Kenji Maeda

Prof. Dr. Kenji Maeda

orcid

Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2003 in Antimicrobial Agents and Chemotherapy
Verified
Journal Article
Open access
PDF file
YKYasuhiro Koh
Yasuhiro Koh
HNHirotomo Nakata
Hirotomo Nakata
KMKenji Maeda
Kenji Maeda
HOHiromi Ogata
Hiromi Ogata
GBGeoffrey Bilcer
Geoffrey Bilcer
HMHiroaki Mitsuya
Hiroaki Mitsuya
We designed, synthesized, and identified UIC-94017 (TMC114), a novel nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) containing a 3( R ),3a( S ),6a( R )- bis -tetrahydrofuranylurethane ( bis -THF) and a sulfonamide isostere which is extremely potent against laboratory HIV-1 strains and primary clinical isolates (50% inhibitory concentration [IC 50 ], ∼0.003 μM; IC 90 , ∼0.009 μM) with minimal cytotoxicity (50% cytotoxic concentration for CD4 + MT-2 cells, 74 μM). UIC-94017 blocked the infectivity and replication of each of HIV-1 NL4-3 variants exposed to and selected for resistance to saquinavir, indinavir, nelfinavir, or ritonavir at concentrations up to 5 μM (IC 50 s, 0.003 to 0.029 μM), although it was less active against HIV-1 NL4-3 variants selected for resistance to amprenavir (IC 50 , 0.22 μM). UIC-94017 was also potent against multi-PI-resistant clinical HIV-1 variants isolated from patients who had no response to existing antiviral regimens after having received a variety of antiviral agents. Structural analyses revealed that the close contact of UIC-94017 with the main chains of the protease active-site amino acids (Asp-29 and Asp-30) is important for its potency and wide spectrum of activity against multi-PI-resistant HIV-1 variants. Considering the favorable pharmacokinetics of UIC-94017 when administered with ritonavir, the present data warrant that UIC-94017 be further developed as a potential therapeutic agent for the treatment of primary and multi-PI-resistant HIV-1 infections.

16 May 2022 in Nature
Verified
Journal Article
Closed access
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RURyuta Uraki
Ryuta Uraki
MKMaki Kiso
Maki Kiso
SIShun Iida
Shun Iida
MIMasaki Imai
Masaki Imai
ETEmi Takashita
Emi Takashita
YKYoshihiro Kawaoka
Yoshihiro Kawaoka
1

10 December 2020 in Viruses
Verified
Journal Article
Open access
PDF file
Seiya YamayoshiSeiya Yamayoshi
Seiya Yamayoshi
YSYUKO SAKAI-TAGAWA
YUKO SAKAI-TAGAWA
MKMichiko Koga
Michiko Koga
OAOsamu Akasaka
Osamu Akasaka
INIchiro Nakachi
Ichiro Nakachi
YKYoshihiro Kawaoka
Yoshihiro Kawaoka
Reverse transcription-quantitative PCR (RT-qPCR)-based tests are widely used to diagnose coronavirus disease 2019 (COVID-19). As a result that these tests cannot be done in local clinics where RT-qPCR testing capability is lacking, rapid antigen tests (RATs) for COVID-19 based on lateral flow immunoassays are used for rapid diagnosis. However, their sensitivity compared with each other and with RT-qPCR and infectious virus isolation has not been examined. Here, we compared the sensitivity among four RATs by using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolates and several types of COVID-19 patient specimens and compared their sensitivity with that of RT-qPCR and infectious virus isolation. Although the RATs read the samples containing large amounts of virus as positive, even the most sensitive RAT read the samples containing small amounts of virus as negative. Moreover, all RATs tested failed to detect viral antigens in several specimens from which the virus was isolated. The current RATs will likely miss some COVID-19 patients who are shedding infectious SARS-CoV-2.

15 August 2004 in Journal of Virology
Verified
Journal Article
Open access
PDF file
KMKenji Maeda
Kenji Maeda
HNHirotomo Nakata
Hirotomo Nakata
YKYasuhiro Koh
Yasuhiro Koh
TMToshikazu Miyakawa
Toshikazu Miyakawa
HOHiromi Ogata
Hiromi Ogata
HMHiroaki Mitsuya
Hiroaki Mitsuya
We identified a novel spirodiketopiperazine (SDP) derivative, AK602/ONO4128/GW873140, which specifically blocked the binding of macrophage inflammatory protein 1α (MIP-1α) to CCR5 with a high affinity ( K d of ≈3 nM), potently blocked human immunodeficiency virus type 1 (HIV-1) gp120/CCR5 binding and exerted potent activity against a wide spectrum of laboratory and primary R5 HIV-1 isolates, including multidrug-resistant HIV-1 (HIV-1 MDR ) (50% inhibitory concentration values of 0.1 to 0.6 nM) in vitro. AK602 competitively blocked the binding to CCR5 expressed on Chinese hamster ovary cells of two monoclonal antibodies, 45523, directed against multidomain epitopes of CCR5, and 45531, specific against the C-terminal half of the second extracellular loop (ECL2B) of CCR5. AK602, despite its much greater anti-HIV-1 activity than other previously published CCR5 inhibitors, including TAK-779 and SCH-C, preserved RANTES (regulated on activation normal T-cell expressed and secreted) and MIP-1β binding to CCR5 + cells and their functions, including CC-chemokine-induced chemotaxis and CCR5 internalization, while TAK-779 and SCH-C fully blocked the CC-chemokine/CCR5 interactions. Pharmacokinetic studies revealed favorable oral bioavailability in rodents. These data warrant further development of AK602 as a potential therapeutic for HIV-1 infection.

