摘要
目的：研究溶酶体神经氨酸酶（neuraminidase，Neu1）、保护蛋白／组织蛋白酶A（protective protein／cahepsinA，PPCA）和β-乳糖苷酶（β-galactosidase，β-al）在小鼠内耳的分布及相互影响，观察各自酶缺乏时的听功能改变。方法：分别使用出生后2个月的野生型（Neu1^＋/＋，PPCA^＋/＋和β-gal^＋/＋）小鼠各6只，年龄配对的酶基因缺乏（Neu1^-/-，PPCA^-/-和β-gal^-/-）小鼠作对照，每组6只。用听性脑干反应（ABR）测试短声（click）、短音8，16和32kHz听阈，经活体心脏灌注固定、听泡石蜡包埋和耳蜗连续切片，用免疫组织化学方法确定上述3种酶在内耳的分布情况。结果：Neu1，PPCA和β-gal在内耳不同部位的分布相类似。Neu1最强的染色主要在螺旋神经节细胞、螺旋韧带、螺旋缘、前庭神经节细胞及壶腹嵴、球囊和椭园囊感觉毛细胞，较弱的染色分布于血管纹和Corti器内、外毛细胞及支持细胞；PPCA和β-gal在螺旋神经节和前庭神经节细胞有较强的染色，血管纹、螺旋韧带、螺旋缘和Corti器内、外毛细胞及支持细胞呈较弱的染色反应；各自酶缺乏时内耳免疫染色消失。Neu1^-/-小鼠内耳PPCA和β-gal，以及β-gal^-/-小鼠Neu1和PPCA免疫反应各自无明显改变，而PPCA^-/-小鼠Neu1染色反应消失，β-gal仅存极弱的染色反应。Neu1^-/-，PPCA^-/-和β-gal^-/-小鼠听阈分别较其野生型提高约60～69dB，40～48dB和7～10dB。结论：Neu1，PPCA及β-gal分布于内耳不同组织和细胞，3种酶也以1种多酶复合物的形式存在于内耳；各自酶基因缺乏可致不同程度的听力损害。
Objective To determine the distribution and influence of lysosomal neuraminidase （ Neu1 ）, protective protein/cathepsin A （PPCA） and β-galactosidase （β-gal） in the inner ear of the mouse, and to observe their auditory alterations in enzyme deficiency. Methods Six wild type （2 months postnatal） （Neu1^＋/＋, PPCA^＋/＋ and β-gal^＋/＋ ） mice were used, and Neu1, PPCA and β-gal homozygous （Neu1^-/- , PPCA^-/- and β-gal^-/- ） mice at the same age used as control in this experiment. The auditory thresholds were examined through the auditory brainstem responses （ABR） to click, which tone pips were 8, 16, and 32 kHz. The mice were intracardically perfused with 4% paraformaldehyde. The bulla were further fixed in 4% paraformaldehyde, processed and sectioned with paraffin embedded method. Immunohistochemistry was used to determine the cellular localizations of Neu1, PPCA, and β-gal in the inner ear. Results There was a similar distributive pattern of Neu1, PPCA and β-gal in the inner ear. Neu1 intense staining was observed in the cochlear spiral ganglion cells, spiral limbus, spiral ligament, vestibular ganglion cells, cristae, maculae hair cells, and weak staining in inner hair cells, outer hair cells, supplying cells of the organ of Corti and stria vascularis. The intense staining of PPCA and β-gal were observed in the spiral ganglion and vestibular gangli in the spiral limbus, spiral ligament, stria vascularis and organ of Corti. The on cells, and weak staining inner ear exhibited no staining when Neu1, PPCA and β-gal were deficient, respectively. A positive staining of PPCA and β-gal was presented in Neu1^-/- mice, and as well as Neu1 and PPCA in β-gal^-/- mice. However, the staining of Neu1 was not presented, and only very weak staining of β-gal in PPCA^-/- mice. The auditory thresholds of Neu1, PPCA, and β-gal mice were elevated for 60 -69 dB, 40 -48 dB, and 7 - 10 dB above those of wildtype littermates, respectively. Conclusion Neu1, PPCA and β-gal are distributed in the inner ear of mouse, and the three enzymes also form a lysosomal multi-enzyme complex in the inner ear. The respective enzyme deficiencies can induce the hearing the loss of different levels.
出处
《中南大学学报（医学版）》
CAS
CSCD
北大核心
2006年第1期79-84,共6页
Journal of Central South University ：Medical Science
关键词
溶酶体酶
神经氨酸酶
保护蛋白/组织蛋白酶A
Β-半乳糖苷酶
内耳
聋
小鼠
lysosome
neuraminidase （ Neu1 ）
protective protein/cathepsin A （PPCA）
β-galactosidase （β-gal）
inner ear
deafness
mouse
