Can lifelong endurance exercise improve ageing through beneficial effects on circadian timing function, muscular performance and health status in men? Protocol for a comparative cross-sectional study.

A well-synchronized circadian system is a manifestation of an individual's health. A gradual weakening of the circadian timing function characterizes aging. Regular exercise has been suggested as a modality to improve many detrimental changes associated with aging. Therefore, we aim to examine the benefits and risks of lifelong endurance exercise on age-dependent changes in the circadian time-keeping function, the performance of the muscular system and health status. The study protocol has a comparative cross-sectional design, including groups of senior (65 to 75 years old, n=16) and young (20-30 years old, n=16) endurance runners and triathletes. Age-matched groups of young and elderly sedentary men are included as controls. The circadian function is evaluated mainly by measurement of urinary 6-sulphatoxymelatonin, a metabolite of the hormone melatonin shown to participate in the modulation of sleep cycles. The 6-sulphatoxymelatonin will be assessed in urine samples collected upon awakening in the morning and in the late evening, as a marker of melatonin production. In addition, sleep/activity rhythms and sleep quality will be measured by wrist actigraphy. Performance of the muscular system will be assessed by examination of muscular strength and quantifying of gene expression in the skeletal muscle tissue samples. Health status and age-induced reduction in immune function are to be analysed via the balance of pro- and anti-inflammatory immune markers in the plasma and skeletal muscle, body composition, bone density and physical fitness.

Dynamics of cachexia-associated inflammatory changes in the brain accompanying intra-abdominal fibrosarcoma growth in Wistar rats.

Accumulated data indicate that inflammation affecting brain structures participates in the development of cancer-related cachexia. However, the mechanisms responsible for the induction and progression of cancer-related neuroinflammation are still not fully understood. Therefore, we studied the time-course of neuroinflammation in selected brain structures and cachexia development in tumor-bearing rats. After tumor cells inoculation, specifically on the 7th, 14th, 21st, and 28th day of tumor growth, we assessed the presence of cancer-associated cachexia in rats. Changes in gene expression of inflammatory factors were studied in selected regions of the hypothalamus, brain stem, and circumventricular organs. We showed that the initial stages of cancer growth (7th and 14th day after tumor cells inoculation), are not associated with cachexia, or increased expression of inflammatory molecules in the brain. Even when we did not detect cachexia in tumor-bearing rats by the 21st day of the experiment, the inflammatory brain reaction had already started, as we found elevated levels of interleukin 1 beta, interleukin 6, tumor necrosis factor alpha, and glial fibrillary acidic protein mRNA levels in the nucleus of the solitary tract. Furthermore, we found increased interleukin 1 beta expression in the locus coeruleus and higher allograft inflammatory factor 1 expression in the vascular organ of lamina terminalis. Ultimately, the most pronounced manifestations of tumor growth were present on the 28th day post-inoculation of tumor cells. In these animals, we detected cancer-related cachexia and significant increases in interleukin 1 beta expression in all brain areas studied. We also observed significantly decreased expression of the glial cell activation markers allograft inflammatory factor 1 and glial fibrillary acidic protein in most brain areas of cachectic rats. In addition, we showed increased expression of cluster of differentiation 163 and cyclooxygenase 2 mRNA in the hypothalamic paraventricular nucleus, A1/C1 neurons, and area postrema of cachectic rats. Our data indicate that cancer-related cachexia is associated with complex neuroinflammatory changes in the brain. These changes can be found in both hypothalamic as well as extrahypothalamic structures, while their extent and character depend on the stage of tumor growth.

Aging and Possible Benefits or Negatives of Lifelong Endurance Running: How Master Male Athletes Differ from Young Athletes and Elderly Sedentary?

Regular physical activity, recommended by the WHO, is crucial in maintaining a good physical fitness level and health status and slows down the effects of aging. However, there is a lack of knowledge of whether lifelong endurance running, with a volume and frequency above the WHO limits, still brings the same benefits, or several negative effects too. The present study aims to examine the protentional benefits and risks of lifelong endurance running training in Master male athletes, as this level of physical activity is above the WHO recommendations. Within the study, four main groups of participants will be included: (1) endurance-trained master athletes, (2) endurance-trained young athletes, (3) young sedentary adults, and (4) elderly sedentary. Both groups of athletes are strictly marathon runners, who are still actively running. The broad spectrum of the diagnostic tests, from the questionnaires, physical fitness testing, and blood sampling to muscle biopsy, will be performed to obtain the possibility of complexly analyzing the effects of lifelong endurance physical activity on the human body and aging. Moreover, the study will try to discover and explain new relationships between endurance running and diagnostic parameters, not only within aging.

Chronic propranolol treatment moderately attenuated development of N-methyl-N-nitrosourea-induced mammary carcinoma in female rats.

