Sequences of Alterations in Inflammation and Autophagy Processes in Rd1 Mice.

(1) Background: the aim of this work was to study microglia and autophagy alterations in a one retinitis pigmentosa (RP) model at different stages of the disease (when rods are dying and later, when there are almost no rods, and cones are the cells that die. (2) Methods: rd1 mice were used and retinas obtained at postnatal days (PN) 11, 17, 28, 35, and 42. Iba1 (ionized calcium-binding adapter molecule 1) was the protein selected to study microglial changes. The macroautophagy markers Beclin-1, Atg5, Atg7, microtubule-associated protein light chain 3 (LC3), and lysosomal-associated membrane protein 2 (LAMP2) (involved in chaperone-mediated autophagy (CMA)) were determined. (3) Results: the expression of Iba1 was increased in rd1 retinas compared to the control group at PN17 (after the period of maximum rod death), PN28 (at the beginning of the period of cone death), and PN42. The number of activated (ameboid) microglial cells increased in the early ages of the retinal degeneration and the deactivated forms (branched cells) in more advanced ages. The macroautophagy markers Atg5 at PN11, Atg7 and LC3II at PN17, and Atg7 again at PN28 were decreased in rd1 retinas. At PN35 and PN42, the results reveal alterations in LAMP2A, a marker of CMA in the retina of rd1 mice. (4) Conclusions: we can conclude that during the early phases of retinal degeneration in the rd1 mouse, there is an alteration in microglia and a decrease in the macroautophagy cycle. Subsequently, the CMA is decreased and later on appears activated as a compensatory mechanism.

Time-Course Changes in Oxidative Stress and Inflammation in the Retinas of rds Mice: A Retinitis Pigmentosa Model.

(1) Background: Retinitis pigmentosa (RP) is characterized by progressive photoreceptor death. A Prph2Rd2 or an rds mouse is an RP model that closely reflects human RP. The objective of this study was to investigate the relationship of rod and cone death with oxidative stress and inflammation in rds mice. (2) Methods: The retinas of control and rds mice on postnatal days (PN) 11, 17, 21, 28, 35, and 42 were used. Oxidative damage to macromolecules, glutathione (GSH and GSSG), GSH synthesis enzymes, glial fibrillar acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba1), and cluster of differentiation 68 (CD68) was studied. (3) Results: The time sequence of oxidative stress and inflammation changes in rds mice occurs as follows: (i) At PN11, there is a small increase in photoreceptor death and in the microglial cells; (ii) at PN17, damage to the macromolecules is observed; (iii) at PN21, the maximum photoreceptor death rate is detected and there is an increase in GSH-GSSG and GFAP; (iv) at PN21, the microglial cells are activated; and(v) at PN28, there is a decrease in GSH synthesis enzymes. (4) Conclusions: These findings contribute to the understanding of RP physiopathology and help us to understand whether oxidative stress and inflammation are therapeutic targets. These findings contribute to our understanding that, in RP, oxidative stress and inflammation evolution and their relationship are time-dependent. In this sense, it is important to highlight that both processes are potential therapeutic targets in this disease.

Sulforaphane Modulates the Inflammation and Delays Neurodegeneration on a Retinitis Pigmentosa Mice Model.

The term retinitis pigmentosa (RP) describes a large group of hereditary retinopathies. From a cellular view, retinal degeneration is prompted by an initial death of rods, followed later by cone degeneration. This cellular progressive degeneration is translated clinically in tunnel vision, which evolves to complete blindness. The mechanism underlying the photoreceptor degeneration is unknown, but several mechanisms have been pointed out as main co-stars, inflammation being one of the most relevant. Retinal inflammation is characterized by proliferation, migration, and morphological changes in glial cells, in both microglia and Müller cells, as well as the increase in the expression of inflammatory mediators. Retinal inflammation has been reported in several animal models and clinical cases of RP, but the specific role that inflammation plays in the pathology evolution remains uncertain. Sulforaphane (SFN) is an antioxidant natural compound that has shown anti-inflammatory properties, including the modulation of glial cells activation. The present work explores the effects of SFN on retinal degeneration and inflammation, analyzing the modulation of glial cells in the RP rd10 mice model. A daily dose of 20 mg/kg of sulforaphane was administered intraperitoneally to control (C57BL/6J wild type) and rd10 (Pde6brd10) mice, from postnatal day 14 to day 20. On postnatal day 21, euthanasia was performed. Histological retina samples were used to assess cellular degeneration, Müller cells, and microglia activation. SFN administration delayed the loss of photoreceptors. It also ameliorated the characteristic reactive gliosis, assessed by retinal GFAP expression. Moreover, sulforaphane treatment regulated the microglia activation state, inducing changes in the microglia morphology, migration, and expression through the retina. In addition, SFN modulated the expression of the interleukins 1ß, 4, Ym1, and arginase inflammatory mediators. Surprisingly, M2 polarization marker expression was increased at P21 and was reduced by SFN treatment. To summarize, SFN administration reduced retinal neurodegeneration and modified the inflammatory profile of RP, which may contribute to the SFN neuroprotective effect.

