From inflammation to depression: key biomarkers for IBD-related major depressive disorder.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic, inflammatory, and autoimmune disorder, and its incidence of comorbid with major depressive disorder (MDD) is significantly higher than the general population. However, many patients lack proper recognition and necessary psychological health treatments. We aimed to identify potential biomarkers and mechanisms involved in the development of IBD comorbid with MDD (IBD-MDD). METHODS: We utilized IBD and MDD-related datasets from the GEO database for differential gene expression analysis, protein-protein interaction (PPI) and pathway enrichment analysis, random forest algorithm, LASSO regression analysis, and construction of a disease prediction model. We assessed the accuracy of the model using ROC curve, explored potential mechanisms through immune infiltration analysis, and validated candidate biomarkers using peripheral blood samples from patients in our center's cohort. RESULTS: We identified 484 IBD-related secreted proteins and 142 key module genes associated with MDD. PPI analysis revealed two crucial modules primarily involved in inflammation and immune regulation. We identified four diagnostic genes (HGF, SPARC, ADAM12, and MMP8) from the 21 shared genes between IBD-related secreted proteins and MDD key module genes, constructed a nomogram model and confirmed its accuracy using ROC curve from an external independent dataset. Immune infiltration analysis revealed significant associations between the four diagnostic genes, and cellular immune dysregulation in MDD. Finally, we validated the expression patterns of the four diagnostic genes in our cohort. CONCLUSIONS: Our study discovered four candidate biomarkers for IBD-MDD, providing new insights for the diagnosis and therapeutic intervention of serum-based IBD comorbid with MDD.

First-principles study of valley splitting of transition-metal dichalcogenides in MX2/CrI3 (M = W, Mo; X = S, Se, Te) van der Waals heterostructures.

The rapid development of valleytronics makes the application of two-dimensional (2D) transition-metal dichalcogenides (TMDs) in valley electronics important. As a new degree of freedom, valley splitting of TMDs has been achieved and tuned by many methods. Among them, using the magnetic proximity effect (MPE) generated from the interface of 2D van der Waals (vdW) heterostructures stacked with TMDs and one magnetic substrate, valley splitting can be achieved through band edge lifting at the adjacent K/K' valley. However, the comprehensive mechanism and strategy of valley splitting in 2D TMD heterostructures need to be explored ulteriorly. Here, we systematically investigated valley splitting of MX2 in MX2/CrI3 (M = W, Mo; X = S, Se, Te) vdW heterostructures using first-principles approaches. We demonstrated that twisting is an effective method to enhance valley splitting in MX2/CrI3 vdW heterostructures. Furthermore, we also showed a ∼10 times enhancement in valley splitting by changing the stacking patterns between WTe2 and CrI3 layers. We attribute this to the interlayer magnetic and electronic coupling between the two layers of the vdW heterostructure. The present results provide a theoretical basis and effective methods for tuning valley splitting 2D TMD heterostructures.

Metabolomic analysis in Amycolatopsis keratiniphila disrupted the competing ECO0501 pathway for enhancing the accumulation of vancomycin.

Vancomycin is a clinically important glycopeptide antibiotic against Gram-positive pathogenic bacteria, especially methicillin-resistant Staphylococcus aureus. In the mutant strain of Amycolatopsis keratiniphila HCCB10007 Δeco-cds4-27, the production of ECO-0501 was disrupted, but enhanced vancomycin yield by 55% was observed compared with the original strain of A. keratiniphila HCCB10007. To gain insights into the mechanism of the enhanced production of vancomycin in the mutant strain, comparative metabolomics analyses were performed between the mutant strain and the original strain, A. keratiniphila HCCB10007 via GC-TOF-MS and UPLC-HRMS. The results of PCA and OPLS-DA revealed a significant distinction of the intracellular metabolites between the two strains during the fermentation process. 64 intracellular metabolites, which involved in amino acids, fatty acids and central carbon metabolism, were identified as differential metabolites. The high-yield mutant strain maintained high levels of glucose-1-phosphate and glucose-6-phosphate and they declined with the increases of vancomycin production. Particularly, a strong association of fatty acids accumulation as well as 3,5-dihydroxyphenylacetic acid and non-proteinogenic amino acid 3,5-dihydroxyphenylglycine (Dpg) with enhancement of vancomycin production was observed in the high-yield mutant strain, indicating that the consumption of fatty acid pools might be beneficial for giving rise to 3,5-dihydroxyphenylacetic acid and Dpg which further lead to improve vancomycin production. In addition, the lower levels of glyoxylic acid and lactic acid and the higher levels of sulfur amino acids might be beneficial for improving vancomycin production. These findings proposed more advanced elucidation of metabolomic characteristics in the high-yield strain for vancomycin production and could provide potential strategies to enhance the vancomycin production.

