Electroacupuncture Promotes Nerve Regeneration and Functional Recovery Through Regulating lncRNA GAS5 Targeting miR-21 After Sciatic Nerve Injury

Although the benefits of electroacupuncture (EA) for peripheral nerve injury (PNI) are well accepted in clinical practice, the underlying mechanism remains incompletely elucidated. In our study, we observed that EA intervention led to a reduction in the expression of the long non-coding RNA growth-arrest-specific transcript 5 (GAS5) and an increased in miR-21 levels within the injured nerve, effectively promoting functional recovery and nerve regeneration following sciatic nerve injury (SNI). In contrast, administration of adeno-associated virus expressing GAS5 (AAV-GAS5) weakened the therapeutic effect of EA. On the other hand, both silencing GAS5 and introducing a miR-21 mimic prominently enhanced the proliferation activity and migration ability of Schwann cells (SCs), while also inhibiting SCs apoptosis. On the contrary, inhibition of SCs apoptosis was found to be mediated by miR-21. Additionally, overexpression of GAS5 counteracted the effects of the miR-21 mimic on SCs. Moreover, SCs that transfected with the miR-21 mimic promoted neurite growth in hypoxia/reoxygenation-induced neurons, which might be prevented by overexpressing GAS5. Furthermore, GAS5 was found to be widely distributed in the cytoplasm and was negatively regulated by miR-21. Consequently, the targeting of GAS5 by miR-21 represents a potential mechanism through which EA enhances reinnervation and functional restoration following SNI. Mechanistically, the GAS5/miR-21 axis can modulate the proliferation, migration, and apoptosis of SCs while potentially influencing the neurite growth of neurons.

Electroacupuncture improves cardiac function after myocardial infarction by regulating the mobilization and migration of endogenous stem cells

OBJECTIVE

The aim of this study was to explore the role and mechanisms of electroacupuncture (EA) in the regulation of chemokines in endogenous stem cell mobilization and myocardial regeneration after myocardial infarction (MI).

METHODS

An MI model was constructed in adult male Sprague-Dawley rats by ligating the left anterior descending coronary artery. After 4 weeks of treatment, echocardiography was used to detect changes in cardiac function, and Masson's trichrome staining was used to detect collagen deposition. In addition, immunofluorescence staining was applied to examine von Willebrand factor (vWF)-positive vessels, the expression of cardiac troponin T (cTnT) and proliferation marker Ki67, and the number of c-kit-positive, C-X-C chemokine receptor type 4 (CXCR4)-positive, and Sca-1-positive endogenous stem cells in the infarcted area. In addition, the expression of stromal cell-derived factor (SDF)-1 and stem cell factor (SCF) was detected.

RESULTS

EA increased the ejection fraction after MI, reduced collagen deposition and cellular apoptosis, and increased the number of blood vessels compared with an untreated model group. EA significantly promoted cellular proliferation, except for myocardial cells, and significantly increased the number of c-kit-, CXCR4- and Sca-1-positive stem cells. Moreover, the expression of SDF-1 and SCF in myocardial tissue in the EA group was significantly higher than that in the (untreated) MI group.

CONCLUSIONS

EA appears to promote angiogenesis and reduce collagen deposition, thus improving the cardiac function of rats with MI. The underlying mechanism of action may involve endogenous stem cell mobilization mediated by SDF-1/CXCR4 and SCF/c-kit.

Notoginsenoside R1-loaded mesoporous silica nanoparticles targeting the site of injury through inflammatory cells improves heart repair after myocardial infarction

