Texture and color enhancement imaging versus high definition white-light endoscopy for detection of colorectal neoplasia: a randomized trial.

BACKGROUND: Texture and color enhancement imaging (TXI) was recently proposed as a substitute for standard high definition white-light imaging (WLI) to increase lesion detection during colonoscopy. This international, multicenter randomized trial assessed the efficacy of TXI in detection of colorectal neoplasia. METHODS: Consecutive patients aged ≥ 40 years undergoing screening, surveillance, or diagnostic colonoscopies at five centers (Italy, Germany, Japan) between September 2021 and May 2022 were enrolled. Patients were randomly assigned (1:1) to TXI or WLI. Primary outcome was adenoma detection rate (ADR). Secondary outcomes were adenomas per colonoscopy (APC) and withdrawal time. Relative risks (RRs) adjusted for age, sex, and colonoscopy indication were calculated. RESULTS: We enrolled 747 patients (mean age 62.3 [SD 9.5] years, 50.2 % male). ADR was significantly higher with TXI (221/375, 58.9 %) vs. WLI (159/372, 42.7 %; adjusted RR 1.38 [95 %CI 1.20-1.59]). This was significant for ≤ 5 mm (RR 1.42 [1.16-1.73]) and 6-9 mm (RR 1.36 [1.01-1.83]) adenomas. A higher proportion of polypoid (151/375 [40.3 %] vs. 104/372 [28.0 %]; RR 1.43 [1.17-1.75]) and nonpolypoid (136/375 [36.3 %] vs. 102/372 [27.4 %]; RR 1.30 [1.05-1.61]) adenomas, and proximal (143/375 [38.1 %] vs. 111/372 [29.8 %]; RR 1.28 [1.05-1.57]) and distal (144/375 [38.4 %] vs. 98/372 [26.3 %]; RR 1.46 [1.18-1.80]) lesions were found with TXI. APC was higher with TXI (1.36 [SD 1.79] vs. 0.89 [SD 1.35]; incident rate ratio 1.53 [1.25-1.88]). CONCLUSIONS: TXI increased ADR and APC among patients undergoing colonoscopy for various indications. TXI increased detection of polyps < 10 mm, both in the proximal and distal colon, and may help to improve colonoscopy quality indicators.

Bariatric reduction system - BARS: device, technique and first clinical experience.

BACKGROUND: Roux-en-Y gastric by-pass (RYGB) is one of the most effective bariatric procedures, but the rate of weight regain (WR) can reach 63% after the second year. Enlargement of the gastrojejunal anastomosis is one of the reported causes. A newly CE-marked flexible endoscopic system, Bariatric Anastomotic Reduction System (BARS) (Ovesco Endoscopy, Tuebingen, Germany), derivative of the well-established endoscopic over-the-scope-clip (OTSC) clipping system, has been recently developed. It was tested in pre-clinical and preliminary clinical use for feasibility and effectiveness in bariatric anastomotic reduction. MATERIAL AND METHODS: Using a single-channel endoscope with external supplemental working channel, the BARS device captures the two limbs of the anastomosis, reducing its size, thus slowing food passage. After preclinical assessment, six patients with at least a 15% WR and the presence of an enlarged gastrojejunostomy > 20 mm were enrolled. The mean patient age was 49 years (range 24-67). Average interval between gastric bypass and BARS procedure: 8 years (4-13). RESULTS: All procedures were safely performed without complications. Mean procedure time: 52 min (37 - 75). Preliminary results: mean weight loss 6 kg (4-9) at a 3-month FU. CONCLUSIONS: BARS could be a promising endoscopic system in case of WR after gastric bypass due to enlargement of the anastomosis.

Diagnostic yield and miss rate of EndoRings in an organized colorectal cancer screening program: the SMART (Study Methodology for ADR-Related Technology) trial.

