Search results for "Tissue homeostasis"

Single cell RNAseq provides a molecular and cellular cartography of changes to the human endometrium through the menstrual cycle

2018

SummaryIn a human menstrual cycle, the endometrium undergoes remodeling, shedding, and regeneration, all of which are driven by substantial gene expression changes in the underlying cellular hierarchy. Despite its importance in human fertility and regenerative biology, mechanistic understanding of this unique type of tissue homeostasis remains rudimentary. We characterized the transcriptomic transformation of human endometrium at single cell resolution, dissecting the multidimensional cellular heterogeneity of this tissue across the entire natural menstrual cycle. We profiled the behavior of 6 endometrial cell types, including a previously uncharacterized ciliated epithelial cell type, duri…

Vitamin A Deficiency and Alterations in the Extracellular Matrix

2014

Vitamin A or retinol which is the natural precursor of several biologically active metabolites can be considered the most multifunctional vitamin in mammals. Its deficiency is currently, along with protein malnutrition, the most serious and common nutritional disorder worldwide. It is necessary for normal embryonic development and postnatal tissue homeostasis, and exerts important effects on cell proliferation, differentiation and apoptosis. These actions are produced mainly by regulating the expression of a variety of proteins through transcriptional and non-transcriptional mechanisms. Extracellular matrix proteins are among those whose synthesis is known to be modulated by vitamin A. Reti…

Structure and Function of Desmosomes

2007

Desmosomes are prominent adhesion sites that are tightly associated with the cytoplasmic intermediate filament cytoskeleton providing mechanical stability in epithelia and also in several nonepithelial tissues such as cardiac muscle and meninges. They are unique in terms of ultrastructural appearance and molecular composition with cell type-specific variations. The dynamic assembly properties of desmosomes are important prerequisites for the acquisition and maintenance of tissue homeostasis. Disturbance of this equilibrium therefore not only compromises mechanical resilience but also affects many other tissue functions as becomes evident in various experimental scenarios and multiple diseas…

Levels of thrombopoietin in aqueous humor of patients with noninfectious acute anterior uveitis

2015

José-Juan Mondejar,1,4 David Salom,1,3 Salvador Garcia-Delpech,1,2 Manuel Diaz-Llopis11Ophthalmology Department, School of Medicine, University of Valencia, 2Ophthalmology Department, Hospital Universitario La Fe, 3Ophthalmology Department, Hospital de Manises, Valencia, 4Ophthalmology Department, Hospital General Universitario de Alicante, Alicante, SpainPurpose: To measure thrombopoietin (TPO) levels in the serum and aqueous humors of patients with noninfectious acute anterior uveitis.Methods: A prospective, comparative, controlled study. Serum and aqueous humors were obtained from the eyes of 16 patients with noninfectious acute anterior uveitis. TPO levels were measu…

2015

Cells secrete extracellular vesicles (EVs) by default and in response to diverse stimuli for the purpose of cell communication and tissue homeostasis. EVs are present in all body fluids including peripheral blood, and their appearance correlates with specific physiological and pathological conditions. Here, we show that physical activity is associated with the release of nano-sized EVs into the circulation. Healthy individuals were subjected to an incremental exercise protocol of cycling or running until exhaustion, and EVs were isolated from blood plasma samples taken before, immediately after and 90 min after exercise. Small EVs with the size of 100–130 nm, that carried proteins character…

Precapillary Servo Control of Blood Pressure and Postcapillary Adjustment of Flow to Tissue Metabolic Status

1996

Background There are several shortcomings in current understanding of how the microvasculature maintains tissue homeostasis. Presently unresolved issues include (1) integration of the potentially conflicting needs for capillary perfusion and hydrostatic pressure regulation, (2) an understanding of signal transmission pathways for conveying information about tissue energetic status from undersupplied tissue sites to the arterioles, (3) accounting for the experimentally observed interrelations between precapillary and postcapillary resistances, and (4) an explanation of how precise local adjustment of perfusion to metabolic demands is achieved. Methods and Results A novel conceptualization o…

Transcription factors controlling development and function of innate lymphoid cells.

2014

Abstract Innate lymphoid cells (ILCs) are a heterogeneous group of lymphocytes, which play an important role in tissue homeostasis at epithelial surfaces. They are scarce in spleen and lymph nodes, but substantial numbers can be found in the intestinal mucosa even at steady state. There, they represent the first line of defence against invading pathogens and contribute to lymphorganogenesis, tissue repair and, when inappropriately activated, immune pathology. Lineage-specific development, function and maintenance of these cells depend on a restricted set of transcription factors that partially emerged as a result of diversification and selection during vertebrate evolution. The differential…

On the Choice of the Extracellular Vesicles for Therapeutic Purposes

2019

Extracellular vesicles (EVs) are lipid membrane vesicles released by all human cells and are widely recognized to be involved in many cellular processes, both in physiological and pathological conditions. They are mediators of cell-cell communication, at both paracrine and systemic levels, and therefore they are active players in cell differentiation, tissue homeostasis, and organ remodeling. Due to their ability to serve as a cargo for proteins, lipids, and nucleic acids, which often reflects the cellular source, they should be considered the future of the natural nanodelivery of bio-compounds. To date, natural nanovesicles, such as exosomes, have been shown to represent a source of diseas…

The prolyl-isomerase PIN1 is essential for nuclear Lamin-B structure and function and protects heterochromatin under mechanical stress.

2021

Summary: Chromatin organization plays a crucial role in tissue homeostasis. Heterochromatin relaxation and consequent unscheduled mobilization of transposable elements (TEs) are emerging as key contributors of aging and aging-related pathologies, including Alzheimer’s disease (AD) and cancer. However, the mechanisms governing heterochromatin maintenance or its relaxation in pathological conditions remain poorly understood. Here we show that PIN1, the only phosphorylation-specific cis/trans prolyl isomerase, whose loss is associated with premature aging and AD, is essential to preserve heterochromatin. We demonstrate that this PIN1 function is conserved from Drosophila to humans and prevents…

Mast cells as protectors of health.

2019

Mast cells (MCs), which are well known for their effector functions in T(H)2-skewed allergic and also autoimmune inflammation, have become increasingly acknowledged for their role in protection of health. It is now clear that they are also key modulators of immune responses at interface organs, such as the skin or gut. MCs can prime tissues for adequate inflammatory responses and cooperate with dendritic cells in T-cell activation. They also regulate harmful immune responses in trauma and help to successfully orchestrate pregnancy. This review focuses on the beneficial effects of MCs on tissue homeostasis and elimination of toxins or venoms. MCs can enhance pathogen clearance in many bacter…