Type III NRG-1 plays a regulatory role in the regeneration process of nerves from the beginning of transplantation.

The present study investigated the effect of type III Neuregulin-1 (NRG-1) on changes in the myelin sheath and the recovery of nerve function during the regeneration process following autologous nerve transplantation. Seventy-two Sprague-Dawley rats were divided into a Blank, Model and (antisense oligonucleotide, ASON) group. The Model and ASON groups of SD rats were subjected to autologous nerve transplantation, and the Blank group only had the sciatic nerve exposed. The Model and ASON groups were given local injections of 2 ml PBS buffer solution and 2 ml ASON of Type III NRG-1, respectively, the NRG-1 type III was inhibited by ASON. Changes in the sciatic nerve functional index (SFI) and conduction velocities were observed at different 6 time points. Regeneration of the myelin sheath was observed using transmission electron microscopy. Type III NRG-1 protein was detected using Western blotting and immunohistochemistry, and NRG-1 mRNA was detected using PCR. The SFI of the ASON group was lower than the Model group after transplantation. The conduction velocities of the ASON group on the 14th and 21st days after autologous nerve transplantation were lower than the Model group (P < 0.01). The protein and mRNA expression of type III NRG-1 in the ASON group was lower than the Model group at all 6 time points. The area of medullated nerve fibres was significantly different between the ASON group and the Model group on the 3rd day (P < 0.05), as was the number of medullated nerve fibres per unit area (P < 0.01). The diameter of axons was obviously different between the two groups (P < 0.01). Type III NRG-1 played an important regulatory role in the regeneration process of the nerve from the beginning of transplantation to the 28th day.

Changes in Type II NRG-1 Expression during Regeneration Following Autologous Nerve Transplantation in Rats.

AIM: To investigate the changes in type II neuregulin-1 (NRG-1) during the regeneration process following autologous sciatic nerve transplantation in rats. MATERIAL AND METHODS: In total, 40 healthy male Sprague-Dawley (SD) rats of clean grade with body weights between 250 g and 300 g were randomly divided into an experimental and control group, with 20 rats per group. Five time points were set, including the 3 < sup > rd < /sup > , 7 < sup > th < /sup > , 14 < sup > th < /sup > , 21 < sup > st < /sup > and 28 < sup > th < /sup > days after surgery. In the experimental group, reversed autologous transplantation of the sciatic nerve was performed, while in the control group, the sciatic nerve was simply exposed without autologous transplantation. At the different time points, changes in the rat footprints were observed, the sciatic functional index (SFI) was calculated, changes in the regeneration of the myelin sheath at the nerve end after transplantation were observed by transmission electron microscopy, changes in type II NRG-1 protein expression were detected by a western blot analysis, and changes in type II NRG-1 mRNA expression were detected by real-time PCR. RESULTS: The SFI in the experimental group was lower than that in the control group at all time points after surgery, and the SFI in the experimental group gradually increased; these differences were statistically significant (p < 0.05). The expression of type II NRG-1 protein in the experimental group was significantly increased on the 3rd day after nerve transplantation and peaked on the 7 < sup > th < /sup > day, which continued until the 28 < sup > th < /sup > day after surgery, indicating a significant difference from the control group (p < 0.01). NRG-1 mRNA expression was markedly increased on the 7th day after nerve transplantation, further increased, and peaked on the 14 < sup > th < /sup > day (p < 0.01). The area of medullated nerve fibers (?m2) in the experimental group significantly differed from that in the control group on the 7 < sup > th < /sup > , 14 < sup > th < /sup > , 21 < sup > st < /sup > and 28 < sup > th < /sup > days (p < 0.01), and the diameters of the axons in the experimental group notably differed from those in the control group on the 7 < sup > th < /sup > , 14 < sup > th < /sup > and 21 < sup > st < /sup > days (p < 0.01). CONCLUSION: Type II NRG-1 expression peaked between the 3 < sup > rd < /sup > day and 14 < sup > th < /sup > day after autologous nerve transplantation and is likely involved in the regulation of myelin sheath regeneration during this period.

All-trans retinoic acid upregulates the expression of ciliary neurotrophic factor in retinal pigment epithelial cells.

