A Targeted Metabolomics MRM-MS Study on Identifying Potential Hypertension Biomarkers in Human Plasma and Evaluating Acupuncture Effects

Nuclear Magnetic Resonance Analysis Seeking for Metabolic Markers of Hypertension in Human Serum

Hypertension is a highly prevalent medical condition that occurs when blood pressure is too high, which greatly increases the risk of developing other cardiovascular diseases and is generally associated with higher rates of morbidity and mortality. Due to the silent/asymptomatic nature of hypertension, although the methods currently available to diagnose it are easy, they generally do not allow for an early diagnosis and an efficient prognosis to avoid irreversible damage in the medium or long term. In fact, an early diagnosis of hypertension would be crucial to decrease hypertension-associated mortality. Since metabolomics using NMR can provide a global measurement of various serum metabolites, it is very suitable for detecting novel biomarkers. We therefore analyzed serum metabolomic profiles among normotensive and hypertensive elderly individuals by NMR and identified new potential biomarkers for hypertension and associated diseases. We found higher levels of acetate, formate, and glycerol, and lower levels of glutamine, glycine, and sarcosine in individuals with hypertension. Therefore, these metabolites could be used for early diagnosis of hypertension to avoid comorbidities derived from hypertension and associated mortality.

Understanding Hypertension: A Metabolomic Perspective

Metabolomics approaches, such as Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS), have emerged as powerful tools for studying cardiovascular diseases (CVD), including hypertension. The use of biological fluids, like plasma and serum, has garnered significant interest due to their accessibility and potential in elucidating disease mechanisms. This review aims to summarize the current literature on the application of metabolomics techniques (FTIR, NMR, and MS) in the study of hypertension, focusing on their contributions to understanding disease pathophysiology, biomarker discovery, and therapeutic advancements. A comprehensive analysis of metabolomic studies was performed, with a particular emphasis on the diversity of altered metabolites associated with systolic blood pressure (SBP), diastolic blood pressure (DBP), and sex-related differences. Metabolomics techniques, including FTIR, NMR, and MS, provide comprehensive insights into the biochemical alterations underlying hypertension, such as amino acid and fatty acid metabolism impairment or inflammation and oxidative stress processes. This review underscores their role in advancing biomarker identification, deepening our understanding of disease mechanisms, and supporting the development of targeted therapeutic strategies. The integration of these tools highlights their potential in personalized medicine and their capacity to improve clinical outcomes.

Using Serum Metabolomic Signatures to Investigate Effects of Acupuncture on Pain-Fatigue-Sleep Disturbance in Breast Cancer Survivors

BACKGROUND/OBJECTIVES

Acupuncture is an efficacious integrative therapy for treating pain, fatigue, and sleep disturbance (the psychoneurological symptom cluster) in breast cancer survivors. However, the mechanisms underlying its effects remain unclear, and related metabolomics studies are limited. This study aimed to examine serum metabolite changes after acupuncture and their relationships to symptom improvement.

METHODS

Forty-two breast cancer survivors experiencing pain, fatigue, and sleep disturbance participated in a single-arm acupuncture trial. They received a 10-session acupuncture intervention over 5 weeks. Fasting blood samples and symptom surveys were collected before and after the acupuncture intervention, and untargeted metabolomics profiling was conducted on serum samples. Mixed-effects models adjusting for covariates (age, race, body mass index, and antidepressant use) were applied for analysis.

RESULTS

After acupuncture, there was a significant reduction in the psychoneurological symptom cluster (mean reduction = -6.2, p < 0.001).Bonferroni correction was applied to 40 independent metabolite clusters (α = 0.00125); cysteine-glutathione disulfide (p = 0.0006) significantly increased, and retinal (p = 0.0002) and cis-urocanate (p = 0.0005) were significantly decreased. Dimethyl sulfone (p = 0.00139) showed a trend towards reduction after acupuncture and its change (p = 0.04, β =1.97) was positively associated with reduction in the psychoneurological symptom cluster. Also, increased lauroylcarnitine (p = 0.0009) and decreased cytosine (p = 0.0008) can modulate the therapeutic effects of acupuncture.

CONCLUSIONS

Acupuncture demonstrates beneficial effects on the psychoneurological symptom cluster in breast cancer survivors. Dimethyl sulfone may be a promising mediator in the relationship between acupuncture and psychoneurological symptoms, while acylcarnitine metabolism may modulate the therapeutic effect of acupuncture.

Metabolomics as a promising technology for investigating external therapy of traditional Chinese medicine: A review

To demonstrate the potential for connecting metabolomics with traditional Chinese medicine (TCM) external therapies such as acupuncture and moxibustion, we conducted a literature review on metabolomics as a measurement tool for determining the efficacy of various TCM external therapies. Human research and animal models published in the last 10 years were summarized. The investigation can be classified as follows: Using metabolomics to study metabolic profile changes produced by stimulation of a specific acupoint ST36 indicates the perturbation of metabolites produced by stimulation of acupoints by external TCM treatments can be characterized by metabolomics; and Using metabolomics to reveal the molecular mechanism of various TCM external therapy methods to treat specific diseases such as digestive system disease, cardiovascular disease, neurological disorder, bone disease, and muscle fatigue. We conclude that metabolomics has considerable potential for comprehending TCM external treatment interventions, particularly from a systems perspective. Linking TCM external therapy research with metabolomics can further bridge detailed biological mechanisms with the systematic effect of TCM external therapy, hence providing new paths for gaining a deeper knowledge of the importance of TCM in the treatment and maintenance of health.

Impact of Acupuncture on Human Metabolomic Profiles: A Systematic Review

BACKGROUND/OBJECTIVES

Metabolomics provides insights into the biological underpinnings of disease development and treatment. This systematic review investigated the impact of acupuncture on metabolite levels and associated metabolic pathways using a metabolomic approach.

METHODS

Five databases (i.e., PubMed, Embase, Scopus, CINAHL, and Cochrane Central) were searched using terms such as "acupuncture" and "metabolites" to retrieve relevant journal articles published through January 2024. Studies utilizing mass spectrometry or nuclear magnetic resonance were included. Risk of bias was evaluated using the Cochrane Risk of Bias tool and the Newcastle-Ottawa scale. Metabolic pathway analysis was conducted using MetaboAnalyst 6.0 to identify common significant pathways affected by acupuncture. Additionally, subgroup pathway enrichment analysis identified metabolites significantly altered in more than two studies.

