Netrin-1 signaling pathway mechanisms in neurodegenerative diseases

Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development.Their profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic function.Increasing amounts of evidence highlight several key points:(1)Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer’s disease and Parkinson’s disease,and potentially,similar alterations occur in humans.(2)Genetic mutations of Netrin-1 receptors increase an individuals’susceptibility to neurodegenerative disorders.(3)Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function.(4)Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of cancers.These findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative diseases.Through a comprehensive review of Netrin-1 signaling pathways,our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.

Hepatitis C virus core protein-induced miR-93-5p upregulation inhibits interferon signaling pathway by targeting IFNAR1

AIM To investigate the mechanism by which hepatitis C virus(HCV) core protein-induced mi R-93-5 p up-regulation regulates the interferon(IFN) signaling pathway.METHODS HCV-1 b core protein was exogenously expressed in Huh7 cells using pc DNA3.1(+) vector. The expression of mi R-93-5 p and interferon receptor 1(IFNAR1) was measured using quantitative reverse transcriptionpolymerase chain reaction and Western blot. The protein expression and phosphorylation level of STAT1 were evaluated by Western blot. The overexpression and silencing of mi R-93-5 p and IFNAR1 were performed using mi R-93-5 p agomir and antagomir, and pc DNA3.1-IFNAR1 and IFNAR1 si RNA, respectively. Luciferase assay was used to identify whether IFNAR1 is a target of mi R-93-5 p. Cellular experiments were also conducted.RESULTS Serum mi R-93-5 p level was increased in patients with HCV-1 b infection and decreased to normal level after HCV-1 b clearance, but persistently increased in those with pegylated interferon-α resistance, compared with healthy subjects. Serum mi R-93-5 p expression had an AUC value of 0.8359 in distinguishing patients with pegylated interferon-α resistance from those with pegylated interferon-α sensitivity. HCV-1 b core protein increased mi R-93-5 p expression and induced inactivation of the IFN signaling pathway in Huh7 cells. Furthermore, IFNAR1 was identified as a direct target of mi R-93-5 p, and IFNAR1 restore could rescue mi R-93-5 p-reduced STAT1 phosphorylation, suggesting that the mi R-93-5 p-IFNAR1 axis regulates the IFN signaling pathway.CONCLUSION HCV-1 b core protein-induced mi R-93-5 p up-regulation inhibits the IFN signaling pathway by directly targeting IFNAR1, and the mi R-93-5 p-IFNAR1 axis regulates STAT1 phosphorylation. This axis may be a potential therapeutic target for HCV-1 b infection.

MiR-146a-5p targeting SMAD4 and TRAF6 inhibits adipogenensis through TGF-β and AKT/mTORC1 signal pathways in porcine intramuscular preadipocytes

Background: Intramuscular fat(IMF) content is a vital parameter for assessing pork quality. Increasing evidence has shown that microRNAs(miRNAs) play an important role in regulating porcine IMF deposition. Here, a novel miRNA implicated in porcine IMF adipogenesis was found, and its effect and regulatory mechanism were further explored with respect to intramuscular preadipocyte proliferation and differentiation.Results: By porcine adipose tissue miRNA sequencing analysis, we found that miR-146a-5p is a potential regulator of porcine IMF adipogenesis. Further studies showed that miR-146a-5p mimics inhibited porcine intramuscular preadipocyte proliferation and differentiation, while the miR-146a-5p inhibitor promoted cell proliferation and adipogenic differentiation. Mechanistically, miR-146a-5p suppressed cell proliferation by directly targeting SMAD family member 4(SMAD4) to attenuate TGF-β signaling. Moreover, miR-146a-5p inhibited the differentiation of intramuscular preadipocytes by targeting TNF receptor-associated factor 6(TRAF6) to weaken the AKT/mTORC1 signaling downstream of the TRAF6 pathway.Conclusions: MiR-146a-5p targets SMAD4 and TRAF6 to inhibit porcine intramuscular adipogenesis by attenuating TGF-β and AKT/mTORC1 signaling, respectively. These findings provide a novel miRNA biomarker for regulating intramuscular adipogenesis to promote pork quality.

