Effect of porcine conceptus secretory proteins on in vitro secretion of prostaglandins-F2α and-E2 from luminal and myometrial surfaces of endometrium from cyclic and pseudopregnant gilts

1991 ◽  
Vol 41 (3) ◽  
pp. 283-301 ◽  
Author(s):  
D.H. Dubois ◽  
F.W. Bazer
Keyword(s):  
Secretory Proteins ◽  
Porcine Conceptus

scholarly journals Sorting and storage during secretory granule biogenesis: looking backward and looking forward

1998 ◽  
Vol 332 (3) ◽  
pp. 593-610 ◽  
Author(s):  
Peter ARVAN ◽  
David CASTLE
Keyword(s):  
Secretory Pathway ◽  
Molecular Mechanisms ◽  
Secretory Granules ◽  
Secretory Proteins ◽  
Membrane Composition ◽  
Granule Formation ◽  
Granule Membrane ◽  
Regulated Secretory Pathway ◽  
Secretory Products

Secretory granules are specialized intracellular organelles that serve as a storage pool for selected secretory products. The exocytosis of secretory granules is markedly amplified under physiologically stimulated conditions. While granules have been recognized as post-Golgi carriers for almost 40 years, the molecular mechanisms involved in their formation from the trans-Golgi network are only beginning to be defined. This review summarizes and evaluates current information about how secretory proteins are thought to be sorted for the regulated secretory pathway and how these activities are positioned with respect to other post-Golgi sorting events that must occur in parallel. In the first half of the review, the emerging role of immature secretory granules in protein sorting is highlighted. The second half of the review summarizes what is known about the composition of granule membranes. The numerous similarities and relatively limited differences identified between granule membranes and other vesicular carriers that convey products to and from the plasmalemma, serve as a basis for examining how granule membrane composition might be established and how its unique functions interface with general post-Golgi membrane traffic. Studies of granule formation in vitro offer additional new insights, but also important challenges for future efforts to understand how regulated secretory pathways are constructed and maintained.

scholarly journals The ER v-SNAREs are required for GPI-anchored protein sorting from other secretory proteins upon exit from the ER

2003 ◽  
Vol 162 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Pierre Morsomme ◽  
Cristina Prescianotto-Baschong ◽  
Howard Riezman
Keyword(s):  
Golgi Complex ◽  
Protein Sorting ◽  
Secretory Proteins ◽  
Rab Gtpase ◽  
Cargo Protein ◽  
Conserved Oligomeric Golgi Complex ◽  
Sorting Process ◽  
Conserved Oligomeric Golgi

Glycosylphosphatidylinositol (GPI)-anchored proteins exit the ER in distinct vesicles from other secretory proteins, and this sorting event requires the Rab GTPase Ypt1p, tethering factors Uso1p, and the conserved oligomeric Golgi complex. Here we show that proper sorting depended on the vSNAREs, Bos1p, Bet1p, and Sec22p. However, the t-SNARE Sed5p was not required for protein sorting upon ER exit. Moreover, the sorting defect observed in vitro with bos1–1 extracts was also observed in vivo and was visualized by EM. Finally, transport and maturation of the GPI-anchored protein Gas1p was specifically affected in a bos1–1 mutant at semirestrictive temperature. Therefore, we propose that v-SNAREs are part of the cargo protein sorting machinery upon exit from the ER and that a correct sorting process is necessary for proper maturation of GPI-anchored proteins.

scholarly journals Mesenchymal stem cells versus their extracellular vesicles in treatment of liver fibrosis: Is it possible to compare?

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Noha Attia ◽  
Yasmine Khalifa ◽  
Dina Rostom ◽  
Mohamed Mashal
Keyword(s):  
Liver Fibrosis ◽  
Extracellular Vesicles ◽  
Therapeutic Strategy ◽  
Secretory Proteins ◽  
Apoptotic Bodies ◽  
Limited Evidence ◽  
In Vivo Models ◽  
Dose Determination

