The expanding role of nerve growth factor: from neurotrophic activity to immunologic diseases

Multifaceted Roles of Nerve Growth Factor: A Comprehensive Review with a Special Insight into Pediatric Perspectives

Nerve growth factor (NGF) is a neurotrophic peptide largely revealed for its ability to regulate the growth and survival of peripheral sensory, sympathetic, and central cholinergic neurons. The pro-survival and regenerative properties of neurotrophic factors propose a therapeutic potential in a wide range of brain diseases, and NGF, in particular, has appeared as an encouraging potential treatment. In this review, a summary of clinical studies regarding NGF and its therapeutic effects published to date, with a specific interest in the pediatric context, will be attempted. NGF has been studied in neurological disorders such as hypoxic-ischemic encephalopathy, traumatic brain injury, neurobehavioral and neurodevelopmental diseases, congenital malformations, cerebral infections, and in oncological and ocular diseases. The potential of NGF to support neuronal survival, repair, and plasticity in these contexts is highlighted. Emerging therapeutic strategies for NGF delivery, including intranasal administration as well as advanced nanotechnology-based methods, are discussed. These techniques aim to enhance NGF bioavailability and target specificity, optimizing therapeutic outcomes while minimizing systemic side effects. By synthesizing current research, this review underscores the promise and challenges of NGF-based therapies in pediatric neurology, advocating for continued innovation in delivery methods to fully harness NGF's therapeutic potential.

Neurotrophic Factors in Cannabis-induced Psychosis: An Update

BACKGROUND

Cannabis is the most widely used illicit substance. Numerous scientific evidence confirm the strong association between cannabis and psychosis. Exposure to cannabis can induce the development of psychosis and schizophrenia in vulnerable individuals. However, the neurobiological processes underlying this relationship are unknown. Neurotrophins are a class of proteins that serve as survival factors for central nervous system (CNS) neurons. In particular, Nerve Growth Factor (NGF) plays an important role in the survival and function of cholinergic neurons while Brain Derived Neurotrophic Factor (BDNF) is involved in synaptic plasticity and the maintenance of midbrain dopaminergic and cholinergic neurons. Glial Cell Derived Neurotrophic Factor (GDNF) promotes the survival of midbrain dopaminergic neurons and Neuregulin 1 (NrG- 1) contributes to glutamatergic signals regulating the N-methyl-D-aspartate (NMDA). They have a remarkable influence on the neurons involved in the Δ-9-THC (tethra-hydro-cannabinol) action, such as dopaminergic and glutamatergic neurons, and can play dual roles: first, in neuronal survival and death, and, second, in activity-dependent plasticity.

METHODS

In this brief update, reviewing in a narrative way the relevant literature, we will focus on the effects of cannabis on this class of proteins, which may be implicated, at least in part, in the mechanism of the psychostimulant-induced neurotoxicity and psychosis.

CONCLUSION

Since altered levels of neurotrophins may participate in the pathogenesis of psychotic disorders which are common in drug users, one possible hypothesis is that repeated cannabis exposure can cause psychosis by interfering with neurotrophins synthesis and utilization by CNS neurons.

Lost in Translation: Neurotrophins Biology and Function in the Neurovascular Unit

The neurovascular unit (NVU) refers to the functional building unit of the brain and the retina, where neurons, glia, and microvasculature orchestrate to meet the demand of the retina's and brain's function. Neurotrophins (NTs) are structural families of secreted proteins and are known for exerting neurotrophic effects on neuronal differentiation, survival, neurite outgrowth, synaptic formation, and plasticity. NTs include several molecules, such as nerve growth factor, brain-derived neurotrophic factor, NT-3, NT-4, and their precursors. Furthermore, NTs are involved in signaling pathways such as inflammation, apoptosis, and angiogenesis in a nonneuronal cell type. Interestingly, NTs and the precursors can bind and activate the p75 neurotrophin receptor (p75NTR) at low and high affinity. Mature NTs bind their cognate tropomyosin/tyrosine-regulated kinase receptors, crucial for maintenance and neuronal development in the brain and retina axis. Activation of p75NTR results in neuronal apoptosis and cell death, while tropomysin receptor kinase upregulation contributes to differentiation and cell growth. Recent findings indicate that modulation of NTs and their receptors contribute to neurovascular dysfunction in the NVU. Several chronic metabolic and acute ischemic diseases affect the NVU, including diabetic and ischemic retinopathy for the retina, as well as stroke, acute encephalitis, and traumatic brain injury for the brain. This work aims to review the current evidence through published literature studying the impact of NTs and their receptors, including the p75NTR receptor, on the injured and healthy brain-retina axis.

Nerve Growth Factor and Autoimmune Diseases

NGF plays a crucial immunomodulatory role and increased levels are found in numerous tissues during autoimmune states. NGF directly modulates innate and adaptive immune responses of B and T cells and causes the release of neuropeptides and neurotransmitters controlling the immune system activation in inflamed tissues. Evidence suggests that NGF is involved in the pathogenesis of numerous immune diseases including autoimmune thyroiditis, chronic arthritis, multiple sclerosis, systemic lupus erythematosus, mastocytosis, and chronic granulomatous disease. Furthermore, as NGF levels have been linked to disease severity, it could be considered an optimal early biomarker to identify therapeutic approach efficacy. In conclusion, by gaining insights into how these molecules function and which cells they interact with, future studies can devise targeted therapies to address various neurological, immunological, and other disorders more effectively. This knowledge may pave the way for innovative treatments based on NGF manipulation aimed at improving the quality of life for individuals affected by diseases involving neurotrophins.

Therapeutic Plasma Exchange and Multiple Sclerosis Dysregulations: Focus on the Removal of Pathogenic Circulatory Factors and Altering Nerve Growth Factor and Sphingosine-1-Phosphate Plasma Levels

Multiple sclerosis (MS) is predominantly an immune-mediated disease of the central nervous system (CNS) of unknown etiology with a possible genetic predisposition and effect of certain environmental factors. It is generally accepted that the disease begins with an autoimmune inflammatory reaction targeting oligodendrocytes followed by a rapid depletion of their regenerative capacity with subsequent permanent neurodegenerative changes and disability. Recent research highlights the central role of B lymphocytes and the corresponding IgG and IgM autoantibodies in newly forming MS lesions. Thus, their removal along with the modulation of certain bioactive molecules to improve neuroprotection using therapeutic plasma exchange (TPE) becomes of utmost importance. Recently, it has been proposed to determine the levels and precise effects of both beneficial and harmful components in the serum of MS patients undergoing TPE to serve as markers for appropriate TPE protocols. In this review we discuss some relevant examples, focusing on the removal of pathogenic circulating factors and altering the plasma levels of nerve growth factor and sphingosine-1-phosphate by TPE. Altered plasma levels of the reviewed molecular compounds in response to TPE reflect a successful reduction of the pro-inflammatory burden at the expense of an increase in anti-inflammatory potential in the circulatory and CNS compartments.

Unveiling the Neural Environment in Cancer: Exploring the Role of Neural Circuit Players and Potential Therapeutic Strategies

The regulation of the immune environment within the tumor microenvironment has provided new opportunities for cancer treatment. However, an important microenvironment surrounding cancer that is often overlooked despite its significance in cancer progression is the neural environment surrounding the tumor. The release of neurotrophic factors from cancer cells is implicated in cancer growth and metastasis by facilitating the infiltration of nerve cells into the tumor microenvironment. This nerve-tumor interplay can elicit cancer cell proliferation, migration, and invasion in response to neurotransmitters. Moreover, it is possible that cancer cells could establish a network resembling that of neurons, allowing them to communicate with one another through neurotransmitters. The expression levels of players in the neural circuits of cancers could serve as potential biomarkers for cancer aggressiveness. Notably, the upregulation of certain players in the neural circuit has been linked to poor prognosis in specific cancer types such as breast cancer, pancreatic cancer, basal cell carcinoma, and stomach cancer. Targeting these players with inhibitors holds great potential for reducing the morbidity and mortality of these carcinomas. However, the efficacy of anti-neurogenic agents in cancer therapy remains underexplored, and further research is necessary to evaluate their effectiveness as a novel approach for cancer treatment. This review summarizes the current knowledge on the role of players in the neural circuits of cancers and the potential of anti-neurogenic agents for cancer therapy.

