A placebo-controlled randomised trial of budesonide for PBC following an insufficient response to UDCA

Background & Aims: In patients with primary biliary cholangitis (PBC), the efficacy of budesonide, a synthetic corticosteroid displaying high first-pass metabolism, is unresolved. In a placebo-controlled, double-blind trial, we evaluated the added-value of budesonide in those with PBC and ongoing risk of progressive disease despite ursodeoxycholic acid (UDCA) treatment. Methods: We evaluated 62 patients with PBC who had histologically confirmed hepatic inflammatory activity, according to the Ishak score, and an alkaline phosphatase (ALP) >1.5x upper limit of normal (ULN), after at least 6 months of UDCA therapy. Participants were randomly assigned 2:1 to receive budesonide (9 mg/day) or placebo once daily, for 36 months, with UDCA treatment (12-16 mg/kg body weight/day) maintained. Primary efficacy was defined as improvement of liver histology with respect to inflammation and no progression of fibrosis. Secondary outcomes included changes in biochemical markers of liver injury. Results: Recruitment challenges resulted in a study that was underpowered for the primary efficacy analysis. Comparing patients with paired biopsies only (n = 43), the primary histologic endpoint was not met (p>0.05). The proportion of patients with ALP = 15% decrease in ALP and normal bilirubin was higher in the budesonide group than in the placebo group at 12, 24, and 36 months (p Conclusion: Budesonide add-on therapy was not associated with improved liver histology in patients with PBC and insufficient response to UDCA; however, improvements in biochemical markers of disease activity were demonstrated in secondary analyses. Lay summary: Around one-third of patients with primary biliary cholangitis (PBC) needs additional medical therapy alongside ursodeoxycholic acid (UDCA) treatment. In this clinical trial, the addition of the corticosteroid budesonide did not improve liver histology; there were however relevant improvements in liver blood tests. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V.Peer reviewe

Centrosomal microtubule nucleation regulates radial migration of projection neurons independently of polarization in the developing brain

Cortical projection neurons polarize and form an axon while migrating radially. Even though these dynamic processes are closely interwoven, they are regulated separately-the neurons terminate their migration when reaching their destination, the cortical plate, but continue to grow their axons. Here, we show that in rodents, the centrosome distinguishes these processes. Newly developed molecular tools modulating centrosomal microtubule nucleation combined with in vivo imaging uncovered that dysregulation of centro-somal microtubule nucleation abrogated radial migration without affecting axon formation. Tightly regu-lated centrosomal microtubule nucleation was required for periodic formation of the cytoplasmic dilation at the leading process, which is essential for radial migration. The microtubule nucleating factor g-tubulin decreased at neuronal centrosomes during the migratory phase. As distinct microtubule networks drive neuronal polarization and radial migration, this provides insight into how neuronal migratory defects occur without largely affecting axonal tracts in human developmental cortical dysgeneses, caused by mutations in g-tubulin.ISSN:0896-6273ISSN:1097-419

Disruption of Coronin 1 Signaling in T Cells Promotes Allograft Tolerance while Maintaining Anti-Pathogen Immunity

The ability of the immune system to discriminate self from non-self is essential for eradicating microbial pathogens but is also responsible for allograft rejection. Whether it is possible to selectively suppress alloresponses while maintaining anti-pathogen immunity remains unknown. We found that mice deficient in coronin 1, a regulator of naive T cell homeostasis, fully retained allografts while maintaining T cell-specific responses against microbial pathogens. Mechanistically, coronin 1-deficiency increased cyclic adenosine monophosphate (cAMP) concentrations to suppress allo-specific T cell responses. Costimulation induced on microbe-infected antigen presenting cells was able to overcome cAMP-mediated immunosuppression to maintain anti-pathogen immunity. In vivo pharmacological modulation of this pathway or a prior transfer of coronin 1-deficient T cells actively suppressed allograft rejection. These results define a coronin 1-dependent regulatory axis in T cells important for allograft rejection and suggest that modulation of this pathway may be a promising approach to achieve long-term acceptance of mismatched allografts

