Gut microbiota alterations promote traumatic stress susceptibility associated with p-cresol-induced dopaminergic dysfunctions.

Mounting evidence suggests a link between gut microbiota abnormalities and post-traumatic stress disorder (PTSD). However, whether and how the gut microbiota influences PTSD susceptibility is poorly understood. Here using the arousal-based individual screening model, we provide evidence for pre-trauma and post-trauma gut microbiota alterations in susceptible mice exhibiting persistent PTSD-related phenotypes. A more in-depth analysis revealed an increased abundance of bacteria affecting brain processes including myelination, and brain systems like the dopaminergic neurotransmission. Because dopaminergic dysfunctions play a key role in the pathophysiological mechanisms subserving PTSD, we assessed whether these alterations in gut microbiota composition could be associated with abnormal levels of metabolites inducing dopaminergic dysfunctions. We found high levels of the l-tyrosine-derived metabolite p-cresol exclusively in the prefrontal cortex of susceptible mice. We further uncovered abnormal levels of dopamine and DOPAC, together with a detrimental increase of dopamine D3 receptor expression, exclusively in the prefrontal cortex of susceptible mice. Conversely, we observed either resilience mechanisms aimed at counteracting these p-cresol-induced dopaminergic dysfunctions or myelination-related resilience mechanisms only in the prefrontal cortex of resilient mice. These findings reveal that gut microbiota abnormalities foster trauma susceptibility and thus it may represent a promising target for therapeutic interventions.

Immunomodulatory treatment in unclassifiable interstitial lung disease: A retrospective study of treatment response.

BACKGROUND AND OBJECTIVE: The optimal management of unclassifiable Interstitial lung disease (ILD) remains a challenge. The aim of this study was to describe pulmonary function trajectories for patients treated with immunomodulatory therapy and for untreated patients. METHODS: Clinical information and treatment data were obtained retrospectively at two ILD centres. Pulmonary function data were analysed using (1) mixed effects linear regression models with and without clinical covariates and (2) propensity score matching using gender, age, physiology (GAP) stage, smoking and presence of ground glass opacities. RESULTS: Sixty-five percent of the 249 patients included received corticosteroids and/or other immunomodulators. Treated patients had lower forced vital capacity (FVC) (72% vs. 83% predicted) and diffusing capacity for carbon monoxide (DLco) (44% vs. 60% predicted). In mixed effects linear regression, the adjusted change in FVC was -0.22%, [-0.34; -0.11], and -0.15% [-0.28;-0.012] for DLco. The difference in pulmonary function decline between treated and untreated patients was insignificant, -0.082% per month, [-0.28; 0.11], p = 0.10 for FVC and -0.14% per month, [-0.36; 0.079], p = 0.15, for DLco. In propensity score matched analysis, the difference in change in FVC was 0.039% per month, p = 0.12, and for DLco, 0.0085% per month, p = 0.7. CONCLUSION: The pulmonary function trajectories for treated and untreated patients were parallel, despite treated patients having more severe disease at baseline. The persisting differences between the groups suggest no overall effect, although improvement or stabilization may be seen in some patients. Prospective studies are needed to define subsets of patients with unclassifiable interstitial lung disease and their optimal management.

The Role of Dopamine D3 Receptors, Dysbindin, and Their Functional Interaction in the Expression of Key Genes for Neuroplasticity and Neuroinflammation in the Mouse Brain.

Cognitive impairment in schizophrenia remains a clinically and pharmacologically unsolved challenge. Clinical and preclinical studies have revealed that the concomitant reduction in dysbindin (DYS) and dopamine receptor D3 functionality improves cognitive functions. However, the molecular machinery underlying this epistatic interaction has not yet been fully elucidated. The glutamate NMDA receptors and the neurotrophin BDNF, with their established role in promoting neuroplasticity, may be involved in the complex network regulated by the D3/DYS interaction. Furthermore, as inflammation is involved in the etiopathogenesis of several psychiatric diseases, including schizophrenia, the D3/DYS interaction may affect the expression levels of pro-inflammatory cytokines. Thus, by employing mutant mice bearing selective heterozygosis for D3 and/or DYS, we provide new insights into the functional interactions (single and synergic) between these schizophrenia susceptibility genes and the expression levels of key genes for neuroplasticity and neuroinflammation in three key brain areas for schizophrenia: the prefrontal cortex, striatum, and hippocampus. In the hippocampus, the epistatic interaction between D3 and DYS reversed to the wild-type level the downregulated mRNA levels of GRIN1 and GRIN2A were observed in DYS +/- and D3 +/- mice. In all the areas investigated, double mutant mice had higher BDNF levels compared to their single heterozygote counterparts, whereas D3 hypofunction resulted in higher pro-inflammatory cytokines. These results may help to clarify the genetic mechanisms and functional interactions involved in the etiology and development of schizophrenia.

