Two AIE-Ligand-Based 2-D Luminescent Metal-Organic Frameworks as Fe3+ Sensors

The design and synthesis of high-performance sensors are very important but remain great challenges. In this work, a new aggregation-induced-emission (AIE) molecule 4,4'-(((9H-fluoren-9-ylidene)methylene)bis(4,1-phenylene))dipyridine (L) was successfully synthesized and first developed as a functional ligand to construct two isomorphic metal-organic frameworks (MOFs) [M(L)(OBBA)]n [M2+ = Cd2+ (1), Co2+ (2); H2OBBA = 4,4'-oxybisbenzoic acid]. They adopt [M2(COO)4] flywheel clusters, OBBA2- bridges, and terminal L ligands as building units to form isomorphic 2-D networks with Lewis base active cites (uncoordinated pyridyl N). Both 1 and 2 exhibit excellent water, pH, and thermal stabilities and extremely efficient Fe3+ sensing abilities in the water environment. The quenching constants and detection limits reach the best levels reported so far. The sensing mechanism of 1 and 2 toward Fe3+ is studied in depth, and the difference in their sensing performance is also explained.

Synthetic Biology-based Construction of Unnatural Perylenequinones with Improved Photodynamic Anticancer Activities

The construction of structural complexity and diversity of natural products is crucial for drug discovery and development. To overcome high dark toxicity and poor photostability of natural photosensitizer perylenequinones (PQs) for photodynamic therapy, herein, we aim to introduce the structural complexity and diversity to biosynthesize the desired unnatural PQs in fungus Cercospora through synthetic biology-based strategy. Thus, we first elucidate the intricate biosynthetic pathways of class B PQs and reveal how the branching enzymes create their structural complexity and diversity from a common ancestor. This enables the rational reprogramming of cercosporin biosynthetic pathway in Cercospora to generate diverse unnatural PQs without chemical modification. Among them, unnatural cercosporin A displays remarkably low dark toxicity and high photostability with retention of great photodynamic anticancer and antimicrobial activities. Moreover, it is found that, unlike cercosporin, unnatural cercosporin A could be selectively accumulated in cancer cells, providing potential targets for drug development. Therefore, this work provides a comprehensive foundation for preparing unnatural products with customized functions through synthetic biology-based strategies, thus facilitating drug discovery pipelines from nature.

Reprogramming the Transition States to Enhance C-N Cleavage Efficiency of Rhodococcus opacusl-Amino Acid Oxidase

l-Amino acid oxidase (LAAO) is an important biocatalyst used for synthesizing α-keto acids. LAAO from Rhodococcus opacus (RoLAAO) has a broad substrate spectrum; however, its low total turnover number limits its industrial use. To overcome this, we aimed to employ crystal structure-guided density functional theory calculations and molecular dynamic simulations to investigate the catalytic mechanism. Two key steps were identified: S → [TS1] in step 1 and Int1 → [TS2] in step 2. We reprogrammed the transition states [TS1] and [TS2] to reduce the identified energy barrier and obtain a RoLAAO variant capable of catalyzing 19 kinds of l-amino acids to the corresponding high-value α-keto acids with a high total turnover number, yield (≥95.1 g/L), conversion rate (≥95%), and space-time yields ≥142.7 g/L/d in 12-24 h, in a 5 L reactor. Our results indicated the promising potential of the developed RoLAAO variant for use in the industrial production of α-keto acids while providing a potential catalytic-mechanism-guided protein design strategy to achieve the desired physical and catalytic properties of enzymes.

Photoenzymatic Enantioselective Synthesis of Oxygen-Containing Benzo-Fused Heterocycles

New-to-nature biocatalysis in organic synthesis has recently emerged as a green and powerful strategy for the preparation of valuable chiral products, among which chiral oxygen-containing benzo-fused heterocycles are important structural motifs in pharmaceutical industry. However, the asymmetric synthesis of these compounds through radical-mediated methods is challenging. Herein, a novel asymmetric radical-mediated photoenzymatic synthesis strategy is developed to realize the efficient enantioselective synthesis of oxygen-containing benzo-fused heterocycles through structure-guided engineering of a flavin-dependent 'ene'-reductase GluER. It shows that variant GluER-W100H could efficiently produce various benzoxepinones, chromanone and indanone with different benzo-fused rings in high yields with great stereoselectivities under visible light. Moreover, these results are well supported by mechanistic experiments, revealing that this photoenzymatic process involves electron donor-acceptor complex formation, single electron transfer and hydrogen atom transfer. Therefore, we provide an alternative green approach for efficient chemoenzymatic synthesis of important chiral skeletons of bioactive pharmaceuticals.

Structural Insight into the Catalytic Mechanisms of an L-Sorbosone Dehydrogenase

L-Sorbosone dehydrogenase (SNDH) is a key enzyme involved in the biosynthesis of 2-keto-L-gulonic acid , which is a direct precursor for the industrial scale production of vitamin C. Elucidating the structure and the catalytic mechanism is essential for improving SNDH performance. By solving the crystal structures of SNDH from Gluconobacter oxydans WSH-004, a reversible disulfide bond between Cys295 and the catalytic Cys296 residues is discovered. It allowed SNDH to switch between oxidation and reduction states, resulting in opening or closing the substrate pocket. Moreover, the Cys296 is found to affect the NADP+ binding pose with SNDH. Combining the in vitro biochemical and site-directed mutagenesis studies, the redox-based dynamic regulation and the catalytic mechanisms of SNDH are proposed. Moreover, the mutants with enhanced activity are obtained by extending substrate channels. This study not only elucidates the physiological control mechanism of the dehydrogenase, but also provides a theoretical basis for engineering similar enzymes.

Different dexamethasone doses in the perioperative period improve short-term outcomes of total hip arthroplasty: a randomized controlled trial

OBJECTIVE

This study aimed to evaluate the efficacy of different dexamethasone doses in the perioperative period of total hip arthroplasty (THA).

PATIENTS AND METHODS

We randomly divided 180 patients into three groups: three perioperative saline injections (Group A, placebo); two perioperative doses of 15 mg dexamethasone plus a postoperative saline injection at 48 h (Group B); and three perioperative doses of dexamethasone (10 mg) (Group C). Primary outcomes were postoperative pain at rest and while walking. We also recorded consumption of analgesics and antiemetics, incidence of postoperative nausea and vomiting (PONV), C-reactive protein (CRP) and interleukin-6 (IL-6) levels, postoperative length of stay (p-LOS), range of motion (ROM), nausea, Identity-Consequence-Fatigue-Scale (ICFS), and severe complications (e.g., incidence of surgical site infection, SSI and gastrointestinal bleeding, GIB).

RESULTS

Group B and C had significantly lower pain scores at rest than Group A on postoperative day 1. Group B and C also had significantly lower dynamic pain score, CRP, and IL-6 than Group A on postoperative day 1, 2, and 3. Patients in Group B and C had lower PONV incidence, reduced use of analgesics and antiemetics, improved ROM, shorter p-LOS, lower VAS nausea score, and lower ICFS than Group A patients. On postoperative day 3, patients in Group C had significantly lower dynamic pain and ICFS scores, IL-6, and CRP than Group B patients, as well as higher ROM. None of the groups exhibited SSI or GIB.

