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International Journal of Molecular... Jan 2024The brain-gut axis has been identified as an important contributor to the physiopathology of Parkinson's disease. In this pathology, inflammation is thought to be driven... (Review)
Review
The brain-gut axis has been identified as an important contributor to the physiopathology of Parkinson's disease. In this pathology, inflammation is thought to be driven by the damage caused by aggregation of α-synuclein in the brain. Interestingly, the Braak's theory proposes that α-synuclein misfolding may originate in the gut and spread in a "prion-like" manner through the vagus nerve into the central nervous system. In the enteric nervous system, enteric glial cells are the most abundant cellular component. Several studies have evaluated their role in Parkinson's disease. Using samples obtained from patients, cell cultures, or animal models, the studies with specific antibodies to label enteric glial cells (GFAP, Sox-10, and S100β) seem to indicate that activation and reactive gliosis are associated to the neurodegeneration produced by Parkinson's disease in the enteric nervous system. Of interest, Toll-like receptors, which are expressed on enteric glial cells, participate in the triggering of immune/inflammatory responses, in the maintenance of intestinal barrier integrity and in the configuration of gut microbiota; thus, these receptors might contribute to Parkinson's disease. External factors like stress also seem to be relevant in its pathogenesis. Some authors have studied ways to reverse changes in EGCs with interventions such as administration of Tryptophan-2,3-dioxygenase inhibitors, nutraceuticals, or physical exercise. Some researchers point out that beyond being activated during the disease, enteric glial cells may contribute to the development of synucleinopathies. Thus, it is still necessary to further study these cells and their role in Parkinson's disease.
Topics: Animals; Humans; Parkinson Disease; alpha-Synuclein; Brain; Inflammation; Neuroglia; Enteric Nervous System
PubMed: 38279293
DOI: 10.3390/ijms25021294 -
The American Journal of Surgical... Jul 2024Isolated hypoganglionosis (IHG) is histologically characterized by small numbers of myenteric ganglion cells and small myenteric ganglia; however, no numerical...
Isolated hypoganglionosis (IHG) is histologically characterized by small numbers of myenteric ganglion cells and small myenteric ganglia; however, no numerical diagnostic criteria for IHG have been established. Therefore, this study aimed to develop quantitative pathologic criteria for IHG. We evaluated 160 resected intestinal tissue specimens from 29 pediatric autopsies and 10 IHG cases. These specimens were obtained from the jejunum, ileum, ascending colon, transverse colon, and rectum. Morphologic features of the myenteric ganglion cells and myenteric ganglia were quantified and analyzed in digitized HuC/HuD-immunostained and CD56-immunostained sections, respectively. Quantitative criteria were developed with a scoring system that used parameters with the area under the receiver operating characteristic curve (AUC) values >0.7 and sensitivity and specificity exceeding 70%. The selected parameters were the number of myenteric ganglion cells per cm and the number of myenteric ganglia with an area >2500 µm 2 per cm. The score for each parameter ranged from -1 to 2, and the total score of the scoring system ranged from -2 to 4. With a cutoff value of ≥2 (AUC, 0.98; 95% CI: 0.96-1.00), the scoring system had a sensitivity of 96% (95% CI: 0.82-1.00) and a specificity of 99% (95% CI: 0.95-1.00). We devised a novel pathologic criterion based on the quantification of the number of myenteric ganglion cells and ganglia. Furthermore, this criterion showed high diagnostic accuracy and could lead to a definitive diagnosis of IHG in clinical practice.
Topics: Humans; Male; Female; Myenteric Plexus; Infant; Child, Preschool; Child; Predictive Value of Tests; Immunohistochemistry; Infant, Newborn; Autopsy; Biomarkers; ROC Curve; Adolescent; Cell Count; Area Under Curve
PubMed: 38726836
DOI: 10.1097/PAS.0000000000002243 -
Histochemistry and Cell Biology Nov 2023Short bowel syndrome (SBS) is a severe, life-threatening condition and one of the leading causes of intestinal failure in children. Here we were interested in changes in...
