ABSTRACT
As an important sensor in the innate immune system, NLRP3 detects exogenous pathogenic invasions and endogenous cellular damage and responds by forming the NLRP3 inflammasome, a supramolecular complex that activates caspase-1. The three major components of the NLRP3 inflammasome are NLRP3, which captures the danger signals and recruits downstream molecules; caspase-1, which elicits maturation of the cytokines IL-1ß and IL-18 and processing of gasdermin D to mediate cytokine release and pyroptosis; and ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain), which functions as a bridge connecting NLRP3 and caspase-1. In this article, we review the structural information that has been obtained on the NLRP3 inflammasome and its components or subcomplexes, with special focus on the inactive NLRP3 cage, the active NLRP3-NEK7 (NIMA-related kinase 7)-ASC inflammasome disk, and the PYD-PYD and CARD-CARD homotypic filamentous scaffolds of the inflammasome. We further implicate structure-derived mechanisms for the assembly and activation of the NLRP3 inflammasome.
Subject(s)
Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Humans , Animals , Inflammasomes/chemistry , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Apoptosis , Cytokines/metabolism , Caspase 1/metabolism , Interleukin-1beta/metabolismABSTRACT
Inflammasomes are inflammatory signaling complexes that provide molecular platforms to activate the protease function of inflammatory caspases. Caspases-1, -4, -5, and -11 are inflammatory caspases activated by inflammasomes to drive lytic cell death and inflammatory mediator production, thereby activating host-protective and pathological immune responses. Here, we comprehensively review the mechanisms that govern the activity of inflammatory caspases. We discuss inflammatory caspase activation and deactivation mechanisms, alongside the physiological importance of caspase activity kinetics. We also examine mechanisms of caspase substrate selection and how inflammasome and cell identities influence caspase activity and resultant inflammatory and pyroptotic cellular programs. Understanding how inflammatory caspases are regulated may offer new strategies for treating infection and inflammasome-driven disease.
Subject(s)
Caspases , Inflammasomes , Animals , Caspase 1/metabolism , Caspases/metabolism , Cell Death , Humans , Inflammasomes/metabolism , PyroptosisABSTRACT
NLRs constitute a large, highly conserved family of cytosolic pattern recognition receptors that are central to health and disease, making them key therapeutic targets. NLRC5 is an enigmatic NLR with mutations associated with inflammatory and infectious diseases, but little is known about its function as an innate immune sensor and cell death regulator. Therefore, we screened for NLRC5's role in response to infections, PAMPs, DAMPs, and cytokines. We identified that NLRC5 acts as an innate immune sensor to drive inflammatory cell death, PANoptosis, in response to specific ligands, including PAMP/heme and heme/cytokine combinations. NLRC5 interacted with NLRP12 and PANoptosome components to form a cell death complex, suggesting an NLR network forms similar to those in plants. Mechanistically, TLR signaling and NAD+ levels regulated NLRC5 expression and ROS production to control cell death. Furthermore, NLRC5-deficient mice were protected in hemolytic and inflammatory models, suggesting that NLRC5 could be a potential therapeutic target.
Subject(s)
Inflammation , Intracellular Signaling Peptides and Proteins , NAD , Animals , Mice , Inflammation/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Intracellular Signaling Peptides and Proteins/genetics , NAD/metabolism , Humans , Immunity, Innate , Mice, Inbred C57BL , Reactive Oxygen Species/metabolism , Mice, Knockout , Signal Transduction , HEK293 Cells , Inflammasomes/metabolism , Apoptosis Regulatory Proteins/metabolism , Apoptosis Regulatory Proteins/genetics , Toll-Like Receptors/metabolism , Male , Cytokines/metabolism , Calcium-Binding ProteinsABSTRACT
Long-term epigenetic reprogramming of innate immune cells in response to microbes, also termed "trained immunity," causes prolonged altered cellular functionality to protect from secondary infections. Here, we investigated whether sterile triggers of inflammation induce trained immunity and thereby influence innate immune responses. Western diet (WD) feeding of Ldlr-/- mice induced systemic inflammation, which was undetectable in serum soon after mice were shifted back to a chow diet (CD). In contrast, myeloid cell responses toward innate stimuli remained broadly augmented. WD-induced transcriptomic and epigenomic reprogramming of myeloid progenitor cells led to increased proliferation and enhanced innate immune responses. Quantitative trait locus (QTL) analysis in human monocytes trained with oxidized low-density lipoprotein (oxLDL) and stimulated with lipopolysaccharide (LPS) suggested inflammasome-mediated trained immunity. Consistently, Nlrp3-/-/Ldlr-/- mice lacked WD-induced systemic inflammation, myeloid progenitor proliferation, and reprogramming. Hence, NLRP3 mediates trained immunity following WD and could thereby mediate the potentially deleterious effects of trained immunity in inflammatory diseases.
