Neurotrophic Factor Protein Levels Research Articles

Effect of imipramine on memory, adult neurogenesis, neuroinflammation, and mitochondrial biogenesis in a rat model of alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline and memory loss. Imipramine, a tricyclic antidepressant, has potent anti-inflammatory and antioxidant properties in the central nervous system. The aim of this study was to investigate the neuroprotective effects of imipramine on streptozotocin (STZ)-induced memory impairment. Male Wistar rats received an intracerebroventricular injection of STZ (3 mg/kg, 3 μl/ventricle) using the stereotaxic apparatus. The Morris water maze and passive avoidance tests were used to evaluate cognitive functions. 24 h after the STZ injection, imipramine was administered intraperitoneally at doses of 10 or 20 mg/kg for 14 consecutive days. The mRNA and protein levels of neurotrophic factors (BDNF and GDNF) and pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) were measured in the hippocampus using real-time PCR and ELISA techniques, respectively. In addition, real-time PCR was used to evaluate the mRNA levels of markers associated with neurogenesis (Nestin, DCX, and Ki67) and mitochondrial biogenesis (PGC-1α, NRF-1, and TFAM). The results showed that imipramine, especially at a dose of 20 mg/kg, effectively improved STZ-induced memory impairment. This improvement was associated with an increase in neurogenesis and neurotrophic factors and a decrease in neuroinflammation and mitochondrial biogenesis dysfunction. Based on these results, imipramine appears to be a promising therapeutic option for improving cognitive functions in neurodegenerative diseases such as AD.

Total Saponins of Panax Notoginseng Modulate the Astrocyte Inflammatory Signaling Pathway and Attenuate Inflammatory Injury Induced by Oxygen- Glucose Deprivation/Reperfusion Injury in Rat Brain Microvascular Endothelial Cells.

Reperfusion after cerebral ischemia causes brain injury. Total saponins of Panax notoginseng (PNS) have potential roles in protecting against cerebral ischemia-reperfusion injury. However, whether PNS regulates astrocytes on oxygen-glucose deprivation/reperfusion (OGD/R) injury in rat brain microvascular endothelial cells (BMECs) and its mechanism still need further clarification. Rat C6 glial cells were treated with PNS at different doses. Cell models were established by exposing C6 glial cells and BMECs to OGD/R. Cell viability was assessed, and levels of nitrite concentration, inflammatory factors (iNOS, IL-1β, IL-6, IL-8, TNF-α), and oxidative stress-related factors (MDA, SOD, GSH-Px, T-AOC) were subsequently measured through CCK8, Grice analysis, Western blot, and ELISA, respectively. The co-cultured C6 and endothelial cells were treated with PNS for 24 hours before model establishment. Then transendothelial electrical resistance (TEER), lactate dehydrogenase (LDH) activity, brain-derived neurotrophic factor (BDNF) content, and mRNA and protein levels and positive rates of tight junction proteins [Claudin-5, Occludin, ZO-1] were measured by a cell resistance meter, corresponding kits, ELISA, RT-qPCR, Western blot, and immunohistochemistry, respectively. PNS had no cytotoxicity. PNS reduced iNOS, IL-1β, IL-6, IL-8, and TNF-α levels in astrocytes, promoted T-AOC level and SOD and GSH-Px activities, and inhibited MDA levels, thus inhibiting oxidative stress in astrocytes. In addition, PNS alleviated OGD/R injury, reduced Na-Flu permeability, and enhanced TEER, LDH activity, BDNF content, and levels of tight junction proteins Claudin-5, Occludin, ZO-1 in the culture system of astrocytes and rat BMECs after OGD/R. PNS repressed astrocyte inflammation and attenuated OGD/R injury in rat BMECs.

Nicorandil attenuates cognitive impairment after traumatic brain injury via inhibiting oxidative stress and inflammation: Involvement of BDNF and NGF.

