Laboratorio Of Immunoreumatologia E Rigenerazione Tissutale

Bologna, Italy

Laboratorio Of Immunoreumatologia E Rigenerazione Tissutale

Bologna, Italy
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Lambertini E.,University of Ferrara | Penolazzi L.,University of Ferrara | Morganti C.,University of Ferrara | Lisignoli G.,Laboratorio Of Immunoreumatologia E Rigenerazione Tissutale | And 8 more authors.
International Journal of Biochemistry and Cell Biology | Year: 2015

Abstract A substantial body of evidence indicates that mitochondrial morphology and function change during osteogenic differentiation. However, molecular mechanisms linking mitochondrial dynamics with the regulation of osteoblast functions are poorly understood. Amongst the molecules that influence the decision of human mesenchymal stem cells (hMSCs) to become osteoblasts are Slug and NFATc1 transcription factors (TFs). These molecules also interfere with different mitochondria-dependent pathways in response to a variety of cellular demands. The present study investigated the recruitment of Slug and NFATc1 at the D-loop regulatory region of mitochondrial DNA (mtDNA) in osteogenic differentiated hMSCs with the aim of exploring whether Slug and NFATc1 also act as mitoTFs in the mitochondrial pool of nuclear TFs. The results demonstrate that NFATc1, but not Slug, is localized in the mitochondria. Using chromatin immunoprecipitation assay, we found that NFATc1 is recruited at mtDNA, but this occurs only when the calcification process is at its highest in osteo-induced MSC and the maximum level of differentiation is reached. Occupancy of the mtDNA by NFATc1 is associated with a decreased expression of crucial mitochondrial genes such as Cytochrome B and NADH dehydrogenase 1. This suggests that NFATc1 acts as a negative regulator of mtDNA transcription during the calcification process and interruption of aerobic energy demand. The finding of NFATc1 participation in osteogenic differentiation through its direct involvement in the regulatory machinery of mitochondria suggests a new role for this TF and adds information on communication between mitochondrial and nuclear genomes. © 2015 Elsevier Ltd.

Maumus M.,French Institute of Health and Medical Research | Maumus M.,Montpellier University | Manferdini C.,Laboratorio Of Immunoreumatologia E Rigenerazione Tissutale | Manferdini C.,Laboratorio RAMSES | And 15 more authors.
Stem Cell Research | Year: 2013

Our work aimed at evaluating the role of adipose stem cells (ASC) on chondrocytes from osteoarthritic (OA) patients and identifying the mediators involved. We used primary chondrocytes, ASCs from different sources and bone marrow mesenchymal stromal cells (MSC) from OA donors. ASCs or MSCs were co-cultured with chondrocytes in a minimal medium and using cell culture inserts. Under these conditions, ASCs did not affect the proliferation of chondrocytes but significantly decreased camptothecin-induced apoptosis. Both MSCs and ASCs from different sources allowed chondrocytes in the cocultures maintaining a stable expression of markers specific for a mature phenotype, while expression of hypertrophic and fibrotic markers was decreased. A number of factors known to regulate the chondrocyte phenotype (IL-1β, IL-1RA, TNF-α) and matrix remodeling (TIMP-1 and -2, MMP-1 and -9, TSP-1) were not affected. However, a significant decrease of TGF-β1 secretion by chondrocytes and induction of HGF secretion by ASCs was observed. Addition of a neutralizing anti-HGF antibody reversed the anti-fibrotic effect of ASCs whereas hypertrophic markers were not modulated. In summary, ASCs are an interesting source of stem cells for efficiently reducing hypertrophy and dedifferentiation of chondrocytes, at least partly via the secretion of HGF. This supports the interest of using these cells in therapies for osteo-articular diseases. © 2013 Elsevier B.V.

Battistelli M.,Urbino University | Salucci S.,Urbino University | Olivotto E.,Laboratorio Of Immunoreumatologia E Rigenerazione Tissutale | Facchini A.,University of Bologna | And 10 more authors.
Apoptosis | Year: 2014

Chondrocyte death and loss of extracellular matrix are the central features in articular cartilage degeneration during osteoarthritis pathogenesis. Cartilage diseases and, in particular, osteoarthritis are widely correlated to apoptosis but, chondrocytes undergoing apoptosis "in vivo" more often display peculiar features that correspond to a distinct process of programmed cell death termed "chondroptosis". Programmed cell death of primary human chondrocyte has been here investigated in micromasses, a tridimensional culture model, that represents a convenient means for studying chondrocyte biology. Cell death has been induced by different physical or chemical apoptotic agents, such as UVB radiation, hyperthermia and staurosporine delivered at both 1 and 3 weeks maturation. Conventional electron microscopy was used to analyse morphological changes. Occurrence of DNA fragmentation and caspase involvement were also investigated. At Transmission Electron Microscopy, control cells appear rounding or slightly elongated with plurilobated nucleus and diffusely dispersed chromatin. Typically UVB radiation and staurosporine induce chromatin apoptotic features, while hyperthermia triggers the "chondroptotic" phenotype. A weak TUNEL positivity appears in control, correlated to the well known cell death patterns occurring along cartilage differentiation. UVB radiation produces a strong positivity, mostly localized at the micromass periphery. After hyperthermia a higher number of fluorescent nuclei appears, in particular at 3 weeks. Staurosporine evidences a diffuse, but reduced, positivity. Therefore, DNA fragmentation is a common pattern in dying chondrocytes, both in apoptotic and "chondroptotic" cells. Moreover, all triggers induce caspase pathway activation, even if to a different extent, suggesting a fundamental role of apoptotic features, in chondrocyte cell death. © 2014 Springer Science+Business Media New York.

Piva R.,University of Ferrara | Lambertini E.,University of Ferrara | Manferdini C.,Laboratorio Of Immunoreumatologia E Rigenerazione Tissutale | Manferdini C.,Laboratorio RAMSES | And 9 more authors.
Osteoarthritis and Cartilage | Year: 2015

To contribute to clarify molecular mechanisms supporting senescence and de-differentiation of chondrocytes in chondrocyte pathologies such as osteoarthritis (OA). Specifically, we investigated the relationship between the nuclear lamina protein Lamin B1 and the negative regulator of chondrogenesis Slug transcription factor in osteoarthritic chondrocytes. Methods: Lamin B1 and Slug proteins were analyzed in cartilage explants from normal subjects and OA patients by immunohistochemical technique. Their expression was confirmed on isolated chondrocytes both at passage 0 and passage 2 (de-differentiated chondrocytes) by immunofluorescence and western blot. Subsequently, we explored the ". in vivo" binding of Slug on LMNB1 promoter by chromatin immunoprecipitation assay (ChIP). Results: In this study we demonstrated that nuclear lamina protein Lamin B1 and anti-chondrogenic Slug transcription factor are upregulated in cartilage and OA chondrocytes. Furthermore, we found that Slug is ". in vivo" recruited by LMNB1 gene promoter mostly when chondrocytes undergo de-differentiation or OA degeneration. Conclusions: We described for the first time a potential regulatory role of Slug on the LMNB1 gene expression in OA chondrocytes. These findings may have important implications for the study of premature senescence, and degeneration of cartilage, and may contribute to develop effective therapeutic strategies against signals supporting cartilage damage in different subsets of patients. © 2015 Osteoarthritis Research Society International.

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