Genetic basis of I-complex plasmid stability and conjugation.

Plasmids are major drivers of increasing antibiotic resistance, necessitating an urgent need to understand their biology. Here we describe a detailed dissection of the molecular components controlling the genetics of I-complex plasmids, a group of antibiotic resistance plasmids found frequently in pathogenic Escherichia coli and other Enterobacteriaceae that cause significant human disease. We show these plasmids cluster into four distinct subgroups, with the prototype IncI1 plasmid R64 subgroup displaying low nucleotide sequence conservation to other I-complex plasmids. Using pMS7163B, an I-complex plasmid distantly related to R64, we performed a high-resolution transposon-based genetic screen and defined genes involved in replication, stability, and conjugative transfer. We identified the replicon and a partitioning system as essential for replication/stability. Genes required for conjugation included the type IV secretion system, relaxosome, and several uncharacterised genes located in the pMS7163B leading transfer region that exhibited an upstream strand-specific transposon insertion bias. The overexpression of these genes severely impacted host cell growth or reduced fitness during mixed competitive growth, demonstrating that their expression must be controlled to avoid deleterious impacts. These genes were present in >80% of all I-complex plasmids and broadly conserved across multiple plasmid incompatibility groups, implicating an important role in plasmid dissemination.

Enantioselective Construction of Anthracenylidene-Based Axial Chirality by Asymmetric Heck Reaction.

Anthracenylidene is an intriguing structural unit with potential in various fields. The study presents a novel approach to introducing axial chirality into this all-carbon core skeleton through a remotely controlled desymmetrization strategy. A palladium-catalyzed enantioselective Heck arylation of exocyclic double bond of anthracene with two distinct substituents at the C10 position is harnessed to realize such a transformation. The judicious identification of the P-centrally chiral ligand is pivotal to ensure the competitive competence in reactivity and stereocontrol when the heteroatom handle is absent from the anthracenylidene skeleton. Both C10 mono- and disubstituted substrates were compatible for the established catalytic system, and structurally diverse anthracenylidene-based frameworks were forged with good-to-high enantiocontrol. The subsequent derivatization of the obtained products yielded a valuable array of centrally and axially chiral molecules, thus emphasizing the practicality of this chemistry. DFT calculations shed light on the catalytic mechanism and provided insights into the origin of the experimentally observed enantioselectivity for this reaction.

Ferviditalea candida gen. nov., sp. nov., a novel member of the family Paenibacillaceae isolated from a geothermal area.

OBJECTIVE: The family Paenibacillaceae is linked to the order Caryophanales. Paenibacillaceae members residing in compost or soil play crucial roles in nutrient recycling and breaking down complex organic materials. However, our understanding of Paenibacillaceae remains limited. METHODS: Strain SYSU GA230002T was conclusively identified using a polyphasic taxonomic approach frequently utilized in bacterial systematics. Standard microbiological techniques were employed to characterize the morphology and biochemistry of strain SYSU GA230002T. RESULTS: An anaerobic and Gram-stain-negative bacterium, designated SYSU GA230002T, was isolated from geothermally heated soil of Tengchong, Yunnan Province, south-west China. Phylogenetic analyses based on 16S rRNA gene sequences and genomes showed that strain SYSU GA230002T belongs to the family Paenibacillaceae. 16S rRNA gene sequence similarity (<94.0%), ANI (<71.95%) and AAI values (<58.67%) between strain SYSU GA230002T with other members of the family were lower than the threshold values recommended for distinguishing novel species. Growth was observed at 30-45ºC (optimum, 37ºC), pH 7.0-8.0 (optimum, pH 7.5) and in 0-3.0% (w/v) NaCl concentrations (optimum, 0%). The major fatty acids detected were anteiso-C15:0, iso-C16:0 and iso-C17:0. The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified phospholipid, one unidentified aminolipid and two unidentified glycolipids. The respiratory quinone was MK-7. The DNA G+C content of strain SYSU GA230002T was 49.87%. CONCLUSION: Based on the results of morphological, physiological properties, and chemotaxonomic characteristics, this strain is proposed to represent a new species of a new genus Ferviditalea candida gen. nov., sp. nov. The type strain of the type species is SYSU GA230002T (=KCTC 25726T=GDMCC 1.4160T).

