ABSTRACT
Whereas the actions of enhancers in gene transcriptional regulation are well established, roles of JmjC-domain-containing proteins in mediating enhancer activation remain poorly understood. Here, we report that recruitment of the JmjC-domain-containing protein 6 (JMJD6) to estrogen receptor alpha (ERα)-bound active enhancers is required for RNA polymerase II recruitment and enhancer RNA production on enhancers, resulting in transcriptional pause release of cognate estrogen target genes. JMJD6 is found to interact with MED12 in the mediator complex to regulate its recruitment. Unexpectedly, JMJD6 is necessary for MED12 to interact with CARM1, which methylates MED12 at multiple arginine sites and regulates its chromatin binding. Consistent with its role in transcriptional activation, JMJD6 is required for estrogen/ERα-induced breast cancer cell growth and tumorigenesis. Our data have uncovered a critical regulator of estrogen/ERα-induced enhancer coding gene activation and breast cancer cell potency, providing a potential therapeutic target of ER-positive breast cancers.
Subject(s)
Breast Neoplasms/enzymology , Cell Proliferation , Estrogen Receptor alpha/metabolism , Jumonji Domain-Containing Histone Demethylases/metabolism , Mediator Complex/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Transcriptional Activation , Animals , Binding Sites , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Estradiol/pharmacology , Estrogen Receptor alpha/agonists , Estrogen Receptor alpha/genetics , Female , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Neoplastic , HEK293 Cells , Humans , Jumonji Domain-Containing Histone Demethylases/genetics , MCF-7 Cells , Mediator Complex/genetics , Mice, Inbred BALB C , Mice, Nude , Protein Binding , Protein Transport , Protein-Arginine N-Methyltransferases/genetics , Signal Transduction , Transcriptional Activation/drug effectsABSTRACT
Protein arginine methyltransferase CARM1 has been shown to methylate a large number of non-histone proteins, and play important roles in gene transcriptional activation, cell cycle progress, and tumorigenesis. However, the critical substrates through which CARM1 exerts its functions remain to be fully characterized. Here, we reported that CARM1 directly interacts with the GATAD2A/2B subunit in the nucleosome remodeling and deacetylase (NuRD) complex, expanding the activities of NuRD to include protein arginine methylation. CARM1 and NuRD bind and activate a large cohort of genes with implications in cell cycle control to facilitate the G1 to S phase transition. This gene activation process requires CARM1 to hypermethylate GATAD2A/2B at a cluster of arginines, which is critical for the recruitment of the NuRD complex. The clinical significance of this gene activation mechanism is underscored by the high expression of CARM1 and NuRD in breast cancers, and the fact that knockdown CARM1 and NuRD inhibits cancer cell growth in vitro and tumorigenesis in vivo. Targeting CARM1-mediated GATAD2A/2B methylation with CARM1 specific inhibitors potently inhibit breast cancer cell growth in vitro and tumorigenesis in vivo. These findings reveal a gene activation program that requires arginine methylation established by CARM1 on a key chromatin remodeler, and targeting such methylation might represent a promising therapeutic avenue in the clinic.
