Biomedical Engineering and Bioengineering Commons^™

Growth Plate Cartilage: Understanding The Contribution Of Adhesion To Column Formation And Matrix Structure, Sydney E. Greer

Theses & Dissertations

Throughout fetal and adolescent development, bone growth is regulated by fine-tuned and controlled maturation of chondrocytes through a cartilaginous template called the growth plate. Bone growth rate is controlled through cell enlargement and extracellular matrix deposition, while the polarized arrangement of proliferative chondrocytes into columns aligned with the long axis of the bone potentiate growth. Chondrocytes are surrounded by a complex three-dimensional arrangement of matrix molecules, all of which are secreted by chondrocytes and assembled/remodeled to support the biological functions of the cell. Adhesion receptors found on the cell membrane of chondrocytes are crucial to the organization of matrix proteins …

Mobile, Biosensor Technology For Measuring Joint-Level Human Motion, Matthew Mcmanigal

Theses & Dissertations

The measurement of three-dimensional knee joint angles can predict both anterior cruciate ligament (ACL) injuries and the risk of developing early knee osteoarthritis. However, knee joint angle assessment is currently limited, due to the lack of validated wearable and untethered technologies that can be deployed in natural environments and rural or community settings. To address this challenge, this thesis project aimed to 1) develop a fully untethered, wearable electronic device to measure knee joint angles during natural human movement and 2) test the accuracy of the device to collect sagittal knee joint angles during dynamic activities of human movement. For …

Development Of Polymeric Cxcr4 Targeting Carriers For Sirna Delivery To Treat Acute Kidney Injury, Weimin Tang

Theses & Dissertations

Acute kidney injury (AKI) is a major kidney disease that is characterized by a sudden loss of renal function which manifests by a decrease in urine output and an increase in serum creatinine. AKI is a global healthcare burden associated with high morbidity, mortality, and increasing cost. Currently there are no effective pharmacological treatments available. Apoptosis induced by p53 has been demonstrated as an important pathological mechanism for the development of AKI. Meanwhile, CXCR4/SDF-1 axis has been associated with the inflammation during AKI, and CXCR4 is overexpressed on injured tubules. This dissertation hypothesized that polycations with CXCR4 targeting ability could …

The Rotator Cuff Tendon-To-Bone Interface: Maturation, Aging, And 3d Bioprinting For Regeneration, Xiping Jiang

Theses & Dissertations

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area with a high prevalence for the elderly population. In addition, regeneration of the gradient structure of the enthesis is still a significant clinical challenge. Our studies aim to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging, and develop a novel therapeutic method using three-dimensional (3D) bioprinting technique to regenerate a functional enthesis. Striking variations of the entheses were observed both histologically and biomechanically during the maturation process. The histological features did not show many differences at the insertion site …

Is The Walking Pattern Similar Between Slope Walking And Obstacle Negotiation?, Jiani Lu

Theses & Dissertations

Studying biomechanical characteristics of human motion sheds light on the motor control strategies in the central nervous system. Slope walking and obstacle negotiation appear to have some similarities in control strategies based on subjective observation, but these two motions have never been compared objectively in biomechanics literature. This study aimed to investigate the similarities between obstacle negotiation and slope walking in kinematics and muscle activity. The similarities were determined by the correlation of the maximum heel elevation and muscle co-activation index between obstacle negotiation and inclined treadmill walking. The strength of correlation was compared in four different pairs of conditions: …

Development Of Fluorescent Hyaluronic Acid Nanoparticles For Intraoperative Tumor Detection, Nicholas E. Wojtynek

Theses & Dissertations

Surgical resection remains to be the primary treatment for the majority of solid tumors, including breast cancer. The complete removal of the primary tumor, local metastases, and metastatic lymph nodes dramatically improve a patient’s treatment outcome and prognosis. Nevertheless, surgeons are limited to tactile and visual cues in distinguishing malignant and healthy tissue. This can result in a positive surgical margin (PSM), which occurs when tumor goes undetected and is left behind in the surgical cavity. PSMs decreases a patient’s prognosis and necessitate additional treatment in the form of surgery, radiation, and chemotherapy. An emerging imaging modality, known as fluorescence-guided …

