Electroacupuncture Upregulated Ghrelin in Rats with Functional Dyspepsia via AMPK/TSC2/Rheb-Mediated mTOR Inhibition

Bioinformatics and LC-QTOF-MS based discovery of pharmacodynamic and Q-markers of Pitongshu against functional dyspepsia

ETHNOPHARMACOLOGICAL RELEVANCE

Pitongshu (PTS) is a clinically effective empirical formula for the treatment of FD. The efficacy and safety of PTS have been demonstrated in randomized, controlled, double-blind trials, but there is a lack of understanding of the systematic evaluation of the efficacy of PTS and its material basis.

OBJECTIVE

To investigate the efficacy of PTS in Functional dyspepsia (FD) mice and possible Q-markers.

METHOD

In this study, we used "irregular feeding + chronic unpredictable chronic stimulation" to establish a mice model of FD with hepatogastric disharmony. The efficacy of PTS was assessed from hair condition, behavioral, pain, gastrointestinal function, and serum 5-HT, GAS, MTL levels in mice by instillation of different doses of PTS. In addition, the composition of drugs in blood was analyzed by LC-QTOF-MS and potential Q-markers were selected by combining network pharmacology, molecular docking and actual content.

RESULT

Our study showed that different doses of PTS increased pain threshold and writhing latency, decreased the number of writhings, increased gastric emptying rate and small intestinal propulsion rate, decreased total acidity of gastric contents and gastric acid secretion, and increased serum levels of 5-HT, GAS, and MTL in mice to different degrees. Enrichment analysis showed that PTS may be anti-FD through multiple pathways such as Serotonergic synapse, thyroid hormone signaling pathway, cholinergic synapse, and dopaminergic synapse. In addition, potential active ingredient substances were explored by LC-QTOF-MS combined with bioinformatics. Combined with the actual contentselected six constituents, hesperidin, neohesperidin, naringin, paeoniflorin, magnolol and honokiol, possible as Q-markers.

CONCLUSION

PTS may exert its anti-FD effects through multi-component, multi-target and multi-pathway". Constituents, hesperidin, neohesperidin, naringin, paeoniflorin, magnolol and honokiol may be the Q-markers of its anti-FD effects.

Huanglian-banxia promotes gastric motility of diabetic rats by modulating brain-gut neurotransmitters through MAPK signaling pathway

BACKGROUND

Gastric motility disorder is an increasingly common problem among people with diabetes. Neurotransmitters have been recognized as critical regulators in the process of gastric motility. Previous study has shown that herb pair huanglian-banxia (HL-BX) can improve gastric motility, but the underlying mechanism is still unclear. The aim of this study was to further investigate the role of HL-BX in modulating brain-gut neurotransmission to promote gastric motility in diabetic rats, and to explore its possible mechanism.

METHODS

The diabetic rats were divided into five groups. Gastric emptying rate, intestinal propulsion rate, body weight, and average food intake were determined. Substance P (SP), 5- hydroxytryptamine (5-HT), and glucagon-like peptide -1 (GLP-1) in the serum were measured by enzyme-linked immunosorbent assay. Dopamine (DA) and norepinephrine (NE) in the brain were analyzed by high-pressure liquid chromatography with a fluorescence detector. Protein expression of the tissues in the stomach and brain was determined by Western blot.

KEY RESULTS

HL-BX reduced average food intake significantly, increased body weight, and improved gastric emptying rate and intestinal propulsion rate. HL-BX administration caused a significant increase in SP, GLP-1, and 5-HT, but a significant decrease in DA and NE. Interestingly, HL-BX regulated simultaneously the different expressions of MAPK and its downstream p70S6K/S6 signaling pathway in the stomach and brain. Moreover, berberine exhibited a similar effect to HL-BX.

CONCLUSIONS

These results indicated that HL-BX promoted gastric motility by regulating brain-gut neurotransmitters through the MAPK signaling pathway. HL-BX and MAPK provide a potential therapeutic option for the treatment of gastroparesis.

