Profiling of hypoxic and extracellular matrix remodeling markers in biofluids and cerebral tissue after traumatic brain injury: expression and signaling crosstalk of HIF-1α, MMP-9/14 and EPHA2.

Traumatic brain injury (TBI) remains a formidable clinical, neuropathological, and forensic challenge, constituting a leading cause of death as well a neuroscientific research target worldwide. A deeper understanding of the molecular signatures underlying vascular and extracellular matrix remodeling in TBI seems to be critical both for the development of diagnostic biomarkers in post-mortem neuropathology and for identifying potential therapeutic targets in the acute injury setting. Despite the individual exploration of HIF-1α, MMP-9/14, and EPHA2 in neurological injury, few studies have offered a comprehensive, integrative examination of these biomarkers within the human TBI brain, especially in post-mortem forensic contexts. The study concerned a total of 40 individuals, cases with head injuries (n = 20) suspected to be the cause of death, and atraumatic control cases of sudden death (n = 20) due to cardiopulmonary reasons. Brain tissue was obtained during forensic autopsies and subjected to immunohistochemical staining. Cerebrospinal fluid (CSF) and serum were collected approximately 24 h post-mortem and analyzed through ELISA testing. We observed the elevated concentration level of HIF-1α, MMP-9 and MMP-14 in CSF. In the frontal cortex, anti-EPHA2 immunohistostaining revealed a generalized homogenization of the reaction was observed both within the neuronal bodies (including nuclear area) and their axons among the study group. Rather than relying solely on macroscopic signs of trauma, the present study proposes a layered biomarker architecture wherein HIF-1α reflects hypoxic load, MMP-9/14 denotes matrix remodeling and barrier disruption, and EPHA2 signals cellular stress and neurovascular dysregulation. Such a composite signature provides a biological foundation that may ultimately be translated into post-mortem diagnostic algorithms or pilot machine-learning-based forensic stratification tools following validation in larger, multicenter cohorts.