Are the changes in the peripheral brain-derived neurotrophic factor levels due to platelet activation?

Brain-derived neurotrophic factor(BDNF) plays an important role in central nervous system development, neurogenesis and neuronal plasticity. BDNF is also expressed in several non-neuronal tissues, and it could play an important role in other processes, such as cancer, angiogenesis, etc. Platelets are the major source of peripheral BDNF. However, platelets also contain high amounts of serotonin; they express specific surface receptors during activation, and a multitude of pro-inflammatory and immunomodulatory bioactive compounds are secreted from the granules. Until recently, there was insufficient knowledge regarding the relationship between BDNF and platelets. Recent studies showed that BDNF is present in two distinct pools in platelets, in α-granules and in the cytoplasm, and only the BDNF in the granules is secreted following stimulation, representing 30% of the total BDNF in platelets. BDNF has an important role in the pathophysiology of depression. Low levels of serum BDNF have been described in patients with major depressive disorder, and BDNF levels increased with chronic antidepressant treatment. Interestingly, there is an association between depression and platelet function. This review analyzed studies that evaluated the relationship between BDNF and platelet activation and the effect of treatments on both parameters. Only a few studies consider this possible confounding factor, and it could be very important in diseases such as depression, which show changes in both parameters.

Effects of “Nourishing Liver and Kidney” Acupuncture Therapy on Expression of Brain Derived Neurotrophic Factor and Synaptophysin after Cerebral Ischemia Reperfusion in Rats

The aim of the present study was to investigate the effect of ＂nourishing liver and kidney＂ acupuncture therapy on motor and cognitive deficits,and the underlying mechanism following cerebral ischemia-reperfusion（I/R） via increasing the expression of brain derived neurotrophic factor（BDNF） and synaptophysin（SYN） in the hippocampus.Healthy adult male SD rats were randomly divided into sham operation group（n=51）,model group（n=51）,acupuncture group（n=51） and acupuncture control group（n=51）.The middle cerebral I/R model was established.Acupunctures were performed in the acupuncture group and acupuncture control group at acupoints of Taixi（K103）,Taichong（ST09） of both sides,for 30 min once daily every morning.The animals in the sham operation group and model group were conventionally fed in the cage,without any intervention therapy.The rats of each group were assessed with modified neurological severity scores（m NSS）.The expression of BDNF and SYN in the hippocampus was detected by immunohistochemical SP method and the synaptic structure in hippocampus area was assessed morphologically and quantitatively at the 3rd,7th and 14 th day.The Morris water Maze（MWM） test was used to evaluate the rats＇ learning and memory abilities on the 15 th day after acupuncture.The animals in the acupuncture control group and sham operation group presented no neurological deficit.In the acupuncture group,the nerve functional recovery was significantly better than that in the model group at the 7th and 14 th day after modeling.The average MWM escape latency in the acupuncture group was shorter than that in the model group at the 3rd,4th and 5th day.The number of crossings of the platform quadrant in the acupuncture group was significantly more than that in the model group.At the each time point,the expression levels of BDNF and SYN in the hippocampal regions increased significantly in the model group as compared with the sham operation group and the acupuncture control group.In the acupuncture group,the expression levels of BDNF at the 7th and 14 th day increased more significantly than those in the model group.In the acupuncture group,the expression levels of SYN at the each time point increased more significantly than those in the model group.The post-synaptic density（PSD） was significantly increased and the synapse cleft width was narrowed in the acupuncture group as compared with other groups.The synaptic curvatures were improved obviously in the acupuncture group in contrast to the model group.It was concluded that the ＂nourishing liver and kidney＂ acupuncture therapy has positive effects on behavioral recovery,as well as learning and memory abilities,probably by promoting the expression of BDNF and SYN,and synaptic structure reconstruction in the ipsilateral hippocampus after I/R in rats.The ＂nourishing liver and kidney＂ acupuncture therapy can promote the functional recovery in rats after cerebral ischemia injury.

Effect of adenovirus-mediated brain derived neurotrophic factor in early retinal neuropathy of diabetes in rats

AIMTo observe effect of adenovirus-mediated brain derived neurotrophic factor in early retinal neuropathy of diabetes in rats.

