[Effect of acupuncture intervention on neurological function, cerebral microglia activation and secondary nerve damage in traumatic brain injury rats].

OBJECTIVE: To observe the effect of acupuncture on activities of microglia in traumatic brain injury (TBI) rats. METHODS: Fifty-four male SD rats were randomly and equally divided into normal control, model and acupuncture groups according to the random number table (n＝18 rats in each group). The TBI model was established by using a free fall brain injury striking device after exposing the local cranial bone (to induce the left parietal cerebral contusion). Acupoints "Baihui" (GV20), "Shuigou" (GV26), "Fengfu" (GV16), "Yamen" (GV15) and bilateral "Hegu" (LII4) were stimulated intensively by twirling the filiform needles with force at a range of >360° and a frequency of 160－180 cycles/min for 10 sec in every acupoint, once every 5 min during the 15 minutes' needle retaining. The treatment was given once every day for successive 14 days. The rats of the normal and model groups were grabbed and fixed with the same procedure. The behavioral changes were tested using modified neurological severity score (mNSS). The histopathological changes of the injured cerebral cortex tissues were observed by using hematoxylin-eosin (H.E.) staining, and the fluorescence intensity of Iba-1 (marker of microglia) positive products in the surrounding tissue of the cerebral focus was displayed by immunofluorescence staining, and the contents of neuron specific enolate (NSE) and neurite outgrowth inhibitor-A (Nogo-A) in serum (indicating a secondary nerve damage) were assayed by ELISA. RESULTS: The mNSS scores were significantly increased on day 1, 3, 7 and 14 in the model group in comparison with the normal group (P<0.01) and considerably decreased at the 4 time-points after acupuncture intervention relevant to the model group (P<0.05, P<0.01). H．E. staining showed that modeling induced pathological changes such as the excursion of cell nucleus, cellular swel-ling, vacuole-like change, neuron death, karyopyknosis dissolution, and proliferation of fibrous tissue were relatively milder in the acupuncture group. The average fluorescence intensity values of Iba-1-positive products, serum NSE and Nogo-A contents on day 3, 7 and 14 were significantly higher in the model group than in the normal group (P<0.05, P<0.01), and notably down-regulated in the acupuncture group than in the model group (P<0.05, P<0.01, except Nogo-A on day 3). CONCLUSION: Acupuncture intervention may accelerate neurological function recovery in TBI rats, which is closely related to its effects in inhibiting the activation of microglia and secondary nerve damage.

Effect of acupuncture on the TLR2/4-NF-κB signalling pathway in a rat model of traumatic brain injury.

OBJECTIVE: To study the effect of acupuncture on the TLR2/4-NF-κB signalling pathway in the cortex of Sprague-Dawley rats following traumatic brain injury (TBI), and investigate the possible mechanism underlying the effects of acupuncture on scar repair. METHODS: TBI was established using Feeney's free-falling epidural percussion model. In total, 108 rats were randomly divided into a normal group (n=18), untreated TBI model group (TBI group, n=36) and manual acupuncture-treated TBI group (TBI+MA, n=36). Each group of rats was subdivided into three time groups: 3-day (3d), 7-day (7d) and 14-day (14d). No treatment was given to rats in the normal and TBI groups. The TBI+MA group received manual acupuncture at GV20, GV26, GV16 through GV15, and bilateral LI4. mRNA expression of TLR2, TLR4, NF-κB and protein in the rat cortices was quantified using real-time fluorescence quantitative polymerase chain reaction (qPCR) and Western blot analyses. RESULTS: The modified neurological severity score (mNSS) scores of the TBI+MA group were improved compared with baseline scores 12 hours after modelling, and improved at 7d and 14d compared with the TBI group (P<0.05), while the score of the TBI group did not improve until 14d compared to baseline. mRNA and protein expression of TLR2, TLR4 and NF-κB in the TBI group were higher than the normal group at 3d (P<0.05), reached a peak at 7d, then began to decrease at 14d. mRNA and protein expression of TLR2, TLR4 and NF-κB were higher in the TBI+MA group compared with the TBI group at 3d (P<0.05), were significantly down-regulated at 7d (P<0.01), and decreased to normal levels at 14d. CONCLUSIONS: Acupuncture has a bidirectional regulatory effect on the TLR2/4-NF-κB signalling pathway-related genes TLR2, TLR4 and NF-κB in the TBI rat cortex, promoting their expression in the early stage and inhibiting it in the later stage.

Effects of acupuncture on cortical expression of Wnt3a, ß-catenin and Sox2 in a rat model of traumatic brain injury.

OBJECTIVE: To observe the effects of acupuncture treatment on the expression of Wnt/ß-catenin signalling pathway-related genes (Wnt3a, ß-catenin and Sox2) in the injured cerebral cortex of rats with traumatic brain injury (TBI). METHODS: A controlled impact model of TBI was established using Feeney's free-drop method. Seventy-eight Sprague-Dawley rats were randomly divided into the following three groups: a normal group (n=18) that was left untreated; a model group (n=30) that received no treatment after TBI; and an acupuncture group (n=30) that received acupuncture (at LI4, GV20, GV26 and GV16) after TBI. Rats in each group were randomly and equally divided into 3-day, 7-day and 14-day subgroups according to the duration of therapy. Real-time fluorescence quantitative PCR (RT-qPCR) was used to measure mRNA expression of Wnt3a, ß-catenin and Sox2. Western blots were performed to determine the expression levels of WNT3a, ß-Catenin and SOX2. RESULTS: Wnt3a mRNA was upregulated in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.05). ß-catenin expression was significantly increased in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.01). In the 3-day and 7-day acupuncture subgroups, Sox2 expression was significantly higher than that in the normal and model groups (p<0.01 each). The levels of WNT3a, ß-catenin and SOX2 were generally consistent with the corresponding mRNA levels. CONCLUSIONS: Acupuncture exerts a regulatory effect on the Wnt/ß-catenin signalling pathway, which may in turn influence the proliferation and differentiation of endogenous neural stem cells.

Effect of acupuncture on proliferation and differentiation of neural stem cells in brain tissues of rats with traumatic brain injury.

OBJECTIVE: To observe the effect of acupuncture on proliferation and differentiation of neural stem cells in brain tissues of rats with traumatic brain injuny. METHODS: Thirty SD rats were randomly and equally allocated to the sham-operated, the model and the acupuncture groups. The traumatic brain injury model was established by the free drop method. For the rats in the acupuncture group, acupuncture was applied once a day for 7 days. Brain histotomy was carried out when treatments were completed. Immunohistochemical techniques were adopted to detect the cells that express nestin, neurofilament proteins (NF)-200 and glial fibrillary acidic proteins (GFAP), the markers of neural stem cells, neurons, astrocytes respectively. RESULTS: Compared to the sham-operated group, the number of nestin-positive cells and NF-200-positive cells in brain tissues was decreased significantly in the model group (P < 0.01), whereas the number of GFAP-positive cells was significantly increased P<0.01). Compared to the model group, the positive cells of nestin, NF-200, GFAP in brain tissues in the acupuncture group were increased obviously (P<0.01). CONCLUSIONS: Acupuncture can significantly increase the number of nestin-positive cells, NF-200-positive cells and GFAP-positive cells, indicating the significant increase of neural stem cells, neurons and astrocytes in number. Acupuncture can improve neuranagenesis by promoting the proliferation and differentiation of neural stem cells in brain tissues. This might be one of the mechanisms for acupuncture to treat traumatic brain injury and to promote the repair of nervous function.