1
|
Merk DJ, Zhou P, Cohen SM, Pazyra-Murphy MF, Hwang GH, Rehm KJ, Alfaro J, Reid CM, Zhao X, Park E, Xu PX, Chan JA, Eck MJ, Nazemi KJ, Harwell CC, Segal RA. The Eya1 Phosphatase Mediates Shh-Driven Symmetric Cell Division of Cerebellar Granule Cell Precursors. Dev Neurosci 2021; 42:170-186. [PMID: 33472197 DOI: 10.1159/000512976] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 11/10/2020] [Indexed: 12/14/2022] Open
Abstract
During neural development, stem and precursor cells can divide either symmetrically or asymmetrically. The transition between symmetric and asymmetric cell divisions is a major determinant of precursor cell expansion and neural differentiation, but the underlying mechanisms that regulate this transition are not well understood. Here, we identify the Sonic hedgehog (Shh) pathway as a critical determinant regulating the mode of division of cerebellar granule cell precursors (GCPs). Using partial gain and loss of function mutations within the Shh pathway, we show that pathway activation determines spindle orientation of GCPs, and that mitotic spindle orientation correlates with the mode of division. Mechanistically, we show that the phosphatase Eya1 is essential for implementing Shh-dependent GCP spindle orientation. We identify atypical protein kinase C (aPKC) as a direct target of Eya1 activity and show that Eya1 dephosphorylates a critical threonine (T410) in the activation loop. Thus, Eya1 inactivates aPKC, resulting in reduced phosphorylation of Numb and other components that regulate the mode of division. This Eya1-dependent cascade is critical in linking spindle orientation, cell cycle exit and terminal differentiation. Together these findings demonstrate that a Shh-Eya1 regulatory axis selectively promotes symmetric cell divisions during cerebellar development by coordinating spindle orientation and cell fate determinants.
Collapse
Affiliation(s)
- Daniel J Merk
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology & Interdisciplinary Neuro-Oncology, University Hospital Tübingen, Hertie Institute for Clinical Brain Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Pengcheng Zhou
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Samuel M Cohen
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Maria F Pazyra-Murphy
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Grace H Hwang
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Kristina J Rehm
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Jose Alfaro
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Christopher M Reid
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Xuesong Zhao
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Eunyoung Park
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Pin-Xian Xu
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York, USA
| | - Jennifer A Chan
- Arnie Charbonneau Cancer Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Michael J Eck
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Kellie J Nazemi
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA.,Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, USA
| | - Corey C Harwell
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA,
| | - Rosalind A Segal
- Department of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.,Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
2
|
Rehm KJ, Taylor AL, Pulver SR, Marder E. Spectral analyses reveal the presence of adult-like activity in the embryonic stomatogastric motor patterns of the lobster, Homarus americanus. J Neurophysiol 2008; 99:3104-22. [PMID: 18367701 DOI: 10.1152/jn.00042.2008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The stomatogastric nervous system (STNS) of the embryonic lobster is rhythmically active prior to hatching, before the network is needed for feeding. In the adult lobster, two rhythms are typically observed: the slow gastric mill rhythm and the more rapid pyloric rhythm. In the embryo, rhythmic activity in both embryonic gastric mill and pyloric neurons occurs at a similar frequency, which is slightly slower than the adult pyloric frequency. However, embryonic motor patterns are highly irregular, making traditional burst quantification difficult. Consequently, we used spectral analysis to analyze long stretches of simultaneous recordings from muscles innervated by gastric and pyloric neurons in the embryo. This analysis revealed that embryonic gastric mill neurons intermittently produced pauses and periods of slower activity not seen in the recordings of the output from embryonic pyloric neurons. The slow activity in the embryonic gastric mill neurons increased in response to the exogenous application of Cancer borealis tachykinin-related peptide 1a (CabTRP), a modulatory peptide that appears in the inputs to the stomatogastric ganglion (STG) late in larval development. These results suggest that the STG network can express adult-like rhythmic behavior before fully differentiated adult motor patterns are observed, and that the maturation of the neuromodulatory inputs is likely to play a role in the eventual establishment of the adult motor patterns.
Collapse
Affiliation(s)
- Kristina J Rehm
- Volen Center, Brandeis University, Waltham, MA 02454-9110, USA
| | | | | | | |
Collapse
|
3
|
Cape SS, Rehm KJ, Ma M, Marder E, Li L. Mass spectral comparison of the neuropeptide complement of the stomatogastric ganglion and brain in the adult and embryonic lobster, Homarus americanus. J Neurochem 2007; 105:690-702. [PMID: 18088365 DOI: 10.1111/j.1471-4159.2007.05154.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neuropeptides in the stomatogastric ganglion (STG) and the brain of adult and late embryonic Homarus americanus were compared using a multi-faceted mass spectral strategy. Overall, 29 neuropeptides from 10 families were identified in the brain and/or the STG of the lobster. Many of these neuropeptides are reported for the first time in the embryonic lobster. Neuropeptide extraction followed by liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry enabled confident identification of 24 previously characterized peptides in the adult brain and 13 peptides in the embryonic brain. Two novel peptides (QDLDHVFLRFa and GPPSLRLRFa) were de novo sequenced. In addition, a comparison of adult to embryonic brains revealed the presence of an incompletely processed form of Cancer borealis tachykinin-related peptide 1a (CabTRP 1a, APSGFLGMRG) only in the embryonic brain. A comparison of adult to embryonic STGs revealed that QDLDHVFLRFa was present in the embryonic STG but absent in the adult STG, and CabTRP 1a exhibited the opposite trend. Relative quantification of neuropeptides in the STG revealed that three orcokinin family peptides (NFDEIDRSGFGF, NFDEIDRSGFGFV, and NFDEIDRSGFGFN), a B-type allatostatin (STNWSSLRSAWa), and an orcomyotropin-related peptide (FDAFTTGFGHS) exhibited higher signal intensities in the adult relative to the embryonic STG. RFamide (Arg-Phe-amide) family peptide (DTSTPALRLRFa), [Val(1)]SIFamide (VYRKPPFNGSIFa), and orcokinin-related peptide (VYGPRDIANLY) were more intense in the embryonic STG spectra than in the adult STG spectra. Collectively, this study expands our current knowledge of the H. americanus neuropeptidome and highlights some intriguing expression differences that occur during development.
Collapse
Affiliation(s)
- Stephanie S Cape
- School of Pharmacy and Department of Chemistry, University of Wisconsin, Madison, WI 53705-2222, USA
| | | | | | | | | |
Collapse
|