Cognitive impairment is a prevalent adverse consequence of traumatic brain injury (TBI). The neuroprotective effects of nicorandil (N-(2-hydroxyethyl)-nicotinamide nitrate) has been previously documented, yet its protective effects against cognitive dysfunction post-TBI remain unclear. Hence, the present study was aimed to evaluate whethernicorandil attenuates cognitive dysfunction in TBI rats and the underlying mechanism behind this process. The TBI model was established with a controlled cortical impact (CCI). The effects of nicorandil on cognitive dysfunction of rats with TBI were examined through Novel object recognition (NOR) test, Y-maze test, and Morris water maze (MWM) task. After behavioral tests, hippocampal tissue was collected for Quantitative real-time PCR, Western blot analysis, and Enzyme-linked immunosorbent assay (ELISA) assay. We observed that nicorandil administration effectively ameliorates learning and memory impairment in TBI rats.Alongside, nicorandil treatment attenuated oxidative stress in the hippocampus of TBI rats, characterized by the decreased reactive oxygen species generation, malondialdehyde, and protein carbonyls levels, and concurrent promotion of antioxidant-related factors (including superoxide dismutase, glutathione peroxidase, and catalase) activities. Additionally, nicorandil treatment attenuated the inflammatory response in the hippocampus of TBI rat, as evidenced by the upregulated levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), as well as the downregulated level of IL-10. Mechanistically, nicorandil treatment significantly enhanced the mRNA and protein levels of neurotrophic factors, brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampus of TBI rats. These findings suggest that nicorandil mitigates cognitive impairment after TBI by suppressing oxidative stress and inflammation, potentially through enhancing BDNF and NGF levels.

Brain-derived neurotrophic factor (BDNF) levels in panic disorder: A systematic review and meta-analysis.

The existing literature on the association between brain-derived neurotrophic factor (BDNF) protein levels and panic disorder presents inconsistent findings. This systematic review and meta-analysis aim to synthesize the available evidence and determine the overall effect of BDNF protein levels in individuals diagnosed with panic disorder. A comprehensive literature search was conducted using electronic databases (PubMed, Embase, Scopus, PsycINFO, and Web of Science) from inception to April 21, 2023. The search strategy included relevant keywords and medical subject headings terms related to BDNF, panic disorder, and protein levels. A random-effects model was used for the meta-analysis, and subgroup analyses were performed to explore heterogeneity. Publication bias was assessed using funnel plots and statistical tests. A total of 12 studies met the inclusion criteria. The meta-analysis demonstrated a significant decrease in BDNF protein levels in individuals with panic disorder (SMD=-.53, 95% CI: -1.02 to -.04, p<.001; I2 : 92%). The results of subgroup and meta-regression analyses were not statistically significant. No significant publication bias was observed based on the results of Egger's regression test (p-value=.3550). This systematic review and meta-analysis provide evidence of lower BDNF protein levels in individuals diagnosed with panic disorder compared to healthy controls. The findings suggest a potential role for BDNF dysregulation in the pathophysiology of panic disorder. Further research is warranted to elucidate the underlying mechanisms and potential therapeutic implications.

β-glucan, a specific immuno-stimulant, produces rapid antidepressant effects by stimulating ERK1/2-dependent synthesis of BDNF in the hippocampus

A decline in microglia in the dentate gyrus of the hippocampus has recently been described as an important mechanism for the progression of depression. Reversal of this decline by innate immune system stimulants may represent a novel strategy to ameliorate the depressive phenotype in chronically stressed animals. β-glucan is a polysaccharide from Saccharomyces cerevisiae. It can efficiently stimulate microglia without inducing the production of pro-inflammatory cytokines. Therefore, β-glucan could be an ideal drug to ameliorate depressive phenotypes. In the present study, we found that a single injection of β-glucan reversed depression-like behaviors in mice induced by chronic unpredictable stress (CUS) in a dose-dependent manner, which was accompanied by a reversal of the CUS-induced decrease in brain-derived neurotrophic factor (BDNF) protein levels in the dentate gyrus. The crucial role of BDNF signaling in the antidepressant effect of β-glucan was demonstrated by experiments showing that infusion of an anti-BDNF antibody into dentate gyrus, construction of BDNF-Val68Met allele knock-in mice, or treatment with the BDNF receptor antagonist K252a abolished the antidepressant effect of β-glucan. The increased BDNF signaling induced by β-glucan was mediated by extracellular signal-regulated kinase1/2 (ERK1/2)-mediated BDNF synthesis, and inhibition of ERK1/2 by SL327 was able to abolish the antidepressant effect of β-glucan. Moreover, inhibition or depletion of microglia by minocycline or PLX3397 abolished the reversal effect of β-glucan on CUS-induced depression-like behaviors and CUS-induced impairment of ERK1/2-BDNF signaling. These results suggest that β-glucan exhibits antidepressant effects by stimulating microglia-mediated activation of ERK1/2 and synthesis of BDNF in the hippocampus.

