Aggregation-induced enhanced fluorescence emission of chiral Zn(II) complexes coordinated by Schiff-base type binaphthyl ligands

A pair of novel chiral Zn(II) complexes coordinated by Schiff-base type ligands derived from BINOL (1,1'-bi-2-naphthol), R-/S-Zn, were synthesized. X-ray crystallography revealed the presence of two crystallographically independent complexes; one has a distorted trigonal-bipyramidal structure coordinated by two binaphthyl ligands and one disordered methanol molecule (molecule A), while the other has a distorted tetrahedral structure coordinated by two binaphthyl ligands (molecule B). Numerous CH⋯π and CH⋯O interactions were identified, contributing to the formation of a 3-dimensional rigid network structure. Both R-/S-Zn exhibited fluorescence in both CH2Cl2 solutions and powder samples, with the photoluminescence quantum yields (PLQYs) of powder samples being twice as large as those in solutions, indicating aggregation-induced enhanced emission (AIEE). The AIEE properties were attributed to the restraint of the molecular motion arising from the 3-dimensional intermolecular interactions. CD and CPL spectra were observed for R-/S-Zn in both solutions and powders. The dissymmetry factors, gabs and gCPL values, were within the order of 10-3 to 10-4 magnitudes, comparable to those reported for chiral Zn(II) complexes in previous studies.

Pericardial effusion in oncological patients: current knowledge and principles of management

BACKGROUND

This article provides an up-to-date overview of pericardial effusion in oncological practice and a guidance on its management. Furthermore, it addresses the question of when malignancy should be suspected in case of newly diagnosed pericardial effusion.

MAIN BODY

Cancer-related pericardial effusion is commonly the result of localization of lung and breast cancer, melanoma, or lymphoma to the pericardium via direct invasion, lymphatic dissemination, or hematogenous spread. Several cancer therapies may also cause pericardial effusion, most often during or shortly after administration. Pericardial effusion following radiation therapy may instead develop after years. Other diseases, such as infections, and, rarely, primary tumors of the pericardium complete the spectrum of the possible etiologies of pericardial effusion in oncological patients. The diagnosis of cancer-related pericardial effusion is usually incidental, but cancer accounts for approximately one third of all cardiac tamponades. Drainage, which is mainly attained by pericardiocentesis, is needed when cancer or cancer treatment-related pericardial effusion leads to hemodynamic impairment. Placement of a pericardial catheter for 2-5 days is advised after pericardial fluid removal. In contrast, even a large pericardial effusion should be conservatively managed when the patient is stable, although the best frequency and timing of monitoring by echocardiography in this context are yet to be established. Pericardial effusion secondary to immune checkpoint inhibitors typically responds to corticosteroid therapy. Pericardiocentesis may also be considered to confirm the presence of neoplastic cells in the pericardial fluid, but the yield of cytological examination is low. In case of newly found pericardial effusion in individuals without active cancer and/or recent cancer treatment, a history of malignancy, unremitting or recurrent course, large effusion or presentation with cardiac tamponade, incomplete response to empirical therapy with nonsteroidal anti-inflammatory, and hemorrhagic fluid at pericardiocentesis suggest a neoplastic etiology.

FGF9, a Potent Mitogen, Is a New Ligand for Integrin αvβ3, and the FGF9 Mutant Defective in Integrin Binding Acts as an Antagonist

FGF9 is a potent mitogen and survival factor, but FGF9 protein levels are generally low and restricted to a few adult organs. Aberrant expression of FGF9 usually results in cancer. However, the mechanism of FGF9 action has not been fully established. Previous studies showed that FGF1 and FGF2 directly bind to integrin αvβ3, and this interaction is critical for signaling functions (FGF-integrin crosstalk). FGF1 and FGF2 mutants defective in integrin binding were defective in signaling, whereas the mutants still bound to FGFR suppressed angiogenesis and tumor growth, indicating that they act as antagonists. We hypothesize that FGF9 requires direct integrin binding for signaling. Here, we show that docking simulation of the interaction between FGF9 and αvβ3 predicted that FGF9 binds to the classical ligand-binding site of αvβ3. We show that FGF9 bound to integrin αvβ3 and generated FGF9 mutants in the predicted integrin-binding interface. An FGF9 mutant (R108E) was defective in integrin binding, activating FRS2α and ERK1/2, inducing DNA synthesis, cancer cell migration, and invasion in vitro. R108E suppressed DNA synthesis and activation of FRS2α and ERK1/2 induced by WT FGF9 (dominant-negative effect). These findings indicate that FGF9 requires direct integrin binding for signaling and that R108E has potential as an antagonist to FGF9 signaling.

FGF9, a potent mitogen, is a new ligand for integrin αvβ3, and the FGF9 mutant defective in integrin binding acts as an antagonist

FGF9 is a potent mitogen and survival factor, but FGF9 protein level is generally low and restricted to a few adult organs. Aberrant expression of FGF9 usually results in cancer. However, the mechanism of FGF9 action has not been fully established. Previous studies showed that FGF1 and FGF2 directly bind to integrin αvβ3 and this interaction is critical for signaling functions (FGF-integrin crosstalk). FGF1 and FGF2 mutants defective in integrin binding were defective in signaling, whereas the mutants still bound to FGFR, and suppressed angiogenesis and tumor growth, indicating that they act as antagonists. We hypothesize that FGF9 requires direct integrin binding for signaling. Here we show that docking simulation of interaction between FGF9 and αvβ3 predicted that FGF9 binds to the classical ligand-binding site of αvβ3. We showed that FGF9 actually bound to integrin αvβ3, and generated an FGF9 mutants in the predicted integrin-binding interface. An FGF9 mutant (R108E) was defective in integrin binding, activating FRS2α and ERK1/2, inducing DNA synthesis, cancer cell migration, and invasion in vitro. R108E suppressed DNA synthesis induced by WT FGF9 and suppressed DNA synthesis and activation of FRS2α and ERK1/2 induced by WT FGF9 (dominant-negative effect). These findings indicate that FGF9 requires direct integrin binding for signaling and that R108E has potential as an antagonist to FGF9 signaling.

