GDNF triggers proliferation of rat C6 glioma cells via the NF-κB/CXCL1 signaling pathway.

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor that is characterized by its high proliferative and migratory potential, leading to a high invasiveness of this tumor type. However, the underlying mechanism of GBM proliferation and migration has not been fully elucidated. In this study, at first, we used RNA-seq together with bioinformatics technology to screen for C-X-C motif ligand 1 (CXCL1) as a proliferation-related gene. And exogenous glial cell line-derived neurotrophic factor (GDNF) induced proliferation and up-regulated the level of CXCL1 in rat C6 glioma cells determined by sqPCR and ELISA. Then, we manipulated the CXCL1 expression by using a lentiviral vector (CXCL1-RNAi) approach. By this, the proliferation of C6 cells was decreased, suggesting that CXCL1 plays a key role in proliferation in these cells. We hypothesized that exogenous GDNF promoted NF-κB nuclear translocation and therefore, analyzed the interaction of CXCL1 with NF-κB by Western Blot and immunofluorescence. Additionally, we used BAY 11-7082, a phosphorylation inhibitor of NF-κB, to elucidate NF-κB mediated the effect of GDNF on CXCL1. These results demonstrated that GDNF enhanced the proliferation of rat C6 glioma cells through activating the NF-κB/CXCL1 signaling pathway. In summary, these studies not only revealed the mechanism of action of exogenous GDNF in promoting the proliferation of C6 glioma cells but may also provide a new biological target for the treatment of malignant glioma.

Dephosphorylation of Six2Y129 protects tyrosine hydroxylase-positive cells in SNpc by regulating TEA domain 1 expression.

Parkinson's disease (PD) is a neurodegenerative disease characterized by selective loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). We recently reported that Six2 could reverse the degeneration of DA neurons in a dephosphorylation state. Here we further identified that Eya1 was the phosphatase of Six2 that could dephosphorylate the tyrosine 129 (Y129) site by forming a complex with Six2 in damaged DA cells. Dephosphorylated Six2 then translocates from the cytoplasm to the nucleus. Using ChIP-qPCR and dual luciferase assay, we found that dephosphorylated Six2 down-regulates TEA domain1 (Tead1) expression, thus inhibiting 6-hydroxydopamine (6-OHDA)-induced apoptosis in DA cells. Furthermore, we showed Six2Y129F/Tead1 signaling could protect against the loss of SNpc tyrosine hydroxylase-positive (TH+) cells and improve motor function in PD model rats. Our results demonstrate a dephosphorylation-dependent mechanism of Six2 that restores the degeneration of DA neurons, which could represent a potential therapeutic target for PD.

SKAP1 Is a Novel Biomarker and Therapeutic Target for Gastric Cancer: Evidence from Expression, Functional, and Bioinformatic Analyses.

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide. Due to the lack of early symptoms, GC is often diagnosed at an advanced stage when treatment options are limited. There is an urgent need to identify biomarkers for early detection, prognosis evaluation, and targeted treatment of GC. Studies have shown that Src kinase-associated phosphoprotein 1 (SKAP1) promotes cell proliferation and invasion and is associated with poor prognosis in colorectal cancer, malignant fibrous histiocytoma, and breast cancer. However, the role and mechanism of SKAP1 in GC are unclear. Here, analyses of multiple databases and experiments revealed that SKAP1 expression was higher in GC than in adjacent normal tissues. The Cancer Genome Atlas data showed that high SKAP1 expression was associated with poor GC prognosis. SKAP1 expression was higher in GC than in normal gastric epithelial cells. SKAP1 silencing reduced the proliferation, migration and invasion of the GC cell lines MKN45 and HGC27. Rescue experiments suggest that SKAP1 may promote GC progression by activating JAK1/PI3K/AKT signaling and regulating GC cell proliferation, invasion, migration, and other functions. Bioinformatics analysis revealed that SKAP1 was associated with immune cell infiltration and checkpoint expression in GC. High SKAP1 expression was associated with poorer immunotherapy outcomes, suggesting its potential as a predictive biomarker of GC immunotherapy efficacy. In summary, SKAP1 is overexpressed in GC, where it promotes cell proliferation, invasion and migration and is associated with poor prognosis and poor immunotherapy outcomes. SKAP1 may represent a biomarker and therapeutic target in GC and regulates cellular functions through JAK1/PI3K/AKT signaling.