Comorbidities in unclassifiable interstitial lung disease.

BACKGROUND: Comorbidities are common in interstitial lung diseases (ILD) and have an important association with survival, but the frequency and prognostic impact of comorbidities in unclassifiable interstitial lung disease (uILD) remains elusive. We aimed to describe the prevalence of comorbidities and assess the impact on survival in patients with uILD. Furthermore, we aimed to identify and characterize potential phenotypes based on clusters of comorbidities and examine their association with disease progression and survival. METHODS: Incident patients diagnosed with uILD were identified at two ILD referral centers in Denmark and Germany from 2003 to 2018. The diagnosis uILD was based on multidisciplinary team meetings. Clinical characteristics and comorbidities were extracted from ILD registries and patient case files. Survival analyses were performed using Cox regression analyses, disease progression was analyzed by linear mixed effects models, and clusters of comorbidities were analyzed using self-organizing maps. RESULTS: A total of 249 patients with uILD were identified. The cohort was dominated by males (60%), former (49%) or current (15%) smokers, median age was 70 years, mean FVC was 75.9% predicted, and mean DLCO was 49.9% predicted. One-year survival was 89% and three-year survival was 73%. Eighty-five percent of the patients had ≥ 1 comorbidities, 33% had ≥ 3 comorbidities and 9% had ≥ 5 comorbidities. The only comorbidity associated with excess mortality was dyslipidemia. No association between survival and number of comorbidities or the Charlson comorbidity index was observed. Three clusters with different comorbidities profiles and clinical characteristics were identified. A significant annual decline in FVC and DLCO % predicted was observed in cluster 1 and 2, but not in cluster 3. No difference in mortality was observed between the clusters. CONCLUSIONS: The comorbidity burden in uILD is lower than reported in other types of ILD and the impact of comorbidities on mortality needs further clarification. Three clusters with distinct comorbidity profiles were identified and could represent specific phenotypes. No difference in mortality was observed between clusters, but slower disease progression was observed in cluster 3. Better understanding of disease behavior and mortality will require further studies of subgroups of uILD with longer observation time.

"Usual" interstitial pneumonia with autoimmune features: a prospective study on a cohort of idiopathic pulmonary fibrosis patients.

OBJECTIVES: The classification interstitial pneumonia with autoimmune features (IPAF) includes patients with interstitial lung disease (ILD) associated with autoimmune characteristics insufficient to reach classification criteria for a specific autoimmune disease (SAD). These criteria are divided into three domains: clinical, serological and morphological. The latter domain does not include the usual interstitial pneumonia (UIP) pattern, which is deemed not to be significantly associated with SAD. Therefore, the enrolment of these patients is more difficult, requiring at least one item from both of the other domains. The objective of this study is to evaluate the rate of progression towards SAD of a cohort of UIP patients satisfying only one IPAF domain (we called this group "UIPAF") compared with classic idiopathic pulmonary fibrosis (IPF). METHODS: We prospectively enrolled IPF patients with radiologic and/or histologic UIP pattern, followed jointly by rheumatologists and pulmonologists from January 2017 to January 2021, with a minimum follow-up of 12 months. RESULTS: We enrolled 190 IPF patients, 38 (20%) of whom were classified as UIPAF. IPF and UIPAF patients were similar for general characteristics, severity and prognosis, at presentation and at annual check-up. However, 28.9% of UIPAF patients progressed towards SAD, compared with 2% of IPF patients (χ2=30.4, p≤0.0001). CONCLUSIONS: The association between a single clinical or serological domain of IPAF and UIP pattern is predictive for the development of a SAD if compared with isolated UIP. ILD can be the first manifestation of SAD, even with a UIP pattern, therefore, the morphological domain of IPAF criteria could be removed.

Molecular Effects of Chronic Exposure to Palmitate in Intestinal Organoids: A New Model to Study Obesity and Diabetes.

