Different Types Of Neuronal Cells Research Articles

Chemical characterization and multifunctional neuroprotective effects of sesquiterpenoid-enriched Inula britannica flowers extract

Dried flowers of Inula britannica commercially serve as pharmaceutical/nutraceutical herbs in the manufacture of medicinal products and functional tea that has been reported to possess extensive biological property. However, the neuroprotective constituents in I. britannica flowers are not known. In the current study, phytochemicals of sesquiterpenoid-enriched I. britannica flowers extract and their potential multifunctional neuroprotective effects were investigated. Nineteen structurally diverse sesquiterpenoids, including two new sesquiterpenoid dimers, namely, inubritanolides A and B (1, 2), and four new sesquiterpenoid monomers (3–6), namely, 1-O-acetyl-6-O-chloracetylbritannilactone (3), 6-methoxybritannilactone (4), 1-hydroxy-10β-methoxy-4αH-1,10-secoeudesma-5(6),11(13)-dien-12,8β-olide (5) and 1-hydroxy-4αH-1,10-secoeudesma-5(6),10(14),11(13)-trien-12,8β-olide (6), as well as 13 known congeners (7–19) were isolated from this source. The structures of compounds 1–6 were elucidated by 1D- and 2D- NMR and HR-ESI-MS data, and their absolute configurations were discerned by electronic circular dichroism (ECD) data analysis and single crystal X-ray diffraction. Interestingly, inubritannolide A (1) is a new type [4 + 2] Diels-Alder dimer featuring a hepta-membered cycloether skeleton. Most of the compounds showed potential multifunctional neuroprotective effects, including antioxidative, anti-neuroinflammatory, and microglial polarization properties. Specifically, 1 and 6 displayed slight strong neuroprotective potency against different types of neuronal cells mediated by various inducers including H2O2, 6-hydroxydopamine (6-OHDA), and lipopolysaccharide (LPS). Overall, this is the first report on multifunctional neuroprotective effects of sesquiterpenoid-enriched I. britannica flowers extract, which supports its potential pharmaceutical/nutraceutical application in neurodegenerative diseases.

Substantially thinner internal granular layer and reduced molecular layer surface in the cerebellar cortex of the Tc1 mouse model of down syndrome – a comprehensive morphometric analysis with active staining contrast-enhanced MRI

Down Syndrome is a chromosomal disorder that affects the development of cerebellar cortical lobules. Impaired neurogenesis in the cerebellum varies among different types of neuronal cells and neuronal layers. In this study, we developed an imaging analysis framework that utilizes gadolinium-enhanced ex vivo mouse brain MRI. We extracted the middle Purkinje layer of the mouse cerebellar cortex, enabling the estimation of the volume, thickness, and surface area of the entire cerebellar cortex, the internal granular layer, and the molecular layer in the Tc1 mouse model of Down Syndrome. The morphometric analysis of our method revealed that a larger proportion of the cerebellar thinning in this model of Down Syndrome resided in the inner granule cell layer, while a larger proportion of the surface area shrinkage was in the molecular layer.

Targeting RNA-Mediated Toxicity in C9orf72 ALS and/or FTD by RNAi-Based Gene Therapy

A hexanucleotide GGGGCC expansion in intron 1 of chromosome 9 open reading frame 72 (C9orf72) gene is the most frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The corresponding repeat-containing sense and antisense transcripts cause a gain of toxicity through the accumulation of RNA foci in the nucleus and deposition of dipeptide-repeat (DPR) proteins in the cytoplasm of the affected cells. We have previously reported on the potential of engineered artificial anti-C9orf72-targeting miRNAs (miC) targeting C9orf72 to reduce the gain of toxicity caused by the repeat-containing transcripts. In the current study, we tested the silencing efficacy of adeno-associated virus (AAV)5-miC in human-derived induced pluripotent stem cell (iPSC) neurons and in an ALS mouse model. We demonstrated that AAV5-miC transduces different types of neuronal cells and can reduce the accumulation of repeat-containing C9orf72 transcripts. Additionally, we demonstrated silencing of C9orf72 in both the nucleus and cytoplasm, which has an added value for the treatment of ALS and/or FTD patients. A proof of concept in an ALS mouse model demonstrated the significant reduction in repeat-containing C9orf72 transcripts and RNA foci after treatment. Taken together, these findings support the feasibility of a gene therapy for ALS and FTD based on the reduction in toxicity caused by the repeat-containing C9orf72 transcripts.

