Endocytosis of Sugars in Embryonic Skeletal Tissues in Organ Culture

1969 ◽  
Vol 4 (1) ◽  
pp. 139-154
Author(s):  
J. T. DINGLE ◽  
HONOR B. FELL ◽  
AUDREY M. GLAUERT
Keyword(s):  
Organ Culture ◽  
Lysosomal Enzymes ◽  
Articular Chondrocytes ◽  
Appreciable Amount ◽  
Neutral Salt ◽  
Normal Medium ◽  
Limb Bone ◽  
Cytoplasmic Vacuolation ◽  
Golgi Region

Cultivation of limb-bone rudiments in medium containing various non-metabolizable or poorly metabolizable sugars caused vacuolation of the perichondrial and articular cells and was accompanied by an increased synthesis and profuse secretion of lysosomal enzymes. Experiments with [14C] dextran indicated that the cytoplasmic vacuolation was due not to a higher rate of endocytosis, but rather to an abnormally long persistence of the pinocytotic vacuoles. Metachromatic material was lost from the cartilage only in the immediate vicinity of the vacuolated articular chondrocytes and the amount of hexosamine and hydroxyproline released into the medium was not much increased. However, the hexosamine and hydroxyproline of the sucrose treated rudiments was much more susceptible to extraction with neutral salt than those of paired controls. Sucrose taken up by the cells was liberated when the rudiments were returned to normal medium; this release, unlike the secretion of lysosomal enzymes, was unaffected by the presence of hydrocortisone. It is probable that the primary lysosornes, formed in the enlarged Golgi region, are the vehicles for the secretion of lysosomal enzymes. No appreciable amount of enzyrnic activity was released into the medium from rudiments grown in the presence of 0.08 M sucrose, before 36 h; at, or just before this time, however, a net increase in synthesis of enzyme was observed. The role of endocytosis in the resorption of skeletal matrix is discussed.

The Role of Soft Connective Tissue in the Response of Pig Articular Cartilage in Organ Culture to Excess of Retinol

1973 ◽  
Vol 13 (1) ◽  
pp. 205-219
Author(s):  
M. E. J. BARRATT
Keyword(s):  
Articular Cartilage ◽  
Connective Tissue ◽  
Organ Culture ◽  
Growing Pigs ◽  
Cartilage Matrix ◽  
Normal Medium ◽  
Chondroid Tissue ◽  
Extensive Degradation

The action of excess retinol on articular cartilage from growing pigs was studied in organ culture. Retinol had little or no effect on explants of articular cartilage alone, but if the explants were cut so as to include some of the marrow tissue in the invasion cavities, or were cultivated near or in contact with capsular tissue, retinol caused extensive degradation of the cartilage matrix, as indicated by loss of metachromatic staining properties. Many chondrocytes were released from their capsules and assumed a fibroblast-like form. Two types of regeneration were seen. In control explants that included part of the invasion zone, cells below the explant laid down a metachromatic matrix; in similar explants cultured in the presence of retinol, a non-metachromatic osteoid-like tissue was formed at this site. There was little recovery when retinol-treated explants were transferred to normal medium, although both osteoid and chondroid tissue were sometimes regenerated.

scholarly journals Role of LAMP-2 in Lysosome Biogenesis and Autophagy

2002 ◽  
Vol 13 (9) ◽  
pp. 3355-3368 ◽  
Author(s):  
Eeva-Liisa Eskelinen ◽  
Anna Lena Illert ◽  
Yoshitaka Tanaka ◽  
Günter Schwarzmann ◽  
Judith Blanz ◽  
...  
Keyword(s):  
Half Life ◽  
Lysosomal Enzymes ◽  
State Level ◽  
Autophagic Vacuoles ◽  
Lysosome Biogenesis ◽  
Golgi Region ◽  
Activity Measurements ◽  
Phenotype Analysis ◽  
Mannose 6 Phosphate

In LAMP-2–deficient mice autophagic vacuoles accumulate in many tissues, including liver, pancreas, muscle, and heart. Here we extend the phenotype analysis using cultured hepatocytes. In LAMP-2–deficient hepatocytes the half-life of both early and late autophagic vacuoles was prolonged as evaluated by quantitative electron microscopy. However, an endocytic tracer reached the autophagic vacuoles, indicating delivery of endo/lysosomal constituents to autophagic vacuoles. Enzyme activity measurements showed that the trafficking of some lysosomal enzymes to lysosomes was impaired. Immunoprecipitation of metabolically labeled cathepsin D indicated reduced intracellular retention and processing in the knockout cells. The steady-state level of 300-kDa mannose 6-phosphate receptor was slightly lower in LAMP-2–deficient hepatocytes, whereas that of 46-kDa mannose 6-phosphate receptor was decreased to 30% of controls due to a shorter half-life. Less receptor was found in the Golgi region and in vesicles and tubules surrounding multivesicular endosomes, suggesting impaired recycling from endosomes to the Golgi. More receptor was found in autophagic vacuoles, which may explain its shorter half-life. Our data indicate that in hepatocytes LAMP-2 deficiency either directly or indirectly leads to impaired recycling of 46-kDa mannose 6-phosphate receptors and partial mistargeting of a subset of lysosomal enzymes. Autophagic vacuoles may accumulate due to impaired capacity for lysosomal degradation.

