Impaired Vps34 complex activity-mediated autophagy inhibition contributes to endothelial progenitor cells damage in the ischemic conditions.

AIMS: Endothelial progenitor cells (EPCs) are widely accepted to be applied in ischemic diseases. However, the therapeutic potency is largely impeded because of its inviability in these ischemic conditions. Autophagy is recognized to be vital in cell activity. Therefore, we explore the role and the mechanism of autophagy in ischemic EPCs. METHODS AND RESULTS: We applied 7d-cultured bone marrow EPCs to investigate the autophagy status under the oxygen and glucose deprivation (OGD) conditions in vitro, mimicking the in-vivo harsh ischemia and anoxia microenvironment. We found increased EPC apoptosis, accompanied by an impaired autophagy activation. Intriguingly, mTOR inhibitor Rapamycin was incapable to reverse this damped autophagy and EPC damage. We further found that autophagy pathway downstream Vps34-Beclin1-Atg14 complex assembly and activity were impaired in OGD conditions, and an autophagy-inducing peptide Tat-Beclin1 largely recovered the impaired complex activity and attenuated OGD-stimulated EPC injury through restoring autophagy activation. CONCLUSIONS: The present study discovered that autophagy activation is inhibited when EPCs located in the ischemia and anoxia conditions. Restoration of Vps34 complex activity obtains sufficient autophagy, thus promoting EPC survival, which will provide a potential target and advance our understanding of autophagy manipulation in stem cell transplantation.

[Analysis of inborn error metabolism in 277 children with autism spectrum disorders from Hainan].

OBJECTIVE: To assess the value of dry blood spot tandem mass spectrometry for the diagnosis of autism spectrum disorder (ASD). METHODS: Peripheral blood samples of 277 autistic children were collected. Their amino acid and carnitine profiles were detected by liquid chromatography tandem mass spectrometry. Urine samples of suspected patients were collected for verification by gas chromatography mass spectrometry. Blood samples were also taken for genetic testing. RESULTS: Of the 277 children with ASD, 19 (6.9%) were suspected to be with inborn error of metabolism (IEM), which included 6 cases with amino acidemia, 9 with organic acidemia and 4 with fatty acidemia. Three cases of phenylketonuria, one case of homocysteinemia, one case of propionemia, one case of methylmalonic acidemia, one case of glutaric acidemia, one case of isovaleric acidemia, one case of argininemia, one case of citrullinemia I and four cases of primary carnitine deficiency were confirmed by genetic testing, which yielded an overall diagnostic rate of 5.1% (14/277). CONCLUSION: Our result has provided further evidence for the co-occurrence of ASD and IEM. Tandem mass spectrometry has a great value for the diagnosis and treatment of ASD in childhood.

Synthesis, Aggregation Induced Emission and Mechanochromic Luminescence of New ß-Diketone Derivatives Bearing Tetraphenylene Moieties.

A series of ß-diketone derivatives bearing tetraphenylene (TPE) moieties were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. All compounds exhibit broad absorption bands between 300 and 450 nm, which are assigned to the 1π-π* transition of the conjugated system mixed intramolecular charge-transfer (ICT) transitions. Meanwhile, the emission of these compounds in solution at room temperature (λ em = 458 ~ 509 nm) can be attributed to the 1π,π*/1ICT state. Introduction of freely rotatable TPE to conventional ß-diketone luminophors quenches their light emissions in the solutions, but endows these molecules with aggregation-induced emission (AIE) characteristics in the condensed phase due to the restriction of intramolecular rotation. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these ß-diketone derivatives can be tuned by the appended substituents, which would be useful for rational design of AIE compounds with high solid state luminescence performance. Furthermore, these AIE-active compounds exhibited distinct piezofluorochromic properties and switched reversibly upon grinding-fuming. Their photophysical properties have been investigated with the aim to provide a basis for elucidating the structure-property correlations and developing new multi-stimuli responsive luminescent materials.

From molecules to materials: computational design of N-containing porous aromatic frameworks for CO2 capture.

