Mitochondrial quality control in non-exudative age-related macular degeneration: From molecular mechanisms to structural and functional recovery.

Non-exudative age-related macular degeneration (NE-AMD) is the leading blindness cause in the elderly. Clinical and experimental evidence supports that early alterations in macular retinal pigment epithelium (RPE) mitochondria play a key role in NE-AMD-induced damage. Mitochondrial dynamics (biogenesis, fusion, fission, and mitophagy), which is under the central control of AMP-activated kinase (AMPK), in turn, determines mitochondrial quality. We have developed a NE-AMD model in C57BL/6J mice induced by unilateral superior cervical ganglionectomy (SCGx), which progressively reproduces the disease hallmarks circumscribed to the temporal region of the RPE/outer retina that exhibits several characteristics of the human macula. In this work we have studied RPE mitochondrial structure, dynamics, function, and AMPK role on these parameters' regulation at the nasal and temporal RPE from control eyes and at an early stage of experimental NE-AMD (i.e., 4 weeks post-SCGx). Although RPE mitochondrial mass was preserved, their function, which was higher at the temporal than at the nasal RPE in control eyes, was significantly decreased at 4 weeks post-SCGx at the same region. Mitochondria were bigger, more elongated, and with denser cristae at the temporal RPE from control eyes. Exclusively at the temporal RPE, SCGx severely affected mitochondrial morphology and dynamics, together with the levels of phosphorylated AMPK (p-AMPK). AMPK activation with metformin restored RPE p-AMPK levels, and mitochondrial dynamics, structure, and function at 4 weeks post-SCGx, as well as visual function and RPE/outer retina structure at 10 weeks post-SCGx. These results demonstrate a key role of the temporal RPE mitochondrial homeostasis as an early target for NE-AMD-induced damage, and that pharmacological AMPK activation could preserve mitochondrial morphology, dynamics, and function, and, consequently, avoid the functional and structural damage induced by NE-AMD.

Clinical relevance of stem cells in lung cancer.

Lung cancer is the major cause of cancer-related deaths worldwide, it has one of the lowest 5-year survival rate, mainly because it is diagnosed in the late stage of the disease. Lung cancer is classified into two groups, small cell lung cancer (SCLC) and non-SCLC (NSCLC). In turn, NSCLC is categorized into three distinct cell subtypes: Adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. NSCLC is the most common lung cancer, accounting for 85% of all lung cancers. Treatment for lung cancer is linked to the cell type and stage of the disease, involving chemotherapy, radiation therapy, and surgery. Despite improvements in therapeutic treatments, lung cancer patients show high rates of recurrence, metastasis, and resistance to chemotherapy. Lung stem cells (SCs) are undifferentiated cells capable of self-renewal and proliferation, are resistant to chemotherapy and radiotherapy and, due to their properties, could be involved in the development and progression of lung cancer. The presence of SCs in the lung tissue could be the reason why lung cancer is difficult to treat. The identification of lung cancer stem cells biomarkers is of interest for precision medicine using new therapeutic agents directed against these cell populations. In this review, we present the current knowledge on lung SCs and discuss their functional role in the initiation and progression of lung cancer, as well as their role in tumor resistance to chemotherapy.

Enriched environment and visual stimuli protect the retinal pigment epithelium and photoreceptors in a mouse model of non-exudative age-related macular degeneration.

Non-exudative age-related macular degeneration (NE-AMD), the main cause of blindness in people above 50 years old, lacks effective treatments at the moment. We have developed a new NE-AMD model through unilateral superior cervical ganglionectomy (SCGx), which elicits the disease main features in C57Bl/6J mice. The involvement of oxidative stress in the damage induced by NE-AMD to the retinal pigment epithelium (RPE) and outer retina has been strongly supported by evidence. We analysed the effect of enriched environment (EE) and visual stimulation (VS) in the RPE/outer retina damage within experimental NE-AMD. Exposure to EE starting 48 h post-SCGx, which had no effect on the choriocapillaris ubiquitous thickness increase, protected visual functions, prevented the thickness increase of the Bruch's membrane, and the loss of the melanin of the RPE, number of melanosomes, and retinoid isomerohydrolase (RPE65) immunoreactivity, as well as the ultrastructural damage of the RPE and photoreceptors, exclusively circumscribed to the central temporal (but not nasal) region, induced by experimental NE-AMD. EE also prevented the increase in outer retina/RPE oxidative stress markers and decrease in mitochondrial mass at 6 weeks post-SCGx. Moreover, EE increased RPE and retinal brain-derived neurotrophic factor (BDNF) levels, particularly in Müller cells. When EE exposure was delayed (dEE), starting at 4 weeks post-SCGx, it restored visual functions, reversed the RPE melanin content and RPE65-immunoreactivity decrease. Exposing animals to VS protected visual functions and prevented the decrease in RPE melanin content and RPE65 immunoreactivity. These findings suggest that EE housing and VS could become an NE-AMD promising therapeutic strategy.

