scholarly journals Isolation of modified ubiquitin as a neutrophil chemotaxis inhibitor from uremic patients.

1998 ◽  
Vol 9 (3) ◽  
pp. 451-456 ◽  
Author(s):  
G Cohen ◽  
M Rudnicki ◽  
W H Hörl
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Inhibitory Effect ◽  
Uremic Toxins ◽  
Vitro Assay ◽  
Amino Terminal ◽  
Increased Risk ◽  
Western Blot Experiment ◽  
Uremic Patients ◽  
Amino Terminal Sequence

Uremic toxins are factors that accumulate in the serum and peritoneal cavity of uremic patients. They are responsible for a variety of functional disturbances and also contribute to the increased risk of infection by interfering with essential functions of the unspecific immune response. From the peritoneal effluent of peritoneal dialysis (PD) patients, a peptide was isolated by applying three different chromatographic methods. This peptide inhibits the chemotactic movement of polymorphonuclear leukocytes (PMNL) in an in vitro assay in a concentration-dependent, nonreversible manner, and therefore belongs to the group of uremic toxins. Amino acid sequencing showed that the isolated peptide has the same amino terminal sequence as ubiquitin. The peptide also reacted with anti-ubiquitin antibodies in a Western blot experiment, but had a more acidic isoelectric point than ubiquitin. By using affinity chromatography, anti-ubiquitin antibody binding fractions were isolated from all PD and hemodialysis (HD) patients investigated. These fractions contained the same acidic band and also significantly inhibited PMNL chemotaxis. Ubiquitin per se had no effect on PMNL chemotaxis. Therefore, it is concluded that from PD and HD patients a modified form of ubiquitin was isolated, and this modification was responsible for its inhibitory effect.

scholarly journals Uremic Toxins and Their Relation with Oxidative Stress Induced in Patients with CKD

2021 ◽  
Vol 22 (12) ◽  
pp. 6196
Author(s):  
Anna Pieniazek ◽  
Joanna Bernasinska-Slomczewska ◽  
Lukasz Gwozdzinski
Keyword(s):  
Oxidative Stress ◽  
Uremic Toxins ◽  
Water Medium ◽  
Induce Insulin Resistance ◽  
Risk Of Mortality ◽  
Increased Risk ◽  
Stage Renal Disease ◽  
End Stage

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.

scholarly journals The CAD risk locus 9p21 increases the risk of vascular calcification in an iPSC-derived VSMC model

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anja Trillhaase ◽  
Beatrice Schmidt ◽  
Marlon Märtens ◽  
Undine Haferkamp ◽  
Jeanette Erdmann ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Vascular Calcification ◽  
Alizarin Red ◽  
Vitro Assay ◽  
Human Ipscs ◽  
Increased Risk ◽  
Risk Locus ◽  
9P21 Locus ◽  
Cad Risk

Abstract Background Coronary artery disease (CAD) is the leading cause of death worldwide. Chromosome locus 9p21 was the first to be associated with increased risk of CAD and coronary artery calcification (CAC). Vascular calcification increases the risk for CAD. Vascular smooth muscle cells (VSMCs) are one of the major cell types involved in the development of vascular calcification. Methods So far, mainly animal models or primary SMCs have been used to model human vascular calcification. In this study, a human in vitro assay using iPSC-derived VSMCs was developed to examine vascular calcification. Human iPSCs were derived from a healthy non-risk (NR) and risk (R) donor carrying SNPs in the 9p21 locus. Additionally, 9p21 locus knockouts of each donor iPSC line (NR and R) were used. Following differentiation, the iPSC-derived VSMCs were characterized based on cell type, proliferation, and migration rate, along with calcium phosphate (CaP) deposits. CaP deposits were confirmed using Calcein and Alizarin Red S staining and then quantified. Results The data demonstrated significantly more proliferation, migration, and CaP deposition in VSMCs derived from the R and both KO iPSC lines than in those derived from the NR line. Molecular analyses confirmed upregulation of calcification markers. These results are consistent with recent data demonstrating increased calcification when the 9p21 murine ortholog is knocked-out. Conclusion Therefore, in conclusion, genetic variation or deletion of the CAD risk locus leads to an increased risk of vascular calcification. This in vitro human iPSC model of calcification could be used to develop new drug screening strategies to combat CAC.