Human Islet Response To Selected Type 1 Diabetes-Associated Bacteria: A Transcriptome-Based Study, Ahmed M. Abdellatif, Heather Jensen Smith, Robert Z. Harms, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Type 1 diabetes (T1D) is a chronic autoimmune disease that results from destruction of pancreatic β-cells. T1D subjects were recently shown to harbor distinct intestinal microbiome profiles. Based on these findings, the role of gut bacteria in T1D is being intensively investigated. The mechanism connecting intestinal microbial homeostasis with the development of T1D is unknown. Specific gut bacteria such as Bacteroides dorei (BD) and Ruminococcus gnavus (RG) show markedly increased abundance prior to the development of autoimmunity. One hypothesis is that these bacteria might traverse the damaged gut barrier, and their constituents elicit a response from human islets that causes …

Towards An In Vitro Model Of Testing Osteoblast Cellular Function In Contact With Various Surfaces, Raheleh Miralami

Theses & Dissertations

Past studies have shown that the success of total joint replacements depends on the biocompatibility of orthopaedic materials, which can be improved by modifying the implant surface. However, the exact roles of these modifications and their effective mechanisms are poorly understood. The objective of this study was to develop and evaluate a model system to investigate the impact of nano-structured surfaces, produced by the ion beam-assisted deposition (IBAD) technique, on biomarkers of osteointegration using an in vitro model. The IBAD technique was employed to deposit zirconium oxide (ZrO₂), Titanium oxide (TiO₂), and Titanium (Ti) nano-films on …

A Study Of Acoustically Activated Nanodroplets, Songita Choudhury

Theses & Dissertations

Current treatment of acute myocardial infarction (AMI), which is the main pathophysiological event leading to death in the United States, has advanced considerably with the introduction of emergent percutaneous interventions, but there remains an urgent need for novel techniques to rapidly and accurately detect infarcted or ischemic tissue that results from AMI. Ultrasound contrast agents, also known as microbubbles (MB), have become commonplace in echocardiography. However, MBs are purely intravascular tracers and unable to cross endothelial barriers due to size. The limitations of MBs, namely size and short circulation times within the human body, led to the development of phase-change …

Determinants Of Multi-Scale Patterning In Growth Plate Cartilage, Alek Erickson

Theses & Dissertations

ABSTRACT

Functional architectures of complex adaptive systems emerge by dynamic control over properties of individual components. During skeletal development, growth plate cartilage matches bone geometries to body plan requisites by spatiotemporally regulating chondrocyte actions. Bone growth potential is managed by the proximodistal patterning of chondrocyte populations into differentiation zones, while growth vectors are specified by the unique columnar arrangement of clonal groups. Chondrocyte organization at both tissue and cell levels is influenced by a cartilage-wide communication network that relies on zone-specific release and interpretation of paracrine signals. Despite genetic characterization of signaling interactions necessary for cartilage maturation, the regulatory mechanisms …

Altered Cd161bright Cd8+ Mucosal Associated Invariant T (Mait)-Like Cell Dynamics And Increased Differentiation States Among Juvenile Type 1 Diabetics., Robert Z. Harms, Kristina M. Lorenzo, Kevin P. Corley, Monina S. Cabrera, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Type 1A diabetes (T1D) is believed to be caused by immune-mediated destruction of β-cells, but the immunological basis for T1D remains controversial. Microbial diversity promotes the maturation and activation of certain immune subsets, including CD161bright CD8+ mucosal associated invariant T (MAIT) cells, and alterations in gut mucosal responses have been reported in type 1 diabetics (T1Ds). We analyzed T cell populations in peripheral blood leukocytes from juvenile T1Ds and healthy controls. We found that proportion and absolute number of MAIT cells were similar between T1Ds and controls. Furthermore, while MAIT cell proportions increased with age among healthy controls, this trend …

