Endogenous opioids: role in prostaglandin-dependent and -independent fever

This study evaluated the participation of mu-opioid-receptor activation in body temperature (T-b) during normal and febrile conditions (including activation of heat conservation mechanisms) and in different pathways of LPS-induced fever. The intracerebroventricular treatment of male Wistar rats with the selective opioid mu-receptor-antagonist cyclic D-Phe-Cys-Try-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP; 0.1-1.0 mu g) reduced fever induced by LPS (5.0 mu g/kg) but did not change Tb at ambient temperatures of either 20 C or 28 C. The subcutaneous, intracerebroventricular, and intrahypothalamic injection of morphine (1.0 -10.0 mg/kg, 3.0 -30.0 mu g, and 1 -100 ng, respectively) produced a dose-dependent increase in Tb. Intracerebroventricular morphine also produced a peripheral vasoconstriction. Both effects were abolished by CTAP. CTAP (1.0 mu g icv) reduced the fever induced by intracerebroventricular administration of TNF-alpha (250 ng), IL-6 (300 ng), CRF (2.5 mu g), endothelin-1 (1.0 pmol), and macrophage inflammatory protein (500 pg) and the first phase of the fever induced by PGF(2 alpha) (500.0 ng) but not the fever induced by IL-1 beta (3.12 ng) or PGE(2) (125.0 ng) or the second phase of the fever induced by PGF(2 alpha). Morphine-induced fever was not modified by the cyclooxygenase (COX) inhibitor indomethacin (2.0 mg/kg). In addition, morphine injection did not induce the expression of COX-2 in the hypothalamus, and CTAP did not modify PGE2 levels in cerebrospinal fluid or COX-2 expression in the hypothalamus after LPS injection. In conclusion, our results suggest that LPS and endogenous pyrogens (except IL-1 beta and prostaglandins) recruit the opioid system to cause a mu-receptor-mediated fever.

Trypanosoma cruzi: Dehydroepiandrosterone (DHEA) and immune response during the chronic phase of the experimental Chagas` disease

Dehydroepiandrosterone (DHEA) has long been considered as a precursor for many steroid hormones. It also enhances the immune responses against a wide range of viral, bacterial, and parasitic pathogens. The aims of this work were to evaluate the influences of exogenous DHEA treatment on Wistar rats infected with the Y strain of Trypanosoma cruzi during the acute and its influence on the chronic phase of infection. Animals were subcutaneous treated with 40 mg/kg body weight/day of DHEA. DHEA treatment promoted increased lymphoproliferative responses as well as enhanced concentrations of NO and IL-12. So, we point in the direction that our results validate the utility of the use of DHEA as an alternative therapy candidate against T cruzi. (C) 2009 Published by Elsevier B.V.

Local delivery of EGF-liposome mediated bone modeling in orthodontic tooth movement by increasing RANKL expression

Aims: It has long been demonstrated that epidermal growth factor (EGF) has catabolic effects oil bone. Thus. we examined the role of EGF in regulating mechanically induced bone modeling in a rat model of orthodontic tooth movement. Main methods: The maxillary first molars of rats were moved mesially using an orthodontic appliance attached to the maxillary incisor teeth. Rats were randomly divided into 4 groups: (G1) administration of PBS (Phosphate buffer saline Solution (n = 24); (G2) administration of empty liposomes (it = 24): (Q) administration 20 rig of EGF Solution (n = 24): and (G4) 20 ng of EGF-liposomes Solution (it = 24). Each Solution was injected in the mucosa of the left first molar adjacent to the appliance. At days 5, 10, 14 and 2 1 after drug administration. 6 animals of each group were sacrificed. Histomorphometric analysis was used to quantify osteoclasts (Tartrate-resistant acid phosphatase (TRAP) + cells) and tooth movement. Using immunohistochemistry assay we evaluated the RANKL (receptor activator of nuclear factor kappa B ligand) and epidermal growth factor receptor (EGFR) expression. Key findings: The EGF-liposome administration showed an increased tooth movement and osteoclast numbers compared to controls (p<0.05). This was correlated with intense RANKL expression. Both osteoblasts and osteoclasts expressed EGFR. Significance: Local delivery of EGF-liposome stimulates, osteoclastogenesis and tooth movement. (C) 2009 Elsevier Inc. All rights reserved.

