Activation of Subcutaneous Mast Cells in Acupuncture Points Triggers Analgesia

Influence of acupuncture intensity on analgesic effects in AA rat models

Objective

To investigate the influence of acupuncture lifting-thrusting frequency and amplitude on the analgesic effects, and its correlation with mast cell degranulation.

Methods

Acute adjuvant arthritis (AA) rat models were employed. Robot-arm aided lifting-thrusting acupuncture therapy was conducted with various frequencies (ranging from 0.5 to 4 Hz) and amplitudes (ranging from 0.5 to 2.0 mm). The rats' pain thresholds were measured multiple times before and after the therapy, and the analgesic effects were evaluated using the pain threshold recovery rate (PTRR), a normalized index. The mast cell degranulation rate (MCdR) at the acupoint was calculated, and a correlation analysis between PTRR and MCdR was performed.

Results

Acupuncture therapy partially restored the pain threshold affected by arthritis. The analgesic effects were influenced by stimulus frequency and amplitude, with best outcomes occurring at an intermediate optimal frequency of 1.0 Hz and amplitude of 1.0-1.5 mm. Similarly, the MCdR peaked at the optimal frequency and amplitude.

Conclusion

Our animal experiment suggests that optimal analgesic effects can be achieved with stimulation at an optimal intensity. This intensity-effect correlation appears to originate from mast cell activation rates under different mechanical stimulus.

Mast Cells as a Component of Spermatogonial Stem Cells' Microenvironment

The formation of mature spermatozoa originates from spermatogonial stem cells (SSCs) located near the basement membrane of the seminiferous tubules. This developmental process, known as spermatogenesis, is tightly regulated to ensure continuous sperm production. A critical aspect of this regulation is the balance between SSC differentiation and self-renewal, which is directed by various factors guiding SSCs in either of these two directions. The SSC niche, defined functionally rather than anatomically, includes all factors necessary for SSC maintenance. These factors are produced by cells surrounding the SSC niche, collectively creating the microenvironment of the seminiferous tubules. Coordination between the cells in this microenvironment is essential for the proper function of the SSC niche and successful spermatogenesis. Testicular mast cells (MCs) significantly influence the regulation of this niche, as they contain various biologically active substances that regulate a wide range of physiological processes and contribute to different pathological conditions affecting fertility. This review explores the effects of testicular MCs on SSCs, their role in regulating spermatogenesis under normal and pathological conditions, and their interactions with other components of the testicular microenvironment, with a focus on their potentially critical impact on spermatogenesis and male fertility.

Acupuncture at Weizhong (BL40) attenuates acetic acid-induced overactive bladder in rats by regulating brain neural activity through the modulation of mast cells and tibial nerves

OBJECTIVE

The present study evaluated the effects of deep acupuncture at Weizhong acupoint (BL40) on bladder function and brain activity in a rat model of overactive bladder (OAB), and investigated the possible mechanisms around the acupuncture area that initiate the effects of acupuncture.

METHODS

Adult female Sprague-Dawley rats were randomly divided into six groups, comprising a control group, model group, group treated with deep acupuncture at BL40, group treated with shallow acupuncture at BL40, group treated with acupuncture at non-acupoint next to BL40, and group treated with acupuncture at Xuanzhong (GB39). Urodynamic evaluation was used to observe the urination, and functional magnetic resonance imaging was used to observe the brain activation. The mechanism of acupuncture at BL40 in regulating bladder function was explored by toluidine blue staining and enzyme-linked immunosorbent assay, and the mechanism was verified by stabilizing mast cells (MCs) or blocking tibial nerve.

RESULTS

Deep acupuncture at BL40 significantly increased the intercontraction interval in OAB rats and enhanced the mean amplitude of low frequency fluctuation of primary motor cortex (M1), periaquaductal gray matter (PAG), and pontine micturition center (PMC). It also increased the zero-lag functional connectivity between M1 and PAG and between PAG and PMC. Shallow acupuncture at BL40 and acupuncture at non-acupoint or GB39 had no effect on these indexes. Further studies suggested that deep acupuncture at BL40 increased the number and degranulation rate of MCs as well as the contents of 5-hydroxytryptamine, substance P, and histamine in the tissues around BL40. Blocking the tibial nerve by lidocaine injection or inhibiting MC degranulation by sodium cromoglycate injection obstructed the effects of acupuncture on restoring urinary function and modulating brain activation in OAB rats.

CONCLUSION

Deep acupuncture at BL40 may be more effective for inhibiting OAB by promoting degranulation of MCs around the acupoint and stimulating tibial nerve, thereby regulating the activation of the brain area that controls the lower urinary tract. Please cite this article as: Liu X, Zhang CY, Du XY, Li SS, Wang YQ, Zheng Y, Deng HZ, Fang XQ, Li JY, Wang ZQ, Xu SF, Mi YQ. Acupuncture at Weizhong (BL40) attenuates acetic acid-induced overactive bladder in rats by regulating brain neural activity through the modulation of mast cells and tibial nerves. J Integr Med. 2024; Epub ahead of print.

