Manipulation and elimination of circulating tumor cells using multi-responsive nanosheet for malignant tumor therapy

Tumor recurrence caused by metastasis is a major cause of death for patients. Thus, a strategy to manipulate the circulating tumor cells (CTCs, initiators of tumor metastasis ) and eliminate them along with the primary tumor has significant clinical significance for malignant tumor therapy. In this study, a magnet-NIR-pH multi-responsive nanosheet (Fe₃O₄@SiO₂-GO-PEG-FA/AMP-DOX, FGPFAD) was fabricated to capture CTCs in circulation, then magnetically transport them to the primary tumor, and finally perform NIR-dependent photothermal therapy as well as acidic-environment-triggered chemotherapy to destroy both the CTCs and the primary tumor. The FGPFAD nanosheet consists of silica-coated ferroferric oxide nanoparticles (Fe₃O₄@SiO₂, magnetic targeting agent), graphene oxide (GO, photothermal therapy agent), polyethylene glycol (PEG, antifouling agent for sustained circulation), folic acid (FA, capturer of CTCs) and antimicrobial-peptide-conjugated doxorubicin (AMP-DOX, agent for chemotherapy), in which the AMP-DOX was bound to the FGPFAD nanosheet via a cleavable Schiff base to achieve acidic-environment-triggered drug release for tumor-specific chemotherapy. Both in vitro and in vivo results indicated that the effective capture and magnetically guided transfer of CTCs to the primary tumor, as well as the multimodal tumor extermination performed by our FGPFAD nanosheet, significantly inhibited the primary tumor and its metastasis.

Measuring quality of reporting in systematic reviews of diagnostic test accuracy studies in medical imaging: comparison of PRISMA-DTA and PRISMA

OBJECTIVES

To compare the reporting quality measured by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy studies (PRISMA-DTA) vs the original PRISMA checklist for systematic reviews of diagnostic test accuracy studies in imaging and survey the use of PRISMA-DTA by researchers and endorsement by journals.

METHODS

Systematic reviews of DTA studies published in 2020 and 2021 in Quartile 1 and Quartile 3 medical imaging journals (defined by Journal Citation Reports) were identified through PubMed. The reporting of each systematic review was assessed using PRISMA-DTA, PRISMA-2009 and PRISMA-2020. The item scores and overall score were compared among the three checklists. We also examined checklist adoption by the included systematic reviews and surveyed checklist endorsement from author instructions of included journals.

RESULTS

A total of 173 systematic reviews from 66 journals were included. The use of PRISMA-DTA, compared with PRISMA-2009 and PRISMA-2020, identified more issues in the reporting of title (proportion of systematic reviews with proper reporting, 27.2% vs 98.8% vs 98.8%), abstract (39.3% vs 97.1% vs 64.7%), eligibility criteria (67.6% vs 94.2% vs 94.2%), search (28.9% vs 72.3% vs 28.9%), definitions for data extraction (14.5% vs 91.9% vs 91.9%), diagnostic accuracy measures (38.2% vs 93.6% vs 93.6%), synthesis of results (28.9% vs 89.6% vs 73.4%) and results of individual studies (40.5% vs 80.3% vs 80.3%). The overall median reporting score measured by PRISMA-DTA (72.0% (interquartile range (IQR), 66.7-77.8%)) was lower than that measured by PRISMA-2009 (88.9% (IQR, 84.0-92.6%)) and similar to that measured by PRISMA-2020 (74.1% (IQR, 66.7-77.8%)). Additionally, PRISMA-DTA was used by only 43 (24.9%) systematic reviews and endorsed by two (3.0%) journals. These trends remained consistent for reviews published in journals with diverse scientific impact.