Secretory Leukocyte Proteinase Inhibitor Protects Acute Kidney Injury Through Immune and Non-Immune Pathways.

ABSTRACT: Acute kidney injury (AKI) is characterized by rapid loss of excretory function and is the clinical manifestation of several disorders affecting the kidney. The aim of the present study was to investigate the mechanism of action of Secretory Leukocyte Proteinase Inhibitor (SLPI) that protects the kidneys form AKI. In vivo and in vitro experiments were performed to assess the effect of SLPI on kidney injury. Animal models of kidney injury was generated by 40 min obstruction of kidney artery and vein (ischemia-reperfusion injury model) or daily administration of 60 mg/kg/day of gentamicine for 5 day (gentamicin-associated AKI model). For in vitro assessment, human renal epithelium HK-2 cells were cultured under serum starvation conditions or with tacrolimus. The administration of SLPI (250 µg/kg, i.p.) reduced elevated plasma creatinine and blood urea nitrogen levels, tissue myeloperoxidase content, and acute tubular necrosis induced by kidney damage. Furthermore, SLPI treatment reduced CD86, CD68, CD14, CCL2, TNFα, and IL-10 transcripts in kidney biopsies. To further analyze a direct effect of SLPI on renal epithelial cells, HK-2 cells from human renal epithelium were cultured under serum starvation conditions or with tacrolimus. Both conditions induced apoptosis of HK-2 cells which was reduced when SLPI was present in the culture medium. Furthermore, SLPI favored the proliferation and migration of HK-2 cells. An analysis of the gene profiles of HK-2 cells treated with calcineurin inhibitors affected inflammatory and non-inflammatory pathways that were reversed by SLPI. Among them, SLPI down modulated the expression of CCL2, SLC5A3, and BECN1 but up-regulated the expression of TLR4, ATF4, ATF6, HSP90B, BBC3 SLC2A1, and TNFRSF10B. Overall, these results suggest that SLPI, in addition to its activity on immune cells, may directly target tubular epithelial cells of the kidney to mediate the nephroprotective activity in AKI.

Melatonin protects the retina from experimental nonexudative age-related macular degeneration in mice.

Nonexudative age-related macular degeneration (NE-AMD) represents the leading cause of blindness in the elderly. Currently, there are no available treatments for NE-AMD. We have developed a NE-AMD model induced by superior cervical ganglionectomy (SCGx) in C57BL/6J mice, which reproduces the disease hallmarks. Several lines of evidence strongly support the involvement of oxidative stress in NE-AMD-induced retinal pigment epithelium (RPE) and outer retina damage. Melatonin is a proven and safe antioxidant. Our aim was analysing the effect of melatonin in the RPE/outer retina damage within experimental NE-AMD. The treatment with melatonin starting 48 h after SCGx, which had no effect on the ubiquitous choriocapillaris widening, protected visual functions and avoided Bruch´s membrane thickening, RPE melanin content, melanosome number loss, retinoid isomerohydrolase (RPE65)-immunoreactivity decrease, and RPE and hotoreceptor ultrastructural damage induced within experimental NE-AMD exclusively located at the central temporal (but not nasal) region. Melatonin also prevented the increase in outer retina/RPE oxidative stress markers and a decrease in mitochondrial mass at 6 weeks post-SCGx. Moreover, when the treatment with melatonin started at 4 weeks post-SCGx, it restored visual functions and reversed the decrease in RPE melanin content and RPE65-immunoreactivity. These findings suggest that melatonin could become a promising safe therapeutic strategy for NE-AMD.

Oxidative stress damage circumscribed to the central temporal retinal pigment epithelium in early experimental non-exudative age-related macular degeneration.

