Montelukast improves disease outcome in SOD1G93A female mice by counteracting oligodendrocyte dysfunction and aberrant glial reactivity.

BACKGROUND AND PURPOSE: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive motor neuron (MN) loss and consequent muscle atrophy, for which no effective therapies are available. Recent findings reveal that disease progression is fuelled by early aberrant neuroinflammation and the loss of oligodendrocytes with neuroprotective and remyelinating properties. On this basis, pharmacological interventions capable of restoring a pro-regenerative local milieu and re-establish proper oligodendrocyte functions may be beneficial. EXPERIMENTAL APPROACH: Here, we evaluated the in vivo therapeutic effects of montelukast (MTK), an antagonist of the oligodendroglial G protein-coupled receptor 17 (GPR17) and of cysteinyl-leukotriene receptor 1 (CysLT1R) receptors on microglia and astrocytes, in the SOD1G93A ALS mouse model. We chronically treated SOD1G93A mice with MTK, starting from the early symptomatic disease stage. Disease progression was assessed by behavioural and immunohistochemical approaches. KEY RESULTS: Oral MTK treatment significantly extended survival probability, delayed body weight loss and ameliorated motor functionalityonly in female SOD1G93A mice. Noteworthy, MTK significantly restored oligodendrocyte maturation and induced significant changes in the reactive phenotype and morphological features of microglia/macrophages and astrocytes in the spinal cord of female SOD1G93A mice, suggesting enhanced pro-regenerative functions. Importantly, concomitant MN preservation has been detected after MTK administration. No beneficial effects were observed in male mice, highlighting a sex-based difference in the protective activity of MTK. CONCLUSIONS AND IMPLICATIONS: Our results provide the first preclinical evidence indicating that repurposing of MTK, a safe and marketed anti-asthmatic drug, may be a promising sex-specific strategy for personalized ALS treatment.

Long-Term Follow-Up of Custom-Made Porous Hydroxyapatite Cranioplasties: Analysis of Infections in Adult and Pediatric Patients.

In neurosurgery, cranioplasty (CP) stands as a pivotal surgical intervention, particularly following head trauma or various neurosurgical interventions. This study scrutinizes the intricacies of CP, emphasizing its prevalence and associated complications, with a specific focus on custom-made porous hydroxyapatite (PHA) implants. The investigation spans 687 patients (with 80 patients of pediatric age, less than 14 years old) across 26 neurosurgical centers in five European countries. Methodologically, this study delves into patient characteristics, complications, and infection data through a comprehensive post-marketing on-site surveillance approach. Notably, infections emerged as the primary complication, affecting 41 patients (6% of implants) with a clear distinction in onset patterns between pediatric (with more infections, 10% versus 5.4% in adults and an earlier onset of complications) and adult populations. Out of these 41 cases, cranioplasty explantation was required in 30 patients, 4.4% of the total population. Furthermore, bifrontal decompression correlated with a significantly elevated infection risk as compared to unilateral decompression (12.5% versus 5.1%) which remains after the examination of possible confounding factors. These findings provide substantial insights into the complexities of CP, suggesting the necessity for tailored strategies in pediatric and adult cases and cautioning against bifrontal decompressions. Despite acknowledging limitations and calling for prospective studies with long term follow-up, this research advances our understanding of the use of PHA CP, guiding clinical decision-making and emphasizing the importance of customized approaches for diverse patient cohorts.

Expression of constitutively active FoxO3 in murine forebrain leads to a loss of neural progenitors.

Inactivation of FoxO proteins by phosphorylation is the result of a number of stimuli, including the insulin/IGF pathway. We were interested in the consequence of blunting this pathway by employing transgenic mice with tetracycline-controllable conditional expression of a constitutively active allele of FOXO3 under the control of the forebrain-specific CaMKIIα promoter. Although transgene-expressing mice were viable, brain weight was reduced by 30% in adult animals. Brains showed an isocortex compression with normal cortical layering, and a size reduction in regions known to depend on adult neurogenesis, i.e., the olfactory bulbs and the dentate gyrus. On postnatal activation of the transgene, adult neurogenesis was also severely affected. Investigating the molecular basis of this phenotype, we observed enhanced apoptosis starting from embryonic day E10.5 and a subsequent loss of progenitors in the ventricular/subventricular zones, but not in the isocortex or the striatum of adult mice. The enhanced apoptosis was accompanied by increased expression of PIK3IP1, which we identified as a direct transcriptional target of FOXO3. Transfection of Pik3ip1 into differentiating neural progenitors resulted in a significant reduction of viable cells. We therefore conclude that neural progenitors are particularly vulnerable to FOXO3-induced apoptosis, which is mediated by PIK3IP1, a negative PI3 kinase regulator.

Wound healing defect of Vav3-/- mice due to impaired {beta}2-integrin-dependent macrophage phagocytosis of apoptotic neutrophils.

