ABSTRACT
Depression is a mental illness characterized by persistent negative feelings， which has seriously threatened people's health. In recent years， neuronal autophagy， an important stress response， has also been regarded as a hypothesis for the pathogenesis of depression. Relevant studies have shown that either insufficient or excessive autophagy triggers neuronal damage， and activated or inhibited neuronal autophagy can be observed in animal models of depression. Therefore， neuronal autophagy may be a double-edged sword involved in the pathogenesis of depression. It is believed in traditional Chinese medicine （TCM） that the occurrence of this disease is closely related to liver depression and spleen deficiency. Chinese medicine regulates the neuronal autophagy via multiple ways. The TCM monomers that regulate neuron autophagy are capable of protecting nerves or penetrating the blood-brain barrier. TCM compounds designed for soothing liver or invigorating spleen have been proved effective against this disease， demonstrating that the core pathogenesis of depression lies in liver depression and spleen deficiency. The regulatory effects of TCM on neuronal autophagy in depression models might result from its action on multiple targets， multiple pathways， and multiple systems. This paper discussed the limitations in current research based on the involvement of neuronal autophagy in depression and its treatments， in order to provide ideas for later similar research and that concerning TCM treatment of depression.
ABSTRACT
OBJECTIVE: To investigate the effect of acupuncture stimulation of head acupoints "Jin San Zhen" (JIN's Three Acupuncture Needles Therapy) on behavior reactions, hippocampal neuronal autophagy and expression of autophagy associated proteins (Beclin-1 and light chain 3 Ⅱ/Ⅰ [LC 3 Ⅱ/Ⅰ]) in rats with hypoxic-ischemic brain damage (HIBD) due to fetal intrauterine distress, so as to reveal its underlying mechanisms in improving neonatal HIBD. METHODS: Pregnant SD rats were used in the present study. The HIBD model was established by delayed caesarean delivery and bilateral uterine arteries clipping for 10 minutes. The HIBD rats were randomly divided into model group and acupuncture groups (n＝9 rats in each group). The other 9 rats delivered naturally were used as the normal control group. On day 14 after delivery, the neonatal rats in the acupuncture group received acupuncture stimulation of head acupoints ("Nao San Zhen""Nie San Zhen" and "Zhi San Zhen") by twirling each needle leftward and rightward for 10 times, once a day for 14 d. The open field test and Morris water maze test were used to determine the locomotive activity and spatial learning-memory ability, respectively. The ultrastructure and autophagosomes in the hippocampal neurons were observed by transmission electron microscope. The contents and expression levels of Beclin-1 and LC3 Ⅱ/Ⅰ in the hippocampus tissues were detected by flow cytometry and Western blot, separately. RESULTS: Compared with the normal control group, the time to go out of the central region of open field test, and the escape latency and duration of first platform-quadrant-crossing of spatial exploration of Morris water maze tests were significantly increased (P<0.01，P<0.05，P<0.001), and the total distance and number of activities in the central region, and the target quadrant resistance time and number of platform-cros-sing remarkably decreased in the model group (P<0.01, P<0.05), suggesting a decline of both locomotor activity and learning-memory ability after modeling. The expression level (%) of Beclin-1 protein and ratio of LC3 Ⅱ/Ⅰ proteins were considerably increased in the model group (P<0.01). Following acupuncture interventions, the locomotor activity and spatial learning-memory ability were obviously increased (P<0.05，P<0.01，P<0.001), and the expression of Beclin-1 protein and ratio of LC3 Ⅱ/Ⅰ were further up-regulated relevant to the model group (P<0.001). Moreover, ultrastructural observation showed serrated change of nuclear membrane and widened perinuclear space, vacuolization in the mitochondria, dilation of endoplasmic reticulum and increase of autophagosomes in the hippocampal neurons in the model group. These situations were relatively milder in the acupuncture group. CONCLUSION: Acupuncture of head acupoints of "JIN San Zhen" may increase locomotor activity and learning-memory abi-lity in rats with HIBD due to fetal intrauterine anoxia, which is closely with its effect in promoting hippocampal neuronal autophagy via up-regulating the expression of Beclin-1 and LC3 Ⅱ/Ⅰ.