Hypothalamus-related resting brain network underlying short-term acupuncture treatment in primary hypertension

Acupuncture with twirling reinforcing and reducing manipulation shows a control of hypertension and regulation of blood pressure-related target brain regions in spontaneously hypertensive rat: a preliminary resting-state functional MRI study

Aim

To observe the effects of acupuncture manipulations on blood pressure and brain function in spontaneously hypertensive rats and elucidate the anti-hypertensive effect of the manipulations' central mechanism.

Methods

This study used acupuncture twirling reinforcing, acupuncture twirling reducing, and acupuncture twirling uniform reinforcing-reducing manipulations to act on the bilateral TaiChong point of rats. The depth of acupuncture was 1.5-2 mm, and twisting was performed at a frequency of 60 times/min within ±360° for 3 min, followed by the needle being retained for 17 min. Functional magnetic resonance imaging was performed at the end of the intervention. Regional homogeneity and amplitude of low-frequency fluctuations were used to assess the differences in brain regions in each group of rats, and the core brain region (left hypothalamus) among the differential brain regions was selected as the seed for functional connectivity analysis.

Results

(1) The anti-hypertensive effect was achieved by acupuncture manipulations, and the anti-hypertensive effect of twirling reducing manipulation on spontaneously hypertensive rats was better than that of twirling uniform reinforcing-reducing and twirling reinforcing manipulations. (2) After regional homogeneity and amplitude of low-frequency fluctuations analyses, the hypothalamus, the brain region related to blood pressure, was activated in the twirling uniform reinforcing-reducing manipulation group; the corpus callosum and cerebellum were activated in the twirling reinforcing manipulation group; and the hypothalamus, olfactory bulb, corpus callosum, brainstem, globus pallidum, and striatum were activated in the twirling reducing manipulation group. (3) According to the functional connectivity analysis, different acupuncture manipulations increased the functional connections between seed points and the brainstem, olfactory bulb, and cerebellum, etc.

Conclusion

These results suggest that acupuncture manipulations achieved the hypotensive effect and the twirling reducing manipulation had a better hypotensive effect on spontaneously hypertensive rats than twirling uniform reinforcing-reducing and twirling reinforcing manipulations; the central mechanism of the anti-hypertensive effect of twirling reinforcing and reducing manipulation may be related to the activation of brain regions associated with blood pressure regulation and the functional connections between them. Furthermore, brain regions involved in motor control, cognition, and hearing were also activated. We hypothesize that activation of these brain regions may help prevent or mitigate the onset and progression of hypertensive brain damage.

Electroacupuncture and manual acupuncture at LR3 and ST36 have attenuating effects on hypertension and subsequent cognitive dysfunction in spontaneously hypertensive rats: A preliminary resting-state functional magnetic resonance imaging study

Introduction

Chronic hypertension may have a contributory role toward cognitive impairment. Acupuncture exerts protective effects on cognitive functions while controlling the blood pressure. However, the neural mechanism underlying the dual attenuating effect of acupuncture remains unclear. In this study, we investigated the effects of electroacupuncture (EA) and manual acupuncture (MA) on the functional activity of the brain regions of spontaneously hypertensive rats (SHRs) by through resting-state functional magnetic resonance imaging (rs-fMRI). We also evaluated the differences in these functional activities between the EA and MA groups.

Methods

We randomly assigned 30 SHRs into the EA, MA, and model (SHR) groups. Wistar Kyoto rats (n = 10) were used as normal control (WKY). The interventions were administered once every alternate day for 12 weeks. The systolic blood pressure of all rats was recorded every 2 weeks until the end of the intervention. After the intervention, rs-fMRI scanning was performed to access the whole brain data of rats randomly selected from each group evenly. The amplitude of low frequency fluctuation (ALFF) analysis, regional homogeneity (ReHo) analysis, and functional connectivity (FC) analysis were also conducted. The Morris water maze (MWM) test was conducted to evaluate the learning and memory of the rats. Hematoxylin-eosin staining and Nissl staining were performed to observe histopathological changes in the key brain regions.

