Papers by Karina Bombonato-prado

The FASEB Journal
Osteoporosis is one of the most important diseases associated with aging. The aim of this study w... more Osteoporosis is one of the most important diseases associated with aging. The aim of this study was to determine if there is a distinct expression of genes associated with osteoblast differentiation in bone marrow mesenchymal stem cells (MSCs) and calvaria osteoblastic cells (COs) of rats induced to osteoporosis through ovariectomy. Cells from bone marrow and calvaria of control and osteoporotic rats were cultured in osteogenic medium and divided into four different groups: calvaria/control (CC); calvaria/osteoporosis (CO); bone marrow/control (MC) and bone marrow/osteoporosis (MO). After 3, 7 and 10 days, real‐time RT‐PCR for key bone markers was carried out in quintuplicate (n=5) and data were compared by Kruskal‐Wallis and Mann‐Whitney tests (p<0.05). Alkaline phosphatase and runt‐related transcription factor 2 expressions were significantly increased in MO and decreased in CO in all periods. Osteocalcin expression was significantly increased in MO at 7 and 10 days, and decrea...

Brazilian Dental Journal, Nov 1, 2020
Recent studies suggest that osteoporosis, in addition to the damage caused in long bones, may cau... more Recent studies suggest that osteoporosis, in addition to the damage caused in long bones, may cause deterioration in the jaws, especially in alveolar bone sites, with effects in the progress of periodontal disease as well as in bone healing. The aim of this study was to evaluate the effect of osteoporosis in the metabolism of rat alveolar bone osteoblasts. There were used 10 female rats divided in two experimental groups (Sham and OVX), which were ovariectomized and after 8 weeks euthanized to collect mandibular bone samples in order to isolate osteoblastic cells. The cells were cultured in 24-well plates to perform the in vitro experiments. After 7, 10 and 14 days, there were evaluated cell proliferation by MTT assay, in situ detection of alkaline phosphatase (ALP) as well as mineralized nodules and expression of genes associated to bone remodeling. Results showed that at 7, 10 and 14 days cell proliferation was lower for OVX group. In situ detection of ALP was higher at 7 days and lower at 10 and 14 days in OVX group. At 17 and 21 days, OVX group had a significative decrease of mineralization nodules. There was a downregulation in the expression of Alp, Bglap and Runx2 genes and an upregulation of Opg in OVX group, whereas Opn and Rankl modulation was similar between the evaluated groups. Our results suggest that osteoporosis has a deleterious effect on alveolar bone cells from ovariectomized rats, which might affect the treatment of diseases associated to the jaw bones.

Brazilian Dental Journal, 2012
The aim of this study was to evaluate the odontogenic potential of undifferentiated pulp cells (O... more The aim of this study was to evaluate the odontogenic potential of undifferentiated pulp cells (OD-21 cell line) through chemical stimuli in vitro. Cells were divided into uninduced cells (OD-21), induced cells (OD-21 cultured in supplemented medium/OD-21+OM) and odontoblast-like cells (MDPC-23 cell line). After 3, 7, 10 and 14 days of culture, it was evaluated: proliferation and cell viability, alkaline phosphatase activity, total protein content, mineralization, immunolocalization of dentin matrix acidic phosphoprotein 1 (DMP1), alkaline phosphatase (ALP) and osteopontin (OPN) and quantification of genes ALP, OSTERIX (Osx), DMP1 and runtrelated transcription factor 2 (RUNX2) through real-time polymerase chain reaction (PCR). Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests (p<0.05). There was a decrease in cell proliferation in OD-21 + OM, whereas cell viability was similar in all groups, except at 7 days. The amount of total protein was higher in group OD-21 + OM in all periods; the same occurred with ALP activity after 10 days when compared with OD-21, with no significant differences from the MDPC-23 group. Mineralization was higher in OD-21+OM when compared with the negative control. Immunolocalization demonstrated that DMP1 and ALP were highly expressed in MDPC-23 cells and OD-21 + OM cells, whereas OPN was high in all groups. Real-time PCR revealed that DMP1 and ALP expression was higher in MDPC-23 cell cultures, whereas RUNX2 was lower for these cells and higher for OD-21 negative control. Osx expression was lower for OD-21 + OM. These results suggest that OD-21 undifferentiated pulp cells have odontogenic potential and could be used in dental tissue engineering.