BACKGROUND AND AIMS: The EndoRings add-on has been claimed to improve adenoma detection at colonoscopy, but available data are inconsistent. When testing a new technology, parallel and crossover methodologies measure different outcomes, leaving uncertainty about their correspondence. The aims of this study were to compare the diagnostic yield and miss rate of the EndoRings for colorectal neoplasia. METHODS: Consecutive patients undergoing colonoscopy after a positive fecal immunochemical test (FIT) within an organized screening program in 7 Italian centers were randomized between a parallel (EndoRings or standard) or a crossover (EndoRings/standard or standard/EndoRings) methodology. Outcomes measures were the adenoma detection rate (ADR) and advanced adenoma detection rate (AADR) in the parallel arms and the miss rate of adenomas in the crossover arms. RESULTS: Of 958 eligible patients, 927 (317 EndoRings; 317 standard; 142 EndoRings/standard; 151 standard/Endo-Rings) were included in the final analysis. In the parallel arms (mean ADR, 51.3%; mean AADR, 25.4%), no difference between standard and EndoRings was found for both ADR (relative risk [RR], 1.10; 95% confidence interval [CI], 0.95-1.28) and AADR (RR, 1.16; 95% CI, 0.88-1.51), as well as for the mean number of adenomas and advanced adenomas per patient (EndoRings, 1.9 ± 1.3 and 1.0 ± 1.2; standard, 2.1 ± 1.5 and 1.0 ± 1.2; P = not significant for both comparisons). In the crossover arms, no difference in the miss rate for adenomas between EndoRings and standard was found at per polyp (RR, 1.43; 95% CI, 0.97-2.10) or per-patient analysis (24% vs 26%; P = .76). CONCLUSIONS: No statistically significant difference in diagnostic yield and miss rate between EndoRings and standard colonoscopy was detected in patients with a positive FIT result. A clinically relevant correspondence between miss and detection rates was shown, supporting a cause-effect relationship. (ISRCTN registry: ISRCTN10357435.).

Development of Blood-Brain Barrier Permeable Nanoparticles as Potential Carriers for Salvianolic Acid B to CNS.

The blood-brain barrier hinders the passage of systemically delivered therapeutics and the brain extracellular matrix limits the distribution and durability of locally delivered agents. Drug-loaded nanocarriers represent a promising strategy to overcome these barriers and address specific drug delivery challenges due to their small size and versatile design. We synthetized [fluorescent poly(ethyl-cyanoacrylate) nanoparticles coated with Tween 80 by an emulsion polymerization method to target and reach the brain after intravenous and intraperitoneal administration. Nanoparticles were characterized in terms of dimensional analysis, polydispersity and zeta potential (ζ-potential), morphology, encapsulation efficacy, and loading capacity. After intracerebral injection in healthy rats, nanoparticles were distributed within the injected hemisphere and mainly interacted with microglial cells, presumably involved in their clearance by phagocytosis. Furthermore, nanoparticles were able to pass the blood-brain barrier after systemic administration in rats, and the lack of toxicity in C57/B6 mice chronically administered was highlighted. The data obtained helped to clarify the nanoparticles distribution, accumulation, fate, and toxicity into the brain. The selected nanoparticles may represent a biocompatible promising carrier to be further investigated as brain delivery systems. Salvianolic acid B from Salvia miltiorrhiza is a promising molecule in the protection of degeneration in several animal models by various biological mechanisms, but its poor chemical stability and low bioavailability limits its clinical application for central nervous system neuronal injury and degeneration. Nanoparticles were loaded with salvianolic acid B obtaining an encapsulation efficacy and loading capacities of 98.70 % ± 0.45 and 53.3 % ± 0.24, respectively. They were suitable for parental administration because their mean diameter was smaller than 300 nm, with a polydispersity of 0.04 ± 0.03, and a ζ-potential of - 8.38 mV ± 3.87. The in vitro release of salvianolic acid B from the nanoparticles was sustained and prolonged during 8 h, suitable for a promising clinical application.

Albumin Nanoparticles for Brain Delivery: A Comparison of Chemical versus Thermal Methods and in†vivo Behavior.

