Electro-acupuncture-modulated miR-214 prevents neuronal apoptosis by targeting Bax and inhibits sodium channel Nav1.3 expression in rats after spinal cord injury

Progress in treatment of pathological neuropathic pain after spinal cord injury

Pathological neuropathic pain is a common complication following spinal cord injury. Due to its high incidence, prolonged duration, tenacity, and limited therapeutic efficacy, it has garnered increasing attention from both basic researchers and clinicians. The pathogenesis of neuropathic pain after spinal cord injury is multifaceted, involving factors such as structural and functional alterations of the central nervous system, pain signal transduction, and inflammatory effects, posing significant challenges to clinical management. Currently, drugs commonly employed in treating spinal cord injury induced neuropathic pain include analgesics, anticonvulsants, antidepressants, and antiepileptics. However, a subset of patients often experiences suboptimal therapeutic responses or severe adverse reactions. Therefore, emerging treatments are emphasizing a combination of pharmacological and non-pharmacological approaches to enhance neuropathic pain management. We provide a comprehensive review of past literature, which aims to aim both the mechanisms and clinical interventions for pathological neuropathic pain following spinal cord injury, offering novel insights for basic science research and clinical practice in spinal cord injury treatment.

The dual role of microglia in neuropathic pain after spinal cord injury: Detrimental and protective effects

Spinal cord injury (SCI) is a debilitating condition that is frequently accompanied by neuropathic pain, resulting in significant physical and psychological harm to a vast number of individuals globally. Despite the high prevalence of neuropathic pain following SCI, the precise underlying mechanism remains incompletely understood. Microglia are a type of innate immune cell that are present in the central nervous system (CNS). They have been observed to have a significant impact on neuropathic pain following SCI. This article presents a comprehensive overview of recent advances in understanding the role of microglia in the development of neuropathic pain following SCI. Specifically, the article delves into the detrimental and protective effects of microglia on neuropathic pain following SCI, as well as the mechanisms underlying their interconversion. Furthermore, the article provides a thorough overview of potential avenues for future research in this area.

Electroacupuncture exerts prolonged analgesic and neuroprotective effects in a persistent dental pain model induced by multiple dental pulp injuries: GABAergic interneurons-astrocytes interaction

Pain within the trigeminal system, particularly dental pain, is poorly understood. This study aimed to determine whether single or multiple dental pulp injuries induce persistent pain, its association with trigeminal central nociceptive pathways and whether electroacupuncture (EA) provides prolonged analgesic and neuroprotective effects in a persistent dental pain model. Models of single dental pulp injury (SDPI) and multiple dental pulp injuries (MDPI) were used to induce trigeminal neuropathic pain. The signs of dental pain-related behavior were assessed using the mechanical head withdrawal threshold (HWT). Immunofluorescence and western blot protocols were used to monitor astrocyte activation, changes in apoptosis-related proteins, and GABAergic interneuron plasticity. SDPI mice exhibited an initial marked decrease in HWT from days one to 14, followed by progressive recovery from days 21 to 42. From days 49 to 70, the HWT increased and returned to the control values. In contrast, MDPI mice showed a persistent decrease in HWT from days one to 70. MDPI increased glial fibrillary acidic protein (GFAP) and decreased glutamine synthetase (GS) and glutamate transporter-1 (GLT1) expression in the Vi/Vc transition zone of the brainstem on day 70, whereas no changes in astrocytic markers were observed on day 70 after SDPI. Increased expression of cleaved cysteine-aspartic protease-3 (cleaved caspase-3) and Bcl-2-associated X protein (Bax), along with decreased B-cell lymphoma/leukemia 2 (Bcl-2), were observed at day 70 after MDPI but not after SDPI. The downregulation of glutamic acid decarboxylase (GAD65) expression was observed on day 70 only after MDPI. The effects of MDPI-induced lower HWT from days one to 70 were attenuated by 12 sessions of EA treatment (days one to 21 after MDPI). Changes in astrocytic GFAP, GS, and GLT-1, along with cleaved caspase-3, Bax, Bcl-2, and GAD65 expression observed 70 days after MDPI, were reversed by EA treatment. The results suggest that persistent dental pain in mice was induced by MDPI but not by SDPI. This effect was associated with trigeminal GABAergic interneuron plasticity along with morphological and functional changes in astrocytes. EA exerts prolonged analgesic and neuroprotective effects that might be associated with the modulation of neuron-glia crosstalk mechanisms.

Electroacupuncture-Modulated MiR-106b-5p Expression Enhances Autophagy by Targeting Beclin-1 to Promote Motor Function Recovery After Spinal Cord Injury in Rats

OBJECTIVE

Electroacupuncture (EA) has a definite effect on the treatment of spinal cord injuries (SCIs), but its underlying molecular mechanism remains unclear. Meanwhile, MiR106b-5p is an autophagy- and apoptosis-related microribonucleic acid, but whether it regulates the progression of autophagy and apoptosis in SCIs is yet undetermined. As such, this study aimed to elucidate the involvement of miR-106b-5p in the EA treatment of an SCI.

METHODS

The miR-106b-5p level was detected by quantitative real-time polymerase chain reaction. In vitro, SH-SY5Y cells were transfected with miR-106b-5p mimics or inhibitors to regulate the miR-106b-5p expression, while in vivo, SCI rats were treated with EA for 7 days at the bilateral Zusanli (ST36) and Jiaji (EX-B2) acupoints. The motor function was evaluated using the Basso-Beattie-Bresnahan (BBB) criteria. Further, autophagic vacuoles, pathological damage, and neuronal cell morphology were observed by transmission electron microscopy, as well as by hematoxylin and eosin and Nissl staining, respectively.

RESULTS

The miR-106b-5p level, which can interact directly with Beclin-1 by influencing its expression, as well as the expressions of P62, Caspase-3, and Bax, was upregulated after an SCI, but it decreased after EA. Moreover, the ratio of LC3-II to LC3-I was upregulated after EA. EA can enhance autophagy, reduce neuronal apoptosis, and minimize motor dysfunction and histopathological deficits after an SCI. More importantly, however, all the above effects induced by EA can be reversed after an injection of miR-106-5p agomir to produce an overexpression of miR-106b-5p.

