Spontaneously hypertensive rats (SHR) and normotensive rats (W) has significant changes in bone metabolism. The purpose of this study was to investigate whether, the genetic predisposition, is ...sufficient to induce changes in the osteoblast differentiation and osteogenic markers in the BMSCs or in the femoral bone. For this we use young SHR rats without hypertension, but, with genetic predisposition in compared with young W.
BMSCs were cultured in a proliferation medium (MEM) or osteogenic medium. Osteogenic differentiation was analyzed by proliferation, total protein, alkaline phosphatase, mineralization, and the mRNA expression of RUNX-2, β-cathenin, osterix, bone morphogenetic protein-2(BMP-2), osteocalcin (OCN), bone sialoprotein (BSP), collagen type I (Col I), and osteopontin (OPN).
Osteoblast differentiation in SHR BMSCs (SHRC) had an increased proliferation compared with W BMSCs (WC). After osteogenic induction, there was greater reduction in proliferation in SHR (SHROM) than in W, in the same condition (WOM). On day 7, although no significant difference in the ALP activity was observed between SHROM and WOM, poor mineralization and osteoblast differentiation was noted in SHROM. The Osterix and β-catenin are involved in the reduced osteoblast differentiation in SHROM. The decreased expression of osteoblast-associated proteins such as OCN, BSP, COL I and OPN revealed poor quality of extracellular matrix (ECM) in SHROM. In the femoral bone, the immunostaining of COL1, BALP, OPN and OCN in SHR was decreased compared with the W. TRAP-positive immunoreactions were observed in major extension in the SHR femur.
This study is the first to compare osteoblast differentiation in vitro and femoral bone from SHR and W rats. Our results demonstrated that young SHR (4weeks old), without hypertension, but with genetic predisposition, had alterations in osteoblast differentiation of BMSCs and in the femoral bone when compared with their progenitor strain, W.
Periodontal Tissue Engineering After Tooth Replantation Reichert da Silva Assunção, Luciana; Colenci, Renato; Ferreira do‐Amaral, Caril Constante ...
Journal of periodontology (1970),
20/May , Volume:
82, Issue:
5
Journal Article
Peer reviewed
Background: Blood‐derived products, platelet‐poor plasma (PPP) and platelet‐rich plasma (PRP), constitute an approach in the enhancement of tissue healing. PRP has also been used as a scaffold for ...bone marrow stem cells in tissue engineering. This study evaluates the effect of PPP, calcium chloride–activated PRP (PRP/Ca), calcium chloride– and thrombin‐activated PRP (PRP/Thr/Ca), and bone marrow mononuclear cells and PRP/Ca (BMMCs/PRP/Ca) on the healing of replanted dog teeth.
Methods: After 30 minutes of extraction, teeth were replanted with 1) no material (control); 2) PPP; 3) PRP/Ca; 4) PRP/Thr/Ca; or 5) BMMCs/PRP/Ca. Histologic, histomorphometric, and immunohistochemical analysis was assessed 120 days after replantation. Data from histomorphometric analysis were analyzed statistically (analysis of variance, Tukey; P <0.05). Quantitative immunohistochemical analysis was analyzed by Kruskal‐Wallis and Dunn post hoc test (P <0.05).
Results: Flow cytometry analysis showed 55.98% of CD34+ and 32.67% of CD90/Thy‐1 for BMMCs sample. BMMCs/PRP/Ca presented the largest areas of replacement resorption characterized by osseous ingrowth into cementum (P <0.05), with intense immunomarcation for tartrate‐resistant acid phosphatase. The PRP/Ca group also showed areas of replacement resorption with significant immunomarcation for osteopontin. PRP/Thr/Ca presented no replacement resorption. PPP showed areas of inflammatory resorption, with immunomarcation for tartrate‐resistant acid phosphatase.
Conclusions: The results suggest that platelets activated with thrombin play an important role in the healing of tissues after tooth replantation. Additional studies are necessary to test other materials, because PRP/Ca did not present an appropriate scaffold for undifferentiated cells in the treatment of avulsed teeth.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Este estudo teve como objetivo avaliar o efeito da doença periodontal (DP) induzida por ligadura nos mecanismos envolvidos na atividade osteoblástica e mineralização da matriz óssea a partir de células-tronco derivadas da medula óssea do fêmur de ratos normotensos e espontaneamente hipertensos (SHR). As linhagens (180-220 g) foram divididas em dois grupos cada: Wistar Controle WC e SHR Controle SC, Wistar com DP WDP e SHR com DP SDP. Foi realizada na área de furca a análise imunoistoquímica da expressão de receptor ativador nuclear kappa-B ligante (RANKL), osteoprotegerina (OPG), fosfatase alcalina específica do osso (BALP), osteocalcina (OC), metaloproteinases de matriz (MMP)-2, e MMP-9, e fosfatase ácida tartarato resistente (TRAP) da região de furca 15 dias após a indução da DP. Célulastronco mesenquimais derivadas da medula óssea (CTMs) foram coletadas para diferenciação osteogênica. Taxa de proliferação celular, conteúdo de proteína total e atividade específica da enzima fosfatase alcalina (FAL) foram analisadas nos dias 3, 7, 10 e 14. A mineralização da matriz foi analisada no dia 17. Os dados foram expressos como média ± erro padrão da média (EPM), analisados por one- ou two-way ANOVA, seguido pelo teste de Tukey ou Bonferroni, quando apropriado. RANKL foi fracamente expresso em ambas as linhagens, mas foi moderadamente expresso em animais SDP. OPG foi moderadamente expressa em animais sem PD, mas...
This study aimed to evaluate the effect of experimentally induced periodontitis in the mechanisms involved in osteoblastic activity and bone matrix mineralization from femoral bone marrow-derived stem cells in normotensive and hypertensive rats. Wistar and SHR rats (180–220 g) were divided into 2 groups each: Wistar control WC and SHR control SC, and Wistar with PD WPD and SHR with PD SPD groups. Immunohistochemical analysis of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), bone alkaline phosphatase (BALP), osteocalcin (OC), matrix metalloproteinase (MMP)-2, MMP-9, and tartrate-resistant acid phosphatase (TRAP) of the furcation region were assessed 15 days after PD. Bone marrow mesenchymal stem cells (MSCs) were collected and assessed for osteogenic differentiation. Proliferation rate, total protein content, and ALP activity were analyzed at 3, 7, 10, and 14 days. Mineralization of matrix was analyzed at 17 days. RANKL was weakly expressed in both strains, but was moderately expressed in SPD animals. OPG was moderately expressed in animals without PD, but strongly expressed in those with PD. The expression of BALP was higher in SPD than in WPD animals. Immunolabeling for OC was absent or weak in both strains and exhibited a tendency to increase in the presence of PD. MMP-2 expression was absent or weak in animals without PD, but it increased slightly in WPD animals. MMP-9 was moderately...
FAPESP: 10/14590-6
FAPESP: 11/06070-5
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