Retinopathy of prematurity, a leading cause of visual impairment in low birth-weight infants, remains a crucial therapeutic challenge. Ciliary neurotrophic factor (CNTF) is a promyelinating trophic factor that promotes rod and cone photoreceptor survival and cone outer segment regeneration in the degenerating retina. Ciliary neurotrophic factor expression is regulated by many factors such as all-trans retinoic acid (ATRA). In this study, we found that ATRA increased CNTF expression in mouse retinal pigment epithelial (RPE) cells in a dose- and time-dependent manner, and PKA signaling pathway is necessary for ATRA-induced CNTF upregulation. Furthermore, we showed that ATRA promoted CNTF expression through CREB binding to its promoter region. In addition, CNTF levels were decreased in serum of retinopathy of prematurity children and in retinal tissue of oxygen-induced retinopathy mice. In mouse RPE cells cultured with high oxygen, CNTF expression and secretion were decreased, but could be recovered after treatment with ATRA. In conclusion, our data suggest that ATRA administration upregulates CNTF expression in RPE cells.

Expression of interferon regulatory factor 5 is regulated by the Sp1 transcription factor.

The transcription factor, interferon regulatory factor 5 (IRF5), is important in the induction of type I interferon, proinflammatory cytokines and chemokines, and is involved in autoimmune diseases and tumourigenesis. However, the mechanisms underlying the transcriptional regulation of wild­type IRF5 remain to be fully elucidated. The present study was primarily designed to clarify whether specificity protein 1 (Sp1) was involved in the regulation of IRF5. Initially, the IRF5 promoter region was cloned and its promoter activity was examined using Hela and HEK 293 cells. Deletion analyses revealed that the region spanning ­179 to +62 was the minimal promoter of IRF5. Bioinformatics analyses showed that this region contained three putative Sp1 binding sites, and mutational analyses revealed that all the Sp1 sites contributed to transcriptional activity. Secondly, the overexpression of Sp1 was found to increase the activity of the IRF5 promoter and the mRNA level of IRF5, determined using reporter gene assays and polymerase chain reaction analysis, respectively. By contrast, treatment with mithramycin and Sp1 small interfering RNA significantly reduced the activity of the IRF5 promoter and the mRNA level of IRF5. Finally, the results of an electrophoretic mobility shift assay and a chromatin immunoprecipitation assay demonstrated that Sp1 bound to the promoter region of IRF5 in vitro and in vivo. These results suggested that the Sp1 transcription factor is the primary determinant for activating the basal transcription of the IRF5.

E3 ubiquitin ligase Cbl-b suppresses human ORMDL3 expression through STAT6 mediation.

Orosomucoid 1-Like Protein 3 (ORMDL3) is an asthma candidate gene and Casitas B lineage lymphoma b (Cbl-b), an E3 ubiquitin ligase, is a critical factor in maintaining airway immune tolerance. However, the association of Cbl-b with ORMDL3 for asthma is unclear. Here, we show that expression of ORMDL3 is significantly increased and shows a strong linear correlation with decreased Cbl-b in the peripheral blood of recurrent wheeze patients. To elucidate the molecular mechanisms underlying this correlation, we identified that Cbl-b suppressed the transcriptional activity and mRNA expression of ORMDL3 in vivo. Further investigation showed that phosphorylation of signal transducer and activator of transcription 6 (STAT6) was induced by interleukin 4 bound to the ORMDL3 promoter, while Cbl-b reduced the phosphorylation of STAT6. Our results show that Cbl-b suppresses human ORMDL3 expression through STAT6.

Analysis of differentially expressed genes based on microarray data of glioma.

Glioma represents one of the main causes of cancer-related death worldwide. Unfortunately, its exact molecular mechanisms remain poorly understood, which limits the prognosis and therapy. This study aimed to identify the critical genes, transcription factors and the possible biochemical pathways that may affect glioma progression at transcription level. After downloading micro-array data from Gene Expression Omnibus (GEO), the differentially expressed genes (DEGs) between glioma and normal samples were screened. We predicted novel glioma-related genes and carried on online software DAVID to conduct GO enrichment and transcription factor analysis of these selected genes. String software was applied to construct a PPI protein interaction network, as well as to find the key genes and transcription factors in the regulation of glioma. A total of 97 DEGs were identified associated with cancer, the GO enrichment analysis indicated these DEGs were mainly relevant to immune responses as well as regulation of cell growth. In addition, the transcription factor analysis showed these DEGs were regulated by the binding sites of transcription factors GLI2, SP1, SMAD7, SMAD3, RELA, STAT5B, CTNNB1, STAT5A, TFAP2A and SP3. PPI protein interaction network analysis demonstrated the hub nodes in the interaction network were EGFR, TGFB1, FN1 and MYC. The hub DEGs may be the most critical in glioma and could be considered as drug targets for glioma therapy after further exploration. Besides, with the identification of regulating transcription factors, the pathogenesis of glioma at transcription level might be brought to light.