Effector-dependent activation and oligomerization of plant NRC class helper NLRs by sensor NLR immune receptors Rpi-amr3 and Rpi-amr1.

Plant pathogens compromise crop yields. Plants have evolved robust innate immunity that depends in part on intracellular Nucleotide-binding, Leucine rich-Repeat (NLR) immune receptors that activate defense responses upon detection of pathogen-derived effectors. Most "sensor" NLRs that detect effectors require the activity of "helper" NLRs, but how helper NLRs support sensor NLR function is poorly understood. Many Solanaceae NLRs require NRC (NLR-Required for Cell death) class of helper NLRs. We show here that Rpi-amr3, a sensor NLR from Solanum americanum, detects AVRamr3 from the potato late blight pathogen, Phytophthora infestans, and activates oligomerization of helper NLRs NRC2 and NRC4 into high-molecular-weight resistosomes. In contrast, recognition of P. infestans effector AVRamr1 by another sensor NLR Rpi-amr1 induces formation of only the NRC2 resistosome. The activated NRC2 oligomer becomes enriched in membrane fractions. ATP-binding motifs of both Rpi-amr3 and NRC2 are required for NRC2 resistosome formation, but not for the interaction of Rpi-amr3 with its cognate effector. NRC2 resistosome can be activated by Rpi-amr3 upon detection of AVRamr3 homologs from other Phytophthora species. Mechanistic understanding of NRC resistosome formation will underpin engineering crops with durable disease resistance.

Sensor NLR immune proteins activate oligomerization of their NRC helpers in response to plant pathogens.

Nucleotide-binding domain leucine-rich repeat (NLR) immune receptors are important components of plant and metazoan innate immunity that can function as individual units or as pairs or networks. Upon activation, NLRs form multiprotein complexes termed resistosomes or inflammasomes. Although metazoan paired NLRs, such as NAIP/NLRC4, form hetero-complexes upon activation, the molecular mechanisms underpinning activation of plant paired NLRs, especially whether they associate in resistosome hetero-complexes, is unknown. In asterid plant species, the NLR required for cell death (NRC) immune receptor network is composed of multiple resistance protein sensors and downstream helpers that confer immunity against diverse plant pathogens. Here, we show that pathogen effector-activation of the NLR proteins Rx (confers virus resistance), and Bs2 (confers bacterial resistance) leads to oligomerization of their helper NLR, NRC2. Activated Rx does not oligomerize or enter into a stable complex with the NRC2 oligomer and remains cytoplasmic. In contrast, activated NRC2 oligomers accumulate in membrane-associated puncta. We propose an activation-and-release model for NLRs in the NRC immune receptor network. This points to a distinct activation model compared with mammalian paired NLRs.

Mutual potentiation of plant immunity by cell-surface and intracellular receptors.

The plant immune system involves cell-surface receptors that detect intercellular pathogen-derived molecules, and intracellular receptors that activate immunity upon detection of pathogen-secreted effector proteins that act inside the plant cell. Immunity mediated by surface receptors has been extensively studied1, but that mediated by intracellular receptors has rarely been investigated in the absence of surface-receptor-mediated immunity. Furthermore, interactions between these two immune pathways are poorly understood. Here, by activating intracellular receptors without inducing surface-receptor-mediated immunity, we analyse interactions between these two distinct immune systems in Arabidopsis. Pathogen recognition by surface receptors activates multiple protein kinases and NADPH oxidases, and we find that intracellular receptors primarily potentiate the activation of these proteins by increasing their abundance through several mechanisms. Likewise, the hypersensitive response that depends on intracellular receptors is strongly enhanced by the activation of surface receptors. Activation of either immune system alone is insufficient to provide effective resistance against the bacterial pathogen Pseudomonas syringae. Thus, immune pathways activated by cell-surface and intracellular receptors in plants mutually potentiate to activate strong defences against pathogens. These findings reshape our understanding of plant immunity and have broad implications for crop improvement.

Oligomerization of a plant helper NLR requires cell-surface and intracellular immune receptor activation.

