Hippocalcin Promotes Neuronal Differentiation and Inhibits Astrocytic Differentiation in Neural Stem Cells

Epigallocatechin gallate improves neuronal damage in animal model of ischemic stroke and glutamate-exposed neurons via modulation of hippocalcin expression

Epigallocatechin gallate (EGCG) is a polyphenolic component of green tea that has anti-oxidative and anti-inflammatory effects in neurons. Ischemic stroke is a major neurological disease that causes irreversible brain disorders. It increases the intracellular calcium concentration and induces apoptosis. The regulation of intracellular calcium concentration is important to maintain the function of the nervous system. Hippocalcin is a neuronal calcium sensor protein that controls intracellular calcium concentration. We investigated whether EGCG treatment regulates the expression of hippocalcin in stroke animal model and glutamate-induced neuronal damage. We performed middle cerebral artery occlusion (MCAO) to induce cerebral ischemia. EGCG (50 mg/kg) or phosphate buffered saline was injected into the abdominal cavity just before MCAO surgery. The neurobehavioral tests were performed 24 h after MCAO surgery and cerebral cortex tissue was collected. MCAO damage induced severe neurobehavioral disorders, increased infarct volume, and decreased the expression of hippocalcin in the cerebral cortex. However, EGCG treatment improved these deficits and alleviated the decrease in hippocalcin expression in cerebral cortex. In addition, EGCG dose-dependently alleviated neuronal cell death and intracellular calcium overload in glutamate-exposed neurons. Glutamate exposure reduced hippocalcin expression, decreased Bcl-2 expression, and increased Bax expression. However, EGCG treatment mitigated these changes caused by glutamate toxicity. EGCG also attenuated the increase in caspase-3 and cleaved caspase-3 expressions caused by glutamate exposure. The effect of EGCG was more pronounced in non-transfected cells than in hippocalcin siRNA-transfected cells. These findings demonstrate that EGCG protects neurons against glutamate toxicity through the regulation of Bcl-2 family proteins and caspase-3. It is known that hippocalcin exerts anti-apoptotic effect through the modulation of apoptotic pathway. Thus, we can suggest evidence that EGCG has a neuroprotective effect by regulating hippocalcin expression in ischemic brain damage and glutamate-exposed cells.

Mesenchymal Stem Cell-Extracellular Vesicle Therapy for Stroke: Scalable Production and Imaging Biomarker Studies

A major clinical hurdle to translate MSC-derived extracellular vesicles (EVs) is the lack of a method to scale-up the production of EVs with customized therapeutic properties. In this study, we tested whether EV production by a scalable 3D-bioprocessing method is feasible and improves neuroplasticity in animal models of stroke using MRI study. MSCs were cultured in a 3D-spheroid using a micro-patterned well. The EVs were isolated with filter and tangential flow filtration and characterized using electron microscopy, nanoparticle tracking analysis, and small RNA sequencing. Compared to conventional 2D culture, the production-reproduction of EVs (the number/size of particles and EV purity) obtained from 3D platform were more consistent among different lots from the same donor and among different donors. Several microRNAs with molecular functions associated with neurogenesis were upregulated in EVs obtained from 3D platform. EVs induced both neurogenesis and neuritogenesis via microRNAs (especially, miR-27a-3p and miR-132-3p)-mediated actions. EV therapy improved functional recovery on behavioral tests and reduced infarct volume on MRI in stroke models. The dose of MSC-EVs of 1/30 cell dose had similar therapeutic effects. In addition, the EV group had better anatomical and functional connectivity on diffusion tensor imaging and resting-state functional MRI in a mouse stroke model. This study shows that clinical-scale MSC-EV therapeutics are feasible, cost-effective, and improve functional recovery following experimental stroke, with a likely contribution from enhanced neurogenesis and neuroplasticity.

