Rat Model Of Cerebral Infarction Research Articles

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

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

MiR-182 promotes apoptosis of neural cells in cerebral infarction rats by PI3K/AKT signaling pathway.

To explore the effects of micro ribonucleic acid (miR)-182 on the proliferation and apoptosis of neural cells in cerebral infarction rats and its underlying mechanism. The rat model of cerebral infarction was established, and neural cells were extracted accordingly. The cell proliferation ability was detected via cell counting kit-8 (CCK8) assay. In addition, the apoptosis rate was determined through flow cytometry and the activity of active caspase-3. Furthermore, the interaction between miR-182 and PI3K was explored via dual luciferase reporter assay, and the protein expression levels were observed via Western blotting. The neural cells in mouse brain tissues significantly decreased in the model group compared with that in the control group via HE stain. Additionally, the expression level of miR-182 was significantly increased in the model group compared with that in the control group. Furthermore, overexpression of miR-182 could inhibit the proliferation of neural cells through inducing cell apoptosis. Besides, the results of the luciferase reporter assay showed that the relative luciferase activity in neural cells could be inhibited by the transfection with miR-182 (P<0.05). Overexpression of miR-182 significantly reduced the protein expression levels of phosphatidylinositol 3-hydroxy kinase (PI3K) and p-AKT. MiR-182 induces apoptosis of neural cells through inhibiting the PI3K/AKT signaling pathway, which plays an important regulatory role in the apoptosis of neural cells in cerebral infarction rats.

MiR-26a improves microglial activation and neuronal apoptosis in a rat model of cerebral infarction by regulating the TREM1-TLR4/MyD88/NF-κB axis.

Emerging studies have indicated that abnormally expressed microRNAs (miRNAs) are related to the pathogenesis of cerebral ischemia. Nevertheless, the function of miR-26a in neuronal damage and microglial activation during cerebral infarction remains elusive. It was revealed that miR-26a was downregulated in oxygen-glucose deprivation (OGD)-treated microglia and neurons. Overexpressing miR-26a reduced the inflammatory reaction in BV2 cells and decreased neuronal apoptosis following OGD stimulation. miR-26a upregulation inactivated the TLR4/MyD88/NF-κB pathway and inhibited TREM1 expression. Repressing NF-κB phosphorylation inhibited the miR-26a level. As supported by the dual-luciferase reporter assay, TREM1 was directly targeted by miR-26a. Furthermore, a rat model of middle cerebral artery occlusion (MCAO) was built. We discovered that miR-26a improved cognitive, learning and motor functions and reduced cerebral edema in MCAO rats. Mechanistically, upregulating miR-26a reduced inflammation and neuronal apoptosis by mitigating the TREM1-TLR4/MyD88/NF-κB pathway in the MCAO rat model. Collectively, this study verified that the miR-26a-TREM1-TLR4/MyD88/NF-κB axis contributes to modulating OGD-mediated microglial activation and neuronal injury.

Saposhnikoviae Radix Enhanced the Angiogenic and Anti-Inflammatory Effects of Huangqi Chifeng Tang in a Rat Model of Cerebral Infarction.

Huangqi Chifeng Tang (HQCFT), a traditional Chinese formula of three herbs, has been used to treat cerebral infarction (CI). Saposhnikoviae Radix (SR) was designed as a guiding drug for HQCFT to improve its angiogenic and anti-inflammatory effects. In this study, TTC staining was used to detect the area of CI. H&E staining was used to detect the histopathologic changes in the cerebral tissue. Western blotting was performed to detect the protein expression of NLRP3, caspase 1, IL-1β, IL-6, TNF-α, MMP-9, VEGF, and VEGFR2 in cerebral tissue. Immunohistochemistry was used to detect the protein expression of MMP-9, VEGF, and VEGFR2. The contents of HIF-1α, NLRP3, caspase 1, IL-1β, IL-6, and TNF-α in the serum were determined by ELISA. Our study showed that HQCFT and HQCFT-SR could improve the pathological condition and reduce the infarcted area of the brain tissue in a rat model. In addition, HQCFT and HQCFT-SR significantly decreased the expression levels and serum contents of NLRP3, caspase 1, IL-1β, IL-6, and TNF-α; increased the expression levels of the VEGF and VEGFR2 proteins; and obviously reduced the serum content of HIF-1α. Importantly, the cytokines in brain tissue and serum from the HQCFT group exhibited better efficacy than those from the HQCFT-SR group. HQCFT exerted significant angiogenic and anti-inflammatory effects in rats subjected to middle cerebral artery occlusion (MCAO); these effects can be attributed to the guiding and enhancing effect of SR.

