Factors that influence adult neurogenesis as potential therapy

Effects of one month of Common Yoga Protocol practice appear to be mediated by the angiogenic and neurogenic pathway: A pilot study

OBJECTIVE

To examine the molecular effects of mindful activities such as yoga and meditation DESIGN: This was an open label single arm exploratory yoga intervention study.

STUDY PARTICIPANTS

64 healthy individuals within the age of 18-60 years were recruited for this one month yoga intervention study.

INTERVENTION

Common Yoga Protocol (CYP) is a standardized yoga protocol released by Ministry of AYUSH, India for International Yoga Day. It includes all aspects of yoga i.e. asanas, pranayama and meditation. It is designed for adoption by all age groups for the health of community.

OUTCOME MEASURES

The participants were assessed for biochemical parameters including Fasting Sugar and Lipid profile. The molecular markers of neurogenesis (i.e. Brain derived Neurotropic Factor, BDNF) and Angiogenesis (i.e. Vascular Endothelial Growth Factor, VEGF and Angiogenin) along with Amyloid β (marker related to neuro-degenerative diseases) were assessed. All the assessments were made at baseline and after one month of the intervention.

RESULTS

After one month of CYP practice High Density Lipoprotein (HDL) levels increased significantly (p<0.001), although other biochemical parameters i.e. fasting sugar and other lipid assessments were found to be unaltered. Angiogenesis marker, angiogenin was increased significantly (p<0.002), other angiogenesis marker VEGF did not show any change along with BDNF, marker of neurogenesis. Amyloid β levels were also unaltered. Even though individual levels of VEGF and Amyloid β did not show any change, proportion of VEGF to Amyloid β showed a significant increase (p<0.001) after one month of CYP intervention indicating that the change in VEGF levels was significantly higher than the change in Amyloid β levels.

CONCLUSION

CYP practice may influence cell survival pathways mediated by angiogenic and neurogenic cross talk. Hence, CYP can be considered as a preventive measure for diseases associated with impaired angiogenic and neurogenic mechanism. This is the first study to examine the effects of CYP at the molecular level.

Phf21b imprints the spatiotemporal epigenetic switch essential for neural stem cell differentiation

Cerebral cortical development in mammals involves a highly complex and organized set of events including the transition of neural stem and progenitor cells (NSCs) from proliferative to differentiative divisions to generate neurons. Despite progress, the spatiotemporal regulation of this proliferation-differentiation switch during neurogenesis and the upstream epigenetic triggers remain poorly known. Here we report a cortex-specific PHD finger protein, Phf21b, which is highly expressed in the neurogenic phase of cortical development and gets induced as NSCs begin to differentiate. Depletion of Phf21b in vivo inhibited neuronal differentiation as cortical progenitors lacking Phf21b were retained in the proliferative zones and underwent faster cell cycles. Mechanistically, Phf21b targets the regulatory regions of cell cycle promoting genes by virtue of its high affinity for monomethylated H3K4. Subsequently, Phf21b recruits the lysine-specific demethylase Lsd1 and histone deacetylase Hdac2, resulting in the simultaneous removal of monomethylation from H3K4 and acetylation from H3K27, respectively. Intriguingly, mutations in the Phf21b locus associate with depression and mental retardation in humans. Taken together, these findings establish how a precisely timed spatiotemporal expression of Phf21b creates an epigenetic program that triggers neural stem cell differentiation during cortical development.

Systems biology reveals reprogramming of the S-nitroso-proteome in the cortical and striatal regions of mice during aging process

Cell aging depends on the rate of cumulative oxidative and nitrosative damage to DNA and proteins. Accumulated data indicate the involvement of protein S-nitrosylation (SNO), the nitric oxide (NO)-mediated posttranslational modification (PTM) of cysteine thiols, in different brain disorders. However, the changes and involvement of SNO in aging including the development of the organism from juvenile to adult state is still unknown. In this study, using the state-of-the-art mass spectrometry technology to identify S-nitrosylated proteins combined with large-scale computational biology, we tested the S-nitroso-proteome in juvenile and adult mice in both cortical and striatal regions. We found reprogramming of the S-nitroso-proteome in adult mice of both cortex and striatum regions. Significant biological processes and protein–protein clusters associated with synaptic and neuronal terms were enriched in adult mice. Extensive quantitative analysis revealed a large set of potentially pathological proteins that were significantly upregulated in adult mice. Our approach, combined with large scale computational biology allowed us to perform a system-level characterization and identification of the key proteins and biological processes that can serve as drug targets for aging and brain disorders in future studies.

