A Phthalimide Derivative That Inhibits Centrosomal Clustering Is Effective on Multiple Myeloma

Despite the introduction of newly developed drugs such as lenalidomide and bortezomib, patients with multiple myeloma are still difficult to treat and have a poor prognosis. In order to find novel drugs that are effective for multiple myeloma, we tested the antitumor activity of 29 phthalimide derivatives against several multiple myeloma cell lines. Among these derivatives, 2-(2,6-diisopropylphenyl)-5-amino-1H-isoindole-1,3- dione (TC11) was found to be a potent inhibitor of tumor cell proliferation and an inducer of apoptosis via activation of caspase-3, 8 and 9. This compound also showed in vivo activity against multiple myeloma cell line KMS34 tumor xenografts in ICR/SCID mice. By means of mRNA display selection on a microfluidic chip, the target protein of TC11 was identified as nucleophosmin 1 (NPM). Binding of TC11 and NPM monomer was confirmed by surface plasmon resonance. Immunofluorescence and NPM knockdown studies in HeLa cells suggested that TC11 inhibits centrosomal clustering by inhibiting the centrosomal-regulatory function of NPM, thereby inducing multipolar mitotic cells, which undergo apoptosis. NPM may become a novel target for development of antitumor drugs active against multiple myeloma

Reduced N-acetylaspartate levels in mice lacking aralar, a brain- and muscle-type mitochondrial aspartate-glutamate carrier

Aralar is a mitochondrial calcium-regulated aspartate-glutamate carrier mainly distributed in brain and skeletal muscle, involved in the transport of aspartate from mitochondria to cytosol, and in the transfer of cytosolic reducing equivalents into mitochondria as a member of the malate-aspartate NADH shuttle. In the present study, we describe the characteristics of aralar-deficient (Aralar-/-) mice, generated by a gene-trap method, showing no aralar mRNA and protein, and no detectable malate-aspartate shuttle activity in skeletal muscle and brain mitochondria. Aralar-/- mice were growth-retarded, exhibited generalized tremoring, and had pronounced motor coordination defects along with an impaired myelination in the central nervous system. Analysis of lipid components showed a marked decrease in the myelin lipid galactosyl cerebroside. The content of the myelin lipid precursor, N-acetylaspartate, and that of aspartate are drastically decreased in the brain of Aralar-/- mice. The defect in N-acetylaspartate production was also observed in cell extracts from primary neuronal cultures derived from Aralar-/- mouse embryos. These results show that aralar plays an important role in myelin formation by providing aspartate for the synthesis of N-acetylaspartate in neuronal cell

Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.

Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eugenol levels and up to 22-fold eugenol glycoside levels in leaves of transgenic aspen plants. The overexpression of PhEGS alone resulted in a subtle increase in either eugenol or eugenol glycosides, and the overexpression of both PhCFAT and PhEGS resulted in significant increases in the levels of both eugenol and eugenol glycosides which were nonetheless lower than the increases seen with overexpression of PhCFAT alone. On the other hand, overexpression of PhCFAT in transgenic Arabidopsis and tobacco did not cause any synthesis of eugenol. These results indicate that aspen leaves, but not Arabidopsis and tobacco leaves, have a partially active pathway to eugenol that is limited by the level of CFAT activity and thus the flux of this pathway can be increased by the introduction of a single heterologous gene

Coordinated Respiratory Motor Activity in Nerves Innervating the Upper Airway Muscles in Rats.

Maintaining the patency of the upper airway during breathing is of vital importance. The activity of various muscles is related to the patency of the upper airway. In the present study, we examined the respiratory motor activity in the efferent nerves innervating the upper airway muscles to determine the movements of the upper airway during respiration under normocapnic conditions (pH = 7.4) and in hypercapnic acidosis (pH = 7.2). Experiments were performed on arterially perfused decerebrate rats aged between postnatal days 21-35. We recorded the efferent nerve activity in a branch of the cervical spinal nerve innervating the infrahyoid muscles (CN), the hypoglossal nerve (HGN), the external branch of the superior laryngeal nerve (SLN), and the recurrent laryngeal nerve (RLN) with the phrenic nerve (PN). Inspiratory nerve discharges were observed in all these nerves under normocapnic conditions. The onset of inspiratory discharges in the CN and HGN was slightly prior to those in the SLN and RLN. When the CO2 concentration in the perfusate was increased from 5% to 8% to prepare for hypercapnic acidosis, the peak amplitudes of the inspiratory discharges in all the recorded nerves were increased. Moreover, hypercapnic acidosis induced pre-inspiratory discharges in the CN, HGN, SLN, and RLN. The onset of pre-inspiratory discharges in the CN, HGN, and SLN was prior to that of discharges in the RLN. These results suggest that the securing of the airway that occurs a certain time before dilation of the glottis may facilitate ventilation and improve hypercapnic acidosis

Correlation between abdominal nerve (AbN) activity and CN activity.

<p>(A) Original and integrated traces of AbN, CN, and PN activity during normocapnia (5% CO₂, 95% O₂), hypercapnia (8% CO₂, 92% O₂), and recovery (5% CO₂, 95% O₂). (B) Traces averaged from consecutive integrated sweeps for 1 min in the preparation shown in (A). The filled arrowheads show the onset of nerve discharges. (C) Comparison of the duration of the AbN pre-I discharge, CN pre-I discharge, and respiratory cycle in the preparation shown in (A). Black bars show the times that the traces in (A) were recorded. The black arrow shows the time point at which the respiratory duration became shortest. The white arrow shows the time point at which the abdominal discharge appeared. (D) Correlation between the duration of the CN pre-I phase discharge and duration of the AbN pre-I discharge in the preparation shown in (A).</p

The discharge patterns of the CN, SLN, RLN, and HGN under normocapnic conditions.

<p>Averaged traces from two preparations shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166436#pone.0166436.g001" target="_blank">Fig 1</a> were normalized via the peak amplitude.</p

Respiratory motor activity under normocapnic conditions and hypercapnic acidosis.

<p>(A) Original and integrated traces of CN, SLN, RLN, and PN activity during normocapnia (5% CO₂, 95% O₂), hypercapnia (8% CO₂, 92% O₂), and recovery (5% CO₂, 95% O₂). (B) Traces averaged from consecutive integrated sweeps for 1 min in the preparation shown in (A). The black and gray traces show the averaged traces during hypercapnia and normocapnia, respectively. The filled arrowheads show the onset of the nerve discharges. The open arrowheads show the pre-inspiration (pre-I) discharges. ‘<i>I</i>’ and ‘<i>E</i>’ demonstrate the inspiratory and expiratory phases, respectively. (C) Original and integrated traces of the CN, SLN, HGN, and PN activity obtained from a different preparation from (A). (D) Traces averaged from consecutive integrated sweeps for 1 min in the preparation shown in (C).</p

The discharge patterns of the CN, SLN, RLN, and HGN in hypercapnic acidosis.

<p>The averaged traces from two preparations shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166436#pone.0166436.g001" target="_blank">Fig 1</a> were normalized via the peak amplitude of the pre-I discharges.</p

Comparison of variables of PN activity during normocapnia (5% CO₂) and hypercapnia (8% CO₂) (<i>n</i> = 21).

<p>Comparison of variables of PN activity during normocapnia (5% CO₂) and hypercapnia (8% CO₂) (<i>n</i> = 21).</p