The gateway reflex is a mechanism by which neural inputs regulate chemokine expression at endothelial cell barriers, thereby establishing gateways for the invasion of autoreactive T cells into barrier-protected tissues. In this study, we hypothesized that rod photoreceptor dysfunction causes remodeling of retinal neural activity, which influences the blood-retinal barrier and the development of retinal inflammation. We evaluated this hypothesis using Gnat1rd17 mice, a model of night blindness with late-onset rod-cone dystrophy, and experimental autoimmune uveoretinitis (EAU). Retinal remodeling and its effect on EAU development were investigated by transcriptome profiling, target identification, and functional validation. We showed that Gnat1rd17 mice primarily underwent alterations in their retinal dopaminergic system, triggering the development of an exacerbated EAU, which was counteracted by dopamine replacement with L-DOPA administered either systemically or locally. Remarkably, dopamine acted on retinal endothelial cells to inhibit NF-κB and STAT3 activity and the expression of downstream target genes such as chemokines involved in T cell recruitment. These results suggest that rod-mediated dopamine release functions in a gateway reflex manner in the homeostatic control of immune cell entry into the retina, and the loss of retinal dopaminergic activity in conditions associated with rod dysfunction increases the susceptibility to autoimmune uveitis.

• MeSH
• buněčné linie MeSH
• dopamin metabolismus   MeSH
• endoteliální buňky metabolismus   patologie   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• NF-kappa B metabolismus   MeSH
• retina metabolismus   patologie   MeSH
• transkripční faktor STAT3 metabolismus   MeSH
• uveitida metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The brain, spinal cord and retina are protected from blood-borne compounds by the blood-brain barrier (BBB), blood-spinal cord barrier (BSCB) and blood-retina barrier (BRB) respectively, which create a physical interface that tightly controls molecular and cellular transport. The mechanical and functional integrity of these unique structures between blood vessels and nervous tissues is critical for maintaining organ homeostasis. To preserve the stability of these barriers, interplay between constituent barrier cells, such as vascular endothelial cells, pericytes, glial cells and neurons, is required. When any of these cells are defective, the barrier can fail, allowing blood-borne compounds to encroach neural tissues and cause neuropathologies. Autoimmune diseases of the central nervous system (CNS) and retina are characterized by barrier disruption and the infiltration of activated immune cells. Here we review our recent findings on the role of neural activity in the regulation of these barriers at the vascular endothelial cell level in the promotion of or protection against the development of autoimmune diseases. We suggest nervous system reflexes, which we named gateway reflexes, are fundamentally involved in these diseases. Although their reflex arcs are not completely understood, we identified the activation of specific sensory neurons or receptor cells to which barrier endothelial cells respond as effectors that regulate gateways for immune cells to enter the nervous tissue. We explain this novel mechanism and describe its role in neuroinflammatory conditions, including models of multiple sclerosis and posterior autoimmune uveitis.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

We have reported the gateway reflex, which describes specific neural activations that regulate immune cell gateways at specific blood vessels in the central nervous system (CNS). Four types of gateway reflexes exist, all of which induce alterations in endothelial cells at specific vessels of the blood-brain barrier followed by inflammation in the CNS in the presence of CNS-autoreactive T cells. Here we report a new gateway reflex that suppresses the development of retinal inflammation by using an autoreactive T cell-mediated ocular inflammation model. Exposure to photopic light down-regulated the adrenoceptor pathway to attenuate ocular inflammation by suppressing breaching of the blood-retina barrier. Mechanistic analysis showed that exposure to photopic light down-regulates the expression of α1A-adrenoceptor (α1AAR) due to high levels of norepinephrine and epinephrine, subsequently suppressing inflammation. Surgical ablation of the superior cervical ganglion (SCG) did not negate the protective effect of photopic light, suggesting the involvement of retinal noradrenergic neurons rather than sympathetic neurons from the SCG. Blockade of α1AAR signaling under mesopic light recapitulated the protective effect of photopic light. Thus, targeting regional adrenoceptor signaling might represent a novel therapeutic strategy for autoimmune diseases including those that affect organs separated by barriers such as the CNS and eyes.