CONCLUSIONS

The use of PRISMA-DTA may identify more reporting inadequacies compared with the original PRISMA checklists when assessing diagnostic test accuracy systematic reviews, especially in critical sections such as title, abstract and methods. However, this tool is not commonly used by researchers and is inadequately endorsed by imaging journals. Our findings suggest a strong need to use PRISMA-DTA for reporting of diagnostic test accuracy systematic reviews by authors and its endorsement by journals. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Hypoglycemia as a potential risk for patients taking clopidogrel: A systematic review and meta-analysis

BACKGROUND

Clopidogrel is a cornerstone antiplatelet drug used in cardiovascular, cerebrovascular, and peripheral artery diseases. The sulfhydryl group of clopidogrel metabolite could induce insulin autoimmune syndrome (IAS) with hypoglycemia as the major symptom. Discontinuing clopidogrel and substituting it with ticagrelor has been revealed as an effective treatment in previous studies. Since hypoglycemia serves as a risk factor for cardiovascular and cerebrovascular events, we aimed to determine the association between hypoglycemia/IAS and clopidogrel and to investigate whether clopidogrel is a modifiable and causal risk factor of hypoglycemia/IAS.

METHODS

MEDLINE, Embase, Cochrane databases, and clinical trial registries were searched for randomized controlled trials (RCTs) of clopidogrel from inception to 28 February 2022. RCTs comparing clopidogrel with placebo or other antiplatelet drugs were eligible if meeting the inclusion criteria: 1) clopidogrel was administrated 75 mg qd orally as a long-term antiplatelet prescription at least for months, and 2) hypoglycemia-inducible drugs were not used in the control arm. One investigator abstracted articles and performed a quality assessment. Uncertainties were resolved by discussions with two investigators independently. Odds ratio (OR) and risk difference (RD) were calculated and performed with subgroup analyses. The pre-specified protocol was registered in PROSPERO (CRD42022299622).

RESULTS

Six trials with 61,399 participants in total fulfilled the criteria and were included in the meta-analysis. Clopidogrel might not be associated with higher hypoglycemia odds (OR 0.95, 95% CI 0.65 to 1.40). However, Asian participants (p = 0.0437) seemed more likely to develop clopidogrel-associated hypoglycemia. Clopidogrel-associated hypoglycemia occurred at the highest rate of 0.03% (RD -0.00023, 95% CI -0.00077 to 0.00031), and this increased to 0.91% (RD 0.00210, 95% CI -0.00494 to 0.00914) in an aging population and to 0.18% (RD 0.00040, 95% CI -0.00096 to 0.00177) when Asian ratio of the population was elevated.

CONCLUSIONS

We raise the concern that clopidogrel might be a modifiable and causal risk factor of hypoglycemia. The Asian population might be more vulnerable and need additional care.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, identifier CRD42022299622.

Hearing Impairment and Incident Frailty in Later Life: The Health in Men Study (HIMS)

OBJECTIVES

This study is designed to determine if hearing loss is associated with increased risk of frailty in later life.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

We retrieved data of a community sample of men aged 70 years and above living in the metropolitan region of Perth, Western Australia. 3,285 participants who were free of frailty at the beginning of the study were followed for up to 17 years. Data were retrieved from the Health in Men Study (HIMS) and the Western Australian Data Linkage System (WADLS).

MEASUREMENTS

Hearing loss was defined by self-report or by diagnosis recorded in the WADLS. Incident frailty was assessed using the Hospital Frailty Risk Score (HFRS).

RESULTS

A total of 2,348 (71.5%) men developed frailty during follow up. The adjusted hazard ratio was 1.03 (95% CI: 0.95-1.12). The majority of the participants became frail by age 90 regardless of hearing condition. The time point where half of the group become frail was delayed by 14.4 months for men without hearing loss compared with hearing impaired men.

CONCLUSIONS

Hearing loss is not associated with incident frailty in men aged 70 years or older when frailty was measured by HFRS. However, this statistically non-significant result could be due to the low sensitivity of study measures. Also, we found a trend that men with hearing loss were more likely to develop frailty compared with their normal-hearing peers, suggesting a potential association between hearing loss and frailty.