Supplementation with Vitamin D3 Protects against Mitochondrial Dysfunction and Loss of BDNF-Mediated Akt Activity in the Hippocampus during Long-Term Dexamethasone Treatment in Rats.

Dexamethasone (DEXA) is a commonly used steroid drug with immunosuppressive and analgesic properties. Unfortunately, long-term exposure to DEXA severely impairs brain function. This study aimed to investigate the effects of vitamin D3 supplementation during chronic DEXA treatment on neurogenesis, mitochondrial energy metabolism, protein levels involved in the BDNF-mediated Akt activity, and specific receptors in the hippocampus. We found reduced serum concentrations of 25-hydroxyvitamin D3 (25(OH)D3), downregulated proBDNF and pAkt, dysregulated glucocorticosteroid and mineralocorticoid receptors, impaired mitochondrial biogenesis, and dysfunctional mitochondria energy metabolism in the DEXA-treated group. In contrast, supplementation with vitamin D3 restored the 25(OH)D3 concentration to a value close to that of the control group. There was an elevation in neurotrophic factor protein level, along with augmented activity of pAkt and increased citrate synthase activity in the hippocampus after vitamin D3 administration in long-term DEXA-treated rats. Our findings demonstrate that vitamin D3 supplementation plays a protective role in the hippocampus and partially mitigates the deleterious effects of long-term DEXA administration. The association between serum 25(OH)D3 concentration and BDNF level in the hippocampus indicates the importance of applying vitamin D3 supplementation to prevent and treat pathological conditions.

Rosmarinic Acid Improves Cognitive Abilities and Glucose Metabolism in Aged C57Bl/6N Mice While Disrupting Lipid Profile in Young Adults in a Sex-Dependent Fashion.

A growing body of evidence suggests that regular consumption of natural products might promote healthy aging; however, their mechanisms of action are still unclear. Rosmarinic acid (RA) is a polyphenol holding anti-inflammatory, antioxidant and neuroprotective properties. The aim of this study was to characterise the efficacy of an oral administration of RA in promoting healthspan in a mouse model of physiological aging. Aged C57Bl/6 male and female (24-month-old) mice were either administered with RA (500 mg/Kg) or a vehicle in drinking bottles for 52 days while 3-month-old mice receiving the same treatment were used as controls. All subjects were assessed for cognitive abilities in the Morris water maze (MWM) and for emotionality in the elevated-plus maze test (EPM). Brain-derived Neurotrophic Factor (BDNF) protein levels were evaluated in the hippocampus. Since the interaction between metabolic signals and cerebral functions plays a pivotal role in the etiopathogenesis of cognitive decline, the glycaemic and lipid profiles of the mice were also assessed. RA enhanced learning and memory in 24-month-old mice, an effect that was associated to improved glucose homeostasis. By contrast, the lipid profile was disrupted in young adults. This effect was associated with worse glycaemic control in males and with reduced BDNF levels in females, suggesting powerful sex-dependent effects and raising a note of caution for RA administration in young healthy adult subjects.

