Cd-content and temperature dependences of hyperfine fields in CdxFe3-xO4

Cd-content and temperature dependences of hyperfine fields in CdxFe3-xO4 (0 ≤ x ≤ 0.5) were investigated by means of time-differential perturbed angular correlation spectroscopy with the 111Cd(←111In) probe. It was found that Cd2+ ions selectively occupy the tetrahedral A site in the spinel structure in all the range of the present Cd content x. The magnetic transition temperature TC becomes lower with increasing x due to the interference of the long-range ordering of Fe spins as a result of expansion of the lattice constants by Cd doping. The measurement of room-temperature hyperfine fields at different x shows that the supertransferred magnetic hyperfine field (SMHF) at the probe decreases as x increases in the range of 0 ≤ x ≤ 0.5. Isothermal measurements at 15 K revealed a contrastive phenomenon for the Cd contents up to x = 0.4: the SMHF becomes great with increasing x; however, this increasing trend of the SMHF turns to reduction at x = 0.46. These observations can be explained based on the effect of Cd doping on the antiferromagnetic coupling between Fe ions in the A and B sites.

Upregulated expression of lamin B receptor increases cell proliferation and suppresses genomic instability: implications for cellular immortalization

Mammalian somatic cells undergo terminal proliferation arrest after a limited number of cell divisions, a phenomenon termed cellular senescence. However, cells acquire the ability to proliferate infinitely (cellular immortalization) through multiple genetic alterations. Inactivation of tumor suppressor genes such as p53, RB and p16 is important for cellular immortalization, although additional molecular alterations are required for cellular immortalization to occur. Here, we aimed to gain insights into these molecular alterations. Given that cellular immortalization is the escape of cells from cellular senescence, genes that regulate cellular senescence are likely to be involved in cellular immortalization. Because senescent cells show altered heterochromatin organization, we investigated the implications of lamin A/C, lamin B1 and lamin B receptor (LBR), which regulate heterochromatin organization, in cellular immortalization. We employed human immortalized cell lines, KMST-6 and SUSM-1, and found that expression of LBR was upregulated upon cellular immortalization and downregulated upon cellular senescence. In addition, knockdown of LBR induced cellular senescence with altered chromatin configuration. Additionally, enforced expression of LBR increased cell proliferation likely through suppression of genome instability in human primary fibroblasts that expressed the simian virus 40 large T antigen (TAg), which inactivates p53 and RB. Furthermore, expression of TAg or knockdown of p53 led to upregulated LBR expression. These observations suggested that expression of LBR might be upregulated to suppress genome instability in TAg-expressing cells, and, consequently, its upregulated expression assisted the proliferation of TAg-expressing cells (i.e. p53/RB-defective cells). Our findings suggest a crucial role for LBR in the process of cellular immortalization.

Ramucirumab plus FOLFIRI as second-line treatment for patients with RAS wild-type metastatic colorectal cancer previously treated with anti-EGFR antibody: JACCRO CC-16

BACKGROUND

Chemotherapy in combination with anti-epidermal growth factor receptor (EGFR) antibody is considered a first-line treatment regimen for RAS wild-type and left-sided metastatic colorectal cancer (mCRC), whereas second-line treatment regimens have not yet been established. Few studies have prospectively evaluated second-line treatment with anti-vascular endothelial growth factor antibody after first-line anti-EGFR antibody therapy for RAS wild-type mCRC.

PATIENTS AND METHODS

This non-randomized phase II trial investigated the clinical outcomes of second-line ramucirumab (RAM) plus fluorouracil, levofolinate, and irinotecan (FOLFIRI) after first-line anti-EGFR antibody in combination with doublet or triplet regimen in patients with RAS wild-type mCRC. The primary endpoint was the 6-month progression-free survival (PFS) rate. The secondary endpoints were PFS, overall survival (OS), objective response rate (ORR), rate of early tumor shrinkage (ETS), and safety. We hypothesized a threshold 6-month PFS rate of 30% and an expected 6-month PFS rate of 45%. Treatment was considered effective if the lower limit of the 90% confidence interval (CI) of the 6-month PFS rate was >0.30.

RESULTS

Ninety-two patients were enrolled in the study. The primary tumor was located on the left side in 86 (95.6%) patients. Twenty (22.0%) patients had received triplet plus cetuximab as previous therapy. Six-month PFS rate was 58.2% (90% CI 49.3% to 66.2%) with a median PFS of 7.0 months (95% CI 5.7-7.6 months). Median OS was 23.6 months (95% CI 16.5-26.3 months). The ORR and ETS rate were 10.7% and 16.9%, respectively, in 83 patients with measurable lesions. The 6-month PFS rate was comparable between patients previously treated with doublet and triplet regimens; however, median PFS was longer for the doublet regimen (7.4 versus 6.4 months, P = 0.036).

