Electroacupuncture with high frequency at acupoint ST-36 induces regeneration of lost enteric neurons in diabetic rats via GDNF and PI3K/AKT signal pathway

The PI3K/Akt signaling axis and type 2 diabetes mellitus (T2DM): From mechanistic insights into possible therapeutic targets

Type 2 diabetes mellitus (T2DM) is an immensely debilitating chronic disease that progressively undermines the well-being of various bodily organs and, indeed, most patients succumb to the disease due to post-T2DM complications. Although there is evidence supporting the activation of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway by insulin, which is essential in regulating glucose metabolism and insulin resistance, the significance of this pathway in T2DM has only been explored in a few studies. The current review aims to unravel the mechanisms by which different classes of PI3Ks control the metabolism of glucose; and also to discuss the original data obtained from international research laboratories on this topic. We also summarized the role of the PI3K/Akt signaling axis in target tissues spanning from the skeletal muscle to the adipose tissue and liver. Furthermore, inquiries regarding the impact of disrupting this axis on insulin function and the development of insulin resistance have been addressed. We also provide a general overview of the association of impaired PI3K/Akt signaling pathways in the pathogenesis of the most prevalent diabetes-related complications. The last section provides a special focus on the therapeutic potential of this axis by outlining the latest advances in active compounds that alleviate diabetes via modulation of the PI3K/Akt pathway. Finally, we comment on the future research aspects in which the field of T2DM therapies using PI3K modulators might be developed.

Electroacupuncture improves gastrointestinal motility through a central-cholinergic pathway-mediated GDNF releasing from intestinal glial cells to protect intestinal neurons in Parkinson's disease rats

Constipation symptoms of Parkinson's disease (PD) seriously reduce the quality of life of patients and aggravate the development of the disease, but current treatment options still cannot alleviate the progress of constipation. Electroacupuncture (EA) is a new method for the treatment of constipation, which can effectively treat the symptoms of constipation in PD patients. However, the specific regulatory mechanisms of EA in the treatment of constipation symptoms in PD remain unclear. The aim of this study is to investigate the therapeutic effect of EA on PD constipation rats and its regulatory mechanism. A rotenone (ROT)-induced gastrointestinal motility disorder model was used to simulate the pathological process of constipation in PD. The results showed that EA could effectively promote gastrointestinal peristalsis, reduce α-synuclein accumulation in substantia nigra and colon and colonic injury in rats after ROT administration. Mechanistically, EA activation of the central-cholinergic pathway increases acetylcholine release in the colon. At the same time, EA up-regulated the co-expression of enteric glial cells (EGCs) and α7 nicotinic acetylcholine receptor (α7nAChR). EA increased the expression of choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), and tyrosine hydroxylase (TH) in the colon of PD rats. Further mechanistic studies showed that EA increased the expression of glial cell-derived neurotrophic factor (GDNF), GFRa1 and p-AKT in colon tissues. The present study confirmed that EA upregulates α7nAChR through a central-cholinergic mechanism to promote GDNF release from EGCs, thereby protecting intestinal neurons and thereby improving gastrointestinal motility.

VGLUT2 and APP family: unraveling the neurobiochemical mechanisms of neurostimulation therapy to STZ-induced diabetes and neuropathy

Diabetic Peripheral Neuropathy (DPN) poses an escalating threat to public health, profoundly impacting well-being and quality of life. Despite its rising prevalence, the pathogenesis of DPN remains enigmatic, and existing clinical interventions fall short of achieving meaningful reversals of the condition. Notably, neurostimulation techniques have shown promising efficacy in alleviating DPN symptoms, underscoring the imperative to elucidate the neurobiochemical mechanisms underlying DPN. This study employs an integrated multi-omics approach to explore DPN and its response to neurostimulation therapy. Our investigation unveiled a distinctive pattern of vesicular glutamate transporter 2 (VGLUT2) expression in DPN, rigorously confirmed through qPCR and Western blot analyses in DPN C57 mouse model induced by intraperitoneal Streptozotocin (STZ) injection. Additionally, combining microarray and qPCR methodologies, we revealed and substantiated variations in the expression of the Amyloid Precursor Protein (APP) family in STZ-induced DPN mice. Analyzing the transcriptomic dataset generated from neurostimulation therapy for DPN, we intricately explored the differential expression patterns of VGLUT2 and APPs. Through correlation analysis, protein-protein interaction predictions, and functional enrichment analyses, we predicted the key biological processes involving VGLUT2 and the APP family in the pathogenesis of DPN and during neurostimulation therapy. This comprehensive study not only advances our understanding of the pathogenesis of DPN but also provides a theoretical foundation for innovative strategies in neurostimulation therapy for DPN. The integration of multi-omics data facilitates a holistic view of the molecular intricacies of DPN, paving the way for more targeted and effective therapeutic interventions.

Chronic Electroacupuncture With High-Frequency at ST-36 Promotes Gastrointestinal Motility by Regulating Bone Morphogenetic Protein 2 Secretion of Muscularis Macrophages

BACKGROUND

Electroacupuncture (EA) at Zusanli (ST36) is an alternative treatment for several gastrointestinal motility disorders; however, the exact mechanism is unconfirmed. We aimed to show the potential effects of EA on muscularis macrophages (MMφ), the bone morphogenetic protein (BMP)/BMP receptor (BMPR)-Smad signal pathway, and enteric neurons in diabetic mice. This may provide fresh insight into ways EA affects gastrointestinal motility.

MATERIALS AND METHODS

C57BL/6J healthy adult male mice were randomly divided into five groups: regular control group, diabetes group, diabetes with sham EA group (acupuncture only), diabetes with low-frequency EA group (10 Hz), diabetes with high-frequency EA group (HEA) (100 Hz). The stimulation lasted eight weeks. Gastrointestinal motility was assessed. We identified M2-like MMφ in the layer of colonic muscle by flow cytometry. Western Blot, real-time polymerase chain reaction, and immunofluorescent staining were also used to determine the MMφ, molecules in the BMP2/BMPR-Smad pathway, and PGP9.5, neuronal nitric oxide synthase (nNOS) expression of enteric neurons in the colon of each group.

RESULTS

1) HEA improved the gastrointestinal motility (gastrointestinal transit time, defecation frequency) of diabetic mice. 2) HEA reversed the decreased proportion of M2-like MMφ and expression of the CD206 in the colon of diabetic mice. 3) HEA restored the downregulations of BMP2, BMPR1b, and Smad1 in the BMP2/BMPR-Smad pathway and increased downstream enteric neurons marked by PGP9.5, nNOS in the colon of diabetes mice.

CONCLUSIONS

HEA might promote gut dynamics by upregulating M2-like MMφ in the colon of diabetic mice, which in turn leads to the accumulation of molecules in the BMP2/BMPR-Smad signaling pathway and downstream enteric neurons.

Noninvasive electrical neuromodulation for gastrointestinal motility disorders

INTRODUCTION

Gastrointestinal motility disorders are highly prevalent without satisfactory treatment. noninvasive electrical neuromodulation is an emerging therapy for treating various gastrointestinal motility disorders.

