Neurotrophin-4 (ntf4) mediates neurogenesis in mouse embryonic neural stem cells through the inhibition of the signal transducer and activator of transcription-3 (stat3) and the modulation of the activity of protein kinase B

Bioengineered silkworm model for expressing human neurotrophin-4 with potential biomedical application

Neurotrophin-4 (NT-4) is a neurotrophic factor that plays important roles in maintaining nerve cell survival, regulating neuronal differentiation and apoptosis, and promoting nerve injury repair. However, the source of sufficient NT-4 protein and efficient delivery of NT-4 remain a challenge. This study aims to express an activated human NT-4 protein in a large scale by genetically engineering silk gland bioreactor of silkworm as a host. We showed that the expression of human NT-4-functionalized silk material could promote proliferation of mouse HT22 cells when compared to the natural silk protein, and no obvious cytotoxicity was observed under the conditions of different silk materials. Importantly, this functional silk material was able to induce the potential differentiation of HT22 cells, promote peripheral neural cell migration and neurite outgrowth of chicken embryo dorsal root ganglion (DRG). All these results demonstrated a high bioactivity of human NT-4 protein produced in silk gland. Therefore, based on the silkworm model, the further fabrication of different silk materials-carrying active NT-4 protein with good mechanical properties and great biocompatibility will give promising applications in tissue engineering and neurons regeneration.

Transcriptomic insights into adenoid cystic carcinoma via RNA sequencing

Background: The aim of this study was to investigate the underlying mechanisms of adenoid cystic carcinoma (ACC) at the transcriptome level. Materials and methods: We obtained paired tumor and normal salivary gland tissues from 15 ACC patients, which were prepared for RNA sequencing. Results: Gene enrichment analysis revealed that the upregulated pathways were mainly involved in axonogenesis, and the downregulated pathways were mainly related to leukocyte migration, the adaptive immune response, lymphocyte-mediated immunity, and the humoral immune response. T-cells, B-cells and NK cells showed low infiltration in ACC tissues. In addition to the gene fusions MYB-NFIB and MYBL1-NFIB, a new gene fusion, TVP23C-CDRT4, was also detected in 3 ACC tissues. PRAME was significantly upregulated in ACC tissues, while antigen-presenting human leukocyte antigen (HLA) genes were downregulated. Conclusion: We found a new gene fusion, TVP23C-CDRT4, that was highly expressed in ACC. PRAME may be an attractive target for ACC immunotherapy.

The Pathogenesis and Therapeutic Approaches of Diabetic Neuropathy in the Retina

Diabetic retinopathy is a major retinal disease and a leading cause of blindness in the world. Diabetic retinopathy is a neurovascular disease that is associated with disturbances of the interdependent relationship of cells composed of the neurovascular units, i.e., neurons, glial cells, and vascular cells. An impairment of these neurovascular units causes both neuronal and vascular abnormalities in diabetic retinopathy. More specifically, neuronal abnormalities including neuronal cell death and axon degeneration are irreversible changes that are directly related to the vision reduction in diabetic patients. Thus, establishment of neuroprotective and regenerative therapies for diabetic neuropathy in the retina is an emergent task for preventing the blindness of patients with diabetic retinopathy. This review focuses on the pathogenesis of the neuronal abnormalities in diabetic retina including glial abnormalities, neuronal cell death, and axon degeneration. The possible molecular cell death pathways and intrinsic survival and regenerative pathways are also described. In addition, therapeutic approaches for diabetic neuropathy in the retina both in vitro and in vivo are presented. This review should be helpful for providing clues to overcome the barriers for establishing neuroprotection and regeneration of diabetic neuropathy in the retina.

