Features of Remyelination after Transplantation of Olfactory Ensheathing Cells with Neurotrophic Factors into Spinal Cord Cysts.

This paper shows for the first time that co-transplantation of human olfactory ensheathing cells with neurotrophin-3 into spinal cord cysts is more effective for activation of remyelination than transplantation of cells with brain-derived neurotrophic factor and a combination of these two factors. The studied neurotrophic factors do not affect proliferation and migration of ensheathing cells in vitro. It can be concluded that the maximum improvement of motor function in rats receiving ensheathing cells with neurotrophin-3 is largely determined by activation of remyelination.

In vitro and in vivo characterization of human serum albumin-based PEGylated nanoparticles for BDNF and NT3 codelivery.

The utilization of neurotrophins in medicine shows significant potential for addressing neurodegenerative conditions, such as age-related macular degeneration (AMD). However, the therapeutic use of neurotrophins has been restricted due to their short half-life. Here, we aimed to synthesize PEGylated nanoparticles based on electrostatic-driven interactions between human serum albumin (HSA), a carrier for adsorption; neurotrophin-3 (NT3); and brain-derived neurotrophic factor (BDNF). Electrophoretic (ELS) and multi-angle dynamic light scattering (MADLS) revealed that the PEGylated HSA-NT3-BDNF nanoparticles ranged from 10 to 430 nm in diameter and exhibited a low polydispersity index (<0.4) and a zeta potential of -8 mV. Based on microscale thermophoresis (MST), the estimated dissociation constant (Kd) from the HSA molecule of BDNF was 1.6 µM, and the Kd of NT3 was 732 µM. The nanoparticles were nontoxic toward ARPE-19 and L-929 cells in vitro and efficiently delivered BDNF and NT3. Based on the biodistribution of neurotrophins after intravitreal injection into BALB/c mice, both nanoparticles were gradually released in the mouse vitreous body within 28 days. PEGylated HSA-NT3-BDNF nanoparticles stabilize neurotrophins and maintain this characteristic in vivo. Thus, given the simplicity of the system, the nanoparticles may enhance the treatment of a variety of neurological disorders in the future.

Encapsulation of the growth factor neurotrophin-3 in heparinised poloxamer hydrogel stabilises bioactivity and provides sustained release.

Poloxamer-based hydrogels show promise to stabilise and sustain the delivery of growth factors in tissue engineering applications, such as following spinal cord injury. Typically, growth factors such as neurotrophin-3 (NT-3) degrade rapidly in solution. Similarly, poloxamer hydrogels also degrade readily and are, therefore, only capable of sustaining the release of a payload over a small number of days. In this study, we focused on optimising a hydrogel formulation, incorporating both poloxamer 188 and 407, for the sustained delivery of bioactive NT-3. Hyaluronic acid blended into the hydrogels significantly reduced the degradation of the gel. We identified an optimal hydrogel composition consisting of 20 % w/w poloxamer 407, 5 % w/w poloxamer 188, 0.6 % w/w NaCl, and 1.5 % w/w hyaluronic acid. Heparin was chemically bound to the poloxamer chains to enhance interactions between the hydrogel and the growth factor. The unmodified and heparin-modified hydrogels exhibited sustained release of NT-3 for 28 days while preserving the bioactivity of NT-3. Moreover, these hydrogels demonstrated excellent cytocompatibility and had properties suitable for injection into the intrathecal space, underscoring their suitability as a growth factor delivery system. The findings presented here contribute valuable insights to the development of effective delivery strategies for therapeutic growth factors for tissue engineering approaches, including the treatment of spinal cord injury.

The effects of 12 weeks resistance training and vitamin D administration on neuromuscular joint, muscle strength and power in postmenopausal women.

