253 research outputs found
Repeated successful use of eltrombopag in chronic primary immune thrombocytopenia: description of an intriguing case.
Thrombopoietin receptor agonists (TPO-RAs) are used as effective alternative
treatments in ITP patients unresponsive to first-/second-line therapies. TPO-
RAs can also be used to normalize platelet count to safely perform invasive pro-
cedures and chemotherapy, in case of malignancies. In few responsive patients,
TPO-RAs can be suspended maintaining a sustained respons
BAG3 localizes in axonal structures during neuronal differentiation and is expressed in cellular processes of migrating cells in mouse cerebral cortex
BAG3 protein belongs to the family of co-chaperones involved in protein quality control and in the clearance of misfolded proteins [1]. Few studies have addressed BAG3 distribution and function in the central nervous system (CNS) and little is known about the cellular localization of BAG3 during neuronal differentiation in vitro and migration in vivo. Therefore we analysed by immunofluorescence microscopy the cellular distribution of BAG3 in the PC12 cell model treated or not with NGF and in developing and adult cortex of mice brain. Our results shows that BAG3 localizes mainly in vesicle structures of the neuritic domain during cell differentiation, while in undifferentiated cells it appears confined to the cytoplasm near the nuclear membrane. These observations were corroborated by transmission electron microscopy (TEM) which revealed that in NGF-differentiated PC12 cells, BAG3 localizes into electron-dense vesicles clustered along the axon and showing the typical aspect of the large dense core vesicles (LDCVs). Interestingly, the change of BAG3 localization during neuronal differentiation was associated only to a slight increase in the total BAG3 immunoreactivity as shown by western blot analysis. In order to provide further insights on the role of BAG3 in neuronal differentiation and migration, we also analysed BAG3 localization in mice developing and adult cerebral cortex. In mouse developing cortex, BAG3 appeared to be intensely expressed in cellular processes of migrating cells, while in adult brain a low expression was detected in neuronal cell bodies and glial cells. In conclusion, our findings suggest that the presence and differential expression of BAG3 might be required for the correct development of the nervous system as well as for the maintenance of protein homeostasis
The isoprenoid end product N6-Isopentenyladenosine inhibits inflammation in bronchial epithelial cells through modulating the NFκB pathway
N6-Isopentenyladenosine (iPA) is a cytokinin identified in plants but also present in a free form or as a modified nucleoside bound to selenocysteine tRNA in human cells. It is an adenosine modified by an isopentenyl chain which derives from dimethylallil pyrophosphate (DMAPP), an intermediate of the mevalonate pathway. iPA is required for efficient translational decoding of selenoproteins, and can modulate a variety of biological processes including cell cycle progression, DNA synthesis and apoptosis (1). Recently, it has been shown that iPA can exhibit immunomodulatory and anti-inflammatory properties by activating NK cells and modulating cytokine production in a way depending on the concentration used (2). In order to further investigate the anti-inflammatory properties of iPA and its possible mechanisms of action, we analyzed its ability to inhibit TNFα-induced inflammation, either in normal human bronchial epithelial cells or in a model of exacerbated inflammation represented by bronchial cells derived from a Cystic Fibrosis (CF) patient bearing the ΔF508 mutation. Results showed that iPA inhibited IL-8 and RANTES release in both type of cells in a different manner. The analysis of the key enzymes of the STAT3 and NF-κB signalling pathways showed that iPA decreased the phosphorylation of STAT3 enzyme and markedly increased the expression of the direct NF-κB inhibitor, IκBα. These results were corroborated analyzing directly the NF-κB activity in HEK 293/T cells transfected with a NF-κB reporter plasmid. In these cells, iPA was also able to decrease IκBα levels. Of interest, we found that iPA also increased the expression of the antioxidant selenoprotein glutathione peroxidase only in CF cells. Altogether these data suggest that iPA can negatively regulate inflammation with a general mechanism of action involving the inhibition of NF-κB pathway but also propose that, in the presence of an altered inflammatory response such as in CF disease, iPA might act by modulating expression and/or synthesis of glutathione peroxidase
The endocannabinoid anandamide inhibits colon cancer cell growth by modulating different survival and proliferating pathways
