Effect of Electro-Acupuncture on Neuroplasticity of Spinal Cord-Transected Rats

Application and underlying mechanism of acupuncture for the nerve repair after peripheral nerve injury: remodeling of nerve system

Peripheral nerve injury (PNI) is a structural event with harmful consequences worldwide. Due to the limited intrinsic regenerative capacity of the peripheral nerve in adults, neural restoration after PNI is difficult. Neurological remodeling has a crucial effect on the repair of the form and function during the regeneration of the peripheral nerve after the peripheral nerve is injured. Several studies have demonstrated that acupuncture is effective for PNI-induced neurologic deficits, and the potential mechanisms responsible for its effects involve the nervous system remodeling in the process of nerve repair. Moreover, acupuncture promotes neural regeneration and axon sprouting by activating related neurotrophins retrograde transport, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), N-cadherin, and MicroRNAs. Peripheral nerve injury enhances the perceptual response of the central nervous system to pain, causing central sensitization and accelerating neuronal cell apoptosis. Together with this, the remodeling of synaptic transmission function would worsen pain discomfort. Neuroimaging studies have shown remodeling changes in both gray and white matter after peripheral nerve injury. Acupuncture not only reverses the poor remodeling of the nervous system but also stimulates the release of neurotrophic substances such as nerve growth factors in the nervous system to ameliorate pain and promote the regeneration and repair of nerve fibers. In conclusion, the neurological remodeling at the peripheral and central levels in the process of acupuncture treatment accelerates nerve regeneration and repair. These findings provide novel insights enabling the clinical application of acupuncture in the treatment of PNI.

Electroacupuncture alleviates cognitive dysfunction and neuronal pyroptosis in septic mice

BACKGROUND

Sepsis is defined as organ dysfunction caused by an uncontrolled response to infection and is followed by a high incidence of cognitive dysfunction, which can severely affect patients' quality of life. Previous studies have suggested that electroacupuncture (EA) is protective against sepsis-associated cognitive dysfunction and that pyroptosis plays a vital role in cognitive function. The aim of this study was to investigate the effect of EA on cognition and neuronal pyroptosis in a mouse model of sepsis.

METHODS

Sepsis was induced by cecal ligation and puncture (CLP) surgery. Mice were randomly divided into three groups (control, CLP and CLP + EA). EA was performed at bilateral ST36 for three consecutive days after the surgery. The 7-day survival rate of each group was observed on the seventh day after the surgery. The Morris water maze (MWM) was used to test cognitive function from the 8th to 12th day after the surgery. We used transmission electron microscopy (TEM) and transferase dUTP nick-end labeling (TUNEL) staining to determine the structural integrity of hippocampal neuronal membranes and the number of surviving neurons in the hippocampal tissues, respectively. Expression of nucleotide-binding domain-like receptor protein 1 (NLRP1), caspase-1 and gasdermin-D (GSDM D) in hippocampal CA1 neurons was detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and caspase-1 concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

Compared with the CLP group, 7-day survival rates and cognitive function were significantly improved in the CLP + EA group. After EA treatment, the integrity of the hippocampal CA1 neuronal membrane and mortality of hippocampal neurons were significantly decreased, and expression of NLRP1, caspase-1 and GSDM D was downregulated.

CONCLUSION

EA can alleviate cognitive dysfunction and neuronal pyroptosis in septic mice.

Mechanism Underlying Acupuncture Therapy in Spinal Cord Injury: A Narrative Overview of Preclinical Studies

Spinal cord injury (SCI) results from various pathogenic factors that destroy the normal structure and function of the spinal cord, subsequently causing sensory, motor, and autonomic nerve dysfunction. SCI is one of the most common causes of disability and death globally. It leads to severe physical and mental injury to patients and causes a substantial economic burden on families and the society. The pathological changes and underlying mechanisms within SCI involve oxidative stress, apoptosis, inflammation, etc. As a traditional therapy, acupuncture has a positive effect promoting the recovery of SCI. Acupuncture-induced neuroprotection includes several mechanisms such as reducing oxidative stress, inhibiting the inflammatory response and neuronal apoptosis, alleviating glial scar formation, promoting neural stem cell differentiation, and improving microcirculation within the injured area. Therefore, the recent studies exploring the mechanism of acupuncture therapy in SCI will help provide a theoretical basis for applying acupuncture and seeking a better treatment target and acupuncture approach for SCI patients.