Association of Increased Urine Brain Derived Neurotrophic Factor with Lower Urinary Tract Symptoms in Men with Benign Prostatic Hyperplasia

Urinary brain-derived neurotrophic factor（BDNF）, an ubiquitous neurotrophin, was found to rise in patients with benign prostatic hyperplasia（BPH）. We hypothesized that the urinary level of BDNF could be a potential biomarker for lower urinary tract symptoms（LUTS） in patients with BPH. Totally, 76 patients with BPH-caused LUTS and 32 male control subjects without BPH were enrolled. International Prostate Symptom Score（IPSS） was applied to assess the symptom severity of LUTS. Urodynamic tests were performed for the diagnosis of underlying detrusor overactivity（DO） in the patients with BPH. Urine samples were collected from all subjects. Urinary BDNF levels were measured using enzyme-linked immunosorbent assays and normalized by urinary creatinine（Cr） levels. Seventy-six BPH patients were divided into moderate LUTS group（n=51, 720） according to the IPSS. Of the 76 BPH patients, DO was present in 34（44.7%） according to the urodynamic test. The urinary BDNF/Cr levels were significantly higher in BPH patients with moderate LUTS（8.29±3.635, P〈0.0001） and severe LUTS（11.8±6.44, P〈0.0001） than normal controls（1.71±0.555）. Patients with severe LUTS tended to have higher urinary BDNF/Cr levels than patients with moderate LUTS（11.8±6.44 vs. 8.29±3.635, P=0.000）. The conditions of BPH with LUTS correlated with elevated urinary BDNF levels, and urinary BDNF levels were even higher in BPH-DO patients. The results of this study have provided evidence to suggest that urinary BDNF level test could evaluate the severity of LUTS in BPH patients, and BDNF level can be used as a biomarker

马尾综合征的病因学

马尾综合征(CES)的病因呈临床立体多元化,目前仍未完全清楚。本文综述了近年关于马尾综合征(CES)病因学的相关文献,如非新生物致CES、下腰骶椎和马尾区的肿瘤致CES、非压迫性CES等机械性压迫因素、血管性因素、神经营养因子、炎症反应等多因素分别或共同作用的结果。

BDNF在脊髓损伤和神经根损伤中的作用

综述了近年关于脑源性神经营养因子(BDNF)在脊髓损伤和神经根损伤中作用的相关文献,如脊髓损伤中BDNF表达对脊髓运动神经元的影响、BDNF在促进脊髓损伤中轴突再生的作用、BDNF在感觉功能中的作用等。

Intermittent hypoxia with or without hypercapnia is associated with tumorigenesis by decreasing the expression of brain derived neurotrophic factor and miR-34a in rats

Background Very recent studies revealed that obstructive sleep apnoea （OSA） is a contributor of the increased incidence and mortality of cancer in humans,but mechanisms of how OSA promotes tumorigenesis remains largely unknown.We investigated whether intermittent hypoxia with and without hypercapnia plays a role in tumorigenesis.Methods First,Sprague-Dawley （SD） male rats （12 weeks old） were subjected to different hypoxia exposures：intermittent hypoxia and intermittent hypoxia with hypercapnia; continuous hypoxia and normal air.The systemic application of chronic fast rate hypoxia with or without hypercapnia mimicked severe OSA patients with apnoea/hypopnea index equivalent to 60 events per hour.Then routine blood tests were performed and the levels of brain derived neurotrophic factor （BDNF） and miR-34a were examined.Results In contrast to intermittent hypoxia with hypercapnia,both intermittent hypoxia and continuous hypoxia treatments caused significantly higher levels of haematology parameters than normoxia treatments.Compared to normoxia,intermittent hypoxia with hypercapnia exposure resulted in substantial decrease of serum BDNF and,miR-34a in the lower brainstem,while less pronounced results were found in intermittent hypoxia and continuous hypoxia exposure.Conclusions The exposure of intermittent hypoxia with or without hypercapnia,mimicking the situations in severe OSA patients,was associated with,or even promoted tumorigenesis.

Clinical trial perspective for adult and juvenile Huntington's disease using genetically-engineered mesenchymal stem cells

Progress to date from our group and others indicate that using genetically-engineered mesenchymal stem cells（MSC） to secrete brain-derived neurotrophic factor（BDNF） supports our plan to submit an Investigational New Drug application to the Food and Drug Administration for the future planned Phase 1 safety and tolerability trial of MSC/BDNF in patients with Huntington＇s disease（HD）. There are also potential applications of this approach beyond HD. Our biological delivery system for BDNF sets the precedent for adult stem cell therapy in the brain and could potentially be modified for other neurodegenerative disorders such as amyotrophic lateral sclerosis（ALS）, spinocerebellar ataxia（SCA）, Alzheimer＇s disease, and some forms of Parkinson＇s disease. The MSC/BDNF product could also be considered for studies of regeneration in traumatic brain injury, spinal cord and peripheral nerve injury. This work also provides a platform for our future gene editing studies, since we will again use MSCs to deliver the needed molecules into the central nervous system.

