@article { ISI:000381180000001, title = {Targeted quantification of N-1-(carboxymethyl) valine and N-1-(carboxyethyl) valine peptides of beta-hemoglobin for better diagnostics in diabetes}, journal = {Clinical Proteomics}, volume = {13}, year = {2016}, month = {MAR}, pages = {Article Number: 7}, publisher = {BIOMED CENTRAL LTD}, address = {236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND}, abstract = {

Background: N-1-(Deoxyfructosyl) valine (DFV) beta-hemoglobin (beta-Hb), commonly referred as HbA1c, is widely used diagnostic marker in diabetes, believed to provide glycemic status of preceding 90-120 days. However, the turnover of hemoglobin is about 120 days, the DFV-beta-Hb, an early and reversible glycation product eventually may undergo irreversible advanced glycation modifications such as carboxymethylation or carboxyethylation. Hence quantification of N-1-(carboxymethyl) valine (CMV) and N-1-(carboxyethyl) valine (CEV) peptides of beta-Hb would be useful in assessing actual glycemic status. Results: Fragment ion library for synthetically glycated peptides of hemoglobin was generated by using high resolution-accurate mass spectrometry (HR/AM). Using parallel reaction monitoring, deoxyfructosylated, carboxymethylated and carboxyethylated peptides of hemoglobin were quantified in clinical samples from healthy control, pre-diabetes, diabetes and poorly controlled diabetes. For the first time, we report N-1-beta-valine undergoes carboxyethylation and mass spectrometric quantification of CMV and CEV peptides of beta-hemoglobin. Carboxymethylation was found to be the most abundant modification of N-1-beta-valine. Both CMV-beta-Hb and CEV-beta-Hb peptides showed better correlation with severity of diabetes in terms of fasting glucose, postprandial glucose and microalbuminuria. Conclusions: This study reports carboxymethylation as a predominant modification of N-1-beta-valine of Hb, and quantification of CMV-beta-Hb and CEV-beta-Hb could be useful parameter for assessing the severity of diabetes.

}, keywords = {Diabetes, Diagnosis, Glycation, Glycemic control, HbA1c, Mass spectrometry}, issn = {1542-6416}, doi = {10.1186/s12014-016-9108-y}, author = {Jagadeeshaprasad, Mashanipalya G. and Batkulwar, Kedar B. and Meshram, Nishita N. and Tiwari, Shalbha and Korwar, Arvind M. and Unnikrishnan, Ambika G. and Kulkarni, Mahesh J.} } @article {45443, title = { Albumin abundance and its glycation Status determine hemoglobin glycation}, journal = {ACS Omega}, volume = {3}, year = {2018}, month = {OCT}, pages = {12999-13008}, type = {Article}, abstract = {Diabetes diagnosis and management majorly depend upon the measurement of glycated hemoglobin (HbAlc) levels. Various factors influence HbAlc levels such as the use of various analytical methods and the presence of various clinical conditions. Plasma albumin levels were known to be negatively associated with HbAlc. However, the precise mechanism by which they affect HbAlc is not well{\textquoteright} understood. Therefore, we have studied the influence of albumin levels and its glycation status on hemoglobin glycation using erythrocyte culture experiments. Erythrocytes maintained at low albumin concentration exhibited relatively increased albumin and hemoglobin glycation as compared to that in those maintained at higher albumin concentration. Increase in albumin glycation may decrease its ability to protect hemoglobin glycation. This was demonstrated by treatment of erythrocytes with N(epsilon-(carboxymethyl)lysine-modified serum albumin (CMSA), which failed to protect hemoglobin glycation; instead, it increased hemoglobin glycation. The inability of CMSA to reduce hemoglobin glycation was due to the lack of free lysine residues of albumin, which was corroborated by using N(epsilon-(acetyI)lysine serum albumin (AcSA) and clinical diabetic plasma. This is the first study which demonstrates that the modification of lysine residues of albumin impairs its ability to inhibit hemoglobin glycation. Furthermore, correlation studies between HbAlc and albumin levels or relative albumin fructosamine from clinical subjects supported our experimental finding that albumin abundance and its glycation status influence hemoglobin glycation. Therefore, we propose albumin level and its glycation status to be quantified in conjunction with HbAlc for better management of diabetes.}, doi = {10.1021/acsomega.8b01702}, author = {Jagadeeshaprasad, Mashanipalya G. and Venkatasubramani, Vinashya and Unnikrishnan, Ambika G. and Kulkarni, Mahesh J.} } @article {46685, title = {CD44, a predominant protein in methylglyoxal-induced secretome of muscle cells, is elevated in diabetic plasma}, journal = {ACS Omega}, volume = {5}, year = {2020}, month = {OCT }, pages = {25016-25028}, type = {Article}, abstract = {