Effects of acupuncture needle modification on acupuncture analgesia

OBJECTIVE

The analgesic effect of acupuncture has been widely accepted. Nevertheless, the mechanism behind its analgesic effect remains elusive, thus impeding the progress of research geared toward enhancing the analgesic effect of acupuncture. This paper investigated the role of acupuncture needle surface textures on acupuncture's analgesic effect by creating four experimental acupuncture needles with different patterns of surface augmentation.

METHODS

Four types of acupuncture needles with different surface textures (the lined needle, circle needle, sandpaper needle, and threaded needle) were designed. Additionally, the force/torque measurement system used a robot arm and mechanical sensor to measure the force on the needle during insertion and manipulation. To perform acupuncture analgesia experiments, four experimental acupuncture needles and a normal needle were inserted into the Zusanli (ST36) acupoint of rats with inflammatory pain. By comparing the force and torque and the analgesic efficacy of the different acupuncture needles, these experiments tested the role of acupuncture needle body texture on acupuncture analgesia.

RESULTS

The analgesic effects of different acupuncture needle body textures varied. Specifically, the force required to penetrate the skin with the lined needle was not greater than that for the normal needle; however, the needle with inscribed circles and the sandpaper-roughened needle both required greater force for insertion. Additionally, the torque of the lined needle reached 2 × 10-4 N·m under twisting manipulation, which was four times greater the torque of a normal needle (5 × 10-5 N·m). Furthermore, the lined needle improved pain threshold and mast cell degranulation rate compared to the normal needle.

CONCLUSION

Optimizing the texture of acupuncture needles can enhance acupuncture analgesia. The texture of our experimental acupuncture needles had a significant impact on the force needed to penetrate the skin and the torque needed to manipulate the needle; it was also linked to variable analgesic effects. This study provides a theoretical basis for enhancing the analgesic efficacy of acupuncture through the modification of needles and promoting the development of acupuncture therapy. Please cite this article as: Sun MZ, Wang X, Li YC, Liu YH, Yu Y, Ren LJ, Gu W, Yao W. Effects of acupuncture needle modification on acupuncture analgesia. J Integr Med. 2024; Epub ahead of print.

Acupuncture therapy in autoimmune diseases: A narrative review

We provide a narrative review of experimental and clinical evidence for the effect of acupuncture in autoimmune diseases, based on randomized controlled studies, systematic review and meta-analyses, published between the years 2000-2023. Acupuncture in experimental models of rheumatoid arthritis (RA), multiple sclerosis, psoriasis, ulcerative colitis (UC) downregulated inflammatory cytokine expression, increased IL-10 expression, improved Treg cell differentiation, and also modulated macrophage polarization in RA and UC models. The anti-inflammatory effect of acupuncture in autoimmune disorders has been demonstrated to involve vagal-adrenal and cholinergic anti-inflammatory pathways. The analgesic effect of acupuncture involves both peripheral and central anti-nociceptive mechanisms. Randomized controlled studies support the use of acupuncture in rheumatoid arthritis, fibromyalgia, Crohn's disease and in Sjogren's syndrome. Some evidence indicates that acupuncture may be beneficial as a symptomatic treatment for multiple sclerosis, myasthenia gravis, psoriasis and ankylosing spondylitis.

CD39 activities in the treated acupoints contributed to the analgesic mechanism of acupuncture on arthritis rats

Our previous work had identified that at the acupuncture point (acupoint), acupuncture-induced ATP release was a pivotal event in the initiation of analgesia. We aimed to further elucidate the degradation of ATP by CD39. Acupuncture was administered at Zusanli acupoint on arthritis rats, and pain thresholds of the hindpaws were determined. Pharmacological tools or adeno-associated viruses were administered at the acupoints to interfere with targeting signals. Protein expression was determined with qRT-PCR, WB, or immunofluorescent labeling. Cultured keratinocytes, HaCaT line, were subjected to hypotonic shock to simulate needling stimulation. Extracellular ATP and adenosine levels were quantified using luciferase-luciferin assay and ELISA, respectively. Acupuncture-induced prompt analgesia was impaired by inhibiting CD39 activities to prevent the degradation of ATP to AMP but was mimicked by using CD39 agonists. Acupuncture-induced ATP accumulation exhibited synchronous changes. Similarly, acupuncture analgesia was hindered by suppressing CD73 to prevent the conversion of AMP to adenosine. Furthermore, the acupuncture effect was replicated by agonism at P2Y2Rs but inhibited by antagonism at them. Acupuncture upregulated CD73 and P2Y2Rs but not CD39. Immunofluorescent labeling demonstrated that keratinocytes were a primary site for these proteins. Shallow acupuncture also demonstrated antinociception. In vitro tests showed that hypotonic shock induced HaCaT cells to release ATP and adenosine, which was impaired by suppressing CD39 and CD73, respectively. Finally, agonism at P2Y2Rs promoted ATP release and [Ca2+]i rise. CD39 at the acupoints contributes to the analgesic mechanism of acupuncture. It may facilitate adenosine signaling in conjunction with CD73 or provide an appropriate ATP milieu for P2Y2Rs. Skin tissue may be one of the scenes for these signalings.

