scholarly journals Leptin Signaling in the Ovary of Diet-Induced Obese Mice Regulates Activation of NOD-Like Receptor Protein 3 Inflammasome

2021 ◽  
Vol 9 ◽  
Author(s):  
Marek Adamowski ◽  
Karolina Wołodko ◽  
Joana Oliveira ◽  
Juan Castillo-Fernandez ◽  
Daniel Murta ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Maternal Obesity ◽  
Leptin Resistance ◽  
Receptor Protein ◽  
Chow Diet ◽  
Inflammasome Activation ◽  
Leptin Signaling ◽  
Nlrp3 Inflammasome Activation

Obesity leads to ovarian dysfunction and the establishment of local leptin resistance. The aim of our study was to characterize the levels of NOD-like receptor protein 3 (NLRP3) inflammasome activation in ovaries and liver of mice during obesity progression. Furthermore, we tested the putative role of leptin on NLRP3 regulation in those organs. C57BL/6J female mice were treated with equine chorionic gonadotropin (eCG) or human chorionic gonadotropin (hCG) for estrous cycle synchronization and ovary collection. In diet-induced obesity (DIO) protocol, mice were fed chow diet (CD) or high-fat diet (HFD) for 4 or 16 weeks, whereas in the hyperleptinemic model (LEPT), mice were injected with leptin for 16 days (16 L) or saline (16 C). Finally, the genetic obese leptin-deficient ob/ob (+/? and −/−) mice were fed CD for 4 week. Either ovaries and liver were collected, as well as cumulus cells (CCs) after superovulation from DIO and LEPT. The estrus cycle synchronization protocol showed increased protein levels of NLRP3 and interleukin (IL)-18 in diestrus, with this stage used for further sample collections. In DIO, protein expression of NLRP3 inflammasome components was increased in 4 week HFD, but decreased in 16 week HFD. Moreover, NLRP3 and IL-1β were upregulated in 16 L and downregulated in ob/ob. Transcriptome analysis of CC showed common genes between LEPT and 4 week HFD modulating NLRP3 inflammasome. Liver analysis showed NLRP3 protein upregulation after 16 week HFD in DIO, but also its downregulation in ob/ob−/−. We showed the link between leptin signaling and NLRP3 inflammasome activation in the ovary throughout obesity progression in mice, elucidating the molecular mechanisms underpinning ovarian failure in maternal obesity.

scholarly journals Leptin Signalling in the Ovary of Diet-Induced Obese Mice Regulates Activation of Nod-Like Receptor Protein 3 Inflammasome

2021 ◽  
Author(s):  
Marek Adamowski ◽  
Karolina Wolodko ◽  
Joana Oliveira ◽  
Juan Castillo-Fernandez ◽  
Daniel Murta ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Maternal Obesity ◽  
Cumulus Cells ◽  
Leptin Resistance ◽  
Receptor Protein ◽  
Chow Diet ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

Obesity leads to ovarian dysfunction and the establishment of local leptin resistance. The aim of our study was to characterise levels of Nod-Like Receptor Protein 3 (NLRP3) inflammasome activation during obesity progression in the mouse ovaries and liver and test the putative role of leptin on its regulation. C57BL/6J mice were treated with equine chorionic gonadotropin (eCG) or human chorionic gonadotropin (hCG) for oestrous cycle synchronisation and ovaries collection. In diet-induced obesity (DIO) model, mice were fed chow diet (CD) or high fat diet (HFD) for 4 or 16 weeks (wk), whereas in hyperleptinemic model (LEPT), mice were injected with leptin for 16 days (16L) or saline (16C) and in the genetic obese leptin-deficient ob/ob (+/? and -/-) animals were fed CD for 4wk. Either ovaries and liver were collected, as well as cumulus cells (CCs) after superovulation from DIO and LEPT. In DIO protocol, protein expression of NLRP3 inflammasome components was increased in 4wk HFD, but decreased in 16wk HFD. Moreover LEPT and ob/ob models revealed NLRP3 and IL-1b; upregulation in 16L and downregulation in ob/ob. Transcriptome analysis of CC showed common genes between LEPT and 4wk HFD modulating NLRP3 inflammasome. Moreover analysis in the liver showed upregulation of NLRP3 protein only after 16wk HFD, but also the downregulation of NLRP3 protein in ob/ob-/-. We showed the link between leptin signalling and NLRP3 inflammasome activation in the ovary throughout obesity progression in mice, elucidating the molecular mechanisms underpinning ovarian failure in maternal obesity.