Different combinations of high-frequency rTMS and cognitive training improve the cognitive function of cerebral ischemic rats

Poststroke cognitive impairment (PSCI) occurs frequently after stroke, but lacks effective treatments. Previous studies have revealed that high-frequency repetitive transcranial magnetic stimulation (rTMS) has a beneficial effect on PSCI and is often used with other cognitive training methods to improve its effect. This study aimed to evaluate the effect of different combinations of rTMS and cognitive training (rTMS-COG) on PSCI and identify the optimal combination protocol. A cerebral infarction rat model was established by transient middle cerebral artery occlusion (tMCAO). The Morris water maze test was conducted to assess the cognitive function of rats. RNA sequencing and bioinformatics analysis were employed to study the underlying mechanisms. rTMS, COG and rTMS-COG all had beneficial effects on PSCI, while cognitive training immediately after rTMS (rTMS-COG0h) achieved a better effect than cognitive training 1 h and 4 h after rTMS, rTMS and COG. We identified 179 differentially expressed genes (DEGs), including 24 upregulated and 155 downregulated genes, between the rTMS-COG0h and rTMS groups. GO analysis revealed that the major categories associated with the DEGs were antigen procession and presentation, regulation of protein phosphorylation and axoneme assembly. KEGG analysis showed that the DEGs were enriched in processes related to phagosome, circadian entrainment, dopaminergic synapse, apelin signaling pathway, long-term depression, neuroactive ligand-receptor interaction, axon guidance and glucagon signaling pathway. PPI analysis identified Calb2, Rsph1, Ccdc114, Acta2, Ttll9, Dnah1, Dlx2, Dlx1, Ccdc40 and Ccdc113 as related genes. These findings prompt exploration of the potential mechanisms and key genes involved in the effect of rTMS-COG0h on PSCI.

Retraction Note to: Effects of BDNF-Transfected BMSCs on Neural Functional Recovery and Synaptophysin Expression in Rats with Cerebral Infarction.

The purpose of this study was to investigate the effects of brain-derived neurotrophic factor (BDNF)-transfected bone marrow mesenchymal stem cells (BMSCs) on neural functional recovery and synaptophysin expression in rats with cerebral infarction (CI). A total of 120 healthy Sprague Dawley rats were randomly divided into sham group, control group, and model group. Craniotomy was conducted and neurological function defect scoring was used to verify the model. BDNF containing recombinant plasmid was transfected into rat BMSCs, which was verified by flow cytometry and Western Blot. After injection of the transfected BMSCs, neural functional recovery of the CI rats and synaptophysin expression were measured. After the CI rat model was established, magnetic resonance (MR) imaging, 2, 3, 5- triphenyl tetrazolium chloride (TTC) staining, and the neurological function defect scoring determined the success of the model. CD34 (-), CD45 (−), CD29 (+), and CD90 (+) cells detected showed that the obtained BMSCs have high purity. BDNF protein was highly expressed in the BMSCs successfully transfected with the recombinant plasmid. Balance beam walking score, rotating bar walking score, and screen test score were significantly lower, while synaptophysin expression was higher in the BDNF model group than those in the non-BDNF model group and sham group with time extension. BDNF can increase synaptic plasticity and neurogenesis and have a promotional role in neural functional recovery and synaptophysin expression in rats with CI. BDNF-transfected BMSCs may therefore have better treatment efficacy for CI clinically.

