Wei-Tong-Xin ameliorated cisplatin-induced mitophagy and apoptosis in gastric antral mucosa by activating the Nrf2/HO-1 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Wei-Tong-Xin (WTX) originated from the famous ancient Chinese formula "Wan Ying Yuan", recorded in the ancient Chinese medicine book "Zhong Zang Jing" by Hua Tuo. As "Jun" drugs, Dahuang and Muxiang have the effects of clearing heat and expelling fire, reducing food retention, regulating Qi and relieving pain. As "Chen" drug, Qianniuzi has the effect of assisting "Jun" drugs. Zhuyazao and Gancao, as "Zuo-Shi" drugs, can reduce toxicity and modulate the medicinal properties of other herbs. AIM OF THE STUDY: The present study aimed to investigate the effect and mechanism of WTX on the oxidative stress of gastric antrum mucosa in mice with cisplatin (CIS)-induced dyspepsia. MATERIALS: AND. METHODS: A variety of experimental methods, including western blot, qRT-PCR, immunofluorescence and immunohistochemistry were performed in vivo and in vitro. RESULTS: In vivo, WTX restored the number and function of interstitial cells of Cajal (ICCs), accompanied by the inhibition of lipid peroxidation. Moreover, WTX inhibited the activation of Parkin-dependent mitophagy and apoptosis. In vitro, WTX activated the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway and inactivated mitophagy in GES-1 cells. To explore the role of Nrf2 in WTX's improvement of CIS-induced cell damage, Nrf2 inhibitor ML385 was used in cell experiments. We found that ML385 counteracted the regulation of WTX on mitophagy and apoptosis. Finally, N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, was applied in our experiments, and the results suggested that WTX suppressed the CIS-induced apoptosis via mitochondrial pathway. CONCLUSIONS: The above results, for the first time, indicated that WTX inhibited mitophagy and apoptosis of gastric antral mucosal cells induced by CIS through the Nrf2/HO-1 signaling pathway.

[Electroacupuncture promotes gastrointestinal motility by activating autophagy of Cajal interstitial cells via downregulating PI3K/Akt/mTOR signaling pathway in stomach of diabetic gastro-paresis rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Zusanli" (ST36), "Sanyinjiao" (SP6) and "Liangmen" (ST21) on gastrointestinal motility, blood glucose content and expression of autophagy-related proteins 1 light chain 3 (LC3), p62, phosphatidyli-nositol-3 kinase (PI3K), protein kinase B (Akt), p-Akt and mammalian target protein of rapamycin (mTOR) of interstitial cells of Cajal (ICCs) in the cultured gastric antrum cells in diabetic gastroparesis (DGP) rats, so as to reveal its mechanisms underlying improvement of DGP. METHODS: A total of 45 Sprague Dawley (SD) rats were randomly divided into blank control, model, EA, medication (3-methyladenine, 3-MA) and EA+3-MA groups, with 9 rats in each group. The DGP model was established by intraperitoneal injection of 2% streptozotocin (STZ) combined with high-fat and high sugar diet for 8 weeks. The gastric emptying rate was measured by using gavage of phenol red (to measure the propelling length of the phenol red/total length of small intestine ×100%). The symptom score (mental state, coat color and luster, behavior and activity, stool traits) of rats was observed every week and the blood glucose content was measured by using a glucometer. EA (20 Hz/100 Hz, 2 mA) was applied to unilateral ST36, SP6 and ST21 alternatively for 15 min, once daily, 5 days a week for 3 weeks. Rats of the 3-MA and 3-MA+EA groups received intraperitoneal injection of 3-MA (30 mg·kg-1·d-1, 10 mg/mL), once daily, 5 days a week for 3 weeks. After 15 days' intervention, the rats were operated for gastric emptying rate test, specimen collection, isolation, and culture of primary ICCs. The expression levels of microtubule associated protein LC3, p62, PI3K, Akt, p-Akt and mTOR of ICCs of cultured gastric antrum cells were detected using Western blot, and the number of autophagosomes in ICC of gastric antrum was observed under transmission electron microscope. RESULTS: Compared with the blank control group, the symptom score, blood glucose, and the expression levels of p62, class Ⅰ PI3K, Akt, p-Akt and mTOR proteins were increased significantly (P<0.01), while the gastric emptying rate and ratio of LC3Ⅱ/LC3Ⅰ and the expression level of class Ⅲ PI3K protein were significantly decreased (P<0.05, P<0.01) in the model group. In comparison with the model group, the increase of symptom score, blood glucose, and expression levels of p62, class Ⅰ PI3K, Akt, p-Akt and mTOR proteins and the decrease of gastric empty rate and LC3Ⅱ/LC3Ⅰ ratio and the expression level of class Ⅲ PI3K protein were all reversed in both EA and EA+3-MA groups (P<0.05, P<0.01), rather than in the 3-MA group. In addition, 3-MA also reversed modeling-induced increase of class Ⅰ PI3K, Akt, p-Akt and mTOR proteins expression (P<0.01). No significant differences were found between the EA and EA+3-MA in downregulating the levels of symptom score and blood glucose content, and in upregulating gastric empty rate(P>0.05). The effect of EA was notably superior to that of EA+3-MA in upregulating the ratio of LC3Ⅱ/LC3Ⅰ and the expression level of class Ⅲ PI3K protein, and in downregulating the expression of p62, class Ⅰ PI3K, Akt, p-Akt and mTOR proteins (P<0.05, P<0.01). The findings of transmission electron microscopy showed obvious swelling, breakage of some mitochondrial cristae in the ICC cells of antrum and no autophagosomes in the model group and 3-MA group, which was milder in the damage of mitochondrial cristae and marked increase in the autophagosomes in both EA and EA+3-MA groups. CONCLUSION: EA can improve the gastrointestinal motility and symptoms in DGP rats, which may be related to its functions in downregulating PI3K/Akt/mTOR signaling to promote autophagy level of ICC.

