Colonic Muscle Research Articles

Conditional deletion of IP3R1 by Islet1-Cre in mice reveals a critical role of IP3R1 in interstitial cells of Cajal in regulating GI motility.

Inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) has been proposed to play a physiological role in regulating gastrointestinal (GI) motility, but the underlying cell-dependent mechanism remains unclear. Here, we utilized cell-specific IP3R1 deletion strategies to address this question in mice. Conditional IP3R1 knockout mice using Wnt1-Cre, Islet1-Cre mice, and smMHC-CreEGFP were generated. Cell lineage tracing was performed to determine where gene deletion occurred in the GI tract. Whole-gut transit assay and isometric tension recording were used to assess GI function in vivo and in vitro. In the mouse GI tract, Islet1-Cre targeted smooth muscle cells (SMCs) and interstitial cells of Cajal (ICCs), but not enteric neurons. IP3R1 deletion by Islet1-Cre (isR1KO) caused a phenotype of intestinal pseudo-obstruction (IPO), evidenced by prolonged whole-gut transit time, enlarged GI tract, abdominal distention, and early lethality. IP3R1 deletion by Islet1-Cre not only reduced the frequency of spontaneous contractions but also decreased the contractile responses to the muscarinic agonist carbachol (CCh) and electrical field stimulation (EFS) in colonic circular muscles. By contrast, smMHC-CreEGFP only targeted SMCs in the mouse GI tract. Although IP3R1 deletion by smMHC-CreEGFP (smR1KO)also reduced the contractile responses to CCh and EFS in colonic circular muscles, the frequency of spontaneous contractions was less affected, and neither global GI abnormalities nor early lethality was found in smR1KO mice. IP3R1 deletion in both ICCs and SMCs but not in SMCs alone causes an IPO phenotype, suggesting that IP3R1 in ICCs plays an essential role in regulating GI motility in vivo.

Lubiprostone Improves Distal Segment-Specific Colonic Contractions through TRPC4 Activation Stimulated by EP3 Prostanoid Receptor

Background: Prokinetic agents are effective in increasing gastrointestinal (GI) contractility and alleviating constipation, often caused by slow intestinal motility. Lubiprostone (LUB), known for activating CLC-2 chloride channels, increases the chloride ion concentration in the GI tract, supporting water retention and stool movement. Despite its therapeutic efficacy, the exact mechanisms underlying its pharmacological action are poorly understood. Here, we investigated whether LUB activates the canonical transient receptor potential cation channel type 4 (TRPC4) through stimulation with E-type prostaglandin receptor (EP) type 3. Methods: Using isotonic tension recordings on mouse colon strips, we examined LUB-induced contractility in both proximal and distal colon segments. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine mRNA levels of EP1-4 receptor subtypes in distal colonic muscular strips and isolated myocytes. The effects of a TRPC4 blocker and EP3 antagonist on LUB-stimulated contractions were also evaluated. Results: LUB showed significant contraction in the distal segment compared to the proximal segment. EP3 receptor mRNA levels were highly expressed in the distal colon tissue, which correlated with the observed enhanced contraction. Furthermore, LUB-induced spontaneous contractions in distal colon muscles were reduced by a TRPC4 blocker or EP3 antagonist, indicating that LUB-stimulated EP3 receptor activation may lead to TRPC4 activation and increased intracellular calcium in colonic smooth muscle. Conclusions: These findings suggest that LUB improves mass movement through indirect activation of the TRPC4 channel in the distal colon. The segment-specific action of prokinetic agents like LUB provides compelling evidence for a personalized approach to symptom management, supporting the defecation reflex.

Pharmacological characterization of alpha adrenoceptor-mediated motor responses in the rat colon.

