Development of new dehydrocostuslactone derivatives for treatment of atopic dermatitis via inhibition of the NF-κB signaling pathway.

Atopic dermatitis (AD), a recurrent inflammatory systemic skin disease, is difficult to cure. In the present study, several ethylenediamine-derived dehydrocostuslactone (DHCL) derivatives were prepared to assess their in vitro and in vivo anti-inflammatory activities. The results indicated that DHCL derivatives inhibited NO generation with low cytotoxicity. In particular, compound 5d exhibited the best anti-inflammatory activity. Subsequent experiments revealed that 5d not only inhibited the LPS-induced inflammatory response in RAW264.7 cells via the MAPK-NF-κB signaling pathway inhibition but also significantly decreased Th2-type cytokine levels and inhibited the NF-κB signaling pathway activation in mice with MC903-induced AD. Therefore, DHCL derivatives may be considered as new agents for the treatment of AD.

Association of Wearable Device-Measured Step Volume and Variability With Blood Pressure in Older Chinese Adults: Mobile-Based Longitudinal Observational Study.

BACKGROUND: The paucity of evidence on longitudinal and consecutive recordings of physical activity (PA) and blood pressure (BP) under real-life conditions and their relationships is a vital research gap that needs to be addressed. OBJECTIVE: This study aims to (1) investigate the short-term relationship between device-measured step volume and BP; (2) explore the joint effects of step volume and variability on BP; and (3) examine whether the association patterns between PA and BP varied across sex, hypertension status, and chronic condition status. METHODS: This study used PA data of a prospective cohort of 3070 community-dwelling older adults derived from a mobile health app. Daily step counts, as a proxy of step volume, were derived from wearable devices between 2018 and 2022 and categorized into tertiles (low, medium, and high). Step variability was assessed using the SD of daily step counts. Consecutive daily step count recordings within 0 to 6 days preceding each BP measurement were analyzed. Generalized estimation equation models were used to estimate the individual and joint associations of daily step volume and variability with BP. Stratified analyses by sex, the presence of hypertension, and the number of morbidities were further conducted. RESULTS: A total of 3070 participants, with a median age of 72 (IQR 67-77) years and 71.37% (2191/3070) women, were included. Participants walked a median of 7580 (IQR 4972-10,653) steps and 5523 (IQR 3590-7820) meters per day for a total of 592,597 person-days of PA monitoring. Our results showed that higher levels of daily step volume were associated with lower BP (systolic BP, diastolic BP, mean arterial pressure, and pulse pressure). Compared with participants with low step volume (daily step counts <6000/d) and irregular steps, participants with high step volume (≥9500/d) and regular steps showed the strongest decrease in systolic BP (-1.69 mm Hg, 95% CI -2.2 to -1.18), while participants with medium step volume (6000/d to <9500/d) and regular steps were associated with the lowest diastolic BP (-1.067 mm Hg, 95% CI -1.379 to -0.755). Subgroup analyses indicated generally greater effects on women, individuals with normal BP, and those with only 1 chronic disease, but the effect pattern was varied and heterogeneous between participants with different characteristics. CONCLUSIONS: Increased step volume demonstrated a substantial protective effect on BP among older adults with chronic conditions. Furthermore, the beneficial association between step volume and BP was enhanced by regular steps, suggesting potential synergistic protective effects of both increased step volume and step regularity. Targeting both step volume and variability through PA interventions may yield greater benefits in BP control, particularly among participants with hypertension and a higher chronic disease burden.

Electronic-Structure-Modulated Cu,Co-Coanchored N-Doped Nanocarbon as a Difunctional Electrocatalyst for Hydrogen Evolution and Oxygen Reduction Reactions.