Non-exudative age-related macular degeneration (NE-AMD) represents the leading cause of blindness in the elderly. The macular retinal pigment epithelium (RPE) lies in a high oxidative environment because its high metabolic demand, mitochondria concentration, reactive oxygen species levels, and macular blood flow. It has been suggested that oxidative stress-induced damage to the RPE plays a key role in NE-AMD pathogenesis. The fact that the disease limits to the macular region raises the question as to why this area is particularly susceptible. We have developed a NE-AMD model induced by superior cervical ganglionectomy (SCGx) in C57BL/6J mice, which reproduces the disease hallmarks exclusively circumscribed to the temporal region of the RPE/outer retina. The aim of this work was analyzing RPE regional differences that could explain AMD localized susceptibility. Lower melanin content, thicker basal infoldings, higher mitochondrial mass, and higher levels of antioxidant enzymes, were found in the temporal RPE compared with the nasal region. Moreover, SCGx induced a decrease in the antioxidant system, and in mitochondria mass, as well as an increase in mitochondria superoxide, lipid peroxidation products, nuclear Nrf2 and heme oxygenase-1 levels, and in the occurrence of damaged mitochondria exclusively at the temporal RPE. These findings suggest that despite the well-known differences between the human and mouse retina, it might not be NE-AMD pathophysiology which conditions the localization of the disease, but the macular RPE histologic and metabolic specific attributes that make it more susceptible to choroid alterations leading initially to a localized RPE dysfunction/damage, and secondarily to macular degeneration.

Superior cervical gangliectomy induces non-exudative age-related macular degeneration in mice.

Non-exudative age-related macular degeneration, a prevalent cause of blindness, is a progressive and degenerative disease characterized by alterations in Bruch's membrane, retinal pigment epithelium, and photoreceptors exclusively localized in the macula. Although experimental murine models exist, the vast majority take a long time to develop retinal alterations and, in general, these alterations are ubiquitous, with many resulting from non-eye-specific genetic manipulations; additionally, most do not always reproduce the hallmarks of human age-related macular degeneration. Choroid vessels receive sympathetic innervation from the superior cervical ganglion, which, together with the parasympathetic system, regulates blood flow into the choroid. Choroid blood flow changes have been involved in age-related macular degeneration development and progression. At present, no experimental models take this factor into account. The aim of this work was to analyze the effect of superior cervical gangliectomy (also known as ganglionectomy) on the choroid, Bruch's membrane, retinal pigment epithelium and retina. Adult male C57BL/6J mice underwent unilateral superior cervical gangliectomy and a contralateral sham procedure. Although superior cervical gangliectomy induced ubiquitous choroid and choriocapillaris changes, it induced Bruch's membrane thickening, loss of retinal pigment epithelium melanin content and retinoid isomerohydrolase, the appearance of drusen-like deposits, and retinal pigment epithelium and photoreceptor atrophy, exclusively localized in the temporal side. Moreover, superior cervical gangliectomy provoked a localized increase in retinal pigment epithelium and photoreceptor apoptosis, and a decline in photoreceptor electroretinographic function. Therefore, superior cervical gangliectomy recapitulated the main features of human non-exudative age-related macular degeneration, and could become a new experimental model of dry age-related macular degeneration, and a useful platform for developing new therapies.

Origins of the sympathetic innervation to the nasal-associated lymphoid tissue (NALT): an anatomical substrate for a neuroimmune connection.

The participation of sympathetic nerve fibers in the innervation of the nasal-associated lymphoid tissues (NALT) was investigated in hamsters. Vesicular monoamine transporter 2 (VMAT2), an established sympathetic marker, is expressed in all neurons of superior cervical ganglia (SCG). In addition, VMAT2 -immunoreactive nerve fibers were localized in the NALT as well as in adjacent anatomical structures of the upper respiratory tract. Unilateral surgical ablation of the SCG abolished VMAT2 innervation patterns ipsilaterally while the contra lateral side is unaffected. These results provide the anatomical substrate for a neuroimmune connection in the NALT.

IL-17 and IFN-γ expression in lymphocytes from patients with active tuberculosis correlates with the severity of the disease.

