Downregulation of Cav3.1 T-type Calcium Channel Expression in Age-related Hearing Loss Model.

OBJECTIVE: Age-related hearing loss (AHL), characterized by degeneration of cochlea structures, is the most common sensory disorder among the elderly worldwide. The calcium channel is considered to contribute to normal hearing. However, the role of the T-type voltage-activated calcium channel, Cav3.1, remains unclear in AHL. Here, we investigate the age-related change of Cav3.1 expression in the cochlea and D-gal-induced senescent HEI-OC1 cells. METHODS: Cochleae from C57BL/6 mice at 2 months and 12 months of age were assessed. Senescence in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells was induced by D-gal treatment. The immunofluorescence technique was employed to investigate the distribution of Cav3.1 in vivo and in vitro. Quantitative assessment was achieved by Western blotting and real-time PCR. RESULTS: In comparison with 2-month-old animals, 12-month old C57BL/6 mice exhibited great loss of hair cells and elevated auditory brainstem threshold. The Cav3.1 was located in hair cells, spiral ganglion cells, lateral walls, and the expression of Cav3.1 protein and mRNA decreased in the aged cochleae. D-gal-induced senescence assay confirmed the down-regulation of Cav3.1 expression in senescent HEI-OC1 cells. CONCLUSION: Our results show that age-related down-regulated expression of Cav3.1 in the cochleae is associated with AHL and may contribute to the pathogenesis of AHL.

Serum level and clinical significance of vitamin E in children with allergic rhinitis.

BACKGROUND: Allergic rhinitis (AR) is one of the most prevalent allergic diseases in children. This study aimed to investigate the association between serum concentrations of vitamin E and AR to determine if the vitamin E level is correlated with the occurrence and severity of AR. METHODS: A total of 113 children were enrolled in this cross-sectional study. Sixty-five children in the outpatient group were diagnosed with AR, and 48 healthy children were recruited as controls. All subjects underwent serum vitamin E (adjusted for total cholesterol and triglycerides) measurements. Serum to total IgE (tIgE), the five most common allergen-specific IgE (sIgE) levels and skin prick test (SPT) were measured in children with AR. The severity of AR was assessed with the nasal symptoms score, and the situation of exposure to passive smoking were inquired. RESULTS: Serum vitamin E levels were significantly lower in the AR group than in the normal children (P < 0.001). A significant negative correlation was observed between serum vitamin E levels and sIgE as well as the SPT grade. Serum vitamin E levels were also inversely related to the nasal symptoms score; however, statistical significance was not found. CONCLUSIONS: A significantly lower vitamin E level was found in children with AR. Lower serum vitamin E levels may have correlation with the occurrence of AR in children. However, serum vitamin E levels were not statistically correlated with the severity of AR.

Downregulation of inwardly rectifying potassium channel 5.1 expression in C57BL/6J cochlear lateral wall.

Age-related hearing loss (AHL) is one of the most common sensory disorders among elderly persons. The inwardly rectifying potassium channel 5.1 (Kir5.1) plays a vital role in regulating cochlear K(+) circulation which is necessary for normal hearing. The distribution of Kir5.1 in C57BL/6J mice cochleae, and the relationship between the expression of Kir5.1 and the etiology of AHL were investigated. Forty C57BL/6J mice were randomly divided into four groups at 4, 12, 24 and 52 weeks of age respectively. The location of Kir5.1 was detected by immunofluorescence technique. The mRNA and protein expression of Kir5.1 was evaluated in mice cochleae using real-time polymerase-chain reactions (RT-PCR) and Western blotting respectively. Kir5.1 was detected in the type II and IV fibrocytes of the spiral ligament in the cochlear lateral wall of C57BL/6J mice. The expression levels of Kir5.1 mRNA and protein in the cochleae of aging C57BL/6J mice were down-regulated. It was suggested that the age-related decreased expression of Kir5.1 in the lateral wall of C57BL/6J mice was associated with hearing loss. Our results indicated that Kir5.1 may play an important role in the pathogenesis of AHL.

Expression of HMGA1 and ezrin in laryngeal squamous cell carcinoma.

CONCLUSION: The overexpression of HMGA1 or Ezrin may contribute to the carcinogenesis, development, and metastasis of laryngeal squamous cell carcinoma (LSCC). OBJECTIVE: To investigate the expression of HMGA1 and Ezrin in LSCC and analyze their clinical significance. METHODS: The expression of HMGA1 and Ezrin was analyzed by immunohistochemistry (IHC) in 50 cases of LSCC. Thirty cases of laryngeal polyp and 30 cases of atypical hyperplasia of larynx were studied as controls. The expression of HMGA1 and Ezrin was analyzed by real-time PCR and by Western blot in 30 cases of LSCC; samples from adjacent normal epithelial tissues in 30 cases were studied as controls. RESULTS: (1) IHC revealed that the positive rate of HMGA1 protein was 68.0% (34/50), 53.3% (16/30), and 13. 3% (4/30) in LSCC, atypical hyperplasia of larynx, and laryngeal polyp (p < 0.05), and the positive rate of Ezrin protein was 64.0% (32/50), 50.0% (15/30), and 23.3% (7/30) (p < 0.01), respectively. (2) Real-time PCR demonstrated that the mean relative mRNA expression levels of HMGA1 in LSCC and in normal tissues were 2.41 ± 0.40 and 1.05 ± 0.18, respectively (p < 0.01). The mRNA levels of Ezrin in LSCC and in normal tissues were 1.79 ± 0.27 and 1.04 ± 0.22, respectively (p < 0.05). (3) Western blotting revealed that the mean relative protein expression levels of HMGA1 in LSCC and in normal tissues were 1.73 ± 0.60 and 0.35 ± 0.17, respectively (p < 0.01). The protein levels of Ezrin in LSCC and in normal tissues were 1.82 ± 0.77 and 0.42 ± 0.20, respectively (p < 0.01).