• MeSH
• adrenalin metabolismus   MeSH
• adrenergní látky metabolismus   MeSH
• adrenergní receptory metabolismus   MeSH
• alfa-1-adrenergní receptory metabolismus   MeSH
• autoimunita genetika   fyziologie   MeSH
• autoimunitní nemoci imunologie   MeSH
• centrální nervový systém metabolismus   MeSH
• endoteliální buňky metabolismus   MeSH
• ganglion cervicale superius metabolismus   MeSH
• hematoencefalická bariéra metabolismus   MeSH
• hematoretinální bariéra metabolismus   MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• neurony metabolismus   MeSH
• noradrenalin metabolismus   MeSH
• retinitida patofyziologie   MeSH
• světlo MeSH
• T-lymfocyty imunologie   MeSH
• vidění barevné fyziologie   MeSH
• zánět metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• alergologie a imunologie MeSH
• klinické praxe MeSH
• kontinuální vzdělávání lékařů MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Japonsko MeSH

Cachectic rheumatoid arthritis, the less frequent form of the disease, is associated with loss of fat mass and often more severe course of the disease. Its experimental model represents rat adjuvant arthritis (AA) characterized by edema, lack of appetite, sharp body weight and fat loss. As individual fat depots display functional differences, here we studied lipolytic activity and sensitivity to lipolytic stimuli of nodeless epididymal fat (eWAT) and perinodal mesenteric fat (mWAT) depots at the peak of AA. We also examined changes in catecholamine and cytokine levels involved in lipolysis in plasma and/or isolated adipocytes from both WATs to identify the contribution of local, adipocyte-based processes and/or systemic events to adiposity loss in cachectic rheumatoid arthritis. AA was induced to male Lewis rats by complete Freund's adjuvant. Groups of ad libitum-fed and pair-fed controls were used to distinguish the effects of food restriction from inflammation-induced cachexia. Adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and its phosphorylated form (pHSL) were analyzed by western blot. CRP and catecholamine levels in plasma or adipocyte lysates were determined using ELISA kits. Cytokine-induced neutrophil chemoattractant-1 (CINC-1/CXCL1), monocyte chemoattractant protein-1 (MCP-1/CCL2), IL-1β, IL-6, IL-10 and leptin in adipocyte lysate were analyzed by quantitative protein microarray. Plasma glycerol and FFA were measured spectrophotometrically. AA rats developed severe cachexia, with lower adiposity in mWAT compared to normal and pair-fed controls, whereas in eWAT the adiposity was similarly reduced in AA and pair-fed groups. ATGL levels in both WATs were not affected by AA or pair feeding. AA upregulated levels of HSL, pHSL and pHSL/HSL ratio in mWAT, whereas none of these parameters has changed in eWAT of AA rats or in either WATs of pair-fed rats. In AA rats plasma glycerol was elevated, whereas FFA concentration was reduced. Plasma norepinephrine and epinephrine were increased in AA compared with both groups of controls. In eWAT adipocytes, AA but not pair feeding, upregulated norepinephrine levels. In mWAT adipocytes, AA rats showed higher epinephrine levels than pair-fed controls. Leptin levels in both WATs were depleted in AA animals in accordance with body weight loss. None of the measured cytokines in eWAT and mWAT was enhanced. Our results demonstrate augmented lipolytic activity in mWAT and not eWAT during cachectic arthritis. The adipocyte-derived cytokines do not seem to contribute to activated lipolysis. We first demonstrated enhanced presence of norepinephrine in perinodal adipocytes that may contribute to the regulation of local lipolytic activity by auto/paracrine fashion and thus provide independent fuel supply to activated lymph nodes.

• MeSH
• adrenalin biosyntéza   MeSH
• artritida experimentální imunologie   metabolismus   MeSH
• biologické markery MeSH
• C-reaktivní protein MeSH
• epididymis metabolismus   MeSH
• humorální imunita MeSH
• krysa rodu rattus MeSH
• lipolýza MeSH
• mezenterium metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• sterolesterasa metabolismus   MeSH
• tukové buňky metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

We studied the effect of food restriction, overfeeding, and normofeeding on cachexia, inflammatory and metabolic parameters, and insulin sensitivity in chronic adjuvant arthritis (AA) in rats. Food restriction during AA increased circulating ghrelin, corticosterone, decreased leptin, and ameliorated arthrogram score and systemic inflammation compared to normofeeding. Overfeeding worsened arthrogram score and systemic inflammation, and led to lipid accumulation in the liver, but not to alterations of adipokine and ghrelin plasma levels relative to normofeeding. Independently of feeding status, AA induced cachexia, in which modulation of mRNA expressions for appetite-regulating neuropeptides (NPY, AgRP, POMC, CART) in the arcuate nucleus (ARC) does not play a primary role. The overexpression of IL-1β mRNA in the ARC suggests its role in the mechanisms of impaired energy balance during AA under all feeding conditions. Normal HOMA index in all arthritic groups does not indicate the development of insulin resistance by feeding interventions in these rats.

