A novel TNNI2 mutation causes Freeman–Sheldon syndrome in a Chinese family with an affected adult with only facial contractures

Distal arthrogryposes (DAs), a clinically and genetically heterogeneous group of disorders characterized by congenital contractures with predominant involvement of the hands and feet, can be classified into at least 12 different forms. These autosomal dominant disorders are of variable expressivity and reduced penetrance. Mutations in sarcomeric protein genes, including troponin I2 (TNNI2), troponin T3 (TNNT3), tropomyosin 2 (TPM2), embryonic myosin heavy chain 3 (MYH3), and myosin binding protein C1 (MYBPC1), have been identified in distal arthrogryposis type 1 (DA1, MIM 108120), type 2B (DA2B, MIM 601680) and type 2A (DA2A)/Freeman–Sheldon syndrome (FSS, MIM 193700). However, mutations causing FSS have only been reported in MYH3. Herein we describe a Chinese DA family whose members meet classical strict criteria for FSS, as well as one member of the family who has isolated facial features consistent with FSS. No disease-causing mutation was found in MYH3. Segregation of microsatellite markers flanking the TNNI2 and TNNT3 genes at 11p15.5 was compatible with linkage. Subsequent sequencing of TNNI2 revealed a novel mutation, c.A493T (p.I165F), located in the C-terminal region, which is critical for proper protein function. This mutation was found to cosegregate with the FSS phenotype in this family, and assessment using SIFT and PolyPhen-2 predicted a damaging effect. To the best of our knowledge, we report the first TNNI2 mutation in classical FSS and describe an atypical adult FSS case with only facial contractures resulting from somatic mosaicism. We infer that DA1, DA2B and FSS represent a phenotypic continuum of the same disorder and provide further genetic evidence for this hypothesis.     

苍附导痰丸治疗痰湿型多囊卵巢综合征的疗效及对外周血PI3K/AKT信号通路的影响

摘要 目的：探讨苍附导痰丸治疗痰湿型多囊卵巢综合征（PCOS）的疗效及对外周血磷脂酰肌醇-3-激酶（PI3K）/蛋白激酶B（AKT）信号通路的影响。方法：纳入河北省沧州中西医结合医院2022年1月~2022年10月收治的86例痰湿型PCOS患者。根据随机数字表法,分为对照组（n=43,达英-35治疗）和实验组（n=43,达英-35联合苍附导痰丸治疗）。观察两组中医证候积分、性激素指标、糖脂代谢指标、PI3K/AKT信号通路相关指标变化情况和不良反应发生率。结果：与对照组治疗后相比,实验组中医证候积分、甘油三酯（TG）、促卵泡生成素（FSH）、低密度脂蛋白胆固醇（LDL-C）、睾酮（T）、促黄体生成素（LH）、空腹血糖（FBG）、总胆固醇（TC）、空腹胰岛素（FINS）水平和PI3K 信使核糖核酸（mRNA）、AKT mRNA更低,高密度脂蛋白胆固醇（HDL-C）更高（P<0.05）。两组不良反应发生率对比未见差异（P>0.05）。结论：苍附导痰丸治疗痰湿型PCOS患者,可有效调节性激素、糖脂代谢指标,改善临床症状,可能与调节外周血PI3K/AKT信号通路有关。     

Potential for daily supplementation of n-3 fatty acids to reverse symptoms of dry eye in mice

The purpose of this study was to determine the change in tear volume, as a predominant symptom of dry eye syndrome, in dietary n-3 fatty acid deficient mice compared with n-3 fatty acid adequate mice. The tear volume in n-3 fatty acid deficient mice was significantly lower than that in n-3 fatty acid adequate mice. In addition, the concentration of n-3 fatty acid in the lacrimal and meibomian glands, which affects the production of tears, was markedly decreased compared with n-3 fatty acid adequate mice. However, the tear volume recovered almost completely after one week of continuous administration of fish oil containing EPA and DHA in n-3 fatty acid deficient mice. Also, the concentration of DHA in the meibomian gland of n-3 fatty acid deficient group recovered to approximately 80% more than that of n-3 fatty acid adequate group. These results suggested that dietary n-3 fatty acids deficiency showed reversible dry eye syndrome, and that n-3 fatty acids have an important role in the production of tears.     

