scholarly journals Mitochondria in Injury, Inflammation and Disease of Articular Skeletal Joints

2021 ◽  
Vol 12 ◽  
Author(s):  
James Orman Early ◽  
Lauren E. Fagan ◽  
Annie M. Curtis ◽  
Oran D. Kennedy
Keyword(s):  
Inflammatory Response ◽  
Immune Cells ◽  
Tissue Damage ◽  
Tissue Injury ◽  
Expression Profiles ◽  
Healing Process ◽  
Biological Response ◽  
Shear Stresses ◽  
Joint Injury ◽  
Joint Tissue

Inflammation is an important biological response to tissue damage caused by injury, with a crucial role in initiating and controlling the healing process. However, dysregulation of the process can also be a major contributor to tissue damage. Related to this, although mitochondria are typically thought of in terms of energy production, it has recently become clear that these important organelles also orchestrate the inflammatory response via multiple mechanisms. Dysregulated inflammation is a well-recognised problem in skeletal joint diseases, such as rheumatoid arthritis. Interestingly osteoarthritis (OA), despite traditionally being known as a ‘non-inflammatory arthritis’, now appears to involve an element of chronic inflammation. OA is considered an umbrella term for a family of diseases stemming from a range of aetiologies (age, obesity etc.), but all with a common presentation. One particular OA sub-set called Post-Traumatic OA (PTOA) results from acute mechanical injury to the joint. Whether the initial mechanical tissue damage, or the subsequent inflammatory response drives disease, is currently unclear. In the former case; mechanobiological properties of cells/tissues in the joint are a crucial consideration. Many such cell-types have been shown to be exquisitely sensitive to their mechanical environment, which can alter their mitochondrial and cellular function. For example, in bone and cartilage cells fluid-flow induced shear stresses can modulate cytoskeletal dynamics and gene expression profiles. More recently, immune cells were shown to be highly sensitive to hydrostatic pressure. In each of these cases mitochondria were central to these responses. In terms of acute inflammation, mitochondria may have a pivotal role in linking joint tissue injury with chronic disease. These processes could involve the immune cells recruited to the joint, native/resident joint cells that have been damaged, or both. Taken together, these observations suggest that mitochondria are likely to play an important role in linking acute joint tissue injury, inflammation, and long-term chronic joint degeneration - and that the process involves mechanobiological factors. In this review, we will explore the links between mechanobiology, mitochondrial function, inflammation/tissue-damage in joint injury and disease. We will also explore some emerging mitochondrial therapeutics and their potential for application in PTOA.

Inflammation: a role for NR4A orphan nuclear receptors?

2011 ◽  
Vol 39 (2) ◽  
pp. 688-693 ◽  
Author(s):  
Jason P. McMorrow ◽  
Evelyn P. Murphy
Keyword(s):  
Inflammatory Response ◽  
Nuclear Receptors ◽  
Acute Phase ◽  
Immune Cells ◽  
Inflammatory Responses ◽  
Acute Phase Proteins ◽  
Tissue Injury ◽  
Chronic Phase ◽  
Psoriatic Skin ◽  
Orphan Nuclear Receptors

Inflammation is paradoxical; it is essential for protection following biological, chemical or physical stimuli, but inappropriate or misdirected inflammation is responsible for tissue injury in a variety of inflammatory diseases. The polarization of immune cells is critical in controlling the stages of inflammatory response. The acute phase of inflammation is characterized by a T-lymphocyte:Th2 cytokine profile and involves a co-ordinated migration of immune cells to the site of injury where production of cytokines and acute-phase proteins brings about healing. However, persistent inflammation can result in inappropriate and prolonged T-lymphocyte:Th1 cytokine-mediated action and reaction of self-molecules, leading to a chronic phase in diseases such as RA (rheumatoid arthritis), Ps (psoriasis) and atherosclerosis. The inflammatory response is also controlled by activated macrophage cells, with classically activated (M1) cells producing a wide variety of pro-inflammatory mediators, while alternatively activated (M2) macrophages participate in anti-inflammatory response. Members of the NR4A subfamily (NR4A1/NUR77, NR4A2/NURR1 and NR4A3/NOR1) of orphan NRs (nuclear receptors) have emerged as key transcriptional regulators of cytokine and growth factor action in diseases affecting our aging population. As ligand-independent and constitutively active receptors, the activity of these transcription factors is tightly controlled at the level of expression, post-translational modification and subcellular localization. NR4A subfamily members are aberrantly expressed in inflamed human synovial tissue, psoriatic skin, atherosclerotic lesions, lung and colorectal cancer cells. Significantly, prolonged or inappropriate inflammatory responses contribute to the pathogenesis of these diseases. In activated cells, NR4A receptors are rapidly and potently induced, suggesting that these receptors may act as important transcriptional mediators of inflammatory signals. NR4A receptors may contribute to the cellular processes that control inflammation, playing a critical part in the contribution of chronic inflammation or they may have a protective role, where they may mediate pro-resolution responses. Here, we will review the contribution of the NR4A orphan NRs to integration of cytokine signalling in inflammatory disorders.