Exploration of the Immune-Related Signatures and Immune Infiltration Analysis in Melanoma

In the present study, we aimed to investigate immune-related signatures and immune infiltration in melanoma. The transcriptome profiling and clinical data of melanoma were downloaded from The Cancer Genome Atlas database, and their matched normal samples were obtained from the Genotype-Tissue Expression database. After merging the genome expression data using Perl, the limma package was used for data normalization. We screened the differentially expressed genes (DEGs) and obtained immune signatures associated with melanoma by an immune-related signature list from the InnateDB database. Univariate Cox regression analysis was used to identify potential prognostic immune genes, and LASSO analysis was used to identify the hub genes. Next, based on the results of multivariate Cox regression analysis, we constructed a risk model for melanoma. We investigated the correlation between risk score and clinical characteristics and overall survival (OS) of patients. Based on the TIMER database, the association between selected immune signatures and immune cell distribution was evaluated. Next, the Wilcoxon rank-sum test was performed using CIBERSORT, which confirmed the differential distribution of immune-infiltrating cells between different risk groups. We obtained a list of 91 differentially expressed immune-related signatures. Functional enrichment analysis indicated that these immune-related DEGs participated in several areas of immune-related crosstalk, including cytokine-cytokine receptor interactions, JAK-STAT signaling pathway, chemokine signaling pathway, and Th17 cell differentiation pathway. A risk model was established based on multivariate Cox analysis results, and Kaplan-Meier analysis was performed. The Kruskal-Wallis test suggested that a high risk score indicated a poorer OS and correlated with higher American Joint Committee on Cancer-TNM (AJCC-TNM) stages and advanced pathological stages (P < 0.01). Furthermore, the association between hub immune signatures and immune cell distribution was evaluated in specific tumor samples. The Wilcoxon rank-sum test was used to estimate immune infiltration density in the two groups, and results showed that the high-risk group exhibited a lower infiltration density, and the dominant immune cells included M0 macrophages (P = 0.023) and activated mast cells (P = 0.005).

Upregulated NTF4 in colorectal cancer promotes tumor development via regulating autophagy

Autophagy plays a key role in colorectal cancer (CRC) development and reduces the sensitivity of CRC cells to treatment. The present study reported a novel tumor‑suppressive role for autophagy, which was demonstrated to be regulated through the novel oncogene neurotrophin‑4 (NTF4). NTF4 was significantly overexpressed in tumor tissue compared with non‑tumor mucosa, and the upregulation of NTF4 in CRC was associated with poor overall survival and advanced TNM stage. The genetic knockdown of NTF4 using short hairpin RNA in CRC cells prevented epithelial‑to‑mesenchymal transition and activated autophagy; this was regulated through the interaction between autophagy‑associated gene 5 (Atg5) and the mitogen‑activated protein kinase pathway. In addition, the knockdown of NTF4 inhibited cell invasion, migration, proliferation and colony formation, and promoted cell cycle arrest. Treatment of the cells with the autophagy inhibitor chloroquine (CQ) rescued these functions and promoted cell invasion, migration, proliferation and colony formation. Finally, the knockdown of NTF4 inhibited the growth of subcutaneous xenografts in Balb/c‑nu mice. In conclusion, these findings suggested that NTF4 may be a diagnostic marker associated with the overall survival and progression of patients with CRC. NTF4 was found to promote tumorigenesis and CRC development through autophagy regulation.

Ergothioneine-induced neuronal differentiation is mediated through activation of S6K1 and neurotrophin 4/5-TrkB signaling in murine neural stem cells

The promotion of neurogenesis is considered to be an effective therapeutic strategy for neuropsychiatric disorders because impairment of neurogenesis is associated with the onset and progression of these disorders. We have previously demonstrated that orally ingested ergothioneine (ERGO), a naturally occurring antioxidant and hydrophilic amino acid, promotes neurogenesis in the hippocampal dentate gyrus (DG) with its abundant neural stem cells (NSCs) and exerts antidepressant-like effects in mice. Independent of its antioxidant activities, ERGO induces in cultured NSCs this differentiation through induction of the basic helix-loop-helix transcription factor Math1. However, the upstream signaling of Math1 in the mechanisms underlying ERGO-induced neuronal differentiation remains unclear. The purpose of the present study was to elucidate the upstream signaling with the aim of discovering novel targets for the treatment of neuropsychiatric disorders. We focused on neurotrophic factor signaling, as it is important for the promotion of neurogenesis and the induction of antidepressant effects. We also focused on the signaling of the mammalian target of rapamycin (mTOR) complex 1 (mTORC1), a known amino acid sensor, and the members of this signaling pathway, mTOR and p70 ribosomal protein S6 kinase 1 (S6K1). Exposure of cultured NSCs to ERGO significantly increased the expression of phosphorylated S6K1 (p-S6K1) at Thr389 in only 1 h, of phosphorylated mTOR (p-mTOR) in 6 h, and of the gene product of neurotrophin 4/5 (NT5) which activates tropomyosin receptor kinase B (TrkB) in 24 h. ERGO increased the population of βIII-tubulin-positive neurons, and this effect was suppressed by the inhibitors of S6K1 (PF4708671), mTORC1 (rapamycin), and TrkB (GNF5837). Oral administration of ERGO to mice significantly increased in the DG the expression of p-S6K1 at Thr389, the gene product of NT5, and phosphorylated TrkB but not that of p-mTOR. Thus, neuronal differentiation of NSCs induced by ERGO is mediated, at least in part, through phosphorylation of S6K1 at Thr389 and subsequent activation of TrkB signaling through the induction of NT5. Thus, S6K1 and NT5 might be promising target molecules for the treatment of neuropsychiatric disorders.

