American journal of physiology. Gastrointestinal and liver physiology
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Am. J. Physiol. Gastrointest. Liver Physiol. · Aug 2018
Randomized Controlled TrialPreventive effects of transcutaneous electrical acustimulation on ischemic stroke-induced constipation mediated via the autonomic pathway.
The aim of this study was to explore the preventive effect and possible mechanisms of transcutaneous electrical acustimulation (TEA) on stroke-induced constipation. A total of 86 ischemic stroke patients were randomly allocated to 2-wk TEA or sham-TEA group. Bowel dairy and Bristol Stool Form Scale were recorded daily. ⋯ NEW & NOTEWORTHY This study illustrated that the brain-gut dysfunction, primarily autonomic function imbalance, was correlated with the stroke-induced constipation. This was the first study to report that transcutaneous electrical acustimulation had a preventive effect on stroke-induced constipation, suggesting a potential novel therapy for bowel problem management. The effect was possibly mediated via the autonomic function.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Jun 2018
cGAS-mediated autophagy protects the liver from ischemia-reperfusion injury independently of STING.
Liver ischemia-reperfusion (I/R) injury occurs through induction of oxidative stress and release of damage-associated molecular patterns (DAMPs), including cytosolic DNA released from dysfunctional mitochondria or from the nucleus. Cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) is a cytosolic DNA sensor known to trigger stimulator of interferon genes (STING) and downstream type 1 interferon (IFN-I) pathways, which are pivotal innate immune system responses to pathogen. However, little is known about the role of cGAS/STING in liver I/R injury. ⋯ Our findings indicate a novel protective role for cGAS in the regulation of autophagy during liver I/R injury that occurs independently of STING. NEW & NOTEWORTHY Our studies are the first to document the important role of cGAS in the acute setting of sterile injury induced by I/R. Specifically, we provide evidence that cGAS protects liver from I/R injury in a STING-independent manner.
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Am. J. Physiol. Gastrointest. Liver Physiol. · May 2018
lncRNA MIAT promotes proliferation and invasion of HCC cells via sponging miR-214.
The aberrant expression of long noncoding RNAs (lncRNAs) has been involved in various human tumors including hepatocellular carcinoma (HCC). Our study aimed to investigate the potential molecular mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in HCC. The expression of MIAT and micro-RNA (miR)-214 in HCC tissues and cells was examined by quantitative real-time PCR, and the levels of enhancer of zeste homolog 2 (EZH2) and β-catenin were detected by Western blot assay. ⋯ NEW & NOTEWORTHY This is the first research showing long noncoding RNA (lncRNA) myocardial infarction-associated transcript (MIAT) to have a regulatory effect on hepatocellular carcinoma. Micro-RNA (miR)-214 could be sponged by MIAT to promote the proliferation and invasion of hepatocellular carcinoma cells. The lncRNA MIAT/miR-214 axis brings a novel insight for the therapy and prognosis of hepatocellular carcinoma.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Mar 2018
Visceral hypersensitivity induced by optogenetic activation of the amygdala in conscious rats.
In vivo optogenetics identifies brain circuits controlling behaviors in conscious animals by using light to alter neuronal function and offers a novel tool to study the brain-gut axis. Using adenoviral-mediated expression, we aimed to investigate whether photoactivation with channelrhodopsin (ChR2) or photoinhibition with halorhodopsin (HR3.0) of fibers originating from the central nucleus of the amygdala (CeA) at the bed nucleus of the stria terminalis (BNST) had any effect on colonic sensitivity. We also investigated whether there was any deleterious effect of the adenovirus on the neuronal population or the neuronal phenotype within the CeA-BNST circuitry activated during the optogenetic stimulation. ⋯ NEW & NOTEWORTHY Our findings reveal that optogenetic technology can be employed as a tool to advance understanding of the brain-gut axis. Using adenoviral-mediated expression of opsins, which were activated by laser light and targeted by fiber optic cannulae, we examined central nociceptive circuits mediating visceral pain in a freely moving rat. Photoactivation of amygdala fibers in the stria terminalis with channelrhodopsin induced colonic hypersensitivity, whereas inhibition of the same fibers with halorhodopsin did not alter colonic sensitivity.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Feb 2018
Comparative StudyCGRPα within the Trpv1-Cre population contributes to visceral nociception.
The role of calcitonin gene-related peptide (CGRP) in visceral and somatic nociception is incompletely understood. CGRPα is highly expressed in sensory neurons of dorsal root ganglia and particularly in neurons that also express the transient receptor potential cation channel subfamily V member 1 (Trpv1). Therefore, we investigated changes in visceral and somatic nociception following deletion of CGRPα from the Trpv1-Cre population using the Cre/lox system. ⋯ NEW & NOTEWORTHY The neuropeptide calcitonin gene-related peptide (CGRP) is highly colocalized with transient receptor potential cation channel subfamily V member 1 (TRPV1)-expressing primary afferent neurons, but the functional role of CGRPα specifically in these neurons is unknown in pain processing from visceral and somatic afferents. We used cre-lox recombination to conditionally delete CGRPα from TRPV1-expressing neurons in mice. We show that CGRPα from within TRPV1-cre population plays an important role in visceral nociception but less so in somatic nociception.