Phospholipase D1 promotes astrocytic differentiation through the FAK/AURKA/STAT3 signaling pathway in hippocampal neural stem/progenitor cells

Phospholipase D1 (PLD1) plays a crucial role in cell differentiation of different cell types. However, the involvement of PLD1 in astrocytic differentiation remains uncertain. In the present study, we investigate the possible role of PLD1 and its product phosphatidic acid (PA) in astrocytic differentiation of hippocampal neural stem/progenitor cells (NSPCs) from hippocampi of embryonic day 16.5 rat embryos. We showed that overexpression of PLD1 increased the expression level of glial fibrillary acidic protein (GFAP), an astrocyte marker, and the number of GFAP-positive cells. Knockdown of PLD1 by transfection with Pld1 shRNA inhibited astrocytic differentiation. Moreover, PLD1 deletion (Pld1^-/-) suppressed the level of GFAP in the mouse hippocampus. These results indicate that PLD1 plays a crucial role in regulating astrocytic differentiation in hippocampal NSPCs. Interestingly, PA itself was sufficient to promote astrocytic differentiation. PA-induced GFAP expression was decreased by inhibition of signal transducer and activation of transcription 3 (STAT3) using siRNA. Furthermore, PA-induced STAT3 activation and astrocytic differentiation were regulated by the focal adhesion kinase (FAK)/aurora kinase A (AURKA) pathway. Taken together, our findings suggest that PLD1 is an important modulator of astrocytic differentiation in hippocampal NSPCs via the FAK/AURKA/STAT3 signaling pathway.

Brain Homogenate of a Rat Model of Alzheimer's Disease Modifies the Secretome of 3D Cultured Periodontal Ligament Stem Cells: A Potential Neuroregenerative Therapy

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disease leading to neuronal cell death and manifested by cognitive disorders and behavioral impairment. Mesenchymal stem cells (MSCs) are one of the most promising candidates to stimulate neuroregeneration and prevent disease progression. Optimization of MSC culturing protocols is a key strategy to increase the therapeutic potential of the secretome.

Objectives

Here, we investigated the effect of brain homogenate of a rat model of AD (BH-AD) on the enhancement of protein secretion in the secretome of periodontal ligament stem cells (PDLSCs) when cultured in a 3D environment. Moreover, the effect of this modified secretome was examined on neural cells to study the impact of the conditioned medium (CM) on stimulation of regeneration or immunomodulation in AD.

Methods

PDLSCs were isolated and characterized. Then, the spheroids of PDLSCs were generated in a modified 3D culture plate. PDLSCs-derived CM was prepared in the presence of BH-AD (PDLSCs-HCM) and the absence of it (PDLSCs-CM). The viability of C6 glioma cells was assessed after exposure to different concentrations of both CMs. Then, a proteomic analysis was performed on the CMs.

Results

Differentiation into adipocytes and high expression of MSCs markers verified the precise isolation of PDLSCs. The PDLSC spheroids were formed after 7 days of 3D culturing, and their viability was confirmed. The effect of CMs on C6 glioma cell viability showed that both CMs at low concentrations (> 20 mg/mL) had no cytotoxic effect on C6 neural cells. The results showed that PDLSCs-HCM contains higher concentrations of proteins compared to PDLSCs-CM, including Src-homology 2 domain (SH2)-containing PTPs (SHP-1) and muscle glycogen phosphorylase (PYGM) proteins. SHP-1 has a role in nerve regeneration, and PYGM is involved in glycogen metabolism.

Conclusions

The modified secretome derived from 3D cultured spheroids of PDLSCs treated by BH-AD as a reservoir of regenerating neural factors can serve as a potential source for AD treatment.

