RESUMEN
Autophagosome formation initiated on the endoplasmic reticulum (ER)-associated omegasome requires LC3. Translational regulation of LC3 biosynthesis is unexplored. Here we demonstrate that LC3 mRNA is recruited to omegasomes by directly binding to the ER transmembrane Sigma-1 receptor (S1R). Cell-based and in vitro reconstitution experiments show that S1R interacts with the 3' UTR of LC3 mRNA and ribosomes to promote LC3 translation. Strikingly, the 3' UTR of LC3 is also required for LC3 protein lipidation, thereby linking the mRNA-3' UTR to LC3 function. An autophagy-defective S1R mutant responsible for amyotrophic lateral sclerosis cannot bind LC3 mRNA or induce LC3 translation. We propose a model wherein S1R de-represses LC3 mRNA via its 3' UTR at the ER, enabling LC3 biosynthesis and lipidation. Because several other LC3-related proteins use the same mechanism, our data reveal a conserved pathway for localized translation essential for autophagosome biogenesis with insights illuminating the molecular basis of a neurodegenerative disease.
Asunto(s)
Regiones no Traducidas 3' , Autofagia , Retículo Endoplásmico , Proteínas Asociadas a Microtúbulos , Biosíntesis de Proteínas , ARN Mensajero , Receptores sigma , Receptor Sigma-1 , Receptores sigma/metabolismo , Receptores sigma/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Retículo Endoplásmico/metabolismo , Humanos , ARN Mensajero/metabolismo , ARN Mensajero/genética , Regiones no Traducidas 3'/genética , Ribosomas/metabolismo , Animales , Autofagosomas/metabolismo , Células HeLaRESUMEN
Distal hereditary motor neuropathy (dHMN) is a progressive neurological disease characterized by distal limb muscle weakness and amyotrophy. Sigma 1 receptor (σ1R), a gene product of SIGMAR1, mutations have been reported to induce dHMN, but its mechanism remains unknown. This study aims to explore the effect of C238T and 31_50del mutations in σ1R on neuronal SH-SY5Y cell functions. The SH-SY5Y cells that overexpressed σ1R, C238T mutant σ1R (σ1RC238T) or 31_50del mutant σ1R (σ1R31_50del) were constructed by pEGFPN1 vectors. We used Western blot (WB) and immunofluorescence (IF) staining to detect the expression of σ1R and green fluorescent proteins (GFP). Then, we evaluated the impact of σ1R mutation on apoptosis, autophagy, endoplasmic reticulum stress, and the involvement of the unfolded protein response (UPR) pathway in SH-SY5Y cells. We found that σ1RC238T and σ1R31_50del downregulated σ1R and promoted the apoptosis of SH-SY5Y cells. σ1RC238T and σ1R31_50del increased p-PERK, p-eIF2α, p-JNK, BIP, ATF4, CHOP, ATF6, XBP1, Caspase3, Caspase12 expressions and Ca2+ concentration, whereas decreased ATP content in SH-SY5Y cells. Besides, the expressions of LC3B, Lamp1, ATG7, Beclin-1 and phosphorylation of AMPK and ULK1 were increased, while the p62 level decreased after C238T or 31_50del mutation of σ1R. Additionally, AMPK knockdown abolished the apoptosis mediated by σ1RC238T or σ1R31_50del in SH-SY5Y cells. Our results indicated that C238T or 31_50del mutation in σ1R promoted motor neuron apoptosis through the AMPK/ULK1 pathway in dHMN. This study shed light on a better understanding of the neurons pathological mechanisms mediated by σ1R C238T and σ1R 31-50del in dHMN.
Asunto(s)
Apoptosis , Homólogo de la Proteína 1 Relacionada con la Autofagia , Autofagia , Estrés del Retículo Endoplásmico , Receptores sigma , Receptor Sigma-1 , Humanos , Receptores sigma/metabolismo , Receptores sigma/genética , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Línea Celular Tumoral , Transducción de Señal , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Respuesta de Proteína Desplegada , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , MutaciónRESUMEN
The mechanisms for neuropathic pain amelioration by sigma-1 receptor inhibition are not fully understood. We studied genome-wide transcriptomic changes (RNAseq) in the dorsal root ganglia (DRG) from wild-type and sigma-1 receptor knockout mice prior to and following Spared Nerve Injury (SNI). In wildtype mice, most of the transcriptomic changes following SNI are related to the immune function or neurotransmission. Immune function transcripts contain cytokines and markers for immune cells, including macrophages/monocytes and CD4 + T cells. Many of these immune transcripts were attenuated by sigma-1 knockout in response to SNI. Consistent with this we found, using flow cytometry, that sigma-1 knockout mice showed a reduction in macrophage/monocyte recruitment as well as an absence of CD4 + T cell recruitment in the DRG after nerve injury. Sigma-1 knockout mice showed a reduction of neuropathic (mechanical and cold) allodynia and spontaneous pain-like responses (licking of the injured paw) which accompany the decreased peripheral neuroinflammatory response after nerve injury. Treatment with maraviroc (a CCR5 antagonist which preferentially inhibits CD4 + T cells in the periphery) of neuropathic wild-type mice only partially replicated the sigma-1 knockout phenotype, as it did not alter cold allodynia but attenuated spontaneous pain-like responses and mechanical hypersensitivity. Therefore, modulation of peripheral CD4 + T cell activity might contribute to the amelioration of spontaneous pain and neuropathic tactile allodynia seen in the sigma-1 receptor knockout mice, but not to the effect on cold allodynia. We conclude that sigma-1 receptor inhibition decreases DRG neuroinflammation which might partially explain its anti-neuropathic effect.