Intestinal cell dysfunctions involved in obesity and associated diabetes could be correlated with impaired intestinal cell development. To date, the molecular mechanisms underlying these dysfunctions have been poorly investigated because of the lack of a good model for studying obesity. The main aim of this study was to investigate the effects of lipotoxicity on intestinal cell differentiation in small intestinal organoid platforms, which are used to analyze the regulation of cell differentiation. Mouse intestinal organoids were grown in the presence/absence of high palmitate concentrations (0.5 mM) for 48 h to simulate lipotoxicity. Palmitate treatment altered the expression of markers involved in the differentiation of enterocytes and goblet cells in the early (Hes1) and late (Muc2) phases of their development, respectively, and it modified enterocytes and goblet cell numbers. Furthermore, the expression of enteroendocrine cell progenitors (Ngn3) and I cells (CCK) markers was also impaired, as well as CCK-positive cell numbers and CCK secretion. Our data indicate, for the first time, that lipotoxicity simultaneously influences the differentiation of specific intestinal cell types in the gut: enterocytes, goblet cells and CCK cells. Through this study, we identified novel targets associated with molecular mechanisms affected by lipotoxicity that could be important for obesity and diabetes therapy.

Increased monocyte count and red cell distribution width as prognostic biomarkers in patients with Idiopathic Pulmonary Fibrosis.

BACKGROUND: Idiopathic Pulmonary Fibrosis (IPF) represents a chronic lung disease with unpredictable course. METHODS: We aimed to investigate prognostic performance of complete blood count parameters in IPF. Treatment-naïve patients with IPF were retrospectively enrolled from two independent cohorts (derivation and validation) and split into subgroups (high and low) based on median baseline monocyte count and red cell distribution width (RDW). RESULTS: Overall, 489 patients (derivation cohort: 300, validation cohort: 189) were analyzed. In the derivation cohort, patients with monocyte count ≥ 0.60 K/µL had significantly lower median FVC%pred [75.0, (95% CI 71.3-76.7) vs. 80.9, (95% CI 77.5-83.1), (P = 0.01)] and DLCO%pred [47.5, (95% CI 44.3-52.3) vs. 53.0, (95% CI 48.0-56.7), (P = 0.02)] than patients with monocyte count < 0.60 K/µL. Patients with RDW ≥ 14.1% had significantly lower median FVC%pred [75.5, (95% CI 71.2-79.2) vs. 78.3, (95% CI 76.0-81.0), (P = 0.04)] and DLCO%pred [45.4, (95% CI 43.3-50.5) vs. 53.0, (95% CI 50.8-56.8), (P = 0.008)] than patients with RDW < 14.1%. Cut-off thresholds from the derivation cohort were applied to the validation cohort with similar discriminatory value, as indicated by significant differences in median DLCO%pred between patients with high vs. low monocyte count [37.8, (95% CI 35.5-41.1) vs. 45.5, (95% CI 41.9-49.4), (P < 0.001)] and RDW [37.9, (95% CI 33.4-40.7) vs. 44.4, (95% CI 41.5-48.9), (P < 0.001)]. Patients with high monocyte count and RDW of the validation cohort exhibited a trend towards lower median FVC%pred (P = 0.09) and significantly lower median FVC%pred (P = 0.001), respectively. Kaplan-Meier analysis in the derivation cohort demonstrated higher all-cause mortality in patients with high (≥ 0.60 K/µL) vs. low monocyte count (< 0.60 K/µL) [HR 2.05, (95% CI 1.19-3.53), (P = 0.01)]. CONCLUSIONS: Increased monocyte count and RDW may represent negative prognostic biomarkers in patients with IPF.

Dysregulation of miR-15a-5p, miR-497a-5p and miR-511-5p Is Associated with Modulation of BDNF and FKBP5 in Brain Areas of PTSD-Related Susceptible and Resilient Mice.

