scholarly journals A9 DORSAL ROOT GANGLIA NEURONAL RESPONSES AND SUBSTANCE P PRODUCTION ARE HIGHER IN MALE MICE

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 10-11
Author(s):  
J Pujo ◽  
G De Palma ◽  
J Lu ◽  
S M Collins ◽  
P Bercik
Keyword(s):  
Abdominal Pain ◽  
Substance P ◽  
Gut Microbiota ◽  
Sensory Neurons ◽  
Dorsal Root ◽  
Neuronal Response ◽  
Neuronal Responses ◽  
Visceral Sensitivity ◽  
Germ Free

Abstract Background Abdominal pain is a common complaint in patients with chronic gastrointestinal disorders. Accumulating evidence suggests that gut microbiota is an important determinant of gut function, including visceral sensitivity. Germ-free (GF) mice have been shown to display visceral hypersensitivity, which normalizes after colonization. Sex also appears to play a key role in visceral sensitivity, as women report more abdominal pain than men. Thus, both gut bacteria and sex are important in the regulation of gut nociception, but the underlying mechanisms remain poorly understood. Aims To investigate the role of gut microbiota and sex in abdominal pain. Methods We used primary cultures of sensory neurons from dorsal root ganglia (DRG) of female and male conventionally raised (SPF) or germ-free (GF) mice (7–18 weeks old). To study the visceral afferent activity in vitro, calcium mobilization in DRG sensory neurons was measured by inverted fluorescence microscope using a fluorescent calcium probe Fluo-4 (1mM). Two parameters were considered i) the percentage of responding neurons ii) the intensity of the neuronal response. First, DRG sensory neurons were stimulated by a TRPV1 agonist capsaicin (12.5nM, 125nM and 1.25µM) or by a mixture of G-protein coupled receptors agonist (GPCR: bradykinin, histamine and serotonin; 1µM, 10µM and 100µM). We next measured the neuronal production of substance P and calcitonin gene-related peptide (CGRP), two neuropeptides associated with nociception, in response to capsaicin (1.25µM) or GPCR agonists (100µM) by ELISA and EIA, respectively. Results The percentage of neurons responding to capsaicin and GPCR agonists was similar in male and female SPF and GF mice. However, the intensity of the neuronal response was higher in SPF male compared to SPF female in response to capsaicin (125nM: p=0.0336; 1.25µM: p=0.033) but not to GPCR agonists. Neuronal activation was similar in GF and SPF mice of both sexes after administration of capsaicin or GPCR agonists. Furthermore, substance P and CGRP production by sensory neurons induced by capsaicin or GPCR agonists was similar in SPF and GF mice, regardless of sex. However, while the response to capsaicin was similar, the GPCR agonists-induced production of substance P was higher in SPF male mice compared to SPF females (p=0.003). The GPCR agonists-induced production of CGRP was similar in SPF male and female mice. Conclusions Our data suggest that at the level of DRG neurons, the absence of gut microbiota does not predispose to visceral hypersensitivity. The intensity of DRG neuronal responses to capsaicin and the GPCR agonists-induced production of substance P are higher in male compared to female mice, in contrast to previously published studies in various models of acute and chronic pain. Further studies are thus needed to investigate the role of sex in visceral sensitivity. Funding Agencies CIHR

scholarly journals A122 THE INFLUENCE OF SEX AND THE GUT MICROBIOTA ON VISCERAL PAIN SENSITIVITY IN MICE

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 142-143
Author(s):  
J Pujo ◽  
G De Palma ◽  
J Lu ◽  
S M Collins ◽  
P Bercik
Keyword(s):  
Abdominal Pain ◽  
Gut Microbiota ◽  
Sensory Neurons ◽  
Neuronal Response ◽  
Calcium Mobilization ◽  
Visceral Sensitivity ◽  
Drg Neurons ◽  
E Coli ◽  
Germ Free

