67 research outputs found
Cell type-specific over-expression of chromosome 21 genes in fibroblasts and fetal hearts with trisomy 21
BACKGROUND: Down syndrome (DS) is caused by trisomy 21 (+21), but the aberrations in gene expression resulting from this chromosomal aneuploidy are not yet completely understood. METHODS: We used oligonucleotide microarrays to survey mRNA expression in early- and late-passage control and +21 fibroblasts and mid-gestation fetal hearts. We supplemented this analysis with northern blotting, western blotting, real-time RT-PCR, and immunohistochemistry. RESULTS: We found chromosome 21 genes consistently over-represented among the genes over-expressed in the +21 samples. However, these sets of over-expressed genes differed across the three cell/tissue types. The chromosome 21 gene MX1 was strongly over-expressed (mean 16-fold) in senescent +21 fibroblasts, a result verified by northern and western blotting. MX1 is an interferon target gene, and its mRNA was induced by interferons present in +21 fibroblast conditioned medium, suggesting an autocrine loop for its over-expression. By immunohistochemistry the p78(MX1 )protein was induced in lesional tissue of alopecia areata, an autoimmune disorder associated with DS. We found strong over-expression of the purine biosynthesis gene GART (mean 3-fold) in fetal hearts with +21 and verified this result by northern blotting and real-time RT-PCR. CONCLUSION: Different subsets of chromosome 21 genes are over-expressed in different cell types with +21, and for some genes this over-expression is non-linear (>1.5X). Hyperactive interferon signaling is a candidate pathway for cell senescence and autoimmune disorders in DS, and abnormal purine metabolism should be investigated for a potential role in cardiac defects
Levantamento fitossociológico de plantas daninhas em áreas de produção de cana-de-açúcar
Trend in the atmospheric heat source over the central and eastern Tibetan Plateau during recent decades: Comparison of observations and reanalysis data
A copper-seamed coordination nanocapsule as a semiconductor photocatalyst for molecular oxygen activation
Hydration Shell Changes in Surfactant Aggregate Transitions Revealed by Raman-MCR Spectroscopy
A copper-seamed coordination nanocapsule as a semiconductor photocatalyst for molecular oxygen activation
Self-Assembly of a Semiconductive and Photoactive Heterobimetallic Metal-Organic Capsule
Biomimetic Silk Scaffolds with an Amorphous Structure for Soft Tissue Engineering
Fine tuning physical
cues of silk fibroin (SF) biomaterials to match specific requirements
for different soft tissues would be advantageous. Here, amorphous
SF nanofibers were used to fabricate scaffolds with better hierarchical
extracellular matrix (ECM) mimetic microstructures than previous silk
scaffolds. Kinetic control was introduced into the scaffold forming
process, resulting in the direct production of water-stable scaffolds
with tunable secondary structures and thus mechanical properties.
These biomaterials remained with amorphous structures, offering softer
properties than prior scaffolds. The fine mechanical tunability of
these systems provides a feasible way to optimize physical cues for
improved cell proliferation and enhanced neovascularization in vivo.
Multiple physical cues, such as partly ECM mimetic structures and
optimized stiffness, provided suitable microenvironments for tissue
ingrowth, suggesting the possibility of actively designing bioactive
SF biomaterials. These systems suggest a promising strategy to develop
novel SF biomaterials for soft tissue repair and regenerative medicine
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