Rice SRO1a contributes to Xanthomonas TAL effector-mediated expression of host susceptible gene.

Xanthomonas species infect many important crops and cause huge yield loss. These pathogens deliver transcription activator-like (TAL) effectors into the cytoplasm of plant cells. TAL effectors move to host nuclei, directly bind to the promoters of host susceptible genes, and activate their transcription. However, the molecular mechanisms by which TAL effectors induce host transcription remain unclear. We herein demonstrated that TAL effectors interacted with the SIMILAR TO RCD ONE (SRO) family proteins OsSRO1a and OsSRO1b in nuclei. A transactivation assay using rice protoplasts indicated that OsSRO1a and OsSRO1b enhanced the activation of the OsSWEET14 promoter by the TAL effector AvrXa7. The AvrXa7-mediated expression of OsSWEET14 was significantly reduced in ossro1a mutants. However, the overexpression of OsSRO1a increased disease resistance by up-regulating the expression of defense-related genes, such as WRKY62 and PBZ1. This was attributed to OsSRO1a and OsSRO1b also enhancing the transcriptional activity of WRKY45, a direct regulator of WRKY62 expression. Therefore, OsSRO1a and OsSRO1b appear to positively contribute to transcription mediated by bacterial TAL effectors and rice transcription factors.

A randomized double-blind placebo-controlled trial of an inhibitor of plasminogen activator inhibitor-1 (TM5614) in mild to moderate COVID-19.

An inhibitor of plasminogen activator inhibitor (PAI)-1, TM5614, inhibited thrombosis, inflammation, and fibrosis in several experimental mouse models. To evaluate the efficacy and safety of TM5614 in human COVID-19 pneumonia, phase IIa and IIb trials were conducted. In an open-label, single-arm trial, 26 Japanese COVID-19 patients with mild to moderate pneumonia were treated with 120-180 mg of TM5614 daily, and all were discharged without any notable side effects. Then, a randomized, double-blind, placebo-controlled trial was conducted in Japanese COVID-19 patients with mild to moderate pneumonia. The number of study participants was set to be 50 in each arm. Even after extension of the enrollment period, the number of study participants did not reach the initially intended sample size, and 75 patients were enrolled in the study. The total oxygenation scale from Day 1 to Day 14 as the primary endpoint was 1.5 in the TM5614 group vs 4.0 in the placebo group (p = 0.22), and the number of days of oxygen administration required as the secondary endpoint was 2.0 days in the TM5614 group vs 3.5 days in the placebo group (p = 0.34). Further studies will be necessary to verify the efficacy of PAI-1 inhibition for the treatment of COVID-19 pneumonia.Clinical trial registration: Two studies were conducted: a prospective, multicenter, open-label phase II study at https://jrct.niph.go.jp (jRCT2021200018) (First registration date 18/08/2020) and a prospective, multicenter, randomized, double-blind, placebo-controlled, phase II study at https://jrct.niph.go.jp (jRCT2021210006) (First registration date 28/05/2021).

Clinicoradiological course of abemaciclib-induced pneumonitis with histology findings.

A woman in her late 40s presented with multiple abnormal shadows on high-resolution CT (HRCT), was treated with abemaciclib for recurrent right breast cancer post-surgery and chemoradiation therapy. During the 10-month chemotherapy, HRCT revealed a recurrent pattern of a partly appearing and disappearing organising pneumonia pattern without clinical symptoms. Bronchoalveolar lavage analysis revealed lymphocytosis, while transbronchial lung biopsy revealed alveolitis with epithelial cell injury. Based on the diagnosis of drug-induced pneumonitis due to abemaciclib, the discontinuation of abemaciclib and administration of prednisolone were effective. Abnormal shadow on HRCT disappeared gradually, while elevated Krebs von den Lungen (KL)-6 and surfactant protein (SP)-D levels were restored to normal range. This is the first case report of abemaciclib-induced pneumonitis with histology findings. Since the severity of abemaciclib-induced pneumonitis ranges from mild to fatal, regular monitoring of pneumonitis with radiography, HRCT, and measurement of KL-6 and SP-D levels should be considered.