Theoretical Investigations of Palladium-Catalyzed [3+2] Annulation via Benzylic and meta C-H Bond Activation

The palladium-catalyzed reaction of aromatic amides with maleimides results in the formation of a double C-H bond activation product, which occurs at both the benzylic and meta positions. Computational chemistry studies suggest that the first C-H bond activation unfolds via a six-membered palladacycle, maleimide insertion, protonation of the Pd-N bond, and then activation of the meta C-H bond. The process concludes with reductive elimination, producing an annulation product. The energy decomposition analysis (EDA) showed that the deformation energy favors the ortho C-H bond activation process. However, this route is non-productive. The interaction energy controls the site where the maleimide is inserted into the Pd-C(sp3 ) bond, which determines its site selectivity. The energetic span model indicates that the meta C-H bond activation step is the one that determines the turnover frequency. Regarding the directing group, it has been concluded that the strong Pd-S bonding and the destabilizing effect of the deformation energy allow the 2-thiomethylphenyl to function effectively as a directing group.

Systematic elucidation of the second coordination sphere effect on the structure and properties of a blue copper protein, pseudoazurin

The rational structural and computational studies of a blue copper protein, pseudoazurin (PAz), and its Met16X (X = Phe, Leu, Val, Ile) variants gave clear functional meanings of the noncovalent interaction (NCI) through the second coordination sphere. The high-resolution X-ray crystal structures of Met16X PAz demonstrated that the active site geometry is significantly affected by the substitution of Met16, which is located within the NCI distance from the His81 imidazole ring at the copper active site. The computational chemistry calculations based on the crystal structure analyses confirmed that the NCI of S-π/CH-π (wild-type), π-π (Met16Phe), double CH-π (Met16Leu), and single CH-π (Met16Val and Met16Ile). The estimated interaction energies for the NCI demonstrated that the fine-tuning of the protein stability and Cu site properties form the second coordination sphere of PAz.

Incorporation of a bromine atom into DNA-related molecules changes their electronic properties

To understand the mechanism underlying the high radio-sensitisation of living cells possessing brominated genomic DNA, X-ray photoelectron spectroscopy (XPS) using synchrotron X-rays with energies of 2000 or 2500 eV was used to study brominated and nonbrominated nucleobases, nucleosides and nucleotides. The bromine atom significantly reduced the energy gap between the valence and conduction states, although the core level states were not greatly affected. This finding was supported by quantum chemical calculation for the nucleobases and nucleosides. Our findings strongly indicate that the energy gaps between the valence and conduction levels of the molecules are significantly reduced by bromination. Furthermore, the brominated molecules are more likely to produce inelastic scattering low energy electrons upon exposure to 2000 or 3000 eV X-rays. This modification of electronic properties around the brominated group may both facilitate electron transfer to the brominated site in DNA and increase the probability of reaction with low energy electrons. These processes can induce DNA damage, presumably resulting in debromination of the uracil moiety and a subsequent cytotoxic effect.

KRT13 is upregulated in pancreatic cancer stem-like cells and associated with radioresistance

Pancreatic cancer is one of the most aggressive cancers and the seventh leading cause of cancer-associated death in the world. Radiation is performed as an adjuvant therapy as well as anti-cancer drugs. Because cancer stem-like cells (CSCs) are considered to be radioresistant and cause recurrence and metastasis, understanding their properties is required for the development of novel therapeutic strategies. To investigate the CSC properties of pancreatic cancer cells, we used a pancreatic CSC model, degron (++) cells, which have low proteasome activity. Degron (++) cells displayed radioresistance in comparison with control cells. Using Ribonucleic acid (RNA) sequencing, we successfully identified KRT13 as a candidate gene responsible for radioresistance. Knockdown of KRT13 sensitized the degron (++) cells to radiation. Furthermore, a database search revealed that KRT13 is upregulated in pancreatic cancer cell lines and that high expression of KRT13 is associated with poorer prognosis. These results indicate that a combination therapy of KRT13 knockdown and radiation could hold therapeutic promise in pancreatic cancer.

Experimental and theoretical studies of the rhodium(I)-catalysed C-H oxidative alkenylation/cyclization of N-(2-(methylthio)phenyl)benzamides with maleimides

The rhodium(I)-catalysed reaction of aromatic amides that contain a 2-(methylthio)aniline directing group with maleimides gives isoindolone spirosuccinimides as products under aerobic, metal oxidant-free, and solvent-free conditions. In sharp contrast to...

