The circadian clock in mammalian cells is cell-autonomously generated during the cellular differentiation process, but the underlying mechanisms are not understood. Here we show that perturbation of the transcriptional program by constitutive expression of transcription factor c-Myc and DNA methyltransferase 1 (Dnmt1) ablation disrupts the differentiation-coupled emergence of the clock from mouse ESCs. Using these model ESCs, 484 genes are identified by global gene expression analysis as factors correlated with differentiation-coupled circadian clock development. Among them, we find the misregulation of Kpna2 (Importin-α2) during the differentiation of the c-Myc-overexpressed and Dnmt1 −/− ESCs, in which sustained cytoplasmic accumulation of PER proteins is observed. Moreover, constitutive expression of Kpna2 during the differentiation culture of ESCs significantly impairs clock development, and KPNA2 facilitates cytoplasmic localization of PER1/2. These results suggest that the programmed gene expression network regulates the differentiation-coupled circadian clock development in mammalian cells, at least in part via posttranscriptional regulation of clock proteins.T he circadian clock is an intrinsic time-keeping system that regulates essential physiological functions such as sleep/wake cycles, body temperature, and metabolism (1-3). In the mammalian clock system the central pacemaker resides in the suprachiasmatic nucleus of the hypothalamus, coordinating cell-autonomous molecular oscillators throughout the body to perform tissue-specific functions. The molecular oscillator consists of transcriptional/ translational feedback loops of clock genes. Two transcription factors, CLOCK and BMAL1, heterodimerize and transactivate core clock genes such as the Period (Per1, 2, 3), Cryptochrome (Cry1, 2), and Rev-Erbα genes via E-box regulatory elements. PER and CRY proteins, in turn, translocate into the nucleus to suppress CLOCK/BMAL1 activity, leading to cyclic expression of these clock genes (4-9). Furthermore, REV-ERBα negatively regulates Bmal1 transcription via the RORE promoter element, thus driving antiphasic expression patterns of Bmal1 (10, 11).Despite uncovering the emergence of the circadian rhythms that occur during development (12-14), the precise mechanism of circadian clock development in mammalian cells remains unclear. Recently it has been found that pluripotent ES cells (ESCs) do not display discernible circadian molecular oscillations, whereas in vitro-differentiated ESCs displayed robust circadian oscillations of reporter expression (15-17). Moreover, we also have shown that circadian oscillations were abolished when differentiated cells were reprogrammed to regain pluripotency by expression of reprogramming factors (Oct3/4, Sox2, Klf4, and c-Myc) (15). These results suggested that the emergence of the cell-autonomous circadian oscillator is coupled with cellular differentiation. Cellular differentiation, as well as reprogramming, results in global alterations of the transcriptional program and epi...
Abstract. It remains to be clarified whether adoptive cellular therapy (ACT) in patients with advanced cancer, in whom strong immunosuppression and immune-escape mechanisms are established, has the potential to alter cytokine secretion from blood cells and affect the number of regulatory T cells (Tregs). In this study, the secretion of cytokines from peripheral blood cells and the number of peripheral blood Tregs were analyzed before and after ACT. Blood samples were collected from 109 consecutive cancer patients who received ACT, which consisted of anti-CD3 stimulated lymphokineactivated killer cells. For testing immune function, venous blood was obtained from patients before the start of therapy and after they had received 4 cycles of ACT. Of the 109 patients, 76 received ACT four times or more. All 109 blood samples at baseline and 76 follow-up samples were available. The secretion ability of various cytokines from peripheral blood cells was measured, as well as the number of peripheral blood Tregs. We found that the secretion ability of interferon (IFN)-γ and tumor necrosis factor (TNF)-α was enhanced significantly after treatment, while the number of Tregs and the ratio of Treg to CD4 was significantly decreased. Overall survival in patients with increased IFN-γ and TNF-α secretion after ACT was significantly longer. These findings suggest a potential therapeutic role for ACT in cancer immunotherapy.
Aim. Chronic gastritis was assessed serologically, endoscopically and histologically to identify correlations between these methods. Methods. Subjects comprised 319 patients who had provided informed consent. Serological assessment of chronic gastritis was based on the pepsinogen test method. Endoscopic gastritis and histological gastritis were assessed and scored according to the Kimura-Takemoto classification system and the updated Sydney classification system respectively, and correlations between these three methods were studied. Results. Pepsinogen I/II ratio showed a significant correlation to the extent of mononuclear cell infiltration of the gastric corpus. When histological gastritis was divided, on the basis of the distribution of mononuclear cell infiltration, into gastritis limited to the antrum and corpus gastritis, these types were distinguished with high accuracy using a pepsinogen I/II ratio of 3 as the cutoff. A good correlation was also seen between pepsinogen I/II ratio and development of atrophy in endoscopic gastritis, where groups with and without advanced atrophy were also distinguished with high accuracy using a cutoff value of 3. Conclusion. Significant correlations exist between serum pepsinogen levels, endoscopic gastritis, and histological gastritis. Pepsinogen I/II ratio allows prediction of the existence of endoscopic gastritis and histological gastritis, or the extent of their development, with high accuracy.
<b><i>Introduction:</i></b> Sessile serrated lesions (SSLs) have malignant potential for colorectal cancer in the serrated pathway. Selective endoscopic resection of SSLs would reduce medical costs and procedure-related accidents, but the accurate endoscopic differentiation of SSLs from hyperplastic polyps (HPs) is challenging. To explore the differential diagnostic performance of magnifying colonoscopy in distinguishing SSLs from HPs, we conducted a multicenter prospective validation study in clinical practice. <b><i>Methods:</i></b> Considering the rarity of diminutive SSLs, all lesions ≥6 mm that were detected during colonoscopy and diagnosed as type 1 based on the Japan narrow-band imaging expert team (JNET) classification were included in this study. Twenty expert endoscopists were asked to differentiate between SSLs and HPs with high or low confidence level after conventional and magnifying NBI observation. To examine the validity of selective endoscopic resection of SSLs using magnifying colonoscopy in clinical practice, we calculated the sensitivity of endoscopic diagnosis of SSLs with histopathological findings as comparable reference. <b><i>Results:</i></b> A total of 217 JNET type 1 lesions from 162 patients were analyzed, and 114 lesions were diagnosed with high confidence. The sensitivity of magnifying colonoscopy in detecting SSLs was 79.8% (95% confidence interval [CI]: 74.7–84.4%) overall, and 82.4% (95% CI: 76.1–87.7%) in the high-confidence group. These results showed that the sensitivity of this study was not high enough, even limited in the high-confidence group. <b><i>Conclusions:</i></b> Accurate differential diagnosis of SSLs and HPs using magnifying colonoscopy was challenging even for experts. JNET type 1 lesions ≥6 mm are recommended to be resected because selective endoscopic resection has a disadvantage of leaving approximately 20% of SSLs on site.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.