Age-Associated Failure To Adjust Type I IFN Receptor Signaling Thresholds after T Cell Activation.

With increasing age, naive CD4 T cells acquire intrinsic defects that compromise their ability to respond and differentiate. Type I IFNs, pervasive constituents of the environment in which adaptive immune responses occur, are known to regulate T cell differentiation and survival. Activated naive CD4 T cells from older individuals have reduced responses to type I IFN, a defect that develops during activation and that is not observed in quiescent naive CD4 T cells. Naive CD4 T cells from young adults upregulate the expression of STAT1 and STAT5 after activation, lowering their threshold to respond to type I IFN stimulation. The heightened STAT signaling is critical to maintain the expression of CD69 that regulates lymphocyte egress and the ability to produce IL-2 and to survive. Although activation of T cells from older adults also induces transcription of STAT1 and STAT5, failure to exclude SHP-1 from the signaling complex blunts their type I IFN response. In summary, our data show that type I IFN signaling thresholds in naive CD4 T cells after activation are dynamically regulated to respond to environmental cues for clonal expansion and memory cell differentiation. Naive CD4 T cells from older adults have a defect in this threshold calibration. Restoring their ability to respond to type I IFN emerges as a promising target to restore T cell responses and to improve the induction of T cell memory.

Exogenous nitric oxide induces disease resistance against Monilinia fructicola through activating the phenylpropanoid pathway in peach fruit.

BACKGROUND: Nitric oxide (NO) is a multifunctional signaling molecule involved in plant-induced resistance to disease. The present study aimed to investigate the relationship between disease resistance induced by NO and the phenylpropanoid pathway in peach fruit. The present study investigated the effect of NO on the main enzymes and metabolites of the phenylpropanoid pathway of harvested peach, which are probably related to disease resistance against Monilinia fructicola. RESULTS: The results showed that treatment with 15 µmol L-1 NO significantly (P < 0.05) enhanced the activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, 4-coumaroyl-CoA ligase, chalcone synthase and chalcone isomerase and the expression of their genes. Furthermore, NO treatment significantly (P < 0.05) increased the contents of total phenolics, flavonoids and lignin over the entire storage period and maintained higher total anthocyanin, phenolic acid and anthocyanin contents during the earlier storage period. CONCLUSION: These results suggest that NO treatment could activate the phenylpropanoid pathway to enhance the activity of related enzymes and the contents of phenylpropanoid metabolites in peach to improve disease resistance and prevent pathogenic invasion. © 2016 Society of Chemical Industry.

Signaling pathways in aged T cells - a reflection of T cell differentiation, cell senescence and host environment.

With increasing age, the ability of the immune system to protect against new antigenic challenges or to control chronic infections erodes. Decline in thymic function and cumulating antigenic experiences of acute and chronic infections threaten T cell homeostasis, but insufficiently explain the failing immune competence and the increased susceptibility for autoimmunity. Alterations in signaling pathways in the aging T cells account for many of the age-related defects. Signaling threshold calibrations seen with aging frequently built on mechanisms that are operational in T cell development and T cell differentiation or are adaptations to the changing environment in the aging host. Age-related changes in transcription of receptors and signaling molecules shift the balance towards inhibitory pathways, most dominantly seen in CD8 T cells and to a lesser degree in CD4 T cells. Prominent examples are the expression of negative regulatory receptors of the CD28 and the TNF receptor superfamilies as well the expression of various cytoplasmic and nuclear dual-specific phosphatases.

Signal inhibition by the dual-specific phosphatase 4 impairs T cell-dependent B-cell responses with age.