Subject(s)
Breast Neoplasms , Chromatin Assembly and Disassembly , Gene Expression Regulation, Neoplastic , Mi-2 Nucleosome Remodeling and Deacetylase Complex , Protein-Arginine N-Methyltransferases , Mi-2 Nucleosome Remodeling and Deacetylase Complex/metabolism , Mi-2 Nucleosome Remodeling and Deacetylase Complex/genetics , Protein-Arginine N-Methyltransferases/genetics , Protein-Arginine N-Methyltransferases/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Breast Neoplasms/metabolism , Humans , Female , Animals , Cell Line, Tumor , Cell Cycle/genetics , Mice , Methylation , Arginine/metabolism , Carcinogenesis/genetics , Transcriptional ActivationABSTRACT
Although brassinolide (BR) and jasmonic acid (JA) play essential roles in the regulation of cold stress responses, the molecular basis of their crosstalk remains elusive. Here, we show a key component of BR signaling in apple (Malus × domestica), BR INSENSITIVE1 (BRI1)-EMS-SUPPRESSOR1 (BES1)-INTERACTING MYC-LIKE PROTEIN1 (MdBIM1), increases cold tolerance by directly activating expression of C-REPEAT BINDING FACTOR1 (MdCBF1) and forming a complex with C-REPEAT BINDING FACTOR2 (MdCBF2) to enhance MdCBF2-activated transcription of cold-responsive genes. Two repressors of JA signaling, JAZMONATE ZIM-DOMAIN1 (MdJAZ1) and JAZMONATE ZIM-DOMAIN2 (MdJAZ2), interact with MdBIM1 to integrate BR and JA signaling under cold stress. MdJAZ1 and MdJAZ2 reduce MdBIM1-promoted cold stress tolerance by attenuating transcriptional activation of MdCBF1 expression by MdBIM1 and interfering with the formation of the MdBIM1-MdCBF2 complex. Furthermore, the E3 ubiquitin ligase ARABIDOPSIS TÓXICOS en LEVADURA73 (MdATL73) decreases MdBIM1-promoted cold tolerance by targeting MdBIM1 for ubiquitination and degradation. Our results not only reveal crosstalk between BR and JA signaling mediated by a JAZ-BIM1-CBF module but also provide insights into the posttranslational regulatory mechanism of BR signaling.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Malus , Brassinosteroids/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Malus/genetics , Malus/metabolism , Arabidopsis/metabolism , Gene Expression Regulation, PlantABSTRACT
Auxin/indole-3-acetic acid (AUX/IAA) and auxin response factor (ARF) proteins are important components of the auxin signalling pathway, but their ubiquitination modification and the mechanism of auxin-mediated anthocyanin biosynthesis remain elusive. Here, the ARF MdARF5-1 was identified as a negative regulator of anthocyanin biosynthesis in apple, and it integrates auxin and ethylene signals by inhibiting the expression of the ethylene response factor MdERF3. The auxin repressor MdIAA29 decreased the inhibitory effect of MdARF5-1 on anthocyanin biosynthesis by attenuating the transcriptional inhibition of MdERF3 by MdARF5-1. In addition, the E3 ubiquitin ligases MdSINA4 and MdSINA11 played negative and positive regulatory roles in anthocyanin biosynthesis by targeting MdIAA29 and MdARF5-1 for ubiquitination degradation, respectively. MdSINA4 destabilized MdSINA11 to regulate anthocyanin accumulation in response to auxin signalling. In sum, our data revealed the crosstalk between auxin and ethylene signals mediated by the IAA29-ARF5-1-ERF3 module and provide new insights into the ubiquitination modification of the auxin signalling pathway.
Subject(s)
Malus , Ubiquitin-Protein Ligases , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Malus/genetics , Malus/metabolism , Anthocyanins , Indoleacetic Acids/metabolism , Ethylenes , Gene Expression Regulation, Plant , Plant Proteins/genetics , Plant Proteins/metabolismABSTRACT
PHR1 (PHOSPHATE STARVATION RESPONSE1) plays key roles in the inorganic phosphate (Pi) starvation response and in Pi deficiency-induced anthocyanin biosynthesis in plants. However, the post-translational regulation of PHR1 is unclear, and the molecular basis of PHR1-mediated anthocyanin biosynthesis remains elusive. In this study, we determined that MdPHR1 was essential for Pi deficiency-induced anthocyanin accumulation in apple (Malus × domestica). MdPHR1 interacted with MdWRKY75, a positive regulator of anthocyanin biosynthesis, to enhance the MdWRKY75-activated transcription of MdMYB1, leading to anthocyanin accumulation. In addition, the E3 ubiquitin ligase SEVEN IN ABSENTIA1 (MdSINA1) negatively regulated MdPHR1-promoted anthocyanin biosynthesis via the ubiquitination-mediated degradation of MdPHR1. Moreover, the protein kinase apple BRASSINOSTEROID INSENSITIVE2 (MdBIN2) phosphorylated MdPHR1 and positively regulated MdPHR1-mediated anthocyanin accumulation by attenuating the MdSINA1-mediated ubiquitination degradation of MdPHR1. Taken together, these findings not only demonstrate the regulatory role of MdPHR1 in Pi starvation induced anthocyanin accumulation, but also provide an insight into the post-translational regulation of PHR1.