Subject(s)
Cellular Reprogramming , Diet, Western , Epigenesis, Genetic , Immunity, Innate , Immunologic Memory , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Adult , Aged , Animals , Cells, Cultured , Female , Humans , Lipoproteins, LDL/metabolism , Male , Mice , Mice, Inbred C57BL , Middle Aged , Myeloid Cells/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Quantitative Trait Loci , Receptors, LDL/geneticsABSTRACT
Inflammasome complexes function as key innate immune effectors that trigger inflammation in response to pathogen- and danger-associated signals. Here, we report that germline mutations in the inflammasome sensor NLRP1 cause two overlapping skin disorders: multiple self-healing palmoplantar carcinoma (MSPC) and familial keratosis lichenoides chronica (FKLC). We find that NLRP1 is the most prominent inflammasome sensor in human skin, and all pathogenic NLRP1 mutations are gain-of-function alleles that predispose to inflammasome activation. Mechanistically, NLRP1 mutations lead to increased self-oligomerization by disrupting the PYD and LRR domains, which are essential in maintaining NLRP1 as an inactive monomer. Primary keratinocytes from patients experience spontaneous inflammasome activation and paracrine IL-1 signaling, which is sufficient to cause skin inflammation and epidermal hyperplasia. Our findings establish a group of non-fever inflammasome disorders, uncover an unexpected auto-inhibitory function for the pyrin domain, and provide the first genetic evidence linking NLRP1 to skin inflammatory syndromes and skin cancer predisposition.
Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Apoptosis Regulatory Proteins/genetics , Carcinoma/genetics , Genetic Predisposition to Disease , Inflammasomes/metabolism , Keratosis/genetics , Skin Neoplasms/genetics , Adaptor Proteins, Signal Transducing/chemistry , Amino Acid Sequence , Apoptosis Regulatory Proteins/chemistry , Carcinoma/pathology , Chromosomes, Human, Pair 17/genetics , Epidermis/pathology , Germ-Line Mutation , Humans , Hyperplasia/genetics , Hyperplasia/pathology , Inflammasomes/genetics , Interleukin-1/metabolism , Keratosis/pathology , NLR Proteins , Paracrine Communication , Pedigree , Protein Domains , Pyrin/chemistry , Signal Transduction , Skin Neoplasms/pathology , SyndromeABSTRACT
Cells of all organisms survey problems during translation elongation, which may happen as a consequence of mRNA aberrations, inefficient decoding, or other sources. In eukaryotes, ribosome-associated quality control (RQC) senses elongation-stalled ribosomes and promotes dissociation of ribosomal subunits. This so-called ribosomal rescue releases the mRNA for degradation and allows 40S subunits to be recycled for new rounds of translation. However, the nascent polypeptide chains remain linked to tRNA and associated with the rescued 60S subunits. As a final critical step in this pathway, the Ltn1/Listerin E3 ligase subunit of the RQC complex (RQCc) ubiquitylates the nascent chain, which promotes clearance of the 60S subunit while simultaneously marking the nascent chain for elimination. Here we review the ribosomal stalling and rescue steps upstream of the RQCc, where one witnesses intersection with cellular machineries implicated in translation elongation, translation termination, ribosomal subunit recycling, and mRNA quality control. We emphasize both recent progress and future directions in this area, as well as examples linking ribosomal rescue with the production of Ltn1-RQCc substrates.