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Ratones Endogámicos C57BL , Ratones Noqueados , Neuralgia , Receptores sigma , Receptor Sigma-1 , Transcriptoma , Animales , Receptores sigma/genética , Receptores sigma/metabolismo , Receptores sigma/antagonistas & inhibidores , Neuralgia/metabolismo , Ratones , Femenino , Enfermedades Neuroinflamatorias/metabolismo , Ganglios Espinales/metabolismo , Traumatismos de los Nervios Periféricos/metabolismoRESUMEN
Neuroactive steroids (NASs) directly affect neuronal excitability. Despite their role in the nervous system is intimately linked to pain control, knowledge is currently limited. This study investigates the peripheral involvement of NASs in chronic ischemic pain by targeting the cytochrome P450 side-chain cleavage enzyme (P450scc). Using a rat model of hind limb thrombus-induced ischemic pain (TIIP), we observed an increase in P450scc expression in the ischemic hind paw skin. Inhibiting P450scc with intraplantar aminoglutethimide (AMG) administration from post-operative day 0 to 3 significantly reduced the development of mechanical allodynia. However, AMG administration from post-operative day 3 to 6 did not affect established mechanical allodynia. In addition, we explored the role of the peripheral sigma-1 receptor (Sig-1R) by co-administering PRE-084 (PRE), a Sig-1R agonist, with AMG. PRE reversed the analgesic effects of AMG during the induction phase. These findings indicate that inhibiting steroidogenesis with AMG alleviates peripheral ischemic pain during the induction phase via Sig-1Rs.
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Modelos Animales de Enfermedad , Hiperalgesia , Isquemia , Ratas Sprague-Dawley , Receptores sigma , Animales , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/patología , Hiperalgesia/complicaciones , Masculino , Isquemia/complicaciones , Isquemia/patología , Receptores sigma/antagonistas & inhibidores , Receptores sigma/metabolismo , Receptor Sigma-1 , Dolor/tratamiento farmacológico , Dolor/complicaciones , Dolor/etiología , Dolor/patología , Miembro Posterior/efectos de los fármacos , Ratas , Sistema Enzimático del Citocromo P-450/metabolismoRESUMEN
Oxalate-induced damage to renal tubular epithelial cells (RTECs) is an essential factor in the incident kidney stone, but the specific mechanism is unclear. Recent research has pinpointed interacting areas within the endoplasmic reticulum and mitochondria, called mitochondria-associated membranes (MAMs). These studies have linked endoplasmic reticulum stress (ERS) and oxidative imbalance to kidney disease development. The sigma-1 receptor (S1R), a specific protein found in MAMs, is involved in various physiological processes, but its role in oxalate-induced kidney stone formation remains unclear. In this study, we established cellular and rat models of oxalate-induced kidney stone formation to elucidate the S1R's effects against ERS and apoptosis and its mechanism in oxalate-induced RTEC injury. We found that oxalate downregulated S1R expression in RTECs and escalated oxidative stress and ERS, culminating in increased apoptosis. The S1R agonist dimemorfan up-regulated S1R expression and mitigated ERS and oxidative stress, thereby reducing apoptosis. This protective effect was mediated through S1R inhibition of the CHOP pathway. Animal experiments demonstrated that S1R's activation attenuated oxalate-induced kidney injury and alleviated kidney stone formation. This is the first study to establish the connection between S1R and kidney stones, suggesting S1R's protective role in inhibiting ERS-mediated apoptosis to ameliorate kidney stone formation.
