• Peptidic C3 inhibitors of the compstatin family (Cp40) efficiently prevent hemolysis and opsonization of PNH erythrocytes in vitro.• Pharmacokinetic studies show that sustained therapeutic concentrations can be achieved with both Cp40 and its PEGylated derivative, PEG-Cp40.Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement-mediated intravascular hemolysis due to the lack of CD55 and CD59 on affected erythrocytes. The anti-C5 antibody eculizumab has proven clinically effective, but uncontrolled C3 activation due to CD55 absence may result in opsonization of erythrocytes, possibly leading to clinically meaningful extravascular hemolysis. We investigated the effect of the peptidic C3 inhibitor, compstatin Cp40, and its long-acting form (polyethylene glycol [PEG]-Cp40) on hemolysis and opsonization of PNH erythrocytes in an established in vitro system. Both compounds demonstrated dose-dependent inhibition of hemolysis with IC 50 ∼4 mM and full inhibition at 6 mM. Protective levels of either Cp40 or PEG-Cp40 also efficiently prevented deposition of C3 fragments on PNH erythrocytes. We further explored the potential of both inhibitors for systemic administration and performed pharmacokinetic evaluation in nonhuman primates. A single intravenous injection of PEG-Cp40 resulted in a prolonged elimination half-life of >5 days but may potentially affect the plasma levels of C3. Despite faster elimination kinetics, saturating inhibitor concentration could be reached with unmodified Cp40 through repetitive subcutaneous administration. In conclusion, peptide inhibitors of C3 activation effectively prevent hemolysis and C3 opsonization of PNH erythrocytes, and are excellent, and potentially cost-effective, candidates for further clinical investigation. (Blood. 2014;123(13):2094-2101 IntroductionParoxysmal nocturnal hemoglobinuria (PNH) is a complex hematologic disorder characterized by the expansion of hematopoietic cells deficient in glycophosphatidylinositol-anchored surface proteins, including the complement regulators CD55 and CD59. 1 Affected erythrocytes suffer from uncontrolled complement activation on their surface, and subsequent membrane attack complex (MAC)-mediated intravascular hemolysis.2 The therapeutic anti-C5 antibody eculizumab (Soliris, Alexion) has proven effective in controlling intravascular hemolysis in vivo, leading to remarkable clinical benefit in a majority of PNH patients.3,4 Yet, persistent C3 activation occurring during eculizumab treatment may lead to progressive deposition of C3 fragments on affected erythrocytes and subsequent C3-mediated extravascular hemolysis, possibly limiting the hematologic benefit of anti-C5 treatment. 5,6 Thus, upstream inhibition of the complement cascade seems an appropriate strategy to improve the results of current complement-targeted treatment. 7,8 Indeed, it has been recently documented that protein inhibitors of the alternative pathway (AP) of complement activation, such as the CD21/factor H (FH) fusion protein TT30 (Alexion) or the engin...

The results suggest that Kalèdo could be an effective instrument to teach children about healthy diet. More research is needed to study the long term effect of this intervention.

Fe65 is a binding partner of the Alzheimer's ␤-amyloid precursor protein APP. The possible involvement of this protein in the cellular response to DNA damage was suggested by the observation that Fe65 null mice are more sensitive to genotoxic stress than WT counterpart. Fe65 associated with chromatin under basal conditions and its involvement in DNA damage repair requires this association. A known partner of Fe65 is the histone acetyltransferase Tip60. Considering the crucial role of Tip60 in DNA repair, we explored the hypothesis that the phenotype of Fe65 null cells depended on its interaction with Tip60. We demonstrated that Fe65 knockdown impaired recruitment of Tip60-TRRAP complex to DNA double strand breaks and decreased histone H4 acetylation. Accordingly, the efficiency of DNA repair was decreased upon Fe65 suppression. To explore whether APP has a role in this mechanism, we analyzed a Fe65 mutant unable to bind to APP. This mutant failed to rescue the phenotypes of Fe65 null cells; furthermore, APP/APLP2 suppression results in the impairment of recruitment of Tip60-TRRAP complex to DNA double strand breaks, decreased histone H4 acetylation and repair efficiency. On these bases, we propose that Fe65 and its interaction with APP play an important role in the response to DNA damage by assisting the recruitment of Tip60-TRRAP to DNA damage sites.Alzheimer ͉ APP ͉ DNA repair T he ␤-amyloid peptides, main constituents of senile plaques of Alzheimer disease (AD), derive from the proteolytic processing of a type I membrane protein, known as ␤-amyloid precursor protein (APP) (1). APP functions are not completely understood, and this knowledge could contribute, at least in principle, to the understanding of AD. Possible cues to study the functions of APP could emerge from the analysis of proteins interacting with the short APP cytosolic domain. Several reports indicated that this cytodomain interacts, among the others, with the Fe65 protein (2-4). The latter has the characteristics of an adaptor protein, whose distinctive traits are 3 protein-protein interaction domains, 1 WW and 2 PTB (PhosphoTyrosine Binding) domains (4). The PTB domain located in the C-terminal part of the protein (PTB2) interacts with the cytodomain of APP and of the 2 related proteins APLP1 and APLP2. Similarly, Fe65 has also been found associated with APP intracellular domain (AICD) (5), which is generated, together with the ␤-amyloid peptides, upon the cleavage of APP by secretases (1).Experimental evidence from cultured cells suggested 2 possible functions of Fe65, one depending on its presence in the cytosol and another one on its nuclear localization. APP-Fe65 complexes are present in neuronal growth cones (6) and regulate cell motility (7). Considering that Fe65 WW domain interacts with Mena (8) and APP also with mDab1 (9), these findings support the hypothesis that the APP-Fe65 complex is involved in actin-based membrane remodeling, neurite growth and/or synaptic plasticity. The analysis of the phenotypes of APP/APLP1/APLP2 triple KO ...

