GHRH Agonist MR-409 Protects Brain Cells and Promotes Recovery After Stroke in Mice
The synthetic GHRH agonist MR-409 reduced stroke mortality, brain damage, and hippocampal atrophy while promoting neurogenesis and functional recovery through AKT/CREB and BDNF/TrkB pathway activation in mice.
Quick Facts
What This Study Found
MR-409 (5-10 μg/mouse/day SC) reduced mortality, ischemic damage, and hippocampal atrophy in tMCAO stroke mice. Enhanced endogenous neurogenesis and neuroplasticity. Protected neural stem cells from oxygen-glucose deprivation. Mechanism: AKT/CREB and BDNF/TrkB activation.
Key Numbers
5 or 10 μg/mouse/day s.c.; reduced mortality and ischemic insult; pathways: AKT/CREB, BDNF/TrkB; tMCAO model
How They Did This
Animal study. Transient middle cerebral artery occlusion (tMCAO) stroke model in mice. MR-409 subcutaneous injection (5 or 10 μg/mouse/day). Mortality, infarct size, hippocampal volume, neurogenesis, and neurological function assessed. Neural stem cell in vitro studies. AKT/CREB and BDNF/TrkB pathway analysis.
Why This Research Matters
Stroke is the second leading cause of death and leading cause of disability worldwide. No drug currently promotes brain repair after stroke. A GHRH agonist that both protects neurons and generates new ones could be transformative.
The Bigger Picture
GHRH agonists are being explored for multiple protective roles — from cancer cachexia to cardiac injury to now stroke. Their cell-protective and regenerative properties suggest a fundamental role in tissue survival signaling beyond just growth hormone release.
What This Study Doesn't Tell Us
Mouse stroke model — human stroke is more complex. Long-term treatment started after stroke onset. Translation of neurogenesis findings to humans uncertain. Specific contribution of growth hormone release vs direct neuroprotection not fully separated.
Questions This Raises
- ?Would MR-409 or similar GHRH agonists improve stroke recovery in human clinical trials?
- ?Is the neuroprotection mediated directly by GHRH receptor activation or indirectly through growth hormone?
- ?What is the optimal treatment window after stroke for GHRH agonist administration?
Trust & Context
- Key Stat:
- Protect + regenerate MR-409 both protected existing neurons from stroke damage AND generated new neurons — addressing the two biggest needs in stroke recovery
- Evidence Grade:
- Moderate evidence: animal stroke model with multiple endpoints (mortality, histology, function, neurogenesis, mechanism) showing consistent benefit.
- Study Age:
- Published 2021. GHRH agonists for neuroprotection are in early clinical development.
- Original Title:
- Agonistic analog of growth hormone-releasing hormone promotes neurofunctional recovery and neural regeneration in ischemic stroke.
- Published In:
- Proceedings of the National Academy of Sciences of the United States of America, 118(47) (2021)
- Authors:
- Liu, Yueyang(2), Yang, Jingyu(2), Che, Xiaohang(2), Huang, Jianhua, Zhang, Xianyang, Fu, Xiaoxiao, Cai, Jialing, Yao, Yang, Zhang, Haotian, Cai, Ruiping, Su, Xiaomin, Xu, Qian, Ren, Fu, Cai, Renzhi, Schally, Andrew V, Zhou, Ming-Sheng
- Database ID:
- RPEP-05565
Evidence Hierarchy
Frequently Asked Questions
Could this help stroke patients?
In mice, MR-409 reduced death, brain damage, and disability after stroke while generating new brain cells. This is very promising, but mouse brains are much smaller and simpler than human brains. Clinical trials would be needed to confirm benefits in people.
What is GHRH and how does it protect the brain?
GHRH (growth hormone-releasing hormone) is a brain peptide that stimulates growth hormone release. MR-409, a synthetic GHRH agonist, appears to directly activate cell survival pathways (AKT/CREB, BDNF) in brain tissue, protecting neurons from stroke damage and stimulating new neuron growth.
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Cite This Study
https://rethinkpeptides.com/research/RPEP-05565APA
Liu, Yueyang; Yang, Jingyu; Che, Xiaohang; Huang, Jianhua; Zhang, Xianyang; Fu, Xiaoxiao; Cai, Jialing; Yao, Yang; Zhang, Haotian; Cai, Ruiping; Su, Xiaomin; Xu, Qian; Ren, Fu; Cai, Renzhi; Schally, Andrew V; Zhou, Ming-Sheng. (2021). Agonistic analog of growth hormone-releasing hormone promotes neurofunctional recovery and neural regeneration in ischemic stroke.. Proceedings of the National Academy of Sciences of the United States of America, 118(47). https://doi.org/10.1073/pnas.2109600118
MLA
Liu, Yueyang, et al. "Agonistic analog of growth hormone-releasing hormone promotes neurofunctional recovery and neural regeneration in ischemic stroke.." Proceedings of the National Academy of Sciences of the United States of America, 2021. https://doi.org/10.1073/pnas.2109600118
RethinkPeptides
RethinkPeptides Research Database. "Agonistic analog of growth hormone-releasing hormone promote..." RPEP-05565. Retrieved from https://rethinkpeptides.com/research/liu-2021-agonistic-analog-of-growth
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.