The rice OsERF101 transcription factor regulates the NLR Xa1-mediated immunity induced by perception of TAL effectors.

Plant nucleotide-binding leucine-rich repeat receptors (NLRs) initiate immune responses by recognizing pathogen effectors. The rice gene Xa1 encodes an NLR with an N-terminal BED domain, and recognizes transcription activator-like (TAL) effectors of Xanthomonas oryzae pv oryzae (Xoo). Our goal here was to elucidate the molecular mechanisms controlling the induction of immunity by Xa1. We used yeast two-hybrid assays to screen for host factors that interact with Xa1 and identified the AP2/ERF-type transcription factor OsERF101/OsRAP2.6. Molecular complementation assays were used to confirm the interactions among Xa1, OsERF101 and two TAL effectors. We created OsERF101-overexpressing and knockout mutant lines in rice and identified genes differentially regulated in these lines, many of which are predicted to be involved in the regulation of response to stimulus. Xa1 interacts in the nucleus with the TAL effectors and OsERF101 via the BED domain. Unexpectedly, both the overexpression and the knockout lines of OsERF101 displayed Xa1-dependent, enhanced resistance to an incompatible Xoo strain. Different sets of genes were up- or downregulated in the overexpression and knockout lines. Our results indicate that OsERF101 regulates the recognition of TAL effectors by Xa1, and functions as a positive regulator of Xa1-mediated immunity. Furthermore, an additional Xa1-mediated immune pathway is negatively regulated by OsERF101.

Cooperative regulation of PBI1 and MAPKs controls WRKY45 transcription factor in rice immunity.

The U-box type ubiquitin ligase PUB44 positively regulates pattern-triggered immunity in rice. Here, we identify PBI1, a protein that interacts with PUB44. Crystal structure analysis indicates that PBI1 forms a four-helix bundle structure. PBI1 also interacts with WRKY45, a master transcriptional activator of rice immunity, and negatively regulates its activity. PBI1 is degraded upon perception of chitin, and this is suppressed by silencing of PUB44 or expression of XopP, indicating that PBI1 degradation depends on PUB44. These data suggest that PBI1 suppresses WRKY45 activity when cells are in an unelicited state, and during chitin signaling, PUB44-mediated degradation of PBI1 leads to activation of WRKY45. In addition, chitin-induced MAP kinase activation is required for WRKY45 activation and PBI1 degradation. These results demonstrate that chitin-induced activation of WRKY45 is regulated by the cooperation between MAP kinase-mediated phosphorylation and PUB44-mediated PBI1 degradation.

Pathogen- and plant-derived peptides trigger plant immunity.

Plants are constantly exposed to pathogens in their immediate environment. Plants sense the invasion of pathogens by recognizing the components including peptide fragments derived from pathogens, known as pathogen-associated molecular patterns (PAMPs). Plants also produce immunogenic peptides called phytocytokines that regulate immune responses. These molecules are recognized by pattern recognition receptors (PRRs) at plasma membrane. Activated PRRs induce a variety of immune responses including production of reactive oxygen species (ROS), induction of Ca2+ influx and activation of mitogen activated protein kinases (MAPKs). Pattern-triggered immunity (PTI) wards off microbes and pests. In this review, we summarize recent our advances in understanding how the peptide fragments are generated and perceived by plant PRRs at cell surface, and the activated PRRs transduce the downstream immune signaling.

Novel assays to monitor gene expression and protein-protein interactions in rice using the bioluminescent protein, NanoLuc.