Journal of Health Sciences, Mar 18, 2021
Low-level laser therapy has been investigated as a possible stimulus for enhancement of prolifera... more Low-level laser therapy has been investigated as a possible stimulus for enhancement of proliferation and differentiation of various cell types, but few reports relate undifferentiated mouse pulp cells (OD-21) response to irradiation in in vitro models. The aim of this study was to analyze the influence of low-level laser therapy (λ=660 nm), with three different irradiation times, on the behavior of OD-21 cell line. The cells were cultivated and divided into three groups: non-irradiated/control (group I); irradiated with 88 s (group II); irradiated with 177 s (group III) and irradiated with 265 s (group IV). Cell growth and viability were assessed after 7 and 10 days. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (α=.05). At day 7, there was a higher cell growth in groups I and II, as compared to group IV (p<.01). At the 10th day, group I showed a higher cell growth as compared to group II (p<.05). Cell viability in group IV was significantly lower at the 7th day, as compared to groups I (p<.001), II (p<.01) and III (p<.001). Cell viability in all the groups was over 80%, except in group IV at day 7. Irradiation time of group I influenced positively the proliferation and viability of OD-21 cells in late cell culture period.

Journal of Applied Oral Science, 2020
Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use... more Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use aiming at periapical tissue repair. However, its effects on dental pulp cells have been poorly explored. Objective: This study assessed the impact of calcium chloride (CaCl 2 ) and bismuth oxide (Bi2O 3 ) or zinc oxide (ZnO) additives on odontoblast cell response to CAC. Methodology: MDPC-23 cells were exposed for up to 14 d: 1) CAC with 2.8% CaCl2 and 25% ZnO (CACz); 2) CAC with 2.8% CaCl2 and 25% Bi 2 O3 (CACb); 3) CAC with 10% CaCl2 and 25% Bi 2 O3 (CACb+); or 4) mineral trioxide aggregate (MTA), placed on inserts. Non-exposed cultures served as control. Cell morphology, cell viability, gene expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), and dentin matrix protein 1 (DMP-1), ALP activity, and extracellular matrix mineralization were evaluated. Data were compared using ANOVA (α=5%). Results: Lower cell density was detected only for MTA and CACb+ compared with Control, with areas showing reduced cell spreading. Cell viability was similar among groups at days one and three (p>0.05). CACb+ and MTA showed the lowest cell viability values at day seven (p>0.05). CACb and CACb+ promoted higher ALP and BSP expression compared with CACz (p<0.05); despite that, all cements supported ALP activity. Matrix mineralization were enhanced in CACb+ and MTA. Conclusion: In conclusion, CAC with Bi 2 O3, but not with ZnO, supported the expression of odontoblastic phenotype, but only the composition with 10% CaCl2 promoted mineralized matrix formation, rendering it suitable for dentin-pulp complex repair.

International Journal of Morphology, Dec 1, 2019
Impairing osteoporosis progression is a challenge, and recently the role of antioxidants has been... more Impairing osteoporosis progression is a challenge, and recently the role of antioxidants has been associated to bone metabolism. Green tea extract is rich in catechins, especially epigallocatechin gallate (EGCG), which may help control osteoporosis damage in bone tissue. This investigation evaluated the efficacy of green tea ingestion containing different concentrations of EGCG in calvaria bone repair of ovariectomized rats. Wistar rats (n=15) were ovariectomized and divided into 3 groups: ovariectomized (OVX), ovariectomized + GTE 15 % EGCG (OVX/GTE15), and ovariectomized + GTE 94 % EGCG (OVX/GTE94). Green tea extract was administered by gavage in the concentration of 50 mg/kg and sham group (n=5) received water. Bone defects were performed in the calvaria 60 days after ovariectomy followed by 4 weeks until euthanasia. Bone samples were collected to perform qualitative and quantitative histological analysis of bone formation. Data obtained were submitted to normality and ANOVA statistical test for p<0.05. The mean values of neoformed bone for Sham, OVX, OVX/GTE15 and OVX/GTE94 were respectively: 21.11 ± 3.91; 19.92 ± 2.20; 33.05 ± 1.26 e 34.75 ± 0.54 (p<0.05). Results show that continuous ingestion of green tea extract immediately after ovariectomy shows positive effects in the prevention of bone loss in osteoporosis, even with low concentrations of EGCG.