Serum-mediated Activation of Bone Marrow-derived Mesenchymal Stem Cells in Ischemic Stroke Patients: A Novel Preconditioning Method

Stroke induces complex and dynamic, local and systemic changes including inflammatory reactions, immune responses, and repair and recovery processes. Mesenchymal stem cells (MSCs) have been shown to enhance neurological recovery after stroke. We hypothesized that serum factors play a critical role in the activation of bone marrow (BM) MSCs after stroke such as by increasing proliferation, paracrine effects, and rejuvenation. Human MSCs (hMSCs) were grown in fetal bovine serum (FBS), normal healthy control serum (NS), or stroke patient serum (SS). MSCs cultured in growth medium with 10% SS or NS exhibited higher proliferation indices than those cultured with FBS (P < 0.01). FBS-, NS-, and SS-hMSCs showed differences in the expression of trophic factors; vascular endothelial growth factor, glial cell–derived neurotrophic factor, and fibroblast growth factor were densely expressed in samples cultured with SS (P < 0.01). In addition, SS-MSCs revealed different cell cycle– or aging-associated messenger RNA expression in a later passage, and β-galactosidase staining showed the senescence of MSCs observed during culture expansion was lower in MSCs cultured with SS than those cultured with NS or FBS (P < 0.01). Several proteins related to the activity of receptors, growth factors, and cytokines were more prevalent in the serum of stroke patients than in that of normal subjects. Neurogenesis and angiogenesis were markedly increased in rats that had received SS-MSCs (P < 0.05), and these rats showed significant behavioral improvements (P < 0.01). Our results indicate that stroke induces a process of recovery via the activation of MSCs. Culture methods for MSCs using SS obtained during the acute phase of a stroke could constitute a novel MSC activation method that is feasible and efficient for the neurorestoration of stroke.

What do the genetic association data say about the high risk of suicide in people with depression? A novel network-based approach to find common molecular basis for depression and suicidal behavior and related therapeutic targets

BACKGROUND

Available sources indicate that the risk of suicide in people with major depression is higher than other psychiatric disorders. Although it seems that these two conditions may have a shared cause in some cases, no studies have been conducted to identify a common basis for them.

METHODS

In this study, following an extensive review of literature, we found almost all the genes that are involved in major depression and suicidal behavior, and we isolated genes shared between the two conditions. Then, we found all physical or functional interactions within three mentioned gene sets and reconstructed three genetic interactive networks. All networks were analyzed topologically and enriched functionally. Finally, using a drug repurposing approach, we found the main available drugs that interacted with the most central genes shared between suicidal behavior and depression.

RESULTS

The results demonstrated that BDNF, SLC6A4, CREB1, and TNF are the most fundamental shared genes; and generally, disordered dopaminergic, serotonergic, and immunologic pathways in neuronal projections are the main shared deficient pathways. In addition, we found two genes, SLC6A4 and SLC6A2, to be the main therapeutic targets, and Serotonin-Norepinephrine Reuptake Inhibitors (SNRI) and Tricyclic Antidepressants (TCA) to be the most effective drugs for individuals with depression at risk for suicide.

CONCLUSIONS

Our results, in addition to shedding light on the integrated molecular basis of depression-suicide, offer new therapeutic targets for individuals with depression at high risk for suicide and could pave the way for future preclinical and clinical studies. However, integrative systems biology-based studies highly depend on existing data and related databases, as well as the arrival of new experimental data sources in the future, possibly affecting the current results.