No signs of mast cell involvement in long-COVID: A case-control study

Long-COVID caused by SARS-CoV-2 infection has significant and increasing effects on human health worldwide. Although a unifying molecular or biological explanation is lacking, several pathophysiological mechanisms have been proposed. Involvement of mast cells-evolutionary old "multipurpose" innate immune cells-was reported recently in studies of acute infection and post-acute-COVID-19 syndrome. Mast cell activity has been suggested in long-COVID. In this case-control study, we compared data from 24 individuals with long-COVID (according to the NICE criteria) and 24 age- and sex-matched healthy individuals with a history of SARS-CoV-2 infection without developing sequelae. Serum levels of the proteases beta-tryptase (TPSB2) and carboxypeptidase (CPA3), which are mast cell specific, were measured using immunoassays. The values were compared between the two groups and correlated to measures of physical exertional intolerance. TPSB2 and CPA3 levels were median (range) 26.9 (2.0-1000) and 5.8 (1.5-14.0) ng/mL, respectively, in the long-COVID group. The corresponding values in the control group were 10.9 (2.0-1000) (p = 0.93) and 5.3 (3.5-12.9) ng/mL (p = 0.82). No significant correlations between TPSB2 or CPA3 levels and scores on the ten physical subscales of SF-36, 3.1-3.10 were revealed. We found no significant differences in the levels of mast cell activation markers TPSB2 and CPA3 between the long-COVID and control groups and no correlations with proxy markers of exercise intolerance. Mast cell activation does not appear to be part of long-term pathogenesis of long-COVID, at least in the majority of patients.

Acupuncture combined with opioid for treatment of lung cancer-related pain: A systematic review and meta-analysis

BACKGROUND

Many individuals diagnosed with lung cancer suffer from tremendous pain, and it is crucial to implement more effective measures to assist these patients in alleviating their pain. The present study utilizes a meta-analysis to evaluate the safety and efficacy of acupuncture combined with opioids for treating lung cancer-related pain in patients.

METHODS

We have searched 8 electronic databases: The Cochrane Library, PubMed, Embase, Web of Science, China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang Database, and SinoMed. We included all randomized controlled trials of acupuncture combined with opioids for lung cancer-related pain in adults. We observed the main outcome indicators, including pain relief rates, numeric rating scale scores, and adverse events. Two researchers independently conducted literature screening, literature data extraction, and assessment of bias risk in the literature quality. Any disagreements were resolved through discussions between the 2 researchers or consultations with a third researcher. The risk of bias in the included studies was assessed using the revised risk of bias assessment tool. The overall quality of evidence for each outcome was evaluated using Grading of Recommendations, Assessment, Development and Evaluations.

RESULTS

We retrieved 812 lung cancer patients from 11 trials. The study showed that compared to opioids alone, the combination of acupuncture and opioids significantly reduced numeric rating scale scores, increased pain relief rates, and decreased the occurrence of side effects.

CONCLUSION

The current evidence indicates that combining acupuncture with opioid analgesics is superior to using opioid analgesics alone for managing lung cancer-related pain. Additionally, this combination therapy has fewer adverse reactions.

Investigation of local stimulation effects of embedding PGLA at Zusanli (ST36) acupoint in rats based on TRPV2 and TRPV4 ion channels

Introduction

Acupoint Catgut Embedding (ACE) is an extended and developed form of traditional acupuncture that serves as a composite stimulation therapy for various diseases. However, its local stimulation effects on acupoints remain unclear. Acupuncture can activate mechanically sensitive calcium ion channels, TRPV2 and TRPV4, located on various cell membranes, promoting Ca2+ influx in acupoint tissues to exert effects. Whether ACE can form mechanical physical stimulation to regulate these channels and the related linkage effect requires validation.

Methods

This study investigates the influence of TRPV2 and TRPV4 ion channels on the local stimulation effects of ACE by embedding PGLA suture at the Zusanli (ST36) acupoint in rats and using TRPV2 and TRPV4 inhibitors. Flow cytometry, immunofluorescence, Western blot, and Real-time quantitative PCR were employed to detect intracellular Ca2+ fluorescence intensity, the expression of macrophage (Mac) CD68 and mast cell (MC) tryptase, as well as the protein and mRNA expression of TRPV2 and TRPV4 in acupoint tissues after PGLA embedding.

