Background: Dyslipidemia during midlife represents a significant risk factor for neuropathological alterations associated with cognitive decline. Given the currently incurable nature of dementia, implementation of preventive strategies and early therapeutic interventions prior to disease progression are paramount. Emerging evidence suggests that hyperbaric oxygen (HBO) therapy exhibits neuroprotective properties in various neurological conditions. However, whether HBO treatment modulates lipid metabolism dysregulation and subsequent neurodegeneration remains unanswered. This investigation aimed to elucidate the therapeutic potential of HBO treatment in ameliorating cerebral dysfunction and metabolic perturbations using apolipoprotein E (ApoE)-deficient (ApoE-/-) mice. Methods: ApoE-/- mice received HBO treatment for 10 consecutive days, and then behavioral assessment tests were performed. Serum and brain tissue were collected to measure oxidative stress levels and inflammatory factors. Results: Compared with ApoE-/- group, cognitive declines was significantly reversed in mice of the ApoE-/-+HBO mice. The blood lipid profiles of ApoE-/- mice were also improved after HBO treatment, accompanied by a reduction in body weight. Moreover, HBO treatment was found to ameliorates neuronal injury and amyloid-β deposition in the hippocampus of ApoE-/- mice. Further studies have revealed that the benefits of HBO treatment occurred through the reduction of inflammatory factors and attenuation of oxidative stress. Conclusions: These findings indicate that HBO treatment effectively improves the intracerebral microenvironment of ApoE-/- mice, providing a novel regulatory mechanism of protection against dyslipidemia-associated brain deficits by HBO treatment.
As a novel form of repetitive transcranial stimulation, intermittent theta burst stimulation (iTBS) has potentials to be widely used in patients with stroke. Yet little is known about the idiographic actions of iTBS with different stimulation parameters on rehabilitative aspects of stroke patients, nor is the molecular mechanism underlying. In the present study, effects of iTBS with different stimulation parameters were evaluate to identify the optimal protocol of iTBS against damage induced by ischemia/reperfusion (I/R). Herein we found the short-term iTBS application seemed to have no significant effects on outcomes of rats during acute phase after I/R, including the neurological deficits, cerebral infarction and edema. However, behavioral functional tests demonstrated that long-term iTBS treatment provided effective therapy during subacute stage after two weeks post-stroke onset, which possibly by increasing proliferation and migration of adult neural stem cells. To explore the possible mechanisms of, microRNAs (miRs) expressional profiles were analyzed by microarray technology. Further bioinformatic analysis of binding sites revealed miR-551b-5p directly targeted the brain-derived neurotrophic factor (BDNF), which was confirmed by luciferase reporter and qRT-PCR. Moreover, the level phosphorylated-TrkB, the downstream of BDNF, was elevated accompanied by above-mentioned changes of long-term iTBS. Taken together, experimental data reveals a direct link between miR-551b-5p and BDNF-mediated signaling cascade in early convalescence of stroke. Our findings provide new insights into the molecular mechanisms underlying curative effects of iTBS on stroke, thus aiding in the prognosis and personalized therapies.
As a serine/threonine phosphatase, protein phosphatase 2A (PP2A) is essential in numerous physiological processes. By generating a catalytic subunit of PP2A (Ppp2ca) conditional knockout (CKO) in C57BL/6 J mice, we explored the possible mechanisms of azoospermia by focusing on meiosis initiation and spermatogenesis. The deficiency of Ppp2ca in germ cells conspicuously disturbed spermatogonial differentiation and led to pachynema arrest, accompanied by significant apoptosis in germ cells and defects in programmed double-strand break (DSB) repair. While the formation of XY body was normal, respectively. Ppp2ca-deficient spermatocytes exhibited an abnormal cohesion complex degradation of chromosome, probably contributing to cell death. Furthermore, transcriptomics analysis was conducted to prove several genes involved in spermatogenesis and exhibited transcriptional dysregulations in Ppp2ca-deficient testes. Our study demonstrates the irreplaceable role of PP2A in spermatogenesis and provides more evidences of azoospermia etiology.