Supporting immigrant caregivers during the COVID-19 pandemic: Continuous adaptation and implementation of an early childhood digital engagement program

Digital messaging programs have the potential to be a powerful, low-cost, technological tool to support multiple facets of caregivers' knowledge, and implementation of developmentally appropriate caregiver-child activities among diverse immigrant populations. However, involving caregivers and community stakeholders in the cultural and linguistic tailoring of interventions to optimize utilization and engagement may be critical to ensuring messaging programs' usability and acceptability. The purpose of this mixed-method study was to use the dynamic adaptation process (DAP) within an Exploration, Preparation, Implementation, Sustainment (EPIS) framework to examine the implementation of a digital messaging program, developed at the beginning of the COVID-19 pandemic, aimed at providing Spanish-, English-, and Mandarin-speaking immigrant caregivers with caregiver-child activities that supported children's development and caregivers' knowledge. Building upon the EPIS framework, using DAP, we assessed the feasibility and acceptability of a messaging program via short message service or multimedia message service, WeChat, and Remind and webinar program during the COVID-19 pandemic. The study illustrated how a digital messaging program is a feasible mechanism for sharing developmentally and culturally appropriate information with immigrant caregivers. In addition, the use of the DAP and the EPIS framework allowed us to continuously track the process of cultural adaptation, identify barriers and facilitators of the outreach program, and examine how implementation unfolded across all three groups of caregivers.

Direct adsorption sampling and ambient mass spectrometry analysis of tobacco smoke with porous paper strips

Chemical analysis of atmospheric aerosols by conventional analytical methods is usually required to perform complicated and time-consuming sample preparation processes. In recent decades, ambient ionization mass spectrometry (AI-MS) methods have been proven to be simple, rapid, and effective analytical tools for direct analysis of various complex samples. In this work, we applied porous paper filters for direct adsorptive sampling of tobacco smoke, and then the sampled paper filters were performed the emitters of the paper spray ionization (PSI) device. An auto-sampling device was made to control the generation and collection of tobacco smoke. Nicotine, the typical compound of tobacco smoke, was used to optimize the key conditions of auto-sampling. Moreover, different types of tobacco smoke were also compared with multivariate variable analysis, and the makers of tobacco smoke from different sources of tobacco smoke were investigated. By using this method, direct sampling and analysis of a single tobacco sample can be completed within minutes. Overall, our results show that PSI-MS is a powerful tool that integrates collection, extraction, ionization, and identification analytes in smoke.

[Construction of zebrafish models for screening intracranial hemorrhage associated genes]

Objective: To construct zebrafish models for the screening of intracranial hemorrhage (ICH) associated genes. Methods: ICH zebrafish models were constructed through morpholino oligonucleotides (MOs) technique and microinjection technique, and multiple verification was performed from macro and micro perspectives. First, the normal wild-type AB strain zebrafish injected with control MO was used as the control group, and AB zebrafish embryos microinjected with MOs of genes related to development of neural crest-derived cells (NCDCs) were used as the study group, such as col8a1 MO, tfap2α MO, msx1a MO, msx2 MO, and dkk1a MO. Preliminary verification of the model was conducted under a white-light optical microscope. Then, the model was verified by Tg (flk1: gfp; gata1: dsRed) double transgenic zebrafish, with vascular endothelial cells labeled by green fluorescent protein (GFP) and red blood cell labeled by fluorescent protein (dsRed), and thus the location of cerebral hemorrhage can be observed more clearly. Specifically, zebrafish embryos were microinjected with Control MO as the control group and those microinjected with col8a1 MO as the study group. Then the embryos were cultured until 48 hours post-fertilization to observe the leakage of red blood cells under the confocal laser scanning microscope. Finally, Tg (flk1: gfp) transgenic zebrafish was used to verify the model based on the blood-brain barrier (BBB). Through the leakage of dextran-rhodamine and DAPI dyes, the destruction of BBB and the occurrence of cerebral hemorrhage in zebrafish were further clarified, and quantitative statistics were carried out to verify the relationship between NCDCs development related genes and cerebral hemorrhage phenotype, which proved that the modeling was effective. Results: The zebrafish with col8a1, tfap2α, and msx1 mutations in the study group had apparent ICH compared with wildtype zebrafish, and the prevalence of ICH was 18.18% (52/286), 23.04% (62/251), and 35.94% (23/64), respectively. While, the zebrafish with msx2 and dkk1a mutations rarely had ICH, with the ICH prevalence of 1.03% (1/97) and 1.15% (1/87), respectively. The prevalence of red blood cells leakage in Tg (flk1:gfp; gata1:dsred) double transgenic zebrafish injected with Control Mo and col8a1 Mo was 0.37% (1/273) and 18.18% (52/286) (P<0.001). The number of DAPI positive nuclei of Tg (flk1: gfp) transgenic zebrafish injected with Control Mo and col8a1 Mo was 10.05±5.27 and 60.35±3.96 (P<0.001), and the fluorescent intensity of midbrain parenchymal induced by dextran-rhodamin leakage was 2.54±4.70 and 5.13±3.52 (P<0.001). Conclusion: This study successfully constructs the ICH zebrafish models, and ICH-related genes are screened out, such as col8a1, tfap2α, msx1, and so on.

