Inflammation and apoptosis accelerate progression to irreversible atrophy in denervated intrinsic muscles of the hand compared with biceps: proteomic analysis of a rat model of obstetric brachial plexus palsy

In treating patients with obstetric brachial plexus palsy,we noticed that denervated intrinsic muscles of the hand become irreversibly atrophic at a faster than denervated biceps.In a rat model of obstetric brachial plexus palsy,denervated intrinsic musculature of the forepaw entered the irreversible atrophy far earlier than denervated biceps.In this study,isobaric tags for relative and absolute quantitation were examined in the intrinsic musculature of forepaw and biceps on denervated and normal sides at 3 and 5 weeks to identify dysregulated proteins.Enrichment of pathways mapped by those proteins was analyzed by Kyoto Encyclopedia of Genes and Genomes analysis.At 3 weeks,119 dysregulated proteins in denervated intrinsic musculature of the forepaw were mapped to nine pathways for muscle regulation,while 67 dysregulated proteins were mapped to three such pathways at 5 weeks.At 3 weeks,27 upregulated proteins were mapped to five pathways involving inflammation and apoptosis,while two upregulated proteins were mapped to one such pathway at 5 weeks.At 3 and 5 weeks,53 proteins from pathways involving regrowth and differentiation were downregulated.At 3 weeks,64 dysregulated proteins in denervated biceps were mapped to five pathways involving muscle regulation,while,five dysregulated proteins were mapped to three such pathways at 5 weeks.One protein mapped to inflammation and apoptotic pathways was upregulated from one pathway at 3 weeks,while three proteins were downregulated from two other pathways at 5 weeks.Four proteins mapped to regrowth and differentiation pathways were upregulated from three pathways at 3 weeks,while two proteins were downregulated in another pathway at 5 weeks.These results implicated inflammation and apoptosis as critical factors aggravating atrophy of denervated intrinsic muscles of the hand during obstetric brachial plexus palsy.All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Fudan University,China(approval No.DF-325)in January 2015.     

Protein synthesis modulation as a therapeutic approach for amyotrophic lateral sclerosis and frontotemporal dementia

Protein synthesis is essential for cells to perform life metabolic processes.Pathological alterations of protein content can lead to particular diseases.Cells have an intrinsic array of mechanisms and pathways that are activated when protein misfolding,accumulation,aggregation or mislocalization occur.Some of them(like the unfolded protein response)represent complex interactions between endoplasmic reticulum sensors and elongation factors that tend to increase expression of chaperone proteins and/or repress translation in order to restore protein homeostasis(also known as proteostasis).This is even more important in neurons,as they are very susceptible to harmful effects associated with protein overload and proteostatic mechanisms are less effective with age.Several neurodegenerative pathologies such as Alzheimer’s,Parkinson’s,and Huntington’s diseases,amyotrophic lateral sclerosis and frontotemporal dementia exhibit a particular molecular signature of distinct,unbalanced protein overload.In amyotrophic lateral sclerosis and frontotemporal dementia,the majority of cases present intracellular inclusions of ubiquitinated transactive response DNA-binding protein of 43 kDa(TDP-43).TDP-43 is an RNA binding protein that participates in RNA metabolism,among other functions.Dysregulation of TDP-43(e.g.aggregation and mislocalization)can dramatically affect neurons,and this has been linked to disease development.Expression of amyotrophic lateral sclerosis/frontotemporal dementia TDP-43-related mutations in cellular and animal models has been shown to recapitulate key features of the amyotrophic lateral sclerosis/frontotemporal dementia disease spectrum.These variants can be causative of degeneration onset and progression.Most neurodegenerative diseases(including amyotrophic lateral sclerosis and frontotemporal dementia)have no cure at the moment;however,modulating translation has recently emerged as an attractive approach that can be performed at several steps(i.e.regulating activation of initiation and elongation factors,inhibiting unfolded protein response activation or inducing chaperone expression and activity).This review focuses on the features of protein imbalance in neurodegenerative disorders and the relevance of developing therapeutical compounds aiming at restoring proteostasis.We strive to highlight the importance of research on drugs that,not only restore protein imbalance without compromising translational activity of cells,but are also as safe as possible for the patients.     