Subject(s)
Protein Biosynthesis , Proteins/metabolism , Ribosomes/metabolism , Animals , Humans , Protein Subunits/metabolism , Substrate Specificity , UbiquitinationABSTRACT
During the translation surveillance mechanism known as ribosome-associated quality control, the ASC-1 complex (ASCC) disassembles ribosomes stalled on the mRNA. Here, we show that there are two distinct classes of stalled ribosome. Ribosomes stalled by translation elongation inhibitors or methylated mRNA are short lived in human cells because they are split by the ASCC. In contrast, although ultraviolet light and 4-nitroquinoline 1-oxide induce ribosome stalling by damaging mRNA, and the ASCC is recruited to these stalled ribosomes, we found that they are refractory to the ASCC. Consequently, unresolved UV- and 4NQO-stalled ribosomes persist in human cells. We show that ribosome stalling activates cell-cycle arrest, partly through ZAK-p38MAPK signaling, and that this cell-cycle delay is prolonged when the ASCC cannot resolve stalled ribosomes. Thus, we propose that the sensitivity of stalled ribosomes to the ASCC influences the kinetics of stall resolution, which in turn controls the adaptive stress response.
Subject(s)
DNA Damage , Ribosomes , Humans , Protein Biosynthesis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Ribosomes/genetics , Ribosomes/metabolismABSTRACT
Several large-scale genome-wide association studies genetically linked IRGM to Crohn's disease and other inflammatory disorders in which the IRGM appears to have a protective function. However, the mechanism by which IRGM accomplishes this anti-inflammatory role remains unclear. Here, we reveal that IRGM/Irgm1 is a negative regulator of the NLRP3 inflammasome activation. We show that IRGM expression, which is increased by PAMPs, DAMPs, and microbes, can suppress the pro-inflammatory responses provoked by the same stimuli. IRGM/Irgm1 negatively regulates IL-1ß maturation by suppressing the activation of the NLRP3 inflammasome. Mechanistically, we show that IRGM interacts with NLRP3 and ASC and hinders inflammasome assembly by blocking their oligomerization. Further, IRGM mediates selective autophagic degradation of NLRP3 and ASC. By suppressing inflammasome activation, IRGM/Irgm1 protects from pyroptosis and gut inflammation in a Crohn's disease experimental mouse model. This study for the first time identifies the mechanism by which IRGM is protective against inflammatory disorders.
Subject(s)
Autophagy , Colitis/metabolism , Colon/metabolism , Crohn Disease/metabolism , GTP-Binding Proteins/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Animals , CARD Signaling Adaptor Proteins/genetics , CARD Signaling Adaptor Proteins/metabolism , Colitis/genetics , Colitis/pathology , Colitis/prevention & control , Colon/pathology , Crohn Disease/genetics , Crohn Disease/pathology , Crohn Disease/prevention & control , Cytokines/genetics , Cytokines/metabolism , Dextran Sulfate , Disease Models, Animal , GTP-Binding Proteins/deficiency , GTP-Binding Proteins/genetics , HEK293 Cells , HT29 Cells , Humans , Inflammasomes/genetics , Inflammation Mediators/metabolism , Mice, Inbred C57BL , Mice, Knockout , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Pyroptosis , Signal Transduction , THP-1 CellsABSTRACT
Intestinal epithelial cells (IECs) form a critical barrier against pathogen invasion. By generation of mice in which inflammasome expression is restricted to IECs, we describe a coordinated epithelium-intrinsic inflammasome response in vivo. This response was sufficient to protect against Salmonella tissue invasion and involved a previously reported IEC expulsion that was coordinated with lipid mediator and cytokine production and lytic IEC death. Excessive inflammasome activation in IECs was sufficient to result in diarrhea and pathology. Experiments with IEC organoids demonstrated that IEC expulsion did not require other cell types. IEC expulsion was accompanied by a major actin rearrangement in neighboring cells that maintained epithelium integrity but did not absolutely require Caspase-1 or Gasdermin D. Analysis of Casp1-/-Casp8-/- mice revealed a functional Caspase-8 inflammasome in vivo. Thus, a coordinated IEC-intrinsic, Caspase-1 and -8 inflammasome response plays a key role in intestinal immune defense and pathology.