CONCLUSIONS

Dexamethasone provides short-term advantages in reducing pain, PONV, inflammation, and ICFS, and increasing ROM in the early postoperative period after THA. Dexamethasone efficacy in reducing post-THA pain, inflammation, and PONV at 10 mg and 15 mg is similar during the first 48 h. Dexamethasone (30 mg) divided into three 10 mg doses was superior to two doses (15 mg) in reducing pain, inflammation, and ICFS, as well as in increasing ROM on postoperative day 3.

The efficacy of aggressive warming combined with tranexamic acid during total hip arthroplasty: a single-center retrospective study from southern China

OBJECTIVE

The aim of the study was to evaluate the efficacy of aggressive warming combined with tranexamic acid (TXA) during total hip arthroplasty (THA).

PATIENTS AND METHODS

A total of 832 patients who underwent THA from October 2013 to June 2019 were divided into three groups according to the order of admission. There were 210 patients from October 2013 to March 2015 in group A, 302 patients from April 2015 to April 2017 in group B, and 320 patients from May 2017 to June 2019 in group C. Group A was the control group and was not given any measures. Group B was administered intravenously with 15 mg/kg TXA before skin incision and 3 h later without aggressive warming. Group C was administered intravenously with 15 mg/kg TXA before skin incision and 3 h later with aggressive warming. We evaluated the differences in the intraoperative blood loss, changes in core body temperature of patients at different stages during the operation, postoperative drainage, hidden blood loss, transfusion rate, drop of hemoglobin (Hb) on postoperative day 1 (POD1), prothrombin time (PT) of POD1, average hospitalization day, and complications.

RESULTS

There were statistically significant differences among the three groups during the intraoperative blood loss, intraoperative changes in core body temperature, postoperative drainage, hidden blood loss, blood transfusion rate, drop of Hb on POD1 and average hospital stay (p<0.05). There was no statistical difference in PT on POD1 and the incidence of complications (p>0.05).

CONCLUSIONS

Aggressive warming combined with TXA can significantly reduce the blood loss and transfusion rate of THA, and accelerate the recovery. We also observed that it does not increase the postoperative complications.

[Characteristics and risk factors of spinal epidural hematoma after unilateral biportal endoscopic lumbar interbody fusion]

Objective: To investigate the incidence, characteristics and risk factors of spinal epidural hematoma after unilateral biportal endoscopic (UBE) lumbar spine surgery. Methods: The clinical data of 105 patients who underwent lumbar spine surgery under UBE in Guangdong Provincial People's Hospital from February 2020 to March 2021 were retrospectively reviewed. Of the patients, 48(45.7%) were male and 57(54.3%) were female, the mean age was (60.1±11.4) years (ranged 26 to 85 years). The MRI images at the third day post-surgery were observed, and the occurrence of hematoma was counted. Patients were assigned to normal group and hematoma group based on the presence of hematoma or not. The related clinical indicators of each patients were collected and used for comparison between two different groups. Logistic stepwise regression model was used to analyze whether each index was a risk factor for hematoma after the UBE lumbar fusion. Results: The total hematoma incidence rate was 28.6%(30/105), the symptomatic hematoma rate was 6.7%(7/105), and the hematoma reoperation rate was 0.9%(1/105). Univariate logistic regression analysis showed that hypertension (OR=3.368, 95%CI: 1.389-8.171), diabetes (OR=3.589, 95%CI: 1.230-10.476), admission systolic blood pressure>140 mmHg (1 mmHg=0.133 kPa,OR=3.687, 95%CI: 1.493-9.017), platelets<200×10⁹/L (OR=0.300, 95%CI: 0.119-0.785), preoperative blood calcium<2.25 mmol/L (OR=0.340, 95%CI: 0.142-0.818), spinal stenosis grade D (OR=4.462, 95%CI: 1.810-10.996) were possible risk factors for spinal hematoma after UBE lumbar fusion. Multivariate logistic regression analysis showed that admission blood pressure systolic blood pressure>140 mmHg (OR=3.788, 95%CI:1.055-13.606), preoperative blood calcium<2.25 mmol/L (OR=78.544, 95%CI:3.895-1 584.058) and spinal stenosis grade D (OR=3.698, 95%CI:1.110-12.325) were risk factors for spinal hematoma after UBE lumbar fusion (all P<0.05). Conclusion: The types of spinal canal hematoma after UBE lumbar fusion include localized and extended type. The risk factors for hematoma include high systolic blood pressure on admission, low preoperative blood calcium and severe spinal stenosis.

[IRE1α deficiency impairs autophagy in chondrocytes by upregulating calcium homeostasis endoplasmic reticulum protein]

OBJECTIVE

To explore the mechanism by which inositol-requiring enzyme-1α (IRE1α) regulates autophagy function of chondrocytes through calcium homeostasis endoplasmic reticulum protein (CHERP).

METHODS

Cultured human chondrocytes (C28/I2 cells) were treated with tunicamycin, 4μ8c, rapamycin, or both 4μ8c and rapamycin, and the expressions of endoplasmic reticulum (ER) stress- and autophagy-related proteins were detected with Western blotting. Primary chondrocytes from ERN1 knockout (ERN1 CKO) mice and wild-type mice were examined for ATG5 and ATG7 mRNA expressions, IRE1α and p-IRE1α protein expressions, and intracellular calcium ion content using qPCR, Western blotting and flow cytometry. The effect of bafilomycin A1 treatment on LC3 Ⅱ/LC3 Ⅰ ratio in the isolated chondrocytes was assessed with Western blotting. Changes in autophagic flux of the chondrocytes in response to rapamycin treatment were detected using autophagy dual fluorescent virus. The changes in autophagy level in C28/I2 cells overexpressing CHERP and IRE1α were detected using immunofluorescence assay.

RESULTS

Tunicamycin treatment significantly up-regulated ER stress-related proteins and LC3 Ⅱ/LC3 Ⅰ ratio and down-regulated the expression of p62 in C28/I2 cells (P < 0.05). Rapamycin obviously up-regulated LC3 Ⅱ/LC3 Ⅰ ratio (P < 0.001) in C28/I2 cells, but this effect was significantly attenuated by co-treatment with 4μ8c (P < 0.05). Compared with the cells from the wild-type mice, the primary chondrocytes from ERN1 knockout mice showed significantly down-regulated mRNA levels of ERN1 (P < 0.01), ATG5 (P < 0.001) and ATG7 (P < 0.001), lowered or even lost expressions of IRE1α and p-IRE1α proteins (PP < 0.01), and increased expression of CHERP (P < 0.05) and intracellular calcium ion content (P < 0.001). Bafilomycin A1 treatment obviously increased LC3 Ⅱ/ LC3 Ⅰ ratio in the chondrocytes from both wild-type and ERN1 knockout mice (P < 0.01 or 0.05), but the increment was more obvious in the wild-type chondrocytes (P < 0.05). Treatment with autophagy dual-fluorescence virus resulted in a significantly greater fluorescence intensity of LC3-GFP in rapamycin-treated ERN1 CKO chondrocytes than in wild-type chondrocytes (P < 0.05). In C28/I2 cells, overexpression of CHERP obviously decreased the fluorescence intensity of LC3, and overexpression of IRE1α enhanced the fluorescence intensity and partially rescued the fluorescence reduction of LC3 caused by CHERP.

