ABSTRACT
Multiple sclerosis (MS) is a complex autoimmune disease with multiple players. In particular, peripheral (myelin-reactive CD4+ T lymphocytes) and central immune cells (microglia) are involved in the neuroinflammatory process and are found in MS brain lesions. New nanotechnological approaches that can cross the blood-brain barrier and specifically target the key players in the disease using biocompatible nanomaterials with low immunoreactivity represent an important challenge. To this end, nanoparticles and nanovesicles have been studied to induce immune tolerance to a wide range of myelin-derived antigens as potential approaches against MS. To this aim, we extracted myelin from bovine brain and produced myelin-based nanovesicles (MyVes) by nanoprecipitation. MyVes have a diameter of about 100 nm, negative zeta potential and contain the typical proteins of the myelin sheath. The results showed that MyVes are not cytotoxic, are hemocompatibile and do not induce an inflammatory response. In vitro experiments showed that MyVes are specifically taken up by microglial cells and are able to induce the expression of the anti-inflammatory cytokine IL-4. In addition, we have used biodistribution experiments to show that MyVes are able to reach the brain after intranasal administration. Finally, MyVes induced the production of the anti-inflammatory cytokines IL-10 and IL-4 in peripheral blood mononuclear cells isolated from MS patients. Taken together, these data provide proof of concept that MyVes may represent a safe nanosystem capable of promoting anti-inflammatory effects by modulating both central and peripheral immune cells to treat neuroinflammation in MS. STATEMENT OF SIGNIFICANCE: Recently, nanoparticles and nanovesicles have been investigated as potential approaches for the treatment of neurodegenerative diseases. We propose the use of myelin nanovesicles (MyVes) as a potential application to counteract neuroinflammation in multiple sclerosis (MS). Approximately 2.8 million people worldwide are estimated to live with MS. It is an autoimmune disease directed toward various myelin-derived antigens. Both peripheral immune cells (lymphocytes) and central immune cells (microglia) actively contribute to MS brain lesions. MyVes, due to their myelin nature, specific characteristics (size, zeta potential, and presence of myelin proteins), biocompatibility, and ability to cross the blood-brain barrier, could represent the first nanosystem capable of promoting anti-inflammatory actions by modulating both central and peripheral immune cells to treat neuroinflammation in MS.
ABSTRACT
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.
ABSTRACT
BACKGROUND: Severe traumatic brain injury (TBI) is one of the most dramatic events in pediatric age and, despite advanced neuro-intensive care, the survival rate of these patients remains low. Children suffering from severe TBI show long-term sequelae, more pronounced in behavioral, neurological and neuropsychological functions leading to, in the most severe cases, an unresponsive wakefulness syndrome (UWS). Currently, no effective treatments can restore neuronal loss or produce significant improvement in these patients. In experimental animal models, human- recombinant Nerve Growth Factor (hr-NGF) promotes neural recovery supporting neuronal growth, differentiation and survival of brain cells and up-regulating the neurogenesis-associated processes. Only a few studies reported the efficacy of intranasal hr-NGF administration in children with post- traumatic UWS. METHODS: Children with the diagnosis of post-traumatic UWS were enrolled. These patients underwent a treatment with intranasal hr-NGF administration, at a total dose of 50 gamma/kg, three times a day for 7 consecutive days. The treatment schedule was performed for 4 cycles, at one month distance each. Neuroradiogical evaluation by Positron Emission Tomography scan (PET), Single Photon Emission Computed Tomography (SPECT), Electroencephalography (EEG), and Power Spectral Density (PSD) was determined before the treatment and one month after the end. Neurological assessment was also deepened by using modified Ashworth Scale, Gross Motor Function Measure, and Disability Rating Scale. RESULTS: Three children with post-traumatic UWS were treated. hr-NGF administration improved functional (PET and SPECT) and electrophysiological (EEG and PSD) assessment. Also clinical conditions improved, mainly for the reduction of spasticity and with the acquisition of voluntary movements, facial mimicry, attention and verbal comprehension, ability to cry, cough reflex, oral motility, and feeding capacity, with a significant improvement of their neurological scores. No side effects were reported. CONCLUSION: These promising results and the ease of administration of this treatment make it worthwhile to be investigated further, mainly in the early stages from severe TBI and in patients with better baseline neurological conditions, to explore more thoroughly the benefits of this new approach on neuronal function recovery after traumatic brain damage.
