Niraparib maintenance therapy using an individualised starting dose in patients with platinum-sensitive recurrent ovarian cancer (NORA): final overall survival analysis of a phase 3 randomised, placebo-controlled trial.

Background: Niraparib significantly prolonged progression-free survival versus placebo in patients with platinum-sensitive, recurrent ovarian cancer (PSROC), regardless of germline BRCA mutation (gBRCAm) status, in NORA. This analysis reports final data on overall survival (OS). Methods: This randomised, double-blind, placebo-controlled, phase 3 trial enrolled patients across 30 centres in China between 26 September 2017 and 2 February 2019 (clinicaltrials.gov, NCT03705156). Eligible patients had histologically confirmed, recurrent, (predominantly) high-grade serous epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma (no histological restrictions for those with gBRCAm) and had received ≥2 prior lines of platinum-based chemotherapy. Patients were randomised (2:1) to receive niraparib or placebo, with stratification by gBRCAm status, time to recurrence following penultimate platinum-based chemotherapy, and response to last platinum-based chemotherapy. Following a protocol amendment, the starting dose was individualised: 200 mg/day for patients with bodyweight <77 kg and/or platelet count <150 × 103/µL at baseline and 300 mg/day otherwise. OS was a secondary endpoint. Findings: Totally, 265 patients were randomised to receive niraparib (n = 177) or placebo (n = 88), and 249 (94.0%) received an individualised starting dose. As of 14 August 2023, median follow-up for OS was 57.9 months (IQR, 54.8-61.6). Median OS (95% CI) with niraparib versus placebo was 51.5 (41.4-58.9) versus 47.6 (33.3-not evaluable [NE]) months, with hazard ratio [HR] of 0.86 (95% CI, 0.60-1.23), in the overall population; 56.0 (36.1-NE) versus 47.6 (31.6-NE) months, with HR of 0.86 (95% CI, 0.46-1.58), in patients with gBRCAm; and 46.5 (41.0-NE) versus 46.9 (31.8-NE) months, with HR of 0.87 (95% CI, 0.56-1.35), in those without. No new safety signals were identified, and myelodysplastic syndromes/acute myeloid leukaemia occurred in three (1.7%) niraparib-treated patients. Interpretation: Niraparib maintenance therapy with an individualised starting dose demonstrated a favourable OS trend versus placebo in PSROC patients, regardless of gBRCAm status. Funding: Zai Lab (Shanghai) Co., Ltd; National Major Scientific and Technological Special Project for "Significant New Drugs Development" in 2018, China [grant number 2018ZX09736019].

Assessing the structural and foaming property changes in egg yolk proteins due to malondialdehyde: Experimental and molecular docking studies.

This study evaluated the effects of varying levels of malondialdehyde (MDA) on the structural and foaming properties of the egg yolk proteins (EYPs), and the interaction between them was explored by molecular docking. The results showed that oxidative modification due to MDA increased the carbonyl content of EYPs by 4.49 times. Simultaneously, the total sulfhydryl content was reduced by 21.47%, and the solubility of EYPs was significantly decreased (p < 0.05). Continuous oxidation disorders the previously ordered structure of EYPs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that some proteins underwent crosslinking and aggregation with increased MDA oxidation, aligning with changes in particle size and zeta-potential. Moderate oxidation (<1 mmol/L) enhanced the foaming capacity and foam stability of EYPs. Additionally, molecular docking results uncovered favorable interactions between MDA and specific EYPs, primarily through hydrogen bonding. This research offers valuable insights into managing the functional and quality changes of yolk products during processing.

Effect of Environmental pH on the Mechanics of Chitin and Chitosan: A Single-Molecule Study.

Chitin and chitosan are important structural macromolecules for most fungi and marine crustaceans. The functions and application areas of the two molecules are also adjacent beyond their similar molecular structure, such as tissue engineering and food safety where solution systems are involved. However, the elasticities of chitin and chitosan in solution lack comparison at the molecular level. In this study, the single-molecule elasticities of chitin and chitosan in different solutions are investigated via atomic force microscope (AFM) based single-molecule spectroscopy (SMFS). The results manifest that the two macromolecules share the similar inherent elasticity in DOSM due to their same chain backbone. However, obvious elastic deviations can be observed in aqueous conditions. Especially, a lower pH value (acid environment) is helpful to increase the elasticity of both chitin and chitosan. On the contrary, the tendency of elastic variation of chitin and chitosan in a larger pH value (alkaline environment) shows obvious diversity, which is mainly determined by the side groups. This basic study may produce enlightenment for the design of intelligent chitin and chitosan food packaging and biomedical materials.

