Proteomics最新文献

The development of the gut microbiome in infancy is a vulnerable process that may be perturbed by antibiotics or supported by probiotics. Although effects of these "biotics" have been well-studied through DNA sequencing, it remains unclear how the resulting compositional changes affect the microbiome metabolic functions. Additionally, limits in method standardization require careful quality assessment of studies reporting fecal metabolome. We conducted a systematic search in Embase and MEDLINE for studies describing fecal metabolites from term and near-term infants, together with anti-, pre-, or probiotic intervention. The search identified 680 articles, of which 60 were assessed for eligibility and 21 were included. We first developed operational checklists for transparent and reproducible reporting and evaluated the quality of metabolomic methodologies. This analysis supported our aim to summarize changes in the fecal metabolome induced by biotic interventions. Despite a varying quality of metabolomic methodology, we identified similarities in the fecal metabolome profiles in response to specific biotic interventions. Among the most frequently observed metabolites, which were consistently reported to be altered after biotic interventions, were bile acids, aromatic amino acids, and short-chain fatty acids. We conclude with a discussion on appropriate experimental design, controls, and metabolomics reporting to guide future research permitting meta-analyses.

Compared to regular tumor cells, cancer stem cells exhibit dangerous characteristics, including high proliferation, high metastatic potential, and significantly increased in vivo tumorigenicity. Although some studies have emphasized the impact of the microenvironment on cell stemness, they have largely overlooked the mechanical forces derived from the stiffness of the surrounding extracellular matrix. Our previous research demonstrated that a 90 Pa soft fibrin matrix in three-dimensional (3D) culture can induce cells to become cancer repopulating cells with high stemness. Acetylation modification significantly influences the metabolism, epigenetics, proliferation, migration, and immune evasion of tumor cells. In this study, we performed a comprehensive analysis of the proteome and acetyl-proteome of breast cancer cells under two-dimensional (2D) plate and 3D matrix conditions with varying stiffness. This dataset provides a valuable resource for understanding the dynamic regulation of protein acetylation in response to mechanical stiffness. The mass spectrometry-based proteomics data have been uploaded to the ProteomeXchange Consortium with the dataset identifier PXD057820.

Bacillus cereus translocator protein (BcTSPO) is a transmembrane protein that plays a regulatory role in various Bacillus cereus phenotypes, potentially including its virulence. Given that the exoproteome is a major determinant of B. cereus virulence, particularly during the late stages of active growth, its analysis is crucial for understanding the regulatory functions of BcTSPO. In this study, we conducted a comparative analysis of the exoproteomes and cellular proteomes of a Δtspo mutant and the wild-type ATCC 14579 strain during the late exponential and early stationary growth phases. Shotgun proteomics revealed that the absence of BcTSPO significantly depleted the exoproteome of secreted virulence factors, including the HBL, NHE, and CytK enterotoxins. Interestingly, the cholesterol-dependent cereolysin O (CLO) was more abundant in the Δtspo exoproteome, indicating a distinct regulatory mechanism. The cellular proteome analysis further confirmed that BcTSPO positively regulates, likely indirectly, the synthesis of enterotoxins and negatively regulates the production of CLO. Additionally, the Δtspo exoproteome was enriched in moonlighting proteins, reflecting the impact of BcTSPO absence on cellular metabolism and stress responses. Overall, these findings highlight the critical role of BcTSPO in shaping the composition of both the exoproteome and cellular proteome, with significant implications for the virulence of B. cereus.

Diet has been shown to greatly impact the intestinal microbiota. To understand the role of individual dietary components, defined diets with purified components are frequently used in diet-microbiota studies. Defined diets frequently use purified casein as the protein source. Previous work indicated that casein contains microbial DNA potentially impacting results of microbiome studies. Other diet-based microbially derived molecules that may impact microbiome measurements, such as proteins detected by metaproteomics, have not been determined for casein. Additionally, other protein sources used in microbiome studies have not been characterized for their microbial content. We used metagenomics and metaproteomics to identify and quantify microbial DNA and protein in a casein-based defined diet to better understand potential impacts on metagenomic and metaproteomic microbiome studies. We further tested six additional defined diets with purified protein sources with an integrated metagenomic-metaproteomic approach and found that contaminating microbial protein is unique to casein within the tested set as microbial protein was not identified in diets with other protein sources. We also illustrate the contribution of diet-derived microbial protein in diet-microbiota studies by metaproteomic analysis of stool samples from germ-free mice (GF) and mice with a conventional microbiota (CV) following consumption of diets with casein and non-casein protein. This study highlights a potentially confounding factor in diet-microbiota studies that must be considered through evaluation of the diet itself within a given study.

Human males and females show differences in the incidence of neutrophil-associated diseases and differences in neutrophil responses such as a faster response to the chemorepellent Ser-Leu-Ile-Gly-Lys-Val-NH2 (SLIGKV) in males. Little is known about the basis of sex-based differences in human neutrophils. We used mass spectrometry to identify proteins and phosphoproteins in unstimulated human neutrophils and in neutrophils incubated with the SLIGKV, a protease-activated receptor 2 agonist. There were 132 proteins with higher levels in unstimulated male neutrophils; these proteins tended to be associated with RNA regulation, ribosome, and phosphoinositide signaling pathways, whereas 30 proteins with higher levels in unstimulated female neutrophils were associated with metabolic processes, proteasomes, and phosphatase regulatory proteins. Unstimulated male neutrophils had increased phosphorylation of 32 proteins compared to females. After exposure to SLIGKV, male neutrophils showed a faster response in terms of protein phosphorylation compared to female neutrophils. Male neutrophils have higher levels of proteins and higher phosphorylation of proteins associated with RNA processing and signaling pathways. Female neutrophils have higher levels of proteins associated with metabolism and proteolytic pathways. This suggests that male neutrophils might be more ready to adapt to a new environment, and female neutrophils might be more effective at responding to pathogens.

We aim to verify and validate low-abundant plasma proteins from severe COVID-19 cases and controls through a comparative analysis between Olink and Alamar performances. Eighty-three severe cases and 44 controls were measured for proteomics using three Olink panels and one Alamar panel, which share 94 targets. CV, pairwise correlation of intensity signals, and detectability range were compared across platforms. Statistical comparisons were performed using FDR-adjusted linear models with age as a covariate to construct differential protein abundance volcano plots between cases and controls per platform and heatmaps between our cohort and five public cohorts. Overall, pairwise comparisons (n = 94) showed strong correlations among cases (r = 0.82) and controls (r = 0.7). 60/94 proteins had mutual significance on both platforms; of which 54 showed concordant effect direction, and six showed opposite effect direction (IL-6R, IL-1R2, KITLG, TSLP, IL-17C, and IL-4R). Alamar verified 80 and 60 targets from cases and controls, respectively, along with 54 differential proteins from Olink. Compared to public cohorts measured by Olink, our Olink data showed consistent findings from 28 proteins, of which 27 were validated by Alamar.

CITE-Seq (Cellular Indexing of Transcriptomes and Epitopes by Sequencing) is an advanced single-cell sequencing method to profile both gene expression and protein abundance simultaneously in individual cells using single-cell mRNA sequencing techniques alongside antibody-derived tags (ADTs), for protein detection. The characterization of both the transcriptome and the proteome from the same cells provides a powerful and multiomic approach for understanding the mechanisms of complex biological processes. This review focuses on the workflow of CITE-Seq using a microwell-based single-cell analysis system as an example and provides key considerations for staining cells with ADTs. By highlighting critical information for CITE-Seq library preparation, sequencing, and data analysis, this review provides a practical guide with which to perform comprehensive CITE-Seq workflow.