Clostridium caldaquaticum sp. nov., a thermophilic bacterium isolated from a hot spring sediment.

A novel anaerobic bacterium, designated SYSU GA19001T, was isolated from a hot spring sediment sample. Phylogenetic analysis indicated that the isolate belongs to the genus Clostridium, and showed the highest sequence similarity to Clostridium swellfunianum CICC 10730T (96.63 %) and Clostridium prolinivorans PYR-10T (96.11 %). Cells of strain SYSU GA19001T were Gram-stain-positive, spore-forming, rod-shaped (0.6-0.8×2.6-4.0 µm) and motile. Growth was observed at pH 5.0-9.0 (optimum, pH 7.0), 37-55 °C (optimum, 45 °C) and in NaCl concentrations of 0-2.0 % (optimum, 0 %). The genomic DNA G+C content was 31.62 %. The major cellular fatty acids of strain SYSU GA19001T were C14 : 0, iso-C15 : 0, C16 : 0 and summed feature 8. The prominent polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol. Meso-diaminopimelic acid was the diamino acid in peptidoglycan. Based on the results of phylogenetic, chemotaxonomic and phenotypic analyses, strain SYSU GA19001T represents a novel species of the genus Clostridium, for which the name Clostridium caldaquaticum sp. nov. is proposed. The type strain of the proposed novel species is SYSU GA19001T (=NBRC 115040T= CGMCC 1.17864T).

Association between polymorphisms in connexin 40 gene (Cx40) and risk of atrial fibrillation: a meta-analysis based on 3,452 subjects.

INTRODUCTION: Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with heart failure and stroke, leading sometimes to death. But the pathogenesis of AF remains unclear. Numerous studies have investigated whether the connexin 40 (Cx40) polymorphisms influences the risk of AF, but the results are controversial. METHODS: We searched English and Chinese databases and calculated the odds ratio (OR) and 95% confidence interval (CI) to examine the existence of genetic associations between the Cx40 polymorphisms and the risk of AF. All relevant studies were screened and meta-analyzed using Review Manager 5.0. RESULTS: A total of 12 studies, including 10 studies for -44 polymorphism (rs35594137) and 4 studies for -26 polymorphism (rs10465885), were identified for the meta-analysis. For -44 polymorphism, the results showed a significantly increased risk of AF in the five genetic models in the overall analysis. Furthermore, in subgroup analysis, increased AF risks were also observed in Asian and non-Asian populations. For -26 polymorphism, the overall OR revealed an increased risk of AF in dominant model. In subgroup analysis, increased AF risk was only found in recessive genetic model of the Asian population. CONCLUSIONS: The Cx40 polymorphisms were positively associated with AF in both populations, especially on -44 polymorphism.

Dual ligand-induced photoelectrochemical sensing by integrating Pt/MoS2 heterostructure and Au polyhedra for sensitive detection of SARS-CoV-2.

The continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with discovery of multiple mutants, has caused widespread panic and concern worldwide. The rapid antigen detection method via a single ligand recognition, although currently implemented in many countries, remains challenging for mutated antigens. Herein, we present a novel strategy using a dual recognition by two types of targeted ligands, based on photoelectrochemical (PEC) sensing for detection of SARS-CoV-2 spike protein. To demonstrate this strategy, the specific antibodies are modified onto the photoactive material with a supported nanostructure, created by loading the Pt nanoparticles onto MoS2 nanosheets (Pt/MoS2) to boost photon-to-electricity conversion efficiency. By subsequent binding of the targeted aptamers to the Au polyhedra, which act as a signal amplifier to suppress PEC photocurrent by competing with the Pt/MoS2 for the absorption of excitation light energy, the dual recognition is successfully achieved. The constructed biosensor not only shows satisfactory stability, high sensitivity, and selectivity, but is effective for test of the pseudovirus of SARS-CoV-2. The work provides useful advance for the development of PEC biosensors for sensitive detection of SARS-CoV-2.

