ORCID Profile
0000-0002-9358-7036
Current Organisation
University Medical Center Hamburg-Eppendorf
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Publisher: Elsevier BV
Date: 05-2018
Abstract: Transporting biological s les such as cells or tissues is complicated by the need to maintain integrity and minimise modification and degradation, but this is economically costly as the s les must be shipped in a frozen state. This multi-laboratory study investigated s le variability introduced by non-cooled transport of dried peptide s les for proteomic analysis using mass spectrometry. Human cancer cell tryptic lysates were proteolysed and dried in Australia and shipped by air to Europe and China. S les were measured using label free mass spectrometry on similar LC-MS systems at all three sites. Preparation and analysis of the specimens in this manner resulted in only minor differences in protein identification and showed high quantitative reproducibility amongst the participating laboratories. We examined any impact on peptide chemical modification and report no discrepancies compared to the starting, non-shipped s le. We conclude that transport of non-cooled, dried peptides has negligible effect on s le integrity for downstream LC-MS analysis and therefore represents a cost-effective option to facilitate international proteomic collaborations. Data is available via ProteomeXchange with identifier PXD008160.
Publisher: Springer Science and Business Media LLC
Date: 14-08-2023
DOI: 10.1038/S41467-023-39740-7
Abstract: Kidney organoids are a promising model to study kidney disease, but their use is constrained by limited knowledge of their functional protein expression profile. Here, we define the organoid proteome and transcriptome trajectories over culture duration and upon exposure to TNFα, a cytokine stressor. Older organoids increase deposition of extracellular matrix but decrease expression of glomerular proteins. Single cell transcriptome integration reveals that most proteome changes localize to podocytes, tubular and stromal cells. TNFα treatment of organoids results in 322 differentially expressed proteins, including cytokines and complement components. Transcript expression of these 322 proteins is significantly higher in in iduals with poorer clinical outcomes in proteinuric kidney disease. Key TNFα-associated protein (C3 and VCAM1) expression is increased in both human tubular and organoid kidney cell populations, highlighting the potential for organoids to advance biomarker development. By integrating kidney organoid omic layers, incorporating a disease-relevant cytokine stressor and comparing with human data, we provide crucial evidence for the functional relevance of the kidney organoid model to human kidney disease.
Publisher: MDPI AG
Date: 04-04-2020
DOI: 10.3390/IJMS21072508
Abstract: TFF1 is a protective peptide of the Trefoil Factor Family (TFF), which is co-secreted with the mucin MUC5AC, gastrokine 2 (GKN2), and IgG Fc binding protein (FCGBP) from gastric surface mucous cells. Tff1-deficient mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas, indicating that Tff1 is a tumor suppressor. As a hallmark, TFF1 contains seven cysteine residues with three disulfide bonds stabilizing the conserved TFF domain. Here, we systematically investigated the molecular forms of TFF1 in the human gastric mucosa. TFF1 mainly occurs in an unusual monomeric form, but also as a homodimer. Furthermore, minor amounts of TFF1 form heterodimers with GKN2, FCGBP, and an unknown partner protein, respectively. TFF1 also binds to the mucin MUC6 in vitro, as shown by overlay assays with synthetic 125I-labeled TFF1 homodimer. The dominant presence of a monomeric form with a free thiol group at Cys-58 is in agreement with previous studies in Xenopus laevis and mouse. Cys-58 is likely highly reactive due to flanking acid residues (PPEEEC58EF) and might act as a scavenger for extracellular reactive oxygen/nitrogen species protecting the gastric mucosa from damage by oxidative stress, e.g., H2O2 generated by dual oxidase (DUOX).