Liver fibrosis (LF) is a worldwide health problem that is associated with a range of complications and high mortality. Due to the scarcity of liver donors, mesenchymal stem cell (MSC) therapy emerged as an alternative therapeutic strategy. However, it is widely accepted that most of the transplanted MSCs exhibit their therapeutic impact mainly via a bystander paracrine (medicinal) capacity. In addition to their secretory proteins, MSCs also produce various types of extracellular vesicles (EVs) that are classified into three main subtypes: microvesicles, exosomes and apoptotic bodies. Thanks to their peculiar cargo composition (e.g., proteins, lipids, and nucleic acids), EVs serve as an advantageous candidate for cell-free therapy. Recently, MSC-derived EVs (MSC-EVs) have gained the podium due to their regenerative and immunomodulatory effect. In mitigation/treatment of LF, a plethora of recent studies have shown the anti-inflammatory, anti-fibrotic and cytoprotective effects of both MSCs and MSC-EVs in various in vitro and in vivo models of LF. However, despite the limited evidence, we sought in this mini review to sort out the established data and formulate several challenging questions that must be answered to pave the way for further clinical applications. One of the major questions to ask is “Which is the best therapeutic approach, MSCs or MSC-EVs?” We tried to highlight how difficult it might be to compare the two approaches while our understanding of both candidates is still deficient. Among the major obstacles against such comparison is the inaccurate equivalent dose determination, the unknown in vivo behavior, and the undetermined lifespan/fate of each. Currently, the fields of MSCs and MSC-EVs seem to be rich in ideas but lacking in appropriate technologies to test these ideas. Nevertheless, continuous efforts are likely to help resolve some of the challenges listed here.

scholarly journals Proteomic Profiling of Mammalian COPII Vesicles

2018 ◽  
Author(s):  
Frank Adolf ◽  
Manuel Rhiel ◽  
Bernd Hessling ◽  
Andrea Hellwig ◽  
Felix T. Wieland
Keyword(s):  
Intracellular Transport ◽  
Spectrometric Analysis ◽  
Secretory Proteins ◽  
Proteomic Profiling ◽  
Vesicular Carriers ◽  
Copii Vesicle ◽  
Cargo Proteins ◽  
Core Proteome ◽  
Copii Vesicles

AbstractIntracellular transport and homeostasis of the endomembrane system in eukaryotic cells depend on formation and fusion of vesicular carriers. COPII vesicles export newly synthesized secretory proteins from the endoplasmic reticulum (ER). They are formed by sequential recruitment of the small GTP binding protein Sar1, the inner coat complex Sec23/24, and the outer coat complex Sec13/31. In order to investigate the roles of mammalian Sec24 isoforms in cargo sorting, we have combined in vitro COPII vesicle reconstitutions with SILAC-based mass spectrometric analysis. This approach enabled us to identify the core proteome of mammalian COPII vesicles. Comparison of the proteomes generated from vesicles with different Sec24 isoforms confirms several established isoform-dependent cargo proteins, and identifies ERGIC1 and CNIH1 as novel Sec24C‐ and Sec24A-specific cargo proteins, respectively. Proteomic analysis of vesicles reconstituted with a Sec24C mutant, bearing a compromised binding site for the ER-to-Golgi QSNARE Syntaxin5, revealed that the SM/Munc18 protein SCFD1 binds to Syntaxin5 prior to its sorting into COPII vesicles. Furthermore, analysis of Sec24D mutants implicated in the development of a syndromic form of osteogenesis imperfecta showed sorting defects for the three ER-to-Golgi QSNAREs Syntaxin5, GS27, and Bet1.

Induction of functional cytodifferentiation in the epithelium of tissue recombinants. I. Homotypic seminal vesicle recombinants

Development ◽  
1989 ◽  
Vol 106 (2) ◽  
pp. 219-234 ◽  
Author(s):  
S.J. Higgins ◽  
P. Young ◽  
J.R. Brody ◽  
G.R. Cunha
Keyword(s):  
Seminal Vesicle ◽  
Time Course ◽  
Full Range ◽  
Seminal Vesicles ◽  
Neonatal Rat ◽  
Secretory Proteins ◽  
Functional Variation ◽  
Adult Rats ◽  
Normal Functional

Functional cytodifferentiation of seminal vesicle epithelium was investigated in tissue recombinants. Neonatal rat and mouse seminal vesicles were separated into epithelium and mesenchyme using trypsin. Epithelium and mesenchyme were then recombined in vitro to form interspecific rat/mouse homotypic recombinants. Growth as renal grafts in adult male athymic mice resulted in seminal vesicle morphogenesis in 70% of the recombinants (the remaining 30% failed to grow). Functional cytodifferentiation was judged by the expression of the major androgen-dependent secretory proteins characteristic of the seminal vesicles of adult rats and mice. Antibodies specific for each of these proteins were used to screen tissue sections by immunocytochemistry and to probe protein extracts by immunoblotting techniques. The heterospecific recombinants synthesized the full range of seminal vesicle secretory proteins that typifies the species providing the epithelium of the recombinant, not the mesenchyme. There was little functional variation between individual recombinants. The time course of development corresponded to that of intact neonatal seminal vesicles grown under the same conditions. Morphogenesis and functional cytodifferentiation were not evident after one week, but were well advanced after two weeks. Seminal vesicle recombinants grown for three weeks were indistinguishable morphologically and functionally from normal adult seminal vesicles. In addition, the ability of adult seminal vesicle epithelium to be induced to proliferate was examined. In association with neonatal seminal vesicle mesenchyme, the epithelium of the adult seminal vesicle proliferated and retained its normal functional activity. Thus, seminal vesicle functional cytodifferentiation can be faithfully reproduced in homotypic tissue recombinants. The methods used in this study will be used to investigate seminal vesicle development in instructive inductions of heterotypic epithelia.