Abstract Background Abdominal pain is a common complaint in patients with chronic gastrointestinal disorders. Its treatment is of limited efficacy as the pathophysiology is largely unknown. Accumulating evidence suggests that gut microbiota is an important determinant of gut function, including visceral sensitivity. Germ-free (GF) mice have been shown to have altered pain signaling, which normalizes after colonization. Sex also appears to play a key role in visceral sensitivity, as abdominal pain is diagnosed predominantly in female patients. Thus, both gut bacteria and sex are important in the regulation of gut nociception, but the underlying mechanisms remain poorly understood. Aims To investigate the role of gut microbiota and sex in abdominal pain. Methods We used primary cultures of sensory neurons from dorsal root ganglia (DRG) of female and male conventional mice (SPF) or germ-free (GF) mice, age 7–18 weeks. To study the visceral afferent activity in vitro, calcium mobilization in DRG sensory neurons was measured by inverted fluorescence microscope using a fluorescent calcium probe Fluo-4 (1mM). Two parameters were considered: i) percentage of responding neurons and ii) intensity of neuronal response. First, DRG sensory neurons were stimulated by a TRPV1 agonist capsaicin (12.5nM, 125nM and 1.25µM) or by an agonist mix of G-protein coupled receptors (GPCR: bradykinin, histamine and serotonin; 1µM, 10µM and 100µM). We next cultured Escherichia coli JM83 (E. coli) and Enterobacter aerogenes (E. aer) overnight in LB and LDMIIG medium, respectively. Bacterial supernatant of 1010 CFU/mL was diluted to 1% in Krebs Ringer solution to treat DRG neurons from GF/SPF mice and calcium mobilization was measured. Results The percentage of neurons responding to capsaicin and GPCR agonist was similar in SPF male and SPF female. In contrast, the intensity of the neuronal response was higher in SPF male compared to SPF female mice in response to capsaicin (125nM p<0.035 and 1.25µM p<0.038) but not in response to GPCR. The same trend was observed in GF mice. Neuronal activation induced by capsaicin or GPCR agonist was similar in SPF and GF mice. While bacterial supernatant from E. coli did not affect the activity of sensory neurons, the bacterial supernatant from E. aer induced changes in calcium mobilization in DRG neurons. Conclusions Our data suggest that at the level of DRG neurons from healthy mice, female sex and the absence of gut microbiota do not predispose to visceral hypersensitivity. In fact, the intensity of neuronal responses to capsaicin appear to be higher in DRGs from male mice. Furthermore, we show that metabolites from certain bacteria can activate sensory neurons. Thus, further studies are needed to investigate the role of gut microbiota and sex in visceral sensitivity Funding Agencies CIHR

735 DORSAL ROOT GANGLIA (DRG) NEURONAL RESPONSES AND SUBSTANCE P PRODUCTION ARE HIGHER IN MALE MICE AND SIMILAR BETWEEN CONVENTIONAL AND GERM-FREE MICE.

2021 ◽  
Vol 160 (6) ◽  
pp. S-148
Author(s):  
Julien Pujo ◽  
Giada De Palma ◽  
Jun Lu ◽  
Stephen M. Collins ◽  
Premysl Bercik
Keyword(s):  
Substance P ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Male Mice ◽  
Neuronal Responses ◽  
Germ Free

10 THE ROLE OF DIETARY L-SERINE IN THE REGULATION OF INTESTINAL MUCUS BARRIER DURING INFLAMMATION

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Control Diet ◽  
Bacterial Strains ◽  
Germ Free ◽  
Intestinal Mucus ◽  
Gnotobiotic Mice ◽  
Mucus Barrier

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

scholarly journals Lupus Gut Microbiota Transplants Cause Autoimmunity and Inflammation

2021 ◽  
Author(s):  
Yiyangzi Ma ◽  
Ruru Guo ◽  
Yiduo Sun ◽  
Xin Li ◽  
Lun He ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Lupus Erythematosus ◽  
Fecal Microbiota Transplantation ◽  
Fecal Microbiota ◽  
Healthy Controls ◽  
Germ Free ◽  
Autoimmune Antibodies ◽  
Expression Of Genes ◽  
Rdna Sequencing

Background: The etiology of systemic lupus erythematosus (SLE) is multifactorial. Recently, growing evidence suggests that the microbiota plays a role in SLE, yet whether gut microbiota participates in the development of SLE remains largely unknown. To investigate this issue, we carried out 16s rDNA sequencing analyses in a cohort of 18 female un-treated active SLE patients and 7 female healthy controls, and performed fecal microbiota transplantation from patients and healthy controls to germ-free mice. Results: Compared to the healthy controls, we found no significant different microbial diversity but some significantly different species in SLE patients including Turicibacter genus and other 5 species. Fecal transfer from SLE patients to germ free (GF) C57BL/6 mice caused GF mice to develop a series of lupus-like phenotyptic features, which including an increased serum autoimmune antibodies, and imbalanced cytokines, altered distribution of immune cells in mucosal and peripheral immune response, and upregulated expression of genes related to SLE in recipient mice that received SLE fecal microbiota transplantation (FMT). Moreover, the metabolism of histidine was significantly altered in GF mice treated with SLE patient feces, as compared to those which received healthy fecal transplants. Conclusions: Overall, our results describe a causal role of aberrant gut microbiota in contributing to the pathogenesis of SLE. The interplay of gut microbial and histidine metabolism may be one of the mechanisms intertwined with autoimmune activation in SLE.

