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Deng J, Van Duyn C, Cohen DJ, Schwartz Z, Boyan BD. Strategies for Improving Impaired Osseointegration in Compromised Animal Models. J Dent Res 2024; 103:467-476. [PMID: 38616679 PMCID: PMC11055505 DOI: 10.1177/00220345241231777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024] Open
Abstract
Implant osseointegration is reduced in patients with systemic conditions that compromise bone quality, such as osteoporosis, disuse syndrome, and type 2 diabetes. Studies using rodent models designed to mimic these compromised conditions demonstrated reduced bone-to-implant contact (BIC) or a decline in bone mineral density. These adverse effects are a consequence of disrupted intercellular communication. A variety of approaches have been developed to compensate for the altered microenvironment inherent in compromised conditions, including the use of biologics and implant surface modification. Chemical and physical modification of surface properties at the microscale, mesoscale, and nanoscale levels to closely resemble the surface topography of osteoclast resorption pits found in bone has proven to be a highly effective strategy for improving implant osseointegration. The addition of hydrophilicity to the surface further enhances osteoblast response at the bone-implant interface. These surface modifications, applied either alone or in combination, improve osseointegration by increasing proliferation and osteoblastic differentiation of osteoprogenitor cells and enhancing angiogenesis while modulating osteoclast activity to achieve net new bone formation, although the specific effects vary with surface treatment. In addition to direct effects on surface-attached cells, the communication between bone marrow stromal cells and immunomodulatory cells is sensitive to these surface properties. This article reports on the advances in titanium surface modifications, alone and in combination with novel therapeutics in animal models of human disease affecting bone quality. It offers clinically translatable perspectives for clinicians to consider when using different surface modification strategies to improve long-term implant performance in compromised patients. This review supports the use of surface modifications, bioactive coatings, and localized therapeutics as pragmatic approaches to improve BIC and enhance osteogenic activity from both structural and molecular standpoints.
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Affiliation(s)
- J. Deng
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - C. Van Duyn
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - D. J. Cohen
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Z. Schwartz
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
- Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - B. D. Boyan
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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2
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Schwartz Z, Kurtyka D, Trufant J. Management of High-Risk Cutaneous Squamous Cell Carcinomas Among Mohs Surgeons. Dermatol Surg 2024:00042728-990000000-00739. [PMID: 38530992 DOI: 10.1097/dss.0000000000004162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Affiliation(s)
- Ziv Schwartz
- All authors are affiliated with the Department of Dermatology and Cutaneous Biology, Thomas Jefferson University Hospital, Sidney Kimmel Medical College, Philadelphia, Pennsylvania
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3
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Schwartz Z, Mashkevich G, Zeltser R. Repair of a Defect Spanning the Nasal Sill, Vestibule, and Columellar Septum. Dermatol Surg 2024:00042728-990000000-00651. [PMID: 38265887 DOI: 10.1097/dss.0000000000004087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Affiliation(s)
- Ziv Schwartz
- Sidney Kimmel College of Medicine at TJUH/Jefferson Health, Philadelphia, Pennsylvania
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Affiliation(s)
- Jason B Lee
- Thomas Jefferson University, Philadelphia, PA
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5
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Yue C, Cao J, Wong A, Kim JH, Alam S, Luong G, Talegaonkar S, Schwartz Z, Boyan BD, Giannobile WV, Sahingur SE, Lin Z. Human Bone Marrow Stromal Cell Exosomes Ameliorate Periodontitis. J Dent Res 2022; 101:1110-1118. [PMID: 35356822 PMCID: PMC9305845 DOI: 10.1177/00220345221084975] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human bone marrow stromal cell (hBMSC)-derived exosomes are promising therapeutics for inflammatory diseases due to their unique microRNA (miRNA) and protein cargos. Periodontal diseases often present with chronicity and corresponding exuberant inflammation, which leads to loss of tooth support. In this study, we explored whether hBMSC exosomes can affect periodontitis progression. hBMSC exosomes were isolated from cell culture medium through sequential ultracentrifugation. miRNAs and proteins that were enriched in hBMSC exosomes were characterized by RNA sequencing and protein array, respectively. hBMSC exosomes significantly suppressed periodontal keystone pathogen Porphyromonas gingivalis-triggered inflammatory response in macrophages in vitro. Transcriptomic analysis suggested that exosomes exerted their effects through regulating cell metabolism, differentiation, and inflammation resolution. In vivo, weekly exosome injection into the gingival tissues reduced the tissue destruction and immune cell infiltration in rat ligature-induced periodontitis model. Collectively, these findings suggest that hBMSC-derived exosomes can potentially be used as a host modulation agent in the management of periodontitis.
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Affiliation(s)
- C Yue
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - J Cao
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA.,Department of Periodontology, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Beijing, People's Republic of China
| | - A Wong
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - J H Kim
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - S Alam
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - G Luong
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - S Talegaonkar
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Z Schwartz
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - B D Boyan
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - W V Giannobile
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - S E Sahingur
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, PA, USA
| | - Z Lin
- Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
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Scott KM, Cohen DJ, Hays M, Nielson DW, Grinstaff MW, Lawson TB, Snyder BD, Boyan BD, Schwartz Z. Regulation of inflammatory and catabolic responses to IL-1β in rat articular chondrocytes by microRNAs miR-122 and miR-451. Osteoarthritis Cartilage 2021; 29:113-123. [PMID: 33161100 DOI: 10.1016/j.joca.2020.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/30/2020] [Accepted: 09/14/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE miR-122 stimulates proliferation of growth plate chondrocytes whereas miR-451 stimulates terminal differentiation and matrix turnover. Here, we examined the potential of these microRNA as regulators of articular chondrocytes using an in vitro model of osteoarthritis. METHODS miR-122 and miR-451 presence in rat articular cartilage was assessed using the anterior cruciate ligament transection model of OA. In vitro testing used first passage rat articular chondrocytes (rArCs) that were transfected with lipofectamine (Lipo) and miR-122 or miR-451 for 24-h, then treated with 10 ng/mL IL-1β in order to mimic an osteoarthritic environment. Conditioned media were collected and MMP13, PGE2 and OA-related cytokines were measured. Matrix vesicles were collected from cell layer lysates using ultra-centrifugation. Cells were treated with miR-122 or miR-451 inhibitors to verify miR-specific effects. RESULTS Both miR-122 and miR-451 were increased in the OA articular cartilage compared to healthy tissue; rArCs expressed both microRNAs in MVs. miR-122 prevented IL-1β-dependent increases in MMP-13 and PGE2, whereas miR-451 significantly increased the IL-1β effect. Multiplex data indicated that miR-122 reduced the stimulatory effect of IL-1β on IL-1α, IL-2, Il-4, IL-6, GM-CSF, MIP-1A, RANTES and VEGF. In contrast, IL-2, IL-4, IL-6, GM-CSF, and MIP-1A were increased by miR-451 while VEGF was decreased. Inhibiting miR-122 exacerbated the response to IL-1β indicating endogenous levels of miR-122 were present. There were no differences in MMP-13 or PGE2 with miR-451 Locked Nucleic Acid (LNA) inhibitor treatment. CONCLUSIONS Both miRs were elevated in OA in a rat bilateral anterior cruciate ligament transection (ACLT) model. miR-122 prevented, while miR-451 exacerbated the effects of IL-1β on rArCs.
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Affiliation(s)
- K M Scott
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA.
| | - D J Cohen
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA.
| | - M Hays
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA.
| | - D W Nielson
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA.
| | - M W Grinstaff
- Department of Biomedical Engineering and Chemistry, Boston University, Boston, MA, USA.
| | - T B Lawson
- Department of Biomedical Engineering and Chemistry, Boston University, Boston, MA, USA; Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston MA, USA.
| | - B D Snyder
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston MA, USA.
| | - B D Boyan
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Z Schwartz
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA; Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
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Schwartz Z, Bender A, Magro CM. Solitary congenital Langerhans cell histiocytoma: A pattern of benign, spontaneous regression in patients with single lesion disease. Pediatr Dermatol 2020; 37:1009-1013. [PMID: 32926467 DOI: 10.1111/pde.14333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 06/26/2020] [Accepted: 08/01/2020] [Indexed: 11/30/2022]
Abstract
Langerhans cell histiocytosis (LCH) is the neoplastic proliferation of dendritic langerin-positive histiocytes manifesting as either single system unifocal, single system multifocal, or multisystem disease. The designation Hashimoto-Pritzker, or self-healing LCH, has fallen out of favor since it is impossible to predict at time of diagnosis whether the disease is truly self-remitting or capable of spreading to other organ systems. We review the English literature on solitary congenital Langerhans cell histiocytoma, draw novel conclusions from the data provided by 81 cases in the literature, and illustrate a typical presentation of the diagnosis with a previously unreported patient. Each of the patients diagnosed with solitary congenital histiocytoma experienced spontaneous resolution and had no signs of systemic disease at latest follow-up. Furthermore, we offer an analysis of the histopathological findings available from the 81 cases and our patient. Based on our study observations, we propose solitary congenital Langerhans cell histiocytoma may portend a good prognosis and represent a distinct entity. However, until further confirmation with prospective studies, we recommend clinicians continue conducting appropriate workup to rule out systemic involvement.
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Affiliation(s)
- Ziv Schwartz
- Weill Cornell Medicine Department of Dermatology, New York, NY, USA.,SUNY Downstate College of Medicine, Brooklyn, NY, USA
| | - Anna Bender
- Weill Cornell Medicine Department of Dermatology, New York, NY, USA
| | - Cynthia M Magro
- Weill Cornell Medicine Department of Dermatology, New York, NY, USA
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Do MH, Schwartz Z, Abedian S, Lipner SR. Trends in psoriasis treatment 2005 to 2018: Declining phototherapy utilization and concomitant increased use of biologics. Dermatol Ther 2020; 33:e14276. [DOI: 10.1111/dth.14276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/23/2020] [Accepted: 08/30/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Mytrang H. Do
- Weill Cornell Medicine Tri‐Institutional MD‐PhD program New York New York USA
| | - Ziv Schwartz
- Department of Dermatology Weill Cornell Medicine New York New York USA
| | - Sajjad Abedian
- Weill Cornell Medicine Information Technologies & Services New York New York USA
| | - Shari R. Lipner
- Department of Dermatology Weill Cornell Medicine New York New York USA
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Schwartz Z, Magro CM. Intralesional overlap syndrome: Sclerodermic lupus panniculitis and sclerodermic discoid lupus erythematosus. JAAD Case Rep 2020; 6:166-168. [PMID: 32083161 PMCID: PMC7019040 DOI: 10.1016/j.jdcr.2019.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Ziv Schwartz
- Weill Cornell Medicine Department of Pathology and Laboratory Medicine, Division of Dermatopathology, New York, New York
- SUNY Downstate College of Medicine, Brooklyn, New York
| | - Cynthia M. Magro
- Weill Cornell Medicine Department of Pathology and Laboratory Medicine, Division of Dermatopathology, New York, New York
- Correspondence to: Cynthia M. Magro, MD, Weill Cornell Medicine, F309 1300 York Ave, New York, NY 10065.
