Orthopedics Commons^™

Loss Of Mct1 Mediated Lactate Uptake Causes Delayed Endplate Maturation And Intervertebral Disc Degeneration, Maria Tsingas, Konstantinos Tsingas, Mei Smyers, Wujuan Zhang, Aaron R. Goldman, Eulisa Lawrence, John A. Collins, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

During skeletal growth, it is thought that the lactate secreted by the glycolytic nucleus pulposus (NP) cells exits the intervertebral disc into circulation via endplates. Our current studies challenge this long-held notion. Mice with early postnatal, endplate, and annulus fibrosus-specific deletion of lactate importer, MCT1, exhibited disc degeneration characterized by NP cell loss and pronounced endplate structural changes. Using metabolic and transcriptomic approaches, we demonstrate that MCT1 loss inhibits endplate chondrocyte differentiation and that lactate serves both as a crucial TCA metabolite and promotes protein and histone lactylation and gene expression. These findings suggest that during skeletal growth, NP-derived lactate …

Surgical Revision In The Presence Of An S. Aureus Infection Increases Virulence Factor Expression And Activates A Multi-Tissue Inflammatory Response, Carly J. Smith, Arianna J. Moniodes, Amanda R. Watkins, Autumn G. Melvage, Thomas P. Thompson, Eirene Choi, Abigail A. Lucas, Brendan F. Gilmore, Thomas P. Schaer, Noreen J. Hickok, Theresa A. Freeman

Department of Orthopaedic Surgery Faculty Papers

Replacing implanted medical hardware due to infection often requires one or more revision surgeries. Each surgery triggers a tissue injury response and disrupts the established bacterial biofilm. However, the complex tissue response to reinjury and biofilm disturbance is not well understood. Our results show that with an existing infection, immunological niches such as the bone marrow, lymph nodes, and circulating blood further upregulate pro-inflammatory programs in response to revision. Rather than reducing bacterial burden, this heightened inflammation provokes virulence factor expression and tissue damage, including bone osteolysis and muscle fibrosis. While muscle fibrosis appears transient and begins resolving by 14 …

The Loss Of Opa1 Accelerates Intervertebral Disc Degeneration And Osteoarthritis In Aged Mice, Vedavathi Madhu, Miriam Hernandaz-Meadows, Ashley Coleman, Kimheak Sao, Kameron Inguito, Owen Haslam, Paige Boneski, Hiromi Sesaki, Ruteja Barve, John Collins, Makarand Risbud

Department of Orthopaedic Surgery Faculty Papers

Recent studies have highlighted the importance of mitochondria in NP cells and articular chondrocyte health. Since the understanding of mechanisms governing mitochondrial dynamics in these tissues is lacking, we investigated the role of OPA1, a mitochondrial fusion protein, in their homeostasis. OPA1 knockdown in NP cells altered mitochondrial size and cristae shape and increased the oxygen consumption rate. OPA1 governed the morphology of multiple organelles, including peroxisomes, early endosomes and cis-Golgi and loss resulted in the dysregulation of autophagy. Metabolic profiling and

The Effect Of Celecoxib And Mumab911 On Strain Adaptive Bone Remodeling And Fracture Repair In Female Mice: Implications For Rapidly Progressive Osteoarthritis, Nicholas Ruggiero, Alexandra Ciuciu, Ashkan Sedigh, Ibtesam Rajpar, David Shelton, Patrice Belanger, Kathryn Gropp, John A. Collins, Theresa A. Freeman, Ryan E. Tomlinson

Department of Orthopaedic Surgery Faculty Papers

Debilitating pain is the primary clinical feature of osteoarthritis (OA) that drives the enormous healthcare costs. Osteoarthritis-related pain is often treated with non-steroidal anti-inflammatory drugs (NSAIDs), which effectively relieve pain and inflammation by inhibition of prostaglandin synthesis. Antibodies directed against nerve growth factor (NGF) were tested some time ago as an alternative potential analgesic for musculoskeletal pain, including osteoarthritis-related pain. Unfortunately, clinical development of these drugs was put on hold due to adverse outcomes - primarily rapidly progressive osteoarthritis. Both prostaglandin synthesis and NGF have been implicated as critical mediators of strain adaptive bone remodeling, which may play a role …