T cell-dependent B-cell responses decline with age, suggesting defective CD4 T-cell function. CD4 memory T cells from individuals older than 65 y displayed increased and sustained transcription of the dual-specific phosphatase 4 (DUSP4) that shortened expression of CD40-ligand (CD40L) and inducible T-cell costimulator (ICOS) (both P < 0.001) and decreased production of IL-4, IL-17A, and IL-21 (all P < 0.001) after in vitro activation. In vivo after influenza vaccination, activated CD4 T cells from elderly individuals had increased DUSP4 transcription (P = 0.002), which inversely correlated with the expression of CD40L (r = 0.65, P = 0.002), ICOS (r = 0.57, P = 0.008), and IL-4 (r = 0.66, P = 0.001). In CD4 KO mice reconstituted with DUSP4 OT-II T cells, DUSP4 had a negative effect on the expansion of antigen-specific B cells (P = 0.003) and the production of ova-specific antibodies (P = 0.03) after immunization. Silencing of DUSP4 in memory CD4 T cells improved CD40L (P < 0.001), IL-4 (P = 0.007), and IL-21 (P = 0.04) expression significantly more in the elderly than young adults. Consequently, the ability of CD4 memory T cells to support B-cell differentiation that was impaired in the elderly (P = 0.004) was restored. Our data suggest that increased DUSP4 expression in activated T cells in the elderly in part accounts for defective adaptive immune responses.

K-RAS GTPase- and B-RAF kinase-mediated T-cell tolerance defects in rheumatoid arthritis.

Autoantibodies to common autoantigens and neoantigens, such as IgG Fc and citrullinated peptides, are immunological hallmarks of rheumatoid arthritis (RA). We examined whether a failure in maintaining tolerance is mediated by defects in T-cell receptor activation threshold settings. RA T cells responded to stimulation with significantly higher ERK phosphorylation (P < 0.001). Gene expression arrays of ERK pathway members suggested a higher expression of KRAS and BRAF, which was confirmed by quantitative PCR (P = 0.003), Western blot, and flow cytometry (P < 0.01). Partial silencing of KRAS and BRAF lowered activation-induced phosphorylated ERK levels (P < 0.01). In individual cells, levels of these signaling molecules correlated with ERK phosphorylation, attesting that their concentrations are functionally important. In confocal studies, B-RAF/K-RAS clustering was increased in RA T cells 2 min after T-cell receptor stimulation (P < 0.001). Overexpression of B-RAF and K-RAS in normal CD4 T cells amplified polyclonal T-cell proliferation and facilitated responses to citrullinated peptides. We propose that increased expression of B-RAF and K-RAS lowers T-cell activation thresholds in RA T cells, enabling responses to autoantigens.

Clinical study on simultaneous resection of liver metastases combined with hyperthermic intraperitoneal chemotherapy for synchronous colorectal cancer liver metastasis.

PURPOSE: This study aimed to analyze the clinical effect of simultaneous resection of liver metastases combined with hyperthermic intraperitoneal chemotherapy (HIPEC) on synchronous colorectal cancer liver metastasis. METHODS: A total of 144 patients with synchronous colorectal cancer liver metastasis who were admitted to our hospital between January 2018 and January 2019 were randomly assigned into a control group and an intervention group. The patients in the control group received simultaneous resection of liver metastases. The patients in the intervention group obtained simultaneous resection of liver metastases combined with HIPEC. The recent total effective rate of the 2 groups was compared, and the disease control rate of the 2 groups was calculated at 3 months after treatment. The patients were followed up for 3 years. The survival time of the 2 groups was observed and compared. Fasting venous blood was collected from patients in the 2 groups, and the carcinoembryonic antigen (CEA) level was compared. The level of quality of life scale (Short Form 36-item Health Survey) and the occurrence of adverse reactions were compared between the 2 groups. RESULTS: The R0 complete resection rate in the intervention group was significantly higher than that in the control group (P < .05). The recent total effective rate in the intervention group (87.50%) was significantly higher than that in the control group (59.72%) (P < .05). The negative change of CEA in the intervention group was 72.22%, which was prominently higher than that in the control group of 43.06% (χ2 = 12.542, P < .001). After a 36-month follow-up, the overall survival rate of the observation group was significantly higher than that of the control group (hazard ratio, 2.54; 95% CI, 1.05-5.48; P < .001). The patients in the intervention group had significantly higher life quality scores of health status, social function, emotional function, physical function, and mental health than in the control group (P < .05). There was no significant difference in the incidence of complications between the 2 groups (P > .05). Age > 60 years, preoperative comorbidities, moderate and high differentiation of tumors, intraoperative blood loss > 150 mL, and less experienced surgeons were risk factors affecting the occurrence of complications after treatment and were closely correlated with the prognosis and survival of patients (P < .05). Patients with age ≤ 60 years, no preoperative comorbidities, low tumor differentiation, intraoperative blood loss ≤ 150 mL, more experienced surgeons, and complete R0 resection had a longer survival time. Age > 60 years, preoperative comorbidities, moderate and high differentiation of tumors, intraoperative blood loss > 150 mL, and less experienced surgeons were independent risk factors affecting the prognosis of patients with colorectal cancer liver metastases (P < .05), whereas R0 surgery was an independent protective factor for the prognosis (P < .05). CONCLUSION: In the treatment of synchronous colorectal cancer liver metastases, simultaneous resection of liver metastases in conjunction with HIPEC demonstrated superior efficacy. This approach may potentially extend patient survival and enhance quality of life and deserve to be extensively used in clinical practice.

