Evidences indicate that tumor development and progression towards a malignant phenotype depend not only on cancer cells themselves, but are also deeply influenced by tumor stroma reactivity. The present study uses mesenchymal stem cells from normal human uterine cervix (hUCESCs), isolated by the minimally invasive method of routine Pap cervical smear, to study their effect on the three main cell types in a tumor: cancer cells, fibroblasts and macrophages. Administration of hUCESCs-conditioned medium (CM) to a highly invasive breast cancer MDA-MB-231 cell line and to human breast tumors with high cell proliferation rates had the effect of reducing cell proliferation, modifying the cell cycle, inducing apoptosis, and decreasing invasion. In a xenograft mouse tumor model, hUCESCs-CM reduced tumor growth and increased overall survival. In cancer-associated fibroblasts, administration of hUCESCs-CM resulted in reduced cell proliferation, greater apoptosis and decreased invasion. In addition, hUCESCs-CM inhibited and reverted macrophage differentiation. The analysis of hUCESCs-CM (fresh and lyophilized) suggests that a complex paracrine signaling network could be implicated in the anti-tumor potential of hUCESCs.In light of their anti-tumor potential, the easy cell isolation method, and the fact that lyophilization of their CM conserves original properties make hUCESCs good candidates for experimental or clinical applications in anticancer therapy.
Animals assess the values of rewards to learn and choose the best possible outcomes. We studied how single neurons in the primate amygdala coded reward magnitude, an important variable determining the value of rewards. A single, Pavlovian-conditioned visual stimulus predicted fruit juice to be delivered with one of three equiprobable volumes (P = 1/3). A population of amygdala neurons showed increased activity after reward delivery, and almost one half of these responses covaried with reward magnitude in a monotonically increasing or decreasing fashion. A subset of the reward responding neurons were tested with two different probability distributions of reward magnitude; the reward responses in almost one half of them adapted to the predicted distribution and thus showed reference-dependent coding. These data suggest parametric reward value coding in the amygdala as a characteristic component of its function in reinforcement learning and economic decision making.
While autophagy is believed to be beneficial for life-span extension, it is controversial which forms or aspects of autophagy are responsible for this effect. We addressed this topic by analyzing the life span of yeast autophagy mutants under caloric restriction, a longevity manipulation. Surprisingly, we discovered that the majority of proteins involved in macroautophagy and several forms of microautophagy were dispensable for life-span extension. The only autophagy protein that is critical for life-span extension was Atg15, a lipase that is located in the endoplasmic reticulum (ER) and transported to vacuoles for disintegrating membranes of autophagic bodies. We further found that vacuole-vacuole fusion was required for life-span extension, which was indicated by the shortened life span of mutants missing proteins (ypt7Delta, nyv1Delta, vac8Delta) or lipids (erg6Delta) involved in fusion. Since a known function of vacuole-vacuole fusion is the maintenance of the vacuole membrane integrity, we analyzed aged vacuoles and discovered that aged cells had altered vacuolar morphology and accumulated autophagic bodies, suggesting that certain forms of autophagy do contribute to longevity. Like aged cells, erg6Delta accumulated autophagic bodies, which is likely caused by a defect in lipase instead of proteases due to the existence of multiple vacuolar proteases. Since macroautophagy is not blocked by erg6Delta, we propose that a new form of autophagy transports Atg15 via the fusion of vacuoles with vesicles derived from ER, and we designate this putative form of autophagy as secretophagy. Pending future biochemical studies, the concept of secretophagy may provide a mechanism for autophagy in life-span extension.
Treatment with CM-hUCESCs improved wound healing of alkali-injured corneas and showed a strong bactericidal effect on CLs. Patients using CLs and suffering from dry eye, allergies induced by commercial solutions, or small corneal injuries could benefit from this treatment.
