Limits...
Neurogenic and neurotrophic effects of BDNF peptides in mouse hippocampal primary neuronal cell cultures.

Cardenas-Aguayo Mdel C, Kazim SF, Grundke-Iqbal I, Iqbal K - PLoS ONE (2013)

Bottom Line: Peptide B-3, when combined with BDNF, potentiated the survival effect of this neurotrophin on H(2)O(2)-treated E18 hippocampal cells.Peptides B-3 and B-5 were found to work as partial agonists and as partial antagonists competing with BDNF to activate the TrkB receptor in a dose-dependent manner.Taken together, these results suggest that the described BDNF tetra peptides are neurotrophic, can modulate BDNF signaling in a partial agonist/antagonist way, and offer a novel therapeutic approach to neural pathologies where BDNF levels are dysregulated.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America.

ABSTRACT
The level of brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is down regulated in Alzheimer's disease (AD), Parkinson's disease (PD), depression, stress, and anxiety; conversely the level of this neurotrophin is increased in autism spectrum disorders. Thus, modulating the level of BDNF can be a potential therapeutic approach for nervous system pathologies. In the present study, we designed five different tetra peptides (peptides B-1 to B-5) corresponding to different active regions of BDNF. These tetra peptides were found to be non-toxic, and they induced the expression of neuronal markers in mouse embryonic day 18 (E18) primary hippocampal neuronal cultures. Additionally, peptide B-5 induced the expression of BDNF and its receptor, TrkB, suggesting a positive feedback mechanism. The BDNF peptides induced only a moderate activation (phosphorylation at Tyr 706) of the TrkB receptor, which could be blocked by the Trk's inhibitor, K252a. Peptide B-3, when combined with BDNF, potentiated the survival effect of this neurotrophin on H(2)O(2)-treated E18 hippocampal cells. Peptides B-3 and B-5 were found to work as partial agonists and as partial antagonists competing with BDNF to activate the TrkB receptor in a dose-dependent manner. Taken together, these results suggest that the described BDNF tetra peptides are neurotrophic, can modulate BDNF signaling in a partial agonist/antagonist way, and offer a novel therapeutic approach to neural pathologies where BDNF levels are dysregulated.

Show MeSH

Related in: MedlinePlus

(A,B) The increase in expression of BDNF in primary hippocampal cells caused by BDNF peptides or BDNF after two days of treatment can be blocked by pre-exposure (1 h before adding the peptides) to protein synthesis inhibitor, cycloheximide (CHX) or to TrkB inhibitor, K252a.(A) Western blots of BDNF, and total TrkB, of hippocampal cells treated with 0.1 µM peptide B-5 or 20 ng/ml BDNF or vehicle treated, and when indicated, also pretreated with CHX or K252a (B) Densitometric quantitation of the Western-blots for BDNF and TrkB normalized to the corresponding control cells (control, C) in each condition. Data are shown as mean ± standard deviation, n = 3. *p<0.05, **p<0.01. One-way ANOVA/post-hoc test/Student’s t test.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3539976&req=5

pone-0053596-g008: (A,B) The increase in expression of BDNF in primary hippocampal cells caused by BDNF peptides or BDNF after two days of treatment can be blocked by pre-exposure (1 h before adding the peptides) to protein synthesis inhibitor, cycloheximide (CHX) or to TrkB inhibitor, K252a.(A) Western blots of BDNF, and total TrkB, of hippocampal cells treated with 0.1 µM peptide B-5 or 20 ng/ml BDNF or vehicle treated, and when indicated, also pretreated with CHX or K252a (B) Densitometric quantitation of the Western-blots for BDNF and TrkB normalized to the corresponding control cells (control, C) in each condition. Data are shown as mean ± standard deviation, n = 3. *p<0.05, **p<0.01. One-way ANOVA/post-hoc test/Student’s t test.

Mentions: To evaluate whether the effect of B-5 and B-3 in induction of the expression of BDNF and TrkB was via the activation of the TrkB receptor and required signal transduction via TrkB and new protein synthesis, we pre-treated mouse embryonic E18 cultured hippocampal cells with the protein synthesis inhibitor, cycloheximide (CHX) or the Trk inhibitor, K252a for 1 h, and then added Peptide B-5 at a concentration of 0.1 µM (the dose that gave the maximum induction of BDNF expression, Fig. 5A,B) or BDNF 20 ng/ml as a positive control (Fig. 8A, B). We studied a time course of these treatments with Peptide B-5 or BDNF for 15 min, 60 min and 2 days. At 2 days there was a significant (ANOVA, p<0.05) inhibition of the increase in the expression of BDNF and of TrkB by the Peptide B-5 in the presence of CHX; and there was no more significant induction of the expression of either BDNF or TrkB by B-5 in cells treated with the Trk inhibitor (K252a) (Fig. 8A, B). The trends in the reduction of BDNF expression were similar to 2days at 15 min and 60 min time points, however, TrkB inhibition was evident only at 60 minute time point, and reached a marked significance at 2 days time point. Since the effect of BDNF peptides was not completely blocked by K252a, there is a possibility that these peptides activate alternate pathways that lead to expression of BDNF and TrkB.