RESULTS

Among 4019 articles, 22 studies met inclusion criteria, examining changes in metabolomic biomarkers before and after acupuncture for various diseases and symptoms. A total of 226 metabolites showed significant changes, with 14 common metabolites altered in more than two studies (glutamine, androsterone glucuronide, choline, citric acid, decanoylcarnitine, estrone, glutathione, glycine, hypoxanthine, lactic acid, pyruvic acid, serine, proline, and sn-glycero-3-phosphocholine). Common pathways affected by acupuncture were glycine, serine, and threonine metabolism, glutathione metabolism, arginine biosynthesis, and glyoxylate and dicarboxylate metabolism.

CONCLUSIONS

This review provides insights of the metabolomic mechanisms underlying acupuncture, highlighting its impact on specific metabolic pathways. Recognizing these changes can enhance acupuncture's effectiveness and support the development of personalized treatments. The findings underscore metabolomics as a valuable tool for understanding and optimizing acupuncture for various diseases and symptoms.

Causal association between blood metabolites and risk of hypertension: a Mendelian randomization study

Background

Previous studies have indicated a strong link between blood metabolites and hypertension, however the causality of metabolites and hypertension is unknown.

Methods

Two-sample Mendelian randomization (MR) analysis was performed to assess the causal relationship between 486 blood metabolites and essential hypertension (EHT). Blood metabolite GWAS data was utilized as the exposure, with EHT GWAS data as the outcome. To further verify the results, another different source of EHT GWAS data was repeatedly analyzed. The major MR analytic approach used to determine causality was inverse variance weighted (IVW), with MR-Egger, Weighted Median, and MR-PRESSO models serving as supplements. We used the Cochran Q test to examine heterogeneity. Horizontal pleiotropy was examined using MR-Egger intercept and MR-PRESSO global test. The MR Steiger test confirmed the causal relationship between blood metabolites and EHT.

Results

In this study, nine blood metabolites associated with EHT were preliminarily identified by MR analysis, including four known metabolites (N-acetylornithine, X-12510-2-aminooctanoic acid, creatine, hexadecanedioate) and five unknown metabolites. Then another source of EHT GWAS data was repeatedly analyzed for further verification, and two overlapped metabolites (N-acetylornithine, X-12510-2-aminooctanoic acid) were found. There was a negative correlation between N-acetylornithine and EHT (OR = 0.987, 95% CI = 0.980-0.993, P = 1.01 × 10-4), Cochran's Q test suggested there was no heterogeneity (Q = 31.7586, P = 0.1331), MR-Egger intercept and MR-PRESSO global test suggested there was no horizontal pleiotropy (P > 0.05), Leave-one-out analysis indicated that no single single-nucleotide polymorphism (SNP) had a significant effect on the results, and MR Steiger test confirmed that the direction of causality was correct (P < 0.001). There was a negative correlation between X-12510-2-aminooctanoic acid and EHT (OR = 0.982, 95% CI = 0.972-0.993, P = 0.0017), and there was no evidence of heterogeneity or pleiotropy in multiple sensitivity analyses.

Conclusion

The study discovered some blood metabolites causally linked to EHT, which might lead to new understandings of the pathophysiology of hypertension.

Efficacy of acupuncture for hypertension in the elderly: a systematic review and meta-analysis

Background

Hypertension has now developed into a major public health problem worldwide. Under the existing antihypertensive drug treatment paradigm, problems such as decreasing drug resistance and increasing drug side effects can occur for elderly patients. Acupuncture, a core technique in the non-pharmacological treatment of Chinese medicine, plays an important role in the treatment of elevated blood pressure.

Objective

This study aimed to systematically evaluate the effect of acupuncture alone or in combination with antihypertensive drugs on the efficiency of reducing blood pressure and controlling blood pressure in elderly patients with hypertension.

Methods

Articles of randomized controlled trials of acupuncture for hypertension in the elderly published before November 2022 were searched in 7 databases. The methodological quality of the literature was evaluated using the Cochrane Risk of Bias Assessment Tool. The primary outcome was the efficiency rate of blood pressure reduction, and the secondary outcome was the change in blood pressure after treatment.

Results

This study conducted a systematic review and meta-analysis of 12 randomized controlled trials with a total of 1,466 subjects. Among the primary outcome-efficiency rate, acupuncture-only treatment (RR = 1.11, 95% CI: 1.03-1.20, P < 0.01) and acupuncture combined with antihypertensive drug treatment (RR = 1.18, 95% CI: 1.06-1.31, P < 0.01) were significantly different compared with drugs-only treatment. Among the secondary outcomes, SBP (MD: -4.85, 95% CI: -10.39 to -0.69, P = 0.09) and DBP (MD: -1.45, 95% CI: -5.35 to 2.45, P = 0.47) show no significant difference between acupuncture-only treatment and drug-only treatment. Compared to drugs-only treatment, acupuncture plus drugs has more significant efficiency in lowering SBP (MD: -9.81, 95% CI: -13.56 to -6.06, P < 0.01) and DBP (MD: -7.04, 95% CI: -10.83 to -3.24, P < 0.01).

Conclusion

For elderly patients with hypertension, acupuncture-only treatment has the same efficiency and antihypertensive effect compared to drug therapy and acupuncture plus drugs outperforms drugs-only treatment. If the patients receive therapy with less frequency per week and longer duration, there will be a more obvious antihypertensive effect. Due to the methodological defects in the included study and the limited sample size of this paper, more well-designed randomized controlled trials are needed for verification.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022376407, PROSPERO (CRD42022376407).

Metabolomics reveals serum metabolic signatures in H-type hypertension based on mass spectrometry multi-platform

BACKGROUND

H-type hypertension (HHT) is a disease combined with hyperhomocysteinaemia and hypertension (HT). This study aims to find specific metabolic changes and reveal the pathophysiological mechanism of HHT, which provide the theoretical basis for the early prevention and treatment of HHT.

METHODS

Serum samples from three groups including 53 HHT patients, 36 HT patients and 46 healthy controls (HC) were collected. The targeted and untargeted metabolomics analyses were performed to determine the metabolic changes. Based on multivariate statistical analysis, the serum potential metabolites were screened and different metabolic pathways were explored.

RESULTS

Our results demonstrated that there were 28 important potential metabolites for distinguishing HT from HHT patients. Metabolic pathway analysis showed that the different metabolic pathways between HHT and HC group were arginine biosynthesis, arginine and proline metabolism, and tyrosine metabolism. The changed metabolic pathway of HT and HC group included linoleic acid metabolism. The specific metabolic pathways of HT-HHT comparison group had phenylalanine metabolism; phenylalanine, tyrosine and tryptophan biosynthesis; glycine, serine and threonine metabolism.