BMC Genomics
Background The autoimmune regulator (Aire) gene is critical for the appropriate establishment of ... more Background The autoimmune regulator (Aire) gene is critical for the appropriate establishment of central immune tolerance. As one of the main controllers of promiscuous gene expression in the thymus, Aire promotes the expression of thousands of downstream tissue-restricted antigen (TRA) genes, cell adhesion genes and transcription factor genes in medullary thymic epithelial cells (mTECs). Despite the increasing knowledge about the role of Aire as an upstream transcriptional controller, little is known about the mechanisms by which this gene could be regulated. Results Here, we assessed the posttranscriptional control of Aire by miRNAs. The in silico miRNA-mRNA interaction analysis predicted thermodynamically stable hybridization between the 3’UTR of Aire mRNA and miR-155, which was confirmed to occur within the cellular milieu through a luciferase reporter assay. This finding enabled us to hypothesize that miR-155 might play a role as an intracellular posttranscriptional regulator o...

Brazilian Dental Journal, 2020
Recent studies suggest that osteoporosis, in addition to the damage caused in long bones, may cau... more Recent studies suggest that osteoporosis, in addition to the damage caused in long bones, may cause deterioration in the jaws, especially in alveolar bone sites, with effects in the progress of periodontal disease as well as in bone healing. The aim of this study was to evaluate the effect of osteoporosis in the metabolism of rat alveolar bone osteoblasts. There were used 10 female rats divided in two experimental groups (Sham and OVX), which were ovariectomized and after 8 weeks euthanized to collect mandibular bone samples in order to isolate osteoblastic cells. The cells were cultured in 24-well plates to perform the in vitro experiments. After 7, 10 and 14 days, there were evaluated cell proliferation by MTT assay, in situ detection of alkaline phosphatase (ALP) as well as mineralized nodules and expression of genes associated to bone remodeling. Results showed that at 7, 10 and 14 days cell proliferation was lower for OVX group. In situ detection of ALP was higher at 7 days and...

Journal of Applied Oral Science, 2020
Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use... more Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use aiming at periapical tissue repair. However, its effects on dental pulp cells have been poorly explored. Objective: This study assessed the impact of calcium chloride (CaCl 2 ) and bismuth oxide (Bi2O 3 ) or zinc oxide (ZnO) additives on odontoblast cell response to CAC. Methodology: MDPC-23 cells were exposed for up to 14 d: 1) CAC with 2.8% CaCl2 and 25% ZnO (CACz); 2) CAC with 2.8% CaCl2 and 25% Bi 2 O3 (CACb); 3) CAC with 10% CaCl2 and 25% Bi 2 O3 (CACb+); or 4) mineral trioxide aggregate (MTA), placed on inserts. Non-exposed cultures served as control. Cell morphology, cell viability, gene expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), and dentin matrix protein 1 (DMP-1), ALP activity, and extracellular matrix mineralization were evaluated. Data were compared using ANOVA (α=5%). Results: Lower cell density was detected only for MTA and CACb+ compared with Control, with areas showing reduced cell spreading. Cell viability was similar among groups at days one and three (p>0.05). CACb+ and MTA showed the lowest cell viability values at day seven (p>0.05). CACb and CACb+ promoted higher ALP and BSP expression compared with CACz (p<0.05); despite that, all cements supported ALP activity. Matrix mineralization were enhanced in CACb+ and MTA. Conclusion: In conclusion, CAC with Bi 2 O3, but not with ZnO, supported the expression of odontoblastic phenotype, but only the composition with 10% CaCl2 promoted mineralized matrix formation, rendering it suitable for dentin-pulp complex repair.

International Journal of Morphology, 2019
Impairing osteoporosis progression is a challenge, and recently the role of antioxidants has been... more Impairing osteoporosis progression is a challenge, and recently the role of antioxidants has been associated to bone metabolism. Green tea extract is rich in catechins, especially epigallocatechin gallate (EGCG), which may help control osteoporosis damage in bone tissue. This investigation evaluated the efficacy of green tea ingestion containing different concentrations of EGCG in calvaria bone repair of ovariectomized rats. Wistar rats (n=15) were ovariectomized and divided into 3 groups: ovariectomized (OVX), ovariectomized + GTE 15 % EGCG (OVX/GTE15), and ovariectomized + GTE 94 % EGCG (OVX/GTE94). Green tea extract was administered by gavage in the concentration of 50 mg/kg and sham group (n=5) received water. Bone defects were performed in the calvaria 60 days after ovariectomy followed by 4 weeks until euthanasia. Bone samples were collected to perform qualitative and quantitative histological analysis of bone formation. Data obtained were submitted to normality and ANOVA statistical test for p<0.05. The mean values of neoformed bone for Sham, OVX, OVX/GTE15 and OVX/GTE94 were respectively: 21.11 ± 3.91; 19.92 ± 2.20; 33.05 ± 1.26 e 34.75 ± 0.54 (p<0.05). Results show that continuous ingestion of green tea extract immediately after ovariectomy shows positive effects in the prevention of bone loss in osteoporosis, even with low concentrations of EGCG.

