FERONIA: A Receptor Kinase at the Core of a Global Signaling Network.

Initially identified as a key regulator of female fertility in Arabidopsis, the FERONIA (FER) receptor kinase is now recognized as crucial for almost all aspects of plant growth and survival. FER partners with a glycosylphosphatidylinositol-anchored protein of the LLG family to act as coreceptors on the cell surface. The FER-LLG coreceptor interacts with different RAPID ALKALINIZATION FACTOR (RALF) peptide ligands to function in various growth and developmental processes and to respond to challenges from the environment. The RALF-FER-LLG signaling modules interact with molecules in the cell wall, cell membrane, cytoplasm, and nucleus and mediate an interwoven signaling network. Multiple FER-LLG modules, each anchored by FER or a FER-related receptor kinase, have been studied, illustrating the functional diversity and the mechanistic complexity of the FER family signaling modules. The challenges going forward are to distill from this complexity the unifying schemes where possible and attain precision and refinement in the knowledge of critical details upon which future investigations can be built. By focusing on the extensively characterized FER, this review provides foundational information to guide the next phase of research on FER in model as well as crop species and potential applications for improving plant growth and resilience.

Extracellular pectin-RALF phase separation mediates FERONIA global signaling function.

The FERONIA (FER)-LLG1 co-receptor and its peptide ligand RALF regulate myriad processes for plant growth and survival. Focusing on signal-induced cell surface responses, we discovered that intrinsically disordered RALF triggers clustering and endocytosis of its cognate receptors and FER- and LLG1-dependent endocytosis of non-cognate regulators of diverse processes, thus capable of broadly impacting downstream responses. RALF, however, remains extracellular. We demonstrate that RALF binds the cell wall polysaccharide pectin. They phase separate and recruit FER and LLG1 into pectin-RALF-FER-LLG1 condensates to initiate RALF-triggered cell surface responses. We show further that two frequently encountered environmental challenges, elevated salt and temperature, trigger RALF-pectin phase separation, promiscuous receptor clustering and massive endocytosis, and that this process is crucial for recovery from stress-induced growth attenuation. Our results support that RALF-pectin phase separation mediates an exoskeletal mechanism to broadly activate FER-LLG1-dependent cell surface responses to mediate the global role of FER in plant growth and survival.

Brassinosteroid recruits FERONIA to safeguard cell expansion in Arabidopsis.

Plant cell expansion is driven by turgor pressure and regulated by hormones. How plant cells avoid cell wall rupture during hormone-induced cell expansion remains a mystery. Here we show that brassinosteroid (BR), while stimulating cell elongation, promotes the plasma membrane (PM) accumulation of the receptor kinase FERONIA (FER), which monitors cell wall damage and in turn attenuates BR-induced cell elongation to prevent cell rupture. The GSK3-like kinase BIN2 phosphorylates FER, resulting in reduced FER accumulation and translocation from endoplasmic reticulum to PM. By inactivating BIN2, BR signaling promotes dephosphorylation and increases PM accumulation of FER, thereby enhancing the surveillance of cell wall integrity. Our study reveals a vital signaling circuit that coordinates hormone signaling with mechanical sensing to prevent cell bursting during hormone-induced cell expansion.

Efficacy, safety, and correlative biomarkers of bintrafusp alfa in recurrent or metastatic nasopharyngeal cancer patients: a phase II clinical trial.

Background: The strategy of dual blockade of TGF-ß and PD-L1 pathways has not been previously tested in platinum-refractory recurrent or metastatic nasopharyngeal cancer (R/M NPC) patients. This study aimed to evaluate the safety and efficacy of bintrafusp alfa in refractory R/M NPC patients. Methods: In this single-arm, single-centre phase II clinical trial, 38 histologically confirmed R/M NPC patients were enrolled and administered with bintrafusp alfa every 2 weeks. Primary endpoint was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). Secondary endpoints included progression-free survival (PFS), overall survival (OS), duration of response (DOR), and safety. Findings: Thirty-eight patients were accrued (33 men; median age, 54 years). ORR was 23.7% (complete response, n = 2; partial response, n = 7). The median DOR was 19.2 months, median PFS was 2.3 months, median OS was 17.0 months, and 1-year OS rate was 63.2%. Unfortunately, 25 patients (65.7%) progressed within 8 weeks of treatment, 15 patients (39.5%) and 8 patients (21.1%) developed hyper-progressive disease (HPD) per RECIST v1.1 and tumor growth rate (TGR) ratio respectively. Sixteen patients (42.4%) experienced ≥ grade 3 treatment-related adverse events (TRAEs), most commonly anemia (n = 9, 23.7%) and secondary malignancies (n = 4, 10.5%). TRAEs led to permanent treatment discontinuation in 7 patients. Patients with strong suppression of plasma TGFß1 level at week 8 were unexpectedly associated with worse ORR (9.1% vs 44.4%, P = 0.046) and development of HPD. There was no correlation between PD-L1 expression and ORR. Interpretation: Bintrafusp alfa demonstrated modest activity in R/M NPC but high rates of HPD and treatment discontinuation secondary to TRAEs are concerning. Funding: The project was supported by Alice Ho Miu Ling Nethersole Charity Foundation Professorship Endowed Fund and Merck KGaA.