CONCLUSION

IRE1α deficiency impairs autophagy in chondrocytes by upregulating CHERP and increasing intracellular calcium ion content.

[Benefits and risks of prolonged dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent in patients with stable coronary artery disease and diabetes]

Objective: To compare the efficacy and safety of prolonged dual antiplatelet therapy (DAPT>1 year) in patients with stable coronary artery disease (CAD) and diabetes who were event-free at 1 year after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) in a large and contemporary PCI registry. Methods: A total of 1 661 eligible patients were selected from the Fuwai PCI Registry, of which 1 193 received DAPT>1 year and 468 received DAPT ≤1 year. The primary endpoint was major adverse cardiac and cerebrovascular event (MACCE) and Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding, MACCE was defined as a composite of all-cause death, myocardial infarction or stroke. Multivariate Cox regression analysis and inverse probability of treatment weighting (IPTW) Cox regression analysis were performed. Results: After a median follow-up of 2.5 years, patients who received DAPT>1 year were associated with lower risks of MACCE (1.4% vs. 3.2%; hazard ratio (HR) 0.412, 95% confidence interval (CI) 0.205-0.827) compared with DAPT ≤1 year, which was primarily caused by the lower all-cause mortality (0.1% vs. 2.6%; HR 0.031, 95%CI 0.004-0.236). Risks of cardiac death (0.1% vs. 1.5%; HR 0.051, 95%CI 0.006-0.416) and definite/probable ST (0.3% vs. 1.1%; HR 0.218, 95%CI 0.052-0.917) were also lower in patients received DAPT>1 year than those received DAPT ≤ 1 year. No difference was found between the two groups in terms of BARC type 2, 3, or 5 bleeding (5.3% vs. 4.1%; HR 1.088, 95%CI 0.650-1.821). Conclusions: In patients with stable CAD and diabetes who were event-free at 1 year after PCI with DES, prolonged DAPT (>1 year) provides a substantial reduction in ischemic cardiovascular events, including MACCE, all-cause mortality, cardiac mortality, and definite/probable ST, without increasing the clinically relevant bleeding risk compared with ≤ 1-year DAPT. Further well-designed, large-scale randomized trials are needed to verify the beneficial effect of prolonged DAPT in this population.

Insight into the broadened substrate scope of nitrile hydratase by static and dynamic structure analysis

Mutations of two gating residues at the substrate access tunnel entrance direct the substrate scope of NHases.

Effects of exogenous α-(1,4)-amylase on the utilisation of corn starch and glucose metabolism in broiler chickens

Starch is the most important energy source in corn-based diets for broiler chickens, however, some proportion of dietary starch may be partially digested, leading to a decrease in feed utilisation. Therefore, supplementing exogenous amylase might be a feasible way to improve the utilisation of dietary starch for poultry. This study investigated the effects of exogenous α-(1,4)-amylase supplementation on the utilisation of corn starch and glucose metabolism in broiler chickens. A total of 560, 4-d-old Arbour Acres plus male broiler chicks were randomly divided into five treatment groups and fed a corn-soybean meal diet supplemented with 0, 400, 600, 800 and 1 200 U/kg α-(1,4)-amylase to evaluate growth. The growth performance, nutrient digestibility coefficients, digestive enzyme activity, glucose transporter transcription and cecal microbiota composition were evaluated in this study. Starch digestibility coefficient showed a quadratic response to α-(1,4)-amylase at 14 d and 42 d (P < 0.05). However, the endogenous α-amylase activity in jejunal content was linearly decreased (P = 0.045). Also, exogenous α-(1,4)-amylase linearly decreased ileal Na+-dependent glucose and galactose transporter 1 mRNA expression at 42 d (P < 0.001). Exogenous α-(1,4)-amylase generated higher insulin and glucagon serum concentrations in fasted birds (P < 0.05) and following re-feeding for 2 h (P < 0.001). BW gain and feed intake were strongly positively correlated with starch digestibility coefficient at both 14 d (r = 0.87) and 42 d (r = 0.91); whereas, the relative weight of the gizzard was weakly negatively correlated with starch digestibility coefficient (r = -0.35). The relative abundance of Unclassified_Bacillaceae was moderately positively correlated (r > 0.50) while Oscillospira, Ornithobacterium and Unclassified_Barnesiellaceae were moderately negatively correlated (-0.50 < r -0.39) with starch digestibility coefficient. In conclusion, exogenous α-amylase modulates metabolic function by increasing insulin and glucagon concentrations, influenced gut microbiota which may impact starch digestibility in the jejunum and ileum. The results of this study showed that excessive addition of exogenous α-(1,4)-amylase was not beneficial for the utilisation of starch in broiler chickens. Supplement more than 600 U/kg α-(1,4)-amylase inhibited glucose transporters, decreases the coefficients of starch and organic matter digestibility in the small intestine to a varying degree, thereby limiting the growth performance of broiler chickens.

A fowl adenovirus serotype 4 (FAdV-4) Fiber2 subunit vaccine candidate provides complete protection against challenge with virulent FAdV-4 strain in chickens

Hypervirulent fowl adenovirus serotype 4 (FAdV-4)-induced hepatitis-hydropericardium syndrome (HHS) with high mortality causes huge economic losses to the poultry industry worldwide. However, commercially available vaccines against FAdV-4 infection remain scarce. Here, we prepared a subunit vaccine candidate derived from the bacterially expressed recombinant Fiber2 protein (termed as rFiber2 subunit vaccine) of FAdV-4 GZ-QL strain (a hypervirulent strain isolated in Guizhou province) and a recombinant plasmid pVAX1-Fiber2 as DNA vaccine candidate (termed as Fiber2 DNA vaccine). The immune effects of different dosages (50, 100, and 150 μg) of these were evaluated through immunization and challenge studies in chickens. Three injections of the rFiber2 subunit vaccine or the Fiber2 DNA vaccine induced robust humoral and cellular immune responses in chickens, which was assessed based on the secretion of high-level neutralizing antibodies, Th1- (IL-2, IFN-γ) and Th2-type cytokines (IL-4, IL-6). Importantly, the efficacy of the rFiber2 subunit vaccine was significantly higher (80 %-100 %) compared with the Fiber2 DNA vaccine (50 %-60 %) and a commercial inactivated vaccine (80 %). Collectively, these results suggest that the rFiber2 subunit and Fiber2 DNA vaccine candidate induced remarkable humoral and cellular immune responses, while the rFiber2 subunit vaccine candidate possesses better potential in the fight against FAdV-4 infection, laying foundations for the effective control of HHS in chickens.