Angelica sinensis polysaccharides ameliorate 5-flourouracil-induced bone marrow stromal cell proliferation inhibition via regulating Wnt/β-catenin signaling

Chemotherapy may cause cellular oxidative stress to bone marrow.Oxidative damage of bone marrow hematopoietic microenvironment is closely related to chronic myelosuppression after chemotherapeutic treatment.Angelica sinensis polysaccharides(ASP)are major effective ingredients of traditional Chinese medicine Angelica with multi-target anti-oxidative stress features.In the current study,we investigated the protective roles and mechanisms of ASP on chemotherapy-induced bone marrow stromal cell(BMSC)damage.The human bone marrow stromal cell line HS-5 cells were divided into control group,5-FU group,5-FU+ASP group,and 5-FU+LiCl group to investigate the mechanism of ASP to alleviate 5-FU-induced BMSC proliferation inhibition.The results showed that 5-FU inhibits the growth of HS-5 cells in a time and dose-dependent manner;however,ASP partially counteracted the 5-FU-induced decrease in cell viability,whereas Wnt signaling inhibitor Dkk1 antagonized the effect of ASP on HS-5 cells.ASP reversed the decrease in total cytoplasmicβ-catenin,p-GSK-3β,and CyclinD1 following 5-FU treatment and modulated nuclear expression ofβ-catenin,Lef-1,and C-myc proteins.Furthermore,ASP also enhanced the antioxidant capacity of cells and reduced 5-FU-induced oxidative stress,attenuated FoxO1 expression,thus weakened its downstream apoptosis-related proteins and G0/G1 checkpoint-associated p27^(Kip1) expression to alleviate 5-FU-induced apoptosis and to promote cell cycle progression.All the results above suggest that the protective role of ASP in 5-FU-treated BMSCs proliferation for the chemotherapy may be related to its activating Wnt/β-catenin signaling and keeping homeostasis betweenβ-catenin and FoxO1 under oxidative stress.The study provides a potential therapeutic strategy for alleviating chemotherapeutic damage on BMSCs.

Taurolidine improved protection against highly pathogenetic avian influenza H5N1 virus lethal-infection in mouse model by regulating the NF-κB signaling pathway

Taurolidine(TRD),a derivative of taurine,has anti-bacterial and anti-tumor effects by chemically reacting with cell-walls,endotoxins and exotoxins to inhibit the adhesion of microorganisms.However,its application in antiviral therapy is seldom reported.Here,we reported that TRD significantly inhibited the replication of influenza virus H5N1 in MDCK cells with the half-maximal inhibitory concentration(EC_(50))of 34.45μg/mL.Furthermore,the drug inhibited the amplification of the cytokine storm effect and improved the survival rate of mice lethal challenged with H5N1(protection rate was 86%).Moreover,TRD attenuated virus-induced lung damage and reduced virus titers in mice lungs.Administration of TRD reduced the number of neutrophils and increased the number of lymphocytes in the blood of H5N1 virus-infected mice.Importantly,the drug regulated the NF-κB signaling pathway by inhibiting the separation of NF-κB and IκBa,thereby reducing the expression of inflammatory factors.In conclusion,our findings suggested that TRD could act as a potential anti-influenza drug candidate in further clinical studies.

The IL-1R/TLR signaling pathway is essential for efficient CD8+ T-cell responses against hepatitis B virus in the hydrodynamic injection mouse model

The outcome of hepatitis B viral(HBV)infection is determined by the complex interactions between replicating HBV and the immune system.While the role of the adaptive immune system in the resolution of HBV infection has been studied extensively,the contribution of innate immune mechanisms remains to be defined.Here we examined the role of the interleukin-1 receptor/Toll-like receptor(IL-1R/TLR)signaling pathway in adaptive immune responses and viral clearance by exploring the HBV mouse model.Hydrodynamic injection with a replication-competent HBV genome was performed in wild-type mice(WT)and a panel of mouse strains lacking specific innate immunity component expression.We found higher levels of HBV protein production and replication in Tlr2^(−/−),Tlr23479^(−/−),3d/Tlr24^(−/−),Myd88/Trif^(−/−)and Irak4^(−/−)mice,which was associated with reduced HBV-specific CD8+T-cell responses in these mice.Importantly,HBV clearance was delayed for more than 2 weeks in 3d/Tlr24^(−/−),Myd88/Trif^(−/−)and Irak4^(−/−)mice compared to WT mice.HBV-specific CD8+T-cell responses were functionally impaired for producing the cytokines IFN-γ,TNF-αand IL-2 in TLR signaling-deficient mice compared to WT mice.In conclusion,the IL-1R/TLR signaling pathway might contribute to controlling HBV infection by augmenting HBV-specific CD8+T-cell responses.

