Nanobodies against the myelin enzyme CNPase as tools for structural and functional studies.

2',3'-Cyclic nucleotide 3'-phosphodiesterase (CNPase) is an abundant constituent of central nervous system non-compact myelin, and its loss in mice and humans causes neurodegeneration. Additionally, CNPase is frequently used as a marker antigen for myelinating cells. The catalytic activity of CNPase, the 3'-hydrolysis of 2',3'-cyclic nucleotides, is well characterised in vitro, but the in vivo function of CNPase remains unclear.

Nanobodies against the myelin enzyme CNPase as tools for structural and functional studies.

2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) is an abundant constituent of central nervous system non-compact myelin, frequently used as a marker antigen for myelinating cells. The catalytic activity of CNPase, the 3'-hydrolysis of 2',3'-cyclic nucleotides, is well characterised , but the function of CNPase remains unclear. CNPase interacts with the actin cytoskeleton to counteract the developmental closure of cytoplasmic channels that travel through compact myelin; its enzymatic activity may be involved in adenosine metabolism and RNA degradation.

In Vivo and In Vitro Evidence for an Interplay between the Glucocorticoid Receptor and the Vitamin D Receptor Signaling.

Our previous work demonstrated that vitamin D (VitD) reduces experimental autoimmune encephalomyelitis (EAE) disease severity in wild-type (WT) but not in T cell-specific glucocorticoid (GC) receptor (GR)-deficient (GR) mice. This study aimed to investigate the interplay between the GR- and VitD receptor (VDR) signaling. In vivo, we confirmed the involvement of the GR in the VitD-induced effects in EAE using WT and GR mice.

Dual NADPH oxidases DUOX1 and DUOX2 synthesize NAADP and are necessary for Ca signaling during T cell activation.

The formation of Ca microdomains during T cell activation is initiated by the production of nicotinic acid adenine dinucleotide phosphate (NAADP) from its reduced form NAADPH. The reverse reaction—NAADP to NAADPH—is catalyzed by glucose 6-phosphate dehydrogenase (G6PD). Here, we identified NADPH oxidases NOX and DUOX as NAADP-forming enzymes that convert NAADPH to NAADP under physiological conditions in vitro.

Publisher Correction: β-Synuclein-reactive T cells induce autoimmune CNS grey matter degeneration.

In this Article, owing to an error during the production process, the y-axis label of Fig. 2c should read "Number of T cells" rather than "Number of T1 cells" and the left and right panels of Fig. 4 should be labelled 'a' and 'b', respectively.

β-Synuclein-reactive T cells induce autoimmune CNS grey matter degeneration.

The grey matter is a central target of pathological processes in neurodegenerative disorders such as Parkinson's and Alzheimer's diseases. The grey matter is often also affected in multiple sclerosis, an autoimmune disease of the central nervous system. The mechanisms that underlie grey matter inflammation and degeneration in multiple sclerosis are not well understood.

ORAI1, STIM1/2, and RYR1 shape subsecond Ca microdomains upon T cell activation.

The earliest intracellular signals that occur after T cell activation are local, subsecond Ca microdomains. Here, we identified a Ca entry component involved in Ca microdomain formation in both unstimulated and stimulated T cells. In unstimulated T cells, spontaneously generated small Ca microdomains required ORAI1, STIM1, and STIM2.

Laquinimod enhances central nervous system barrier functions.

Laquinimod is currently being tested as a therapeutic drug in multiple sclerosis. However, its exact mechanism of action is still under investigation. Tracking of fluorescently-tagged encephalitogenic T cells during experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, revealed that laquinimod significantly reduces the invasion of pathogenic effector T cells into the CNS tissue.

Intravital real-time analysis of T-cell activation in health and disease.

Antigenic activation is a central process in T-cell biology essential for efficient protection of the host from infections and tumors by the adaptive immune system. Furthermore, this process is of paramount importance for the initiation of autoimmunity. Many insights into the mechanisms of T-cell activation have been gained from real-time studies.

Deletion of 14-3-3σ sensitizes mice to DMBA/TPA-induced papillomatosis.

The p53-inducible cell cycle regulator 14-3-3σ exhibits tumor suppressive functions and is highly expressed in differentiating layers of the epidermis and hair follicles. 14-3-3σ/SFN/stratifin is frequently silenced in human epithelial cancers, and experimental down-regulation of 14-3-3σ expression immortalizes primary human keratinocytes. In the repeated-epilation (ER) mouse model, a heterozygous nonsense mutation of 14-3-3σ causes repeated hair-loss, hyper-proliferative epidermis, and spontaneous development of papillomas and squamous cell carcinomas in aging mice.

Effector T-cell trafficking between the leptomeninges and the cerebrospinal fluid.