Small G-Protein Rheb Gates Mammalian Target of Rapamycin Signaling to Regulate Morphine Tolerance in Mice

BACKGROUND

Analgesic tolerance due to long-term use of morphine remains a challenge for pain management. Morphine acts on μ-opioid receptors and downstream of the phosphatidylinositol 3-kinase signaling pathway to activate the mammalian target of rapamycin (mTOR) pathway. Rheb is an important regulator of growth and cell-cycle progression in the central nervous system owing to its critical role in the activation of mTOR. The hypothesis was that signaling via the GTP-binding protein Rheb in the dorsal horn of the spinal cord is involved in morphine-induced tolerance.

METHODS

Male and female wild-type C57BL/6J mice or transgenic mice (6 to 8 weeks old) were injected intrathecally with saline or morphine twice daily at 12-h intervals for 5 consecutive days to establish a tolerance model. Analgesia was assessed 60 min later using the tail-flick assay. After 5 days, the spine was harvested for Western blot or immunofluorescence analysis.

RESULTS

Chronic morphine administration resulted in the upregulation of spinal Rheb by 4.27 ± 0.195-fold (P = 0.0036, n = 6), in turn activating mTOR by targeting rapamycin complex 1 (mTORC1). Genetic overexpression of Rheb impaired morphine analgesia, resulting in a tail-flick latency of 4.65 ± 1.10 s (P < 0.0001, n = 7) in Rheb knock-in mice compared to 10 s in control mice (10 ± 0 s). Additionally, Rheb overexpression in spinal excitatory neurons led to mTORC1 signaling overactivation. Genetic knockout of Rheb or inhibition of mTORC1 signaling by rapamycin potentiated morphine-induced tolerance (maximum possible effect, 52.60 ± 9.56% in the morphine + rapamycin group vs. 16.60 ± 8.54% in the morphine group; P < 0.0001). Moreover, activation of endogenous adenosine 5'-monophosphate-activated protein kinase inhibited Rheb upregulation and retarded the development of morphine-dependent tolerance (maximum possible effect, 39.51 ± 7.40% in morphine + metformin group vs. 15.58 ± 5.79% in morphine group; P < 0.0001).

CONCLUSIONS

This study suggests spinal Rheb as a key molecular factor for regulating mammalian target of rapamycin signaling.

EDITOR’S PERSPECTIVE

Acupuncture for brain diseases: Conception, application, and exploration

The brain is probably the most complex organ in the human body. It has been the hot spot and direction of brain science research all over the world to deeply study the pathogenesis of various kinds of brain diseases and find effective treatment methods. Acupuncture is a nonpharmacological therapy of traditional Chinese medicine originating from ancient clinical practice. The research on the treatment of brain diseases by acupuncture has been constantly enriched and updated with the promotion of interdisciplinary research. In order to account for the current achievements in the field of acupuncture for brain diseases, this article reviews it in terms of conception, application, and exploration. Based on the literature review, we found that in the past decades, acupuncture has received widespread attention worldwide and many literatures have reported the clinical efficacy and underlying mechanisms of acupuncture in the treatment of brain diseases. Presently, the conception, application, and exploration of acupuncture in the treatment of brain diseases have evolved from empirical medicine to evidence-based medicine and precision medicine, and are experiencing a deeper understanding of the information about acupuncture regulating the brain function based on interdisciplinary research.

Electroacupuncture restores intestinal mucosal barrier through TLR4/NF-κB p65 pathway in functional dyspepsia-like rats

