Questo lavoro è supportato dall&#39;Ufficio di Ricerca e Sviluppo, Ricerca medica Service, Department of Veterans Affairs. Questo studio è stato finanziato da un premio VA recensione Merit (per MCL) e la University of Tennessee Health Science Fondo sclerosi multipla Research Center.

1. Anticorpo Labeling (Figura 1) <ol><li> Fai 0.1 M NaHCO 3 buffer: <ul type="circle"><li> 8,4 g NaHCO 3 </li><li> 29,2 g NaCl </li><li> 1 litro H 2 O </li></ul></li><li> Portare il buffer fino ad un pH di 8,4 con questa soluzione (10,6 g di Na 2 CO 3, 29,2 g di NaCl, 1 litro H 2 0). </li><li> Aggiungere 35 ul Atto550 NHS a 70 pl pl NaHCO anti-hnRNPA1 e 500 3 tampone e ruotarlo per 1 ora a temperatura ambiente. Dopo un&#39;ora di rotazione, iniettare il composto in un dializzatore e dializza in 2 litri di PBS durante la notte. </li><li> Il giorno dopo, concentrare i dializzati Atto550 NHS anti-hnRNPA1 utilizzando una colonna di spin (Amicon Ultra 0.5). </li><li> Dopo le Atto550 NHS marcato anti-hnRNPA1 anticorpo è stato concentrato, nano-drop campione per determinare la concentrazione. </li></ol> 2. Anticorpo trasfezione (Figura 2) <ol><li> Seed 10 5 cellule / pozzetto in 500 pl di Dulbecco di Eagle modificato Medio (DMEM/F12 10% FBS 1% antibiotico) in un pozzetto 8 slitta 24 ore prima della trasfezione. Confluenza cellulare deve essere almeno il 70%. </li><li> Ventiquattro ore dopo la semina, aggiungere 2 ml di Ab-DeliverIN reagenti in una provetta Eppendorf. </li><li> Successivamente, aggiungere 2 ug di Atto550 NHS etichettati hnRNPA1 anticorpo anti-(0,5 pg / pl) allo stesso tubo Eppendorf e incubare 10-15 min a RT. </li><li> Durante l&#39;incubazione, aspirare media e aggiungere 394 ml di DMEM fresco supporto alle cellule. </li></ol> Nota: Aggiungere 500 microlitri DMEM ad una camera di cellule intatte per fungere da controllo. <ol start="5"><li> Dopo l&#39;incubazione, aggiungere 100 ml di DMEM alla miscela di anticorpi, mescolare pipettando su e giù, e aggiungere alle cellule in DMEM per un volume totale di 500 microlitri. </li><li> Modificare i media dopo 48 ore di consegna anticorpi. </li></ol> Nota: protocollo è stato ripetuto con FITC Rigg etichettato come controllo positivo. 3. Imaging Live e stabiliti per determinare l&#39;efficienza <ol><li> Celle di immagine, vivono a 48 ore utilizzando i Cy3 filtro su un microscopio a fluorescenza per l&#39;immagine del trasfettate Atto550 NHS anticorpi marcati. </li><li> Dopo l&#39;imaging dal vivo è stata completata, aspirare i media e le cellule fisse. </li><li> Dopo mezzi aspiranti, il trattamento di cellule con 0,4% paraformaldeide per 15 min a temperatura ambiente. Lavare le cellule 4 x 5 min ciascuna con PBS. Poi, montare cellule con mezzi di montaggio contenenti reagenti DAPI e applicare il coprioggetto correzione. Misurare l&#39;efficienza di trasfezione delle cellule fisse con AxioVision software. Se AxioVision software non è a portata di mano, basta contare gli eventi dall&#39;immagine i risultati a mano e inserire nel calcolo in 3.7. In alternativa, il software ImageJ può essere utilizzato per questi calcoli. </li><li> In primo luogo, utilizzare la misurazione &quot;Eventi&quot; per contare il numero totale di celle nella vostra immagine di scelta un ingrandimento 20x. </li><li> Successivamente, utilizzare la misurazione &quot;Eventi&quot; per contare le cellule che non eranosuccesso trasfettate con anticorpi nella stessa 20x ingrandimenti. </li><li> Per accedere ai misurati &quot;Eventi&quot; in un formato stile Excel, fare clic su &quot;Proprietà&quot;, fare clic sulla scheda &quot;Misura&quot;, e fare clic per visualizzare &quot;come tabella.&quot; </li><li> Infine, utilizzare il seguente calcolo per determinare l&#39;efficienza di trasfezione confrontando i due eventi misurate in precedenza: ((Totale cellule - cellule non trasfettate) / cellule totali) x 100 = La trasfezione di efficienza. </li></ol> 4. Risultati rappresentativi Le immagini live non trasfettate (Figura 3A) rispetto al trasfettate (Figura 3B) neuroni rivelano che l&#39;etichettatura degli anticorpi (rosso o verde in ogni figura) è chiaramente osservata nelle cellule (Figura 3B, C, D). Seguendo aspirazione e lavaggio con mezzi per rimuovere gli anticorpi o tra aderenti alla superficie delle cellule, anticorpi marcati sono ancora presenti all&#39;interno dei neuroni (Figura 3C, D).<html> Per calcolare l&#39;efficienza di trasfezione, utilizzare il software AxioVision per calcolare cellule totali rispetto alle cellule che non sono state transfettate con successo. Questi valori sono stati inseriti in una formula efficienza di trasfezione di acquisire l&#39;efficienza di trasfezione come percentuale di cellule totali (Figura 4). <img alt="Figura 1" src="/files/ftp_upload/4154/4154fig1.jpg" /> Figura 1. Diagramma di flusso delle procedure utilizzate per gli anticorpi etichette con la 550 Atto NHS estere seguita da passaggi necessari per concentrare gli anticorpi marcati. <a href="http://www.jove.com/files/ftp_upload/4154/4154fig1large.jpg" target="_blank">Clicca qui per ingrandire la figura</a> . <img alt="Figura 2" src="/files/ftp_upload/4154/4154fig2.jpg" /> Figura 2. Diagramma di flusso delle procedure utilizzate per trasfettare anticorpi marcati nelle cellule vive in coltura.arge.jpg &quot;target =&quot; _blank &quot;&gt; Clicca qui per ingrandire la figura. <img alt="Figura 3" src="/files/ftp_upload/4154/4154fig3.jpg" /> Figura 3. Immagini in diretta dei neuroni trasfettati trasfezione 48 ore di seguito. <img alt="Figura 4" src="/files/ftp_upload/4154/4154fig4.jpg" /> Figura 4. Fisso e risciacquati immagini con eventi contati per determinare l&#39;efficienza di trasfezione.

