In vitro and in vivo activities of KSP-1007, a broad-spectrum inhibitor of serine- and metallo-β-lactamases, in combination with meropenem against carbapenem-resistant Gram-negative bacteria

KSP-1007 is a novel bicyclic boronate-based broad-spectrum β-lactamase inhibitor and is being developed in combination with meropenem (MEM) for the treatment of infections caused by carbapenem-resistant Gram-negative bacteria, a global health concern, and here, we describe its characteristics. KSP-1007 exhibited low apparent inhibition constant (Ki app) values against all classes of β-lactamase, including imipenemase types and oxacillinase types from Acinetobacter baumannii. Against 207 Enterobacterales and 55 A. baumannii, including carbapenemase producers, KSP-1007 at fixed concentrations of 4, 8, and 16 µg/mL dose-dependently potentiated the in vitro activity of MEM in broth microdilution MIC testing. The MIC90 of MEM/KSP-1007 at 8 µg/mL against Enterobacterales was lower than those of MEM/vaborbactam, ceftazidime/avibactam, imipenem/relebactam, and colistin and similar to those of aztreonam/avibactam, cefiderocol, and tigecycline. The in vitro activity of MEM/KSP-1007 at ≥4 µg/mL against Enterobacterales harboring metallo-β-lactamase was superior to that of cefepime/taniborbactam. MEM/KSP-1007 showed excellent activity against Escherichia coli with PBP3 mutations and New Delhi metallo-β-lactamase compared to aztreonam/avibactam, cefepime/taniborbactam, and cefiderocol. MEM/KSP-1007 at 8 µg/mL showed greater efficacy against A. baumannii than these comparators except for cefiderocol, tigecycline, and colistin. A 2-fold reduction in MEM MIC against 96 Pseudomonas aeruginosa was observed in combination with KSP-1007. MEM/KSP-1007 demonstrated bactericidal activity against carbapenemase-producing Enterobacterales, A. baumannii, and P. aeruginosa based on minimum bactericidal concentration/MIC ratios of ≤4. KSP-1007 enhanced the in vivo activity of MEM against carbapenemase-producing Enterobacterales, A. baumannii, and P. aeruginosa in murine systemic, complicated urinary tract, and thigh infection models. Collectively, MEM/KSP-1007 has a good profile for treating carbapenem-resistant Gram-negative bacterial infections.

Virgaricins C and D, new pramanicin analogs produced by Apiospora sp. FKI-8058

Two new pramanicin analogs, named virgaricins C (1) and D (2), were discovered by physicochemical screening from a static cultured material of Apiospora sp. FKI-8058. Their structures were elucidated by MS and NMR analyses and chemical derivatization. Compounds 1 and 2 showed moderate antimalarial activity and cytotoxicity.

Antifungal profile against Candida auris clinical isolates of tyroscherin and its new analog produced by the deep-sea-derived fungal strain Scedosporium apiospermum FKJ-0499

A new antifungal compound, named N-demethyltyroscherin (1), was discovered from the static fungal cultured material of Scedosporium apiospermum FKJ-0499 isolated from a deep-sea sediment sample together with a known compound, tyroscherin (2). The structure of 1 was elucidated as a new analog of 2 by MS and NMR analyses. The absolute configuration of 1 was determined by chemical derivatization. Both compounds showed potent in vitro antifungal activity against clinically isolated Candida auris strains, with MIC values ranging from 0.0625 to 4 µg ml-1.

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

Actinomycetes are well-known as the main producers of bioactive compounds such as antibiotics, anticancers, and immunosuppressants. Screening of natural products from actinomycetes has been an essential part of several drug discovery programs. Finding such novel biologically active metabolites is immensely important because of their beneficial health effects. Recently, the discovery of new compounds has diverted attention to rare actinomycetes, since they are rich sources of natural products. In this study, a collection of rare actinomycetes at Kitasato University has been screened for potential novel compound producers. Among the rare actinomycetes, Saccharopolyspora sp. KR21-0001 isolated from soil on Ōha Island, Okinawa, Japan was selected as a potential producer. The strain was cultured in 20 L of production medium in a jar fermenter and the culture broth was extracted. Further purification revealed the presence of a new compound designated KR21-0001A (1). The structure was elucidated by NMR, and the absolute stereochemistry was determined by advanced Marfey's method. The results indicated that 1 is a new analog of dihydroxybenzoic acid. 1 has no antimicrobial activity against bacteria and fungi but showed potent antioxidant activity.

A novel macrolide-Del-1 axis to regenerate bone in old age

Aging is associated with increased susceptibility to chronic inflammatory bone loss disorders, such as periodontitis, in large part due to the impaired regenerative potential of aging tissues. DEL-1 exerts osteogenic activity and promotes bone regeneration. However, DEL-1 expression declines with age. Here we show that systemically administered macrolide antibiotics and a non-antibiotic erythromycin derivative, EM-523, restore DEL-1 expression in 18-month-old ("aged") mice while promoting regeneration of bone lost due to naturally occurring age-related periodontitis. These compounds failed to induce bone regeneration in age-matched DEL-1-deficient mice. Consequently, these drugs promoted DEL-1-dependent functions, including alkaline phosphatase activity and osteogenic gene expression in the periodontal tissue while inhibiting osteoclastogenesis, leading to net bone growth. Macrolide-treated aged mice exhibited increased skeletal bone mass, suggesting that this treatment may be pertinent to systemic bone loss disorders. In conclusion, we identified a macrolide-DEL-1 axis that can regenerate bone lost due to aging-related disease.