• MeSH
• adipokiny metabolismus   MeSH
• adjuvantní chemoterapie metody   MeSH
• artritida dietoterapie   terapie   MeSH
• ghrelin metabolismus   MeSH
• hormony kůry nadledvin metabolismus   MeSH
• inzulin metabolismus   MeSH
• kachexie metabolismus   MeSH
• krmivo pro zvířata MeSH
• krysa rodu rattus MeSH
• leptin metabolismus   MeSH
• neuropeptidy chemie   MeSH
• nucleus arcuatus hypothalami metabolismus   MeSH
• potkani inbrední LEW MeSH
• zánět MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Adipokines play a significant role in the pathogenesis of a low-grade inflammation associated with obesity and metabolic syndrome, and in chronic inflammatory and autoimmune diseases such as rheumatoid arthritis. Among variety of adipokines, resistin and visfatin are proposed as important pro-inflammatory mediators, which also interfere with the central regulation of insulin sensitivity. Resistin has been initially postulated as a risk factor for insulin resistance, however, the subsequent available data on it have revealed contradictory findings in both humans and rodents. On the other hand, visfatin has been suggested to be a beneficial adipokine with insulin-mimicking/-sensitizing effects, but regulation of visfatin production and its physiological importance in the conditions of obesity and type 2 diabetes mellitus are still not completely understood. Despite the opposing effects of resistin and visfatin on the regulation of insulin sensitivity, both adipokines have pro-inflammatory properties. Clinical and experimental studies have shown that the expression and secretion of resistin and visfatin are up-regulated during inflammation and in response to pro-inflammatory cytokines. It has also become increasingly evident that resistin as well as visfatin itself can contribute to the inflammatory processes by triggering cytokine production and NF-kappaB activation. New insight into the role of adipokines makes them attractive targets for novel therapeutic strategies in chronic inflammatory diseases or subclinical inflammation relating to obesity and various metabolic abnormalities.

• MeSH
• autoimunita MeSH
• inzulin metabolismus   MeSH
• inzulinová rezistence MeSH
• lidé MeSH
• mediátory zánětu metabolismus   MeSH
• nikotinamidfosforibosyltransferasa metabolismus   MeSH
• resistin metabolismus   MeSH
• signální transdukce MeSH
• zánět imunologie   metabolismus   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

OBJECTIVE: Obesity represents a low-grade inflammatory disease and appears a risk factor for insulin resistance, but little is known on whether this may contribute to the development of autoimmune inflammatory diseases. The aim of this work was to study the early-life diet-induced obesity in Lewis rats which are known to be highly susceptible to autoimmunity. METHODS: Obesity was induced by reduced litter size (4 pups per litter) followed by high-fat diet (SHF rats). Control rats (8 pups per litter) were fed with standard diet (CN rats). Oral glucose tolerance test (3 g glucose per kg b.w.) was performed by intra-gastric tube in conscious rats after 12 h fast. Adipocyte size was assessed by light microscope after collagenase digestion. Hypothalamic arcuate (ARC) and paraventricular nuclei (PVN) were isolated by the punching technique. Target mRNAs were quantified by real-time PCR with the use of TaqMan probes and primers. Serum hormones (leptin, ghrelin, adiponectin, visfatin and insulin) were assayed by specific RIAs . RESULTS: During the experimental period SHF rats had the same body weight gain and caloric intake as CN rats. At the age of 8 weeks SHF rats showed increased epididymal fat mass and adipocyte volume, impaired glucose tolerance, normal basal fasting insulin, visfatin, and ghrelin level, but decreased adiponectin and high leptin level. In the ARC, the SHF rats showed increased expression of mRNA for orexigenic neuropeptide Y (NPY), agouti-related protein (AgRP) and anorexigenic pro-inflammatory cytokine IL-6. In the PVN, the SHF rats showed increased expression of mRNA for anorexigenic melanocortin 4 receptor (MC4R) and IL-6. CONCLUSION: Overexpression of orexigenic NPY and AgRP in the ARC indicates leptin resistance in SHF rats. The increased expression of MC4R in PVN points to the activation of melanocortin anorexigenic system which, along with increased hypothalamic IL-6, might prevent the animals from overfeeding. Higher adiposity in these rats results from the high fat-diet composition and not from increased caloric intake. Furthermore, enhanced leptin production appears the main factor indicating the predisposition to autoimmunity in these overfed rats.

• MeSH
• adiponektin krev   MeSH
• adipozita MeSH
• AGRP protein genetika   metabolismus   MeSH
• analýza rozptylu MeSH
• bílá tuková tkáň cytologie   MeSH
• bílé tukové buňky MeSH
• dietní tuky aplikace a dávkování   MeSH
• energetický příjem MeSH
• exprese genu MeSH
• ghrelin krev   MeSH
• interleukin-6 genetika   metabolismus   MeSH
• inzulin krev   MeSH
• krysa rodu rattus MeSH
• leptin krev   MeSH
• messenger RNA metabolismus   MeSH
• neuropeptid Y genetika   metabolismus   MeSH
• nikotinamidfosforibosyltransferasa krev   MeSH
• nucleus arcuatus hypothalami metabolismus   MeSH
• nucleus paraventricularis hypothalami metabolismus   MeSH
• obezita genetika   metabolismus   MeSH
• plocha pod křivkou MeSH
• porucha glukózové tolerance MeSH
• potkani inbrední LEW MeSH
• receptor melanokortinový typ 4 genetika   metabolismus   MeSH
• regulace chuti k jídlu fyziologie   MeSH
• stárnutí MeSH
• stravovací zvyklosti MeSH
• tělesná hmotnost MeSH
• velikost buňky MeSH
• velikost vrhu MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