Inhibitory neuromuscular transmission in the gastrointestinal tract is mediated by intrinsic nitrergic and purinergic neurons. Purines activate G protein-coupled receptor P2Y1 receptors, increasing intracellular Ca2+ that activates small conductance calcium-activated potassium (SKCa) channels. Little is known about the effect of adrenergic receptor activation on intestinal smooth muscle. In vascular tissue, stimulation of α-adrenoceptors causes smooth muscle contraction, while their effect on intestinal tissue is poorly understood. This study aimed to pharmacologically characterize the effect of α-adrenoceptor activation in the rat colon, which shares similar inhibitory pathways to the human colon. Muscle bath experiments were performed with the rat proximal, mid, and distal colon oriented both circularly and longitudinally. The α1-adrenoceptor agonist phenylephrine (PE) (10-8-10-5 M) evoked concentration-dependent relaxations of the intestinal smooth muscle from all regions and orientations. However, in the mid-circular colon at low PE concentrations, a contraction sensitive to 10-5 M phentolamine (non-selective α-adrenoceptor blocker), the neural blocker tetrodotoxin (TTX; 10-6 M), and atropine (10-6 M) was recorded. PE-induced relaxations were insensitive to TTX (10-6 M) and the nonselective β-adrenoceptor blocker propranolol (10-6 M). In contrast, PE-induced relaxations were blocked by phentolamine (10-5 M), prazosin (10-6 M) (α1-adrenoceptor blocker), and RS17053 (10-6 M) (α1A-blocker), but not by yohimbine (10-6 M) (α2-adrenoceptor blocker). Apamin (10-6 M), a SKCa channel blocker, abolished PE-induced relaxations. Contractile responses in the circular muscle of the mid colon could be attributed to α-adrenoceptors located on enteric cholinergic neurons. Stimulation of α1A-adrenoreceptors activates SKCa channels to cause smooth muscle relaxation, which constitutes a signaling pathway that shares similarities with P2Y1 receptors.

Excess Folic Acid Exposure Increases Uracil Misincorporation into DNA in a Tissue-Specific Manner in a Mouse Model of Reduced Methionine Synthase Expression

BackgroundFolate and vitamin B12 (B12) are cofactors in folate-mediated 1-carbon metabolism (FOCM), a metabolic network that supports synthesis of nucleotides (including thymidylate [dTMP]) and methionine. FOCM impairments such as a deficiency or imbalance of cofactors can perturb dTMP synthesis, causing uracil misincorporation into DNA. ObjectiveThe purpose of this study was to determine how reduced expression of the B12-dependent enzyme methionine synthase (MTR) and excess dietary folic acid interact to affect folate distribution and markers of genome stability in mouse tissues. MethodsHeterozygous Mtr knockout mice (Mtr+/–) model the FOCM-specific effects of B12 deficiency. Folate accumulation and vitamer distribution, genomic uracil concentrations, and phosphorylated histone H2AX (γH2AX) immunostaining were measured in male Mtr+/+ and Mtr+/− mice weaned to either a folate-sufficient control (C) diet (2 mg/kg folic acid) or a high folic acid (HFA) diet (20 mg/kg folic acid) for 7 wk. ResultsExposure to the HFA diet led to tissue-specific patterns of folate accumulation, with plasma, colon, kidney, and skeletal muscle exhibiting increased folate concentrations compared with control. Liver total folate did not differ. Although unmetabolized folic acid (UMFA) increased 10-fold in mouse plasma with HFA diet, UMFA accounted for <0.2% of total folate in liver and colon tissue. Exposure to HFA diet resulted in a shift in folate distribution in colon tissue with higher 5-methyl-THF and lower formyl-THF than in control mice. Mtr heterozygosity did not impact folate accumulation or distribution in any tissue. Mice on HFA diet exhibited higher uracil in genomic DNA and γH2AX foci in colon. Similar differences were not seen in liver. ConclusionsThis study demonstrates that folic acid, even when consumed at high doses, does not meaningfully accumulate in mouse tissues, although high-dose folic acid shifts folate distribution and increases uracil accumulation in genomic DNA in colon tissue.

Ex Vivo Study of Colon Health, Contractility and Innervation in Male and Female Rats after Regular Exposure to Instant Cascara Beverage.