Aripiprazole combined with nerve growth factor improves cognitive function in mice with schizophrenia model

The pathogenesis and treatment of cognitive dysfunction in patients with schizophrenia (SCZ) remains a challenge. Exploring new effective treatment strategies is relevant for the improvement of cognitive function. Aripiprazole (ARI) is an atypical antipsychotic that improves some cognitive functions. Nerve growth factor (NGF) has been shown to improve cognitive function in certain neurological impairments and partial neurological deficits, but its mechanism of action in cognitive dysfunction in SCZ is unclear. In this study, we established schizophrenia mouse model with dizocilpine (MK-801); treated mice with ARI alone or in combination with NGF; assessed spontaneous activity and cognitive function using open field test and Morris water maze test; and measured brain-derived neurotrophic factor (BDNF) protein and mRNA expression levels using immunohistochemistry and molecular biology assays. The results showed that ARI alone or in combination with NGF can improve increased spontaneous activity and spatial learning memory deficits in model mice by elevating BDNF expression levels in prefrontal cortex (PFC) and hippocampus (HIP). The results suggest that ARI combined with NGF can improve cognitive function in SCZ, which provides new ideas and directions for the clinical treatment of cognitive dysfunction in SCZ.

The Association between Brain-Derived Neurotrophic Factor (BDNF) Protein Level and Body Mass Index.

Background and Objectives: Obesity is a major health concern worldwide. Many studies emphasize the important role of brain-derived neurotrophic factor (BDNF) in regulating appetite and body weight. We aimed to investigate the association between BDNF protein serum levels and body mass index (BMI). Materials and Methods: We conducted a cross-sectional study among 108 healthy adult participants divided into six categories depending on their body mass index (BMI). The ages of the participants ranged between 21 to 45 years. The BDNF serum level was measured using the enzyme-linked immunosorbent assay (ELISA) technique. Results: A Kruskal-Wallis test showed a significant difference in BDNF between the different BMI categories, χ2(2) = 24.201, p &lt; 0.001. Our data also showed that BDNF levels were significantly lower in people with obesity classes II and III than those of normal weight (p &lt; 0.05). The Spearman rank correlation test was statistically significant with negative correlations between the BMI and BDNF (r) = -0.478, (p &lt; 0.01). Moreover, we observed a negative dose-dependent relationship pattern between BMI categories and the levels of circulating BDNF protein. Conclusions: In this study, our data support the hypothesis that low serum levels of BDNF are associated with high BMI and obesity in Saudi adults.

NLX-101, a 5-HT1A receptor-biased agonist, improves pattern separation and stimulates neuroplasticity in aged rats

5-HT1A serotonin receptors may play a role in cognitive function changes related to advanced age. Here, we investigated the effects of acute and repeated treatment with NLX-101 (F15599), a postsynaptic 5-HT1A receptor-biased agonist, and F13714, a presynaptic 5-HT1A receptor-biased agonist on spatial object pattern separation (OPS) in aged (22–24 months) rats. Neuroplasticity markers including brain-derived neurotrophic factor, PSD95, synaptophysin, and doublecortin were evaluated in the hippocampus. Unlike younger rats, aged rats were incapable of discriminating any new position of the objects in the arena, reflecting the detrimental effect of aging on pattern separation. However, aged animals treated with NLX-101 showed a significant cognitive improvement in the OPS test, accompanied by increases in hippocampal brain-derived neurotrophic factor and PSD95 protein levels. In contrast, no improvement in OPS performance was observed when aged rats received F13714. Both F13714 and NLX-101 increased the number of newborn neurons in the hippocampi of aged rats. These findings provide a rationale for targeting post-synaptic 5-HT1A as a treatment for cognitive deficits related to aging.

Mild acute stress prevents the memory impairment induced by long-term isoflurane anesthesia.

Long-term isoflurane anesthesia exposure could result in postoperative cognitive dysfunction (POCD). Preoperative stress is also reported to be a risk factor of POCD. However, it is unknown whether acute stress could impair memory after long-term isoflurane anesthesia. In this study, we categorized the mice with acute stress into mild (30 min restraint stress), moderate (60 min restraint stress), and severe (120 min restraint stress) stress groups and then we used Open-Field Test (OFT) to detect whether different scales of acute restraint stress successfully induced acute stress in mice. The memory performance of mice was measured using contextual and cued memory test, and the brain-derived neurotrophic factor protein levels of hippocampus was detected by Western blot. We verified that mild stress has pro-cognitive effect, but severe stress has amnestic effect. Moreover, we found that mild and moderate other than severe acute stress could partially attenuate the memory impairment induced by long-term isoflurane anesthesia. Mild and moderate acute stress could partially attenuate the memory impairment induced by long-term isoflurane anesthesia.

