Plasmid pLXSN-Mediated Adrenomedullin Gene Therapy for Cerebral Vasospasm Following Subarachnoid Hemorrhage in Rats

miR-24 targets HMOX1 to regulate inflammation and neurofunction in rats with cerebral vasospasm after subarachnoid hemorrhage

OBJECTIVE

To investigate the effects of miR-24 and HMOX1 on the inflammatory response and neurological function in rats with cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH).

METHODS

Fifteen Sprague-Dawley rats were randomly assigned to the sham group (sham operation, treated with normal saline). Rat model of SAH-induced CVS was established in 90 rats, and these rats were randomly divided into the model, miR-24 NC (treated with miR-24-NC vector), miR-24 inhibitor (treated with miR-24 inhibitor vector), HMOX-NC (treated with HMOX1-NC vector), oe-HMOX1 (treated with HMOX1 overexpression vector), and miR-24 inhibitor + si-HMOX1 (treated with miR-24 inhibitor and si-HMOX1 vectors) groups. Adenoviral vectors containing the target sequences were injected into the hippocampus of the rats in the corresponding groups. Dual-luciferase reporter assay was conducted to verify the relationship between miR-24 and HMOX1. The learning and memory abilities, neurological function, cerebral edema, permeability of blood-brain barrier, myeloperoxidase activity, and levels of miR-24, HMOX1, interleukin-6, tumor necrosis factor-α, superoxide dismutase, and malondialdehyde in rats were examined.

RESULTS

miR-24 could negatively regulate HMOX1 expression. SAH-induced CVS was accompanied with increased miR-24 expression and decreased HMOX1 expression. Inhibiting miR-24 expression or enhancing the expression of its down streaming target, HMOX1, could partly reverse the increased oxidation and inflammation as well as functional deficits in the rats. Moreover, the effects of miR-24 inhibitor could be reversed by inhibiting HMOX1 expression.

CONCLUSION

miR-24 downregulation can promote HMOX1 expression, thereby decreasing the inflammatory response and improving the neurological function of rats with CVS after SAH.

Precision Medicine in Acute Brain Injury: A Narrative Review

Over the past few years, the concept of personalized medicine has percolated into the management of different neurological conditions. Improving outcomes after acute brain injury (ABI) continues to be a major challenge. Unrecognized individual multiomic variations in addition to multiple interacting processes may explain why we fail to observe comprehensive improvements in ABI outcomes even when applied treatments appear to be beneficial logically. The provision of clinical care based on a multiomic approach may revolutionize the management of traumatic brain injury, delayed cerebral ischemia after subarachnoid hemorrhage, acute ischemic stroke, and several other neurological diseases. The challenge is to incorporate all the information obtained from genomic studies, other omic data, and individual variability into a practical tool that can be used to assist clinical decision-making. The effective execution of such strategies, which is still far away, requires the development of protocols on the basis of these complex interactions and strict adherence to management protocols. In this review, we will discuss various omics and physiological targets to guide individualized patient management after ABI.

Melatonin Treatment Regulates SIRT3 Expression in Early Brain Injury (EBI) Due to Reactive Oxygen Species (ROS) in a Mouse Model of Subarachnoid Hemorrhage (SAH)

Background

A mouse model of subarachnoid hemorrhage (SAH) investigated the effects of melatonin treatment on the generation of reactive oxygen species (ROS) and the activation of the SIRT3 gene in early brain injury (EBI).

Material/Methods

Male C57BL/6J mice were assigned to three groups: the SAH group; the sham group; and the SAH + melatonin-treated group (intraperitoneal dose, 150 mg/kg). TUNEL was used to study apoptosis of neuronal cells, Western-blot and immunohistochemistry detected expression of Sirt3, Bcl-2, superoxide dismutase 2 (SOD2), Bax, and cleaved caspase-3. Real-time polymerase chain reaction (PCR) and a luciferase reporter assay evaluated the effects of melatonin on SIRT3 gene expression. Malondialdehyde (MDA) and the reactive oxygen species (ROS) scavenger, reduced glutathione (GSH), and its ratio with oxidized glutathione (GSSG) was measured.

Results

The increase in neurological score and increase in cerebral edema following SAH were reduced in the SAH + melatonin-treated group. Neuronal apoptosis following SAH was reduced in the SAH + melatonin-treated group. Increased levels of SOD2, Bax, and cleaved caspase-3 following SAH were reduced in the SAH + melatonin-treated group; reduced levels of Sirt3 and Bcl-2 following SAH were increased in the SAH + melatonin-treated group. The GSH: GSSG ratio was increased, and the MDA level was decreased when melatonin treatment was used following SAH. Melatonin upregulated SIRT3 expression by increasing the transcription efficiency of the SIRT3 promoter in human glioma cell lines U87 and U251.

Conclusions

Melatonin provided protection from the effects of EBI following SAH by regulating the expression of murine SIRT3.