Subject(s)
Apoptosis Regulatory Proteins/metabolism , Calcium-Binding Proteins/metabolism , Caspase 1/metabolism , Caspase 8/metabolism , Eicosanoids/metabolism , Epithelial Cells/metabolism , Interleukin-18/metabolism , Neuronal Apoptosis-Inhibitory Protein/metabolism , Animals , Apoptosis Regulatory Proteins/genetics , Calcium-Binding Proteins/genetics , Caspase 1/genetics , Caspase 8/genetics , Enzyme Activation , Enzyme-Linked Immunosorbent Assay , Epithelial Cells/microbiology , Inflammasomes/genetics , Inflammasomes/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Intracellular Signaling Peptides and Proteins , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microscopy, Confocal , Phosphate-Binding Proteins , Salmonella Infections/metabolism , Salmonella Infections/microbiology , Salmonella typhimurium/physiologyABSTRACT
The gut microbiota regulate susceptibility to multiple human diseases. The Nlrp6-ASC inflammasome is widely regarded as a hallmark host innate immune axis that shapes the gut microbiota composition. This notion stems from studies reporting dysbiosis in mice lacking these inflammasome components when compared with non-littermate wild-type animals. Here, we describe microbial analyses in inflammasome-deficient mice while minimizing non-genetic confounders using littermate-controlled Nlrp6-deficient mice and ex-germ-free littermate-controlled ASC-deficient mice that were all allowed to shape their gut microbiota naturally after birth. Careful microbial phylogenetic analyses of these cohorts failed to reveal regulation of the gut microbiota composition by the Nlrp6- and ASC-dependent inflammasomes. Our results obtained in two geographically separated animal facilities dismiss a generalizable impact of Nlrp6- and ASC-dependent inflammasomes on the composition of the commensal gut microbiota and highlight the necessity for littermate-controlled experimental design in assessing the influence of host immunity on gut microbial ecology.
Subject(s)
Apoptosis Regulatory Proteins/metabolism , Bacteria/genetics , Colitis/immunology , Dysbiosis/immunology , Gastrointestinal Microbiome/immunology , Inflammasomes/metabolism , Receptors, Cell Surface/metabolism , Animals , CARD Signaling Adaptor Proteins , Cells, Cultured , Colitis/chemically induced , Colitis/microbiology , Dysbiosis/microbiology , Female , Genetic Background , Immunity, Innate , Mice , Mice, Inbred C57BL , Mice, Knockout , Microbiota , RNA, Ribosomal, 16S/analysis , Receptors, Cell Surface/genetics , Sodium Dodecyl SulfateABSTRACT
Adipose stem cells (ASCs) have multilineage differentiation capacity and hold great potential for regenerative medicine. Compared to bone marrow-derived mesenchymal stem cells (bmMSCs), ASCs are easier to isolate from abundant sources with significantly higher yields. It is generally accepted that bmMSCs show age-related changes in their proliferation and differentiation potentials, whereas this aspect is still controversial in the case of ASCs. In this review, we evaluated the existing data on the effect of donor age on the osteogenic potential of human ASCs. Overall, a poor agreement has been achieved because of inconsistent findings in the previous studies. Finally, we attempted to delineate the possible reasons behind the lack of agreements reported in the literature. ASCs represent a heterogeneous cell population, and the osteogenic potential of ASCs can be influenced by donor-related factors such as age, but also gender, lifestyle, and the underlying health and metabolic state of donors. Furthermore, future studies should consider experimental factors in in vitro conditions, including passaging, cryopreservation, culture conditions, variations in differentiation protocols, and readout methods.
