Digitum Colección:
http://hdl.handle.net/10201/29524
2024-03-29T01:35:01ZFibroblast remodeling of adsorbed collagen type IV is altered in contact with cancer cells
http://hdl.handle.net/10201/29709
Título: Fibroblast remodeling of adsorbed collagen type IV is altered in contact with cancer cells
Autor/es principal/es: Maneva-Radicheva, L.; Ebert, U.; Dimoudis, N.; Altankov, G.
Resumen: A series of co-culture experiments between
fibroblasts and H-460 human lung carcinoma cells were
performed to learn more about the fate of adsorbed type
IV collagen (Coll IV). Fibroblasts were able to spatially
rearrange Coll IV in a specific linear pattern, similar but
not identical to the fibronectin (FN) fibrils. Coll IV
partly co-aligns with fibroblast actin cytoskeleton and
transiently co-localize with FN, as well as with ß1 and
a2 integrin clusters, suggesting a cell-dependent
process. We further found that this Coll IV
reorganization is suppressed in contact with H460 cells.
Zymography revealed strongly elevated MMP-2 activity
in supernatants of co-cultures, but no activity when
fibroblasts or cancer cells were cultured alone. Thus, we
provide evidence that reorganization of substrate
associated Coll IV is a useful morphological approach
for in vitro studies on matrix remodeling activity during
tumorigenesis.2008-01-01T00:00:00ZLectin histochemistry for in situ profiling of rat colon sialoglycoconjugates
http://hdl.handle.net/10201/29708
Título: Lectin histochemistry for in situ profiling of rat colon sialoglycoconjugates
Autor/es principal/es: Accili, Daniela; Menghi, Giovanna; Gabrielli, M.G.
Resumen: The growing interest in glycoconjugates
expressed and released by the epithelium of the intestinal
mucosa is tightly related to the multiple functional roles
attributed to sialic acid and its derivatives. In the present
work, biotin and HRP conjugated lectins were used to
detect the sialylation pattern and to identify specific
structural features of sialoderivatives in the rat colon. In
particular, the occurrence and distribution of sialic acids
linked a2,6 to D-Gal/D-GalNAc and a2,3 to D-Gal were
directly demonstrated with SNA and MAL II binding,
respectively. In addition, in order to by-pass the
specificity problems of SNA and MAL II as
histochemical reagents, as well as to look for additional
and complementary information about acetylation
degree and sites, we combined sialidase digestion,
potassium hydroxide deacetylation, and differential
periodate oxidation with PNA and DBA binding. The
data showed the distribution and structure of sialic acidß-
D-Gal(1-3)-D-GalNAc and sialic acid-D-GalNac
sequences, which proved to be widely distributed as
cellular components or secretory products in surface
goblet cells and crypt cells of the colonic epithelium. A high degree of O-acetylation, with acetyl groups mainly
at 9 and 4 positions, was found, showing an increasing
gradient from the proximal to distal portion of the colon.
These results, which largely reproduce the sialylation
pattern in other species, contribute new insights in
defining the tissue specific expression of sialoderivatives
in the colonic mucosa, and testify to their high
heterogeneity which the wide range of sialic acid
functional correlates in the intestinal tract depend on.2008-01-01T00:00:00ZCardiac ischemia and reperfusion in spontaneously diabetic rats with and without application of EGb 761, I. cardiomyocytes
http://hdl.handle.net/10201/29707
Título: Cardiac ischemia and reperfusion in spontaneously diabetic rats with and without application of EGb 761, I. cardiomyocytes
Autor/es principal/es: Schneider, Rick; Welt, Klaus; Aust, Wolfram; Löster, Heinz; Fitzl, Günther
Resumen: Diabetic cardiomyopathy is known to result
in increased mortality after ischemic events.
Permanently increased oxidative stress with formation of
oxygen-free radicals plays a key role in the development
of specific heart muscle disease. Associated lesions
include structural alterations to cardiomyocytes.
Antioxidative treatment in addition to the usual insulin
substitution would seem sensible in preventing or
delaying long-term diabetic complications and
protecting the myocardium against acute ischemic
events. We investigated the effects of radical scavenger
Ginkgo biloba extract EGb 761 against diabetes-induced
damage to cardiomyocytes and additional ischemia/
reperfusion injury in spontaneously diabetic
BioBreeding/Ottawa Karlsburg (BB/OK) rats, as a
model of diabetic myocardium infarction. Morphological
and morphometric parameters of heart muscles were
analyzed by light and electron-microscopic techniques.
We used immunohistochemistry to evaluate parameters
of oxidative stress (superoxide dismutase [SOD]) and
inducible nitric oxide synthase (iNOS) protein
expression. Our results indicated that A) Diabetic
myocardium appears more vulnerable to ischemia/
reperfusion damage concerning ultrastructure of
cardiomyocytes (sarcomeres, vacuoles, mitochondria), expression of antioxidative enzymes (CuZnSOD,
MnSOD), and iNOS than normal myocardium; B) Pretreatment
of diabetic myocardium with EGb and
additional ischemia/reperfusion leads to a relative
improvement in myocardial ultrastructure compared to
unprotected myocardium. In summary, EGb appears to
be promising as an adjuvant therapeutic drug in diabetics
with respect to ischemic myocardium injury. It may
contribute to the prevention of late diabetic
complications in diabetic cardiomyopathy.2008-01-01T00:00:00ZDendritic cell migration and lymphocyte homing imprinting
http://hdl.handle.net/10201/29705
Título: Dendritic cell migration and lymphocyte homing imprinting
Autor/es principal/es: Villablanca, Eduardo J.; Russo, Vicenzo; Rodrigo Mora, J.
Resumen: For an effective adaptive immune response to
occur, dendritic cells (DC), which are the most efficient
antigen-presenting cells, must be able to sample the
peripheral microenvironment and migrate towards
secondary lymphoid organs (SLO) where they activate
naïve lymphocytes. Upon activation, lymphocytes
proliferate and acquire the capacity to migrate to
extralymphoid compartments. Although the molecular
mechanisms controlling lymphocyte homing to
lymphoid and to some extralymphoid tissues have been
described in significant detail, it is much less clear how
DC migration is controlled. Do DC obey similar
adhesion cues that lymphocytes do, or do they have their
own “zip codes”? This is relevant from a therapeutic
standpoint because effective DC-based vaccines should
be able to reach the appropriate tissues in order to
generate protective immune responses. Here, we discuss
some of the mechanisms used by DC to reach their target
tissues. Once DC arrive at their destination, they are
exposed to the tissue microenvironment, which likely
modulates their functional properties in a tissue-specific
fashion. This local DC “education” is probably
responsible among other things; for the acquisition of
tissue-specific homing imprinting capacity by which DC
instruct lymphocytes to migrate to specific tissues. Finally, we discuss how dysregulation of these signals
may play a key role in disease.2008-01-01T00:00:00Z