scholarly journals Long Term Cyclic Pamidronate Reduces Bone Growth by Inhibiting Osteoclast Mediated Cartilage-to-Bone Turnover in the Mouse

2008 ◽  
Vol 2 (1) ◽  
pp. 121-125 ◽  
Author(s):  
K.D Evans ◽  
L.E Sheppard ◽  
D.I Grossman ◽  
S.H Rao ◽  
R.B Martin ◽  
...  
Keyword(s):  
Bone Turnover ◽  
Growth Plate ◽  
Bone Growth ◽  
Cathepsin K ◽  
Chondrocyte Apoptosis ◽  
Cell Numbers ◽  
Hypertrophic Chondrocyte ◽  
Osteoclast Function ◽  
And Function

Bisphosphonates, used to treat diseases exhibiting increased osteoclast activity, reduce longitudinal bone growth through an as yet undefined mechanism. Pamidronate, an aminobisphosphonate, was given weekly to mice at 0, 1.25, or 2.50 mg/kg/wk beginning at 4 weeks of age. At 12 weeks of age, humeral length, growth plate area, regional chondrocyte cell numbers, chondrocyte apoptosis, TRAP stained osteoclast number, and osteoclast function assessed by cathepsin K immunohistochemistry were quantified. Humeral length was decreased in pamidronate treated mice compared to vehicle control mice, and correlated with greater growth plate areas reflecting greater proliferative and hypertrophic chondrocyte cell numbers with fewer hypertrophic cells undergoing apoptosis. Pamidronate treatment increased TRAP stained osteoclast numbers yet decreased cathepsin K indicating that pamidronate repressed osteoclast maturation and function. The data suggest that long term cyclic pamidronate treatment impairs bone growth by inhibition of osteoclast maturation thereby reducing cartilage-to-bone turnover within the growth plate.

scholarly journals Effect of Bisphosphonates on the Rapidly Growing Male Murine Skeleton

Endocrinology ◽  
2014 ◽  
Vol 155 (4) ◽  
pp. 1188-1196 ◽  
Author(s):  
Eric D. Zhu ◽  
Leeann Louis ◽  
Daniel J. Brooks ◽  
Mary L. Bouxsein ◽  
Marie B. Demay
Keyword(s):  
Bone Loss ◽  
Osteogenesis Imperfecta ◽  
Growth Plate ◽  
Bone Growth ◽  
Pediatric Population ◽  
Chondrocyte Apoptosis ◽  
Trabecular Microarchitecture ◽  
Hypertrophic Chondrocyte ◽  
Treatment And Prevention ◽  
Prevention Of Bone Loss

Bisphosphonates are effective for preventing and treating skeletal disorders associated with hyperresorption. Their safety and efficacy has been studied in adults where the growth plate is fused and there is no longitudinal bone growth and little appositional growth. Although bisphosphonate use in the pediatric population was pioneered for compassionate use in the treatment of osteogenesis imperfecta, they are being increasingly used for the treatment and prevention of bone loss in children at risk of hyperresorptive bone loss. However, the effect of these agents on the growing skeleton in disorders other than osteogenesis imperfecta has not been systematically compared. Studies were, therefore, undertaken to examine the consequences of bisphosphonate administration on the growth plate and skeletal microarchitecture during a period of rapid growth. C57Bl6/J male mice were treated from 18 to 38 days of age with vehicle, alendronate, pamidronate, zoledronate, or clodronate at doses selected to replicate those used in humans. Treatment with alendronate, pamidronate, and zoledronate, but not clodronate, led to a decrease in the number of chondrocytes per column in the hypertrophic chondrocyte layer. This was not associated with altered hypertrophic chondrocyte apoptosis or vascular invasion at the growth plate. The effects of pamidronate on trabecular microarchitecture were less beneficial than those of alendronate and zoledronate. Pamidronate did not increase cortical thickness or cortical area/total area relative to control mice. These studies suggest that bisphosphonate administration does not adversely affect skeletal growth. Long-term investigations are required to determine whether the differences observed among the agents examined impact biomechanical integrity of the growing skeleton.

scholarly journals Nuclear Factor-κB p65 Facilitates Longitudinal Bone Growth by Inducing Growth Plate Chondrocyte Proliferation and Differentiation and by Preventing Apoptosis