<ol>
	<li>Burkhardt, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epitope-specific+recognition+of+type+II+collagen+by+rheumatoid+arthritis+antibodies+is+shared+with+recognition+by+antibodies+that+are+arthritogenic+in+collagen-induced+arthritis+in+the+mouse.">Epitope-specific recognition of type II collagen by rheumatoid arthritis antibodies is shared with recognition by antibodies that are arthritogenic in collagen-induced arthritis in the mouse.</a> Arthritis Rheum. 46, 2339-2348 (2002).</li><li>Chester, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lambert-Eaton+syndrome+antibodies:+reaction+with+membranes+from+a+small+cell+lung+cancer+xenograft.">Lambert-Eaton syndrome antibodies: reaction with membranes from a small cell lung cancer xenograft.</a> J. Neuroimmunol. 18, 97-104 (1988).</li><li>Lee, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HTLV-1+induced+molecular+mimicry+in+neurological+disease.">HTLV-1 induced molecular mimicry in neurological disease.</a> Curr. Top Microbiol. Immunol. 29, 125-136 (2005).</li><li>Reeves, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systemic+lupus+erythematosus.+Antibodies+to+DNA,+DNA-binding+proteins,+and+histones.">Systemic lupus erythematosus. Antibodies to DNA, DNA-binding proteins, and histones.</a> Rheum. Dis. Clin. North Am. 20, 1-28 (1994).</li><li>Levin, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoimmunity+due+to+molecular+mimicry+as+a+cause+of+neurological+disease.">Autoimmunity due to molecular mimicry as a cause of neurological disease.</a> Nat. Med. 8, 509-513 (2002).</li><li>Lee, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoantibodies+that+recognize+functional+domains+of+hnRNPA1+implicate+molecular+mimicry+in+the+pathogenesis+of+neurological+disease.">Autoantibodies that recognize functional domains of hnRNPA1 implicate molecular mimicry in the pathogenesis of neurological disease.</a> Neurosci. Lett. 401, 188-193 (2006).</li><li>Kalume, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mimicry:+cross-reactive+antibodies+from+patients+with+immune-mediated+neurologic+disease+inhibit+neuronal+firing.">Molecular mimicry: cross-reactive antibodies from patients with immune-mediated neurologic disease inhibit neuronal firing.</a> J. Neurosci. Res. 77, 82-89 (2004).</li><li>Levin, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cross-reactivity+between+immunodominant+human+T+lymphotropic+virus+type+I+tax+and+neurons:+implications+for+molecular+mimicry.">Cross-reactivity between immunodominant human T lymphotropic virus type I tax and neurons: implications for molecular mimicry.</a> J. Infect. Dis. 186, 1514-1517 (2002).</li><li>Lee, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+potential+link+between+autoimmunity+and+neurodegeneration+in+immune-mediated+neurological+disease.">A potential link between autoimmunity and neurodegeneration in immune-mediated neurological disease.</a> J. Neuroimmunol. 235, 56-69 (2011).</li><li>Smeenk, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antinuclear+antibodies:+cause+of+disease+or+caused+by+disease.">Antinuclear antibodies: cause of disease or caused by disease.</a> Rheumatology (Oxford). 39, 581-584 (2000).</li><li>Lee, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Post-translational+glycosylation+of+target+proteins+implicate+molecular+mimicry+in+the+pathogenesis+of+HTLV-1+associated+neurological+disease.">Post-translational glycosylation of target proteins implicate molecular mimicry in the pathogenesis of HTLV-1 associated neurological disease.</a> J. Neuroimmunol. 204, 140-148 (2008).</li><li>Reisinger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum-free+transfection+of+CHO+cells+with+chemically+defined+transfection+systems+and+investigation+of+their+potential+for+transient+and+stable+transfection.">Serum-free transfection of CHO cells with chemically defined transfection systems and investigation of their potential for transient and stable transfection.</a> Cytotechnology. 60, 115-123 (2009).</li><li>Weill, C. O., Biri, S., Erbacher, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cationic+lipid-mediated+intracellular+delivery+of+antibodies+into+live+cells.">Cationic lipid-mediated intracellular delivery of antibodies into live cells.</a> Biotechniques. 44, Pvii-Pxi (2008).</li><li>Radic, M. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterogeneous+nuclear+ribonucleoprotein+P2+is+an+autoantibody+target+in+mice+deficient+for+Mer,+Axl,+and+Tyro3+receptor+tyrosine+kinases.">Heterogeneous nuclear ribonucleoprotein P2 is an autoantibody target in mice deficient for Mer, Axl, and Tyro3 receptor tyrosine kinases.</a> J. Immunol. 176, 68-74 (2006).</li><li>Vincent, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Successful+'passive+transfer'+of+paraneoplastic+stiff+person+syndrome+with+antibodies+to+an+intracellular+antigen.">Successful 'passive transfer' of paraneoplastic stiff person syndrome with antibodies to an intracellular antigen.</a> Brain. 133, 3164-3165 (2010).</li><li>Vincent, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stiff,+twitchy+or+wobbly:+are+GAD+antibodies+pathogenic.">Stiff, twitchy or wobbly: are GAD antibodies pathogenic.</a> Brain. 131 (Pt 10), 2536-2537 (2008).</li><li>Magrys, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+anti-alpha-enolase+autoantibodies+in+pathogenicity+of+autoimmune-mediated+retinopathy.">The role of anti-alpha-enolase autoantibodies in pathogenicity of autoimmune-mediated retinopathy.</a> J. Clin. Immunol. 27, 181-192 (2007).</li><li>Geis, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stiff+person+syndrome-associated+autoantibodies+to+amphiphysin+mediate+reduced+GABAergic+inhibition.">Stiff person syndrome-associated autoantibodies to amphiphysin mediate reduced GABAergic inhibition.</a> Brain. 133, 3166-3180 (2010).</li></ol>

