scholarly journals Vibrodissociation method for isolation of defined nephron segments from human and rodent kidneys

2019 ◽  
Vol 317 (5) ◽  
pp. F1398-F1403 ◽  
Author(s):  
Elena Isaeva ◽  
Mykhailo Fedoriuk ◽  
Ruslan Bohovyk ◽  
Christine A. Klemens ◽  
Sherif Khedr ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Current Knowledge ◽  
Cell Types ◽  
Specific Cell ◽  
Renal Tubules ◽  
Gene Markers ◽  
Nephron Segments ◽  
Nephron Segment ◽  
Cell Energy ◽  
Health And Disease

Our current knowledge of the properties of renal ion channels responsible for electrolytes and cell energy homeostasis mainly relies on rodent studies. However, it has not been established yet to what extent their characteristics can be generalized to those of humans. The present study was designed to develop a standardized protocol for the isolation of well-preserved glomeruli and renal tubules from rodent and human kidneys and to assess the functional suitability of the obtained materials for physiological studies. Separation of nephron segments from human and rodent kidneys was achieved using a novel vibrodissociation technique. The integrity of isolated renal tubules and glomeruli was probed via electrophysiological analysis and fluorescence microscopy, and the purity of the collected fractions was confirmed using quantitative RT-PCR with gene markers for specific cell types. The developed approach allows rapid isolation of well-preserved renal tubules and glomeruli from human and rodent kidneys amenable for electrophysiological, Ca2+ imaging, and omics studies. Analysis of the basic electrophysiological parameters of major K+ and Na+ channels expressed in human cortical collecting ducts revealed that they exhibited similar biophysical properties as previously reported in rodent studies. Using vibrodissociation for nephron segment isolation has several advantages over existing techniques: it is less labor intensive, requires little to no enzymatic treatment, and produces large quantities of well-preserved experimental material in pure fractions. Applying this method for the separation of nephron segments from human and rodent kidneys may be a powerful tool for the indepth assessment of kidney function in health and disease.

scholarly journals Rho GTPases as Key Molecular Players within Intestinal Mucosa and GI Diseases

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 66
Author(s):  
Rashmita Pradhan ◽  
Phuong A. Ngo ◽  
Luz d. C. Martínez-Sánchez ◽  
Markus F. Neurath ◽  
Rocío López-Posadas
Keyword(s):  
Intestinal Mucosa ◽  
Rho Gtpases ◽  
Current Knowledge ◽  
Cell Types ◽  
Effector Proteins ◽  
Special Focus ◽  
Specific Cell ◽  
Rho Proteins

Rho proteins operate as key regulators of the cytoskeleton, cell morphology and trafficking. Acting as molecular switches, the function of Rho GTPases is determined by guanosine triphosphate (GTP)/guanosine diphosphate (GDP) exchange and their lipidation via prenylation, allowing their binding to cellular membranes and the interaction with downstream effector proteins in close proximity to the membrane. A plethora of in vitro studies demonstrate the indispensable function of Rho proteins for cytoskeleton dynamics within different cell types. However, only in the last decades we have got access to genetically modified mouse models to decipher the intricate regulation between members of the Rho family within specific cell types in the complex in vivo situation. Translationally, alterations of the expression and/or function of Rho GTPases have been associated with several pathological conditions, such as inflammation and cancer. In the context of the GI tract, the continuous crosstalk between the host and the intestinal microbiota requires a tight regulation of the complex interaction between cellular components within the intestinal tissue. Recent studies demonstrate that Rho GTPases play important roles for the maintenance of tissue homeostasis in the gut. We will summarize the current knowledge on Rho protein function within individual cell types in the intestinal mucosa in vivo, with special focus on intestinal epithelial cells and T cells.

The underground life of homeodomain-leucine zipper transcription factors

2021 ◽  
Author(s):  
Perotti M F ◽  
Arce A L ◽  
R L Chan
Keyword(s):  
Transcription Factors ◽  
Root Development ◽  
Leucine Zipper ◽  
Current Knowledge ◽  
Expression Patterns ◽  
Large Family ◽  
Cell Types ◽  
Structural Features ◽  
Specific Cell ◽  
High Plasticity

Abstract Roots are the anchorage organs of plants, responsible for water and nutrient uptake, exhibiting high plasticity. Root architecture is driven by the interactions of biomolecules, including transcription factors (TFs) and hormones that are crucial players regulating root plasticity. Multiple TF families are involved in root development; some, such as ARFs and LBDs, have been well characterized, whereas others remain less investigated. In this review, we synthesize the current knowledge about the involvement of the large family of homeodomain-leucine zipper (HD-Zip) TFs in root development. This family is divided into four subfamilies (I to IV), mainly according to structural features, such as additional motifs aside from HD-Zip, as well as their size, gene structure, and expression patterns. We explored and analyzed public databases and the scientific literature regarding HD-Zip TFs in Arabidopsis and other species. Most members of the four HD-Zip subfamilies are expressed in specific cell types and several ones from each group have assigned functions in root development. Notably, a high proportion of the studied proteins are part of intricate regulation pathways involved in primary and lateral root growth and development.