Instant Cascara (IC) is a sustainable beverage made from dried coffee cherry pulp, a by-product of coffee processing. It is rich in nutrients and bioactive compounds and has a high concentration of antioxidants. This study explored the impact of regular IC consumption on colonic motor function and innervation. Over a period of 4 weeks, male and female healthy rats were given drinking water containing 10 mg/mL of IC. Thereafter, colon samples were obtained to evaluate the longitudinal (LM) and circular (CM) smooth muscle contractile response to acetylcholine (ACh) and electrical field stimulation (EFS) in an organ bath, before and after atropine administration (10-6 M). Histological and immunohistochemical analyses assessed colon damage, muscle thickness, and immunoreactivity to substance P (SP) and neuronal nitric oxide synthase (nNOS). ACh and EFS induced similar responses across groups, but the CM response to EFS was greater in females compared with males, despite their lower body weight. Atropine completely blocked the response to ACh but only partially antagonized the neural response to EFS, particularly that of CM in females treated with IC, which had a greater liquid intake than those exposed to water. However, in the myenteric ganglia, no statistically significant differences were observed in SP or nNOS. Our results suggest that regular IC exposure may enhance specific neural pathway functions, particularly in females, possibly due to their increased IC consumption.

From diverticulosis to complicated diverticular disease: Progression of myogenic alterations and oxidative imbalance.

The natural history and pathophysiology of diverticular disease (DD) are still uncertain. An ex-vivo human complicated DD (cDD) model has recently shown a predominant transmural oxidative imbalance. The present study aims to evaluate whether the previously described alterations may precede the symptomatic form of the disease. Colonic surgical samples obtained from patients with asymptomatic diverticulosis (DIV), complicated DD, and controls were systematically and detailed morphologically and molecularly analyzed. Therefore, histologic, histomorphometric, immunohistochemical evaluation, and gene and protein expression analysis were performed to characterize colonic muscle changes and evaluate chronic inflammation, oxidative imbalance, and hypoxia. Functional muscle activity was tested on strips and isolated cells in response to contractile and relaxant agents. Compared with controls, DD showed a marketed increase in muscle layer thickness, smooth muscle cell syncytium disarray, and increased interstitial fibrosis; moreover, the observed features were more evident in the cDD group. These changes mainly affected longitudinal muscle and were associated with altered contraction-relaxation dynamics and fibrogenic switch of smooth muscle cells. Chronic lymphoplasmacytic inflammation was primarily evident in the mucosa and spared the muscle. A transmural increase in carbonylated and nitrated proteins, with loss of antioxidant molecules, characterized both stages of DD, suggesting early oxidative stress probably triggered by recurrent ischemic events, more pronounced in cDD, where HIF-1 was detected in both muscle and mucosa. The different DD clinical scenarios are part of a progressive process, with oxidative imbalance representing a new target in the management of DD.

Protective Efficacy of the Epitope-Conjugated Antigen N-Tc52/TSkb20 in Mitigating Trypanosoma cruzi Infection through CD8+ T-Cells and IFNγ Responses.

Chagas disease, caused by the protozoan Trypanosoma cruzi, remains a major public health challenge affecting millions in Latin America and worldwide. Although significant progress has been made in vector control, no vaccine exists to prevent infection or mitigate disease pathogenesis. We developed a rationally designed chimeric protein vaccine, N-Tc52/TSkb20, incorporating immunodominant epitopes from two T. cruzi antigens, the amino-terminal portion of Tc52 and the TSkb20 epitope derived from trans-sialidase. The objectives of this study were to construct and characterize the antigen and evaluate its protective potential in an immunoprophylactic murine model of T. cruzi infection. The N-Tc52/TSkb20 protein was recombinantly expressed in E. coli and its identity was confirmed using mass spectrometry and Western blotting. Immunization with the chimeric protein significantly controlled parasitemia and reduced the heart, colon, and skeletal muscle parasite burdens compared to non-vaccinated mice. Protection was superior to vaccination with the individual parental antigen components. Mechanistically, the vaccine induced potent CD8+ T-cell and IFNγ responses against the incorporated epitopes and a protective IgG antibody profile. A relatively low IL-10 response favored early parasite control. These results validate the promising multi-epitope approach and support the continued development of this type of rational vaccine design strategy against Chagas disease.