Growth factors and their peptide mimetics for treatment of traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of disability in adults, caused by a physical insult damaging the brain. Growth factor-based therapies have the potential to reduce the effects of secondary injury and improve outcomes by providing neuroprotection against glutamate excitotoxicity, oxidative damage, hypoxia, and ischemia, as well as promoting neurite outgrowth and the formation of new blood vessels. Despite promising evidence in preclinical studies, few neurotrophic factors have been tested in clinical trials for TBI. Translation to the clinic is not trivial and is limited by the short in vivo half-life of the protein, the inability to cross the blood-brain barrier and human delivery systems. Synthetic peptide mimetics have the potential to be used in place of recombinant growth factors, activating the same downstream signalling pathways, with a decrease in size and more favourable pharmacokinetic properties. In this review, we will discuss growth factors with the potential to modulate damage caused by secondary injury mechanisms following a traumatic brain injury that have been trialled in other indications including spinal cord injury, stroke and neurodegenerative diseases. Peptide mimetics of nerve growth factor (NGF), hepatocyte growth factor (HGF), glial cell line-derived growth factor (GDNF), brain-derived neurotrophic factor (BDNF), platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) will be highlighted, most of which have not yet been tested in preclinical or clinical models of TBI.

Neurotrophins: are they involved in immune tolerance in pregnancy?

In this review, an attempt was made to substantiate the possibility for neurotrophins to be involved in the development of immune tolerance based on data accumulated on neurotrophin content and receptor expression in the trophoblast and immune cells, in particular, in natural killer cells. Numerous research results are reviewed to show that the expression and localization of neurotrophins along with their high-affinity tyrosine kinase receptors and low-affinity p75NTR receptor in the mother-placenta-fetus system indicate the important role of neurotrophins as binding molecules in regulating the crosstalk between the nervous, endocrine, and immune systems in pregnancy. An imbalance between these systems can occur with tumor growth and pathological processes observed in pregnancy complications and fetal development anomalies.

Blood levels of brain-derived neurotrophic factor (BDNF) in systemic lupus erythematous (SLE): a systematic review and meta-analysis

OBJECTIVES

BDNF has been implicated in the pathophysiology of systemic lupus erythematosus (SLE), especially its neuropsychiatric symptoms. The purpose of this study was to investigate the profile of blood BDNF levels in patients with SLE.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library for papers that compared BDNF levels in SLE patients and healthy controls (HCs). The Newcastle-Ottawa scale was used to assess the quality of the included publications, and statistical analyses were carried out using R 4.0.4.

RESULTS

The final analysis included eight studies totaling 323 healthy controls and 658 SLE patients. Meta-analysis did not show statistically significant differences in blood BDNF concentrations in SLE patients compared to HCs (SMD 0.08, 95% CI [ - 1.15; 1.32], P value = 0.89). After removing outliers, there was no significant change in the results: SMD -0.3868 (95% CI [ - 1.17; 0.39], P value = 0.33. Univariate meta-regression analysis revealed that sample size, number of males, NOS score, and mean age of the SLE participants accounted for the heterogeneity of the studies (R2 were 26.89%, 16.53%, 18.8%, and 49.96%, respectively).

CONCLUSION

In conclusion, our meta-analysis found no significant association between blood BDNF levels and SLE. The potential role and relevance of BDNF in SLE need to be further examined in higher quality studies.

Tissue Engineering Neovagina for Vaginoplasty in Mayer-Rokitansky-Küster-Hauser Syndrome and Gender Dysphoria Patients: A Systematic Review

Background: Vaginoplasty is a surgical solution to multiple disorders, including Mayer-Rokitansky-Küster-Hauser syndrome and male-to-female gender dysphoria. Using nonvaginal tissues for these reconstructions is associated with many complications, and autologous vaginal tissue may not be sufficient. The potential of tissue engineering for vaginoplasty was studied through a systematic bibliography search. Cell types, biomaterials, and signaling factors were analyzed by investigating advantages, disadvantages, complications, and research quantity. Search Methods: A systematic search was performed in Medline, EMBASE, Web of Science, and Scopus until March 8, 2022. Term combinations for tissue engineering, guided tissue regeneration, regenerative medicine, and tissue scaffold were applied, together with vaginoplasty and neovagina. The snowball method was performed on references and a Google Scholar search on the first 200 hits. Original research articles on human and/or animal subjects that met the inclusion (reconstruction of vaginal tissue and tissue engineering method) and no exclusion criteria (not available as full text; written in foreign language; nonoriginal study article; genital surgery other than neovaginal reconstruction; and vaginal reconstruction with autologous or allogenic tissue without tissue engineering or scaffold) were assessed. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist, the Newcastle-Ottawa Scale, and the Gold Standard Publication Checklist were used to evaluate article quality and bias. Outcomes: A total of 31 out of 1569 articles were included. Data extraction was based on cell origin and type, biomaterial nature and composition, host species, number of hosts and controls, neovaginal size, replacement fraction, and signaling factors. An overview of used tissue engineering methods for neovaginal formation was created, showing high variance of cell types, biomaterials, and signaling factors and the same topics were rarely covered multiple times. Autologous vaginal cells and extracellular matrix-based biomaterials showed preferential properties, and stem cells carry potential. However, quality confirmation of orthotopic cell-seeded acellular vaginal matrix by clinical trials is needed as well as exploration of signaling factors for vaginoplasty. Impact statement General article quality was weak to sufficient due to unreported cofounders and incomplete animal study descriptions. Article quality and heterogenicity made identification of optimal cell types, biomaterials, or signaling factors unreliable. However, trends showed that autologous cells prevent complications and compatibility issues such as healthy cell destruction, whereas stem cells prevent cross talk (interference of signaling pathways by signals from other cell types) and rejection (but need confirmation testing beyond animal trials). Natural (orthotopic) extracellular matrix biomaterials have great preferential properties that encourage future research, and signaling factors for vascularization are important for tissue engineering of full-sized neovagina.

Vitamin C (Ascorbic acid) protects from neuropathy caused by cisplatin, through enhanced heat shock protein-70 and reduced oxidant effect

OBJECTIVE:

We aimed to determine whether vitamin C has a protective effect on cisplatin-induced neuropathy in rats.

METHODS:

In total, 24 rats were included in the study of which 8 rats (no drug administered) were categorized as the control group. The remaining 16 rats were given a total dose of 20 mg/kg cisplatin to induce neuropathy. These drug-administered rats (16 rats) were randomly divided into two groups, namely, group-1 (n=8): cisplatin+saline and group-2 (n=8): cisplatin+vitamin C (500 mg/kg/day). All rats were tested for motor function and electromyographic activity 3 days after cisplatin. Motor performance was evaluated by an inclined-plane test. Compound muscle action potential was evaluated. Plasma malondialdehyde, glutathione, tumor necrosis factor-α, interleukin 6, and sciatic nerve HSP 70 levels were measured. Axon diameter and nerve growth factor expression levels were analyzed.