Horizontal Data Augmentation Strategy for Industrial Quality Prediction

In recent years, neural network-based soft sensor technology has been widely used in industrial production processes and has excellent optimization, monitoring, and quality prediction performance. This paper proposes a horizontal data augmentation strategy to provide highly available data for subsequent prediction models, called the combined autoencoder data augmentation (CADA) strategy. This paper has developed a CADA-based convolutional neural network (CADA-CNN) soft sensor model and applied it to the process of industrial debutanizer and industrial steam volume. In terms of method validation, this paper compares the output data of the proposed CADA by the Spearman correlation coefficient to verify the strategy's feasibility. Then, the output data of the CADA strategy is fed into the artificial neural network (NN), support vector regression (SVR), and convolutional neural network (CNN) for comparison experiments. The final experimental results show that our proposed CADA-CNN model has lower prediction error and better prediction error distribution.

Molecular evolution of vision-related genes may contribute to marsupial photic niche adaptations

Vision plays an essential role in the life of many animals. While most mammals are night-active (nocturnal), many have adapted to novel light environments. This includes diurnal (day-active) and crepuscular (twilight-active) species. Here, we used integrative approaches to investigate the molecular evolution of 112 vision-related genes across 19 genomes representing most marsupial orders. We found that four genes (GUCA1B, GUCY2F, RGR, and SWS2) involved in retinal phototransduction likely became functionally redundant in the ancestor of marsupials, a group of largely obligate nocturnal mammals. We also show evidence of rapid evolution and positive selection of bright-light vision genes in the common ancestor of Macropus (kangaroos, wallaroos, and wallabies). Macropus-specific amino acid substitutions in opsin genes (LWS and SWS1), in particular, may be an adaptation for crepuscular vision in this genus via opsin spectral sensitivity tuning. Our study set the stage for functional genetics studies and provides a stepping stone to future research efforts that fully capture the visual repertoire of marsupials.

[Effect of D-dimer on the prognosis of patients with aneurysmal subarachnoid hemorrhage based on propensity score matching]