Neurotrophin Signaling and Stem Cells-Implications for Neurodegenerative Diseases and Stem Cell Therapy

Neurotrophins (NTs) are members of a neuronal growth factor protein family whose action is mediated by the tropomyosin receptor kinase (TRK) receptor family receptors and the p75 NT receptor (p75NTR), a member of the tumor necrosis factor (TNF) receptor family. Although NTs were first discovered in neurons, recent studies have suggested that NTs and their receptors are expressed in various types of stem cells mediating pivotal signaling events in stem cell biology. The concept of stem cell therapy has already attracted much attention as a potential strategy for the treatment of neurodegenerative diseases (NDs). Strikingly, NTs, proNTs, and their receptors are gaining interest as key regulators of stem cells differentiation, survival, self-renewal, plasticity, and migration. In this review, we elaborate the recent progress in understanding of NTs and their action on various stem cells. First, we provide current knowledge of NTs, proNTs, and their receptor isoforms and signaling pathways. Subsequently, we describe recent advances in the understanding of NT activities in various stem cells and their role in NDs, particularly Alzheimer's disease (AD) and Parkinson's disease (PD). Finally, we compile the implications of NTs and stem cells from a clinical perspective and discuss the challenges with regard to transplantation therapy for treatment of AD and PD.

Genome-wide patterns of copy number variation in the Chinese yak genome

Background

Copy number variation (CNV) represents an important source of genetic divergence that can produce drastic phenotypic differences and may therefore be subject to selection during domestication and environmental adaptation. To investigate the evolutionary dynamics of CNV in the yak genome, we used a read depth approach to detect CNV based on genome resequencing data from 14 wild and 65 domestic yaks and determined CNV regions related to domestication and adaptations to high-altitude.

Results

We identified 2,634 CNV regions (CNVRs) comprising a total of 153 megabases (5.7 % of the yak genome) and 3,879 overlapping annotated genes. Comparison between domestic and wild yak populations identified 121 potentially selected CNVRs, harboring genes related to neuronal development, reproduction, nutrition and energy metabolism. In addition, we found 85 CNVRs that are significantly different between domestic yak living in high- and low-altitude areas, including three genes related to hypoxia response and six related to immune defense. This analysis shows that genic CNVs may play an important role in phenotypic changes during yak domestication and adaptation to life at high-altitude.

Conclusions

We present the first refined CNV map for yak along with comprehensive genomic analysis of yak CNV. Our results provide new insights into the genetic basis of yak domestication and adaptation to living in a high-altitude environment, as well as a valuable genetic resource that will facilitate future CNV association studies of important traits in yak and other bovid species.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2702-6) contains supplementary material, which is available to authorized users.

Role of Periostin in Adhesion and Migration of Bone Remodeling Cells

Periostin is an extracellular matrix protein highly expressed in collagen-rich tissues subjected to continuous mechanical stress. Functionally, periostin is involved in tissue remodeling and its altered function is associated to numerous pathological processes. In orthodontics, periostin plays key roles in the maintenance of dental tissues and it is mainly expressed in those areas where tension or pressing forces are taking place. In this regard, high expression of periostin is essential to promote migration and proliferation of periodontal ligament fibroblasts. However little is known about the participation of periostin in migration and adhesion processes of bone remodeling cells. In this work we employ the mouse pre-osteoblastic MC3T3-E1 and the macrophage-like RAW 264.7 cell lines to overexpress periostin and perform different cell-based assays to study changes in cell behavior. Our data indicate that periostin overexpression not only increases adhesion capacity of MC3T3-E1 cells to different matrix proteins but also hampers their migratory capacity. Changes on RNA expression profile of MC3T3-E1 cells upon periostin overexpression have been also analyzed, highlighting the alteration of genes implicated in processes such as cell migration, adhesion or bone metabolism but not in bone differentiation. Overall, our work provides new evidence on the impact of periostin in osteoblasts physiology.