The mitochondrial multi-omic response to exercise training across rat tissues

Mitochondria have diverse functions critical to whole-body metabolic homeostasis. Endurance training alters mitochondrial activity, but systematic characterization of these adaptations is lacking. Here, the Molecular Transducers of Physical Activity Consortium mapped the temporal, multi-omic changes in mitochondrial analytes across 19 tissues in male and female rats trained for 1, 2, 4, or 8weeks. Training elicited substantial changes in the adrenal gland, brown adipose, colon, heart, and skeletal muscle. The colon showed non-linear response dynamics, whereas mitochondrial pathways were downregulated in brown adipose and adrenal tissues. Protein acetylation increased in the liver, with a shift in lipid metabolism, whereas oxidative proteins increased in striated muscles. Exercise-upregulated networks were downregulated in human diabetes andcirrhosis. Knockdown of the central network protein 17-beta-hydroxysteroid dehydrogenase 10 (HSD17B10) elevated oxygen consumption, indicative of metabolic stress. We provide a multi-omic, multi-tissue, temporal atlas of the mitochondrial response to exercise training and identify candidates linked to mitochondrial dysfunction.

Integrated meta-omics reveals the regulatory landscape involved in lipid metabolism between pig breeds

BackgroundDomesticated pigs serve as an ideal animal model for biomedical research and also provide the majority of meat for human consumption in China. Porcine intramuscular fat content associates with human health and diseases and is essential in pork quality. The molecular mechanisms controlling lipid metabolism and intramuscular fat accretion across tissues in pigs, and how these changes in response to pig breeds, remain largely unknown.ResultsWe surveyed the tissue-resident cell types of the porcine jejunum, colon, liver, and longissimus dorsi muscle between Lantang and Landrace breeds by single-cell RNA sequencing. Combining lipidomics and metagenomics approaches, we also characterized gene signatures and determined key discriminating markers of lipid digestibility, absorption, conversion, and deposition across tissues in two pig breeds. In Landrace, lean-meat swine mainly exhibited breed-specific advantages in lipid absorption and oxidation for energy supply in small and large intestinal epitheliums, nascent high-density lipoprotein synthesis for reverse cholesterol transport in enterocytes and hepatocytes, bile acid formation, and secretion for fat emulsification in hepatocytes, as well as intestinal-microbiota gene expression involved in lipid accumulation product. In Lantang, obese-meat swine showed a higher synthesis capacity of chylomicrons responsible for high serum triacylglycerol levels in small intestinal epitheliums, the predominant characteristics of lipid absorption in muscle tissue, and greater intramuscular adipcytogenesis potentials from muscular fibro-adipogenic progenitor subpopulation.ConclusionsThe findings enhanced our understanding of the cellular biology of lipid metabolism and opened new avenues to improve animal production and human diseases.D7xkEMpXE5aNHjWuhXhcDpVideo

Effect of the Flavonoid Rutin on the Modulation of the Myenteric Plexuses in an Experimental Model of Parkinson's Disease.

Recent discoveries have shown that enteric glial cells play an important role in different neurodegenerative disorders, such as Parkinson's disease (PD), which is characterized by motor dysfunctions caused by the progressive loss of dopaminergic neurons in the substance nigra pars compacta and non-motor symptoms including gastrointestinal dysfunction. In this study, we investigated the modulatory effects of the flavonoid rutin on the behavior and myenteric plexuses in a PD animal model and the response of enteric glia. Adult male Wistar rats were submitted to stereotaxic injection with 6-hydroxydopamine or saline, and they were untreated or treated with rutin (10 mg/kg) for 14 days. The ileum was collected to analyze tissue reactivity and immunohistochemistry for neurons (HuC/HuD) and enteric glial cells (S100β) in the myenteric plexuses. Behavioral tests demonstrated that treatment with rutin improved the motor capacity of parkinsonian animals and improved intestinal transit without interfering with the cell population; rutin treatment modulated the reactivity of the ileal musculature through muscarinic activation, reducing relaxation through the signaling pathway of nitric oxide donors, and increased the longitudinal contractility of the colon musculature in parkinsonian animals. Rutin revealed modulatory activities on the myenteric plexus, bringing relevant answers regarding the effect of the flavonoid in this system and the potential application of PD adjuvant treatment.

