Biallelic truncating TTN variants in M-band encoding exons cause a fetal lethal titinopathy.

To report two novel TTN variants associated with fetal recessive titinopathy, thereby broadening the range of TTN variants that can lead to titinopathy. Clinical information on the fetus and parents was gathered, and genomic DNAs were extracted from the fetal tissue and family members' peripheral blood samples. Exome sequencing on fetal DNA was performed and following bioinformatics analysis, the suspected pathogenic variants were confirmed through Sanger sequencing. Prenatal ultrasound performed at 29 weeks of gestation revealed hydrops fetalis, decreased fetal movements, multiple joint contractures and polyhydramnios. Intrauterine fetal death was noted in the third trimester. Exome sequencing revealed compound heterozygous variants in the TTN gene: a paternally inherited allele c.101227C>T (p.Arg33743Ter) and a maternally inherited c.104254C>T (p.Gln34752Ter) allele. These variants have not been previously reported and are evaluated to be likely pathogenic according to the American College of Medical Genetics and Genomics guidelines. We report a fetus with hydrops fetalis and arthrogryposis multiplex congenita associated with a compound heterozygote in the TTN gene. Our report broadens the clinical and genetic spectrum associated with the TTN-related conditions.

Spatial confinement of receptor activity by tyrosine phosphatase during directional cell migration.

Directional cell migration involves signaling cascades that stimulate actin assembly at the leading edge, and additional pathways must inhibit actin polymerization at the rear. During neuroblast migration in Caenorhabditis elegans, the transmembrane protein MIG-13/Lrp12 acts through the Arp2/3 nucleation-promoting factors WAVE and WASP to guide the anterior migration. Here we show that a tyrosine kinase, SRC-1, directly phosphorylates MIG-13 and promotes its activity on actin assembly at the leading edge. In GFP knockin animals, SRC-1 and MIG-13 distribute along the entire plasma membrane of migrating cells. We reveal that a receptor-like tyrosine phosphatase, PTP-3, maintains the F-actin polarity during neuroblast migration. Recombinant PTP-3 dephosphorylates SRC-1-dependent MIG-13 phosphorylation in vitro. Importantly, the endogenous PTP-3 accumulates at the rear of the migrating neuroblast, and its extracellular domain is essential for directional cell migration. We provide evidence that the asymmetrically localized tyrosine phosphatase PTP-3 spatially restricts MIG-13/Lrp12 receptor activity in migrating cells.

ANKRD49 promotes the invasion and metastasis of lung adenocarcinoma via a P38/ATF-2 signalling pathway.

Lung adenocarcinoma (LUAD) is the most challenging neoplasm to treat in clinical practice. Ankyrin repeat domain 49 protein (ANKRD49) is highly expressed in several carcinomas; however, its pattern of expression and role in LUAD are not known. Tissue microarrays, immunohistochemistry, χ2 test, Spearman correlation analysis, Kaplan-Meier, log-rank test, and Cox's proportional hazard model were used to analyse the clinical cases. The effect of ANKRD49 on the LUAD was investigated using CCK-8, clonal formation, would healing, transwell assays, and nude mice experiment. Expressions of ANKRD49 and its associated downstream protein molecules were verified by real-time PCR, Western blot, immunohistochemistry, and/or immunofluorescence analyses. ANKRD49 expression was highly elevated in LUAD. The survival rate and Cox's modelling analysis indicated that there may be an independent prognostic indicator for LUAD patients. We also found that ANKRD49 promoted the invasion and migration in both in in vitro and in vivo assays, through upregulating matrix metalloproteinase (MMP)-2 and MMP-9 activities via the P38/ATF-2 signalling pathway Our findings suggest that ANKRD49 is a latent biomarker for evaluating LUAD prognosis and promotes the metastasis of A549 cells via upregulation of MMP-2 and MMP-9 in a P38/ATF-2 pathway-dependent manner.