RESULTS:

Plasma malondialdehyde, tumor necrosis factor-α, and interleukin 6 levels were higher in the cisplatin+saline group than control group (p<0.001). But vitamin C significantly reduced malondialdehyde and inflammatory cytokine levels when compared with the cisplatin+saline group (p<0.001). Glutathione levels were lower in both cisplatin+saline and cisplatin+vitamin C groups than control group, but vitamin C significantly ameliorated the glutathione levels (p<0.05). Sciatic heat shock protein-70 levels were significantly higher in the cisplatin+vitamin C group than cisplatin+saline group. Compound muscle action potential amplitude and inclined plane test scores were significantly improved in the vitamin C group (p<0.05). Axon diameter and nerve growth factor expression ameliorated with vitamin C (p<0.05).

CONCLUSIONS:

We demonstrated the ameliorated effects of vitamin C on cisplatin-induced neuropathy through increased heat shock protein-70, nerve growth factor levels, and reduced inflammatory and oxidant effects. The results are promising to improve the neurotoxic effects of cisplatin in cancer patients.

A Microglial Function for the Nerve Growth Factor: Predictions of the Unpredictable

Microglia are the only immune cell population present in the brain parenchyma. Their vantage position in the central nervous system (CNS) enables these myeloid cells to perform the most disparate of tasks: from the classical immune functions of fighting infections and surveilling the extracellular space for pathogens and damage, to sculpting the neuronal circuitry by pruning unnecessary synapses and assisting neurons in spine formation, aiding in the maintenance of brain homeostasis. The neurotrophin field has always been dominated by the neurocentric view that the primary target of these molecules must be neurons: this holds true even for the Nerve Growth Factor (NGF), which owes its popularity in the neuroscience community to its trophic and tropic activity towards sensory and sympathetic neurons in the peripheral nervous system, and cholinergic neurons in the CNS. The increasing evidence that microglia are an integral part of neuronal computation calls for a closer look as to whether these glial cells are capable of responding directly to NGF. In this review, we will first outline evidence in support of a role for NGF as a molecule mediating neuroimmune communication. Then, we will illustrate some of those non-immune features that have made microglial cells one of the hottest topics of this last decade. In conclusion, we will discuss evidence in support of a microglial function for NGF.

Nerve Growth Factor in Alcohol Use Disorders

The nerve growth factor (NGF) belongs to the family of neurotrophic factors. Initially discovered as a signaling molecule involved in the survival, protection, differentiation, and proliferation of sympathetic and peripheral sensory neurons, it also participates in the regulation of the immune system and endocrine system. NGF biological activity is due to the binding of two classes of receptors: the tropomyosin-related kinase A (TrkA) and the low-affinity NGF pan-neurotrophin receptor p75. Alcohol Use Disorders (AUD) are one of the most frequent mental disorders in developed countries, characterized by heavy drinking, despite the negative effects of alcohol on brain development and cognitive functions that cause individual’s work, medical, legal, educational, and social life problems. In addition, alcohol consumption during pregnancy disrupts the development of the fetal brain causing a wide range of neurobehavioral outcomes collectively known as fetal alcohol spectrum disorders (FASD). The rationale of this review is to describe crucial findings on the role of NGF in humans and animals, when exposed to prenatal, chronic alcohol consumption, and on binge drinking.

Changing Expression Profiles of Messenger RNA, MicroRNA, Long Non-coding RNA, and Circular RNA Reveal the Key Regulators and Interaction Networks of Competing Endogenous RNA in Pulmonary Fibrosis

Pulmonary fibrosis is a kind of interstitial lung disease with architectural remodeling of tissues and excessive matrix deposition. Apart from messenger RNA (mRNA), microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) could also play important roles in the regulatory processes of occurrence and progression of pulmonary fibrosis. In the present study, the pulmonary fibrosis model was administered with bleomycin. Whole transcriptome sequencing analysis was applied to investigate the expression profiles of mRNAs, lncRNAs, circRNAs, and miRNAs. After comparing bleomycin-induced pulmonary fibrosis model lung samples and controls, 286 lncRNAs, 192 mRNAs, 605 circRNAs, and 32 miRNAs were found to be differentially expressed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to investigate the potential functions of these differentially expressed (DE) mRNAs and non-coding RNAs (ncRNAs). The terms related to inflammatory response and tumor necrosis factor (TNF) signaling pathway were enriched, implying potential roles in regulatory process. In addition, two co-expression networks were also constructed to understand the internal regulating relationships of these mRNAs and ncRNAs. Our study provides a systematic perspective on the potential functions of these DE mRNAs and ncRNAs during PF process and could help pave the way for effective therapeutics for this devastating and complex disease.

Short Communication: Interaction of Nerve Growth Factor (NGF) and Vascular Endothelial Growth Factor (VEGF) in Healthy Individuals

NGF and VEGF are known to be involved in different psychiatric diseases. In order to verify hints from basic research that both neurotrophines interact with each other, serum levels of NGF and VEGF were measured in a cohort of 33 healthy individuals and correlated. NGF level was 126.30 pg/mL (±155.43), and VEGF level was 57.28 pg/mL (±44.48). Both factors were significantly correlated, confirming their interaction and legitimising the usage of their respective ratio (0.8 (±0.42)) as a less varying additional marker in prospective studies.

Effects of Cerebrolysin® in Patients With Minimally Conscious State After Stroke: An Observational Retrospective Clinical Study

Introduction: The neurotrophic drug Cerebrolysin is composed of low-molecular-weight peptides and amino acids and has been shown to have neuroprotective and neuroplastic properties. Cerebrolysin has been reported to promote the recovery of motor functions in central nervous system disorders; however, the effects on the consciousness improvements in post-stroke patients have not yet been studied extensively. Therefore, we aimed to examine the effectiveness of Cerebrolysin on improving the consciousness level of stroke patients with minimally conscious state (MCS).

Materials and Methods: In this retrospective study we included ischemic and/or hemorrhagic stroke patients with MCS according to the Coma Recovery Scale-Revised (CRS-R), who were admitted to our hospital between 2014 and 2017. All patients received comprehensive rehabilitation therapy including physical and occupational therapy. We compared patients treated with Cerebrolysin against patients who did not receive Cerebrolysin. Patients were included in the verum group if they received 10 mL of Cerebrolysin IV for at least 20 days. CRS-R scores were assessed at admission and discharge.

Results: Of 1,531 patients screened, 75 were included in the study (Cerebrolysin, n = 43; control, n = 32). Baseline characteristics were similar between groups. At discharge, ~2 months after onset of stroke, Cerebrolysin-treated patients improved significantly in the CRS-R (p = 0.010) after adjustment for confounders using linear mixed model (LMM), especially in the Oromotor (p = 0.003) and Arousal subscales (p = 0.038). No safety issues were observed.

Conclusion: This retrospective study suggests that Cerebrolysin may improve the level of consciousness in stroke patients with MCS, which should be further investigated in a well-designed, double-blind, placebo-controlled, randomized trial.

Efficient Delivery of Nerve Growth Factors to the Central Nervous System for Neural Regeneration

The central nervous system (CNS) plays a central role in the control of sensory and motor functions, and the disruption of its barriers can result in severe and debilitating neurological disorders. Neurotrophins are promising therapeutic agents for neural regeneration in the damaged CNS. However, their penetration across the blood-brain barrier remains a formidable challenge, representing a bottleneck for brain and spinal cord therapy. Herein, a nanocapsule-based delivery system is reported that enables intravenously injected nerve growth factor (NGF) to enter the CNS in healthy mice and nonhuman primates. Under pathological conditions, the delivery of NGF enables neural regeneration, tissue remodeling, and functional recovery in mice with spinal cord injury. This technology can be utilized to deliver other neurotrophins and growth factors to the CNS, opening a new avenue for tissue engineering and the treatment of CNS disorders and neurodegenerative diseases.

