13 research outputs found
Excitatory synaptic function is selectively enhanced in CA1 of hippocampal brain slices following <i>in vitro</i> SAHA treatment.
<p>(A) The median amplitude of mEPSCs was significantly increased in SAHA-treated slices (p<0.05, n = 14 vehicle, 14 SAHA), while there was no significant change to mEPSC frequency as measured by the median interval between events (p>0.05). Example mEPSC traces from vehicle and SAHA treated slices are shown inset (scale bar represents 10 pA and 250 ms). (B) SAHA treatment did not significantly alter the amplitude or frequency of mIPSCs (p>0.05, n = 14, 11). Example mIPSC traces from vehicle and SAHA treated slices are shown inset (scale bar represents 10 pA and 500 ms). All data points are plotted as mean ±SEM.</p
SAHA IC<sub>50</sub> values for each HDAC isozyme are shown as measured using <i>in vitro</i> enzymatic assays.
<p>Values are in µM and confidence intervals are in parentheses.</p
Pharmacokinetic analysis of SAHA following i.p. injection.
<p>A) Bioanalysis of the time course of total (top) and unbound (bottom) plasma, CSF, and brain levels of SAHA following a single 50 mg/kg ip injection (n = 3 mice/time point). The dotted red lines represent the SAHA concentration imposed on the <i>in vitro</i> slice cultures for the electrophysiological studies. B) Total (top) and unbound (bottom) SAHA levels are shown following a 150 mg/kg ip injection (n = 3/time point). All data is shown as mean ± SD.</p
Fear memory deficits in Tg2576 mice are not rescued by SAHA treatment.
<p>A) Compared to non-transgenic littermates (n = 15), Tg2576 (n = 14) mice showed significantly less freezing than wt mice when returned to the context in which conditioning occurred (context, p<0.001), when placed in an altered context (altered, p<0.01), or in response to the cue used for conditioning (cue, p<0.05). B) Tg2576 mice were treated daily for 33 days prior to, as well as during fear conditioning with either vehicle (n = 14), 25 mg/kg SAHA (n = 13), or 50 mg/kg SAHA (n = 13). There was no effect of treatment on the percentage of time Tg2576 mice spent freezing in response to the context, altered context, or cue (p>0.05). C) There was no effect of treatment on the percentage of time spent freezing during conditioning (p>0.05). D) There was no effect of treatment on the distance traveled in the open field test (total distance = 38.0±7.7 m for vehicle, 39.6±6.1 m for 25 mg/kg SAHA, and 34.2±5.2 m for 50 mg/kg SAHA, p>0.05). All data are plotted as mean ±SEM.</p
SAHA treated slices exhibit enhanced induction of LTP and impaired LTD.
<p>(A) An induction protocol that was subthreshold in vehicle treated slices readily evoked LTP in SAHA treated slices (p<0.05, n = 5,5). Example traces before and after LTP induction are shown in red for SAHA and black for vehicle treated slices (scale bars represent 20 pA and 20 ms). (B) An induction protocol that readily induced LTD in vehicle treated slices could not produce LTD in SAHA treated slices (p<0.05, n = 9 vehicle, 8 SAHA). Example traces before and after LTD induction are shown in red for SAHA and black for vehicle treated slices (scale bars represent 25 pA and 20 ms). Data are plotted as mean ±SEM.</p
Acute or chronic SAHA treatment does not produce significant drug class activity signatures as assessed by the SmartCube®.
<p>A. Groups of mice were treated acutely with a single injection of 50 mg/kg or 150 mg/kg SAHA or vehicle. In addition, a group was treated with valproate (225 mg/kg). Both does of SAHA were behaviorally inactive without a clear therapeutic signal. In contrast valproate was behaviorally active (p<0.001, discrimination index = 100%) with a strong anxiolytic signature and a mild psychostimulant signature. B. Groups of mice were treated daily for 14 days with SAHA or Valproate. While the lower dose of SAHA appeared behaviorally active (p<0.001, discrimination index = 88%), the activity was not consistent with any known therapeutic signal and the higher dose was not behaviorally active. In contrast valproate showed a strong behavioral activity (p<0.001, discrimination index = 98%) with a predominantly anxiolytic signature. C. The legend shows the 15 classes of behavioral activity that were assessed.</p
Intrinsic membrane properties are unaltered by SAHA treatment.
