Synthesis and properties of a novel modified nucleic acid, 2'-N-methanesulfonyl-2'-amino-locked nucleic acid.

2'-Amino-locked nucleic acid has a functionalizable nitrogen atom at the 2'-position of its furanose ring that can provide desired properties to a nucleic acid as a scaffold. In this study, we synthesized a novel nucleic acid, 2'-N-methanesulfonyl-2'-amino-locked nucleic acid (ALNA[Ms]) and conducted comparative studies on the physical and pharmacological properties of the ALNA[Ms] and on conventional nucleic acids, such as 2'-methylamino-LNA (ALNA[Me]), which is a classical 2'-amino-LNA derivative, and also on 2',4'-BNA/LNA (LNA). ALNA[Ms] oligomers exhibited binding affinities for the complementary RNA strand that are similar to those of conventional nucleic acids. Four types of ALNA[Ms] nucleosides exhibited no genotoxicity in bacterial reverse mutation assays. The knockdown abilities of Malat1 RNA using the Matat1 antisense oligonucleotide (ASO) containing ALNA[Ms] were higher than those of ALNA[Me] and were closer to those of LNA. Furthermore, the ASO containing ALNA[Ms] showed different tissue tropism from that containing LNA. ALNA[Ms] exhibited biological activities that were distinct from conventional constrained nucleic acids, suggesting the possibility that ALNA[Ms] can serve as novel modified nucleic acids in oligonucleotide therapeutics.

Altered Biodistribution and Hepatic Safety Profile of a Gapmer Antisense Oligonucleotide Bearing Guanidine-Bridged Nucleic Acids.

Guanidine-bridged nucleic acid (GuNA) is a novel 2',4'-bridged nucleic acid/locked nucleic acid (2',4'-BNA/LNA) analog containing cations that exhibit strong affinity for target RNA and superior nuclease resistance. In this study, Malat1 antisense oligonucleotide (ASO) bearing GuNA was evaluated for target knockdown (KD) activity and tolerability. The GuNA ASO did not interfere with RNase H recruitment on the target RNA/ASO heteroduplex and did show potent target KD activity in a skeletal muscle-derived cell line equivalent to that of the LNA ASO under gymnotic conditions, whereas almost no KD activity was observed in a hepatocyte-derived cell line. The GuNA ASO exhibited potent KD activity in various tissues; the KD activity in the skeletal muscle was equivalent with that of the LNA ASO, but the KD activities in the liver and kidney were clearly lower compared with the LNA ASO. In addition, despite the higher accumulation of the GuNA ASO in the liver, levels of aspartate aminotransferase and alanine aminotransferase with the GuNA ASO administration were not elevated compared with those induced by the LNA ASO. Our data indicate that the GuNA ASO is tolerable and exhibits unique altered pharmacological activities in comparison with the LNA ASO in terms of the relative effect between liver and skeletal muscle.

Patient Preference for Treatment Mode of Biologics in Rheumatoid Arthritis: A 2020 Web-based Survey in Japan.

INTRODUCTION: Although the proportion of patients with rheumatoid arthritis (RA) using biologic disease-modifying antirheumatic drugs (bDMARDs) has increased steadily, the relationship between patient background and preference for bDMARDs has not been fully investigated. METHODS: We conducted a web-based questionnaire survey among patients aged ≥ 20 years with RA receiving bDMARDs. Participants were recruited through an internet research company in Japan. Study endpoints included factors affecting the preferred bDMARD treatment mode, namely, in-hospital intravenous infusion (infusion), in-hospital subcutaneous injection (in-hospital injection), or self-administered subcutaneous injection (self-injection), and discrepancies between the current and preferred treatment mode. RESULTS: Of the 400 patients surveyed for preferred treatment mode, 15.3% preferred infusion, 18.0% preferred in-hospital injection, and 66.8% preferred self-injection. A preference for infusion (odds ratio [OR] 2.218 and 6.165) and in-hospital injection (OR 4.735 and 6.026) versus self-injection was significantly associated with higher current frequency of hospital visits and anxiety or other hurdles related to self-injection. A flexible administration setting was significantly associated with a preference for self-injection versus infusion (OR 0.401) and versus in-hospital injection (OR 0.445). Further, age (< 40 vs. ≥ 60 years) was significantly associated with a preference for self-injection versus in-hospital injection (OR 0.120). Many patients reported no discrepancy between their current and preferred treatment mode (patients receiving infusion, 68.0%; in-hospital injection, 71.2%; and self-injection, 94.0%). However, > 90% of patients responded that they would change their current mode in the future following a recommendation by a medical professional, aging, or a change in RA symptoms. CONCLUSIONS: This web-based survey showed that patient preference for bDMARD treatment mode was significantly associated with age, frequency of hospital visits, flexible administration setting, and anxiety or other hurdles to self-injection. Changes in patient background which affect the preferred treatment mode should be considered in decision-making for RA therapy with bDMARDs. TRIAL REGISTRATION: R000048089 (UMIN-CTR).