Functional dyspepsia (FD) is a common functional gastrointestinal disorder with high morbidity. Electroacupuncture (EA) has been applied to treat FD for a long time. The aim of this study was to investigate the effects of EA and its mechanism about intestinal mucosal barrier in rodent model of FD. Male Sprague-Dawley rats were randomly divided into the control group and the model group. Then, the rats in model group were established to the FD model by multifactor interventions. In Experiment 1, qualified FD-like rats were randomly divided into three groups: FD, EA, and acupuncture (AP) groups. The interventions of EA and AP lasted 14 days, food intake, and body weight were recorded every 5 days. In Experiment 2, qualified FD-like rats were randomly divided into five groups: FD, EA, AP, EA + TAK242, and TAK242 groups. The interventions of EA and AP lasted 14 days, while TAK242 injection continued for 6 days. The rats were sacrificed for the measurement of serum Interleukin- 6 (IL-6) and Tumor necrosis factor-α (TNF-α) assayed by ELISA. Western blotting was used to assess the expression of TLR4, Myd88, NF-κB p65, p-NF-κB p65, TRAF6, ZO-1, and occludin in the duodenum. The transmission electron microscope was used to observe the ultrastructure of intestinal epithelial cells. Compared with the rats in the group FD, the rats in EA group had significantly increase of body weight, food intake, and protein expressions of ZO-1 and occludin, while expressions of TLR4, Myd88, NF-κB p65, p-NF-κB p65, TRAF6 in the duodenum and IL-6, and TNF-α in serum were decreased. The EA + TAK242 treatment had similar effects to the EA treatment but with increased potency; compared with EA, AP showed similar but reduced effects. Our data demonstrated that EA is more effective than AP in improving intestine mucosal barrier. The possible mechanisms of EA may involve the TLR4/NF-κB p65 pathway.

Research trends in the field of the gut-brain interaction: Functional dyspepsia in the spotlight – An integrated bibliometric and science mapping approach

Objectives

This study aims to perform a bibliometric analysis of functional dyspepsia (FD), which includes visualizing bibliographic information, in order to identify prevailing study themes, topics of interest, contributing journals, countries, institutions, and authors as well as co-citation patterns.

Methods

The Web of Science™ Core Collection Database was used to retrieve all peer-reviewed scientific publications related to FD research. The validated search terms were entered into the “title” and “author keywords” fields, and the results were sorted by publication year from 2006 to 2022. There were no restrictions on language. On 12 February 2023, a manual export of the complete metadata for each original publication and review article was performed. CiteSpace was used to reveal co-authorship, publication, and co-citation patterns to find prominent authors, organizations, countries, and journals in FD research as well as to identify author keywords with strong citation bursts, which could indicate an emerging research area. VOSviewer was used to build the co-occurrence indicator (co-word) to identify the main author keywords on which previous studies focused and to induce clustered scientific landscape for two consecutive periods to identify intriguing areas for future research.

Results

A search of the database retrieved 2,957 documents. There was a wave-like pattern in the number of publications until 2017, after which there was a spike in publication volume. The USA, China, and Japan provided the majority of contributions. In terms of institution, Mayo Clin, Univ Newcastle, and Katholieke Univ Leuven were found to be the prolific institutions. Additionally, the results indicate that eastern Asian researchers contributed significantly to the global knowledge of literature that led other countries; however, Canada, the USA, Australia, England, and Germany were found to have the highest degree of betweenness centrality. Nicholas J. Talley, Jan Tack, Gerald Holtmann, Michael Camilleri, Ken Haruma, and Paul Moayyedi occupied the top positions based on productivity and centrality indicators. Six thematic clusters emerged (Helicobacter pylori infection; pathophysiological mechanisms of FD; extraintestinal co-morbidities and overlap syndromes associated with FD; herbal medicine in FD; diabetic gastroparesis; and dietary factors in FD). “Acupuncture,” “duodenal eosinophilia,” “gut microbiota,” and others were among the author keywords with rising prevalence.

Conclusion

In FD research, eastern Asian countries have established themselves as major contributors with the highest publishing productivity; however, research has primarily been driven by North America, Europe, and Australia, where cooperation is generally more active and highly influential scientific results are produced. Our analysis suggests that increased investments, training of human resources, improved infrastructures, and expanded collaborations are essential to improving the quality of FD research in Asia. The emerging author keyword analysis suggests that eosinophil-mast cell axis, gut microbiota, mental disorders, and acupuncture are the key areas that attract researchers’ attention as future research boulevards. There is a highly skewed distribution of research output across Asia, with most focus on complementary and alternative medicine (CAM) coming from Chinese, Japanese, and South Korean centers. However, CAM remains an underexplored area of research in the context of FD, and it deserves greater research efforts in order to obtain quality scientific evidence. Furthermore, we propose that the research framework of CAM should not be limited to dysmotility; rather, it could be interpreted within a more holistic context that includes the brain-gut-microbiota axis, as well as novel concepts such as duodenitis, increased mucosal permeability, and infiltration and activation of eosinophils and mast cells, among others. Overall, we provided bibliometrics-based overviews of relevant literature to researchers from different backgrounds and healthcare professionals to provide an in-depth overview of major trends in FD research.