CONCLUSIONS

Metabolomics analysis by mass spectrometry multi-platform revealed the differences of metabolic profiles between HHT and HT subjects. This work laid the groundwork for understanding the aetiology of HHT, and these findings may provide the useful information for explaining the HHT metabolic alterations and try to prevent HHT.

Metabolic profile of blood serum in experimental arterial hypertension

The etiology of essential hypertension is intricate, since it employs simultaneously various body systems related to the regulation of blood pressure in one way or another: the sympathetic nervous system, renin-angiotensin-aldosterone and hypothalamic-pituitary-adrenal systems, renal and endothelial mechanisms. The pathogenesis of hypertension is influenced by a variety of both genetic and environmental factors, which determines the heterogeneity of the disease in human population. Hence, there is a need to perform research on experimental models - inbred animal strains, one of them being ISIAH rat strain, which is designed to simulate inherited stress-induced arterial hypertension as close as possible to primary (or essential) hypertension in humans. To determine specific markers of diseases, various omics technologies are applied, including metabolomics, which makes it possible to evaluate the content of low-molecular compounds - amino acids, lipids, carbohydrates, nucleic acids fragments - in biological samples available for clinical analysis (blood and urine). We analyzed the metabolic profile of the blood serum of male ISIAH rats with a genetic stress-dependent form of arterial hypertension in comparison with the normotensive WAG rats. Using the method of nuclear magnetic resonance spectroscopy (NMR spectroscopy), 56 metabolites in blood serum samples were identified, 18 of which were shown to have significant interstrain differences in serum concentrations. Statistical analysis of the data obtained showed that the hypertensive status of ISIAH rats is characterized by increased concentrations of leucine, isoleucine, valine, myo-inositol, isobutyrate, glutamate, glutamine, ornithine and creatine phosphate, and reduced concentrations of 2-hydroxyisobutyrate, betaine, tyrosine and tryptophan. Such a ratio of the metabolite concentrations is associated with changes in the regulation of glucose metabolism (metabolic markers - leucine, isoleucine, valine, myo-inositol), of nitric oxide synthesis (ornithine) and catecholamine pathway (tyrosine), and with inflammatory processes (metabolic markers - betaine, tryptophan), all of these changes being typical for hypertensive status. Thus, metabolic profiling of the stress-dependent form of arterial hypertension seems to be an important result for a personalized approach to the prevention and treatment of hypertensive disease.

Research trends of acupuncture therapy for hypertension over the past two decades: a bibliometric analysis

Acupuncture has already been extensively utilized to treat high blood pressure (hypertension) in several nations. Nevertheless, the bibliometric research on the worldwide usage of acupuncture for hypertension is mostly unclear. As a result, our objective for the research aimed to investigate the present state as well as developments in the global usage of acupuncture on hypertension during the last 20 years using CiteSpace (5.8.R2). The Web of Science (WOS) database examined papers on acupuncture treatment of hypertension from 2002 to 2021. We examined the number of publications, cited journals, nations/regions, organizations, authors, cited authors, cited references, and keywords utilizing CiteSpace. The record of 296 documents was obtained between 2002 and 2021. The quantity and frequency of annual publications rose gradually. Regarding frequency and centrality of citations, Circulation and Clin Exp Hypertens (Clinical and Experimental Hypertension) scored top and second respectively. China had the most publications among countries/regions, as well as the five largest institutions were also in China. Cunzhi Liu was the most productive author, while P Li was the most referenced author. XF Zhao produced the first article inside the quantity of cited references classification. 'Electroacupuncture' had a significant frequency with centrality for the keywords, which suggested electroacupuncture is a popular treatment in this field. In the treatment of hypertension, electroacupuncture has a beneficial effect on reducing blood pressure. However, because of the many different applications of electroacupuncture frequencies in research, whether the electroacupuncture frequency is connected to the therapeutic impact should be given more significant consideration. The findings of this bibliometric analysis give an overview of the present state as well as developments of clinical studies on acupuncture for hypertensive patients during the last two decades, which could assist researchers in identifying hot subjects and exploring novel directions in further study within the field.

Comparison of the Chemical Components, Efficacy and Mechanisms of Action of Chrysanthemum morifolium Flower and Its Wild Relative Chrysanthemum indicum Flower against Liver-Fire Hyperactivity Syndrome of Hypertension via Integrative Analyses

To clarify the differences in the clinical application scope of Chrysanthemum morifolium flower (CMF) and Chrysanthemum indicum flower (CIF), two herbs of similar origin, an integrated strategy of network pharmacology, molecular pharmacology, and metabolomics was employed, with a view to investigating the commonalities and dissimilarities in chemical components, efficacy and mechanisms of action. Initial HPLC-Q-TOF-MS analysis revealed that CMF and CIF had different flavonoid constituents. The biological processes underlying the therapeutic effects of CMF and CIF on liver-fire hyperactivity syndrome of hypertension (LFHSH) were predicted to be related to inflammatory response, fatty acid production, and other pathways based on network pharmacology analysis. ELISA, molecular docking, Western blot, and metabolomics techniques showed similar effects of CMF and CIF in lowering blood pressure, resistance to tissue, organ and functional damage, and dyslipidemia. However, distinct effects were found in the regulation of inflammatory response, PI3K-Akt and NF-κB signaling pathways, lipid anabolism, renin-angiotensin system, and metabolic abnormalities. The comparable efficacies of CMF and CIF, despite having distinct mechanisms of action, may be attributed to the integration and counteraction of their different regulating capabilities on the above anti-LFHSH mechanisms. This study offers a vital platform for assessment of differential and precise applications of herbs of close origin with similar but slightly different medicinal properties, and provides a research strategy for bridging Chinese medicine and modern precision medicine.

Influence of electroacupuncture on ghrelin and the phosphoinositide 3-kinase/protein kinase B/endothelial nitric oxide synthase signaling pathway in spontaneously hypertensive rats

OBJECTIVE

To investigate the influence of electroacupuncture (EA) on ghrelin and the phosphoinositide 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling pathway in spontaneously hypertensive rats (SHRs).

