Multidimensional profiling reveals GATA1-modulated stage-specific chromatin states and functional associations during human erythropoiesis.

Mammalian erythroid development can be divided into three stages: hematopoietic stem and progenitor cell (HSPC), erythroid progenitor (Ery-Pro), and erythroid precursor (Ery-Pre). However, the mechanisms by which the 3D genome changes to establish the stage-specific transcription programs that are critical for erythropoiesis remain unclear. Here, we analyze the chromatin landscape at multiple levels in defined populations from primary human erythroid culture. While compartments and topologically associating domains remain largely unchanged, ∼50% of H3K27Ac-marked enhancers are dynamic in HSPC versus Ery-Pre. The enhancer anchors of enhancer-promoter loops are enriched for occupancy of respective stage-specific transcription factors (TFs), indicating these TFs orchestrate the enhancer connectome rewiring. The master TF of erythropoiesis, GATA1, is found to occupy most erythroid gene promoters at the Ery-Pro stage, and mediate conspicuous local rewiring through acquiring binding at the distal regions in Ery-Pre, promoting productive erythroid transcription output. Knocking out GATA1 binding sites precisely abrogates local rewiring and corresponding gene expression. Interestingly, knocking down GATA1 can transiently revert the cell state to an earlier stage and prolong the window of progenitor state. This study reveals mechanistic insights underlying chromatin rearrangements during development by integrating multidimensional chromatin landscape analyses to associate with transcription output and cellular states.

Two functionally interchangeable Vps9 isoforms mediate pollen tube penetration of style.

Style penetration by pollen tubes is essential for reproductive success, a process requiring canonical Rab5s in Arabidopsis. However, functional loss of Arabidopsis Vps9a, the gene encoding for guanine nucleotide exchange factor (GEF) of Rab5s, did not affect male transmission, implying the presence of a compensation program or redundancy. By combining genetic, cytological, and molecular approaches, we report that Arabidopsis Vps9b is a pollen-preferential gene, redundantly mediating pollen tube penetration of style with Vps9a. Vps9b is functionally interchangeable with Vps9a, whose functional distinction results from distinct expression profiles. Functional loss of Vps9a and Vps9b results in the mis-targeting of Rab5-dependent tonoplast proteins, defective vacuolar biogenesis, disturbed distribution of post-Golgi vesicles, increased cellular turgor, cytosolic acidification, and disrupted organization of actin microfilaments (MF) in pollen tubes, which collectively lead to the failure of pollen tubes to grow through style.

Canonical Rab5 GTPases are essential for pollen tube growth through style in Arabidopsis.

Pollen tubes have dynamic tubular vacuoles. Functional loss of AP-3, a regulator of one vacuolar trafficking route, reduces pollen tube growth. However, the role of canonical Rab5 GTPases that are responsible for two other vacuolar trafficking routes in Arabidopsis pollen tubes is obscure. By using genomic editing, confocal microscopy, pollen tube growth assays, and transmission electron microscopy, we demonstrate that functional loss of canonical Rab5s in Arabidopsis, RHA1 and ARA7, causes the failure of pollen tubes to grow through style and thus impairs male transmission. Functional loss of canonical Rab5s compromises vacuolar trafficking of tonoplast proteins, vacuolar biogenesis, and turgor regulation. However, rha1;ara7 pollen tubes are comparable to those of wild-type in growing through narrow passages by microfluidic assays. We demonstrate that functional loss of canonical Rab5s compromises endocytic and secretory trafficking at the plasma membrane (PM), whereas the targeting of PM-associated ATPases is largely unaffected. Despite that, rha1;ara7 pollen tubes contain a reduced cytosolic pH and disrupted actin microfilaments, correlating with the mis-targeting of vacuolar ATPases (VHA). These results imply a key role of vacuoles in maintaining cytoplasmic proton homeostasis and in pollen tube penetrative growth through style.

Pollen-specific gene SKU5-SIMILAR 13 enhances growth of pollen tubes in the transmitting tract in Arabidopsis.

Pollen tube growth and penetration in female tissues are essential for the transfer of sperm to the embryo sac during plant pollination. Despite its importance during pollination, little is known about the mechanisms that mediate pollen tube growth in female tissues. In this study, we identified an Arabidopsis thaliana pollen/pollen tube-specific gene, SKU5-SIMILAR 13 (SKS13), which was critical for the growth of pollen tubes in the transmitting tract. The SKS13 protein was distributed throughout the cytoplasm and pollen tube walls at the apical region. In comparison with wild-type pollen tubes, those of the sks13 mutants burst more frequently when grown in vitro. Additionally, the growth of sks13 pollen tubes was retarded in the transmitting tract, thereby resulting in decreased male fertility. The accumulation of pectin and cellulose in the cell wall of sks13 pollen tubes was altered, and the content of jasmonic acid (JA) in sks13 pollen was reduced. The pollen tubes treated with an inhibitor of JA biosynthesis grew much more slowly and had an altered distribution of pectin, which is similar to the pollen tube phenotypes of the SKS13 mutation. Our results suggest that SKS13 is essential for pollen tube growth in the transmitting tract by mediating the biosynthesis of JA that modifies the components of pollen tube cell walls.