BACKGROUND: This study aimed to examine the effects of 12 weeks of resistance training (RT) and vitamin D (VitD) supplementation on muscle strength and C-terminal agrin fragment (CAF) and Neurotrophin-3 (NT-3) concentrations as potential biomarkers in postmenopausal women. METHODS: This was a randomized double-blind placebo-controlled study. Forty-four healthy postmenopausal women (55.84 ± 4.70 years and 29.61 ± 4.26 kg/m2) were randomly assigned into four groups: (1) Resistance training + placebo (RT + PLA), (2) Vitamin D supplementation (VitD), (3) Resistance training + vitamin D (RT + VitD), and (4) Placebo (PLA). VitD was supplemented as an oral capsule containing 50000 IU of cholecalciferol every two weeks. RT involved leg press, chest press, leg extension, leg curl, and shoulder press exercises, performed with 3-4 sets at 70-85 % of 1RM, three times a week. RESULTS: Circulating levels of CAF and NT-3 did not significantly change following the intervention period in the study groups (p > 0.05). There were significant increases in upper and lower body muscle strength and power for RT + VitD and RT + PLA ( < 0.05), but not for VitD or PLA (p > 0.05). The muscle function gains for RT + VitD and RT + PLA were higher than those for VitD and PLA but did not differ between them. CONCLUSION: 12-week of RT interventions resulted in significant increases in muscle strength and power in postmenopausal women. However, VitD supplementation did not result in any additional benefits. The positive changes in muscle function promoted by RT do not seem to be associated with changes in the neuromuscular joint via the CAF or NT-3 as potential biomarkers.

Antidiabetic Effect of a New Original NT-3 Dipeptide Mimetic.

It was previously established that the original dipeptide mimetic of the 4th loop of NT-3, hexamethylenediamide bis-(N-monosuccinyl-L-asparaginyl-L-asparagine) (GTS-301), has a pronounced neuroprotective effect in vitro at concentrations of 10-5-10-12 М. In the present study, experiments on the streptozotocin-induced diabetes model in C57Bl/6 mice showed that GTS-301, when administered intraperitoneally for 32 days at doses of 0.1 and 0.5 mg/kg, has antidiabetic activity manifested in a reduction of hyperglycemia and polydipsia and in an increase in animal survival. The results obtained confirm the concept of the similarity of neurochemical mechanisms underlying the regulation of functions of neurons and ß-cells.

Analysis of influencing factors of anxiety and depression in maintenance hemodialysis patients and its correlation with BDNF, NT-3 and 5-HT levels.

Objective: The aim of this study is to examine the factors that contribute to anxiety and depression in individuals undergoing maintenance hemodialysis (MHD), as well as their association with serum levels of brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and serotonin (5-HT). Methods: In May 2020 and June 2022, 120 MHD patients who received MDH treatment at our hospital were enrolled. The control group was composed of 60 healthy adults (>18) who completed the physical examination at the same time. The serum levels of BDNF, NT-3, and 5-HT in patients and clinical data of MHD patients with different degrees of anxiety and depression were compared. The Pearson correlation was used to evaluate the correlation between anxiety and depression scores and serum BDNF, NT-3,5-HT levels in patients with MHD. Multivariate analysis was employed to analyze the risk factors of anxiety and depression in MHD patients. Results: The incidence of anxiety and depression in 120 MHD patients was 34.17% (41/120) and 64.17% (77/120), respectively. The levels of serum NT-3 and 5-HT in the anxiety group were higher than those in the non-anxiety and control group, and the levels of serum NT-3 in the non-anxiety group were higher than those in the control group (P < 0.05). The levels of serum BDNF, NT-3 and 5-HT in the depressed group were higher than those in the non-depressed group and control group, and the levels of serum NT-3 in the non-depressed group were higher than those in the control group (P < 0.05). SAS score was positively correlated with serum NT-3 and 5-HT levels, while the SDS score was negatively correlated with serum BDNF and positively correlated with serum NT-3 and 5-HT levels. Female, rural household registration, and restless leg syndrome were independent risk variables for anxiety in patients with MHD (P < 0.05). Rural household registration, economic deterioration, fatigue, insomnia, and vascular pain were independent variables of depression risk in patients with MHD. Conclusion: Anxiety and depression in patients with MHD are closely related to the levels of serum BDNF, NT-3, and 5-HT. Female, rural household registration, more than eight dialysis times/month, insomnia, and restless leg syndrome are the risk factors for anxiety in patients with MHD. Rural household registration, economic deterioration, fatigue, insomnia, and vascular pain are the risk factors for depression in patients with MHD. The clinical implication of these findings suggests that these indexes may perhaps serve as biological indicators of anxiety and depression amongst patients undergoing MHD. Such investigation can hence contribute to early detection, monitoring, and potentially enable the depiction of novel therapeutic strategies for managing these adverse states.