Role of activin receptor-like kinase 1 in vascular development and cerebrovascular diseases

Activin receptor-like kinase 1(ALK1)is a transmembrane serine/threonine receptor kinase of the transforming growth factor beta(TGFβ)receptor superfamily.ALK1 is specifically expressed in vascular endothelial cells,and its dynamic changes are closely related to the proliferation of endothelial cells,the recruitment of pericytes to blood vessels,and functional differentiation during embryonic vascular development.The pathophysiology of many cerebrovascular diseases is today understood as a disorder of endothelial cell function and an imbalance in the proportion of vascular cells.Indeed,mutations in ALK1 and its co-receptor endoglin are major genetic risk factors for vascular arteriovenous malformation.Many studies have shown that ALK1 is closely related to the development of cerebral aneurysms,arteriovenous malformations,and cerebral atherosclerosis.In this review,we describe the various roles of ALK1 in the regulation of angiogenesis and in the maintenance of cerebral vascular homeostasis,and we discuss its relationship to functional dysregulation in cerebrovascular diseases.This review should provide new perspectives for basic research on cerebrovascular diseases and offer more effective targets and strategies for clinical diagnosis,treatment,and prevention.     

Risk factors for corticosteroid insufficiency during the sub-acute phase of acute traumatic brain injury

Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency.Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury,but few studies have examined this occurrence.A multicenter,prospective,cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China,and the critical illness-related corticosteroid insufficiency incidence,critical-illness-related corticosteroid insufficiency-related risk factors,complications,and 28-day mortality among these patients was recorded.Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10μg/dL(275.9 nM)on post-injury day 4 or when serum cortisol was insufficiently suppressed(less than 50%)during a dexamethasone suppression test on post-injury day 5.The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6%of patients with mild injury,22.5%of patients with moderate injury,and 52.2%of patients with severe injury.Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury.Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions,diffuse axonal injury,brain herniation,and hypotension.Differences in the incidence of hospital-acquired pneumonia,gastrointestinal bleeding,and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.Hypotension,brain-injury severity,and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency.These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis.The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury,especially those with hypotension,hemorrhagic cerebral contusions,diffuse axonal injury,and brain herniation.Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency.This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University,China in December 2011(approval No.201189).     

Stroke gets in your eyes: stroke-induced retinal ischemia and the potential of stem cell therapy

Stroke persists as a global health and economic crisis,yet only two interventions to reduce stroke-induced brain injury exist.In the clinic,many patients who experience an ischemic stroke often further suffer from retinal ischemia,which can inhibit their ability to make a functional recovery and may diminish their overall quality of life.Despite this,no treatments for retinal ischemia have been developed.In both cases,ischemia-induced mitochondrial dysfunction initiates a cell loss cascade and inhibits endogenous brain repair.Stem cells have the ability to transfer healthy and functional mitochondria not only ischemic neurons,but also to similarly endangered retinal cells,replacing their defective mitochondria and thereby reducing cell death.In this review,we encapsulate and assess the relationship between cerebral and retinal ischemia,recent preclinical advancements made using in vitro and in vivo retinal ischemia models,the role of mitochondrial dysfunction in retinal ischemia pathology,and the therapeutic potential of stem cell-mediated mitochondrial transfer.Furthermore,we discuss the pitfalls in classic rodent functional assessments and the potential advantages of laser Doppler as a metric of stroke progression.The studies evaluated in this review highlight stem cell-derived mitochondrial transfer as a novel therapeutic approach to both retinal ischemia and stroke.Furthermore,we posit the immense correlation between cerebral and retinal ischemia as an underserved area of study,warranting exploration with the aim of these treating injuries together.     

Differences in clinical and genetic characteristics between early-and late-onset narcolepsy in a Han Chinese cohort

Early-and late-onset narcolepsy constitutes two distinct diagnostic subgroups.However,it is not clear whether symptomology and genetic risk factors differ between early-and late-onset narcoleptics.This study compared clinical data and single-nucleotide polymorphisms(SNPs)between early-and late-onset patients in a large cohort of 899 Han Chinese narcolepsy patients.Blood,cerebrospinal fluid,and clinical data were prospectively collected from patients,and patients were genotyped for 40 previously reported narcolepsy risk-conferring SNPs.Genetic risk scores(GRSs),associations of five different sets of SNPs(GRS1–GRS5)with early-and late-onset narcolepsy,were evaluated using logistic regression and receiver operating characteristic curves.Mean sleep latency was significantly shorter in early-onset cases than in late-onset cases.Symptom severity was greater among late-onset patients,with higher rates of sleep paralysis,hypnagogic hallucinations,health-related quality of life impairment,and concurrent presentation with four or more symptoms.Hypocretin levels did not differ significantly between early-and late-onset cases.Only rs3181077(CCR1/CCR3)and rs9274477(HLA-DQB1)were more prevalent among early-onset cases.Only GRS1(26 SNPs;OR=1.513,95%CI:0.893–2.585;P<0.05)and GRS5(6 SNPs;OR=1.893,95%CI:1.204–2.993;P<0.05)were associated with early-onset narcolepsy,with areas under the receiver operating characteristic curves of 0.731 and 0.732,respectively.Neither GRS1 nor GRS5 included SNPs in HLA regions.Our results indicate that symptomology and genetic risk factors differ between early-and late-onset narcolepsy.This protocol was approved by the Institutional Review Board(IRB)Panels on Medical Human Subjects at Peking University People’s Hospital,China(approval No.Yuanlunshenlinyi 86)in October 2011.     