Post-traumatic stress disorder (PTSD) is a neuropsychiatric disorder occurring in susceptible individuals following a traumatic event. Understanding the mechanisms subserving trauma susceptibility/resilience is essential to develop new effective treatments. Increasing evidence suggests that non-coding RNAs, such as microRNAs (miRNAs), may play a prominent role in mediating trauma susceptibility/resilience. In this study, we evaluated the transcriptional expression of two key PTSD-related genes (FKBP5 and BDNF) and the relative targeting miRNAs (miR-15a-5p, miR-497a-5p, miR-511-5p, let-7d-5p) in brain areas of PTSD-related susceptible and resilient mice identified through our recently developed mouse model of PTSD (arousal-based individual screening (AIS) model). We observed lower transcript levels of miR-15a-5p, miR-497a-5p, and miR-511a-5p in the hippocampus and hypothalamus of susceptible mice compared to resilient mice, suggesting that the expression of these miRNAs could discriminate the two different phenotypes of stress-exposed mice. These miRNA variations could contribute, individually or synergically, to the inversely correlated transcript levels of FKBP5 and BDNF. Conversely, in the medial prefrontal cortex, downregulation of miR-15a-5p, miR-511-5p, and let-7d-5p was observed both in susceptible and resilient mice, and not accompanied by changes in their mRNA targets. Furthermore, miRNA expression in the different brain areas correlated to stress-induced behavioral scores (arousal score, avoidance-like score, social memory score and PTSD-like score), suggesting a linear connection between miRNA-based epigenetic modulation and stress-induced phenotypes. Pathway analysis of a miRNA network showed a statistically significant enrichment of molecular processes related to PTSD and stress. In conclusion, our results indicate that PTSD susceptibility/resilience might be shaped by brain-area-dependent modulation of miRNAs targeting FKBP5, BDNF, and other stress-related genes.

High Glucose Exposure Impairs L-Cell Differentiation in Intestinal Organoids: Molecular Mechanisms and Clinical Implications.

Intestinal organoids are used to analyze the differentiation of enteroendocrine cells (EECs) and to manipulate their density for treating type 2 diabetes. EEC differentiation is a continuous process tightly regulated in the gut by a complex regulatory network. However, the effect of chronic hyperglycemia, in the modulation of regulatory networks controlling identity and differentiation of EECs, has not been analyzed. This study aimed to investigate the effect of glucotoxicity on EEC differentiation in small intestinal organoid platforms. Mouse intestinal organoids were cultured in the presence/absence of high glucose concentrations (35 mM) for 48 h to mimic glucotoxicity. Chronic hyperglycemia impaired the expression of markers related to the differentiation of EEC progenitors (Ngn3) and L-cells (NeuroD1), and it also reduced the expression of Gcg and GLP-1 positive cell number. In addition, the expression of intestinal stem cell markers was reduced in organoids exposed to high glucose concentrations. Our data indicate that glucotoxicity impairs L-cell differentiation, which could be associated with decreased intestinal stem cell proliferative capacity. This study provides the identification of new targets involved in new molecular signaling mechanisms impaired by glucotoxicity that could be a useful tool for the treatment of type 2 diabetes.

Ongoing challenges in pulmonary fibrosis and insights from the nintedanib clinical programme.

The approvals of nintedanib and pirfenidone changed the treatment paradigm in idiopathic pulmonary fibrosis (IPF), and increased our understanding of the underlying disease mechanisms. Nonetheless, many challenges and unmet needs remain in the management of patients with IPF and other progressive fibrosing interstitial lung diseases.This review describes how the nintedanib clinical programme has helped to address some of these challenges. Data from this programme have informed changes to the IPF diagnostic guidelines, the timing of treatment initiation, and the assessment of disease progression. The use of nintedanib to treat patients with advanced lung function impairment, concomitant emphysema, patients awaiting lung transplantation and patients with IPF and lung cancer is discussed. The long-term use of nintedanib and an up-to-date summary of nintedanib in clinical practice are discussed. Directions for future research, namely emerging therapeutic options, precision medicine and other progressive fibrosing interstitial lung diseases, are described.Further developments in these areas should continue to improve patient outcomes.

The added value of comorbidities in predicting survival in idiopathic pulmonary fibrosis: a multicentre observational study.

BACKGROUND: The gender-age-physiology (GAP) model was developed to predict the risk of death. Comorbidities are common in idiopathic pulmonary fibrosis (IPF) and may impact on survival. We evaluated the ability of comorbidities to improve prediction of survival in IPF patients beyond the variables included in the GAP model. METHODS: We developed a prediction model named TORVAN using data from two independent cohorts. Continuous and point-score prediction models were developed with estimation of full and sparse versions of both. Model discrimination was assessed using the C-index and calibrated by comparing predicted and observed cumulative mortality at 1-5 years. RESULTS: Discrimination was similar for the sparse continuous model in the derivation and validation cohorts (C-index 71.0 versus 70.0, respectively), and significantly improved the performance of the GAP model in the validation cohort (increase in C-index of 3.8, p=0.001). In contrast, the sparse point-score model did not perform as well in the validation cohort (C-index 72.5 in the derivation cohort versus 68.1 in the validation cohort), but still significantly improved upon the performance of the GAP model (C-index increased by 2.5, p=0.037). CONCLUSIONS: The inclusion of comorbidities in TORVAN models significantly improved the discriminative performance in prediction of risk of death compared to GAP.