2007 ◽  
Vol 282 (46) ◽  
pp. 33698-33706 ◽  
Author(s):  
Shufang Wu ◽  
Janna K. Flint ◽  
Geoffrey Rezvani ◽  
Francesco De Luca
Keyword(s):  
Growth Plate ◽  
Bone Growth ◽  
Chondrocyte Apoptosis ◽  
Pyrrolidine Dithiocarbamate ◽  
Growth Plate Chondrocytes ◽  
Chondrocyte Proliferation ◽  
Longitudinal Bone Growth ◽  
Metatarsal Bones ◽  
Proliferation And Differentiation ◽  
Cultured Chondrocytes

NF-κB is a group of transcription factors involved in cell proliferation, differentiation, and apoptosis. Mice deficient in the NF-κB subunits p50 and p52 have retarded growth, suggesting that NF-κB is involved in bone growth. Yet, it is not clear whether the reduced bone growth of these mice depends on the lack of NF-κB activity in growth plate chondrocytes. Using cultured rat metatarsal bones and isolated growth plate chondrocytes, we studied the effects of two NF-κB inhibitors (pyrrolidine dithiocarbamate (PDTC) or BAY11-7082 (BAY)), p65 short interference RNA (siRNA), and of the overexpression of p65 on chondrocyte proliferation, differentiation, and apoptosis. To further define the underlying mechanisms, we studied the functional interaction between NF-κB p65 and BMP-2 in chondrocytes. PDTC and BAY suppressed metatarsal linear growth. Such growth inhibition resulted from decreased chondrocyte proliferation and differentiation and from increased chondrocyte apoptosis. In cultured chondrocytes, the inhibition of NF-κB p65 activation (by PDTC and BAY) and expression (by p65 siRNA) led to the same findings observed in cultured metatarsal bones. In contrast, overexpression of p65 in cultured chondrocytes induced chondrocyte proliferation and differentiation and prevented apoptosis. Although PDTC, BAY, and p65 siRNA reduced the expression of BMP-2 in cultured growth plate chondrocytes, the overexpression of p65 increased it. The addition of Noggin, a BMP-2 antagonist, neutralized the stimulatory effects of p65 on chondrocyte proliferation and differentiation, as well as its anti-apoptotic effect. In conclusion, our findings indicate that NF-κB p65 expressed in growth plate chondrocytes facilitates growth plate chondrogenesis and longitudinal bone growth by inducing BMP-2 expression and activity.

scholarly journals The Receptor-Dependent Actions of 1,25-Dihydroxyvitamin D Are Required for Normal Growth Plate Maturation in NPt2a Knockout Mice

Endocrinology ◽  
2010 ◽  
Vol 151 (10) ◽  
pp. 4607-4612 ◽  
Author(s):  
Susanne U. Miedlich ◽  
Eric D. Zhu ◽  
Yves Sabbagh ◽  
Marie B. Demay
Keyword(s):  
Vitamin D ◽  
Growth Plate ◽  
Fibroblast Growth Factor 23 ◽  
Normal Growth ◽  
Chondrocyte Apoptosis ◽  
Apoptotic Pathway ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Hypertrophic Chondrocyte

Rickets is a growth plate abnormality observed in growing animals and humans. Rachitic expansion of the hypertrophic chondrocyte layer of the growth plate, in the setting of hypophosphatemia, is due to impaired apoptosis of these cells. Rickets is observed in humans and mice with X-linked hypophosphatemia that is associated with renal phosphate wasting secondary to elevated levels of fibroblast growth factor-23. Rickets is also seen in settings of impaired vitamin D action, due to elevated PTH levels that increase renal phosphate excretion. However, mice with hypophosphatemia secondary to ablation of the renal sodium-dependent phosphate transport protein 2a (Npt2a), have not been reported to develop rickets. Because activation of the mitochondrial apoptotic pathway by phosphate is required for hypertrophic chondrocyte apoptosis in vivo, investigations were undertaken to address this paradox. Analyses of the Npt2a null growth plate demonstrate expansion of the hypertrophic chondrocyte layer at 2 wk of age, with resolution of this abnormality by 5 wk of age. This is temporally associated with an increase in circulating levels of 1,25-dihydroxyvitamin D. To address whether the receptor-dependent actions of this steroid hormone are required for normalization of the growth plate phenotype, the Npt2a null mice were mated with mice lacking the vitamin D receptor or were rendered vitamin D deficient. These studies demonstrate that the receptor-dependent actions of 1,25-dihydroxyvitamin D are required for maintenance of a normal growth plate phenotype in the Npt2a null mice.

scholarly journals DHEA Suppresses Longitudinal Bone Growth by Acting Directly at Growth Plate through Estrogen Receptors