CONCLUSIONS

Our study demonstrated prospectively that RAM plus FOLFIRI is an effective second-line treatment after anti-EGFR antibody-containing first-line therapy in RAS wild-type and left-sided mCRC. Furthermore, the results were similar for patients who were previously treated with triplet regimen.

The key role of a basic domain of histone H2B N-terminal tail in the action of 5-bromodeoxyuridine to induce cellular senescence

5-Bromodeoxyuridine (BrdU), a thymidine analogue, is an interesting reagent that modulates various biological phenomena. BrdU, upon incorporation into DNA, causes destabilized nucleosome positioning which leads to changes in heterochromatin organization and gene expression in cells. We have previously shown that BrdU effectively induces cellular senescence, a phenomenon of irreversible growth arrest in mammalian cells. Identification of the mechanism of action of BrdU would provide a novel insight into the molecular mechanisms of cellular senescence. Here, we showed that a basic domain in the histone H2B N-terminal tail, termed the HBR (histone H2B repression) domain, is involved in the action of BrdU. Notably, deletion of the HBR domain causes destabilized nucleosome positioning and derepression of gene expression, as does BrdU. We also showed that the genes up-regulated by BrdU significantly overlapped with those by deletion of the HBR domain, the result of which suggested that BrdU and deletion of the HBR domain act in a similar way. Furthermore, we showed that decreased HBR domain function induced cellular senescence or facilitated the induction of cellular senescence. These findings indicated that the HBR domain is crucially involved in the action of BrdU, and also suggested that disordered nucleosome organization may be involved in the induction of cellular senescence.

Bi-directional relationships of arterial stiffness with hypertension and diabetes mellitus from the early pathophysiological stages: a 16-year prospective observational study

Background

Hypertension and diabetes mellitus frequently coexist; however, it has not yet been clarified if the bidirectional longitudinal relationships between arterial stiffness and hypertension are independent of those between arterial stiffness and diabetes mellitus.

Methods

In this 16-year prospective observational study, 3960 middle-aged employees of a Japanese company without hypertension/diabetes mellitus at the study baseline underwent annual repeated measurements of the blood pressure, serum glycosylated hemoglobin A1c levels (HbA1c), and brachial-ankle pulse wave velocity (baPWV).

Results

By the end of the study period, 664, 779, 154, and 406 subjects developed hypertension, prehypertension, diabetes mellitus, and prediabetes, respectively. Increased baPWV at the baseline was associated with a significant odds ratio (per 1 standard deviation increase) for new onset of prehypertension/hypertension with (2.45/3.28, P<0.01) or without (2.49/2.76, P<0.01) coexisting prediabetes/diabetes mellitus, but not for new onset of prediabetes/diabetes mellitus without coexisting hypertension. Analyses using the latent growth curve model confirmed the bidirectional relationships between baPWV and hypertension, but no such relationship was observed between baPWV and abnormal glucose metabolism. Moreover, after the adjustments, higher mean blood pressure at baseline accelerated the increases in the baPWV over follow-up (unstandardized coefficient [B] = 0.39, standard error [SE] = 0.05x10–1, P<0.01). Similarly, higher baPWV at baseline accelerated the increases in mean blood pressure over follow-up (B = 0.02x10–1, SE = 0.01x10–1, P<0.01) (Figure 1). On the other hands, higher HbA1c levels at baseline accelerated the increases in the baPWV over follow-up (B = 0.43, SE = 0.05x10–1, P<0.01), but higher baPWV at baseline did not accelerate the increases in HbA1c levels over follow-up (B <0.01, SE <0.01, P=0.52) (Figure 2).

Conclusions

In middle-aged employees of a Japanese company, in contrast to the bidirectional relationships that exist between arterial stiffness and hypertension, increased arterial stiffness preceding the development of diabetes mellitus may represent that associated with the development of hypertension, as it is observed only in cases of diabetes mellitus coexisting with hypertension. Therefore, arterial stiffness may be associated to a greater degree with the development of hypertension than with the development of diabetes mellitus.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Omron Health Care Company (Kyoto, Japan),Teijin Pharma Company (Tokyo, Japan)

Age-related differences in longitudinal associations between alcohol intake and arterial stiffness, pressure wave reflection, and inflammation in male employees

Backgrounds

While arterial stiffness and abnormal pressure wave reflection are independent cardiovascular risk, the difference of their association with alcohol intake have not been fully clarified.

Aim

This prospective observational study, which utilized repeated annual measurements performed over a 9-year period, applied mixed model analyses to examine age-related differences in longitudinal associations between alcohol intake and arterial stiffness, pressure wave reflection, and inflammation.