Nessun conflitto di interessi dichiarati.

Al fine di verificare ipotesi circa molecole specifiche e la loro espressione, altri geni e vettori sono comunemente trasfettati in cellule. L&#39;aspetto unico di questo procedimento è la possibilità di trasfettare facilmente anticorpi nelle cellule bersaglio. Abbiamo eseguito questo metodo in cinque esperimenti separati ciascuno in duplicati. Risultati di efficienza di trasfezione erano simili in tutti gli esperimenti. Soprattutto, il metodo permette l&#39;inserimento di anticorpi nella cellula senza alterare la str...

<table border="1"><tbody><tr><td> Nome del reagente </td><td> Azienda </td><td> Numero di catalogo </td></tr><tr><td> Fluorescente Microscopio AxioObserver A1 </td><td> Zeiss </td><td></td></tr><tr><td> AxioVision versione 4.2 </td><td> Zeiss </td><td></td></tr><tr><td> Anti-rhnRNPA1 </td><td> Abcam </td><td> Ab4791 </td></tr><tr><td> Marcato con FITC anti-Rigg </td><td> OZ Biosciences </td><td> AI20100 </td></tr><tr><td> Atto550 NHS estere </td><td> Sigma </td><td> 92835 </td></tr><tr><td> Ab-DeliverIN </td><td> OZ Biosciences </td><td> AI20100 </td></tr><tr><td> DMEM/F12 +10% FBS antibiotici +1% </td><td> Gibco </td><td> 11320-033 </td></tr><tr><td> Poly-D-Lisina 8 pozzetti Cultura Slides </td><td> BD </td><td> 354632 </td></tr><tr><td> Multi-Purpose Rotator </td><td> Scientifico Industries Inc </td><td> Modello 151 </td></tr><tr><td> DAPI Montaggio supporti </td><td> Millipore </td><td> S7113 </td></tr><tr><td> PBS </td><td> Ambion </td><td> 9626 </td></tr><tr><td> Dializzatore </td><td> Thermo Fisher Scientific </td><td> 66380 </td></tr><tr><td> Amicon Ultra-0.5 </td><td> Millipore </td><td> UFC501096 </td></tr><tr><td> Paraformaldeide (4% soluzione) </td><td> Scienze della microscopia elettronica </td><td></td></tr><tr><td> Nano-Drop </td><td> Thermo Fisher Scientific </td><td></td></tr></tbody></table>