Results

We demonstrated that, when compared with the SHR group, the EA and MA groups had significantly lower blood pressure and better performance for behavioral test indices, and that the effect of EA was better than that of MA. ALFF and ReHo analyses revealed enhancement of the neuronal activity of some functionally impaired brain areas in the EA and MA groups. The main callback brain regions included the hypothalamus, entorhinal cortex, brain stem, prelimbic cortex, cingulate cortex, corpus callosum, and cerebellum. The FC analysis demonstrated that EA and MA enhanced the functional connectivity between the seeds and brain regions such as the brain stem, entorhinal cortex, hippocampus, prelimbic cortex, and cerebellum. The pathological test of the entorhinal cortex also verified the protective effect of acupuncture on the neuronal functional activity.

Discussion

Our findings suggested that EA and MA exhibited attenuating effects on hypertension and cognitive dysfunction by enhancing the functional activities in the corresponding brain regions. Moreover, EA activated more callback brain regions and functional connectivity than MA, which may explain why the effect of EA was better than that of MA.

Resting-State fMRI in Studies of Acupuncture

Research exploring the mechanism of acupuncture has been a hot topic in medicine. Resting-state functional magnetic resonance imaging (rs-fMRI) research is a noninvasive and extensive method, which is aimed at the research of the mechanism of acupuncture. Researchers use fMRI technologies to inspect the acupuncture process. The authors reviewed the application of rs-fMRI in acupuncture research in recent 10 years from the aspects of studying acupoints, subjects, acupuncture methods, and intensities. The results found that the application of rs-fMRI in acupuncture research mainly includes research on the onset mechanism of acupuncture treatment; visual evidence of diagnosis and treatment of dominant diseases; efficacy assessments; physiological mechanism of acupoint stimulation; and specific visualization of acupoints.

Peripheral ERK modulates acupuncture-induced brain neural activity and its functional connectivity

Acupuncture has been widely used as a therapeutic intervention, and the brain network plays a crucial role in its neural mechanism. This study aimed to investigate the acupuncture mechanism from peripheral to central by identifying how the peripheral molecular signals induced by acupuncture affect the brain neural responses and its functional connectivity. We confirmed that peripheral ERK activation by acupuncture plays a role in initiating acupuncture-induced peripheral proteomic changes in mice. The brain neural activities in the neocortex, hippocampus, thalamus, hypothalamus, periaqueductal grey, and nucleus of the solitary tract (Sol) were significantly changed after acupuncture, and these were altered by peripheral MEK/MAPK inhibition. The arcuate nucleus and lateral hypothalamus were the most affected by acupuncture and peripheral MEK/MAPK inhibition. The hypothalamic area was the most contributing brain region in contrast task PLS analysis. Acupuncture provoked extensive changes in brain functional connectivity, and the posterior hypothalamus showed the highest betweenness centrality after acupuncture. After brain hub identification, the Sol and cingulate cortex were selected as hub regions that reflect both degree and betweenness centrality after acupuncture. These results suggest that acupuncture activates brain functional connectivity and that peripheral ERK induced by acupuncture plays a role in initiating brain neural activation and its functional connectivity.

Proteomics analysis of the hypothalamus in spontaneously hypertensive rats treated with twirling reinforcing manipulation, twirling reducing manipulation or electroacupuncture

Hypertension is one of the primary risk factors for cardiovascular diseases. Numerous proteins serve a critical role in hypertension. Acupuncture has been widely used as a treatment for hypertension in China. The results of the current study suggested that electroacupuncture (EA), twirling reinforcing manipulation (TRFM) and twirling reducing manipulation (TRDM) may be useful in the treatment of hypertension. Additionally, proteome analysis of spontaneously hypertensive rats treated with EA, TRFM and TRDM was performed. There were 117 (EA group), 61 (TRFM group) and 86 (TRDM group) differentially expressed proteins (DEPs) identified in the respective experimental groups compared with the model group. Moreover, parallel reaction monitoring assays were used to validate the reliability of the DEPs. The majority of the results were consistent with previous proteomics results, in particular that for expression of neudesin neurotrophic factor (NENF). NENF may potentially represent an antihypertensive drug target.

