Macrophage RAGE deficiency prevents myocardial fibrosis by repressing autophagy-mediated macrophage alternative activation.

Myocardial fibrosis (MF) is the characteristic pathological feature of various cardiovascular diseases that lead to heart failure (HF) or even fatal outcomes. Alternatively, activated macrophages are involved in the development of fibrosis and tissue remodeling. Although the receptor for advanced glycation end products (RAGE) is involved in MF, its potential role in regulating macrophage function in cardiac fibrosis has not been fully investigated. We aimed to determine the role of macrophage RAGE in transverse aortic constriction (TAC)-induced MF. In this study, we found that RAGE expression was markedly increased in the infiltrated alternatively activated macrophages within mice hearts after TAC. RAGE knockout mice showed less infiltration of alternatively activated macrophages and attenuated cardiac hypertrophy and fibrosis compared to the wild-type mice. Our data suggest that mice with macrophage-specific genetic deletion of RAGE were protected from interstitial fibrosis and cardiac dysfunction when subjected to pressure overload, which led to a decreased proportion of alternatively activated macrophages in heart tissues. Our in vitro experiments demonstrated that RAGE deficiency inhibited the differentiation into alternatively activated macrophages by suppressing autophagy activation. In the co-culture system, in vitro polarization of RAW264.7 macrophages toward an alternatively activated phenotype stimulated the expression of α-smooth muscle actin and collagen in cardiac fibroblasts. However, the knockdown of RAGE and inhibition of autophagy in macrophages showed reduced fibroblast-to-myofibroblast transition (FMT). Collectively, our results suggest that RAGE plays an important role in the recruitment and activation of alternatively activated macrophages by regulating autophagy, which contributes to MF. Thus, blockage of RAGE signaling may be an attractive therapeutic target for the treatment of hypertensive heart disease.

Ten-year trends in surgical management of 1207 congenital scoliosis.

PURPOSE: To report and analyze development trends in the surgical treatment of congenital scoliosis (CS) in a large CS cohort over a 10-year period. METHODS: We retrospectively searched and extracted medical records of CS inpatients receiving posterior instrumented fusion surgery at our institute from January 2010 to December 2019. We analyzed information on demographics and surgical information, including the surgical approach, number of fused segments, use of osteotomy and titanium cage implantation, length of stay, intraoperative blood loss, and rates of complications and readmission. RESULTS: 1207 CS inpatients were included. In the past decade, the proportion of patients younger than 5 years increased from 15.5 to 26.9%. The average number of fused segments decreased from 9.24 to 7.48, and the proportion of patients treated with short-segment fusion increased from 13.4 to 30.3%. The proportion of patients treated with osteotomy and titanium cage implantation increased from 55.65% and 12.03% to 76.5% and 40.22%. The average length of stay and blood loss decreased from 16.5 days and 816.1 ml to 13.5 days and 501.7 ml. The complication and readmission rates also decreased during these ten years. CONCLUSION: During this ten-year period, the surgical treatment of CS at our institute showed trends toward a younger age at fusion, lower number of fused segments, higher rate of osteotomy and titanium cage implantation, reduced blood loss, shorter length of stay and lower rate complications and readmission. These results suggest performing osteotomy combined with titanium cage implantation at an earlier age can achieve fewer fused segments and complications.

Plantamajoside attenuates cardiac fibrosis via inhibiting AGEs activated-RAGE/autophagy/EndMT pathway.

Advanced glycation end products (AGEs) have been identified to transduce fibrogenic signals via inducing the activation of their receptor (RAGE)-mediated pathway. Recently, disrupting AGE-RAGE interaction has become a promising therapeutic strategy for chronic heart failure (CHF). Endothelial-to-mesenchymal transition (EndMT) is close to the cardiac fibrosis pathological process. Our previous studies have demonstrated that knockout RAGE suppressed the autophagy-mediated EndMT, and thus alleviated cardiac fibrosis. Plantamajoside (PMS) is the major bioactive compound of Plantago Asiatica, and its activity of anti-fibrosis has been documented in many reports. However, its effect on CHF and the underlying mechanism remains elusive. Thus, we tried to elucidate the protective role of PMS in CHF from the viewpoint of the AGEs/RAGE/autophagy/EndMT axis. Herein, PMS was found to attenuate cardiac fibrosis and dysfunction, suppress EndMT, reduce autophagy levels and serum levels of AGEs, yet did not affect the expression of RAGE in CHF mice. Mechanically, PMS possibly binds to the V-domain of RAGE, which is similar to the interaction between AGEs and RAGE. Importantly, this competitive binding disturbed AGEs-induced the RAGE-autophagy-EndMT pathway in vitro. Collectively, our results indicated that PMS might exert an anti-cardiac fibrosis effect by specifically binding RAGE to suppress the AGEs-activated RAGE/autophagy/EndMT pathway.