Intermittent fasting promotes adult hippocampal neuronal differentiation by activating GSK-3β in 3xTg-AD mice

Moderate dietary restriction can ameliorate age-related chronic diseases such as Alzheimer's disease (AD) by increasing the expression of neurotrophic factors and promoting neurogenesis in the brain. Glycogen synthase kinase-3β (GSK-3β) signaling is essential for the coordination of progenitor cell proliferation and differentiation during brain development. The mechanisms by which GSK-3β is involved in dietary restriction-induced neurogenesis and cognitive improvement remain unclear. Six-month-old male 3xTg-AD and wild-type mice were fed on alternate days (intermittent fasting, IF) or ad libitum (AL) for 3 months. GSK-3β activity was regulated by bilaterally infusing lentiviral vectors carrying siRNA targeting GSK-3β into the dentate gyrus region of the hippocampus. Intermittent fasting promoted neuronal differentiation and maturation in the dentate gyrus and ameliorated recognized dysfunction in 3xTg-AD mice. These effects were reversed by siRNA targeting GSK-3β. After intermittent fasting, the insulin and protein kinase A signaling pathways were inhibited, while the adenosine monophosphate-activated protein kinase and brain-derived neurotrophic factor pathways were activated. These findings suggest that intermittent fasting can promote neuronal differentiation and maturation in the hippocampus by activating GSK-3β, thus improving learning and memory.

Intracranial alternating current stimulation facilitates neurogenesis in a mouse model of Alzheimer's disease

BACKGROUND

Neurogenesis is significantly impaired in the brains of both human patients and experimental animal models of Alzheimer's disease (AD). Although deep brain stimulation promotes neurogenesis, it is an invasive technique that may damage neural circuitry along the path of the electrode. To circumvent this problem, we assessed whether intracranial electrical stimulation to the brain affects neurogenesis in a mouse model of Alzheimer's disease (5xFAD).

METHODS AND RESULTS

We used Ki67, Nestin, and doublecortin (DCX) as markers and determined that neurogenesis in both the subventricular zone (SVZ) and hippocampus were significantly reduced in the brains of 4-month-old 5xFAD mice. Guided by a finite element method (FEM) computer simulation to approximately estimate current and electric field in the mouse brain, electrodes were positioned on the skull that were likely to deliver stimulation to the SVZ and hippocampus. After a 4-week program of 40-Hz intracranial alternating current stimulation (iACS), neurogenesis indicated by expression of Ki67, Nestin, and DCX in both the SVZ and hippocampus were significantly increased compared to 5xFAD mice who received sham stimulation. The magnitude of neurogenesis was close to the wild-type (WT) age-matched unmanipulated controls.

CONCLUSION

Our results suggest that iACS is a promising, less invasive technique capable of effectively stimulating the SVZ and hippocampus regions in the mouse brain. Importantly, iACS can significantly boost neurogenesis in the brain and offers a potential treatment for AD.

Cellular mechanisms and treatments for chemobrain: insight from aging and neurodegenerative diseases

Chemotherapy is a life-saving treatment for cancer patients, but also causes long-term cognitive impairment, or "chemobrain", in survivors. However, several challenges, including imprecise diagnosis criteria, multiple confounding factors, and unclear and heterogeneous molecular mechanisms, impede effective investigation of preventions and treatments for chemobrain. With the rapid increase in the number of cancer survivors, chemobrain is an urgent but unmet clinical need. Here, we leverage the extensive knowledge in various fields of neuroscience to gain insights into the mechanisms for chemobrain. We start by outlining why the post-mitotic adult brain is particularly vulnerable to chemotherapy. Next, through drawing comparisons with normal aging, Alzheimer's disease, and traumatic brain injury, we identify universal cellular mechanisms that may underlie the cognitive deficits in chemobrain. We further identify existing neurological drugs targeting these cellular mechanisms that can be repurposed as treatments for chemobrain, some of which were already shown to be effective in animal models. Finally, we briefly describe future steps to further advance our understanding of chemobrain and facilitate the development of effective preventions and treatments.