Luciferases have been widely utilized as sensitive reporters to monitor gene expression and protein-protein interactions. Compared to firefly luciferase (Fluc), a recently developed luciferase, Nanoluciferase (NanoLuc or Nluc), has several superior properties such as a smaller size and stronger luminescence activity. We compared the reporter properties of Nluc and Fluc in rice (Oryza sativa). In both plant-based two-hybrid and split luc complementation (SLC) assays, Nluc activity was detected with higher sensitivity and specificity than that with Fluc. To apply Nluc to research involving the photoperiodic regulation of flowering, we made a knock-in rice plant in which the Nluc coding region was inserted in-frame with the OsMADS15 gene, a target of the rice florigen Hd3a. Strong Nluc activity in response to Hd3a, and in response to change in day length, was detected in rice protoplasts and in a single shoot apical meristem, respectively. Our results indicate that Nluc assay systems will be powerful tools to monitor gene expression and protein-protein interaction in plant research.

[A CASE OF BIRD-RELATED HYPERSENSITIVITY PNEUMONITIS THAT DEVELOPED IN SUBACUTE COURSE AND PRESENTED WITH ACUTE FINDINGS].

A 52-year-old woman presented to a clinic in late August with exacerbated fatigue and dyspnea on exertion for several months. Then, she was referred and admitted to our hospital in late September. Her chest CT showed bilateral diffuse centrilobular micronodules. In her detailed clinical history, she had kept budgerigars indoors for 15 years. These findings suggested she had a bird-related hypersensitivity pneumonitis (BRHP). By a site environmental investigation, 40 budgerigars were kept in a single breeding room and there were large amounts of droppings on the floor. Serum specific antibody for bird antigens and an environmental provocation test were positive. Bronchoalveolar lavage fluid showed lymphocytosis and a low CD4/CD8 ratio. Trans-bronchial lung biopsy showed lymphocytic infiltration of the alveolar wall and interlobular septa. After antigen avoidance as hospitalization, her symptoms and abnormal shadow improved. From these results, the patient was diagnosed as an acute BRHP.BRHP often presents a chronic onset. This case was diagnosed as an acute type despite the 15-years of budgerigars breeding. Increased exposure of antigens due to lack of cleaning after several days' antigen avoidance was suspected with one of the causes of acute onset.

Clinical course of 2019 novel coronavirus disease (COVID-19) in individuals present during the outbreak on the Diamond Princess cruise ship.

We investigated the clinical course of individuals with 2019 novel coronavirus disease (COVID-19) who were transferred from the Diamond Princess cruise ship to 12 local hospitals. The conditions and clinical courses of patients with pneumonia were compared with those of patients without pneumonia. Among 70 patients (median age: 67 years) analyzed, the major symptoms were fever (64.3%), cough (54.3%), and general fatigue (24.3%). Forty-three patients (61.4%) had pneumonia. Higher body temperature, heart rate, and respiratory rate as well as higher of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and C-reactive protein (CRP) levels and lower serum albumin level and lymphocyte count were associated with the presence of pneumonia. Ground-glass opacity was found in 97.7% of the patients with pneumonia. Patients were administered neuraminidase inhibitors (20%), lopinavir/ritonavir (32.9%), and ciclesonide inhalation (11.4%). Mechanical ventilation and veno-venous extracorporeal membrane oxygenation was performed on 14 (20%) and 2 (2.9%) patients, respectively; two patients died. The median duration of intubation was 12 days. The patients with COVID-19 transferred to local hospitals during the outbreak had severe conditions and needed close monitoring. The severity of COVID-19 depends on the presence of pneumonia. High serum LDH, AST and CRP levels and low serum albumin level and lymphocyte count were found to be predictors of pneumonia. It was challenging for local hospitals to admit and treat these patients during the outbreak of COVID-19. Assessment of severity was crucial to manage a large number of patients.

OsDRE2 contributes to chitin-triggered response through its interaction with OsRLCK185.

