IU Indianapolis ScholarWorks :: Browsing by Subject "Osteoblasts"

Browsing by Subject "Osteoblasts"

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Altered Caveolin-1 Dynamics Result in Divergent Mineralization Responses in Bone and Vascular Calcification
(Springer, 2023-08-19) Bakhshian Nik, Amirala; Kaiser, Katherine; Sun, Patrick; Khomtchouk, Bohdan B.; Hutcheson, Joshua D.; Biomedical Engineering and Informatics, Luddy School of Informatics, Computing, and Engineering
Introduction: Though vascular smooth muscle cells adopt an osteogenic phenotype during pathological vascular calcification, clinical studies note an inverse correlation between bone mineral density and arterial mineral-also known as the calcification paradox. Both processes are mediated by extracellular vesicles (EVs) that sequester calcium and phosphate. Calcifying EV formation in the vasculature requires caveolin-1 (CAV1), a membrane scaffolding protein that resides in membrane invaginations (caveolae). Of note, caveolin-1-deficient mice, however, have increased bone mineral density. We hypothesized that caveolin-1 may play divergent roles in calcifying EV formation from vascular smooth muscle cells (VSMCs) and osteoblasts (HOBs). Methods: Primary human coronary artery VSMCs and osteoblasts were cultured for up to 28 days in an osteogenic media. CAV1 expression was knocked down using siRNA. Methyl β-cyclodextrin (MβCD) and a calpain inhibitor were used, respectively, to disrupt and stabilize the caveolar domains in VSMCs and HOBs. Results: CAV1 genetic variation demonstrates significant inverse relationships between bone-mineral density (BMD) and coronary artery calcification (CAC) across two independent epidemiological cohorts. Culture in osteogenic (OS) media increased calcification in HOBs and VSMCs. siRNA knockdown of CAV1 abrogated VSMC calcification with no effect on osteoblast mineralization. MβCD-mediated caveolae disruption led to a 3-fold increase of calcification in VSMCs treated with osteogenic media (p < 0.05) but hindered osteoblast mineralization (p < 0.01). Conversely, stabilizing caveolae by calpain inhibition prevented VSMC calcification (p < 0.05) without affecting osteoblast mineralization. There was no significant difference in CAV1 content between lipid domains from HOBs cultured in OS and control media. Conclusion: Our data indicate fundamental cellular-level differences in physiological and pathophysiological mineralization mediated by CAV1 dynamics. This is the first study to suggest that divergent mechanisms in calcifying EV formation may play a role in the calcification paradox. Supplementary information: The online version contains supplementary material available at 10.1007/s12195-023-00779-7.
Aplidin (plitidepsin) is a novel anti-myeloma agent with potent anti-resorptive activity mediated by direct effects on osteoclasts
(Impact Journals, 2019-04-12) Delgado-Calle, Jesus; Kurihara, Noriyoshi; Atkinson, Emily G.; Nelson, Jessica; Miyagawa, Kazuaki; Galmarini, Carlos Maria; Roodman, G. David; Bellido, Teresita; Medicine, School of Medicine
Despite recent progress in its treatment, Multiple Myeloma (MM) remains incurable and its associated bone disease persists even after complete remission. Thus, identification of new therapeutic agents that simultaneously suppress MM growth and protect bone is an unmet need. Herein, we examined the effects of Aplidin, a novel anti-cancer marine-derived compound, on MM and bone cells. In vitro, Aplidin potently inhibited MM cell growth and induced apoptosis, effects that were enhanced by dexamethasone (Dex) and bortezomib (Btz). Aplidin modestly reduced osteocyte/osteoblast viability and decreased osteoblast mineralization, effects that were enhanced by Dex and partially prevented by Btz. Further, Aplidin markedly decreased osteoclast precursor numbers and differentiation, and reduced mature osteoclast number and resorption activity. Moreover, Aplidin reduced Dex-induced osteoclast differentiation and further decreased osteoclast number when combined with Btz. Lastly, Aplidin alone, or suboptimal doses of Aplidin combined with Dex or Btz, decreased tumor growth and bone resorption in ex vivo bone organ cultures that reproduce the 3D-organization and the cellular diversity of the MM/bone marrow niche. These results demonstrate that Aplidin has potent anti-myeloma and anti-resorptive properties, and enhances proteasome inhibitors blockade of MM growth and bone destruction.