A Horizontal and Longitudinal Study on the Changes of Aging Thyroid Function in Elderly Male Population.

OBJECTIVES: There are few follow-up studies on thyroid function in the same group for many years. Therefore, the purpose of this study was to retrospectively analyze the changes of thyroid function in a group of people for 8 years and to explore the changes of thyroid function in elderly men with normal thyroid function with age. METHODS: Reviewing the records of elderly men who underwent physical examination in the Beijing Hospital physical examination center from 2013 to 2020, 354 subjects were included in the study. According to age, they are divided into 4 groups. The differences in thyrotropin (TSH), anti-triiodothyronine (rT3), free triiodothyronine (FT3), and free thyroid hormone (FT4) among different age groups in initial time (2013) were compared. Longitudinal comparison of changes of thyroid function in the same age group for 8 years was compared too. RESULTS: At the initial time, age was negatively correlated with FT3 (r = 0.349, p < 0.001), positively correlated with rT3 and TSH (r = 0.182, p < 0.001, r = 0.212, p < 0.001), but not correlated with FT4. The results of eight years of analysis show that, for TSH, during the whole follow-up period, the TSH of the >80 years group was higher than that of the <60 years and 60-69 years groups, and the difference was statistically significant. The 70-79 age group was higher than the <60 years group at different time points, except for the age group <60 years. The other three groups showed an increasing trend with age, especially in the group of ≥80 years. For FT3, in 2013, the age ≥80 years group was significantly lower than that of the 70-79 years, 60-69 years, and <60 years old groups (p < 0.05). The analysis results at different time points in each age group showed a downward trend and then an upward trend. For FT4, there was no significant difference in FT4 among different age groups in 2013. Still, during the follow-up period, the age group ≥80 was lower than other age groups in 2019 and lower than the <60 years groups in 2014, 2015, 2019, and 2020, and the difference was statistically significant. The change rule of FT4 with the increase of age was not clear. For rT3, during the whole follow-up period, the rT3 of the >80 years group was higher than that of the <60 years and 60-69 years groups, and the difference was statistically significant. The analysis results at different time points in each age group showed a trend of rising first, then falling, and finally rising. After 2017, the rT3 of the 70-79 years and ≥80 years groups increased with age. CONCLUSIONS: The thyroid function index of elderly men changes with age. In transverse analysis, the value of TSH is the highest, and FT3 is the lowest in the group ≥80 years old. There are differences between the changes in the longitudinal analysis and the results of the horizontal analysis. Therefore, the law of thyroid function changing with age in different individuals is not the same as that of the same individual with age, which should be paid more attention in medical research and clinical diagnosis and treatment.

hnRNPU is required for spermatogonial stem cell pool establishment in mice.

The continuous regeneration of spermatogonial stem cells (SSCs) underpins spermatogenesis and lifelong male fertility, but the developmental origins of the SSC pool remain unclear. Here, we document that hnRNPU is essential for establishing the SSC pool. In male mice, conditional loss of hnRNPU in prospermatogonia (ProSG) arrests spermatogenesis and results in sterility. hnRNPU-deficient ProSG fails to differentiate and migrate to the basement membrane to establish SSC pool in infancy. Moreover, hnRNPU deletion leads to the accumulation of ProSG and disrupts the process of T1-ProSG to T2-ProSG transition. Single-cell transcriptional analyses reveal that germ cells are in a mitotically quiescent state and lose their unique identity upon hnRNPU depletion. We further show that hnRNPU could bind to Vrk1, Slx4, and Dazl transcripts that have been identified to suffer aberrant alternative splicing in hnRNPU-deficient testes. These observations offer important insights into SSC pool establishment and may have translational implications for male fertility.

Research on the Surface-State Parameterization of a Refill Friction Stir Spot Welding Joint Made of Aluminum Alloy and Its Connection to the Fracture Mode.

