Sonja Schrepfer, Lenard Conradi e Arne Hansen ha ricevuto un finanziamento dalla Deutsche Forschungsgemeinschaft (DFG, SCHR992/3-1, SCHR992/4-1, CO 858/1-1, HA 3423/3-1). Il lavoro è stato sostenuto anche da finanziamenti dell&#39;Unione europea di Thomas Eschenhagen (EUGeneHeart e Angioscaff).

1. EHT Generation e la cultura Condizioni Fabbricazione di prodotti a base di fibrina EHT è stata eseguita come descritto altrove 4. In breve, per generare fibrina basato EHT per scopi impianto, una master mix è stato preparato contenente cellule isolate da neonatale ROSA / luciferasi-LEW cuori di ratto transgenico, fibrinogeno bovina e Matrigel. Agarosio stampi sono stati preparati con distanziali in teflon posto in ben 6 piatti della cultura. Dopo la solidificazione di agarosio, distanziatori sono stati rimossi e rastrelliere messaggio silicone sono stati messi sui piatti della cultura con messaggi raggiungendo negli stampi. Per generare EHT, il Mastermix fu brevemente mescolato con un importo calcolato della trombina e pipettati nello stampo. Dopo la polimerizzazione del fibrinogeno, rack in silicone con EHTs aderendo alla posti sono stati delicatamente rimossi dalla stampi l&#39;agarosio, trasferito al nuovo cambio a 6 e piatti di coltura cellulare e mantenuto a 37 ° C, 7% di CO 2 colture cellulari incubatore usando su misura terreno di coltura delle cellule. EHT sono stati tenuti in condizioni di coltura delle cellule fino a dieci giorni. Durante questo lasso di tempo, neonatale cellule del cuore di ratto cominciò a forma allungata, di interconnessione e allineare lungo linee di forza tra i messaggi di silicone. Al momento dell&#39;impianto, spontanea coerente contrazioni sono state osservate, deviando i messaggi di silicone. 2. EHT impianto EHT impianto è stato eseguito in entrambi i immunocompetenti Brown Norway (BN), ratti o topi immunodeficienti nudo per studiare la risposta immunitaria allogenico. Ratti BN e nudo peso di 100 - 150 g sono stati acquistati dalla Charles River Germania (Sandhofer Weg 7, D-97633 Sulzfeld) e alloggiati in condizioni convenzionali, alimentati standard di ratto chow e libidum ad acqua. Topi immunodeficienti sono ospitati, in camera sterile, gabbie, e viene utilizzata acqua sterilizzata. Il comitato etico tedesco ha esaminato e approvato le procedure animali. Tutti gli strumenti chirurgici vengono sterilizzati prima dell&#39;uso. La procedura di impianto vengono effettuate come segue: Rat sono anesthesized con isoflurano (2,5-3%) con una camera di induzione. L&#39;esposizione umana a isoflurano può essere ridotto di lavoro in una tabella rovesciati o non ricircolo cappuccio. La temperatura corporea è mantenuta durante la procedura chirurgica. <ol><li> Shave zona addominale e applicare una pomata oculare per evitare che gli occhi si secchi durante l&#39;anestesia. </li><li> Posizionare il topo sul dorso e posto una maschera sul suo naso e la bocca per mantenere l&#39;anestesia. </li><li> Disinfettare la zona addominale con Betadine e poi a 80% di etanolo. Tampone pulito da sporcare, dal centro dell&#39;area rasata in movimento verso l&#39;esterno verso l&#39;area dai capelli. </li><li> Controllare riflessi pizzicare i piedi posteriori per essere sicuri che il topo è sufficientemente anestetizzati. </li><li> Drape l&#39;animale ed effettuare una incisione addominale mediana che separa la pelle ei muscoli in due fasi per aprire l&#39;addome. Sterilizzazione a caldo tallone viene utilizzato tra la pelle e l&#39;apertura del muscolo. </li><li> Posto l&#39;intestino in un guanto salina riscaldata idratata in polvere libera. Piegare il guanto intorno l&#39;intestino per prevenire la perdita di umidità. </li><li> Rimuovere il tessuto adiposo ed esporre la milza. </li><li> Visualizzare e maggiore diffusione omento con una pinza. </li><li> Accuratamente tagliato EHT di sospendere i messaggi in silicone e di trasferimento nel omento maggiore. </li><li> Avvolgere