Improved mesenchymal stem cell survival in ischemic heart through electroacupuncture

Effect and mechanism of acupuncture on endogenous and exogenous stem cells in disease treatment: A therapeutic review

Acupuncture is effective intervention, particularly in nerve, endocrine diseases and immune diseases. The potential mechanisms mediating the effects of acupuncture include anti-inflammatory and oxidative stress, inhibition of cell apoptosis, and stimulation of the proliferation and differentiation of endogenous stem cells. Traditional Chinese medicine combined with stem cell transplantation have a synergistic effect in the treatment of diseases. Increasing studies have found that acupuncture can promote the proliferation, differentiation, homing and survival of exogenous stem cells. This article reviews the mechanism of acupuncture and Chinese herbs on endogenous stem cells and exogenous stem cells in the combined intervention of diverse disorders and the major problems in past 15 years, which will provide a reference for future clinical research.

SDF-1/CXCR4-Mediated Stem Cell Mobilization Involved in Cardioprotective Effects of Electroacupuncture on Mouse with Myocardial Infarction

Stem cell-based therapeutic strategies have obtained a significant breakthrough in the treatment of cardiovascular diseases, particularly in myocardial infarction (MI). Nevertheless, limited retention and poor migration of stem cells are still problems for stem cell therapeutic development. Hence, there is an urgent need to develop new strategies that can mobilize stem cells to infarcted myocardial tissues effectively. Electroacupuncture (EA) intervention can improve cardiac function and alleviate myocardial injury after MI, but its molecular mechanism is still unclear. This study is aimed at observing the effects of EA treatment on the stem cell mobilization and revealing possible mechanisms in the MI model of mice. EA treatment at Neiguan (PC6) and Xinshu (BL15) acupoints was conducted on the second day after the ligation surgery. Then, the number of stem cells in peripheral blood after EA in MI mice and their cardiac function, infarct size, and collagen deposition was observed. We found that the number of CD34-, CD117-, Sca-1-, and CD90-positive cells increased at 6 h and declined at 24 h after EA intervention in the blood of MI mice. The expression of CXC chemokine receptor-4 (CXCR4) protein was upregulated at 6 h after EA treatment, while the ratio of LC3B II/I or p-ERK/ERK showed a reverse trend. In addition, there was obvious difference in EF and FS between wild-type mice and CXCR4+/− mice. The infarct size, collagen deposition, and apoptosis of the injured myocardium in CXCR4+/− mice increased but could be ameliorated by EA. In a word, our study demonstrates that EA alleviates myocardial injury via stem cell mobilization which may be regulated by the SDF-1/CXCR4 axis.

Downregulation of lncRNA Miat contributes to the protective effect of electroacupuncture against myocardial fibrosis

Background

Myocardial fibrosis changes the structure of myocardium, leads to cardiac dysfunction and induces arrhythmia and cardiac ischemia, threatening patients’ lives. Electroacupuncture at PC6 (Neiguan) was previously found to inhibit myocardial fibrosis. Long non-coding RNAs (lncRNAs) play a variety of regulatory functions in myocardial fibrosis, but whether electroacupuncture can inhibit myocardial fibrosis by regulating lncRNA has rarely been reported.

Methods

In this study, we constructed myocardial fibrosis rat models using isoproterenol (ISO) and treated rats with electroacupuncture at PC6 point and non-point as control. Hematoxylin–eosin, Masson and Sirius Red staining were performed to assess the pathological changes and collagen deposition. The expression of fibrosis-related markers in rat myocardial tissue were detected by RT-qPCR and Western blot. Miat, an important long non-coding RNA, was selected to study the regulation of myocardial fibrosis by electroacupuncture at the transcriptional and post-transcriptional levels. In post-transcriptional level, we explored the myocardial fibrosis regulation effect of Miat on the sponge effect of miR-133a-3p. At the transcriptional level, we studied the formation of heterodimer PPARG–RXRA complex and promotion of the TGF-β1 transcription.

