Efficacy and safety of perioperative melatonin for postoperative delirium in patients undergoing surgery: a systematic review and meta-analysis.

OBJECTIVE: To assess the efficacy and safety of perioperative melatonin and melatonin agonists in preventing postoperative delirium (POD). METHODS: We conducted a systematic search for randomized controlled trials (RCTs) published through December 2022. The primary outcome was efficacy based on the incidence of POD (POD-I). Secondary outcomes included efficacy and safety according to the length of hospital or intensive care unit stay, in-hospital mortality, and adverse events. Subgroup analyses of POD-I were based on the type and dose of drug (low- and high-dose melatonin, ramelteon), the postoperative period (early or late), and the type of surgery. RESULTS: In the analysis (16 RCTs, 1981 patients), POD-I was lower in the treatment group than in the control group (risk ratio [RR] = 0.57). POD-I was lower in the high-dose melatonin group than in the control group (RR = 0.41), whereas no benefit was observed in the low-dose melatonin and ramelteon groups. POD-I was lower in the melatonin group in the early postoperative period (RR = 0.35) and in patients undergoing cardiopulmonary surgery (RR = 0.54). CONCLUSION: Perioperative melatonin or melatonin agonist treatment suppressed POD without severe adverse events, particularly at higher doses, during the early postoperative period, and after cardiopulmonary surgery.

Managing non-24-hour sleep-wake rhythm disorder with ramelteon in a 12-year-old girl with Pierre Robin sequence and developmental delay: a case report.

The author recently observed a case involving a 12-year-old sighted girl who exhibited symptoms typical of non-24-hour sleep-wake rhythm disorder (N24SWD). This disorder, more commonly found in blind individuals, presents a unique challenge when diagnosed in those with vision. Several interventions can be attempted, ranging from behavioral adjustments to light therapy. Although melatonin has been noted for its effectiveness in realigning the patient's sleep-wake cycle, the use of ramelteon, a melatonin receptor agonist, has seldom been reported in managing N24SWD. However, this case illuminates the potential of ramelteon as another therapeutic option for sighted individuals with N24SWD. Further study is suggested to determine the potential of ramelteon in managing this disorder among sighted individuals of varying age groups. CITATION: Huang C-H. Managing non-24-hour sleep-wake rhythm disorder with ramelteon in a 12-year-old girl with Pierre Robin sequence and developmental delay: a case report. J Clin Sleep Med. 2024;20(6):995-997.

Therapeutic potential of MCC950, a specific inhibitor of NLRP3 inflammasome in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder with a pathogenesis that remains incompletely understood, resulting in limited treatment options. MCC950, a highly specific NLRP3 inflammasome inhibitor, effectively suppresses the activation of NLRP3, thus reducing the production of caspase-1, the pro-inflammatory cytokines IL-1ß and IL-18. This review highlights the pivotal role of NLRP3 inflammasome activation pathways in the pathogenesis of SLE and discusses the potential therapeutic application of MCC950 in SLE. Notably, it comprehensively elucidates the mechanism of MCC950 targeting the NLRP3 pathway in SLE treatment, outlining its potential role in regulating autophagy and necroptosis. The insights gained contribute to a deeper understanding of the value of MCC950 in SLE therapy, serving as a robust foundation for further research and potential clinical applications.

MCC950 alleviates seizure severity and angiogenesis by inhibiting NLRP3/ IL-1ß signaling pathway-mediated pyroptosis in mouse model of epilepsy.