The scientific basis of acupuncture for veterinary pain management: A review based on relevant literature from the last two decades

The practice of acupuncture is becoming increasingly popular in veterinary medicine, especially as a method of providing pain relief. Originally based on principles derived from centuries of observation, conventional scientific mechanisms of action for acupuncture as a pain-relieving modality have recently been elucidated. Acupuncture points allow access to multiple regions of the body via the peripheral nervous system and its connection with the central nervous system. Local, segmental (spinal), and suprasegmental (brain) effects of acupuncture involve enhanced release of pain-relieving endogenous substances (e.g., opioids) and mitigated release of pain-inducing substances (e.g., inflammatory cytokines). In addition, there is evidence that acupuncture can induce positive neurochemical and cytoarchitectural change in the central nervous system via the phenomenon of neuroplasticity. Electroacupuncture is considered the most effective type of acupuncture delivery, allowing for more potent and long-lasting pain relief than is achieved via other methods (e.g., dry needling). The purpose of this review article is to summarize the relevant scientific literature from the last two decades relating to the physiological mechanisms of action of acupuncture as a pain-relieving modality.

Insulin-Like Growth Factor-1 Enhances Motoneuron Survival and Inhibits Neuroinflammation After Spinal Cord Transection in Zebrafish

Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor produced locally in the central nervous system which can promote axonal regeneration, protect motoneurons, and inhibit neuroinflammation. In this study, we used the zebrafish spinal transection model to investigate whether IGF-1 plays an important role in the recovery of motor function. Unlike mammals, zebrafish can regenerate axons and restore mobility in remarkably short period after spinal cord transection. Quantitative real-time PCR and immunofluorescence showed decreased IGF-1 expression in the lesion site. Double immunostaining for IGF-1 and Islet-1 (motoneuron marker)/GFAP (astrocyte marker)/Iba-1 (microglia marker) showed that IGF-1 was mainly expressed in motoneurons and was surrounded by astrocyte and microglia. Following administration of IGF-1 morpholino at the lesion site of spinal-transected zebrafish, swimming test showed retarded recovery of mobility, the number of motoneurons was reduced, and increased immunofluorescence density of microglia was caused. Our data suggested that IGF-1 enhances motoneuron survival and inhibits neuroinflammation after spinal cord transection in zebrafish, which suggested that IGF-1 might be involved in the motor recovery.

Effects and Mechanisms of Acupuncture Combined with Mesenchymal Stem Cell Transplantation on Neural Recovery after Spinal Cord Injury: Progress and Prospects

Spinal cord injury (SCI) is a structural event with devastating consequences worldwide. Due to the limited intrinsic regenerative capacity of the spinal cord in adults, the neural restoration after SCI is difficult. Acupuncture is effective for SCI-induced neurologic deficits, and the potential mechanisms responsible for its effects involve neural protection by the inhibition of inflammation, oxidation, and apoptosis. Moreover, acupuncture promotes neural regeneration and axon sprouting by activating multiple cellular signal transduction pathways, such as the Wnt, Notch, and Rho/Rho kinase (ROCK) pathways. Several studies have demonstrated that the efficacy of combining acupuncture with mesenchymal stem cells (MSCs) transplantation is superior to either procedure alone. The advantage of the combined treatment is dependent on the ability of acupuncture to enhance the survival of MSCs, promote their differentiation into neurons, and facilitate targeted migration of MSCs to the spinal cord. Additionally, the differentiation of MSCs into neurons overcomes the problem of the shortage of endogenous neural stem cells (NSCs) in the acupuncture-treated SCI patients. Therefore, the combination of acupuncture and MSCs transplantation could become a novel and effective strategy for the treatment of SCI. Such a possibility needs to be verified by basic and clinical research.

