Cell Fate and Metabolism
We investigate the mechanisms driving the direct reprogramming of differentiated mouse and human cells into functional neurons, aiming at a comprehensive understanding of the conversion process with the final aim of further improvement of purity and quality of the induced neurons.
Leveraging state-of-the-art technologies — including single-cell multiomics, proteomics, metabolomics and high-content imaging — we aim to understand the extent to which the identity of differentiated cells can be manipulated to generate new neurons that are functionally and molecularly similar to those present in the adult healthy brain.
About our Research
We have shown that mitochondrial activity plays a crucial role in the direct neuronal reprogramming of both mouse (Gascon et al., 2016; Russo et al., 2020) and human astrocytes (Sonsalla, Malpartida et al., 2024). Beyond their role in ATP production, mitochondria contribute to redox homeostasis by regenerating NADH to NAD+. Notably, treatment with nicotinamide riboside (NR), a precursor of NAD+, enhances the generation of induced neurons (iNeurons) from human astrocytes while reducing aggregate formation in iNs.
Here, we investigate whether NR-mediated improvements in neuronal conversion are solely due to its redox function or also involve NAD+-dependent enzymes, such as nuclear sirtuins.
A surprising findings of our previous work is that the mitochondrial proteome differs between astrocytes and neurons, and successfully induced neurons downregulate astrocyte-enriched mitochondrial proteins and upregulate neuron-enriched mitochondrial proteins (Russo et al., 2020). More recently, we identified the unfolded protein response (UPR) as a major hurdle in the direct neuronal reprogramming of human astrocytes (Sonsalla, Malpartida et al., 2024). Given that UPR primarily occurs in the endoplasmic reticulum (ER), it is plausible that the ER proteome also differs between astrocytes and neurons.
To build on these findings, we seek to determine the extent to which organelles vary across cell types and how their proteome—and consequently their function—must change during astrocyte-to-neuron reprogramming. Here, we aim to characterize the proteome of various organelles and track their dynamics during neuronal conversion to assess whether these changes act as additional roadblocks in the process.
Ascl1 and Neurogenin2 are proneural transcription factors with pioneering activity, enabling them to access closed chromatin and initiate a transcriptional program that drives neuronal identity. However, how different cellular contexts influence this conversion process remains poorly understood (Kempf, Knelles, Hersbach et al., 2021).
Here, we aim to compare the mechanisms triggered by the same reprogramming factor in different starting cell types (e.g., astroglial cells isolated from distinct CNS regions) and to identify both universal and cell-specific principles that govern direct neuronal reprogramming.
In vitro model systems are valuable for studying the molecular mechanisms underlying processes like direct reprogramming. However, they often lack the complexity of in vivo environments, such as the brain, particularly its three-dimensional architecture.
Here, we aim to establish a novel model system that integrates the advantages of in vitro models—such as ease of handling, scalability, and compatibility with imaging and analysis—with key aspects of a 3D environment, including spatial organization and cellular diversity. This system will allow us to assess how these factors influence direct neuronal reprogramming.
Over the years, we have identified genetic (e.g., REST), metabolic (e.g., ROS), and post-translational (e.g., UPR) barriers that hinder direct neuronal reprogramming. Beyond conceptual understanding of the conversion process, we are also performing screens with repruposing drugs to enhance the conversion process using high-content screening approaches and to investigate the molecular mechanisms underlying their effects.
Team Members
Publications
Maddhesiya, P. ; Lepko, T. ; Steiner‑Mezzardi, A. ; Schneider, J. ; Schwarz, V. ; Merl-Pham, J. ; Berger, F. ; Hauck, S.M. ; Ronfani, L. ; Bianchi, M.E. ; Simon, T. ; Krontira, A. ; Masserdotti, G. ; Götz, M. ; Ninkovic, J.
Hmgb2 improves astrocyte to neuron conversion by increasing the chromatin accessibility of genes associated with neuronal maturation in a proneuronal factor-dependent manner.Natarajan, P. ; Koupourtidou, C. ; de Resseguier, T. ; Thorwirth, M. ; Bocchi, R. ; Fischer-Sternjak, J. ; Gleiss, S. ; Rodrigues, D. ; Myoga, M.H. ; Ninkovic, J. ; Masserdotti, G. ; Götz, M.
Single cell deletion of the transcription factors Trps1 and Sox9 in astrocytes reveals novel functions in the adult cerebral cortex.Puglisi, M. ; Lao, C.L. ; Wani, G. ; Masserdotti, G. ; Bocchi, R. ; Götz, M.
