Update on the recent development of allosteric modulators for adenosine receptors and their therapeutic applications

Adenosine receptors (ARs) have been identified as promising therapeutic targets for countless pathological conditions, spanning from inflammatory diseases to central nervous system disorders, from cancer to metabolic diseases, from cardiovascular pathologies to respiratory diseases, and beyond. This extraordinary therapeutic potential is mainly due to the plurality of pathophysiological actions of adenosine and the ubiquitous expression of its receptors. This is, however, a double-edged sword that makes the clinical development of effective ligands with tolerable side effects difficult. Evidence of this is the low number of AR agonists or antagonists that have reached the market. An alternative approach is to target allosteric sites via allosteric modulators, compounds endowed with several advantages over orthosteric ligands. In addition to the typical advantages of allosteric modulators, those acting on ARs could benefit from the fact that adenosine levels are elevated in pathological tissues, thus potentially having negligible effects on normal tissues where adenosine levels are maintained low. Several A(1) and various A(3)AR allosteric modulators have been identified so far, and some of them have been validated in different preclinical settings, achieving promising results. Less fruitful, instead, has been the discovery of A(2A) and A(2B)AR allosteric modulators, although the results obtained up to now are encouraging. Collectively, data in the literature suggests that allosteric modulators of ARs could represent valuable pharmacological tools, potentially able to overcome the limitations of orthosteric ligands

Effects of feeding raw or extruded linseed on the ruminal ecosystem of sheep

Polyunsaturated fatty acids affect bacterial and protozoal population, inducing important modifications in rumen metabolism. The aim of this study was to investigate the effect of linseed extrusion on in situ ruminal degradability and microbial number and distribution. Six ruminally fistulated sheep were divided in 3 groups and fed one of the following diets according to a replicated Latin square design: (a) control, based on mixed hay and maize grains; (b) as in (a) plus 130 g of grounded raw linseed; (c) as in (b) except that the linseed was extruded. Extrusion decreased linseed dry matter and fat degradabilities. There was a marked reduction of total protozoal population in sheep fed supplemented diets. No effects were observed between groups on bacterial concentration, hay dry matter and NDF in situ degradabilities

A palmitoylethanolamide producing lactobacillus paracasei improves clostridium difficile toxin a-induced colitis

Genetically engineered probiotics, able to in situ deliver therapeutically active compounds while restoring gut eubiosis, could represent an attractive therapeutic alternative in Clostridium difficile infection (CDI). Palmitoylethanolamide is an endogenous lipid able to exert immunomodulatory activities and restore epithelial barrier integrity in human models of colitis, by binding the peroxisome proliferator–activated receptor-α (PPARα). The aim of this study was to explore the efficacy of a newly designed PEA-producing probiotic (pNAPE-LP) in a mice model of C. difficile toxin A (TcdA)-induced colitis. The human N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD), a key enzyme involved in the synthesis of PEA, was cloned and expressed in a Lactobacillus paracasei that was intragastrically administered to mice 7 days prior the induction of the colitis. Bacteria carrying the empty vector served as negative controls (pLP).In the presence of palmitate, pNAPE-LP was able to significantly increase PEA production by 27,900%, in a time- and concentration-dependent fashion. Mice treated with pNAPE-LP showed a significant improvement of colitis in terms of histological damage score, macrophage count, and myeloperoxidase levels (−53, −82, and −70.4%, respectively). This was paralleled by a significant decrease both in the expression of toll-like receptor-4 (−71%), phospho-p38 mitogen-activated protein kinase (−72%), hypoxia-inducible factor-1-alpha (−53%), p50 (−74%), and p65 (−60%) and in the plasmatic levels of interleukin-6 (−86%), nitric oxide (−59%), and vascular endothelial growth factor (−71%). Finally, tight junction protein expression was significantly improved by pNAPE-LP treatment as witnessed by the rescue of zonula occludens-1 (+304%), Ras homolog family member A-GTP (+649%), and occludin expression (+160%). These protective effects were mediated by the specific release of PEA by the engineered probiotic as they were abolished in PPARα knockout mice and in wild-type mice treated with pLP. Herein, we demonstrated that pNAPE-LP has therapeutic potential in CDI by inhibiting colonic inflammation and restoring tight junction protein expression in mice, paving the way to next generation probiotics as a promising strategy in CDI prevention