Kinase inhibit region of SOCS3 attenuates IL6-induced proliferation and astrocytic differentiation of neural stem cells via cross talk between signaling pathways

AIMS

Efficiency of neural stem cells (NSCs) therapy for brain injury is restricted by astrogliosis around the damaged region, in which JAK2/STAT3 signaling plays a key role. The SOCS3 that can directly inhibit JAK/STAT3 pathway. Here, we investigated the effects of a fusion peptide that combined kinase inhibitory region (KIR) of SOCS3 and virus trans-activator of transcription (TAT) on biological behavior of cultured NSCs under inflammatory conditions.

METHODS

NSCs were isolated from embryonic brain of SD rats, TAT-KIR was synthesized, and penetration rate was evaluated by flow cytometry (FACS). CCK8, immunostaining, and FACS were used to detected of TAT-KIR on the proliferation of NSCs. The expressions of GFAP and β tubulin III positive cells induced by IL6 with/without TAT-KIR were examined by immunostaining and Western blotting to observe the NSCs differentiation, and the effect of TAT-KIR on signaling cross talk was observed by Western blotting.

RESULTS

Penetration rate of TAT-KIR into primary cultured NSCs was up to 94%. TAT-KIR did not affect the growth and viability of NSCs. It significantly reduced the NSCs proliferation that enhanced by IL-6 stimulation via blocking the cell cycle progression from the G0/G1 to S phase. In addition, TAT-KIR attenuated astrocytic differentiation and kept high level of neuronal differentiation derived from IL-6-induced NSCs. The fate of NSCs differentiation under inflammatory conditions was affected by TAT-KIR, which was associated with synchronous inhibition of STAT3 and AKT, while promoting JNK expression.

CONCLUSION

TAT-KIR mimetic of SOCS3 could be a promising approach for brain repair via regulating the biological behaviors of exogenous NSCs.

Neuroprotective Effect of Bcl-2 on Lipopolysaccharide-Induced Neuroinflammation in Cortical Neural Stem Cells

Neuroinflammation is involved in the pathogenesis of neurodegenerative diseases due to increased levels of pro-inflammatory cytokines in the central nervous system (CNS). Chronic neuroinflammation induced by neurotoxic molecules accelerates neuronal damage. B-cell lymphoma 2 (Bcl-2) is generally accepted to be an important anti-apoptotic factor. However, the role of Bcl-2 in neuroprotection against neuroinflammation remains to be determined. The purpose of this study was to investigate the neuroprotective effect of Bcl-2 on lipopolysaccharide (LPS)-induced neuroinflammation in cortical neural stem cells (NSCs). LPS decreased mRNA and protein levels of Tuj-1, a neuron marker, and also suppressed neurite outgrowth, indicating that LPS results in inhibition of neuronal differentiation of NSCs. Furthermore, LPS treatment inhibited Bcl-2 expression during neuronal differentiation; inhibition of neuronal differentiation by LPS was rescued by Bcl-2 overexpression. LPS-induced pro-inflammatory cytokines, including interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α), were decreased by Bcl-2 overexpression. Conversely, Bcl-2 siRNA increased the LPS-induced levels of IL-6 and TNF-α, and decreased neuronal differentiation of NSCs, raising the possibility that Bcl-2 mediates neuronal differentiation by inhibiting the LPS-induced inflammatory response in NSC. These results suggest that Bcl-2 has a neuroprotective effect by inhibiting the LPS-induced inflammatory response in NSCs.

Restoring Oat Nanoparticles Mediated Brain Memory Function of Mice Fed Alcohol by Sorting Inflammatory Dectin-1 Complex Into Microglial Exosomes