COVID-19 and inflammatory bowel disease crosstalk: From emerging association to clinical proposal.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause coronavirus disease 2019 (COVID-19), an acute respiratory inflammation that has emerged worldwide since December 2019, and it quickly became a global epidemic. Inflammatory bowel disease (IBD) is a group of chronic nonspecific intestinal inflammatory diseases whose etiology has not been elucidated. The two have many overlapping symptoms in clinical presentation, such as abdominal pain, diarrhea, pneumonia, etc. Imbalance of the autoimmune system in IBD patients and long-term use of immunosuppressive drugs may increase the risk of infection; and systemic symptoms caused by COVID-19 may also induce or exacerbate intestinal inflammation. It has been found that the SARS-CoV-2 receptor angiotensin converting enzyme 2, which is highly expressed in the lung and intestine, is an inflammatory protective factor, and is downregulated and upregulated in COVID-19 and IBD, respectively, suggesting that there may be a coregulatory pathway. In addition, the immune activation pattern of COVID-19 and the cytokine storm in the inflammatory response have similar roles in IBD, indicating that the two diseases may influence each other. Therefore, this review aimed to address the following research questions: whether SARS-CoV-2 infection leads to the progression of IBD; whether IBD increases the risk of COVID-19 infection and poor prognosis; possible common mechanisms and genetic cross-linking between the two diseases; new treatment and care strategies for IBD patients, and the feasibility and risk of vaccination in the context of the COVID-19 epidemic.

Effectiveness and safety of ultrasound-guided percutaneous microwave ablation for hepatic alveolar echinococcosis.

BACKGROUND: Microwave ablation (MWA) is a popular therapy for liver malignant tumor in recent years. Few studies have been conducted on its use in the treatment of hepatic alveolar echinococcosis (HAE). The study aims to evaluate the efficacy and safety of MWA in the treatment of HAE. METHODS: This study analyzed the data of 45 patients (mean age, 38 ± 2 years; 24 males) diagnosed with HAE and underwent MWA treatment between June 2014 to December 2019. The patients after MWA were examined by CT or MRI [follow-up: 32 months (IQR 23-48.5)] to determine whether the lesions were relapsed and to evaluate the therapeutic effect of MWA. The safety of MWA was evaluated by monitoring postoperative complications. Clinical data, such as patient demographics, imaging features of the lesions, relevant findings of laboratory tests before and after ablation, and information related to ablation, were collected and analyzed. Paired-sample t tests and paired-sample Wilcoxon signed-rank tests were used to compare relevant laboratory indicators before and after MWA. RESULTS: MWA was applied to 57 HAE lesions in 45 patients. The median size of lesions was 3.42 cm (IQR2.85-4.41). The rate of complete ablation was 100% (57/57). The median follow-up time was 32 months (IQR 23-48.5). The recurrence rate was 13% (6/45), and the median time of recurrence was 22 months. The rate of minor complications was 11.1% (5/45), and there were no major complications and deaths. Compared to preoperative, ALB, RBC, HBG, and PLT were decreased (p < 0.001); ALT, TB, DB, and WBC were increased (p < 0.001); and no statistically difference in PT, APTT, and INR (p > 0.05). CONCLUSIONS: MWA might be a safe and effective way to cure HAE. Meanwhile, it provides a new option and a new way of thinking about treatment for patients with HAE.

Crystal structure of the phosphorylated Arabidopsis MKK5 reveals activation mechanism of MAPK kinases.

The mitogen-activated protein kinase (MAPK) signaling pathways are highly conserved in eukaryotes, regulating various cellular processes. The MAPK kinases (MKKs) are dual specificity kinases, serving as convergence and divergence points of the tripartite MAPK cascades. Here, we investigate the biochemical characteristics and three-dimensional structure of MKK5 in Arabidopsis (AtMKK5). The recombinant full-length AtMKK5 is phosphorylated and can activate its physiological substrate AtMPK6. There is a conserved kinase interacting motif (KIM) at the N-terminus of AtMKK5, indispensable for specific recognition of AtMPK6. The kinase domain of AtMKK5 adopts active conformation, of which the extended activation segment is stabilized by the phosphorylated Ser221 and Thr215 residues. In line with sequence divergence from other MKKs, the αD and αK helices are missing in AtMKK5, suggesting that the AtMKK5 may adopt distinct modes of upstream kinase/substrate binding. Our data shed lights on the molecular mechanisms of MKK activation and substrate recognition, which may help design specific inhibitors targeting human and plant MKKs.