Methamphetamine Administration Targets Multiple Immune Subsets And Induces Phenotypic Alterations Suggestive Of Immunosuppression., Robert Z. Harms, Brenda M. Morsey, Craig W. Boyer, Howard S. Fox, Nora E. Sarvetnick

Journal Articles: Regenerative Medicine

Methamphetamine (Meth) is a widely abused stimulant and its users are at increased risk for multiple infectious diseases. To determine the impact of meth on the immune system, we utilized a murine model that simulates the process of meth consumption in a typical addict. Our phenotypic analysis of leukocytes from this dose escalation model revealed that meth affected key immune subsets. Meth administration led to a decrease in abundance of natural killer (NK) cells and the remaining NK cells possessed a phenotype suggesting reduced responsiveness. Dendritic cells (DCs) and Gr-1(high) monocytes/macrophages were also decreased in abundance while Gr-1(low) monocytes/macrophages appear …

Differential Il-21 Signaling In Apcs Leads To Disparate Th17 Differentiation In Diabetes-Susceptible Nod And Diabetes-Resistant Nod.Idd3 Mice., Sue M. Liu, David H. Lee, Jenna M. Sullivan, Denise Chung, Anneli Jäger, Bennett O V. Shum, Nora E. Sarvetnick, Ana C. Anderson, Vijay K. Kuchroo

Journal Articles: Regenerative Medicine

Type 1 diabetes (T1D) is an autoimmune disease that shows familial aggregation in humans and likely has genetic determinants. Disease linkage studies have revealed many susceptibility loci for T1D in mice and humans. The mouse T1D susceptibility locus insulin-dependent diabetes susceptibility 3 (Idd3), which has a homologous genetic interval in humans, encodes cytokine genes Il2 and Il21 and regulates diabetes and other autoimmune diseases; however, the cellular and molecular mechanisms of this regulation are still being elucidated. Here we show that T cells from NOD mice produce more Il21 and less Il2 and exhibit enhanced Th17 cell generation compared with …

The Incidence Of Type-1 Diabetes In Nod Mice Is Modulated By Restricted Flora Not Germ-Free Conditions., Cecile King, Nora Sarvetnick

Journal Articles: Regenerative Medicine

In the NOD mouse, the incidence of type-1 diabetes is thought to be influenced by the degree of cleanliness of the mouse colony. Studies collectively demonstrate that exposure to bacterial antigen or infection in the neonatal period prevents diabetes [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], supporting the notion that immunostimulation can benefit the maturation of the postnatal immune system [11]. A widely accepted extrapolation from this data has been the notion that NOD mice maintained under germ-free conditions have an increased incidence of diabetes. However, evidence supporting this influential concept is surprisingly limited [12]. In this …

Il-21 Limits Peripheral Lymphocyte Numbers Through T Cell Homeostatic Mechanisms., Shrimati Datta, Nora E. Sarvetnick

Journal Articles: Regenerative Medicine

BACKGROUND: IL-21, a member of the common gamma-chain utilizing family of cytokines, participates in immune and inflammatory processes. In addition, the cytokine has been linked to autoimmunity in humans and rodents.

METHODOLOGY/PRINCIPAL FINDINGS: To investigate the mechanism whereby IL-21 affects the immune system, we investigated its role in T cell homeostasis and autoimmunity in both non-autoimmune C57BL/6 and autoimmune NOD mice. Our data indicate that IL-21R knockout C57BL/6 and NOD mice show increased size of their lymphocyte population and decreased homeostatic proliferation. In addition, our experimental results demonstrate that IL-21 inhibits T cell survival. These data suggest that IL-21 acts …

