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Clinics in Dermatology 2016
Topics: Dermatology; Facial Dermatoses; Humans; Mouth Diseases; Mouth Mucosa
PubMed: 27343957
DOI: 10.1016/j.clindermatol.2016.02.015 -
Journal of Pediatric Gastroenterology... Jun 2018The mucosal maltase enzymes are characterized by an activity that produces glucose from linear glucose polymers, assayed with the disaccharide maltose. The related... (Review)
Review
The mucosal maltase enzymes are characterized by an activity that produces glucose from linear glucose polymers, assayed with the disaccharide maltose. The related enzyme isomaltase produces glucose from branched glucose polymers, assayed with palatinose. Maltase and isomaltase activities are part of the 4 disaccharidases assayed from clinical duodenal biopsy homogenates. The reported maltase activities are more difficult to interpret than lactase or sucrase activities because both the sucrase-isomaltase and maltase-glucoamylase proteins have overlapping maltase activities. The early work of Dahlqvist identified 4 maltase activities from human small intestinal mucosa. On one peptide, sucrase (maltase Ib) and isomaltase (maltase Ia) activities shared maltase activities but identified the enzymes as sucrase-isomaltase. On the other peptide, no distinguishing characteristics of the 2 maltase activities (maltases II and III) were detected and the activities identified as maltase-glucoamylase. The nutritional/clinical importance of small intestinal maltase and isomaltase activities are due to their crucial role in the digestion of food starches to absorbable free glucose. This review focuses on the interpretation of biopsy maltase activities in the context of reported lactase, sucrase, maltase, and palatinase biopsy assay activity patterns. We present a classification of mucosal maltase deficiencies and novel primary maltase deficiency (Ib, II, III) and provide a clarification of the role of maltase activity assayed from clinically obtained duodenal biopsies, as a path toward future clinical and molecular genomic investigations.
Topics: Animals; Digestion; Humans; Intestinal Mucosa; Mutation; alpha-Glucosidases
PubMed: 29762372
DOI: 10.1097/MPG.0000000000001955 -
Biomolecules May 2021Post-surgical adhesions are internal scar tissue and a major health and economic burden. Adhesions affect and involve the peritoneal lining of the abdominal cavity,... (Review)
Review
Post-surgical adhesions are internal scar tissue and a major health and economic burden. Adhesions affect and involve the peritoneal lining of the abdominal cavity, which consists of a continuous mesothelial covering of the cavity wall and majority of internal organs. Our understanding of the full pathophysiology of adhesion formation is limited by the fact that the mechanisms regulating normal serosal repair and regeneration of the mesothelial layer are still being elucidated. Emerging evidence suggests that mesothelial cells do not simply form a passive barrier but perform a wide range of important regulatory functions including maintaining a healthy peritoneal homeostasis as well as orchestrating events leading to normal repair or pathological outcomes following injury. Here, we summarise recent advances in our understanding of serosal repair and adhesion formation with an emphasis on molecular mechanisms and novel gene expression signatures associated with these processes. We discuss changes in mesothelial biomolecular marker expression during peritoneal development, which may help, in part, to explain findings in adults from lineage tracing studies using experimental adhesion models. Lastly, we highlight examples of where local tissue specialisation may determine a particular response of peritoneal cells to injury.
Topics: Gene Expression Regulation, Developmental; Gene Regulatory Networks; Genetic Markers; Humans; Peritoneum; Tissue Adhesions
PubMed: 34063089
DOI: 10.3390/biom11050692 -
Comprehensive Physiology Sep 2017Epithelial cells are essential to the survival and homeostasis of complex organisms. These cells cover the surfaces of all mucosae, the skin, and other compartmentalized... (Review)
Review
Epithelial cells are essential to the survival and homeostasis of complex organisms. These cells cover the surfaces of all mucosae, the skin, and other compartmentalized structures essential to physiological function. In addition to maintenance of barriers that separate internal and external compartments, epithelia display a variety of organ-specific differentiated functions. Function is reflected in overall epithelial structure and organization, shape of individual cells, and proteins expressed by these cells. More than one epithelial cell type is often present within a single organ and, in many cases, individual cells differentiate to change their functional behaviors as part of normal development or in response to extracellular stimuli. This article discusses the diversity of epithelial structure and function in general terms and explores representative tissues in greater depth to highlight organ specific functions and their contributions to physiology and disease. © 2017 American Physiological Society. Compr Physiol 7:1497-1518, 2017.