Thioredoxin Delays Photoreceptor Degeneration, Oxidative and Inflammation Alterations in Retinitis Pigmentosa.

Retinitis pigmentosa (RP) is an inherited ocular disorder with no effective treatment. RP onset and progression trigger a cascade of retinal disorders that lead to the death of photoreceptors. After photoreceptors death, neuronal, glial and vascular remodeling can be observed in the retina. The purpose of this study was to study if thioredoxin (TRX) administration is able to decrease photoreceptor death in an animal model of RP (rd1 mouse), but also if it is able to modulate the retinal oxidative stress, glial and vascular changes that can be observed as the disease progresses. Wild type and rd1 mice received several doses of TRX. After treatment, animals were euthanized at postnatals days 11, 17, or 28. Glutathione (GSH) and other thiol compounds were determined by high performance liquid chromatography (HPLC). Glial fibrilary acidic protein (GFAP) and anti-ionized calcium binding adaptor molecule 1 (Iba1) were studied by immunohistochemistry. Vascular endothelial growth factor (VEGF) and hepatic growth factor (HGF) expression were determined by western blot. TRX administration significantly diminished cell death in rd1 mouse retinas and increased GSH retinal concentrations at postnatal day 11 (PN11). TRX was also able to reverse glial alterations at PN11 and PN17. No alterations were observed in retinal VEGF and HGF expression in rd1 mice. In conclusion, TRX treatment decreases photoreceptor death in the first stages of RP and this protective effect may be due in part to the GSH system activation and to a partially decrease in inflammation.

Nitrosative Stress in Retinal Pathologies: Review.

Nitric oxide (NO) is a gas molecule with diverse physiological and cellular functions. In the eye, NO is used to maintain normal visual function as it is involved in photoreceptor light transduction. In addition, NO acts as a rapid vascular endothelial relaxant, is involved in the control of retinal blood flow under basal conditions and mediates the vasodilator responses of different substances such as acetylcholine, bradykinin, histamine, substance P or insulin. However, the retina is rich in polyunsaturated lipid membranes and is sensitive to the action of reactive oxygen and nitrogen species. Products generated from NO (i.e., dinitrogen trioxide (N2O3) and peroxynitrite) have great oxidative damaging effects. Oxygen and nitrogen species can react with biomolecules (lipids, proteins and DNA), potentially leading to cell death, and this is particularly important in the retina. This review focuses on the role of NO in several ocular diseases, including diabetic retinopathy, retinitis pigmentosa, glaucoma or age-related macular degeneration (AMD).

Progesterone anti-inflammatory properties in hereditary retinal degeneration.

The interactions between steroid gonadal hormones and the retina (a part of the visual system and the central nervous system (CNS)) have received limited attention and beneficial effects of these hormones in retinal diseases is controversial. Retinitis pigmentosa (RP) is the most common cause of retinal hereditary blindness and to date no treatment is available. However, results regarding the effects of progesterone on the progression of RP are promising. With the idea of demonstrating if the progesterone retinal protection in RP is related to its possible anti-inflammatory properties, we have administered orally progesterone to rd10 mice, an animal model of RP. We observed that progesterone decreased photoreceptors cell death, reactive gliosis and the increase in microglial cells caused by RP. We also examined the expression of neuronal and inducible nitric oxide synthase (nNOS and iNOS), the enzyme responsible for NO production. The results demonstrated a decrease in nNOS expression only in control mice treated with progesterone. Inflammation has been related with an increase in lipid peroxidation. Noticeably progesterone administration was able to diminish retinal malondialdehyde (MDA, a lipid peroxidation product) concentrations in rd10 mice. Altogether, we can conclude that progesterone could be a good therapeutic option not only in RP but also for other retinal diseases that have been associated with inflammation and lipid peroxidation.