Phenoxypyridine derivatives containing natural product coumarins with allelopathy as novel and promising proporphyrin IX oxidase-inhibiting herbicides: Design, synthesis and biological activity study.

To seek novel and safe protoporphyrinogen oxidase (PPO, EC 1.3.3.4) inhibitors with excellent herbicidal activity. A series of novel phenoxypyridine derivatives containing natural product coumarins with allelopathy were designed and synthesized based on bioisosterism and active subunit combination in this research. Compounds W3.1 and W3.4, with the half-maximal inhibitory concentration (IC50) value of 0.02653 mg/L and 0.01937 mg/L, respectively, displayed excellent herbicidal activity in greenhouse. Their herbicidal activity was similar to commercial herbicide oxyfluorfen (IC50 = 0.04943 mg/L). The best field inhibitory effect of compounds W3.1 and W3.4 recorded was at doses of 450 g ai/ha and 300 g ai/ha, respectively. Compound W3.4 had the best herbicidal activity among all the target compounds in this paper. Molecular docking analysis revealed that compounds W3.1 and W3.4 could form a hydrogen bonds with the amino acid AGR-98 and a π-π superposition with the amino acid PHE-398, respectively, which was similar to the oxyfluorfen. The crop selectivity tests results indicated that maize, cotton and soybean showed high tolerance to compound W3.4. Compound W3.4 reduced the Ca and Cb contents of wheat and rice, but had less effect on maize, cotton and soybean. Selectivity of compound W3.4 in maize, cotton and soybean were appeared to be due to reduced absorption of the herbicide compared to wheat and rice. Compound W3.4 deserves further attention as a candidate structure for new herbicides.

Novel phenoxy-(trifluoromethyl)pyridine-2-pyrrolidinone-based inhibitors of protoporphyrinogen oxidase: Design, synthesis, and herbicidal activity.

As important chemical pesticides, protoporphyrinogen oxidase (PPO, EC 1.3.3.4) herbicides play a vital role in weed management. Herein, in a search for novel PPO herbicides, a series of phenoxypyridine-2-pyrrolidinone derivatives were synthesized and their herbicidal activities were tested. To confirm the structures of the newly synthesized compounds, a colorless single crystal of compound 9d was obtained and crystallographic data collected. PPO inhibition experiments showed that most compounds have PPO inhibitory effects. The half-maximal inhibitory concentration (IC50) of compound 9d and oxyfluorfen were 0.041 mg/L and 0.043 mg/L, respectively, which showed compound 9d was the most potent compound. Compound 9d reduced the Chlorophyll a (Chl a) and Chlorophyll b (Chl b) contents of Abutilon theophrasti (A. theophrasti), to 0.306 and 0.217 mg/g, respectively. Crop selectivity experiments and field trial indicated that compound 9d can potentially be used to develop post-emergence herbicides for weed control in rice, cotton, and peanut. Molecular docking studies showed that both oxyfluorfen and compound 9d can enter the PPO cavity to occupy the active site and compete with the porphyrin to block the chlorophyll synthesis process, affect photosynthesis, and eventually cause weed death. Compound 9d was found to be a promising lead compound for novel herbicide development.

Identification of a 4-miRNA signature as a potential prognostic biomarker for pancreatic adenocarcinoma.