To alleviate the problems of environmental pollution and energy crisis, aggressive development of clean and alternative energy technologies, in particular, water splitting, metal-air batteries, and fuel cells involving two key half reactions comprising hydrogen evolution reaction (HER) and oxygen reduction (ORR), is crucial. In this work, an innovative hybrid comprising heterogeneous Cu/Co bimetallic nanoparticles homogeneously dispersed on a nitrogen-doped carbon layer (Cu/Co/NC) was constructed as a bifunctional electrocatalyst toward HER and ORR via a hydrothermal reaction along with post-solid-phase sintering technique. Thanks to the interfacial coupling and electronic synergism between the Cu and Co bimetallic nanoparticles, the Cu/Co/NC catalyst showed improved catalytic ORR activity with a half-wave potential of 0.865 V and an excellent stability of more than 30 h, even compared to 20 wt% Pt/C. The Cu/Co/NC catalyst also exhibited excellent HER catalytic performance with an overpotential of below 149 mV at 10 mA/cm2 and long-term operation for over 30 h.

A comprehensive pan-cancer analysis revealing SPAG6 as a novel diagnostic, prognostic and immunological biomarker in tumor.

Background: There have been studies on the role of sperm-associated antigen 6 (SPAG6) in cytoskeleton formation and growth cone stability, but it is also unknown how spag6 affect tumor growth and development. The aim of this study was to clarify the role of SPAG6 in pan-cancer, with some findings about thyroid carcinoma (THCA) validated through experiments. Methods: We examined the role of SPAG6 in pan-cancer, with the data being collected from databases. Further analysis was conducted to assess its correlations with prognosis, gene heterogeneity, stemness, and tumor immunity. The interacting proteins of SPAG6 were also identified, and gene ontology enrichment analysis was performed to determine its biological function. We preliminarily confirmed the role of SPAG6 via in vitro experiments and immunofluorescence staining. Results: This study found that SPAG6 expression was differentially expressed in cancers and at various tumor stages and grades. In stomach and esophageal carcinoma (STES), stomach adenocarcinoma (STAD), kidney renal clear cell carcinoma (KIRC), lung squamous cell carcinoma (LUSC), and adrenocortical carcinoma (ACC), SPAG6 expression was correlated with gender. SPAG6 expression was also found to be correlated with prognostic value, with low expression being associated with poor prognosis. Furthermore, SPAG6 expression was positively linked with immune-related cells in HNSC, chemokine receptors in LUSC, and immune checkpoint genes in THCA. Furthermore, SPAG6 overexpression suppressed the malignant phenotypes of THCA cells, manifested by slower proliferation and decreased migration. The different SPAG6 expression in THCA led to different malignant phenotypes, which are involved in the upregulation of DNA repair, MYC targets, peroxisome, and G2M checkpoint. Conclusions: SPAG6 plays a significant role as an oncogene and can be used as a marker to predict the prognosis of cancer. SPAG6 influences both the tumor immune infiltration and microenvironment, making it a promising immunotherapeutic target for tumor therapy.

Structural and spectroscopic insights into fucoxanthin chlorophyll a/c-binding proteins of diatoms in diverse oligomeric states.

Diatoms, a group of prevalent marine algae, significantly contribute to global primary productivity. Their substantial biomass is linked to enhanced absorption of blue-green light underwater, facilitated by fucoxanthin chlorophyll a/c-binding proteins (FCPs), exhibiting oligomeric diversity across diatom species. Utilizing mild CN-PAGE analysis on solubilized thylakoid membranes, we displayed monomeric, dimeric, trimeric, tetrameric and pentameric FCPs in diatoms. Mass spectrometry analysis revealed each oligomeric FCP has specific protein compositions, constituting a large Lhcf family of FCP antennas. In addition, we resolved the structures of Thalassiosira pseudonana FCP (Tp-FCP) homotrimer and Chaetoceros gracilis FCP (Cg-FCP) pentamer by cryo-electron microscopy at 2.73 Å and 2.65 Å resolutions, respectively. The distinct pigment composition and organization in various oligomeric FCPs change their blue-green light-harvesting, excitation energy transfer pathways. In comparison to dimeric and trimeric FCPs, Cg-FCP tetramer and Cg-FCP pentamer exhibit stronger absorption by Chls c, red-shifted and broader Chl a fluorescence emission, as well as more robust circular dichroism signals originating from Chl a-carotenoid dimers. These spectroscopic characteristics indicate that Chl a molecules in Cg-FCP tetramer and Cg-FCP pentamer are more heterogeneous than in both dimers and Tp-FCP trimer. The structural and spectroscopic insights provided by this study contribute to a better understanding of the mechanisms that empower diatoms to adapt to fluctuating light environments.