Human serum albumin nanoparticles (NPs) have gained considerable attention owing to their high loading capacity for various drugs and the fact that they are well tolerated. The aim of this work was to investigate two different methods to produce NPs without the use of organic solvents and to obtain useful drug-delivery systems to cross the blood-brain barrier. NPs were obtained by coacervation, using both chemical and thermal cross-linking processes. They were developed and optimized to target brain tissues after parenteral administration in healthy rats. Furthermore, their distribution, cellular uptake, and fate were investigated in vivo after intracerebral injection in healthy rats. The toxicity of the developed carriers was estimated by behavioral tests. All NPs were chemically and physically characterized by dynamic light scattering, transmission electron microscopy, and high-performance liquid chromatography coupled with diode array and fluorimetric detectors. Their distribution and fate in the brain were evaluated by fluorescence microscopy. NPs were observed to be located in different brain tissues depending on the mode of injection, and did not induce an inflammatory response. Behavioral tests demonstrated no locomotor, explorative, or cognitive function impairment induced by the NPs.

Curative endoscopic submucosal dissection of large nonpolypoid superficial neoplasms in ulcerative colitis (with videos).

BACKGROUND: Endoscopic resection of superficial neoplasms in inflammatory bowel disease (IBD) is appropriate if a complete resection can be achieved. However, EMR is ineffective for large, nonpolypoid neoplasms in IBD due to submucosal fibrosis, and no data are available on the efficacy of endoscopic submucosal dissection (ESD). OBJECTIVE: To assess ESD feasibility and efficacy for large, nonpolypoid neoplasms in patients with IBD. DESIGN: Prospective case series. SETTING: Multicenter: Italian and Japanese centers. PATIENTS: Consecutive patients with long-standing ulcerative colitis and a superficial nonpolypoid neoplasm, >20 mm within the colitic mucosa. INTERVENTION: Neoplasm characterization and delineation by chromoscopy and narrow-band imaging. ESD performed according to the standard technique. MAIN OUTCOME MEASUREMENTS: Feasibility, safety, curative resection rates. RESULTS: Nine patients with 10 neoplasms were included (7 and 3 in the Italian and Japanese centers, respectively). Neoplasms were laterally spreading tumors-non-granular in 5 cases, in the left side of the colon in 7, had median size of 33 mm, and were associated with scar in 5 cases. Margin delineation was difficult in 5 cases. Submucosal fibrosis was present in 9 cases. ESD was en bloc with negative margins (R0) in 8 cases, and curative in 7. No endoscopic invisible dysplasia or cancer was found during the follow-up (median 24 months, range 6-72 months) at the resection site and elsewhere within the colitic mucosa. LIMITATIONS: Small series. CONCLUSION: ESD achieves curative resections in patients with IBD, but the procedure is difficult because of the high prevalence of submucosal fibrosis. Patients need to be accurately evaluated before resection and adhere to strict long-term follow-ups.

Oleuropein Aglycone: A Possible Drug against Degenerative Conditions. In Vivo Evidence of its Effectiveness against Alzheimer's Disease.

The amyloid plaques and neurofibrillary tangles found in the Alzheimer's disease (AD) brain arise as a result of self-assembly into fibrillar material of amyloid-ß protein (Aß) and hyperphosphorylated tau, respectively, through a pathological process starting with the appearance of aggregation nuclei and neurotoxic oligomers. Accordingly, the search of inhibitors of oligomer nucleation and growth is considered a promising target to prevent amyloid toxicity. In recent years, a number of dietary factors including antioxidants, vitamins, and polyphenols have been characterized for their ability to protect cells stressed by several factors including the presence of amyloid deposits as well as to inhibit amyloid self-assembly and cytotoxicity and some of them are currently in clinical trial. The present review summarizes the findings on the beneficial effects against neurodegeneration and other peripheral inflammatory and degenerative diseases of oleuropein aglycone (OLE), a natural phenol abundant in the extra virgin olive oil. The data presently available suggest that OLE could provide a protective and therapeutic effect against a number of pathologies, including AD as well as obesity, type 2 diabetes, non-alcoholic hepatitis, and other natural or experimentally-induced pathological conditions. Such a protection could result, at least in part, in a remarkable improvement of the pathological signs arising from stress conditions including oxidative stress, an excessive inflammatory response, and the presence of cytotoxic aggregated material. In particular, the recent data on the cellular and molecular correlates of OLE neuroprotection suggest it could also play a therapeutic role against AD.

Oleuropein aglycone protects against pyroglutamylated-3 amyloid-ß toxicity: biochemical, epigenetic and functional correlates.

