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European Journal of Endocrinology Nov 2013A wide variety of autocrine/paracrine bioactive signals are able to modulate corticosteroid secretion in the human adrenal gland. These regulatory factors, released in... (Meta-Analysis)
Meta-Analysis Review
A wide variety of autocrine/paracrine bioactive signals are able to modulate corticosteroid secretion in the human adrenal gland. These regulatory factors, released in the vicinity of adrenocortical cells by diverse cell types comprising chromaffin cells, nerve terminals, cells of the immune system, endothelial cells, and adipocytes, include neuropeptides, biogenic amines, and cytokines. A growing body of evidence now suggests that paracrine mechanisms may also play an important role in the physiopathology of adrenocortical hyperplasias and tumors responsible for primary adrenal steroid excess. These intra-adrenal regulatory systems, although globally involving the same actors as those observed in the normal gland, display alterations at different levels, which reinforce the capacity of paracrine factors to stimulate the activity of adrenocortical cells. The main modifications in the adrenal local control systems reported by now include hyperplasia of cells producing the paracrine factors and abnormal expression of the latter and their receptors. Because steroid-secreting adrenal neoplasms are independent of the classical endocrine regulatory factors angiotensin II and ACTH, which are respectively suppressed by hyperaldosteronism and hypercortisolism, these lesions have long been considered as autonomous tissues. However, the presence of stimulatory substances within the neoplastic tissues suggests that steroid hypersecretion is driven by autocrine/paracrine loops that should be regarded as promising targets for pharmacological treatments of primary adrenal disorders. This new potential therapeutic approach may constitute an alternative to surgical removal of the lesions that is classically recommended in order to cure steroid excess.
Topics: Adrenal Cortex Hormones; Adrenal Cortex Neoplasms; Adrenal Glands; Adrenocortical Hyperfunction; Autocrine Communication; Humans; Paracrine Communication; Renin-Angiotensin System
PubMed: 23956298
DOI: 10.1530/EJE-13-0308 -
Frontiers in Cell and Developmental... 2022Cell segregation mechanisms play essential roles during the development of the central nervous system (CNS) to support its organization into distinct compartments. The...
Cell segregation mechanisms play essential roles during the development of the central nervous system (CNS) to support its organization into distinct compartments. The Slit protein is a secreted signal, classically considered a paracrine repellent for axonal growth through Robo receptors. However, its function in the compartmentalization of CNS is less explored. In this work, we show that Slit and Robo3 are expressed in the same neuronal population of the optic lobe, where they are required for the correct compartmentalization of optic lobe neuropils by the action of an autocrine/paracrine mechanism. We characterize the endocytic route followed by the Slit/Robo3 complex and detected genetic interactions with genes involved in endocytosis and actin dynamics. Thus, we report that the Slit-Robo3 pathway regulates the morphogenesis of the optic lobe through an atypical autocrine/paracrine mechanism in addition to its role in axon guidance, and in association with proteins of the endocytic pathway and small GTPases.
PubMed: 35982851
DOI: 10.3389/fcell.2022.874362 -
Molecular Reproduction and Development Nov 2015Adenosine triphosphate (ATP) is released from the cell by multiple mechanisms. The extracellular form of this purine is processed by ectonucleotidases, resulting in a... (Review)
Review
Adenosine triphosphate (ATP) is released from the cell by multiple mechanisms. The extracellular form of this purine is processed by ectonucleotidases, resulting in a variety of dephosphorylated metabolites that can bind to specific receptors found in the membrane of target cells; such purinergic signaling is important as an autocrine-paracrine intercellular communication system that influences tissue physiology. In this review, we summarize the studies analyzing purinergic activity in the ovary, which can modulate cellular physiology-including sensitivity to gonadotropins-in several ovarian cell types, including the cumulus-cell complex, granulosa cells, theca cells, and the ovarian surface epithelium. These functions support a role for ATP as an important intra-ovarian messenger, and open new lines of research that can improve our understanding of mechanisms regulating ovarian function and the fine-tuning of folliculogenesis.
Topics: Adenosine Triphosphate; Animals; Female; Humans; Ovary; Second Messenger Systems
PubMed: 26275037
DOI: 10.1002/mrd.22537 -
Annals of the New York Academy of... May 1998The thymus involutes relatively early in life; cellular immune deficiencies of aging correspond to decline in function of the hypothalamic-pituitary-endocrine axis.... (Review)
Review
The thymus involutes relatively early in life; cellular immune deficiencies of aging correspond to decline in function of the hypothalamic-pituitary-endocrine axis. Recent studies point to important roles for the pituitary, the pineal, and the autonomic nervous system as well as the thyroid, gonads and adrenals in the thymus integrity and function. Thymic function at the local level requires complex cellular interactions among thymic stromal cells and developing thymocytes involving paracrine and autocrine mediators including interleukins (ILs) 1, 2, 6, 7, 8, colony-stimulating factors (CSFs), interferon-gamma, thymosin alpha 1, and zinc-thymulin. An important endocrine function of the thymus is to package zinc in zinc-thymulin for delivery to the periphery. Thymic involution has been treated with interleukins, thymic hormones, growth hormone, prolactin, melatonin, zinc, and others. Our work to reverse thymic involution in hydrocortisone-treated, aged mice with interleukins, thymosin alpha 1, and zinc will be reviewed. Recent efforts to treat successfully immune deficiency in aged and cancer-bearing humans will be presented.