Mechanisms of repetitive transcranial magnetic stimulation for antidepression: Evidence from preclinical studies

This review summarizes the anti-depressant mechanisms of repetitive transcranial magnetic stimulation in preclinical studies,including anti-inflammatory effects mediated by activation of nuclear factor-E2-related factor 2 signaling pathway,anti-oxidative stress effects,enhancement of synaptic plasticity and neurogenesis via activation of the endocannabinoid system and brain derived neurotrophic factor signaling pathway,increasing the content of monoamine neurotransmitters via inhibition of Sirtuin 1/monoamine oxidase A signaling pathway,and reducing the activity of the hypothalamic-pituitary-adrenocortical axis.We also discuss the shortcomings of transcranial magnetic stimulation in preclinical studies such as inaccurate positioning,shallow depth of stimulation,and difficulty in elucidating the neural circuit mechanism up-and down-stream of the stimulation target brain region.

Mechanism of Arsenic Trioxide Inhibiting Angiogenesis in Multiple Myeloma

In order to explore the molecular mechanism of arsenic trioxide treating multiple myeloma （MM） via inhibition of angiogenesis, the expression of brain derived neurotrophic factor （BDNF） and its specific receptor TrkB in human MM cell line KM3 and endothelial cell line ECV304 was detected by Western blotting. The angiogenic activity was evaluated by wound migration assay and tubule formation assay in vitro. The results showed that BDNF was detected in the MM cells and TrkB in the endothelial cells. Furthermore, 100 ng/mL BDNF could significantly induced endothelial cell tubule formation and wound migration. As2O3 depressed the expression of BDNF and TrkB in the dose- and time-dependent manner. As2O3 inhibited BDNF-induced wound migration and capillary tube formation. It was concluded that BDNF is a novel angiogenic protein as well as VEGF and has a relation with the pathogenesis of MM. As2O3 interrupts a paracrine loop between MM cells and endothelial cells by down-regulating the TrkB expression in endothelial cells and inhibiting BDNF production in MM cells, finally resulting in inhibition of MM angiogenesis. This is probably one part of the mechanisms of the As2O3 treating MM via the inhibition of angiogenesis.

Exogenous BDNF and Chondroitinase ABC Consisted Biomimetic Microenvironment Regulates Survival,Migration and Differentiation of Human Neural Progenitor Cells Transplanted into a Rat Auditory Nerve

Current putative regeneration oriented studies express possible role of stem cell based implantation strategy in the restoration of fundamental perception of hearing. The present work utilizes a rat auditory nerve (AN) directed transplantation of human neural progenitor cells (HNPCs) as a cell replacement therapy for impaired auditory function. Groups of b-bungarotoxin induced auditory function compromised female rats were used to transplant HNPCs in the nerve trunk. In the treatment groups, brain derived neurotrophic factor (BDNF), peptide amphiphile nanofiber bioactive gel (Bgel) and Chondroitinase ABC (ChABC), a digestive enzyme that cleaves the core of chondroitin sulphate proteoglycans, were added along with HNPCs while the control groups were with PA inert gel (Igel) and devoid of ChABC. Six weeks post transplantation survival, migration, and differentiation of HNPCs were studied and compared. The groups treated with BDNF and Bgel showed improved survival and differentiation of transplanted HNPCs while the ChABC treated group showed significant migration of HNPCs along the AN and elongation of neuronal fibers along the nerve towards the cochlear nucleus (CN) which was characterized by immunocytochemical markers for human Nuclei (HuN), human mitochondria (HuM) and neuronal β-tubulin (Tuj1). These findings show that addition of BDNF and ChABC consisted Bgel environment facilitated HNPC survival, migration and differentiation along the transplanted rat AN towards the CN. This transplantation strategy provides unique experimental validation for futuristic role of cell based biomaterial consisted neurotrophic factor application in clinically transferable treatment of sensorineural hearing loss (SNHL) along with cochlear implants (CI).

What is the role of Brain derived neurotrophic factor in Multiple Sclerosis neuroinflammation?

Multiple Sclerosis(MS)is a chronic,inflammatory and degenerative disease of the central nervous system(CNS)with an unknown etiology.The MS pathophysiology is due to altered bidirectional interactions between several immune cell types in the periphery(such as T and B cells,myeloid cells)and resident CNS cells(such as microglia and astrocytes).It is also known that inflammatory responses have both detrimental and neuroprotective effects.The release of brain derived neurotrophic factor(BDNF)by immune cells,in both peripheral blood and into inflammatory lesions in MS,but also by microglia and astrocytes,into the CNS,seems to be a possible mechanism for this neuroprotective effect.So far,the link between BDNF and neuroinflammation has been poorly investigated.A better understanding of this link could help in the development of new therapeutic strategies for MS.In this review,the role of BDNF in MS will be discussed as well as its possible alternative as an innovative therapeutic target.