CONCLUSION

EA treatment could downregulate miR-106b-5p to alleviate SCI-mediated injuries by promoting autophagy and inhibiting apoptosis.

Abnormal expression and role of MicroRNA-214-3p/SLC8A1 in neonatal Hypoxic-Ischaemic encephalopathy

Neonatal hypoxic-ischaemic encephalopathy (HIE) refers to brain damage caused by intra-uterine distress and asphyxia/hypoxia during the perinatal and neonatal periods. MicroRNA (MiR)-214-3p plays a critical role in cell growth and apoptosis. The aim of this study was to investigate the expression and role of miR-214-3p in neonatal HIE development, and to explore the underlying mechanisms. The expression of miR-214-3p was significantly down-regulated, while that of Slc8a1, a direct target of miR-214-3p, was significantly up-regulated, in the brain tissue of neonatal HIE rats. The over-expression of miR-214-3p promoted the proliferation and inhibited the apoptosis of neurones, while its down-regulation had the opposite effect. Our results indicate that miR-214-3p expression was down-regulated in neonatal HIE rats, and the up-regulation of miR-214-3p expression protected against HIE development by inhibiting neuronal apoptosis.

Efficacy of different acupuncture therapies on postherpetic neuralgia: A Bayesian network meta-analysis

Background

Postherpetic neuralgia (PHN) is a common, complex, and refractory type of neuropathic pain. Several systematic reviews support the efficacy of acupuncture and related treatments for PHN. Nevertheless, the efficacy of various acupuncture-related treatments for PHN remains debatable.

Objective

We aimed to assess the efficacy and safety of acupuncture-related treatments for PHN, identify the most effective acupuncture-related treatments, and expound on the current inadequacies and prospects in the applications of acupuncture-related therapies.

Methods

We searched PubMed, Cochrane Central Register of Controlled Trials, Embase, Web of Science, Google Scholar, four Chinese databases (China National Knowledge Infrastructure, China Biomedical, Chongqing VIP, and Wan Fang databases), clinical research registration platform (World Health Organization International Clinical Trial Registration platform, China Clinical Trial Registration Center) for relevant studies. We also examined previous meta-analyses; gray literature; and reference lists of the selected studies. We then evaluated the risk of bias in the included studies and performed a Bayesian multiple network meta-analysis.

Results

We included 29 randomized controlled trials comprising 1,973 patients, of which five studies showed a high risk of bias. The pairwise meta-analysis results revealed that the efficacy of all acupuncture-related treatments for pain relief related to PHN was significantly better than antiepileptics. The network meta-analysis results showed that pricking and cupping plus antiepileptics were the most effective treatment, followed by electroacupuncture (EA) plus antiepileptics for pain relief in patients with PHN. EA plus antiepileptics ranked the best regarding reduced Pittsburgh Sleep Quality Index (PSQI) and Self-Rating Depression Scale (SDS) scores in patients with PHN. No results were found regarding the total response rate or quality of life in this study. Acupuncture-related treatments showed a lower incidence of adverse events than that of antiepileptics.

Conclusion

Acupuncture-related therapies are potential treatment options for PHN and are safe. Pricking and cupping plus antiepileptics, are the most effective acupuncture-related techniques for pain relief, while EA plus antiepileptics is the best acupuncture-related technique for improving PHN-related insomnia and depression symptoms. However, owing to the limitations of this study, these conclusions should be cautiously interpreted, and future high-quality studies are needed.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021226422, identifier CRD42021226422.

Acupuncture for neuropathic pain: A meta-analysis of randomized control trials

Background

Neuropathic pain (NP) is expected to increase due to the high risk of global population aging. Acupuncture has a definite clinical effect on NP. Therefore, a systematic review and meta-analysis were conducted to evaluate the effect on pain intensity and safety of acupuncture in patients with NP.

Methods

An encompassing search of specific authoritative databases in English, from their inception to 2022, was performed. The databases were as follows: Scopus, Ovid EMBASE, Ovid Cochrane Database of Systematic Reviews, Ovid Cochrane Central Register of Controlled Trials, Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations, and Daily. All the randomized controlled trials regarding the acupuncture treatment of NP will be included. Methodological quality assessment of the included trials was assessed based on the risk of bias from the Cochrane handbook. A meta-analysis was performed for the main outcomes. In addition, sensitivity analysis, subgroup analysis, and funnel plot were also carried out.

Results

A total of 16 studies with 1,021 patients with NP were evaluated in a systematic review. According to the results of the overall meta-analysis in eight RCTs with 338 participants, the acupuncture group was better than the control group in improving changes in pain intensity (SMD -0.59, 95% CI: -0.95 to -0.23, P = 0.001). In subgroup analysis, five trials indicated that acupuncture was more effective in improving changes in pain intensity than sham acupuncture (SMD -0.54, 95% CI: -0.95 to -0.13, P = 0.01), two trials evaluated the effect on changes in pain intensity in the comparison of acupuncture and conventional treatments, no significant difference existed (SMD -0.61, 95% CI: -1.83 to 0.61, P = 0.33), and one trial compared acupuncture with blank control evaluating the effect of changes in pain intensity with a significant difference. Eleven studies mentioned the safety conditions and acupuncture-induced AEs were mild and reversible. Both the sensitivity analysis and funnel plot analysis showed that the meta-analysis was stable and irreversible without publication bias. The GRADE was rated as "very low."

Conclusion

The acupuncture group had higher effectiveness than sham intervention or blank control for changes in pain intensity, but there is no significant difference between acupuncture and conventional treatments in treating NP. The acupuncture-induced adverse events were mild and reversible. However, the interpretation of our results should be performed cautiously due to the low methodological quality of selected publications.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022306461.