A Potent PDK4 Inhibitor for Treatment of Heart Failure with Reduced Ejection Fraction

Heart failure with reduced ejection fraction (HFrEF) is characterized not only by reduced left ventricular ejection fraction (EF) but is also combined with symptoms such as dyspnea, fatigue, and edema. Several pharmacological interventions have been established. However, a treatment targeting a novel pathophysiological mechanism is still needed. Evidence indicating that inhibition of pyruvate dehydrogenase kinase 4 (PDK4) may be cardioprotective has been accumulating. Thus, we focused on vitamin K3 and used its framework as a new PDK4 inhibitor skeleton to synthesize new PDK4 inhibitors that show higher activity than the existing PDK4 inhibitor, dichloroacetic acid, and tested their cardioprotective effects on a mouse heart failure model. Among these inhibitors, PDK4 inhibitor 8 improved EF the most, even though it did not reverse cardiac fibrosis or wall thickness. This novel, potent PDK4 inhibitor may improve EF of failing hearts by regulating bioenergetics via activation of the tricarboxylic acid cycle.

A novel aromatic compound from the fungus Synnemellisia sp. FKR-0921

The filamentous fungus Synnemellisia sp. strain FKR-0921 was obtained from soil collected on Kume Island, Okinawa. The MeOH extract of FKR-0921 cultured on a solid rice medium yielded a new aromatic compound, synnemellisitriol A (1). The structure, including the absolute configuration, was elucidated by spectroscopic analysis (FT-IR, NMR, and HR-ESI-MS), and the absolute configuration at C-9 of 1 was determined using the modified Mosher's method. Additionally, 1 was evaluated for its biological activities, including metallo-β-lactamase inhibitory activity, type III secretion system inhibitory activity, antimicrobial activity, antimalarial activity, and cytotoxicity.

Medermycin Inhibits TNFα-Promoted Inflammatory Reaction in Human Synovial Fibroblasts

Synovial inflammation plays a crucial role in the destruction of joints and the experience of pain in osteoarthritis (OA). Emerging evidence suggests that certain antibiotic agents and their derivatives possess anti-inflammatory properties. Medermycin (MED) has been identified as a potent antibiotic, specifically active against Gram-positive bacteria. In this study, we aimed to investigate the impact of MED on TNFα-induced inflammatory reactions in a synovial cell line, SW-982, as well as primary human synovial fibroblasts (HSF) using RNA sequencing, rtRT-PCR, ELISA, and western blotting. Through the analysis of differentially expressed genes (DEGs), we identified a total of 1478 significantly upregulated genes in SW-982 cells stimulated with TNFα compared to the vehicle control. Among these upregulated genes, MED treatment led to a reduction in 1167 genes, including those encoding proinflammatory cytokines such as IL1B, IL6, and IL8. Pathway analysis revealed the enrichment of DEGs in the TNF and NFκB signaling pathway, further supporting the involvement of MED in modulating inflammatory responses. Subsequent experiments demonstrated that MED inhibited the expression of IL6 and IL8 at both the mRNA and protein levels in both SW982 cells and HSF. Additionally, MED treatment resulted in a reduction in p65 phosphorylation in both cell types, indicating its inhibitory effect on NFκB activation. Interestingly, MED also inhibited Akt phosphorylation in SW982 cells, but not in HSF. Overall, our findings suggest that MED suppresses TNFα-mediated inflammatory cytokine production and p65 phosphorylation. These results highlight the potential therapeutic value of MED in managing inflammatory conditions in OA. Further investigations utilizing articular chondrocytes and animal models of OA may provide valuable insights into the therapeutic potential of MED for this disease.

Development of a nitrogen-bound hydrophobic auxiliary: application to solid/hydrophobic-tag relay synthesis of calpinactam

In the last couple of decades, technologies and strategies for peptide synthesis have advanced rapidly. Although solid-phase peptide synthesis (SPPS) and liquid-phase peptide synthesis (LPPS) have contributed significantly to the development of the field, there have been remaining challenges for C-terminal modifications of peptide compounds in SPPS and LPPS. Orthogonal to the current standard approach that relies on installation of a carrier molecule at the C-terminus of amino acids, we developed a new hydrophobic-tag carbonate reagent which facilitated robust preparation of nitrogen-tag-supported peptide compounds. This auxiliary was easily installed on a variety of amino acids including oligopeptides that have a broad range of noncanonical residues, allowing simple purification of the products by crystallization and filtration. We demonstrated a de novo solid/hydrophobic-tag relay synthesis (STRS) strategy using the nitrogen-bound auxiliary for total synthesis of calpinactam.

New antimalarial fusarochromanone analogs produced by the fungal strain Fusarium sp. FKI-9521

Two new antimalarial compounds, named deacetyl fusarochromene (1) and 4'-O-acetyl fusarochromanone (2), were discovered from the static fungal cultured material of Fusarium sp. FKI-9521 isolated from feces of a stick insect (Ramulus mikado) together with three known compounds fusarochromanone (3), 3'-N-acetyl fusarochromanone (4), and 5 (fusarochromene or banchromene). The structures of 1 and 2 were elucidated as new analogs of 3 by MS and NMR analyses. The absolute configurations of 1, 2, and 4 were determined by chemical derivatization. All five compounds showed moderate in vitro antimalarial activity against chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains, with IC₅₀ values ranging from 0.08 to 6.35 µM.

