Nerve Growth Factor: Early Studies and Recent Clinical Trials

Topical Nerve Growth Factor (NGF) restores electrophysiological alterations in the Ins2Akita mouse model of diabetic retinopathy

People suffering from diabetes mellitus commonly have to face diabetic retinopathy (DR), an eye disease characterized by early retinal neurodegeneration and microvascular damage, progressively leading to sight loss. The Ins2Akita (Akita) diabetic mouse presents the characteristics of DR and experimental drugs can be tested on this model to check their efficacy before going to the clinic. Topical administration of Nerve Growth Factor (NGF) has been recently demonstrated to prevent DR in the Akita mouse, reverting the thinning of retinal layers and protecting the retinal ganglion cells (RGCs) from death. In this study, we characterize the effects of topical NGF on neuroretina function, quantified with the electroretinogram (ERG). In particular, we show that NGF can ameliorate RGC conduction in the retina of Akita mice, which correlates with a recovery of retinal nerve fiber plus ganglion cell layer (RNFL-GCL) structure. Overall, our preclinical results highlight that topical administration of NGF could be a promising therapeutic approach for DR, being capable of exerting a beneficial impact on retinal functionality.

Biological markers of sex-based differences in major depressive disorder and in antidepressant response

Major depressive disorder (MDD) presents different clinical features in women and men, with women being more affected and responding differently to antidepressant treatment. Specific molecular mechanisms underlying these differences are not well studied and this narrative review aims at providing an overview of the neurobiological features underlying sex-differences in biological systems involved in MDD pathophysiology and response to antidepressant treatment, focusing on human studies. The majority of the reviewed studies were performed through candidate gene approaches, focusing on biological systems involved in MDD pathophysiology, including the stress response, inflammatory and immune, monoaminergic, neurotrophic, gamma-aminobutyric acid and glutamatergic, and oxytocin systems. The influence of the endocrine system and sex-specific hormone effects are also discussed. Genome, epigenome and transcriptome-wide approaches are less frequently performed and most of these studies do not focus on sex-specific alterations, revealing a paucity of omics studies directed to unravel sex-based differences in MDD. Few studies about sex-related differences in antidepressant treatment response have been conducted, mostly involving the inflammatory system, with less evidence on the monoaminergic system and sparse evidence in omics approaches. Our review covers the importance of accounting for sex-differences in research, optimizing patient stratification for a more precise diagnostic and individualized treatment for women and men.

Pathomechanism of Pruritus in Psoriasis and Atopic Dermatitis: Novel Approaches, Similarities and Differences

Pruritus is defined as an unpleasant sensation that elicits a desire to scratch. Nearly a third of the world's population may suffer from pruritus during their lifetime. This symptom is widely observed in numerous inflammatory skin diseases-e.g., approximately 70-90% of patients with psoriasis and almost every patient with atopic dermatitis suffer from pruritus. Although the pathogenesis of atopic dermatitis and psoriasis is different, the complex intricacies between several biochemical mediators, enzymes, and pathways seem to play a crucial role in both conditions. Despite the high prevalence of pruritus in the general population, the pathogenesis of this symptom in various conditions remains elusive. This review aims to summarize current knowledge about the pathogenesis of pruritus in psoriasis and atopic dermatitis. Each molecule involved in the pruritic pathway would merit a separate chapter or even an entire book, however, in the current review we have concentrated on some reports which we found crucial in the understanding of pruritus. However, the pathomechanism of pruritus is an extremely complex and intricate process. Moreover, many of these signaling pathways are currently undergoing detailed analysis or are still unexplained. As a result, it is currently difficult to take an objective view of how far we have come in elucidating the pathogenesis of pruritus in the described diseases. Nevertheless, considerable progress has been made in recent years.

Enhancement of neural regeneration as a therapeutic strategy for Alzheimer's disease (Review)

Alzheimer's disease (AD), the most common cause of dementia worldwide, has gradually become a global health concern for society and individuals with the process of global ageing. Although extensive research has been carried out on AD, the etiology and pathological mechanism of the disease are still unclear, and there is no specific drug to cure or delay AD progression. The exploration of enhancing nerve regeneration in AD has gradually attracted increasing attention. In the current review, the existing therapeutic strategies were summarized to induce nerve regeneration which can increase the number of neurons, and improve the survival of neurons, the plasticity of synapses and synaptic activity. The strategies include increasing neurotrophic expression (such as brain-derived neurotrophic factor and nerve growth factor), inhibiting acetylcholinesterase (such as donepezil, tacrine, rivastigmine and galanthamine), elevating histone deacetylase levels (such as RGFP-966, Tasquinimod, CM-414 and 44B), stimulating the brain by physiotherapy (such as near-infrared light, repetitive transcranial magnetic stimulation, and transcranial direct current stimulation) and transplanting exogenous neural stem cells. However, further evaluations need to be performed to determine the optimal treatment. The present study reviews recent interventions for enhancing adult neurogenesis and attempts to elucidate their mechanisms of action, which may provide a theoretical basis for inducing nerve regeneration to fight against AD.

Efficacy of metformin in prevention of paclitaxel-induced peripheral neuropathy in breast cancer patients: a randomized controlled trial

Background: Paclitaxel-induced peripheral neuropathy (PN) is a serious clinical problem with no approved drug for prevention. This study aimed to examine the neuroprotective effect of metformin against paclitaxel-induced PN in breast cancer patients. Methods: Patients with confirmed breast cancer diagnosis who were planned to receive paclitaxel were randomized to receive either metformin or placebo. Both groups received the standard chemotherapy protocol for breast cancer. Patients started metformin/placebo 1 week before paclitaxel initiation and continued study interventions thereafter for nine consecutive weeks. The primary outcome was the incidence of development of grade two or more paclitaxel-induced sensory PN. The PN was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE). Patients' quality of life (QoL) was assessed by the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACTGOG-Ntx) subscale. Pain severity was measured by the Brief Pain Inventory Short Form (BPI-SF). Serum levels of nerve growth factor (NGF) and neurotensin (NT) were measured at baseline and at the end paclitaxel treatment. Results: A total of 73 patients (36 in the metformin arm and 37 in the control arm) were evaluated. The cumulative incidence of development of grade two or more PN was significantly lower in the metformin arm (14 (38.9%) than the control arm (28 (75.7%); p = 0.001). At the end of paclitaxel treatment, patients' QoL was significantly better in the metformin arm [median (IQR) FACTGOG-Ntx subscale of (24.0 (20.5-26.5)] compared to the control arm (21.0 (18.0-24.0); p = 0.003). The metformin arm showed lower "average" and "worst" pain scores than those detected in the control arm. At the end of the paclitaxel treatment, there was a significant difference in the median serum NGF levels between the two arms, favoring metformin (p < 0.05), while NT serum levels were deemed comparable between the two study arms (p = 0.09). Conclusion: The use of metformin in breast cancer patients offered a marked protection against paclitaxel-induced PN, which translated to better patient QoL. Clinical Trial Registration: https://classic.clinicaltrials.gov/ct2/show/NCT05351021, identifier NCT05351021.

Chronic resveratrol administration reduces oxidative stress and brain cell loss and improves memory of recognition in old rats

The cognitive functions of people over 60 years of age have been diminished, due to the structural and functional changes that the brain has during aging. The most evident changes are at the behavioral and cognitive level, with decreased learning capacity, recognition memory, and motor incoordination. The use of exogenous antioxidants has been implemented as a potential pharmacological option to delay the onset of brain aging by attenuating oxidative stress and neurodegeneration. Resveratrol (RSVL) is a polyphenol present in various foods, such as red fruits, and drinks, such as red wine. This compound has shown great antioxidant capacity due to its chemical structure. In this study, we evaluated the effect of chronic RSVL treatment on oxidative stress and cell loss in the prefrontal cortex, hippocampus, and cerebellum of 20-month-old rats, as well as its impact on recognition memory and motor behavior. Rats treated with RSVL showed an improvement in locomotor activity and in short- and long-term recognition memory. Likewise, the concentration of reactive oxygen species and lipid peroxidation decreased significantly in the group with RSVL, coupled with an improvement in the activity of the antioxidant system. Finally, with the help of hematoxylin and eosin staining, it was shown that chronic treatment with RSVL prevented cell loss in the brain regions studied. Our results demonstrate the antioxidant and neuroprotective capacity of RSVL when administered chronically. This strengthens the proposal that RSVL could be an important pharmacological option to reduce the incidence of neurodegenerative diseases that affect older adults.