Potential mechanisms of acupuncture for neuropathic pain based on somatosensory system

Neuropathic pain, caused by a lesion or disease of the somatosensory system, is common and distressing. In view of the high human and economic burden, more effective treatment strategies were urgently needed. Acupuncture has been increasingly used as an adjuvant or complementary therapy for neuropathic pain. Although the therapeutic effects of acupuncture have been demonstrated in various high-quality randomized controlled trials, there is significant heterogeneity in the underlying mechanisms. This review aimed to summarize the potential mechanisms of acupuncture on neuropathic pain based on the somatosensory system, and guided for future both foundational and clinical studies. Here, we argued that acupuncture may have the potential to inhibit neuronal activity caused by neuropathic pain, through reducing the activation of pain-related ion channels and suppressing glial cells (including microglia and astrocytes) to release inflammatory cytokines, chemokines, amongst others. Meanwhile, acupuncture as a non-pharmacologic treatment, may have potential to activate descending pain control system via increasing the level of spinal or brain 5-hydroxytryptamine (5-HT), norepinephrine (NE), and opioid peptides. And the types of endogenously opioid peptides was influenced by electroacupuncture-frequency. The cumulative evidence demonstrated that acupuncture provided an alternative or adjunctive therapy for neuropathic pain.

A bibliometric of research trends in acupuncture for spinal cord injury: Quantitative and qualitative analyses

Introduction

Spinal cord injury (SCI) is a severe disease of the central nervous system with a very high disability rate that seriously affects the daily life of patients. Acupuncture is one of the rehabilitation therapies that has shown significant efficacy in treating post-SCI complications such as motor disorders, neuropathic pain, and neurogenic bladder. Current studies have focused on the effectiveness and mechanisms of acupuncture for SCI, but no studies are available to analyze the bibliometrics of publications related to this area.

Methods

Publications related to acupuncture for SCI were retrieved from the Web of Science Core Collection for quantitative and qualitative analyses. The quantitative analysis was unfolded in the following six main areas: annual publications, countries, institutions, authors, sources, and keywords. The qualitative analysis section screened out publications with high annual citation rates and categorized them according to the study content.

Results

There were 213 relevant publications, more than half of which were journal articles. The number of publications showed a fluctuating upward trend. China and the United States were hub countries for related publications and had extensive cooperation with other countries. The most relevant author was Yuanshan Zeng from Sun Yat-sen University, China. The efficacy and mechanism of acupuncture for neuropathic pain after SCI was the first research hotspot in this field, and electroacupuncture was the most widely used technique. In the past 5 years, the mechanism of acupuncture to improve the local microenvironment of SCI and promote nerve regeneration had become a new research trend. At the same time, acupuncture had been gradually applied to various complications after SCI and in veterinary medicine.

Conclusion

The findings suggest that research on acupuncture for SCI is still flourishing, and more research on electroacupuncture for promoting nerve repair and regeneration after SCI will be available in the future.

Electroacupuncture-Regulated miR-34a-3p/PDCD6 Axis Promotes Post-Spinal Cord Injury Recovery in Both In Vitro and In Vivo Settings

Electroacupuncture (EA) could enhance neuroregeneration and posttraumatic conditions; however, the underlying regulatory mechanisms remain ambiguous. PDCD6 (programmed cell death 6) is an established proapoptotic regulator which is responsible for motoneuronal death. However, its potential regulatory role in post-spinal cord injury (SCI) regeneration has remained largely unknown. Further investigations are warranted to clarify the involvement of PDCD6 post-SCI recovery and the underlying mechanisms. In our study, based on bioinformatics prediction, we found that miR-34a-3p might be an upstream regulator miRNA for PDCD6, which was subsequently validated through combined utilization of the qRT-PCR, western blot, and dual-luciferase reporter system. Our in vitro results showed that miR-34a-3p might promote the in vitro differentiation of neural stem cell (NSC) through suppressing PDCD6 and regulating other important neural markers such as fibroblast growth factor receptor 1 (FGFR1), MAP1/2 (MAP kinase kinases 1/2), myelin basic protein (MBP), βIII-tubulin Class III β-tubulin (βIII tubulin), and glial fibrillary acidic protein (GFAP). Notably, in the post-SCI rat model, exogenous miR-34a-3p agomir obviously inhibited the expression of PDCD6 at the protein level and promoted neuronal proliferation, motoneurons regeneration, and axonal myelination. The restorations at cellular level might contribute to the improved hindlimbs functions of post-SCI rats, which was manifested by the Basso-Beattie-Bresnahan (BBB) locomotor test. The impact of miR-34a-3p was further promoted by EA treatment in vivo. Conclusively, this paper argues that a miR-34a-3p/PDCD6 axis might be a candidate therapeutic target for treating SCI and that the therapeutic effect of EA is driven through this pathway.

Electroacupuncture promotes nerve regeneration and functional recovery in rats with spinal cord contusion through the coordinate interaction of CD4 and BDNF

To explore the effect of electroacupuncture on spinal cord injury (SCI) involving immune-related factors and regeneration-related factors in rats. The model of spinal cord contusion was established by PCI 3000 instrument. Two types of acupuncture points were selected for electroacupuncture treatment on rats. The rats were tested once a week, and the fiber remodeling was detected by magnetic resonance imaging. Transcriptome sequencing was performed on spinal scar samples. Using Python to write code, statistical analysis and bioinformatics analysis of the correlation between transcriptome sequencing data and fiber reconstruction results are carried out. Lastly, the expression of CD4 and brain-derived neurotrophic factor (BDNF) in spinal cord scar was verified by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Electroacupuncture exhibited a positive effect on the recovery of motor function in rats after SCI. Bioinformatics analysis found a direct interaction between CD4 and BDNF. Transcriptome sequencing and PCR results verified that electroacupuncture significantly reduced the expression of CD4, and increased significantly the expression of BDNF, simultaneously corresponding to nerve regeneration in rats with SCI. Our results showed that electroacupuncture intervention in SCI rats improves neural behavior via inhibiting the expression of CD4 and increasing the expression of BDNF.

Neurological recovery and antioxidant effect of erythropoietin for spinal cord injury: A systematic review and meta-analysis

Background

To critically evaluate the neurological recovery effects and antioxidant effects of erythropoietin (EPO) in rat models of spinal cord injury (SCI).

Methods

The PubMed, EMBASE, MEDLINE, ScienceDirect, and Web of Science were searched for animal experiments applying EPO to treat SCI to January 2022. We included studies which examined neurological function by the Basso, Beattie, and Bresnahan (BBB) scale, as well as cavity area and spared area, and determining the molecular-biological analysis of antioxidative effects by malondialdehyde (MDA) levels in spinal cord tissues. Meta-analysis were performed with Review Manager 5.4 software.