Peripheral blood brain-derived neurotrophic factor level and tyrosine kinase B expression on T lymphocytes in systemic lupus erythematosus: Implications for systemic involvement

OBJECTIVE

Brain-derived neurotrophic factor (BDNF) has been reported to be involved in the pathogenesis of autoimmune diseases and tyrosine kinase B (TrkB) is the specific receptor for BDNF. Our aim in this study was to investigate serum BDNF level and TrkB expression on peripheral blood T cell surface in patients with systemic lupus erythematosus (SLE) and explore potential relationship between serum BDNF and SLE.

METHODS

Samples from fifty SLE patients and thirty healthy controls were evaluated. Serum BDNF level was measured by enzyme-linked immunosorbent assay (ELISA) and the percentages of TrkB expression on the surface of CD3 + CD4 + and CD3 + CD8 + T lymphocytes were measured by flow cytometry. The SLE patients were divided into subgroups according to whether they exhibited brain, kidney or lung involvement, and whether the disease was active or inactive.

RESULTS

Serum BDNF levels in SLE patients were decreased when compared to the controls (p < 0.001). Comparing with the SLE individuals without systemic involvement, the BDNF levels were decreased in SLE patients with lupus nephritis (p = 0.042) and in SLE patients with neuropsychiatric manifestations (p = 0.04). On the other hand, the BDNF level was significantly increased in the inactive SLE group (p < 0.001) compared to the active SLE group. In addition, the percentages of TrkB expression on CD3 + CD4 + and CD3 + CD8 + T cell surface in SLE were significantly higher (p < 0.001; p < 0.001, respectively) than that in the controls.

CONCLUSIONS

Serum BDNF level combined with TrkB expression on T cell surface can reflect SLE activity. It is possible that BDNF may be used as a potential serological biomarker for disease activity of SLE. In addition, the significant decrease in serum BDNF level may imply systemic involvement of SLE, as well as, possibly, differentiate neuropsychiatric SLE from hormone-induced mental disorders.

Effect of ethylenediaminetetraacetic acid irrigation on immune-inflammatory response in teeth submitted to regenerative endodontic therapy

AIM

To analyse longitudinally the immune-inflammatory response in teeth of mice that underwent a regenerative protocol with or without the use of ethylenediaminetetraacetic acid (EDTA) to irrigate the root canal system.

METHODOLOGY

First maxillary molars of mice were devitalized using size 10 and 15 files. Teeth were divided into the following groups: Empty - the canals were left empty; Blood Clot (BC) - the canals were filled with a blood clot; and EDTA + Blood - the canals were irrigated with 0.06 mL of 17% EDTA for 1 min and filled with a blood clot. Access cavities were restored with Coltosol^® . Animals were sacrificed at 7, 14 or 21 days after the operative procedures, and teeth were collected. RNA was extracted, mRNA expression of the cytokines IGF, NGF, IL-1α, IL-10, TGF and VEGF was assessed using real-time PCR, and the anova Kruskal-Wallis test was used.

RESULTS

IL-1 mRNA expression was significantly higher in the EDTA + BC group than in the Empty and BC groups at the 7th and 14th days of evaluation (P < 0.05). IL-10 mRNA expression was similar across the three groups at all time periods. TGF-β mRNA expression in the EDTA + BC group was significantly higher on the 7th and 21st days than on the 14th (P < 0.05); at day 21, TGF-β mRNA expression was similar between the BC and EDTA + BC groups but significantly higher than in the Empty group (P < 0.05). IGF mRNA expression was significantly higher in the EDTA + BC group than in the other groups at all time periods. VEGF mRNA expression remained unchanged throughout the experimental period in all groups (P > 0.05). NGF mRNA expression was similar amongst all groups at the 7th and 21st days (P > 0.05). At the 14th day, however, there was a significant increase in NGF mRNA expression in the EDTA + Blood group (P < 0.05) when compared with the expression in the other groups.

CONCLUSION

EDTA promoted increased expression of factors that have the potential to improve the outcome of regenerative endodontic treatment.

Ubiquitin binds the amyloid β peptide and interferes with its clearance pathways

Several lines of evidence point to a compromised proteostasis associated with a reduction of the Ubiquitin Proteasome System (UPS) activity in patients affected by Alzheimer's Disease (AD) and suggest that the amyloid β peptide (Aβ) is an important player in the game. Inspired also by many reports, underlining the presence of ubiquitin (Ub) in the amyloid plaques of AD brains, here we set out to test whether Ub may bind the Aβ peptide and have any effect on its clearance pathways. By using an integrated array of MALDI-TOF/UPLC-HRMS, fluorescence, NMR, SPR, Microscale Thermophoresis (MST) and molecular dynamics studies, we consistently demonstrated that Aβ40 binds Ub with a 1 : 1 stoichiometry and K d in the high micromolar range. In particular, we show that the N-terminal domain of the Aβ peptide (through residues D1, E3 and R5) interacts with the C-terminal tail of Ub (involving residues K63 and E64), inducing the central region of Aβ (14HQKLVFFAEDVGSNK28) to adopt a mixed α-helix/β-turn structure. ELISA assays, carried out in neuroblastoma cell lysates, suggest that Aβ competitively binds Ub also in the presence of the entire pool of cytosolic Ub binding proteins. Ub-bound Aβ has a lower tendency to aggregate into amyloid-like fibrils and is more slowly degraded by the Insulin Degrading Enzyme (IDE). Finally, we observe that the water soluble fragment Aβ1-16 significantly inhibits Ub chain growth reactions. These results evidence how the non-covalent interaction between Aβ peptides and Ub may have relevant effects on the regulation of the upstream events of the UPS and pave the way to future in vivo studies addressing the role played by Aβ peptide in the malfunction of proteome maintenance occurring in AD.

A C-terminal cysteine residue is required for peptide-based inhibition of the NGF/TrkA interaction at nM concentrations: implications for peptide-based analgesics

Inhibition of the NGF/TrkA interaction presents an interesting alternative to the use of non-steroidal anti-inflammatories and/or opioids for the control of inflammatory, chronic and neuropathic pain. Most prominent of the current approaches to this therapy is the antibody Tanezumab, which is a late-stage development humanized monoclonal antibody that targets NGF. We sought to determine whether peptides might similarly inhibit the NGF/TrkA interaction and so serve as future therapeutic leads. Starting from two peptides that inhibit the NGF/TrkA interaction, we sought to eliminate a cysteine residue close to the C-terminal of both sequences, by an approach of mutagenic analysis and saturation mutagenesis of mutable residues. Elimination of cysteine from a therapeutic lead is desirable to circumvent manufacturing difficulties resulting from oxidation. Our analyses determined that the cysteine residue is not required for NGF binding, but is essential for inhibition of the NGF/TrkA interaction at pharmacologically relevant peptide concentrations. We conclude that a cysteine residue is required within potential peptide-based therapeutic leads and hypothesise that these peptides likely act as dimers, mirroring the dimeric structure of the TrkA receptor.

Hypericum perforatum chronic treatment affects cognitive parameters and brain neurotrophic factor levels

Objective:

To evaluate the effects of Hypericum perforatum (hypericum) on cognitive behavior and neurotrophic factor levels in the brain of male and female rats.

Methods:

Male and female Wistar rats were treated with hypericum or water during 28 days by gavage. The animals were then subjected to the open-field test, novel object recognition and step-down inhibitory avoidance test. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and glial cell-line derived neurotrophic factor (GDNF) levels were evaluated in the hippocampus and frontal cortex.