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Schwartz Z, Lieberman MR, Siegel DM. The evolving maintenance of certification process: update on the financial status of the medical boards. Dermatol Online J 2020; 26:13030/qt93p2d3n2. [PMID: 32155020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 06/10/2023] Open
Abstract
Medical board organizations have accumulated large asset balances, in part due to the monetization of physician board recertification, as well as capital gains in positive investment conditions. Physicians across the country have raised concerns regarding the effectiveness and efficiency of existing recertification processes, to which the American Board of Medical Specialties and independent accreditation boards have responded with newly instituted changes. The present article analyzes the publicly available F990 tax forms of the medical boards in an effort to provide data to the ongoing debate. Although some boards have begun to mobilize assets in recent years, many continue to accumulate wealth. It remains to be seen whether the new recertification programs will bring about change or perpetuate organizational wealth.
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Affiliation(s)
| | | | - Daniel M Siegel
- Department of Dermatology, SUNY Downstate Health Sciences University, Brooklyn, NY.
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11
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Schwartz Z, Lieberman MR, Siegel DM. The evolving maintenance of certification process: update on the financial status of the medical boards. Dermatol Online J 2020. [DOI: 10.5070/d3261047181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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12
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Patel PS, Wu DB, Schwartz Z, Rosenfeld RM. Upper lip frenotomy for neonatal breastfeeding problems. Int J Pediatr Otorhinolaryngol 2019; 124:190-192. [PMID: 31202037 DOI: 10.1016/j.ijporl.2019.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/04/2019] [Accepted: 06/06/2019] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Upper lip tie, without concomitant tongue tie, can prevent proper flanging of the upper lip during breastfeeding, resulting in a poor seal and suck for the infant with nipple pain and maternal dissatisfaction. Due to the lack of published studies on this subject, we report our technique and outcomes for in-office release of isolated upper lip tie. METHODS Using CPT Code 40,806 for 'incision of labial frenulum', 22 mother-infant dyads with infant age under 60 days with breastfeeding problems and a restrictive upper lip frenum were identified. These infants underwent in-office release of upper lip tie as detailed below. Outcomes of the procedure were assessed by a telephone survey to mothers within the 4-week period post-procedure. RESULTS 82% of mothers reported an improved latch and 73% noted increased satisfaction with breastfeeding. Lip pain, if present, resolved within 24 h for most children. Recurrence was reported by 9% of mothers; no infection or other complications occurred. CONCLUSION Upper lip frenotomy, in properly selected infants, has favorable short-term outcomes with mild transient discomfort and a low rate of recurrence. Since our study was short-term and did not include a control group, we are unable to comment on procedure efficacy or long-term impact.
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Affiliation(s)
- Prayag S Patel
- Department of Otolaryngology, SUNY Downstate Medical Center, 450 Clarkson Avenue, MSC 126, Brooklyn, NY, 11203, USA
| | - Derek B Wu
- Department of Otolaryngology, SUNY Downstate Medical Center, 450 Clarkson Avenue, MSC 126, Brooklyn, NY, 11203, USA
| | - Ziv Schwartz
- Department of Otolaryngology, SUNY Downstate Medical Center, 450 Clarkson Avenue, MSC 126, Brooklyn, NY, 11203, USA
| | - Richard M Rosenfeld
- Department of Otolaryngology, SUNY Downstate Medical Center, 450 Clarkson Avenue, MSC 126, Brooklyn, NY, 11203, USA.
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Schwartz Z, Magro C, Nuovo G. The molecular-based differentiation of Heck's disease from its mimics including oral condyloma and white sponge nevus. Ann Diagn Pathol 2019; 43:151402. [PMID: 31473371 DOI: 10.1016/j.anndiagpath.2019.151402] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 08/21/2019] [Indexed: 10/26/2022]
Abstract
Heck's disease (focal or multifocal epithelial hyperplasia) is a benign, rare condition of the skin and mucous membranes induced by human papillomavirus (HPV) infection. Other entities that can induce large papillomatous lesions that involve the mucous membranes and skin include condyloma acuminatum, which is sexually transmitted, and white sponge nevus, often due to a mutation of cytokeratin 4 or 13. Six cases diagnosed as either Heck's disease (n = 2) or white sponge nevus (n = 4) and 6 oral condyloma were compared on histologic grounds and analyzed in situ for HPV DNA, including HPVs 6,11, and 13, as well as cytokeratins 4 and 13. Each case showed marked acanthosis, and para/hyperkeratosis. More variable histologic findings included rete ridge elongation, keratinocyte degeneration, and perinuclear halos. High copy HPV 13 DNA was evident in the squamous cells towards the surface in the two cases diagnosed as Heck's disease and in two cases diagnosed as white sponge nevus on clinical grounds. HPV 6/11 was found in each of the six condyloma. Marked decrease in either cytokeratin 4 or 13 was evident in the two cases diagnosed as white sponge nevus that were HPV DNA negative. It is concluded that in situ hybridization analyses including HPVs 6, 11, and 13 as well as immunohistochemistry for cytokeratins 4 and 13 can differentiate Heck's disease from condyloma and white sponge nevus, which can be difficult to differentiate on clinical and histologic grounds.
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Affiliation(s)
- Ziv Schwartz
- Weill Cornell Medicine, New York, NY, United States of America
| | - Cynthia Magro
- Weill Cornell Medicine, New York, NY, United States of America
| | - Gerard Nuovo
- The Ohio State University Comprehensive Cancer Center, Columbus, OH, United States of America; Discovery Life Sciences, Powell, OH, United States of America.
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14
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Affiliation(s)
- Ziv Schwartz
- Department of Dermatology, Weill Cornell Medicine, New York, NY, USA
- Department of Dermatology, SUNY Downstate, Brooklyn, NY, USA
| | - Marc Cohen
- Department of Dermatology, SUNY Downstate, Brooklyn, NY, USA
| | - Shari R. Lipner
- Department of Dermatology, Weill Cornell Medicine, New York, NY, USA
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15
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Schwartz Z, Geizhals S, Lipner SR, Fox JL. Denial of Illness in a Patient with Infiltrative Basal Cell Carcinoma. Skinmed 2019; 17:284-285. [PMID: 31627795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A 73-year-old Caucasian man presented with a pink, pearly papule anterior to his right ear. He was a well-educated, retired stockbroker. Biopsy revealed an infiltrating basal cell carcinoma (BCC). The dermatologist repeatedly attempted to contact the patient encouraging treatment. After ignoring calls and letters, he was lost to contact with dermatology for 10 years. In the interim, the patient presented to the emergency room after discovering maggots in his ear. He subsequently consulted a head and neck surgeon but refused the recommended surgical excision. Although still operable, by this time the patient had developed significant erosion (Figure 1), nerve damage with loss of taste, facial muscle control, and hearing loss. One year after surgical consultation, he returned to dermatology due to ear discharge and pain while chewing. Multiple clinicians urged him to reconsider surgery. The patient stated that he had avoided treatment for the previous 10 years, because he had felt "stronger than the cancer." He had been convinced that cancer "can't hurt me." Despite this, he conceded that denying treatments earlier was "probably the worst decision of my life." By then the cancer was inoperable and required chemotherapy. The patient again refused treatment and later expired.
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Affiliation(s)
- Ziv Schwartz
- Weill Cornell Medicine Dermatology, New York, NY
- SUNY Downstate College of Medicine, Brooklyn, NY
| | - Solomon Geizhals
- Weill Cornell Medicine Dermatology, New York, NY
- SUNY Downstate College of Medicine, Brooklyn, NY
- New Age Skin Research Foundation, Fresh Meadows, NY
| | | | - Joshua L Fox
- New Age Skin Research Foundation, Fresh Meadows, NY
- Advanced Dermatology P.C., Fresh Meadows, NY
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16
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Schwartz Z, Bowe RB, Coleman M, Magro CM. Pediatric oral Epstein-Barr virus associated self-remitting CD30+ lymphoproliferative disorder: A distinct entity. Ann Diagn Pathol 2018; 37:57-61. [PMID: 30292067 DOI: 10.1016/j.anndiagpath.2018.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 08/22/2018] [Indexed: 01/28/2023]
Abstract
Epstein-Barr virus (EBV) has a well-known association with lymphoproliferative disorders of B and T cell origin. EBV-related B cell lymphoproliferative disorders include Hodgkin and Burkitt lymphomas, lymphomatoid granulomatosis, EBV positive diffuse large cell B cell lymphoma of the elderly, as well as B cell lymphomas associated with solid organ transplantation and methotrexate use. EBV-related T cell disorders are primarily represented by NK/T- cell lymphoma. In a subset of patients, EBV has been implicated in CD30 positive B cell lymphoproliferative disorders of the oral mucosa falling under the rubric of the mucocutaneous ulcer of the oral cavity. We previously reported on an index series of endogenous CD30 positive T cell lymphoproliferative disorder of the oral cavity resembling borderline type C lymphomatoid papulosis. The clinical manifestation of type C oral lymphomatoid papulosis is that of a recurrent self-remitting ulcer of the oral mucosa, which histologically resembles anaplastic large cell lymphoma. Such cases can be misdiagnosed as aggressive lymphoma leading to unnecessary treatment with aggressive chemotherapeutic regimens. Whereas none of the patients in our index series exhibited EBV positivity, here we discuss a very unique example of a 14-year-old girl diagnosed with EBV positive CD30 positive lymphoproliferative disorder strongly resembling the cases of intra-oral type C lymphomatoid papulosis. The patient was initially diagnosed by a senior hematopathology consultant as having EBV positive aggressive NK/T-cell lymphoma. The significance of raising physician awareness regarding pediatric oral EBV associated CD30 positive lymphoproliferative disease of the oral cavity lies in preventing inadvertent exposure to toxic chemotherapeutic agents intended for treatment of aggressive look-alikes, namely anaplastic large cell lymphoma. Additionally, we include a literature review of similar reports of pediatric intra-oral EBV positive CD30 positive T cell lymphoproliferative disease.
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Affiliation(s)
- Ziv Schwartz
- Weill Cornell Medicine, 1300 York Ave, New York, NY 10065, USA; SUNY Downstate College of Medicine, 450 Clarkson Ave, Brooklyn, NY 11203, USA
| | - Robert B Bowe
- NYU Langone Hospital - Brooklyn, 110 55th Street, Brooklyn, NY 11220, USA.
| | - Morton Coleman
- Weill Cornell Medicine, 1300 York Ave, New York, NY 10065, USA
| | - Cynthia M Magro
- Weill Cornell Medicine, 1300 York Ave, New York, NY 10065, USA.