Effects of Simo decoction on gastric motility of diabetic rats.

BACKGROUND: To investigate the effects of simo decoction (SMD) on the gastric motility of diabetic rats. METHODS: Diabetic rats were gavaged with various doses of SMD (0.15, 1.5, and 3.0 ml/kg/d) or saline, and their blood glucose levels and body weight were monitored. Gastric emptying and antral motility were assessed by phenol red retention and contractions of antral strips, respectively. The levels of substance P (SP), vasoactive intestinal peptide (VIP), and neurogenic nitric oxide synthase (nNOS) in the gastric antrum were determined by real-time polymerase chain reaction and Western blot. RESULTS: Gastric emptying was delayed in diabetic rats (p < 0.01 vs. non-diabetic controls) but accelerated after SMD administration (p < 0.01). The contractions of antral strips were reduced in diabetic rats (p < 0.01 vs. non-diabetic controls) but improved after SMD intervention (p < 0.05). The mRNA expressions of SP, VIP, and nNOS in diabetic rats were downregulated compared with non-diabetic controls (all p < 0.01). Simo decoction treatment did not affect the expression of these factors in diabetic rats. The protein levels of SP, VIP, and nNOS in diabetic rats were decreased (p < 0.01), increased (p < 0.01), and comparable (p > 0.05), respectively, in comparison with non-diabetic controls. Simo decoction administration increased SP protein expression (p < 0.01) and decreased the levels of VIP (p < 0.01) and nNOS (p < 0.01) in diabetic rats. CONCLUSIONS: Simo decoction improved gastric dysmotility of diabetic rats possibly by upregulating SP and downregulating VIP and nNOS.

[Effect of electroacupuncture combined with Zhuang-medicine-thread moxibustion on expression of apoptosis-related factors in gastric antrum of diabetic gastroparesis rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) combined with Zhuang-medicine-thread moxibustion on expression of apoptosis-related factors in gastric antrum of diabetic gastroparesis (DGP) rats, so as to explore its mechanism underlying improvement of DGP. METHODS: Male SD rats were randomly divided into normal, model, medication, EA, Zhuang-medicine-thread moxibustion (moxibustion) and EA+moxibustion (combination) groups (12 rats in each group). The DGP model was established by intraperitoneal injection of streptozotocin (STZ). Rats of the medication group were treated by gavage of 0.15 mg/mL mosapride citrate suspension （10 mL/kg）. EA (10 Hz/50 Hz, 2 mA, 20 min) or Zhuang-medicine-thread moxibustion (3 cones) was applied to "Zhongwan" (CV12), bilateral "Neiguan" (PC6) and bilateral "Sanyinjiao" (SP6) of the related groups, once a day for 3 weeks. The blood glucose, gastric emptying rate and intestinal propulsion rate of rats were measured. The apoptosis index of gastric antrum cells were observed by TUNEL staining. The protein and mRNA expressions of Caspase-3, B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in gastric antrum were detected by Wes-tern blot and real-time quantitative PCR, respectively. RESULTS: Compared with the normal group, the blood glucose, the apoptosis index, the protein and gene expressions of Caspase-3 and Bax were significantly increased (P<0.01), and the gastric emptying rate, intestinal propulsive rate, the protein and gene expressions of Bcl-2 were considerably decreased (P<0.01) in the model group. In contrast to the model group, the blood glucose in the EA, moxibustion and combination groups, the apoptosis index in the 4 treatment groups, as well as Caspase-3 protein, Bax protein and mRNA expressions in the medication, EA and combination groups, Caspase-3 protein and mRNA, Bax mRNA expressions in the moxibustion group were significantly decreased (P<0.01, P<0.05); while the gastric emptying rate and intestinal propulsive rate in the 4 treatment groups, and Bcl-2 protein and mRNA expressions in the medication and combination groups, Bcl-2 mRNA expressions in the EA and moxibustion groups were obviously increased (P<0.01). The effects of EA+moxibustion were significantly superior to those of simple EA, moxibustion or medication in increasing gastric emptying rate and intestinal propulsive rate, and in lowering blood glucose (P<0.05, P<0.01). And the effects of the combination treatment were better than those of EA in lowering Caspase-3 protein and Bax mRNA expressions (P<0.01), and in increasing Bcl-2 protein and mRNA expressions (P<0.05, P<0.01). Also the effects of the combination treatment were better than those of moxibustion in lowering the apoptosis index, Caspase-3 protein, and Bax protein and mRNA expressions (P<0.01, P<0.05), and in increasing Bcl-2 protein expression (P<0.05). CONCLUSION: EA combined with Zhuang-medicine-thread moxibustion can reduce blood glucose and improve gastrointestinal motility in DGP rats, which may be related to its effect in regulating of Caspase-3, Bax and Bcl-2 expression.