Rat liver endothelial cell glutamine transporter and glutaminase expression contrast with parenchymal cells

1999 ◽  
Vol 276 (3) ◽  
pp. G743-G750 ◽  
Author(s):  
Rüdiger Lohmann ◽  
Wiley W. Souba ◽  
Barrie P. Bode
Keyword(s):  
Endothelial Cells ◽  
Amino Acid ◽  
Cell Types ◽  
Male Rats ◽  
Specific Cell ◽  
Liver Endothelial Cell ◽  
Glutamine Transporter ◽  
Health And Disease ◽  
Parenchymal Cells ◽  
Functional Analyses

Despite the central role of the liver in glutamine homeostasis in health and disease, little is known about the mechanism by which this amino acid is transported into sinusoidal endothelial cells, the second most abundant hepatic cell type. To address this issue, the transport ofl-glutamine was functionally characterized in hepatic endothelial cells isolated from male rats. On the basis of functional analyses, including kinetics, cation substitution, and amino acid inhibition, it was determined that a Na+-dependent carrier distinct from system N in parenchymal cells, with properties of system ASC or B0, mediated the majority of glutamine transport in hepatic endothelial cells. These results were supported by Northern blot analyses that showed expression of the ATB0 transporter gene in endothelial but not parenchymal cells. Concurrently, it was determined that, whereas both cell types express glutamine synthetase, hepatic endothelial cells express the kidney-type glutaminase isozyme in contrast to the liver-type isozyme in parenchymal cells. This represents the first report of ATB0 and kidney-type glutaminase isozyme expression in the liver, observations that have implications for roles of specific cell types in hepatic glutamine homeostasis in health and disease.

Functional segmentation of the mammalian nephron

1981 ◽  
Vol 241 (3) ◽  
pp. F203-F218 ◽  
Author(s):  
H. R. Jacobson
Keyword(s):  
Biochemical Analysis ◽  
Epithelial Transport ◽  
Cell Types ◽  
Transport Processes ◽  
Renal Physiology ◽  
Hormonal Responses ◽  
Nephron Segments ◽  
New Information ◽  
Nephron Segment

Although each of the major experimental techniques applied to the study of renal physiology has provided its fair share of new information, the technique of in vitro microperfusion of nephron segments is notable for two major contributions. First, it has supplied a more direct and controlled means of studying epithelial transport processes, some of which already have helped us to understand certain aspects of kidney function and others of which have yet to find their application in unraveling the mysteries of the kidney. Second, in the process of delineating these transport characteristics, it has served to emphasize the epithelial specialization present in the kidney, providing functional counterparts to the already recognized anatomic heterogeneity present in the kidney. In this second role microperfusion has spawned the application of biochemical analysis of the hormonal responses of various nephron segments and contributed to the impetus for work in culturing the various cell types present in each nephron segment. This review outlines the functional characteristics of the 11 major segments of the nephron, incorporating what has been learned from some of the biochemical work on hormone response and correlating the latter with transport events.

Regulatory T Cell Development

2020 ◽  
Vol 38 (1) ◽  
pp. 421-453 ◽  
Author(s):  
Peter A. Savage ◽  
David E.J. Klawon ◽  
Christine H. Miller
Keyword(s):  
Treg Cell ◽  
Current Knowledge ◽  
T Cell Development ◽  
Cell Types ◽  
Treg Cells ◽  
Cell Development ◽  
Clear Understanding ◽  
Major Barrier ◽  
Health And Disease ◽  
Antigen Presenting

Foxp3-expressing CD4+ regulatory T (Treg) cells play key roles in the prevention of autoimmunity and the maintenance of immune homeostasis and represent a major barrier to the induction of robust antitumor immune responses. Thus, a clear understanding of the mechanisms coordinating Treg cell differentiation is crucial for understanding numerous facets of health and disease and for developing approaches to modulate Treg cells for clinical benefit. Here, we discuss current knowledge of the signals that coordinate Treg cell development, the antigen-presenting cell types that direct Treg cell selection, and the nature of endogenous Treg cell ligands, focusing on evidence from studies in mice. We also highlight recent advances in this area and identify key unanswered questions.

F-actin cytoskeletal organization in intervertebral disc health and disease

2007 ◽  
Vol 35 (4) ◽  
pp. 683-685 ◽  
Author(s):  
S. Li ◽  
V.C. Duance ◽  
E.J. Blain
Keyword(s):  
Intervertebral Disc ◽  
Protein Trafficking ◽  
Current Knowledge ◽  
Cell Types ◽  
Filamentous Actin ◽  
Cellular Events ◽  
Disc Cells ◽  
Health And Disease ◽  
Cytoskeletal Networks ◽  
Review Current

The cytoskeleton, which in most cell types, including the intervertebral disc described here, comprises microfilaments, microtubules and intermediate filaments, plays important functions in many fundamental cellular events, including cell division, motility, protein trafficking and secretion. The cytoskeleton is also critical for communication; for example, alterations to the architecture of the F-actin (filamentous actin) cytoskeletal networks can affect communication between the cells and the extracellular matrix, potentially compromising tissue homoeostasis. Although there are limited studies to date, this paper aims to review current knowledge on F-actin cytoskeletal element organization in intervertebral disc cells, how F-actin differs with pathology and its implications for mechanotransduction.