AREAS COVERED

In this review, several emerging noninvasive neuromodulation methods are introduced, including transcutaneous auricular vagal nerve stimulation, percutaneous auricular vagal nerve stimulation, transcutaneous cervical vagal nerve stimulation, transcutaneous electrical acustimulation, transabdominal interference stimulation, tibial nerve stimulation, and translumbosacral neuromodulation therapy. Their clinical applications in the most common gastrointestinal motility are discussed, including gastroesophageal reflux disease, functional dyspepsia, gastroparesis, functional constipation, irritable bowel syndrome, and fecal incontinence. PubMed database was searched from 1995 to June 2023 for relevant articles in English.

EXPERT OPINION

Noninvasive neuromodulation is effective and safe in improving both gastrointestinal symptoms and dysmotility; it can be used when pharmacotherapy is ineffective. Future directions include refining the methodology, improving device development and understanding mechanisms of action.

Application and underlying mechanism of acupuncture for the nerve repair after peripheral nerve injury: remodeling of nerve system

Peripheral nerve injury (PNI) is a structural event with harmful consequences worldwide. Due to the limited intrinsic regenerative capacity of the peripheral nerve in adults, neural restoration after PNI is difficult. Neurological remodeling has a crucial effect on the repair of the form and function during the regeneration of the peripheral nerve after the peripheral nerve is injured. Several studies have demonstrated that acupuncture is effective for PNI-induced neurologic deficits, and the potential mechanisms responsible for its effects involve the nervous system remodeling in the process of nerve repair. Moreover, acupuncture promotes neural regeneration and axon sprouting by activating related neurotrophins retrograde transport, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), N-cadherin, and MicroRNAs. Peripheral nerve injury enhances the perceptual response of the central nervous system to pain, causing central sensitization and accelerating neuronal cell apoptosis. Together with this, the remodeling of synaptic transmission function would worsen pain discomfort. Neuroimaging studies have shown remodeling changes in both gray and white matter after peripheral nerve injury. Acupuncture not only reverses the poor remodeling of the nervous system but also stimulates the release of neurotrophic substances such as nerve growth factors in the nervous system to ameliorate pain and promote the regeneration and repair of nerve fibers. In conclusion, the neurological remodeling at the peripheral and central levels in the process of acupuncture treatment accelerates nerve regeneration and repair. These findings provide novel insights enabling the clinical application of acupuncture in the treatment of PNI.

Novel insights into the nervous system affected by prolonged hyperglycemia

Multiple molecular pathways including the receptor for advanced glycation end-products-diaphanous related formin 1 (RAGE-Diaph1) signaling are known to play a role in diabetic peripheral neuropathy (DPN). Evidence suggests that neuropathological alterations in type 1 diabetic spinal cord may occur at the same time as or following peripheral nerve abnormalities. We demonstrated that DPN was associated with perturbations of RAGE-Diaph1 signaling pathway in peripheral nerve accompanied by widespread spinal cord molecular changes. More than 500 differentially expressed genes (DEGs) belonging to multiple functional pathways were identified in diabetic spinal cord and of those the most enriched was RAGE-Diaph1 related PI3K-Akt pathway. Only seven of spinal cord DEGs overlapped with DEGs from type 1 diabetic sciatic nerve and only a single gene cathepsin E (CTSE) was common for both type 1 and type 2 diabetic mice. In silico analysis suggests that molecular changes in spinal cord may act synergistically with RAGE-Diaph1 signaling axis in the peripheral nerve. KEY MESSAGES: Molecular perturbations in spinal cord may be involved in the progression of diabetic peripheral neuropathy. Diabetic peripheral neuropathy was associated with perturbations of RAGE-Diaph1 signaling pathway in peripheral nerve accompanied by widespread spinal cord molecular changes. In silico analysis revealed that PI3K-Akt signaling axis related to RAGE-Diaph1 was the most enriched biological pathway in diabetic spinal cord. Cathepsin E may be the target molecular hub for intervention against diabetic peripheral neuropathy.

Effects of Electroacupuncture for Opioid-Induced Constipation in Patients With Cancer in China: A Randomized Clinical Trial

IMPORTANCE

Opioid-induced constipation (OIC) is prevalent among patients treated with opioids for cancer pain. Safe and effective therapies for OIC in patients with cancer remain an unmet need.

OBJECTIVE

To determine the efficacy of electroacupuncture (EA) for OIC in patients with cancer.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted at 6 tertiary hospitals in China among 100 adult patients with cancer who were screened for OIC and enrolled between May 1, 2019, and December 11, 2021.

INTERVENTIONS

Patients were randomized to receive 24 sessions of EA or sham electroacupuncture (SA) over 8 weeks and then were followed up for 8 weeks after treatment.

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of overall responders, defined as patients who had at least 3 spontaneous bowel movements (SBMs) per week and an increase of at least 1 SBM from baseline in the same week for at least 6 of the 8 weeks of the treatment period. All statistical analyses were based on the intention-to-treat principle.

RESULTS

A total of 100 patients (mean [SD] age, 64.4 [10.5] years; 56 men [56.0%]) underwent randomization; 50 were randomly assigned to each group. Among them, 44 of 50 patients (88.0%) in the EA group and 42 of 50 patients (84.0%) in the SA group received at least 20 (≥83.3%) sessions of treatment. The proportion of overall responders at week 8 was 40.1% (95% CI, 26.1%-54.1%) in the EA group and 9.0% (95% CI, 0.5%-17.4%) in the SA group (difference between groups, 31.1 percentage points [95% CI, 14.8-47.6 percentage points]; P < .001). Compared with SA, EA provided greater relief for most OIC symptoms and improved quality of life among patients with OIC. Electroacupuncture had no effects on cancer pain and its opioid treatment dosage. Electroacupuncture-related adverse events were rare, and, if any, all were mild and transient.

CONCLUSIONS AND RELEVANCE

This randomized clinical trial found that 8-week EA treatment could increase weekly SBMs with a good safety profile and improve quality of life for the treatment of OIC. Electroacupuncture thus provided an alternative option for OIC in adult patients with cancer.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03797586.

Combined acupuncture and moxibustion therapy for the treatment of neurogenic bladder and bowel dysfunction following traumatic spinal cord injury: A case report

Neurogenic bladder and bowel are two critical autonomic complications following traumatic spinal cord injury (TSCI). Chronic lower urinary tract and bowel dysfunctions can lead to secondary complications, drastically affect the quality of life and significantly increase the risk of hospital readmission and mortality. Other than symptomatic treatments, a few effective therapies are available. Combined acupuncture and moxibustion therapy has positive effects on improving nerve repair and functional recovery in the early phases following TSCI. However, whether it is effective for TSCI-related chronic urinary and bowel dysfunctions remains unknown. This report presents the case of a 26-year-old male patient who experienced neurogenic bladder and bowel dysfunction following TSCI due to an accidental fall from height for more than 10 months and visited our department for combined acupuncture and moxibustion therapy. After 48 treatment sessions, he regained voluntary urination and defecation to a large extent. Urodynamic testing showed recovered bladder compliance and improved detrusor contractility. Symptom assessment with the Qualiveen Short-Form and neurogenic bowel dysfunction scores demonstrated reduced symptom severity. This case suggests that combined acupuncture and moxibustion therapy might help to restore the physiological functions of the lower urinary and digestive tracts following TSCI and might be a promising alternative for the treatment of neurogenic bladder and bowel dysfunction in patients with TSCI.