Topics: Animals; Epithelial Cells; Hormones; Humans; Neurosecretory Systems; Thymus Gland
PubMed: 9629262
DOI: 10.1111/j.1749-6632.1998.tb09574.x -
Neurological Sciences : Official... Jan 2023Immune-mediated inflammatory diseases (IMIDs) are a group of common heterogeneous disorders, characterized by an alteration of cellular homeostasis. Primarily, it has... (Review)
Review
Immune-mediated inflammatory diseases (IMIDs) are a group of common heterogeneous disorders, characterized by an alteration of cellular homeostasis. Primarily, it has been shown that the release and diffusion of neurotransmitters from nervous tissue could result in signaling through lymphocyte cell-surface receptors and the modulation of immune function. This finding led to the idea that the neurotransmitters could serve as immunomodulators. It is now manifested that neurotransmitters can also be released from leukocytes and act as autocrine or paracrine modulators. Increasing data indicate that there is a crosstalk between inflammation and alterations in neurotransmission. The primary goal of this review is to demonstrate how these two pathways may converge at the level of the neuron and glia to involve in IMID. We review the role of neurotransmitters in IMID. The different effects that these compounds exert on a variety of immune cells are also reviewed. Current and future developments in understanding the cross-talk between the immune and nervous systems will undoubtedly identify new ways for treating immune-mediated diseases utilizing agonists or antagonists of neurotransmitter receptors.
Topics: Humans; Immune System; Signal Transduction; Neurons; Inflammation; Neurotransmitter Agents
PubMed: 36169755
DOI: 10.1007/s10072-022-06413-0 -
International Journal of Cardiology Oct 2014The natriuretic peptide (NP) system is an important endocrine, autocrine and paracrine system, consisting of a family of peptides which provide cardiac, renal and... (Review)
Review
The natriuretic peptide (NP) system is an important endocrine, autocrine and paracrine system, consisting of a family of peptides which provide cardiac, renal and vascular effects that, through their beneficial physiological actions, play a key role in maintaining overall cardiovascular health. Traditionally, the pathophysiological origins of cardio-renal disease have been viewed as the domain of the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system (SNS), with inappropriate activation of both systems leading to deleterious changes in cardio-renal function and structure. Therapies designed to suppress the RAAS and the SNS have been routinely employed to address the consequences of cardio-renal disease. However, it is now becoming increasingly apparent that enhancing the beneficial physiological effects of the NP system may represent an attractive alternative therapeutic approach to counter the pathophysiological effects of disease. In particular, innovative therapeutic strategies aimed at enhancing the physiological benefits afforded by NPs while simultaneously suppressing the RAAS are generating increasing interest as potential treatment options for the management of cardio-renal disease.
Topics: Cardiovascular Diseases; Energy Metabolism; Humans; Kidney Diseases; Natriuretic Peptides; Neprilysin; Vascular Remodeling
PubMed: 25213572
DOI: 10.1016/j.ijcard.2014.08.032 -
American Journal of Physiology.... Mar 2012The bile duct system of the liver is lined by epithelial cells (i.e., cholangiocytes) that respond to a large number of neuroendocrine factors through alterations in... (Review)
Review
The bile duct system of the liver is lined by epithelial cells (i.e., cholangiocytes) that respond to a large number of neuroendocrine factors through alterations in their proliferative activities and the subsequent modification of the microenvironment. As such, activation of biliary proliferation compensates for the loss of cholangiocytes due to apoptosis and slows the progression of toxic injury and cholestasis. Over the course of the last three decades, much progress has been made in identifying the factors that trigger the biliary epithelium to remodel and grow. Because a large number of autocrine factors have recently been identified as relevant clinical targets, a compiled review of their contributions and function in cholestatic liver diseases would be beneficial. In this context, it is important to define the specific processes triggered by autocrine factors that promote cholangiocytes to proliferate, activate neighboring cells, and ultimately lead to extracellular matrix deposition. In this review, we discuss the role of each of the known autocrine factors with particular emphasis on proliferation and fibrogenesis. Because many of these molecules interact with one another throughout the progression of liver fibrosis, a model speculating their involvement in the progression of cholestatic liver disease is also presented.