Results

The results indicate that ACE using PGLA suture significantly increases the mRNA and protein expression of TRPV2 and TRPV4, Ca2+ fluorescence intensity, and the expression of Mac CD68 and MC tryptase in acupoint tissues, with these effects diminishing over time. The increasing trends are reduced after using inhibitors, particularly when both inhibitors are used simultaneously. Furthermore, correlation analysis shows that embedding PGLA suture at the ST36 acupoint regulates Mac and MC functions through Ca2+ signaling involving not only TRPV2 and TRPV4 but multiple pathways.

Discussion

These results suggest that embedding PGLA suture at the ST36 acupoint generates mechanical physical stimulation and regulates TRPV2 and TRPV4 ion channels, which couple with Ca2+ signaling to form a linkage effect that gradually weakens over time. This provides new reference data for further studies on the stimulation effects and clinical promotion of ACE.

Acupuncture and moxibustion intervention in functional dyspepsia: Gastric and duodenal regulation

Functional dyspepsia (FD) is a brain-gut interaction disorder located in the stomach and duodenum, which has complex pathophysiological mechanisms, and there is no effective treatment for FD. Acupuncture and moxibustion have been proven to have definite and significant efficacy on FD. Focusing on the affected area and combined with the potential pathophysiology of FD, here we discuss the possible mechanisms of acupuncture and moxibustion in treating FD to guide future clinical and experimental research. We argue that the pathological causes of FD can be roughly divided into gastrointestinal dysfunction, duodenal low-grade inflammation, visceral hypersensitivity, and duodenal intestinal barrier and microbial imbalance. Correspondingly, the possible mechanisms of acupuncture and moxibustion in treating FD are elucidated from the perspective of how they improve gastric accommodation, regulate gastrointestinal motility, reduce gastric visceral sensitivity, regulate eosinophil-mast cell axis, inhibit low-grade inflammatory responses, and possibly regulate intestinal microbial homeostasis and duodenal barrier function through the microbiota-gut-brain axis. Although some evidence is still lacking, acupuncture remains a promising treatment for FD. In the future, it is necessary to conduct additional clinical and experimental research on acupuncture and moxibustion in treating FD to further explore their effects and mechanisms.

Peripheral mast cells derive the effects of acupuncture in Parkinson's disease

This research investigates the peripheral mechanisms of acupuncture in treating Parkinson's disease (PD), a progressive neurodegenerative disorder marked by motor impairments. While the central mechanisms of acupuncture have been extensively studied, our focus lies in the peripheral mechanisms at the acupoints, the sites of acupuncture signal initiation. Employing a PD model, we analyzed the local responses to acupuncture stimulation at these points. Our key finding was a significant elevation in both the number and activity of mast cells (MCs) in the peripheral tissues following acupuncture. Intriguingly, pre-treatment with an MC stabilizer diminished the acupuncture's therapeutic effects on PD symptoms. Similarly, local anesthesia with lidocaine at the acupoints attenuated the symptom improvement typically observed with acupuncture. Meanwhile, the augmentation of MC activity induced by acupuncture was significantly impeded by cromolyn, an MC stabilizer, but remained unaffected by lidocaine. This finding suggests that MC activity is a more upstream regulator of acupuncture effects compared to nerve conduction. This study provides groundbreaking insights into the initiation and transmission of acupuncture signals, highlighting the significant role of peripheral MC modulation in PD treatment.

Acupoint Stimulation for Pain Control in Enhanced Recovery After Surgery: Systematic Review and Meta-Analysis

Introduction: Postoperative pain control is a challenge in enhanced recovery after surgery (ERAS). The current study reviewed the efficacy and safety of incorporating acupoint stimulation for postoperative pain control in ERAS. Methods: Ten databases for relevant randomized controlled trials (RCTs) published in English or Mandarin Chinese were searched from 1997 to 2022. The quality of each article was appraised using the Cochrane Collaboration Risk of Bias Criteria and the modified Jadad Scale. The primary outcome was pain control, measured using the visual analog scale 24 h after surgery. Results: Eleven trials met the eligibility criteria and were included in the study. Acupoint stimulation was found more effective than control treatments in terms of pain intensity (standardized mean difference [SMD] -0.94; 95% confidence interval [CI] -1.35 to -0.53), analgesic drug consumption (SMD -1.87; 95% CI -2.98 to -0.75), postoperative nausea (PON; SMD 0.31; 95% CI 0.13 to 0.73), postoperative vomiting (POV; SMD 0.57; 95% CI 0.11 to 2.92), and PON and POV (PONV; SMD 0.29; 95% CI 0.16 to 0.53). The Zusanli (ST36) and Neiguan (PC6) were the most-used acupoints in the included trials (8/11). The reported adverse reaction was only one case of bruising. Discussion: Acupoint stimulation improved pain control in patients undergoing ERAS more than control treatments. The findings provide an evidence-based premise for incorporating acupoint stimulation into ERAS strategies. More rigorous RCTs are needed in the future.

A randomized controlled study on acupuncture for peri-operative pain after open radical prostatectomy

OBJECTIVES

To evaluate the advantages of adding acupuncture to standard postoperative pain management for open radical prostatectomy (RP).