Methods

In 4016 middle-aged (43±9 years) healthy Japanese male employees, alcohol intake, brachial-ankle pulse wave velocity (baPWV), radial augmentation index (rAI), and serum C-reactive protein (CRP) levels were measured annually during a 9-year study period. Based on the questionnaire, alcohol intake was classified as non-drinker, mild-moderate drinker (ethanol 1–20 g/day) and heavy drinker (>20 g/day).

Results

The estimated marginal mean baPWV (non-drinkers = 1306 cm/s, mild-moderate drinkers = 1311 cm/s, and heavy drinkers = 1337 cm/s, P<0.01) and that of rAI showed significant stepped increases in an alcohol dose-dependent manner in the entire cohort, but an increase in rAI was not observed in subjects aged ≥50 years. The estimated slope of the annual increase in baPWV, but not rAI, was higher for heavy drinkers than for non-drinkers (slope difference, 2.73; P<0.01), especially for subjects aged <50 years. The estimated marginal mean of the serum CRP levels was lower for drinkers than for non-drinkers.

Conclusion

In middle-aged male Japanese employees, alcohol intake may attenuate inflammatory activity. While alcohol intake may exacerbate the progression of arterial stiffening in a dose-dependent manner without mediating inflammation, especially in subjects under 50 years of age, it may promote pressure wave reflection abnormalities with aging at earlier ages without further exacerbation at older ages.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Omroncarpis

O-288 Association of initial zygote cleavage, compaction pattern and euploidy rates: possible implications for embryo correction mechanisms

Study question

Is the morula compaction pattern associated with early zygote cleavage anomalies and euploidy rates? Can it represent a possible mechanism of embryonic correction?

Summary answer

Abnormalities in the first divisions give rise to dysfunctional blastomeres, which were excluded from compaction process. This process represent a possible embryonic correction mechanism.

What is known already

IVF embryos have historically been analyzed based on morphological characteristics focusing on days 2/3 (cleavage stage) and 5/6 (blastocyst). The morula stage, usually reached on day 4, represent a transitional phase resulting from the embryonic genome activation and has received little attention in clinical embryology. However, during this crucial stage, cell differentiation begins, metabolism reaches higher levels, changes in cell shape and cell-destination mechanisms are enhanced, providing opportunities for “quality control”. At morula stage, embryos with severe genetic abnormalities are sorted out by natural selection or possibly self-correction events may occurs, reducing the load of aneuploid cells in mosaic embryos.

Study design, size, duration

We evaluated laboratory and clinical outcomes of 836 blastocysts (195 ICSI cycles) cultured in a time-lapse system and biopsied for preimplantation genetic testing for aneuploidy (PGT-A), from April-2018 to June-2020. Time-lapse videos were retrospectively analyzed to assess morphokinetic parameters of initial zygote cleavages and morula compaction. These parameters were evaluated and associated to genetic and embryonic outcomes. Blastocyst outcomes were also assessed according to maternal age <35 (n = 140), 35-37 (n = 175), 38-40 (n = 314) and >40 (n = 207).

Participants/materials, setting, methods

The zygote initial cleavages were classified as normal (1-2-4 cleavage) or anomalous: 1-3 cleavage (zygote splits directly into three blastomeres); 1-2-3 cleavage (2-3 in < 3h); and 1-2-5 cleavage (after the first normal cleavage, one blastomere splits directly into three blastomeres). Morula were classified as: Fully Compacted Morulae (FCM); Partially Compacted Morulae (PCM). The PCM could have cells excluded from the compaction process (Exc-PCM), extruded from an already compacted morula (Ext-PCM), or both situations (Exc/Ext-PCM).

Main results and the role of chance

Most blastocysts showed normal zygotic cleavage (83.3%). Anomalous cleavage such as 1-3 (0.8%), 1-2-3 (7.2%) and 2-5 (8.7%) were less prevalent and no differences were observed according to female age (p = 0.268). Overall, FCM (61.0%) was a more frequent pattern than PCM (39.0%). According to compaction pattern of PCM, Exc-PCM (25.1%) was more prevalent than Ext-PCM (11.5%) and Exc/Ext-PCM (2.4%). There was also no difference in the prevalence of the morulae compaction pattern according to female age (p = 0.124). FCM occurred in 511 embryos (73.4%) from zygotes with normal cleavage (n = 696), but no FCM was observed among anomalous cleaved zygotes (p < 0.001). Genetic and embryonic outcomes were displayed as follows: normal cleavage and FCM (NC-FCM, n = 511), normal cleavage and PCM (NC-PCM, n = 185), and anomalous cleavage and PCM (AC-PCM, n = 140). NC-FCM and AC-PCM groups showed statistically similar euploidy rates (39.3% and 38.6%, p = 0.870), that were both significantly higher than the NC-PCM group euploidy rate (23.8%, p < 0.001). However, morphokinetic scores (KidScore) and percentage of top-quality blastocysts at morphological evaluation were discordant: NC-FCM (6.4±1.7; 81.4%), NC-PCM (5.0±1.8; 47.6%) and AC-PCM (4.3±2.0; 37.9%). Euploidy rate decreased with female age for all groups: NC-FCM (<35:54.7%, 35-37:56.0%, 38-40:33.3%, >40:24.1%); NC-PCM (<35:37.5%, 35-37:19.0%, 38-40:25.0%, >40:19.0%); AC-PCM (<35:66.7%, 35-37:48.5%, 38-40:39.0%, >40:3.7%).