Emerging role of aging in the progression of NAFLD to HCC

With the aging of global population, the incidence of nonalcoholic fatty liver disease (NAFLD) has surged in recent decades. NAFLD is a multifactorial disease that follows a progressive course, ranging from simple fatty liver, nonalcoholic steatohepatitis (NASH) to liver cirrhosis and hepatocellular carcinoma (HCC). It is well established that aging induces pathological changes in liver and potentiates the occurrence and progression of NAFLD, HCC and other age-related liver diseases. Studies of senescent cells also indicate a pivotal engagement in the development of NAFLD via diverse mechanisms. Moreover, nicotinamide adenine dinucleotide (NAD⁺), silence information regulator protein family (sirtuins), and mechanistic target of rapamycin (mTOR) are three vital and broadly studied targets involved in aging process and NAFLD. Nevertheless, the crucial role of these aging-associated factors in aging-related NAFLD remains underestimated. Here, we reviewed the current research on the roles of aging, cellular senescence and three aging-related factors in the evolution of NAFLD to HCC, aiming at inspiring promising therapeutic targets for aging-related NAFLD and its progression.

Research progress of treatment of functional dyspepsia with traditional Chinese medicine compound based on cell signal pathway

Functional dyspepsia (FD) is the most common clinical gastrointestinal disease, with complex and prolonged clinical symptoms. The prevalence of FD is increasing year by year, seriously affecting the quality of life of patients. The main causes of FD are related to abnormal gastrointestinal dynamics, increased visceral sensitivity, Helicobacter pylori (HP) infection, intestinal flora disturbance and psychological factors. A review of the relevant literature reveals that the mechanisms of traditional Chinese medicine (TCM) in the treatment of FD mainly involve the following pathways:5-HT signal pathway, AMPK signal pathway,C-kit signal pathway, CRF signal pathway, PERK signal pathway,NF-κB signal pathway. Based on a holistic concept, TCM promotes gastrointestinal motility, regulates visceral sensitivity and alleviates gastrointestinal inflammation through multiple signal pathways, reflecting the advantages of multi-level, multi-pathway and multi-targeted treatment of FD.

Effects of Electroacupuncture on Gastrointestinal Motility Function, Pain, and Inflammation via Transient Receptor Potential Vanilloid 1 in a Rat Model after Colonic Anastomoses

Background. Complications after colon surgery are a major obstacle to postoperative recovery. The purpose of this study was to investigate the effect of electroacupuncture (EA) at Zusanli (ST36) on gastrointestinal motility in rats after colonic anastomosis and the mechanism of transient receptor potential vanillin 1 (TRPV1) channel in regulating gastrointestinal motility, pain, and inflammation. Methods. The rats were randomly divided into six groups, including the control, model, EA, sham-EA, capsaicin, and capsaicin+EA groups, with preoperative capsaicin pretreatment and EA treatment at ST36 acupoint after surgery. Rats were treated using EA at ST36 or sham acupoints after surgery for 5 days. Capsaicin was intraperitoneally injected into rats 3 hours before surgery. Gastrointestinal motility was assessed by measuring the gastric residue, small intestinal propulsion in vivo, contractile tension, and frequency of isolated muscle strips in vitro. The mechanical withdrawal threshold (MWT) of abdominal incision skin and spontaneous nociceptive scores were observed and recorded in rats after colon anastomosis. The expressions of TRPV1, substance P (SP), neurokinin 1 (NK1) receptor, nuclear factor kappa-B (NF-κB), interleukin- (IL-) 6, L-1β, and tumor necrosis factor- (TNF-) α were determined. Results. Compared with the model group, electroacupuncture at ST36 point could significantly reduce the residual rate of stomach in rats after operation and increase the propulsive force of the small intestine and the contraction tension of the isolated smooth muscle. Electroacupuncture also increased postoperative day 3 MWT values and decreased postoperative spontaneous nociception scores. In addition, electroacupuncture treatment downregulated the expressions of IL-6, IL-1β, TNF-α, TRPV1, NF-κB, SP, and NK1 receptors in the colon tissue of rats after colonic anastomosis. Conclusions. Our study showed that electroacupuncture at ST36 acupoint could improve gastrointestinal motility in rats after colonic anastomosis and relieve intestinal inflammation and pain. The mechanism may be to inhibit the activation of NF-κB and SP/NK1 receptor signaling pathways by inhibiting TRPV1.