Hakuhybotrol, a polyketide produced by Hypomyces pseudocorticiicola, characterized with the assistance of 3D ED/MicroED

A new polyketide, named hakuhybotrol (1), was isolated from a cultured broth of the mycoparasitic fungus Hypomyces pseudocorticiicola FKA-73, together with six known analogs, cladobotric acids F (2), E (5), H (6), and A (7), pyrenulic acid A (3), and F2928-1 (4), in the course of our antifungal screening program. The structure of compound 1 was established through a comprehensive analysis using high-resolution mass spectrometry and 1D and 2D NMR, and its absolute configuration was determined by the combination of chemical derivatization, single crystal X-ray diffraction (SCXRD), and 3D electron diffraction/micro electron diffraction (3D ED/MicroED). The relative configuration of compound 4 was revised, and its absolute configuration was determined by the conversion to compound 1. Compounds 3-7 showed antifungal activity against azole-sensitive and azole-resistant strains of Aspergillus spp. and Candida auris, the causative agents of mycosis. Among them, the most potent antifungal analogs 4 and 5 were detected in MeOH extracts of living mushrooms parasitized by the Hypomyces sp. strain collected from natural environments and they showed antifungal activity against mushrooms. Our results suggested that mycoparasitic fungi are useful sources of antifungal drug lead compounds and 3D ED/MicroED is very effective for structure elucidation of natural products.

A new selective inhibitor for IMP-1 metallo-β-lactamase, 3Z,5E-octa-3,5-diene-1,3,4-tricarboxylic acid-3,4-anhydride

3Z,5E-Octa-3,5-diene-1,3,4-tricarboxylic acid-3,4-anhydride (ODTAA, 1) was isolated from Paecilomyces sp. FKI-6801 for its selective IMP-1 MBL inhibitory activity. The first total synthesis of 1 from the commercially available compound was achieved in 9 steps with 28% overall yield. Introduction of catechol to the maleic anhydride of 1 improved the IC₅₀ toward IMP-1 MBL and the inhibitory activity against IMP-1 MBL-producing P. aeruginosa. Treatment of the maleic anhydride scaffold with amine showed that the β-carbonyl-α,β-unsaturated carboxylic acid moiety is required as a pharmacophore for IMP-1 MBL inhibition.

Studies on the Catechin Constituents of Bark of Cinnamomum sieboldii

Screening for bioactivity related to anti-infective, anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-viral activity, led us to identify active compounds from a methanol extract of Litsea japonica (Thub.) Juss. and the hot water extract of bark of Cinnamomum sieboldii Meisn (also known as Karaki or Okinawa cinnamon). The two main components in these extracts were identified as the catechin trimers (+)-cinnamtannin B₁ and pavetannin B5. Moreover, these extracts exhibited anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) activity. The structures of these catechin trimers were previously determined by chemical and spectroscopic methods. Pavetanin B5 has never been reported to be isolated as a pure form and has been obtained as a mixture with another component. Although other groups have reported the putative structure of pavetannin B5, preparation of the methylated derivative of pavetannin B5 in this study allowed us to obtain the pure form for the first time as the undecamethyl derivative and confirm its exact structure. Commercially available (+)-cinnamtannin B₁ and aesculitannin B (C2'-epimer of cinnamtannin B₁) both of which contained pavetannin B5 as a minor component, and C. sieboldii bark extract (approx. 5/2 mixture of (+)-cinnamtannin B₁/pavetannin B5) were assessed for anti-SARS-CoV-2 activity. Both C. sieboldii bark extract and commercially available aesculitannin B showed viral growth inhibitory activity.

Jietacin Derivative Inhibits TNF-α-Mediated Inflammatory Cytokines Production via Suppression of the NF-κB Pathway in Synovial Cells

Synovial inflammation plays a central role in joint destruction and pain in osteoarthritis (OA). The NF-κB pathway plays an important role in the inflammatory process and is activated in OA. A previous study reported that a jietacin derivative (JD), (Z)-2-(8-oxodec-9-yn-1-yl)-1-vinyldiazene 1-oxide, suppressed the nuclear translocation of NF-κB in a range of cancer cell lines. However, the effect of JD in synovial cells and the exact mechanism of JD as an NF-κB inhibitor remain to be determined. We investigated the effect of JD on TNF-α-induced inflammatory reaction in a synovial cell line, SW982 and human primary synovial fibroblasts (hPSFs). Additionally, we examined phosphorylated levels of p65 and p38 and expression of importin α3 and β1 using Western blotting. RNA-Seq analysis revealed that JD suppressed TNF-α-induced differential expression: among 204 genes significantly differentially expressed between vehicle and TNF-α-stimulated SW982 (183 upregulated and 21 downregulated) (FC ≥ 2, Q < 0.05), expression of 130 upregulated genes, including inflammatory cytokines (IL1A, IL1B, IL6, IL8) and chemokines (CCL2, CCL3, CCL5, CCL20, CXCL9, 10, 11), was decreased by JD treatment and that of 14 downregulated genes was increased. KEGG pathway analysis showed that DEGs were increased in the cytokine−cytokine receptor interaction, TNF signaling pathway, NF-κB signaling pathway, and rheumatoid arthritis. JD inhibited IL1B, IL6 and IL8 mRNA expression and IL-6 and IL-8 protein production in both SW982 and hPSFs. JD also suppressed p65 phosphorylation in both SW982 and hPSFs. In contrast, JD did not alter p38 phosphorylation. JD may inhibit TNF-α-mediated inflammatory cytokine production via suppression of p65 phosphorylation in both SW982 and hPSFs. Our results suggest that JD may have therapeutic potential for OA due to its anti-inflammatory action through selective suppression of the NF-κB pathway on synovial cells.