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Apoptosis , Estrés del Retículo Endoplásmico , Retículo Endoplásmico , Células Epiteliales , Túbulos Renales , Mitocondrias , Nefrolitiasis , Receptores sigma , Receptor Sigma-1 , Receptores sigma/metabolismo , Animales , Estrés del Retículo Endoplásmico/efectos de los fármacos , Apoptosis/efectos de los fármacos , Ratas , Células Epiteliales/metabolismo , Células Epiteliales/efectos de los fármacos , Túbulos Renales/metabolismo , Túbulos Renales/patología , Nefrolitiasis/metabolismo , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Retículo Endoplásmico/efectos de los fármacos , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas Sprague-DawleyRESUMEN
Epilepsy is a neurological disorder characterized by recurrent spontaneous seizures alongside other neurological comorbidities. Cognitive impairment is the most frequent comorbidity secondary to progressive neurologic changes in epilepsy. Sigma 1 receptors (σ1 receptors) are involved in the neuroprotection and pathophysiology of both conditions and targeting these receptors may have the potential to modulate both seizures and comorbidities. The current research demonstrated the effect of clemastine (10 mg/kg, P.O.), a non-selective σ1 receptor agonist, on pentylenetetrazol (PTZ) (35 mg/kg, i.p., every 48 h for 14 doses)-kindling rats by acting on σ1 receptors through its anti-inflammatory/antioxidant capacity. Clemastine and phenytoin (30 mg/kg, P.O.) or their combination were given once daily. Clemastine treatment showed a significant effect on neurochemical, behavioural, and histopathological analyses through modulation of σ1 receptors. It protected the kindling animals from seizures and attenuated their cognitive impairment in the Morris water maze test by reversing the PTZ hippocampal neuroinflammation/oxidative stress state through a significant increase in inositol-requiring enzyme 1 (IRE1), x-box binding protein 1 (XBP1), along with a reduction of total reactive oxygen species (TROS) and amyloid beta protein (Aß). The involvement of σ1 receptors in the protective effects of clemastine was confirmed by their abrogation when utilizing NE-100, a selective σ1 receptor antagonist. In light of our findings, modulating σ1 receptors emerges as a compelling therapeutic strategy for epilepsy and its associated cognitive impairments. The significant neuroprotective effects observed with clemastine underscore the potential of σ1 receptor-targeted treatments to address both the primary symptoms and comorbidities of neurological disorders.
Asunto(s)
Disfunción Cognitiva , Excitación Neurológica , Fármacos Neuroprotectores , Pentilenotetrazol , Receptores sigma , Convulsiones , Receptor Sigma-1 , Animales , Receptores sigma/metabolismo , Receptores sigma/agonistas , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Convulsiones/tratamiento farmacológico , Convulsiones/metabolismo , Masculino , Ratas , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/prevención & control , Excitación Neurológica/efectos de los fármacos , Reposicionamiento de Medicamentos , Ratas Wistar , Estrés Oxidativo/efectos de los fármacos , Modelos Animales de Enfermedad , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Anticonvulsivantes/farmacología , Anticonvulsivantes/uso terapéuticoRESUMEN
The sigma-1 receptor (σ1R) is a non-opioid membrane receptor, which responds to a diverse array of synthetic ligands to exert various pharmacological effects. Meanwhile, candidates for endogenous ligands of σ1R have also been identified. However, how endogenous ligands bind to σ1R remains unknown. Here, we present crystal structures of σ1R from Xenopus laevis (xlσ1R) bound to two endogenous neurosteroid ligands, progesterone (a putative antagonist) and dehydroepiandrosterone sulfate (DHEAS) (a putative agonist), at 2.15-3.09 Å resolutions. Both neurosteroids bind to a similar location in xlσ1R mainly through hydrophobic interactions, but surprisingly, with opposite binding orientations. DHEAS also forms hydrogen bonds with xlσ1R, whereas progesterone interacts indirectly with the receptor through water molecules near the binding site. Binding analyses are consistent with the xlσ1R-neurosteroid complex structures. Furthermore, molecular dynamics simulations and structural data reveal a potential water entry pathway. Our results provide insight into binding of two endogenous neurosteroid ligands to σ1R.
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Sulfato de Deshidroepiandrosterona , Simulación de Dinámica Molecular , Progesterona , Receptores sigma , Receptor Sigma-1 , Xenopus laevis , Receptores sigma/metabolismo , Receptores sigma/química , Animales , Ligandos , Sitios de Unión , Progesterona/metabolismo , Progesterona/química , Sulfato de Deshidroepiandrosterona/metabolismo , Sulfato de Deshidroepiandrosterona/química , Unión Proteica , Cristalografía por Rayos X , Neuroesteroides/metabolismo , Neuroesteroides/química , Enlace de Hidrógeno , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
Herein, we report the synthesis of new 4-amino-2-(piperidin-3-yl)isoindoline-1,3-diones and their biological evaluation in a series of in vitro experiments. The synthetic production of these materials was initiated upon the condensation of appropriate nitrophthalic acid derivatives with various 3-aminopiperidines; subsequent reduction provided the final products in moderate to good yields. Readily available chiral pool reagents facilitated entry into optically enriched samples, while the piperidine scaffold furnished a variety of amide and alkylated entries. In total, 16 candidates were produced, and their ensuing treatment in LPS-challenged RAW cells effected slight reductions in secreted TNF-α but provided more robust and dose-dependent declines in nitrite and IL-6 levels relative to basal amounts, all concurrent with maintenance of cellular viability across the concentration ranges screened. The secondary amine cohort including rac-6, (R)-7, and (S)-8 rendered the most pronounced dose-dependent reductions in nitrite and IL-6. When dosed at 30 µM, (R)-7 demonstrated the most compelling effects, with decreases of 32 % and 40 % for nitrite and IL-6, respectively. Notable reductions in the inflammatory markers were also observed for 19 which effected declines in TNF-α (14 %), nitrite (19 %), and IL-6 (11 %) when treated at 30 µM. Additionally, four representative compounds were further evaluated against numerous CNS receptors, channels, and transporters, with 6, 9, and 19 demonstrating varying degrees of nanomolar-to-low-micromolar binding to the σ-1 and σ-2 receptors and also to serotonin receptors 5HT2A, 5HT2B and 5HT3. In this regard, 6 displayed perhaps the most noteworthy affinities, with binding at σ-2 (Ki = 2.2uM), 5HT2B (Ki = 561 nM) and 5HT3 (Ki = 536 nM). Furthermore, no pronounced or dose-dependent Cereblon/DDB1 binding was observed for the screened representative compounds 6, 9, 18 and 19.