MATERIALS AND METHODS

A randomized controlled trial (1:1:1) comparing routine postoperative analgesic care (control [CON]) vs the addition of press tack needle acupuncture (ACU) or press tack placebo acupressure (SHAM) for pain management after open RP was performed. A total of 126 patients were enrolled between February 2020 and April 2021. After open RP, the CON group received standard postoperative analgesia, the ACU group received long-term acupuncture with press tacks at specific points (P-6, Shenmen and SP-6) along with standard analgesia, and the SHAM group received placebo press tacks at the same acupuncture points alongside standard analgesia. The primary endpoint was postoperative pain measured on a numeric rating scale, the NRS-11, calculated as the area under the curve. The cumulative use of routine postoperative analgesics, time to first defaecation, and quality of life were analysed using the Kruskal-Wallis rank sum test, Fisher's exact test, and Pearson's chi-squared test.

RESULTS

The ACU group reported significantly less postoperative pain compared to the SHAM (P = 0.007) and CON groups (P = 0.02). There were no significant difference in median (interquartile range) cumulative pain medication usage, time to first defaecation (CON: 37 [33, 44] h; SHAM: 37 [33, 42] h; ACU: 37 [33, 41] h; P > 0.9), or health status at discharge (EuroQol five-dimension, five-level general health assessment questionnaire: CON: 70 [65-83]; SHAM: 70 [60-80]; ACU: 70 [50-80]).

CONCLUSION

Incorporating acupuncture into postoperative pain management can improve patient postoperative outcomes.

Peripheral Mechanism of Cancer-Induced Bone Pain

Cancer-induced bone pain (CIBP) is a type of ongoing or breakthrough pain caused by a primary bone tumor or bone metastasis. CIBP constitutes a specific pain state with distinct characteristics; however, it shares similarities with inflammatory and neuropathic pain. At present, although various therapies have been developed for this condition, complete relief from CIBP in patients with cancer is yet to be achieved. Hence, it is urgent to study the mechanism underlying CIBP to develop efficient analgesic drugs. Herein, we focused on the peripheral mechanism associated with the initiation of CIBP, which involves tissue injury in the bone and changes in the tumor microenvironment (TME) and dorsal root ganglion. The nerve-cancer and cancer-immunocyte cross-talk in the TME creates circumstances that promote tumor growth and metastasis, ultimately leading to CIBP. The peripheral mechanism of CIBP and current treatments as well as potential therapeutic targets are discussed in this review.

Research trends on acupuncture for neuropathic pain: A bibliometric analysis from 1979 to 2023

BACKGROUND

Acupuncture has drawn increasing attention as a complementary and alternative therapy for neuropathic pain (NP). The present study aimed to summarize the current status and research trends on acupuncture for NP over the past several decades.

METHODS

The publications on acupuncture for NP in the database of Web of Science Core Collection from 1979 to 2023 were searched. VOSviewer (1.6.15) and CiteSpace software (5.5.R2) were applied to identify active authors, journals, countries and institutions, co-cited references and hot keywords.

RESULTS

A total of 642 publications were finally included, and the quantitative trend of annual publications on acupuncture for NP have shown overall upward from 1979 to 2023. Peoples R China was the most productive and influential country, while Kyung Hee University from South Korea was both the first in publications and citations. Fang JQ ranked the first productive author and Han JS was the first 1 among the co-cited authors. The first productive journal was Evidence-based Complementary and Alternative Medicine, while the first co-cited journal was Pain. The high-frequency keywords were divided into 9 clusters, and the frontier topic focused on "Chronic pain".

CONCLUSION

This present study visually showed the research status and trends of acupuncture for NP from 1979 to 2023 on the basis of bibliometric analysis, which may in some way help researcher discovery and explore some new research directions and ideas in the future.

NTPDase1-ATP-P2Y2Rs axis in the sciatic nerve contributes to acupuncture at "Zusanli" (ST36)-induced analgesia in ankle arthritis rats

BACKGROUND

The efficacy of acupuncture at Zusanli (ST36) in alleviating lower-limb pain is widely acknowledged in clinical practice, while its underlying mechanism remains incompletely elucidated. Our previous research had revealed that the prompt analgesia induced by needling-ST36 was accompanied by expression alterations in certain exco-nucleotidases within the sciatic nerve. Building upon this finding, the current work focused on NTPDase1, the primary ecto-nucleotidase in the human body, which converts ATP into AMP.

METHODS

A 20-min acupuncture was administered unilaterally at the ST36 on rats with acute ankle arthritis. The pain thresholds of the injured hind paws were determined. Pharmacological interference was carried out by introducing the corresponding reagents to the sciatic nerve. ATP levels around the excised nerve were measured using a luciferase-luciferin assay. Live calcium imaging, utilizing the Fura 2-related-F340/F380 ratio, was conducted on Schwann cells in excised nerves and cultured rat SCs line, RSC96 cells.