Resistance Of The Target Islet Tissue To Autoimmune Destruction Contributes To Genetic Susceptibility In Type 1 Diabetes., Natasha J. Hill, Aleksandr Stotland, Michelle Solomon, Patrick Secrest, Elizabeth Getzoff, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Type 1 diabetes occurs when self-reactive T lymphocytes destroy the insulin-producing islet beta cells of the pancreas. The defects causing this disease have often been assumed to occur exclusively in the immune system. We present evidence that genetic variation at the Idd9 diabetes susceptibility locus determines the resilience of the targets of autoimmunity, the islets, to destruction. Susceptible islets exhibit hyper-responsiveness to inflammatory cytokines resulting in enhanced cell death and increased expression of the death receptor Fas. Fas upregulation in beta cells is mediated by TNFR2, and colocalization of TNFR2 with the adaptor TRAF2 in NOD beta cells is altered. …

Identification And Expansion Of Pancreatic Stem/Progenitor Cells., You-Qing Zhang, Marcie Kritzik, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Pancreatic islet transplantation represents an attractive approach for the treatment of diabetes. However, the limited availability of donor islets has largely hampered this approach. In this respect, the use of alternative sources of islets such as the ex vivo expansion and differentiation of functional endocrine cells for treating diabetes has become the major focus of diabetes research. Adult pancreatic stem cells /progenitor cells have yet to be recognized because limited markers exist for their identification. While the pancreas has the capacity to regenerate under certain circumstances, questions where adult pancreatic stem/progenitor cells are localized, how they are regulated, and even …

The Stromal Cell-Derived Factor-1alpha/Cxcr4 Ligand-Receptor Axis Is Critical For Progenitor Survival And Migration In The Pancreas., Ayse G. Kayali, Kurt Van Gunst, Iain L. Campbell, Aleksandr Stotland, Marcie Kritzik, Guoxun Liu, Malin Flodström-Tullberg, You-Qing Zhang, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The SDF-1alpha/CXCR4 ligand/chemokine receptor pair is required for appropriate patterning during ontogeny and stimulates the growth and differentiation of critical cell types. Here, we demonstrate SDF-1alpha and CXCR4 expression in fetal pancreas. We have found that SDF-1alpha and its receptor CXCR4 are expressed in islets, also CXCR4 is expressed in and around the proliferating duct epithelium of the regenerating pancreas of the interferon (IFN) gamma-nonobese diabetic mouse. We show that SDF-1alpha stimulates the phosphorylation of Akt, mitogen-activated protein kinase, and Src in pancreatic duct cells. Furthermore, migration assays indicate a stimulatory effect of SDF-1alpha on ductal cell migration. Importantly, blocking …

Ccr4-Bearing T Cells Participate In Autoimmune Diabetes., Soon H. Kim, Mary M. Cleary, Howard S. Fox, Icos Coporation, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Chemokine receptor expression is exquisitely regulated on T cell subsets during the course of their migration to inflammatory sites. In the present study we demonstrate that CCR4 expression marks a pathogenic population of autoimmune T cells. CCR4 was found exclusively on memory CD4(+) T cells during the progression of disease in NOD mice. Cells expressing the CCR4 ligand TARC (thymus- and activation-regulated chemokine) were detected within infiltrated islets from prediabetic mice. Interestingly, neutralization of macrophage-derived chemokine (MDC) with Ab caused a significant reduction of CCR4-positive T cells within the pancreatic infiltrates and inhibited the development of insulitis and diabetes. Furthermore, …

Presented Antigen From Damaged Pancreatic Beta Cells Activates Autoreactive T Cells In Virus-Mediated Autoimmune Diabetes., Marc S. Horwitz, Alex Ilic, Cody Fine, Enrique Rodriguez, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The induction of autoimmunity by viruses has been attributed to numerous mechanisms. In mice, coxsackievirus B4 (CB4) induces insulin-dependent diabetes mellitus (IDDM) resembling the final step of disease progression in humans. The immune response following the viral insult clearly precipitates IDDM. However, the molecular pathway between viral infection and the subsequent activation of T cells specific for islet antigen has not been elucidated. These T cells could become activated through exposure to sequestered antigens released by damaged beta cells, or they could have responded to factors secreted by the inflammatory response itself. To distinguish between these possibilities, we treated mice …