Notoginsenoside R1 (NGR1) is the main monomeric component extracted from the dried roots and rhizomes of Panax notoginseng, and exerts pharmacological action against myocardial infarction (MI). Owing to the differences in compound distribution, absorption, and metabolism in vivo, exploring a more effective drug delivery system with a high therapeutic targeting effect is crucial. In the early stages of MI, CD11b-expressing monocytes and neutrophils accumulate at infarct sites. Thus, we designed a mesoporous silica nanoparticle-conjugated CD11b antibody with loaded NGR1 (MSN-NGR1-CD11b antibody), which allowed NGR1 precise targeted delivery to the heart in a noninvasively manner. By increasing targeting to the injured myocardium, intravenous injection of MSN-NGR1-CD11b antibody nanoparticle in MI mice improved cardiac function and angiogenesis, reduced cell apoptosis, and regulate macrophage phenotype and inflammatory factors and chemokines. In order to further explore the mechanism of NGR1 protecting myocardium, cell oxidative stress model and oxygen-glucose deprivation (OGD) model were established. NGR1 protected H9C2 cells and primary cardiomyocytes against oxidative injury induced by H₂O₂ and OGD treatment. Further network pharmacology and molecular docking analyses suggested that the AKT, MAPK and Hippo signaling pathways were involved in the regulation of NGR1 in myocardial protection. Indeed, NGR1 could elevate the levels of p-Akt and p-ERK, and promote the nuclear translocation of YAP. Furthermore, LY294002 (AKT inhibitor), U0126 (ERK1/2 inhibitor) and Verteporfin (YAP inhibitor) administration in H9C2 cells indicated the involvement of AKT, MAPK and Hippo signaling pathways in NGR1 effects. Meanwhile, MSN-NGR1-CD11b antibody nanoparticles enhanced the activation of AKT and MAPK signaling pathways and the nuclear translocation of YAP at the infarcted site. Our research demonstrated that MSN-NGR1-CD11b antibody nanoparticle injection after MI enhanced the targeting of NGR1 to the infarcted myocardium and improved cardiac function. More importantly, our pioneering research provides a new strategy for targeting drug delivery systems to the ischemic niche.

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CD11b antibody modification enhanced the target of Mesoporous silica nanoparticles to injured myocardium.

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NGR1 promoted the survival of H9C2 against oxidative stress injury through PIK3/AKT, MAPK/ERK and YAP signaling pathways.

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NGR1 protected neonatal and adult cardiomyocytes from H₂O₂ and OGD induced oxidative stress damage.

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MSN-NGR1-CD11b antibody nanoparticles improved heart function by activating PIK3/AKT, MAPK/ERK and YAP signaling pathways.

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MSN-NGR1-CD11b antibody nanoparticles induced M2 polarization of macrophages and regulated the inflammatory factors.

Electroacupuncture Promoted Nerve Repair After Peripheral Nerve Injury by Regulating miR-1b and Its Target Brain-Derived Neurotrophic Factor

Growing evidence indicates that electroacupuncture (EA) has a definite effect on the treatment of peripheral nerve injury (PNI), but its mechanism is not completely clear. MicroRNAs (miRNAs) are involved in the regulation of a variety of biological processes, and EA may enhance PNI repair by regulating miRNAs. In this study, the rat sciatic nerve injury model was treated with EA for 4 weeks. Acupoints Huantiao (GB30) and Zusanli (ST36) were stimulated by EA 20 min once a day, 6 days a week for 4 weeks. We found that EA treatment downregulated the expression of miR-1b in the local injured nerve. In vitro experiments showed that overexpression of miR-1b inhibited the expression of brain-derived neurotrophic factor (BDNF) in rat Schwann cell (SC) line, while BDNF knockdown inhibited the proliferation, migration, and promoted apoptosis of SCs. Subsequently, the rat model of sciatic nerve injury was treated by EA treatment and injection of agomir-1b or antagomir-1b. The nerve conduction velocity ratio (NCV), sciatic functional index (SFI), and S100 immunofluorescence staining were examined and showed that compared with the model group, NCV, SFI, proliferation of SC, and expression of BDNF in the injured nerves of rats treated with EA or EA + anti-miR-1b were elevated, while EA + miR-1b was reduced, indicating that EA promoted sciatic nerve function recovery and SC proliferation through downregulating miR-1b. To summarize, EA may promote the proliferation, migration of SC, and nerve repair after PNI by regulating miR-1b, which targets BDNF.

[Effect of electroacupuncture on recognition memory and levels of Aβ, inflammatory factor proteins and aquaporin 4 in hippocampus of APP/PS1 double transgenic mice]

OBJECTIVE

To investigate the effect of electroacupuncture (EA) at "Baihui "(GV20) and "Shenshu "(BL23) on activation of glial cells, expression of inflammatory factor proteins and aquaporin 4 (AQP4)in the hippocampus of amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice, so as to explore its mechanisms underlying improvement of Alzheimer's disease(AD).

