327 research outputs found
Massive gravitons dark matter scenario revisited
We reexamine the massive graviton dark matter scenario (MGCDM) which was
recently considered as an alternative to dark energy models. When introducing
the native and effective equations of state (EoS), it is shown that there is no
phantom phase in the evolution toward the far past. Also we show that the past
accelerating phase arises from the interaction between massive graviton and
cold dark matter.Comment: 13 pages, 6 figure
Holographic interacting dark energy in the braneworld cosmology
We investigate a model of brane cosmology to find a unified description of
the radiation-matter-dark energy universe. It is of the interacting holographic
dark energy with a bulk-holographic matter . This is a five-dimensional
cold dark matter, which plays a role of radiation on the brane. Using the
effective equations of state instead of the
native equations of state , we show that this model
cannot accommodate any transition from the dark energy with to the phantom regime . Furthermore, the case of interaction between cold dark matter and
five dimensional cold dark matter is considered for completeness. Here we find
that the redshift of matter-radiation equality is the same order
as . Finally, we obtain
a general decay rate which is suitable for describing all interactions
including the interaction between holographic dark energy and cold dark matter.Comment: 17 pages, 4 figure
The involvement of AMPK/GSK3-beta signals in the control of metastasis and proliferation in hepato-carcinoma cells treated with anthocyanins extracted from Korea wild berry Meoru
BACKGROUND: Activation of the Wnt pathway is known to promote tumorigenesis and tumor metastasis, and targeting Wnt pathway inhibition has emerged as an attractive approach for controlling tumor invasion and metastasis. The major pathway for inhibiting Wnt is through the degradation of β-catenin by the GSK3-beta/CK1/Axin/APC complex. It was found that Hep3B hepato-carcinoma cells respond to anthocyanins through GSK3-beta-induced suppression of beta-catenin; however, they cannot dephosphorylate GSK3-beta without AMPK activation. METHODS: We tested the effects of anthocyanins on proliferation and apoptosis by MTT and Annexin V-PI staining in vitro. Mouse xenograft models of hepato-carcinomas were established by inoculation with Hep3B cells, and mice were injected with 50 mg/kg/ml of anthocyanins. In addition, protein levels of p-GSK3-beta, beta-catenin, p-AMPK, MMP-9, VEGF, and Ang-1 were also analyzed using western blot. RESULTS: Anthocyanins decrease phospho-GSK3-beta and beta-catenin expression in an in vivo tumor xenograft model, increase AMPK activity in this model, and inhibit cell migration and invasion, possibly by inhibiting MMP-2 (in vitro) and the panendothelial marker, CD31 (in vivo). To elucidate the role of the GSK3-beta/beta-catenin pathway in cancer control, we conditionally inactivated this pathway, using activated AMPK for inhibition. Further, we showed that AMPK siRNA treatment abrogated the ability of anthocyanins to control cell proliferation and metastatic potential, and Compound C, an AMPK inhibitor, could not restore GSK3-beta regulation, as exhibited by anthocyanins in Hep3B cells. CONCLUSION: These observations imply that the AMPK-mediated GSK3-beta/beta-catenin circuit plays crucial roles in inhibiting cancer cell proliferation and metastasis in anthocyanin-treated hepato-carcinoma cells of Meoru origin
Canine adipose tissue-derived MSCs engineered with mRNA to overexpress TSG-6 and enhance the anti-inflammatory effects in canine macrophages
BackgroundMesenchymal stem cells (MSCs) are useful agents in the treatment of various inflammatory diseases. The immunomodulatory effects of MSCs are largely related to their secretory properties. mRNA engineering emerged as a safe alternative to enhance the secretory function of MSCs. Optimization of the untranslated region (UTR) sequence is important for enhancing the translational efficiency of exogenous mRNAs. However, research on the optimization of UTR in canine MSCs has not yet been conducted.ObjectivesWe aimed to identify the UTR sequence related to the expression efficiency of in vitro transcription (IVT) mRNA in canine MSCs and investigate whether mRNA-engineered MSCs that overexpress TSG-6 exhibit enhanced anti-inflammatory effects.MethodsCanine adipose tissue-derived (cAT)-MSCs were transfected with green fluorescence protein (GFP) mRNA with three different UTRs: canine hemoglobin subunit alpha-like 1 (HBA1), HBA2, and hemoglobin subunit beta-like (HBB). The translation efficacy of each mRNA was evaluated using relative fluorescence. TSG-6 mRNA was produced with the UTR optimized according to relative fluorescence results. cAT-MSCs were transfected with TSG-6 mRNA (MSCTSG-6), and TSG-6 expression was analyzed using real-time quantitative PCR, ELISA, and western blotting. To evaluate the anti-inflammatory effects of MSCsTSG-6, DH82 cells were co-cultured with MSCsTSG-6 or treated with dexamethasone, and changes in the expression of inflammatory cytokines were analyzed using qPCR.ResultsThe highest fluorescence level was observed in the HBA1 UTR at 24 h post-transfection. TSG-6 mRNA transfection yielded high levels of TSG-6 in the cAT-MSCs. In DH82 cells co-cultured with MSCsTSG-6, the expression of inflammatory cytokines decreased compared to that in co-culturing with naïve MSCs and dexamethasone treatment.ConclusionsOptimization of the HBA1 UTR improved the translation efficiency of IVT mRNA in canine MSCs. cAT-MSCs engineered with TSG-6 mRNA effectively enhanced the anti-inflammatory effects of the MSCs when co-cultured with LPS-activated DH82 cells
The occurrence of coronary artery lesions in Kawasaki disease based on C-reactive protein levels: a retrospective cohort study
Background
This study aimed to assess the occurrence of coronary artery lesions (CAL) in patients with Kawasaki disease (KD) according to serum C-reactive protein (CRP) levels.
Methods
This retrospective analysis was based on the nationwide survey of KD conducted in the Republic of Korea between 2015 and 2017. We enrolled 9131 patients and defined low (< 3 mg/dL) and high (≥3 mg/dL) CRP groups. Demographic data, clinical characteristics, z-scores, and scores based on the Japanese criteria for CAL were compared between the two groups. Logistic regression analysis was used to identify CAL risk factors.
Results
The low CRP group accounted for 23% of patients. The mean age at diagnosis was higher in high CRP group compared to the low CRP group (34.4 ± 24.9 vs 31.7 ± 24.8 months, p < 0.001). Fever duration before treatment was not significantly different between the two groups (5.1 ± 1.7 days vs. 5.2 ± 2.1 days; p = 0.206). A non-response to intravenous immunoglobulin treatment was found in 1377 patients (20.1%) and 225 patients (11.7%) in the high and low CRP groups, respectively (p < 0.001). CAL were found in 12.9 and 18.3% of the high and low CRP patients, respectively (p < 0.001), based on z-scores; and in 9.9 and 12.5%, respectively (p = 0.001), based on the Japanese criteria in the acute phase. The giant coronary artery aneurysm occurrence ratio was similar between groups (p = 1.0).
Conclusions
CAL occurred in patients with both high and low CRP. Therefore, patients with KD should be carefully monitored regardless of their CRP levels
On the Ricci dark energy model
We study the Ricci dark energy model (RDE) which was introduced as an
alternative to the holographic dark energy model. We point out that an
accelerating phase of the RDE is that of a constant dark energy model. This
implies that the RDE may not be a new model of explaining the present
accelerating universe.Comment: 8 page
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