Fig 6 - uploaded by Jinhong Jiang
Content may be subject to copyright.
Contractions of the longitudinal muscle (A) and circular muscle (B) of colon induced by CST-14 (10 À9-10 À6 M). Arrows indicate time of compound addition to bath. (C-D) Increased baseline contractions after exposure to CST-14 were represented by (*) and were shown on the left. The contractile responses of longitudinal muscle (C) and circular muscle (D) of colon induced by CST-14 (10 À6 M) were significantly modified by c-SOM in the concentration of 10 À5 M, respectively (n = 8-9).
Source publication
Background
This study aimed to investigate the functional roles of Cortistatin-14 (CST-14) in the gastrointestinal motility.
Methods
For in vivo study, mice were randomly divided into control, ip injected CST-14 (0.1, 0.5, 1, 5, 10 mg/kg) + control group, icv injected CST-14 (5 μg) + control group, dextran sulfate sodium-induced colitis group, CST...
Contexts in source publication
Context 1
... longitudinal and circular muscle contractions were further studied in the distal colon. CST-14 (10 À9 -10 À6 M) elicited contractile response both in the longitudinal and circular colon muscle in a concentration-dependent manner, and the effect was lower than that evoked by 10 mM carbachol (Fig. 6A and ...
Context 2
... order to examine whether sst receptors participate in regulating muscle contractions caused by CST-14, c-SOM, a non- selective antagonist of sstr1-5, were further investigated. The results showed that c-SOM fully abolished the contractile responses induced by CST-14 (10 À6 M) in the corresponding concentration both in longitudinal muscles and circular muscles ( Fig. 6C and D) [18]. Meanwhile, all the results mentioned above were also investigated on the muscles of ileum (Fig. ...
Context 3
... longitudinal and circular muscle contractions were further studied in the distal colon. CST-14 (10 À9 -10 À6 M) elicited contractile response both in the longitudinal and circular colon muscle in a concentration-dependent manner, and the effect was lower than that evoked by 10 mM carbachol (Fig. 6A and ...
Context 4
... order to examine whether sst receptors participate in regulating muscle contractions caused by CST-14, c-SOM, a non- selective antagonist of sstr1-5, were further investigated. The results showed that c-SOM fully abolished the contractile responses induced by CST-14 (10 À6 M) in the corresponding concentration both in longitudinal muscles and circular muscles ( Fig. 6C and D) [18]. Meanwhile, all the results mentioned above were also investigated on the muscles of ileum (Fig. ...
Similar publications
Although gastrointestinal complications are a common feature of patients with chronic kidney disease (CKD), the impact of uremia on bowel motility remains poorly understood. The present study was, therefore, designed to investigate the impact of uremia on gut motility. Kidney failure was induced in mice by chemical nephrectomy using an adenine diet...
Citations
... Hence, this finding led us to conclude that the intensity of the mag- In mice, other methods for GI motility measures include evaluating the propulsion time of a bead inserted in the colon to a certain distance from anus and fecal pellet output in relation to the number and dry weight. 44,48 Altered fecal output has been primarily associated with changes in colonic transit, 46 but upper GI transit can also influence it. 28,49,50 The OATT differences also reflect the fecal Regarding the morphometric analysis, BALB/c had a greater gastric muscular thickness than C57BL/6. ...
... Based on the percentage of ferrite excreted in feces, it was observed that the C57BL/6 strain retained most of the magnetic material at the end of the 10-hour evaluation. Miller et al15 followed the GI transit in mice for 4 hours, and they showed that a large proportion of tracer was in cecum and colon of BALB/c, but remained concentrated in the stomach and small intestine of C57BL/6.In rodents, GI transit is typically monitored by the visual observation of the first appearance of the marker in the feces or by measuring the distance traveled by a tracer into the gastrointestinal segments after the death of the animals.43,44 Whole-gut transit evaluated by the dye method from oral gavage was 130 minutes for BALB/c 45 and 100-140 minutes for C57BL/6.46,47 ...
Background
BALB/c and C57BL/6 mice are widely used in biomedical research; however, the differences between strains are still underestimated. Our aims were to develop an experimental protocol to evaluate the duodenal contractility and gastrointestinal transit in mice using the Alternating Current Biosusceptometry (ACB) technique and to compare gastrointestinal motor function and morphology between BALB/c and C57BL/6 strains.
