Hypoxic preconditioning improves the survival and neural effects of transplanted mesenchymal stem cells via CXCL12/CXCR4 signalling in a rat model of cerebral infarction.

The treatment of neural deficiency after cerebral infarction is challenging, with limited therapeutic options. The transplantation of mesenchymal stem cells (MSCs) to the ischemic penumbra is a potential therapeutic approach. In the present study, a cerebral infarction model was generated by performing middle cerebral artery occlusion (MCAO) in SD rats. The expression of CXCR4 increased, and the number of MSCs migrating to the peri-infarct area was higher in rats transplanted with preconditioned MSCs than in rats transplanted with untreated MSCs. The rate of apoptosis, as evaluated by TUNEL staining and immunoblotting assays, was reduced in rats receiving preconditioned MSCs. A significant amelioration of neural regeneration and improved neurological function were observed in rats injected with preconditioned MSCs compared with those injected with untreated MSCs. However, the application of an siRNA targeting CXCL12 significantly inhibited the protective role of preconditioned MSCs against apoptosis and promoted the migration of MSCs to the ischemic area, leading to impaired neuronal regeneration and limited recovery of neuronal function. Hypoxic preconditioning of MSCs prior to transplantation suppressed apoptosis and increased their migration abilities, leading to the promotion of neuronal regeneration and improvement in neural function after transplantation. This preconditioning strategy may be considered as a potential approach for the modification of MSCs prior to cell transplantation therapy in patients with cerebral infarction. SIGNIFICANCE OF THE STUDY: We found that hypoxic preconditioning of MSCs improved their ability to promote neuronal regeneration and the recovery of neuronal function. Moreover, we showed that CXCR4 inhibited apoptosis, improved cell homing, and promoted neuronal differentiation, without influencing angiogenesis. Our study provides a relatively safe preconditioning method for potential use for cell transplantation therapy in ischemic cerebral infarction. The results presented here will facilitate the development of novel strategies and techniques to improve the tolerance and migration ability of transplanted cells for the treatment of cerebral infarction sequelae.

Association of C-reactive protein gene polymorphisms with the risk of ischemic stroke: A systematic review and meta-analysis.

BACKGROUND AND PURPOSE: The heterogeneous, complex condition known as ischemic stroke (IS) is brought on by the interaction of a number of risk factors and genetic variables. The association between C-reactive protein (CRP) gene polymorphisms and IS has, however, been the subject of inconsistent findings. Therefore, we conducted a meta-analysis to comprehensively address possible associations of CRP genes with the risk of IS. METHODS: A comprehensive literature search for all the published articles was performed in electronic databases including PubMed, EMBASE, Cochrane Library, and Google Scholar from January 1, 1950 to June 30, 2022. Odds ratio (OR) with 95% Confidence interval (CIs) along with fixed/random effect models were used to calculate summary estimates. RESULTS: Twelve case-control studies totalling 3880 IS cases and 5233 controls were included for the association of CRP gene polymorphisms (rs1800947, rs1130864, rs3093059, rs2794521, and rs1205). Across all genotyping models, we discovered that rs1130864, rs3093059, rs2794521, and rs1205SNPs were not substantially related to IS risk. A trend for significant association for rs1800947 under dominant (OR = 1.19; 95% CI = 0.97 to 1.48), recessive (OR = 1.49; 95% CI = 0.71 to 3.14) and allelic model (OR = 1.21; 95% CI = 0.99 to 1.48) was observed. However, protective association for rs1130864 under dominant (OR = 0.80; 95% CI = 0.70 to 0.91) and rs3093059 under allelic model (OR = 0.18; 95% CI = 0.14 to 0.22) was found. CONCLUSION: Our thorough study revealed that the CRP gene variants rs1800947, rs1130864, rs3093059, rs2794521, and rs1205 could not be related to the risk of ischemic stroke. However, additional research must focus on the rs1800947 polymorphisms in a particular group.

Notoginsenoside R2 reduces Aß25-35-induced neuronal apoptosis and inflammation via miR-27a/SOX8/ß-catenin axis.

