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PloS One 2023A long-term high-fat diet (HFD) causes obesity and changes in renal lipid metabolism and lysosomal dysfunction in mice, causing renal damage. Sodium-glucose...
A long-term high-fat diet (HFD) causes obesity and changes in renal lipid metabolism and lysosomal dysfunction in mice, causing renal damage. Sodium-glucose co-transporter inhibitors, including phlorizin, exert nephroprotective effects in patients with chronic kidney disease, but the underlying mechanism remains unclear. A HFD or standard diet was fed to adult C57BL/6J male mice, and phlorizin was administered. Lamellar body components of the proximal tubular epithelial cells (PTECs) were investigated. After phlorizin administration in HFD-fed mice, sphingomyelin and ceramide in urine and tissues were assessed and label-free quantitative proteomics was performed using kidney tissue samples. Mitochondrial elongation by fusion was effective in the PTECs of HFD-fed obese mice under phlorizin administration, and many lamellar bodies were found in the apical portion of the S2 segment of the proximal tubule. Phlorizin functioned as a diuretic, releasing lamellar bodies from the apical membrane of PTECs and clearing the obstruction in nephrons. The main component of the lamellar bodies was sphingomyelin. On the first day of phlorizin administration in HFD-fed obese mice, the diuretic effect was increased, and more sphingomyelin was excreted through urine than in vehicle-treated mice. The expressions of three peroxisomal β-oxidation proteins involved in fatty acid metabolism were downregulated after phlorizin administration in the kidneys of HFD-fed mice. Fatty acid elongation protein levels increased with phlorizin administration, indicating an increase in long-chain fatty acids. Lamellar bodies accumulated in the proximal renal tubule of the S2 segment of the HFD-fed mice, indicating that the urinary excretion of lamellar bodies has nephroprotective effects.
Topics: Male; Animals; Mice; Diet, High-Fat; Mice, Obese; Sphingomyelins; Phlorhizin; Mice, Inbred C57BL; Fatty Acids; Symporters; Glucose; Sodium
PubMed: 36780539
DOI: 10.1371/journal.pone.0281770 -
Laboratory Investigation; a Journal of... Mar 2000Surfactant protein B (SP-B) -/- mice die of lethal respiratory distress syndrome shortly after birth. Alveolar type II epithelial cells in SP-B-deficient mice are...
Surfactant protein B (SP-B) -/- mice die of lethal respiratory distress syndrome shortly after birth. Alveolar type II epithelial cells in SP-B-deficient mice are characterized by a complete absence of lamellar bodies, the intracellular storage form of pulmonary surfactant, and the presence of inclusions containing numerous small vesicles and electron-dense masses. The present study was undertaken to characterize the formation of these inclusions during fetal lung development and clarify their relationship to lamellar bodies. In wild-type and SP-B +/- mice, small lamellar bodies with loosely organized lamellae and distinct limiting membranes were first detected on day 16 to 16.5 of gestation. SP-B -/- mice were readily identified on day 16 by the absence of immature lamellar bodies, the appearance of vesicular inclusions similar to those previously described in late gestation SP-B -/- mice, and the accumulation of misprocessed SP-C protein. Vesicular inclusions were rarely detected in SP-B +/- mice and were never detected in wild-type littermates. Classical multivesicular bodies were observed fusing with lamellar bodies in wild-type mice, and with the vesicular inclusions in SP-B -/- mice that occasionally contained a few membrane lamellae. On day 18, the airways of SP-B -/- mice lacked tubular myelin and were filled with vesicles and electron-dense masses, suggesting that the contents of the vesicular inclusions were secreted. Taken together, these observations suggest that vesicular inclusions in SP-B -/- mice are disorganized lamellar bodies in which the absence of SP-B leads to failure to package surfactant phospholipids into concentric lamellae.