Adipose-derived stem cells modified by BDNF gene rescue erectile dysfunction after cavernous nerve injury

Cavernous nerve injury is the main cause of erectile dysfunction following radical prostatectomy.The recovery of erectile function following radical prostatectomy remains challenging.Our previous studies found that injecting adipose-derived stem cells(ADSCs)into the cavernosa could repair the damaged cavernous nerves,but the erectile function of the treated rats could not be restored to a normal level.We evaluated the efficacy of ADSCs infected with a lentiviral vector encoding rat brain-derived neurotrophic factor(lenti-rBDNF)in a rat model of cavernous nerve injury.The rats were equally and randomly divided into four groups.In the control group,bilateral cavernous nerves were isolated but not injured.In the bilateral cavernous nerve injury group,bilateral cavernous nerves were isolated and injured with a hemostat clamp for 2 minutes.In the ADSCGFP and ADSCrBDNF groups,after injury with a hemostat clamp for 2 minutes,rats were injected with ADSCs infected with lenti-GFP(1×106 in 20μL)and lenti-rBDNF(1×106 in 20μL),respectively.Erectile function was assessed 4 weeks after injury by measuring intracavernosal pressures.Then,penile tissues were collected for histological detection and western blot assay.Results demonstrated that compared with the bilateral cavernous nerve injury group,erectile function was significantly recovered in the ADSCGFP and ADSCrBDNF groups,and to a greater degree in the ADSCrBDNF group.Neuronal nitric oxide synthase content in the dorsal nerves and the ratio of smooth muscle/collagen were significantly higher in the ADSCrBDNF and ADSCGFP groups than in the bilateral cavernous nerve injury group.Neuronal nitric oxide synthase expression was obviously higher in the ADSCrBDNF group than in the ADSCGFP group.These findings confirm that intracavernous injection with ADSCs infected with lenti-rBDNF can effectively improve erectile dysfunction caused by cavernous nerve injury.This study was approved by the Medical Animal Care and Welfare Committee of Wuhan University,China(approval No.2017-1638)on June 20,2017.     

Acupuncture promotes functional recovery after cerebral hemorrhage by upregulating neurotrophic factor expression

Acupuncture is widely used in the treatment of cerebral hemorrhage,and it improves outcomes in experimental animal models and patients.However,the mechanisms underlying the effectiveness of acupuncture treatment for cerebral hemorrhage are still unclear.In this study,a model of intracerebral hemorrhage was produced by injecting 50μL autologous blood into the caudate nucleus in Wistar rats.Acupuncture at Baihui(DU20)and Qubin(GB7)acupoints was performed at a depth of 1.0 inch,12 hours after blood injection,once every 24 hours.The needle was rotated at 200 r/min for 5 minutes,For each 30-minute session,needling at 200 r/min was performed for three sessions,each lasting 5 minutes.For the positive control group,at 6 hours,and 1,2,3 and 7 days after induction of hemorrhage,the rats were intraperitoneally injected with 1 mL aniracetam(0.75 mg/mL),three times a day.The Bederson behavioral test was used to assess palsy in the contralateral limbs.Western blot assay was used to examine the expression levels of Nestin and basic fibroblast growth factor in the basal ganglia.Immunohistochemistry was performed to count the number of Nestin-and glial cell line-derived neurotrophic factor-positive cells in the basal ganglia.Acupuncture effectively reduced hemorrhage and brain edema,elevated the expression levels of Nestin and basic fibroblast growth factor in the basal ganglia,and increased the number of Nestin-and glial cell line-derived neurotrophic factor-positive cells in the basal ganglia.Together,these findings suggest that acupuncture promotes functional recovery after cerebral hemorrhage by increasing the expression of neurotrophic factors.The study was approved by the Committee for Experimental Animals of Heilongjiang Medical Laboratory Animal Center(approval No.2017061001)on June 10,2017.     