Results:

Hypericum impaired the acquisition of short- and long-term aversive memory in male rats, evaluated in the inhibitory avoidance test. Female rats had no immediate memory acquisition and decreased short-term memory acquisition in the inhibitory avoidance test. Hypericum also decreased the recognition index of male rats in the object recognition test. Female rats did not recognize the new object in either the short-term or the long-term memory tasks. Hypericum decreased BDNF in the hippocampus of male and female rats. Hypericum also decreased NGF in the hippocampus of female rats.

Conclusions:

The long-term administration of hypericum appears to cause significant cognitive impairment in rats, possibly through a reduction in the levels of neurotrophic factors. This effect was more expressive in females than in males.

In vitro Effects of Nerve Growth Factor on Cardiac Fibroblasts Proliferation, Cell Cycle, Migration, and Myofibroblast Transformation

Background:

Recent research indicates that nerve growth factor (NGF) promotes cardiac repair following myocardial infarction by promoting angiogenesis and cardiomyocyte survival. The purpose of this study was to investigate the effects of NGF on cardiac fibroblasts (CFs) proliferation, cell cycle, migration, and myofibroblast transformation in vitro.

Methods:

CFs were obtained from ventricles of neonatal Sprague-Dawley rats and incubated with various concentrations of NGF (0, 0.01, 0.1, 1, 10, and 100 ng/ml; 0 ng/ml was designated as the control group). Cell proliferation and cell cycle of the CFs were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry (FCM), respectively. A cell scratch wound model and transwell were carried out to observe effects of NGF on migration of CFs after 24 h of culture. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to measure α-smooth muscle actin (α-SMA) at mRNA and protein levels after CFs were incubated with various concentrations of NGF.

Results:

Expression of α-SMA measured by RT-PCR and Western blotting significantly increased in the 1 and 10 ng/ml NGF groups (P < 0.05). Absorbance values of CFs showed that NGF did not influence the proliferation of CFs (The A₄₉₀ values were 0.178 ± 0.038, 0.182 ± 0.011, 0.189 ± 0.005, 0.178 ± 0.010, 0.185 ± 0.025, and 0.177 ± 0.033, respectively, in the 0, 0.01, 0.1, 1, 10, and 100 ng/ml NGF groups [P = 0.800, 0.428, 0.981, 0.596, and 0.913, respectively, compared with control group]), and FCM analysis showed that the percentage of CFs in G0/G1, S, and G2/M phases was not changed (P > 0.05). The cell scratch wound model and transwell showed that CFs migration was not significantly different (P > 0.05).

Conclusion:

NGF induces myofibroblast transformation but does not influence proliferation, cell cycle, or migration of CFs in vitro.

Long-Term Non-Invasive Treatment via Intranasal Administration of Nerve Growth Factor Protects the Human Brain in Frontotemporal Dementia associated with Corticobasal Syndrome: A Pilot Study

Background:

Nerve growth factor (NGF) is known for playing a critical protective role on a number of brain neurons in mammals, including humans. NGF can be delivered to the CNS via nasal route and has a neuroprotective action in case of neurodegenerative diseases.

Objective:

The aim of this study is to investigate for the first time whether purified NGF can play a neuroprotective role on human brain neurons affected by neurodegenerative diseases when administered via nasal route.

Methods:

Two female patients, both affected by frontotemporal dementia (FTD) associated with corticobasal syndrome (CBS) at different stages of disease progression, received a daily intranasal NGF spray for one year. Clinical/neurological aspects were observed over time. The follow-up study was performed using 18 FDG PET.

Results:

This case study seems to demonstrate that IN-NGF slows down the common decline caused by FTD/CBS.

Conclusions:

These findings suggest the potential neuroprotective role of IN-NGF administered in case of neurodegenerative diseases.

Perceived Discrimination, Racial Identity, and Multisystem Stress Response to Social Evaluative Threat Among African American Men and Women

OBJECTIVE

Understanding individual differences in the psychobiology of the stress response is critical to grasping how psychosocial factors contribute to racial and ethnic health disparities. However, the ways in which environmentally sensitive biological systems coordinate in response to acute stress is not well understood. We used a social-evaluative stress task to investigate coordination among the autonomic nervous system, hypothalamic-pituitary-adrenal axis, and immune/inflammatory system in a community sample of 85 healthy African American men and women.

METHODS

Six saliva samples, 2 at each of baseline, event, and recovery phases of the stressor task, were assayed for cortisol, dehydroepiandrosterone-sulfate, salivary alpha-amylase, and salivary C-reactive protein. Individual differences in perceived discrimination and racial identity were also measured.

RESULTS

Factor analysis demonstrated that stress systems were largely dissociated before stressor exposure but became aligned during event and recovery phases into functional biological stress responses (factor loadings ≥ .58). Coordinated responses were related to interactions of perceived discrimination and racial identity: when racial identity was strong, highly perceived discrimination was associated with low hypothalamic-pituitary-adrenal axis activity at baseline (B's = .68-.72, p < .001), low stress mobilization during the task (B's = .46-.62, p < .049), and a robust inflammatory response (salivary C-reactive protein) during recovery (B's = .72-.94, p < .002).

CONCLUSION

Culturally relevant social perceptions may be linked to a specific pattern of changing alignment in biological components of the stress response. Better understanding these links may significantly advance understanding of stress-related illnesses and disparities.

Attention Deficit Disorder and Allergic Rhinitis: Are They Related?

The association between ADHD and allergy remains controversial. Our previous findings suggest that nerve growth factor may link the nervous and immune systems. The primary objective of this study was to determine if a combination of cetirizine + methylphenidate is effective in children with comorbid ADHD and allergic rhinitis. We also examined the role of nerve growth factor in these comorbidities. Our randomized, double-blind, placebo-controlled, crossover study enrolled 38 children diagnosed with comorbid ADHD and allergy using cetirizine (n = 12), sustained-release methylphenidate (n = 12), or cetirizine + methylphenidate (n = 14). Endpoints compared baseline to posttreatment evaluations for allergic rhinitis and ADHD scores. Serum nerve growth factor levels were measured using ELISA. For allergy endpoints, combination therapy produced results superior to individual therapy. For ADHD, similar scores were achieved for individual therapy; however, combination therapy resulted in improved scores. Nerve growth factor levels were downregulated following this trend. We conclude that ADHD and allergic rhinitis may have common mechanism and represent a comorbid condition that links the nervous system to the immune system. Further studies are needed.

Ubiquitin Associates with the N-Terminal Domain of Nerve Growth Factor: The Role of Copper(II) Ions

Many biochemical pathways involving nerve growth factor (NGF), a neurotrophin with copper(II) binding abilities, are regulated by the ubiquitin (Ub) proteasome system. However, whether NGF binds Ub and the role played by copper(II) ions in modulating their interactions have not yet been investigated. Herein NMR spectroscopy, circular dichroism, ESI-MS, and titration calorimetry are employed to characterize the interactions of NGF with Ub. NGF_1-14 , which is a short model peptide encompassing the first 14 N-terminal residues of NGF, binds the copper-binding regions of Ub (K_D =8.6 10^-5  m). Moreover, the peptide undergoes a random coil-polyproline type II helix structural conversion upon binding to Ub. Notably, copper(II) ions inhibit NGF_1-14 /Ub interactions. Further experiments performed with the full-length NGF confirmed the existence of a copper(II)-dependent association between Ub and NGF and indicated that the N-terminal domain of NGF was a valuable paradigm that recapitulated many traits of the full-length protein.

