A C-terminal motif containing a PKC phosphorylation site regulates γ-Protocadherin-mediated dendrite arborization in the cerebral cortex in vivo.

The Pcdhg gene cluster encodes 22 γ-Protocadherin (γ-Pcdh) cell adhesion molecules that critically regulate multiple aspects of neural development, including neuronal survival, dendritic and axonal arborization, and synapse formation and maturation. Each γ-Pcdh isoform has unique protein domains-a homophilically interacting extracellular domain and a juxtamembrane cytoplasmic domain-as well as a C-terminal cytoplasmic domain shared by all isoforms. The extent to which isoform-specific versus shared domains regulate distinct γ-Pcdh functions remains incompletely understood. Our previous in vitro studies identified protein kinase C (PKC) phosphorylation of a serine residue within a shared C-terminal motif as a mechanism through which γ-Pcdh promotion of dendrite arborization via myristoylated alanine-rich C-kinase substrate (MARCKS) is abrogated. Here, we used CRISPR/Cas9 genome editing to generate two new mouse lines expressing only non-phosphorylatable γ-Pcdhs, due either to a serine-to-alanine mutation (PcdhgS/A) or to a 15-amino acid C-terminal deletion resulting from insertion of an early stop codon (PcdhgCTD). Both lines are viable and fertile, and the density and maturation of dendritic spines remain unchanged in both PcdhgS/A and PcdhgCTD cortex. Dendrite arborization of cortical pyramidal neurons, however, is significantly increased in both lines, as are levels of active MARCKS. Intriguingly, despite having significantly reduced levels of γ-Pcdh proteins, the PcdhgCTD mutation yields the strongest phenotype, with even heterozygous mutants exhibiting increased arborization. The present study confirms that phosphorylation of a shared C-terminal motif is a key γ-Pcdh negative regulation point and contributes to a converging understanding of γ-Pcdh family function in which distinct roles are played by both individual isoforms and discrete protein domains.

A C-terminal motif containing a PKC phosphorylation site regulates γ-Protocadherin-mediated dendrite arborization in the cerebral cortex in vivo.

The Pcdhg gene cluster encodes 22 γ-Protocadherin (γ-Pcdh) cell adhesion molecules that critically regulate multiple aspects of neural development, including neuronal survival, dendritic and axonal arborization, and synapse formation and maturation. Each γ-Pcdh isoform has unique protein domains-a homophilically-interacting extracellular domain and a juxtamembrane cytoplasmic domain-as well as a C-terminal cytoplasmic domain shared by all isoforms. The extent to which isoform-specific vs. shared domains regulate distinct γ-Pcdh functions remains incompletely understood. Our previous in vitro studies identified PKC phosphorylation of a serine residue within a shared C-terminal motif as a mechanism through which γ-Pcdh promotion of dendrite arborization via MARCKS is abrogated. Here, we used CRISPR/Cas9 genome editing to generate two new mouse lines expressing only non-phosphorylatable γ-Pcdhs, due either to a serine-to-alanine mutation (PcdhgS/A) or to a 15-amino acid C-terminal deletion resulting from insertion of an early stop codon (PcdhgCTD). Both lines are viable and fertile, and the density and maturation of dendritic spines remains unchanged in both PcdhgS/A and PcdhgCTD cortex. Dendrite arborization of cortical pyramidal neurons, however, is significantly increased in both lines, as are levels of active MARCKS. Intriguingly, despite having significantly reduced levels of γ-Pcdh proteins, the PcdhgCTD mutation yields the strongest phenotype, with even heterozygous mutants exhibiting increased arborization. The present study confirms that phosphorylation of a shared C-terminal motif is a key γ-Pcdh negative regulation point, and contributes to a converging understanding of γ-Pcdh family function in which distinct roles are played by both individual isoforms and discrete protein domains.

[Inability of hospital computerised physician order entry systems to secure the use of concentrated potassium intravenous solutions]. / Incapacité des logiciels d'aide à la prescription hospitaliers à sécuriser l'utilisation des solutions concentrées de potassium injectable.

