RESUMEN
The pathogenesis mechanism of acute gastric mucosal lesions (AGML) is still unclear; further exploration is urgently needed to find a new therapeutic target. This study aimed to investigate whether morphine might regulate the expression and function of transient receptor potential ankyrin 1 (TRPA1) through a cyclic adenosine monophosphate/protein kinase A (cAMP/PKA)-dependent pathway, thereby alleviating gastric mucosal lesions caused by water-immersion restraint stress (WIRS). Rats were administered with intrathecal morphine, TRPA1 antagonist (HC-030031), µ-opioid receptor antagonist, or protein kinase A inhibitor (H-89), respectively, before WIRS. After 6 hours of WIRS, microscopic lesions, hematoxylin and eosin staining, and transmission electron microscopy were applied to assess the damage of the gastric mucosa. Real-time polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay were conducted to detect the levels of TRPA1 and substance P (SP) in the dorsal root ganglia (DRG) and gastric tissues. In addition, immunofluorescence was used to explore the possible co-expression of TRPA1 and µ-opioid receptors in the DRG. The results indicated that WIRS upregulated TRPA1 and SP in gastric mucosa, and HC-030031 or H-89 could alleviate gastric mucosal lesions caused by WIRS (P < .0001). Morphine was found to suppress both WIRS-induced gastric mucosal lesions (P < .0001) and the upregulation of TRPA1 (P = .0086) and SP (P = .0013). Both TRPA1 and SP play important roles in the pathogenesis of WIRS-induced AGML. Exogenous gastroprotective strategies reduce elevated levels of TRPA1 via the cAMP/PKA-dependent pathway. Inhibition of TRPA1 upregulation in the DRG is critical for intrathecal morphine preconditioning-induced gastric protection.
Asunto(s)
Ganglios Espinales , Mucosa Gástrica , Isoquinolinas , Morfina , Ratas Sprague-Dawley , Restricción Física , Canal Catiónico TRPA1 , Regulación hacia Arriba , Animales , Morfina/farmacología , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Canal Catiónico TRPA1/metabolismo , Masculino , Ganglios Espinales/metabolismo , Ganglios Espinales/efectos de los fármacos , Restricción Física/efectos adversos , Ratas , Isoquinolinas/farmacología , Acetanilidas/farmacología , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Purinas/farmacología , Estrés Psicológico/complicaciones , Inmersión , Receptores Opioides mu/metabolismo , AMP Cíclico/metabolismo , SulfonamidasRESUMEN
Postoperative ileus (POI) is the cessation or reduction of gastrointestinal (GI) motility after surgery. Reactive enteric glial cells (EGCs) are critical for maintaining bowel function. However, the triggering mechanisms and downstream effects of reactive EGCs in POI were poorly understood. The goal of this current study was to investigate whether the inducible nitric oxide synthase (iNOS)-driven reactive EGCs participated in GI motility disorders and mechanisms underlying altered GI motility in POI. Intestinal manipulation (IM)-induced POI mice and iNOS-/- mice were used in the study. Longitudinal muscle and myenteric plexuses (LMMPs) from the distal small intestine were stained by immunofluorescence. Our results found that the GI motility disorders occurred in the IM-induced POI mice, and reactive EGCs were observed in LMMPs. Glial metabolic inhibitor gliotoxin fluorocitrate (FC) treatment or iNOS gene knockout attenuated GI motility dysfunction. In addition, we also found that FC treatment or iNOS gene knockout significantly inhibited the fluorescence intensity macrophage colony-stimulating factor (M-CSF), which reduced M2 phenotype macrophages activation in LMMPs of IM-induced POI mice. Our findings demonstrated that iNOS-driven reactive EGCs played a key role and were tightly linked to the MMs homeostasis in the POI mice. EGCs are emerging as a new frontier in neurogastroenterology and a potential therapeutic target.
Asunto(s)
Ileus , Ratones , Animales , Óxido Nítrico Sintasa de Tipo II/metabolismo , Ileus/metabolismo , Motilidad Gastrointestinal/fisiología , Neuroglía/metabolismo , Intestino Delgado/metabolismoRESUMEN
OBJECTIVES: General anesthesia results in a state of unconsciousness that is similar to sleep. In recent years, increasing evidence has reported that astrocytes play a crucial role in regulating sleep. However, whether astrocytes are involved in general anesthesia is unknown. METHODS: In the present study, the designer receptors exclusively activated by designer drugs (DREADDs) approach was utilized to specifically activate astrocytes in the basal forebrain (BF) and observed its effect on isoflurane anesthesia. One the other side, L-α-aminoadipic acid was used to selectively inhibit astrocytes in the BF and investigated its influence on isoflurane-induced hypnotic effect. During the anesthesia experiment, cortical electroencephalography (EEG) signals were recorded as well. RESULTS: The chemogenetic activation group had a significantly shorter isoflurane induction time, longer recovery time, and higher delta power of EEG during anesthesia maintenance and recovery periods than the control group. Inhibition of astrocytes in the BF delayed isoflurane-induced loss of consciousness, promoted recovery, decreased delta power and increased beta and gamma power during maintenance and recovery periods. CONCLUSIONS: The present study suggests that astrocytes in the BF region are involved in isoflurane anesthesia and may be a potential target for regulating the consciousness state of anesthesia.
