Review for 10.1186/1471-230X-9-53 (2009)

Reviewer's report
Title:TNF-alpha-induced up-regulation of pro-inflammatory cytokines is delayed
by phosphatidylcholine in intestinal epithelial cells
Version: 3Date:2 October 2008
Reviewer: Eva Rath
Reviewer's report:
- Major Compulsory Revisions
1. Some of the figures in the manuscript and your publication “Anti-inflammatory
Effects of Phosphatidylcholine” are almost identical. You might want to change
that or cite the data.
2. Please state more clearly what has already been shown (e.g. Down-regulation
of TNF-#-induced gene expression in Caco-2 cells by PC )and what is new (e.g.
TNF receptor binding).
3. The conclusion stated in the title has been shown already in your previous
publication. Please be more specific what is new in this manuscript.
4. Title: why do you state that PC delays up-regulation of pro-inflammatory
genes? Regarding the data shown, the gene expression seems to be diminished
as the peak expression levels after TNF treatment are not attained after the
combined treatment with TNF and PC.
5. No significances are indicated in the figures or stated in the manuscript.
Please clearly indicate where differences are statistically significant.
6. Since you use cells transiently transfected with a reporter plasmid for the
luciferase assay, please use the term “p65 promoter binding” rather than “nuclear
translocation”.
7. Using an NF-#B inhibitor to investigate if it has an effect similar to that of PC
on cells is useful to generate a working hypothesis. But if you want to conclude
“the inhibitory effect of PC seems to be regulated via NF-#B pathway” you should
use MAPK inhibitors instead to see if they can reverse the inhibitory effect of PC
on TNF induced gene expression.
8. Please reconsider the succession of your results/figures to point out more
clearly what are you aiming for.
- Minor Essential Revisions
1. There are several grammatical and spelling errors throughout the manuscript;
there are also some redundant words and unclear expressions (Abstract: “PC
inhibits membrane dependent actin assembly in vitro and in cells as well as
TNF-# induced…)
2. Please review the abstract carefully. Text and Headlines do not always fit
together (Methods: The hypothesis that… this is more aim than method).
3. Make sure that all abbreviations are introduced the first time you use it (LPC,
SM).
4. Methods: Caco-2 cells are adherent cells, please use x% confluency instead of
density (1x105 cells/ml).
5. Flow cytometry: please give the density of Vero cells additionally to the volume
or the total number of cells. Please give the time of pre-incubation also in the
methods.
6. Please use various times instead of various minutes.
7. Results: please avoid “minor amounts” or “clear inhibition”, give the exact
amounts and use significant (if so) or tendency. (also in the abstract)
8. Description of figure 2: the figure shows %luciferase activity of cells 4h post
stimulation with TNF for different times of pre-incubation. The description in the
text “Within the first 30min NF-#B activation decreased with increasing time of
pre-treatment.” is not according to the figure and misleading. If this is an
additional observation, please add “data not shown”.
9. Please adapt the x axis of figure 1 “arbitrary units” to “% of luciferase activity of
cells stimulated with TNF-#” (like figure 2).
10. Figure 3: please use the labeling of the x axis of figure 3A also for figure B. I
would also suggest to use minutes instead of seconds in these figures.
- Discretionary Revisions
1. I would suggest that you give a brief overview over the lipids used in the
“background” and state differences in the chemical structure as some of them
show activity whereas others do not (discussion?).
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
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