Vav proteins are guanine-nucleotide exchange factors implicated in leukocyte functions by relaying signals from immune response receptors and integrins to Rho-GTPases. We here provide first evidence for a role of Vav3 for beta(2)-integrins-mediated macrophage functions during wound healing. Vav3(-/-) and Vav1(-/-)/Vav3(-/-) mice revealed significantly delayed healing of full-thickness excisional wounds. Furthermore, Vav3(-/-) bone marrow chimeras showed an identical healing defect, suggesting that Vav3 deficiency in leukocytes, but not in other cells, is causal for the impaired wound healing. Vav3 was required for the phagocytotic cup formation preceding macrophage phagocytosis of apoptotic neutrophils. Immunoprecipitation and confocal microscopy revealed Vav3 activation and colocalization with beta(2)-integrins at the macrophage membrane upon adhesion to ICAM-1. Moreover, local injection of Vav3(-/-) or beta(2)-integrin(CD18)(-/-) macrophages into wound margins failed to restore the healing defect of Vav3(-/-) mice, suggesting Vav3 to control the beta(2)-integrin-dependent formation of a functional phagocytic synapse. Impaired phagocytosis of apoptotic neutrophils by Vav3(-/-) macrophages was causal for their reduced release of active transforming growth factor (TGF)-beta(1), for decreased myofibroblasts differentiation and myofibroblast-driven wound contraction. TGF-beta(1) deficiency in Vav3(-/-) macrophages was causally responsible for the healing defect, as local injection of either Vav3-competent macrophages or recombinant TGF-beta(1) into wounds of Vav3(-/-) mice fully rescued the delayed wound healing.

IL-6-deficient mice show impaired inflammatory response in a model of myosin-induced experimental myositis.

Inflammatory/immune reactions against muscle cells are responsible for the damage in idiopathic inflammatory myopathies. We investigated the role of IL-6, a cytokine known to contribute to local leukocyte accumulation, in a model of myosin-induced experimental myositis. After injection of rabbit myosin in CFA/pertussis toxin, normal mice develop clinically evident muscle deficit and damage, as demonstrated by myofiber necrosis and leukocyte infiltration, while IL-6-deficient mice have no clinical or histological signs of muscle damage. This study evidences that selective deficiency of IL-6 directly or indirectly hinders the local inflammatory response and its harmful effects in this model of muscle damage.

TGF-beta 1 and IL-10 modulate IL-1 beta-induced membrane and soluble ICAM-1 in human myoblasts.

We have previously shown that interleukin (IL)-1 beta and other inflammatory cytokines are able to induce the expression of membrane and soluble intercellular adhesion molecule (ICAM)-1 on human myoblasts. In this paper we found that IL-10 and transforming growth factor (TGF)-beta 1 are able to prevent IL-1 beta-induced membrane and soluble ICAM-1 protein expression on human myoblasts, with different time courses. The effect of both cytokines is associated to a reduction in ICAM-1 mRNA. Our findings suggest that IL-10 and TGF-beta 1 are able to influence the inflammatory process in muscle tissue at least in part by means of control of membrane and soluble ICAM-1.

Anti-p110 autoantibodies identify a subtype of "seronegative" myasthenia gravis with prominent oculobulbar involvement.

Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and pathogenetic autoantibodies directed against the nicotinic acetylcholine receptor (seropositive myasthenia gravis; SPMG). Nearly 15% to 20% of MG patients do not have these antibodies (seronegative myasthenia gravis; SNMG), but several evidence indicate that these patients have circulating pathogenic autoantibodies directed against other muscle antigens. Using the TE671 rhabdomyosarcoma cell line as an antigen source, we analyzed sera from 63 SNMG and 26 SPMG patients and 26 healthy blood donors by FACS analysis. We found that 40 of 63 SNMG patients and only 1 of 26 SPMG patients had IgG binding to the TE671 cell line. None of the sera bound to the unrelated MRC5 cell line. To identify the antigen, we analyzed sera immunoreactivity in more detail by immunoprecipitation of biotinylated membrane proteins from TE671 cells. When the immunoprecipitated proteins were separated by SDS-PAGE electrophoresis and then transferred to nitrocellulose membranes, we found that SNMG IgG identify a band corresponding to a protein with a molecular weight of 110 kDa (P110), which is not recognized by seropositive MG sera. This anti-P110 immunoreactivity is significantly associated with a distinct clinical picture characterized by a prominent involvement of ocular and bulbar muscles, with frequent respiratory problems (p < 0.005), and is recognized by a specific antimuscle specific kinase (MuSK) antiserum. In a recent article, the presence of anti-MuSK antibodies was described in SNMG. Our results confirm the presence of these antibodies in SNMG and suggest that anti-P110/MuSK autoantibodies identify a subtype of SNMG in which the different pathogenesis induces the distinct clinical picture.