Surface features are crucial for assessing welding quality because they serve as an intuitive depiction of the quality of the joint and have a major influence on welding strength. According to the characteristics of the refill friction stir spot welding (RFSSW) process and an analysis of the surface-state and internal morphology of RFSSW joints, a method of predicting the mechanical properties of RFSSW joints based on surface-state characteristics was proposed. In this paper, a laser-ranging sensor was used to characterize the surface state of RFSSW joints, and parametric characterization methods of the surface-state features of RFSSW joints were proposed. On this basis, a support vector machine was used to predict and analyze the fracture mode of RFSSW joints. The accuracy of the analysis of the test samples reached 95.8%. This paper provides a more efficient and convenient new method for the quality evaluation of RFSSW joints.

Kidney failure secondary to hereditary xanthinuria due to a homozygous deletion of the XDH gene, in the absence of overt kidney stone disease.

Hereditary xanthinuria (HXAN) is a rare metabolic disorder that results from mutations in either the xanthine dehydrogenase (XDH) or the molybdenum cofactor sulfurase genes (MOCOS), respectively defining HXAN type I and type II. Hypouricemia, hypouricosuria, and abnormally high plasma and urine levels of xanthine, causing susceptibility to xanthine nephrolithiasis and deposition of xanthine crystals in tissues, are the metabolic hallmarks of HXAN. Several pathogenic variants in the XDH gene have so far been identified in patients with HXAN type I, but the clinical phenotype associated with the whole deletion of the human XDH gene is unknown. Herein, we report the case of a woman diagnosed with HXAN, whose molecular genetic testing revealed a homozygous microdeletion involving the XDH gene. Distinctive features of her medical history were the diagnosis of arterial hypertension and microalbuminuria at 22 years of age; a single pregnancy, at the age of 25, complicated by proteinuria and transient kidney function deterioration in the third trimester; unexplained severe hypouricaemia incidentally discovered during pregnancy; inability to breastfeed her newborn daughter due to primary agalactia; chronic kidney disease (CKD) stage 3 diagnosed at age 35; and progression to end-stage kidney disease over the next 12 years. Protocol non-invasive laboratory and imaging investigation was not informative as to the cause of CKD. This is the first description of the clinical phenotype associated with a natural knockout of the human XDH gene. Despite the lack of kidney histopathology data, the striking similarities with the phenotypes exhibited by comparable murine models validates the latter as useful sources of mechanistic insights for the pathogenesis of the human disease, supporting the hypothesis that the absence of xanthine dehydrogenase activity might represent a susceptibility factor for chronic tubulointerstitial nephritis, even in patients without kidney stones.

Membrane-associated NRPM proteins are novel suppressors of stomatal production in Arabidopsis.

In Arabidopsis, stomatal development and patterning require tightly regulated cell division and cell-fate differentiation that are controlled by key transcription factors and signaling molecules. To identify new regulators of stomatal development, we assay the transcriptomes of plants bearing enriched stomatal lineage cells that undergo active division. A member of the novel regulators at the plasma membrane (NRPM) family annotated as hydroxyproline-rich glycoproteins was identified to highly express in stomatal lineage cells. Overexpressing each of the four NRPM genes suppressed stomata formation, while the loss-of-function nrpm triple mutants generated severely overproduced stomata and abnormal patterning, mirroring those of the erecta receptor family and MAPKKK yoda null mutants. Manipulation of the subcellular localization of NRPM1 surprisingly revealed its regulatory roles as a peripheral membrane protein instead of a predicted cell wall protein. Further functional characterization suggests that NRPMs function downstream of the EPF1/2 peptide ligands and upstream of the YODA MAPK pathway. Genetic and cell biological analyses reveal that NRPM may promote the localization and function of the ERECTA receptor proteins at the cell surface. Therefore, we identify NRPM as a new class of signaling molecules at the plasma membrane to regulate many aspects of plant growth and development.

VISTA promotes the metabolism and differentiation of myeloid-derived suppressor cells by STAT3 and polyamine-dependent mechanisms.

