Review for 10.1186/s12876-017-0731-5 (2018)

Reviewer ’s report  
 
Title: Cobalt Chloride Compromises Transepithelial Barrier Properties of CaCo -2 BBe Human 
Gastrointestinal Epithelial Cell Layers  
 
Version: 1 Date: 23 Aug 2017  
 
Reviewer: Rita Rosenthal  
 
Reviewer's report:  
 
James Mullin and coworkers have submitted the revision of their original manuscript entitled 
"Cobalt Chloride Compromises Transepithelial Barrier Properties of CACO -2 Human 
Gastrointestinal Epithelial Cell Layers" to BMC Gastroenterology.  
 
First of all, the authors uploaded wrong figures in the revised version of the manuscript, some 
figures are mis sing and the figure legends do not correspond to the figure legends and the notes 
in the text.  
 
The authors have changed  in some points according to the reviewer's suggestion. Unfortunately, 
some major points are not considered, some figures are changed,  but sometimes, the quality of 
the figures is not increased, e.g. correct wording in the figures (HIF -1ß as in the text instead of 
HIF-1B).  
 
 
Fig. 1A: Expression of HIF -1. It is not detectable from these Western blots that CoCl2, 
especially in a concentra tion of 125 µM, induces an increase in HIF -1 expression, to confirm 
this, the authors should present the densitometric analysis in combination with the Western blots. 
The increase in HIF -1 expression induced by CoCl2 is the major statement of the manuscr ipt 
and should be demonstrated very clearly.  
 
Fig. 2: I would suggest to present the Western blots in combination with the densitometric 
analysis, this is one lane above the bar diagrams, this is more confortable for the reader than to 
open the supplementa l figures.  
 
Fig. 7A: Instead of numbers 1 -8, Control KD and HIF -1ß KD (Not HIF -1B), the same 
description as in Fig. 7B.  
 
 
The authors discuss the role of tight junction proteins in barrier function, they should mention, 
that Caco -2 BBE cells express a lot of other tight junction proteins than occludin, claudin -5 and 
claudin -7, which are not investigated in this revised study and that changes in these tight junction 
proteins could also contribute to the effect of CoCl2 on barrier function.  
 
 
 
Are the methods appropriate and well described?  
If not,  please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequatel y supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or wo uld you recommend an 
additional statistical review?  
If an additional statistical review is recommend ed, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess t he statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Are the methods appropriate and well described?  
If not, please specify what is required i n your comments to the authors.  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way ga in or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the  future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the co ntent of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
If you can answer no to all of the above, write 'I declare that I have no competing inter ests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand t hat my name will be included 
on my report to the authors and, if the m anuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along  with the authors' 
responses. I agree for my report to be made available und er an Open Access  Creative Commons 
CC-BY license (http://creativecommons.org/licenses/by/4.0/ ). I understand that a ny comments 
which I do not wish to be included in my named report can be included as confidential  comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of t he journal