RESUMO
The persistence of chronic pain and continuing overdose deaths from pain-relieving opioids targeting µ opioid receptor (µOR) have fueled the need for reliable long-term analgesics which use different targets and mechanisms. The δ opioid receptor (δOR) is a potential alternative target for non-addictive analgesics to alleviate chronic pain, made more attractive by its lack of respiratory depression associated with µOR agonists. However, early δOR full agonists were found to induce seizures, precluding clinical use. Partial δOR agonists may offer more controlled activation of the receptor compared to full agonists, but the development of such ligands has been hindered by uncertainty over the molecular mechanism mediating partial agonism. Using a structure-based approach, we explored the engagement of the sodium binding pocket in δOR and developed a bitopic ligand, C6-Quino, predicted to be a selective δOR partial agonist. Functional studies of C6-Quino revealed that it displayed δOR partial agonist activity at both G-protein and arrestin pathways. Its interaction with the sodium pocket was confirmed and analyzed using a single particle cryo-EM. Additionally, C6-Quino demonstrated favorable chemical and physiological properties like oral activity, and analgesic activity in multiple chronic pain models. Notably, µOR-related hyperlocomotion and respiratory depression, and δOR-related convulsions, were not observed at analgesic doses of C6-Quino. This fundamentally new approach to designing δOR ligands provides a blueprint for the development of partial agonists as safe analgesics and acts as a generic method to optimize signaling profiles of other Class A GPCRs.
Assuntos
Doenças Autoimunes , Doença de Meniere , Humanos , Doença de Meniere/diagnóstico , Doença de Meniere/imunologia , Masculino , Diagnóstico Diferencial , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/imunologia , Feminino , Pessoa de Meia-Idade , Adulto , Orelha Interna/imunologia , Audiometria de Tons Puros , Idoso , Doenças do Labirinto/imunologia , Doenças do Labirinto/diagnóstico , Teste do Impulso da CabeçaRESUMO
Aging is accompanied by an increased prevalence of degenerative conditions, including those affecting ocular health, which significantly impact quality of life and increase the burden on healthcare systems. Among these, retinal aging is of particular concern due to its direct link to vision impairment, a leading cause of disability in the elderly. Vision loss in the aging population is associated with heightened risks of cognitive decline, social isolation, and morbidity. This study addresses the critical gap in our understanding of modifiable lifestyle factors, such as physical exercise, that may mitigate retinal aging and its related pathologies. We investigated the effects of different exercise regimens-voluntary (recreational-type) and forced (high-intensity)-on the retinal health of aging Wistar rats (18-month-old), serving as a model for studying the translational potential of exercise interventions in humans. Male Wistar rats were divided into four groups: a young control (3-month-old) for baseline comparison, an aged sedentary control, an aged group engaging in voluntary exercise via a running wheel in their cage, and an aged group subjected to forced exercise on a treadmill for six sessions of 20 min each per week. After a 6-month experimental period, we assessed retinal function via electroretinography (ERG), measured retinal thickness histologically, and analyzed protein expression changes relevant to oxidative stress, inflammation, and anti-aging mechanisms. Our findings reveal that voluntary exercise positively impacts retinal function and morphology, reducing oxidative stress and inflammation markers while enhancing anti-aging protein expression. In contrast, forced exercise showed diminished benefits. These insights underscore the importance of exercise intensity and preference in preserving retinal health during aging. The study highlights the potential of recreational physical activity as a non-invasive strategy to counteract retinal aging, advocating for further research into exercise regimens as preventative therapies for age-related ocular degenerations.
Assuntos
Envelhecimento , Eletrorretinografia , Condicionamento Físico Animal , Ratos Wistar , Retina , Animais , Condicionamento Físico Animal/fisiologia , Condicionamento Físico Animal/métodos , Masculino , Envelhecimento/fisiologia , Ratos , Estresse Oxidativo/fisiologiaRESUMO
Retinal vascular diseases and consequential metabolic disturbances in the eye are major concerns for healthcare systems all around the world. BGP-15, a drug candidate small-molecule [O-(3-piperidino-2-hydroxy-1-propyl) nicotinic amidoxime dihydrochloride], has been formerly demonstrated by our workgroup to be retinoprotective both in the short and long term. Based on these results, the present study was performed to investigate the efficacy of BGP in an eyedrop formulation containing sulfobutylether-ß-cyclodextrin (SBECD), which is a solubility enhancer as well. Electroretinographical evaluations were carried out and BGP was demonstrated to improve both scotopic and photopic retinal a- and b-waves, shorten their implicit times and restore oscillatory potentials after ischemia-reperfusion. It was also observed to counteract retinal thinning after ischemia-reperfusion in the eyes of Sprague Dawley rats. This small-molecule drug candidate is able to compensate for experimental global eye ischemia-reperfusion injury elicited by ligation of blood vessels in rats. We successfully demonstrated that BGP is able to exert its protective effects on the retina even if administered in the form of eyedrops.
