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Fulltext Promoting Neuro-Supportive Properties of Astrocytes with Epidermal Growth Factor Hydrogels

Chan SJ, Niu W, Hayakawa K, Hamanaka G, Wang X, Cheah PS, et al.

Stem Cells Transl Med, 2019 Dec;8(12):1242-1248.
PMID: 31483567 DOI: 10.1002/sctm.19-0159

Biomaterials provide novel platforms to deliver stem cell and growth factor therapies for central nervous system (CNS) repair. The majority of these approaches have focused on the promotion of neural progenitor cells and neurogenesis. However, it is now increasingly recognized that glial responses are critical for recovery in the entire neurovascular unit. In this study, we investigated the cellular effects of epidermal growth factor (EGF) containing hydrogels on primary astrocyte cultures. Both EGF alone and EGF-hydrogel equally promoted astrocyte proliferation, but EGF-hydrogels further enhanced astrocyte activation, as evidenced by a significantly elevated Glial fibrillary acidic protein (GFAP) gene expression. Thereafter, conditioned media from astrocytes activated by EGF-hydrogel protected neurons against injury and promoted synaptic plasticity after oxygen-glucose deprivation. Taken together, these findings suggest that EGF-hydrogels can shift astrocytes into neuro-supportive phenotypes. Consistent with this idea, quantitative-polymerase chain reaction (qPCR) demonstrated that EGF-hydrogels shifted astrocytes in part by downregulating potentially negative A1-like genes (Fbln5 and Rt1-S3) and upregulating potentially beneficial A2-like genes (Clcf1, Tgm1, and Ptgs2). Further studies are warranted to explore the idea of using biomaterials to modify astrocyte behavior and thus indirectly augment neuroprotection and neuroplasticity in the context of stem cell and growth factor therapies for the CNS. Stem Cells Translational Medicine 2019;8:1242&1248.

Matched MeSH terms: Neural Stem Cells/drug effects
Fulltext Growth Hormone Treatment Promotes Remote Hippocampal Plasticity after Experimental Cortical Stroke

Sanchez-Bezanilla S, Åberg ND, Crock P, Walker FR, Nilsson M, Isgaard J, et al.

Int J Mol Sci, 2020 Jun 26;21(12).
PMID: 32604953 DOI: 10.3390/ijms21124563

Cognitive impairment is common after stroke, and disturbances in hippocampal function are often involved, even in remote non-hippocampal injuries. In terms of hippocampal function, growth hormone (GH) is known to affects plasticity and cognition. We aimed to investigate whether GH treatment after an experimental cortical stroke could enhance remote hippocampal plasticity and the hippocampal-dependent visual discrimination task. C57BL6 male mice were subjected to cortical photothrombotic stroke. Stroke mice were then treated with either saline or GH at 48 h after occlusion for 28 days. We assessed learning and memory using mouse touchscreen platform for the visual discrimination task. We also evaluated markers of neural progenitor cells, synaptic plasticity and cerebrovascular remodelling in the hippocampal formation. GH treatment significantly improved the performance on visual discrimination task after stroke. We observed a concomitant increased number of bromodeoxyuridine-positive cells in the dentate gyrus of the hippocampus. We also detected increased protein levels and density of doublecortin, a neuronal precursor cells marker, as well as glutamate receptor 1 (GLuR1), a synaptic marker. These findings provide further neurobiological evidence for how GH treatment could be used to promote hippocampal plasticity in a remote region from the initial cortical injury, and thus enhance cognitive recovery after stroke.

Matched MeSH terms: Neural Stem Cells/drug effects*
Fulltext Pluripotent Human embryonic stem cell derived neural lineages for in vitro modelling of enterovirus 71 infection and therapy

Yap MS, Tang YQ, Yeo Y, Lim WL, Lim LW, Tan KO, et al.

