ABSTRACT
Legg-Calve-Perthes disease (LCPD) is an idiopathic avascular necrosis of the pediatric femoral head. Bone remodeling and bone structural genes have the potential to contribute to the progression of LCPD when there is disequilibrium between bone resorption and bone formation. A case-control study was performed to search for associations of several common polymorphisms in the genes Receptor Activator for Nuclear Factor κappa B (RANK), Receptor Activator for Nuclear Factor κappa B Ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, and type 1 collagen (COL1A1) with LCPD susceptibility in Mexican children. A total of 23 children with LCPD and 46 healthy controls were genotyped for seven polymorphisms (rs3018362, rs12585014, rs2073618, rs1800795, rs1800796, rs1800012, and rs2586498) in the RANK, RANKL, OPG, IL-6, and COL1A1 genes by real-time polymerase chain reaction with TaqMan probes. The variant allele (C) of IL-6 rs1800795 was associated with increased risk of LCPD (odds ratio [OR]: 3.8, 95% confidence interval [CI]: [1.08-13.54], p = 0.033), adjusting data by body mass index (BMI) and coagulation factor V (FV), the association with increased risk remained (OR: 4.9, 95% CI: [1.14-21.04], p = 0.025). The OPG polymorphism rs2073618, specifically GC-GG carriers, was associated with a more than fourfold increased risk of developing LCPD (OR: 4.34, 95% CI: [1.04-18.12], p = 0.033) when data were adjusted by BMI-FV. There was no significant association between RANK rs3018362, RANKL rs12585014, IL-6 rs1800796, COL1A1 rs1800012, and rs2586498 polymorphisms and LCPD in a sample of Mexican children. The rs1800975 and rs2037618 polymorphisms in the IL-6 and OPG genes, respectively, are informative markers of increased risk of LCPD in Mexican children.
Subject(s)
Bone Remodeling , Genetic Predisposition to Disease , Interleukin-6 , Legg-Calve-Perthes Disease , Osteoprotegerin , Polymorphism, Single Nucleotide , RANK Ligand , Humans , Osteoprotegerin/genetics , Legg-Calve-Perthes Disease/genetics , Interleukin-6/genetics , Male , Female , Mexico , Child , Case-Control Studies , Bone Remodeling/genetics , RANK Ligand/genetics , Collagen Type I/genetics , Collagen Type I, alpha 1 Chain/genetics , Child, Preschool , Receptor Activator of Nuclear Factor-kappa B/geneticsABSTRACT
The aim of this study was to analyze the expression of mBD4, mBD3 and CRAMP in joint of mice with type II collagen-induced arthritis/CIA and to explore its possible association with IL-10, IL-4, IFN-γ, IL-17, MMP3, RANK/RANKL/OPG and histological parameters. METHODS: CIA was induced in 44 DBA/1 J mice. The joints from mice were classified into the onset, peak and remission phase of CIA. Histological sections were stained with hematoxylin-eosin and safranin O. The expression of CRAMP, mBD-3, mBD-4, and MMP-3 was evaluated using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. The expression of IL-10, IL-4, IFN-γ, IL-17, RANK/RANKL/OPG was analyzed by RT-PCR. RESULTS: We observed that inflammation and immunostained cells for CRAMP increased in the peak and remission phases compared to the control group. In addition, increments in relative expressions of CRAMP were detected for the remission phase and in IL-4 and IL-17 in the peak phase compared to the control and onset phase. In addition, an increase in IL-10 in a peak phase compared to the control, as well as the relative expression of IFN-γ in remission phase was higher than in the onset phase. This was accompanied by an increase in cartilage damage in the peak phase compared to the control. Cells immunostained to MMP3 increased in the peak phase compared to the onset and control group, and relative expression of MMP3 was detected in the peak phase compared to the onset, remission, and control group. We observed that the relative