Porphyromonas endodontalis reactivates latent Epstein-Barr virus

AIM

To determine whether Porphyromonas endodontalis can reactivate latent Epstein-Barr virus (EBV).

METHODOLOGY

The concentrations of short-chain fatty acids (SCFAs) in P. endodontalis culture supernatants were determined using high-performance liquid chromatography. A promoter region of BamHI fragment Z leftward open reading frame 1 (BZLF-1), which is a transcription factor that controls the EBV lytic cycle, was cloned into luciferase expression vectors. Then, the luciferase assay was performed using P. endodontalis culture supernatants. Histone acetylation using Daudi cells treated with P. endodontalis culture supernatants was examined using Western blotting. BZLF-1 mRNA and BamHI fragment Z EB replication activator (ZEBRA) protein were also detected quantitatively using real-time polymerase chain reaction (PCR) and Western blotting. Surgically removed periapical granulomas were examined to detect P. endodontalis, EBV DNA, and BZLF-1 mRNA expression using quantitative real-time PCR. Statistical analysis using Steel tests was performed.

RESULTS

The concentrations of n-butyric acid in P. endodontalis culture supernatants were significantly higher than those of other SCFAs (P = 0.0173). Using B-95-8-221 Luc cells treated with P. endodontalis culture supernatants, the luciferase assay demonstrated that P. endodontalis induced BZLF-1 expression. Hyperacetylation of histones was also observed with the culture supernatants. BZLF-1 mRNA and ZEBRA protein were expressed by Daudi cells in a dose-dependent manner after the treatment with P. endodontalis culture supernatants. P. endodontalis and BZLF-1 in periapical granulomas were also detected. The expression levels of BZLF-1 mRNA were similar to the numbers of P. endodontalis cells in each specimen.

CONCLUSIONS

n-butyric acid produced by P. endodontalis reactivated latent EBV.

A potential role for the silent information regulator 2 homologue 1 (SIRT1) in periapical periodontitis

AIM

To investigate the role played by silent information regulator 2 homologue 1 (SIRT1) during angiogenesis of periapical periodontitis.

METHODOLOGY

Periapical granulomas were subjected to dual-colour immunofluorescence imaging and real-time polymerase chain reactions assaying the expression levels of SIRT1, vascular endothelial growth factor (VEGF) and VE-cadherin. The association between Ki-67 and SIRT1 expression was also examined. Human umbilical vein endothelial cells (HUVECs) were treated with a combination of lipopolysaccharide and resveratrol (a SIRT1 activator) or sirtinol (a SIRT1 inhibitor); and the levels of mRNAs encoding SIRT1, VEGF and VE-cadherin were determined. HUVEC tube formation was assayed in the presence of resveratrol or sirtinol. The Mann-Whitney U-test or the Tukey-Kramer test was used for statistical analysis.

RESULTS

Ki-67-expressing cells, including endothelial cells, lay adjacent to SIRT1-expressing cells in periapical granulomas. In addition, SIRT1-expressing cells were detected adjacent to VEGF-expressing cells and VEGF- or VE-cadherin-expressing endothelial cells. SIRT1, VEGF and VE-cadherin mRNA expression levels in periapical granulomas were significantly higher (P = 0.0054, 0.0090 and 0.0090, respectively) than those in healthy gingival tissues. HUVECs treated with resveratrol exhibited significantly higher expression of mRNAs encoding SIRT1, VEGF and VE-cadherin (P = 0.0019, 0.00005 and 0.0045, respectively) compared with controls, but sirtinol inhibited such expression. Resveratrol caused HUVECs to form tube-like structures, whilst sirtinol inhibited this process.

CONCLUSIONS

These findings suggest that SIRT1 may stimulate angiogenesis in periapical granulomas by triggering the proliferation of endothelial cells and inducing VEGF and VE-cadherin expression.

Do scleroderma patients look young?: Evaluation by using facial imaging system

These days various collagen supplements have widely been marketed. However, it has not been scientifically proved whether increasing collagen can actually prevent skin aging. Systemic sclerosis (SSc) is an autoimmune disease that is characterized by thickening of the skin caused by accumulation of collagen. In this study, we tried to evaluate facial skin characteristics and skin aging of SSc patients by using digital imaging system. As the result, the severity of wrinkles, texture and pores were significantly lower in SSc patients than control subjects. Among them, wrinkles showed better correlation with skin thickness score. Therefore, increased amount of collagen in scleroderma skin may directly affect wrinkles. In conclusion, attempt on collagen induction itself is reasonable and effective strategy in order to keep young appearance, although oral collagen supplementation may not directly reach to the skin.