Results

A total of 33 studies were included in this review. The results of the meta-analysis showed that SCI rats receiving EPO therapy showed a significant locomotor function recovery after 14 days compared with control, then the superiority of EPO therapy maintained to 28 days from BBB scale. Compared with the control group, the cavity area was reduced [4 studies, weighted mean difference (WMD) = −16.65, 95% CI (−30.74 to −2.55), P = 0.02] and spared area was increased [3 studies, WMD =11.53, 95% CI (1.34 to 21.72), P = 0.03] by EPO. Meanwhile, MDA levels [2 studies, WMD = −0.63 (−1.09 to −0.18), P = 0.007] were improved in the EPO treatment group compared with control, which indicated its antioxidant effect. The subgroup analysis recommended 5,000 UI/kg is the most effective dose [WMD = 4.05 (2.23, 5.88), P < 0.0001], although its effect was not statistically different from that of 1,000 UI/kg. Meanwhile, the different rat strains (Sprague-Dawley vs. Wistar), and models of animals, as well as administration method (single or multiple administration) of EPO did not affect the neuroprotective effect of EPO for SCI.

Conclusions

This systematic review indicated that EPO can promote the recovery of the locomotor function of SCI rats. The mechanism exploration of EPO needs to be verified by experiments, and then carefully designed randomized controlled trials are needed to explore its neural recovery effects.

The etiological roles of miRNAs, lncRNAs, and circRNAs in neuropathic pain: A narrative review

Background

Non‐coding RNAs (ncRNAs) are involved in neuropathic pain development. Herein, we systematically searched for neuropathic pain‐related ncRNAs expression changes, including microRNAs (miRNAs), long non‐coding RNAs (lncRNAs), and circular non‐coding RNAs (circRNAs).

Methods

We searched two databases, PubMed and GeenMedical, for relevant studies.

Results

Peripheral nerve injury or noxious stimuli can induce extensive changes in the expression of ncRNAs. For example, higher serum miR‐132‐3p, ‐146b‐5p, and ‐384 was observed in neuropathic pain patients. Either sciatic nerve ligation, dorsal root ganglion (DRG) transaction, or ventral root transection (VRT) could upregulate miR‐21 and miR‐31 while downregulating miR‐668 and miR‐672 in the injured DRG. lncRNAs, such as early growth response 2‐antisense‐RNA (Egr2‐AS‐RNA) and Kcna2‐AS‐RNA, were upregulated in Schwann cells and inflicted DRG after nerve injury, respectively. Dysregulated circRNA homeodomain‐interacting protein kinase 3 (circHIPK3) in serum and the DRG, abnormally expressed lncRNAs X‐inactive specific transcript (XIST), nuclear enriched abundant transcript 1 (NEAT1), small nucleolar RNA host gene 1 (SNHG1), as well as ciRS‐7, zinc finger protein 609 (cirZNF609), circ_0005075, and circAnks1a in the spinal cord were suggested to participate in neuropathic pain development. Dysregulated miRNAs contribute to neuropathic pain via neuroinflammation, autophagy, abnormal ion channel expression, regulating pain‐related mediators, protein kinases, structural proteins, neurotransmission excitatory–inhibitory imbalances, or exosome miRNA‐mediated neuron–glia communication. In addition, lncRNAs and circRNAs are essential in neuropathic pain by acting as antisense RNA and miRNA sponges, epigenetically regulating pain‐related molecules expression, or modulating miRNA processing.

Conclusions

Numerous dysregulated ncRNAs have been suggested to participate in neuropathic pain development. However, there is much work to be done before ncRNA‐based analgesics can be clinically used for various reasons such as conservation among species, proper delivery, stability, and off‐target effects.

Electroacupuncture Alleviates Neuropathic Pain through Regulating miR-206-3p Targeting BDNF after CCI

Background

Electroacupuncture (EA) has benefits for neuropathic pain. However, the underlying mechanisms are still unknown. The current study explores the underlying mechanisms of EA in neuropathic pain of chronic constriction injury (CCI) rats. Material/Methods. Overall, 126 Sprague-Dawley (200-250 g) rats were divided into nine groups randomly: the sham-operated, CCI, CCI+EA, CCI+sham EA, CCI+NS, CCI+AAV-NC, CCI+AAV-miR-206-3p, CCI+EA+NS, and CCI+EA+AAV-miR-206-3p groups. The animals were sacrificed 14 days postsurgery. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) tests were used to determine differences in neurobehavioral manifestations. qPCR, western blotting, and immunofluorescence (IF) were carried out to detect the expression levels of miR-206-3p, BDNF, BAX/Bcl-2, TNF-α, and IL-6. Nissl staining was measured to observe morphological changes in neurons. Transmission electron microscopy (TEM) was employed to evaluate microscopic changes in dorsal horn synapses.

Results

Hyperalgesia was reduced markedly by EA in the CCI model. The expression level of miR-206-3p was elevated, whereas the expression levels of BDNF, BAX/Bcl-2, TNF-α, and IL-6 were decreased in EA-treated CCI rats. However, a miR-206-3p inhibitor partially abrogated the analgesic effect of EA and resulted in poor behavioral performance and the BDNF, BAX/Bcl-2, TNF-α, and IL-6 expression was elevated as well.

Conclusions

EA can relieve neuropathic pain by regulating the miR-206-3p/BDNF pathway, thus exerting anti-inflammatory and antiapoptotic effect.

Glutamine Maintains Satellite Glial Cells Growth and Survival in Culture

Satellite glial cells (SGCs) tightly surround neurons and modulate sensory transmission in dorsal root ganglion (DRG). At present, the biological property of primary SGCs in culture deserves further investigation. To reveal the key factor for SGCs growth and survival, we examined the effects of different culture supplementations containing Dulbecco's Modified Eagle Medium (DMEM)/F12, DMEM high glucose (HG) or Neurobasal-A (NB). CCK-8 proliferation assay showed an increased proliferation of SGCs in DMEM/F12 and DMEM/HG, but not in NB medium. Bax, AnnexinV, and propidium iodide (PI) staining results showed that NB medium caused cell death and apoptosis. We showed that glutamine was over 2.5 mM in DMEM/F12 and DMEM/HG, whereas it was absence in NB medium. Interestingly, exogenous glutamine application significantly reversed the poor proliferation and cell death of SGCs in NB medium. These findings demonstrated that DMEM/F12 medium was optimal to get high-purity SGCs. Glutamine was the key molecule to maintain SGCs growth and survival in culture. Here, we provided a novel approach to get high-purity SGCs by changing the key component of culture medium. Our study shed a new light on understanding the biological property and modulation of glial cells of primary sensory ganglia.