Dopaminergic-GABAergic interplay and alcohol binge drinking.

The dopamine D3 receptor (D3R), in the nucleus accumbens (NAc), plays an important role in alcohol reward mechanisms. The major neuronal type within the NAc is the GABAergic medium spiny neuron (MSN), whose activity is regulated by dopaminergic inputs. We previously reported that genetic deletion or pharmacological blockade of D3R increases GABAA α6 subunit in the ventral striatum. Here we tested the hypothesis that D3R-dependent changes in GABAA α6 subunit in the NAc affect voluntary alcohol intake, by influencing the inhibitory transmission of MSNs. We performed in vivo and ex vivo experiments in D3R knockout (D3R -/-) mice and wild type littermates (D3R +/+). Ro 15-4513, a high affinity α6-GABAA ligand was used to study α6 activity. At baseline, NAc α6 expression was negligible in D3R+/+, whereas it was robust in D3R-/-; other relevant GABAA subunits were not changed. In situ hybridization and qPCR confirmed α6 subunit mRNA expression especially in the NAc. In the drinking-in-the-dark paradigm, systemic administration of Ro 15-4513 inhibited alcohol intake in D3R+/+, but increased it in D3R-/-; this was confirmed by intra-NAc administration of Ro 15-4513 and furosemide, a selective α6-GABAA antagonist. Whole-cell patch-clamp showed peak amplitudes of miniature inhibitory postsynaptic currents in NAc medium spiny neurons higher in D3R-/- compared to D3R+/+; Ro 15-4513 reduced the peak amplitude in the NAc of D3R-/-, but not in D3R+/+. We conclude that D3R-dependent enhanced expression of α6 GABAA subunit inhibits voluntary alcohol intake by increasing GABA inhibition in the NAc.

Possible value of antifibrotic drugs in patients with progressive fibrosing non-IPF interstitial lung diseases.

BACKGROUND: Fibrosing, non-idiopathic pulmonary fibrosis (non-IPF) interstitial lung diseases (fILDs) are a heterogeneous group of diseases characterized by a different amount of inflammation and fibrosis. Therapy is currently based on corticosteroids and/or immunomodulators. However, response to these therapies is highly variable, sometimes without meaningful improvement, especially in more fibrosing forms. Pirfenidone and nintedanib have recently demonstrated to reduce functional decline in patients with IPF. However, their antifibrotic mechanism makes these two drugs an interesting approach for treatment of fibrosing ILDs other than IPF. OBJECTIVES: We here report our experience with antifibrotic drugs in fibrosing non-IPF ILDs patients having a progressive phenotype during immunosuppressive therapy. METHODS: Patients with a multidisciplinary team diagnosis of fibrosing non-IPF ILDs experiencing a progressive phenotype during treatment with corticosteroids and/or immunomodulators between October-2014 and January-2018 at our tertiary referral Center for ILDs were retrospectively analyzed. Antifibrotic therapy was administered after application with the respective health insurance company and after consent by the patient. Pulmonary-function-tests and follow-up visits were performed every 6 ± 1 months. RESULTS: Eleven patients were treated with antifibrotic drugs (8 males, mean age 62 ± 12.8 years, mean FVC% 62.8 ± 22.3, mean DLCO% 35.5 ± 10.7, median follow-up under antifibrotic treatment 11.1 months). Patients had a diagnosis of unclassifiable ILD in 6 cases, pleuroparenchymal fibroelastosis in 2 cases, idiopathic-NSIP in 1 case, asbestos-related ILD in 1 case and Hermansky-Pudlak syndrome in 1 case. Treatment before antifibrotics consisted of corticosteroids in all patients: 5 combined with Azathioprin, 1 with either methotrexate or cyclophosphamide (i.v.). Ten patients were treated with pirfenidone (2403 mg/die) and 1 with nintedanib (300 mg/die). Median FVC was 56, 56, 50%, at time points - 24, - 12, - 6 before initiation, 44% at time of initiation and 46.5% at 6 months after initiation of antifibrotic treatment. Antifibrotic treatment was generally well tolerated with a need of dose reduction in 2 cases (rash and nausea) and early termination in 3 cases. CONCLUSIONS: Antifibrotic treatment may be a valuable treatment option in patients with progressive fibrosing non-IPF ILD if currently no other treatment options exist. However, prospective, randomized clinical trials are urgently needed to assess the real impact of antifibrotic therapy in these patients.