Clinical Effect of the Modified Morrow Septal Myectomy Procedure for Biventricular Hypertrophic Cardiomyopathy.

Background: Right ventricular involvement in hypertrophic cardiomyopathy is uncommon. This study aimed to evaluate clinical outcomes of the modified septal myectomy in patients diagnosed with biventricular hypertrophic cardiomyopathy (BHCM), a subject seldom explored in the literature. Methods: We conducted a retrospective cohort study from January 2019 to January 2023, enrolling 12 patients with BHCM. Each patient underwent a modified septal myectomy and was followed postoperatively. Clinical data and echocardiographic parameters, including the ventricular outflow tract peak pressure gradient and maximum interventricular septum thickness, were collected and analyzed. Results: The study cohort had a median age of 43.0 (interquartile range 14.5-63.0) years at surgery, with four patients (33.3%) being children. Two patients (16.7%) previously underwent percutaneous transluminal septal myocardial ablation. Surgical relief of biventricular outflow tract obstruction (BVOTO) was achieved in five patients (41.7%), aside from those managed solely for left ventricular outflow tract obstruction. In five instances, three-dimensional (3D) printing technology assisted in surgical planning. The postoperative interventricular septum thickness was significantly reduced (21.0 mm preoperative vs. 14.5 mm postoperative, p < 0.001), effectively eliminating residual ventricular outflow tract obstruction. There were no severe complications, such as septal perforation or third-degree atrioventricular block. During a mean follow up of 21.2 ± 15.3 months, no sudden deaths, residual outflow tract obstruction, permanent pacemaker implantation, recurrent systolic anterior motion, or reoperations were reported. Conclusions: Our findings affirm that the modified septal myectomy remains the gold standard treatment for BHCM, improving patient symptoms and quality of life. BVOTO relief can be safely and effectively achieved through septal myectomy via transaortic and pulmonary valve approaches in selected patients. For intricate cases, the application of 3D printing technology as a preoperative planning tool is advised to optimize surgical precision and safety.

Association between metabolic dysfunction-associated steatotic liver disease and risk of colorectal cancer or colorectal adenoma: an updated meta-analysis of cohort studies.

Background and aims: In recent years, the relationship between metabolic dysfunction-associated steatotic liver disease (MASLD) and colorectal cancer (CRC) or colorectal adenoma (CRA) has gained widespread attention. Previous meta-analyses on this subject either incorporated numerous cross-sectional studies, which were susceptible to bias, or concentrated solely on a restricted number of cohort studies. Moreover, with the release of a substantial number of high-quality cohort studies on this subject in the past two years, the findings continue to be debated and contradictory. Therefore, we conducted an updated systematic review and meta-analysis of cohort studies to quantitatively evaluate the magnitude of the association between them. Methods: Comprehensive searches of PubMed, Web of Science, and Embase were conducted without language restrictions from the time of their creation up to December, 2023. The pooled hazard ratios (HRs) with 95% confidence interval (CIs) were calculated by the generic inverse variance based on the random-effects model. Moreover, subgroup and sensitivity analyses were performed. Results: A total of 15 cohort studies were analyzed in this meta-analysis, which included 9,958,412 participants. The meta-analysis of 13 cohort studies showed that MASLD was linked to a higher risk of CRC (HR=1.25, 95% CI: 1.15-1.36, P < 0.00001). Additionally, further subgroup analysis indicated that the combined HR remained consistent regardless of the study location, nomenclature of fatty liver disease (FLD), confirmation methods for FLD, sample size, follow-up time, and study quality. Furthermore, the meta-analysis of four cohort studies demonstrated that MASLD was correlated with an increased risk of CRA (HR=1.38, 95% CI: 1.17-1.64, P = 0.0002). The sensitivity analysis results further validated the robustness of the aboved findings. Conclusion: The results of our meta-analysis indicated that MASLD was associated with an increased risk of incident CRC/CRA. In the future, it is necessary to conduct more prospective cohort studies to thoroughly assess potential confounding factors, particularly in individuals from Europe and North America. Furthermore, related mechanism studies should be conducted to enhance our understanding of the link between MASLD and CRC/CRA. Systematic review registration: Open Science Framework registries (https://osf.io/m3p9k).