Th1 lymphocytes are crucial in the immune response against Mycobacterium tuberculosis. Nevertheless, IFN-γ alone is not sufficient in the complete eradication of the bacteria, suggesting that other cytokines might be required for pathogen removal. Th17 cells have been associated with M. tuberculosis infection, but the role of IL-17-producing cells in human TB remains to be understood. Therefore, we investigated the induction and regulation of IFN-γ and IL-17 during the active disease. TB patients were classified as High and Low Responder individuals according to their T cell responses against the antigen, and cytokine expression upon M. tuberculosis stimulation was investigated in peripheral blood and pleural fluid. Afterwards, the potential correlation among the proportions of cytokine-producing cells and clinical parameters was analyzed. In TB patients, M. tuberculosis induced IFN-γ and IL-17, but in comparison with BCG-vaccinated healthy donors, IFN-γ results were reduced significantly, and IL-17 was markedly augmented. Moreover, the main source of IL-17 was represented by CD4(+)IFN-γ(+)IL-17(+) lymphocytes, a Th1/Th17 subset regulated by IFN-γ. Interestingly, the ratio of antigen-expanded CD4(+)IFN-γ(+)IL-17(+) lymphocytes, in peripheral blood and pleural fluid from TB patients, was correlated directly with clinical parameters associated with disease severity. Indeed, the highest proportion of CD4(+)IFN-γ(+)IL-17(+) cells was detected in Low Responder TB patients, individuals displaying severe pulmonary lesions, and longest length of disease evolution. Taken together, the present findings suggest that analysis of the expansion of CD4(+)IFN-γ(+)IL-17(+) T lymphocytes in peripheral blood of TB patients might be used as an indicator of the clinical outcome in active TB.

A standardized surgical technique for rat superior cervical ganglionectomy.

Superior cervical ganglionectomy (SCGx) is a valuable microsurgical model to study the role of the sympathetic nervous system in a vast array of physiological and pathological processes, including homeostatic regulation, circadian biology and the dynamics of neuronal dysfunction and recovery after injury. Despite having several experimental applications in the rat, a thorough description of a standardized procedure has never been published. Here, we provide a brief review of the principal features and experimental uses of the SCGx, the surgical anatomy of the neck and sympathetic cervical chain, and a step-by-step description of how to consistently remove the superior cervical ganglia through the omohyoid muscle or the carotid triangle. Furthermore, we suggest procedures and precautions to be taken during and after surgery to optimize results and describe tools to validate surgical success. We expect that the following standardized and optimized protocol will allow researchers to organize knowledge into a cohesive framework in those areas where the SCGx is applied.

Effects of superior cervical ganglionectomy on body temperature and on the lipopolysaccharide-induced febrile response in rats.

The involvement of the cervical sympathetic ganglia (SCG) on body temperature and during the occurrence of the induced febrile response was investigated in rats. Bilateral superior cervical gaglionectomy (SCGx) attenuated the daily dark-phase temperature compared to that of the sham-operated rats during the first 2 days post surgery. Body temperatures returned to pre-surgery levels by Day-3. Ten days after surgery, a febrile response was induced by lipopolysaccharide (LPS) immune challenge. SCGx significantly blunted the LPS-induced febrile response. These data suggest that obliteration of the cervical sympathetic peripheral innervation impairs the capability to produce an induced febrile response.

Neutrophil elastase converts human immature dendritic cells into transforming growth factor-beta1-secreting cells and reduces allostimulatory ability.

During microbial infection, neutrophils (polymorphonuclear leukocytes; PMNs) activate dendritic cells (DCs). However, early reports illustrated that neutrophil-derived mediators may suppress responses to mitogens. In the present study, we investigated the mechanism used by PMNs to modulate the immunostimulatory ability of DCs. Autologous syngeneic PMNs decreased T-cell proliferation induced by allogeneic DCs. Culture supernatant (CS) derived from PMNs also decreased allostimulation ability of immature DCs and increased the expression of transforming growth factor (TGF)-beta1 on DCs. A TGF-beta1 monoclonal antibody, a CD40 monoclonal antibody, or a serine protease inhibitor reversed the effect of PMN CS on DC allostimulatory ability. Furthermore, elastase reproduced the inhibitory effect of PMN CS on DC allostimulatory ability and the TGF-beta1 production. The role of elastase was confirmed by examining PMN CS from two patients with cyclic neutropenia, a disease due to mutations in the neutrophil elastase gene. These PMN CS samples had reduced elastase activity and were unable to increase DC TGF-beta1 production. Moreover, elastase and PMN CS induced IkappaBalpha degradation in DCs. We conclude that PMNs decrease DC allostimulatory ability via production of elastase leading to a switch of immature DCs into TGF-beta1-secreting cells.

