Necroptosis is a type of programmed cell death with great significance in many pathological processes. Tumour necrosis factor-α(TNF), a proinflammatory cytokine, is a prototypic trigger of ...necroptosis. It is known that mitochondrial reactive oxygen species (ROS) promote necroptosis, and that kinase activity of receptor interacting protein 1 (RIP1) is required for TNF-induced necroptosis. However, how ROS function and what RIP1 phosphorylates to promote necroptosis are largely unknown. Here we show that three crucial cysteines in RIP1 are required for sensing ROS, and ROS subsequently activates RIP1 autophosphorylation on serine residue 161 (S161). The major function of RIP1 kinase activity in TNF-induced necroptosis is to autophosphorylate S161. This specific phosphorylation then enables RIP1 to recruit RIP3 and form a functional necrosome, a central controller of necroptosis. Since ROS induction is known to require necrosomal RIP3, ROS therefore function in a positive feedback circuit that ensures effective induction of necroptosis.
There remains a significant gap in our quantitative understanding of crosstalk between apoptosis and necroptosis pathways. By employing the SWATH-MS technique, we quantified absolute amounts of up to ...thousands of proteins in dynamic assembling/deassembling of TNF signaling complexes. Combining SWATH-MS-based network modeling and experimental validation, we found that when RIP1 level is below ∼1000 molecules/cell (mpc), the cell solely undergoes TRADDdependent apoptosis. When RIP1 is above ∼1000 mpc, pro-caspase-8 and RIP3 are recruited to necrosome respectively with linear and nonlinear dependence on RIP1 amount, which well explains the co-occurrence of apoptosis and necroptosis and the paradoxical observations that RIP1 is required for necroptosis but its increase down-regulates necroptosis. Higher amount of RIP1 (>∼46,000 mpc) suppresses apoptosis, leading to necroptosis alone. The relation between RIP1 level and occurrence of necroptosis or total cell death is biphasic. Our study provides a resource for encoding the complexity of TNF signaling and a quantitative picture how distinct dynamic interplay among proteins function as basis sets in signaling complexes, enabling RIP1 to play diverse roles in governing cell fate decisions.
Malaria is caused by infection of the erythrocytes by the parasites Plasmodium. Inside the erythrocytes, the parasites multiply via schizogony, an unconventional cell division mode. The inner ...membrane complex (IMC), an organelle located beneath the parasite plasma membrane, serving as the platform for protein anchorage, is essential for schizogony. So far, the complete repertoire of IMC proteins and their localization determinants remain unclear. Here we used biotin ligase (TurboID)-based proximity labeling to compile the proteome of the schizont IMC of the rodent malaria parasite Plasmodium yoelii. In total, 300 TurboID-interacting proteins were identified. 18 of 21 selected candidates were confirmed to localize in the IMC, indicating good reliability. In light of the existing palmitome of Plasmodium falciparum, 83 proteins of the P. yoelii IMC proteome are potentially palmitoylated. We further identified DHHC2 as the major resident palmitoyl-acyl-transferase of the IMC. Depletion of DHHC2 led to defective schizont segmentation and growth arrest both in vitro and in vivo. DHHC2 was found to palmitoylate two critical IMC proteins CDPK1 and GAP45 for their IMC localization. In summary, this study reports an inventory of new IMC proteins and demonstrates a central role of DHHC2 in governing the IMC localization of proteins during the schizont development.
Morphogenesis of many protozoans depends on a polarized establishment of cortical cytoskeleton containing the subpellicular microtubules (SPMTs), which are apically nucleated and anchored by the ...apical polar ring (APR). In malaria parasite Plasmodium, APR emerges in the host-invading stages, including the ookinete for mosquito infection. So far, the fine structure and molecular components of APR as well as the underlying mechanism of APR-mediated apical positioning of SPMTs are largely unknown. Here, we resolve an unprecedented APR structure composed of a top ring plus approximate 60 radiating spines. We report an APR-localizing and SPMT-binding protein APR2. APR2 disruption impairs ookinete morphogenesis and gliding motility, leading to Plasmodium transmission failure in mosquitoes. The APR2-deficient ookinetes display defective apical anchorage of APR and SPMT due to the impaired integrity of APR. Using protein proximity labeling, we obtain a Plasmodium ookinete APR proteome and validate ten undescribed APR proteins. Among them, APRp2 and APRp4 directly interact with APR2 and also mediate the apical anchorage of SPMTs. This study sheds light on the molecular basis of APR in the organization of Plasmodium ookinete SPMTs.