The Impact of Serum Protein Adsorption on PEGylated NT3-BDNF Nanoparticles-Distribution, Protein Release, and Cytotoxicity in a Human Retinal Pigmented Epithelial Cell Model.

The adsorption of biomolecules on nanoparticles' surface ultimately depends on the intermolecular forces, which dictate the mutual interaction transforming their physical, chemical, and biological characteristics. Therefore, a better understanding of the adsorption of serum proteins and their impact on nanoparticle physicochemical properties is of utmost importance for developing nanoparticle-based therapies. We investigated the interactions between potentially therapeutic proteins, neurotrophin 3 (NT3), brain-derived neurotrophic factor (BDNF), and polyethylene glycol (PEG), in a cell-free system and a retinal pigmented epithelium cell line (ARPE-19). The variance in the physicochemical properties of PEGylated NT3-BDNF nanoparticles (NPs) in serum-abundant and serum-free systems was studied using transmission electron microscopy, atomic force microscopy, multi-angle dynamic, and electrophoretic light scattering. Next, we compared the cellular response of ARPE-19 cells after exposure to PEGylated NT3-BDNF NPs in either a serum-free or complex serum environment by investigating protein release and cell cytotoxicity using ultracentrifuge, fluorescence spectroscopy, and confocal microscopy. After serum exposure, the decrease in the aggregation of PEGylated NT3-BDNF NPs was accompanied by increased cell viability and BDNF/NT3 in vitro release. In contrast, in a serum-free environment, the appearance of positively charged NPs with hydrodynamic diameters up to 900 nm correlated with higher cytotoxicity and limited BDNF/NT3 release into the cell culture media. This work provides new insights into the role of protein corona when considering the PEGylated nano-bio interface with implications for cytotoxicity, NPs' distribution, and BDNF and NT3 release profiles in the in vitro setting.

Overexpression of NT-3 in the hippocampus suppresses the early phase of the adult neurogenic process.

The dentate gyrus (DG) of the hippocampus regulates stress-related emotional behaviors and ensures neurogenesis throughout life. Neurotrophin-3 (NT-3) is a neurotrophic factor that regulates neuronal differentiation, survival, and synaptic formation in both the peripheral and central nervous systems. NT-3 is expressed in the adult DG of the hippocampus; several chronic stress conditions enhance NT-3 expression in rodents. However, functional modulation of the adult DG by NT-3 signaling remains unclear. To directly investigate the impact of NT-3 on DG function, NT-3 was overexpressed in the hippocampal ventral DG by an adeno-associated virus carrying NT-3 (AAV-NT-3). Four weeks following the AAV-NT-3 injection, high NT-3 expression was observed in the ventral DG. We examined the influence of NT-3 overexpression on the neuronal responses and neurogenic processes in the ventral DG. NT-3 overexpression significantly increased the expression of the mature DG neuronal marker calbindin and immediate early genes, such as Fos and Fosb, thereby suggesting DG neuronal activation. During neurogenesis, the number of proliferating cells and immature neurons in the subgranular zone of the DG significantly decreased in the AAV-NT-3 group. Among the neurogenesis-related factors, Vegfd, Lgr6, Bmp7, and Drd1 expression significantly decreased. These results demonstrated that high NT-3 levels in the hippocampus regulate the activation of mature DG neurons and suppress the early phase of neurogenic processes, suggesting a possible role of NT-3 in the regulation of adult hippocampal function under stress conditions.

AAV1.NT-3 gene therapy in the SOD1KO mouse model of accelerated sarcopenia.