Prognostic value of circulating tumor cells in nonmuscle invasive bladder cancer: a CellSearch analysis

Background: Circulating tumor cells (CTCs) provide prognostic information in patients with metastatic tumors. Recent studies have shown that CTCs are released in circulation in an early phase of cancer disease so that their presence is under investigation in the adjuvant setting. Few studies investigated the prognostic significance of CTCs enumeration in patients with metastatic and advanced bladder cancer. The current study has analyzed the presence of CTC in patients with nonmuscle-invasive bladder cancer (NMIBC). Patients and methods: Forty-four NMIBC patients were enrolled and included in a 24-month follow-up program. Blood drawings were carried out in all patients at the first diagnosis. CellSearch system (Veridex; LLC, Raritan, NJ) was used for CTCs enumeration. Results: CTC were detectable in 8/44 patients (18%). Presence of CTC was found significantly associated to shorter time to first recurrence (6.5 versus 21.7 months, P < 0.001). Median time to progression was not reached, due to the short follow-up period. CTC presence was found associated to concomitant carcinoma in situ and higher T category. Conclusion: The detection of CTC in this setting of disease may allow to distinguish patients with high risk of recurrence from those with high risk of progression, as well as to early identify patients candidate for adjuvant treatment

High-fat diet impairs duodenal barrier function and elicits glia-dependent changes along the gut-brain axis that are required for anxiogenic and depressive-like behaviors

Background: Mood and metabolic disorders are interrelated and may share common pathological processes. Autonomic neurons link the brain with the gastrointestinal tract and constitute a likely pathway for peripheral metabolic challenges to affect behaviors controlled by the brain. The activities of neurons along these pathways are regulated by glia, which exhibit phenotypic shifts in response to changes in their microenvironment. How glial changes might contribute to the behavioral effects of consuming a high-fat diet (HFD) is uncertain. Here, we tested the hypothesis that anxiogenic and depressive-like behaviors driven by consuming a HFD involve compromised duodenal barrier integrity and subsequent phenotypic changes to glia and neurons along the gut-brain axis. Methods: C57Bl/6 male mice were exposed to a standard diet or HFD for 20 weeks. Bodyweight was monitored weekly and correlated with mucosa histological damage and duodenal expression of tight junction proteins ZO-1 and occludin at 0, 6, and 20 weeks. The expression of GFAP, TLR-4, BDNF, and DCX were investigated in duodenal myenteric plexus, nodose ganglia, and dentate gyrus of the hippocampus at the same time points. Dendritic spine number was measured in cultured neurons isolated from duodenal myenteric plexuses and hippocampi at weeks 0, 6, and 20. Depressive and anxiety behaviors were also assessed by tail suspension, forced swimming, and open field tests. Results: HFD mice exhibited duodenal mucosa damage with marked infiltration of immune cells and decreased expression of ZO-1 and occludin that coincided with increasing body weight. Glial expression of GFAP and TLR4 increased in parallel in the duodenal myenteric plexuses, nodose ganglia, and hippocampus in a time-dependent manner. Glial changes were associated with a progressive decrease in BDNF, and DCX expression, fewer neuronal dendritic spines, and anxiogenic/depressive symptoms in HFD-treated mice. Fluorocitrate (FC), a glial metabolic poison, abolished these effects both in the enteric and central nervous systems and prevented behavioral alterations at week 20. Conclusions: HFD impairs duodenal barrier integrity and produces behavioral changes consistent with depressive and anxiety phenotypes. HFD-driven changes in both peripheral and central nervous systems are glial-dependent, suggesting a potential glial role in the alteration of the gut-brain signaling that occurs during metabolic disorders and psychiatric co-morbidity