The Signal Characteristics of Oil and Gas Pipeline Leakage Detection Based on Magneto-Mechanical Effects.

In order to solve the problem of the quantification of detection signals in the magnetic flux leakage (MFL) of defective in-service oil and gas pipelines, a non-uniform magnetic charge model was established based on magnetic effects. The distribution patterns of magnetic charges under different stresses were analyzed. The influences of the elastic load and plastic deformation on the characteristic values of MFL signals were quantitatively assessed. The experimental results showed that the magnetic charge density was large at the edges of the defect and small at the center, and approximately decreased linearly with increasing stress. The eigenvalues of the axial and radial components of the MFL signals were compared, and it was found that the eigenvalues of the radial component exhibited a larger decline rate and were more sensitive to stress. With the increase in the plastic deformation, the characteristic values of the MFL signals initially decreased and then increased, and there was an inflection point. The location of the inflection point was associated with the magnetostriction coefficient. Compared with the uniform magnetic charge model, the accuracy of the axial and radial components of the MFL signals in the elastic stage of the improved magnetic charge model rose by 17% and 16%, respectively. The accuracy of the axial and radial components of the MFL signals were elevated by 9.15% and 9%, respectively, in the plastic stage.

Fault Diagnosis for Complex Equipment Based on Belief Rule Base with Adaptive Nonlinear Membership Function.

Fault diagnosis of complex equipment has become a hot field in recent years. Due to excellent uncertainty processing capability and small sample problem modeling capability, belief rule base (BRB) has been widely used in the fault diagnosis. However, previous BRB models almost did not consider the diverse distributions of observation data which may reduce diagnostic accuracy. In this paper, a new fault diagnosis model based on BRB is proposed. Considering that the previous triangular membership function cannot address the diverse distribution of observation data, a new nonlinear membership function is proposed to transform the input information. Then, since the model parameters initially determined by experts are inaccurate, a new parameter optimization model with the parameters of the nonlinear membership function is proposed and driven by the gradient descent method to prevent the expert knowledge from being destroyed. A fault diagnosis case of laser gyro is used to verify the validity of the proposed model. In the case study, the diagnosis accuracy of the new BRB-based fault diagnosis model reached 95.56%, which shows better fault diagnosis performance than other methods.

Thermomonas flagellata sp. nov. and Thermomonas alba sp. nov., two novel members of the phylum Pseudomonadota isolated from hot spring sediments.

Two novel species, designated strains SYSU G04041T and SYSU G04536T, were isolated from hot spring sediments collected in Yunnan, PR China. Phenotypic and chemotaxonomic analyses, and whole-genome sequencing were used to determine the taxonomic positions of the candidate strains. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain SYSU G04041T showed the highest sequence similarity to Thermomonas haemolytica A50-7-3T (97.5 %), and SYSU G04536T showed the highest sequence similarity to Thermomonas hydrothermalis SGM-6T (98.2 %). The strains could be differentiated from other species of the genus Thermomonas by their distinct phenotypic and genotypic characteristics. Cells of strains SYSU G04041T and SYSU G04536T were aerobic, motile and Gram-stain-negative. Growth both occurred optimally at 45 °C and pH 7.0 for SYSU G04041T and SYSU G04536T. In addition, the predominant respiratory quinone in both isolates was ubiquinone Q-8. The major fatty acids (>10 %) of strain SYSU G04041T were C16 : 0, iso-C15 : 0 and iso-C16 : 0, while the major fatty acids (>10 %) of strain SYSU G04536T were iso-C15 : 0 and iso-C16 : 0. The main detected polar lipids in strains SYSU G04041T and SYSU G04536T included phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The G+C contents of the genomic DNA of strains SYSU G04041T and SYSU G04536T based on draft genomic sequences were 72.5 and 68.3 %, respectively. On the basis of phenotypic, genotypic and phylogenetic data, strains SYSU G04041T and SYSU G04536T represent two novel species of the genus Thermomonas, for which the names Thermomonas flagellata sp. nov. and Thermomonas alba sp. nov. are proposed, with the type strains SYSU G04041T (=CGMCC 1.19366T=KCTC 92228T) and SYSU G04536T (=CGMCC 1.19367T=KCTC 82839T), respectively.