Rhodamine-based fluorescent sensors for the rapid and selective off-on detection of salicylic acid and their use in plant cell imaging.

Salicylic acid (SA) is a key hormone that regulates plant growth and immunity, and understanding the physiologic processes induced by SA enables the development of highly pathogen-resistant crops. Here, we report the synthesis of three new SA-sensors (R1-R3) from hydroxyphenol derivatives of a rhodamine-acylhydrazone scaffold and their characterization by NMR and HRMS. Spectroscopic analyses revealed that structural variations in R1-R3 resulted in sensors with different sensitivities for SA. Sensor R2 (with the 3-hydroxyphenyl modification) outperformed R1 (2-hydroxyphenyl) and R3 (4-hydroxyphenyl). The SA-detection limit of R2 is 0.9 µM with an ultra-fast response time (<60 s). In addition, their plant imaging indicated that designed sensor R2 is useful for the further study of SA biology and the discovery and development of new inducers of plant immunity.

Interfacial effects on lithium-ion diffusion in two-dimensional lateral black phosphorus-graphene heterostructures.

Lateral heterostructures constructed from different two-dimensional (2D) materials can be potentially used in lithium-ion batteries (LIBs). The interface between two different components strongly affects LIB charge and discharge processes. Herein, the atomic structures, electronic properties, and Li-ion diffusion characteristics of lateral black phosphorus-graphene (BP-G) heterostructures are studied via first-principles calculations. The obtained results reveal that BP-G heterostructures with either zigzag (ZZ) or misoriented interfaces constructed according to Clar's rule possess a small number of interfacial states and are electronically stable. Furthermore, compared with the perfect ZZ interface of BP-G, Clar's interfaces provide a larger number of diffusion paths with much lower energy barriers. The findings of this study suggest that lateral BP-G heterostructures can provide insights for rapid charge and discharge processes in LIBs.

Electronic and magnetic properties of charged point defects in monolayer CrI3.

The two-dimensional magnetic material CrI3 has gained considerable attention owing to its promising applications in photoelectric and spin-related devices. Recently, various structural defects in CrI3 have been identified; however, the charge states of these defects have been mainly ignored. Here, we report on an investigation of the charged defects in monolayer CrI3, focused on the electronic and magnetic properties of the five most stable point defects using first-principles calculations. For positively charged I vacancies and negatively charged Cr vacancies, a blue- and red-shift of defect states near the Fermi level can be observed because of the atom relaxation. Our results also indicate that, among the five defects, the Cr interstitial defect has the smallest ionization energy of 0.34 eV, which makes its ionization easiest. Furthermore, a 0.2 µB enhancement of the magnetic moment on the nearest Cr atom can be found for the I vacancy and Cr interstitial defect. The investigation contributes to the atomic-scale comparison and understanding of the charged defects of monolayer CrI3.

Investigation of the optical properties of a deep-ultraviolet LED with an Al nanograting structure.

The optical properties of deep-ultraviolet (DUV) light-emitting diode (LED) with Al nanograting structure are investigated by three-dimensional (3D) finite-difference time-domain (FDTD) simulation. The peak intensity of TE and TM polarization radiation recombination rate of the grating structure is increased by 33.3% and 22.0% as compared to the control structure with Al plane. The light extraction efficiency (LEE) of the emitted light whose propagation direction is in the plane perpendicular to the Al-grating ridge is much higher than that in the plane parallel to the Al-grating ridge due to the scattering of the grating. Without considering the lateral surface extraction and packaging, the total LEE of the grating structure can be improved by 41.4% as compared to the control structure. The peak intensity of the output spectrum of the DUV LED with the grating structure can be increased by 70.3%.

Association of sleep duration with sarcopenic obesity in multi-ethnic older adults: findings from the WCHAT Study.