Topics: Animals; Lung; Mice; Mice, Knockout; Proteolipids; Pulmonary Surfactants
PubMed: 10744075
DOI: 10.1038/labinvest.3780044 -
Methods in Molecular Biology (Clifton,... 2022Accumulation of lysosomal phospholipids in cells exposed to cationic amphiphilic drugs is characteristic of drug-induced phospholipidosis. The morphological hallmark of...
Accumulation of lysosomal phospholipids in cells exposed to cationic amphiphilic drugs is characteristic of drug-induced phospholipidosis. The morphological hallmark of phospholipidosis is the appearance of unicentric or multicentric-lamellar bodies when viewed under an electron microscope (EM). The EM method, the gold standard of detecting cellular phospholipidosis, has downsides, namely, low-throughput, high-costs, and unsuitability for screening a large chemical library. This chapter describes a cell-based high-content phospholipidosis assay using the LipidTOX reagent in a high-throughput screening (HTS) platform. This assay has been optimized and validated in HepG2 and HepRG cells, and miniaturized into a 1536-well plate, thus can be used for high-throughput screening (HTS) to identify chemical compounds that induce phospholipidosis.
Topics: Biological Assay; High-Throughput Screening Assays; Humans; Lipidoses; Lysosomal Storage Diseases; Phospholipids
PubMed: 35294757
DOI: 10.1007/978-1-0716-2213-1_8 -
Frontiers in Immunology 2023Pulmonary surfactant (PS), a complex mixture of lipids and proteins, is essential for maintaining proper lung function. It reduces surface tension in the alveoli,... (Review)
Review
Pulmonary surfactant (PS), a complex mixture of lipids and proteins, is essential for maintaining proper lung function. It reduces surface tension in the alveoli, preventing collapse during expiration and facilitating re-expansion during inspiration. Additionally, PS has crucial roles in the respiratory system's innate defense and immune regulation. Dysfunction of PS contributes to various respiratory diseases, including neonatal respiratory distress syndrome (NRDS), adult respiratory distress syndrome (ARDS), COVID-19-associated ARDS, and ventilator-induced lung injury (VILI), among others. Furthermore, PS alterations play a significant role in chronic lung diseases such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). The intracellular stage involves storing and releasing a specialized subcellular organelle known as lamellar bodies (LB). The maturation of these organelles requires coordinated signaling to organize their intracellular organization in time and space. LB's intracellular maturation involves the lipid composition and critical processing of surfactant proteins to achieve proper functionality. Over a decade ago, the supramolecular organization of lamellar bodies was studied using electron microscopy. In recent years, novel bioimaging tools combining spectroscopy and microscopy have been utilized to investigate the intracellular organization of lamellar bodies temporally and spatially. This short review provides an up-to-date understanding of intracellular LBs. Hyperspectral imaging and phasor analysis have allowed identifying specific transitions in LB's hydration, providing insights into their membrane dynamics and structure. A discussion and overview of the latest approaches that have contributed to a new comprehension of the trafficking and structure of lamellar bodies is presented.
Topics: Adult; Infant, Newborn; Humans; Pulmonary Surfactants; COVID-19; Pulmonary Disease, Chronic Obstructive; Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn
PubMed: 37638003
DOI: 10.3389/fimmu.2023.1250350 -
Cell Reports Dec 2020Autophagy is an intracellular degradation system, but its physiological functions in vertebrates are not yet fully understood. Here, we show that autophagy is required...
Autophagy is an intracellular degradation system, but its physiological functions in vertebrates are not yet fully understood. Here, we show that autophagy is required for inflation of air-filled organs: zebrafish swim bladder and mouse lung. In wild-type zebrafish swim bladder and mouse lung type II pulmonary epithelial cells, autophagosomes are formed and frequently fuse with lamellar bodies. The lamellar body is a lysosome-related organelle that stores a phospholipid-containing surfactant complex that lines the air-liquid interface and reduces surface tension. We find that autophagy is critical for maturation of the lamellar body. Accordingly, atg-deficient zebrafish fail to maintain their position in the water, and type-II-pneumocyte-specific Fip200-deficient mice show neonatal lethality with respiratory failure. Autophagy suppression does not affect synthesis of the surfactant phospholipid, suggesting that autophagy supplies lipids and membranes to lamellar bodies. These results demonstrate an evolutionarily conserved role of autophagy in lamellar body maturation.
