Microglial activation is an invariant feature of Alzheimer's disease (AD). It is noteworthy that cannabinoids are neuroprotective by preventing ␤-amyloid (A␤)-induced microglial activation both in vitro and in vivo. On the other hand, the phytocannabinoid cannabidiol (CBD) has shown anti-inflammatory properties in different paradigms. In the present study, we compared the effects of CBD with those of other cannabinoids on microglial cell functions in vitro and on learning behavior and cytokine expression after A␤ intraventricular administration to mice. CBD, CBD-and WIN-promoted primary microglia migration was blocked by CB 1 and/or CB 2 antagonists. JWH and HUinduced migration was blocked by a CB 2 antagonist only. All of the cannabinoids decreased lipopolysaccharide-induced nitrite generation, which was insensitive to cannabinoid antagonism. Finally, both CBD and WIN, after subchronic administration for 3 weeks, were able to prevent learning of a spatial navigation task and cytokine gene expression in ␤-amyloid-injected mice. In summary, CBD is able to modulate microglial cell function in vitro and induce beneficial effects in an in vivo model of AD. Given that CBD lacks psychoactivity, it may represent a novel therapeutic approach for this neurological disease.

Neural injury leads to inflammation and activation of microglia that in turn may participate in progression of neurodegeneration. The mechanisms involved in changing microglial activity from beneficial to chronic detrimental neuroinflammation are not known but reactive oxygen species (ROS) may be involved. We have addressed this question in Nrf2-knockout mice, with hypersensitivity to oxidative stress, submitted to daily inoculation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 4 weeks. Basal ganglia of these mice exhibited a more severe dopaminergic dysfunction than wild type littermates in response to MPTP. The amount of CD11b-positive/CD45-highly-stained cells, indicative of peripheral macrophage infiltration, did not increase significantly in response to MPTP. However, Nrf2-deficient mice exhibited more astrogliosis and microgliosis as determined by an increase in messenger RNA and protein levels for GFAP and F4/80, respectively. Inflammation markers characteristic of classical microglial activation, COX-2, iNOS, IL-6, and TNF-alpha were also increased and, at the same time, anti-inflammatory markers attributable to alternative microglial activation, such as FIZZ-1, YM-1, Arginase-1, and IL-4 were decreased. These results were confirmed in microglial cultures stimulated with apoptotic conditioned medium from MPP(+)-treated dopaminergic cells, further demonstrating a role of Nrf2 in tuning balance between classical and alternative microglial activation. This study demonstrates a crucial role of Nrf2 in modulation of microglial dynamics and identifies Nrf2 as molecular target to control microglial function in Parkinson's disease (PD) progression.

Retrograde messengers adjust the precise timing of neurotransmitter release from the presynapse, thus modulating synaptic efficacy and neuronal activity. 2-Arachidonoyl glycerol, an endocannabinoid, is one such messenger produced in the postsynapse that inhibits neurotransmitter release upon activating presynaptic CB(1) cannabinoid receptors. Cognitive decline in Alzheimer's disease is due to synaptic failure in hippocampal neuronal networks. We hypothesized that errant retrograde 2-arachidonoyl glycerol signalling impairs synaptic neurotransmission in Alzheimer's disease. Comparative protein profiling and quantitative morphometry showed that overall CB(1) cannabinoid receptor protein levels in the hippocampi of patients with Alzheimer's disease remain unchanged relative to age-matched controls, and CB(1) cannabinoid receptor-positive presynapses engulf amyloid-β-containing senile plaques. Hippocampal protein concentrations for the sn-1-diacylglycerol lipase α and β isoforms, synthesizing 2-arachidonoyl glycerol, significantly increased in definite Alzheimer's (Braak stage VI), with ectopic sn-1-diacylglycerol lipase β expression found in microglia accumulating near senile plaques and apposing CB(1) cannabinoid receptor-positive presynapses. We found that microglia, expressing two 2-arachidonoyl glycerol-degrading enzymes, serine hydrolase α/β-hydrolase domain-containing 6 and monoacylglycerol lipase, begin to surround senile plaques in probable Alzheimer's disease (Braak stage III). However, Alzheimer's pathology differentially impacts serine hydrolase α/β-hydrolase domain-containing 6 and monoacylglycerol lipase in hippocampal neurons: serine hydrolase α/β-hydrolase domain-containing 6 expression ceases in neurofibrillary tangle-bearing pyramidal cells. In contrast, pyramidal cells containing hyperphosphorylated tau retain monoacylglycerol lipase expression, although at levels significantly lower than in neurons lacking neurofibrillary pathology. Here, monoacylglycerol lipase accumulates in CB(1) cannabinoid receptor-positive presynapses. Subcellular fractionation revealed impaired monoacylglycerol lipase recruitment to biological membranes in post-mortem Alzheimer's tissues, suggesting that disease progression slows the termination of 2-arachidonoyl glycerol signalling. We have experimentally confirmed that altered 2-arachidonoyl glycerol signalling could contribute to synapse silencing in Alzheimer's disease by demonstrating significantly prolonged depolarization-induced suppression of inhibition when superfusing mouse hippocampi with amyloid-β. We propose that the temporal dynamics and cellular specificity of molecular rearrangements impairing 2-arachidonoyl glycerol availability and actions may differ from those of anandamide. Thus, enhanced endocannabinoid signalling, particularly around senile plaques, can exacerbate synaptic failure in Alzheimer's disease.