Topics: Animals; Epithelial Cells; Humans; Intestinal Absorption; Intestinal Mucosa; Nephrons; Organ Specificity; Respiratory Mucosa; Urothelium
PubMed: 28915334
DOI: 10.1002/cphy.c170003 -
Biochimica Et Biophysica Acta Aug 2016The lipid bilayer component of biological membranes is important for the distribution, organization, and function of bilayer spanning proteins. These physical barriers... (Review)
Review
The lipid bilayer component of biological membranes is important for the distribution, organization, and function of bilayer spanning proteins. These physical barriers are subjected to bilayer perturbations. As a consequence, nature has evolved proteins that are able to sense changes in the bilayer properties and transform these lipid-mediated stimuli into intracellular signals. A structural feature that most signal-transducing membrane-embedded proteins have in common is one or more α-helices that traverse the lipid bilayer. Because of the interaction with the surrounding lipids, the organization of these transmembrane helices will be sensitive to membrane properties, like hydrophobic thickness. The helices may adapt to the lipids in different ways, which in turn can influence the structure and function of the intact membrane proteins. We review recent insights into the molecular basis of thermosensing via changes in membrane thickness and consider examples in which the hydrophobic matching can be demonstrated using reconstituted membrane systems. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
Topics: Animals; Cold-Shock Response; Humans; Lipid Bilayers; Mechanotransduction, Cellular; Membrane Lipids; Membranes; Signal Transduction; Thermosensing
PubMed: 26776056
DOI: 10.1016/j.bbalip.2016.01.003 -
Mucosal Immunology Sep 2021The airway epithelium protects us from environmental insults, which we encounter with every breath. Not only does it passively filter large particles, it also senses... (Review)
Review
The airway epithelium protects us from environmental insults, which we encounter with every breath. Not only does it passively filter large particles, it also senses potential danger and alerts other cells, including immune and nervous cells. Together, these tissues orchestrate the most appropriate response, balancing the need to eliminate the danger with the risk of damage to the host. Each cell subset within the airway epithelium plays its part, and when impaired, may contribute to the development of respiratory disease. Here we highlight recent advances regarding the cellular and functional heterogeneity along the airway epithelium and discuss how we can use this knowledge to design more effective, targeted therapeutics.
Topics: Animals; Biological Variation, Population; Biomarkers; Disease Susceptibility; Drug Development; Epithelial Cells; Gene Expression Regulation; Homeostasis; Host-Pathogen Interactions; Humans; Immunity, Mucosal; Molecular Targeted Therapy; Respiratory Mucosa; Signal Transduction
PubMed: 33608655
DOI: 10.1038/s41385-020-00370-7 -
British Dental Journal Nov 2017While the majority of disorders of the mouth are centred upon the direct action of plaque, the oral tissues can be subject to change or damage as a consequence of... (Review)
Review
While the majority of disorders of the mouth are centred upon the direct action of plaque, the oral tissues can be subject to change or damage as a consequence of disease that predominantly affects other body systems. Such oral manifestations of systemic disease can be highly variable in both frequency and presentation. As lifespan increases and medical care becomes ever more complex and effective it is likely that the numbers of individuals with oral manifestations of systemic disease will continue to rise. The present article provides a succinct review of oral manifestations of systemic disease. In view of this article being part of a wider BDJ themed issue on the subject of oral medicine, this review focuses upon oral mucosal and salivary gland disorders that may arise as a consequence of systemic disease.
Topics: Humans; Mouth Diseases; Mouth Mucosa
PubMed: 29123296
DOI: 10.1038/sj.bdj.2017.884 -
Methods in Molecular Biology (Clifton,... 2016Neoangiogenesis constitutes one of the first steps of tumor progression beyond a critical size of tumor growth, which supplies a dormant mass of cancerous cells with the...
Neoangiogenesis constitutes one of the first steps of tumor progression beyond a critical size of tumor growth, which supplies a dormant mass of cancerous cells with the required nutrient supply and gaseous exchange through blood vessels essentially needed for their sustained and aggressive growth. In order to understand any biological process, it becomes imperative that we use models, which could mimic the actual biological system as closely as possible. Hence, finding the most appropriate model is always a vital part of any experimental design. Angiogenesis research has also been much affected due to lack of simple, reliable, and relevant models which could be easily quantitated. The angiogenesis models have been used extensively for studying the action of various molecules for agonist or antagonistic behaviour and associated mechanisms. Here, we have described two protocols or models which have been popularly utilized for studying angiogenic parameters. Rat aortic ring assay tends to bridge the gap between in vitro and in vivo models. The chorioallantoic membrane (CAM) assay is one of the most utilized in vivo model system for angiogenesis-related studies. The CAM is highly vascularized tissue of the avian embryo and serves as a good model to study the effects of various test compounds on neoangiogenesis.