Implications of ESC-high tthrombotic risk features and ARC-high bleeding risk criteria on clinical outcomes in all-comer patients undergoing PCI

Background

High thrombotic risk (HTR) and high bleeding risk (HBR) features after PCI can occur in the same patient. The individualized risks of ischemic vs. bleeding events are needed to be considered for determining the optimal duration of DAPT. We aimed to evaluate long-term ischemic and bleeding outcomes in patients who are at both HTR and HBR after DES implantation.

Methods

All consecutive patients who underwent PCI with DES were prospectively enrolled in Fuwai PCI Registry. HTR criteria based on 2017 ESC DAPT guidelines were defined as: diffuse multivessel diabetic CAD patients, chronic kidney disease, ≥3 stents implanted, ≥3 stents lesions treated, bifurcation with two stents implanted, total stent length &gt;60 mm, or chronic total occlusion. Patients were defined as HBR if they met at least 1 major or 2 minor Academic Research Consortium (ARC)-HBR criteria. The primary ischemic outcome was major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction, target vessel revascularization and stent thrombosis.

Results

Among 10,167 patients, 4,430 (43.6%) qualified as HTR. The rate of HBR patients was significantly higher in the HTR group than in the non-HTR group (18.9% versus 12.2%, P&lt;0.001). Compared to those having non-HTR., Patients with ESC-HTR had higher 30-month rates of MACE (hazard ratio [HR] adjust: 1.56, 95% confidence interval [CI]: 1.34–1.82; P&lt;0.001), device-oriented composite endpoint (composite of cardiac death, target-vessel MI, and target lesion revascularization) (HRadjust: 1.52 [1.27–1.83]; P&lt;0.001), cardiac mortality, myocardial infarction, stent thrombosis, any revascularization, and stroke, without increasing the risk of BARC type 2, 3, or 5 bleeding. MACE rates at 30 months among those without HTR or HBR, HBR alone, HTR alone, and both HTR and HBR were 5.1%, 6.0%, 8.3%, and 8.8%, respectively (P&lt;0.001). Associations between HTR and adverse events were similar in HBR and no HBR groups, without evidence of interaction; however, adverse event rates were highest among subjects with both HBR and HTR.

Conclusions

A combination of ESC-HTR and ARC-HBR may increase the risk of long-term ischemic events, including cardiac mortality, emphasizing the importance of considering the net clinical benefit including high ischemic and bleeding features. Our data suggest that ESC-HTR criteria was useful for stratifying post-PCI patients into risk strata for future ischemic events.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Beijing Municipal Health Commission (Grant No. 2020-1-4032) Kaplan-Meier event rates

Xinnaokang improves cecal microbiota and lipid metabolism to target atherosclerosis

This study aims to explore the potential mechanisms of Xinnaokang in atherosclerosis treatment. Firstly, the active components of Xinnaokang were analysed by HPLC, which contains ginsenoside Rg1, puerarin, tanshinone, notoginsenoside R1, ammonium glycyrrhizate and glycyrrhizin. Network pharmacology analysis showed there were 145 common targets of Xinnaokang, including the chemical stress, lipid metabolite, lipopolysaccharide, molecules of bacterial origin, nuclear receptor and fluid shear stress pathways. Then, the animal experiment showed that Xinnaokang reduced the body weight and blood lipid levels of atherosclerotic mice. Vascular plaque formation was increased in atherosclerotic mice, which was markedly reversed by Xinnaokang. In addition, Xinnaokang reduced CAV-1 expression and increased ABCA1, SREBP-1 and LXR expressions in the vasculature. Xinnaokang promoted SREBP-2 and LDLR expressions in the liver but decreased IDOL and PCSK9 expressions, indicating that Xinnaokang regulated lipid transport-related protein expression. Cecal microbiota diversity was reduced in atherosclerotic mice but increased after Xinnaokang treatment. Xinnaokang treatment also improved gut microbiota communities by enriching Actinobacteria, Bifidobacteriales and Bifidobacteriaceae abundances. Metabolic profile showed that Xinnaokang significantly reduced homogentisate, phenylacetylglycine, alanine and methionine expressions in the liver of atherosclerotic mice. Xinnaokang effectively alleviated atherosclerosis, and this effect might be linked with the altered features of the liver metabolite profiles and cecal microbiota.

Improving the catalytic behaviors of Lactobacillus-derived fructansucrases by truncation strategies

Fructansucrases (FSs), including inulosucrase (IS) and levansucrase (LS), are the members of the Glycoside Hydrolase family 68 (GH68) enzymes. IS and LS catalyze the polymerization of the fructosyl moiety from sucrose to inulin- and levan-type fructans, respectively. Lactobacillus-derived FSs have relatively extended N- and C-terminal sequences. However, the functional roles of these sequences in their enzymatic properties and fructan biosynthesis remain largely unknown. Limosilactobacillus reuteri (basionym: Lactobacillus reuteri) 121 could produce both IS and LS, abbreviated as Lare121-IS and Lare121-LS, respectively. In this study, it was found that the terminal truncation displayed an obvious effect on their activities and the N-terminal truncated variants, Lare121-ISΔ177-701 and Lare121-LSΔ154-686, displayed the highest activities. Melting temperature (T_m) and the thermostability at 50 °C were measured to evaluate the stability of various truncated versions, revealing the different effects of N-terminal on the stability. The average molecular weight and polymerization degree of the fructans produced by different truncated variants did not change considerably, indicating that N-terminal truncation had low influence on fructan biosynthesis. In addition, it was found that N-terminal truncation could also improve the activity of other reported FSs from Lactobacillus species.

Optimal strategy for antiplatelet therapy after coronary drug-eluting stent implantation in high-risk "TWILIGHT-like" patients with diabetes mellitus

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Chinese College of Cardiovascular Physicians, CS Optimizing Antithrombotic Research Fund (Grant No. BJUHFCSOARF201801-01), the National Key Research and Development Program of China (Grant No. 2018YFC1315602), the Beijing Municipal Health Commission (Grant No. 2020-1-4032), the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (Grant No. 2016-I2M-1-009), and the National Natural Science Foundation of China (Grant No. 81870277).

Background

Patients with diabetes mellitus (DM) are known to be at high-risk for both ischemic and bleeding complications post-percutaneous coronary intervention (PCI). The ischemic benefit versus bleeding risk associated with extended dual antiplatelet therapy (DAPT) in high-risk "TWILIGHT-like" patients with diabetes mellitus after PCI has not been established.