Objective: To evaluate the effect of D-dimer on the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods: A total of 1 658 patients who were first diagnosed with aSAH in West China Hospital of Sichuan University from December 2013 to June 2019 were retrospectively analyzed. All patients were divided into four groups according to the median and quartiles of D-dimer level, including 415 cases, 414 cases, 414 cases, and 415 cases in groups Q₁, Q₂, Q₃, and Q₄, respectively. Groups Q₂, Q₃, Q_4, and group Q₁ were matched by propensity score matching (PSM), and the correlation between D-dimer and each outcome was analyzed by logistic regression. Since there is no general clinical classification standard for D-dimer, this study attempted to reclassify patients into groups q1 (<0.55 mg/L, 94 cases), q2 (0.55-1.65 mg/L, 435 cases), q3 (1.65-5.50 mg/L, 650 cases) and q4 (>5.50 mg/L, 303 cases) based on 1, 3, 5, 10 times of the upper limit of the current clinical reference value. Results: The age of 1 658 aSAH patients were (57±12) years, including 1 068 males and 590 females. After PSM based on the median and quartiles of D-dimer level, there were 318 cases, 318 cases, 251 cases, and 229 cases in groups Q₁, Q₂, Q₃, and Q₄, respectively. Compared with group Q₁ (<1.23 mg/L), the risk of in-hospital infection (OR=2.14, 95%CI: 1.47-3.11, P<0.001), pneumonia (OR=2.22, 95%CI: 1.51-3.28, P<0.001), urinary tract infection (OR=1.75, 95%CI: 1.12-2.75, P=0.014) and intracranial rebleeding (OR=3.59, 95%CI: 1.30-9.91, P=0.013) group Q₄ (>4.95 mg/L) was higher. Likewise, the risk of adverse outcomes in group Q₄ was also higher than that in group Q₁, including unfavorable outcome at discharge (OR=2.12, 95%CI: 1.43-3.14, P<0.001), mortality during hospitalization (OR=3.03, 95%CI: 1.26-7.33, P=0.014), mortality within 90 days (OR=2.33, 95%CI:1.29-4.22, P=0.005), mortality within 180 days (OR=1.92, 95%CI: 1.12-3.29, P=0.018), mortality within 1 year (OR=2.07, 95%CI:1.23-3.47, P=0.006) and mortality during the longest follow-up period (OR=1.97, 95%CI:1.26-3.09, P=0.003). After secondary grouping and PSM based on current clinical reference values, there were 90 cases, 87 cases, 90 cases, and 43 cases, respectively in groups q1, q2, q3 and q4. The risk of nosocomial infection (OR=2.26, 95%CI: 1.14-4.45, P=0.019), blood-borne infection (OR=8.86, 95%CI:1.08-72.78, P=0.042), poor prognosis at discharge (OR=4.92, 95%CI: 2.18-11.07, P<0.001), death within 180 days (OR=3.39, 95%CI: 1.04-11.08, P=0.043), death within 1 year (OR=3.23, 95%CI: 1.10-9.49, P=0.033), and death within the longest follow-up period (OR=3.28, 95%CI: 1.34-8.01, P=0.009) was still higher in group q4 than that in group q1. Conclusion: aSAH patients with high D-dimer level have a higher risk of complications and mortality during hospitalization and worse clinical prognosis.

CCL17 acts as a novel therapeutic target in pathological cardiac hypertrophy and heart failure

Circulating proteomic signatures of age are closely associated with aging and age-related diseases; however, the utility of changes in secreted proteins in identifying therapeutic targets for diseases remains unclear. Serum proteomic profiling of an age-stratified healthy population and further community-based cohort together with heart failure patients study demonstrated that circulating C-C motif chemokine ligand 17 (CCL17) level increased with age and correlated with cardiac dysfunction. Subsequent animal experiments further revealed that Ccll7-KO significantly repressed aging and angiotensin II (Ang II)–induced cardiac hypertrophy and fibrosis, accompanied by the plasticity and differentiation of T cell subsets. Furthermore, the therapeutic administration of an anti-CCL17 neutralizing antibody inhibited Ang II–induced pathological cardiac remodeling. Our findings reveal that chemokine CCL17 is identifiable as a novel therapeutic target in age-related and Ang II–induced pathological cardiac hypertrophy and heart failure.

[A nationalsurveyandresults analysisof seizure prophylaxis after aneurismal subarachnoid hemorrhage]

Investigate theclinical practice of seizure prophylaxis after aneurysmal subarachnoid hemorrhage in Chinese neurosurgeons.Aquestionnaire for this theme was designed and was sent to respondents through the internet.From July 2021 to October 2021, atotal of forty-three eligible questionnaires were collected. All responders come from affiliated hospitals of medical schools in China. Each of these hospitals admitted more than one hundred patients with aneurysmal subarachnoid hemorrhage per year. Only 9.3% (4/43) of responders disagree with the prophylactic use of anticonvulsants. 86.04% (37/43) of responders perform seizure prophylaxis in clinical practice. Sodium valproate is the most commonly used regimen; 94.59% (35/37) of responders who perform prophylaxis chose this drug. The medication period differs sharply fromlessthan 3 daystolongerthan 14 daysamong different hospitals. The use of EEG was insufficient in Chinese patients. A low seizure rate was reported according to the feedback from Chinese neurosurgeons.In China, seizure prophylaxis after subarachnoid hemorrhage was not yet standardized. Clinicians' mastery of relevant knowledge is still not enough. Carrying out high-quality clinical research can help justify the use of anticonvulsants, which could also positively impact rational drug use.