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Inflamación , Lipopolisacáridos , Receptores de Serotonina , Receptores sigma , Animales , Lipopolisacáridos/farmacología , Lipopolisacáridos/antagonistas & inhibidores , Ratones , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Receptores de Serotonina/metabolismo , Receptores sigma/metabolismo , Células RAW 264.7 , Piperidinas/química , Piperidinas/farmacología , Piperidinas/síntesis química , Relación Dosis-Respuesta a Droga , Estructura Molecular , Relación Estructura-Actividad , Interleucina-6/metabolismo , Supervivencia Celular/efectos de los fármacos , Biomarcadores/metabolismoRESUMEN
Ochratoxin A (OTA), a secondary fungal metabolite known for its nephrotoxic effects, is prevalent in various feeds and food items. Our recent study suggests that OTA-induced nephrotoxicity is linked to the Sigma-1 receptor (Sig-1R)-mediated mitochondrial pathway apoptosis in human proximal tubule epithelial-originated kidney-2 (HK-2) cells. However, the contribution of Sig-1R to OTA-induced nephrotoxicity involving other forms of regulated cell death, such as ferroptosis, remains unexplored. In this investigation, cell viability, malondialdehyde (MDA) levels, glutathione (GSH) levels, and protein expressions in HK-2 cells treated with OTA and/or Ferrostatin-1/blarcamesine hydrochloride/BD1063 dihydrochloride were assessed. The results indicate that a 24 h-treatment with 1 µM OTA significantly induces ferroptosis by inhibiting Sig-1R, subsequently promoting nuclear receptor coactivator 4 (NCOA4), long-chain fatty acid-CoA ligase 4 (ACSL4), arachidonate 5-lipoxygenase (ALOX5), autophagy protein 5 (ATG5), and ATG7, inhibiting ferritin heavy chain (FTH1), solute carrier family 7 member 11 (SLC7A11/xCT), glutathione peroxidase 4 (GPX4), peroxiredoxin 6 (PRDX6), and ferroptosis suppressor protein 1 (FSP1), reducing GSH levels, and increasing MDA levels (P < 0.05). In conclusion, OTA induces ferroptosis by inhibiting Sig-1R, subsequently promoting ferritinophagy, inhibiting GPX4/FSP1 antioxidant systems, reducing GSH levels, and ultimately increasing lipid peroxidation levels in vitro.
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Ferroptosis , Ocratoxinas , Receptores sigma , Receptor Sigma-1 , Ocratoxinas/toxicidad , Ferroptosis/efectos de los fármacos , Receptores sigma/metabolismo , Humanos , Línea Celular , Túbulos Renales Proximales/efectos de los fármacos , Túbulos Renales Proximales/metabolismo , Supervivencia Celular/efectos de los fármacos , Glutatión/metabolismoRESUMEN
AIM: Methamphetamine (METH) chronic exposure is an important risk factor for hypertension development. However, the mechanisms behind METH-induced hypertension remain unclear. Therefore, we aimed to reveal the potential mechanisms underlying METH-induced hypertension. METHODS AND RESULTS: We structured the mouse hypertension model by METH, and observed that METH-treated mice have presented vascular remodeling (large-and small-size arteries) with collagen deposit around the vessel and increasing blood pressure (BP) and Sigma1 receptor (Sigmar1) in vascular tissue. We hypothesized that Sigmar1 is crucial in METH-induced hypertension and vascular remodeling. Sigmar1 knockout (KO) mice and antagonist (BD1047) pretreated mice exposed to METH for six-week showed higher BP and more collagen deposited around vessels than wild-type (WT) mice exposed to METH for six-week, in contrast, mice pretreated with Sigmar1 agonist (PRE-084) had unchanged BP and perivascular collagen despite the six-week METH exposure. Furthermore, we found that METH exposure induced vascular smooth muscle cells (VSMCs) and mesenchymal stem cells to differentiate into the myofibroblast-like cell and secrete collagen into surrounding vessels. Mechanically, Sigmar1 can suppress the COL1A1 expression by blocking the classical fibrotic TGF-ß/Smad2/3 signaling pathway in METH-exposed VSMCs and mesenchymal stem cells. CONCLUSION: Our results suggest that Sigmar1 is involved in METH-induced hypertension and vascular fibrosis by blocking the activation of the TGF-ß/Smad2/3 signaling pathway. Accordingly, Sigmar1 may be a novel therapeutic target for METH-induced hypertension and vascular fibrosis.