Pathological changes in the muscular tissue of the colon in diverticular disease

Comparative analysis of clinical data and structural characteristics of the colonic muscular tissue in patients with different course of DD and without colonic diverticula to identify morphological predictors of a complicated DD. A comparative analysis of clinical data, pathomorphological and ultrastructural changes of the colonic musculature in the surgical material from 68 patients undergoing left-sided hemicolectomy was carried out. The operative material of 37 patients with complicated course of DD, 19 with uncomplicated course of DD and 12 without diverticula was analyzed. In men, this disease occurs at a younger age than in women (Median age of men 49 (39.5; 61) years, women 66.5 (58; 81) years; U=178, p<0.001). It was shown that the area occupied by connective tissue fibres in the colonic musculature in patients with a complicated DD was 5 times greater (15%) than in observations with an uncomplicated DD (3%) and 50 times greater than in cases without colonic diverticula (0.3%; p<0.001). The present study demonstrates age- and sex-specific features of DD, as well as significant differences in the prevalence of fibrosis of the colonic musculature, which can be considered as a potential predictor of a complicated course of DD.

Modulation of Tau Expression in the Colonic Muscle Layer of a Rat Model with Opioid-Induced Constipation

Modulation of Tau Expression in the Colonic Muscle Layer of a Rat Model with Opioid-Induced Constipation

L-Fucose promotes enteric nervous system regeneration in type 1 diabetic mice by inhibiting SMAD2 signaling pathway in enteric neural precursor cells

BackgroundDiabetes can lead to extensive damage to the enteric nervous system (ENS), causing gastrointestinal motility disorders. However, there is currently a lack of effective treatments for diabetes-induced ENS damage. Enteric neural precursor cells (ENPCs) closely regulate the structural and functional integrity of the ENS. L-Fucose, is a dietary sugar that has been showed to effectively ameliorate central nervous system injuries, but its potential for ameliorating ENS damage and the involvement of ENPCs in this process remains uncertain.MethodsGenetically engineered mice were generated for lineage tracing of ENPCs in vivo. Using diabetic mice in vivo and high glucose-treated primary ENPCs in vitro, the effects of L-Fucose on the injured ENS and ENPCs was evaluated by assessing gastrointestinal motility, ENS structure, and the differentiation of ENPCs. The key signaling pathways in regulating neurogenesis and neural precursor cells properties, transforming growth factor-β (TGF-β) and its downstream signaling pathways were further examined to clarify the potential mechanism of L-Fucose on the injured ENS and ENPCs.ResultsL-Fucose improved gastrointestinal motility in diabetic mice, including increased defecation frequency (p < 0.05), reduced total gastrointestinal transmission time (p < 0.001) and bead expulsion time (p < 0.05), as well as enhanced spontaneous contractility and electric field stimulation-induced contraction response in isolated colonic muscle strips (p < 0.001). The decrease in the number of neurons and glial cells in the ENS of diabetic mice were reversed by L-Fucose treatment. More importantly, L-Fucose treatment significantly promoted the proportion of ENPCs differentiated into neurons and glial cells both in vitro and in vivo, accompanied by inhibiting SMAD2 phosphorylation.ConclusionsL-Fucose could promote neurogenesis and gliogenesis derived from ENPCs by inhibiting the SMAD2 signaling, thus facilitating ENS regeneration and gastrointestinal motility recovery in type 1 diabetic mice.7Zzihak_jncvcnfCNwCPXsVideo

Transplanted ENSCs form functional connections with intestinal smooth muscle and restore colonic motility in nNOS-deficient mice

BackgroundEnteric neuropathies, which result from abnormalities of the enteric nervous system, are associated with significant morbidity and high health-care costs, but current treatments are unsatisfactory. Cell-based therapy offers an innovative approach to replace the absent or abnormal enteric neurons and thereby restore gut function.MethodsEnteric neuronal stem cells (ENSCs) were isolated from the gastrointestinal tract of Wnt1-Cre;R26tdTomato mice and generated neurospheres (NS). NS transplants were performed via injection into the mid-colon mesenchyme of nNOS−/− mouse, a model of colonic dysmotility, using either 1 (n = 12) or 3 (n = 12) injections (30 NS per injection) targeted longitudinally 1–2 mm apart. Functional outcomes were assessed up to 6 weeks later using electromyography (EMG), electrical field stimulation (EFS), optogenetics, and by measuring colorectal motility.ResultsTransplanted ENSCs formed nitrergic neurons in the nNOS−/− recipient colon. Multiple injections of ENSCs resulted in a significantly larger area of coverage compared to single injection alone and were associated with a marked improvement in colonic function, demonstrated by (1) increased colonic muscle activity by EMG recording, (2) faster rectal bead expulsion, and (3) increased fecal pellet output in vivo. Organ bath studies revealed direct neuromuscular communication by optogenetic stimulation of channelrhodopsin-expressing ENSCs and restoration of smooth muscle relaxation in response to EFS.ConclusionsThese results demonstrate that transplanted ENSCs can form effective neuromuscular connections and improve colonic motor function in a model of colonic dysmotility, and additionally reveal that multiple sites of cell delivery led to an improved response, paving the way for optimized clinical trial design.