The rice receptor-like cytoplasmic kinase 185 (OsRLCK185) interacts with the chitin receptor complex OsCERK1/CEBiP and positively regulates chitin-induced immune responses including MAP kinase activation, ROS production and defense gene expression. To elucidate the regulatory mechanisms of OsRLCK185-mediated immunity, we searched for interactors of OsRLCK185. OsDRE2a, rice homologs of the yeast Dre2 protein, were identified as novel interactors of OsRLCK185. OsDRE2a interacted with OsRLCK185 at plasma membrane. The conserved cysteine residues in CIAPIN1 domain of OsDRE2a were essential for tight interaction of OsRLCK185. OsDRE2a was phosphorylated by OsRLCK185. The expression of OsDRE2a and OsDRE2b was induced after chitin treatment. Reduction of OsDRE2a and OsDRE2b mRNA levels by RNA interference resulted in the decreased chitin-induced ROS production. Thus, it is likely that OsDRE2 regulates OsRLCK185-mediated immune responses.

Treatment of asthma in smokers: A questionnaire survey in Japanese clinical practice.

BACKGROUND: Cigarette smoking in patients with asthma leads to poor symptom control. As patients who are current smokers have been excluded from enrollment in many clinical trials on asthma, there are few reports on the treatment in current smokers with asthma. In this study, we aimed to assess how respiratory physicians manage asthma in current smokers in Japan. METHODS: Respiratory physicians in 16 Japanese hospitals answered a questionnaire on treatment for patients with asthma between December 2014 and February 2015. Medical records were reviewed for 1756 patients with asthma. RESULTS: The mean patient age was 61.1 years, and 62.9% of the patients were female. A total of 102 patients (5.8%) were current smokers, and 546 patients (31.1%) were former smokers. Long-acting muscarinic antagonists (LAMA) were prescribed more frequently for current smokers with asthma than for former smokers and never smokers with asthma (10.8% vs 4.6%, p = 0.01, 10.8% vs 3.8%, p < 0.01). In contrast, macrolides were prescribed more frequently for former smokers and never smokers with asthma than for current smokers with asthma (7.7% vs 1.0%, p = 0.01, 6.4% vs 1.0%, p = 0.03). Triple therapy, i.e., inhaled corticosteroids, long-acting beta agonists, and LAMA concomitantly, was prescribed for current smokers with asthma more frequently than for former smokers and never smokers with asthma (9.8% vs 4.0%, p = 0.01, 9.8% vs 3.3%, p < 0.01). CONCLUSIONS: According to this survey, current smokers with asthma received more intensive therapy, including LAMA, than did former smokers with asthma.

PRR Cross-Talk Jump Starts Plant Immunity.

Plants remember information related to previous pathogen infection as immunological memory, leading to a primed state of enhanced immune responses. In this issue of Cell Host & Microbe, Gong et al. (2019) discover that immune priming is established through crosstalk between cell-surface co-receptors upon MAMP perception.

In vivo monitoring of plant small GTPase activation using a Förster resonance energy transfer biosensor.

BACKGROUND: Small GTPases act as molecular switches that regulate various plant responses such as disease resistance, pollen tube growth, root hair development, cell wall patterning and hormone responses. Thus, to monitor their activation status within plant cells is believed to be the key step in understanding their roles. RESULTS: We have established a plant version of a Förster resonance energy transfer (FRET) probe called Ras and interacting protein chimeric unit (Raichu) that can successfully monitor activation of the rice small GTPase OsRac1 during various defence responses in cells. Here, we describe the protocol for visualizing spatiotemporal activity of plant Rac/ROP GTPase in living plant cells, transfection of rice protoplasts with Raichu-OsRac1 and acquisition of FRET images. CONCLUSIONS: Our protocol should be adaptable for monitoring activation for other plant small GTPases and protein-protein interactions for other FRET sensors in various plant cells.

Elasticity of the pronator teres muscle in youth baseball players with elbow injuries: evaluation using ultrasound strain elastography.

