@article{OelschlaegelWeissSadanSalpeteretal.2020, author = {Oelschlaegel, Diana and Weiss Sadan, Tommy and Salpeter, Seth and Krug, Sebastian and Blum, Galia and Schmitz, Werner and Schulze, Almut and Michl, Patrick}, title = {Cathepsin inhibition modulates metabolism and polarization of tumor-associated macrophages}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {9}, issn = {2072-6694}, doi = {10.3390/cancers12092579}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213040}, year = {2020}, abstract = {Stroma-infiltrating immune cells, such as tumor-associated macrophages (TAM), play an important role in regulating tumor progression and chemoresistance. These effects are mostly conveyed by secreted mediators, among them several cathepsin proteases. In addition, increasing evidence suggests that stroma-infiltrating immune cells are able to induce profound metabolic changes within the tumor microenvironment. In this study, we aimed to characterize the impact of cathepsins in maintaining the TAM phenotype in more detail. For this purpose, we investigated the molecular effects of pharmacological cathepsin inhibition on the viability and polarization of human primary macrophages as well as its metabolic consequences. Pharmacological inhibition of cathepsins B, L, and S using a novel inhibitor, GB111-NH\(_2\), led to changes in cellular recycling processes characterized by an increased expression of autophagy- and lysosome-associated marker genes and reduced adenosine triphosphate (ATP) content. Decreased cathepsin activity in primary macrophages further led to distinct changes in fatty acid metabolites associated with increased expression of key modulators of fatty acid metabolism, such as fatty acid synthase (FASN) and acid ceramidase (ASAH1). The altered fatty acid profile was associated with an increased synthesis of the pro-inflammatory prostaglandin PGE\(_2\), which correlated with the upregulation of numerous NF\(_k\)B-dependent pro-inflammatory mediators, including interleukin-1 (IL-1), interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), and tumor necrosis factor-alpha (TNFα). Our data indicate a novel link between cathepsin activity and metabolic reprogramming in macrophages, demonstrated by a profound impact on autophagy and fatty acid metabolism, which facilitates a pro-inflammatory micromilieu generally associated with enhanced tumor elimination. These results provide a strong rationale for therapeutic cathepsin inhibition to overcome the tumor-promoting effects of the immune-evasive tumor micromilieu.}, language = {en} } @article{PeckSchugZhangetal.2016, author = {Peck, Barrie and Schug, Zachary T. and Zhang, Qifeng and Dankworth, Beatrice and Jones, Dylan T. and Smethurst, Elizabeth and Patel, Rachana and Mason, Susan and Jian, Ming and Saunders, Rebecca and Howell, Michael and Mitter, Richard and Spencer-Dene, Bradley and Stamp, Gordon and McGarry, Lynn and James, Daniel and Shanks, Emma and Aboagye, Eric O. and Critchlow, Susan E. and Leung, Hing Y. and Harris, Adrian L. and Wakelam, Michael J. O. and Gottlieb, Eyal and Schulze, Almut}, title = {Inhibition of fatty acid desaturation is detrimental to cancer cell survival in metabolically compromised environments}, series = {Cancer \& Metabolism}, volume = {4}, journal = {Cancer \& Metabolism}, number = {6}, doi = {10.1186/s40170-016-0146-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145905}, year = {2016}, abstract = {Background Enhanced macromolecule biosynthesis is integral to growth and proliferation of cancer cells. Lipid biosynthesis has been predicted to be an essential process in cancer cells. However, it is unclear which enzymes within this pathway offer the best selectivity for cancer cells and could be suitable therapeutic targets. Results Using functional genomics, we identified stearoyl-CoA desaturase (SCD), an enzyme that controls synthesis of unsaturated fatty acids, as essential in breast and prostate cancer cells. SCD inhibition altered cellular lipid composition and impeded cell viability in the absence of exogenous lipids. SCD inhibition also altered cardiolipin composition, leading to the release of cytochrome C and induction of apoptosis. Furthermore, SCD was required for the generation of poly-unsaturated lipids in cancer cells grown in spheroid cultures, which resemble those found in tumour tissue. We also found that SCD mRNA and protein expression is elevated in human breast cancers and predicts poor survival in high-grade tumours. Finally, silencing of SCD in prostate orthografts efficiently blocked tumour growth and significantly increased animal survival. Conclusions Our data implicate lipid desaturation as an essential process for cancer cell survival and suggest that targeting SCD could efficiently limit tumour expansion, especially under the metabolically compromised conditions of the tumour microenvironment.