OBJECTIVE: Sarcopenic obesity is a prevalent geriatric syndrome, characterized by concurrence of sarcopenia and obesity. Sleep duration is linked to both obesity and sarcopenia. However, little was known regarding the association of sleep duration with sarcopenic obesity. In this study, we aimed to examine the association of sleep duration with sarcopenic obesity in multi-ethnic community-dwelling older adults. METHODS: Sarcopenia was defined according to the criteria established by Asian Working Group for Sarcopenia (AWGS) 2019. Obesity was defined as body fat percentage above the 60th percentile specified by sex. Sarcopenic obesity was defined as concurrence of obesity and sarcopenia. Sleep duration was collected by a self-reported questionnaire and was further divided into 5 groups: "<6 h", "6-7 h", "7-8 h", "8-9 h" (reference group) and "≥9 h" (long sleep). Logistic regressions were adopted to examine the association. RESULTS: 2256 multi-ethnic adults aged 60 and over from the West China Health and Aging Trend (WCHAT) study were involved for present study. Overall, 6.25% of the participants were classified as sarcopenic obesity. In the fully adjusted model, long sleep duration (≥ 9 h) was significantly associated with sarcopenic obesity compared with reference group (OR = 1.81, 95%CI = 1.10-2.98, P = 0.019). However, in subgroup analysis, this association can only be observed in male (OR 1.98, 95% CI = 1.02-3.87, P = 0.043) not in female (OR = 1.83, 95%CI = 0.85-3.94, P = 0.118). Regarding ethnic difference, Han older adults with long sleep duration (≥ 9 h) presented increased risk of sarcopenic obesity while ethnic minorities did not. CONCLUSION: This study disclosed that long sleep duration significantly increased the risk of sarcopenic obesity among older adults. And our findings highlight the critical role of assessing sleep duration to identify individuals at risk of sarcopenic obesity.

Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy: The Utility of Myocardial Strain Based on Cardiac MR Tissue Tracking.

BACKGROUND: Myocardial strain for assessment of hypertrophic cardiomyopathy (HCM) is of importance and may play a role in identifying obstruction in HCM patients. PURPOSE: To evaluate the utility of myocardial strain for detecting left ventricular (LV) outflow tract (LVOT) obstruction in HCM patients based on magnetic resonance tissue tracking. STUDY TYPE: Retrospective. POPULATION: In all, 44 adult HCM patients with LVOT obstruction and 108 adult HCM patients without LVOT obstruction. FIELD STRENGTH/SEQUENCE: 1.5 T; Steady-state free-precession cine sequence; phase-sensitive inversion-prepared segmented gradient echo sequence for late gadolinium enhancement (LGE) imaging. ASSESSMENT: Strain parameters including the local and global levels of LV myocardium and the subtraction (Sub) of myocardial strain variables between interventricular septal segments (IVSS) and noninterventricular septal segments (NIVSS) were measured for differentiating HCM with obstruction from nonobstruction. Average and maximum LV wall thickness (Average and Maximum LVWT) were also analyzed. STATISTICAL TESTS: Univariate and multivariate logistic regression analysis, area under the receiver operating characteristic (ROC) curve (AUC), intraclass correlation coefficient. RESULTS: In multivariate analysis, Average LVWT, Maximum LVWT, and the subtraction of radial peak strain (Sub Radial PS) between NIVSS and IVSS were independently associated with LVOT obstruction. The AUCs were 0.731, 0.840, and 0.890 for Average LVWT, Maximum LVWT, and Sub Radial PS, respectively. Sub Radial PS (cutoff value: 8.1%) demonstrated the highest sensitivity of 75.0% and a high specificity of 87.9% for identifying LVOT; Maximum LVWT (cutoff value: 22.9 mm) showed good sensitivity (72.7%) and specificity (83.3%). Combining Maximum LVWT >22.9 mm and Sub Radial PS > 8.1% achieved a better diagnostic performance (specificity 95.4%, sensitivity 70.5%). DATA CONCLUSION: Combining Maximum LVWT >22.9 mm and Sub Radial PS >8.1% holds promise for objectively evaluating LVOT obstruction in HCM patients with very high specificity and acceptable sensitivity. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Switchable electronic and enhanced magnetic properties of CrI3 edges.

