Review for 10.1186/1471-230X-10-65 (2010)

Reviewer's report
Title:Altered Expression of a Putative Progenitor Cell Marker DCAMKL1 in the
Gastric Mucosa in Regeneration, Metaplasia and Dysplasia
Version: 1Date:3 March 2010
Reviewer: Jonathan Kaunitz
Reviewer's report:
The authors have submitted a manuscript addressing the localization of the
putative stem cell marker DCAMKL1 in normal rat stomach and in a variety of
gastric injury models.The manuscript consists entirely of the depiction of
histological sections of rat stomach stained for DCAMLK1 and other proliferation
markers. The experiments appear to be well performed and the images appear to
be of high quality.
Comments:
• Major Issues
1. The abstract seems to be too long
2. Two publications have appeared recently that need to be cited and discussed.
Zhang (J Gastroenterol Hepatol Jan 14 2010) describes similar studies in which
he localized DCAMKL-1 in normal mouse stomach and recovering from injury
due to acidified ethanol. Barker (Cell Stem Cell 2010 6:25) describes localization
of the stem cell marker Lgr5 in the base of mouse pyloric glands, using lineage
tracing to demonstrate their clonal origin. This discrepancy regarding the
localization of putative stem cells seems to recapitulate a similar controversy in
the small intestine and bears discussion with regard to the origin of the
proliferative compartment in the stomach. Although the authors carefully avoid
the term “stem cell”, these data suggest that even the term “progenitor cell” is not
firmly established based on the associative studies shown.
3. Although the manuscript is necessarily descriptive, it could be organized much
more coherently. For example, the importance of the questions asked can be
presented initially followed by a rationale for the experimental strategies used
including a justification and description of the models. A more detailed and
focused background is this necessary in order to better orient the reader. For
example, the authors mention H. pylori and neoplasia in the Introduction even
though none of their data address these areas.
4. A schematic drawing (cartoon) of the gastric gland showing the normal
architecture and location of the lineages combined with a metaplastic or
pathological gland or healing ulcer margin can also increase the clarity of the
presentation.
5. Please explain the significance of SPEM in more detail
6. Please explain that the chronic ulcer models used was the acetic acid ulcer in
the "Results" section. Three figures are used to depict ulcer healing; the time
points chosen after acetic acid injection and their significance should be
explained.
7. The description of TFF2 expression in the healing ulcer margin should be
discussed in the context of the studies of Thim and others.
8. Please discuss the significance of PAS and Alcian blue staining
9. Although 7f shows the proximity of PCNA positive cells to DCAMKL1 cells, this
does not seem to be consistent, at least in 7c. Please comment. I would avoid
using "above and below" since this is misleading; "in the proximity of" or similar is
preferred.
10. The last sentence of the first paragraph of p. 20 is entirely speculative and
should thus be deleted.
Minor Essential Revisions
1. Please use the term "rat" in the title
2. P. 6 "ontology-enriched" ?
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'