Neutron crystallography and quantum chemical analysis of bilin reductase PcyA mutants reveal substrate and catalytic residue protonation states

PcyA, a ferredoxin-dependent bilin pigment reductase, catalyzes the site-specific reduction of the two vinyl groups of biliverdin (BV), producing phycocyanobilin. Previous neutron crystallography detected both the neutral BV and its protonated form (BVH⁺) in the wildtype (WT) PcyA-BV complex, and a nearby catalytic residue Asp105 was found to have two conformations (protonated and deprotonated). Semiempirical calculations have suggested that the protonation states of BV are reflected in the absorption spectrum of the WT PcyA-BV complex. In the previously determined absorption spectra of the PcyA D105N and I86D mutants, complexed with BV, a peak at 730 nm, observed in the WT, disappeared and increased, respectively. Here, we performed neutron crystallography and quantum chemical analysis of the D105N-BV and I86D-BV complexes to determine the protonation states of BV and the surrounding residues and study the correlation between the absorption spectra and protonation states around BV. Neutron structures elucidated that BV in the D105N mutant is in a neutral state, whereas that in the I86D mutant is dominantly in a protonated state. Glu76 and His88 showed different hydrogen bonding with surrounding residues compared with WT PcyA, further explaining why D105N and I86D have much lower activities for phycocyanobilin synthesis than the WT PcyA. Our quantum mechanics/molecular mechanics calculations of the absorption spectra showed that the spectral change in D105N arises from Glu76 deprotonation, consistent with the neutron structure. Collectively, our findings reveal more mechanistic details of bilin pigment biosynthesis.

POS0670 EVALUATION OF UPADACITINIB IN RHEUMATOID ARTHRITIS PATIENTS WITH INADEQUATE RESPONSE TO FIRST-GENERATION JANUS KINASE INHIBITORS

Background

Janus kinase inhibitors (JAKi) are effective in the treatment of patients with difficult-to-treat rheumatoid arthritis (D2T RA), regardless of previous use of biological disease-modifying antirheumatic drugs (bDMARDs), and receive equal billing with biological therapies in the latest version of the EULAR recommendations for treatment of RA1. However, as with bDMARDs, cases of discontinuation due to intolerance or inadequate response have been observed in patients treated with the so-called first-generation JAKi, leading to the development of a new generation of JAKi that aims to maximize efficacy and improve safety by enhancing kinase selectivity. The results of randomized controlled trials and meta-analyses suggest that the efficacy and safety of Upadacitinib (UPA) treatment are favorable. Although there have been no head-to-head trials between JAKi, a matched-adjusted indirect comparative study has shown a difference in efficacy between JAKi2, suggesting that the new generation of JAKi may be effective in rheumatoid arthritis patients with intolerance or inadequate response to first-generation JAKi. It is already apparent that a clear need exists for a JAK-IR trial to give guidance in those difficult patients who are JAKi non-responders3.

Objectives

To evaluate real world efficacy of a second-generation JAK1-selective JAKi UPA in single-center cohort of RA patients who had discontinued first-generation JAKi.

Methods

Patients with RA who had discontinued tofacitinib and/or baricitinib due to inadequate response or intolerance, regardless of whether they had used bDMARDs or not, were eligible for the study if they had received UPA by October 2021 and had been followed up for at least 12 weeks. Endpoints were Kaplan-Meier survival rate with inadequate response or intolerance as reasons for discontinuation, various disease activity assessments (DAS28-ESR, SDAI, CDAI, etc.), and patient reported outcomes (visual analogue scales (VASs) such as pain and stiffness, HAQ-DI, FACIT-Fatigue Scale, etc.) at 12 weeks. In addition, the reasons for discontinuation were investigated.

Results

Fifty-one patients were included in the study, all of whom had D2T RA and had used at least one bDMARD as well as JAKi. The mean (median) age was 72.7 (77) years, disease duration 18.0 (17) years, number of bDMARDs used 3.34 (3), number of JAKi used 1.3(1), 5 patients with methotrexate, 6 patients with prednisolone, and DAS28-ESR 3.83 (3.9). At 12 weeks, the overall survival rate was 94% (94.6% in 37 cases used as 2nd JAKi and 92.9% in 14 cases used as 3rd JAKi). For reference, there was no significant difference from the 100% of the 15 cases used as the 1st JAKi (P=0.49). DAS28-ESR <3.2 and <2.6 were achieved in 60.8% and 29.4%, VASs for pain and stiffness decreased by a mean of 12.9 mm (9 mm) and 12.1 mm (7 mm), respectively, and FACIT-Fatigue scale improved by a mean of 3.0 (1). The reasons for discontinuation in the three patients were inadequate efficacy in two and leg cramps due to venous thromboembolism in one.

Conclusion

UPA is more selective for JAK1 than first generation JAKi, and is expected to reduce adverse reactions caused by inhibition of JAK family members other than JAK1. The present study suggests that UPA is effective and well tolerated, regardless of the number and type of first-generation JAKi used in the past, albeit for a short period of time. Limitations include the small number of cases and the short time frame for discussing adverse reactions.

References

[1]Smolen JS, Landewé BM, Bijlsma WJ et al., EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Ann Rheum Dis 2020;79:685–699.

[2]Christopher JE, Ruta S, Vishvas G et al. A Matching-Adjusted Indirect Comparison of Upadacitinib Versus Tofacitinib in Adults with Moderate-to-Severe Rheumatoid Arthritis. Rheumatol Ther 2021; 8:167–181.

[3]Peter Nash, Clinical use of Jak 1 inhibitors for rheumatoid arthritis. Rheumatology, Volume 60, Issue Supplement_2, May 2021, Pages ii31–ii38

Disclosure of Interests

None declared

Non-innocent redox behavior of CuII-p-dimethylaminophenolate complexes: formation and characterization of the CuI-phenoxyl radical species

Cu complexes with p-dimethylaminophenolate ligands were synthesized by the reaction of Cu^II ions with the ligands under inert gas atmosphere and characterized. The complexes showed a valence state change from Cu^II-phenolate to Cu^I-phenoxyl radical on loss of the coordinated solvent. The Cu^I-phenoxyl radical species showed the characteristic properties and reactivities.