Owing to its novel electronic and magnetic properties, two-dimensional CrI3 has great potential in the application of spintronic devices. However, as an inevitable line defect, the properties of the edges of CrI3 remain elusive. Here, via first-principles calculations with spin-orbit coupling, we investigated the thermodynamic stabilities, electronic and magnetic properties of thirteen CrI3 edges with different structures. We showed that zigzag edges are more stable than armchair edges, and a CrI3 nanoribbon can be either metallic or insulating depending on its chemical growth conditions. The edge stability and associated electronic properties can be understood in terms of the octahedron ligand field and electron counting model. In most cases, both the magnetic moment and Curie temperature can be enhanced by edges, which are in startle contrast to the surfaces of three-dimensional ferromagnetic materials, where a magnetic dead layer is often observed.

The Framingham risk score is associated with incident frailty, or is it?

BACKGROUNDS: Cardiovascular disease (CVD) risk factors are individually associated with frailty. This study examined whether Framingham CVD risk score (FRS) as an aggregate measure of CVD risk is associated with incident frailty among Chinese older adults. METHODS: This study used data from the China Health and Retirement Longitudinal Study. A sample of 3,618 participants aged 60 to 95 years and without CVD at baseline were followed for four years. FRS was calculated at baseline. Frailty status was defined as not-frail (0-2 criteria) or frail (3-5 criteria) based on the physical frailty phenotype consisting of five binary criteria (weakness, slowness, exhaustion, low activity level, and weight loss). After excluding subjects who were frail (n = 248) at baseline, discrete-time Cox regression was used to evaluate the relationship between FRS and incident frailty. RESULTS: During a median follow-up of 4.0 years, 323 (8 %) participants developed CVD and 318 (11 %) subjects had frailty onset. Higher FRS was associated with greater risk of incident frailty (HR: 1.03, 95 % CI: 1.00 to 1.06) after adjusting for education, marital status, obesity, comorbidity burden, and cognitive function. This association however was no longer significant (HR: 1.00, 95 % CI: 0.97 to 1.03) after additionally adjusting for age. These findings remained essentially unchanged after excluding subjects with depression (n = 590) at baseline or incident CVD (n = 323) during the 4-year follow-up. CONCLUSIONS: The FRS was not independently associated with incident frailty after adjusting for chronological age. More research is needed to assess the clinical utility of the FRS in predicting adverse health outcomes other than CVD in older adults.

CRISPR/Cas9-deaminase enables robust base editing in Rhodobacter sphaeroides 2.4.1.

BACKGROUND: CRISPR/Cas9 systems have been repurposed as canonical genome editing tools in a variety of species, but no application for the model strain Rhodobacter sphaeroides 2.4.1 was unveiled. RESULTS: Here we showed two kinds of programmable base editing systems, cytosine base editors (CBEs) and adenine base editors (ABEs), generated by fusing endonuclease Cas9 variant to cytosine deaminase PmCDA1 or heterodimer adenine deaminase TadA-TadA*, respectively. Using CBEs, we were able to obtain C-to-T mutation of single and double targets following the first induction step, with the efficiency of up to 97% and 43%; while the second induction step was needed in the case of triple target, with the screening rate of 47%. Using ABEs, we were only able to gain A-to-G mutation of single target after the second induction step, with the screening rate of 30%. Additionally, we performed a knockout analysis to identify the genes responsible for coenzyme Q10 biosynthesis and found that ubiF, ubiA, ubiG, and ubiX to be the most crucial ones. CONCLUSIONS: Together, CBEs and ABEs serve as alternative methods for genetic manipulation in Rhodobacter sphaeroides and will shed light on the fundamental research of other bacteria that are hard to be directly edited by Cas9-sgRNA.

The Non-Concentration-Quenching Phosphor Ca3Eu2B4O12 for WLED Application.

Commercial white LED devices usually suffer from a high color temperature and poor color rendering. Developing a new, efficient, and stable red phosphor is the key to solving this problem. In this work, a series of pure Ca3Y2-xB4O12:xEu3+ (0 < x ≤ 2) samples, including the new and fully transitional borate phosphor Ca3Eu2B4O12 (CEBO), have been successfully prepared by solid-state reaction synthesis. CEBO is isostructural with Ca3Y2B4O12 (CYBO), belonging to the orthorhombic system with space group Pnma (No. 62). Under optimal 393 nm excitation, this borate exhibits a strong red emission, peaking at 615 nm, with high color purity. Interestingly, the luminescence of CEBO is relatively higher than that of CYBO:Eu3+ phosphors. The quantum yield of this non-concentration-quenching phosphor reaches 95.6%. Furthermore, a warm pc-WLED device has been fabricated by mixing as-prepared CEBO powders and commercial BaMgAl10O17:Eu2+ and (Sr, Ba)2SiO4:Eu2+ phosphors, which exhibits a high color rendering index (Ra = 83.7) along with a color temperature of around 3883 K. The present work indicates that this new borate, with outstanding quantum efficiency and favorable thermal stability, can be used as a red phosphor for application in WLEDs.