Methods

All consecutive high-risk patients fulfilling the "TWILIGHT-like" criteria undergoing PCI from January 2013 through December 2013 were identified from prospective Fuwai PCI Registry. High-risk "TWILIGHT-like" patients were defined by at least 1 clinical and 1 angiographic feature based on TWILIGHT trial selection criteria. The present analysis evaluated 3425 diabetics patients with concomitant high-risk angiographic features who were event-free at 1 year after PCI. Median follow-up was 2.4 years. The primary effectiveness endpoint was a composite of death, myocardial infarction, or stroke (termed major adverse cardiac and cerebrovascular events) and primary safety endpoint was clinically relevant bleeding according to Bleeding Academic Research Consortium type 2, 3, or 5.

Results

On inverse probability of treatment weighting (IPTW) analysis, prolonged-term (&gt;1-year) DAPT with aspirin and clopidogrel decreased the risk of primary effectiveness endpoint compared with shorter (≤1-year) DAPT (1.8% vs. 4.3%; hazard ratio [HR]IPTW: 0.381; 95% confidence interval [CI]: 0.252-0.576; P &lt; 0.001) and reduced cardiovascular death (0.1% vs. 1.8%; HRIPTW: 0.056 [0.016-0.193]). Prolonged DAPT was also associated with a reduced risk of definite/probable stent thrombosis (0.2% vs. 0.7%; HRIPTW: 0.258 [0.083-0.802]), and non-significantly lower rate of myocardial infarction (0.5% vs. 0.8%; HRIPTW: 0.676 [0.275-1.661]). There was no significant difference between groups in clinically relevant bleeding (1.1% vs. 1.1%; HRIPTW: 1.078 [0.519-2.241]; P = 0.840). Similar results were observed in multivariable Cox proportional hazards regression model.

Conclusion

Among high-risk PCI patients with diabetes mellitus without an adverse event through 1 year, extending DAPT &gt; 1-year significantly reduced the risk of major adverse cardiac and cerebrovascular events without an increase in clinically relevant bleeding, suggesting that such high-risk diabetic patients may be good candidates for long-term DAPT.

Abstract Figure.

Impact of ESC-endorsed high ischemic risk features and ARC-high bleeding risk criteria on clinical outcomes in all-comer patients undergoing PCI

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Beijing Municipal Health Commission (Grant number: 2020-1-4032).

Background

Whether the underlying risk of high bleeding risk (HBR) influences the relationship of high ischemic risk (HIR) features with adverse events after drug-eluting stent implantation remains unclear. The purpose of this study was to evaluate (1) the prognostic effect of ESC guideline-endorsed HIR features on long-term clinical outcomes and (2) whether the outcomes of HIR versus non-HIR features vary by HBR status.

Methods

Ten thousand one hundred sixty-seven consecutive patients who underwent percutaneous coronary intervention between January 2013 and December 2013 were prospectively enrolled in Fuwai PCI Registry. Patients who are at HIR were defined as: diffuse multivessel disease in diabetic patients, chronic kidney disease, at least three stents implanted, at least three stents lesions treated, bifurcation with two stents implanted, total stent length &gt; 60 mm, or treatment of chronic total occlusion. The definition of HBR was based on the Academic Research Consortium (ARC) for HBR criteria. The primary ischemic outcome was major adverse cardiac event (MACE), a composite of cardiac death, myocardial infarction, target vessel revascularization and stent thrombosis. The primary bleeding outcome was clinically relevant bleeding, defined according to Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding.

Results

With a 2.4-year median follow-up, 4430 patients (43.6%) having HIR experienced a significantly higher risk of MACE (hazard ratio [HR] adjust : 1.56, 95% confidence interval [CI]: 1.34–1.82; P &lt; 0.001) and device-oriented composite endpoint (composite of cardiac death, target-vessel MI, and target lesion revascularization) (HRadjust : 1.52 [1.27–1.83]; P &lt; 0.001), compared to those having non-HIR. The risk of clinically relevant bleeding did not differ between groups (HRadjust : 0.85 [0.66–1.08]; P = 0.174). Associations between HIR and adverse events were similar in HBR and non-HBR groups, without evidence of interaction (all P interaction &gt; 0.05); however, adverse event rates were highest among subjects with both HIR and HBR.

Conclusions

ESC guideline-endorsed HIR was associated with significantly increased risk of MACE without any significant differences in clinically relevant bleeding. The presence of ARC-HBR does not emerge as a modifier of cardiovascular risk for patients at HIR, suggesting more potent and longer antiplatelet therapy may be beneficial for this patient population.

Long-term ischemic and bleeding risk with extended dual antiplatelet therapy after PCI in patients with 2018 ESC/EACTS myocardial revascularization guideline-endorsed high thrombotic risk features

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Beijing Municipal Health Commission (Grant number: 2020–1-4032)

Background

The ischemic/bleeding trade-off of continuing dual antiplatelet therapy (DAPT) beyond 1 year after PCI for patients with high thrombotic risk (HTR) as endorsed by 2018 ESC/EACTS myocardial revascularization guidelines remain unknown. We sought to evaluate the benefits and harms of DAPT with aspirin and clopidogrel beyond 1 year versus ≤ 1-year DAPT on long-term clinical outcomes after PCI with DES among ESC/EACTS guideline-endorsed HTR patients that are event-free at 1 year follow-up, using a prospective, real-world registry.

Methods

Patients undergoing coronary stenting between January 2013 and December 2013 from the prospective Fuwai registry were defined as HTR if they met at least 1 ESC/EACTS guideline-endorsed HTR criteria with at least 1 of the following characteristics: diffuse (lesion length ≥ 20 mm) multivessel disease in diabetic patients, CKD (estimated glomerular filtration rate &lt; 60 mL/min), ≥ 3 stents implanted, ≥ 3 lesions treated, bifurcation with 2 stents implanted, total stent length &gt; 60 mm, treatment of CTO, and history of STEMI. A total of 4578 patients who were at HTR and were events free at 1 year after the index procedure were evaluated. The primary efficacy outcome was major adverse cardiac and cerebrovascular events (MACCE) (composite of all-cause death, myocardial infarction, or stroke).

Results

Median follow-up period was 2.4 years. &gt; 1-year DAPT with clopidogrel and aspirin significantly reduced the risk of MACCE compared with ≤ 1-year DAPT (1.9% vs. 4.6%; hazard ratio (HR): 0.38; 95% confidence interval (CI): 0.27–0.54; P &lt; 0.001), driven by a reduction in all-cause death (0.2% vs. 3.0%; HR, 0.07; 95% CI, 0.03–0.15). Cardiac death and definite/ probable stent thrombosis also occurred less frequently in prolonged DAPT group. Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 bleeding occurred similarly between both groups (1.1% vs. 0.9%; HR, 1.11; 95% CI, 0.58–2.13; P = 0.763). Similar results were found using multivariable Cox model, propensity score-matched, and inverse probability of treatment weighting analysis.

Conclusions

Among patients with ESC-endorsed HTR who were free from major ischemic or bleeding events 1 year after coronary stenting, continued DAPT beyond 1 year might offer better effectiveness in terms of atherothrombotic events and comparable safety in terms of clinically relevant bleeding compared with ≤ 1-year DAPT. ESC-HTR criteria is an important parameter to take into account in tailoring DAPT prolongation.