scholarly journals Adipose triglyceride lipase in immune response, inflammation, and atherosclerosis

2012 ◽  
Vol 393 (9) ◽  
pp. 1005-1011 ◽  
Author(s):  
Branislav Radovic ◽  
Elma Aflaki ◽  
Dagmar Kratky
Keyword(s):  
Fatty Acids ◽  
Energy Homeostasis ◽  
Current Knowledge ◽  
Cell Types ◽  
Adipose Triglyceride Lipase ◽  
Hydrolytic Cleavage ◽  
Central Importance ◽  
Energy Substrate ◽  
Triglyceride Lipase ◽  
Esterified Fatty Acids

Abstract Consistent with its central importance in lipid and energy homeostasis, lipolysis occurs in essentially all tissues and cell types, including macrophages. The hydrolytic cleavage of triacylglycerol by adipose triglyceride lipase (ATGL) generates non-esterified fatty acids, which are subsequently used as essential precursors for lipid and membrane synthesis, mediators in cell signaling processes or as energy substrate in mitochondria. This review summarizes the current knowledge concerning the consequences of ATGL deficiency in macrophages with particular emphasis on macrophage (dys)-function, apoptosis, and atherosclerosis.

Physiological roles of claudins in kidney tubule paracellular transport

2017 ◽  
Vol 312 (1) ◽  
pp. F9-F24 ◽  
Author(s):  
Shigeaki Muto
Keyword(s):  
Tight Junctions ◽  
Water Movement ◽  
Current Knowledge ◽  
Paracellular Transport ◽  
Transepithelial Transport ◽  
Leaky Epithelia ◽  
Nephron Segments ◽  
Nephron Segment ◽  
Paracellular Pathways ◽  
Renal Tubular

The paracellular pathways in renal tubular epithelia such as the proximal tubules, which reabsorb the largest fraction of filtered solutes and water and are leaky epithelia, are important routes for transepithelial transport of solutes and water. Movement occurs passively via an extracellular route through the tight junction between cells. The characteristics of paracellular transport vary among different nephron segments with leaky or tighter epithelia. Claudins expressed at tight junctions form pores and barriers for paracellular transport. Claudins are from a multigene family, comprising at least 27 members in mammals. Multiple claudins are expressed at tight junctions of individual nephron segments in a nephron segment-specific manner. Over the last decade, there have been advances in our understanding of the structure and functions of claudins. This paper is a review of our current knowledge of claudins, with special emphasis on their physiological roles in proximal tubule paracellular solute and water transport.

The role of SLAM family receptors in immune cell signalingThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.

2006 ◽  
Vol 84 (6) ◽  
pp. 832-843 ◽  
Author(s):  
Elena A. Ostrakhovitch ◽  
Shawn S.-C. Li
Keyword(s):  
Immune Cells ◽  
Immune Cell ◽  
Current Knowledge ◽  
Critical Role ◽  
Cell Types ◽  
Health And Disease ◽  
Slam Family ◽  
Different Cell Types ◽  
Selection Of

The signaling lymphocyte-activating molecule (SLAM) family immunoreceptors are expressed in a wide array of immune cells, including both T and B lymphocytes. By virtue of their ability to transduce tyrosine phosphorylation signals through the so-called ITSM (immunoreceptor tyrosine-based switch motif) sequences, they play an important part in regulating both innate and adaptive immune responses. The critical role of the SLAM immunoreceptors in mediating normal immune reactions was highlighted in recent findings that SAP, a SLAM-associated protein, modulates the activities of various immune cells through interactions with different members of the SLAM family expressed in these cells. Importantly, mutations or deletions of the sap gene in humans result in the X-linked lymphoproliferative syndrome. In this review, we summarize current knowledge and survey the latest developments in signal transduction events triggered by the activation of SLAM family receptors in different cell types.

scholarly journals Lysosome function in glomerular health and disease

2021 ◽  
Author(s):  
Catherine Meyer-Schwesinger
Keyword(s):  
Current Knowledge ◽  
Lysosomal Storage Diseases ◽  
Cell Types ◽  
Lysosomal Storage ◽  
Membrane Repair ◽  
Glomerular Cell ◽  
Wide Range ◽  
Center Position ◽  
Health And Disease

AbstractThe lysosome represents an important regulatory platform within numerous vesicle trafficking pathways including the endocytic, phagocytic, and autophagic pathways. Its ability to fuse with endosomes, phagosomes, and autophagosomes enables the lysosome to break down a wide range of both endogenous and exogenous cargo, including macromolecules, certain pathogens, and old or damaged organelles. Due to its center position in an intricate network of trafficking events, the lysosome has emerged as a central signaling node for sensing and orchestrating the cells metabolism and immune response, for inter-organelle and inter-cellular signaling and in membrane repair. This review highlights the current knowledge of general lysosome function and discusses these findings in their implication for renal glomerular cell types in health and disease including the involvement of glomerular cells in lysosomal storage diseases and the role of lysosomes in nongenetic glomerular injuries.

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