50 research outputs found
<i>In Vivo</i> Near-Infrared Fluorescence Imaging Selective for Soluble Amyloid β Aggregates Using y‑Shaped BODIPY Derivative
Soluble amyloid β (Aβ) aggregates, suggested
to be
the most toxic forms of Aβ, draw attention as therapeutic targets
and biomarkers of Alzheimer’s disease (AD). As soluble Aβ
aggregates are transient and diverse, imaging their diverse forms in vivo is expected to have a marked impact on research
and diagnosis of AD. Herein, we report a near-infrared fluorescent
(NIRF) probe, BAOP-16, targeting diverse soluble Aβ aggregates.
BAOP-16, whose molecular shape resembles “y”, showed
a marked selective increase in fluorescence intensity upon binding
to soluble Aβ aggregates in the near-infrared region and a high
binding affinity for them. Additionally, BAOP-16 could detect Aβ
oligomers in the brains of Aβ-inoculated model mice. In an in vivo fluorescence imaging study of BAOP-16, brains of
AD model mice displayed significantly higher fluorescence signals
than those of wild-type mice. These results indicate that BAOP-16
could be useful for the in vivo NIRF imaging of diverse
soluble Aβ aggregates
<i>In Vivo</i> Near-Infrared Fluorescence Imaging Selective for Soluble Amyloid β Aggregates Using y‑Shaped BODIPY Derivative
Soluble amyloid β (Aβ) aggregates, suggested
to be
the most toxic forms of Aβ, draw attention as therapeutic targets
and biomarkers of Alzheimer’s disease (AD). As soluble Aβ
aggregates are transient and diverse, imaging their diverse forms in vivo is expected to have a marked impact on research
and diagnosis of AD. Herein, we report a near-infrared fluorescent
(NIRF) probe, BAOP-16, targeting diverse soluble Aβ aggregates.
BAOP-16, whose molecular shape resembles “y”, showed
a marked selective increase in fluorescence intensity upon binding
to soluble Aβ aggregates in the near-infrared region and a high
binding affinity for them. Additionally, BAOP-16 could detect Aβ
oligomers in the brains of Aβ-inoculated model mice. In an in vivo fluorescence imaging study of BAOP-16, brains of
AD model mice displayed significantly higher fluorescence signals
than those of wild-type mice. These results indicate that BAOP-16
could be useful for the in vivo NIRF imaging of diverse
soluble Aβ aggregates
Development of Novel Bimodal Agents Based on Near-Infrared BODIPY-Conjugated Hoechst Derivatives for Combined Use in Auger Electron and Photodynamic Cancer Therapy
Auger
electron therapy and photodynamic therapy (PDT) have attracted
attention as powerful anticancer modalities. Herein, we report the
development of novel bimodal agents for Auger electron therapy and
PDT, and their application to combination therapy. [125I]NBH-1/NBH-1 and [125I]NBH-2/NBH-2, composing Hoechst
and iodostyryl-BODIPY, were synthesized and evaluated regarding their
usefulness as bimodal agents. [125I]NBH-1 showed significantly
higher nuclear uptake than [125I]NBH-2 and radioactivity-dependent
cytotoxicity induced by Auger electrons. In addition, NBH-1 exhibited
photoinduced cytotoxicity. Combination therapy using [125I]NBH-1 and NBH-1 with light irradiation induced a superior cytotoxicity
to these treatments alone. In tumor-bearing mice injected with NBH-1
or [125I]NBH-1/NBH-1 under light irradiation, significant
tumor growth inhibition was observed compared with that of the control
group. Especially, [125I]NBH-1/NBH-1 under light irradiation
showed the strongest therapeutic effects among all treatments. These
results suggest that [125I]NBH-1/NBH-1 is a potent bimodal
agent for Auger therapy and PDT and that combination therapy using
[125I]NBH-1 and NBH-1 shows enhanced therapeutic efficacy
BODIPY-Based Molecular Probe for Imaging of Cerebral β-Amyloid Plaques
We designed and synthesized a BODIPY-based probe (BAP-1)
for the
imaging of β-amyloid plaques in the brain. In binding experiments
in vitro, BAP-1 showed excellent affinity for synthetic Aβ aggregates.
β-Amyloid plaques in Tg2576 mouse brain were clearly visualized
with BAP-1. In addition, the labeling of β-amyloid plaques was
demonstrated in vivo in Tg2576 mice. These results suggest BAP-1 to
be a useful fluorescent probe for the optical imaging of cerebral
β-amyloid plaques in patients with Alzheimer’s disease
Smart Near-Infrared Fluorescence Probes with Donor–Acceptor Structure for in Vivo Detection of β‑Amyloid Deposits
The deposition of β-amyloid
(Aβ) plaques in the parenchymal
and cortical brain is accepted as the main pathological hallmark of
Alzheimer’s disease (AD); however, early detection of AD still
presents a challenge. With the assistance of molecular imaging techniques,
imaging agents specifically targeting Aβ plaques in the brain
may lead to the early diagnosis of AD. Herein, we report the design,
synthesis, and evaluation of a series of smart near-infrared fluorescence
(NIRF) imaging probes with donor–acceptor architecture bridged
by a conjugated π-electron chain for Aβ plaques. The chemical
structure of these NIRF probes is completely different from Congo
Red and Thioflavin-T. Probes with a longer conjugated π system
(carbon–carbon double bond) displayed maximum emission in PBS
(>650 nm), which falls in the best range for NIRF probes. These
probes
were proved to have affinity to Aβ plaques in fluorescent staining
of brain sections from an AD patient and double transgenic mice, as
well as in an in vitro binding assay using Aβ<sub>1–42</sub> aggregates. One probe with high affinity (<i>K</i><sub>i</sub> = 37 nM, <i>K</i><sub>d</sub> = 27 nM) was selected
for in vivo imaging. It can penetrate the blood–brain barrier
of nude mice efficiently and is quickly washed out of the normal brain.
