1,721,045 research outputs found
Electromagnetic fields counteract IL-1beta activity during chondrogenesis of bovine mesenchymal stem cells
No full textIntroduction
Osteoarthritis (OA) is a common joint disease associated with articular cartilage degeneration. Cartilage damage is an irreversible process, because of the limited capacity of the adult articular chondrocytes to repair and regenerate the normal cartilage matrix architecture. To improve the therapeutic options of OA, tissue engineering based on the use of mesenchymal stem cells (MSCs) has emerged. However, the presence of inflammatory cytokines, such as interleukin-1β (IL-1β) during chondrogenesis reduces the efficacy of cartilage engineering repair procedures, by preventing chondrogenic differentiation. Previous studies have shown that pulsed electromagnetic fields (PEMFs) stimulate anabolic processes in OA cartilage and limit IL-1β catabolic effects. We investigated the role of PEMFs during chondrogenic differentiation of MSCs, isolated from bovine synovial fluid, in the absence and in the presence of IL-1β.
Materials and Methods
Pellets of MSCs were differentiated for 3 and 5 weeks with transforming growth factor-β3 (TGF-β3), in the absence and in the presence of IL-1β and exposed or unexposed to PEMFs. Proteoglycans (PGs) synthesis and PG content were measured by radioactive 35S-sulphate incorporation and dimethylmethylene blue assay, respectively. Real-time RT-PCR was performed to analyze type II collagen and aggrecan expression. Histological analysis for haematoxylin and eosin and for alcian blue and immunohistochemistry for type II collagen and aggrecan were carried out on pellet sections. For statistical analysis, comparisons between groups were performed using Student’s T test and p<0.05 level was considered significant.
Results
Biochemical, quantitative real-time RT-PCR and histological results showed that PEMFs alone or in the presence of TGF-β3, play a limited role in promoting chondrogenic differentiation.
Notably, in the presence of IL-1β and TGF-β3 a recovery on PG synthesis, PG content, aggrecan and type II collagen mRNA expression in the PEMF-exposed compared to unexposed pellets was observed. Also, in the same experimental conditions, histological and immunoistochemical results showed an increase in staining for alcian blue, type II collagen and aggrecan in PEMF exposed pellets.
Discussion
The presence of inflammatory cytokines, such as IL-1β in human joints, due to arthritis or trauma, may explain why existing cartilage engineering repair strategies that rely on the in situ differentiation of MSCs, fail to provide a reliably successful. Our results support the hypothesis that PEMF treatment may favor chondrogenic differentiation in inflammatory conditions.
Conclusions
This study shows a significant role of PEMFs in counteracting the IL-1β induced inhibition on chondrogenesis, suggesting a possible therapy for improving the clinical outcome of cartilage repair procedures
Implant surface activates fibroblasts: an in vitro study
No full textTitanium (Ti) is that the most generally used material for dental, orthopedic and maxillofacial purposes thanks to its excellent biocompatibility and mechanical properties. Several data suggest that prosthesis anchorage to bone and soft tissue are often modulated by surface characteristics. Fibroblasts are the soft tissues cells concerned in producing extracellular matrix and collagen and their tight connection to implant neck is of paramount importance in preventing peri-implant infection. The aim of this work is to grow Human Fibroblast (HFb) for seven days in wells containing (or not) dental implants. The expression levels of some adhesion and traction-resistance related genes (COL11A1, COL2A1, COL9A1, DSP, ELN, HAS1, and TFRC) were analyzed using Polymerase Chain Reaction. Our results demonstrated that several genes encoding for extracellular matrix proteins are activated so giving more insight to the comprehension of the mechanism of cell to surface adhesion
Effects of spermidine synthase inhibition on cytoskeletal organization in cultured chick embryo fibroblasts
No full textThe administration of bis-cyclohexylammonium sulphate (BCHS), an inhibitor of spermidine synthase, to cultured chick embryo fibroblasts provoked alterations in cell morphology, a marked disorganization of microfilaments and changes in microtubule network structure. In addition, the rate of microtubule reappearance, after disrupting them with colchicine, was impaired by BCHS. These responses to BCHS were prevented by spermidine addition, which thus suggests an involvement of spermidine in microtubule and microfilament organization
Exogenous spermidine modulates glycosaminoglycan accumulation and epithelial differentiation in chick embryonic skin
No full textWe have previously shown that feather formation in chick embryonic skin depends on accumulation of sulphated glycosaminoglycans in the underlying mesenchyme, and that addition of spermidine to chick embryo fibroblasts increases the extracellular sulphated glycosaminoglycans. In the present work, using histological, histochemical and biochemical procedures, we have investigated the effects on glycosaminoglycan accumulation and on epithelial differentiation of adding spermidine and bis-cyclohexylammonium sulphate, a spermidine inhibitor, to embryonic chick skin cultures. Our results demonstrate that spermidine induces an accumulation of sulphated glycosaminoglycan and an increase in feather formation, suggesting that the morphogenetic effect of spermidine may be dependent on specific glycosaminoglycan accumulation