Gold-Catalyzed Amine Cascade Addition to Diyne-Ene: Enantioselective Synthesis of 1,2-Dihydropyridines.

With the well-documented chemical and biological applications, piperidine and pyridine are among the most important N-heterocycles, and a new synthetic strategy, especially one with an alternative bond-forming design, is of general interest. Using the gold-catalyzed intermolecular condensation of amine and diyne-ene, we report herein the first example of enantioselective 1,2-dihydropyridine synthesis through a formal [3+2+1] fashion (up to 95 % yield, up to 99 % e.e.).

Asymmetric Hydrative Aldol Reaction (HAR) via Vinyl-Gold Promoted Intermolecular Ynamide Addition to Aldehydes.

Herein, we reported an intermolecular asymmetric hydrative aldol reaction through vinyl-gold intermediate under ambient conditions. This tandem alkyne hydration and sequential nucleophilic addition afforded a "base-free" approach to ß-hydroxy amides with high efficiency (up to 95 % yields, >50 examples). Vinyl gold intermediate was applied as reactive nucleophile and Fe(acac)3 was used as the critical co-catalyst to prevent undesired protodeauration, allowing this transformation to proceed under mild conditions with good functional group tolerance and excellent stereoselectivity (>20 : 1 d.r. and up to 99 % ee).

Chiral Hemilabile P,N-Ligand-Assisted Gold Redox Catalysis for Enantioselective Alkene Aminoarylation.

Enantioselective, intermolecular alkene arylamination was achieved through gold redox catalysis. Screening of ligands revealed chiral P,N ligands as the optimal choice, giving alkene aminoarylation with good yields (up to 80 %) and excellent stereoselectivity (up to 99 : 1 er). As the first example of enantioselective gold redox catalysis, this work confirmed the feasibility of applying a chiral ligand at the gold(I) stage, with the stereodetermining step (SDS) at the gold(III) intermediate, thus opening up a new way to conduct gold redox catalysis with stereochemistry control.

Au-24 as a potential thioredoxin reductase inhibitor in hepatocellular carcinoma cells.

A novel TrxR inhibitor Au-24 and its inhibitory ability to hepatocellular carcinoma in vitro and in vivo is reported herein. Au-24 can suppress HepG2 cells from proliferating by lowering mitochondrial membrane potential (MMP) and increasing reactive oxygen species (ROS) levels, resulting in oxidative stress, which causes DNA damage, autophagy, cell cycle arrest, and apoptosis. This compound can also affect the normal function of apoptosis, MAPK, PI3K/AKT/mTOR, NF-κB, STAT3 signaling pathways. In vivo experiments revealed that Au-24 inhibited HepG2 tumor growth more effectively than AA1 (chloro(triethylphosphine)gold(I)) by decreasing Ki67 and CD31 protein expression and promoting tumor cell apoptosis and necrosis lesions. As a result, Au-24 was found to be a promising candidate as a TrxR inhibitor for the treatment of hepatocellular carcinoma (HCC) in both in vivo and in vitro experiments.

Alkyne Trifunctionalization via Divergent Gold Catalysis: Combining π-Acid Activation, Vinyl-Gold Addition, and Redox Catalysis.

Here we report the first example of alkyne trifunctionalization through simultaneous construction of C-C, C-O, and C-N bonds via gold catalysis. With the assistance of a γ-keto directing group, sequential gold-catalyzed alkyne hydration, vinyl-gold nucleophilic addition, and gold(III) reductive elimination were achieved in one pot. Diazonium salts were identified as both electrophiles (N source) and oxidants (C source). Vinyl-gold(III) intermediates were revealed as effective nucleophiles toward diazonium, facilitating nucleophilic addition and reductive elimination with high efficiency. The rather comprehensive reaction sequence was achieved with excellent yields (up to 95%) and broad scope (>50 examples) under mild conditions (room temperature or 40 °C).

Cross-sectional analysis of associated anomalies and vertebral anomaly location in 1289 surgical congenital scoliosis.