Effects of Subchronic Aluminum Exposure on Learning, Memory, and Neurotrophic Factors in Rats.

Aluminum (Al) is a neurotoxin that gradually accumulates in the brain in human life, resulting in oxidative brain injury related to Alzheimer's disease (AD) and other diseases. In this study, the learning and memory of rats exposed to different aluminum concentrations (0.0 g/L, 2.0 g/L, 4.0 g/L, and 8.0 g/L) were studied, and the learning and memory of rats were observed by shuttle box experiment. With hematoxylin and eosin staining, Western blot, immunofluorescence, and RT-PCR, the morphology of nerve cells in the hippocampus of rat brain were observed, and the levels of activator protein-1 (AP-1) gene and protein, nerve growth factor (NGF), neurotrophin-3 (NT3), glial cell line-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF) gene and protein level, etc. The experimental results showed that subchronic aluminum exposure damaged learning and memory in rats. The cognitive function damage in rats was more evident after increasing the aluminum intake dose. The more aluminum intake, the more pronounced the histological changes in the hippocampus will be. The expression level and protein content of neurotrophic factors in the hippocampus of rats showed a negative correlation with aluminum intake. In this experiment, we explored the mechanism of aluminum exposure in learning and memory disorders, and provided some data reference for further elucidation of the damage mechanism of aluminum on the nervous system and subsequent preventive measures.

Psychophysiological and Metabolomics Responses of Adults during Horticultural Activities Using Soil Inoculated with Streptomyces rimosus: A Pilot Study.

This study compared the physiological effects at a metabolomics level with autonomic nervous system responses in adults during soil mixing activities, based on the presence or absence of Streptomyces rimosus in the soil. Thirty adult participants performed soil mixing activities for 5 min using sterilized soil with culture media and Streptomyces rimosus, respectively. Blood samples were drawn twice from each participant after each activity. Electroencephalograms were measured during the activity. Serum metabolites underwent metabolite profiling by gas chromatography, followed by multivariate analyses. Serum brain-derived neurotrophic factor and C-reactive protein levels were measured by Enzyme-Linked Immunosorbent Assay. Soil-emitted volatile organic compounds were identified via solid-phase microextraction and gas chromatography–mass spectroscopy, followed by multivariate analyses. The volatile compound analysis revealed that the terpenoid and benzoid compounds, geosmin, and 2-methylisoborneol were greater in soil with Streptomyces rimosus. Serum metabolomics revealed that the treatment group (soil inoculated with Streptomyces rimosus) possessed relatively higher levels of serotonin compared to the control group (soil mixed with culture media), and serum C-reactive protein levels were significantly lower in the treatment group. In the treatment group, the electroencephalogram revealed that alpha band activity of the occipital lobe increased. This study concludes that Streptomyces rimosus soil contact can positively affect human metabolic and autonomic reactions. Therefore, this pilot study confirmed the possible role of soil microorganisms in horticultural activities for psychophysiological effects in humans.

Effect of time restricted feeding on anthropometric measures, eating behavior, stress, and brain-derived neurotrophic factor (BDNF) and lipopolysaccharide-binding protein (LBP) levels in women with overweight/obesity and food addiction: a study protocol for a randomized clinical trial

BackgroundFood addiction is one of the behavioral factors that play an important role in the pathogenesis of obesity. Much evidence is available suggesting intestinal microbiomes can play a role in eating behavior, body composition, and BDNF levels, and they can be modified by time-restricted feeding (TRF). So, this study will aim to evaluate the effect of TRF on anthropometric measures, eating behavior, stress, and serum BDNF and LBP levels in women with overweight/obesity and food addiction.MethodsWe will carry out a randomized clinical trial for 8 weeks to evaluate the effect of a TRF on anthropometric measures, eating behavior, stress level, serum BDNF and LBP levels in women with overweight/obesity and food addiction.DiscussionGiven the effect of BDNF on regulating eating behavior and body weight and the effect of dietary restrictions on BDNF and the gut microbiome, the TRF diet could possibly be a new way to successfully manage weight through modifying BDNF in people with eating disorders, including food addiction.Trial registrationIranian Registry of Clinical Trials IRCT20131228015968N7. Registered on 25 October 2020.

