Mutations in the LRRK2 gene are the most common cause of genetic Parkinson’s disease. Although the mechanisms behind the pathogenic effects of LRRK2 mutations are still not clear, data emerging from in vitro and in vivo models suggests roles in regulating neuronal polarity, neurotransmission, membrane and cytoskeletal dynamics and protein degradation.We created mice lacking exon 41 that encodes the activation hinge of the kinase domain of LRRK2. We have performed a comprehensive analysis of these mice up to 20 months of age, including evaluation of dopamine storage, release, uptake and synthesis, behavioral testing, dendritic spine and proliferation/neurogenesis analysis.Our results show that the dopaminergic system was not functionally comprised in LRRK2 knockout mice. However, LRRK2 knockout mice displayed abnormal exploratory activity in the open-field test. Moreover, LRRK2 knockout mice stayed longer than their wild type littermates on the accelerated rod during rotarod testing. Finally, we confirm that loss of LRRK2 caused degeneration in the kidney, accompanied by a progressive enhancement of autophagic activity and accumulation of autofluorescent material, but without evidence of biphasic changes.

We report that CNS directed expression of Interferon (IFN) -γ results in basal ganglia calcification, reminiscent of human idiopathic basal ganglia calcification (IBGC), and nigrostriatal degeneration. Our results show that IFN-γ mediates age-progressive nigrostriatal degeneration in the absence of exogenous stressors. Further study of this model may provide unique insight into selective nigrostriatal degeneration in human IBGC and other Parkinson syndromes.

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Data demonstrate that short amyloid-β (Aβ) peptides are not toxic in vivo and can partially block toxicity associated with Aβ42 accumulation. Moore et al. further validate the use of γ-secretase modulators that lower Aβ42 and increase short Aβs as potential Alzheimer’s disease therapeutics.

There is considerable interest in harnessing innate immunity to treat Alzheimer's disease (AD). Here, we explore whether a decoy receptor strategy using the ectodomain of select TLRs has therapeutic potential in AD. AAV-mediated expression of human TLR5 ectodomain (sTLR5) alone or fused to human IgG4 Fc (sTLR5Fc) results in robust attenuation of amyloid β (Aβ) accumulation in a mouse model of Alzheimer-type Aβ pathology. sTLR5Fc binds to oligomeric and fibrillar Aβ with high affinity, forms complexes with Aβ, and blocks Aβ toxicity. Oligomeric and fibrillar Aβ modulates flagellin-mediated activation of human TLR5 but does not, by itself, activate TLR5 signaling. Genetic analysis shows that rare protein coding variants in human TLR5 may be associated with a reduced risk of AD. Further, transcriptome analysis shows altered TLR gene expression in human AD. Collectively, our data suggest that TLR5 decoy receptor-based biologics represent a novel and safe Aβ-selective class of biotherapy in AD.

We have used a single intensive chemotherapy regimen in the treatment of young patients with diffuse, aggressive, malignant lymphomas. There were two major histologic types of lymphoma in our series: lymphoblastic lymphomas, which presented most often with mediastinal tumor (64%), and undifferentiated lymphomas (mostly Burkitt’s lymphomas), which occurred predominantly in the abdomen (86%). Our objective was to examine the determinants of prognosis in a uniformly treated patient group that included 31 children (2–16 yr) and 34 young adults 17–35 yr). Patients with extensive bone marrow involvement (greater than 50% replacement by tumor cells) were included in the study. Treatment consisted essentially of a 4-drug combination (cytoxan, adriamycin, vincristine, and prednisone) alternating with a 42-hr methotrexate infusion, followed by leukovorin rescue, and included intrathecal prophylactic therapy against central nervous system (CNS) disease. Patients with localized or resected undifferentiated lymphoma received 6 therapy cycles; all other patients received 15 cycles. Radiation therapy was used only in exceptional circumstances. Fifty-eight of 65 patients (89%) achieved complete remission: 97% of children and 82% of adults. The estimated 3-yr survival was 60% (SE 6.4%) with a median follow-up of 3 yr. Analysis of factors associated with remission duration and survival indicated that bone marrow involvement at referral and extensive disease were poor prognostic variables. Patients with lymphoblastic lymphomas and patients with completely resected undifferentiated lymphomas had the best prognosis (81% +/- 12% and 94% +/- 6% estimated 3-yr survival, respectively). Patients with extensive intraabdominal undifferentiated lymphoma (stage D) had the worst prognosis (33% +/- 11% estimated 3 yr survival), but even in this subgroup, bone marrow involvement was an adverse factor (estimated survival in stage D patients with and without bone marrow involvement was 14% +/- 13% and 43% +/- 15%, respectively). Elevated uric acid and/or lactic dehydrogenase (LDH) were also of prognostic significance, but predominantly reflected state, i.e., extent of disease. Age did not significantly influence prognosis. In the undifferentiated lymphoma subgroup, histology (i.e., Burkitt's lymphoma versus non-Burkitt’s lymphoma) was not of prognostic significance. Total white count was below 1,000/cu mm in 39% of cycles, and fever associated with granulocytopenia occurred in 17% of cycles. Stomatitis of moderate to severe extent occurred in 50% of cycles.(ABSTRACT TRUNCATED AT 400 WORDS)

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Sixty-four patients with American Burkitt's lymphoma (AMBL) treated at the National Cancer Institute were reviewed to determine the frequency and characteristics of central nervous system (CNS) involvement. Patients with minimal or completely resected tumor never had CNS disease. Of the 45 patients with more extensive disease, 15 had CNS disease: nine presented with CNS disease, six of whom subsequently had recurrent CNS disease, and six developed CNS disease only at relapse. There was a significant association between CNS and bone-marrow disease at presentation. Therapy of CNS disease consisted of short courses of intrathecal chemotherapy with cytosine arabinoside and methotrexate. Cranial irradiation was given only to patients with CNS relapse. There are six long-term survivors (LTS) who have been disease free for four to six years post chemotherapy. Of these six LTS, three presented with CNS disease, two experienced isolated CNS relapse, and one had CNS disease both at presentation and at relapse. Three of the six LTS never received cranial irradiation. It is concluded that CNS involvement in AMBL can be effectively treated, and that long-term remission, which is probably cure, can be achieved.