Topics: Air Sacs; Alveolar Epithelial Cells; Animals; Autophagy; Autophagy-Related Proteins; Epithelial Cells; Female; Lung; Male; Mice; Mice, Inbred C57BL; Organelles; Pulmonary Surfactants; Zebrafish; Zebrafish Proteins
PubMed: 33296658
DOI: 10.1016/j.celrep.2020.108477 -
The International Journal of... 2017Studies on amphioxus, representing the most basal group of chordates, can give insights into the evolution of vertebrate traits. The present review of amphioxus research... (Review)
Review
Studies on amphioxus, representing the most basal group of chordates, can give insights into the evolution of vertebrate traits. The present review of amphioxus research is focused on the physiology of light-guided behavior as well as on the fine structure, molecular biology, and electrophysiology of the nervous system, with special attention being given to the photoreceptive organs. The amphioxus visual system is especially interesting because four types of receptors are involved in light detection - dorsal ocelli and Joseph cells (both rhabdomeric photoreceptors) and the frontal eye and lamellar body (both ciliary photoreceptors). Here, we consider how the available information on photoreceptive organs and light-guided behavior in amphioxus helps generate hypotheses about the history of these features during chordate and subsequently vertebrate evolution.
Topics: Animals; Circadian Rhythm; Evolution, Molecular; Lancelets; Opsins; Photoreceptor Cells; Photoreceptor Cells, Vertebrate; Vertebrates; Vision, Ocular
PubMed: 29319115
DOI: 10.1387/ijdb.170230zk -
Insects Sep 2013Brevibacillus laterosporus, a bacterium characterized by the production of a unique canoe-shaped lamellar body attached to one side of the spore, is a natural inhabitant... (Review)
Review
Brevibacillus laterosporus, a bacterium characterized by the production of a unique canoe-shaped lamellar body attached to one side of the spore, is a natural inhabitant of water, soil and insects. Its biopesticidal potential has been reported against insects in different orders including Coleoptera, Lepidoptera, Diptera and against nematodes and mollusks. In addition to its pathogenicity against invertebrates, different B. laterosporus strains show a broad-spectrum antimicrobial activity including activity against phytopathogenic bacteria and fungi. A wide variety of molecules, including proteins and antibiotics, have been associated with the observed pathogenicity and mode of action. Before being considered as a biological control agent against plant pathogens, the antifungal and antibacterial properties of certain B. laterosporus strains have found medical interest, associated with the production of antibiotics with therapeutic effects. The recent whole genome sequencing of this species revealed its potential to produce polyketides, nonribosomal peptides, and toxins. Another field of growing interest is the use of this bacterium for bioremediation of contaminated sites by exploiting its biodegradation properties. The aim of the present review is to gather and discuss all recent findings on this emerging entomopathogen, giving a wider picture of its complex and broad-spectrum biocontrol activity.
PubMed: 26462431
DOI: 10.3390/insects4030476 -
The Journal of Investigative Dermatology Jul 1983Since 1967, major advances have been made in procedures to isolate and maintain keratinocytes in liquid medium. Human keratinocytes and those from several laboratory... (Review)
Review
Since 1967, major advances have been made in procedures to isolate and maintain keratinocytes in liquid medium. Human keratinocytes and those from several laboratory animal species may now be isolated from skin either by direct trypsinization of minces, from split-thickness skin following the separation of the epidermis from the dermis, or from the outgrowth from tissue explanted in liquid medium. Isolated keratinocytes display several distinct stages leading to terminal maturation. These include attachment, spreading, reassociation, multiplication, and maturation. Conditions under which each of these stages can be blocked are known and thus provide an opportunity to observe and characterize the biochemical and morphologic changes at each stage of maturation. Although keratinocytes in liquid simulate many of the typical and important characteristics observed in these cells in vivo, the conditions required to reproduce other important functions of keratinocytes have not yet been defined. These functions include the synthesis of basement membranes, lamellar bodies, and keratohyaline granules and the appropriate alignment of lipids and proteins in the completely keratinized cell.
Topics: Calcium; Cell Count; Cell Division; Cell Movement; Cell Separation; Culture Media; Cyclic AMP; Dexamethasone; Epidermal Cells; Epidermal Growth Factor; Epidermis; Humans; Hydrocortisone; Hydrogen-Ion Concentration; Methods; Selenium
PubMed: 6306116
DOI: 10.1111/1523-1747.ep12540284 -
Frontiers in Cellular Neuroscience Oct 2013In recent years, P2X receptors have attracted increasing attention as regulators of exocytosis and cellular secretion. In various cell types, P2X receptors have been... (Review)
Review
In recent years, P2X receptors have attracted increasing attention as regulators of exocytosis and cellular secretion. In various cell types, P2X receptors have been found to stimulate vesicle exocytosis directly via Ca(2+) influx and elevation of the intracellular Ca(2+) concentration. Recently, a new role for P2X4 receptors as regulators of secretion emerged. Exocytosis of lamellar bodies (LBs), large storage organelles for lung surfactant, results in a local, fusion-activated Ca(2+) entry (FACE) in alveolar type II epithelial cells. FACE is mediated via P2X4 receptors that are located on the limiting membrane of LBs and inserted into the plasma membrane upon exocytosis of LBs. The localized Ca(2+) influx at the site of vesicle fusion promotes fusion pore expansion and facilitates surfactant release. In addition, this inward-rectifying cation current across P2X4 receptors mediates fluid resorption from lung alveoli. It is hypothesized that the concomitant reduction in the alveolar lining fluid facilitates insertion of surfactant into the air-liquid interphase thereby "activating" it. These findings constitute a novel role for P2X4 receptors in regulating vesicle content secretion as modulators of the secretory output during the exocytic post-fusion phase.
PubMed: 24115920
DOI: 10.3389/fncel.2013.00171 -
The Journal of Investigative Dermatology Apr 2019The corneocyte lipid envelope (CLE), a monolayer of ω-hydroxyceramides whose function(s) remain(s) uncertain, is absent in patients with autosomal recessive congenital... (Review)
Review
The corneocyte lipid envelope (CLE), a monolayer of ω-hydroxyceramides whose function(s) remain(s) uncertain, is absent in patients with autosomal recessive congenital ichthyoses with mutations in enzymes that regulate epidermal lipid synthesis. Secreted lipids fail to transform into lamellar membranes in certain autosomal recessive congenital ichthyosis epidermis, suggesting the CLE provides a scaffold for the extracellular lamellae. However, because cornified envelopes are attenuated in these autosomal recessive congenital ichthyoses, the CLE may also provide a scaffold for subjacent cornified envelope formation, evidenced by restoration of cornified envelopes after CLE rescue. We provide multiple lines of evidence that the CLE originates as lamellar body-limiting membranes fuse with the plasma membrane: (i) ABCA12 patients and Abca12 mice display normal CLEs; (ii) CLEs are normal in Netherton syndrome, despite destruction of secreted LB contents; (iii) CLEs are absent in VSP33B-negative patients; (iv) limiting membranes of lamellar bodies are defective in lipid-synthetic autosomal recessive congenital ichthyoses; and (v) lipoxygenases, lipase activity, and LIPN co-localize within putative lamellar bodies.
Topics: Animals; DNA; DNA Mutational Analysis; Humans; Ichthyosiform Erythroderma, Congenital; Lipid Metabolism; Lipids; Mutation; Skin
PubMed: 30471252
DOI: 10.1016/j.jid.2018.11.005