Clinical characteristics of patients with 2019 coronavirus disease in a non-Wuhan area of Hubei Province, China: a retrospective study.

BACKGROUND: Since December 2019, the 2019 coronavirus disease (COVID-19) has expanded to cause a worldwide outbreak that more than 600,000 people infected and tens of thousands died. To date, the clinical characteristics of COVID-19 patients in the non-Wuhan areas of Hubei Province in China have not been described. METHODS: We retrospectively analyzed the clinical characteristics and treatment progress of 91 patients diagnosed with COVID-19 in Jingzhou Central Hospital. RESULTS: Of the 91 patients diagnosed with COVID-19, 30 cases (33.0%) were severe and two patients (2.2%) died. The severe disease group tended to be older (50.5 vs. 42.0 years; p = 0.049) and have more chronic disease (40% vs. 14.8%; p = 0.009) relative to mild disease group. Only 73.6% of the patients were quantitative polymerase chain reaction (qPCR)-positive on their first tests, while typical chest computed tomography images were obtained for each patient. The most common complaints were cough (n = 75; 82.4%), fever (n = 59; 64.8%), fatigue (n = 35; 38.5%), and diarrhea (n = 14; 15.4%). Non-respiratory injury was identified by elevated levels of aspartate aminotransferase (n = 18; 19.8%), creatinine (n = 5; 5.5%), and creatine kinase (n = 14; 15.4%) in laboratory tests. Twenty-eight cases (30.8%) suffered non-respiratory injury, including 50% of the critically ill patients and 21.3% of the mild patients. CONCLUSIONS: Overall, the mortality rate of patients in Jingzhou was lower than that of Wuhan. Importantly, we found liver, kidney, digestive tract, and heart injuries in COVID-19 cases besides respiratory problems. Combining chest computed tomography images with the qPCR analysis of throat swab samples can improve the accuracy of COVID-19 diagnosis.

The Arabidopsis KINßγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen.

Pollen-stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen-stigma interactions is poorly understood. KINßγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINßγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinßγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinßγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinßγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinßγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINßγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen-stigma interactions during pollination.

Protein palmitoylation is critical for the polar growth of root hairs in Arabidopsis.

BACKGROUND: Protein palmitoylation, which is critical for membrane association and subcellular targeting of many signaling proteins, is catalyzed mainly by protein S-acyl transferases (PATs). Only a few plant proteins have been experimentally verified to be subject to palmitoylation, such as ROP GTPases, calcineurin B like proteins (CBLs), and subunits of heterotrimeric G proteins. However, emerging evidence from palmitoyl proteomics hinted that protein palmitoylation as a post-translational modification might be widespread. Nonetheless, due to the large number of genes encoding PATs and the lack of consensus motifs for palmitoylation, progress on the roles of protein palmitoylation in plants has been slow. RESULTS: We combined pharmacological and genetic approaches to examine the role of protein palmitoylation in root hair growth. Multiple PATs from different endomembrane compartments may participate in root hair growth, among which the Golgi-localized PAT24/TIP GROWTH DEFECTIVE1 (TIP1) plays a major role while the tonoplast-localized PAT10 plays a secondary role in root hair growth. A specific inhibitor for protein palmitoylation, 2-bromopalmitate (2-BP), compromised root hair elongation and polarity. Using various probes specific for cellular processes, we demonstrated that 2-BP impaired the dynamic polymerization of actin microfilaments (MF), the asymmetric plasma membrane (PM) localization of phosphatidylinositol (4,5)-bisphosphate (PIP2), the dynamic distribution of RabA4b-positive post-Golgi secretion, and endocytic trafficking in root hairs. CONCLUSIONS: By combining pharmacological and genetic approaches and using root hairs as a model, we show that protein palmitoylation, regulated by protein S-acyl transferases at different endomembrane compartments such as the Golgi and the vacuole, is critical for the polar growth of root hairs in Arabidopsis. Inhibition of protein palmitoylation by 2-BP disturbed key intracellular activities in root hairs. Although some of these effects are likely indirect, the cytological data reported here will contribute to a deep understanding of protein palmitoylation during tip growth in plants.