An Optogenetics-based Approach to Regulate Colonic Contractions by Modulating the Activity of the Interstitial Cells of Cajal in Mice.

The interstitial cells of Cajal (ICC) are pacemaker cells in the gastrointestinal (GI) tract. We examined whether the activity of ICC could be stimulated to control colonic contractions. An optogenetics-based mouse model in which the light-sensitive protein channelrhodopsin-2 (ChR2) was expressed was used to accomplish cell specific, direct stimulation of ICC. An inducible site-specific Cre-loxP recombination system was used to generate KitCreERT2/+;ROSAChR2(H134R)/tdTomato/+ mice in which ChR2(H134R), a variant of ChR2, was genetically expressed in ICC after tamoxifen administration. Genotyping and immunofluorescence analysis were performed to confirm gene fusion and expression. Isometric force recordings were performed to measure changes in contractions in the colonic muscle strips. ChR2 was specifically expressed in Kit-labeled ICC. The isometric force recordings showed that the contractions of the colonic muscle strips changed under 470 nm blue light. Light stimulation evoked premature low-frequency and high amplitude (LFHA) contractions and enhanced the frequency of the LFHA contractions. The light-evoked contractions were blocked by T16Ainh-A01, an antagonist of anoctamin 1 channels that are expressed selectively in ICC in colonic muscles. Our study demonstrates a potentially feasible approach to stimulate the activity of ICC by optogenetics. The colonic motor patterns of muscle strips, especially LFHA contractions, can be regulated by 470 nm light via ChR2, which is expressed in ICC.

Effect of deep needling "Tianshu" (ST25) on colonic motility in rats with slow transit constipation

To observe the effect of acupuncture of "Tianshu"(ST25) at different depths on colonic transportation function, expressions of colonic substance P (SP) and interstitial cells of Cajal (ICC) in rats with slow transit constipation (STC), so as to explore its mechanisms underlying improvement of STC．. Fifty male Wistar rats were selected and randomly divided into control，STC model，conventional acupuncture，deep needling group 1 and deep needling group 2 groups，with 10 rats in each group．The STC model was established by gavage of 1 mg/mL compound diphenoxylate suspension (10 mg/kg), once every other day for 21 days, and rats of the control group were given the same dose of distilled water by gavage．EA (2 Hz, 2 mA) was applied to "Tianshu"(ST25), with the acupuncture needle inserted to a depth of 3 mm for rats of the conventional acupuncture group, 4.5 mm for those of deep needling group 1, and 10 mm for those of the deep needling group 2. The acupuncture needle was twirled for 1 min, then retained for 15 min each time, once a day for 15 consecutive days．Following modeling, rats of the 4 groups and the control group received gavage of active carbon 2 mL (100 g/L) for observing the excretion time of the first black stool grain to assess the intestinal transit function. The colonic myoelectric activities (frequency and amplitude) were recorded by using BIOPAC multichannel physiograph. The immunoactivity of SP and c-kit (a transmembrane protein kinase for identification of ICC) of colonic musculature was detected by immunohistochemistry. Compared with the control group，the time of excretion of the first black stool grain, and the amplitude of colonic electromyogram (EMG) were significantly increased (P<0.01), while the frequency of EMG, expressions of SP and c-kit (ICC) were significantly decreased in the model group (P<0.01). In contrast to the model group, both deep needling group 1 and 2 had a decrease in the time of excretion of the first black stool grain, and amplitude of intestinal EMG, and an increase of frequency of intestinal EMG, and immunoactivity of SP and c-kit (P<0.01). The effect of deep needling 2 is superior to that of deep needling 1 in reducing the time of excretion of the first black stool grain (P<0.05), lowering the amplitude of EMG of the gut smooth muscle (P<0.05) and in increasing the frequency of EMG (P<0.05) and the expressions of SP and c-kit (P<0.05). No significant changes were found in the levels of frequency and amplitude of EMG, and expressions of SP and c-kit after routine needling in comparison with the model group (P>0.05), except the excretion time of the first black stool grain (P<0.05). Deep needling at ST25 at depth of 4.5 mm and 10 mm，especially at depth of 10 mm，has a significant effect in promoting gut motility to ameliorate constipation in rats with STC, which may be related to its function in up-regulating the expressions of SP and ICC activity.