Single-nuclei RNA sequencing uncovers heterogenous transcriptional signatures in Parkinson's disease associated with nuclear receptor-related factor 1 defect.

Previous studies have found that deficiency in nuclear receptor-related factor 1 (Nurr1), which participates in the development, differentiation, survival, and degeneration of dopaminergic neurons, is associated with Parkinson's disease, but the mechanism of action is perplexing. Here, we first ascertained the repercussion of knocking down Nurr1 by performing liquid chromatography coupled with tandem mass spectrometry. We found that 231 genes were highly expressed in dopaminergic neurons with Nurr1 deficiency, 14 of which were linked to the Parkinson's disease pathway based on Kyoto Encyclopedia of Genes and Genomes analysis. To better understand how Nurr1 deficiency autonomously invokes the decline of dopaminergic neurons and elicits Parkinson's disease symptoms, we performed single-nuclei RNA sequencing in a Nurr1 LV-shRNA mouse model. The results revealed cellular heterogeneity in the substantia nigra and a number of activated genes, the preponderance of which encode components of the major histocompatibility II complex. Cd74, H2-Ab1, H2-Aa, H2-Eb1, Lyz2, Mrc1, Slc6a3, Slc47a1, Ms4a4b, and Ptprc2 were the top 10 differentially expressed genes. Immunofluorescence staining showed that, after Nurr1 knockdown, the number of CD74-immunoreactive cells in mouse brain tissue was markedly increased. In addition, Cd74 expression was increased in a mouse model of Parkinson's disease induced by treatment with 6-hydroxydopamine. Taken together, our results suggest that Nurr1 deficiency results in an increase in Cd74 expression, thereby leading to the destruction of dopaminergic neurons. These findings provide a potential therapeutic target for the treatment of Parkinson's disease.

Serum glial cell line-derived neurotrophic factor (GDNF) a potential biomarker of executive function in Parkinson's disease.

Objective: Evidence shows that the impairment of executive function (EF) is mainly attributed to the degeneration of frontal-striatal dopamine pathway. Glial cell line-derived neurotrophic factor (GDNF), as the strongest protective neurotrophic factor for dopaminergic neurons (DANs), may play a role in EF to some extent. This study mainly explored the correlation between serum GDNF concentration and EF performance in Parkinson's disease (PD). Methods: This study recruited 45 healthy volunteers (health control, HC) and 105 PD patients, including 44 with mild cognitive impairment (PD-MCI), 20 with dementia (PD-D), and 20 with normal cognitive function (PD-N). Neuropsychological tests were performed to evaluate EF (working memory, inhibitory control, and cognitive flexibility), attention, language, memory, and visuospatial function. All subjects were tested for serum GDNF and homovanillic acid (HVA) levels by ELISA and LC-ESI-MS/MS, respectively. Results: PD-MCI patients showed impairments in the trail making test (TMT) A (TMT-A), TMT-B, clock drawing test (CDT) and semantic fluency test (SFT), whereas PD-D patients performed worse in most EF tests. With the deterioration of cognitive function, the concentration of serum GDNF and HVA in PD patients decreased. In the PD group, the serum GDNF and HVA levels were negatively correlated with TMT-A (r GDNF = -0.304, P < 0.01; r HVA = -0.334, P < 0.01) and TMT-B (r GDNF = -0.329, P < 0.01; r HVA = -0.323, P < 0.01) scores. Serum GDNF levels were positively correlated with auditory verbal learning test (AVLT-H) (r = 0.252, P < 0.05) and SFT (r = 0.275, P < 0.05) scores. Serum HVA levels showed a positively correlation with digit span test (DST) (r = 0.277, P < 0.01) scores. Stepwise linear regression analysis suggested that serum GDNF and HVA concentrations and UPDRS-III were the influence factors of TMT-A and TMT-B performances in PD patients. Conclusion: The decrease of serum GDNF concentration in PD patients was associated with impaired inhibitory control, cognitive flexibility, and attention performances. The changes of GDNF and HVA might synergistically participate in the occurrence and development of executive dysfunction in PD patients.

Blunt dopamine transmission due to decreased GDNF in the PFC evokes cognitive impairment in Parkinson's disease.

