Targeted therapy of cognitive deficits in fragile X syndrome.

Breaking an impasse in finding mechanism-based therapies of neuropsychiatric disorders requires a strategic shift towards alleviating individual symptoms. Here we present a symptom and circuit-specific approach to rescue deficits of reward learning in Fmr1 knockout mice, a model of Fragile X syndrome (FXS), the most common monogenetic cause of inherited mental disability and autism. We use high-throughput, ecologically-relevant automated tests of cognition and social behavior to assess effectiveness of the circuit-targeted injections of designer nanoparticles, loaded with TIMP metalloproteinase inhibitor 1 protein (TIMP-1). Further, to investigate the impact of our therapeutic strategy on neuronal plasticity we perform long-term potentiation recordings and high-resolution electron microscopy. We show that central amygdala-targeted delivery of TIMP-1 designer nanoparticles reverses impaired cognition in Fmr1 knockouts, while having no impact on deficits of social behavior, hence corroborating symptom-specificity of the proposed approach. Moreover, we elucidate the neural correlates of the highly specific behavioral rescue by showing that the applied therapeutic intervention restores functional synaptic plasticity and ultrastructure of neurons in the central amygdala. Thus, we present a targeted, symptom-specific and mechanism-based strategy to remedy cognitive deficits in Fragile X syndrome.

Ability to share emotions of others as a foundation of social learning.

The natural habitats of most species are far from static, forcing animals to adapt to continuously changing conditions. Perhaps the most efficient strategy addressing this challenge consists of obtaining and acting upon pertinent information from others through social learning. We discuss how animals transfer information via social channels and what are the benefits of such exchanges, playing out on different levels, from theperception of socially delivered information to emotional sharing, manifesting themselves across different taxa of increasing biological complexity. We also discuss how social learning is influenced by different factors including pertinence of information for survival, the complexity of the environment, sex, genetic relatedness, and most notably, the relationship between interacting partners. The results appear to form a consistent picture once we shift our focus from emotional contagion as a prerequisite for empathy onto the role of shared emotions in providing vital information about the environment. From this point of view, we can propose approaches that are the most promising for further investigation of complex social phenomena, including learning from others.

[Post-radiation atypical vascular lesions and angiosarcoma: 11 cases]. / Lésions vasculaires atypiques et angiosarcomes post-radiothérapie : 11 cas.

BACKGROUND: Post-radiation atypical vascular lesions of the skin display clinical and morphological overlap with well-differentiated angiosarcomas, and correct diagnosis may be difficult. PATIENTS AND METHODS: We studied clinical, histological and immuno-histochemical aspects (CD31, CD34, D2-40 and VEGFR-3) of eight post-radiation atypical vascular lesions comparatively with three post-radiation angiosarcomas. RESULTS: All patients were female and received radiation therapy for breast carcinoma. On average, atypical vascular lesions occurred 4.3 years after radiation therapy and presented as small papulonodules or erythematous plaques. The clinical course after simple excision was benign. Histologically, they were relatively circumscribed lesions and showed slit-like vessels dissecting dermal collagen in all cases. On average, angiosarcomas occurred 5 years after radiation therapy and presented as more extensive lesions with a more aggressive clinical course. The lesions showed histological overlap with atypical vascular lesions, but were poorly circumscribed, with deeper invasion, cytological atypia and mitosis. Although the immuno-histochemical profiles were similar, expression of VEGFR-3 was greater in two cases of angiosarcoma. CONCLUSION: Post-radiation atypical vascular lesions are benign lesions that display clinical, histological and immuno-phenotypic overlap with well-differentiated angiosarcoma, and diagnosis requires good clinicopathological correlation. VEGFR-3 may be useful for differential diagnosis, as well as amplification of the MYC gene.

The novel immunosuppressive enzyme IL4I1 is expressed by neoplastic cells of several B-cell lymphomas and by tumor-associated macrophages.

We previously reported a strong IL4I1 gene expression in primary mediastinal B-cell lymphoma (PMBL) and recently identified the protein as a secreted L-phenylalanine oxidase, physiologically expressed by myeloid cells, which inhibits T-cell proliferation in vitro. Here, we analyzed the pattern of IL4I1 protein expression in 315 human lymphoid and non-lymphoid malignancies. Besides PMBL, IL4I1 expression in tumors was very frequent. IL4I1 was detected in tumor-associated macrophages from most of the tumors and in neoplastic cells from follicular lymphoma, classic and nodular lymphocyte predominant Hodgkin lymphomas and small lymphocytic lymphoma, three of which are germinal center derived. IL4I1-positive tumor cells were also detected in rare cases of solid cancers, mainly mesothelioma. The enzymatic activity paralleled protein expression, suggesting that IL4I1 is functional in vivo. Depending on the tumor type, IL4I1 may impact on different infiltrating lymphocyte populations with consequences on tumor evolution. In the particular case of follicular lymphoma cells, which are susceptible to antitumor cytotoxic T cells killing but depend on interactions with local T helper cells for survival, a high level of IL4I1 expression seems associated with the absence of bone marrow involvement and a better outcome. These findings plead for an evaluation of IL4I1 as a prognosis factor.