Can Acupuncture Treatment of Hypertension Improve Brain Health? A Mini Review

With age, cerebrovascular and neurodegenerative diseases (e.g., dementia and Alzheimer’s) are some of the leading causes of death in the United States. Related to these outcomes is the increased prevalence of hypertension, which independently increases the development of cerebrovascular and neurodegenerative diseases. While a direct mechanistic link between hypertension and poor brain health is unknown, many hypothesize that the etiology stems from poor blood pressure (BP) and cerebrovascular regulation. This dysfunction fosters hypoperfusion of the brain, causing stress to the tissue through a nutrient mismatch, subtly damaging the brain over many years. Current Western medical treatment relies on pharmacological treatment (mainly beta-blockers, angiotensin-converting enzyme inhibitors, or a combination of the two). However, Western treatments have not been successful in mitigating brain health outcomes and are burdened with unwanted side effects and non-adherence issues. Alternatively, traditional East Asia medicine has used acupuncture as a treatment for hypertension and may offer a promising approach in response to the limitations of conventional therapy. While detailed clinical and mechanistic experimental evidence is lacking, acupuncture has been observed to reduce BP and improve endothelial function in hypertensive adults. Further, acupuncture has been shown to have specific cerebrovascular effects, increasing cerebrovascular reactivity in healthy adults, highlighting possible neuroprotective properties. Therefore, our review is aimed at evaluating acupuncture as a treatment for hypertension and the potential impact on brain health. We will interrogate the current literature as well as discuss the proposed neural and vascular mechanisms by which acupuncture acts.

The Mechanism of Acupuncture in Treating Essential Hypertension: A Narrative Review

Essential hypertension has a high incidence worldwide, and patients with essential hypertension endure a lifetime of medication, leading to a heavy economic burden on the patient's family and causing serious impacts on the patient's quality of life. Much evidence has demonstrated that acupuncture as an adjunctive therapy can lower blood pressure in patients with hypertension, but the mechanism of its action is unclear. This article reviews the research from 2000 to 2018 regarding the mechanism of acupuncture for hypertension, and we summarize the current knowledge about using acupuncture for hypertension. We found that the mechanism whereby acupuncture lowers blood pressure is related to the regulation of renin-angiotensin-aldosterone system, vascular endothelium, oxidative stress, neuroendocrine system, and so on. Besides, there may be cross-talk between multiple systems and multiple targets. We also investigate the influence factors of acupuncture for hypertension. These results may provide evidence and research ideas for the treatment of hypertension via acupuncture.

Efficacy of acupuncture for lifestyle risk factors for stroke: A systematic review

BACKGROUND

Modifications to lifestyle risk factors for stroke may help prevent stroke events. This systematic review aimed to identify and summarise the evidence of acupuncture interventions for those people with lifestyle risk factors for stroke, including alcohol-dependence, smoking-dependence, hypertension, and obesity.

METHODS

MEDLINE, CINAHL/EBSCO, SCOPUS, and Cochrane Database were searched from January 1996 to December 2016. Only randomised controlled trials (RCTs) with empirical research findings were included. PRISMA guidelines were followed and risk of bias was assessed via the Cochrane Collaboration risk of bias assessment tool. The systematic review reported in this paper has been registered on the PROSPERO (#CRD42017060490).