Electroacupuncture at Acupoint ST36 (Zusanli) Improves Intestinal Motility Dysfunction Via Increasing the Proportion of Cholinergic Neurons in Rat Ileal Myenteric Ganglia after Severe Acute Pancreatitis

Using a severe acute pancreatitis (SAP) rat model, the mechanism of electroacupuncture (EA) were studied on the intestinal function of pancreatitis. The SAP models were established by injecting 30% L-ornithine at hourly intervals, and were divided into two groups (14 in each): SAP model group, which was not treated, and EA group, which received EA at ST36 at a frequency of 1-2 Hz and amplitude of 1 mA for 30 min twice a day. Fourteen rats were also included as the control group. After EA, the intestinal propulsion was measured. In the distal ileum myenteric plexus, the density of HuC/D and the proportion of cholinergic neurons were measured using immunohistochemistry. Compared to the SAP model group, the EA group demonstrated significant improvements in intestinal propulsion rates. Furthermore, after EA, the density of myenteric neurons in the ileum returned to normal levels and the proportion of cholinergic neurons was increased compared to the SAP model group. And finally, EA alleviated the damage to the pancreas. Thus, our results suggest that EA stimulation at ST36 can partly restore the enteric neuron function and improve intestinal motility dysfunction, therefore could ameliorate SAP. The enteric nervous system can participate in changes in intestinal motility by affecting cholinergic neurons.

Transcutaneous Electrical Acustimulation Improves Irritable Bowel Syndrome With Constipation by Accelerating Colon Transit and Reducing Rectal Sensation Using Autonomic Mechanisms

INTRODUCTION

Slow colon transit and visceral hypersensitivity are recognized as major pathophysiological mechanisms in irritable bowel syndrome with constipation (IBS-C). However, there is a lack of therapies targeting both abdominal pain and colonic motility. This study was designed to investigate the long-term effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) in patients with IBS-C.

METHODS

Fifty-two patients with IBS-C were randomized into 2 groups: daily TEA for 4 weeks (n = 26) and daily sham-TEA for 4 weeks (n = 26). The number of complete spontaneous bowel movements per week (CSBMs/week, primary outcome), Irritable Bowel Syndrome Severity Scoring System, Patient Assessment of Constipation Quality of Life, visual analog scale (VAS) pain score, colonic transit time, and anorectal physiology were evaluated before treatment and at the end of the treatment. Colonic transit was assessed with radiopaque markers. Electrocardiograms were recorded for assessing autonomic functions.

RESULTS

(i) TEA improved constipation and abdominal pain. After the treatment, the number of CSBMs/week during the last week in the TEA group was higher than that in the sham-TEA group (3.5 ± 1.6 vs 2.3 ± 0.6, P = 0.002). Similar effects were also noted in the visual analog scale pain score ( P = 0.002) and Irritable Bowel Syndrome Severity Scoring System score ( P = 0.025). In addition, there was a significant improvement in the quality of life of patients with constipation. The Patient Assessment of Constipation Quality of Life total score was significantly decreased in the TEA group ( P = 0.004). (ii) Compared with sham-TEA, TEA improved colon transit ( P = 0.002) and increased the threshold of rectal sensation (desire to defecate, P = 0.004; maximum tolerability, P &lt; 0.001). (iii) TEA increased vagal activity, compared with sham-TEA ( P &lt; 0.05); at the end of the treatment, the vagal activity was significantly correlated with colon transit and the CSBMs/week.

DISCUSSION

TEA improves constipation and symptoms of IBS by accelerating colon transit and reducing rectal sensation, possibly mediated by using the autonomic mechanisms.

Glutamate regulates gliosis of BMSCs to promote ENS regeneration through α-KG and H3K9/H3K27 demethylation

Background

There is a lack of effective therapies for enteric nervous system (ENS) injury. Our previous study showed that transplanted bone marrow-derived mesenchymal stem cells (BMSCs) play a “glia-like cells” role in initiating ENS regeneration in denervated mice. Cellular energy metabolism is an important factor in maintaining the biological characteristics of stem cells. However, how cellular energy metabolism regulates the fate of BMSCs in the ENS-injured microenvironment is unclear.

Methods

The biological characteristics, energy metabolism, and histone methylation levels of BMSCs following ENS injury were determined. Then, glutamate dehydrogenase 1 (Glud1) which catalyzes the oxidative deamination of glutamate to α-KG was overexpressed (OE) in BMSCs. Further, OE-Glud1 BMSCs were targeted–transplanted into the ENS injury site of denervated mice to determine their effects on ENS regeneration.

Results

In vitro, in the ENS-injured high-glutamate microenvironment, the ratio of α-ketoglutarate (α-KG) to succinate (P < 0.05), the histone demethylation level (P < 0.05), the protein expression of glial cell markers (P < 0.05), and the gene expression of Glud1 (P < 0.05) were significantly increased. And the binding of H3K9me3 to the GFAP, S100B, and GDNF promoter was enhanced (P < 0.05). Moreover, α-KG treatment increased the monomethylation and decreased the trimethylation on H3K9 (P < 0.01) and H3K27 (P < 0.05) in BMSCs and significantly upregulated the protein expression of glial cell markers (P < 0.01), which was reversed by the α-KG competitive inhibitor D-2-hydroxyglutarate (P < 0.05). Besides, overexpression of Glud1 in BMSCs exhibited increases in monomethylation and decreases in trimethylation on H3K9 (P < 0.05) and H3K27 (P < 0.05), and upregulated protein expression of glial cell markers (P < 0.01). In vivo, BMSCs overexpressing Glud1 had a strong promotion effect on ENS regeneration in denervated mice through H3K9/H3K27 demethylation (P < 0.05), and upregulating the expression of glial cell protein (P < 0.05).

Conclusions

BMSCs overexpressing Glud1 promote the expression of glial cell markers and ENS remodeling in denervated mice through regulating intracellular α-KG and H3K9/H3K27 demethylation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02936-7.

CD44 fucosylation on bone marrow-derived mesenchymal stem cells enhances homing and promotes enteric nervous system remodeling in diabetic mice

Background

Diabetes can cause extensive enteric nervous system (ENS) injuries and gastrointestinal motility disorder. In developing possible treatments, researchers have engaged in tissue regeneration engineering with the very promising bone marrow-derived mesenchymal stem cells (BMSCs). However, BMSCs have poor homing ability to the targeted tissues after intravenous injection. Thus, we aimed to investigate whether enhancing the expression of E-selectin ligand on BMSCs could improve their homing ability and subsequently influence their role in ENS remodeling in diabetic mice.