OBJECTIVE: Food intake is activated by hypothalamic orexigenic neuropeptide Y (NPY), which is mainly under the dual control of leptin and ghrelin. Rat adjuvant arthritis (AA), similarly as human rheumatoid arthritis, is associated with cachexia caused by yet unknown mechanisms. The aim of our study was to evaluate NPY expression in hypothalamic arcuate nuclei (nARC) under the conditions of AA-induced changes in leptin, ghrelin and adiponectin. Since IL-1beta is involved in the central induction of anorexia, we studied its expression in the nARC as well. METHODS: AA was induced to Lewis rats using complete Freund's adjuvant. On days 12, 15 and 18 after complete Freund's adjuvant injection, the levels of leptin, adiponectin, ghrelin and IL-1beta were determined by RIA or ELISA. The mRNA expressions for NPY, leptin receptor (OB-R), ghrelin receptor (Ghsr) and IL-1beta were determined by TaqMan RT-PCR from isolated nARC. RESULTS: In AA rats, decreased appetite, body mass and epididymal fat stores positively correlated with reduced circulating and epididymal fat leptin and adiponectin. Ghrelin plasma levels were increased. In nARC, mRNA for OB-R, Ghsr and NPY were overexpressed in AA rats. AA rats showed overexpression of mRNA for IL-1beta in nARC while circulating, and spleen IL-1beta was unaltered. CONCLUSION: During AA, overexpression of orexigenic NPY mRNA in nARC along with enhanced plasma ghrelin and lowered leptin levels occur. Decreased food intake indicates a predominant effect of the anorexigenic pathway. Activated expression of IL-1beta in nARC suggests its role in keeping AA-induced anorexia in progress. The reduction in adiponectin may also contribute to AA-induced anorexia. Copyright 2009 S. Karger AG, Basel.

• MeSH
• adiponektin metabolismus   MeSH
• artritida chemicky indukované   komplikace   MeSH
• chuť k jídlu fyziologie   MeSH
• ghrelin krev   sekrece   MeSH
• interleukin-1beta genetika   MeSH
• krysa rodu rattus MeSH
• leptin krev   sekrece   MeSH
• messenger RNA metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• nechutenství genetika   metabolismus   patofyziologie   MeSH
• neuropeptid Y genetika   MeSH
• nucleus arcuatus hypothalami metabolismus   sekrece   MeSH
• potkani inbrední LEW MeSH
• regulace chuti k jídlu fyziologie   MeSH
• regulace genové exprese fyziologie   MeSH
• signální transdukce fyziologie   MeSH
• systém hypotalamus-hypofýza metabolismus   sekrece   MeSH
• upregulace fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

There is a growing evidence that both overnutrition and undernutrition negatively interfere with immune system. The overnutrition has been found to increase susceptibility to the development of inflammatory or autoimmune diseases. On the other hand, starvation or malnutrition has been more associated with increased susceptibility to infections. In the regulation of immune and inflammatory processes, white adipose tissue plays a critical role as an endocrine organ which produces number of active peptides, called adipokines. The adipokines, leptin and adiponectin represent a critical link among nutritional status, metabolism and immunity. Leptin is primarily known as a satiety factor regulating body weight by suppression of appetite and stimulation of energy expenditure, and its serum levels and gene expression in adipocytes strongly correlate with proportion of body fat stores. On the other hand, leptin is a pro-inflammatory adipokine inducing T helper 1 cells and may contribute to the development and progression of autoimmune responses. Adiponectin plays an important role as an insulin-sensitizing adipokine which production is decreased in obesity and in conditions associated with insulin resistance. Adiponectin also acts as an anti-inflammatory factor especially with regard to atherosclerosis, but in some chronic inflammatory/autoimmune diseases adiponectin may have pro-inflammatory effects and its production correlates with inflammatory markers and disease activity. This review discusses the main biological activities of leptin and adiponectin as well as their contribution to inflammatory and autoimmune processes with particular focus on rheumatoid arthritis and its experimental models.

• MeSH
• adiponektin biosyntéza   fyziologie   MeSH
• autoimunita MeSH
• energetický metabolismus MeSH
• fyziologie výživy MeSH
• leptin fyziologie   MeSH
• lidé MeSH
• revmatoidní artritida MeSH
• tuková tkáň metabolismus   MeSH
• zánět MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH