What’s interesting in Pubmed this Week: Stem Cells
I’m subscribed to some search feeds at Pubmed. Here’s what caught my eye this week:
Kucia M, Zuba-Surma EK, Wysoczynski M, Wu W, Ratajczak J, Machalinski B, Ratajczak MZ., Adult marrow-derived very small embryonic-like stem cells and tissue engineering. Expert Opin Biol Ther. 2007 Oct;7(10):1499-514. Review. PMID: 17916043 Related Articles
There’s a new source of multi-potent stem cells announced every week, despite the utter absence of an assay that would indicate whether these cells contain the same amount of tissue-repairing activity as established methods. The authors also suggest that because these cells are coming from somewhere in the embryo other than the blastocyst, they’ll be more acceptable to the anti-stem cell crown, but the authors are making the naive, in my opinion, assumption that those who have ethical issues know or care about the difference between epiblast and blastocyst. It’s splitting hairs to someone who mistrusts all reproductive science, period.
A report indicating that “human [Adipose Stem Cells] are epigenetically marked by mosaic hypomethylation of adipogenic promoters, whereas nonadipogenic lineage-specific promoters are hypermethylated.” Methylation status could potentially be a good once-removed assay for reparative activity, but the correlations have not been established so far.
Mouiseddine M, Francois S, Semont A, Sache A, Allenet B, Mathieu N, Frick J, Thierry D, Chapel A., Human mesenchymal stem cells home specifically to radiation-injured tissues in a non-obese diabetes/severe combined immunodeficiency mouse model. Br J Radiol. 2007 Sep;80 Spec No 1:S49-55. PMID: 17704326 Related Articles
MSCs are well known to migrate to injured tissue, so it’s not really specific homing to radiation-injured tissue, but this very preliminary work does show well that radiation is one of the types on injury that elicits a homing response.
A review of a rather old hypothesis about the decline in hematopoiesis in the elderly.
Funes JM, Quintero M, Henderson S, Martinez D, Qureshi U, Westwood C, Clements MO, Bourboulia D, Pedley RB, Moncada S, Boshoff C., Transformation of human mesenchymal stem cells increases their dependency on oxidative phosphorylation for energy production. Proc Natl Acad Sci U S A. 2007 Apr 10;104(15):6223-8. Epub 2007 Mar 23. PMID: 17384149 Related Articles
An interesting study indicating that the glycolytic shift of a tumor, the Warburg hypothesis, may not be occurring in MSCs, but rather that MSCs continue to depend on oxidative phosphorylation. They go on to say that glycolytic enzymes do increase, however, as the tumor adapts to the hypoxic environment it creates.
Ohnishi S, Sumiyoshi H, Kitamura S, Nagaya N., Mesenchymal stem cells attenuate cardiac fibroblast proliferation and collagen synthesis through paracrine actions. FEBS Lett. 2007 Aug 21;581(21):3961-6. Epub 2007 Jul 23. PMID: 17662720 Related Articles
Zeisberg EM, Tarnavski O, Zeisberg M, Dorfman AL, McMullen JR, Gustafsson E, Chandraker A, Yuan X, Pu WT, Roberts AB, Neilson EG, Sayegh MH, Izumo S, Kalluri R., Endothelial-to-mesenchymal transition contributes to cardiac fibrosis. Nat Med. 2007 Aug;13(8):952-61. Epub 2007 Jul 29. PMID: 17660828 Related Articles
Two papers on MSCs and cardiac fibrosis. The first one identifies some paracrine actions of MSCs in inhibition of fibrosis, and suggests a mechanism, while the second one goes int further details about fibrotic mechanisms.