Mechanism and Kinetic Study of Cyclodextrin Use to Facilitate NO2 Absorption in Sulfite Solutions.

An innovative strategy to control nitrogen oxide emission from flue gas was developed using the wet flue gas denitrification technology. The use of cyclodextrin (CD) as an additive facilitated NO2 absorption by the sulfite absorbent. Compared with absorption by a sulfite solution (59.12%), the instantaneous absorption efficiencies employing CD improved to 94.57%. Moreover, 48 h of continuous absorption indicated cyclic utilization of CD. The favorable role of CD was ascribed to facilitating the limiting step for the entire NO2 absorption-dissolution process which included both water solubility and gas-liquid mass transfer. Furthermore, we propose a potential mechanism of CD/sulfite mixed solution absorbing NO2, among which the favorable role of the additive is related to its amphiphilic behavior toward gas and liquid phases. Additionally, a kinetic model describing the rates of gas-liquid transfer and macro absorption was established based on various operating conditions. This model explains the absorption improvement in the kinetic aspect and provides theoretical guidance for practical applications.

Rhodoflexus caldus gen. nov., sp. nov., a new member of the phylum Bacteroidota isolated from a hot spring sediment.

A thermophilic bacterium, designated strain SYSU G04325T, was isolated from a hot spring sediment in Yunnan, China. Polyphasic taxonomic analyses and whole-genome sequencing were used to determine the taxonomic position of the strain. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain SYSU G04325T shows high sequence similarity to Thermoflexibacter ruber NBRC 16677T (86.2%). The strain can be differentiated from other species of the family Thermoflexibacteraceae by its distinct phenotypic and genotypic characteristics. Cells of the strain SYSU G04325T were observed to be aerobic, Gram-stain negative and filamentous. Growth was found to occur optimally at 45 ºC and pH 7.0. In addition, the respiratory quinone was identified as menaquinone-7, while the major fatty acids (> 10%) were identified as iso-C15:0, iso-C17:0 and Summed Feature 9 (iso-C17:1ω9c). The polar lipids detected included phosphatidylethanolamine, three unidentified phospholipids, one unidentified glycolipid, five unidentified aminolipids and four unidentified polar lipids. The G + C content of the genomic DNA was determined to be 47.6% based on the draft genome sequence. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU G04325T is concluded to represent a novel species of a novel genus in the family Thermoflexibacteraceae, for which the name Rhodoflexus caldus gen. nov., sp. nov. is proposed. The type strain of Rhodoflexus caldus is SYSU G04325T (= MCCC 1K06127T = KCTC 82848T).

Genome-based reclassification of the genus Meiothermus along with the proposal of a new genus Allomeiothermus gen. nov.

Phylogenomic analyses were performed on the nine species of the genus Meiothermus and four species of the genus Calidithermus. Phylogenetic analysis, low values of genomic relatedness indices and functional diversity analysis indicated that Meiothermus silvanus should not be classified within the clades for Meiothermus and Calidithermus but instead be reclassified as a new genus, for which we propose the name Allomeiothermus gen. nov., with Allomeiothermus silvanus comb. nov. as type species. In addition, the species Meiothermus cateniformans Zhang et al. (Int J Syst Evol Microbial 60:840-844, 2010) should also be reclassified as a later heterotypic synonym of Meiothermus taiwanensis Chen et al. (Int J Syst Evol Microbiol 52:1647-1654, 2002) emend. Raposo et al. (2019). This reclassification is based on the high genomic relatedness indices (98.8% ANI; 90.2% dDDH; 99% AAI) that are above the threshold values necessary for defining a new species, as well as on the observation of overlapping functions on Principal Coordinate Analysis plot generated from Clusters of Orthologous Genes.

