Questioning the concept of stem cell plasticity: Tissue-committed early muscle, liver and neural cells reside in the bone marrow and can be isolated by chemotactic gradients to SDF-1, HGF or LIF and mobilized into peripheral blood during tissue/organ injury
Bibliographic record
Abstract
2790 We recently demonstrated that bone marrow (BM) contains a population of CXCR4- positive cells that express mRNA for various markers for skeletal muscle (Myf-5, Myo-D), heart muscle (Nkx2.5/Csx, GAR-4), neural (GFAP, nestin) and liver (CK19, fetoprotein) early tissue-committed stem/progenitor cells which could be isolated from BM by an SDF-1 chemotactic gradient (Leukemia, 2003, online and in press). As a follow-up to this study we report here that these cells i) respond to HGF/SF and LIF gradients as well as SDF-1, ii) are enriched in populations of BM-derived CD45-negative non-adherent cells from “lymph-gating”, iii) are highest in number in BM from young (1–2 month-old) mice and rapidly decrease in 1-year-old animals, and iv) are released from BM during tissue injury (e.g., after partial body irradiation). Further, since SDF-1, HGF/SF and LIF are simultaneously upregulated in damaged tissues, circulating early tissue-committed CXCR4+ c-Met+ LIF-R+ cells could be chemoattracted to the damaged organs and play a role in their regeneration. Hence, these data further support our view of the BM being not only a home for hematopoietic stem cells but also a “hideout” for already differentiated non-hematopoietic CD45-negative and CXCR4+ c-Met+ LIF-R+ tissue-committed stem/progenitor cells. These cells, following SDF-1, HGF/SF and LIF gradients, could be mobilized into peripheral blood and subsequently take part in organ/tissue regeneration. Moreover, since the concentration of these cells is highest in young animals, this may help to explain why the regeneration process becomes less efficient with advancing age. Finally, these findings further support our perspective of the BM as a “hideout” of tissue-committed progenitor cells (Stem Cells 2003;12:363) and we strongly suggest that the implications of this are considered before experimental evidence is interpreted as indicating transdifferentiation/plasticity of non-embryonic stem cells. #
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.007 |
| Scholarly communication | 0.003 | 0.008 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.004 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".