Dnm2-KO Mouse

Dnm2, also known as Dynamin 2, belongs to a family of large GTPases. It is well-known for mediating membrane fission by oligomerizing at the neck of membrane invaginations, regulating membrane trafficking and cytoskeleton dynamics. It is ubiquitously expressed and involved in various biological processes [1,2].

Autosomal dominant mutations in Dnm2 cause autosomal dominant centronuclear myopathy (ADCNM) and dominant intermediate Charcot-Marie-Tooth neuropathy (CMT) [1]. CNM mutations may lead to protein hyperactivity, while CMT mutations could impair Dnm2 lipid binding and activity [1]. Dnm2 is also a modifier of X-linked and autosomal recessive forms of CNM, as its protein levels are upregulated in relevant animal models and patient muscle samples [1]. In the Dnm2R369W/+ mouse model for moderate DNM2-CNM, increasing Dnm2 protein level in muscle leads to moderate CNM-like phenotypes, and normalization of Dnm2 levels through intramuscular injection of AAV-shDnm2 significantly improves histopathology and muscle and myofiber hypotrophy [2]. In the Dnm2K562E/+ mouse model carrying the most common DNM2-CMT mutation, increasing BIN1 (an endogenous modulator of Dnm2) exacerbates the phenotypes, while whole-body reduction of Bin1 expression level restores motor performance and ameliorates muscle and structural defects of peripheral nerves [3].

In conclusion, Dnm2 is crucial for membrane fission, membrane trafficking, and cytoskeleton dynamics. Studies using mouse models have revealed its significant roles in neuromuscular diseases such as CNM and CMT, providing insights into disease mechanisms and potential therapeutic strategies targeting Dnm2 [1,2,3].

References:

1. Zhao, Mo, Maani, Nika, Dowling, James J. . Dynamin 2 (DNM2) as Cause of, and Modifier for, Human Neuromuscular Disease. In Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, 15, 966-975. doi:10.1007/s13311-018-00686-0. https://pubmed.ncbi.nlm.nih.gov/30426359/

2. de Carvalho Neves, Juliana, Moschovaki-Filippidou, Foteini, Böhm, Johann, Laporte, Jocelyn. 2023. DNM2 levels normalization improves muscle phenotypes of a novel mouse model for moderate centronuclear myopathy. In Molecular therapy. Nucleic acids, 33, 321-334. doi:10.1016/j.omtn.2023.07.003. https://pubmed.ncbi.nlm.nih.gov/37547294/

3. Goret, Marie, Thomas, Morgane, Edelweiss, Evelina, Messaddeq, Nadia, Laporte, Jocelyn. 2025. BIN1 reduction ameliorates DNM2-related Charcot-Marie-Tooth neuropathy. In Proceedings of the National Academy of Sciences of the United States of America, 122, e2419244122. doi:10.1073/pnas.2419244122. https://pubmed.ncbi.nlm.nih.gov/40042903/