[A randomized double-blinded placebo-controlled clinical trial of minodronate tablet in postmenopausal Chinese women with osteoporosis]

Objective: To verify the efficacy and safety of daily oral minodronate in postmenopausal women with established osteoporosis. Methods: In this randomized, double-blinded, placebo-controlled trial, 262 postmenopausal women were enrolled. Patients were randomized to receive daily oral minodronate 1 mg with supplements of 500 mg calcium and 200 U vitamin D₃ (n=130) or placebo (n=132) with daily supplements of 500 mg calcium and 200 U vitamin D₃, for 48 weeks. The primary endpoint was the average bone mineral density (BMD) change in the lumbar vertebrae 48 weeks post-treatment. Secondary outcome measures was the incidence of vertebral fractures. Safety assessments included the rate of adverse events. Results: At the end of 48 weeks treatment, the average BMD change rate from baseline were: full analysis set results: (3.52±4.82)% in the minodronate group and (2.00±5.74)% in the placebo group; per-protocol set results: (3.99±5.05)% in the minodronate group and (2.07±6.20)% in the placebo group; the differences were all significant (all P<0.05). Vertebral fracture occured in 3 patients (2.3%, 3/132) in the placebo group, and 1 case (0.8%, 1/130) in the minodronate group (P>0.05). The incidence of adverse events was 71.5% (93/130) in the minodronate group and 78.0% (103/132) in the placebo group (P>0.05). Conclusion: Minodronate is effective and safe in the treatment of postmenopausal osteoporosis without severe side effects.

Water-in-salt electrolytes achieve high energy densities at an ultralow-temperature for aqueous symmetrical supercapacitors

LiTFSI/H₂O water-in-salt electrolytes with different concentrations show high energy densities for capacitive charge storage at sub-zero-temperatures (e.g. 32.23, 38.35 and 35 W h kg^-1 at 0, -10 and -20 °C, which are 1.44, 1.71 and 1.56 times that of normal temperature).

[Establishment of a rapid risk assessment system for imported COVID-19 cases]

Objective: To develop a rapid risk assessment tool for imported COVID-19 cases and provide reference evidences for prevention and control of COVID-19 at ports. Methods: The information about COVID-19 pandemic and control strategies of 12 concerned countries was collected during July to August 2021, and 12 indexes were selected to assess the importation risk of COVID-19 by risk matrix. Results: The risk for imported COVID-19 cases from 12 countries to China was high or extremely high, and the risk from Russia and the USA was highest. Conclusions: The developed rapid risk assessment tool based on the risk matrix method can be used to determine the risk level of countries for imported COVID-19 cases to China at ports, and the risk of imported COVID-19 was high at Beijing port in August 2021.

A comparative study on the physicochemical properties, reactivity and long-term performance of sulfidized nanoscale zerovalent iron synthesized with different kinds of sulfur precursors and procedures in simulated groundwater

