A Method for Culturing Mouse Whisker Follicles to Study Circadian Rhythms ex vivo

Ex vivo tissue-culture experiments are often performed in the field of circadian biology. The major aim of these experiments is to evaluate circadian characteristics such as period length at the tissue-autonomous level by monitoring clock gene expression in real time. This culture method is also used to examine the tissue specificity of circadian entrainment factors. However, an ex vivo culture method for monitoring clock gene expression in hair follicles has yet to be established. In the present study, we developed an experimental method to analogize and evaluate circadian characteristics by performing ex vivo culture of mouse whisker follicles and monitoring clock gene expression in real time.

AN ACCIDENT OF INTERNAL CONTAMINATION WITH PLUTONIUM AND AMERICIUM AT A NUCLEAR FACILITY IN JAPAN: A PRELIMINARY REPORT AND THE POSSIBILITY OF DTPA ADMINISTRATION ADDING TO THE DIAGNOSIS

This article introduces the first accident of internal contamination with plutonium (Pu) or americium (Am) in Japan for which treatment was carried out. An accident of internal contamination with Pu and Am occurred at a Pu research facility at Oarai-town of Ibaraki prefecture in Japan. A plastic bag containing these radionuclides ruptured when five workers were inspecting a storage container in a hood. As a consequence, these workers were internally contaminated with Pu and Am. Although contamination on the body surface was observed in all five workers, a positive nasal swab was detected in only three of them. A chelating agent, calcium diethylenetriaminepenta-acetate (CaDTPA), was administered to all of them including the two workers without a positive nasal swab. However, bioassay detected a significant amount of Pu and Am in urine after administration of DTPA in these two workers, whereas the levels of these nuclides were below minimum detectable levels in urine before the administration. Since the prevalence of adverse reactions in DTPAs is low, the present results suggest that administration of DTPA can be used for the diagnosis of internal contamination even when a nasal swab is negative or contamination around body orifices is not detected.

Experiences of Population Monitoring Using Whole-Body Counters in Response to the Fukushima Nuclear Accident

Whole-body counter measurements of residents of Fukushima Prefecture have been extensively performed after the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. These measurements have demonstrated that the levels of internal contamination with radioactive cesium (Cs and Cs) in the residents are very low. This article provides an overview of and lessons learned from these whole-body counter measurements with emphasis on the technical problems encountered, and it discusses the effective use of whole-body counters for assessing the internal thyroid doses of individuals when direct measurements of I in the thyroid are difficult or impossible to implement for the total affected population in a short time after a nuclear reactor accident. The application of this dose reconstruction method requires determining the intake ratio of I to cesium isotopes at appropriate times and considers the short biological half-lives of cesium isotopes, in particular for children.

Involvement of the luteinizing hormone surge in the regulation of ovary and oviduct clock gene expression in mice

Circadian dysfunction perturbs the female reproductive cycle. In particular, mice lacking the clock gene Bmal1 show severe infertility, implying that BMAL1 plays roles in ovulation and luteinization. Here, we examined temporal changes in clock gene expression in the ovary and oviduct before and during gonadotropin-induced follicular growth, ovulation, and luteinization in sexually immature mice. While the oviduct did not show a drastic change in clock gene expression, Bmal1 expression in the ovary was higher than that in control mice during the period from 4 to 16 hr after human chorionic gonadotropin (hCG) administration. Bmal1 expression reached a maximum at 16 hr after hCG administration, when follicle luteinization occurred. In an interesting manner, administration of hCG to ex vivo-cultured oviduct triggered a shorter circadian period and inevitably resulted in phase advance. Together, our present data suggest that LH surge induces continuous expression of BMAL1 in the mouse ovary and modulates circadian phase in the mouse oviduct.

Potential role of the pancreatic hormone insulin in resetting human peripheral clocks

Mammalian circadian rhythms are phase-adjusted and amplified by external cues such as light and food. While the light input pathway via the central clock, the suprachiasmatic nucleus, has been well defined, the mechanism of feeding-induced circadian resetting remains undefined, particularly in humans. Animal studies have indicated that insulin, a pancreatic hormone that is secreted rapidly in response to feeding, is an input factor for a few peripheral clocks, such as liver and adipose tissue. In this study, using plucked and cultured hair follicles as a representative human peripheral clock, we examined the effect of insulin on circadian characteristics of clock gene expression. Our results demonstrate that insulin phase-shifts or amplifies the clock gene expression rhythms of ex vivo cultured hair follicles in a phase-responsive manner. To reduce the possibility that differences in species, genetic or environmental background, and experimental methods affected experimental outcomes, we also treated surgically extracted whisker follicles of Period2::Luciferase (Per2^Luc ) mice with insulin and found that the effect of insulin on clock gene expression was reproducible. These results suggest the possibility that feeding-induced insulin resets peripheral circadian clocks in humans.

