Stress-induced neurogenic inflammation in murine skin skews dendritic cells towards maturation and migration: key role of intercellular adhesion molecule-1/leukocyte function-associated antigen interactions.

The skin continuously serves as a biosensor of multiple exogenous stressors and integrates the resulting responses with an individual's central and peripheral endogenous response systems to perceived stress; it also acts to protect against external challenges such as wounding and infection. We have previously shown in mice that stress induces nerve growth factor- and substance P-dependent neurogenic inflammation, which includes the prominent clustering of MHC class II(+) cells. Because the contribution of dendritic cells (DCs) in response to stress is not well understood, we examined the role of DCs in neurogenic inflammation in murine skin using a well-established murine stress model. We show that sound stress increases the number of intradermal langerin(+) and CD11c(+) DCs and induces DC maturation, as indicated by the up-regulated expression of CD11c, MHC class II, and intercellular adhesion molecule-1 (ICAM-1). Blocking of ICAM-1/leukocyte function-associated antigen-1 interactions significantly abrogated the stress-induced numeric increase, maturation, and migration of dermal DCs in vivo and also reduced stress-induced keratinocyte apoptosis and endothelial cell expression of ICAM-1. In conclusion, stress exposure causes a state of immune alertness in the skin. Such adaptation processes may ensure protection from possible infections on wounding by stressors, such as attack by predators. However, present-day stressors have changed and such adaptations appear redundant and may overrun skin homeostasis by inducing immune dermatoses.

Enhanced integrated stress response promotes myelinating oligodendrocyte survival in response to interferon-gamma.

The T-cell-derived, pleiotropic cytokine interferon (IFN)-gamma is believed to play a key regulatory role in immune-mediated demyelinating disorders of the central nervous system, including multiple sclerosis and experimental autoimmune encephalomyelitis. Our previous work has demonstrated that the endoplasmic reticulum (ER) stress response modulates the response of oligodendrocytes to this cytokine. The ER stress response activates the pancreatic ER kinase, which coordinates an adaptive program known as the integrated stress response by phosphorylating translation initiation factor 2alpha (eIF2alpha). In this study, we found that growth arrest and DNA damage 34 (GADD34), a stress-inducible regulatory subunit of a phosphatase complex that dephosphorylates eIF2alpha, was selectively up-regulated in myelinating oligodendrocytes in mice that ectopically expressed IFN-gamma in the central nervous system. We also found that a GADD34 mutant strain of mice displayed increased levels of phosphorylated eIF2alpha (p-eIF2alpha) in myelinating oligodendrocytes when exposure to IFN-gamma, as well as diminished oligodendrocyte loss and hypomyelination. Furthermore, treatment with salubrinal, a small chemical compound that specifically inhibits protein phosphatase 1(PP1)-GADD34 phosphatase activity, increased the levels of p-eIF2alpha and ameliorated hypomyelination and oligodendrocyte loss in cultured hippocampal slices exposed to IFN-gamma. Thus, our data provide evidence that an enhanced integrated stress response could promote oligodendrocyte survival in immune-mediated demyelination diseases.

[Influence of prenatal stress on free radical oxidation lipids, both proteins and activity of superoxiddismutase in neurones and glial cells of the rat brain cortex].

Processes of free radical oxidation of protein, lipids, and activity of superoxiddismutase in neurons and glial cells of the rat brain cortex in ontogenesis and after prenatal stress. Irrespective of age, the level of free radical oxidation of lipids and proteins in neurons is higher in comparison with the glia. The same was found in the study of superoxiddismutase activity. After prenatal stress, the level of free radical oxidation of lipids is reduced both in neurons, and in the glia. On the contrary, the contents of oxidation of proteins rises in neurons on the average fourfold. Activity of superoxiddismutase in animals who had suffered from prenatal stress is considerably reduced in neurons remaining unchanged in glial cells.

Circulating progenitor cells after cold pressor test in hypertensive and uremic patients.