ABSTRACT
BACKGROUND: Retinopathy of prematurity (ROP), which often presents with bronchopulmonary dysplasia (BPD), is among the most common morbidities affecting extremely premature infants and is a leading cause of severe vision impairment in children worldwide. Activations of the inflammasome cascade and microglia have been implicated in playing a role in the development of both ROP and BPD. Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is pivotal in inflammasome assembly. Utilizing mouse models of both oxygen-induced retinopathy (OIR) and BPD, this study was designed to test the hypothesis that hyperoxia induces ASC speck formation, which leads to microglial activation and retinopathy, and that inhibition of ASC speck formation by a humanized monoclonal antibody, IC100, directed against ASC, will ameliorate microglial activation and abnormal retinal vascular formation. METHODS: We first tested ASC speck formation in the retina of ASC-citrine reporter mice expressing ASC fusion protein with a C-terminal citrine (fluorescent GFP isoform) using a BPD model that causes both lung and eye injury by exposing newborn mice to room air (RA) or 85% O2 from postnatal day (P) 1 to P14. The retinas were dissected on P14 and retinal flat mounts were used to detect vascular endothelium with AF-594-conjugated isolectin B4 (IB4) and citrine-tagged ASC specks. To assess the effects of IC100 on an OIR model, newborn ASC citrine reporter mice and wildtype mice (C57BL/6 J) were exposed to RA from P1 to P6, then 75% O2 from P7 to P11, and then to RA from P12 to P18. At P12 mice were randomized to the following groups: RA with placebo PBS (RA-PBS), O2 with PBS (O2-PBS), O2 + IC100 intravitreal injection (O2-IC100-IVT), and O2 + IC100 intraperitoneal injection (O2-IC100-IP). Retinal vascularization was evaluated by flat mount staining with IB4. Microglial activation was detected by immunofluorescence staining for allograft inflammatory factor 1 (AIF-1) and CD206. Retinal structure was analyzed on H&E-stained sections, and function was analyzed by pattern electroretinography (PERG). RNA-sequencing (RNA-seq) of the retinas was performed to determine the transcriptional effects of IC100 treatment in OIR. RESULTS: ASC specks were significantly increased in the retinas by hyperoxia exposure and colocalized with the abnormal vasculature in both BPD and OIR models, and this was associated with increased microglial activation. Treatment with IC100-IVT or IC100-IP significantly reduced vaso-obliteration and intravitreal neovascularization. IC100-IVT treatment also reduced retinal microglial activation, restored retinal structure, and improved retinal function. RNA-seq showed that IC100 treatment corrected the induction of genes associated with angiogenesis, leukocyte migration, and VEGF signaling caused by O2. IC100 also corrected the suppression of genes associated with cell junction assembly, neuron projection, and neuron recognition caused by O2. CONCLUSION: These data demonstrate the crucial role of ASC in the pathogenesis of OIR and the efficacy of a humanized therapeutic anti-ASC antibody in treating OIR mice. Thus, this anti-ASC antibody may potentially be considered in diseases associated with oxygen stresses and retinopathy, such as ROP.
Subject(s)
Oxygen , Retinopathy of Prematurity , Animals , Retinopathy of Prematurity/pathology , Retinopathy of Prematurity/drug therapy , Retinopathy of Prematurity/metabolism , Mice , Antibodies, Monoclonal, Humanized/pharmacology , Mice, Inbred C57BL , Animals, Newborn , Disease Models, Animal , Humans , Hyperoxia/pathology , Hyperoxia/complications , Retina/pathology , Retina/metabolism , Retina/drug effects , CARD Signaling Adaptor Proteins/metabolism , Mice, Transgenic , Retinal Neovascularization/pathology , Retinal Neovascularization/metabolism , Retinal Neovascularization/drug therapy , Microglia/pathology , Microglia/metabolism , Microglia/drug effectsABSTRACT
BACKGROUND: Cardiogenic shock (CS) is characterized by impaired cardiac function, very high mortality, and limited treatment options. The pro-inflammatory signalling during different phases of CS is incompletely understood. METHODS: We collected serum and plasma (N=44) as well as freshly isolated peripheral blood mononuclear cells (PBMC, N=7) of patients with CS complicating acute myocardial infarction on admission and after revascularization (24h, 48h, 72h) and of healthy controls (serum and plasma N=75; PBMC N=12). RESULTS: PBMC of CS patients had increased gene expression of NLRP3, CASP1, PYCARD, IL1B, and IL18 and showed increased rates of pyroptosis (control: 4.7±0.3% vs. 9.9±1.7% in CS patients, p=0.02). Serum interleukin (IL)-1ß levels were increased after revascularization. IL-18 and IL-6 were higher in patients with CS than in healthy controls but comparable before and after revascularization. Pro-inflammatory apoptosis-associated speck-like proteins containing CARD (ASC) specks were elevated in the serum of CS patients on admission and increased after revascularization (admission: 11.1±4.4 specks/µl, after 24h: 19.0±3.9, p=0.02). ASC specks showed a significant association with 30-day mortality in patients with CS (p<0.05). The estimated regression coefficients and odds ratios indicated a positive relationship between ASC specks and mortality (Odds ratio 1.029, 95% CI, 1.000 to 1.072; p=0.02). CONCLUSIONS: Pyroptosis and circulating ASC specks are increased in patients with CS and are particularly induced after reperfusion This underscores their potential role as a biomarker for poor outcomes in CS patients. ASC specks represent promising new therapeutic targets for CS patients with high inflammatory burden.