Cord blood-derived Vδ2+ and Vδ2- T cells acquire differential cell state compositions upon in vitro expansion.

Human cord blood-derived γδ T cells (CBγδ) display a highly diverse TCRγδ repertoire and have a unique subtype composition different from fetal or adult peripheral blood counterparts. We expanded CBγδ in vitro using an irradiated Epstein-Barr virus-transformed feeder cell-based modified rapid expansion protocol (REP). Single-cell RNA sequencing tracked progressive differentiation of naïve CBγδ into cells expressing neoantigen-reactive tumor-infiltrating lymphocyte as well as tissue-resident memory precursor-like and antigen-presenting cell-like gene signatures. TCRγδ clonal tracing revealed a bias toward cytotoxic effector differentiation in a much larger proportion of Vδ2- clones compared to Vδ2+ clones, resulting in the former being more cytotoxic at the population level. These clonotype-specific differentiation dynamics were not restricted to REP and were recapitulated upon secondary nonviral antigen stimulations. Thus, our data showed intrinsic cellular differences between major subtypes of human γδ T cells already in operation at early postnatal stage and highlighted key areas of consideration in optimizing cell manufacturing processes.

Using Hyper as a molecular probe to visualize hydrogen peroxide in living plant cells: An updated method.

Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules that play a myriad of roles in animal and plant cells. In plant cells the production of ROS results from aerobic metabolism during respiration and photosynthesis. Therefore mitochondria, chloroplasts, and peroxisomes constitute an important source of ROS. However, ROS can also be produced in response to many physiological stimuli such as pathogen attack, hormone signaling, abiotic stresses or during cell wall organization and plant morphogenesis. The study of ROS in plant cells has been limited to biochemical assays and use of fluorescent probes, however, the irreversible oxidation of the fluorescent dyes prevents the visualization of dynamic changes. We have previously reported that Hyper 1 is a biosensor for H2O2 and consists of a circularly permutated YFP (cpYFP) inserted into the regulatory domain of the Escherichia coli hydrogen peroxide (H2O2) sensor protein OxyR rendering it an H2O2-specific quantitative probe (Bilan & Belousov, 2018; Hernandez-Barrera et al., 2015). Herein we describe an updated protocol for using the improved new version of Hyper 2 and Hyper 3 as a dynamic biosensor for H2O2 in Arabidopsis with virtually unlimited potential to detect H2O2 throughout the plant and under a broad range of developmental and environmental conditions (Bilan et al., 2013).

The effect of a lifestyle intervention program using a mobile application versus the effect of a program using a booklet for adults with metabolic syndrome: A three-arm randomized controlled trial.

PURPOSE: The research aimed to examine the effect of a lifestyle intervention program using mobile application versus booklet for adults with metabolic syndrome in Hong Kong. The outcomes comprised body weight (primary outcome), exercise amount, improvement of cardiometabolic risk factors, cardiovascular endurance, perceived stress scale, and exercise self-efficacy. DESIGN: A three-arm randomized controlled trial namely App group, Booklet group, and control group was adopted. METHODS: Two hundred sixty-four adults with metabolic syndrome were recruited from community centers from 2019 to December 2021. Inclusion criteria are those adults with metabolic syndrome, able to use a smart phone. All participants received a 30-min health talk. App group additionally received a mobile application, while Booklet group received a booklet, and the control group received a placebo booklet. Data were collected at baseline, Weeks 4, 12, and 24. SPSS and generalized estimating equations (GEE) model were employed for data analysis. FINDINGS: Attrition rates were minimal, ranged from 2.65% to 6.44%. Both app and booklet group showed significant improvement in outcomes (exercise amount, waist circumference) when compared to control group. However, statistically significant and superior results were observed in app group, including body weight, exercise amount, waist circumference, body mass index, and systolic blood pressure when compared to booklet group. CONCLUSION: The lifestyle intervention supported with app was found to be superior to the booklet support for reducing body weight and maintaining exercise. CLINICAL RELEVANCE: The lifestyle intervention program using mobile application support could be used widely for adults with metabolic syndrome in the community. Suggest nurses may incorporate this program in their health promotion strategies focusing on a healthy lifestyle to reduce the risk of progression to metabolic syndrome.