Endothelium was initially considered an inert lining of the blood vessels. Recently, it was suggested that damaged cells are continuously replaced by novel cells, hematopoietic stem cells (HSCs), which are directly mobilized by the bone marrow and then transformed into endothelial progenitor cells (EPCs). Initial triggers of vessel remodeling are physical forces such as blood pressure and fluid shear stress. We investigated whether or not a stress stimulus on vessels applied by a cold pressor test (CPT) would stimulate the mobilization of progenitor cells. Twenty-two healthy subjects, 20 patients with essential hypertension, and 18 with chronic kidney disease (CKD) underwent CPT by dipping their hands in icy water for 4 min. Immediately before and after 4 and 60 min, we quantified HSCs and EPCs identified by flow cytometry. We measured also adhesion soluble molecules (sICAM-1, sVCAM-1, and sE-selectin) as markers of endothelial activation. In healthy and hypertensive subjects, but not in CKD subjects, the number of HSCs was elevated as a direct response to CPT stress. Levels of EPCs and adhesion soluble molecules increased significantly, but to a different extent in every group. In CKD patients, the number of EPCs did not return to basal levels either after 60 min. Levels of adhesion soluble molecules directly correlated with the number of progenitor cells in hypertensive and healthy subjects. CPT caused an increase in adhesion soluble molecules. Discrepancies in the numbers of HSCs and EPCs in CKD patients could suggest a specific impairment in blood vessel remodeling correlated with recognized endothelial dysfunction.

Fatty acid analyses may provide insight into the progression of starvation among squamate reptiles.

Fasting-induced changes in fatty acid composition have been reported to occur within the body lipids of several types of animals; however, little is known about the changes in fatty acid profiles exhibited by reptiles subjected to prolonged fasting. This study characterizes the fatty acid profiles of six reptile species subjected to sublethal periods of fasting lasting 0, 56, 112, and 168 days. Analyses of fatty acid methyl esters (FAMEs) conducted on the total body lipids of rattlesnakes (Crotalus atrox), ratsnakes (Elaphe obsoleta), pythons (Python regius), boas (Boa constrictor), true vipers (Bitis gabonica), and monitor lizards (Varanus exanthematicus) revealed that all of the species exhibited similar characteristic changes in their fatty acid profiles during starvation stress. According to ANOVAs, the four most effective indicators of the onset of starvation were significant increases in the [1] fatty acid unsaturation index as well as ratios of [2] linoleic to palmitoleic acid, [3] oleic to palmitic, and [4] arachidonic to total fatty acid concentrations. The results of this study suggest that FAME analyses might be useful for identifying nutritional stress and/or starvation among squamate reptiles; however, forthcoming studies will be required to validate the generality of these responses. I also review the potential limitations of this approach, and suggest experiments that will be important for future applications of FAME analyses. Ultimately, it is hoped that FAME analyses can be used in conjunction with current practices as an additional tool to characterize the prevalence of starvation experienced by free-living reptiles.

Decreased glucose tolerance but normal blood glucose levels in the field in the caviomorph rodent Ctenomys talarum: the role of stress and physical activity.

Hystricomorph rodents have a divergent insulin molecule with only 1-10% of the biological activity in comparison to other mammalian species. In this study, we used the subterranean rodent Ctenomys talarum as a model and performed blood glucose tolerance tests (GTTs) with trained and untrained individuals to evaluate blood glucose regulation and the possible role of physical activity as a compensatory mechanism. Additionally, we evaluated the variations in blood glucose during acute and chronic stress and gathered data in the field to evaluate natural-occurring variations in blood glucose levels. The GTTs showed that C. talarum have a diminished capacity of regulating blood glucose levels in comparison to other mammals and suggest that unexplored differences in the compensatory mechanisms, insulin structure and/or glucose transporters exist within species of hystricomorph rodents. However, blood glucose levels in the field stayed within the normal mammalian range. Physical activity did not prove to be a compensatory mechanism for blood glucose regulation. The individuals did not display important increases in blood glucose after acute stressors and managed to adequately regulate blood glucose during chronic stress. We suggest that the species may not face a selective pressure favoring a more tightly, mammalian like, capacity of regulating blood glucose levels.