BACKGROUND: Sarcopenia, an age-related loss of muscle mass, is a critical factor that affects the health of the older adults. The SOD1KO mouse is deficient of Cu/Zn superoxide dismutase, used as an accelerated aging model. We previously showed that NT-3 improves muscle fibre size by activating the mTOR pathway, suggesting a potential for attenuating age-related muscle loss. This study assessed the therapeutic efficacy of AAV1.NT-3 in this accelerated aging model. METHODS: Twelve 6 months old SOD1KO mice were injected intramuscularly with a 1 × 1011 vg dose of AAV1.tMCK.NT-3, and 13 age-matched SOD1KO mice were used as controls. The treatment effect was evaluated using treadmill, rotarod and gait analyses as well as histological studies assessing changes in muscle fibre, and fibre type switch, in tibialis anterior, gastrocnemius, and triceps muscles, and myelin thickness by calculating G ratio in sciatic and tibial nerves. Molecular studies involved qPCR experiments to analyse the expression levels of mitochondrial and glycolysis markers and western blot experiments to assess the activity of mTORC1 pathway. RESULTS: Treatment resulted in a 36% (154.9 vs. 114.1; P < 0.0001) and 76% increase (154.3 vs. 87.6; P < 0.0001) in meters ran, with treadmill test at 3 and 6 months post gene delivery. In addition, the treated cohort stayed on rotarod 30% (52.7 s vs. 40.4 s; P = 0.0095) and 54% (50.4 s vs. 32.7 s; P = 0.0007) longer, compared with untreated counterparts at 3 and 6 months post injection. Gait analysis, performed at endpoint, showed that stride width was normalized to wild type levels (29.3 mm) by an 11% decrease, compared with untreated cohort (28.6 mm vs. 32.1 mm; P = 0.0014). Compared with wild-type, SOD1KO mice showed 9.4% and 11.4% fibre size decrease in tibialis anterior and gastrocnemius muscles, respectively, which were normalized to wild type levels with treatment. Fibre diameter increase was observed prominently in FTG fibre type. G ratio analysis revealed hypomyelination in the tibial (0.721) and sciatic (0.676) nerves of SOD1KO model, which was reversed in the NT-3 cohort (0.646 and 0.634, respectively). Fibre size increase correlated with the increase in the p-S6 and p-4E-BP1 levels, and in the glycolysis markers in tibialis anterior. Alterations observed in the mitochondrial markers were not rescued with treatment. Overall, response to NT-3 was subdued in gastrocnemius muscle. CONCLUSIONS: This study shows that AAV1.NT-3 gene therapy protected SOD1KO mouse from accelerated aging effects functionally and histologically. We further confirmed that NT-3 has potential to activate the mTOR and glycolytic pathways in muscle.

Plasma levels of neurotrophin 4/5, NGF and pro-BDNF influence transition to mental disorders in a sample of individuals at ultra-high risk for psychosis.

BACKGROUND: Neurotrophins (NTs) and their precursors (pro-NTs) are polypeptides with important roles in neuronal development, differentiation, growth, survival and plasticity, as well as apoptosis and neuronal death. Imbalance in NT levels were observed in schizophrenia spectrum disorders, but evidence in ultra-high risk for psychosis (UHR) samples is scarce. METHODS: A naturalistic sample of 87 non-help-seeking UHR subjects and 55 healthy controls was drawn from the general population. Blood samples were collected and NT-3, NT-4/5, BDNF, pro-BDNF, NGF, pro-NGF were analyzed through enzyme linked immunosorbent assay (ELISA). Information on cannabis and tobacco use was also collected. Logistic regression models and path analysis were used to control for confounders (tobacco, age, cannabis use). RESULTS: NT-4/5 was significantly decreased, and pro-BDNF was significantly increased in UHR individuals compared to controls. Cannabis use and higher NGF levels were significantly related to transition to psychiatric disorders among UHR subjects. Increased pro-BDNF and decreased NT-4/5 influenced transition by the mediation of perceptual abnormalities. CONCLUSIONS: Our study shows for the first time that NTs are altered in UHR compared to healthy control individuals, and that they can be a predictor of transition to psychiatric illnesses in this population. Future studies should employ larger naturalistic samples to confirm the findings.

NT-3 Combined with TGF-ß Signaling Pathway Enhance the Repair of Spinal Cord Injury by Inhibiting Glial Scar Formation and Promoting Axonal Regeneration.