[Effect of electroacupuncture combined with Zhuang-medicine-thread moxibustion on silent information regulator-1/nuclear factor κB signaling pathway in gastric antrum of diabetic gastroparesis rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) combined with Zhuang-medicine-thread moxibustion on silent information regulator-1 (SIRT1)/nuclear factor kappa B (NF-κB) signal pathway and inflammatory factor expression in gastric antrum tissue of diabetic gastroparesis (DGP) rats, so as to explore its mechanism underlying improvement of DGP. METHODS: Male SD rats were randomly divided into normal, model, medication, EA, Zhuang-medicine-thread moxibustion (moxibustion) and EA+moxibustion groups (n=12 per group). The DGP model was established by intraperitoneal injection of streptozotocin (STZ). Rats of the medication group were treated by gavage of 0.15 mg/mL mosapride citrate suspension. EA (10 Hz /50 Hz, 2 mA) or moxibustion (3 cones) or EA+moxibustion was applied to "Zhongwan"(CV12), bilateral "Neiguan"(PC6) and bilateral "Sanyinjiao"(SP6) of the related group for 20 min, once a day for 3 weeks. Blood glucose, gastric emptying rate and intestinal propulsion rate were measured. The levels of serum interleukin (IL)-6, IL-8, IL-10 and tumor necrosis factor-α(TNF-α) were detected by ELISA; the phosphorylation level of the phosphorylated inhibitor of nuclear factor κBα inhibitor (pIκ-Bα), the protein and mRNA expression of NF-κB p65 and SIRT1 in the gastric antrum tissue were detected by Western blot and real-time quantifitative PCR, respectively. RESULTS: (1) Compared with the normal group, the levels of blood glucose, serum IL-6, IL-8, TNF-α, and gastric pIκ-Bα and NF-κB p65 protein and mRNA expressions were significantly increased (P<0.01), and the gastric emptying rate, intestinal propulsion rate, serum IL-10 level, and SIRT1 protein and mRNA expressions were considerably decreased in the model group (P<0.01). (2) In contrast to the model group, the blood glucose in the EA, moxibustion and EA+moxibustion groups, serum IL-6, IL-8 and TNF-α levels in the 4 treatment groups, as well as NF-κB p65 protein expression in the medication and EA+moxibustion groups, and NF-κB p65 mRNA expression and pIκ-Bα protein and mRNA expression in the 4 treatment groups were significantly decreased (P<0.01, P<0.05); while the gastric emptying rate and intestinal propulsive rate and IL-10 content in the 4 treatment groups, and SIRT1 protein and mRNA expression in the medication and EA+moxibustion groups were obviously increased (P<0.05, P<0.01). (3) The effects of EA+moxibustion were significantly superior to those of simple EA and moxibustion in increasing gastric emptying rate, IL-10, SIRT1 protein expression (P<0.05, P<0.01), and in lowering IL-8 and TNF-α contents, pIκ-Bα protein and mRNA expression and NF-κB p65 mRNA expression (P<0.05, P<0.01). No significant differences were found among the 4 intervention groups in promoting the intestinal propulsive rate and among the EA, moxibustion and EA+moxibustion groups in lowering blood glucose (P>0.05). CONCLUSION: EA combined with Zhuang-medicine-thread moxibustion can effectively reduce the level of serum inflammatory factors and regulate SIRT1/NF-κB signal pathway in DGP rats, which may contribute to its function in improving gastrointestinal movement.

Bmi1 marks gastric stem cells located in the isthmus in mice.

In the mammalian stomach, the isthmus has been considered as a stem cell zone. However, various locations and proliferative activities of gastric stem cells have been reported. We focused here on the stem cell marker Bmi1, a polycomb group protein, aiming to elucidate the characteristics of Bmi1-expressing cells in the stomach and to examine their stem cell potential. We investigated the Bmi1-expressing cell lineage in Bmi1-CreERT; Rosa26-YFP, LacZ or Rosa26-Confetti mice. We examined the in vivo and ex vivo effects of Bmi1-expressing cell ablation by using Bmi1-CreERT; Rosa26-iDTR mice. The Bmi1 lineage was also traced during regeneration after high-dose tamoxifen-, irradiation- and acetic acid-induced mucosal injuries. In the lineage-tracing experiments using low-dose tamoxifen, Bmi1-expressing cells in the isthmus of the gastric antrum and corpus provided progeny bidirectionally, towards both the luminal and basal sides over 6 months. In gastric organoids, Bmi1-expressing cells also provided progeny. Ablation of Bmi1-expressing cells resulted in impaired gastric epithelium in both mouse stomach and organoids. After high-dose tamoxifen-induced gastric mucosal injury, Bmi1-expressing cell lineages expanded and fully occupied all gastric glands of the antrum and the corpus within 7 days after tamoxifen injection. After irradiation- and acetic acid-induced gastric mucosal injuries, Bmi1-expressing cells also contributed to regeneration. In conclusion, Bmi1 is a gastric stem cell marker expressed in the isthmus of the antrum and corpus. Bmi1-expressing cells have stem cell potentials, both under physiological conditions and during regeneration after gastric mucosal injuries. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