Myeloid-derived suppressor cells (MDSCs) impair antitumor immune responses. Identifying regulatory circuits during MDSC development may bring new opportunities for therapeutic interventions. We report that the V-domain suppressor of T cell activation (VISTA) functions as a key enabler of MDSC differentiation. VISTA deficiency reduced STAT3 activation and STAT3-dependent production of polyamines, which causally impaired mitochondrial respiration and MDSC expansion. In both mixed bone marrow (BM) chimera mice and myeloid-specific VISTA conditional knockout mice, VISTA deficiency significantly reduced tumor-associated MDSCs but expanded monocyte-derived dendritic cells (DCs) and enhanced T cell-mediated tumor control. Correlated expression of VISTA and arginase-1 (ARG1), a key enzyme supporting polyamine biosynthesis, was observed in multiple human cancer types. In human endometrial cancer, co-expression of VISTA and ARG1 on tumor-associated myeloid cells is associated with poor survival. Taken together, these findings unveil the VISTA/polyamine axis as a central regulator of MDSC differentiation and warrant therapeutically targeting this axis for cancer immunotherapy.

Leveraging CRISPR/Cas12 signal amplifier to sensitive detection of apurinic/apyrimidinic endonuclease 1 and high-throughput inhibitor screening.

As an essential protein in DNA repair, apurinic/apyrimidinic endonuclease 1 (APE1) plays multiple critical functions in maintaining homeostasis, making it a significant biomarker and therapeutic target for many disorders. Here, we describe a simple method to detect APE1 based on the Releasing-Extension-Signal amplification Test (REST) strategy that leverages the dsDNA as the activator to fully unlock the trans-cleavage activity of CRISPR/Cas12a. This assay provides a rapid and specific APE1 detection with a detection limit down to 1.05 × 10-5 U/mL. We also combined this method with an automated pipetting platform and a microplate reader for high-throughput screening of potential inhibitors of APE1. Besides, by changing the modification on the probe, the REST strategy was easily repurposed to detect various DNA glycosylases. Taken together, the simplicity and robustness of the method offer a new choice for APE1 detection and inhibitor screening, showing great potential in practical use. Furthermore, the REST strategy devised in this study provides a new example of applying CRISPR/Cas12a signal amplifier to non-nucleic acid biosensing and inhibitor screening, which broadens the CRISPR-Dx toolbox.

Analysis of the Correlation and Prognostic Significance of Tertiary Lymphoid Structures in Breast Cancer: A Radiomics-Clinical Integration Approach.

BACKGROUND: Tertiary lymphoid structures (TLSs) are potential prognostic indicators. Radiomics may help reduce unnecessary invasive operations. PURPOSE: To analyze the association between TLSs and prognosis, and to establish a nomogram model to evaluate the expression of TLSs in breast cancer (BC) patients. STUDY TYPE: Retrospective. POPULATION: Two hundred forty-two patients with localized primary BC (confirmed by surgery) were divided into BC + TLS group (N = 122) and BC - TLS group (N = 120). FIELD STRENGTH/SEQUENCE: 3.0T; Caipirinha-Dixon-TWIST-volume interpolated breath-hold sequence for dynamic contrast-enhanced (DCE) MRI and inversion-recovery turbo spin echo sequence for T2-weighted imaging (T2WI). ASSESSMENT: Three models for differentiating BC + TLS and BC - TLS were developed: 1) a clinical model, 2) a radiomics signature model, and 3) a combined clinical and radiomics (nomogram) model. The overall survival (OS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) were compared to evaluate the prognostic value of TLSs. STATISTICAL TESTS: LASSO algorithm and ANOVA were used to select highly correlated features. Clinical relevant variables were identified by multivariable logistic regression. Model performance was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC), and through decision curve analysis (DCA). The Kaplan-Meier method was used to calculate the survival rate. RESULTS: The radiomics signature model (training: AUC 0.766; test: AUC 0.749) and the nomogram model (training: AUC 0.820; test: AUC 0.749) showed better validation performance than the clinical model. DCA showed that the nomogram model had a higher net benefit than the other models. The median follow-up time was 52 months. While there was no significant difference in 3-year OS (P = 0.22) between BC + TLS and BC - TLS patients, there were significant differences in 3-year DFS and 3-year DMFS between the two groups. DATA CONCLUSION: The nomogram model performs well in distinguishing the presence or absence of TLS. BC + TLS patients had higher long-term disease control rates and better prognoses than those without TLS. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Efficacy and safety of ripretinib vs. sunitinib in patients with advanced gastrointestinal stromal tumor previously treated with imatinib: A phase 2, multicenter, randomized, open-label study in China.