脑源性神经生长因子与听觉中枢可塑性

脑源性神经生长因子（brain—derived neurotrophic factor，BDNF）是神经营养蛋白家族中一重要成员，它通过“活性依赖”机制对听觉中枢神经元的可塑性变化进行调节，并受中枢听觉系统神经元活性的影响。本文综述了近年来对听觉中枢可塑性变化的研究及BDNF与听觉中枢可塑的相关性及可能的调节机制。

Therapeutic effect of human amniotic epithelial cell transplantation into the lateral ventricle of hemiparkinsonian rats

Background Human amniotic epithelial cells （HAECs） are able to secrete biologically active neurotrophins such as brain-derived neurotrophic factor and neurotrophin-3, both of which exhibit trophic activities on dopamine neurons. Previous study showed that when human amniotic epithelial cells were transplanted into the striatum of 6-hydroxydopamine （6-OHDA）-induced Parkinson disease rats, the cells could survive and exert functional effects. The purpose of this study was to investigate the survival and the differentiation of human amniotic epithelial cells after being transplanted into the lateral ventricle of Parkinson＇s disease （PD） rats, and to investigate the effects of grafts on healing PD in models. Methods The Parkinson＇s model was made with stereotactic microinjection of 6-hydroxydopamine （6-OHDA） into the striatum of a rat. The PD models were divided into two groups： the HAECs group and the normal saline （NS） group. Some untreated rats were taken as the control. The rotational asymmetry induced by apomorphine of the HAECs group and the NS group were measured post cell transplantation. The expression of nestin and vimentin in grafts were determined by immunohistology. Ten weeks after transplantation the density of tyrosine hydroxylase positive cells in the substantia nigra of the HAECs group, NS group and the untreated group was determined. The differentiation of grafts was determined by TH immunohistology. High performance liquid chromatography （HPLC） was used to determine monoamine neurotransmitter levels in the striatum. Results The rotational asymmetry induced by apomorphine of the HAECs group was ameliorated significantly compared to the NS group two weeks after transplantation （P 〈0.01）. The grafts expressed nestin and vimentin five weeks after transplantation. TH immunohistochemistry indicated that the TH positive cells in the substantia nigra of the HAECs group increased significantly compared to the NS group （P 〈0.01）. Tyrosine hydroxylase （TH） positive cells in the substantia nigra of the HAEC group and the NS group were decreased compared to the untreated group （P 〈0.01）. Dopamine and DOPAC levels in the striatum of the HAECs group increased significantly compared to the NS group （P 〈0.05）. Homovanillic acid （HVA） levels in the striatum of the HAECs group increased significantly compared to the NS group （P 〈0.01）. In addition dopamine, DOPAC, and HVA levels in the striatum and dopamine levels in the cerebrospinal fluid of the HAECs group and the NS group were decreased compared to the untreated group （P 〈0.05）. Conclusions Human amniotic epithelial cells could be used to ameliorate the rotational asymmetry induced by apomorphine of the PD models. This could have been due to the increased content of dopamine and its metabolic products, DOPAC and HVA, in the striatum in the PD models.

The role of neuroinflammation in juvenile bipolar disorder

A pathophysiological relationship has been reported between inflammatory processes,decreased levels of neurotrophins,increased oxidative stress and psychiatric disorders in both juvenile and adult ages.Moreover,this relationship remains unclear in juvenile bipolar disorder(BD).We performed a systematic literature review of studies reporting measurements of inflammatory markers,oxidative stress markers or neurotrophins in juvenile and young adult subjects with BD.Concordant findings showed that inflammatory markers are increased since the earlier stages of BD.A positive correlation between decreased levels of a peripheral brain-derived neurotrophic factor and juvenile BD is controversial suggesting that those changes might occur only during the late stage of BD.No changes in central glutathione levels were reported in young adult age BD indicating that oxidative stress may be an outcome of long illness duration and repeated affective episodes.In conclusion,preliminary findings indicate that a certain relationship exists between inflammatory process and juvenile BD but evidence are insufficient to support a causal relationship.Adequately powered and prospective studies are warranted to clarify the role of inflammation,neurotrophins and oxidative stress in juvenile BD.