This study investigated the mechanism of neurotrophin-3 (NT-3) in promoting spinal cord injury repair through the transforming growth factor-beta (TGF-ß) signaling pathway. A mouse model of spinal cord injury was established. Forty C57BL/6J mice were randomized into model, NT-3, NT-3 + TGF-ß1 and NT-3 + LY364947 groups. The Basso-Beattie-Bresnahan (BBB) scores of the NT-3 and NT-3 + LY364947 groups were significantly higher than the model group. The BBB score of the NT-3 + TGF-ß1 group was significantly lower than NT-3 group. Hematoxylin-eosin staining and transmission electron microscopy showed reduction in myelin sheath injury, more myelinated nerve fibers in the middle section of the catheter, and relatively higher density and more neatly arranged regenerated axons in the NT-3 and NT-3 + LY364947 groups compared with the model and NT-3 + TGF-ß1 groups. Immunofluorescence, TUNEL and Western blot analysis showed that compared with model group, the NEUN expression increased, and the apoptosis and Col IV, LN, CSPG, tenascin-C, Sema 3 A, EphB2 and Smad2/3 protein expression decreased significantly in the NT-3 and NT-3 + LY364947 groups; the condition was reversed in the NT-3 + TGF-ß1 group compared with the NT-3 group. NT-3 combined with TGF-ß signaling pathway promotes astrocyte differentiation, reduces axon regeneration inhibitory molecules, apoptosis and glial scar formation, promotes axon regeneration, and improves spinal cord injury.

Detection and Quantification of Neurotrophin-3 (NT-3) and Nerve Growth Factor (NGF) Levels in Early Second Trimester Amniotic Fluid: Investigation into a Possible Correlation with Abnormal Fetal Growth Velocity Patterns.

BACKGROUND: Abnormal fetal growth is associated with adverse perinatal and long-term outcomes. The pathophysiological mechanisms underlying these conditions are still to be clarified. Nerve growth factor (NGF) and neurotrophin-3 (NT-3) are two neurotrophins that are mainly involved in the neuroprotection process, namely promotion of growth and differentiation, maintenance, and survival of neurons. During pregnancy, they have been correlated with placental development and fetal growth. In this study, we aimed to determine the early 2nd trimester amniotic fluid levels of NGF and NT-3 and to investigate their association with fetal growth. METHODS: This is a prospective observational study. A total of 51 amniotic fluid samples were collected from women undergoing amniocentesis early in the second trimester and were stored at -80 °C. Pregnancies were followed up until delivery and birth weight was recorded. Based on birth weight, the amniotic fluid samples were divided into three groups: appropriate for gestational age (AGA), small for gestational age (SGA), and large for gestational age (LGA). NGF and NT-3 levels were determined by using Elisa kits. RESULTS: NGF concentrations were similar between the studied groups; median values were 10.15 pg/mL, 10.15 pg/mL, and 9.14 pg/mL in SGA, LGA, and AGA fetuses, respectively. Regarding NT-3, a trend was observed towards increased NT-3 levels as fetal growth velocity decreased; median concentrations were 11.87 pg/mL, 15.9 pg/mL, and 23.5 pg/mL in SGA, AGA, and LGA fetuses, respectively, although the differences among the three groups were not statistically significant. CONCLUSIONS: Our findings suggest that fetal growth disturbances do not induce increased or decreased production of NGF and NT-3 in early second trimester amniotic fluid. The trend observed towards increased NT-3 levels as fetal growth velocity decreased shows that there may be a compensatory mechanism in place that operates in conjunction with the brain-sparing effect. Further associations between these two neurotrophins and fetal growth disturbances are discussed.

In Vitro Effects of Photon Beam and Carbon Ion Radiotherapy on the Perineural Invasion of Two Cell Lines of Neurotropic Tumours.

