Related Experiment Video
Updated: Jun 27, 2026

Isolation and Culture of Primary Cochlear Hair Cells from Neonatal Mice
Published on: September 15, 2023
Smad5 haploinsufficiency leads to hair cell and hearing loss
Shi-Ming Yang1, Wei-Wei Guo, Yin-Yan Hu
1Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, People's Republic of China. yangsm301@263.net
Abstract:
The Smads are a group of related intracellular proteins critical for transmitting the signals to the nucleus from the transforming growth factor-beta superfamily at the cell surface. Knockout of the Smad5 is embryonic lethal. However, the Smad5 knockout of single allele (+/-) could survive. We used Smad5 heterozygous knockout (+/-) to determine the role of Smad5 in the development of inner ear morphology and function. In situ hybridization showed that Smad5 was expressed predominantly in hair cells, spiral ganglion, and supporting cells. Measurements of hearing thresholds using auditory brainstem response showed that Smad5 defect resulted in progressive hearing loss between 4 and 24 weeks after birth. Morphological examination revealed apoptosis in the inner ear, with significant loss of outer hair cells in adult Smad5 mutant mice. Our results indicated that deficiency in the Smad5-mediated signaling resulted in apoptosis of hair cells, suggesting Smad5 is a gene that may be related with presbycusis.
Related Concept Videos
Unrenewable Cells
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...
Pleiotropy
Hedgehog Signaling Pathway
Hair Cells
Huntington Disease l: Introduction
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...