AIM: A bridging study of INTRIGUE study to assess the efficacy and safety of ripretinib versus sunitinib as second-line treatment in Chinese GIST patients. METHODS: This was a phase 2, multicenter, randomized, open-label study in China. GIST patients previously treated with imatinib were randomized (1:1) to receive ripretinib 150 mg once daily (QD) by continuous dosing in 42-day cycles or sunitinib 50 mg QD in 42-day cycles (four weeks on/two weeks off). Primary endpoint was progression-free survival (PFS) by independent radiological review (IRR). RESULTS: Between 6 December 2020 and 15 September 2021, 108 patients were randomized to receive ripretinib (n = 54) or sunitinib (n = 54) (all-patient [AP] intention-to-treat [ITT] population). Seventy patients had primary KIT exon 11 mutations (ripretinib, n = 35; sunitinib, n = 35; Ex11 ITT population). By data cut-off (20 July 2022), in AP ITT population, PFS by IRR was comparable between ripretinib and sunitinib arms (HR 0·99, 95 % CI 0·57, 1·69; nominal p = 0·92; median PFS [mPFS] 10·3 vs 8·3 months). In Ex11 ITT population, PFS by IRR was longer for ripretinib than sunitinib (HR 0·46, 95 % CI 0·23, 0·92; nominal p = 0·03; mPFS not reached in ripretinib arm and 4·9 months in sunitinib arm). Fewer patients experienced grade 3/4 treatment-related treatment-emergent adverse events with ripretinib (17%) versus sunitinib (56%). CONCLUSIONS: Ripretinib demonstrated similar efficacy and a favorable safety profile versus sunitinib as second-line treatment in Chinese GIST patients. Furthermore, ripretinib provided greater clinically meaningful benefit versus sunitinib in patients with KIT exon 11 mutation.

The genus Balanophora J. R. Forst. & G. Forst. - Its use in traditional medicine, phytochemistry, and pharmacology: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Natural products, particularly medicinal plants, have been utilized in traditional medicine for millennia to treat various diseases. The genus Balanophora (Balanophoraceae) consists of 23 accepted species. These species are the most controversial flowering plants, with highly reduced morphologies and are found parasitizing on the roots of their host. They have been used in traditional medicine as a remedy for stomach pain, detumescence, uterine prolapse, wounds, syphilis, gonorrhea, treating injuries from falls, and other conditions. However, there is no review of this genus on its traditional uses, phytochemistry, and pharmacology. AIM: The present narrative review discusses the scientific data supporting the traditional uses of Balanophora species. The available information on its botanical properties, traditional uses, chemical contents, pharmacological activities, and toxicity was summarized to help comprehend current research and offer a foundation for future research. MATERIALS AND METHODS: The materials used in combining data on the genus Balanophora comprises online sources such as Web of Science, Google Scholar, Science Direct, and Chinese National Knowledge Infrastructure (CNKI) for Chinese-related materials. World Flora online was used in validating the scientific names of this genus while ChemBio Draw Ultra Version 22.2 software was employed in drawing the phytochemical compounds. RESULTS: Nine Balanophora species including B. harlandii, B. japonica, B. polyandra, B. fungosa, B. fungosa subsp. indica, B. laxiflora, B. abbreviata, B. tobiracola, and B. involucrata have been documented as vital sources of traditional medicines in different parts of Asia. A total of 159 secondary metabolites have been isolated and identified from the ten species of this genus comprising tannins, flavonoids, sterols, lignans, chalcones, terpenes, and phenylpropanoids. Among these compounds, tannins, lignans, terpenoids, chalcones and phenolic acids contribute to the pharmacological activities of the species in this genus with several biological activities both in vitro and in vivo such as anti-inflammatory, anti-oxidant, hypoglycemic activity, cytotoxicity, anti-microbial, melanin synthesis etc. CONCLUSION: This review summarizes the available literature on the traditional uses, pharmacological properties, and phytoconstituents of Balanophora species indicating that they contain fascinating chemical compounds with diverse biological activities. The traditional uses of the species in this genus have been confirmed by scientific data such as antimicrobial, hemostatic effect, gastroprotective activity and others. However, many species in this genus are yet unknown in terms of their botanical uses, chemical composition and biological activities. Thus, more research into the scientific connections between traditional medicinal uses and pharmacological activities, mode of action of the isolated bioactive constituents, and toxicity of other Balanophora species is needed to determine their efficacy and therapeutic potential for safe clinical application.