Prevention of Early Alzheimer's Disease by Erinacine A-Enriched Hericium erinaceus Mycelia Pilot Double-Blind Placebo-Controlled Study

OBJECTIVE

To investigate the efficacy and safety of three H. erinaceus mycelia (EAHE) capsules (350 mg/capsule; containing 5 mg/g erinacine A active ingredient) per day for the treatment of patients with mild Alzheimer's Disease (AD).

METHODS

This study comprised a 3-week no-drug screening period, followed by a 49-week double-blind treatment period with 2-parallel groups in which eligible patients were randomized to either three 5 mg/g EAHE mycelia capsules per day or identical appearing placebo capsules. Cognitive assessments, ophthalmic examinations, biomarker collection, and neuroimaging were followed throughout the study period.

RESULTS

After 49 weeks of EAHE intervention, a significant decrease in Cognitive Abilities Screening Instrument score was noted in the placebo group, a significant improvement in Mini-Mental State Examination score was observed in the EAHE group and a significant Instrumental Activities of Daily Living score difference were found between the two groups. In addition, EAHE group achieved a significantly better contrast sensitivity when compared to the placebo group. Moreover, only the placebo group observed significantly lowered biomarkers such as calcium, albumin, apolipoprotein E4, hemoglobin, and brain-derived neurotrophic factor and significantly elevated alpha1-antichymotrypsin and amyloid-beta peptide 1-40 over the study period. Using diffusion tensor imaging, the mean apparent diffusion coefficient (ADC) values from the arcuate fasciculus region in the dominant hemisphere significantly increased in the placebo group while no significant difference was found in the EAHE group in comparison to their baselines. Moreover, ADC values from the parahippocampal cingulum region in the dominant hemisphere significantly decreased in the EAHE group whereas no significant difference was found in the placebo group when compared to their baselines. Lastly, except for four subjects who dropped out of the study due to abdominal discomfort, nausea, and skin rash, no other adverse events were reported.

CONCLUSION

Three 350 mg/g EAHE capsules intervention for 49 weeks demonstrated higher CASI, MMSE, and IADL scores and achieved a better contrast sensitivity in patients with mild AD when compared to the placebo group, suggesting that EAHE is safe, well-tolerated, and may be important in achieving neurocognitive benefits.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT04065061.

Cacna1c haploinsufficiency lacks effects on adult hippocampal neurogenesis and volumetric properties of prefrontal cortex and hippocampus in female rats

The cross-disorder risk gene CACNA1C is strongly involved in the etiology of all major neuropsychiatric disorders, with women often being more affected by CACNA1C mutations than men. Human neuroimaging studies provided evidence that CACNA1C variants are associated with anatomical and functional brain alterations, such as decreased prefrontal volumes, microstructural changes in the hippocampus, and reduced hippocampal activity during memory tasks. In mouse models, Cacna1c alterations were repeatedly linked to disorder-like behavioral phenotypes and reduced adult hippocampal neurogenesis, which has been implicated in the pathology of neuropsychiatric disorders. Here, we applied a recently developed rat model and conducted two studies to investigate the effects of partial Cacna1c depletion on adult hippocampal neurogenesis and volumetric properties of the hippocampus and the prefrontal cortex in adult female constitutive heterozygous (Cacna1c^+/-) rats and wildtype (Cacna1c^+/+) littermate controls. In study 1, we analyzed proliferation versus survival of adult-born hippocampal cells based on a 5-bromodeoxyuridine assay ensuring neuronal cell-type specificity through applying an immunofluorescent multiple staining approach. In study 2, we performed a detailed volumetric analysis with high structural resolution of the dorsal hippocampus and the medial prefrontal cortex, including their major substructures. Our results indicate comparable levels of cell proliferation and neuronal survival in Cacna1c^+/- rats and Cacna1c^+/+ controls. Additionally, we found similar volumes of the dorsal hippocampus and the medial prefrontal cortex across major substructures irrespective of genotype, indicating that Cacna1c haploinsufficiency has no prominent effects on these brain features in female rats.

Induced pluripotent stem cells (iPSCs) as game-changing tools in the treatment of neurodegenerative disease: Mirage or reality?