Tonian carbonaceous compressions indicate that Horodyskia is one of the oldest multicellular and coenocytic macro-organisms.

Macrofossils with unambiguous biogenic origin and predating the one-billion-year-old multicellular fossils Bangiomorpha and Proterocladus interpreted as crown-group eukaryotes are quite rare. Horodyskia is one of these few macrofossils, and it extends from the early Mesoproterozoic Era to the terminal Ediacaran Period. The biological interpretation of this enigmatic fossil, however, has been a matter of controversy since its discovery in 1982, largely because there was no evidence for the preservation of organic walls. Here we report new carbonaceous compressions of Horodyskia from the Tonian successions (~950-720 Ma) in North China. The macrofossils herein with bona fide organic walls reinforce the biogenicity of Horodyskia. Aided by the new material, we reconstruct Horodyskia as a colonial organism composed of a chain of organic-walled vesicles that likely represent multinucleated (coenocytic) cells of early eukaryotes. Two species of Horodyskia are differentiated on the basis of vesicle sizes, and their co-existence in the Tonian assemblage provides a link between the Mesoproterozoic (H. moniliformis) and the Ediacaran (H. minor) species. Our study thus provides evidence that eukaryotes have acquired macroscopic size through the combination of coenocytism and colonial multicellularity at least ~1.48 Ga, and highlights an exceptionally long range and morphological stasis of this Proterozoic macrofossils.

Potential molecular mechanisms of Erlongjiaonang action in idiopathic sudden hearing loss: A network pharmacology and molecular docking analyses.

Background: Idiopathic sudden hearing loss (ISHL) is characterized by sudden unexplainable and unilateral hearing loss as a clinically emergent symptom. The use of the herb Erlongjiaonang (ELJN) in traditional Chinese medicine is known to effectively control and cure ISHL. This study explored the underlying molecular mechanisms using network pharmacology and molecular docking analyses. Method: The Traditional Chinese Medicine System Pharmacological database and the Swiss Target Prediction database were searched for the identification of ELJN constituents and potential gene targets, respectively, while ISHL-related gene abnormality was assessed using the Online Mendelian Inheritance in Man and Gene Card databases. The interaction of ELJN gene targets with ISHL genes was obtained after these databases were cross-screened, and a drug component-intersecting target network was constructed, and the gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes, and protein-protein interaction networks were analyzed. Cytoscape software tools were used to map the active components-crossover target-signaling pathway network and screened targets were then validated by establishing molecular docking with the corresponding components. Result: Erlongjiaonang contains 85 components and 250 corresponding gene targets, while ISHL has 714 disease-related targets, resulting in 66 cross-targets. The bioinformatical analyses revealed these 66 cross-targets, including isorhamnetin and formononetin on NOS3 expression, baicalein on AKT1 activity, and kaempferol and quercetin on NOS3 and AKT1 activity, as potential ELJN-induced anti-ISHL targets. Conclusion: This study uncovered potential ELJN gene targets and molecular signaling pathways in the control of ISHL, providing a molecular basis for further investigation of the anti-ISHL activity of ELJN.

Protein sulfenylation contributes to oxidative burst-triggered responses during the interaction between Botrytis cinerea and Nicotiana benthamiana.