Arabidopsis COBRA-LIKE 10, a GPI-anchored protein, mediates directional growth of pollen tubes.

Successful reproduction of flowering plants requires constant communication between female tissues and growing pollen tubes. Female cells secrete molecules and peptides as nutrients or guidance cues for fast and directional tube growth, which is executed by dynamic changes of intracellular activities within pollen tubes. Compared with the extensive interest in female cues and intracellular activities of pollen tubes, how female cues are sensed and interpreted intracellularly in pollen is poorly understood. We show here that COBL10, a glycosylphosphatidylinositol (GPI)-anchored protein, is one component of this pollen tube internal machinery. Mutations in COBL10 caused gametophytic male sterility due to reduced pollen tube growth and compromised directional sensing in the female transmitting tract. Deposition of the apical pectin cap and cellulose microfibrils was disrupted in cobl10 pollen tubes. Pollen tube localization of COBL10 at the apical plasma membrane is critical for its function and relies on proper GPI processing and its C-terminal hydrophobic residues. GPI-anchored proteins are widespread cell sensors in mammals, especially during egg-sperm communication. Our results that COBL10 is critical for directional growth of pollen tubes suggest that they play critical roles in cell-cell communications in plants.

HAPLESS13, the Arabidopsis µ1 adaptin, is essential for protein sorting at the trans-Golgi network/early endosome.

In plant cells, secretory and endocytic routes intersect at the trans-Golgi network (TGN)/early endosome (EE), where cargos are further sorted correctly and in a timely manner. Cargo sorting is essential for plant survival and therefore necessitates complex molecular machinery. Adaptor proteins (APs) play key roles in this process by recruiting coat proteins and selecting cargos for different vesicle carriers. The µ1 subunit of AP-1 in Arabidopsis (Arabidopsis thaliana) was recently identified at the TGN/EE and shown to be essential for cytokinesis. However, little was known about other cellular activities affected by mutations in AP-1 or the developmental consequences of such mutations. We report here that HAPLESS13 (HAP13), the Arabidopsis µ1 adaptin, is essential for protein sorting at the TGN/EE. Functional loss of HAP13 displayed pleiotropic developmental defects, some of which were suggestive of disrupted auxin signaling. Consistent with this, the asymmetric localization of PIN-FORMED2 (PIN2), an auxin transporter, was compromised in the mutant. In addition, cell morphogenesis was disrupted. We further demonstrate that HAP13 is critical for brefeldin A-sensitive but wortmannin-insensitive post-Golgi trafficking. Our results show that HAP13 is a key link in the sophisticated trafficking network in plant cells.

[Annual review of capillary electrophoresis technology in 2023].

This paper serves as an annual review of capillary electrophoresis (CE) technology for 2023. The journals were selected based on their impact factor (IF), a universally recognized academic performance metric, combined with experimental work closely related to CE technology, to facilitate the rapid acquisition of significant research and application advancements in CE technology in 2023. A thematic search of the ISI Web of Science database yielded 669 research papers on CE technology published in 2023. This review highlights five experimental papers published in journals with IFs greater than 10.0, including Nature Communications, Nucleic Acids Research, Engineering, Journal of Medical Virology, and Carbohydrate Polymers, and 31 experimental papers from representative journals with IFs between 5.0 and 10.0, such as Analytical Chemistry, Analytica Chimica Acta, Talanta, and Food Chemistry. It also provides an overview of experimental research in journals with focused reporting on CE technology but with IFs less than 5.0, such as Journal of Chromatography A and Electrophoresis, as well as significant experimental research from key domestic Chinese core journals (Peking University). In 2023, all the latest scientific advancements reported in journals with an IF greater than 10.0 utilized previously reported CE methods, offering new breakthroughs for the promotion and application of CE technology. Additionally, new applications of CE in conjunction with mass spectrometry remained a hot topic. An increase in reports on the hardware aspects of CE, such as 3D printing and underwater systems, and significant breakthroughs in the analysis of non-solution samples, such as solid particles, cell vesicles, cells, viruses, and bacteria, was noted. CE is advantageous for the analysis of drugs and their components. In Chinese journals, the number of papers on CE applications exceeded that in previous years, with particular focus on the field of printing for new applications.

The juxtamembrane and carboxy-terminal domains of Arabidopsis PRK2 are critical for ROP-induced growth in pollen tubes.