Pituitary Adenylyl Cyclase Activating Polypeptide (PACAP) Signaling and the Cell Cycle Machinery in Neurodegenerative Diseases.

Pituitary adenylyl cyclase activating polypeptide (PACAP) is a neuropeptide with great neuroprotective effects and remarkable therapeutic potential. PACAP activates several cellular pathways to exert its protective effects. Emerging evidence shows that PACAP can modify the levels and activity of cell cycle components involved in neurodegeneration to protect neurons from death. Cell cycle is a highly regulated process that controls the balance between proliferation, differentiation and death of every cell in the body. Aberrant expression and function of components of the cell cycle machinery have been linked to neurodegenerative diseases, in which different types of neuronal cells become dysfunctional and die in response to toxic insults. Since neurons are postmitotic cells, re-entry into the cell cycle has been shown to be pathological and contributes to the process of neurodegeneration. Moreover, an increasing number of studies highlight the importance of the role of cell cycle components outside the cell cycle and their involvement in neurodegenerative disorders. Here, we discuss the pleiotropic effects of PACAP on cell cycle machinery and the implication for the treatment of neurodegenerative diseases.

Propofol Induces Apoptosis of Neurons but Not Astrocytes, Oligodendrocytes, or Neural Stem Cells in the Neonatal Mouse Hippocampus

It has been shown that propofol can induce widespread apoptosis in neonatal mouse brains followed by long-term cognitive dysfunction. However, selective brain area and cell vulnerability to propofol remains unknown. This study was aimed to dissect toxic effect of propofol on multiple brain cells, including neurons, astrocytes, oligodendrocytes, and neural stem cells (NSCs). Seven-day-old mice were intraperitoneally administrated propofol or intralipid as a vehicle control for 6 hours. To identify vulnerable cells undergoing apoptosis following propofol exposure, brain sagittal sections were co-stained with antibodies against an apoptosis marker along with neuron, astrocyte, oligodendrocyte, or NSC markers using immunofluorescence staining. The results showed widespread apoptosis in propofol-treated brains (apoptotic cells: 1.55 ± 0.04% and 0.06 ± 0.01% in propofol group and intralipid-treated control group, respectively). Apoptotic cell distribution exhibits region- and cell-specific patterns. Several brain regions (e.g., cerebral cortex and hippocampus) were more vulnerable to propofol than other brain regions. Most apoptotic cells in the hippocampus were located in the cornus ammonis 1 (CA1) subfield. These apoptotic cells were only detected in neurons and not astrocytes, oligodendrocytes, or NSCs. These data demonstrate that different brain regions, subfields, and different types of neuronal cells in mice exhibit various vulnerabilities to propofol. Understanding region- and cell-specific susceptibility to propofol will help to better understand cellular contribution to developmental neurotoxicity and further develop novel therapeutic targets.

Fabrication and characterization of microsieve electrode array (µSEA) enabling cell positioning on 3D electrodes

Here the fabrication and characterization of a novel microelectrode array for electrophysiology applications is described, termed a micro sieve electrode array (µSEA). This silicon based µSEA device allows for hydrodynamic parallel positioning of single cells on 3D electrodes realized on the walls of inverted pyramidal shaped pores. To realize the µSEA, a previously realized silicon sieving structure is provided with a patterned boron doped poly-silicon, connecting the contact electrodes with the 3D sensing electrodes in the pores. A LPCVD silicon-rich silicon nitride layer was used as insulation. The selective opening of this insulation layer at the ends of the wiring lines allows to generate well-defined contact and sensing electrodes according to the layout used in commercial microelectrode array readers. The main challenge lays in the simultaneously selective etching of material at both the planar surface (contact electrode) as well as in the sieving structure containing the (3D) pores (sensing electrodes). For the generation of 3D electrodes in the pores a self-aligning technique was developed using the pore geometry to our advantage. This technique, based on sacrificial layer etching, allows for the fine tuning of the sensing electrode surface area and thus supports the positioning and coupling of single cells on the electrode surface in relation to the cell size. Furthermore, a self-aligning silicide is formed on the sensing electrodes to favour the electrical properties.Experiments were performed to demonstrate the working principle of the µSEA using different types of neuronal cells. Capture efficiency in the pores was >70% with a 70% survival rate of the cell maintained for up to 14 DIV.The TiSi2–boron-doped-poly-silicon sensing electrodes of the µSEA were characterized, which indicated noise levels of <15 µV and impedance values of 360 kΩ. These findings potentially allow for future electrophysiological measurements using the µSEA.

