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Bunner S, Prince K, Srikrishna K, Pujadas EM, McCarthy AA, Kuklinski A, Jackson O, Pellegrino P, Jagtap S, Eweka I, Lawlor C, Eastin E, Yas G, Aiello J, LaPointe N, von Blucher IS, Hardy J, Chen J, Backman V, Janssen A, Packard M, Dorfman K, Almassalha L, Bahiru MS, Stephens AD. DNA density is a better indicator of a nuclear bleb than lamin B loss. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579152. [PMID: 38370828 PMCID: PMC10871186 DOI: 10.1101/2024.02.06.579152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Nuclear blebs are herniations of the nucleus that occur in diseased nuclei that cause nuclear rupture leading to cellular dysfunction. Chromatin and lamins are two of the major structural components of the nucleus that maintain its shape and function, but their relative roles in nuclear blebbing remain elusive. Lamin B is reported to be lost in blebs by qualitative data while quantitative studies reveal a spectrum of lamin B levels in nuclear blebs dependent on perturbation and cell type. Chromatin has been reported to be decreased or de-compacted in nuclear blebs, but again the data are not conclusive. To determine the composition of nuclear blebs, we compared the immunofluorescence intensity of lamin B and DNA in the main nucleus body and nuclear bleb across cell types and perturbations. Lamin B nuclear bleb levels varied drastically across MEF wild type and chromatin or lamins perturbations, HCT116 lamin B1-GFP imaging, and human disease model cells of progeria and prostate cancer. However, DNA concentration was consistently decreased to about half that of the main nucleus body across all measured conditions. Using Partial Wave Spectroscopic (PWS) microscopy to measure chromatin density in the nuclear bleb vs body we find similar results that DNA is consistently less dense in nuclear blebs. Thus, our data spanning many different cell types and perturbations supports that decreased DNA is a better marker of a nuclear bleb than lamin B levels that vary widely.
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Affiliation(s)
- Samantha Bunner
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Kelsey Prince
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Karan Srikrishna
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Emily Marie Pujadas
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- IBIS Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL 60208, USA
| | | | - Anna Kuklinski
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Olivia Jackson
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Pedro Pellegrino
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Shrushti Jagtap
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Imuetiyan Eweka
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Colman Lawlor
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Emma Eastin
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Griffin Yas
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Julianna Aiello
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Nathan LaPointe
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | | | - Jillian Hardy
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Jason Chen
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Anne Janssen
- School of Biological Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Mary Packard
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Katherine Dorfman
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
| | - Luay Almassalha
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Michael Seifu Bahiru
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, MA 01003, USA
| | - A. D. Stephens
- Biology department, University of Massachusetts Amherst, Amherst, MA. 01003, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
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Berg IK, Currey ML, Gupta S, Berrada Y, Nguyen BV, Pho M, Patteson AE, Schwarz JM, Banigan EJ, Stephens AD. Transcription inhibition suppresses nuclear blebbing and rupture independently of nuclear rigidity. J Cell Sci 2023; 136:jcs261547. [PMID: 37756607 PMCID: PMC10660790 DOI: 10.1242/jcs.261547] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
Chromatin plays an essential role in the nuclear mechanical response and determining nuclear shape, which maintain nuclear compartmentalization and function. However, major genomic functions, such as transcription activity, might also impact cell nuclear shape via blebbing and rupture through their effects on chromatin structure and dynamics. To test this idea, we inhibited transcription with several RNA polymerase II inhibitors in wild-type cells and perturbed cells that presented increased nuclear blebbing. Transcription inhibition suppressed nuclear blebbing for several cell types, nuclear perturbations and transcription inhibitors. Furthermore, transcription inhibition suppressed nuclear bleb formation, bleb stabilization and bleb-based nuclear ruptures. Interestingly, transcription inhibition did not alter the histone H3 lysine 9 (H3K9) modification state, nuclear rigidity, and actin compression and contraction, which typically control nuclear blebbing. Polymer simulations suggested that RNA polymerase II motor activity within chromatin could drive chromatin motions that deform the nuclear periphery. Our data provide evidence that transcription inhibition suppresses nuclear blebbing and rupture, in a manner separate and distinct from chromatin rigidity.
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Affiliation(s)
- Isabel K. Berg
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Marilena L. Currey
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Sarthak Gupta
- Department of Physics and BioInspired Syracuse, Syracuse University, Syracuse, NY 13244, USA
| | - Yasmin Berrada
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Bao V. Nguyen
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Mai Pho
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Alison E. Patteson
- Department of Physics and BioInspired Syracuse, Syracuse University, Syracuse, NY 13244, USA
| | - J. M. Schwarz
- Department of Physics and BioInspired Syracuse, Syracuse University, Syracuse, NY 13244, USA
- Indian Creek Farm, Ithaca, NY 14850, USA
| | - Edward J. Banigan
- Institute of Medical Engineering & Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Andrew D. Stephens
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
- Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
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Unique Astrocyte Cytoskeletal and Nuclear Morphology in a Three-Dimensional Tissue-Engineered Rostral Migratory Stream. NEUROGLIA (BASEL, SWITZERLAND) 2022; 3:41-60. [PMID: 36776937 PMCID: PMC9910099 DOI: 10.3390/neuroglia3010003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neural precursor cells (NPCs) are generated in the subventricular zone (SVZ) and travel through the rostral migratory stream (RMS) to replace olfactory bulb interneurons in the brains of most adult mammals. Following brain injury, SVZ-derived NPCs can divert from the RMS and migrate toward injured brain regions but arrive in numbers too low to promote functional recovery without experimental intervention. Our lab has biofabricated a "living scaffold" that replicates the structural and functional features of the endogenous RMS. This tissue-engineered rostral migratory stream (TE-RMS) is a new regenerative medicine strategy designed to facilitate stable and sustained NPC delivery into neuron-deficient brain regions following brain injury or neurodegenerative disease and an in vitro tool to investigate the mechanisms of neuronal migration and cell-cell communication. We have previously shown that the TE-RMS replicates the basic structure and protein expression of the endogenous RMS and can direct immature neuronal migration in vitro and in vivo. Here, we further describe profound morphological changes that occur following precise physical manipulation and subsequent self-assembly of astrocytes into the TE-RMS, including significant cytoskeletal rearrangement and nuclear elongation. The unique cytoskeletal and nuclear architecture of TE-RMS astrocytes mimics astrocytes in the endogenous rat RMS. Advanced imaging techniques reveal the unique morphology of TE-RMS cells that has yet to be described of astrocytes in vitro. The TE-RMS offers a novel platform to elucidate astrocyte cytoskeletal and nuclear dynamics and their relationship to cell behavior and function.
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