The Endocannabinoid System (ECS) comprising the CB1 and CB2 receptors and their endogenous ligands is a central signalling system regulating food intake and energy balance. It is also present in peripheral tissues where it is involved in cell proliferation and survival. It has been shown that in colon cancer cells, the CB1 receptor antagonist SR171416 reduces colon cancer cell growth by acting as an inverse agonist rather than an antagonist [1]. Starting from this observation and from evidence indicating that some biological responses to cannabinoids depend on estrogen levels and some selective estrogen receptor modulators can bind the CB1 receptor [2], we aimed to study the effects of the CB1 receptor ligand anandamide (AEA) on colon cancer cell proliferation and its ability to modulate some survival and proliferating pathways including Akt, MAPK/ERK and estrogen receptor (ER) b signalling which is the predominant ER pathway in colonic epithelium. We used an AEA-analogue and a selective inhibitor of fatty acid amide hydrolase (FAAH) that enhances intracellular levels of AEA and studied proliferation and cell cycle progression on human adenocarcinoma cells DLD1 and SW620. Our results showed that increased levels of AEA significantly reduced cell proliferation in both cell lines at 24 and 48 h also inducing an S phase cell cycle accumulation. The AEA-induced inhibition of cell growth was mediated by a reduced expression of phoshoAkt and phosphoERK and, at the same time, by an induction of ERβ expression. These data suggest that AEA can reduces colon cancer cell proliferation by interfering with different signalling pathways
Differential Expression of Kisspeptin System and Kisspeptin Receptor Trafficking during Spermatozoa Transit in the Epididymis
The hypothalamus–pituitary–testis axis controls the production of spermatozoa, and the kisspeptin system, comprising Kiss1 and Kiss1 receptor (Kiss1R), is the main central gatekeeper. The activity of the kisspeptin system also occurs in testis and spermatozoa, but currently the need of peripheral kisspeptin to produce gametes is not fully understood. Hence, we characterized kisspeptin system in rat spermatozoa and epididymis caput and cauda and analyzed the possible presence of Kiss1 in the epididymal fluid. The presence of Kiss1 and Kiss1R in spermatozoa collected from epididymis caput and cauda was evaluated by Western blot; significant high Kiss1 levels in the caput (p < 0.001 vs. cauda) and constant levels of Kiss1R proteins were observed. Immunofluorescence analysis revealed that the localization of Kiss1R in sperm head shifts from the posterior region in the epididymis caput to perforatorium in the epididymis cauda. In spermatozoa-free epididymis, Western blot revealed higher expression of Kiss1 and Kiss1R in caput (p < 0.05 vs. cauda). Moreover, immunohistochemistry revealed that Kiss1 and Kiss1R proteins were mainly localized in the secretory epithelial cell types and in contractile myoid cells, respectively. Finally, both dot blot and Elisa revealed the presence of Kiss1 in the epididymal fluid collected from epididymis cauda and caput, indicating that rat epididymis and spermatozoa possess a complete kisspeptin system. In conclusion, we reported for the first time in rodents Kiss1R trafficking in spermatozoa during the epididymis transit and Kiss1 measure in the epididymal fluid, thus suggesting a possible role for the system in spermatozoa maturation and storage within the epididymis
Flavonoids and flavonoid-rich natural extracts inhibit cytokine release in cystic fibrosis bronchial epithelial cells by regulating NF-kB pathway
Cystic fibrosis (CF) is a genetic life-shortening condition in Caucasians. Despite being a multi-organ disease, CF is classically diagnosed by symptoms of acute/chronic respiratory disease, with persistent pulmonary infections (Amaral, 2015). CF is caused by mutations in the gene encoding cystic fibrosis transmembrane conductance regulator (CFTR) protein. Inheritance of mutant CFTR alleles results in surface liquid depletion and defective mucociliary clearance leading to pulmonary failure. Defects in CFTR perturb the regulation of many intracellular signaling pathways including the NF-kB pathway causing excessive production of pro-inflammatory mediators. Current CF therapies are directed to delay CF lung damage by restoring CFTR function and controlling abnormal inflammation. However, only few anti-inflammatory drugs are effective for CF treatments (mainly oral corticosteroids and ibuprofen), these drugs have limited beneficial effects in presence of considerable side effects. Flavonoids have been reported as promising anti-inflammatory drugs and some of them seem to act as CFTR direct activators (Amaral, 2015). From this respect, herbal remedies or plant bioactive molecules may be of great interest. To this aim, we tested the anti-inflammatory activity of apolar extracts from the roots of three Peonia species (Paeoniaceae family), namely P. rockii P. ostii and P. lactiflora, on CFTR ΔF508/ΔF508 CuFi1 cells and normal counterpart. The effects of the extracts on intrinsic as well as TNFα-induced inflammation were evaluated by determining IL-8, IL-6 and RANTES production. Further- more, to study the direct effect of the extracts on NF-kB activation, Human Embryonic Kidney cells were used in transient transfection of NF-kB reporter plasmid and NF-kB activity and cytokine productions were also evaluated. Results showed a significant anti-inflammatory activity of all three Peonia extracts with the P. lactiflora being the most effective. Furthermore, we also tested the anti-inflammatory potential of the pure flavonoid naringin in the same model systems. We found that naringin was able to reduce cytokine release through inhibiting the key enzymes of the NF-kB and MAPK/ ERK pathways. Interestingly, preliminary results on spray dried pharmaceutical formulations of this molecule, show that naringin co-sprayed with leucine improves pharmacological activity of the flavonoid neat raw drug
