scholarly journals Development of lipidoid nanoparticles for siRNA delivery to neural cells

2021 ◽  
Author(s):  
Purva Khare ◽  
Kandarp M. Dave ◽  
Yashika S Kamte ◽  
Muthiah A. Manoharan ◽  
Lauren A. O'Donnell ◽  
...  

Lipidoid nanoparticles (LNPs) are the delivery platform in Onpattro, the first FDA-approved siRNA drug. LNPs are also the carriers in the Pfizer-BioNTech and Moderna COVID-19 mRNA vaccines. While these applications have demonstrated that LNPs effectively deliver nucleic acids to hepatic and muscle cells, it is unclear if LNPs could be used for delivery of siRNA to neural cells, which are notoriously challenging delivery targets. Therefore, the purpose of this study was to determine if LNPs could efficiently deliver siRNA to neurons. Because of their potential utility in either applications in the central nervous system and the peripheral nervous system, we used both cortical neurons and sensory neurons. We prepared siRNA-LNPs using C12-200, a benchmark ionizable cationic lipidoid along with helper lipids. We demonstrated using dynamic light scattering that the inclusion of both siRNA and PEG-lipid provided a stabilizing effect to the LNP particle diameters and polydispersity indices by minimizing aggregation. We found that siRNA-LNPs were safely tolerated by primary dorsal root ganglion neurons. Flow cytometry analysis revealed that Cy5 siRNA delivered via LNPs into rat primary cortical neurons showed uptake levels similar to Lipofectamine RNAiMAX, the gold standard commercial transfection agent. However, LNPs demonstrated a superior safety profile whereas the Lipofectamine-mediated uptake was concomitant with significant toxicity. Fluorescence microscopy demonstrated a time-dependent increase in the uptake of LNP-delivered Cy5 siRNA in a human cortical neuron cell line. Overall, our results suggest that LNPs are a viable platform that can be optimized for delivery of therapeutic siRNAs to neural cells.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hyemin Kim ◽  
Jinyoung Lee ◽  
Yongcheol Cho

AbstractAxon regeneration in the central nervous system is inefficient. However, the neurons in the peripheral nervous system display robust regeneration after injury, indicating that axonal regeneration is differentially controlled under various conditions. To identify those molecules regulating axon regeneration, comparative analysis from dorsal root ganglion neurons at embryonic or adult stages is utilized, which reveals that PDK1 is functions as a negative regulator of axon regeneration. PDK1 is downregulated in embryonic neurons after axotomy. In contrast, sciatic nerve axotomy upregulated PDK1 at protein levels from adult mice. The knockdown of PDK1 or the chemical inhibition of PDK1 promotes axon regeneration in vitro and in vivo. Here we present PDK1 as a new player to negatively regulate axon regeneration and as a potential target in the development of therapeutic applications.


IBRO Reports ◽  
2019 ◽  
Vol 6 ◽  
pp. S124
Author(s):  
Woon-Hae Kim ◽  
Hyun-Gyu Kang ◽  
Taehoon H. Kim ◽  
Yoon Jeong Mo ◽  
Yu Seon Kim ◽  
...  

1987 ◽  
Vol 65 (5) ◽  
pp. 926-933 ◽  
Author(s):  
M. E. Morris ◽  
J. F. MacDonald ◽  
J. J. Friedlich ◽  
I. Szekelyhidi

Measurements made with two different techniques of intracellular calcium levels from small isolated cells of the mammalian central nervous system are described and compared. Recordings in cultured mouse embryo spinal cord and dorsal root ganglion neurons, made with double-barrelled borosilicate Ca2+-selective microelectrodes yielded a mean Ca2+ level of 2.3 (SE ± 0.54) μM for the lowest values recorded in 24 out of 46 cells. Intracellular Ca2+ dependence on membrane potential was apparent with levels of calcium ≥4 μM (r = 0.371, n = 29). Both cyclic fluctuations induced by tetraethylammonium and an apparent increase in Ca2+ evoked by the depolarizing excitatory amino acid, L-aspartate, were observed. In contrast, estimates of intracellular Ca2+ obtained by spectrofluorimetry of suspensions of mouse embryo brain cells, loaded with the intracellular Ca-binding fluorescent probe, quin2 provided a [Formula: see text]-fold lower value, 152 (SE ± 7) nM. This more closely resembles levels reported for large neurons where large-tip microelectrodes with greater sensitivity were used, and in spite of the heterogeneity of the cells this value is presumed to be a more accurate estimate of intraneuronal Ca2+ concentration. In these fluorescence studies KCl readily evoked increases in intracellular Ca2+ which could be blocked by verapamil and Cd2+ and were not induced in the absence of Ca2+. Increases were also produced by N-methyl-D-aspartate, but not by the kainate-like Lathyrus neurotoxin, L-3-oxalylamino-2-aminopropionic acid. These results provide preliminary evidence for both voltage-sensitive and receptor-activated Ca channels in embryonic brain cells. Although the recording of intraneuronal Ca2+ with conventional ion-selective microelectrodes in small cells has problems with respect to accuracy, stability, and time constant, recent advances in the design of Ca2+ sensors and electrodes are promising. These, as well as developments in techniques of single cell fluorescence analysis, now offer methods with improved and powerful capacity for accurate and simultaneous measurements of intracellular Ca2+ and membrane electrophysiological parameters.