Based on investigations, there exist tight correlations between neurodegenerative diseases' incidence and progression and aberrant protein aggregreferates in nervous tissue. However, the pathology of these diseases is not well known, leading to an inability to find an appropriate therapeutic approach to delay occurrence or slow many neurodegenerative diseases' development. The accessibility of induced pluripotent stem cells (iPSCs) in mimicking the phenotypes of various late-onset neurodegenerative diseases presents a novel strategy for in vitro disease modeling. The iPSCs provide a valuable and well-identified resource to clarify neurodegenerative disease mechanisms, as well as prepare a promising human stem cell platform for drug screening. Undoubtedly, neurodegenerative disease modeling using iPSCs has established innovative opportunities for both mechanistic types of research and recognition of novel disease treatments. Most important, the iPSCs have been considered as a novel autologous cell origin for cell-based therapy of neurodegenerative diseases following differentiation to varied types of neural lineage cells (e.g. GABAergic neurons, dopamine neurons, cortical neurons, and motor neurons). In this review, we summarize iPSC-based disease modeling in neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and Huntington's disease. Moreover, we discuss the efficacy of cell-replacement therapies for neurodegenerative disease.

Training on an Appetitive Trace-Conditioning Task Increases Adult Hippocampal Neurogenesis and the Expression of Arc, Erk and CREB Proteins in the Dorsal Hippocampus

Adult hippocampal neurogenesis (AHN) plays an essential role in hippocampal-dependent memory consolidation. Increased neurogenesis enhances learning, whereas its ablation causes memory impairment. In contrast, few reports suggest that neurogenesis reduces after learning. Although the interest in exploring the role of adult neurogenesis in learning has been growing, the evidence is still limited. The role of the trace- and delay-appetitive-conditioning on AHN and its underlying mechanism are not known. The consolidation of trace-conditioned memory requires the hippocampus, but delay-conditioning does not. Moreover, the dorsal hippocampus (DH) and ventral hippocampus (VH) may have a differential role in these two conditioning paradigms. Here, we have investigated the changes in: (A) hippocampal cell proliferation and their progression towards neuronal lineage; and (B) expression of Arc, Erk1, Erk2, and CREB proteins in the DH and VH after trace- and delay-conditioning in the rat. The number of newly generated cells significantly increased in the trace-conditioned but did not change in the delay-conditioned animals compared to the control group. Similarly, the expression of Arc protein significantly increased in the DH but not in the VH after trace-conditioning. Nonetheless, it remains unaltered in the delay-conditioned group. The expression of pErk1, pErk2, and pCREB also increased in the DH after trace-conditioning. Whereas, the expression of only pErk1 pErk2 and pCREB proteins increased in the VH after delay-conditioning. Our results suggest that appetitive trace-conditioning enhances AHN. The increased DH neuronal activation and pErk1, pErk2, and pCREB in the DH may be playing an essential role in learning-induced cell-proliferation after appetitive trace-conditioning.

Immunization with neural-derived peptides increases neurogenesis in rats with chronic spinal cord injury

Aims

Immunization with neural‐derived peptides (INDP) has demonstrated to be a promising therapy to achieve a regenerative effect in the chronic phase of the spinal cord injury (SCI). Nevertheless, INDP‐induced neurogenic effects in the chronic stage of SCI have not been explored.

Methods and Results

In this study, we analyzed the effect of INDP on both motor and sensitive function recovery; afterward, we assessed neurogenesis and determined the production of cytokines (IL‐4, IL‐10, and TNF alpha) and neurotrophic factors (BDNF and GAP‐43). During the chronic stage of SCI, rats subjected to INDP showed a significant increase in both motor and sensitive recovery when compared to the control group. Moreover, we found a significant increase in neurogenesis, mainly at the central canal and at both the dorsal and ventral horns of INDP‐treated animals. Finally, INDP induced significant production of antiinflammatory and regeneration‐associated proteins in the chronic stages of SCI.

Conclusions

These findings suggest that INDP has a neurogenic effect that could improve motor and sensitive recovery in the chronic stage of SCI. Moreover, our results also envision the use of INDP as a possible therapeutic strategy for other trauma‐related disorders like traumatic brain injury.