RESULTS

A total of 59 RCTs (5,650 participants) examining the use of acupuncture in treating lifestyle risk factors for stroke met the inclusion criteria. The seven RCTs focusing on alcohol-dependence showed substantial heterogeneity regarding intervention details. No evidence from meta-analysis has been found regarding post-intervention or long-term effect on blood pressure control for acupuncture compared to sham intervention. Relative to sham acupuncture, individuals receiving auricular acupressure for smoking-dependence reported lower numbers of consumed cigarettes per day (two RCTs, mean difference (MD) = -2.75 cigarettes/day; 95% confidence interval (CI) = -5.33, -0.17; p = 0.04). Compared to sham acupuncture those receiving acupuncture for obesity reported lower waist circumference (five RCTs, MD = -2.79 cm; 95% CI: -4.13, -1.46; p<0.001). Overall, only few trials were considered of low risk of bias for smoking-dependence and obesity, and as such none of the significant effects in favour of acupuncture interventions were robust against potential selection, performance, and detection bias.

CONCLUSIONS

This review found no convincing evidence for effects of acupuncture interventions for improving lifestyle risk factors for stroke.

Effect of Acupuncture at LR3 on Cerebral Glucose Metabolism in a Rat Model of Hypertension: A 18F-FDG-PET Study

Our objective was to investigate the effect of acupuncture at LR3 on cerebral glucose metabolism in spontaneously hypertensive rats (SHRs). We used ¹⁸F-2-fluoro-deoxy-D-glucose positron emission tomography (¹⁸F-FDG-PET) to examine the effects of acupuncture at LR3 on cerebral glucose metabolism in SHRs. SHRs were randomly allocated to receive no treatment (SHR group), needling at LR3 (SHR + LR3 group), or sham needling (SHR + sham group). Rats received 10 min acupuncture once per day for 7 days and were compared to normotensive Wistar Kyoto (WKY) rats. Blood pressure (BP) measurement and PET were performed after the first needling and the 7-day treatment period. BP was lower in the SHR + LR3 group compared to the other SHR groups between 30 and 60 min after the first needling and at 24 and 48 h after the 7-day treatment period. Glucose metabolism in the motor, sensory, and visual cortices was decreased in SHR group compared to WKY group. Needling at LR3 was associated with decreased glucose metabolism in the dorsal thalamus, thalamus, and hypothalamus and with increased metabolism in the cerebellar anterior and posterior lobes, medulla oblongata, and sensory cortex compared to the SHR group. These findings suggest that LR3 acupuncture improves hypertension through a mechanism involving altered brain activation in SHRs.

Cerebral Targeting of Acupuncture at Combined Acupoints in Treating Essential Hypertension: An Rs-fMRI Study and Curative Effect Evidence

The study attempted to explore that the synergistic effect of acupoints combination is not a simple superposition of single acupoint's effect by comparing and analyzing the changes of blood pressure (BP), SF-36, and brain regions after acupuncture treatment. 47 patients were randomly divided into LR3+KI3 group, LR3 group, and KI3 group. Subjects received Rs-fMRI scan, BP measurement, and SF-36 questionnaires before and after treatment and short-term acupuncture treatment. After treatment, there were no significant differences in BP and SF-36 among 3 groups, compared to the case before treatment, SBP of 3 groups decreased, and DBP significantly decreased while vitality and mental health significantly increased in LR3+KI3 group. Both number and scopes of changes of brain regions in LR3+KI3 group were the largest, which mainly included BAs 3, 4, 8, 19, 21, 24, 32, 44, and 45. In conclusion, acupuncture at LR3+KI3 may auxiliarily reduce BP and improve the vitality and mental health of patients, and the changes of brain regions were related to somatesthesia, movement, vision, audition, emotion and mood, language, memory, etc. BAs 4, 9, 10, 24, 31, 32, and 46 may be the targeting brain areas of acupuncture in assisting hypotension. It is suggested that acupoints combination of LR3+KI3 maybe generates a synergistic effect, and it is not simple sum of single acupoint effect.

IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS

Objective:

This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint.

Methods:

A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method.

Results:

The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint.

Conclusion:

Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.

