SCF-KIT signaling induces endothelin-3 synthesis and secretion: Thereby activates and regulates endothelin-B-receptor for generating temporally- and spatially-precise nitric oxide to modulate SCF- and or KIT-expressing cell functions

Arctiin alleviates functional constipation by enhancing intestinal motility in mice

Functional constipation (FC), a common symptom that is primarily associated with intestinal motility dysfunction, is a common problem worldwide. Arctiin (Arc) is a lignan glycoside isolated from the Chinese herbal medicine Arctium lappa L., which is a health food in China. The present study aimed to evaluate the laxative effects of Arc against FC in mice. A model of FC induced by loperamide (5 mg/kg) was established in male Institute of Cancer Research (ICR) mice. Arc was administered at a dose of 100 mg/kg as a protective agent. The faecal status, intestinal motility and histological analyses were evaluated. Furthermore, the levels of gastrointestinal motility-associated neurotransmitters, such as motilin (MTL), nitric oxide (NO), and brain-derived neurotrophic factor (BDNF) and the protective effect of Arc on interstitial cells of Cajal (ICC) were assessed. Arc treatment reversed the loperamide-induced reduction in faecal number and water content and the intestinal transit ratio in ICR mice. Histological analysis confirmed that Arc administration mitigated colonic injury. Moreover, Arc treatment increased levels of motilin and brain-derived neurotrophic factor while decreasing nitric oxide levels and ICC injury in the colon of FC mice. Arc decreased inflammation induction and aquaporin expression levels. Owing to its pro-intestinal motility property, Arc was shown to have a protective effect against FC and may thus serve as a promising therapeutic strategy for the management of FC.

miR‑27a‑3p regulates the inhibitory influence of endothelin 3 on the tumorigenesis of papillary thyroid cancer cells

Several studies on papillary thyroid cancer (PTC) have been performed. However, the effects of endothelin 3 (EDN3) and microRNA (miR)-27a-3p on PTC cells has yet to be investigated, to the best of the authors' knowledge. The present study aimed to explore the biological functions of EDN3 and miR-27a-3p in PTC cells. Bioinformatics analysis was conducted to identify possible key genes and miRs involved in PTC progression. Western blot analysis and reverse transcription-quantitative (RT-q) PCR were employed to confirm the key genes or miRs expressed in PTC cells. Cytological methods were used to detect cell viability, proliferation, apoptosis and migration and luciferase reporter assay was performed to confirm the relationship between END3 and miR-27a-3p. After analyzing the results of gene microarray analyses and RT-qPCR, EDN3 with low expression was identified as the key gene associated with PTC progression. It was also found that EDN3 overexpression in PTC cells impaired cell viability, proliferation and migration but promoted cell apoptosis. In addition, the findings revealed that miR-27a-3p could relieve the inhibitory influence of EDN3 on PTC cells by binding to EDN3 mRNA 3′ untranslated region (UTR), thereby suppressing EDN3 expression. Overall, the results of the present study demonstrated that by binding to EDN3 mRNA 3′UTR, miR-27a-3p could attenuate the inhibitory function of EDN3 in the tumorigenesis of PTC cells.

c-Kit deficiency impairs nitric oxide signaling in smooth muscle cells

INTRODUCTION

Receptor tyrosine kinases have been implicated in various vascular remodeling processes and cardiovascular disease. However, their role in the regulation of vascular tone is poorly understood. Herein, we evaluate the contribution of c-Kit signaling to vasoactive responses.

METHODS

The vascular reactivity of mesenteric arteries was assessed under isobaric conditions in c-Kit deficient (Kit^W/W-v) and littermate control mice (Kit^+/+) using pressure myography. Protein levels of soluble guanylyl cyclase beta 1 (sGCβ1) were quantified by Western blot. Mean arterial pressure was measured after high salt (8% NaCl) diet treatment using the tail-cuff method.

RESULTS

Smooth muscle cells (SMCs) from c-Kit deficient mice showed a 5-fold downregulation of sGCβ1 compared to controls. Endothelium-dependent relaxation of mesenteric arteries demonstrated a predominance of prostanoid vs. nitric oxide (NO) signaling in both animal groups. The dependence on prostanoid-induced dilation was higher in c-Kit mutant mice than in controls, as indicated by a significant impairment in vasorelaxation with indomethacin with respect to the latter. Endothelium-independent relaxation showed significant dysfunction of NO signaling in c-Kit deficient SMCs compared to controls. Mesenteric artery dilation was rescued by addition of a cGMP analog, but not with a NO donor, indicating a deficiency in cGMP production in c-Kit deficient SMCs. Finally, c-Kit deficient mice developed higher blood pressure on an 8% NaCl diet compared to their control littermates.

CONCLUSION

c-Kit deficiency inhibits NO signaling in SMCs. The existence of this c-Kit/sGC signaling axis may be relevant for vascular reactivity and remodeling.