Studies have found that the absence of glial cell line-derived neurotrophic factor may be the primary risk factor for Parkinson's disease. However, there have not been any studies conducted on the potential relationship between glial cell line-derived neurotrophic factor and cognitive performance in Parkinson's disease. We first performed a retrospective case-control study at the Affiliated Hospital of Xuzhou Medical University between September 2018 and January 2020 and found that a decreased serum level of glial cell line-derived neurotrophic factor was a risk factor for cognitive disorders in patients with Parkinson's disease. We then established a mouse model of Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and analyzed the potential relationships among glial cell line-derived neurotrophic factor in the prefrontal cortex, dopamine transmission, and cognitive function. Our results showed that decreased glial cell line-derived neurotrophic factor in the prefrontal cortex weakened dopamine release and transmission by upregulating the presynaptic membrane expression of the dopamine transporter, which led to the loss and primitivization of dendritic spines of pyramidal neurons and cognitive impairment. In addition, magnetic resonance imaging data showed that the long-term lack of glial cell line-derived neurotrophic factor reduced the connectivity between the prefrontal cortex and other brain regions, and exogenous glial cell line-derived neurotrophic factor significantly improved this connectivity. These findings suggested that decreased glial cell line-derived neurotrophic factor in the prefrontal cortex leads to neuroplastic degeneration at the level of synaptic connections and circuits, which results in cognitive impairment in patients with Parkinson's disease.

Long non-coding RNA: Multiple effects on the differentiation, maturity and cell function of dendritic cells.

Long non-coding RNAs (LncRNAs), lacking protein-coding function, modulate immune function by regulating the expression of genes or the function of protein molecules. They participate in epigenetic regulation, interfere with downstream gene transcription acting as a molecular sponge to affect miRNA function, and can combine with proteins to form nucleic acid protein complexes that affect protein function or cell location to regulate genes and regulate immune function. LncRNAs are differentially expressed in immune cells. They affect the maturity, differentiation and activation of immune cells and regulate cytokine release and immune phenotype. They are closely related to immune tolerance and cell migration. Dendritic cells (DCs) are important immune cells with the most robust antigen-presenting function, and have irreplaceable roles in human innate immunity and adaptive immunity. Emerging evidence over the past few years has suggested that LncRNAs influence the differentiation and maturation of DCs and serve as a critical role in the cell phenotype and immune function of DCs. To further understand the role of LncRNAs in the occurrence and development of DC-related diseases, we elaborated the role of LncRNAs in DC immune function, including antigen presentation, T cell activation and proliferation, DC migration. Furthermore, we summarized the impact of pathological factors (tumors, inflammation, autoimmune disease, viral infection) and physiological factors (e.g., age) on the LncRNAs in DCs, and how the changed LncRNAs altered the function and behavior of DCs resulting from the intervention. We hope this review give us have a better understanding of multiple effects of LncRNA on cell function in DCs.

Effects of STAT3 Inhibitor BP-1-102 on The Proliferation, Invasiveness, Apoptosis and Neurosphere Formation of Glioma Cells in Vitro.

Malignant glioma, especially glioblastoma (GBM), has historically been associated with a low survival rate. The hyperactivation of STAT3 played a key role in GBM initiation and resistance to therapy; thus, there is an urgent requirement for novel STAT3 inhibitors. BP-1-102 was recently reported as a biochemical inhibitor of STAT3, but its roles and mechanism in biological behavior of glioma cells were still unclear. In this study, the effects of BP-1-102 on proliferation, apoptosis, invasion and neurosphere formation of glioma cell were investigated. Our results indicated that BP-1-102 inhibited the proliferation of U251 and A172 cells, and their IC50 values were 10.51 and 8.534 µM, respectively. Furthermore, BP-1-102 inhibited the invasion and migration abilities of U251 and A172 cells by decreasing the expression of matrix metallopeptidase 9, and induced glioma cell apoptosis by decreasing the expression of B-cell lymphoma-2. BP-1-102 also inhibited the formation of neurosphere. Mechanically, BP-1-102 reduced the phosphorylation of STAT3 and the p-STAT3's nuclear translocation in glioma cells. Thus, this study herein provided a potential drug for glioma therapy.

How to overcome tumor resistance to anti-PD-1/PD-L1 therapy by immunotherapy modifying the tumor microenvironment in MSS CRC.