A role for brain stress systems in addiction.

Drug addiction is a chronically relapsing disorder characterized by compulsion to seek and take drugs and has been linked to dysregulation of brain regions that mediate reward and stress. Activation of brain stress systems is hypothesized to be key to the negative emotional state produced by dependence that drives drug seeking through negative reinforcement mechanisms. This review explores the role of brain stress systems (corticotropin-releasing factor, norepinephrine, orexin [hypocretin], vasopressin, dynorphin) and brain antistress systems (neuropeptide Y, nociceptin [orphanin FQ]) in drug dependence, with emphasis on the neuropharmacological function of extrahypothalamic systems in the extended amygdala. The brain stress and antistress systems may play a key role in the transition to and maintenance of drug dependence once initiated. Understanding the role of brain stress and antistress systems in addiction provides novel targets for treatment and prevention of addiction and insights into the organization and function of basic brain emotional circuitry.

Tumor-microenvironment interactions: dangerous liaisons.

The interaction between microenvironmental components and tumor cells is bidirectional. Tumor cells and their products are capable of regulating and altering gene expression in nontumor cells residing in or infiltrating into the microenvironment and exert selective pressures on such cells, thereby shaping their phenotype. Conversely, microenvironmental components regulate gene expression in tumor cells thereby directing the tumor into one or several possible molecular evolution pathways, some of which may lead to metastasis. This review summarizes six instances in which the tumor liaises with different components of its microenvironment. These liaisons result, in most cases, in enhanced tumor progression. In these cases (responses of tumor and nontumor cells to microenvironmental stress, the interaction of the tumor with fibroblasts, endothelial cells and macrophages, the formation of the metastatic niche, and the interaction of the tumor with immunoglobulins) the tumor, directly or indirectly, alters the phenotype of its interaction partners thereby enlisting them to promote its progression. Does the tumor need all these pathways to form metastasis? Is there a hierarchy of interactions with respect to impact on tumor progression? These questions remain open. They may be answered by approaches employed in the analysis of hypercomplex systems.

Ablation of the central noradrenergic neurons for unraveling their roles in stress and anxiety.

Despite considerable evidence suggesting the relationship between the central noradrenergic (NA) system and fear/anxiety states, previous animal studies have not demonstrated sheer involvement of the locus coeruleus (LC) in mediating fear or anxiety. Following the negative results of 6-hydroexydopamine (6-OHDA)-induced LC ablation in fear-conditioning studies, most researchers dared not approach this problem using the ablation strategy. The results obtained by a limited number of endeavors, conducted later, were not consistent with the idea of LC being related to anxiety, either, with the exception of the study by Lapiz and colleagues. Since methodological problems were recognized in the neurotoxin-induced NA ablation, employed in previous studies, a novel mouse model was developed in which the LC-NA neurons were ablated selectively and thoroughly by the immunotoxin-mediated cellular targeting. The use of this model clearly demonstrated that the LC was part of the anxiety circuitry. The reason for the discrepancy between the latest study and previous ones is not clear, but it may be due either to the difference in the experimental paradigms or to the different methods for LC ablation. In any case, our findings have shed light on the LC as a locus pertaining to anxiety behavior, and may help link the apparently inconsistent results in previous studies. In addition, the novel method for the LC cell targeting, presented here may provide a potential means for studying the physiological roles of the LC including sleep/wakefulness, as well as its possible involvement in the pathogenesis of psychiatric disorders, including depression, anxiety disorders, and attention deficit/hyperactivity disorder.

[Cardiomyocyte survival and DNA repair in myocardium from C57Bl/6 and mdx mice after dynamical stress].

