Inflammatory bowel disease induces pathological α-synuclein aggregation in the human gut and brain.

AIMS: According to Braak's hypothesis, it is plausible that Parkinson's disease (PD) originates in the enteric nervous system (ENS) and spreads to the brain through the vagus nerve. In this work, we studied whether inflammatory bowel diseases (IBDs) in humans can progress with the emergence of pathogenic α-synuclein (α-syn) in the gastrointestinal tract and midbrain dopaminergic neurons. METHODS: We have analysed the gut and the ventral midbrain from subjects previously diagnosed with IBD and form a DSS-based rat model of gut inflammation in terms of α-syn pathology. RESULTS: Our data support the existence of pathogenic α-syn in both the gut and the brain, thus reinforcing the potential role of the ENS as a contributing factor in PD aetiology. Additionally, we have analysed the effect of a DSS-based rat model of gut inflammation to demonstrate (i) the appearance of P-α-syn inclusions in both Auerbach's and Meissner's plexuses (gut), (ii) an increase in α-syn expression in the ventral mesencephalon (brain) and (iii) the degeneration of nigral dopaminergic neurons, which all are considered classical hallmarks in PD. CONCLUSION: These results strongly support the plausibility of Braak's hypothesis and emphasise the significance of peripheral inflammation and the gut-brain axis in initiating α-syn aggregation and transport to the substantia nigra, resulting in neurodegeneration.

Galectin-3 shapes toxic alpha-synuclein strains in Parkinson's disease.

Parkinson's Disease (PD) is a neurodegenerative and progressive disorder characterised by intracytoplasmic inclusions called Lewy bodies (LB) and degeneration of dopaminergic neurons in the substantia nigra (SN). Aggregated α-synuclein (αSYN) is known to be the main component of the LB. It has also been reported to interact with several proteins and organelles. Galectin-3 (GAL3) is known to have a detrimental function in neurodegenerative diseases. It is a galactose-binding protein without known catalytic activity and is expressed mainly by activated microglial cells in the central nervous system (CNS). GAL3 has been previously found in the outer layer of the LB in post-mortem brains. However, the role of GAL3 in PD is yet to be elucidated. In post-mortem samples, we identified an association between GAL3 and LB in all the PD subjects studied. GAL3 was linked to less αSYN in the LB outer layer and other αSYN deposits, including pale bodies. GAL3 was also associated with disrupted lysosomes. In vitro studies demonstrate that exogenous recombinant Gal3 is internalised by neuronal cell lines and primary neurons where it interacts with endogenous αSyn fibrils. In addition, aggregation experiments show that Gal3 affects spatial propagation and the stability of pre-formed αSyn fibrils resulting in short, amorphous toxic strains. To further investigate these observations in vivo, we take advantage of WT and Gal3KO mice subjected to intranigral injection of adenovirus overexpressing human αSyn as a PD model. In line with our in vitro studies, under these conditions, genetic deletion of GAL3 leads to increased intracellular αSyn accumulation within dopaminergic neurons and remarkably preserved dopaminergic integrity and motor function. Overall, our data suggest a prominent role for GAL3 in the aggregation process of αSYN and LB formation, leading to the production of short species to the detriment of larger strains which triggers neuronal degeneration in a mouse model of PD.