Background: Alzheimer's disease (AD) has affected numerous elderly individuals worldwide. Panax notoginseng has been shown to ameliorate AD symptoms, and notoginsenoside R2 is a key saponin identified in this plant. Purpose: In the current study, we aimed to explore whether notoginsenoside R2 could improve the prognosis of AD. Methods: Herein, primary rat cortical neurons were isolated and they were treated with amyloid beta-peptide (Aß) 25-35 oligomers. Cellular apoptosis was examined via flow cytometry and Western blotting. miR-27a and SOX8 mRNA expression levels were quantified by quantitative reverse transcription-polymerase chain reaction. Furthermore, the interaction between miR-27a and SOX8 was investigated by utilizing a dual-luciferase reporter assay. Finally, an AD mouse model was established to validate the in vitro findings. Results: Notoginsenoside R2 alleviated Aß25-35-triggered neuronal apoptosis and inflammation. During this process, miR-27a expression was decreased by notoginsenoside R2, and miR-27a negatively modulated SOX8 expression. Furthermore, activation of SOX8 upregulated ß-catenin expression, thus suppressing apoptosis and neuroinflammation. Conclusions: Our animal experiments revealed that notoginsenoside R2 enhanced the cognitive function of AD mice and inhibited neuronal apoptosis. Notoginsenoside R2 ameliorated AD symptoms by reducing neuronal apoptosis and inflammation, thus suggesting a novel direction for AD pharmacotherapy.

Nanomedicines, an emerging therapeutic regimen for treatment of ischemic cerebral stroke: A review.

Owing to its intricate pathophysiology, cerebral stroke is a serious medical condition caused by interruption or obstruction of blood supply (blockage of vasculature) to the brain tissues which results in diminished supply of essential nutrients and oxygen (hypoxia) and ultimate necrosis of neuronal tissues. A prompt risks assessment and immediate rational therapeutic plan with proficient neuroprotection play critically important role in the effective management of this neuronal emergency. Various conventional medications are being used for treatment of acute ischemic cerebral stroke but fibrinolytic agents, alone or in combination with other agents are considered the mainstay. These clot-busting agents effectively restore blood supply (reperfusion) to ischemic regions of the brain; however, their clinical significance is hampered due to various factors such as short plasma half-life, limited distribution to brain tissues due to the presence of highly efficient physiological barrier, blood brain barrier (BBB), and lacking of target-specific delivery to the ischemic brain regions. To alleviate these issues, various types of nanomedicines such as polymeric nanoparticles (NPs), liposomes, nanoemulsion, micelles and dendrimers have been designed and evaluated. The implication of these newer therapies (nanomedicines) have revolutionized the therapeutic outcomes by improving the plasma half-life, permeation across BBB, efficient distribution to ischemic cerebral tissues and neuroprotection. Furthermore, the adaptation of some diverse techniques including PEGylation, tethering of targeting ligands on the surfaces of nanomedicines, and pH responsive features have also been pondered. The implication of these emerging adaptations have shown remarkable potential in maximizing the targeting efficiency of drugs to ischemic brain tissues, simultaneous delivery of drugs and imaging agents (for early prognosis as well as monitoring of therapy), and therapeutic outcomes such as long-term neuroprotection.

Ferritin reduction is essential for cerebral ischemia-induced hippocampal neuronal death through p53/SLC7A11-mediated ferroptosis.