Tumor-Microenvironment-Responsive Cascade Reactions by a Cobalt-Single-Atom Nanozyme for Synergistic Nanocatalytic Chemotherapy.

Nanocatalytic therapy, involving the nanozyme-triggered production of reactive oxygen species (ROS) in the tumor microenvironment (TME), has demonstrated potential in tumor therapy, but nanozymes still face challenges of activity and specificity that compromise the therapeutic efficacy. Herein, we report a strategy based on a single-atom nanozyme to initiate cascade enzymatic reactions in the TME for tumor-specific treatment. The cobalt-single-atom nanozyme, with Co-N coordination on N-doped porous carbon (Co-SAs@NC), displays catalase-like activity that decomposes cellular endogenous H2 O2 to produce O2 , and subsequent oxidase-like activity that converts O2 into cytotoxic superoxide radicals to efficiently kill tumor cells. By incorporation with doxorubicin, the therapy achieves a significantly enhanced antitumor effect in vivo. Our findings show that cascade TME-specific catalytic therapy combined with chemotherapy is a promising strategy for efficient tumor therapy.

Alteribacter salitolerans sp. nov., isolated from a saline-alkaline soil.

A Gram-positive strain APA H-16(1)T was isolated from a saline-alkali soil sample collected from Heilongjiang Province, China. Cells were rod shaped, non-motile, endospore forming, and aerobic. Growth occurred at 10-45 °C (optimum, 35 °C), pH 7.0-10.5 (optimum, pH 9.5), and could tolerate NaCl up to 15.0% (w/v). Strain showed low 16S rRNA gene sequence similarities with Alteribacter natronophilus (97.8%), Alteribacter aurantiacus (97.7%), and Alteribacter populi (97.1%). The cell wall peptidoglycan was meso-diaminopimelic acid. The predominant menaquinone was MK-7. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified aminophospholipids, unidentified phospholipid, and unidentified lipid. The major fatty acids were anteiso-C15:0, and iso-C15:0. The genomic G + C content was 45.1%. The average nucleotide identity and digital DNA-DNA hybridization values between strain APA H-16(1)T and the most closely related species were below the cut-off level (95-96%; 70%) for species delineation. Based on phenotypic, phylogenetic, chemotaxonomic, and genome comparison, strain APA H-16(1)T represents a novel species of the genus Alteribacter, for which the name Alteribacter salitolerans sp. nov. is proposed. The type strain is APA H-16(1)T (= KCTC 43228T = CICC 25092T).

Cytosolic DNA sensor cGAS plays an essential pathogenetic role in pressure overload-induced heart failure.

