Du Jing
National Institute of Mental Health, Bethesda, MD 20892-1381, USA.
Zhen Ci Yan Jiu. 2008 Feb;33(1):37-40.
Neurotrophic factors and cytokines are involved in the regulation of neuronal survival, axonal myelination, and synaptic plasticity in both central nervous system (CNS) and peripheral nervous system (PNS). The members of the neurotrophic factor family include nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). These molecules bind to two types of receptors: (1) tyrosine kinase receptors (TrkA, TrkB, TrkC) and 2) common neurotrophin receptor (p 75 NTR). The internalization and retrograde axonal transport of neurotrophin receptors are important for their signal transduction supporting neuronal survival, synaptic plasticity, and axonal myelination. In addition, a growing body of data suggests that neurotrophins are involved in the pathophysiologicl courses of inflammatory pain, neurodegenerative disease, and psychiatric diseases. Cytokines, including IL-1, IL-2, IL-6, and TNF-alpha,are important mediators of the immune response and play a key role in the diseases by acting on inflammatory immune cells, neuronal cells, muscle cells, and vessel cells. Interestingly, some cytokines (e.g. TNF-alpha, IL-2, TGF-beta) are also able to regulate synaptic plasticity and affect CNS functions. The neurotrophins and cytokines release in response to various stimuli, such as electronic stimulation, or inflammation. This crosstalk from PNS to CNS is involved in the pathophysiology of many human diseases and may contribute to the effects of acupuncture. Based on our knowledge to neurotrophins and cytokines, we proposed the neurotrophin/cytokine hypothesis for the mechanism of acupuncture. This hypothesis may initiate the discussion on the possible roles of neurotrophins/cytokines in the therapeutic effects of acupuncture and shed light to the discovery of mechanism of acupuncture in the treatment of devastating diseases.
神经营养因子和细胞因子参与中枢神经系统（CNS）和周围神经系统（PNS）中神经元存活、轴突髓鞘形成和突触可塑性的调节。神经营养因子家族成员包括神经生长因子（NGF）、脑源性神经营养因子（BDNF）、神经营养素-3（NT-3）和神经营养素-4/5（NT-4/5）。这些分子与两种类型的受体结合：（1）酪氨酸激酶受体（TrkA、TrkB、TrkC）和（2）共同神经营养素受体（p75NTR）。神经营养素受体的内化和逆行轴突运输对于其支持神经元存活、突触可塑性和轴突髓鞘形成的信号转导很重要。此外，越来越多的数据表明神经营养素参与炎症性疼痛、神经退行性疾病和精神疾病的病理生理过程。细胞因子，包括白细胞介素-1、白细胞介素-2、白细胞介素-6和肿瘤坏死因子-α，是免疫反应的重要介质，通过作用于炎症免疫细胞、神经元细胞、肌肉细胞和血管细胞在疾病中起关键作用。有趣的是，一些细胞因子（如肿瘤坏死因子-α、白细胞介素-2转化生长因子-β）也能够调节突触可塑性并影响中枢神经系统功能。神经营养因子和细胞因子会响应各种刺激（如电刺激或炎症）而释放。这种从周围神经系统到中枢神经系统的相互作用参与了许多人类疾病的病理生理过程，可能有助于针灸的疗效。基于我们对神经营养因子和细胞因子的了解，我们提出了神经营养因子/细胞因子假说以解释针灸的机制。该假说可能引发关于神经营养因子/细胞因子在针灸治疗效果中可能作用的讨论，并为发现针灸治疗毁灭性疾病的机制提供线索。
