SphK1 deficiency ameliorates the development of atherosclerosis by inhibiting the S1P/S1PR3/Rhoa/ROCK pathway.

BACKGROUND AND AIMS: S1P is an important factor regulating the function of the vascular endothelial barrier. SphK1 is an important limiting enzyme for the synthesis of S1P. However, the role of the SphK1/S1P-mediated vascular endothelial barrier function in atherosclerosis has not been fully revealed. This study explored the roles and mechanisms of SphK1 on atherosclerosis in vivo and in vitro. METHODS: In vivo, ApoE-/- and SphK1-/-ApoE-/- mice were fed a high-fat diet to induce atherosclerosis. In vitro, ox-LDL induced HUVECs to establish a cell model. Aortic histological changes were measured by H&E staining, Oil Red O staining, EVG staining, Sirius scarlet staining, immunofluorescence, and Evans Blue Assay. Western blotting was performed to explore the specific mechanism. RESULTS: We validated that deficiency of SphK1 resulted in a marked amelioration of atherosclerosis, as indicated by the decreased lipid accumulation, inflammatory factors, oxidative stress, aortic plaque area, inflammatory factor infiltration, VCAM-1 expression, and vascular endothelial permeability. Moreover, deficiency of SphK1 downregulated the expression of aortic S1PR3, Rhoa, ROCK, and F-actin. The results of administration with the SphK1 inhibitor PF-543 and the S1PR3 inhibitor VPC23019 in vitro further confirmed the conclusion that deficiency of SphK1 reduced S1P level and S1PR3 protein expression, inhibited Rhoa/ROCK signaling pathway, regulated protein expression of F-actin, improved vascular endothelial dysfunction and permeability, and exerted anti-atherosclerotic effects. CONCLUSIONS: This study revealed that deficiency of SphK1 relieved vascular endothelial barrier function in atherosclerosis mice via SphK1/S1P/S1PR signaling pathway.

Independent and interactive associations of heart rate and obesity with type 2 diabetes mellites: A population-based study.

BACKGROUND: Although obesity and heart rate (HR) were closely related to the prevalence and development of type 2 diabetes mllitus (T2DM), few studies have shown a co-association effect of them on T2DM. We aimed at assessing the interactive effects of HR and obesity with prevalence of T2DM in Chinese population, providing the exact cutpoint of the risk threshold for blood glucose with high HR. MATERIALS AND METHODS: In the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal study (REACTION) cohorts (N = 8398), the relationship between HR and T2DM was explored by linear regression, logistic regression, and restricted cubic spline, and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Interaction terms between HR and body mass index (BMI) and HR and waist circumference (WC) were introduced into the logistic regression model. RESULTS: In those with HR > 88.0 beats/min, fasting plasma glucose and oral glucose tolerance tests were significantly correlated with HR, and the prevalence of T2DM was highly correlated with HR (all p < .05). There were interactive associations of HR and obesity in patients with T2DM with HR < 74 beats/min. CONCLUSION: High HR was in interaction with obesity, associating with prevalence of T2DM. The newly subdivided risk threshold for HR with T2DM might be HR > 88 beats/minute.

The role of SphK/S1P/S1PR signaling pathway in bone metabolism.

There are a large number of people worldwide who suffer from osteoporosis, which imposes a huge economic burden, so it is necessary to explore the underlying mechanisms to achieve better supportive and curative care outcomes. Sphingosine kinase (SphK) is an enzyme that plays a crucial role in the synthesis of sphingosine-1-phosphate (S1P). S1P with paracrine and autocrine activities that act through its cell surface S1P receptors (S1PRs) and intracellular signals. In osteoporosis, S1P is indispensable for both normal and disease conditions. S1P has complicated roles in regulating osteoblast and osteoclast, respectively, and there have been exciting developments in understanding how SphK/S1P/S1PR signaling regulates these processes in response to osteoporosis therapy. Here, we review the proliferation, differentiation, apoptosis, and functions of S1P, specifically detailing the roles of S1P and S1PRs in osteoblasts and osteoclasts. Finally, we focus on the S1P-based therapeutic approaches in bone metabolism, which may provide valuable insights into potential therapeutic strategies for osteoporosis.