RESUMO
Numerous studies have indicated a link between vaccines and the exacerbation of autoimmune diseases including rheumatoid arthritis (RA). However, there is no consensus in clinical practice regarding the optimal timing of immunization. Therefore, this study aimed to investigate the impact of the 3Fluart influenza vaccine on the complete Freund's adjuvant (CFA)-induced chronic arthritis rat model and to identify new biomarkers with clinical utility. CFA was injected into the plantar surface of one hind paw and the root of the tail on day 0, and the tail root injection was repeated on day 1. Flu vaccination was performed on day 1 or 7. Paw volume was measured by plethysmometry, mechanonociceptive threshold by dynamic plantar aesthesiometry, neutrophil myeloperoxidase (MPO) activity, and vascular leakage using in vivo optical imaging throughout the 21-day experiment. Inflammatory markers were determined by Western blot and histopathology. CFA-induced swelling, an increase in MPO activity, plasma extravasation in the tibiotarsal joint. Mechanical hyperalgesia of the hind paw was observed 3 days after the injection, which gradually decreased. Co-administration of the flu vaccine on day 7 but not on day 1 resulted in significantly increased heme oxygenase 1 (HO-1) expression. The influenza vaccination appears to have a limited impact on the progression and severity of the inflammatory response and associated pain. Nevertheless, delayed vaccination could alter the disease activity, as indicated by the findings from assessments of edema and inflammatory biomarkers. HO-1 may serve as a potential marker for the severity of inflammation, particularly in the case of delayed vaccination. However, further investigation is needed to fully understand the regulation and role of HO-1, a task that falls outside the scope of the current study.
Assuntos
Artrite Experimental , Influenza Humana , Ratos , Animais , Humanos , Artrite Experimental/metabolismo , Adjuvante de Freund/efeitos adversos , Hiperalgesia/metabolismo , Inflamação , Vacinação , Progressão da DoençaRESUMO
Steroid-based histamine H3 receptor antagonists (d-homoazasteroids) were designed by combining distinct structural elements of HTS hit molecules. They were characterized, and several of them displayed remarkably high affinity for H3 receptors with antagonist/inverse agonist features. Especially, the 17a-aza-d-homolactam chemotype demonstrated excellent H3R activity together with significant in vivo H3 antagonism. Optimization of the chemotype was initiated with special emphasis on the elimination of the hERG and muscarinic affinity. Additionally, ligand-based SAR considerations and molecular docking studies were performed to predict binding modes of the molecules. The most promising compounds (XXI, XXVIII, and XX) showed practically no muscarinic and hERG affinity. They showed antagonist/inverse agonist property in the in vitro functional tests that was apparent in the rat in vivo dipsogenia test. They were considerably stable in human and rat liver microsomes and provided significant in vivo potency in the place recognition and novel object recognition cognitive paradigms.
Assuntos
Antagonistas dos Receptores Histamínicos H3 , Receptores Histamínicos H3 , Ratos , Humanos , Animais , Histamina , Agonismo Inverso de Drogas , Receptores Histamínicos H3/metabolismo , Simulação de Acoplamento Molecular , Agonistas dos Receptores Histamínicos/farmacologia , Agonistas dos Receptores Histamínicos/metabolismo , Esteroides , Microssomos Hepáticos/metabolismo , Antagonistas dos Receptores Histamínicos H3/farmacologia , Antagonistas dos Receptores HistamínicosRESUMO
Abstract The aim of the present research was to reveal what kind of values, self-conceptualisation and beliefs of personhood characterize two generations of Hungarians, almost three decades after the socio-political changes from socialism to capitalist market economy. Participants were high school students (N = 239) and adults (N = 122). Value-orientation was measured using the Portrait Value Questionnaire (PVQ, Schwartz et al., 2001), beliefs of personhood were measured by the Lay Contextualism Scale (Owe et al., 2013). Self-construals were measured in case of the high school students by using 23 items from Gudykunst et al. (1996) self-construal scale and in case of the adults a modified version of it (Owe et al., 2013). Results indicate that in the post-socialist Hungary, individualistic values and independent self-concept strongly characterize both the high school students and the adults, but the younger generation displays higher tendency towards individualism.
Resumen El objetivo del presente trabajo fue encontrar qué tipo de valores, auto-conceptuación y creencias de la persona caracterizan dos generaciones de húngaros, casi tres décadas después de los cambios sociopolíticos del socialismo al mercado económico capitalista. Los participantes fueron estudiantes universitarios (N=239) y adultos (N=122). La orientación hacia los valores fue evaluada utilizando el Cuestionario de Valores (PVQ, Portrait Value Questionnaire; Schwartz et al., 2001), las creencias sobre la persona fueron evaluados a través de la Escala de Contextualismo (Owe et al., 2013), las auto-definiciones fueron evaluadas utilizando los 23 reactivos de la escala de autodefinición de Gudykunst et al. (1996) para el caso de los estudiantes, y para los adultos se utilizó la versión modificada del instrumento de autodefinición (Owe et al., 2013). Los resultados indican que, en la Hungría post-socialista, los valores individualistas y un autoconcepto independiente caracterizan fuertemente a ambos grupos, aunque la generación más joven muestra mayor tendencia hacia el individualismo.