A Defect In Interleukin 12-Induced Activation And Interferon Gamma Secretion Of Peripheral Natural Killer T Cells In Nonobese Diabetic Mice Suggests New Pathogenic Mechanisms For Insulin-Dependent Diabetes Mellitus., Marika Falcone, Brian Yeung, Lee Tucker, Enrique Rodriguez, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The function of natural killer T (NKT) cells in the immune system has yet to be determined. There is some evidence that their defect is associated with autoimmunity, but it is still unclear how they play a role in regulating the pathogenesis of T cell-mediated autoimmune diseases. It was originally proposed that NKT cells could control autoimmunity by shifting the cytokine profile of autoimmune T cells toward a protective T helper 2 cell (Th2) type. However, it is now clear that the major function of NKT cells in the immune system is not related to their interleukin (IL)-4 secretion. In …

Interferon Gamma (Ifn-Gamma) Is Necessary For The Genesis Of Acetylcholine Receptor-Induced Clinical Experimental Autoimmune Myasthenia Gravis In Mice., Balaji Balasa, Caishu Deng, Jae Lee, Linda M. Bradley, Dyanna K. Dalton, Premkumar Christadoss, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Experimental autoimmune myasthenia gravis (EAMG) is an animal model of human myasthenia gravis (MG). In mice, EAMG is induced by immunization with Torpedo californica acetylcholine receptor (AChR) in complete Freund's adjuvant (CFA). However, the role of cytokines in the pathogenesis of EAMG is not clear. Because EAMG is an antibody-mediated disease, it is of the prevailing notion that Th2 but not Th1 cytokines play a role in the pathogenesis of this disease. To test the hypothesis that the Th1 cytokine, interferon (IFN)-gamma, plays a role in the development of EAMG, we immunized IFN-gamma knockout (IFN-gko) (-/-) mice and wild-type (WT) …

Local Delivery Of Interleukin 4 By Retrovirus-Transduced T Lymphocytes Ameliorates Experimental Autoimmune Encephalomyelitis., Michael K. Shaw, James B. Lorens, Archana Dhawan, Richard Dalcanto, Harley Y. Tse, Alyssa B. Tran, Colleen Bonpane, Shanti L. Eswaran, Stefan Brocke, Nora Sarvetnick, Lawrence Steinman, Garry P. Nolan, C. Garrison Fathman

Journal Articles: Regenerative Medicine

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory autoimmune disease of the central nervous system which serves as a model for the human disease multiple sclerosis. We demonstrate here that encephalitogenic T cells, transduced with a retroviral gene, construct to express interleukin 4, and can delay the onset and reduce the severity of EAE when adoptively transferred to myelin basic protein-immunized mice. Thus, T lymphocytes transduced with retroviral vectors can deliver "regulatory cytokines" in a site-specific manner and may represent a viable therapeutic strategy for the treatment of autoimmune disease.

Ifn-Gamma, Igif, And Iddm., Nora Sarvetnick

Journal Articles: Regenerative Medicine

No abstract provided.

Mechanisms Of Cytokine-Mediated Localized Immunoprotection., Nora Sarvetnick

Journal Articles: Regenerative Medicine

No abstract provided.