Cerebral ischemia is the most common cause of hippocampal neuronal death and the most prevalent cause of stroke with high mortality rate. Ferroptosis has been suggested to affect the role of hippocampal neurons. This study explores the influence of lentivirus infection-induced ferritin overexpression in hippocampal neuronal injury and death through simulations in August Copenhagen Irish rat models. Twenty-four-hour cerebral ischemia-reperfusion injury was induced in the rats after 90-min middle cerebral artery occlusion (MCAO). Ferritin overexpression was induced through lentivirus infection. The Morris Water Maze (MWM) test and tau hyperphosphorylation test were performed on hippocampal neurons to establish a MCAO model. The effect of ferritin overexpression on hippocampal neuronal death was evaluated using hematoxylin-eosin staining and annexin V/propidium iodide flow cytometry. The MWM test revealed that MCAO modeling decreased the cognitive and locomotor capacity of the rats, whereas ferritin overexpression partially reversed the effect of MCAO. In addition, the hyperphosphorylation of tau caused by MCAO was reduced by ferritin. Pathogenic changes, impaired viability, increased apoptosis, and elevated caspase-9 cleavage in hippocampal neurons were clearly recovered by ferritin. Moreover, robust reactive oxygen species production and glutathione consumption, which was induced by MCAO modeling, were ameliorated by ferritin. Furthermore, two key modulators of ferroptosis, p53 and SLC7A11, were demonstrated to be upregulated by MCAO modeling and downregulated by ferritin. Ferritin reduction is essential for cerebral ischemia-induced hippocampal neuronal ferroptosis mediated via p53 and SLC7A11.

MicroRNA-107 Ameliorates Damage in a Cell Model of Alzheimer's Disease by Mediating the FGF7/FGFR2/PI3K/Akt Pathway.

Alzheimer's disease (AD), the most prevalent representation of dementia, is a neurodegenerative disease resulting from the degenerative disturbance of the central nervous system. Previous studies have indicated that miR-107 is reduced in the brain neocortex of patients with AD; however, its underlying mechanism is not clear. Therefore, the objective of this study was to explore the question of whether miR-107 participates in AD development. The study confirmed that the miR-107 expression levels were dramatically decreased in patients with AD and in beta-amyloid (Aß) (Aß)-treated SH-SY5Y cells compared with control groups. Upregulation of miR-107 reversed the inhibitory role of Aß on cell proliferation and viability. In addition, miR-107 upregulation also ameliorated the Aß-induced inflammation and apoptosis of SH-SY5Y cells. Furthermore, using bioinformatic prediction, dual-luciferase reporter assay (DLRA), quantitative polymerase chain reaction (qPCR), and Western blot (WB), miR-107 was confirmed to reduce the expression level of FGF7, and it subsequently deactivated the FGFR2/PI3K/Akt pathway. Moreover, FGF7 overexpression counteracted the role of miR-107 in the viability, proliferation, inflammation, and apoptosis of Aß-induced SH-SY5Y cells.

TGF-ß1 Restores Hippocampal Synaptic Plasticity and Memory in Alzheimer Model via the PI3K/Akt/Wnt/ß-Catenin Signaling Pathway.

Alzheimer's disease (AD) is the most common neurodegenerative disturbances. Dysfunction of synaptic plasticity and decline in cognitive functions are the most prominent features of AD, but the mechanisms of pathogenesis have not been well elucidated. In this paper, transforming growth factor-ß1 (TGF-ß1) was found to be reduced in the hippocampus of AD mouse which was accompanied by impaired pine density, synaptic plasticity, and memory function. Hippocampal injection of TGF-ß1 rescued the AD-induced memory function impairment. In addition, TGF-ß1 ameliorated synaptic plasticity and increased synaptic plasticity-associated protein expression including Arc, NR2B, and PSD-95 in mouse model of AD. Furthermore, we demonstrated that Akt/Wnt/ß-catenin pathway protein expression in the hippocampus was suppressed in a mouse model of AD and TGF-ß1 significantly enhanced the phosphorylation Akt, GSK3ß, and increased the nuclear ß-catenin. These results indicate that TGF-ß1activates PI3K/Akt/Wnt/ß-catenin signaling in mouse model of AD, which is important for promoting synaptic plasticity related to memory function. More importantly, suppression of PI3K/Akt/Wnt/ß-catenin pathway compromised the beneficial effects of TGFß1 in Alzheimer's model. Hence, TGF-ß1 shows protective effect on neurons, which might be through the PI3K/Akt/Wnt/ß-catenin signaling pathway, serving as a potential target in AD pathology.

Curcumin Reduces Neuronal Loss and Inhibits the NLRP3 Inflammasome Activation in an Epileptic Rat Model.