Short bowel syndrome (SBS) is a severe, life-threatening condition and one of the leading causes of intestinal failure in children. Here we were interested in changes in muscle layers and especially in the myenteric plexus of the enteric nervous system (ENS) of the small bowel in the context of intestinal adaptation. Twelve rats underwent a massive resection of the small intestine to induce SBS. Sham laparotomy without small bowel transection was performed in 10 rats. Two weeks after surgery, the remaining jejunum and ileum were harvested and studied. Samples of human small bowel were obtained from patients who underwent resection of small bowel segments due to a medical indication. Morphological changes in the muscle layers and the expression of nestin, a marker for neuronal plasticity, were studied. Following SBS, muscle tissue increases significantly in both parts of the small bowel, i.e., jejunum and ileum. The leading pathophysiological mechanism of these changes is hypertrophy. Additionally, we observed an increased nestin expression in the myenteric plexus in the remaining bowel with SBS. Our human data also showed that in patients with SBS, the proportion of stem cells in the myenteric plexus had risen by more than twofold. Our findings suggest that the ENS is tightly connected to changes in intestinal muscle layers and is critically involved in the process of intestinal adaptation to SBS.
Topics: Child; Rats; Humans; Animals; Short Bowel Syndrome; Nestin; Rats, Sprague-Dawley; Ileum; Disease Models, Animal; Neuronal Plasticity
PubMed: 37395792
DOI: 10.1007/s00418-023-02214-4 -
Cureus Sep 2023Achalasia, a neurodegenerative disease caused by the progressive destruction of ganglion cells in the myenteric plexus, is accompanied by incomplete relaxation of the... (Review)
Review
Comparison of the Clinical Efficacy, Safety, and Postoperative Outcomes Between Peroral Esophageal Myotomy and Laparoscopic Heller's Myotomy With Fundoplication: A Systematic Review.
Achalasia, a neurodegenerative disease caused by the progressive destruction of ganglion cells in the myenteric plexus, is accompanied by incomplete relaxation of the lower esophageal sphincter. Laparoscopic Heller's myotomy (LHM) coupled with fundoplication has been the gold standard procedure for achalasia. Peroral esophageal myotomy (POEM) has recently gained popularity as it is minimally invasive, has fewer adverse events, and has excellent short-term outcomes. So, we aimed to compare the clinical efficacy, safety, and postoperative outcomes between LHM and POEM. We did a systematic review by following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines for 2020 and exploring research databases such as PUBMED and PMC Central, Google Scholar, and Research Gate. After appropriate screenings, articles relevant to the review were scrutinized based on the eligibility criteria. Quality assessment tools such as the Newcastle-Ottawa Scale (NOS) and the assessment of multiple systematic reviews (AMSTAR) were used to finalize the articles. A total of 11 articles (seven observational studies, two RCTs, and two systematic reviews) were included in the review after a quality check. The study included 2127 patients, classified into 981 for POEM and 1146 for LHM, who had undergone treatment for achalasia. Most of the studies had a follow-up of ≤ two years. Comparing efficacy, POEM had similar results to LHM in terms of Eckardt scores. However, abnormal DeMeester scores were found in POEM. Adverse events were significantly higher in LHM when compared to POEM in terms of safety. Peroral esophageal myotomy also stood out as having a shorter procedure time, a shorter hospital stay, and lesser odds of being a clinical failure. As for postoperative outcomes, despite treatment with proton pump inhibitors, LHM was more effective in preventing the development of esophagitis compared to POEM due to partial fundoplication.Postoperative reflux and the development of esophagitis remain certain with POEM and need to be followed up with more studies with longer follow-ups. However, POEM still stands as a better choice compared to LHM in terms of efficacy and safety.
PubMed: 37818506
DOI: 10.7759/cureus.44877 -
Journal of Neuroscience Methods Jul 2024The enteric nervous system (ENS) is comprised of neurons, glia, and neural progenitor cells that regulate essential gastrointestinal functions. Advances in...