Neurobiological links between depression and AD: The role of TGF-ß1 signaling as a new pharmacological target.

In the last several years a large number of studies have demonstrated the neurobiological and clinical continuum between depression and Alzheimer's disease (AD). Depression is a risk factor for the development of AD, and the presence of depressive symptoms significantly increases the conversion of Mild Cognitive Impairment (MCI) into AD. Common pathophysiological events have been identified in depression and AD, including neuroinflammation with an aberrant Tumor Necrosis Factor-α (TNF-α) signaling, and an impairment of Brain-Derived Neurotrophic Factor (BDNF) and Transforming-Growth-Factor-ß1 (TGF-ß1) signaling. TGF-ß1 is an anti-inflammatory cytokine that exerts neuroprotective effects against amyloid-ß (Aß)-induced neurodegeneration, and it has a key role in memory formation and synaptic plasticity. TGF-ß1 plasma levels are reduced in major depressed patients (MDD), correlate with depression severity, and significantly contribute to treatment resistance in MDD. The deficit of Smad-dependent TGF-ß1 signaling is also an early event in AD pathogenesis, which contributes to inflammaging and cognitive decline in AD. A long-term treatment with antidepressants such as selective-serotonin-reuptake inhibitors (SSRIs) is known to reduce the risk of AD in patients with depression and, SSRIs, such as fluoxetine, increase the release of TGF-ß1 from astrocytes and exert relevant neuroprotective effects in experimental models of AD. We propose the TGF-ß1 signaling pathway as a common pharmacological target in depression and AD, and discuss the potential rescue of TGF-ß1 signaling by antidepressants as a way to prevent the transition from depression to AD.

Comorbidities of IPF: How do they impact on prognosis.

Idiopathic Pulmonary Fibrosis (IPF) is a severe parenchymal lung disease characterized by an intense deposition of collagen in the interstitial spaces. The introduction of anti-fibrotic drugs increased patients' life expectancy highlighting the role of comorbidities in patients' management and prognosis. IPF is frequently associated with other diseases mainly because of its onset during middle age and sometimes because of the presence of common pathogenic pathways such as in the case of lung cancer. Comorbidities may differently influence prognosis of IPF patients. However, except for major impacting ones as LC, PH and cardiovascular diseases, data exploring their impact on prognosis are still few and sometimes conflicting highlighting the need of new large and targeted studies. In this review we discuss the current knowledge on the most common comorbidities associated with IPF (cardiovascular diseases, pulmonary hypertension, lung cancer, emphysema, gastro-oesophageal reflux and depression), focusing on their prognostic role.

The antineoplastic drug flavopiridol reverses memory impairment induced by Amyloid-ß1-42 oligomers in mice.

The ectopic re-activation of cell cycle in neurons is an early event in the pathogenesis of Alzheimer's disease (AD), which could lead to synaptic failure and ensuing cognitive deficits before frank neuronal death. Cytostatic drugs that act as cyclin-dependent kinase (CDK) inhibitors have been poorly investigated in animal models of AD. In the present study, we examined the effects of flavopiridol, an inhibitor of CDKs currently used as antineoplastic drug, against cell cycle reactivation and memory loss induced by intracerebroventricular injection of Aß1-42 oligomers in CD1 mice. Cycling neurons, scored as NeuN-positive cells expressing cyclin A, were found both in the frontal cortex and in the hippocampus of Aß-injected mice, paralleling memory deficits. Starting from three days after Aß injection, flavopiridol (0.5, 1 and 3mg/kg) was intraperitoneally injected daily, for eleven days. Here we show that a treatment with flavopiridol (0.5 and 1mg/kg) was able to rescue the loss of memory induced by Aß1-42, and to prevent the occurrence of ectopic cell-cycle events in the mouse frontal cortex and hippocampus. This is the first evidence that a cytostatic drug can prevent cognitive deficits in a non-transgenic animal model of AD.

Pharmacological enhancement of cholinergic neurotransmission alleviates neuroinflammation and improves functional outcomes in a triple transgenic mouse model of Alzheimer's disease.