Effects of spermidine synthase inhibition in cultured chick embryo fibroblasts
No full textThe administration of bis-cyclohexylammonium sulfate (BCHS), a spermidine synthase inhibitor, to in vitro cultures of chick embryo fibroblasts caused a decrease in cellular spermidine levels and an increase in putrescine and spermine. Cell proliferation rate and DNA synthesis were also inhibited. As protein synthesis did not change, it would seem that low levels of cellular spermidine inhibit cell growth depressing DNA synthesis
In Vitro Evaluation of Plasticizer Activity on the Growth and Metabolism of Chick Embryo Fibroblasts and on the Development of Chick Embryo Lungs
No full textAdministration of di(2-ethylhexyl) phthalate (DEHP) to primary cultures of chick embryo fibroblasts brought about a decrease in cell proliferation rate after 48 h and an inhibition of both DNA and protein synthesis measured by [3H]thymidine and [3H]leucine, respectively, after 48 h. The growth of chick embryo lung rudiments in vitro was also depressed by DEHP treatment. Lung rudiment were smaller in DEHP-treated embryos after 6 days' treatment. These results indicate that DEHP has a cytostatic effect on embryonic cells and tissues
Silica dioxide colloidal solutions is efficient in the treatment of chronic periodontitis: A case control study
No full textThe objective of this study was to compare the efficacy of supportive periodontal therapy (i.e. scaling and rooth planning, SRP) alone versus a chemical device silica dioxide (SiO2) colloidal solutions (SDCS) used in association with SRP in the treatment of chronic periodontitis in adult patients. A total of 20 patients with a diagnosis of chronic periodontitis (40 localized chronic periodontitis sites) in the age group of 35 to 55 were selected. None of these patients have previously received any surgical or non-surgical periodontal therapy and demonstrated radiographic evidence of moderate bone loss. Two non-adjacent sites in separate quadrants were selected in each patient to monitorize treatment efficacy (split mouth design). Clinical pocket depth (PD) and microbial analysis (MA) were analyzed at baseline and 15th day. SPSS program and paired simple statistic T-test were used to detect significant differences. Total bacteria loading, Tannerella Forsitia and Treponema Denticola loading were statistically reduced when SiO2 is locally delivered. SDCS gel is an adjuvant therapy which should be added to SRP in the management of moderate to severe chronic periodontitis.Sin financiación1.711 JCR (2020) Q4, 132/146 Endocrinology & Metabolism0.284 SJR (2020) Q3, 167/232 Endocrinology, Diabetes and MetabolismNo data IDR 2020UE
Polyamines and ornithine decarboxylase activity in intestinal metaplasia and dysplasia of gastric mucosa
No full textPurpose: In a rural area of Northern-Eastern Italy, where we operate, there
is a higher incidence for gastric cancer than in other sides of our country.
Epithelial dysplasia and intestinal metaplasia are considered pre-neoplastic
lesions of gastric mucosa. Polyamines (PA)—Spermine (SPM), Spermidine
(SPD), Putrescine (PUT)—as well as Ornithine decarboxylase (ODC),
their rate limiting enzyme, have been suggested to be sensitive markers of
cell proliferation because closely linked to DNA regulation, RNA, protein
synthesis and membrane stability. Thus we have determined both PA and
ODC activity in gastric epithelial metaplasia and dysplasia.
Methods: Selected informed patients were admitted to the study, during
their endoscopical follow-up, since either gastric metaplasia (n 5 10) or
dysplasia (n 5 10) had been within 6 months ascertained by means of
histological examination. Two experienced endoscopists obtained the biopsy
specimens from the appropriate sites. Ten subjects with suspected
gastric disease but unconfirmed were used as controls. From the obtained
tissues both histological pattern verification and PA-ODC assessments
were performed. Four biopsy specimens were frozen with liquid nitrogen
and stored at 280°C up to the determinations. PA (SPD, SPM, PUT) were
determined with HPLC and ODC with radiometric technique according to
Stefanelli (1986). Wilcoxon’s test has been used for statistical analysis. PA
values are expressed as nmol/g protein; ODC acitivity as pmol 14CO2/
hr/mg protein.
Results: The obtained values, expressed as means and ranges, are reported
in the table. The bold typed values are significantly different (p , 0.05) vs. the group
of patients with intestinal metaplasia; the underlined values are significantly
different (p , 0.05) vs. controls.
Conclusions: ODC activity as well as PA have been suggested to be
elevated in different gastrointestinal cancers. Our results have evidenced a
significant increase of both ODC and PA, mostly for PUT, in those patients
affected by gastric dysplasia. This pattern would confirm the key role of
such markers in biologic changes of gastric mucosa displaying the high risk
of neoplastic transformatio
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