Epilepsy is one of the most common serious chronic brain disorders, affecting up to 70 million people worldwide. Vascular disruption, including blood-brain barrier impairment and pathological angiogenesis, exacerbates its occurrence. However, its underlying mechanisms remain elusive. MCC950 is a specific small-molecule inhibitor that selectively blocks NLRP3 inflammatory vesicle activation across the blood-brain barrier, limits downstream IL-1ß maturation and release, and exerts therapeutic effects across multiple diseases. In the present study, an epilepsy model was established by intraperitoneal administration of Kainic acid to adult male C57BL/6J wild-type mice. The results revealed that the epilepsy susceptibility of MCC950-treated mice was decreased, and neural damage following seizure episodes was reduced. In addition, immunofluorescence staining, RT-qPCR, and Western blot demonstrated that MCC950 inhibited the expression of the NLRP3 inflammasome and its related proteins in microglia, whereas microangiogenesis was found to be increased in the cerebral cortex and hippocampus of epileptic mice, and these effects could be reversed by MCC950. Furthermore, neurobehavioral impairment was observed in the epileptic mouse model, and MCC950 similarly alleviated the aforementioned pathological process. To the best of our knowledge, this is the first study to establish that pathological microangiogenesis is associated with NLRP3/IL-1ß signaling pathway activation in a Kainic acid-induced epilepsy mouse model and that MCC950 administration attenuates the above-mentioned pathological changes and exerts neuroprotective effects. Therefore, MCC950 is a promising therapeutic agent for the treatment of epilepsy.

Apparent resolution of hypersomnia episodes in two patients with Kleine-Levin syndrome following treatment with the melatonin receptor agonist ramelteon.

Kleine-Levin syndrome (KLS) is a rare disorder characterized by episodic bouts of severe hypersomnia associated with cognitive and behavioral abnormalities and normal alertness and functioning in between episodes. The pathophysiology is unclear but may involve neurotransmitter abnormalities, hypothalamic/thalamic dysfunction, viral/autoimmune etiology, or circadian abnormalities. No single treatment has been shown to be reliably efficacious; lithium has demonstrated the most consistent efficacy, although many do not respond and its use is limited by side effects. Due to the evidence of circadian involvement, we hypothesized that strengthening circadian signals may ameliorate symptoms. Ramelteon is a potent melatonin receptor agonist. In this report, two patients with KLS are described with apparent resolution of hypersomnia episodes following ramelteon initiation. CITATION: Dominguez D, Rudock R, Tomko S, Pathak S, Mignot E, Licis A. Apparent resolution of hypersomnia episodes in two patients with Kleine-Levin syndrome following treatment with the melatonin receptor agonist ramelteon. J Clin Sleep Med. 2024;20(4):657-662.

Efficacy of melatonin and ramelteon for the acute and long-term management of insomnia disorder in adults: A systematic review and meta-analysis.

Melatonin has gained growing interest as a treatment of insomnia, despite contradictory findings, and a low level of evidence. A systematic review and meta-analysis was conducted following PRISMA criteria, to assess the efficacy of melatonin and ramelteon compared with placebo on sleep quantity and quality in insomnia disorder, while also considering factors that may impact their efficacy. This review included 22 studies, with 4875 participants, including 925 patients treated with melatonin, 1804 treated with ramelteon and 2297 receiving a placebo. Most studies evaluated the acute efficacy of prolonged release (PR) melatonin in insomnia disorder. Compared with placebo, PR melatonin appears efficacious with a small to medium effect size on subjective sleep onset latency (sSOL) (p = 0.031; weighted difference = -6.30 min), objective sleep onset latency (oSOL) (p < 0.001; weighted difference = -5.05 min), and objective sleep efficiency (oSE) (p = 0.043; weighted difference = 1.91%). For the subgroup mean age of patients ≥55, PR melatonin was efficacious on oSE with a large effect size (p < 0.001; weighted difference = 2.95%). Ramelteon was efficacious with a large effect size at 4 weeks on objective total sleep time (oTST) (p = 0.010; weighted difference = 17.9 min), subjective total sleep time (sTST) (p = 0.006; weighted difference = 11.7 min), sSOL (p = 0.009; weighted difference = -8.74 min), and oSOL (p = 0.017; weighted difference = -14 min). Regarding long-term effects, ramelteon has a large effect size on oTST (p < 0.001; weighted difference = 2.02 min) and sTST (p < 0.001; weighted difference = 14.5 min). PR melatonin and ramelteon appear efficacious compared with placebo for insomnia symptoms with PR melatonin showing mostly small to medium effect sizes. PR melatonin for individuals with a mean age ≥ 55 and ramelteon show larger effect sizes.