Subject(s)
Nerve Growth Factor , Wakefulness , Animals , Humans , Child , Nerve Growth Factor/therapeutic use , Nerve Growth Factor/metabolism , Wakefulness/physiology , Brain , Electroencephalography , Administration, IntranasalABSTRACT
BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is one of the most dramatic events in pediatric age and, despite advanced neurointensive care, the survival rate remains low. Currently, no effective treatments can restore neuronal loss or produce significant improvement in these patients. Nerve Growth Factor (NGF) is a neurotrophin potentially able to counteract many of the deleterious effects triggered by OHCA. Transcranial Direct Current Stimulation (tDCS) has been reported to be neuroprotective in many neurological diseases, such as motor deficit and cognitive impairment. Children with the diagnosis of chronic vegetative state after OHCA were enrolled. These patients underwent a combined treatment of intranasal administration of human recombinant NGF (hr-NGF), at a total dose of 50 gamma/kg, and tDCS, in which current intensity was increased from zero to 2 mA from the first 5 s of stimulation and maintained constant for 20 min. The treatment schedule was performed twice, at one month distance each. Neuroradiogical evaluation with Positron Emission Tomography scan (PET), Single Photon Emission Computed Tomography (SPECT), Electroencephalography (EEG) and Power Spectral Density of the brain (PSD) was determined before the treatment and one month after the end. Neurological assessment was deepened by using modified Ashworth Scale, Gross Motor Function Measure, and Disability Rating Scale. RESULTS: Three children with a chronic vegetative state secondary to OHCA were treated. The combined treatment with hr-NGF and tDCS improved functional (PET and SPECT) and electrophysiological (EEG and PSD) assessment. Also clinical conditions improved, mainly for the reduction of spasticity and with the acquisition of voluntary finger movements, improved facial mimicry and reaction to painful stimuli. No side effects were reported. CONCLUSIONS: These promising preliminary results and the ease of administration of this treatment make it worthwhile to be investigated further, mainly in the early stages from OHCA and in patients with better baseline neurological conditions, in order to explore more thoroughly the benefits of this new approach on neuronal function recovery after OHCA.
Subject(s)
Out-of-Hospital Cardiac Arrest , Transcranial Direct Current Stimulation , Humans , Child , Out-of-Hospital Cardiac Arrest/therapy , Persistent Vegetative State , Transcranial Direct Current Stimulation/methods , Nerve Growth Factor/therapeutic use , BrainABSTRACT
BACKGROUND AND PURPOSE: Traumatic brain injury (TBI) comprises a primary injury directly induced by impact, which progresses into a secondary injury leading to neuroinflammation, reactive astrogliosis, and cognitive and motor damage. To date, treatment of TBI consists solely of palliative therapies that do not prevent and/or limit the outcomes of secondary damage and only stabilize the deficits. The neurotrophin, nerve growth factor (NGF), delivered to the brain parenchyma following intranasal application, could be a useful means of limiting or improving the outcomes of the secondary injury, as suggested by pre-clinical and clinical data. EXPERIMENTAL APPROACH: We evaluated the effect of acute intranasal treatment of young (20-postnatal day) rats, with NGF in a TBI model (weight drop/close head), aggravated by hypoxic complications. Immediately after the trauma, rats were intranasally treated with human recombinant NGF (50 µg·kg-1 ), and motor behavioural test, morphometric and biochemical assays were carried out 24 h later. KEY RESULTS: Acute intranasal NGF prevented the onset of TBI-induced motor disabilities, and decreased reactive astrogliosis, microglial activation and IL-1ß content, which after TBI develops to the same extent in the impact zone and the hypothalamus. CONCLUSION AND IMPLICATIONS: Intranasal application of NGF was effective in decreasing the motor dysfunction and neuroinflammation in the brain of young rats in our model of TBI. This work forms an initial pre-clinical evaluation of the potential of early intranasal NGF treatment in preventing and limiting the disabling outcomes of TBI, a clinical condition that remains one of the unsolved problems of paediatric neurology.
