Increasing evidence has demonstrated that emotional states and intestinal conditions are inter-connected in so-called “brain–gut interactions.” Indeed, many psychiatric disorders are accompanied by ...gastrointestinal symptoms, such as the irritable bowel syndrome (IBS). However, the functional connection remains elusive, partly because there are few useful experimental animal models. Here, we focused on a highly validated animal model of stress-induced psychiatric disorders, such as depression, known as the chronic vicarious social defeat stress (cVSDS) model mice, which we prepared using exposure to repeated psychological stress, thereafter examining their intestinal conditions. In the charcoal meal test and the capsaicin-induced hyperalgesia test, cVSDS model mice showed a significantly higher intestinal transit ratio and increased visceral pain-related behaviors, respectively. These changes persisted over one month after the stress session. On the other hand, the pathological evaluations of the histological and inflammatory scores of naive and cVSDS model mice did not differ. Furthermore, keishikashakuyakuto—a kampo medicine clinically used for the treatment of IBS—normalized the intestinal motility change in cVSDS model mice. Our results indicate that cVSDS model mice present IBS-like symptoms such as chronic intestinal peristaltic changes and abdominal hyperalgesia without organic lesion. We therefore propose the cVSDS paradigm as a novel animal model of IBS with wide validity, elucidating the correlation between depressive states and intestinal abnormalities.
Disulfiram is an FDA approved drug for the treatment of alcoholism. The drug acts by inhibiting aldehyde dehydrogenase, an enzyme essential to alcohol metabolism. However, a recent study has ...demonstrated that disulfiram also potently inhibits the cytoplasmic protein FROUNT, a common regulator of chemokine receptor CCR2 and CCR5 signaling. Several studies have reported that chemokine receptors are associated with the regulation of emotional behaviors in rodents, such as anxiety. Therefore, this study was performed to clarify the effect of disulfiram on emotional behavior in rodents. The anxiolytic-like effects of disulfiram were investigated using an elevated plus-maze (EPM) test, a typical screening model for anxiolytics. Disulfiram (40 or 80 mg/kg) significantly increased the amount of time spent in the open arms of the maze and the number of open arm entries without affecting the total open arms entries. Similar results were obtained in mice treated with a selective FROUNT inhibitor, disulfiram-41 (10 mg/kg). These disulfiram-associated behavioral changes were similar to those observed following treatment with the benzodiazepine anxiolytic diazepam (1.5 mg/kg). Moreover, disulfiram (40 mg/kg) significantly and completely attenuated increased extracellular glutamate levels in the prelimbic-prefrontal cortex (PL-PFC) during stress exposure on the elevated open-platform. However, no effect in the EPM test was seen following administration of the selective aldehyde dehydrogenase inhibitor cyanamide (40 mg/kg). In contrast to diazepam, disulfiram caused no sedation effects in the open-field, coordination disorder on a rotarod, or amnesia in a Y-maze. This is the first report suggesting that disulfiram produces anxiolytic-like effects in rodents. We found that the presynaptic inhibitory effects on glutaminergic neurons in the PL-PFC may be involved in its underlying mechanism. Disulfiram could therefore be an effective and novel anxiolytic drug that does not produce benzodiazepine-related adverse effects, such as amnesia, coordination disorder, or sedation, as found with diazepam. We propose that the inhibitory activity of disulfiram against FROUNT function provides an effective therapeutic option in anxiety.
Recent study has demonstrated that anti-alcoholism drug disulfiram (DSF) inhibits chemokine receptor-mediated migration signals. Several studies have reported that the chemokine receptors are ...associated with emotion regulation. Therefore, this study was performed to clarify the effect of DSF on emotional behavior in rodents.Male ICR mice were used. In the elevated plus-maze test, a screening model for anxiolytics, DSF (40 mg/kg, i.p.) significantly produced the increases in the percentage of time spent on the open-arms without any effects on the total open arms entries. These behavioral changes were similar to that observed for the benzodiazepine anxiolytics diazepam (1.5 mg/kg, s.c.). In contrast to diazepam, DSF produced no effects on the spontaneous locomotor activity in mice. On the other hand, in the rotarod test, diazepam significantly increased the number of falls, suggesting the coordination disorder, whereas DSF produced no effects. Furthermore, DSF decreased noradrenaline content and increased dopamine content in mice amygdala.This is the first report suggesting that DSF produced the anxiolytic-like effects in rodents. We proposed that DSF could be an effective novel anxiolytic drug without the coordination disorder found in diazepam, and that the monoamine content changes in amygdala may be involved in its underlying mechanism.