scholarly journals Effects of Parathyroid Hormone on Immune Function

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Abdallah Sassine Geara ◽  
Mario R. Castellanos ◽  
Claude Bassil ◽  
Georgia Schuller-Levis ◽  
Eunkue Park ◽  
...  
Keyword(s):  
T Cells ◽  
Parathyroid Hormone ◽  
Immune Function ◽  
Clinical Significance ◽  
Uremic Toxins ◽  
Immunomodulatory Effects ◽  
Uremic Patients

Parathyroid hormone (PTH) function as immunologic mediator has become interesting with the recent usage of PTH analogue (teriparatide) in the management of osteoporosis. Since the early 1980s, PTH receptors were found on most immunologic cells (neutrophils, B and T cells). The in vitro evaluations for a possible role of PTH as immunomodulator have shown inconsistent results mainly due to methodological heterogeneity of these studies: it used different PTH formulations (rat, bovine, and human), at different dosages and different incubating periods. In some of these studies, the lymphocytes were collected from uremic patients or animals, which renders the interpretation of the results problematic due to the effect of uremic toxins. Parathyroidectomy has been found to reverse the immunologic defect in patients with high PTH levels. Nonetheless, the clinical significance of these findings is unclear. Further studies are needed to define if PTH does have immunomodulatory effects.

scholarly journals The neural chaperone proSAAS blocks α-synuclein fibrillation and neurotoxicity

2016 ◽  
Vol 113 (32) ◽  
pp. E4708-E4715 ◽  
Author(s):  
Timothy S. Jarvela ◽  
Hoa A. Lam ◽  
Michael Helwig ◽  
Nikolai Lorenzen ◽  
Daniel E. Otzen ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Disease ◽  
Primary Cultures ◽  
Lewy Bodies ◽  
Vitro Assay ◽  
Amino Terminal ◽  
Neuroprotective Function ◽  
Fluid Biomarker

Emerging evidence strongly suggests that chaperone proteins are cytoprotective in neurodegenerative proteinopathies involving protein aggregation; for example, in the accumulation of aggregated α-synuclein into the Lewy bodies present in Parkinson’s disease. Of the various chaperones known to be associated with neurodegenerative disease, the small secretory chaperone known as proSAAS (named after four residues in the amino terminal region) has many attractive properties. We show here that proSAAS, widely expressed in neurons throughout the brain, is associated with aggregated synuclein deposits in the substantia nigra of patients with Parkinson’s disease. Recombinant proSAAS potently inhibits the fibrillation of α-synuclein in an in vitro assay; residues 158–180, containing a largely conserved element, are critical to this bioactivity. ProSAAS also exhibits a neuroprotective function; proSAAS-encoding lentivirus blocks α-synuclein-induced cytotoxicity in primary cultures of nigral dopaminergic neurons, and recombinant proSAAS blocks α-synuclein–induced cytotoxicity in SH-SY5Y cells. Four independent proteomics studies have previously identified proSAAS as a potential cerebrospinal fluid biomarker in various neurodegenerative diseases. Coupled with prior work showing that proSAAS blocks β-amyloid aggregation into fibrils, this study supports the idea that neuronal proSAAS plays an important role in proteostatic processes. ProSAAS thus represents a possible therapeutic target in neurodegenerative disease.

scholarly journals Phenolic Acids from Lycium barbarum Leaves: In Vitro and In Silico Studies of the Inhibitory Activity against Porcine Pancreatic α-Amylase

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1388
Author(s):  
Luna Pollini ◽  
Alessandra Riccio ◽  
Cristina Juan ◽  
Carmela Tringaniello ◽  
Federica Ianni ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Inhibitory Activity ◽  
Leaf Extract ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Lycium Barbarum ◽  
Plant Materials ◽  
Vitro Assay ◽  
In Silico Studies