Subject(s)
Brain Injuries, Traumatic , Brain Injuries , Child , Rats , Humans , Animals , Nerve Growth Factor , Neuroinflammatory Diseases , Gliosis , Brain Injuries, Traumatic/drug therapy , Brain Injuries, Traumatic/metabolism , Brain Injuries/drug therapy , Inflammation , Disease Models, AnimalABSTRACT
Background: Whole-body electromyostimulation (WB-EMS) was never previously applied to Parkinson's disease (PD) patients. This randomized controlled study aimed to find the most effective and safe WB-EMS training protocol for this population. Methods: Twenty-four subjects (age: 72.13 ± 6.20 years), were randomly assigned to three groups: a high-frequency WB-EMS strength training group (HFG) (rectangular stimulation at 85 Hz, 350 µs, 4 s stimulation/4 s rest), a low-frequency WB-EMS aerobic training group (LFG) (rectangular stimulation 7 Hz, 350 µs, with a continuous pulse duration), and an inactive control group (CG). Participants of the two experimental groups underwent 24 controlled WB-EMS training sessions, with a duration of 20 min each, during 12-week intervention. Serum growth factors (BDNF, FGF-21, NGF and proNGF), α-synuclein, physical performance and Parkinson's Disease Fatigue Scale (PFS-16) responses were analyzed to evaluate the pre-post variation and differences among groups. Results: Significant interactions of Time*Groups were detected for BDNF (Time*Groups p = 0.024; Time*CG, b = -628, IC95% = -1,082/-174, p = 0.008), FGF-21 (Time*Groups p = 0.009; Time*LFG b = 1,346, IC95% = 423/2268, p = 0.005), and α-synuclein (Time*Groups p = 0.019; Time*LFG b = -1,572, IC95% = -2,952/-192, p = 0.026). Post hoc analyses and comparisons of ΔS (post-pre), performed independently for each group, showed that LFG increased serum BDNF levels (+ 203 pg/ml) and decreased α-synuclein levels (-1,703 pg/ml), while HFG showed the opposite effects (BDNF: -500 pg/ml; α-synuclein: + 1,413 pg/ml). CG showed a significant BDNF reduction over time. Both LFG and HFG showed significant improvements in several physical performance outcomes and the LFG showed better results than HFG. Concerning PFS-16, significant differences over time (b = -0.4, IC95% = -0.8/-0.0, p = 0.046) and among groups (among all groups p < 0.001) were found, and the LFG exhibited better results than the HFG (b = -1.0, IC95% = -1.3/-0.7, p < 0.001), and CG (b = -1.7, IC95% = -2.0/-1.4, p < 0.001) with this last one that worsened over time. Conclusion: LFG training was the best choice for improving or maintaining physical performance, fatigue perception and variation in serum biomarkers. Clinical trial registration: https://www.clinicaltrials.gov/ct2/show/NCT04878679, identifier NCT04878679.
ABSTRACT
Traumatic brain injury is one of the main causes of mortality and disability worldwide. Traumatic brain injury is characterized by a primary injury directly induced by the impact, which progresses into a secondary injury that leads to cellular and metabolic damages, starting in the first few hours and days after primary mechanical injury. To date, traumatic brain injury is not targetable by therapies aimed at preventing and/or limiting the outcomes of secondary damage but only by palliative therapies. Nerve growth factor is a neurotrophin targeting neuronal and non-neuronal cells, potentially useful in preventing/limiting the outcomes of secondary damage in traumatic brain injury. This potential has further increased in the last two decades since the possibility of reaching neurotrophin targets in the brain through its intranasal delivery has been exploited. Indeed, molecules intranasally delivered to the brain parenchyma may easily bypass the blood-brain barrier and reach their therapeutic targets in the brain, with favorable kinetics, dynamics, and safety profile. In the first part of this review, we aimed to report the traumatic brain injury-induced dysfunctional mechanisms that may benefit from nerve growth factor treatment. In the second part, we then exposed the experimental evidence relating to the action of nerve growth factor (both in vitro and in vivo, after administration routes other than intranasal) on some of these mechanisms. In the last part of the work, we, therefore, discussed the few manuscripts that analyze the effects of treatment with nerve growth factor, intranasally delivered to the brain parenchyma, on the outcomes of traumatic brain injury.