Long and Short Sleep Duration and Physical Frailty in Community-Dwelling Older Adults

OBJECTIVE

The objective of this study was to investigate whether older adults who have a particularly long sleep duration are likely to exhibit physical frailty, similar to those with a particularly short sleep duration.

DESIGN

Cross-sectional study.

SETTING

The National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes.

PARTICIPANTS

A total of 9,824 older adults (mean age: 73.6 ± 5.5 years, 4,812 men and 5,012 women) met the entry criteria for this study.

MEASUREMENTS

We divided the participants into three groups according to self-reported sleep duration (Short: ≤6 h, Mid: 6.1-8.9 h (control), Long: ≥ 9 h). Physical frailty was characterized based on the criteria from the Cardiovascular Health Study. Multinomial logistic regression analysis was performed to evaluate the effect of sleep duration on physical frailty by sex.

RESULTS

Among all participants, the prevalence of physical frailty was higher in the Short (10.5%) and Long (17.9%) groups than in the Mid (7.4%) group (p < 0.001). Multinomial logistic regression analysis showed that both Short and Long groups had a significantly higher odds ratio (OR) for physical frailty than the Mid group [Short: OR 1.53, 95% confidence interval (CI) 1.26-1.87; Long: OR 2.39, 95% CI 1.90-3.00], even after adjusting for age, educational level, number of medications, body mass index, Mini Mental State Examination score, current smoking and alcohol habits, self-perceived health, and medical history.

CONCLUSION

Both long and short sleep durations were associated with physical frailty. Further studies are required to confirm the effect of sleep duration on the incidence or worsening of physical frailty in older adults.

Cognitive Frailty is Associated with Fall-Related Fracture among Older People

OBJECTIVE

Cognitive frailty refers to cognitive impairment and physical frailty. Both cognitive impairment and physical frailty include risks of falling. The purpose of the study is to examine cognitive frailty and falling with/without a fracture.

DESIGN

Cross-sectional observation study.

SETTING

General communities in Japan.

PARTICIPANTS

Data of 10,202 older adults aged ≥ 65 years were collected.

MEASUREMENTS

Physical frailty was characterized as slow walking speed and/or muscle weakness. Assessment of cognitive function included word lists memory, attention, executive function, and processing speed. Cognitive impairment refers to one or more cognitive decline indicated by at least 1.5 standard deviations below the threshold after adjusting for age and education. We operationally defined cognitive frailty as having both cognitive impairment and physical frailty. Participants were interviewed about their falling, history of fall-related fractures, and several potentially confounding factors such as demographic characteristics.

RESULTS

Multinomial logistic regression analysis revealed that functional decline in all groups, as compared to the robust group, was significantly associated with falling without fractures, after adjusting for the covariates; cognitive impairment group (P = .017), physical frailty group (P = .002), and cognitive frailty group (P < .001). Only the cognitive frailty group had a significant association with fall-related fracture after adjusting for the covariates (OR 1.92, 95% CI: 1.20-3.08, P = .007).

CONCLUSION

Cognitive frailty is associated with not only falling but also fall-related fractures. Cognitive frailty may have a greater risk for fall-related fractures than cognitive impairment or physical frailty alone. Future research should examine causal the relationship between fall-related fractures and cognitive frailty.

Association between Insulin-Like Growth Factor-1 and Frailty among Older Adults

OBJECTIVES

Frailty is a course experienced in advanced aging. Identification of a biological factor associated with frailty is required. Although serum insulin-like growth factor-1 (IGF-1) is a potential factor related with frailty, consensus has not been reached regarding this relationship. This study aimed to investigate the association between IGF-1 and frailty in older adults.

DESIGN

Cross-sectional study.

SETTING

Cohort study that was part of the "National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes."

PARTICIPANTS

The study participants were 4133 older adults (mean age, 71.8 ± 5.4 years).

MEASUREMENTS

We assessed serum IGF-1 levels and frailty status and collected demographic variables, including cognitive function, as covariates.

RESULTS

Frailty and pre-frailty were present in 274 subjects (7%) and 1930 subjects (47%), respectively. Subjects were divided into four groups based on quartiles of IGF-1 levels. Multinomial logistic analysis showed that the lowest group had significant odds of pre-frailty (crude model: odds ratio [OR] 1.58, 95% confidence interval [CI] 1.30-1.90, p < .001; adjusted model: OR 1.38, 95% CI 1.13-1.68, p = .002) and frailty (crude model: OR 3.42, 95% CI 2.38-4.92, p < .001; adjusted model: OR 1.54, 95% CI 1.02-2.32, p = .039), compared with the highest group.