The Impact of Estradiol on Neurogenesis and Cognitive Functions in Alzheimer's Disease

Alzheimer's disease (AD) is described as cognitive and memory impairments with a sex-related epidemiological profile, affecting two times more women than men. There is emerging evidence that alternations in the hippocampal neurogenesis occur at the early stage of AD. Therapies that may effectively slow, stop, or regenerate the dying neurons in AD are being extensively investigated in the last few decades, but none has yet been found to be effective. The regulation of endogenous neurogenesis is one of the main therapeutic targets for AD. Mounting evidence indicates that the neurosteroid estradiol (17β-estradiol) plays a supporting role in neurogenesis, neuronal activity, and synaptic plasticity of AD. This effect may provide preventive and/or therapeutic approaches for AD. In this article, we discuss the molecular mechanism of potential estradiol modulatory action on endogenous neurogenesis, synaptic plasticity, and cognitive function in AD.

Ginsenoside Compound K Induces Adult Hippocampal Proliferation and Survival of Newly Generated Cells in Young and Elderly Mice

Cognitive impairment can be associated with reduced adult hippocampal neurogenesis, and it may contribute to age-associated neurodegenerative diseases such as Alzheimer’s (AD). Compound K (CK) is produced from the protopanaxadiol (PPD)-type ginsenosides Rb1, Rb2, and Rc by intestinal microbial conversion. Although CK has been reported as an inducing effector for neuroprotection and improved cognition in hippocampus, its effect on adult neurogenesis has not been explored yet. Here, we investigated the effect of CK on hippocampal neurogenesis in both young (2 months) and elderly (24 months) mice. CK treatment increased the number of cells co-labeled with 5-ethynyl-2′-deoxyuridine (EdU) and proliferating cell nuclear antigen (PCNA); also, Ki67, specific markers for progenitor cells, was more expressed, thus enhancing the generation of new cells and progenitor cells in the dentate gyrus of both young and elderly mice. Moreover, CK treatment increased the number of cells co-labeled with EdU and NeuN, a specific marker for mature neuron in the dentate gyrus, suggesting that newly generated cells survived and differentiated into mature neurons at both ages. These findings demonstrate that CK increases adult hippocampal neurogenesis, which may be beneficial against neurodegenerative disorders such as AD.

Therapeutic Plasticity of Neural Stem Cells

Neural stem cells (NSCs) have garnered significant scientific and commercial interest in the last 15 years. Given their plasticity, defined as the ability to develop into different phenotypes inside and outside of the nervous system, with a capacity of almost unlimited self-renewal, of releasing trophic and immunomodulatory factors, and of exploiting temporal and spatial dynamics, NSCs have been proposed for (i) neurotoxicity testing; (ii) cellular therapies to treat CNS diseases; (iii) neural tissue engineering and repair; (iv) drug target validation and testing; (v) personalized medicine. Moreover, given the growing interest in developing cell-based therapies to target neurodegenerative diseases, recent progress in developing NSCs from human-induced pluripotent stem cells has produced an analog of endogenous NSCs. Herein, we will review the current understanding on emerging conceptual and technological topics in the neural stem cell field, such as deep characterization of the human compartment, single-cell spatial-temporal dynamics, reprogramming from somatic cells, and NSC manipulation and monitoring. Together, these aspects contribute to further disentangling NSC plasticity to better exploit the potential of those cells, which, in the future, might offer new strategies for brain therapies.

Excitation/inhibition imbalance and impaired neurogenesis in neurodevelopmental and neurodegenerative disorders

The excitation/inhibition (E/I) balance controls the synaptic inputs to prevent the inappropriate responses of neurons to input strength, and is required to restore the initial pattern of network activity. Various neurotransmitters affect synaptic plasticity within neural networks via the modulation of neuronal E/I balance in the developing and adult brain. Less is known about the role of E/I balance in the control of the development of the neural stem and progenitor cells in the course of neurogenesis and gliogenesis. Recent findings suggest that neural stem and progenitor cells appear to be the target for the action of GABA within the neurogenic or oligovascular niches. The same might be true for the role of neuropeptides (i.e. oxytocin) in neurogenic niches. This review covers current understanding of the role of E/I balance in the regulation of neuroplasticity associated with social behavior in normal brain, and in neurodevelopmental and neurodegenerative diseases. Further studies are required to decipher the GABA-mediated regulation of postnatal neurogenesis and synaptic integration of newly-born neurons as a potential target for the treatment of brain diseases.

