancer Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA. ., Veterans Affairs Palo Alto Healthcare System, Palo Alto, CA, 94304, USA. .

Abstract:  Royal jelly is the queen-maker for the honey bee Apis mellifera, and has cross-species effects on longevity, fertility, and regeneration in mammals. Despite this knowledge, how royal jelly or its components exert their myriad effects has remained poorly understood. Using mouse embryonic stem cells as a platform, here we report that through its major protein component Royalactin, royal jelly can maintain pluripotency by activating a ground-state pluripotency-like gene network. We further identify Regina, a mammalian structural analog of Royalactin that also induces a naive-like state in mouse embryonic stem cells. This reveals an important innate program for stem cell self-renewal with broad implications in understanding the molecular regulation of stem cell fate across species. 

Retracted: No

PubPeer comments:
 This paper makes a pretty remarkable claim that a protein from bee royal jelly called  Royalactin is able to substitute for the mammalian cytokine leukemia inhibitory factor (LIF) in the culture of murine embryonic stem cells. This finding is unprecedented and would have major implications especially if Royalactin can be produced cheaply since LIF can be quite expensive to purchase. Given the unprecedented nature of this finding this study absolutely requires independent replication by other groups, and given the interest in mammalian pluripotency I m sure a validation studies are already underway. Looking closely through this paper I observed a number of issues with the figures. There are a number of panel duplications throughout the paper. One instance is the re-use of a set of 4 images in figure 1 and figure 3. https: i.imgur.com SUlKDO8.jpg In addition there is duplication of individual panels in the main figures and the supplemental figures. In these instances the main figures are labelled as 10 passage samples whereas the supp data claims they are passage 3 cells. What s concerning is that in both instances the panels have either been rotated or re-cropped, so it s not a simple copy-paste mistake of the same image. I included boxes to highlight the identical regions. https: i.imgur.com 2upVR8M.jpg https: i.imgur.com dzVAPRD.jpg Another point that seems a bit strange is the chimeric mice shown in figures. The ES cell line that the authors use is from a 129 mouse strain and would therefore have the agouti coat color. In some instances chimeras seem to have been made by injecting these 129 ESCs into C57BL 6 donor blastocysts whereas others use a strain with white coat color (details of the strains used does not seem to be included in the materials and methods). However, in some panels it appears that the mice are a mixture of agouti, black and white coat colors. This shouldn t be possible. Another issue is that the authors claim that they have generated germ line chimeras but provide no actual data to support this. Germ-line transmission is very easy to assay and would only require crossing the chimeric offspring to C57BL 6 mice. Since the agouti gene is dominant, any agouti offspring from this cross would indicate that the ESC can contribute to the germ cell lineage. It s very strange that this experiment isn t included in the paper, generally authors would include photos of the pups from the chimera x C57BL 6 cross. , 
 More of a conceptual criticism rather than a issue with the data in this particular work. A follow up study on the Royalactin protein has shown that it doesn t actually possess the fate determination properties that were originally reported by Kamakura in 2011. Kamakura paper: https: www.ncbi.nlm.nih.gov pubmed 21516106 Follow up by Buttstedt et al. : https: www.ncbi.nlm.nih.gov pubmed 27652566 Buttstedt and colleagues propose that it is in fact sugars present in royalactin preparations that mediate this effect. If royalactin does not possess these attributes in its native species context it s difficult to imagine a model where it has pluripotency promoting properties across different animal phyla. , 
 Another conceptual point. It s well known that different mammalian ESCs (mouse vs. human for instance) require quite different signals to retain pluripotency. The authors don t test if royalactin can support human ESC self-renewal, it would be important to know this. Is royalactin s activity restricted to mouse ESCs and if so, what is the evolutionary implication of this? , 
 Interesting that knockout mice for the mammalian homolog of Royalactin (NHLRC3) show no apparent developmental abnormalities. https: www.mousephenotype.org data genes MGI:2444520 ,