Neurotrophic Factors and Their Potential Applications in Tissue Regeneration

Neurotrophic factors are growth factors that can nourish neurons and promote neuron survival and regeneration. They have been studied as potential drug candidates for treating neurodegenerative diseases. Since their identification, there are more and more evidences to indicate that neurotrophic factors are also expressed in non-neuronal tissues and regulate the survival, anti-inflammation, proliferation and differentiation in these tissues. This mini review summarizes the characteristics of the neurotrophic factors and their potential clinical applications in the regeneration of neuronal and non-neuronal tissues.

Genetics studies indicate that neural induction and early neuronal maturation are disturbed in autism

Postmortem neuropathological studies of autism consistently reveal distinctive types of malformations, including cortical dysplasias, heterotopias, and various neuronomorphometric abnormalities. In keeping with these observations, we review here that 88% of high-risk genes for autism influence neural induction and early maturation of the neuroblast. In addition, 80% of these same genes influence later stages of differentiation, including neurite and synapse development, suggesting that these gene products exhibit long-lasting developmental effects on cell development as well as elements of redundancy in processes of neural proliferation, growth, and maturation. We also address the putative genetic overlap of autism with conditions like epilepsy and schizophrenia, with implications to shared and divergent etiologies. This review imports the necessity of a frameshift in our understanding of the neurodevelopmental basis of autism to include all stages of neuronal maturation, ranging from neural induction to synaptogenesis.

Interaction of Notch and gp130 signaling in the maintenance of neural stem and progenitor cells

Notch and gp130 signaling are involved in the regulation of multiple cellular processes across various tissues during animal ontogenesis. In the developing nervous system, both signaling pathways intervene at many stages to determine cell fate-from the first neural lineage commitment and generation of neuronal precursors, to the terminal specification of cells as neurons and glia. In most cases, the effects of Notch and gp130 signaling in these processes are similar. The aim of the current review was to summarize the knowledge regarding the roles of Notch and gp130 signaling in the maintenance of neural stem and progenitor cells during animal ontogenesis, from early embryo to adult. Recent data show a direct crosstalk between these signaling pathways that seems to be specific for a particular type of neural progenitors.

Brain site-specific proteome changes in aging-related dementia

This study is aimed at gaining insights into the brain site-specific proteomic senescence signature while comparing physiologically aged brains with aging-related dementia brains (for example, Alzheimer's disease (AD)). Our study of proteomic differences within the hippocampus (Hp), parietal cortex (pCx) and cerebellum (Cb) could provide conceptual insights into the molecular mechanisms involved in aging-related neurodegeneration. Using an isobaric tag for relative and absolute quantitation (iTRAQ)-based two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D-LC-MS/MS) brain site-specific proteomic strategy, we identified 950 proteins in the Hp, pCx and Cb of AD brains. Of these proteins, 31 were significantly altered. Most of the differentially regulated proteins are involved in molecular transport, nervous system development, synaptic plasticity and apoptosis. Particularly, proteins such as Gelsolin (GSN), Tenascin-R (TNR) and AHNAK could potentially act as novel biomarkers of aging-related neurodegeneration. Importantly, our Ingenuity Pathway Analysis (IPA)-based network analysis further revealed ubiquitin C (UBC) as a pivotal protein to interact with diverse AD-associated pathophysiological molecular factors and suggests the reduced ubiquitin proteasome degradation system (UPS) as one of the causative factors of AD.

Astrocytic phosphorylation of PDK1 on Tyr9 following an excitotoxic lesion in the mouse hippocampus

3-phosphoinositide-dependent kinase-1 (PDK1) is suggested to play important roles in the regulation of synaptic plasticity and neuronal cell survival in the mature CNS. Although few studies have investigated the roles of PDK1, little is known about PDK1 changes in glial cells under neuropathological conditions. In current report, phosphorylation of PDK1 was monitored specially on tyrosine residues, following the induction of an excitotoxic lesion in rat brain by using kainic acid administration. In injured hippocampal CA3 region, Tyr9 phosphorylation of PDK1 was increased from 4h until 3 day post-injection. Double immunohistochemistry further evaluated that these phosphorylated forms of PDK1 were localized in astrocytes not other cells. Overexpression of unphosphorylatable mutant, PDK1-Y9F leads to inhibit Protein kinase B (PKB/Akt) activation and cAMP responsive element binding protein (CREB) phosphorylation. In conclusion, our results suggested for the first time that tyrosine phosphorylation of PDK1 is required for PKB and CREB activation in KA-mediated excitotoxic lesion in mouse brain.