Subject(s)
Malus , Malus/genetics , Malus/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Anthocyanins/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Ubiquitination , Gene Expression Regulation, PlantABSTRACT
The imaging range of traditional plane wave imaging is usually limited by the directivity of the plane wave. In this paper, a multi spherical wave imaging method based on an ultrasonic array is proposed, which radiates both compression and shear waves in a solid medium to form the multi spherical wave. Firstly, excitation characteristics of the multi spherical wave are analyzed theoretically and the calculation method of echo delay of multi spherical wave imaging is derived. Multi spherical wave imaging is compared with conventional ultrasonic plane wave imaging by designing experiments. Compared with ultrasonic plane wave imaging, multi spherical wave imaging is not limited to the size of the transducer and can greatly improve the detection range. In addition, compared with the multi plane wave imaging method, the multi spherical wave imaging algorithm is relatively simple, fast, and has high application value.
Subject(s)
Data Compression , Ultrasonics , Algorithms , Phantoms, Imaging , UltrasonographyABSTRACT
The fate and exposure of chemicals in sewage treatment plants (STPs) are major considerations in risk assessment and environmental regulation. The biodegradability and removal of seven aromatic amines were systematically evaluated using a three-tiered integrated method: a standard ready biodegradability test, an aerobic sewage treatment simulation method, and model prediction. In tier 1, the seven aromatic amines were not readily biodegraded after 28 days. In adapted aerobic active sludge, 4-isopropyl aniline, 2,4-diaminotoluene, and 4-nitroaniline among them exhibited the degradation half-life time less than 20 h, the other four aromatic amines exhibited persistent with degradation half-life of > 60 h. In tier 2 of the aerobic sewage treatment simulation testing, 2,4-diaminotoluene, 4-nitroaniline, and 4-isopropylaniline demonstrated moderately to high overall removal. Hydraulic retention time (HRT) affects the removal with the optimum HRT was determined to be 12 h to 24. 2,6-Dimethyl aniline, 2-chloro-4-nitroaniline, 2,6-diethylaniline, and 3,4-dichloroaniline were not removed during the test, indicting these four aromatic amines will enter surface water and hence pose a potential risk to aquatic ecology. Considering the lack of an STP model in China for regulation purposes, in tier 3, we developed a Chinese STP (aerobic) (abbreviated as C-STP(O)) model that reflects a universal scenario for China to predict the fate. The predicted degradation, volatilization, and absorption showed a close relationship to the physicochemical properties of the chemicals, and had same tendency with tier 2 simulation test. The prediction showed that biodegradation rather than absorption or volatilization was the main removal process of aromatic amines in aerobic STP. With the combination of modified kinetics test with C-STP (O) model, the chemical fate can be more accurately predicted than using only the readily biodegradation result.