METHODS

Eight Wistar-Kyoto rats were used as the healthy blood pressure (BP) control (normal group), and 32 SHRs were randomized into model group, EA group, EA plus ghrelin group (EA + G group), and EA plus PF04628935 group (a potent ghrelin receptor blocker; EA + P group) using a random number table. Rats in the normal group and model group did not receive treatment, but were immobilized for 20 min per day, 5 times a week, for 4 continuous weeks. SHRs in the EA group, EA + G group and EA + P group were immobilized and given EA treatment in 20 min sessions, 5 times per week, for 4 weeks. Additionally, 1 h before EA, SHRs in the EA + G group and EA + P group were intraperitoneally injected with ghrelin or PF04628935, respectively, for 4 weeks. The tail-cuff method was used to measure BP. After the 4-week intervention, the rats were sacrificed by cervical dislocation, and pathological morphology of the abdominal aorta was observed using hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of ghrelin, nitric oxide (NO), endothelin-1 (ET-1) and thromboxane A2 (TXA2) in the serum. Isolated thoracic aortic ring experiment was performed to evaluate vasorelaxation. Western blot was used to measure the expression of PI3K, Akt, phosphorylated Akt (p-Akt) and eNOS proteins in the abdominal aorta. Further, quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to measure the relative levels of mRNA expression for PI3K, Akt and eNOS in the abdominal aorta.

RESULTS

EA significantly reduced the systolic BP (SBP) and diastolic BP (DBP) (P < 0.05). HE staining showed that EA improved the morphology of the vascular endothelium to some extent. Results of ELISA indicated that higher concentrations of ghrelin and NO, and lower concentrations of ET-1 and TXA2 were presented in the EA group (P < 0.05). The isolated thoracic aortic ring experiment demonstrated that the vasodilation capacity of the thoracic aorta increased in the EA group. Results of Western blot and qRT-PCR showed that EA increased the abundance of PI3K, p-Akt/Akt and eNOS proteins, as well as expression levels of PI3K, Akt and eNOS mRNAs (P < 0.05). In the EA + G group, SBP and DBP decreased (P < 0.05), ghrelin concentrations increased (P < 0.05), and the concentrations of ET-1 and TXA2 decreased (P < 0.05), relative to the EA group. In addition, the levels of PI3K and eNOS proteins, the p-Akt/Akt ratio, and the expression of PI3K, Akt and eNOS mRNAs increased significantly in the EA + G group (P < 0.05), while PF04628935 reversed these effects.

CONCLUSION

EA effectively reduced BP and protected the vascular endothelium, and these effects may be linked to promoting the release of ghrelin and activation of the PI3K/Akt/eNOS signaling pathway.

Influence of Genetic West African Ancestry on Metabolomics among Hypertensive Patients

Patients with higher genetic West African ancestry (GWAA) have hypertension (HTN) that is more difficult to treat and have higher rates of cardiovascular diseases (CVD) and differential responses to antihypertensive drugs than those with lower GWAA. The mechanisms underlying these disparities are poorly understood. Using data from 84 ancestry-informative markers in US participants from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 trials, the GWAA proportion was estimated. Using multivariable linear regression, the baseline levels of 886 metabolites were compared between PEAR participants with GWAA < 45% and those with GWAA ≥ 45% to identify differential metabolites and metabolic clusters. Metabolites with a false discovery rate (FDR) < 0.2 were used to create metabolic clusters, and a cluster analysis was conducted. Differential clusters were then tested for replication in PEAR-2 participants. We identified 353 differential metabolites (FDR < 0.2) between PEAR participants with GWAA < 45% (n = 383) and those with GWAA ≥ 45% (n = 250), which were used to create 24 metabolic clusters. Of those, 13 were significantly different between groups (Bonferroni p < 0.002). Four clusters, plasmalogen and lysoplasmalogen, sphingolipid metabolism and ceramide, cofactors and vitamins, and the urea cycle, were replicated in PEAR-2 (Bonferroni p < 0.0038) and have been previously linked to HTN and CVD. Our findings may give insights into the mechanisms underlying HTN racial disparities.

Effect of Acupuncture on Blood Pressure and Metabolic Profile Among Patients With Essential Hypertension: Protocol of a Randomized Clinical Trial

Essential hypertension is a polygenic cardiovascular disease that is associated with maladaptive metabolic changes. Acupuncture as a non-pharmacologic intervention is used to lower blood pressure and improve metabolic dysfunction. However, such effects have not been clinically characterized. We will conduct a randomized clinical trial to evaluate the antihypertensive effect of acupuncture among patients with essential hypertension and determine the associated metabolic improvements. This study is a phase II, two-arm, randomized, sham-controlled trial (Trial registration: ChiCTR2100043737), in which biospecimens will be collected for metabolic profiling. A total of 64 patients with a clinical diagnosis of essential hypertension will be randomly assigned to either the acupuncture or the sham acupuncture group in a 1:1 ratio. All participants will receive 10 treatments over 4 weeks, with three sessions per week for the first 2 weeks and two sessions per week for the remaining weeks. The primary outcome is the change of the systolic and diastolic blood pressure measured by the 24-h ambulatory blood pressure monitoring from baseline to 4 weeks. Secondary outcomes include the circadian rhythm of blood pressure, sleep quality measured by the Insomnia Severity Index, cognitive function measured by the Montreal Cognitive Assessment, and others. Fasting blood serum and urine samples will be collected at baseline and 4 weeks for targeted and untargeted metabolomics analysis. We will use the mixed-effects model and other related bioinformatics approaches to analyze the clinical and metabolome data. This metabolomic-based trial will provide important clinical data regarding the efficacy of acupuncture for essential hypertension to better inform evidence-based care delivery for hypertension patients. Moreover, the findings will offer important insights into the mechanism of action of acupuncture for hypertension by revealing its effect on metabolism. The results of this study will be used to inform the design of a statistically powered, multicenter, randomized trial. We will publish the study findings in peer-reviewed journals. The ethical approval of this study has been reviewed and approved by the Sichuan Regional Ethics Review Committee on Traditional Chinese Medicine (ID: 2021KL-006). The outcomes of the trial will be disseminated through peer-reviewed publications.

Synaptic Protein Phosphorylation Networks Are Associated With Electroacupuncture-Induced Circadian Control in the Suprachiasmatic Nucleus

Phosphorylation is one of the most important posttranslational modifications and regulates the physiological process. While recent studies highlight a major role of phosphorylation in the regulation of sleep–wake cycles to a lesser extent, the phosphoproteome in the suprachiasmatic nucleus (SCN) is not well-understood. Herein, we reported that the EA treatment elicits partial reparation of circadian rhythmicity when mice were exposure to constant darkness for long time. We investigated the effects of EA on circadian rhythms in constant darkness between EA stimulation and free-running control. Next, mass spectrometry–based phosphoproteome was utilized to explore the molecular characteristics of EA-induced phosphorylation modification in the SCN. A total of 6,192 distinct phosphosites on 2,488 proteins were quantified. Functional annotation analysis and protein–protein interaction networks demonstrated the most significant enriched phosphor-proteins and phosphosites involved in postsynapse and glutamatergic synapse. The current data indicated that most of the altered molecules are structural proteins. The target proteins, NMDAR and CAMK2, were selected for verification, consistent with the results of LC–MS/MS. These findings revealed a complete profile of phosphorylation modification in response to EA.

