Moxibustion at ST36 alleviates pain in complete Freund's adjuvant-induced arthritic rats

Ccrl2-centred immune-related lncRNA-mRNA co-expression network revealed the local skin immune activation mechanism of moxibustion on adjuvant arthritis mice

BACKGROUND

Moxibustion is an important external therapy of traditional medicine that operates on some acupoints on the skin and is usually used for immune-related diseases. However, whether the immune function of the skin, especially the immune-related lncRNAs, contributes to the mechanism of moxibustion remains unclear.

METHODS

Adjuvant arthritis (AA) was induced by injection of Complete Freund's adjuvant (CFA) into the right hind paw of mice. Moxibustion was administered on the Zusanli (ST36) acupoint for 3 weeks. The alteration of foot volume and cytokine concentration in serum was used to evaluate the anti-inflammation effect of moxibustion. CD83 expression in the local skin of ST36 was measured by immunofluorescence staining. Transcriptome RNA sequencing (RNA-seq) and lncRNA-mRNA network analysis were performed to construct a moxibustion-induced Immune-related lncRNA-mRNA co-expression network. qRT-PCR was used to validate the RNA-seq data.

RESULTS

Moxibustion at ST36 relieved the foot swelling, decreased the TNF-α and IL-1β concentrations in serum, and obviously increased the CD83 expression at the local skin of ST36. A total of 548 differentially expressed lncRNAs and 520 linked mRNAs were screened out. The significantly and predominately enriched Go term was inflammatory and immune response, and the main pathways related to inflammatory and immune responses include Toll-like receptor, cytokine-cytokine receptor, and MAPK signaling. The immune-related lncRNA-mRNA co-expression network showed 88 lncRNAs and 36 mRNAs, and Ccrl2 is the central hub of this network.

CONCLUSION

Local immune activation is significantly triggered by moxibustion in ST36 of AA mice. The Ccrl2-centered immune-related lncRNA-mRNA co-expression network would be a promising target for decoding the mechanism of moxibustion for immune-related diseases.

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.

Transcriptome sequencing reveals core regulation modules and gene signatures of Zusanli acupoints in response to different moxibustion warm stimulation in adjuvant arthritis rat

Background

The efficacy of moxibustion in treating rheumatoid arthritis is recognized, but its molecular mechanism is still unclear. This study aimed to characterize the molecular map and potential key genes in the process of different moxibustion warm at Zusanli acupoint treatment of adjuvant arthritis (AA) model.

Methods

AA rat model was induced by complete Freund’s adjuvant (CFA) and then accessed by foot swelling and thermal hyperalgesia test. Transcriptome sequencing, series test of cluster (STC) and weighted gene co-expression network analysis (WGCNA) were used in this study.

Results

CFA-induced inflammation, foot swelling, and pain in AA rats were significantly improved by moxibustion warm. Differentially expressed genes (DEGs) were screened in nine different comparison groups and a total of 4535 DEGs were identified, and these DEGs were preferentially clustered in inflammatory and immune-related pathways, such as MAPK signaling pathway. Only 1 DEG of heat shock protein 90, alpha (cytosolic), class A member 1 (Hsp90aa1) was shared in comparison groups of model with moxibustion treatment. STC analysis also revealed that Hsp90aa1 was increased in AA model, but decreased after 37 °C moxibustion intervention, and constantly decreased after 42 °C moxibustion treatment. GO and KEGG pathway analysis revealed that these genes enriched in inflammatory and immune-related pathways. Moreover, WGCNA identified that violet module was positively correlated with model temperature while negatively correlated with control, and the paleturquoise module was positively correlated with model. The violet and paleturquoise module gene were significantly enriched in MAPK signaling pathway. Importantly, Hsp90aa1 also played a central role in the violet module by interacting with multiple proteins.

Conclusions

Moxibustion warm improved AA in rat, and we obtained the transcriptome profile and excavate a critical gene of Hsp90aa1, and provided insight into gene signatures for moxibustion warm at Zusanli acupoint in AA rat.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-022-00221-4.