Effect of Parecoxib on Hippocampus and Hypothalamic Orexin Neurons in Rats with Cerebral Infarction

Cerebral infarction has seriously threatened human life and health. Parecoxib is the first nonsteroidal analgesic for surgical analgesia. However, its effect on orexin neurons during cerebral infarction treatment is unclear. In this study, a rat model of cerebral infarction was established by suture method. The experiment was assigned into sham operation group, cerebral infarction model group (MCAO), high and low dose group of parecoxib. Western blotting and immunofluorescence staining was used to evaluate the activity of orexin neurons. The infarct size was evaluated by TTC staining. The apoptosis of neurons in hypothalamus and hippocampus was determined by AV-PI staining. TTC staining suggested that parecoxib treatment significantly reduced cerebral infarct size, increased orexin neuronal activity, and decreased neuronal apoptosis in hypothalamus and hippocampus, which were significantly different from sham-operated groups. This study demonstrates that parecoxib has a protective effect on cerebral infarction rats, which can inhibit the apoptosis of hypothalamic and hippocampal neurons through the orexin neuron pathway. It provides a theoretical basis for the protective effect of parecoxib, indicating that it might be a new target for the treatment of cerebral infarction.

Morin Provides Neuroprotection in a Model of Cerebral Infarction Via Nrf-2 Signaling Pathway

Cerebral infarction, also known as ischemic stroke, is a disorder of blood supply in the local brain tissue and the second leading cause of death worldwide. It is important to develop effective drugs to treat cerebral infarction. Morin (3,5,7,2′, 4′-pentahydroxyflavone) is a bioactive flavonol that has multiple medicinal properties including antioxidant, anti-inflammatory, anti-invasive, antitumor, and antiangiogenic properties. However, its potential effect on ischemic stroke as a potent neuroprotective and cardioprotective agent remains unknown. In this study, we constructed a rat model of cerebral infarction and shown morin to be neuroprotective in this model. Additionally, morin inhibited nerve cell apoptosis and cerebral infarction induced oxidative stress in brain tissue. Our data further confirmed that morin provides neuroprotection in cerebral infarction via upregulation of the downstream proteins of Nrf2 pathway. We therefore suggest morin as a promising therapeutic drug for the treatment of cerebral infarction.

RETRACTION NOTICE: Tanshinone inhibits neuronal cell apoptosis and inflammatory response in cerebral infarction rat model.

RETRACTION NOTICE: Tanshinone inhibits neuronal cell apoptosis and inflammatory response in cerebral infarction rat model.

The Potential of Hydrogen for Improving Mental Disorders.

In 2007, Ohsawa and colleagues reported that molecular hydrogen (H2) gas significantly reduced the infarct volume size in a rat model of cerebral infarction, which was, at least, partially due to scavenging hydroxyl radicals. Since then, multiple studies have shown that H2 has not only anti-oxidative but also anti-inflammatory and anti-apoptotic properties, which has ignited interest in the clinical use of H2 in diverse diseases. A growing body of studies has indicated that H2 affects both mental and physical conditions. Mental disorders are characterized by disordered mood, thoughts, and behaviors that affect the ability to function in daily life. However, there is no sure way to prevent mental disorders. Although antidepressant and antianxiety drugs relieve symptoms of depression and anxiety, they have efficacy limitations and are accompanied by a wide range of side effects. While mental disorders are generally thought to be caused by a variety of genetic and/or environmental factors, recent progress has shown that these disorders are strongly associated with increased oxidative and inflammatory stress. Thus, H2 has received much attention as a novel therapy for the prevention and treatment of mental disorders. This review summarizes the recent progress in the use of H2 for the treatment of mental disorders and other related diseases. We also discuss the potential mechanisms of the biomedical effects of H2 and conclude that H2 could offer relief to people suffering from mental disorders.