Electroacupuncture Promotes Autophagy by Regulating the AKT/mTOR Signaling Pathway in Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) is a complex neurological disease, and its occurrence and development are closely related to the autophagy signaling pathway. However, the mechanism by which electroacupuncture (EA) affects the regulation of autophagy has not been fully elucidated. TLE gene chip dataset GSE27166 and data from rats without epilepsy (n = 6) and rats with epilepsy (n = 6) were downloaded from Gene Expression Omnibus. The differentially expressed genes (DEGs) in the TLE and control groups were identified with the online tool GEO2R. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to analyse the functional and pathway enrichment of genes in the most important modules. A rat model of TLE induced by lithium-pilocarpine treatment was established. EA treatment at DU20 and DU14 in TLE rats was performed for 2 weeks. Neuronal regeneration was determined using immunofluorescence staining. The protein levels of AKT/mTOR signaling pathway and autophagy markers were detected through western blotting and immunohistochemistry. This study identified 1837 DEGs, including 798 upregulated genes and 1039 downregulated genes. GO enrichment and KEGG analyses were performed on DEGs and revealed functional enrichment mainly in the mTOR signaling pathway and autophagy-animal. Furthermore, the number of mature neurons was significantly increased upon coexpressing BrdU/NeuN in TLE rats treated with EA. Western blotting and immunohistochemistry results showed significantly decreased levels of the phosphorylated-AKT and p-mTOR in the hippocampal CA3 and DG regions of TLE rats with EA treatment. And increased p-ULK1/ULK1, LC3-II/LC3-I and p62 levels in TLE rats with EA stimulation. Therefore, this study suggested that EA promoted autophagy in hippocampal neurons during the onset of epilepsy by regulating the AKT/mTOR signaling pathway to treat epilepsy.

[Association between functional dyspepsia and serum levels of brain-gut peptides in children]

OBJECTIVES

To study the association between functional dyspepsia (FD) and serum levels of brain-gut peptides including calcitonin gene-related peptide (CGRP), nesfatin-1, and ghrelin in children.

METHODS

A total of 38 children with FD who attended Shengjing Hospital of China Medical University from November 2019 to December 2020 were enrolled as the FD group. Thirty-four healthy children were enrolled as the control group. Serum samples were collected from all of the children. Enzyme-linked immunosorbent assay was used to measure serum levels of CGRP, ghrelin, and nesfatin-1 for comparison between the two groups. The scores of clinical symptoms were determined for the children with FD. Spearman rank correlation analysis was used to investigate the correlation of symptom scores with the serum levels of brain-gut peptides.

RESULTS

The FD group had significantly higher serum levels of nesfatin-1 and CGRP than the control group (P<0.05), while there was no significant difference in the serum level of ghrelin between the two groups (P>0.05). The serum level of nesfatin-1 was positively correlated with the symptom score of early satiety (r_s=0.553, P<0.001), but was not significantly correlated with the total score of FD (r_s=0.191, P=0.250). The serum level of CGRP was positively correlated with the scores of abdominal pain (r_s=0.479, P=0.002) and belching (r_s=0.619, P<0.001) and the total score of FD (r_s=0.541, P<0.001).

CONCLUSIONS

CGRP and nesfatin-1 may play an important role in the pathophysiological process of FD.