A single-cell atlas identifies pretreatment features of primary imatinib resistance in chronic myeloid leukemia.

Primary resistance to tyrosine kinase inhibitors (TKIs) is a significant barrier to optimal outcomes in chronic myeloid leukemia (CML), but factors contributing to response heterogeneity remain unclear. Using single-cell RNA (scRNA) sequencing, we identified 8 statistically significant features in pretreatment bone marrow, which correlated with either sensitivity (major molecular response or MMR) or extreme resistance to imatinib (eventual blast crisis [BC] transformation). Employing machine-learning, we identified leukemic stem cell (LSC) and natural killer (NK) cell gene expression profiles predicting imatinib response with >80% accuracy, including no false positives for predicting BC. A canonical erythroid-specifying (TAL1/KLF1/GATA1) regulon was a hallmark of LSCs from patients with MMR and was associated with erythroid progenitor [ERP] expansion in vivo (P < .05), and a 2- to 10-fold (6.3-fold in group A vs 1.09-fold in group C) erythroid over myeloid bias in vitro. Notably, ERPs demonstrated exquisite TKI sensitivity compared with myeloid progenitors (P < .001). These LSC features were lost with progressive resistance, and MYC- and IRF1-driven inflammatory regulons were evident in patients who progressed to transformation. Patients with MMR also exhibited a 56-fold expansion (P < .01) of a normally rare subset of hyperfunctional adaptive-like NK cells, which diminished with progressive resistance, whereas patients destined for BC accumulated inhibitory NKG2A+ NK cells favoring NK cell tolerance. Finally, we developed antibody panels to validate our scRNA-seq findings. These panels may be useful for prospective studies of primary resistance, and in assessing the contribution of predetermined vs acquired factors in TKI response heterogeneity.

Stigma receptors control intraspecies and interspecies barriers in Brassicaceae.

Flowering plants have evolved numerous intraspecific and interspecific prezygotic reproductive barriers to prevent production of unfavourable offspring1. Within a species, self-incompatibility (SI) is a widely utilized mechanism that rejects self-pollen2,3 to avoid inbreeding depression. Interspecific barriers restrain breeding between species and often follow the SI × self-compatible (SC) rule, that is, interspecific pollen is unilaterally incompatible (UI) on SI pistils but unilaterally compatible (UC) on SC pistils1,4-6. The molecular mechanisms underlying SI, UI, SC and UC and their interconnections in the Brassicaceae remain unclear. Here we demonstrate that the SI pollen determinant S-locus cysteine-rich protein/S-locus protein 11 (SCR/SP11)2,3 or a signal from UI pollen binds to the SI female determinant S-locus receptor kinase (SRK)2,3, recruits FERONIA (FER)7-9 and activates FER-mediated reactive oxygen species production in SI stigmas10,11 to reject incompatible pollen. For compatible responses, diverged pollen coat protein B-class12-14 from SC and UC pollen differentially trigger nitric oxide, nitrosate FER to suppress reactive oxygen species in SC stigmas to facilitate pollen growth in an intraspecies-preferential manner, maintaining species integrity. Our results show that SRK and FER integrate mechanisms underlying intraspecific and interspecific barriers and offer paths to achieve distant breeding in Brassicaceae crops.

The RAC/ROP GTPase activator OsRopGEF10 functions in crown root development by regulating cytokinin signaling in rice.