Abstract TP17: Activation Of Erk1/2 Signaling Drives Cardiac Hypertrophy During Chronic Mild Stress-induced Depression In Mice

Background: Major depressive disorder (MDD) is one of the fastest-growing disability disorders in the US and worldwide. Extensive clinical data suggest that MDD is associated with an increased risk of hypertension, coronary heart disease, and other cardiovascular diseases. A close relation between cardiovascular and cerebrovascular diseases and clinical evidence presents a potential link between depression and stroke. MDD when combined with other comorbidities, makes the prognosis worse. Dysregulation of the sympathetic nervous system, impaired hypothalamic-pituitary-adrenal axis, and increased inflammatory response are plausible mechanisms that have been linked to depression-induced cardio- and cerebrovascular complications. In the current study, we investigated cardiac structural and functional alterations in a mouse model of chronic mild stress (CMS) exhibiting depression-like behavior. Methods and Results: The mice were divided into control (CT) and CMS groups. The CMS mice were subjected to various mild, unpredictable stressors for 7 weeks. Depression-like traits were confirmed in the CMS group by analyses of behavioral changes using open field and forced swim tests and a decrease in hippocampal brain-derived neurotrophic factor (BDNF) protein level. To evaluate depression-associated neuronal damage and neuronal plasticity, Fluoro-Jade C staining and expression of microtubule-associated protein 2 were examined. However, we did not observe neuronal damage in the CMS mice as compared to the CT mice. We also observed a decrease in cardiac BDNF expression and upregulation of IL-6 in the CMS mice compared to the CT group. Echocardiographic and histological analyses showed an increase in ventricular wall thickness with increased cardiomyocyte size in the CMS group. However, we did not find changes in fetal gene expression or fibrosis markers. Investigation of underlying mechanisms showed a significant upregulation in ERK1/2 signaling in the left ventricles of the CMS mice as compared to the control group, with no changes in phospho-p38, NFATc3, or JNK levels. Conclusion: In conclusion, these data suggest that ERK1/2 signaling might have an important role in cardiac hypertrophic response during the CMS-induced depression in mice.

Comparison of the Effects of Cuprizone on Demyelination in the Corpus Callosum and Hippocampal Progenitors in Young Adult and Aged Mice.

Cuprizone is commonly used to induce neuronal demyelination in mice. In the present study, we compared the cuprizone-induced demyelination in the corpus callosum and investigated the effects of cuprizone on proliferating cells and neuroblasts in the dentate gyrus of young adult and aged mice. 5-week- and 23-month-old mice were fed a normal diet or a 0.2% cuprizone-enriched diet for 5weeks. Mice fed a cuprizone-supplemented diet showed a significant reduction in myelin basic protein-positive structures in the corpus callosum, with the reduction in myelinated fibers being confirmed by electron microscopic analysis. In addition, we observed a marked increase in Ki67-positive proliferating cells and doublecortin-immunoreactive neuroblasts in young adult mice in response to cuprizone treatment, although not in aged mice, as the basal levels of these cells were significantly lower in these older mice. Furthermore, Ser133-phosphorylated cAMP response element-binding protein (pCREB)-positive nuclei and brain-derived neurotrophic factor (BDNF) protein levels were significantly reduced in young adult mice following cuprizone treatment in young adult, although again not in the aged mice. However, in both young adult and aged mice, there were no significant reductions in hippocampal mature neurons in response to cuprizone treatment. These observations indicate that in the mice of both age groups a cuprizone-supplemented diet contributes to an increase in demyelination in the corpus callosum and neural progenitor cells in the dentate gyrus, although the damage is more pronounced in young adult mice. This demyelination and reduction in neural progenitor cells may be associated with changes in the levels of BDNF and pCREB in the dentate gyrus.