Galectin-3, a novel endogenous TREM2 ligand, detrimentally regulates inflammatory response in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease in which the formation of extracellular aggregates of amyloid beta (Aß) peptide, fibrillary tangles of intraneuronal tau and microglial activation are major pathological hallmarks. One of the key molecules involved in microglial activation is galectin-3 (gal3), and we demonstrate here for the first time a key role of gal3 in AD pathology. Gal3 was highly upregulated in the brains of AD patients and 5xFAD (familial Alzheimer's disease) mice and found specifically expressed in microglia associated with Aß plaques. Single-nucleotide polymorphisms in the LGALS3 gene, which encodes gal3, were associated with an increased risk of AD. Gal3 deletion in 5xFAD mice attenuated microglia-associated immune responses, particularly those associated with TLR and TREM2/DAP12 signaling. In vitro data revealed that gal3 was required to fully activate microglia in response to fibrillar Aß. Gal3 deletion decreased the Aß burden in 5xFAD mice and improved cognitive behavior. Interestingly, a single intrahippocampal injection of gal3 along with Aß monomers in WT mice was sufficient to induce the formation of long-lasting (2 months) insoluble Aß aggregates, which were absent when gal3 was lacking. High-resolution microscopy (stochastic optical reconstruction microscopy) demonstrated close colocalization of gal3 and TREM2 in microglial processes, and a direct interaction was shown by a fluorescence anisotropy assay involving the gal3 carbohydrate recognition domain. Furthermore, gal3 was shown to stimulate TREM2-DAP12 signaling in a reporter cell line. Overall, our data support the view that gal3 inhibition may be a potential pharmacological approach to counteract AD.

Eight-year survival in chronic hepatitis B patients under long-term entecavir or tenofovir therapy is similar to the general population.

BACKGROUND & AIMS: The effects of long-term antiviral therapy on survival have not been adequately assessed in chronic hepatitis B (CHB). In this 10-centre, ongoing cohort study, we evaluated the probability of survival and factors affecting survival in Caucasian CHB patients who received long-term entecavir/tenofovir therapy. METHODS: We included 1,951 adult Caucasians with CHB, with or without compensated cirrhosis and without hepatocellular carcinoma (HCC) at baseline, who received entecavir/tenofovir for ≥12 months (median, six years). Kaplan-Meier estimates of cumulative survival over time were obtained. Standardized mortality ratios (SMRs) were calculated by comparing death rates with those in the Human Mortality Database. RESULTS: The one-, five-, and eight-year cumulative probabilities were 99.7, 95.9, and 94.1% for overall survival, 99.9, 98.3, and 97.4% for liver-related survival, and 99.9, 97.8, and 95.8% for transplantation-free liver-related survival, respectively. Overall mortality was independently associated with older age and HCC development, liver-related mortality was associated with HCC development only, and transplantation-free liver-related mortality was independently associated with HCC development and lower platelet levels at baseline. Baseline cirrhosis was not independently associated with any type of mortality. Compared with the general population, in all CHB patients mortality was not significantly different (SMR 0.82), whereas it was lower in patients without HCC regardless of baseline cirrhosis (SMR 0.58) and was higher in patients who developed HCC (SMR 3.09). CONCLUSION: Caucasian patients with CHB and compensated liver disease who receive long-term entecavir/tenofovir therapy have excellent overall and liver-related eight-year survival, which is similar to that of the general population. HCC is the main factor affecting their overall mortality, and is the only factor affecting their liver-related mortality. LAY SUMMARY: Caucasian patients with chronic hepatitis B with or without compensated cirrhosis who receive long-term entecavir or tenofovir therapy have excellent overall eight-year survival, which is similar to that of the general population. Hepatocellular carcinoma is the main factor affecting their overall mortality, and is the only factor affecting liver-related mortality in this setting.

The risk of hepatocellular carcinoma decreases after the first 5 years of entecavir or tenofovir in Caucasians with chronic hepatitis B.

