BACKGROUND: Several studies have demonstrated that SH2-B β is over-expressed in the lung, C7-T5 spinal ganglia, and the corresponding spinal dorsal horn of asthmatic mice. SH2-Bβ expression has been shown to positively correlate with nerve growth factor (NGF) expression levels. This indicates that SH2-Bβ, in the presence of NGF, may participate in asthmatic attacks.OBJECTIVE: To observe the effects of anti-NGF on SH2-Bβ expression in primary afferent neurons (C7-T5 spinal ganglia and corresponding spinal dorsal horn) and in the lung to further investigate the regulatory effects of NGF on SH2-Bβexpression.DESIGN, TIME AND SETTING: A completely randomized block design experiment was performed at the Department of Neurobiology, China Medical University between March 2004 and July 2005.MATERIALS: Thirty-six male, BALB/c mice were included in this study. Ovalbumin solution was purchased from Sigma, USA. SH2-B 13 polyclonal antibody was provided by Santa Cruz, USA. Anti-NGF reagent was obtained from Wuhan Boster Bioengineering Co., Ltd., China.METHODS: Thirty-six mice were randomly and evenly divided into three groups: control, model, and anti-NGF. In the model group, asthma was induced by intraperitoneal injection and aerosol inhalation of ovalbumin solution. Mice in the anti-NGF group received anti-NGF through the nasal cavity 3 hours prior to aerosol inhalation. In the control group, mice were subjected to experimental procedures similar to the model group, except that ovalbumin solution was replaced by phosphate buffered saline (PBS).MAIN OUTCOME MEASURES: SH2-Bβ expression in primary afferent neurons (C7-T5 spinal ganglia and the corresponding spinal dorsal horn) and the lung was detected by immunohistochemistry and Western blot. Immunostaining intensity level of SH2-Bβ was analyzed using the MetaMorph image analysis system.RESULTS: Immunohistochemistry results revealed that the mean intensity of SH2-Bβ expression in the C7-T5 spinal ganglia, the corresponding spinal dorsal horn, and the lungs was significantly greater in the model group than in the control group (P < 0.01). However, expression was significantly less in the anti-NGF group, compared with the model group (P < 0.01). Western Blot results demonstrated that SH2-B β expression was significantly greater in the model group C7-T5 spinal ganglia and lung, compared with the control group (P < 0.01). However, expression was significantly less in the anti-NGF group, compared with the model group (P < 0.01).CONCLUSION: The present study showed that, in the primary afferent neurons and the lung, SH2-Bβ participated in asthmatic attack. Anti-NGF down-regulated Stt2-Bβ expression in C7-T5 spinal ganglia and the corresponding spinal dorsal horn, as well as the lung, of asthmatic mice. These results indicate that SH2-Bβ could be an important signaling molecule in mediating effects of NGF during asthmatic attack.