Effect of combination therapy with neural stem cell transplantation and teramethylpyrazine in rats following acute spinal cord injury.

This study was to explore the effects of teramethylpyrazine (TMP) administered in conjunction with neural stem cell transplantation on motor function, pathological lesions and the Janus kinase (JAK)2/signal transducer and activator of transcription 3 signal transduction pathway in rats following acute spinal cord injury (SCI). Female Sprague-Dawley rats were randomly divided into sham, model, neural stem cells (NSCs) and NSCs+TMP groups. Motor function was evaluated using the Basso, Beattie, Bresnahan scale. Spinal cord neuropathies and neuron apoptosis were observed by HE and TUNEL staining. The brain-derived neurotrophic factor (BDNF), Nogo-A, JAK2 and p-JAK2 protein levels were measured by western blot analysis. NSCs+TMP significantly improved rat motor function, attenuated impaired spinal cords, and decreased cellular apoptosis, compared with NSCs therapy alone (P < 0.05). In addition, expression of BDNF protein was significantly higher in NSCs+TMP rats compared with other groups regardless of time postinjury (P < 0.05). The highest expression levels of Nogo-A protein were observed in the model group. The expression of p-JAK2 in the NSCs+TMP group was relatively lower than the model and NSCs groups (P < 0.05). In rats with SCI, NSCs+TMP effectively improved motor function and offered spinal cord protection by increasing BDNF and decreasing Nogo-A levels, as well as inhibiting the JAK2/STAT3 signal transduction pathway, suggesting that TMP could be a useful agent in NSCs transplantation in the treatment of SCI.

Estrogen augmented visceral pain and colonic neuron modulation in a double-hit model of prenatal and adult stress.

BACKGROUNDChronic stress during pregnancy may increase visceral hyperalgesia of offspring in a sex-dependent way. Combining adult stress in offspring will increase this sensitivity. Based on the evidence implicating estrogen in exacerbating visceral hypersensitivity in female rodents in preclinical models, we predicted that chronic prenatal stress (CPS) + chronic adult stress (CAS) will maximize visceral hyperalgesia; and that estrogen plays an important role in colonic hyperalgesia.AIMThe aim was to illuminate the role of estrogen in colonic hyperalgesia and its underlying mechanisms.METHODSWe established a CPS plus CAS rodent model in which the balloon was used to distend the colorectum. The single-fiber recording in vivo and patch clamp experiments in vitro were used to monitor the colonic neuron’s activity. The reverse transcription-polymerase chain reaction, western blot, and immunofluorescence were used to study the effects of CPS and CAS on colon primary afferent sensitivity. We used ovariectomy and letrozole to reduce estrogen levels of female rats respectively in order to assess the role of estrogen in female-specific enhanced primary afferent sensitization.RESULTSSpontaneous activity and single fiber activity were significantly greater in females than in males. The enhanced sensitization in female rats mainly came from low-threshold neurons. CPS significantly increased single-unit afferent fiber activity in L6-S2 dorsal roots in response. Activity was further enhanced by CAS. In addition, the excitability of colon-projecting dorsal root ganglion (DRG) neurons increased in CPS + CAS rats and was associated with a decrease in transient A-type K+ currents. Compared with ovariectomy, treatment with the aromatase inhibitor letrozole significantly reduced estrogen levels in female rats, confirming the gender difference. Moreover, mice treated with letrozole had decreased colonic DRG neuron excitability. The intrathecal infusion of estrogen increased brain-derived neurotrophic factor (BDNF) protein levels and contributed to the response to visceral pain. Western blotting showed that nerve growth factor protein was upregulated in CPS + CAS mice.CONCLUSIONThis study adds to the evidence that estrogen-dependent sensitization of primary afferent colon neurons is involved in the development of chronic stress-induced visceral hypersensitivity in female rats.

Ninjin'yoeito Alleviates Neuropathic Pain Induced by Chronic Constriction Injury in Rats.