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Schwartz Z, Coolman BR. Closure of gastrointestinal incisions using skin staples alone and in combination with suture in 29 cats. J Small Anim Pract 2018; 59:281-285. [DOI: 10.1111/jsap.12834] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 12/31/2017] [Accepted: 01/04/2018] [Indexed: 11/26/2022]
Affiliation(s)
- Z. Schwartz
- Northeast Indiana Veterinary Emergency and Specialty Hospital; Fort Wayne, Indiana 46835 USA
- Mount Laurel Animal Hospital; Mount Laurel New Jersey, 08054 USA
| | - B. R. Coolman
- Northeast Indiana Veterinary Emergency and Specialty Hospital; Fort Wayne, Indiana 46835 USA
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Abstract
Hospitals are faced with the difficult decision as whether to evacuate their patients or shelter in place when a strong hurricane is predicted to affect the facility. This decision must balance for patients the risk of transport with the risk of staying. This article discusses the experience of a hospital faced with this problem in two consecutive years. The approach taken differed and the evaluation of the implications are discussed.
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Affiliation(s)
- Mark P Jarrett
- SVP & Chief Quality Officer, Associate Chief Medical Officer, Northwell Health, New Hyde Park, New York; Professor of Medicine, Zucker School of Medicine at Hofstra/Northwell, New Hyde Park, New York
| | | | - Mark Solazzo
- EVP & Chief Operating Officer, Northwell Health, New Hyde Park
| | - Eugene Tangney
- SVP & Chief Administrative Officer, Northwell Health, New Hyde Park, New York
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Cheng A, Chen H, Schwartz Z, Boyan BD. Imaging analysis of the interface between osteoblasts and microrough surfaces of laser-sintered titanium alloy constructs. J Microsc 2017; 270:41-52. [PMID: 28960365 DOI: 10.1111/jmi.12648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/07/2017] [Accepted: 09/07/2017] [Indexed: 11/30/2022]
Abstract
Previous work using focused ion beam (FIB) analysis of osteoblasts on smooth and microrough Ti surfaces showed that the average cell aspect ratio and distance from the surface are greater on the rough surface. In order to better interrogate the relationship between individual cells and their substrate using multiple imaging modalities, we developed a method that tracks the same cell across confocal laser scanning microscopy (CLSM) to correlate surface microroughness with cell morphology and cytoskeleton; scanning electron microscopy (SEM) to provide higher resolution for observation of nanoroughness as well as chemical mapping via energy dispersive X-ray spectroscopy; and transmission electron microscopy (TEM) for high-resolution imaging. FIB was used to prepare thin sections of the cell-material interface for TEM, or for three-dimensional electron tomography. Cells were cultured on laser-sintered Ti-6Al-4V substrates with polished or etched surfaces. Direct cell to surface attachments were observed across surfaces, though bridging across macroscale surface features occurred on rough substrates. Our results show that surface roughness, cell cytoskeleton and gross morphology can be correlated with the cell-material cross-sectional interface at the single cell level across multiple high-resolution imaging modalities. This work provides a platform method for further investigating mechanisms of the cell-material interface.
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Affiliation(s)
- A Cheng
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, U.S.A.,Department of Biomedical Engineering, Peking University, Beijing, China
| | - H Chen
- Department of Biomedical Engineering, Peking University, Beijing, China
| | - Z Schwartz
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, U.S.A.,Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, U.S.A
| | - B D Boyan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, U.S.A.,Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, U.S.A
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Abstract
Changes in dental implant materials, structural design, and surface properties can all affect biological response. While bulk properties are important for mechanical stability of the implant, surface design ultimately contributes to osseointegration. This article reviews the surface parameters of dental implant materials that contribute to improved cell response and osseointegration. In particular, we focus on how surface design affects mesenchymal cell response and differentiation into the osteoblast lineage. Surface roughness has been largely studied at the microscale, but recent studies have highlighted the importance of hierarchical micron/submicron/nanosurface roughness, as well as surface roughness in combination with surface wettability. Integrins are transmembrane receptors that recognize changes in the surface and mediate downstream signaling pathways. Specifically, the noncanonical Wnt5a pathway has been implicated in osteoblastic differentiation of cells on titanium implant surfaces. However, much remains to be elucidated. Only recently have studies been conducted on the differences in biological response to implants based on sex, age, and clinical factors; these all point toward differences that advocate for patient-specific implant design. Finally, challenges in implant surface characterization must be addressed to optimize and compare data across studies. An understanding of both the science and the biology of the materials is crucial for developing novel dental implant materials and surface modifications for improved osseointegration.
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Affiliation(s)
- B D Boyan
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - A Cheng
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA Department of Biomedical Engineering, Peking University, Beijing, China
| | - R Olivares-Navarrete
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Z Schwartz
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Hermann CD, Hyzy SL, Olivares-Navarrete R, Walker M, Williams JK, Boyan BD, Schwartz Z. Craniosynostosis and Resynostosis: Models, Imaging, and Dental Implications. J Dent Res 2016; 95:846-52. [PMID: 27076448 DOI: 10.1177/0022034516643315] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Craniosynostosis occurs in approximately 1 in 2,000 children and results from the premature fusion of ≥1 cranial sutures. If left untreated, craniosynostosis can cause numerous complications as related to an increase in intracranial pressure or as a direct result from cranial deformities, or both. More than 100 known mutations may cause syndromic craniosynostosis, but the majority of cases are nonsyndromic, occurring as isolated defects. Most cases of craniosynostosis require complex cranial vault reconstruction that is associated with a high risk of morbidity. While the first operation typically has few complications, bone rapidly regrows in up to 40% of children who undergo it. This resynostosis typically requires additional surgical intervention, which can be associated with a high incidence of life-threatening complications. This article reviews work related to the dental and maxillofacial implications of craniosynostosis and discusses clinically relevant animal models related to craniosynostosis and resynostosis. In addition, information is provided on the imaging modalities used to study cranial defects in animals and humans.
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Affiliation(s)
- C D Hermann
- School of Medicine, Emory University, Atlanta, GA, USA
| | - S L Hyzy
- Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - R Olivares-Navarrete
- Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - M Walker
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA, USA
| | - J K Williams
- Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - B D Boyan
- Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, USA Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA, USA
| | - Z Schwartz
- Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, USA Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Olivares-Navarrete R, Vesper K, Hyzy SL, Almaguer-Flores A, Boyan BD, Schwartz Z. Role of the N-terminal peptide of amelogenin on osteoblastic differentiation of human mesenchymal stem cells. Eur Cell Mater 2014; 28:1-10; discussion 10. [PMID: 25017640 DOI: 10.22203/ecm.v028a01] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Porcine enamel matrix derivative (pEMD), a complex mixture of proteins and peptides including full-length amelogenin protein, splice variants, and proteolytic peptides, is used clinically with a carrier to regenerate supportive tissue around teeth. During application, pEMD self-assembles as nanospheres and precipitates as a three-dimensional matrix to facilitate cell migration and differentiation. Amelogenin, the primary constituent of pEMD, stimulates osteoblast differentiation, but it is unclear what specific roles other components of pEMD play in determining biological response. This study examined the potential of one constituent of pEMD, the N-terminal amelogenin peptide (NTAP), to promote osteoblastic differentiation of human mesenchymal stem cells (MSCs) and to elucidate possible signaling pathways involved. Effects of porcine NTAP on MSC cultures were compared to those of recombinant human amelogenin. While amelogenin induced MSC osteoblastic differentiation, a more robust osteoblastic response was seen after NTAP treatment. A phospho-kinase proteasome array measuring phosphorylation of 35 proteins indicated that protein kinase C (PKC), extracellular signal-regulated kinase 1/2 (ERK1/2), and β-catenin were highly phosphorylated by NTAP. This was confirmed by measuring PKC activity and levels of phospho-ERK1/2 and β-catenin. Both amelogenin and NTAP increased PKC, but NTAP induced higher phosho-ERK1/2 and phospho-β-catenin than amelogenin. ERK1/2 inhibition blocked both amelogenin- and NTAP-induced increases in RUNX2, ALP, OCN, COL1, and BMP2. The results demonstrate that NTAP induces osteogenic differentiation of MSCs via PKC and ERK1/2 activation and β-catenin degradation. NTAP may be an active bone regeneration component of amelogenin, and may play this role in pEMD-stimulated periodontal regeneration.
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Affiliation(s)
- R Olivares-Navarrete
- Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, 601 West Main Street, Suite 396, Richmond, VA 23284,
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Hyzy S, Olivares-Navarrete R, Hutton D, Tan C, Boyan B, Schwartz Z. Microstructured titanium regulates interleukin production by osteoblasts, an effect modulated by exogenous BMP-2. Acta Biomater 2013; 9:5821-9. [PMID: 23123301 DOI: 10.1016/j.actbio.2012.10.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 10/19/2012] [Accepted: 10/24/2012] [Indexed: 01/23/2023]
Abstract
Microtextured implant surfaces increase osteoblast differentiation in vitro and enhance bone-to-implant contact in vivo and clinically. These implants may be used in combination with recombinant human bone morphogenetic protein 2 (rhBMP-2) to enhance peri-implant bone formation. However, the effect of surface modifications alone or in combination with rhBMP-2 on the osteoblast-produced inflammatory microenvironment is unknown. MG63 cells were cultured on tissue culture polystyrene or titanium substrates: smooth pretreated (PT, Ra=0.2μm), sandblasted/acid-etched (SLA, Ra=3.2μm) or hydrophilic-SLA (modSLA). Expression and protein production of pro-inflammatory interleukins (IL1b, IL6, IL8, IL17) and anti-inflammatory interleukins (IL10) were measured in cells with or without rhBMP-2. To determine which BMP signaling pathways were involved, cultures were incubated with BMP pathway inhibitors to blockSmad (dorsomorphin), TAB/TAK1 ((5Z)-7-oxozeaenol) or PKA (H-8) signaling. Culture on rough SLA and modSLA surfaces decreased pro-inflammatory interleukins and increased anti-inflammatory IL10. This effect was negated in cells treated with rhBMP-2, which caused an increase in pro-inflammatory interleukins and a decrease in anti-inflammatory interleukins through TAB/TAK signaling. The results suggest that surface microtexture modulates the inflammatory process during osseointegration, an effect that may enhance healing. However, rhBMP-2 in combination with microtextured titanium implants can influence the effect of cells on these surfaces, and may adversely affect cells involved in osseointegration.
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Gittens R, Olivares-Navarrete R, Tannenbaum R, Boyan B, Schwartz Z. Electrical implications of corrosion for osseointegration of titanium implants. J Dent Res 2011; 90:1389-97. [PMID: 21555775 PMCID: PMC3215755 DOI: 10.1177/0022034511408428] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 03/07/2011] [Accepted: 03/09/2011] [Indexed: 12/13/2022] Open
Abstract
The success rate of titanium implants for dental and orthopedic applications depends on the ability of surrounding bone tissue to integrate with the surface of the device, and it remains far from ideal in patients with bone compromised by physiological factors. The electrical properties and electrical stimulation of bone have been shown to control its growth and healing and can enhance osseointegration. Bone cells are also sensitive to the chemical products generated during corrosion events, but less is known about how the electrical signals associated with corrosion might affect osseointegration. The metallic nature of the materials used for implant applications and the corrosive environments found in the human body, in combination with the continuous and cyclic loads to which these implants are exposed, may lead to corrosion and its corresponding electrochemical products. The abnormal electrical currents produced during corrosion can convert any metallic implant into an electrode, and the negative impact on the surrounding tissue due to these extreme signals could be an additional cause of poor performance and rejection of implants. Here, we review basic aspects of the electrical properties and electrical stimulation of bone, as well as fundamental concepts of aqueous corrosion and its electrical and clinical implications.