ABSTRACT
PURPOSE: Cervical screening is used to detect and treat precancers to prevent invasive cancers. However, successful prevention also requires adequate follow-up and treatment of individuals with abnormal screening results. The aim was to investigate demographics, clinical characteristics, and follow-up status for individuals needing colposcopy after an abnormal screening result. METHODS: The STRIDES (Studying Risk to Improve DisparitiES) cohort comprises individuals undergoing cervical cancer screening and management at a Mississippi Health Department or University of Mississippi clinic. Follow-up status, demographics, and clinical data were assessed from electronic health records and, if necessary, patient navigation on individuals identified as needing a colposcopy after an abnormal screening. RESULTS: Of the 1,458 individuals requiring colposcopy, 43.0% had the procedure within 4 months, 16.4% had a delayed procedure, and 39.5% had no documented colposcopy follow-up, with significant predictors of follow-up identified as age and cytology diagnosis. Individuals 30 + were more likely to have follow up with a colposcopy compared to individuals < 30 years (49% and 38.7%, respectively; p < .001). Individuals with cytology diagnoses of LSIL (52.9%), ASC-H (51.4%), and HSIL (62.3%) had higher percentages of adherence to follow-up guidelines (p < .001). In total, we found that 78% of individuals had some type of follow-up, including a repeat screening visit. CONCLUSION: Despite high cervical cancer screening rates among Mississippians, a substantial proportion did not have adequate next-step intervention. However, it is encouraging that highest risk individuals were more likely to have a colposcopy. Regardless, continuing to understand the underlying causes for incomplete follow-up is crucial for timely secondary targeted interventions to reduce cervical cancer burden, promote awareness, and improve health outcomes.
ABSTRACT
BACKGROUND: Diabetic cardiomyopathy (DCM) is a crucial complication of long-term chronic diabetes that can lead to myocardial hypertrophy, myocardial fibrosis, and heart failure. There is increasing evidence that DCM is associated with pyroptosis, a form of inflammation-related programmed cell death. Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor ß superfamily, which regulates oxidative stress, inflammation, and cell survival to mitigate myocardial hypertrophy, myocardial infarction, and vascular injury. However, the role of GDF11 in regulating pyroptosis in DCM remains to be elucidated. This research aims to investigate the role of GDF11 in regulating pyroptosis in DCM and the related mechanism. METHODS AND RESULTS: Mice were injected with streptozotocin (STZ) to induce a diabetes model. H9c2 cardiomyocytes were cultured in high glucose (50 mM) to establish an in vitro model of diabetes. C57BL/6J mice were preinjected with adeno-associated virus 9 (AAV9) intravenously via the tail vein to specifically overexpress myocardial GDF11. GDF11 attenuated pyroptosis in H9c2 cardiomyocytes after high-glucose treatment. In diabetic mice, GDF11 alleviated cardiomyocyte pyroptosis, reduced myocardial fibrosis, and improved cardiac function. Mechanistically, GDF11 inhibited pyroptosis by preventing inflammasome activation. GDF11 achieved this by specifically binding to apoptosis-associated speck-like protein containing a CARD (ASC) and preventing the assembly and activation of the inflammasome. Additionally, the expression of GDF11 during pyroptosis was regulated by peroxisome proliferator-activated receptor α (PPARα). CONCLUSION: These findings demonstrate that GDF11 can treat diabetic cardiomyopathy by alleviating pyroptosis and reveal the role of the PPARα-GDF11-ASC pathway in DCM, providing ideas for new strategies for cardioprotection.