[Effect of Point-moxibustion and Electroacupuncture on the Expression of Endothelial Nitric Oxide Synthase mRNA and Angiotensin 2 mRNA in Gastric Antrum in Diabetic Gastroparesis Rats].

OBJECTIVE: To observe the effect of point-moxibustion and electroacupuncture(EA) on gastrointestinal motility, and expression of endothelial nitric oxide synthase(eNOS) mRNA and angiotensin 2(AT Ⅱ) mRNA in gastric antrum in diabetic gastroparesis(DGP) rats, so as to reveal the different effect between point-moxibustion and EA, and explore the mechanism underlying improvement of DGP. METHODS: Forty SD rats were randomly divided into normal, model, point-moxibustion and EA groups, 10 rats in each group. The DGP model was established by intraperitoneal injection of streptozotocin (STZ, 2%, 55 mmol/kg) and fed with high-sugar and high-fat fodder. "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and "Liangmen" (ST 21) were chosen to be stimulated with moxibustion at 0, 10 and 20 min in the point-moxibustion group or with EA for 20 min in the EA group. The treatment was conducted once daily for 15 days. After treatment, blood glucose, gastric emptying rate and small intestinal propulsive rate were measured. The plasma endothelin 1(ET-1) content was detected by ELISA. The mRNA expression of eNOS and AT Ⅱ in gastric antrum were detected by Real-time PCR. RESULTS: Compared with the normal group, the blood glucose in the model group was significantly higher (P<0.01). Compared with the model group, the blood glucose decreased significantly in the point-moxibustion group and EA group (P<0.05). In comparison with the normal group, gastric emptying rate and small intestinal propulsive rate were decreased, the content of plasma ET-1 was increased, the expression of eNOS mRNA in gastric antrum was significantly reduced and the expression of ATⅡ mRNA was significantly increased in the model group(P<0.01). In comparison with the model group, gastric emptying rate and small intestinal propulsive rate were increased, the content of plasma ET-1 was decreased, the expression of eNOS mRNA in gastric antrum was higher and the expression of AT Ⅱ mRNA was significantly lower in both point-moxibustion group and EA group (P<0.05), and there were no significant differences between the two treatment groups in above mentioned indexes (P>0.05). CONCLUSIONS: Both point-moxibustion and EA can effectively promote gastrointestinal motility in DGP rats and improve the symptoms of delayed gastric emptying. The two therapies are effective, and their mechanism may be related to the increase of eNOS mRNA expression and the decrease of AT Ⅱ mRNA expression in gastric antrum.

[Effect of Electroacupuncture Intervention on Gastrointestinal Motility and Expression of Insulin-like Growth Factor 1 and Its Receptor Proteins in Gastric Antrum in Diabetic Gastroparesis Rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) intervention of "Zusanli"(ST 36), etc. on gastrointestinal motility and levels of insulin-like growth factor 1 (IGF-1) and IGF-1 receptor (IGF-1 R) proteins in the gastric antrum in diabetic gastroparesis (DGP) rats, so as to study its mechanism underlying improvement of DGP. METHODS: Fifty SD rats, half male and half female, were randomly allocated to control, model, EA acupoint, EA non-acupoint and medication (metoclopramide) groups (n=10 rats/group). The DGP model was induced by 2% streptozotocin (STZ, i.p.i.,55 mg/kg) and high fat-sugar forage for 8 weeks. EA (10 Hz/50 Hz, 2 mA) was applied to "Zusanli"(ST 36), "Liangmen"(ST 21), "Sanyinjiao"(SP 6) and non-acupoints (about 5 mm lateral to ST 36, ST 21 and SP 6, respectively) for 20 min, one daily for 15 days, and 1.7% metocloppramide (1 mL/100 g) was given (gavage) to rats of the medication group, once daily for 15 days. After the treatment, the rats' general conditions were scored, the blood glucose level was determined using a glucometer, and the gastrointestinal mobility was evaluated by measuring the gastric emptying rate (GER) and the intestinal propulsion rates (IPR) marked by oral-infused phenol red solution (50 mg/dL). The immunoactivity levels of IGF-1 and IGF-1 R of gastric antrum tissue were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: After modeling, the symptom integrative score, the blood glucose, IGF-1 and IGF-1 R levels were significantly increased (P<0.01), and the GER and IPR were notably decreased relevant to the control group (P<0.01). After EA stimulation of ST 36, ST 21 and SP 6, the symptom score, blood glucose, and IGF-1 and IGF-1 R levels of the gastric antrum were significantly reduced, while the GER and IPR were considerably increased (P<0.05,P<0.01). Except the GER and IPR were considerably increased in the medication group(P<0.05,P<0.01), no significant changes were found in the symptom integrative score, the blood glucose, IGF-1 and IGF-1 R levels in both EA non-acupoint and medication groups relevant to the model group (P>0.05),the GER and IPR in the EA non-acupoint group (P>0.05). Compared with the EA acupoint group, the symptom integrative score, IGF-1 and IGF-1 R levels were significantly increased in both EA non-acupoint and medication groups(P<0.05,P<0.01). CONCLUSIONS: EA stimulation can improve gastrointestinal motility and lower blood glucose in DGP rats, which may be closely associated with its effectiveness in reducing IGF-1 and IGF-1 R immunoactivity levels in gastric antrum.

