Author:
Luo Yaowen,Cheng Junkai,Fu Yihao,Zhang Min,Gou Maorong,Li Juan,Li Xiaobing,Bai Jing,Zhou Yuefei,Zhang Lei,Gao Dakuan
Abstract
Abstract
Background
Ischemic stroke (IS) occurs when a blood vessel supplying the brain becomes obstructed, resulting in cerebral ischemia. This type of stroke accounts for approximately 87% of all strokes. Globally, IS leads to high mortality and poor prognosis and is associated with neuroinflammation and neuronal apoptosis. D-allose is a bio-substrate of glucose that is widely expressed in many plants. Our previous study showed that D-allose exerted neuroprotective effects against acute cerebral ischemic/reperfusion (I/R) injury by reducing neuroinflammation. Here, we aimed to clarify the beneficial effects D-allose in suppressing IS-induced neuroinflammation damage, cytotoxicity, neuronal apoptosis and neurological deficits and the underlying mechanism in vitro and in vivo.
Methods
In vivo, an I/R model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R) in C57BL/6 N mice, and D-allose was given by intraperitoneal injection within 5 min after reperfusion. In vitro, mouse hippocampal neuronal cells (HT-22) with oxygen–glucose deprivation and reperfusion (OGD/R) were established as a cell model of IS. Neurological scores, some cytokines, cytotoxicity and apoptosis in the brain and cell lines were measured. Moreover, Gal-3 short hairpin RNAs, lentiviruses and adeno-associated viruses were used to modulate Gal-3 expression in neurons in vitro and in vivo to reveal the molecular mechanism.
Results
D-allose alleviated cytotoxicity, including cell viability, LDH release and apoptosis, in HT-22 cells after OGD/R, which also alleviated brain injury, as indicated by lesion volume, brain edema, neuronal apoptosis, and neurological functional deficits, in a mouse model of I/R. Moreover, D-allose decreased the release of inflammatory factors, such as IL-1β, IL-6 and TNF-α. Furthermore, the expression of Gal-3 was increased by I/R in wild-type mice and HT-22 cells, and this factor further bound to TLR4, as confirmed by three-dimensional structure prediction and Co-IP. Silencing the Gal-3 gene with shRNAs decreased the activation of TLR4 signaling and alleviated IS-induced neuroinflammation, apoptosis and brain injury. Importantly, the loss of Gal-3 enhanced the D-allose-mediated protection against I/R-induced HT-22 cell injury, inflammatory insults and apoptosis, whereas activation of TLR4 by the selective agonist LPS increased the degree of neuronal injury and abolished the protective effects of D-allose.
Conclusions
In summary, D-allose plays a crucial role in inhibiting inflammation after IS by suppressing Gal-3/TLR4/PI3K/AKT signaling pathway in vitro and in vivo.
Funder
National Natural Science Foundation of China
Publisher
Springer Science and Business Media LLC
Subject
General Biochemistry, Genetics and Molecular Biology
Reference70 articles.
1. Hankey GJ. Stroke. Lancet. 2017;389:641–54.
2. Wang YJ, Li ZX, Gu HQ, Zhai Y, Zhou Q, Jiang Y, Zhao XQ, Wang YL, Yang X, Wang CJ. China National Clinical Research Center for Neurological. China Stroke Statistics: an update on the report from the National Center for Healthcare Quality Management in Neurological Diseases, Diseases, the Chinese Stroke Association, National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention and Institute for Global Neuroscience and Stroke Collaborations. Stroke Vasc Neurol. 2019;2022(7):415–50.
3. Nour M, Scalzo F, Liebeskind DS. Ischemia-reperfusion injury in Stroke. Interv Neurol. 2013;1:185–99.
4. DeLong JH, Ohashi SN, O’Connor KC, Sansing LH. Inflammatory responses after ischemic Stroke. Semin Immunopathol. 2022;44:625–48.
5. Zhang G, Li Q, Tao W, Qin P, Chen J, Yang H, Chen J, Liu H, Dai Q, Zhen X. Sigma-1 receptor-regulated efferocytosis by infiltrating circulating macrophages/microglial cells protects against neuronal impairments and promotes functional recovery in cerebral ischemic Stroke. Theranostics. 2023;13:543–59.