RAC/Rho of plant (ROP) GTPases are major molecular switches that control diverse signaling cascades for plant growth, development, and defense. Here, we discovered a signaling node that connects RAC/ROPs to cytokinins. Rice (Oryza sativa) plants develop a fibrous root system mainly composed of crown roots. Cytokinin signaling via a phosphorelay system is critical for crown root development. We show that OsRopGEF10, which activates RAC/ROPs, acts upstream of the cytoplasmic-nuclear shuttling phosphotransfer proteins AHPs of the cytokinin signaling pathway to promote crown root development. Mutations of OsRopGEF10 induced hypersensitivity to cytokinin, whereas overexpressing this gene reduced the cytokinin response. Loss of OsRopGEF10 function reduced the expression of the response regulator gene OsRR6, a repressor of cytokinin signaling, and impaired crown root development. Mutations in OsAHP1/2 led to increased crown root production and rescued the crown root defect of Osropgef10. Furthermore, auxin activates the ROP GTPase OsRAC3, which attenuates cytokinin signaling for crown root initiation. Molecular interactions between OsRopGEF10, OsRAC3, and OsAHP1/2 implicate a mechanism whereby OsRopGEF10-activated OsRAC3 recruits OsAHP1/2 to the cortical cytoplasm, sequestering them from their phosphorelay function in the nucleus. Together, our findings uncover the OsRopGEF10-OsRAC3-OsAHP1/2 signaling module, establish a link between RAC/ROPs and cytokinin, and reveal molecular crosstalk between auxin and cytokinin during crown root development.

Dampened Inflammation and Improved Survival After CXCL5 Administration in Murine Lupus via Myeloid and Neutrophil Pathways.

OBJECTIVE: To determine the efficacy of CXCL5 administration in lupus-prone MRL/lpr (Faslpr ) mice and elucidate its working mechanisms. METHODS: CXCL5 expression in blood (obtained from SLE patients and Faslpr mice) and major internal organs (obtained from Faslpr mice) was examined by Luminex, real-time polymerase chain reaction, and immunofluorescent staining analyses. Pharmacokinetic studies were performed in Faslpr mice and healthy Institute of Cancer Research mice. Efficacy of CXCL5 administration was demonstrated in Faslpr mice, and the working mechanism of CXCL5 treatment was elucidated by flow cytometry, Luminex, and RNA sequencing. RESULTS: In SLE patients, serum CXCL5 levels were significantly lower than in healthy individuals (P < 0.0001) and negatively correlated with disease activity (P = 0.004). In Faslpr mice, disease severity progressed with age and was negatively associated with plasma CXCL5 levels. Intravenous administration of CXCL5 to Faslpr mice restored endogenous circulatory CXCL5, improved mice survival, and reduced anti-double-stranded DNA antibodies, proteinuria, lupus nephritis activity and chronicity indices, renal complements, and neutrophil extracellular traps over short-term (10 weeks) and long-term (2 years) time periods. In vitro and in vivo assays demonstrated that CXCL5 dictated neutrophil trafficking and suppressed neutrophil activation, degranulation, proliferation, and renal infiltration. Renal and splenic RNA sequencing further showed that CXCL5-mediated immunomodulation occurred by promoting energy production in renal-infiltrated immune cells, activating certain T cells, and reducing tissue fibrosis, granulocyte extravasation, complement components, and interferons. Further factorial design results indicated that CXCL5 appears to enhance host tolerability to cyclophosphamide in vulnerable individuals. CONCLUSION: We found that serum CXCL5 levels were significantly lower in SLE patients than in healthy individuals and were negatively correlated with disease activity. By administering CXCL5 intravenously in a mouse model of lupus, mouse survival improved, and indices of disease activity reduced significantly. Taken together, these findings indicate CXCL5 administration may represent a novel myeloid/neutrophil-targeting therapy for SLE.

Impacts of Educational Interventions with Support of Mobile App versus Booklet for Patients with Hypertension and Metabolic Syndrome: A Secondary Data Analysis.

BACKGROUND: Hypertension comorbid with metabolic syndrome could increase the development of adverse cardiovascular events. Educational interventions were effective to improve outcomes in patients. METHODS: This was a secondary data analysis of participants with hypertension. The original randomized controlled trial aimed to examine the effect of app and booklet versus control among individuals diagnosed with metabolic syndrome living in the community. A 30-min health education was provided to each participant. In addition to the education, the app group received a mobile app while the booklet group received a booklet. Data were collected at baseline, week 4, week 12, and week 24. Intention-to-treat principle was followed, and generalized estimating equations was employed for data analysis. RESULTS: A total of 118 participants with hypertension and metabolic syndrome were extracted from the three-arm trial data. The sample size was 36, 42, and 40 in the app group, booklet group, and control group, respectively. Compared to the control group, the app group showed a significant reduction on body weight and waist circumference at week 24, while the total exercise and self-efficacy for exercise were increased at week 12 and week 24 but no significant findings were observed in the booklet group. CONCLUSIONS: The educational intervention supported with app was superior to the booklet support on the outcomes of body weight, waist circumference, total exercise, and self-efficacy for exercise among patients with hypertension and metabolic syndrome in the community.