VEGF-C promotes brain-derived fluid drainage, confers neuroprotection, and improves stroke outcomes

Meningeal lymphatic vessels promote tissue clearance and immune surveillance in the central nervous system (CNS). Vascular endothelium growth factor-C (VEGF-C) is essential for meningeal lymphatic development and maintenance and has therapeutic potential for treating neurological disorders, including ischemic stroke. We have investigated the effects of VEGF-C overexpression on brain fluid drainage, single cell transcriptome in the brain, and stroke outcomes in adult mice. Intra-cerebrospinal fluid administration of an adeno-associated virus expressing VEGF-C (AAV-VEGF-C) increases the CNS lymphatic network. Post-contrast T1 mapping of the head and neck showed that deep cervical lymph node size and drainage of CNS-derived fluids were increased. Single nuclei RNA sequencing revealed a neuro-supportive role of VEGF-C via upregulation of calcium and brain-derived neurotrophic factor (BDNF) signaling pathways in brain cells. In a mouse model of ischemic stroke, AAV-VEGF-C pretreatment reduced stroke injury and ameliorated motor performances in the subacute stage. AAV-VEGF-C thus promotes CNS-derived fluid and solute drainage, confers neuroprotection, and reduces ischemic stroke damage.

Short abstract

Intrathecal delivery of VEGF-C increases the lymphatic drainage of brain-derived fluids confers neuroprotection, and improves neurological outcomes after ischemic stroke.

The chronic stress risk phenotype mirrored in the human retina as a neurodegenerative condition

The brain is the key organ that orchestrates the stress response which translates to the retina. The retina is an extension of the brain and retinal symptoms in subjects with neurodegenerative diseases substantiated the eye as a window to the brain. The retina is used in this study to determine whether chronic stress reflects neurodegenerative signs indicative of neurodegenerative conditions. A 3-year prospective cohort (n = 333; aged 46 ± 9 years) was stratified into stress-phenotype cases (n = 212) and controls (n = 121) by applying the Malan stress-phenotype index. Neurodegenerative risk markers included ischemia (astrocytic S100 calcium-binding protein B/S100B); 24h blood pressure, proteomics; inflammation (tumor-necrosis-factor-α/TNF-α); neuronal damage (neuron-specific-enolase); anti-apoptosis of retinal-ganglion-cells (beta-nerve-growth-factor), astrocytic activity (glial-fibrillary-acidic-protein); hematocrit (viscosity) and retinal follow-up data [vessels; stress-optic-neuropathy]. Stress-optic-neuropathy risk was calculated from two indices: a newly derived diastolic-ocular-perfusion-pressure cut-point ≥68 mmHg relating to the stress-phenotype; combined with an established cup-to-disc ratio cut-point ≥0.3. Higher stress-optic-neuropathy (39% vs. 17%) and hypertension (73% vs. 16%) prevalence was observed in the stress-phenotype cases vs. controls. Elevated diastolic-ocular-perfusion-pressure, indicating hypoperfusion, was related to arterial narrowing and trend for ischemia increases in the stress-phenotype. Ischemia in the stress-phenotype at baseline, follow-up and 3-yr changes was related to consistent inflammation (TNF-α and cytokine-interleukin-17-receptor-A), neuron-specific-enolase increases, consistent apoptosis (chitinase 3-like-1, low beta-nerve-growth-factor), glial-fibrillary-acidic-protein decreases, elevated viscosity, vein widening as risk marker of endothelial dysfunction in the blood-retinal-barrier, lower vein count, and elevated stress-optic-neuropathy. The stress-phenotype and related neurodegenerative signs of ongoing brain ischemia, apoptosis and endothelial dysfunction compromised blood-retinal-barrier permeability and optic nerve integrity. In fact, the stress-phenotype could identify persons at high risk of neurodegeneration to indicate a neurodegenerative condition.

Therapeutic role of growth factors in treating diabetic wound

Wounds in diabetic patients, especially diabetic foot ulcers, are more difficult to heal compared with normal wounds and can easily deteriorate, leading to amputation. Common treatments cannot heal diabetic wounds or control their many complications. Growth factors are found to play important roles in regulating complex diabetic wound healing. Different growth factors such as transforming growth factor beta 1, insulin-like growth factor, and vascular endothelial growth factor play different roles in diabetic wound healing. This implies that a therapeutic modality modulating different growth factors to suit wound healing can significantly improve the treatment of diabetic wounds. Further, some current treatments have been shown to promote the healing of diabetic wounds by modulating specific growth factors. The purpose of this study was to discuss the role played by each growth factor in therapeutic approaches so as to stimulate further therapeutic thinking.

Adsorption of the rhNGF Protein on Polypropylene with Different Grades of Copolymerization

The surface properties of drug containers should reduce the adsorption of the drug and avoid packaging surface/drug interactions, especially in the case of biologically-derived products. Here, we developed a multi-technique approach that combined Differential Scanning Calorimetry (DSC), Atomic Force Microscopy (AFM), Contact Angle (CA), Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), and X-ray Photoemission Spectroscopy (XPS) to investigate the interactions of rhNGF on different pharma grade polymeric materials. Polypropylene (PP)/polyethylene (PE) copolymers and PP homopolymers, both as spin-coated films and injected molded samples, were evaluated for their degree of crystallinity and adsorption of protein. Our analyses showed that copolymers are characterized by a lower degree of crystallinity and lower roughness compared to PP homopolymers. In line with this, PP/PE copolymers also show higher contact angle values, indicating a lower surface wettability for the rhNGF solution on copolymers than PP homopolymers. Thus, we demonstrated that the chemical composition of the polymeric material and, in turn, its surface roughness determine the interaction with the protein and identified that copolymers may offer an advantage in terms of protein interaction/adsorption. The combined QCM-D and XPS data indicated that protein adsorption is a self-limiting process that passivates the surface after the deposition of roughly one molecular layer, preventing any further protein adsorption in the long term.

Safety, Tolerability, Pharmacokinetics, and Immunogenicity of a Novel Recombination Human Nerve Growth Factor in Healthy Chinese Subjects

BACKGROUND

Nerve growth factor (NGF), the first-discovered member of the neurotrophin family, has long been regarded as a potential drug to combat acute and chronic neurodegenerative processes. However, the pharmacokinetic profile of NGF is poorly described.

OBJECTIVES

The aim of this study was to investigate the safety, tolerability, pharmacokinetics, and immunogenicity of a novel recombinant human NGF (rhNGF) in healthy Chinese subjects.

METHOD

The study randomized 48 and 36 subjects to receive (i) single-ascending dose (SAD group; 7.5, 15, 30, 45, 60, 75 μg or placebo) and (ii) multiple-ascending dose (MAD group; 15, 30, 45 μg, or placebo) rhNGF intramuscular injections, respectively. In the SAD group, all participants received rhNGF or placebo only once. In the MAD group, participants were randomly assigned to receive multiple doses of rhNGF or placebo once a day for 7 consecutive days. Adverse events (AEs) and anti-drug antibodies (ADAs) were monitored throughout the study. Recombinant human NGF serum concentrations were determined using a highly sensitive enzyme-linked immunosorbent assay.

RESULTS

All AEs were mild, except for some injection-site pain and fibromyalgia, which were experienced as moderate AEs. Only one moderate AE was observed in the 15 μg cohort throughout the study and resolved within 24 hours of stopping dosing. Many participants (10% in 30 μg, 50% in 45 μg, and 50% in 60 μg in the SAD group; 10% in 15 μg, 30% in 30 μg, and 30% in 45 μg in the MAD group) experienced moderate fibromyalgia. However, all moderate fibromyalgia were resolved by the end of the subject's participation in the study. No severe AEs or clinically significant abnormalities were reported. All subjects in the 75 μg cohort experienced positive ADA in the SAD group, and one subject in the 30 μg dose and four subjects in the 45 μg dose also experienced positive ADA in the MAD group. Recombinant human nerve growth factor was absorbed (median T_max, 4.0-5.3 h) and eliminated biexponentially (mean t_1/2, 4.53-6.09 h) with a moderate speed. The C_max and AUC increased in an approximately dose-proportional manner over the dose range of 7.5-45 μg, and at doses higher than 45 μg these parameters increased more than dose proportionally. There was no obvious accumulation after 7 days of daily dosing of rhNGF.

CONCLUSION

The favorable safety and tolerability and predictable pharmacokinetic profile of rhNGF in healthy Chinese subjects support its continuing clinical development for the treatment of nerve injury and neurodegenerative diseases. The AEs and immunogenicity of rhNGF will continue to be monitored in future clinical trials.

TRIAL REGISTRATION

This study was registered with Chinadrugtrials.org.cn (ChiCTR2100042094) on January 13th, 2021.