The intranasal administration of Carthamus tinctorius L. extract/phospholipid complex in the treatment of cerebral infarction via the TNF-α/MAPK pathway

Carthamus tinctorius L.(Safflower), a herbal formula from Traditional Chinese Medicine (TCM), has been widely used for the treatment of cardio-cerebrovascular diseases, particularly cerebral infarction (CI) or cerebral ischemia-reperfusion injury. However, we know very little about the specific mechanisms associated with the therapeutic effect of Safflower on CI. In this study, we used a network pharmacology-based approach, together with rat model of CI, to gain more insight into of such mechanisms. Our analysis showed that Safflower contains 52 active compounds that target 247 genes, which were also cross-referenced with 299 genes associated with CI. Consequently, we identified 52 target genes in Safflower that were associated with CI. These 52 target genes were analyzed by gene ontology (GO) enrichment analysis, leading to the identification of 1491 biological process items, 90 molecular function items and 19 cell assembly items. Eighty-nine pathways were generated by KEGG enrichment (P < 0.05). Next, we investigated the effect of the extract of safflower (ES) and Safflower extract phospholipid complex (ESPC), delivered via the nasal route, on an animal model of the middle cerebral artery occlusion (MCAO). Our data confirmed that Safflower was able to treat CI by the regulating the TNF-α/MAPK pathway via CASP3. The therapeutic effect of ES and ESPC on CI acts by improving the circulation of blood in the central nervous system, reducing the inflammatory reaction, inhibiting apoptosis, and by protecting brain nerve cells from injury.

Effects of exercise timing and intensity on neuroplasticity in a rat model of cerebral infarction

Exercise therapy plays key roles in functional improvements during neurorehabilitation. However, it may be difficult for some people to properly perform exercise because mobility and endurance might be restricted by neurological deficits due to stroke. Additionally, there is little evidence detailing the biological mechanisms underlying the most effective swimming exercise protocols for neuroplasticity after stroke. Thus, the present study investigated the effects of swimming exercise on neuroplasticity in a cerebral infarction rat model according to the timing and intensity of exercise. A total of 45 male Sprague-Dawley rats (300 ± 50 g, 10 weeks old) were subjected to photothrombotic cerebral infarction and randomly divided into five groups: non-exercise (group A, n = 9); early submaximal (group B, n = 9); early maximal (group C, n = 9); late submaximal (group D, n = 9); and late maximal (group E, n = 9). Swimming exercise was performed five times a week for 4 weeks, and cognition was evaluated with the Morris water maze (MWM) test. Assessments of superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels and immunohistochemical analyses of brain-derived neurotrophic factor (BDNF) were conducted in the ipsilesional hippocampus region. After 4 weeks of exercise, the escape latency was shorter and velocity was greater in group B than in groups A, C, D, and E (p = 0.046, p < 0.001, respectively). Furthermore, SOD activity was higher and MDA levels were lower in group B than in groups A, C, D, and E (p = 0.004, p = 0.019). The immunohistochemistry results revealed that the greatest BDNF immunoreactivity was in group B. Taken together, these results indicate that early submaximal swimming exercise may be the most effective protocol for the recovery of neurological deficits in a rat model of cerebral infarction.

Protective Effects of Naringin in Cerebral Infarction and Its Molecular Mechanism.