Comparing viral vectors and fate mapping approaches for astrocyte-to-neuron reprogramming in the injured mouse cerebral cortex.Masserdotti, G.
Late onset Alzheimer's disease: Modeling disease hallmarks via in vitro 3D iNeuron cultures.Pereira, A. ; Diwakar, S.J. ; Masserdotti, G. ; Beşkardeş, S. ; Simon, T. ; So, Y. ; Martín-Loarte, L. ; Bergemann, F. ; Vasan, L. ; Schauer, T. ; Danese, A. ; Bocchi, R. ; Colomé-Tatché, M. ; Schuurmans, C. ; Philpott, A. ; Straub, T. ; Bonev, B. ; Götz, M.
Direct neuronal reprogramming of mouse astrocytes is associated with multiscale epigenome remodeling and requires Yy1.Sonsalla, G. ; Malpartida, A.B. ; Riedemann, T. ; Gusic, M. ; Rusha, E. ; Bulli, G. ; Najas, S. ; Janjic, A. ; Hersbach, B.A. ; Smialowski, P. ; Drukker, M. ; Enard, W. ; Prehn, J.H.M. ; Prokisch, H. ; Götz, M. ; Masserdotti, G.
Direct neuronal reprogramming of NDUFS4 patient cells identifies the unfolded protein response as a novel general reprogramming hurdle.Sirko, S. ; Schichor, C. ; Della Vecchia, P. ; Metzger, F. ; Sonsalla, G. ; Simon, T. ; Bürkle, M. ; Kalpazidou, S. ; Ninkovic, J. ; Masserdotti, G. ; Sauniere, J.F. ; Iacobelli, V. ; Iacobelli, S. ; Delbridge, C. ; Hauck, S.M. ; Tonn, J.C. ; Götz, M.
Injury-specific factors in the cerebrospinal fluid regulate astrocyte plasticity in the human brain.Gong, S. ; Sun, N. ; Meyer, L.S. ; Tetti, M. ; Koupourtidou, C. ; Krebs, S. ; Masserdotti, G. ; Blum, H. ; Rainey, W.E. ; Reincke, M. ; Walch, A.K. ; Williams, T.A.
Primary aldosteronism: Spatial multi-omics mapping of genotype-dependent heterogeneity and tumor expansion of aldosterone-producing adenomas.Hersbach, B.A. ; Fischer, D.S. ; Masserdotti, G. ; Deeksha ; Mojžišová, K. ; Waltzhöni, T. ; Rodriguez-Terro, D. ; Heinig, M. ; Theis, F.J. ; Götz, M. ; Stricker, S.H.
Probing cell identity hierarchies by fate titration and collision during direct reprogramming.Hersbach, B.A. ; Simon, T. ; Masserdotti, G.
Isolation and direct neuronal reprogramming of mouse astrocytes.Giehrl-Schwab, J. ; Giesert, F. ; Rauser, B. ; Lao, C.L. ; Hembach, S. ; Lefort, S. ; Ibarra Del Rio, I.A. ; Koupourtidou, C. ; Luecken, M. ; Truong, D.-J.J. ; Fischer-Sternjak, J. ; Masserdotti, G. ; Prakash, N. ; Ninkovic, J. ; Hölter, S.M. ; Vogt Weisenhorn, D.M. ; Theis, F.J. ; Götz, M. ; Wurst, W.
Parkinson's disease motor symptoms rescue by CRISPRa-reprogramming astrocytes into GABAergic neurons.Bocchi, R. ; Masserdotti, G. ; Götz, M.
Direct neuronal reprogramming: Fast forward from new concepts toward therapeutic approaches.Natarajan, P. ; Masserdotti, G. ; Götz, M. ; Bocchi, R.
Unravelling the fate determinants of astrocytic identity and their impact in direct neuronal reprogramming.Kempf, J. ; Knelles, K. ; Hersbach, B.A. ; Petrik, D. ; Riedemann, T. ; Bednarova, V. ; Janjic, A. ; Simon-Ebert, T. ; Enard, W. ; Smialowski, P. ; Götz, M. ; Masserdotti, G.
Heterogeneity of neurons reprogrammed from spinal cord astrocytes by the proneural factors Ascl1 and Neurogenin2.Russo, G.L. ; Sonsalla, G. ; Natarajan, P. ; Breunig, C. ; Bulli, G. ; Merl-Pham, J. ; Schmitt, S. ; Giehrl-Schwab, J. ; Giesert, F. ; Jastroch, M. ; Zischka, H. ; Wurst, W. ; Stricker, S.H. ; Hauck, S.M. ; Masserdotti, G. ; Götz, M.
