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c-Ret-mediated cerebellar hypoplasia with immature GCs was rescued by SAG treatment and by reduced expression of Patched1. A, retention times (seconds) of 21-day-old YF/YF-mice (n = 8), YF/YF-mice treated with SAG (n = 8), YF/YF;Patched1-KO(+/−)-mice (YF/YF;P(+/−), n = 5) and littermate WT mice (n = 8) on the rotarod (at 5 rpm) are shown. Four groups were allowed a maximum retention time of 120 s per trial. The results of triplicate measurements with 5-min intervals after having training twice are shown with dot plots. B, immunohistochemistry of 21-day-old WT mice, YF/YFmice, YY/YF-mice treated with SAG and YF/YF;P(+/−)-mice using anti-BLBP (upper panels) and anti-GABRA6 (lower panels). Scale bars: 20 μm. C, number of BLBP-positive glial fibers (mean ± SD, per 100 μm) with lengths of more than 50 μm in the EGL and (D) GABRA6-positive cell density (mean ± SD, per 10,000 μm 2 ) in WT mice, YF/YF-mice, YY/YF-mice treated with SAG and YF/YF;P(+/−)-mice (n = 5, each). The results of three serial sections from five mice are shown with dot plots. Significant difference (**p < 0.01) was analyzed by the Steel-Dwass test.
Source publication
The c-RET proto-oncogene encodes a receptor-tyrosine kinase. Loss-of-function mutations of RET have been shown to be associated with Hirschsprung disease and Down's syndrome (HSCR-DS) in humans. DS is known to involve cerebellar hypoplasia, which is characterized by reduced cerebellar size. Despite the fact that c-Ret has been shown to be associate...
Contexts in source publication
Context 1
... a previous study, axonal trafficking of Shh with synaptic vesicles 2 (SV2) was shown, and it was also shown that mutant Shh caused decreased secretion as well as impaired trafficking in primary neurons (21). In this study, c-Ret-KI YF/YF -mice had decreased expression of SV2 and less colocalization of Shh with SV2 in the EGL than those in WT mice (Fig. S4). (Fig. 4A). Decreased numbers of BLBP-positive glial fibers and GABRA6-positive mature GCs in c-Ret-KI YF/YF -mice were significantly rescued in c-Ret-KI YF/YF -mice treated with SAG (Fig. 4, B-D). We finally crossed c-Ret-KI YF/+ -mice and Patched1 knockout mice to examine whether c-Ret-mediated cerebellar hypoplasia is rescued by ...
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... study, axonal trafficking of Shh with synaptic vesicles 2 (SV2) was shown, and it was also shown that mutant Shh caused decreased secretion as well as impaired trafficking in primary neurons (21). In this study, c-Ret-KI YF/YF -mice had decreased expression of SV2 and less colocalization of Shh with SV2 in the EGL than those in WT mice (Fig. S4). (Fig. 4A). Decreased numbers of BLBP-positive glial fibers and GABRA6-positive mature GCs in c-Ret-KI YF/YF -mice were significantly rescued in c-Ret-KI YF/YF -mice treated with SAG (Fig. 4, B-D). We finally crossed c-Ret-KI YF/+ -mice and Patched1 knockout mice to examine whether c-Ret-mediated cerebellar hypoplasia is rescued by decreased ...
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... neurons (21). In this study, c-Ret-KI YF/YF -mice had decreased expression of SV2 and less colocalization of Shh with SV2 in the EGL than those in WT mice (Fig. S4). (Fig. 4A). Decreased numbers of BLBP-positive glial fibers and GABRA6-positive mature GCs in c-Ret-KI YF/YF -mice were significantly rescued in c-Ret-KI YF/YF -mice treated with SAG (Fig. 4, B-D). We finally crossed c-Ret-KI YF/+ -mice and Patched1 knockout mice to examine whether c-Ret-mediated cerebellar hypoplasia is rescued by decreased expression of Patched1, a receptor for Shh, and a negative regulator for Shh-mediating signaling (22,23). The ataxic phenotype and the decreased numbers of BLBP-positive glial fibers and ...
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... whether c-Ret-mediated cerebellar hypoplasia is rescued by decreased expression of Patched1, a receptor for Shh, and a negative regulator for Shh-mediating signaling (22,23). The ataxic phenotype and the decreased numbers of BLBP-positive glial fibers and matured GCs in c-Ret-KI YF/YFmice were also rescued in c-Ret-KI YF/YF ;Patched1-KO(+/−)-mice (Fig. 4, A-D). On the other hand, the c-Retmediated megacolon phenotype of HSCR was not rescued by reduced expression of Patched1 at least in this experimental condition (Fig. S5), although we have not examined the effect of SAG on ...
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... successive trials on the rotating rod with 5-min intervals were performed and the results are shown in Figure 1E. For the results shown in Figure 4A, three tests on with 5-min intervals were performed after training twice on the rotating rod. For the footprint test, the front paws and back paws of mice were painted red and blue, respectively. ...
Citations
... A study investigating the role of this gene in Hirschsprung's disease showed that mutations in the c-RET and c-Ret genes also led to hearing loss in human and rodent models, respectively, (Ohgami et al., 2010). A more recent animal study has shown that mutations in this gene may additionally lead to underdevelopment of the cerebellum in the brain (Ohgami et al., 2021). ...
Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.
... It then causes the proximal colon to expand and hypertrophy, eventually resulting in the formation of a megacolon. Rearranged during transfection (RET) has recently been identified as a major regulator of ENCC formation, and inactivating mutations in this gene could result in HSCR (Ohgami et al., 2021). Accumulating evidence indicates that circRNAs are dysregulated and play critical roles in the development of HSCR. ...
CircRNA E3 ubiquitin protein ligase (ITCH) (circRNA ITCH, circ-ITCH), a stable closed-loop RNA derived from the 20q11.22 region of chromosome 20, is a new circRNA discovered in the cytoplasm in recent decades. Studies have shown that it does not encode proteins, but regulates proteins expression at different levels. It is down-regulated in tumor diseases and is involved in a number of biological activities, including inhibiting cell proliferation, migration, invasion, and promoting apoptosis. It can also alter disease progression in non-tumor disease by affecting the cell cycle, inflammatory response, and critical proteins. Circ-ITCH also holds a lot of promise in terms of tumor and non-tumor clinical diagnosis, prognosis, and targeted therapy. As a result, in order to aid clinical research in the hunt for a new strategy for diagnosing and treating human diseases, this study describes the mechanism of circ-ITCH as well as its clinical implications.
... Abnormal protein phosphorylation can lead to the abnormal migration and proliferation of cells [20,21]. In HSCR studies, some scholars have found the abnormal phosphorylation of RET, ERK, and other proteins in HSCR [22,23], indicating the presence of abnormal protein phosphorylation in the pathogenesis of HSCR, but there are few related literature reports. ...
Rac1 can affect the migration of neural crest cells by regulating the polymerization of actin and the membrane formation process. But the role of the Rac1 signaling pathway in the pathogenesis of Hirschsprung’s disease (HSCR) remains unclear. In order to investigate the mechanism of the abnormal protein phosphorylation of Rac1, Lim-kinase 1 (Limk1) and Cofilin involved in the pathogenesis of HSCR. The protein phosphorylation levels of these proteins were detected by Western blot in 30 samples of HSCR narrow segment, 30 samples of transitional segment tissues, and 14 samples of normal intestinal tissues. Subsequently, in the SH-SY5Y human neuroblastoma cell line, a Rac1, Limk1, and Cofilin inhibitor group, a Rac1 overexpression group (PDGF-BB group), a Rac1 overexpression group + a Limk1 inhibitor group (P-B group), a Rac1 overexpression group + a Cofilin inhibitor group (P-C group) were established. The results showed that the expressions of p-Rac1, p-Limk1, and p-Cofilin in HSCR narrow segment and transitional segment were lower than those in normal intestine (p < 0.05). The expression levels of p-Rac1, p-Limk1, and p-Cofilin in the relative inhibitor group were significantly lower than those in the control group (p < 0.05), and the proliferation and migration levels in the control group and Rac1 overexpression group were significantly higher than those in the Rac1, Limk1, and Cofilin inhibitor group (p < 0.05). In conclusion, the decreased phosphorylation of the Rac1/Limk1/Cofilin signaling pathway in HSCR could inhibit the proliferation and migration of SH-SY5Y cells, and this might be associated with the pathogenesis of HSCR.
... 28 Ohgami also revealed that loss-of-function mutations of RET was associated with HSCR in humans. 29 Our research were involved in the expression and regulation mechanism of RET in HSCR, while it has not yet involved the detection of RET gene mutations in HSCR patients. The specific content needs to be verified after further genetic detection in the future. ...
Background:
Hirschsprung disease (HSCR) is a congenital intestinal disease caused by the abnormal proliferation and migration of enteric nerve cells (ENCC). Research suggested critical roles for circular RNA (circRNA) itchy E3 ubiquitin protein ligase (ITCH) in gastrointestinal malignancies progression. However, the function of circ-ITCH in HSCR remains poorly defined.
Methods:
The related genes expression in 30 HSCR patients and 30 controls without HSCR were detected using qRT-PCR. Cell proliferation was assessed by CCK-8 assay and EdU assay. Cell migration was detected with wound-healing assay and transwell assay. The interactions among circ-ITCH, miR-146b-5p, and RET were confirmed by Dual luciferase reporter assay.
Results:
Circ-ITCH and RET expressions were downregulated in HSCR patients and cells, while the miR-146b-5p expression was upregulated. Circ-ITCH overexpression facilitated cell proliferation, migration, and activated MAPK pathway, which were reversed by circRNA-ITCH knockdown. Circ-ITCH negatively regulated miR-146b-5p expression. MiR-146b-5p overexpression abolished the promoting effects of circ-ITCH overexpression on cell proliferation and migration. MiR-146b-5p inhibited RET expression. RET overexpression eliminated the inhibitory effects of miR-146b-5p overexpression on cell proliferation and migration.
Conclusion:
Circ-ITCH overexpression facilitated cell proliferation and migration in HSCR by regulating miR-146b-5p/RET/MAPK axis.
Impact:
The expressions of Circ-ITCH and RET were markedly reduced in HSCR, while miR-146b-5p expression was increased in HSCR. Circ-ITCH overexpression enhanced the proliferative and migratory abilities of SH-SY5Y and 293T cells. Circ-ITCH negatively regulated miR-146b-5p expression.