Recent study has demonstrated that anti-alcoholism drug disulfiram (DSF) inhibits chemokine receptor-mediated migration signals. Several studies have reported that the chemokine receptors are ...associated with emotion regulation. Therefore, this study was performed to clarify the effect of DSF on emotional behavior in rodents.Male ICR mice were used. In the elevated plus-maze test, a screening model for anxiolytics, DSF (40 mg/kg, i.p.) significantly produced the increases in the percentage of time spent on the open-arms without any effects on the total open arms entries. These behavioral changes were similar to that observed for the benzodiazepine anxiolytics diazepam (1.5 mg/kg, s.c.). In contrast to diazepam, DSF produced no effects on the spontaneous locomotor activity in mice. On the other hand, in the rotarod test, diazepam significantly increased the number of falls, suggesting the coordination disorder, whereas DSF produced no effects. Furthermore, DSF decreased noradrenaline content and increased dopamine content in mice amygdala.This is the first report suggesting that DSF produced the anxiolytic-like effects in rodents. We proposed that DSF could be an effective novel anxiolytic drug without the coordination disorder found in diazepam, and that the monoamine content changes in amygdala may be involved in its underlying mechanism.
NEDD8/Rub1 is a ubiquitin (Ub)-like molecule that covalently ligates to target proteins through an enzymatic cascade analogous to ubiquitylation. This modifier is known to target all cullin (Cul) ...family proteins. The latter are essential components of Skp1/Cul-1/F-box protein (SCF)-like Ub ligase complexes, which play critical roles in Ub-mediated proteolysis. To determine the role of the NEDD8 system in mammals, we generated mice deficient in Uba3 gene that encodes a catalytic subunit of NEDD8-activating enzyme. Uba3-/-mice died in utero at the periimplantation stage. Mutant embryos showed selective apoptosis of the inner cell mass but not of trophoblastic cells. However, the mutant trophoblastic cells could not enter the S phase of the endoreduplication cycle. This cell cycle arrest was accompanied with aberrant expression of cyclin E and p57Kip2. These results suggested that the NEDD8 system is essential for both mitotic and the endoreduplicative cell cycle progression. β-Catenin, a mediator of the Wnt/wingless signaling pathway, which degrades continuously in the cytoplasm through SCF Ub ligase, was also accumulated in the Uba3-/-cytoplasm and nucleus. Thus, the NEDD8 system is essential for the regulation of protein degradation pathways involved in cell cycle progression and morphogenesis, possibly through the function of the Cul family proteins.
We present the results of wide-field deep JHK imaging of the SSA22 held using the MOIRCS instrument equipped with the Subaru telescope. The observed field is 112 arcmin super(2) in area, which covers ...the z = 3.1 protocluster characterized by the overdensities of Ly alpha emitters (LAEs) and Ly alpha blobs (LABs). The 5sigma limiting magnitude is K sub(AB) = 24.3. We extract the potential protocluster members from the K-selected sample by using the multi-band photometric-redshift selection as well as the simple color cut for distant red galaxies (DRGs; J - K sub(AB) > 1.4). The surface number density of DRGs in our observed fields shows clear excess compared with those in the blank fields, and the location of the densest area whose projected overdensity is twice the average coincides with the large-scale density peak of LAEs. We also found that K-band counterparts with z sub(phot) Asymptotically = to 3.1 are detected for 75% (15/20) of the LABs within their Ly alpha halo, and the 40% (8/20) of LABs have multiple components, which gives a direct evidence of the hierarchical multiple merging in galaxy formation. The stellar mass of LABs correlates with their luminosity, isophotal area, and the Ly alpha velocity widths, implying that the physical scale and the dynamical motion of Ly alpha emission are closely related to their previous star formation activities. Highly dust-obscured galaxies such as hyper extremely red objects (J - K sub(AB) > 2.1) and plausible K-band counterparts of submillimeter sources are also populated in the high-density region.
