DNAJB6 isoform specific knockdown: Therapeutic potential for limb girdle muscular dystrophy D1
Abstract
Dominant missense mutations in DNAJB6, a co-chaperone of HSP70, cause limb girdle muscular dystrophy (LGMD) D1. No treatments are currently available. Two isoforms exist, DNAJB6a and DNAJB6b, each with distinct localizations in muscle. Mutations reside in both isoforms, yet evidence suggests that DNAJB6b is primarily responsible for disease pathogenesis. Knockdown treatment strategies involving both isoforms carry risk, as DNAJB6 knockout is embryonic lethal. We therefore developed an isoform-specific knockdown approach using morpholinos. Selective reduction of each isoform was achieved in vitro in primary mouse myotubes and human LGMDD1 myoblasts, as well as in vivo in mouse skeletal muscle. To assess isoform specific knockdown in LGMDD1, we created primary myotube cultures from a knockin LGMDD1 mouse model. Using mass spectrometry, we identified an LGMDD1 protein signature related to protein homeostasis and myofibril structure. Selective reduction of DNAJB6b levels in LGMDD1 myotubes corrected much of the proteomic disease signature toward wild type levels. Additional in vivo functional data is required to determine if selective reduction of DNAJB6b is a viable therapeutic target for LGMDD1.
Additional Information
© 2023 The Author(s). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). This work was supported by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS): ARF (K08AR075894, R03AR081395), CCW (R01AR068797, K24AR073317); the American Society of Gene and Cell therapy (ASGCT): ARF (Career Development Award); the Children's Discovery Institute of Saint Louis Children's Hospital: ARF (Faculty Scholar Award- MIFR20221004); and the LGMD-1D DNAJB6 Foundation and International Registry (ARF). The graphical abstract was created with BioRender. Author contributions. A.R.F.: conceptualization, formal analysis, funding acquisition, investigation, methodology, resources, supervision, validation, visualization, writing original draft, writing – review and editing. M.M.P., J.A.D., M.E.H., R.B., S.K.P., S.L., F.W., and T.C.: investigation, methodology. H.L.T. and T.M.M.: conceptualization, writing – review and editing. C.C.W.: conceptualization, funding acquisition, resources, supervision, validation, writing – review and editing. Data availability. Qualified researchers may request access to the data that support the findings of this study from the corresponding author. Declaration of interests. A.R.F. and C.C.W. are co-inventors on a pending patent application related to this publication (USPTO serial no. 17/932,996).Attached Files
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Supplemental Material - 1-s2.0-S216225312300135X-mmc1.xlsx
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Additional details
- PMCID
- PMC10280091
- Eprint ID
- 122025
- Resolver ID
- CaltechAUTHORS:20230628-257129000.25
- K08AR075894
- NIH
- R03AR081395
- NIH
- R01AR068797
- NIH
- K24AR073317
- NIH
- American Society of Gene and Cell Therapy
- MIFR20221004
- Saint Louis Children's Hospital
- LGMD-1D DNAJB6 Foundation
- Created
-
2023-06-30Created from EPrint's datestamp field
- Updated
-
2023-06-30Created from EPrint's last_modified field
- Caltech groups
- Division of Biology and Biological Engineering