Limitations, reasons for caution

The retrospective design of the study represents a general limitation. In addition, this study evaluated only embryos that reached the blastocyst stage and showed enough quality to be biopsied. Therefore, the association between anomalies in the first and second mitotic cleavages and the embryonic development could not be evaluated.

Wider implications of the findings

Similar euploidy rates among NC-FCM and AC-PCM support the hypothesis that cell exclusion/extrusion in compaction stage of anomalous-cleaved zygotes can represent a potential correction mechanism, even though lower morphological/morphokinetic scores are seen on AC-PCM. That process is supposed to rescue embryos from the mosaic aneuploidy which occurs after abnormal cleavage.

Trial registration number

not applicable

Dynamic changes in RAS gene status in circulating tumour DNA: a phase II trial of first-line FOLFOXIRI plus bevacizumab for RAS-mutant metastatic colorectal cancer (JACCRO CC-11)

Background

Few prospective studies have used liquid biopsy testing in RAS-mutant metastatic colorectal cancer (mCRC), and its clinical significance remains unknown. Therefore, this study aimed to carry out a biomarker analysis by liquid biopsy using updated data of the phase II trial of FOLFOXIRI plus bevacizumab as first-line chemotherapy for RAS-mutant mCRC.

Materials and methods

A total of 64 patients who received modified FOLFOXIRI regimen (irinotecan 150 mg/m², oxaliplatin 85 mg/m², levofolinate 200 mg/m², and fluorouracil 2400 mg/m²) plus bevacizumab biweekly were enrolled. The primary endpoint was the objective response rate (ORR). Plasma samples were collected at pre-treatment, 8 weeks after treatment, and progression in participants included in the biomarker study. The levels of circulating tumour DNA (ctDNA) and specific KRAS and NRAS variants were evaluated using real-time PCR assays.

Results

There were 62 patients (median age: 62.5 years, 92% performance status 0, 27% right side) who were assessable for efficacy and 51 for biomarker analysis. ORR was 75.8% (95% confidence interval 65.1% to 86.5%). The median progression-free survival was 12.1 months, and the median overall survival (OS) was 30.2 months. In 78% of patients, RAS mutations disappeared in the ctDNA at 8 weeks after treatment; these patients tended to have better outcomes than those with RAS mutations. Interestingly, RAS mutations remained undetectable during progression in 62% of patients. Survival analysis indicated that the median OS from progression was significantly longer in patients with RAS mutation clearance than in those with RAS mutation in the ctDNA at disease progression (15.1 versus 7.3 months, hazard ratio: 0.21, P = 0.0046).

Conclusions

Our biomarker study demonstrated no RAS mutations in ctDNA at disease progression in 62% of patients with RAS-mutant mCRC. Both OS and post-progression survival were better in patients with clearance of RAS mutations in ctDNA after triplet-based chemotherapy.

•

First-line FOLFOXIRI plus bevacizumab is effective for RAS-mutant mCRC with comparable efficacy in elderly patients.

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RAS mutations disappeared in ctDNA after intensive chemotherapy in 62% of patients with mCRC with RAS-mutant tumours.

•

Survival time was longer in patients with RAS mutation clearance than in those with RAS mutations in ctDNA.

The mechanisms of age-realted difference of annual changes in ankle-brachial pressure index

 

In addition to both pulse wave velocity (PWV; a marker of arterial stiffness) and augmentation index (AI; a marker of central hemodynamics), not only the decrease of ankle-brachial pressure index (ABI) but also its increase predict the future cardiovascular events. While arterial stiffness and central hemodynamics have been proposed to affect the increase in ABI logically, their effects on increase in ABI have not been fully clarified. The present cross-sectional and longitudinal studies were conducted to examine the associations of arterial stiffness and central hemodynamics with increase in ABI and also examine the age-related difference of those associations. In 4016 men (42±9 years old), ABI, brachial-ankle PWV (baPWV) and radial AI (rAI) were measured annually for 9 years' observation period. In the cross-sectional analyses adjusted with age, heart rate and mean blood pressure, both baPWV and rAI were associated with ABI in men aged <50, but not in men aged >50. As shown in Figure, ABI was annually increased in subjects aged <50 (n=2870), but not in those aged >50 (n=1146) during the follow-up period. The mixed model linear regression analysis (MMA) conducted in 9 years' annual repeated measurement data demonstrated that increased baPWV (estimate = 0.017, p<0.05) and increased rAI (estimate 0.254, p<0.05) were significant determinant of annual increase of ABI (p<0.01) in men aged <50, but not in men aged >50. In conclusion, the arterial stiffness and central hemodynamics may individually affect the increase in ABI in men aged <50, but not in men >50. Thus, further studies are needed to clarify whether ABI, arterial stiffness, and central hemodynamics individually predicts future cardiovascular events, and their age-related difference of their predictabilities.