Plant disease resistance involves both detection of microbial molecular patterns by cell-surface pattern recognition receptors and detection of pathogen effectors by intracellular NLR immune receptors. NLRs are classified as sensor NLRs, involved in effector detection, or helper NLRs required for sensor NLR signaling. TIR-domain-containing sensor NLRs (TNLs) require helper NLRs NRG1 and ADR1 for resistance, and helper NLR activation of defense requires the lipase-domain proteins EDS1, SAG101, and PAD4. Previously, we found that NRG1 associates with EDS1 and SAG101 in a TNL activation-dependent manner [X. Sun et al., Nat. Commun. 12, 3335 (2021)]. We report here how the helper NLR NRG1 associates with itself and with EDS1 and SAG101 during TNL-initiated immunity. Full immunity requires coactivation and mutual potentiation of cell-surface and intracellular immune receptor-initiated signaling [B. P. M. Ngou, H.-K. Ahn, P. Ding, J. D. G. Jones, Nature 592, 110-115 (2021), M. Yuan et al., Nature 592, 105-109 (2021)]. We find that while activation of TNLs is sufficient to promote NRG1-EDS1-SAG101 interaction, the formation of an oligomeric NRG1-EDS1-SAG101 resistosome requires the additional coactivation of cell-surface receptor-initiated defense. These data suggest that NRG1-EDS1-SAG101 resistosome formation in vivo is part of the mechanism that links intracellular and cell-surface receptor signaling pathways.

ATR2C ala2 from Arabidopsis-infecting downy mildew requires 4 TIR-NLR immune receptors for full recognition.

Arabidopsis Col-0 RPP2A and RPP2B confer recognition of Arabidopsis downy mildew (Hyaloperonospora arabidopsidis [Hpa]) isolate Cala2, but the identity of the recognized ATR2Cala2 effector was unknown. To reveal ATR2Cala2, an F2 population was generated from a cross between Hpa-Cala2 and Hpa-Noks1. We identified ATR2Cala2 as a non-canonical RxLR-type effector that carries a signal peptide, a dEER motif, and WY domains but no RxLR motif. Recognition of ATR2Cala2 and its effector function were verified by biolistic bombardment, ectopic expression and Hpa infection. ATR2Cala2 is recognized in accession Col-0 but not in Ler-0 in which RPP2A and RPP2B are absent. In ATR2Emoy2 and ATR2Noks1 alleles, a frameshift results in an early stop codon. RPP2A and RPP2B are essential for the recognition of ATR2Cala2. Stable and transient expression of ATR2Cala2 under 35S promoter in Arabidopsis and Nicotiana benthamiana enhances disease susceptibility. Two additional Col-0 TIR-NLR (TNL) genes (RPP2C and RPP2D) adjacent to RPP2A and RPP2B are quantitatively required for full resistance to Hpa-Cala2. We compared RPP2 haplotypes in multiple Arabidopsis accessions and showed that all four genes are present in all ATR2Cala2-recognizing accessions.

Preliminary Attainability Assessment of Real-World Data for Answering Major Clinical Research Questions in Breast Cancer Brain Metastasis: Framework Development and Validation Study.

BACKGROUND: In recent decades, real-world evidence (RWE) in oncology has rapidly gained traction for its potential to answer clinical questions that cannot be directly addressed by randomized clinical trials. Integrating real-world data (RWD) into clinical research promises to contribute to more sustainable research designs, including extension, augmentation, enrichment, and pragmatic designs. Nevertheless, clinical research using RWD is still limited because of concerns regarding the shortage of best practices for extracting, harmonizing, and analyzing RWD. In particular, pragmatic screening methods to determine whether the content of a data source is sufficient to answer the research questions before conducting the research with RWD have not yet been established. OBJECTIVE: We examined the PAR (Preliminary Attainability Assessment of Real-World Data) framework and assessed its utility in breast cancer brain metastasis (BCBM), which has an unmet medical need for data attainability screening at the preliminary step of observational studies that use RWD. METHODS: The PAR framework was proposed to assess data attainability from a particular data source during the early research process. The PAR framework has four sequential stages, starting with clinical question clarification: (1) operational definition of variables, (2) data matching (structural/semantic), (3) data screening and extraction, and (4) data attainability diagramming. We identified 5 clinical questions to be used for PAR framework evaluation through interviews and validated them with a survey of breast cancer experts. We used the Samsung Medical Center Breast Cancer Registry, a hospital-based real-time registry implemented in March 2021, leveraging the institution's anonymized and deidentified clinical data warehouse platform. The number of breast cancer patients in the registry was 45,129; it covered the period from June 1995 to December 2021. The registry consists of 24 base data marts that represent disease-specific breast cancer characteristics and care pathways. The outcomes included screening results of the clinical questions via the PAR framework and a procedural diagram of data attainability for each research question. RESULTS: Data attainability was tested for study feasibility according to the PAR framework with 5 clinical questions for BCBM. We obtained data sets that were sufficient to conduct studies with 4 of 5 clinical questions. The research questions stratified into 3 types when we developed data fields for clearly defined research variables. In the first, only 1 question could be answered using direct data variables. In the second, the other 3 questions required surrogate definitions that combined data variables. In the third, the question turned out to be not feasible for conducting further analysis. CONCLUSIONS: The adoption of the PAR framework was associated with more efficient preliminary clinical research using RWD from BCBM. Furthermore, this framework helped accelerate RWE generation through clinical research by enhancing transparency and reproducibility and lowering the entry barrier for clinical researchers.