Amyloid-ß (Aß) fragments, oligomeric Aß aggregates, and pyroglutamylated-Aß peptides, as well as epigenetic mechanisms and autophagy dysfunction all appear to contribute in various ways to Alzheimer's disease progression. We previously showed that dietary supplementation of oleuropein aglycone, a natural phenol abundant in the extra virgin olive oil, can be protective by reducing Aß42 deposits in the brain of young and middle-aged TgCRND8 mice. Here, we extended our study to aged TgCRND8 mice showing increased pE3-Aß in the brain deposits. We report that oleuropein aglycone is active against glutaminylcyclase-catalyzed pE3-Aß generation reducing enzyme expression and interferes both with Aß42 and pE3-Aß aggregation. Moreover, the phenol astonishingly activates neuronal autophagy even in mice at advanced stage of pathology, where it increases histone 3 and 4 acetylation, which matches both a decrease of histone deacetylase 2 expression and a significant improvement of synaptic function. The occurrence of these functional, epigenetic, and histopathologic beneficial effects even at a late stage of the pathology suggests that the phenol could be beneficial at the therapeutic, in addition to the prevention, level.

Employing Alzheimer disease animal models for translational research: focus on dietary components.

BACKGROUND: Translational research needs valid animal models of disease to discover new pathogenetic aspects and treatments. In Alzheimer's disease (AD), transgenic models are of great value for AD research and drug testing. OBJECTIVE: It was the aim of this study to analyze the power of dietary polyphenols against neurodegeneration by investigating the effects of oleuropein aglycone (OLE), the main phenol in the extra virgin olive oil (EVOO), a key component of the Mediterranean diet (MD), in a mouse model of amyloid-ß deposition. METHODS: TgCRND8 mice (3.5 months old), expressing the mutant KM670/671NL+V717F h-ßAPP695 transgene, and wild-type (wt) mice were used to study in vivo the effects of an 8-week dietary supplementation with OLE (50 mg/kg of diet) [Grossi et al: PLoS One 2013;8:e71702], following the European Communities Council Directive 86/609 (DL 116/92) and National Guidelines (permit number: 283/2012-B). RESULTS: OLE administration ameliorates memory dysfunction, raises a significant autophagic response in the cortex and promotes the proliferation of newborn cells in the subgranular zone of the dentate gyrus of the hippocampus. CONCLUSIONS: Our findings support the beneficial effects of EVOO and highlight the possibility that continuous intake of high doses of OLE, both as a nutraceutical or as a food integrator, may prevent/delay the appearance of AD and reduce the severity of its symptoms.

Oleuropein aglycone counteracts Aß42 toxicity in the rat brain.

Previous data have shown that oleuropein aglycone (OLE), the main secoiridoid phenol present in extra virgin olive oil, counteracts in vitro aggregation of the Aß42 peptide and protects cultured cells and model organisms against aggregates toxicity. In this study we investigated the relative tissue toxicity of Aß42 aggregated in vitro in the presence or in the absence of OLE by injecting the nucleus basalis magnocellularis (NBM) of adult male Wistar rats with a 1.5 µl solution containing OLE (450 µM) or Aß42 (50 µM) aggregated in the absence (oligomers) or in the presence of 450 µM OLE. Control rats were injected with vehicle (1.5 µl). Thirty days after injection, the number of choline acetyltransferase (ChAT)-positive neurons, glia reaction and the Aß peptide levels were detected by immunohistochemistry. An apparent reduction in the amount of soluble A11-positive oligomers was detected in the NBM injected with Aß42 aggregated with OLE, as compared with the NBM injected with Aß42 alone. In the latter case, the number of ChAT-positive neurons was significantly reduced (≈-33%) respect to that recorded in the NBM injected with phosphate buffer, OLE or Aß42 aggregated with OLE. A markedly attenuated Aß-induced astrocytes and microglia reaction was also found in the NBM injected with Aß42 aggregated with OLE. Altogether, these data provide additional support to the anti-aggregation, neuroprotective and anti-inflammatory activities of this natural phenol, confirming its beneficial properties against neurodegeneration.

The polyphenol oleuropein aglycone protects TgCRND8 mice against Aß plaque pathology.