Methylglyoxal (MG), a glycolytic intermediate and reactive dicarbonyl, is responsible for exacerbation of insulin resistance and diabetic complication. In this study, NIG-induced secretome of rat muscle cells was identified and relatively quantified by SWATH-MS. A total of 643 proteins were identified in MG induced{\textquoteright} secretome, of which 82 proteins were upregulated and 99 proteins were downregulated by more than 1.3-fold in SWATH analysis. Further, secretory proteins from the dassical secretory pathway and nonclassical secretory pathway were identified using SignalP and SecretomeP, respectively. A total of 180 proteins were identified with SignalP, and 113 proteins were identified with SecretomeP. The differentially expressed proteins were functionallyannotated by KEGG pathway analysis using Cytoscape soft ware with plugin clusterMaker. The differentially expressed proteins were{\textquoteright}sfound to he involved m various pathways like extracellular matrix (ECM) receptor interaction, leukocyte transendothelial migration, fluid shear tress and atherosclerosis, complement and coagulation cascades, and lysosomal pathway. Since the MG levels are high in diabetic conditions, the presence of MG-induced isecreted proteins was inspected {\textquoteleft}by profiling human plasma of healthy and diabetic subjects (n = 10 each). CD44, a predominant MG -induced secreted protein, was found to be elevated in the diabetic plasma and to have a role in the development of insulin resistance.

}, issn = {2470-1343}, doi = {10.1021/acsomega.0c01318}, author = {Bai, Shakuntala and Chaurasiya, Arvindkumar H. and Banarjee, Reema and Walke, Prachi B. and Rashid, Faraz and Unnikrishnan, Ambika G. and Kulkarni, Mahesh J.} } @article {48748, title = {Elevated level of glycated KQTALVELVK peptide of albumin is associated with the risk of diabetic nephropathy}, journal = {ACS Omega}, volume = {8}, year = {2023}, month = {JUN }, pages = {20654-20660}, type = {Article}, abstract = {

Diabetic nephropathyis a leading cause of end-stagerenal disease.Hence, early detection of diabetic nephropathy is essential to mitigatethe disease burden. Microalbuminuria, the currently used diagnosticmarker of diabetic nephropathy, is not efficient in detecting it atan early stage. Therefore, we explored the utility of glycated humanserum albumin (HSA) peptides for risk prediction of diabetic nephropathy.Three glycation-sensitive HSA peptides, namely, FKDLG-EENFK,KQTAL-VELVK, and KVPQVST-PTLVEVSR, with deoxyfructosyllysine(DFL) modification were quantified by targeted mass spectrometry (MS)in a study population comprising healthy and type II diabetes subjectswith and without nephropathy. Mass spectrometry, receiver operatingcharacteristic (ROC) curve, and correlation analysis revealed thatthe DFL-modified KQTALVELVK peptide was better than other glycatedHSA peptides and HbA(1c) for identifying diabetic nephropathy.DFL-modified KQTALVELVK could be a potential marker for risk predictionof diabetic nephropathy.

}, issn = {2470-1343}, doi = {10.1021/acsomega.3c01219}, author = {Chaurasiya, Arvindkumar H. and Jaiswal, Meera R. and Bayatigeri, Santhakumari and Kahar, Shweta and Tiwari, Shalbha and Unnikrishnan, Ambika G. and Kulkarni, Mahesh J.} }