Biology subjects

Krutmann, J.

Publications and source records attributed to Krutmann, J..

6 recordsLinked to original sources

bioRxiv2025

Integrative Multi-omics Deciphers the Assembly Rules of the Human Skin Microbiome and Highlights Lipid-Mediated Niche Partitioning

Understanding the ecological assembly mechanisms of microbial communities is critical for deciphering host-microbiota interactions, however, such processes remain poorly characterized in cutaneous ecosystems. By profiling a non-industrialized rural cohort, this study deciphers the assembly rules governing the human skin microbiome and reveals an evolutionarily conserved core microbiota structured by niche selection. Microbial -diversity peaks when C. acnes and M. osloensis reach equilibrium, supporting the Intermediate Disturbance Hypothesis. Host lipids, rather than aqueous compounds, emerged as the primary drivers of microbial niche partitioning. We further demonstrate that C. acnes and Malassezia restricta function as core metabolic engineers, expressing diverse lipases that hydrolyze triglycerides (TGs) into free fatty acids (FFAs), thereby maintaining skin surface lipid homeostasis ([~]85% TG + FFA). Notably, virtually all skin surface FFAs are microbially derived and function as "public goods", enabling cross-feeding that supports auxotrophic members and fosters mutualistic interactions. Importantly, in vitro coculture experiments confirm that C. acnes establish a survival niche for M. restricta. Our findings support a paradigm shift from a taxonomic to a functional understanding of the skin ecosystem, underscoring microbial lipid metabolism as a central orchestrator of ecological stability and a promising target for therapeutic intervention. O_FIG O_LINKSMALLFIG WIDTH=182 HEIGHT=200 SRC="FIGDIR/small/674196v1_ufig1.gif" ALT="Figure 1"> View larger version (62K): org.highwire.dtl.DTLVardef@1274fa5org.highwire.dtl.DTLVardef@1ddfa07org.highwire.dtl.DTLVardef@49f917org.highwire.dtl.DTLVardef@807a14_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGRAPHIC ABSTRACTC_FLOATNO C_FIG

microbiology↗

bioRxiv2025

A Comprehensive Reference Catalog of Human Skin DNA Virome Reveals Novel Viral Diversity and Microenvironmental Influences

IntroductionHuman skin serves as a dynamic habitat for a diverse microbiome, including a complex array of viruses whose diversity and roles are not fully understood. ObjectivesThis study aims to enhance our understanding of this skin viral diversity through the construction of a detailed, non-redundant DNA viral reference catalog. MethodsA total of 2,760 skin metagenomes from six published skin studies were collected. A skin virome catalog was constructed using methods independent of reference databases. Viral characteristics were identified through cross-cohort meta-analysis and used to characterize viral features across different skin environments. ResultsWe identified 20,927 viral sequences, which clustered into 2,873 viral operational taxonomic units (vOTUs). Among these, 2,610 represent previously unrecorded viral sequences, uncovering a substantial breadth of viral diversity on human skin. The results also highlight significant differences in viral communities that are associated with varying skin microenvironments. The oily skin is enriched in Papillomaviridae; the dry skin area is enriched in Autographiviridae, Inoviridae and Mitoviridae; and the moist skin is enriched in Herelleviridae, indicating the adaptive nature of viruses. We also investigated the relationship between bacteriophages and bacteria on the skin surface. We found that skin bacteria such as Pseudomonas, Klebsiella, and Staphylococcus are infected by phages from the class Caudoviricetes. ConclusionThis comprehensive skin DNA viral catalog significantly advances our understanding of the viromes role within the skin ecosystem. The findings highlight the adaptive nature of viruses to different skin microenvironments and their interactions with resident bacteria. This catalog serves as a valuable resource for further epidemiological and therapeutic research, potentially leading to better management and treatment of skin conditions influenced by the skins virome.

microbiology↗

bioRxiv2023

Cockayne syndrome patient iPSC-derived brain organoids and neurospheres show early transcriptional dysregulation of biological processes associated with brain development and metabolism.