Long-term outcomes in patients with advanced and/or metastatic non-small cell lung cancer who completed 2 years of immune checkpoint inhibitors or achieved a durable response after discontinuation without disease progression: Multicenter, real-world data (KCSG LU20-11).

BACKGROUND: Immune checkpoint inhibitors (ICIs) have shown significant improvements in patients with advanced non-small cell lung cancer (NSCLC). One of the major issues with ICIs is determining the optimal treatment duration. METHODS: This multicenter, retrospective study analyzed clinical outcomes in patients with NSCLC who completed 2 years of ICI therapy or were treated for more than 6 months and then discontinued ICIs without disease progression at 11 medical centers in Korea between August 2017 and December 2020. RESULTS: Ninety-six patients who completed 2 years of ICIs were reviewed. The median durations of treatment and follow-up were 24.0 and 33.9 months, respectively. The objective response rate (ORR) was 85.4%. The median progression-free survival (PFS) and overall survival (OS) periods were not reached. After completion, the PFS and OS rates were 81.1% and 96.4%, respectively, at 12 months. Forty-three patients were identified who discontinued ICIs without disease progression: 26 (60.5%) for adverse events and 17 (39.5%) for other causes. The median durations of treatment and follow-up were 10.5 and 21.2 months, respectively. The ORR was 90.7%. The median PFS and OS periods were not reached. After discontinuation, the PFS and OS rates were 71.0% and 90.0%, respectively, at 12 months. CONCLUSIONS: A significantly high proportion of patients who completed 2 years of ICI therapy continued to experience long-term PFS. Even if ICIs are discontinued after 6 months in patients without disease progression, they may achieve a durable response and facilitate long-term survival. LAY SUMMARY: The optimal treatment duration for immune checkpoint inhibitors (ICIs) remains to be determined. This study reports the long-term outcomes of patients with non-small cell lung cancer who completed 2 years of ICI therapy or achieved a durable response after the discontinuation of ICIs without disease progression in real-world practice. A significantly high proportion of patients who completed 2 years of ICIs continued to experience long-term progression-free survival. In addition, even if ICIs are discontinued after 6 months in patients without disease progression, they may achieve a durable response and facilitate long-term survival.

Tyrosine Kinase Inhibitor Activity in Patients with NSCLC Harboring Uncommon EGFR Mutations: A Retrospective International Cohort Study (UpSwinG).

BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are standard of care for patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC) with common mutations (Del19 or L858R); however, 7%-23% of NSCLC tumors harbor uncommon EGFR mutations. These mutations are highly heterogeneous, and developments in detection techniques are helping to identify mutations with little or no clinical data. PATIENTS AND METHODS: In this retrospective, global, multi-center study (NCT04179890), existing health records were identified for consecutive EGFR TKI-naïve patients with uncommon EGFR mutations (T790M, ex20ins, major uncommon [G719X, L861Q, or S768I], or "other" mutations; compound mutations) treated with erlotinib, gefitinib, afatinib, or osimertinib in first or second line. Endpoints included time-to-treatment failure (TTF), objective response rate (ORR), and overall survival (OS). RESULTS: Overall, 246 patients (median age: 69.5 years; Asian: 84%) were included from 9 countries. Most patients (92%) received an EGFR TKI as first-line therapy; 54%, 43% and 3% received afatinib, first-generation TKIs, and osimertinib, respectively. Median TTF and OS with EGFR TKIs were 9.9 and 24.4 months; ORR was 43%. In patients treated with first-line chemotherapy (n = 20), median TTF and ORR were 6.6 months and 41%. Outcomes were most favorable in patients with major uncommon or compound mutations. Overall, TTF was 11.3 months with afatinib and 8.8 months with first-generation EGFR TKIs across mutation categories. In most mutation categories, median OS was >2 years. CONCLUSION: In a real-world setting, EGFR TKIs were the preferred treatment option in patients with uncommon EGFR mutations; strongest outcomes were seen in patients with major uncommon and compound mutations.