M1221 The Role of Substance P and Mast Cells as Immunohistologic Biomarkers for Chronic Abdominal Pain in Children

2010 ◽  
Vol 138 (5) ◽  
pp. S-357
Author(s):  
Wendy A. Henderson ◽  
Tara J. Taylor ◽  
Ravi Shankar ◽  
Miriam R. Anver ◽  
Donna O. Butcher ◽  
...  
Keyword(s):  
Abdominal Pain ◽  
Mast Cells ◽  
Substance P ◽  
Chronic Abdominal Pain

scholarly journals Sensation of Abdominal Pain Induced by Peritoneal Carcinomatosis Is Accompanied by Changes in the Expression of Substance P and μ-Opioid Receptors in the Spinal Cord of Mice

2012 ◽  
Vol 117 (4) ◽  
pp. 847-856 ◽  
Author(s):  
Masami Suzuki ◽  
Minoru Narita ◽  
Minami Hasegawa ◽  
Sadayoshi Furuta ◽  
Tomoyuki Kawamata ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Abdominal Pain ◽  
Substance P ◽  
Peritoneal Carcinomatosis ◽  
Opioid Receptor ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Receptor Expression ◽  
Tumor Bearing ◽  
Μ Opioid Receptor

Background Patients with peritoneal carcinomatosis often report abdominal pain, which is relatively refractory to morphine. It has been considered that a new animal model is required to investigate the mechanism of abdominal pain for the development of optimal treatments for this type of pain. Methods To prepare a peritoneal carcinomatosis model, highly peritoneal-seeding gastric cancer cells, 60As6, were implanted into the abdominal cavity. The nociceptive modality for pain-related behavior was assessed in terms of withdrawal behavior in response to mechanical stimuli and hunching behavior. Tissue samples from mouse dorsal root ganglia and spinal cord were subject to immunohistochemistry and real-time reverse transcription polymerase chain reaction. Results Mice with peritoneal dissemination showed significant hypersensitivity of the abdomen to mechanical stimulation and spontaneous visceral pain-related behavior. There was a significant increase in c-Fos-positive cells in the spinal cord in tumor-bearing mice. Those mice exhibited a remarkable increase in substance P-positive neurons in the dorsal root ganglia (control vs. tumor, 15.4 ± 1.1 vs. 24.2 ± 3.6, P < 0.05, n = 3). A significant decreases in μ-opioid receptor expression mainly in substance P-positive neurons was observed in tumor-bearing mice (69.3 ± 4.9 vs. 38.7 ± 0.9, P < 0.05, n = 3), and a relatively higher dose of morphine was required to significantly reverse the abdominal hypersensitivity. Conclusion Both the up-regulation of substance P and down-regulation of μ-opioid receptor seen in the dorsal root ganglia may be, at least in part, responsible for the abdominal pain-like state associated with peritoneal carcinomatosis.

Renorenal Reflexes: Role of Substance P and Prostaglandins

Physiology ◽  
1993 ◽  
Vol 8 (5) ◽  
pp. 228-232
Author(s):  
UC Kopp
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Substance P ◽  
Sensory Neurons ◽  
Urine Output ◽  
The Central Nervous System ◽  
Pelvic Pressure

The kidney is capable of transmitting information from sensory neurons to the central nervous system. Prostaglandins and substance P contribute to the activation of renal sensory neurons produced by increases in renal pelvic pressure that lead to a reflex increase in contralateral urine output.

Substance P may attenuate gastric hyperemia by a mast cell-dependent mechanism in the damaged gastric mucosa

1999 ◽  
Vol 277 (5) ◽  
pp. G1064-G1073 ◽  
Author(s):  
Astrid Rydning ◽  
Oddveig Lyng ◽  
Steinar Aase ◽  
Jon Erik Grønbech
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Substance P ◽  
Gastric Mucosa ◽  
Sensory Neurons ◽  
Laser Doppler Flow ◽  
Calcitonin Gene ◽  
Acid Challenge ◽  
Dependent Mechanism

Calcitonin gene-related peptide (CGRP) released from sensory neurons, which are closely apposed to mast cells and blood vessels, mediates gastric hyperemia in response to acid challenge of the damaged mucosa. Substance P (SP) is coreleased with CGRP from sensory neurons, but the role of this peptide in gastric blood flow regulation is largely unknown. Chambered rat stomachs were exposed to 1.5 M NaCl and acidic saline after treatment with SP, aprotinin (serine protease inhibitor), and the mast cell stabilizers ketotifen and sodium cromoglycate (SCG). Gastric hyperemia (measured with a laser Doppler flow velocimeter) after hypertonic injury and acid challenge was nearly abolished by SP. Aprotinin infused together with SP and pretreatment with ketotifen and SCG before SP restored the gastric hyperemia. Ketotifen and SCG inhibited mast cell degranulation in SP-treated rats. Preservation of gastric hyperemia was correlated with improved mucosal repair. These data suggest that impaired hyperemia by SP during acid challenge of the gastric mucosa may be mediated by a mast cell-dependent mechanism involving the release of proteases from mast cells.

Sign in / Sign up

Export Citation Format

Share Document