Publisher: American Chemical Society (ACS)
Date: 17-07-2018
Publisher: MDPI AG
Date: 28-12-2022
Abstract: Alterations of the gut microbiome in cases of colorectal cancer (CRC) hint at the involvement of host–microbe interactions in the onset and progression of CRC and also, possibly, provide novel ways to detect and prevent CRC early. The aim of the present study was to evaluate whether the oral and fecal microbiomes of an in idual can be suitable for CRC screening. Oral and fecal s les (n = 80) were gathered in Taleghani hospital, affiliated with Shahid Beheshti University of Medical Sciences, Tehran–Iran, from CRC stage 0 and I patients and healthy controls (HCs), who were screened for the first time. Microbial metagenomics assays were performed for studying microbiota profiles in all oral and fecal s les gathered. An abundance of top bacterial genera from both types of specimens (fecal and saliva s les) revealed a distinction between CRC patients and HCs. In saliva s les, the α ersity index was different between the microbiome of HCs and CRC patients, while β ersity showed a densely clustered microbiome in the HCs but a more dispersed pattern in CRC cases. The α and β ersity of fecal microbiota between HCs and CRC patients showed no statistically significant differences. Bifidobacterium was identified as a potential bacterial biomarker in CRC saliva s les, while Fusobacterium, Dialister, Catonella, Tennerella, Eubacterium-brachy-group, and Fretibacterium were ideal to distinguish HCs from CRC patients. One of the reasons for the heterogeneity of CRC may be the gastrointestinal (GI) tract microbiota, which can also cause systematic resistance to CRC. Moreover, an evaluation of saliva microbiota might offer a suitable screening test for the early detection of this malignancy, providing more accurate results than its fecal counterpart.
Publisher: MDPI AG
Date: 19-02-2020
DOI: 10.3390/IJMS21041374
Abstract: Proteomics and genomics discovery experiments generate increasingly large result tables, necessitating more researcher time to convert the biological data into new knowledge. Literature review is an important step in this process and can be tedious for large scale experiments. An informed and strategic decision about which biomolecule targets should be pursued for follow-up experiments thus remains a considerable challenge. To streamline and formalise this process of literature retrieval and analysis of discovery based ‘omics data and as a decision-facilitating support tool for follow-up experiments we present OmixLitMiner, a package written in the computational language R. The tool automates the retrieval of literature from PubMed based on UniProt protein identifiers, gene names and their synonyms, combined with user defined contextual keyword search (i.e., gene ontology based). The search strategy is programmed to allow either strict or more lenient literature retrieval and the outputs are assigned to three categories describing how well characterized a regulated gene or protein is. The category helps to meet a decision, regarding which gene rotein follow-up experiments may be performed for gaining new knowledge and to exclude following already known biomarkers. We demonstrate the tool’s usefulness in this retrospective study assessing three cancer proteomics and one cancer genomics publication. Using the tool, we were able to corroborate most of the decisions in these papers as well as detect additional biomolecule leads that may be valuable for future research.
Publisher: Public Library of Science (PLoS)
Date: 10-06-2021
DOI: 10.1371/JOURNAL.PONE.0253084
Abstract: Rickettsioses are neglected and emerging potentially fatal febrile diseases that are caused by obligate intracellular bacteria, rickettsiae. Rickettsia ( R .) typhi and R . prowazekii constitute the typhus group (TG) of rickettsiae and are the causative agents of endemic and epidemic typhus, respectively. We recently generated a monoclonal antibody (BNI52) against R . typhi . Characterization of BNI52 revealed that it specifically recognizes TG rickettsiae but not the members of the spotted fever group (SFG) rickettsiae. We further show that BNI52 binds to protein fragments of ±30 kDa that are exposed on the bacterial surface and also present in the periplasmic space. These protein fragments apparently derive from the cytosolic GroEL protein of R . typhi and are also recognized by antibodies in the sera from patients and infected mice. Furthermore, BNI52 opsonizes the bacteria for the uptake by antigen presenting cells (APC), indicating a contribution of GroEL-specific antibodies to protective immunity. Finally, it is interesting that the GroEL protein belongs to 32 proteins that are differentially downregulated by R . typhi after passage through immunodeficient BALB/c CB17 SCID mice. This could be a hint that the rickettsia GroEL protein may have immunomodulatory properties as shown for the homologous protein from several other bacteria, too. Overall, the results of this study provide evidence that GroEL represents an immunodominant antigen of TG rickettsiae that is recognized by the humoral immune response against these pathogens and that may be interesting as a vaccine candidate. Apart from that, the BNI52 antibody represents a new tool for specific detection of TG rickettsiae in various diagnostic and experimental setups.
Publisher: Springer Science and Business Media LLC
Date: 14-02-2018
Location: No location found
No related grants have been discovered for Hartmut Schluter.