5 research outputs found
Wnt Inhibition Correlates with Human Embryonic Stem Cell Cardiomyogenesis: A Structure–Activity Relationship Study Based on Inhibitors for the Wnt Response
Human embryonic stem cell-based high-content screening
of 550 known
signal transduction modulators showed that one “lead”
(<b>1</b>, a recently described inhibitor of the proteolytic
degradation of Axin) stimulated cardiomyogenesis. Because Axin controls
canonical Wnt signaling, we conducted an investigation to determine
whether the cardiogenic activity of <b>1</b> is Wnt-dependent,
and we developed a structure–activity relationship to optimize
the cardiogenic properties of <b>1</b>. We prepared analogues
with a range of potencies (low nanomolar to inactive) for Wnt/β-catenin
inhibition and for cardiogenic induction. Both functional activities
correlated positively (<i>r</i><sup>2</sup> = 0.72). The
optimal compounds induced cardiogenesis 1.5-fold greater than <b>1</b> at 30-fold lower concentrations. In contrast, no correlation
was observed for cardiogenesis and modulation of transforming growth
factor β (TGFβ)/Smad signaling that prominently influences
cardiogenesis. Taken together, these data show that Wnt signaling
inhibition is essential for cardiogenic activity and that the pathway
can be targeted for the design of druglike cardiogenic molecules
Repurposing Suzuki Coupling Reagents as a Directed Fragment Library Targeting Serine Hydrolases and Related Enzymes
Serine
hydrolases are susceptible to potent reversible inhibition
by boronic acids. Large collections of chemically diverse boronic
acid fragments are commercially available because of their utility
in coupling chemistry. We repurposed the approximately 650 boronic
acid reagents in our collection as a directed fragment library targeting
serine hydrolases and related enzymes. Highly efficient hits (LE >
0.6) often result. The utility of the approach is illustrated with
the results against autotaxin, a phospholipase implicated in cardiovascular
disease
Synthesis and SAR of <i>b</i>‑Annulated 1,4-Dihydropyridines Define Cardiomyogenic Compounds as Novel Inhibitors of TGFβ Signaling
A medium-throughput murine embryonic stem cell (mESC)-based
high-content
screening of 17000 small molecules for cardiogenesis led to the identification
of a <i>b</i>-annulated 1,4-dihydropyridine (1,4-DHP) that
inhibited transforming growth factor β (TGFβ)/Smad signaling
by clearing the type II TGFβ receptor from the cell surface.
Because this is an unprecedented mechanism of action, we explored
the series’ structure–activity relationship (SAR) based
on TGFβ inhibition, and evaluated SAR aspects for cell-surface
clearance of TGFβ receptor II (TGFBR2) and for biological activity
in mESCs. We determined a pharmacophore and generated 1,4-DHPs with
IC<sub>50</sub>s for TGFβ inhibition in the nanomolar range
(e.g., compound <b>28</b>, 170 nM). Stereochemical consequences
of a chiral center at the 4-position was evaluated, revealing 10-
to 15-fold more potent TGFβ inhibition for the (+)- than the
(−) enantiomer. This stereopreference was not observed for
the low level inhibition against Activin A signaling and was reversed
for effects on calcium handling in HL-1 cells
A Fragment-Based Approach to Identifying <i>S</i>‑Adenosyl‑l‑methionine -Competitive Inhibitors of Catechol <i>O</i>‑Methyl Transferase (COMT).
Catechol <i>O</i>-methyl
transferase belongs to the diverse
family of <i>S</i>-adenosyl-l-methionine transferases.
It is a target involved in the treatment of Parkinson’s disease.
Here we present a fragment-based screening approach to discover noncatechol
derived COMT inhibitors which bind at the SAM binding pocket. We describe
the identification and characterization of a series of highly ligand
efficient SAM competitive bisaryl fragments (LE = 0.33–0.58).
We also present the first SAM-competitive small-molecule COMT co-complex
crystal structure
Structure-Based Design of ASK1 Inhibitors as Potential Agents for Heart Failure
Apoptosis
signal-regulating kinase 1 (ASK1/MAP3K) is a mitogen-activated
protein kinase family member shown to contribute to acute ischemia/reperfusion
injury. Using structure-based drug design, deconstruction, and reoptimization
of a known ASK1 inhibitor, a lead compound was identified. This compound
displayed robust MAP3K pathway inhibition and reduction of infarct
size in an isolated perfused heart model of cardiac injury