OBJECTIVES: To determine whether hospital computerised physician order entry (CPOE) systems contribute to securing intravenous potassium chloride (KCl) prescriptions with reference to the recommendations issued by French healthcare agencies. METHODS: We sent a questionnaire to the members of the Association pour le Digital et l'Information en Pharmacie. RESULTS: More than three quarters of the 84 responses received involving 23 CPOE systems indicate that it is possible to: prescribe an ampoule of concentrated potassium chloride 10% 10mL intravenously without any diluents (80%); prescribe 4g of KCl in a bag of 500mL of NaCl 0,9% (98%); prescribe a solution that contains 6 grams of KCl per liter (94%); prescribe the administration of an injectable ampoule orally by means of a free text comment (83%). Nearly half of the responses indicate that it is possible to prescribe: concentrated KCl ampoules as administration solvent (50%); an injectable vial to be administered by oral route (52%). CONCLUSION: At least 23 hospital CPOE systems are unable to secure the prescriptions of injectable KCl. This finding lifts the veil on an unthought, namely the role of CPOE systems in securing high-risk medications. In order to solve this problem, it should be mandatory that health information technology vendors pay particular attention to these drugs. With regard to injectable KCl, the utilisation of a dilution vehicle, maximum concentration and maximum infusion flow rate are the first four constraints to be satisfied.

A simple method to dramatically increase C. elegans germline microinjection efficiency.

Genome manipulation methods in C. elegans require microinjecting DNA or ribonucleoprotein complexes into the microscopic core of the gonadal syncytium. These microinjections are technically demanding and represent a key bottleneck for all genome engineering and transgenic approaches in C. elegans. While there have been steady improvements in the ease and efficiency of genetic methods for C. elegans genome manipulation, there have not been comparable advances in the physical process of microinjection. Here, we report a simple and inexpensive method for handling worms using a paintbrush during the injection process that nearly tripled average microinjection rates compared to traditional worm handling methods. We found that the paintbrush increased injection throughput by substantially increasing both injection speeds and post-injection survival rates. In addition to dramatically and universally increasing injection efficiency for experienced personnel, the paintbrush method also significantly improved the abilities of novice investigators to perform key steps in the microinjection process. We expect that this method will benefit the C. elegans community by increasing the speed at which new strains can be generated and will also make microinjection-based approaches less challenging and more accessible to personnel and labs without extensive experience.

A simple method to dramatically increase C. elegans germline microinjection efficiency.

Genome manipulation methods in C. elegans require microinjecting DNA or ribonucleoprotein complexes into the microscopic core of the gonadal syncytium. These microinjections are technically demanding and represent a key bottleneck for all genome engineering and transgenic approaches in C. elegans . While there have been steady improvements in the ease and efficiency of genetic methods for C. elegans genome manipulation, there have not been comparable advances in the physical process of microinjection. Here, we report a simple and inexpensive method for handling worms using a paintbrush during the injection process that nearly tripled average microinjection rates compared to traditional worm handling methods. We found that the paintbrush increased injection throughput by substantially increasing both injection speeds and post-injection survival rates. In addition to dramatically and universally increasing injection efficiency for experienced personnel, the paintbrush method also significantly improved the abilities of novice investigators to perform key steps in the microinjection process. We expect that this method will benefit the C. elegans community by increasing the speed at which new strains can be generated and will also make microinjection-based approaches less challenging and more accessible to personnel and labs without extensive experience.

The γ-Protocadherins Interact Physically and Functionally with Neuroligin-2 to Negatively Regulate Inhibitory Synapse Density and Are Required for Normal Social Interaction.

Cell adhesion molecules (CAMs) are key players in the formation of neural circuits during development. The γ-protocadherins (γ-Pcdhs), a family of 22 CAMs encoded by the Pcdhg gene cluster, are known to play important roles in dendrite arborization, axon targeting, and synapse development. We showed previously that multiple γ-Pcdhs interact physically with the autism-associated CAM neuroligin-1, and inhibit the latter's ability to promote excitatory synapse maturation. Here, we show that γ-Pcdhs can also interact physically with the related neuroligin-2, and inhibit this CAM's ability to promote inhibitory synapse development. In an artificial synapse assay, γ-Pcdhs co-expressed with neuroligin-2 in non-neuronal cells reduce inhibitory presynaptic maturation in contacting hippocampal axons. Mice lacking the γ-Pcdhs from the forebrain (including the cortex, the hippocampus, and portions of the amygdala) exhibit increased inhibitory synapse density and increased co-localization of neuroligin-2 with inhibitory postsynaptic markers in vivo. These Pcdhg mutants also exhibit defective social affiliation and an anxiety-like phenotype in behavioral assays. Together, these results suggest that γ-Pcdhs negatively regulate neuroligins to limit synapse density in a manner that is important for normal behavior.

CRISPR/Cas9 interrogation of the mouse Pcdhg gene cluster reveals a crucial isoform-specific role for Pcdhgc4.