Sulphate metabolism in the exocrine pancreas. II. The production of sulphated macromolecules by the mouse exocrine pancreas

1978 ◽  
Vol 31 (1) ◽  
pp. 199-211
Author(s):  
N.B. Berg
Keyword(s):  
Exocrine Pancreas ◽  
Protein Production ◽  
Pancreatic Tissue ◽  
Radioactive Material ◽  
Secretory Proteins ◽  
Tissue Slices ◽  
Inorganic Sulphate ◽  
Kinetics Of ◽  
Similar Decrease

The types of sulphated macromolecules produced by the exocrine pancrease were investigated. To determine whether this tissue utilized inorganic sulphate for protein production, the in-vitro behaviour of material labelled with 35S-sulphate was compared with material labelled with [3H]leucine (secretory proteins). While incubating tissue slices in the presence of cycloheximide resulted in an immediate and nearly complete inhibition of protein synthesis, a similar decrease in production of sulphated material was not observed until after 2 h of incubation in the presence of the drug. Likewise, the kinetics of pilocarpine-induced discharge of radioactive material from pancreatic slices pulse-labelled with either 3H-Leu. or 35S-sulphate was compared. During the first 90 min of stimulation sulphated macromolecules were detected in chase medium 10–15 min prior to the appearance of 3H-labelled secretory proteins. That in-vitro behaviour of sulphated material differed from radioleucine-labelled material is indicative of the fact that the pancreas utilizes inorganic sulphate for the production of macromolecules other than secretory proteins. Lipid and proteoglycan fractions were prepared from pancreatic tissue 4 h after intraperitoneal injection of radiosulphate. The recovery of a significant amount of radioactivity in both fractions deomonstrated the ability of the pancreas to use inorganic sulphate for the production of both sulphated lipids and sulphated proteoglycans. The possible function of sulphated macromolecules in pancreatic secretion is discussed.

The secretion of proteins in vitro from Xenopus oocytes and their accessory cells: a biochemical and morphological study

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 367-383
Author(s):  
T. J. Mohun ◽  
C. D. Lane ◽  
A. Colman ◽  
C. C. Wylie
Keyword(s):  
Gel Electrophoresis ◽  
Messenger Rna ◽  
Morphological Study ◽  
Xenopus Oocytes ◽  
Secretory Proteins ◽  
Xenopus Laevis Oocytes ◽  
Follicular Cells ◽  
Two Dimensional Gel Electrophoresis ◽  
Accessory Cells

Protein secretion by Xenopus laevis oocytes and their surrounding follicular cells in vitro has been investigated using two-dimensional gel electrophoresis. Viable oocytes, devoid of follicle layers, were prepared by treatment with collagenase; they retain in full their capacity to synthesize, sequester and export secretory proteins following microinjection with heterologous messenger RNA. Both RNA-injected and normal cells export a large number of endogenous oocyte proteins and, as with heterologous secretory translation products, these proteins are found within the oocyte in a vesicle fraction. Electron microscopy indicates that secretion involves exocytotic release of cortical vesicle contents. The follicular cells themselves also seem to contribute a number of proteins to the incubation medium surrounding isolated oocytes, but the presence of follicle layers is not required for the export of endogenous oocyte proteins.

Microtubules facilitate the stimulated secretion of beta-hexosaminidase in lacrimal acinar cells

1998 ◽  
Vol 111 (9) ◽  
pp. 1267-1276 ◽  
Author(s):  
S.R. da Costa ◽  
F.A. Yarber ◽  
L. Zhang ◽  
M. Sonee ◽  
S.F. Hamm-Alvarez
Keyword(s):  
Confocal Microscopy ◽  
Cytochalasin D ◽  
Apical Plasma Membrane ◽  
Secretory Proteins ◽  
Apical Region ◽  
Cell Periphery ◽  
Isolated Cells ◽  
Microtubule Array ◽  
Lacrimal Acinar Cells