2010 ◽  
Vol 79 (3) ◽  
pp. 1363-1373 ◽  
Author(s):  
Jianchun Xiao ◽  
Lorraine Jones-Brando ◽  
C. Conover Talbot ◽  
Robert H. Yolken

ABSTRACTStrain type is one of the key factors suspected to play a role in determining the outcome ofToxoplasmainfection. In this study, we examined the transcriptional profile of human neuroepithelioma cells in response to representative strains ofToxoplasmaby using microarray analysis to characterize the strain-specific host cell response. The study of neural cells is of interest in light of the ability ofToxoplasmato infect the brain and to establish persistent infection within the central nervous system. We found that the extents of the expression changes varied considerably among the three strains. Neuroepithelial cells infected withToxoplasmatype I exhibited the highest level of differential gene expression, whereas type II-infected cells had a substantially smaller number of genes which were differentially expressed. Cells infected with type III exhibited intermediate effects on gene expression. The three strains also differed in the individual genes and gene pathways which were altered following cellular infection. For example, gene ontology (GO) analysis indicated that type I infection largely affects genes related to the central nervous system, while type III infection largely alters genes which affect nucleotide metabolism; type II infection does not alter the expression of a clearly defined set of genes. Moreover, Ingenuity Pathways Analysis (IPA) suggests that the three lineages differ in the ability to manipulate their host; e.g., they employ different strategies to avoid, deflect, or subvert host defense mechanisms. These observed differences may explain some of the variation in the neurobiological effects of different strains ofToxoplasmaon infected individuals.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
José Fernando Maya-Vetencourt ◽  
Laura Baroncelli ◽  
Alessandro Viegi ◽  
Ettore Tiraboschi ◽  
Eero Castren ◽  
...  

The central nervous system architecture is markedly modified by sensory experience during early life, but a decline of plasticity occurs with age. Recent studies have challenged this dogma providing evidence that both pharmacological treatments and paradigms based on the manipulation of environmental stimulation levels can be successfully employed as strategies for enhancing plasticity in the adult nervous system. Insulin-like growth factor 1 (IGF-1) is a peptide implicated in prenatal and postnatal phases of brain development such as neurogenesis, neuronal differentiation, synaptogenesis, and experience-dependent plasticity. Here, using the visual system as a paradigmatic model, we report that IGF-1 reactivates neural plasticity in the adult brain. Exogenous administration of IGF-1 in the adult visual cortex, indeed, restores the susceptibility of cortical neurons to monocular deprivation and promotes the recovery of normal visual functions in adult amblyopic animals. These effects were accompanied by a marked reduction of intracortical GABA levels. Moreover, we show that a transitory increase of IGF-1 expression is associated to the plasticity reinstatement induced by environmental enrichment (EE) and that blocking IGF-1 action by means of the IGF-1 receptor antagonist JB1 prevents EE effects on plasticity processes.


2001 ◽  
Vol 81 (2) ◽  
pp. 871-927 ◽  
Author(s):  
Nicole Baumann ◽  
Danielle Pham-Dinh

Oligodendrocytes, the myelin-forming cells of the central nervous system (CNS), and astrocytes constitute macroglia. This review deals with the recent progress related to the origin and differentiation of the oligodendrocytes, their relationships to other neural cells, and functional neuroglial interactions under physiological conditions and in demyelinating diseases. One of the problems in studies of the CNS is to find components, i.e., markers, for the identification of the different cells, in intact tissues or cultures. In recent years, specific biochemical, immunological, and molecular markers have been identified. Many components specific to differentiating oligodendrocytes and to myelin are now available to aid their study. Transgenic mice and spontaneous mutants have led to a better understanding of the targets of specific dys- or demyelinating diseases. The best examples are the studies concerning the effects of the mutations affecting the most abundant protein in the central nervous myelin, the proteolipid protein, which lead to dysmyelinating diseases in animals and human (jimpy mutation and Pelizaeus-Merzbacher disease or spastic paraplegia, respectively). Oligodendrocytes, as astrocytes, are able to respond to changes in the cellular and extracellular environment, possibly in relation to a glial network. There is also a remarkable plasticity of the oligodendrocyte lineage, even in the adult with a certain potentiality for myelin repair after experimental demyelination or human diseases.


2018 ◽  
Vol 98 (1) ◽  
pp. 239-389 ◽  
Author(s):  
Alexei Verkhratsky ◽  
Maiken Nedergaard

Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.


2016 ◽  
Vol 74 (8) ◽  
pp. 671-678 ◽  
Author(s):  
Roberto E. Sica ◽  
Roberto Caccuri ◽  
Cecilia Quarracino ◽  
Francisco Capani

ABSTRACT Experimental evidence suggests that astrocytes play a crucial role in the physiology of the central nervous system (CNS) by modulating synaptic activity and plasticity. Based on what is currently known we postulate that astrocytes are fundamental, along with neurons, for the information processing that takes place within the CNS. On the other hand, experimental findings and human observations signal that some of the primary degenerative diseases of the CNS, like frontotemporal dementia, Parkinson’s disease, Alzheimer’s dementia, Huntington’s dementia, primary cerebellar ataxias and amyotrophic lateral sclerosis, all of which affect the human species exclusively, may be due to astroglial dysfunction. This hypothesis is supported by observations that demonstrated that the killing of neurons by non-neural cells plays a major role in the pathogenesis of those diseases, at both their onset and their progression. Furthermore, recent findings suggest that astrocytes might be involved in the pathogenesis of some psychiatric disorders as well.


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