Disease-associated Substitutions in the Filamin B Actin Binding Domain Confer Enhanced Actin Binding Affinity in the Absence of Major Structural Disturbance: Insights from the Crystal Structures of Filamin B Actin Binding Domains

Missense mutations in filamin B (FLNB) are associated with the autosomal dominant atelosteogenesis (AO) and the Larsen group of skeletal malformation disorders. These mutations cluster in particular FLNB protein domains and act in a presumptive gain-of-function mechanism. In contrast the loss-of-function disorder, spondylocarpotarsal synostosis syndrome, is characterised by the complete absence of FLNB. One cluster of AO missense mutations is found within the second of two calponin homology (CH) domains that create a functional actin-binding domain (ABD). This N-terminal ABD is required for filamin F-actin crosslinking activity, a crucial aspect of filamin's role of integrating cell-signalling events with cellular scaffolding and mechanoprotection. This study characterises the wild type FLNB ABD and investigates the effects of two disease-associated mutations on the structure and function of the FLNB ABD that could explain a gain-of-function mechanism for the AO diseases. We have determined high-resolution X-ray crystal structures of the human filamin B wild type ABD, plus W148R and M202V mutants. All three structures display the classic compact monomeric conformation for the ABD with the CH1 and CH2 domains in close contact. The conservation of tertiary structure in the presence of these mutations shows that the compact ABD conformation is stable to the sequence substitutions. In solution the mutant ABDs display reduced melting temperatures (by 6-7 °C) as determined by differential scanning fluorimetry. Characterisation of the wild type and mutant ABD F-actin binding activities via co-sedimentation assays shows that the mutant FLNB ABDs have increased F-actin binding affinities, with dissociation constants of 2.0 μM (W148R) and 0.56 μM (M202V), compared to the wild type ABD K_d of 7.0 μM. The increased F-actin binding affinity of the mutants presents a biochemical mechanism that differentiates the autosomal dominant gain-of-function FLNB disorders from those that arise through the complete loss of FLNB protein.     

Characterization of conserved motifs in HIV-1 Vif required for APOBEC3G and APOBEC3F interaction

Apolipoprotein B mRNA-editing catalytic polypeptide-like 3G (APOBEC3G, or A3G) and related cytidine deaminases such as apolipoprotein B mRNA-editing catalytic polypeptide-like 3F (APOBEC3F, or A3F) are potent inhibitors of retroviruses. Formation of infectious human immunodeficiency virus (HIV)-1 requires suppression of multiple cytidine deaminases by Vif. HIV-1 Vif suppresses various APOBEC3 proteins through a common mechanism by recruiting Cullin5, ElonginB, and ElonginC E3 ubiquitin ligase to induce target protein polyubiquitination and proteasome-mediated degradation. Domains in Vif that mediate APOBEC3 recognition have not been fully characterized. In the present study, we identified a VxIPLx_4-5LxΦx₂YWxL motif in HIV-1 Vif, which is required for efficient interaction between Vif and A3G, Vif-mediated A3G degradation and virion exclusion, and functional suppression of the A3G antiviral activity. Amino acids 52 to 72 of HIV-1 Vif (including the VxIPLx_4-5LxΦx₂YWxL motif) alone could mediate interaction with A3G, and this interaction was abolished by mutations of two hydrophobic amino acids in this region. We have also observed that a Vif mutant was ineffective against A3G, yet it retained the ability to interact with Cullin5-E3 ubiquitin complex and A3G, suggesting that interaction with A3G is necessary but not sufficient to inhibit its antiviral function. Unlike the previously identified motif of HIV-1 Vif amino acids 40 to 44, which is only important for A3G suppression, the VxIPLx_4-5LxΦx₂YWxL motif is also required for efficient A3F interaction and suppression. On the other hand, another motif, TGERxW, of HIV-1 Vif amino acids 74 to 79 was found to be mainly important for A3F interaction and inhibition. Both the VxIPLx_4-5LxΦx₂YWxL and TGERxW motifs are highly conserved among HIV-1, HIV-2, and various simian immunodeficiency virus Vif proteins. Our data suggest that primate lentiviral Vif molecules recognize their autologous APOBEC3 proteins through conserved structural features that represent attractive targets for the development of novel inhibitors.     