METHODS

Twenty C57/BL6 background male APP695/PS1-dE9(APP/PS1) double transgenic mice (model group) and 20 wild type (WT) C57/BL6 mice (blank group) were respectively randomized into control and EA groups. EA (2 Hz/15 Hz, 1－2 mA) was applied to GV20 and bilateral BL23 for 30 min, once daily, 6 days a week for 4 weeks. The recognition memory ability was detected by novel object recognition tests in a behavior test box. The percentage of time spent in close interaction with novel object (C) relative to the total time was used to generate preference index. The contents of hippocampal β amyloid protein (Aβ)_1-40 and Aβ_1-42 were assayed using ELISA, and the expression levels of glial fibrillary acidic protein (GFAP), ionic calcium binding receptor molecule-1 (Iba-1), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) proteins in the hippocampus measured by Western blot. The activities of hippocampal astrocytes (GFAP-labelled cells), microglia (Iba-1-labelled cells) and the polarity expression of AQP4 (for removing Aβ) were measured by immunohistochemistry.

RESULTS

The preference index was significantly decreased in the model group relatively to the blank control group (P<0.05) and considerably increased in the model＋EA group relatively to the model group (P<0.05), suggesting an improvement of the recognition memory after EA. The contents of Aβ_1-40 and Aβ_1-42, immunoactivity of GFAP and Iba-1, expression levels of GFAP, Iba-1, IL-1β, IL-6 and TNF-α proteins were significantly higher in the model group than in the blank control group (P<0.01，P<0.05), while the AQP4 immunoactivity was notably lower in the model group than in the blank control group (P<0.05). Compared with the model group, the levels of Aβ_1-40 and Aβ_1-42, GFAP, Iba-1, IL-1β, IL-6 and TNF-α proteins, and the percentage of Aβ plaque area were significantly decreased in the model＋EA group (P<0.01，P<0.05), and the immunoactivity of AQP4 was significantly increased in the mo-del＋EA group (P<0.05). No significant changes were found in the above-mentioned indexes in the blank＋EA group relevant to the blank control group (P>0.05)．.

CONCLUSION

EA at GV20 and BL23 can reduce inflammatory reaction and Aβ level, suppress activation of astrocytes and microglia, and up-regulate expression of AQP4 in the hippocampus tissue in APP/PS1 transgenic mice, which may contribute to its effect in improving recognition memory ability, suggesting a role of EA intervention in delaying the development of AD via promoting the drainage of Aβ by the glymphatic system in the brain.

Schwann cells apoptosis is induced by high glucose in diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus that affects approximately half of patients with diabetes. Current treatment regimens cannot treat DPN effectively. Schwann cells (SCs) are very sensitive to glucose concentration and insulin, and closely associated with the occurrence and development of type 1 diabetic mellitus (T1DM) and DPN. Apoptosis of SCs is induced by hyperglycemia and is involved in the pathogenesis of DPN. This review considers the pathological processes of SCs apoptosis under high glucose, which include the following: oxidative stress, inflammatory reactions, endoplasmic reticulum stress, autophagy, nitrification and signaling pathways (PI3K/AKT, ERK, PERK/Nrf2, and Wnt/β-catenin). The clarification of mechanisms underlying SCs apoptosis induced by high glucose will help us to understand and identify more effective strategies for the treatment of T1DM DPN.

miR-1b overexpression suppressed proliferation and migration of RSC96 and increased cell apoptosis