BENS, a novel regulator of bone/cartilage healing
(2013) Labban, Nawaf Yousef; Windsor, L. Jack; Song, Fengyu; Ghoneima, Ahmed; Bruzzaniti, Angela; Allen, Matthew R.; Cameron, Jo Ann
Enhancing osteoblast proliferation, survival, and extracellular matrix protein secretion are potential therapeutic approaches to treat bone fractures and diseases such as osteoporosis. BENS is a traditional medicine used in many countries such as India for thousands of years to treat many diseases including bone diseases. In this study, molecular, cell-based and in vivo approaches were utilized to investigate the effects of BENS on bone and cartilage regeneration. An osteosarcoma cell line (MG63) was incubated in serum free media with and without 0.8 mg/ml of BENS. BENS significantly increased cell survival up to 30 days and these cells retained their ability to proliferate in fresh media with serum. After adding BENS, there were statistically significant decreases in the expression of both anti-apoptotic and pro-apoptotic proteins. An in vivo non-critical size segmental bone defect Xenopus system was used to evaluate the ability of BENS to enhance cartilage formation. After a small segment of the anterior hemisection of the tarsus bone was excised, the frogs were divided into three groups and given subcutaneous injections of either phosphate-buffered saline or BENS once daily for 30 days and then bone/cartilage formation evaluated. The total cartilage area/total section area was significantly increased (2.6 fold) in the BENS treated samples. In an osteoporotic rat model, the anabolic properties of BENS on bone mass were assessed by histomorphometric analyses. Ovariectomized (OVX) rats received daily intraperitoneal injections for 4 weeks. Bone formation rates (BFRs) for the cortical periosteal bone surface of the midshaft tibia were 383.2, 223.9, 308.8, 304.9, and 370.9 µm3/µm2/year, and for the trabecular surface were 82.2, 113, 212.1, 157, and 165 µm3/µm2/year for the sham, OVX, PTH, 3 mg/kg BENS, and 30 mg/kg BENS groups, respectively. BENS increased both trabecular and cortical BFRs. It generated better results on cortical periosteal bone surface than did PTH. Taken together, these findings suggest that BENS promotes osteoblast survival due to its effects on altering the balance between pro-apoptotic and anti-apoptotic proteins. In addition, in vivo studies revealed that BENS enhanced cartilage formation in Xenopus and BFRs in rats. Therefore, BENS may possess anabolic bone/cartilage properties.
Bidirectional Notch signaling and osteocyte-derived factors in the bone marrow microenvironment promote tumor cell proliferation and bone destruction in multiple myeloma
(American Association for Cancer Research, 2016-03-01) Delgado-Calle, Jesus; Anderson, Judith; Cregor, Meloney D.; Hiasa, Masahiro; Chirgwin, John M.; Carlesso, Nadia; Yoneda, Toshiyuki; Mohammad, Khalid S.; Plotkin, Lilian I.; Roodman, G. David; Bellido, Teresita; Department of Anatomy & Cell Biology, IU School of Medicine
In multiple myeloma, an overabundance of monoclonal plasma cells in the bone marrow induces localized osteolytic lesions that rarely heal due to increased bone resorption and suppressed bone formation. Matrix-embedded osteocytes comprise more than 95% of bone cells and are major regulators of osteoclast and osteoblast activity, but their contribution to multiple myeloma growth and bone disease is unknown. Here, we report that osteocytes in a mouse model of human MM physically interact with multiple myeloma cells in vivo, undergo caspase-3-dependent apoptosis, and express higher RANKL (TNFSF11) and sclerostin levels than osteocytes in control mice. Mechanistic studies revealed that osteocyte apoptosis was initiated by multiple myeloma cell-mediated activation of Notch signaling and was further amplified by multiple myeloma cell-secreted TNF. The induction of apoptosis increased osteocytic Rankl expression, the osteocytic Rankl/Opg (TNFRSF11B) ratio, and the ability of osteocytes to attract osteoclast precursors to induce local bone resorption. Furthermore, osteocytes in contact with multiple myeloma cells expressed high levels of Sost/sclerostin, leading to a reduction in Wnt signaling and subsequent inhibition of osteoblast differentiation. Importantly, direct contact between osteocytes and multiple myeloma cells reciprocally activated Notch signaling and increased Notch receptor expression, particularly Notch3 and 4, stimulating multiple myeloma cell growth. These studies reveal a previously unknown role for bidirectional Notch signaling that enhances MM growth and bone disease, suggesting that targeting osteocyte-multiple myeloma cell interactions through specific Notch receptor blockade may represent a promising treatment strategy in multiple myeloma.