Animal Models and Experimental Medicine, 2019
BackgroundThe purpose of the study was to analyze the effect of cell therapy on the repair proces... more BackgroundThe purpose of the study was to analyze the effect of cell therapy on the repair process in calvaria defects in rats subjected to irradiation.MethodsBone marrow mesenchymal cells were characterized for osteoblastic phenotype. Calvariae of male Wistar rats were irradiated (20 Gy) and, after 4 weeks, osteoblastic cells were placed in surgically created defects in irradiated (IRC) and control animals (CC), paired with untreated irradiated (IR) and control (C) animals. After 30 days, histological and microtomographic evaluation was performed to establish significant (P < 0.05) differences among the groups.ResultsHigher alkaline phosphatase detection and activity, along with an increase in mineralized nodules, in the IRC, C and CC groups compared to the IR group, confirmed an osteoblastic phenotype. Histology showed impaired bone neoformation following irradiation, affecting bone marrow composition. Cell therapy in the IRC group improved bone neoformation compared to the IR ...

Journal of Caffeine and Adenosine Research, 2019
Background: Considering the high consumption of caffeinated beverages and its skeletal effects af... more Background: Considering the high consumption of caffeinated beverages and its skeletal effects after onset of osteoporosis, we aimed to evaluate low and moderate in vitro caffeine concentrations in ovariectomized rat osteoblastic cells. Materials and Methods: Cells were cultured with 1 mM (OVX CAF1 ) and 3 mM (OVX CAF3 ) caffeine to assess proliferation, functional activity, and bone marker gene expression. Results: Cell proliferation in OVX CAF1 was similar to C and OVX after 10 and 14 days; OVX CAF3 showed a decrease after all periods. OVX CAF1 had a late increase of in situ ALP and a decrease in OVX CAF3 . Mineralization was similar between C and OVX CAF1 , with a decrease for OVX CAF3 . Genes Alp and Bsp had a higher expression for OVX CAF1 compared with OVX CAF3 . Gene Runx2 was upregulated for OVX CAF1 and OVX CAF3 in both periods, whereas gene Bglap was upregulated for OVX CAF1 and downregulated for OVX CAF3 . Conclusions: Low caffeine concentrations maintained functional activity and promoted the upregulation of bone marker genes of osteoblastic cells from osteoporotic rats.

Brazilian Oral Research, 2019
Recent studies on functional tissue regeneration have focused on substances that favor cell proli... more Recent studies on functional tissue regeneration have focused on substances that favor cell proliferation and differentiation, including the bioactive phenolic compounds present in grape seed extract (GSE). The aim of this investigation was to evaluate the stimulatory potential of GSE in the functional activity of undifferentiated pulp cells and odontoblast-like cells. OD-21 and MDPC-23 cell lines were cultivated in odontogenic medium until subconfluence, seeded in 24-well culture plates in a concentration of 2x10 4 / well and divided into: 1) OD-21 without GSE; 2) OD-21+10 µg/mL of GSE; 3) MDPC-23 without GSE; 4) MDPC-23+10 µg/mL of GSE. Cell proliferation, in situ detection of alkaline phosphatase (ALP) and total protein content were assessed after 3, 7 and 10 days, and mineralization was evaluated after 14 days. The data were analyzed by ANOVA statistical tests set at a 5% level of significance. Results revealed that cell proliferation increased after 10 days, and protein content, after 7 days of culture in MDPC-23 cells. In situ ALP staining intensity was higher in undifferentiated pulp cells and odontoblast-like cells after 7 and 10 days, respectively. A discrete increase in MDPC-23 mineralization after GSE treatment was observed despite OD-21 cells presenting a decrease in mineralized nodule deposits. Data suggest that GSE favors functional activity of differentiated cells more broadly than undifferentiated cells (OD-21). More studies with different concentrations of GSE must be conducted to confirm its benefits to cells regarding dentin regeneration.