Progress of endocytic CHRN to autophagic degradation is regulated by RAB5-GTPase and T145 phosphorylation of SH3GLB1 at mouse neuromuscular junctions in vivo

Endocytosed nicotinic acetylcholine receptors (CHRN) are degraded via macroautophagy/autophagy during atrophic conditions and are accompanied by the autophagic regulator protein SH3GLB1. The present study addressed the functional role of SH3GLB1 on CHRN trafficking and its implementation. We found an augmented ratio of total SH3GLB1 to threonine-145 phosphorylated SH3GLB1 (SH3GLB1:p-SH3GLB1) under conditions of increased CHRN vesicle numbers. Overexpression of T145 phosphomimetic (T145E) and phosphodeficient (T145A) mutants of SH3GLB1, was found to either slow down or augment the processing of endocytic CHRN vesicles, respectively. Co-expression of the early endosomal orchestrator RAB5 largely rescued the slow processing of endocytic CHRN vesicles induced by T145E. SH3GLB1 phosphomutants did not modulate the expression or colocalization of RAB5 with CHRN vesicles, but instead altered the expression of RAB5 activity regulators. In summary, these findings suggest that SH3GLB1 controls CHRN endocytic trafficking in a phosphorylation- and RAB5-dependent manner at steps upstream of autophagosome formation.     

But1 and But2 proteins bind to Uba3, a catalytic subunit of E1 for neddylation, in fission yeast

NEDD8/Rub1 is the most homologous protein to ubiquitin among the ubiquitin-like proteins, and it is covalently linked to target proteins via the C-terminal glycine residue in a manner analogous to ubiquitylation. However, the mechanism(s) involved in the regulation of the NEDD8 ligation pathway remains elusive. Using the two-hybrid system, we isolated novel genes from the Schizosaccharomyces pombe cDNA library whose products bind to Uba3, which is a catalytic protein for E1-like activity of the NEDD8 pathway. We designated these genes but1(+) and but2(+) (for proteins that bind to Uba three). But1 is a nuclear protein and its overexpression caused cell elongation, which is a common phenotype of the NEDD8 pathway defective mutant in S. pombe. Furthermore, overexpression of but1(+) in ned8-temperature sensitive mutant had a deleterious effect even under permissive temperatures. Our results suggest that But1 may have an inhibitory role in the NEDD8 pathway.     

A novel mutation screening system for Ehlers-Danlos Syndrome, vascular type by high-resolution melting curve analysis in combination with small amplicon genotyping using genomic DNA

Ehlers-Danlos syndrome, vascular type (vEDS) (MIM #130050) is an autosomal dominant disorder caused by type III procollagen gene (COL3A1) mutations. Most COL3A1 mutations are detected by using total RNA from patient-derived fibroblasts, which requires an invasive skin biopsy. High-resolution melting curve analysis (hrMCA) has recently been developed as a post-PCR mutation scanning method which enables simple, rapid, cost-effective, and highly sensitive mutation screening of large genes. We established a hrMCA method to screen for COL3A1 mutations using genomic DNA. PCR primers pairs for COL3A1 (52 amplicons) were designed to cover all coding regions of the 52 exons, including the splicing sites. We used 15 DNA samples (8 validation samples and 7 samples of clinically suspected vEDS patients) in this study. The eight known COL3A1 mutations in validation samples were all successfully detected by the hrMCA. In addition, we identified five novel COL3A1 mutations, including one deletion (c.2187delA) and one nonsense mutation (c.2992C>T) that could not be determined by the conventional total RNA method. Furthermore, we established a small amplicon genotyping (SAG) method for detecting three high frequency coding-region SNPs (rs1800255:G>A, rs1801184:T>C, and rs2271683:A>G) in COL3A1 to differentiate mutations before sequencing. The use of hrMCA in combination with SAG from genomic DNA enables rapid detection of COL3A1 mutations with high efficiency and specificity. A better understanding of the genotype–phenotype correlation in COL3A1 using this method will lead to improve in diagnosis and treatment.     