An microRNA (miRNA) signature to predict the clinical outcome of pancreatic adenocarcinoma (PAAD) is still lacking. In the current study, we aimed at identifying and evaluating a prognostic miRNA signature for patients with PAAD. The miRNA expression profile and the clinical information regarding patients with PAAD were recruited from The Cancer Genome Atlas database. Differentially expressed miRNAs were identified between normal and tumor samples. By means of survival analysis, a 4-miRNA signature for predicting patients' with PAAD overall survival (OS) was constructed. Receiver operating characteristic (ROC) analysis was applied to determine the efficiency of survival prediction. Furthermore, the biological function of the predicted miRNAs was evaluated using a bioinformatics approach. Four (hsa-mir-126, hsa-mir-3613, hsa-mir-424, and hsa-mir-4772) out of 17 differentially expressed miRNAs were associated to the OS of patients with PAAD. Moreover, the area under the curve (AUC) of the constructed 4-miRNA signature associated to patients' with PAAD 2-year survival was 0.789. The multivariate Cox's proportional hazards regression model suggested that this 4-miRNA signature was an independent prognostic factor of other clinical parameters in patients with PAAD. Further pathway enrichment analyses revealed that the miRNAs in the 4-miRNA signature might regulate genes that affect focal adhesion, Wnt signaling pathway, and PI3K-Akt signaling pathway. Thus, these findings indicated that the 4-miRNA signature might be an effective independent prognostic biomarker in the prediction of PAAD patients' survival.

[The effect of high altitude on human color perception].

Exposure to a high altitude hypoxia environment has significant negative effects on human central nervous system. Many previous studies have explored the influence of the high altitude environment on human color perception in a simulated high altitude environment or in an environment acutely exposed to high altitude, but little has been done in migrators and natives exposed to high altitude and low oxygen for a long period of time. In this study, the minimal-change method was used to examine whether the color perception of red, green, blue and yellow was affected by the high altitude in 30 plain residents, 30 Han migrators who have lived in the high altitude for 2 years, and 28 high-altitude-adapted Tibetan natives. The results showed that long-term high altitude exposure had the most significant effect on the blue and red color perception in the natives and the migrators, with the effect on the blue color being significantly greater than that on the red color. However, the effects on green color processing only happened to the natives. The results suggest that there is an internal correlation between blood supply and selectivity changes of visual color processing caused by exposure to the plateau environment.

[Progress in goat genome studies].

The goat genome is the research basis for the protection and utilization of goat resources, which is important for breeding and improving goat breeds. At present, with the continuous improvement of goat reference genome, various important research progress in goat origin, evolution and adaptability has been achieved. In this review, we summarize the research progress in the goat genome in detail, encompassing goat genome structure, genome map (genetic, physical and comparative maps), goat high throughput sequencing and SNP chip development. We aim to provide a theoretical foundation for the development of goat genome selection.

Crystal structure of the kinase and UBA domains of SNRK reveals a distinct UBA binding mode in the AMPK family.

Sucrose non-fermenting (Snf1)-related kinase (SNRK) is a novel member of the AMP-activated protein kinase (AMPK) family and is involved in many metabolic processes. Here we report the crystal structure of an N-terminal SNRK fragment containing kinase and adjacent ubiquitin-associated (UBA) domains. This structure shows that the UBA domain binds between the N- and C-lobes of the kinase domain. The mode of UBA binding in SNRK largely resembles that in AMPK and brain specific kinase (BRSK), however, unique interactions play vital roles in stabilizing the KD-UBA interface of SNRK. We further propose a potential role of the UBA domain in the regulation of SNRK kinase activity. This study provides new insights into the structural diversities of the AMPK kinase family.

Structural and Dynamic Insights into the Mechanism of Allosteric Signal Transmission in ERK2-Mediated MKP3 Activation.