Frontiers in immunology, 2018
The function of medullary thymic epithelial cells (mTECs) is associated with thymocyte adhesion, ... more The function of medullary thymic epithelial cells (mTECs) is associated with thymocyte adhesion, which is crucial for the negative selection of autoreactive thymocytes in the thymus. This process represents the root of central tolerance of self-components and prevents the onset of autoimmune diseases. Since thymic epithelia correspond to an important target of donor T cells during the onset of chronic graft-vs-host-disease, mTEC-thymocyte adhesion may have implications for alloimmunity. The and genes function as transcriptome controllers in mTECs. The central question of this study is whether there is a mutual relationship between mTEC-thymocyte adhesion and the control of the mTEC transcriptome and whether Aire is involved in this process. Here, we show that mTEC-thymocyte adhesion causes transcriptome changes in mTECs and upregulates the transcriptional expression of and , as well as cell adhesion-related genes such as or , among others. Crispr-Cas9-mediated gene disruption demons...

Cell biology international, Jan 2, 2017
Investigation on functional genome research may contribute to the knowledge of functional roles o... more Investigation on functional genome research may contribute to the knowledge of functional roles of different mRNAs and miRNAs in bone cells of osteoporotic animals. Currently, few studies indicate the changes in gene modulation that osteoporosis causes in osteoblastic cells from different sites. Thus, the purpose of this investigation was to evaluate cell viability, alkaline phosphatase activity and modulation of mRNAs/miRNAs in osteoblastic cells from calvaria and bone marrow by means of microarray technology. Wistar female rats were divided in sham operated and ovariectomized groups. After 150 days of ovariectomy, cells were isolated from both sites to perform cell culture. Results showed that calvaria cells from ovariectomized rats had a decrease in viability when compared to control groups and to bone marrow cells from osteoporotic rats after 3 days. Alkaline phosphatase activity decreased in calvaria cells from ovariectomized rats whereas it was increased in bone marrow osteobl...

Journal of Cellular Biochemistry, 2017
ABSTRACTWe demonstrate that the interaction between miR‐450a‐5p and miR‐28‐5p and signal transduc... more ABSTRACTWe demonstrate that the interaction between miR‐450a‐5p and miR‐28‐5p and signal transducer and activator of transcription 1 (STAT1) mRNA correlates with the osteoblastic differentiation of mesenchymal stem cells from human exfoliated deciduous teeth (shed cells). STAT1 negatively regulates runx‐related transcription factor 2 (RUNX2), which is an essential transcription factor in this process. However, the elements that trigger osteoblastic differentiation and therefore pause the inhibitory effect of STAT1 need investigation. Usually, STAT1 can be posttranscriptionally regulated by miRNAs. To test this, we used an in vitro model system in which shed cells were chemically induced toward osteoblastic differentiation and temporally analyzed, comparing undifferentiated cells with their counterparts in the early (2 days) or late (7 or 21 days) periods of induction. The definition of the entire functional genome expression signature demonstrated that the transcriptional activity o...

Journal of materials science. Materials in medicine, 2016
Osteoporosis is a chronic disease that impairs proper bone remodeling. Guided bone regeneration i... more Osteoporosis is a chronic disease that impairs proper bone remodeling. Guided bone regeneration is a surgical technique that improves bone defect in a particular region through new bone formation, using barrier materials (e.g. membranes) to protect the space adjacent to the bone defect. The polytetrafluorethylene membrane is widely used in guided bone regeneration, however, new membranes are being investigated. The purpose of this study was to evaluate the effect of P(VDFTrFE)/BT [poly(vinylidene fluoride-trifluoroethylene)/barium titanate] membrane on in vivo bone formation. Twenty-three Wistar rats were submitted to bilateral ovariectomy. Five animals were subjected to sham surgery. After 150 days, bone defects were created and filled with P(VDF-TrFE)/BT membrane or PTFE membrane (except for the sham and OVX groups). After 4 weeks, the animals were euthanized and calvaria samples were subjected to histomorphometric and computed microtomography analysis (microCT), besides real time...
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Papers by Karina Bombonato-prado