Oxidative stress and autophagy-related changes during retinal degeneration and development.

Retinitis pigmentosa (RP) is an inherited retinopathy that leads to photoreceptor loss. RP has been related to oxidative stress, autophagy, and inflammation. This study aimed to identify changes in the levels of oxidative stress and autophagy markers in the retina of control and rd10 mice during different phases of retinal development. Changes in the retinal oxidation system were investigated by measuring the levels of oxidized and reduced glutathione (GSH/GSSG), retinal avidin-positive cells, and 4-hydroxynonenal (4-HNE) staining intensity. Autophagy characterization was explored by measuring the levels of microtubule-associated protein 1 light chain 3 (LC3), beclin, autophagy-related proteins 5 and 7 (Atg5 and Atg7), and lysosomal associated membrane protein-2A (LAMP-2A). At P28 retinal GSH concentrations decreased in rd10 mice compared to the controls. No differences were found in retinal GSSG concentrations between the control and rd10 mice. There was an increase in retinal GSSG concentrations and a decrease in the GSH/GSSG ratio in the control and rd10 mice at P21 and P28 compared to P13. We observed an increase in avidin-positive cells in rd10 retinas. 4-HNE was increased in rd10 retinas at P13, and it also increased in control mice with age. We did not observe any differences in the retinal levels of LC3II/I ratio, Beclin, Atg5, or Atg7 in the rd10 mice compared to the controls. There was an increase in the LAMP-2A concentrations in the control and rd10 mice with development age (P28 concentrations vs. P13). Although only slight differences were found in the oxidative stress and autophagy markers between the control and rd10 mice, there were increases in the GSSG, 4-HNE, and LAMP-2A with age. This increase in the oxidative stress and chaperone-mediated autophagy has not been described before and occurred just after the mice opened their eyes, potentially indicating a retinal response to light exposure.

Lipoic Acid and Progesterone Alone or in Combination Ameliorate Retinal Degeneration in an Experimental Model of Hereditary Retinal Degeneration.

Retinitis pigmentosa (RP) is a group of inherited retinopathies characterized by photoreceptors death. Our group has shown the positive progesterone (P4) actions on cell death progression in an experimental model of RP. In an effort to enhance the beneficial effects of P4, the aim of this study was to combine P4 treatment with an antioxidant [lipoic acid (LA)] in the rd1 mice. rd1 and control mice were treated with 100 mg/kg body weight of P4, LA, or a combination of both on postnatal day 7 (PN7), 9, and 11, and were sacrificed at PN11. The administration of LA and/or P4 diminishes cell death in rd1 retinas. The effect obtained after the combined administration of LA and P4 is higher than the one obtained with LA or P4 alone. The three treatments decreased GFAP staining, however, in the far peripheral retina, and the two treatments that offered better results were LA and LA plus P4. LA or LA plus P4 increased retinal glutathione (GSH) concentration in the rd1 mice. Although LA and P4 are able to protect photoreceptors from death in rd1 mice retinas, a better effectiveness is achieved when administering LA and P4 at the same time.

Factors associated with self-medication in Spain: a cross-sectional study in different age groups.

OBJECTIVE: The identification of factors which may influence a patient's decision to self-medicate. METHODS: Descriptive, cross-sectional study of the adult population (at least 16 years old), using data from the 2009 European Health Interview Survey in Spain, which included 22 188 subjects. Logistic regression models enabled us to estimate the effect of each analysed variable on self-medication. KEY FINDINGS: In total, 14 863 (67%) individuals reported using medication (prescribed and non-prescribed) and 3274 (22.0%) of them self-medicated. Using logistic regression and stratifying by age, four different models have been constructed. Our results include different variables in each of the models to explain self-medication, but the one that appears on all four models is education level. Age is the other important factor which influences self-medication. Self-medication is strongly associated with factors related to socio-demographic, such as sex, educational level or age, as well as several health factors such as long-standing illness or physical activity. CONCLUSIONS: When our data are compared to those from previous Spanish surveys carried out in 2003 and 2006, we can conclude that self-medication is increasing in Spain.