RESULTS

The analgesic effect induced by needling-ST36 was impaired when preventing ATP degradation via inhibiting NTPDase1 activities with ARL67156 or Ticlopidine. Conversely, increasing NTPDase1 activities with Apyrase duplicated the acupuncture effect. Similarly, preventing the conversion of AMP to adenosine via suppression of NT5E with AMP-CP hindered the acupuncture effect. Unexpectedly, impeded ATP hydrolysis ability and diminished NTPDase1 expression were observed in the treated group. Agonism at P2Y2Rs with ATP, UTP, or INS365 resulted in anti-nociception. Contrarily, antagonism at P2Y2Rs with Suramin or AR-C 118925xx prevented acupuncture analgesia. Immunofluorescent labeling demonstrated that the treated rats expressed more P2Y2Rs that were predominant in Schwann cells. Suppression of Schwann cells by inhibiting ErbB receptors also prevented acupuncture analgesia. Finally, living imaging on the excised nerves or RSC96 cells showed that agonism at P2Y2Rs indeed led to [Ca2+]i rise.

CONCLUSION

These findings strongly suggest that the analgesic mechanism of needling-ST36 on the hypersensation in the lower limb partially relies on NTPDase1 activities in the sciatic nerve. In addition to facilitating adenosine signaling in conjunction with NT5E, most importantly, NTPDase1 may provide an appropriate low-level ATP milieu for the activation of P2Y2R in the sciatic nerve, particularly in Schwann cells.

TRPA1 Ion Channel Mediates the Analgesic Effects of Acupuncture at the ST36 Acupoint in Mice Suffering from Arthritis

Purpose

Acupuncture (ACU) has been demonstrated to alleviate inflammatory pain. Mechanoreceptors are present in acupuncture points. When acupuncture exerts mechanical force, these ion channels open and convert the mechanical signals into biochemical signals. TRPA1 (T ransient receptor potential ankyrin 1) is capable of sensing various physical and chemical stimuli and serves as a sensor for inflammation and pain. This protein is expressed in immune cells and contributes to local defense mechanisms during early tissue damage and inflammation. In this study, we investigated the role of TRPA1 in acupuncture analgesia.

Patients and Methods

We injected complete Freund's adjuvant (CFA) into the mouse plantars to establish a hyperalgesia model. Immunohistochemistry and immunofluorescence analyses were performed to determine the effect of acupuncture on the TRPA1 expression in the Zusanli (ST36). We used TRPA1-/- mouse and pharmacological methods to antagonize TRPA1 to observe the effect on acupuncture analgesia. On this basis, collagenase was used to destroy collagen fibers at ST36 to observe the effect on TRPA1.

Results

We found that the ACU group vs the CFA group, the number of TRPA1-positive mast cells, macrophages, and fibroblasts at the ST36 increased significantly. In CFA- inflammatory pain models, the TRPA1-/- ACU vs TRPA1+/+ ACU groups, the paw withdrawal latency (PWL) and paw withdrawal threshold (PWT) downregulated significantly. In the ACU + high-, ACU + medium-, ACU + low-dose HC-030031 vs ACU groups, the PWL and PWT were downregulated, and in carrageenan-induced inflammatory pain models were consistent with these results. We further found the ACU + collagenase vs ACU groups, the numbers of TRPA1-positive mast cells, macrophages, and fibroblasts at the ST36 were downregulated.

Conclusion

These findings together imply that TRPA1 plays a significant role in the analgesic effects produced via acupuncture at the ST36. This provides new evidence for acupuncture treatment of painful diseases.

Exploring the serotonin-probiotics-gut health axis: A review of current evidence and potential mechanisms

Modulatory effects of serotonin (5-Hydroxytryptamine [5-HT]) have been seen in hepatic, neurological/psychiatric, and gastrointestinal (GI) disorders. Probiotics are live microorganisms that confer health benefits to their host. Recent research has suggested that probiotics can promote serotonin signaling, a crucial pathway in the regulation of mood, cognition, and other physiological processes. Reviewing the literature, we find that peripheral serotonin increases nutrient uptake and storage, regulates the composition of the gut microbiota, and is involved in mediating neuronal disorders. This review explores the mechanisms underlying the probiotic-mediated increase in serotonin signaling, highlighting the role of gut microbiota in the regulation of serotonin production and the modulation of neurotransmitter receptors. Additionally, this review discusses the potential clinical implications of probiotics as a therapeutic strategy for disorders associated with altered serotonin signaling, such as GI and neurological disorders. Overall, this review demonstrates the potential of probiotics as a promising avenue for the treatment of serotonin-related disorders and signaling of serotonin.