Subject(s)
Diabetes Mellitus, Experimental , Diabetic Cardiomyopathies , Fibrosis , Growth Differentiation Factors , Inflammasomes , Mice, Inbred C57BL , Myocytes, Cardiac , Pyroptosis , Signal Transduction , Animals , Pyroptosis/drug effects , Diabetic Cardiomyopathies/metabolism , Diabetic Cardiomyopathies/pathology , Diabetic Cardiomyopathies/prevention & control , Diabetic Cardiomyopathies/etiology , Diabetic Cardiomyopathies/physiopathology , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Myocytes, Cardiac/drug effects , Diabetes Mellitus, Experimental/metabolism , Cell Line , Inflammasomes/metabolism , Male , Growth Differentiation Factors/metabolism , Rats , Blood Glucose/metabolism , Mice , Glucose/metabolism , Glucose/toxicity , Bone Morphogenetic Proteins , PPAR alphaABSTRACT
INTRODUCTION: Adipose-derived stem cells (ASCs) are multipotent stem cells capable of differentiating into many cell lineages. They play an important role in wound healing by secreting cytokines. Prior studies have demonstrated the presence of proinflammatory cytokines in burn wounds. However, no studies have been performed evaluating the cytokines released by burn wounds with infections. We hypothesized that there is an alteration in the paracrine factors secreted by ASCs in burn wounds with concomitant infections. METHODS: Adipose tissue was collected from patients with burn injuries at their index operation. ASCs were extracted and grown under standard tissue culture techniques. The supernatant was extracted. Cytokine analyses were performed with multiplex assays. Infection was determined using a burn sepsis protocol. The cytokine profiles of the two groups were compared using a Mann-Whitney U test. RESULTS: Sixteen patients were enrolled in the study, 50% with bacterial infection (n = 8). There was no significant difference in the baseline demographics of the two groups (P > 0.05). There were significantly lower concentrations of interleukin 13 and interferon gamma (P < 0.05) in burn patients with concomitant infections. CONCLUSIONS: ASCs are critical to burn wound healing. This study demonstrated diminished production of interleukin 13, an immunoregulatory cytokine involved in the antiinflammatory pathway by downregulating macrophage activity. This study also demonstrated significantly lower levels of interferon gamma in patient with burns and concomitant infection. This cytokine is crucial for antimicrobial defenses.
ABSTRACT
OBJECTIVE: To present six cases exhibiting transient anterior subcapsular vacuolar lens opacities following early postoperative Tanito microhook trabeculotomy (TMH) performed by the same surgeon. METHODS: Six patients who underwent lens-sparing TMH at Meizankai Shimizu Eye Clinic from November 2021 to May 2023, and developed anterior subcapsular vacuolar lens opacities postoperatively were reviewed. Detailed records of surgeries, follow-up findings were collected and reported. RESULTS: In all six cases, anterior vacuolar subcapsular lens opacities were observed on the day after surgery, gradually decreasing without affecting visual acuity or contrast sensitivity. In all cases, without any specific interventions, the opacities disappeared by 21 months postoperatively. CONCLUSION: Anterior subcapsular cataracts, characterized by a vacuolar appearance and transient existence, should be recognized as an early complication of ab interno glaucoma surgery, possibly linked to use of distributed ophthalmic viscosurgical devices and excessive anterior chamber irrigation leading to traumatic cataracts on the lens surface.
Subject(s)
Cataract , Trabeculectomy , Visual Acuity , Adult , Aged , Female , Humans , Male , Middle Aged , Glaucoma/surgery , Intraocular Pressure/physiology , Lens Capsule, Crystalline/surgery , Lens Capsule, Crystalline/pathology , Postoperative Complications , Retrospective Studies , Trabeculectomy/adverse effects , Vacuoles/pathologyABSTRACT
New adjuvant strategies are needed to improve protein-based subunit vaccine immunogenicity. We examined the potential to use nanostructure of 6-O-ascorbyl palmitate to formulate ovalbumin (OVA) protein and an oligodeoxynucleotide (CpG-ODN) (OCC). In mice immunized with a single dose, OCC elicited an OVA-specific immune response superior to OVA/CpG-ODN solution (OC). Rheological studies demonstrated OCC's self-assembling viscoelastic properties. Biodistribution studies indicated that OCC prolonged OVA and CpG-ODN retention at injection site and lymph nodes, reducing systemic spread. Flow-cytometry assays demonstrated that OCC promoted OVA and CpG-ODN co-uptake by Ly6ChiCD11bhiCD11c+ monocytes. OCC and OC induced early IFN-γ in lymph nodes, but OCC led to higher concentration. Conversely, mice immunized with OC showed higher serum IFN-γ concentration compared to those immunized with OCC. In mice immunized with OCC, NK1.1+ cells were the IFN-γ major producers, and IFN-γ was essential for OVA-specific IgG2c switching. These findings illustrate how this nanostructure improves vaccine's response.