Central substance P NK(1) receptors are involved in fever induced by LPS but not by IL-1 beta and CCL3/MIP-1 alpha in rats

Substance P (SP) is a neuropeptide that can modulate inflammatory mediator release through activation of NK(1) receptors (NK(1)R). Some studies have also suggested the involvement of SP in lipopolysaccharide (LPS)-induced fever. However, the precise contribution of this neuropeptide to the pathways activated during fever is unknown. In this study we investigated the effect of a selective NK(1)R antagonist, SR140333B, on the febrile response induced by LPS and cytokines. Our results show that the systemic injection of SR140333B did not modify the fever induced by LPS at a dose that is able to reduce protein extravasation induced by SP in the skin. On the other hand, intracerebroventricular administration of 5R140333B significantly reduced the fever induced by peripheral injection of LPS. These data emphasize an important role for SP in the central nervous system during the febrile response to LPS, and are reinforced by the fact that intracerebroventricular injection of SP also induced fever in a dose-dependent manner in captopril-treated rats. Considering that the febrile response can result from the generation of several endogenous pyrogens, among them interleukin (IL)-1 beta and macrophage inflammatory protein-1 alpha (CCL3/MIP-1 alpha), we also examined the effect of SR140333B on the fever induced by these cytokines which act through prostaglandin-dependent and independent mechanisms, respectively. Surprisingly, SR140333B did not modify the febrile response to IL-1 beta or CCL3/MIP-1 alpha. Altogether these data suggest that the central action of SP is essential for LPS-, but not for IL-1 beta- or CCL3/MIP-1 alpha-induced fever. (C) 2011 Elsevier B.V. All rights reserved.

Prolonged recruitment manoeuvre improves lung function with less ultrastructural damage in experimental mild acute lung injury

The effects of prolonged recruitment manoeuvre (PRM) were compared with sustained inflation (SI) in paraquat-induced mild acute lung injury (ALI) in rats. Twenty-four hours after ALI induction, rats were anesthetized and mechanically ventilated with VT = 6 ml/kg and positive end-expiratory pressure (PEEP) = 5 cmH(2)O for 1 h. SI was performed with an instantaneous pressure increase of 40 cmH(2)O that was sustained for 40 s, while PRM was done by a step-wise increase in positive inspiratory pressure (PIP) of 15-20-25 cmH(2)O above a PEEP of 15 cm H(2)O (maximal PIP = 40 cmH(2)O), with interposed periods of PIP = 10 cmH(2)O above a PEEP = 15 cmH(2)O. Lung static elastance and the amount of alveolar collapse were more reduced with PRM than SI, yielding improved oxygenation. Additionally, tumour necrosis factor-alpha, interleukin-6, interferon-gamma, and type III procollagen mRNA expressions in lung tissue and lung epithelial cell apoptosis decreased more in PRM. In conclusion, PRM improved lung function, with less damage to alveolar epithelium, resulting in reduced pulmonary injury. (C) 2009 Elsevier BLV. All rights reserved.

