CircORC2 is involved in the pathogenesis of slow transit constipation via modulating the signalling of miR-19a and neurotensin/motilin

Alleviating effects of gut micro-ecologically regulatory treatments on mice with constipation

Treatments targeted for gut microbial regulation are newly developed strategies in constipation management. In this study, the alleviating effects of gut micro-ecologically regulatory treatments on constipation in mice were investigated. Male BALB/c mice were treated with loperamide to induce constipation, and then the corresponding intervention was administered in each group, respectively. The results showed that administration of mixed probiotics (MP), a 5-fold dose of postbiotics (P5), both synbiotics (S and S2), as well as mixed probiotics and postbiotics (MPP) blend for 8 days shortened the time to the first black stool, raised fecal water content, promoted intestinal motility, and increased serum motilin level in loperamide-treated mice. Furthermore, these treatments altered gut microbial composition and metabolism of short-chain fatty acids (SCFA). Based on linear regression analysis, SCFA was positively correlated with serum motilin except for isobutyrate. It suggested gut microbial metabolites affected secretion of motilin to increase gastrointestinal movement and transportation function and thus improved pathological symptoms of mice with constipation. In conclusion, the alteration of gut micro-ecology is closely associated with gastrointestinal function, and it is an effective way to improve constipation via probiotic, prebiotic, and postbiotic treatment.

Characterization of Circular RNA Expression Profiles in Colon Specimens of Patients with Slow Transit Constipation

Background

Slow transit constipation (STC) is a clinical syndrome characterized by a decreased urge to defecate and delayed colonic transit. Circular RNAs (circRNAs) are a recently discovered class of regulatory RNAs that have emerged as critical biomarkers and regulators of various diseases. However, the expression profiles and mechanisms underlying circRNA regulation in human STC tissues have not been explored.

Methods

High-throughput RNA sequencing technology was used to compare the differences in circRNA expression profiles in colon samples taken from patients with STC or controls. Bioinformatics analyses were performed on the host genes of the differentially expressed circRNAs (DE-circRNAs), a competing endogenous RNA network was constructed, and the expression levels of some DE-circRNAs were verified using quantitative real-time polymerase chain reactions (qRT-PCR).

Results

There were 190 DE-circRNAs identified in the STC group. Bioinformatics analysis predicted that the DE-circRNAs were enriched in the relaxation of smooth muscle, actin binding, actin cytoskeleton organization, dilated cardiomyopathy, and cardiac muscle contraction. These results suggest that muscle diseases may be related to the pathogenesis of STC. The expression levels of the 12 most differentially expressed circRNAs were verified using qRT-PCR. In addition, circRNA–microRNA–mRNA regulatory networks were constructed using the 8 most significant circRNAs. Some mRNAs predicted to be closely related to smooth muscle function were found in these networks.

Conclusions

This study provides a helpful blueprint for researchers to select candidate circRNAs for further study of the pathogenesis of STC and screen potential biomarkers or targets for use in the diagnosis and treatment of STC.

The Fecal Microbiota Transplantation: A Remarkable Clinical Therapy for Slow Transit Constipation in Future

Slow transit constipation is a common condition that would be difficult to treat in clinical practice with a widespread incidence in the population. Pharmacotherapy and surgery are common treatment modalities. However, the clinical effect is limited, and patients still suffer from it. As the researchers strived in this field for decades, the profound relationship between slow transit constipation and fecal microbiota transplantation has comprehensively been sustained. It is very pivotal to maintain intestinal homeostasis, the structure function and metabolic function of symbiotic bacteria, which can inhibit the engraftment of intestinal pathogens. This mini review explains the treatment effects and possible mechanisms of the fecal microbiota transplantation in treating slow transit constipation. Simultaneously, it is found that there is significant improvement in the disease by adjusting the intestinal microbes like fecal microbiota transplantation. Fecal microbiota transplantation has efficient therapeutic effects in slow transit constipation compared with traditional therapies.

CircORC2 is involved in the pathogenesis of slow transit constipation via modulating the signalling of miR-19a and neurotensin/motilin

In this study, we aimed to investigate the role of circORC2 in modulating miR‐19a and its downstream signalling during the pathogenesis of STC. In this study, three groups of patients, that is healthy control (HC) group, normal transit constipation (NTC) group (N = 42) and slow transit constipation (STC) group, were, respectively, recruited. RT‐PCR and Western blot analysis were exploited to investigate the changes in the expression levels of miR‐19a and circORC2 in these patients, so as to establish a circORC2/miR‐19a signalling pathway. The basic information of the patients showed no significant differences among different patient groups. Compared with the HC group, concentrations of neurotensin (NST) and motilin (MLN) were both significantly reduced in the NTC and STC groups, especially in the STC group. Also, miR‐19a level was highest, whereas circORC2 level was lowest in the STC group. Furthermore, circORC2 was validated to sponge the expression of miR‐19a, and the transfection of circORC2 reduced the expression of miR‐19a. Meanwhile, MLN and NST mRNAs were both targeted by miR‐19a, and the transfection of circORC2 dramatically up‐regulated the expression of MLN and NST. On the contrary, the transfection of circORC2 siRNA into SMCs and VSMCs exhibited the opposite effect of circORC2. Collectively, the results of this study established a regulatory relationship among circORC2, miR‐19a and neurotensin/motilin, which indicated that the overexpression of circORC2 could up‐regulate the levels of neurotensin and motilin, thus exerting a beneficial effect during the treatment of STC.