The mitogen-activated protein kinases (MAPKs) are key components of cellular signal transduction pathways, which are down-regulated by the MAPK phosphatases (MKPs). Catalytic activity of the MKPs is controlled both by their ability to recognize selective MAPKs and by allosteric activation upon binding to MAPK substrates. Here, we use a combination of experimental and computational techniques to elucidate the molecular mechanism for the ERK2-induced MKP3 activation. Mutational and kinetic study shows that the 334FNFM337 motif in the MKP3 catalytic domain is essential for MKP3-mediated ERK2 inactivation and is responsible for ERK2-mediated MKP3 activation. The long-term molecular dynamics (MD) simulations further reveal a complete dynamic process in which the catalytic domain of MKP3 gradually changes to a conformation that resembles an active MKP catalytic domain over the time scale of the simulation, providing a direct time-dependent observation of allosteric signal transmission in ERK2-induced MKP3 activation.

Quantitative Analysis of Ligand Induced Heterodimerization of Two Distinct Receptors.

The induced dimerization of two distinct receptors through a heterobifunctional inducer is prevalent among all levels of cellular signaling processes, yet its complexity poses difficulty for systematic quantitative analysis. This paper first shows how to calculate the amount of any possible complex or monomer of heteroligand and two receptors present at equilibrium. The theory is subsequently applied to the determination of three independent equilibrium parameters involved in the rapamycin induced FKBP and FRB dimerization, in which all parameters were simultaneously estimated using one set of fluorescence resonance energy transfer (FRET) experiments. A MATLAB script is provided for parametric fitting.

MAPK phosphatase 7 regulates T cell differentiation via inhibiting ERK-mediated IL-2 expression.

Members of the MAPK phosphatase (MKP) protein family play critical roles in immune responses through differential regulation of MAPK activation. In this study, we show that MKP7, also known as dual-specificity phosphatase 16, was required for CD4(+) T cell responses in vivo. Mkp7(-/-) CD4(+) T cells exhibited enhanced ERK and JNK activation, and produced increased amount of IL-2 compared with Mkp7(+/+) cells upon activation. Mkp7(-/-) CD4(+) T cells were selectively defective in Th17 differentiation in vitro, which was rescued by blocking IL-2 or inhibition of ERK activation. Furthermore, mice carrying Mkp7(-/-) T cells were deficient in generation of Th17 and T follicular helper cells in vivo, and were resistant to autoimmune experimental encephalomyelitis. Our results thus demonstrate an essential role of MKP7 in effector T cell function.

Structural basis for the Smad5 MH1 domain to recognize different DNA sequences.

Smad proteins are important intracellular mediators of TGF-ß signalling, which transmit signals directly from cell surface receptors to the nucleus. The MH1 domain of Smad plays a key role in DNA recognition. Two types of DNA sequence were identified as Smad binding motifs: the Smad binding element (SBE) and the GC-rich sequence. Here we report the first crystal structure of the Smad5 MH1 domain in complex with the GC-rich sequence. Compared with the Smad5-MH1/SBE complex structure, the Smad5 MH1 domain contacts the GC-rich site with the same ß-hairpin, but the detailed interaction modes are different. Conserved ß-hairpin residues make base specific contacts with the minimal GC-rich site, 5'-GGC-3'. The assembly of Smad5-MH1 on the GC-rich DNA also results in distinct DNA conformational changes. Moreover, the crystal structure of Smad5-MH1 in complex with a composite DNA sequence demonstrates that the MH1 domain is targeted to each binding site (GC-rich or SBE) with modular binding modes, and the length of the DNA spacer affects the MH1 assembly. In conclusion, our work provides the structural basis for the recognition and binding specificity of the Smad MH1 domain with the DNA targets.

[Research on Measurement Method of Gas Velocity Combined Absorption Spectroscopy Technique and Cross-Correlation].