Abstract P3-05-09: Prognostic factors for therapeutic personalized peptide vaccines in patients with metastatic recurrent breast cancer

Background: We have previously reported the prognostic role of humoral antigen spreading response against prostate-related antigen (PRA) for metastatic recurrent breast cancer (mrBC) patients who received personalized peptide vaccine (PPV) therapy (Toh U, SABCS 2015). The prognostic effect was additionally evaluated by the clinical relevant factors including intrinsic subtype, the regimens of combined chemo-hormonal therapies in present study.

Methods:We analyzed serum IgG responses to all of the peptide candidates included PRAs (PSA, PAP and PMSA) after PPV therapy by the Luminex systemusing peripheral blood samples from 77 vaccinated mrBC patients. The clinical factors and relevant events were statistically evaluated.

Results: After 6 and 12cycles of PPV therapy, the serum IgG of anti-PSA, anti-PAP, and/or anti-PMSA increased significantly in 31 patients (PRA response group), and the median progression free survival (PFS) and median overall survival (OS) were 8.1 and 14.3 months, but were 5.1 and 10.8 months, respectively, in the remaining 46 patients with no anti-PRA IgG response (PRA non-response Group). The anti-PRA IgG level was marginally correlated withPFS (p=0.059) and OS (p=0.082) between these two groups, which was a significant prognostic factor for PFS (Log-rank: 0.009) in estrogen-positive cancer patients (ER+). The statistical analyses showed that the clinical outcome was in favor of > 60 year-old patients, those with longer PPV therapies (>3 months), and those who received combined standard hormonal therapies or bisphosphonate/anti-RANKL therapy.

Conclusions: This study indicated a clinical significance between the pre-and post- PPV therapy measurement of serum anti-PRA IgG in patients with mrBC, which may be a useful prognostic marker for monitoring peptide vaccine treatment outcomes, particularly for patients > 60 years with ER+ breast cancer. These results also suggest that the immunotherapeutic peptide vaccine could be efficiently combined with hormonal therapy, anti-HER2 therapy, and bisphosphonate/anti-RANKL therapy in mrBC patients.

Citation Format: Toh U, Saku S, Iwakuma N, Takao Y, Okabe M, Akashi M, Yamada A, Shichijo S, Itoh K, Akagi Y. Prognostic factors for therapeutic personalized peptide vaccines in patients with metastatic recurrent breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-09.

Nuclear and radiological emergencies: Building capacity in medical physics to support response

Medical physicists represent a valuable asset at the disposal of a structured and planned response to nuclear or radiological emergencies (NREs), especially in the hospital environment. The recognition of this fact led the International Atomic Energy Agency (IAEA) and the International Organization for Medical Physics (IOMP) to start a fruitful collaboration aiming to improve education and training of medical physicists so that they may support response efforts in case of NREs. Existing shortcomings in specific technical areas were identified through international consultations supported by the IAEA and led to the development of a project aiming at preparing a specific and standardized training package for medical physicists in support to NREs. The Project was funded through extra-budgetary contribution from Japan within the IAEA Nuclear Safety Action Plan. This paper presents the work accomplished through that project and describes the current steps and future direction for enabling medical physicists to better support response to NREs.

Effect of different light-dark schedules on estrous cycle in mice, and implications for mitigating the adverse impact of night work

Approximately 20% of workers in developed countries are involved in night work. Nevertheless, many studies have strongly suggested that night-work-induced chronic circadian misalignment increases the risk of a diverse range of health problems. Although a relation between night work and irregular menstrual cycles has been indicated epidemiologically, a direct causal link remains elusive. Here, we report that repetitive reversal of light-dark (LD) cycles triggers irregular estrous cycles in mice. The findings showed that the estrous cycle remained irregular for more than four weeks after the mice were returned to regular LD cycles. Importantly, the magnitude of the negative impact of reversed LD cycles on the estrous cycle, or more specifically the decreased number of normal estrous cycles during the observation period, was dependent on the difference in the frequency of LD reversal. Presently, no clear solution to prevent night-work-mediated menstrual abnormalities is available, and reducing night work in modern society is difficult. Our findings indicate that optimizing work schedules could significantly prevent menstrual problems without reducing total night-work time.