figure1

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Tokyo Medical University

The associations among arterial stiffness, endothelial dysfunction and the progression of carotid atherosclerosis in hypertensive subjects with/without carotid atherosclerosis

Background

While arterial stiffness and endothelial dysfunction, which are diffuse vascular damage, are phenotypes of vascular damage, their associations with the progression of atherosclerosis, which is focal vascular damage, has not been fully clarified. The present prospective observational study was conducted to examine whether arterial stiffness and endothelial dysfunction predict the progression of carotid atherosclerosis in subjects medicated for hypertension with/without carotid atherosclerosis.

Methods and results

In 617 subjects receiving antihypertensive treatment, we conducted flow-mediated vasodilatation (FMD), brachial-ankle pulse wave velocity (baPWV) and common carotid artery intima-media thickness mean and maximal (IMTmean and IMTmax) at the baseline and the end (3 years' later) of study periods. During the study period, FMD was decreased and baPWV, IMTmean and IMTmax were increased significantly. In subjects without carotid atherosclerosis (IMTmax <1.1mm, n=416), baPWV, but not FMD, at baseline had significant associations with IMTmean and IMTmax at both the baseline and end of study period. As shown in Figure, the changes of IMTmean and also IMTmax during the study period were higher in the highest tertile ranges of baPWV at the baseline than in the lowest tertile range of baPWV. On the other hand, in subjects with carotid atherosclerosis (IMTmax >1.1mm, n=201), both baPWV and FMD were not associated with any markers of carotid atherosclerosis and also their changes during the study period.

Conclusion

In subjects with hypertension, arterial stiffness rather than endothelial dysfunction may be associated with the progression of carotid atherosclerosis, and this association may be significant in the premature stage of atherosclerosis.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Omron Healthcare, Asahikasei Calpis

Mineral trioxide aggregate suppresses pro-inflammatory cytokine expression via the calcineurin/nuclear factor of activated T cells/early growth response 2 pathway in lipopolysaccharide-stimulated macrophages

AIM

To elucidate mechanisms by which mineral trioxide aggregate (MTA) suppresses pro-inflammatory cytokine mRNA expression in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages.

METHODOLOGY

Mineral trioxide aggregate extracts were prepared by immersing set ProRoot MTA in culture medium. RAW264.7 cells were cultured in the presence of LPS and MTA extracts. mRNA expression levels of interleukin (IL)-1α, IL-6, early growth response 2 (Egr2), suppressor of cytokine signalling 3 (Socs3) and IL-10 were quantified with reverse transcription-quantitative polymerase chain reaction. Phosphorylation of nuclear factor-kappa B (NF-κB) p65 in RAW264.7 cells was analysed by Western blotting. Intracellular calcium imaging was performed with Fluo-4 AM. The activity of nuclear factor of activated T cells (NFAT) was determined by luciferase assays. Enforced expression and silencing of Egr2 in RAW264.7 cells were carried out using an expression vector and specific RNAi, respectively. In vivo kinetics of Egr2⁺ cells in MTA-treated rat molar pulp tissues were examined using immunohistochemistry. Data were analysed by one-way analysis of variance, followed by the Tukey-Kramer test (P < 0.05).

RESULTS

Exposure to MTA extracts resulted in reduced mRNA expression levels of IL-1α and IL-6, as well as reduced expression of phosphorylated NF-κB, in LPS-stimulated RAW264.7 cells. Exposure to MTA extracts induced Ca²⁺ influx, which was blocked by NPS2143, an antagonist of calcium-sensing receptor (CaSR); Ca²⁺ influx then triggered activation of calcineurin/NFAT signalling and enhanced mRNA expression of Egr2. Enforced expression of Egr2 in RAW264.7 cells promoted the expression of both IL-10 and Socs3. In vivo application of MTA onto rat molar pulp tissue resulted in the appearance of Egr2-expressing cells that coexpressed CD163, a typical M2 macrophage marker.

CONCLUSIONS

Mineral trioxide aggregate extracts induced downregulation of IL-1α and IL-6 in LPS-stimulated RAW264.7 cells via CaSR-induced activation of calcineurin/NFAT/Egr2 signalling and subsequent upregulation of IL-10 and Socs3.