Melatonin and Ramelteon for the treatment of delirium: A systematic review and meta-analysis.

OBJECTIVE: To assess the efficacy of melatonin and melatonergic agonist for the treatment of delirium in hospitalized patients. METHODS: Embase, MEDLINE, PsycINFO, PubMed, CENTRAL, Cochrane Database of Systematic Reviews, TRIP Medical Database, ClinicalTrials.gov and Google were searched from inception to October 2022. Randomized controlled trials (RCT) and observational studies with any type of comparator evaluating melatonin or melatonergic agonist (ramelteon) enrolling any populations (ICU, surgery, geriatric) were included. Two reviewers independently selected and extracted data using the Cochrane risk of bias tools (RoB2 and ROBINSI). RESULTS: Out of the 650 screened publications, three RCTs and six observational studies were included (n = 1211). All three RCTs compared melatonin to placebo, as the majority of observational studies compared melatonin or ramelteon to antipsychotics. Two RCTs reported the duration of delirium and a meta-analysis provided a statistical difference between melatonin and placebo (-1.72 days, 95% CI -2.66 to -0.77, p = 0.0004). Five observational studies reported the duration of delirium but only one reported a statistical reduction in the duration of delirium. CONCLUSION: Although melatonin and ramelteon may be effective treatments for delirium, particularly to shorten the duration of delirium and to limit the use of rescue medication, current data is limited in number and in its quality. Clinicians should wait until higher quality data from ongoing RCTs are available before prescribing melatonin to delirious patients.

Prophylactic Use of Ramelteon for Delirium in Hospitalized Patients: A Systematic Review and Meta-Analyses.

BACKGROUND: Small prospective studies, case reports, as well as some randomized placebo-controlled trials and previous meta-analyses have shown that ramelteon, a melatonin agonist, may reduce the risk of developing delirium. OBJECTIVE: The goal of this systemic review and meta-analyses was to assess the current evidence supporting the use of ramelteon in delirium prevention by including data from larger (>100 subjects) and more recent trials since the most recent meta-analyses were published in 2019. There were no exclusions for trial size, age, ramelteon dose, length of treatment, or hospital setting. METHODS: Medline, Embase, PsycINFO, EBM Reviews, Scopus, and Web of Science databases were queried using the search terms delirium (with subterms including prevention and control), ramelteon, Rozerem, or melatonin receptor agonists, for English-language publications until March 16, 2021. Randomized placebo-controlled trials of hospitalized subjects receiving ramelteon for delirium prevention were included. The primary outcome of interest was delirium incidence. Odds ratios of the risk of developing incident delirium and 95% confidence intervals were calculated using a random effects model. RESULTS: A total of 177 articles were identified by the literature search. Five studies (n = 443, 53.7% male) met criteria for inclusion in the final meta-analyses. The meta-analyses of the randomized placebo-controlled trials revealed that ramelteon did not result in a reduction in the risk of incident delirium (n = 443; odds ratio = 0.49; 95% confidence interval = 0.13-1.85). A moderate degree of heterogeneity was noted among the studies (I2 = 53%). CONCLUSIONS: Current evidence suggests that ramelteon is ineffective as a prophylactic drug in reducing the incidence of delirium in hospitalized patients.

Ultra-low-dose early night ramelteon administration for the treatment of delayed sleep-wake phase disorder: case reports with a pharmacological review.