Metabolic Profiling and Metabolites Fingerprints in Human Hypertension: Discovery and Potential

Early detection of pathogenesis through biomarkers holds the key to controlling hypertension and preventing cardiovascular complications. Metabolomics profiling acts as a potent and high throughput tool offering new insights on disease pathogenesis and potential in the early diagnosis of clinical hypertension with a tremendous translational promise. This review summarizes the latest progress of metabolomics and metabolites fingerprints and mainly discusses the current trends in the application in clinical hypertension. We also discussed the associated mechanisms and pathways involved in hypertension's pathogenesis and explored related research challenges and future perspectives. The information will improve our understanding of the development of hypertension and inspire the clinical application of metabolomics in hypertension and its associated cardiovascular complications.

Effect of Yishenjiangyafang on Plasma Metabolomics in Senile Spontaneously Hypertensive Rats

Objectives

Yishenjiangyafang is a traditional Chinese medicine used to clinically treat hypertension. This study aimed to explore the effect of yishenjiangyafang on plasma metabolomics in senile spontaneously hypertensive rats (SHRs).

Methods

Twelve 50-week-old SHR (6 males and 6 females) were randomly divided into two groups: a treatment group, in which rats were intragastrically administered with yishenjiangyafang (10.08 g kg⁻¹·d⁻¹), and a model group, in which all SHRs were administered the same volume of saline. Six age- and gender-matched Wistar–Kyoto (WKY) rats were used as the control group. Treatment was given for 6 days per week and lasted for 8 weeks. Systolic and diastolic blood pressures of the rats were measured with the noninvasive tail artery pressure measurement system. An ultraperformance liquid chromatography quadruple electrostatic field orbit (UPLC-Q-Exactive) was used to determine metabolite changes in the plasma of SHR rats before and after yishenjiangyafang treatment in the treatment group as well as in the model and control groups.

Results

After yishenjiangyafang treatment, SHRs had significant lower blood pressure. Using UPLC-Q-Exactive, we identified 26 metabolic targets of yishenjiangyafang in aged SHRs and revealed that yishenjiangyafang targeted four major metabolic pathways, linoleic acid metabolism, glycerophospholipid metabolism, arginine and proline metabolism, and steroid hormone biosynthesis.

Conclusion

Yishenjiangyafang decreases the blood pressure of SHRs at least in part through targeting of four major metabolic pathways. Our study illustrates mechanisms underlying the clinical application of yishenjiangyafang in the treatment of hypertensive patients.

Identification of biomarkers for essential hypertension based on metabolomics

AIM

Essential hypertension (EH) is one of the most important public health problems worldwide. However, the pathogenesis of EH is unclear and early diagnostic methods are lacking. Metabolomics demonstrates great potential for biomarker discovery and the mechanistic exploration of metabolic diseases.

DATA SYNTHESIS

This review included human and animal metabolomics studies related to EH in the PubMed and Web of Science databases between February 1996 and May 2020. The study designs, EH standards, and reported metabolic biomarkers were systematically examined and compared. The pathway analysis was conducted through the online software MetaboAnalyst 4.0. Twenty-two human studies and fifteen animal studies were included in this systematic review. There were many frequently reported biomarkers with consistent trends (e.g., pyruvate, lactic acid, valine, and tryptophan) in human and animal studies, and thus had potential as biomarkers of EH. In addition, several shared metabolic pathways, including alanine, aspartate, and glutamate metabolism, aminoacyl-tRNA biosynthesis, and arginine biosynthesis, were identified in human and animal metabolomics studies. These biomarkers and pathways, closely related to insulin resistance, the inflammatory state, and impaired nitric oxide production, were demonstrated to contribute to EH development.

CONCLUSIONS

This study summarized valuable metabolic biomarkers and pathways that could offer opportunities for the early diagnosis or prediction of EH and the discovery of the metabolic mechanisms of EH.

Mechanism of SQQX Decoction's Protective Effect on SHR: A Serum Metabolomics-Based Analysis

SangQiQingXuan (SQQX) decoction is a pharmaceutical preparation exerting good therapeutic efficacy on high blood pressure (BP) and has widely been accepted in primarily hypertensive patients as a herbal formula prescribed by Professor Li Huang from China-Japan Friendship Hospital according to her 30-year clinical experience. A previous study showed that SQQX could reduce BP by decreasing levels of many inflammatory factors such as transforming growth factor beta (TGFβ) and elevating peroxisome proliferator activated receptor (PPAR) expression. However, a research focusing on SQQX's protection against HTN from a metabolomic perspective has never been done before. This study aimed to figure out the metabolic profiling variations due to oral administration of SQQX in spontaneous hypertensive rat (SHR) models and to find out the optimal dosage of SQQX. SHR in the intervention group orally received SQQX extract of three doses, namely, the low- (5.25 g/kg/d), middle- (10.5 g/kg/d), and high-dosage groups (21 g/kg/d) for 90 days. Rats were sacrificed at the end of the experiment, and their serum was collected for further examination. Serum metabolic profiling variations were analyzed using ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC/MS). Results showed that dealing with SQQX remarkably decreased systolic blood pressure (SBP) of SHRs and the high-dosage group was with the best therapeutic effect where a total of 11 metabolites were markedly changed in contrast to the model group. Orthogonal partial least square discriminant analysis (OPLS-DA) score plot showed that the 5 groups of serum samples were divided into 5 categories, and the metabolic trajectory of the high-dosage SQQX group was inclined to move to the control group. Glycochenodeoxycholic acid, nicotinamide-N-oxide, and tryptophan betaine might be biomarkers that specifically marked the protective effects of SQQX against high BP mainly involving in cholesterol metabolism, primary bile acid biosynthesis, bile secretion, and nicotinate and nicotinamide metabolism. To conclude, SQQX has a protective effect on SHR, which may be partially correlated to restoration of perturbed metabolism in serum.