Paternal alcohol exposure in mice alters brain NGF and BDNF and increases ethanol-elicited preference in male offspring

Ethanol (EtOH) exposure during pregnancy induces cognitive and physiological deficits in the offspring. However, the role of paternal alcohol exposure (PAE) on offspring EtOH sensitivity and neurotrophins has not received much attention. The present study examined whether PAE may disrupt nerve growth factor (NGF) and/or brain-derived neurotrophic factor (BDNF) and affect EtOH preference/rewarding properties in the male offspring. CD1 sire mice were chronically addicted for EtOH or administered with sucrose. Their male offsprings when adult were assessed for EtOH preference by a conditioned place preference paradigm. NGF and BDNF, their receptors (p75(NTR) , TrkA and TrkB), dopamine active transporter (DAT), dopamine receptors D1 and D2, pro-NGF and pro-BDNF were also evaluated in brain areas. PAE affected NGF levels in frontal cortex, striatum, olfactory lobes, hippocampus and hypothalamus. BDNF alterations in frontal cortex, striatum and olfactory lobes were found. PAE induced a higher susceptibility to the EtOH rewarding effects mostly evident at the lower concentration (0.5 g/kg) that was ineffective in non-PAE offsprings. Moreover, higher ethanol concentrations (1.5 g/kg) produced an aversive response in PAE animals and a significant preference in non-PAE offspring. PAE affected also TrkA in the hippocampus and p75(NTR) in the frontal cortex. DAT was affected in the olfactory lobes in PAE animals treated with 0.5 g/kg of ethanol while no differences were found on D1/D2 receptors and for pro-NGF or pro-BDNF. In conclusion, this study shows that: PAE affects NGF and BDNF expression in the mouse brain; PAE may induce ethanol intake preference in the male offspring.

VGF expression by T lymphocytes in patients with Alzheimer's disease

Secretion of VGF is increased in cerebrospinal fluid and blood in neurodegenerative disorders like Alzheimer's disease (AD) and VGF is a potential biomarker for these disorders. We have shown that VGF is expressed in peripheral T cells and is correlated with T cell survival and cytokine secretion. The frequency of VGF+CD3+ T cells increases with normal aging. We found an increased number of VGF-expressing T cells in patients with AD compared to aged healthy controls, which was associated with enhanced HbA1c levels in blood. Upon treatment with rivastigmine, T cell proliferation and VGF expression in AD patients decreased to the level found in controls. Moreover, rapamycin treatment in vitro reduced the number of VGF+CD3+ cells in AD patients to control levels.

Measurements of C-reactive protein (CRP) and nerve-growth-factor (NGF) concentrations in serum and urine samples of dogs with neurologic disorders

BACKGROUND

The purpose of this study was to prove the hypothesis that C-reactive protein (CRP) and nerve growth factor (NGF) may be potential biomarkers for lower urinary tract disorders and may be able to distinguish between micturition dysfunctions of different origin in dogs with spinal cord diseases. NGF- and CRP- concentrations were measured in serum and urine samples using specific ELISA-Kits. Results in urine were standardized by urine-creatinine levels.

RESULTS

CRP in serum was detectable in 32/76 and in urine samples in 40/76 patients. NGF could be measured in all serum and in 70/76 urine samples. Urinary CRP concentrations were significantly higher in dogs with micturition dysfunction (p = 0.0009) and in dogs with different neurological diseases (p = 0.0020) compared to the control group. However, comparing dogs with spinal cord disorders with and without associated micturition dysfunction no significant difference could be detected for NGF and CRP values in urine or serum samples. Additionally, levels did not decrease significantly, when measured at the time when the dogs regained the ability to urinate properly (urinary NGF p = 0.7962; urinary CRP p = 0.078). Urine samples with bacteria and/or leukocytes had no significant increase in urinary NGF (p = 0.1112) or CRP (p = 0.0534) concentrations, but higher CRP-levels in urine from dogs with cystitis were found compared to dogs without signs of cystitis.

CONCLUSIONS

From these data we conclude that neither CRP nor NGF in urine or serum can be considered as reliable biomarkers for micturition disorders in dogs with spinal cord disorders in a clinical setting, but their production might be part of the pathogenesis of such disorders. Significantly higher levels of CRP could be found in the urine of dogs with micturition dysfunctions compared to control dogs. This phenomenon could potentially be explained by unspecific extrahepatic CRP production by smooth muscle cells in the dilated bladder.

SP, CGRP changes in pyridoxine induced neuropathic dogs with nerve growth factor gene therapy

BACKGROUND

Nerve growth factor (NGF) is known not only as a major factor for neuronal plasticity but also as a pain stimulator. Although there have been several trials with NGF for its application in the regeneration or protection of the nervous system, the pain induced by NGF remains a challenge to be overcome. In this study, the pain induced by NGF gene therapy was evaluated.

RESULTS

Vehicle or recombinant dog NGF plasmid was administered into the intrathecal space of dogs. Twenty-four hours after the vehicle or NGF plasmid inoculation, dogs were subcutaneously treated with 150 mg/kg pyridoxine every day for 7 days. For pain assessment, physical examination and electrophysiological recording were performed. Only in the vehicle-treated group, weight loss occurred, while NGF plasmid inoculation significantly improved this physical abnormalities. In the vehicle-treated group, electrophysiological recordings showed that H-reflex disappeared at 24 h after the last pyridoxine treatment. However, in the NGF plasmid inoculated group, the H-reflex were normal. In the results of immunohistochemistry, the NGF plasmid administration efficiently expressed in the dorsal root ganglia and significantly increased the pyridoxine-induced reduction of calcitonin gene-related peptide (CGRP) immunoreactive neurons, but not in substance P immunoreactive neurons, in the dorsal root ganglia.

CONCLUSIONS

Given these results, we reason that NGF gene therapy in pyridoxine induced neuropathic dogs does not induce neuropathic pain with this dosage, even with increasing the expression of CGRP.

Potential Biomarkers Utilized to Define and Manage Overactive Bladder Syndrome

Clinical diagnosis of overactive bladder (OAB) syndrome has great variation and usually can only be based on subjective symptoms. Measurement of urgency severity score in adjunct with voiding diary may reflect the occurrence of OAB and incontinence severity in daily life. Urodynamic study can detect detrusor overactivity (DO), but not in all OAB patients. A more objective way and less invasive tool to diagnose and assess therapeutic outcome in OAB patients is needed. Recent investigations of the potential biomarkers for OAB include urinary and serum biomarkers and bladder wall thickness. Evidence has also shown that urinary proteins, such as nerve growth factor (NGF) and prostaglandin E2 (PGE2 ) levels increase in patients with OAB, bladder outlet obstruction (BOO) and DO. Patients with OAB have significantly higher urinary NGFlevels and urinary NGF levels decrease after antimuscarinic therapy and further decrease after detrusor botulinum toxin injections. However, the sensitivity of single urinary protein in the diagnosis of OAB is not high and several lower urinary tract diseases may also have elevated urinary NGF levels. Searching for a group of inflammatory biomarkers by microsphere-based array in urine might be a better method in differential diagnosis of OAB from interstitial cystitis, urinary tract infection (UTI) or urolithiasis. Bladder wall thickness has been widely investigated in the diagnosis of BOO and pediatric voiding dysfunction.The role of bladder wall thickness in the diagnosis of OAB, however, has not reach a consistent conclusion. We hereby review the latest medical advances in this field.