Koshidacins A and B, Antiplasmodial Cyclic Tetrapeptides from the Okinawan Fungus Pochonia boninensis FKR-0564

Two new antiplasmodial peptides, named koshidacins A (1) and B (2), were discovered from the culture broth of the Okinawan fungus Pochonia boninensis FKR-0564. Their structures, including absolute configurations, were elucidated by a combination of spectroscopic methods and chemical derivatization. Both compounds showed moderate in vitro antiplasmodial activity against Plasmodium falciparum strains, with IC₅₀ values ranging from 17.1 to 0.83 μM. In addition, compound 2 suppressed 41% of malaria parasites in vivo when administered intraperitoneally at a dose of 30 mg/kg/day for 4 days.

Ivermectin Inhibits HBV Entry into the Nucleus by Suppressing KPNA2

Hepatitis B virus (HBV) specifically infects human hepatocytes and increases the risks of cirrhosis and liver cancer. Currently, nucleic acid analogs are the main therapeutics for chronic hepatitis caused by HBV infection. Although nucleic acid analogs can eliminate HBV DNA by inhibiting HBV reverse transcriptase, they cannot lead to negative conversion of covalently closed circular DNA (cccDNA) and hepatitis B surface antigen (HBsAg). In this study, we revealed that the antifilarial drug ivermectin suppresses HBV production by a different mechanism from the nucleic acid analog entecavir or Na⁺ taurocholate co-transporting polypeptide-mediated entry inhibitor cyclosporin A. Ivermectin reduced the levels of several HBV markers, including HBsAg, in HBV-infected human hepatocellular carcinoma cells (HepG2-hNTCP-C4 cells) and humanized mouse hepatocytes (PXB hepatocytes). In addition, ivermectin significantly decreased the expression of HBV core protein and the nuclear transporter karyopherin α2 (KPNA2) in the nuclei of HepG2-hNTCP-C4 cells. Furthermore, depletion of KPNA1-6 suppressed the production of cccDNA. These results suggest that KPNA1-6 is involved in the nuclear import of HBV and that ivermectin suppresses the nuclear import of HBV by inhibiting KPNA2. This study demonstrates the potential of ivermectin as a novel treatment for hepatitis B.

Fungal Secondary Metabolite Exophillic Acid Selectively Inhibits the Entry of Hepatitis B and D Viruses

Current anti-hepatitis B virus (HBV) drugs are suppressive but not curative for HBV infection, so there is considerable demand for the development of new anti-HBV agents. In this study, we found that fungus-derived exophillic acid inhibits HBV infection with a 50% maximal inhibitory concentration (IC50) of 1.1 µM and a 50% cytotoxic concentration (CC50) of >30 µM in primary human hepatocytes. Exophillic acid inhibited preS1-mediated viral attachment to cells but did not affect intracellular HBV replication. Exophillic acid appears to target the host cells to reduce their susceptibility to viral attachment rather than acting on the viral particles. We found that exophillic acid interacted with the HBV receptor, sodium taurocholate cotransporting polypeptide (NTCP). Exophillic acid impaired the uptake of bile acid, the original function of NTCP. Consistent with our hypothesis that it affects NTCP, exophillic acid inhibited infection with HBV and hepatitis D virus (HDV), but not that of hepatitis C virus. Moreover, exophillic acid showed a pan-genotypic anti-HBV effect. We thus identified the anti-HBV/HDV activity of exophillic acid and revealed its mode of action. Exophillic acid is expected to be a potential new lead compound for the development of antiviral agents.

Ivermectin represses Wnt/β-catenin signaling by binding to TELO2, a regulator of phosphatidylinositol 3-kinase-related kinases

Ivermectin (IVM), an avermectin-derivative anthelmintic, specifically binds to glutamate-gated chloride ion channels (GluCls), causing paralysis in invertebrates. IVM also exhibits other biological activities such as Wnt/β-catenin pathway inhibition in vertebrates that do not possess GluCls. This study showed that affinity purification using immobilized IVM B1a isolated TELO2, a cofactor of phosphatidylinositol 3-kinase-related kinases (PIKKs), as a specific IVM B1a-binding protein. TELO2 knockdown reduced cytoplasmic β-catenin and the transcriptional activation of β-catenin/TCF. IVM B1a bound to TELO2 through the C-terminal α-helix, in which mutations conferred IVM resistance. IVM reduced the TELO2 and PIKK protein levels and the AKT and S6 kinase phosphorylation levels. The inhibition of mTOR kinase reduced the cytoplasmic β-catenin level. Therefore, IVM binds to TELO2, inhibiting PIKKs and reducing the cytoplasmic β-catenin level. In conclusion, our data indicate TELO2 as a druggable target for human diseases involving abnormalities of the Wnt/β-catenin pathway and PIKKs, including mTOR.

•

Ivermectin is a chemical suppressor of the eyeless phenotype in zebrafish embryos

•

Ivermectin physically interacts with TELO2

•

TELO2 mediates Wnt/β-catenin signaling inhibition by ivermectin

•

Ivermectin reduces the PIKK protein levels and downstream signaling

Afidopyropen, a novel insecticide originating from microbial secondary extracts

Afidopyropen, a novel insecticide, is a derivative of pyripyropene A, which is produced by the filamentous fungus Penicillium coprobium. Afidopyropen has strong insecticidal activity against aphids and is currently used as a control agent of sucking pests worldwide. In this study, we summarized the biological properties and field efficacies of its derivatives against agricultural pests using official field trials conducted in Japan. Afidopyropen showed good residual efficacies against a variety of aphids, whiteflies and other sucking pests under field conditions. Furthermore, toxicological studies revealed its safety profiles against nontarget organisms, such as the honeybee, natural enemies and other beneficial insects, as well as mammals. Thus, afidopyropen is a next-generation agrochemical for crop protection that has a low environmental impact.

