Growth Hormone and IGF-1 axis implicated in brain regeneration across dementia, TBI, and stroke

The Growth Hormone (GH)-Insulin-like Growth Factor 1 (IGF-1) axis is classically known for regulating bone growth and metabolism, but GH is also expressed in extrapituitary tissues, including the brain. In the brain, IGF-1 is synthesized by neurons and glial cells, exerting regulatory effects on cerebral neuroendocrine regions. This local action of GH and IGF-1, mediated via the GH receptor (GHR) and IGF-1 receptor (IGF-1R) and activating pathways like JAK2, suggests a crucial role beyond systemic growth, potentially influencing proliferation and anti-apoptosis within the central nervous system. Understanding this axis could reveal new therapeutic avenues for neurodegenerative and neurotraumatic conditions.

This systematic review synthesized evidence from clinical studies investigating the role of Growth Hormone (GH) and its associated axis in brain regeneration. The authors focused on three major neurological conditions: dementia, traumatic brain injury (TBI), and stroke. The review aimed to consolidate existing clinical data on GH's potential neuroregenerative effects, examining its interactions with the GH receptor (GHR) and IGF-1 receptor (IGF-1R) and downstream signaling pathways like JAK2. The methodology involved a comprehensive search of clinical literature to identify studies relevant to GH and brain repair in these patient populations.