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Affiliation(s)
- R.A. Gittens
- Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332-0363, USA
- School of Materials Science and Engineering, Georgia Institute of Technology, 711 Ferst Dr., Atlanta, GA, USA
| | - R. Olivares-Navarrete
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA, USA
| | - R. Tannenbaum
- Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332-0363, USA
- School of Materials Science and Engineering, Georgia Institute of Technology, 711 Ferst Dr., Atlanta, GA, USA
| | - B.D. Boyan
- Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332-0363, USA
- School of Materials Science and Engineering, Georgia Institute of Technology, 711 Ferst Dr., Atlanta, GA, USA
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA, USA
| | - Z. Schwartz
- Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332-0363, USA
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA, USA
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Almaguer-Flores A, Olivares-Navarrete R, Wieland M, Ximénez-Fyvie LA, Schwartz Z, Boyan BD. Influence of topography and hydrophilicity on initial oral biofilm formation on microstructured titanium surfaces in vitro. Clin Oral Implants Res 2011; 23:301-7. [PMID: 21492236 DOI: 10.1111/j.1600-0501.2011.02184.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES The aim of this study was to analyse the influence of the microtopography and hydrophilicity of titanium (Ti) substrates on initial oral biofilm formation. MATERIALS AND METHODS Nine bacterial species belonging to the normal oral microbiota, including: Aggregatibacter actinomycetemcomitans, Actinomyces israelii, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Parvimonas micra, Porphyromonas gingivalis, Prevotella intermedia, and Streptococcus sanguinis were tested on Ti surfaces: pretreatment (PT [R(a) <0.2 μm]), acid-etched (A [R(a) <0.8 μm]), A modified to be hydrophilic (modA), sand-blasted/acid-etched (SLA [R(a) =4 μm]), and hydrophilic SLA (modSLA). Disks were incubated for 24 h in anaerobic conditions using a normal culture medium (CM) or human saliva (HS). The total counts of bacteria and the proportion of each bacterial species were analysed by checkerboard DNA-DNA hybridization. RESULTS Higher counts of bacteria were observed on all surfaces incubated with CM compared with the samples incubated with HS. PT, SLA, and modSLA exhibited higher numbers of attached bacteria in CM, whereas SLA and modSLA had a significant increase in bacterial adhesion in HS. The proportion of the species in the initial biofilms was also influenced by the surface properties and the media used: SLA and modSLA increased the proportion of species like A. actinomycetemcomitans and S. sanguinis in both media, while the adhesion of A. israelii and P. gingivalis on the same surfaces was affected in the presence of saliva. CONCLUSIONS The initial biofilm formation and composition were affected by the microtopography and hydrophilicity of the surface and by the media used.
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Affiliation(s)
- A Almaguer-Flores
- Instituto de Investigaciones en Materiales, Universidad Nacional, Autónoma de México, Ciudad Universitaria, México, DF México
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Zhong M, Carney DH, Jo H, Boyan BD, Schwartz Z. Inorganic phosphate induces mammalian growth plate chondrocyte apoptosis in a mitochondrial pathway involving nitric oxide and JNK MAP kinase. Calcif Tissue Int 2011; 88:96-108. [PMID: 21104071 DOI: 10.1007/s00223-010-9433-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 09/02/2010] [Indexed: 10/18/2022]
Abstract
Chondrocytes in the hypertrophic zone of the growth plate undergo apoptosis during endochondral bone development via mechanisms that involve inorganic phosphate (Pi) and nitric oxide (NO). Recent evidence suggests that Pi-dependent NO production plays a role in apoptosis of cells in the resting zone as well. This study examined the mechanism by which Pi induces NO production and the signaling pathways by which NO mediates its effects on apoptosis in these cells. Pi decreased the number of viable cells based on MTT activity; the number of TUNEL-positive cells and the level of DNA fragmentation were increased, indicating an increase in apoptosis. Blocking NO production using the NO synthase (NOS) inhibitor L: -NAME or cells from eNOS(-/-) mice blocked Pi-induced chondrocyte apoptosis, indicating that NO production is necessary. NO donors NOC-18 and SNOG both induced chondrocyte apoptosis. SNOG also upregulated p53 expression, the Bax/Bcl-2 expression ratio, and cytochrome c release from mitochondria, as well as caspase-3 activity, indicating that NO induces apoptosis via a mitochondrial pathway. Inhibition of JNK, but not of p38 or ERK1/2, MAP kinase was able to block NO-induced apoptosis, indicating that JNK is necessary in this pathway. Pi elevates NO production via eNOS in resting zone chondrocytes, which leads to a mitochondrial apoptosis pathway dependent on JNK.
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Affiliation(s)
- M Zhong
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, GA 30332-0363, USA
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Bell BF, Schuler M, Tosatti S, Textor M, Schwartz Z, Boyan BD. Osteoblast response to titanium surfaces functionalized with extracellular matrix peptide biomimetics. Clin Oral Implants Res 2011; 22:865-72. [PMID: 21244501 DOI: 10.1111/j.1600-0501.2010.02074.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Functionalizing surfaces with specific peptides may aid osteointegration of orthopedic implants by favoring attachment of osteoprogenitor cells and promoting osteoblastic differentiation. This study addressed the hypothesis that implant surfaces functionalized with peptides targeting multiple ligands will enhance osteoblast attachment and/or differentiation. To test this hypothesis, we used titanium (Ti) surfaces coated with poly-l-lysine-grafted polyethylene glycol (PLL-g-PEG) and functionalized with two peptides found in extracellular matrix proteins, arginine-glycine-aspartic acid (RGD) and lysine-arginine-serine-arginine (KRSR), which have been shown to increase osteoblast attachment. KSSR, which does not promote osteoblast attachment, was used as a control. MATERIALS AND METHODS Sandblasted acid-etched titanium surfaces were coated with PLL-g-PEG functionalized with varying combinations of RGD and KRSR, as well as KSSR. Effects of these surfaces on osteoblasts were assessed by measuring cell number, alkaline phosphatase-specific activity, and levels of osteocalcin, transforming growth factor beta-1 (TGF-β1), and PGE(2). RESULTS RGD increased cell number, but decreased markers for osteoblast differentiation. KRSR alone had no effect on cell number, but decreased levels of TGF-β1 and PGE(2). KRSR and RGD/KRSR coatings inhibited osteoblast differentiation vs. PLL-g-PEG. KSSR decreased cell number and increased osteoblast differentiation, indicated by increased levels of osteocalcin and PGE(2). CONCLUSIONS The RGD and KRSR functionalized surfaces supported attachment but did not enhance osteoblast differentiation, whereas KSSR increased differentiation. RGD decreased this effect, suggesting that multifunctional peptide surfaces can be designed that improve peri-implant healing by optimizing attachment and proliferation as well as differentiation of osteoblasts, but peptide combination, dose and presentation are critical variables.
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Affiliation(s)
- B F Bell
- Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA
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Zhong M, Carney DH, Boyan BD, Schwartz Z. 17β-Estradiol regulates rat growth plate chondrocyte apoptosis through a mitochondrial pathway not involving nitric oxide or MAPKs. Endocrinology 2011; 152:82-92. [PMID: 21068162 DOI: 10.1210/en.2010-0509] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estrogens cause growth plate closure in both males and females, by decreasing proliferation and inducing apoptosis of postproliferative growth plate chondrocytes. In vitro studies using 17β-estradiol (E(2)) conjugated to bovine serum albumin (E(2)-BSA) show that rat costochondral growth plate resting zone chondrocytes also respond to E(2). Moreover, they are regulated by E(2)-BSA via a protein kinase C and ERK MAPK signaling pathway that is functional only in female cells. To better understand how E(2) regulates apoptosis of growth plate chondrocytes, rat resting zone chondrocytes cells were treated with E(2) or E(2)-BSA. E(2) caused apoptosis in male and female resting zone and growth zone chondrocytes in a dose-dependent manner, based on elevated DNA fragmentation, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and caspase-3 activation. E(2) also up-regulated p53 and Bax protein (Bcl-2-associated X protein) levels and induced release of cytochrome C from the mitochondria, indicating a mitochondrial apoptotic pathway. The apoptotic effect of E(2) did not involve elevated nitric oxide production or MAPKs. It was reduced by ICI 182780, which is an estrogen receptor (ER) antagonist and blocked by antibodies to Erα36, a membrane-associated ER. E(2)-BSA reduced cell viability and increased caspase-3 activity; ICI 182780 had no effect, but anti-ERα36 antibodies blocked the effect. The results indicate that estrogen is able to directly affect the cell population kinetics of growth plate chondrocytes by regulating apoptosis, as well as proliferation and differentiation in both resting zone and growth zone cells. They also have provided further information about the physiological functions of estrogen on longitudinal bone growth.
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Affiliation(s)
- M Zhong
- Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, Georgia 30332-0363, USA
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Hurst-Kennedy J, Zhong M, Gupta V, Boyan BD, Schwartz Z. 24R,25-Dihydroxyvitamin D3, lysophosphatidic acid, and p53: a signaling axis in the inhibition of phosphate-induced chondrocyte apoptosis. J Steroid Biochem Mol Biol 2010; 122:264-71. [PMID: 20594980 DOI: 10.1016/j.jsbmb.2010.05.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 05/23/2010] [Accepted: 05/27/2010] [Indexed: 11/20/2022]
Abstract
Maintenance of the pool of chondrocytes in the resting zone of the growth plate in the presence of the physiological apoptogen inorganic phosphate (Pi) is crucial for skeletal development. Costochondral resting zone chondrocytes are regulated by the vitamin D metabolite 24R,25-dihydroxyvitamin D3 [24R,25(OH)(2)D(3)], with increased production of sulfated glycosaminoglycan-rich extracellular matrix, and reduced matrix metalloproteinase activity. The effects of 24R,25(OH)(2)D(3) are mediated by activation of phospholipase D (PLD), resulting in increased production of lysophosphatidic acid (LPA) and LPA-mediated proliferation, maturation, inhibition of Pi-induced apoptosis, and reduction of p53. However, the exact mechanism by which 24R,25(OH)(2)D(3) and LPA exert their effects is not fully understood. It was found that both 24R,25(OH)(2)D(3) and LPA attenuate Pi-induced caspase-3 activity. The actions of 24R,25(OH)(2)D(3) and LPA were dependent upon G(αi), LPA receptor(s) 1 and/or 3, PLD, phospholipase C (PLC), and intracellular calcium, phosphoinositide 3-kinase (PI(3)K) signaling, and nuclear export. 24R,25(OH)(2)D(3) decreased both p53 abundance and p53-medaited transcription and inhibited Pi-induced cytochrome c translocation. Moreover, LPA induced increased mdm2 phosphorylation, a negative regulator of p53. Taken together, these data show that 24R,25(OH)(2)D(3) inhibits Pi-induced apoptosis through Ca(2+), PLD, and PLC signaling and through LPA-LPA1/3-G(αi)-PI(3)K-mdm2-mediated p53 degradation, resulting in decreased cytochrome c translocation and caspase-3 activity.