Iridium(III)-Catalyzed Asymmetric Site-Selective Carbene C-H Insertion during Late-Stage Transformation

C-H functionalization has recently received considerable attention because C-H functionalization during the late-stage transformation is a strong and useful tool for the modification of the bioactive compounds and the creation of new active molecules. Although a carbene transfer reaction can directly convert a C-H bond to the desired C-C bond in a stereoselective manner, its application in late-stage material transformation is limited. Here, we observed that the iridium-salen complex 6 exhibited efficient catalysis in asymmetric carbene C-H insertion reactions. Under optimized conditions, benzylic, allylic, and propargylic C-H bonds were converted to desired C-C bonds in an excellent stereoselective manner. Excellent regioselectivity was demonstrated in the reaction using not only simple substrate but also natural products, bearing multiple reaction sites. Moreover, based on the mechanistic studies, the iridium-catalyzed unique C-H insertion reaction involved rate-determining asynchronous concerted processes.

Lanostane triterpenoids from cultivated fruiting bodies of basidiomycete Ganoderma mbrekobenum

In the quest for medicinally active compounds in mushrooms of the genus Ganoderma, eleven undescribed lanostane triterpenoids, including a novel chlorinated derivative, i.e., (20S,24E)-21-chloro-15β,20,29-trihydroxy-3,7,11-trioxolanosta-8,24-dien-26-oic acid, were isolated from artificially cultivated fruiting bodies of the basidiomycete Ganoderma mbrekobenum. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The configuration of the C-20 atom in the most abundant 20-hydroxy-lanostane, (20S,24E)-15β,20,29-trihydroxy-3,7,11-trioxolanosta-8,24-dien-26-oic acid, was established by chemical derivatization, and the absolute configuration of the lanostane skeleton was determined by ECD calculation. Two of the undescribed compounds exhibited moderate antimalarial activity.

Integrated Experimental and Computational Studies on the Organocatalytic Kinetic Resolution of β-Unfunctionalized Primary Alcohols Using a Chiral 1,2-Diamine: The Importance of Noncovalent Interactions

The enantioselective kinetic resolution of β-unfunctionalized primary alcohols with benzoyl chloride was carried out in the presence of a catalytic amount of a novel chiral 1,2-diamine derived from (S)-proline. Several valuable chiral 2-substituted propan-1-ols were obtained with good enantioselectivities. Density functional theory calculations revealed that the noncovalent interaction, such as CH-π interaction, is crucial for the enantioselectivity of the resolution. This study was conducted through an interplay between experiment and computation.

Superomedial pedicle skin-reducing mastectomy in ptotic and large-sized breasts with two-stage reconstruction through transaxillary video-assisted technique: An effective surgical and anesthetic approach

Introduction

Skin-reducing mastectomy has been applied to several surgical techniques in which subcutaneous mastectomy is associated with various types of skin reduction, with preservation of a lower dermal flap to reinforce the inferior lateral seat of an implant. The aim of the study is to present a case series of patients with pendulous/ptotic and/or large-sized breasts treated for breast cancer at the Breast Surgery Unit of Istituto Nazionale Tumori IRCCS Fondazione "G. Pascale", Naples, Italy, with the superomedial pedicle skin-reducing mastectomy technique, two-stage reconstruction, and transaxillary video-assisted technique, when a postoperative radiotherapy was indicated. We verified its effectiveness by discussing its results, especially in patients who are candidates for postmastectomy radiotherapy.

Materials and methods

A single-center retrospective study was performed between January 2020 and March 2021 on a prospectively filled database of conservative mastectomies. Of the 64 patients who underwent nipple/skin-sparing mastectomies in the mentioned period, 17 (mean age 46 years, range 30-62 years) were treated with superomedial pedicle skin-reducing mastectomy, with two-stage breast reconstruction through transaxillary video-assisted replacement expander with definitive prosthesis and contralateral symmetrization, selected for postmastectomy radiotherapy.

Results

We had only three minor complications. No flap necrosis, no infections, no breast seromas, and no reconstructive failures were observed. During follow-up of the patients treated with video-assisted reconstruction, there were no cases of infection, hematoma, implant rupture, or suture dehiscence in the reconstructed breast.

Discussion

Skin-reducing mastectomy with superomedial pedicle is a safe and reliable procedure to treat breast cancer in selected patients, i.e., those with pendulous/ptotic and or large-sized breasts. Particularly, in patients who undergo postmastectomy radiotherapy, the two-stage reconstruction with video-assisted transaxillary endoscopic approach can find its main indication, using incisions positioned far from the mammary region, offering numerous advantages.

Reaction Path Determination of Rhodium(I)-Catalyzed C-H Alkylation of N-8-Aminoquinolinyl Aromatic Amides with Maleimides

The rhodium(I)-catalyzed reaction of N-8-aminoquinolinyl aromatic amides with maleimides results in C-H alkylation at the ortho position of the amide. The reaction path and formation of the alkylation product with density functional theory (DFT) calculations were done. The detailed computational study showed that the reaction proceeds in the following steps: (I) deprotonation of the NH amide proton, (II) oxidative addition of the ortho C-H bond, (III) migratory insertion of the maleimide, (IV) reductive elimination with the C-C bond formation, and (V) protonation. The energetic span model showed that the turnover frequency (TOF)-determining transition state (TDTS) is the oxidative addition, while the TOF-determining intermediate (TDI) is the formation of an Rh(I)-complex after N-H deprotonation. It was also found that the change in the oxidation number of the Rh catalyst is a key determinant of the reaction path.

A randomized, controlled trial of once-weekly teriparatide injection versus alendronate in patients at high risk of osteoporotic fracture: primary results of the Japanese Osteoporosis Intervention Trial-05

In this randomized, controlled trial, treatment with once-weekly subcutaneous injection of teriparatide for 72 weeks was found to be associated with a significant reduction in the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

INTRODUCTION

To determine whether the anti-fracture efficacy of teriparatide is superior to that of alendronate, a prospective, randomized, open-label, blinded-endpoint trial was performed.