Discussing POLST-facilitated hospice care enrollment in patients with terminal cancer.

PURPOSE: A multicenter prospective study to evaluate the feasibility of Physician Orders for Life-Sustaining Treatment (POLST) in oncology practice was conducted between June and December 2017. Factors associated with POLST completion and follow-up outcomes were analyzed. METHODS: Patients with terminal cancer, aged ≥ 20 years and capable of communicating, were enrolled from seven hospitals. Demographic data were collected and updated in February 2021. Descriptive statistics and logistic regression analyses were conducted. RESULTS: Among 336 patients, 105 (31.3%) completed POLST, which was more common in male (p = 0.029), patients with better performance (p < 0.001), longer duration of follow-up (p = 0.037), and those living with children (p = 0.023). Male (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.17-3.51; p = 0.012), having good performance status (OR, 2.38; 95% CI, (1.35-4.19); p = 0.003), transferred from other departments (OR, 0.50; 95% CI, (0.26-0.98); p = 0.045), and living with children (OR, 1.94; 95% CI, (1.11-3.47); p = 0.020) were significant predictors of POLST completion. Patients who completed POLST were more likely to enroll in hospice care (p = 0.012) or experience out-of-hospital death (p = 0.016) at end-of-life (EOL). POLST completion showed a strong association with hospice enrollment at EOL (OR, 2.61; 95% CI, (1.08-6.32); p = 0.033). CONCLUSION: Gender, patient performance, timing of POLST discussion, and type of household were associated with POLST completion. Earlier discussions on POLST could reinforce hospice enrollment or non-aggressive EOL care.

Association between continuous deep sedation and survival time in terminally ill cancer patients.

PURPOSE: Our study aimed to evaluate the association between CDS and survival time using the likelihood of receiving CDS to select a matched non-CDS group through an accurate measurement of survival time based on initiation of CDS. METHODS: A retrospective cohort study was performed using an electronic database to collect data regarding terminally ill cancer patients admitted to a specialized palliative care unit from January 2012 to December 2016. We first used a Cox proportional hazard model with receiving CDS as the outcome to identify individuals with the highest plausibility of receiving CDS among the non-CDS group (n = 663). We then performed a multiple regression analysis comparing the CDS group (n = 311) and weighted non-CDS group (n = 311), using initiation of CDS (actual for the CDS group; estimated for the non-CDS group) as the starting time-point for measuring survival time. RESULTS: Approximately 32% of participants received CDS. The most common indications were delirium or agitation (58.2%), intractable pain (28.9%), and dyspnea (10.6%). Final multiple regression analysis revealed that survival time was longer in the CDS group than in the non-CDS group (Exp(ß), 1.41; P < 0.001). Longer survival with CDS was more prominent in females, patients with renal dysfunction, and individuals with low C-reactive protein (CRP) or ferritin, compared with their counterpart subgroup. CONCLUSIONS: CDS was not associated with shortened survival; instead, it was associated with longer survival in our terminally ill cancer patients. Further studies in other populations are required to confirm or refute these findings.

A Randomized Controlled Trial of Epidermal Growth Factor Ointment for Treating Epidermal Growth Factor Receptor Inhibitor-Induced Skin Toxicities.