Tianma modulates blood vessel tonicity

Tianma is a traditional Chinese medicine (TCM) often used for the treatment of hypertension and heart diseases. To elucidate the function of tianma at the molecular level, we investigated the effect of tianma on vascular functions and aortic protein metabolism. We found that long-term treatment with tianma (~2.5g/kg/day for three months) in one-year-old rats could enhance acetylcholine (ACh)-induced vasorelaxation in endothelium-intact thoracic aortic rings against both KCl (80 mM)- and phenylephrine (PE)-induced contraction. By using the iTRAQ (isobaric tag for relative and absolute quantification) technique, we confirmed from the functional data at the proteome level that tianma treatment down-regulated the expressions of contractile proteins (e.g. Acta2) and other related structural proteins (e.g. desmin), and up-regulated the expressions of extracellular matrix (ECM) glycoproteins (e.g. Fbln5) and anti-thrombotic proteins (e.g. Anxa2) in aortic tissue. By inductive reasoning, tianma could perform its vasodilatory effect not only by inhibiting vascular smooth muscle contraction, but also by enhancing blood vessel elasticity and stabilizing the arterial structure. Thus, tianma might become a novel therapeutic herbal medicine for cardiovascular diseases by regulating the aortic proteome metabolism.

P60TRP interferes with the GPCR/secretase pathway to mediate neuronal survival and synaptogenesis

In the present study, we show that overexpression of the G-protein-coupled receptor (GPCR)-associated sorting protein p60TRP (transcription regulator protein) in neural stem cells (NSCs) and in a transgenic mouse model modulates the phosphorylation and proteolytic processing of amyloid precursor protein (App), N-cadherin (Cdh2), presenilin (Psen) and τ protein (Mapt). Our results suggest that p60TRP is an inhibitor of Bace1 (β-site App cleaving enzyme) and Psen. We performed several apoptosis assays [Annexin-V, TdT-mediated dUTP Nick-End Labeling (TUNEL), caspase-3/7] using NSCs and PC12 cells (overexpressing p60TRP and knockdown of p60TRP) to substantiate the neuroprotective role of p60TRP. Functional analyses, both in vitro and in vivo, revealed that p60TRP promotes neurosynaptogenesis. Characterization of the cognitive function of p60TRP transgenic mice using the radial arm water maze test demonstrated that p60TRP improved memory and learning abilities. The improved cognitive functions could be attributed to increased synaptic connections and plasticity, which was confirmed by the modulation of the γ-aminobutyric acid receptor system and the elevated expression of microtubule-associated protein 2, synaptophysin and Slc17a7 (vesicle glutamate transporter, Vglut1), as well as by the inhibition of Cdh2 cleavage. In conclusion, interference with the p60TRP/ GPCR/secretase signalling pathway might be a new therapeutic target for the treatment of Alzheimer's disease (AD).

Tianma modulates proteins with various neuro-regenerative modalities in differentiated human neuronal SH-SY5Y cells

Tianma (Rhizoma gastrodiae) is the dried rhizome of the plant Gastrodia elata Blume (Orchidaceae family). As a medicinal herb in traditional Chinese medicine (TCM) its functions are to control convulsions, pain, headache, dizziness, vertigo, seizure, epilepsy and others. In addition, tianma is frequently used for the treatment of neurodegenerative disorders though the mechanism of action is widely unknown. Accordingly, this study was designed to examine the effects of tianma on the proteome metabolism in differentiated human neuronal SH-SY5Y cells to explore its specific effects on neuronal signaling pathways. Using an iTRAQ (isobaric tags for relative and absolute quantitation)-based proteomics research approach, we identified 2390 modulated proteins, out of which 406 were found to be altered by tianma in differentiated human neuronal SH-SY5Y cells. Based on the observed data, we hypothesize that tianma promotes neuro-regenerative signaling cascades by controlling chaperone/proteasomal degradation pathways (e.g. CALR, FKBP3/4, HSP70/90) and mobilizing neuro-protective genes (such as AIP5) as well as modulating other proteins (RTN1/4, NCAM, PACSIN2, and PDLIM1/5) with various regenerative modalities and capacities related to neuro-synaptic plasticity.