Whether there is a change of hepatocellular carcinoma (HCC) incidence in chronic hepatitis B patients under long-term therapy with potent nucleos(t)ide analogues is currently unclear. We therefore assessed the HCC incidence beyond year 5 of entecavir/tenofovir (ETV/TDF) therapy and tried to determine possible factors associated with late HCC occurrence. This European, 10-center, cohort study included 1,951 adult Caucasian chronic hepatitis B patients without HCC at baseline who received ETV/TDF for ≥1 year. Of them, 1,205 (62%) patients without HCC within the first 5 years of therapy have been followed for 5-10 (median, 6.8) years. HCCs have been diagnosed in 101/1,951 (5.2%) patients within the first 5 years and 17/1,205 (1.4%) patients within 5-10 years. The yearly HCC incidence rate was 1.22% within and 0.73% after the first 5 years (P = 0.050). The yearly HCC incidence rate did not differ within and after the first 5 years in patients without cirrhosis (0.49% versus 0.47%, P = 0.931), but it significantly declined in patients with cirrhosis (3.22% versus 1.57%, P = 0.039). All HCCs beyond year 5 developed in patients older than 50 years at ETV/TDF onset. Older age, lower platelets at baseline and year 5, and liver stiffness ≥12 kPa at year 5 were independently associated with more frequent HCC development beyond year 5 in multivariable analysis. No patient with low Platelets, Age, Gender-Hepatitis B score at baseline or year 5 developed HCC. CONCLUSION: The HCC risk decreases beyond year 5 of ETV/TDF therapy in Caucasian chronic hepatitis B patients, particularly in those with compensated cirrhosis; older age (especially ≥50 years), lower platelets, and liver stiffness ≥12 kPa at year 5 represent the main risk factors for late HCC development. (Hepatology 2017;66:1444-1453).

Validation of noninvasive methods to predict the presence of gastroesophageal varices in a cohort of patients with compensated advanced chronic liver disease.

BACKGROUND AND AIM: The aim was to validate noninvasive methods to predict the presence of gastroesophageal varices (GEV) in patients with suspected compensated advanced chronic liver disease. METHODS: We retrospectively reviewed clinical and radiological data collected prospectively between September 2013 and September 2015. We reviewed 442 consecutive patients with suspected compensated advanced chronic liver disease measured by transient elastography (TE) and a gastroscopy. We evaluated platelets, spleen diameter, TE, liver stiffness × spleen size/platelets (LSPS), variceal risk index (VRI), Baveno VI strategy, and Augustin algorithm. RESULTS: One hundred sixty-one out of 442 patients were included. Patients with GEV were compared with patients without GEV and showed statistically significant differences in platelet count (117 SD 51 vs 149 SD 62; P = 0.02), spleen diameter (13.0 SD 1.9 vs 11.5 SD 2; P = 0.003), and TE (28 SD 15 vs 19 SD 10; P = 0.001). Single methods (platelet count and TE) diagnosed correctly 51% and 71.4% of patients. Combined methods (LSPS, VRI, Baveno VI, and Augustin algorithm) diagnosed correctly 78%, 83.6%, 45.3%, and 57.1% of patients. Patients with GEV misdiagnosed: platelets 5/161 (3.1%), TE 6/161 (3.7%), LSPS 16/159 (10%), VRI 18/159 (11.3%), Baveno VI 3/161 (1.8%), and Augustin algorithm 6/161 (3.7%). Rate of unnecessary gastroscopies: platelets 46%, TE 25%, LSPS 13%, VRI 6%, Baveno VI 53%, and Augustin algorithm 39.1%. CONCLUSIONS: A significant number of patients were classified correctly using TE, LSPS, and VRI; however, LSPS and VRI had unacceptable rates of misdiagnoses. TE is the best noninvasive single method and the Baveno VI strategy the best combined method.

PAGE-B predicts the risk of developing hepatocellular carcinoma in Caucasians with chronic hepatitis B on 5-year antiviral therapy.