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death-1/anti-programmed cell death ligand-1 (anti-PD-1/PD-L1) therapy, have elicited impressive clinical outcomes in several malignancies. This is regarded as a pivotal breakthrough in cancer treatment. However, a vast majority of colorectal cancer (CRC) cases are microsatellite stable (MSS) and respond poorly to anti-PD-1/PD-L1 immunotherapies. Since ICIs serve as rescuers for immune cell-mediated cancer cell elimination, the limited efficacy of anti-PD-1/PD-L1 treatments may be attributed to the privileged tumor microenvironment (TME), which is characterized by unavailable immunosurveillance. Thus, it is essential to modify the pre-existing disordered immune system prior to the application of an anti-PD-1/PD-L1 therapy. In this review, to overcome unsatisfactory immunotherapy in CRC patients with MSS, we discussed various combination therapies based on TME reconstruction for improving the susceptibility to anti-PD-1/PD-L1 treatment.

Role, function and regulation of the thymocyte selection-associated high mobility group box protein in CD8+ T cell exhaustion.

Thymocyte selection-associated high mobility group box protein (TOX), a member of the high-motility group box (HMG) protein superfamily, is an evolutionarily conserved DNA-binding protein. It functions as a transcription factor that modulates transcriptional programs by binding to DNA in a structure-dependent manner. It has been well established that TOX is required for the development of CD4+ T cells, natural killer (NK) cells and innate lymphoid cells (ILCs), as well as the autoimmunity mediated by CD8+ T cells. Recently, emerging evidence supports an essential role for TOX in the induction of T cell exhaustion in the setting of tumor or chronic viral infection by mediating transcriptional and epigenetic changes, which are cardinal hallmarks of exhausted T cells. Moreover, TOX plays a key role in the persistence of antigen-specific T cells and in the mitigation of tissue damage caused by immunopathology over the course of tumorigenesis and chronic infection. Additionally, TOX contributes to the high level of programmed cell death protein 1 (PD-1) on the cell surface by participating in the process of endocytic recycling of PD-1. In this review, we summarize the most recent information about the role of TOX in the process of T cell exhaustion, which enriches our understanding of the molecular mechanisms of CD8+ T cell exhaustion upon chronic antigen stimulation and reveals promising therapeutic targets for persisting infection and cancer.

Wnt/ß­catenin signaling: Causes and treatment targets of drug resistance in colorectal cancer (Review).

Colorectal cancer (CRC) is the third most common malignant tumor in humans. Chemotherapy is used for the treatment of CRC. However, the effect of chemotherapy remains unsatisfactory due to drug resistance. Growing evidence has shown that the presence of highly metastatic tumor stem cells, regulation of non­coding RNAs and the tumor microenvironment contributes to drug resistance mechanisms in CRC. Wnt/ß­catenin signaling mediates the chemoresistance of CRC in these three aspects. Therefore, the present study analyzed the abundant evidence of the contribution of Wnt/ß­catenin signaling to the development of drug resistance in CRC and discussed its possible role in improving the chemosensitivity of CRC, which may provide guidelines for its clinical treatment.

Apatinib regulates the growth of gastric cancer cells by modulating apoptosis and autophagy.

Apatinib is a novel, highly selective small-molecule inhibitor of the tyrosine kinase VEGFR-2. Although its safety and efficacy in the treatment of advanced gastric cancer (GC) and other solid tumors have been confirmed, the precise molecular mechanism underlying its efficacy remains unclear. The purpose of this study was to investigate the mechanism by which apatinib regulates the biological functions of GC cells in vitro. The CCK-8 assay was used to detect the inhibitory effect of apatinib at different concentrations on the proliferation of SGC7901 and MKN45 human GC cells. The effects of apatinib on apoptosis, autophagy, and cell cycle-related genes in SGC7901 and MKN45 cells were detected by Western blotting and real-time quantitative PCR (RT-qPCR). JC-1 staining, flow cytometry, Hoechst 33342 staining, dansylcadaverine (MDC) staining, and Transwell assays were used to detect the effects of apatinib on apoptosis, the cell cycle, autophagy, and invasion and migration capacities, respectively, in SGC7901 and MKN45 cells. The inhibitory effect of apatinib on the proliferation of GC cells was dependent on concentration. Apatinib significantly promoted apoptosis and autophagy. It also altered the cell cycle distribution and inhibited the invasion and migration of GC cells. In general, apatinib inhibited the proliferation of GC cells by promoting apoptosis and autophagy, regulating the cell cycle and inhibiting the invasion and migration capacities of GC cells.