Determination of trans-resveratrol action on two different types of neuronal cells, neuroblastoma and hippocampal cells

Determination of trans-resveratrol action on two different types of neuronal cells, neuroblastoma and hippocampal cells

Design, Synthesis, and Biological Evaluation of (E)-3,4-Dihydroxystyryl Aralkyl Sulfones and Sulfoxides as Novel Multifunctional Neuroprotective Agents

Novel (E)-3,4-dihydroxystyryl aralkyl sulfones and sulfoxides were designed and synthesized as new analogues of 1, which showed interesting multifunctional neuroprotective effects, including antioxidative and antineuroinflammatory properties. Specifically, target compounds display excellent potency in scavenging reactive free radicals and demonstrate potent effects against various kinds of toxicities, including H2O2, 6-hydroxydopamine, and lipopolysaccharide in different types of neuronal cells. The antioxidative properties of the target compounds are more potent than that of 1, and the antineuroinflammatory properties are less strong than that of 1. According to the parallel artificial membrane permeation assay for the blood-brain barrier, target compounds possess greater blood-brain barrier (BBB) permeability than 1. In short, due to improvement of the antioxidative effect, stability, and BBB permeability, (E)-3,4-dihydroxystyryl aralkyl sulfones and sulfoxides can thus be considered as potential multifunctional neuroprotective agents and serve as new lead candidates in the treatment of neurodegenerative diseases.

Characterisation of diabetic retinal neuropathy in Ins2Akita mice

AbstractPurpose To characterize diabetic retinal neuropathy in the Ins2Akita mouse.Methods Male heterozygous Ins2Akita mice (2‐8 months of hyperglycemia) and C57BL/6J age‐matched siblings were used in this study. Retinal function was assessed by electroretinography (ERG) and thickness measured by optical coherence tomography. Eyes were then processed for immunostaining of different neuronal cells, including photoreceptors, bipolar, horizontal, amacrine and ganglion cells.Results Ins2Akita mice exhibited altered scotopic ERG after 6‐8 months of hyperglycemia. The reduction of outer and inner retinal thickness was observed after 2 months of diabetes. Despite no striking abnormalities were found in photoreceptors, a 40% reduction of photoreceptor synaptic ribbons was observed in Ins2Akita mice compared to age‐matched controls. This was accompanied by a total depletion of horizontal cell dendritic plexus and disarrangement of rod and cone bipolar cell processes at the outer plexiform layer. In the inner retina, the number of rod and cone bipolar cells remained similar to controls, but abnormal GABAergic amacrine cell stratification and 25% reduction of rod bipolar cell axon terminals were observed. Brn3a staining revealed a 20% loss of retinal ganglion cells, which exhibited abnormal aggregates of light neurofilament. In addition, a significant retinal vascular degeneration evidenced by around 50% reductions of vascular plexus was observed in 8 month hyperglycemic Ins2Akita mice. No evidence of retinal neovascularisation was detected.Conclusion Ins2Akita mice present a variety of retinal neuropathies including the reduction in different types of neuronal cells and disruption of synaptic structures. The mice also develop severe retinal vascular degeneration but no neovascularisation.

