02850nas a2200181 4500008004100000245011200041210006900153260000800222520215600230100001602386700002002402700002902422700001402451700002102465700002502486700002502511856013202536 2019 eng d00aGlycation of glucose sensitive lysine residues K36, K438 and K549 of albumin is associated with prediabetes0 aGlycation of glucose sensitive lysine residues K36 K438 and K549 cAUG3 a

Prediabetes is a risk factor for the development of diabetes. Early diagnosis of prediabetes may prevent the onset and progression of diabetes and its associated complications. Therefore, this study aimed at the identification of novel markers for efficient prediction of prediabetes. In this pursuit, we have evaluated the ability of glycated peptides of albumin in predicting prediabetes. Glycated peptides of in vitro glycated albumin were characterized by data dependent acquisition and parallel reaction monitoring using LC-HRMS. Amongst 14 glycated peptides characterized in vitro, four peptides, particularly, FK(CML)DLGEENFK, K(AML)VPQVSTPTLVEVSR, K(CML)VPQVSTPTLVEVSR, and K(AML)QTALVELVK, corresponding to 3 glucose sensitive lysine residues K36, K438, and K549, respectively showed significantly higher abundance in prediabetes than control. Additionally, the abundance of three of these peptides, namely K(AML)QTALVELVK, K(CML)VPQVSTPTLVEVSR and FK(CML)DLGEENFK was >1.8-fold in prediabetes, which was significantly higher than the differences observed for FBG, PPG, and HbA1c. Further, the four glycated peptides showed a significant correlation with FBG, PPG, HbA1c, triglycerides, VLDL, and HDL. This study supports that glycated peptides of glucose sensitive lysine residues K36, K438 and K549 of albumin could be potentially useful markers for prediction of prediabetes. SIGNIFICANCE: Undiagnosed prediabetes may lead to diabetes and associated complications. This study reports targeted quantification of four glycated peptides particulary FK(CML)DLGEENFK, K(AML)VPQVSTPTLVEVSR, K(CML)VPQVSTPTLVEVSR, and K(AML)QTALVELVK, corresponding to 3 glucose sensitive lysine residues K36, K438 and K549 respectively by parallel reaction monitoring in healthy and prediabetic subjects. These peptides showed significantly higher abundance in prediabetes than healthy subjects, and showed significant correlation with various clinical parameters including FBG, PPG, HbA1c, and altered lipid profile. Therefore, together these four peptides constitute a panel of markers that can be useful for prediction of prediabetes.

1 aRathore, R.1 aSonwane, B., P.1 aJagadeeshaprasad, M., G.1 aKahar, S.1 aSanthakumari, B.1 aUnnikrishnan, A., G.1 aKulkarni, Mahesh, J. uhttps://library.ncl.res.in/content/glycation-glucose-sensitive-lysine-residues-k36-k438-and-k549-albumin-associated-prediabetes02148nas a2200193 4500008004100000245010200041210006900143260000900212300001200221490000700233520143900240100002701679700002301706700002401729700002501753700002701778700002501805856012401830 2020 eng d00aDevelopment of multiple reaction monitoring assay for quantification of carnosine in human plasma0 aDevelopment of multiple reaction monitoring assay for quantifica cJAN  a763-7690 v103 a

Carnosine, a histidine containing dipeptide, exerts beneficial effects by scavenging reactive carbonyl compounds (RCCs) that are implicated in pathogenesis of diabetes. However, the reduced carnosine levels may aggravate the severity of diabetes. The precise quantification of carnosine levels may serve as an indicator of pathophysiological state of diabetes. Therefore, we have developed a highly sensitive targeted multiple reaction monitoring (MRM) method for quantification of carnosine in human plasma samples. Various mass spectrometry parameters such as ionization of precursor, fragment abundance and stability, collision energy, tube lens offset voltage were optimized to develop a sensitive and robust assay. Using the optimized MRM assay, the lower limit of detection (LOD) and limit of quantification (LOQ) for carnosine were found to be 0.4 nM and 1.0 nM respectively. Standard curves were constructed ranging from 1.0 nM to 15.0 mu M and the levels of carnosine in mice and human plasma were determined. Further, the MRM assay was extended to study carnosine hydrolyzing activity of human carnosinases, the serum carnosinase (CN1) and the cytosolic carnosinase (CN2). CN1 showed three folds higher activity than CN2. The MRM assay developed in this study is highly sensitive and can be used for basal plasma carnosine quantification, which can be developed as a novel marker for scavenging of RCCs in diabetes.