A novel decellularized matrix of Wnt signaling-activated osteocytes accelerates the repair of critical-sized parietal bone defects with osteoclastogenesis, angiogenesis, and neurogenesis

Cell source is the key to decellularized matrix (DM) strategy. This study compared 3 cell types, osteocytes with/without dominant active Wnt/β-catenin signaling (daCO and WTO) and bone marrow stromal cells (BMSCs) for their DMs in bone repair. Decellularization removes all organelles and >95% DNA, and retained >74% collagen and >71% GAG, maintains the integrity of cell basement membrane with dense boundaries showing oval and honeycomb structure in osteocytic DM and smooth but irregular shape in the BMSC-DM. DM produced higher cell survival rate (90%) and higher proliferative activity. In vitro, daCO-DM induces more and longer stress fibers in BMSCs, conducive to cell adhesion, spreading, and osteogenic differentiation. 8-wk after implantation of the critical-sized parietal bone defect model, daCO-DM formed tight structures, composed of a large number of densely-arranged type-I collagen under polarized light microscope, which is similar to and integrated with host bone. BV/TV (>54%) was 1.5, 2.9, and 3.5 times of WTO-DM, BMSC-DM, and none-DM groups, and N.Ob/T.Ar (3.2 × 10²/mm²) was 1.7, 2.9, and 3.3 times. At 4-wk, daCO-DM induced osteoclastogenesis, 2.3 times higher than WTO-DM; but BMSC-DM or none-DM didn't. daCO-DM increased the expression of RANKL and MCSF, Vegfa and Angpt1, and Ngf in BMSCs, which contributes to osteoclastogenesis, angiogenesis, and neurogenesis, respectively. daCO-DM promoted H-type vessel formation and nerve markers β3-tubulin and NeuN expression. Conclusion: daCO-DM produces metabolic and neurovascularized organoid bone to accelerate the repair of bone defects. These features are expected to achieve the effect of autologous bone transplantation, suitable for transformation application.

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Decellularized matrix of osteocytes with dominant-active β-catenin (daCO-DM) promotes osteogenesis for regenerative repair.

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daCO-DM induces BMSCs to form stress fibers, conducive to cell adhesion, spreading, and differentiation towards osteoblasts.

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daCO-DM-induced osteoblasts have strong activity secreting dense and orderly-arranged type I collagen as host bone’s.

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daCO-DM induces BMSCs to express pre-osteoclastogenic cytokine RANKL and MCSF for osteoclastogenesis of marrow monocytes.

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daCO-DM enhances BMSCs to express angiogenic Vegfa and Angpt1, and neurogenic Ngf potentially for neurovascularization.

Recent Advances in Biomaterials-Based Therapies for Alleviation and Regeneration of Traumatic Brain Injury

Traumatic brain injury (TBI), a major public health problem accompanied with numerous complications, usually leads to serve disability and huge financial burden. The adverse and unfavorable pathological environment triggers a series of secondary injuries, resulting in serious loss of nerve function and huge obstacle of endogenous nerve regeneration. With the advances in adaptive tissue regeneration biomaterials, regulation of detrimental microenvironment to reduce the secondary injury and to promote the neurogenesis becomes possible. The adaptive biomaterials could respond and regulate biochemical, cellular, and physiological events in the secondary injury, including excitotoxicity, oxidative stress, and neuroinflammation, to rebuild circumstances suitable for regeneration. In this review, the development of pathology after TBI is discussed, followed by the introduction of adaptive biomaterials based on various pathological characteristics. The adaptive biomaterials carried with neurotrophic factors and stem cells for TBI treatment are then summarized. Finally, the current drawbacks and future perspective of biomaterials for TBI treatment are suggested.

Identification and validation of neurotrophic factor-related gene signatures in glioblastoma and Parkinson's disease

BACKGROUND

Glioblastoma multiforme (GBM) is the most common cancer of the central nervous system, while Parkinson's disease (PD) is a degenerative neurological condition frequently affecting the elderly. Neurotrophic factors are key factors associated with the progression of degenerative neuropathies and gliomas.

METHODS

The 2601 neurotrophic factor-related genes (NFRGs) available in the Genecards portal were analyzed and 12 NFRGs with potential roles in the pathogenesis of Parkinson's disease and the prognosis of GBM were identified. LASSO regression and random forest algorithms were then used to screen the key NFRGs. The correlation of the key NFRGs with immune pathways was verified using GSEA (Gene Set Enrichment Analysis). A prognostic risk scoring system was constructed using LASSO (Least absolute shrinkage and selection operator) and multivariate Cox risk regression based on the expression of the 12 NFRGs in the GBM cohort from The Cancer Genome Atlas (TCGA) database. We also investigated differences in clinical characteristics, mutational landscape, immune cell infiltration, and predicted efficacy of immunotherapy between risk groups. Finally, the accuracy of the model genes was validated using multi-omics mutation analysis, single-cell sequencing, QT-PCR, and HPA.

RESULTS

We found that 4 NFRGs were more reliable for the diagnosis of Parkinson's disease through the use of machine learning techniques. These results were validated using two external cohorts. We also identified 7 NFRGs that were highly associated with the prognosis and diagnosis of GBM. Patients in the low-risk group had a greater overall survival (OS) than those in the high-risk group. The nomogram generated based on clinical characteristics and risk scores showed strong prognostic prediction ability. The NFRG signature was an independent prognostic predictor for GBM. The low-risk group was more likely to benefit from immunotherapy based on the degree of immune cell infiltration, expression of immune checkpoints (ICs), and predicted response to immunotherapy. In the end, 2 NFRGs (EN1 and LOXL1) were identified as crucial for the development of Parkinson's disease and the outcome of GBM.

CONCLUSIONS

Our study revealed that 4 NFRGs are involved in the progression of PD. The 7-NFRGs risk score model can predict the prognosis of GBM patients and help clinicians to classify the GBM patients into high and low risk groups. EN1, and LOXL1 can be used as therapeutic targets for personalized immunotherapy for patients with PD and GBM.

Involvement of nerve growth factor (NGF) in chronic neuropathic pain - a systematic review

Pain is a complex experience, encompassing physiological and psychological components. Amongst the different types of pain, neuropathic pain, resulting from injuries to the peripheral or central nervous system, still constitutes a challenge for researchers and clinicians. Nerve growth factor (NGF) is currently regarded as a key contributor and may serve as a therapeutic target in many types of pain, likely including neuropathic pain. Here, we reviewed the role of NGF in neuropathic pain of peripheral and central origin, also addressing its potential use as a pharmacological target to better help patients dealing with this condition that severely impacts the everyday life. For this, we conducted a search in the databases PubMed and Scopus. Our search resulted in 1103 articles (458 in PubMed and 645 in Scopus). Only articles related to the involvement of NGF in pain or articles that approached its potential use as a target in treatment of pain symptoms were included. Duplicates were eliminated and 274 articles were excluded. After careful analysis, 23 articles were selected for review. Original articles studying the role of NGF in pathology as well as its modulation as a possible therapeutic target were included. We found that NGF is widely regarded as a key player in neuropathic pain and seen as a putative therapeutic target. However, evidence obtained from years of clinical trials highlights the toxic adverse effects of anti-NGF therapeutics, precluding its use in clinical context. Further studies are, thus, needed to improve treatment of chronic neuropathic pain.

NGF and Its Role in Immunoendocrine Communication during Metabolic Syndrome

Nerve growth factor (NGF) was the first neurotrophin described. This neurotrophin contributes to organogenesis by promoting sensory innervation and angiogenesis in the endocrine and immune systems. Neuronal and non-neuronal cells produce and secrete NGF, and several cell types throughout the body express the high-affinity neurotrophin receptor TrkA and the low-affinity receptor p75NTR. NGF is essential for glucose-stimulated insulin secretion and the complete development of pancreatic islets. Plus, this factor is involved in regulating lipolysis and thermogenesis in adipose tissue. Immune cells produce and respond to NGF, modulating their inflammatory phenotype and the secretion of cytokines, contributing to insulin resistance and metabolic homeostasis. This neurotrophin regulates the synthesis of gonadal steroid hormones, which ultimately participate in the metabolic homeostasis of other tissues. Therefore, we propose that this neurotrophin's imbalance in concentrations and signaling during metabolic syndrome contribute to its pathophysiology. In the present work, we describe the multiple roles of NGF in immunoendocrine organs that are important in metabolic homeostasis and related to the pathophysiology of metabolic syndrome.

Clinical observation of recombinant human nerve growth factor in the treatment of neurotrophic keratitis

AIM

To characterize changes of corneal nerve morphology and tear indices in patients with neurotrophic keratitis (NK) treated with recombinant human nerve growth factor (rhNGF).

METHODS

In a prospective observational study, six patients (nine eyes) were locally treated with rhNGF. Visual acuity, corneal fluorescein staining score, the heights of the tear river, lipid layer thickness (LLT), tear ferning (TF) test, conjunctival impression cytology (CIC) examination, the densities of cornea subbasal nerve fibers were determined before and after treatment.