BACKGROUND
The enteric nervous system (ENS) is comprised of neurons, glia, and neural progenitor cells that regulate essential gastrointestinal functions. Advances in high-efficiency enteric neuron culture would facilitate discoveries surrounding ENS regulatory processes, pathophysiology, and therapeutics.
NEW METHOD
Development of a simple, robust, one-step method to culture murine enteric neurospheres in a 3D matrix that supports neural growth and differentiation.
RESULTS
Myenteric plexus cells isolated from the entire length of adult murine small intestine formed ≥3000 neurospheres within 7 days. Matrigel-embedded neurospheres exhibited abundant neural stem and progenitor cells expressing Sox2, Sox10 and Msi1 by day 4. By day 5, neural progenitor cell marker Nestin appeared in the periphery of neurospheres prior to differentiation. Neurospheres produced extensive neurons and neurites, confirmed by Tubulin beta III, PGP9.5, HuD/C, and NeuN immunofluorescence, including neural subtypes Calretinin, ChAT, and nNOS following 8 days of differentiation. Individual neurons within and external to neurospheres generated depolarization induced action potentials which were inhibited in the presence of sodium channel blocker, Tetrodotoxin. Differentiated neurospheres also contained a limited number of glia and endothelial cells.
COMPARISON WITH EXISTING METHODS
This novel one-step neurosphere growth and differentiation culture system, in 3D format (in the presence of GDNF, EGF, and FGF2), allows for ∼2-fold increase in neurosphere count in the derivation of enteric neurons with measurable action potentials.
CONCLUSION
Our method describes a novel, robust 3D culture of electrophysiologically active enteric neurons from adult myenteric neural stem and progenitor cells.
Topics: Animals; Myenteric Plexus; Neurons; Cell Culture Techniques; Neural Stem Cells; Cell Differentiation; Mice; Mice, Inbred C57BL; Cells, Cultured; Action Potentials; Laminin; Drug Combinations; Proteoglycans; Male; Neurogenesis; Collagen
PubMed: 38670535
DOI: 10.1016/j.jneumeth.2024.110144 -
Carcinogenesis Dec 2023EphB6 belongs to the receptor tyrosine kinase, whose low expression is associated with shorter survival of colorectal cancer (CRC) patients. But the role and mechanism...
EphB6 belongs to the receptor tyrosine kinase, whose low expression is associated with shorter survival of colorectal cancer (CRC) patients. But the role and mechanism of EphB6 in the progression of CRC need further study. In addition, EphB6 was mainly expressed in intestinal neurons. But how EphB6 is involved in functions of intestinal neurons has not been known. In our study, we constructed a mouse xenograft model of CRC by injecting CMT93 cells into the rectum of EphB6-deficient mice. We found that the deletion of EphB6 in mice promoted tumor growth of CMT93 cells in a xenograft model of CRC, which was independent of changes in the gut microbiota. Interestingly, inhibition of intestinal neurons by injecting botulinum toxin A into rectum of EphB6-deficient mice could eliminate the promotive effect of EphB6 deficiency on tumor growth in the xenograft model of CRC. Mechanically, the deletion of EphB6 in mice promoted the tumor growth in CRC by increasing GABA in the tumor microenvironment. Furthermore, EphB6 deficiency in mice increased the expression of synaptosomal-associated protein 25 in the intestinal myenteric plexus, which mediated the release of GABA. Our study concluded that EphB6 knockout in mice promotes tumor growth of CMT93 cells in a xenograft model of CRC by modulating GABA release. Our study found a new regulating mechanism of EphB6 on the tumor progression in CRC that is dependent on intestinal neurons.
Topics: Humans; Animals; Mice; Cell Communication; Colorectal Neoplasms; Intestines; Neurons; gamma-Aminobutyric Acid; Tumor Microenvironment
PubMed: 37294054
DOI: 10.1093/carcin/bgad041 -
Histochemistry and Cell Biology Oct 2023This study aimed to investigate the distal colon myenteric plexus and enteric glial cells (EGCs) in P2X7 receptor-deficient (P2X7-/-) animals after the induction of...
