Toll-like receptor 9 ligand blocks osteoclast differentiation through induction of phosphatase.

CpG-ODN, in addition to stimulation of osteoclastogenic signals in early osteoclast precursors, also induces phosphatase, shifting the pattern of ERK phosphorylation from sustained to transient. This shift results in the degradation of c-fos, an essential molecule for osteoclast differentiation. Therefore, CpG-ODN blocks osteoclast differentiation. INTRODUCTION: Activation of either Toll-like receptor 9 (TLR9) or RANK induces similar responses in osteoclast precursors. Paradoxically, activation of TLR9 results in inhibition of RANKL-induced osteoclastogenesis. MATERIALS AND METHODS: We used bone marrow-derived osteoclast precursors. Analyses of signaling molecules phosphorylation were performed using Western blotting. Different levels of gene expression analyses were performed using RT-PCR, Northern, and run-on analyses (for RNA), and EMSA, Western, and pulse-chase experiments (for protein). Phosphatase activity was measured spectrophotometrically. RESULTS: We found that RANKL and TLR9 ligand, oligodeoxynucleotides containing unmethylated CpG dinucleotides (CpG-ODN), induce sustained and transient extracellular signal-regulated kinase (ERK) phosphorylation, respectively. Furthermore, together they induce a transient phosphorylation of ERK. The duration of ERK phosphorylation is a key factor in determining induction of c-fos, a protein critical for osteoclastogenesis. Indeed, we found that CpG-ODN does not induce c-fos and inhibits its induction by RANKL by enhancing c-fos mRNA and protein degradation. Our observation that CpG-ODN, but not RANKL, induces the expression of the phosphatase PP2A suggests that CpG-ODN exerts its inhibitory activity by induction of ERK dephosphorylation. Moreover, together with the phosphatase inhibitor okadaic acid, CpG-ODN induces sustained ERK phosphorylation and c-fos expression. CONCLUSIONS: Our findings suggest that the increased rate of c-fos degradation by the TLR9 ligand mediates the inhibition of RANKL-induced osteoclast differentiation. The TLR9 ligand, through induction of dephosphorylation, prevents the sustained ERK phosphorylation needed for maintaining high c-fos levels that are essential for osteoclast differentiation.     

Effects of green tea polyphenols on murine transplant-reactive T cell immunity

Green tea polyphenols (GrTP), the active ingredient of green tea, may have immunosuppressive properties, but whether and how GrTP affect transplant-reactive T cells is unknown. To address this, we tested the effects of GrTP on in vitro and in vivo transplant-reactive T cell immunity. GrTP inhibited IFNgamma secretion by cultured monoclonal T cells and by alloreactive T cells in mixed lymphocyte reactions. Oral GrTP significantly prolonged minor antigen-disparate skin graft survival and decreased the frequency of donor-reactive interferon gamma-producing T cells in recipient secondary lymphoid organs compared to controls. In contrast to other hypothesized actions, oral GrTP did not alter dendritic cell trafficking to lymph nodes or affect metalloproteinase activity in the graft. This is the first report of an immunosuppressive effect of GrTP on transplant-reactive T cell immunity. The results suggest that oral intake of green tea could act as an adjunctive therapy for prevention of transplant rejection in humans.     

Posttraumatic Stress Disorder Following Myocardial Infarction: A Systematic Review

The objective of the present review is to provide an overview of existing research that has reported on the association between posttraumatic stress disorder (PTSD) and ischemic heart disease. Specific focus is given to the incidence of PTSD following myocardial infarction (MI). A systematic review using Preferred Reporting Items for Systematic reviews and Meta‐Analysis (PRISMA) guidelines was performed by searching four bibliographic databases: PubMed, PsychINFO, ScienceDirect, and ProQuest Dissertations and Theses. A total of 39 articles were included in this literature review. The results of these studies suggest that the occurrence of an acute cardiac event is likely to contribute to the development of PTSD. Not only is this type of psychiatric disorder associated with significant suffering and impaired quality of life, but it is also a predictor of an increased risk of recurrent adverse cardiovascular events and mortality. Screening, assessment, and treatment of PTSD and posttraumatic stress symptoms following a major cardiac event are critical for offsetting potential deleterious psychological and physical consequences.     