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.

MiR-214-3p plays a protective role in diabetic neuropathic rats by regulating Nav1.3 and TLR4

This study aimed to investigate the functions of miR-214-3p in diabetic neuropathic rodents. The diabetic neuropathy was induced by intraperitoneal injection of streptozotocin (STZ) in rats, and miR-214-3p was delivered via tail vein injection of lentivirus. Hot or cold stimulus tests demonstrated that STZ induced thermal hyperalgesia. Neurophysiological measurements revealed that motor and sensory nerve conduction velocity and nerve blood flow were decreased in diabetic neuropathic rats. However, the STZ-induced hyperalgesia, and reduced nerve conduction velocity and nerve blood flow were all significantly reversed by miR-214-3p administration. HE staining, TUNEL, ELISA, and immunoblotting demonstrated that STZ led to obvious pathological lesion, cell apoptosis, and inflammation in dorsal root ganglion (DRG), evidenced by altered levels of apoptosis-related protein molecules and inflammatory factors, and activation of Toll-like receptor 4 (TLR4)/myeloid differentiation primary response gene 88/nuclear factor kappa B signaling. The pathological alterations in diabetic neuropathic rats in DRG were significantly ameliorated by miR-214-3p application. In addition, sodium channel protein type 3 subunit alpha isoform 1 (Nav1.3) and TLR4 were identified as targets of miR-214-3p via dual-luciferase reporter assay. MiR-214-3p may play its roles by downregulating Nav1.3 and TLR4. In summary, miR-214-3p alleviated diabetes-induced nerve injury, and pathological lesion, cell apoptosis, and inflammation in DRG by regulating Nav1.3 and TLR4 in STZ-induced rats. These findings may provide novel therapeutic targets for clinical treatment of diabetic neuropathy.

Tetrodotoxin, a Potential Drug for Neuropathic and Cancer Pain Relief?

Tetrodotoxin (TTX) is a potent neurotoxin found mainly in puffer fish and other marine and terrestrial animals. TTX blocks voltage-gated sodium channels (VGSCs) which are typically classified as TTX-sensitive or TTX-resistant channels. VGSCs play a key role in pain signaling and some TTX-sensitive VGSCs are highly expressed by adult primary sensory neurons. During pathological pain conditions, such as neuropathic pain, upregulation of some TTX-sensitive VGSCs, including the massive re-expression of the embryonic VGSC subtype Na_V1.3 in adult primary sensory neurons, contribute to painful hypersensitization. In addition, people with loss-of-function mutations in the VGSC subtype Na_V1.7 present congenital insensitive to pain. TTX displays a prominent analgesic effect in several models of neuropathic pain in rodents. According to this promising preclinical evidence, TTX is currently under clinical development for chemo-therapy-induced neuropathic pain and cancer-related pain. This review focuses primarily on the preclinical and clinical evidence that support a potential analgesic role for TTX in these pain states. In addition, we also analyze the main toxic effects that this neurotoxin produces when it is administered at therapeutic doses, and the therapeutic potential to alleviate neuropathic pain of other natural toxins that selectively block TTX-sensitive VGSCs.

Acupuncture alleviates chronic pain and comorbid conditions in a mouse model of neuropathic pain: the involvement of DNA methylation in the prefrontal cortex

ABSTRACT

Chronic pain reduces life quality and is an important clinical problem associated with emotional and cognitive dysfunction. Epigenetic regulation of DNA methylation is involved in the induction of abnormal behaviors and pathological gene expression. We examined whether acupuncture can restore epigenetic changes caused by chronic pain, and identified the underlying mechanisms in neuropathic pain mice. Acupuncture treatment for 6 months (3 days/week) improved mechanical/cold allodynia and the emotional/cognitive dysfunction caused by left partial sciatic nerve ligation (PSNL)-induced neuropathic pain. The effects of acupuncture were associated with global DNA methylation recovery in the prefrontal cortex (PFC). Analysis of DNA methylation patterns in PFC indicated that 1364 overlapping genes among 4442 and 4416 methylated genes in the PSNL vs sham and PSNL vs acupuncture points groups, respectively, were highly associated with the DNA methylation process. Acupuncture restored the reduced expression of 5-methylcytosine, methyl-cytosine-phospho-guanine binding protein 2, and DNA methyltransferase family enzymes induced by PSNL in PFC. Methylation levels of Nr4a1 and Chkb associated with mitochondrial dysfunction were decreased in PFC of the PSNL mice, and increased by acupuncture. By contrast, high expression of Nr4a1 and Chkb mRNA in PSNL mice decreased after acupuncture. We also found that acupuncture inhibited the expression of Ras pathway-related genes such as Rasgrp1 and Rassf1. Finally, the expression of Nr4a1, Rasgrp1, Rassf1, and Chkb mRNA increased in the neuronal cells treated with Mecp2 small interfering RNA. These results suggest that acupuncture can relieve chronic pain-induced comorbid conditions by altering DNA methylation of Nr4a1, Rasgrp1, Rassf1, and Chkb in the PFC.

Fire Acupuncture versus conventional acupuncture to treat spasticity after stroke: A systematic review and meta-analysis

BACKGROUND

Post-stroke spasm is currently a complex clinical problem that remains to be resolved. Due to its excellent efficacy and few side effects, clinicians have used fire acupuncture to treat post-stroke spasticity in China.

OBJECTIVES

The purpose of this study was to evaluate the clinical efficacy of fire acupuncture compared with conventional acupuncture to treat post-stroke spasms and provide a detailed summary of the commonly used acupoints.