maggiore è la omentus intorno al EHT e fissare con due singoli 7-0 suture prolene (Ethicon, Norderstedt) </li><li> Avanti spostare l&#39;intestino nuovamente dentro l&#39;addome. </li><li> Lavare l&#39;addome preriscaldata con soluzione salina sterile. </li><li> Chiudere lo strato muscolare della parete addominale con suture 6-0 prolene esecuzione (Ethicon, Norderstedt, Germania). </li><li> Utilizzare 5-0 prolene (Ethicon, Norderstedt) in esecuzione suture per chiudere la pelle. </li><li> Mentre il topo è ancora in anestesia, iniettare 5 mg / kg per via sottocutanea Carprofen. </li><li> Per fornire l&#39;analgesia sufficiente per questo tipo di procedura, un analgesico (come Metamizol) viene aggiunto all&#39;acqua potabile (50 mg Metamizol per 100 ml) per farmaci antidolorifici per 3 giorni post-trapianto. </li></ol> 3. Imaging bioluminescenza di EHT impianto seguito La piattaforma di bioimmagini IVIS (Xenogen, Alameda, CA, USA) è usato per imaging non invasiva bioluminescenza in vivo ei risultati sono analizzati utilizzando l&#39;immagine vivente IVIS (Xenogen), pacchetto software. Imaging viene effettuata ogni giorno dalle 2 ore dopo l&#39;intervento. Anestetizzare ratto con isoflurano (2,5 - 3%) con una camera di induzione. <ol><li> Disinfettare la zona addominale e toracica utilizzando ampiamente Provo-Iodio, utilizzare prossimi 80% di etanolo, ripetere questa operazione tre volte. </li><li> Iniettare d-Luciferin (Xenogen; 375 mg / kg di peso corporeo) ip </li><li> Luogo in topi anestetizzati l&#39;imaging IVIS camera (fino a 4 ratti possono essere analizzati allo stesso tempo). </li><li> Valutare l&#39;intensità del segnale di luc + cellule all&#39;interno EHT in unità di fotoni / sec / cm 2 / steridianin la regione di interesse (ROI) al basale (120 minuti dopo l&#39;impianto) e nei giorni 1, 2, 3, 5, 7, 10, e alle settimane 2, 3 e 4. Si noti il ​​picco del segnale (sembra circa 20 minuti dopo il d-Luciferin iniezione). </li></ol> Creare un grafico (Excel) che mostra l&#39;intensità del segnale nel tempo. 4. Correlazione dei risultati BLI e ELISPOT Le risposte immunitarie cellulari in-vivo in BN immunocompetenti e immunodeficienti topi nudi sono stati studiati dopo EHT trapianto. La milza di animali destinatario è stato raccolto 5 giorni dopo il trapianto EHT di isolare splenociti destinatario. ELISPOT con mitomicina-inibito EHTs (Sigma Aldrich, St. Louis, MO, USA) come stimolatore e 5 x10 6 splenociti destinatario come cellule responder sono stati eseguiti secondo il protocollo del produttore (BD Biosciences) con IFN-γ e IL-4 rivestiti piastre di indagare TH1-, e la risposta TH2, rispettivamente. IFN-γ e IL-4 punti erano significativamente più alti nel immunocompetenti, modello rispetto al modello immunodeficienti (IFN-γ: p = 0,001; IL-4: p = 0,023; Student t-test). 5. Rappresentante dei risultati: <img src="/files/ftp_upload/2605/2605fig1.jpg" alt="Figura 1" /> Figura 1. Correlazione dei risultati BLI e ELISPOT a) Il cellulare in vivo delle risposte immunitarie in immunocompetenti Brown Norvegia e topi immunodeficienti nudi sono stati studiati dopo l&#39;impianto EHT. Splenociti destinatario sono state raccolte 5 giorni dopo l&#39;impianto EHT. IFN? e IL-4 l&#39;espressione è stata valutata mediante ELISPOT mitomicina inibito EHT come stimolatori e 5x106 splenociti destinatario come cellule responder. Risposte Th1 e Th2 sono risultati significativamente più elevati nel modello immunocompetenti rispetto al modello immunodeficienti come evidenziato da IFNγ e IL-4 produzione rispettivamente. b) Luc EHTs + sono state trapiantate in maggiore è la omentus delle due ratti BN immunocompetenti o immunodeficienti topi nudi. Sopravvivenza delle cellule in senso longitudinale è stata seguita da BLI. La percentuale di animali che ha respinto il EHTs trapiantato è presentato. Tutti i ratti BN rapidamente respinto l&#39;trapianti EHT, mentre le cellule sopravvissute nei topi cellule T carente.