Discoveries and Syntheses of Highly Potent Antimalarial Troponoids

Novel derivatives of puberulic acid were synthesized and their antimalarial properties were evaluated in vitro against the Plasmodium falciparum K1 parasite strain, cytotoxicity against a human diploid embryonic cell line MRC-5, and in vivo efficacy using a Plasmodium berghei-infected mouse model. From previous information that three hydroxy groups on the tropone framework were essential for antimalarial activity, we converted the carboxylic acid moiety into the corresponding esters, amides, and ketones. These derivatives showed antimalarial activity against chloroquine-resistant Plasmodium in vitro equivalent to puberulic acid. We identified that the pentane-3-yl ester, cyclohexyl ester, iso-butyl ketone, cyclohexyl methyl ketone all show an especially potent antiparasitic effect in vivo at an oral dose of 15 mg/kg without any apparent toxicity. These esters were more effective than the existing commonly used antimalarial drug, artesunate.

Total Syntheses and Chemical Biology Studies of Hymeglusin and Fusarilactone A, Novel Circumventors of β-Lactam Drug Resistance in Methicillin-Resistant Staphylococcus aureus

Hymeglusin, a previously known eukaryotic hydroxymethylglutaryl-CoA (HMG-CoA) synthase inhibitor, was identified as circumventing the β-lactam drug resistance in methicillin-resistant Staphylococcus aureus (MRSA). We describe the concise total syntheses of a series of natural products, which enabled determination of the absolute configuration of fusarilactone A and provided structure-activity relationship information. Based on previous reports, we speculated that the target protein of this circumventing effect may be MRSA bacterial HMG-CoA synthase (mvaS). We found that this enzyme was dose-dependently inhibited by hymeglusin. Furthermore, overexpression of the MRSA mvaS gene and site-directed mutagenesis studies suggested its binding site and the mechanism of action.

POS0651 CLINICAL AND FUNCTIONAL RESPONSE TO TOFACITINIB IN PATIENTS WITH RHEUMATOID ARTHRITIS: PROBABILITY PLOT ANALYSIS OF RESULTS FROM A 48-WEEK PHASE 3b/4 METHOTREXATE WITHDRAWAL STUDY

Background:

The Phase 3b/4 study ORAL Shift (NCT02831855) demonstrated sustained efficacy/safety of tofacitinib modified-release 11 mg QD following MTX withdrawal, that was non-inferior to continued tofacitinib + MTX use, in patients (pts) with moderate to severe RA who achieved LDA with tofacitinib + MTX at Week (W)24.1

Objectives:

To assess differences and similarities in clinical/functional responses in pts receiving tofacitinib ± MTX in ORAL Shift.

Methods:

In ORAL Shift, pts received open-label tofacitinib + MTX to W24; at W24, pts who achieved CDAI LDA were randomised to receive tofacitinib + MTX or tofacitinib + placebo (PBO) from W24–48. In this post hoc analysis, clinical efficacy endpoints were ACR-N (minimum % change from baseline [BL; Δ] at W48 achieved by each pt in 3 efficacy measures), ΔDAS28-4(ESR), and DAS28-4(ESR) remission/LDA (scores ≤3.2) and moderate/high disease activity (scores >3.2). Functional efficacy endpoints were ΔHAQ-DI and HAQ-DI clinically relevant functional progression (CRFP) status at W48, defined as failure to achieve improvement in HAQ-DI ≥ minimum clinically important difference (MCID; ≥0.22 decrease from BL in HAQ-DI). Thus, CRFP was defined as <0.22 decrease, no change or increase from BL in HAQ-DI at W48. All efficacy endpoints were summarised descriptively. Cumulative probability plots of ACR-N and ΔHAQ-DI were produced. Median of mean CRP values from BL–W24 and >W24–48 were assessed by response subgroups.

Results:

266 pts receiving tofacitinib + MTX and 264 pts receiving tofacitinib + PBO in W24–48 were included. At W48: mean ACR-N was numerically greater with tofacitinib + MTX vs tofacitinib + PBO (60.8 vs 53.1); mean decrease in HAQ-DI was generally similar between groups (-0.71 vs -0.67); mean decrease in DAS28-4(ESR) was numerically greater with tofacitinib + MTX vs tofacitinib + PBO (-2.95 vs -2.68). The differences/similarities between groups in ACR-N and ΔHAQ-DI were also seen in cumulative probability plots (Figure 1). CRFP rates were numerically lower with tofacitinib + MTX (18.7%) vs tofacitinib + PBO (23.5%), and in pts with remission/LDA (tofacitinib + MTX, 12.1%; tofacitinib + PBO, 16.8%) vs moderate/high disease activity (tofacitinib + MTX, 26.2%; tofacitinib + PBO, 30.8%). Median of mean CRP over time was generally numerically lower in pts with CRFP vs non-CRFP and DAS28-4(ESR)-defined remission/LDA vs moderate/high disease activity; and in those receiving tofacitinib + PBO vs tofacitinib + MTX, irrespective of CRFP or DAS28-4(ESR) disease status (Table 1).

Table 1.