METHODS

Eight databases (MEDLINE/PubMed, Web of Science, the Cochrane database, EMBASE, CBM, CNKI, WanFang, and VIP) were searched for randomized controlled trials (RCTs) published from database inception through August 30, 2020. RCTs that compared fire acupuncture with conventional acupuncture as a treatment intervention for patients with spasticity after stroke were included. Revman 5.3 software was used to calculate risk ratios (RR) and standard mean differences (SMD) with 95% confidence intervals (CI). Methodological evaluation or critical appraisal of the included articles was assessed using RoB-2.

RESULTS

Sixteen studies with a total of 1,118 patients were included. Although according to the standards of the Rob 2.0 tool, most studies are considered to have some problems. Comprehensive analysis of the results revealed a consistent trend indicating several advantages of using fire needles compared to conventional acupuncture in treating post-stroke spasms, including the effective rate, recovery rate, and improvement of multiple scales represented by MAS. Concerning secondary outcomes, using the scales of FMA, BI, or NDS in this random model meta-analysis, fire acupuncture exhibited better performance compared to acupuncture [SMD = 2.27, 95%CI [1.40,3.13 (random-effects model) ], [SMD = 1.46,95% CI [1.03,1.90 (random-effects model)], and [SMD = 0.90, 95%CI [0.44,1.35 (random-effects model)], respectively, with moderately high heterogeneity. When the effective rate was used as an outcome in the subgroup analysis, fire needles performed better than conventional acupuncture with respect to damage to the upper or lower limbs, and the thickness and depth of acupuncture. When the modified Ashworth scale (MAS) was used as the outcome, and the damage occurred in the lower extremity, the acupuncture depth exceeded 15mm, or the duration of stroke was longer than six months, the fire needles did not perform better than conventional acupuncture, [SMD = 0.01, 95%CI [-0.47,0.48 (fix-effects model)], [SMD = 0.21 [-0.51,0.93(random-effects model)], and [SMD = 0.76, 95%CI [-0.08,1.60 (random-effects model)], respectively. The acupoints identified with the highest frequencies in this study were Yang-meridian, including LI11-Quchi (nine times), LI4-Hegu (seven times), and ST36-Zusanli (five times). Moreover, no serious adverse effects were reported in any of the studies included in this analysis.

CONCLUSIONS

Despite several limitations, this was the first meta-analysis to focus on the treatment of post-stroke spasticity using fire needle acupuncture compared with conventional acupuncture. Our results confirmed that fire needles could provide a better clinical effect than conventional acupuncture, which will help standardize fire needle treatment strategies for post-stroke spasms.

miR-495 reduces neuronal cell apoptosis and relieves acute spinal cord injury through inhibiting PRDM5

This study aims to investigate the role of miR-495 in neuronal cell apoptosis after acute spinal cord injury (ASCI). The ASCI rat model was established and the Basso, Beattie, and Bresnahan (BBB) score was assessed. miR-495, PR domain containing 5 (PRDM5), and Bcl-2 expressions were measured by qRT-PCR or western blotting. Neuronal cell line PC-12 was subjected to hypoxia condition to simulate the in vitro ASCI model. PC-12 cell apoptosis was measured by flow cytometry, and the interaction between miR-495 and PRDM5 was confirmed by dual luciferase reporter assay. Results showed that BBB score was significantly decreased in ASCI rats compared with sham rats. miR-495 expression was down-regulated in spinal cord tissue of ASCI rats and hypoxia-induced PC-12 cells, and PRDM5 protein level was up-regulated in spinal cord tissue of ASCI rats and hypoxia-induced PC-12 cells. miR-495 overexpression could reduce apoptosis of PC-12 cells, and up-regulated anti-apoptosis protein Bcl-2 protein level. Moreover, PRDM5 was a target of miR-495, and mRNA and protein levels of PRDM5 were negatively regulated by miR-495. miR-495 overexpression could reduce the hypoxia-induced PC-12 cell apoptosis, while PRDM5 overexpression abolished this inhibiting effect. The agomir-495 was injected into ASCI rats, and Bcl-2 protein level and BBB score were increased, but the PRDM5 overexpression reversed these results. Overall, we concluded that miR-495 could inhibit neuronal cell apoptosis and relieve acute spinal cord injury through inhibiting PRDM5.

Circ_DHRS3 positively regulates GREM1 expression by competitively targeting miR-183-5p to modulate IL-1β-administered chondrocyte proliferation, apoptosis and ECM degradation

BACKGROUND

Osteoarthritis (OA) is a chronic inflammatory disease caused by degenerative changes of articular cartilage, involving in the expression changes of special circular RNAs (circRNAs). This study aimed to explore the role of circ_DHRS3 in OA cell models and provide a potential mechanism.

METHODS

OA cell models were constructed using human chondrocytes with Interleukin-1 beta (IL-1β) treatment. The expression of circ_DHRS3, microRNA (miR)-183-5p and Gremlin 1 (GREM1) mRNA was detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation was identified using 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) assay. Cell apoptosis was investigated using flow cytometry assay. The protein levels of proliferation- and apoptosis-related proteins were quantified by western blot. The levels of extracellular matrix (ECM)-associated proteins were quantified by western blot to assess ECM degradation. The relationship between miR-183-5p and circ_DHRS3 or GREM1 was predicted and then verified by dual-luciferase reporter assay.

RESULTS

Circ_DHRS3 expression was elevated in OA cartilage tissues and IL-1β-treated chondrocytes. Circ_DHRS3 was resistant to RNase R and Actinomycin D. Circ_DHRS3 knockdown promoted chondrocyte proliferation inhibited by IL-1β, and alleviated IL-1β-induced apoptosis and ECM degradation, which were reversed by the inhibition of miR-183-5p, a target of circ_DHRS3. MiR-183-5p restoration also enhanced IL-1β-blocked cell proliferation, and relieved IL-1β-induced cell apoptosis and ECM degradation, while GREM1 (a target of miR-183-5p) overexpression abolished the effects of miR-183-5p restoration. Moreover, circ_DHRS3 regulated GREM1 expression by targeting miR-183-5p.

CONCLUSION

Circ_DHRS3 mediated IL-1β-administered chondrocyte proliferation, apoptosis and ECM degradation by positively regulating GREM1 expression via competitively targeting miR-183-5p.

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.