Asunto(s)
Hipertensión , Metanfetamina , Músculo Liso Vascular , Receptores sigma , Receptor Sigma-1 , Animales , Masculino , Ratones , Presión Sanguínea/efectos de los fármacos , Colágeno/metabolismo , Modelos Animales de Enfermedad , Hipertensión/inducido químicamente , Hipertensión/metabolismo , Hipertensión/patología , Hipertensión/genética , Células Madre Mesenquimatosas/metabolismo , Metanfetamina/efectos adversos , Metanfetamina/toxicidad , Ratones Endogámicos C57BL , Ratones Noqueados , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Músculo Liso Vascular/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Miocitos del Músculo Liso/efectos de los fármacos , Receptores sigma/metabolismo , Receptores sigma/genética , Transducción de Señal/efectos de los fármacos , Remodelación Vascular/efectos de los fármacosRESUMEN
Sigma-1 receptor (S1R) is involved in a large array of biological functions due to its ability to interact with various proteins and ion channels. Crystal structures of human S1R revealed the trimeric organization for which each protomer comprises the ligand binding pocket. This study applied a multistep computational procedure to develop a pharmacophore model obtained from molecular dynamics simulations of available cocrystal structures of well-known S1R ligands. Apart from the well-established positive ionizable and hydrophobic features, the obtained model included an additional specific hydrophobic feature and different excluded volumes, thus increasing the selectivity of the model as well as a more detailed determination of the distance between two essential features. The obtained pharmacophore model passed the validation test by receiver operating characteristic (ROC) curve analysis of active and inactive S1R ligands. Finally, the pharmacophoric performance was experimentally investigated through the synthesis and binding assay of new 4-phenylpiperazine-based compounds. The most active new ligand 2-(3-methyl-1-piperidyl)-1-(4-phenylpiperazin-1-yl)ethanone (3) showed an S1R affinity close to the reference compound haloperidol (Ki values of 4.8 and 2.6 nM, respectively). The proposed pharmacophore model can represent a useful tool to design and discover new potent S1R ligands.
Asunto(s)
Simulación de Dinámica Molecular , Receptores sigma , Receptor Sigma-1 , Receptores sigma/metabolismo , Receptores sigma/química , Ligandos , Humanos , Piperazinas/química , Piperazinas/metabolismo , Unión Proteica , Sitios de Unión , Conformación ProteicaRESUMEN
Methamphetamine (Meth) is a potent psychostimulant with well-established hepatotoxicity. Gut microbiota-derived short-chain fatty acids (SCFAs) have been reported to yield beneficial effects on the liver. In this study, we aim to further reveal the mechanisms of Meth-induced hepatic injuries and investigate the potential protective effects of SCFAs. Herein, mice were intraperitoneally injected with 15â¯mg/kg Meth to induce hepatic injuries. The composition of fecal microbiota and SCFAs was profiled using 16â¯S rRNA sequencing and Gas Chromatography/Mass Spectrometry (GC/MS) analysis, respectively. Subsequently, SCFAs supplementation was performed to evaluate the protective effects against hepatic injuries. Additionally, Sigma-1 receptor knockout (S1R-/-) mice and fluvoxamine (Flu), an agonist of S1R, were introduced to investigate the mechanisms underlying the protective effects of SCFAs. Our results showed that Meth activated S1R and induced hepatic autophagy, inflammation, and oxidative stress by stimulating the MAPK/ERK pathway. Meanwhile, Meth disrupted SCFAs product-related microbiota, leading to a reduction in fecal SCFAs (especially Acetic acid and Propanoic acid). Accompanied by the optimization of gut microbiota, SCFAs supplementation normalized S1R expression and ameliorated Meth-induced hepatic injuries by repressing the MAPK/ERK pathway. Effectively, S1R knockout repressed Meth-induced activation of the MAPK/ERK pathway and further ameliorated hepatic injuries. Finally, the overexpression of S1R stimulated the MAPK/ERK pathway and yielded comparable adverse phenotypes to Meth administration. These findings suggest that Meth-induced hepatic injuries relied on the activation of S1R, which could be alleviated by SCFAs supplementation. Our study confirms the crucial role of S1R in Meth-induced hepatic injuries for the first time and provides a potential preemptive therapy.
