Bis(2,3,5-triphenyl­tetra­zolium) tetra­thio­cyanato­cobaltate(II)

The title compound, (C19H15N4)2[Co(NCS)4], has two crystallographycally different molecules of bis­(2,3,5-triphenyl­tetra­zolium) tetra­thio­cyanatecobaltate in the asymmetric unit. There are only minor geometric differences between them. Each cobalt(II) ion is coordinated by the N atoms of four NCS anions, showing the magnitude of the magnetic moment expected from the NCS− crystal field strength

Regulation of cyclin D1 expression and cell cycle progression by mitogen-activated protein kinase cascade

Regulation of cyclin D1 expression and cell cycle progression by mitogen-activated protein kinase cascade. Mitogen-activated protein kinases (MAPKs) have been shown to play an important role in transducing extracellular signals into cellular responses. The classic MAPK pathway is commonly activated by growth factors and has been shown to play a crucial role in cell proliferation. Transforming growth factor-β (TGF-β)–activating kinase-1 (TAK1) is a novel MAPK kinase kinase that is reported to stimulate the MKK6-p38K pathway. To elucidate the functional roles of the TAK1 pathway, we transfected its constitutive active form (TAKdN) and negative form (TAKK63W) to LLC-PK1 cells. TAKdN stimulated MKK6 phosphorylation and p38K activity and inhibited the percentages of the S and G2/M phases. TAKK63W, the constitutive negative form, reduced TGF-β–stimulated MKK6 phosphorylation and p38K activity and increased the percentages of the S and G2/M phases. The cyclin D1 protein level is reduced by the TAK1 pathway. We also examined the effects of the TAK1 pathway on cyclin D1 promoter-luciferase assay. The overexpression of TAKdN or p38K inhibited cyclin D1 promoter activity. In contrast, overexpression of the active form of MKK1, the classic MAPK-activator, MKK1 increased cyclin D1 promoter activity and protein level, as well as the percentages of S and G2/M phases

TGF-βbgr-activating kinase-1 inhibits cell cycle and expression of cyclin D1 and A in LLC-PK1 cells

TGF-βbgr-activating kinase-1 inhibits cell cycle and expression of cyclin D1 and A in LLC-PK1 cells.BackgroundTransforming growth factor-βbgr (TGF-βbgr) is known to play an important role in the pathophysiology of renal tubular disease. Researchers have recently identified a novel mitogen-activated protein kinase kinase kinase (MAPKKK), TAK (TGF-βbgr activated kinase)1, which stimulates the MKK3/6-p38K pathway. The purpose of our study was to investigate the functional role of the TAK1-MKK3/6-p38K pathway and classical MAPK cascades in the progression of the cell cycle in renal tubular cells.MethodsThe constitutive active form and negative form of TAK1 (TAK1dN and TAK1K63W, respectively), and active and negative forms of the p42/44 MAPK-activator, MKK1 (S222E and S222A, respectively) were transfected to LLC-PK1 cells. Western blot analyses and promoter-luciferase assay of cyclins D1, D2, D3, E, and A were performed, and cell cycle progression was analyzed by FACS scan.ResultsTAK1dN stimulated MKK6 and p38K activity and inhibited the percentage of the S and G2/M phases. TAK1K63 W inhibited TGF-βbgr-stimulated MKK6 and p38K activity. Cyclin D1 and cyclin A protein levels and promoter activities were negatively regulated by TAK1dN. In contrast, overexpression of the active form of p42/44 MAPK-activator, MKK1, increased cyclin D1 and A promoter activity and protein levels.ConclusionThe growth-inhibitory effects of TGF-βbgr are at least partially mediated by the TAK1-MKK6-p38K pathway. Cyclin D1 and A promoter activity and cell cycle progression in renal tubular cells are negatively regulated by the TAK1-MKK6-p38K pathway and positively regulated by the MKK1-p42/44MAPK pathway

Activated STAT1 suppresses proliferation of cultured rat mesangial cells

Activated STAT1 suppresses proliferation of cultured rat mesangial cells.BackgroundJAK-STAT signaling has been shown to promote development and proliferation in lymphopoietic and hematopoietic lineages. We investigated the effect of activated STAT1 on mesangial cell proliferation.MethodsRat mesangial cells of primary culture (rMCs) were used in the following experiments: (1) Whole cell lysates were immunoblotted against JAK1 and JAK2. (2) Whole cell lysates and nuclear proteins were extracted from rMCs with or without treatment with interferon-γ, and immunoblotting was performed against both STAT1 and tyrosine (701)-phosphorylated STAT1. (3) rMCs and rMCs electroporated with either wild-type STAT1, mutated STAT1, or antibody against STAT1 were incubated with interferon-γ for 20 hours, followed by a further incubation with [3H]-thymidine for four hours.ResultsJAK1, JAK2, and STAT1 were detected in whole cell lysates, suggesting that JAK-STAT signaling could be activated by interferon-γ (INF-γ). Using an antibody specific for tyrosine-phosphorylated STAT1, we detected signal in the INF-γ–treated nuclear extracts, which showed translocation of phosphorylated STAT1 to the nucleus. [3H]-thymidine incorporation in the presence of INF-γ was significantly lower than that of control in a dose-dependent manner. The introduction of wild-type STAT1 enhanced the effect of interferon-γ and decreased [3H]-thymidine incorporation, whereas tyrosine-mutated (Y701F) STAT1 and SH2 domain (R602T)-mutated STAT1 reversed INF-γ–induced suppression of [3H]-thymidine incorporation. Electroinjected antibody against STAT1 increased [3H]-thymidine incorporation upon stimulation with INF-γ.ConclusionSTAT1 activated by interferon-γ suppresses mesangial cell proliferation