Effect and Safety of Apatinib as Neoadjuvant Therapy in Locally Advanced Differentiated Thyroid Cancer: A Phase 2 Trial.

Context: Presently, there is a paucity of prospective clinical trials investigating neoadjuvant therapy for locally advanced thyroid cancer. Objective: This study was a multicenter, open-label, single-arm, phase II trial evaluating the efficacy and safety of apatinib as neoadjuvant therapy in patients with local advanced differentiated thyroid cancer (DTC). Methods: Patients were treated with preoperative apatinib over a course of 2 to 4 cycles, culminating in surgical resection. The primary endpoints were objective response rate (ORR) and disease control rate (DCR); the secondary endpoints were the rate of R0 surgery, alterations in serum thyroglobulin levels, disease-free survival, and adverse events (AEs). Results: A total of 14 patients who met the inclusion criteria were administered neoadjuvant apatinib. Among these, 13 patients underwent surgical procedures following apatinib treatment and were enrolled in the ITT population. The ORR was 53.8% and the DCR was 100%. Of the patients, 84.6% received R0 surgery, while the remaining 15.4% underwent R1 resection. Predominant among the observed AEs were hypertension, hand-foot syndrome, hepatic dysfunction, proteinuria, and hypothyroidism, with no instances of grade 4 or 5 AEs reported. Subsequent to surgery, patients were followed up for a median period of 34 months, during which disease progression occurred in 5 individuals (35.7%), encompassing 3 cases of locoregional recurrences and 2 cases of distant metastases. Conclusion: Apatinib may be an effective agent in the use of neoadjuvant therapy for locally advanced DTC. Patients may therefore benefit from surgical outcomes and their long-term prognosis.

Symbolic recording of signalling and cis-regulatory element activity to DNA.

Measurements of gene expression or signal transduction activity are conventionally performed using methods that require either the destruction or live imaging of a biological sample within the timeframe of interest. Here we demonstrate an alternative paradigm in which such biological activities are stably recorded to the genome. Enhancer-driven genomic recording of transcriptional activity in multiplex (ENGRAM) is based on the signal-dependent production of prime editing guide RNAs that mediate the insertion of signal-specific barcodes (symbols) into a genomically encoded recording unit. We show how this strategy can be used for multiplex recording of the cell-type-specific activities of dozens to hundreds of cis-regulatory elements with high fidelity, sensitivity and reproducibility. Leveraging signal transduction pathway-responsive cis-regulatory elements, we also demonstrate time- and concentration-dependent genomic recording of WNT, NF-κB and Tet-On activities. By coupling ENGRAM to sequential genome editing via DNA Typewriter1, we stably record information about the temporal dynamics of two orthogonal signalling pathways to genomic DNA. Finally we apply ENGRAM to integratively record the transient activity of nearly 100 transcription factor consensus motifs across daily windows spanning the differentiation of mouse embryonic stem cells into gastruloids, an in vitro model of early mammalian development. Although these are proof-of-concept experiments and much work remains to fully realize the possibilities, the symbolic recording of biological signals or states within cells, to the genome and over time, has broad potential to complement contemporary paradigms for how we make measurements in biological systems.

Shared Genetic Architectures between Coronary Artery Disease and Type 2 Diabetes Mellitus in East Asian and European Populations.