Mechanisms of PTHrP-induced inhibition of smooth muscle contractility in the guinea pig gastric antrum.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) that causes hypercalcemia of malignancy appears to function as an endogenous smooth muscle relaxant. For example, PTHrP released upon bladder wall distension relaxes detrusor smooth muscle to accommodate urine. Here, we explored mechanisms underlying PTHrP-induced suppression of the smooth muscle contractility in the gastric antrum that also undergoes a passive distension. METHODS: Effects of PTHrP on phasic contractions and electrical slow waves in the antral smooth muscle of the guinea pig stomach were studied using isometric tension and intracellular microelectrode recordings, respectively. Fluorescent immunohistochemistry was also carried out to identify the distribution of PTH/PTHrP receptors. KEY RESULTS: Parathyroid hormone-related protein (1-100 nM) reduced the amplitude of phasic contractions and the basal tension. Nω -nitro-l-arginine (L-NA, 100 µM), a nitric oxide (NO) synthase inhibitor, or 1H-[1,2,4]oxadiazolo-[4, 3-a]quinoxalin-1-one (ODQ, 10 µM), a guanylate cyclase inhibitor, diminished the PTHrP (10 nM)-induced reduction in the amplitude of phasic contractions. SQ22536 (300 µM), an adenylate cyclase inhibitor, attenuated the PTHrP-induced reduction in basal tension. The combination of ODQ (10 µM) and SQ22536 (300 µM) inhibited the PTHrP-induced reductions in both phasic contractions and basal tension. PTHrP (100 nM) had no inhibitory effect on the electrical slow waves in the antral smooth muscle. PTH/PTHrP receptors were expressed in cell bodies of PGP9.5-positive neurons in the myenteric plexus. CONCLUSIONS & INFERENCES: Parathyroid hormone-related protein exerts its inhibitory actions on the antral smooth muscle via both nitric oxide-cyclic guanosine monophosphate (NO-cGMP) and cyclic adenosine monophosphate (AMP) pathways. Thus, PTHrP may act as an endogenous relaxant of the gastric antrum employing the two complementary signaling pathways to ensure the adaptive relaxation of stomach.

Advanced glycation end products interfere with gastric smooth muscle contractile marker expression via the AGE/RAGE/NF-κB pathway.

Excessive production of advanced glycation end products (AGE) has been implicated in the pathogenesis of diabetic complications. Smooth muscle (SM) phenotype transition is involved in diabetes-associated gastric motility dysfunction. We investigated whether AGE interfere with gastric antral SM contractile marker expression. Sixteen Sprague-Dawley rats were randomly divided into control and streptozotocin-induced diabetic groups. Sixteen weeks after streptozotocin administration, gastric antral SM strip contractility in the groups were measured. The gastric tissue expression of AGE was tested. Primary cultured gastric smooth muscle cells (SMCs) were used in complementary in vitro studies. In the presence and absence of AGE, SMCs were transfected with myocardin plasmid or treated with nuclear factor-κB (NF-κB) inhibitor or anti-RAGE antibody. Diabetic rats showed weakness of SM strip contractility and decreased expression of SM contractile marker genes (myosin heavy chains [MHC], α-actin, calponin) as compared with the control group. Gastric antral SM layer Nε-(carboxymethyl) lysine (CML) level, the major AGE compound, were increased in the diabetic rats. AGE downregulated SM contractile markers and myocardin expression in a concentration-dependent manner. Myocardin overexpression prevented these results. AGE treatment activated NF-κB in SMCs. The NF-κB inhibitor BAY 11-7082 and anti-RAGE antibody blocked the effects of AGE on myocardin downregulation. AGE may induce the development of gastric dysmotility by downregulating SM contractile proteins and myocardin expression via the AGE/RAGE/NF-κB pathway.

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.

Long-pulse gastric electrical stimulation protects interstitial cells of Cajal in diabetic rats via IGF-1 signaling pathway.

