Studies on imaging and tracking transplanted cells

December 10, 2008

Tampa, Fla. (Dec. 10, 2008) - Successfully monitoring the distribution and fate of transplanted stem cells through imaging and subsequent tracking would aid clinicians in their ability to evaluate the efficacy of transplanted cells. Three studies published in the current issue of Cell Transplantation (Vol. 17, No.8) assess various imaging techniques and evaluate the degree to which the techniques afford clinicians useable imaging and tracking data.

Bioluminescent imaging of human fetal hepatocytes

In a study conducted by Dr. Mark A. Zern and colleagues at the Transplant Research Institute, University of California Davis Medical Center, the use of bioluminescent imaging to track transplanted immortalized human fetal hepatocytes injected into mice was evaluated. According to the researchers, it was essential for them to evaluate via noninvasive monitoring the effectiveness of transplanted cells to engraft and repopulate the recipient liver. Using double or triple fusion lentiviral vectors in a mouse model transplanted with immortalized fetal hepatocytes, the researchers for the first time imaged in vivo human hepatic progenitor cells transplanted into a rodent model.

"Our results, confirmed by a series of biochemical and histologic modalities, indicate that this imaging system appears to be a promising approach for repeatedly and noninvasively monitoring transplanted hepatic cells," said Zern.

Contact: Dr. Mark A. Zern, Transplant Institute, UC Davis Medical Center, (916) 734-8063; mazern@ucdavis.edu




Using small particles of iron oxide

A second study involving imaging published in this issue of Cell Transplantation (Vol. 17 No. 8), evaluated the use of cloned mensenchymal stem cells (MSC) labeled with clinically-approved small particles of iron oxide (SPIO) for the treatment of experimental autoimmune encephalomyelitis (EAE). Results revealed an increase in disease severity when using SPIO while a control experiment with unlabeled MSC did not affect disease severity.

"Treatment with SPIO alone did not alter disease course," said study lead author Dr. Richard Schafer of the Institute of Clinical and Experimental Transfusion Medicine at University Hospital, Tubingen, Germany. "Iron deposition was present in the group treated with SPIO-labeled MSC, indicating that in vivo the initially cell surface bound iron detached from the MSC. Our results could be of great importance for imaging patients in the clinical setting, indicating that in vivo application of SPIO-labeled MSC needs to be performed with caution since the cell-derived exposure of iron can lead to disease aggravation."

Contact: Dr. Richard Schafer, University Hospital, Tubingen, Germany + 49-7071-295240 richard.schafer@med.uni-tuebingen.de




Three different labeling methods evaluated

In a study conducted at the Center for Research in Cardiovascular Medicine at the State University of New York (SUNY) Buffalo, researchers experimented with three different labeling methods for tracking transplanted mensenchymal stem cells (MSCs): adenovirus-mediated expression of enhanced green fluorescence protein (EGFP); B-galactosidase (LacZ); and live cell DAPI nuclear staining. Each was used to label porcine bone marrow-derived MSCs in cultures.

"Although MSCs could be efficiently labeled by these methods in cultures, whether the labels could be reliably detected after in vivo implantation, particularly in a large animal model, needed to be examined," said study lead author Dr. Techung Lee of the SUNY Buffalo Department of Biochemistry.

The research team experienced 'inconsistency' when attempting to track EGFP and LacZ-labeled MSCs while the DAPI-labeled cells could be 'stably retained' in the implanted MSCs for at least one month after implantation.

"These labeled MSCs could be detected histologically with little ambiguity," commented Lee.

The researchers concluded that DAPI labeling could be reliably used for MSC tracking in both small and large animal models because the brightly emitted blue fluorescence is exclusively confined to the nucleus, generating a sharper image that was advantageous for stem cell identification.

Contact: Dr. Techung Lee, SUNY Buffalo (716) 829-3106 chunglee@buffalo.edu

"The availability of in vivo monitoring of transplanted cells allows visualization of cell migration and proliferation, adding a critical parameter for safety and efficacy measure," said Cesar Borlongan, Ph.D. at the University of South Florida Health, and associate editor of Cell Transplantation.
-end-
The editorial offices for CELL TRANSPLANTATION are at the Center of Excellence for Aging and Brain Repair, College of Medicine, the University of South Florida and the Diabetes Research Institute, University of Miami Miller School of Medicine. Contact, David Eve, PhD., Associate Editor at deve@health.usf.edu .

Cell Transplantation Center of Excellence for Aging and Brain Repair

Related Iron Articles from Brightsurf:

How stony-iron meteorites form
Meteorites give us insight into the early development of the solar system.

Bouillon fortified with a new iron compound could help reduce iron deficiency
Iron fortification of food is a cost-effective method of preventing iron deficiency.

Iron nanorobots go undercover
Customizable magnetic iron nanowires pinpoint and track the movements of target cells.

Iron deficiency in corals?
When iron is limited, the microalgae that live within coral cells change how they take in other trace metals, which could have cascading effects on vital biological functions and perhaps exacerbate the effects of climate change on corals.

Blocking the iron transport could stop tuberculosis
The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply.

Observed: An exoplanet where it rains iron
Nature magazine is publishing today a surprising study about the giant, ultra-hot planet WASP-76b in which researchers from the Instituto de Astrofísica de Canarias (IAC) have taken part.

An iron-clad asteroid
Mineralogists from Jena and Japan discover a previously unknown phenomenon in soil samples from the asteroid 'Itokawa': the surface of the celestial body is covered with tiny hair-shaped iron crystals.

It's Iron, Man: ITMO scientists found a way to treat cancer with iron oxide nanoparticles
Particles previously loaded with the antitumor drug are injected in vivo and further accumulate at the tumor areas.

The brain may need iron for healthy cognitive development
Iron levels in brain tissue rise during development and are correlated with cognitive abilities, according to research in children and young adults recently published in JNeurosci.

The regulators active during iron deficiency
Iron deficiency is a critical situation for plants, which respond using specific genetic programmes.

Read More: Iron News and Iron Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.