Very small embryonic-like stem cells aka VSELs are reported to be tiny adult stem cells that are pluripotent or non-existent depending on whom you talk to most recently or which paper you just read.
These very controversial cells (which I once compared to the Sasquatch) have a wildly fluctuating history with their existence on multiple occasions apparently being proven and then later disproven. The latter fate of them being not existing was most recently shown rather convincingly by Irv Weissman’s lab and the former fate of them being real most recently is shown in new papers published in the journal Stem Cells and Development including one by primary VSEL proponent, Dr. Mariusz Z. Ratajczak. This issue also included a letter from VSEL skeptic Jozef Dulak.
BTW note the very cool Pink Floyd Dark Side of the Moon-Inspired acid trip-like Cover Image of the Stem Cells and Development journal representing VSEL multipotency. I haven’t had a chance to read these new VSEL papers yet so I cannot say any thoughts on them specifically as of yet.
But more broadly could the crazy roller coaster VSEL history predict the future of STAP cells?
I think it might and many VSEL-related events lead me to ask questions about STAP.
Could Dr. Charles Vacanti (the main remaining defender of STAP) have a future role as the longer term primary defender of STAP cells that parallels Ratajczak’s role on VSELs?
Could there be a STAP company akin to the biotech NeoStem, which works on VSELs?
Could such a STAP company already exist or be in the germinal stages via investors who might have pumped in millions of dollars into STAP?
Might we expect a helter-skelter VSEL-like future for STAP cells with a series of papers alternately claiming their existence or debunking them?
The answers to these questions will come over time, but I think there may be many important parallels between the history of VSELs and the future of STAP.
Endogenous postnatal pluripotent stem cells EXIST. I have known about pluripotent stem cells since 1995 when I isolated homogenous populations of them from single cells using repetitive serial dilution clonogenic analysis. I have spent from 1988 to the present characterizing pluripotent stem cells and other types of stem cells versus progenitor cells derived from postnatal individuals, i.e., mice, rats, cats, dogs, sheep, goats, pigs, cows, horses and humans. For particulars please see: Clonogenic analysis reveals reserve stem cells in postnatal mammals. II. Pluripotent epiblastic-like stem cells. Anat. Rec. 277A:178-203, 2004; Adult reserve stem cells and their potential for tissue engineering. Cell Biochem Biophys, 40(1):1-80, 2004; Adult stem cells. Anat. Rec. 276A:75-102, 2004; Karyotypic analysis of adult pluripotent stem cells. Histology and Histopathology, 20: 769-784, 2005; Adult-derived stem cells and their potential for tissue repair and molecular medicine. J Cell Molec Med 9:753-769, 2005; Adult-derived stem cells. Minerva Biotechnologica 17:55-63, 2005; Naturally occurring adult pluripotent stem cells. In: Stem Cells: From Biology to Therapy, Advances in Molecular Biology and Medicine. 1st Ed, R.A. Meyers, Ed, WILEY-BLACKWELL-VCH Verlag GmbH & Co. KGaA. Chap 3, pp. 63-93, 2013. The size of VSELs, 3-5 microns, is in the range (2-10 microns) of multiple populations of pluripotent stem cells that my lab has isolated and characterized. And no, I am not a collaborator of Dr. Mariusz Z. Ratajczak. Actually, we are competitors. He has his VSELs, and I have my BLSCs, ELSCs, HLSCs, CLSCs, and GLSCs.
More like cold fusion to me