antibody transfection into neurons as a tool to study disease pathogenesis

Anticorpi fornire la capacità di ottenere informazioni romanzo in vari eventi che si svolgono in sistemi viventi. La capacità di produrre anticorpi altamente specifici per le proteine ​​bersaglio ha consentito di questioni biologiche molto precise da affrontare. Soprattutto, gli anticorpi sono stati implicati nella patogenesi di numerose malattie umane comprendenti lupus eritematoso sistemico (SLE), artrite reumatoide (RA), sindromi paraneoplastiche, sclerosi multipla (SM) e umane T linfotropico virus di tipo 1 (HTLV-1) mielopatia associata / paraparesi spastica tropicale (HAM / TSP) 1-9. Come anticorpi causano la malattia è una zona di un&#39;indagine in corso, ed i dati suggeriscono che le interazioni tra gli anticorpi e molecole intracellulari vari risultati in infiammazione, alterazione cellulare di messaggistica, e l&#39;apoptosi 10. E &#39;stato dimostrato che i pazienti con SM e HAM / TSP produrre autoanticorpi al intracellulare di RNA binding protein proteine ​​eterogenee ribonuclear A1 (hnRNP A1) 3, 5-7, 9, 11. Dati recenti indicano che gli anticorpi per intra-neuronale e antigeni di superficie sono patogeni 3, 5-9, 11. Pertanto, un procedimento che consente lo studio di anticorpo intracellulare: proteina presterebbe grande intuizione patogenesi della malattia. I geni sono comunemente trasfettati in cellule primarie e linee cellulari in coltura, tuttavia trasfezione in cellule di anticorpi è stato ostacolato dalla alterazione della struttura anticorpo o scarsa efficienza di transfezione 12. Altri metodi di trasfezione includono trasfezione anticorpo basato su liposomi cationici (costituito DOTAP / DOPE) e polyethylenimines (PEI), entrambi i quali ha determinato un decremento di dieci volte nella trasfezione anticorpo rispetto ai controlli 12. Il metodo eseguito nel nostro studio è simile a lipidi cationici-mediate metodi e utilizza una base lipidica meccanismo per formare non covalenti complessi con gli anticorpi attraverso elettrostatica e hydrinterazioni ophobic 13. Abbiamo utilizzato Ab-DeliverIN reattivo, che è una formulazione lipidica in grado di catturare anticorpi attraverso interazioni elettrostatiche e idrofobi non-covalenti e depositarli all&#39;interno delle cellule. Così chimica e genetica accoppiamenti non sono necessari per la consegna di anticorpi funzionali nelle cellule viventi. Questo metodo ci ha permesso di eseguire l&#39;analisi degli anticorpi vari esperimenti e localizzazione della proteina, così come le analisi delle conseguenze molecolari di anticorpi intracellulari: interazioni delle proteine ​​9. In questo protocollo, si mostrerà come trasfettare anticorpi in neuroni rapida, riproducibile e con un elevato grado di efficienza di trasfezione. A titolo di esempio, useremo anticorpi anti-hnRNP A1 e anti-IgG. Per la quantificazione facile di efficienza di trasfezione abbiamo utilizzato anticorpi anti-A1 hnRNP etichettati con Atto-550-NHS e marcato con FITC IgG. Atto550 NHS è una nuova etichetta ad alto assorbimento molecolare e quantistica yiELD. Fonte di eccitazione e filtri fluorescenti per Atto550 sono simili a Cy3 (Es. 556 Em. 578). Inoltre, Atto550 ha fotostabilità alta. Marcato con FITC IgG sono stati utilizzati come controllo per dimostrare che questo metodo è versatile e non tingere dipendente. Questo approccio e i dati generati aiuterà nella comprensione del ruolo che gli anticorpi per antigeni bersaglio intracellulare potrebbe svolgere nella patogenesi delle malattie umane.

