Expression and processing of human preprogastrin in murine medullary thyroid carcinoma cells

1991 ◽  
Vol 260 (5) ◽  
pp. G783-G788 ◽  
Author(s):  
D. F. Daugherty ◽  
C. J. Dickinson ◽  
T. Takeuchi ◽  
D. Bachwich ◽  
T. Yamada
Keyword(s):  
Cell Line ◽  
Peptide Hormone ◽  
Biologically Active ◽  
Molecular Forms ◽  
Posttranslational Processing ◽  
Packaging Cell Line ◽  
Viral Stock ◽  
Peptide Precursors ◽  
Cdna Construct ◽  
Human Gastrin

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.

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
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Secretory Granules ◽  
Fibroblast Cell ◽  
Peptide Hormone ◽  
Biologically Active ◽  
Cdna Clones ◽  
Posttranslational Processing ◽  
Pancreatic Cell ◽  
Carboxy Terminal

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)

scholarly journals Secondary Structure as a Conformational Determinant in Processing of Peptide Precursors at Dibasic Amino Acids

2003 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Noureddine Lazar ◽  
Noureddine Brakch ◽  
Maï Panchal ◽  
Paul Cohen ◽  
Mohamed Rholam
Keyword(s):  
Secondary Structure ◽  
Structural Data ◽  
Peptide Hormone ◽  
Biologically Active ◽  
Site Directed Mutagenesis ◽  
Peptide Cleavage ◽  
Kinetic And Thermodynamic Parameters ◽  
Peptide Precursors ◽  
Conformational Determinant

The aim of this work was to establish the functional role of selected secondary structure motifs of peptide hormone precursors in their selective recognition by the corresponding converting endoproteases. The strategy was based on the use of synthetic peptides either reproducing or mimicking the sequences of the cleavage regions of two distinct models; i.e. pro-ocytocin–neurophysin and prosomatostatin. Both prohormones were capable to release their biologically active sequences either by cleavage at a dibasic stretch or by proteolysis at a monobasic site.Both kinetic and thermodynamic parameters of peptide cleavage by various convertases were measured. They were examined in light of structural data on preferred conformations adopted by these substrates, which were obtained by a combination of spectroscopical techniques including CD, FT-IR and proton NMR. In the case of prosomatostatin, these approaches were in addition paralleled by site-directed mutagenesis experiments.The wealth of collected data point toward the conclusion thatβ-turns and/or loops, favored by sequences bearing basic residues, constitute a key feature in the specification of those peptide loci which are proteolytically processedin vivo. They will be discussed with respect of other processing mechanisms where these mechanisms were also shown.

A Pilot Screen of a Novel Peptide Hormone Library Identified Candidate GPR83 Ligands

2020 ◽  
Vol 25 (9) ◽  
pp. 1047-1063
Author(s):  
Nathan A. Sallee ◽  
Ernestine Lee ◽  
Atossa Leffert ◽  
Silvia Ramirez ◽  
Arthur D. Brace ◽  
...  
Keyword(s):  
Secretory Pathway ◽  
Cell Function ◽  
Active Form ◽  
Peptide Hormone ◽  
Biologically Active ◽  
Host Cells ◽  
Functional Screening ◽  
Posttranslational Processing ◽  
Regulated Secretory Pathway ◽  
G Protein Coupled

The identification of novel peptide hormones by functional screening is challenging because posttranslational processing is frequently required to generate biologically active hormones from inactive precursors. We developed an approach for functional screening of novel potential hormones by expressing them in endocrine host cells competent for posttranslational processing. Candidate preprohormones were selected by bioinformatics analysis, and stable endocrine host cell lines were engineered to express the preprohormones. The production of mature hormones was demonstrated by including the preprohormones insulin and glucagon, which require the regulated secretory pathway for production of the active forms. As proof of concept, we screened a set of G-protein-coupled receptors (GPCRs) and identified protein FAM237A as a specific activator of GPR83, a GPCR implicated in central nervous system and regulatory T-cell function. We identified the active form of FAM237A as a C-terminally cleaved, amidated 9 kDa secreted protein. The related protein FAM237B, which is 64% homologous to FAM237A, demonstrated similar posttranslational modification and activation of GPR83, albeit with reduced potency. These results demonstrate that our approach is capable of identifying and characterizing novel hormones that require processing for activity.