Sirt6 Deficiency Promotes Senescence And Age-Associated Intervertebral Disc Degeneration In Mice, Pranay Ramteke, Bahiyah Watson, Mallory Toci, Victoria Tran, Shira N Johnston, Maria Tsingas, Ruteja Barve, Ramkrishna Mitra, Richard Loeser, John Collins, Makarand Risbud

Department of Orthopaedic Surgery Faculty Papers

Intervertebral disc degeneration is a major risk factor contributing to chronic low back and neck pain. While the etiological factors for disc degeneration vary, age is still one of the most important risk factors. Recent studies have shown the promising role of SIRT6 in mammalian aging and skeletal tissue health, however its role in the intervertebral disc health remains unexplored. We investigated the contribution of SIRT6 to disc health by studying the age-dependent spinal phenotype of mice with conditional deletion of Sirt6 in the disc (Acan^CreERT2; Sirt6^fl/fl). Histological studies showed a degenerative phenotype in knockout mice …

Evaluating Bone Fracture Healing In A Rabbit Model Using Doppler Imaging Modes, Shear Wave Elastography, X-Ray, And Dual-Energy X-Ray Absorptiometry, Priscilla Machado, Rachel Blackman, Ji-Bin Liu, Collleen Dempsey, Flemming Forsberg, Traci Fox

Department of Radiology Faculty Papers

OBJECTIVE: This study investigated methods of evaluating the bone fracture healing process using superb microvascular imaging (SMI; two modes color SMI [cSMI] and monochromeSMI [mSMI]), and shear wave elastography (SWE), relative to X-ray, dual-energy X-ray absorptiometry (DXA), and platelet endothelial cell adhesion molecule 1 (PECAM-1) also know as cluster of differentiation 31 (CD-31) staining in a rabbit model.

METHODS: This IACUC-approved study involved eight rabbits that underwent a bilateral fibula osteotomy and were followed for 7 or 21 days (Groups 1 and 2 with 4 rabbits in each). Ultrasound examinations using cSMI, mSMI, and SWE were performed on Days 0, …

Ibuprofen, Flurbiprofen Or Naproxen Sodium Minimally Influences Musculoskeletal Adaptations To Treadmill Exercise In Rats, Brandon Roberts, Alyssa Geddis, Alexandra Ciuciu, Marinaliz Reynoso, Nikhil Mehta, Alyssa Varanoske, Alyssa Kelley, Maximus Leiss, Alexander Kolb, Julie Hughes, Marshall Naimo, Ryan Tomlinson, Jeffery Staab

Department of Orthopaedic Surgery Faculty Papers

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) may influence musculoskeletal health. The purpose of this study was to compare the effects of three different NSAIDS: naproxen sodium, ibuprofen, flurbiprofen or a placebo on musculoskeletal adaptations in rodents with or without 6 weeks of aerobic exercise.

METHODS: Nine-week-old male Wistar rats (n = 80) were randomized to either exercise (EX) or no-exercise control (CON) conditions and treated with naproxen, ibuprofen (IBU), flurbiprofen (FLU) or placebo (PLA). For exercise, rats ran 5 days per week for 6 weeks at a 5% incline on a motorized treadmill for 30 min. Three-point bending (3 PB) and …

Ultrasound-Triggered Release Of Vancomycin From A Novel Spinal Device: Antibiotic Release And Efficacy In Vivo, Lauren J. Delaney, Priscilla Machado, Ji-Bin Liu, Rachel Evans, Asia Winslow, Neil Zhao, Christopher K. Kepler, Rajkishen Narayanan, Teeto Ezeonu, Viren Soni, Gagan Kaushal, Rachel Hilliard, Thomas P. Schaer, Noreen J. Hickok, Flemming Forsberg

Department of Orthopaedic Surgery Faculty Papers

Post-surgical spinal infection occurs in up to 20 % of patients, despite aggressive peri-operative antibiotic treatments. To improve prophylaxis, we have designed and evaluated an ultrasound-activated prophylactic antibiotic release system to combat post-surgical bacterial survival. Polylactic acid (PLA) clips (1 cm³) were 3D-printed with an interior reservoir (0.8 cm³) for carrying drug payload, specifically vancomycin (VAN). Under IACUC approval, clips were surgically implanted into the spines of sheep (n = 9) and swine (n = 2) by removing the spinous process at several levels of the lumbar spine. In the sheep, clips were insonated and the …