scholarly journals Monocytes and macrophages in tissue repair: Implications for immunoregenerative biomaterial design

2016 ◽  
Vol 241 (10) ◽  
pp. 1084-1097 ◽  
Author(s):  
Molly E Ogle ◽  
Claire E Segar ◽  
Sraeyes Sridhar ◽  
Edward A Botchwey
Keyword(s):  
Inflammatory Response ◽  
Immune Cells ◽  
Tissue Repair ◽  
Tissue Injury ◽  
Critical Role ◽  
Myeloid Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Signaling Systems ◽  
Monocytes And Macrophages

Monocytes and macrophages play a critical role in tissue development, homeostasis, and injury repair. These innate immune cells participate in guiding vascular remodeling, stimulation of local stem and progenitor cells, and structural repair of tissues such as muscle and bone. Therefore, there is a great interest in harnessing this powerful endogenous cell source for therapeutic regeneration through immunoregenerative biomaterial engineering. These materials seek to harness specific subpopulations of monocytes/macrophages to promote repair by influencing their recruitment, positioning, differentiation, and function within a damaged tissue. Monocyte and macrophage phenotypes span a continuum of inflammatory (M1) to anti-inflammatory or pro-regenerative cells (M2), and their heterogeneous functions are highly dependent on microenvironmental cues within the injury niche. Increasing evidence suggests that division of labor among subpopulations of monocytes and macrophages could allow for harnessing regenerative functions over inflammatory functions of myeloid cells; however, the complex balance between necessary functions of inflammatory versus regenerative myeloid cells remains to be fully elucidated. Historically, biomaterial-based therapies for promoting tissue regeneration were designed to minimize the host inflammatory response; although, recent appreciation for the roles that innate immune cells play in tissue repair and material integration has shifted this paradigm. A number of opportunities exist to exploit known signaling systems of specific populations of monocytes/macrophages to promote repair and to better understand the biological and pathological roles of myeloid cells. This review seeks to outline the characteristics of distinct populations of monocytes and macrophages, identify the role of these cells within diverse tissue injury niches, and offer design criteria for immunoregenerative biomaterials given the intrinsic inflammatory response to their implantation.

scholarly journals New Insights into the Role of Peroxisome Proliferator-Activated Receptors in Regulating the Inflammatory Response after Tissue Injury

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Miriam D. Neher ◽  
Sebastian Weckbach ◽  
Markus S. Huber-Lang ◽  
Philip F. Stahel
Keyword(s):  
Inflammatory Response ◽  
Major Trauma ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Healing Process ◽  
Wound Healing Process ◽  
Peroxisome Proliferator ◽  
Ppar Agonists ◽  
Peroxisome Proliferator Activated Receptors

Major trauma results in a strong inflammatory response in injured tissue. This posttraumatic hyperinflammation has been implied in the adverse events leading to a breakdown of host defense mechanisms and ultimately to delayed organ failure. Ligands to peroxisome proliferator-activated receptors (PPARs) have recently been identified as potent modulators of inflammation in various acute and chronic inflammatory conditions. The main mechanism of action mediated by ligand binding to PPARs is the inhibition of the nuclear transcription factor NF-κB, leading to downregulation of downstream gene transcription, such as for genes encoding proinflammatory cytokines. Pharmacological PPAR agonists exert strong anti-inflammatory properties in various animal models of tissue injury, including central nervous system trauma, ischemia/reperfusion injury, sepsis, and shock. In addition, PPAR agonists have been shown to induce wound healing process after tissue trauma. The present review was designed to provide an up-to-date overview on the current understanding of the role of PPARs in the pathophysiology of the inflammatory response after major trauma. Therapeutic options for using recombinant PPAR agonists as pharmacological agents in the management of posttraumatic inflammation will be discussed.

scholarly journals The Roles of Immune Cells in the Pathogenesis of Fibrosis

2020 ◽  
Vol 21 (15) ◽  
pp. 5203 ◽  
Author(s):  
Enyu Huang ◽  
Na Peng ◽  
Fan Xiao ◽  
Dajun Hu ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Signaling Pathways ◽  
Immune Cells ◽  
Molecular Mechanisms ◽  
Tissue Injury ◽  
Adaptive Immune ◽  
Recent Advances ◽  
Adaptive Immune Cells ◽  
Stat Signaling ◽  
Fibrotic Diseases