AIM: To investigate the effects of different parameters of gastric electrical stimulation (GES) on interstitial cells of Cajal (ICCs) and changes in the insulin-like growth factor 1 (IGF-1) signal pathway in streptozotocin-induced diabetic rats. METHODS: Male rats were randomized into control, diabetic (DM), diabetic with sham GES (DM + SGES), diabetic with GES1 (5.5 cpm, 100 ms, 4 mA) (DM + GES1), diabetic with GES2 (5.5 cpm, 300 ms, 4 mA) (DM + GES2) and diabetic with GES3 (5.5 cpm, 550 ms, 2 mA) (DM + GES3) groups. The expression levels of c-kit, M-SCF and IGF-1 receptors were evaluated in the gastric antrum using Western blot analysis. The distribution of ICCs was observed using immunolabeling for c-kit, while smooth muscle cells and IGF-1 receptors were identified using α-SMA and IGF-1R antibodies. Serum level of IGF-1 was tested using enzyme-linked immunosorbent assay. RESULTS: Gastric emptying was delayed in the DM group but improved in all GES groups, especially in the GES2 group. The expression levels of c-kit, M-SCF and IGF-1R were decreased in the DM group but increased in all GES groups. More ICCs (c-kit(+)) and smooth muscle cells (α-SMA(+)/IGF-1R(+)) were observed in all GES groups than in the DM group. The average level of IGF-1 in the DM group was markedly decreased, but it was up-regulated in all GES groups, especially in the GES2 group. CONCLUSION: The results suggest that long-pulse GES promotes the regeneration of ICCs. The IGF-1 signaling pathway might be involved in the mechanism underlying this process, which results in improved gastric emptying.

Effects of Electroacupuncture on Interstitial Cells of Cajal (ICC) Ultrastructure and Connexin 43 Protein Expression in the Gastrointestinal Tract of Functional Dyspepsia (FD) Rats.

BACKGROUND Gastrointestinal motility disorder is the main clinical manifestation in functional dyspepsia (FD) patients. Electroacupuncture is effective in improving gastrointestinal motility disorder in FD; however, the underlying mechanism remains unclear. It has been demonstrated that interstitial cells of Cajal (ICC) are pacemaker cells in the gastrointestinal tract, and the pacemaker potential is transmitted to nearby cells through gap junctions between ICC or ICC and the smooth muscle. Therefore, this study aimed to assess the effects of electroacupuncture on ICC ultrastructure and expression of the gap junction protein connexin 43 (Cx43) in FD rats. MATERIAL AND METHODS The animals were randomized into 3 groups: control, model, and electroacupuncture. Electroacupuncture was applied at Zusanli (ST36) in the electroacupuncture group daily for 10 days, while no electroacupuncture was applied to model group animals. RESULTS Ultrastructure of ICC recovered normally in gastric antrum and small intestine specimens was improved, with Cx43 expression levels in these tissues significantly increased in the electroacupuncture group compared with the model group. CONCLUSIONS These findings indicated that electroacupuncture is effective in alleviating ICC damage and reduces Cx43 levels in FD rats, and suggest that ICC and Cx43 are involved in electroacupuncture treatment in rats with FD to improve gastrointestinal motility disorders.

[Involvement of Neurotensin-mediated Brain-gut Axis in Electroacupuncture Intervention Induced Improvement of Functional Dyspepsia in Rats].

OBJECTIVE: To observe The effect of electroacupuncture (EA) stimulation of "Zusanli" (ST 36) and "Taichong" (LR 3) on intestinal motor and neurotensin (NT) levels in the plasma, hypothalamus, and gastro-antrum tissues in functional dyspepsia (FD) rats so as to reveal its mechanisms underlying improvement of FD. METHODS: Forty-eight SD rats were randomly divided into control, model and EA groups, with 16 rats in each group. The FD model was established by clamping the rats' tails and alternate day's feeding according to the related references. EA (2 Hz/100 Hz, 2 mA) was applied to unilateral ST 36 and LR 3 for 30 min, once daily for 14 days. Rats of the control group were only restricted. The gastric emptying rate and propulsive rate of the small intestine were detected. The content of NT in the plasma was assayed using ELISA, and the immunoactivity levels of NT in the hypothalamus, gastric antrum mucous membrane and ileum tissues were detected using immunohistochemistry. RESULTS: Compared with the control group, the gastric emptying rate and propulsive rate of the small intestine were considerably lowered in the model group (P < 0.01), and the content and immunoactivity levels of NT in the plasma, hypothalamus, mucous membrane of the gastric antrum and ileum tissues were significantly increased (P < 0.05). After EA intervention, the decreased gastric emptying rate and intestinal propulsive rate, as well as the increased NT content and immunoactivity levels of plasma, hypothalamus, gastric antrum and ileum were reversed (P < 0.05). CONCLUSION: EA intervention can obviously promote gastrointestinal motor in FD rats, which may be related to its function in down-regulating NT levels in the plasma, hypothalamus, gastric antrum and ileum. It suggests an involvement of NT in the brain-gut axis in EA-induced improvement of FD.

Auricular vagal nerve stimulation ameliorates burn-induced gastric dysmotility via sympathetic-COX-2 pathways in rats.