1 aPandya, Vaibhav, Kumar1 aSonwane, Babasaheb1 aRathore, Rajeshwari1 aUnnikrishnan, A., G.1 aKumaran, Sangaralingam1 aKulkarni, Mahesh, J. uhttps://library.ncl.res.in/content/development-multiple-reaction-monitoring-assay-quantification-carnosine-human-plasma01638nas a2200265 4500008004100000022001400041245014600055210007000201260000800271300001400279490000700293520073700300653000801037653002001045653001301065653001401078653002001092653000801112100002401120700002001144700002801164700002501192700002501217856013001242 2025 eng d a0973-393000aAutoantibodies against Nε-carboxymethyl lysine and methylglyoxal modified albumin are associated with cardiovascular risk in type 2 diabetes0 aAutoantibodies against Nεcarboxymethyl lysine and methylglyoxal  cDEC a1104-11100 v453 a

{Background Albumin is an abundant plasma protein which gets modified with advanced glycation end products (AGEs) predominantly in diabetic condition. AGE modification induces immune response and autoantibodies are generated which play an important role in disease pathology. Objective This study aimed to illustrate the role of autoantibodies against N epsilon-carboxymethyl lysine (CML) and methylglyoxal (MG) modified albumin in diabetic cardiovascular complications. MethodsType-2 diabetes subjects were enrolled and further grouped into stress test positive or stress test negative based on treadmill stress test (TMT). Autoantibody titer was quantified by ELISA assay for CML-modified albumin (stress test positive

10aAGE10aAtherosclerosis10aDiabetes10aGlycation10aImmune response10aROC1 aPatil, Yugendra, R.1 aTiwari, Shalbha1 aMomin, Abdulrahaman, A.1 aUnnikrishnan, A., G.1 aKulkarni, Mahesh, J. uhttps://library.ncl.res.in/content/autoantibodies-against-n%CE%B5-carboxymethyl-lysine-and-methylglyoxal-modified-albumin-are02383nas a2200253 4500008004100000022001400041245009700055210006900152260000800221300001200229490000700241520151000248653002701758653001301785653003301798653001901831653002101850653003501871100002401906700002001930700002501950700002501975856012902000 2025 eng d a1937-538700aProteome profile of stress test assessed cardiovascular disease risk-prone diabetic subjects0 aProteome profile of stress test assessed cardiovascular disease  cAUG a960-9690 v183 a

Cardiovascular disease (CVD) is the leading cause of death in the diabetic population. There is a need for specific predictive markers to assess CVD risk. The present study explored the plasma proteome profile of treadmill test (TMT) assessed diabetic stress test positive (DSTP) and diabetic stress test negative (DSTN) subjects by performing a SWATH-MS-based label-free quantitative mass spectrometry approach to identify differentially expressed proteins (DEPs). CVD-relevant DEPs were further validated using a targeted mass spectrometry approach (MRM-HR). It was observed that CO4B, PON1 and LUM exhibited considerable differential expression in both the MS approaches, and ROC analysis showed significant AUC (0.97, 0.79 and 0.77, respectively). Overall, the present study reports these proteins as potential alternative markers for TMT in assessing CVD risk. These markers can possibly overcome the limitations of TMT with further validation in the large cohort.Graphical AbstractAn overview of experimental approaches used in the current study. The study design depicts diabetic subjects assessed for cardiovascular risk by TMT or stress test. The experimental design shows the use of the SWATH-MS approach to identify differentially expressed proteins and validate CVD-related proteins with targeted MS approaches such as MRM-HR. Finally, CO4B, PON1 and LUM exhibited significant AUC in ROC analysis, indicating their potential marker capabilities to predict CVD in diabetic subjects.

10acardiovascular disease10aDiabetes10aMultiple reaction monitoring10aPlasma markers10aProteome profile10aQuantitative mass spectrometry1 aPatil, Yugendra, R.1 aTiwari, Shalbha1 aUnnikrishnan, A., G.1 aKulkarni, Mahesh, J. uhttps://library.ncl.res.in/content/proteome-profile-stress-test-assessed-cardiovascular-disease-risk-prone-diabetic-subjects