scholarly journals The Role and Mechanism of AMIGO3 in the Formation of Aberrant Neural Circuits After Status Convulsion in Immature Mice

2021 ◽  
Vol 14 ◽  
Author(s):  
Xue Li ◽  
Yanan Pan ◽  
Jianxiong Gui ◽  
Zhixu Fang ◽  
Dishu Huang ◽  
...  

Leucine rich repeat and immunoglobulin-like domain-containing protein 1 (Lingo-1) has gained considerable interest as a potential therapy for demyelinating diseases since it inhibits axonal regeneration and myelin production. However, the results of clinical trials targeted at Lingo-1 have been unsatisfactory. Amphoterin-induced gene and open reading frame-3 (AMIGO3), which is an analog of Lingo-1, might be an alternative therapeutic target for brain damage. In the present study, we investigated the effects of AMIGO3 on neural circuits in immature mice after status convulsion (SC) induced by kainic acid. The expression of both AMIGO3 and Lingo-1 was significantly increased after SC, with levels maintained to 20 days after SC. Following SC, transmission electron microscopy revealed the impaired microstructure of myelin sheaths and Western blot analysis showed a decrease in myelin basic protein expression, and this damage was alleviated by downregulation of AMIGO3 expression. The ROCK/RhoA signaling pathway was inhibited at 20 days after SC by downregulating AMIGO3 expression. These results indicate that AMIGO3 plays important roles in seizure-induced damage of myelin sheaths as well as axon growth and synaptic plasticity via the ROCK/RhoA signaling pathway.

Cell Reports ◽  
2020 ◽  
Vol 31 (6) ◽  
pp. 107639 ◽  
Author(s):  
Carlos Wilson ◽  
Luciana E. Giono ◽  
Victoria Rozés-Salvador ◽  
Ana Fiszbein ◽  
Alberto R. Kornblihtt ◽  
...  

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Yang Yang ◽  
Xiao-Wei Peng

As one of the most common primary intraocular carcinomas, retinoblastoma generally stems from the inactivation of the retinoblastoma RB1 gene in retinal cells. Antisense non-coding RNA in the INK4 locus (ANRIL), a long non-coding RNA (lncRNA), has been reported to affect tumorigenesis and progression of various cancers, including gastric cancer and non-small cell lung cancer. However, limited investigations emphasized the role of ANRIL in human retinoblastoma. Hence, the current study was intended to investigate the effects of ANRIL on the proliferation, apoptosis, and invasion of retinoblastoma HXO-RB44 and Y79 cells. The lentivirus-based packaging system was designed to aid the up-regulation of ANRIL and ATM expressions or employed for the down-regulation of ANRIL in human retinoblastoma cells. Afterward, ANRIL expression, mRNA and protein expression of ATM and E2F1, and protein expression of INK4b, INK4a, alternate reading frame (ARF), p53 and retinoblastoma protein (pRB) were determined in order to elucidate the regulation effect associated with ANRIL on the ATM-E2F1 signaling pathway. In addition, cell viability, apoptosis, and invasion were detected accordingly. The results indicated that the down-regulation of ANRIL or up-regulation of ATM led to an increase in the expressions of ATM, E2F1, INK4b, INK4a, ARF, p53, and pRB. The silencing of ANRIL or up-regulation of ATM exerted an inhibitory effect on the proliferation and invasion while improving the apoptosis of HXO-RB44 and Y79 cells. In conclusion, the key observations of our study demonstrated that ANRIL depletion could act to suppress retinoblastoma progression by activating the ATM-E2F1 signaling pathway. These results provide a potentially promising basis for the targetted intervention treatment of human retinoblastoma.


2017 ◽  
Vol 18 (10) ◽  
pp. 783-791 ◽  
Author(s):  
Xiao Huaitong ◽  
Feng Yuanyong ◽  
Tao Yueqin ◽  
Zhao Peng ◽  
Shang Wei ◽  
...  

2018 ◽  
Vol 28 (6) ◽  
pp. 691-703 ◽  
Author(s):  
Cheng Yin ◽  
Zong-duo Guo ◽  
Zong-ze He ◽  
Zhen-yu Wang ◽  
Xiao-chuan Sun

Following central nervous system injury in mammals, failed axonal regeneration is closely related to dysneuria. Previous studies have shown that the obvious effects of apolipoprotein E (ApoE) on traumatic brain injury (TBI) were associated with an axonal mechanism. However, little information on the actions of ApoE and its isoforms on axonal regeneration following TBI was provided. In our study, the cerebral cortices of ApoE-deficient (ApoE-/-) and wild-type (ApoE+/+) mice were cultured in vitro, and an axonal transection model was established. Interventions included the conditioned medium of astrocytes, human recombinant ApoE2/3/4 isoforms and inhibitors of the JNK/ERK/p38 pathway. Axonal growth and regeneration were evaluated by measuring the maximum distance and area of the axons. The expression levels of β-tubulin III, MAP2, ApoE, p-JNK, p-ERK and p-p38 were detected by immunofluorescence and western blotting. The results showed that ApoE mRNA and protein were expressed in intact axons and regenerated axons. Axonal growth and regeneration were attenuated in ApoE-/- mice but recovered by exogenous ApoE. Human recombinant ApoE3 positively influenced axonal growth and regeneration; these effects were mediated by the JNK/ERK/p38 pathway. These results suggest ApoE and its isoforms may have influenced axonal growth and regeneration via the MAPK signaling pathway in vitro.