Kampo medicines are frequently used empirically to treat pain in clinical practice. Ninjin'yoeito (NYT), which is associated with few adverse effects, is often used to treat the elderly, but has not yet been examined in detail. We herein investigated the effects of NYT, at 500 and 1,000 mg/kg p.o. (NYT500/NYT1000 group) in single and repeated administrations for 14 days, on pain in rats with peripheral neuropathy induced by loose ligation of the sciatic nerve (chronic constriction injury: CCI). Untreated CCI rats given distilled water were used as a control group. To assess induced pain, the pain threshold was measured using the von Frey test. To evaluate spontaneous pain, the ground-contact area of the paw with neuropathic pain was measured using the Dynamic Weight Bearing test. Serum samples were collected after the test to elucidate the mechanism of action of NYT, and brain-derived neurotrophic factor (BDNF) and corticosterone protein levels, which have been reported to change due to chronic pain, were analyzed. After single administration of NYT, the pain threshold rose in the NYT500 and NYT1000 groups. The pain threshold tended to rise on day 14 of repeated administration in the NYT500 group (p = 0.08) and it significantly rose at NYT1000 group (p < 0.05) compared to Control group. In addition, the foot contact area increased (p = 0.09). Therefore, CCI-induced pain was significantly remitted and spontaneous pain was remitted after repeated administration of NYT. Serum BDNF levels were higher in untreated CCI rats than in normal rats (p = 0.05), but decreased after the repeated administration of NYT (NYT1000, p = 0.15), while serum corticosterone levels were lower (p = 0.12) than those in normal rats and increased after the repeated administration of NYT (NYT1000, p = 0.07). The blood BDNF level has been suggested to influence pain intensity. The findings demonstrated NYT effectively treats neuropathic pain, suggesting that a NYT-induced decrease in blood BDNF contributed to the mechanism of pain relief. In addition, the variation of corticosterone was observed, suggesting that normalization of responsiveness to stress by NYT contributed to the pain relief.

Xuesaitong injection (lyophilized) combined with aspirin and clopidogrel protect against focal cerebral ischemic/reperfusion injury in rats by suppressing oxidative stress and inflammation and regulating the NOX2/IL-6/STAT3 pathway.

Combination of aspirin (ASA) and clopidogrel (CLP) [dual antiplatelet therapy (DAPT)] has been limited in reducing early recurrent stroke events. Xuesaitong injection (lyophilized) (XST) made of total saponins from P. notoginseng, which significantly improves cerebral circulation and has been widely used in clinical applications for decades to treat and prevent ischemic stroke. Here, we confirmed the protective effect and mechanism of XST combined with DAPT (XST+ASA+CLP) on cerebral ischemia/reperfusion injury, exploring their better pharmacological action for clinical patients. Sprague-Dawley rats (SD rats) (n=9 in each group) were randomly assigned to three groups and pretreated with XST, ASA+CLP, or XST+ASA+CLP for 7 days. Then rats were subjected to 2 h of middle cerebral artery occlusion (MCAO) followed by reperfusion for 24 h. Therapeutic effect of XST+ASA+CLP was measured by infarct volume, neurological behavior and regional cerebral blood flow (rCBF). Inhibition of neuronal apoptosis and glial cells was determined by immunofluorescent staining. We studied the protein levels of neurotrophic factors, neuroplasticity-related factors, oxidative stress indicators and inflammatory factors by ELISA assay. XST+ASA+CLP group showed significant reduction in infarct volumes and neurological deficit scores. XST+ASA+CLP group also had higher levels in rCBF and synaptic growth, and showed remarkable inhibition of microglia and astrocytes activation and the neuronal apoptosis. In addition, XST+ASA+CLP group had lower levels of NADPH, protein carbonyl, 4-hydroxynonenal (4-HNE), 8-hydroxydeoxyguanosine (8-OHdG) and several inflammatory cytokines. Moreover, XST+ASA+CLP group also had lower levels of NOX2, inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and p-STAT3/STAT3. These results demonstrate that a combination of XST, ASA, and CLP effectively protected rats against middle cerebral artery occlusion/reperfusion (MCAO/R) injury by suppressing the NOX2/IL-6/ STAT3 pathway. These novel findings provide theoretical basis and experimental evidence for the rationality of clinical combined use of drugs in the treatment of ischemic stroke.