Des nodules cutanés de la paroi abdominale révélant une pyelonéphrite xanthogranulomateuse

IntroductionXanthogranulomatous pyelonephritis is a chronic pyelonephritis characterized by an inflammatory granulomatous reaction that destroys the renal parenchyma. It is an uncommon entity. Diffuse inflammation has the potential to spread to nearby organs, especially the skin. ObservationA 73-year-old patient presented with a three-year history of painful and fistulized nodules on the abdominal wall. The results of abdominal computed tomography and magnetic resonance imaging revealed xanthogranulomatous pyelonephritis with extension to the skin, colon, and psoas muscle. The skin lesions were improved by a double antibiotic therapy. The patient was advised to have a radical left nephrectomy, but he refused surgery and was then lost to follow-up. ConclusionWe report an uncommon case of xanthogranulomatous pyelonephritis revealed by cutaneous nodules of the abdominal wall, with an extension toward the skin, the colon and the psoas muscle.

Retracted: PKC-delta and PKD activate MAPK signal pathway in mechano-transcription of colonic smooth muscle cells.

Retraction: [PKC-delta and PKD activate MAPK signal pathway in mechano-transcription of colonic smooth muscle cells, Z. Yang, K. He, T. Wang, et al. Neurogastroenterology & Motility 2023; e14623 (https://onlinelibrary.wiley.com/doi/full/10.1111/nmo.14623)]. The above article, published online on June 6, 2023 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the Journal Editor in Chief, Maura Corsetti, and John Wiley & Sons Ltd. The retraction has been agreed due to unat[1]tributed overlap between this article and the abstract published in Gastroenterology: Li F, Sarna SK and Shi XP. Roles of PKCs and PKD in Mechanotranscription in Colonic Smooth Muscle Cells: Inhibition of Mechanotranscription as a Potential Treatment for Motility Dysfunction in Obstructive Disorders. In: 2012 Digestive Disease Week Abstract Supplement; May 19-22, San Diego, CA. Abstract 120 (https://www.gastrojournal.org/article/S0016-5085(12)60115-2/pdf).

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

BackgroundElectroacupuncture (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 MethodsC57BL/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. Results1) 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. ConclusionsHEA 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.

Neuroprotection by Abdominal Ultrasound in Lipopolysaccharide-Induced Systemic Inflammation.

Systemic inflammation is associated with intestinal inflammation and neuroinflammation by imbalancing the gut-brain axis. Low-intensity pulsed ultrasound (LIPUS) has neuroprotective and anti-inflammatory effects. This study explored LIPUS's neuroprotective effects against lipopolysaccharide (LPS)-induced neuroinflammation through transabdominal stimulation. Male C57BL/6J mice were intraperitoneally injected with LPS (0.75 mg/kg) daily for seven days, and abdominal LIPUS was applied to the abdominal area for 15 min/day during the last six days. One day after the last LIPUS treatment, biological samples were collected for microscopic and immunohistochemical analysis. Histological examination showed that LPS administration leads to tissue damage in the colon and brain. Transabdominal LIPUS stimulation attenuated colonic damage, reducing histological score, colonic muscle thickness, and villi shortening. Furthermore, abdominal LIPUS reduced hippocampal microglial activation (labeled by ionized calcium-binding adaptor molecule-1 [Iba-1]) and neuronal cell loss (labeled by microtubule-associated protein 2 [MAP2]). Moreover, abdominal LIPUS attenuated the number of apoptotic cells in the hippocampus and cortex. Altogether, our results indicate that abdominal LIPUS stimulation attenuates LPS-induced colonic inflammation and neuroinflammation. These findings provide new insights into the treatment strategy for neuroinflammation-related brain disorders and may facilitate method development through the gut-brain axis pathway.