Expression and processing of prohormones in nonendocrine cells

1993 ◽  
Vol 264 (3) ◽  
pp. G553-G560
Author(s):  
C. J. Dickinson ◽  
T. Takeuchi ◽  
Y. J. Guo ◽  
B. T. Stadler ◽  
T. Yamada

Pancreatic polypeptide (PP) and gastrin are initially synthesized as larger precursors that require posttranslational processing to produce the biologically active peptides. These steps include tryptic cleavage at paired basic residues, their subsequent removal by carboxypeptidase H, and formation of a carboxy-terminal amide moiety via the action of peptidyl-glycine alpha-amidating monooxygenase (PAM). Although these posttranslational processing reactions are presumed to occur primarily in the secretory granule of endocrine cells, nonendocrine cells that do not possess these structures nevertheless are able to posttranslationally process a wide variety of proteins destined for export. In these studies we sought to determine whether the mechanisms for prohormone processing are present in nonendocrine cell lines. We examined two fibroblast cell lines (psi-2, BHK) a hepatocyte cell line (Hepa), and an exocrine pancreatic cell line (AR42J). We used the pZIPneo(SVX) retroviral vector to express cDNA clones encoding human PP and gastrin in the nonendocrine cells. Transfected psi-2, BHK, and Hepa cells produced a precursor of PP that appeared to be secreted constitutively, with little remaining in intracellular stores. Almost no posttranslational processing of the PP precursor was evident in these cells. By contrast, AR42J cells were capable of expressing and storing fully processed and carboxy-terminally amidated PP and gastrin. These data support the notion that the sorting mechanisms in endocrine and exocrine cells are similar and that the posttranslational processing of peptide hormone precursors requires storage in secretory granules.(ABSTRACT TRUNCATED AT 250 WORDS)

1991 ◽  
Vol 260 (5) ◽  
pp. G783-G788 ◽  
Author(s):  
D. F. Daugherty ◽  
C. J. Dickinson ◽  
T. Takeuchi ◽  
D. Bachwich ◽  
T. Yamada

Gastrin, the primary hormonal mediator of postprandial gastric acid secretion, is produced from its precursor progastrin by a series of posttranslational processing reactions including dibasic residue cleavage and carboxyl-terminal alpha-amidation. Progastrin contains three dibasic cleavage signals, Arg57Arg58, Lys74Lys75, and Arg94Arg95, that appear to be cleaved differently in different tissues. Differential processing is a potential means by which the production of biologically active peptides may be regulated in a tissue-specific manner. To study these reactions further, we used the pZipNeo SV(X) retroviral vector to express human gastrin cDNA in a heterologous cell line (MTC 6-23) known to be capable of processing other peptide precursors. The psi 2 packaging cell line transfected with the gastrin cDNA-retroviral construct (pSVXgas) produced progastrin, but no substantial amounts of processed amidated gastrin were detected. amounts of processed amidated gastrin were detected. In contrast, MTC 6-23 cells infected with the viral stock obtained from the supernatant of pSVXgas-transfected psi 2 cells produced carboxyl-terminally amidated gastrin in all of its standard molecular forms, including sulfated and nonsulfated forms of tetratriacontagastrin (G-34), heptadecagastrin (G-17), and tetradecagastrin (G-14). These studies indicate that heterologous endocrine cell lines infected with a retroviral-peptide cDNA construct can serve as useful models for peptide hormone posttranslational processing.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1183
Author(s):  
Cecilia Spedalieri ◽  
Gergo Péter Szekeres ◽  
Stephan Werner ◽  
Peter Guttmann ◽  
Janina Kneipp

Gold nanostars are a versatile plasmonic nanomaterial with many applications in bioanalysis. Their interactions with animal cells of three different cell lines are studied here at the molecular and ultrastructural level at an early stage of endolysosomal processing. Using the gold nanostars themselves as substrate for surface-enhanced Raman scattering, their protein corona and the molecules in the endolysosomal environment were characterized. Localization, morphology, and size of the nanostar aggregates in the endolysosomal compartment of the cells were probed by cryo soft-X-ray nanotomography. The processing of the nanostars by macrophages of cell line J774 differed greatly from that in the fibroblast cell line 3T3 and in the epithelial cell line HCT-116, and the structure and composition of the biomolecular corona was found to resemble that of spherical gold nanoparticles in the same cells. Data obtained with gold nanostars of varied morphology indicate that the biomolecular interactions at the surface in vivo are influenced by the spike length, with increased interaction with hydrophobic groups of proteins and lipids for longer spike lengths, and independent of the cell line. The results will support optimized nanostar synthesis and delivery for sensing, imaging, and theranostics.