Results

Miat was overexpressed by ISO injection in rats. We found that Miat can play a dual regulatory role in myocardial fibrosis. Miat can sponge miR-133a-3p in an Ago2-dependent manner, reduce the binding of miR-133a-3p target to the 3ʹUTR region of CTGF mRNA and improve the protein expression level of CTGF. In addition, it can also directly bind with PPARG protein, inhibit the formation of heterodimer PPARG–RXRA complex and then promote the transcription of TGF-β1. Electroacupuncture at PC6 point, but not at non-points, can reduce the expression of Miat, thus inhibiting the expression of CTGF and TGF-β1 and inhibiting myocardial fibrosis.

Conclusion

We revealed that electroacupuncture at PC6 point can inhibit the process of myocardial fibrosis by reducing the expression of lncRNA Miat, which is a potential therapeutic method for myocardial fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00615-6.

Mesenchymal stem cells: Cell therapy and regeneration potential

Rapid advances in the isolation of multipotent progenitor cells, routinely called mesenchymal stromal/stem cells (MSCs), from various human tissues and organs have provided impetus to the field of cell therapy and regenerative medicine. The most widely studied sources of MSCs include bone marrow, adipose, muscle, peripheral blood, umbilical cord, placenta, fetal tissue, and amniotic fluid. According to the standard definition of MSCs, these clonal cells adhere to plastic, express cluster of differentiation (CD) markers such as CD73, CD90, and CD105 markers, and can differentiate into adipogenic, chondrogenic, and osteogenic lineages in vitro. However, isolated MSCs have been reported to vary in their potency and self-renewal potential. As a result, the MSCs used for clinical applications often lead to variable or even conflicting results. The lack of uniform characterization methods both in vitro and in vivo also contributes to this confusion. Therefore, the name "MSCs" itself has been increasingly questioned lately. As the use of MSCs is expanding rapidly, there is an increasing need to understand the potential sources and specific potencies of MSCs. This review discusses and compares the characteristics of MSCs and suggests that the variations in their distinctive features are dependent on the source and method of isolation as well as epigenetic changes during maintenance and growth. We also discuss the potential opportunities and challenges of MSC research with the hope to stimulate their use for therapeutic and regenerative medicine.

Effects of electroacupuncture combined with stem cell transplantation on anal sphincter injury-induced faecal incontinence in a rat model

BACKGROUND

Bone marrow mesenchymal stem cells (BMSCs) and acupuncture are known to mitigate tissue damage. This study aimed to investigate the therapeutic effects of combined electroacupuncture (EA) stimulation and BMSC injection in a rat model of anal sphincter injury-induced faecal incontinence (FI).

METHODS

60 Sprague-Dawley rats were randomly divided into five groups: sham-operated control, FI, FI+EA, FI+BMSC, and FI+BMSC+EA. The anorectal tissues were collected on days 1, 3, 7 and 14. Repair of the injured anal sphincter was compared using haematoxylin and eosin (HE) and immunocytochemiscal analyses with sarcomeric α actinin. The expression of stromal cell derived factor-1 (SDF-1) and monocyte chemoattractant protein-3 (MCP-3) was detected by quantitative reverse transcription PCR to evaluate the effects of EA on the homing of BMSCs.

RESULTS

The therapeutic effect of combined EA+BMSCs on damaged tissue was the strongest among all the groups as indicated by HE and immunohistochemical staining. The expression of SDF-1 and MCP-3 was significantly increased by combined EA and BMSC treatment when compared with the other groups (P=0.01 to P<0.05), suggesting promotive effects of EA on the homing of BMSCs.

CONCLUSION

The combination of EA and BMSC transplantation effectively repaired the impaired anal sphincters. The underlying mechanism might be associated with apparent promotive effects of EA on the homing of BMSCs. Our study provides a theoretical basis for the development of a non-surgical treatment method for FI secondary to muscle impairment.