BACKGROUND & AIMS: Risk scores for hepatocellular carcinoma (HCC) developed in Asians offer poor-moderate predictability in Caucasian patients with chronic hepatitis B (CHB). This nine center cohort study aimed to develop and validate an accurate HCC risk score in Caucasian CHB patients treated with the current oral antivirals, entecavir/tenofovir. METHODS: We included 1815 adult Caucasians with CHB and no HCC at baseline who received entecavir/tenofovir for ⩾12 months. Using data from eight centers (derivation dataset, n=1325), a HCC risk score was developed based on multivariable Cox models and points system for simplification. Harrell's c-index was used as discrimination, bootstrap for internal validation and the data from the 9(th) and largest center (validation dataset, n=490) for external validation. RESULTS: The 5-year cumulative HCC incidence rates were 5.7% and 8.4% in the derivation and validation dataset, respectively. In the derivation dataset, age, gender, platelets and cirrhosis were independently associated with HCC. The PAGE-B score was developed based on age, gender and platelets (c-index=0.82, 0.81 after bootstrap validation). The addition of cirrhosis did not substantially improve the discrimination (c-index=0.84). The predictability of PAGE-B score was similar (c-index=0.82) in the validation dataset. Patients with PAGE-B ⩽9, 10-17, ⩾18 had 5-year cumulative HCC incidence rates of 0%, 3%, 17% in the derivation and 0%, 4%, 16% in the validation dataset. CONCLUSION: PAGE-B, which is based only on baseline patients' age, gender and platelets, represents a simple and reliable score for prediction of the 5-year HCC risk in Caucasian CHB patients under entecavir/tenofovir.

[Impact of the incorporation of a nurse in an inflammatory bowel disease unit]. / Impacto de la incorporación de la enfermera a una unidad de enfermedad inflamatoria intestinal.

INTRODUCTION: Multidisciplinary units are needed because of the growing complexity and volume of patients with inflammatory bowel disease (IBD). OBJECTIVES: To evaluate the healthcare, economic and research impact of incorporating a nurse into the IBD unit of the Puerta de Hierro Majadahonda University Hospital. METHODS: We prospectively recorded the activity carried out by the nurse of the IBD unit from March 2010 to December 2014. RESULTS: During this period, healthcare demand progressively increased, with 1,558 patients being attended by our unit. The healthcare provided by the nurse included 5,293 electronic mails and 678 telephone calls. We estimated that this activity represented a saving of 3,504 in-person medical consultations and 852 accident and emergency department visits. Other activities consisted of monitoring treatments with biological and non-biological agents (8,371 laboratory tests), extraction of 342 blood samples, follow-up of 1047 diagnostic tests and consultations with other medical specialties, health education in self-administration of drugs in 114 patients, the performance of 158 granulocyte apheresis procedures, and participation in 25 research projects. CONCLUSION: The incorporation of a specialised nurse in an IBD unit had major economic, healthcare and research benefits.

Safety and efficacy of triple therapy with peginterferon, ribavirin and boceprevir within an early access programme in Spanish patients with hepatitis C genotype 1 with severe fibrosis: SVRw12 analysis.

BACKGROUND & AIMS: The addition of protease inhibitors (PIs) changed the hepatitis C virus (HCV) treatment standards and improved sustained viral response (SVR) rates in patients with genotype 1 HCV infection. METHODS: Prospective, multicentre, national registry that includes naïve and treatment-experienced patients with HCV genotype 1 infection, who had bridging fibrosis or cirrhosis and were treated with triple therapy (peginterferon alfa-2a or alfa-2b, ribavirin and boceprevir) as compassionate use, and in accordance with the Summary of Product Characteristics. RESULTS: Most of the patients (68.2%) were male, with a mean age of 53 years, 75% (n = 128) had HCV 1b genotype and baseline viral load of 6.2 log. According to prior treatment, 20% of patients were treatment-naïve and 80% had received prior treatment. Approximately 36.5% of patients (n = 62) reported at least one serious adverse events (SAEs) (total SAEs = 103). The most common SAEs were neutropenia (57.6%), anaemia (47.6%) and grade 3 thrombopenia (25.9%). Patients with albumin <3.5 g/dl and bilirubin >2 mg/dl had an increased relative risk (greater than one-fold) for SAEs, including infections and hepatic decompensation. In the intent-to-treat analysis (n = 170), the overall percentage of patients with SVRw12 was 46.5%. In patients with 1 log decrease at week 4 (lead-in phase), the overall SVRw12 rate was 67.0%. In the patients initiating triple therapy with boceprevir (n = 139), the global response rate was 56.4%. In a multivariate analysis, an increased probability of achieving SVR was associated with response to prior treatment (relapsers), >1 log decrease in viral load in the lead-in phase and baseline albumin >3.5 g/dl. CONCLUSIONS: Triple therapy in patients with severe fibrosis/cirrhosis is associated with a higher rate of SAE and a lower rate in comparison with patients with mild disease. However, for patients with intact liver function, it could be considered as a treatment option, when other alternatives would not be available.