Methods

First, we constructed the fucosylation modification of CD44 on BMSCs through a fucosyltransferase VII (FTVII) system to generate a Hematopoietic Cell E-/L-selectin Ligand (HCELL) property, a fucosylated sialyllactosaminyl glycovariant of CD44 that potently binds E-selectin. Next, FTVII-modified and unmodified BMSCs labeled with green fluorescent protein (GFP) were injected into diabetic mice through the tail vein to compare their homing ability to the gastrointestinal tract and their effect on ENS remodeling, respectively. A bioluminescent imaging system was used to evaluate the homing ability of GFP-labeled BMSCs with and without FTVII modification, to the gastrointestinal tract. Gastrointestinal motility was assessed by gastrointestinal transient time, defecation frequency, stool water content and colon strips contractility. Immunofluorescence staining and western blotting were used to assess the expression levels of protein gene product 9.5 (PGP9.5), glial fibrillary acidic protein (GFAP) and glial cell line-derived neurotrophic factor (GDNF).

Results

The FTVII-mediated α(1,3)-fucosylation modification of CD44 on BMSCs generated a HCELL property. Bioluminescent imaging assays showed that FTVII-modified BMSCs had enhanced homing ability to gastrointestinal tract, mainly to the colon, 24 h after injection through the tail vein. Compared with diabetic mice, FTVII-modified BMSCs significantly promoted the gastrointestinal motility and the ENS remodeling, including intestinal peristalsis (P < 0.05), increased feces excretion (P < 0.05) and the water content of the feces (P < 0.05), restored the spontaneous contraction of the colon (P < 0.05), and upregulated the protein expression levels of PGP9.5 (P < 0.01), GFAP (P < 0.001), and GDNF (P < 0.05), while unmodified BMSCs did not (P > 0.05).

Conclusions

CD44 fucosylation modification on murine BMSCs promotes homing ability to the gastrointestinal tract and ENS remodeling in diabetic mice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00632-2.

Electroacupuncture at ST36 Improve the Gastric Motility by Affecting Neurotransmitters in the Enteric Nervous System in Type 2 Diabetic Rats

Electroacupuncture (EA) can effectively relieve hyperglycemia and gastric emptying disorders in diabetic gastroparesis (DGP). However, the effect of EA on type 2 diabetes mellitus (T2DM) gastroparesis and its mechanism in the enteric nervous system (ENS) are rarely studied. We investigated the therapeutic effect of EA at ST36 and its effect on the main inhibitory and excitatory neurotransmitters in the ENS in DGP rats. Male Sprague-Dawley (SD) rats were fed a high-fat diet for 2 weeks and injected with streptozotocin (STZ) at 35 mg/kg to induce T2DM. T2DM rats were divided into the diabetic mellitus (DM) group and the EA group. The control (CON) group comprised normal rats without any intervention. EA treatment was started 6 weeks after the induction of DM and continued for 5 weeks. The body weight and food intake of the rats were recorded every week. Blood glucose, insulin, glucose tolerance, gastric emptying, and antral motility were measured after treatment. The expression of protein gene product 9.5 (PGP9.5), neuronal nitric oxide synthase (nNOS), and choline acetyltransferase (ChAT) in gastric antrum were quantified by western blotting and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The T2DM gastroparesis model was successfully established. EA treatment reduced the body weight, food intake, and blood glucose; improved glucose intolerance and insulin resistance; increased the gastric emptying rate, the mean antral pressure, and the amplitude of antral motility; and decreased the frequency of antral motility compared with those in the DM group. EA treatment increased the expression level of nNOS, ChAT, and PGP9.5 proteins, and nNOS and ChAT mRNA. The results suggested that EA at ST36 could ameliorate DGP, partly restore the damage to general neurons, and increase nNOS and ChAT in the gastric antrum. EA improved DGP partly via reducing the loss of inhibitory and excitatory neurotransmitters in the ENS.

Electroacupuncture vs Prucalopride for Severe Chronic Constipation: A Multicenter, Randomized, Controlled, Noninferiority Trial

INTRODUCTION

This multicenter, randomized, noninferiority trial compared electroacupuncture with prucalopride for the treatment of severe chronic constipation (SCC).

METHODS

Participants with SCC (≤ 2 mean weekly complete spontaneous bowel movements [CSBMs]) were randomly assigned to receive either 28-session electroacupuncture over 8 weeks with follow-up without treatment over 24 weeks or prucalopride (2 mg/d before breakfast) over 32 weeks. The primary outcome was the proportion of participants with ≥3 mean weekly CSBMs over weeks 3-8, based on the modified intention-to-treat population, with -10% as the noninferior margin.

RESULTS

Five hundred sixty participants were randomized, 280 in each group. Electroacupuncture was noninferior to prucalopride for the primary outcome (36.2% vs 37.8%, with a difference of -1.6% [95% confidence interval, -8% to 4.7%], P < 0.001 for noninferiority); almost the same results were found in the per-protocol population. The proportions of overall CSBM responders through weeks 1-8 were similar in the electroacupuncture and prucalopride groups (24.91% vs 25.54%, with a difference of -0.63% [95% confidence interval, -7.86% to 6.60%, P = 0.864]). Except during the first 2-week treatment, no between-group differences were found in outcomes of excessive straining, stool consistency, and quality of life. Adverse events occurred in 49 (17.69%) participants in the electroacupuncture group and 123 (44.24%) in the prucalopride group. One non-treatment-related serious adverse event was recorded in the electroacupuncture group.

DISCUSSION

Electroacupuncture was noninferior to prucalopride in relieving SCC with a good safety profile. The effects of 8-week electroacupuncture could sustain for 24 weeks after treatment. Electroacupuncture is a promising noninferior alternative for SCC (see Visual Abstract, http://links.lww.com/AJG/B776).

An Apriori Algorithm-Based Association Rule Analysis to Identify Acupoint Combinations for Treating Diabetic Gastroparesis

We explored the potential association rules within acupoints in treating diabetic gastroparesis (DGP) using Apriori algorithm complemented with another partition-based algorithm, a frequent pattern growth algorithm. Apriori algorithm is a data mining-based analysis that is widely applied in various fields, such as business and medicine, to mine frequent patterns in datasets. To search for effective acupoint combinations in the treatment of DGP, we implemented Apriori algorithm to investigate the association rules of acupoints among 17 randomized controlled trials (RCTs). The acupoints were extracted from the 17 included RCTs. In total, 29 distinct acupoints were observed in the RCTs. The top 10 frequently selected acupoints were CV12, ST36, PC6, ST25, BL21, BL20, BL23, SP6, BL18, and ST21. The frequency pattern of acupoints achieved by using a frequent pattern growth algorithm also confirms the result. The results showed that the most associated rules were {BL23, BL18} ≥ {SP6}, {BL20, BL18} ≥ {PC6}, {PC6, BL18} ≥ {BL20}, and {SP6, BL18} ≥ {BL23} in the database. Acupoints, including BL23, BL18, SP6, BL20, and PC6, can be deemed as core elements of acupoint combinations for treating DGP.

Electroacupuncture at Zusanli (ST36) Repairs Interstitial Cells of Cajal and Upregulates c-Kit Expression in Rats with SCI-Induced Neurogenic Bowel Dysfunction

Background

Electroacupuncture (EA) could improve colonic transit activity in rats with neurogenic bowel dysfunction (NBD) caused by spinal cord injury (SCI). The function of interstitial cells of Cajal (ICCs) and c-Kit expression may play essential roles in this process. Material and Methods. Thirty-six Sprague Dawley rats were randomized to the sham group, the SCI group, or the SCI + EA group (bilateral Zusanli, 30 min/day, 14 days). Changes in the ultrastructural morphology of ICCs were observed. The c-Kit expression on different levels was analyzed by immunohistochemistry, Western blotting, and RT-qPCR, respectively.