Astrocytic endothelin-1 overexpression promotes neural progenitor cells proliferation and differentiation into astrocytes via the Jak2/Stat3 pathway after stroke

Background

Endothelin-1 (ET-1) is synthesized and upregulated in astrocytes under stroke. We previously demonstrated that transgenic mice over-expressing astrocytic ET-1 (GET-1) displayed more severe neurological deficits characterized by a larger infarct after transient middle cerebral artery occlusion (tMCAO). ET-1 is a known vasoconstrictor, mitogenic, and a survival factor. However, it is unclear whether the observed severe brain damage in GET-1 mice post stroke is due to ET-1 dysregulation of neurogenesis by altering the stem cell niche.

Methods

Non-transgenic (Ntg) and GET-1 mice were subjected to tMCAO with 1 h occlusion followed by long-term reperfusion (from day 1 to day 28). Neurological function was assessed using a four-point scale method. Infarct area and volume were determined by 2,3,5-triphenyltetra-zolium chloride staining. Neural stem cell (NSC) proliferation and migration in subventricular zone (SVZ) were evaluated by immunofluorescence double labeling of bromodeoxyuridine (BrdU), Ki67 and Sox2, Nestin, and Doublecortin (DCX). NSC differentiation in SVZ was evaluated using the following immunofluorescence double immunostaining: BrdU and neuron-specific nuclear protein (NeuN), BrdU and glial fibrillary acidic protein (GFAP). Phospho-Stat3 (p-Stat3) expression detected by Western-blot and immunofluorescence staining.

Results

GET-1 mice displayed a more severe neurological deficit and larger infarct area after tMCAO injury. There was a significant increase of BrdU-labeled progenitor cell proliferation, which co-expressed with GFAP, at SVZ in the ipsilateral side of the GET-1 brain at 28 days after tMCAO. p-Stat3 expression was increased in both Ntg and GET-1 mice in the ischemia brain at 7 days after tMCAO. p-Stat3 expression was significantly upregulated in the ipsilateral side in the GET-1 brain than that in the Ntg brain at 7 days after tMCAO. Furthermore, GET-1 mice treated with AG490 (a JAK2/Stat3 inhibitor) sh owed a significant reduction in neurological deficit along with reduced infarct area and dwarfed astrocytic differentiation in the ipsilateral brain after tMCAO.

Conclusions

The data indicate that astrocytic endothelin-1 overexpression promotes progenitor stem cell proliferation and astr ocytic differentiation via the Jak2/Stat3 pathway.

[Exercise for depression treatment. Physiological mechanisms]

This literature review considers meta-analyzes, systematic reviews and original research over the last decade addressing a comprehensive analysis of the antidepressant effect of targeted physical exercise and physical activity in general. Exercise is a promising non-pharmacological treatment for depression, showing effects that are comparable or may even exceed other first-line treatments of depression. The article introduces modern ideas about the mechanisms of depression and mechanisms of exercise effects on depression manifestations. The structures of the central nervous system, changing with the effective exercise-based treatment of depression, are indicated. Physical activity stimulates the secretion of growth factors, maintenance of angio-, synapto-, and neurogenesis. The regulation of antioxidant protection of neuronal mitochondria, a decrease in pro-inflammatory reactions and stress reactivity are also observed in response to regular exercise. Physical activity has a multimodal effect that stimulates biochemical pathways and restores neuronal structures disturbed in depression.

Oral administration of the cannabigerol derivative VCE-003.2 promotes subventricular zone neurogenesis and protects against mutant huntingtin-induced neurodegeneration

BACKGROUND

The administration of certain cannabinoids provides neuroprotection in models of neurodegenerative diseases by acting through various cellular and molecular mechanisms. Many cannabinoid actions in the nervous system are mediated by CB1 receptors, which can elicit psychotropic effects, but other targets devoid of psychotropic activity, including CB2 and nuclear PPARγ receptors, can also be the target of specific cannabinoids.

METHODS

We investigated the pro-neurogenic potential of the synthetic cannabigerol derivative, VCE-003.2, in striatal neurodegeneration by using adeno-associated viral expression of mutant huntingtin in vivo and mouse embryonic stem cell differentiation in vitro.