BACKGROUND: Severe burn injury has been demonstrated to delay gastric emptying. The aim of this study was to investigate effects and cellular mechanisms of auricular electroacupuncture (AEA) at the acupoints innervated by the auricular branch of vagus nerve on burn-induced gastric dysmotility in rats. METHODS: Propranolol (ß-adrenoceptor antagonist) was injected intraperitoneally after the rats underwent burn injury. All experiments were performed 6 h following burn/sham burn injury. AEA was performed at bilateral auricular acupoints for 45 min. Electrocardiogram was recorded for 30 min. Plasma hormones were measured; cyclooxygenase (COX)-2 expressions in gastric tissue were measured using western blotting and real-time RT-PCR. KEY RESULTS: (i) Burn injury delayed gastric emptying (p = 0.006) and AEA increased gastric emptying by 49% (p = 0.045). (ii) Burn injury evoked a significant elevation in plasma noradrenaline, which was suppressed by AEA. (iii) Burn injury significantly increased protein and mRNA expressions of COX-2 in gastric fundus and antrum. AEA suppressed burn-induced increase in protein expressions, but not mRNA expressions of COX-2. CONCLUSIONS & INFERENCES: Burn injury delays gastric emptying by up-regulating COX-2 attributed to sympathetic overactivity. AEA improves burn-induced delay in gastric emptying, possibly mediated via the sympathetic-COX-2 pathway.

[Effect of moxibustion with ignited Zhuang-medicine medicated-thread on interstitial cells of Cajal in gastric antrum in diabetic gastroparesis rats].

OBJECTIVE: To observe the effect of Zhuang-medicine medicated-thread moxibustion therapy on interstitial cells of Cajal (ICC) in the gastric antrum of diabetic gastroparesis (DGP) rats, so as to investigate its mechanism underlying improving DGP. METHODS: Sprague-Dawley (SD) male rats were randomly divided into 3 groups: control (n = 30) , model (n = 30) and moxibustion (n = 30). The DGP model was established by intraperitoneal injection of streptozotocin (STZ) and by feeding the rats with high fat-sugar forage. Zhuang-medicine medicated-thread moxibustion was applied to "Zhongwan" (CV 12), bilateral "Pishu" (BL 20), "Weishu" (BL 21), "Neiguan" (PC 6) and "Zusanli" (ST 36) once per day, for 3 weeks except weekends. The gastrointestinal propulsion rate and weight of stool in 24 h were determined, and c-kit (a marker for ICC) expression of the gastric antrum tissue was measured by immunohistochemistry. RESULTS: The stool weight was significantly higher in the model group than in the control group (P < 0.01), but the rate of gastrointestinal propulsion and the rate of c-kit immunoreaction (IR) positive cells in the gastric antrum tissue were significantly lower in the model group than in the control group (P < 0.01). After moxibustion, the increased stool weight and the decreased gastrointestinal propulsion rate and decreased c-kit IR-positive cell rate were reversed (P < 0.01). CONCLUSION: Zhuang-medicine medicated-thread moxibustion therapy can improve gastrointestinal function in DGP rats, which may be associated with its effect in up-regulating the expression of c-kit IR-positive ICC.

[Effect of manual acupuncture stimulation of "Zusanli" (ST 36) on gastric motility, and SP and motilin activities in gastric antrum and nucleus raphe magnus in gastric hyperactivity and hypoactivity rats].

OBJECTIVE: To observe the changes of gastric motility and levels of substance P (SP) and motilin (MTL) in the gastric antrum and Nucleus Raphe Magnus (NRM) after manual acupuncture stimulation of "Zusanli" (ST 36) in gastric hyperactivity and hypoactivity rats, so as to analyze the role of NRM in acupuncture mediated adjustment of gastric motility. METHODS: Fifty SD rats were randomly and equally divided into control, gastric hyperactivity (G-Hypera) model, gastric hypoactivity (G-Hypoa) model, acupuncture + G-Hypera and acupuncture + G-Hypoa groups (10 rats/group). G-Hypera model was established by intravenous (tail vein) injection of Maxolon (0.5 mL/200 g) and G-Hypoa model established by intravenous injection of Atropin (0.5 mL/200 g), respectively. After insertion of acupuncture needles into bilateral "Zusanli" (ST 36), the needles were repeatedly manipulated at a frequency of about 2 Hz for 5 min. The intragastric pressure was recorded and analyzed using a physiological signal analysis system. The SP and MTL contents of gastric antrum were measured by ELISA, and SP and MTL immunoactivity of NRM was determined by immunohistochemistry. RESULTS: In gastric hyperactivity rats, compared with the control group, the intragastric pressure (not systolic frequency), SP and MTL contents in the gastric antrum and MTL immunoactivity of NRM were significantly increased (P < 0.05, P < 0.01), while SP immunoactivity of NRM was apparently decreased in the G-Hypera model group (P < 0.01). After acupuncture stimulation, the intragastric pressure, gastric SP and MTL contents, and MTL immunoactivity of NRM were all significantly down-regulated (P < 0.05, P < 0.01), and SP immunoactivity of NRM was markedly up-regulated (P < 0.01) in comparison with the model group. In gastric hypoactivity rats, compared with the control group, the intragastric pressure and gastric systolic frequency, gastric SP and MTL contents, and MTL immunoactivity of NRM were significantly decreased (P < 0.05, PF < 0.01), while SP immunoactivity of NRM was remarkably up-regulated in the G-Hypoa model group (P < 0.01). After acupuncture stimulation, the above-mentioned 6 indexes were reversed significantly (P < 0.05, P < 0.01) in comparison with those of the model group. CONCLUSION: Acupuncture stimulation of "Zusanli" (ST 36) has an obvious bi-directional adjustment effect on gastric motility, which is closely associated with its functions in regulating gastric SP and MTL level and the expression of MTL and SP in the NRM of brainstem.