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Enfermedad Hepática Inducida por Sustancias y Drogas , Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Metanfetamina , Ratones Noqueados , Receptores sigma , Receptor Sigma-1 , Metanfetamina/toxicidad , Animales , Receptores sigma/metabolismo , Ácidos Grasos Volátiles/metabolismo , Ratones , Microbioma Gastrointestinal/efectos de los fármacos , Masculino , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Heces/química , Heces/microbiologíaRESUMEN
Major depressive disorder (MDD) is a global health burden characterized by persistent low mood, deprivation of pleasure, recurrent thoughts of death, and physical and cognitive deficits. The current understanding of the pathophysiology of MDD is lacking, resulting in few rapid and effective antidepressant therapies. Recent studies have pointed to the sigma-1 (σ-1) receptor as a potential rapid antidepressant target; σ-1 agonists have shown promise in a variety of preclinical depression models. Hypidone hydrochloride (YL-0919), an independently developed antidepressant by our institute with faster onset of action and low rate of side effects, has recently emerged as a highly selective σ-1 receptor agonist; however, its underlying astrocyte-specific mechanism is unknown. In this study, we investigated the effect of YL-0919 treatment on gene expression in the prefrontal cortex of depressive-like mice by single-cell RNA sequencing. Furthermore, we knocked down σ-1 receptors on astrocytes in the medial prefrontal cortex of mice to explore the effects of YL-0919 on depressive-like behavior and neuroinflammation in mice. Our results demonstrated that astrocyte-specific knockdown of σ-1 receptor resulted in depressive-like behavior in mice, which was reversed by YL-0919 administration. In addition, astrocytic σ-1 receptor deficiency led to activation of the NF-κB inflammatory pathway, and crosstalk between reactive astrocytes and activated microglia amplified neuroinflammation, exacerbating stress-induced neuronal apoptosis. Furthermore, the depressive-like behavior induced by astrocyte-specific knockdown of the σ-1 receptor was improved by a selective NF-κB inhibitor, JSH-23, in mice. Our study not only reaffirms the σ-1 receptor as a key target of the faster antidepressant effect of YL-0919, but also contributes to the development of astrocytic σ-1 receptor-based novel drugs.
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Antidepresivos , Astrocitos , Trastorno Depresivo Mayor , Ratones Endogámicos C57BL , FN-kappa B , Corteza Prefrontal , Receptores sigma , Receptor Sigma-1 , Receptores sigma/metabolismo , Receptores sigma/agonistas , Animales , Astrocitos/metabolismo , Astrocitos/efectos de los fármacos , Ratones , Corteza Prefrontal/metabolismo , Corteza Prefrontal/efectos de los fármacos , Antidepresivos/farmacología , FN-kappa B/metabolismo , Masculino , Trastorno Depresivo Mayor/metabolismo , Trastorno Depresivo Mayor/tratamiento farmacológico , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Modelos Animales de Enfermedad , Depresión/metabolismo , Depresión/tratamiento farmacológicoRESUMEN
Previous studies have shown that ligands that bind to sigma-2 receptor/TMEM97 (s2R/TMEM97), a transmembrane protein, have anxiolytic/antidepressant-like properties and relieve neuropathic pain-like effects in rodents. Despite medical interest in s2R/TMEM97, little affective and pain behavioral characterization has been done using transgenic mice, which limits the development of s2R/TMEM97 as a viable therapeutic target. Using wild-type (WT) and global Tmem97 knock-out (KO) mice, we sought to identify the contribution of Tmem97 in modulating affective and pain-like behaviors using a battery of affective and pain assays, including open field, light/dark preference, elevated plus maze, forced swim test, tail suspension test, and the mechanical sensitivity tests. Our results demonstrate that female Tmem97 KO mice show less anxiety-like and depressive-like behaviors in light/dark preference and tail suspension tests but not in an open field, elevated plus maze, and forced swim tests at baseline. We next performed spared nerve injury in WT and Tmem97 KO mice to assess the role of Tmem97 in neuropathic pain-induced anxiety and depression. WT mice, but not Tmem97 KO mice, developed a prolonged neuropathic pain-induced depressive-like phenotype when tested 10â weeks after nerve injury in females. Our results show that Tmem97 plays a role in modulating anxiety-like and depressive-like behaviors in naive animals with a significant change in the presence of nerve injury in female mice. Overall, these data demonstrate that Tmem97 could be a target to alleviate affective comorbidities of pain disorders.
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Depresión , Proteínas de la Membrana , Ratones Endogámicos C57BL , Ratones Noqueados , Neuralgia , Receptores sigma , Animales , Femenino , Ratones , Ansiedad/metabolismo , Conducta Animal/fisiología , Depresión/metabolismo , Depresión/etiología , Modelos Animales de Enfermedad , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Neuralgia/metabolismo , Receptores sigma/metabolismoRESUMEN
Sigma receptors (SRs), including SR1 and SR2 subtypes, have attracted increasing interest in recent years due to their involvement in a wide range of activities, including the modulation of opioid analgesia, neuroprotection, and potential anticancer activity. In this context, haloperidol (HAL), a commonly used antipsychotic drug, also possesses SR activity and cytotoxic effects. Herein, we describe the identification of novel SR ligands, obtained by a chemical hybridization approach. There wereendowed with pan-affinity for both SR subtypes and evaluated their potential anticancer activity against SH-SY5Y and HUH-7 cancer cell lines. Through a chemical hybridization approach, we identified novel compounds (4d, 4e, 4g, and 4j) with dual affinity for SR1 and SR2 receptors. These compounds were subjected to cytotoxicity testing using a resazurin assay. The results revealed potent cytotoxic effects against both cancer cell lines, with IC50 values comparable to HAL. Interestingly, the cytotoxic potency of the novel compounds resembled that of the SR1 antagonist HAL rather than the SR2 agonist siramesine (SRM), indicating the potential role of SR1 antagonism in their mechanism of action. The further exploration of their structure-activity relationships and their evaluation in additional cancer cell lines will elucidate their therapeutic potential and may pave the way for the development of novel anticancer agents that target SRs.