This study aimed to investigate the distal colon myenteric plexus and enteric glial cells (EGCs) in P2X7 receptor-deficient (P2X7-/-) animals after the induction of experimental ulcerative colitis. 2,4,6-Trinitrobenzene sulfonic acid (TNBS) was injected into the distal colon of C57BL/6 (WT) and P2X7 receptor gene-deficient (P2X7-/-, KO) animals. Distal colon tissues in the WT and KO groups were analyzed 24 h and 4 days after administration. The tissues were analyzed by double immunofluorescence of the P2X7 receptor with neuronal nitric oxide synthase (nNOS)-immunoreactive (ir), choline acetyltransferase (ChAT)-ir, and PGP9.5 (pan neuronal)-ir, and their morphology was assessed by histology. The quantitative analysis revealed 13.9% and 7.1% decreases in the number of P2X7 receptor-immunoreactive (ir) per ganglion in the 24 h-WT/colitis and 4 day-WT/colitis groups, respectively. No reduction in the number of nNOS-ir, choline ChAT-ir, and PGP9.5-ir neurons per ganglion was observed in the 4 day-KO/colitis group. In addition, a reduction of 19.3% in the number of GFAP (glial fibrillary acidic protein)-expressing cells per ganglion was found in the 24 h-WT/colitis group, and a 19% increase in the number of these cells was detected in the 4 day-WT/colitis group. No profile area changes in neurons were observed in the 24 h-WT and 24 h-KO groups. The 4 day-WT/colitis and 4 day-KO/colitis groups showed increases in the profile neuronal areas of nNOS, ChAT, and PGP9.5. The histological analysis showed hyperemia, edema, or cellular infiltration in the 24 h-WT/colitis and 4 day-WT/colitis groups. Edema was observed in the 4 day-KO/colitis group, which showed no histological changes compared with the 24 h-KO/colitis group. We concluded that ulcerative colitis differentially affected the neuronal classes in the WT and KO animals, demonstrating the potential participation and neuroprotective effect of the P2X7 receptor in enteric neurons in inflammatory bowel disease.
Topics: Mice; Animals; Colitis, Ulcerative; Receptors, Purinergic P2X7; Mice, Inbred C57BL; Myenteric Plexus; Neurons; Colitis
PubMed: 37306742
DOI: 10.1007/s00418-023-02208-2 -
Microbiological Research Nov 2023The gut microbiota plays a critical role in the appropriate development and maintenance of the enteric nervous system (ENS). Esophageal achalasia (EA) is a rare motility...
OBJECTIVE
The gut microbiota plays a critical role in the appropriate development and maintenance of the enteric nervous system (ENS). Esophageal achalasia (EA) is a rare motility disorder characterized by the selective degeneration of inhibitory neurons in the esophageal myenteric plexus. This study aimed to evaluate the composition of the esophageal microbiota in achalasia and explore the potential microbial mechanisms involved in its pathogenesis.
DESIGN
The lower esophageal mucosal microbiota was analyzed in patients with achalasia and control participants using 16 S rRNA sequencing. The association between the esophageal microbiota and achalasia was validated by inducing esophageal dysbiosis in C57BL/10 J and C57BL/10ScNJ (TLR4KO) mice via chronic exposure to ampicillin sodium in their drinking water.
RESULTS
The esophageal microbiota in EA patients had lower diversity and a predominance of Gram-negative bacteria (Type II microbiota) compared to that in the healthy controls. Additionally, the relative abundance of Rhodobacter decreased significantly in patients with achalasia, which correlated with an enrichment of lipopolysaccharide (LPS) biosynthesis based on the COG database. Antibiotic-treated mice showed an esophageal microbiota characterized by increased abundance of Gram-negative bacteria (Type II microbiome), decreased abundance of Rhodobacter, and enriched LPS biosynthesis. Compared to the control and TLR4KO mice, the antibiotic-treated wild-type mice had higher LES resting pressure, increased LES contraction rate after carbachol stimulation, and decreased relaxation response to L-arginine. Moreover, the number of myenteric neurons decreased, while the number of lamina propria macrophages (LpMs) increased after antibiotic exposure. Furthermore, the TLR4-MYD88-NF-κB pathway was up-regulated, and the production of TNF-α, IL-1β, and IL-6 increased in the antibiotic-treated mice.