RESULTS

Compared with baseline, there was a significant difference in corneal fluorescence staining scores (P<0.01); all patient corneal epithelial defects recovered completely within 8wk, but there was no significant improvement in the height of the tear river (P=0.202). LLT was significantly increased when compared with baseline (P=0.042); however, the function of conjunctival goblet cells and mucin content did not significantly improve using the TF test and CIC examination (P=0.557, P=0.539). After 8wk of treatment, the average corneal subbasal nerve fiber density increased significantly (P<0.01), as did the number of corneal nerve fiber branches (P=0.001).

CONCLUSION

RhNGF can increase the density of corneal subbasal nerve fibers, promote the healing of persistent corneal epithelial defects and corneal ulcers in patients with NK, also improving tear function partially.

Nucleic acid drug vectors for diagnosis and treatment of brain diseases

Nucleic acid drugs have the advantages of rich target selection, simple in design, good and enduring effect. They have been demonstrated to have irreplaceable superiority in brain disease treatment, while vectors are a decisive factor in therapeutic efficacy. Strict physiological barriers, such as degradation and clearance in circulation, blood-brain barrier, cellular uptake, endosome/lysosome barriers, release, obstruct the delivery of nucleic acid drugs to the brain by the vectors. Nucleic acid drugs against a single target are inefficient in treating brain diseases of complex pathogenesis. Differences between individual patients lead to severe uncertainties in brain disease treatment with nucleic acid drugs. In this Review, we briefly summarize the classification of nucleic acid drugs. Next, we discuss physiological barriers during drug delivery and universal coping strategies and introduce the application methods of these universal strategies to nucleic acid drug vectors. Subsequently, we explore nucleic acid drug-based multidrug regimens for the combination treatment of brain diseases and the construction of the corresponding vectors. In the following, we address the feasibility of patient stratification and personalized therapy through diagnostic information from medical imaging and the manner of introducing contrast agents into vectors. Finally, we take a perspective on the future feasibility and remaining challenges of vector-based integrated diagnosis and gene therapy for brain diseases.

Nerve growth factor causes epinephrine release dysfunction by regulating phenotype alterations and the function of adrenal medullary chromaffin cells in mice with allergic rhinitis

The presence of allergic rhinitis (AR) is an increased risk factor for the occurrence of bronchial asthma (BA). Nerve growth factor (NGF), in addition to its key role in the development and differentiation of neurons, may also be an important inflammatory factor in AR and BA. However, the pathogenesis of the progression of AR to BA remains to be elucidated. The present study aimed to investigate the ability of NGF to mediate nasobronchial interactions and explore possible underlying molecular mechanisms. In the present study, an AR mouse model was established and histology of nasal mucosa tissue injury was determined. The level of phenylethanolamine N‑methyl transferase in adrenal medulla was determined by immunofluorescence. Primary adrenal medullary chromaffin cells (AMCCs) were isolated and cultured from the adrenal medulla of mice. The expression levels of synaptophysin (SYP), STAT1, JAK1, p38 and ERK in NGF‑treated and untreated AMCCs were detected by reverse‑transcription‑quantitative PCR and western blotting. The epinephrine (EPI) and norepinephrine (NE) concentrations were measured by ELISA. It was found that the expression of SYP in AMCCs was enhanced in the presence of NGF, whereas, the concentration of EPI decreased significantly under the same conditions. Furthermore, NGF mediated the phenotypic and functional changes of AMCCs, resulting in decreased EPI secretion via JAK1/STAT1, p38 and ERK signaling. In conclusion, these findings could provide novel evidence for the role of NGF in regulating neuroendocrine mechanisms.

TrkA inhibition alleviates bladder overactivity in cyclophosphamide-induced cystitis by targeting hyperpolarization-activated cyclic nucleotide-gated channels

Objectives

To investigate the potential of Tropomyosin receptor kinase A (TrkA) for the treatment of interstitial cystitis/ bladder pain syndrome (IC/BPS).

Materials and Methods

Sixty-four female rats were randomly assigned to the control and cyclophosphamide (CYP) groups. Quantitative reverse transcription polymerase chain reaction was utilized to detect the mRNA level of TrkA. Western blot analysis was used to measure the protein levels of TNF-α, IL-6, and TrkA. Immunostaining was used to detect the expression of TrkA in bladder sections. Contractility studies and urodynamic measurements were utilized to test the spontaneous contractions of detrusor muscle strips and the global bladder activity, respectively.

Results

Rat models of chronic cystitis were successfully established. The mRNA and protein levels of TrkA were significantly increased in the bladders of CYP-treated rats. Also, results of immunohistochemical staining and immunofluorescence staining showed that increased TrkA expression in the CYP group was mainly observed in the urothelium layer and bladder interstitial Cajal-like cells (ICC-LCs) but not in the detrusor smooth muscle cells. The specific inhibitor of TrkA, GW441756 (10 μM), significantly suppressed the robust spontaneous contractions of detrusor muscle strips in the CYP group and alleviated the overall bladder overactivity of CYP-treated rats. However, the inhibitory effects of GW441756 (10 μM) on the spontaneous contractions of detrusor muscle strips and the overall bladder activity were eliminated after pretreatments with the specific blocker of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, ZD7288 (50 μM).

Conclusion

Our results suggested that increased TrkA expression during chronic cystitis promotes the development of bladder overactivity by targeting the HCN channels.

Nerve growth factor promotes differentiation and protects the oligodendrocyte precursor cells from in vitro hypoxia/ischemia

Introduction

Nerve growth factor (NGF) is a pleiotropic molecule acting on different cell types in physiological and pathological conditions. However, the effect of NGF on the survival, differentiation and maturation of oligodendrocyte precursor cells (OPCs) and oligodendrocytes (OLs), the cells responsible for myelin formation, turnover, and repair in the central nervous system (CNS), is still poorly understood and heavily debated.

Methods

Here we used mixed neural stem cell (NSC)-derived OPC/astrocyte cultures to clarify the role of NGF throughout the entire process of OL differentiation and investigate its putative role in OPC protection under pathological conditions.

Results

We first showed that the gene expression of all the neurotrophin receptors (TrkA, TrkB, TrkC, and p75^NTR ) dynamically changes during the differentiation. However, only TrkA and p75^NTR expression depends on T3-differentiation induction, as Ngf gene expression induction and protein secretion in the culture medium. Moreover, in the mixed culture, astrocytes are the main producer of NGF protein, and OPCs express both TrkA and p75^NTR . NGF treatment increases the percentage of mature OLs, while NGF blocking by neutralizing antibody and TRKA antagonist impairs OPC differentiation. Moreover, both NGF exposure and astrocyte-conditioned medium protect OPCs exposed to oxygenglucose deprivation (OGD) from cell death and NGF induces an increase of AKT/pAKT levels in OPCs nuclei by TRKA activation.

Discussion

This study demonstrated that NGF is implicated in OPC differentiation, maturation, and protection in the presence of metabolic challenges, also suggesting implications for the treatment of demyelinating lesions and diseases.

Neuroprotective Effects of Nanowired Delivery of Cerebrolysin with Mesenchymal Stem Cells and Monoclonal Antibodies to Neuronal Nitric Oxide Synthase in Brain Pathology Following Alzheimer's Disease Exacerbated by Concussive Head Injury

Concussive head injury (CHI) is one of the major risk factors in developing Alzheimer's disease (AD) in military personnel at later stages of life. Breakdown of the blood-brain barrier (BBB) in CHI leads to extravasation of plasma amyloid beta protein (ΑβP) into the brain fluid compartments precipitating AD brain pathology. Oxidative stress in CHI or AD is likely to enhance production of nitric oxide indicating a role of its synthesizing enzyme neuronal nitric oxide synthase (NOS) in brain pathology. Thus, exploration of the novel roles of nanomedicine in AD or CHI reducing NOS upregulation for neuroprotection are emerging. Recent research shows that stem cells and neurotrophic factors play key roles in CHI-induced aggravation of AD brain pathologies. Previous studies in our laboratory demonstrated that CHI exacerbates AD brain pathology in model experiments. Accordingly, it is quite likely that nanodelivery of NOS antibodies together with cerebrolysin and mesenchymal stem cells (MSCs) will induce superior neuroprotection in AD associated with CHI. In this review, co-administration of TiO2 nanowired cerebrolysin - a balanced composition of several neurotrophic factors and active peptide fragments, together with MSCs and monoclonal antibodies (mAb) to neuronal NOS is investigated for superior neuroprotection following exacerbation of brain pathology in AD exacerbated by CHI based on our own investigations. Our observations show that nanowired delivery of cerebrolysin, MSCs and neuronal NOS in combination induces superior neuroprotective in brain pathology in AD exacerbated by CHI, not reported earlier.