Primary mucosal melanoma (PMM) and pancreatic ductal adenocarcinoma (PDAC) are two aggressive malignancies, characterized by intrinsic radio-chemoresistance and neurotropism, a histological feature resulting in frequent perineural invasion (PNI), supported by neurotrophic factors secreted in the tumour microenvironment (TME), such as neurotrophin-3 (NT-3). Carbon-ion radiotherapy (CIRT) could represent an effective option in unresectable PMM and PDAC. Only a few data about the effects of CIRT on PNI in relation to NT-3 are available in the literature, despite the numerous pieces of evidence revealing the peculiar effects of this type of radiation on tumour cell migration. This in vitro study investigated for the first time the response of PMM and PDAC cells to NT-3 and evaluated the effects of conventional photon beam radiotherapy (XRT) and CIRT on cell viability, proliferation, and migration. Our results demonstrated the greater capacity of C-ions to generally decrease cell viability, proliferation, and migration, while the addition of NT-3 after both types of irradiation determined an increase in these features, maintaining a dose-dependent trend and acting more effectively as a chemoattractant than inductor in the case of migration.

Influence of chrysin on D-galactose induced-aging in mice: Up regulation of AMP kinase/liver kinase B1/peroxisome proliferator-activated receptor-γ coactivator 1-α signaling pathway.

Adenosine monophosphate kinase/liver kinase B1/peroxisome proliferator-activated receptor-γ coactivator 1-α (AMPK/LKB1/PGC1α) pathway has a vital role in regulating age-related diseases. It controls neurogenesis, cell proliferation, axon outgrowth, and cellular energy homeostasis. AMPK pathway also regulates mitochondrial synthesis. The current study evaluated the effect of chrysin on D-galactose (D-gal) induced-aging, neuron degeneration, mitochondrial dysfunction, oxidative stress, and neuroinflammation in mice. The mice were allocated randomly into four groups (10 each group): Group 1: normal control group, Group 2: D-gal group, Groups 3 and 4: chrysin (125 and 250 mg/kg, respectively). Groups 2-4 were injected with D-gal (200 mg/kg/day; s.c) for 8 weeks to induce aging. Groups 3 and 4 were orally gavaged every day concurrent with D-gal. At the end of experiment, behavioral, brain biochemical and histopathological changes were monitored. Chrysin administration elevated discrimination ratio in object recognition, Y Maze percentage alternation, locomotor activity and brain contents of AMPK, LKB1, PGC1α, NAD (P)H quinone oxidoreductase 1 (NQO1), heme oxygenase 1 (HO-1), nerve growth factor (NGF) (neurotrophin-3; NT-3), and seretonin as well as reduced brain contents of tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), advanced glycation end products (AGEs) and glial fibrillary acidic protein (GFAP) compared to D-gal-treated mice. Chrysin also alleviated cerebral cortex and white matter neurons degeneration. Chrysin protects against neurodegeneration, improves mitochondrial autophagy and biogenesis as well as activates antioxidant genes expression. In addition, chrysin ameliorates neuroinflammation and stimulates the release of NGF and serotonin neurotransmitter. So, chrysin has a neuroprotective effect in D-gal induced-aging in mice.

AAV1.NT-3 gene therapy prevents age-related sarcopenia.

Sarcopenia is progressive loss of muscle mass and strength, occurring during normal aging with significant consequences on the quality of life for elderly. Neurotrophin 3 (NT-3) is an important autocrine factor supporting Schwann cell survival and differentiation and stimulating axon regeneration and myelination. NT-3 is involved in the maintenance of neuromuscular junction (NMJ) integrity, restoration of impaired radial growth of muscle fibers through activation of the Akt/mTOR pathway. We tested the efficacy of NT-3 gene transfer therapy in wild type (WT)-aged C57BL/6 mice, a model for natural aging and sarcopenia, via intramuscular injection 1 × 1011 vg AAV1.tMCK.NT-3, at 18 months of age. The treatment efficacy was assessed at 6 months post-injection using run to exhaustion and rotarod tests, in vivo muscle contractility assay, and histopathological studies of the peripheral nervous system, including NMJ connectivity and muscle. AAV1.NT-3 gene therapy in WT-aged C57BL/6 mice resulted in functional and in vivo muscle physiology improvements, supported by quantitative histology from muscle, peripheral nerves and NMJ. Hindlimb and forelimb muscles in the untreated cohort showed the presence of a muscle- and sex-dependent remodeling and fiber size decrease with aging, which was normalized toward values obtained from 10 months old WT mice with treatment. The molecular studies assessing the NT-3 effect on the oxidative state of distal hindlimb muscles, accompanied by western blot analyses for mTORC1 activation were in accordance with the histological findings. Considering the cost and quality of life to the individual, we believe our study has important implications for management of age-related sarcopenia.