Watch this Scientific Journal Video about Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis at JoVE.com

Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis

Un approccio rapido per investigare le interazioni e gli effetti sui meccanismi molecolari legati alla presenza di anticorpi in un ambiente intracellulare viene descritto. Il metodo comporta la transfezione di anticorpi nelle cellule vive utilizzando un non-covalente formazione del complesso basato su una formulazione lipidica. La tecnica è adattabile a linee cellulari immortalizzate e cellule primarie.

Trasfezione anticorpo in neuroni come strumento per studiare patogenesi della malattia

Antibodies provide the ability to gain novel insight into various events taking place in living systems.  The ability to produce highly specific ...

antibody-transfection-into-neurons-as-tool-to-study-disease

Research

JoVE Journal

Neuroscience

10.7K Views.  Veterans Administration Medical Center, Memphis, TN. Un approccio rapido per investigare le interazioni e gli effetti sui meccanismi molecolari legati alla presenza di anticorpi in un ambiente intracellulare viene descritto. Il metodo comporta la transfezione di anticorpi nelle cellule vive utilizzando un non-covalente formazione del complesso basato su una formulazione lipidica. La tecnica è adattabile a linee cellulari immortalizzate e cellule primarie.

Video: Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis

Laser Capture Microdissection of Drosophila Peripheral Neurons

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the molecular mechanisms underlying class-specific dendrite morphogenesis1,2. To facilitate molecular analyses of class-specific da neuron development, it is vital to obtain these cells in a pure population. Although a range of different cell, and tissue-specific RNA isolation techniques exist for Drosophila cells, including magnetic bead based cell purification3,4, Fluorescent Activated Cell Sorting (FACS)5-8, and RNA binding protein based strategies9, none of these methods can be readily utilized for isolating single or multiple class-specific Drosophila da neurons with a high degree of spatial precision. Laser Capture Microdissection (LCM) has emerged as an extremely powerful tool that can be used to isolate specific cell types from tissue sections with a high degree of spatial resolution and accuracy. RNA obtained from isolated cells can then be used for analyses including qRT-PCR and microarray expression profiling within a given cell type10-16. To date, LCM has not been widely applied in the analysis of Drosophila tissues and cells17,18, including da neurons at the third instar larval stage of development. 
Here we present our optimized protocol for isolation of Drosophila da neurons using the infrared (IR) class of LCM. This method allows for the capture of single, class-specific or multiple da neurons with high specificity and spatial resolution. Age-matched third instar larvae expressing a UAS-mCD8::GFP19 transgene under the control of either the class IV da neuron specific ppk-GAL420 driver or the pan-da neuron specific 21-7-GAL421 driver were used for these experiments. RNA obtained from the isolated da neurons is of very high quality and can be directly used for downstream applications, including qRT-PCR or microarray analyses. Furthermore, this LCM protocol can be readily adapted to capture other Drosophila cell types a various stages of development dependent upon the cell type specific, GAL4-driven expression pattern of GFP.

Laser Capture Microdissection of Drosophila Peripheral Neurons

In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses.

Laser Microdissezione Cattura di Drosophila Neuroni periferici

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the ...

Ricerca

Neuroscienze

Cut-loading: A Useful Tool for Examining the Extent of Gap Junction Tracer Coupling Between Retinal Neurons

In addition to chemical synaptic transmission, neurons that are connected by gap junctions can also communicate rapidly via electrical synaptic transmission. Increasing evidence indicates that gap junctions not only permit electrical current flow and synchronous activity between interconnected or coupled cells, but that the strength or effectiveness of electrical communication between coupled cells can be modulated to a great extent1,2. In addition, the large internal diameter (~1.2 nm) of many gap junction channels permits not only electric current flow, but also the diffusion of intracellular signaling molecules and small metabolites between interconnected cells, so that gap junctions may also mediate metabolic and chemical communication. The strength of gap junctional communication between neurons and its modulation by neurotransmitters and other factors can be studied by simultaneously electrically recording from coupled cells and by determining the extent of diffusion of tracer molecules, which are gap junction permeable, but not membrane permeable, following iontophoretic injection into single cells. However, these procedures can be extremely difficult to perform on neurons with small somata in intact neural tissue.
Numerous studies on electrical synapses and the modulation of electrical communication have been conducted in the vertebrate retina, since each of the five retinal neuron types is electrically connected by gap junctions3,4. Increasing evidence has shown that the circadian (24-hour) clock in the retina and changes in light stimulation regulate gap junction coupling3-8. For example, recent work has demonstrated that the retinal circadian clock decreases gap junction coupling between rod and cone photoreceptor cells during the day by increasing dopamine D2 receptor activation, and dramatically increases rod-cone coupling at night by reducing D2 receptor activation7,8. However, not only are these studies extremely difficult to perform on neurons with small somata in intact neural retinal tissue, but it can be difficult to adequately control the illumination conditions during the electrophysiological study of single retinal neurons to avoid light-induced changes in gap junction conductance.
Here, we present a straightforward method of determining the extent of gap junction tracer coupling between retinal neurons under different illumination conditions and at different times of the day and night. This cut-loading technique is a modification of scrape loading9-12, which is based on dye loading and diffusion through open gap junction channels. Scrape loading works well in cultured cells, but not in thick slices such as intact retinas. The cut-loading technique has been used to study photoreceptor coupling in intact fish and mammalian retinas7, 8,13, and can be used to study coupling between other retinal neurons, as described here.