CRISPR-mediated induction of neuron-enriched mitochondrial proteins boosts direct glia-to-neuron conversion.Masserdotti, G. ; Götz, M.
Turning connective tissue into neurons for 10 years.Gascón, S. ; Masserdotti, G. ; Russo, G.L. ; Götz, M.
Direct neuronal reprogramming: Achievements, hurdles, and new roads to success.Masserdotti, G. ; Gascón, S. ; Götz, M.
Direct neuronal reprogramming: Learning from and for development.Gascón, S. ; Murenu, E. ; Masserdotti, G. ; Ortega, F. ; Russo, G.L. ; Petrik, D. ; Deshpande, A. ; Heinrich, C. ; Karow, M. ; Robertson, S.P. ; Schroeder, T. ; Beckers, J. ; Irmler, M. ; Berndt, C. ; Friedmann Angeli, J.P.F. ; Conrad, M. ; Berninger, B. ; Götz, M.
Identification and successful negotiation of a metabolic checkpoint in direct neuronal repogramming.Masserdotti, G. ; Berninger, B.
Direct Reprogramming of Somatic Cells into Induced Neuronal Cells: Where We Are and Where We Want to Go.Masserdotti, G. ; Gillotin, S. ; Sutor, B. ; Drechsel, D. ; Irmler, M. ; Jørgensen, H.F. ; Sass, S. ; Theis, F.J. ; Beckers, J. ; Berninger, B. ; Guillemot, F. ; Götz, M.
Transcriptional mechanisms of proneural factors and REST in regulating neuronal reprogramming of astrocytes.Bergami, M. ; Masserdotti, G. ; Temprana, S.G. ; Motori, E. ; Eriksson, T.M. ; Göbel, J. ; Yang, S.M. ; Conzelmann, K.K. ; Schinder, A.F. ; Götz, M. ; Berninger, B.
A critical period for experience-dependent remodeling of adult-born neuron connectivity.Ninkovic, J. ; Steiner-Mezzadri, A. ; Jawerka, M. ; Akinci, U. ; Masserdotti, G. ; Petricca, S. ; Fischer, J. ; von Holst, A. ; Beckers, J. ; Lie, D.C. ; Petrik, D. ; Miller, E. ; Tang, J. ; Wu, J. ; Lefebvre, V. ; Demmers, J. ; Eisch, A. ; Metzger, D. ; Crabtree, G. ; Irmler, M. ; Poot, R. ; Götz, M.
The BAF complex interacts with Pax6 in adult neural progenitors to establish a neurogenic cross-regulatory transcriptional network.Ortega, F. ; Gascón, S. ; Masserdotti, G. ; Deshpande, A. ; Simon, C. ; Fischer, J. ; Dimou, L. ; Lie, D.C.C. ; Schroeder, T. ; Berninger, B.
Oligodendrogliogenic and neurogenic adult subependymal zone neural stem cells constitute distinct lineages and exhibit differential responsiveness to Wnt signalling.Karow, M. ; Sánchez, R. ; Schichor, C. ; Masserdotti, G. ; Ortega, F. ; Heinrich, C. ; Gascón, S. ; Khan, M.A. ; Lie, D.C. ; Dellavalle, A. ; Cossu, G. ; Goldbrunner, R. ; Götz, M. ; Berninger, B.
Reprogramming of pericyte-derived cells of the adult human brain into induced neuronal cells.Mu, L. ; Berti, L. ; Masserdotti, G. ; Covic, M. ; Michaelidis, T.M. ; Doberauer, K. ; Merz, K. ; Rehfeld, F. ; Haslinger, A. ; Wegner, M. ; Sock, E. ; Lefebvre, V. ; Couillard-Despres, S. ; Aigner, L. ; Berninger, B. ; Lie, D.C.
SoxC transcription factors are required for neuronal differentiation in adult hippocampal neurogenesis.Heinrich, C. ; Gascón, S. ; Masserdotti, G. ; Lepier, A. ; Sánchez, R. ; Simon-Ebert, T. ; Schroeder, T. ; Götz, M. ; Berninger, B.
Generation of subtype-specific neurons from postnatal astroglia of the mouse cerebral cortex.Heinrich, C. ; Blum, R. ; Gascón, S. ; Masserdotti, G. ; Tripathi, P. ; Sánchez, R. ; Tiedt, S. ; Schroeder, T. ; Götz, M. ; Berninger, B.
Directing astroglia from the cerebral cortex into subtype specific functional neurons.