Endocrinology ◽  
2011 ◽  
Vol 152 (4) ◽  
pp. 1423-1433 ◽  
Author(s):  
Hongzhi Sun ◽  
Weijin Zang ◽  
Bo Zhou ◽  
Lin Xu ◽  
Shufang Wu
Keyword(s):  
Estrogen Receptor ◽  
Growth Plate ◽  
Bone Growth ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Skeletal Maturation ◽  
Chondrocyte Apoptosis ◽  
Chondrocyte Proliferation ◽  
Longitudinal Bone Growth ◽  
Growth Plate Chondrocyte

Abstract Dehydroepiandrosterone (DHEA) is produced by the adrenal cortex and is the most abundant steroid in humans. Although in some physiological and pathological conditions the increased secretion of DHEA and its sulfated form is associated with accelerated growth rate and skeletal maturation, it is unclear whether DHEA can affect longitudinal bone growth and skeletal maturation by acting directly at the growth plate. In our study, DHEA suppressed metatarsal growth, growth plate chondrocyte proliferation, and hypertrophy/differentiation. In addition, DHEA increased the number of apoptotic chondrocytes in the growth plate. In cultured chondrocytes, DHEA reduced chondrocyte proliferation and induced apoptosis. The DHEA-induced inhibition of metatarsal growth and growth plate chondrocyte proliferation and hypertrophy/differentiation was nullified by culturing metatarsals with DHEA in the presence of ICI 182,780, an inhibitor of estrogen receptor, but not in the presence of Casodex, an inhibitor of androgen receptor. Lastly, nuclear factor-κB DNA binding activity was inhibited by the addition of DHEA in the medium of cultured chondrocyte. Our findings indicate that DHEA suppressed bone growth by acting directly at growth plate through estrogen receptor. Such growth inhibition is mediated by decreased chondrocyte proliferation and hypertrophy/differentiation and by increased chondrocyte apoptosis.

scholarly journals Surgical Treatment of Fibroosseous Lesion in Young Patient with Reduced Mouth Opening

2018 ◽  
Vol 11 (4) ◽  
pp. 314-319
Author(s):  
PedroHenrique de Azambuja Carvalho ◽  
Marcos Antonio Torriani ◽  
LetíciaKirst Post ◽  
OtacílioLuiz Chagas
Keyword(s):  
Surgical Treatment ◽  
Fibrous Dysplasia ◽  
Inflammatory Process ◽  
Bone Growth ◽  
Mouth Opening ◽  
Incisional Biopsy ◽  
Mandibular Ramus ◽  
And Function

Fibrous dysplasia is a benign fibroosseous disorder that can affect the maxillary bones, causing aesthetic deformity and functional impairment. This article reports the case of a 13-year-old male patient at the time of diagnosis. The patient showed increased facial volume with relevant asymmetry, having reported the onset of the condition 12 months before. Upon examination, the patient presented an 8-mm mouth opening and an acute inflammatory process associated with tooth 37 pericoronal hood. Upon imaging exam, exuberant bone growth in the left mandibular ramus area of ground glass aspect was observed. After incisional biopsy, fibrous dysplasia was diagnosed and sequentially treated with osteoplasty and coronoid process removal. The patient evolved to a 43-mm mouth opening and favorable aesthetics without recurrence in a 3-year follow-up period. In this case, coronoidectomy and bone plasty proved to be effective, returning aesthetics and function. The patient is supposed to be followed up in the long term.

scholarly journals Raf Kinases Are Essential for Phosphate Induction of ERK1/2 Phosphorylation in Hypertrophic Chondrocytes and Normal Endochondral Bone Development

2017 ◽  
Vol 292 (8) ◽  
pp. 3164-3171 ◽  
Author(s):  
Garyfallia Papaioannou ◽  
Elizabeth T. Petit ◽  
Eva S. Liu ◽  
Manuela Baccarini ◽  
Catrin Pritchard ◽  
...  
Keyword(s):  
Growth Plate ◽  
Vascular Invasion ◽  
Bone Development ◽  
Skeletal Development ◽  
Hypertrophic Chondrocytes ◽  
Chondrocyte Apoptosis ◽  
Caspase 9 ◽  
Endochondral Bone ◽  
Hypertrophic Chondrocyte