Coronary artery disease (CAD) is a common comorbidity of type 2 diabetes mellitus (T2DM). However, the pathophysiology connecting these two phenotypes remains to be further understood. Combined analysis in multi-ethnic populations can help contribute to deepening our understanding of biological mechanisms caused by shared genetic loci. We applied genetic correlation analysis and then performed conditional and joint association analyses in Chinese, Japanese, and European populations to identify the genetic variants jointly associated with CAD and T2DM. Next, the associations between genes and the two traits were also explored. Finally, fine-mapping and functional enrichment analysis were employed to identify the potential causal variants and pathways. Genetic correlation results indicated significant genetic overlap between CAD and T2DM in the three populations. Over 10,000 shared signals were identified, and 587 were shared by East Asian and European populations. Fifty-six novel shared genes were found to have significant effects on both CAD and T2DM. Most loci were fine-mapped to plausible causal variant sets. Several similarities and differences of the involved genes in GO terms and KEGG pathways were revealed across East Asian and European populations. These findings highlight the importance of immunoregulation, neuroregulation, heart development, and the regulation of glucose metabolism in shared etiological mechanisms between CAD and T2DM.

Gold nanoparticle-decorated fluorine-doped tin oxide substrate for sensitive label-free OIRD microarray chips.

Oblique incidence reflectance difference (OIRD) is an emerging technique enabling real-time and label-free detection of bio-affinity binding events on microarrays. The interfacial architecture of the microarray chip is critical to the performance of OIRD detection. In this work, a sensitive label-free OIRD microarray chip was developed by using gold nanoparticle-decorated fluorine-doped tin oxide (AuNPs-FTO) slides as a chip substrate. This AuNPs-FTO chip demonstrates a higher signal-to-noise ratio and improved sensitivity compared to that built on FTO glass, showing a detection limit of as low as 10 ng mL-1 for the model target, HRP-conjugated streptavidin. On-chip ELISA experiments and optical calculations suggest that the enhanced performance is not only due to the higher probe density enabling a high capture efficiency toward the target, but most importantly, the AuNP layer arouses optical interference to improve the intrinsic sensitivity of OIRD. This work provides an effective strategy for constructing OIRD-based microarray chips with enhanced sensitivity, and may help extend their practical applications in various fields.

Mammalian orthoreovirus capsid protein σ3 antagonizes RLR-mediated antiviral responses by degrading MAVS.

Mammalian orthoreovirus (MRV) outer capsid protein σ3 is a multifunctional protein containing a double-stranded RNA-binding domain, which facilitates viral entry and assembly. We reasoned that σ3 has an innate immune evasion function. Here, we show that σ3 protein localizes in the mitochondria and interacts with mitochondrial antiviral signaling protein (MAVS) to activate the intrinsic mitochondria-mediated apoptotic pathway. Consequently, σ3 protein promotes the degradation of MAVS through the intrinsic caspase-9/caspase-3 apoptotic pathway. Moreover, σ3 protein can also inhibit the expression of the components of the RNA-sensing retinoic acid-inducible gene (RIG)-like receptor (RLR) signaling pathway to block antiviral type I interferon responses. Mechanistically, σ3 inhibits RIG-I and melanoma differentiation-associated gene 5 expression is independent of its inhibitory effect on MAVS. Overall, we demonstrate that the MRV σ3 protein plays a vital role in negatively regulating the RLR signaling pathway to inhibit antiviral responses. This enables MRV to evade host defenses to facilitate its own replication providing a target for the development of effective antiviral drugs against MRV. IMPORTANCE: Mammalian orthoreovirus (MRV) is an important zoonotic pathogen, but the regulatory role of its viral proteins in retinoic acid-inducible gene-like receptor (RLR)-mediated antiviral responses is still poorly understood. Herein, we show that MRV σ3 protein co-localizes with mitochondrial antiviral signaling protein (MAVS) in the mitochondria and promotes the mitochondria-mediated intrinsic apoptotic pathway to cleave and consequently degrade MAVS. Furthermore, tryptophan at position 133 of σ3 protein plays a key role in the degradation of MAVS. Importantly, we show that MRV outer capsid protein σ3 is a key factor in antagonizing RLR-mediated antiviral responses, providing evidence to better unravel the infection and transmission mechanisms of MRV.