Structure And Function Are Not The Same: The Case For Restoring Mechanoreceptor Continuity Following Anterior Cruciate Ligament Injury, Jillian E Beveridge, Payam Zandiyeh, Brett D Owens, Ata M Kiapour, Braden C Fleming

Faculty, Staff and Student Publications

Anterior cruciate ligament (ACL) injury, particularly in increasingly young and active adolescents, continues to pose a clinical challenge with re-injury rates reported as high as 30%. Evidence also suggests that current standard-of-care ACL reconstruction (ACLR) does not mitigate post-traumatic osteoarthritis (PTOA) risk. Bridge- enhanced ACL restoration (BEAR) is a recently developed and tested ACL surgery that promotes primary healing of the native ACL with excellent early results. BEAR has shown to reduce signs of early PTOA compared to ACLR in an animal model. Here, we describe a theoretical framework related to re-innervation that can clarify why the outcomes of ACLR …

Leukocyte Immunoglobulin-Like Receptor B1 (Lilrb1) Protects Human Multiple Myeloma Cells From Ferroptosis By Maintaining Cholesterol Homeostasis, Miao Xian, Qiang Wang, Liuling Xiao, Ling Zhong, Wei Xiong, Lingqun Ye, Pan Su, Chuanchao Zhang, Yabo Li, Robert Z Orlowski, Fenghuang Zhan, Siddhartha Ganguly, Youli Zu, Jianfei Qian, Qing Yi

Faculty, Staff and Student Publications

Multiple myeloma (MM) is a hematologic malignancy characterized by uncontrolled proliferation of plasma cells in the bone marrow. MM patients with aggressive progression have poor survival, emphasizing the urgent need for identifying new therapeutic targets. Here, we show that the leukocyte immunoglobulin-like receptor B1 (LILRB1), a transmembrane receptor conducting negative immune response, is a top-ranked gene associated with poor prognosis in MM patients. LILRB1 deficiency inhibits MM progression in vivo by enhancing the ferroptosis of MM cells. Mechanistic studies reveal that LILRB1 forms a complex with the low-density lipoprotein receptor (LDLR) and LDLR adapter protein 1 (LDLRAP1) to facilitate LDL/cholesterol …

Tumor Treating Fields Suppress Tumor Cell Growth And Neurologic Decline In Models Of Spinal Metastases, Daniel Ledbetter, Romulo Augusto Andrade De Almeida, Xizi Wu, Ariel Naveh, Chirag B Patel, Queena Gonzalez, Thomas H Beckham, Robert North, Laurence Rhines, Jing Li, Amol Ghia, David Aten, Claudio Tatsui, Christopher Alvarez-Breckenridge

Faculty, Staff and Student Publications

Spinal metastases can result in severe neurologic compromise and decreased overall survival. Despite treatment advances, local disease progression is frequent, highlighting the need for novel therapies. Tumor treating fields (TTFields) impair tumor cell replication and are influenced by properties of surrounding tissue. We hypothesized that bone's dielectric properties will enhance TTFields-mediated suppression of tumor growth in spinal metastasis models. Computational modeling of TTFields intensity was performed following surgical resection of a spinal metastasis and demonstrated enhanced TTFields intensity within the resected vertebral body. Additionally, luciferase-tagged human KRIB osteosarcoma and A549 lung adenocarcinoma cell lines were cultured in demineralized bone grafts …

Targeted Inhibition Of Scfskp2 Confers Anti-Tumor Activities Resulting In A Survival Benefit In Osteosarcoma, Jichuan Wang, Alexander Ferrena, Ranxin Zhang, Swapnil Singh, Valentina Viscarret, Waleed Al-Harden, Osama Aldahamsheh, Hasibagan Borjihan, Amit Singla, Simon Yaguare, Janet Tingling, Xiaolin Zi, Yungtai Lo, Richard Gorlick, Edward L Schwartz, Hongling Zhao, Rui Yang, David S Geller, Deyou Zheng, Bang H Hoang

