Reviewer's report
Title:GDNF protects apoptosis in enteric glia: Evidence for an autocrine loop
Version: 2Date:14 June 2011
Reviewer: Bindu Chandrasekharan
Reviewer's report:
The authors Steinkamp et al in their article ‘ GDNF protects apoptosis in enteric
glia: Evidence for an autocrine loop’ aims to unravel the role of a neurotrophin-
glial derived neurotrophic factor (GDNF) in the regulation of enteric glial
apoptosis. The authors observed GDNF and apoptosis marker (caspase3/7) in
the biopsy specimens of Crohn’s disease patients by immunofluorescence. In
vitro studies on enteric glial cultures (EGC) revealed that the combination of
IFN-# and TNF-# induced apoptosis, but addition of GDNF to the culture does
not affect the amount of apoptosis. However, neutralization of GDNF in the EGC
cultures dramatically increased apoptosis in these cells. The authors claim that
as enteric glia produce high amounts of GDNF during inflammation, their results
suggest an autocrine apoptosis protection loop in these cells in CD.
The manuscript needs following revisions before publication.
Major compulsory revisons
1. The authors have shown GFAP/ Caspase-3/7 merge staining and GFAP/
GDNF merge staining in biopsies. It would be interesting to check if GDNF
positive tissue is positive for caspase-3/7 and this result would add to the
conclusions.
2. Have authors looked at expression of GDNF receptors (GFR and Ret) in the
Crohn’s patient biopsies-is there an upregulation?
3. The authors demonstrated that addition of anti-GDNF antibody increases the
extent of apoptosis induced by a combination of TNF and IFN. Is this true for
other cytokines like IL-1B or IL-6 on glial apoptosis. The authors could try a
combination of pro-inflammatory cytokines (TNF+ IL-6 + IL-1B) and validate their
result with anti-GDNF antibody.
4. The enteric glial cell apoptosis has been demonstrated by caspase3/7
staining, have authors looked at glial cell proliferation in the biopsies staining and
in vitro cultures by Ki 67 or BrDU staining. This would help assess if increased
apoptosis is related to decrease in cellular proliferation or an effect of GDNF in
itself.
Minor revision
5. The conclusion part of the manuscript seems to reiterate the results, authors
could cite more relevant references and compare and discuss their results.
Level of interest: An article of importance in its field
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
Reviewer's report
Title:GDNF protects apoptosis in enteric glia: Evidence for an autocrine loop
Version: 2Date:14 June 2011
Reviewer: Bindu Chandrasekharan
Reviewer's report:
The authors Steinkamp et al in their article ‘ GDNF protects apoptosis in enteric
glia: Evidence for an autocrine loop’ aims to unravel the role of a neurotrophin-
glial derived neurotrophic factor (GDNF) in the regulation of enteric glial
apoptosis. The authors observed GDNF and apoptosis marker (caspase3/7) in
the biopsy specimens of Crohn’s disease patients by immunofluorescence. In
vitro studies on enteric glial cultures (EGC) revealed that the combination of
IFN-# and TNF-# induced apoptosis, but addition of GDNF to the culture does
not affect the amount of apoptosis. However, neutralization of GDNF in the EGC
cultures dramatically increased apoptosis in these cells. The authors claim that
as enteric glia produce high amounts of GDNF during inflammation, their results
suggest an autocrine apoptosis protection loop in these cells in CD.
The manuscript needs following revisions before publication.
Major compulsory revisons
1. The authors have shown GFAP/ Caspase-3/7 merge staining and GFAP/
GDNF merge staining in biopsies. It would be interesting to check if GDNF
positive tissue is positive for caspase-3/7 and this result would add to the
conclusions.
2. Have authors looked at expression of GDNF receptors (GFR and Ret) in the
Crohn’s patient biopsies-is there an upregulation?
3. The authors demonstrated that addition of anti-GDNF antibody increases the
extent of apoptosis induced by a combination of TNF and IFN. Is this true for
other cytokines like IL-1B or IL-6 on glial apoptosis. The authors could try a
combination of pro-inflammatory cytokines (TNF+ IL-6 + IL-1B) and validate their
result with anti-GDNF antibody.
4. The enteric glial cell apoptosis has been demonstrated by caspase3/7
staining, have authors looked at glial cell proliferation in the biopsies staining and
in vitro cultures by Ki 67 or BrDU staining. This would help assess if increased
apoptosis is related to decrease in cellular proliferation or an effect of GDNF in
itself.
Minor revision
5. The conclusion part of the manuscript seems to reiterate the results, authors
could cite more relevant references and compare and discuss their results.
Level of interest: An article of importance in its field
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
Please review this paper.
user
Reviewer's report
Title:GDNF protects apoptosis in enteric glia: Evidence for an autocrine loop
Version: 2Date:14 June 2011
Reviewer: Bindu Chandrasekharan
Reviewer's report:
The authors Steinkamp et al in their article ‘ GDNF protects apoptosis in enteric
glia: Evidence for an autocrine loop’ aims to unravel the role of a neurotrophin-
glial derived neurotrophic factor (GDNF) in the regulation of enteric glial
apoptosis. The authors observed GDNF and apoptosis marker (caspase3/7) in
the biopsy specimens of Crohn’s disease patients by immunofluorescence. In
vitro studies on enteric glial cultures (EGC) revealed that the combination of
IFN-# and TNF-# induced apoptosis, but addition of GDNF to the culture does
not affect the amount of apoptosis. However, neutralization of GDNF in the EGC
cultures dramatically increased apoptosis in these cells. The authors claim that
as enteric glia produce high amounts of GDNF during inflammation, their results
suggest an autocrine apoptosis protection loop in these cells in CD.
The manuscript needs following revisions before publication.
Major compulsory revisons
1. The authors have shown GFAP/ Caspase-3/7 merge staining and GFAP/
GDNF merge staining in biopsies. It would be interesting to check if GDNF
positive tissue is positive for caspase-3/7 and this result would add to the
conclusions.
2. Have authors looked at expression of GDNF receptors (GFR and Ret) in the
Crohn’s patient biopsies-is there an upregulation?
3. The authors demonstrated that addition of anti-GDNF antibody increases the
extent of apoptosis induced by a combination of TNF and IFN. Is this true for
other cytokines like IL-1B or IL-6 on glial apoptosis. The authors could try a
combination of pro-inflammatory cytokines (TNF+ IL-6 + IL-1B) and validate their
result with anti-GDNF antibody.
4. The enteric glial cell apoptosis has been demonstrated by caspase3/7
staining, have authors looked at glial cell proliferation in the biopsies staining and
in vitro cultures by Ki 67 or BrDU staining. This would help assess if increased
apoptosis is related to decrease in cellular proliferation or an effect of GDNF in
itself.
Minor revision
5. The conclusion part of the manuscript seems to reiterate the results, authors
could cite more relevant references and compare and discuss their results.
Level of interest: An article of importance in its field
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
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