BackgroundAlzheimer's disease (AD) brain shows an ongoing inflammatory condition and non-steroidal anti-inflammatories diminish the risk of suffering the neurologic disease. Cannabinoids are neuroprotective and anti-inflammatory agents with therapeutic potential.MethodsWe have studied the effects of prolonged oral administration of transgenic amyloid precursor protein (APP) mice with two pharmacologically different cannabinoids (WIN 55,212-2 and JWH-133, 0.2 mg/kg/day in the drinking water during 4 months) on inflammatory and cognitive parameters, and on 18F-fluoro-deoxyglucose (18FDG) uptake by positron emission tomography (PET).ResultsNovel object recognition was significantly reduced in 11 month old Tg APP mice and 4 month administration of JWH was able to normalize this cognitive deficit, although WIN was ineffective. Wild type mice cognitive performance was unaltered by cannabinoid administration. Tg APP mice showed decreased 18FDG uptake in hippocampus and cortical regions, which was counteracted by oral JWH treatment. Hippocampal GFAP immunoreactivity and cortical protein expression was unaffected by genotype or treatment. In contrast, the density of Iba1 positive microglia was increased in Tg APP mice, and normalized following JWH chronic treatment. Both cannabinoids were effective at reducing the enhancement of COX-2 protein levels and TNF-α mRNA expression found in the AD model. Increased cortical β-amyloid (Aβ) levels were significantly reduced in the mouse model by both cannabinoids. Noteworthy both cannabinoids enhanced Aβ transport across choroid plexus cells in vitro.ConclusionsIn summary we have shown that chronically administered cannabinoid showed marked beneficial effects concomitant with inflammation reduction and increased Aβ clearance.

The study included 1848 diffuse large B-cell lymphoma (DLBCL)patients treated with chemotherapy/rituximab. The aims were to validate the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) and explore the effect of adding high Beta-2 microglobulin (β2M), primary extranodal presentation and intense treatment to the NCCN-IPI variables in order to develop an improved index. Comparing survival curves, NCCN-IPI discriminated better than IPI, separating four risk groups with 5-year overall survival rates of 93%, 83%, 67% and 49%, but failing to identify a true high-risk population. For the second aim the series was split into training and validation cohorts: in the former the multivariate model identified age, lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, Stage III-IV, and β2M as independently significant, whereas the NCCN-IPI-selected extranodal sites, primary extranodal presentation and intense treatments were not. These results were confirmed in the validation cohort. The Grupo Español de Linfomas/Trasplante de Médula ósea (GELTAMO)-IPI developed here, with 7 points, significantly separated four risk groups (0, 1-3, 4 or ≥5 points) with 11%, 58%, 17% and 14% of patients, and 5-year overall survival rates of 93%, 79%, 66% and 39%, respectively. In the comparison GELTAMO IPI discriminated better than the NCCN-IPI. In conclusion, GELTAMO-IPI is more accurate than the NCCN-IPI and has statistical and practical advantages in that the better discrimination identifies an authentic high-risk group and is not influenced by primary extranodal presentation or treatments of different intensity.