Multiplex profiling of developmental cis-regulatory elements with quantitative single-cell expression reporters.

The inability to scalably and precisely measure the activity of developmental cis-regulatory elements (CREs) in multicellular systems is a bottleneck in genomics. Here we develop a dual RNA cassette that decouples the detection and quantification tasks inherent to multiplex single-cell reporter assays. The resulting measurement of reporter expression is accurate over multiple orders of magnitude, with a precision approaching the limit set by Poisson counting noise. Together with RNA barcode stabilization via circularization, these scalable single-cell quantitative expression reporters provide high-contrast readouts, analogous to classic in situ assays but entirely from sequencing. Screening >200 regions of accessible chromatin in a multicellular in vitro model of early mammalian development, we identify 13 (8 previously uncharacterized) autonomous and cell-type-specific developmental CREs. We further demonstrate that chimeric CRE pairs generate cognate two-cell-type activity profiles and assess gain- and loss-of-function multicellular expression phenotypes from CRE variants with perturbed transcription factor binding sites. Single-cell quantitative expression reporters can be applied in developmental and multicellular systems to quantitatively characterize native, perturbed and synthetic CREs at scale, with high sensitivity and at single-cell resolution.

High-Entropy Ceramics Enhanced Droplet Electricity Generator for Energy Harvesting and Bacterial Detection.

The droplet electricity generator (DEG) is a solid-liquid triboelectric nanogenerator with transistor-inspired bulk effect, which is regarded as an effective strategy for raindrop energy harvesting. However, further enhancement of DEG output voltage is necessary to enable its widespread applications. Here, high-entropy ceramics are integrated into the design of DEG intermediate layer for the first time, achieving a high output voltage of 525 V. High-entropy ceramics have colossal dielectric constant, which can help to reduce the triboelectric charge decay for DEG. Furthermore, the effect of factors on DEG output performance when employing high-entropy ceramics as the intermediate layer is extensively analyzed, and the underlying mechanisms and mathematical models are explored. Finally, the enhanced output voltage of DEG not only facilitates faster energy harvesting but also develops a novel method for rapid bacterial detection. This work successfully integrates high-entropy ceramics into DEG design, significantly enhances the output voltage, and offers a novel direction for DEG development.

Label-free OIRD detection of protein microarrays on high dielectric constant substrate with enhanced intrinsic sensitivity.

Oblique-incidence reflectivity difference (OIRD) is a dielectric constant-sensitive technique and exhibits intriguing applications in label-free and high-throughput detection of protein microarrays. With the outstanding advantage of being compatible with arbitrary substrates, however, the effect of the substrate, particularly its dielectric constant on the OIRD sensitivity has not been fully disclosed. In this paper, for the first time we investigated the dependence of OIRD sensitivity on the dielectric constant of the substrate under top-incident OIRD configuration by combining theoretical modeling and experimental evaluation. Optical modeling suggested that the higher dielectric constant substrate exhibits a higher intrinsic sensitivity. Experimentally, three substrates including glass, fluorine-doped tin oxide (FTO) and silicon (Si) with different dielectric constants were selected as microarray substrates and their detection performances were evaluated. In good agreement with the modeling, high dielectric constant Si-based microarray exhibited the highest sensitivity among three chips, reaching a detection limit of as low as 5 ng mL-1 with streptavidin as the model target. Quantification of captured targets on three chips with on-chip enzyme-linked immunosorbent assay (ELISA) further confirmed that the enhanced performance originates from the high dielectric constant enhanced intrinsic OIRD sensitivity. This work thus provides a new way to OIRD-based label-free microarrays with improved sensitivity.

Impact of nomenclature as metabolic associated steatotic liver disease on steatotic liver disease prevalence and screening: a prospective population survey in Asians.