Results

Abnormal morphology of ICCs and downregulation of the c-Kit expression occurred after SCI. While the number of ICCs was increased, the ultrastructural morphology was improved significantly in EA rats. They also showed better improvement in c-Kit expression at both protein and gene levels.

Conclusion

Abnormal ICCs in colon tissues and the downregulated expression of c-Kit could be observed after SCI. EA at Zusanli (ST36) could improve the colon function by repairing the morphology and increasing the number of ICCs and upregulating c-Kit expression.

Neuromechanism of acupuncture regulating gastrointestinal motility

Acupuncture has been used in China for thousands of years and has become more widely accepted by doctors and patients around the world. A large number of clinical studies and animal experiments have confirmed that acupuncture has a benign adjustment effect on gastrointestinal (GI) movement; however, the mechanism of this effect is unclear, especially in terms of neural mechanisms, and there are still many areas that require further exploration. This article reviews the recent data on the neural mechanism of acupuncture on GI movements. We summarize the neural mechanism of acupuncture on GI movement from four aspects: acupuncture signal transmission, the sympathetic and parasympathetic nervous system, the enteric nervous system, and the central nervous system.

GDNFOS1 knockdown decreases the invasion and viability of glioblastoma cells

Glioblastoma multiforme is the most aggressive primary brain cancer in adults. Therefore, it is important to investigate the mechanisms associated with cell viability and invasion ability of the cells in glioblastoma multiforme. The opposite strand of the glial cell line-derived neurotrophic factor (GDNF) gene is used to transcribe the cis-antisense GDNF opposite strand (GDNFOS) gene, which belongs to the long noncoding RNAs. The current study assessed the effects of GDNFOS1 overexpression and interference on GDNF expression, cell viability and invasion ability in U87 and U251 MG glioblastoma cells. Overexpression and interference were performed using constructed lentiviral vectors, including long non-coding RNA GDNFOS1 overexpression vector, pL-short hairpin RNA (shRNA)-GDNFOS1-9, pL-shRNA-GDNFOS1-49, pL-shRNA-GDNFOS1-248, pL-shRNA-GDNFOS1-9+49, pL-shRNA-GDNFOS1-9+248 and pL-shRNA-GDNFOS1-49+248. Reverse transcription-quantitative PCR was used to determine the efficiency of interference and overexpression of GDNFOS1 in U87 and U251 MG cells. GDNF protein expression in U87 and U251 MG cells was detected using western blot analysis. In addition, cell viability was detected using a cell counting kit-8 assay at 24, 48 and 72 h after GDNFOS1 overexpression or interference. A transwell invasion assay was used to detect invasion ability. Different shRNA sequences were tested and the results revealed that a combination (pL-shRNA-GDNFOS1-49+248) was most effective in the knock-down GDNFOS1. Compared with the control group, GDNF expression in U87 MG cells was significantly increased in the GDNFOS1 overexpression group and decreased in the shRNA-GDNFOS1-248 group. U87 MG cell viability was significantly increased in the GDNFOS1 overexpression group at 24, 48 and 72 h compared with the negative control group. The viability of U87 MG cells was decreased in the GDNFOS1 interference group at 72 h when compared with the control group. The relative invasive ability was significantly increased in the GDNFOS1 overexpression group when compared with the negative control group. The invasive ability was significantly decreased in the GDNFOS1 interference group when compared with the negative control group. Similar results were exhibited by the U251 MG cells. Overall, GDNF expression, cell viability and invasion ability of glioblastoma cells significantly increased with GDNFOS1 overexpression and decreased with GDNFOS1 interference.

Electroacupuncture via chronically implanted electrodes improves gastrointestinal motility by balancing sympathovagal activities in a rat model of constipation

Electroacupuncture (EA) has been reported for treating constipation in clinical studies. However, little is known of the possible mechanisms involved in the prokinetic effect of EA. The aim of this study was to investigate the effects and underlying autonomic mechanisms of EA via chronically implanted electrodes for constipation in rat induced by Loperamide (Lop). Lop was given to regular rats to induce constipation. EA was performed via a pair of electrodes chronically implanted at bilateral acupoint ST-36. Feces characteristics, gastric emptying, small intestinal transit, distal colon transit time (dCTT), and whole gut transit time (WGTT) were measured in various sessions with EA or sham EA in rats with constipation induced by Lop. Heart rate variability (HRV) derived from the electrocardiogram was analyzed to evaluate autonomic functions. The number of fecal pellets was reduced by 27% with Lop (P < 0.01) and normalized by 7-day EA. Similar results were also observed in pellet weight. In normal rats compared with sham EA, EA shortened dCTT by 74% (P < 0.05 vs. sham EA), increased small intestinal transit by 28% (P < 0.01) and gastric emptying by 27% (P < 0.05), and accelerated whole gut transit by 14% (P < 0.05). In Lop-treated rats, the dCTT and WGTT were prolonged by Lop and normalized by EA. Lop significantly decreased vagal activity and increased sympathetic nerve activity; however, EA reversed these effects. EA at ST-36 via chronically implanted electrodes improves Lop-induced constipation by enhancing GI motility via the autonomic mechanisms. NEW & NOTEWORTHY The findings of the present study suggest that the proposed electroacupuncture (EA) may have great therapeutic potential for treating patients with opioid-induced constipation. It was demonstrated that EA at ST-36 improved transit of every organ along the gut mediated via the autonomic mechanisms in normal rats and rats with Lop-induced constipation. It is advised to administrate EA daily instead of two or three times weekly as reported in most of the clinical studies.

Electroacupuncture promotes the gastrointestinal motility of diabetic mice by CNP/NPR-B-cGMP and PDE3A-cGMP signaling

BACKGROUND

Electroacupuncture (EA) can promote gastrointestinal (GI) motility of diabetic mice, but the mechanism is not clearly elucidated. Natriuretic peptides (NPs) were related to the diabetes-induced gut dysfunction of mice, which may be associated with ICC (interstitial cells of cajal). Besides, EA could increase the ICC of diabetic mice. Our aim was to explore whether EA can promote the gut motility by CNP/NPR-B-cGMP and PDE3A-cGMP signaling in diabetic mice, and the relationship between NPs and ICC.

METHODS

Wild C57BL/6 male mice were divided into five groups: control group, diabetic mellitus (DM group), diabetic mellitus plus sham EA group (SEA), diabetic mellitus plus low-frequency EA group (LEA), and diabetic mellitus plus high-frequency group (HEA). Gastrointestinal motility was assessed by gastric emptying and GI transit test. Immunofluorescence staining was applied to assess the expression level of CNP, NPR-B, and c-Kit. Western blot, PCR, and ELISA were used to detect the level of CNP, NPR-B, PDE2A, PDE3A, c-Kit, mSCF, and cGMP content. The correlativity between NPR-B and mSCF was evaluated by Pearson's correlation and linear regression analyses.