Three-Dimensional Free-Breathing Whole-Heart Coronary Magnetic Resonance Angiography at 1.5 T: Gadobutrol-Enhanced Gradient-Echo Acquisition Sequence Versus Non-Contrast-Enhanced Steady-State Free Precession Sequence.

OBJECTIVES: The objective of this study was to compare gadobutrol-enhanced gradient-echo sequence (GRE) acquisition with T2-prepared non-contrast-enhanced steady-state free precession (SSFP) in coronary magnetic resonance angiography at 1.5 T. METHODS: Twenty-one subjects successfully completed GRE and SSFP acquisition. Signal-to-noise ratio (SNR), contrast-to-noise ratio, image quality, sharpness, visibility, length, and lumen diameter of vessels were analyzed by 2 experienced radiologists. RESULTS: The SNR at whole left circumflex artery, left main artery, and proximal left descending artery (LAD) was significantly higher in SSFP acquisition (P < 0.05). The SNR of distal LAD was slightly higher in GRE acquisition (P < 0.05). The contrast-to-noise ratio at distal LAD, proximal and distal RCA were significantly higher with GRE acquisition (P < 0.05). CONCLUSIONS: Double-dose gadobutrol-enhanced GRE and unenhanced SSFP coronary magnetic resonance angiography at 1.5 T have their own characteristics, and the combined use of the 2 methods may be taken into consideration.

[Comparison of the Biological Functions between Human Bone Marrow Derived CD106 +Mesenchymal Stem Cells and CD106 - Subgroup].

Objective To analyze the differences in biological functions between bone marrow(BM)-derived CD106 +mesenchymal stem cells(MSCs)and the CD106 - subgroup. Methods The MSCs from normal BM were isolated and expanded.The subgroups of CD106 + and CD106 -MSCs were sorted.The cell proliferation and adhesion functions,chemotactic activities,adipogenic and osteogenic potentials,senescence,and senescence protein 21(p21)were detected.The capacity of translocation into nucleus of nuclear factor-kappa B(NF-κB)when stimulated by tumor necrosis factor(TNF-α)was measured. Results The proliferative ability was higher in CD106 +MSCs than that in CD106 -MSCs.In 48 hours,the value of optical density(OD)was significantly higher in CD106 +MSCs than that in CD106 - subgroup(1.004±0.028 vs. 0.659±0.023,t=3.946,P=0.0225).In 72 hours,this phenomenon was even more pronounced(2.574±0.089 vs. 1.590±0.074,t=11.240,P=0.0000).The adhesive capacity of CD106 +MSCs was significantly stronger than that of CD106 - subgroup(0.648±0.018 vs. 0.418±0.023,t=7.869,P=0.0002).Besides,the metastasis ability of CD106 +MSCs were significantly stronger than that of CD106 - subgroup(114.500±4.481 vs.71.000±4.435,t=6.900,P=0.0005).The CD106 +MSCs had signifcnatly lower proportions of senescent cells.The expression of aging protein p21 in CD106 +MSCs was significantly lower than that in CD106 -MSCs [(17.560±1.421)% vs.(45.800±2.569)%,t=9.618,P=0.0000].Furthermore,there were no visible pigmenting cells after ß-galactosidase staining in CD106 +MSCs subgroup.However,in CD106 -MSCs,some colored green cells were detected.The rate of NF-κB translocation into nucleus after stimulated by TNF-α was significantly higher in CD106 +MSCs than CD106 - MSCs [(37.780±3.268)% vs.(7.30±1.25)%,t=8.713,P=0.0001]. Conclusion Bone marrow-derived CD106 +MSCs possess more powerful biological functions than CD106 -MSCs.

