Kisspeptin‐10 Preserves the Blood‐Brain Barrier's Integrity Post‐Stroke by Augmenting Claudin‐10 Expression

The integrity of the Blood‐Brain Barrier (BBB) is crucial in the pathophysiological progression of acute ischemic stroke (AIS). However, the potential of Kisspeptin‐10 (Kp‐10), with its antioxidant and anti‐inflammatory properties, has not been explored experimentally in the context of stroke management. This study aimed to investigate the neurovascular protective effects of Kp‐10 following cerebral ischemia using both in vivo and in vitro models. A middle cerebral artery occlusion (MCAO) model was established in C57BL/6 mice, followed by Kp‐10 administration. Neurological deficits (Longa score), infarct volume (TTC staining), BBB permeability (14C‐Sucrose), and Claudin‐10 expression (qRT‐PCR and immunohistochemistry) were assessed to evaluate the therapeutic effects of Kp‐10. Human brain microvascular endothelial cells (HBMVECs) were subjected to oxygen–glucose deprivation/reoxygenation (OGD/R) to mimic ischemic conditions. Endothelial permeability, oxidative stress (OS), and nuclear factor erythroid 2‐related factor 2 (Nrf2) levels were evaluated. Nrf2 silencing was performed to validate its role in Kp‐10‐mediated protection. Initially, we observed a significant reduction in Kp‐10 expression within the cortical tissue of mice subjected to MCAO. Subsequent administration of Kp‐10 not only alleviated neurological deficits but also significantly mitigated blood–brain barrier (BBB) dysfunction following stroke induction, as evidenced by reduced 14C‐sucrose leakage. Furthermore, Kp‐10 treatment led to an upregulation of Claudin‐10 expression in the post‐stroke cortical region. In our in vitro experiments, we employed HBMVECs exposed to OGD/R to simulate ischemic conditions. We found that Kp‐10 effectively reduced OGD/R‐induced endothelial permeability by enhancing Claudin‐10 expression. Additionally, Kp‐10 exhibited antioxidant capabilities by decreasing mitochondrial reactive oxygen species (ROS) levels, increasing superoxide dismutase (SOD) activity, and upregulating nuclear factor erythroid 2‐related factor 2 (Nrf2) expression. Notably, when Nrf2 was knocked down in HBMVECs, the protective effects of Kp‐10 on endothelial permeability and Claudin‐10 expression were abolished, indicating that the beneficial actions of Kp‐10 are mediated through the Nrf2 pathway. In conclusion, our findings suggest that Kp‐10 holds promise as a therapeutic strategy to preserve BBB integrity and promote neuroprotection following stroke, acting primarily via the Nrf2 signalling pathway. These findings suggest that Kp‐10 may represent a promising therapeutic strategy for preserving BBB integrity following ischemic stroke.