Peripheral nerve injury (PNI) is a global problem that leads to severe disability and high healthcare expenditure. Accumulating evidence suggested that the phenotypes of Schwann cells (SCs) could be regulated by microRNAs (miRNAs) and expressions of various miRNAs are altered after PNI. In this study, the expression of miR-1b in the injured nerve and hypoxia-treated SCs was detected through qRT-PCR. The target genes of miR-1b were predicted by bioinformatics prediction and dual-luciferase reporter assay and verified through qRT-PCR and western blot. The effects of miR-1b and its specific target gene on the proliferation, migration and apoptosis of SCs were determined and the regulation of miR-1b on peripheral nerve regeneration after PNI was further investigated in vivo. We found that miR-1b was obviously downregulated in the injured nerve in a rat sciatic nerve transection model and directly targeted N-myc downstream-regulated gene 3 (NDRG3) by binding to its 3'-UTR and caused both mRNA degradation and translation suppression of NDRG3. Overexpression of miR-1b or knockdown of NDRG3 decreased the proliferation and migration as well as increased the apoptosis of SCs. NDRG3 reversed the effects of miR-1b overexpression on proliferation/migration/apoptosis of RSC96. In addition, injection of miR-1b antagomir promoted the expression of NDRG3 in the injured nerve following sciatic nerve injury. Compared to the model group, the rats treated with miR-1b agomir had lower functional recovery rate, and downregulation of miR-1b through injection of specific antagomir improved the functional recovery rate according to the results of sciatic functional index and nerve conduction velocity. Overall, our results will contribute to the development of novel targets for promoting nerve regeneration after PNI.

Electroacupuncture and moxibustion promote regeneration of injured sciatic nerve through Schwann cell proliferation and nerve growth factor secretion

Using electroacupuncture and moxibustion to treat peripheral nerve injury is highly efficient with low side effects. However, the electroacupuncture- and moxibustion-based mechanisms underlying nerve repair are still unclear. Here, in vivo and in vitro experiments uncovered one mechanism through which electroacupuncture and moxibustion affect regeneration after peripheral nerve injury. We first established rat models of sciatic nerve injury using neurotomy. Rats were treated with electroacupuncture or moxibustion at acupoints Huantiao (GB30) and Zusanli (ST36). Each treatment lasted 15 minutes, and treatments were given six times a week for 4 consecutive weeks. Behavioral testing was used to determine the sciatic functional index. We used electrophysiological detection to measure sciatic nerve conduction velocity and performed hematoxylin-eosin staining to determine any changes in the gastrocnemius muscle. We used immunohistochemistry to observe changes in the expression of S100—a specific marker for Schwann cells—and an enzyme-linked immunosorbent assay to detect serum level of nerve growth factor. Results showed that compared with the model-only group, sciatic functional index, recovery rate of conduction velocity, diameter recovery of the gastrocnemius muscle fibers, number of S100-immunoreactive cells, and level of nerve growth factor were greater in the electroacupuncture and moxibustion groups. The efficacy did not differ between treatment groups. The serum from treated rats was collected and used to stimulate Schwann cells cultured in vitro. Results showed that the viability of Schwann cells was much higher in the treatment groups than in the model group at 3 and 5 days after treatment. These findings indicate that electroacupuncture and moxibustion promoted nerve regeneration and functional recovery; its mechanism might be associated with the enhancement of Schwann cell proliferation and upregulation of nerve growth factor.

Designer Self-Assemble Peptides Maximize the Therapeutic Benefits of Neural Stem Cell Transplantation for Alzheimer's Disease via Enhancing Neuron Differentiation and Paracrine Action

The neuropathological hallmarks of Alzheimer's disease (AD) include the presence of extracellular amyloid-β peptide (Aβ) in the form of amyloid plaques and neuronal loss. Neural stem cell (NSC) is being scrutinized as a promising cell replacement therapy for various neurodegenerative diseases. However, the unfavorable niche at the site of degenerative disease is hostile to the survival and differentiation of transplanted cells. Here, we undertook in vitro and in vivo works to examine whether a designer self-assemble peptide (DSP), which contains one functional domain Tyr-Ile-Gly-Ser-Arg (YIGSR) derived from laminin, promotes the survival and neuronal differentiation of NSC and behavioral improvement. We found that DSP could undergo spontaneous assembly into well-ordered nanofibers, and it not only facilitated the cell viability in normal culture condition, but also decreased the number of apoptotic cells induced by Aβ in vitro. NSC seeded in DSP showed much more neuronal differentiation than that seeded in self-assemble peptide (SP) or alone. In the AD model, NSC transplantation in DSP-treated AD rats demonstrated much more obvious cognitive rescue with restoration of learning/memory function compared with NSC transplantation in SP, NSC alone, or DSP alone treated ones. Interestingly, DSP enhanced the survival and neuronal differentiation of transplanted NSC. Apoptosis levels in the CA1 region and Aβ level in the hippocampus were significantly decreased in the group of NSC transplantation in DSP. Moreover, synaptic function, indicated by the expression of pre-synaptic protein synapsin-1, was restored and the secretion of anti-inflammatory and neurotrophic factors were increased, such as IL-10, brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and insulin-like growth factor 1 (IGF-1), while the expression of pro-inflammatory factors were decreased, such as TNF-α and IL-1β. These data firstly unveiled that the biomaterial DSP can maximize the therapeutic benefits of NSC transplantation for AD through improving the survival and differentiation of transplanted stem cells and promoting the effects of neuroprotection, anti-neuroinflammatory and paracrine action. Our results may have important clinical implications for the design of future NSC-based strategies using the biomaterials for various neurodegenerative diseases including AD.