Nowadays, bioactive compounds from vegetable food and waste are of great interest for their inhibitory potential against digestive enzymes. In the present study, the inhibitory activity of methanolic extract from Lycium barbarum leaves on porcine pancreas α-amylase has been studied. The α-amylase inhibitory activity of the constituent phenolic acids was also investigated. The leaves were extracted by ultrasound-assisted method, one of the most efficient techniques for bioactive extraction from plant materials, and then the phenolic acids were identified by Accurate-Mass Quadrupole Time-of-Flight (Q-TOF) Liquid Chromatography/Mass Spectrometry (LC/MS). Chlorogenic and salicylic acids were the most abundant phenolic acids in L. barbarum leaf extract. The inhibitory effect against α-amylase, determined for individual compounds by in vitro assay, was higher for chlorogenic, salicylic, and caffeic acids. L. barbarum leaf extract showed an appreciable α-amylase inhibitory effect in a concentration-dependent manner. Docking studies of the considered phenolic acids into the active site of α-amylase suggested a conserved binding mode that is mainly stabilized through H-bonds and π-π stacking interactions.

scholarly journals Soluble kit receptor in human serum

Blood ◽  
1995 ◽  
Vol 85 (1) ◽  
pp. 66-73 ◽  
Author(s):  
J Wypych ◽  
LG Bennett ◽  
MG Schwartz ◽  
CL Clogston ◽  
HS Lu ◽  
...  
Keyword(s):  
Human Serum ◽  
Partial Purification ◽  
Enzyme Linked Immunosorbent Assay ◽  
Glycosylation Pattern ◽  
Vitro Assay ◽  
Amino Terminal ◽  
Kit Receptor ◽  
Normal Human

c-kit encodes the transmembrane receptor tyrosine kinase (Kit) for the recently described ligand stem cell factor (SCF). We have developed an enzyme-linked immunosorbent assay for measuring soluble human Kit and we have used the assay to show high levels of soluble Kit in human serum. The distribution of soluble Kit levels was investigated among 112 normal human serum donors. The mean serum level (+/- SD) was found to be 324 +/- 105 ng/mL with the values falling between 163 ng/mL and 788 ng/mL. No correlation between soluble Kit levels and the sexes or ages of the donors was found. Partial purification using immunoaffinity chromatography allowed us to characterize the soluble Kit from pooled human serum. Antibodies generated to a 497-amino acid recombinant human soluble Kit corresponding to the N-terminal extracellular domain of the receptor recognized the serum-derived soluble Kit by immunoblotting. We found that the serum-derived soluble Kit is glycosylated, with mostly N- linked but also O-linked carbohydrate, and with terminal sialic acid residues. When compared with the recombinant human soluble Kit, the serum-derived material was similar both in size and glycosylation pattern. CNBr cleavage of the isolated serum-derived material followed by amino terminal sequencing confirmed the presence of five peptides expected for the extracellular portion of the Kit molecule. The immunoaffinity purified serum-derived soluble Kit inhibited binding of [125I]SCF to membrane-bound receptor in an in vitro assay. These results indicate that soluble Kit could modulate the activity and functions of SCF in vivo.

Lactobacillus inhibitor production against Escherichia coli and coaggregation ability with uropathogens

1988 ◽  
Vol 34 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Gregor Reid ◽  
Jacqueline A. McGroarty ◽  
Rosanne Angotti ◽  
Roger L. Cook
Keyword(s):  
Escherichia Coli ◽  
Defense Mechanism ◽  
Inhibitory Effect ◽  
Second Phase ◽  
Vitro Assay ◽  
E Coli ◽  
Host Defense Mechanism ◽  
Important Host ◽  
Two Phases

Previous investigations have shown that certain strains of lactobacilli can competitively exclude uropathogens from attaching to uroepithelial cells and from causing urinary tract infection in animals. The finding of an inhibitory effect produced by Lactobacillus casei ssp. rhamnosus GR-1 against the growth of uropathogens was investigated further using two Escherichia coli indicator strains Hu 734 and ATCC 25922. There were two phases to the inhibitor studies. The first one using an agar sandwich technique showed that the inhibitor activity was heat stable and inhibitory to the E. coli. The second phase showed that MRS broth provided optimum lactobacilli growth and inhibitor production. In addition, the inhibition was present under conditions buffering for acid and pH. The data indicated that the inhibitory effect was not due to bacteriophages or hydrogen peroxide. Strain GR-1 was found to coaggregate with E. coli ATCC 25922 in urine, a phenomenon that has not previously been reported for urogenital bacteria. An in vitro assay system was developed to study the coaggregation of various lactobacilli and uropathogens. The results demonstrated that highest coaggregation scores occurred after 4 h incubation at 37 °C with lactobacilli and two type-1 fimbriated E. coli strains. Of the nine lactobacilli strains tested, each was found to coaggregate with 2 or more of the 13 uropathogens. The dominance of inhibitor-producing lactobacilli on the urogenital epithelium and the ability of these organisms to interact closely with uropathogens would constitute an important host defense mechanism against infection.

