American journal of physiology. Gastrointestinal and liver physiology
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Am. J. Physiol. Gastrointest. Liver Physiol. · Sep 2019
Colonic afferent input and dorsal horn neuron activation differs between the thoracolumbar and lumbosacral spinal cord.
The distal colon is innervated by the splanchnic and pelvic nerves, which relay into the thoracolumbar and lumbosacral spinal cord, respectively. Although the peripheral properties of the colonic afferent nerves within these pathways are well studied, their input into the spinal cord remain ill defined. The use of dual retrograde tracing from the colon wall and lumen, in conjunction with in vivo colorectal distension and spinal neuronal activation labeling with phosphorylated MAPK ERK 1/2 (pERK), allowed us to identify thoracolumbar and lumbosacral spinal cord circuits processing colonic afferent input. ⋯ NEW & NOTEWORTHY In mice, retrograde tracing from the colon wall and lumen was used to identify unique populations of afferent neurons and central projections within the spinal cord dorsal horn. We show that there are pronounced differences between the spinal cord regions in the distribution pattern of colonic afferent central projections and the pattern of dorsal horn neuron activation evoked by colorectal distension. These findings demonstrate how colonic afferent input influences spinal processing of colonic mechanosensation.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Sep 2019
Heart failure developed after myocardial infarction does not affect gut microbiota composition in the rat.
There is a body of evidence that supports the notion that gut dysbiosis plays a role in the pathogenesis of cardiovascular diseases. Decreased cardiac function can reduce intestinal perfusion, resulting in morphological alterations, which may contribute to changes in the gut microbiota composition in patients with heart failure (HF). In this regard, a germane question is whether changes in gut microbiota composition are a cause or consequence of the cardiovascular disturbance. ⋯ Therefore, we conclude that HF induced by myocardial infarction does not affect gut microbiota composition, at least in rats, indicating that the dysbiosis observed in patients with HF may precede cardiovascular disturbance. NEW & NOTEWORTHY Our study demonstrated that, following myocardial infarction in rats, heart failure (HF) development did not affect the intestinal microbiota despite distinct differences reported in the gut microbiota of humans with HF. Our finding is consistent with the notion that dysbiosis observed in patients with HF may precede cardiovascular dysfunction and therefore offers potential for early diagnosis and treatment.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Aug 2019
Knockdown of long noncoding RNA PVT1 suppresses cell proliferation and invasion of colorectal cancer via upregulation of microRNA-214-3p.
Long noncoding RNAs (lncRNAs) have been reported to be involved in the occurrence and tumorigenesis of numerous malignant cancers. Microarray expression profiles were used to screen colorectal cancer (CRC)-related differentially expressed genes and lncRNAs, which revealed that insulin receptor substrate 1 (IRS1) and lncRNA plasmacytoma variant translocation 1 (PVT1) were highly expressed in CRC. This study aimed to investigate the regulatory role of lncRNA PVT1 in CRC. ⋯ This study suggests that lncRNA PVT1 might be a potential target of therapeutic strategies for CRC treatment. NEW & NOTEWORTHY This study mainly suggests that long noncoding (lnc)RNA plasmacytoma variant translocation 1 (PVT1) is a downregulated lncRNA in colorectal cancer (CRC), accelerating CRC progression. Strikingly, lncRNA PVT1 acts as a competitive endogenous RNA against microRNA (miR)-214-3p, whereas miR-214-3p targets insulin receptor substrate 1, which draws a comprehensive picture of the potential molecular mechanisms of lncRNA PVT1 in CRC.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Aug 2019
microRNA-33a prevents epithelial-mesenchymal transition, invasion, and metastasis of gastric cancer cells through the Snail/Slug pathway.
Invasion and metastasis are responsible for the majority of deaths in gastric cancer (GC). microRNA-33a (miR-33a) might function as a tumor suppressor in multiple cancers. Here, we describe the regulation and function of miR-33a in GC and mechanisms involved in epithelial-mesenchymal transition (EMT) and metastasis. First, GC tissues and adjacent normal tissues were collected. miR-33a upregulation or SNAI2 depletion on GC cells were introduced to assess the detailed regulatory mechanism of them. ⋯ This study suggests that miR-33a inhibited EMT, invasion, and metastasis of GC through the Snail/Slug signaling pathway by modulating SNAI2 expression. NEW & NOTEWORTHY miR-33a targets and inhibits the expression of SNAI2, overexpression of SNAI2 activates the Snail/Slug signaling pathway, the Snail/Slug signaling pathway promotes GC cell proliferation, invasion, and metastasis, and overexpression of miR-33a inhibits cell proliferation, invasion, and metastasis. This study provides a new therapeutic target for the treatment of GC.
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Am. J. Physiol. Gastrointest. Liver Physiol. · Jun 2019
Electroacupuncture via chronically implanted electrodes improves gastrointestinal motility by balancing sympathovagal activities in a rat model of constipation.
Electroacupuncture (EA) has been reported for treating constipation in clinical studies. However, little is known of the possible mechanisms involved in the prokinetic effect of EA. The aim of this study was to investigate the effects and underlying autonomic mechanisms of EA via chronically implanted electrodes for constipation in rat induced by Loperamide (Lop). ⋯ NEW & NOTEWORTHY The findings of the present study suggest that the proposed electroacupuncture (EA) may have great therapeutic potential for treating patients with opioid-induced constipation. It was demonstrated that EA at ST-36 improved transit of every organ along the gut mediated via the autonomic mechanisms in normal rats and rats with Lop-induced constipation. It is advised to administrate EA daily instead of two or three times weekly as reported in most of the clinical studies.