Growing evidence shows that activation of inflammation in the heart provokes left ventricular (LV) remodeling and dysfunction in humans and experimental animals with heart failure (HF). Moreover, recent studies found that cyclic GMP-AMP synthase (cGAS), serving as a cytosolic DNA sensor, was essential for activating innate immunity against infection and cellular damage by initiating the STING-IRFs-type I IFN signaling cascade, which played important roles in regulating the inflammatory response. However, the pathophysiological role of cGAS in pressure overload-induced HF is unclear. Wild-type C57BL/6J mice and cGAS inhibition mice were subjected to transverse aortic constriction (TAC) to induce HF or sham operation. Inhibition of cGAS in the murine heart was performed using adeno-associated virus 9 (AAV9). Alterations of the cGAS/STING pathway were examined by qPCR and Western blotting. Cardiac remodeling was assessed by echocardiography as well as histological and molecular phenotyping. Compared with sham-operated mice, the cGAS/STING pathway was activated in LV tissues in TAC mice. Whereas TAC mice exhibited significant pathological cardiac remodeling and LV dysfunction, inhibition of cGAS improved early survival rates after TAC, preserved LV contractile function, and blunted pathological remodeling, including cardiac hypertrophy, fibrosis, and apoptosis. Furthermore, downregulation of cGAS diminished early inflammatory cell infiltration and inflammatory cytokine expression in response to TAC. These results demonstrated that cGAS played an essential pathogenetic role in pressure overload-induced HF to promote pathological cardiac remodeling and dysfunction. Our results suggest that inhibition of cGAS may be a novel therapeutic approach for HF.NEW & NOTEWORTHY In this study, we first revealed a novel role of cGAS in the regulation of pathological cardiac remodeling and dysfunction upon pressure overload. We found that the cGAS/STING pathway was activated during pressure overload. Moreover, we also demonstrated that inhibition of the cGAS/STING pathway alleviated pathological cardiac remodeling and downregulated the early inflammatory response during pressure overload-induced HF. Together, these findings will provide a new therapeutic target for HF.

Microfluidic formation of highly monodispersed multiple cored droplets using needle-based system in parallel mode.

Scale-up in droplet microfluidics achieved by increasing the number of devices running in parallel or increasing the droplet makers in the same device can compromise the narrow droplet-size distribution, or requires high fabrication cost, when glass- or polymer-based microdevices are used. This paper reports a novel way using parallelization of needle-based microfluidic systems to form highly monodispersed droplets with enhanced production rates yet in cost-effective way, even when forming higher order emulsions with complex inner structure. Parallelization of multiple needle-based devices could be realized by applying commercially available two-way connecters and 3D-printed four-way connectors. The production rates of droplets could be enhanced around fourfold (over 660 droplets/min) to eightfold (over 1300 droplets/min) by two-way connecters and four-way connectors, respectively, for the production of the same kind of droplets than a single droplet maker (160 droplets/min). Additionally, parallelization of four-needle sets with each needle specification ranging from 34G to 20G allows for simultaneous generation of four groups of PDMS microdroplets with each group having distinct size yet high monodispersity (CV < 3%). Up to six cores can be encapsulated in double emulsion using two parallelly connected devices via tuning the capillary number of middle phase in a range of 1.31 × 10-4 to 4.64 × 10-4 . This study leads to enhanced production yields of droplets and enables the formation of groups of droplets simultaneously to meet extensive needs of biomedical and environmental applications, such as microcapsules with variable dosages for drug delivery or drug screening, or microcapsules with wide range of absorbent loadings for water treatment.

Efficacy and safety of catheter-based renal denervation for heart failure with reduced ejection fraction: a systematic review and meta-analysis.

PURPOSE: To perform a comprehensive meta-analysis of all available evidence on the efficacy and safety of catheter-based renal denervation for heart failure with reduced ejection fraction. METHODS: We searched English and Chinese databases and calculated the weighted mean difference or standardized mean difference and 95% confidence intervals to estimate the efficacy and safety of renal denervation for heart failure. All relevant studies were screened and a meta-analysis was conducted using Review Manager 5.4. RESULTS: A total of 11 studies were identified for the meta-analysis. For the primary outcomes, the results showed that renal denervation significantly improved ejection fraction (weighted mean difference 6.42), left ventricular end-systolic diameter (weighted mean difference -3.95), left ventricular end-diastolic diameter (weighted mean difference -4.17) and left atrial diameter (weighted mean difference -4.09). For the secondary outcomes, renal denervation reduced the B-type natriuretic peptide level, heart rate, systolic blood pressure and diastolic blood pressure. However, further analysis revealed that renal denervation improved heart function but did not further reduce the heart rate and blood pressure compared with the control group. CONCLUSION: Treatment with renal denervation can significantly improve heart function and structure in patients with heart failure. In addition, the level of B-type natriuretic peptide can be reduced after renal denervation treatment. Renal denervation did not further reduce heart rate and blood pressure compared with the control group. Therefore, the treatment of heart failure with renal denervation is effective and safe.