Imbalance of the Nerve Growth Factor and Its Precursor: Implication in Diabetic Retinopathy

Diabetic retinopathy is the leading cause of blindness in working age in US and worldwide. Neurotrophins including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) are known to be essential for growth, differentiation and survival of neurons in the developing and mature retina. Nevertheless, a growing body of evidence supports an emerging role of neurotrophins in retinal diseases and in particular, diabetic retinopathy. Neurotrophins are initially synthesized in a pro-form and undergo proteolytic cleavage to produce the mature form that activates two distinctive receptors, the tyrosine kinase tropomycin receptor (Trk) and, to lesser extent, the common low affinity p75 neurotrophin receptor (p75^NTR). Despite tight glycemic and metabolic control, many diabetic patients continue to experience progressive retinal damage. Understanding the molecular events involved in diabetic retinopathy is extremely important to identify novel therapeutic strategies to halt the disease progression. Diabetes induces imbalance in neurotrophins by increasing its proform, which is associated with upregulation of the p75^NTR receptor in the retina. A growing body of evidence supports a link between the imbalance of pro-neurotrophins and early retinal inflammation, neuro-and microvascular degeneration. Therefore, examining changes in the levels of neurotrophins and its receptors might provide a therapeutically beneficial target to combat disease progression in diabetic patients. This commentary aims to highlight the impact of diabetes-impaired balance of neurotrophins and in particular, the NGF and its receptors; TrkA and p75^NTR in the pathology of DR.

More signs of neurotoxicity of surfactants and flame retardants - Neonatal PFOS and PBDE 99 cause transcriptional alterations in cholinergic genes in the mouse CNS

Maternally and lactionally transferred persistent organic pollutants may interfere with CNS development. Here, 10-day-old male mice were exposed to single oral doses of PFOS (perflourooctanosulphonate) or PBDE 99 (2,2',4,4',5-penta-bromodiphenyl ether), and examined for changes in cholinergic gene transcription in the CNS 24h and 7 weeks later. 24h after exposure qPCR analyses revealed decreased transcription of nAChR-β2 and AChE in cortex, and increased mAChR-5 in hippocampus of PFOS treated mice. Neonatal PFOS treatment altered spontaneous behaviour at 2 months of age but did not affect gene transcription in adults. At 2 months of age neonatally PBDE 99 treated mice had altered spontaneous behaviour, and cortical transcription of AChE, nAChR-α4, nAChR-β2 and mAChR-5 were elevated. Our results indicate that PFOS and PBDE 99 affects the developing central cholinergic system by altering gene transcription in cortex and hippocampus, which may in part account for mechanisms causing changes in spontaneous behaviour.

Effects of Dioscoreae Rhizoma (SanYak) on Peripheral Neuropathy and its Safety

Objectives:

This study aimed to evaluate the evidence available in the literature for the safety and efficacy of Dioscoreae Rhizoma(DR) for the treatment of peripheral neuropathy.

Methods:

Literature searches were performed in MEDLINE and three Korean medical databases up to April 2013. All studies evaluating the effects on peripheral neuropathy or the safety of DR monopreparations were considered.

Results:

Three studies - DR extract per os (po) on diabetic neuropathy in mice, DR extract injection on the peripheral sciatic nerve after crush injury in rats and DR extract injection to patients with peripheral facial paralysis proved that DR treatments were effective for the treatment of nerve injuries.

Conclusions:

In conclusion, we found the DR has a strong positive potential for the treatment of peripheral neuropathy, but studies addressing direct factors related to the nerve still remain insufficient.

Brain-skin connection: stress, inflammation and skin aging

The intricate relationship between stress and skin conditions has been documented since ancient times. Recent clinical observations also link psychological stress to the onset or aggravation of multiple skin diseases. However, the exact underlying mechanisms have only been studied and partially revealed in the past 20 years or so. In this review, the authors will discuss the recent discoveries in the field of “Brain-Skin Connection”, summarizing findings from the overlapping fields of psychology, endocrinology, skin neurobiology, skin inflammation, immunology, and pharmacology.

Elevated serum levels of FGF-2, NGF and IGF-1 in patients with manic episode of bipolar disorder

Multiple neurotrophic and/or growth factors, recently nominated as "angioneurins", play the key roles in mood modulation and neuroplasticity, and their dysfunction might be involved in the pathophysiology and treatment of mood disorders. We examined serum levels of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF)-2, nerve growth factor (NGF) and insulin-like growth factor (IGF)-1 in 70 drug-naïve or drug-free patients with manic episode of bipolar disorder and 50 healthy controls, using the enzyme-linked immunosorbent assay (ELISA) method. The results showed that mean serum levels of VEGF, FGF-2, NGF and IGF-1 were 168.13±225.61pg/ml, 279.09±378.62pg/ml, 61.38±171.67pg/ml and 162.01±72.00ng/ml in patients, and 140.80±143.71pg/ml, 275.46±235.29pg/ml, 36.34±15.14pg/ml and 138.90±80.11ng/ml in healthy controls, respectively. Serum levels of FGF-2, NGF and IGF-1 in patients were significantly higher than those in healthy controls, though there was no statistical difference in serum VEGF level between two groups. Moreover, serum NGF level in patients was significantly correlated with duration of disorder and times of previous manic episodes. We conclude that the increase of serum FGF-2, NGF and IGF-1 levels in manic state of bipolar disorder may be associated with their compensatory roles of neuroprotection and angiogenesis, and these angioneurins may be involved in the pathophysiology of bipolar disorder.

Nerve growth factor modulation of retinal ganglion cell physiology

Nerve growth factor (NGF) is an endogenous neurotrophin involved in the development, maintenance and regeneration of mammalian sympathetic and sensory neurons. Additionally, NGF is known to have trophic and differentiating activity on several populations of cholinergic neurons of the central nervous system (CNS), and to act as a differentiation factor in the development of the visual cortex. The paramount functions of NGF in the visual system are also highlighted by the presence of this neurotrophin and both its receptors TrkA and p75 in most intra-ocular tissues, including lens, vitreous, choroid, iris, and trabecular meshwork. In the retina, NGF is produced and utilized specifically by retinal ganglion cells (RGC), bipolar neurons and glial cells, and is thought to have crucial protective effects in several disease states. Studies on the role of NGF on RGCs survival following optic nerve transection, ischemic injury, ocular hypertension and glaucoma are discussed in this review.

Participation of the neutrophin brain-derived neurotrophic factor in neuropsychiatric systemic lupus erythematosus

OBJECTIVE

Brain-derived neurotrophic factor (BDNF) is associated with the pathogenesis of several neuropsychiatric (NP) diseases, but there are few studies involving SLE. The aim of this study was to investigate whether plasma BDNF levels are associated with disease activity in SLE patients with severe NPSLE and non-NPSLE manifestations.

METHODS

We assessed 131 SLE patients and 24 randomly selected healthy individuals. SLE patients were evaluated in a cross-sectional study allocated according to the presence or not of NP manifestations and disease activity: (i) active NPSLE (n = 40), (ii) inactive NPSLE (n = 26), (iii) active SLE (n = 29) and (iv) inactive SLE (n = 36). In addition, NPSLE patients (n = 40) were evaluated before and after treatment. Disease activity was assessed according to the SLEDAI score. The plasma BDNF was measured by ELISA.

RESULTS

BDNF levels were increased in inactive NPSLE when compared with active SLE and controls (P < 0.0001). We observed similar findings in inactive SLE when compared with active SLE (P < 0.0001). In addition, we found an inverse correlation between plasma BDNF levels and the SLEDAI (r = -0.54, P < 0.0001) and a positive correlation with complement levels. We also observed an increase in BDNF levels in parallel with the improvement in NP symptoms.

CONCLUSION

Plasma BDNF level is increased in SLE patients and this increase is independent of the occurrence of NP manifestations. In addition, plasma BDNF levels increased with control of SLE activity, which points to the potential use of BDNF as a biomarker of response to treatment.