Distribution and localization patterns of estrogen receptor-beta and insulin-like growth factor-1 receptors in neurons and glial cells of the female rat substantia nigra: localization of ERbeta and IGF-1R in substantia nigra.

Although several studies have focused on the neuroprotective effects of estrogen (E2) on stroke, there have been tantalizing reports on the potential neuroprotective role of E2 in degenerative neuronal diseases such as Alzheimer's and Parkinson's (PD). In animal models of PD, E2 protects the nigrostriatal dopaminergic (DA) system against neurotoxins. However, little is known about the cellular and molecular mechanism(s) involved by which E2 elicits its neuroprotective effects on the nigrostriatal DA system. A preferred mechanism for neuroprotection is the interaction of E2 with specific neuroprotective growth factors and receptors. One such neuroprotective factor/receptor system is insulin-like growth factor-1 (IGF-1). E2 neuroprotective effects in the substantia nigra (SN) DA system have been shown to be dependent on IGF-1. To determine whether E2 also interacts with the IGF-1 receptor (IGF-1R) and to determine the cellular localization of estrogen receptor (ER) and IGF-1R, we compared the distribution of ER and IGF-1R in the SN. Stereological measurements revealed that 40% of the subpopulation of tyrosine hydroxylase-immunoreactive (TH-ir) SN pars compacta (SNpc) DA neurons are immunoreactive for estrogen receptor-beta (ERbeta). No immunolabeling for ERalpha was observed. In situ hybridization and immunocytochemistry studies confirmed the expression of IGF-1R mRNA and revealed that almost all TH-ir SNpc DA neurons were immunoreactive for IGF-1R, respectively. Moreover, one-third of glial fibrillary acidic protein (GFAP-ir) cells in the SN were ERbeta-ir, and 67% of GFAP-ir cells expressed IGF-1R-ir. Therefore, the localization of ERbeta and IGF-1R on SNpc DA neurons and astrocytes suggests a modulatory role of E2 on IGF-1R, and this modulation may affect neuroprotection.

Site-specific estrogen and progestin regulation of orphanin FQ/nociceptin and nociceptin opioid receptor mRNA expression in the female rat limbic hypothalamic system.

The distributions of orphanin FQ (OFQ/N; also known as nociceptin) and its cognate receptor, opioid receptor-like receptor-1 (NOP), overlap steroid-responsive regions throughout reproductive circuits of the limbic system and hypothalamus. For example, in the ventromedial nucleus of the hypothalamus (VMH), OFQ/N facilitates lordosis in female rats through estrogen and progesterone regulation of nociceptin activity. We studied estrogen and progesterone regulation of OFQ/N and NOP mRNA expression in limbic-hypothalamic reproductive circuits. Ovariectomized rats were treated with 17beta-estradiol-benzoate (2 microg) and 26 hours later with oil or progesterone (500 microg) and were killed 30 hours after initial treatment. Alternate brain sections were processed for OFQ/N or NOP mRNA in situ hybridization. High levels of hybridization for NOP and OFQ/N and overlapping distributions were observed throughout the limbic hypothalamic reproductive circuits; however, in VMH, only NOP expression was observed. Estrogen treatment increased NOP mRNA expression in anteroventral periventricular nucleus (AVPV), median preoptic nucleus, and VMH. Subsequent progesterone treatment did not alter estrogen-induced expression of NOP mRNA in VMH or median preoptic nucleus but reduced expression in the AVPV. OFQ/N mRNA levels were also regulated by steroids. In the caudal part of the posterodorsal medial amygdala, estrogen increased OFQ/N mRNA levels, and progesterone did not alter this increase, whereas, in the medial part of the medial preoptic nucleus, estrogen and progesterone were needed to increase OFQ/N mRNA levels. Steroid regulation of OFQ/N and NOP in the medial preoptic nucleus and VMH is consistent with emerging data indicating that this opioid system regulates female reproduction.

Differential effects of alcohol consumption and withdrawal on circadian temperature and activity rhythms in Sprague-Dawley, Lewis, and Fischer male and female rats.