BACKGROUND: Although the pronator teres muscle, a major dynamic stabilizer of elbow valgus stress during throwing, frequently presents stiffness, its relationship with elbow injuries in youth baseball players is unknown. This study investigated the relationship between the elasticity of the pronator teres muscle and elbow injuries in youth baseball players. METHODS: The strain ratio (SR) of 15 individuals with osteochondritis dissecans of the humeral capitellum (OCD group), 67 individuals with medial epicondylar fragmentation (medial injury group), and 115 healthy individuals (control group) was measured as the index of the elasticity of the pronator teres muscle using ultrasound strain elastography. In addition, the forearm and glenohumeral joint rotation range of motion was measured. RESULTS: The SR of the throwing arm was significantly higher in the OCD and medial injury groups than in the control group (both P <.001). In the OCD group, the SR was significantly higher in the throwing arm than in the nonthrowing arm (P <.001), whereas in the medial injury group, there was no significant difference between both arms. The glenohumeral joint external rotation range of motion of the throwing arm was moderately negatively correlated with the SR (r = -0.478, P <.001). CONCLUSIONS: Stiffness of the pronator teres muscle was exhibited only in the throwing arm of individuals with OCD and in both arms in individuals with medial elbow injury. These findings may contribute to an accurate evaluation and prevention of elbow injuries in youth baseball players.

[A CASE OF SUMMER-TYPE HYPERSENSITIVITY PNEUMONITIS ACCOMPANIED BY THE SYNDROME OF INAPPROPRIATE SECRETION OF ANTIDIURETIC HORMONE].

A 47-year old man presented to our hospital with a 6-month history of malaise, cough and dyspnea on exertion. Laboratory testing revealed the severe hyponatremia. A chest X-ray showed bilateral diffuse micronodules. Anti-Trichosporon asahii antibody and environmental provocation test were positive. Bronchoalveolar lavage fluid showed lymphocytosis and low CD4/8 ratio. The specimens obtained by transbronchial lung biopsy revealed alveolitis. Based on these findings, the patient was diagnosed as having summer-type hypersensitivity pneumonitis (SHP). The patient was treated with antigen avoidance and oral corticosteroid. The hyponatremia caused by syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was treated with normal saline and water restriction. Serum sodium level was improved with treatment of SHP, which suggested the relevance between SHP and SIADH.

[FAMILIAL SUMMER-TYPE HYPERSENSITIVITY PNEUMONITIS INDUCED IN SUMMER AND WINTER AT THE WORK PLACE].

We report two family members, a 64-year-old woman (patient 1) and her 37-year-old son (patient 2) diagnosed with summer-type hypersensitivity pneumonitis (SHP). Both patients had high serum titers of anti-Trichosporon asahii antibody. The patients lived in the same house and worked in the same barbershop. Patient 1 was diagnosed with SHP in the summer, and she reacted positively to the provocation test at the work place, but not in the house. Patient 2 was diagnosed with SHP in the winter. Generally, SHP develops and is diagnosed in the summer. The home environment is responsible for most cases of familial SHP. Therefore, our cases of familial SHP are unusual and may suggest that the clinical characteristics of SHP have changed, due to alterations in social and environmental conditions.

Arabidopsis ubiquitin ligase PUB12 interacts with and negatively regulates Chitin Elicitor Receptor Kinase 1 (CERK1).