<ol>
	<li>Eschenhagen, T., Zimmermann, 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=Engineering+myocardial+tissue.">Engineering myocardial tissue.</a> Circ Res. 97, 1220-1231 (2005).</li><li>van der Bogt, K. E., Schrepfer, S., Yu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+transplantation+of+adipose+tissue-+and+bone+marrow-derived+mesenchymal+stem+cells+in+the+infarcted+heart.">Comparison of transplantation of adipose tissue- and bone marrow-derived mesenchymal stem cells in the infarcted heart.</a> Transplantation. 87, 642-652 (2009).</li><li>Hakamata, Y., Murakami, T., Kobayashi, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term="Firefly+rats"+as+an+organ/cellular+source+for+long-term+in+vivo+bioluminescent+imaging.">"Firefly rats" as an organ/cellular source for long-term in vivo bioluminescent imaging.</a> Transplantation. 81, 1179-1184 (2006).</li><li>Hansen, A., Eder, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+Drug+Screening+Platform+Based+on+Engineered+Heart+Tissue.">Development of a Drug Screening Platform Based on Engineered Heart Tissue.</a> Circ Res. , (2010).</li></ol>

Nessun conflitto di interessi dichiarati.

Prima applicazione clinica della tecnologia EHT per la riparazione cardiaca, questioni fondamentali come l&#39;immunogenicità di entrambi i componenti cellulari e la matrice o la sopravvivenza del trapianto dopo l&#39;impianto devono essere valutati in modelli sperimentali. In-vivo di imaging bioluminescenza rappresenta una tecnica nuova e utile per la sopravvivenza delle cellule di monitoraggio dopo il trapianto . Siamo riusciti a base di fibrina generato EHT contenente luciferasi positivo (luc +) le cellule ...

<ul><li> LEW-Tg (Gt (ROSA) 26Sor-luc) 11Jmsk ratti (numero ratto NBPR 0299, http://www.anim.med.kyoto-u.ac.jp/NBR/) </li><li> Fibrinogeno bovina (soluzione madre: 200 mg / ml aprotinina, più 5 mcg / ml fibrinogeno in NaCl 0,9%, Sigma F4753) </li><li> Matrigel (BD Bioscience 356235) </li><li> DMEM (Biochrome F0415) </li><li> Siero di cavallo (Gibco 26050) </li><li> Penicillina / streptomicina (Gibco 15140) </li><li> Insulina (Sigma-Aldrich I9278) </li><li> Aprotinina (Sigma Aldrich A1153) </li><li> d-Luciferin (Biosynth L-8220) </li><li> Enzyme-linked immunosorbent spot (ELISpot) piastre di test (Hassa Laborbedarf, S2EM004M99) </li></ul>

bioluminescence imaging for assessment of immune responses following implantation of engineered heart tissue (eht)

Varie tecniche di ingegneria tissutale cardiaco sono stati perseguiti negli ultimi decenni anche le strategie di impalcature utilizzando nativi o bioartificiale materiali patibolo, intrappolamento dei miociti cardiaci in idrogel come la fibrina o collagene e di sovrapposizione dei monostrati miociti 1. Questi concetti mirano al recupero della compromissione della funzione cardiaca (ad esempio dopo infarto miocardico) o come modelli sperimentali (es. tossicologia predittiva e screening sostanza o modelli di malattia). Monitoraggio preciso della sopravvivenza cellulare dopo l&#39;impianto del tessuto cardiaco ingegnerizzati (EHT) è ora diventato possibile usare in vivo bioluminescenza imaging (BLI) Tecniche 2. Qui si descrive la generazione di fibrina a base di EHT da un ceppo di topo transgenico con espressione ubiquitaria luciferasi di lucciola (ROSA / luciferasi-LEW Tg, 3). L&#39;impianto viene eseguito nel omento maggiore di ceppi di topo diversi per valutare le risposte immunitarie dell&#39;organismo ricevente dopo l&#39;impianto EHT. Confronto dei risultati generati dal BLI e la Enzyme Linked Immuno Tecnica Spot (ELISPOT) confermano l&#39;utilizzabilità del BLI per la valutazione delle risposte immunitarie.

Watch this Scientific Journal Video about Bioluminescence Imaging for Assessment of Immune Responses Following Implantation of Engineered Heart Tissue EHT at JoVE.com

Bioluminescence Imaging for Assessment of Immune Responses Following Implantation of Engineered Heart Tissue EHT

Questo video dimostra l&#39;uso di<em&gt; In vivo</em&gt; Immagini bioluminescenza per studiare le risposte immunitarie dopo l&#39;impianto di tessuto cardiaco Composti (EHT) nei ratti.