Microglia modulate pro-inflammatory and neurotoxic activities. Edible plant-derived factors improve brain function. Current knowledge of the molecular interactions between edible plant-derived factors and the microglial cell is limited. Here an alcohol-induced chronic brain inflammation model is used to identify that the microglial cell is the novel target of oat nanoparticles (oatN). Oral administration of oatN inhibits brain inflammation and improves brain memory function of mice that are fed alcohol. Mechanistically, ethanol activates dectin-1 mediated inflammatory pathway. OatN is taken up by microglial cells via β-glucan mediated binding to microglial hippocalcin (HPCA) whereas oatN digalactosyldiacylglycerol (DGDG) prevents assess of oatN β-glucan to dectin-1. Subsequently endocytosed β-glucan/HPCA is recruited in an endosomal recycling compartment (ERC) via interaction with Rab11a. This complex then sequesters the dectin-1 in the ERC in an oatN β-glucan dependent manner and alters the location of dectin-1 from Golgi to early endosomes and lysosomes and increases exportation of dectin-1 into exosomes in an Rab11a dependent manner. Collectively, these cascading actions lead to preventing the activation of the alcoholic induced brain inflammation signing pathway(s). This coordinated assembling of the HPCA/Rab11a/dectin-1 complex by oral administration of oatN may contribute to the prevention of brain inflammation.

The Normal Human Adult Hypothalamus Proteomic Landscape: Rise of Neuroproteomics in Biological Psychiatry and Systems Biology

The human hypothalamus is central to the regulation of neuroendocrine and neurovegetative systems, as well as modulation of chronobiology and behavioral aspects in human health and disease. Surprisingly, a deep proteomic analysis of the normal human hypothalamic proteome has been missing for such an important organ so far. In this study, we delineated the human hypothalamus proteome using a high-resolution mass spectrometry approach which resulted in the identification of 5349 proteins, while a multiple post-translational modification (PTM) search identified 191 additional proteins, which were missed in the first search. A proteogenomic analysis resulted in the discovery of multiple novel protein-coding regions as we identified proteins from noncoding regions (pseudogenes) and proteins translated from short open reading frames that can be missed using the traditional pipeline of prediction of protein-coding genes as a part of genome annotation. We also identified several PTMs of hypothalamic proteins that may be required for normal hypothalamic functions. Moreover, we observed an enrichment of proteins pertaining to autophagy and adult neurogenesis in the proteome data. We believe that the hypothalamic proteome reported herein would help to decipher the molecular basis for the diverse range of physiological functions attributed to it, as well as its role in neurological and psychiatric diseases. Extensive proteomic profiling of the hypothalamic nuclei would further elaborate on the role and functional characterization of several hypothalamus-specific proteins and pathways to inform future research and clinical discoveries in biological psychiatry, neurology, and system biology.

The transcriptome of anterior regeneration in earthworm Eudrilus eugeniae

The oligochaete earthworm, Eudrilus eugeniae is capable of regenerating both anterior and posterior segments. The present study focuses on the transcriptome analysis of earthworm E. eugeniae to identify and functionally annotate the key genes supporting the anterior blastema formation and regulating the anterior regeneration of the worm. The Illumina sequencing generated a total of 91,593,182 raw reads which were assembled into 105,193 contigs using CLC genomics workbench. In total, 40,946 contigs were annotated against the NCBI nr and SwissProt database and among them, 15,702 contigs were assigned to 14,575 GO terms. Besides a total of 9389 contigs were mapped to 416 KEGG biological pathways. The RNA-Seq comparison study identified 10,868 differentially expressed genes (DEGs) and of them, 3986 genes were significantly upregulated in the anterior regenerated blastema tissue samples of the worm. The GO enrichment analysis showed angiogenesis and unfolded protein binding as the top enriched functions and the pathway enrichment analysis denoted TCA cycle as the most significantly enriched pathway associated with the upregulated gene dataset of the worm. The identified DEGs and their function and pathway information can be effectively utilized further to interpret the key cellular, genetic and molecular events associated with the regeneration of the worm.

