The effects ex vivo and in vitro of insulin and C-peptide on Na/K adenosine triphosphatase activity in red blood cell membranes of type 1 diabetic patients

Metabolism ◽  
2000 ◽  
Vol 49 (7) ◽  
pp. 868-872 ◽  
Author(s):  
A. Djemli-Shipkolye ◽  
P. Gallice ◽  
T. Coste ◽  
M.F. Jannot ◽  
M. Tsimaratos ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Adenosine Triphosphatase ◽  
Ex Vivo ◽  
Diabetic Patients ◽  
C Peptide ◽  
Red Blood Cell Membranes ◽  
Type 1 Diabetic Patients

scholarly journals Low frequency of GITR+ T cells in ex vivo and in vitro expanded Treg cells from type 1 diabetic patients

2013 ◽  
Vol 25 (10) ◽  
pp. 563-574 ◽  
Author(s):  
Cristina Xufré ◽  
Manuela Costa ◽  
Carme Roura-Mir ◽  
Eva Codina-Busqueta ◽  
Lorena Usero ◽  
...  
Keyword(s):  
T Cells ◽  
Ex Vivo ◽  
Low Frequency ◽  
Treg Cells ◽  
Diabetic Patients ◽  
Type 1 Diabetic Patients

scholarly journals C-peptide,Na+,K+-ATPase, and Diabetes

2004 ◽  
Vol 5 (1) ◽  
pp. 37-50 ◽  
Author(s):  
P. Vague ◽  
T. C. Coste ◽  
M. F. Jannot ◽  
D. Raccah ◽  
M. Tsimaratos
Keyword(s):  
Blood Cell ◽  
Atpase Activity ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Diabetic Complications ◽  
Blood Cells ◽  
Diabetic Patients ◽  
C Peptide

Na+,K+-ATPase is an ubiquitous membrane enzyme that allows the extrusion of three sodium ions from the cell and two potassium ions from the extracellular fluid. Its activity is decreased in many tissues of streptozotocin-induced diabetic animals. This impairment could be at least partly responsible for the development of diabetic complications.Na+,K+-ATPase activity is decreased in the red blood cell membranes of type 1 diabetic individuals, irrespective of the degree of diabetic control. It is less impaired or even normal in those of type 2 diabetic patients. The authors have shown that in the red blood cells of type 2 diabetic patients,Na+,K+-ATPase activity was strongly related to blood C-peptide levels in non–insulin-treated patients (in whom C-peptide concentration reflects that of insulin) as well as in insulin-treated patients. Furthermore, a gene-environment relationship has been observed. The alpha-1 isoform of the enzyme predominant in red blood cells and nerve tissue is encoded by theATP1A1gene.Apolymorphism in the intron 1 of this gene is associated with lower enzyme activity in patients with C-peptide deficiency either with type 1 or type 2 diabetes, but not in normal individuals. There are several lines of evidence for a low C-peptide level being responsible for lowNa+,K+-ATPase activity in the red blood cells. Short-term C-peptide infusion to type 1 diabetic patients restores normalNa+,K+-ATPase activity. Islet transplantation, which restores endogenous C-peptide secretion, enhancesNa+,K+-ATPase activity proportionally to the rise in C-peptide. This C-peptide effect is not indirect. In fact, incubation of diabetic red blood cells with C-peptide at physiological concentration leads to an increase ofNa+,K+-ATPase activity. In isolated proximal tubules of rats or in the medullary thick ascending limb of the kidney, C-peptide stimulates in a dose-dependent mannerNa+,K+-ATPase activity. This impairment inNa+,K+-ATPase activity, mainly secondary to the lack of C-peptide, plays probably a role in the development of diabetic complications. Arguments have been developed showing that the diabetesinduced decrease inNa+,K+-ATPase activity compromises microvascular blood flow by two mechanisms: by affecting microvascular regulation and by decreasing red blood cell deformability, which leads to an increase in blood viscosity. C-peptide infusion restores red blood cell deformability and microvascular blood flow concomitantly withNa+,K+-ATPase activity. The defect in ATPase is strongly related to diabetic neuropathy. Patients with neuropathy have lower ATPase activity than those without. The diabetes-induced impairment inNa+,K+-ATPase activity is identical in red blood cells and neural tissue. Red blood cell ATPase activity is related to nerve conduction velocity in the peroneal and the tibial nerve of diabetic patients. C-peptide infusion to diabetic rats increases endoneural ATPase activity in rat. Because the defect inNa+,K+-ATPase activity is also probably involved in the development of diabetic nephropathy and cardiomyopathy, physiological C-peptide infusion could be beneficial for the prevention of diabetic complications.