Electroacupuncture improves memory and protects neurons by regulation of the autophagy pathway in a rat model of Alzheimer's disease

BACKGROUND

Acupuncture is a potential therapy for Alzheimer's disease (AD), but its clinical effects and underlying mechanisms are not fully understood. Emerging evidence suggests autophagy is involved in β-amyloid (Aβ) clearance. We hypothesised that electroacupuncture (EA) treatment of AD involves the autophagy pathway in rats.

METHODS

We injected 2μl Aβ_1-40 bilaterally into the hippocampi of 42 rats to establish AD. Rats remained untreated (AD group, n=14) or received 24 EA treatments at GV20+BL23 over 28 days from day 7 post-injection with/without co-treatment with 3-methyladenine (3-MA), an autophagy inhibitor (AD+EA+3-MA and AD+EA groups, respectively, n=14 each). Cognitive function was evaluated by Morris water maze (MWM) testing. Hippocampi were examined by transmission electron microscopy (TEM) and stained with haematoxylin and eosin/transferase dUTP nick end labelling (TUNEL) to assess neuronal morphology/apoptosis, respectively. Protein expression of Beclin-1, LC3 and Aβ_1-40 was examined.

RESULTS

In the MWM test, the AD+EA group showed an improvement in parameters consistent with improved learning/memory compared to untreated AD rats, and 3-MA attenuated these effects. EA mitigated cellular apoptosis resulting from Aβ infusion in the CA1 region and enhanced LC3II/LC3I ratios and Beclin-1 expression. Numerous autophagosome precursors and enlarged autophagosomes were observed by TEM in the hippocampi of EA-treated rats. Reduced Aβ levels, and co-localisation of Aβ and LC3II, were observed following EA treatment by immunofluorescence staining. EA+3-MA treated rats had much higher TUNEL-positive neurons, lower LC3II/LC3I ratios and Beclin-1 expression, and elevated Aβ levels compared with EA alone.

CONCLUSIONS

EA reduces neuronal apoptosis, enhances degradation of Aβ, and improves learning/memory in AD rats by upregulating the autophagy pathway.

[Study on force feedback of acupuncture at Fengchi (GB 20)]

Acupuncture manipulations on Fengchi (GB 20) of famous doctors were taken through force feedback device, then the data was input into a digitized virtual human. Virtual Fengchi (GB 20) acupuncture force feedback simulation system was built through the virtual reality technology to achieve one-to-one high simulative manipulation effect for acupuncture students. The interaction force of the needle body and human tissues was analyzed during the acupuncture process on the 3D digital human integrated with information of Fengchi (GB 20) according to the physical characteristics of the tissues under this point. The mechanical model which is used to imitate the stress received by the body of the needle was established, and transmitted truly to the operator by the force feedback device. Thus, Fengchi (GB 20) virtual acupuncture force feedback simulation was preliminary established, and the sense of touch could be reproduced lively on the visualized virtual acupuncture human. It is held that Fengchi (GB 20) acupuncture force feedback research is a preliminary exploration for virtual acupuncture that integrated with the information of visual, tactile and force feedback. And it also provided a dynamic one-to-one simulation approach for acupuncture teaching.