<p>(A) Representative traces from vehicle (black) and SAHA (red) treated slices during a series of hyperpolarizing and depolarizing current injection steps (scale bar represents 20 mV and 100 ms). There was no difference between vehicle and SAHA treated slices in the number of action potentials elicited by 500 ms current injection pulses at any of the current injection levels (p>0.05, n = 7,7). (B) Action potential threshold, input resistance, and membrane sag reflecting the hyperpolarization-induced inward current, were all unaltered following SAHA treatment (p>0.05). Data are plotted as mean ±SEM.</p
Pyrimidoaminotropanes as Potent, Selective, and Efficacious Small Molecule Kinase Inhibitors of the Mammalian Target of Rapamycin (mTOR)
We
have recently reported a series of tetrahydroquinazoline (THQ)
mTOR inhibitors that produced a clinical candidate <b>1</b> (GDC-0349).
Through insightful design, we hoped to discover and synthesize a new
series of small molecule inhibitors that could attenuate CYP3A4 time-dependent
inhibition commonly observed with the THQ scaffold, maintain or improve
aqueous solubility and oral absorption, reduce free drug clearance,
and selectively increase mTOR potency. Through key in vitro and in
vivo studies, we demonstrate that a pyrimidoaminotropane based core
was able to address each of these goals. This effort culminated in
the discovery of <b>20</b> (GNE-555), a highly potent, selective,
metabolically stable, and efficacious mTOR inhibitor
Discovery of GDC-0853: A Potent, Selective, and Noncovalent Bruton’s Tyrosine Kinase Inhibitor in Early Clinical Development
Bruton’s
tyrosine kinase (Btk) is a nonreceptor cytoplasmic
tyrosine kinase involved in B-cell and myeloid cell activation, downstream
of B-cell and Fcγ receptors, respectively. Preclinical studies
have indicated that inhibition of Btk activity might offer a potential
therapy in autoimmune diseases such as rheumatoid arthritis and systemic
lupus erythematosus. Here we disclose the discovery and preclinical
characterization of a potent, selective, and noncovalent Btk inhibitor
currently in clinical development. GDC-0853 (<b>29</b>) suppresses
B cell- and myeloid cell-mediated components of disease and demonstrates
dose-dependent activity in an <i>in vivo</i> rat model of
inflammatory arthritis. It demonstrates highly favorable safety, pharmacokinetic
(PK), and pharmacodynamic (PD) profiles in preclinical and Phase 2
studies ongoing in patients with rheumatoid arthritis, lupus, and
chronic spontaneous urticaria. On the basis of its potency, selectivity,
long target residence time, and noncovalent mode of inhibition, <b>29</b> has the potential to be a best-in-class Btk inhibitor for
a wide range of immunological indications
Discovery of GDC-0853: A Potent, Selective, and Noncovalent Bruton’s Tyrosine Kinase Inhibitor in Early Clinical Development
Bruton’s
tyrosine kinase (Btk) is a nonreceptor cytoplasmic
tyrosine kinase involved in B-cell and myeloid cell activation, downstream
of B-cell and Fcγ receptors, respectively. Preclinical studies
have indicated that inhibition of Btk activity might offer a potential
therapy in autoimmune diseases such as rheumatoid arthritis and systemic
lupus erythematosus. Here we disclose the discovery and preclinical
characterization of a potent, selective, and noncovalent Btk inhibitor
currently in clinical development. GDC-0853 (<b>29</b>) suppresses
B cell- and myeloid cell-mediated components of disease and demonstrates
dose-dependent activity in an <i>in vivo</i> rat model of
inflammatory arthritis. It demonstrates highly favorable safety, pharmacokinetic
(PK), and pharmacodynamic (PD) profiles in preclinical and Phase 2
studies ongoing in patients with rheumatoid arthritis, lupus, and
chronic spontaneous urticaria. On the basis of its potency, selectivity,
long target residence time, and noncovalent mode of inhibition, <b>29</b> has the potential to be a best-in-class Btk inhibitor for
a wide range of immunological indications