1993 ◽  
Vol 21 (2) ◽  
pp. 206-209
Author(s):  
Anders H. G. Andrén ◽  
Anders P. Wieslander

Cytotoxicity, measured as inhibition of cell growth of cultured cell lines, is a widely used method for testing the safety of biomaterials and chemicals. One major technical disadvantage with this method is the continuous routine maintenance of the cell lines. We decided to investigate the possibility of storing stock cultures of fibroblasts (L-929) in an ordinary refrigerator as a means of reducing the routine workload. Stock cultures of the mouse fibroblast cell line L-929 were prepared in plastic vials with Eagle's minimum essential medium. The vials were stored in a refrigerator at 4–10°C for periods of 7–31 days. The condition of the cells after storage was determined as cell viability, cell growth and the toxic response to acrylamide, measured as cell growth inhibition. We found that the L-929 cell line can be stored for 2–3, weeks with a viabilty > 90% and a cell growth of about 95%, compared to L-929 cells grown and subcultured in the normal manner. The results also show that the toxic response to acrylamide, using refrigerator stored L-929 cells, corresponds to that of control L-929 cells. We concluded that it is possible to store L-929 cells in a refrigerator for periods of up to 3 weeks and still use the cells for in vitro cytotoxic assays.


1986 ◽  
Vol 103 (6) ◽  
pp. 2411-2420 ◽  
Author(s):  
E F Plow ◽  
D E Freaney ◽  
J Plescia ◽  
L A Miles

The capacity of cells to interact with the plasminogen activator, urokinase, and the zymogen, plasminogen, was assessed using the promyeloid leukemic U937 cell line and the diploid fetal lung GM1380 fibroblast cell line. Urokinase bound to both cell lines in a time-dependent, specific, and saturable manner (Kd = 0.8-2.0 nM). An active catalytic site was not required for urokinase binding to the cells, and 55,000-mol-wt urokinase was selectively recognized. Plasminogen also bound to the two cell lines in a specific and saturable manner. This interaction occurred with a Kd of 0.8-0.9 microM and was of very high capacity (1.6-3.1 X 10(7) molecules bound/cell). The interaction of plasminogen with both cell types was partially sensitive to trypsinization of the cells and required an unoccupied high affinity lysine-binding site in the ligand. When plasminogen was added to the GM1380 cells, a line with high intrinsic plasminogen activator activity, the bound ligand was comprised of both plasminogen and plasmin. Urokinase, in catalytically active or inactive form, enhanced plasminogen binding to the two cell lines by 1.4-3.3-fold. Plasmin was the predominant form of the bound ligand when active urokinase was added, and preformed plasmin can also bind directly to the cells. Plasmin on the cell surface was also protected from its primary inhibitor, alpha 2-antiplasmin. These results indicate that the two cell lines possess specific binding sites for plasminogen and urokinase, and a family of widely distributed cellular receptors for these components may be considered. Endogenous or exogenous plasminogen activators can generate plasmin on cell surfaces, and such activation may provide a mechanism for arming cell surfaces with the broad proteolytic activity of this enzyme.


2013 ◽  
Vol 64 (2) ◽  
Author(s):  
Siti Nur Atiqah Md Othman ◽  
Norazah Basar ◽  
Siti Pauliena Mohd Bohari

P. macrocarpa is a well known Indonesian medicinal plant which is traditionally claimed to have anticancer properties. To date, there are numerous cytotoxic studies conducted on crude extracts of this plant. However, there are limited informations available regarding cytotoxic activity of the compounds isolated from this plant. Thus, this study investigated cytotoxic activity of two benzophenones derivatives identified as 2,6,4'-trihydroxy-4-methoxybenzophenone (1) and 6,4'-dihydroxy-4-methoxybenzophenone-2-O-β-D-glucopyranoside (2) isolated from the ethyl acetate extract. Cytotoxic activities of these compounds were performed against human cervical carcinoma cell line (HeLa) and mouse embryonic fibroblast cell line (3T3) using MTT assay. The result showed that benzophenone (1)  exhibited low cytotoxic effect against HeLa and 3T3 cell lines with IC50 values of 132 µg/ml and 158 µg/ml, repectively while benzophenone (2) was non toxic against HeLa and 3T3 cell lines are because the IC50 is more than 250 µg/ml. These findings may sheds light on the actual properties of this plant.


2020 ◽  
Vol 21 (22) ◽  
pp. 8820
Author(s):  
Hae-Jun Yang ◽  
Bong-Seok Song ◽  
Bo-Woong Sim ◽  
Yena Jung ◽  
Unbin Chae ◽  
...  

In recent decades, many studies on the treatment and prevention of pancreatic cancer have been conducted. However, pancreatic cancer remains incurable, with a high mortality rate. Although mouse models have been widely used for preclinical pancreatic cancer research, these models have many differences from humans. Therefore, large animals may be more useful for the investigation of pancreatic cancer. Pigs have recently emerged as a new model of pancreatic cancer due to their similarities to humans, but no pig pancreatic cancer cell lines have been established for use in drug screening or analysis of tumor biology. Here, we established and characterized an immortalized miniature pig pancreatic cell line derived from primary pancreatic cells and pancreatic cancer-like cells expressing K-rasG12D regulated by the human PTF1A promoter. Using this immortalized cell line, we analyzed the gene expression and phenotypes associated with cancer cell characteristics. Notably, we found that acinar-to-ductal transition was caused by K-rasG12D in the cell line constructed from acinar cells. This may constitute a good research model for the analysis of acinar-to-ductal metaplasia in human pancreatic cancer.