Phase separation underlies signaling activation of oncogenic NTRK fusions.

NTRK (neurotrophic tyrosine receptor kinase) gene fusions that encode chimeric proteins exhibiting constitutive activity of tropomyosin receptor kinases (TRK), are oncogenic drivers in multiple cancer types. However, the underlying mechanisms in oncogenesis that involve various N-terminal fusion partners of NTRK fusions remain elusive. Here, we show that NTRK fusion proteins form liquid-like condensates driven by their N-terminal fusion partners. The kinase reactions are accelerated in these condensates where the complexes for downstream signaling activation are also concentrated. Our work demonstrates that the phase separation driven by NTRK fusions is not only critical for TRK activation, but the condensates formed through phase separation serve as organizational hubs for oncogenic signaling.

Mid-infrared Laser Spectroscopy of Jet-Cooled Formic Acid Trimer: Mode-Dependent Line Broadening in the C-O Stretching Region.

Building on recent progress in the vibrational spectroscopy of the formic acid trimer, we present the first high-resolution measurements of the jet-cooled laser absorption spectrum of (HCOOH)3. The spectra of the lowest- and highest-frequency C-O stretching fundamentals are analyzed whereas the third band is not observed, complicated by monomer and dimer absorptions at 1219 cm-1 (8.2 µm). Vibration-rotation parameters are obtained for the band at 1172.31512(68) cm-1 whereas the C-O stretch at 1246.33(5) cm-1 exhibits a significantly larger breadth, allowing only resolution of the coarse PQR structure. Vibrational predissociation can be ruled out, and intramolecular vibrational redistribution mechanisms are discussed, particularly coupling to the concerted proton exchange within the cyclic dimer subunit. Ultimately, the question remains open. The prospects of high-resolution measurements of other trimer bands or isotope substitution experiments, which might assist in revealing the mode-specificity of the underlying broadening mechanisms, are discussed.

Psychiatric disorders and Type 2 diabetes mellitus: A bidirectional Mendelian randomization.

BACKGROUND: Extensive observational evidence put forward the association between psychiatric disorders and type 2 diabetes mellitus (T2DM). However, causal relationships between these two diseases required further research. Thus, we evaluated the bidirection casual effect between five psychiatric disorders and T2DM using two-sample mendelian randomization (MR). METHODS: By selecting single nucleotide polymorphisms associated with T2DM and five psychiatric disorders (attention-deficit hyperactivity disorder (ADHD), major depressive disorder (MDD), schizophrenia, anxiety disorder and panic disorder), a bidirectional two-sample MR was applied to evaluate causality between these diseases. The inverse-variance weighted (IVW) method was used as the primary analysing approach for estimating possible causal effects. MR-Egger and weighted median were also conducted to verify the results. The funnel plot, Cochran's Q test and MR-Egger intercept test were used for sensitivity analyses. In addition, potential mediators were investigated by risk factor analyses. RESULTS: Genetic susceptibilities of ADHD and MDD would increase the risk of T2DM (ADHD: OR = 1.14, 95%CI 1.08-1.20; p = 5.7 × 10 - 6 ; MDD: OR = 1.22, 95%CI 1.09-1.36; p = 0.0004 ). In addition, genetic predisposition to T2DM was also associated with ADHD (OR = 1.09, 95%CI 1.04-1.14; p = 0.0004). Several risk factors of T2DM were implicated in the above causal associations, including smoking, high body mass index, waist-to-hip ratio and elevated serum triglycerides. CONCLUSION: Our studies indicated a causal effect of ADHD and MDD on increasing the risk of T2DM, which was potentially mediated by smoking and obesity-related phenotypes. Meanwhile, we found a causal effect of T2DM on ADHD. Thus, prevention strategies for T2DM should also include mental health and vice versa.

