Case Report: A patient with spinocerebellar ataxia type 31 and sporadic Creutzfeldt-Jakob disease

We report a Japanese patient with spinocerebellar ataxia type 31 (SCA31) and sporadic Creutzfeldt-Jakob disease (sCJD). A 52-year-old man developed progressive cognitive impairment after the appearance of cerebellar symptoms. Brain MR diffusion-weighted imaging (DWI) demonstrated a slowly expanding hyperintense lesion in the cerebral cortex. The patient was finally diagnosed as having both SCA31 and sCJD by identification of genetic mutations and by real-time quaking-induced conversion (RT-QUIC) analysis of the cerebrospinal fluid (CSF), respectively. Here, we report the clinical details of this rare combined case, with particular reference to the association between prion protein and the early onset of SCA31.     

Identification of proteins that bind to the neuroprotective agent neoechinulin A

Neoechinulin A is an indole alkaloid with several biological activities. We previously reported that this compound protects neuronal PC12 cells from cytotoxicity induced by the peroxynitrite generator 3-morpholinosydnonimine (SIN-1), but the target proteins and precise mechanism of action of neoechinulin A were unclear. Here, we employed a phage display screen to identify proteins that bind directly with neoechinulin A. Our findings identified two proteins, chromogranin B and glutaredoxin 3, as candidate target binding partners for the alkaloid. QCM analyses revealed that neoechinulin A displays high affinity for both chromogranin B and glutaredoxin 3. RNA interference-mediated depletion of chromogranin B decreased the sensitivity of PC12 cells against SIN-1. Our results suggested chromogranin B is a plausible target of neoechinulin A.     

Synthesis and characterization of radioiodinated 3-phenethyl-2-indolinone derivatives for SPECT imaging of survivin in tumors

Survivin, overexpressed in most cancers, is associated with poor prognosis and resistance to radiation therapy and chemotherapy. Herein, we report the synthesis of three 3-phenethyl-2-indolinone derivatives and their application as in vivo imaging agents for survivin. Of these, 3-(2-(benzo[d][1,3]dioxol-5-yl)-2-oxoethyl)-3-hydroxy-5- iodoindolin-2-one (IPI-1) showed the highest binding affinity (K_d?=?68.3?nM) to recombinant human survivin, as determined by quartz crystal microbalance (QCM). In vitro studies demonstrated that the [¹²⁵I]IPI-1 binding in survivin-positive MDA-MB-231 cells was significantly higher than that in survivin-negative MCF-10A cells. In addition, uptake of [¹²⁵I]IPI-1 by MDA-MB-231 cells decreased in a dose-dependent manner in the presence of the high-affinity survivin ligand S12; this is indicative of specific binding of [¹²⁵I]IPI-1 to cellular survivin protein in vitro. Biodistribution studies in MDA-MB-231 tumor-bearing mice demonstrated the moderate uptake of [¹²⁵I]IPI-1 in the tumor tissue (1.37%?ID/g) at 30?min that decreased to 0.32%?ID/g at 180?min. Co-injection of S12 (2.5?mg/kg) slightly reduced tumor uptake and the tumor/muscle ratio of [¹²⁵I]IPI-1. Although further structural modifications are necessary to improve pharmacokinetic properties, our results indicate that PI derivatives may be useful as tumor-imaging probes targeting survivin.     

Synthesis of polyozellin,a prolyl oligopeptidase inhibitor,and its structural revision

Polyozellin is a p-terphenyl compound which was isolated from Polyozellus multiplex, and exhibits an inhibitory activity against prolyl oligopeptidase (POP). Its structure was assigned as 1 having a p-terphenyl skeleton including a p-substituted dibenzofuran moiety by spectroscopic analyses and chemical means. This paper describes the total syntheses of the proposed structure 1 for polyozellin and its o-isomer 2, revising the structure of polyozellin to the latter. These syntheses involved a double Suzuki-Miyaura coupling using chlorophenylboronic acid as a common key building block, and Cu mediated Ullmann cyclization as key steps. The inhibitory activities of synthetic compounds against POP and cancer cells were also evaluated.     

Regulatory factors on parathyroid hormone-related peptide production by primary culture of lactating rat mammary gland.