Virol J, 2016 Jan 06;13:5.
PMID: 26738773 DOI: 10.1186/s12985-015-0454-6

The incidence of neurological complications and fatalities associated with Hand, Foot & Mouth disease has increased over recent years, due to emergence of newly-evolved strains of Enterovirus 71 (EV71). In the search for new antiviral therapeutics against EV71, accurate and sensitive in vitro cellular models for preliminary studies of EV71 pathogenesis is an essential prerequisite, before progressing to expensive and time-consuming live animal studies and clinical trials.

Matched MeSH terms: Neural Stem Cells/drug effects
Drug Encapsulated Nanoparticles for Treating Targeted Cells

Suk KH, Gopinath SCB

Curr Med Chem, 2017;24(30):3310-3321.
PMID: 28464786 DOI: 10.2174/0929867324666170502122444

BACKGROUND: Drug encapsulated nanoparticle has the potency to act as an effective antidote for various diseases. It is possible to enhance the bioavailability of drug encapsulated nanoparticle, whereby the yield is significantly higher compared to the standard formulation. The development with drug encapsulated nanoparticle has been improved drastically after demonstrating its capability of showing the enhanced thermophysical properties and stability of the drug. It is also utilized widely in cancer diagnoses, whereby the surface of the nanoparticle can be modified to enable the nanocarriers to reach the targeted location. Thus, the encapsulated nanoparticle can reveal neural stem cell differentiation due to the multifaceted nature and the biophysical cues to control the cell differentiation.
OBJECTIVE: In this overview, different advantages of the drug encapsulated nanoparticle for the downstream applications are narrated with its appealing characteristics.
CONCLUSION: The application of the drug encapsulated nanoparticle is unrestricted as it can be customized to the specific target cell in the living system.

Matched MeSH terms: Neural Stem Cells/drug effects
The NLRP3 inflammasome is involved in the neuroprotective mechanism of neural stem cells against microglia-mediated toxicity in SH-SY5Y cells via the attenuation of tau hyperphosphorylation and amyloidogenesis

Chan EWL, Krishnansamy S, Wong C, Gan SY

Neurotoxicology, 2019 01;70:91-98.
PMID: 30408495 DOI: 10.1016/j.neuro.2018.11.001

The cognitive impairment caused by Alzheimer's disease (AD) is associated with beta-amyloid (Aβ) and tau proteins, and is accompanied by inflammation. Recently, a novel inflammasome signaling pathway has been uncovered. Inflammasomes are implicated in the execution of inflammatory responses and pyroptotic death leading to neurodegeneration. Thus, the inflammasome signaling pathway could be a potential therapeutic target for AD. Neural stem cells (NSCs) are multipotent cells that can self-renew and differentiate into distinct neural cells. NSC therapy has been considered to be a promising therapeutic approach in protecting the central nervous system and restoring it following damage. However, the mechanisms involved remain unclear. The aims of this study were to investigate the protective effects of NE4C neural stem cells against microglia-mediated neurotoxicity and to explore molecular mechanisms mediating their actions. NE4C decreased the levels of caspase-1 and IL-1β, and attenuated the level of the NLRP3 inflammasome and its associated protein adapter, apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) in LPS-stimulated BV2 microglial cells, possibly by regulating the phosphorylation of p38α MAPK. The conditioned media obtained from co-culture of LPS-stimulated BV2 and NE4C cells exhibited protective effects on SH-SY5Y cells against microglia-mediated neurotoxicity; this was associated with an attenuation of tau phosphorylation and amyloidogenesis and accompanied by down-regulation of GSK-3β and p38α MAPK signalling pathways. In conclusion, the present study suggested that NSC therapy could be a potential strategy against microglia-mediated neurotoxicity. NSCs regulate NLRP3 activation and IL-1β secretion, which are critical in the initiation of the inflammatory responses, hence preventing the release of neurotoxic pro-inflammatory factors by microglia. This eventually reduces tau hyperphosphylation and amyloidogenesis, possibly through the regulation of GSK-3β and p38α MAPK signalling pathways, and thus protects SH-SY5Y cells against microglia-mediated neurotoxicity.

Matched MeSH terms: Neural Stem Cells/drug effects