Evaluation of the effect of mesenchymal stem cells injection in the nucleus accumbens on the morphine reinstatement behavior in a conditioned place preference model in Wistar rat: Expression changes of NMDA receptor subunits and NT-3.

Mesenchymal stem cells (MSCs) have been recently shown to improve functional recovery in animal models of CNS disorders and are currently being examined in clinical studies for sclerosis, stroke, and CNS lesions. The activation of endogenous CNS protection and repair mechanisms is unclear. MSC-based approaches are considered a new potential target for neurodegenerative disorders. This study was designed to discover the effect of MSCs injection in the nucleus accumbens (NAc) on the reinstatement of behavior in morphine-induced conditioned place preference (CPP) in male rats. The CPP was induced via intra-peritoneal (i.p.) morphine injection (5 mg/kg) for three consecutive days. After being tested for CPP induction, animals received MSCs or culture medium (DMEM F-12) in their NAc using stereotaxic surgery. Following extinction, a priming dose of morphine (2 mg/kg) was administered to induce reinstatement. Expression of GluN1, GluN2A, and GluN2B subunits of the NMDA receptor and the NT-3 gene in the NAc was assessed on the last day of extinction and following CPP reinstatement. The results showed that local injection of MSCs attenuated reinstatement after receiving a priming dose of morphine, and also shortened the period of CPP extinction. The mRNA expression of the NT-3 gene in the group receiving MSCs was increased compared to control animals, as was observed for GluN1 and GluN2B, but not GluN2A. It is concluded that intra-NAc injection of MSCs may facilitate morphine extinction and alleviate reinstatement behavior which may be via expression changes in NMDA receptor subunits and NT-3 gene.

Barrier-penetrating liposome targeted delivery of basic fibroblast growth factor for spinal cord injury repair.

Nanoparticle technologies offer a non-invasive means to deliver basic fibroblast growth factor (bFGF) for the treatment of spinal cord injury (SCI). However, the inability of bFGF to accumulate at the injury site and inefficient penetration across the blood-spinal cord barrier (BSCB) remain challenges. The present study describes a dual-targeting liposome (bFGF@Lip-Cp&Rp) with injury lesion targeting and BSCB-penetrating capability to deliver bFGF for SCI treatment. The CAQK peptide (Cp) with injury lesion targeting ability and R2KC peptide (Rp) with BSCB-penetrating capability were grafted onto the liposomes for a flexible and non-invasive drug delivery systems preparation. Results exhibit that the dual-targeted liposomes could significantly cross the BSCB and accumulate at the injury site. During the early stage of SCI, bFGF@Lip-Cp&Rp promotes repair of BSCB and facilitates M2-polarization of macrophages. Regular delivery of bFGF@Lip-Cp&Rp increase HUVECs tube formation and angiogenesis, ameliorate the microenvironment of lesion site, suppress the neuronal apoptosis and axonal atrophy in SCI rats. Importantly, continuous treatment of bFGF@Lip-Cp&Rp supports the restoration of limb motor function in SCI rats. In summary, this research implies that the injury site-targeting and BSCB-penetrating liposomes could be a promising therapeutic approach for the treatment of SCI.

Overexpression of NT3P75-2 gene modified bone marrow mesenchymal stem cells supernatant promotes neurological function recovery in ICH rats.