Parathyroid hormone-related protein (PTHrP) is a major cause of humoral hypercalcemia of malignancy, but has also been widely found in fetal and adult non-neoplastic tissues. Lactating mammary gland has been shown to produce large amounts of PTHrP, and high levels of PTHrP have been measured in milk. We have examined the influences of several substances on the secretion of two different forms of PTHrP by primary cultures of mammary cells isolated from lactating rats to examine the regulatory mechanisms of PTHrP production by mammary cells. Primary cultures of mammary cells seeded at a density of 10(5) cells per 35 mm culture dish were grown on collagen gels. First, after cells were left 24 hours for attachment and incubated in 2 % FCS containing medium with for 12 hours, PTHrP (1 - 87) secretions were measured in conditioned medium with hormone supplementation for 1, 24 and 48 hours. Progesterone (10(-7) - 10(-5) mol/l) significantly suppressed PTHrP (1 - 87) secretion in a dose-dependent manner (p < 0.01), while 17beta-estradiol had no influence on PTHrP (1 - 87) secretion. Prolactin, a known stimulator of PTHrP expression in vivo, had no effect in this in vitro model. Second, PTHrP (1 - 34) secretion levels from confluent lactating mammary cells for 24 hours were evaluated. The same results were obtained in the case of PTHrP (1 - 87) secretion from non-confluent cells. Furthermore, dexamethasone (10(-6) mol/l) significantly suppressed PTHrP (1 - 34) secretion (p < 0.01). These results suggest that PTHrP production from the lactating mammary gland is suppressed by progesterone as well as dexamethasone. Progesterone dramatically falls after delivery, thus possibly accelerating PTHrP production by lactating mammary glands and resulting in considerable amounts of PTHrP secreted into the milk.     

Splicing of human chloride channel 1

Expression of chloride channel 1 (CLCN1/ClC-1) in skeletal muscle is driven by alternative splicing, a process regulated in part by RNA-binding protein families MBNL and CELF. Aberrant splicing of CLCN1 produces many mRNAs, which were translated into inactive proteins, resulting in myotonia in myotonic dystrophy (DM), a genetic disorder caused by the expansion of a CTG or CCTG repeat. This increase in abnormal splicing variants containing exons 6B, 7A or the insertion of a TAG stop codon just before exon 7 leads to a decrease in expression of the normal splice pattern. The majority of studies examining splicing in CLCN1 have been performed using mouse Clcn1, as have investigations into the activation and suppression of normal splicing variant expression by MBNL1-3 and CELF3–6, respectively. In contrast, examinations of human CLCN1 have been less common due to the greater complexity of splicing patterns. Here, we constructed a minigene containing CLCN1 exons 5–7 and established a novel assay system to quantify the expression of the normal splicing variant of CLCN1 using real-time RT-PCR. Antisense oligonucleotides could promote normal CLCN1 alternative splicing but the effective sequence was different from that of Clcn1. This result differs from previous reports using Clcn1, highlighting the effect of differences in splicing patterns between mice and humans.     

Mediator subunits MED1 and MED24 cooperatively contribute to pubertal mammary gland development and growth of breast carcinoma cells

The Mediator subunit MED1 is essential for mammary gland development and lactation, whose contribution through direct interaction with estrogen receptors (ERs) is restricted to involvement in pubertal mammary gland development and luminal cell differentiation. Here, we provide evidence that the MED24-containing submodule of Mediator functionally communicates specifically with MED1 in pubertal mammary gland development. Mammary glands from MED1/MED24 double heterozygous knockout mice showed profound retardation in ductal branching during puberty, while single haploinsufficient glands developed normally. DNA synthesis of both luminal and basal cells were impaired in double mutant mice, and the expression of ER-targeted genes encoding E2F1 and cyclin D1, which promote progression through the G(1)/S phase of the cell cycle, was attenuated. Luciferase reporter assays employing double mutant mouse embryonic fibroblasts showed selective impairment in ER functions. Various breast carcinoma cell lines expressed abundant amounts of MED1, MED24, and MED30, and attenuated expression of MED1 and MED24 in breast carcinoma cells led to attenuated DNA synthesis and growth. These results indicate functional communications between the MED1 subunit and the MED24-containing submodule that mediate estrogen receptor functions and growth of both normal mammary epithelial cells and breast carcinoma cells.     

Indomethacin induction of metamorphosis from the asexual stage to sexual stage in the moon jellyfish, Aurelia aurita

We found while screening a chemical library that indomethacin, an inhibitor of prostaglandin biosynthesis, induced strobilation (metamorphosis from the asexual to sexual stage) in the moon jellyfish, Aurelia aurita. Indomethacin initiated strobilation in a dose-dependent manner, but was not involved in the progression of strobilation. Pharmacological experiments suggested that indomethacin could induce strobilation independently of prostaglandin biosynthesis.