Moreover, after intravenous injection of this probe, 22-month-old
APPswe/PSEN1 mice exhibited a higher relative signal than control
mice over the same period of time, and ex vivo fluorescent observations
confirmed the existence of Aβ plaques. In summary, this probe
meets most of the requirements for a NIRF contrast agent for the detection
of Aβ plaques both in vitro and in vivo
Cirsium maritimum Makino Inhibits the Antigen/Immunoglobulin-E-Mediated Allergic Response <i>In Vitro</i> and <i>In Vivo</i>
We investigated whether Cirsium maritimum Makino can inhibit immunoglobulin-E-mediated
allergic response in
rat basophilic leukemia (RBL-2H3) cells and passive cutaneous anaphylaxis
(PCA) in BALB/c mice. <i>In vitro</i>, the ethyl acetate
extract of C. maritimum Makino (ECMM)
significantly inhibited β-hexosaminidase release and decreased
intracellular Ca<sup>2+</sup> levels in RBL-2H3 cells. Moreover, ECMM
leaves more strongly suppressed the release of β-hexosaminidase
than ECMM flowers. ECMM leaves also significantly suppressed the PCA
reaction in the murine model. High-performance liquid chromatography
and <sup>1</sup>H and <sup>13</sup>C nuclear magnetic resonance indicated
that cirsimaritin, a flavonoid, was concentrated in active fractions
of the extract. Our findings suggest that ECMM leaves have a potential
regulatory effect on allergic reactions that may be mediated by mast
cells. Furthermore, cirsimaritin may be the active anti-allergic component
in C. maritimum Makino
Proteomics of Neuropathic Pain: Proteins and Signaling Pathways Affected in a Rat Model
The myriad proteins may be involved
in the mechanisms underlying
the development and maintenance of neuropathic pain, an extremely
disabling condition that originates from pathology of the nervous
system. To address the mechanisms, we here analyzed proteins and cellular
networks in the dorsal spinal cord mediating pain processing in a
well-established rat model of neuropathic pain induced by spinal nerve
ligation (SNL). Labeling-based proteomic methods together with high-resolution
mass spectrometry for proteome analysis were applied. 38 proteins
including synapsin 1 and microtubule-associated protein 2 were identified
as differently expressed in the SNL group. Pathway analysis suggests
that maladaptive changes in the levels of these proteins may contribute
to abnormal synaptic transmission and neuronal intracellular signaling
underlying the onset and development of neuropathic pain
Development of Novel <sup>111</sup>In/<sup>225</sup>Ac-Labeled Agent Targeting PSMA for Highly Efficient Cancer Radiotheranostics
Prostate-specific membrane antigen (PSMA) is a promising
target
for metastatic castration-resistant prostate cancer. We previously
reported the effectiveness of PSMA-DA1 as a PSMA-targeting radiotheranostic
agent containing an albumin binder moiety. To further enhance tumor
uptake, we newly designed PSMA-NAT-DA1 (PNT-DA1) by the introduction
of a lipophilic linker into PSMA-DA1. The PSMA affinity of [111In]In-PNT-DA1 was increased (Kd = 8.20
nM) compared with that of [111In]In-PSMA-DA1 (Kd = 89.4 nM). [111In]In-PNT-DA1 showed markedly
high tumor accumulation (131.6% injected dose/g at 48 h post-injection),
and [111In]In-PNT-DA1 enabled the visualization of the
tumor clearly at 24 h post-injection with SPECT/CT imaging. The administration
of [225Ac]Ac-PNT-DA1 (2.5 kBq) led to shrinkage of the
tumor without marked toxicity, and the antitumor effects of [225Ac]Ac-PNT-DA1 were superior to those of [225Ac]Ac-PSMA-DA1
and [225Ac]Ac-PSMA-617, which is the current gold standard
for PSMA-targeting 225Ac-endoradiotherapy. These results
suggest that the combination of [111In]In-PNT-DA1 and [225Ac]Ac-PNT-DA1 comprises a promising method of PSMA-targeting
radiotheranostics
Development of Novel <sup>111</sup>In/<sup>225</sup>Ac-Labeled Agent Targeting PSMA for Highly Efficient Cancer Radiotheranostics
Prostate-specific membrane antigen (PSMA) is a promising
target
for metastatic castration-resistant prostate cancer. We previously
reported the effectiveness of PSMA-DA1 as a PSMA-targeting radiotheranostic
agent containing an albumin binder moiety. To further enhance tumor
uptake, we newly designed PSMA-NAT-DA1 (PNT-DA1) by the introduction
of a lipophilic linker into PSMA-DA1. The PSMA affinity of [111In]In-PNT-DA1 was increased (Kd = 8.20
nM) compared with that of [111In]In-PSMA-DA1 (Kd = 89.4 nM). [111In]In-PNT-DA1 showed markedly
high tumor accumulation (131.6% injected dose/g at 48 h post-injection),
and [111In]In-PNT-DA1 enabled the visualization of the
tumor clearly at 24 h post-injection with SPECT/CT imaging. The administration
of [225Ac]Ac-PNT-DA1 (2.5 kBq) led to shrinkage of the
tumor without marked toxicity, and the antitumor effects of [225Ac]Ac-PNT-DA1 were superior to those of [225Ac]Ac-PSMA-DA1
and [225Ac]Ac-PSMA-617, which is the current gold standard
for PSMA-targeting 225Ac-endoradiotherapy. These results
suggest that the combination of [111In]In-PNT-DA1 and [225Ac]Ac-PNT-DA1 comprises a promising method of PSMA-targeting
radiotheranostics