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Immunity Oct 2021As resident macrophages of the central nervous system (CNS), microglia are associated with diverse functions essential to the developing and adult brain during... (Review)
Review
As resident macrophages of the central nervous system (CNS), microglia are associated with diverse functions essential to the developing and adult brain during homeostasis and disease. They are aided in their tasks by intricate bidirectional communication with other brain cells under steady-state conditions as well as with infiltrating peripheral immune cells during perturbations. Harmonious cell-cell communication involving microglia are considered crucial to maintain the healthy state of the tissue environment and to overcome pathology such as neuroinflammation. Analyses of such intercellular pathways have contributed to our understanding of the heterogeneous but context-associated microglial responses to environmental cues across neuropathology, including inflammatory conditions such as infections and autoimmunity, as well as immunosuppressive states as seen in brain tumors. Here, we summarize the latest evidence demonstrating how these interactions drive microglia immune and non-immune functions, which coordinate the transition from homeostatic to disease-related cellular states.
Topics: Animals; Central Nervous System; Homeostasis; Humans; Microglia
PubMed: 34644556
DOI: 10.1016/j.immuni.2021.09.014 -
Advances in Physiology Education Dec 2016Total body potassium content and proper distribution of potassium across the cell membrane is of critical importance for normal cellular function. Potassium homeostasis... (Review)
Review
Total body potassium content and proper distribution of potassium across the cell membrane is of critical importance for normal cellular function. Potassium homeostasis is maintained by several different methods. In the kidney, total body potassium content is achieved by alterations in renal excretion of potassium in response to variations in intake. Insulin and beta-adrenergic tone play critical roles in maintaining the internal distribution of potassium under normal conditions. Despite homeostatic pathways designed to maintain potassium levels within the normal range, disorders of altered potassium homeostasis are common. The clinical approach to designing effective treatments relies on understanding the pathophysiology and regulatory influences which govern the internal distribution and external balance of potassium. Here we provide an overview of the key regulatory aspects of normal potassium physiology. This review is designed to provide an overview of potassium homeostasis as well as provide references of seminal papers to guide the reader into a more in depth discussion of the importance of potassium balance. This review is designed to be a resource for educators and well-informed clinicians who are teaching trainees about the importance of potassium balance.
Topics: Animals; Homeostasis; Humans; Kidney; Potassium; Potassium, Dietary
PubMed: 27756725
DOI: 10.1152/advan.00121.2016 -
Biochemical Pharmacology Jan 2021Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple... (Review)
Review
Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple cider vinegar are miracles cures for everything from cancer to COVID-19. Despite these specious claims, the therapeutic value of controlling acid-base balance is indisputable and is the basis of Food and Drug Administration-approved treatments for constipation, epilepsy, metabolic acidosis, and peptic ulcers. In this narrative review, we present evidence in support of the current and potential therapeutic value of countering local and systemic acid-base imbalances, several of which do in fact involve the administration of baking soda (sodium bicarbonate). Furthermore, we discuss the side effects of pharmaceuticals on acid-base balance as well as the influence of acid-base status on the pharmacokinetic properties of drugs. Our review considers all major organ systems as well as information relevant to several clinical specialties such as anesthesiology, infectious disease, oncology, dentistry, and surgery.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Animals; COVID-19; Homeostasis; Humans; Medicine, Traditional; Sodium Bicarbonate
PubMed: 33039418
DOI: 10.1016/j.bcp.2020.114278 -
Experimental Physiology Sep 2008Respiration is primarily regulated for metabolic and homeostatic purposes in the brainstem. However, breathing can also change in response to changes in emotions, such... (Review)
Review
Respiration is primarily regulated for metabolic and homeostatic purposes in the brainstem. However, breathing can also change in response to changes in emotions, such as sadness, happiness, anxiety or fear. Final respiratory output is influenced by a complex interaction between the brainstem and higher centres, including the limbic system and cortical structures. Respiration is important in maintaining physiological homeostasis and co-exists with emotions. In this review, we focus on the relationship between respiration and emotions by discussing previous animal and human studies, including studies of olfactory function in relation to respiration and the piriform-amygdala in relation to respiration. In particular, we discuss oscillations of piriform-amygdala complex activity and respiratory rhythm.
Topics: Animals; Brain Stem; Emotions; Homeostasis; Humans; Respiration; Respiratory Mechanics; Respiratory Physiological Phenomena
PubMed: 18487316
DOI: 10.1113/expphysiol.2008.042424 -
Frontiers in Immunology 2018Macrophages are increasingly recognized as essential players in the maintenance of intestinal homeostasis and as key sentinels of the intestinal immune system. However,... (Review)
Review
Macrophages are increasingly recognized as essential players in the maintenance of intestinal homeostasis and as key sentinels of the intestinal immune system. However, somewhat paradoxically, they are also implicated in chronic pathologies of the gastrointestinal tract, such as inflammatory bowel disease (IBD) and are therefore considered potential targets for novel therapies. In this review, we will discuss recent advances in our understanding of intestinal macrophage heterogeneity, their ontogeny and the potential factors that regulate their origin. We will describe how the local environment of the intestine imprints the phenotypic and functional identity of the macrophage compartment, and how this changes during intestinal inflammation and infection. Finally, we highlight key outstanding questions that should be the focus of future research.