There are plentiful ways to synthesize sulfidized nanoscale zerovalent iron (S-nZVI), and this study investigated the influence of sulfur reagents (Na₂S, Na₂S₂O₃, Na₂S₂O₄) and sulfidation sequence (co-sulfidation and post-sulfidation method) on the physicochemical properties, reactivity, and long-term performance of S-nZVI in simulated groundwater. The results suggested that the co-sulfidized nZVI (S-nZVI_co) has higher reactivity (∼2-fold) than S-nZVI_post due to the stronger electron transfer capacity, deriving from the higher content of Fe⁰ and reductive sulfur species. However, during aging, the reactivity of S-nZVI_co would be lost more rapidly than S-nZVI_post, due to the faster corrosion of Fe⁰ and more oxidation of reductive sulfur species. S-nZVI_post has the superior long-term performance with the degradation rate of trichloroethylene (TCE) remained at 30%∼60% even after 90 d of aging. Sulfur precursors can control the selectivity of S-nZVI by affecting the sulfur speciation on the particle surface. The proportion of reductive sulfur species on S-nZVI_post synthesized by Na₂S was higher than S-nZVI_post synthesized by Na₂S₂O₃ or Na₂S₂O₄, resulting in a higher selectivity of the former S-nZVI_post than the latter S-nZVI_post. In addition, sulfidation procedures and sulfur precursors did not affect the degradation pathway of TCE. Nevertheless, the degradation product distribution can be affected by the different physicochemical transformation of various types of S-nZVI with the aging time. These results indicated that sulfur reagents and sulfidation procedures have crucial effects on the reactivity and long-term performance of S-nZVI, which can be designed for the specific application scenarios.

The MADS-domain factor AGAMOUS-Like18 promotes somatic embryogenesis

AGAMOUS-Like 18 (AGL18) is a MADS domain transcription factor (TF) that is structurally related to AGL15. Here we show that, like AGL15, AGL18 can promote somatic embryogenesis (SE) when ectopically expressed in Arabidopsis (Arabidopsis thaliana). Based on loss-of-function mutants, AGL15 and AGL18 have redundant functions in developmental processes such as SE. To understand the nature of this redundancy, we undertook a number of studies to look at the interaction between these factors. We studied the genome-wide direct targets of AGL18 to characterize its roles at the molecular level using chromatin immunoprecipitation (ChIP)-SEQ combined with RNA-SEQ. The results demonstrated that AGL18 binds to thousands of sites in the genome. Comparison of ChIP-SEQ data for AGL15 and AGL18 revealed substantial numbers of genes bound by both AGL15 and AGL18, but there were also differences. Gene ontology analysis revealed that target genes were enriched for seed, embryo, and reproductive development as well as hormone and stress responses. The results also demonstrated that AGL15 and AGL18 interact in a complex regulatory loop, where AGL15 inhibited transcript accumulation of AGL18, while AGL18 increased AGL15 transcript accumulation. Co-immunoprecipitation revealed an interaction between AGL18 and AGL15 in somatic embryo tissue. The binding and expression analyses revealed a complex crosstalk and interactions among embryo TFs and their target genes. In addition, our study also revealed that phosphorylation of AGL18 and AGL15 was crucial for the promotion of SE.

Evolution of Fertilization-Related Genes Provides Insights Into Reproductive Health in Natural Ascrotal Mammals

Cryptorchidism is the failure of one or both testes to descend into the bottom of the scrotum. This common congenital malformation in humans and domestic animals is the best characterized risk factor for abnormal sperm functions and infertility. However, current treatment approaches for cryptorchidism do not ensure paternity in all cases. Some lineages of mammals (such as elephants and cetaceans) have natural ascrotal testes (i.e., undescended or incompletely descended testes) and normal sperm motility and fertility, providing an opportunity to understand the genetic basis of cryptorchidism. In this study, we showed that genes associated with sperm motility and competition/fertility in ascrotal mammals experienced frequent, strong selective pressure. The fixation of specific amino acids and positive selection in ascrotal mammals could affect the physicochemical properties and functions of fertilization-related proteins. In a comparison between mammals with undescended testes and incompletely descended testes, discrepancies in genes showing evidence for adaptive evolution and in functional enrichment suggested that multiple molecular mechanisms contribute to the maintenance of fertility in the challenging testicular environment. Our findings revealed substantial heterogeneity in the divergence of fertilization-related genes between natural scrotal and ascrotal mammals and provide insight into molecular mechanisms underlying normal sperm motility and competition in natural ascrotal mammals. We provide a detailed theoretical basis for understanding the pathology of cryptorchidism from a molecular evolutionary perspective. This study may contribute to the establishment of diagnostic and therapeutic targets for sperm motility and fertility disorders due to congenital cryptorchidism in humans and domestic animals.