2009 ◽  
Vol 67 (2b) ◽  
pp. 488-493
Author(s):  
Adriano Tony Ramos ◽  
Paulo César Maiorka ◽  
Maria Lúcia Zaidan Dagli ◽  
Fernando Yutaka Moniwa Hosomi ◽  
Kalan Bastos Violin ◽  
...  

The aim of this study was to evaluate the role of connexin 32 (Cx 32) during remyelination of the peripheral nervous system, through a local injection of either 0,1% ethidium bromide solution or saline in the sciatic nerve of Cx 32 knockout mice. Euthanasia was performed ranging from 1, 2, 3, 7, 15, 21 to 30 days after injection. Histochemical, immunohistochemical, immunofluorescence and transmission electron microscopical techniques were used to analyze the development of the lesions. Within the sciatic nerves, Schwann cells initially showed signs of intoxication and rejected their sheaths; after seven days, some thin newly formed myelin sheaths with uneven compactness and redundant loops (tomacula) were conspicuous. We concluded that the regeneration of lost myelin sheaths within the PNS followed the pattern already reported for this model in other laboratory species. Therefore, these results suggest that absence of Cx 32 did not interfere with the normal pattern of remyelination in this model in young mice.


2020 ◽  
Author(s):  
xuezhi zhou ◽  
Yujue Wang ◽  
Manjuan Peng ◽  
Ye He ◽  
Jingjie Peng ◽  
...  

Abstract BackgroundMüller differentiated RGCs have potential therapeutic value for glaucoma. However, axonal regeneration of differentiated RGCs has been a difficult problem. Studies have confirmed that STAT3 and Y27632 play essential roles in regulating neuronal axon regeneration. Whether STAT3 and Y27632 can induce the Müller differentiated RGCs axon regeneration is still unknown.MethodRetina Müller cells were isolated and purified from Day 21 SD rats’ retina and were differentiated into retinal stem cells. The stem cells were randomly divided into five groups (control group, AAV-STAT3 group, shSTAT3 group, Y27632 group and AAV-STAT3 + Y27632 group). The axon length in each group were measured by ImageJ. Immunofluorescence were used to label the RGCs. The mRNA level of pluripotent associated and differentiation-associated proteins was analysed by qRT-PCR. Stem cells in different groups were injected into mice model of glaucoma. Immunohistochemical, Immunohistochemistry and OCT were performed to access RGC layer thickness in glaucoma model. VEP was used to detect the optic nerve conduction function.ResultsIn this study, we found that overexpression of STAT3 could promote the growth of RGCs axons generated by Müller cell differentiation. Combined with Y27632, axonal regeneration was significantly longer than that of the STAT3 group. However, after STAT3 was knocked out, axonal regeneration significantly decreased or even stopped. The mRNA levels of Esrrb, Prdm14, Sox2, and Rex1 in Müller differentiated RGCs after overexpression STAT3 combined with Y27632 were significantly increased, while the mRNA levels of Nestin, Eomes, Mixl1 and Gata4 were significantly decreased. The mRNA levels of Socs3, Pten, Klf9, and Mdm4 were significantly decreased, while the mRNA levels of Dclk2, Armcx1, C-MYC, and Nrn1 were significantly increased. The mRNA levels of differentiation and pluripotency marker genes showed opposite results after STAT3 deletion. After injecting Müller differentiated RGCs intervened by STAT3 combined with Y27632 into the eyes of the glaucoma model mice, the axon length, OCT displayed RGC layer thickness and the electrophysiology indicated by VEP were superior to those of the glaucoma model group.ConclusionsThese findings suggested that STAT3 combined with Y27632 can significantly improve the axonal growth level of RGCs, and reveal the potential mechanism to induce pluripotency of RGCs.