AbstractIntroductionThe repetitive transcranial magnetic stimulation (rTMS) has clinically wide application prospect of psychiatry and neuroscience, for its painless, noninvasive, and high efficiency. So far, rTMS has been used in the treatment of Alzheimer's disease (AD) but the underlying mechanism is not clear.Methods and ResultsThe APP/PS1 mice at 3‐month‐old were treated by 5 Hz high‐frequency (HF) rTMS for two weeks. After rTMS treatment, the AD‐like cognitive impairments of APP/PS1 mice were investigated subsequently, and molecular mechanisms underlying was further explored. The study showed that the 2‐week rTMS at 5Hz frequency improved cognitive impairments and AD‐like pathology (including a decrease in p‐Tau, APP, Aβ, and PP2A expression) of APP/PS1 mice. Although BDNF‐TrkB signaling was significantly enhanced, no differences of SYN, PSD95 and p‐AKT were observed in the brain of APP/PS1 mice. On the contrary, the LC3Ⅱ/LC3Ⅰ ratio was elevated with a significant reduction of ApoE and p62 in mice.ConclusionsrTMS exerts a potentially protective role in the prevention and treatment of AD by reducing ApoE expression and promoting autophagic flux, which provides a new insight into the mechanism of rTMS.
Epilepsy is a chronic brain disease affecting millions of individuals. Kainate receptors, especially kainate-type of ionotropic glutamate receptor 2 (GluK2), play an important role in epileptogenesis. Recent data showed that GluK2 could undergo post-translational modifications in terms of S-nitrosylation (SNO), and affect the signaling pathway of cell death in cerebral ischemia-reperfusion. However, it is unclear whether S-nitrosylation of GluK2 (SNO-GluK2) contributes to cell death induced by epilepsy. Here, we report that kainic acid-induced SNO-GluK2 is mediated by GluK2 itself, regulated by neuronal nitric oxide synthase (nNOS) and the level of cytoplasmic calcium in vivo and in vitro hippocampus neurons. The whole-cell patch clamp recordings showed the influence of SNO-GluK2 on ion channel characterization of GluK2-Kainate receptors. Moreover, immunohistochemistry staining results showed that inhibition of SNO-GluK2 by blocking nNOS or GluK2 or by reducing the level of cytoplasmic calcium-protected hippocampal neurons from kainic acid-induced injury. Finally, immunoprecipitation and western blotting data revealed the involvement of assembly of a GluK2-PSD95-nNOS signaling complex in epilepsy. Taken together, our results showed that the SNO-GluK2 plays an important role in neuronal injury of epileptic rats by forming GluK2-PSD95-nNOS signaling module in a cytoplasmic calcium-dependent way, suggesting a potential therapeutic target site for epilepsy.
BACKGROUND:Some esophageal cancer patients complicated with depression exhibit cognitive impairments. Frontal electroencephalogram (EEG) may be used as a reliable biomarker for prefrontal-mediated cognitive functions. This study was to investigate alterations of EEG and frontal cognitive impairment in esophageal cancer patients complicated with depression and to assess their correlation.METHODS:Sixty-five esophageal cancer patients with depression (study group) and 62 healthy controls (control group) were included in this study. The study group were assigned into psychotic depressed (PD, n = 32) and nonpsychotic depressed (NPD, n = 33) subgroups based on complication with psychotic symptoms (Brief Psychiatric Rating Scale [BPRS] >35). EEG examination, Beck self-rating depression scale, and BPRS were used to assess clinical symptoms. Chi-square test, two independent sample t-test, one-way analysis of variance, and Kruskal-Wallis test were utilized to compare the variables between two groups. EEG abnormalities and scores of frontal cognitive function test were analyzed by partial correlation analysis in the PD and NPD subgroups.RESULTS:Compared with control group, the study group displayed greater scores either in the Stroop test (19.89 ± 2.05 vs. 24.12 ± 2.19, P = 0.006) or Color Trails Test (CTT; 11.92 ± 1.01 vs. 15.02 ± 1.63, P = 0.008), and reduced score (35.05 ± 2.01 vs. 32.11 ± 2.38, P = 0.007) in the verbal fluency test (VFT). Compared to NPD subgroup, PD subgroup exhibited increased scores in Stroop test (22.89 ± 2.07 vs. 25.38 ± 2.32, P = 0.009) and CTT (13.16 ± 1.71 vs. 15.82 ± 1.13, P = 0.008). Moreover, increased scores in Stroop test and CTT as well as scores in VFT were associated with the severity of depression. The study group had an abnormal frontal EEG, such as α forward, α asymmetry, α moderation, and increased θ activity relative to control group. Similarly, compared with NPD subgroup, PD subgroup displayed α forward, α asymmetry, and α moderation. The correlation test revealed that α forward and α asymmetry were negatively associated with VFT score, but positively correlated with the scores of CTT and the Stroop test in PD subgroup. In addition, α asymmetry in NPD subgroup was positively related to CTT scores.CONCLUSION:This study indicated that frontal cognitive impairment in esophageal cancer patients complicated with depression is associated with EEG alterations.