expression of RANK and RANKL in the peak phase was higher than in control and onset phase. Finally, the relative expression of OPG in the peak phase compared to the onset, remission, and control group was detected. Regarding CRAMP behavior in the different phases studied, it was positively correlated with IL-4 and RANK, and showed a negative correlation with IFN-γ, IL-17, IL-10, RANKL, OPG and RANKL/OPG ratio in the control group. Also was positively correlated with IFN-γ, IL-17, IL-4, IL-10, as well as with RANK, RANKL, and OPG in the onset and peak phases of the CIA. In the peak phase, CRAMP showed a positive association with MMP3, and we observed a direct correlation between CRAMP and IFN-γ and RANKL/OPG ratio in remission phase. mBD3 correlates positively with IFN-γ, IL-17, IL-10, RANKL, OPG and RANKL/OPG ratio, and showed a negative correlation with CRAMP, MMP3, and RANK in the control group. Also, it was directly associated with IFN-γ, IL-17, IL-4, IL-10 and RANKL in the onset phase while it was inversely associated with CRAMP, MMP-3, RANK, RANKL, and OPG in the peak phase. Finally, mBD3 was inversely correlated with MMP3 in the remission phase and was directly associated with CRAMP, IFN-γ and RANKL/OPG ratio in this phase. mBD4 was directly associated with CRAMP, IFN-γ, IL-17, IL-4, IL-10, RANKL / OPG in the onset phase, and with CRAMP, IFN-γ, IL-17, IL-4, IL-10, MMP3, RANK, RANKL and OPG in the peak phase. Finally, mBD4 was positively associated with mBD3, IFN-γ, IL-17, IL-10, RANK, RANKL OPG and RANKL/OPG in the CIA remission phase. CONCLUSIONS: Our results demonstrate that CRAMP plays an important role in CIA progress and suggest that its abundance is associated with local pro- and anti-inflammatory status. This makes us propose CRAMP as a possible contributor of bone reconstruction in the last stage of CIA.
Subject(s)
Arthritis/genetics , Bone Remodeling/genetics , Cathelicidins/genetics , DNA-Binding Proteins/genetics , Transcription Factors/genetics , beta-Defensins/genetics , Animals , Arthritis/chemically induced , Arthritis/pathology , Collagen Type II/toxicity , Gene Expression Regulation/genetics , Humans , Inflammation/genetics , Inflammation/pathology , MiceABSTRACT
AIMS: We investigate the effects of RT on the mechanical function, gene, and protein expression of key factors involved in bone remodeling during aging. MAIN METHODS: Male rats of 3 and 21 months of age were randomly allocated into four groups (8 per group): young sedentary (YS), young trained (YT), old sedentary (OS), and old trained (OT). RT was performed three times per week (12 weeks). Bone tenacity and stiffness were measured by biomechanical tests and mRNA levels of COL1A1, MEPE, SOST, OPG, BMP-2, PPAR-y, MMP-2-9-13, and TIMP-1 were evaluated by quantitative PCR. COL1A1 protein and MMP-2 activity were detected by western blotting and zymography assays. KEY FINDINGS: Aging increased stiffness, while BMP-2, OPG, COL1A1 and MMP-2 mRNA levels reduced (OS vs YS; p ≤ 0.05). RT increased the tenacity of the femur and reduced PPAR-γ regardless of age (YT vs. YS; OT vs. OS; p ≤ 0.05). RT downregulated SOST mRNA levels only in the OT group (vs. OS group, p ≤ 0.05). RT mitigated the age-associated increase in MMP-9 mRNA levels (p ≤ 0.05). In young animals, upregulation in MEPE, MMP-13, TIMP-1 were observed after RT, as well an increase in COL1A1 protein and MMP-2 activity (p ≤ 0.05). SIGNIFICANCE: RT improved bone tenacity independent of aging, which is relevant for mechanical function, while, at protein levels, RT upregulated MMP-2 activity and collagen 1 only in young rats. This study highlights the importance of exercise on bone health and identifies specific molecular changes in response to RT. Our findings provide insights into the mechanisms involved in age-related changes.
