See the published version of this preprint at Journal of Neuroinflammation.
This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
A new preprint design is coming!
We have improved readability, clarity, accessibility, and opportunities for engagement.
Research
John Zhang
Loma Linda University Medical Center
Corresponding Author
ORCiD: https://orcid.org/0000-0002-4319-4285
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Neuroinflammation plays an important role in pathogenesis of germinal matrix hemorrhage (GMH). Neurotrophin-4 (NT-4) is a member of the neurotrophin family, and it interacts with the tyrosine kinase B (TrkB) receptor. It has been studied that NT-4 has neuroprotective effects following cerebral ischemia. We aimed to investigate the neuroprotective function of NT-4 and it’s high affinity receptor TrkB as well as its downstream mediator phosphatidylinositol-3-kinases (PI3K)/protein kinase B (Akt)/Forkhead box protein O1 (FoxO1) following GMH in neonatal rats, with a specific focus on inflammation.
Methods: GMH was induced by intraparenchymal injection of bacterial collagenase (0.3U) in P7 rat pups. A total of 163 seven-day-old pups were used in this study. The recombinant human NT-4 was administered intranasally at 1 hour after the collagenase injection. The selective TrkB antagonist ANA-12, selective PI3K inhibitor LY294002 and FoxO1 activating CRISPR were administered intracerebroventricularly at 24 hours prior to NT-4 treatment to investigate the potential mechanism. Short-and-long-term neurobehavior assessments, immunofluorescence staining, Nissl’s staining and Western blot were performed.
Results：The expression of p-TrkB increased after GMH with a peak at day3. The TrkB receptor was expressed by neurons, microglia, and astrocytes. The administration of rh-NT-4 increased phosphorylation of TrkB, expression of PI3K, phosphorylation of Akt and decreased FoxO1, IL-1beta and IL-6 levels. Selective inhibition of TrkB/PI3K/Akt signaling in microglia increased the expression levels of FoxO1 and pro-inflammatory cytokines. The use of FoxO1 activation CRISPR increased the expression of IL-6, suggesting that FoxO1 might potentially induce pro-inflammatory factors. These results demonstrated that PI3K/Akt/FoxO1 may be the downstream pathway of TrkB phosphorylation. The rat pups treated with rh-NT-4 performed better than untreated animals both in short-and-long-term behavior test.
Conclusion：These data showed that rh-NT-4 can reduce the expression of pro-inflammatory cytokines, improve neurological function, attenuate neuroinflammation and post-hemorrhagic hydrocephalus after GMH by promoting TrkB/PI3K/Akt/FoxO1 pathway. These results indicated that rh-NT-4 could be a promising therapeutic target to ameliorate neuroinflammation and hydrocephalus after GMH or other similar brain injuries.
Keywords
Germinal matrix hemorrhage, neurotrophin-4, TrkB, neuroinflammation, hydrocephalus
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
This is a list of supplementary files associated with this preprint. Click to download.
Loading...
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Published
View the published article at Journal of Neuroinflammation.
No community comments so far
Review #2 received
Received 28 Apr, 2020
Editorial decision: Accept
On 28 Apr, 2020
Review #1 received
Received 24 Apr, 2020
Reviewer #2 agreed
On 23 Apr, 2020
Reviewer #1 agreed
On 17 Apr, 2020
Reviewers invited
Invitations sent on 15 Apr, 2020
Editor assigned
On 14 Apr, 2020
Submission checks complete
On 13 Apr, 2020
Editor invited
On 13 Apr, 2020
No comments provided
Editorial decision: Major Revision
On 09 Mar, 2020
Review #2 received
Received 08 Mar, 2020
Reviewer #2 agreed
On 06 Mar, 2020
Review #1 received
Received 05 Mar, 2020
Reviewers invited
Invitations sent on 26 Feb, 2020
Reviewer #1 agreed
On 26 Feb, 2020
Editor assigned
On 25 Feb, 2020
Submission checks complete
On 24 Feb, 2020
Editor invited
On 24 Feb, 2020
Version 1
Posted 13 Dec, 2019
No comments provided
Editorial decision: Major Revision
On 02 Jan, 2020
Review #2 received
Received 30 Dec, 2019
Reviewer #2 agreed
On 28 Dec, 2019
Review #1 received
Received 22 Dec, 2019
Reviewer #1 agreed
On 09 Dec, 2019
Reviewers invited
Invitations sent on 07 Dec, 2019
Editor assigned
On 06 Dec, 2019
First submitted
On 05 Dec, 2019
Submission checks complete
On 05 Dec, 2019
Editor invited
On 05 Dec, 2019
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Neurobiology of Disease
Learn more about our company.