Possible role of glial cell line-derived neurotrophic factor for predicting cognitive impairment in Parkinson's disease: a case-control study.

Glial cell line-derived neurotrophic factor (GDNF) plays an important role in the protection of dopaminergic neurons, but there are few reports of the relationship between GDNF and its precursors (α-pro-GDNF and ß-pro-GDNF) and cognitive impairment in Parkinson's disease. This study aimed to investigate the relationship between the serum levels of GDNF and its precursors and cognitive impairment in Parkinson's disease, and to assess their potential as a diagnostic marker. Fifty-three primary outpatients and hospitalized patients with Parkinson's disease (23 men and 30 women) with an average age of 66.58 years were enrolled from the Affiliated Hospital of Xuzhou Medical University of China in this case-control study. The patients were divided into the Parkinson's disease with cognitive impairment group (n = 27) and the Parkinson's disease with normal cognitive function group (n = 26) based on their Mini-Mental State Examination, Montreal Cognitive Assessment, and Clinical Dementia Rating scores. In addition, 26 age- and sex-matched healthy subjects were included as the healthy control group. Results demonstrated that serum GDNF levels were significantly higher in the Parkinson's disease with normal cognitive function group than in the other two groups. There were no significant differences in GDNF precursor levels among the three groups. Correlation analysis revealed that serum GDNF levels, GDNF/α-pro-GDNF ratios, and GDNF/ß-pro-GDNF ratios were moderately or highly correlated with the Mini-Mental State Examination, Montreal Cognitive Assessment, and Clinical Dementia Rating scores. To explore the risk factors for cognitive impairment in patients with Parkinson's disease, logistic regression analysis and stepwise linear regression analysis were performed. Both GDNF levels and Hoehn-Yahr stage were risk factors for cognitive impairment in Parkinson's disease, and were the common influencing factors for cognitive scale scores. Neither α-pro-GDNF nor ß-pro-GDNF was risk factors for cognitive impairment in Parkinson's disease. A receiver operating characteristic curve of GDNF was generated to predict cognitive function in Parkinson's disease (area under the curve = 0.859). This result indicates that the possibility that serum GDNF can correctly distinguish whether patients with Parkinson's disease have cognitive impairment is 0.859. Together, these results suggest that serum GDNF may be an effective diagnostic marker for cognitive impairment in Parkinson's disease. However, α-pro-GDNF and ß-pro-GDNF are not useful for predicting cognitive impairment in this disease. This study was approved by Ethics Committee of the Affiliated Hospital of Xuzhou Medical University, China (approval No. XYFY2017-KL047-01) on November 30, 2017.

[Local injection of BTX-A prevents iatrogenic anterior urethral stricture in rabbits].

OBJECTIVE: To investigate the preventive effect of local injection of botulinum toxin type A (BTX-A) against iatrogenic anterior urethral stricture (IAUS) in New Zealand male rabbits. METHODS: Sixteen adult New Zealand male rabbits were randomly divided into an experimental and a control group of equal number. The model of IAUS was established in the rabbits by incision of the ventral urethra of the penile segment and electrocoagulation of the urethral mucosa. The rabbits of the experimental group were injected with 10 U of BTX-A solution and those of the control group with 1.0 ml of normal saline into the electrocoagulated submucosa of the urethra. At 30 days after modeling, retrograde urethrography was performed and the scarred urethral tissue harvested for HE and Masson staining. RESULTS: No systemic symptoms of botulinum toxin poisoning were observed in either group of the rabbits. Retrograde urethrography showed statistically significant differences between the control and experimental groups in the diameter of the urethra (ï¼»0.15 ± 0.08ï¼½ vs ï¼»0.50 ± 0.23ï¼½ cm, P < 0.05) and the stenosis ratio (3.68 ± 1.22 vs 1.29 ± 0.15, P < 0.05). Urethrography revealed obvious hyperplasia and contracture of urethral scar with high bulge and narrow urethral cavity, while HE and Masson staining exhibited absence or discontinuity of the urethral epithelium, submucosal fibrosis with infiltration of a large number of fibroblasts, and hyperplasia and thickening of collagen fibers (blue) in the control group. All the changes above were slight and the urethral epithelium was continuous in the experimental group. CONCLUSIONS: Local injection of BTX-A reduced the incidence of iatrogenic anterior urethral stricture after iatrogenic acute heat injury in New Zealand male rabbits.