The transcription factor Foxd3 induces spinal cord ischemia-reperfusion injury by potentiating microRNA-214-dependent inhibition of Kcnk2

Spinal cord injury after surgical repair of the thoracic or thoracoabdominal aorta is a devastating complication that is associated with pathological changes, including inflammation, edema, and nerve cell damage. Recently, microRNA (miRNA)-modulated control of spinal cord injury has been actively investigated. This study aims to clarify the regulatory effect of miR-214-mediated inhibition of Kcnk2 following spinal cord ischemia-reperfusion injury (SCII) and the possible underlying mechanisms. SCII was induced in rats by occluding the aortic arch followed by reperfusion. Gain-of-function and loss-of-function experiments were conducted to explore the modulatory effects of Foxd3, miR-214 and Kcnk2 on PC12 cells under hypoxia/reoxygenation (H/R) conditions. MiR-214 and Kcnk2 were poorly expressed, while Foxd3 was highly expressed in the rat spinal cord tissues and H/R-treated PC12 cells. Kcnk2 overexpression enhanced the viability and inhibited the apoptosis of the H/R-treated PC12 cells. Notably, Foxd3 activated miR-214, and miR-214 targeted Kcnk2. In addition, upregulation of Kcnk2 or knockdown of Foxd3 promoted the cell viability and reduced the apoptosis of the H/R-treated PC12 cells. Overall, our study identified a novel mechanism of Foxd3/miR-214/Kcnk2 involving SCII, suggesting that either Foxd3 or miR-214 may be a novel target for the treatment of SCII.

Combination Therapy With Hyperbaric Oxygen and Erythropoietin Inhibits Neuronal Apoptosis and Improves Recovery in Rats With Spinal Cord Injury

BACKGROUND

Apoptosis plays an important role in various diseases, including spinal cord injury (SCI). Hyperbaric oxygen (HBO) and erythropoietin (EPO) promote the recovery from SCI, but the relationship between apoptosis and the combination therapeutic effect is not completely clear.

OBJECTIVE

The purpose of this study was to investigate the effects of HBO and EPO on SCI and the mechanisms that underlie their therapeutic benefits.

DESIGN

The study was designed to explore the effects of HBO and EPO on SCI through a randomized controlled trial.

METHODS

Sixty young developing female Sprague-Dawley rats were randomly divided into groups of 12 rats receiving sham, SCI, HBO, EPO, or HBO plus EPO. The SCI model was modified with the Allen method to better control consistency. HBO was performed for 1 hour per day for a total of 21 days, and EPO was given once per week for a total of 3 weeks. Both methods were performed 2 hours after SCI. Locomotor function was evaluated with the 21-point Basso-Beattie-Bresnahan Locomotor Rating Scale, an inclined-plane test, and a footprint analysis. All genes were detected by Western blotting and immunohistochemistry. The level of cell apoptosis was determined by Hoechst staining.

RESULTS

The results showed that HBO and EPO promoted the recovery of locomotor function in the hind limbs of rats by inhibiting the apoptosis of neurons. During this period, the expression of B-cell lymphoma/leukemia 2 protein (Bcl-2) increased significantly, whereas the expression of Bcl-2-associated X protein (Bax) and cleaved caspase 3 decreased significantly, indicating the inhibition of apoptosis. Meanwhile, the expression of G protein-coupled receptor 17 decreased, and that of myelin basic protein increased, suggesting that there may be a potential connection between demyelination and neuronal apoptosis.

LIMITATIONS

The limitations of the study include deviations in the preparation of SCI models; lack of reverse validation of molecular mechanisms; absence of in vitro cell experiments; and only one time point after SCI was studied.

CONCLUSIONS

HBO and EPO treatments are beneficial for SCI, especially when the 2 therapies are combined.

Protective effect of 4-Methoxy benzyl alcohol on the neurovascular unit after cerebral ischemia reperfusion injury

OBJECTIVE

Cerebral ischemia reperfusion injury (CIRI) is a major cause of ischemic stroke (IS) deterioration. Considering the intricate mechanism of the pathological process of CIRI, most drugs only work on one target. The neurovascular unit (NVU) puts forward the concept of neuroprotection from nerve protection to global stabilization. The NVU plays an important role in maintaining the brain microenvironment. This would promote neuronal survival and overall neurological recovery, which would likely lead to the reduction of mortality rate. Previous studies have shown that 4-methoxy benzyl alcohol (4-MA) ameliorated neurological score and cerebral infarct volume and reduced the concentration of Evans blue (EB) in brain tissue. In this research, we investigated the effects of 4-MA on NVU microenvironment improvement in rats impaired by middle cerebral artery occlusion/reperfusion (MCAO/R).

METHODS

First, we established a rat model of middle cerebral artery occlusion (MCAO) so as to use Western blot analysis, immunofluorescence and transmission electron microscopy (TEM) evaluating the NVU's protection of 4-MA. Then we established a primary cortical neuron model of oxygen glucose deprivation and re-oxygenation (OGD/R) with the objective of identifying whether 4-MA exhibited anti-oxidant and anti-apoptotic effects on neurons.

RESULTS

NVU ultra structural changes were improved by 4-MA. Immunofluorescence and western blot showed that 4-MA protected NVUs through enhancement of the expression of the symbolic neuronal proteins Microtubule Associated Protein-2(MAP-2), and attenuation of protein expression of Asy symbolic protein Glial Fibrillary Acidic Protein(GFAP). Furthermore, in the OGD/R model of I/R injury in vitro, 4-MA significantly increased Superoxide dismutase(SOD), Nitric Oxide(NO), B-cell lymphoma-2(Bcl-2), decreased Bcl-2-Associated X(Bax) and increased Bcl-2/Bax.

CONCLUSION

4-MA can play the role of anti-ischemic stroke drug by ameliorating the microenvironment of NVUs while its neuroprotective effects will contribute towards the inhibition of the antioxidant and anti-apoptotic activities.

Electroacupuncture Alleviates Ischemic Brain Injury by Inhibiting the miR-223/NLRP3 Pathway

Background

Electroacupuncture (EA) has been commonly used to treat stroke in China. However, the underlying mechanism remains largely unknown. The present study investigated the neuroprotective effects of EA in middle cerebral artery occlusion (MCAO) rats and elucidated the possible anti-inflammatory mechanisms.