Long noncoding RNA 1392 regulates MDA5 by interaction with ELAVL1 to inhibit coxsackievirus B5 infection

Long noncoding RNAs(lncRNAs)modulate many aspects of biological and pathological processes.Recent studies have shown that host lncRNAs participate in the antiviral immune response,but functional lncRNAs in coxsackievirus B5(CVB5)infection remain unknown.Here,we identified a novel cytoplasmic lncRNA,LINC1392,which was highly inducible in CVB5 infected RD cells in a time-and dose-dependent manner,and also can be induced by the viral RNA and IFN-β.Further investigation showed that LINC1392 promoted several important interferon-stimulated genes(ISGs)expression,including IFIT1,IFIT2,and IFITM3 by activating MDA5,thereby inhibiting the replication of CVB5 in vitro.Mechanistically,LINC1392 bound to ELAV like RNA binding protein 1(ELAVL1)and blocked ELAVL1 interaction with MDA5.Functional study revealed that the 245–835 nt locus of LINC1392 exerted the antiviral effect and was also an important site for ELAVL1 binding.In mice,LINC1392 could inhibit CVB5 replication and alleviated the histopathological lesions of intestinal and brain tissues induced by viral infection.Our findings collectively reveal that the novel LINC1392 acts as a positive regulator in the IFN-I signaling pathway against CVB5 infection.Elucidating the underlying mechanisms on how lncRNA regulats the host innate immunity response towards CVB5 infection will lay the foundation for antiviral drug research.

Splicing factor SF3B3,a NS5-binding protein,restricts ZIKV infection by targeting GCH1

Zika virus(ZIKV),a positive-sense single-stranded RNA virus,causes congenital ZIKV syndrome in children and Guillain-Barre Syndrome(GBS)in adults.ZIKV expresses nonstructural protein 5(NS5),a large protein that is essential for viral replication.ZIKV NS5 confers the ability to evade interferon(IFN)signalling;however,the exact mechanism remains unclear.In this study,we employed affinity pull-down and liquid chromatography-tandem mass spectrometry(LC-MS/MS)analyses and found that splicing factor 3b subunit 3(SF3B3)is associated with the NS5-Flag pull-down complex through interaction with NS5.Functional assays showed that SF3B3 overexpression inhibited ZIKV replication by promoting IFN-stimulated gene(ISG)expression whereas silencing of SF3B3 inhibited expression of ISGs to promote ZIKV replication.GTP cyclohydrolase I(GCH1)is the first and ratelimiting enzyme in tetrahydrobiopterin(BH4)biosynthesis.NS5 upregulates the expression of GCH1 during ZIKV infection.And GCH1 marginally promoted ZIKV replication via the IFN pathway.Additionally,GCH1 expression is related to the regulation of SF3B3.Overexpression of the SF3B3 protein effectively reduced GCH1 protein levels,whereas SF3B3 knockdown increased its levels.These findings indicated that ZIKV NS5 binding protein SF3B3 contributed to the host immune response against ZIKV replication by modulating the expression of GCH1.

1,8-二甲基-3,5,7-三硝基-2-喹诺酮诱导人肺癌A549细胞凋亡

目的:研究1,8-二甲基-3,5,7-三硝基-2-喹诺酮对人肺癌A549细胞的促凋亡作用及其可能的分子机制。方法:四甲基偶氮唑蓝(MTT)比色法测定1,8-二甲基-3,5,7-三硝基-2-喹诺酮对A549细胞增殖的影响;流式细胞术检测细胞凋亡率;蛋白免疫印迹法(Western blot)检测1,8-二甲基-3,5,7-三硝基-2-喹诺酮对A549细胞中活化型半胱天冬酶-3(cleavedCaspase-3),B细胞淋巴瘤-2(Bcl-2),Bcl-2相关X蛋白(Bax),总蛋白激酶B(Akt),磷酸化蛋白激酶B(p-Akt),叉头框蛋白O1(FOXO1),磷酸化叉头框蛋白O1(p-FOXO1),Bcl-2促细胞凋亡蛋白(Bim)表达的干预作用。结果:1,8-二甲基-3,5,7-三硝基-2-喹诺酮(1.25,2.5,5,10,20 mg·L-1)能质量浓度和时间依赖性地抑制A549细胞增殖。作用12,24 h的半数抑制浓度(IC50)分别为2.80,2.05μmol·L-1。流式细胞术结果显示1,8-二甲基-3,5,7-三硝基-2-喹诺酮能显著诱导细胞凋亡,随着药物质量浓度的提高,细胞凋亡率逐渐上升。Western blot检测显示,1,8-二甲基-3,5,7-三硝基-2-喹诺酮上调cleaved-Caspase-3和Bax蛋白的表达,下调Bcl-2蛋白的表达。同时会下调p-Akt和p-FOXO1的表达,上调Bim的表达。结论:1,8-二甲基-3,5,7-三硝基-2-喹诺酮能够诱导A549细胞凋亡,该药理作用可能与1,8-二甲基-3,5,7-三硝基-2-喹诺酮抑制磷脂酰肌醇3-激酶(PI3K)/Akt/FOXO1信号通路有关。

Single-nucleotide polymorphism screening and RNA sequencing of key messenger RNAs associated with neonatal hypoxic-ischemia brain damage