CONCLUSION

Lower serum IGF-1 levels were independently related with frailty in older adults.

Active control of bright electron beams with RF optics for femtosecond microscopy

A frontier challenge in implementing femtosecond electron microscopy is to gain precise optical control of intense beams to mitigate collective space charge effects for significantly improving the throughput. Here, we explore the flexible uses of an RF cavity as a longitudinal lens in a high-intensity beam column for condensing the electron beams both temporally and spectrally, relevant to the design of ultrafast electron microscopy. Through the introduction of a novel atomic grating approach for characterization of electron bunch phase space and control optics, we elucidate the principles for predicting and controlling the phase space dynamics to reach optimal compressions at various electron densities and generating conditions. We provide strategies to identify high-brightness modes, achieving ∼100 fs and ∼1 eV resolutions with 10⁶ electrons per bunch, and establish the scaling of performance for different bunch charges. These results benchmark the sensitivity and resolution from the fundamental beam brightness perspective and also validate the adaptive optics concept to enable delicate control of the density-dependent phase space structures to optimize the performance, including delivering ultrashort, monochromatic, high-dose, or coherent electron bunches.

Anti-connective tissue growth factor (CTGF/CCN2) monoclonal antibody attenuates skin fibrosis in mice models of systemic sclerosis

Background

Systemic sclerosis (SSc) is characterized by fibrosis of the skin and internal organs. Although the involvement of connective tissue growth factor (CTGF/CCN2) has been well-documented in SSc fibrosis, the therapeutic potential of targeting CTGF in SSc has not been fully investigated. Our aim was to examine the therapeutic potential of CTGF blockade in a preclinical model of SSc using two approaches: smooth muscle cell fibroblast-specific deletion of CTGF (CTGF knockout (KO)) or a human anti-CTGF monoclonal antibody, FG-3019.

Methods

Angiotensin II (Ang II) was administered for 14 days by subcutaneous osmotic pump to CTGF KO or C57BL/6 J mice. FG-3019 was administered intraperitoneally three times per week for 2 weeks. Skin fibrosis was evaluated by histology and hydroxyproline assay. Immunohistochemistry staining was used for alpha smooth muscle actin (αSMA), platelet-derived growth factor receptor β (PDGFRβ), pSmad2, CD45, von Willebrand factor (vWF), and immunofluorescence staining was utilized for procollagen and Fsp1.

Results

Ang II-induced skin fibrosis was mitigated in both CTGF KO and FG-3019-treated mice. The blockade of CTGF reduced the number of cells expressing PDGFRβ, procollagen, αSMA, pSmad2, CD45, and Fsp1 in the dermis. In addition, inhibition of CTGF attenuated vascular injury as measured by the presence of vWF-positive cells.

Conclusions

Our data indicate that inhibition of CTGF signaling presents an attractive therapeutic approach in SSc.

Blockade of PDGF Receptors by Crenolanib Has Therapeutic Effect in Patient Fibroblasts and in Preclinical Models of Systemic Sclerosis

Systemic sclerosis (SSc) is a multi-organ fibrotic disease with few treatment options. Activated fibroblasts are the key effector cells in SSc responsible for the excessive production of collagen and the development of fibrosis. Platelet-derived growth factor (PDGF), a potent mitogen for cells of mesenchymal origin, has been implicated in the activation of SSc fibroblasts. Our aim was to examine the therapeutic potential of crenolanib, an inhibitor of PDGF receptor signaling, in cultured fibroblasts and in angiotensin II-induced skin and heart fibrosis. Crenolanib effectively inhibited proliferation and migration of SSc and healthy control fibroblasts and attenuated basal and transforming growth factor-β-induced expression of CCN2/CTGF and periostin. In contrast to healthy control fibroblasts, SSc fibroblasts proliferated in response to PDGFAA, whereas a combination of PDGFAA and CCN2 was required to elicit a similar response in healthy control fibroblasts. PDGF receptor α mRNA correlated with CCN2 and other fibrotic markers in the skin of SSc patients. In mice challenged with angiotensin II, PDGF receptor α-positive cells were increased in the skin and heart. These PDGF receptor α-positive cells co-localized with PDGF receptor β, procollagen, and periostin. Treatment with crenolanib attenuated the skin and heart fibrosis. Our data indicate that inhibition of PDGF signaling presents an attractive therapeutic approach for SSc.