Faculty, Staff and Student Publications

Osteosarcoma(OS) is a highly aggressive bone cancer for which treatment has remained essentially unchanged for decades. Although OS is characterized by extensive genomic heterogeneity and instability, RB1 and TP53 have been shown to be the most commonly inactivated tumor suppressors in OS. We previously generated a mouse model with a double knockout (DKO) of Rb1 and Trp53 within cells of the osteoblastic lineage, which largely recapitulates human OS with nearly complete penetrance. SKP2 is a repression target of pRb and serves as a substrate recruiting subunit of the SCFSKP2 complex. In addition, SKP2 plays a central role in regulating the …

A New Perspective On Intervertebral Disc Calcification-From Bench To Bedside, Emanuel Novais, Rajkishen Narayanan, Jose Canseco, Koen Van De Wetering, Christopher Kepler, Alan Hilibrand, Alex Vaccaro, Makarand Risbud

Department of Orthopaedic Surgery Faculty Papers

Disc degeneration primarily contributes to chronic low back and neck pain. Consequently, there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis, ectopic calcification, herniation, or mixed phenotypes. Amongst these phenotypes, disc calcification is the least studied. Ectopic calcification, by definition, is the pathological mineralization of soft tissues, widely studied in the context of conditions that afflict vasculature, skin, and cartilage. Clinically, disc calcification is associated with poor surgical outcomes and back pain refractory to conservative treatment. It is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular …

Sirtuin 6 Activation Rescues The Age-Related Decline In Dna Damage Repair In Primary Human Chondrocytes, Michaela E. Copp, Jacqueline Shine, Hannon L. Brown, Kirti R. Nimmala, Oliver B. Hansen, Susan Chubinskaya, John A. Collins, Richard F. Loeser, Brian O. Diekman

Department of Orthopaedic Surgery Faculty Papers

While advanced age is widely recognized as the greatest risk factor for osteoarthritis (OA), the biological mechanisms behind this connection remain unclear. Previous work has demonstrated that chondrocytes from older cadaveric donors have elevated levels of DNA damage as compared to chondrocytes from younger donors. The purpose of this study was to determine whether a decline in DNA repair efficiency is one explanation for the accumulation of DNA damage with age, and to quantify the improvement in repair with activation of Sirtuin 6 (SIRT6). After acute damage with irradiation, DNA repair was shown to be more efficient in chondrocytes from …

Corneal Wound Healing In The Presence Of Antifibrotic Antibody Targeting Collagen Fibrillogenesis: A Pilot Study, Zeba A. Syed, Tatyana Milman, Jolanta Fertala, Andrzej Steplewski, Andrzej Fertala

Department of Orthopaedic Surgery Faculty Papers

Highly organized collagen fibrils interlacing with proteoglycans form the crucial architecture of the cornea and facilitate its transparency. Corneal scarring from accidental injury, surgery, or infection alters this highly organized tissue, causing severe consequences, including blindness. There are no pharmacological or surgical methods to effectively and safely treat excessive corneal scarring. Thus, we tested the anticorneal scarring utility of a rationally designed anticollagen antibody (ACA) whose antifibrotic effects have already been demonstrated in nonocular models. Utilizing a rabbit model with an incisional corneal wound, we analyzed ACA’s effects on forming collagen and proteoglycan-rich extracellular matrices in scar neotissue. We used …

Loss Of Function Mutation In Ank Causes Aberrant Mineralization And Acquisition Of Osteoblast-Like-Phenotype By The Cells Of The Intervertebral Disc, Takashi Ohnishi, Victoria Tran, Kimheak Sao, Pranay Ramteke, William Querido, Ruteja A. Barve, Koen Van De Wetering, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

Pathological mineralization of intervertebral disc is debilitating and painful and linked to disc degeneration in a subset of human patients. An adenosine triphosphate efflux transporter, progressive ankylosis (ANK) is a regulator of extracellular inorganic pyrophosphate levels and plays an important role in tissue mineralization. However, the function of ANK in intervertebral disc has not been fully explored. Herein we analyzed the spinal phenotype of Ank mutant mice (ank/ank) with attenuated ANK function. Micro-computed tomography and histological analysis showed that loss of ANK function results in the aberrant annulus fibrosus mineralization and peripheral disc fusions with cranial to caudal progression in …