The involvement of transient receptor potential channels in mast cell activation by microbubbles

This study was to explore the activation of mast cells by microbubbles, with the focus on transient receptor potential (TRP) channels mediated degranulation and calcium influx. Bone marrow-derived mast cells (BMMCs) were primarily obtained from femurs in mice and induced differentiation for 4 weeks. After the purity identification, BMMCs were contacted by homogeneous microbubbles with the diameter of 1 mm for 1 h. β-hexosaminidase and histamine levels in supernatants were assessed by enzyme-linked immunosorbent assay (ELISA) and the CD63 expression was tested by flow cytometry. The intracellular calcium binding with Fluo-4 AM dyes in BMMCs was observed under the fluorescence microscope and the mean fluorescence intensity was quantitatively measured by flow cytometry. β-hexosaminidase release, histamine concentration, CD63 expression and calcium influx were significantly increased in BMMCs group upon microbubble stimulation compared to the control groups. After preconditioning with the available inhibitors and microbubble contact, only transient receptor potential vanilloid 1 (TRPV1) and TRPV4 inhibitors robustly suppressed the microbubble-induced degranulation. Likewise, the elevated fluorescence intensity of cytosolic calcium level was also significantly weaken. The results demonstrated microbubble stimulus effectively promoted BMMCs degranulation, which could be substantially restrained by inhibitors targeted for blocking TRPV1 or TRPV4 channel. The alternation of intracellular calcium level in BMMCs was consistent with the changes of degranulation capacity. It's suggested that the activation of BMMCs by microbubbles may involve specific TRP calcium dependent channels.

MicroRNAs as promising therapeutic agents: A perspective from acupuncture

MicroRNAs (miRNAs) are gaining recognition as potential therapeutic agents due to their small size, ability to target a wide range of genes, and significant role in disease progression. However, despite their promising potential, nearly half of the miRNA drugs developed for therapeutic purposes have been discontinued or put on hold, and none have advanced to phase III clinical trials. The development of miRNA therapeutics has faced obstacles such as difficulties in validating miRNA targets, conflicting evidence regarding competition and saturation effects, challenges in miRNA delivery, and determining appropriate dosages. These hurdles primarily arise from the intricate functional complexity of miRNAs. Acupuncture, a distinct, complementary therapy, offers a promising avenue to overcome these barriers, particularly by addressing the fundamental issue of preserving functional complexity through acupuncture regulatory networks. The acupuncture regulatory network consists of three main components: the acupoint network, the neuro-endocrine-immune (NEI) network, and the disease network. These networks represent the processes of information transformation, amplification, and conduction that occur during acupuncture. Notably, miRNAs serve as essential mediators and shared biological language within these interconnected networks. Harnessing the therapeutic potential of acupuncture-derived miRNAs can help reduce the time and economic resources required for miRNA drug development and alleviate the current developmental challenges miRNA therapeutics face. This review provides an interdisciplinary perspective by summarizing the interactions between miRNAs, their targets, and the three acupuncture regulatory networks mentioned earlier. The aim is to illuminate the challenges and opportunities in developing miRNA therapeutics. This review paper presents a comprehensive overview of miRNAs, their interactions with acupuncture regulatory networks, and their potential as therapeutic agents. By bridging the miRNA research and acupuncture fields, we aim to offer valuable insights into the obstacles and prospects of developing miRNA therapeutics.

Role of SIRT5 in the analgesic effectiveness of moxibustion at ST36 in mice with inflammatory pain

Sirtuine5 (SIRT5) is an important molecule involved in the pathology of inflammatory diseases. To investigate the impact of SIRT5 on the analgesic effectiveness of moxibustion, we established a complete Freund's adjuvant- (CFA-) induced inflammatory pain in mice model. Moxibustion was applied at the Zusanli (ST36) acupoint in mice with inflammatory pain. The analgesic effectiveness was evaluated by thermal hyperalgesia and mechanical allodynia tests in the right paws after CFA injection. The expression of inflammatory cytokines, including the pro-inflammatory factors IL-1β and TNF-α, and the anti-inflammatory factors IL-4 and TGF-β expressions, was evaluated using by ELISA. Furthermore, SIRT5 was evaluated by immunofluorescence and western blotting. The results showed that, compared with the CFA group, both thermal and mechanical pain thresholds increased with moxibustion and the SIRT5 inhibitor MC3482 intervention at ST36. Additionally, compared to the CFA-induced group, the inflammatory mediators, including IL-1β and TNF-α, decreased, while the anti-inflammatory cytokines IL-4 and TGF-β increased with moxibustion and MC3482 ST36 acupoint injection. Western blot results showed a decreased expression of SIRT5 at the ST36 site with moxibustion and MC3482 injection, compared to the CFA-induced group. SIRT5 expression in the right paw of mice injected with moxibustion and MC3482 was higher than that in the CFA-induced group. This study revealed that SIRT5 expression is involved in moxibustion analgesia and may be a potential mediator in the regulation of analgesia.