Parsing the microRNA genetics basis regulating skeletal muscle fiber types and meat quality traits in pigs

Muscle fibers are closely related to human diseases and livestock meat quality. However, the genetics basis of microRNAs (miRNAs) in regulating muscle fibers is not completely understood. In this study, we constructed the whole genome-wide miRNA expression profiles of porcine fast-twitch muscle [biceps femoris (Bf)] and slow-twitch muscle [soleus (Sol)], and identified hundreds of miRNAs, including four skeletal muscle-highly expressed miRNAs, ssc-miR-378, ssc-let-7f, ssc-miR-26a, and ssc-miR-27b-3p. Moreover, we identified 63 differentially expressed (DE) miRNAs between biceps femoris vs. soleus, which are the key candidate miRNAs regulating the skeletal muscle fiber types. In addition, we found that the expression of DE ssc-miR-499-5p was significantly correlated to the expression of Myoglobin (r = 0.6872, P < 0.0001) and Myosin heavy chain 7 (MYH7; r = 0.5408, P = 0.0020), and pH_45 min (r = 0.3806, P = 0.0380) and glucose content (r = -0.4382, P = 0.0154); while the expression of DE ssc-miR-499-3p was significantly correlated to the expression of Myoglobin (r = 0.5340, P = 0.0024) and pH_45 min (r = 0.4857, P = 0.0065). Taken together, our data established a sound foundation for further studies on the regulatory mechanisms of miRNAs in skeletal muscle fiber conversion and meat quality traits in livestock, and could provide a genetic explanation of the role of miRNAs in human muscular diseases.

Efficacy of laparoscopic gastric bypass vs laparoscopic sleeve gastrectomy in treating obesity combined with type-2 diabetes

OBJECTIVE

This prospective study compared the efficacy and safety of laparoscopic gastric bypass and laparoscopic sleeve gastrectomy in treating overweight and obese patients with BMI>28 kg/m² and type-2 diabetes.

METHODS

Patients were randomized into a gastric bypass group (n = 77) or a gastrectomy group (n = 80). The surgery time, intraoperative blood loss, recovery time, and hospitalization time were collected. BMI, waistline, hipline, C-peptide level, insulin resistance index (HOMA-IR), and their blood and lipid profile were also measured.

RESULTS

Surgery time and blood loss were significantly higher in the gastrectomy group, when compared to the gastric bypass group (P < 0.05). In both groups, the levels of BMI, waist circumference and hip circumference (but not their ratio) gradually and significantly decreased after surgery compared with baseline (P < 0.05), and no significant difference was found between these two groups. The C-peptide level, HOMA-IR, fasting blood glucose, 2-hour postprandial blood glucose and glycosylated haemoglobin gradually and significantly decreased after surgery compared with the values before treatment (P < 0.05). The levels of total cholesterol, triglyceride, LDL, and monocyte chemoattractant protein-1 were also lower after surgery in both groups, while HDL and glucagon-like peptide-1 were significantly higher after surgery compared with the values before treatment (P < 0.05). However, no significant difference was found between these two groups of patients.

CONCLUSION

Both laparoscopic gastric bypass and laparoscopic sleeve gastrectomy improved the BMI and diabetic conditions of overweight/obese diabetics, while laparoscopic sleeve gastrectomy had a shorter surgical time and less blood loss.

An integration analysis based on genomic, transcriptomic and QTX information reveals credible candidate genes for fat-related traits in pigs

Meat quality improvement is of great interest to researchers in pig breeding and many researchers have identified abundant associated quantitative trait loci, genes and polymorphisms (QTXs) for fat-related traits. However, it is challenging to determine credible candidate genes from a mass of associations. The efficiency of identification of credible candidate genes in these QTXs is restricted by limited integration analyses of data from multiple omics. In this study, we constructed a 'candidate gene map' of fat-related traits in pigs based on published literature and the latest genome. In total, 6,861 QTXs, which covered 9,323 genes on the pig genome, were used. Combining the QTX hotspots and pathway analysis, we identified 180 candidate genes that may regulate the fat-related traits, and choose PNPLA2, PPARG, SREBF1, ACACA, PPARD and PPARA as credible candidate genes. In addition, we discussed the importance of incorporating transcriptome data and genomic data in causal gene identification, and the multi-omics information can effectively improve the credibility of identified candidate genes.

THU0408 EFFECT OF NEW-ONSET GOUT ON KIDNEY TRANSPLANT OUTCOMES: A RETROSPECTIVE COHORT ANALYSIS OF THE UNITED STATES RENAL DATA SYSTEM

Background:

Gout is a frequent comorbidity in kidney transplant (KT) recipients. However, assessing the independent effect of gout on KT outcomes is difficult because of multiple confounders (e.g., temporal changes in estimated glomerular filtration rate [eGFR], cyclosporine or tacrolimus dose, urate-lowering medication use) that obscure a clear picture of gout’s potential impact.

Objectives:

This investigation assessed if the development of new-onset gout after KT was an independent risk factor for loss of graft function, as assessed by the need for maintenance hemodialysis following KT.

Methods:

This retrospective cohort study analyzed data on patients in the United States Renal Data System (USRDS) who received a primary KT between 1/1/2008 and 12/31/2015. The date of transplantation was the ‘index’ date. Eligible patients were required to have ≥24 months of Medicare coverage and no prior history of gout, defined as ≥1 claim with a gout diagnosis code in the 24 months prior to the index date. All patients were also required to have ≥12 months of coverage post index. Patients who died, experienced graft failure, or returned to dialysis <12 months post index were excluded. Because the first year following transplant is associated with the highest frequency of rejections, we evaluated subjects beginning 1 year after transplant. The exposure of interest was new-onset gout, defined as the presence of ≥2 claims for gout post index, and the primary endpoint was return to dialysis >12 months post index. Baseline time-invariant confounders included recipient and donor demographics and clinical characteristics at index. Time-varying confounders included body mass index (BMI) adjusted tacrolimus and cyclosporine dose, eGFR, and urate-lowering medication use post index. Patients who died or lost Medicare coverage >12 months post index were censored; all patients remaining at the end of the study period (12/31/2016) were also censored. A marginal structural model (MSM) was fitted to determine the relative risk of new-onset gout on return to dialysis, while controlling for both time-invariant and time-varying confounders.

Results:

18,525 of 466,589 KT recipients in the USRDS met study eligibility. Within the observation period, 1,399 (7.6%) developed new-onset gout and 1,420 (7.7%) returned to dialysis >12 months post index. Median time from index to new-onset gout and from index to return to dialysis was 16.2 months (IQR: 33.4) and 32.8 months (IQR: 28.4), respectively. Adjusting for baseline time-invariant and time-varying confounders via the MSM showed new-onset gout was associated with a 51% increased risk of return to dialysis >12 months post index (RR: 1.51, 95% CI: 1.03, 2.20).