A cross-sectional evaluation of the prevalence and detection of predictors of polypharmacy amongst adult in Spain.

OBJECTIVE: To investigate the association between polypharmacy and sociodemographic factors as well as health status, determinants of health and healthcare use, illness and use of prescribed medicines amongst adults in Spain. METHODS: Data from the 2009 European Health Interview Survey in Spain which included 22 188 subjects were used. Polypharmacy was defined as the use of five or more prescribed medicines. The association between polypharmacy and several variables was assessed by means of bivariate analysis and logistic regression analysis (adjusted by age and gender). KEY FINDINGS: Amongst study participants, 15.8% were on prescribed polypharmacy (19.3%, women; 10.3%, men (P < 0.001)). A number of sociodemographic factors (e.g. age, gender, educational level), health status factors (e.g. limitation in daily activities, self-perception of health, presence of chronic disease) and other health-related factors (e.g. smoking, alcohol drinking, physical activity) have been studied and have been found to play a role in polypharmacy. Logistic regression analysis provided three variables which together with age could be used to predict polypharmacy. CONCLUSION: In Spain, approximately 16% of people who take medicines are on polypharmacy and this is more frequent in women and amongst older adults. From our study, we can conclude that the variables which can predict a higher likelihood of polypharmacy are, together with age, prescribed antidepressants, and prescribed medicines for back/neck pain and joint pain. This may provide a tool for health professionals to readily assess polypharmacy appropriateness in polymedicated patients.

2-sulfonyliminodihydropyrimidines: a novel class of analgesic compounds.

A series of 2-sulfonyliminodihydropyrimidine derivatives have been synthesized and evaluated in vivo for their antinociceptive and anti-inflammatory activities. The results were compared with that of acetyl salicylic acid. Compounds 6Ab-d and 6Be displayed an interesting analgesic profile in the acetic acid-induced abdominal contractions test. Based on the results of the carrageenan-hind paw edema test, compound 6Af showed potential anti-inflammatory activity.

Differential effects of N-methyl-D-aspartate receptor blockade on nociceptive somatic and visceral reflexes.

N-methyl-D-aspartate (NMDA) receptors appear to play little part in nociceptive responses evoked by acute stimulation of normal somatic tissues, but rather are involved in hyperalgesic responses after peripheral injury and inflammation. Previous studies from this laboratory have shown important differences in the neural organization of somatic and visceral nociceptive pathways. Here, we have explored the role of NMDA receptors in processing acute visceral noxious input, compared with somatic noxious input. The left ureter was cannulated close to the bladder in adult female Wistar rats anaesthetized with pentobarbitone (50 mg/kg i.p). Graded distentions of the ureter (30 s, 25-80 mmHg) evoked increases in blood pressure. These responses were dose-dependently inhibited by the NMDA receptor ion channel blockers ketamine and memantine (ID50 = 2.4+/-1.6 and 14.5+/-1.3 mg/kg, i.v.), and by the Merz glycine site antagonist Mrz 2/ 576 (ID50 = 0.2+/-0.2 mg/kg). Graded pinch stimuli (30 s, 2-4 N) of one hind-paw evoked similar pressor responses which were not affected by ketamine (up to 10 mg/kg). Similarly, Mrz 2/576 did not affect responses to noxious pinch, whereas memantine (ID50 = 17+/-12 mg/kg) did inhibit responses to pinch stimuli. However, in the dose range used neither ketamine nor Mrz 2/576 inhibited a pressor response of non-nociceptive origin (produced by bilateral carotid occlusion) whereas memantine did. Thus the effects of memantine are likely due to a non-specific cardiovascular effect. These results show that NMDA receptor antagonists inhibit nociceptive reflexes evoked from the normal ureter, and suggest that NMDA receptors are involved in the processing of acute nociceptive inputs from viscera. We conclude that acute stimulation of normal visceral tissue provokes intense responses that recruit neural mechanisms mediated by NMDA receptors. However, in somatic pathways, these mechanisms are recruited only by an enhanced peripheral input such as that produced after injury or inflammation.