The mammalian Pcdhg gene cluster encodes a family of 22 cell adhesion molecules, the gamma-Protocadherins (γ-Pcdhs), critical for neuronal survival and neural circuit formation. The extent to which isoform diversity-a γ-Pcdh hallmark-is required for their functions remains unclear. We used a CRISPR/Cas9 approach to reduce isoform diversity, targeting each Pcdhg variable exon with pooled sgRNAs to generate an allelic series of 26 mouse lines with 1 to 21 isoforms disrupted via discrete indels at guide sites and/or larger deletions/rearrangements. Analysis of 5 mutant lines indicates that postnatal viability and neuronal survival do not require isoform diversity. Surprisingly, given reports that it might not independently engage in trans-interactions, we find that γC4, encoded by Pcdhgc4, is the only critical isoform. Because the human orthologue is the only PCDHG gene constrained in humans, our results indicate a conserved γC4 function that likely involves distinct molecular mechanisms.

[Acceptability and effectiveness of immunotherapy in patients with melanoma]. / Acceptabilité et efficacité des immunothérapies dans le traitement du mélanome.

The immunotherapies known as "inhibitors of checkpoint" (ICP) are monoclonal antibodies used since 2010 and have dramatically modified the management of the advanced or metastatic melanomas. By reactivating the anti-tumoral immune response, these antibodies can activate the immune system in all the tissues with a risk to induce immune related adverse events (IrAE). Thus, the adverse effect's profile of ICP is considered as very different from that usually associated with conventional chemotherapies. The objectives of our retrospective monocentric study were the evaluation of the real life's safety and efficiency of the ipilimumab and the pembrolizumab in patients with an advanced melanoma. Seventy-two patients treated by ipilimumab and\or pembrolizumab between August 1st, 2008 and December 31st, 2016 were investigated. The main IrAE occurring involved the gastro- intestinal, skin, and the endocrine systems. The average onset time of IrAE was 39, 104 and 68 days, respectively and their respective duration was of 67, 50 and 111 days. There were 13 events of grade III and IV along with one death. The overall survival was 5 months for the patients treated in monotherapy with ipilimumab, and 14 months for those treated by pembrolizumab. Our real life's study tends to confirm the current safety profile of ICP treatment. Moreover and according to our analyses, the drug sequence seems to have a global survival impact.

Incidence, Predictors, and Impact on Six-Month Mortality of Three Different Definitions of Contrast-Induced Acute Kidney Injury After Coronary Angiography.

We assessed incidence, predictors, and impact on 6-month mortality of contrast-induced acute kidney injury (CI-AKI) after coronary angiography with or without percutaneous coronary intervention in patients with acute coronary syndrome (ACS), according to 3 different CI-AKI definitions. Serum creatinine (sCr) was assessed at baseline and 48 to 72 hours after procedure to classify patients into 3 CI-AKI groups: Group 1: increase in sCR ≥25% over baseline but absolute increase <0.5 mg/dl; Group 2: absolute increase ≥0.5 mg/dl; Group 3: absolute increase ≥0.3 mg/dl or ≥50% over baseline. The association between CI-AKI and all-cause 6-month mortality was assessed using multivariate Cox regression. Among 1,002 patients included, median age was 68 [57 to 79] years. The sample had the following characteristics: 70% men, 25% diabetics, 22% had a history of myocardial infarction, 21% had baseline estimated glomerular filtration rate (as calculated by the Modification of Diet in Renal Disease) <60 ml/min/1.72 m2, 34% had ST-segment elevation myocardial infarction, 61% underwent percutaneous coronary intervention, and 43% had multivessel disease. Based on changes in sCr, 89 patients (8.9%) were classified in Group 1; 69 (6.9%) in Group 2; and 157 (15.7%) in Group 3, whereas sCr did not increase >25% in the remaining 844 (84.2%). CI-AKI was significantly associated with 6-month all-cause mortality using the definitions for Group 2 (hazard ratio 3.1, 95% confidence interval [CI] 1.5 to 6.6, p = 0.002) and Group 3 (hazard ratio 2.03, 95% CI 1.03 to 4.0, p = 0.04), but not Group 1. In conclusion, based on the definition used for CI-AKI, CI-AKI is observed in 6% to 15.7% of patients. An increase of 25% over baseline sCr does not identify high-risk patients. CI-AKI defined as an increase in sCr >0.3 mg/dl identifies 15.7% of the population at 2-fold higher risk of mortality.