Reactive oxygen species (ROS) play a crucial role as signaling molecules in plant responses to pathogen infection. It is highly reactive with cellular components such as DNA, lipids and proteins, thereby leading to serious oxidative damages. Cysteine residues are sensitive targets of ROS in a post-translational modification known as sulfenylation. However, during plant-pathogen interaction, it is still unclear which specific proteins can be oxidized by ROS and undergo sulfenic modification to regulate the interaction process. Here, we observed a biphasic production of ROS in Nicotiana benthamiana after inoculation with Botrytis cinerea. RT-qPCR results showed that the biphasic increase in ROS production was closely related to the expression of NbRbohA, NbRbohB and NbRbohC. Furthermore, a ROS-dependent sulfenome analysis was performed and finally 183 differentially sulfenylated proteins were identified. Their post-translational sulfenylation modification in response to B. cinerea infection was further confirmed by western blot and mass spectrometry analysis. Virus-induced gene silencing of those genes encoding sulfenylated proteins resulted in reduced resistance to B. cinerea. Taken together, our data demonstrate that B. cinerea infection induces ROS burst in N. benthamiana, which triggers protein sulfenylation to ensure the transduction of ROS signals and further function in plant-pathogen interaction. SIGNIFICANCE: Reactive oxygen species (ROS) induced by Botrytis cinerea infection trigger changes in cellular redox status through protein sulfenylation to be involved in plant-pathogen interaction.

Rosai-Dorfman disease originating from nasal septal mucosa and presenting with nasal dorsum collapse: A case report with literature review.

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, is an uncommon histiocytic disease with idiopathic etiology and unique pathology. Extra-nodal RDD that occurs in the nasal cavity is extremely unusual and the characteristic clinical features are unknown. Herein, we report a case of nasal septum RDD, with intermittent epistaxis from the left nasal cavity, which led to collapse of the nasal bridge. The patient underwent surgical biopsy, and a diagnosis of nasal septum RDD was established. No further treatment was performed. An enlarged mass was found in the second postoperative year which was treated by surgical excision in the third postoperative year. To improve the current diagnostic and therapeutic approach of extra-nodal RDD, we incorporate previous reports from the literature to discuss the pathological characteristics, pathogenesis, clinical manifestations, diagnosis, and therapy for this rare disease.

Application and prospect of quasi-targeted metabolomics in age-related hearing loss.

Age-related hearing loss (ARHL) is a common sensory deficit in the elderly, which seriously affects physical and mental health. Therefore, understanding its underlying molecular mechanisms and taking interventions to treat ARHL are urgently needed. In our study, cochlea of 4-week-old C57BL/6 mice as the Youth group (n = 6) and 48-week-old cochlea as the Old group (n = 6) were subjected to quasi-targeted metabolomics analysis by Ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In total, 208 differential metabolites were identified in 12 cochlea samples, which highlighted the following discriminant compounds: tryptophan, piperidine, methionine, L-arginine, histamine, serotonin, acetylcholine, and 4-aminobutyric acid. Differentially expressed metabolites were identified which were involved in KEGG pathways related to the digestion and absorption of oxidative stress associated amino acids, Synaptic vesicle cycle of serotonin, Pantothenate and CoA Biosynthesis. These findings are a first step toward elucidating the pathophysiological pathways involved in the etiology of ARHL and provide the possibility to further explore the mechanisms of ARHL using metabolomic analysis.

Epigenetic regulation of killer immunoglobulin-like receptor expression in T cells.

With increasing age, T cells gain expression of killer immunoglobulin-like receptors (KIRs) that transmit negative signals and dampen the immune response. KIR expression is induced in CD4 and CD8 T cells by CpG DNA demethylation suggesting epigenetic control. To define the mechanisms that underlie the age-associated preferential KIR expression in CD8 T cells, we examined KIR2DL3 promoter methylation patterns. With age, CD8 T cells developed a patchy and stochastic promoter demethylation even in cells that did not express the KIR2DL3-encoded CD158b protein; complete demethylation of the minimal KIR2DL3 promoter was characteristic for CD158b-expressing cells. In contrast, the promoter in CD4 T cells was fully methylated irrespective of age. The selectivity for CD8 T cells correlated with lower DNMT1 recruitment to the KIR2DL3 promoter which further diminished with age. In contrast, binding of the polycomb protein EZH2 known to be involved in DNMT1 recruitment was not different. Our data suggest that CD8 T cells endure increasing displacement of DNMT1 from the KIR promoter with age, possibly because of an active histone signature. The ensuing partial demethylation lowers the threshold for transcriptional activation and renders CD8 T cells more susceptible to express KIR, thereby contributing to the immune defect in the elderly.