BACKGROUND: The efficacy of epidermal growth factor (EGF) receptor (EGFR) inhibitors in patients with non-small cell lung cancer (NSCLC), pancreatic cancer (PC), or colorectal cancer (CRC) has been demonstrated. However, dermatological reactions to these inhibitors can cause significant physical and psychosocial discomfort. The objective of the present study was to evaluate the efficacy of EGF ointment for EGFR inhibitor-related skin adverse events (ERSEs). MATERIALS AND METHODS: This placebo-controlled, double-blind, multicenter, pilot phase III trial enrolled patients with NSCLC, PC, or CRC treated with EGFR inhibitors. Patients with grade ≥2 ERSEs were included. Patients were randomized to three treatment arms: arm 1, placebo; arm 2, 1 ppm of EGF ointment; and arm 3, 20 ppm of EGF ointment. Patients applied ointment to their skin lesions twice daily. RESULTS: Efficacy evaluation was available for 80 patients (9 for PC, 28 for NSCLC, and 43 for CRC). Responses were 44.4% in arm 1, 61.5% in arm 2, and 77.8% in arm 3. There was a linear correlation between EGF concentrations and responses (p = .012). Quality of life (QoL) was assessed for 74 patients. Maximum changes in composite scores by Skindex-16 after treatment were significantly different among arms (mean ± SD: -5.2 ± 8.6 for arm 1, -11.7 ± 14.2 for arm 2, and - 18.6 ± 17.7 for arm 3; p = .008). EGF arms showed significant improvement in emotions (p = .005) and functioning (p = .044) scores over the placebo arm. CONCLUSION: EGF ointment is effective for managing ERSEs. It can also improve patients' QoL compared with placebo. Clinical trial identification number. NCT02284139 IMPLICATIONS FOR PRACTICE: Patients with non-small cell lung cancer, pancreatic cancer, or colorectal cancer who are treated with epidermal growth factor (EGF) receptor (EGFR) inhibitors may experience dermatologic reactions to their treatment. This study investigated the benefit of an EGF ointment in the treatment of these adverse events and observed the ointment to be effective in managing EGFR inhibitor-related skin adverse events.

Estradiol-inducible AvrRps4 expression reveals distinct properties of TIR-NLR-mediated effector-triggered immunity.

Plant nucleotide-binding domain, leucine-rich repeat receptor (NLR) proteins play important roles in recognition of pathogen-derived effectors. However, the mechanism by which plant NLRs activate immunity is still largely unknown. The paired Arabidopsis NLRs RRS1-R and RPS4, that confer recognition of bacterial effectors AvrRps4 and PopP2, are well studied, but how the RRS1/RPS4 complex activates early immediate downstream responses upon effector detection is still poorly understood. To study RRS1/RPS4 responses without the influence of cell surface receptor immune pathways, we generated an Arabidopsis line with inducible expression of the effector AvrRps4. Induction does not lead to hypersensitive cell death response (HR) but can induce electrolyte leakage, which often correlates with plant cell death. Activation of RRS1 and RPS4 without pathogens cannot activate mitogen-associated protein kinase cascades, but still activates up-regulation of defence genes, and therefore resistance against bacteria.

Treatment strategy and outcomes in locally advanced head and neck squamous cell carcinoma: a nationwide retrospective cohort study (KCSG HN13-01).

BACKGROUND: By investigating treatment patterns and outcomes in locally advanced head and neck squamous cell carcinoma (LA-HNSCC), we aimed at providing valuable insights into the optimal therapeutic strategy for physicians in real-world practice. METHODS: This is a multi-institutional study enrolled the patients with stage III to IVB LA-HNSCC, except for nasopharyngeal carcinoma, from 2004 to 2015 in thirteen referral hospitals capable of multidisciplinary care. RESULTS: A total of 445 LA-HNSCC patients were analyzed. The median age was 61 years (range, 24-89). The primary tumor location was the oropharynx in 191 (43%), oral cavity in 106 (24%), hypopharynx in 64 (14%), larynx in 57 (13%) and other sites in 27 (6%). The most common stage was T2 in 172 (39%), and N2 in 245 (55%). Based on treatment intents, 229 (52%) of the patients received definitive concurrent chemoradiotherapy (CCRT) and 187 (42%) underwent surgery. Approximately 158 (36%) of the study population received induction chemotherapy (IC). Taken together, 385 (87%) of the patients underwent combined therapeutic modalities. The regimen for definitive CCRT was weekly cisplatin in 58%, 3-weekly cisplatin in 28% and cetuximab in 3%. The preferred regimen for IC was docetaxel with cisplatin in 49%, and docetaxel, cisplatin plus fluorouracil in 27%. With a median follow-up of 39 months, one-year and two-year survival rates were 89 and 80%, respectively. Overall survival was not significantly different between CCRT and surgery group (p = 0.620). CONCLUSIONS: In patients with LA-HNSCC, the majority of patients received combined therapeutic modalities. Definitive CCRT, IC then definitive CCRT, and surgery followed by adjuvant CCRT or radiotherapy are the preferred multidisciplinary strategies in real-world practice.

