What they found
First proof-of-concept STRC gene therapy in Strc-/- mice. Dual AAV (PHP.B serotype) delivering split STRC injected at P1. Confirmed STRC protein at OHC stereocilia tips, structural restoration, and partial hearing recovery.
Key numbers
- Injection age: P1 (postnatal day 1) — NEONATAL ONLY
- OHC transduction: 59% of OHC bundles showed distinct STRC localization
- Hearing recovery: 50-60 dB improvement in best responders; thresholds as low as 30 dB
- Bundle morphology: 61-65% of bundles showed normal organization and top connectors
- TM attachment: Restored — attachment crowns reformed after STRC delivery
Critical finding on TM re-attachment
Even in full STRC knockout mice, where TM imprints were ABSENT (Verpy 2011), gene therapy at P1 successfully restored TM-OHC attachment crowns.
This means: TM contact can reform when STRC is provided, even starting from zero. The TM retains the structural capacity to embed stereocilia tips if STRC is present.
For adult treatment, this is cautiously positive — but untested.
Age limitation (explicit from paper)
“Because injection in adult mouse cochleas is technically challenging, we focused on vector delivery during the first postnatal week, and whether dual vector delivery of STRC into mature cochleas is a viable treatment option remains to be determined.”
This is the critical open question. No adult data exists.
Comparison to Iranfar 2026
Iranfar (CTM 2026) is a more recent replication using AAV9-PHP.eB with similar results. Both papers demonstrate neonatal STRC restoration. Neither tests adult.
Relevance to Misha
The TM re-attachment finding is encouraging: even full KO cochlea can reform TM contact. Misha’s partial STRC likely maintained more TM contact than KO. His cochlea is probably in a BETTER state for rescue than the KO mice that were treated.
The gap: no one has tried delivery at P30+, P60+, or adult in STRC-null mice. This is the experiment the field needs — and the data Misha’s program needs.
Links
- PubMed: https://pubmed.ncbi.nlm.nih.gov/34910522/
- PMC: https://pmc.ncbi.nlm.nih.gov/articles/PMC8673757/
- DOI: https://doi.org/10.1126/sciadv.abi7629
Connections
- STRC Stereocilia Bundle Mechanics Model — TM crown reformation from full-KO baseline at P1
- STRC Dual-Vector vs Single-Vector Transduction — published baseline (59% OHC, 50–60 dB gain) for the dual-vector arm
- Adult Treatment Window STRC — only existing STRC gene therapy data, P1 only