The novel protein MANI modulates neurogenesis and neurite-cone growth

Neuronal regeneration and axonal re-growth in the injured mammalian central nervous system remains an unsolved field. To date, three myelin-associated proteins [Nogo or reticulon 4 (RTN4), myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMG)] are known to inhibit axonal regeneration via activation of the neuronal glycosylphosphatidylinositol-anchored Nogo receptor [NgR, together with p75 neurotrophin receptor (p75NTR) and Lingo-1]. In the present study we describe the novel protein MANI (myelin-associated neurite-outgrowth inhibitor) that localizes to neural membranes. Functional characterization of MANI overexpressing neural stem cells (NSCs) revealed that the protein promotes differentiation into catecholaminergic neurons. Yeast two-hybrid screening and co-immunoprecipitation experiments confirmed the cell division cycle protein 27 (Cdc27) as an interacting partner of Mani. The analyses of Mani-overexpressing PC12 cells demonstrated that Mani retards neuronal axonal growth as a positive effector of Cdc27 expression and activity. We show that knockdown of Cdc27, a component of the anaphase-promoting complex (APC), leads to enhanced neurite outgrowth. Our finding describes the novel MANI-Cdc27-APC pathway as an important cascade that prevents neurons from extending axons, thus providing implications for the potential treatment of neurodegenerative diseases.

Neuronal p60TRP expression modulates cardiac capacity

Heart failure, including myocardial infarction, is the leading cause for death and the incidence of cardiovascular diseases is predicted to continue to rise worldwide. In the present study we investigated the whole heart proteome profile of transgenic p60-Transcription Regulator Protein (p60TRP) mice to gain an insight into the molecular events caused by the long-term effect of neural p60TRP over-expression on cardiac proteome changes and its potential implication for cardiovascular functions. Using an iTRAQ (isobaric tags for relative and absolute quantitation)-based proteomics research approach, we identified 1148 proteins, out of which 116 were found to be significantly altered in the heart of neural transgenic p60TRP mice. Based on the observed data, we conclude that in vivo neural over-expression of transgenic p60TRP with its neuroprotective therapeutic potential significantly affects cardiovascular capacities.

miRNAs stem cell reprogramming for neuronal induction and differentiation

Mimicking the natural brain environment during neurogenesis represents the main challenge for efficient in vitro neuronal differentiation of stem cells. The discovery of miRNAs opens new possibilities in terms of modulation of stem cells lineage commitment and differentiation. Many studies demonstrated that in vitro transient overexpression or inhibition of brain-specific miRNAs in stem cells significantly directed differentiation along neuronal cell lineages. Modulating miRNA expression offers new pathways for post-transcriptional gene regulation and stem cell commitment. Neurotrophins and neuropoietins signaling pathways are the main field of investigation for neuronal commitment, differentiation, and maturation. This review will highlight examples of crosstalk between stem-cell-specific and brain-specific signaling pathways and key miRNA candidates for neuronal commitment. Recent progress on understanding miRNAs genetic networks offers promising prospects for their increasing application in the development of new cellular therapies in humans.

Energy metabolism in adult neural stem cell fate

The adult mammalian brain contains a population of neural stem cells that can give rise to neurons, astrocytes, and oligodendrocytes and are thought to be involved in certain forms of memory, behavior, and brain injury repair. Neural stem cell properties, such as self-renewal and multipotency, are modulated by both cell-intrinsic and cell-extrinsic factors. Emerging evidence suggests that energy metabolism is an important regulator of neural stem cell function. Molecules and signaling pathways that sense and influence energy metabolism, including insulin/insulin-like growth factor I (IGF-1)-FoxO and insulin/IGF-1-mTOR signaling, AMP-activated protein kinase (AMPK), SIRT1, and hypoxia-inducible factors, are now implicated in neural stem cell biology. Furthermore, these signaling modules are likely to cooperate with other pathways involved in stem cell maintenance and differentiation. This review summarizes the current understanding of how cellular and systemic energy metabolism regulate neural stem cell fate. The known consequences of dietary restriction, exercise, aging, and pathologies with deregulated energy metabolism for neural stem cells and their differentiated progeny will also be discussed. A better understanding of how neural stem cells are influenced by changes in energy availability will help unravel the complex nature of neural stem cell biology in both the normal and diseased state.