scholarly journals Progesterone Attenuates Stress-Induced NLRP3 Inflammasome Activation and Enhances Autophagy Following Ischemic Brain Injury

2020 ◽  
Vol 21 (11) ◽  
pp. 3740 ◽  
Author(s):  
Claudia Espinosa-Garcia ◽  
Fahim Atif ◽  
Seema Yousuf ◽  
Iqbal Sayeed ◽  
Gretchen N. Neigh ◽  
...  
Keyword(s):  
Brain Injury ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Global Ischemia ◽  
Inflammasome Activation ◽  
Ischemic Brain Injury ◽  
Primary Microglia ◽  
Ischemic Brain ◽  
Nlrp3 Inflammasome Activation ◽  
The Impact

NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome inhibition and autophagy induction attenuate inflammation and improve outcome in rodent models of cerebral ischemia. However, the impact of chronic stress on NLRP3 inflammasome and autophagic response to ischemia remains unknown. Progesterone (PROG), a neuroprotective steroid, shows promise in reducing excessive inflammation associated with poor outcome in ischemic brain injury patients with comorbid conditions, including elevated stress. Stress primes microglia, mainly by the release of alarmins such as high-mobility group box-1 (HMGB1). HMGB1 activates the NLRP3 inflammasome, resulting in pro-inflammatory interleukin (IL)-1β production. In experiment 1, adult male Sprague-Dawley rats were exposed to social defeat stress for 8 days and then subjected to global ischemia by the 4-vessel occlusion model, a clinically relevant brain injury associated with cardiac arrest. PROG was administered 2 and 6 h after occlusion and then daily for 7 days. Animals were killed at 7 or 14 days post-ischemia. Here, we show that stress and global ischemia exert a synergistic effect in HMGB1 release, resulting in exacerbation of NLRP3 inflammasome activation and autophagy impairment in the hippocampus of ischemic animals. In experiment 2, an in vitro inflammasome assay, primary microglia isolated from neonatal brain tissue, were primed with lipopolysaccharide (LPS) and stimulated with adenosine triphosphate (ATP), displaying impaired autophagy and increased IL-1β production. In experiment 3, hippocampal microglia isolated from stressed and unstressed animals, were stimulated ex vivo with LPS, exhibiting similar changes than primary microglia. Treatment with PROG reduced HMGB1 release and NLRP3 inflammasome activation, and enhanced autophagy in stressed and unstressed ischemic animals. Pre-treatment with an autophagy inhibitor blocked Progesterone’s (PROG’s) beneficial effects in microglia. Our data suggest that modulation of microglial priming is one of the molecular mechanisms by which PROG ameliorates ischemic brain injury under stressful conditions.

scholarly journals Distinct Molecular Mechanisms Underlying Potassium Efflux for NLRP3 Inflammasome Activation

2020 ◽  
Vol 11 ◽  
Author(s):  
Ziwei Xu ◽  
Zi-mo Chen ◽  
Xiaoyan Wu ◽  
Linjie Zhang ◽  
Ying Cao ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Inflammasome Activation ◽  
Potassium Efflux ◽  
Pannexin 1 ◽  
Nlrp3 Inflammasome Activation ◽  
K2p Channels ◽  
Pore Forming Proteins ◽  
Molecular Patterns

The NLRP3 inflammasome is a core component of innate immunity, and dysregulation of NLRP3 inflammasome involves developing autoimmune, metabolic, and neurodegenerative diseases. Potassium efflux has been reported to be essential for NLRP3 inflammasome activation by structurally diverse pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs). Thus, the molecular mechanisms underlying potassium efflux to activate NLRP3 inflammasome are under extensive investigation. Here, we review current knowledge about the distinction channels or pore-forming proteins underlying potassium efflux for NLRP3 inflammasome activation with canonical/non-canonical signaling or following caspase-8 induced pyroptosis. Ion channels and pore-forming proteins, including P2X7 receptor, Gasdermin D, pannexin-1, and K2P channels involved present viable therapeutic targets for NLRP3 inflammasome related diseases.

scholarly journals Role of NLRP3 inflammasome in the development of bladder pain syndrome interstitial cystitis

2019 ◽  
Vol 11 ◽  
pp. 175628721881803 ◽  
Author(s):  
Karol Borys Tudrej ◽  
Tomasz Piecha ◽  
Małgorzata Kozłowska-Wojciechowska
Keyword(s):  
Interstitial Cystitis ◽  
Nlrp3 Inflammasome ◽  
Pain Syndrome ◽  
Bladder Pain Syndrome ◽  
Receptor Protein ◽  
Inflammasome Activation ◽  
Bladder Epithelium ◽  
Bladder Pain ◽  
Bladder Inflammation ◽  
Nlrp3 Inflammasome Activation