RESULTS

Oral administration of VCE-003.2 protected striatal medium spiny neurons from mutant huntingtin-induced damage, attenuated neuroinflammation and improved motor performance. VCE-003.2 bioavailability was characterized and the potential undesired side effects were evaluated by analyzing hepatotoxicity after chronic treatment. VCE-003.2 promoted subventricular zone progenitor mobilization, increased doublecortin-positive migrating neuroblasts towards the injured area, and enhanced effective neurogenesis. Moreover, we demonstrated the proneurogenic activity of VCE-003.2 in embryonic stem cells. VCE-003.2 was able to increase neuroblast formation and striatal-like CTIP2-mediated neurogenesis.

CONCLUSIONS

The cannabigerol derivative VCE-003.2 improves subventricular zone-derived neurogenesis in response to mutant huntingtin-induced neurodegeneration, and is neuroprotective by oral administration.

Study of transcranial therapy 904 nm in experimental model of stroke

Cerebrovascular accidents (CVAs), commonly known as strokes, can damage the brain through vascular injuries caused by either blood vessel blockages (ischemic stroke) or ruptures (hemorrhagic stroke) which disrupt regular brain blood supply and can cause severe damage to the individual. The objective of the present study was to evaluate the effects of photobiomodulation with a light-emitting diode (LED) device (904 nm, 110 mW, 7 J/cm²) on neurogenesis, muscle resistance, and motor behavior in animals submitted to an experimental model of hemiplegia. The sample consisted of 30 Wistar rats, divided into two groups: control group (GC) and 904-nm LED-treated group (TG). All animals underwent stereotactic surgery for electrode implant and subsequent electrolytic injury to induce an ischemic stroke. TG was subjected to daily LED irradiation (904 nm, 110 mW, 7 J/cm²) for 63 s. Suspension test results indicate an improvement of TG muscle resistance when compared with baseline evaluation (BLT); a reduction in open-field freezing time and the number of fecal bolus pellets suggest diminished anxiety induced by 904-nm LED treatment on treatment days 7 and 21 (TG7 and TG21) compared with the baseline results; and lastly, histological analysis showed important signs of neurogenesis in TG in comparison to CG, especially on treatment days 7 and 21 (TG7 and TG21). In conclusion, the present study suggests that 904-nm LED irradiation may beneficially affect neurogenesis, muscle resistance, and animal motor behavior following ischemic CVA.

Intranasal delivery of M2 macrophage-derived soluble products reduces neuropsychological deficit in patients with cerebrovascular disease: a pilot study

Objective:

We assessed the safety and clinical effectiveness of intranasal therapy with M2 macrophage-derived soluble products (M2-SPs) for treating patients with cerebrovascular disease (CVD).

Materials and methods:

The protocol of the study was registered at www.ClinicalTrails.gov (NCT02957123). The study group comprised 30 patients with chronic CVD. Neurological status was examined before therapy and at 1- and 6-month follow–up. Concentrations of 32 cytokines in the blood serum were evaluated before and 1 month after therapy onset. Neurological assessment was conducted with the following scales: Subjective Assessment of Clinical (neurological) Symptoms (SACS), Hospital Anxiety and Depression Scale (HADS), Functional Mobility Assessment in Eldery Patients (FMA), and Montreal Cognitive Assessment (MoCa).

Results:

M2-SPs treatment (once daily for 28~30 days) was found to be safe and well tolerated. Neuropsychological improvements showed the amelioration of neurological symptoms, reduction in anxiety and depression levels, improvement in balance and gait ability as well as cognitive functions. Clinical effects could be detected at the end of treatment course and was stable during 6-month follow-up. Blood serum cytokine evaluation demonstrated diminished baseline levels of many cytokines including those with neurotrophic activity (brain-derived neurotrophic factor, BDNF; hepatocyte growth factor, HGF; migration inhibitory factor, MIF). Upon treatment, most pronounced clinical responses were observed in patients with most severe cytokine deficiency and post-therapy normalization of MIF and HGF levels.

Conclusion:

Intranasal therapy with M2-SPs is safe and according to preliminary data reduces neuropsychological deficit in patients with chronic CVD. The positive effect of M2-SPs treatment seems to be HGF- and MIF-dependent.