Assay of Single-Cell Apoptosis by Ensemble and Single-Molecule Fluorescence Methods: Annexin-V/Polyethylene Glycol-Functionalized Quantum Dots as Probes.

Apoptosis plays a critical role in many biological processes and the etiology of various diseases of the immune system. The study of apoptosis would allow both improving the diagnosis of certain diseases and serving as a target of drug screening. In this paper, we developed a sensitive assay of single-cell apoptosis using semiconductor quantum dots (QDs) as fluorescent-labeling probes. The principle of this assay is based on the detection of phosphatidylserine (PS) exposed on the plasma membrane during the drug-induced apoptosis. The QD-labeled annexin V (AV) was prepared to specifically target PS on the membrane of apoptotic cells, and PS was detected by fluorescent imaging, flow cytometer, and single-molecule fluorescence correlation spectroscopy (FCS). We developed the procedures for conjugation of QDs to AV and for purification of their conjugates by gel chromatography. The obtained conjugates were characterized by FCS, capillary electrophoresis, and zeta potential analyzer. We studied the nonspecific adsorption of cells to different surface-modified QDs and found that the nonspecific adsorption effects were significantly reduced by modification of QDs with polyethylene glycol in the detection of apoptosis. In this assay, the results obtained by flow cytometry were consistent with the commercial test kit. Furthermore, a home-built single-molecule FCS system was developed for in situ study the drug-induced apoptosis. We observed the significant change in the diffusion coefficients of QDs on cells during the progress of cell apoptosis. Compared with conventional methods, the fluorescent methods represented here possess high sensitivity because of the use of high photo stability and brightness QDs as labeling probes and provide the temp-spatial information on a single apoptotic cell.

Extract of Paecilomyces hepiali mycelia induces lipolysis through PKA-mediated phosphorylation of hormone-sensitive lipase and ERK-mediated downregulation of perilipin in 3T3-L1 adipocytes.

BACKGROUND: Cordyceps sinensis has been used for centuries in China as one of the most valued herbal medicine and tonic food. Paecilomyces hepiali, a fungal strain isolated from natural C. sinensis, has been used widely as a substitute of C. sinensis in medicine and health food. P. hepiali has been reported to have various pharmaceutical benefits, including triglyceride-lowing activity. However, its effects on triglyceride metabolism in adipocytes remain unknown. The purpose of the present study was to evaluate the effect of P. hepiali mycelia on adipocyte lipolysis and to clarify the underlying mechanisms. METHODS: The fully differentiated 3T3-L1 adipocytes were treated with methanol extract of Paecilomyces hepiali mycelia (PHME). Contents of glycerol released into the culture medium and intracellular triglyceride were measured as indices of lipolysis using glycerol assay kit and Oil red O staining, respectively. Then, effects of PHME on the main lipases or kinases involved in lipolysis regulation were investigated. Protein expression of adipose triglyceride lipase (ATGL) and perilipin, as well as phosphorylation of hormone-sensitive lipase (HSL), AMP-activated protein kinase (AMPK), and mitogen-activated protein kinases (MAPKs) were determined by western blotting. Moreover, nucleosides, important constituents of PHME, were analyzed using high performance liquid chromatography (HPLC). RESULTS: Treatment with PHME led to a significant increase in glycerol release thereby reduced intracellular triglyceride accumulation in fully differentiated adipocytes. PHME upregulated protein kinase (PK) A-mediated phosphorylation of HSL at serine residues of 563 and 660. Meanwhile, PHME treatment also upregulated phosphorylation of extracellular signal-regulated kinase (ERK), and downregulated the protein level of perilipin. Pretreatment with the PKA inhibitor, H89, blunted the PHME-induced lipolysis and the phosphorylation of HSL (Ser 563 and 660). Moreover, pretreatment with ERK inhibitor, PD98059, weakened the PHME-caused glycerol release and downregulation of perilipin expression. HPLC analysis indicated there were adenosine, cordycepin, uridine and vernine in PHME. CONCLUSIONS: Our results showed that PHME significantly induced lipolysis in 3T3-L1 adipocytes, which is mainly mediated by activation of HSL through PKA pathway and by downregulation of perilipin through activation of ERK pathway.

Role of two 5-aminolevulinic acid biosynthetic pathways in heme and secondary metabolite biosynthesis in Amycolatopsis orientalis.