The role of STIM1/ORAI1 channel in the analgesic effect of grain-sized moxibustion on inflammatory pain mice model

The therapeutic effect of grain-sized moxibustion (GS-Moxi) on inflammatory pain has been well recognized clinically, but the mechanism remains unclear. STIM1/ORAI1 is a sensible temperature channel, therefore; this study aimed to investigate the analgesic effect of GS-Moxi and the association with STIM1/ORAI1 expression. CFA-induced inflammatory pain model was established and was treated with GS-Moxi after 3 days of CFA injection. The behavioral test was measured after the GS-Moxi; then, serum was prepared for IL-1β, IL-6, and TNF-α, and the stimulated skin was used for measuring STIM1 and ORAI1 expression. The results indicated GS-Moxi had an analgesic effect on inflammatory pain and the heat variation was significant for the analgesia. GS-Moxi decreased the expression of IL-1β, IL-6, and TNF-α. Immunofluorescence and western blot analysis illustrated that heat change was associated with the stimulation of STIM1 and ORAI1. Suggesting that heat variation created by GS-Moxi could be crucial in this therapy and STIM1 and ORAI1 were potential enhancers in regulating analgesia of GS-Moxi.

Moxibustion Treatment for Knee Osteoarthritis: A Systematic Review and Meta-Analysis

To determine whether the administration of moxibustion is an effective treatment for knee osteoarthritis (KOA).We conducted a search of relevant articles using Medline, EMBASE, the Web of Science, and the Cochrane Library published before October 2015. The Western Ontario and McMaster Universities' Osteoarthritis Index (WOMAC scale) and the short form 36 questionnaire (SF-36 scale) were assessed. Evidence grading was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation system.Four studies containing 746 participants fulfilled the inclusion criteria in the final analysis. In terms of quality of life (QOL), the meta-analysis of 2 randomized clinical trials (RCTs) showed significantly effects of moxibustion only in bodily pain (BP) compared with those in the control group (n = 348; weighted mean difference [WMD], 4.36; 95% confidence intervals [CIs], 2.27-6.44; P < 0.0001; heterogeneity: χ = 1.53, P = 0.22, I = 34%) in all of the subcategories of the SF-36 scale, with moderate quality. The meta-analysis of the 2 included trials showed that there was not a statistically significant difference in the pain or function subscale for the WOMAC scale when the 2 groups were compared (n = 322; WMD, 17.63; 95% CI, -23.15-58.41; P = 0.40; heterogeneity: χ = 19.42, P < 0.0001, I = 95%), with low or moderate quality separately.The administration of moxibustion can to some extent alleviate the symptoms of KOA. More rigorous, randomized controlled trials are required in the future.

Transcutaneous Electrical Stimulation Increased Nitric Oxide-Cyclic GMP Release Biocaptured Over Skin Surface of Pericardium Meridian and Acupuncture Points in Humans

OBJECTIVES

The purpose of this study was to consecutively capture and quantify nitric oxide (NO) and cGMP, the second messenger of NO, over the skin surface of acupuncture points (acupoints), meridian line without acupoint, and non-meridian control regions of the Pericardium meridian (PC) in humans, and investigate their response to transcutaneous electrical nerve stimulation (TENS) . DESIGN, SETTING, AND MAIN OUTCOME MEASURES: Adhesive biocapture tubes were attached to the skin surface along PC regions and injected with 2-Phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl solution, an NO-scavenging compound, contacting the skin surface for 20 minutes each during 4 consecutive biocapture intervals. TENS (1.0 mA, 6 Hz, 1.0 msec duration) was applied over acupoints PC 8 and PC 3 during the 2nd biocapture for 20 min. Total nitrite and nitrate (NO(x)-), the stable metabolic products of NO, and cGMP in biocaptured samples were quantified using chemiluminescence and ELISA.