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Prosencéfalo Basal , Isoflurano , Ratones , Animales , Isoflurano/farmacología , Estado de Conciencia , Astrocitos , Inconsciencia , Anestesia GeneralRESUMEN
BACKGROUND: Activation of substance P (SP) contributes to the development and maintenance of gastric lesions, but the mechanisms underlying the release of SP and SP-mediated damage to the gastric mucosa remain unknown. Transient receptor potential ankyrin 1 (TRPA1) is expressed in SP-positive neurons in the dorsal root ganglion (DRG) and stomach of rats. We hypothesized that water immersion restraint stress (WIRS) may activate and sensitize TRPA1 in DRG neurons, subsequently inducing the release of SP from DRG and stomach cells, causing the development of acute gastric mucosal lesions (AGML). METHODS: Changes in TRPA1 and SP expression in T8-11 DRG sensory neurons and the stomach in an AGML rat model were determined by reverse transcription polymerase chain reaction, western blotting and immunohistochemistry. The SP levels of serum and gastric mucosa were measured by using an enzyme-linked immunosorbent assay (ELISA). Gastric lesions were evaluated by histopathological changes. The TRPA1 antagonist HC-030031 and TRPA1 agonists allyl isothiocyanate were used to verify effect of TRPA1 and SP on AGML. RESULTS: SP and TRPA1 in the DRG and stomach were upregulated, and the serum and gastric mucosa levels of SP were increased after WIRS, which are closely associated with AGML. The release of SP was suppressed and AGML were alleviated following a selective TRPA1 antagonist HC-030031. TRPA1 agonists AITC increased release of SP and led to moderate gastric lesions. We confirmed that WIRS induced the release of SP in the DRG, stomach, serum and gastric mucosa, and in a TRPA1-dependent manner. CONCLUSIONS: Upregulated SP and TRPA1 in the DRG and stomach and increased serum and gastric mucosa SP levels may contribute to stress-induced AGML. TRPA1 is a potential drug target to reduce stress-induced AGML development in patients with acute critical illnesses. This study may contribute to the discovery of drugs for AGML treatment.
Asunto(s)
Ganglios Espinales/metabolismo , Úlcera Gástrica/patología , Estrés Psicológico/psicología , Sustancia P/metabolismo , Canal Catiónico TRPA1/metabolismo , Acetanilidas/farmacología , Animales , Modelos Animales de Enfermedad , Ganglios Espinales/citología , Ganglios Espinales/efectos de los fármacos , Mucosa Gástrica/inervación , Mucosa Gástrica/patología , Humanos , Isotiocianatos/farmacología , Masculino , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Purinas/farmacología , Ratas , Ratas Wistar , Úlcera Gástrica/sangre , Úlcera Gástrica/psicología , Estrés Psicológico/etiología , Sustancia P/sangre , Canal Catiónico TRPA1/agonistas , Canal Catiónico TRPA1/antagonistas & inhibidoresRESUMEN
Microglial activation is involved in a variety of neurological disorders, and overactivated microglial cells can secrete large amount of proinflammatory factors and induce neuron death. Therefore, reducing microglial activation is believed to be useful in treating the disorders. In this study, we used 10 ng/ml lipopolysaccharide plus 10 U/ml interferon γ (LPS/IFNγ) to induce N9 microglial activation and explored resveratrol- (RSV-) induced effects on microglial activation and the underlying mechanism. We found that LPS/IFNγ exposure for 24 h increased inducible nitric oxide synthase (iNOS) and nuclear factor κB (NF-κB) p65 subunit expressions in the cells and enhanced tumor necrosis factor α (TNF-α) and interleukin 1ß (IL-1ß) releases from the cells. RSV of 25 µM reduced the iNOS and NF-κB p65 subunit expressions and the proinflammatory factors' releases; the knockdown of silent information regulator factor 2-related enzyme 1 (SIRT1) or suppressor of cytokine signaling 1 (SOCS1) by using the small interfering RNA, however, significantly abolished the RSV-induced effects on iNOS and NF-κB p65 subunit expressions and the proinflammatory factors' releases. These findings showed that microglial SIRT1-SOCS1 pathway may mediate the RSV-induced inhibition of microglial activation in the LPS/IFNγ-treated N9 microglia.
RESUMEN
Toll-like receptors (TLRs) belong to the category of pattern recognition receptor. The binding of TLRs with their respective ligands activates innate immune system, thereby initiates adaptive immune responses. As such, some TLR ligands or agonists have been used as an adjuvant component in a variety of vaccine formulations. AMA1 and MSP1 from Plasmodium falciparum are two main antigens of malaria blood-stage vaccine, but they are poor immunogens in humans. To enhance the immunogenicities of these two vaccine candidates, the TLR agonists have been used in their formulations for the clinical trials. Recent progress in the field is reviewed in this article.