Mechanisms of Manganese-Induced Neurotoxicity in Primary Neuronal Cultures: The Role of Manganese Speciation and Cell Type

Manganese (Mn) is an essential trace element required for the proper functioning of a variety of physiological processes. However, chronic exposures to Mn can cause neurotoxicity in humans, especially when it occurs during critical stages of the central nervous system development. The mechanisms mediating this phenomenon as well as the contribution of Mn speciation and the sensitivity of different types of neuronal cells in such toxicity are poorly understood. This study was aimed to investigate the mechanisms mediating the toxic effects of MnCl(2), Mn(II) citrate, Mn(III) citrate, and Mn(III) pyrophosphate in primary cultures of neocortical (CTX) and cerebellar granular (CGC) neurons. Cell viability, mitochondrial function, and glutathione levels were evaluated after Mn exposure. CGC were significantly more susceptible to Mn-induced toxicity when compared with CTX. Moreover, undifferentiated CGC were more vulnerable to Mn toxicity than mature neurons. Mitochondrial dysfunction was observed after the exposure to all the tested Mn species. Ascorbate protected CGC against Mn-induced neurotoxicity, and this event seemed to be related to the dual role of ascorbate in neurons, acting as antioxidant and metabolic energetic supplier. CTX were protected from Mn-induced toxicity by ascorbate only when coincubated with lactate. These findings reinforce and extend the notion of the hazardous effects of Mn toward neuronal cells. In addition, the present results indicate that Mn-induced neurotoxicity is influenced by brain cell types, their origins, and developmental stages as well as by the chemical speciation of Mn, thus providing important information about Mn-induced developmental neurotoxicity and its risk assessment.

Molecular cloning, expression and tissue distribution of glial-cell-line-derived neurotrophic factor family receptor alpha-3 (GFRalpha-3).

Neurturin and glial-cell-line-derived neurotrophic factor (GDNF) promote the survival and maintenance of different types of neuronal cells and signal through a receptor complex composed of a ligand binding subunit, either GDNF family receptor alpha-1 (GFRalpha-1) or alpha-2 (GFRalpha-2), together with the cRET membrane-bound protein tyrosine kinase. We have cloned GFRalpha-3, a novel receptor belonging to the GFRalpha family, that is 35% identical by amino acid sequence to both GFRalpha-1 and GFRalpha-2. GFRalpha-3 is a protein composed of 400 amino acid residues with three potential N-linked glycosylation sites together with the features characteristic of a glycosyl-phosphatidylinositol-anchored membrane protein. The heterologous expression of a FLAG-tagged GFRalpha-3 in human embryonic kidney cells showed that the protein is bound to the cell surface via a glycosyl-PtdIns anchor and is glycosylated, with different glycoforms migrating on SDS/PAGE with apparent molecular masses ranging over 43-62 kDa. The gene for GFRalpha-3 was mapped to human chromosome 5 in a region (q31.1-q31.3) where several disease loci, growth factor and growth factor receptor genes have been localized. Using northern blot analysis or reverse-transcription PCR, GFRalpha-3 was shown to be expressed within the nervous system predominantly in the cerebellum and the spinal cord while in peripheral tissues GFRalpha-3 was found to be expressed mostly in the colon, small intestine, pancreas, heart, testis and prostate. Using a GFRalpha-3-specific [35S]cRNA[gammaS] probe, in situ hybridization histochemistry experiments confirmed the expression in the cerebellum.

The Thrombin Receptor in the Nervous System

Neurite retraction and reversal of astrocyte stellation triggered by the serine protease thrombin are receptor-mediated events. This article summarizes the current knowledge about the cellular effects that are induced by thrombin and its receptor in neural cells. The data presented show that the thrombin receptor messenger RNA is expressed in cultured astrocytes and that the reversal of stellation caused by thrombin in these cells is prevented by the protein kinase inhibitor staurosporine. Peptides based in sequence on the tethered ligand domain of the thrombin receptor were shown to mimic the effect of thrombin in most systems investigated. Platelets of some species, however, aggregate only in response to thrombin but not to the peptides. This observation is confirmed here. Rodent receptor-activating peptides did not cause aggregation of rat or mouse platelets. In contrast, all peptides triggered reversal of stellation in rat astrocytes and neurite retraction in mouse neuroblastoma cells, supporting the proposed mechanism of cleavage-induced receptor activation in neural cells. Finally, evidence is presented that serum withdrawal causes a decrease in the amount of the thrombin receptor mRNA in different types of neuronal cells. The possible role played by the thrombin receptor in the nervous system is discussed.