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Antineoplásicos , Diseño de Fármacos , Haloperidol , Receptores sigma , Receptores sigma/metabolismo , Receptores sigma/antagonistas & inhibidores , Haloperidol/farmacología , Haloperidol/análogos & derivados , Humanos , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Relación Estructura-Actividad , Estructura Molecular , Supervivencia Celular/efectos de los fármacos , Ligandos , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos AntitumoralesRESUMEN
Sigma-2-ligands (S2L) are characterized by high binding affinities to their cognate sigma-2 receptor, overexpressed in rapidly proliferating tumor cells. As such, S2L were developed as imaging probes (ISO1) or as cancer therapeutics, alone (SV119 [C6], SW43 [C10]) and as delivery vehicles for cytotoxic drug cargoes (C6-Erastin, C10-SMAC). However, the exact mechanism of S2L-induced cytotoxicity remains to be fully elucidated. A series of high-affinity S2L were evaluated regarding their cytotoxicity profiles across cancer cell lines. While C6 and C10 displayed distinct cytotoxicities, C0 and ISO1 were essentially non-toxic. Confocal microscopy and lipidomics analysis in cellular and mouse models revealed that C10 induced increases in intralysosomal free cholesterol and in cholesterol esters, suggestive of unaltered intracellular cholesterol trafficking. Cytotoxicity was caused by cholesterol excess, a phenomenon that contrasts the effects of NPC1 inhibition. RNA-sequencing revealed gene clusters involved in cholesterol homeostasis and ER stress response exclusively by cytotoxic S2L. ER stress markers were confirmed by qPCR and their targeted modulation inhibited or enhanced cytotoxicity of C10 in a predicted manner. Moreover, C10 increased sterol regulatory element-binding protein 2 (SREBP2) and low-density lipoprotein receptor (LDLR), both found to be pro-survival factors activated by ER stress. Furthermore, inhibition of downstream processes of the adaptive response to S2L with simvastatin resulted in synergistic treatment outcomes in combination with C10. Of note, the S2L conjugates retained the ER stress response of the parental ligands, indicative of cholesterol homeostasis being involved in the overall cytotoxicity of the drug conjugates. Based on these findings, we conclude that S2L-mediated cell death is due to free cholesterol accumulation that leads to ER stress. Consequently, the cytotoxic profiles of S2L drug conjugates are proposed to be enhanced via concurrent ER stress inducers or simvastatin, strategies that could be instrumental on the path toward tumor eradication.
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Colesterol , Estrés del Retículo Endoplásmico , Receptores sigma , Colesterol/metabolismo , Receptores sigma/metabolismo , Receptores sigma/genética , Humanos , Animales , Ratones , Estrés del Retículo Endoplásmico/efectos de los fármacos , Ligandos , Línea Celular Tumoral , Muerte Celular/efectos de los fármacos , Neoplasias/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/patologíaRESUMEN
The synthesis and pharmacological activity of a new series of thieno[2,3-d]pyrimidin-4(3H)-one derivatives as sigma-1 receptor (σ1R) ligands are reported. A hit from a high-throughput screening program was evolved into a highly potent and selective σ1R agonist (14qR) that contains a free NH group as positive ionizable moiety, not fulfilling the usual pharmacophoric features of the σ1R. The compound shows good physicochemical and ADMET characteristics, displays an agonist profile in the binding immunoglobulin protein/σ1R association assay, induces neuron viability in an in vitro model of ß-amyloid peptide intoxication, and presents positive results against recognition memory impairment induced by hippocampal injection of Aß peptide in rats after oral treatment, altogether making 14qR (WLB-87848) an interesting candidate for neuroprotection.
