Analysis of Crude, Diverse, and Multiple Advanced Glycation End-Product Patterns May Be Important and Beneficial

Abstract

Lifestyle-related diseases (LSRDs), such as diabetes mellitus, cardiovascular disease, and nonalcoholic steatohepatitis, are a global crisis. Advanced glycation end-products (AGEs) have been extensively researched because they trigger or promote LSRDs. Recently, techniques such as fluorimetry, immunostaining, Western blotting, slot blotting, enzyme-linked immunosorbent assay, gas chromatography-mass spectrometry, matrix-assisted laser desorption-mass spectrometry (MALDI-MS), and electrospray ionization-mass spectrometry (ESI-MS) have helped prove the existence of intra/extracellular AGEs and revealed novel AGE structures and their modifications against peptide sequences. Therefore, we propose modifications to the existing categorization of AGEs, which was based on the original compounds identified by researchers in the 20th century. In this investigation, we introduce the (i) crude, (ii) diverse, and (iii) multiple AGE patterns. The crude AGE pattern is based on the fact that one type of saccharide or its metabolites or derivatives can generate various AGEs. Diverse and multiple AGE patterns were introduced based on the possibility of combining various AGE structures and proteins and were proven through mass analysis technologies such as MALDI-MS and ESI-MS. Kampo medicines are typically used to treat LSRDs. Because various compounds are contained in Kampo medicines and metabolized to exert effects on various organs or tissues, they may be suitable against various AGEs.

Keywords: Kampo medicines; advanced glycation end-products (AGEs); crude AGE pattern; diverse AGE pattern; electrospray ionization-mass spectrometry (ESI-MS); gas chromatography-mass spectrometry (GC-MS); lifestyle-related disease (LSRD); matrix-assisted laser desorption-mass spectrometry (MALDI-MS); multiple AGE pattern.

Figure 1

Model image of the preparation of a CEL-ester derivative for GC-MS analysis. Closed blue circles represent amino acids. Closed peach squares represent compounds that have hydroxyl groups. CEL: N^ε-carboxyethyl-lysine.

Figure 2

Hydrochloride hydrolysis of various CEL-modified proteins and production of free CEL for analysis using MALDI-MS or ESI-MS. CEL: N^ε-carboxyethyl-lysine; MALDI-MS, matrix-assisted laser desorption-mass spectrometry; ESI-MS, electrospray ionization-mass spectrometry.

Figure 3

Model image of MALDI-MS or ESI-MS analysis of GLAP-modified protein. GLAP, glyceraldehyde-derived pyridinium; MALDI-MS, matrix-assisted laser desorption-mass spectrometry; ESI-MS, electrospray ionization-mass spectrometry.

Figure 4

New model of categorizing MGO-AGEs and GA-AGEs. Numbers indicate references. MGO-AGEs, methylglyoxal-derived AGEs; GA-AGEs, glyceraldehyde-derived AGEs; CML, N^ε-carboxymethyl-lysine [55,97]; CEL, N^ε-carboxyethyl-lysine [55,96]; MOLD, methylglyoxal-lysine dimer (1,3-di(N^ε-lysino)-4-methyl-imidazolium salt) [5,60]; MG-H1, N^ε-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine [91,93,94]; Argpyrimidine [92,95,96]; GLAP, glyceraldehyde-derived pyridinium [87,88,89]; TAGE, toxic AGEs [2,5]; Triosidines [90].

Figure 5

Illustration of the generation and accumulation of various AGEs in PANC-1 cells treated with glyceraldehyde [28] via the crude AGE pattern. GA, glyceraldehyde; Arg-P, argpyrimidine; MG-H1, N^δ-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine. GLAP, glyceraldehyde-derived pyridinium; AGEs, advanced glycation end-products.

Figure 6

Type 1 diverse AGE pattern. Each protein A can be modified by MG-H1, Arg-P, and CEL. Blue closed circles indicate the amino acids. MG-H1, N^δ-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine; Arg-P: argpyrimidine; CEL, N^ε-carboxyethyl-lysine.

Figure 7

MG-H1 and argypyrimidine-modified peptides in HSP27 [31]. Closed blue circles represent amino acids. Numbers indicate amino acids in the HSP27 sequence. MG-H1, N^δ-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine; Arg-P: argpyrimidine; (a) The amino acid sequence: HGYISRCFTR (131–140). (b) Amino acid sequence: SRAQJGGPEAAR (187–198).

Figure 8

Type 2 diverse AGE pattern. CEL-modified proteins A–C [32]. Closed blue circles represent amino acids. CEL, N^ε-carboxyethyl-lysine.

Figure 9

Model of the type I multiple AGE pattern and the MALDI-MS or ESI-MS analysis of Arg-P-, MG-H1-, and CEL-modified proteins. The peptide modified with two MG-H1s verified the type I multiple AGE pattern. Closed blue circles represent amino acids. Arg-P: argpyrimidine; MG-H1, N^δ-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine; CEL, N^ε-carboxyethyl-lysine.

Figure 10

Two MG-H1-modified peptides (65–87 and 88–96) in recombinant human HSP27 [31]. Closed blue circles represent amino acids. Numbers indicate amino acids in the HSP27 sequence. MG-H1, N^δ-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine. (a) The amino acid sequence: SPAVAAPAYSRALSRQJSSGVSE (65–87). (b) The amino acid sequence: IRHTADRWR (88–96).

Figure 11

Model image of the type II multiple AGE pattern shows only an intermolecular covalent bond. D1: AGE structure that can combine between the second amino acid residue in protein A and the third amino acid residue in protein B. Closed blue circles represent amino acids; black and red numbers represent the number of amino acid residues in proteins A and B, respectively.

Figure 12

Model image of the type II multiple AGE pattern shows both inter- and intramolecular covalent bonds. D1: AGE structure combining the second amino acid residue in protein A and the third amino acid residue in protein B. D2: AGE structure combining the fourth and thirteenth amino acids in protein A. D1 and D2 are different AGE structures. A closed black plow represents an anti-D2-antibody. Closed blue circles represent amino acids; black and red numbers represent the number of amino acid residues in proteins A and B, respectively.

Figure 13

MALDI-MS or ESI-MS analysis of the protein A and B complex, combined via D1. D1: AGE structure that can combine the second amino acid residue in protein A and the third amino acid residue in protein B. Closed blue circles indicate amino acids. Black and red numbers represent the number of amino acid residues in proteins A and B, respectively.

Figure 14

Modern Kampo medicines from Tsumura Co. (Tokyo, Japan) (a) Tokishakuyakusan (2.5 g) packaged for use in hospitals or pharmacies. (b) Tokishakuyakusan (2.5 g). (c) Orento in a bottle, prepared for research at Kanazawa Medical University but not for use in hospitals or pharmacies. (d) Orento.

Figure 15

Schematic diagram of oral Kampo medicine administration in the body. Medicines are digested in the stomach, absorbed in the small intestine, metabolized in the liver, passed into the blood, and transported to various organs and tissues.