NEDD8/Rub1 is a ubiquitin (Ub)‐like post‐translational modifier that is covalently linked to cullin (Cul)‐family proteins in a manner analogous to ubiquitylation. NEDD8 is known to enhance the ...ubiquitylating activity of the SCF complex (composed of Skp1, Cul‐1, ROC1 and F‐box protein), but the mechanistic role is largely unknown. Using an in vitro reconstituted system, we report here that NEDD8 modification of Cul‐1 enhances recruitment of Ub‐conjugating enzyme Ubc4 (E2) to the SCF complex (E3). This recruitment requires thioester linkage of Ub to Ubc4. Our findings indicate that the NEDD8‐modifying system accelerates the formation of the E2–E3 complex, which stimulates protein polyubiquitylation.
We present the results of deep near-infrared imaging observations of the
$z=3.1$
proto-cluster region in the SSA 22a field taken by MOIRCS mounted on the Subaru Telescope. We observed a 21.7 arcmin
...$^2$
field to depths of
$J=$
24.5,
$H=$
24.3, and
$K=$
23.9 (5
$\sigma$
). We examined the distribution of the
$K$
-selected galaxies at
$z \sim 3$
by using a simple color cut for distant red galaxies (DRGs) as well as a photometric-redshift selection technique. The marginal density excess of DRGs and the photo-
$z$
selected objects were found around the two most luminous Ly
$\alpha$
blobs (LABs). We investigated the correlation between the
$K$
-selected objects and the LABs, and found that several galaxies with stellar mass,
$M_* = 10^{9}$
–
$10^{11} M_\odot$
, exist in the vicinity of LABs, especially around the two most luminous ones. We also found that 7 of the 8LABs in the field have plausible
$K_{\rm s}$
-band counterparts, and the sum of the stellar mass possibly associated with LABs correlates with their luminosity and surface brightness, which implies that the origin of Ly
$\alpha$
emission may be closely correlated with their previous star-formation phenomena.
We found previously that overexpression of an F-box protein βTrCP1 and the structurally related βTrCP2 augments ubiquitination of phosphorylated IκBα (pIκBα) induced by tumor necrosis factor-α ...(TNF-α), but the relationship of the two homologous βTrCP proteins remains unknown. Herein we reveal that deletion mutants of βTrCP1 and βTrCP2 lacking the F-box domain suppressed ubiquitination and destruction of pIκBα as well as transcriptional activation of NF-κB. The ectopically expressed βTrCP1 and βTrCP2 formed both homodimer and heterodimer complexes without displaying the trimer complex. Dimerization of βTrCP1 and/or βTrCP2 takes place at their conserved NH2-terminal regions, termed a “D-domain” (for dimerization domain), located upstream of the F-box domain. The D-domain was necessary and sufficient for the dimer formation. Intriguingly, the βTrCP homodimer, but not the heterodimer, was selectively recruited to pIκBα induced by TNF-α. These results indicate that not only βTrCP1 but also βTrCP2 participates in the ubiquitination-dependent destruction of IκBα by forming SCFβTrCP1-βTrCP1 and SCFβTrCP2-βTrCP2 ubiquitin-ligase complexes.
Destruction of the transcriptional inhibitor IκB by the ubiquitin (Ub) system is required for signal-dependent activation of the multifunctional transcriptional factor NF-κB, but details of this ...ubiquitination are largely unknown. We report here that the IκBα-ubiquitin ligase (IκBα-E3) is an SCF-like complex containing Skp1, cullin-1, and two homologous F-box/WD40-repeat proteins, βTrCP1 and βTrCP2. Intriguingly, all these components are cooperatively recruited to bind to a phosphorylated IκBα (pIκBα) produced by tumor necrosis factor-α (TNF-α) stimulation. IκBα-E3 bound to pIκBα catalyzedin vitroubiquitination of pIκBα in the presence of ATP, Ub, and E1-activating and E2-conjugating enzymes. Forced expression of βTrCP1 and βTrCP2 resulted in dramatic augmentation of thein vitropolyubiquitination activity of IκBα-E3. These results indicate that the long-sought IκBα-E3 is an SCF-like complex consisting of multiple proteins which are coordinately assembled during phosphorylation of IκBα in response to external signals.
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