Topics: Animals; Autocrine Communication; Bile Ducts; Biliary Tract; Cell Proliferation; Endothelins; Epithelial Cells; Estrogens; Humans; Integrins; Liver Cirrhosis; Neuropeptides; Peptide Hormones; Platelet-Derived Growth Factor; Renin-Angiotensin System; Transforming Growth Factor beta
PubMed: 22194419
DOI: 10.1152/ajpgi.00482.2011 -
Nature Reviews. Immunology Jul 2005Sphingosine 1-phosphate (S1P) is a biologically active lysophospholipid that transmits signals through a family of G-protein-coupled receptors to control cellular... (Review)
Review
Sphingosine 1-phosphate (S1P) is a biologically active lysophospholipid that transmits signals through a family of G-protein-coupled receptors to control cellular differentiation and survival, as well as the vital functions of several types of immune cell. In this Review article, we discuss recent results that indicate that S1P and its receptors are required for the emigration of thymocytes from the thymus, the trafficking of lymphocytes in secondary lymphoid organs and the migration of B cells into splenic follicles. In an autocrine manner, through interactions with different G-protein-coupled receptors, S1P also enhances optimal mast-cell migration and release of pro-inflammatory mediators in allergic reactions. S1P-S1P-receptor regulatory systems might therefore be novel targets for the therapy of diverse immunological diseases.
Topics: Animals; Autocrine Communication; Endothelial Cells; Lysophospholipids; Models, Animal; Paracrine Communication; Receptors, Lysosphingolipid; Sphingosine; T-Lymphocytes
PubMed: 15999095
DOI: 10.1038/nri1650 -
Critical Reviews in Oral Biology and... 1991This article reviews the evolution of concepts regarding the biological foundation of force-induced tooth movement. Nineteenth century hypotheses proposed two... (Review)
Review
This article reviews the evolution of concepts regarding the biological foundation of force-induced tooth movement. Nineteenth century hypotheses proposed two mechanisms: application of pressure and tension to the periodontal ligament (PDL), and bending of the alveolar bone. Histologic investigations in the early and middle years of the 20th century revealed that both phenomena actually occur concomitantly, and that cells, as well as extracellular components of the PDL and alveolar bone, participate in the response to applied mechanical forces, which ultimately results in remodeling activities. Experiments with isolated cells in culture demonstrated that shape distortion might lead to cellular activation, either by opening plasma membrane ion channels, or by crystallizing cytoskeletal filaments. Mechanical distortion of collagenous matrices, mineralized or non-mineralized, may, on the other hand, evoke the development of bioelectric phenomena (stress-generated potentials and streaming potentials) that are capable of stimulating cells by altering the electric charge on their membrane or their fluid envelope. In intact animals, mechanical perturbations on the order of about 1 min/d are apparently sufficient to cause profound osteogenic responses, perhaps due to matrix proteoglycan-related "strain memory". Enzymatically isolated human PDL cells respond biochemically to mechanical and chemical signals. The latter include endocrines, autocrines, and paracrines. Histochemical and immunohistochemical studies showed that during the early places of tooth movement, PDL fluids are shifted, and cells and matrix are distorted. Vasoactive neurotransmitters are released from periodontal nerve terminals, causing leukocytes to migrate out of adjacent capillaries. Cytokines and growth factors are secreted by these cells, stimulating PDL cells and alveolar bone lining cells to remodel their related matrices. This remodeling activity facilitates movement of teeth into areas in which bone had been resorbed. This emerging information suggests that in the living mammal, many cell types are involved in the biological response to applied mechanical stress to teeth, and thereby to bone. Essentially, cells of the nervous, immune, and endocrine systems become involved in the activation and response of PDL and alveolar bone cells to applied stresses. This fact implies that research in the area of the biological response to force application to teeth should be sufficiently broad to include explorations of possible associations between physical, cellular, and molecular phenomena. The goals of this investigative field should continue to expound on fundamental principles, particularly on extrapolating new findings to the clinical environment, where millions of patients are subjected annually to applications of mechanical forces to their teeth for long periods of time in an effort to improve their position in the oral cavity.(ABSTRACT TRUNCATED AT 400 WORDS)
Topics: Humans; Periodontium; Tooth; Tooth Movement Techniques
PubMed: 1742417
DOI: 10.1177/10454411910020040101 -
The European Journal of Neuroscience Sep 2008Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated... (Review)
Review
Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABA(A)Rs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABA(A)Rs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABA(A)R modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABA(A)Rs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABA(A)Rs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABA(A)Rs persist into adulthood. Altogether, axonal GABA(A)Rs appear as potent neuronal modulators of the mammalian CNS.
Topics: Action Potentials; Animals; Autocrine Communication; Axons; Calcium Signaling; Central Nervous System; Humans; Receptors, GABA-A; Synaptic Potentials; Synaptic Transmission; gamma-Aminobutyric Acid
PubMed: 18691324
DOI: 10.1111/j.1460-9568.2008.06404.x