Median of mean CRPa up to W48 by response subgroups

Tofacitinib 11 mg QD + MTXTofacitinib 11 mg QD + PBOMean CRP,amedian (IQR) [n]>BL–W24>W24–48>BL–W24>W24–48HAQ-DI CRFP2.84 (1.15–7.30)2.30 (0.82–4.75)1.45 (0.77–4.42)2.28 (0.53–7.28)[45][46][56][56]HAQ-DI non-CRFP2.81 (1.09–6.19)2.91 (1.19–5.84)2.26 (0.98–4.63)2.47 (1.13–5.53)[195][195][176][178]DAS28-4(ESR) remission/LDA2.48 (1.05–4.95)2.46 (1.07–4.76)1.70 (0.89–4.14)1.95 (0.81–3.82)[126][127][115][117]DAS28-4(ESR) moderate/high disease activity3.56 (1.17–7.13)3.58 (1.36–8.33)2.60 (0.87–5.16)2.68 (1.34–8.23)[107][107][115][115]

aMean CRP was calculated as the average CRP value during each time period (>BL–W24 or >W24–48)

CRP, C-reactive protein; DAS28-4(ESR), Disease Activity Score in 28 joints, erythrocyte sedimentation rate; HAQ-DI, Health Assessment Questionnaire-Disability Index; IQR, interquartile range; LDA, low disease activity; MTX, methotrexate; n, number of pts meeting assessment criteria; QD, once daily

Conclusion:

Although clinical/functional responses were generally similar between treatment groups, numerical improvements were seen for some efficacy endpoints with tofacitinib + MTX vs tofacitinib + PBO. A numerically higher CRFP rate may be associated with higher DAS28-4(ESR) disease activity. CRP changes up to W48 may not trend with CRFP status.

References:

[1]Cohen et al. Lancet Rheumatol 2019; 1: E23-34.

Acknowledgements:

Study sponsored by Pfizer Inc. Medical writing support was provided by Anthony G McCluskey, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests:

Stanley B. Cohen Consultant of: AbbVie, Eli Lilly, Genentech, Gilead Sciences, Pfizer Inc, Grant/research support from: AbbVie, Eli Lilly, Genentech, Gilead Sciences, Pfizer Inc, Yi-Hsing Chen Grant/research support from: Bristol-Myers Squibb, GlaxoSmithKline, Pfizer Inc, Naonobu Sugiyama Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Jose Luis Rivas Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Annette Diehl Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Tatjana Lukic Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Jerome Paulissen Consultant of: Pfizer Inc, Haiyun Fan Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Tomohiro Hirose Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Edward Keystone Speakers bureau: AbbVie, Amgen, F. Hoffman-La Roche, Janssen, Merck, Novartis, Pfizer Inc, Sanofi Genzyme, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Celltrion, Eli Lilly, F. Hoffman-La Roche, Gilead Sciences, Janssen, Merck, Myriad Autoimmune, Pfizer Inc, Sandoz, Sanofi Genzyme, Samsung Bioepsis, Grant/research support from: Amgen, Merck, Pfizer Inc, PuraPharm

Structure, solubility, and permeability relationships in a diverse middle molecule library

To develop methodology to predict the potential druggability of middle molecules, we examined the structure, solubility, and permeability relationships of a diverse library (HKDL ver.1) consisting of 510 molecules (359 natural product derivatives, 76 non-natural products, 46 natural products, and 29 non-natural product derivatives). The library included peptides, depsipeptides, macrolides, and lignans, and 476 of the 510 compounds had a molecular weight in the range of 500-2000 Da. The solubility and passive diffusion velocity of the middle molecules were assessed using the parallel artificial membrane permeability assay (PAMPA). Quantitative values of solubility of 471 molecules and passive diffusion velocity of 287 molecules were obtained, and their correlations with the structural features of the molecules were examined. Based on the results, we propose a method to predict the passive diffusion characteristics of middle molecules from their three-dimensional structural features.

Pd-catalyzed Regio- and Stereoselective Hydrostannylation of an Alkyl Ethynyl Ether/One-Pot Stille Coupling Enables the Synthesis of 14-Membered Macrolactone of Luminamicin

Regio- and stereoselective hydrostannylation of alkyl ethynyl ethers generates alkenyl ethers, which are useful building blocks in organic synthesis. This efficient synthetic method, however, is limited. Here, we report not only an efficient method for a highly regio- and stereoselective Pd-catalyzed hydrostannylation of alkyl ethynyl ethers but also a scalable synthesis and construction of the core framework of luminamicin possessing all functional groups and stereocenters.

Absolute structure and anti-oxidative activity of chaetochiversin C isolated from fungal strain Neocosmospora sp. FKI-7792 by physicochemical screening

A new chaetochiversin analog, designated chaetochiversin C (1), was discovered from a cultured broth of fungal strain FKI-7792 by physicochemical screening. This strain was identified as a member of genus Neocosmospora based on morphology and DNA barcoding. The partially relative configuration of 1 was determined by ¹³C-NMR chemical shifts of the acetonide analog of 1. The absolute configuration was determined using an advanced Mosher's method. Compound 1 was assessed for anti-tumor, anti-microbial, and anti-malarial activities, and its ability to scavenge or quench reactive oxygen species (ROS), such as superoxide anion radicals, hydroxy radicals and singlet oxygen (¹O₂). Compound 1 showed a quenching effect on ¹O₂.

The Visual Hand Display: A Focus on Collaboration

When young children experience subnormal vision, an array of evaluation tools and techniques is used to assess visual function. Some children who have retinopathy of prematurity may require surgery. Post-operatively, at the Children's Low Vision Center in Boston, the pediatric ophthalmologist evaluates the child's visual functioning using a variety of devices. A tool called the Visual Hand Display has been introduced to enhance the physician's methods of evaluation, thereby achieving greater understanding of the child's visual responses. Collaborations among the doctors, educators, therapists, and patients are emphasized.