Mdx mice cardiomyocytes are a perspective model to study survival of terminally differentiated cardiomyocytes and formation of cardiomyopathy under conditions of oxidative stress. It was previously observed that dynamical stress induced formation of low molecular DNA fragments. It is beyond question that DNA fragmentation develops because of formation of double strand DNA breaks (DNA DSB). To record appearance and disappearance of DNA DSB we used antibodies to phosphorylated histone H2Ax (histone gamma-H2Ax.). The presence of DNA DSB was estimated in 0.05% and 6.7% of cardiomyocytes in the myocardium form C57B1 and mdx mice without stress, respectively. The part of cardiomyocytes with DNA DSB increased in an hour after stress up to 1.0% and 41.7% in C57B1 and mdx mice, respectively. In 24 h after stress, the myocardium from mdx mice contained 5.2% of gamma-H2Ax-positive cardiomyocytes and no C57B1 myocardium was found with any amount of gamma-H2Ax-positive cells. The results presented show induction of DNA damage by dynamical stress and restoration of normal DNA structure in the cells of both strains in 24 h after stress. There was no mdx mice death after used dynamical stress. To estimate the real contribution of DNA repair to the survival of cardiomyocytes we have counted the cardiomyocyte loss. Morphometric analysis demonstrated that cell concentration in myocardium from mdx mice under normal conditions was less than that one in myocardium of C57B1/6. The cell loss varied between 20% for the base and 40% for the apex of mdx mice hearts. In 24 h after stress, the cell loss in the myocardium of mdx mice amounted to 2.5%. The difference between the number of cells with damaged DNA structure and the index of the real cell loss allows concluding that DNA repair makes a real contribution to the survival of mdx mice cardiomyocytes after dynamical stress.

Effect of bad collocation of wing tag on feather amelanosis, heterophil-to-lymphocyte ratio, fluctuating asymmetry, and tonic immobility duration in white-faced black spanish hens.

The purpose of the present study was to analyze the effects of bad collocation of the wing tag on feather amelanosis, the heterophil-to-lymphocyte ratio, fluctuating asymmetry, and tonic immobility duration at 140 d of age in hens from the White-Faced Black Spanish breed. A total of 52 females were used. There was a significant difference (P < 0.05) for the heterophil-to-lymphocyte ratio and the tonic immobility duration between groups of females with bad or good collocation of the wing tag, with the ratio being higher and the duration being longer in the former group. Females with bad collocation of the wing tag had significant heterophilia and lymphopenia (P < 0.05). There was a significant difference (P < 0.05) in the fluctuating asymmetry of the middle and hind toe lengths, the combined asymmetry of the 4 toes, the fluctuating asymmetry of the earlobe area, and the combined asymmetry of toe and leg lengths and earlobe and wattle areas, with the asymmetry of birds with bad collocation of the wing tag being larger than that of birds with good collocation of the wing tag. Results indicate that bad collocation of the wing tag negatively affects measures of stress, such as the heterophil-to-lymphocyte ratio, fluctuating asymmetry, and tonic immobility duration.

[Current conception of stress and adaptation subject to new data of tissue hypoxia genesis].

State-of-the-art conception of stress is represented as an interrelation between stress, tissue hypoxia and adaptation. Under the influence of stressors the cell metabolism changes with producing of chemical substances capable pathologically to get bound with cell receptors. These substances change in cells optimal energy transformation (biochemical stage) and disturb cell functions (pharmacological stage). Biochemical and pharmacological stages of stress in uncellulates and in human cells are homotypic. The clinical stage of stress is typical only for humans and animals. Dysfunction of plane muscles (PM) myocytes leads to local microcirculation disturbances, transitory hypoxia and partial disorder in affected organ function. Local microcirculation disturbances are accompanied by serotonin release from damaged platelets, which leads to complete functional recovery of PM myocytes, microcirculation and affected organ function, or to formation of local "mute" focuses of tissue necrosis--the adaptation is effective. Insufficient serotonin release from damaged platelets leads to extension of hypoxia focus, lesion, tissue necrosis. The stress loses its nonspecificity and turns into infarction of myocard, brain etc., with specific clinical course--the adaptation is not effective.

Stress alters the cellular and proteomic compartments of bovine bronchoalveolar lavage fluid.

The stresses of transportation, weaning and commingling are associated with an increased incidence of bacterial and viral pneumonia in cattle. Proteins expressed in the epithelial lining fluid (ELF) of the lungs, in conjunction with resident leukocytes, represent the first line of defence against opportunistic pathogens, and stress-induced alterations in their expression may reveal markers of disease susceptibility. Bronchoalveolar lavage fluid was sampled in weaned and transported calves and ELF protein expression was compared to a control group of calves using two-dimensional electrophoresis (2DE). Serum and pulmonary haptoglobin were increased following stress concurrent with the number of blood neutrophils. Using 2DE, significant changes in expression were observed in spots identified by mass spectrometry as annexin A1 and A5, odorant-binding protein (OBP), isocitrate dehydrogenase, fibrinogen, heme-binding protein, alpha-2-HS-glycoprotein, alpha-1-antichymotrypsin and albumin. Quantification of OBP mRNA by real-time RT-PCR and OBP protein by western blot revealed gender-dependent differences in relative OBP expression in response to stress. These findings reveal stress-associated protein changes in pulmonary ELF and suggest a mechanism through which stress alters respiratory disease susceptibility.

Characterization of stress-induced suppression of long-term potentiation in the hippocampal CA1 field of freely moving rats.

Several lines of evidence have shown that exposure to stress impairs long-term potentiation (LTP) in the CA1 field of the hippocampus, but the detailed mechanisms for this effect remain to be clarified. The present study elucidated the synaptic mechanism of stress-induced LTP suppression in conscious, freely moving rats using electrophysiological approaches. Open field stress (i.e., novel environment stress) and elevated platform stress (i.e., uncontrollable stress) were employed. Basal synaptic transmission was significantly reduced during exposure to elevated platform stress but not during exposure to open field stress. LTP induction was blocked by elevated platform stress but not influenced by open field stress. Significant increases in serum corticosterone levels were observed in the elevated platform stress group compared with the open field stress group. Furthermore, LTP suppression induced by elevated platform stress was prevented by pretreatment with an anxiolytic drug diazepam (1 mg/kg, i.p.). These results suggest that stress-induced LTP suppression depends on the relative intensity of the stressor. The inhibitory synaptic response induced by an intense psychological stress, such as elevated platform stress, may be attributable to LTP impairment in the CA1 field of the hippocampus.

Increasing daily feeding occasions in restricted feeding strategies does not improve performance or well being of fattening pigs.

BACKGROUND: The natural feeding behaviour of the pig is searching for feed by rooting activities throughout the day; self-feeding pigs randomly space their eating and drinking periods throughout the day consuming ten to twelve meals per day. Pigs in conventional fattening pig production are normally fed 2-3 times daily with the feed consumed within 15 minutes. The aim of this study was to determine if more frequent feedings could improve the performance of conventionally kept fattening pigs. METHODS: The experiment was carried out on 360 fattening pigs (27-112 kg live weight), weighed and assigned to pens stratified by weight and sex. Each treatment group consisted of 180 pigs, allocated to 20 pens with nine pigs in each pen. To evaluate how more feeding occasions affects performance and well-being the pigs were divided into two groups and fed three (control group) or nine (treatment group) times daily. The same total amount of liquid feed was fed to each group and the feed ration was correlated to the live weight of the pigs. All weight and slaughter recordings were made individually and recordings of feed consumption were made pen-wise. At slaughter the stomach of each pig was examined for lesions in the pars oesophagea and scored on a scale from 1-6. RESULTS: Frequent feeding occasions influenced both performance and status of gastric lesions of the pigs adversely. Pigs in the treatment group grew slower compared to pigs in the control group; 697 g/day (+/- 6.76) versus 804 g/day (+/- 6.78) (P < 0.001) with no difference in within-pen variation. There was also a lower prevalence of gastric lesions within pigs in the control group (2.4 (+/- 0.12) compared to 3.0 (+/- 0.12) (P < 0.01)). There was a positive correlation between gastric lesions in the treatment group and daily weight gain (r = 0.19; P < 0.01). CONCLUSION: Increased daily feeding occasions among group housed pigs resulted in a poorer daily weight gain and increased mean gastric lesion score as compared with pigs fed three times daily. This may be a consequence of more frequently occurring competition for feed in the treatment group. The present study does not support increased daily feeding occasions in fattening pigs.