Palbociclib plus exemestane with gonadotropin-releasing hormone agonist versus capecitabine in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer (KCSG-BR15-10): a multicentre, open-label, randomised, phase 2 trial.

BACKGROUND: Endocrine treatment is recommended by clinical guidelines as the preferred treatment option for premenopausal as well as postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer. In real-world clinical practice, however, a substantial number of patients are treated with chemotherapy. We aimed to compare the clinical antitumour activity and safety of palbociclib plus endocrine therapy with that of capecitabine chemotherapy in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer. METHODS: This multicentre, open-label, randomised, phase 2 study was done in 14 academic institutions in South Korea. Premenopausal women aged 19 years or older with hormone receptor-positive, HER2-negative breast cancer that had relapsed or progressed during previous tamoxifen therapy and with an Eastern Cooperative Oncology Group performance status of 0-2 were included. One line of previous chemotherapy for metastatic breast cancer was allowed. Patients were randomly assigned, using a random permuted block design (with a block size of two), to receive palbociclib plus combination endocrine therapy (oral exemestane 25 mg per day for 28 days and oral palbociclib 125 mg per day for 21 days every 4 weeks plus leuprolide 3·75 mg subcutaneously every 4 weeks) or chemotherapy (oral capecitabine 1250 mg/m2 twice daily for 2 weeks every 3 weeks). Randomisation was stratified by previous chemotherapy for metastatic breast cancer and visceral metastasis. The primary endpoint was progression-free survival. All analyses were done in a modified intention-to-treat population that excluded patients who did not receive study medication. This study is registered with ClinicalTrials.gov, NCT02592746, and is ongoing for follow-up of overall survival. FINDINGS: Between June 15, 2016, and Dec 10, 2018, 189 patients were enrolled, of whom 184 were randomly assigned to the palbociclib plus endocrine therapy group (n=92) or the capecitabine group (n=92). Six patients in the capecitabine group withdrew from the study before drug administration; therefore, 92 patients in the palbociclib plus endocrine therapy group and 86 patients in the capecitabine group were included in the modified intention-to-treat analyses. 46 (50%) of 92 patients in the palbociclib plus endocrine therapy group and 45 (51%) of 92 in the capecitabine group were treatment naive for metastatic breast cancer. During a median follow-up of 17 months (IQR 9-22), median progression-free survival was 20·1 months (95% CI 14·2-21·8) in the palbociclib plus endocrine therapy group versus 14·4 months (12·1-17·0) in the capecitabine group (hazard ratio 0·659 [95% CI 0·437-0·994], one-sided log-rank p=0·0235). Treatment-related grade 3 or worse neutropenia was more common in the palbociclib plus endocrine therapy group than in the capecitabine group (69 [75%] of 92 vs 14 [16%] of 86 patients). 2 (2%) patients in the palbociclib plus endocrine therapy group and 15 (17%) patients in the capecitabine group had treatment-related serious adverse events. No treatment-related deaths occurred. INTERPRETATION: Exemestane plus palbociclib with ovarian function suppression showed clinical benefit compared with capecitabine in terms of improved progression-free survival in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer. Palbociclib plus exemestane with ovarian suppression is an active treatment option in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer who have been pretreated with tamoxifen. FUNDING: Pfizer, Shinpoong, and Daewoong Korea and Takeda.

Reflective Fourier ptychographic microscopy using a parabolic mirror.

Fourier ptychography uses a phase retrieval algorithm to reconstruct a high-resolution image with a wide field-of-view. Reflective-type Fourier ptychographic microscopy (FPM) is expected to be very useful for surface inspection, but the reported methods have several limitations. We propose a darkfield illuminator for reflective FPM consisting of a parabolic mirror and a flat LED panel. This increases the signal-to-noise ratio of the acquired images because the normal beam of each LED is directed toward the object. Furthermore, the LEDs do not have to be far from the object because they are collimated by the parabolic surface before illumination. Based on this, a reflective FPM with a synthesized numerical aperture (NA) of 1.06 was achieved, which is the highest value by reflective FPM as far as we know. To validate this experimentally, we measured a USAF reflective resolution target and reconstructed a high-resolution image. This resolved up to the period of 488 nm, which corresponds to the synthesized NA. Additionally, an integrated circuit was measured to demonstrate the effectiveness of surface inspection of the proposed system.