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Affiliation(s)
- J Hurst-Kennedy
- Department of Biomedical Engineering, School of Biology, Georgia Institute of Technology, Atlanta, GA 30332-0363, United States
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Boyan BD, Hurst-Kennedy J, Denison TA, Schwartz Z. 24R,25-dihydroxyvitamin D3 [24R,25(OH)2D3] controls growth plate development by inhibiting apoptosis in the reserve zone and stimulating response to 1alpha,25(OH)2D3 in hypertrophic cells. J Steroid Biochem Mol Biol 2010; 121:212-6. [PMID: 20307662 DOI: 10.1016/j.jsbmb.2010.03.057] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 03/13/2010] [Accepted: 03/15/2010] [Indexed: 10/19/2022]
Abstract
Previously we showed that costochondral growth plate resting zone (RC) chondrocytes response primarily to 24R,25(OH)2D3 whereas prehypertrophic and hypertrophic (GC) cells respond to 1alpha,25(OH)2D3. 24R,25(OH)2D3 increases RC cell proliferation and inhibits activity of matrix processing enzymes, suggesting it stabilizes cells in the reserve zone, possibly by inhibiting the matrix degradation characteristic of apoptotic hypertrophic GC cells. To test this, apoptosis was induced in rat RC cells by treatment with exogenous inorganic phosphate (Pi). 24R,25(OH)2D3 blocked apoptotic effects in a dose-dependent manner. Similarly, apoptosis was induced in ATDC5 cell cultures and 24R,25(OH)2D3 blocked this effect. Further studies indicated that 24R,25(OH)2D3 acts via at least two independent pathways. 24R,25(OH)2D3 increases LPA receptor-1 (LPA R1) expression and production of lysophosphatidic acid (LPA), and subsequent LPA R1/3-dependent signaling, thereby decreasing p53 abundance. LPA also increases the Bcl-2/Bax ratio. In addition, 24R,25(OH)2D3 acts by increasing PKC activity. 24R,25(OH)2D3 stimulates 1-hydroxylase activity, resulting in increased levels of 1,25(OH)2D3, and it increases levels of phospholipase A2 activating protein, which is required for rapid 1alpha,25(OH)2D3-dependent activation of PKC in GC cells. These results suggest that 24R,25(OH)2D3 modulates growth plate development by controlling the rate and extent of RC chondrocyte transition to a GC chondrocyte phenotype.
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Affiliation(s)
- B D Boyan
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, ATlanta, GA 30332-0363, USA.
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Schwartz Z, Doukarsky-Marx T, Nasatzky E, Goultschin J, Ranly DM, Greenspan DC, Sela J, Boyan BD. Differential effects of bone graft substitutes on regeneration of bone marrow. Clin Oral Implants Res 2008; 19:1233-45. [DOI: 10.1111/j.1600-0501.2008.01582.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Olivares-Navarrete R, Raz P, Zhao G, Chen J, Wieland M, Cochran DL, Chaudhri RA, Ornoy A, Boyan BD, Schwartz Z. Integrin alpha2beta1 plays a critical role in osteoblast response to micron-scale surface structure and surface energy of titanium substrates. Proc Natl Acad Sci U S A 2008; 105:15767-72. [PMID: 18843104 PMCID: PMC2564982 DOI: 10.1073/pnas.0805420105] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Indexed: 01/10/2023] Open
Abstract
Efforts to improve bone response to biomaterials have focused on ligands that bind alpha5beta1 integrins. However, antibodies to alpha5beta1 reduce osteoblast proliferation but do not affect differentiation when cells are grown on titanium (Ti). beta1-silencing blocks the differentiation stimulus of Ti microtopography, suggesting that other beta1 partners are important. Stably alpha2-silenced MG63 human osteoblast-like cells were used to test whether alpha2beta1 specifically mediates osteoblast response to Ti surface micron-scale structure and energy. WT and alpha2-silenced MG63 cells were cultured on tissue culture polystyrene (TCPS) and Ti disks with different surface microtopographies: machined pretreatment (PT) surfaces [mean peak to valley roughness (R(a)) < 0.02 microm], PT surfaces that were grit-blasted and acid-etched (SLA; R(a) = 4 microm), and SLA with high surface energy (modSLA). Alkaline phosphatase (ALP), alpha2 and beta1 mRNA, but not alpha5, alpha v, beta3, type-I collagen, or osteocalcin, increased on SLA and modSLA at 6 days. Alpha2 increased at 8 days on TCPS and PT, but remained unchanged on SLA and modSLA. Alpha2-protein was reduced 70% in alpha2-siRNA cells, whereas alpha5-mRNA and protein were unaffected. Alpha2-knockdown blocked surface-dependent increases in beta1 and osteocalcin and decreases in cell number and increases in ALP and local factors typical of MG63 cells grown on SLA and modSLA [e.g., prostaglandin E(2), osteoprotegerin, latent and active TGF-beta1, and stimulatory effects of 1alpha,25(OH)(2)D(3) on these parameters]. This finding indicates that alpha2beta1 signaling is required for osteoblastic differentiation caused by Ti microstructure and surface energy, suggesting that conclusions based on cell behavior on TCPS are not predictive of behavior on other substrates or the mechanisms involved.
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Affiliation(s)
- R. Olivares-Navarrete
- *Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - P. Raz
- Department of Periodontics, Hebrew University Hadassah, Jerusalem 91120, Israel
| | - G. Zhao
- *Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - J. Chen
- Institut Straumann AG, 4052 Basel, Switzerland
| | - M. Wieland
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China; and
| | - D. L. Cochran
- Department of Periodontics, Health Science Center, University of Texas, San Antonio, TX 78229
| | - R. A. Chaudhri
- *Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - A. Ornoy
- Department of Periodontics, Hebrew University Hadassah, Jerusalem 91120, Israel
| | - B. D. Boyan
- *Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Z. Schwartz
- *Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
- Department of Periodontics, Hebrew University Hadassah, Jerusalem 91120, Israel
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Boyan BD, Schwartz Z. 1,25-Dihydroxy vitamin D3 is an autocrine regulator of extracellular matrix turnover and growth factor release via ERp60-activated matrix vesicle matrix metalloproteinases. Cells Tissues Organs 2008; 189:70-4. [PMID: 18765931 DOI: 10.1159/000152916] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
As growth plate chondrocytes mature and hypertrophy, they reorganize their proteoglycan-rich type II collagen extracellular matrix (ECM), involving 1,25(OH)(2)D(3)-dependent regulation of matrix metalloproteinases (MMPs). Stromelysin-1 (MMP-3) and 72-kD gelatinase (MMP-2) are found in extracellular matrix vesicles (MVs) and release and activate ECM-bound latent TGF-beta1 and TGF-beta2, respectively. 1,25(OH)(2)D(3) regulates incorporation of MMP-2 and MMP-3 into MVs and release of these enzymes in the ECM. Plasma membranes (PMs) and MVs contain the 1alpha,25(OH)(2)D(3) membrane receptor ERp60 (protein disulfide isomerase A3), phospholipase A(2) (PLA(2)), PLA(2)-activating protein, the nuclear vitamin D receptor and caveolin-1. 1,25(OH)(2)D(3) secreted by chondrocytes binds MV ERp60, activating PLA(2). Resulting lysophospholipids destabilize MV membranes, releasing active MMPs. We examined 1,25(OH)(2)D(3)-dependent activation of latent TGF-beta1 stored in cartilage ECM. Interestingly, TGF-beta1 regulates 1,25(OH)(2)D(3) production. 1alpha,25(OH)(2)D(3) activates PM protein kinase C (PKC)-alpha via ERp60-dependent PLA(2)-signaling, lysophospholipid production and phospholipase C-gamma. It also regulates distribution of phospholipids and PKC isoforms between MVs and PMs, enriching MVs in PKC-zeta. Direct activation of MV MMP-3 requires ERp60 based on blocking antibodies and PKC based on inhibitor studies. However, treatment of MVs with 1,25(OH)(2)D(3) decreases MV PKC-zeta activity, suggesting more complex feedback mechanisms, potentially involving MV lipid signaling. Our observations indicate that one role of MVs is to provide MMPs at sites distant from the cells. Chondrocytes secrete 1,25(OH)(2)D(3), which acts directly on MV-membranes via ERp60, releasing MMPs. MMP-specific ECM components are hydrolyzed, resulting in release and activation of growth factors that can act back on the cells.
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Affiliation(s)
- B D Boyan
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, Ga. 30332-0363, USA.
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Schwartz Z, Simon BJ, Duran MA, Barabino G, Chaudhri R, Boyan BD. Pulsed electromagnetic fields enhance BMP-2 dependent osteoblastic differentiation of human mesenchymal stem cells. J Orthop Res 2008; 26:1250-5. [PMID: 18404656 DOI: 10.1002/jor.20591] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mesenchymal stem cells (MSCs) express an osteoblastic phenotype when treated with BMP-2, and BMP-2 is used clinically to induce bone formation although high doses are required. Pulsed electromagnetic fields (PEMF) also promote osteogenesis in vivo, in part through direct action on osteoblasts. We tested the hypothesis that PEMF enhances osteogenesis of MSCs in the presence of an inductive stimulus like BMP-2. Confluent cultures of human MSCs were grown on calcium phosphate disks and were treated with osteogenic media (OM), OM containing 40 ng/mL rhBMP-2, OM + PEMF (8 h/day), or OM + BMP-2 + PEMF. MSCs demonstrated minor increases in alkaline phosphatase (ALP) during 24 days in culture and no change in osteocalcin. OM increased ALP and osteocalcin by day 6, but PEMF had no additional effect at any time. BMP-2 was stimulatory over OM, and PEMF + BMP-2 synergistically increased ALP and osteocalcin. PEMF also enhanced the effects of BMP-2 on PGE2, latent and active TGF-beta1, and osteoprotegerin. Effects of PEMF on BMP-2-treated cells were greatest at days 12 to 20. These results demonstrate that PEMF enhances osteogenic effects of BMP-2 on MSCs cultured on calcium phosphate substrates, suggesting that PEMF will improve MSC response to BMP-2 in vivo in a bone environment.