Intracerebral hemorrhage (ICH) is an acute cerebrovascular disease with high mortality and long-term disability rates. Stem cell transplantation and neurotrophic factor therapy have shown great potential in ICH. It has been established that mutated NT3 (NT3P75 - 2) can enhance the positive biological functions of NT3 by decreasing its affinity to the P75-2 receptor. The present study aimed to explore whether NT3P75-2 could further improve neurological recovery after ICH. First, we constructed three stable BMSC cell lines (GFP, GFP-NT3 overexpressed and GFP-NT3P75 - 2 overexpressed) by lentivirus infection. Next, rats were injected with fresh supernatants of these three cell lines on days 1 (24 h) and 3 (72 h) post-ICH induction. Behavioral evaluations were conducted to assess the neurological recovery of ICH rats. We further evaluated changes in microglia activation, neuron survival and proliferation of neural stem cells. Compared with the GFP group and the GFP-NT3 group, animals in the GFP-NT3P75 - 2 group exhibited better motor function improvements and milder neuroinflammation response. Meanwhile, overexpression of NT3P75 - 2 significantly decreased neuronal apoptosis and increased number of SOX2 - positive cells. Taken together, our study demonstrated that early administration of NT3P75 - 2 enriched BMMSC supernatants significantly enhanced neuro-functional recovery after ICH by regulating neuroinflammation response, neuronal survival and increasing neural stem cell number, providing a new therapeutic strategy and direction for early treatment of ICH.

Proper wiring of newborn neurons to control bladder function after complete spinal cord injury.

Activation of endogenous neurogenesis by bioactive materials enables restoration of sensory/motor function after complete spinal cord injury (SCI) via formation of new relay neural circuits. The underlying wiring logic of newborn neurons in adult central nervous system (CNS) is unknown. Here, we report neurotrophin3-loaded chitosan biomaterial substantially recovered bladder function after SCI. Multiple neuro-circuitry tracing technologies using pseudorabies virus (PRV), rabies virus (RV), and anterograde adeno-associated virus (AAV), demonstrated that newborn neurons were integrated into the micturition neural circuits and reconnected higher brain centers and lower spinal cord centers to control voiding, and participated in the restoration of the lower urinary tract function, even in the absence of long-distance axonal regeneration. Opto- and chemo-genetic studies further supported the notion that the supraspinal control of the lower urinary tract function was partially recovered. Our data demonstrated that regenerated relay neurons could be properly integrated into disrupted long-range neural circuits to restore function of adult CNS.

Differential Effects of Somatostatin, Octreotide, and Lanreotide on Neuroendocrine Differentiation and Proliferation in Established and Primary NET Cell Lines: Possible Crosstalk with TGF-ß Signaling.

GEP-NETs are heterogeneous tumors originating from the pancreas (panNET) or the intestinal tract. Only a few patients with NETs are amenable to curative tumor resection, and for most patients, only palliative treatments to successfully control the disease or manage symptoms remain, such as with synthetic somatostatin (SST) analogs (SSAs), such as octreotide (OCT) or lanreotide (LAN). However, even cells expressing low levels of SST receptors (SSTRs) may exhibit significant responses to OCT, which suggests the possibility that SSAs signal through alternative mechanisms, e.g., transforming growth factor (TGF)-ß. This signaling mode has been demonstrated in the established panNET line BON but not yet in other permanent (i.e., QGP) or primary (i.e., NT-3) panNET-derived cells. Here, we performed qPCR, immunoblot analyses, and cell counting assays to assess the effects of SST, OCT, LAN, and TGF-ß1 on neuroendocrine marker expression and cell proliferation in NT-3, QGP, and BON cells. SST and SSAs were found to regulate a set of neuroendocrine genes in all three cell lines, with the effects of SST, mainly LAN, often differing from those of OCT. However, unlike NT-3 cells, BON cells failed to respond to OCT with growth arrest but paradoxically exhibited a growth-stimulatory effect after treatment with LAN. As previously shown for BON, NT-3 cells responded to TGF-ß1 treatment with induction of expression of SST and SSTR2/5. Of note, the ability of NT-3 cells to respond to TGF-ß1 with upregulation of the established TGF-ß target gene SERPINE1 depended on cellular adherence to a collagen-coated matrix. Moreover, when applied to NT-3 cells for an extended period, i.e., 14 days, TGF-ß1 induced growth suppression as shown earlier for BON cells. Finally, next-generation sequencing-based identification of microRNAs (miRNAs) in BON and NT-3 revealed that SST and OCT impact positively or negatively on the regulation of specific miRNAs. Our results suggest that primary panNET cells, such as NT-3, respond similarly as BON cells to SST, SSA, and TGF-ß treatment and thus provide circumstantial evidence that crosstalk of SST and TGF-ß signaling is not confined to BON cells but is a general feature of panNETs.