Functional characterization of chaperonin containing T-complex polypeptide-1 and its conserved and novel substrates in Arabidopsis.

Chaperonin containing T-complex polypeptide-1 (CCT) is an evolutionarily conserved chaperonin multi-subunit complex that mediates protein folding in eukaryotes. It is essential for cell growth and survival in yeast and mammals, with diverse substrate proteins. However, only a few studies on plant CCT have been reported to date, due to the essentiality of CCT subunit genes and the large size of the complex. Here, we have investigated the structure and function of the Arabidopsis CCT complex in detail. The plant CCT consisted of eight subunits that assemble to form a high-molecular-mass protein complex, shown by diverse methods. CCT-deficient cells exhibited depletion of cortical microtubules, accompanied by a reduction in cellular α- and ß-tubulin levels due to protein degradation. Cycloheximide-chase assays suggested that CCT is involved in the folding of tubulins in plants. Furthermore, CCT interacted with PPX1, the catalytic subunit of protein phosphatase 4, and may participate in the folding of PPX1 as its substrate. CCT also interacted with Tap46, a regulatory subunit of PP2A family phosphatases, but Tap46 appeared to function in PPX1 stabilization, rather than as a CCT substrate. Collectively, our findings reveal the essential functions of CCT chaperonin in plants and its conserved and novel substrates.

The subfamily II catalytic subunits of protein phosphatase 2A (PP2A) are involved in cortical microtubule organization.

MAIN CONCLUSION: The subfamily II catalytic subunits of protein phosphatase 2A (PP2A) regulate the cortical microtubule dynamics in Arabidopsis, through interaction with TONNEAU2 (TON2)/FASS and modulation of α-tubulin dephosphorylation. Protein phosphatase 2A is a major protein phosphatase in eukaryotes that dephosphorylates many different substrates to regulate their function. PP2A is assembled into a heterotrimeric complex of scaffolding A subunit, regulatory B subunit, and catalytic C subunit. Plant PP2A catalytic C subunit (PP2AC) isoforms are classified into two subfamilies. In this study, we investigated the cellular functions of the Arabidopsis PP2AC subfamily II genes PP2AC-3 and PP2AC-4, particularly regarding the cortical microtubule (MT) organization. PP2AC-3 and PP2AC-4 strongly interacted with the B'' regulatory subunit TON2. Simultaneous silencing of PP2AC-3 and PP2AC-4 by virus-induced gene silencing (PP2AC-3,4 VIGS) significantly altered plant morphology in Arabidopsis, increasing cell numbers in leaves and stems. The leaf epidermis of PP2AC-3,4 VIGS plants largely lost its jigsaw-puzzle shape and exhibited reduced trichome branch numbers. VIGS of PP2AC-3,4 in Arabidopsis transgenic plants that expressed GFP-fused ß-tubulin 6 isoform (GFP-TUB6) for the visualization of MTs caused a reduction in the cortical MT array density in the pavement cells. VIGS of TON2 also led to similar cellular phenotypes and cortical MT patterns compared with those after VIGS of PP2AC-3,4, suggesting that PP2AC-3,4 and their interaction partner TON2 play a role in cortical MT organization in leaf epidermal cells. Furthermore, silencing of PP2AC-3,4 did not affect salt-induced phosphorylation of α-tubulin but delayed its dephosphorylation after salt removal. The reappearance of cortical MT arrays after salt removal was impaired in PP2AC-3,4 VIGS plants. These results suggest an involvement of PP2AC subfamily II in the regulation of cortical MT dynamics under normal and salt-stress conditions in Arabidopsis.

Functional characterization of chloroplast-targeted RbgA GTPase in higher plants.