Conclusion:

New-onset gout was independently associated with a 51% increased risk of return to dialysis >12 months after primary KT compared to a control cohort without gout. To our knowledge, this is the first observation of this outcome in an appropriately controlled cohort study of KT recipients with gout. Results from this analysis may have important implications for the monitoring and management of new-onset gout in the kidney transplant population.

References:

[1]Mandell BF.Cleve Clin J Med2008;75(Suppl 5):S5-8.

[2]Forbess LJ, Fields TR.Sem Arthritis Rheum2012;42:146-54.

[3]Gibson T.Curr Opin Rheumatol2012;24:127-31.

[4]Zhang L, et al.Nephrol Dial Transplant2012;27:1836-9.

[5]Clive DM.J Am Soc Nephrol2000;11:974-9.

[6]Kalantar E, et al.Transplant Proc2011;43:584-5.

[7]Lin HY, et al.N Engl J Med1989;321:287-92.

[8]Ben Hmida M, et al.Transplant Proc1995;27:2722-4.

[9]Kanbay M, et al.Transplant Proc2005;37:3119-20.

[10]Baroletti S, Bencivenga GA.Prog Transplant2004;14:143-7.

[11]Kim ED, et al.Am J Transplant2015;15:482-8.

[12]Kim DG, et al.PloS One2018;13:e0209156.

Disclosure of Interests: :

Justin Li: None declared, David Yin: None declared, Zheng Wang: None declared, Mark Brigham: None declared, Brian LaMoreaux Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics, Jeffrey Kent Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics, Megan Francis-Sedlak Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics, Richard Johnson Shareholder of: Colorado Research Partners LLC, XORTX Therapeutics, Consultant of: Horizon Therapeutics, Eli Lilly, Speakers bureau: Horizon Therapeutics, Nandini Hadker: None declared, Kevin Francis: None declared, Herman Sanchez: None declared, Gavin Miyasato: None declared

Linking vein properties to leaf biomechanics across 58 woody species from a subtropical forest

Leaf venations have elements with relatively lower elasticity than other leaf tissue components, which are thought to contribute to leaf biomechanics. A better mechanistic understanding of relationships between vein traits and leaf mechanical properties is essential for ecologically relevant interpretation of leaf structural variations. We investigated 13 major (first to third order) and minor (>third order) vein traits, six leaf mechanical properties and other structural traits across 58 woody species from a subtropical forest to elucidate how vein traits contribute to leaf biomechanics. Across species, vein dry mass density (ρ_v ), total vein dry mass per leaf area (VMA) and minor vein diameter (VD_min ), but not the lower-order vein density (VLA_1•2 ), were positively correlated with leaf force to punch (F_p ) and force to tear (F_t ). Structural equation models showed that ρ_v and VD_min not only contribute to leaf mechanical properties directly (direct pathway), but also had impacts on leaf biomechanics by influencing leaf thickness and leaf dry mass per area (indirect pathway). Our study demonstrated that vein dry mass density and minor vein diameter are the key vein properties for leaf biomechanics. We also suggest that the mechanical characteristics of venations are potential factors influencing leaf mechanical resistance, structure and leaf economics spectrum.

Synthesis and crystal structure of tert-butyl 1-(2-iodobenzoyl)cyclopent-3-ene-1-carboxylate

The cyclo­pent-3-ene ring has an envelope conformation with the tertiary C atom as the flap atom.

1-(2-Iodo­benzo­yl)-cyclo­pent-3-ene-1-carboxyl­ates are novel substrates to construct bi­cyclo­[3.2.1]octa­nes with anti­bacterial and anti­thrombotic activities. In this context, tert-butyl 1-(2-iodo­benzo­yl)-cyclo­pent-3-ene-1-carboxyl­ate, C₁₇H₁₉IO₃, was synthesized and structurally characterized. The 2-iodo­benzoyl group is attached to the tertiary C atom of the cyclo­pent-3-ene ring. The dihedral angle between the benzene ring and the mean plane of the envelope-type cyclo­pent-3-ene ring is 26.0 (3)°. In the crystal, pairs of C-H⋯O hydrogen bonds link the mol­ecules to form inversion dimers.

Distribution of clinically relevant antibiotic resistance genes in Lake Tai, China

Lake Tai is China's third largest freshwater lake and an important water resource for agriculture, industrial sectors, and as drinking water for several large cities. In this study, the occurrence of five antibiotic resistance genes (sul1, bla_TEM, bla_NDM-1, bla_CTX-M-32, mcr-1) was investigated in water and sediment samples collected from Lake Tai. Antibiotic resistances are currently increasing, posing a significant threat to public health. The sulfonamide resistance gene sul1 was highly abundant in all analyzed water and sediment samples. In addition, the two β-lactamase genes bla_TEMand bla_NDM-1 - encoding clinically relevant antibiotic resistances - were detected in 67.1 and 7.3% of the water samples and in 70.7 and 15.4% of the sediment samples. The third β-lactamase gene, bla_CTX-M-32, was only detected in water samples (13.4%), while the colistin resistance gene mcr-1 was not detected in any of the samples. No significant variations between different sampling sites or time points could be observed. The investigation of drinking water treatment at Lake Tai, using lake water as influent, showed a significant reduction of the antibiotic resistance genes through the treatment process. Microbial source tracking showed only low fecal contamination by humans, ruminants, and pigs, indicating the relevance of other sources such as fish farms. Overall, our results provide important insights into the occurrence and abundance of antibiotic resistance genes in the Lake Tai water system and their elimination via drinking water treatment.

Clinical and molecular epidemiologic characteristics of carbapenem-resistant Klebsiella pneumoniae infection/colonization among neonates in China

BACKGROUND

The spread of carbapenem-resistant Klebsiella pneumoniae (CR-KPN) is a major concern, but data on CR-KPN infection/colonization in paediatric populations are limited.

AIM

To analyse epidemiologic and clinical characteristics, and therapeutic options for CR-KPN infections in neonates in China.

METHODS

A retrospective study was performed at the Children's Hospital of Fudan University, including 88 neonates with CR-KPN admitted between November 2015 and October 2016. Forty-seven CR-KPN isolates were chosen at random for further study, including antimicrobial susceptibility testing, potential β-lactamase screening and homology analysis.

FINDINGS

In total, 44.3% (39/88) of the neonates with CR-KPN were infected, and 71.8% (28/39) were nosocomial infections. Of these, pneumonia and urinary tract infection accounted for 50.0% (14/28) and 42.9% (12/28), respectively. All infected patients were cured or improved with fosfomycin and/or carbapenem-containing combination therapy, except one case in whom treatment was withdrawn. All 47 cases of CR-KPN were resistant to ertapenem and 95.7% were resistant to imipenem/meropenem. Overall, 87.2% (41/47) were positive for bla_NDM-1, and belonged to 11 pulsed-field gel electrophoresis types; 53.7% (22/41) were designated as ST278 and 17.1% (7/41) were designated as ST2735 by multi-locus sequence typing.

