Toll-Like Receptor 2-Dependent NFB Activation Is Involved in Nontypeable Haemophilus influenzae-Induced Monocyte Chemotactic Protein 1 Up-Regulation in the Spiral Ligament Fibrocytes of the Inner Ear Sung K. Moon, Jeong-Im Woo, Haa-Yung Lee, Raekil Park,† Jun Shimada,‡ Huiqi Pan, Robert Gellibolian, and David J. Lim* The Gonda Department of Cell and Molecular Biology, House Ear Institute, Los A...

Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino)-2-((methylamino)methyl)propane-1-thiol) on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiat...

The inner ear, which manages our senses of hearing and balance, has mechanosensitive hair cells, which convert vibration into electronic signal to depolarize auditory or vestibular neurons. Inner ear functions depend largely on hair cells, their associated neurons and cochlear lateral wall, and defects in these cells result in hearing loss and deafness. Although some investigations indicated ha...

Sensorineural hearing loss is a caused by the loss of the cochlear hair cells with the consequent deafferentation of spiral ganglion neurons. Humans do not show endogenous cellular regeneration in the inner ear and there is no exogenous therapy that allows the replacement of the damaged hair cells. Currently, treatment is based on the use of hearing aids and cochlear implants that present diffe...

Hair cells (HCs) are the sensory preceptor cells in the inner ear, which play an important role in hearing and balance. The HCs of organ of Corti are susceptible to noise, ototoxic drugs, and infections, thus resulting in permanent hearing loss. Recent approaches of HCs regeneration provide new directions for finding the treatment of sensor neural deafness. To have normal hearing function, the ...

11β-hydroxysteroid dehydrogenase (11β-HSD) is an enzyme complex responsible for the conversion of hormonally active cortisol to inactive cortisone, and two isoforms of the enzyme (11β-HSD1 and 11β-HSD2) have been cloned and characterized. An immunohistochemical study was performed to determine the precise distribution of glucocorticoid receptors (GRs) and the isoforms of 11β-HSD in the rat (pos...

Disorders of hearing and balance are most commonly associated with damage to cochlear and vestibular hair cells or neurons. Although these cells are not capable of spontaneous regeneration, progenitor cells in the hearing and balance organs of the neonatal mammalian inner ear have the capacity to generate new hair cells after damage. To investigate whether these cells are restricted in their di...

Cochlin, a product of the COCH gene, is a major constituent of the inner ear extracellular matrix. Type II collagen, a protein that contributes to structural stability, is also a component of this extracellular matrix. In this study, using the postembedding immunogold method, we demonstrate the localization of cochlin and type II collagen in the cochlear duct at the ultrastructural level. The i...

Slitrks are type I transmembrane proteins that share conserved leucine-rich repeat domains similar to those in the secreted axonal guidance molecule Slit. They also show similarities to Ntrk neurotrophin receptors in their carboxy-termini, sharing a conserved tyrosine residue. Among 6 Slitrk family genes in mammals, Slitrk6 has a unique expression pattern, with strong expression in the sensory ...

Congenital human cytomegalovirus (HCMV) occurs in 0.5-1% of live births and approximately 10% of infected infants develop hearing loss. The mechanism(s) of hearing loss remain unknown. We developed a murine model of CMV induced hearing loss in which murine cytomegalovirus (MCMV) infection of newborn mice leads to hematogenous spread of virus to the inner ear, induction of inflammatory responses...