Application of protein knockdown strategy targeting β-sheet structure to multiple disease-associated polyglutamine proteins.

Polyglutamine diseases are a class of neurodegenerative diseases associated with the accumulation of aggregated mutant proteins. We previously developed a class of degradation-inducing agents targeting the β-sheet-rich structure typical of such aggregates, and we showed that these agents dose-, time-, and proteasome-dependently decrease the intracellular level of mutant huntingtin with an extended polyglutamine tract, which correlates well with the severity of Huntington's disease. Here, we demonstrate that the same agents also deplete other polyglutamine disease-related proteins: mutant ataxin-3 and ataxin-7 in cells from spino-cerebellar ataxia patients, and mutant atrophin-1 in cells from dentatorubral-pallidoluysian atrophy patients.

Effects of muscarinic acetylcholine receptor stimulation on the differentiation of mouse induced pluripotent stem cells into neural progenitor cells.

Muscarinic acetylcholine receptors (mAchRs), which are expressed in various embryonic cells, may regulate neuronal differentiation. In the present study, we examined the effects of mAchR stimulation on the differentiation of mouse induced pluripotent stem (iPS) cells into neural progenitor cells (NPCs). Mouse iPS cells were cultured on ultra-low attachment dishes to induce embryoid body (EB) formation.

Structural development of tetrachlorophthalimides as liver X receptor β (LXRβ)-selective agonists with improved aqueous solubility.

LXRβ-selective agonists are promising candidates to improve atherosclerosis without increasing plasma or hepatic TG levels. We have reported a series of tetrachlorophthalimide analogs as an LXRβ-selective agonist. However, they exhibited poor aqueous solubility probably due to its high hydrophobicity and highly rigid and plane structure.

Degradation of huntingtin mediated by a hybrid molecule composed of IAP antagonist linked to phenyldiazenyl benzothiazole derivative.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by aggregation of mutant huntingtin (mHtt), and removal of mHtt is expected as a potential therapeutic option. We previously reported protein knockdown of Htt by using hybrid small molecules (Htt degraders) consisting of BE04, a ligand of ubiquitin ligase (E3), linked to probes for protein aggregates. Here, in order to examine the effect of changing the ligand, we synthesized a similar Htt degrader utilizing MV1, an antagonist of the inhibitor of apoptosis protein (IAP) family (a subgroup of ubiquitin E3 ligases), which is expected to have a higher affinity and specificity for IAP, as compared with BE04.

Discovery of Small Molecules that Induce the Degradation of Huntingtin.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the aggregation of mutant huntingtin (mHtt), and removal of toxic mHtt is expected to be an effective therapeutic approach. We designed two small hybrid molecules (1 and 2) by linking a ligand for ubiquitin ligase (cellular inhibitor of apoptosis protein 1; cIAP1) with probes for mHtt aggregates, anticipating that these compounds would recruit cIAP1 to mHtt and induce selective degradation by the ubiquitin-proteasome system. The synthesized compounds reduced mHtt levels in HD patient fibroblasts and appear to be promising candidates for the development of a treatment for HD.

Structure-activity relationships of rosiglitazone for peroxisome proliferator-activated receptor gamma transrepression.

Anti-inflammatory effects of peroxisome proliferator-activated receptor gamma (PPRAγ) ligands are thought to be largely due to PPARγ-mediated transrepression. Thus, transrepression-selective PPARγ ligands without agonistic activity or with only partial agonistic activity should exhibit anti-inflammatory properties with reduced side effects. Here, we investigated the structure-activity relationships (SARs) of PPARγ agonist rosiglitazone, focusing on transrepression activity.

Development of Tetrachlorophthalimides as Liver X Receptor β (LXRβ)-Selective Agonists.

Liver X receptor (LXR) agonists are candidates for the treatment of atherosclerosis via induction of ABCA1 (ATP-binding cassette A1) gene expression, which contributes to reverse cholesterol transport (RCT) and to cholesterol efflux from the liver and intestine. However, LXR agonists also induce genes involved in lipogenesis, such as SREBP-1c (sterol regulatory binding element protein 1c) and FAS (fatty acid synthase), thereby causing an undesirable increase in plasma and hepatic triglyceride (TG) levels. Recent studies indicate that LXRα contributes to lipogenesis in liver, and selective LXRβ activation improves RCT in mice.

Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains.

CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis.

Styrylphenylphthalimides as Novel Transrepression-Selective Liver X Receptor (LXR) Modulators.

Anti-inflammatory effects of liver X receptor (LXR) ligands are thought to be largely due to LXR-mediated transrepression, whereas side effects are caused by activation of LXR-responsive gene expression (transactivation). Therefore, selective LXR modulators that preferentially exhibit transrepression activity should exhibit anti-inflammatory properties with fewer side effects. Here, we synthesized a series of styrylphenylphthalimide analogues and evaluated their structure-activity relationships focusing on LXRs-transactivating-agonistic/antagonistic activities and transrepressional activity.

SHP-2 inhibits tyrosine phosphorylation of Cas-L and regulates cell migration.

The Src homology 2 (SH2) domain-containing protein tyrosine phosphatase, SHP-2, plays an important role in cell migration by interacting with various proteins. In this report, we demonstrated that SHP-2 inhibits tyrosine phosphorylation of Crk-associated substrate lymphocyte type (Cas-L), a docking protein which mediates cell migration, and found that SHP-2 negatively regulates migration of A549 lung adenocarcinoma cells induced by fibronectin (FN). We showed that overexpressed SHP-2 co-localizes with Cas-L at focal adhesions and that exogenous expression of SHP-2 abrogates cell migration mediated by Cas-L.

Patent ductus venosus in children: a case report and review of the literature.

A 10-year-old girl with a patent ductus venosus associated with multiple autoimmune disorders presented with hypoxia, cyanosis of her lips, and exertional dyspnea. Ultrasonography and abdominal computed tomography of the liver showed a communication between the portal vein and the inferior vena cava through a patent ductus venosus. Portography showed flow from the portal vein directly into the inferior vena cava via the portosystemic shunt.