The claimed beneficial effects of the Mediterranean diet include prevention of several age-related dysfunctions including neurodegenerative diseases and Alzheimer-like pathology. These effects have been related to the protection against cognitive decline associated with aging and disease by a number of polyphenols found in red wine and extra virgin olive oil. The double transgenic TgCRND8 mice (overexpressing the Swedish and Indiana mutations in the human amyloid precursor protein), aged 1.5 and 4, and age-matched wild type control mice were used to examine in vivo the effects of 8 weeks dietary supplementation of oleuropein aglycone (50 mg/kg of diet), the main polyphenol found in extra virgin olive oil. We report here that dietary supplementation of oleuropein aglycone strongly improves the cognitive performance of young/middle-aged TgCRND8 mice, a model of amyloid-ß deposition, respect to age-matched littermates with un-supplemented diet. Immunofluorescence analysis of cerebral tissue in oleuropein aglycone-fed transgenic mice showed remarkably reduced ß-amyloid levels and plaque deposits, which appeared less compact and "fluffy"; moreover, microglia migration to the plaques for phagocytosis and a remarkable reduction of the astrocyte reaction were evident. Finally, oleuropein aglycone-fed mice brain displayed an astonishingly intense autophagic reaction, as shown by the increase of autophagic markers expression and of lysosomal activity. Data obtained with cultured cells confirmed the latter evidence, suggesting mTOR regulation by oleuropein aglycone. Our results support, and provide mechanistic insights into, the beneficial effects against Alzheimer-associated neurodegeneration of a polyphenol enriched in the extra virgin olive oil, a major component of the Mediterranean diet.

Stepwise training in rectal and colonic endoscopic submucosal dissection with differentiated learning curves.

BACKGROUND: Endoscopic submucosal dissection (ESD) has revolutionized the resection of GI superficial neoplasms, but adoption in Western countries is significantly delayed. OBJECTIVE: To evaluate a stepwise colorectal endoscopic submucosal dissection (ESD) learning and operative training protocol. DESIGN: Prospective study in the Western setting. SETTING: This study took place in a nonacademic hospital with one endoscopist expert in therapeutic endoscopy but novice in ESD. PATIENTS: Indications for ESD were superficial neoplasms 20 mm and larger without ulcerations or fibrosis. INTERVENTION: Training consisted of 5 unsupervised ESDs on isolated stomach, an observation period at an ESD expert Japanese center, 1 supervised ESD on isolated stomach, and retraining on 1 rectal ESD under supervision. The operative training on patients was performed without supervision moving from the rectum to the colon according to the competence achieved. MAIN OUTCOME MEASUREMENTS: Competence was defined as an 80% en bloc resection rate plus a statistically significant reduction in operating time per square centimeter. Learning curves were calculated based on consecutive blocks of 5 procedures. RESULTS: From February 2009 to February 2012, 30 rectal and 30 colonic ESDs were performed. The rectal ESD learning curve showed that the en bloc resection rate was 80% after 5 procedures (P = not significant); the operating time per square centimeter significantly decreased after 20 procedures (P = .0079); perforation occurred in 1 patient. The colonic ESD learning curve showed that the en bloc resection rate was 80% after 20 procedures (P = not significant); the operating time per square centimeter significantly decreased after 20 procedures (P = .031); perforations occurred in 2 patients. LIMITATIONS: Single-center design. CONCLUSIONS: A minimal intensive training seems sufficient for endoscopists expert in therapeutic procedures to take up ESD in a not overly arduous incremental method with separate and sequential learning curves for the rectum and colon.

Aß plaque-associated glial reaction as a determinant of apoptotic neuronal death and cortical gliogenesis: a study in APP mutant mice.

The purpose of this study was to investigate the microglia-driven apoptosis and the Aß deposits triggered generation of new microglial cells in the neocortex of TgCRND8 mice. Three- and seven-month-old TgCRND8 mice, displaying an early and widespread amyloid deposition, respectively, were used. In 7-month-old TgCRND8 mice the Aß-associated glial reaction was accompanied by an intense immunoreactivity of both TNF-α and inducible nitric oxide synthase, increased immunoreactivity of the pro-apoptotic protein Bax and a decrease in levels of the anti-apoptotic protein Bcl-2.Cortical and hippocampal neurons of TgCRND8 mice displayed higher immunoreactivity and higher nuclear expression of the transcription factor NF-kB than controls. It is possible that such an increase could represent a defence/compensatory response to degeneration. These findings indicate that Aß deposits activate brain-resident microglia population and astrocytes, and induce overproduction of inflammatory mediators that enhance pro- and anti-apoptotic cascades. In both 3- and 7-month-old TgCRND8 mice apparent gliogenesis was present in the vicinity of Aß plaques in the neocortex, indicating that microglia have a high proliferative rate which might play a more complex role than previously acknowledge.

