Th1 lymphocytes are crucial in the immune response against Mycobacterium tuberculosis. Nevertheless, IFN-␥ 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-␥ 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-␥ and IL-17, but in comparison with BCG-vaccinated healthy donors, IFN-␥ results were reduced significantly, and IL-17 was markedly augmented. Moreover, the main source of IL-17 was represented by CD4 ϩ IFN-␥ ϩ IL-17 ϩ lymphocytes, a Th1/Th17 subset regulated by IFN-␥. Interestingly, the ratio of antigen-expanded CD4 ϩ IFN-␥ ϩ IL-17 ϩ 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 ϩ IFN-␥ ϩ IL-17 ϩ cells was detected in Low Responder TB patients, individuals displaying se-vere pulmonary lesions, and longest length of disease evolution. Taken together, the present findings suggest that analysis of the expansion of CD4 ϩ IFN-␥ ϩ IL-17 ϩ T lymphocytes in peripheral blood of TB patients might be used as an indicator of the clinical outcome in active TB.
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.
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.
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.
In order to assess the effect of pinealectomy (Px) on the diurnal rhythmicity of gamma-aminobutyric acid(GABA) high affinity binding to cerebral cortex membranes, groups of intact, Px or sham Px rats (subjected to surgery 15 days earlier) were killed at six different time intervals during the 24-hour cycle. GABA binding was estimated by Scatchard analysis of 3H-GABA binding to cerebral cortex membranes prepared from individual brains; only one type of binding site with dissociation constant (KD) about 20–50 nM and site number (Bmax) about 200–500 fmol/mg protein was apparent in the assay conditions employed. In intact and sham Px rats Bmax attained minimal values at night and increased during daylight. Px increased generally Bmax and disrupted its normal diurnal rhythmicity, a peak in Bmaa being observed at midnight. A significant decrease of GABA high affinity binding affinity was detected at morning hours in intact rats and at late scotophase and morning hours in Px and sham Px rats. Bmax of GABA high affinity binding in Px rats attained maximal values by 5–10 days after surgery and decreased somewhat 5 days later. Sham Px rats exhibited a transient increase in Bmax up to 10 days after surgery, returning to normal values by the 15th day. Superior cervical ganglionectomy increased binding affinity up to 15 days after surgery without affecting Bmax. The minimal melatonin effective dose to counteract Px-induced increase of GABA high affinity binding was 25 µg/kg body weight when given 3 h before sacrifice. Melatonin activity on GABA binding did not depend upon a direct effect on the binding sites, as shown in vitro. These results suggest a link between pineal function, melatonin secretion and GABA receptor activity in rats.
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