Roles of Aquaporins in Plant-Pathogen Interaction.

Aquaporins (AQPs) are a class of small, membrane channel proteins present in a wide range of organisms. In addition to water, AQPs can facilitate the efficient and selective flux of various small solutes involved in numerous essential processes across membranes. A growing body of evidence now shows that AQPs are important regulators of plant-pathogen interaction, which ultimately lead to either plant immunity or pathogen pathogenicity. In plants, AQPs can mediate H2O2 transport across plasma membranes (PMs) and contribute to the activation of plant defenses by inducing pathogen-associated molecular pattern (PAMP)-triggered immunity and systemic acquired resistance (SAR), followed by downstream defense reactions. This involves the activation of conserved mitogen-activated protein kinase (MAPK) signaling cascades, the production of callose, the activation of NPR1 and PR genes, as well as the opening and closing of stomata. On the other hand, pathogens utilize aquaporins to mediate reactive oxygen species (ROS) signaling and regulate their normal growth, development, secondary or specialized metabolite production and pathogenicity. This review focuses on the roles of AQPs in plant immunity, pathogenicity, and communications during plant-pathogen interaction.

Cyanine-based fluorescent indicator for mercury ion and bioimaging application in living cells.

A commercial cyanine dye IR-780 and a thioether-containing dicarboxylic acid ligand were used to construct the near-infrared fluorescent probe, which was used as a near-infrared fluorescent indicator for the determination of mercury ions in water and in living cells. This indicator displayed high specificity towards Hg2+ without any interference from other detecting species. Especially, the emission at 790 nm dramatically increased more than 25 times after interacting with Hg2+. The binding experiment showed that the indicator formed 1:1 complex with Hg2+. More, this indicator could be applied in the visualization of Hg2+ in living cells and measuring the Hg2+ concentration of tap-water sample.

Epigenetic mechanisms of age-dependent KIR2DL4 expression in T cells.

Killer Ig-like receptor (KIR) expression is mostly restricted to NK cells controlling their activation. With increasing age, KIRs are expressed on T cells and contribute to age-related diseases. We examined epigenetic mechanisms that determine the competency of T cells to transcribe KIR2DL4. Compared with Jurkat cells and CD4(+)CD28(+) T cells from young individuals, DNA methyltransferase (DNMT) inhibition was strikingly more effective in T cells from elderly adults and the CD4(+)CD28(-) T cell line HUT78 to induce KIR2DL4 transcription. In these susceptible cells, the KIR2DL4 promoter was partially demethylated, and dimethylated H3-Lys 4 was increased, and all other histone modifications were characteristic for an inactive promoter. In comparison, NK cells had a fully demethylated KIR2DL4 promoter and the full spectrum of histone modifications indicative of active transcription with H3 and H4 acetylation, di- and trimethylated H3-Lys 4, and reduced, dimethylated H3-Lys 9. These results suggest that an increased competency of T cells to express KIR2DL4 with aging is conferred by a selective increase in H3-Lys 4 dimethylation and limited DNA demethylation. The partially accessible promoter is sensitive to DNMT inhibition, which is sufficient to induce full transcription without further histone acetylation and methylation.

Transcription factor networks in aged naïve CD4 T cells bias lineage differentiation.

With reduced thymic activity, the population of naïve T cells in humans is maintained by homeostatic proliferation throughout adult life. In young adults, naïve CD4 T cells have enormous proliferative potential and plasticity to differentiate into different lineages. Here, we explored whether naïve CD4 T-cell aging is associated with a partial loss of this unbiased multipotency. We find that naïve CD4 T cells from older individuals have developed a propensity to develop into TH9 cells. Two major mechanisms contribute to this predisposition. First, responsiveness to transforming growth factor ß (TGFß) stimulation is enhanced with age due to an upregulation of the TGFßR3 receptor that results in increased expression of the transcription factor PU.1. Secondly, aged naïve CD4 T cells display altered transcription factor profiles in response to T-cell receptor stimulation, including enhanced expression of BATF and IRF4 and reduced expression of ID3 and BCL6. These transcription factors are involved in TH9 differentiation as well as IL9 transcription suggesting that the aging-associated changes in the transcription factor profile favor TH9 commitment.