Introduction: Alzheimer's disease (AD) is the most common neurodegenerative disorder affecting the elderly population worldwide. Due to the multifactorial nature of the disease, involving impairment of cholinergic neurotransmission and immune system, previous attempts to find effective treatments have faced challenges. Methods: In such scenario, we attempted to investigate the effects of alpha-glyceryl-phosphoryl-choline (α-GPC), a cholinomimetic molecule, on neuroinflammation and memory outcome in the triple transgenic mouse model of AD (3xTg-AD). Mice were enrolled at 4 months of age, treated orally with α-GPC dissolved in drinking water at a concentration resulting in an average daily dose of 100 mg/kg for 8 months and sacrificed at 12 months of age. Thereafter, inflammatory markers, as well as cognitive parameters, were measured. Results: Chronic α-GPC treatment reduced accumulation of amyloid deposits and led to a substantial re-balance of the inflammatory response of resident innate immune cells, astrocytes and microglia. Specifically, fluorescent immunohistochemistry and Western blot analysis showed that α-GPC contributed to reduction of cortical and hippocampal reactive astrocytes and pro-inflammatory microglia, concurrently increasing the expression of anti-inflammatory molecules. Whereas α-GPC beneficially affect the synaptic marker synaptophysin in the hippocampus. Furthermore, we observed that α-GPC was effective in restoring cognitive dysfunction, as measured by the Novel Object Recognition test, wherein 3xTg-AD mice treated with α-GPC significantly spent more time exploring the novel object compared to 3xTg-AD untreated mice. Discussion: In conclusion, chronic treatment with α-GPC exhibited a significant anti-inflammatory activity and sustained the key function of hippocampal synapses, crucial for the maintenance of a regular cognitive status. In light of our results, we suggest that α-GPC could be exploited as a promising therapeutic approach in early phases of AD.

Dopamine D3 Receptor, Cognition and Cognitive Dysfunctions in Neuropsychiatric Disorders: From the Bench to the Bedside.

The dopamine D3 receptor (D3R) plays a prominent role in the modulation of cognition in healthy individuals, as well as in the pathophysiological mechanism underlying the cognitive deficits affecting patients suffering from neuropsychiatric disorders. At a therapeutic level, a growing body of evidence suggests that the D3R blockade enhances cognitive and thus it may be an optimal therapeutic strategy against cognitive dysfunctions. However, this is not always the case because other ligands targeting the D3R, and behaving as partial agonists or biased agonists, may exert their pro-cognitive effect by maintaining adequate level of dopamine in key brain areas tuning cognitive performances. In this chapter, we review and discuss preclinical and clinical findings with the aim to remark the crucial role of the D3R in cognition and to strengthen the message that drugs targeting D3R may be excellent cognitive enhancers for the treatment of several neuropsychiatric and neurological disorders.

Acute stress alters recognition memory and AMPA/NMDA receptor subunits in a sex-dependent manner.

Several studies have consistently reported a detrimental effect of chronic stress on recognition memory. However, the effects of acute stress on this cognitive ability have been poorly investigated. Moreover, despite well-documented sex differences in recognition memory observed in clinical studies, most of the preclinical studies in this field of research have been carried out by using solely male rodents. Here we tested the hypothesis that acute stress could affect the consolidation of different types of recognition memory in a sex-dependent manner. For this purpose, male and female C57BL6/J mice were exposed to 2-h of restrain stress immediately after the training session of both the novel object recognition (NOR) test and novel object location (NOL) tasks. Acute restraint stress did not affect memory performance of male and female mice, after a 4-h delay between the training session and the test phase of both tasks. By contrast, acute restraint stress altered memory performance in a sex-dependent manner, after a 24-h delay. While stressed mice of both sexes were impaired in the NOL test, only male stressed mice were impaired in the NOR test. Because ionotropic glutamate receptors-mediated neurotransmission is essential for shaping recognition memory, we further tested the hypothesis that post training acute stress could induce sex-dependent transcriptional changes of ionotropic glutamate receptor subunits in the dorsal hippocampus. We uncovered that acute stress induced sex-, time- and type of memory-dependent transcriptional changes of N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits. These findings suggest that the effect of acute stress on recognition memory can be strongly biased by multiple factors including sex. These findings also indicate that the same stress-induced memory impairment observed in both sexes can be triggered by different sex-dependent molecular mechanisms. At the therapeutic level, this should not be overlooked in the context of personalized and targeted treatments.