A Parathyroid Hormone/Salt-Inducible Kinase Signaling Axis Controls Renal Vitamin D Activation And Organismal Calcium Homeostasis, Sung-Hee Yoon, Mark B Meyer, Carlos Arevalo, Murat Tekguc, Chengcheng Zhang, Jialiang S Wang, Christian D Castro Andrade, Katelyn Strauss, Tadatoshi Sato, Nancy A Benkusky, Seong Min Lee, Rebecca Berdeaux, Marc Foretz, Thomas B Sundberg, Ramnik J Xavier, Charles H Adelmann, Daniel J Brooks, Anthony Anselmo, Ruslan I Sadreyev, Ivy A Rosales, David E Fisher, Navin Gupta, Ryuji Morizane, Anna Greka, J Wesley Pike, Michael Mannstadt, Marc N Wein

Faculty, Staff and Student Publications

The renal actions of parathyroid hormone (PTH) promote 1,25-vitamin D generation; however, the signaling mechanisms that control PTH-dependent vitamin D activation remain unknown. Here, we demonstrated that salt-inducible kinases (SIKs) orchestrated renal 1,25-vitamin D production downstream of PTH signaling. PTH inhibited SIK cellular activity by cAMP-dependent PKA phosphorylation. Whole-tissue and single-cell transcriptomics demonstrated that both PTH and pharmacologic SIK inhibitors regulated a vitamin D gene module in the proximal tubule. SIK inhibitors increased 1,25-vitamin D production and renal Cyp27b1 mRNA expression in mice and in human embryonic stem cell–derived kidney organoids. Global- and kidney-specific Sik2/Sik3 mutant mice showed Cyp27b1 upregulation, …

Microbubble Cavitation Restores Staphylococcus Aureus Antibiotic Susceptibility In Vitro And In A Septic Arthritis Model, Neil Zhao, Dylan Curry, Rachel E Evans, Selin Isguven, Theresa A. Freeman, John R. Eisenbrey, Flemming Forsberg, Jessica M Gilbertie, Sophie Boorman, Rachel Hilliard, Sana S. Dastgheyb, Priscilla Machado, Maria Stanczak, Marc I. Harwood, Antonia F Chen, Javad Parvizi, Irving Shapiro, Noreen J. Hickok, Thomas P Schaer

Department of Orthopaedic Surgery Faculty Papers

Treatment failure in joint infections is associated with fibrinous, antibiotic-resistant, floating and tissue-associated Staphylococcus aureus aggregates formed in synovial fluid (SynF). We explore whether antibiotic activity could be increased against Staphylococcus aureus aggregates using ultrasound-triggered microbubble destruction (UTMD), in vitro and in a porcine model of septic arthritis. In vitro, when bacterially laden SynF is diluted, akin to the dilution achieved clinically with lavage and local injection of antibiotics, amikacin and ultrasound application result in increased bacterial metabolism, aggregate permeabilization, and a 4-5 log decrease in colony forming units, independent of microbubble destruction. Without SynF dilution, amikacin + UTMD does …

Glut1 Is Redundant In Hypoxic And Glycolytic Nucleus Pulposus Cells Of The Intervertebral Disc, Shira N. Johnston, Elizabeth S. Silagi, Vedavathi Madhu, Duc H. Nguyen, Irving M. Shapiro, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

Glycolysis is central to homeostasis of nucleus pulposus (NP) cells in the avascular intervertebral disc. Since the glucose transporter, GLUT1, is a highly enriched phenotypic marker of NP cells, we hypothesized that it is vital for the development and postnatal maintenance of the disc. Surprisingly, primary NP cells treated with 2 well-characterized GLUT1 inhibitors maintained normal rates of glycolysis and ATP production, indicating intrinsic compensatory mechanisms. We showed in vitro that NP cells mitigated GLUT1 loss by rewiring glucose import through GLUT3. Of note, we demonstrated that substrates, such as glutamine and palmitate, did not compensate for glucose restriction resulting …

In Vivo Measurement Of Intradiscal Pressure Changes Related To Thrust And Non-Thrust Spinal Manipulation In An Animal Model: A Pilot Study, William R Reed, Michael A K Liebschner, Carla R Lima, Harshvardhan Singh, Christopher P Hurt, Daniel F Martins, James M Cox, Maruti R Gudavalli

Faculty, Staff and Students Publications

BACKGROUND: The intervertebral disc is a known back pain generator and is frequently the focus of spinal manipulative therapy evaluation and treatment. The majority of our current knowledge regarding intradiscal pressure (IDP) changes related to spinal manual therapy involves cadaveric studies with their inherent limitations. Additional in vivo animal models are needed to investigate intervertebral disc physiological and molecular mechanisms related to spinal manipulation and spinal mobilization treatment for low back disorders.