BACKGROUND: Epilepsy is a chronic neurological disorder affecting an estimated 50 million people worldwide. Emerging evidences have accumulated over the past decades supporting the role of inflammation in the pathogenesis of epilepsy. Curcumin is a nature-derived active molecule demonstrating anti-inflammation efficacy. However, its effects on epilepsy and corresponding mechanisms remain elusive. OBJECTIVE: To investigate the effects of curcumin on epilepsy and its underlying mechanism. METHOD: Forty Sprague Dawley rats were divided into four groups: (1) control group; (2) Kainic Acid (KA)-induced epilepsy group; (3) curcumin group; and (4) curcumin pretreatment before KA stimulation group. Morris water maze was utilized to assess the effect of curcumin on KA-induced epilepsy. The hippocampi were obtained from rats and subjected to western blot. Immunohistochemistry was conducted to investigate the underlying mechanisms. RESULTS: Rats received curcumin demonstrated improvement of recognition deficiency and epilepsy syndromes induced by KA. Western blot showed that KA stimulation increased the expression of IL-1ß and NLRP3, which were reduced by curcumin treatment. Further investigations revealed that curcumin inhibited the activation of NLPR3/inflammasome in epilepsy and reduced neuronal loss in hippocampus. CONCLUSION: Curcumin inhibits KA-induced epileptic syndromes via suppression of NLRP3 inflammasome activation; therefore, offers a potential therapy for epilepsy.

Mechanism of action of Zhuyu Annao pill in mice with cerebral intrahemorrhage based on TLR4.

OBJECTIVE: To explore the protective effect and possible mechanism of action of Zhuyu Annao pill in mice with intracerebral hemorrhage (ICH). METHODS: Sixty mice were divided into the control group, hemorrhage group, drug-treated group (after hemorrhage), TLR4-knockout hemorrhage group and TLR4-knockout hemorrhage + drug-treated group (after hemorrhage) with 12 in each group. Model of autologous ICH was established in all groups. After drilling and 12 h of fasting, models in the control group hemorrhage group and TLR4-knockout hemorrhage group were all drenched with 10 mL/kg distilled water by intragastric administration. Models in the drug-treated group and TLR4-knockout hemorrhage + drug-treated group were drenched with 6.25 g/kg of Zhuyu Annao pill. All groups were treated for 7 d. Longa scoring method was used to measure the neurological defect scores and determine the brain water contents of all groups; ELISA was employed to detect the inflammatory factor interleukin (IL)-6, tumor necrosis factor-α (TNF-α) and IL-1ß in brain tissues; and Western blot was applied to test the expression quantities of apoptotic protein Bax and anti-apoptotic protein Bcl-2 in brain tissues. RESULTS: At day 3 and 7, compared with the hemorrhage group, the neurological defect scores of the drug-treated group, TLR4-knockout hemorrhage group and TLR4-knockout hemorrhage + drug-treated group decreased significantly (P < 0.05). Compared with the hemorrhage group, the brain water contents of the drug-treated group, TLR4-knockout hemorrhage group and TLR4-knockout hemorrhage + drug-treated group reduced significantly (P < 0.05). Compared with the hemorrhage group, the inflammatory factor IL-6, TNF-α and IL-1ß of the drug-treated group, TLR4-knockout hemorrhage group and TLR4-knockout hemorrhage + drug-treated group decreased significantly (P < 0.05). Compared with the hemorrhage group, the expression of apoptotic protein Bax of the drug-treated group, TLR4-knockout hemorrhage group and TLR4-knockout hemorrhage + drug-treated group decreased significantly and the expression of anti-apoptotic protein Bcl-2 increased significantly (P < 0.05). CONCLUSIONS: Zhuyu Annao pill can alleviate encephaledema for mice with ICH and reduce inflammatory responses and nerve cell apoptosis. TLR4 can mediate inflammatory injury induced by ICH. Thus, Zhuyu Annao pill can play a protective role for brains by decreasing the expression of TLR4.