Subject(s)
Aging/physiology , Bone Remodeling/physiology , Physical Conditioning, Animal/physiology , Resistance Training/methods , Age Factors , Animals , Bone Remodeling/genetics , Gene Expression Regulation/physiology , Male , RNA, Messenger/genetics , Random Allocation , Rats , Rats, WistarABSTRACT
Osteoporosis is the most common bone disease and a public health issue with increasing prevalence in Mexico. This disease is caused by an imbalance in the bone remodelling process mediated by osteoclast and osteoblast. MicroRNAs have emerged as key players during the differentiation of both types of cells specialized involved in bone metabolism. We found high expression levels of miR-548x-3p in circulating monocytes derived from postmenopausal osteoporotic women. This study aimed to analyse the functional characterization of miR-548x-3p roles in the bone remodelling process. We validated by RT-qPCR, the elevated levels of miR-548x-3p in circulating monocytes derived from osteoporosis women. Through bioinformatics analysis, we identify MAFB and STAT1 as potential target genes for miR-548x-3p. Both genes showed low levels of expression in circulating monocytes derived from osteoporotic women. In addition, we demonstrated the binding of miR-548x-3p to the 3'-UTR of both mRNAs. MiR-548x-3p was overexpressed in osteoblasts-like cell lines decreasing the levels of MAFB and STAT1 mRNA and protein. We found that miR-548x-3p overexpression inhibits the proliferation, migration and invasion of the cell lines evaluated. Our results identified, by the first time, the potential role of miR-548x-3p as a modulator of the bone remodelling process by regulating the expression of MAFB and STAT1.
Subject(s)
Cell Movement/genetics , Cell Proliferation/genetics , MafB Transcription Factor/genetics , MicroRNAs/metabolism , Osteoblasts/metabolism , Osteoporosis/blood , STAT1 Transcription Factor/genetics , Animals , Bone Remodeling/genetics , Cell Differentiation/genetics , Cell Line, Tumor , Cohort Studies , Female , Gene Expression Regulation , Humans , MafB Transcription Factor/metabolism , Mice , MicroRNAs/genetics , Monocytes/metabolism , Osteoclasts/metabolism , Postmenopause/blood , RAW 264.7 Cells , STAT1 Transcription Factor/metabolism , TransfectionABSTRACT
Hypovitaminosis D, defined by low serum levels of 25(OH)D, is a recognized worldwide public health problem. The most accepted definition considers that deficiency occurs with serum levels fall below 12 ng/ml of 25(OH)D. Long term vitamin D deficiency results in decreased bone mineralization, secondary hyperparathyroidism, increased cortical bone loss (pathogenesis of osteoporosis and hip fractures), differentiation and division of various cell types, muscle strength, diabetes type 2, blood pressure, etc. Twin- and family-based studies indicate that genetic factors influence serum 25(OH)D levels. Genetic studies have shown single-nucleotide polymorphisms (SNPs) are linked to low serum 25(OH)D concentrations through changes in the activity of the enzymes of the 1a,25(OH)2D metabolic pathway. Carriers of high genetic risk scores would need a h igher amount of vitamin D supplementation to achieve adequate serum 25(OH)D concentrations. Clinicians would not need to indicate studies to identify patients with vitamin D insufficiency of genetic origin. They should instruct their patients on their own care, to control the intake of vitamin D and the serum 25(OH)D levels until the latter are adequate. Overall, the literature reveals that the consequences of hypovitaminosis D on bone health are observed in old and infrequently in young subjects. A probable explanation for the latter is: if the rate of bone remodeling allows it, bone tissue has endogenous (genetics, hormones) and exogenous determinants (diet, physical activity) that may compensate the variables of bone health. The consequences of vitamin D deficit on bone health, has not been completely uncovered.