[Effect of banxia xiexin decoction on gastric antral interstitial cells of Cajal and stem cell factor in diabetic rats].

OBJECTIVE: To observe the effect of Banxia Xiexin Decoction (BXD) on expression of the interstitial cells of Cajal (ICCs) and stem cell factor (SCF) in the antrum of rats with diabetes mellitus (DM). METHODS: Totally sixty healthy male SD rats were randomly divided into the control group, the model group, the BXD group, and the Western medicine group (WM, treated by domperidone), 15 in each group. Diabetic rat models were established by a single intraperitoneal injection of streptozotocin (STZ, 55 mg/kg). Those in the BXD group were perfused with BXD at the daily dose of 5.4 g/kg. An equal volume of distilled water was given by gastrogavage to those in the WM group and the control group for 8 successive weeks. The body weight and blood glucose of all rats were detected, and the gastric residual rates were detected with semisolid nutrient paste by gastrogavage. The expression of positive ICCs and SCF were observed by immunohistochemical method and quantified image analyzer. RESULTS: Compared with the control group,the body weight reduced, blood glucose and gastric residual rates increased, and the mean optical density of positive ICCs and SCF significantly decreased in the model group (P < 0.05). Compared with the model group,symptoms such as polydipsia, polyphagia, polyuria were relieved, spirits improved, the body weight and mean optical densities of positive ICCs and SCF significantly increased (P < 0.05), and gastric residual rates significantly decreased in the BXD group and the WM group (P < 0.05). The blood glucose significantly decreased (P < 0.05) in the BXD group. The mean optical density of positive ICCs was higher in the BXD group than in the WM group (P < 0.05). CONCLUSIONS: BXD could promote the expression of positive ICCs and SCF. It could improve the gastric motility in DM rats by partially inverting abnormal changes of gastric antral ICCs and SCF.

[Effect of method of soothing liver and regulating qi on expression of gastrin and somatostatin in hypothalamus, castric antrum of functional dyspepsia rats].

OBJECTIVE: To explore the effects of the method of soothing the liver and regulating qi on expression of gastrin and somatostatin in hypothalamus and gastric antrum of functional dyspepsia model rats. METHOD: The 32 rats were randomly divided into normal group, model group, Chaihu Shugansan group and domperidone group (n = 8). The functional dyspepsia model was established by constantly squeezing their tails and mean while saline, Chaihu Shugansan decoction and domperidone suspension were administered respectively to 4 groups by gavage. The expression of gastrin and somatostatin in hypothalamus and gastric antrum of rats by immunohistochemical were detected 3 weeks later. RESULT: The expression of GAS in the hypothalamus and gastric antrum of model group were less than those of normal group (P < 0.05, P < 0.01), while the expression of SS in the hypothalamus and gastric antrum in Model group were significantly increased than those of normal group (P < 0.01). The expression of GAS and SS in gastric antrum of Chaihu Shugansan group and domperidone group were increased and decreased respectively, and the differences were significant (P < 0.05, P < 0.01). There were no obvious difference about expression of GAS, SS in the hypothalamus between domperidone group and model group. GAS expression in hypothalamus of Chaihu Shugansan group were increased than those of normal group but there was no obvious difference in SS expression in hypothalamus between Chaihu Shugansan group and model group. CONCLUSION: The method of soothing the liver and regulating qi can increase GAS expression in central and peripheral and decrease SS expression in peripheral gastric antrum, which may be one of its therapeutic mechanisms on functional dyspepsia.

[Influence of Qingxiang San on substance P, somatostatin in rats model with the spleen and stomach wet heat syndrome].

OBJECTIVE: To observe the influence of Qingxiang San (QS) on substance P (SP), somatostatin (SS) in rats model of spleen and stomach wet heat syndrome. METHODS: 24 rats were divided into 3 groups (each group 8 rats) randomly: the normal control group (NCG), wet heat group (WHG), QS group (QSG). We set up the spleen and stomach wet heat syndrome of rats model by the composite factors such as greasy and sweet food, wet and hot environment, pathogen and so on. Then the contents of SP, SS were detected by radioimmuno assay. RESULTS: The content of SP, SS in WHG were obviously lower than NCG (P<0.01); QSG compared with WHG, the content of SP, SS increased (P<0.01); The content of SP obviously increased when QSG compared with NCG (P<0.01); About the content of SS, there was no significant difference between QSG and NCG (P>0.05), illustrating that QS can increase the content of SP, SS which had decreased. CONCLUSION: QS can regulate the content of SP and SS and increase them which had decreased.