Pancreatic Expression Of Interleukin-4 Abrogates Insulitis And Autoimmune Diabetes In Nonobese Diabetic (Nod) Mice., Regula Mueller, Troy Krahl, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Diabetes in nonobese diabetic (NOD) mice is a T cell-dependent autoimmune disease. The destructive activities of autoreactive T cells have been shown to be tightly regulated by effector molecules. In particular, T helper (Th) 1 cytokines have been linked to diabetes pathogenesis, whereas Th2 cytokines and the cells that release them have been postulated to be protective from disease. To test this hypothesis, we generated transgenic NOD mice that express interleukin (IL) 4 in their pancreatic beta cells under the control of the human insulin promoter. We found that transgenic NOD-IL-4 mice, both females and males, were completely protected from …

Il-10 Is Necessary And Sufficient For Autoimmune Diabetes In Conjunction With Nod Mhc Homozygosity., Myung-Shik Lee, Regula Mueller, Linda S. Wicker, Laurence B. Peterson, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Contrary to expectations based on in vitro experiments, we previously found that pancreatic IL-10 did not inhibit autoimmune diabetes but accelerated it in an MHC-dependent manner. Therefore, the ability of IL-10 to overcome the absence of all non-MHC diabetes susceptibility (Idd) alleles was studied in transgenic mice expressing pancreatic IL-10 backcrossed to B10.H2g7 congenic mice, which have no Idd alleles other than NOD MHC (H2g7). IL-10 transgenic backcross 1 (BC1) mice with H2g7/g7 haplotype developed clear-cut insulitis and diabetes, but neither transgenic mice with the H2g/b haplotype nor nontransgenic BC1 mice did so. Further implicating IL-10 in autoimmune diabetes, anti-IL-10 …

Myasthenia Gravis-Like Syndrome Induced By Expression Of Interferon Gamma In The Neuromuscular Junction., Danling Gu, Lise Wogensen, Nigel A. Calcutt, Chunyao Xia, Simin Zhu, John P. Merlie, Howard S. Fox, Jon Lindstrom, Henry C. Powell, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Abnormal humoral responses toward motor end plate constituents in muscle induce myasthenia gravis (MG). To study the etiology of this disease, and whether it could be induced by host defense molecules, we examined the consequences of interferon (IFN) gamma production within the neuromuscular junction of transgenic mice. The transgenic mice exhibited gradually increasing muscular weakness, flaccid paralysis, and functional disruption of the neuromuscular junction that was reversed after administration of an inhibitor of acetylcholinesterase, features which are strikingly similar to human MG. Furthermore, histological examination revealed infiltration of mononuclear cells and autoantibody deposition at motor end plates. Immunoprecipitation analysis indicated …

Sensitization To Self (Virus) Antigen By In Situ Expression Of Murine Interferon-Gamma., Myung-Shik Lee, Matthias Von Herrath, Hans Reiser, Michael B.A. Oldstone, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Autoimmune disease results from inflammatory destruction of tissues by aberrant self-reactive lymphocytes. We studied the autoimmune potential of T lymphocytes immunologically ignorant of viral antigens acting as self antigens and whether the host defense molecule IFN-gamma could stimulate these cells to cytotoxic competency. For this purpose, we produced double transgenic mice expressing pancreatic IFN-gamma as well as lymphocytic choriomeningitis virus (LCMV) nucleoprotein (NP) or glycoprotein (GP) antigen. 100% of the NP+/IFN-gamma+ mice became diabetic before 2 mo of age, while none of the NP single transgenic littermates and only 10% of IFN-gamma single transgenic littermates did. Strikingly, NP+/IFN-gamma+ mice spontaneously …

Production Of Interleukin 10 By Islet Cells Accelerates Immune-Mediated Destruction Of Beta Cells In Nonobese Diabetic Mice., Lise Wogensen, Myung-Shik Lee, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The T helper type 2 (Th2) cell product interleukin 10 (IL-10) inhibits the proliferation and function of Th1 lymphocytes and macrophages (M phi). The nonobese diabetic mouse strain (NOD/Shi) develops a M phi and T cell-dependent autoimmune diabetes that closely resembles human insulin-dependent diabetes mellitus (IDDM). The objective of the present study was to explore the consequences of localized production of IL-10 on diabetes development in NOD/Shi mice. Surprisingly, local production of IL-10 accelerated the onset and increased the prevalence of diabetes, since diabetes developed at 5-10 wk of age in 92% of IL-10 positive I-A beta g7/g7, I-E- mice …