C-Mpl Is Expressed on Osteoblasts and Osteoclasts and Is Important in Regulating Skeletal Homeostasis
(Wiley, 2016-04) Meijome, Tomas E.; Baughman, Jenna T.; Hooker, R. Adam; Cheng, Ying-Hua; Ciovacco, Wendy A.; Balamohan, Sanjeev M.; Srinivasan, Trishya L.; Chitteti, Brahmananda R.; Eleniste, Pierre P.; Horowitz, Mark C.; Srour, Edward F.; Bruzzaniti, Angela; Fuchs, Robyn K.; Kacena, Melissa A.; Orthopaedic Surgery, School of Medicine
C-Mpl is the receptor for thrombopoietin (TPO), the main megakaryocyte (MK) growth factor, and c-Mpl is believed to be expressed on cells of the hematopoietic lineage. As MKs have been shown to enhance bone formation, it may be expected that mice in which c-Mpl was globally knocked out (c-Mpl(-/-) mice) would have decreased bone mass because they have fewer MKs. Instead, c-Mpl(-/-) mice have a higher bone mass than WT controls. Using c-Mpl(-/-) mice we investigated the basis for this discrepancy and discovered that c-Mpl is expressed on both osteoblasts (OBs) and osteoclasts (OCs), an unexpected finding that prompted us to examine further how c-Mpl regulates bone. Static and dynamic bone histomorphometry parameters suggest that c-Mpl deficiency results in a net gain in bone volume with increases in OBs and OCs. In vitro, a higher percentage of c-Mpl(-/-) OBs were in active phases of the cell cycle, leading to an increased number of OBs. No difference in OB differentiation was observed in vitro as examined by real-time PCR and functional assays. In co-culture systems, which allow for the interaction between OBs and OC progenitors, c-Mpl(-/-) OBs enhanced osteoclastogenesis. Two of the major signaling pathways by which OBs regulate osteoclastogenesis, MCSF/OPG/RANKL and EphrinB2-EphB2/B4, were unaffected in c-Mpl(-/-) OBs. These data provide new findings for the role of MKs and c-Mpl expression in bone and may provide insight into the homeostatic regulation of bone mass as well as bone loss diseases such as osteoporosis.
Cell Kinetic Analysis of Osteoblast Histogenesis in the Rat Mandibular Condyle Following Exposure to Hard and Soft Diets
(1991) Stenftenagel, Brenda Kay; Roberts, W. Eugene; Shanks, James C.; Garetto, Lawrence P.; Hohlt, William H.; Schaaf, Jack E.
Microgravity of spaceflight has been associated with inhibition of bone formation, decreased number of osteoblasts (Ob), and suppression of Ob histogenesis. This study was designed to study Ob histogenesis, i.e., the proliferation and differentiation of cells producing Ob. Inhibition of Ob formation seems to be a principal factor in osteopenia induced by spaceflight. Osteoblast histogenesis is a stress/strain mediated mechanism and appears to be gravity dependent under certain conditions. On Spacelab-3 (SL-3), the rat mandibular condyle was evaluated as a model for space study. Data indicated an increase in A+ A' cells (noncommitted and committed self-perpetuating precursor cells), and a decrease in C + D type cells (preosteoblasts that are in the G1 or G2 stage of the cell cycle), accompanied by a decrease in Obs. A stress/strain mediated increase in nuclear volume (A'=> C) is an important rate-limiting step in Ob differentiation. It is hypothesized that this step is inhibited in microgravity. Additional ground studies are needed to confirm these data and define the mechanism of action. Studies have shown that a soft diet decreases overall mechanical loading of the masticatory apparatus. A soft diet was used in this study to simulate the potential microgravity-like effects of decreased mechanical loading on the mandibular condyle, i.e., a decreased masticatory force was used as a model for microgravity. Eighteen male, Sprague-Dawley rats (six to eight weeks of age) were divided into three groups: 1) the experimental group maintained on a soft paste diet; 2) a control group, pair fed equal amounts of food as the experimental group; and 3) a control group fed ad libitum. Both control groups were fed standard Purina TM Rat Chow (sPRC) pellets. The experimental diet consisted of sPRC, crushed and mixed with sufficient water to form a paste. After two weeks on their respective diets, each animal was injected i.p. with xylenol orange, a bone label. One week later calcein green was administered similarly. Two days after the last label, animals were injected i.p. with 3H-thymidine at 8 a.m. One hour later each animal was anesthesized with ketamine and decapitated. Mandibles were fixed for 72 hours. Nuclear morphometry and labeling index data were collected from autoradiographs prepared from demineralized sections. Due to technique problems, only three paste group condyles and five condyles from each of the control groups could be examined. Results showed no significant differences at p < 0.05 in labeling index. Nuclear morphometry data indicated a significant difference in L, A+ A', C, and C + D cells. Rats fed a paste diet had on the average 12 percent more type A+ A' cells, and 17-25 percent less C + D combined cells than the two control groups. These data indicate a similar shift in Ob histogenesis to the left (more A + A' cells) as that found in the POL and the condyle of rats flown in space. These findings support the hypothesis that osteopenia induced in spaceflight may be the result of a reduction in a local mechanical component, or a lack of anti-gravity posturing. Therefore, it may be concluded that a soft paste diet mimics microgravity by decreasing mechanical loading and inhibiting the stress/strain mediated increase in nuclear volume (A'=> C). The condyle from rats fed a soft diet may be a valuable model for studying osteopenia.