Subject(s)
Amines/analysis , Environmental Monitoring , Waste Disposal, Fluid , Water Pollutants, Chemical , Biodegradation, Environmental , China , SewageABSTRACT
BACKGROUND: Fall dormancy and freezing tolerance characterized as two important phenotypic traits, have great effects on productivity and persistence of alfalfa (Medicago sativa L.). Despite the fact that one of the most limiting traits for alfalfa freezing tolerance in winter is fall dormancy, the interplay between fall dormancy and cold acclimation processes of alfalfa remains largely unknown. We compared the plant regrowth, winter survival, raffinose and amino acids accumulation, and genome-wide differentially expressed genes of fall-dormant cultivar with non-dormant cultivar under cold acclimation. RESULTS: Averaged over both years, the non-dormant alfalfa exhibited largely rapid regrowth compared with fall dormant alfalfa after last cutting in autumn, but the winter survival rate of fall dormant alfalfa was about 34-fold higher than that of non-dormant alfalfa. The accumulation of raffinose and amino acids were significantly increased in fall dormant alfalfa, whereas were decreased in non-dormant alfalfa under cold acclimation. Expressions of candidate genes encoding raffinose biosynthesis genes were highly up-regulated in fall dormant alfalfa, but down-regulated in non-dormant alfalfa under cold acclimation. In fall dormant alfalfa, there was a significantly down-regulated expression of candidate genes encoding the glutamine synthase, which is indirectly involved in the proline metabolism. A total of eight significantly differentially expressed transcription factors (TFs) related to CBF and ABRE-BFs were identified. The most up-regulated TFs in fall dormant alfalfa cultivar were ABF4 and DREB1C. CONCLUSIONS: Fall dormant alfalfa drastically increased raffinose and amino acids accumulation under cold acclimation. Raffinose-associated and amino acid-associated genes involved in metabolic pathways were more highly expressed in fall dormant alfalfa than non-dormant alfalfa under cold acclimation. This global survey of transcriptome profiles provides new insights into the interplay between fall dormancy and cold acclimation in alfalfa.
Subject(s)
Gene Expression Regulation, Plant/physiology , Medicago sativa/physiology , Plant Dormancy/genetics , Plant Proteins/genetics , Transcriptome/physiology , Gene Expression Profiling , Longevity , Medicago sativa/genetics , SeasonsABSTRACT
A triple reflection grazing incidence x-ray telescope is proposed and evaluated. This form of an optical system can detect x-ray energy that is close to the optical axis, which solves the problems encountered by traditional Wolter-type systems. In this paper, we also propose a new design method to ensure that the entire telescope structure is compact and integrated. Finally, a proof-of-concept design with an acceptable image quality is proposed.
ABSTRACT
We propose a new panossramic optical system that provides an additional field of view (FOV) channel without expanding the physical size of a conventional panoramic annular lens (PAL). The two channels are contained within one PAL, their optical paths do not interfere with each other, and the two images are realized on a single image plane. A prototype panoramic lens was developed that provides a 360° × (38-80°) front FOV channel and a 360° × (102-140°) back FOV channel.
ABSTRACT
OBJECTIVES: To apply chromosomal microarray analysis (CMA) in the diagnosis of karyotyping with uncertain genomic rearrangement. METHODS: We retrospectively reviewed 48 samples (34 samples of amniotic fluid, 14 samples of peripheral blood) of karyotype analyses with uncertain genomic rearrangement in patients admitted to our department from September 2014 to April 2016. The CMA results were compared with those of karyotyping. RESULTS: The 48 samples consisted of 13 samples with marker chromosomes, 19 samples with derivative chromosomes, and 16 samples with balanced translocation. Sixteen cases (33.33%) were detected with abnormalities by CMA. In the 32 samples with marker chromosomes or derivative chromosomes, 16 cases were detected with deletions or duplications (>5 Mb) by CMA, including 1 case 21-trisomy, 2 cases XYY syndrome and 3 cases microdeletion/ microduplication syndromes (22q11 duplication syndrome, Wolf-Hirschhorn syndrome and 15q26 overgrowth syndrome). In the 16 balanced translocation cases, all revealed negative results in CMA. CONCLUSIONS: CMA can confirm the karyotyping with uncertain genomic rearrangement and clarify its clinical significance.
