TY  - JOUR
A1  - Hill, Philip J.
A1  - Stritzker, Jochen
A1  - Scadeng, Miriam
A1  - Geissinger, Ulrike
A1  - Haddad, Daniel
A1  - Basse-Lüsebrink, Thomas C.
A1  - Gbureck, Uwe
A1  - Jakob, Peter
A1  - Szalay, Aladar A.
T1  - Magnetic Resonance Imaging of Tumors Colonized with Bacterial Ferritin-Expressing \(Escherichia\) \(coli\)
JF  - PLoS ONE
N2  - Background: 

Recent studies have shown that human ferritin can be used as a reporter of gene expression for magnetic resonance imaging (MRI). Bacteria also encode three classes of ferritin-type molecules with iron accumulation properties. 

Methods and Findings: 

Here, we investigated whether these bacterial ferritins can also be used as MRI reporter genes and which of the bacterial ferritins is the most suitable reporter. Bacterial ferritins were overexpressed in probiotic E. coli Nissle 1917. Cultures of these bacteria were analyzed and those generating highest MRI contrast were further investigated in tumor bearing mice. Among members of three classes of bacterial ferritin tested, bacterioferritin showed the most promise as a reporter gene. Although all three proteins accumulated similar amounts of iron when overexpressed individually, bacterioferritin showed the highest contrast change. By site-directed mutagenesis we also show that the heme iron, a unique part of the bacterioferritin molecule, is not critical for MRI contrast change. Tumor-specific induction of bacterioferritin-expression in colonized tumors resulted in contrast changes within the bacteria-colonized tumors.

Conclusions: 

Our data suggest that colonization and gene expression by live vectors expressing bacterioferritin can be monitored by MRI due to contrast changes.
KW  - Blood-brain barrier
KW  - Gene-expression
KW  - Salmonella-typhimurium
KW  - Sugar-transport
KW  - Breast-tumors
KW  - MRI reporter
KW  - Iron-uptake
KW  - Proteins
KW  - Therapy
KW  - Mice
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-140920
VL  - 6
IS  - 10
ER  - 
TY  - JOUR
A1  - Heinsen, Helmut
A1  - Heinsen, Y. L.
T1  - Cerebellar capillaries: qualitative and quantitative observations in young and senile rats
N2  - Ultrastructural changes including reduced electron density, reduction in polysemes and cisternae of rough endoplasmic reticulum occur in the cytoplasrn of endothelial cells and pericytes in the cerebellar cortex of senile virgin female Han: WIST-rats in cornparison to 3-month old virgin rats. Processes of pericytes cover less of the capillary surface in the cerebellar cortex of senile rats; moreover, arithmetic and harmonic mean thickness of the endothelium and relative volume of mitochondria in endothelial cells and pericytes are reduced, w hereas the luminal diameter of the capillaries, harmonic and arithmetic mean thickness of pericytes and their processes and of the basal laminae between endothelial cells and astrocytes (abbreviated BAL 1), pericytes and astrocytes (BAL 2) and endothelial cells and pericytes (BAL 3) increase. The increase in harmonic mean thickness of the basal laminae is statistically significant (α<=0.05) and compensates for a decrease in thickness of capillary endothelium. Consequently, the total barrier mass and thickness of cerebellar cortical capillaries in senile animals is higher than in young individuals.
KW  - Medizin
KW  - Capillaries
KW  - Blood-brain barrier
KW  - Quantitative anatomy
KW  - Cerebellar cortex
KW  - Senile rats
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59924
ER  -