Dose Adjustment of Methotrexate Administered Concomitantly with Golimumab for Rheumatoid Arthritis in Japanese Real-World Clinical Settings.

INTRODUCTION: The combination of methotrexate (MTX) with biological disease-modifying antirheumatic drugs (bDMARDs) is a recommended treatment option for rheumatoid arthritis (RA) patients showing an inadequate response to MTX monotherapy. However, the adequate dose of MTX, especially in long-term treatment with bDMARDs/MTX combination therapy, remains under-addressed. Since RA patients require long-term treatment, we examined the effects of using golimumab (GLM) in the long run as well as its persistency and associated factors. METHODS: We used the Japan Medical Data Center Inc. (JMDC) administrative claims data of 489 patients receiving GLM therapy for calculating the persistency in patients with constant, reduced, or escalated MTX dosing. The factors associated with GLM persistency were assessed using Cox proportional hazard modeling, controlling for the dose adjustment of concomitant MTX, age, sex, RA disease period, and the initial dose of GLM or concomitant MTX during GLM/MTX combination therapy. RESULTS: During GLM/MTX combination therapy, up to 52% of patients were reported to experience dose adjustments of concomitant MTX treatment (i.e., dose reduction and escalation in 34% and 18% of patients, respectively). Persistency was similar in the MTX dose-reduction patients and the MTX dose-constant patients. In the Cox proportional hazard model, no significant differences were observed in association with GLM persistency, including with respect to MTX dose adjustment. CONCLUSIONS: GLM prescription was continued in 80% or more (1 year) and 50% or more (3 years) of RA patients receiving reduced concomitant MTX dosing, suggesting that MTX dose adjustment (including MTX reduction) could be considered in GLM/MTX combination therapy.

Analysis of origin recognition complex in saccharomyces cerevisiae by use of Degron mutants.

Origin recognition complex (ORC), a six-protein complex (Orc1p-Orc6p), may deeply involve in initiation of chromosomal DNA replication. However, since most temperature-sensitive orc mutants of Saccharomyces cerevisiae show the accumulation of cells with nearly 2C DNA content, the exact stage at which ORC acts is not fully understood. In this study, we constructed a heat-inducible degron mutant for each ORC subunit. As well as each targeted subunit, other subunits of ORC were also rapidly degraded under non-permissive conditions. In the orc5 degron mutant, incubation under the non-permissive conditions caused accumulation of cells with nearly 2C DNA content, and phosphorylation of Rad53p. When Orc5p (ORC) is depleted, this inhibits G1/S transition and formation of a pre-replicative complex (pre-RC). For pre-RC to form, and G1/S transition to proceed, Orc5p (ORC) must be present in late G1, rather than early G1, or G2/M. Block and release experiments revealed that Orc5p (ORC) is not necessary for S and G2/M phase progression. We therefore propose that ORC is necessary for the G1/S transition and pre-RC formation, and accumulation of cells with nearly 2C DNA content seen in various orc mutants is due to inefficient pre-RC formation, and/or induction of checkpoint systems.

Mechanism for the degradation of origin recognition complex containing Orc5p with a defective Walker A motif and its suppression by over-production of Orc4p in yeast cells.

Orc5p is one of six subunits constituting the ORC (origin recognition complex), a possible initiator of chromosomal DNA replication in eukaryotes. Orc5p contains a Walker A motif. We recently reported that a strain of Saccharomyces cerevisiae having a mutation in Orc5p's Walker A motif (orc5-A), showed cell-cycle arrest at G2/M and degradation of ORC at high temperatures (37 degrees C). Over-production of Orc4p, another subunit of ORC, specifically suppressed these phenotypes [Takahashi, Yamaguchi, Yamairi, Makise, Takenaka, Tsuchiya and Mizushima (2004) J. Biol. Chem. 279, 8469-8477]. In the present study, we examined the mechanisms of ORC degradation and of its suppression by Orc4p over-production. In orc5-A, at high temperatures, ORC is degraded by proteasomes; either addition of a proteasome inhibitor, or introduction of a mutation of either tan1-1 or nob1-4 that inhibits proteasomes, prevented ORC degradation. Introduction of the tan1-1 mutation restored cell cycle progression, suggesting that the defect was due to ORC degradation by proteasomes. Yeast two-hybrid and co-immunoprecipitation analyses suggested that Orc5p interacts preferentially with Orc4p and that the orc5-A mutation diminishes this interaction. We suggest that this interaction is mediated by the C-terminal region of Orc4p, and the N-terminal region of Orc5p. Based on these observations, we consider that ATP binding to Orc5p is required for efficient interaction with Orc4p and that, in orc5-A, loss of this interaction at higher temperatures allows proteasomes to degrade ORC, causing growth defects. This model could also explain why over-production of Orc4p suppresses the orc5-A strain's phenotype.