Subject(s)
Chromosome Disorders/diagnosis , Gene Rearrangement , Karyotyping , Microarray Analysis , Prenatal Diagnosis , Female , Genome, Human , Humans , Pregnancy , Retrospective StudiesABSTRACT
BACKGROUND: Low vitamin D status has been associated with increased risk of cardiovascular disease. Atrial fibrillation (AF) is the most common cardiac arrhythmia. We evaluated the association between low vitamin D and AF. METHODS: We analyzed data from 162 Chinese patients with nonvalvular persistent AF and no other cardiovascular disease whose serum 25-hydroxyvitamin D [25(OH)D] levels were measured in our hospital (AF group). Healthy subjects without AF who underwent health screening at our hospital served as controls (non-AF group, n = 160). 25(OH)D was measured by chemiluminescence assay. RESULTS: The serum 25(OH)D level was significantly lower in the AF group than in the non-AF group (18.5 ± 10.3 vs 21.4 ± 10.7 ng/mL, P < 0.05). The high-sensitivity C-reactive protein (hsCRP) level was significantly higher in the AF group than in the non-AF group (0.35 ± 0.19 vs 0.2 ± 0.17 mg/dL, P < 0.01). The average left atrial diameter was significantly larger in the AF group than in the non-AF group (P < 0.01). The serum 25(OH)D level showed a negative correlation with left atrial diameter, hsCRP level, and pulmonary artery systolic pressure. Logistic regression analysis identified that 25(OH)D was related to AF. Patients whose vitamin D levels were in the lowest 25(OH)D category (<20 ng/mL) were more often in the AF group, with their incidence about twofold higher than those in the highest 25(OH)D category (>30 ng/mL). CONCLUSIONS: Low vitamin D levels are associated with AF. It may be involved in its development.
Subject(s)
Atrial Fibrillation/blood , Vitamin D/analogs & derivatives , Aged , Atrial Fibrillation/physiopathology , Blood Pressure/physiology , C-Reactive Protein , China , Female , Heart Atria/diagnostic imaging , Heart Atria/physiopathology , Humans , Luminescent Measurements/methods , Male , Middle Aged , Risk Factors , Ultrasonography , Vitamin D/bloodABSTRACT
AIMS: Amino acids (AAs) are known to play important roles in various physiological functions. However, their effect on sweet taste perception remains largely unknown. MAIN METHODS: We used Drosophila to evaluate the effect of each AA on sucrose taste perception. Individual AA was supplemented into diets and male flies were fed on these diets for 6 days. The proboscis extension response (PER) assay was applied to assess the sucrose taste sensitivity of treated flies. We further utilized the RNA-seq and germ-free (GF) flies to reveal the underlying mechanisms of sucrose taste sensitization induced by glutamine (Gln). KEY FINDINGS: We found that supplementation of Gln into diets significantly enhances sucrose taste sensitivity. This sucrose taste sensitization is dependent on gut microbiota and requires a specific gut bacterium Acetobacter tropicalis (A. tropicalis). We further found that CNMamide (CNMa) in the gut and CNMa receptor (CNMaR) in dopaminergic neurons are required for increased sucrose taste sensitivity by Gln diet. Finally, we demonstrated that a gut microbiota-gut-brain axis is required for Gln-induced sucrose taste sensitization. SIGNIFICANCE: These findings can advance understanding of the complex interplay between host physiology, dietary factors, and gut microbiota.