Ecological and physiological as well as biochemical properties of representatives of the Genus sedum L.

2014 ◽  
Vol 25 (3-4) ◽  
pp. 24-33
Author(s):  
O. I. Dzjuba ◽  
M. V. Yatsenko
Keyword(s):  
Nitric Oxide ◽  
Cell Line ◽  
Methanol Extract ◽  
Hepatoma Cell ◽  
Ethanol Extract ◽  
Biochemical Properties ◽  
Biologically Active ◽  
Hepatoma Cell Line ◽  
Dependent Manner ◽  
Dose Dependent

The article deals with the history of the study and the current state of research of physiological and biochemical properties of the plant genus Sedum that are useful for human and has been used in folk medicine for many years. It was noticed that antioxidant properties of extracts from plants S. sarmentosum, S. sempervivoides, S. takesimense were caused by the presence of phenolic compounds. Methanol extract of plants S. takesimense exhibited strong scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals as well as significant inhibitory effects on lipid peroxidation and low density lipoprotein (LDL) oxidation induced by a metal ion Cu2+. Various immunomodulatory activities of various fractions of plants extracts (S. dendroideum, S. kamtschaticum, S. sarmentosum, S. telephium) are observed. It was shown that the ethanol extract of S. sarmentosum and it’s fractions suppressed specific antibody and cellular responses to ovalbumin in mice. The methanol extract of plants S. sarmentosum reduced the levels of anti-inflammatory markers, such as volume of exudates, number of polymorphonuclear leukocytes, suppressed nitric oxide synthesis in activated macrophages via suppressed induction of inducible nitric oxide synthase (iNOS). Polysaccharides fractions from plants S. telephium inducing productions of tumor necrosis factor alpha (TNF-α), increasing the intensity of phagocytosis in vitro and in vivo. Methanol extract from the whole part of S. kamtschaticum strongly inhibit PGE2 production from lipopolysaccharide-induced RAW 264.7 cells, a mouse macrophage cell line via modulating activity in gene expression of the enzyme cyclooxygenase-2 (COX-2). The methanol extract of plants S. sarmentosum and the major kaempferol glycosides from S. dendroideum have antinociceptive activity. It was noticed that anti-adipogenic activity of extracts from plants S. kamtschaticum were caused by inhibition of peroxisome-proliferator-activated receptor γ (PPARγ) expression and it’s dependent target genes, such as genes encoding adipocyte protein 2 (аР2), lipoprotein lipase (LPL), adiponectin and CD36. Polysaccharides fractions from S. telephium cause inhibition of cell adhesion of human fibroblast (MRC5) to laminin and fibronectin via interfere with integrin-mediated cell behaviour and they contributed to the role of polysaccharides in cell-matrix interaction. The methanol extract of plants S. sarmentosum exhibited a significant inhibitory activity in the chick embryo chorioallantoic membrane angiogenesis in a dose-dependent manner. The crude alkaloid fraction of S. sarmentosum caused a dose-dependent inhibition of cell proliferation on murine hepatoma cell line BNL CL.2 and human hepatoma cell line HepG2 without necrosis or apoptosis. Alkaloids from plants S. sarmentosum may improve survival of hepatoma patients via the inhibition of excessive growth of tumor cells. Plant’s juices have antiviral activity (S. sarmentosum, S. spurium, S. stahlii). Crude ethanol extract S. praealtum have spermicidal activity of the in mice and a relevant inhibitory effect of aqueous extract on human spermatozoa motility as well as an anti-fertilizing activity in rats. Hepatoprotective triterpenes, e.g., δ-amyrone, 3-epi-δ-amyrin, δ-amyrin and sarmentolin were isolated from S. sarmentosum. 2- and 2,6-substituted piperidine alkaloids (e.g., norsedamine, allosedridine, sedamine, allosedamine) are observed in plants S. acre, which in the presence of data on the use of pyridine and piperidine derivatives for treating neurodegenerative diseases (e.g., Alzheimer's disease), points on the promising research in this area. Taking into account that biologically active compounds are accumulated in the aboveground vegetative organs of plants of Sedum, the prospects of further study of the use of Sedum for the purposes of biotechnology and in the pharmaceutical industry becomes apparent. This work extends the existing views regarding the use of plants Sedum.