METHODS

Japanese women aged at least 75 years were eligible for the study if they had primary osteoporosis and were at high risk of fracture. Patients were randomly assigned in a 1:1 ratio to receive sequential therapy (once-weekly subcutaneous injection of teriparatide 56.5 μg for 72 weeks followed by alendronate for 48 weeks) or monotherapy with alendronate for 120 weeks. The primary endpoint was the incidence of morphometric vertebral fractures at 72 weeks (at the end of teriparatide treatment).

RESULTS

Between October 2014 and December 2017, 1011 patients (505 in the teriparatide group and 506 in the alendronate group) were enrolled. Of these, 778 patients (351 and 427, respectively) were included in the primary analysis. The incidence of morphometric vertebral fractures was significantly lower in the teriparatide group (56 per 419.9 person-years, annual incidence rate 0.1334) than in the alendronate group (96 per 553.6 person-years, annual incidence rate 0.1734), with a rate ratio of 0.78 (95% confidence interval 0.61 to 0.99, P = 0.04). In both groups, adverse events were most frequently reported in the following system organ classes: infections and infestations, gastrointestinal disorders, and musculoskeletal and connective tissue disorders.

CONCLUSION

Once-weekly subcutaneous injection of teriparatide significantly reduced the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

TRIAL REGISTRATION

jRCTs031180235 and UMIN000015573, March 12, 2019.

Calculation of CYP450 protein-ligand binding and dissociation free energy paths

The function of an enzyme depends on its dynamic structure, and the catalytic mechanism has long been an active focus of research. The principle for interpreting protein selectivity and fidelity stems from optimization of the active site upon protein-substrate complexation, i.e., a lock-and-key configuration, on which most protein-substrate molecule binding recognition, and hence drug discovery, relies. Yet another thought has been to incorporate the protein folding interior tunnels for stereo- and regio-selectivity along the protein-substrate or protein-ligand/inhibitor binding process. Free energy calculations provide valuable information for molecular recognition and protein-ligand binding dynamics and kinetics. In this study, we focused on the kinetics of cytochrome P450 proteins (CYP450s) and the protein interior tunnel structure-dynamics relationship in terms of the substrate binding and leaving mechanism. A case in point is given by the prostaglandin H₂ (PGH₂) homologous isomerase of prostacyclin synthase. To calculate the reactant and product traversing the tunnels to and from the heme site, the free energy paths and tunnel potentials of mean force are constructed from steered molecular dynamics simulations and adaptive basing force umbrella sampling simulations. We explore the binding tunnels and critical residue lining characteristics for the ligand traverse and the underlying mechanism of CYP450 activity. Our theoretical analysis provides insights into the decisive role of the substrate tunnel binding process of the CYP450 mechanism and may be useful in drug design and protein engineering contexts.

Combined Computational and Experimental Studies on the Asymmetric Michael Addition of α-Aminomaleimides to β-Nitrostyrenes Using an Organocatalyst Derived from Cinchona Alkaloid

Maleimides are often used as electrophiles in conventional reactions; however, their application as nucleophiles is limited to only a few reactions, and reactions utilizing α-aminomaleimides as asymmetric Michael donors have not been reported to date. Thus, in this work, asymmetric Michael addition of α-aminomaleimides as Michael donors to β-nitrostyrenes was conducted for the first time using an organocatalyst derived from a Cinchona alkaloid. Density functional theory investigations were crucial to improve the enantioselectivity of the adduct.

AB0252 EFFICACY OF A SECOND JANUS KINASE INHIBITOR THAT WAS SWITCHED FOR DIFFICULT-TO-TREAT RA IN CLINICAL PRACTICE

Background:

In clinical practice, when refractory rheumatoid arthritis (RA) is present, of which the definition implies previous use of at least two biologic disease-modifying antirheumatic drugs (bDMARDs) (generally tumour necrosis factor inhibitors (TNFis)), the next treatment choice often made is a bDMARD of another class (non-TNFis) [1]. However, patients who are inadequately responding to bDMARDs need new treatment options because subsequent bDMARDs treatment reduces their response [2]. Janus Kinase inhibitors (JAKis) are the first targeted synthetic DMARDs (tsDMARD) licensed for the treatment of RA with comparable efficacy to bDMARDs. Unlike the single cytokine targeting approach of bDMARDs, JAKis are specifically designed to inhibit intracellular signalling molecules common to the receptors of multiple inflammatory cytokines implicated in RA pathogenesis. The choice of therapeutic agents for refractory RA is increasing, and its efficacy is expected. On the other hand, it is also true that some patients discontinued JAKis at a rate that cannot be overlooked because of insufficient efficacy. Difficult-to-treat (D2T) RA is defined as refractory to two or more b/ts DMARDs with different mechanisms of action, with active and progressive disease, as published by Eular(3)

Objectives:

To evaluate real world efficacy of approved JAKis switching in patients with D2T RA who were unable to control their disease activity due to insufficient efficacy despite the sequential use of multiple bDMARDs and JAKis, focusing on the drug retention rate.

Methods:

In our hospital, RA was diagnosed according to the 1987 or 2010 classification criteria, and when two or more bDMARDs (including both TNFis and non-TNFis) were inadequately effective, it was defined as D2T RA. We retrospectively investigated patients who switched to JAKis for D2T RA. The drug retention rate was investigated by the Kaplan-Meier method, and the difference was tested by the Logrank test.