PURPOSE: This study systematically analyzed and assessed the interrelationships among vertebral anomaly location, congenital scoliosis (CS) type and associated abnormality prevalence. METHODS: We retrospectively extracted medical records of 1289 CS inpatients surgically treated in our institute from January 2010-December 2019. All patients underwent spinal X-ray, CT, MRI, echocardiogram, urogenital ultrasound and systemic physical examination. We analyzed information on demographics, CS type, associated anomalies and vertebral anomaly location. RESULTS: Cervical, thoracic and lumbar vertebral anomalies were found in 5.7%, 78.1% and 33.6% of patients, respectively. 82.7% had one region involved. 59.5% with cervical malformations had mixed defects and 61.1% with lumbar malformations exhibited failure of formation. The musculoskeletal defect prevalence was 28.4%, 19.1% and 9.0% in patients with cervical, thoracic and lumbar anomalies. The intraspinal defect prevalence was 33.4% and 20.7% for thoracic and lumbar anomalies. 86.5% of patients with cervical anomalies had more than one region involved, while 78.1% and 62.2% with thoracic and lumbar anomalies, respectively, had only one region involved. CONCLUSIONS: Cervical malformations had higher prevalence of mixed defects, musculoskeletal and intraspinal defects and multi-region involved. Thoracic malformations had higher prevalence of intraspinal and musculoskeletal defects and more involvement of only one vertebral region. Lumbar vertebral malformation patients had much lower prevalence of intraspinal and musculoskeletal defects and more involvement of only one vertebral region. Cervical malformation was a risk factor for more associated anomalies and more severe vertebral anomalies, which deserves more attention from surgeons in outpatient clinic.

Older fusion-surgery age in congenital scoliosis patients is a risk factor for extended length of stay, more estimated blood loss, longer fused segments and higher medical costs: a retrospective study.

BACKGROUND: Contradictory opinions about whether early correction and fusion surgeries should be performed for congenital scoliosis (CS) patients at a young age exist. The objectives of this study were to analyze the association between patient characteristics and fusion-surgery outcomes in CS patients treated with spinal correction and fusion surgeries and to report risk factors for extended length of stay (LOS), more estimated blood loss (EBL), longer fused segments and higher medical costs. METHODS: We analyzed data of 1,207 CS inpatients treated with fusion surgeries in our institute from January 2010 - December 2019. All patients underwent spinal X-ray, CT, MRI, echocardiogram and urogenital ultrasound. We analyzed demographic and clinical information and outcome measures, including LOS, EBL, fused segments and medical costs. RESULTS: Age at fusion (OR = 1.053; p < 0.001), musculoskeletal defects (OR = 1.670; p = 0.004) and thoracic deformity (OR = 1.519; p = 0.03) were risk factors for extended LOS. Age at fusion (OR = 1.117; p < 0.001), male sex (OR = 1.813; p < 0.001), mixed defects (OR = 1.662; p = 0.027) and failure of formation (OR = 1.718; p = 0.021) were risk factors for more EBL. Age at fusion (OR = 1.213; p < 0.001) was a risk factor for longer fused segments. Age at fusion (OR = 1.091; p < 0.001) and thoracic deformity (OR = 1.853; p = 0.004) were risk factors for higher medical costs. CONCLUSIONS: We found that older age at fusion in CS patients is a risk factor for extended LOS, more EBL, longer fused segments and higher medical costs with the risk increasing by 5-21 % for each year of age. Other identified risk factors include thoracic deformity for extended LOS; longer fused segments, higher medical costs, and musculoskeletal defects for extended LOS; and CS type (FF and MD) and sex (male) for more EBL.

Metabolic engineering of Escherichia coli for L-malate production anaerobically.

BACKGROUND: L-malate is one of the most important platform chemicals widely used in food, metal cleaning, textile finishing, pharmaceuticals, and synthesis of various fine chemicals. Recently, the development of biotechnological routes to produce L-malate from renewable resources has attracted significant attention. RESULTS: A potential L-malate producing strain E. coli BA040 was obtained by inactivating the genes of fumB, frdABCD, ldhA and pflB. After co-overexpression of mdh and pck, BA063 achieved 18 g/L glucose consumption, leading to an increase in L-malate titer and yield of 13.14 g/L and 0.73 g/g, respectively. Meantime, NADH/NAD+ ratio decreased to 0.72 with the total NAD(H) of 38.85 µmol/g DCW, and ATP concentration reached 715.79 nmol/g DCW. During fermentation in 5L fermentor with BA063, 41.50 g/L glucose was consumed within 67 h with the final L-malate concentration and yield of 28.50 g/L, 0.69 g/g when heterologous CO2 source was supplied. CONCLUSIONS: The availability of NAD(H) was correlated positively with the glucose utilization rate and cellular metabolism capacities, and lower NADH/NAD+ ratio was beneficial for the accumulation of L-malate under anaerobic conditions. Enhanced ATP level could significantly enlarge the intracellular NAD(H) pool under anaerobic condition. Moreover, there might be an inflection point, that is, the increase of NAD(H) pool before the inflection point is followed by the improvement of metabolic performance, while the increase of NAD(H) pool after the inflection point has no significant impacts and NADH/NAD+ ratio would dominate the metabolic flux. This study is a typical case of anaerobic organic acid fermentation, and demonstrated that ATP level, NAD(H) pool and NADH/NAD+ ratio are three important regulatory parameters during the anaerobic production of L-malate.

Intermolecular Alkene Difunctionalization via Gold-Catalyzed Oxyarylation.