Nanotechnological approaches for the treatment of placental dysfunction: recent trends and future perspectives.

The transitory placenta develops during pregnancy and mediates the blood flow between the mother and the developing baby. Placental dysfunction, including but not limited to placenta accreta spectrum, fetal growth restriction, preeclampsia and gestational trophoblastic disease, arises from abnormal placental development and can result in significant adverse maternal and fetal health outcomes. Unfortunately, there is a lack of treatment alternatives for these disorders. Nanocarriers offer versatility, including extended circulation, organ-specific targeting and intracellular transport, finely tuning therapeutic placental interactions. This thorough review explores nanotechnological strategies for addressing placental disorders, encompassing dysfunction insights, potential drug-delivery targets and recent strides in placenta-targeted nanoparticle (NP) therapies, instilling hope for effective placental malfunction treatment.

The placenta, essential for mother­baby blood exchange, may experience catastrophic abnormalities during pregnancy. Treating these issues is challenging since you must focus on the placenta while protecting the infant. Nanotechnology might be helpful in this scenario. Nanocarriers are small carriers that can transport medications to the placenta and other particular locations in the body. They can aid in the treatment of various placental issues. In our present review, we discuss nanotechnology's solutions to these issues. We discuss what goes wrong, potential therapeutic applications for nanocarriers and recent developments in their use. This might be a novel approach to treating placenta issues and maintaining the health of mothers and infants.

Coding RNA expression profile and transcription factor analysis of H.pylori-associated chronic atrophic gastritis.

PURPOSE: Atrophic gastritis, one of the processes leading to gastric cancer (GC), is closely related to Helicobacter pylori (HP) infection. This study aimed to understand how HP causes chronic inflammation that leads to ulcers and stomach problems. METHODS: Twenty-eight CAG patients were included in the study (9 HP-infected and 19 HP-uninfected). Endoscopy, histopathology, and high-throughput mRNA sequencing were performed. Differentially expressed genes (DEGs) were validated via qRT-PCR. RESULTS: Principal component analysis (PCA) results showed that more than 88.9 â€‹% of the samples were classified into the HP (+) group. A total of 157 DEGs were identified, of which 38 were up-regulated and 119 were down-regulated. The DEGs were mainly enriched in the biological process (BP) terms associated with immune system process, adaptive immune response, G protein-coupled receptor signaling pathway, as well as point to numerous key pathways, including fat digestion and absorption, retinol metabolism, steroid hormone biosynthesis, ascorbate and aldarate metabolism, and chemical carcinogenesis. APOA1, APOA4, FOXP3, NR1H4, ABCG5, ACTA1, CCL19, CCR7, CYP3A4, and PDCD had the highest degrees in protein-protein interaction network as the hub genes; they were also included into the transcription factor (TF)-target network except for PDCD. APOA1 and CYP3A4 were extremely significantly up-regulated in HP (+) CAG patients compared with the HP (-) CAG patients, while FOXP3, CCR7 and CCL19 were significantly down-regulated. CONCLUSION: The expression of APOA1, CYP3A4, FOXP3, CCR7, and CCL19 are the potential indicators for CAG to GC development, being the biomarkers to predict progression of CAG and poor prognosis of GC.

Antagonistic RALF peptides control an intergeneric hybridization barrier on Brassicaceae stigmas.

Pollen-pistil interactions establish interspecific/intergeneric pre-zygotic hybridization barriers in plants. The rejection of undesired pollen at the stigma is crucial to avoid outcrossing but can be overcome with the support of mentor pollen. The mechanisms underlying this hybridization barrier are largely unknown. Here, in Arabidopsis, we demonstrate that receptor-like kinases FERONIA/CURVY1/ANJEA/HERCULES RECEPTOR KINASE 1 and cell wall proteins LRX3/4/5 interact on papilla cell surfaces with autocrine stigmatic RALF1/22/23/33 peptide ligands (sRALFs) to establish a lock that blocks the penetration of undesired pollen tubes. Compatible pollen-derived RALF10/11/12/13/25/26/30 peptides (pRALFs) act as a key, outcompeting sRALFs and enabling pollen tube penetration. By treating Arabidopsis stigmas with synthetic pRALFs, we unlock the barrier, facilitating pollen tube penetration from distantly related Brassicaceae species and resulting in interspecific/intergeneric hybrid embryo formation. Therefore, we uncover a "lock-and-key" system governing the hybridization breadth of interspecific/intergeneric crosses in Brassicaceae. Manipulating this system holds promise for facilitating broad hybridization in crops.