La hipovitaminosis D, definida por bajos niveles séricos de 25(OH)D (<12 ng/ml), es un reconocido problema de salud pública mundial. La deficiencia de vitamina D a largo plazo resulta en una disminución de la mi neralización ósea, hiperparatiroidismo secundario, pérdida de hueso cortical (patogénesis de la osteoporosis y fracturas de cadera), diferenciación y división de varios tipos de células, fuerza muscular, diabetes tipo 2, pres ión arterial, etc. Estudios genéticos han demostrado que algunos "polimorfismos de un solo nucleótido" (SNP) están relacionados con bajas concentraciones séricas de 25(OH)D a través de reducción en la actividad de las enzimas implicadas en la síntesis de 1a,25(OH)2D. Los médicos no necesitan indicar un estudio genético para identificar a la insuficiencia de vitamina D de causa genética. Bastará con instruir a los pacientes sobre su propio cuidado y controlar la ingesta de vitamina D y los niveles séricos de 25(OH)D hasta que estos últimos sean adecuados. En general, la literatura revela que las consecuencias de la hipovitaminosis D sobre la salud ósea se observan en las personas añosas y con poca frecuencia en sujetos jóvenes. Una explicación probable para esta situación es: si la tasa de remodelación ósea lo permite, el tejido óseo tiene factores endógenos (genéticos, hormonales) y exógenos (dieta, actividad física) que pueden compensar las variables de la salud ósea. Las consecuencias del déficit de vitamina D sobre la salud ósea aún no se conocen completamente.
Subject(s)
Bone Remodeling/genetics , Vitamin D Deficiency/genetics , Bone Remodeling/physiology , Female , Humans , Male , Parathyroid Hormone/blood , Polymorphism, Single Nucleotide , Vitamin D Deficiency/bloodABSTRACT
Hypovitaminosis D, defined by low serum levels of 25(OH)D, is a recognized worldwide public health problem. The most accepted definition considers that deficiency occurs with serum levels fall below 12 ng/ml of 25(OH)D. Long term vitamin D deficiency results in decreased bone mineralization, secondary hyperparathyroidism, increased cortical bone loss (pathogenesis of osteoporosis and hip fractures), differentiation and division of various cell types, muscle strength, diabetes type 2, blood pressure, etc. Twin- and family-based studies indicate that genetic factors influence serum 25(OH)D levels. Genetic studies have shown single-nucleotide polymorphisms (SNPs) are linked to low serum 25(OH)D concentrations through changes in the activity of the enzymes of the 1α,25(OH)2D metabolic pathway. Carriers of high genetic risk scores would need a h igher amount of vitamin D supplementation to achieve adequate serum 25(OH)D concentrations. Clinicians would not need to indicate studies to identify patients with vitamin D insufficiency of genetic origin. They should instruct their patients on their own care, to control the intake of vitamin D and the serum 25(OH)D levels until the latter are adequate. Overall, the literature reveals that the consequences of hypovitaminosis D on bone health are observed in old and infrequently in young subjects. A probable explanation for the latter is: if the rate of bone remodeling allows it, bone tissue has endogenous (genetics, hormones) and exogenous determinants (diet, physical activity) that may compensate the variables of bone health. The consequences of vitamin D deficit on bone health, has not been completely uncovered.
La hipovitaminosis D, definida por bajos niveles séricos de 25(OH)D (<12 ng/ml), es un reconocido problema de salud pública mundial. La deficiencia de vitamina D a largo plazo resulta en una disminución de la mi neralización ósea, hiperparatiroidismo secundario, pérdida de hueso cortical (patogénesis de la osteoporosis y fracturas de cadera), diferenciación y división de varios tipos de células, fuerza muscular, diabetes tipo 2, pres ión arterial, etc. Estudios genéticos han demostrado que algunos "polimorfismos de un solo nucleótido" (SNP) están relacionados con bajas concentraciones séricas de 25(OH)D a través de reducción en la actividad de las enzimas implicadas en la síntesis de 1α,25(OH)2D. Los médicos no necesitan indicar un estudio genético para identificar a la insuficiencia de vitamina D de causa genética. Bastará con instruir a los pacientes sobre su propio cuidado y controlar la ingesta de vitamina D y los niveles séricos de 25(OH)D hasta que estos últimos sean adecuados. En general, la literatura revela que las consecuencias de la hipovitaminosis D sobre la salud ósea se observan en las personas añosas y con poca frecuencia en sujetos jóvenes. Una explicación probable para esta situación es: si la tasa de remodelación ósea lo permite, el tejido óseo tiene factores endógenos (genéticos, hormonales) y exógenos (dieta, actividad física) que pueden compensar las variables de la salud ósea. Las consecuencias del déficit de vitamina D sobre la salud ósea aún no se conocen completamente.