Results:

The 1-year retention rate of JAKis for D2T RA was 50.8% in TOF 38 cases [28 women, age average 70.2 years, disease duration average 12.4 years, past bDMARDs use average 3.5 drugs, MTX combination 9 cases, DAS28 ESR average 4.11] and 66.3% in BAR 35 cases [26 cases, 73.0 years old, 14.8 years, 4.17 agents, 9 cases, 3.68], and there was no significant difference (P = 0.30). Among them, there were 17 cases [11 cases, 70.6 years old, 13.5 years, 4.18 drugs, 2 cases, 3.65] of switching between JAKis, all of which were switching from TOF to BAR. The 1-year retention rate was 45.8% [reason for discontinuation: insufficient effect in 3 cases, adverse events in 6 cases], which was not significantly different but tended to be lower than 72.7% [reason for discontinuation: insufficient effect in 1 case, adverse event in 2 cases, patient’s convenience in 1 case] in 16 patients [13 cases, 76.3 years old, 17.1 years, 3.19 drugs, 7 cases, 3.69] who received BAR as the first JAKi for D2T RA patients (P = 0.089).

Conclusion:

Although the number of cases is small in the retrospective survey, it is suggested that the retention rate of BAR switched to D2T RA may be slightly lower in patients with a history of TOF discontinuation due to insufficient efficacy than in JAKi naive patients. It is expected that the number of new JAKi usage cases will increase in the future, and it is necessary to consider switching between other JAKis in addition to switching from BAR to TOF.

References:

[1]Smolen JS, Landewe R, Bijlsma J et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 update. Ann Rheum Dis 2017;76:960_77.

[2]Rendas-Baum R, Wallenstein GV, Koncz T et al. Evaluating the efficacy of sequential biologic therapies for rheumatoid arthritis patients with an inadequate response to tumor necrosis factor-α inhibitors. Arthritis Res Ther 2011;13:R25.

[3]Nagy G, et al. EULAR definition of difficult-to-treat rheumatoid arthritis. Ann Rheum Dis 2021;80:31–35. doi:10.1136/annrheumdis-2020-217344.

Disclosure of Interests:

None declared

POS0088 EFFICACY OF JANUS KINASE INHIBITORS FOR DIFFICULT-TO-TREAT RA IN CLINICAL PRACTICE

Background:

In 20-30% of rheumatoid arthritis (RA) patients, the first biologic disease-modifying antirheumatic drugs (bDMARDs) (generally tumour necrosis factor inhibitors (TNFis)) is ineffective, and among the patients who do respond to therapy, 20% is faced with secondary ineffectiveness within the first 2 years of treatment [1]. In practice, when refractory RA is present, of which the definition implies previous use of at least two bDMARDs (generally TNFis), the next treatment choice often made is a bDMARD of another class (non-TNFis) [2]. On the other hand, patients who are inadequately responding to bDMARDs need new treatment options because subsequent bDMARD treatment reduces their response [3]. Janus Kinase inhibitors (JAKis) are the first targeted synthetic DMARDs (tsDMARD) licensed for the treatment of RA with comparable efficacy to bDMARDs. Unlike the single cytokine targeting approach of bDMARDs, JAKis are specifically designed to inhibit intracellular signalling molecules common to the receptors of multiple inflammatory cytokines implicated in RA pathogenesis.

Objectives:

Difficult-to-treat (D2T) RA is defined as refractory to two or more b/ts DMARDs with different mechanisms of action, with active and progressive disease, as published by Eular(4). We evaluated real world efficacy of approved JAKis and factors that may help to continue them in patients with D2T RA.

Methods:

Patients who had inadequate response to two or more bDMARDs (including both TNFis and non-TNFis) at our hospital by December 2019 were defined as D2T RA, and patients who switched to JAKis were retrospectively investigated. The drug retention rate was determined by Kaplan-Meier method, and the difference was tested by Logrank test. Multiple regression analysis was used as the statistical method to predict continuation of JAKis for more than 1 year, with patient background (age, gender, during the disease, number of bDMARDs used, with or without methotrexate and/or glucocorticoids, disease activity score assessing 28 joints using erythrocyte sedimentation rate’ presence of rheumatoid factor/anti-CCP antibody, matrix metalloproteinase 3 value, Health Assessment Questionnaire disability index) at the time of initiation as an explanatory variable.

Results:

A total of 915 bDMARDs had been administered to 394 RA patients. The retention rate of bDMARDs and the number of bDMARDs used were 89.3% and 1.48 bDMARDs at 1 year, 67.7% and 2.27 bDMARDs at 5 years, and 52.0% and 3.15 bDMARDs at 10 years, respectively. The retention rate of JAKis at 1 year was 60.2% in 65 patients with tofacitinib (TOF) and 67.2% in 70 patients with baricitinib (BAR) (P=0.38). Among them, the drug retention rate in D2T RA patients was 50.8% in 38 TOF patients and 66.3% in 35 BAR patients with no significant difference (P=0.30). There were no patient background factors that significantly predicted continuation at 1 year for any JAKis.

Conclusion:

Despite the limited number of patients and the retrospective nature of the study, TOF and BAR were shown to be effective options for D2T RA, regardless of patient background such as disease activity or number of bDMARDs used. Other JAKis and switches between JAKis need to be investigated in the future.

References:

[1]Schaeverbeke T, Truchetet ME, Kostine M et al. Immunogenicity of biologic agents in rheumatoid arthritis patients: lessons for clinical practice. Rheumatology 2016;55:210_20.

[2]Smolen JS, Landewe R, Bijlsma J et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 update. Ann Rheum Dis 2017;76:960_77.