A comparison of the biochemical modifications caused by toxic and non-toxic protein oligomers in cells.

Peptides and proteins can convert from their soluble forms into highly ordered fibrillar aggregates, giving rise to pathological conditions ranging from neurodegenerative disorders to systemic amyloidoses. It is increasingly recognized that protein oligomers forming early in the process of fibril aggregation represent the pathogenic species in protein deposition diseases. The N-terminal domain of the HypF protein from Escherichia coli (HypF-N) has previously been shown to form, under distinct conditions, two types of HypF-N oligomers with indistinguishable morphologies but distinct structural features at the molecular level. Only the oligomer type exposing hydrophobic surfaces and possessing sufficient structural plasticity is toxic (type A), whereas the other type is benign to cultured cells (type B). Here we show that only type A oligomers are able to induce a Ca(2+) influx from the cell medium to the cytosol, to penetrate the plasma membrane, to increase intracellular reactive oxygen species production, lipid peroxidation and release of intracellular calcein, resulting in the activation of the apoptotic pathway. Remarkably, these oligomers can also induce a loss of cholinergic neurons when injected into rat brains. By contrast, markers of cellular stress and viability were unaffected in cultured and rat neuronal cells exposed to type B oligomers. The analysis of the time scales of such effects indicates that the difference of toxicity between the two oligomer types involve the early events of the toxicity cascade, shedding new light on the mechanism of action of protein oligomers and on the molecular targets for the therapeutic intervention against protein deposition diseases.

Lithium improves hippocampal neurogenesis, neuropathology and cognitive functions in APP mutant mice.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive deterioration of cognitive functions, extracellular ß-amyloid (Aß) plaques and intracellular neurofibrillary tangles within neocortex and hippocampus. Adult hippocampal neurogenesis plays an important role in learning and memory processes and its abnormal regulation might account for cognitive impairments associated with AD. METHODOLOGY/PRINCIPAL FINDINGS: The double transgenic (Tg) CRND8 mice (overexpressing the Swedish and Indiana mutations in the human amyloid precursor protein), aged 2 and 6 months, were used to examine in vivo the effects of 5 weeks lithium treatment. BrdU labelling showed a decreased neurogenesis in the subgranular zone of Tg mice compared to non-Tg mice. The decrease of hippocampal neurogenesis was accompanied by behavioural deficits and worsened with age and pathology severity. The differentiation into neurons and maturation of the proliferating cells were also markedly impaired in the Tg mice. Lithium treatment to 2-month-old Tg mice significantly stimulated the proliferation and neuron fate specification of newborn cells and fully counteracted the transgene-induced impairments of cognitive functions. The drug, by the inhibition of GSK-3ß and subsequent activation of Wnt/ß-catenin signalling promoted hippocampal neurogenesis. Finally, the data show that the lithium's ability to stimulate neurogenesis and cognitive functions was lost in the aged Tg mice, thus indicating that the lithium-induced facilitation of neurogenesis and cognitive functions declines as brain Aß deposition and pathology increases. CONCLUSIONS: Lithium, when given on time, stimulates neurogenesis and counteracts AD-like pathology.

Increased Dickkopf-1 expression in transgenic mouse models of neurodegenerative disease.

