Noninvasive analysis of skin proteins in healthy Chinese subjects using an Orbitrap Fusion Tribrid mass spectrometer

The proteome of hand eczema assessed by tape stripping

Hand eczema (HE) is a prevalent skin disease. However, classification of HE into different subtypes remains challenging. Limited number of prior studies have employed invasive biopsy-based strategies; yet, studies of the HE proteome using non-invasive tape stripping methodology have not been reported. In this study, we wanted to assess whether global proteomic analysis of skin tape strip samples can be used for sub-classification of HE patients. Tape strips were collected from patients with HE and healthy skin. Liquid chromatography-mass spectrometry (LC/MS) proteomics was performed, and the global protein expression was analyzed. We identified 2,919 proteins in stratum corneum-derived skin cells from tape strip samples. Compared to healthy skin, the lesional samples from HE patients exhibited increased expression of immune-related markers and a decreased expression of structural barrier proteins. The difference between HE subtypes was restricted to the lesional skin areas, and included an increased expression of skin barrier-related proteins independently of the concurrent AD. In conclusion we found, that the non-invasive tape strip method used in combination with LC/MS proteomics can be used for analysis of skin protein expression in HE patients. Thus, the method shows potential for assessing the proteomic differences between subtypes of HE, and biomarker discovery.

Comparative Proteomics Combined with Morphophysiological Analysis Revealed Chilling Response Patterns in Two Contrasting Maize Genotypes

Maize yield is significantly influenced by low temperature, particularly chilling stress at the maize seedling stage. Various physiological approaches have been established to resist chilling stress; however, the detailed proteins change patterns underlying the maize chilling stress response at the seedling stage remain unknown, preventing the development of breeding-based methods to resist chilling stress in maize. Thus, we performed comprehensive physiological, comparative proteomics and specific phytohormone abscisic acid (ABA) assay on different maize inbred lines (tolerant-line KR701 and sensitive-line hei8834) at different seedling stages (the first leaf stage and third leaf stage) under chilling stress. The results revealed several signalling proteins and pathways in response to chilling stress at the maize seedling stage. Meanwhile, we found ABA pathway was important for chilling resistance of tolerant-line KR701 at the first leaf stage. Related chilling-responsive proteins were further catalogued and analysed, providing a resource for further investigation and maize breeding.

Hexokinase 2-driven glycolysis in pericytes activates their contractility leading to tumor blood vessel abnormalities

Defective pericyte-endothelial cell interaction in tumors leads to a chaotic, poorly organized and dysfunctional vasculature. However, the underlying mechanism behind this is poorly studied. Herein, we develop a method that combines magnetic beads and flow cytometry cell sorting to isolate pericytes from tumors and normal adjacent tissues from patients with non-small cell lung cancer (NSCLC) and hepatocellular carcinoma (HCC). Pericytes from tumors show defective blood vessel supporting functions when comparing to those obtained from normal tissues. Mechanistically, combined proteomics and metabolic flux analysis reveals elevated hexokinase 2(HK2)-driven glycolysis in tumor pericytes, which up-regulates their ROCK2-MLC2 mediated contractility leading to impaired blood vessel supporting function. Clinically, high percentage of HK2 positive pericytes in blood vessels correlates with poor patient overall survival in NSCLC and HCC. Administration of a HK2 inhibitor induces pericyte-MLC2 driven tumor vasculature remodeling leading to enhanced drug delivery and efficacy against tumor growth. Overall, these data suggest that glycolysis in tumor pericytes regulates their blood vessel supporting role.

Pericyte-endothelial cells interaction defines tumor vasculature and has implications in tumorigenesis development and therapy efficacy. Here, the authors show that hexokinase 2- driven glycolysis activates ROCK1-MLC2 mediated contractility in pericytes leading to tumor blood vessel abnormality.

Quantitative proteomics analysis of young and elderly skin with DIA mass spectrometry reveals new skin aging-related proteins

Skin aging is a specific manifestation of the physiological aging process that occurs in virtually all organisms. In this study, we used data independent acquisition mass spectrometry to perform a comparative analysis of protein expression in volar forearm skin samples from of 20 healthy young and elderly Chinese individuals. Our quantitative proteomic analysis identified a total of 95 differentially expressed proteins (DEPs) in aged skin compared to young skin. Enrichment analyses of these DEPs (57 upregulated and 38 downregulated proteins) based on the GO, KEGG, and KOG databases revealed functional clusters associated with immunity and inflammation, oxidative stress, biosynthesis and metabolism, proteases, cell proliferation, cell differentiation, and apoptosis. We also found that GAPDH, which was downregulated in aged skin samples, was the top hub gene in a protein-protein interaction network analysis. Some of the DEPs identified herein had been previously correlated with aging of the skin and other organs, while others may represent novel age-related entities. Our non-invasive proteomics analysis of human epidermal proteins may guide future research on skin aging to help develop treatments for age-related skin conditions and rejuvenation.