NR3C1 gene methylation and cortisol levels in preterm and healthy full-term infants in the first 3 months of life

Aim: To describe NR3C1 exon-1F methylation and cortisol levels in newborns. Materials & methods: Preterm ≤1500 g and full-term infants were included. Samples were collected at birth and at days 5, 30 and 90 (or at discharge). Results: 46 preterm and 49 full-term infants were included. Methylation was stable over time in full-term infants (p = 0.3116) but decreased in preterm infants (p = 0.0241). Preterm infants had higher cortisol levels on the fifth day, while full-term infants showed increasing levels (p = 0.0177) over time. Conclusion: Hypermethylated sites in NR3C1 at birth and higher cortisol levels on day 5 suggest that prematurity, reflecting prenatal stress, affects the epigenome. Methylation decrease over time in preterm infants suggests that postnatal factors may modify the epigenome, but their role needs to be clarified.

Secretome as neuropathology-targeted intervention of Parkinson’s disease

Parkinson’s disease (PD) is the second most common progressive neurodegenerative disease, characterized by apoptosis of dopaminergic neurons in substansia nigra pars compacta (SNpc) caused by ⍺-synuclein aggregation. The use of secretomes released by medicinal signaling cells (MSCs) is one the promising preventive approaches that target several mechanisms in the neuropathology of PD. Its components target the lack of neurotrophin factors, proteasome dysfunction, oxidative stress, mitochondrial dysfunction, and at last neuroinflammation via several pathways. The complex and obscure pathology of PD induce the difficulty of the search of potential preventive approach for this disease. We described the potential of secretome of MSC as the novel preventive approach for PD, especially by targeting the said major pathogenesis of PD.

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Secretome targets the major pathogenesis of PD.

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Secretome regulates inflammation by balancing pro- and anti-inflammatory cytokines.

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Secretome induces autophagy providing cytoprotective effects.

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Secretome has anti-oxidative, neuroprotective, and neurotrophic due to neurotrophic factors as its component.

Nucleic acid therapies for CNS diseases: Pathophysiology, targets, barriers, and delivery strategies

Nucleic acid therapeutics have emerged as one of the very advanced and efficacious treatment approaches for debilitating health conditions, including those diseases affecting the central nervous system (CNS). Precise targeting with an optimal control over gene regulation confers long-lasting benefits through the administration of nucleic acid payloads via viral, non-viral, and engineered vectors. The current review majorly focuses on the development and clinical translational potential of non-viral vectors for treating CNS diseases with a focus on their specific design and targeting approaches. These carriers must be able to surmount the various intracellular and extracellular barriers, to ensure successful neuronal transfection and ultimately attain higher therapeutic efficacies. Additionally, the specific challenges associated with CNS administration also include the presence of blood-brain barrier (BBB), the complex pathophysiological and biochemical changes associated with different disease conditions and the existence of non-dividing cells. The advantages offered by lipid-based or polymeric systems, engineered proteins, particle-based systems coupled with various approaches of neuronal targeting have been discussed in the context of a variety of CNS diseases. The possibilities of rapid yet highly efficient gene modifications rendered by the breakthrough methodologies for gene editing and gene manipulation have also opened vast avenues of research in neuroscience and CNS disease therapy. The current review also underscores the extensive scientific efforts to optimize specialized, efficacious yet non-invasive and safer administration approaches to overcome the therapeutic delivery challenges specifically posed by the CNS transport barriers and the overall obstacles to clinical translation.

Protective Effects of Choline against Inflammatory Cytokines and Characterization of Transport in Motor Neuron-like Cell Lines (NSC-34)

Choline, a component of the neurotransmitter acetylcholine, is essential for nervous system functions, brain development, and gene expression. In our study, we investigated the protective effect and transport characteristics of choline in amyotrophic lateral sclerosis (ALS) model cell lines. We used the wild-type (WT) motor neuron-like hybrid cell line (NSC-34/hSOD1WT) as a control and the mutant-type (MT; NSC-34/hSOD1G93A) as a disease model. The uptake of [3H]choline was time-, pH-, and concentration-dependent. [3H]Choline transport was sodium-dependent, and, upon pretreatment with valinomycin, induced membrane depolarization. Gene knockdown of Slc44a1 revealed that choline-like transporter 1 (CTL1) mediates the transport of choline. In NSC-34 cell lines, the specific choline transporter inhibitor, hemicholinium-3 demonstrated significant inhibition. Donepezil and nifedipine caused dose-dependent inhibition of [3H]choline uptake by the MT cell line with minimal half inhibitory concentration (IC50) values of 0.14 mM and 3.06 mM, respectively. Four-day pretreatment with nerve growth factor (NGF) resulted in an inhibitory effect on [3H]choline uptake. Choline exerted protective and compensatory effects against cytokines mediators. Hence, the choline transport system CLT1 may act as a potential target for the delivery of novel pharmacological drugs, and the combination of drugs with choline can help treat symptoms related to ALS.

Intra-amniotic transplantation of brain-derived neurotrophic factor-modified mesenchymal stem cells treatment for rat fetuses with spina bifida aperta

Background

Spina bifida aperta (SBA) is a relatively common clinical type of neural tube defect. Although prenatal fetal surgery has been proven to be an effective treatment for SBA, the recovery of neurological function remains unsatisfactory due to neuron deficiencies. Our previous results demonstrated that intra-amniotic transplanted bone marrow mesenchymal stem cells (BMSCs) could preserve neural function through lesion-specific engraftment and regeneration. To further optimize the role of BMSCs and improve the environment of defective spinal cords so as to make it more conducive to nerve repair, the intra-amniotic transplanted BMSCs were modified with brain-derived neurotrophic factor (BDNF-BMSCs), and the therapeutic potential of BDNF-BMSCs was verified in this study.

Methods

BMSCs were modified by adenovirus encoding a green fluorescent protein and brain-derived neurotrophic factor (Ad-GFP-BDNF) in vitro and then transplanted into the amniotic cavity of rat fetuses with spina bifida aperta which were induced by all-trans-retinoic acid on embryonic day 15. Immunofluorescence, western blot and real-time quantitative PCR were used to detect the expression of different neuron markers and apoptosis-related genes in the defective spinal cords. Lesion areas of the rat fetuses with spina bifida aperta were measured on embryonic day 20. The microenvironment changes after intra-amniotic BDNF-BMSCs transplantation were investigated by a protein array with 90 cytokines.

Results

We found that BDNF-BMSCs sustained the characteristic of directional migration, engrafted at the SBA lesion area, increased the expression of BDNF in the defective spinal cords, alleviated the apoptosis of spinal cord cells, differentiated into neurons and skin-like cells, reduced the area of skin lesions, and improved the amniotic fluid microenvironment. Moreover, the BDNF-modified BMSCs showed a better effect than pure BMSCs on the inhibition of apoptosis and promotion of neural differentiation.

Conclusion

These findings collectively indicate that intra-amniotic transplanted BDNF-BMSCs have an advantage of promoting the recovery of defective neural tissue of SBA fetuses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03105-6.

Muscle-derived Stem Cells Combined With Nerve Growth Factor Transplantation in the Treatment of Stress Urinary Incontinence

OBJECTIVE

To investigate the efficacy of muscle-derived stem cells (MDSCs) combined with nerve growth factor (NGF) in the treatment of stress urinary incontinence (SUI) METHODS: MDSCs were isolated and extracted from 90 SD rats, and the stem cell characteristics of the cells were identified using flow cytometry. NGF overexpression (oe-NGF) plasmid was coated with adenovirus and qRT-PCR was applied to verify adenovirus transfection efficiency. The rat models of SUI were constructed and randomly divided into 5 groups: control group, phosphate buffer (PBS) group, MDSCs + oe-NGF group, MDSCs + vector group, and MDSCs group. After 8 weeks of feeding, the leakage point pressure (LPP) rats, and Masson staining of rat urethral sections were detected. The expression of NGF and vascular endothelial growth factor (VEGF) was detected by western blot and IHC staining.

RESULTS

Compared with the control group, the LPP and the ratio of muscle fibers/collagen fibers were significantly increased in the MDSCs treated groups, with the highest increase in the MDSCs + oe-NGF group. Western blot and IHC results showed that the expression of NGF and VEGF in the urethral tissues in the MDSCs treated groups were significantly up-regulated comparing with the control group, with the highest increase in the MDSCs + oe-NGF group.

CONCLUSION

MDSCs alone can relieve SUI, while MDSCs combined with NGF is more effective, which may be related to the up-regulating of VEGF.

Glioma‑neuronal interactions in tumor progression: Mechanism, therapeutic strategies and perspectives (Review)

An increasing body of evidence has become available to reveal the synaptic and functional integration of glioma into the brain network, facilitating tumor progression. The novel discovery of glioma-neuronal interactions has fundamentally challenged our understanding of this refractory disease. The present review aimed to provide an overview of how the neuronal activities function through synapses, neurotransmitters, ion channels, gap junctions, tumor microtubes and neuronal molecules to establish communications with glioma, as well as a simplified explanation of the reciprocal effects of crosstalk on neuronal pathophysiology. In addition, the current state of therapeutic avenues targeting critical factors involved in glioma-euronal interactions is discussed and an overview of clinical trial data for further investigation is provided. Finally, newly emerging technologies, including immunomodulation, a neural stem cell-based delivery system, optogenetics techniques and co-culture of neuron organoids and glioma, are proposed, which may pave a way towards gaining deeper insight into both the mechanisms associated with neuron- and glioma-communicating networks and the development of therapeutic strategies to target this currently lethal brain tumor.