KEY MESSAGE: Plant RbgA GTPase is targeted to chloroplasts and co-fractionated with chloroplast ribosomes, and plays a role in chloroplast rRNA processing and/or ribosome biogenesis. Ribosome Biogenesis GTPase A (RbgA) homologs are evolutionarily conserved GTPases that are widely distributed in both prokaryotes and eukaryotes. In this study, we investigated functions of chloroplast-targeted RbgA. Nicotiana benthamiana RbgA (NbRbgA) and Arabidopsis thaliana RbgA (AtRbgA) contained a conserved GTP-binding domain and a plant-specific C-terminal domain. NbRbgA and AtRbgA were mainly localized in chloroplasts, and possessed GTPase activity. Since Arabidopsis rbgA null mutants exhibited an embryonic lethal phenotype, virus-induced gene silencing (VIGS) of NbRbgA was performed in N. benthamiana. NbRbgA VIGS resulted in a leaf-yellowing phenotype caused by disrupted chloroplast development. NbRbgA was mainly co-fractionated with 50S/70S ribosomes and interacted with the chloroplast ribosomal proteins cpRPL6 and cpRPL35. NbRbgA deficiency lowered the levels of mature 23S and 16S rRNAs in chloroplasts and caused processing defects. Sucrose density gradient sedimentation revealed that NbRbgA-deficient chloroplasts contained reduced levels of mature 23S and 16S rRNAs and diverse plastid-encoded mRNAs in the polysomal fractions, suggesting decreased protein translation activity in the chloroplasts. Interestingly, NbRbgA protein was highly unstable under high light stress, suggesting its possible involvement in the control of chloroplast ribosome biogenesis under environmental stresses. Collectively, these results suggest a role for RbgA GTPase in chloroplast rRNA processing/ribosome biogenesis, affecting chloroplast protein translation in higher plants.

Prevalence of and Factors Associated with Sarcopenia in Korean Cancer Survivors: Based on Data Obtained by the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011.

Using a representative dataset from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2011, we analyzed anthropometric and dual-energy X-ray absorptiometry (DXA)-determined body composition findings for 493 cancer survivors (mean age a61.1 ± 12.6 years; 35.7% male). A much higher proportion of men (30.1%) than women (0.6%) met the criteria of sarcopenia. Subjects with a history of lung cancer, genitourinary cancer, or gastric cancer were prone to develop sarcopenia (31.6%, 26.3%, and 21.4%, respectively). Furthermore, sarcopenia was more prevalent among elderly (≥65 years; P < 0.001), those with a lower BMI level (<23 kg/m2; P < 0.001), heavy drinker (P = 0.012), or smoker (P < 0.001), and those with inadequate intakes of protein (P = 0.017) and vitamin A (P = 0.024). Multivariable logistic analyses revealed sarcopenia was significantly associated with male gender (odds ratio [OR], 68.14; 95% CI, 15.52-299.13), a BMI of <23 kg/m2 (OR 35.93, 95% CI, 8.24-156.67), and inadequate protein intake (OR 3.07, 95% CI, 1.30-7.22); these factors are significant predictors of sarcopenia in Korean cancer survivors.

Risk of cancer among patients with depressive disorder: a meta-analysis and implications.

OBJECTIVE: The question of cancer risk in individuals with depression is unclear, primarily because of the heterogeneity of the assessment of depression in the published literature. To clarify the mixed findings, this analysis was limited to articles that used a reliable method of ascertaining depressive disorder. METHODS: We searched PubMed, EMBASE, and the Cochrane Library to identify studies investigating the effect of depression on subsequent risk of cancer, defining depression based on the criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM) and/or the International Classification of Disease (ICD). We calculated a pooled odds ratio (OR) for developing cancer with the 95% confidence interval (CI). RESULTS: Nine studies fulfilled the eligibility criteria. In a random-effects model, patients with depressive disorder were at increased risk for cancer (OR, 1.26; 95% CI, 1.06-1.50, P = 0.01). However, a significant effect was observed only in low-quality studies (OR, 1.31; 95% CI, 1.05-1.63, P = 0.018), and not in high-quality studies (OR, 1.15; 95% CI, 0.85-1.56, P = 0.366). CONCLUSION: Our results did not demonstrate that people with depressive disorder are at increased risk for developing cancer. Well-designed prospective studies of recurrent or persistent depressive disorder that control for lifestyle factors including smoking are warranted. Copyright © 2016 John Wiley & Sons, Ltd.