[3]Rendas-Baum R, Wallenstein GV, Koncz T et al. Evaluating the efficacy of sequential biologic therapies for rheumatoid arthritis patients with an inadequate response to tumor necrosis factor-α inhibitors. Arthritis Res Ther 2011;13:R25.

[4]Nagy G, et al. EULAR definition of difficult-to-treat rheumatoid arthritis. Ann Rheum Dis 2021;80:31–35. doi:10.1136/annrheumdis-2020-217344.

Disclosure of Interests:

None declared

Combined MD and QM/MM Investigations of Hydride Reduction of 5α-Dihydrotestosterone Catalyzed by Human 3α-Hydroxysteroid Dehydrogenase Type 3: Importance of Noncovalent Interactions

3α-Hydroxysteroid dehydrogenase (3α-HSD) is an enzyme that is essential in the regulation of the concentration of 5α-dihydrotestosterone (5α-DHT) in the prostate. It catalyzes the hydride reduction of 5α-DHT to 3α-androstanediol, which activates androgen receptors. Elucidating details about the hydride reduction of 5α-DHT by 3α-HSD and the environment around the active site of the enzyme could lead to the development of effective drugs for the treatment of prostate cancer. In this study, the X-ray crystal structure of human 3α-HSD type 3 was comprehensively evaluated. Moreover, molecular dynamics (MD) simulations and hybrid ONIOM-type quantum mechanics/molecular mechanics (QM/MM) calculations were performed using a large QM region (maximum 232 atoms). It was determined that the reaction proceeded in a single step without the formation of an alkoxide ion owing to the direct hydride reduction of the substrate by nicotinamide adenine dinucleotide phosphate (NADPH) and concerted proton transfer by Tyr55 and Lys84. Noncovalent interaction (NCI) analysis highlighted the roles of Tyr216 and Trp227 in 3α-HSD. Specifically, Tyr216 assisted the reaction by π/π interactions with the neighboring nicotinamide ring of NADP(H), whereas Trp227 played an important role in recognition of the size of the substrate by CH/π interactions.

The synthetic peptide SVVYGLR promotes myogenic cell motility via the TGFβ1/Smad signaling pathway and facilitates skeletal myogenic differentiation in vitro

In the present study, we investigated the possible involvement of the TGF-β/Smad signaling pathway in the osteopontin-derived SVVYGLR (SV) peptide-mediated migratory activities of myogenic cells and evaluated the facilitative effects of the SV peptide on the differentiation of myogenic cells in vitro. The SV peptide-induced migration in both human-derived satellite cells and myoblasts was substantially suppressed by the TGF-β1 receptor inhibitor SB431542 or SB505124. Besides, the expression level of the Smad3 phosphorylation was further enhanced by the addition of the SV peptide in comparison with control groups. Furthermore, an increase in the expression of myogenin-positive nuclei and a higher number of nascent myotubes with myosin heavy chain expression was confirmed in cultured myoblasts supplemented with the SV peptide. These results suggest that the involvement of the TGF-β/Smad signaling pathway in the SV peptide-mediated migration and the facilitative effect of the SV peptide on the differentiation of myogenic cells into myotubes.

The synthetic peptide SVVYGLR promotes cell motility of myogenic cells and facilitates differentiation in skeletal muscle regeneration

The present study was designed to evaluate the effects of the osteopontin-derived multifunctional short peptide, SVVYGLR (SV) peptide on the biological properties of skeletal muscle-specific myogenic cells. We employed human-derived satellite cells (HSkMSC) and skeletal muscle myoblasts (HSMM) and performed a series of biochemical experiments. The synthetic SV peptide showed no influence on the proliferation and adhesion properties of HSkMSC and HSMM, while it showed a significant increase in cell motility, including migration activities upon treatment with the SV peptide. In a rat model with volumetric loss of masticatory muscle, immunohistochemical staining of regenerating muscle tissue immediately after injury demonstrated an increase of the number of both MyoD- and myogenin-positive cells in SV peptide-treated group. These results suggest that SV peptide plays a potent role in facilitating skeletal muscle regeneration by promoting the migration, and differentiation of myogenic precursor and progenitor cells.

Synthetic peptide SVVYGLR upregulates cell motility and facilitates oral mucosal wound healing

Osteopontin-derived SVVYGLR (SV) 7-amino-acid sequence is a multifunctional and synthetic SV peptide implicated in angiogenesis, production of collagen III, and fibroblast differentiation into myofibroblasts. This study investigated the effect of the SV peptide on mucosal wound healing activity. Normal human-derived gingival fibroblasts (NHGF) and human oral mucosa keratinocytes (HOMK) were used for in vitro experiments. In addition, an oral punch wound was prepared at the buccal mucosa in male rats aged 11 weeks, and we evaluated the effect of local injection of SV peptide on wound healing. The synthetic SV peptide showed no influence on the proliferation and adhesion properties of NHGF and HOMK, but it enhanced the cell motility and migration activities. TGF-β1 receptor inhibitor, SB431542 or SB505124, substantially suppressed the SV peptide-induced migration activity, suggesting an involvement of TGF-β1 receptor activation. Furthermore, SV peptide accelerated the healing process of an in vivo oral wound model, compared with control groups. Further immunohistological staining of wound tissue revealed that an increase in capillary growth and the greater number of fibroblasts and myofibroblasts that migrated into the wound area might contribute to the facilitation of the healing process produced by the SV peptide. The SV peptide has beneficial effects on oral wound healing through enhancement of the earlier phase consisting of angiogenesis and remodeling with granulation tissue. The synthetic SV peptide can be a useful treatment option, particularly for intractable mucosal wounds caused by trauma or surgery for progressive lesions such as oral cancer.