Subject(s)
Drosophila , Taste Perception , Animals , Male , Drosophila/physiology , Taste Perception/physiology , Taste/physiology , Glutamine , Sucrose , Brain-Gut Axis , Drosophila melanogasterABSTRACT
Right heart thrombus (RHT) is a rare but life-threatening condition in acute pulmonary embolism (APE) without clear management guidelines. This study aimed to address the clinical characteristics and outcomes of RHT-APE in Chinese patients. In this study, 17 RHT-APE and 329 non-RHT-APE patients, who were diagnosed between September 2015 and August 2019, were retrospectively recruited with the median follow-up was 360 days. The overall prevalence of RHT was 4.91% in APE. Its prevalence increased along the increase of APE risk stratifications. Comparisons showed that with higher proportion of male gender and younger age, RHT-APE patients also had worse hemodynamic instability and heart function, and higher risk stratification levels than non-RHT-APE patients. After adjusting by age and gender, multivariate logistic regression analysis found high/intermediate-high risk stratification, decreased right ventricular (RV) motion, NT-proBNP >600 pg/mL, and RV dysfunction were risk factors for RHT. Kaplan-Meier analysis showed non-RHT had better prognosis than RHT patients (30-day survival: log-rank: p < 0.001; 90-day survival: log-rank: p = 0.002). The multivariate logistic regression analysis showed RHT was an independent risk factor for 30-day mortality in APE. The subgroup analysis showed RHT would result in worse outcomes in patients who already had higher APE early mortality risk. RHT would increase the risk of 30- and 90-day mortality in APE. More attention should be paid to young male APE patients with decreased RV motion, NT-proBNP >600 pg/mL, RV dysfunction, or high level of risk stratification, to exclude the coexistence of RHT.
ABSTRACT
Anti-obesity medications act by suppressing energy intake (EI), promoting energy expenditure (EE), or both. Metformin (Met) and mirabegron (Mir) cause weight loss by targeting EI and EE, respectively. However, anti-obesity effects during concurrent use of both have yet to be explored. In this study, we investigated the anti-obesity effects, metabolic benefits, and underlying mechanisms of Met/Mir combination therapy in two clinically relevant contexts: the prevention model and the treatment model. In the prevention model, Met/Mir caused further 12% and 14% reductions in body weight (BW) gain induced by a high-fat diet compared to Met or Mir alone, respectively. In the treatment model, Met/Mir additively promoted 17% BW loss in diet-induced obese mice, which was 13% and 6% greater than Met and Mir alone, respectively. Additionally, Met/Mir improved glucose tolerance and insulin sensitivity. These benefits of Met/Mir were associated with increased EE, activated brown adipose tissue thermogenesis, and white adipose tissue browning. Significantly, Met/Mir did not cause cardiovascular dysfunction in either model. Together, the combination of Met and Mir could be a promising approach for the prevention and treatment of obesity by targeting both EI and EE simultaneously.
ABSTRACT
Dietary protein (P) and carbohydrate (C) have a major impact on the sweet taste sensation. However, it remains unclear whether the balance of P and C influences the sweet taste sensitivity. Here, we use the nutritional geometry framework (NGF) to address the interaction of protein and carbohydrates on sweet taste using Drosophila as a model. Our results reveal that high-protein, low-carbohydrate (HPLC) diets sensitize to sweet taste and low-protein, high-carbohydrate (LPHC) diets desensitize sweet taste in both male and female flies. We further investigate the underlying mechanisms of the effects of two diets on sweet taste using RNA sequencing. When compared to the LPHC diet, the mRNA expression of genes involved in the metabolism of glycine, serine, and threonine is significantly upregulated in the HPLC diet group, suggesting these amino acids may mediate sweet taste perception. We further find that sweet sensitization occurs in flies fed with the LPHC diet supplemented with serine and threonine. Our study demonstrates that sucrose taste sensitivity is affected by the balance of dietary protein and carbohydrates possibly through changes in serine and threonine.