BACKGROUND: Hypothalamic synthesis and secretion of corticotropin-releasing hormone (CRH), a putative mediator of various behavioral and physiological responses to ethanol (EtOH), is defective in inbred Lewis (LEW) rats in comparison with their genetically related inbred Fischer 344 (F344) and outbred Sprague-Dawley (S-D) strains. We aimed to characterize the effects of continuous EtOH consumption and withdrawal on circadian patterns of body temperature and spontaneous locomotor activity in males and females of these 3 strains. METHODS: Adult LEW, F344, and S-D males and randomly cycling females were fed an EtOH-containing liquid diet or the control (pair-fed or lab chow and water) diet for 14 days. Biotelemetric body temperature data for the last 3 days of EtOH diet feeding and the first 3 days of withdrawal were subjected to cosinor analysis of the circadian rhythm parameters of midline-estimating statistic of rhythm (MESOR), amplitude, and acrophase. Mean dark-phase activity during these periods was also computed. RESULTS: In the control diet condition, the MESORs and amplitudes of LEW males were lower than those of F344 males. MESORs of rhythms of LEW females were lower than those of both F344 and S-D females. Ethanol consumption caused hypothermia with reduced MESORs and amplitudes of LEW and F344 males and amplitudes of F344 and S-D females. Upon withdrawal, MESORs of the males increased during each day as the amplitudes decreased, reflective of their initial withdrawal-induced dark-phase hypothermia, which was most pronounced in the LEW males, followed by light-phase hyperthermia. MESORs of females were not affected by withdrawal; their amplitudes were differentially affected. Acrophase of LEW males shifted from dark to light on the first day of withdrawal. All rats responded to EtOH exposure with a reduction of dark-phase spontaneous locomotor activity and an immediate increase upon withdrawal. CONCLUSIONS: Body temperature rhythms of the males were generally more affected by EtOH consumption and withdrawal than the females; within each sex, LEW and F344 rats differed significantly. The specific hormonal factors that mediate the differential temperature responses remain to be defined.

The febrile response to intraperitoneal lipopolysaccharide: strain and gender differences in rats.

The acute-phase febrile responses of the inbred Lewis (LEW) and Fischer 344 (F344) rat strains and their parent Sprague-Dawley (S-D) strain to immune challenge with lipopolysaccharide (LPS) were compared. LEW and S-D males and females displayed a biphasic febrile response with a markedly attenuated second phase in F344 rats. At 2 h after LPS (50 microg/kg), corticosterone was significantly higher in F344 than in LEW rats, but serum interleukin-1beta was higher only in F344 than LEW males. These data suggest that the greater LPS-induced corticosterone response of F344 rats mediates differences between febrile responses of F344 and LEW males and females.

Plasticity of IL-2 and IL-2 receptor chains in rat lymphoid tissues in situ after stimulation with staphylococcal enterotoxin A.

Although the effects of mitogens on the synthesis of interleukin-2 (IL-2) and IL-2 receptor (IL-2r) have been described, a detailed in situ analysis of the spatio-temporal changes of the expression of the IL-2 gene and the three IL-2r components in lymphoid tissues is still missing. Therefore, we analyzed the IL-2 and IL-2r expression after a staphylococcal enterotoxin A (SEA)-induced T cell activation on a cellular and anatomical basis in the Wistar rat. SEA caused a rapid induction of IL-2 mRNA in T cells of spleen, lymph node, and thymus, followed by the appearance of high systemic IL-2 serum levels (5 ng/ml), and a significant increase of CD25 on CD4+ and CD8+ lymphocytes. The histotopographic analysis of the IL-2r chains revealed a strong upregulation of IL-2r alpha (alpha) and IL-2r beta (beta) mRNAs in similar T cell specific compartments of spleen, lymph node, and thymus as seen for IL-2 mRNA. The abundant constitutive expression of IL-2r gamma (gamma) mRNA was unaffected by SEA. The parallel upregulation of IL-2, IL-2ralpha, and beta chains in conjunction with the continuous presence of the IL-2rgamma chain predominantly in T cell regions of immune organs suggests that the biological effects of IL-2 are essentially limited to T cells, at least after superantigen stimulation.

Effects of glossopharyngeal nerve transection on central and peripheral cytokines and serum corticosterone induced by localized inflammation.