In Arabidopsis, fungal chitin is recognized as a pathogen-associated molecular pattern (PAMP) by the chitin receptor complex containing the lysin-motif (LysM) receptor-like kinases CERK1 and LYK5. Upon the perception of chitin, CERK1 phosphorylates the receptor-like cytoplasmic kinase, PBL27, which activates the intracellular mitogen-activated protein kinase (MAPK) cascade. However, the mechanisms by which the CERK1-PBL27 complex is regulated remain largely unknown. We identified ubiquitin ligase PUB12 as a component of the PBL27 complex using co-immunoprecipitation and mass spectrometry. However, PUB12 did not interact directly with PBL27. Instead, the ARM domains of PUB12 and its paralog PUB13 interacted with the intracellular domain of CERK1 in a manner that was dependent on its autophosphorylation, suggesting that the phosphorylation-based auto-activation of CERK1 may be required for its interaction with PUB12. The co-expression of PUB12 in Nicotiana benthamiana reduced the accumulation of CERK1. The pub12 pub13 mutant exhibited enhanced chitin-induced immune responses such as ROS production, MAPK activation, and callose deposition. These results suggest that PUB12 and PUB13 are involved in the negative regulation of the chitin receptor complex, which may contribute to the transient desensitization of chitin-induced responses.

Chitin receptor-mediated activation of MAP kinases and ROS production in rice and Arabidopsis.

Rapid induction of plant immune responses is essential to inhibit colonization and invasion by pathogens. Plants can recognize pathogen-associated molecular patterns (PAMPs) including fungal chitin and bacterial flagellin using pattern-recognition receptors (PRRs), which trigger the intracellular activation of mitogen-activated protein kinase (MAPK) cascades and the production of reactive oxygen species (ROS). MAPK activation and ROS production play pivotal roles in the induction of robust immune responses. Recent investigation of chitin- and flagellin-induced immune signaling revealed that receptor-like cytoplasmic kinases (RLCKs) connect PRR-mediated pathogen recognition to MAPK activation and ROS production. In addition, although the MAPK cascade is mediated by 3 sequentially activated protein kinases, MAPK kinase kinase (MAPKKK), MAPK kinase (MAPKK), and MAPK, how MAPKKKs are activated downstream of PRRs in plants has not been identified until recently. In this review, we summarize recent findings of RLCK-mediated MAPK activation and ROS production in rice and Arabidopsis.

Conservation of Chitin-Induced MAPK Signaling Pathways in Rice and Arabidopsis.

Perception of microbe-associated molecular patterns (MAMPs) including chitin by pattern recognition receptors (PRRs) rapidly induces activation of mitogen-activated protein kinase (MAPK) cascades. However, how PRRs transmit immune signals to the MAPK cascade is largely unknown. Recently, Arabidopsis receptor-like cytoplasmic kinase PBL27 has been reported to activate MAPKs through phosphorylation of AtMAPKKK5 in the chitin signaling pathway. In this study, we found that OsRLCK185, a rice ortholog of PBL27, regulates chitin-induced MAPK activation in a similar fashion to PBL27 in rice. Upon chitin perception, OsRLCK185 is phosphorylated by OsCERK1, a component of the chitin receptor complex. OsRLCK185 interacted with OsMAPKKK11 and OsMAPKKK18, rice orthologs of AtMAPKKK5, in yeast two-hybrid assays. Silencing of both OsMAPKKK11 and OsMAPKKK18 significantly reduced chitin-induced activation of OsMPK3 and OsMPK6. Expression levels of OsMAPKKK18 were much higher than that of OsMAPKKK11 in rice cells, which was consistent with the fact that the Osmapkkk11 single mutation did not affect MAPK activation. This result suggested that OsMAPKKK18 plays a more important role than OsMAPKKK11 in the chitin-induced activation of OsMPK3 and OsMPK6. The bimolecular fluorescence complementation (BiFC) experiment indicated that OsRLCK185 interacted with OsMAPKKK18 at the plasma membrane in planta. In vitro phosphorylation experiments showed that OsRLCK185 directly phosphorylates OsMAPKKK18. Furthermore, OsMAPKKK18 interacted with the MAPKK OsMKK4, the upstream component of OsMPK3/6. These results suggested that OsRLCK185 connects the chitin receptor to the MAPK cascade consisting of OsMAPKKK18-OsMKK4-OsMPK3/6. Our data revealed that chitin-induced MAPK activation in rice and Arabidopsis is regulated by common homologous elements.