Stress and glucocorticoid footprints in the brain-the path from depression to Alzheimer's disease.

Increasingly, stress is recognized as a trigger of depressive episodes and recent evidence suggests a causal role of stress in the onset and progression of Alzheimer's disease (AD) pathology. Besides aging, sex is an important determinant of prevalence rates for both AD and mood disorders. In light of a recent meta-analysis indicating that depressed subjects have a higher likelihood of developing AD, a key message in this article will be that both depression and AD are stress-related disorders and may represent a continuum that should receive more attention in future neurobiological studies. Accordingly, this review considers some of the cellular mechanisms that may be involved in regulating this transition threshold. In addition, it highlights the importance of addressing the question of how aging and sex interplay with stress to influence mood and cognition, with a bias towards consideration of neuroplastic events in particular brain regions, as the basis of AD and depressive disorders.

Histopathology of the alarm reaction in small odontocetes.

Pathological changes in the organs and tissues of beach-stranded, net-caught or captive small odontocete cetaceans (whales and dolphins) are reported. These changes include contraction band necrosis of cardiac and smooth muscles, smooth muscle spasm, ischemic injury to the intestinal mucosa (especially the mucosa of the small intestine) and acute tubular necrosis (ATN) of the proximal tubules of the nephron. Spastic contraction of terminal bronchiolar muscular sphincters was also observed. The changes are consistent with multi-systemic injury caused by massive release of endogenous catecholamines or vasospasm leading to ischemic injury, followed by reperfusion and reperfusion injury. The histopathological findings suggest that the reflex response of an odontocete to any major perceived threat (the "alarm reaction") is to activate the physiological adaptations to diving or escape to an extreme or pathological level, resulting, if greatly prolonged, in widespread ischemic injury to tissues. These observations may explain why these species die abruptly from handling or transportation and why the mortality of highly stressed beach-stranded animals is very high.

Opposing actions of chronic stress and chronic nicotine on striatal function in mice.

Stress is a major risk factor in drug addiction development and relapse. Virtually all drugs of abuse act by increasing extracellular dopamine levels in the striatum. To gain an understanding of the interaction between stress and drug exposure, we studied the effects of concomitant chronic nicotine and chronic stress exposure on mouse striatal dopamine levels. C57Bl6/J mice were treated with nicotine in the drinking water or control solution for at least 6 weeks. Some mice were chronically stressed by daily exposure to cold, shaking or restrain. Nicotine-treated mice showed up-regulation of epibatidine binding in several brain regions. In mice treated with both chronic nicotine and stress, epibatidine binding was increased in all studied areas except the dorsal striatum. Therefore, microdialysis was used to measure extracellular dopamine levels in the dorsal striatum of mice chronically treated with nicotine, stress, or both. To have a measure of striatal response to different challenges, we performed microdialysis after acute injection of saline, nicotine, and cocaine. Chronic nicotine enhanced nicotine-dependent dopamine release, while chronic stress blunted the response to cocaine. When mice were subjected to both chronic nicotine and chronic stress, nicotine- and cocaine-dependent dopamine release was undistinguishable from that of control animals. In conclusion, our data suggest that chronic stress and chronic nicotine counteract each other's effect on dopamine release in the striatum. This effect might be mediated by changes in nicotinic acetylcholine receptor up-regulation. This "normalization" of striatal function when both nicotine and stress are present might help explain the comorbidity between stress-related disorders and drug abuse.