5 research outputs found
Lubricin is expressed in chondrocytes derived from osteoarthritic cartilage encapsulated in poly (ethylene glycol) diacrylate scaffold
Osteoarthritis (OA) is characterized by degenerative changes within joints that involved quantitative and/or qualitative alterations of cartilage and synovial fluid lubricin, a mucinous glycoprotein secreted by synovial fibroblasts and chondrocytes. Modern therapeutic methods, including tissue-engineering techniques, have been used to treat mechanical damage of the articular cartilage but to date there is no specific and effective treatment. This study aimed at investigating lubricin immunohistochemical expression in cartilage explant from normal and OA patients and in cartilage constructions formed by Poly (ethylene glycol) (PEG) based hydrogels (PEG-DA) encapsulated OA chondrocytes. The expression levels of lubricin were studied by immunohistochemistry: i) in tissue explanted from OA and normal human cartilage; ii) in chondrocytes encapsulated in hydrogel PEGDA from OA and normal human cartilage. Moreover, immunocytochemical and western blot analysis were performed in monolayer cells from OA and normal cartilage. The results showed an increased expression of lubricin in explanted tissue and in monolayer cells from normal cartilage, and a decreased expression of lubricin in OA cartilage. The chondrocytes from OA cartilage after 5 weeks of culture in hydrogels (PEGDA) showed an increased expression of lubricin compared with the control cartilage. The present study demonstrated that OA chondrocytes encapsulated in PEGDA, grown in the scaffold and were able to restore lubricin biosynthesis. Thus our results suggest the possibility of applying autologous cell transplantation in conjunction with scaffold materials for repairing cartilage lesions in patients with OA to reduce at least the progression of the disease
Effects of exposure to fluoro-edenite fibre pollution on the respiratory system: an in vivo model
An increased standardised rate of mortality
from pleural mesothelioma among the population of
Biancavilla (Sicily, Italy) has been attributed to exposure
to fluoro-edenite fibres. Our aim was to establish
whether and how these fibres may induce pathological
effects using an in vivo model.
Lung tissue collected from 60 healthy sheep selected
from six flocks habitually grazing near Biancavilla and
from 10 control sheep was fixed formalin and paraffinembedded;
sections were stained with haematoxylineosin,
Masson trichrome and Gomori argentic
impregnation. Histochemical studies and
immunohistochemical analysis for the localisation of
TRAIL, DR5 and MMP13 were also performed.
The lungs of exposed sheep exhibited fibrosis and
loss of alveolar architecture with honeycombing of
alveolar cavities. Fluoro-edenite fibres were detected
close to the alveolar epithelium and interstitia. The
parenchyma showed hyaline degeneration and strong
PAS-positivity in the interstitium, proteoglycan
alterations, reflecting a damaged basal membrane and an
involvement of the interstitial matrix. MMP-13 was
overexpressed, mainly in fibroblasts and epithelial cells,
while positivity for TRAIL and DR5 was detected on alveolar surfaces and in the vascular stroma.
The initial pathological event seems to involve first
the alveoli and subsequently the interstitium, giving rise
to classic honeycombing. The triggering event at the
level of type I pneumocytes would damage the
cytoplasmic membrane resulting in loss of cell elements
and exposure of underlying capillaries, and eventually in
a series of reactions including macrophage activation,
possible release of growth factors and metaplasic
reconstruction of lung alveoli. Immunopositivity for
TRAIL and MMP-13 receptor suggests that apoptotic
processes may also be activated by fluoro-edenite
Fluoro-edenite fibres induce lung cell apoptosis, an in vivo study
We previously showed that apoptosis in the
lungs of sheep exposed to fluoro-edenite fibres is
induced via the receptor pathway. The present study was
performed to gain further insights into the mechanisms
of activation of programmed cell death induced by the
fibres.
Fluoro-edenite fibres are similar in size and
morphology to some amphibolic asbestos fibres. They
have been found in benmoreitic lavas, in the local stone
quarry, in building materials and in road paving at
Biancavilla, a town in eastern Sicily (Italy), where
epidemiological surveys revealed a cluster of mortality
from pleural mesothelioma. Inhalation of asbestos fibres
can cause chronic inflammation and carcinogenesis.
Since fluoro-edenite has been shown to activate the
apoptotic process, we set out to characterise the
expression of apoptosis-regulating proteins in fluoroedenite-
exposed lung disease and sought to determine if
apoptosis results from fluoro-edenite exposure.
Lung tissue from apparently healthy sheep habitually
grazing near Biancavilla was processed for
immunohistochemical localisation of bcl-2 and bax.
Results showed epithelial and interstitial bax
overexpression, especially in cells directly in contact
with the fibres, and negative bcl-2 immunoexpression.
TUNEL-positive cells were detected in alveoli and
connective tissue.
The integrity of alveolar epithelium and alveolar
apoptosis are critical determinants in the pathways that
initiate fibrogenesis in the lung and fibroblastic foci are
usually found close to abnormal or denuded alveolar
epithelium.
Our results are consistent with the hypothesis that
apoptosis is an important mechanism for removing cells
with irreparable fluoro-edenite-induced genetic changes
that predispose them to a neoplastic evolution
Anatomia Umana
Testo di anatomia Umana per Lauree Sanitarie e Scienze Motori