scholarly journals Chemical compositions, antimicrobial effects, and cytotoxicity of Asia minor wormwood (Artemisia splendens Willd.) growing in Iran

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Fariba Heshmati Afshar ◽  
Masumeh Zadehkamand ◽  
Zahra Rezaei ◽  
Abbas Delazar ◽  
Vahideh Tarhriz ◽  
...  
Keyword(s):  
Cell Line ◽  
Proliferative Activity ◽  
Methanolic Extract ◽  
Biologically Active ◽  
Flavonoid Glycosides ◽  
Control Group ◽  
Chemical Compositions ◽  
Preparative Hplc ◽  
Cytotoxicity Activity ◽  
Methanolic Extracts

Abstract Background Artemisia splendens from the Asteraceae family is a new source of biologically active compounds. The current study investigated to evaluate antimicrobial and cytotoxicity activity of methanolic extracts and their fractions obtained from aerial parts by agar disk diffusion and MTT methods, respectively. The active fractions were subjected to preparative HPLC for isolating the pure compounds, which were structurally elucidated, by 1H and 13C NMR. Results The results showed that the methanolic extract and its 60% SPE fraction have the anti-proliferative activity on A549 cell line in comparison with the control group. Meanwhile, the methanolic extract and its 40% SPE fraction can inhibit the growth of Gram-positive strains as anti-microbial activity. The 60% SPE fraction also illustrated anti-proliferative activity on the HT-29 cell line compared to the control group. Chromatographic separations via preparative HPLC yielded 5 flavonoids and three flavonoid glycosides. Conclusion Based on the results it can be concluded that A. splendens as a potential source of cytotoxic and antimicrobial compounds can be used in pharmaceutics.

scholarly journals Natural Antioxidants in Anemia Treatment

2021 ◽  
Vol 22 (4) ◽  
pp. 1883
Author(s):  
Coralia Cotoraci ◽  
Alina Ciceu ◽  
Alciona Sasu ◽  
Anca Hermenean
Keyword(s):  
Plant Extracts ◽  
Iron Homeostasis ◽  
Therapeutic Potential ◽  
Public Health Problem ◽  
Natural Antioxidants ◽  
Peptide Hormone ◽  
Biologically Active ◽  
Major Public Health Problem ◽  
Stomach Pain

Anemia, characterized by a decrease of the hemoglobin level in the blood and a reduction in carrying capacity of oxygen, is a major public health problem which affects people of all ages. The methods used to treat anemia are blood transfusion and oral administration of iron-based supplements, but these treatments are associated with a number of side effects, such as nausea, vomiting, constipation, and stomach pain, which limit its long-term use. In addition, oral iron supplements are poorly absorbed in the intestinal tract, due to overexpression of hepcidin, a peptide hormone that plays a central role in iron homeostasis. In this review, we conducted an analysis of the literature on biologically active compounds and plant extracts used in the treatment of various types of anemia. The purpose of this review is to provide up-to-date information on the use of these compounds and plant extracts, in order to explore their therapeutic potential. The advantage of using them is that they are available from natural resources and can be used as main, alternative, or adjuvant therapies in many diseases, such as various types of anemia.

CHEMICAL AND BIOLOGICAL ANALYSIS OF THE BIOCTIVE FRACTIONS OF THE LEAVES OF SCAEVOLA TACCADA (GAERTN.) ROXB

2021 ◽  
pp. 35-41
Author(s):  
EMAN M. ABDEL GHANI ◽  
ABEER M. EL SAYED ◽  
SOAD H. TADROS ◽  
FATHY M. SOLIMAN
Keyword(s):  
Ethyl Acetate ◽  
Petroleum Ether ◽  
Cell Line ◽  
Carcinoma Cell ◽  
Antioxidant Effect ◽  
Carcinoma Cell Line ◽  
Biologically Active ◽  
Breast Carcinoma Cell Line ◽  
Gram Positive ◽  
Butanol Fraction

