Cancer exosomes in urine: A promising biomarker source

In face of innovative therapeutic strategies for cancer diagnosis and treatment, and of the elusiveness of renal and urinary tract tumors, the identification of novel biomarkers for diagnosis, prognosis, selection and monitoring of therapies is a primary target of research. The concept of "precision medicine" for tailoring the oncologic management in a minimally invasive fashion is considered a new epoch in cancer management. Extracellular vesicles, and exosomes in particular, carry lipids, mRNAs, non-coding RNAs, DNA, and active proteins, are present in a variety of bodily fluids including urine. In fact, urinary exosomes contain most of the urinoma proteins. Exosomes are nanovesicles originating from an endocytic pathway of the endocellular membranes and upon release are actors of intercellular communication, able to induce phenotypic changes including tumorigenesis and metastasis, in recipient cells. Tumor-derived exosomes play critical roles in all stages of tumor development and metastasis of almost all cancer types. Exosomal proteins may serve as biomarkers for clinical applications, still to be validated. Please reword the next sentence. Not clear. Exosomes extracellular gather in urine, thus becoming a great resource for recovery of biomarkers and a promising non-invasive diagnostic instrument for renal disease. Liquid biopsies (body fluids) may be preferable to tumor tissue biopsies since they are less invasive. Urinary exosomes in particular are available in great quantity in a noninvasive way and are representative of each of the cells of the urinary tract. In the present review, we summarize our knowledge of the urine exosomes with a new vision as liquid biopsy and high-throughput techniques. The emerging metabolic signature of urinary exosomes is also discussed in terms of its potential clinical application

Exosomes as "translational" cancer promoter organelles

The term Exosome has come into use to define nanovesicles contained in multivesicular endosomes (MVE), secreted by fusion of MVE with the plasma membrane. Exosomes are secreted in vivo by almost any cell type and can be isolated from body fluids. Indeed, circulating vesicles account for both exosomes and microvesicles (MVs), which can be purified by various purification methods and fully discriminated according to their shape, size and CD markers. Due to their protein and RNA content,once internalized, exosomes have the potential to act as \u201ctranslational\u201d organelles, altering the expression pattern of recipient cells, their growth, and fate. In fact, exosomes are involved in many of physio-pathological processes, thereby including cancer

Beneficial Effect of Antioxidants in Retinopathies: A New Hypothesis

The retina is the most oxygen consuming tissue of the body. Rod and cone photoreceptors efficiently carry out visual cascades, which are energetically costly processes. Data has recently been published that suggests that the metabolic support to phototransduction in the rod outer segment (OS) may originate directly in the OS, which is able to conduct aerobic metabolism. This oxygen-handling activity of the rod OS, which was never suspected before, appears to be a primary cause of the generation of reactive oxygen species directly inside the OS. Oxidative stress has been hypothesised to contribute to most of the neurodegenerative retinal pathologies, such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa and photoreceptor cell death after retinal detachment. Many natural antioxidant compounds are routinely used in experimental or human therapies for preventing or delaying photoreceptor degeneration in those pathologies. Here it is proposed that the ultimate reason for the beneficial actions of antioxidants in preventing or retarding the effect on the retinal degenerative pathologies can be found in their action on reactive oxygen species generated by the ectopic mitochondrial electron transport chain (ETC) coupled to FoF1-ATP synthase in rod OS disks. In fact, if not adequately coupled, the ETC generates reactive oxygen species that, in turn, can act on the polyunsaturated fatty acids which the rod OS is rich in. If correct, the mechanism put forward here would provide a potential for the molecular basis of therapies with antioxidants for retinal degenerative diseases

Localization of the cyclic ADP-ribose-dependent calcium signaling pathway in bovine rod outer segments.

PURPOSE Calcium ions play a pivotal role in phototransduction. In this study, the presence and functional role of the adenosine diphosphoribosyl (ADPR)-cyclase-cyclic ADP-ribose (cADPR) system in bovine retinal rod outer segments (ROS) was investigated. METHODS A Ca(2+) release from osmotically intact ROS discs elicited by cADPR was studied in the presence of the Ca(2+) tracer fluo-3. Endogenous cyclic guanosine diphosphate ribose (cGDPR) formation in discs was investigated by spectrophotometric detection of its synthesis from nicotinamide guanine dinucleotide (NGD(+)). ADPR-cyclase was also investigated at a structural level on mildly denaturing SDS-PAGE by production of cyclic inosine diphosphate ribose from nicotinamide hypoxantine dinucleotide (NHD(+)). Western immunoblot analysis with a specific antibody was conducted to verify the presence of ryanodine-sensitive Ca(2+) channels (RyRs) in ROS discs. RESULTS cADPR-dependent Ca(2+) release was a linear function of extravesicular free Ca(2+) concentration, between 200 and 900 nM Ca(2+). When free Ca(2+) was 203 +/- 10 nM the mean Ca(2+) release was 23 +/- 3 pmol/mL per milligram protein. The average rate of cGDPR production was 13 +/- 2 nmol cGDPR/min per milligram protein, by a putative enzyme with an apparent molecular mass of 53 +/- 1 kDa. ROS ADPR-cyclase was localized in the membranous fraction. No nicotinamide adenine dinucleotide glycohydrolase (NADase) activity was detected. The presence of RyR channels in pure disc preparations was confirmed by confocal laser scanning microscopy. CONCLUSIONS A cADPR metabolism may be present in retinal ROS discs, which may be Ca(2+) stores operated by cADPR. A model is proposed for the physiological role of cADPR-mediated Ca(2+) release in bovine ROS

Altered glucose catabolism in the presynaptic and perisynaptic compartments of SOD1G93A mouse spinal cord and motor cortex indicates that mitochondria are the site of bioenergetic imbalance in ALS