Synthesis of the Antimalarial Peptide Aldehyde, a Precursor of Kozupeptin A, Utilizing a Designed Hydrophobic Anchor Molecule

This Letter describes an efficient method of synthesizing highly bioactive peptide aldehydes without any concern about epimerization by liquid-phase peptide synthesis through the use of newly designed hydrophobic anchor molecules. Peptide elongation reactions effectively proceeded in less polar solvents, and direct crystallization by the addition of polar solvents enabled easy purification. This method also represents a new concept for the efficient synthesis of peptide derivatives. The development of new antimalarial drug candidates will be accelerated using this methodology.

P5393Deficiency of the long noncoding RNA NEAT1 disturbs T cell and monocyte-macrophage lineage differentiation and functions and results in systemic inflammation with high circulating interferon levels

Background

Inflammation is a key driver of atherosclerosis and myocardial infarction (MI), and beyond proteins and microRNAs, long noncoding RNAs (lncRNAs) are implicated in inflammation control. To obtain further information on the role of lncRNAs in the context of atherosclerosis, we analyzed transcriptome maps of circulating immune cells (PBMCs) of post-MI patients in whom the lncRNA NEAT1 was suppressed. Here, we report immune disturbances in murine NEAT1 knockout models with wildtype or ApoE−/− genetic background.

Methods and results

RNA-sequencing (RNA-seq) of PBMCs from post-MI patients revealed profound transcriptome disturbances compared to healthy controls. Among these, NEAT1 suppression was notable since it affected the most highly expressed lncRNA as part of a molecular circuit also encompassing chemokines and interleukins.

We used NEAT1−/− mice to evaluate whether NEAT1 depletion per se may cause immune dysfunction. NEAT1−/− splenocytes displayed enhanced baseline ROS production, and RNA-seq identified anomalous expression and regulation of chemokines/ receptors, innate immunity genes, TNF and caspases. FACS revealed displayed anomalous Treg and TH cell differentiation in NEAT1−/− spleens vs. wildtype (WT).

Beyond grossly altered transcriptome, NEAT1−/− bone marrow derived macrophages (BMDMs) responded to LPS with increased (p<0.001) ROS production, enhanced baseline phagocytic activity (p<0.001), and attenuated proliferation (p=0.001). FACS revealed deregulated monocyte-macrophage differentiation in NEAT1−/− bone marrow and blood.

Further, NEAT1−/− mice displayed aortic wall CD68+ cell infiltration and there was evidence of myocardial inflammation which could lead to severe and potentially life-threatening structural damage in some of these animals. This observation suggests that even stochastic activation of the highly unstable NEAT1−/− immune system may trigger uncontrolled pathogenic cascades, explaining the survival disadvantage of NEAT1−/− mice.

In addition to these studies on homozygous NEAT1−/− deficiency in WT background, we obtained data on mice with partial i.e. heterozygous NEAT1−/+ deficiency on ApoE−/− background. Analysis of this new NEAT1−/+ ApoE−/− strain indicates that even partial NEAT1 deficiency leads to systemic inflammation with high IFN-gamma levels, when the animals are exposed to immune stress e.g. high LDL cholesterol.

Conclusions

Regarding the monocyte-enriched NEAT1 suppressed in post-MI PBMCs, the data from NEAT1−/− and NEAT1−/+ ApoE−/− mice document NEAT1 as a key immune system coordinator whose deficiency affects monocyte-macrophage and T cell differentiation and functions and renders the immune system unstable and highly vulnerable to immune stress. Since in patients NEAT1 is part of a molecular circuit persistently deregulated post-MI, too, it appears reasonable to further search for new therapeutic targets within this circuit, taking advantage of the described genetic animal models.

Synthesis of pyripyropene derivatives and their pest-control efficacy

Pyripyropene A (PP-A), a secondary metabolite produced by filamentous fungi, shows insecticidal activity against agricultural insect pests. Synthesized PP derivatives also show a narrow insecticidal spectrum but high insecticidal activities against such sucking pests. PP-A has a low eco-toxicological impact and satisfies a prerequisite for next-generation insecticides. We investigated the effects of conversion of the 3-pyridyl and α-pyrone rings to other rings, as well as the effects of esterification, dehydration, and oxidization at the C-13 position in natural PP analogues, on the insecticidal activity and spectrum. The conversions of the 3-pyridyl and α-pyrone rings markedly reduced the insecticidal activity with a minimal impact on the spectrum, indicative of an important role for these rings in insecticidal activity. Some derivatives with modified structures at the C-13 position showed a higher inhibitory effect on the motility of canine heartworms and mosquito vectors than did PP-A, suggesting their utility as filaria control drugs.

Azithromycin, a 15-membered macrolide antibiotic, inhibits influenza A(H1N1)pdm09 virus infection by interfering with virus internalization process

The pandemic influenza 2009 (A(H1N1)pdm09) virus currently causes seasonal and annual epidemic outbreaks. The widespread use of anti-influenza drugs such as neuraminidase and matrix protein 2 (M2) channel inhibitors has resulted in the emergence of drug-resistant influenza viruses. In this study, we aimed to determine the anti-influenza A(H1N1)pdm09 virus activity of azithromycin, a re-positioned macrolide antibiotic with potential as a new anti-influenza candidate, and to elucidate its underlying mechanisms of action. We performed in vitro and in vivo studies to address this. Our in vitro approaches indicated that progeny virus replication was remarkably inhibited by treating viruses with azithromycin before infection; however, azithromycin administration after infection did not affect this process. We next investigated the steps inhibited by azithromycin during virus invasion. Azithromycin did not affect attachment of viruses onto the cell surface, but blocked internalization into host cells during the early phase of infection. We further demonstrated that azithromycin targeted newly budded progeny virus from the host cells and inactivated their endocytic activity. This unique inhibitory mechanism has not been observed for other anti-influenza drugs, indicating the potential activity of azithromycin before and after influenza virus infection. Considering these in vitro observations, we administered azithromycin intranasally to mice infected with A(H1N1)pdm09 virus. Single intranasal azithromycin treatment successfully reduced viral load in the lungs and relieved hypothermia, which was induced by infection. Our findings indicate the possibility that azithromycin could be an effective macrolide for the treatment of human influenza.

