scispace - formally typeset
Search or ask a question
Author

Kerstin Bartscherer

Bio: Kerstin Bartscherer is an academic researcher from Max Planck Society. The author has contributed to research in topics: Regeneration (biology) & Planarian. The author has an hindex of 19, co-authored 26 publications receiving 2812 citations. Previous affiliations of Kerstin Bartscherer include German Cancer Research Center & Heidelberg University.

Papers
More filters
Journal ArticleDOI
TL;DR: It is demonstrated that exosomes carry Wnts on their surface to induce Wnt signalling activity in target cells and an evolutionarily conserved functional role of extracellular vesicular transport of Wnt proteins is demonstrated.
Abstract: Wnt signalling has important roles during development and in many diseases As morphogens, hydrophobic Wnt proteins exert their function over a distance to induce patterning and cell differentiation decisions Recent studies have identified several factors that are required for the secretion of Wnt proteins; however, how Wnts travel in the extracellular space remains a largely unresolved question Here we show that Wnts are secreted on exosomes both during Drosophila development and in human cells We demonstrate that exosomes carry Wnts on their surface to induce Wnt signalling activity in target cells Together with the cargo receptor Evi/WIs, Wnts are transported through endosomal compartments onto exosomes, a process that requires the R-SNARE Ykt6 Our study demonstrates an evolutionarily conserved functional role of extracellular vesicular transport of Wnt proteins

817 citations

Journal ArticleDOI
05 May 2006-Cell
TL;DR: It is suggested that evi is the founding member of a gene family specifically required for Wg/Wnt secretion, which is evolutionarily conserved as depletion of its human homolog disrupts Wnt signaling in human cells.

548 citations

Journal ArticleDOI
TL;DR: Using a kinome-wide RNAi screen, it is shown that PPPSP phosphorylation requires the Drosophila Cyclin-dependent kinase (CDK) L63, and in Xenopus embryos, Cyclin Y is required in vivo for LRP6 phosphorylated, maternal Wnt signaling, and Wnt-dependent anteroposterior embryonic patterning.

244 citations

Journal ArticleDOI
TL;DR: This study provides evidence that planarian Wnts are major regulators of regeneration, and that they signal through β-catenin-dependent and -independent pathways.
Abstract: Planarians can regenerate a whole animal from only a small piece of their body, and have become an important model for stem cell biology. To identify regenerative processes dependent on Wnt growth factors in the planarian Schmidtea mediterranea ( Smed ), we analyzed RNAi phenotypes of Evi, a transmembrane protein specifically required for the secretion of Wnt ligands. We show that, during regeneration, Smed-evi loss-of-function prevents posterior identity, leading to two-headed planarians that resemble Smed -β -catenin1 RNAi animals. In addition, we observe regeneration defects of the nervous system that are not found after Smed -β -catenin1 RNAi. By systematic knockdown of all putative Smed Wnts in regenerating planarians, we identify Smed-WntP-1 and Smed-Wnt11-2 as the putative posterior organizers, and demonstrate that Smed-Wnt5 is a regulator of neuronal organization and growth. Thus, our study provides evidence that planarian Wnts are major regulators of regeneration, and that they signal through β-catenin-dependent and -independent pathways.

189 citations

Journal ArticleDOI
TL;DR: Why planarians are an exciting tool in the study of regeneration and its underlying stem cell biology in vivo is highlighted, and the potential promises and current limitations of this model organism for stem cell research and regenerative medicine are discussed.
Abstract: Planarian flatworms are an exception among bilaterians in that they possess a large pool of adult stem cells that enables them to promptly regenerate any part of their body, including the brain. Although known for two centuries for their remarkable regenerative capabilities, planarians have only recently emerged as an attractive model for studying regeneration and stem cell biology. This revival is due in part to the availability of a sequenced genome and the development of new technologies, such as RNA interference and next-generation sequencing, which facilitate studies of planarian regeneration at the molecular level. Here, we highlight why planarians are an exciting tool in the study of regeneration and its underlying stem cell biology in vivo, and discuss the potential promises and current limitations of this model organism for stem cell research and regenerative medicine.

155 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: This review focuses on the characterization of EVs and on currently proposed mechanisms for their formation, targeting, and function.
Abstract: Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, and RNA. Deficiencies in our knowledge of the molecular mechanisms for EV formation and lack of methods to interfere with the packaging of cargo or with vesicle release, however, still hamper identification of their physiological relevance in vivo. In this review, we focus on the characterization of EVs and on currently proposed mechanisms for their formation, targeting, and function.

6,141 citations

Journal ArticleDOI
Clotilde Théry1, Kenneth W. Witwer2, Elena Aikawa3, María José Alcaraz4  +414 moreInstitutions (209)
TL;DR: The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities, and a checklist is provided with summaries of key points.
Abstract: The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points.

5,988 citations

Journal ArticleDOI
Hans Clevers1
03 Nov 2006-Cell
TL;DR: A remarkable interdisciplinary effort has unraveled the WNT (Wingless and INT-1) signal transduction cascade over the last two decades, finding that Germline mutations in the Wnt pathway cause several hereditary diseases, and somatic mutations are associated with cancer of the intestine and a variety of other tissues.

5,042 citations

Journal ArticleDOI
08 Jun 2012-Cell
TL;DR: An update of the core Wnt/β-catenin signaling pathway is provided, how its various components contribute to disease, and outstanding questions to be addressed in the future are discussed.

4,561 citations

Journal ArticleDOI
TL;DR: Extracellular vesicles are now considered as an additional mechanism for intercellular communication, allowing cells to exchange proteins, lipids and genetic material.
Abstract: Extracellular vesicles are a heterogeneous group of cell-derived membranous structures comprising exosomes and microvesicles, which originate from the endosomal system or which are shed from the plasma membrane, respectively They are present in biological fluids and are involved in multiple physiological and pathological processes Extracellular vesicles are now considered as an additional mechanism for intercellular communication, allowing cells to exchange proteins, lipids and genetic material Knowledge of the cellular processes that govern extracellular vesicle biology is essential to shed light on the physiological and pathological functions of these vesicles as well as on clinical applications involving their use and/or analysis However, in this expanding field, much remains unknown regarding the origin, biogenesis, secretion, targeting and fate of these vesicles

4,241 citations