Splicing Defects in the COL3A1 Gene: Marked Preference for 5′ (Donor) Splice-Site Mutations in Patients with Exon-Skipping Mutations and Ehlers-Danlos Syndrome Type IV

Ehlers-Danlos syndrome (EDS) type IV results from mutations in the COL3A1 gene, which encodes the constituent chains of type III procollagen. We have identified, in 33 unrelated individuals or families with EDS type IV, mutations that affect splicing, of which 30 are point mutations at splice junctions and 3 are small deletions that remove splice-junction sequences and partial exon sequences. Except for one point mutation at a donor site, which leads to partial intron inclusion, and a single base-pair substitution at an acceptor site, which gives rise to inclusion of the complete upstream intron into the mature mRNA, all mutations result in deletion of a single exon as the only splice alteration. Of the exon-skipping mutations that are due to single base substitutions, which we have identified in 28 separate individuals, only two affect the splice-acceptor site. The underrepresentation of splice acceptor-site mutations suggests that the favored consequence of 3' mutations is the use of an alternative acceptor site that creates a null allele with a premature-termination codon. The phenotypes of those mutations may differ, with respect to either their severity or their symptomatic range, from the usual presentation of EDS type IV and thus have been excluded from analysis.     

Evidence for the prevention of enthesitis in HLA‐B27/hβ2m transgenic rats treated with a monoclonal antibody against TNF‐α

Transgenic rats with high expression of HLA‐B27 and human β₂‐microglobulin (B27TR) develop a multisystem inflammatory disease resembling human inflammatory bowel disease (IBD) and spondyloarthropaties (SpA). Tumour necrosis factor α (TNF‐α) has a crucial role in sustaining chronic inflammation in the gut and joints. The aim of this work was to evaluate whether TNF‐α blockade could prevent or reduce the inflammation of peripheral joints in B27TR. A first group of 9‐week‐old B27TR received an anti‐TNF‐α monoclonal antibody (mAb) or an isotypic IgG2a,k up to the age of 18 weeks. An untreated group was monitored up to the age of 18 weeks and then randomly assigned to a 9‐week treatment with anti‐TNF‐α mAb or IgG2a,k. Each rat was monitored for clinical IBD and peripheral joint manifestations. After sacrifice the colon and hind paws were examined for macroscopical and microscopical pathological changes. Early TNF‐α blockade prevented, and late treatment improved IBD signs in B27TR. Erythema, oedema, inflammatory infiltrate close to the tendons and enthesis, proliferating chondrocyte‐like cells, signs of new endochondral bone ossification and bone erosion were observed in peripheral joints of four out of six IgG2a,k‐treated B27TR, both at 18 and 27 weeks. Immunopositivity for phosphorylated Smad1/5/8 indicated that the process of joint remodelling was activated in B27TR. Some entheses showed chondroid nodules. Anti‐TNF‐α treatment reduced inflammation and preserved the enthesis organization in most animals. Occasional and transient erythema and oedema were still present in three of six of the late anti‐TNF‐α‐treated animals. Smad1/5/8 signalling was not inhibited by late anti‐TNF‐α treatment. In B27TR, articular involvement follows IBD onset and develops at entheses. Early TNF‐α blockade prevents the onset of IBD and consequently the development of enthesitis in peripheral joints in the B27TR model of human SpA.     

Redesigning the type II' β‐turn in green fluorescent protein to type I': Implications for folding kinetics and stability

Both Type I' and Type II' β‐turns have the same sense of the β‐turn twist that is compatible with the β‐sheet twist. They occur predominantly in two residue β‐hairpins, but the occurrence of Type I' β‐turns is two times higher than Type II' β‐turns. This suggests that Type I' β‐turns may be more stable than Type II' β‐turns, and Type I' β‐turn sequence and structure can be more favorable for protein folding than Type II' β‐turns. Here, we redesigned the native Type II' β‐turn in GFP to Type I' β‐turn, and investigated its effect on protein folding and stability. The Type I' β‐turns were designed based on the statistical analysis of residues in natural Type I' β‐turns. The substitution of the native “GD” sequence of i+1 and i+2 residues with Type I' preferred “(N/D)G” sequence motif increased the folding rate by 50% and slightly improved the thermodynamic stability. Despite the enhancement of in vitro refolding kinetics and stability of the redesigned mutants, they showed poor soluble expression level compared to wild type. To overcome this problem, i and i + 3 residues of the designed Type I' β‐turn were further engineered. The mutation of Thr to Lys at i + 3 could restore the in vivo soluble expression of the Type I' mutant. This study indicates that Type II' β‐turns in natural β‐hairpins can be further optimized by converting the sequence to Type I'. Proteins 2014; 82:2812–2822. © 2014 Wiley Periodicals, Inc.     