To investigate the role of the Wnt inhibitor Dickkopf-1 (DKK-1) in the pathophysiology of neurodegenerative diseases, we analysed DKK-1 expression and localization in transgenic mouse models expressing familial Alzheimer's disease mutations and a frontotemporal dementia mutation. A significant increase of DKK-1 expression was found in the diseased brain areas of all transgenic lines, where it co-localized with hyperphosphorylated tau-bearing neurons. In TgCRND8 mice, DKK-1 immunoreactivity was detected in neurons surrounding amyloid deposits and within the choline acetyltransferase-positive neurons of the basal forebrain. Active glycogen synthase kinase-3 (GSK-3) was found to co-localize with DKK-1 and phospho-tau staining. Downstream to GSK-3, a significant reduction in beta-catenin translocation to the nucleus, indicative of impaired Wnt signaling functions, was found as well. Cumulatively, our findings indicate that DKK-1 expression is associated with events that lead to neuronal death in neurodegenerative diseases and support a role for DKK-1 as a key mediator of neurodegeneration with therapeutic potential.

Clioquinol decreases amyloid-beta burden and reduces working memory impairment in a transgenic mouse model of Alzheimer's disease.

Clioquinol (CQ) is a "metal protein attenuating compound" that crosses the blood-brain barrier and binds, with high affinity, copper(II) and zinc(II), two metal ions critically involved in amyloid-beta aggregation and toxicity. CQ was recently proposed for the treatment of Alzheimer's disease, but controversial data have been reported so far concerning its real therapeutic advantages. We describe here results of chronic CQ treatment in the TgCRND8 mouse model of Alzheimer's disease. Remarkably, based on classical behavioral tests, CQ treatment was found to reverse, to a large extent, the working memory impairments that are characteristic of this mouse model. Pairwise, a significant reduction of amyloid-beta plaque burden, both in the cortex and in the hippocampus, was detected as well as an attenuation of astrogliosis. MALDI Mass Spectrometry Imaging technique revealed a specific localization of CQ in the above mentioned brain areas. Modest but significant effects on the absolute and relative brain concentrations of the three most important biometals (i.e., copper, zinc, and iron) were highlighted following CQ treatment. The pharmacological and mechanistic implications of the above findings are thoroughly discussed.

Combined treatment with atorvastatin and minocycline suppresses severity of EAE.

Multiple sclerosis (MS) is the most common inflammatory demyelinating disorder of the central nervous system (CNS). An approach to improve MS treatment is to identify a rational combination of new medications or existing therapies that impact different aspects of the disease process. Statins are effective in the treatment of MS animal models and are promising candidates for future treatment. Minocycline ameliorates clinical severity of experimental autoimmune encephalomyelitis (EAE) and exhibits several anti-inflammatory and neuroprotective activities. In this study, we tested whether the combination of these two drugs could produce beneficial effects in EAE mice immunized with myelin oligodendrocyte protein (MOG). Our findings show that combined treatment, compared to using the medications alone, resulted in a significant reduction in disease severity, in both the acute and chronic phases of the disease, along with attenuation of inflammation, demyelination and axonal loss. Stereological analysis revealed that the combined treatment significantly guarded against neuroinflammation and neurodegeneration. Moreover, a significant suppression of anti-MOG antibody production in animals treated with the two medications was found. In conclusion, our findings prove that this combination of drugs is neuroprotective and suppresses the severity of EAE. Furthermore, this pharmacological approach appears to be promising as a future therapeutic strategy to control MS.

Abnormal processing of tau in the brain of aged TgCRND8 mice.

Amyloid plaques and neurofibrillary tangles are the main histopathological hallmarks of Alzheimer's disease (AD). In the neocortex and hippocampus of aged TgCRND8 mice, tau is hyperphosphorylated at different sites recognized by PHF-1, AT100, AT8 and CP13 antibodies. Phospho-SAPK/JNK levels were increased in the tg mouse brain, where activated SAPK/JNK co-localizes with PHF-1-positive cells. Phosphorylated tau-positive cells showed Bielschowsky- and Thioflavine S-positive intraneuronal deposits. PHF-1 and nitrotyrosine immunoreactivity merged within neurons surrounding amyloid deposits in cortical and hippocampal areas and immunoprecipitation studies confirmed that tau is nitrosylated. Our findings, demonstrating the presence of hyperphosphorylated and nitrosylated tau protein as well as of insoluble aggregates after the onset of amyloid deposition in the TgCRND8 mouse brain, indicate that the abnormal processing of tau may occur subsequently to cerebral amyloidosis and that activation of SAPK/JNK and induction of nitrosative stress are the more likely connecting factors between amyloidosis and tauopathy in AD.