Porous aromatic frameworks (PAFs) are novel materials with diamond topology. With the aim of enhancing their CO(2) capture and storage capacity and investigating the effect of nitrogen and/or -COOH decorations on CO(2) adsorption in PAFs, a series of N-containing PAFs were designed based on ab initio results. The interaction energies (E(int)) between CO(2) and each six-membered ring were calculated at the B2PLYP-D2/def2-TZVPP level, then the six-membered rings with high CO(2) -binding affinity were selected and used in the PAFs. To explore the performance of the designed PAFs, the CO(2) uptake, selectivity of CO(2) over CH(4), H(2), and N(2), and the E(int) value of CO(2) in PAFs were investigated by using grand canonical Monte Carlo (GCMC) simulations and ab initio calculations. This work shows that pyridine with one nitrogen atom can provide a strong physisorption site for CO(2), whereas more nitrogen atoms in heterocycles will reduce the interaction, especially at relatively low pressure. PAFs with -COOH groups show high CO(2) capacity. Our work provides an efficient way to understand the adsorption mechanism and a supplemental approach to experimental work.

Theoretical study on the gas phase reaction of allyl chloride with hydroxyl radical.

The reaction of allyl chloride with the hydroxyl radical has been investigated on a sound theoretical basis. This is the first time to gain a conclusive insight into the reaction mechanism and kinetics for important pathways in detail. The reaction mechanism confirms that OH addition to the C=C double bond forms the chemically activated adducts, IM1 (CH2CHOHCH2Cl) and IM2 (CH2OHCHCH2Cl) via low barriers, and direct H-abstraction paths may also occur. Variational transition state model and multichannel RRKM theory are employed to calculate the temperature-, pressure-dependent rate constants. The calculated rate constants are in good agreement with the experimental data. At 100 Torr with He as bath gas, IM6 formed by collisional stabilization is the major products in the temperature range 200-600 K; the production of CH2CHCHCl via hydrogen abstractions becomes dominant at high temperatures (600-3000 K).

Incidence and associated risk factors of congenital hypothyroidism among newborns in Hainan, China: a retrospective study.

OBJECTIVES: This study aims to investigate the incidence and risk factors of congenital hypothyroidism (CH) in newborns in Hainan Province, China, to provide a reference for early and effective prevention strategies. METHODS: Newborns born in Hainan Province from 2017 to 2021 were the subjects of this study. Time-resolved immunofluorescence was used for initial screening and chemiluminescence for confirmatory diagnosis. Based on the diagnosis, newborns were classified into CH and non-CH groups. Statistical analysis was conducted on the initial screening and confirmed CH cases in newborns in Hainan Province, and potential risk factors for CH were explored. RESULTS: From 2017 to 2021, a total of 585,886 newborns were screened, revealing 6,856 initial positive results, 614 positive rescreens, and 420 confirmed CH cases, yielding an incidence rate of 1/1,395 (420/585,886). The annual initial positive screening rate of newborns in Hainan Province showed a rising trend from 2017 to 2021 (p=0.000). No significant differences were found regarding gender (p=0.400) and ethnicity (p=0.836). Multivariate logistic regression analysis indicated that residing in coastal areas, especially those with salt fields (OR=2.151, 95 % CI: 1.364-3.390), was risk factors for the development of CH in newborns. CONCLUSIONS: The incidence of CH in newborns showed a year-on-year increase in Hainan Province from 2017 to 2021. Residing in coastal areas, particularly those with salt fields, was identified as a risk factor for the development of CH.

Genotypic spectrum of α-thalassemia and ß-thalassemia in newborns of the Li minority in Hainan province, China.

Purpose: To explore the genotypes and allele frequencies of α, ß and α+ß thalassemias in Li minorities, which resided in Hainan Province of China for a long time. Methods: In the present study, 1,438 newborns of the Li minority were collected from January 2020 to April 2021. The genotypes of thalassemia were detected by fluorescence PCR and verified by flow-through hybridization PCR analyses. Rare genotypes were detected by restriction fragment length polymorphism electrophoresis and Sanger DNA sequencing. Results: Among 1,438 participants, 1,024 (71.2%) were diagnosed with any kind of thalassemia. Among all thalassemia carriers, 902 (88.09%) subjects were diagnosed with α-thalassemia, and 18 subtypes of α-thalassemia were detected, with the top three genotypes being -α4.2/αα (25.39%), -α3.7/αα (22.62%) and αWSα/αα (16.96%). Thirty-two (3.13%) patients were ß-thalassemia carriers, and 6 types of ß-thalassemia genotypes were detected. The top two genotypes were ßCD41-42/ßN (46.88%) and ß-28/ßN (18.75%). Additionally, 90 (8.79%) cases were α + ß-thalassemia, and the top two genotypes were -α3.7/αα, ßCD41-42/ßN (30.00%) and -α4.2/αα, ßCD41-42/ßN (26.67%). Furthermore, two genotypes (-α4.2/HKαα and ßCD76 GCT > CCT/ßN) were first identified in Hainan Province, and ßCD76 GCT > CCT/ßN was first identified in China. Conclusion: Newborns of Li have a higher prevalence of thalassemia for a long period, and further education on the impact of thalassemia, follow-up studies of the clinical manifestation and treatment and proper intervention methods should be designed to reduce the burden of thalassemia and enhance the quality of life in Li newborns.