A single-nucleotide polymorphism(SNP)is an alteration in one nucleotide in a certain position within a genome.SNPs are associated with disease susceptibility.However,the influences of SNPs on the pathogenesis of neonatal hypoxic-ischemic brain damage remain elusive.Seven-day-old rats were used to establish a hypoxic ischemic encephalopathy model.SNPs and expression profiles of mRNAs were analyzed in hypoxic ischemic encephalopathy model rats using RNA sequencing.Genes exhibiting SNPs associated with hypoxic ischemic encephalopathy were identified and studied by gene ontology and pathway analysis to identify their possible involvement in the disease mechanism.We identified 89 up-regulated genes containing SNPs that were mainly located on chromosome 1 and 2.Gene ontology analysis indicated that the up-regulated genes containing SNPs are mainly involved in angiogenesis,wound healing and glutamatergic synapse and biological processing of calcium-activated chloride channels.Signaling pathway analysis indicated that the differentially expressed genes play a role in glutamatergic synapses,long-term depression and oxytocin signaling.Moreover,intersection analysis of high throughput screening following PubMed retrieval and RNA sequencing for SNPs showed that CSRNP1,DUSP5 and LRRC25 were most relevant to hypoxic ischemic encephalopathy.Significant up-regulation of genes was confirmed by quantitative real-time polymerase chain reaction analysis of oxygen-glucose-deprived human fetal cortical neurons.Our results indicate that CSRNP1,DUSP5 and LRRC25,containing SNPs,may be involved in the pathogenesis of hypoxic ischemic encephalopathy.These findings indicate a novel direction for further hypoxic ischemic encephalopathy research.This animal study was approved on February 5,2017 by the Animal Care and Use Committee of Kunming Medical University,Yunnan Province,China(approval No.kmmu2019038).Cerebral tissue collection from a human fetus was approved on September 30,2015 by the Ethics Committee of Kunming Medical University,China(approval No.2015-9).

Ufl1 deficiency causes kidney atrophy associated with disruption of endoplasmic reticulum homeostasis

The UFMylation modification is a novel ubiquitin-like conjugation system,consisting of UBA5(E1),UFC1(E2),UFL1(E3),and the conjugating molecule UFM1.Deficiency in this modification leads to embryonic lethality in mice and diseases in humans.However,the function of UFL1 is poorly characterized.Studies on Ufl1 conditional knockout mice have demonstrated that the deletion of Ufl1 in cardiomyocytes and in intestinal epithelial cells causes heart failure and increases susceptibility to experimentally induced colitis,respectively,suggesting an essential role of UFL1 in the maintenance of the homeostasis in these organs.Yet,its physiological function in other tissues and organs remains completely unknown.In this study,we generate the nephron tubules specific Ufl1 knockout mice and find that the absence of Ufl1 in renal tubular results in kidney atrophy and interstitial fibrosis.In addition,Ufl1 deficiency causes the activation of unfolded protein response and cell apoptosis,which may be responsible for the kidney atrophy and interstitial fibrosis.Collectively,our results have demonstrated the crucial role of UFL1 in regulating kidney function and maintenance of endoplasmic reticulum homeostasis,providing another layer of understanding kidney atrophy.

Origin and Evolution of Core Components Responsible for Monitoring Light Environment Changes during Plant Terrestrialization

Light serves as the source of energy as well as an information signal for photosynthetic plants. During evolution, plants have acquired the ability to monitor environmental light radiation and adjust their developmental patterns to optimally utilize light energy for photosynthesis. The mechanisms of light perception and signal transduction have been comprehensively studied in past decades, mostly in a few model plants, including Arabidopsis thaliana. However, systematic analyses of the origin and evolution of core components involved in light perception and signaling are still lacking. In this study, we took advantage of the recently sequenced genomes and transcriptomes covering all the main Archaeplastida clades in the public domain to identify orthologous genes of core components involved in light perception and signaling and to reconstruct their evolutionary history. Our analyses suggested that acclimation to different distribution of light quality in new environments led to the origination of specific light signaling pathways in plants. The UVR8 (UV Resistance Locus 8) signaling pathway originated during the movement of plants from the deeper sea to shallow water and enabled plants to deal with ultraviolet B light (UV-B). After acquisition of UV-B adaptation, origination of the phytochrome signaling pathway helped plants to colonize water surface where red light became the prominent light energy source. The seedling emergence pathway, which is mediated by a combination of light and phytohormone signals that orchestrate plant growth pattern transitions, originated before the emergence of seed plants. Although cryptochromes and some key components of E3 ubiquitin ligase systems already existed before the divergence of the plant and animal kingdoms, the coevolution and optimization of light perception and downstream signal transduction components, including key transcription factors and E3 ubiquitin ligase systems, are evident during plant terrestrialization.