Controlled Demolition: Smurf1 Regulates Neuronal Polarity by Substrate Switching

During axon specification, growth promoting proteins localize selectively to the growing axon. In this issue of Neuron, Cheng et al. report how selective protein degradation, controlled by a substrate switch of the ubiquitin ligase Smurf1, specifies Par6 and RhoA localization and thereby regulates neuronal polarity

Role for coronin 1 in mouse NK cell function

Coronin 1, a member of the evolutionary conserved WD repeat protein family of coronin proteins is expressed in all leukocytes, but a role for coronin 1 in natural killer (NK) cell homeostasis and function remains unclear. Here, we have analyzed the number and functionality of NK cells in the presence and absence of coronin 1. In coronin 1-deficient mice, absolute NK cell numbers and phenotype were comparable to wild type mice in blood, spleen and liver. Following in vitro stimulation of the activating NK cell receptors NK1.1, NKp46, Ly49D and NKG2D, coronin 1-deficient NK cells were functional with respect to interferon-γ production, degranulation and intracellular Ca(2+) mobilization. Also, both wild type as well as coronin 1-deficient NK cells showed comparable cytotoxic activity. Furthermore, activation and functionality of NK cells following Vesicular Stomatitis Virus (VSV) infection was similar between wild type and coronin 1-deficient mice. Taken together these data suggest that coronin 1 is dispensable for mouse NK cell homeostasis and function

Coronin 1 is dispensable for leukocyte recruitment and liver injury in concanavalin A-induced hepatitis

Coronin 1, a member of the evolutionary conserved coronin protein family, is highly expressed in all leukocytes. In mice and human, genetic inactivation of coronin 1 results in immuno-deficiencies that are linked to a strong reduction of naïve T cell numbers in peripheral organs, while memory/effector T cells, B cells, monocytes and neutrophils are less or not at all affected. Whether or not coronin 1 is important for leukocyte functions such as migration and phagocytosis has been a matter of debate. The current work addresses coronin 1-dependent leukocyte function by analyzing the response of coronin 1-deficient mice in a model of concanavalin A (Con A)-induced liver injury. Histological evaluation and determination of serum liver enzyme levels showed that coronin 1-deficient mice develop signs of acute hepatitis similar to Con A-treated wild type mice despite a reduced activation of T cells in the absence of coronin 1. Furthermore, analysis by intravital microscopy following Con A stimulation revealed that Gr-1(+) neutrophils and CD4(+) T cell adhesion in the post-sinusoidal venules increased in wild type as well as in coronin 1-deficient mice. These results suggest that coronin 1, while important for naïve T cell survival, is dispensable for other leukocyte function under inflammatory conditions in vivo

Rifamycin SV-MMX® for treatment of travellers' diarrhea: equally effective as ciprofloxacin and not associated with the acquisition of multi-drug resistant bacteria

Background The novel oral antibiotic formulation Rifamycin SV-MMX®, with a targeted delivery to the distal small bowel and colon, was superior to placebo in treating travellers' diarrhea (TD) in a previous study. Thus, a study was designed to compare this poorly absorbed antibiotic with the systemic agent ciprofloxacin. Methods In a randomized double-blind phase 3 study (ERASE), the efficacy and safety of Rifamycin SV-MMX® 400 mg twice daily (RIF-MMX) was compared with ciprofloxacin 500 mg twice daily in the oral treatment of TD. Overall, 835 international visitors to India, Guatemala or Ecuador with acute TD were randomized to receive a 3-day treatment with RIF-MMX (n = 420) or ciprofloxacin (n = 415). Primary endpoint was time to last unformed stool (TLUS), after which clinical cure was declared. Stools samples for microbiological evaluation were collected at the baseline visit and the end of treatment visit. Results Median TLUS in the RIF-MMX group was 42.8 h versus 36.8 h in the ciprofloxacin group indicating non-inferiority of RIF-MMX to ciprofloxacin (P = 0.0035). Secondary efficacy endpoint results including clinical cure rate, treatment failure rate, requirement of rescue therapy as well as microbiological eradication rate confirmed those of the primary analysis indicating equal efficacy for both compounds. While patients receiving ciprofloxacin showed a significant increase of Extended Spectrum Beta Lactamase Producing-Escherichia coli (ESBL-E. Coli) colonization rates after 3-days treatment (6.9%), rates did not increase in patients receiving RIF-MMX (-0.3%). Both drugs were well-tolerated and safe. Conclusion The novel multi-matrix formulation of the broad-spectrum, poorly absorbed antibiotic Rifamycin SV was found non-inferior to the systemic antibiotic ciprofloxacin in the oral treatment of non-dysenteric TD with the advantage of a lower risk of ESBL-E. Coli acquisition

