Medicine and Health Sciences Commons^™

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 …

A Biologic-Device Combination Product Delivering Tumor-Derived Antigens Elicits Immunogenic Cell Death-Associated Immune Responses Against Glioblastoma, Christopher Cultrara, Christopher Uhl, Kenneth Kirby, Essam Abed Elrazaq, Amelia Zellander, David W. Andrews, Charles B. Scott, Lorenzo Galluzzi, Mark A. Exley, Jenny Zilberberg

Department of Neurosurgery Faculty Papers

Background IGV-001 is a personalized, autologous cancer cell-based immunotherapy conceived to deliver a tumor-derived antigenic payload in the context of immunostimulatory signals to patients with glioblastoma (GBM). IGV-001 consists of patient-derived GBM cells treated with an antisense oligodeoxynucleotide against insulin-like growth factor 1 receptor (IGF1R) and placed in proprietary biodiffusion chambers (BDCs). The BDCs are then exposed to 5–6 Gy radiation and implanted at abdominal sites for ~48 hours. IGV-001 has previously been shown to be generally safe with promising clinical activity in newly diagnosed GBM patients.

Methods Mouse (m) or human (h) variants of IGV-001 …

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 …

Lysosomal Lipid Peroxidation Regulates Tumor Immunity, Monika Bhardwaj, Jennifer J Lee, Amanda M Versace, Sandra L Harper, Aaron R Goldman, Mary Ann S Crissey, Vaibhav Jain, Mahendra Pal Singh, Megane Vernon, Andrew E. Aplin, Seokwoo Lee, Masao Morita, Jeffrey D Winkler, Qin Liu, David W Speicher, Ravi K Amaravadi

Department of Surgery Faculty Papers

Lysosomal inhibition elicited by palmitoyl-protein thioesterase 1 (PPT1) inhibitors such as DC661 can produce cell death, but the mechanism for this is not completely understood. Programmed cell death pathways (autophagy, apoptosis, necroptosis, ferroptosis, and pyroptosis) were not required to achieve the cytotoxic effect of DC661. Inhibition of cathepsins, or iron or calcium chelation, did not rescue DC661-induced cytotoxicity. PPT1 inhibition induced lysosomal lipid peroxidation (LLP), which led to lysosomal membrane permeabilization and cell death that could be reversed by the antioxidant N-acetylcysteine (NAC) but not by other lipid peroxidation antioxidants. The lysosomal cysteine transporter MFSD12 was required for intralysosomal transport …

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 …

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, …

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, …

Cigarette Smoke Initiates Oxidative Stress-Induced Cellular Phenotypic Modulation Leading To Cerebral Aneurysm Pathogenesis., Robert M. Starke, John W. Thompson, Muhammad S. Ali, Crissey L. Pascale, Alejandra Martinez Lege, Dale Ding, Nohra Chalouhi, David M. Hasan, Pascal Jabbour, Gary K Owens, Michal Toborek, Joshua M. Hare, Aaron S. Dumont

Department of Neurosurgery Faculty Papers

OBJECTIVE: Cigarette smoke exposure (CSE) is a risk factor for cerebral aneurysm (CA) formation, but the molecular mechanisms are unclear. Although CSE is known to contribute to excess reactive oxygen species generation, the role of oxidative stress on vascular smooth muscle cell (VSMC) phenotypic modulation and pathogenesis of CAs is unknown. The goal of this study was to investigate whether CSE activates a NOX (NADPH oxidase)-dependent pathway leading to VSMC phenotypic modulation and CA formation and rupture.

APPROACH AND RESULTS: In cultured cerebral VSMCs, CSE increased expression of NOX1 and reactive oxygen species which preceded upregulation of proinflammatory/matrix remodeling genes …

Posttranscriptional Regulation Of Parg Mrna By Hur Facilitates Dna Repair And Resistance To Parp Inhibitors, Saswati N. Chand, Mahsa Zarei, M. J. Schiewer, Akshay R. Sanan, Carmella Romeo, Shruti Lal, Joseph A. Cozzitorto, Avinoam Nevler, Laura Scolaro, Eric R. Londin, Wei Jiang, Nicole Meisner-Kober, Michael J. Pishvaian, Karen E. Knudsen, Charles Yeo, John M Pascal, Jordan M. Winter, Jonathan R. Brody