Acupuncture Decreases Blood Pressure Related to Hypothalamus Functional Connectivity with Frontal Lobe, Cerebellum, and Insula: A Study of Instantaneous and Short-Term Acupuncture Treatment in Essential Hypertension

The therapeutic effects of acupuncture in decreasing blood pressure are ambiguous and underlying acupuncture in hypertension treatment has not been investigated. Our objective was to observe the change of quality of life and compare the differences in brain functional connectivity by investigating instantaneous and short-term acupuncture treatment in essential hypertension patients. A total of 30 patients were randomly divided into the LR3 group and sham acupoint group. Subjects received resting-state fMRI among preacupuncture, postinstantaneous, and short-term acupuncture treatment in two groups. Hypothalamus was selected as the seed point to analyze the changes in connectivity. We found three kinds of results: (1) There was statistical difference in systolic blood pressure in LR3 group after the short-term treatment and before acupuncture. (2) Compared with sham acupoint, acupuncture at LR3 instantaneous effects in the functional connectivity with seed points was more concentrated in the frontal lobe. (3) Compared with instantaneous effects, acupuncture LR3 short-term effects in the functional connectivity with seed points had more regions in frontal lobe, cerebellum, and insula. These brain areas constituted a neural network structure with specific functions that could explain the mechanism of therapy in hypertension patients by LR3 acupoint.

Manual acupuncture at the SJ5 (Waiguan) acupoint shows neuroprotective effects by regulating expression of the anti-apoptotic gene Bcl-2

Acupuncture at the SJ5 (Waiguan) acupoint has neuroprotective effects in cerebral infarction, but the underlying mechanism remains poorly understood. Here, we analyzed gene expression in healthy rat cerebellum using a pathway-focused DNA microarray to screen 113 genes associated with 18 signal transduction pathways. After 20 minutes of acupuncture at SJ5, the expression of Bcl-2 and Birc1b mRNA was markedly increased. This was confirmed by real-time reverse transcription PCR. Furthermore, western blot analysis showed that Bcl-2 protein expression remained high in the cerebellum until at least 2 hours after cessation of acupuncture. These findings indicate that acupuncture at SJ5 exerts neuroprotective effects by regulating the expression of anti-apoptotic gene Bcl-2.

The Effects of Sa-am Acupuncture Simpo-jeongkyeok Treatment on the Blood Pressure, Pulse Rate, and Body Temperature

OBJECTIVES

The present study evaluated the effects of sa-am acupuncture (SAA) simpo-jeongkyeok (SPJK) treatment on the blood pressure (BP), pulse rate (PR), and body temperature (BT) of patients with hwa byung (HB).

METHODS

This patient assessor blind, randomized, placebo controlled trial included 50 volunteers, divided randomly into two groups. The treatment group underwent SPJK (PC9, LR1, PC3, KI10) while the control (sham) group received minimal needle insertion at non acupoints. The BP in both arms, PR, and BT at several acupoints were measured before and after treatment at the 1(st), 2(nd), 3(rd), and 4(th) visits and before treatment at the follow-up visit. We analyzed data by using the repeated measured analysis of variance (RM ANOVA), Mann-Whitney U, and wilcoxon signed rank tests; differences at P < 0.05 were considered significant.

RESULTS

No significant differences in the systolic blood pressure (SBP), diastolic blood pressure (DBP) and PR between the treatment and control group were observed at each visit. However, the decrease in the SBP for the treatment group before and after each visit was significantly higher than it was in the control group. The SBP in both arms in the treatment group was decreased between visits 1 and 2, 1 and 3, 1 and 4, and 1 and follow-up. The DBP in both arms and in the right arm between visits 1 and 3 in the treatment group showed decreases. A minimal BT increase for treatment at CV06 and CV12 and a minimal BT decrease for treatment at CV17 and (Ex) Yintang were found. Patients in the treatment group who visited more frequently experienced a greater decrease in the PR, but that effect was not maintained.