TNF-α gene polymorphisms: association with age-related macular degeneration in Russian population

AIM: To study polymorphisms in promotor regions of tumor necrosis factor (TNF)-α TNF-863A/C (rs1800630), TNF-308A/G (rs1800629), and TNF-238A/G (rs361525) in patients with age-related macular degeneration (AMD) and associations of complex TNF-α genotypes with AMD. METHODS: One hundred and two patients (82 women, 20 men; mean age 64.2±1.2y) with AMD and 100 healthy age- and sex-matched controls (82 women, 18 men; 60±1.4y) were included in the study. All subjects were Caucasian, all subjects and their parents were inhabitants of Russia. Genomic DNA was obtained from EDTA-preserved blood using the standard phenol-chloroform method. Polymorphisms were detected by polymerase chain reaction followed by the restriction fragment length polymorphism method. The following TNF-α genotypes were studied: TNF-α-238 AA, GA, GG, TNF-α-308 AA, GA, GG, TNF-α-863 AA, CA, CC. RESULTS: Differences in TNF-α-863 and TNF-α-238 genotypes frequencies in patients with AMD and healthy controls were not found. The distribution of TNF-α-308 AA and TNF-α-308 GA genotypes was significantly different between the studied group and the controls [odds ratios (OR) =0.22, P=0.0287 and OR=2.91, P=0.0063, respectively]. TNF-863CC/TNF-308GA and TNF-308GA/TNF-238GG genotypes were associated with the increased risk of AMD (OR=2.48, P=0.0332 and OR=2.51, P=0.0187, respectively). Five genotypes combinations appeared to be protective. CONCLUSION: In the present study, single nucleotide polymorphisms and complex polymorphisms of one of the key inflammatory cytokines TNF-α, and a number of significant associations of these polymorphisms with AMD in Russian population have been shown. Complex analysis of genotypes could be important in AMD risk factors detection and studying pathogenesis.     

Growth differences by school-age and adolescence according to in utero and peripartum antiretroviral therapy exposure among Ugandan children

In utero/peripartum antiretroviral (IPA) drug exposure in human immunodeficiency virus (HIV)-exposed children has established benefit for prevention of HIV mother-to-child-transmission but its association with height-for-age by adolescence is unknown. Hence we quantify IPA-associated growth differences at 6 to 18 years old among children with perinatally acquired HIV (CPHIV) infection and children HIV exposed but uninfected (CHEU) relative to children HIV unexposed and uninfected (CHUU). Cohort study. Kampala, Uganda. Two hundred thirty eight community controls and 490 children of women living with HIV born between 2000 and 2011 in a community were enrolled at 6 to 18 years of age and followed every 6 months for 1 year. Height-for-age determined at enrollment, 6 and 12 months after enrollment using the World Health Organization reference. IPA exposure was retrospectively determined from medical records and categorized as: no IPA, single-dose nevirapine with/without zidovudine (sdNVP ± AZT), sdNVP + AZT + lamivudine, or combination antiretroviral therapy (cART). Mean differences (β) with 95% confidence intervals (CIs) in height-for-age over 12 months were evaluated according to IPA exposure for CPHIV and CHEU and relative to CHUU using longitudinal linear mixed effects models adjusted for caregiver factors (sex, age, education, functioning in caregiving role, and lifetime adversity) in Statistical Analysis Software (v.9.4). Regardless of IPA type, CPHIV grew worse than CHUU by school-age/adolescence (β = −0.30, 95% CI: −0.48, −0.11). Relative to CHUU height-for-age was similar for CHEU exposed to sdNVP ± AZT (β = −0.16, 95% CI: −0.46, 0.14) and for CHEU exposed to sdNVP + AZT + lamivudine (β = 0.08, 95% CI: −0.20, 0.35). However, CHEU without any IPA exposure had lower height-for-age (β = −0.27, 95% CI: −0.52, −0.00) whereas CHEU with cART exposure had greater height-for-age (β = 0.41, 95% CI: 0.10, 0.71) in comparison with CHUU by 6 to 18 years old. Our findings suggest that CHEU may achieve height-for-age parity with CHUU by school-age and adolescent years- especially if provided benefit of effective cART in the peripartum period. However, CPHIV regardless of IPA exposure type and CHEU without IPA exposure remain at a disadvantage and will benefit from intervention to support their growth.     

Size and Shape’s Effects on the High-Pressure Behavior of WS2 Nanomaterials

Exploring the behavior of nanocrystals with varying shapes and sizes under high pressure is crucial to understanding the relationship between the morphology and properties of nanomaterials. In this study, we investigated the compression behaviors of WS₂ nanotubes (NT-WS₂) and fullerene-like nanoparticles (IF-WS₂) by in situ high-pressure X-ray diffraction (XRD) and Raman spectroscopy. It was found that the bulk modulus of NT-WS₂ is 81.7 GPa, which is approximately twice as large as that of IF-WS₂ (46.3 GPa). This might be attributed to the fact that IF-WS₂ with larger d-spacing along the c-axis and higher defect density are more compressible under isotropic pressure than NT-WS₂. Thus, the slender NT-WS₂ possess a more stable crystal structure than the IF-WS₂. Our findings reveal that the effects of morphology and size play crucial roles in determining the high-pressure properties of WS₂ nanoparticles, and provide significant insight into the relationship between structure and properties.