Hormonal influences on neuroimmune responses in the CNS of females

Particular reproductive stages such as lactation impose demands on the female. To cope with these demands, her physiology goes through numerous adaptations, for example, attenuation of immune and stress responses. Hormonal fluctuation during lactation exerts a strong influence, inducing neuroplasticity in the hypothalamus and extrahypothalamic regions, and diminishing the stress and inflammatory responses. Thus, hormones confer decreased vulnerability to the female brain. This mini-review focuses on the adaptations of the immune and stress response during maternity, and on the neuroprotective actions of progesterone and prolactin and their effects on inflammation. The importance of pregnancy and lactation as experimental models to study immune responses and disease is also highlighted.

Serum and lymphocytic neurotrophins profiles in systemic lupus erythematosus: a case-control study

BACKGROUND

Neurotrophins play a central role in the development and maintenance of the nervous system. However, neurotrophins can also modulate B and T cell proliferation and activation, especially via autocrine loops. We hypothesized that both serum and lymphocytic neurotrophin levels may be deregulated in systemic Lupus erythematosus (SLE) and may reflect clinical symptoms of the disease.

METHODS

Neurotrophins in the serum (ELISA tests) and lymphocytes (flow cytometry) were measured in 26 SLE patients and 26 control subjects. Th1 (interferon-γ) and Th2 (IL-10) profiles and serum concentration of BAFF were assessed by ELISA in the SLE and control subjects.

FINDINGS

We have demonstrated that both NGF and BDNF serum levels are higher in SLE patients than healthy controls (p=0.003 and p<0.001), independently of Th1 or Th2 profiles. Enhanced serum NT-3 levels (p=0.003) were only found in severe lupus flares (i.e. SLEDAI ≥ 10) and significantly correlated with complement activation (decreased CH 50, Γ=-0.28, p=0.03). Furthermore, there was a negative correlation between serum NGF levels and the number of circulating T regulatory cells (Γ=0.48, p=0.01). In circulating B cells, production of both NGF and BDNF was greater in SLE patients than in healthy controls. In particular, the number of NGF-secreting B cells correlated with decreased complement levels (p=0.05). One month after SLE flare treatment, BDNF levels decreased; in contrast, NGF and NT-3 levels remained unchanged.

CONCLUSION

This study demonstrates that serum and B cell levels of both NGF and BDNF are increased in SLE, suggesting that the neurotrophin production pathway is deregulated in this disease. These results must be confirmed in a larger study with naive SLE patients, in order to avoid the potential confounding influence of prior immune-modulating treatments on neurotrophin levels.

Expression of neuronal protein Kidins220/ARMS in the spleen and peripheral blood of mice following airway allergen challenge

Nerve growth factor (NGF), combined with the high-affinity tyrosine kinase receptor A (TrkA), has been reported to be involved in the pathogenesis of asthma. Ankyrin-rich membrane spanning/transmembrane substrate of protein kinase D (ARMS/Kidins220), a TrkA‑binding protein, modulates the NGF signaling pathway. The aim of the present study was to investigate the expression of Kidins220/ARMS and the effect NGF has on the protein in the spleen and peripheral blood, following airway allergen challenge in mice. BALB/c mice were sensitized and challenged with ovalbumin. The effects of NGF on Kidins220/ARMS in the spleen and peripheral blood of mice were assessed by administering anti-NGF antibody. Expression of ARMS, interleukin (IL)-1β and IL-4 in the spleen and peripheral blood was observed by reverse transcription-polymerase chain reaction, western blot analysis and immunohistochemistry. Pathological changes in the bronchi and lung tissues were examined by hematoxylin and eosin staining. Results showed that Kidins220/ARMS, IL-1β and IL-4 were overexpressed in the spleen and peripheral blood following allergen challenge, compared with the control mice. Moreover, following treatment with anti-NGF, the levels of Kidins220/ARMS, IL-1β and IL-4 in the mice were downregulated. Therefore, the results of the present study showed that Kidins220/ARMS is expressed in the spleen and peripheral blood of normal BALB/c mice and may participate in the immuno-inflammation of asthma through the NGF-mediated signaling pathway.

Changes in nerve growth factor level and symptom severity following antibiotic treatment for refractory overactive bladder

INTRODUCTION AND HYPOTHESIS

Overactive bladder (OAB) has a multifactorial aetiology, and for some women symptoms may be associated with chronic urothelial inflammation secondary to bacterial colonisation. One marker of such inflammation may be urinary nerve growth factor (NGF). We hypothesised that for women with OAB and urothelial inflammation, urinary NGF would be reduced following antibiotic therapy.

METHODS

Women with overactive bladder and urodynamic diagnosis of detrusor overactivity who were refractory to anticholinergics, and had histological evidence of urothelial inflammation were treated with a 6-week course of rotating antibiotics. Urinary NGF was measured by ELISA before and after treatment. Three-day bladder diaries, the Patients' Perception of Intensity of Urgency Scale, the King's Health Questionnaire and the Patients' Perception of Bladder Condition questionnaire were used to assess subjective and objective outcomes of therapy.

RESULTS

Thirty-nine women with refractory DO were recruited. The NGF levels decreased significantly after antibiotic therapy (Wilcoxon signed rank test; p = 0.015). There were significant improvements in daytime frequency, nocturia and urgency (p < 0.05), and 74 % of women reported improvement in perception of their bladder condition.

CONCLUSIONS

Urinary NGF is responsive to antibiotic therapy. Women with refractory overactive bladder and elevated NGF may benefit from antibiotic treatment.

Nerve growth factor: from the early discoveries to the potential clinical use

The physiological role of the neurotrophin nerve growth factor (NGF) has been characterized, since its discovery in the 1950s, first in the sensory and autonomic nervous system, then in central nervous, endocrine and immune systems. NGF plays its trophic role both during development and in adulthood, ensuring the maintenance of phenotypic and functional characteristic of several populations of neurons as well as immune cells. From a translational standpoint, the action of NGF on cholinergic neurons of the basal forebrain and on sensory neurons in dorsal root ganglia first gained researcher's attention, in view of possible clinical use in Alzheimer's disease patients and in peripheral neuropathies respectively. The translational and clinical research on NGF have, since then, enlarged the spectrum of diseases that could benefit from NGF treatment, at the same time highlighting possible limitations in the use of the neurotrophin as a drug. In this review we give a comprehensive account for almost all of the clinical trials attempted until now by using NGF. A perspective on future development for translational research on NGF is also discussed, in view of recent proposals for innovative delivery strategies and/or for additional pathologies to be treated, such as ocular and skin diseases, gliomas, traumatic brain injuries, vascular and immune diseases.

Potential role of neurogenic inflammatory factors in the pathogenesis of vitiligo

BACKGROUND

Vitiligo is a highly complex multifactorial condition of the skin that has an unclear mechanism of pathogenesis.

OBJECTIVE

This review summarizes the role of various neurogenic inflammatory factors significantly upregulated in vitiligo.

METHODS

A literature review was conducted of all pertinent data regarding neuropeptides that are altered in vitiligo and their possible role in the destruction of melanocytes.

RESULTS

The close associations between the skin, immune system, and nervous system, along with specific changes demonstrated in vitiligo patients, support a pathogenic mechanism of vitiligo that involves neuroimmunologic factors, the release of which can be governed by mental stress.

CONCLUSION

Neuropeptides and nerve growth factors are critical regulators of emotional response and may precipitate the onset and development of vitiligo in certain predisposed individuals. More studies are required to investigate whether a direct link exists between genetics, mental stress, and neurogenic factors in vitiligo.