Occurrence and clinical course of peri-stent contrast staining: comparison between second-generation drug-eluting stents and third generation drug-eluting stents

Background

Peri-stent contrast staining (PSS) has been reported to be associated with very late stent thrombosis.

The aims of this study was to compare the occurrence rate of PSS between second generation drug-eluting stents (2nd DES) and third generation drug-eluting stents (3rd DES), and to identify clinical characteristics associated with PSS.

Methods and results

This study comprised 1899 patients with 2493 de novo lesions treated with 2nd or 3rd DES from October 2015 to September 2018. Follow-up angiography was available for 1883 lesions (75.5%). There were 725 patients with 968 lesions treated with 2nd DES, and 716 patients with 915 lesions treated with 3rd DES. The occurrence of PSS, types of PSS, and VLST related to PSS were compared between 2nd and 3rd DES implantation. Mean follow-up period was 30±12 months. The occurrence rate of PSS and segmental type of PSS were similar between two groups (2nd DES vs. 3rd DES, 1.5% vs. 1.7%, p=0.73, 47% vs. 50%, p=0.85, and respectively). The VLST related to PSS occurred in only one case in 3rd DES group. (0% vs. 6.3%, p=0.33).

Conclusion

The occurrence rate of PSS and clinical course were similar between 2nd and 3rd DES.

Funding Acknowledgement

Type of funding source: None

Highly Modified Lanostane Triterpenes from the Wood-Rot Basidiomycete Ganoderma colossus: Comparative Chemical Investigations of Natural and Artificially Cultivated Fruiting Bodies and Mycelial Cultures

The wood-rot basidiomycete Ganoderma colossus has been chemically investigated. Comparative analyses of the natural fruiting body, artificially cultivated fruiting bodies, and mycelial cultures resulted in the isolation, in total, of 13 new highly modified lanostanes, ganocolossusins A-H (1-8) and ganodermalactones T-X (9-13), together with 23 known compounds (14-36). There were significant overlaps of the same compounds among the three different states of the fungal materials. Ganocolossusin D (4) displayed the most potent antimalarial activity against Plasmodium falciparum K1 (multi-drug-resistant strain) with an IC₅₀ value of 2.4 μM, while it was noncytotoxic to Vero cells at 50 μg/mL.

P5022Dual-energy CT was effective to evaluate of microvasculopathy in chronic thromboembolic pulmonary hypertension

Background

The existence of microvasculopathy in patients with chronic thromboembolic pulmonary hypertension (CTEPH) had been suggested. However, the impact of microvasculopathy for pathophysiology had been unknown. Recently dual-energy CT (DECT) can produce a sensitive iodine distribution map as blood perfusion in lung fields to quantify lung perfusion, also can suggest the existence of microvasculopathy according to poor subpleural perfusion which was published previously.

Methods

We retrospectively reviewed poor subpleural perfusion (defined as subpleural spaces either not or minimally perfused in all segments) and hemodynamics of 83 treatment-naïve CTEPH patients who underwent DECT from February 2014 to Jan 2019. Patients were divided according to poor subpleural perfusion: a microvasculopathy group (n=44) or a non-microvasculopathy group (n=39).

We assessed cardiopulmonary exercise test, right heart catheterization and DECT parameters as quantitative evaluation of pulmonary blood volume (PBV). PBV was calculated as the average of entire lung iodine density.

Results

PBV value in non-microvasculopathy group showed significant inverse correlation with pulmonary vascular resistance (PVR) (y = 14236 x-1.028 r=−0.530, p<0.01).

PBV, SvO2, and %DLCO/VA were significantly lower (22.0 vs. 26.4, p<0.01, 61.3 vs. 66.0, p<0.01, and 59.2 vs 75.9 p<0.01), and systolic pulmonary arterial pressure, PVR, VE/VCO2 slope, BNP were higher (69.3 vs 60.6 p=0.04, 834 vs 586 p<0.01, 45.5 vs. 37.8, p=0.02, and 440 vs 122 p=0.04) in microvasculopathy group, while the other parameters were similar between the two groups.

Multivariate analysis revealed that %DLCO/VA was the only predictor of microvasculopathy (OR,0.895 [95% CI, 0.835 - 0.960]; P<0.01).

Conclusion

Pulmonary blood flow of patients in non-micorvasculopathy group showed inverse correlation with PVR. DECT was effective to assess the microvasculopathy in CTEPH. In our experience, less than 60% of non-operable CTEPH patients have microvasculopathy.

Mechanical regulation of bone homeostasis through p130Cas-mediated alleviation of NF-κB activity

Mechanical loading plays an important role in bone homeostasis. However, molecular mechanisms behind the mechanical regulation of bone homeostasis are poorly understood. We previously reported p130Cas (Cas) as a key molecule in cellular mechanosensing at focal adhesions. Here, we demonstrate that Cas is distributed in the nucleus and supports mechanical loading-mediated bone homeostasis by alleviating NF-κB activity, which would otherwise prompt inflammatory processes. Mechanical unloading modulates Cas distribution and NF-κB activity in osteocytes, the mechanosensory cells in bones. Cas deficiency in osteocytes increases osteoclastic bone resorption associated with NF-κB-mediated RANKL expression, leading to osteopenia. Upon shear stress application on cultured osteocytes, Cas translocates into the nucleus and down-regulates NF-κB activity. Collectively, fluid shear stress-dependent Cas-mediated alleviation of NF-κB activity supports bone homeostasis. Given the ubiquitous expression of Cas and NF-κB together with systemic distribution of interstitial fluid, the Cas-NF-κB interplay may also underpin regulatory mechanisms in other tissues and organs.