Imaging bioluminescenza per la valutazione delle risposte immunitarie A seguito di impianto di tessuto cardiaco Composti (EHT)

Various techniques of cardiac tissue engineering have been pursued in the past decades including scaffolding strategies using either native or ...

bioluminescence-imaging-for-assessment-immune-responses-following

Research

JoVE Journal

Bioengineering

Bioluminescence Imaging for Assessment of Immune Responses Following Implantation of Engineered Heart Tissue (EHT)

9.6K Views.  University Heart Center Hamburg. Questo video dimostra l'uso di In vivo Immagini bioluminescenza per studiare le risposte immunitarie dopo l'impianto di tessuto cardiaco Composti (EHT) nei ratti.

Video: Bioluminescence Imaging for Assessment of Immune Responses Following Implantation of Engineered Heart Tissue EHT

Establishing Intracranial Brain Tumor Xenografts With Subsequent Analysis of Tumor Growth and Response to Therapy using Bioluminescence Imaging

Transplantation models using human brain tumor cells have served an essential function in neuro-oncology research for many years. In the past, the most commonly used procedure for human tumor xenograft establishment consisted of the collection of cells from culture flasks, followed by the subcutaneous injection of the collected cells in immunocompromised mice. Whereas this approach still sees frequent use in many laboratories, there has been a significant shift in emphasis over the past decade towards orthotopic xenograft establishment, which, in the instance of brain tumors, requires tumor cell injection into appropriate neuroanatomical structures. Because intracranial xenograft establishment eliminates the ability to monitor tumor growth through direct measurement, such as by use of calipers, the shift in emphasis towards orthotopic brain tumor xenograft models has necessitated the utilization of non-invasive imaging for assessing tumor burden in host animals. Of the currently available imaging methods, bioluminescence monitoring is generally considered to offer the best combination of sensitivity, expediency, and cost. Here, we will demonstrate procedures for orthotopic brain tumor establishment, and for monitoring tumor growth and response to treatment when testing experimental therapies.

Luciferase-modified human brain tumor xenografts can be established intracranially in athymic mice, with subsequent monitoring of tumor growth and response to therapy using bioluminescence imaging. In combination with survival analysis, bioluminescence monitoring is an essential research tool for pre-clinical testing of therapies being considered for treating brain tumors.

Stabilire intracranica xenotrapianti Brain Tumor Con successiva analisi della crescita tumorale e risposta alla terapia con Imaging bioluminescenza

Transplantation models using human brain tumor cells have served an essential function in neuro-oncology research for many years. In the past, the most ...

Ricerca

Neuroscienze

Monitoring Tumor Metastases and Osteolytic Lesions with Bioluminescence and Micro CT Imaging

Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence imaging using IVIS Spectrum was employed to monitor the distribution and development of the tumor cells following the delivery procedure including DLIT reconstruction to measure the tumor signal and its location.
Development of metastatic lesions to the bone tissues triggers osteolytic activity and lesions to tibia and femur were evaluated longitudinally using micro CT. Imaging was performed using a Quantum FX micro CT system with fast imaging and low X-ray dose. The low radiation dose allows multiple imaging sessions to be performed with a cumulative X-ray dosage far below LD50. A mouse imaging shuttle device was used to sequentially image the mice with both IVIS Spectrum and Quantum FX achieving accurate animal positioning in both the bioluminescence and CT images. The optical and CT data sets were co-registered in 3-dimentions using the Living Image 4.1 software. This multi-mode approach allows close monitoring of tumor growth and development simultaneously with osteolytic activity.

An experimental mouse model of bone metastasis was established following intracardiac delivery of luciferase expressing mammary tumor cells. Tumor development and resulted osteolytic lesion were monitored longitudinally with bioluminescence and micro CT imaging.

Monitoraggio metastasi tumorali e lesioni osteolitiche con bioluminescenza e Micro CT Imaging

Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence ...