Tissue injury and inflammatory response trigger the development of fibrosis in various diseases. It has been recognized that both innate and adaptive immune cells are important players with multifaceted functions in fibrogenesis. The activated immune cells produce various cytokines, modulate the differentiation and functions of myofibroblasts via diverse molecular mechanisms, and regulate fibrotic development. The immune cells exhibit differential functions during different stages of fibrotic diseases. In this review, we summarized recent advances in understanding the roles of immune cells in regulating fibrotic development and immune-based therapies in different disorders and discuss the underlying molecular mechanisms with a focus on mTOR and JAK-STAT signaling pathways.

scholarly journals Small GTPase-dependent regulation of leukocyte–endothelial interactions in inflammation

2018 ◽  
Vol 46 (3) ◽  
pp. 649-658 ◽  
Author(s):  
Julia Y. Chu ◽  
Barry McCormick ◽  
Sonja Vermeren
Keyword(s):  
Inflammatory Response ◽  
Cross Talk ◽  
Immune Cells ◽  
Inflammatory Mediators ◽  
Tissue Repair ◽  
Biological Response ◽  
Small Gtpases ◽  
Small Gtpase ◽  
Endothelial Lining ◽  
Neutrophil Extravasation

Inflammation is a complex biological response that serves to protect the body's tissues following harmful stimuli such as infection, irritation or injury and initiates tissue repair. At the start of an inflammatory response, pro-inflammatory mediators induce changes in the endothelial lining of the blood vessels and in leukocytes. This results in increased vascular permeability and increased expression of adhesion proteins, and promotes adhesion of leukocytes, especially neutrophils to the endothelium. Adhesion is a prerequisite for neutrophil extravasation and chemoattractant-stimulated recruitment to inflammatory sites, where neutrophils phagocytose and kill microbes, release inflammatory mediators and cross-talk with other immune cells to co-ordinate the immune response in preparation for tissue repair. Many signalling proteins are critically involved in the complex signalling processes that underpin the inflammatory response and cross-talk between endothelium and leukocytes. As key regulators of cell–cell and cell–substratum adhesion, small GTPases (guanosine triphosphatases) act as important controls of neutrophil-endothelial cell interactions as well as neutrophil recruitment to sites of inflammation. Here, we summarise key processes that are dependent upon small GTPases in leukocytes during these early inflammatory events. We place a particular focus on the regulation of integrin-dependent events and their control by Rho and Rap family GTPases as well as their regulators during neutrophil adhesion, chemotaxis and recruitment.

The Immune System Regulation in Sepsis: From Innate to Adaptive

2019 ◽  
Vol 20 (8) ◽  
pp. 799-816 ◽  
Author(s):  
Yue Qiu ◽  
Guo-wei Tu ◽  
Min-jie Ju ◽  
Cheng Yang ◽  
Zhe Luo
Keyword(s):  
Clinical Trials ◽  
Immune System ◽  
Systemic Inflammatory Response Syndrome ◽  
Inflammatory Response ◽  
Immune Cells ◽  
Current Knowledge ◽  
Systemic Inflammatory Response ◽  
Immune System Regulation

Sepsis, which is a highly heterogeneous syndrome, can result in death as a consequence of a systemic inflammatory response syndrome. The activation and regulation of the immune system play a key role in the initiation, development and prognosis of sepsis. Due to the different periods of sepsis when the objects investigated were incorporated, clinical trials often exhibit negative or even contrary results. Thus, in this review we aim to sort out the current knowledge in how immune cells play a role during sepsis.

Point-of-Care Diagnostic Assays and Novel Preclinical Technologies for Hemostasis and Thrombosis

2021 ◽  
Vol 47 (02) ◽  
pp. 120-128
Author(s):  
Christina Caruso ◽  
Wilbur A. Lam
Keyword(s):  
Point Of Care ◽  
Healing Process ◽  
Coagulation Factors ◽  
Wound Healing Process ◽  
Shear Stresses ◽  
Flow Conditions ◽  
Novel Technologies ◽  
Clinical Consequences ◽  
Complex Wound ◽  
Reproducible Analysis

AbstractHemostasis is a complex wound-healing process involving numerous mechanical and biochemical mechanisms and influenced by many factors including platelets, coagulation factors, and endothelial components. Slight alterations in these mechanisms can lead to either prothrombotic or bleeding consequences, and such hemostatic imbalances can lead to significant clinical consequences with resultant morbidity and mortality. An ideal hemostasis assay would not only address all the unique processes involved in clot formation and resolution but also take place under flow conditions to account for endothelial involvement. Global assays do exist; however, these assays are not flow based. Flow-based assays have been limited secondary to their large blood volume requirements and low throughput, limiting potential clinical applications. Microfluidic-based assays address the aforementioned limitations of both global and flow-based assays by utilizing standardized devices that require low blood volumes, offer reproducible analysis, and have functionality under a range of shear stresses and flow conditions. While still largely confined to the preclinical space, here we aim to discuss these novel technologies and potential clinical implications, particularly in comparison to the current, commercially available point-of-care assays.