Cockayne syndrome is a rare hereditary autosomal recessive disorder characterized by diverse neurological afflictions. However, little is known about the cerebral development in CS patients. We generated neurospheres and cerebral organoids utilizing Cockayne Syndrome B Protein (CSB) deficient induced pluripotent stem cells derived from two patients with distinct severity levels of CS and healthy controls. The transcriptome of both developmental timepoints was explored using RNA-Seq and bioinformatic analysis to identify dysregulated biological processes common to both CS patients in comparison to control. CSB-deficient neurospheres displayed upregulation of VEGFA-VEGFR2 signaling pathway, Vesicle-Mediated transport and head development. CSB-deficient cerebral organoids exhibited downregulation of brain development, neuron projection development and synaptic signalling. We further identified upregulation of Steroid Biosynthesis as common to both timepoints, in particular upregulation of the Cholesterol Biosynthesis branch. Our results provide insights into the neurodevelopmental dysregulation in CS patients and strengthen the theory, that CS is not only a neurodegenerative, but also a neurodevelopmental disorder.

neuroscience↗

bioRxiv2021

Duesselpore: a full-stack local web server for rapid and simple analysis of Oxford Nanopore Sequencing data

Genome-wide analysis of transcriptomes offers extensive insights into the molecular mechanisms underlying the physiology of all known species and discover those that are still hidden. Oxford Nanopore Technologies (ONT) has recently been developed as a fast, miniaturized, portable and a cost effective alternative to Next Generation Sequencing. However, RNA-seq data analysis software that exploit ONT portability and allows scientists to easily analyze ONT data everywhere without bioinformatic expertise is not widely available. We developed Duesselpore, an easy-to-follow deep sequencing workflow that runs as a local webserver and allows the analysis of ONT data everywhere without requiring additional bioinformatic tools or internet connection. Duesselpore output includes differentially expressed genes and further downstream analyses, such as variance heatmap, disease and gene ontology plots, gene concept network plots and exports customized pathways for different cellular processes. We validated Duesselpore by analyzing the transcriptomic changes induced by PCB126, a dioxin-like PCB and a potent aryl hydrocarbon receptor (AhR) agonist in human HaCaT keratinocytes, a well characterized model system. Duesselpore was specifically developed to analyze ONT data but we also implemented NGS data analysis. Duesselpore is compatible with Microsoft and Mac operating systems, allows convenient, reliable and cost-effective analysis of ONT and NGS data.

bioinformatics↗

bioRxiv2021

Ultraviolet light-induced collagen degradation inhibits melanoma invasion

Ultraviolet radiation (UVR) increases the incidence of cutaneous melanoma1-4. The ageing, sun-exposed dermis accumulates UVR damage5, and older patients develop more melanomas at UVR-exposed sites4,6,7. As fibroblasts are functionally heterogeneous and play key roles in the stromal contribution to cancer8,9, we asked whether UVR modifies dermal fibroblast function. Here we confirmed the expression of collagen-cleaving matrix metalloprotein-1 (MMP1) by UVR-damaged fibroblasts was persistently upregulated to reduce local levels of collagen 1 (COL1A1), and found dermal COL1A1 degradation by MMP1 decreased melanoma invasion. Conversely, we show inhibiting extracellular matrix degradation and MMP1 expression restored melanoma invasion to UVR damaged dermis. We confirmed in vitro findings in a cohort of primary cutaneous melanomas of aged humans, showing more cancer cells invade as single cells at the invasive front of melanomas expressing and depositing more collagen. We found collagen and single melanoma cell invasion are robust predictors of poor melanoma-specific survival. These data indicate melanomas arising over UVR-damaged, collagen-poor skin of the elderly are less invasive, and this reduced invasion improves survival. Consequently, although UVR increases tumour incidence, it delays primary melanoma invasion by degrading collagen. However, we show melanoma-associated fibroblasts can restore invasion in low-collagen primary tumours by increasing collagen synthesis. Finally, we demonstrate high COL1A1 gene expression is a biomarker of poor outcome across a broad range of primary cancers.

cancer biology↗

bioRxiv2021

Fast but not furious: a streamlined selection method for genome edited cells

In the last decade, Transcription Activator-Like Effector Nucleases (TALEN) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) based genome engineering have revolutionized our approach to biology. Due to their high efficiency and ease of use, the development of custom knock-out and knock-in animal or cell models is now within reach for almost every laboratory. Nonetheless, the generation of genetically modified cells often requires a selection step, usually achieved by antibiotics or fluorescent markers. The choice of the selection marker is based on the available laboratory resources, such as cell types, and parameters like time and cost should also be taken into consideration. Here, we present a new and fast strategy called MAGECS (magnetic-activated genome edited cell sorting), to select genetically modified cells based on the ability to magnetically sort surface antigens (i.e. tCD19) present in Cas9 positive cells. By using MAGECS, we successfully generated and isolated genetically modified human induced pluripotent stem cells (hiPSCs), primary human fibroblasts, SH-SY5Y neuroblast-like cells, HaCaT and HEK293T cells. Our strategy expands the genome editing toolbox by offering a fast, cheap, and an easy to use alternative to the available selection methods.

genomics↗