Medicina

A Cre-Lox P Recombination Approach for the Detection of Cell Fusion In Vivo

The ability of two or more cells of the same type to fuse has been utilized in metazoans throughout evolution to form many complex organs, including skeletal muscle, bone and placenta. Contemporary studies demonstrate fusion of cells of the same type confers enhanced function. For example, when the trophoblast cells of the placenta fuse to form the syncytiotrophoblast, the syncytiotrophoblast is better able to transport nutrients and hormones across the maternal-fetal barrier than unfused trophoblasts1-4. More recent studies demonstrate fusion of cells of different types can direct cell fate. The "reversion" or modification of cell fate by fusion was once thought to be limited to cell culture systems. But the advent of stem cell transplantation led to the discovery by us and others that stem cells can fuse with somatic cells in vivo and that fusion facilitates stem cell differentiation5-7. Thus, cell fusion is a regulated process capable of promoting cell survival and differentiation and thus could be of central importance for development, repair of tissues and even the pathogenesis of disease.
Limiting the study of cell fusion, is lack of appropriate technology to 1) accurately identify fusion products and to 2) track fusion products over time. Here we present a novel approach to address both limitations via induction of bioluminescence upon fusion (Figure 1); bioluminescence can be detected with high sensitivity in vivo8-15. We utilize a construct encoding the firefly luciferase (Photinus pyralis) gene placed adjacent to a stop codon flanked by LoxP sequences. When cells expressing this gene fuse with cells expressing the Cre recombinase protein, the LoxP sites are cleaved and the stop signal is excised allowing transcription of luciferase. Because the signal is inducible, the incidence of false-positive signals is very low. Unlike existing methods which utilize the Cre/LoxP system16, 17, we have incorporated a "living" detection signal and thereby afford for the first time the opportunity to track the kinetics of cell fusion in vivo.
To demonstrate the approach, mice ubiquitously expressing Cre recombinase served as recipients of stem cells transfected with a construct to express luciferase downstream of a floxed stop codon. Stem cells were transplanted via intramyocardial injection and after transplantation intravital image analysis was conducted to track the presence of fusion products in the heart and surrounding tissues over time. This approach could be adapted to analyze cell fusion in any tissue type at any stage of development, disease or adult tissue repair.

A Cre-Lox P Recombination Approach for the Detection of Cell Fusion In Vivo

A method to track cell fusion in living organisms over time is described. The approach utilizes Cre-LoxP recombination to induce luciferase expression upon cell fusion. The luminescent signal generated can be detected in living organisms using biophotonic imaging systems with a sensitivity of detection of &tilde;1,000 cells in peripheral tissues.

Un Cre-Lox P approccio ricombinazione per la rilevazione di fusione cellulare In Vivo</em

The ability of two or more cells of the same type to fuse has been utilized in metazoans throughout evolution to form many complex organs, including ...

Bioingegneria

Intracranial Implantation with Subsequent 3D In Vivo Bioluminescent Imaging of Murine Gliomas

The mouse glioma 261 (GL261) is recognized as an in vivo model system that recapitulates many of the features of human glioblastoma multiforme (GBM). The cell line was originally induced by intracranial injection of 3-methyl-cholantrene into a C57BL/6 syngeneic mouse strain 1; therefore, immunologically competent C57BL/6 mice can be used. While we use GL261, the following protocol can be used for the implantation and monitoring of any intracranial mouse tumor model. GL261 cells were engineered to stably express firefly luciferase (GL261-luc). We also created the brighter GL261-luc2 cell line by stable transfection of the luc2 gene expressed from the CMV promoter. C57BL/6-cBrd/cBrd/Cr mice (albino variant of C57BL/6) from the National Cancer Institute, Frederick, MD were used to eliminate the light attenuation caused by black skin and fur. With the use of albino C57BL/6 mice; in vivo imaging using the IVIS Spectrum in vivo imaging system is possible from the day of implantation (Caliper Life Sciences, Hopkinton, MA). The GL261-luc and GL261-luc2 cell lines showed the same in vivo behavior as the parental GL261 cells. Some of the shared histological features present in human GBMs and this mouse model include: tumor necrosis, pseudopalisades, neovascularization, invasion, hypercellularity, and inflammation 1.
Prior to implantation animals were anesthetized by an intraperitoneal injection of ketamine (50 mg/kg), xylazine (5 mg/kg) and buprenorphine (0.05 mg/kg), placed in a stereotactic apparatus and an incision was made with a scalpel over the cranial midline. A burrhole was made 0.1mm posterior to the bregma and 2.3mm to the right of the midline. A needle was inserted to a depth of 3mm and withdrawn 0.4mm to a depth of 2.6mm. Two &mu;l of GL261-luc or GL261-luc2 cells (107 cells/ml) were infused over the course of 3 minutes. The burrhole was closed with bonewax and the incision was sutured.
Following stereotactic implantation the bioluminescent cells are detectable from the day of implantation and the tumor can be analyzed using the 3D image reconstruction feature of the IVIS Spectrum instrument. Animals receive a subcutaneous injection of 150&mu;g luciferin /kg body weight 20 min prior to imaging. Tumor burden is quantified using mean tumor bioluminescence over time. Tumor-bearing mice were observed daily to assess morbidity and were euthanized when one or more of the following symptoms are present: lethargy, failure to ambulate, hunched posture, failure to groom, anorexia resulting in &gt;10% loss of weight. Tumors were evident in all of the animals on necropsy.