Promotive effects of tetrahydroxystilbene glucoside on the differentiation of neural stem cells from the mesencephalon into dopaminergic neurons

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the loss of midbrain dopaminergic (DA) neurons. Neural stem cells (NSCs) are the most promising cells for cell-replacement therapy for PD. However, the poor differentiation and maturation of DA neurons and decreased cell survival after transplantation are a challenge. Tetrahydroxystilbene glucoside (2,3,5,4'-tetrahydroxystilbene-2-O-glucoside; TSG), an active component of the popular traditional Chinese medicinal plant Polygonum multiflorum Thunb, possesses multiple pharmacological actions. In this study, we determined whether TSG can induce neural stem cell (NSCs) differentiation into neurons, especially DA neurons, and the possible involvement of Wnt/β-catenin signaling pathways. Results revealed that NSCs differentiated primarily into astrocytes when cultured in 2 % serum-containing medium. However, TSG treatment during NSC differentiation in vitro increased the number of Tuj-1-positive neurons, as well as the proportion of tyrosine hydroxylase(TH)-positive cells and dopamine- transporter- positive neurons, a late marker of mature DA neurons. We also found that TSG enhanced the expression of nuclear receptor related factor 1, a transcription factor specific for the development and maintenance of midbrain DA neurons in inducing NSC differentiation into TH -immunoreactive DA neurons. Moreover, TSG upregulated the expression of Wnt/β-catenin signaling molecules (Wnt1, Wnt3a, Wnt5a, and β-catenin). However, these promoting effects were significantly inhibited by the application of IWR1, a Wnt signaling-specific blocker in culture. Our findings suggested that TSG may have potential in inducing the DA neuronal differentiation of mouse NSCs mediated by triggering the Wnt/β-catenin signaling pathway. These results indicated the possible role for TSG in the transplantation of NSCs for PD.

MSC spheroids-loaded collagen hydrogels simultaneously promote neuronal differentiation and suppress inflammatory reaction through PI3K-Akt signaling pathway

It is critical for the clinical success to take the anti-inflammatory function into consideration when integrating the neurogenesis into the nerve repair materials. To this aim, we prepared mesenchymal stem cell (MSC) spheroids-loaded collagen (Col) hydrogels with combined superior anti-inflammatory efficacy and neurogenic activity. The size of the MSC spheroids showed a strong modulation effect on both functions, and the MSC spheroids-100 sample exhibited the best neuronal and anti-inflammatory potentials. The observed dual functions were likely based on the elevated intrinsic cell-cell contacts and cell-extracellular matrix interactions from the MSC spheroids. MSC self-assembly as spheroids expedited the secretions of endogenous trophic factors and extracellular matrix (ECM), which was beneficial to drive neural stem cell differentiation into the neuronal lineage. In addition, the formation of the MSC spheroids secreted more amounts and types of cytokines as well as immunomodulatory paracrine factors to suppress LPS-induced inflammatory reaction. LC-MS/MS analysis further demonstrated that MSC spheroids contributed to the activation of neuroactive ligand-receptor interaction, thereby triggering downstream PI3K-Akt signal pathway, which was likely due to the acceleration of ECM-receptor interaction, gap junction and tight junction. Importantly, inhibiting Akt pathway significantly suppressed the neuronal differentiation, indicating that PI3K-Akt signal pathway was critically involved in the Col-MSC spheroid hydrogel mediated neuroprotection and neurogenesis. Such findings not only provided a simple approach for improving MSC-based therapies for neuron-related diseases, but also shed insight on understanding the underlying mechanisms of MSC-mediated neuronal differentiation.

Effects of Physical Exercise on Autophagy and Apoptosis in Aged Brain: Human and Animal Studies

The aging process is characterized by a series of molecular and cellular changes over the years that could culminate in the deterioration of physiological parameters important to keeping an organism alive and healthy. Physical exercise, defined as planned, structured and repetitive physical activity, has been an important force to alter physiology and brain development during the process of human beings' evolution. Among several aspects of aging, the aim of this review is to discuss the balance between two vital cellular processes such as autophagy and apoptosis, based on the fact that physical exercise as a non-pharmacological strategy seems to rescue the imbalance between autophagy and apoptosis during aging. Therefore, the effects of different types or modalities of physical exercise in humans and animals, and the benefits of each of them on aging, will be discussed as a possible preventive strategy against neuronal death.