Polarized growth of pollen tubes is a critical step for successful reproduction in angiosperms and is controlled by ROP GTPases. Spatiotemporal activation of ROP (Rho GTPases of plants) necessitates a complex and sophisticated regulatory system, in which guanine nucleotide exchange factors (RopGEFs) are key components. It was previously shown that a leucine-rich repeat receptor-like kinase, Arabidopsis pollen receptor kinase 2 (AtPRK2), interacted with RopGEF12 for its membrane recruitment. However, the mechanisms underlying AtPRK2-mediated ROP activation in vivo are yet to be defined. It is reported here that over-expression of AtPRK2 induced tube bulging that was accompanied by the ectopic localization of ROP-GTP and the ectopic distribution of actin microfilaments. Tube depolarization was also induced by a potentially kinase-dead mutant, AtPRK2K366R, suggesting that the over-expression effect of AtPRK2 did not require its kinase activity. By contrast, deletions of non-catalytic domains in AtPRK2, i.e. the juxtamembrane (JM) and carboxy-terminal (CT) domains, abolished its ability to affect tube polarization. Notably, AtPRK2K366R retained the ability to interact with RopGEF12, whereas AtPRK2 truncations of these non-catalytic domains did not. Lastly, it has been shown that the JM and CT domains of AtPRK2 were not only critical for its interaction with RopGEF12 but also critical for its distribution at the plasma membrane. These results thus provide further insight into pollen receptor kinase-mediated ROP activation during pollen tube growth.

[Annual review of capillary electrophoresis technology in 2022].

This article provides a detailed review of capillary electrophoresis (CE) technology in 2022, summarizing a total of 881 CE technology-related articles searched from ISI Web of Science using the keywords "capillary electrophoresis mass spectrometry" or "capillary isoelectric focusing" or "micellar electrokinetic chromatography" or "capillary electrophoresis" (excluding "capillary electrochromatography""microchip" "microfluidic" "capillary monolithic column"). The review focuses on 16 articles published in Lancet Global Health, ACS Central Science, Microbiome, Trends in Food Science & Technology, TrAC-Trends in Analytical Chemistry, Journal of Pharmaceutical Analysis, Journal of Cachexia, Sarcopenia and Muscle, Food Hydrocolloids, Science of the Total Environment, and Carbohydrate Polymers with impact factors (IFs) greater than 10.0, and 46 articles published in Analytical Chemistry, Analytica Chimica Acta, Talanta, and Food Chemistry with IFs between 5.0 and 10.0. A comprehensive overview of representative CE works published in Journal of Chromatography A, Electrophoresis, and important Chinese core journals (Peking University) with IFs<5.0 is also provided. Based on IFs, this review introduces representative works on CE to facilitate readers' understanding of important research advances in CE technology over the last year.

Vesicle trafficking in Arabidopsis pollen tubes.

The delivery of sperm cells via tip-growing pollen tubes is an innovation of seed plants and shows the importance of pollen tubes for reproduction and their specific growth kinetics. Fast-growing pollen tubes demand an extensive and dynamic vesicular trafficking network to build new cell membrane and wall, to deliver proteins among endomembrane compartments, and also to respond to external stimuli for growth adjustment. In this review, we summarize current findings on endomembrane compartments and vesicular trafficking routes of pollen tubes, comparing and contrasting their features with those of most somatic cells. We discuss the importance of membrane homeostasis, either at the plasma membrane (PM) or between PM-targeted trafficking and vacuolar trafficking, for pollen tube growth. We also provide perspectives to facilitate future studies of vesicular trafficking in pollen tubes.

Arabidopsis AtVPS15 is essential for pollen development and germination through modulating phosphatidylinositol 3-phosphate formation.

Arabidopsis thaliana phosphatidylinositol 3-kinase (AtVPS34) functions in the development and germination of pollen by catalyzing the biosynthesis of phosphatidylinositol 3-phosphate (PI3P). In yeast, Vps15p is required for the membrane targeting and activity of Vps34. The expression of Arabidopsis thaliana VPS15 (AtVPS15), an ortholog of yeast Vps15, is mainly detected in pollen grains and pollen tubes. To determine its role in pollen development and pollen tube growth, we attempted to isolate the T-DNA insertion mutants of AtVPS15; however, homozygous lines of atvps15 were not obtained from the progeny of atvps15/+ heterozygotes. Genetic analysis revealed that the abnormal segregation is due to the failure of transmission of the atvps15 allele through pollen. Most pollen grains from the atvps15/+ genotype are viable, with normal exine structure and nuclei, but some mature pollen grains are characterized with unusual large vacuoles that are not observed in pollen grains from the wild AtVPS15 genotype. The germination ratio of pollen from the atvps15/+ genotype is about half when compared to that from the wild AtVPS15 genotype. When supplied with PI3P, in vitro pollen germination of the atvps15/+ genotype is greatly improved. Presumably, AtVPS15 functions in pollen development and germination by regulating PI3P biosynthesis in Arabidopsis.