Delayed sleep-wake phase disorder (DSWPD) is a common circadian sleep-wake phase disorders brings serious social impairment of the patients. Melatonin is the main medication option; however, it has not been approved in some countries, and over-the-counter melatonin is under poor quality control. The melatonin receptor agonist ramelteon might be a potential treatment option, but there are few reports regarding its use in DSWPD patients. Existing pharmacological and chronobiological studies suggest that an ultra-low dose of ramelteon in the early night is beneficial for DSWPD. Here, we present our clinical experience together with a pharmacological review and discussion. Twenty-three DSWPD patients, of whom 18 patients had a treatment history of a normal dose of ramelteon, were prescribed low-dose ramelteon (median: 0.571 mg, 1/14 of a tablet) to be taken in the early night (mean: 18:10). After the treatment, the mean sleep schedule was significantly advanced, and clinical symptoms were improved. CITATION: Shimura A, Kanno T, Inoue T. Ultra-low-dose early night ramelteon administration for the treatment of delayed sleep-wake phase disorder: case reports with a pharmacological review. J Clin Sleep Med. 2022;18(12):2861-2865.

Suvorexant with or without ramelteon to prevent delirium: a systematic review and meta-analysis.

Delirium is a common and serious neurobehavioral syndrome, associated with prolonged hospital stays, and increased morbidity and mortality. As it remains unclear whether suvorexant with or without ramelteon prevents delirium in elderly hospitalized patients, we conducted a systematic review and meta-analysis to evaluate, searching the PubMed, Cochrane Library, Web of Science, EMBASE, and EBSCOhost databases for all randomized controlled trials (RCTs), case-control studies, and cohort studies that investigated the effects of suvorexant with or without ramelteon on delirium in adult hospitalized patients. The primary outcome was the incidence of delirium. Two randomized controlled trials, 7 cohort studies and 2 case-control studies involving 2594 patients were included in this meta-analysis. The results showed that both suvorexant alone (odds ratio (OR) = 0.30, 95% confidence interval (CI): 0.14-0.65, P = 0.002) and suvorexant with ramelteon (OR = 0.39, 95% CI 0.23-0.65, P = 0.0003) reduced the incidence of delirium in adult hospitalized patients. Six studies involved the use of benzodiazepines; subgroup analysis performed separately in the suvorexant alone and suvorexant with ramelteon groups indicated that when benzodiazepine was administered, suvorexant with ramelteon was effective at reducing the incidence of delirium (OR = 0.53, 95% CI 0.37-0.74, P = 0.0002), but no significant difference was observed for suvorexant alone (OR = 0.40, 95% CI 0.11-1.53, P = 0.18). The current literature thus supports the effectiveness of suvorexant with or without ramelteon for delirium prevention, although suvorexant alone failed to significantly reduce the incidence of delirium when benzodiazepine was administered. The present study was limited by the significant heterogeneity among the included studies, and caution should be exercised when interpreting the results. This study was registered in the PROSPERO database (CRD4202017964).

Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease.

BACKGROUND: Patients with von Hippel-Lindau (VHL) disease have a high incidence of renal cell carcinoma owing to VHL gene inactivation and constitutive activation of the transcription factor hypoxia-inducible factor 2α (HIF-2α). METHODS: In this phase 2, open-label, single-group trial, we investigated the efficacy and safety of the HIF-2α inhibitor belzutifan (MK-6482, previously called PT2977), administered orally at a dose of 120 mg daily, in patients with renal cell carcinoma associated with VHL disease. The primary end point was objective response (complete or partial response) as measured according to the Response Evaluation Criteria in Solid Tumors, version 1.1, by an independent central radiology review committee. We also assessed responses to belzutifan in patients with non-renal cell carcinoma neoplasms and the safety of belzutifan. RESULTS: After a median follow-up of 21.8 months (range, 20.2 to 30.1), the percentage of patients with renal cell carcinoma who had an objective response was 49% (95% confidence interval, 36 to 62). Responses were also observed in patients with pancreatic lesions (47 of 61 patients [77%]) and central nervous system hemangioblastomas (15 of 50 patients [30%]). Among the 16 eyes that could be evaluated in 12 patients with retinal hemangioblastomas at baseline, all (100%) were graded as showing improvement. The most common adverse events were anemia (in 90% of the patients) and fatigue (in 66%). Seven patients discontinued treatment: four patients voluntarily discontinued, one discontinued owing to a treatment-related adverse event (grade 1 dizziness), one discontinued because of disease progression as assessed by the investigator, and one patient died (of acute toxic effects of fentanyl). CONCLUSIONS: Belzutifan was associated with predominantly grade 1 and 2 adverse events and showed activity in patients with renal cell carcinomas and non-renal cell carcinoma neoplasms associated with VHL disease. (Funded by Merck Sharp and Dohme and others; MK-6482-004 ClinicalTrials.gov number, NCT03401788.).