Hypophosphatemia causes rickets by impairing hypertrophic chondrocyte apoptosis. Phosphate induction of MEK1/2-ERK1/2 phosphorylation in hypertrophic chondrocytes is required for phosphate-mediated apoptosis and growth plate maturation. MEK1/2 can be activated by numerous molecules including Raf isoforms. A- and B-Raf ablation in chondrocytes does not alter skeletal development, whereas ablation of C-Raf decreases hypertrophic chondrocyte apoptosis and impairs vascularization of the growth plate. However, ablation of C-Raf does not impair phosphate-induced ERK1/2 phosphorylation in vitro, but leads to rickets by decreasing VEGF protein stability. To determine whether Raf isoforms are required for phosphate-induced hypertrophic chondrocyte apoptosis, mice lacking all three Raf isoforms in chondrocytes were generated. Raf deletion caused neonatal death and a significant expansion of the hypertrophic chondrocyte layer of the growth plate, accompanied by decreased cleaved caspase-9. This was associated with decreased phospho-ERK1/2 immunoreactivity in the hypertrophic chondrocyte layer and impaired vascular invasion. These data further demonstrated that Raf kinases are required for phosphate-induced ERK1/2 phosphorylation in cultured hypertrophic chondrocytes and perform essential, but partially redundant roles in growth plate maturation.

scholarly journals Proepithelin Stimulates Growth Plate Chondrogenesis via Nuclear Factor-κB-p65-dependent Mechanisms

2011 ◽  
Vol 286 (27) ◽  
pp. 24057-24067 ◽  
Author(s):  
Shufang Wu ◽  
Weijin Zang ◽  
Xu Li ◽  
Hongzhi Sun
Keyword(s):  
Cell Proliferation ◽  
Growth Plate ◽  
Bone Growth ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Pyrrolidine Dithiocarbamate ◽  
Growth Plate Chondrocytes ◽  
Cell Proliferation And Differentiation ◽  
Rat Growth ◽  
And Function

Proepithelin, a previously unrecognized growth factor in cartilage, has recently emerged as an important regulator for cartilage formation and function. In the present study, we provide several lines of evidences in proepithelin-mediated induction of cell proliferation, differentiation, and apoptosis in the metatarsal growth plate. Proepithelin-mediated stimulation of metatarsal growth and growth plate chondrogenesis was neutralized by pyrrolidine dithiocarbamate, a known NF-κB inhibitor. In rat growth plate chondrocytes, proepithelin induced NF-κB-p65 nuclear translocation, and nuclear NF-κB-p65 initiated its target gene cyclin D1 to regulate chondrocyte functions. The inhibition of NF-κB-p65 expression and activity (by p65 short interfering RNA (siRNA) and pyrrolidine dithiocarbamate, respectively) in chondrocytes reversed the proepithelin-mediated induction of cell proliferation and differentiation and the proepithelin-mediated prevention of cell apoptosis. Moreover, the inhibition of the phosphatidylinositol 3-kinase and Akt abolished the effects of proepithelin on NF-κB activation. Finally, using siRNA and antisense strategies, we demonstrated that endogenously produced proepithelin by chondrocytes is important for chondrocyte growth in serum-deprived conditions. These results support the hypothesis that the induction of NF-κB activity of in growth plate chondrocytes is critical in proepithelin-mediated growth plate chondrogenesis and longitudinal bone growth.

Distraction Osteogenesis in the Treatment of Craniofacial Anomalies: Applications and Outcomes

2020 ◽  
Vol 5 (6) ◽  
pp. 1469-1481 ◽  
Author(s):  
Joseph A. Napoli ◽  
Carrie E. Zimmerman ◽  
Linda D. Vallino
Keyword(s):  
Distraction Osteogenesis ◽  
Bone Growth ◽  
Upper Airway ◽  
Craniofacial Anomalies ◽  
Craniofacial Skeleton ◽  
Facial Skeleton ◽  
Psychosocial Impairment ◽  
And Function ◽  
Correct Structure

Purpose Craniofacial anomalies (CFA) often result in growth abnormalities of the facial skeleton adversely affecting function and appearance. The functional problems caused by the structural anomalies include upper airway obstruction, speech abnormalities, feeding difficulty, hearing deficits, dental/occlusal defects, and cognitive and psychosocial impairment. Managing disorders of the craniofacial skeleton has been improved by the technique known as distraction osteogenesis (DO). In DO, new bone growth is stimulated allowing bones to be lengthened without need for bone graft. The purpose of this clinical focus article is to describe the technique and clinical applications and outcomes of DO in CFA. Conclusion Distraction can be applied to various regions of the craniofacial skeleton to correct structure and function. The benefits of this procedure include improved airway, feeding, occlusion, speech, and appearance, resulting in a better quality of life for patients with CFA.

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