Increased glycated calmodulin in the submandibular salivary glands of streptozotocin‐induced diabetic rats

Abstract

Non-enzymatic glycosylation, a post translational protein modification may be implicated in the diabetes complications. Calmodulin is an important calcium binding protein that complexed with Ca(2+) may be implicated in salivary gland secretory process. Glycated calmodulin has shown to be less effective in binding calcium. The aim of this study was to determine whether the concentration of glycated-calmodulin may be elevated in the submandibular salivary glands of streptozotocin-induced diabetic rats. Diabetes was induced by an intraperitoneal injection of spreptozotocin, and hyperglycemia was confirmed 72 h after injection using a glucosimeter. Thirty days after the induction of diabetes, submandibular salivary glands were used for the analysis of glycated and non-glycated calmodulin, using a glycogel B columns for separation. Glycated and non-glycated calmodulin were assayed by an enzymatic method and by ELISA. The overall concentration of CaM (non-glycated + glycated) in induced diabetic rats was significantly lower than in controls (p < 0.05). The concentration of non-glycated CaM in controls was significantly higher than in experimental group (p < 0.05), while the concentration of glycated calmodulin between these groups was statistically similar (p > 0.05).

Diabetes affects statherin expression in human labial glands

“…By a general point of view, the vascular defects that often accompany the diabetic condition could result in scarce tissue oxygenation, leading to decreased metabolism and protein synthesis. Moreover, multiple effects of hyperglycemia on protein synthesis have been ascertained, such as post‐transcriptional modifications, which create abnormal protein glycosylation (Nicolau et al , 2009), intracellular storage and release, and altered cell response to endoplasmic reticulum stress (Yoshida, 2007).…”

Identification of Potential Glycoprotein Biomarkers in Estrogen Receptor Positive (ER+) and Negative (ER-) Human Breast Cancer Tissues by LC-LTQ/FT-ICR Mass Spectrometry

“…Further non-enzymatic reactions may change the N-glycosylamine to an advanced glycation end product. Glycation affects the function of CaM 88, for example, glycated-CaM appears to be less prone for binding calcium 89 and, therefore, CaM may be less capable to activate its enzyme targets. The N-substituted glucosamine at the lysine residues of glycated-CaM, after further reactions, may resemble N-acetyl glucosamine and therefore may attach to WGA resin.…”

Antioxidant enzymatic defense in salivary glands of streptozotocin‐induced diabetic rats: a temporal study

“…Numerous studies have reported the effects of experimental diabetes induced either by STZ or aloxan on the structure and functions of salivary glands of animals,7, 28, 29 including the antioxidant parameters status in various tissues 4, 7, 28. Studies based on aloxan‐diabetes rats showed significant decrease in DNA, RNA and amylase content in rat PA glands, increase in the peroxidase activity,7, 8, 30 increase of SGTL1 (responsible for the reabsorption of water in the duct cells) protein expression in ductal cells in diabetic rats,31 increase in the extracellular matrix proteins in PA,18 decrease in Ca‐ATPase, unbalance of Ca in the salivary gland32 and finally, an increase in the glycation of calmodulin 33. Despite all studies, the mechanism of the damages caused by diabetes is still not clear.…”