Metabolomics of Interstitial Fluid, Plasma and Urine in Patients with Arterial Hypertension: New Insights into the Underlying Mechanisms

There is growing evidence that lymphatic system plays a pivotal role in the pathogenesis of hypertension. Here, for the first time, the metabolome of interstitial fluid is analyzed in patients with arterial hypertension. Due to ethical issues to obtain human interstitial fluid samples, this study included only oncological patients after axillary lymph node dissection (ALND). These patients were matched into hypertensive (n = 29) and normotensive (n = 35) groups with similar oncological status. Simultaneous evaluation of interstitial fluid, plasma, and urine was obtained by combining high-resolution proton nuclear magnetic resonance (¹H NMR) spectroscopy with chemometric analysis. Orthogonal partial least squares discriminant analysis (OPLS-DA) provided a clear differentiation between the hypertension and normotensive group, with the discrimination visible in each biofluid. In interstitial fluid nine potential metabolomic biomarkers for hypertension could be identified (creatinine, proline, pyroglutamine, glycine, alanine, 1-methylhistidine, the lysyl group of albumin, threonine, lipids), seven distinct markers in plasma (creatinine, mannose, isobutyrate, glycine, alanine, lactate, acetate, ornithine), and seven respectively in urine (methylmalonate, citrulline, phenylacetylglycine, fumarate, citrate, 1-methylnicotinamide, trans-aconitate). Biomarkers in plasma and urine allowed for the identification of specific biochemical pathways involved in hypertension, as previously suggested. Analysis of the interstitial fluid metabolome provided additional biomarkers compared to plasma or urine. Those biomarkers reflected primarily alterations in the metabolism of lipids and amino acids, and indicated increased levels of oxidative stress/inflammation in patients with hypertension.

Effects of Retinal Transcription Regulation After GB20 Needling Treatment in Retina With Optic Neuritis

Optic neuritis (ON) is one of the most frequent symptoms of multiple sclerosis (MS) that results in progressive loss of axons and neurons. In clinical trials of Traditional Chinese Medicine, needling at the GB20 acupoint has been widely used for the treatment of ocular diseases, including ON. However, the molecular mechanisms of needling at this site are still unclear. In this study, we generated an experimental autoimmune encephalomyelitis (EAE) mouse model and investigated the effects of needling treatment at the GB20 acupoint on retina with EAE-associated ON. RNA sequencing of the retinal transcriptome revealed that, of the 234 differentially expressed genes induced by ON, 100 genes were upregulated, and 134 genes were downregulated by ON, while needling at the GB20 acupoint specifically reversed the expression of 21 genes compared with control treatment at GV16 acupoint. Among the reversed genes, Nr4a3, Sncg, Uchl1, and Tppp3 were involved in axon development and regeneration and were downregulated by ON, indicating the beneficial effect of needling at GB20. Further gene ontology (GO) enrichment analysis revealed that needling at GB20 affected the molecular process of Circadian rhythm in mouse retina with ON. Our study first reported that needling treatment after ON at the GB20 acupoint regulated gene expression of the retina and reversed the expression of downregulated axon development-related genes. This study also demonstrated that GV16 was a perfect control treatment site for GB20 in animal research. Our study provided a scientific basis for needling treatments at GB20 for ocular diseases.

Global Plasma Metabolomics to Identify Potential Biomarkers of Blood Pressure Progression

Objective:

The pathophysiology of hypertension remains incompletely understood. We investigated associations of circulating metabolites with longitudinal blood pressure (BP) changes in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort and validated the findings in the Uppsala Longitudinal Study of Adult Men cohort.

Approach and Results:

Circulating metabolite levels were assessed with liquid- and gas-chromatography coupled to mass spectrometry among persons without BP-lowering medication at baseline. We studied associations of baseline levels of metabolites with changes in BP levels and the clinical BP stage between baseline and a follow-up examination 5 years later. In the discovery cohort, we investigated 504 individuals that contributed with 757 observations of paired BP measurements. The mean baseline systolic and diastolic BPs were 144 (19.7)/76 (9.7) mm Hg, and change in systolic and diastolic BPs were 3.7 (15.8)/−0.5 (8.6) mm Hg over 5 years. The metabolites associated with diastolic BP change were ceramide, triacylglycerol, total glycerolipids, oleic acid, and cholesterylester. No associations with longitudinal changes in systolic BP or BP stage were observed. Metabolites with similar structures to the 5 top findings in the discovery cohort were investigated in the validation cohort. Diacylglycerol (36:2) and monoacylglycerol (18:0), 2 glycerolipids, were associated with diastolic BP change in the validation cohort.

Conclusions:

Circulating baseline levels of ceramide, triacylglycerol, total glycerolipids, and oleic acid were positively associated with longitudinal diastolic BP change, whereas cholesterylester levels were inversely associated with longitudinal diastolic BP change. Two glycerolipids were validated in an independent cohort. These metabolites may point towards pathophysiological pathways of hypertension.

Liquid chromatography-mass spectrometry-based metabolomics analysis of flavonoids and anthraquinones in Fagopyrum tataricum L. Gaertn. (tartary buckwheat) seeds to trace morphological variations

Polyphenols (flavonoids and anthraquinones) are one of the most important phytochemicals in Fagopyrum tataricum L. Gaertn. (tartary buckwheat). However, the relationship between the polyphenols of tartary buckwheat seeds and their morphological variations is unclear. We developed a liquid chromatography-mass spectrometry-based targeted metabolomics method to study the chemical profiles of 60 flavonoids and 11 anthraquinones in 40 seed cultivars (groats and hulls). Both flavonoids and anthraquinones were related to variations in seed color; the fold change from yellowish-brown to black seeds was 1.24-1.55 in groats and 0.26-0.76 in hulls. Only flavonoids contributed to significant differences in seed shape; the fold change from long to short seeds was 1.29-1.78 in groats and 1.39-1.44 in hulls. Some differential metabolites were identified at higher concentrations in hulls than in groats. This study provides new insights into differences in polyphenols among tartary buckwheat seeds with different color and shape.

Acupuncture at LR3 and KI3 shows a control effect on essential hypertension and targeted action on cerebral regions related to blood pressure regulation: a resting state functional magnetic resonance imaging study

OBJECTIVE

The aim of this study was to investigate the effects of acupuncture at LR3 and KI3 on hypertension at different time points and on related cerebral regions using resting-state functional magnetic resonance imaging (rs-fMRI).

METHODS

We randomly divided 29 subjects into two groups: Group A (receiving acupuncture at LR3 + KI3; 15 subjects) and group B (receiving acupuncture at LR3 and a sham location not corresponding to any traditional acupuncture point; 14 subjects). Acupuncture was performed. Blood pressure (BP) changes were recorded and analyzed using SPSS 20.0 statistical software. We used a 3.0T MRI scanner and standard GE 8 channel head coil to collect whole brain fMRI data in both groups. Data analysis and processing was based on the R2009a MATLAB platform. REST 1.8 software was used to analyze the whole brain amplitude of low-frequency fluctuation (ALFF).