Cell Kinetic Analysis of Osteoblast Histogenesis in the Rat Periodontal Ligament Following Exposure to Hard and Soft Diet
(1991) Colter, Robert D.; Roberts, W. Eugene; Garetto, Lawrence P.; Hohlt, William F.; Newell, Donald; Shanks, James C.
This is the first in a series of experiments designed to investigate the effect of local and systemic factors on osteoblast histogenesis in rats. A soft diet is an experimental means thought to decrease the overall mechanical loading (a local factor) on the masticatory apparatus. Eighteen Sprague-Dawley rats were divided into three equally sized groups: 1) an experimental group, which was maintained on a soft paste diet; 2) a control group, pair fed with the experimental group; and 3) a control group fed ad libitum. Both control groups continued to eat standard Purina rat chow pellets. Twenty-three days later all animals were injected subcutaneously with 1.0 μCi/ g tritiated thymidine and sacrificed one hour later. The maxillae of the animals were dissected and sectioned. The periodontal ligament (PDL) of the mesial surface of the mesial root of the first molar was analyzed microscopically 110 μm above and below the mid root area. Nuclear size was used to determine the stage of osteoblast differentiation. The labeling index was used to determine the proliferative activity of the cells. The distance of cells from the nearest major blood vessel (NMBV) was measured and the cells were grouped into one to four extravascular zones. For each zone, cell density was determined. PDL widths were measured to evaluate tooth function. If osteogenesis is due primarily to stress and strain on bones, then rats maintained on the soft diet should show a decreased labeling index, increased number of A and A' cells, decreased number of C and D cells, and an unaltered vascularly-oriented cell density gradient. The number of osteoblastic precursor cells (A and A' cells) close to blood vessels should increase relative to the number of preosteoblastic cells (C and D) further from the vessels. Also, the width of the PDL space in the soft diet rats should be narrower since their function was decreased. The results of this study did not support the hypothesis that a decrease in masticatory stress and strain within the rat periodontal ligament due to softened dietary consistency reduces osteoblast histogenesis. No differences were seen in the PDL widths or the vascularly-oriented cell density gradient between groups. High levels of A+A' cells were seen paravascularly for all groups, and their relative numbers decreased as one moved away from the blood vessel into a lower cell density area, supporting previous studies. No differences were seen in the fractional distribution of A+A' cells or C+D cells between groups, as was hypothesized, except for a higher level of A+A' cells in the pair fed group across all zones. This latter finding was probably due to physiologic variation and the small sample sizes used in this study. Decreased masticatory stress and strain due to a softened diet did not reduce osteoblast histogenesis. Further research needs to investigate systemic factors which may influence bone formation.
Cellular components of the hematopoietic niche and their regulation of hematopoietic stem cell function
(Wolters Kluwer, 2021) Ghosh, Joydeep; El Koussa, Roy; Mohamad, Safa F.; Liu, Jianyun; Kacena, Melissa A.; Srour, Edward F.; Medicine, School of Medicine
Purpose of review: Development and functions of hematopoietic stem cells (HSC) are regulated by multiple cellular components of the hematopoietic niche. Here we review the recent advances in studying the role of three such components -- osteoblasts, osteomacs, and megakaryocytes and how they interact with each other in the hematopoietic niche to regulate HSC. Recent findings: Recent advances in transgenic mice models, scRNA-seq, transcriptome profile, proteomics, and live animal imaging have revealed the location of HSC within the bone and signaling molecules required for the maintenance of the niche. Interaction between megakaryocytes, osteoblasts and osteomacs enhances hematopoietic stem and progenitor cells (HSPC) function. Studies also revealed the niche as a dynamic entity that undergoes cellular and molecular changes in response to stress. Aging, which results in reduced HSC function, is associated with a decrease in endosteal niches and osteomacs as well as reduced HSC--megakaryocyte interactions. Summary: Novel approaches to study the cellular components of the niche and their interactions to regulate HSC development and functions provided key insights about molecules involved in the maintenance of the hematopoietic system. Furthermore, these studies began to build a more comprehensive model of cellular interactions and dynamics in the hematopoietic niche.