Although it has been proposed that NOD-like receptor protein 3 (NLRP3) inflammasome activation may have an important contribution to the onset of bladder pain syndrome/interstitial cystitis (BPS/IC), as of today there is still insufficient evidence to accept or to reject this hypothesis. However, taking into consideration that inflammasomes have been already shown as important mediators of cyclophosphamide-induced bladder inflammation and that some studies have also revealed human bladder epithelium expresses high levels of NLRP3, such a hypothesis seems to be reasonable. The purpose of this review is to discuss a scenario that NLRP3 inflammasome is a crucial player in the development of this disease. Identification of a novel mediator of bladder inflammation and pain could lead to emerging new therapeutic strategy and the first causative therapy.

scholarly journals NLRP3 inflammasome activation contributes to remifentanil-induced postoperative hyperalgesia via regulation of NMDA receptor NR1 subunit phosphorylation and GLT-1

2020 ◽  
Author(s):  
Yuan Yuan ◽  
Chenxu Wang ◽  
Beibei Dong ◽  
Keliang Xie ◽  
Yonghao Yu
Keyword(s):  
Spinal Cord ◽  
Nmda Receptor ◽  
Nlrp3 Inflammasome ◽  
Receptor Protein ◽  
Inflammasome Activation ◽  
Remifentanil Infusion ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation ◽  
Behavioural Tests ◽  
Inflammasome Inhibitors

Abstract Background Although remifentanil provides perfect analgesia during operations, postoperative remifentanil-induced hyperalgesia (RIH) might be a challenge to anaesthetists. Increasingly, the NOD-like receptor protein 3 (NLRP3) signalling pathway are being implicated in the initiation and maintenance of these conditions. In the present work, we examined the hypothesis that NLRP3 inflammasome activation contributes to RIH via regulation of NMDA receptor NR1 subunit phosphorylation and glutamate transporter-1 (GLT-1) by interleukin-1β (IL-1β). Methods We first tested the changes in thermal and mechanical hyperalgesia at baseline (24 h before remifentanil infusion) and 2 h, 6 h, 24 h, and 48 h after remifentanil infusion in a rat model of incisional pain. Then, the expression of IL-1β and GLT-1 and phosphorylation of NMDA receptor NR1 subunits (Phospho-NR1) in the L4–L6 spinal cord segments were measured. Furthermore, we investigated the effects of IL-1ra, a selective IL-1β inhibitor, on behavioural tests of RIH and on the expression of GLT-1 and Phospho-NR1. In addition, we measured the expression of TLR4, P2X7R, NLRP3 and caspase-1, which are indicators of NLRP3 inflammasome activation. Finally, we investigated the effects of (+)-naloxone (a TLR4 inhibitor), A438079 (a P2X7R inhibitor) and ac-YVADcmk (a caspase-1 inhibitor), which are all selective NLRP3 inflammasome inhibitors, on behavioural tests of RIH and on the expression of IL-1β, GLT-1 and Phospho-NR1. Results The initiation and maintenance of RIH was mediated by a previously unidentified mechanism--namely, remifentanil-induced spinal NLRP3 inflammasome activation and the associated release of IL-1β. Remifentanil induced significant postoperative hyperalgesia, as indicated by behavioural tests, which were markedly improved by pretreatment with IL-1ra and NLRP3 inflammasome inhibitors. Moreover, remifentanil infusion decreased the expression of GLT-1 and increased Phospho-NR1 in the spinal cord, which were reversed by pretreatment with IL-1ra and NLRP3 inflammasome inhibitors. More importantly, remifentanil infusion increased IL-1β expression and activated NLRP3 inflammasomes, which were significantly attenuated by NLRP3 inflammasome inhibitors. Conclusion The above results suggest that NLRP3 inflammasome activation contributes to RIH via regulation of Phospho-NR1 and GLT-1 by IL-1β. Inhibition of NLRP3 inflammasome activation or IL-1β may be an effective and novel option for the treatment of RIH.

scholarly journals Modulation of RAS and PI3-AKT pathway by Stavudine (d4T) in PBMC of Alzheimer’s Disease Patients

2020 ◽  
Author(s):  
Francesca La Rosa ◽  
Chiara Paola Zoia ◽  
Chiara Bazzini ◽  
Alessandra Bolognini ◽  
Saresella Marina ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Beclin 1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammasome Activation ◽  
Beneficial Effects ◽  
Nlrp3 Inflammasome Activation ◽  
Chaperone Mediated Autophagy ◽  
Inflammasome Activity