Implementation of evidence on management of pleural diseases: insights from a territory-wide survey of clinicians in Hong Kong.

BACKGROUND: Major advances in management of common pleural diseases have taken place in the past decade. However, pleural diseases are often managed by physicians of diverse training background and research on implementation of new knowledge is scanty. We aim to evaluate the practice pattern in pleural medicine among physicians in Hong Kong, for identification of possible gaps for clinical service improvement. METHODS: The Hong Kong Thoracic Society undertook a cross-sectional questionnaire survey in 2019, targeting clinicians of various subspecialties in internal medicine and levels of experience (basic and higher trainees, specialists) from twelve regional hospitals of diverse service scopes throughout Hong Kong. Respondents were selected by non-probability quota sampling. The questionnaire tool consisted of 46 questions covering diagnostic and therapeutic aspects of common pleural diseases. The responses were anonymous, and analysed independently using SPSS statistics software. RESULTS: The survey collected 129 responses, 47(36%) were from clinicians specialized in respiratory medicine. Majority of the respondents (98%) managed pleural diseases, including performing pleural procedures in their practice. Fifty-five percent of all the respondents had not received any formal training in transthoracic ultrasonography. A significant proportion of clinicians were unaware of pleuroscopy for investigation of exudative pleural effusion, indwelling pleural catheter for recurrent malignant pleural effusion, and combined intra-pleural Alteplase plus DNase for treatment of pleural infection (30%, 15% and 70% of non-respiratory clinicians respectively). Significant heterogeneity was found in the management of pleural infection, malignant pleural effusion and pneumothorax among respiratory versus non-respiratory clinicians. Contributing factors to the observed heterogeneity included lack of awareness or training, limited accessibility of drugs, devices, or dedicated service support. CONCLUSION: Significant heterogeneity in management of pleural diseases was observed among medical clinicians in Hong Kong. Continuous medical education and training provision for both specialists and non-specialists has to be strengthened to enhance the implementation of advances, improve quality and equity of healthcare provision in pleural medicine.

Evolutionary analysis of the LORELEI gene family in plants reveals regulatory subfunctionalization.

A signaling complex comprising members of the LORELEI (LRE)-LIKE GPI-anchored protein (LLG) and Catharanthus roseus RECEPTOR-LIKE KINASE 1-LIKE (CrRLK1L) families perceive RAPID ALKALINIZATION FACTOR (RALF) peptides and regulate growth, reproduction, immunity, and stress responses in Arabidopsis (Arabidopsis thaliana). Genes encoding these proteins are members of multigene families in most angiosperms and could generate thousands of signaling complex variants. However, the links between expansion of these gene families and the functional diversification of this critical signaling complex as well as the evolutionary factors underlying the maintenance of gene duplicates remain unknown. Here, we investigated LLG gene family evolution by sampling land plant genomes and explored the function and expression of angiosperm LLGs. We found that LLG diversity within major land plant lineages is primarily due to lineage-specific duplication events, and that these duplications occurred both early in the history of these lineages and more recently. Our complementation and expression analyses showed that expression divergence (i.e. regulatory subfunctionalization), rather than functional divergence, explains the retention of LLG paralogs. Interestingly, all but one monocot and all eudicot species examined had an LLG copy with preferential expression in male reproductive tissues, while the other duplicate copies showed highest levels of expression in female or vegetative tissues. The single LLG copy in Amborella trichopoda is expressed vastly higher in male compared to in female reproductive or vegetative tissues. We propose that expression divergence plays an important role in retention of LLG duplicates in angiosperms.

Pollen-pistil interactions: It takes two to tangle but a molecular cast of many to deliver.

Explosive advances have been made in the molecular understanding of pollen-pistil interactions that underlie reproductive success in flowering plants in the past three decades. Among the most notable is the discovery of pollen tube attractants [1∗,2∗]. The roles these molecules play in facilitating conspecific precedence thus promoting interspecific genetic isolation are also emerging [3-5]. Male-female interactions during the prezygotic phase and contributions from the male and female gametophytes have been comprehensively reviewed recently. Here, we focus on key advances in understanding the mechanistic underpinnings of how these interactions overcome barriers at various pollen-pistil interfaces along the pollen tube growth pathway to facilitate fertilization by desirable mates.