Blood ◽  
1993 ◽  
Vol 81 (5) ◽  
pp. 1184-1192 ◽  
Author(s):  
M Nishikawa ◽  
K Ozawa ◽  
A Tojo ◽  
T Yoshikubo ◽  
A Okano ◽  
...  

Abstract To investigate the functional change of stromal cells along with differentiation, we used a differentiation-inducible mouse embryo fibroblast cell line, C3H10T1/2 (10T1/2). Stably determined preadipocyte and myoblast cell lines were established after a brief exposure of 10T1/2 cells to 5-azacytidine. These cell lines terminally differentiated into adipocytes and myotubes, respectively, under appropriate conditions. The hematopoiesis-supporting ability of each 10T1/2-derived cell line was examined by coculture with FACS-sorted murine hematopoietic stem cells (Thy-1lo c-kit+ Lin-). The number of granulocyte-macrophage progenitors (CFU-GM) was slightly reduced after 7 days of culture with parent 10T1/2 fibroblasts, whereas a marked increase in CFU-GM number was observed when the cells were cultured on preadipocytes. Mature adipocytes and myogenically determined cell lines, on the other hand, did not support CFU-GM growth. Further, Northern analysis showed that the preadipocyte cell line acquired the ability to produce a significant amount of stem cell factor (SCF), interleukin-6 (IL-6), leukemia inhibitory factor, and macrophage colony- stimulating factor mRNAs in response to IL-1 or lipopolysaccharide stimulation. Terminal adipocytic differentiation resulted in reduced ability to express these cytokine mRNAs. Similarly, highest IL-6 activity was detected in the supernatant of preadipocyte culture, whereas adipocytes did not secrete IL-6 even after IL-1 stimulation. Interestingly, hematopoiesis-nonsupporting myoblasts and myotubes also expressed abundant SCF mRNA, suggesting that SCF, per se, may not be sufficient for stem cell growth and survival. The 10T1/2-derived cell lines could provide a valuable tool to aid in the analysis of stromal cell development and the search for novel stromal factors.


2020 ◽  
Vol 25 (01) ◽  
pp. 10-18
Author(s):  
Fatma Yurt ◽  
Ece Tugba Saka ◽  
Zekeriya Biyiklioglu ◽  
Ayça Tunçel ◽  
Derya Ozel ◽  
...  

In this study, two SiPcs have been selected and the photodynamic therapy potentials were evaluated of the Pcs. Synthesis of Axially 2-decyn-1-oxy disubstituted Es-SiPc-2 was newly synthesized by the reaction of SiPcCl2 with 2-decyn-1-ol in the presence of NaH in toluene. Furthermore, their nuclear imaging potentials were evaluated in human colon adenocarcinoma (HT-29) and human lung fibroblast cell (WI-38) cell lines. The uptake results have indicated that Es-SiPc labeled with [Formula: see text]I radionuclide ([Formula: see text]I-Es-SiPc) was approximately 2-fold higher in the HT-29 cell line than the WI-38 cell line. In other words, the target/non-target tissue ratio is defined as two in the HT-29/WI-38 cell lines. Besides, the uptake values of [Formula: see text]I-Es-SiPc were found to be higher than [Formula: see text]I-Es-SiPc-2. [Formula: see text]I-Es-SiPc and [Formula: see text]I-Es-SiPc-2 are promising for imaging or treating colon adenocarcinoma. In vitrophotodynamic therapy (PDT) studies have shown that both compounds are suitable and can be used in this field. Also, Es-SiPc has been shown to have higher phototoxicity than Es-SiPc-2.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Chi-Li Chiu ◽  
Michelle A. Digman ◽  
Enrico Gratton

Extracellular matrix (ECM) remodeling is a critical step of many biological and pathological processes. However, most of the studies to date lack a quantitative method to measure ECM remodeling at a scale comparable to cell size. Here, we applied image spatial correlation to collagen second harmonic generation (SHG) images to quantitatively evaluate the degree of collagen remodeling by cells. We propose a simple statistical method based on spatial correlation functions to determine the size of high collagen density area around cells. We applied our method to measure collagen remodeling by two breast cancer cell lines (MDA-MB-231 and MCF-7), which display different degrees of invasiveness, and a fibroblast cell line (NIH/3T3). We found distinct collagen compaction levels of these three cell lines by applying the spatial correlation method, indicating different collagen remodeling ability. Furthermore, we quantitatively measured the effect of Latrunculin B and Marimastat on MDA-MB-231 cell line collagen remodeling ability and showed that significant collagen compaction level decreases with these treatments.


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