Belzutifan, a Potent HIF2α Inhibitor, in the Pacak-Zhuang Syndrome.

The integration of genomic testing into clinical care enables the use of individualized approaches to the management of rare diseases. We describe the use of belzutifan, a potent and selective small-molecule inhibitor of the protein hypoxia-inducible factor 2α (HIF2α), in a patient with polycythemia and multiple paragangliomas (the Pacak-Zhuang syndrome). The syndrome was caused in this patient by somatic mosaicism for an activating mutation in EPAS1. Treatment with belzutifan led to a rapid and sustained tumor response along with resolution of hypertension, headaches, and long-standing polycythemia. This case shows the application of a targeted therapy for the treatment of a patient with a rare tumor-predisposition syndrome. (Funded by the Morin Family Fund for Pediatric Cancer and Alex's Lemonade Stand Foundation.).

Belzutifan: First Approval.

Belzutifan (Welireg™) is an oral small molecule inhibitor of hypoxia-inducible factor (HIF)-2α being developed by Peloton Therapeutics for the treatment of solid tumours, including renal cell carcinoma (RCC) with clear cell histology (ccRCC) and von Hippel-Lindau (VHL) disease-associated RCC. In August 2021, belzutifan received its first approval in the USA for the treatment of patients with VHL disease who require therapy for associated RCC, central nervous system (CNS) haemangioblastomas or pancreatic neuroendocrine tumours (pNET), not requiring immediate surgery. Clinical studies of belzutifan (as monotherapy or combination therapy) in other indications, including ccRCC, pNET and phaeochromocytoma/paraganglioma, are also underway in various countries. This article summarizes the milestones in the development of belzutifan leading to this first approval for certain VHL disease-associated tumours.

Hepatic and Vascular Vitamin K Status in Patients with High Cardiovascular Risk.

Vitamin K dependent proteins (VKDP), such as hepatic coagulation factors and vascular matrix Gla protein (MGP), play key roles in maintaining physiological functions. Vitamin K deficiency results in inactive VKDP and is strongly linked to vascular calcification (VC), one of the major risk factors for cardiovascular morbidity and mortality. In this study we investigated how two vitamin K surrogate markers, dephosphorylated-undercarboxylated MGP (dp-ucMGP) and protein induced by vitamin K absence II (PIVKA-II), reflect vitamin K status in patients on hemodialysis or with calcific uremic arteriolopathy (CUA) and patients with atrial fibrillation or aortic valve stenosis. Through inter- and intra-cohort comparisons, we assessed the influence of vitamin K antagonist (VKA) use, vitamin K supplementation and disease etiology on vitamin K status, as well as the correlation between both markers. Overall, VKA therapy was associated with 8.5-fold higher PIVKA-II (0.25 to 2.03 AU/mL) and 3-fold higher dp-ucMGP (843 to 2642 pM) levels. In the absence of VKA use, non-renal patients with established VC have dp-ucMGP levels similar to controls (460 vs. 380 pM), while in HD and CUA patients, levels were strongly elevated (977 pM). Vitamin K supplementation significantly reduced dp-ucMGP levels within 12 months (440 to 221 pM). Overall, PIVKA-II and dp-ucMGP showed only weak correlation (r2 ≤ 0.26) and distinct distribution pattern in renal and non-renal patients. In conclusion, VKA use exacerbated vitamin K deficiency across all etiologies, while vitamin K supplementation resulted in a vascular VKDP status better than that of the general population. Weak correlation of vitamin K biomarkers calls for thoughtful selection lead by the research question. Vitamin K status in non-renal deficient patients was not anomalous and may question the role of vitamin K deficiency in the pathogenesis of VC in these patients.