The role of lamin B receptor in the regulation of senescence-associated secretory phenotype (SASP)

Cellular senescence is a phenomenon of irreversible growth arrest of mammalian somatic cells. Senescent cells increase the production of secretory proteins such as inflammatory cytokines, a phenomenon termed senescence-associated secretory phenotype (SASP). SASP is known to have profound effects on organismal health and aging; however, the molecular mechanisms of SASP are not precisely understood. In our previous studies, we have shown that senescent cells show decreased function of lamin B receptor (LBR), a nuclear membrane protein that regulates heterochromatin organization. Here we examined the implication of LBR in the regulation of SASP because senescent cells show altered heterochromatin organization, which would affect gene expression. We found that knock-down of LBR up-regulated the expression of the SASP factors such as IL-6, IL-8, and MMP1 in HeLa cells, even though cellular senescence was not induced by LBR knock-down. Conversely, enforced expression of LBR suppressed their up-regulated expression in senescent cells induced by excess thymidine. Further, our gene expression profile analysis also showed that many secretory proteins were up-regulated by LBR knock-down. We then analyzed the regulatory mechanisms of the expression of SASP factors by LBR, and found that the promoters of these SASP factors associated with LBR in normally growing cells, but dissociated from it in senescent cells. Additionally, we found that enforced expression of LBR decreased the generation of cytoplasmic DNA, which could be involved in SASP, in senescent cells. These findings suggested that LBR would play crucial roles in the regulation of SASP.

Prevalence of human papillomavirus in oral gargles and tonsillar washings

OBJECTIVES

Human papillomavirus (HPV) infection drives carcinogenesis in the oropharynx. No standard sampling or HPV detection methods for evaluating oropharyngeal HPV infection exist. The prevalence of oral HPV infection in Japan is unknown.

MATERIALS AND METHODS

We examined 435 healthy Japanese individuals to address whether adding tonsillar washing to oral gargling would improve HPV detection. We compared HPV assessment using GENOSEARCH HPV31 versus nested PCR and direct sequencing. Associations between HPV infection and demographic and behavioral characteristics were examined.

RESULTS

Most participants who were HPV-positive based on oral gargles were also HPV-positive based on tonsillar washings: 11 (64.7%) of 17 on nested PCR and 12 (70.6%) of 17 on GENOSEARCH HPV31. Although HPV infection was more prevalent in oral gargles followed by tonsillar washings than in oral gargles alone, the difference was not statistically significant (nested PCR, 4.8% vs. 3.9%, P = 0.46; GENOSEARCH HPV31, 5.3% vs. 3.9%, P = 0.33). The overall agreement between nested PCR and GENOSEARCH HPV31 was 98.6%, with 76.0% positive agreement. The overall prevalence of oral HPV infection in Japan was 5.7% (95% confidence interval, 3.9-8.3%). Men had a significantly higher prevalence of oral HPV infection than women (8.3% vs. 2.6%, P = 0.02). Infection increased with number of lifetime sexual partners (P < 0.001 for trend).

CONCLUSION

The oropharynx is probably the major source of HPV-infected cells in oral gargles. Oral gargling could be a standard sampling method for evaluating oropharyngeal HPV infection. GENOSEARCH HPV31 could be an option for oral HPV detection.

Extract of Plumbago zeylanica enhances the growth of hair follicle dermal papilla cells with down-regulation of 5α-reductase type II

BACKGROUND

Cellular senescence, a phenomenon of irreversible growth arrest of mammalian cells, is involved in various age-related phenomena in organisms. Hair follicle dermal papilla (DP) cells play important roles in the regulation of hair growth and loss.

AIMS

We examined the implication of cellular senescence of DP cells in androgenetic alopecia (AGA), the most common form of male hair loss, and searched for the compounds that have a beneficial effect on the prevention of AGA.

PATIENTS/METHODS

Expression of the 5α-reductase type II (SRD5A2) gene, which plays a key role in the development of AGA, was examined by quantitative RT-PCR and Western blotting analysis in DP cells. Besides, DP cells were cultured with the extracts of herbs used in traditional Ayurvedic medicine to search for the compounds that have a beneficial effect on the growth of DP cells.

RESULTS

We found that expression of the SRD5A2 was up-regulated in senescent DP cells. We also found that the herbal extract of Plumbago zeylanica (root) enhanced the growth of DP cells and down-regulated the expression of SRD5A2 in DP cells. Further, plumbagin, an ingredient of P zeylanica, would be responsible for the above effects of P zeylanica.

CONCLUSION

These results suggested the possibility that senescent DP cells may have a role in the development of AGA through up-regulating SRD5A2 expression, and the P zeylanica extract and plumbagin may suppress its development through enhancing the growth of DP cells and down-regulating SRD5A2 expression in DP cells.