scholarly journals The Exon 46-Encoded Sequence Is Essential for Stability of Human Erythroid α-Spectrin and Heterodimer Formation

Blood ◽  
1997 ◽  
Vol 90 (10) ◽  
pp. 4188-4196 ◽  
Author(s):  
Rick Wilmotte ◽  
Sandra L. Harper ◽  
Jeanine A. Ursitti ◽  
Joëlle Maréchal ◽  
Jean Delaunay ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Membranes ◽  
Peptide Sequence ◽  
Α Subunit ◽  
Recombinant Peptide ◽  
Alternative Mrna Splicing ◽  
Recombinant Peptides ◽  
Red Blood Cell Membranes

Abstract Human erythroid α-spectrin alleles responsible for hereditary elliptocytosis (αHE alleles) undergo increased incorporation into red blood cell membranes when the polymorphism αLELY (LELY: Low Expression LYon) occurs in trans. The αLELY polymorphism is characterized by a mutation in exon 40 at codon 1857 (CTA → GTA, Leu → Val) and the partial (50%) skipping of exon 46, which encodes residues 2177-2182 (Wilmotte et al, J Clin Invest 91:2091, 1993). Both of these peptide sequence alterations are located within the region of the α-chain involved in initiating heterodimer assembly, and either or both mutations could potentially contribute to decreased incorporation of α-chains from the αLELY allele in heterozygotes into red blood cell membranes. These possibilities were evaluated by testing the protease resistance and in vitro binding properties of normal and mutant recombinant 4-motif α subunit peptides containing the dimer initiation region. The two forms of α spectrin produced by alternative mRNA splicing of the αLELY allele were represented by α18-211857, a peptide with the codon 1857 mutation and retaining the exon 46 encoded sequence, and α18-211857-Δ46, a peptide carrying both the 1857 codon mutation and the exon 46 deletion. The properties of these two recombinant peptides were compared with α18-21, a peptide with the normal sequence at codon 1857 and retaining the exon 46 encoded sequence. The codon 1857 mutation does not adversely affect dimer formation, but it is responsible for the increased trypsin cleavage between the αIV and αV domains that was the characteristic feature initially used to identify the αLELY (SpαV/41) polymorphism (Alloisio et al, J Clin Invest 87:2169, 1991). Deletion of the six amino acids encoded by exon 46 perturbs folding of the α21 motif, because this region of the α18-211857-Δ46 peptide is rapidly degraded and this recombinant peptide is unusually prone to self-aggregation. Exon 46 deletion reduces, but does not eliminate, dimerization. Comparison of mild trypsin proteolytic products from an αLELY homozygote and the two αLELY recombinant peptides strongly suggests that little, if any, of the 50% of the α chains from the αLELY allele that contain the exon 46 deletion are incorporated into the mature erythroid membrane. Based on the in vitro analysis of recombinant αLELY peptides, the inability of detectable amounts of exon 46− α chains to assemble into the mature membrane skeleton in vivo is probably due to a combination of decreased dimer binding affinity and increased proteolytic degradation of these mutant chains.

Protein disregulation in red blood cell membranes of type 2 diabetic patients

2003 ◽  
Vol 309 (1) ◽  
pp. 196-200 ◽  
Author(s):  
Ming Jiang ◽  
Linzhi Jia ◽  
Weihua Jiang ◽  
Xiaojian Hu ◽  
Hanqing Zhou ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Membranes ◽  
Diabetic Patients ◽  
Type 2 Diabetic Patients ◽  
Red Blood Cell Membranes ◽  
Type 2 Diabetic

Activation of human aortic endothelial cells by LDL from Type 1 diabetic patients: an in vitro study

2002 ◽  
Vol 165 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Rosa A Rabini ◽  
Arianna Vignini ◽  
Eleonora Salvolini ◽  
Roberto Staffolani ◽  
Daniela Martarelli ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
In Vitro Study ◽  
Vitro Study ◽  
Diabetic Patients ◽  
Aortic Endothelial Cells ◽  
Type 1 Diabetic Patients ◽  
Human Aortic Endothelial Cells ◽  
Aortic Endothelial

Low-density lipoproteins from type 1 diabetic patients induce in vitro endothelial dysfunction

1999 ◽  
Vol 144 ◽  
pp. 57
Author(s):  
R.A. Rabini ◽  
R. Staffolani ◽  
E. Salvolini ◽  
D. Martarelli ◽  
A. Vignini
Keyword(s):  
Endothelial Dysfunction ◽  
Low Density Lipoproteins ◽  
Diabetic Patients ◽  
Low Density ◽  
Type 1 Diabetic Patients
Sign in / Sign up

Export Citation Format

Share Document