An easy and convenient method to determine the extent of gap junction tracer coupling between retinal neurons is described. This technique enables one to investigate the function of the electrical synapses between neurons in the intact retina under different illumination conditions and at different times of the day and night.

Cut-loading: uno strumento utile per esaminare fino di accoppiamento Tracer Junction Gap tra i neuroni della retina

In addition to chemical synaptic transmission, neurons that are connected by gap junctions can also communicate rapidly via electrical synaptic ...

Calcium Phosphate Transfection of Primary Hippocampal Neurons

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this method on hard-to-transfect cells like primary neurons. Here we describe our detailed protocol for calcium phosphate transfection of hippocampal neurons cocultured with astroglial cells.

Fosfato di calcio trasfezione di primaria neuroni dell&#39;ippocampo

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this ...

Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic effects of drugs and downstream pathways involved would help gain insight into the molecular mechanisms of neuroprotection/neurotoxicity and could potentially facilitate drug development. However, many existing in vitro toxicity assays have major limitations &#8211; most assess neurotoxicity and neuroprotection at a single time point, not allowing to observe the time-course and kinetics of the effect. Furthermore, the opportunity to collect information about downstream signaling pathways involved in neuroprotection in real-time would be of great importance. In the current protocol we describe the use of a real-time impedance-based cell analyzer to determine neuroprotective effects of serotonin 2A (5-HT2A) receptor agonists in a neuronal cell line under label-free and real-time conditions using impedance measurements. Furthermore, we demonstrate that inhibitors of second messenger pathways can be used to delineate downstream molecules involved in the neuroprotective effect. We also describe the utility of this technique to determine whether an effect on cell proliferation contributes to an observed neuroprotective effect. The system utilizes special microelectronic plates referred to as E-Plates which contain alternating gold microelectrode arrays on the bottom surface of the wells, serving as cell sensors. The impedance readout is modified by the number of adherent cells, cell viability, morphology, and adhesion. A dimensionless parameter called Cell Index is derived from the electrical impedance measurements and is used to represent the cell status. Overall, the real-time impedance-based cell analyzer allows for real-time, label-free assessment of neuroprotection and neurotoxicity, and the evaluation of second messenger pathways involvement, contributing to more detailed and high-throughput assessment of potential neuroprotective compounds in vitro, for selecting therapeutic candidates.

Improved in vitro neurotoxicity assays would aid the identification of new neuroprotective compounds. The utility of a real-time impedance-based cell analyzer to determine cytotoxicity and cytoprotection in neuronal cell lines and to delineate the involvement of second messenger pathways, thus gaining insight in the mechanism of neuroprotection is presented.

Cell Analyzer a base di impedenza in tempo reale come strumento per delineare molecolari meccanismi coinvolti nella neurotossicità e neuroprotezione in una linea cellulare neuronale

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic ...

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of the olfactory epithelium continuously give rise to new sensory neurons that extend their axons into the olfactory bulb, where they face the challenge to integrate into existing circuitry. Because of this particular feature, the olfactory system represents a unique opportunity to monitor axonal wiring and guidance, and to investigate synapse formation. Here we describe a procedure for in vivo labeling of sensory neurons and subsequent visualization of axons in the olfactory system of larvae of the amphibian Xenopus laevis. To stain sensory neurons in the olfactory organ we adopt the electroporation technique. In vivo electroporation is an established technique for delivering fluorophore-coupled dextrans or other macromolecules into living cells. Stained sensory neurons and their axonal processes can then be monitored in the living animal either using confocal laser-scanning or multiphoton microscopy. By reducing the number of labeled cells to few or single cells per animal, single axons can be tracked into the olfactory bulb and their morphological changes can be monitored over weeks by conducting series of in vivo time lapse imaging experiments. While the described protocol exemplifies the labeling and monitoring of olfactory sensory neurons, it can also be adopted to other cell types within the olfactory and other systems.

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

We describe a protocol for in vivo labeling of olfactory sensory neurons by electroporation and subsequent confocal laser-scanning or multiphoton microscopy to visualize neuronal morphology and its development over time.

Il sistema olfattivo come modello per studiare gli schemi di crescita assonale e Morfologia<em&gt; In Vivo</em

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of ...