Methods
Male mice were used in experiments (a) duodenal contractility: animals which had a magnetic marker surgically fixed in the duodenum to determine the frequency and amplitude of contractions and (b) gastrointestinal transit: animals which ingested a magnetically marked chow to calculate the Oro‐Anal Transit Time (OATT) and the Fecal Pellet Elimination Rate (FPER). The animals were killed after the experiments for organ collection and morphometric analysis.
Key Results
BALB/c and C57BL/6 had two different duodenal frequencies (high and low) with similar amplitudes. After 10 hours of monitoring, BALB/c eliminated around 89% of the ingested marker and C57BL/6 eliminated 33%; OATT and FPER were slower for C57BL/6 compared with BALB/c. The OATT and amplitude of low frequency had a strong positive correlation in C57BL/6. For BALB/c, the gastric muscular layer was thicker compared to that measured for C57BL/6.
Conclusions and Inferences
The experimental protocol to evaluate duodenal contractility and fecal magnetic pellets output using the ACB technique in mice was successfully established. BALB/c strains had higher duodenal frequencies and a shorter time to eliminate the ingested marker. Our results showed differences in both motor function and gastrointestinal morphology between BALB/c and C57BL/6 strains.
... The colons were removed from mice. RT-qPCR was performed according to the previous reports and manufacturer's instructions [40]. Total RNA was extracted using Trizol reagent (TaKaRa, Dalian,China) and 1 µg of RNA sample was reverse transcribed into complementary DNA (cDNA) with the 5X PrimeScript RT Master Mix (TaKaRa). ...
Backgrounds: This study aimed to investigate the protective effects of MMI-0100, a cell-penetrating peptide inhibitor of MAPK-activated protein kinase II (MK2), on acute colitis induced by dextran sodium sulfate (DSS). Mice were injected intraperitoneally with different doses of MMI-0100 (0.5 and 1 mg/kg per day, six days). The physiological indexes, the parameters for colonic pathological injury and the intensity of inflammatory responses were evaluated by histological staining, quantitative PCR, western blotting, and immunostaining. MMI-0100 attenuated DSS-induced body weight loss, colon length shortening, and colonic pathological injury, including decreased myeloperoxidase (MPO) and inhibited inflammatory cell infiltration. MMI-0100 suppressed DSS-induced activation of CD11b+ and F4/80 positive cell, and dramatically decreased the expression of a series of pro-inflammatory cytokines such as TNF-α, IL-6, IL-1β, TGF- β, IFN-γ, IL-17A, COX-2 and iNOS. A TUNEL assay showed that MMI-0100 protected against DSS-induced apoptosis. This is consistent with the results of Western blotting assay in apoptosis-related proteins including Bcl-2, BAX, caspase-3. The anti-inflammatory effects of MMI-0100 on DSS-induced colitis were achieved by down-regulating the phosphorylation level of MK2, IκBα and p65 protein. The current study clearly demonstrates a protective role for MMI-0100 in experimental IBD.
Background
P17, a peptide isolated from Tetramorium bicarinatum ant venom, is known to induce an alternative phenotype of human monocyte-derived macrophages via activation of an unknown G protein-coupled receptor (GPCR).
Objective
We have investigated the mechanism of action and the immunomodulatory effects of P17 mediated through MRGPRX2.
Methods
To identify the GPCR for P17, we screened 314 GPCRs. Upon identification of MRGPRX2, a battery of in silico, in vitro, ex vivo and in vivo assays along with the receptor mutation studies were performed. In particular, to investigate the immunomodulatory actions, we employed β-hexosaminidase release assay, cytokine releases, quantification of mRNA expression, cell migration and differentiation assays, immunohistochemical labeling, H&E, and immunofluorescence staining.