Intracranial Implantation with Subsequent 3D In Vivo Bioluminescent Imaging of Murine Gliomas

Intracranial implantation of GL261 cells into C57BL/6 mice produces malignant gliomas that recapitulate many of the hallmarks of human glioblastoma multiforme. We used GL261 cells stably expressing luciferase to allow us to use in vivo imaging to follow tumor progression. The surgery and 3D in vivo imaging are demonstrated.

Impianto intracranica con 3D successivi In Vivo Bioluminescent Imaging dei gliomi Murine

The mouse glioma 261 (GL261) is recognized as an in vivo model system that recapitulates many of the features of human glioblastoma multiforme (GBM). The ...

In vitro and in vivo Bioluminescence Reporter Gene Imaging of Human Embryonic Stem Cells

The discovery of human embryonic stem cells (hESCs) has dramatically increased the tools available to medical scientists interested in regenerative medicine. However, direct injection of hESCs, and cells differentiated from hESCs, into living organisms has thus far been hampered by significant cell death, teratoma formation, and host immune rejection. Understanding the in vivo hESC behavior after transplantation requires novel imaging techniques to longitudinally monitor hESC localization, proliferation, and viability. Molecular imaging has given investigators a high-throughput, inexpensive, and sensitive means for tracking in vivo cell proliferation over days, weeks, and even months. This advancement has significantly increased the understanding of the spatio-temporal kinetics of hESC engraftment, proliferation, and teratoma-formation in living subjects.

A major advance in molecular imaging has been the extension of noninvasive reporter gene assays from molecular and cellular biology into in vivo multi-modality imaging platforms. These reporter genes, under control of engineered promoters and enhancers that take advantage of the host cell s transcriptional machinery, are introduced into cells using a variety of vector and non-vector methods. Once in the cell, reporter genes can be transcribed either constitutively or only under specific biological or cellular conditions, depending on the type of promoter used. Transcription and translation of reporter genes into bioactive proteins is then detected with sensitive, noninvasive instrumentation (e.g., CCD cameras) using signal-generating probes such as D-luciferin.

To avoid the need for excitatory light to track stem cells in vivo as is required for fluorescence imaging, bioluminescence reporter gene imaging systems require only an exogenously administered probe to induce light emission. Firefly luciferase, derived from the firefly Photinus pyralis, encodes an enzyme that catalyzes D-luciferin to the optically active metabolite, oxyluciferin. Optical activity can then be monitored with an external CCD camera. Stably transduced cells that carry the reporter construct within their chromosomal DNA will pass the reporter construct DNA to daughter cells, allowing for longitudinal monitoring of hESC survival and proliferation in vivo. Furthermore, because expression of the reporter gene product is required for signal generation, only viable parent and daughter cells will create bioluminescence signal; apoptotic or dead cells will not. 

In this video, the specific materials and methods needed for tracking stem cell proliferation and teratoma formation with bioluminescence imaging will be described.

With the growing interest in stem cell therapies, molecular imaging techniques are ideal for monitoring stem cell behavior after transplantation. Luciferase reporter genes have enabled non-invasive, repetitive assessment of cell survival, location, and proliferation in vivo. This video will demonstrate how to track hESC proliferation in a living mouse.

In vitro e in Imaging bioluminescenza gene reporter in vivo di cellule staminali embrionali umane

The discovery of human embryonic stem cells (hESCs) has dramatically increased the tools available to medical scientists interested in regenerative ...

Biologia

Bioluminescent Bacterial Imaging In Vivo

This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of bacteria in gene and cell therapy for cancer. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumors following systemic administration. Bacteria engineered to express the lux gene cassette permit BLI detection of the bacteria and concurrently tumor sites. The location and levels of bacteria within tumors over time can be readily examined, visualized in two or three dimensions. The method is applicable to a wide range of bacterial species and tumor xenograft types. This article describes the protocol for analysis of bioluminescent bacteria within subcutaneous tumor bearing mice. Visualization of commensal bacteria in the Gastrointestinal tract (GIT) by BLI is also described. This powerful, and cheap, real-time imaging strategy represents an ideal method for the study of bacteria in vivo in the context of cancer research, in particular gene therapy, and infectious disease. This video outlines the procedure for studying lux-tagged E. coli in live mice, demonstrating the spatial and temporal readout achievable utilizing BLI with the IVIS system.

