@article{StojanovićFuchsFiedleretal.2020,
  author    = {Stojanović, Stevan D. and Fuchs, Maximilian and Fiedler, Jan and Xiao, Ke and Meinecke, Anna and Just, Annette and Pich, Andreas and Thum, Thomas and Kunz, Meik},
  title     = {Comprehensive bioinformatics identifies key microRNA players in ATG7-deficient lung fibroblasts},
  series = {International Journal of Molecular Sciences},
  volume    = {21},
  journal   = {International Journal of Molecular Sciences},
  number    = {11},
  issn      = {1422-0067},
  doi       = {10.3390/ijms21114126},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285181},
  year      = {2020},
  abstract  = {Background: Deficient autophagy has been recently implicated as a driver of pulmonary fibrosis, yet bioinformatics approaches to study this cellular process are lacking. Autophagy-related 5 and 7 (ATG5/ATG7) are critical elements of macro-autophagy. However, an alternative ATG5/ATG7-independent macro-autophagy pathway was recently discovered, its regulation being unknown. Using a bioinformatics proteome profiling analysis of ATG7-deficient human fibroblasts, we aimed to identify key microRNA (miR) regulators in autophagy. Method: We have generated ATG7-knockout MRC-5 fibroblasts and performed mass spectrometry to generate a large-scale proteomics dataset. We further quantified the interactions between various proteins combining bioinformatics molecular network reconstruction and functional enrichment analysis. The predicted key regulatory miRs were validated via quantitative polymerase chain reaction. Results: The functional enrichment analysis of the 26 deregulated proteins showed decreased cellular trafficking, increased mitophagy and senescence as the major overarching processes in ATG7-deficient lung fibroblasts. The 26 proteins reconstitute a protein interactome of 46 nodes and miR-regulated interactome of 834 nodes. The miR network shows three functional cluster modules around miR-16-5p, miR-17-5p and let-7a-5p related to multiple deregulated proteins. Confirming these results in a biological setting, serially passaged wild-type and autophagy-deficient fibroblasts displayed senescence-dependent expression profiles of miR-16-5p and miR-17-5p. Conclusions: We have developed a bioinformatics proteome profiling approach that successfully identifies biologically relevant miR regulators from a proteomics dataset of the ATG-7-deficient milieu in lung fibroblasts, and thus may be used to elucidate key molecular players in complex fibrotic pathological processes. The approach is not limited to a specific cell-type and disease, thus highlighting its high relevance in proteome and non-coding RNA research.},
  language  = {en}
}
@article{JazbutyteFiedlerKneitzetal.2012,
  author    = {Jazbutyte, Virginija and Fiedler, Jan and Kneitz, Susanne and Galuppo, Paolo and Just, Annette and Holzmann, Angelika and Bauersachs, Johann and Thum, Thomas},
  title     = {MicroRNA-22 increases senescence and activates cardiac fibroblasts in the aging heart},
  series = {AGE},
  volume    = {35},
  journal   = {AGE},
  number    = {3},
  doi       = {10.1007/s11357-012-9407-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126745},
  pages     = {747-762},
  year      = {2012},
  abstract  = {MicroRNAs (miRs) are small non- coding RNA molecules controlling a plethora of biological processes such as development, cellular survival and senescence. We here determined miRs differentially regulated during cardiac postnatal development and aging. Cardiac function, morphology and miR expression profiles were determined in neonatal, 4 weeks, 6 months and 19 months old normotensive male healthy C57/Bl6N mice. MiR-22 was most prominently upregulated during cardiac aging. Cardiac expression of its bioinformatically predicted target mimecan (osteoglycin, OGN) was gradually decreased with advanced age. Luciferase reporter assays validated mimecan as a bona fide miR-22 target. Both, miR-22 and its target mimecan were co- expressed in cardiac fibroblasts and smooth muscle cells. Functionally, miR-22 overexpression induced cellular senescence and promoted migratory activity of cardiac fibroblasts. Small interference RNA-mediated silencing of mimecan in cardiac fibroblasts mimicked the miR-22-mediated effects. Rescue experiments revealed that the effects of miR-22 on cardiac fibroblasts were only partially mediated by mimecan. In conclusion, miR-22 upregulation in the aging heart contributed at least partly to accelerated cardiac fibroblast senescence and increased migratory activity. Our results suggest an involvement of miR-22 in age-associated cardiac changes, such as cardiac fibrosis.},
  language  = {en}
}
@phdthesis{Fiedler2010,
  author    = {Fiedler, Jan},
  title     = {Endothelial microRNA-24 contributes to capillary density in the infarcted heart},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49809},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Cardiovascular disease is the most common mortality risk in the industrialized world. Myocardial infarction (MI) results in the irreversible loss of cardiac muscle, triggering pathophysiological remodelling of the ventricle and development of heart failure. Insufficient myocardial capillary density within the surviving myocardium after MI has been identified as a critical event in this process, although the underlying molecular signalling pathways of cardiac angiogenesis are mechanistically not well understood. The discovery of microRNAs (miRNAs, miRs), small non-coding RNAs with 19-25 nucleotides in length, has introduced a new level of the regulation of cardiac signalling pathways. MiRNAs regulate gene expression post-transcriptionally by binding to their complementary target messenger RNAs (mRNAs) and represent promising therapeutic targets for gene therapy. Here, it is shown that cardiac miR-24 is primarily expressed in cardiac endothelial cells and upregulated following MI in mice and hypoxic conditions in vitro. Enhanced miR-24 expression induces endothelial cell apoptosis and impairs endothelial capillary network formation. These effects on endothelial cell biology are at least in part mediated through targeting of transcription factor GATA2, histone deacetylase H2A.X, p21-activated kinase PAK4 and Ras p21 protein activator RASA1. Mechanistically, target repression abolishes respective and secondary downstream signalling cascades. Here it is shown that endothelial GATA2 is an important mediator of cell cycle, apoptosis and angiogenesis at least in part by regulation of cytoprotective heme oxygenase 1 (HMOX1). Moreover, additional control of endothelial apoptosis is achieved by the direct miR-24 target PAK4. Its kinase function is essential for anti-apoptotic Bad phosphorylation in endothelial cells. In a mouse model of MI, blocking of endothelial miR-24 by systemic administration of a specific antagonist (antagomir) enhances capillary density in the infarcted heart and preserves cardiac function. The current findings indicate miR-24 to act as a critical regulator of endothelial cell apoptosis and angiogenesis. Modulation of miR-24 may be potentially a suitable strategy for therapeutic intervention in the setting of ischemic heart diseases.},
  subject      = {Herzinfarkt},
  language  = {en}
}