For the small frequency shift and large error of tunable diode laser absorption spectroscopy (TDLAS) velocity method based on Doppler Effect in measuring the gas velocity, velocity measurement method combined fixed wavelength absorption spectroscopy and cross correlation is proposed in this paper. Considering the characteristics of the hydrocarbon fuel combustion products, 7 158.597 cm(- 1) absorption line of H(2)O molecular was selected. Through arranging two beams of fixed wavelength absorption measurement point of upstream and downstream, the gas velocity can be calculated by analyzing the cross-correlation properties of the two signals. The flat flame burner experiment system was used in the experimental research of the velocity measurement. The change of gas velocity with time under variable working condition was obtained. Under the same condition, numerical calculation is carried out. And the measurement results are compared with the results of the numerical simulation with relative deviation less than 8%. Then the method is preliminarily applied to measure the high speed plume of the kerosene-fueled Rocket Based Combined Cycle (RBCC) engine, and the upstream and downstream fluctuant signals of detectors were obtained. The velocity of the plume was calculated with cross correlation analysis which verifies the feasibility of this method. The experimental results show that the gas velocity measurement method has a wide measuring range with high measuring accuracy and little environment interference. The method proposed in this paper provides a simple and reliable method for the measurement of engine gas velocity.

Synthesis of N-(2-Hydroxyaryl)benzotriazoles via Metal-Free O-Arylation and N-O Bond Cleavage.

A metal-free method for synthesis of N-(2-hydroxyaryl)benzotriazoles via O-arylation of N-hydroxybenzotriazoles with readily available diaryliodonium salts and sequential N-O bond cleavage under mild conditions has been developed. The [3,3]-rearrangement of N-O bond cleavage could take place on the N instead of C atom. The reaction was compatible with diverse functional groups and a new type of P,N-ligand was synthesized in three steps.

Structure and inhibition analysis of the mouse SAD-B C-terminal fragment.

The SAD (synapses of amphids defective) kinases, including SAD-A and SAD-B, play important roles in the regulation of neuronal development, cell cycle, and energy metabolism. Our recent study of mouse SAD-A identified a unique autoinhibitory sequence (AIS), which binds at the junction of the kinase domain (KD) and the ubiquitin-associated (UBA) domain and exerts autoregulation in cooperation with UBA. Here, we report the crystal structure of the mouse SAD-B C-terminal fragment including the AIS and the kinase-associated domain 1 (KA1) at 2.8 Å resolution. The KA1 domain is structurally conserved, while the isolated AIS sequence is highly flexible and solvent-accessible. Our biochemical studies indicated that the SAD-B AIS exerts the same autoinhibitory role as that in SAD-A. We believe that the flexible isolated AIS sequence is readily available for interaction with KD-UBA and thus inhibits SAD-B activity.

Structural insight into the autoinhibition mechanism of AMP-activated protein kinase.

The AMP-activated protein kinase (AMPK) is characterized by its ability to bind to AMP, which enables it to adjust enzymatic activity by sensing the cellular energy status and maintain the balance between ATP production and consumption in eukaryotic cells. It also has important roles in the regulation of cell growth and proliferation, and in the establishment and maintenance of cell polarity. These important functions have rendered AMPK an important drug target for obesity, type 2 diabetes and cancer treatments. However, the regulatory mechanism of AMPK activity by AMP binding remains unsolved. Here we report the crystal structures of an unphosphorylated fragment of the AMPK alpha-subunit (KD-AID) from Schizosaccharomyces pombe that contains both the catalytic kinase domain and an autoinhibitory domain (AID), and of a phosphorylated kinase domain from Saccharomyces cerevisiae (Snf1-pKD). The AID binds, from the 'backside', to the hinge region of its kinase domain, forming contacts with both amino-terminal and carboxy-terminal lobes. Structural analyses indicate that AID binding might constrain the mobility of helix alphaC, hence resulting in an autoinhibited KD-AID with much lower kinase activity than that of the kinase domain alone. AMP activates AMPK both allosterically and by inhibiting dephosphorylation. Further in vitro kinetic studies demonstrate that disruption of the KD-AID interface reverses the autoinhibition and these AMPK heterotrimeric mutants no longer respond to the change in AMP concentration. The structural and biochemical data have shown the primary mechanism of AMPK autoinhibition and suggest a conformational switch model for AMPK activation by AMP.