Aberrant parasympathetic responses in acupuncture therapy for restoring immune homeostasis

Acupuncture is an effective therapy used worldwide to treat various diseases, including infections, allergic disorders, autoimmune diseases, and immunodeficiency syndromes. Except for the hypothalamic-pituitary-adrenal axis, acupuncture exerts its regulatory effect mainly by producing autonomic reflexes, including somatic-sympathetic and somatic-parasympathetic reflexes. In this review, we discuss the updated progress of the cholinergic vagal efferent pathway, vagal-adrenal axis, local spinal sacral-parasympathetic pathway, and the somatotopic evocation of parasympathetic responses related to restoring immune homeostasis within acupuncture therapy. Targeting the parasympathetic reflex offers scientific instruction for the design of acupuncture protocols for immunological diseases, providing more specialized comprehensive treatment recommendations.

Graphical abstract:

http://links.lww.com/AHM/A49

Changes of local microenvironment and systemic immunity after acupuncture stimulation during inflammation: A literature review of animal studies

An increasing number of studies have demonstrated the underlying mechanisms by which acupuncture therapy mediates both local and systemic immunomodulation. However, the connection between alterations in the local microenvironment and the resulting change in systemic immunity remains unclear. In this review, we focus on cell-specific changes in local immune responses following acupuncture stimulation and their link to systemic immune modulation. We have gathered the most recent evidence for chemo- and mechano-reactive changes in endothelial cells, neutrophils, macrophages, and mast cells in response to acupuncture. Local signaling is then related to the activation of systemic neuro-immunity including the cholinergic, adrenal, and splenic nervous systems and pain-related neuromodulation. This review aims to serve as a reference for further research in this field.

A Biophysical Model for Cardiovascular Effects of Acupuncture-Underlying Mechanisms Based on First Principles

According to recent translations by medical professionals of the foundational texts of Chinese Medicine, the acupuncture channel system can be reconciled with the neurovasculature. From there, the underlying mechanisms of the effects of acupuncture can be drawn from established physiology and known physical laws. A large body of research has been carried out using cardiovascular markers to measure the effects of acupuncture. Three of these parameters are re-viewed and explored anew in detail. The focus is on changes in microcirculation, blood pressure, and heart rate variability. The physiological mechanisms accounting for the observed changes are proposed to be ascending vasodilatation, resetting of the baroreceptor reflex, and re-organization of heart beating patterns around intrinsically assigned attractor sets.

Song's Mast Cell Theory of Acupuncture

Professor. Jimei Song (1924–1987), from the Liaoning College of Traditional Medicine, first proposed the hypothesis that cutaneous mast cells (MCs) may be responsible for some of the phenomena associated with activation of meridians, acupoints, and De Qi in acupuncture. This was in 1977 and she subsequently published the first investigative report on human subjects. Supported by hundreds of extensive research reports later on, now Song's Mast Cell Theory of Acupuncture is one of the leading theories in acupuncture research. As a scientist and mother, Professor Song belonged to a special generation of female professionals in China. These women were living in a very unique and challenging era. Called “half of the sky” or “bourgeoisie intellectuals,” they faced unbearable difficulties in their lives and their work. The contribution of Professor Song to acupuncture is as significant as the contribution of Ms. Youyou Tu to Chinese herbal medicine. The difference is that Professor Song did not receive any award or significant recognition before she died in 1987. This review provides some background about her life, her contributions, and related publications, as well as a brief review of recent advances on MC mapping and acupuncture based on her MC theory.

Paper-Based Detection Device for Microenvironment Examination: Measuring Neurotransmitters and Cytokines in the Mice Acupoint

(1) Background: The medical practice of acupuncture involves the insertion of a specialized stainless needle into a specific body point, often called an acupoint, to initiate a perceived phenomenon of de-qi sensation. Therefore, the term “de-qi” describes bodily sensations experienced by the recipient during acupuncture, which may include feelings of soreness, heaviness, fullness, numbness, and migration. However, while acupuncture treatments reportedly result in acupoint activation and an increased release of neurotransmitters or cytokines, detecting these substances released into the acupoint microenvironment is often missed or delayed in clinical and basic practice. (2) Methods: To address this situation, we employed a paper-based enzyme-linked immunosorbent assay method to examine acupoint environmental changes using minute volumes of easily accessible acupoint fluids. (3) Results: Our results indicated that while levels of adenosine triphosphate (ATP), interleukin-1β, interleukin-6, glutamate, substance P, and histamine were all increased in the experimental group following electroacupuncture (EA) treatment, contrary results were observed in the sham EA and transient receptor potential vanilloid 1 (Trpv1^−/−) groups. Subsequently, TRPV1 and its associated molecules were augmented in mouse dorsal root ganglion, spinal cord, thalamus, and the somatosensory cortex, then examined by Western blotting and immunofluorescence techniques. Investigations revealed that these elevations were still unobserved in the sham EA or EA in the Trpv1^−/− groups. Furthermore, results showed that while administering ATP could mimic EA function, it could be reversed by the ATP P2 receptor antagonist, suramin. (4) Conclusions: Our data provide novel information, indicating that changes in neurotransmitter and cytokine levels can offer insight into acupuncture mechanisms and clinical targeting.