Necroptosis induction in vitro often requires caspase-8 (Casp8) inhibition by zVAD because pro-Casp8 cleaves RIP1 to disintegrate the necrosome. It has been unclear how the Casp8 blockade of ...necroptosis is eliminated naturally. Here, we show that pro-Casp8 within the necrosome can be inactivated by phosphorylation at Thr265 (pC8T265). pC8T265 occurs in vitro in various necroptotic cells and in the cecum of TNF-treated mice. p90 RSK is the kinase of pro-Casp8. It is activated by a mechanism that does not need ERK but PDK1, which is recruited to the RIP1-RIP3-MLKL-containing necrosome. Phosphorylation of pro-Casp8 at Thr265 can substitute for zVAD to permit necroptosis in vitro. pC8T265 mimic T265E knockin mice are embryonic lethal due to unconstrained necroptosis, and the pharmaceutical inhibition of RSK-mediated pC8T265 diminishes TNF-induced cecum damage and lethality in mice by halting necroptosis. Thus, phosphorylation of pro-Casp8 at Thr265 by RSK is an intrinsic mechanism for passing the Casp8 checkpoint of necroptosis.
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•Phosphorylation of pro-caspase-8 at Thr265 releases the blockade of necroptosis•RSK phosphorylates pro-caspase-8 at Thr265 in the necrosome•PDK1 activates RSK by an ERK-independent mechanism to promote necroptosis•RSK inhibition protects mice from TNF-induced cecum injury and lethality
An intrinsic mechanism—RSK, activated by TNF via PDK1—for overcoming necroptosis blockade is revealed by Yang et al. that phosphorylates pro-caspase-8 at Thr265 within the necrosome to inactivate pro-caspase-8.
To evaluate association between pretreatment serum metrics and best corrected visual acuity ( BCVA) of patients with macular edema secondary to retinal vein occlusion and its subtypes after ...intravitreal ranibizumab or conbercept implant.
This prospective research included 201 patients(201 eyes) who were diagnosed with macular edema secondary to retinal vein occlusion at Heibei Eye Hospital between January 2020 and January 2021, who all received intravitreal anti- vascular endothelial growth factor treatment. Serum metrics were measured before the first treatment, and correlations between BCVA and each of four parameters- platelets, neutrophil- to- lymphocyte ratio(NLR), platelet- to- lymphocyte ratio(PLR) and monocyte- to- lymphocyte ratio(MLR)- were analyzed to identify predictors of effective intravitreal injection treatment outcomes.
The mean platelets was significantly different in the effective and ineffective group for RVO-ME (273.02 ± 41.49 × 109/L,214.54 ± 44.08 × 109/L P < 0.01),BRVO-ME (269.43 ± 49.52 × 109/L,214.72 ± 40.42 × 109/L P < 0.01), and CRVO-ME (262.32 ± 32.41 × 109/L,209.27 ± 42 0.91 × 109/L P < 0.01). The cutoff value of the platelets was 266.500, the area under the curve was 0.857,and the sensitivity and specificity were 59.8% and 93.6%, respectively. The mean PLR was significantly different in the effective and ineffective group for RVO-ME (154.66 ± 49.60, 122.77± 44.63 P < 0.01),BRVO-ME (152.24 ± 54.99, 124.72 ± 41.46 P = 0.003), and CRVO-ME (152.06±44.23, 118.67 ± 41.80 P = 0.001). The cutoff value of the platelets was 126.734, the area under the curve was 0.699, and the sensitivity and specificity were 70.7% and 63.3%, respectively. There were no statistical differencies between the effective and ineffective group(RVO- ME and its subtypes) in NLR and MLR.