Urolithin A alleviates blood-brain barrier disruption and attenuates neuronal apoptosis following traumatic brain injury in mice

Urolithin A(UA)is a natural metabolite produced from polyphenolics in foods such as pomegranates,berries,and nuts.UA is neuroprotective against Parkinson’s disease,Alzheimer’s disease,and cerebral hemorrhage.However,its effect against traumatic brain injury remains unknown.In this study,we established adult C57BL/6J mouse models of traumatic brain injury by controlled cortical impact and then intraperitoneally administered UA.We found that UA greatly reduced brain edema;increased the expression of tight junction proteins in injured cortex;increased the immunopositivity of two neuronal autophagy markers,microtubule-associated protein 1A/B light chain 3A/B(LC3)and p62;downregulated protein kinase B(Akt)and mammalian target of rapamycin(mTOR),two regulators of the phosphatidylinositol 3-kinase(PI3K)/Akt/mTOR signaling pathway;decreased the phosphorylation levels of inhibitor of NFκB(IκB)kinase alpha(IKKα)and nuclear factor kappa B(NFκB),two regulators of the neuroinflammation-related Akt/IKK/NFκB signaling pathway;reduced blood-brain barrier permeability and neuronal apoptosis in injured cortex;and improved mouse neurological function.These findings suggest that UA may be a candidate drug for the treatment of traumatic brain injury,and its neuroprotective effects may be mediated by inhibition of the PI3K/Akt/mTOR and Akt/IKK/NFκB signaling pathways,thus reducing neuroinflammation and enhancing autophagy.     

Abstracts A1–A10

Journal of Neurology -     

A catalog of SCN1A variants

Over the past 10 years mutations in voltage-gated sodium channels (Na(v)s) have become closely associated with inheritable forms of epilepsy. One isoform in particular, Na(v)1.1 (gene symbol SCN1A), appears to be a superculprit, registering with more than 330 mutations to date. The associated phenotypes range from benign febrile seizures to extremely serious conditions, such as Dravet's syndrome (SMEI). Despite the wealth of information, mutational analyses are cumbersome, owing to inconsistencies among the Na(v)1.1 sequences to which different research groups refer. Splicing variability is the core problem: Na(v)1.1 co-exists in three isoforms, two of them lack 11 or 28 amino acids compared to full-length Na(v).1.1. This review establishes a standardized nomenclature for Na(v)1.1 variants so as to provide a platform from which future mutation analyses can be started without need for up-front data normalization. An online resource--SCN1A infobase--is introduced.     

A clinically isolated syndrome: A challenging entity

Abstract   Acute isolated neurological syndromes, such as optic neuropathy or transverse myelopathy, may cause diagnostic problems since they can be the first presentations of a number of diseases such as multiple sclerosis (MS) and collageneous tissue disorders. In the present study, particular systemic lupus erythematosus (SLE) and primary Sjogren syndrome (pSS) patients, who were followed up with the initial diagnosis of possible MS with no evidence of collagen tissue disorders for several years, are described. Five patients with the final diagnosis of SLE and five pSS patients are evaluated with their neurologic, systemic and radiologic findings. Over several years, all developed some systemic symptoms like arthritis, arthralgia, headache, dry mouth and eyes unexpected in MS. During the regular and close follow-up laboratory evaluations of vasculitic markers revealed positivity, leading to the final definite diagnosis of SLE or pSS. Patients with atypical neurological presentation of MS, a relapsing remitting clinical profile, or lack of response to the regular MS treatment should be evaluated for the presence of a connective tissue disease. Various laboratory tests, such as cerebrospinal fluid findings, autoantibodies profile, markers, cranial and spinal magnetic resonance imaging, can be helpful for the differential diagnosis. Lack of response to the regular multiple sclerosis treatment, even increasing rate of relapses can force the clinician for the differential diagnosis. In particular cases an accurate diagnosis can only be made after close follow-up.     

A neurosurgeon in Iraq: A personal perspective

The practice of neurosurgery in a war zone provides enormous challenges and risks for the individual surgeon working in such an austere and hostile environment, but also provides a unique opportunity to treat a high volume of severe penetrating and blast injuries to the head, neck and the spine. The purpose of this article is to present the author's personal experiences and perspective as a military neurosurgeon working in the US Airforce Hospital in Balad (the 332nd Expeditionary Medical Group) Iraq in for 3 months in 2004. Strategies for managing the mass casualties, and the severe penetrating craniofacial trauma are presented and the reasons for the low mortality of troops injured in Iraq are discussed.