Effects of aging and uninephrectomy on renal changes in Tsukuba hypertensive mice.

Renal dysfunction is accelerated by various factors such as hypertension, aging and diabetes. Glomerular hyper-filtration, considered one of the major risk factors leading to diabetic nephropathy, is often encountered in diabetic patients. However, the interrelationship of these risk factors during the course and development of renal dysfunction has not been fully elucidated. In this study, the effects of aging and uninephrectomy (UNx)-induced hyperfiltration on renal changes were investigated in Tsukuba hypertensive mice (THM) carrying both human renin and angiotensinogen genes. In THM, the urinary albumin/creatinine (Alb/Cr) ratio was elevated with age without a concomitant increase in the plasma Cr concentration. Moreover, the urinary neutrophil gelatinase-associated lipocalin/Cr (NGAL/Cr) ratio, the renal monocyte chemoattractant protein-1 (MCP-1) mRNA expression and the renal collagen type I α 2 (COL1A2) mRNA expression were also increased with age. Age-related albuminuria in THM is likely caused by renal tubular damage, enhanced inflammatory response and tubulointerstitial fibrosis. Furthermore, following UNx, the urinary Alb/Cr ratio and the plasma Cr concentration were increased in THM. The urinary NGAL/Cr ratio and the renal MCP-1 and COL1A2 mRNA expression were not affected by UNx. These results suggested that UNx-induced albuminuria in THM was caused by glomerular dysfunction, rather than renal tubular injury. In conclusion, this study demonstrated for the first time the effects of aging and UNx on renal changes in THM. These findings strongly reinforce the significance of applying a diversity of therapeutic approaches to the management of renal dysfunction.

Expression of vascular endothelial growth factor (VEGF) associated with histopathological changes in rodent models of osteoarthritis.

Vascular endothelial growth factor (VEGF) and its receptors have recently reported to be expressed in human osteoarthritis (OA), suggesting that VEGF could be implicated in the pathogenesis of this disease. In the present study, expression of VEGF in the articular cartilage was determined in three different OA models: medial meniscectomy and monoiodoacetate (MIA) injection in rats and age-associated spontaneous joint cartilage destruction in guinea pigs. VEGF was detected by immunohistochemical analysis in the regenerative and hypertrophic chondrocytes, perichondrium and osteophyte areas and chondrocyte clones. Stain intensity of VEGF immunoreactivity increased simultaneously with the degree of cartilage destruction and reparation. These results suggest that VEGF is a key factor in the articular cartilage in human OA and animal OA models.

Analysis on origin recognition complex containing Orc5p with defective Walker A motif.

Orc5p is one of six proteins that make up the origin recognition complex (ORC), a candidate initiator of chromosomal DNA replication in eukaryotes. To investigate the role of ATP binding to Orc5p in cells, we constructed orc5-A, a strain of Saccharomyces cerevisiae having a mutation in the Walker A motif of Orc5p (K43E). The strain showed temperature-sensitive growth. Incubation at a nonpermissive temperature (37 degrees C) caused accumulation of cells with nearly 2C DNA content. Overproduction of Orc4p, another subunit of ORC, suppresses this temperature sensitivity, but overproduction of other subunits did not. Overproduction of Orc4p did not suppress the temperature sensitivity of another orc5 mutant, orc5-1, whose mutation, L331P, is outside the ATP-binding motif. These results suggest that Orc4p is specifically involved in ATP binding to Orc5p itself or its function in DNA replication. Immunoblotting experiments revealed that in the orc5-A strain at a nonpermissive temperature, all ORC subunits gradually disappeared, suggesting that ORC5-A becomes degraded at nonpermissive temperatures. We therefore consider that ATP binding to Orc5p is involved in efficient ORC formation and that Orc4p is involved in this process.