RANKL is a mediator of bone resorption in idiopathic hypercalciuria

Background and objectives: This study aimed to determine the expression of osteoprotegerin, receptor activator of nuclear factor kappa B ligand, interleukin-la, transforming growth factor-beta, and basic fibroblast growth factor in stone-forming patients with idiopathic hypercalciuria. Design, setting, participants, & measurements: Immunohistochemical analysis was performed in undecalcified bone samples previously obtained from 36 transiliac bone biopsies of patients who had idiopathic hypercalciuria and whose histomorphometry had shown lower bone volume, increased bone resorption, and prolonged mineralization lag time. Results: Bone expression of receptor activator of nuclear factor kappa B ligand and osteoprotegerin was significantly higher in patients with idiopathic hypercalciuria versus control subjects. Transforming growth factor-beta immunostaining was lower in patients with idiopathic hypercalciuria than in control subjects and correlated directly with mineralization surface. Interleukin-la and basic fibroblast growth factor staining did not differ between groups. Receptor activator of nuclear factor kappa B ligand bone expression was significantly higher in patients who had idiopathic hypercalciuria and exhibited higher versus normal bone resorption. Conclusion: A higher expression of receptor activator of nuclear factor kappa B ligand in bone tissue suggests that increased bone resorption in patients with idiopathic hypercalciuria is mediated by receptor activator of nuclear factor kappa B ligand. Osteoprotegerin bone expression might have been secondarily increased in an attempt to counteract the actions of receptor activator of nuclear factor kappa B ligand. The low bone expression of transforming growth factor-beta could contribute to the delayed mineralization found in such patients.

Contractile activity per se induces transcriptional activation of SLC2A4 gene in soleus muscle: involvement of MEF2D, HIF-1a, and TR alpha transcriptional factors

Lima GA, Anhe GF, Giannocco G, Nunes MT, Correa-Giannella ML, Machado UF. Contractile activity per se induces transcriptional activation of SLC2A4 gene in soleus muscle: involvement of MEF2D, HIF-1a, and TR alpha transcriptional factors. Am J Physiol Endocrinol Metab 296: E132-E138, 2009. First published October 28, 2008; doi: 10.1152/ajpendo.90548.2008.-Skeletal muscle is a target tissue for approaches that can improve insulin sensitivity in insulin-resistant states. In muscles, glucose uptake is performed by the GLUT-4 protein, which is encoded by the SLC2A4 gene. SLC2A4 gene expression increases in response to conditions that improve insulin sensitivity, including chronic exercise. However, since chronic exercise improves insulin sensitivity, the increased SLC2A4 gene expression could not be clearly attributed to the muscle contractile activity per se and/or to the improved insulin sensitivity. The present study was designed to investigate the role of contractile activity per se in the regulation of SLC2A4 gene expression as well as in the participation of the transcriptional factors myocyte enhancer factor 2D (MEF2D), hypoxia inducible factor 1a (HIF-1a), and thyroid hormone receptor-alpha (TR alpha). The performed in vitro protocol excluded the interference of metabolic, hormonal, and neural effects. The results showed that, in response to 10 min of electrically induced contraction of soleus muscle, an early 40% increase in GLUT-4 mRNA (30 min) occurred, with a subsequent 65% increase (120 min) in GLUT-4 protein content. EMSA and supershift assays revealed that the stimulus rapidly increased the binding activity of MEF2D, HIF-1a, and TR alpha into the SLC2A4 gene promoter. Furthermore, chromatin immunoprecipitation assay confirmed, in native nucleosome, that contraction induced an approximate fourfold (P < 0.01) increase in MEF2D and HIF-1a-binding activity. In conclusion, muscle contraction per se enhances SLC2A4 gene expression and that involves MEF2D, HIF-1a, and TR alpha transcription factor activation. This finding reinforces the importance of physical activity to improve glycemic homeostasis independently of other additional insulin sensitizer approaches.

Treadmill running protects spinal cord contusion from secondary degeneration

It is known that physical activity triggers changes in the central nervous system Adult rats, trained on treadmills for 4 weeks, and a group of sedentary rats was submitted to contuse moderate spinal cord injury A group of sedentary rats was submitted to a sham operation The trained group continued running on treadmill after lesion for 4 weeks Motor behavior evaluated by BBB score was smaller in the sedentary group compared to the trained rats by 7 days after lesion Computerized activity monitor showed clear-cut differences in spontaneous motor parameters in trained rats only before lesion After surgery, sedentary rats showed changes in motor parameters but not in later periods of analysis Animals were euthanized by 28 days after surgery, and their spinal cords were processed for Nissl staining and immunohistochemistry The number of the remaining neurons and the lesion areal and lesion volume fractions were obtained by stereological method The number of the remaining neurons did not change after training Lesion volume and lesion areal fraction per section were smaller in the trained group Lesion index was more pronounced in the sedentary group Microdensitometric image analysis demonstrated a microglial reaction, astroglial activation, and glial FGF-2 production more pronounced in the spinal cord of sedentary animals GAP-43 was higher in caudal levels of contusion in the sedentary group In conclusion, treadmill running may favor a better functional recovery in the acute period after spinal cord lesion and wound repair processes leading to neuroprotection (C) 2010 Elsevier B V All rights reserved