Potential contribution of tandem circadian enhancers to nonlinear oscillations in clock gene expression

Limit-cycle oscillations require the presence of nonlinear processes. Although mathematical studies have long suggested that multiple nonlinear processes are required for autonomous circadian oscillation in clock gene expression, the underlying mechanism remains controversial. Here we show experimentally that cell-autonomous circadian transcription of a mammalian clock gene requires a functionally interdependent tandem E-box motif; the lack of either of the two E-boxes results in arrhythmic transcription. Although previous studies indicated the role of the tandem motifs in increasing circadian amplitude, enhancing amplitude does not explain the mechanism for limit-cycle oscillations in transcription. In this study, mathematical analysis suggests that the interdependent behavior of enhancer elements including not only E-boxes but also ROR response elements might contribute to limit-cycle oscillations by increasing transcriptional nonlinearity. As expected, introduction of the interdependence of circadian enhancer elements into mathematical models resulted in autonomous transcriptional oscillation with low Hill coefficients. Together these findings suggest that interdependent tandem enhancer motifs on multiple clock genes might cooperatively enhance nonlinearity in the whole circadian feedback system, which would lead to limit-cycle oscillations in clock gene expression.

Multiple circadian transcriptional elements cooperatively regulate cell-autonomous transcriptional oscillation of Period3, a mammalian clock gene

Cell-autonomous oscillation in clock gene expression drives circadian rhythms. The development of comprehensive analytical techniques, such as bioinformatics and ChIP-sequencing, has enabled the genome-wide identification of potential circadian transcriptional elements that regulate the transcriptional oscillation of clock genes. However, detailed analyses using traditional biochemical and molecular-biological approaches, such as binding and reporter assays, are still necessary to determine whether these potential circadian transcriptional elements are actually functional and how significantly they contribute to driving transcriptional oscillation. Here, we focused on the molecular mechanism of transcriptional oscillations in the mammalian clock gene Period3 (Per3). The PER3 protein is essential for robust peripheral clocks and is a key component in circadian output processes. We found three E box-like elements located upstream of human Per3 transcription start sites that additively contributed to cell-autonomous transcriptional oscillation. However, we also found that Per3 is still expressed in a circadian manner when all three E box-like elements are functionally impaired. We noted that Per3 transcription was activated by the synergistic actions of two D box-like elements and the three E box-like elements, leading to a drastic increase in circadian amplitude. Interestingly, circadian expression of Per3 was completely disrupted only when all five transcriptional elements were functionally impaired. These results indicate that three E box-like and two D box-like elements cooperatively and redundantly regulate cell-autonomous transcriptional oscillation of Per3.

Effects of bright light exposure during daytime on peripheral clock gene expression in humans

Light is the strongest synchronizer controlling circadian rhythms. The intensity and duration of light change throughout the year, thereby influencing body weight, food preferences, and melatonin secretion in humans and animals. Although the expression of clock genes has been examined using human samples, it currently remains unknown whether bright light during the daytime affects the expression of these genes in humans. Therefore, we herein investigated the effects of bright light exposure during the daytime on clock gene expression in the hair follicular and root cells of the human scalp. Seven healthy men (20.4 ± 2.2 years old; 172.3 ± 5.8 cm; 64.3 ± 8.5 kg; BMI 21.7 ± 3.1 kg/m², mean ± SD) participated in this study. Subjects completed 3-day experimental sessions twice in 1 month during which they were exposed to bright and dim light conditions. The mRNA expression of Per1-3, Cry1-2, Rev-erb-α (Nr1d1), Rev-erb-β (Nr1d2), and Dec1 was analyzed using branched DNA probes. No significant changes were observed in the expression of Per1, Per2, Per3, Cry1, Cry2, Rev-erb-α (Nr1d1), or Dec1 following exposure to bright light conditions. However, the expression of Rev-erb-β (Nr1d2) tended to be stronger under bright light than dim light conditions. These results suggest that the bright light stimulus did not influence the expression of clock genes in humans. Long-lasting bright light exposure during the daytime may be required to change the expression of clock genes in humans.