Molecular characterization and functional analysis of a mollusk Rel homologous gene.

Members of the nuclear factor-kappa B (NF-κB) family are crucial regulators of physiological processes such as apoptosis, inflammation, and the immune response, acting as vital transcription factors to perform their function. In this study, we identified a NF-κB homologous gene (CfRel1) in Zhikong scallops. The 3006-bp-long open reading frame encodes 1001 amino acids. The N-terminus of the CfRel1 protein harbors a conserved Rel homology domain (RHD) that contains a DNA-binding domain and a dimerization domain. According to the multiple sequence alignment results, both the DNA-binding and dimerization domains are highly conserved. Phylogenetic analysis indicated that CfRel1 is closely related to both the Dorsal protein of Pinctada fucata and the Rel2 protein of Crassostrea gigas. CfRel1 mRNA was expressed in all tissues tested in the quantitative reverse transcription PCR experiments, with hepatopancreatic tissue expressing the highest levels. Furthermore, after stimulation with lipopolysaccharide, peptidoglycan, or polyinosinic:polycytidylic acid, the mRNA expression level of CfRel1 was markedly increased. The co-immunoprecipitation test results showed that CfRel1 interacted with scallop IκB protein through its RHD DNA-binding domain, suggesting that IκB may regulate the activity of Rel1 by binding to this domain. Dual-luciferase reporter gene assays revealed that CfRel1 overexpression in HEK293T cells activated the activator protein 1 (AP-1), NF-κB, interferon (IFN)α, IFNß, and IFNγ reporter genes, indicating the diverse functions of the protein. In summary, CfRel1 is capable of responding to attacks from pathogen-associated molecular patterns, participating in immune signaling, and activating NF-κB and IFN reporter genes. Our findings contribute to the advancement of invertebrate innate immunity theory, enrich the theory of comparative immunology, and serve as a reference for the future screening of disease-resistant strains in scallops.

Revealing the Control Mechanisms of pH on the Solution Properties of Chitin via Single-Molecule Studies.

Chitin is one of the most common polysaccharides and is abundant in the cell walls of fungi and the shells of insects and aquatic organisms as a skeleton. The mechanism of how chitin responds to pH is essential to the precise control of brewing and the design of smart chitin materials. However, this molecular mechanism remains a mystery. Results from single-molecule studies, including single-molecule force spectroscopy (SMFS), AFM imaging, and molecular dynamic (MD) simulations, have shown that the mechanical and conformational behaviors of chitin molecules show surprising pH responsiveness. This can be compared with how, in natural aqueous solutions, chitin tends to form a more relaxed spreading conformation and show considerable elasticity under low stretching forces in acidic conditions. However, its molecular chain collapses into a rigid globule in alkaline solutions. The results show that the chain state of chitin can be regulated by the proportions of inter- and intramolecular H-bonds, which are determined via the number of water bridges on the chain under different pH values. This basic study may be helpful for understanding the cellular activities of fungi under pH stress and the design of chitin-based drug carriers.

Amyloplast sedimentation repolarizes LAZYs to achieve gravity sensing in plants.

Gravity controls directional growth of plants, and the classical starch-statolith hypothesis proposed more than a century ago postulates that amyloplast sedimentation in specialized cells initiates gravity sensing, but the molecular mechanism remains uncharacterized. The LAZY proteins are known as key regulators of gravitropism, and lazy mutants show striking gravitropic defects. Here, we report that gravistimulation by reorientation triggers mitogen-activated protein kinase (MAPK) signaling-mediated phosphorylation of Arabidopsis LAZY proteins basally polarized in root columella cells. Phosphorylation of LAZY increases its interaction with several translocons at the outer envelope membrane of chloroplasts (TOC) proteins on the surface of amyloplasts, facilitating enrichment of LAZY proteins on amyloplasts. Amyloplast sedimentation subsequently guides LAZY to relocate to the new lower side of the plasma membrane in columella cells, where LAZY induces asymmetrical auxin distribution and root differential growth. Together, this study provides a molecular interpretation for the starch-statolith hypothesis: the organelle-movement-triggered molecular polarity formation.