Farnesyltransferase inhibitor tipifarnib (R115777) preferentially inhibits in vitro autonomous erythropoiesis of polycythemia vera patient cells

Blood ◽  
2005 ◽  
Vol 105 (9) ◽  
pp. 3743-3745 ◽  
Author(s):  
Jérôme Larghero ◽  
Nathalie Gervais ◽  
Bruno Cassinat ◽  
Jean-Didier Rain ◽  
Marie-Hélène Schlageter ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Cell Mass ◽  
Inhibitory Effect ◽  
Chemotherapeutic Agents ◽  
Ras Signaling ◽  
Farnesyl Transferase ◽  
Increased Risk ◽  
Clinical Interest

AbstractPolycythemia vera (PV) is an acquired myeloproliferative disorder with primary expansion of the red cell mass leading to an increased risk of thrombosis and less frequently to myelofibrosis and secondary acute leukemia. Standard therapies include cytoreduction with either phlebotomy or chemotherapeutic agents and antithrombotic drugs. Because long-term exposure to cytotoxic chemotherapy may increase the risk of acute transformation, new therapeutic options are needed. Tipifarnib is a nonpeptidomimetic inhibitor of farnesyl transferase that was developed as a potential inhibitor of RAS signaling. In the present study we report that tipifarnib used at pharmacologically achievable concentrations strongly inhibits the erythroid burst-forming unit (BFU-E) autonomous growth that characterizes patients with PV. Moreover, at low tipifarnib concentrations (0.15 μM), the inhibitory effect was preferentially observed in PV BFU-E progenitors and not in normal BFU-E progenitors and was not rescued by erythropoietin (EPO). Thus tipifarnib may specifically target PV stem cells and may be of clinical interest in the treatment of patients with PV.

Glucocorticoid receptor and inhibition of 3-O-methyl-D-glucose uptake by glucocorticoids in peripheral blood leukocytes from normal humans: correlation between receptor level and hormone effect in vitro

1992 ◽  
Vol 126 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Hirotoshi Tanaka ◽  
Hideto Akama ◽  
Yoichi Ichikawa ◽  
Mitsuo Homma ◽  
Isao Makino
Keyword(s):  
Glucocorticoid Receptor ◽  
Glucose Uptake ◽  
Peripheral Blood ◽  
Polymorphonuclear Leukocytes ◽  
Inhibitory Effect ◽  
Mononuclear Leukocytes ◽  
Peripheral Blood Leukocytes ◽  
Blood Leukocytes ◽  
The Individual

We have measured the glucocorticoid receptor concentration in mononuclear and polymorphonuclear leukocytes, both of which were isolated from peripheral blood from ten healthy male volunteers. In parallel, the inhibitory effect of dexamethasone on 3-O-methyl-D-glucose uptake was assayed in the corresponding mononuclear leukocytes. The glucocorticoid receptor levels in mononuclear leukocytes correlated with those in polymorphonuclear leukocytes, and there was a linear relationship between the cellular glucocorticoid receptor levels and glucocorticoid-mediated inhibition of the uptake of 3-O-methyl-D-glucose in mononuclear leukocytes. When mononuclear leukocytes were incubated in the presence of 8-bromo-cAMP, cellular glucocorticoid receptor levels increased and a more pronounced inhibitory effect of dexamethasone was observed on the transport of 3-O-methyl-D-glucose. We conclude that the cellular glucocorticoid receptor levels in peripheral blood leukocytes reflect in vitro responsiveness to glucocorticoids in mononuclear leukocytes from healthy males, and that the individual responsiveness may alter upon changes in the cellular levels of glucocorticoid receptor.

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