Lamin B receptor plays a key role in cellular senescence induced by inhibition of the proteasome

Cellular senescence is a terminal growth arrest phenomenon in mammalian cells. Coordinated regulation of protein synthesis and degradation is required to maintain protein homeostasis in cells; however, senescent cells exhibit decreased activity of the proteasome, a major cellular proteolytic machinery, with an accumulation of proteins. Indeed, we showed that MG132, a proteasome inhibitor, induced cellular senescence through an accumulation of proteins in human cells. We then investigated the mechanisms of cellular senescence induced by protein accumulation by treating cells with MG132. We found that lamin B receptor (LBR), a nuclear membrane protein that regulates heterochromatin organization, was mislocalized and down-regulated in cells on treatment with MG132. Importantly, enforced expression of LBR suppressed cellular senescence induced by MG132. We also showed that LBR was involved in the regulation of chromatin organization in senescent cells, and that endoplasmic reticulum stress and autophagy were likely to be involved in the mislocalization and down-regulation of LBR. These findings indicate that decreased LBR function was responsible for the induction of cellular senescence by MG132, and thus suggest that protein accumulation caused by inhibition of the proteasome induced cellular senescence probably through chromatin dysregulation in human cells.

P1632A possible independent contribution of liver stiffness to the development of heart failure in its early stage

Background

Heart failure (HF) is a heterogeneous condition. The reduced liver blood flow and hepatic congestion associated with HF causes liver damages leading to liver sclerosis. Fibrosis 4 score (FIB-4 score), a marker of liver sclerosis, is easily calculated from age, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) level and blood platelet count (PLT). Liver stiffness is known to be associated with vascular damages, including arterial stiffness and central hemodynamics. These vascular damages also cause the new onset of HF. However, it remains to be clarified whether liver stiffness is a direct risk factor for HF or whether its association with HF is mediated by vascular damage. We conducted cross-sectional and prospective longitudinal studies to examine whether FIB-4 score is directly associated with the serum NT-pro-BNP levels or the association is mediated by arterial stiffness and/or abnormal central hemodynamics.

Methods and results

In 3,040 health Japanese subjects with serum NT-pro-BNP levels <125 pg/ml, the FIB-4 score was calculated, and the serum NT-pro-BNP levels, brachial-ankle pulse wave (baPWV) velocity, radial augmentation index (rAI), second peak of the radial pressure waveform (SBP2) and PP2 (SBP2 – diastolic blood pressure) were measured. These parameters were measured again after a 3-year interval in 2,135 subjects. Pearson's correlation analysis demonstrated that FIB-4 score was significantly correlated with baPWV, rAI, SBP2, PP2 and the log-transformed the serum NT-pro-BNP levels. Multivariate linear regression analysis demonstrated a significant cross-sectional association of the FIB-4 scores with the log-transformed the serum NT-pro-BNP levels (beta = 0.08, p<0.01), but not with the baPWV, rAI, SBP2 and PP2. The change of serum NT-pro BNP levels during the study period was significantly higher in subjects with increase of the FIB-4 score during the study period (8.2±22.5 pg/ml) than that in those with decrease/no change (5.4±22.3 pg/ml) (p<0.05). The change of FIB-4 score during the study period was significantly associated with the change of the serum NT-pro-BNP levels during the study period (beta = 0.09, p<0.01).

Conclusion

Liver stiffness may have a significant direct association with the development of HF from the early stage, without the mediation of arterial stiffness and/or abnormal central hemodynamics. Therefore, the FIB-4 score appears to serve as a direct risk factor for HF from the early stage, and its association with HF may not be mediated by vascular damages.

Lamin B receptor (LBR) is involved in the induction of cellular senescence in human cells

Cellular senescence is a phenomenon of irreversible growth arrest in mammalian somatic cells in culture. Various stresses induce cellular senescence and indeed, we have found that excess thymidine effectively induces cellular senescence in human cells. Further, many reports indicate the implication of chromatin proteins in cellular senescence. Here we analysed the role of lamin B receptor (LBR), a nuclear envelope protein that regulates heterochromatin organization, in cellular senescence induced by excess thymidine. We then found that the LBR protein was down-regulated and showed aberrant localization in cells upon induction of cellular senescence by excess thymidine. Additionally, we also found that knock-down of LBR facilitated the induction of cellular senescence by excess thymidine in cancerous HeLa cells, and importantly, it induced cellular senescence in normal human diploid fibroblast TIG-7 cells. These results suggested that decreased LBR function is involved in the induction of cellular senescence in human cells.

Extract of Emblica officinalis enhances the growth of human keratinocytes in culture

OBJECTIVE

Keratinocytes are the predominant cell type in the epidermis and play key roles in epidermal function. Thus, identification of the compounds that regulate the growth of keratinocytes is of importance. Here we searched for such compounds from the herbs used in traditional medicine Ayurveda.