Subject(s)
Humans , Male , Female , Vitamin D Deficiency/genetics , Bone Remodeling/genetics , Parathyroid Hormone/blood , Vitamin D Deficiency/blood , Bone Remodeling/physiology , Polymorphism, Single NucleotideABSTRACT
Natural molecules, such as flavonoid, are very welcome strategies to modulate bone turnover. This prompted us to comprehend better the effect of silibinin on osteoblast metabolism, mainly considering intracellular pathways able to drive cell adhesion to differentiation. By exploring in vitro approaches, our data show a modulatory effect of the silibinin (200 µg/mL) on the osteoblast intracellular signaling, contributing with decisive pathways governing cell adhesion, differentiation, and further mineralization, recapitulating important stages of osteogenesis. Within the first 24 hours of adhesion (acute stage), osteoblasts respond to silibinin by rearranging their cytoskeleton and start mechanisms responsible to extracellular matrix (ECM) remodeling, which reach intense profile at 28 days of treatment (chronic stage) by favoring matrix metalloproteinases (MMPs-2, and -9) activities, concomitant to mineralizing phenotype. Importantly, silibinin seems to reprogram genes related to inflammatory landscape and significantly upmodulating osteoprotegerin (>25 fold-changes), signaling molecule involved with osteoclastogenesis. Altogether, our results show for the first time that silibinin drives in vitro osteoblast differentiation by requiring specific intracellular signaling. In conjunction, this molecular landscape contributes to understand the effect of silibinin on osteoblasts performance and open novel therapeutic possibilities to silibinin in bone disorders, such as osteoporosis.
Subject(s)
Inflammation/drug therapy , Osteogenesis/drug effects , Osteoporosis/drug therapy , Silybin/pharmacology , Animals , Bone Remodeling/drug effects , Bone Remodeling/genetics , Cell Adhesion/drug effects , Cell Adhesion/genetics , Cell Differentiation/drug effects , Cell Line , Cell Proliferation/drug effects , Extracellular Matrix/drug effects , Humans , Inflammation/genetics , Inflammation/pathology , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 9/genetics , Mice , Osteoblasts/drug effects , Osteogenesis/genetics , Osteoporosis/genetics , Osteoporosis/pathology , Phenotype , Signal Transduction/drug effectsABSTRACT
We investigated the effects of cigarette smoke (CS) and resveratrol intake on the modulation of bone repair-related genes through epigenetic mechanisms at the global and gene-specific levels, after 30 days of calvarial defects were created, in rats. The samples were assigned to three groups as follows: no CS, CS, and CS/resveratrol. After evaluation of global (5 hmC) changes and epigenetic and transcription regulation at gene-specific levels, CS group showed increased 5 hmC and Tets transcripts with demethylation at Rankl and Trap promoters (p ≤ 0.01), linked to their increased gene expression (p ≤ 0.001). These modifications were reverted in the CS/resveratrol group. Opposite patterns were observed among CS and CS/resveratrol for epigenetic enzyme transcripts with higher levels of Dnmts in the CS/resveratrol (p ≤ 0.01). No CS and CS/resveratrol demonstrated similar gene expression levels for all Tets and bone-related genes. Resveratrol reverts epigenetic and transcription changes caused by CS at both global and gene-specific levels in bone-related and epigenetic machinery genes, emphasizing the resveratrol as biological modulator for CS in rats.
Subject(s)
Cytoprotection/drug effects , Epigenesis, Genetic/drug effects , Osteogenesis/drug effects , Osteogenesis/genetics , Stilbenes/pharmacology , Tobacco Smoke Pollution/adverse effects , Animals , Bone Remodeling/drug effects , Bone Remodeling/genetics , Bone and Bones/drug effects , Bone and Bones/metabolism , Cytoprotection/genetics , Gene Expression Regulation/drug effects , Inhalation Exposure/adverse effects , Male , Rats , Rats, Wistar , Resveratrol , Nicotiana/adverse effectsABSTRACT
Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher's exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.