Comparison of UV and UV-LED activated sodium percarbonate for the degradation of O-desmethylvenlafaxine.

As an active metabolite of venlafaxine and emerging antidepressant, O-desmethylvenlafaxine (ODVEN) was widely detected in different water bodies, which caused potential harm to human health and environmental safety. In this study, the comparative work on the ODVEN degradation by UV (254 nm) and UV-LED (275 nm) activated sodium percarbonate (SPC) systems was systematically performed. The higher removal rate of ODVEN can be achieved under UV-LED direct photolysis (14.99%) than UV direct photolysis (4.57%) due to the higher values of photolysis coefficient at the wavelength 275 nm. Significant synergistic effects were observed in the UV/SPC (80.38%) and UV-LED/SPC (53.57%) systems and the former exhibited better performance for the elimination of ODVEN. The degradation of ODVEN all followed the pseudo-first-order kinetics well in these processes, and the pseudo-first-order rate constant (kobs) increased with increasing SPC concentration. Radicals quenching experiments demonstrated that both ·OH and CO3·- were involved in the degradation of ODVEN and the second-order rate constant of ODVEN with CO3·- (1.58 × 108 (mol/L)-1 sec-1) was reported for the first time based on competitive kinetic method. The introduction of HA, Cl-, NO3- and HCO3- inhibited the ODVEN degradation to varying degrees in the both processes. According to quantum chemical calculation, radical addition at the ortho-position of the phenolic hydroxyl group was confirmed to be the main reaction pathways for the oxidation of ODVEN by ·OH. In addition, the oxidation of ODVEN may involve the demethylation, H-abstraction, OH-addition and C-N bond cleavage. Eventually, the UV-LED/SPC process was considered to be more cost-effective compared to the UV/SPC process, although the UV/SPC process possessed a higher removal rate of ODVEN.

Erratum: Long noncoding RNA LINC01435 impedes diabetic wound healing by facilitating YY1-mediated HDAC8 expression.

[This corrects the article DOI: 10.1016/j.isci.2022.104006.].

Long noncoding RNA LINC01435 impedes diabetic wound healing by facilitating YY1-mediated HDAC8 expression.

Abnormal interactions between skin cells play an important role in the dysregulation of diabetic wound recovery. Exosomes are cell-derived lipid nanoparticles that transport messages between cells, and isolating and identifying potential therapeutic noncoding RNAs from exosomes is very important. We demonstrated that treatment with Exos from high glucose-pretreated immortalized human epidermal (HaCaT) cells (HG-Exos) could delay the wound healing process in diabetic mice. Further analysis indicated the Exo-mediated uptake of LINC01435 in recipient human umbilical vein endothelial cells (HUVECs) changes the subcellular localization of the transcription factor Yin Yang 1 (YY1) and cooperates with YY1 to upregulate the expression of histone deacetylases (HDACs)8, resulting in decreased tube formation and ability of HUVECs to migrate, thus angiogenesis was inhibited. These results suggest that LINC01435/YY1/HDAC8 may be an important signaling pathway affecting the recovery of diabetic wounds, which makes it a potential target for the treatment of diabetic foot ulcers.

Phase separation ability and phosphatase activity of the SHP1-R360E mutant.

SHP1 is a non-receptor protein tyrosine phosphatase that is widely expressed in hematopoietic cells such as white blood cells, neutrophils, and immune cells. SHP1 can regulate the occurrence and differentiation of immune cells and plays an important role as a tumor suppressor. Previous studies have suggested that SHP2, the homologous protein of phosphatase SHP1, can undergo liquid-liquid phase separation (LLPS). Therefore, in this study, we investigated if SHP1 is also capable of LLPS. To the best of our knowledge, our study is the first to reveal that SHP1 has the ability to undergo LLPS. In addition, we identified an important residue, SHP1-R360E, that can completely inhibit the LLPS ability of SHP1, but this mutation has no remarkable effect on SHP1's enzymatic activity. This allows us to explore the phosphatase activity and phase separation ability of SHP1 separately, providing a basis for future exploration of the phase separation mechanism of phosphatases.