Bioluminescent Bacterial Imaging In Vivo

This article describes the administration of lux-tagged bacteria to mice and subsequent in vivo analysis using IVIS bioluminescence imaging.

Bioluminescent Imaging batterica<em&gt; In Vivo</em

This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of ...

Immunologia e infezioni

Multimodal Imaging of Stem Cell Implantation in the Central Nervous System of Mice

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, both in preclinical and clinical studies. However, to date results regarding functional outcome and/or tissue regeneration following stem cell transplantation are quite diverse. Generally, a clinical benefit is observed without profound understanding of the underlying mechanism(s)1. Therefore, multiple efforts have led to the development of different molecular imaging modalities to monitor stem cell grafting with the ultimate aim to accurately evaluate survival, fate and physiology of grafted stem cells and/or their micro-environment. Changes observed in one or more parameters determined by molecular imaging might be related to the observed clinical effect. In this context, our studies focus on the combined use of bioluminescence imaging (BLI), magnetic resonance imaging (MRI) and histological analysis to evaluate stem cell grafting.
BLI is commonly used to non-invasively perform cell tracking and monitor cell survival in time following transplantation2-7, based on a biochemical reaction where cells expressing the Luciferase-reporter gene are able to emit light following interaction with its substrate (e.g. D-luciferin)8, 9. MRI on the other hand is a non-invasive technique which is clinically applicable10 and can be used to precisely locate cellular grafts with very high resolution11-15, although its sensitivity highly depends on the contrast generated after cell labeling with an MRI contrast agent. Finally, post-mortem histological analysis is the method of choice to validate research results obtained with non-invasive techniques with highest resolution and sensitivity. Moreover end-point histological analysis allows us to perform detailed phenotypic analysis of grafted cells and/or the surrounding tissue, based on the use of fluorescent reporter proteins and/or direct cell labeling with specific antibodies.
In summary, we here visually demonstrate the complementarities of BLI, MRI and histology to unravel different stem cell- and/or environment-associated characteristics following stem cell grafting in the CNS of mice. As an example, bone marrow-derived stromal cells, genetically engineered to express the enhanced Green Fluorescent Protein (eGFP) and firefly Luciferase (fLuc), and labeled with blue fluorescent micron-sized iron oxide particles (MPIOs), will be grafted in the CNS of immune-competent mice and outcome will be monitored by BLI, MRI and histology (Figure 1).

This article describes an optimized sequence of events for multimodal imaging of cellular grafts in rodent brain using: (i) in vivo bioluminescence and magnetic resonance imaging, and (ii) post mortem histological analysis. Combining these imaging modalities on a single animal allows cellular graft evaluation with high resolution, sensitivity and specificity.

Imaging multimodale impianto di cellule staminali nel sistema nervoso centrale di topi

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, ...

In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum

4T1 mouse mammary tumor cells can be implanted sub-cutaneously in nu/nu mice to form palpable tumors in 15 to 20 days. This xenograft tumor model system is valuable for the pre-clinical in vivo evaluation of putative antitumor compounds.
The 4T1 cell line has been engineered to constitutively express the firefly luciferase gene (luc2). When mice carrying 4T1-luc2 tumors are injected with Luciferin the tumors emit a visual light signal that can be monitored using a sensitive optical imaging system like the IVIS Spectrum. The photon flux from the tumor is proportional to the number of light emitting cells and the signal can be measured to monitor tumor growth and development. IVIS is calibrated to enable absolute quantitation of the bioluminescent signal and longitudinal studies can be performed over many months and over several orders of signal magnitude without compromising the quantitative result.
Tumor growth can be monitored for several days by bioluminescence before the tumor size becomes palpable or measurable by traditional physical means. This rapid monitoring can provide insight into early events in tumor development or lead to shorter experimental procedures.
Tumor cell death and necrosis due to hypoxia or drug treatment is indicated early by a reduction in the bioluminescent signal. This cell death might not be accompanied by a reduction in tumor size as measured by physical means. The ability to see early events in tumor necrosis has significant impact on the selection and development of therapeutic agents.
Quantitative imaging of tumor growth using IVIS provides precise quantitation and accelerates the experimental process to generate results.