VGF: A prospective biomarker and therapeutic target for neuroendocrine and nervous system disorders

Neuroendocrine regulatory polypeptide VGF (nerve growth factor inducible) was firstly found in the rapid induction of nerve growth factor on PC12 cells. It was selectively distributed in neurons and many neuroendocrine tissues. This paper reviewed the latest literatures on the gene structure, transcriptional regulation, protein processing, distribution and potential receptors of VGF. The neuroendocrine roles of VGF and its derived polypeptides in regulating energy, water electrolyte balance, circadian rhythm and reproductive activities were also summarized. Furthermore, based on the experimental evidence in vivo and in vitro, dysregulation of VGF in different neuroendocrine diseases and the possible mechanism mediated by VGF polypeptides were discussed. We next discussed the potential as the clinical diagnosis and therapy for VGF related diseases in the future.

7,8-Dihydroxyflavone and Neuropsychiatric Disorders: A Translational Perspective from the Mechanism to Drug Development

7,8-Dihydroxyflavone (7,8-DHF) is a kind of natural flavonoid with the potential to cross the blood-brain barrier. 7,8-DHF effectively mimics the effect of brain-derived neurotrophic factor (BDNF) in the brain to selectively activate tyrosine kinase receptor B (TrkB) and downstream signaling pathways, thus playing a neuroprotective role. The preclinical effects of 7,8-DHF have been widely investigated in neuropsychiatric disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), depression, and memory impairment. Besides the effect on TrkB, 7,8-DHF could also function through fighting against oxidative stress, cooperating with estrogen receptors, or regulating intestinal flora. This review focuses on the recent experimental studies on depression, neurodegenerative diseases, and learning and memory functions. Additionally, the structural modification and preparation of 7,8-DHF were also concluded and proposed, hoping to provide a reference for the follow-up research and clinical drug development of 7,8-DHF in the field of neuropsychiatric disorders.

Newer advances in medical management of glaucoma

The burden of irreversible vision loss from Glaucoma continues to rise. While the disease pathogenesis is not well understood, intraocular pressure (IOP) is the only modifiable risk factor identified to prevent glaucomatous vision loss. Medical management remains the first-line of treatment in most adult glaucomas and the evolution of medical therapy for glaucoma has followed an exponential curve. This review tracks the rapid development of new medications and drug delivery systems in the recent years. Introduction of Rho kinase inhibitors with an entirely new mechanism of action from that of the currently used anti glaucoma medications has been a significant milestone. Latanoprostene Bunod is a novel, single molecule which provides two active metabolites that work through two different pathways for reducing intra ocular pressure. Bimatoprost implants and travoprost punctum plugs attempt to ease chronic medication use in glaucoma patients. Nanotechnology is an evolving route of drug delivery. Role of cannabinoids in medical management of glaucoma remain equivocal. The relatively short term effect on IOP, the risks of developing tolerance and side effects impacting patients' neurocognitive health greatly outweigh the potential benefit. Research on Latrunculin B, Adenosine receptor agonists, Specific gene silencing and Stem cell therapy are poised to make an impact on glaucoma treatment. While there is some evidence to support the role of Brimonidine in neuroprotection, further research is needed to clarify the role of Memantine and Neurotrophins. Evidence for benefit from dietary supplementation with Alpha lipoic acid, Forskolin , and Ginko Biloba is limited.

Low-Molecular-Weight Perorally Active Nerve Growth Factor Mimetic Reduces Manifestations of Diabetic Neuropathy in Wistar Rats

A low-molecular-weight nerve growth factor mimetic, compound GK-2 (bis-(N-monosuccinyl- L-glutamyl-L-lysine)hexamethylenediamide) that previously demonstrated antidiabetic activity in rats with streptozotocin-induced type 2 diabetes mellitus was studied on the model of diabetic neuropathy. It was found that in 8 weeks after diabetes mellitus development, untreated diabetic rats demonstrated impaired tactile sensitivity in von Frey test, while GK-2 therapy (7.5 mg/kg orally for 28 days) restored this parameter. The decrease of tactile sensitivity in diabetic neuropathy closely correlated with the severity of hyperglycemia (r=0.76). Our findings are consistent with the concept on the role of glucose toxicity and nerve growth factor deficiency in the pathogenesis of diabetic neuropathy and attest to feasibility of further studies of nerve growth factor mimetic GK-2 as a potential treatment for diabetes and diabetic neuropathy.

Electrophysiological and pathological changes in the vastus medialis and vastus lateralis muscles after early patellar reduction and nerve growth factor injection in rabbits with patellar dislocation

BACKGROUND

Patellar dislocation can cause a series of changes in the trochlear groove and patella. However, the influence of patellar dislocation on the medialis (VM) and vastus lateralis (VL) muscles and whether nerve growth factor (NGF) is beneficial to proprioceptive rehabilitation for patellar dislocation are unknown. The purpose of this study was to investigate the effects on VM and VL after the injection of NGF and early reduction in rabbits for patellar dislocation with electrophysiological and pathological analysis.

METHODS

Sixty 2-month-old rabbits were randomly divided into four groups (15 rabbits in each group). Rabbits in Group 1, Group 2, and Group 3 underwent patellar dislocation surgery, and rabbits in Group 4 underwent sham surgery. One month later, patellar reduction was performed in Groups 1 and 2. NGF was injected into the rabbits of Group 1. The electrophysiological and pathological changes in VM and VL were analyzed at 1 month and 3 months after patellar reduction.

RESULTS

The electrophysiological and pathological indices in Groups 1 and 2 were significantly different from those in Group 3 at 1 and 3 months after patellar reduction. There were significant differences between NGF injection Group 1 and Group 2 without NGF injection. There was no significant difference between Group 1 and Group 4 at 3 months after patellar reduction.

CONCLUSIONS

Patellar dislocation can cause abnormal electrophysiological and pathological effects on VM and VL. Patellar reduction should be performed as early as possible, and NGF injection may be beneficial to the rehabilitation of proprioception.

Hypoxia Induces DPSC Differentiation versus a Neurogenic Phenotype by the Paracrine Mechanism

As previously described by several authors, dental pulp stem cells (DPSCs), when adequately stimulated, may acquire a neuronal-like phenotype acting as a favorable source of stem cells in the generation of nerves. Besides, it is known that hypoxia conditioning is capable of stimulating cell differentiation as well as survival and self-renewal, and that multiple growth factors, including Epidermal Growth factor (EGF) and basic fibroblast growth factor (bFGF), are often involved in the induction of the neuronal differentiation of progenitor cells. In this work, we investigated the role of hypoxia in the commitment of DPSCs into a neuronal phenotype. These cells were conditioned with hypoxia (O₂ 1%) for 5 and 16 days; subsequently, we analyzed the proliferation rate and morphology, and tested the cells for neural and stem markers. Moreover, we verified the possible autocrine/paracrine role of DPSCs in the induction of neural differentiation by comparing the secretome profile of the hypoxic and normoxic conditioned media (CM). Our results showed that the hypoxia-mediated DPSC differentiation was time dependent. Moreover, conditioned media (CM derived from DPSCs stimulated by hypoxia were able, in turn, to induce the neural differentiation of SH-SY5Y neuroblastoma cells and undifferentiated DPSCs. In conclusion, under the herein-mentioned conditions, hypoxia seems to favor the differentiation of DPSCs into neuron-like cells. In this way, we confirm the potential clinical utility of differentiated neuronal DPSCs, and we also suggest the even greater potential of CM-derived-hypoxic DPSCs that could more readily be used in regenerative therapies.

Immunotargets and Therapy for Prurigo Nodularis

Prurigo nodularis is a chronic inflammatory skin disease consisting of severely pruritic nodules that can be very debilitating for patients. The basis of this skin condition is immunological dysregulation and neural amplification, driven by T-lymphocytes, mast cells, eosinophilic granulocytes, macrophages, and cytokines mediating itchy processes. Further complicating this already taxing diagnosis is the lack of approved treatment and consensus on management; although there are off-label treatments utilized as therapy. Immunomodulators are the cornerstone of treatment for PN, and additional novel therapies targeting key players in the immunological cascade are currently undergoing investigation. In this review, we will highlight targets of the immune cascade and explore current immunomodulating treatments as well as immunotherapies on the horizon for the management of prurigo nodularis.