Down-Regulated CUEDC2 Increases GDNF Expression by Stabilizing CREB Through Reducing Its Ubiquitination in Glioma.

Abnormally high expression of glial cell line-derived neurotrophic factor (GDNF) derived from glioma cells has essential impacts on gliomagenesis and development, but the molecular basis underlying increased GDNF expression in glioma cells remain unclear. This work aimed to study the molecular mechanisms that may explain the accumulation of GDNF in glioma. Firstly, we observed that cAMP response element-binding protein (CREB), known as an important transcription factor for binding of GDNF promoter region, was highly expressed with an apparent accumulation into the nucleus of glioma cells, which may contribute to the transcription of GDNF. Secondly, CUE domain-containing protein 2 (CUEDC2), a ubiquitin-regulated protein, could increase the amount of binding between the E3 ligase tripartite motif-containing 21 (TRIM21) and CREB and affect the CREB level. Like our previous study, it showed that there was a significantly down-regulation of CUEDC2 in glioma. Finally, our data suggest that GDNF expression is indirectly regulated by transcription factor ubiquitination. Indeed, down-regulation of CUEDC2, decreased the ubiquitination and degradation of CREB, which was associated to high levels of GDNF. Furthermore, abundant CREB involved in the binding to the GDNF promoter region contributes to GDNF high expression in glioma cells. Collectively, it was verified the GDNF expression was affected by CREB ubiquitination regulated by CUEDC2 level.

Circular RNAs in gastrointestinal cancer: Current knowledge, biomarkers and targeted therapy (Review).

Circular RNAs (circRNAs) are a type of endogenous non­coding RNAs that are connected at the 3' and 5' ends by exon or intron cyclization, which forms a covalently closed loop. They are stable, well conserved, exhibit specific expression in mammalian cells and can function as microRNA (miRNA or miR) sponges to regulate the target genes of miRNAs, which influences biological processes. Such as tumor proliferation, invasion, metastasis, apoptosis and tumor stage. circRNAs represent promising candidates for clinical diagnosis and treatment. In the present review, the biogenesis, classification and functions of circRNAs in tumors are briefly summarized and discussed. In addition, the participation of circRNAs in signal transduction pathways regulating gastrointestinal cancer cellular functions is highlighted.

Non­coding RNAs that regulate the Wnt/ß­catenin signaling pathway in gastric cancer: Good cop, bad cop? (Review).

Gastric cancer (GC) is one of the most common causes of cancer­related mortality worldwide. Despite remarkable progress in the diagnosis and treatment of GC, a large number of cases are diagnosed as advanced GC, and treatment failure occurs. Emerging evidence has shown that non­coding RNAs (ncRNAs), especially microRNAs (miRNAs) and long non­coding RNAs (lncRNAs), play a vital role in the tumorigenesis and development of GC. Moreover, the pathogenesis of GC is closely related to aberrant activation of the Wnt (Wingless­type MMTV integration site family) signaling pathway. ncRNAs serve as potential novel biomarkers in the clinical examination, prognosis and therapeutic targeting of GC. Furthermore, dysregulation of ncRNAs has been demonstrated to affect tumor initiation, epithelial­mesenchymal transition (EMT), angiogenesis, tumor development, invasion, metastasis and resistance to therapy via the Wnt/ß­catenin signaling pathway. This review focuses on the role of ncRNAs in modulating the Wnt/ß­catenin signaling pathway in the pathogenesis of GC, which may provide a reference for the clinical diagnosis and treatment of GC.

miR-155 indicates the fate of CD4+ T cells.