Subject(s)
Air Pollution , COVID-19 , Humans , COVID-19/epidemiology , Pandemics , Air Pollution/adverse effectsABSTRACT
We have recently provided new evidence for a role of p75NTR receptor and its preferential ligand proNGF in amplifying inflammatory responses in synovial mononuclear cells of chronic arthritis patients. In the present study, to better investigate how activation of the p75NTR/proNGF axis impacts synovial inflammation, we have studied the effects of proNGF on fibroblast-like synoviocytes (FLS), which play a central role in modulating local immune responses and in activating pro-inflammatory pathways. Using single cell RNA sequencing in synovial tissues from active and treatment-naïve rheumatoid arthritis (RA) patients, we demonstrated that p75NTR and sortilin, which form a high affinity receptor complex for proNGF, are highly expressed in PRG4pos lining and THY1posCOL1A1pos sublining fibroblast clusters in RA synovia but decreased in RA patients in sustained clinical remission. In ex vivo experiments we found that FLS from rheumatoid arthritis patients (RA-FLS) retained in vitro a markedly higher expression of p75NTR and sortilin than FLS from osteoarthritis patients (OA-FLS). Inflammatory stimuli further up-regulated p75NTR expression and induced endogenous production of proNGF in RA-FLS, leading to an autocrine activation of the proNGF/p75NTR pathway that results in an increased release of pro-inflammatory cytokines. Our data on the inhibition of p75NTR receptor, which reduced the release of IL-1ß, IL-6 and TNF-α, further confirmed the key role of p75NTR activation in regulating inflammatory cytokine production. In a set of ex vivo experiments, we used RA-FLS and cultured them in the presence of synovial fluids obtained from arthritis patients that, as we demonstrated, are characterized by a high concentration of proNGF. Our data show that the high levels of proNGF present in inflamed synovial fluids induced pro-inflammatory cytokine production by RA-FLS. The blocking of NGF binding to p75NTR using specific inhibitors led instead to the disruption of this pro-inflammatory loop, reducing activation of the p38 and JNK intracellular pathways and decreasing inflammatory cytokine production. Overall, our data demonstrate that an active proNGF/p75NTR axis promotes pro-inflammatory responses in synovial fibroblasts, thereby contributing to chronic synovial inflammation, and point to the possible use of p75NTR inhibitors as a novel therapeutic approach in chronic arthritis.
Subject(s)
Arthritis, Rheumatoid , Osteoarthritis , Carrier Proteins/metabolism , Cells, Cultured , Cytokines/metabolism , Fibroblasts/metabolism , Humans , Inflammation/metabolism , Nerve Growth Factor/metabolism , Nerve Tissue Proteins , Protein Precursors , Receptors, Nerve Growth FactorABSTRACT
The high incidence and increased mortality of COVID-19 make Italy among the most impacted countries by SARS-CoV-2 outbreak. In the beginning of the pandemic, Northern regions accounted for 40% of cases and 45% of deaths from COVID-19 in Italy. Several factors have been suggested to explain the higher incidence and excess mortality from COVID-19 in these regions. It is noticed that Northern Italian regions, and particularly the cities in Po Valley, are the areas with the highest air pollution due to commercial vehicle traffic, industry and a stagnant meteorological condition, with one of the highest levels in Italy and Europe of fine particulate matter 2.5 micron or smaller in size (PM2.5). PM2.5, the major environmental pollutant deriving mainly by factory and automobile exhaust emissions and coal combustion, increases the expression of angiotensin-converting enzyme 2, the epithelial cell entry receptor for SARS-CoV-2, and thus increase the susceptibility to this virus. The epithelial barrier hypothesis proposes that many diverse diseases may rise from the disruption of epithelial barrier of skin, respiratory tract and gastrointestinal system, including allergic diseases, metabolic and autoimmune diseases, and chronic neuropsychiatric conditions. There is evidence of a close correlation between air pollution and airway epithelial barrier dysfunction. Air pollution, causing lung epithelial barrier dysfunction, may contribute to local chronic inflammation, microbiome dysbiosis and impaired antiviral immune response against SARS-CoV-2, all of which contribute to the high incidence and excess mortality from COVID-19. In addition, air pollution and epithelial barrier dysfunction contribute also to the higher prevalence of several comorbidities of COVID-19, such as diabetes, chronic obstructive pulmonary disease and obesity, which have been identified as risk factors for mortality of COVID-19. In this article, on the basis of epidemiological and environmental monitoring data in Northern Italy, it is suggested that epithelial barrier hypothesis may help to understand the excess burden and mortality from COVID-19.
Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Air Pollutants/analysis , Air Pollution/adverse effects , Air Pollution/analysis , Humans , Incidence , Italy/epidemiology , Pandemics , Particulate Matter/adverse effects , SARS-CoV-2ABSTRACT
Since the 1980s, the development of a pharmacology based on nerve growth factor (NGF) has been postulated for the therapy of Alzheimer's disease (AD). This hypothesis was based on the rescuing effect of the neurotrophin on the cholinergic phenotype of the basal forebrain neurons, primarily compromised during the development of AD. Subsequently, the use of NGF was put forward to treat a broader spectrum of neurological conditions affecting the central nervous system, such as Parkinson's disease, degenerative retinopathies, severe brain traumas and neurodevelopmental dysfunctions. While supported by solid rational assumptions, the progress of a pharmacology founded on these hypotheses has been hampered by the difficulty of conveying NGF towards the brain parenchyma without resorting to invasive and risky delivery methods. At the end of the last century, it was shown that NGF administered intranasally to the olfactory epithelium was able to spread into the brain parenchyma. Notably, after such delivery, pharmacologically relevant concentration of exogenous NGF was found in brain areas located at considerable distances from the injection site along the rostral-caudal axis. These observations paved the way for preclinical characterization and clinical trials on the efficacy of intranasal NGF for the treatment of neurodegenerative diseases and of the consequences of brain trauma. In this review, a summary of the preclinical and clinical studies published to date will be attempted, as well as a discussion about the mechanisms underlying the efficacy and the possible development of the pharmacology based on intranasal conveyance of NGF to the brain.
ABSTRACT
Parkinson's disease (PD) patients lead a sedentary lifestyle, being unable or unwilling to exercise conventionally, due to physical and mental limitations. The aim of this study was to assess the acute effects of a single session of whole-body electromyostimulation (WB-EMS) on the physical performances and serum levels of the neurotrophic factors in PD patients. Ten subjects (aged 72.60 ± 6.82) underwent 20 min of physical activity with superimposed WB-EMS and, after four weeks, the same protocol with no WB-EMS. WB-EMS was conducted with intermittent stimulation, with 4 s WB-EMS/4 s rest, at 85 Hz, 350 µs. A physical fitness assessment and blood samples collection, to evaluate neurotrophic factors' levels (BDNF, FGF21, proNGF, mNGF), were collected before and after the intervention. The RM-ANOVA showed significant improvements in sit-to-stand (p < 0.01), arm curl (p < 0.01), handgrip (p < 0.01) and soda pop test (p < 0.01) after the WB-EMS intervention. Higher proNFG serum levels were observed in the WB-EMS condition compared to the no WB-EMS after 60 min post-intervention (p = 0.0163). The effect of WB-EMS confirmed the electrostimulation ability to modulate the proNGF quantity. The positive impact of the WB-EMS protocol on physical functioning, and eye-hand coordination, makes this intervention a promising strategy to improve motor and non-motor symptoms in PD patients.
Subject(s)
Electric Stimulation Therapy , Parkinson Disease , Exercise , Hand Strength , Humans , Muscle Strength , Parkinson Disease/therapyABSTRACT
INTRODUCTION: Ischemic stroke is an important cause of death and long-term morbidity in children. Viral respiratory infections are emerging as important risk factors for ischemic stroke in this age group of patients. Direct action of virus against cerebral vessels, autoimmune reactivity, and an increased production of cytokines have all been advocated as main factors in determining ischemic stroke. CASE REPORT: We report the case of an EBV-induced ischemic stroke in a caucasian 2 year-old female. The cerebrospinal fluid samples showed positivity of polymerase chain reaction for EBV infection, also confirmed by pharyngeal swab culture. Increased levels of interleukin 6 and interleukin 1b were also detected in the cerebrospinal fluid. Discussion: EBV infection has been identified as an important cause of neurological involvement in children. Findings of increased levels of interleukin 6 and interleukin 1b in the cerebrospinal fluid of the child with EBV induced-ischemic stroke seems to validate the role of pro-inflammatory cytokines as crucial mediators of cerebral thrombus formation. Conclusions: We believe that this report can be useful to clarify some pathophysiological mechanisms related to ischemic stroke related to Epstein-Barr Virus (EBV) infection in children.