Topics: Animals; Aorta; Biological Assay; Chickens; Chorioallantoic Membrane; Culture Techniques; Mice; Neovascularization, Pathologic; Rats
PubMed: 26608294
DOI: 10.1007/978-1-4939-3191-0_10 -
Philosophical Transactions of the Royal... Dec 2022Embryonic development and growth in placental mammals proceeds with the support of exchanges of gases, nutrients and waste products between maternal tissues and... (Review)
Review
Embryonic development and growth in placental mammals proceeds with the support of exchanges of gases, nutrients and waste products between maternal tissues and offspring. Murine embryos are surrounded by several extraembryonic membranes, parietal and visceral yolk sacs, and amnion in the uterus. Notably, the parietal yolk sac is the most outer membrane, consists of three layers, trophoblasts and parietal endoderm (PaE) cells, and is separated by a thick basal lamina termed Reichert's membrane (RM). RM is composed of extracellular matrix (ECM) initially formed as the basement membrane of the trophectoderm of pre-implanted embryos and followed by the heavy deposition of ECM mainly produced in PaE cells of post-implanted embryos. In addition to the physiological roles of RM, such as gas and nutrient exchange, it also plays a crucial role in cushioning and dispersing intrauterine pressures exerted on embryos for normal egg-cylinder morphogenesis. Mechanistically, such intrauterine pressures generated by uterine smooth muscle contractions appear to be involved in the elongation of the egg-cylinder shape, along with primary axis formation, as an important biomechanical element . This review focuses on our current views of the roles of RM in properly buffering intrauterine mechanical forces for mouse egg-cylinder morphogenesis. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.
Topics: Animals; Basement Membrane; Endoderm; Female; Gases; Mammals; Mice; Placenta; Pregnancy; Waste Products; Yolk Sac
PubMed: 36252218
DOI: 10.1098/rstb.2021.0257 -
Philosophical Transactions of the Royal... Dec 2022In amniotic vertebrates (birds, reptiles and mammals), an extraembryonic structure called the chorioallantoic membrane (CAM) functions as respiratory organ for embryonic...
In amniotic vertebrates (birds, reptiles and mammals), an extraembryonic structure called the chorioallantoic membrane (CAM) functions as respiratory organ for embryonic development. The CAM is derived from fusion between two pre-existing membranes, the allantois, a hindgut diverticulum and a reservoir for metabolic waste, and the chorion which marks the embryo's external boundary. Modified CAM in eutherian mammals, including humans, gives rise to chorioallantoic placenta. Despite its importance, little is known about cellular and molecular mechanisms mediating CAM formation and maturation. In this work, using the avian model, we focused on the early phase of CAM morphogenesis when the allantois and chorion meet and initiate fusion. We report here that chicken chorioallantoic fusion takes place when the allantois reaches the size of 2.5-3.0 mm in diameter and in about 6 hours between E3.75 and E4. Electron microscopy and immunofluorescence analyses suggested that before fusion, in both the allantois and chorion, an epithelial-shaped mesothelial layer is present, which dissolves after fusion, presumably by undergoing epithelial-mesenchymal transition. The fusion process , however, is independent of allantoic growth, circulation, or its connection to the developing mesonephros. Mesoderm cells derived from the allantois and chorion can intermingle post-fusion, and chorionic ectoderm cells exhibit a specialized sub-apical intercellular interface, possibly to facilitate infiltration of allantois-derived vascular progenitors into the chorionic ectoderm territory for optimal oxygen transport. Finally, we investigated chorioallantoic fusion-like process in primates, with limited numbers of archived human and fresh macaque samples. We summarize the similarities and differences of CAM formation among different amniote groups and propose that mesothelial epithelial-mesenchymal transition mediates chorioallantoic fusion in most amniotic vertebrates. Further study is needed to clarify tissue morphogenesis leading to chorioallantoic fusion in primates. Elucidating molecular mechanisms regulating mesothelial integrity and epithelial-mesenchymal transition will also help understand mesothelial diseases in the adult, including mesothelioma, ovarian cancer and fibrosis. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.
Topics: Allantois; Animals; Chorioallantoic Membrane; Chorion; Epithelium; Humans; Mammals; Oxygen
PubMed: 36252211
DOI: 10.1098/rstb.2021.0263