MicroRNAs (miRNAs) are a class of short noncoding RNAs that regulate the translation of target messenger RNA (mRNA) and consequently participate in a variety of biological processes at the posttranscriptional level. miR-155, encoded within a region known as the B cell integration cluster (BIC), plays multifunctional roles in shaping lymphocytes ranging from biological development to adaptive immunity. It has been revealed that miR-155 plays a key role in fine-tuning the regulation of lymphocyte subsets, including dendritic cells (DCs), macrophages, B cells, and CD8+ and CD4+ T cells. Antigen-specific CD4+ T lymphocytes are critical for host defense against pathogens and prevention of damage resulting from excessive inflammation. Over the past years, various studies have shown that miR-155 plays a critical role in CD4+ T cells function. Therefore, we summarize multiple target genes of miR-155 that regulate aspects of CD4+ T cells immunity, particularly CD4+ T cells differentiation, in this review. In addition, we also focus on the role of miR-155 in the regulation of immunological diseases, suggesting it as a potential disease biomarker and therapeutic target.

miRNA-5119 regulates immune checkpoints in dendritic cells to enhance breast cancer immunotherapy.

Dendritic cell (DC) based immunotherapy is a promising approach to clinical cancer treatment. miRNAs are a class of small non-coding RNA molecules that bind to RNAs to mediate multiple events which are important in diverse biological processes. miRNA mimics and antagomirs may be potent agents to enhance DC-based immunotherapy against cancers. miRNA array analysis was used to identify a representative miR-5119 potentially regulating PD-L1 in DCs. We evaluated levels of ligands of immune cell inhibitory receptors (IRs) and miR-5119 in DCs from immunocompetent mouse breast tumor-bearing mice, and examined the molecular targets of miR-5119. We report that miRNA-5119 was downregulated in spleen DCs from mouse breast cancer-bearing mice. In silico analysis and qPCR data showed that miRNA-5119 targeted mRNAs encoding multiple negative immune regulatory molecules, including ligands of IRs such as PD-L1 and IDO2. DCs engineered to express a miR-5119 mimic downregulated PD-L1 and prevented T cell exhaustion in mice with breast cancer homografts. Moreover, miR-5119 mimic-engineered DCs effectively restored function to exhausted CD8+ T cells in vitro and in vivo, resulting in robust anti-tumor cell immune response, upregulated cytokine production, reduced T cell apoptosis, and exhaustion. Treatment of 4T1 breast tumor-bearing mice with miR-5119 mimic-engineered DC vaccine reduced T cell exhaustion and suppressed mouse breast tumor homograft growth. This study provides evidence supporting a novel therapeutic approach using miRNA-5119 mimic-engineered DC vaccines to regulate inhibitory receptors and enhance anti-tumor immune response in a mouse model of breast cancer. miRNA/DC-based immunotherapy has potential for advancement to the clinic as a new strategy for DC-based anti-breast cancer immunotherapy.

MES23.5 DA Immortalized Neuroblastoma Cells Self-protect Against Early Injury by Overexpressing Glial Cell-derived Neurotrophic Factor via Akt1/Eya1/Six2 Signaling.

Injured neurons can initiate their own neurotoxin-induced repair mechanisms by expressing protective genes and activating specific intracellular signal transduction pathways. Although glial cell-derived neurotrophic factor (GDNF) plays a key role in the repair of dopaminergic (DA) neurons, whether there is high expression of GDNF in DA neurons at an early stage of injury has not yet been reported. In this study, neurotoxin-induced GDNF overexpression was detected for the first time in MES23.5 DA immortalized neuroblastoma (MES23.5 DA) cells soon after 6-hydroxydopamine (6-OHDA) treatment. We also observed that the phosphorylation of Akt1, a member of the protein kinase B family, was increased. Further studies showed that activated Akt1 increased the phosphorylation of the protein phosphatase Eya1, which is a member of the eyes absent (Eya) family of transcriptional cofactors. Then, activated Eya1 decreased the phosphorylation of the sine oculis-related homeobox 2 (Six2) transcription factor. In addition, chromatin immunoprecipitation coupled with quantitative polymerase chain reaction (ChIP-qPCR) revealed that Six2 promoted GDNF transcription in MES23.5 DA cells by directly binding to the GDNF promoter. Finally, we showed that inhibiting neurotoxin-induced GDNF overexpression increased MES23.5 DA cell death, while promoting GDNF expression via Six2 overexpression decreased DA neuronal death. These results suggest that MES23.5 DA cells with early 6-OHDA-induced injury can promote the overexpression of GDNF by activating the Akt1/Eya1/Six2 signaling pathway, and this overexpression of GDNF has protective effects on injured MES23.5 DA cells. Hence, this study highlights a new target for drug development for the treatment of Parkinson's disease.