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Fármacos Neuroprotectores , Receptores sigma , Receptor Sigma-1 , Animales , Receptores sigma/agonistas , Receptores sigma/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/química , Ratas , Humanos , Masculino , Relación Estructura-Actividad , Péptidos beta-Amiloides/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Pirimidinas/farmacología , Pirimidinas/síntesis química , Pirimidinas/química , Trastornos de la Memoria/tratamiento farmacológico , Supervivencia Celular/efectos de los fármacos , Pirimidinonas/farmacología , Pirimidinonas/síntesis química , Pirimidinonas/química , Ratas Wistar , Hipocampo/efectos de los fármacos , Hipocampo/metabolismoRESUMEN
Prion diseases are invariably fatal neurodegenerative diseases of humans and other animals for which there are no effective treatment options. Previous work from our laboratory identified phenethylpiperidines as a novel class of anti-prion compounds. While working to identify the molecular target(s) of these molecules, we unexpectedly discovered ten novel antiprion compounds based on their known ability to bind to the sigma receptors, σ1R and σ2R, which are currently being tested as therapeutic or diagnostic targets for cancer and neuropsychiatric disorders. Surprisingly, however, knockout of the respective genes encoding σ1R and σ2R (Sigmar1 and Tmem97) in prion-infected N2a cells did not alter the antiprion activity of these compounds, demonstrating that these receptors are not the direct targets responsible for the antiprion effects of their ligands. Further investigation of the most potent molecules established that they are efficacious against multiple prion strains and protect against downstream prion-mediated synaptotoxicity. While the precise details of the mechanism of action of these molecules remain to be determined, the present work forms the basis for further investigation of these compounds in preclinical studies. Given the therapeutic utility of several of the tested compounds, including rimcazole and haloperidol for neuropsychiatric conditions, (+)-pentazocine for neuropathic pain, and the ongoing clinical trials of SA 4503 and ANAVEX2-73 for ischemic stroke and Alzheimer's disease, respectively, this work has immediate implications for the treatment of human prion disease.
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Enfermedades por Prión , Receptores sigma , Receptores sigma/metabolismo , Receptores sigma/efectos de los fármacos , Animales , Ligandos , Enfermedades por Prión/tratamiento farmacológico , Enfermedades por Prión/metabolismo , Ratones , Humanos , Priones/efectos de los fármacos , Priones/metabolismo , Receptor Sigma-1 , Línea Celular TumoralRESUMEN
Alzheimer's disease (AD) is the most common cause of dementia worldwide. Due to its uncertain pathogenesis, there is currently no treatment available for AD. Increasing evidences have linked cellular senescence to AD, although the mechanism triggering cellular senescence in AD requires further exploration. To investigate the involvement of cellular senescence in AD, we explored the effects of cadmium chloride (CdCl2) exposure, one of the potential environmental risk factors for AD, on neuron senescence in vivo and in vitro. ß-amyloid (Aß) and tubulin-associated protein (tau) pathologies were found to be enhanced by CdCl2 exposure in the in vitro models, while p53/p21/Rb cascade-related neuronal senescence pathways were activated. Conversely, the use of melatonin, a cellular senescence inhibitor, or a cadmium ion chelator suppressed CdCl2-induced neuron senescence, along with the Aß and tau pathologies. Mechanistically, CdCl2 exposure activated the suppressor enhancer Lin-12/Notch 1-like (SEL1L)/HMG-CoA reductase degradation 1 (HRD1)-regulated endoplasmic reticulum-associated degradation (ERAD), which enhanced the ubiquitin degradation of sigma-1 receptor (SigmaR1) by specifically recognizing its K142 site, resulting in the activation of the p53/p21/Rb pathway via the induction of Ca2+ dyshomeostasis and mitochondrial dysfunction. In the in vivo models, the administration of the SigmaR1 agonist ANAVEX2-73 rescues neurobehavioral inhibition and alleviates cellular senescence and AD-like pathology in the brain tissue of CdCl2-exposed mice. Consequently, the present study revealed a novel senescence-associated regulatory route for the SEL1L/HRD1/SigmaR1 axis that affects the pathological progression of CdCl2 exposure-associated AD. CdCl2 exposure activated SEL1L/HRD1-mediated ERAD and promoted the ubiquitinated degradation of SigmaR1, activating p53/p21/Rb pathway-regulated neuronal senescence. The results of the present study suggest that SigmaR1 may function as a neuroprotective biomarker of neuronal senescence, and pharmacological activation of SigmaR1 could be a promising intervention strategy for AD therapy.
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Cloruro de Cadmio , Senescencia Celular , Degradación Asociada con el Retículo Endoplásmico , Neuronas , Receptores sigma , Animales , Senescencia Celular/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Cloruro de Cadmio/toxicidad , Receptores sigma/metabolismo , Degradación Asociada con el Retículo Endoplásmico/efectos de los fármacos , Péptidos beta-Amiloides/metabolismo , Ratones , Proteínas tau/metabolismo , Masculino , Enfermedad de Alzheimer/metabolismo , Humanos , Melatonina/farmacología , Ratones Endogámicos C57BLRESUMEN
AlphaFold2 (AF2) models have had wide impact but mixed success in retrospective ligand recognition. We prospectively docked large libraries against unrefined AF2 models of the σ2 and serotonin 2A (5-HT2A) receptors, testing hundreds of new molecules and comparing results with those obtained from docking against the experimental structures. Hit rates were high and similar for the experimental and AF2 structures, as were affinities. Success in docking against the AF2 models was achieved despite differences between orthosteric residue conformations in the AF2 models and the experimental structures. Determination of the cryo-electron microscopy structure for one of the more potent 5-HT2A ligands from the AF2 docking revealed residue accommodations that resembled the AF2 prediction. AF2 models may sample conformations that differ from experimental structures but remain low energy and relevant for ligand discovery, extending the domain of structure-based drug design.