The gold-catalyzed intermolecular oxyarylation of alkenes is reported. This work employed the oxidative addition of aryl iodides to Me-DalphosAu+ for the formation of a AuIII -Ar intermediate. The better binding ability of alkenes over O nucleophiles ensured the success of intermolecular oxyarylation, giving desired products with a broad substrate scope and high efficiency (>50 examples with up to 95 % yield). One-pot converting of methoxy groups into other nucleophiles allowed achieving alkene difunctionalization with the construction of C-N, C-S, and C-C bonds under mild conditions.

Synergistic palladium/enamine catalysis for asymmetric hydrocarbon functionalization of unactivated alkenes with ketones.

Synergistic palladium and enamine catalysis was explored to promote ketone addition to unactivated olefins. A secondary amine-based organocatalyst was identified as the optimal co-catalyst for the directed Pd-catalyzed alkene activation. Furthermore, asymmetric hydrocarbon functionalization of unactivated alkenes was also achieved with good to excellent yield (up to 96% yields) and stereoselectivity (up to 96% ee). This strategy presented an efficient approach to prepare α-branched ketone derivatives under mild conditions.

Facilitating Gold Redox Catalysis with Electrochemistry: An Efficient Chemical-Oxidant-Free Approach.

Due to the high oxidation potential between AuI and AuIII , gold redox catalysis requires at least stoichiometric amounts of a strong oxidant. We herein report the first example of an electrochemical approach in promoting gold-catalyzed oxidative coupling of terminal alkynes. Oxidation of AuI to AuIII was successfully achieved through anode oxidation, which enabled facile access to either symmetrical or unsymmetrical conjugated diynes through homo-coupling or cross-coupling. This report extends the reaction scope of this transformation to substrates that are not compatible with strong chemical oxidants and potentiates the versatility of gold redox chemistry through the utilization of electrochemical oxidative conditions.

Direct Evidence for the Origin of Bis-Gold Intermediates: Probing Gold Catalysis with Mass Spectrometry.

Gold-catalyzed alkyne hydration was studied by using in situ reacting mass spectrometry (MS) technology. By monitoring the reaction process in solution under different conditions (regular and very diluted catalyst concentrations, different pH values) and examining the reaction occurrence in the early reaction stage (1-2 ms after mixing) with MS, we collected a series of experimental evidence to support that the bis-gold complex is a potential key reaction intermediate. Furthermore, both experimental and computational studies confirmed that the σ,π-bis-gold complexes are not active intermediates toward nucleophilic addition. Instead, formation of geminally diaurated complex C is crucial for this catalytic process.

TET1-Mediated Oxidation of 5-Formylcytosine (5fC) to 5-Carboxycytosine (5caC) in RNA.

It was recently revealed that 5-methylcytosine (5mC) in mRNA, similar to its behavior in DNA, can be oxidized to produce 5-hydroxymethylcytosine (5hmC) and 5-formylcytosine (5fC), implying the potential regulatory roles of this post-transcriptional RNA modification. In this study, we demonstrate the in vitro oxidation of 5fC to 5-carboxycytidine (5caC) by the catalytic domain of mammalian ten-eleven translocation enzyme (TET1) in different RNA contexts. We observed that this oxidation process has very low sequence dependence and can take place in single-stranded, double-stranded, or hairpin forms of RNA sequences, although the overall conversion yields are low.

Investigations on Gold-Catalyzed Thioalkyne Activation Toward Facile Synthesis of Ketene Dithioacetals.

Nucleophilic addition to thioalkynes was investigated under various catalytic conditions with gold(I) complexes being identified as the optimal catalysts. Structural evaluation of the product revealed an unexpected cis-addition, arising from a gold-associated thioketene intermediate. Based on this interesting mechanistic insight, a gold(I)-catalyzed thioether addition to thioalkynes was developed as a novel approach to prepare ketene dithioacetals with good yields and high efficiency.

Synthesis and characterization of bis-N-2-aryl triazole as a fluorophore.

Naphthalene-bridged bis-triazole (NBT) complexes were prepared and characterized for investigation of their photophysical properties. Unlike our previously reported N-2-aryl triazoles, which gave strong emissions through the planar intramolecular charge transfer mechanism (coplanar conformation), this newly developed NBT adopted a noncoplanar conformation between triazole and naphthalene, achieving fluorescence through twisted intramolecular charge transfer.

Facile synthesis and stereo-resolution of chiral 1,2,3-triazoles.

We describe herein the first facile synthesis of chiral triazoles through side chain functionalization. Readily available C-vinyl triazoles were used as starting materials, followed by sequential epoxidation, rearrangement and reduction to give the corresponding hydroxyl-triazoles. The CalB lipase catalyzed kinetic resolution gave enantiomerically pure (>99% ee) chiral triazoles in excellent yield. These new chiral TAs were also successfully applied as ligands in asymmetric addition of diethylzinc to aldehydes.