Multisystem inflammatory syndrome in children (MIS-C) is a rare, severe complication of COVID-19. A better knowledge of immunological, cellular, and genetic characteristics of MIS-C could help better understand the pathogenesis of the disease and contribute to identifying specific diagnostic biomarkers and develop targeted therapies. We studied 37 MIS-C children at hospital admission and 24 healthy controls analyzing serum cytokines (IFN-α, IFN-β, IFN-γ, IL-6, IL-10, IL-17A, IL-12p70 and TNF), lymphocyte populations by flow cytometry and 386 genes related to autoimmune diseases, autoinflammation and primary immunodeficiencies by NGS. MIS-C patients showed a significant increase of serum IFNγ (despite a significant reduction of activated Th1) and ILs, even if with a great heterogeneity among patients, revealing different pathways involved in MIS-C pathogenesis and suggesting that serum cytokines at admission may help to select the inflammatory pathways to target in each patient. Flow cytometry demonstrated a relevant reduction of T populations while the percentage of B cell was increased in agreement with an autoimmune pathogenesis of MIS-C. Genetic analysis identified variants in 34 genes and 83.3% of patients had at least one gene variant. Among these, 9 were mutated in more patients. Most genes are related to autoimmune diseases like ATM, NCF1, MCM4, FCN3, and DOCK8 or to autoinflammatory diseases associated to the release of IFNγ like PRF1, NOD2, and MEF. Thus, an incomplete clearance of the Sars-CoV2 during the acute phase may induce tissue damage and self-antigen exposure and genetic variants can predispose to hyper-reactive immune dysregulation events of MIS-C-syndrome. Type II IFN activation and cytokine responses (mainly IL-6 and IL-10) may cause a cytokine storm in some patients with a more severe acute phase of the disease, lymphopenia and multisystemic organ involvement. The timely identification of such patients with an immunocytometric panel might be critical for targeted therapeutic management.

To grant faithful chromosome segregation, the spindle assembly checkpoint (SAC) delays mitosis exit until mitotic spindle assembly. An exceedingly prolonged mitosis, however, promotes cell death and by this means antimicrotubule cancer drugs (AMCDs), that impair spindle assembly, are believed to kill cancer cells. Despite malformed spindles, cancer cells can, however, slip through SAC, exit mitosis prematurely and resist killing. We show here that the Fcp1 phosphatase and Wee1, the cyclin B-dependent kinase (cdk) 1 inhibitory kinase, play a role for this slippage/resistance mechanism. During AMCD-induced prolonged mitosis, Fcp1-dependent Wee1 reactivation lowered cdk1 activity, weakening SAC-dependent mitotic arrest and leading to mitosis exit and survival. Conversely, genetic or chemical Wee1 inhibition strengthened the SAC, further extended mitosis, reduced antiapoptotic protein Mcl-1 to a minimum and potentiated killing in several, AMCD-treated cancer cell lines and primary human adult lymphoblastic leukemia cells. Thus, the Fcp1-Wee1-Cdk1 (FWC) axis affects SAC robustness and AMCDs sensitivity.