Subject(s)
Bone Remodeling/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Neovascularization, Pathologic/genetics , Periapical Periodontitis/genetics , Polymorphism, Genetic , Adult , Brazil , DNA/genetics , Female , Gene Frequency , Genotype , Humans , Male , Middle Aged , Periapical Periodontitis/pathology , Real-Time Polymerase Chain Reaction , Root Canal TherapyABSTRACT
Abstract Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher's exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.
Resumo A periodontite apical persistente (PAP) é uma condição que envolve uma resposta inflamatória e imunológica causada principalmente por infecções polimicrobianas de origem anaeróbia no sistema de canais radiculares, tornando o resultado e o acompanhamento do tratamento do canal radicular intimamente relacionados à resposta do hospedeiro. O reparo da periodontite apical pode estar associado a polimorfismos genéticos. Este estudo teve como objetivo avaliar a associação entre os polimorfismos genéticos do HIF1A (rs2301113 e rs2057482) com a PAP em pacientes brasileiros. Indivíduos com pelo menos 1 ano de acompanhamento após o tratamento do canal radicular (TCR) foram agendados para consulta de acompanhamento. Sessenta e quatro indivíduos com sinais/sintomas de PAP e 84 indivíduos com dentes tratados endodonticamente e tecidos perirradiculares saudáveis (cicatrizados) foram incluídos no presente estudo. O DNA genômico foi extraído da saliva e utilizado para a genotipagem do HIF1A por PCR em tempo real. O genótipo e as frequências alélicas foram comparados por teste c2 ou exato de Fisher e odds-ratio foi implementado por meio do software Epi Info 3.5.2. Todos os testes realizados foram estabelecidos com a=0,05. Não houve associação entre alelo e distribuição genotípica para polimorfismos do HIF1A e PAP (p> 0,05). Os polimorfismos genéticos em HIF1A não foram associados à periodontite apical persistente.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Periapical Periodontitis/genetics , Polymorphism, Genetic , Bone Remodeling/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Neovascularization, Pathologic/genetics , Periapical Periodontitis/pathology , Root Canal Therapy , Brazil , DNA/genetics , Real-Time Polymerase Chain Reaction , Gene Frequency , GenotypeABSTRACT
INTRODUCTION: Bone remodeling is a tightly regulated process influenced by chemokines. ACKR2 is a decoy receptor for CC chemokines functioning as regulator of inflammatory response. In this study we investigated whether the absence of ACKR2 would affect bone phenotype and remodeling induced by mechanical loading. METHODS: An orthodontic appliance was placed between incisors and first molar of ACKR2 deficient (ACKR2-/-) and C57BL6/J (wild-type/WT) mice. Microtomography, histology and qPCR were performed to evaluate bone parameters, orthodontic tooth movement (OTM), bone cells counts and the expression of ACKR2, bone remodeling markers, CC chemokines and chemokines receptors. Bone marrow cells (BMC) from WT and ACKR2-/- mice were differentiated in osteoclasts and osteoblasts for analysis of activity and expression of specific markers. RESULTS: Mechanical stimulus induced ACKR2 production in periodontium. The expression of ACKR2 in vitro was mostly detected in mature osteoclasts and early-differentiated osteoblasts. Although ACKR2-/- mice exhibited regular phenotype in maxillary bone, the amount of OTM, osteoclasts counts and the expression of pro-resorptive markers were increased in this group. In contrast, the number of osteoblasts and related markers were decreased. OTM resulted in augmented expression of CC chemokines and receptors CCR5 and CCR1 in periodontium, which was higher in ACKR2-/- than WT mice. In vitro experiments demonstrated an augmented formation of osteoclasts and diminished differentiation of osteoblasts in ACKR2-/- mice. CONCLUSIONS: These data suggests that ACKR2 functions as a regulator of mechanically-induced bone remodeling by affecting the differentiation and activity of bone cells and the availability of CC chemokines at periodontal microenvironment. Therapeutic strategies based on increase of ACKR2 might be useful to hinder bone loss in inflammatory conditions.
