Yee Cindy L, Jones Kevin R, Finger Thomas E
Rocky Mountain Taste and Smell Center, Denver, Colorado 80262, USA.
J Comp Neurol. 2003 Apr 21;459(1):15-24. doi: 10.1002/cne.10589.
Brain-derived neurotrophic factor (BDNF), one of the members of the nerve growth factor family of neurotrophins, is expressed in developing gustatory papillae and is thought to be the neurotrophin that supports gustatory innervation during development. BDNF expression does not cease after development but continues in some taste cells of adult mice. To determine which types of taste cells produce BDNF, we undertook an immunohistochemical study of taste cells in BDNF(LacZ) gene targeted "knock-in" adult mice. In these mice, beta-galactosidase (beta-gal) immunoreactivity is an indicator of cells that produce BDNF transcripts. In the tongues of adult BDNF(LacZ) mice, beta-gal (BDNF) is present in long slender taste cells, as well as pyriform taste cells. Bromodeoxyuridine labeling experiments in BDNF(LacZ) mice indicate that BDNF is not present in taste cells that are younger than 3 days postmitotic. BDNF mainly colocalizes with markers of type II and type III taste cells: ubiquitin carboxyl terminal hydrolase (PGP 9.5), serotonin (5-HT), neural cell adhesion molecule (N-CAM), synaptic associated protein of 25 kDa (SNAP-25), and to a lesser extent with alpha-gustducin. beta-Gal immunoreactivity is not associated with blood group H antigen, a marker of type I taste cells. We conclude that BDNF is absent from basal cells and type I (blood group H antigen immunoreactive) taste cells but is present in differentiated type II and type III taste cells. The presence of SNAP-25 in BDNF-expressing cells suggests a role for BDNF in synaptic formation and transmission.
脑源性神经营养因子（BDNF）是神经营养因子神经生长因子家族的成员之一，在发育中的味觉乳头中表达，被认为是在发育过程中支持味觉神经支配的神经营养因子。BDNF的表达在发育后并未停止，而是在成年小鼠的一些味觉细胞中持续存在。为了确定哪些类型的味觉细胞产生BDNF，我们对BDNF（LacZ）基因靶向“敲入”成年小鼠的味觉细胞进行了免疫组织化学研究。在这些小鼠中，β-半乳糖苷酶（β-gal）免疫反应性是产生BDNF转录本的细胞的指标。在成年BDNF（LacZ）小鼠的舌头中，β-gal（BDNF）存在于细长的味觉细胞以及梨状味觉细胞中。BDNF（LacZ）小鼠的溴脱氧尿苷标记实验表明，BDNF不存在于有丝分裂后3天以内的味觉细胞中。BDNF主要与II型和III型味觉细胞的标记物共定位：泛素羧基末端水解酶（PGP 9.5）、5-羟色胺（5-HT）、神经细胞粘附分子（N-CAM）、25 kDa的突触相关蛋白（SNAP-25），并且在较小程度上与α-味导素共定位。β-gal免疫反应性与I型味觉细胞的标记物血型H抗原不相关。我们得出结论，BDNF在基底细胞和I型（血型H抗原免疫反应性）味觉细胞中不存在，但在分化的II型和III型味觉细胞中存在。在表达BDNF的细胞中存在SNAP-25表明BDNF在突触形成和传递中起作用。