Galectin-3 depletion tames pro-tumoural microglia and restrains cancer cells growth.

Galectin-3 (Gal-3) is a multifunctional protein that plays a pivotal role in the initiation and progression of various central nervous system diseases, including cancer. Although the involvement of Gal-3 in tumour progression, resistance to treatment and immunosuppression has long been studied in different cancer types, mainly outside the central nervous system, its elevated expression in myeloid and glial cells underscores its profound impact on the brain's immune response. In this context, microglia and infiltrating macrophages, the predominant non-cancerous cells within the tumour microenvironment, play critical roles in establishing an immunosuppressive milieu in diverse brain tumours. Through the utilisation of primary cell cultures and immortalised microglial cell lines, we have elucidated the central role of Gal-3 in promoting cancer cell migration, invasion, and an immunosuppressive microglial phenotypic activation. Furthermore, employing two distinct in vivo models encompassing primary (glioblastoma) and secondary brain tumours (breast cancer brain metastasis), our histological and transcriptomic analysis show that Gal-3 depletion triggers a robust pro-inflammatory response within the tumour microenvironment, notably based on interferon-related pathways. Interestingly, this response is prominently observed in tumour-associated microglia and macrophages (TAMs), resulting in the suppression of cancer cells growth.

One sixth of Amazonian tree diversity is dependent on river floodplains.

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.

Mapping density, diversity and species-richness of the Amazon tree flora.

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution.

Peginterferon alpha-2a and ribavirin in patients with hepatitis C virus genotype 1 infection with persistently normal alanine aminotransferase levels.

BACKGROUND AND AIM: To evaluate the efficacy and safety of peginterferon α-2a plus ribavirin at standard doses in patients with hepatitis C virus (HVC) genotype 1 infection with persistently normal alanine aminotransferase (ALT) levels. METHODS: Patients aged 18 to 65 years were included in this observational, prospective study if they had evidence of a HCV genotype 1 infection. The serum HCV RNA concentration was determined at baseline and week 12. A qualitative HCV RNA test was performed at baseline and at weeks 48 and 72. Liver function tests were performed at each study visit. The primary efficacy measure was the sustained virological response in the intention-to-treat population. Logistic regression analyses were also performed to explore predictors of virological response. RESULTS: A sustained virological response was observed in 100 of the 175 patients (57%). An early virological response and end-of-treatment response were seen in 159 patients (91%) and 133 patients (76%), respectively. Thirty-seven of the 122 evaluable patients for this outcome (30%) showed a rapid virological response. A higher viral load was a significant predictor for a lack of rapid virological response and lack of sustained virological response. There were not any unexpected safety or tolerability findings. CONCLUSIONS: Our study suggests that the efficacy of the combination of peginterferon α-2a and ribavirin in patients with HCV genotype 1 infection and normal ALT levels is at least similar to that reported in patients with elevated ALT levels.

Inflammatory Animal Models of Parkinson's Disease.

Accumulating evidence suggests that microglia and peripheral immune cells may play determinant roles in the pathogenesis of Parkinson's disease (PD). Consequently, there is a need to take advantage of immune-related models of PD to study the potential contribution of microglia and peripheral immune cells to the degeneration of the nigrostriatal system and help develop potential therapies for PD. In this review, we have summarised the main PD immune models. From a historical perspective, we highlight first the main features of intranigral injections of different pro-inflammogens, including lipopolysaccharide (LPS), thrombin, neuromelanin, etc. The use of adenoviral vectors to promote microglia-specific overexpression of different molecules in the ventral mesencephalon, including α-synuclein, IL-1ß, and TNF, are also presented and briefly discussed. Finally, we summarise different models associated with peripheral inflammation whose contribution to the pathogenesis of neurodegenerative diseases is now an outstanding question. Illustrative examples included systemic LPS administration and dextran sulfate sodium-induced colitis in rodents.