KEY RESULTS

(a) EA could improve the GI dysfunction of diabetic mice. (b) CNP, NPR-B, and cGMP contents were decreased, but the level of PDE3A, c-Kit, and mSCF was increased in the EA groups. (c) There was a negative correlation between NPR-B and mSCF among the groups.

CONCLUSIONS AND INFERENCES

Electroacupuncture promotes the GI function by CNP/NPR-B-cGMP and PDE3A-cGMP signaling in diabetic mice; up-regulated mSCF/c-Kit signaling by EA may be mediated partially via down-regulation of CNP/NPR-B signaling.

Electroacupuncture promotes peripheral nerve regeneration after facial nerve crush injury and upregulates the expression of glial cell-derived neurotrophic factor

The efficacy of electroacupuncture in the treatment of peripheral facial paralysis is known, but the specific mechanism has not been clarified. Glial cell-derived neurotrophic factor (GDNF) has been shown to protect neurons by binding to N-cadherin. Our previous results have shown that electroacupuncture could increase the expression of N-cadherin mRNA in facial neurons and promote facial nerve regeneration. In this study, the potential mechanisms by which electroacupuncture promotes nerve regeneration were elucidated through assessing the effects of electroacupuncture on GDNF and N-cadherin expression in facial motoneurons of rabbits with peripheral facial nerve crush injury. New Zealand rabbits were randomly divided into a normal group (normal control, n = 21), injury group (n = 45) and electroacupuncture group (n = 45). Model rabbits underwent facial nerve crush injury only. Rabbits in the electroacupuncture group received facial nerve injury, and then underwent electroacupuncture at Yifeng (TE17), Jiache (ST6), Sibai (ST2), Dicang (ST4), Yangbai (GB14), Quanliao (SI18), and Hegu (LI4; only acupuncture, no electrical stimulation). The results showed that in behavioral assessments, the total scores of blink reflex, vibrissae movement, and position of apex nasi, were markedly lower in the EA group than those in the injury group. Hematoxylin-eosin staining of the right buccinator muscle of each group showed that the cross-sectional area of buccinator was larger in the electroacupuncture group than in the injury group on days 1, 14 and 21 post-surgery. Toluidine blue staining of the right facial nerve tissue of each group revealed that on day 14 post-surgery, there was less axonal demyelination and fewer inflammatory cells in the electroacupuncture group compared with the injury group. Quantitative real time-polymerase chain reaction showed that compared with the injury group, N-cadherin mRNA levels on days 4, 7, 14 and 21 and GDNF mRNA levels on days 4, 7 and 14 were significantly higher in the electroacupuncture group. Western blot assay displayed that compared with the injury group, the expression of GDNF protein levels on days 7, 14 and 21 were significantly upregulated in the electroacupuncture group. The histology with hematoxylin-eosin staining and Nissl staining of brainstem tissues containing facial neurons in the middle and lower part of the pons exhibited that on day 7 post-surgery, there were significantly fewer apoptotic neurons in the electroacupuncture group than in the injury group. By day 21, there was no significantly difference in the number of neurons between the electroacupuncture and normal groups. Taken together, these results have confirmed that electroacupuncture promotes regeneration of peripheral facial nerve injury in rabbits, inhibits neuronal apoptosis, and reduces peripheral inflammatory response, resulting in the recovery of facial muscle function. This is achieved by up-regulating the expression of GDNF and N-cadherin in central facial neurons.

PI3Kinases in Diabetes Mellitus and Its Related Complications

Recent studies have shown that phosphoinositide 3-kinases (PI3Ks) have become the target of many pharmacological treatments, both in clinical trials and in clinical practice. PI3Ks play an important role in glucose regulation, and this suggests their possible involvement in the onset of diabetes mellitus. In this review, we gather our knowledge regarding the effects of PI3K isoforms on glucose regulation in several organs and on the most clinically-relevant complications of diabetes mellitus, such as cardiomyopathy, vasculopathy, nephropathy, and neurological disease. For instance, PI3K α has been proven to be protective against diabetes-induced heart failure, while PI3K γ inhibition is protective against the disease onset. In vessels, PI3K γ can generate oxidative stress, while PI3K β inhibition is anti-thrombotic. Finally, we describe the role of PI3Ks in Alzheimer’s disease and ADHD, discussing the relevance for diabetic patients. Given the high prevalence of diabetes mellitus, the multiple effects here described should be taken into account for the development and validation of drugs acting on PI3Ks.

Neurotrophic factors in enteric physiology and pathophysiology

Neurotrophic factors are traditionally recognized for their roles in differentiation, growth, and survival of specific neurons in the central and peripheral nervous system. Some neurotrophic factors are essential for the development and migration of the enteric nervous system along the fetal and post-natal gut. Over the last two decades, several non-developmental functions of neurotrophic factors have been characterized. In the adult gastrointestinal tract, neurotrophic factors regulate gut sensation, motility, epithelial barrier function, and protect enteric neurons and glial cells from damaging insults in the microenvironment of the gut. In this issue of Neurogastroenterology and Motility, Fu et al demonstrate that brain-derived neurotrophic factor plays a role in the pathogenesis of distention-induced abdominal pain in bowel obstruction. In light of this interesting finding, this mini-review highlights some of the recent advances in understanding of the physiological and pathophysiological roles of neurotrophic factors in the adult gut.

Electroacupuncture treatments for gut motility disorders

Functional gastrointestinal (GI) diseases are common and there are patients who are refractory to medical therapies as not all treatments work in all patients. Consequently, a large number of patients with functional GI diseases use complementary and alternative medicine, such as acupuncture or electroacupuncture (EA). In this issue, Zheng et al. reported interesting results of a multi-center placebo-controlled clinical study on the use of EA for treating refractory functional dyspepsia; another study reported a multi-center clinical trial on EA for chronic functional constipation; Liang et al. studied mechanisms of EA involving enteric nervous system and neurotransmitters in treating constipation in rats. While controversial reports are available in the literature, EA with appropriate methodologies as shown in these recent studies is believed to be effective in treating certain functional GI diseases. In this mini-review, a number of clinical studies, including those included in this issue on the use of EA for treating gastro-esophageal reflux, functional dyspepsia, irritable bowel syndrome, and constipation are reviewed. Some critically important issues, such as the choice of stimulation parameters for EA, the administration frequency of the therapy, and the appropriate choice of placebo for clinical research are also discussed. Mechanisms of action involved in the therapeutic effects of EA for gut dysmotility and future research directions are also presented.

Effect of Electroacupuncture on 99mTc-Sodium Pertechnetate Uptake and Extracellular Fluid Free Molecules in the Stomach in Acupoint ST36 and ST39

Electroacupuncture (EA) is a therapeutic modality in which the electrical stimulation is integrated with concepts of acupuncture to treat diseases. This study was designed to evaluate the connection between the electro-acupuncture induced increase in Na^99mTcO4 uptake in the stomach wall, and the ionic molecule levels in the extracellular fluid in the acupoints. Wistar rats were treated by 2 or 100 Hz EA at Zusanli (ST 36) and Xiajuxu (ST 39) bilaterally for 60 minutes. The accumulation of Na^99mTcO4 in the gastric wall and the free ions, including Ca²⁺, K⁺, Na⁺, and Cl⁻, in the acupoints were measured every 60 minutes. The radioactivity uptake in the stomach was significantly increased during EA, reaching peak at 180 minutes after the EA. The concentration of extracellular ions was also significantly increased during EA. The Ca²⁺ level continued to rise until 60 minutes after EA, then started to decrease at 120 minutes post-EA. The results suggest this up-regulatory effect of EA on gastric activity might be triggered by the increase of the extracellular ion levels, this effect lasts longer than stimulating the release of transmembrane Ca²⁺ flow alone. This might aid in providing a better understanding of the long-lasting effect claimed in acupuncture treatment.