METHODS

Human keratinocytes were cultured in the presence or absence of the herbal extracts for 2 weeks; the effect of the extracts on cell growth was determined by staining the cells with Coomassie brilliant blue. To detect the compounds that regulate the growth of keratinocytes, the herbal extracts were subjected to high-performance liquid chromatography (HPLC).

RESULTS

We found that the extract of Emblica officinalis enhanced the growth of keratinocytes in culture. Further, we fractionated the extract of E. officinalis using HPLC and identified the fractions responsible for the enhanced growth of keratinocytes.

CONCLUSION

The extract of E. officinalis enhanced the growth of human keratinocytes in culture. E. officinalis contains the compounds that would be beneficial for human skin health because enhanced growth of keratinocytes would promote wound healing.

Effects of pruritogens and algogens on rostral ventromedial medullary ON and OFF cells

Rostroventromedial medulla (RVM) ON and OFF cells are thought to facilitate and inhibit spinal nociceptive transmission, respectively. However, it is unknown how ON and OFF cells respond to pruritic stimuli or how they contribute to descending modulation of spinal itch signaling. In pentobarbital sodium-anesthetized mice, single-unit recordings were made in RVM from ON and OFF cells identified by their respective increase or decrease in firing that occurred just before nocifensive hindlimb withdrawal elicited by paw pinch. Of RVM ON cells, 75% (21/28) were excited by intradermal histamine, 50% (10/20) by intradermal chloroquine, and 75% (27/36) by intradermal capsaicin. Most chemically responsive units also responded to a scratch stimulus applied to the injected hindpaw. Few ON cells responded to intradermal injection of vehicle (saline: 5/32; Tween 2/17) but still responded to scratching. For OFF cells, intradermal histamine and scratching inhibited 32% (6/19) with no effect of histamine in the remainder. Intradermal chloroquine inhibited 44% (4/9) and intradermal capsaicin inhibited 61% (11/18) of OFF cells. Few OFF cells were affected by vehicles (Tween: 1 inhibited, 7 unaffected; saline: 3 excited, 1 inhibited, 8 unaffected). Both ON and OFF cells that responded to one chemical usually also responded to others, whereas units unresponsive to the first-tested chemical tended not to respond to others. These results indicate that ascending pruriceptive signals activate RVM ON cells and inhibit RVM OFF cells. These effects are considered to facilitate and disinhibit spinal pain transmission, respectively. It is currently not clear if spinal itch transmission is similarly modulated. NEW & NOTEWORTHY The rostroventromedial medulla (RVM) contains ON and OFF cells that are, respectively, excited and inhibited by noxious stimuli and have descending projections that facilitate and inhibit spinal nociceptive transmission. Most RVM ON cells were excited, and OFF cells inhibited, by intradermal injection of the pruritogens histamine and chloroquine, as well as the algogen capsaicin. These results indicate that itchy stimuli activate RVM neurons that presumably give rise to descending modulation of spinal itch transmission.

Identification of patterns of factors preceding severe or life-threatening asthma exacerbations in a nationwide study

BACKGROUND

Reducing near-fatal asthma exacerbations is a critical problem in asthma management.

OBJECTIVES

To determine patterns of factors preceding asthma exacerbations in a real-world setting.

METHODS

In a nationwide prospective study of 190 patients who had experienced near-fatal asthma exacerbation, cluster analysis was performed using asthma symptoms over the 2-week period before admission.

RESULTS

Three distinct clusters of symptoms were defined employing the self-reporting of a visual analogue scale. Cluster A (42.1%): rapid worsening within 7.4 hours from moderate attack to admission, young to middle-aged patients with low Body mass index and tendency to depression who had stopped anti-asthma medications, smoked, and hypersensitive to environmental triggers and furred pets. Cluster B (40.0%): fairly rapid worsening within 48 hours, mostly middle-aged and older, relatively good inhaled corticosteroid (ICS) or ICS/long-acting beta-agonist (LABA) compliance, and low perception of dyspnea. Cluster C (17.9%): slow worsening over 10 days before admission, high perception of dyspnea, smokers, and chronic daily mild-moderate symptoms. There were no differences in overuse of short-acting beta-agonists, baseline asthma severity, or outcomes after admission for patients in these 3 clusters.

CONCLUSION

To reduce severe or life-threatening asthma exacerbation, personalized asthma management plans should be considered for each cluster. Improvement of ICS and ICS/LABA compliance and cessation of smoking are important in cluster A. To compensate for low perception of dyspnea, asthma monitoring of peak expiratory flow rate and/or exhaled nitric oxide would be useful for patients in cluster B. Avoidance of environmental triggers, increase usual therapy, or new anti-type 2 response-targeted therapies should be considered for cluster C.