CONCLUSION

The results suggest that SAA SPJK treatment has instant positive effects on the BP, PR, and BT in patients with HB, but the effects on the BP and PR are not maintained.

MicroRNA Profiling Response to Acupuncture Therapy in Spontaneously Hypertensive Rats

MicroRNAs (miRNAs) are a group of endogenous noncoding RNAs that play important roles in many biological processes. This study aimed to check if miRNAs were involved in the response to acupuncture in rats. Microarray analysis was performed to compare the miRNA expression profiles of medulla in spontaneously hypertensive rats (SHRs) treated with or without acupuncture. Our microarray analysis identified 222 differentially expressed miRNAs in the medulla of SHRs treated with acupuncture at taichong acupoint. Among these miRNAs, 23 miRNAs with a significant difference were found in acupuncture-treated SHRs compared to untreated rats. These 23 miRNAs could regulate 2963 target genes which were enriched in at least 14 pathways based on our bioinformatic analysis. miRNA-339, miR-223, and miR-145 were downregulated in the medulla of SHRs compared to normotensive rats. Notably, these miRNAs were upregulated to basal levels in the medulla of SHRs treated with acupuncture at taichong in comparison with SHRs receiving acupuncture at nonacupoint group or SHRs without any treatment. Our findings have revealed significant changes of a panel of selective miRNAs in hypertensive rats treated at taichong acupoint. These data provide insights into how acupuncture elicits beneficial effects on hypertension.

Acupuncture for essential hypertension: a meta-analysis of randomized sham-controlled clinical trials

Background. Acupuncture is frequently advocated as an adjunct treatment for essential hypertension. The aim of this review was to assess its adjunct effectiveness in treating hypertension. Methods. We searched PubMed, the Cochrane Library, EMBASE, and the Chinese databases Sino-Med, CNKI, WanFang, and VIP through November, 2012, for eligible randomized controlled trials that compared acupuncture with sham acupuncture. Outcome measures were changes in diastolic (DBP) and systolic blood pressure (SBP). Results. A total of 4 randomized controlled trials were included. We found no evidence of an improvement with the fact that acupuncture relative to sham acupuncture in SBP change (n = 386; mean difference = -3.80 mmHg, 95% CI = -10.03-2.44 mmHg; I (2) = 99%), and an insignificant improvement in DBP change (n = 386; mean difference = -2.82 mmHg, 95% CI = -5.22-(-0.43) mmHg; I (2) = 97%). In subgroup analyses, acupuncture significantly improved both SBP and DBP in patients taking antihypertensive medications. Only minor acupuncture-related adverse events were reported. Conclusions. Our results are consistent with acupuncture significantly lowers blood pressure in patients taking antihypertensive medications. We did not find that acupuncture without antihypertensive medications significantly improves blood pressure in those hypertensive patients.

Connectomics: a new direction in research to understand the mechanism of acupuncture

Acupuncture has been used to treat various disorders in China and some other eastern countries for thousands of years. Nowadays, acupuncture is gradually accepted as an alternative and complementary method in western countries for its undeniable therapeutic effects. However, its central mechanism is still unclear. It is especially difficult to reveal how different regions in the brain influence one another and how the relationship is among these regions responding to acupuncture treatment. Recently, by applying neuroimaging techniques and network theory, acupuncture studies can make further efforts to investigate the influence of acupuncture on regional cerebral functional connectivity (FC) and the modulation on “acupuncture-related” networks. Connectomics appears to be a new direction in research to further understand the central mechanism underlying acupuncture. In this paper, an overview of connectomics application in acupuncture research will be discussed, with special emphasis on present findings of acupuncture and its influence on cerebral FC. Firstly, the connectomics concept and its significance on acupuncture will be outlined. Secondly, the commonly used brain imaging techniques will be briefly introduced. Thirdly, the influence of acupuncture on FC will be discussed in greater detail. Finally, the possible direction in forthcoming research will be reviewed by analyzing the limitation of present studies.