Amyotrophic lateral sclerosis is an adult-onset neurodegenerative disease that develops due to motor neuron death. Several mechanisms occur supporting neurodegeneration, including mitochondrial dysfunction. Recently, we demonstrated that the synaptosomes from the spinal cord of SOD1G93A mice, an in vitro model of presynapses, displayed impaired mitochondrial metabolism at early pre-symptomatic stages of the disease, while perisynaptic astrocyte particles, or gliosomes, were characterized by mild energy impairment only at symptomatic stages. This work aimed to understand whether mitochondrial impairment is a consequence of upstream metabolic damage. We analysed the critical pathways involved in glucose catabolism at presynaptic and perisynaptic compartments. Spinal cord and motor cortex synaptosomes from SOD1G93A mice displayed high activity of hexokinase and phosphofructokinase, key glycolysis enzymes, and of citrate synthase and malate dehydrogenase, key Krebs cycle enzymes, but did not display high lactate dehydrogenase activity, the key enzyme in lactate fermentation. This enhancement was evident in the spinal cord from the early stages of the disease and in the motor cortex at only symptomatic stages. Conversely, an increase in glycolysis and lactate fermentation activity, but not Krebs cycle activity, was observed in gliosomes from the spinal cord and motor cortex of SOD1G93A mice although only at the symptomatic stages of the disease. The cited enzymatic activities were enhanced in spinal cord and motor cortex homogenates, paralleling the time-course of the effect observed in synaptosomes and gliosomes. The observed metabolic modifications might be considered an attempt to restore altered energetic balance and indicate that mitochondria represent the ultimate site of bioenergetic impairment. This article is protected by copyright. All rights reserved

The novel diterpene 7\u3b2-acetoxy-20-hydroxy-19,20-epoxyroyleanone from Salvia corrugata shows complex cytotoxic activities against human breast epithelial cells

Aims The aim of this study was the characterization of the in vitro cytotoxic properties of a recently isolated diterpene compound, 7\u3b2-acetoxy-20-hydroxy-19,20-epoxyroyleanone (compound 1), extracted from Salvia corrugata, versus human cell lines. Main Methods We used as model study immortalized breast epithelial cells MCF10A and two ERBB2+ breast cancer (BCa) cell lines, SKBR-3 and BT474. Compound 1 was isolated by methanolic extraction from regenerated shoots of Salvia corrugata Vahl, and purified by high pressure liquid chromatography (HPLC). Flow cytometry (FCM) was employed for cell cycle, apoptosis and reactive oxygen species (ROS) analysis. Cell morphology was assessed by immunofluorescence and transmission electron microscopy (TEM). Key Findings Compound 1 inhibited cell survival of all breast cell lines. In particular, compound 1 promoted cell cycle arrest in the G0/G1 phase and apoptosis along with impairment of the mitochondrial function, which was reflected in a gross alteration of the mitochondrial network structure. Furthermore, we also detected a potent activation of the ERK1/2 kinase, which suggested the induction of reactive oxygen species (ROS). Partial rescue of survival obtained with n-acetylcysteine (NAC) when coadminstered with compound 1 further supported a contribution of ROS mediated mechanisms to the growth-arrest and proapoptotic activity of compound 1 in both BCa cell lines. ROS production was indeed confirmed in SKBR-3. Significance Our findings show that compound 1 has a cytotoxic activity against both human normal and cancer cell lines derived from breast epithelia, which is mediated by ROS generation and mitochondrial damage

Modulation of the rod outer segment aerobic metabolism diminishes the production of radicals due to light absorption

Oxidative stress is a primary risk factor for both inflammatory and degenerative retinopathies. Our previous data on blue light-irradiated retinas demonstrated an oxidative stress higher in the rod outer segment (OS) than in the inner limb, leading to impairment of the rod OS extra-mitochondrial aerobic metabolism. Here the oxidative metabolism and Reactive Oxygen Intermediates (ROI) production was evaluated in purified bovine rod OS in function of exposure to different illumination conditions. A dose response was observed to varying light intensities and duration in terms of both ROI production and ATP synthesis. Pretreatment with resveratrol, inhibitor of F1Fo-ATP synthase, or metformin, inhibitor of the respiratory complex I, significantly diminished the ROI production. Metformin also diminished the rod OS Complex I activity and reduced the maximal OS response to light in ATP production. Data show for the first time the relationship existing in the rod OS between its -aerobic- metabolism, light absorption, and ROI production. A beneficial effect was exerted by metformin and resveratrol, in modulating the ROI production in the illuminated rod OS, suggestive of their beneficial action also in vivo. Data shed new light on preventative interventions for cone loss secondary to rod damage due to oxidative stress

Inhibition of Hemorragic Snake Venom Components: Old and New Approaches

Snake venoms are complex toxin mixtures. Viperidae and Crotalidae venoms, which are hemotoxic, are responsible for most of the envenomations around the world. Administration of antivenins aimed at the neutralization of toxins in humans is prone to potential risks. Neutralization of snake venom toxins has been achieved through different approaches: plant extracts have been utilized in etnomedicine. Direct electric current from low voltage showed neutralizing properties against venom phospholipase A2 and metalloproteases. This mini-review summarizes new achievements in venom key component inhibition. A deeper knowledge of alternative ways to inhibit venom toxins may provide supplemental treatments to serum therapy

Polyphenols in Anti-cancer Therapy and Prevention: Should we Add the FoF1-ATP Synthase Inhibition?

Si tratta di una "Perspective", pertanto non è previsto un Abstract, sulla rilevanza della azione di modulazione della F1Fo-ATP sintasi da parte dei polifenoli, nella loro nota attività anti-cancro