Repetitive transcranial magnetic stimulation (rTMS) has increasingly been studied over the past decade to determine whether it has a therapeutic benefit on focal cerebral ischemia. However, the underlying mechanism of rTMS in this process remains unclear. In the current study, we investigated the effects of rTMS on the proliferation of adult neural stem cells (NSCs) and explored microRNAs (miRNAs) that were affected by rTMS. Our data showed that 10 Hz rTMS significantly increased the proliferation of adult NSCs after focal cerebral ischemia in the subventricular zone (SVZ), and the expression of miR-25 was obviously up-regulated in the ischemic cortex after rTMS. p57, an identified miR-25 target gene that regulates factors linked to NSC proliferation, was also evaluated, and it exhibited down-regulation. To further verify the role of miR-25, rats were injected with a single dose of antagomir-25 and were subjected to focal cerebral ischemia followed by rTMS treatment. The results confirmed that miR-25 could be repressed specifically and could drive the up-regulation of its target gene (p57), which resulted in the inhibition of adult NSC proliferation in the SVZ after rTMS. Thus, our studies strongly indicated that 10 Hz rTMS can promote the proliferation of adult NSCs in the SVZ after focal cerebral ischemia by regulating the miR-25/p57 pathway.
Cognitive impairment is a serious mental deficit caused by stroke that can severely affect the quality of a survivor's life. Repetitive transcranial magnetic stimulation (rTMS) is a well-known rehabilitation modality that has been reported to exert neuroprotective effects after cerebral ischemic injury. In the present study, we evaluated the therapeutic efficacy of rTMS against post-stroke cognitive impairment (PSCI) and investigated the mechanisms underlying its effects in a middle cerebral artery occlusion (MCAO) rat model. The results showed that rTMS ameliorated cognitive deficits and tended to reduce the sizes of cerebral lesions. In addition, rTMS significantly improved cognitive function via a mechanism involving increased neurogenesis and decreased apoptosis in the ipsilateral hippocampus. Moreover, brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), were clearly upregulated in ischemic hippocampi after treatment with rTMS. Additionally, further studies demonstrated that rTMS markedly enhanced the expression of the apoptosis-related B cell lymphoma/leukemia gene 2 (Bcl-2) and decreased the expression of the Bcl-2-associated protein X (Bax) and the number of TUNEL-positive cells in the ischemic hippocampus. Both protein levels and mRNA levels were investigated. Our findings suggest that after ischemic stroke, treatment with rTMS promoted the functional recovery of cognitive impairments by inhibiting apoptosis and enhancing neurogenesis in the hippocampus and that this mechanism might be mediated by the BDNF signaling pathway.
Background
Electroacupuncture (EA) has been commonly used to treat stroke in China. However, the underlying mechanism remains largely unknown. The present study investigated the neuroprotective effects of EA in middle cerebral artery occlusion (MCAO) rats and elucidated the possible anti-inflammatory mechanisms.
Material/Methods
In this study, modified neurological severity scoring (mNSS) was used to assess neurological deficits, and TTC staining and brain water content were measured to evaluate the degree of brain damage. HE staining, Nissl staining, and TUNEL staining were employed to evaluate apoptotic neuronal death. Molecular biological methods were used to measure the levels of miR-233, NLRP3, caspase-1, IL-1β, and IL-18 in the peri-infarct cortex.
Results
Our results showed that EA treatment significantly decreased the neurological deficit score and infarct volume of MCAO rats. The level of miR-223 was increased, while the levels of NLRP3, caspase-1, IL-1β, and IL-18 were decreased in the peri-infarct cortex of EA-treated MCAO rats. However, the neuroprotective effect of EA was partially blocked by antagomir-223.
Conclusions
These data suggest that EA treatment can alleviate neuroinflammation by inhibiting the miR-223/NLRP3 pathway, thus playing a neuroprotective role in MCAO in rats.
Severe combined immunodeficiency (SCID), a rare type of genetic associated immune disorder, is poorly characterized in mainland China. We retrospectively reviewed 44 patients with SCID who received treatment from 2004 to 2011 in Shanghai, China, and herein summarize their clinical manifestations and immunological and preliminary genetic features. The male-to-female ratio was 10:1. Twenty five patients presented with X-SCID symptoms. Only one patient was diagnosed before the onset of symptoms due to positive family history. The mean time of delay in the diagnosis of X-SCID was 2.69 months (range, 0.5-8.67). Thirty-seven of the 44 patients died by the end of 2011 with the mean age of death being 7.87 months (range, 1.33-31). Six patients received hematopoietic stem cell transplantation (HSCT); only one of them survived, who was transplanted twice. The time between onset and death was shorter in the HSCT-treated group compared with the untreated group (2.87 ± 1.28 and 3.34 ± 0.59 months, respectively), probably due to active infections during transplantation. Bacillus Calmette-Guérin (BCG) complications occurred in 14 of the 34 patients who received BCG vaccination. Transfusion-induced graft-versus-host disease occurred in 5 patients. Total 20 mutations in interleukin-2 receptor subunit gamma (IL2RG) were identified in 22 patients, including 11 novel mutations. Most patients were misdiagnosed before referred to our SCID Center. Therefore, establishing more diagnostic centers dedicated to the care of PID and accessible by primary immunodeficiency patients will facilitate early, correct diagnosis and better care of SCID in China.
Previous studies have shown that curcumin alleviates asthma in vivo. However, the relationship between curcumin and the nuclear factor-E2-related factor 2 (Nrf2)/haem oxygenase (HO)-1 pathway in asthma treatment remains unknown. The aim of the present study was to investigate the mechanisms of curcumin involved in the amelioration of airway inflammation in a mouse asthma model. Curcumin was administrated to asthmatic mice, and bronchoalveolar lavage fluid was collected. Inflammatory cell infiltration was measured by Giemsa staining. Immunoglobulin E production in bronchoalveolar lavage fluid was measured by enzyme-linked immunosorbent assay. Histological analyses were evaluated with haematoxylin-eosin and periodic acid-Schiff staining. Airway hyperresponsiveness was examined by whole-body plethysmography. Nuclear factor-E2-related factor 2, HO-1, nuclear factor-κB and inhibitory κB/p-inhibitory κB levels in lung tissues were detected by western blot, and Nrf2 activity was measured by electrophoretic mobility shift assay. Tumour necrosis factor-α, interleukin (IL)-1β, and IL-6 levels in the small interfering RNA-transfected cells were detected by enzyme-linked immunosorbent assay. Curcumin treatment significantly reduced immunoglobulin E production, attenuated inflammatory cell accumulation and goblet cell hyperplasia, and ameliorated mucus secretion and airway hyperresponsiveness. Nuclear factor-E2-related factor 2 and HO-1 levels in lung tissues were significantly increased. Meanwhile, Nrf2 activity was enhanced. Nuclear factor-κB and p-inhibitory κB levels were elevated in the lung tissue of ovalbumin-challenged mice. Both were restored to normal levels after curcumin treatment. Haem oxygenase-1 and nuclear Nrf2 levels were enhanced in dose- and time-dependent manners in curcumin-treated RAW264.7 cells. Curcumin blocked lipopolysaccharide-upregulated expression of tumour necrosis factor-α, IL-1β, and IL-6. After the cells were transfected with HO-1 or Nrf2 small interfering RNA, lipopolysaccharide-induced pro-inflammation cytokine expression was significantly restored. In summary, curcumin might alleviate airway inflammation in asthma through the Nrf2/HO-1 pathway, potentially making it an effective drug in asthma treatment.
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