Structure‐guided screening of chemical database to identify NS3‐NS2B inhibitors for effective therapeutic application in dengue infection

Dengue infection is the most common arthropod‐borne disease caused by dengue viruses, predominantly affecting millions of human beings annually. To find out promising chemical entities for therapeutic application in Dengue, in the current research, a multi‐step virtual screening effort was conceived to screen out the entire “screening library” of the Asinex database. Initially, through “Lipinski rule of five” filtration criterion almost 0.6 million compounds were collected and docked with NS3‐NS2B protein. Thereby, the chemical space was reduced to about 3500 compounds through the analysis of binding affinity obtained from molecular docking study in AutoDock Vina. Further, the “Virtual Screening Workflow” (VSW) utility of Schrödinger suite was used, which follows a stepwise multiple docking programs such as ‐ high‐throughput virtual screening (HTVS), standard precision (SP), and extra precision (XP) docking, and in postprocessing analysis the MM‐GBSA based free binding energy calculation. Finally, five potent molecules were proposed as potential inhibitors for the dengue NS3‐NS2B protein based on the investigation of molecular interactions map and protein‐ligand fingerprint analyses. Different pharmacokinetics and drug‐likeness parameters were also checked, which favour the potentiality of selected molecules for being drug‐like candidates. The molecular dynamics (MD) simulation analyses of protein‐ligand complexes were explained that NS3‐NS2B bound with proposed molecules quite stable in dynamic states as observed from the root means square deviation (RMSD) and root means square fluctuation (RMSF) parameters. The binding free energy was calculated using MM‐GBSA method from the MD simulation trajectories revealed that all proposed molecules possess such a strong binding affinity towards the dengue NS3‐NS2B protein. Therefore, proposed molecules may be potential chemical components for effective inhibition of dengue NS3‐NS2B protein subjected to experimental validation.     

Inhibition of NF‐κB is required for oleanolic acid to downregulate PD‐L1 by promoting DNA demethylation in gastric cancer cells

Gastric cancer is one of the most common causes of cancer‐related death worldwide. Immunotherapy via programmed cell death protein 1 (PD‐1)/programmed cell death‐ligand 1 (PD‐L1) blockade has shown benefits for gastric cancer. Epigenetic DNA methylation critically regulates cancer immune checkpoints. We investigated how the natural compound oleanolic acid (OA) affected PD‐L1 expression in gastric cancer cells. Interleukin‐1β (IL‐1β) at 20 ng/mL was used to stimulate human gastric cancer MKN‐45 cells. IL‐1β significantly increased PD‐L1 expression, which was abolished by OA. Next, OA‐treated MKN‐45 cells were co‐cultured with activated and PD‐1‐overexpressing Jurkat T cells. OA restored IL‐2 levels in the co‐culture system and increased T cell killing toward MKN‐45 cells. Overexpression of PD‐L1 eliminated OA‐enhanced T cell killing capacity; however, PD‐1 blocking antibody abrogated the cytotoxicity of T cells. Moreover, OA abolished IL‐1β‐increased DNA demethylase activity in MKN‐45 cells. DNA methyltransferase inhibitor 5‐azacytidine rescued OA‐reduced PD‐L1 expression; whereas DNA demethylation inhibitor gemcitabine inhibited PD‐L1 expression, and, in combination with OA, provided more potent inhibitory effects. Furthermore, OA selectively reduced the expression of DNA demethylase TET3 in IL‐1β‐treated MKN‐45 cells, and overexpression of TET3 restored OA‐reduced PD‐L1 expression. Finally, OA disrupted nuclear factor κB (NF‐κB) signaling IL‐1β‐treated MKN‐45 cells, and overexpression of NF‐κB restored OA downregulation of TET3 and PD‐L1. The cytotoxicity of T cells toward MKN‐45 cells was also weakened by NF‐κB overexpression. Altogether, OA blocked the IL‐1β/NF‐κB/TET3 axis in gastric cancer cells, leading to DNA hypomethylation and downregulation of PD‐L1. Our discoveries suggested OA as an epigenetic modulator for immunotherapy or an adjuvant therapy against gastric cancer.     