Higher pretreatment platelets and PLR were associated with BCVA in patients with RVO- ME and its subtypes who were treated with anti- VEGF drugs. The platelets and PLR may be used as predictive and prognostic tools for effective intravitreal injection treatment outcomes.
Objectives
This study aimed to use the results of routine blood tests and relevant parameters to construct models for the prediction of active tuberculosis (ATB) and drug-resistant tuberculosis ...(DRTB) and to assess the diagnostic values of these models.
Methods
We performed logistic regression analysis to generate models of plateletcrit-albumin scoring (PAS) and platelet distribution width-treatment-sputum scoring (PTS). Area under the curve (AUC) analysis was used to analyze the diagnostic values of these curves. Finally, we performed model validation and application assessment.
Results
In the training cohort, for the PAS model, the AUC for diagnosing ATB was 0.902, sensitivity was 82.75%, specificity was 82.20%, accuracy rate was 81.00%, and optimal threshold value was 0.199. For the PTS model, the AUC for diagnosing DRTB was 0.700, sensitivity was 63.64%, specificity was 73.53%, accuracy rate was 89.00%, and optimal threshold value was −2.202. These two models showed significant differences in the AUC analysis, compared with single-factor models. Results in the validation cohort were similar.
Conclusions
The PAS model had high sensitivity and specificity for the diagnosis of ATB, and the PTS model had strong predictive potential for the diagnosis of DRTB.
The number of systematic reviews or meta-analyses (SRs/MAs) on the effectiveness of acupuncture for angina pectoris (AP) is increasing. Due to the inconsistent conclusions and unknown quality of ...these SRs/MAs, this overview aimed to systematically evaluate and synthesize the existing SRs/MAs, attempting to provide more reliable evidence for the effectiveness and safety of acupuncture in the treatment of AP.
SRs/MAs were searched via eight databases from inception to March 14, 2022. The risk of bias was evaluated using the Risk of Bias in Systematic reviews (ROBIS) tool. The quality of the methodology, reporting, and evidence were assessed by the Assess Systematic Reviews 2 (AMSTAR-2), the Preferred Reporting Item for Systematic Review and Meta-analysis for Acupuncture (PRISMA-A), and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system, respectively.
Sixteen SRs/MAs were included and fifteen SRs/MAs were considered being of critically low quality according to AMSTAR-2. Only three SRs/MAs were rated at low risk of bias. No study reported all the items listed in the PRISMA-A checklist. No high-quality evidence with GRADE assessment was found. With the low-quality evidence, acupuncture combined with other interventions was superior to monotherapy (medications or Chinese medicine) in the angina symptom and electrocardiogram recovery. No adverse effects owing to acupuncture were reported.
Owing to the lack of high-quality evidence provided by the current SRs/MAs, the effectiveness of acupuncture for AP still warrants further proof. Further researches with more critical design and methodology are needed for providing more convincing evidence.
This review was registered at PROSPERO (www.crd.york.ac.uk/prospero/): CRD42021219367.
During eye development, the selector factors of the Eyeless/Pax6 or Retinal Determination (RD) network control specification of organ-type whereas the bHLH-type proneural factor Atonal drives ...neurogenesis. Although significant progress has been made in dissecting the acquisition of `eye identity' at the transcriptional level, the molecular mechanisms underlying the progression from neuronal progenitor to differentiating neuron remain unclear. A recently proposed model for the integration of organ specification and neurogenesis hypothesizes that atonal expression in the eye is RD-network-independent and that Eyeless works in parallel or downstream of atonal to modify the neurogenetic program. We show here that distinct cis-regulatory elements control atonal expression specifically in the eye and that the RD factors Eyeless and Sine oculis function as direct regulators. We find that these transcription factors interact in vitro and provide indirect evidence that this interaction may be required in vivo. The subordination of neurogenesis to the RD pathway in the eye provides a direct mechanism for the coordination of neurogenesis and tissue specification during sensory organ formation.
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