Tumor suppressor down-regulated in renal cell carcinoma 1 (DRR1) is a stress-induced actin bundling factor that modulates synaptic efficacy and cognition

Stress has been identified as a major causal factor for many mental disorders. However, our knowledge about the chain of molecular and cellular events translating stress experience into altered behavior is still rather scant. Here, we have characterized a murine ortholog of the putative tumor suppressor gene DRR1 as a unique stress-induced protein in brain. It binds to actin, promotes bundling and stabilization of actin filaments, and impacts on actin-dependent neurite outgrowth. Endogenous DRR1 localizes to some, but not all, synapses, with preference for the presynaptic region. Hippocampal virus-mediated enhancement of DRR1 expression reduced spine density, diminished the probability of synaptic glutamate release, and altered cognitive performance. DRR1 emerges as a protein to link stress with actin dynamics, which in addition is able to act on synaptic function and cognition

A Dual SILAC Proteomic Labeling Strategy for Quantifying Constitutive and Cell–Cell Induced Protein Secretion

Recent evidence suggests that the extracellular protein milieu is much more complex than previously assumed as various secretome analyses from different cell types described the release of hundreds to thousands of proteins. The extracellular function of many of these proteins has yet to be determined particularly in the context of three-dimensional tissues with abundant cell–cell contacts. Toward this goal, we developed a strategy of dual SILAC labeling astrocytic cultures for in silico exclusion of unlabeled proteins from serum or neurons used for stimulation. For constitutive secretion, this strategy allowed the precise quantification of the extra-to-intracellular protein ratio of more than 2000 identified proteins. Ratios covered 4 orders of magnitude indicating that the intracellular vs extracellular contributions of different proteins can be variable. Functionally, the secretome of labeled forebrain astrocytic cultures specifically changed within hours after adding unlabeled, “physiological” forebrain neurons. “Nonphysiological” cerebellar hindbrain neurons, however, elicited a different, highly repulsive secretory response. Our data also suggest a significant association of constitutive secretion with the classical secretion pathway and regulated secretion with unconventional pathways. We conclude that quantitative proteomics can help to elucidate general principles of cellular secretion and provide functional insight into the abundant extracellular presence of proteins

Single-cell axotomy of cultured hippocampal neurons integrated in neuronal circuits

An understanding of the molecular mechanisms of axon regeneration after injury is key for the development of potential therapies. Single-cell axotomy of dissociated neurons enables the study of the intrinsic regenerative capacities of injured axons. This protocol describes how to perform single-cell axotomy on dissociated hippocampal neurons containing synapses. Furthermore, to axotomize hippocampal neurons integrated in neuronal circuits, we describe how to set up coculture with a few fluorescently labeled neurons. This approach allows axotomy of single cells in a complex neuronal network and the observation of morphological and molecular changes during axon regeneration. Thus, single-cell axotomy of mature neurons is a valuable tool for gaining insights into cell intrinsic axon regeneration and the plasticity of neuronal polarity of mature neurons. Dissociation of the hippocampus and plating of hippocampal neurons takes ∼2 h. Neurons are then left to grow for 2 weeks, during which time they integrate into neuronal circuits. Subsequent axotomy takes 10 min per neuron and further imaging takes 10 min per neuron