Oestrogenic Endocrine Disruptors in the Placenta and the Fetus.

Endocrine disrupting chemicals (EDCs) are exogenous substances that interfere with the stability and regulation of the endocrine system of the body or its offspring. These substances are generally stable in chemical properties, not easy to be biodegraded, and can be enriched in organisms. In the past half century, EDCs have gradually entered the food chain, and these substances have been frequently found in maternal blood. Perinatal maternal hormone levels are unstable and vulnerable to EDCs. Some EDCs can affect embryonic development through the blood-fetal barrier and cause damage to the neuroendocrine system, liver function, and genital development. Some also effect cross-generational inheritance through epigenetic mechanisms. This article mainly elaborates the mechanism and detection methods of estrogenic endocrine disruptors, such as bisphenol A (BPA), organochlorine pesticides (OCPs), diethylstilbestrol (DES) and phthalates (PAEs), and their effects on placenta and fetal health in order to raise concerns about the proper use of products containing EDCs during pregnancy and provide a reference for human health.

Lymphatic system identification, pathophysiology and therapy in the cardiovascular diseases.

The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the closed, high-pressure and circular blood vascular circulation, the lymphatic system forms an open, low-pressure and unidirectional transit network from the extracellular space to the venous system. It plays a key role in regulating tissue fluid homeostasis, absorption of gastrointestinal lipids, and immune surveillance throughout the body. Despite the critical physiological functions of the lymphatic system, a complete understanding of the lymphatic vessels lags far behind that of the blood vasculatures due to the challenge of their visualization. During the last 20 years, discoveries of underlying genes responsible for lymphatic vessel biology, combined with state-of-the-art lymphatic function imaging and quantification techniques, have established the importance of the lymphatic vasculature in the pathogenesis of cardiovascular diseases including lymphedema, obesity and metabolic diseases, dyslipidemia, hypertension, inflammation, atherosclerosis and myocardial infraction. In this review, we highlight the most recent advances in the field of lymphatic vessel biology, with an emphasis on the new identification techniques of lymphatic system, pathophysiological mechanisms of atherosclerosis and myocardial infarction, and new therapeutic perspectives of lymphangiogenesis.

In-vitro differentiation of early pig spermatogenic cells to haploid germ cells.

Spermatogonial stem cells (SSCs) self-renew and contribute genetic information to the next generation. Pig is wildly used as a model animal for understanding reproduction mechanisms of human being. Inducing directional differentiation of porcine SSCs may be an important strategy in exploring the mechanisms of spermatogenesis and developing better treatment methods for male infertility. Here, we established an in-vitro culture model for porcine small seminiferous tubule segments, to induce SSCs to differentiate into single-tail haploid spermatozoa. The culture model subsequently enabled spermatozoa to express the sperm-specific protein acrosin and oocytes to develop to blastocyst stage after round spermatid injection. The addition of retinoic acid (RA) to the differentiation media promoted the efficiency of haploid differentiation. RT-PCR analysis indicated that RA stimulated the expression of Stra8 but reduced the expression of NANOS2 in spermatogonia. Genes involved in post-meiotic development, transition protein 1 (Tnp1) and protamine 1 (Prm1) were upregulated in the presence of RA. The addition of an RA receptor (RAR) inhibitor, BMS439, showed that RA enhanced the expression of cAMP responsive-element binding protein through RAR and promoted the formation of round spermatids. We established an efficient culture system for in-vitro differentiation of pig SSCs. Our study represents a model for human testis disease and toxicology screening. Molecular regulators of SSC differentiation revealed in this study might provide a therapeutic strategy for male infertility.