CD146 mediates the anti-apoptotic role of Netrin-1 in endothelial progenitor cells under hypoxic conditions.

Modulating the biological status of endothelial progenitor cells (EPCs), such as function and survival, is essential for therapeutic angiogenesis in ischemic vascular disease environments. This study aimed to explore the role and molecular mechanisms underlying Netrin­1 in the viability and angiogenic function of EPCs. EPCs were isolated from the bone barrow of adult C57/BL6 mice. The apoptosis and various functions of EPCs were analyzed in vitro by manipulating the expression of Netrin­1. The TUNEL assay was performed to detect apoptotic EPCs. Cell migration and tube formation assays were performed to detect EPC function. Trypan blue staining was performed to detect cell viability. Western blot analysis was performed to detect the protein expression levels of Netrin­1, CD146 and apoptotic factors. Quantitative PCR analysis was performed to detect the expression levels of Netrin­1 receptors. The results demonstrated that treatment with exogenous Netrin­1 promoted EPC migration and tube formation, whereas transfection with small interfering (si)RNA targeting Netrin­1 exhibited the opposite effects. Exogenous Netrin­1 protected EPCs from hypoxia­induced apoptosis, whereas the interruption of endogenous Netrin­1 enhancement under hypoxia by Netrin­1­siRNA exacerbated the apoptosis of EPCs. Furthermore, CD146, one of the immunoglobulin receptors activated by Netrin­1, was screened for in the present study. Results demonstrated that CD146 did not participate in Netrin­1­promoted EPC function, but mediated the anti­apoptotic effects of Netrin­1 in EPCs. In conclusion, Netrin­1 enhanced the angiogenic function of EPCs and alleviated hypoxia­induced apoptosis, which was mediated by CD146. This biological function of Netrin­1 may provide a potential therapeutic option to promote EPCs for the treatment of ischemic vascular diseases.

Theoretical design and simulation of supramolecular polymer unit based on multiple hydrogen bonds.

The heterocyclic urea of deazapterin (DeAPa) and its protomeric conformers (b, c) with different substituents are selected as the building block for a series of dimers in different configurations. The stabilities of all dimers in various conditions have been investigated by density functional theory. Homodimer of b has more stability than other dimers. Topological analyses certify the coexistence of intermolecular with intramolecular H-bonds. Investigations into frequency demonstrate that all H-bonds show an evident red shift in their stretching vibrational frequencies. Electron donating substituents can provide favorable free energies of the dimer. Solvent effect computations suggest that the dimerization can be favored in weakly polar solvents, such as toluene and chloroform. UV-visible spectra exhibit obvious difference of maximum absorption wavelengths between monomers and dimers, thus may have potential applications for identifying intermolecular H-bonds and calculating association constant of DeAP equilibrium systems in experiments.

The mechanistic study of the hydroxyl radical reaction with trans-2-chlorovinyldichloroarsine.

The trans-2-chlorovinyldichloroarsine (Lewisite) was produced and handled during WWI and WWII as chemical warfare agents. It was very difficult to explore its chemical characterization by experiments ways. The quantum chemical calculations proved to be a precise and harmless method for the toxicological system. In this paper, the gas phase reaction mechanisms of OH radical with trans-2-chlorovinyldichloroarsine (lewisite) were studied by second-order Møller-Plesset perturbation theory (MP2) method. The geometries of reactants, products, complexes, and transition states were optimized at the MP2/6-311++G(d,p) level. To gain more accurate mechanistic knowledge, the single-point energies were calculated using G3 and CCSD(T) method. This reaction exhibited three mechanisms, namely, direct hydrogen abstraction, direct chlorine abstraction, and addition/elimination. Multichannel Rice-Ramsperger-Kassel-Marcus theory and transition-state theory have been carried out for overall and individual rate constants over a wide range of temperatures and pressures. The computational results indicated that addition/elimination reaction is more favorable than direct hydrogen abstraction and direct chlorine abstraction. The major products for the total reaction are AsCl2 and CHClCH2O generated via C(2)-addition/elimination.