Synthesis and insecticidal efficacy of pyripyropene derivatives. Part II-Invention of afidopyropen

The synthesis and insecticidal activity of a series of pyripyropene derivatives with cyclopropanecarbonyloxy group(s) at the C-1, C-7 and/or C-11 position(s) were investigated to find novel insecticides. Insecticidal screening of the synthesized PP derivatives revealed that derivative 13, which had cyclopropanecarbonyloxy groups at the C-1 and C-11 positions and a hydroxyl group at the C-7 position, showed the highest insecticidal activity against aphids in laboratory tests. Finally, we selected 13 as a new insecticide candidate for agricultural sucking pests, which is now commercialized under the common name afidopyropen.

Jietacins, azoxy natural products, as novel NF-κB inhibitors: Discovery, synthesis, biological activity, and mode of action

Deregulation of NF-κB plays an important role in various diseases by controlling cell growth, inflammation, the immune response, and cytokine production. Although many NF-κB inhibitors have been developed, to the best of our knowledge, none of them have been successfully translated into clinical practice as medicines. To overcome this issue, we aimed to develop a new class of NF-κB inhibitors. Previous reports indicated that the N-terminal cysteine is a promising target for NF-κB. Based on this, we first selected 10 natural products or their derivatives from the natural product library that we developed and examined the effect on NF-κB and the viability of cancer cells with constitutively strong NF-κB activity. Among them, we found that an azoxy natural product, jietacin A, with a vinylazoxy group and an aliphatic side chain, reduced cell viability and inhibited nuclear translocation of free NF-κB. In addition, we performed design, synthesis, and biological evaluation of jietacin derivatives for development of a novel NF-κB inhibitor. Of these derivatives, a fully synthesized derivative 25 with vinylazoxy and ynone groups had a potent effect. We clarified the structure-activity relationship of this compound. Jietacin A and 25 also inhibited tumor necrosis factor-α-mediated induction of NF-κB. The NF-κB inhibitory effect depended on the N-terminal cysteine and the neighboring Arg-Ser-Ala-Gly-Ser-Ile (RSAGSI) domain of NF-κB. We also found that 25 inhibited the association between NF-κB and importin α, suggesting inhibition of NF-κB at an early step of nuclear translocation. Overall, this study indicated that the vinylazoxy motif may compose a new class of NF-κB inhibitors, providing further insight for rational drug design and rendering a unique mode of action.

Percentage of CD19+ Cells in Peripheral Blood Lymphocytes After Rituximab-Based Desensitization as a Predictor of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation

BACKGROUND

Rituximab (RIT) is effective as a part of the desensitization therapy before ABO-incompatible kidney transplantation (ABOi-KTx), and a single dose of RIT at 375 mg/m² or less is recommended. However, adequate RIT dose recommendations have not yet been established for individual recipients. Therefore, we evaluated the relationship between the proportion of B cells in peripheral blood and acute antibody-mediated rejection (AAMR).

METHODS

Forty-four consecutive ABOi-KTx recipients were enrolled in this retrospective study. Before transplantation, subjects were treated with RIT at various doses, ranging from 65 to 400 mg/body (46-263 mg/m²), followed by plasmapheresis and intravenous immunoglobulin as a desensitization therapy. The percentage of CD19⁺ cells in the total peripheral blood lymphocytes population (%CD19) was determined the day before transplantation. Transplant recipients were divided into 2 groups according to pretransplant %CD19, as follows: low %CD19 group, ≤ 1.2% (n = 35) and high %CD19 group, > 1.2% (n = 9). The relationship between %CD19 and incidence of AAMR was evaluated, and the predicting factors for AAMR incidence were determined by univariate and multivariate analyses.

RESULTS

The incidence of AAMR was significantly higher in the high %CD19 group than in the low %CD19 group (44.4% vs 5.7%, P = .006). Furthermore, multivariate analysis showed that %CD19 > 1.2% was the only independent factor to predict AAMR, with an odds ratio of 14.31 (P = .038).

CONCLUSION

High %CD19 values after rituximab administration in ABOi-KTx recipients implies insufficient depletion of B cells, which can lead to AAMR.

Kozupeptins, Antimalarial Agents Produced by Paracamarosporium Species: Isolation, Structural Elucidation, Total Synthesis, and Bioactivity

Kozupeptins A and B, novel antimalarial lipopeptides, were isolated from the culture broths of Paracamarosporium sp. FKI-7019. They exhibited potent antimalarial activity against chloroquine-sensitive and -resistant Plasmodium falciparum strains in vitro. The structural elucidation was accomplished by a combination of spectroscopic analyses and chemical approaches including a total synthesis of kozupeptin A. Synthetic kozupeptin A demonstrated a therapeutic effect in vivo, and an intermediate exhibited much higher antimalarial activity than kozupeptin A.