Neurogenic and neurotrophic effects of BDNF peptides in mouse hippocampal primary neuronal cell cultures.

Cardenas-Aguayo Mdel C, Kazim SF, Grundke-Iqbal I, Iqbal K - PLoS ONE (2013)

(A,B) The increase in expression of BDNF in primary hippocampal cells caused by BDNF peptides or BDNF after two days of treatment can be blocked by pre-exposure (1 h before adding the peptides) to protein synthesis inhibitor, cycloheximide (CHX) or to TrkB inhibitor, K252a.(A) Western blots of BDNF, and total TrkB, of hippocampal cells treated with 0.1 µM peptide B-5 or 20 ng/ml BDNF or vehicle treated, and when indicated, also pretreated with CHX or K252a (B) Densitometric quantitation of the Western-blots for BDNF and TrkB normalized to the corresponding control cells (control, C) in each condition. Data are shown as mean ± standard deviation, n = 3. *p<0.05, **p<0.01. One-way ANOVA/post-hoc test/Student’s t test.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539976&req=5

pone-0053596-g008: (A,B) The increase in expression of BDNF in primary hippocampal cells caused by BDNF peptides or BDNF after two days of treatment can be blocked by pre-exposure (1 h before adding the peptides) to protein synthesis inhibitor, cycloheximide (CHX) or to TrkB inhibitor, K252a.(A) Western blots of BDNF, and total TrkB, of hippocampal cells treated with 0.1 µM peptide B-5 or 20 ng/ml BDNF or vehicle treated, and when indicated, also pretreated with CHX or K252a (B) Densitometric quantitation of the Western-blots for BDNF and TrkB normalized to the corresponding control cells (control, C) in each condition. Data are shown as mean ± standard deviation, n = 3. *p<0.05, **p<0.01. One-way ANOVA/post-hoc test/Student’s t test.
Mentions: To evaluate whether the effect of B-5 and B-3 in induction of the expression of BDNF and TrkB was via the activation of the TrkB receptor and required signal transduction via TrkB and new protein synthesis, we pre-treated mouse embryonic E18 cultured hippocampal cells with the protein synthesis inhibitor, cycloheximide (CHX) or the Trk inhibitor, K252a for 1 h, and then added Peptide B-5 at a concentration of 0.1 µM (the dose that gave the maximum induction of BDNF expression, Fig. 5A,B) or BDNF 20 ng/ml as a positive control (Fig. 8A, B). We studied a time course of these treatments with Peptide B-5 or BDNF for 15 min, 60 min and 2 days. At 2 days there was a significant (ANOVA, p<0.05) inhibition of the increase in the expression of BDNF and of TrkB by the Peptide B-5 in the presence of CHX; and there was no more significant induction of the expression of either BDNF or TrkB by B-5 in cells treated with the Trk inhibitor (K252a) (Fig. 8A, B). The trends in the reduction of BDNF expression were similar to 2days at 15 min and 60 min time points, however, TrkB inhibition was evident only at 60 minute time point, and reached a marked significance at 2 days time point. Since the effect of BDNF peptides was not completely blocked by K252a, there is a possibility that these peptides activate alternate pathways that lead to expression of BDNF and TrkB.

Bottom Line: Peptide B-3, when combined with BDNF, potentiated the survival effect of this neurotrophin on H(2)O(2)-treated E18 hippocampal cells.Peptides B-3 and B-5 were found to work as partial agonists and as partial antagonists competing with BDNF to activate the TrkB receptor in a dose-dependent manner.Taken together, these results suggest that the described BDNF tetra peptides are neurotrophic, can modulate BDNF signaling in a partial agonist/antagonist way, and offer a novel therapeutic approach to neural pathologies where BDNF levels are dysregulated.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America.

ABSTRACT
The level of brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is down regulated in Alzheimer's disease (AD), Parkinson's disease (PD), depression, stress, and anxiety; conversely the level of this neurotrophin is increased in autism spectrum disorders. Thus, modulating the level of BDNF can be a potential therapeutic approach for nervous system pathologies. In the present study, we designed five different tetra peptides (peptides B-1 to B-5) corresponding to different active regions of BDNF. These tetra peptides were found to be non-toxic, and they induced the expression of neuronal markers in mouse embryonic day 18 (E18) primary hippocampal neuronal cultures. Additionally, peptide B-5 induced the expression of BDNF and its receptor, TrkB, suggesting a positive feedback mechanism. The BDNF peptides induced only a moderate activation (phosphorylation at Tyr 706) of the TrkB receptor, which could be blocked by the Trk's inhibitor, K252a. Peptide B-3, when combined with BDNF, potentiated the survival effect of this neurotrophin on H(2)O(2)-treated E18 hippocampal cells. Peptides B-3 and B-5 were found to work as partial agonists and as partial antagonists competing with BDNF to activate the TrkB receptor in a dose-dependent manner. Taken together, these results suggest that the described BDNF tetra peptides are neurotrophic, can modulate BDNF signaling in a partial agonist/antagonist way, and offer a novel therapeutic approach to neural pathologies where BDNF levels are dysregulated.

Show MeSH
Related in: MedlinePlus