Early Intake of Radiocesium by Residents Living Near the Tepco Fukushima Dai-ichi Nuclear Power Plant After the Accident. Part 2: Relationship Between Internal Dose and Evacuation Behavior in Individuals

The Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident exposed members of the public to radiation. This study analyses the relation between personal behavior data obtained from 112 out of 174 subjects who underwent whole-body measurements by the National Institute of Radiological Sciences (NIRS) during the period from 27 June to 28 July 2011 and their committed effective doses (CEDs) from Cs and Cs. The whereabouts of the 112 persons living in municipalities near the FDNPP (mainly, Namie town) on several days in March 2011 are graphed on maps. It was confirmed that most subjects started evacuation promptly and had left the 20-km-radius of the FDNPP by the end of 12 March. The individual CEDs were poorly correlated with the person's distances from the FDNPP at any day in March. Meanwhile, the percentage of persons remaining within the 20-km radius of the FDNPP was 100% at 16:00 on 12 March and 42.9% at 0:00 on 15 March for those with CEDs > 0.1 mSv, whereas the corresponding values were much lower for those with CEDs ≤ 0.1 mSv. This suggests that the time of evacuation would be one of the crucial factors for the early intake; however, more personal behavior data are needed to be analyzed to clarify the relevance to the individual internal dose.

Hypercholesterolemia Causes Circadian Dysfunction: A Potential Risk Factor for Cardiovascular Disease

Hypercholesterolemia is a well-known risk factor for a wide range of diseases in developed countries. Here, we report that mice lacking functional LDLR (low density lipoprotein receptor), an animal model of human familial hypercholesterolemia, show circadian abnormalities. In free running behavioral experiments in constant darkness, these mice showed a prolonged active phase and distinctly bimodal rhythms. Even when the circadian rhythms were entrained by light and dark cycles, these mice showed a significant attenuation of behavioral onset intensity at the start of the dark period. Further, we hypothesized that the combination of hypercholesterolemia and circadian abnormalities may affect cardiovascular disease progression. To examine this possibility, we generated LDLR-deficient mice with impaired circadian rhythms by simultaneously introducing a mutation into Period2, a core clock gene, and found that these mice showed a significant enlargement of artery plaque area with an increase in inflammatory cytokine IL-6 levels. These results suggest that circadian dysfunction may be associated with the development or progression of cardiovascular diseases.

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Mice lacking LDLR (low density lipoprotein receptor), a mouse model for hypercholesterolemia, show circadian abnormalities.

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LDLR-deficient mice with a mutation in Period2, a core clock gene, show a significant enlargement of artery plaque area.

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Per2 mutation-induced increase in plasma inflammatory cytokines may cause modification of arteriosclerosis.

Hypercholesterolemia is a common pathology in advanced countries, occurring in 10% to 30% of the population. Here, we report that mice lacking LDLR (low density lipoprotein receptor), an animal model for hypercholesterolemia, experienced chronic circadian abnormalities. Further, we found that LDLR-deficient mice with a mutation in Period2, a clock gene, showed a significant enlargement of artery plaque area. Together, our findings indicate that hypercholesterolemia induces circadian abnormalities, leading to a decline in the quality of social life and an increase in the risk of circadian-related diseases, and that circadian dysfunction might affect the development or progression of hypercholesterolemia-related diseases.

The Relationship Between Functional Independence and Psychological Distress in Elderly Adults Following the Fukushima Daiichi Nuclear Power Plant Accident

This study aimed to explore the relationship between psychological distress and degree of functional independence among elderly adults following the Great East Japan Earthquake. Participants were 20 282 adults aged 65 and older who lived in the Great East Japan Earthquake evacuation zone specified by the government on March 31, 2011. This study is a part of a detailed survey on mental health and lifestyle, the Fukushima Health Management Survey, which was conducted in 2012. Psychological distress was assessed using the Kessler 6 scale. Functional independence in different daily activities was assessed by asking participants whether they could independently perform activities: eating, dressing, toileting, and shopping. According to the multiple logistic regression analysis, psychological distress was significantly associated with independence in all models: without adjustment (Model 1), adjusting for demographic characteristics (Model 2), and adjusting for demographic characteristics and disaster-related factors (Model 3), with an adjusted odds ratio of 2.32 (95% confidence interval = 1.97-2.73). High psychological distress was associated with low functional independence, after controlling for demographic characteristics and disaster-related factors. Thus, using psychological distress as the dependent variable, we examined the relationship between low functional independence and psychological distress among elderly adults who were evacuated.