Developmental roles of microglia: A window into mechanisms of disease

Microglia are engineers of the central nervous system (CNS) both in health and disease. In addition to the canonical immunological roles of clearing damaging entities and limiting the spread of toxicity and death, microglia remodel the CNS throughout life. While they have been extensively studied in disease and injury, due to their highly variable functions, their precise role in these contexts still remains uncertain. Over the past decade, we have greatly expanded our understanding of microglial function, including their essential homeostatic roles during development. Here, we review these developmental roles, identify parallels in disease, and speculate whether developmental mechanisms re-emerge in disease and injury. Developmental Dynamics 248:98-117, 2019. © 2018 Wiley Periodicals, Inc.

[Cell therapy for ischemic stroke. Stem cell types and results of pre-clinical trials]

The literature review addresses the use of stem cells (SC) in ischemic stroke (IS). Part 1 of the paper overviews the results of experimental animal studies. Characteristics of different SC types and results of their studies in experimental models of IS are presented in the first section, the second section considers pros and cons of the methods of SC injection.

Carob (Ceratonia siliqua L.) Prevents Short-Term Memory Deficit Induced by Chronic Stress in Rats

Long-term exposure to stressful conditions could impair the normal brain structure and function, specifically the hippocampus-dependent memory. This impairment could be attributed to a decrease in brain-derived neurotrophic factor (BDNF) levels during chronic stress. Knowing that carob [Ceratonia siliqua L. (Fabaceae)] is rich in a wide variety of polyphenols with a high antioxidant value, we hypothesized that the methanolic carob extract (C. siliqua) pods will prevent stress-induced memory impairment. Hence, the methanolic extract of carob pods was investigated for its ability to enhance learning and memory as well as to protect from memory impairment in normal stressed animals. Rats were chronically stressed for 7 weeks via the intruder stress model. Carob extract was administered to animals via intraperitoneal (i.p.) route at a daily dose of 50 mg/kg. Radial arm water maze (RAWM) was utilized to test for spatial learning and memory. In addition, brain tissues were dissected to determine BDNF levels. Chronic stress (CS) impaired short-term spatial memory (number of committed errors: P < 0.05, days to criterion (DTC): P < 0.001). Animal treatment with carob pod extract prevented the short-term memory impairment induced by CS (P < 0.05), while such treatment showed no effect on memory functions of unstressed rats. Moreover, carob pod extract prevented the reduction in the hippocampal BDNF (P < 0.05) induced by chronic stress exposure. In conclusion, CS impaired short-term memory function, while methanolic extract of carob pods prevented this impairment, probably as a result of preventing reduction in BDNF levels in the hippocampus.

Dexmedetomidine Attenuates Neuropathic Pain by Inhibiting P2X7R Expression and ERK Phosphorylation in Rats

α2-Adrenoceptor agonists attenuate hypersensitivity under neuropathic conditions. However, the mechanisms underlying this attenuation remain largely unknown. In the present study, we explored the potential roles of purinergic receptor 7 (P2X7R)/extracellular signal-regulated kinase (ERK) signaling in the anti-nociceptive effect of dexmedetomidine in a rat model of neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve. An animal model of CCI was adopted to mimic the clinical neuropathic pain state. Behavioral hypersensitivity to mechanical and thermal stimuli was determined by von Frey filament and Hargreaves' tests, and the spinal P2X7R expression level and ERK phosphorylation were analyzed using western blot analysis and immunohistochemistry. In parallel with the development of mechanical and thermal hyperalgesia, a significant increase in P2X7R expression was noted in the ipsilateral spinal cord on day 7 after CCI. Intrathecal administration of dexmedetomidine (2.5 µg) for 3 days not only attenuated neuropathic pain but also inhibited the CCI-induced P2X7R upregulation and ERK phosphorylation. Intrathecal dexmedetomidine administration did not produce obvious effects on locomotor function. The present study demonstrated that dexmedetomidine attenuates the neuropathic pain induced by CCI of the sciatic nerve in rats by inhibiting spinal P2X7R expression and ERK phosphorylation, indicating the potential therapeutic implications of dexmedetomidine administration for the treatment of neuropathic pain.