Receptor for advanced glycation end products aggravates cognitive deficits in type 2 diabetes through binding of C‐terminal AAs 2‐5 to mitogen‐activated protein kinase kinase 3 (MKK3) and facilitation of MEKK3‐MKK3‐p38 module assembly

In this study, we explored the precise mechanisms underlying the receptor for advanced glycation end products (RAGE)‐mediated neuronal loss and behavioral dysfunction induced by hyperglycemia. We used immunoprecipitation (IP) and GST pull‐down assays to assess the interaction between RAGE and mitogen‐activated protein kinase kinase 3 (MKK3). Then, we investigated the effect of specific mutation of RAGE on plasticity at hippocampal synapses and behavioral deficits in db/db mice through electrophysiological recordings, morphological assays, and behavioral tests. We discovered that RAGE binds MKK3 and that this binding is required for assembly of the MEKK3‐MKK3‐p38 signaling module. Mechanistically, we found that activation of p38 mitogen‐activated protein kinase (MAPK)/NF‐κB signaling depends on mediation of the RAGE‐MKK3 interaction by C‐terminal RAGE (ctRAGE) amino acids (AAs) 2‐5. We found that ctRAGE R2A‐K3A‐R4A‐Q5A mutation suppressed neuronal damage, improved synaptic plasticity, and alleviated behavioral deficits in diabetic mice by disrupting the RAGE‐MKK3 conjugation. High glucose induces direct binding of RAGE and MKK3 via ctRAGE AAs 2‐5, which leads to assembly of the MEKK3‐MKK3‐p38 signaling module and subsequent activation of the p38MAPK/NF‐κB pathway, and ultimately results in diabetic encephalopathy (DE).     

Knockout of Nr2e3 prevents rod photoreceptor differentiation and leads to selective L-/M-cone photoreceptor degeneration in zebrafish

Mutations in the photoreceptor cell-specific nuclear receptor gene Nr2e3 increased the number of S-cone photoreceptors in human and murine retinas and led to retinal degeneration that involved photoreceptor and non-photoreceptor cells. The mechanisms underlying these complex phenotypes remain unclear. In the hope of understanding the precise role of Nr2e3 in photoreceptor cell fate determination and differentiation, we generated a line of Nr2e3 knockout zebrafish using CRISPR technology. In these Nr2e3-null animals, rod precursors undergo terminal mitoses but fail to differentiate as rods. Rod-specific genes are not expressed and the outer segment (OS) fails to form. Formation and differentiation of cone photoreceptors is normal. Specifically, there is no increase in the number of UV-cone or S-cone photoreceptors. Laminated retinal structure is maintained. After normal development, L-/M-cones selectively degenerate, with progressive shortening of OS that starts at age 1 month. The amount of cone phototransduction proteins is concomitantly reduced, whereas UV- and S-cones have normal OS lengths even at age 10 months. In vitro studies show Nr2e3 synergizes with Crx and Nrl to enhance rhodopsin gene expression. Nr2e3 does not affect cone opsin expression. Our results extend the knowledge of Nr2e3's roles and have specific implications for the interpretation of the phenotypes observed in human and murine retinas. Furthermore, our model may offer new opportunities in finding treatments for enhanced S-cone syndrome (ESCS) and other retinal degenerative diseases.     

Caspase-1 Is an Apical Caspase Leading to Caspase-3 Cleavage in the AIM2 Inflammasome Response,Independent of Caspase-8

Canonical inflammasomes are multiprotein complexes that can activate both caspase-1 and caspase-8. Caspase-1 drives rapid lysis of cells by pyroptosis and maturation of interleukin (IL)-1β and IL-18. In caspase-1-deficient cells, inflammasome formation still leads to caspase-3 activation and slower apoptotic death, dependent on caspase-8 as an apical caspase. A role for caspase-8 directly upstream of caspase-1 has also been suggested, but here we show that caspase-8-deficient macrophages have no defect in AIM2 inflammasome-mediated caspase-1 activation, pyroptosis, and IL-1β cleavage. In investigating the inflammasome-induced apoptotic pathway, we previously demonstrated that activated caspase-8 is essential for caspase-3 cleavage and apoptosis in caspase-1-deficient cells. However, here we found that AIM2 inflammasome-initiated caspase-3 cleavage was maintained in Ripk3^?/? Casp8^?/? macrophages. Gene knockdown showed that caspase-1 was required for the caspase-3 cleavage. Thus inflammasomes activate a network of caspases that can promote both pyroptotic and apoptotic cell death. In cells where rapid pyroptosis is blocked, delayed inflammasome-dependent cell death could still occur due to both caspase-1- and caspase-8-dependent apoptosis. Initiation of redundant cell death pathways is likely to be a strategy for coping with pathogen interference in death processes.