Neuropeptide Y in Rat Spiral Ganglion Neurons and Inner Hair Cells of Organ of Corti and Effects of a Nontraumatic Acoustic Stimulation

Neuropeptide Y (NPY) is an important neuromodulator found in central and peripheral neurons. NPY was investigated in the peripheral auditory pathway of conventional housed rats and after nontraumatic sound stimulation in order to localize the molecule and also to describe its response to sound stimulus. Rats from the stimulation experiment were housed in monitored sound-proofed rooms. Stimulated animals received sound stimuli (pure tone bursts of 8 kHz, 50 ms duration presented at a rate of 2 per second) at an intensity of 80 dB sound pressure level for 1 hr per day during 7 days. After euthanizing, rat cochleae were processed for one-color immunohistochemistry. The NPY immunoreactivity was detected in inner hair cells (IHC) and also in pillar and Deiters` cells of organ of Corti, and in the spiral ganglion putative type I (1,009 m3) and type II (225 m3) neurons. Outer hair cells (OHC) showed light immunoreaction product. Quantitative microdensitometry showed strong and moderate immunoreactions in IHC and spiral ganglion neurons, respectively, without differences among cochlear turns. One week of acoustic stimulation was not able to induce changes in the NPY immunoreactivity intensity in the IHC of cochlea. However, stimulated rats showed an overall increase in the number of putative type I and type II NPY immunoreactive spiral ganglion neurons with strong, moderate, and weak immunolabeling. Localization and responses of NPY to acoustic stimulus suggest an involvement of the neuropeptide in the neuromodulation of afferent transmission in the rat peripheral auditory pathway.

Methylprednisolone improves lung mechanics and reduces the inflammatory response in pulmonary but not in extrapulmonary mild acute lung injury in mice

Objective: Gorticosteroids have been proposed to be effective in modulating the inflammatory response and pulmonary tissue remodeling in acute lung injury (ALI). We hypothesized that steroid treatment might act differently in models of pulmonary (p) or extrapulmonary (exp) ALI with similar mechanical compromise. Design: Prospective, randomized, controlled experimental study. Setting: University research laboratory. Subjects: One hundred twenty-eight BALB/c mice (20-25 g). Interventions: Mice were divided into six groups. In control animals sterile saline solution was intratracheally (0.05 mL, Cp) or intraperitoneally (0.5 mL, Gexp) injected, whereas ALI animals received Escherichia coli lipopolysaccharide intratracheally (10 mu g, ALIp) or intraperitoneally (125 mu g, ALIexp). Six hours after lipopolysaccharide administration, ALIp and ALlexp animals were further randomized into subgroups receiving saline (0.1 mL intravenously) or methylprednisolone (2 mg/kg intravenously, Mp and Mexp, respectively). Measurements and Main Results: At 24 hrs, lung state elastance, resistive and viscoelastic pressures, lung morphometry, and collagen fiber content were similar in both ALI groups. KC, interieukin-6, and transforming growth factor (TGF)-beta levels in bronchoatveolar lavage fluid, as well as tumor necrosis factor (TNF)-alpha, migration inhibitory factor (MIF), interferon (IFN)-gamma, TGF-beta 1 and TGF-beta 2 messenger RNA expression in lung tissue were higher in ALIp than in ALIexp animals. Methylprednisolone attenuated mechanical and morphometric changes, cytokine levels, and TNF-alpha, MIF, IFN gamma, and TGF-beta 2 messenger RNA expression only in ALIp animals, but prevented any changes in collagen fiber content in both ALI groups. Conclusions. Methylprednisolone is effective to inhibit fibrogenesis independent of the etiology of ALI, but its ability to attenuate inflammatory responses and lung mechanical changes varies according to the cause of ALI.