Fibrin Formation: The Role of the Fibrinogen-Fibrin Monomer Complex

1976 ◽  
Vol 36 (01) ◽  
pp. 037-048 ◽  
Author(s):  
Eric P. Brass ◽  
Walter B. Forman ◽  
Robert V. Edwards ◽  
Olgierd Lindan
Keyword(s):  
Particle Size ◽  
Induction Period ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Appreciable Amount ◽  
Buffer System ◽  
Homeostatic Mechanism ◽  
Fibrin Formation ◽  
Fibrin Monomer

SummaryThe process of fibrin formation using highly purified fibrinogen and thrombin was studied using laser fluctuation spectroscopy, a method that rapidly determines particle size in a solution. Two periods in fibrin clot formation were noted: an induction period during which no fibrin polymerization occurred and a period of rapid increase in particle size. Direct measurement of fibrin monomer polymerization and fibrinopeptide release showed no evidence of an induction period. These observations were best explained by a kinetic model for fibrin clot formation incorporating a reversible fibrinogen-fibrin monomer complex. In this model, the complex serves as a buffer system during the earliest phase of fibrin formation. This prevents the accumulation of free polymerizable fibrin monomer until an appreciable amount of fibrinogen has reacted with thrombin, at which point the fibrin monomer level rises rapidly and polymerization proceeds. Clinically, the complex may be a homeostatic mechanism preventing pathological clotting during periods of elevated fibrinogen.

THE ROLE OF LYSOSOMAL ENZYMES IN THE PATHOGENESIS OF SHOCK. 2, THE ORIGIN OF PLASMA LYSOSOMAL HYDROLASES IN SHOCK

1979 ◽  
Vol 29 (1) ◽  
pp. 33-38
Author(s):  
RYO OGAWA ◽  
TAKASUKE IMAI ◽  
TATSUSHI FUJITA
Keyword(s):  
Lysosomal Enzymes ◽  
Lysosomal Hydrolases

scholarly journals Proteomic Analysis of Synovial Fibroblasts and Articular Chondrocytes Co-Cultures Reveals Valuable VIP-Modulated Inflammatory and Degradative Proteins in Osteoarthritis

2021 ◽  
Vol 22 (12) ◽  
pp. 6441
Author(s):  
Selene Pérez-García ◽  
Valentina Calamia ◽  
Tamara Hermida-Gómez ◽  
Irene Gutiérrez-Cañas ◽  
Mar Carrión ◽  
...  
Keyword(s):  
Isotope Labeling ◽  
Articular Chondrocytes ◽  
Synovial Fibroblasts ◽  
Immune Mediators ◽  
Cartilage Extracellular Matrix ◽  
Fibronectin Fragments ◽  
Ecm Degradation ◽  
Key Events ◽  
First Time

Osteoarthritis (OA) is the most common musculoskeletal disorder causing a great disability and a reduction in the quality of life. In OA, articular chondrocytes (AC) and synovial fibroblasts (SF) release innate-derived immune mediators that initiate and perpetuate inflammation, inducing cartilage extracellular matrix (ECM) degradation. Given the lack of therapies for the treatment of OA, in this study, we explore biomarkers that enable the development of new therapeutical approaches. We analyze the set of secreted proteins in AC and SF co-cultures by stable isotope labeling with amino acids (SILAC). We describe, for the first time, 115 proteins detected in SF-AC co-cultures stimulated by fibronectin fragments (Fn-fs). We also study the role of the vasoactive intestinal peptide (VIP) in this secretome, providing new proteins involved in the main events of OA, confirmed by ELISA and multiplex analyses. VIP decreases proteins involved in the inflammatory process (CHI3L1, PTX3), complement activation (C1r, C3), and cartilage ECM degradation (DCN, CTSB and MMP2), key events in the initiation and progression of OA. Our results support the anti-inflammatory and anti-catabolic properties of VIP in rheumatic diseases and provide potential new targets for OA treatment.

scholarly journals A Novel Tetrapeptide Derivative Exhibits In Vitro Inhibition of Neutrophil-Derived Reactive Oxygen Species and Lysosomal Enzymes Release

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sumitra Miriyala ◽  
Manikandan Panchatcharam ◽  
Meera Ramanujam ◽  
Rengarajulu Puvanakrishnan
Keyword(s):  
Reactive Oxygen Species ◽  
Superoxide Anion ◽  
Lysosomal Enzymes ◽  
Reactive Oxygen ◽  
Peptide Sequence ◽  
Ros Generation ◽  
Oxygen Species ◽  
Complement Factors

Neutrophil infiltration plays a major role in the pathogenesis of myocardial injury. Oxidative injury is suggested to be a central mechanism of the cellular damage after acute myocardial infarction. This study is pertained to the prognostic role of a tetrapeptide derivative PEP1261 (BOC-Lys(BOC)-Arg-Asp-Ser(tBu)-OtBU), a peptide sequence (39–42) of lactoferrin, studied in the modulation of neutrophil functions in vitro by measuring the reactive oxygen species (ROS) generation, lysosomal enzymes release, and enhanced expression of C proteins. The groundwork experimentation was concerned with the isolation of neutrophils from the normal and acute myocardial infarct rats to find out the efficacy of PEP1261 in the presence of a powerful neutrophil stimulant, phorbol 12-myristate 13 acetate (PMA). Stimulation of neutrophils with PMA resulted in an oxidative burst of superoxide anion and enhanced release of lysosomal enzymes and expression of complement proteins. The present study further demonstrated that the free radicals increase the complement factors in the neutrophils confirming the role of ROS. PEP1261 treatment significantly reduced the levels of superoxide anion and inhibited the release of lysosomal enzymes in the stimulated control and infarct rat neutrophils. This study demonstrated that PEP1261 significantly inhibited the effect on the ROS generation as well as the mRNA synthesis and expression of the complement factors in neutrophils isolated from infarct heart.

scholarly journals Retrograde Transport from the Pre-Golgi Intermediate Compartment and the Golgi Complex Is Affected by the Vacuolar H+-ATPase Inhibitor Bafilomycin A1

1998 ◽  
Vol 9 (12) ◽  
pp. 3561-3578 ◽  
Author(s):  
Harri Palokangas ◽  
Ming Ying ◽  
Kalervo Väänänen ◽  
Jaakko Saraste
Keyword(s):  
Brefeldin A ◽  
Retrograde Transport ◽  
Small Gtpase ◽  
Bafilomycin A1 ◽  
Atpase Inhibitor ◽  
Marker Proteins ◽  
Golgi Region ◽  
Intermediate Compartment ◽  
Acidic Compartments

The effect of the vacuolar H+-ATPase inhibitor bafilomycin A1 (Baf A1) on the localization of pre-Golgi intermediate compartment (IC) and Golgi marker proteins was used to study the role of acidification in the function of early secretory compartments. Baf A1 inhibited both brefeldin A- and nocodazole-induced retrograde transport of Golgi proteins to the endoplasmic reticulum (ER), whereas anterograde ER-to-Golgi transport remained largely unaffected. Furthermore, p58/ERGIC-53, which normally cycles between the ER, IC, and cis-Golgi, was arrested in pre-Golgi tubules and vacuoles, and the number of p58-positive ∼80-nm Golgi (coatomer protein I) vesicles was reduced, suggesting that the drug inhibits the retrieval of the protein from post-ER compartments. In parallel, redistribution of β-coatomer protein from the Golgi to peripheral pre-Golgi structures took place. The small GTPase rab1p was detected in short pre-Golgi tubules in control cells and was efficiently recruited to the tubules accumulating in the presence of Baf A1. In contrast, these tubules showed no enrichment of newly synthesized, anterogradely transported proteins, indicating that they participate in retrograde transport. These results suggest that the pre-Golgi structures contain an active H+-ATPase that regulates retrograde transport at the ER–Golgi boundary. Interestingly, although Baf A1 had distinct effects on peripheral pre-Golgi structures, only more central, p58-containing elements accumulated detectable amounts of 3-(2,4-dinitroanilino)-3′-amino-N-methyldipropylamine (DAMP), a marker for acidic compartments, raising the possibility that the lumenal pH of the pre-Golgi structures gradually changes in parallel with their translocation to the Golgi region.

scholarly journals Fructose 1,6-Bisphosphatase: The Role of Lysosomal Enzymes in the Modification of Catalytic and Structural Properties

1973 ◽  
Vol 70 (2) ◽  
pp. 303-305 ◽  
Author(s):  
S. Pontremoli ◽  
E. Melloni ◽  
F. Balestrero ◽  
A. T. Franzi ◽  
A. De Flora ◽  
...  
Keyword(s):  
Structural Properties ◽  
Lysosomal Enzymes ◽  
Fructose 1,6 Bisphosphatase
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