ML 277

Lumbar interbody fusion with utilization of recombinant human bone morphogenetic protein: a retrospective real-life study about 277 patients.[Pubmed:28281191]

Neurosurg Rev. 2018 Jan;41(1):189-196.

The purpose of this study was to report an independent real-life experience about the use of recombinant human bone morphogenetic protein 2 in lumbar interbody fusion with a special focus on complications. This is a retrospective single-center cohort study between 2007 and 2013 including 277 patients treated for anterior or posterior lumbar fusion with recombinant human bone morphogenetic protein 2. We report the complications occurring during the 12 first postoperative months and analyze the fusion rate on X-rays. There are 58 cases (22.8%) of clinical complications. In 15 cases (5.9%), these complications were related to the use of recombinant human bone morphogenetic protein 2. Only one patient (0.4%) required a new intervention due to recombinant human bone morphogenetic protein 2. Fusion rate at 1 year was 98%. The low rate of specific complication suggests that recombinant human bone morphogenetic protein 2 can be safe and effective in anterior and posterior interbody fusion when used with simple precautions.

Dynamic subunit stoichiometry confers a progressive continuum of pharmacological sensitivity by KCNQ potassium channels.[Pubmed:23650380]

Proc Natl Acad Sci U S A. 2013 May 21;110(21):8732-7.

Voltage-gated KCNQ1 (Kv7.1) potassium channels are expressed abundantly in heart but they are also found in multiple other tissues. Differential coassembly with single transmembrane KCNE beta subunits in different cell types gives rise to a variety of biophysical properties, hence endowing distinct physiological roles for KCNQ1-KCNEx complexes. Mutations in either KCNQ1 or KCNE1 genes result in diseases in brain, heart, and the respiratory system. In addition to complexities arising from existence of five KCNE subunits, KCNE1 to KCNE5, recent studies in heterologous systems suggest unorthodox stoichiometric dynamics in subunit assembly is dependent on KCNE expression levels. The resultant KCNQ1-KCNE channel complexes may have a range of zero to two or even up to four KCNE subunits coassembling per KCNQ1 tetramer. These findings underscore the need to assess the selectivity of small-molecule KCNQ1 modulators on these different assemblies. Here we report a unique small-molecule gating modulator, ML277, that potentiates both homomultimeric KCNQ1 channels and unsaturated heteromultimeric (KCNQ1)4(KCNE1)n (n < 4) channels. Progressive increase of KCNE1 or KCNE3 expression reduces efficacy of ML277 and eventually abolishes ML277-mediated augmentation. In cardiomyocytes, the slowly activating delayed rectifier potassium current, or IKs, is believed to be a heteromultimeric combination of KCNQ1 and KCNE1, but it is not entirely clear whether IKs is mediated by KCNE-saturated KCNQ1 channels or by channels with intermediate stoichiometries. We found ML277 effectively augments IKs current of cultured human cardiomyocytes and shortens action potential duration. These data indicate that unsaturated heteromultimeric (KCNQ1)4(KCNE1)n channels are present as components of IKs and are pharmacologically distinct from KCNE-saturated KCNQ1-KCNE1 channels.

Identification of (R)-N-(4-(4-methoxyphenyl)thiazol-2-yl)-1-tosylpiperidine-2-carboxamide, ML277, as a novel, potent and selective K(v)7.1 (KCNQ1) potassium channel activator.[Pubmed:22910039]

Bioorg Med Chem Lett. 2012 Sep 15;22(18):5936-41.

A high-throughput screen utilizing a depolarization-triggered thallium influx through KCNQ1 channels was developed and used to screen the MLSMR collection of over 300,000 compounds. An iterative medicinal chemistry approach was initiated and from this effort, ML277 was identified as a potent activator of KCNQ1 channels (EC(50)=260 nM). ML277 was shown to be highly selective against other KCNQ channels (>100-fold selectivity versus KCNQ2 and KCNQ4) as well as against the distantly related hERG potassium channel.