Spleen Transient Elastography and Damping Index Identify a Subgroup of Patients Without an Acute or Chronic Response to Beta-Blockers.

Background and Aims: Monitoring of acute or chronic response to beta-blockers in patients with liver cirrhosis is based on the measurement of the HVPG. Our aim was to evaluate the response to beta-blockers with non-invasive techniques. Patients and Methods: This is a prospective observational study. Consecutive patients with an indication of primary or secondary prophylaxis of variceal bleeding who did not meet exclusion criteria were included. Acute response and chronic response were evaluated. Baseline and after acute and chronic response hepatosplenic measurements of TE and ARFI were obtained. Contrast-enhanced Doppler ultrasound was performed before and after acute and chronic responses. Results: From June 2015 to May 2018, 55 patients (14 with exclusion criteria) were included. We analyzed 41 patients, mean age 57 (SD: 8), 82.9% men, alcohol 43.9%, children A/B/C 78%/17.1%/4.9%, and 87.8% on primary prophylaxis. In all, the acute response was performed and was positive in 68.3% (CI 95: 55-85%). The chronic response was performed in 30 (73.2%) and was positive in 36.7% (CI 95: 18-55%). Basal measurements significantly related to acute response were spleen TE [responders 58.4 (SD: 23.0) KPa vs. non-responders 75 (SD: 0) KPa; p = 0.02] and damping index [non-responders 0.96 (0.8) vs. responders 0.44 (0.4), p = 0.01], and with chronic response, the spleen TE [responders 58.1 (SD: 21.4) KPa vs. non-responders 73.2 (SD: 5.5) KPa; p = 0.02], and damping index [non-chronic responders 0.8 (0.7) vs. chronic responders 0.4 (0.4), p = 0.04]. A spleen TE ≥ 74 KPa had a high sensitivity of 100% and specificity of 60% and a high NPV100% for predicting poor acute response to beta-blockers. The damping index > 0.6 showed moderate sensitivity of 67% and specificity of 69% with a high NPV of 82% for predicting poor acute response to beta-blockers. The combination of both measurements for predicting poor acute response to beta-blockers had an AUC of 0.8 (CI 95: 0.5-0.9). A spleen TE ≥ 74 KPa had a high sensitivity of 87% and specificity of 71% with a high NPV of 71% for predicting poor chronic response to beta-blockers. A damping index > 0.6 had moderate sensitivity of 60%, specificity of 82%, and NPV of 56% for predicting poor chronic response to beta-blockers. The combination of both measurements for predicting poor chronic response to beta-blockers had an AUC of 0.8 (CI 95: 0.7-0.9). Conclusion: Spleen TE and damping index can identify a subgroup of patients with poor acute or chronic response to beta-blockers.

APOE in the bullseye of neurodegenerative diseases: impact of the APOE genotype in Alzheimer's disease pathology and brain diseases.

ApoE is the major lipid and cholesterol carrier in the CNS. There are three major human polymorphisms, apoE2, apoE3, and apoE4, and the genetic expression of APOE4 is one of the most influential risk factors for the development of late-onset Alzheimer's disease (AD). Neuroinflammation has become the third hallmark of AD, together with Amyloid-ß plaques and neurofibrillary tangles of hyperphosphorylated aggregated tau protein. This review aims to broadly and extensively describe the differential aspects concerning apoE. Starting from the evolution of apoE to how APOE's single-nucleotide polymorphisms affect its structure, function, and involvement during health and disease. This review reflects on how APOE's polymorphisms impact critical aspects of AD pathology, such as the neuroinflammatory response, particularly the effect of APOE on astrocytic and microglial function and microglial dynamics, synaptic function, amyloid-ß load, tau pathology, autophagy, and cell-cell communication. We discuss influential factors affecting AD pathology combined with the APOE genotype, such as sex, age, diet, physical exercise, current therapies and clinical trials in the AD field. The impact of the APOE genotype in other neurodegenerative diseases characterized by overt inflammation, e.g., alpha- synucleinopathies and Parkinson's disease, traumatic brain injury, stroke, amyotrophic lateral sclerosis, and multiple sclerosis, is also addressed. Therefore, this review gathers the most relevant findings related to the APOE genotype up to date and its implications on AD and CNS pathologies to provide a deeper understanding of the knowledge in the APOE field.