Blockade of the NLRP3/caspase-1 axis attenuates ketamine-induced hippocampus pyroptosis and cognitive impairment in neonatal rats.

BACKGROUND: Multiple studies have revealed that repeated or long-term exposure to ketamine causes neurodegeneration and cognitive dysfunction. Pyroptosis is an inflammatory form of programmed cell death that has been linked to various neurological diseases. However, the role of NLRP3/caspase-1 axis-related pyroptosis in ketamine-induced neurotoxicity and cognitive dysfunction remains uncertain. METHODS: To evaluate whether ketamine caused NLRP3/caspase1-dependent pyroptosis, flow cytometry analysis, western blotting, ELISA test, histopathological analysis, Morris water maze (MWM) test, cell viability assay, and lactate dehydrogenase release (LDH) assay were carried out on PC12 cells, HAPI cells, and 7-day-old rats. In addition, the NLRP3 inhibitor MCC950 or the caspase-1 inhibitor VX-765 was used to investigate the role of the NLRP3/caspase-1 axis in ketamine-induced neurotoxicity and cognitive dysfunction. RESULTS: Our findings demonstrated that ketamine exposure caused cell damage and increased the levels of pyroptosis in PC12 cells, HAPI cells, and the hippocampus of neonatal rats. After continuous exposure to ketamine, targeting NLRP3 and caspase-1 with MCC950 or VX765 improved pyroptosis, reduced neuropathological damages, and alleviated cognitive dysfunction. CONCLUSION: NLRP3/Caspase-1 axis-dependent pyroptosis is involved in ketamine-induced neuroinflammation and cognitive dysfunction, and it provides a promising strategy to treat ketamine-related neurotoxicity.

The selective NLRP3 inhibitor MCC950 hinders atherosclerosis development by attenuating inflammation and pyroptosis in macrophages.

NLRP3 inflammasome is a vital player in macrophages pyroptosis, which is a type of proinflammatory cell-death and takes part in the pathogenesis of atherosclerosis. In this study, we used apoE-/- mice and ox-LDL induced THP-1 derived macrophages to explore the mechanisms of MCC950, a selective NLRP3 inhibitor in treating atherosclerosis. For the in vivo study, MCC950 was intraperitoneal injected to 8-week-old apoE-/- mice fed with high-fat diet for 12 weeks. For the in vitro study, THP-1 derived macrophages were treated with ox-LDL and MCC950 for 48 h. MCC950 administration reduced plaque areas and macrophages contents, but did not improve the serum lipid profiles in aortic root of apoE-/- mice. MCC950 inhibited the activation of NLRP3/ASC/Caspase-1/GSDMD-N axis, and alleviated macrophages pyroptosis and the production of IL-1ß and IL-18 both in aorta and in cell lysates. However, MCC950 did not affect the expression of TLR4 or the mRNA levels of NLRP3 inflammasome and its downstream proteins, suggesting that MCC950 had no effects on the priming of NLRP3 inflammasome activation in macrophages. The anti-atherosclerotic mechanisms of MCC950 on attenuating macrophages inflammation and pyroptosis involved in inhibiting the assembly and activation of NLRP3 inflammasome, rather than interrupting its priming.

Is antivitamin K reversal required in patients with cirrhosis undergoing liver transplantation?