A new preprint design is coming!
We have improved readability, clarity, accessibility, and opportunities for engagement.
See the published version of this preprint at Journal of Neuroinflammation.
This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research
John Zhang
Loma Linda University Medical Center
Corresponding Author
ORCiD: https://orcid.org/0000-0002-4319-4285
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Published
View the published article at Journal of Neuroinflammation.
No community comments so far
Review #2 received
Received 28 Apr, 2020
Editorial decision: Accept
On 28 Apr, 2020
Review #1 received
Received 24 Apr, 2020
Reviewer #2 agreed
On 23 Apr, 2020
Reviewer #1 agreed
On 17 Apr, 2020
Reviewers invited
Invitations sent on 15 Apr, 2020
Editor assigned
On 14 Apr, 2020
Submission checks complete
On 13 Apr, 2020
Editor invited
On 13 Apr, 2020
No comments provided
Editorial decision: Major Revision
On 09 Mar, 2020
Review #2 received
Received 08 Mar, 2020
Reviewer #2 agreed
On 06 Mar, 2020
Review #1 received
Received 05 Mar, 2020
Reviewers invited
Invitations sent on 26 Feb, 2020
Reviewer #1 agreed
On 26 Feb, 2020
Editor assigned
On 25 Feb, 2020
Submission checks complete
On 24 Feb, 2020
Editor invited
On 24 Feb, 2020
Version 1
Posted 13 Dec, 2019
No comments provided
Editorial decision: Major Revision
On 02 Jan, 2020
Review #2 received
Received 30 Dec, 2019
Reviewer #2 agreed
On 28 Dec, 2019
Review #1 received
Received 22 Dec, 2019
Reviewer #1 agreed
On 09 Dec, 2019
Reviewers invited
Invitations sent on 07 Dec, 2019
Editor assigned
On 06 Dec, 2019
First submitted
On 05 Dec, 2019
Submission checks complete
On 05 Dec, 2019
Editor invited
On 05 Dec, 2019
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Neurobiology of Disease
License:
This work is licensed under a CC BY 4.0 License. Read Full License
View the published article at Journal of Neuroinflammation.
Background: Neuroinflammation plays an important role in pathogenesis of germinal matrix hemorrhage (GMH). Neurotrophin-4 (NT-4) is a member of the neurotrophin family, and it interacts with the tyrosine kinase B (TrkB) receptor. It has been studied that NT-4 has neuroprotective effects following cerebral ischemia. We aimed to investigate the neuroprotective function of NT-4 and it’s high affinity receptor TrkB as well as its downstream mediator phosphatidylinositol-3-kinases (PI3K)/protein kinase B (Akt)/Forkhead box protein O1 (FoxO1) following GMH in neonatal rats, with a specific focus on inflammation.
Methods: GMH was induced by intraparenchymal injection of bacterial collagenase (0.3U) in P7 rat pups. A total of 163 seven-day-old pups were used in this study. The recombinant human NT-4 was administered intranasally at 1 hour after the collagenase injection. The selective TrkB antagonist ANA-12, selective PI3K inhibitor LY294002 and FoxO1 activating CRISPR were administered intracerebroventricularly at 24 hours prior to NT-4 treatment to investigate the potential mechanism. Short-and-long-term neurobehavior assessments, immunofluorescence staining, Nissl’s staining and Western blot were performed.
Results：The expression of p-TrkB increased after GMH with a peak at day3. The TrkB receptor was expressed by neurons, microglia, and astrocytes. The administration of rh-NT-4 increased phosphorylation of TrkB, expression of PI3K, phosphorylation of Akt and decreased FoxO1, IL-1beta and IL-6 levels. Selective inhibition of TrkB/PI3K/Akt signaling in microglia increased the expression levels of FoxO1 and pro-inflammatory cytokines. The use of FoxO1 activation CRISPR increased the expression of IL-6, suggesting that FoxO1 might potentially induce pro-inflammatory factors. These results demonstrated that PI3K/Akt/FoxO1 may be the downstream pathway of TrkB phosphorylation. The rat pups treated with rh-NT-4 performed better than untreated animals both in short-and-long-term behavior test.
Conclusion：These data showed that rh-NT-4 can reduce the expression of pro-inflammatory cytokines, improve neurological function, attenuate neuroinflammation and post-hemorrhagic hydrocephalus after GMH by promoting TrkB/PI3K/Akt/FoxO1 pathway. These results indicated that rh-NT-4 could be a promising therapeutic target to ameliorate neuroinflammation and hydrocephalus after GMH or other similar brain injuries.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
This is a list of supplementary files associated with this preprint. Click to download.
Loading...