Effects and Components of Herb Pair Huanglian-Banxia on Diabetic Gastroparesis by Network Pharmacology

Diabetic gastroparesis (DGP) is a serious and chronic complication of long-standing diabetes mellitus, which brings a heavy burden to individuals and society. Traditional Chinese medicine (TCM) is considered a complementary and alternative therapy for DGP patients. Huanglian (Coptidis Rhizoma, HL) and Banxia (Pinelliae Rhizoma, BX) combined as herb pair have been frequently used in TCM prescriptions, which can effectively treat DGP in China. In this article, a practical application of TCM network pharmacological approach was used for the research on herb pair HL-BX in the treatment of DGP. Firstly, twenty-seven potential active components of HL-BX were screened from the TCMSP database, and their potential targets were also retrieved. Then, the compound-target network and PPI network were constructed from predicted common targets, and several key targets were found based on the degree of the network. Next, GO and KEGG enrichment analyses were conducted to obtain several significantly enriched terms. Finally, the experimental verification was made. The results demonstrated that network pharmacological approach was a powerful means for identifying bioactive ingredients and mechanisms of action for TCM. Network pharmacology provided an effective strategy for TCM modern research.

Autophagy and Digestive Disorders: Advances in Understanding and Therapeutic Approaches

The gastrointestinal (GI) tract is a series of hollow organs that is responsible for the digestion and absorption of ingested foods and the excretion of waste. Any changes in the GI tract can lead to GI disorders. GI disorders are highly prevalent in the population and account for substantial morbidity, mortality, and healthcare utilization. GI disorders can be functional, or organic with structural changes. Functional GI disorders include functional dyspepsia and irritable bowel syndrome. Organic GI disorders include inflammation of the GI tract due to chronic infection, drugs, trauma, and other causes. Recent studies have highlighted a new explanatory mechanism for GI disorders. It has been suggested that autophagy, an intracellular homeostatic mechanism, also plays an important role in the pathogenesis of GI disorders. Autophagy has three primary forms: macroautophagy, microautophagy, and chaperone-mediated autophagy. It may affect intestinal homeostasis, host defense against intestinal pathogens, regulation of the gut microbiota, and innate and adaptive immunity. Drugs targeting autophagy could, therefore, have therapeutic potential for treating GI disorders. In this review, we provide an overview of current understanding regarding the evidence for autophagy in GI diseases and updates on potential treatments, including drugs and complementary and alternative medicines.

Energy deficiency caused by CTPS downregulation in decidua may contribute to pre-eclampsia by impairing decidualization

Pre-eclampsia (PE) is a pregnancy-related disorder that occurs after 20 weeks of gestation. It seriously affects the health of maternity and the fetus. However, the pathogenesis of PE is still unknown. Decidualization deficiency is considered a contributing factor to the development of PE. CTP synthetase (CTPS) which is the rate-limiting enzyme in the CTP de novo biosynthesis, is essential for nucleic acid synthesis and cellular energy metabolism, and often appears as cytoophidium in many cell types. Here, we found that the expression of CTPS was significantly downregulated in decidual tissues of patients with severe PE compared with healthy pregnant women. During in vitro decidualization, changes in CTPS were accompanied by opposite fluctuation of the AMPK signaling pathway. Moreover, the downregulation of CTPS by glutamine analogs or CTPS small interfering RNA inhibited the decidualization process and the AMPK signaling pathway. Investigating the underlying mechanism of action by co-immunoprecipitation coupled with mass spectrometry showed that CTPS interacted with ATP synthase (ATPS) and maintained the content of ATP on Day 3 of decidualization. However, when combined with mitochondrial stress protein STRESS-70 instead of ATPS, the concentration of ATP on Day 6 of induction was reduced. Corresponding to this, CTPS was mainly distributes in the cytoplasm on Day 3 of induction, while it appeared both in the cytoplasm and the nucleus on Day 6 in decidualized cells, which was similar to that in cells before induction. In summary, we believe that CTPS plays an important role in decidualization by participating in energy metabolism. Abnormal expression of CTPS in decidualization would lead to abnormal decidualization and consequently result in the occurrence of PE.