BACKGROUND: Antivitamin K agent (AVK) reversal in patients with cirrhosis awaiting liver transplantation (LT) is not defined in guidelines. We investigated the effect of reversion with prothrombin complex concentrate (PCC) on intraoperative transfusion, bleeding, and safety in LT patients on AVK. STUDY DESIGN AND METHODS: In 511 patients undergoing LT, we identified 25 patients treated with AVK (AVK group) and 13 patients with incidental portal vein thrombosis (PVT) without AVK (incidental PVT group). Fifty patients who underwent LT without PVT or AVK matched by age, model for end stage of liver disease (MELD), body mass index (BMI), and cirrhosis etiology were selected as the control group. RESULTS: There were no significant differences between the three groups in intraoperative blood loss, transfusion, and postoperative bleeding. In the AVK group, there were no differences between patients who received PCC and those who did not in intraoperative blood loss, red blood cells, fibrinogen, and platelet transfusion, or postoperative bleeding. PCC use had no effect on RBC transfusion in patients who had international normalized ratio or clotting time above versus below median values of the two parameters at baseline (2.3 and 103 s, respectively). No thrombotic events were detected in patients who received PCC. DISCUSSION: These data suggest that systematic administration of PCC to revert AVK prior to LT should be reconsidered.

Selective Inhibition of NLRP3 Inflammasome Reverses Pressure Overload-Induced Pathological Cardiac Remodeling by Attenuating Hypertrophy, Fibrosis, and Inflammation.

Activation of the NLRP3 inflammasome promotes pathological cardiac remodeling induced by pressure overload. However, the therapeutic effects of NLRP3 inhibition after cardiac remodeling remain unknown. The present study aimed to investigate whether the selective NLRP3 inhibitor, MCC950, could reverse transverse aortic constriction (TAC)-induced cardiac remodeling. Mice were divided into four groups based on the treatment given: sham, sham + MCC950, TAC, and TAC + MCC950. MCC950 (10 mg/kg, intraperitoneal injection, once per day) was administered from two weeks after TAC or sham surgery for four weeks. Echocardiography, histological analysis, RT-PCR, and Western blotting were performed to explore the function of MCC950 after TAC. We found that MCC950 reversed cardiac dysfunction after TAC. MCC950 attenuated cardiac hypertrophy by down-regulating calcineurin expression and inhibiting MAPK activation. Further, it also alleviated cardiac fibrosis post-TAC by inhibiting the TGF-ß/Smad4 pathway, and reduced cardiac inflammation and macrophage infiltration post-TAC, including both M1 and M2 macrophages. Taken together, MCC950 can attenuate cardiac remodeling due to pressure overload by inhibiting hypertrophy, fibrosis, and inflammation. Our study provides a basis for the clinical application of NLRP3 inhibitors in the treatment of non-ischemic heart failure.

Protective effect of combination of anakinra and MCC950 against acute lung injury is achieved through suppression of the NF-κB-mediated-MAPK and NLRP3-caspase pathways.

BACKGROUND: It has been uncovered that the interleukin-1 receptor antagonist anakinra and the NLRP3 inflammasome blocker MCC950 can alleviate acute lung injury (ALI). However, the specific mechanism underlying these effects remains unknown. Thus, we sought to investigate the effects of anakinra and MCC950 in ALI as well as the molecular mechanisms. METHODS: We treated C57BL/6 mice with aerosols of anakinra and/or MCC950 along with lipopolysaccharide (LPS), followed by mechanical ventilation (MV) treatment after 1.5 h of inhalation of aforementioned compounds. Lung injury was assessed by determining the level of inflammatory factors in the alveolar lavage fluid and monitoring blood oxygen saturation. We confirmed our findings of regulation of the ALI model through the nuclear factor-κB (NF-κB)/mitogen-activated protein kinase (MAPK)/nucleotide binding domain and leucine-rich repeat (NLR) pyrin domain containing 3 (NLRP3)-caspase pathway in further studies with RelA-/- mice. RESULTS: Combined treatment of anakinra and MCC950 presented the best therapeutic effect on LPS and MV-induced ALI than did treatment with anakinra or MCC950 alone. Combined therapy with anakinra and MCC950 suppressed MAPK and NLRP3-caspase via inhibition of the NF-κB pathway to improve ALI, but the therapeutic pathway was revoked by knockout of NF-κB. CONCLUSION: Taken together, combined treatment of anakinra and MCC950 was effective in alleviating ALI in the mouse model, highlighting a new insight into ALI treatment.