RESULTS

NO(x)- levels in the 1st biocapture over PC regions are almost two fold higher compared to subsequent biocaptures and are higher over PC acupoints versus non-meridian control region. Following TENS, NO(x)- concentrations over PC regions were significantly increased, and cGMP is predominantly released from the skin surface of PC acupoints.

CONCLUSIONS

TENS induces elevations of NO-cGMP concentrations over local skin region with a high level at acupoints. The enhanced signal molecules improve local circulation, which contributes to beneficial effects of the therapy.

Gene Expression Profiles at Moxibustioned Site (ST36): A Microarray Analysis

As a major alternative therapy in Traditional Chinese Medicine, it has been demonstrated that moxibustion could generate a series of molecular events in blood, spleen, and brain, and so forth. However, what would happen at the moxibustioned site remained unclear. To answer this question, we performed a microarray analysis with skin tissue taken from the moxibustioned site also Zusanli acupoint (ST36) where 15-minute moxibustion stimulation was administrated. The results exhibited 145 upregulated and 72 downregulated genes which responded immediately under physiological conditions, and 255 upregulated and 243 downregulated genes under pathological conditions. Interestingly, most of the pathways and biological processes of the differentially expressed genes (DEGs) under pathological conditions get involved in immunity, while those under physiological conditions are involved in metabolism.

A Qualitative Study of the Experiences of Patients with Knee Osteoarthritis Undergoing Moxibustion

Objective

To explore and understand how patients with knee osteoarthritis (OA) experience moxibustion.

Method

This qualitative research was conducted as part of a larger clinical trial of the effectiveness of moxibustion for the treatment of knee OA by qualitative content analysis. Sixteen patients with mild knee OA who participated in a 12-week moxibustion treatment as part of the trial were interviewed using open-ended questions.

Results

The participants recognised knee OA as a normal ageing process that caused physical and emotional discomfort in daily life. Regardless of any adverse effects of moxibustion, most of the participants were interested in continuous moxibustion treatment as a long-term management strategy and for general health.

Conclusions

This study suggests that moxibustion can be helpful in managing symptoms related to knee OA. Patients’ attitudes towards moxibustion can affect the treatment result and those who prefer it want to continue the treatment for a long time because they understand that knee OA is a chronic condition which needs continuous care. However, practitioners need to pay more attention to those who are very enthusiastic because they tend to endure treatment-related adverse events in their desire for better effects.

Analgesic Effects of Indirect Moxibustion on An Experimental Rat Model of Osteoarthritis in the Knee

Aims

The analgesic effects of moxibustion on an experimental model of osteoarthritis of the knee were investigated.

Methods

Male Wistar rats (n= 36,296–421g) were used. Intra-articular injection of mono-iodoacetic acid (MIA) was performed to induce knee osteoarthritis. Indirect moxibustion was applied to the lateral aspect of the knee joint every other day for 28 days (14 treatments). Weight bearing of the hind legs was measured directly by the downward pressure applied to footplates, using an Incapacitance Tester. Morphine was injected for testing the validity of weight bearing as a pain measure, and naloxone was used to examine the participation of endogenous opioids in the mechanism of moxibustion analgesia. Data were analysed by calculating the area under the curve.

Results

Injection of MIA significantly reduced weight bearing. No analgesic effects of moxibustion were observed during the initial 7 days (unpaired t test, P=0.83). Continued moxibustion treatments increased weight bearing at the 14th day significantly, and this effect continued until the end of the experiment on the 28th day (P<0.05). A single moxibustion treatment had no immediate effect on weight bearing. The analgesia due to the cumulative effect of moxibustion was antagonised by naloxone injection. Morphine injection in control MIA injected rats increased weight bearing to the normal range, confirming the validity of the measurements.

Conclusion

These results highlight the importance of repeated moxibustion treatments for pain relief in experimental knee osteoarthritis and suggest the existence of sustained inhibitory modulation by endogenous opioids in the moxibustion group.