MicroRNA-24-3p regulates neuronal differentiation by controlling hippocalcin expression

Hippocalcin (HPCA) is a neuron-specific calcium-binding protein predominantly expressed in the nervous system. In the present study, we demonstrate that HPCA regulates neuronal differentiation in SH-SY5Y cells. We observed that the expression level of HPCA was increased during neuronal differentiation. Depletion of HPCA inhibited both neurite outgrowth and synaptophysin (SYP) expression, whereas overexpression of HPCA enhanced neuronal differentiation. Interestingly, we also found that the expression of HPCA mRNA was modulated by miR-24-3p. Using a dual-luciferase assay, we showed that co-transfection of a plasmid containing the miR-24-3p binding site from the 3'-untranslated region (3'UTR) of the HPCA gene and an miR-24-3p mimic effectively reduced luminescence activity. This effect was abolished when miR-24-3p seed sequences in the 3'UTR of the HPCA gene were mutated. miR-24-3p expression was decreased during differentiation, suggesting that the decreased expression level of miR-24-3p might have upregulated mRNA expression of HPCA. As expected, upregulation of miR-24-3p by an miRNA mimic led to reduced HPCA expression, accompanied by diminished neuronal differentiation. In contrast, downregulation of miR-24-3p by an antisense inhibitor promoted neurite outgrowth as well as levels of SYP expression. Taken together, these results suggest that miR-24-3p is an important miRNA that regulates neuronal differentiation by controlling HPCA expression.

Yokukansan, a Kampo medicine, enhances the level of neuronal lineage markers in differentiated P19 embryonic carcinoma cells

Yokukansan (YKS), a traditional Japanese Kampo medicine, affects neurological and psychiatric disorders. It ameliorates hippocampal neurogenesis in animals. However, its effect on neuronal cell differentiation remains unclear. Therefore, we investigated the effects of YKS on pluripotent P19 embryonic carcinoma cells as neuronal differentiation model cells.

Western blotting and immunocytochemistry revealed that 10 μg/mL YKS treatment during embryoid body formation or neuronal differentiation increased the expression of the neuronal stem cell marker, Nestin, by 1.9-fold and 1.7-fold, respectively, and of the mature neuron marker, NeuN, by 1.5-fold and 1.4-fold, respectively.

We examined the effect of YKS on intracellular signaling pathways in P19 cells and found significant elevation in phospho-PDK1 and phospho-mTOR expression (1.1-fold and 1.2-fold, respectively). Therefore, we investigated the effect of PDK1 and mTOR inhibitors on the level of neuronal lineage markers. We found that the mTOR inhibitor significantly abolished the YKS effect on the level of neuronal lineage markers.

Moreover, to identify the target(s) of YKS, antibody array analysis that simultaneously detects 16 phosphorylated proteins was performed. YKS significantly upregulated 10 phosphorylated proteins including PDK1, Akt, AMPK, PRAS40, mTOR, p70 S6 kinase, GSK-3α, Bad and ERK1/2 under cell proliferation conditions. These results suggest that YKS simultaneously activates multiple signaling pathways.

Thus, we concluded that YKS enhances the level of neuronal lineage markers in differentiated P19 cells, however it does not induce neuronal differentiation. Furthermore, mTOR is the predominant mediator of the YKS effect on these cells.