In multiple sclerosis, brain-reactive T cells invade the central nervous system (CNS) and induce a self-destructive inflammatory process. T-cell infiltrates are not only found within the parenchyma and the meninges, but also in the cerebrospinal fluid (CSF) that bathes the entire CNS tissue. How the T cells reach the CSF, their functionality, and whether they traffic between the CSF and other CNS compartments remains hypothetical.

IL-6R/STAT3/miR-34a feedback loop promotes EMT-mediated colorectal cancer invasion and metastasis.

Members of the miR-34 family are induced by the tumor suppressor p53 and are known to inhibit epithelial-to-mesenchymal transition (EMT) and therefore presumably suppress the early phases of metastasis. Here, we determined that exposure of human colorectal cancer (CRC) cells to the cytokine IL-6 activates the oncogenic STAT3 transcription factor, which directly represses the MIR34A gene via a conserved STAT3-binding site in the first intron. Repression of MIR34A was required for IL-6-induced EMT and invasion.

A combination of fluorescent NFAT and H2B sensors uncovers dynamics of T cell activation in real time during CNS autoimmunity.

Multiple sclerosis is an autoimmune disease of the central nervous system (CNS) that is initiated when self-reactive T cells enter the brain and become locally activated after encountering their specific nervous antigens. When and where the disease-relevant antigen encounters occur is unclear. Here we combined fluorescently labeled nuclear factor of activated T cells (NFAT) with histone protein H2B to create a broadly applicable molecular sensor for intravital imaging of T cell activation.

T cells become licensed in the lung to enter the central nervous system.

The blood–brain barrier (BBB) and the environment of the central nervous system (CNS) guard the nervous tissue from peripheral immune cells. In the autoimmune disease multiple sclerosis, myelin-reactive T-cell blasts are thought to transgress the BBB and create a pro-inflammatory environment in the CNS, thereby making possible a second autoimmune attack that starts from the leptomeningeal vessels and progresses into the parenchyma. Using a Lewis rat model of experimental autoimmune encephalomyelitis, we show here that contrary to the expectations of this concept, T-cell blasts do not efficiently enter the CNS and are not required to prepare the BBB for immune-cell recruitment.

Inactivation of miR-34a by aberrant CpG methylation in multiple types of cancer.

Recently, we and others identified the microRNA miR-34a as a target of the tumor suppressor gene product p53. Ectopic miR-34a induces a G(1) cell cycle arrest, senescence and apoptosis. Here we report that miR-34a expression is silenced in several types of cancer due to aberrant CpG methylation of its promoter.

Differential regulation of microRNAs by p53 revealed by massively parallel sequencing: miR-34a is a p53 target that induces apoptosis and G1-arrest.

In a genome-wide screen for microRNAs regulated by the transcription factor encoded by the p53 tumor suppressor gene we found that after p53-activation the abundance of thirty-four miRNAs was significantly increased, whereas sixteen miRNAs were suppressed. The induction of miR-34a was most pronounced among all differential regulations. Also expression of the primary miR-34a transcript was induced after p53 activation and by DNA damage in a p53-dependent manner.

c-MYC delays prometaphase by direct transactivation of MAD2 and BubR1: identification of mechanisms underlying c-MYC-induced DNA damage and chromosomal instability.

Here we show that the human BubR1 and MAD2 genes, which encode inhibitors of the anaphase promoting complex (APC/C), are directly activated by the oncogenic transcription factor c-MYC via E-box sequences in their first introns. In colorectal cancer biopsies elevated expression of c-MYC correlated with increased MAD2 levels. Activation of a conditional c-MYC allele delayed progression through mitosis in pro-metaphase in a MAD2- and BubR1-dependent manner.

Epigenetic silencing of 14-3-3sigma in cancer.

The 14-3-3sigma gene is a direct target of the p53 tumor suppressor and its product inhibits cell cycle progression. Recently, a proteomic analysis revealed that 14-3-3sigma regulates additional cellular processes relevant to carcinogenesis, as migration and MAP-kinase signalling. The expression of 14-3-3sigma is down-regulated by CpG methylation in several types of human cancer, among them prostate, lung, breast and several types of skin cancer.

The role of epigenetic inactivation of 14-3-3sigma in human cancer.

Cancer cells show characteristic alterations in DNA methylation patterns. Aberrant CpG methylation of specific promoters results in inactivation of tumor suppressor genes and therefore plays an important role in carcinogenesis. The p53-regulated gene 14-3-3sigma undergoes frequent epigenetic silencing in several types of cancer, including carcinoma of the breast, prostate, and skin, suggesting that the loss of 14-3-3sigma expression may be causally involved in tumor progression.