Results
P17 activated MRGPRX2 in a dose-dependent manner in β-arrestin recruitment assay. In LAD2 cells, P17 induced calcium and β-hexosaminidase release. Quercetin and shRNA mediated knockdown of MRGPRX2 reduced P17-evoked β-hexosaminidase release. In silico and in vitro mutagenesis studies showed residue Lys⁸ of P17 formed a cation-π interaction with the Phe¹⁷² of MRGPRX2 and [Ala⁸]P17 lost its activity partially. P17 activated LAD2 cells to recruit THP-1 and human monocytes in Transwell migration assay, whereas MRGPRX2-impaired LAD2 cells cannot. In addition, P17-treated LAD2 cells stimulated differentiation of THP-1 and human monocytes, as indicated by the enhanced expressions of macrophage markers CD11b and TNF-α by qRT-PCR. Immunohistochemical and immunofluorescent staining suggested monocyte recruitment in mice ears injected with P17.
Conclusion
Our data provide novel structural information regarding the interaction of P17 with MRGPRX2 and intracellular pathways for its immunomodulatory action.
Endokinin A/B (EKA/B), the common C-terminal decapeptide in endokinins A and B, is a preferred ligand of NK1 receptor and regulates pain and itch. The study focused on the effects of EKA/B on rat gastric motility in vivo and in vitro. Gastric emptying was measured to evaluate gastric motility in vivo. Intragastric pressure and the contraction of gastric muscle strips were measured to evaluate gastric motility in vitro. Moreover, various neural blocking agents and neurokinin receptor antagonists were applied to explore the mechanisms. TAC4 and TACR1 mRNA were expressed throughout rat stomach. EKA/B promoted gastric emptying by intraperitoneal injection in vivo. Correspondingly, EKA/B also increased intragastric pressure in vitro. Additionally, EKA/B contracted the gastric muscle strips from the fundus but not from the corpus or antrum. Further studies revealed that the contraction induced by EKA/B on muscle strips from fundus could be significantly reduced by NK1 receptor antagonist SR140333, but not NK2 receptor antagonist, NK3 receptor antagonist or the neural blocking agents used. Our results suggested that EKA/B might stimulate gastric motility mainly through the direct activation of myogenic NK1 receptors located in the fundus.
Background: Accumulating evidence suggests inhibiting neuroinflammation as a potential target in therapeutic or preventive strategies for Alzheimer's disease (AD). MAPK-activated protein kinase II (MK2), downstream kinase of p38 mitogen activated protein kinase (MAPK) p38 MAPK, was unveiled as a promising option for the treatment of AD. Increasing evidence points at MK2 as involved in neuroinflammatory responses. MMI-0100, a cell-penetrating peptide inhibitor of MK2, exhibits anti-inflammatory effects and is in current clinical trials for the treatment of pulmonary fibrosis. Therefore, it is important to understand the actions of MMI-0100 in neuroinflammation.
Methods: The mouse memory function was evaluated using novel object recognition (NOR) and object location recognition (OLR) tasks. Brain hippocampus tissue samples were analyzed by quantitative PCR, Western blotting, and immunostaining. Near-infrared fluorescent and confocal microscopy experiments were used to detect the brain uptake and distribution after intranasal MMI-0100 application.
Results: Central MMI-0100 was able to ameliorate the memory deficit induced by Aβ1−42 or LPS in novel object and location memory tasks. MMI-0100 suppressed LPS-induced activation of astrocytes and microglia, and dramatically decreased a series of pro-inflammatory cytokines such as TNF-α, IL-6, IL-1β, COX-2, and iNOS via inhibiting phosphorylation of MK2, but not ERK, JNK, and p38 in vivo and in vitro. Importantly, one of the reasons for the failure of macromolecular protein or peptide drugs in the treatment of AD is that they cannot cross the blood–brain barrier. Our data showed that intranasal administration of MMI-0100 significantly ameliorates the memory deficit induced by Aβ1−42 or LPS. Near-infrared fluorescent and confocal microscopy experiment results showed that a strong fluorescent signal, coming from mouse brains, was observed at 2 h after nasal applications of Cy7.5-MMI-0100. However, brains from control mice treated with saline or Cy7.5 alone displayed no significant signal.
Conclusions: MMI-0100 attenuates Aβ1−42- and LPS-induced neuroinflammation and memory impairments via the MK2 signaling pathway. Meanwhile, these data suggest that the MMI-0100/MK2 system may provide a new potential target for treatment of AD.