Subject(s)
Bone Remodeling/physiology , Receptors, Chemokine/metabolism , Animals , Bone Remodeling/genetics , Cell Differentiation/genetics , Cell Differentiation/physiology , Cell Survival/genetics , Cell Survival/physiology , Chemokines/metabolism , Mice , Mice, Inbred C57BL , Osteoblasts/cytology , Osteoblasts/metabolism , Osteoclasts/cytology , Osteoclasts/metabolism , Real-Time Polymerase Chain Reaction , Receptors, Chemokine/geneticsABSTRACT
Osteoporosis is a multifactorial and debilitating disease resulting from decreased bone mineral density (BMD) and loss of tissue microarchitecture. Ineffective therapies may lead to bone fractures and subsequent death. Single nucleotide polymorphisms (SNPs) in key immune regulator genes have been associated with therapeutic response to bisphosphonates, which are the first therapeutic line of choice for osteoporosis. However, cytokine pathways and their relation with therapeutic adhesion remain to be fully elucidated. Aimed at better understanding these processes, we investigated the response to bisphosphonate therapy in postmenopausal women and four SNPs in key proinflammatory cytokines genes: IL23R +2284 (C>A) (rs10889677), IL17A +672 (G>A) (rs7747909), IL12B +1188 (T>G) (rs3212227) and INF-γ -1616 (G>A) (rs2069705). A total of 69 patients treated with bisphosphonate were followed for a period of 1 up to 4 years, genotyped and compared according to their changes in bone mineral density (BMD) and level of biochemical markers during their treatment. The INF-γ -1616 G/G associated with increased BMD values in femoral neck (GG/AA, p = 0.016) and decreased BMD values in total hip (GG/GA, p = 0.019; GG/AA, p = 0.011). In relation to biochemical markers, INF-γ -1616 SNP associated with increased alkaline phosphatase (GG/AA; p < 0.0001) and parathyroid hormone levels (AA/GA; p = 0.017). Vitamin D values changes were related to IL17A +672 (GG/GA, p = 0.034) and to IL12B +1188 (TT/TG, p = 0.046) SNPs. Besides, significant differences in changes of calcium levels correlated with IL23R +2284 (CC/CA, p = 0.016) genotypes. Altogether, we suggest that these polymorphisms may play an important role for therapeutic decisions in osteoporosis treatment.
Subject(s)
Bone Density/genetics , Cytokines/genetics , Diphosphonates/pharmacology , Osteoporosis, Postmenopausal/genetics , Polymorphism, Single Nucleotide/genetics , Postmenopause/genetics , Aged , Bone Density/drug effects , Bone Remodeling/drug effects , Bone Remodeling/genetics , Cytokines/metabolism , Diphosphonates/therapeutic use , Female , Humans , Middle Aged , Osteoporosis, Postmenopausal/drug therapy , Osteoporosis, Postmenopausal/metabolism , Postmenopause/drug effects , Postmenopause/metabolismABSTRACT
OBJECTIVE: Growth hormone (GH)/insulin-like growth factor (IGF) axis and insulin are key determinants of bone remodelling. Homozygous mutations in the GH-releasing hormone receptor (GHRHR) gene (GHRHR) are a frequent cause of genetic isolated GH deficiency (IGHD). Heterozygosity for GHRHR mutation causes changes in body composition and possibly an increase in insulin sensitivity, but its effects on bone quality are still unknown. The objective of this study was to assess the bone quality and metabolism and its correlation with insulin sensitivity in subjects heterozygous for a null mutation in the GHRHR. PATIENTS AND METHODS: A cross-sectional study was performed on 76 normal subjects (68·4% females) (N/N) and 64 individuals (64·1% females) heterozygous for a mutation in the GHRHR (MUT/N). Anthropometric features, quantitative ultrasound (QUS) of the heel, bone markers [osteocalcin (OC) and CrossLaps], IGF-I, glucose and insulin were measured, and homeostasis model assessment of insulin resistance (HOMA(IR) ) was calculated. RESULTS: There were no differences in age or height between the two groups, but weight (P = 0·007) and BMI (P = 0·001) were lower in MUT/N. There were no differences in serum levels of IGF-I, glucose, T-score or absolute values of stiffness and OC, but insulin (P = 0·01), HOMA(IR) (P = 0·01) and CrossLaps (P = 0·01) were lower in MUT/N. There was no correlation between OC and glucose, OC and HOMA(IR) in the 140 individuals as a whole or in the separate MUT/N or N/N groups. CONCLUSIONS: This study suggests that one allele mutation in the GHRHR gene has a greater impact on energy metabolism than on bone quality.