Study of the influence of NGF-β gene overexpression in human mesenchymal stem cells on the expression level of SOX1 and neural pathway genes

BACKGROUND

Nerve growth factor (NGF) is a protein exhibiting an influence on the neural development and also, its' impact on the stem cells remains a great potential treatment strategy. The influence of its overexpression on the neural pathway differentiation on Wharton's Jelly derived MSC (WJ-MSC) has not been studied so far, but considering the fact that these cells are relatively easy to obtain, using them may indicate an innovative change in stem cell therapies. The aim of this study was to evaluate the effect of NGF overexpression in human mesenchymal stem cells (MSC) on SOX1 and genes related to the neural pathway.

METHODS AND RESULTS

The lentiviral transduction was performed in order to obtain the NGF overexpression, as well as RT-PCR to evaluate the expression level SOX1, SOX2, NES, NGF under influence of overexpressed NGF protein in WJ-MSC. During the study we have observed a decrease in SOX1 expression as the marker of neural stem cells. Other than that an increase of SOX2, NES and NGF was noticed, as they all are markers of early-neural as well as already differentiated neural cells. The results show a great potential of using those examined genes' expression as a form of a new stem cell therapy.

CONCLUSIONS

The achieved overexpression of NGF in this study, led the modified MSC onto the neural pathway as well as caused a decrease of SOX1 expression and an increase of expression of genes related to neural differentiated cells.

ENT-A010, a Novel Steroid Derivative, Displays Neuroprotective Functions and Modulates Microglial Responses

Tackling neurodegeneration and neuroinflammation is particularly challenging due to the complexity of central nervous system (CNS) disorders, as well as the limited drug accessibility to the brain. The activation of tropomyosin-related kinase A (TRKA) receptor signaling by the nerve growth factor (NGF) or the neurosteroid dehydroepiandrosterone (DHEA) may combat neurodegeneration and regulate microglial function. In the present study, we synthesized a C-17-spiro-cyclopropyl DHEA derivative (ENT-A010), which was capable of activating TRKA. ENT-A010 protected PC12 cells against serum starvation-induced cell death, dorsal root ganglia (DRG) neurons against NGF deprivation-induced apoptosis and hippocampal neurons against Aβ-induced apoptosis. In addition, ENT-A010 pretreatment partially restored homeostatic features of microglia in the hippocampus of lipopolysaccharide (LPS)-treated mice, enhanced Aβ phagocytosis, and increased Ngf expression in microglia in vitro. In conclusion, the small molecule ENT-A010 elicited neuroprotective effects and modulated microglial function, thereby emerging as an interesting compound, which merits further study in the treatment of CNS disorders.

Intravitreal Administration of rhNGF Enhances Regenerative Processes in a Zebrafish Model of Retinal Degeneration

Nerve growth factor (NGF) is the best characterized neurotrophin, and it is known to play an important role in ocular homeostasis. Here, we demonstrated the expression of NGF receptors in adult zebrafish retina and optimized a light-induced retina degeneration (LID) zebrafish model that mimics human cone-rod disorders, demonstrating that intravitreal (IV) administration of rhNGF can boost zebrafish retinal regeneration in this model. Adult zebrafish retinae exposed to 60 h of light irradiation (60 h LID) displayed evident reduction of outer nuclear layer (ONL) thickness and cell number with presence of apoptotic cells. Retinal histologic evaluation at different time points showed that IV therapeutic injection of rhNGF resulted in an increase of ONL thickness and cell number at late time points after damage (14 and 21 days post injury), ultimately accelerating retinal tissue recovery by driving retinal cell proliferation. At a molecular level, rhNGF activated the ERK1/2 pathway and enhanced the regenerative potential of Müller glia gfap- and vim-expressing cells by stimulating at early time points the expression of the photoreceptor regeneration factor Drgal1-L2. Our results demonstrate the highly conserved nature of NGF canonical pathway in zebrafish and thus support the use of zebrafish models for testing new compounds with potential retinal regenerative properties. Moreover, the pro-regenerative effects of IV-injected NGF that we observed pave the way to further studies aimed at evaluating its effects also in mammals, in order to expedite the development of novel rhNGF-based therapeutic approaches for ophthalmological disorders.

Protective Effects of a synthetic glycosaminoglycan mimetic (OTR4132) in a rat immunotoxic lesion model of septohippocampal cholinergic degeneration

Using a partial hippocampal cholinergic denervation model, we assessed the effects of the RGTA^® named OTR4132, a synthetic heparan-mimetic biopolymer with neuroprotective/neurotrophic properties. Long-Evans male rats were injected with the cholinergic immunotoxin 192 IgG-saporin into the medial septum/diagonal band of Broca (0.37 µg); vehicle injections served as controls. Immediately after surgery, OTR4132 was injected into the lateral ventricles (0.25 µg/5 µl/rat) or intramuscularly (1.5 mg/kg). To determine whether OTR4132 reached the lesion site, some rats received intracerebroventricular (ICV) or intramuscular (I.M.) injections of fluorescent OTR4132. Rats were sacrificed at 4, 10, 20, or 60 days post-lesion (DPL). Fluorescein-labeled OTR4132 injected ICV or I.M. was found in the lesion from 4 to 20 DPL. Rats with partial hippocampal cholinergic denervation showed decreases in hippocampal acetylcholinesterase reaction products and in choline acetyltransferase-positive neurons in the medial septum. These lesions were the largest at 10 DPL and then remained stable until 60 DPL. Both hippocampal acetylcholinesterase reaction products and choline acetyltransferase-positive neurons in the medial septum effects were significantly attenuated in OTR4132-treated rats. These effects were not related to competition between OTR4132 and 192 IgG-saporin for the neurotrophin receptor P75 (p75^NTR), as OTR4132 treatment did not alter the internalization of Cy3-labelled 192 IgG. OTR4132 was more efficient at reducing the acetylcholinesterase reaction products and choline acetyltransferase-positive neurons than a comparable heparin dose used as a comparator. Using the slice superfusion technique, we found that the lesion-induced decrease in muscarinic autoreceptor sensitivity was abolished by intramuscular OTR4132. After partial cholinergic damage, OTR4132 was able to concentrate at the brain lesion site possibly due to the disruption of the blood-brain barrier and to exert structural and functional effects that hold promises for neuroprotection/neurotrophism.

Brain-Derived Neurotrophic Factor and Nerve Growth Factor Therapeutics for Brain Injury: The Current Translational Challenges in Preclinical and Clinical Research

Ischemic stroke and traumatic brain injury (TBI) are among the leading causes of death and disability worldwide with impairments ranging from mild to severe. Many therapies are aimed at improving functional and cognitive recovery by targeting neural repair but have encountered issues involving efficacy and drug delivery. As a result, therapeutic options for patients are sparse. Neurotrophic factors are one of the key mediators of neural plasticity and functional recovery. Neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) serve as potential therapeutic options to increase neural repair and recovery as they promote neuroprotection and regeneration. BDNF and NGF have demonstrated the ability to improve functional recovery in preclinical and to a lesser extent clinical studies. Direct and indirect methods to increase levels of neurotrophic factors in animal models have been successful in improving postinjury outcome measures. However, the translation of these studies into clinical trials has been limited. Preclinical experiments have largely failed to result in significant impacts in clinical research. This review will focus on the administration of these neurotrophic factors in preclinical and clinical stroke and TBI and the challenges in translating these therapies from the bench to the clinic.

Treatment with platelet-rich plasma attenuates proprioceptor abnormalities in a rat model of postpartum stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is the most prevalent form of urinary incontinence, and vaginal delivery is a major risk factor for developing SUI. We evaluated the hypothesis that applying the autologous platelet rich plasma (PRP) to the pelvic floor muscles via injection affects expression of proprioceptors and improves postpartum stress urinary incontinence (PSUI) in rats.

METHODS

Virgin female Sprague-Dawley rats were divided into control (n = 10) and experimental group(n = 20). Vaginal dilation was used to establish PSUI, and the rats in the experimental group were further divided into the PSUI group (n = 10) and PSUI+PRP group (n = 10). Pelvic floor muscles from rats in the PSUI+PRP group were positioned under ultrasound guidance for PRP injection. The morphology and number of pelvic floor muscle spindles were assessed using H&E staining, proprioceptors evaluated by gold chloride staining, and changes in the expression of neurotrophin-3 (NT-3) and skeletal myosin MY-32 determined by immunohistochemistry.

RESULTS

After 28 days,bladder leak point pressure (BLPP) and abdominal leaking-urine point pressure (ALPP) in rats with PSUI were significantly lower than in control animals (P<0.01). Both BLPP and ALPP increased significantly in the PSUI+PRP group (P<0.01). Compared with the control group, muscle spindle morphology and structure in the PSUI and PSUI+PRP groups had different pathological changes,with higher variations in the PSUI group. The positive signals for NT-3/MY-32 expression in control rats were higher than those from PSUI or PSUI+PRP groups, however, the expression for NT-3/MY-32 in PSUI+PRP animals was higher than that seen in the PSUI group (P < 0.01).