Electro-acupuncture-induced neuroprotection is associated with activation of the IGF-1/PI3K/Akt pathway following adjacent dorsal root ganglionectomies in rats

The aim of the present study was to investigate the putative role and underlying mechanisms of insulin-like growth factor 1 (IGF-1) in mediating neuroplasticity in rats subjected to partial dorsal root ganglionectomies following electro-acupuncture (EA) treatment. The rats underwent bilateral removal of the L1-L4 and L6 dorsal root ganglia (DRG), sparing the L5 DRG, and were subsequently subjected to 28 days of EA treatment at two paired acupoints, zusanli (ST 36)-xuanzhong (GB 39) and futu (ST 32)-sanyinjiao (SP 6), as the EA Model group. Rats that received partial dorsal root ganglionectomies without EA treatment served as a control (Model group). Subsequently, herpes simplex virus (HSV)-IGF-1, HSV-small interfering (si) RNA-IGF-1 and the associated control vectors were injected into the L5 DRG of rats in the EA Model group. HSV-IGF-1 transfection enhanced EA-induced neuroplasticity, which manifested as partial recovery in locomotor function, remission hyperpathia, growth of DRG-derived spared fibers, increased expression of phosphorylated (p-) phosphatidylinositol 3-kinase (PI3K) and Akt, and increased pPI3K/PI3K and pAkt/Akt expression ratios. By contrast, HSV-siRNA-IGF-1 treatment attenuated these effects induced by HSV-IGF-1 transfection. The results additionally demonstrated that HSV-IGF-1 transfection augmented the outgrowth of neurites in cultured DRG neurons, and interference of the expression of IGF-1 retarded neurite outgrowth. Co-treatment with a PI3K inhibitor or Akt siRNA inhibited the aforementioned effects induced by the overexpression of IGF-1. In conclusion, the results of the present study demonstrated the crucial roles of IGF-1 in EA-induced neuroplasticity following adjacent dorsal root ganglionectomies in rats via the PI3K/Akt signaling pathway.

Efficacy of Acupuncture Therapy for Chemotherapy-Related Cognitive Impairment in Breast Cancer Patients

Background

Chemotherapy can cause adverse effects such as chemotherapy-related cognitive impairment (CRCI). In this prospective study, the efficacy of traditional Chinese medicine acupuncture therapy in relieving CRCI and its impact on serum brain-derived neurotrophic factor (BDNF) are evaluated.

Material/Methods

Eighty patients were randomly divided into a treatment group and a control group with 40 patients in each group. The treatment group was treated at the following acupuncture points: Baihui (DU20), Sishencong (EX-HN1), Shenting (DU24), Zusanli (ST36), Taixi (K13), Dazhong (K14), and Juegu (GB39). Cognitive function was assessed using the functional assessment of cancer treatment cognition test (FACT-COG, version 3), the auditory-verbal learning test (AVLT), the verbal fluency test (VFT), the symbol digit modality test (SDMT), the clock-drawing test (CDT), and the trail-making test part B (TMT-B). In addition, blood serum levels of BDNF were measured before and after treatment. Correlations between change in BDNF levels and cognitive function were also analyzed.

Results

CRCI was ameliorated in the acupuncture treatment group, with scores on FACT-COG, AVLT-recognition and CDT assessments all significantly increased (P<0.05 in all cases). In addition, serum BDNF levels after acupuncture treatment were significantly higher than before treatment (t=3.242, P<0.01). Moreover, the level of BDNF was positively correlated with the total score of FACT-COG, AVLT-recognition, and CDT (r=0.694, 0.628, and 0.532, respectively; all P<0.05). The control group showed no statistically significant difference in any measures over the same period.

Conclusions

Acupuncture therapy is effective in the treatment of CRCI in breast cancer patients through a mechanism that may be related to an increase of BDNF.