Subject(s)
Taste Perception , Taste , Animals , Male , Female , Taste Perception/genetics , Sucrose/pharmacology , Drosophila/genetics , Carbohydrates/pharmacology , Dietary Proteins/pharmacology , Serine/pharmacology , Threonine/pharmacologyABSTRACT
OBJECTIVE: To establish in vitro culture procedure for human amniotic fluid-derived CD117 positive stem cells, and to identify the characteristics of CD117 positive stem cells. METHODS: 86 amniotic fluid samples (10 mL of each) were obtained by second-trimester amniocentesis. Isolation of amniotic fluid-derived stem cells expressing CD117 antigen was performed via magnetic cell sorting using the CD117 MicroBead Kit. The karyotype of CD117 positive stem cells was analysed through repeated freezing. Adipogenic differentiation of these CD117 positive stem cells was displayed by Oil Red O staining. Osteogeneic differentiation of these CD117 positive stem cells was confirmed by Alizarin Red staining. RESULTS: The CD117 positive stem cells were successfully isolated and cultured from 61 samples, with all showing normal karyotype. Product analysis of specific staining confirmed that under specific culture mediums, these cells could be successfully induced to differentiate into adipocytes and osteocytes. CONCLUSION: Based on this study, we estimate that isolating CD117 positive stem cells from second-trimester amniotic fluid obtained by amniocentesis has a success rate of 70.93%. These cells maintain morphological and genetic stability in vitro. Human amniotic fluid-derived CD117 positive stem cells have the ability to differentiate in vitro into adipocytes and osteocytes under specific culture mediums and may be applied in cell transplantation and regenerative medicine.
Subject(s)
Amniotic Fluid/cytology , Cell Culture Techniques/methods , Cell Differentiation/physiology , Stem Cells/cytology , Adipocytes/cytology , Adolescent , Adult , Cell Separation , Cells, Cultured , Female , Humans , Osteoblasts/cytology , Pregnancy , Pregnancy Trimester, Second , Proto-Oncogene Proteins c-kit/metabolism , Young AdultABSTRACT
Multiphase reactive transport in porous media is an important component of many natural and engineering processes. In the present study, boundary schemes for the continuum species transport-lattice Boltzmann (CST-LB) mass transport model and the multicomponent pseudopotential model are proposed to simulate heterogeneous chemical reactions in a multiphase system. For the CST-LB model, a lattice-interface-tracking scheme for the heterogeneous chemical reaction boundary is provided. Meanwhile, a local-average virtual density boundary scheme for the multicomponent pseudopotential model is formulated based on the work of Li et al. [Li, Yu, and Luo, Phys. Rev. E 100, 053313 (2019)10.1103/PhysRevE.100.053313]. With these boundary treatments, a numerical implementation is put forward that couples the multiphase fluid flow, interfacial species transport, heterogeneous chemical reactions, and porous matrix structural evolution. A series of comparison benchmark cases are investigated to evaluate the numerical performance for different pseudopotential wetting boundary treatments, and an application case of multiphase dissolution in porous media is conducted to validate the present models' ability to solve complex problems. By applying the present LB models with reasonable boundary treatments, multiphase reactive transport in various natural or engineering scenarios can be simulated accurately.
ABSTRACT
Many studies show that genetics play a major contribution to the onset of obesity. Human genome-wide association studies (GWASs) have identified hundreds of genes that are associated with obesity. However, the majority of them have not been functionally validated. SEC16B has been identified in multiple obesity GWASs but its physiological role in energy homeostasis remains unknown. Here, we use Drosophila to determine the physiological functions of dSec16 in energy metabolism. Our results showed that global RNAi of dSec16 increased food intake and triglyceride (TAG) levels. Furthermore, this TAG increase was observed in flies with a specific RNAi of dSec16 in insulin-like peptide producing cells (IPCs) with an alteration of endocrine peptides. Together, our study demonstrates that dSec16 acting in IPCs controls energy balance and advances the molecular understanding of obesity.
ABSTRACT
In the present study, a numerical model based on the lattice Boltzmann method (LBM) is proposed to simulate multiphase mass transfer, referred to as the CST-LB model. This model introduced continuum species transfer (CST) formulation by an additional collision term to model the mass transfer across the multiphase interface. The boundary condition treatment of this model is also discussed. In order to verify the applicability, the CST-LB model is combined with the pseudopotential multiphase model to simulate a series of benchmark cases, including concentration jump near the interface, gas dissolution in a closed system, species transport during drainage in a capillary tube, and multiphase species transport in the porous media. This CST-LB model can also be coupled with other multiphase LBMs since the model depends on the phase fraction field, which is not explicitly limited to specified multiphase models.