Toll-like receptors (TLR2 and TLR4) antagonist mitigates the onset of cerebral small vessel disease through PI3K/Akt/GSK3β pathway in stroke-prone renovascular hypertensive rats

ABSTRACTTo examine the effect and mechanism of Toll-Like Receptors (TLR2, TLR4) antagonist in CSVD. The rat model of stroke-induced renovascular hypertension (RHRSP) was constructed. TLR2 and TLR4 antagonist was administrated by Intracranial injection. Morris water maze was used to observe the behavioral changes of rat models. HE staining, TUNEL staining and Evens Blue staining were performed to evaluate the permeability of the blood-brain barrier (BBB) and examine the CSVD occurrence and neuronal apoptosis. The inflammation and oxidative stress factors were detected by ELISA. Hypoxia-glucose-deficiency (OGD) ischemia model was constructed in cultured neurons. Western blot and ELISA were used to examine the related protein expression in TLR2/TLR4 signaling pathway and PI3K/Akt/GSK3β signaling pathway. The RHRSP rat model was successfully constructed, and the blood well and BBB permeability were altered. The RHRSP rats showed cogitative impairment and excessive immune response. After TLR2/TLR4 antagonist administration, the behavior of model rats were improved, cerebral white matter injury was reduced, and the expression of several key inflammatory factors including TLR4, TLR2, Myd88 and NF-kB were decreased, as well as the ICAM-1, VCAM-1, inflammation and oxidative stress factors. In vitro experiments showed that TLR4 and TLR2 antagonist increased the cell viability, inhibited the apoptosis, and decreased p-Akt and p-GSK3β expression. Moreover, the PI3K inhibitors resulted in decreased anti-apoptotic and anti-inflammatory effects of TLR4 and TLR2 antagonist. These results suggested that TLR4 and TLR2 antagonist achieved protective effect on the RHRSP through the PI3K/Akt/GSK3β pathway.KEYWORDS: Cerebral small vessel diseasetoll-like receptors (TLR2 and TLR4) antagonistPi3k/Akt/GSK3βapoptosisinflammation AcknowledgementsThis study were supported by the Liaoning natural fund project (2020-MS-051) and the Shenyang Science and Technology Plan Project (20-205-4-049).Disclosure statementNo potential conflict of interest was reported by the author(s).Data sharing agreementThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.Additional informationFundingThe work was supported by the Shenyang Science and Technology Plan Project [20-205-4-049]; the Liaoning natural fund project [2020-MS-051].Notes on contributorsNan WangNan Wang is a doctor and associate professor. The main research direction is vascular cognitive dysfunction.Wanshu GuoWanshu Guo is a doctor and professor. The main research direction is the diagnosis and treatment of Alzheimer's disease.Tongtong LiuTongtong Liu is a attending physician and a master's degree. The main research direction is cognitive dysfunction caused by neurological degeneration diseases.Xiaohong ChenXiaohong Chen is a professor. The main research direction is small blood vessel disease.Muhui LinMuhui Lin is a professor, mainly studying the diagnosis and treatment of small blood vessel disease and epilepsy in the direction