Memory loss is the most prominent symptoms of brain aging, but there is currently no evidence-based treatment strategy. Acupuncture has been widely used in China and the effectiveness for improving learning and memory has been mentioned in previous studies. We conducted this systematic review and meta-analysis to evaluate the effectiveness of acupuncture for improving learning and memory in animal experiments.
Objectives. Our previous study has used RNA-seq technology to show that apoptotic molecules were involved in the myocardial protection of electroacupuncture pretreatment (EAP) on the ischemia/reperfusion (I/R) animal model. Therefore, this study was designed to investigate how EAP protects myocardium against myocardial I/R injury through antiapoptotic mechanism. Methods. By using rats with myocardial I/R, we ligated the left anterior descending artery (LAD) for 30 minutes followed by 4 hr of reperfusion after EAP at the Neiguan (PC6) acupoint for 12 days; we employed arrhythmia scores, serum myocardial enzymes, and cardiac troponin T (cTnT) to evaluate the cardioprotective effect. Heart tissues were harvested for western blot analyses for the expressions of pro-and antiapoptotic signaling molecules. Results. Our preliminary findings showed that EAP increased the survival of the animals along with declined arrhythmia scores and decreased CK, LDH, CK-Mb, and cTnT levels. Further analyses with the heart tissues detected reduced myocardial fiber damage, decreased number of apoptotic cells and the protein expressions of Cyt c and cleaved caspase 3, and the elevated level of Endo G and AIF after EAP intervention. At the same time, the protein expressions of antiapoptotic molecules, including Xiap, BclxL, and Bcl2, were obviously increased. Conclusions. The present study suggested that EAP protected the myocardium from I/R injury at least partially through the activation of endogenous antiapoptotic signaling.
Objective: Adenylyl cyclases (ACs) catalyze the synthesis of cAMP from ATP, and CAMP signaling affects a large number of neuronal processes. Ca2+-stimualted adenylyl cyclase 8 (AC8) expressed in the CNS plays a role in synaptic plasticity, drug addiction and ethanol sensitivity, and chronic pain. This study was to aim at examining the contributions of AC8 to epileptogenesis.Methods: In this study, we observed the seizure behavior induced by kainic acid (20 mg/kg or 30 mg/kg) or pilocarpine (350 mg/kg) in AC8 KO and wild-type mice. Next we injected kainic acid or pilocarpine to induce status epilepticus (SE), and examined neuronal degeneration (by Fluoro-Jade B staining) and mossy fiber sprouting (by Timm staining) 24 h and 2 weeks after SE termination in the hippocampus, respectively. Finally, 15 min after intraperitoneal injection of kainic acid (30 mg/kg), we examined phosphor-ERK1/2 in the hippocampus by Western blot and immunochemistry staining.Results: We first observed that AC8 KO mutants display reduced susceptibility (including seizure latency and episodes) to two chemoconvulsants, kainic acid and pilocarpine. Moreover, we found that degenerative neurons and mossy fiber sprouting induced by chemoconvulsants were significant decreased in the hippocampus. Further, Western blot and immunochemistry analysis revealed that the MAPK signaling in the hippocampus was attenuated in kainic acid-injected AC8 KO mice.Conclusion: AC8 is involved in epileptogenesis, and may serve as a potential target for the treatment of epilepsy. (C) 2015 Elsevier B.V. All rights reserved.