Abstract Background Aβ42-deposition plays a pivotal role in AD-pathogenesis by inducing the activation of microglial cells and neuroinflammation. This process is antagonized by microglia-mediated clearance of Aβ plaques. Activation of the NLRP3 inflammasome is involved in neuroinflammation and in the impairments of Aβ-plaques clearance. Stavudine (d4T) on the other hand down-regulates the NLRP3 inflammasome and stimulates autophagy-mediated Aβ-clearing in a TPH-1 cell line model. Methods We explored the effect of d4T on Aβ- autophagy using PBMC of AD patients that were primed with LPS and stimulated with Aβ in the absence/presence of d4T. We analyzed the NLRP3 inflammasome activity by measuring NLRP3-ASC complexes formation by AMNIS Flow-sight and pro-inflammatory cytokines (IL-1β, IL-18 and Caspase-1) production by enzyme-linked immunosorbent assay (ELISA). Western blot analyses were used to measure phosphorylation and protein expression of p38, CREB, ERK and AKT, p70, LAMP 2A, beclin-1 and Bax. Results data showed that d4T: 1) down regulates NLRP3 inflammasome activation and the production of down-stream proinflammatory cytokines even in PBMC; 2) stimulates the phosphorylation of AKT, ERK, p70 as well as LAMP2A production, but does modulate beclin-1, suggesting a selective effect of this compound on chaperone-mediated autophagy (CMA); 3) up regulates p-CREB and BAX, possibly diminishing Aβ–mediated cytotoxicity; and 4) reduces the phosphorylation of p-38, a protein involved in the production of proinflammatory cytokines. Conclusions d4T reduces the activation of the NLRP3 inflammasome and stimulates CMA autophagy as well as molecular mechanisms that modulate cytotoxicity and reduce inflammation in cells of AD patients. It might be interesting to verify the possibly beneficial effects of d4T in the clinical scenario.

scholarly journals Tetrandrine alleviates cerebral ischemia/reperfusion injury by suppressing NLRP3 inflammasome activation via Sirt-1

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9042
Author(s):  
Jun Wang ◽  
Ming Guo ◽  
Ruojia Ma ◽  
Maolin Wu ◽  
Yamei Zhang
Keyword(s):  
Cerebral Ischemia ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Sirtuin 1 ◽  
Neurological Deficits ◽  
Inflammasome Activation ◽  
Cerebral Ischemia Reperfusion ◽  
Nlrp3 Inflammasome Activation

Background & Aims Tetrandrine (Tet) has been reported to have anti-inflammatory effects and protect from the ischemic strokes. The NLRP3 inflammasome plays a key role in cerebral ischemia/reperfusion (I/R)-induced inflammatory lesions. However, the molecular mechanisms of Tet related to the progression of cerebral ischemia are still unclear. Therefore, the aim of this study was to investigate the possible effects of Tet on cerebral ischemia and the related mechanisms involved in NLRP3 inflammasome. Methods C57BL/6J mice used as a cerebral I/R injury model underwent middle cerebral artery occlusion (MCAO) for 2 h following reperfusion for 24 h. Tet (30 mg/kg/day, i.p.) was administered for seven days and 30 min before and after MCAO. Their brain tissues were evaluated for NLRP3 inflammasome and Sirtuin-1 (Sirt-1) expression. An intracerebroventricular injection of Sirt-1 siRNA was administered to assess the activation of the NLRP3 inflammasome. Results Tet significantly reduced the neurological deficits, infarction volume, and cerebral water content in MCAO mice. Moreover, it inhibited I/R-induced over expression of NLRP3, cleaved caspase-1, interleukin (IL)-1β, IL-18, and Sirt-1. Sirt-1 knockdown with siRNA greatly blocked the Tet-induced reduction of neurological severity score and infarct volume, and reversed the inhibition of NLRP3 inflammasome activation. Conclusion Our results demonstrate that Tet has benefits for cerebral I/R injury, which are partially related to the suppression of NLRP3 inflammasome activation via upregulating Sirt-1.

scholarly journals Koumine Suppresses IL-1β Secretion and Attenuates Inflammation Associated With Blocking ROS/NF-κB/NLRP3 Axis in Macrophages

2021 ◽  
Vol 11 ◽  
Author(s):  
Yufei Luo ◽  
Bojun Xiong ◽  
Haiping Liu ◽  
Zehong Chen ◽  
Huihui Huang ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Diseases ◽  
Inhibitory Effect ◽  
Receptor Protein ◽  
Mechanistic Study ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Underlying Mechanisms