BACKGROUND AND AIM: The introduction of the latest nomenclature, metabolic associated steatotic liver disease (MASLD), proposed by the multi-society without Asian society consensus statement, aims to redefine the diagnostic criteria for metabolic associated fatty liver disease (MAFLD). However, its effect on the epidemiology in Asia remains unclear. METHOD: We conducted a population-based cross-sectional survey on fatty liver disease using multistage stratified random sampling of participants from Guangzhou, a representative area in China (ChiCTR2000033376). Demographic, socioeconomic, lifestyle, and laboratory data were collected. Hepatic steatosis and the severity of fibrosis were assessed using FibroScan. RESULTS: A total of 7388 individuals were recruited, the proportion of which meeting the definitions for nonalcoholic fatty liver disease (NAFLD), MAFLD, and MASLD were 2359 (31.9%), 2666 (36.1%), and 2240 (30.3%), respectively. One hundred and twenty (1.6%) patients had cryptogenic SLD, and 537 (7.3%) patients were diagnosed with MetALD. MASLD did not significantly differ from NAFLD and MAFLD, except that MAFLD patients had a lower proportion of males, hypertension, and diabetes and were less likely to consume tea (P < 0.05). Both cryptogenic SLD and MASLD non-MAFLD patients exhibited milder hepatic steatosis and a lower frequency of liver injury than NAFLD, MAFLD, or MASLD patients (all P < 0.05). An increased HOMA-IR (adjusted OR: 1.33, 95% CI: 1.10-2.03) was associated with higher risk of moderate-to-severe steatosis for MASLD non-MAFLD patients, while consuming more cups of tea (P for trend = 0.015) showed inverse associations. CONCLUSION: Irrespective of terminology used is that fatty liver disease is highly prevalent in the Han Chinese population. Differences in insulin resistance and lifestyle risk factors are associated with redefinition disparities.

Identification and characterization of the CRK gene family in the wheat genome and analysis of their expression profile in response to high temperature-induced male sterility.

Cysteine-rich receptor-like kinases (CRKs) play many important roles during plant development, including defense responses under both biotic and abiotic stress, reactive oxygen species (ROS) homeostasis, callose deposition and programmed cell death (PCD). However, there are few studies on the involvement of the CRK family in male sterility due to heat stress in wheat (Triticum aestivum L.). In this study, a genome-wide characterization of the CRK family was performed to investigate the structural and functional attributes of the wheat CRKs in anther sterility caused by heat stress. A total of 95 CRK genes were unevenly distributed on 18 chromosomes, with the most genes distributed on chromosome 2B. Paralogous homologous genes with Ka/Ks ratios less than 1 may have undergone strong purifying selection during evolution and are more functionally conserved. The collinearity analysis results of CRK genes showed that wheat and Arabidopsis (A. thaliana), foxtail millet, Brachypodium distachyon (B. distachyon), and rice have three, 12, 15, and 11 pairs of orthologous genes, respectively. In addition, the results of the network interactions of genes and miRNAs showed that five miRNAs were in the hub of the interactions map, namely tae-miR9657b-5p, tae-miR9780, tae-miR9676-5p, tae-miR164, and tae-miR531. Furthermore, qRT-PCR validation of the six TaCRK genes showed that they play key roles in the development of the mononuclear stage anthers, as all six genes were expressed at highly significant levels in heat-stressed male sterile mononuclear stage anthers compared to normal anthers. We hypothesized that the TaCRK gene is significant in the process of high-temperature-induced sterility in wheat based on the combination of anther phenotypes, paraffin sections, and qRT-PCR data. These results improve our understanding of their relationship.

Functional characterization of Fagopyrum tataricum ZIP gene family as a metal ion transporter.

