Neuronal Injury and Regeneration-Linked Gene Expression Dynamics in the Hypothalamic-Pituitary-Adrenal Axis Following...

Area of Science:

• Neuroscience
• Endocrinology
• Molecular Biology

Background:

• Traumatic brain injury (TBI) causes widespread molecular and neuroendocrine changes.
• The hypothalamic-pituitary-adrenal (HPA) axis is crucial for stress and metabolic regulation.
• Understanding TBI's impact on HPA axis gene transcription is vital for neuroendocrine dysfunction research.

Purpose of the Study:

• To investigate time-dependent gene transcription dynamics within the HPA axis after experimental TBI.
• To analyze genes related to neuronal injury and regeneration in the hypothalamus, pituitary, and adrenal glands.
• To understand the molecular mechanisms of HPA axis dysregulation and recovery post-TBI.

Main Methods:

• Induction of moderate-to-severe TBI using a controlled cortical impact (CCI) model in rats.
• Quantitative real-time PCR analysis of 24 HPA axis and neuroregeneration genes in tissue samples.
• Comparison of gene expression profiles at acute (24 h) and chronic (30 days) post-TBI time points versus sham controls.

Main Results:

• TBI induced distinct, tissue-specific, and time-dependent transcriptional alterations across the HPA axis.
• Acute phase showed divergent stress-response gene regulation between central and peripheral tissues.
• Chronic phase exhibited transcriptional reorganization involving neurotrophic, metabolic, and neuroendocrine pathways, with key regulators like Hif1a, Rad18, Avp, Gata3, and OxtR showing significant changes.

Conclusions:

• TBI triggers coordinated but heterogeneous transcriptional responses within the HPA axis.
• These responses link central injury to systemic endocrine adaptation and dysfunction.
• The study identifies potential therapeutic targets for TBI-related neuroendocrine disorders.