Koumine (KM), one of the primary constituents of Gelsemium elegans, has been used for the treatment of inflammatory diseases such as rheumatoid arthritis, but whether KM impacts the activation of the NOD-like receptor protein 3 (NLRP3) inflammasome remains unknown. This study aimed to explore the inhibitory effect of KM on NLRP3 inflammasome activation and the underlying mechanisms both in vitro using macrophages stimulated with LPS plus ATP, nigericin or monosodium urate (MSU) crystals and in vivo using an MSU-induced peritonitis model. We found that KM dose-dependently inhibited IL-1β secretion in macrophages after NLRP3 inflammasome activators stimulation. Furthermore, KM treatment efficiently attenuated the infiltration of neutrophils and suppressed IL-1β production in mice with MSU-induced peritonitis. These results indicated that KM inhibited NLRP3 inflammasome activation, and consistent with this finding, KM effectively inhibited caspase-1 activation, mature IL-1β secretion, NLRP3 formation and pro-IL-1β expression in LPS-primed macrophages treated with ATP, nigericin or MSU. The mechanistic study showed that, KM exerted a potent inhibitory effect on the NLRP3 priming step, which decreased the phosphorylation of IκBα and p65, the nuclear localization of p65, and the secretion of TNF-α and IL-6. Moreover, the assembly of NLRP3 was also interrupted by KM. KM blocked apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and its oligomerization and hampered the NLRP3-ASC interaction. This suppression was attributed to the ability of KM to inhibit the production of reactive oxygen species (ROS). In support of this finding, the inhibitory effect of KM on ROS production was completely counteracted by H2O2, an ROS promoter. Our results provide the first indication that KM exerts an inhibitory effect on NLRP3 inflammasome activation associated with blocking the ROS/NF-κB/NLRP3 signal axis. KM might have potential clinical application in the treatment of NLRP3 inflammasome-related diseases.

scholarly journals Parkin-Dependent Mitophagy is Required for the Inhibition of ATF4 on NLRP3 Inflammasome Activation in Cerebral Ischemia-Reperfusion Injury in Rats

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 897 ◽  
Author(s):  
He ◽  
Li ◽  
Meng ◽  
Wu ◽  
Zhao ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Nlrp3 Inflammasome ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Receptor Protein ◽  
Inflammasome Activation ◽  
Nissl Staining ◽  
Male Adult ◽  
Cerebral Ischemia Reperfusion ◽  
Nlrp3 Inflammasome Activation

Background: Nod-like receptor protein 3 (NLRP3) inflammasome is a crucial contributor in the inflammatory process during cerebral ischemia/reperfusion (I/R) injury. ATF4 plays a pivotal role in the pathogenesis of cerebral I/R injury, however, its function and underlying mechanism are not fully characterized yet. In the current study, we examined whether ATF4 ameliorates cerebral I/R injury by inhibiting NLRP3 inflammasome activation and whether mitophagy is involved in this process. In addition, we explored the role of parkin in ATF4-mediated protective effects. Method: To address these issues, healthy male adult Sprague-Dawley rats were exposed to middle cerebral artery occlusion for 1 h followed by 24 h reperfusion. Adeno-associated virus (AAV) and siRNA were injected into rats to overexpress and knockdown ATF4 expression, respectively. After pretreatment with AAV, mdivi-1(mitochondrial division inhibitor-1) was injected into rats to block mitophagy activity. Parkin expression was knockdown using specific siRNA after AAV pretreatment. Result: Data showed that ATF4 overexpression induced by AAV was protective against cerebral I/R injury, as evidenced by reduced cerebral infraction volume, decreased neurological scores and improved outcomes of HE and Nissl staining. In addition, overexpression of ATF4 gene was able to up-regulate Parkin expression, enhance mitophagy activity and inhibit NLRP3 inflammasome-mediated inflammatory response. ATF4 knockdown induced by siRNA resulted in the opposite effects. Furthermore, ATF4-mediated inhibition of NLRP3 inflammasome activation was strongly affected by mitophagy blockage upon mdivi-1 injection. Besides, ATF4-mediated increase of mitophagy activity and inhibition of NLRP3 inflammasome activation were effectively reversed by Parkin knockdown using siRNA. Conclusion: Our study demonstrated that ATF4 is able to alleviate cerebral I/R injury by suppressing NLRP3 inflammasome activation through parkin-dependent mitophagy activity. These results may provide a new strategy to relieve cerebral I/R injury by modulating mitophagy-NLRP3 inflammasome axis.

Sign in / Sign up

Export Citation Format

Share Document