4-Hydroxyphenyl Retinamide Preferentially Targets FLT3 Mutated Acute Myeloid Leukemia via ROS Induction and NF-κB Inhibition.

FMS-like tyrosine kinase 3 (FLT3) mutation is strongly associated with poor prognosis in acute myeloid leukemia (AML). Though many FLT3 inhibitors have been developed for clinical application with 34%-56% complete remission rate, patients would develop resistance sooner or later after initial response to tyrosine kinase inhibitors (TKIs), such as gilteritinib. And increasing studies have shown that several resistance related mutations of FLT3 emerged during the AML progression. Thus, further investigation is warranted for these FLT3mut AML patients to achieve a better treatment outcome. 4-Hydroxyphenyl retinamide (4-HPR) has been investigated extensively in animal models and clinical trials as an anticancer/chemopreventive agent and is currently used for protection against cancer development/recurrence, with minimal side effects. In this study, we performed gene-set enrichment analysis and found that down-regulated genes induced by 4-HPR were associated with FLT3-ITD gene sets. CD34+ AML stem/progenitor cells separated from 32 AML samples were treated with 4-HPR. Correlation analysis showed that AML cells with FLT3-ITD genetic alteration were more sensitive to 4-HPR treatment than those without FLT3-ITD. Next, we treated 22 primary AML cells with 4-HPR and found that 4-HPR was more toxic to AML cells with FLT3-ITD. These results indicated that 4-HPR was preferentially cytotoxic to all FLT3-ITD AML+ cells irrespective of stem/progenitor cells or blast cells. 4-HPR-induced reactive oxygen species (ROS) production and NF-κB inhibition might be the reason of 4-HPR selectivity on FLT3 mutated AML cells.

Associations of CXCL1 gene 5'UTR variations with ovarian cancer.

BACKGROUND: There are about 2.4 hundred thousand new cases and 1.5 hundred thousand deaths of ovarian cancer (OC) annually in the world. Chronic inflammation is a risk factor for OC. C-X-C motif chemokine ligand 1 (CXCL1) defects may facilitate inflammation and transactivate EGFR in ovarian cancer, but the precise haplotypes associated with the potential diseases remained largely unknown. In this work, we characterized CXCL1 gene variations to elucidate their possible associations with OC. METHODS: We analyzed the CXCL1 gene for 300 OC patients with 400 healthy participants as controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9). RESULTS: The variants rs11547681, rs201090116, rs199791199, rs181868085, rs4074 and rs1814092 within or near the CXCL1 gene were characterized. The genetic heterozygosity of rs11547681 and rs4074 was very high. Statistical analysis showed that the variant rs11547681 in the gene was closely associated with the risk of OC in the Chinese Han population, although this variant was not associated with FIGO stages or pathological grades of the patients. CONCLUSIONS: Rs11547681 in CXCL1 gene was associated with the risk of OC in the Chinese Han population.

Precocious leaf senescence by functional loss of PROTEIN S-ACYL TRANSFERASE14 involves the NPR1-dependent salicylic acid signaling.

We report here that Arabidopsis PROTEIN S-ACYL TRANSFERASE14 (PAT14), through its palmitate transferase activity, acts at the vacuolar trafficking route to repress salicylic acid (SA) signaling, thus mediating age-dependent but not carbon starvation-induced leaf senescence. Functional loss of PAT14 resulted in precocious leaf senescence and its transcriptomic analysis revealed that senescence was dependent on salicylic acid. Overexpressing PAT14 suppressed the expression of SA responsive genes. Introducing the SA deficient mutants, npr1-5 and NahG, but not other hormonal mutants, completely suppressed the precocious leaf senescence of PAT14 loss-of-function, further supporting the epistatic relation between PAT14 and the SA pathway. By confocal fluorescence microscopy, we showed that PAT14 is localized at the Golgi, the trans-Golg network/early endosome, and prevacuolar compartments, indicating its roles through vacuolar trafficking. By reporter analysis and real time PCRs, we showed that the expression PAT14, unlike most of the senescence associated genes, is not developmentally regulated, suggesting post-transcriptional regulatory mechanisms on its functionality. We further showed that the maize and wheat homologs of PAT14 fully rescued the precocious leaf senescence of pat14-2, demonstrating that the role of PAT14 in suppressing SA signaling during age-dependent leaf senescence is evolutionarily conserved between dicots and monocots.