Oral lesions in lupus erythematosus-cytokines profiles of inflammatory infiltrate

Background: Lupus erythematosus (LE) is a chronic inflammatory disease. Presence of type 1 cytokines in cutaneous discoid lesions suggests that they may be critical for induction, development and maintenance of these manifestations. Type 2 cytokines in combination with local interferon gamma (INF-gamma) are thought to be related to the physiopathology of cutaneous LE. Cytokines profiles are still unknown in oral LE lesions. Materials and Methods: Expression of Th1 and Th2 cytokines (including IL-4, IL-5, IL-6, IL-10, IL-12, tumor necrosis factor alpha (TNF-alpha) and INF-gamma was investigated and compared in 29 biopsies of intra-oral (sun-protected) and labial lesions (sun-exposed) of LE using immunohistochemistry. Results: Inflammatory infiltrate of LE lesions was strongly positive for IFN-gamma (97%) and TNF-alpha (90%), both Th1 type cytokines. Interleukin-10, a Th2 cytokine was also strongly expressed. Other cytokines were only mildly positive. Cytokines patterns were similar in intra-oral (sun-covered) and labial (sun-exposed) LE lesions. Conclusions: Oral LE lesions are associated with both type 1 and type 2 cytokines, characterized by stronger expression of INF-gamma, TNF-alpha and IL-10. These findings suggest that although ultraviolet (UV) light is involved in the induction of LE lesions, mechanisms of lesions formation may be similar in sun-exposed as well as sun-covered areas.

Topical interleukin-1 receptor antagonist inhibits inflammatory cell infiltration into the cornea

Interleukin (IL)-1 alpha and beta are important modulators of many functions of corneal epithelial and stromal cells that occur following injury to the cornea, including the influx of bone marrow-derived inflammatory cells into the stroma attracted by chemokines released from the stroma and epithelium. In this study, we examined the effect of topical soluble IL-1 receptor antagonist on bone marrow-derived cell influx following corneal epithelial scrape injury in a mouse model. C57BL/6 mice underwent corneal epithelial scrape followed by application of IL-1 receptor antagonist (Amgen, Thousand Oaks, CA) at a concentration of 20 mg/ml or vehicle for 24 h prior to immunocytochemical detection of marker CD11b-positive cells into the stroma. In two experiments, topical IL-1 receptor antagonist had a marked effect in blocking cell influx. For example, in experiment 1, topical IL-1 receptor antagonist markedly reduced detectible CD11b-positive cells into the corneal stroma at 24 It after epithelial injury compared with the vehicle control (3.5 +/- 0.5 (standard error of the mean) cells/400x field and 13.9 +/- 1.2 cells/400x field, respectively, p < 0.01). A second experiment with a different observer performing cell counting had the same result. Thus, the data demonstrate conclusively that topical IL-1 receptor antagonist markedly down-regulates CD-11b-positive monocytic cell appearance in the corneal stroma. Topical IL-1 receptor antagonist could be an effective adjuvant for clinical treatment of corneal conditions in which unwanted inflammation has a role in the pathophysiology of the disorder. (c) 2008 Elsevier Ltd. All rights reserved.

CXCL12 rs1801157 polymorphism and expression in peripheral blood from breast cancer patients