The sympathetic nervous system participates in the development and progression of several cancer types and this effect is mediated mainly via ß-adrenergic signaling. However, the potential of ß-adrenergic signaling blockade to prevent cancer development after exposure to carcinogens has not been investigated, yet. Therefore, in our study, we determined the effect of the ß-blocker propranolol on the development and progression of mammary cancer induced in female rats by administration of the chemical carcinogen N-methyl-N-nitrosourea (MNU). The propranolol treatment (20 mg/kg body weight) started 12 days after MNU administration and lasted 10 weeks. We found that both saline and propranolol treatment significantly increased gene expression of the catecholamine-synthesizing enzyme tyrosine hydroxylase, indicating that repeated injection of saline or propranolol-induced stress in these two groups. However, compared to the vehicle-treated group, propranolol slightly delayed the development and moderately reduced the incidence of mammary carcinoma in animals. To evaluate the mechanisms mediating the effect of propranolol on the development of MNU-induced cancer, we investigated several parameters of the tumor microenvironment and found that propranolol increased gene expression of Casp3. Our data indicate that propranolol treatment that starts after exposure to carcinogens might represent a new, useful approach for preventing the development of cancer, especially in stressed individuals. However, the potential efficiency of propranolol treatment for preventing cancer development and progression in individuals exposed to carcinogens needs further investigation.

Neuroinflammation and depressive disorder: The role of the hypothalamus.

Data accumulated over the last two decades has demonstrated that hypothalamic inflammation plays an important role in the etiopathogenesis of the most prevalent diseases, such as cardiovascular diseases, metabolic syndrome, and even cancer. Recent findings indicate that hypothalamic inflammation is also associated with stress exposure and certain psychiatric diseases, such as depressive disorder. Mechanistic studies have shown that intense and/or chronic stress exposure is accompanied by the synthesis of inflammatory molecules in the hypothalamus, altered hypothalamic-pituitary-adrenal axis activity, and development of glucocorticoid resistance. Consequently, these factors might play a role in the etiopathogenesis of psychiatric disorders. We propose that hypothalamic inflammation represents an interconnection between somatic diseases and depressive disorder. These assumptions are discussed in this mini-review in the light of available data from studies focusing on hypothalamic inflammation.

Cachexia induced by Yoshida ascites hepatoma in Wistar rats is not associated with inflammatory response in the spleen or brain.

Recent data indicate that peripheral, as well as hypothalamic pro-inflammatory cytokines play an important role in the development of cancer cachexia. However, there are only a few studies simultaneously investigating the expression of inflammatory molecules in both the periphery and hypothalamic structures in animal models of cancer cachexia. Therefore, using the Yoshida ascites hepatoma rat's model of cancer cachexia we investigated the gene expression of inflammatory markers in the spleen along with the paraventricular and arcuate nuclei, two hypothalamic structures that are involved in regulating energy balance. In addition, we investigated the effect of intracerebroventricular administration of PS-1145 dihydrochloride (an Ikß inhibitor) on the expression of selected inflammatory molecules in these hypothalamic nuclei and spleen. We observed significantly reduced food intake in tumor-bearing rats. Moreover, we found significantly decreased expression of IL-6 in the spleen as well as decreased NF-κB in the paraventricular nucleus of rats with Yoshida ascites hepatoma. Similarly, expression of TNF-α, IL-1ß, NF-κB, and COX-2 in the arcuate nucleus was significantly reduced in tumor-bearing rats. Administration of PS-1145 dihydrochloride reduced only the gene expression of COX-2 in the hypothalamus. Based on our findings, we suggest that the growing Yoshida ascites hepatoma decreased food intake by mechanical compression of the gut and therefore this model is not suitable for investigation of the inflammation-related mechanisms of cancer cachexia development.

Clozapine impact on FosB/ΔFosB expression in stress preconditioned rats: response to a novel stressor.

OBJECTIVE: Prolonged treatment with neuroleptics has been shown to induce FosB/ΔFosB expression in several brain regions including the medial prefrontal cortex, dorsomedial and dorsolateral striatum, ventrolateral and dorsolateral septum, nucleus accumbens shell and core, and the hypothalamic paraventricular nucleus (PVN). Some of these regions are known to be also stress responsive. This study was designed to determine whether repeated clozapine (CLZ) administration for 7 consecutive days to Wistar rats may modify FosB/ΔFosB expression in the above-mentioned brain areas induced by acute stress or novel stressor that followed 13-day chronic mild stress preconditioning. METHODS: Following experimental groups were used: unstressed animals treated with vehicle/ CLZ for 7 days; 7-day vehicle/CLZ-treated animals on the last day exposed to acute stress - forced swimming (FSW); and animals preconditioned with stress for 13 days treated from the 8th day with vehicle/CLZ and on the 14th day exposed to novel stress - FSW. RESULTS: In the unstressed animals CLZ markedly increased FosB/ΔFosB immunoreactivity in the ventrolateral septum and PVN. FSW elevated FosB/ΔFosB expression in the medial prefrontal cortex, striatum, and septum. CLZ markedly potentiated the effect of the FSW on FosB/ΔFosB expression in the PVN, but suppressed it in the dorsomedial striatum. Novel stress with stress preconditioning increased FosB/ΔFosB immunoreactivity in the prefrontal cortex, striatum, ventrolateral septum, and the PVN. In the nucleus accumbens the effect of the novel stressor was potentiated by CLZ. CONCLUSION: Our data indicate that CLZ may modulate the acute as well as novel stress effects on FosB/ΔFosB expression but its effect differs within the individual brain regions.