RESULTS

After acupuncture, a statistically significant reduction in BP at different time points was observed in group A. In group B, a statistically significant reduction was found only in diastolic blood pressure (DBP) and was not sustained. Acupuncture at LR3 + KI3 specifically affected brain areas involved in BP regulation, as well as those involved in auditory sense, speech, vision, movement and sensation.

CONCLUSION

Acupuncture at LR3 + KI3 showed positive immediate and long-term effects on BP, particularly systolic blood pressure (SBP). After ALFF analysis, we concluded that LR3 + KI3 activates brain areas related to BP regulation. In addition, after acupuncture at LR3 + KI3, a highly targeted effect was observed in brain areas associated with BP. In addition, extracerebral areas involving vision, motion control, cognition and hearing were activated, which could potentially contribute to the mitigation of hypertensive complications in patients in an advanced stage of the disease.

An MRM-Based Multiplexed Quantification Assay for Human Adipokines and Apolipoproteins

Adipokines and apolipoproteins are key regulators and potential biomarkers in obesity and associated diseases and their quantitative assessment is crucial for functional analyses to understand disease mechanisms. Compared to routinely used ELISAs, multiple reaction monitoring (MRM)-based mass spectrometry allows multiplexing and detection of proteins for which antibodies are not available. Thus, we established an MRM method to quantify 9 adipokines and 10 apolipoproteins in human serum. We optimized sample preparation by depleting the two most abundant serum proteins for improved detectability of low abundant proteins. Intra-day and inter-day imprecision were below 16.5%, demonstrating a high accuracy. In 50 serum samples from participants with either normal weight or obesity, we quantified 8 adipokines and 10 apolipoproteins. Significantly different abundances were observed for five adipokines (adipsin, adiponectin, chemerin, leptin, vaspin) and four apolipoproteins (apo-B100/-C2/-C4/-D) between the body mass index (BMI) groups. Additionally, we applied our MRM assay to serum samples from normal weight children and human adipocyte cell culture supernatants to proof the feasibility for large cohort studies and distinct biological matrices. In summary, this multiplexed assay facilitated the investigation of relationships between adipokines or apolipoproteins and phenotypes or clinical parameters in large cohorts, which may contribute to disease prediction approaches in the future.

Impaired Autonomic Nervous System-Microbiome Circuit in Hypertension

Hypertension affects an estimated 103 million Americans, yet gaps in knowledge continue to limit its successful management. Rapidly emerging evidence is linking gut dysbiosis to many disorders and diseases including hypertension. The evolution of the -omics techniques has allowed determination of the abundance and potential function of gut bacterial species by next-generation bacterial sequencing, whereas metabolomics techniques report shifts in bacterial metabolites in the systemic circulation of hypertensive patients and rodent models of hypertension. The gut microbiome and host have evolved to exist in balance and cooperation, and there is extensive crosstalk between the 2 to maintain this balance, including during regulation of blood pressure. However, an understanding of the mechanisms of dysfunctional host-microbiome interactions in hypertension is still lacking. Here, we synthesize some of our recent data with published reports and present concepts and a rationale for our emerging hypothesis of a dysfunctional gut-brain axis in hypertension. Hopefully, this new information will improve the understanding of hypertension and help to address some of these knowledge gaps.

Emerging Applications of Metabolomics in Traditional Chinese Medicine Treating Hypertension: Biomarkers, Pathways and More

Hypertension is a prevalent, complex, and polygenic cardiovascular disease, which is associated with increased mortality and morbidity. Across the world, traditional Chinese medicine (TCM) constituted by herbal medicine and non-pharmacological therapies is used to assist blood pressure management. Though widely accepted in daily practice, its mechanism remains largely unknown. Recent years saw a number of studies utilizing metabolomics technologies to elucidate the biological foundation of the antihypertensive effect of TCM. Metabolomics is a relatively "young" omics approach that has gained enormous attention recently in cardiovascular drug discovery and pharmacology studies of natural products. In this review, we described the use of metabolomics in deciphering TCM diagnostic codes for hypertension and in revealing molecular events that drive the antihypertensive effect. By corroborating the diagnostic rules, there's accumulating evidence showing that metabolic profile could be the signature of different syndromes/patterns of hypertension, which offers new perspectives for disease diagnosis and efficacy optimization. Moreover, TCM treatment significantly altered the metabolic perturbations associated with hypertension, which could be a crucial mechanism of the therapeutic effect of TCM. Not only significantly rebalances the dynamics of metabolic flux, TCM but also elicits metabolic network reorganization through restoring the functions of key metabolites, and metabolic pathways. The role of TCM in regulating metabolic perturbations will be informative to researchers seeking new leads for drug discovery. This review further envisioned the promises of employing metabolomics to explore network pharmacology, host-gut microbiota interactions and metabolic reprogramming in TCM, and possible herb-drug interactions in this field in future.

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.

Different Brain Activation after Acupuncture at Combined Acupoints and Single Acupoint in Hypertension Patients: An Rs-fMRI Study Based on ReHo Analysis

Background

Acupuncture is proved to be effective on hypertension by numerous studies and resting-state functional magnetic resonance imaging (Rs-fMRI) is a widely used technique to study its mechanism. Along with lower blood pressure, patients with hypertension receiving acupuncture also presented improvement in function of cognition, emotion, language, sematic sensation, and so on. This study was a primary study to explore the acting path of acupuncture at combined acupoints in stimulated brain areas related to such functions.

Methods

In this research, regional homogeneity (ReHo) was applied to analyze the Rs-fMRI image data of brain activities after acupuncture at LR3, KI3, and LR3+KI3 and to compare the differences of functional brain activities between stimulating combined acupoints and single acupoint under pathological conditions. A total of thirty hypertension patients underwent Rs-fMRI scanning before acupuncture treatment and then were randomly divided into three groups following random number table, the LR3 group (3 males and 7 females), the KI3 group (3 males and 7 females), and the LR3+ KI3 group (4 males and 6 females) for needling, respectively. When the 30-min treatment finished, they received a further Rs-fMRI scanning. The Rs-fMRI data before and after the acupuncture treatment were analyzed through ReHo.

Results

Compared with preacupuncture, respectively, ReHo values increased in Brodmann areas (BAs) 3, 18, and 40 and decreased in BAs 7 and 31 in LR3+ KI3 group. However, ReHo values only decreased in BA7 of KI3 group while the results showed no significant difference of brain regions in LR3 group between pre- and postacupuncture. Compared with LR3 group, LR3+KI3 group exhibited decreased ReHo values in BAs 7, 9, and 31. Meanwhile, compared with KI3 group, LR3+KI3 group exhibited increased ReHo values in the BAs 2, 18, 30, and 40 and decreased ReHo values in BA13.