Subject(s)
Epstein-Barr Virus Infections , Stroke , Virus Diseases , Child, Preschool , Epstein-Barr Virus Infections/complications , Female , Herpesvirus 4, Human/genetics , Humans , Polymerase Chain Reaction , Stroke/etiologyABSTRACT
Neurotrophins are a family of proteins that support neuronal proliferation, survival, and differentiation in the central and peripheral nervous systems, and are regulators of neuronal plasticity. Nerve growth factor is one of the best-described neurotrophins and has advanced to clinical trials for treatment of ocular and brain diseases due to its trophic and regenerative properties. Prior trials over the past few decades have produced conflicting results, which have principally been ascribed to adverse effects of systemic nerve growth factor administration, together with poor penetrance of the blood-brain barrier that impairs drug delivery. Contrastingly, recent studies have revealed that topical ocular and intranasal nerve growth factor administration are safe and effective, suggesting that topical nerve growth factor delivery is a potential alternative to both systemic and invasive intracerebral delivery. The therapeutic effects of local nerve growth factor delivery have been extensively investigated for different ophthalmic diseases, including neurotrophic keratitis, glaucoma, retinitis pigmentosa, and dry eye disease. Further, promising pharmacologic effects were reported in an optic glioma model, which indicated that topically administered nerve growth factor diffused far beyond where it was topically applied. These findings support the therapeutic potential of delivering topical nerve growth factor preparations intranasally for acquired and degenerative brain disorders. Preliminary clinical findings in both traumatic and non-traumatic acquired brain injuries are encouraging, especially in pediatric patients, and clinical trials are ongoing. The present review will focus on the therapeutic effects of both ocular and intranasal nerve growth factor delivery for diseases of the brain and eye.
ABSTRACT
Carbon nanotubes (CNTs) are currently under active investigation for their use in several biomedical applications, especially in neurological diseases and nervous system injury due to their electrochemical properties. Nowadays, no CNT-based therapeutic products for internal use appear to be close to the market, due to the still limited knowledge on their fate after delivery to living organisms and, in particular, on their toxicological profile. The purpose of the present work was to address the distribution in the brain parenchyma of two intranasally delivered MWCNTs (MWCNTs 1 and a-MWCNTs 2), different from each other, the first being non electroconductive while the second results in being electroconductive. After intranasal delivery, the presence of CNTs was investigated in several brain areas, discriminating the specific cell types involved in the CNT uptake. We also aimed to verify the neuroprotective potential of the two types of CNTs, delivering them in rats affected by early diabetic encephalopathy and analysing the modulation of nerve growth factor metabolism and the effects of CNTs on the neuronal and glial phenotypes. Our findings showed that both CNT types, when intranasally delivered, reached numerous brain areas and, in particular, the limbic area that plays a crucial role in the development and progression of major neurodegenerative diseases. Furthermore, we demonstrated that electroconductive MWCNTs were able to exert neuroprotective effects through the modulation of a key neurotrophic factor and probably the improvement of neurodegeneration-related gliosis.
ABSTRACT
The ongoing COVID-19 pandemic still requires fast and effective efforts from all fronts, including epidemiology, clinical practice, molecular medicine, and pharmacology. A comprehensive molecular framework of the disease is needed to better understand its pathological mechanisms, and to design successful treatments able to slow down and stop the impressive pace of the outbreak and harsh clinical symptomatology, possibly via the use of readily available, off-the-shelf drugs. This work engages in providing a wider picture of the human molecular landscape of the SARS-CoV-2 infection via a network medicine approach as the ground for a drug repurposing strategy. Grounding on prior knowledge such as experimentally validated host proteins known to be viral interactors, tissue-specific gene expression data, and using network analysis techniques such as network propagation and connectivity significance, the host molecular reaction network to the viral invasion is explored and exploited to infer and prioritize candidate target genes, and finally to propose drugs to be repurposed for the treatment of COVID-19. Ranks of potential target genes have been obtained for coherent groups of tissues/organs, potential and distinct sites of interaction between the virus and the organism. The normalization and the aggregation of the different scores allowed to define a preliminary, restricted list of genes candidates as pharmacological targets for drug repurposing, with the aim of contrasting different phases of the virus infection and viral replication cycle.