2021 ◽  
pp. 109980042110500
Author(s):  
Feng Zhang ◽  
Qin Xue ◽  
Ting Bai ◽  
Fan Wu ◽  
Shuhan Yan

Background: Postpartum fatigue is a common disorder worldwide and affects both physical and mental functioning. In breastfeeding women, Prolactin (PRL) is not only involved in immunoregulation, but also responsible for lactation. Prolactin levels in women with chronic fatigue are higher than normal, but a chronic fatigue state inhibits postpartum lactation in humans. Objectives: This paper explored the inhibition mechanism of lactation by postpartum fatigue in rats. Methods: Postpartum fatigue models were built by forcing mother rats to stand in water and divided into 3-hour, 9-hour and 15-hour per day fatigue groups according to the underwater time. Mother rats and their offspring were reunited in a dry cage for 90 minutes every 3 hours for feeding. The expression of PRL, PRL receptor (PRLR), Janus Kinase 2 (JAK 2), and Signal transducers and activators of transcription 5 (STAT5) mRNA were analyzed and the microstructure of mammary gland were observed under light and electron microscopy. Results: The expression of pituitary PRL mRNA and its downstream signaling pathway JAK2 and STAT5 mRNA were down-regulated in the severe postpartum fatigue rats. PRL mRNA responses were dose-related to duration of fatigue. The expression of PRLR mRNA increased. Postpartum fatigue led to functional degeneration of mammary gland. The breast lobules were shrunk and the number of alveoli were decreased. Few milk protein granules and fat droplets were observed in the cytoplasm under transmission electron microscope. Conclusion: Postpartum fatigue inhibits the lactation by down-regulating the expression of PRL and PRL-dependent signaling pathway in rats.


2020 ◽  
Author(s):  
Jinxin Wang ◽  
Jing Bai ◽  
Peng Duan ◽  
Hao Wang ◽  
Yang Li ◽  
...  

Abstract Background: Diabetic cardiomyopathy (DCM) severely impairs the health of diabetic patients. Previous studies have shown that the expression of inwardly rectifying potassium channel 6.1 (Kir6.1) in heart mitochondria is significantly reduced in type 1 diabetes. However, whether its expression and function are changed and what role it plays in type 2 DCM have not been reported. This study investigated the role and mechanism of Kir6.1 in DCM.Methods: The cardiac function in mice was analyzed by echocardiography, ELISA, hematoxylin and eosin staining, TUNEL and transmission electron microscopy. The mitochondrial function in cardiomyocytes was measured by the oxygen consumption rate and the mitochondrial membrane potential (ΔΨm). Kir6.1 expression at the mRNA and protein levels was analyzed by quantitative real-time PCR and western blotting (WB), respectively. The protein expression of t-AKT, p-AKT, t-Foxo1, and p-Foxo1 was analyzed by WB.Results: We found that the cardiac function and the Kir6.1 expression in DCM mice were decreased. Kir6.1 overexpression improved cardiac dysfunction and upregulated the phosphorylation of AKT and Foxo1 in the DCM mouse model. Furthermore, Kir6.1 overexpression also improved cardiomyocyte dysfunction and upregulated the phosphorylation of AKT and Foxo1 in cardiomyocytes with insulin resistance. In contrast, cardiac-specific Kir6.1 knockout aggravated the cardiac dysfunction and downregulated the phosphorylation of AKT and Foxo1 in DCM mice. Furthermore, Foxo1 activation downregulated the expression of Kir6.1 and decreased the ΔΨm in cardiomyocytes. In contrast, Foxo1 inactivation upregulated the expression of Kir6.1 and increased the ΔΨm in cardiomyocytes. Chromatin immunoprecipitation assay demonstrated that the Kir6.1 promoter region contains a functional Foxo1-binding site .Conclusions: Kir6.1 improves cardiac dysfunction in DCM, probably through the AKT-Foxo1 signaling pathway. Moreover, the crosstalk between Kir6.1 and the AKT-Foxo1 signaling pathway may provide new strategies for reversing the defective signaling in DCM.


Development ◽  
1996 ◽  
Vol 122 (2) ◽  
pp. 589-597 ◽  
Author(s):  
M. Hoshino ◽  
E. Suzuki ◽  
Y. Nabeshima ◽  
C. Hama

The development of neural circuits is regulated by a large number of factors that are localized at distinct neural sites. We report here the localization of one of these factors, hikaru genki (hig) protein, at synaptic clefts in the pupal and adult nervous systems of Drosophila. In hig mutants, unusually frequent bursting activity of the muscles and abnormal motor behavior during the adult stage suggest the misfunction of neuromuscular circuitry. Our immunohistochemical analyses revealed that hig protein, produced by neurons, is secreted from the presynaptic terminals into the spaces between the presynaptic and postsynaptic terminals. In addition, we have found that the localization of this protein in the synaptic spaces temporally correlates with its functional requirement during a critical period that occurs in the middle stage of pupal formation, a period when a number of dendrite and axon growth cones meet to form synapses. These findings indicate that hig protein functions in the formation of functional neural circuits from the early stages of synapse formation.


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