Myotonic dystrophy type 1 (DM1) is the most common adult-onset muscular
dystrophy, primarily characterized by muscle wasting and weakness. Many
biomarkers already exist in the rapidly developing biomarker research
field that aim to improve patients' care. Limited work, however, has
been performed on rare diseases, including DM1. We have previously shown
that specific microRNAs (miRNAs) can be used as potential biomarkers for
DM1 progression. In this report, we aimed to identify novel serum-based
biomarkers for DM1 through high-throughput next-generation sequencing. A
number of miRNAs were identified that are able to distinguish DM1
patients from healthy individuals. Two miRNAs were selected, and their
association with the disease was validated in a larger panel of
patients. Further investigation of miR-223-3p, miR-24-3p, and the four
previously identified miRNAs, miR-1-3p, miR-133a-3p, miR133b-3p, and
miR-206-3p, showed elevated levels in a DM1 mouse model for all six
miRNAs circulating in the serum compared to healthy controls.
Importantly, the levels of miR-223-3p, but not the other five miRNAs,
were found to be significantly downregulated in five skeletal muscles
and heart tissues of DM1 mice compared to controls. This result provides
significant evidence for its involvement in disease manifestation