Analysis of the Amycolatopsis orientalis genome revealed that two genes, hemA1 and hemA2, belonging to divergent pathways, were involved in the biosynthesis of 5-aminolevulinic acid. The roles of hemA1 and hemA2 were elucidated via genetic manipulation and metabolite analysis. The disruption of hemA1, encoding the glutamyl-tRNAGlu reductase of the C5 pathway, was essential for cell growth and is used for heme synthesis. Overexpression of hemA1 resulted in elevated vancomycin and ECO-0501 production in Amycolatopsis orientalis, and it was also effective in increasing the production of daptomycin and natamycin in other Streptomycetes. The disruption of hemA2 indicated that it encodes the 5-aminolevulinic acid synthase of the Shemin pathway, serving as a key enzyme for the synthesis of the precursor aminohydroxycyclopentenone unit of ECO-0501. However, hemA2 disruption could not be complemented by the addition of 5-aminolevulinic acid or by the expression of hemA2 outside of the ECO-0501 gene cluster. The synthesis of ECO-0501 was only restored by the insertion of hemA2 at its original locus. The hemA2 gene could partly complement the hemA1 deficiency. Overexpression of hemA1, a key gene from the heme biosynthetic pathway, is proposed here as a new approach to improve the production of secondary metabolites in bacteria, whereas hemA2 plays different roles depending on its pattern of expression.

[Effect of CD106+ Mesenchymal Stem Cell on Bone Marrow Vascular Failure in Patients with Aplastic Anemia].

Objective To investigate the vascularization ability of mesenchymal stem cells(MSCs)and explore its influencing factors in aplastic anemia(AA) patients. Methods MSCs were isolated from the bone marrow of AA patients(AA MSCs) and normal controls(N MSCs) were cultured and then evaluated by flow cytometry and immunofluorescene staining technique.The expression level of vascular cell adhesion molecule-1(CD106) was detected by gene sequencing,and the content and fluorescene intensity of CD106+MSCs was determined by fluorescence-activated cell sorting.The content of CD105+CD106+MSCs in fresh AA bone marrow was measured,followed by the determination of the capability of endothelial differentiation from AA MSCs and N MSCs with immunofluorescene analysis;finally,the capability of CD31+cell differentiation from CD106-blocking N MSCs and its tubular structures formation in matrigel were tested.Results The expression of CD106 in AA patients was defective(decreased by 12.13 times when compared with N MSCs) and the concentration and fluorescene degree of CD106+MSCs was also decreased in AA patients [(28.03±17.71)% vs.(59.61±12.26)%,P=0.000].The content of CD105+CD106+MSCs decreased significantly in the fresh bone marrow [(0.33±0.10)% vs.(2.98±0.46)%,P=0.0005].Besides, the capability of CD31+cell differentiation from AA MSCs was significantly delayed [(13.67±1.50)% vs.(43.24±0.96)%,P=0.0004].Also,the capability of CD31+cell differentiation and tubular structures formation of CD106-blocking N MSCs was also obviously decreased [(26.00±2.65)% vs.(91.78±2.44)%,P=0.000;(13.81±1.98)mm vs.(68.12±6.78)mm,P=0.0015].Conclusion The deficient or decreased expression of CD106+MSCs accelerate the bone marrow vascularization failure in AA patients.

Multiplexed site-specific genome engineering for overproducing bioactive secondary metabolites in actinomycetes.

Actinomycetes produce a large variety of pharmaceutically active compounds, yet production titers often require to be improved for discovery, development and large-scale manufacturing. Here, we describe a new technique, multiplexed site-specific genome engineering (MSGE) via the 'one integrase-multiple attB sites' concept, for the stable integration of secondary metabolite biosynthetic gene clusters (BGCs). Using MSGE, we achieved five-copy chromosomal integration of the pristinamycin II (PII) BGC in Streptomyces pristinaespiralis, resulting in the highest reported PII titers in flask and batch fermentations (2.2 and 2g/L, respectively). Furthermore, MSGE was successfully extended to develop a panel of powerful Streptomyces coelicolor heterologous hosts, in which up to four copies of the BGCs for chloramphenicol or anti-tumour compound YM-216391 were efficiently integrated in a single step, leading to significantly elevated productivity (2-23 times). Our multiplexed approach holds great potential for robust genome engineering of industrial actinomycetes and novel drug discovery by genome mining.