In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum

Mammary tumor cells expressing luciferase are implanted subcutaneously in mice and visualized using optical imaging to monitor tumor growth and development non-invasively in a longitudinal study.

In vivo Bioluminescent Imaging dei tumori mammari che usano lo spettro IVIS

4T1 mouse mammary tumor cells can be implanted sub-cutaneously in nu/nu mice to form palpable tumors in 15 to 20 days. This xenograft tumor model system ...

Intra-cardiac Side-Firing Light Catheter for Monitoring Cellular Metabolism using Transmural Absorbance Spectroscopy of Perfused Mammalian Hearts

Absorbance spectroscopy of cardiac muscle provides non-destructive assessment of cytosolic and mitochondrial oxygenation via myoglobin and cytochrome absorbance respectively. In addition, numerous aspects of the mitochondrial metabolic status such as membrane potential and substrate entry can also be estimated. To perform cardiac wall transmission optical spectroscopy, a commercially available side-firing optical fiber catheter is placed in the left ventricle of the isolated perfused heart as a light source. Light passing through the heart wall is collected with an external optical fiber to perform optical spectroscopy of the heart in near real- time. The transmission approach avoids numerous surface scattering interference occurring in widely used reflection approaches. Changes in transmural absorbance spectra were deconvolved using a library of chromophore reference spectra, providing quantitative measures of all the known cardiac chromophores simultaneously. This spectral deconvolution approach eliminated intrinsic errors that may result from using common dual wavelength methods applied to overlapping absorbance spectra, as well as provided a quantitative evaluation of the goodness of fit. A custom program was designed for data acquisition and analysis, which permitted the investigator to monitor the metabolic state of the preparation during the experiment. These relatively simple additions to the standard heart perfusion system provide a unique insight into the metabolic state of the heart wall in addition to conventional measures of contraction, perfusion, and substrate/oxygen extraction.

Here we introduce a method for using an intra-ventricle optical catheter in perfused hearts to perform absorbance spectroscopy across the heart wall. The data obtained provides robust information on tissue oxygen tension as well as substrate utilization and membrane potential simultaneously with cardiac performance measures in this ubiquitous preparation.

Catetere leggero intra-cardiaco per il monitoraggio del metabolismo cellulare utilizzando la spettroscopia transmurale di riambente di cuori mammiferi perfusi

Absorbance spectroscopy of cardiac muscle provides non-destructive assessment of cytosolic and mitochondrial oxygenation via myoglobin and cytochrome ...

Autonomously Bioluminescent Mammalian Cells for Continuous and Real-time Monitoring of Cytotoxicity

Mammalian cell-based in vitro assays have been widely employed as alternatives to animal testing for toxicological studies but have been limited due to the high monetary and time costs of parallel sample preparation that are necessitated due to the destructive nature of firefly luciferase-based screening methods. This video describes the utilization of autonomously bioluminescent mammalian cells, which do not require the destructive addition of a luciferin substrate, as an inexpensive and facile method for monitoring the cytotoxic effects of a compound of interest. Mammalian cells stably expressing the full bacterial bioluminescence (luxCDABEfrp) gene cassette autonomously produce an optical signal that peaks at 490 nm without the addition of an expensive and possibly interfering luciferin substrate, excitation by an external energy source, or destruction of the sample that is traditionally performed during optical imaging procedures. This independence from external stimulation places the burden for maintaining the bioluminescent reaction solely on the cell, meaning that the resultant signal is only detected during active metabolism. This characteristic makes the lux-expressing cell line an excellent candidate for use as a biosentinel against cytotoxic effects because changes in bioluminescent production are indicative of adverse effects on cellular growth and metabolism. Similarly, the autonomous nature and lack of required sample destruction permits repeated imaging of the same sample in real-time throughout the period of toxicant exposure and can be performed across multiple samples using existing imaging equipment in an automated fashion.

Mammalian cells expressing the bacterial bioluminescence gene cassette (lux) produce light autonomously. The resulting bioluminescent dynamics upon chemical exposure have been demonstrated to reflect the treatment effects on cellular growth and metabolism, making these cells an inexpensive, continuous, real-time toxicity screening tool that can easily be adapted for high-throughput automation.

Autonomamente bioluminescenti cellule di mammifero per la continua e monitoraggio in tempo reale di citotossicità

Mammalian  cell-based in vitro assays have been  widely employed as alternatives to animal testing for toxicological studies but  have been limited due to ...

Imaging bioluminescenza per la valutazione delle risposte immunitarie A seguito di impianto di tessuto cardiaco Composti (EHT)

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