CONCLUSIONS

PSUI rats have an abnormal expression of pelvic proprioceptors, which affect proprioceptive function, and further the contractibility of pelvic floor muscles. A PRP injection may restore the sensory function of pelvic proprioceptors, thus improving urine leakage in PSUI rats.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Positive Modulator of HGF/MET, Fosgonimeton, in Healthy Volunteers and Subjects with Alzheimer's Disease: Randomized, Placebo-Controlled, Double-Blind, Phase I Clinical Trial

Background:

Fosgonimeton (ATH-1017) is being developed as a first-in-class regenerative therapy for people with Alzheimer’s disease (AD) and dementia; potentially improving dementia symptoms and altering disease progression by reversing synaptic disconnection and neuronal loss.

Objective:

This randomized, double-blind, placebo-controlled phase I trial (NCT03298672) evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of fosgonimeton.

Methods:

Fosgonimeton was administered once daily via subcutaneous injection to 88 subjects. The single ascending dose study enrolled healthy young male subjects (n = 48; age, 33.4±6.3 years; dose, 2, 6, 20, 40, 60, or 90 mg); the multiple ascending dose study enrolled healthy elderly subjects (n = 29; age, 63.8±4.0 years; dose, 20, 40, 60, or 80 mg; 9-day duration); and the fixed-dose study enrolled AD subjects (n = 11; age, 69.2±7.1 years; dose, 40 mg; 9-day duration). Quantitative electroencephalogram (qEEG) and event-related potential (ERP) P300 measured neurophysiological signals following fosgonimeton treatment, supporting brain penetration and target engagement.

Results:

Fosgonimeton and placebo were shown to be safe and well-tolerated across all doses. Pharmacokinetic results for fosgonimeton were dose-proportional, with no sex effect or accumulation over 9 days. The main effect of fosgonimeton on qEEG was acute and sustained gamma power induction. In AD subjects, there was a significant effect toward ERP P300 latency normalization compared with placebo (p = 0.027; n = 7 at 40 mg fosgonimeton versus n = 4 placebo).

Conclusion:

These results support the continued development of fosgonimeton as a novel therapeutic for people with AD and dementia. The fast-onset normalization of ERP P300 latency in AD subjects suggests enhancement of synaptic function and potential procognitive effects.

A Prognostic Model for Predicting Tumor Mutation Burden and Tumor-Infiltrating Immune Cells in Bladder Urothelial Carcinoma

Tremendous progress has been made in development of immunotherapeutic approaches for treatment of bladder urothelial carcinoma (BLCA). However, efficacy and safety of these approaches remain unsatisfactory, necessitating further investigations for identification of indicators for predicting prognosis and efficacy. In this study, we downloaded transcriptomic and clinical data of BLCA patients from The Cancer Genome Atlas (TCGA) database, and identified differentially expressed genes (DEGs) between tumor and normal tissues. We incorporated these DEGs in an intersection analysis with immune-related genes (IRGs) obtained from the Immunology Database and Analysis Portal (ImmPort) database, and identified immune-related DEGs. These genes were subjected to Cox and least absolute shrinkage and selection operator (LASSO) regression analyses, then a prognostic model containing AHNAK, OAS1, NGF, PPY and SCG2 genes was constructed, for prediction of prognosis of BLCA and efficacy of immunotherapy. Finally, we explored the relationship between the prognostic model and tumor mutational burden (TMB), abundance of tumor-infiltrating immune cells (TICs) and immunotherapeutic targets, and found that patients with higher risk score (RS) had poorer prognosis and significantly lower levels of TMB. Patients in the low-RS group exhibited higher numbers of lymphoid cells, whereas those in the high-RS group exhibited higher proportions of myeloid cells. However, patients with high-RS tended to respond better to immunotherapy relative to those in the low-RS group. The constructed prognostic model provides a new tool for predicting prognosis of BLCA patients and efficacy of immunotherapy, offering a feasible option for management of the disease.

Carotenoids from Marine Sources as a New Approach in Neuroplasticity Enhancement

An increasing number of people experience disorders related to the central nervous system (CNS). Thus, new forms of therapy, which may be helpful in repairing processes' enhancement and restoring declined brain functions, are constantly being sought. One of the most relevant physiological processes occurring in the brain for its entire life is neuroplasticity. It has tremendous significance concerning CNS disorders since neurological recovery mainly depends on restoring its structural and functional organization. The main factors contributing to nerve tissue damage are oxidative stress and inflammation. Hence, marine carotenoids, abundantly occurring in the aquatic environment, being potent antioxidant compounds, may play a pivotal role in nerve cell protection. Furthermore, recent results revealed another valuable characteristic of these compounds in CNS therapy. By inhibiting oxidative stress and neuroinflammation, carotenoids promote synaptogenesis and neurogenesis, consequently presenting neuroprotective activity. Therefore, this paper focuses on the carotenoids obtained from marine sources and their impact on neuroplasticity enhancement.

Phase 1b Randomized Controlled Study of Short Course Topical Recombinant Human Nerve Growth Factor (rhNGF) for Neuroenhancement in Glaucoma: Safety, Tolerability, and Efficacy Measure Outcomes

PURPOSE

No approved therapies directly target retinal ganglion cells (RGCs) for neuroprotection or neuroenhancement in glaucoma. Recombinant human nerve growth factor (rhNGF) has been shown to promote RGC survival and function in animal models of optic neuropathy. Here we evaluate the safety, tolerability, and efficacy of short-term, high-dose rhNGF eye drops versus placebo in a cohort of glaucoma patients.

DESIGN

This was a prospective, phase 1b, single-center, randomized, double-masked, vehicle-controlled, parallel-group study.

METHODS

This study was designed to assess safety and tolerability as well as short-term neuroenhancement of structure and function (clinicaltrials.gov NCT02855450). A total of 60 open-angle glaucoma patients were randomized 40:20 to receive either 180 μg/mL rhNGF or vehicle control eye drops in both eyes, 3 times daily for 8 weeks, with a 24-week post-treatment follow-up. One eye was officially selected as the study eye, although both eyes were studied and dosed. Primary endpoints were safety, as assessed by adverse events, and tolerability, as assessed by patient-reported outcomes. Secondary outcome measures included best corrected visual acuity (BCVA), Humphrey visual field, electroretinograpy (ERG), and optical coherence tomography (OCT) of retinal nerve fiber layer (RNFL) thickness at baseline, after 8 weeks of treatment, and at 4 and 24 weeks after treatment (12 and 32 weeks total).

RESULTS

Of the 60 randomized patients, 23 were female (38%) and the average age was 66.1 years. Through week 32, there were no treatment-related serious adverse events, including no unexpectedly severe progression of optic neuropathy, no adverse events affecting ocular function or pressure, and no drug-related systemic toxicity. Topical high-dose rhNGF was tolerated well, with a low level of symptom burden mainly eliciting periocular ache (in 52% of treated group and 5% of placebo group) and only 3 patients (7.5%) discontinuing treatment because of discomfort, of whom 1 patient (2.5%) prematurely withdrew from the study. There were no statistically significant differences in global indices of Humphrey visual field and no meaningful differences in total, quadrant, or clock-hour mean RNFL thickness between the groups, although both of these function and structure measures showed nonsignificant trends toward significance in favor of rhNGF. Real-world participant data was used to generate an estimate of cohort size needed to power subsequent studies.

CONCLUSIONS

Use of rhNGF is safe and tolerable in a topical 180-μg/mL formulation. Although no statistically significant short-term neuroenhancement was detected in this trial, given the strong effects of NGF in preclinical models and the trends detected in this study, analysis for efficacy in a neuroprotection trial is warranted. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Tazarotene gel promotes healing of deep tissue injury in mice

We investigated the efficacy and molecular mechanisms of tazarotene gel for healing deep tissue injury (DTI). We used male C57BL/6J mice to establish a DTI model. Animals were divided randomly into control, tazarotene gel and purilon gel groups. We injected 100 ul tazarotene gel, purilon gel or saline every 48 h for 20 days. Hematoxylin and eosin staining was used to observe pathological changes on days 14 and 21. The mRNA and protein expression of VEGF-α, TGF-β1 and HIF-1α were detected by qRT-PCR and western blot, respectively. Wound sites exhibited accelerated healing by 20 days in the tazarotene gel group. Fewer inflammatory cells and more granulation tissue were found in both experimental groups compared to controls. The mRNA and protein expression of VEGF-α and TGF-β1 in the experimental groups were increased compared to the control group by day 14. Expression of HIF-1α in the experimental groups was significantly less than in the controls. Tazarotene gel promoted wound healing independent of the HIF-1α/VEGF signalling pathway during tissue repair of DTI. Tazarotene and purilon gels exhibited similar macroscopic healing of wounds and expression of genes and proteins.