scholarly journals The immune response of T cells and therapeutic targets related to regulating the levels of T helper cells after ischaemic stroke

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tian-Yu Lei ◽  
Ying-Ze Ye ◽  
Xi-Qun Zhu ◽  
Daniel Smerin ◽  
Li-Juan Gu ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune System ◽  
Immune Responses ◽  
Ischaemic Stroke ◽  
Immune Cells ◽  
Tissue Injury ◽  
Recovery Period ◽  
Vital Functions ◽  
Anti Inflammatory

AbstractThrough considerable effort in research and clinical studies, the immune system has been identified as a participant in the onset and progression of brain injury after ischaemic stroke. Due to the involvement of all types of immune cells, the roles of the immune system in stroke pathology and associated effects are complicated. Past research concentrated on the functions of monocytes and neutrophils in the pathogenesis of ischaemic stroke and tried to demonstrate the mechanisms of tissue injury and protection involving these immune cells. Within the past several years, an increasing number of studies have elucidated the vital functions of T cells in the innate and adaptive immune responses in both the acute and chronic phases of ischaemic stroke. Recently, the phenotypes of T cells with proinflammatory or anti-inflammatory function have been demonstrated in detail. T cells with distinctive phenotypes can also influence cerebral inflammation through various pathways, such as regulating the immune response, interacting with brain-resident immune cells and modulating neurogenesis and angiogenesis during different phases following stroke. In view of the limited treatment options available following stroke other than tissue plasminogen activator therapy, understanding the function of immune responses, especially T cell responses, in the post-stroke recovery period can provide a new therapeutic direction. Here, we discuss the different functions and temporal evolution of T cells with different phenotypes during the acute and chronic phases of ischaemic stroke. We suggest that modulating the balance between the proinflammatory and anti-inflammatory functions of T cells with distinct phenotypes may become a potential therapeutic approach that reduces the mortality and improves the functional outcomes and prognosis of patients suffering from ischaemic stroke.

scholarly journals Inflammasomes inMycobacterium tuberculosis-Driven Immunity

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Sebastian Wawrocki ◽  
Magdalena Druszczynska
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Inflammatory Response ◽  
Immune Responses ◽  
Proinflammatory Cytokines ◽  
Immune Cells ◽  
Protein Complexes ◽  
Inflammasome Activation ◽  
Host Immune Responses ◽  
Multimeric Protein

The development of effective innate and subsequent adaptive host immune responses is highly dependent on the production of proinflammatory cytokines that increase the activity of immune cells. The key role in this process is played by inflammasomes, multimeric protein complexes serving as a platform for caspase-1, an enzyme responsible for proteolytic cleavage of IL-1βand IL-18 precursors. Inflammasome activation, which triggers the multifaceted activity of these two proinflammatory cytokines, is a prerequisite for developing an efficient inflammatory response against pathogenicMycobacterium tuberculosis(M.tb). This review focuses on the role of NLRP3 and AIM2 inflammasomes inM.tb-driven immunity.

A brief overview on role of graphene based material in therapeutic management of inflammatory response signalling cascades

2020 ◽  
Vol 21 ◽  
pp. 25-36
Author(s):  
Ruchira Das ◽  
◽  
Priyanka Sow ◽  
Sudatta Dey ◽  
Asmita Samadder ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Water Solubility ◽  
Biomedical Application ◽  
Rapid Development ◽  
Graphene Quantum Dots ◽  
Biological Response ◽  
Vital Role ◽  
Therapeutic Management ◽  
In Vivo Models

Graphene is a novel, sp2 carbon atoms bonded, two-dimensional nano-material. Due to their favorable electronic, thermal, optical, and mechanical property, graphene and its derivatives, like graphene oxide (GO) and graphene quantum dots (GQDs) are used in widespread applications. The outstanding potentials of these compounds in the field of nanoelectronics, composite materials, sensors, energy technology etc helped in the rapid development in their functionalization, modulatory effects on various systems of our body. GQDs has been suggested as a new nanomaterial with improved biocompatibility, biodegradability, water solubility and considerably low cytotoxic effects in in vivo models, and are applicable for altering immune responses based on quantum confinement and edge effect properties. The review particularly elucidates the mechanistic approach by which graphene and/ or its derivatives and/ or their nano-compound aid in therapeutic management against myriads of immunological perspectives. GQDs have unique physiochemical properties with carbon sheets showcases out-standing biological response against immunological interventions by altering the activities of t-cell lymphocytes. On the contrary GO plays a vital role in eliciting inflammatory signaling factors by controlling proinflammation and an anti-inflammatory response. Therefore, this review shall help the readers to have an overview of the biomedical application of graphene and its derivatives to design target specific drugs to regulate the immune response based prognosis andcure.

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