BackgroundCerebral infarction is a cardiovascular disease with high morbidity and mortality. At present, many studies have reported the treatment of cerebral infarction by traditional Chinese medicine. Naringin, a flavonoid, is a major traditional Chinese medicine. However, the effect and mechanism of naringin on cerebral infarction is unclear.Material/MethodsIn our study, we established a rat model of cerebral infarction through middle cerebral artery occlusion (MCAO) to study the influence of naringin on cerebral infarction in vivo. After treatment with naringin, brain water content was detected to assess brain edema. Cerebral infarction volume and neurological deficits were also measured. Production of the inflammatory factors tumor necrosis factor (TNF)-α and interleukin (IL)-6) was measured using enzyme-linked immunosorbent assay (ELISA). Besides, the effect of naringin on cerebral infarction was investigated in vitro by establishing an oxygen-glucose deprivation (OGD) model in neuronal cells. Cell apoptosis and cell viability was determined using flow cytometry and MTT assay.ResultsWe found that naringin pretreatment significantly decreased the brain water content, cerebral infarction volume, and neurological deficit scores of MCAO subjected rats. And naringin treatment reduced apoptosis of nerve cells in rat hippocampus and the secretion of inflammatory factor such as TNF-α and IL-6. Besides, we found that naringin increased cell viability and inhibited apoptosis in OGD induced neuronal cells. Finally, we found that naringin promoted the expression of p-AKT protein in a concentration-dependent manner and activated the PI3K/AKT pathway in OGD induced neurons.ConclusionsNaringin played a protective role in cerebral infarction via suppressing neuronal apoptosis and inflammation.

Influences of urinary kallidinogenase on neuronal apoptosis in cerebral infarction rats through Nrf2/ARE oxidative stress pathway.

To investigate the influences of urinary kallidinogenase on neuronal apoptosis in rats with cerebral infarction through the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) oxidative stress pathway. A total of 30 male rats were divided into group A (model control group), group B (rat model of cerebral infarction) and group C (rat model of cerebral infarction + medical treatment with urinary kallidinogenase). The percentage of cerebral infarct volume and the apoptosis of brain cells in the three groups of rats were detected via 2,3,5-Triphenyltetrazolium chloride (TTC) staining, the pathological morphology of brain tissues in the three groups of rats was observed via hematoxylin and eosin (HE) staining, and the protein levels of Nrf2 and superoxide dismutase 1 (SOD1) in the brain tissues in the three groups of rats were measured using the Western blotting assay. The degree of neurological deficit in group B was remarkably higher than that in group A (p<0.05), and it was markedly decreased in group C compared to that in group B, displaying statistically significant differences (p<0.05). Compared to that in group A, the cell apoptosis was significantly aggravated in group B, while a remarkably alleviated cell apoptosis was observed in group C compared to that of group B, and the differences were statistically significant (p<0.05). The cerebral infarct volume accounted for 34.87% of the whole brain volume in group B, and a mild cerebral infarction was detected in group C, with a percentage of cerebral infarct volume of 21.14%. Group B showed a more evident increase in the cerebral infarct volume than in group C (p<0.05). Compared to those of group A, pyknotic nuclei and neuron staining of brain tissue cells were evidently increased, and the neuronal cell injury was aggravated in group B. Moreover, prominently decreased pyknotic nuclei and neuron staining (p<0.05) as well as mild neuronal cell injury (p<0.05) were detected in group C compared to those in group B. The levels of Nrf2 and SOD1 protein in the brain tissues in group B were remarkably lower than those of group C (p<0.05). Urinary kallidinogenase can inhibit the neuronal apoptosis in rats and protect the rats from cerebral infarction, whose mechanism is associated with the activation of the Nrf2/ARE oxidative stress pathway.

3-N-butylphthalide inhibits neuronal apoptosis in rats with cerebral infarction via targeting P38/MAPK.