Regulation of miR-181a expression in T cell aging.

MicroRNAs have emerged as key regulators in T cell development, activation, and differentiation, with miR-181a having a prominent function. By targeting several signaling pathways, miR-181a is an important rheostat controlling T cell receptor (TCR) activation thresholds in thymic selection as well as peripheral T cell responses. A decline in miR-181a expression, due to reduced transcription of pri-miR-181a, accounts for T cell activation defects that occur with older age. Here we examine the transcriptional regulation of miR-181a expression and find a putative pri-miR-181a enhancer around position 198,904,300 on chromosome 1, which is regulated by a transcription factor complex including YY1. The decline in miR-181a expression correlates with reduced transcription of YY1 in older individuals. Partial silencing of YY1 in T cells from young individuals reproduces the signaling defects seen in older T cells. In conclusion, YY1 controls TCR signaling by upregulating miR-181a and dampening negative feedback loops mediated by miR-181a targets.

Interaction of nuclear receptor zinc finger DNA binding domains with histone deacetylase.

A direct interaction between the nuclear receptor TR2 and histone deacetylases (HDACs) 3 and 4 is mediated by the DNA binding domain (DBD) of TR2. To test if this interaction is common to members of the nuclear receptor family, the Cys2-Cys2 type zinc finger (ZF) DBDs were subcloned from several nuclear receptors (mRARalpha, mRXRbeta, mTR2, mTR4, RAR, mPPARdelta, and mPPARgamma2). Using GST pull-downs, both HDACs 3 and 4 were found to interact directly with the core DBD from each receptor. The three-dimensional structure of the ZF domains was essential for this interaction as disruption by zinc chelation precluded interaction with HDACs. The results suggest that the ZFs of nuclear receptors provide a general interaction interface for HDACs 3 and 4. Functional significance of this interaction was demonstrated using ChIP assays where a truncated TR2 protein (lacking the LBD) recruited HDACs 3 and 4 to the target DNA causing demonstrable histone deacetylation. GST pull-downs and mammalian two-hybrid interaction tests were then used to define the interaction domains of HDAC3 with TR2. Both the N- and C-terminal portions of HDAC3 showed interaction with the TR2 DBD. Thus, multiple domains of HDAC3 form the interaction surface for the DBD of nuclear receptors.

The janus head of T cell aging - autoimmunity and immunodeficiency.

Immune aging is best known for its immune defects that increase susceptibility to infections and reduce adaptive immune responses to vaccination. In parallel, the aged immune system is prone to autoimmune responses and many autoimmune diseases increase in incidence with age or are even preferentially encountered in the elderly. Why an immune system that suboptimally responds to exogenous antigen fails to maintain tolerance to self-antigens appears to be perplexing. In this review, we will discuss age-associated deviations in the immune repertoire and the regulation of signaling pathways that may shed light on this conundrum.

Decline in miR-181a expression with age impairs T cell receptor sensitivity by increasing DUSP6 activity.

The ability of the human immune system to respond to vaccination declines with age. We identified an age-associated defect in T cell receptor (TCR)-induced extracellular signal-regulated kinase (ERK) phosphorylation in naive CD4(+) T cells, whereas other signals, such as ζ chain-associated protein kinase 70 (ZAP70) and phospholipase C-γ1 phosphorylation, were not impaired. The defective ERK signaling was caused by the dual specific phosphatase 6 (DUSP6), whose protein expression increased with age due to a decline in repression by miR-181a. Reconstitution of miR-181a lowered DUSP6 expression in naive CD4(+) T cells in elderly individuals. DUSP6 repression using miR-181a or specific siRNA and DUSP6 inhibition by the allosteric inhibitor (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one improved CD4(+) T cell responses, as seen by increased expression of activation markers, improved proliferation and supported preferential T helper type 1 cell differentiation. DUSP6 is a potential intervention target for restoring T cell responses in the elderly, which may augment the effectiveness of vaccination.