Quantification of Hepatic Iron Concentration in Chronic Viral Hepatitis: Usefulness of T2-weighted Single-Shot Spin-Echo Echo-Planar MR Imaging

Objective: To investigate the usefulness of single-shot spin-echo echo-planar imaging (SSEPI) sequence for quantifying mild degree of hepatic iron stores in patients with viral hepatitis. Methods: This retrospective study included 34 patients with chronic viral hepatitis/cirrhosis who had undergone histological investigation and magnetic resonance imaging with T2-weighted gradient-recalled echo sequence (T2-GRE) and diffusion-weighted SSEPI sequence with b-factors of 0 s/mm 2 (T2-EPI), 500 s/mm 2 (DW-EPI-500), and 1000 s/mm 2 (DW-EPI-1000). The correlation between the liver-to-muscle signal intensity ratio, which was generated by regions of interest placed in the liver and paraspinous muscles of each sequence image, and the hepatic iron concentration (mmol/g dry liver), which was assessed by spectrophotometry, was analyzed by linear regression using a spline model. Akaike information criterion (AIC) was used to select the optimal model. Results: Mean 6 standard deviation of the hepatic iron concentration quantified by spectrophotometry was 24.6616.

Inhibition of Rho-associated coiled-coil containing protein kinase enhances the activation of epidermal growth factor receptor in pancreatic cancer cells

<p>Abstract</p> <p>Background</p> <p>Rho-associated coiled-coil containing protein kinase (Rho-kinase/ROCK) is involved in various cellular functions including cell proliferation, and is generally considered to be oncogenic, while some studies show that ROCK functions as a negative regulator of cancer progression. As a result, the precise role of ROCK remains controversial. We have previously reported that Rho-kinase/ROCK negatively regulates epidermal growth factor (EGF)-induced cell proliferation in SW480 colon cancer cells. In the present study, we investigated the role of ROCK in EGF receptor (EGFR) signaling in the pancreatic cancer cell lines, Panc1, KP3 and AsPc1.</p> <p>Results</p> <p>In these cells, Y27632, a specific ROCK inhibitor, enhanced EGF-induced BrdU incorporation. The blockade of EGF stimulation utilizing anti-EGFR-neutralizing antibodies suppressed Panc1 cell proliferation. EGF induced RhoA activity, as well as the phosphorylation of cofilin and myosin light chain (MLC), both targets of ROCK signaling, and Y27632 suppressed both of these processes, indicating that the phosphorylation of cofilin and MLC by EGF occurs through ROCK in Panc1 cells. EGF-induced phosphorylation of EGFR at tyrosine residues was augmented when the cells were pretreated with Y27632 or were subjected to gene silencing using ROCK-siRNA. We also obtained similar results using transforming growth factor-α. In addition, EGF-induced phosphorylation of p44/p42 mitogen-activated protein kinase and Akt were also enhanced by Y27632 or ROCK-siRNA. Moreover, an immunofluorescence microscope study revealed that pretreatment with Y27632 delayed EGF-induced internalization of EGFR. Taken together, these data indicate that ROCK functions to switch off EGFR signaling by promoting the internalization of the EGFR.</p> <p>Conclusions</p> <p>While EGF first stimulates the activation of the EGFR and subsequently increases cancer cell proliferation, EGF concurrently induces the activation of ROCK, which then turns off the activated EGFR pathway via a negative feedback system.</p

Social problems in daily life of patients with dementia

AIM: Most patients with dementia frequently encounter various problems in their daily lives. Those troubles embarrass both the patients and their families, and cause problems for society. However, there have been few scientific reports on the difficulties in the daily life of patients with dementia. Therefore, we tried to clarify the frequency and characteristics of troubles experienced by patients with dementia. METHODS: Seven medical centers treating dementia patients in Okayama Prefecture, Japan, participated in this survey. A total of 737 patients were placed in one of the three groups: a dementia group (n = 478), a mild cognitive impairment group (n = 199) and a control group (n = 60). The frequency of 13 difficulties was scored for each patient. RESULTS: Among normal participants, no person caused these problems once a year or more frequently. "Massive, recurrent buying" and "acts that risk causing a fire" were reported once a year or more for >10% of mild cognitive impairment patients. "Troubles with wealth management" and "troubles with money management" were the most frequent problems of dementia patients. CONCLUSIONS: Several problems are already sometimes encountered in patients with mild cognitive impairment. It would be useful to know which social difficulties are often seen in dementia patients in order to protect the safety of the patients. It is always difficult to balance respecting the autonomy of dementia patients and ensuring their safely

Manipulation of charge carrier flow in Bi₄NbO₈Cl nanoplate photocatalyst with metal loading

Separation of photoexcited charge carriers in semiconductors is important for efficient solar energy conversion and yet the control strategies and underlying mechanisms are not fully established. Although layered compounds have been widely studied as photocatalysts, spatial separation between oxidation and reduction reaction sites is a challenging issue due to the parallel flow of photoexcited carriers along the layers. Here we demonstrate orthogonal carrier flow in layered Bi₄NbO₈Cl by depositing a Rh cocatalyst at the edges of nanoplates, resulting in spatial charge separation and significant enhancement of the photocatalytic activity. Combined experimental and theoretical studies revealed that lighter photogenerated electrons, due to a greater in-plane dispersion of the conduction band (vs. valence band), can travel along the plane and are readily trapped by the cocatalyst, whereas the remaining holes hop perpendicular to the plane because of the anisotropic crystal geometry. Our results propose manipulating carrier flow via cocatalyst deposition to achieve desirable carrier dynamics for photocatalytic reactions in layered compounds