To study the effect of 3-n-butylphthalide (NBP) on neuronal apoptosis in rats with cerebral infarction (CI) through the p38/mitogen-activated protein kinase (MAPK) pathway. A total of 30 rats were divided into control group (healthy rats, n=10), model group (CI rat model, n=10), and NBP group (CI rat model + intraperitoneal injection of NBP, n=10). Then, the neurological function, degree of cerebral ischemia, apoptosis of brain tissues, the protein and messenger ribonucleic acid (mRNA) expressions of p-p38 and MAPK in brain tissues were detected using the neurological score, 2,3,5-triphenyltetrazolium chloride (TTC) staining, Reverse Transcription-Polymerase Chain Reaction (RT-PCR), terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and Western blotting, respectively. In NBP group, the neurological score was significantly lower than in model group, and the difference was statistically significant (p<0.05). The results of TTC staining revealed that the area of the white region in brain slices was significantly larger in model group than in control group, indicating the successful establishment of middle cerebral artery occlusion (MCAO) model. Compared with model group, NBP group had a smaller area and lighter color of the white region in brain slices, suggesting that NBP markedly reduces the MCAO-induced CI. The apoptosis rate in NBP group was higher than in control group (p<0.05), but lower than in model group (p<0.05), while it was higher in model group than in control group (p<0.05). The protein expressions of p38 and MAPK in NBP group were higher than in control group (p<0.05), but lower than in model group (p<0.05), while they were higher in model group than in control group (p<0.05). Moreover, the mRNA expressions of p38 and MAPK were lower in control group than in model group (p<0.05), while they were higher in model group than in NBP group (p<0.05), but there was no significant difference in the mRNA expression of p38 between NBP group and control group (p>0.05). NBP alleviates neuronal apoptosis in CI by down-regulating the p38 signal and inhibiting the expression of MAPK, thereby treating CI.

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.

LncRNA SNHG1 inhibits neuronal apoptosis in cerebral infarction rats through PI3K/Akt signaling pathway.

To investigate the effects of long non-coding ribonucleic acid (lncRNA) small nucleolar RNA host gene 1 (SNHG1) on the neuronal apoptosis in rats with cerebral infarction through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Male Sprague Dawley (SD) rats were divided into M group (model control group), N group (rat model of cerebral infarction) and R group (rat model of cerebral infarction plus lncRNA SNHG1) and then treated accordingly. 2,3,5-triphenyl tetrazolium chloride (TTC) staining was applied to detect the percentage of cerebral infarct volume and apoptosis of brain cells in the three groups of rats; hematoxylin and eosin (HE) staining was utilized to observe the pathological morphology of brain tissues, and Western blotting was performed to measure the protein levels of phosphorylated PI3K (p-PI3K) and p-Akt in the brain tissues. The degree of neurological deficit in the N group was much higher than that in the M group (p<0.05), and it was decreased markedly in the R group compared with that in the N group, with statistically significant differences (p<0.05). In comparison with that in the M group, the cell apoptosis was aggravated notably in the N group and alleviated remarkably in the R group, and the differences were statistically significant (p<0.05). In the N group, the cerebral infarct volume accounted for 33.67% of the whole brain volume, and mild cerebral infarction was detected in the R group, with a percentage of cerebral infarct volume of 20.15%. N group had a more prominent increase in the cerebral infarct volume than the R group (p<0.05). Compared with those in the M group, the pyknotic nuclei and neuron staining of brain tissues were increased significantly, and the neuronal cell injury was aggravated in the N group, while markedly reduced pyknotic nuclei and neuron staining (p<0.05), as well as mild neuronal cell injury (p<0.05), were detected in the R group. The levels of p-PI3K and p-Akt proteins in the brain tissues declined remarkably in the N group compared with those in the R group (p<0.05). The protective effect of lncRNA SNHG1 on the rats with cerebral infarction is correlated with the activation of the PI3K/Akt signaling pathway.

MicroRNA-323 suppresses nerve cell toxicity in cerebral infarction via the transforming growth factor-β1/SMAD3 signaling pathway.