Calcium Sensors in Neuronal Function and Dysfunction

Calcium signaling in neurons as in other cell types can lead to varied changes in cellular function. Neuronal Ca²⁺ signaling processes have also become adapted to modulate the function of specific pathways over a wide variety of time domains and these can have effects on, for example, axon outgrowth, neuronal survival, and changes in synaptic strength. Ca²⁺ also plays a key role in synapses as the trigger for fast neurotransmitter release. Given its physiological importance, abnormalities in neuronal Ca²⁺ signaling potentially underlie many different neurological and neurodegenerative diseases. The mechanisms by which changes in intracellular Ca²⁺ concentration in neurons can bring about diverse responses is underpinned by the roles of ubiquitous or specialized neuronal Ca²⁺ sensors. It has been established that synaptotagmins have key functions in neurotransmitter release, and, in addition to calmodulin, other families of EF-hand-containing neuronal Ca²⁺ sensors, including the neuronal calcium sensor (NCS) and the calcium-binding protein (CaBP) families, play important physiological roles in neuronal Ca²⁺ signaling. It has become increasingly apparent that these various Ca²⁺ sensors may also be crucial for aspects of neuronal dysfunction and disease either indirectly or directly as a direct consequence of genetic variation or mutations. An understanding of the molecular basis for the regulation of the targets of the Ca²⁺ sensors and the physiological roles of each protein in identified neurons may contribute to future approaches to the development of treatments for a variety of human neuronal disorders.

Methyl 3,4-Dihydroxybenzoate Induces Neural Stem Cells to Differentiate Into Cholinergic Neurons in vitro

Neural stem cells (NSCs) have been shown as a potential source for replacing degenerated neurons in neurodegenerative diseases. However, the therapeutic potential of these cells is limited by the lack of effective methodologies for controlling their differentiation. Inducing endogenous pools of NSCs by small molecule can be considered as a potential approach of generating the desired cell types in large numbers. Here, we reported the characterization of a small molecule (Methyl 3,4-dihydroxybenzoate; MDHB) that selectively induces hippocampal NSCs to differentiate into cholinergic motor neurons which expressed synapsin 1 (SYN1) and postsynaptic density protein 95 (PSD-95). Studies on the mechanisms revealed that MDHB induced the hippocampal NSCs differentiation into cholinergic motor neurons by inhibiting AKT phosphorylation and activating autophosphorylation of GSK3β at tyrosine 216. Furthermore, we found that MDHB enhanced β-catenin degradation and abolished its entering into the nucleus. Collectively, this report provides the strong evidence that MDHB promotes NSCs differentiation into cholinergic motor neurons by enhancing gene Isl1 expression and inhibiting cell cycle progression. It may provide a basis for pharmacological effects of MDHB directed on NSCs.

Therapeutic potential of a phospholipase D1 inhibitory peptide fused with a cell-penetrating peptide as a novel anti-asthmatic drug in a Der f 2-induced airway inflammation model

Asthma is a chronic lung disease that causes airflow obstruction due to airway inflammation. However, its therapeutics remain inadequate. We previously reported that phospholipase D1 (PLD1) is a key enzyme involved in the production of pro-inflammatory cytokines in airway inflammation induced by the house dust mite allergen Dermatophagoides farinae 2 (Der f 2). We also revealed that PLD1 is specifically inactivated by AP180 (assembly protein, 180 kDa) and identified the PLD1-specific binding motif (TVTSP) of AP180. Therefore, the aims of this study were to develop a novel anti-asthmatic agent that could suppress airway inflammation by inhibiting PLD1 and examine its acute and chronic toxicity. We designed TAT-TVTSP, a PLD1-inhibitory peptide fused with a cell-penetrating peptide (CPP) delivery system. TAT-TVTSP was efficiently delivered to bronchial epithelial cells and significantly reduced Der f 2-induced PLD activation and Interleukin 13 (IL-13) production. Intranasally administered TAT-TVTSP was also efficiently transferred to airway tissues and ameliorated airway inflammation in a Der f 2-induced allergic asthma mouse model. Moreover, we investigated the safety of TAT-TVTSP as a therapeutic agent through single- and repeated-dose toxicity studies in a mouse model. Taken together, these results indicated that a PLD1-inhibitory peptide fused with a cell-penetrating peptide may be useful for treating allergic inflammatory asthma induced by house dust mites (HDMs).