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Affiliation(s)
- Z Schwartz
- Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, Georgia 30332, USA
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Zhong M, Wike L, Ryaby J, Carney D, Boyan B, Schwartz Z. Thrombin peptide TP508 prevents nitric oxide mediated apoptosis in chondrocytes in the endochondral developmental pathway. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 2008; 1783:12-22. [DOI: 10.1016/j.bbamcr.2007.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 10/12/2007] [Accepted: 10/16/2007] [Indexed: 11/25/2022]
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Schwartz Z, Denison TA, Bannister SR, Cochran DL, Liu YH, Lohmann CH, Wieland M, Boyan BD. Osteoblast response to fluid induced shear depends on substrate microarchitecture and varies with time. J Biomed Mater Res A 2007; 83:20-32. [PMID: 17340600 DOI: 10.1002/jbm.a.31185] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Osteoblasts are exposed to fluid shear in vivo but the effects are not well understood, particularly how substrate properties or length of exposure modify the response. Short exposure (1 h) to shear reduces the stimulatory effect of micron-scale surface structure on osteoblast differentiation, but the effects of longer term exposures are not known. To test the hypothesis that substrate-dependent responses of osteoblasts to shear depend on the length of exposure to fluid flow, MG63 osteoblasts were grown on tissue culture glass, which has an average roughness (Ra) < 0.2 microm; machined Ti disks (PT, Ra < 0.6 microm); Ti disks with a complex microarchitecture [sand blasted acid etched (SLA), Ra = 4-5 microm); and Ti plasma-sprayed surfaces [Ti via plasma spray (TPS), Ra = 7 microm]. Confluent cultures were exposed to pulsatile flow at shear forces of 0, 1, and 14 dynes/cm(2) for 0, 6, 12, and 24 h. Shear reduced cell number on all surfaces, with greatest effects on TPS. Shear had no effect on alkaline phosphatase on smooth surfaces but increased enzyme activity on SLA and TPS in a time-dependent manner. Its effects on osteocalcin, TGF-beta1, and PGE(2) in the conditioned media were greatest on these surfaces as well. Responses to fluid-induced shear were blocked by the general Cox inhibitor indomethacin and the Cox-2 inhibitor meloxicam, indicating that response to shear is mediated by prostaglandin produced via a Cox-2 dependent mechanism. These results show that the effects of fluid induced shear change with time and are substrate dependent, suggesting that substrate microarchitecture regulates the osteoblast phenotype and effects of shear are determined by the maturation state of the responding population.
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Affiliation(s)
- Z Schwartz
- Wallace H. Coulter Department of Biomedical Engineering, Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA
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Zhao G, Raines AL, Wieland M, Schwartz Z, Boyan BD. Requirement for both micron- and submicron scale structure for synergistic responses of osteoblasts to substrate surface energy and topography. Biomaterials 2007; 28:2821-9. [PMID: 17368532 PMCID: PMC2754822 DOI: 10.1016/j.biomaterials.2007.02.024] [Citation(s) in RCA: 283] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 02/19/2007] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Surface roughness and surface free energy are two important factors that regulate cell responses to biomaterials. Previous studies established that titanium (Ti) substrates with micron-scale and submicron scale topographies promote osteoblast differentiation and osteogenic local factor production and that there is a synergistic response to micro-rough Ti surfaces that have retained their high surface energy via processing that limits hydrocarbon contamination. This study tested the hypothesis that the synergistic response of osteoblasts to these modified surfaces depends on both surface micro-structure and surface energy. METHODS Ti disks were manufactured to present three different surface structures: smooth pretreatment (PT) surfaces with R(a) of 0.2 microm; acid-etched surfaces (A) with a submicron roughness R(a) of 0.83 microm; and sandblasted/acid-etched surfaces (SLA) with R(a) of 3-4 microm. Modified acid-etched (modA) and modified sandblasted/acid-etched (modSLA) Ti substrates, which have low contamination and present a hydroxylated/hydrated surface layer to retain high surface energy, were compared with regular low surface energy A and SLA surfaces. Human osteoblast-like MG63 cells were cultured on these substrates and their responses, including cell shape, growth, differentiation (alkaline phosphatase, osteocalcin), and local factor production (TGF-beta1, PGE(2), osteoprotegerin (OPG)) were analyzed (N=6 per variable). Data were normalized to cell number. RESULTS There were no significant differences between smooth PT and A surfaces except for a small increase in OPG. Compared to A surfaces, MG63 cells produced 30% more osteocalcin on modA, and 70% more on SLA. However, growth on modSLA increased osteocalcin by more than 250%, which exceeded the sum of independent effects of surface energy and topography. Similar effects were noted when levels of latent TGF-beta1, PGE(2) and OPG were measured in the conditioned media. CONCLUSIONS The results demonstrate a synergistic effect between high surface energy and topography of Ti substrates and show that both micron-scale and submicron scale structural features are necessary.
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Affiliation(s)
- G Zhao
- Georgia Institute of Technology, Atlanta, GA, USA
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Keselowsky BG, Wang L, Schwartz Z, Garcia AJ, Boyan BD. Integrin alpha(5) controls osteoblastic proliferation and differentiation responses to titanium substrates presenting different roughness characteristics in a roughness independent manner. J Biomed Mater Res A 2007; 80:700-10. [PMID: 17133443 DOI: 10.1002/jbm.a.30898] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Integrin alpha(5)beta(1) regulates osteoblast proliferation and differentiation on smooth synthetic surfaces presenting different chemistries, but it is not known whether this integrin controls osteoblast behavior on surfaces that have micron-scale rough topographies. We cultured MG63 human osteoblast-like cells on titanium substrates with three different roughness characteristics: chemically polished (PT), grit blasted and acid etched with a complex topography consisting of 20-100 mum craters and 0.5-2 mum micropits (SLA), and plasma-sprayed Ti with irregular projections (TPS). Cells spread well on PT but displayed a smaller footprint on SLA or TPS. Nuclei were larger on PT as well. alpha(5)beta(1) binding and FAK phosphorylation were greater on the rougher surfaces (TPS > SLA > PT). Antibodies against the alpha(5)beta(1) binding site on fibronectin had no effect on cell number at 3 days, but [(3)H]-thymidine incorporation was increased, suggesting that binding to fibronectin was necessary for cell cycle regulation. Antibodies to the alpha(5) subunit reduced cell number at 3 days on PT and TPS and reduced DNA synthesis on all substrates in a surface microstructure-independent manner. At 7 days, cell numbers were reduced on PT, and DNA synthesis was reduced by 50% on all surfaces. At 7 days, anti-alpha(5) antibodies caused a partial reduction in alkaline phosphatase enzyme activity on all surfaces, but this effect was independent of surface microstructure. These results indicate that surface micron-scale topography modulates alpha(5)beta(1) integrin binding and FAK activation. Signaling via alpha(5)-dependent mechanisms is required for DNA synthesis and regulation of alkaline phosphatase, but this effect is independent of surface microstructure.
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Affiliation(s)
- B G Keselowsky
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
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McMillan J, Kinney RC, Ranly DM, Fatehi-Sedeh S, Schwartz Z, Boyan BD. Osteoinductivity of demineralized bone matrix in immunocompromised mice and rats is decreased by ovariectomy and restored by estrogen replacement. Bone 2007; 40:111-21. [PMID: 16973427 DOI: 10.1016/j.bone.2006.07.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 07/18/2006] [Accepted: 07/18/2006] [Indexed: 10/24/2022]
Abstract
The osteoinduction potential of human demineralized bone matrix (DBM) in females with low estrogen (E2) is unknown. Moreover, the osteoinductivity of commercial human DBM is tested in male athymic rats and mice, but DBM performance in these animals may not reflect performance in female animals or provide information on E2's role in the process. To gain insight, human DBM was implanted bilaterally in the gastrocnemius of twenty-four athymic female mice (10 mg/implant) and twenty-four athymic female rats (15 mg/implant). Eight animals in each group were sham-operated (SHAM), ovariectomized (OVX), or ovariectomized with E2-replacement (OVX+E2) via subcutaneous slow release capsules of 17beta-estradiol. OVX and OVX+E2 animals were pair-fed to SHAM animals. Four animals from each group were euthanized at 35 days and four at 56 days. Animal weight, uterine weight, and blood estrogen levels confirmed that pair feeding, ovariectomy, and E2 replacement were successful. Histological sections of implanted tissues were evaluated qualitatively for absence or presence of DBM, ossicle formation, and new bone or cartilage using a previously developed qualitative scoring system (QS) and by histomorphometry to obtain a quantitative assessment of osteoinduction. OVX mice had a small but significant QS decrease at 35 days compared to SHAM mice, confirmed by quantitative measurement of ossicle, marrow space, and new bone areas. The QS in rats was not affected by OVX but histomorphometry showed decreased new bone in OVX rats, which was restored by E2. The QS indicated that the number of new bone sites was not reduced by OVX in rats or mice at 56 days, but the relative amount of new bone v. marrow space was affected and differed with animal species. Residual DBM was less in OVX animals, indicating that DBM resorption was affected. Cartilage was present in rats but not in mice, suggesting that endochondral ossification was slower and indicating that bone graft studies in these species are not necessarily comparable. These results show the importance of E2 in human DBM-induced bone formation and suggest that E2 may be needed for clinical effectiveness in post-menopausal women.
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Affiliation(s)
- J McMillan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, GA 30332, USA
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McMillan J, Fatehi-Sedeh S, Sylvia VL, Bingham V, Zhong M, Boyan BD, Schwartz Z. Sex-specific regulation of growth plate chondrocytes by estrogen is via multiple MAP kinase signaling pathways. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 2006; 1763:381-92. [PMID: 16713447 DOI: 10.1016/j.bbamcr.2006.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Revised: 02/07/2006] [Accepted: 02/27/2006] [Indexed: 10/24/2022]
Abstract
Both male and female rat growth plate cartilage cells possess estrogen receptors (ERs), but 17beta-estradiol (E(2)) activates protein kinase C (PKC) and PKC-dependent biological responses to E(2) only in cells from female animals. PKC signaling can elicit genomic responses via mitogen activated protein kinase (MAPK) and E(2) has been shown to activate ERK MAPK in many cells, suggesting that MAPK may play a role in growth plate chondrocytes as well. We tested if E(2) increases MAPK activity and if so, whether the response is limited to female cells, if it is PKC-dependent, and if the mechanism involves traditional ER pathways. We also determined the contribution of MAPK to the biological response of growth plate chondrocytes and assessed the relative contributions of ERK, p38 and JNK MAPKs. Female rat costochondral cartilage cells were treated with E(2) and MAPK-specific activity determined in cell layer lysates. The mechanism of MAPK activation was determined by treating the cells with E(2) conjugated to bovine serum albumin (E(2)-BSA) to assess if membrane receptors were involved; stereospecificity was determined using 17alpha-estradiol; PKC and phospholipase C (PLC) dependence was determined using specific inhibitors; and the ER agonist diethylstilbestrol, the ER antagonist ICI 182780, and tamoxifen were used to assess the role of traditional ER pathways. E(2) regulation of ERK1/2 MAPK was assessed and the relative roles of ERK1/2, p38 and JNK MAPKs determined using specific inhibitors. E(2) caused a rapid dose-dependent activation of MAPK that was greatest in cells treated for 9 min with 10(-9) M hormone; activity remained elevated for 3 h. E(2)'s effect on MAPK was stereospecific and comparable to that of E(2)-BSA. It was insensitive to DES and ICI 182780, dependent on PKC and PLC, blocked by tamoxifen and it did not require gene transcription or translation. E(2) had no effect on ERK1 or ERK2 mRNA or protein but it caused a rapid phosphorylation of ERK1/2 at 9 min. Inhibition of ERK1/2 and p38 MAPK reduced the stimulatory effects of E(2) on alkaline phosphatase activity and [(35)S]-sulfate incorporation. These results suggest that E(2) regulates MAPK through a sex-specific membrane-mediated mechanism that does not involve cytosolic ERs in a traditional sense and that ERK1/2 and p38 mediate the downstream biological effects of the hormone.
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Affiliation(s)
- J McMillan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, 30332, USA
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Ekstein J, Nasatzky E, Boyan BD, Ornoy A, Schwartz Z. Growth-plate chondrocytes respond to 17beta-estradiol with sex-specific increases in IP3 and intracellular calcium ion signalling via a capacitative entry mechanism. Steroids 2005; 70:775-86. [PMID: 16005036 DOI: 10.1016/j.steroids.2005.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 04/26/2005] [Accepted: 04/29/2005] [Indexed: 11/28/2022]
Abstract
17Beta-estradiol (E(2)) regulates growth-plate chondrocyte differentiation in a gender and cell maturation-dependent manner via classic nuclear receptors ERalpha and ERbeta, and membrane-associated signalling. Here we show that sex-specific effects of E(2) involve changes in intracellular calcium concentration (ICCC). Resting-zone chondrocytes (RC) and growth-zone chondrocytes (GC) were isolated from costochondral cartilage of male and female rats. Confluent cultures were treated with 10(-8)M E(2) or 17alpha-estradiol in the presence of high and low extracellular Ca(2+) concentration. The ICCC was determined using laser scanning confocal microscopy to measure changes in Fluo-4 fluorescence every 5s for a total of 500s. E(2) increased ICCC in the cells from female rats but had no effect on ICCC in male cells. The effect was rapid (peak at 140s) and stereospecific. E(2) increased ICCC in RC and GC chondrocytes but the effect was greater in RC cells. Low Ca(2+) media did not abolish the E(2)-dependent ICCC elevation, nor did inclusion of verapamil, which inhibits Ca(2+) channels on the cell membrane. Thapsigargin reduced the effect of E(2) on ICCC, showing that Ca(2+) pumps on the endoplasmic reticulum were involved. Pre-treatment of the cells with the ER antagonist ICI 182780 did not alter the stimulatory effect of E(2), suggesting that traditional estrogen receptor mechanisms do not play a role. E(2) caused rapid production of inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) but only in female cells, and the effect was greater in RC chondrocytes. These results indicate that E(2) regulates ICCC in a sex-specific and cell maturation state-dependent manner. The mechanism is membrane-associated and is mediated by PLC-dependent IP3 production and release of Ca(2+) from the endoplasmic reticulum.
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Affiliation(s)
- J Ekstein
- Department of Periodontics, Hebrew University, Hadassah School of Dental Medicine, Jerusalem, Israel
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Hirsch A, Goldstein M, Goultschin J, Boyan BD, Schwartz Z. A 2-Year Follow-Up of Root Coverage Using Subpedicle Acellular Dermal Matrix Allografts and Subepithelial Connective Tissue Autografts. J Periodontol 2005; 76:1323-8. [PMID: 16101365 DOI: 10.1902/jop.2005.76.8.1323] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Coverage of roots exposed by gingival recession is one of the main objectives of periodontal reconstructive surgery. A large variety of mucogingival grafting procedures are available. However, the long-term effectiveness of this procedure is still not clear. This study compared the effectiveness of sub-pedicle acellular dermal matrix allografts with subepithelial connective tissue autografts in achieving root coverage 2 years postoperatively. METHODS One hundred one (101) patients were treated with dermal matrix allografts (mean age, 28.4+/- 0.7 years; mean recession, 4.2 mm) and 65 patients treated with connective tissue graft (mean age, 30.1+/- 1.4 years; mean recession, 4.9 mm). All patients underwent full periodontal evaluation and presurgical preparation, including oral hygiene instruction and scaling and root planing. The exposed roots were thoroughly planed and covered by a graft without any further root treatment or conditioning. There were no differences in the average age, time of follow-up, or gender between the two groups. Patients were evaluated periodically between 1 and 2 years. Residual recession and defect coverage were assessed. RESULTS Mean residual root recession after root coverage with acellular dermal matrix allograft was 0.2 +/- 0.04 mm, with defect coverage of 95.9% +/- 0.9%. Frequency of defect coverage was 82.2%. Root coverage was 98.8% +/- 0.2%, resulting in a frequency of root coverage of 100%. Gain in keratinized gingiva was 2.2+/- 0.04 mm and attachment gain was 4.5+/- 0.1 mm per patient. Connective tissue autografts resulted in mean residual root recession of 0.1+/- 0.04 mm, with percent defect coverage of 97.8%+/- 0.6% and frequency of defect coverage of 95.4%. Root coverage was 99.1%+/- 0.2%, and frequency of root coverage was 100%. Gain in keratinized gingiva was 3.0+/- 0.1 mm and attachment gain was 5.3+/- 0.2 mm per patient. No significant differences in final recession and root coverage between the two treatment methods were found. However, autografts resulted in significant increases in defect coverage, keratinized gingival gain, attachment gain, and residual probing depth. The clinical results were stable for the 2-year follow-up period. CONCLUSIONS These results indicate that coverage of root by sub-pedicle acellular dermal matrix allografts or subepithelial connective tissue autografts is a very predictable procedure which is stable for 2 years postoperatively. However, subepithelial connective tissue autografts resulted in significant increases in defect coverage, keratinized gingival gain, attachment gain, and residual probing depth.
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Affiliation(s)
- A Hirsch
- Department of Periodontics, Hebrew University Hadassah Faculty of Dental Medicine, Jerusalem, Israel
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Zinger O, Zhao G, Schwartz Z, Simpson J, Wieland M, Landolt D, Boyan B. Differential regulation of osteoblasts by substrate microstructural features. Biomaterials 2005; 26:1837-47. [PMID: 15576158 DOI: 10.1016/j.biomaterials.2004.06.035] [Citation(s) in RCA: 286] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2004] [Accepted: 06/14/2004] [Indexed: 11/25/2022]
Abstract
Microtextured titanium implant surfaces enhance bone formation in vivo and osteoblast phenotypic expression in vitro, but the mechanisms are not understood. To determine the roles of specific microarchitectural features in modulating osteoblast behavior, we used Ti surfaces prepared by electrochemical micromachining as substrates for MG63 osteoblast-like cell culture. Cell response was compared to tissue culture plastic, a sand-blasted with large grit and acid-etched surface with defined mixed microtopography (SLA), polished Ti surfaces, and polished surfaces electrochemically machined through a photoresist pattern to produce cavities with 100, 30 and 10 microm diameters arranged so that the ratio of the microscopic-scale area of the cavities versus the microscopic-scale area of the flat region between the cavities was equal to 1 or 6. Microstructured disks were acid-etched, producing overall sub-micron-scale roughness (Ra=0.7 microm). Cell number, differentiation (alkaline phosphatase; osteocalcin) and local factor levels (TGF-beta1; PGE(2)) varied with microarchitecture. 100 microm cavities favored osteoblast attachment and growth, the sub-micron-scale etch enhanced differentiation and TGF-beta1 production, whereas PGE(2) depended on cavity dimensions but not the sub-micron-scale roughness.
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Affiliation(s)
- O Zinger
- Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
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Schwartz Z, Graham EJ, Wang L, Lossdörfer S, Gay I, Johnson-Pais TL, Carnes DL, Sylvia VL, Boyan BD. Phospholipase A2 activating protein (PLAA) is required for 1alpha,25(OH)2D3 signaling in growth plate chondrocytes. J Cell Physiol 2005; 203:54-70. [PMID: 15368540 DOI: 10.1002/jcp.20212] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Phospholipase A2 (PLA2) is pivotal in the rapid membrane-mediated actions of 1,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. Microarray analysis indicated that PLA2 activating protein (PLAA) mRNA is upregulated 6-fold before rat growth plate cells exhibit 1alpha,25(OH)2D3-dependent protein kinase C (PKC) increases, suggesting that it plays an important role in 1alpha,25(OH)2D3's mechanism of action. PLAA mRNA was confirmed in 1alpha,25(OH)2D3-responsive growth zone (prehypertrophic and upper hypertrophic cell zones) chondrocytes by RT-PCR and Northern blot in vitro and by in situ hybridization in vivo. PLAA protein was shown by Western blot and immunohistochemistry. PLAAs role in 1alpha,25(OH)2D3 signaling was evaluated in growth zone cell cultures using PLAA peptide. Arachidonic acid release was increased as was PLA2-specific activity in plasma membranes and matrix vesicles. PKCalpha, but not PKCbeta, PKCepsilon, or PKCzeta, was increased. PLAAs effect was comparable to that of 1alpha,25(OH)2D3 and was additive with 1alpha,25(OH)2D3. PLA2 inhibitors quinacrine and AACOCF3, and cyclooxygenase inhibitor indomethacin blocked the effect of PLAA peptide on PKC, indicating arachidonic acid and its metabolites were involved. This was confirmed using exogenous arachidonic acid. Prostaglandin acted via EP1 based on inhibition by SC19220 and not via EP2 since AH6809 had no effect. Like 1alpha,25(OH)2D3, PLAA peptide also increased activity of phospholipase C-specific activity via beta-1 and beta-3 isoforms, but not delta-1 or gamma-1; the effect of PLAA was via lysophospholipid but not via arachidonic acid. PLAA peptide decreased [3H]-thymidine incorporation to 50% of the decrease caused by 1alpha,25(OH)2D3. In contrast, PLAA peptide increased alkaline phosphatase-specific activity and proteoglycan production in a manner similar to 1alpha,25(OH)2D3. This indicates that PLAA is a specific activator of PLA2 in growth plate chondrocytes, and suggests that it mediates the membrane effect of 1alpha,25(OH)2D3, thereby modulating physiological response.
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Affiliation(s)
- Z Schwartz
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Kinney RC, Schwartz Z, Week K, Lotz MK, Boyan BD. Human articular chondrocytes exhibit sexual dimorphism in their responses to 17beta-estradiol. Osteoarthritis Cartilage 2005; 13:330-7. [PMID: 15780646 DOI: 10.1016/j.joca.2004.12.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2004] [Accepted: 12/11/2004] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The higher incidence of osteoarthritis in females suggests that there may be intrinsic sex-specific differences in human articular chondrocytes. 17beta-Estradiol (E2) regulates rat growth plate chondrocytes through traditional nuclear receptor mechanisms, but only female cells exhibit rapid membrane-associated effects mediated through protein kinase C (PKC) alpha. Here we demonstrate sexual dimorphism in the physiological response of human articular chondrocytes to E2. METHODS Articular chondrocytes were obtained at the time of autopsy from three male and three female donors between 16 and 39 years of age. Second passage cultures were treated with E2 for 24 h to assess the effects of the hormone on [3H]-thymidine incorporation, [35S]-sulfate incorporation, and alkaline phosphatase specific activity. In addition, the chondrocytes were treated for 3, 9, 90 or 270 min and PKC specific activity was determined. RESULTS All chondrocytes were positive for aggrecan and estrogen receptor alpha mRNAs but were negative for type II collagen mRNA. Only cells from female donors responded to E2. DNA synthesis, sulfate incorporation and alkaline phosphatase activity were increased. E2 caused a rapid increase in PKC activity in the female cells within 9 min that was maximal at 90 min. Treatment with the PKC inhibitor chelerythrine blocked these effects. CONCLUSIONS These results provide the first definitive evidence that normal human cells exhibit an intrinsic sex-specific response to E2 and suggest that sexual dimorphism may be an important variable in assessing the pathways that modulate cell behavior.
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Affiliation(s)
- R C Kinney
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Venezia E, Abed Y, Raz P, Goldstein M, Schwartz Z. [Localized aggressive periodontitis: a possible site-specific rather than tooth-specific disease?]. Refuat Hapeh Vehashinayim (1993) 2005; 22:7-13, 84. [PMID: 16121953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The diagnosis of localized aggressive periodontitis includes first molar attachment loss as an obligatory criterion. This tooth-specific based diagnosis has never been questioned or tested previously. We present a rare case of aggressive periodontitis that developed during orthodontic treatment, which included extraction of right lower first molar and bodily movement of the second molar to the original first molar site. At the end of the orthodontic therapy, localized periodontal disease was diagnosed at the site of the lower left first molar and the second lower right molar that was now occupying the site of the former first lower molar. The patient's periodontal condition was stabilized, and the bony defects were filled following periodontal treatment. This report shows that bacterial induced aggressive periodontitis developed during orthodontic treatment in a site-specific manner and suggest the hypothesis that localized aggressive periodontitis was targeted to a specific alveolar site rather than a tooth-specific site.
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Affiliation(s)
- E Venezia
- Dept. of Periodontics, The Hebrew University-Hadassah School of Dental Medicine, Jerusalem
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Raz P, Lohmann CH, Turner J, Wang L, Poythress N, Blanchard C, Boyan BD, Schwartz Z. 1alpha,25(OH)2D3 regulation of integrin expression is substrate dependent. J Biomed Mater Res A 2005; 71:217-25. [PMID: 15386491 DOI: 10.1002/jbm.a.30134] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Osteoblasts are attachment-dependent cells that interact with their surface through integrin-mediated mechanisms. Their differentiation is regulated by 1,25-dihydroxyvitamin D3 [1alpha,25(OH)(2)D(3)] and is affected by substrate chemistry and microtopography, suggesting that 1alpha,25(OH)(2)D(3) may regulate integrin expression in a surface-specific manner. To test this hypothesis, osteoblast-like human MG63 cells were grown on tissue culture plastic and on grit-blasted and acid-etched titanium disks with a complex microtopography to induce osteoblast differentiation. Expression of alpha(2), alpha(5), alpha(v), beta(1), and beta(3) integrins were quantified by real-time polymerase chain reaction (PCR) as a function of time in culture and treatment with 1alpha,25(OH)(2)D(3). Results were correlated with expression of osteocalcin, a marker of a differentiated osteoblast. Osteocalcin mRNA increased with time and 1alpha,25(OH)(2)D(3) treatment and these changes were greater in cultures on the titanium disks. Integrin expression varied with time in culture and this was also surface dependent. At each time point, beta(1) and alpha(2) mRNAs were greater on titanium than on plastic, whereas alpha(5) expression was reduced and alpha(v),beta(3) expression was unaffected. 1alpha,25(OH)(2)D(3) increased beta(1) mRNA on both surfaces at all time points, but it increased alpha(2) expression only in 8-d cultures. 1alpha,25(OH)(2)D(3) caused reduced alpha(5) expression only in cultures grown on plastic for 8 d, and had no effect on either alpha(v) or beta(3) expression regardless of surface. These results show that integrin expression in human osteoblast-like cells is differentially modulated by 1alpha,25(OH)(2)D(3) in a time-dependent manner that is sensitive to the surface on which the cells are grown.
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Affiliation(s)
- P Raz
- Department of Periodontics, Hebrew University Hadassah, Jerusalem, Israel
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Schwartz Z, Carney DH, Crowther RS, Ryaby JT, Boyan BD. Thrombin peptide (TP508) treatment of rat growth plate cartilage cells promotes proliferation and retention of the chondrocytic phenotype while blocking terminal endochondral differentiation. J Cell Physiol 2005; 202:336-43. [PMID: 15534863 DOI: 10.1002/jcp.20145] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A synthetic peptide representing the receptor-binding domain of human thrombin (TP508, also known as Chrysalin) accelerates fracture repair in rats via endochondral ossification and promotes repair of rabbit cartilage defects. To understand how this peptide might stimulate cartilage and bone formation, we employed an established in vitro model of growth plate cartilage regulation. Rat costochondral cartilage resting zone and growth zone chondrocytes were treated with 0, 0.07, 0.7, or 7 microg/ml TP508 or a scrambled peptide, TP508-SP. Proliferation ([3H]-thymidine incorporation) was examined in pre-confluent cultures; effects on cell number, alkaline phosphatase activity, [35S]-sulfate incorporation, and responsiveness to vitamin D metabolites were tested using confluent cultures. TP508 did not affect proliferation of resting zone cells but it caused a dose-dependent increase in cell number and DNA synthesis of growth zone cells. Alkaline phosphatase specific activity of resting zone cells was reduced by TP508, whereas [35S]-sulfate incorporation was increased. Neither parameter was affected in growth zone cell cultures. TP508 treatment for 24 h did not induce resting zone cells to respond to 1alpha,25(OH)2D3, either with respect to alkaline phosphatase activity or proteoglycan production. In contrast, TP508 treatment reduced the stimulatory effect of 24R,25(OH)2D3 on alkaline phosphatase but it did not alter the stimulatory effect of 24R,25(OH)2D3 on [35S]-sulfate incorporation. In cultures treated for 48, 72, or 140 h with TP508, 1alpha,25(OH)2D3 restored alkaline phosphatase activity to control levels but did not stimulate activity over levels observed in untreated control cultures. The stimulatory effect of TP508 on [35S]-sulfate incorporation was evident up to 48 h post-confluence but at later time points, proteoglycan production was comparable to that seen in control cultures, control cultures challenged with 1alpha,25(OH)2D3, and cultures treated with TP508 followed by 1alpha,25(OH)2D3. TP508-SP had no effect on any of the parameters tested. These results indicate that TP508 exerts maturation specific effects on chondrocytes in the endochondral lineage, promoting cartilage extracellular matrix synthesis over endochondral differentiation in resting zone cells and proliferation over differentiation of growth zone cells.
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Affiliation(s)
- Z Schwartz
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Gáspárdy A, Schwartz Z, Zöldág L, Veresegyházy T, Fekete S. Changes in daily energy amounts of main milk components (lactose, protein and fat) during the lactation of high-yielding dairy cows. Acta Vet Hung 2005; 52:457-67. [PMID: 15595279 DOI: 10.1556/avet.52.2004.4.8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this study was to examine the changes of the daily energy amount of lactose, protein and fat throughout the lactations, and compare them to each other. A total of 309 Israeli Holstein-Friesian cows from one kibbutz were investigated in three lactations, and information was given for a period of five years from 1996 to the end of 2000. The distribution of milk components and milk yield during lactation, and changes of the absolute and relative energy amount in the different milk components were calculated and evaluated. The results showed changes in the energy content of milk and its different components throughout the lactation. Each component (fat, lactose and protein) is dominant in different periods during the lactation. The energy amount from fat reaches a peak first, between days 40 and 50. Lactose has a peak at about day 66 of lactation, and protein reaches the peak last, approximately at day 104 of lactation. It seems that this peak sequence is constant and it is considered to be physiological. It might be suggested that there is a regulation governing the secretion of the different components at different times, and only one component is dominant in a given period. Each component exerts negative and positive influences on the secretion of the other components, which interact with each other and are not fully independent.
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Affiliation(s)
- A Gáspárdy
- Department of Animal Breeding, Nutrition and Laboratory Animal Science and Faculty of Veterinary Science, Szent István University, H-1078 Budapest, István u. 2, Hungary.
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Raz P, Nasatzky E, Boyan BD, Ornoy A, Schwartz Z. Sexual dimorphism of growth plate prehypertrophic and hypertrophic chondrocytes in response to testosterone requires metabolism to dihydrotestosterone (DHT) by steroid 5-alpha reductase type 1. J Cell Biochem 2005; 95:108-19. [PMID: 15723286 DOI: 10.1002/jcb.20298] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Rat costochondral growth plate chondrocytes exhibit sex-specific and cell maturation dependent responses to testosterone. Only male cells respond to testosterone, although testosterone receptors are present in both male and female cells, suggesting other mechanisms are involved. We examined the hypothesis that the sex-specific response of rat costochondral cartilage cells to testosterone requires further metabolism of the hormone to dihydrotestosterone (DHT). Resting zone (RC) and growth zone (GC, prehypertrophic and upper hypertrophic zones) chondrocytes from male and female Sabra strain rats exhibited sex-specific responses to testosterone and DHT: only male cells were responsive. Testosterone and DHT treatment for 24 h caused a comparable dose-dependent increase in [3H]-thymidine incorporation in quiescent preconfluent cultures of male GC cells, and a comparable increase in alkaline phosphatase specific activity in confluent cultures. RC cells responded in a differential manner to testosterone and DHT. Testosterone decreased DNA synthesis in male RC cells but DHT had no effect and alkaline phosphatase specific activity of male RC cells was unaffected by either hormone. Inhibition of steroid 5alpha-reductase activity with finasteride (1, 5, or 10 microg/ml), reduced the response of male GC cells to testosterone in a dose-dependent manner, indicating that metabolism to DHT was required. RT-PCR showed that both male and female cells expressed mRNAs for steroid 5alpha-reductase type 1 but lacked mRNAs for the type 2 form of the enzyme. Male cells also exhibited 5alpha-reductase activity but activity of this enzyme was undetectable in female cells. These observations show that sex-specific responses of rat growth zone chondrocytes to testosterone requires the further metabolism of the hormone to DHT and that the effect of DHT in the male growth plate is maturation-state dependent. Failure of female chondrocytes to respond to testosterone may reflect differences in testosterone metabolism, since these cells possess greater ability to aromatize the hormone to estradiol.
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Affiliation(s)
- P Raz
- Hebrew University Hadassah, Jerusalem, Israel
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