In the present study, the aim was to investigate the function of microRNA‑323 (miR‑323) in cerebral infarction and its underlying mechanism. A rat model of cerebral infarction was established and hippocampal tissues were analyzed. In addition, to further understand the role of miR‑323, PC12 cells were transfected with miR‑323 mimics or inhibitors and subjected to hypoxia to model cerebral infarction. Reverse transcription‑quantitative polymerase chain reaction was used to measure the expression of miR‑323. A luciferase reporter assay was conducted to analyze miR‑323 target sites the partial sequence of the 3'‑untranslated region of SMAD3 mRNA in vitro. Western blot analysis was also used to analyze transforming growth factor‑β1 (TGF‑β1) and SMAD3 protein expression levels. It was observed that miR‑323 expression was significantly upregulated in rats with cerebral infarction compared with rats in the sham‑control group. In addition, overexpression of miR‑323 induced nerve cell toxicity and reduced nerve cell growth in an in vitro model of cerebral infarction, whereas downregulation of miR‑323 caused the opposite effects on nerve cell toxicity and growth in this model. In addition, overexpression of miR‑323 directly targeted and suppressed SMAD3 expression in the in vitro model of cerebral infarction, while inhibition of miR‑323 induced SMAD3 expression. The use of a SMAD3 inhibitor suppressed the effect of anti‑miR‑323 on nerve cell toxicity in the in vitro model of cerebral infarction. Collectively, these findings suggested that miR‑323 suppresses nerve cell apoptosis in cerebral infarction via the TGF‑β1/SMAD3 signaling pathway.

Effect of regular swimming exercise to duration-intensity on neurocognitive function in cerebral infarction rat model

ABSTRACTObjective: This study investigated the effect of regular swimming exercise according to the duration-intensity on neurocognitive function in a cerebral infarction rat model.Methods: Forty male Sprague–Dawley 10-week-old rats, weighing 300 ± 50 g, were subjected to photothrombotic cerebral infarction. The remaining 36 rats were randomly divided into four groups (n = 9 per group: non-exercise (group A); swimming exercise of short duration-intensity (5 min/day, group B); swimming exercise of moderate duration-intensity (10 min/day, group C); and swimming exercise of long duration-intensity (20 min/day, group D). Exercise was performed five times a week for 4 weeks, beginning the day after cerebral infarction. Neurocognitive function was evaluated with the Morris water maze test. Immunohistochemistry and western blot analysis examined brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) at 4 weeks postinfarction.Results: At 4 weeks postinfarction, escape latency was found to be shorter in group C than in any of groups A, B, or D. Immunohistochemistry revealed the most significant immunoreactivity for BDNF and VEGF in group C. Western blot analysis demonstrated that BDNF and VEGF proteins were markedly expressed in group C.Conclusions: Regular swimming exercise of moderate duration-intensity may be the most effective exercise protocol for the recovery of neurocognitive function in cerebral infarction rat model.

Intravenous infusion of mesenchymal stem cells promotes functional recovery in a rat model of chronic cerebral infarction.

OBJECTIVE: Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow improves behavioral function in rat models of cerebral infarction. Although clinical studies are ongoing, most studies have focused on the acute or subacute phase of stroke. In the present study, MSCs derived from bone marrow of rats were intravenously infused 8 weeks after the induction of a middle cerebral artery occlusion (MCAO) to investigate whether delayed systemic injection of MSCs improves functional outcome in the chronic phase of stroke in rats. METHODS: Eight weeks after induction of the MCAO, the rats were randomized and intravenously infused with either MSCs or vehicle. Ischemic volume and behavioral performance were examined. Blood-brain barrier (BBB) integrity was assessed by quantifying the leakage of Evans blue into the brain parenchyma after intravenous infusion. Immunohistochemical analysis was also performed to evaluate the stability of the BBB. RESULTS: Motor recovery was better in the MSC-treated group than in the vehicle-treated group, with rapid improvement (evident at 1 week post-infusion). In MSC-treated rats, reduced BBB leakage and increased microvasculature/repair and neovascularization were observed. CONCLUSIONS: These results indicate that the systemic infusion of MSCs results in functional improvement, which is associated with structural changes in the chronic phase of cerebral infarction, including in the stabilization of the BBB.