Highly efficient removal of DEET by UV-LED irradiation in the presence of iron-containing coagulant.

N,N-Diethyl-3-methyl benzoyl amide (DEET) has been detected as an emerging pollutant in various water bodies because of its widespread use as an insect repellent. In this study, the combination of UV-LED275 and iron-containing coagulant (FeCl3) was used for the elimination of DEET in water. It was found that UV-LED275/FeCl3 (98 %) system presented a favorable removal of DEET compared with UV254/FeCl3 (59 %) and UV-LED275/Fe2(SO4)3 (81 %) processes at initial pH 3.5. DEET degradation by both UV-LED275/FeCl3 and UV-LED275/Fe2(SO4)3 processes followed pseudo-first-order kinetics with the calculated pseudo-first-order rate constants (kobs) of 0.0105 and 0.0046 cm2 mJ-1, respectively. The results of ESR analysis and radicals quenching experiments indicated that hydroxyl radicals (OH) and superoxide radicals (O2-) were responsible for DEET degradation in UV-LED275/FeCl3 process, and the former played the major role. An increase in FeCl3 dosage was beneficial to the degradation. In the UV-LED275/FeCl3 process, DEET degradation increased with a decrease in pH from 3.5 to 3.0, whereas it was almost completely suppressed with an increase in pH from 4.3 to 6.3. DEET degradation was almost unchanged after the introduction of NO3-, and it impeded after the addition of humic acid (HA), HCO3-, and SO42-. The plausible degradation pathway mainly involved hydroxylation, cleavage of the C-N bond, acetylation, and dealkylation. Among the disinfection by-products (DBPs) evaluated, UV-LED275/FeCl3 pretreatment generally increased the generation of trichloromethane, chloral hydrate, dichloroacetic acid, and trichloroacetic acid, which implied that further assessment of environmental risk was needed during its practical applications.

Reinforcement of CHH methylation through RNA-directed DNA methylation ensures sexual reproduction in rice.

DNA methylation is an important epigenetic mark that regulates the expression of genes and transposons. RNA-directed DNA methylation (RdDM) is the main molecular pathway responsible for de novo DNA methylation in plants. Although the mechanism of RdDM has been well studied in Arabidopsis (Arabidopsis thaliana), most mutations in RdDM genes cause no remarkable developmental defects in Arabidopsis. Here, we isolated and cloned Five Elements Mountain 1 (FEM1), which encodes RNA-dependent RNA polymerase 2 (OsRDR2) in rice (Oryza sativa). Mutation in OsRDR2 abolished the accumulation of 24-nt small interfering RNAs, and consequently substantially decreased genome-wide CHH (H = A, C, or T) methylation. Moreover, male and female reproductive development was disturbed, which led to sterility in osrdr2 mutants. We discovered that OsRDR2-dependent DNA methylation may regulate the expression of multiple key genes involved in stamen development, meiosis, and pollen viability. In wild-type (WT) plants but not in osrdr2 mutants, genome-wide CHH methylation levels were greater in panicles, stamens, and pistils than in seedlings. The global increase of CHH methylation in reproductive organs of the WT was mainly explained by the enhancement of RdDM activity, which includes OsRDR2 activity. Our results, which revealed a global increase in CHH methylation through enhancement of RdDM activity in reproductive organs, suggest a crucial role for OsRDR2 in the sexual reproduction of rice.

Association Between Formative Assessment and Academic Performance for Undergraduate Medical Students in a Chinese Clinical Skills Training Course.