A drug that targets a key enzyme involved in airway tissue inflammation shows promise in the treatment of allergic asthma. The enzyme phospholipase D1 (PLD1) triggers airway inflammation in allergic asthma brought on by house dust mites. Joong-Soo Han at Hanyang University in Seoul, Eung-Gook Kim at Chungbuk National University, Cheongju, South Korea, and co-workers have developed a treatment aimed at suppressing PLD1 and trialed the drug on mouse models of dust-mite allergy. The team designed a carrier system capable of accurately delivering a PLD1-inhibitory peptide to airway tissues and cells. They found that airway inflammation was significantly reduced in the treated mice. The drug appeared to be relatively safe when used in repeated doses, although further investigations are needed to verify this. The team hope their treatment will improve therapies for allergic asthma.

Phospholipase D1 Signaling: Essential Roles in Neural Stem Cell Differentiation

Phospholipase D1 (PLD1) is generally accepted as playing an important role in the regulation of multiple cell functions, such as cell growth, survival, differentiation, membrane trafficking, and cytoskeletal organization. Recent findings suggest that PLD1 also plays an important role in the regulation of neuronal differentiation of neuronal cells. Moreover, PLD1-mediated signaling molecules dynamically regulate the neuronal differentiation of neural stem cells (NSCs). Rho family GTPases and Ca²⁺-dependent signaling, in particular, are closely involved in PLD1-mediated neuronal differentiation of NSCs. Moreover, PLD1 has a significant effect on the neurogenesis of NSCs via the regulation of SHP-1/STAT3 activation. Therefore, PLD1 has now attracted significant attention as an essential neuronal signaling molecule in the nervous system. In the current review, we summarize recent findings on the regulation of PLD1 in neuronal differentiation and discuss the potential role of PLD1 in the neurogenesis of NSCs.

The construction of the multifunctional targeting ursolic acids liposomes and its apoptosis effects to C6 glioma stem cells

Brain gliomas, one of the most fatal tumors to human, severely threat the health and life of human. They are capable of extremely strong invasion ability. And invasive glioma cells could rapidly penetrate into normal brain tissues and break them. We prepared a kind of functional liposomes, which could be transported acrossing the blood-brain barrier (BBB) and afterwards induce the apoptosis of glioma stem cells. In this research, we chose ursolic acids (UA) as an anti-cancer drug to inhibit the growth of C6 glioma cells, while epigallocatechin 3-gallate(EGCG) as the agent that could induce the apoptosis of C6 glioma stem cells. With the targeting ability of MAN, the liposomes could be delivered through the BBB and finally were concentrated on the brain gliomas. Cell experiments in vitro demonstrated that the functional liposomes were able to significantly enhance the anti-cancer effects of the drugs due to promoting the apoptosis and endocytosis effects of C6 glioma cells and C6 glioma stem cells at the same time. Furthermore, the evaluations through animal models showed that the drugs could obviously prolong the survival period of brain glioma-bearing mice and inhibit the tumor growth. Consequently, multifunctional targeting ursolic acids liposomes could potentially improve the therapeutic effects on C6 glioma cells and C6 glioma stem cells.

Interleukin-6-Mediated Induced Pluripotent Stem Cell (iPSC)-Derived Neural Differentiation

In an aging society with an increasing threat to higher brain cognitive functions due to dementia, it becomes imperative to identify new molecular remedies for supporting adult neurogenesis. Interleukin-6 (IL-6) is a promising cytokine that can support neurogenesis under conditions of neurodegeneration, and neuron replacement is eventually possible due to its agonistic acting soluble receptor sIL-6R. Here, we report that activation of the IL-6-signal transducer and activator of transcription 3 (STAT3) axis is neurogenic and has potential therapeutic applications for the treatment of neurodegenerative diseases such as Parkinson's disease (PD).