1 June 2008 in Clinical Cancer Research
Verified
Journal Article
Open access
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AHAkinobu Hamada
Akinobu Hamada
TSTristan Sissung
Tristan Sissung
DPDouglas K. Price
Douglas K. Price
RDRomano Danesi
Romano Danesi
CCCindy H. Chau
Cindy H. Chau
William FiggWilliam Figg
William Figg
Purpose: The organic anion transporter OATP1B3, encoded by SLCO1B3, is involved in the transport of steroid hormones. However, its role in testosterone uptake and clinical outcome of prostatic cancer is unknown. This study examined (a) the SLCO1B3 genotype in cancer cells as well as the uptake of testosterone by cells transfected with genetic variants of SLCO1B3; (b) the expression of OATP1B3 in normal prostate, benign prostatic hyperplasia, and prostatic cancer; and (c) the role of SLCO1B3 haplotype on clinical outcome of Caucasian patients with androgen-independent prostatic cancer. Experimental Design: SLCO1B3 genotype was assessed in the NCI-60 panel of tumor cells by sequencing, whereas testosterone transport was analyzed in Cos-7 cells transfected with WT, 334G, and 699A SLCO1B3 variants. OATP1B3 expression in prostatic tissues was examined by fluorescence microscopy, and the relationship between SLCO1B3 haplotypes and survival was examined in patients. Results: Cells transfected with wild-type (334T/699G) SLCO1B3, or with a vector containing either the 334G or 699A variants, actively transported testosterone, whereas its uptake was impaired in cells transfected with a gene carrying both 334G and 699A single nucleotide polymorphisms. Prostatic cancer overexpresses OATP1B3 compared with normal or benign hyperplastic tissue; patients with SLCO1B3 334GG/699AA haplotype showed longer median survival (8.5 versus 6.4 years; P = 0.020) and improved survival probability at 10 years (42% versus 23%; P < 0.023) than patients carrying TT/AA and TG/GA haplotypes. Conclusions: The common SLCO1B3 GG/AA haplotype is associated with impaired testosterone transport and improved survival in patients with prostatic cancer.

1 May 2006 in Journal of Biological Chemistry
Verified
Journal Article
Open access
PDF file
KMKenji Maeda
Kenji Maeda
DDDebananda Das
Debananda Das
HOHiromi Ogata-Aoki
Hiromi Ogata-Aoki
HNHirotomo Nakata
Hirotomo Nakata
TMToshikazu Miyakawa
Toshikazu Miyakawa
HMHiroaki Mitsuya
Hiroaki Mitsuya
We have characterized the structural and molecular interactions of CC-chemokine receptor 5 (CCR5) with three CCR5 inhibitors active against R5 human immunodeficiency virus type 1 (HIV-1) including the potent in vitro and in vivo CCR5 inhibitor aplaviroc (AVC). The data obtained with saturation binding assays and structural analyses delineated the key interactions responsible for the binding of CCR5 inhibitors with CCR5 and illustrated that their binding site is located in a predominantly lipophilic pocket in the interface of extracellular loops and within the upper transmembrane (TM) domain of CCR5. Mutations in the CCR5 binding sites of AVC decreased gp120 binding to CCR5 and the susceptibility to HIV-1 infection, although mutations in TM4 and TM5 that also decreased gp120 binding and HIV-1 infectivity had less effects on the binding of CC-chemokines, suggesting that CCR5 inhibition targeting appropriate regions might render the inhibition highly HIV-1-specific while preserving the CC chemokine-CCR5 interactions. The present data delineating residue by residue interactions of CCR5 with CCR5 inhibitors should not only help design more potent and more HIV-1-specific CCR5 inhibitors, but also give new insights into the dynamics of CC-chemokine-CCR5 interactions and the mechanisms of CCR5 involvement in the process of cellular entry of HIV-1.