Development of an Artificial Finger-Like Knee Loading Device to Promote Bone Health
(Scientific Research Publishing, 2017-11) Korupolu, Sandeep; Chien, Stanley; Yokota, Hiroki; Anwar, Sohel; Mechanical and Energy Engineering, School of Engineering and Technology
This study presents the development of an innovative artificial finger-like device that provides position specific mechanical loads at the end of the long bone and induces mechanotransduction in bone. Bone cells such as osteoblasts are the mechanosensitive cells that regulate bone remodelling. When they receive gentle, periodic mechanical loads, new bone formation is promoted. The proposed device is an under-actuated multi-fingered artificial hand with 4 fingers, each having two phalanges. These fingers are connected by mechanical linkages and operated by a worm gearing mechanism. With the help of 3D printing technology, a prototype device was built mostly using plastic materials. The experimental validation results show that the device is capable of generating necessary forces at the desired frequencies, which are suitable for the stimulation of bone cells and the promotion of bone formation. It is recommended that the device be tested in a clinical study for confirming its safety and efficacy with patients.
Differentiation and Activity of Murine Derived Stromal Osteoblasts After Electromagnetic Wave Stimulation
(2022) Wu, Jennifer L.; Spolnik, Kenneth; Bruzzaniti, Angela; Ehrlich, Ygal; Warner, Ned
Introduction: Elimination of bacteria and active infection within an infected root canal system is one of the primary objectives of nonsurgical root canal treatment. One of the measures of successful root canal treatment is subsequent bone healing of periapical lesions caused by previous infection. A previous study by Yumoto et al. showed that electromagnetic wave stimulation can increase proliferation of osteoblastic cells with no cytotoxicity, and it can also up-regulate growth factors such as vascular endothelial growth factor and platelet-derived growth factor.18 They also showed increased proliferation of an immortalized osteoblastic MC3T3-E1 cell line 3 days following electromagnetic stimulation (EMS).18 Previously, Pauly et al. found increased alkaline phosphatase (ALP) activity with 10 mA EMS application to primary murine calvaria-derived osteoblastic cells with 5 pulses at 1 second per pulse, but no significant differences were found for MTS proliferation nor mineral deposition compared to a negative control group.82 Optimization of the different variables including post-treatment incubation time, current delivery, and number of pulses per treatment may be necessary to improve osteogenic activity. The use of mesenchymal stem cells from murine bone marrow may also offer a physiologically relevant model for osteoblastic regeneration of periapical lesions. Objectives: The goal of this study was to investigate and optimize the effects of electromagnetic wave stimulation (EMS) on murine bone marrow mesenchymal stem cells (MSCs) by evaluating the proliferation and differentiation of the cells after exposure to different EMS treatment regimens. Materials and Methods: 5 x104 stromal osteoblasts (SOBs) were cultured in 24-well plates in α-MEM containing 10% fetal bovine serum. Cells were then subjected to pulsed EMS treatments of 1 mA, 10 mA, and 50 mA. EMS was generated using an electromagnetic apical treatment (EMAT) device created by J. Morita MFG Corp. Proliferation was assessed via MTS assay 1 days after treatment. For osteogenic differentiation, ascorbic acid and β-glycerol phosphate were added to the culture media, and SOBs were cultured for 14 days. Afterwards, alkaline phosphatase (ALP) activity and Alizarin-red S mineral deposition were quantified as measures of osteoblast activity. Cells grown in osteogenic media without EMS treatment served as the negative control. Results: Although MSC proliferation was unaffected by different EMS treatment regimens, 50 mA EMS resulted in a decrease in ALP activity and mineral deposition by osteoblasts. Conclusions: Our findings suggest bone healing by EMS may involve a different cellular mechanism, that is not reproduced in vitro in our studies. Utilizing different amperage and EMS regimens may improve osteogenic differentiation.

Browsing by Subject "Osteoblasts"

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