BACKGROUND Previous research suggests that formative assessment (FA) enhances learning outcomes, but few studies have evaluated its impact on clinical skills training in China. We conducted this study in a clinical skills integral curriculum to further explore the educational value of FA. MATERIAL AND METHODS Sixty undergraduates from the Second Clinical Medical School of the Southern Medical University in 2016 were selected as the experimental group (consecutive FA), and 50 undergraduates in 2015 were selected as the control term (only final summative assessment, SA). Undergraduates in the FA group completed the after-class questionnaire at each lesson. Teachers, teaching content, assessment objectives, and topics are the same in both groups. RESULTS The results of single-factor covariance (ANCOVA) analysis and Cochran-Mantel-Haenszel (CMH) analysis demonstrated that students of the FA group obtained better performance and higher success rates in summative examination than in the SA group. The students with relatively poor grades benefited more from FA, while the performance of students with higher grades was similar between the FA group and SA group. According to the results of questionnaire for students, the satisfaction of students with the course increased gradually, from 84.4% to 93.0%. CONCLUSIONS Proper use of FA is associated with better learning outcomes for students, especially for those with poorer grades. Our results, together with previous research, indicated that the use of FA may be of great benefit to students' academic performance and satisfaction with the clinical skills training curriculum.

Phase Separation of Disease-Associated SHP2 Mutants Underlies MAPK Hyperactivation.

The non-receptor protein tyrosine phosphatase (PTP) SHP2, encoded by PTPN11, plays an essential role in RAS-mitogen-activated protein kinase (MAPK) signaling during normal development. It has been perplexing as to why both enzymatically activating and inactivating mutations in PTPN11 result in human developmental disorders with overlapping clinical manifestations. Here, we uncover a common liquid-liquid phase separation (LLPS) behavior shared by these disease-associated SHP2 mutants. SHP2 LLPS is mediated by the conserved well-folded PTP domain through multivalent electrostatic interactions and regulated by an intrinsic autoinhibitory mechanism through conformational changes. SHP2 allosteric inhibitors can attenuate LLPS of SHP2 mutants, which boosts SHP2 PTP activity. Moreover, disease-associated SHP2 mutants can recruit and activate wild-type (WT) SHP2 in LLPS to promote MAPK activation. These results not only suggest that LLPS serves as a gain-of-function mechanism involved in the pathogenesis of SHP2-associated human diseases but also provide evidence that PTP may be regulated by LLPS that can be therapeutically targeted.

DEET degradation in UV/monochloramine process: Kinetics, degradation pathway, toxicity and energy consumption analysis.

The degradation of N,N-diethyl-meta-toluamide (DEET) in aqueous solution by the UV/monochloramine (UV/NH2Cl) process was examined systematically in this study. DEET was resistant to UV photolysis and chloramination, while the synchronous combination of UV irradiation and NH2Cl can effectively eliminate DEET, which was caused by the generation of hydroxyl radicals and reactive chlorine species. The former played the critical role in DEET degradation, while the contribution of the latter can be ignored. Under all investigated experimental conditions, DEET degradation in the UV/NH2Cl process followed the pseudo-first-order kinetic model. The water quality parameters exerted the complicated impact. Reducing solution pH and raising water temperature both favored the DEET removal. The presence of sulfate, humic acid and fulvic acid accelerated the degradation, while the introduction of bicarbonate and high-concentration chloride retarded the removal. The plausible degradation pathways of DEET in the UV/NH2Cl process were proposed through the combination of QTOF/MS analysis and DFT calculation, and mainly involved in the cleavage of C-N bond, dealkylation, mono- and polyhydroxylation. The acute toxicity of reacted solution underwent a trend of first increasing and then decreasing with the prolonged irradiation time, which can be well illustrated by quantitative structure-activity relationship analysis. Electrical energy per order was employed to determine the energy consumption and the optimal conditions were determined as UV fluence of 369.9-493.2 mJ cm-2 and NH2Cl dosage of 5-20 mg L-1.