Towards the standardization of stem cell therapy studies for ischemic heart diseases: Bridging the gap between animal models and the clinical setting

Today there is an increasing demand for heart transplantations for patients diagnosed with heart failure. Though, shortage of donors as well as the large number of ineligible patients hurdle such treatment option. This, in addition to the considerable number of transplant rejections, has driven the clinical research towards the field of regenerative medicine. Nonetheless, to date, several stem cell therapies tested in animal models fall by the wayside and when they meet the criteria to clinical trials, subjects often exhibit modest improvements. A main issue slowing down the admission of such therapies in the domain of human trials is the lack of protocol standardization between research groups, which hampers comparison between different approaches as well as the lack of thought regarding the clinical translation. In this sense, given the large amount of reports on stem cell therapy studies in animal models reported in the last 3years, we sought to evaluate their advantages and limitations towards the clinical setting and provide some suggestions for the forthcoming investigations. We expect, with this review, to start a new paradigm on regenerative medicine, by evoking the debate on how to plan novel stem cell therapy studies with animal models in order to achieve more consistent scientific production and accelerate the admission of stem cell therapies in the clinical setting.

Electroacupuncture Ameliorates the Coronary Occlusion Related Tachycardia and Hypotension in Acute Rat Myocardial Ischemia Model: Potential Role of Hippocampus

Mechanisms for electroacupuncture (EA) in disease treatments are still enigmatic. Here, we studied whether hippocampus was involved in the protection of EA stimulation on myocardial ischemia injury. Acute myocardial ischemia (AMI) model was produced. EA stimulation at heart meridian from Shenmen (HT7) to Tongli (HT5) was applied to rats 3 times a day for continuous three days. Coronary occlusion related tachycardia and hypotension, indicated by heart rate, mean arterial pressure, and rate pressure product, were apparently impaired after AMI injury. By contrast, EA stimulating could ameliorate the impairments of heart function (P < 0.05). Interestingly, lesion of CA1 region of hippocampus abolished the protection of EA. Neuronal activity in CA1 area was affected by AMI. As evidenced, cell counts, cell types, and frequency of the discharged neurons were facilitated after AMI, while EA stimulation attenuated the abnormalities. Furthermore, c-Fos expression was significantly facilitated in CA1 area after AMI, which was reduced by EA stimulation. Correlations were established between c-Fos expression and cell counts of discharged neurons, as well as between heart function and cell counts of discharged neurons. Taken together, EA stimulation at heart meridian protects against heart dysfunction induced by AMI possibly through suppressing the neuronal activity in CA1 region.

ERK1/2-Egr-1 Signaling Pathway-Mediated Protective Effects of Electroacupuncture in a Mouse Model of Myocardial Ischemia-Reperfusion

Early growth response- (Egr-) 1 is an upstream master switch in controlling inflammatory responses following myocardial ischemia-reperfusion (I/R). Activation of extracellular signal-regulated protein kinase-1 and kinase-2 (ERK1/2) signaling is known to upregulate Egr-1. ERK1/2 pathway has been previously shown to mediate the therapeutic action of electroacupucture (EA). Thus, we hypothesized that EA would reduce myocardial I/R injury and inflammatory responses through inhibiting Egr-1 expression via the ERK1/2 pathway. Mice were pretreated with EA, U0126, or combination of EA and U0126 and then underwent 1 h myocardial ischemia and 3 h reperfusion. We investigated that EA significantly attenuated the I/R-induced upregulation of both Egr-1 and phosporylated-ERK1/2 (p-ERK1/2), decreased myocardial inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and reduced the infarct size and the release of cardiac troponin I (cTnI). U0126 treatment also exhibited the same effect as EA on Egr-1 level and subsequent cardioprotective effects. There was no additive effect of cotreatment with EA and U0126 on the expression of Egr-1 and its downstream target genes (TNF-α, IL-1β) or serum cTnI level. Collectively, these observations suggested that EA attenuates myocardial I/R injury, possibly through inhibiting the ERK1/2-Egr-1 signaling pathway and reducing the release of proinflammatory cytokines.