Material/Methods

In this study, modified neurological severity scoring (mNSS) was used to assess neurological deficits, and TTC staining and brain water content were measured to evaluate the degree of brain damage. HE staining, Nissl staining, and TUNEL staining were employed to evaluate apoptotic neuronal death. Molecular biological methods were used to measure the levels of miR-233, NLRP3, caspase-1, IL-1β, and IL-18 in the peri-infarct cortex.

Results

Our results showed that EA treatment significantly decreased the neurological deficit score and infarct volume of MCAO rats. The level of miR-223 was increased, while the levels of NLRP3, caspase-1, IL-1β, and IL-18 were decreased in the peri-infarct cortex of EA-treated MCAO rats. However, the neuroprotective effect of EA was partially blocked by antagomir-223.

Conclusions

These data suggest that EA treatment can alleviate neuroinflammation by inhibiting the miR-223/NLRP3 pathway, thus playing a neuroprotective role in MCAO in rats.

MicroRNA in Acupuncture Studies: Does Small RNA Shed Light on the Biological Mechanism of Acupuncture?

MicroRNAs (miRNAs) are the main regulators of diverse physiological processes. Recently, miRNAs have emerged as significant players related to the effect of acupuncture although the biological mechanisms connecting the function of these miRNAs with the effect of acupuncture are not well understood. In animal models of various diseases, such as neurological disease, cardiovascular disease, myopathy, and pain, a number of miRNAs were altered after administration of electroacupuncture or manual acupuncture. Nonetheless, there are a limited number of studies published so far. This paper reviewed and discussed whether miRNAs could elucidate potential biological mechanism of acupuncture in the future studies.

Mechanisms of Acupuncture Therapy for Simple Obesity: An Evidence-Based Review of Clinical and Animal Studies on Simple Obesity

Simple obesity is a worldwide epidemic associated with rapidly growing morbidity and mortality which imposes an enormous burden on individual and public health. As a part of Traditional Chinese Medicine (TCM), acupuncture has shown the positive efficacy in the management of simple obesity. In this article, we comprehensively review the clinical and animal studies that demonstrated the potential mechanisms of acupuncture treatment for simple obesity. Clinical studies suggested that acupuncture regulates endocrine system, promotes digestion, attenuates oxidative stress, and modulates relevant molecules of metabolism in patients of simple obesity. Evidence from laboratory indicated that acupuncture regulates lipid metabolism, modulates inflammatory responses, and promotes white adipose tissue browning. Acupuncture also suppresses appetite through regulating appetite regulatory hormones and the downstream signaling pathway. The evidence from clinical and animal studies indicates that acupuncture induces multifaceted regulation through complex mechanisms and moreover a single factor may not be enough to explain the beneficial effects against simple obesity.

Fire Needle Acupuncture Regulates Wnt/ERK Multiple Pathways to Promote Neural Stem Cells to Differentiate into Neurons in Rats with Spinal Cord Injury

BACKGROUND & OBJECTIVE

NSCs therapy is considered one of the most potential methods for spinal cord injury (SCI).

METHODS

We build the SCI model rats to investigate the therapeutic effect of fire needle acupuncture in improving the locomotor function of SCI rats and its possible mechanism. BBB scale was used for the motor ability of rats. The expression of Nestin, NSE, Gal-C, and GFAP was detected by immunohistochemistry. Wnt, GSK3β, β-catenin, ERK1/2, CyclinD1, and ngn1 were detected by western blot and PCR. The BBB score of both model group (1.20±0.94, 3.12±0.67, 5.34±1.57, 7.12±1.49) and fire needle group (1.70±0.58, 4.50±1.63, 7.53±2.41, 9.24±0.63) gradually increased after SCI. Furthermore, at d10 and d14, the fire needle group showed a significantly high score compared with that in model group at the same time (P<0.05). Fire needle increased Nestin, NSE, and Gal-C expression inhibited GFAP expression after SCI. Also, fire needle could up-regulate Wnt3a, GSK3β, β-catenin, and ngn1, and down-regulate ERK1/2, cyclinD1 gene and protein expression.

CONCLUSION

In conclusion, fire needle could improve lower limb locomotor function of SCI rats. Also, fire needles could promote endogenous NSCs proliferation differentiating into neurons, and the mechanism might be mediated by promoting the activation of Wnt/β-catenin and inhibiting the overexpression of ERK.

Anti-Apoptotic Mechanisms of Acupuncture in Neurological Diseases: A Review

Apoptosis, known as programmed cell death, plays a significant role in the pathogenesis of neurological diseases. Most of these diseases can be obviously alleviated by means of acupuncture treatment. Current research studies have shown that the efficacy of acupuncture to these medical conditions is closely associated with the anti-apoptotic potentials. Mainly based on the acupuncture's anti-apoptotic efficacy in prevalent neurological disorders, including cerebral ischemia-reperfusion injury, Alzheimer's disease, depression or stress related-modes, spinal cord injuries, etc., this review comes to a conclusion that the anti-apoptotic effect of acupuncture treatment for neurological diseases, evidently reflected through Bcl-2, Bax or caspase expression change, results from regulating mitochondrial or autophagic dysfunction as well as reducing oxidative stress and inflammation. The possible mechanisms of acupuncture's anti-apoptotic effect are associated with a series of downstream signaling pathways and the up-regulated expression of neurotrophic factors. It is of great importance to illuminate the exact mechanisms of acupuncture treatment for neurological dysfunctions.

Modulation of Acupuncture on Cell Apoptosis and Autophagy

Acupuncture has been historically practiced to treat medical disorders by mechanically stimulating specific acupoints. Despite its well-documented efficacy, its biological basis largely remains elusive. Recent studies suggested that cell apoptosis and autophagy might play key roles in acupuncture therapy. Therefore, we searched PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI), aiming to find the potential relationship between acupuncture and cell apoptosis and autophagy. To provide readers with objective evidence, some problems regarding the design method, acupoints selection, acupuncture intervention measure, and related diseases existing in 40 related researches were shown in this review. These findings demonstrated that acupuncture has a potential role in modulating cell apoptosis and autophagy in animal models, suggesting it as a candidate mechanism in acupuncture therapy to maintain physiologic homeostasis.