High-frequency (50 Hz) electroacupuncture ameliorates cognitive impairment in rats with amyloid beta 1-42-induced Alzheimer's disease

Acupuncture has been shown to ameliorate cognitive impairment of Alzheimer's disease. Acupoints and stimulation frequency influence the therapeutic effect of electroacupuncture. Rat models of Alzheimer's disease were established by injecting amyloid beta 1–42 (Aβ_1–42) into the bilateral lateral ventricles. Electroacupuncture at 2, 30, and 50 Hz was carried out at Baihui (GV20; 15° obliquely to a depth of 2 mm) and Shenshu (BL23; perpendicularly to 4–6 mm depth), once a day for 20 minutes (each), for 15 days, taking a break every 7 days. The Morris water maze test was conducted to assess the learning and memory. The expression levels of glycogen synthase kinase-3β (GSK-3β), pSer9-GSK-3β, pTyr216-GSK-3β, amyloid precursor protein and Aβ_1–40 in the hippocampus were determined by western blot assay. Results demonstrated that electroacupuncture treatment at different frequencies markedly improved learning and memory ability, increased synaptic curvatures, decreased the width of synaptic clefts, thickened postsynaptic densities, and downregulated the expression of GSK-3β, amyloid precursor protein, and Aβ_1–40. pSer9-GSK-3β expression markedly decreased, while pTyr216-GSK-3β expression increased. High-frequency (50 Hz) electroacupuncture was more effective than low (2 Hz) or medium-frequency (30 Hz) electroacupuncture. In conclusion, electroacupuncture treatment exerts a protective effect against Aβ_1–42-induced learning and memory deficits and synapse-ultrastructure impairment via inhibition of GSK-3β activity. Moreover, high-frequency electroacupuncture was the most effective therapy.

Applications of Acupuncture Therapy in Modulating Plasticity of Central Nervous System

OBJECTIVE

Acupuncture is widely applied for treatment of various neurological disorders. This manuscript will review the preclinical evidence of acupuncture in mediating neural plasticity, the mechanisms involved.

MATERIALS AND METHODS

We searched acupuncture, plasticity, and other potential related words at the following sites: PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and VIP information data base. The following keywords were used: acupuncture, electroacupuncture, plasticity, neural plasticity, neuroplasticity, neurogenesis, neuroblast, stem cell, progenitor cell, BrdU, synapse, synapse structure, synaptogenesis, axon, axon regeneration, synaptic plasticity, LTP, LTD, neurotrophin, neurotrophic factor, BDNF, GDNF, VEGF, bFGF, EGF, NT-3, NT-4, NT-5, p75NTR, neurotransmitter, acetylcholine, norepinephrine, noradrenaline, dopamine, monamine. We assessed the effects of acupuncture on plasticity under pathological conditions in this review.

RESULTS

Relevant references were reviewed and presented to reflect the effects of acupuncture on neural plasticity. The acquired literatures mainly focused on neurogenesis, alterations of synapses, neurotrophins (NTs), and neurotranimitters. Acupuncture methods mentioned in this article include manual acupuncture and electroacupuncture.

CONCLUSIONS

The cumulative evidences demonstrated that acupuncture could induce neural plasticity in rodents exposed to cerebral ischemia. Neural plasticity mediated by acupuncture in other neural disorders, such as Alzheimer's disease, Parkinson's disease, and depression, were also investigated and there is evidence of positive role of acupuncture induced plasticity in these disorders as well. Mediation of neural plasticity by acupuncture is likely associated with its modulation on NTs and neurotransmitters. The exact mechanisms underlying acupuncture's effects on neural plasticity remain to be elucidated. Neural plasticity may be the potential bridge between acupuncture and the treatment of various neurological diseases.

Schisandrin rescues depressive-like behaviors induced by chronic unpredictable mild stress via GDNF/ERK1/2/ROS and PI3K/AKT/NOX signaling pathways in mice

The current study aimed to prove the antidepressant-like effects and the probable mechanisms of Schisandrin on depression, which induced by chronic unpredictable mild stress (CUMS) in mice. Four weeks of CUMS exposure resulted in depressive-like behavior, as indicated by the significant decrease in sucrose consumption and increase the immobility time in the forced swim test, but without any influence on the locomotor activity. Further, there were significant downregulations of GDNF/ERK1/2/ROS and PI3K/AKT/NOX signaling pathways in the hippocampus and prefrontal cortex in depressed mice. Treatment of mice with Schisandrin (30mg/kg) and Fluoxetine (10mg/kg) significantly ameliorated all the behavioral and biochemical changes induced by CUMS. These results suggest that Schisandrin produces an antidepressant-like effect in CUMS-induced mice, which possibly mediated, at least in part, by rectifying the signaling pathways of GDNF/ERK1/2/ROS and PI3K/AKT/NOX.

Roles of electro-acupuncture in glucose metabolism as assessed by 18F-FDG/PET imaging and AMPKα phosphorylation in rats with ischemic stroke

Targeted energy metabolism balance contributes to neural survival during ischemic stroke. Herein, we tested the hypothesis that electro‑acupuncture (EA) can enhance cerebral glucose metabolism assessed by 18F‑fluorodeoxyglucose/positron emission tomography (18F‑FDG/PET) imaging to prevent propagation of tissue damage and improve neurological outcome in rats subjected to ischemia and reperfusion injury. Rats underwent middle cerebral artery occlusion (MCAO) and received EA treatment at the LI11 and ST36 acupoints or non‑acupoint treatment once a day for 7 days. After EA treatment, a significant reduction in the infarct volume was determined by T2‑weighted imaging, accompanied by the functional recovery in CatWalk and Rota-rod performance. Moreover, EA promoted higher glucose metabolism in the caudate putamen (CPu), motor cortex (MCTX), somatosensory cortex (SCTX) regions as assessed by animal 18F‑FDG/PET imaging, suggesting that three‑brain regional neural activity was enhanced by EA. In addition, the AMP‑activated protein kinase α (AMPKα) in the CPu, MCTX and SCTX regions was phosphorylated at threonine 172 (Thr172) after ischemic injury; however, phosphorylation of AMPK was further increased by EA. These results indicate that EA could promote AMPKα phosphorylation of the CPu, MCTX and SCTX regions to enhance neural activity and motor functional recovery after ischemic stroke.