Genotoxicity and cytotoxicity of Aloysia polystachia: an in vivo study in rabbits
In the search of new compounds useful for the treatment of neurological disorders, medicinal plant research has progressed widely in the last decade, particularly because of the hypothesis that natural extracts possess a low or absent toxicity. Aloysia polystachia (Griseb.) Moldenke belonging to the family of Verbenaceae has been used in the traditional medicine for a variety of indications and as a sedative. Recently, some evidence reported that it exhibits some antidepressant- and anxiolytic-like effects involving the modulation of GABA system in preclinical studies in mice (1). However no investigations have been performed on its (geno)toxicity in long-term studies as it would be required for its use in neurological pathologies. In this study, we investigated the genotoxic potential of a water soluble extract of Aloysia polystachia leaves, administered orally every day for 90 days to 20 New Zealand white rabbits homogeneous for weight and age. Subjects were divided into four groups: the control group, and three experimental groups fed with a diet supplemented with 1g/kg; 1.5 g/kg and 2g/kg of Aloysia Polystachia, then peripheral blood was drawn from the vein auricularis marginalis before and after 45 and 90 days of treatment. Cytogenetic analysis was performed on each subject at each time point and chromosome aberrations (structural and numerical) and mitotic index were used as a measure of DNA damage and cytotoxicity (2). Results indicated that Aloysia polystachia extract induces a significant increase in the percentage of aberrant cells as well as in the aberration frequency (mainly chromatid breaks and fragments) associated with a decreasing trend of the mitotic index. The DNA damage was particularly higher after the first 45 days of treatment whereas it remains significantly high but almost unvaried until the end of the treatment. These data suggest that Aloysia polystachia extract has genotoxic and cytotoxic activity, even though further investigations are required to assess which compound of the extract could be responsible for the observed effects
Beta-amyloid-acetylcholine structural interaction: evidence for neuroprotective effects of acetylcholine in neural cells
Alzheimer’s disease (AD) is regarded as a multifactorial disease characterized by a complex pathogenesis including a cholinergic deficit - due to degeneration of cholinergic projections from the basal forebrain - and the extracellular accumulation of amyloid beta (Aβ) peptide. Aβ containing 39 to 42 amino acids is the predominant component of the senile plaques that, together with neurofibrillary tangles, are regarded as the neuropathological hallmarks of AD (Sorrentino et al. 2014). Aβ may assume different conformations changing from random coil or α-helical monomers to β-sheet structures forming toxic oligomers and/or β-sheet mature fibrils. In this framework, we studied the effect of acetylcholine (ACh) on the conformation of Aβ by circular dichroism analysis. Moreover we investigated the ability of ACh to protect neuronal cells from the toxic action of amyloid peptide and to modulate the neuroinflammatory response occurring via the phospholipase A2 (PLA2). Results show that the amount of Aβ(25-35) β-strand raised linearly in absence of ACh, whereas it remained almost constant in presence of ACh. In addition, in a micelle solution mimicking the membrane environment ACh was found effective in increasing and stabilizing the soluble and not toxic helical content of Aβ(25-35) suggesting that ACh is capable to preserve the soluble form of Aβ(25-35), reducing the incipit of Aβ aggregation. In order to assess the neuro-protective ability of ACh against toxic Aβ(25-35) accumulation, we used neural cell (NCC) cultures containing both astrocytes and glial cells prepared from brains embryos from timed pregnant Wistar rats and infused ACh for 48h. By immunostaining, we observed that ACh reduced Aβ(25-35)-induced cell death. Then, we tested the protective effect of ACh on inflammation induced by Aβ administration. NCC were challenged with Aβ(25-35) in the presence and absence of ACh and immunostained for astroglial and neuronal markers: results showed a reduction of the morphological features of astrogliosys in ACh treated cells. PLA2 expression analysis corroborated these data also underlying that ACh can negatively regulate inflammation pathways in glial cells
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