Neural correlates of anosognosia in Alzheimer\u2019s disease and mild cognitive impairment: A multi-method assessment

Patients with Alzheimer\u2019s Disease (AD) and Mild Cognitive Impairment (MCI) may present anosognosia for their cognitive deficits. Three different methods have been usually used to measure anosognosia in patients with AD and MCI, but no studies have established if they share similar neuroanatomical correlates. The purpose of this study was to investigate if anosognosia scores obtained with the three most commonly used methods to assess anosognosia relate to focal atrophy in AD and MCI patients, in order to improve understanding of the neural basis of anosognosia in dementia. Anosognosia was evaluated in 27 patients (15 MCI and 12 AD) through clinical rating (Clinical Insight Rating Scale, CIRS), patient-informant discrepancy (Anosognosia Questionnaire Dementia, AQ-D), and performance discrepancy on different cognitive domains (self-appraisal discrepancies, SADs). Voxel-based morphometry correlational analyses were performed on magnetic resonance imaging (MRI) data with each anosognosia score. Increasing anosognosia on any anosognosia measurement (CIRS, AQ-D, SADs) was associated with increasing gray matter atrophy in the medial temporal lobe including the right hippocampus. Our results support a unitary mechanism of anosognosia in AD and MCI, in which medial temporal lobes play a key role, irrespectively of the assessment method used. This is in accordance with models suggesting that anosognosia in AD is primarily caused by a decline in mnemonic processes

Clinical impact of first-line bevacizumab plus chemotherapy in metastatic colorectal cancer of mucinous histology: a multicenter, retrospective analysis on 685 patients

In metastatic colorectal cancer (MCRC), mucinous histology has been associated with poor response rate and prognosis. We investigated whether bevacizumab combined with different chemotherapy regimens may have an impact on clinical outcomes of MCRC patients with mucinous histology

Prognostic significance of KRAS mutation rate in metastatic colorectal cancer patients.

No abstract availabl

Familial adenomatosis polyposis–related desmoid tumours treated with low-dose chemotherapy: results from an international, multi-institutional, retrospective analysis

[Introduction] Desmoid tumour (DT) is a locally aggressive fibroblastic proliferative disease representing the most common extraintestinal manifestation of familial adenomatosis polyposis (FAP). As data on the activity of chemotherapy in these patients are limited, we examined the outcomes of patients treated with low-dose methotrexate (MTX)+vinca alkaloids (vinorelbine or vinblastine).[Patients and methods] We retrospectively reviewed clinical and outcome data from all patients with confirmed FAP-associated DTs treated with weekly MTX+vinca alkaloids in seven European sarcoma reference centres between January 2000 and December 2018. Radiological responses were assessed using RECIST V.1.0 and V.1.1. The Kaplan-Meier method associated to the log-rank test was used to estimate and compare survival curves.[Results] We identified 37 patients (median age 29 years, range 7–44). According to RECIST, 20/37 (54.1%) patients achieved partial response (PR), 15/37 (40.5%) patients had stable disease and 2/37 (5.4%) had progressive disease as best response. Overall, the median progression-free survival (PFS) was 6.5 years (range, 0.3–12.1 years). In the subset of patients achieving PR as best response, the median PFS was not reached. In a subset of 11 patients with progressive disease offered MTX+vinca alkaloids rechallenge (after chemotherapy withdrawal following prolonged disease control), the disease control rate was 100%, resulting in a median PFS after rechallenge of 5.8 years.[Conclusions] This is the largest series on the activity of low-dose chemotherapy in patients with FAP-related DT. In this population, MTX+vinca alkaloids is an active combination, as already reported in patients with sporadic DT