Gastric electrical stimulation improves enteric neuronal survival

Research and clinical experience with vagotomy have confirmed that damage to the central nervous system severely affects physiological movement in the gastrointestinal system. The aim of this study was to investigate the effects of synchronized dual-pulse gastric electrical stimulation (SGES) on the apoptosis of enteric neurons and the possible pathways involved in these effects in vagotomized rats. For this purpose, Male Sprague-Dawley (SD) rats were randomized into a control group, an early subdiaphragmatic vagotomized group (ESDV group), an early subdiaphragmatic vagotomized group with short-term SGES (ESDV + SSGES group), a terminal subdiaphragmatic vagotomized group (TSDV group) and a terminal subdiaphragmatic vagotomized group with long-term SGES (TSDV + LSGES group). The expression levels of connexin 43 (Cx43), glial cell line-derived neurotrophic factor (GDNF), p-Akt, pan-Akt and PGP9.5 were assessed by RT-qPCR, western blot analysis and immunofluorescence staining. Apoptosis was determined by terminal-deoxynucleoitidyl transferase-mediated nick-end labeling (TUNEL) assay. We found that Cx43 expression was decreased in the ESDV and TSDV groups, but was significantly upregulated in the SSGES and LSGES groups. In addition, the GDNF and PGP9.5 expression levels were significantly decreased in the ESDV group compared with the control and TSDV groups and were upregulated in both the SSGES and LSGES groups. The LSGES group exhibited a clear increase in p-Akt expression compared with the TSDV group. Fewer TUNEL-positive cells were observed in the SSGES and LSGES groups than in the ESDV and TSDV groups. More TUNEL-positive cells were found in the stomach of rats subjected to subdiaphragmatic vagotomy. On the whole, our data indicate that SGES improved enteric neuronal survival, possibly through GDNF and the phosphatidylinositol 3-kinase (PI3K)/Akt pathways.

Effect of Electroacupuncture on the NTS is modulated primarily by acupuncture point selection and stimulation frequency in normal rats

Background

The effect of electroacupuncture (EA) is affected by both the acupuncture point selection and the frequency of stimulation. However, little is known regarding acupuncture point and simulation frequency selection. Neuronal activation of the nucleus of the solitary tract (NTS) is one of the important targets of EA for modulating gastrointestinal function. This study investigated the effects of various combinations of EA frequencies and acupuncture points on NTS neurons.

Methods

Rats were randomly divided into normal, 2 Hz EA, 100 Hz EA and the alternate 2/100 Hz EA groups. Then rats in each group were randomly divided into the following two subgroups according to the acupuncture point: ST 36 group and ST 25 group. All the rats underwent electrode implantation surgery. Rats in all EA groups received one treatment with EA (a constant square wave at, 2 Hz,100 Hz or 2/100 Hz frequencies with intensities ranging from 1 to 2 mA), and NTS neuronal activation was recorded before and after EA treatment. Finally, to confirm the effect of EA on the NTS, minimal acupuncture was administered and its effect on NTS was detected.

Results

ST 36 stimulated with 2 Hz EA significantly increased the population of excited NTS neurons and spike frequency. However, ST 36 stimulated with 100 Hz or 2/100 Hz EA produced only a transient effect on the activity of NTS neurons and did not induce any effect on the spike frequency. Furthermore, the excitatory effect of 100 Hz or 2/100 Hz EA on NTS neurons in the ST 36 group was lower than 2 Hz EA at the same point. When applied to ST 25, 2 Hz EA had no significant excitatory effect on NTS neurons or spike frequency. However, 100 Hz EA or 2/100 Hz EA at ST 25 decreased both NTS neuronal excitability and spike frequency. By comparing the effects of different EA combinations, it was shown 2 Hz EA applied to ST 36 had the strongest excitatory effect on NTS neurons, while 100 Hz EA applied to ST 25 had the greatest inhibitory effect. Minimal acupuncture stimulation produced no effect on NTS neurons.

Conclusion

EA’s effects on NTS were mainly affected by the acupuncture point selection, but the frequency of EA also played a role. Different combinations of acupuncture points and frequency selection may lead to different EA effects on NTS neuronal excitability.

The Effects of Auricular Electro-Acupuncture on Ameliorating the Dysfunction of Interstitial Cells of Cajal Networks and nNOSmRNA Expression in Antrum of STZ-Induced Diabetic Rats

BACKGROUD

Interstitial cells of Cajal (ICCs) and nNOS play a crucial role in diabetic gastrointestinal dysmotility(DGD). Our previous study found that electro-acupuncture(EA) on ear point 'stomach' could repair the gastric dysrhythmias in rats induced by rectal distention(RD) after meal. However, little were known about the possible effect of auricular electro-acupuncture (AEA) on diabetic rats. Thus, we designed this study to investigate the effect of AEA on streptozotocin(STZ)-induced diabetic rats.

METHOD

Forty male Sprague_Dawley (SD) rats were injected with STZ, at the end of 8th week after injection, animals were randomly divided into four groups and received 2 weeks-treatment(10 times) respectively: control group(CON,n = 10, no stimulation), sham auricular electro-acupuncture group(SEA,n = 10, low frequency EA on earlobes), auricular eletro-acupuncture group(AEA,n = 10, low frequency EA on ear point 'stomach'), and ST-36 group(ST-36,n = 10, low frequency EA on ST-36). Gastrointestinal (GI) motility was measured by GI transit rate. ICCs(c-kit+ expression) in antrum were analyzed by Immunohistochemistry and western blotting. NO level in blood serum were detected by Griess Reagent, and nNOSmRNA expression in antrum were determined by Real-time PCR.

RESULTS

GI transit rate and ICCs(c-kit+ expression) in antrum of AEA group have the tendency to increase compared with CON group, but had no statistics difference (P>0.05). nNOSmRNA expression in antrum of AEA group was dramatically increased compared with CON group (P = 0.037).

CONCLUSIONS

Low frequency EA on ear 'stomach' point could significantly up-regulate nNOS mRNA expression and ameliorate the ICCs networks partly in gastric antrum of STZ -induced diabetic rats, which may has benefits on regulating the GI motility.

Electroacupuncture protects against ischemic stroke by reducing autophagosome formation and inhibiting autophagy through the mTORC1-ULK1 complex-Beclin1 pathway

In a previous study by our group, we demonstrated that electroacupuncture (EA) activates the class I phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. There is considerable evidence that the downstream mammalian target of rapamycin complex 1 (mTORC1) plays an important role in autophagy following ischemic stroke. The aim of the present study was to determine whether EA exerts a neuroprotective effect through mTORC1-mediated autophagy following ischemia/reperfusion injury. Our results revealed that EA at the LI11 and ST36 acupoints attenuated motor dysfunction, improved neurological deficit outcomes and decreased the infarct volumes. The number of autophagosomes, autolysosomes and lysosomes was decreased following treatment with EA. Simultaneously, the levels of the autophagosome membrane maker, microtubule-associated protein 1 light chain 3 beta (LC3B)II/I, Unc-51-like kinase 1 (ULK1), autophagy related gene 13 Atg13) and Beclin1 (ser14) were decreased, whereas mTORC1 expression was increased in the peri-infarct cortex. These results suggest that EA protects against ischemic stroke through the inhibition of autophagosome formation and autophagy, which is mediated through the mTORC1-ULK complex-Beclin1 pathway.