[Progress of researches on mechanisms of acupuncture intervention of Alzheimer's disease]

Alzheimer's disease (AD) is one of the major diseases threatening the aged people's health. In the present paper, the authors reviewed development of studies on acupuncture treatment of AD from: 1) regulating release of neurotransmitters (cholinergic, amino-acids and monoamine neurotransmitters), 2) protecting cerebral neurons from apoptosis (anti-oxidative stress, improving synaptic plasticity, and suppressing apoptosis), 3) improving levels of neurotrophic factors, 4) regulating hippocampal intracellular signaling, 5) inhibiting inflammatory reactions of the brain tissue, 6) adjusting the level of abnormal proteins (microtubule-associated protein, beta-amyloid), and 7) up-regulating the level of autophagy activity. However, current experimental studies can not completely answer clinical questions due to limited model designs and complicated pathological mechanisms of AD. Many findings of biological indexes need being verified further. Reasonable therapeutic regimens of acupuncture formulated according to syndrome differentiation will help improving clinical curative effect and the corresponding research on new therapeutic targets may be helpful to our understanding about the mechanism of acupuncture.

[Study on the angle and depth of needle insertion at Huantiao (GB 30) by three-dimensional reconstruction]

OBJECTIVE

To observe the anatomic structure of Huantiao (GB 30) visually, to imitate the inserting process of the needle to explore the safty of needle insertion and improve the therapeutic effect of acupuncture in clinic.

METHODS

Combined with anatomic structure of acupoint, muscles and other tissues related with Huantiao (GB 30) were interactively segmented in VOXEL-MAN with the computer graphics technology. Nerves and blood vessels were reconstructed by establishing mathematic model, and the needle-inserting animation of Huantiso (GB 30) was obtained by running script file.

RESULTS

The three-dimensional (3-D) visualization of Huantiao (GB 30) on needle-inserting animation was accomplished, the spatial location and expression of Huantiao (GB 30) in the digitized virtual human body were observed, the virtual inserting process was imitated realistically, and the 3-D animation of needle insertion at Huantiao (GB 30) was created.

CONCLUSION

Building mathematic model is favorable for expressing the anatomic structure of Huantiao (GB 30) in 3-D space, imitating the process of needle insertion realistically and observing the spatial structure of the point and the around tissues, which can provide a solid foundation for the safety of needle insertion of acupoints and improve therapeutic effect of acupuncture in clinic.

[Comparative experimental study on treatment of rat's injured sciatic nerve with electroacupuncture and Buyang Huanwu Decoction]

OBJECTIVE

To study the effect of the electroacupuncture and Buyang Huanwu Decoction (BYHWD) on the regeneration of the rat's injured sciatic nerve.

METHODS

Rat's sciatic nerve injury model was made by operation. The rats were treated with electroacupuncture or BYHWD and their nerve electro-physiological indices and histological changes tested by HRP were observed.

RESULTS

It was demonstrated that the recovery ratios of nerve conduction velocity and muscle evoked action potential of the group treated with electroacupuncture and the group treated with BYHWD were higher than those of the group treated with western medicine or the group without treatment. The differences were significant. The labeling cells in anterior horn of spinal marrow and spinal ganglion of the group treated with electroacupuncture and the group treated with BYHWD were more abundant than those of the group treated with western medicine or the group without treatment. The differences were significant. The effect of electroacupuncture was better than that of the BYHWD.

CONCLUSION

It suggests that both electroacupuncture therapy and BYHWD can promote the recovery of the function in early stage of injured nerve, and they are effective methods for promoting the regeneration of injured peripheral nerve.

[Study on the visualization of the Lung Meridian of Hand-Taiyin]

OBJECTIVE

To display the Lung Meridian of Hand-Taiyin at the body surface in a virtual human.

METHODS

After defining the acupoints as the control points, chose suitable function interpolation to compose skeleton curve, actualize surface rendering and to rebuild a tube-like meridian model.

RESULTS

The rebuilt tubular meridian model had a good visual effect, and clearly showed different anatomic structures of the Lung Meridian of Hand-Taiyin.

CONCLUSION

We primarily and successfully accomplish the visualization display of the Lung Meridian of Hand-Taiyin in a virtual human, which affords a data carrier for building a meridian research platform.