CONCLUSIONS

Most of the CR-KPN isolated from neonates produced New Delhi metallo-beta-lactamase-1 and were highly homologous. Fosfomycin-containing regimens and meropenem-/panipenem-containing combination therapy were efficient for CR-KPN infection in neonates.

Stronger selective constraint on downstream genes in the oxidative phosphorylation pathway of cetaceans

The oxidative phosphorylation (OXPHOS) pathway is an efficient way to produce energy via adenosine triphosphate (ATP), which is critical for sustaining an energy supply for cetaceans in a hypoxic environment. Several studies have shown that natural selection may shape the evolution of the genes involved in OXPHOS. However, how network architecture drives OXPHOS protein sequence evolution remains poorly explored. Here, we investigated the evolutionary patterns of genes in the OXPHOS pathway across six cetacean genomes within the framework of a functional network. Our results show a negative correlation between the strength of purifying selection and pathway position. This result indicates that downstream genes were subjected to stronger evolutionary constraints than upstream genes, which may be due to the dual function of ATP synthase in the OXPHOS pathway. Additionally, there was a positive correlation between codon usage bias and omega (ω = dN/dS) and a negative correlation with synonymous substitution rate (dS), indicating that the stronger selective constraint on genes (with less biased codon usage) along the OXPHOS pathway is attributable to an increase in the rate of synonymous substitution. Surprisingly, there was no significant correlation between protein-protein interactions and the evolutionary estimates, implying that highly connected enzymes may not always show greater evolutionary constraints. Compared with that observed for terrestrial mammals, we found that the signature of positive selection detected in five genes (ATP5J, LHPP, PPA1, UQCRC1 and UQCRQ) was cetacean-specific, reflecting the importance of OXPHOS for survival in hypoxic, aquatic environments.

CORRELATION BETWEEN CLINICAL PATHOLOGY OF LUMINAL B BREAST CANCER AND DETERMINATION OF ESTROGEN RECEPTOR, PROGESTERONE RECEPTOR AND HER2 EXPRESSION COMBINED WITH NUCLEAR MORPHOLOGY

Breast cancer, one of the most common malignant tumors in females, draws little attention because of its untypical symptoms and signs, so the disease is usually confirmed too late, in an advanced stage. Based on the detection of nuclear morphology parameters of luminal B breast cancer, this study explored how pathological features relate to estrogen receptor (ER) and progesterone receptor (PR) expression of human epidermal growth factor receptor-2 (HER2). A quantity of 354 breast cancer specimens with follow-up records from the department of pathology in the First People’s Hospital of Nantong and the Tumor Hospital of Nantong were selected as research subjects. Nuclear parameters of specimens stained by hematoxylin and eosin were measured by imaging analysis software. It was found that breast cancer can be divided into four types, luminal B, luminal A, HER2 over-expression and basal-like type based on immunohistochemical results of three antibodies, i.e, ER, PR and HER2. A total of 113 patients (31.8%) were confirmed with luminal B breast cancer, mostly in histological stage II; the difference of nuclear morphology was of statistical significance between ER+/PR+ and ER-/PR- (P<0.05), and most ER-/PR- was histologically confirmed as stage III, with lower survival rate than ER+/PR+ (P<0.05). Among these four subtypes of breast cancer, luminal B had the lowest brain metastasis rate, while HER2 over-expression subtype was found with the highest rate of lung and pleura metastasis. Besides, luminal B possessed longer disease-free survival (DFS) than basal-like (P<0.05) and longer total survival (OS) than HER2 over-expression (P<0.05) and basal-like subtypes (P<0.05). It can be concluded that detection of ER, PR and HER2 in combination with nuclear morphology is beneficial to evaluate treatment and prognosis of breast cancer.

All-atom empirical potential for molecular modeling and dynamics studies of proteins

New protein parameters are reported for the all-atom empirical energy function in the CHARMM program. The parameter evaluation was based on a self-consistent approach designed to achieve a balance between the internal (bonding) and interaction (nonbonding) terms of the force field and among the solvent-solvent, solvent-solute, and solute-solute interactions. Optimization of the internal parameters used experimental gas-phase geometries, vibrational spectra, and torsional energy surfaces supplemented with ab initio results. The peptide backbone bonding parameters were optimized with respect to data for N-methylacetamide and the alanine dipeptide. The interaction parameters, particularly the atomic charges, were determined by fitting ab initio interaction energies and geometries of complexes between water and model compounds that represented the backbone and the various side chains. In addition, dipole moments, experimental heats and free energies of vaporization, solvation and sublimation, molecular volumes, and crystal pressures and structures were used in the optimization. The resulting protein parameters were tested by applying them to noncyclic tripeptide crystals, cyclic peptide crystals, and the proteins crambin, bovine pancreatic trypsin inhibitor, and carbonmonoxy myoglobin in vacuo and in crystals. A detailed analysis of the relationship between the alanine dipeptide potential energy surface and calculated protein φ, χ angles was made and used in optimizing the peptide group torsional parameters. The results demonstrate that use of ab initio structural and energetic data by themselves are not sufficient to obtain an adequate backbone representation for peptides and proteins in solution and in crystals. Extensive comparisons between molecular dynamics simulations and experimental data for polypeptides and proteins were performed for both structural and dynamic properties. Energy minimization and dynamics simulations for crystals demonstrate that the latter are needed to obtain meaningful comparisons with experimental crystal structures. The presented parameters, in combination with the previously published CHARMM all-atom parameters for nucleic acids and lipids, provide a consistent set for condensed-phase simulations of a wide variety of molecules of biological interest.

miR-27a regulates endothelial differentiation of breast cancer stem like cells

Recent studies suggested that cancer stem cells (CSCs) are capable of differentiating into endothelial cells and tumor endothelium may be derived from CSCs. But the mechanism remains unclear. We showed that vascular endothelial growth factor (VEGF) induced the expression of endothelial markers in breast cancer stem like cells (BCSLCs). In addition, the VEGF-treated BCSLCs formed capillary structure in matrigel and released vWF upon histamine treatment. The miR-27a expression was significantly increased in VEGF-treated BCSLCs. Antagonizing miR-27a by miR-27a anti-sense oligos (ASOs) in VEGF-treated BCSLCs led to decreased endothelial markers and function, while increasing miR-27a in BCSLCs resulted in enhanced endothelial properties. VEGF enhanced the transcription of miR-27a by increasing RUNX1 binding to miR-27a promoter. Increased miR-27a paralleled the reduced expression of ZBTB10, a known miR-27a target. Both expression of miR-27a and knockdown of ZBTB10 in BCSLCs promoted in vivo angiogenesis and tumor metastasis. Further, we demonstrated that VEGF-treated BCSLCs secreted more endogenous VEGF compared with undifferentiated BCSLCs. Thus, miR-27a promotes angiogenesis by mediating endothelial differentiation of BCSLCs and it may be a new target for anti-angiogenesis cancer therapy.