Prediction about outcomes constitutes a basic mechanism underlying informed economic decision making. A stimulus constitutes a reward predictor when it provides more information about the reward than the environmental background. Reward prediction can be manipulated in two ways, by varying the reward paired with the stimulus, as done traditionally in neurophysiological studies, and by varying the background reward while holding stimulus-reward pairing constant. Neuronal mechanisms involved in reward prediction should also be sensitive to changes in background reward independently of stimulus-reward pairing. We tested this assumption on a major brain structure involved in reward processing, the central and basolateral amygdala. In a 2 × 2 design, we examined the influence of rewarded and unrewarded backgrounds on neuronal responses to rewarded and unrewarded visual stimuli. Indeed, responses to the unchanged rewarded stimulus depended crucially on background reward in a population of amygdala neurons. Elevating background reward to the level of the rewarded stimulus extinguished these responses, and lowering background reward again reinstated the responses without changes in stimulus-reward pairing. None of these neurons responded specifically to an inhibitory stimulus predicting less reward compared with background (negative contingency). A smaller group of amygdala neurons maintained stimulus responses irrespective of background reward, possibly reflecting stimulus-reward pairing or visual sensory processes without reward prediction. Thus in being sensitive to background reward, the responses of a population of amygdala neurons to phasic stimuli appeared to follow the full criteria for excitatory reward prediction (positive contingency) rather than reflecting simple stimulus-reward pairing (contiguity).
Dopamine projections that extend from the ventral tegmental area to the striatum have been implicated in the biological basis for behaviors associated with reward and addiction. Until recently, it has been difficult to evaluate the complex balance of energy utilization and neural activity in the striatum. Many techniques such as electrophysiology, functional magnetic resonance imaging (fMRI), and fast-scan cyclic voltammetry have been employed to monitor these neurochemical and neurophysiological changes. In this brain region, physiological responses to cues and rewards cause local, transient pH changes. Oxygen and pH are coupled in the brain through a complex system of blood flow and metabolism as a result of transient neural activity. Indeed, this balance is at the heart of imaging studies such as fMRI. To this end, we measured pH and O 2 changes with fast-scan cyclic voltammetry in the striatum as indices of changes in metabolism and blood flow in vivo in three Macaca mulatta monkeys during reward-based behaviors. Specifically, the animals were presented with Pavlovian conditioned cues that predicted different probabilities of liquid reward. They also received free reward without predictive cues. The primary detected change consisted of pH shifts in the striatal extracellular environment following the reward predicting cues or the free reward. We observed three types of cue responses that consisted of purely basic pH shifts, basic pH shifts followed by acidic pH shifts, and purely acidic pH shifts. These responses increased with reward probability, but were not significantly different from each other. The pH changes were accompanied by increases in extracellular O 2 . The changes in pH and extracellular O 2 are consistent with current theories of metabolism and blood flow. However, they were of sufficient magnitude that they masked dopamine changes in the majority of cases. The findings suggest a role of these chemical responses in neuronal reward processing.
Food branding is ubiquitous, however, not all children are equally susceptible to its effects. The objectives of this study were to 1) determine whether food brands evoke differential response than non-food brands in brain areas related to motivation and inhibitory control using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) and 2) determine the association between brain response and energy intake at test-meals presented with or without brands. Twenty-eight 7-10 year-old children completed four visits as part of a within-subjects design where they consumed three multi-item test-meals presented with familiar food brands, novel food brand, and no brand. On the fourth visit an fMRI was performed where children passively viewed food brands, non-food brands and control images. A whole-brain analysis was conducted to compare BOLD response between conditions. Pearson's correlations were calculated to determine the association between brain response and meal intake. Relative to non-food brands, food brand images were associated with increased activity in the right lingual gyrus. Relative to control, food and non-food brand images were associated with greater response in bilateral fusiform gyri and decreased response in the cuneus, precuneus, lingual gyrus, and supramarginal gyrus. Less activation in the bilateral fusiform gyrus to both food and non-food brands was associated with greater energy intake of the branded vs unbranded meal. These findings may help explain differences in the susceptibility to the intake-promoting effects of food advertising in children.
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