Objective: Scaevola taccada. (Gaertn.) Roxb. is widely dispersed all along the coasts of Africa. It is used in folk medicine for diversity of ailments. This study aims to investigate the major phytoconstituents and biological activities of the leaves of S. taccada (Gaertn.) Roxb. Methods: In vitro biological examination viz. antimicrobial, cytotoxic and antioxidant activities of the ethanol extract of the leaves (EE) and its fractions; (petroleum ether (PE), methylene chloride (MC), ethyl acetate (EA) and n-butanol(BuOH)) were carried out. Estimation of the phytochemicals of biologically active fractions was done. Results: n-butanol fraction displayed remarkable antimycobacterium activity. Petroleum ether as well as n-butanol fractions evidenced a cytotoxic effect on breast carcinoma cell line (MCF7) and colon carcinoma cell line (HCT) with IC50 11.7 and 15.04 µg/ml respectively. Moreover, ethyl acetate fraction exhibits an antioxidant effect with EC50 476.7±0.57 µg/ml. n-tetradecane 1, α-amyrin palmitate 2, α-amyrin acetate 3, α-amyrin 4, stigmasterol 5, luteolin-7-O-β-glucoside 6, rutin 7 and alidyjosioside 8 were identified in S. taccada (Gaertn.) Roxb. leaves. Conclusion: Petroleum ether fraction is a cytotoxic candidate, especially against (MCF-7). It exhibited a moderate antifungal and antibacterial against certain Gram-positive bacteria. Ethyl acetate showed an antioxidant effect along with moderate antifungal activity. n-butanol fraction exerted potential antimycobacterial, significant cytotoxic activity against (HCT), good antifungal and antibacterial against Gram-positive and Gram-negative bacteria. Stigmasterol, luteolin-7-O-β-glucoside, rutin and alidyjosioside were isolated for the first time from S. taccada (Gaertn.) Roxb. Leaves.

Efficient transduction and selection of human T-lymphocytes with bicistronic Thy1/HSV1-TK retroviral vector produced by a human packaging cell line

2004 ◽  
Vol 6 (4) ◽  
pp. 374-386 ◽  
Author(s):  
François M. Lemoine ◽  
Mariana Mesel-Lemoine ◽  
Mustapha Cherai ◽  
Géraldine Gallot ◽  
Henri Vié ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cell Line ◽  
Retroviral Vector ◽  
Packaging Cell Line ◽  
Packaging Cell ◽  
Human T Lymphocytes ◽  
Selection Of

Studies on the use of cultured cells in a bioassay for parathyroid hormone

1994 ◽  
Vol 143 (2) ◽  
pp. 261-268
Author(s):  
A E Armston ◽  
P J Wood
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Cell Line ◽  
Cultured Cells ◽  
Biologically Active ◽  
Kidney Cell Line ◽  
Opossum Kidney ◽  
Pre Treatment ◽  
Set Up ◽  
Insufficient Sensitivity

Abstract Measurement of parathyroid hormone (PTH) is important for diagnosing hyper- and hypoparathyroidism. The move to two-site immunometric assays that detect the whole molecule has improved the discrimination of these conditions but these assays may be too restrictive because some PTH fragments that are biologically active may not be detected. In addition, PTH-like peptide of malignancy, an important cause of malignancy-associated hypercalcaemia, is not detected by the two-site assays. Experiments were performed to set up a simple, robust and inexpensive bioassay for PTH, exploiting a kidney cell line and using cyclic AMP or an eluted stain assay as the end point. Of the 12 cell lines tested, an opossum kidney (WOK) cell line showed the most promise. Despite optimization of the procedure to include pre-treatment with dexamethasone, insulin and PTH, followed by incubation in the presence of 5′ -guanylimidodiphosphate, isobutyl-1-methylxanthine and forskolin, the WOK cells showed insufficient sensitivity for use in a cultured cell bioassay for PTH in human serum. In addition, the cells were less sensitive to PTH-like peptide precluding their use for an assay for this molecule. Journal of Endocrinology (1994) 143, 261–268

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