ABSTRACT
The precursor of Nerve Growth Factor (proNGF) is the predominant form of NGF in the brain, where its tissue levels are increased in neurodegenerative diseases. proNGF exists in two main splicing variants, the long proNGF-A and the short proNGF-B. We demonstrated that proNGF-B is selectively increased in the hippocampus of rats affected by early diabetic encephalopathy and that native, purified proNGFs elicit different responses when used to stimulate PC12 cells. Therefore, the evaluation of the proNGF-B/proNGF-A ratio may be of important diagnostic and prognostic value in pathologies characterized by dysfunctions of NGF system. To date there is not clear pharmacological characterization of the different proNGFs variants, due to the lack of a proper recombinant proNGF-A. Using a bioinformatics approach, we predicted aminoacid sites involved in proNGF-A intracellular cleavage/conversion into proNGF-B, we cloned and expressed non-cleavable proNGF-A in HeLa cells and pursued a first characterization of their secretion modalities. Finally, we studied the biological effects of different proNGF-A mutants, stimulating PC12 cells with conditioned media from transfected HeLa cells. Based on our results, we propose the A73Y mutation as essential to obtaining an intact proNGF-A, limiting its conversion to proNGF-B. proNGF-A A73Y is probably released in an activity dependent manner and, when supplied to PC12 cells, shows a moderate differentiative capacity opposed to high neuroprotective potential. This preliminary study lays the foundation for future research aimed at uncovering the selective biological activities of proNGF-A and proNGF-B, and at developing pharmacological treatments that target the unbalance of proNGF system, induced by neurodegeneration.
Subject(s)
Computational Biology/methods , Genetic Variation/genetics , Nerve Growth Factor/genetics , Protein Precursors/genetics , Recombinant Proteins/genetics , Animals , Base Sequence , HeLa Cells , Humans , Nerve Growth Factor/chemistry , PC12 Cells , Protein Precursors/chemistry , Rats , Recombinant Proteins/chemistryABSTRACT
Pro-nerve growth factor (proNGF) is the predominant form of NGF in the brain and its levels increase in neurodegenerative diseases. The balance between NGF receptors may explain the contradictory biological activities of proNGF. However, the specific role of the two main proNGF variants is mostly unexplored. proNGF-A is prevalently expressed in healthy brain, while proNGF-B content increases in the neuro-degenerating brain. Recently we have investigated in vitro the biological action of native mouse proNGF variants. To gain further insights into the specific functions of the two proNGFs, here we intranasally delivered mouse-derived proNGF-A and proNGF-B to the brain parenchyma of healthy and diabetic rats, the latter characterized by dysfunction in spatial learning and memory, in the septo-hippocampal circuitry and by relative increase in proNGF-B hippocampal levels. Exogenous proNGF-B induces depression of hippocampal DG-LTP and impairment of hippocampal neurogenesis in healthy animals, with concomitant decrease in basal forebrain cholinergic neurons and cholinergic fibers projecting to the hippocampus. proNGF-A, while ineffective in healthy animals, rescues the diabetes-induced impairment in DG-LTP and hippocampal neurogenesis, promoting the concomitant recovery of the basal forebrain cholinergic phenotype. Our experimental evidences suggest that the balance between different proNGFs may influence the development and progression of neurodegenerative diseases.
Subject(s)
Diabetes Mellitus, Experimental/metabolism , Drug Delivery Systems/methods , Hippocampus/metabolism , Nerve Growth Factor/administration & dosage , Nerve Net/metabolism , Protein Precursors/administration & dosage , Septum of Brain/metabolism , Administration, Intranasal , Animals , Female , Hippocampus/drug effects , Mice , Nerve Net/drug effects , Organ Culture Techniques , Rats , Rats, Sprague-Dawley , Septum of Brain/drug effectsABSTRACT
BACKGROUND AND LIMITATIONS: Impaired wound healing (WH) and chronic inflammation are hallmarks of non-communicable diseases (NCDs). However, despite WH being a recognized player in NCDs, mainstream therapies focus on (un)targeted damping of the inflammatory response, leaving WH largely unaddressed, owing to three main factors. The first is the complexity of the pathway that links inflammation and wound healing; the second is the dual nature, local and systemic, of WH; and the third is the limited acknowledgement of genetic and contingent causes that disrupt physiologic progression of WH. PROPOSED APPROACH: Here, in the frame of Predictive, Preventive, and Personalized Medicine (PPPM), we integrate and revisit current literature to offer a novel systemic view on the cues that can impact on the fate (acute or chronic inflammation) of WH, beyond the compartmentalization of medical disciplines and with the support of advanced computational biology. CONCLUSIONS: This shall open to a broader understanding of the causes for WH going awry, offering new operational criteria for patients' stratification (prediction and personalization). While this may also offer improved options for targeted prevention, we will envisage new therapeutic strategies to reboot and/or boost WH, to enable its progression across its physiological phases, the first of which is a transient acute inflammatory response versus the chronic low-grade inflammation characteristic of NCDs.