Hypothalamic Inflammation at a Crossroad of Somatic Diseases.

Various hypothalamic nuclei function as central parts of regulators that maintain homeostasis of the organism. Recently, findings have shown that inflammation in the hypothalamus may significantly affect activity of these homeostats and consequently participate in the development of various somatic diseases such as obesity, diabetes, hypertension, and cachexia. In addition, hypothalamic inflammation may also affect aging and lifespan. Identification of the causes and mechanisms involved in the development of hypothalamic inflammation creates not only a basis for better understanding of the etiopathogenesis of somatic diseases, but for the development of new therapeutic approaches for their treatment, as well.

Clozapine impact on c-Fos expression in mild stress preconditioned male rats exposed to a novelty stressor.

Clozapine (CLZ) stimulates several brain areas some of them being sensitive to stress. Aim of the present study was to reveal whether 7-day CLZ administration may: (1) activate the selected forebrain areas; (2) modulate response of these structures to a single forced swimming episode (FSW); (3) modulate response of these structures to FSW after 13-day preconditioning with mild unpredictable stress complex (CMS). Used groups of male Wistar rats: (a) vehicle or CLZ treated for 7 days; (b) vehicle or CLZ treated for 7 days and on the 7th day exposed to FSW; (c) CMS exposed for 13 days, from the 8th day injected with vehicle or CLZ and on the 14th day exposed to FSW. Vehicle or CLZ (10 mg kg-1  day-1 in 0.1% acetic acid) were administered intraperitoneally. c-Fos quantification was performed 90 min after FSW in the medial prefrontal cortex (mPFC), dorsolateral (dLS) and ventrolateral (vLS) septum, dorsolateral (DLStr) and dorsomedial (DMStr) striatum, nucleus accumbens shell (NAc shell) and core (NAc core), and hypothalamic paraventricular nucleus (PVN). In unstressed animals CLZ increased c-Fos expression in the mPFC, vLS, and PVN. After a single FSW, CLZ decreased the number of c-Fos immunoreactive cells in the vLS, DMStr, NAc shell, and NAc core. In CMS rats, CLZ suppressed c-Fos immunoreactivity in response to FSW in the PVN. Our data indicate that CLZ elicits different impact on neuronal activities in the brain areas studied and modifies the response of these structures to stress. CLZ effect seems to be affected by stress duration.

Effect of acute asenapine treatment on Fos expression in the forebrain structures under normal conditions and mild stress preconditioning in the rat.

Asenapine (ASE) is a novel atypical antipsychotic drug approved for the treatment of schizophrenia and bipolar disorder. Stress is an inseparable part of the human life, which may interfere with the therapeutic effect of different drugs. The aim of the present study was: (1) to delineate the quantitative and qualitative profiles of the ASE effect on Fos expression in the striatum, septum, nucleus accumbens, and the prefrontal cortex and (2) to find out whether a chronic unpredictable variable mild stress (CMS) preconditioning may modify the effect of acute ASE treatment. Stress paradigms included restrain, social isolation, crowding, swimming, and cold. The animals were exposed to CMS for 21 days and on the 22nd day received an injection of vehicle (saline 300 µl/rat s.c.) or ASE (0.3mg/kg s.c.). They were sacrificed 90 min after the treatments. Fos protein was visualized by avidin biotin peroxidase (ABC). Four groups of animals were investigated: controls+vehicle, controls+ASE, CMS+vehicle, and CMS+ASE. The number of Fos labeled neurons was calculated per total investigated area, which was selective for each structure, and also recalculated per unified sector. ASE treatment induced significant and very similar increase of the Fos expression in both ASE control and ASE CMS animals in comparison with saline control and CMS ones. Moreover, ASE induced regional differences in the number of Fos-positive neurons. In both ASE groups most pronounced response in the number of Fos profiles occurred in the dorsolateral striatum, ventrolateral septum, shell of the nucleus accumbens, and the medial prefrontal cortex. Mild Fos response was seen in the dorsomedial and ventromedial striatum and core of the nucleus accumbens. No response was seen in the dorsolateral septum. The present paper demonstrates for the first time the character of the Fos distribution in the forebrain structures induced by acute ASE treatment as well as ASE response to 21 days CMS preconditioning. The study provides an important comparative background that may help in the further understanding of the effect of ASE on the brain activation as well as its responsiveness to CMS challenges.