Galectin-3, a rising star in modulating microglia activation under conditions of neurodegeneration.

The advent of high-throughput single-cell transcriptomic analysis of microglia has revealed different phenotypes that are inherently associated with disease conditions. A common feature of some of these activated phenotypes is the upregulation of galectin-3. Representative examples of these phenotypes include disease-associated microglia (DAM) and white-associated microglia (WAM), whose role(s) in neuroprotection/neurotoxicity is a matter of high interest in the microglia community. In this review, we summarise the main findings that demonstrate the ability of galectin-3 to interact with key pattern recognition receptors, including, among others, TLR4 and TREM2 and the importance of galectin-3 in the regulation of microglia activation. Finally, we discuss increasing evidence supporting the involvement of this lectin in the main neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, traumatic brain injury, and stroke.

Arginine deprivation alters microglial polarity and synergizes with radiation to eradicate non-arginine-auxotrophic glioblastoma tumors.

New approaches for the management of glioblastoma (GBM) are an urgent and unmet clinical need. Here, we illustrate that the efficacy of radiotherapy for GBM is strikingly potentiated by concomitant therapy with the arginine-depleting agent ADI-PEG20 in a non-arginine-auxotrophic cellular background (argininosuccinate synthetase 1 positive). Moreover, this combination led to durable and complete radiological and pathological response, with extended disease-free survival in an orthotopic immune-competent model of GBM, with no significant toxicity. ADI-PEG20 not only enhanced the cellular sensitivity of argininosuccinate synthetase 1-positive GBM to ionizing radiation by elevated production of nitric oxide (˙NO) and hence generation of cytotoxic peroxynitrites, but also promoted glioma-associated macrophage/microglial infiltration into tumors and turned their classical antiinflammatory (protumor) phenotype into a proinflammatory (antitumor) phenotype. Our results provide an effective, well-tolerated, and simple strategy to improve GBM treatment that merits consideration for early evaluation in clinical trials.

Galectin-3 Deletion Reduces LPS and Acute Colitis-Induced Pro-Inflammatory Microglial Activation in the Ventral Mesencephalon.

Parkinson's disease is a highly prevalent neurological disorder for which there is currently no cure. Therefore, the knowledge of risk factors as well as the development of new putative molecular targets is mandatory. In this sense, peripheral inflammation, especially the originated in the colon, is emerging as a predisposing factor for suffering this disease. We have largely studied the pleiotropic roles of galectin-3 in driving microglia-associated immune responses. However, studies aimed at elucidating the role of galectin-3 in peripheral inflammation in terms of microglia polarization are lacking. To achieve this, we have evaluated the effect of galectin-3 deletion in two different models of acute peripheral inflammation: intraperitoneal injection of lipopolysaccharide or gut inflammation induced by oral administration of dextran sodium sulfate. We found that under peripheral inflammation the number of microglial cells and the expression levels of pro-inflammatory mediators take place specifically in the dopaminergic system, thus supporting causative links between Parkinson's disease and peripheral inflammation. Absence of galectin-3 highly reduced neuroinflammation in both models, suggesting an important central regulatory role of galectin-3 in driving microglial activation provoked by the peripheral inflammation. Thus, modulation of galectin-3 function emerges as a promising strategy to minimize undesired microglia polarization states.