Department of Surgery Faculty Papers

The majority of pancreatic ductal adenocarcinomas (PDAC) rely on the mRNA stability factor HuR (ELAV-L1) to drive cancer growth and progression. Here, we show that CRISPR-Cas9–mediated silencing of the HuR locus increases the relative sensitivity of PDAC cells to PARP inhibitors (PARPi). PDAC cells treated with PARPi stimulated translocation of HuR from the nucleus to the cytoplasm, specifically promoting stabilization of a new target, poly (ADP-ribose) glycohydrolase (PARG) mRNA, by binding a unique sequence embedded in its 3⁰ untranslated region. HuR-dependent upregulation of PARG expression facilitated DNA repair via hydrolysis of polyADP-ribose on related repair proteins. Accordingly, strategies to …

Crispr Knockout Of The Hur Gene Causes A Xenograft Lethal Phenotype., Shruti Lal, Edwin C, Cheung, Mahsa Zarei, Ranjan Preet, Saswati N. Chand, Nicole C. Mambelli-Lisboa, Carmella Romeo, Matthew C. Stout, Eric Londin, Austin Goetz, Cinthya Y. Lowder, Avinoam Nevler, Charles Yeo, Paul M. Campbell, Jordan M. Winter, Dan A. Dixon, Jonathan Brody

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related deaths in the United States, whereas colorectal cancer is the third most common cancer. The RNA-binding protein HuR (ELAVL1) supports a pro-oncogenic network in gastrointestinal (GI) cancer cells through enhanced HuR expression. Using a publically available database, HuR expression levels were determined to be increased in primary PDA and colorectal cancer tumor cohorts as compared with normal pancreas and colon tissues, respectively. CRISPR/Cas9 technology was successfully used to delete the HuR gene in both PDA (MIA PaCa-2 and Hs 766T) and colorectal cancer (HCT116) cell lines. HuR deficiency has …

Iv And Ip Administration Of Rhodamine In Visualization Of Wbc-Bbb Interactions In Cerebral Vessels., Zachary Wilmer Reichenbach, Hongbo Li, John P. Gaughan, Melanie B. Elliott, Ronald Tuma

Department of Neurosurgery Faculty Papers

Epi-illuminescence intravital fluorescence microscopy has been employed to study leukocyte-endothelial interactions in a number of brain pathologies. Historically, dyes such as Rhodamine 6G have been injected intravenously. However, intravenous injections can predispose experimental animals to a multitude of complications and requires a high degree of technical skill. Here, we study the efficacy of injecting Rhodamine 6G into the peritoneum (IP) for the purpose of analyzing leukocyte-endothelial interactions through a cranial window during real time intravital microscopy. After examining the number of rolling and adherent leukocytes through a cranial window, we found no advantage to the intravenous injection (IV). Additionally, we …

Potent Inhibition Of Heterotopic Ossification By Nuclear Retinoic Acid Receptor-Γ Agonists., Kengo Shimono, Wei-En Tung, Christine Macolino, Amber Hsu-Tsai Chi, Johanna H Didizian, Christina Mundy, Roshantha A Chandraratna, Yuji Mishina, Motomi Enomoto-Iwamoto, Maurizio Pacifici, Masahiro Iwamoto

Department of Orthopaedic Surgery Faculty Papers

Heterotopic ossification consists of ectopic bone formation within soft tissues after surgery or trauma. It can have debilitating consequences, but there is no definitive cure. Here we show that heterotopic ossification was essentially prevented in mice receiving a nuclear retinoic acid receptor-γ (RAR-γ) agonist. Side effects were minimal, and there was no significant rebound effect. To uncover the mechanisms of these responses, we treated mouse mesenchymal stem cells with an RAR-γ agonist and transplanted them into nude mice. Whereas control cells formed ectopic bone masses, cells that had been pretreated with the RAR-γ agonist did not, suggesting that they had …

Interaction Of The Mu-Opioid Receptor With Gpr177 (Wntless) Inhibits Wnt Secretion: Potential Implications For Opioid Dependence., Jay Jin, Saranya Kittanakom, Victoria Wong, Beverly A S Reyes, Elisabeth J Van Bockstaele, Igor Stagljar, Wade Berrettini, Robert Levenson

Department of Neurosurgery Faculty Papers

BACKGROUND: Opioid agonist drugs produce analgesia. However, long-term exposure to opioid agonists may lead to opioid dependence. The analgesic and addictive properties of opioid agonist drugs are mediated primarily via the mu-opioid receptor (MOR). Opioid agonists appear to alter neuronal morphology in key brain regions implicated in the development of opioid dependence. However, the precise role of the MOR in the development of these neuronal alterations remains elusive. We hypothesize that identifying and characterizing novel MOR interacting proteins (MORIPs) may help to elucidate the underlying mechanisms involved in the development of opioid dependence. RESULTS: GPR177, the mammalian ortholog of Drosophila …