The zinc/iron-regulated transporter-like proteins (ZIP) family acts as an important transporter for divalent metal cations such as Zn, Fe, Mn, Cu, and even Cd. However, their condition is unclear in Tartary buckwheat (Fagopyrum tataricum). Here, 13 ZIP proteins were identified and were predicted to be mostly plasma membrane-localized. The transient expressions of FtZIP2 and FtZIP6 in tobacco confirmed the prediction. Multiple sequence alignment analysis of FtZIP proteins revealed that most of them had 8 putative transmembrane (TM) domains and a variable region rich in histidine residues between TM3 and TM4, indicating the reliable affinity to metal ions. Gene expression analysis by qRT-PCR showed that FtZIP genes were markedly different in different organs, such as roots, stems, leaves, flowers, fruits and seeds. However, in seedlings, the relative expression of FtZIP10 was notably induced under the CdCl2 treatment, while excessive Zn2+, Fe2+, Mn2+ and Cd2+ increased the transcript of FtZIP5 or FtZIP13, in comparison to normal conditions. Complementation of yeast mutants with the FtZIP family genes demonstrate that FtZIP7/10/12 transport Zn, FtZIP5/6/7/9/10/11 transport Fe, FtZIP12 transports Mn and FtZIP2/3/4/7 transport Cd. Our data suggest that FtZIP proteins have conserved functions of transportation of metal ions but with distinct spatial expression levels.

Structure and distinct supramolecular organization of a PSII-ACPII dimer from a cryptophyte alga Chroomonas placoidea.

Cryptophyte algae are an evolutionarily distinct and ecologically important group of photosynthetic unicellular eukaryotes. Photosystem II (PSII) of cryptophyte algae associates with alloxanthin chlorophyll a/c-binding proteins (ACPs) to act as the peripheral light-harvesting system, whose supramolecular organization is unknown. Here, we purify the PSII-ACPII supercomplex from a cryptophyte alga Chroomonas placoidea (C. placoidea), and analyze its structure at a resolution of 2.47 Å using cryo-electron microscopy. This structure reveals a dimeric organization of PSII-ACPII containing two PSII core monomers flanked by six symmetrically arranged ACPII subunits. The PSII core is conserved whereas the organization of ACPII subunits exhibits a distinct pattern, different from those observed so far in PSII of other algae and higher plants. Furthermore, we find a Chl a-binding antenna subunit, CCPII-S, which mediates interaction of ACPII with the PSII core. These results provide a structural basis for the assembly of antennas within the supercomplex and possible excitation energy transfer pathways in cryptophyte algal PSII, shedding light on the diversity of supramolecular organization of photosynthetic machinery.

A metabotropic glutamate receptor agonist enhances visual signal fidelity in a mouse model of retinitis pigmentosa.

Many inherited retinal diseases target photoreceptors, which transduce light into a neural signal that is processed by the downstream visual system. As photoreceptors degenerate, physiological and morphological changes to retinal synapses and circuitry reduce sensitivity and increase noise, degrading visual signal fidelity. Here, we pharmacologically targeted the first synapse in the retina in an effort to reduce circuit noise without sacrificing visual sensitivity. We tested a strategy to partially replace the neurotransmitter lost when photoreceptors die with an agonist of receptors that ON bipolars cells use to detect glutamate released from photoreceptors. In rd10 mice, which express a photoreceptor mutation that causes retinitis pigmentosa (RP), we found that a low dose of the mGluR6 agonist l-2-amino-4-phosphonobutyric acid (L-AP4) reduced pathological noise induced by photoreceptor degeneration. After making in vivo electroretinogram recordings in rd10 mice to characterize the developmental time course of visual signal degeneration, we examined effects of L-AP4 on sensitivity and circuit noise by recording in vitro light-evoked responses from individual retinal ganglion cells (RGCs). L-AP4 decreased circuit noise evident in RGC recordings without significantly reducing response amplitudes, an effect that persisted over the entire time course of rod photoreceptor degeneration. Subsequent in vitro recordings from rod bipolar cells (RBCs) showed that RBCs are more depolarized in rd10 retinas, likely contributing to downstream circuit noise and reduced synaptic gain, both of which appear to be ameliorated by hyperpolarizing RBCs with L-AP4. These beneficial effects may reduce pathological circuit remodeling and preserve the efficacy of therapies designed to restore vision.