The role of chemokines has been extensively analyzed both in cancer risk and tumor progression. Among different cytokines, CXCR4 and its ligand CXCL12 have been recently subjected to a closer examination. The single-nucleotide polymorphism (SNP) rs1801157 (previously known as CXCL12-A/SDF1-3`A) in the CXCL12 gene and the relative expression of mRNA CXCL12 in peripheral blood were assessed in breast cancer patients, since the chemokine CXCL12 and its receptor CXCR4 regulate leukocyte trafficking and many essential biological processes, including tumor growth, angiogenesis and metastasis of different types of tumors. Genotyping was performed by PCR-RFLP (polymerase chain reaction followed by restriction fragment length polymorphism) using MspI restriction enzyme and the expression analyses by quantitative RT-PCR. No difference in GG genotype and allele A carrier frequencies were observed between breast cancer patients and healthy blood donors and nor when CXCL12 mRNA expression was assessed among patients with different tumor stages. However a significant difference was observed when CXCL12 mRNA relative expression was analyzed in breast cancer patients in accordance to the presence or absence of the CXCL12 rs1801157 allele A. Allele A breast cancer patients presented a mRNA CXCL12 expression about 2.1-fold smaller than GG breast cancer patients. Estrogen positive patients presenting CXCL12 allele A presented a significantly lower expression of CXCL12 in peripheral blood (p = 0.039) than GG hormone positive patients. Our findings demonstrated that allele A is associated with low expression of CXCL12 in the peripheral blood from ER-positive breast cancer patients, which suggests implications on breast cancer clinical outcome. (C) 2011 Elsevier Ltd. All rights reserved.

Panicolytic-like effect of BDNF in the rat dorsal periaqueductal grey matter: the role of 5-HT and GABA

A wealth of evidence suggests a role for brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin-related kinase B (TrkB) in the aetiology of depression and in the mode of action of antidepressant drugs. Less clear is the involvement of this neurotrophin in other stress-related pathologies such as anxiety disorders. The dorsal periaqueductal grey matter (DPAG), a midbrain area rich in BDNF and TrkB receptor mRNAs and proteins, has been considered a key structure in the pathophysiology of panic disorder. In this study we investigated the effect of intra-DPAG injection of BDNF in a proposed animal model of panic: the escape response evoked by the electrical stimulation of the same midbrain area. To this end, the intensity of electrical current that needed to be applied to DPAG to evoke escape behaviour was measured before and after microinjection of BDNF. We also assessed whether 5-HT- or GABA-related mechanisms may account for the putative behavioural/autonomic effects of the neurotrophin. BDNF (0.05, 0.1, 0.2 ng) dose-dependently inhibited escape performance, suggesting a panicolytic-like effect. Local microinjection of K252a, an antagonist of TrkB receptors, or bicuculline, a GABA(A) receptor antagonist, blocked this effect. Intra-DPAG administration of WAY-100635 or ketanserin, respectively 5-HT(1A) and 5-HT(2A/2c) receptor antagonists, did not alter BDNF`s effects on escape. Bicuculline also blocked the inhibitory effect of BDNF on mean arterial pressure increase caused by electrical stimulation of DPAG. Therefore, in the DPAG, BDNF-TrkB signalling interacts with the GABAergic system to cause a panicolytic-like effect.

Down-regulation of expression of osteoblast and osteocyte markers in periodontal tissues associated with the spontaneous alveolar bone loss of interleukin-10 knockout mice

The aim of this study was to unravel the mechanisms by which interleukin (IL)-10, a potent pleiotropic cytokine, modulates alveolar bone homeostasis in C57BL/6 wild-type (WT) and IL-10 knockout (IL-10 KO) mice, evaluated at 8, 24, and 48 wk of age. Interleukin-10 KO mice presented significant alveolar bone loss when compared with WT mice, and this was not associated with changes in leukocyte counts or bacterial load. The levels of expression of messenger RNA (mRNA) for tumor necrosis factor-alpha (TNF-alpha), IL-1 beta, IL-6, transforming growth factor-beta (TGF-beta), receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), and matrix metalloproteinase 13 (MMP13) were similar between both strains, whereas a significant decrease of tissue inhibitor of metalloproteinase 1 (TIMP1) mRNA expression was found at 48 wk in IL-10 KO mice. The osteoblast markers core binding factor alpha1 (CBFA1) and type I collagen (COL-I) were expressed at similar levels in both strains, whereas the levels of alkaline phosphatase (ALP) and osteocalcin (OCN), and those of the osteocyte markers phosphate-regulating gene endopeptidases (PHEX) and dentin matrix protein 1 (DMP1) were significantly lower in IL-10 KO mice. Our results demonstrate that the alveolar bone loss in the absence of IL-10 was associated with a reduced expression of osteoblast and osteocyte markers, an effect independent of microbial, inflammatory or bone-resorptive pathways.