METHODS: Miniature pressure catheters (Millar SPR-1000) were inserted into either the L4-L5 or L5-L6 intervertebral disc of 3 deeply anesthetized adult cats (Oct 2012-May 2013). Changes in IDP …

The Cgas-Sting Pathway Affects Vertebral Bone But Does Not Promote Intervertebral Disc Cell Senescence Or Degeneration, Olivia K. Ottone, C. James Kim, John A. Collins, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

The DNA-sensing cGAS-STING pathway promotes the senescence-associated secretory phenotype (SASP) and mediates type-I interferon inflammatory responses to foreign viral and bacterial DNA as well as self-DNA. Studies of the intervertebral disc in humans and mice demonstrate associations between aging, increased cell senescence, and disc degeneration. Herein we assessed the role of STING in SASP promotion in STING gain- (N153S) and loss-of-function mouse models. N153S mice evidenced elevated circulating levels of proinflammatory markers including IL-1β, IL-6, and TNF-α, showed elevated monocyte and macrophage abundance in the vertebral marrow, and exhibited a mild trabecular and cortical bone phenotype in caudal vertebrae. Interestingly, …

Evaluation Of Bone Formation On Orthopedic Implant Surfaces Using An Ex-Vivo Bone Bioreactor System, Rupak Dua, Hugh Jones, Philip C Noble

Faculty, Staff and Student Publications

Recent advances in materials and manufacturing processes have allowed the fabrication of intricate implant surfaces to facilitate bony attachment. However, refinement and evaluation of these new design strategies are hindered by the cost and complications of animal studies, particularly during early iterations in the development process. To address this problem, we have previously constructed and validated an ex-vivo bone bioreactor culture system that can maintain the viability of bone samples for an extended period ex-vivo. In this study, we investigated the mineralization of a titanium wire mesh scaffold under both static and dynamic culturing using our ex vivo bioreactor system. …

Long-Term Treatment With Senolytic Drugs Dasatinib And Quercetin Ameliorates Age-Dependent Intervertebral Disc Degeneration In Mice, Emanuel J Novais, Victoria Tran, Shira N Johnston, Kayla R Darris, Alex J Roupas, Garrett A Sessions, Irving Shapiro, Brian O Diekman, Makarand V Risbud

Department of Orthopaedic Surgery Faculty Papers

Intervertebral disc degeneration is highly prevalent within the elderly population and is a leading cause of chronic back pain and disability. Due to the link between disc degeneration and senescence, we explored the ability of the Dasatinib and Quercetin drug combination (D + Q) to prevent an age-dependent progression of disc degeneration in mice. We treated C57BL/6 mice beginning at 6, 14, and 18 months of age, and analyzed them at 23 months of age. Interestingly, 6- and 14-month D + Q cohorts show lower incidences of degeneration, and the treatment results in a significant decrease in senescence markers p16INK4a, …

What Are Biofilms?, Noreen J. Hickok

Department of Orthopaedic Surgery Faculty Papers

No abstract provided.

Effect Of Hemiepiphysiodesis On The Growth Plate: The Histopathological Changes And Mechanism Exploration Of Recurrence In Mini Pig Model., Jing Ding, Jin He, Zhi-Qiang Zhang, Zhen-Kai Wu, Fang-Chun Jin

Manuscripts, Articles, Book Chapters and Other Papers

Purpose: Hemiepiphysiodesis has been widely used to correct angular deformity of long bone in immature patients. However, there is a limited knowledge about the biomechanical effect of this technique on the histopathological changes of the growth plate and the mechanism of recurrence of malformation after implant removal. We aimed to evaluate the biomechanical effect of hemiepiphysiodesis on the histopathological changes of the growth plate and the mechanism of recurrence of malformation after implant removal in Bama miniature pigs, and to explore the role of asymmetric stress during this procedure.