}, language = {en} } @article{PeixotoJanakiRamanSchlickeretal.2021, author = {Peixoto, Joana and Janaki-Raman, Sudha and Schlicker, Lisa and Schmitz, Werner and Walz, Susanne and Winkelkotte, Alina M. and Herold-Mende, Christel and Soares, Paula and Schulze, Almut and Lima, Jorge}, title = {Integrated metabolomics and transcriptomics analysis of monolayer and neurospheres from established glioblastoma cell lines}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {6}, issn = {2072-6694}, doi = {10.3390/cancers13061327}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234110}, year = {2021}, abstract = {Altered metabolic processes contribute to carcinogenesis by modulating proliferation, survival and differentiation. Tumours are composed of different cell populations, with cancer stem-like cells being one of the most prominent examples. This specific pool of cells is thought to be responsible for cancer growth and recurrence and plays a particularly relevant role in glioblastoma (GBM), the most lethal form of primary brain tumours. Here, we have analysed the transcriptome and metabolome of an established GBM cell line (U87) and a patient-derived GBM stem-like cell line (NCH644) exposed to neurosphere or monolayer culture conditions. By integrating transcriptome and metabolome data, we identified key metabolic pathways and gene signatures that are associated with stem-like and differentiated states in GBM cells, and demonstrated that neurospheres and monolayer cells differ substantially in their metabolism and gene regulation. Furthermore, arginine biosynthesis was identified as the most significantly regulated pathway in neurospheres, although individual nodes of this pathway were distinctly regulated in the two cellular systems. Neurosphere conditions, as opposed to monolayer conditions, cause a transcriptomic and metabolic rewiring that may be crucial for the regulation of stem-like features, where arginine biosynthesis may be a key metabolic pathway. Additionally, TCGA data from GBM patients showed significant regulation of specific components of the arginine biosynthesis pathway, providing further evidence for the importance of this metabolic pathway in GBM.}, language = {en} } @article{SchwarzLukassenBhandareetal.2022, author = {Schwarz, Jessica Denise and Lukassen, S{\"o}ren and Bhandare, Pranjali and Eing, Lorenz and Snaebj{\"o}rnsson, Marteinn Thor and Garc{\´i}a, Yiliam Cruz and Kisker, Jan Philipp and Schulze, Almut and Wolf, Elmar}, title = {The glycolytic enzyme ALDOA and the exon junction complex protein RBM8A are regulators of ribosomal biogenesis}, series = {Frontiers in Cell and Developmental Biology}, volume = {10}, journal = {Frontiers in Cell and Developmental Biology}, issn = {2296-634X}, doi = {10.3389/fcell.2022.954358}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290875}, year = {2022}, abstract = {Cellular growth is a fundamental process of life and must be precisely controlled in multicellular organisms. Growth is crucially controlled by the number of functional ribosomes available in cells. The production of new ribosomes depends critically on the activity of RNA polymerase (RNAP) II in addition to the activity of RNAP I and III, which produce ribosomal RNAs. Indeed, the expression of both, ribosomal proteins and proteins required for ribosome assembly (ribosomal biogenesis factors), is considered rate-limiting for ribosome synthesis. Here, we used genetic screening to identify novel transcriptional regulators of cell growth genes by fusing promoters from a ribosomal protein gene (Rpl18) and from a ribosomal biogenesis factor (Fbl) with fluorescent protein genes (RFP, GFP) as reporters. Subsequently, both reporters were stably integrated into immortalized mouse fibroblasts, which were then transduced with a genome-wide sgRNA-CRISPR knockout library. Subsequently, cells with altered reporter activity were isolated by FACS and the causative sgRNAs were identified. Interestingly, we identified two novel regulators of growth genes. Firstly, the exon junction complex protein RBM8A controls transcript levels of the intronless reporters used here. By acute depletion of RBM8A protein using the auxin degron system combined with the genome-wide analysis of nascent transcription, we showed that RBM8A is an important global regulator of ribosomal protein transcripts. Secondly, we unexpectedly observed that the glycolytic enzyme aldolase A (ALDOA) regulates the expression of ribosomal biogenesis factors. Consistent with published observations that a fraction of this protein is located in the nucleus, this may be a mechanism linking transcription of growth genes to metabolic processes and possibly to metabolite availability.}, language = {en} } @article{VollmuthSchlickerGuoetal.2022, author = {Vollmuth, Nadine and Schlicker, Lisa and Guo, Yongxia and Hovhannisyan, Pargev and Janaki-Raman, Sudha and Kurmasheva, Naziia and Schmitz, Werner and Schulze, Almut and Stelzner, Kathrin and Rajeeve, Karthika and Rudel, Thomas}, title = {c-Myc plays a key role in IFN-γ-induced persistence of Chlamydia trachomatis}, series = {eLife}, volume = {11}, journal = {eLife}, doi = {10.7554/eLife.76721}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301385}, year = {2022}, abstract = {Chlamydia trachomatis (Ctr) can persist over extended times within their host cell and thereby establish chronic infections. One of the major inducers of chlamydial persistence is interferon-gamma (IFN-γ) released by immune cells as a mechanism of immune defence. IFN-γ activates the catabolic depletion of L-tryptophan (Trp) via indoleamine-2,3-dioxygenase (IDO), resulting in persistent Ctr. Here, we show that IFN-γ induces the downregulation of c-Myc, the key regulator of host cell metabolism, in a STAT1-dependent manner. Expression of c-Myc rescued Ctr from IFN-γ-induced persistence in cell lines and human fallopian tube organoids. Trp concentrations control c-Myc levels most likely via the PI3K-GSK3β axis. Unbiased metabolic analysis revealed that Ctr infection reprograms the host cell tricarboxylic acid (TCA) cycle to support pyrimidine biosynthesis. Addition of TCA cycle intermediates or pyrimidine/purine nucleosides to infected cells rescued Ctr from IFN-γ-induced persistence. Thus, our results challenge the longstanding hypothesis of Trp depletion through IDO as the major mechanism of IFN-γ-induced metabolic immune defence and significantly extends the understanding of the role of IFN-γ as a broad modulator of host cell metabolism.}, language = {en} }