Topics: Animals; Cell Differentiation; Homeostasis; Humans; Inflammatory Bowel Diseases; Intestines; Macrophages
PubMed: 30538701
DOI: 10.3389/fimmu.2018.02733 -
American Journal of Physiology. Renal... Jan 2020The kidney is the central organ involved in maintaining water and sodium balance. In human kidneys, nine aquaporins (AQPs), including AQP1-8 and AQP11, have been found... (Review)
Review
The kidney is the central organ involved in maintaining water and sodium balance. In human kidneys, nine aquaporins (AQPs), including AQP1-8 and AQP11, have been found and are differentially expressed along the renal tubules and collecting ducts with distinct and critical roles in the regulation of body water homeostasis and urine concentration. Dysfunction and dysregulation of these AQPs result in various water balance disorders. This review summarizes current understanding of physiological and pathophysiological roles of AQPs in the kidney, with a focus on recent progress on AQP2 regulation by the nuclear receptor transcriptional factors. This review also provides an overview of AQPs as clinical biomarkers and therapeutic targets for renal diseases.
Topics: Animals; Aquaporins; Homeostasis; Humans; Kidney; Kidney Diseases; Water-Electrolyte Balance
PubMed: 31682170
DOI: 10.1152/ajprenal.00304.2019 -
Nature Reviews. Neuroscience Jul 2011The concept that the gut and the brain are closely connected, and that this interaction plays an important part not only in gastrointestinal function but also in certain... (Review)
Review
The concept that the gut and the brain are closely connected, and that this interaction plays an important part not only in gastrointestinal function but also in certain feeling states and in intuitive decision making, is deeply rooted in our language. Recent neurobiological insights into this gut-brain crosstalk have revealed a complex, bidirectional communication system that not only ensures the proper maintenance of gastrointestinal homeostasis and digestion but is likely to have multiple effects on affect, motivation and higher cognitive functions, including intuitive decision making. Moreover, disturbances of this system have been implicated in a wide range of disorders, including functional and inflammatory gastrointestinal disorders, obesity and eating disorders.
Topics: Brain; Enteric Nervous System; Gastrointestinal Tract; Homeostasis; Humans
PubMed: 21750565
DOI: 10.1038/nrn3071 -
Nature Reviews. Molecular Cell Biology Nov 2018Mammalian cells respond to stress by activating mechanisms that support cellular functions and hence maintain microenvironmental and organismal homeostasis.... (Review)
Review
Mammalian cells respond to stress by activating mechanisms that support cellular functions and hence maintain microenvironmental and organismal homeostasis. Intracellular responses to stress, their regulation and their pathophysiological implications have been extensively studied. However, little is known about the signals that emanate from stressed cells to enable a coordinated adaptive response across tissues, organs and the whole organism. Considerable evidence has now accumulated indicating that the intracellular mechanisms that are activated in response to different stresses - which include the DNA damage response, the unfolded protein response, mitochondrial stress signalling and autophagy - as well as the mechanisms ensuring the proliferative inactivation or elimination of terminally damaged cells - such as cell senescence and regulated cell death - are all coupled with the generation of signals that elicit microenvironmental and/or systemic responses. These signals, which involve changes in the surface of stressed cells and/or the secretion of soluble factors or microvesicles, generally support systemic homeostasis but can also contribute to maladaptation and disease.
Topics: Animals; Cellular Microenvironment; Cellular Senescence; Homeostasis; Humans; Signal Transduction; Stress, Physiological
PubMed: 30305710
DOI: 10.1038/s41580-018-0068-0 -
American Journal of Physiology.... Apr 2019Homeostasis is a founding principle of integrative physiology. In current systems biology, however, homeostasis seems almost invisible. Is homeostasis a key goal driving... (Review)
Review
Homeostasis is a founding principle of integrative physiology. In current systems biology, however, homeostasis seems almost invisible. Is homeostasis a key goal driving body processes, or is it an emergent mechanistic fact? In this perspective piece, I propose that the integrative physiological and systems biological viewpoints about homeostasis reflect different epistemologies, different philosophies of knowledge. Integrative physiology is concept driven. It attempts to explain biological phenomena by continuous formation of theories that experimentation or observation can test. In integrative physiology, "function" refers to goals or purposes. Systems biology is data driven. It explains biological phenomena in terms of "omics"-i.e., genomics, gene expression, epigenomics, proteomics, and metabolomics-it depicts the data in computer models of complex cascades or networks, and it makes predictions from the models. In systems biology, "function" refers more to mechanisms than to goals. The integrative physiologist emphasizes homeostasis of internal variables such as Pco and blood pressure. The systems biologist views these emphases as teleological and unparsimonious in that the "regulated variable" (e.g., arterial Pco and blood pressure) and the "regulator" (e.g., the "carbistat" and "barostat") are unobservable constructs. The integrative physiologist views systems biological explanations as not really explanations but descriptions that cannot account for phenomena we humans believe exist, although they cannot be observed directly, such as feelings and, ultimately, the conscious mind. This essay reviews the history of the two epistemologies, emphasizing autonomic neuroscience. I predict rapprochement of integrative physiology with systems biology. The resolution will avoid teleological purposiveness, transcend pure mechanism, and incorporate adaptiveness in evolution, i.e., "Darwinian medicine."
Topics: Animals; Biological Evolution; History, 19th Century; History, 20th Century; Homeostasis; Humans; Physiological Phenomena; Physiology; Systems Biology
PubMed: 30649893
DOI: 10.1152/ajpregu.00396.2018 -
Biomolecules Feb 2022Strictly controlled degradation of the proteome is a key factor in maintaining cellular homeostasis and allows a rapid and effective response to a variety of different...
Strictly controlled degradation of the proteome is a key factor in maintaining cellular homeostasis and allows a rapid and effective response to a variety of different stress challenges [...].
Topics: Homeostasis; Proteasome Endopeptidase Complex; Proteome
PubMed: 35327535
DOI: 10.3390/biom12030343