Data-independent acquisition-based proteomics analysis correlating type 2 diabetes mellitus with osteoarthritis in total knee arthroplasty patients.

BACKGROUND: To explore the effects of type 2 diabetes mellitus (T2DM) on osteoarthritis (OA), 12 bone tissue samples were obtained surgically from the human total knee arthroplasty patients and analyzed by quantitative proteomics. METHODS: Based on patient clinical histories, patient samples were assigned to diabetes mellitus osteoarthritis (DMOA) and OA groups. A data-independent acquisition method for data collection was used with proteomic data analysis to assess intergroup proteomic differences. Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genome pathway enrichment analysis were used to further find the correlation between T2DM and OA. RESULTS: GO functional analysis found 153 differentially expressed proteins between DMOA and OA groups, of which 92 differentially expressed proteins were significantly up-regulated and 61 were significantly down-regulated. Kyoto Encyclopedia of Genes and Genome pathway analysis found 180 pathways, including 9 pathways significantly enriched. Further data analysis revealed that 6 signaling pathways were closely associated with T2DM and OA. CONCLUSION: OA and DMOA onset and progression were closely related to synthesis and metabolism of extracellular matrix components (e.g., fibronectin, decorin, etc.). The effects of T2DM on OA occur though 2 major ways of oxidative stress and low-grade chronic inflammation, involving in 2 inhibited signaling pathways and 4 activated signaling pathways.

Peptide-drug conjugate-based novel molecular drug delivery system in cancer.

Drug delivery systems are generally believed to comprise drugs and excipients. A peptide-drug conjugate is a single molecule that can simultaneously play multiple roles in a drug delivery system, such as in vivo drug distribution, targeted release, and bioactivity functions. This molecule can be regarded as an integrated drug delivery system, so it is called a molecular drug delivery system. In the context of cancer therapy, a peptide-drug conjugate comprises a tumor-targeting peptide, a payload, and a linker. Tumor-targeting peptides specifically identify membrane receptors on tumor cells, improve drug-targeted therapeutic effects, and reduce toxic and side effects. Payloads with bioactive functions connect to tumor-targeting peptides through linkers. In this review, we explored ongoing clinical work on peptide-drug conjugates targeting various receptors. We discuss the binding mechanisms of tumor-targeting peptides and related receptors, as well as the limiting factors for peptide-drug conjugate-based molecular drug delivery systems.

Relative quantitation analysis of the substrate specificity of glutamyl endopeptidase with bovine α-caseins.

A bovine α-caseins' preparation digested with glutamyl endopeptidase (GE) at 37 and 50°C was quantitatively analysed with the isobaric tag for relative and absolute quantification (iTRAQ) technique using nano-LC-ESI-QTOF-MS/MS. Incubation temperature was shown to affect protein digestion. MS analysis of the digestion products indicated that phosphorylated peptides were less sensitive than non-phosphorylated peptides according to the MS intensities. GE hydrolysed Glu(51)-Tyr(52) and Glu(50)-Glu(51) in Glu(49)-Glu(50)-Glu(51)-Tyr(52) of bovine αs1-casein. The results herein helped to confirm the precise process of α-caseins' hydrolysis with GE, which is significant for quantifying the release of bio- and techno-functional peptides.