A subset of patients with advanced classical Hodgkin's lymphoma is refractory to standard therapies. Therefore, it is relevant to identify new biologically-based prognostic markers. Recently, tumor associated macrophages have been proposed as a factor that predicts survival, although contradictory results have also been reported. Here we analyzed four macrophage markers (CD68, CD163, LYZ, and STAT1) using immunohistochemistry and automated quantification, in two independent series of advanced classical Hodgkin's lymphoma (n=266 and 103 patients, respectively). Our results did not confirm that specific macrophage immunohistochemical markers could be used as surrogates for gene expression profiling studies. Survival analyses did not show correlation between CD163, LYZ or STAT1 and either failure-free or disease-specific survival. There was an association between CD68 and disease-specific survival, but it was not consistent in both series. In conclusion, individual tumor associated macrophage markers cannot be used to predict outcome before technical standardization and prospective validation in independent series of patients with comparable stages and treatments.Key words: Hodgkin's lymphoma, outcome, tumor associated macrophages. Hodgkin's lymphoma. Haematologica 2012;97(7): 1080-1084. doi:10.3324/haematol.2011 This is an open-access paper. Citation: Sánchez-Espiridión B, Martin-Moreno AM, Montalbán C, Medeiros LJ, Vega F, Younes A, Piris MA, and Garcia JF. Immunohistochemical markers for tumor associated macrophages and survival in advanced classical ABSTRACT © F e r r a t a S t o r t i F o u n d a t i o nstage disease who had a survival rate of 100%. These results suggest that semi-quantitative assessment of CD68 + TAMs can be used to identify patients at high risk of disease relapse or progression, as well as patients with early-stage disease with low risk for relapse who are currently over-treated.11 However, this approach has a major drawback as the number of low-risk patients in the Steidl et al. study was low because very few cases of cHL had less than 5% of TAM. Therefore, about 72% of cases in the original report fall into the high-risk group 10 and might be selected for alternative treatments.Similar results about the predictive value of TAM in cHL have recently been reported by other groups. 12,13 However, the consistency of IHC markers in different series has not been clearly confirmed.14,15 Differences in the composition of the case series, technical variability, and different cut offs for expression of TAM associated markers could, in part, explain these diverse results. Also, roles for Epstein-Barr virus (EBV) and age as confounding factors have been claimed, since both variables influence the host immune response and TAM composition. 12,16We recently used GEP to identify specific genes associated with treatment failure in cHL patients 8,17 including gene signatures associated with reactive cells in the microenvironment. This gene signature was related to outcome in a selected series of advanced s...

Summary The International Prognostic Index (IPI) is the most widely used score for non‐Hodgkin lymphoma but lacks the ability to identify a high‐risk population in diffuse large B‐cell lymphoma (DLBCL). Low absolute lymphocyte count and high monocytes have proved to be unfavourable factors. Red‐cell distribution width (RDW) has been associated with inflammation and beta‐2 microglobulin (B2M) with tumour load. The retrospective study included 992 patients with DLBCL treated with R‐CHOP. In the multivariate analysis, age, Eastern Cooperative Oncology Group performance status (ECOG‐PS), stage, bulky mass, B2M, RDW, and lymphocyte/monocyte ratio (LMR) were independently related to progression‐free survival (PFS). A new prognosis score was generated with these variables including age categorized into three groups (0, 1, 2 points); ECOG ≥ 3–4 with two; stage III/IV, bulky mass, high B2M, LMR < 2·25 and RDW > 0·96 with one each; for a maximum of 9. This score could improve the discrimination of a very high‐risk subgroup with five‐year PFS and overall survival (OS) of 19% and 24% versus 45% and 59% of R (revised)‐IPI respectively. This score also showed greater predictive ability than IPI. A new score is presented including complete blood cell count variables and B2M, which are readily available in real‐life practice without additional tests. Compared to R‐IPI, it shows a more precise high‐risk assessment and risk discrimination for both PFS and OS.

There is growing evidence that leptin is able to ameliorate Alzheimer's disease (AD)-like pathologies, including brain amyloid-β (Aβ) burden. In order to improve the therapeutic potential for AD, we generated a lentivirus vector expressing leptin protein in a self-inactivating HIV-1 vector (HIV-leptin), and delivered this by intra-cerebroventricular administration to APP/PS1 transgenic model of AD. Three months after intra-cerebroventricular administration of HIV-leptin, brain Aβ accumulation was reduced. By electron microscopy, we found that APP/PS1 mice exhibited deficits in synaptic density, which were partially rescued by HIV-leptin treatment. Synaptic deficits in APP/PS1 mice correlated with an enhancement of caspase-3 expression, and a reduction in synaptophysin levels in synaptosome preparations. Notably, HIV-leptin therapy reverted these dysfunctions. Moreover, leptin modulated neurite outgrowth in primary neuronal cultures, and rescued them from Aβ42-induced toxicity. All the above changes suggest that leptin may affect multiple aspects of the synaptic status, and correlate with behavioral improvements. Our data suggest that leptin gene delivery has a therapeutic potential for Aβ-targeted treatment of mouse model of AD.