Methods: Eight 3-month-old male Bama miniature pigs sustained surgeries on the …

Tnf-Α Promotes Nuclear Enrichment Of The Transcription Factor Tonebp/Nfat5 To Selectively Control Inflammatory But Not Osmoregulatory Responses In Nucleus Pulposus Cells., Zariel I. Johnson, Alexandra C. Doolittle, Joseph W. Snuggs, Irving M. Shapiro, Christine L. Le Maitre, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

Intervertebral disc degeneration (IDD) causes chronic back pain and is linked to production of proinflammatory molecules by nucleus pulposus (NP) and other disc cells. Activation of tonicity-responsive enhancer-binding protein (TonEBP)/NFAT5 by non-osmotic stimuli, including proinflammatory molecules, occurs in cells involved in immune response. However, whether inflammatory stimuli activate TonEBP in NP cells and whether TonEBP controls inflammation during IDD is unknown. We show that TNF-α, but not IL-1β or LPS, promoted nuclear enrichment of TonEBP protein. However, TNF-α-mediated activation of TonEBP did not cause induction of osmoregulatory genes. RNA sequencing showed that 8.5% of TNF-α transcriptional responses were TonEBP-dependent and …

Inhibition Of Apoptosis Signal-Regulating Kinase 1 Alters The Wound Epidermis And Enhances Auricular Cartilage Regeneration., Qian-Shi Zhang, Deepa S. Kurpad, My G. Mahoney, Marla J. Steinbeck, Theresa A. Freeman

Department of Orthopaedic Surgery Faculty Papers

Why regeneration does not occur in mammals remains elusive. In lower vertebrates, epimorphic regeneration of the limb is directed by the wound epidermis, which controls blastema formation to promote regrowth of the appendage. Herein, we report that knockout (KO) or inhibition of Apoptosis Signal-regulated Kinase-1 (ASK1), also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5), after full thickness ear punch in mice prolongs keratinocyte activation within the wound epidermis and promotes regeneration of auricular cartilage. Histological analysis showed the ASK1 KO ears displayed enhanced protein markers associated with blastema formation, hole closure and regeneration of auricular cartilage. At seven …

In Vivo Evaluation Of Stem Cell Aggregates On Osteochondral Regeneration., Banupriya Sridharan, Amy D. Laflin, Michael A. Holtz, Donna M. Pacicca, Nicholas K. Wischmeier, Michael S. Detamore

Manuscripts, Articles, Book Chapters and Other Papers

To date, many osteochondral regenerative approaches have utilized varied combinations of biocompatible materials and cells to engineer cartilage. Even in cell-based approaches, to date, no study has utilized stem cell aggregates alone for regenerating articular cartilage. Thus, the purpose of this study was to evaluate the performance of a novel stem cell-based aggregate approach in a fibrin carrier to regenerate osteochondral defects in the Sprague-Dawley rat trochlear groove model. Two different densities of rat bone marrow mesenchymal stem cell (rBMSC) aggregates were fabricated by the hanging drop technique. At 8 weeks, the cell aggregates supported the defects and served as …

Chemical Modification Of Extracellular Matrix By Cold Atmospheric Plasma-Generated Reactive Species Affects Chondrogenesis And Bone Formation., Peter Eisenhauer, Natalie Chernets, You Song, Danil Dobrynin, Nancy Pleshko, Marla J Steinbeck, Theresa A. Freeman

Department of Orthopaedic Surgery Faculty Papers

The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or …

Understanding Nucleus Pulposus Cell Phenotype: A Prerequisite For Stem Cell Based Therapies To Treat Intervertebral Disc Degeneration., Hyowon Choi, Zariel I. Johnson, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

Intervertebral disc (IVD) degeneration and associated low back pain (LBP) remains a major burden to our society without significant improvements in treatment strategies or patient's quality of life. While the recent cell-transplantation studies for treatment of degenerative disc disease have shown promising results, to better gauge the success and functional outcomes of these therapies, it is crucial to understand if transplanted cells give rise to healthy nucleus pulposus (NP) tissue. NP cell phenotype is unique and is defined by expression of a characteristic set of markers that reflect specialized physiology and function. This review summarizes phenotypic markers that mirror the …