Subject(s)
Nanostructures , Oligodeoxyribonucleotides , Ovalbumin , Vaccines, Subunit , Animals , Nanostructures/chemistry , Vaccines, Subunit/immunology , Vaccines, Subunit/chemistry , Vaccines, Subunit/pharmacokinetics , Mice , Oligodeoxyribonucleotides/chemistry , Oligodeoxyribonucleotides/pharmacokinetics , Ovalbumin/immunology , Ovalbumin/chemistry , Female , Mice, Inbred C57BL , Adjuvants, Immunologic/chemistry , Adjuvants, Immunologic/pharmacokinetics , Interferon-gamma/metabolism , Tissue Distribution , Ascorbic Acid/analogs & derivativesABSTRACT
Dementia is a group of symptoms including memory loss, language difficulties, and other types of cognitive and functional impairments that affects 57 million people worldwide, with the incidence expected to double by 2040. Therefore, there is an unmet need to develop reliable biomarkers to diagnose early brain impairments so that emerging interventions can be applied before brain degeneration. Here, we performed biomarker analyses for apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and amyloid-ß 42/40 (Aß42/40) ratio in the plasma of older adults. Participants had blood drawn at baseline and underwent two annual clinical and cognitive evaluations. The groups tested either cognitively normal on both evaluations (NN), cognitively normal year 1 but cognitively impaired year 2 (NI), or cognitively impaired on both evaluations (II). ASC was elevated in the plasma of the NI group compared to the NN and II groups. Additionally, Aß42 was increased in the plasma in the NI and II groups compared to the NN group. Importantly, the area under the curve (AUC) for ASC in participants older than 70 years old in NN vs. NI groups was 0.81, indicating that ASC is a promising plasma biomarker for early detection of cognitive decline.
Subject(s)
Amyloid beta-Peptides , Biomarkers , CARD Signaling Adaptor Proteins , Cognitive Dysfunction , Humans , Biomarkers/blood , Male , Female , Aged , CARD Signaling Adaptor Proteins/blood , Amyloid beta-Peptides/blood , Cognitive Dysfunction/blood , Cognitive Dysfunction/diagnosis , Aged, 80 and over , Glial Fibrillary Acidic Protein/blood , Neurofilament Proteins/blood , Inflammasomes/metabolism , Inflammasomes/blood , Peptide Fragments/bloodABSTRACT
Chronic venous disease (CVD) comprises a spectrum of morphofunctional disorders affecting the venous system, affecting approximately 1 in 3 women during gestation. Emerging evidence highlights diverse maternofetal implications stemming from CVD, particularly impacting the placenta. While systemic inflammation has been associated with pregnancy-related CVD, preliminary findings suggest a potential link between this condition and exacerbated inflammation in the placental tissue. Inflammasomes are major orchestrators of immune responses and inflammation in different organs and systems. Notwithstanding the relevance of inflammasomes, specifically the NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3)- which has been demonstrated in the placentas of women with different obstetric complications, the precise involvement of this component in the placentas of women with CVD remains to be explored. This study employs immunohistochemistry and real-time PCR (RT-qPCR) to examine the gene and protein expression of key components in both canonical and non-canonical pathways of the NLRP3 inflammasome (NLRP3, ASC-apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain-caspase 1, caspase 5, caspase 8, and interleukin 1ß) within the placental tissue of women affected by CVD. Our findings reveal a substantial upregulation of these components in CVD-affected placentas, indicating a potential pathophysiological role of the NLRP3 inflammasome in the development of this condition. Subsequent investigations should focus on assessing translational interventions addressing this dysregulation in affected patient populations.