Intramuscular Injections Along the Motor End Plates: A Minimally Invasive Approach to Shuttle Tracers Directly into Motor Neurons

Diseases affecting the integrity of spinal cord motor neurons are amongst the most debilitating neurological conditions. Over the last decades, the development of several animal models of these neuromuscular disorders has provided the scientific community with different therapeutic scenarios aimed at delaying or reversing the progression of these conditions. By taking advantage of the retrograde machinery of neurons, one of these approaches has been to target skeletal muscles in order to shuttle therapeutic genes into corresponding spinal cord motor neurons. Although once promising, the success of such gene delivery approach has been hampered by the sub-optimal number of transduced motor neurons it has so far shown to yield. Motor end plates (MEPs) are highly specialized regions on the skeletal musculature that are in direct synaptic contact to the spinal cord &#945; motor neurons. In this regard, it is important to note that, so far, the efforts to retrogradely transfer genes into motor neurons were made without reference to the location of the MEP region in the targeted muscles. Here, we describe a simple protocol 1) to reveal the exact location of the MEPs on the surface of skeletal muscles and 2) to use this information to guide the intramuscular delivery and subsequent optimal retrograde transport of retrograde tracers into motor neurons. We hope to utilize the results from these tracing experiments in further studies into investigating retrograde transport of therapeutic genes to spinal cord motor neurons through the targeting of MEPs.

The efficacy of intramuscular uptake and retrograde transport of molecules to corresponding motor neurons depends on the location of the injection sites with respect to the motor end plates (MEPs). Here, we describe how to locate MEPs on skeletal muscles to optimise retrograde transport of tracers into motor neurons.

Iniezioni intramuscolari Lungo le piastre Motor finale: un approccio mini-invasivo di navetta Tracers Direttamente nella Motor Neurons

Diseases affecting the integrity of spinal cord motor neurons are amongst the most debilitating neurological conditions. Over the last decades, the ...

Stripe Assay to Study the Attractive or Repulsive Activity of a Protein Substrate Using Dissociated Hippocampal Neurons

Growing axons develop a highly motile structure at their tip, termed the growth cone. The growth cone contacts extracellular environmental cues to navigate axonal growth. Netrin, slit, semaphorin, and ephrins are known guidance molecules that can attract or repel axons upon binding to receptors and co-receptors on the axon. The activated receptors initiate various signaling molecules in the growth cone that alter the structure and movement of the neuron. Here, we describe the detailed protocol for a stripe assay to assess the ability of a guidance molecule to attract or repel neurons. In this method, dissociated hippocampal neurons from E15.5 mice are cultured on laminin-coated dishes processed with alternating stripes of ectodomain of fibronectin and leucine-rich transmembrane protein-2 (FLRT2) and control immunoglobulin G (IgG) fragment crystallizable region (Fc) protein. Both axons and cell bodies were strongly repelled from the FLRT2-coated stripe regions after 24 h of culture. Immunostaining with tau1 showed that ~90% of the neurons were distributed on the Fc-coated stripes compared to the FLRT2-Fc-coated stripes (~10%). This result indicates that FLRT2 has a strong repulsive effect on these neurons. This powerful method is applicable not only for primary cultured neurons but also for a variety of other cells, such as neuroblasts.

Axon guidance molecules regulate neuronal migration and targeted growth-cone navigation. We present a powerful method, the stripe assay, to assess the ability of guidance molecules to attract or repulse neurons. In this protocol, we demonstrate the stripe assay by showing FLRT2's ability to repel cultured hippocampal neurons.

Stripe Assay per studiare l&#39;attività attrattiva o repulsiva di un substrato proteico Utilizzando dissociata neuroni dell&#39;ippocampo

Growing axons develop a highly motile structure at their tip, termed the growth cone. The growth cone contacts extracellular environmental cues to ...

Organotypic Hippocampal Slice Cultures As a Model to Study Neuroprotection and Invasiveness of Tumor Cells

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. This model is suitable for addressing different research questions that involve studies on neuroprotection, electrophysiological experiments on neurons, neuronal networks or tumor invasion. The hippocampal architecture and neuronal activity in multisynaptic circuits are well conserved in OHSC, even though the slicing procedure itself initially lesions and leads to formation of a glial scar. The scar formation alters presumably the mechanical properties and diffusive behavior of small molecules, etc. Slices allow the monitoring of time dependent processes after brain injury without animal surgery, and studies on interactions between various brain-derived cell types, namely astrocytes, microglia and neurons under both physiological and pathological conditions. An ambivalent aspect of this model is the absence of blood flow and immune blood cells. During the progression of the neuronal injury, migrating immune cells from the blood play an important role. As those cells are missing in slices, the intrinsic processes in the culture may be observed without external interference. Moreover, in OHSC the composition of the medium-external environment is precisely controlled. A further advantage of this method is the lower number of sacrificed animals compared to standard preparations. Several OHSC can be obtained from one animal making simultaneous studies with multiple treatments in one animal possible. For these reasons, OHSC are well suited to analyze the effects of new protective therapeutics after tissue damage or during tumor invasion. 
The protocol presented here describes a preparation method of OHSC that allows generating highly reproducible, well preserved slices that can be used for a variety of experimental research, like neuroprotection or tumor invasion studies.