Subject(s)
Bone Remodeling/genetics , Haploinsufficiency , Insulin Resistance/genetics , Receptors, Neuropeptide/genetics , Receptors, Pituitary Hormone-Regulating Hormone/genetics , Adult , Aged , Bone Density/genetics , Bone Remodeling/physiology , Brazil , Case-Control Studies , Cross-Sectional Studies , Female , Growth Hormone/deficiency , Humans , Male , Middle Aged , Mutation , Osteocalcin/blood , Receptors, Neuropeptide/deficiency , Receptors, Pituitary Hormone-Regulating Hormone/deficiencyABSTRACT
BACKGROUND: Osteosarcoma is a very aggressive tumor with a propensity to metastasize and invade surrounding tissue. Identification of the molecular determinants of invasion and metastatic potential may guide the development of a rational strategy for devising specific therapies that target the pathways leading to osteosarcoma. METHODS: In this study, we used pathway-focused low density expression cDNA arrays to screen for candidate genes related to tumor progression. Expression patterns of the selected genes were validated by real time PCR on osteosarcoma patient tumor samples and correlated with clinical and pathological data. RESULTS: THBS3, SPARC and SPP1 were identified as genes differentially expressed in osteosarcoma. In particular, THBS3 was expressed at significantly high levels (p = 0.0001) in biopsies from patients with metastasis at diagnosis, which is a predictor of worse overall survival, event-free survival and relapse free survival at diagnosis. After chemotherapy, patients with tumors over-expressing THBS3 have worse relapse free survival. High SPARC expression was found in 51/55 (96.3%) osteosarcoma samples derived from 43 patients, and correlated with the worst event-free survival (p = 0.03) and relapse free survival (p = 0.07). Overexpression of SPP1 was found in 47 of 53 (89%) osteosarcomas correlating with better overall survival, event-free survival and relapse free survival at diagnosis. CONCLUSION: In this study three genes were identified with pattern of differential gene expression associated with a phenotypic role in metastasis and invasion. Interestingly all encode for proteins involved in extracellular remodeling suggesting potential roles in osteosarcoma progression. This is the first report on the THBS3 gene working as a stimulator of tumor progression. Higher levels of THBS3 maintain the capacity of angiogenesis. High levels of SPARC are not required for tumor progression but are necessary for tumor growth and maintenance. SPP1 is not necessary for tumor progression in osteosarcoma and may be associated with inflammatory response and bone remodeling, functioning as a good biomarker.
Subject(s)
Bone Neoplasms/metabolism , Gene Expression Regulation, Neoplastic/physiology , Osteonectin/biosynthesis , Osteopontin/biosynthesis , Osteosarcoma/metabolism , Thrombospondins/biosynthesis , Adolescent , Adult , Biomarkers, Tumor/biosynthesis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/physiology , Bone Neoplasms/genetics , Bone Neoplasms/pathology , Bone Remodeling/genetics , Cell Proliferation , Child , Child, Preschool , Disease-Free Survival , Female , Humans , Infant , Infant, Newborn , Male , Oligonucleotide Array Sequence Analysis , Osteonectin/genetics , Osteonectin/physiology , Osteopontin/genetics , Osteopontin/physiology , Osteosarcoma/genetics , Osteosarcoma/pathology , Prospective Studies , Thrombospondins/genetics , Thrombospondins/physiologyABSTRACT
Craniometaphyseal dysplasia is a rare genetic bone remodeling disorder characterized by undertubulation of the long bones, especially in the lower extremities, causing deformities of the metaphyses of the long bones, and sclerosis of the skull base or cranial bone hyperostosis. The authors report a case of craniometaphyseal dysplasia in an 8-year-old Brazilian child, emphasizing the importance of precocious diagnosis of this rare genetic disorder.