Stimulation of lacrimal acini with secretagogues such as carbachol initiates movement and fusion of acinar secretory vesicles with the apical plasma membrane, resulting in release of protein into the nascent tear fluid. Using rabbit lacrimal acini reconstituted in vitro from isolated cells, we have investigated the organization of the apical cytoskeleton and its role in stimulated secretion. Confocal microscopy revealed a microtubule array emanating from the apical region of the acini; the apical region was also enriched in microfilaments and (gamma)-tubulin. Cytokeratin-based intermediate filaments were apically concentrated, and also detected at the cell periphery. Neither confocal microscopy nor biochemical analysis revealed any reorganization of lumenal microfilaments or microtubules which might accompany carbachol-stimulated release of secretory proteins. However, major changes in the acinar microtubule array induced by taxol or nocodazole were correlated with inhibition of carbachol-dependent release of the secreted protein, beta-hexosaminidase. Major changes in lumenal microfilaments induced by jasplakinolide or cytochalasin D did not inhibit the carbachol-dependent release of beta-hexosaminidase; rather, release of beta-hexosaminidase from jasplakinolide- or cytochalasin D-treated carbachol-stimulated acini was markedly increased relative to the release from untreated stimulated acini. Our findings demonstrate that microtubules play a major role in stimulated lacrimal secretion, and suggest a contributory role for microfilaments.

scholarly journals ER/Golgi Intermediates Acquire Golgi Enzymes by Brefeldin a–Sensitive Retrograde Transport in Vitro

1999 ◽  
Vol 147 (7) ◽  
pp. 1457-1472 ◽  
Author(s):  
Chung-Chih Lin ◽  
Harold D. Love ◽  
Jennifer N. Gushue ◽  
John J.M. Bergeron ◽  
Joachim Ostermann
Keyword(s):  
Secretory Pathway ◽  
Mutant Cell ◽  
Brefeldin A ◽  
Retrograde Transport ◽  
Secretory Proteins ◽  
Intermediate Step ◽  
Golgi Stack ◽  
Transport Vesicles ◽  
Direct Fusion

Secretory proteins exit the ER in transport vesicles that fuse to form vesicular tubular clusters (VTCs) which move along microtubule tracks to the Golgi apparatus. Using the well-characterized in vitro approach to study the properties of Golgi membranes, we determined whether the Golgi enzyme NAGT I is transported to ER/Golgi intermediates. Secretory cargo was arrested at distinct steps of the secretory pathway of a glycosylation mutant cell line, and in vitro complementation of the glycosylation defect was determined. Complementation yield increased after ER exit of secretory cargo and was optimal when transport was blocked at an ER/Golgi intermediate step. The rapid drop of the complementation yield as secretory cargo progresses into the stack suggests that Golgi enzymes are preferentially targeted to ER/Golgi intermediates and not to membranes of the Golgi stack. Two mechanisms for in vitro complementation could be distinguished due to their different sensitivities to brefeldin A (BFA). Transport occurred either by direct fusion of preexisting transport intermediates with ER/Golgi intermediates, or it occurred as a BFA-sensitive and most likely COP I–mediated step. Direct fusion of ER/Golgi intermediates with cisternal membranes of the Golgi stack was not observed under these conditions.

Protein production by sheep embryos during the period of maternal recognition of pregnancy

1986 ◽  
Vol 64 (9) ◽  
pp. 1223-1228 ◽  
Author(s):  
J. G. Manns ◽  
P. J. Lewing
Keyword(s):  
Protein Production ◽  
Maternal Blood ◽  
Secretory Proteins ◽  
Low Molecular Weight ◽  
Sephadex Column ◽  
Specific Proteins ◽  
The Media ◽  
Maternal Recognition Of Pregnancy ◽  
Molecular Weight Fractions

An embryo must be present in the uterus 12–13 days after estrus to prevent regression of the ovine corpus luteum. The present experiments were designed to determine if embryo-specific secretory proteins could be detected in the maternal blood at the time of maternal recognition of pregnancy. In two experiments, 92 embryos were flushed from 47 ewes at 14–15 days after estrus. Embryos were incubated in vitro for 24 h and the proteins in the media were harvested. Antisera to proteins in both flushing and incubation medium were produced in rabbits. In experiment 1, crude fractions were used for antibody production and radioimmunoassays were established for protein peaks separated on a 1.1 × 75 cm G-100 Sephadex column. Two low molecular weight fractions (EPiv and EPv) appeared to be embryo specific but were not detectable in jugular vein sera of 14- to 15-day pregnant animals. In experiment 2, proteins derived from uterine flushes and from embryo incubations were chromatographed on a 2.5 × 85 cm column of G-100 Sephadex. The protein peaks were measured, pooled, lyophilized, and used for immunization of rabbits. As in experiment 1, antisera were generated, some of which seemed to be directed against embryo-specific proteins. However, we could not detect these fractions in the uterine vein blood of pregnant animals. Thus, embryo-specific proteins are either confined to the uterus or they appear in the blood in quantities that are undetectable with our assay system.

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