Bilateral transection of the glossopharyngeal nerves (GLOx) disrupts the immune-to-brain communication from the posterior oral cavity. The current report tested whether this effect is due to the afferent (sensory) or efferent (parasympathetic motor) components of the nerve. Injection of lipopolysaccharide (LPS) into the soft palate (ISP) of GLOx or sham-operated (SHAM) rats increased the circulating levels of interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1ra) and corticosterone (CORT), as well the hypothalamic content of IL-1beta; no difference in circulating levels and hypothalamic content was found between GLOx and SHAM at 2 and 4.5 h after LPS injection. These results indicate that glossopharyngeal neural efferents do not mediate the effects of GLOx on the immune-to-brain communication.

Site-specific decrease of progesterone receptor mRNA expression in the hypothalamus of middle-aged persistently estrus rats.

Middle-aged females gradually become acyclic and spontaneously develop a persistently estrus (PE) state. PE rats, acyclic for 30 days (early PE), are unresponsive to the positive feedback action of estrogen, but respond to a progesterone challenge with a luteinizing hormone (LH) surge and ovulation; unlike long-term PE rats, acyclic for 90 days, neither estrogen nor estrogen plus progesterone will elicit an LH surge [10th International Congress of Endocrinology, San Francisco, P3 (1996) 1061]. We hypothesize that the PE state may develop due to a diminished level of estrogen-induced progesterone receptor (PR) expression in the hypothalamus that prevents progesterone from stimulating LH regulating circuits. To test this hypothesis, PR mRNA levels were measured in hypothalamic regions of young, proestrus (2-3 months of age), early PE (10-12 months) and long-term PE (13-15 months) rats. The anteroventral periventricular nucleus (AVPV), an important regulatory site of the LH surge, had decreased PR mRNA levels in early and long-term PE rats compared with proestrus rats. However, PR mRNA levels were reduced only in long-term PE rats in the ventromedial nucleus (VMH) and arcuate nucleus (ARH). In the medial preoptic nucleus (MPN), levels of PR mRNA did not change. A previous report showed that exogenous progesterone stimulates an LH surge in young and early PE animals, indicating that the expression of PR mRNA demonstrated in this study is sufficient to mediate progesterone facilitation of the LH surge in early PE rats. In acyclic, long-term PE rats, diminished estrogen-induced expression of progesterone receptors is correlated with a previously shown inability to respond to exogenous progesterone.

Maternal adrenalectomy abrogates the effect of fetal alcohol exposure on the interleukin-1beta-induced febrile response: gender differences.

Fetal alcohol exposure (FAE) has been shown to blunt the febrile component of the primary host-defense response to infection induced experimentally by systemic administration of interleukin (IL)-1beta. Given that maternal adrenalectomy (ADX) can prevent various postnatal effects of FAE, the present experiments were designed to determine whether maternal ADX would prevent the blunted IL-1beta-induced febrile response of fetal alcohol-exposed offspring and whether the effects of maternal ADX would be gender related. Timed-pregnant rats underwent ADX or were sham-operated on gestation day (GD) 7, or remained intact (without any surgery), and were fed ethanol-containing (E) or pair-fed (PF) liquid diets or normal (N) rat chow and water from GD 8 to GD 21. As adults, male and female E, PF and N offspring were injected with saline on day 1 and with IL-1beta (2 microg/kg, i.p.) on day 2 at 09.00 h and the body temperature was recorded biotelemetrically for 8.5 h. IL-1beta produced significantly lower febrile responses in female than in male offspring of intact dams, irrespective of prenatal diet. Furthermore, prenatal surgical stress differentially affected the IL-1beta-induced febrile response of male and female normally fed offspring. Additionally, in both male and female offspring of intact dams, FAE significantly attenuated the IL-1beta-induced febrile response. In males, FAE also attenuated the febrile response in the offspring of maternal sham-operated dams, and this effect was completely reversed by maternal ADX. In females, both maternal sham surgery and ADX reversed the effect of FAE on the febrile response. These findings suggest that maternal adrenal mediators are essential for the long-term effect of FAE on the febrile response in male offspring. In females, early prenatal surgical stress is sufficient to reverse the effects of FAE, possibly via adrenal-independent mechanisms that affect the thermoregulatory system.