CONCLUSIONS
Patients with achalasia exhibit esophageal dysbiosis, which may induce aberrant esophageal motility.
Topics: Mice; Animals; Esophageal Achalasia; Lipopolysaccharides; Dysbiosis; Mice, Inbred C57BL; Neurons; Gastrointestinal Microbiome; Anti-Bacterial Agents
PubMed: 37574627
DOI: 10.1016/j.micres.2023.127470 -
Frontiers in Pharmacology 2024Vincristine (VCR), an antineoplastic drug, induces peripheral neuropathy characterized by nerve damage, limiting its use and reducing the quality of life of patients....
Vincristine (VCR), an antineoplastic drug, induces peripheral neuropathy characterized by nerve damage, limiting its use and reducing the quality of life of patients. VCR causes myenteric neuron damage, inhibits gastrointestinal motility, and results in constipation or paralytic ileus in patients. Oxytocin (OT) is an endogenous neuropeptide produced by the enteric nerve system, which regulates gastrointestinal motility and exerts neuroprotective effects. This study aimed to investigate whether OT can improve VCR-induced gastrointestinal dysmotility and evaluate the underlying mechanism. Mice were injected either with saline or VCR (0.1 mg/kg/d, i. p.) for 14 days, and OT (0.1 mg/kg/d, i.p.) was applied 1 h before each VCR injection. Gastrointestinal transit and the contractile activity of the isolated colonic segments were assessed. The concentration of OT in plasma was measured using ELISA. Immunofluorescence staining was performed to analyze myenteric neurons and reactive oxygen species (ROS) levels. Furthermore, the indicators of oxidative stress were detected. The protein expressions of Nrf2, ERK1/2, P-ERK1/2, p38, and P-p38 in the colon were tested using Western blot. VCR reduced gastrointestinal transit and the responses of isolated colonic segments to electrical field stimulation and decreased the amount of neurons. Furthermore, VCR reduced neuronal nitric oxide synthase and choline acetyltransferase immunopositive neurons in the colonic myenteric nerve plexus. VCR increased the concentration of OT in plasma. Exogenous OT pretreatment ameliorated the inhibition of gastrointestinal motility and the injury of myenteric neurons caused by VCR. OT pretreatment also prevented the decrease of superoxide dismutase activity, glutathione content, total antioxidative capacity, and Nrf2 expression, the increase of ROS levels, and the phosphorylation of ERK1/2 and p38 MAPK following VCR treatment. Our results suggest that OT pretreatment can protect enteric neurons from VCR-induced injury by inhibiting oxidative stress and MAPK pathways (ERK1/2, p38). This may be the underlying mechanism by which it alleviates gastrointestinal dysmotility.
PubMed: 38655179
DOI: 10.3389/fphar.2024.1270612 -
Anatomia, Histologia, Embryologia Nov 2023Rabbit large intestine has a segment-specific morphology and motility. However, the morphological features of the myenteric plexus, which controls intestinal motility,...
Rabbit large intestine has a segment-specific morphology and motility. However, the morphological features of the myenteric plexus, which controls intestinal motility, have not been characterized in each large intestinal segment. We investigated the myenteric plexus morphology in the rabbit large intestine using protein gene product 9.5 immunohistochemistry in whole-mount preparations. The tenial part of the first and second segments of the proximal colon had the most well developed myenteric plexus, while the caecum had the least. These findings suggest different neuronal control over the motility of each intestinal segment, thereby providing a fundamental understanding of the rabbit enteric nervous system.
Topics: Rabbits; Animals; Myenteric Plexus; Intestine, Large; Intestines; Enteric Nervous System; Neurons
PubMed: 37458241
DOI: 10.1111/ahe.12950