Conclusion

Combined acupoints of LR3 and KI3 could act on wider brain areas than the sum of single acupoints, whose functions include emotional processing, cognition, somatic sensation, spatial orientation, language production, and vision.

Exploiting High-Resolution Mass Spectrometry for Targeted Metabolite Quantification and 13C-Labeling Metabolism Analysis

Quantification of targeted metabolites, especially trace metabolites and structural isomers, in complex biological materials is an ongoing challenge for metabolomics. In this chapter, we summarize high-resolution mass spectrometry-based approaches mainly used for targeted metabolite and metabolomics analysis, and then introduce an MS1/MS2-combined PRM workflow for quantification of central carbon metabolism intermediates, amino acids, and shikimate pathway-related metabolites. Major steps in the workflow, including cell culture, metabolite extraction, LC-MS analysis and data processing, are described. Furthermore, we adapt this new approach to a dynamic ¹³C-labeling experiment and demonstrate its unique advantage in capturing and correcting isotopomer labeling curves to facilitate nonstationary ¹³C-labeling metabolism analysis.

Identification of essential hypertension biomarkers in human urine by non-targeted metabolomics based on UPLC-Q-TOF/MS

BACKGROUND

In recent years, using metabolomics technology to study hypertension has made some progress. However, in actual clinical studies, there are few studies on hypertension related metabonomics with human urine as samples. In this study, the urine samples of patients with essential hypertension (EH) were studied by comparing with healthy people to explore the changes of urine metabolites between hypertensive patients and healthy people in order to find potential biomarkers and metabolic pathways.

METHODS

An ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technology was used to analyze the urine metabolites of 75 cases of essential hypertension group (EH) and 75 cases of healthy control group (HC).

RESULTS

According to the PLS-DA pattern recognition analysis, substances with significant differences (P < .05) between the EH group and the HC group were screened out, including 10 potential biomarkers such as L-methionine. The metabolic pathways involved were amino acid metabolism, fatty acid metabolism steroid hormone, biosynthesis and oxidative stress.

CONCLUSION

The non-targeted metabolomics based on UPLC-Q-TOF/MS technology can effectively identify the differential metabolites of potential biomarkers in the urine of essential hypertensive patients and provide a theoretical basis for the treatment of clinical hypertension.

An Overview of Metabolic Phenotyping in Blood Pressure Research

PURPOSE OF THE REVIEW

This review presents the analytical techniques, processing and analytical steps used in metabolomics phenotyping studies, as well as the main results from epidemiological studies on the associations between metabolites and high blood pressure.

RECENT FINDINGS

A variety of metabolomic approaches have been applied to a range of epidemiological studies to uncover the pathophysiology of high blood pressure. Several pathways have been suggested in relation to blood pressure including the possible role of the gut microflora, inflammatory, oxidative stress, and lipid pathways. Metabolic changes have also been identified associated with blood pressure lowering effects of diets high in fruits and vegetables and low in meat intake. However, the current body of literature on metabolic profiling and blood pressure is still in its infancy, not fully consistent and requires careful interpretation. Metabolic phenotyping is a promising approach to uncover metabolic pathways associated with high blood pressure and throw light into the complex pathophysiology of hypertension.

Inhibition of NADPH Oxidase-Dependent Oxidative Stress in the Rostral Ventrolateral Medulla Mediates the Antihypertensive Effects of Acupuncture in Spontaneously Hypertensive Rats

Oxidative stress in the rostral ventrolateral medulla (RVLM), where the sympathetic nervous control center is located, contributes to neural mechanisms of hypertension. Acupuncture was previously reported to favorably affect high blood pressure. However, little is known about the effect of acupuncture on oxidative stress-modulated mechanisms in hypertension. This study was designed to evaluate the hypothesis that acupuncture exerts an antihypertensive effect via ameliorating oxidative stress and the redox-sensitive pathway in the RVLM of spontaneously hypertensive rats. Two weeks of acupuncture reduced blood pressure and sympathetic nervous system activity in spontaneously hypertensive rats. Oxidative stress in the RVLM was alleviated by acupuncture, accompanied by a decrease in nicotinamide adenine dinucleotide phosphate oxidase activity and expression of its subunits. Acupuncture significantly altered the mitogen-activated protein kinases signaling pathway as assessed by pathway enrichment analysis in a gene chip assay. The phosphorylation of p38 mitogen-activated protein kinases and extracellular signal-regulated protein kinase 1/2, but not Jun N-terminal kinase, was downregulated by acupuncture. Microinjection bilaterally of the superoxide dismutase mimetic tempol, nicotinamide adenine dinucleotide phosphate oxidase inhibitor apocynin, or diphenyleneiodonium chloride into the RVLM mimicked the antihypertensive effect of acupuncture. In contrast, the nicotinamide adenine dinucleotide phosphate oxidase agonist tetrabromocinnamic acid abolished the beneficial effects of acupuncture. Furthermore, injection of capsaicin or surgical sectioning of the sciatic nerve abolished the antihypertensive effect of acupuncture. We conclude that acupuncture decreases high blood pressure and nicotinamide adenine dinucleotide phosphate oxidase in the RVLM of spontaneously hypertensive rats. The mitogen-activated protein kinases and the sciatic nerve are involved in the mechanism of acupuncture's amelioration of hypertension.

Data acquisition workflows in liquid chromatography coupled to high resolution mass spectrometry-based metabolomics: Where do we stand?

Typical mass spectrometry (MS) based untargeted metabolomics protocols are tedious as well as time- and sample-consuming. In particular, they often rely on "full-scan-only" analyses using liquid chromatography (LC) coupled to high resolution mass spectrometry (HRMS) from which metabolites of interest are first highlighted, and then tentatively identified by using targeted MS/MS experiments. However, this situation is evolving with the emergence of integrated HRMS based-data acquisition protocols able to perform multi-event acquisitions. Most of these protocols, referring to as data dependent and data independent acquisition (DDA and DIA, respectively), have been initially developed for proteomic applications and have recently demonstrated their applicability to biomedical studies. In this context, the aim of this article is to take stock of the progress made in the field of DDA- and DIA-based protocols, and evaluate their ability to change conventional metabolomic and lipidomic data acquisition workflows, through a review of HRMS instrumentation, DDA and DIA workflows, and also associated informatics tools.