Organotypic hippocampal slice cultures (OHSC) represent an in vitro model that simulates the in vivo situation very well. Here we describe a vibratome-based improved slicing protocol to obtain high quality slices for use in assessing the neuroprotective potential of novel substances or the biological behavior of tumor cells.

Colture Hippocampal Fetta organotipiche come modello di studio Neuroprotection e l'invasività delle cellule del tumore

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. ...

Exogenous Administration of Microsomes-associated Alpha-synuclein Aggregates to Primary Neurons As a Powerful Cell Model of Fibrils Formation

For years, the inability of replicating formation of insoluble alpha-synuclein (&#945;S) inclusions in cell cultures has been a great limitation in the study of &#945;S aggregation in Parkinson&#39;s Disease (PD). Recently, the development of new animal models through the exogenous inoculation of brain extracts from diseased &#945;S transgenic mice or PD patients has given new hopes to the possibility of creating more adequate cell models of &#945;S aggregation. Unfortunately, when it comes to cells in cultures, administration of raw brain extracts has not proven as successful as in mice and the source of choice of exogenous aggregates is still in vitro preformed &#945;S fibrils.
We have developed a method to induce the formation of intracellular &#945;S inclusions in primary neurons through the exogenous administration of native microsomes-associated &#945;S aggregates, a highly toxic &#945;S species isolated from diseased areas of transgenic mice. This fraction of &#945;S aggregates that is associated with the microsomes vesicles, is efficiently internalized and induces the formation of intracellular inclusions positive for aggregated and phosphorylated &#945;S. Compared to in vitro-preformed fibrils which are made from recombinant &#945;S, our method is faster and guarantees that the pathogenic seeding is made with authentic &#945;S aggregates extracted from diseased animal models of PD, mimicking more closely the type of inclusions obtained in vivo. As a result, availability of tissues rich in &#945;S inclusions is mandatory.
We believe that this method will provide a versatile cell-based model to study the microscopic aspects of &#945;S aggregation and the related cellular pathophysiology in vivo and will be a starting point for the creation of more accurate and sophisticated cell paradigm of PD.

The goal of this protocol is to provide a cell-based system that replicates the formation of alpha-synuclein aggregates in vivo. Intracellular alpha-synuclein inclusions are seeded in primary neurons by the internalization and propagation of exogenous administered native microsomes-associated alpha-synuclein aggregates isolated from diseased alpha-synuclein transgenic mice.

Somministrazione esogena di microsomi-collegato dell'alfa-synuclein aggregati di neuroni primari come un modello potente delle cellule di formazione di fibrille

For years, the inability of replicating formation of insoluble alpha-synuclein (&#945;S) inclusions in cell cultures has been a great limitation in the ...

Cell-based Assay to Study Antibody-mediated Tau Clearance by Microglia

Alzheimer&#39;s disease (AD) is a progressive neurodegenerative condition in which aggregated tau and amyloid proteins accumulate in the brain causing neuronal dysfunction which eventually leads to cognitive decline. Hyperphosphorylated tau aggregates in the neuron are believed to cause most of the pathology associated with AD. These aggregates are assumed to be released into the extracellular compartment and taken up by adjacent healthy neurons where they induce further tau aggregation. This &#34;prion-like&#34; spreading can be interrupted by antibodies capable of binding and &#34;neutralizing&#34; extracellular tau aggregates as shown in preclinical mouse models of AD. One of the proposed mechanisms by which therapeutic antibodies reduce pathology is antibody-mediated uptake and clearance of pathological aggregated forms of tau by microglia. Here, we describe a quantitative cell-based assay to assess tau uptake by microglia. This assay uses the mouse microglial cell line BV-2, allows for high specificity, low variability and medium throughput. Data generated with this assay can contribute to a better characterization of anti-tau antibody effector functions.

Here we describe a cell-based assay to quantitatively assess tau uptake by microglia with the aim of creating an investigational tool to better characterize the mechanisms of action of anti-tau antibodies.

Cell-based test per studiare la Clearance di Tau anticorpo-mediato da Microglia

Alzheimer&#39;s disease (AD) is a progressive neurodegenerative condition in which aggregated tau and amyloid proteins accumulate in the brain causing ...