Phenolic acids prevent sex-steroid deficiency-induced bone loss and bone marrow adipogenesis in mice

Phenolic acids, such as hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA), can be produced from microbiome digestion of polyphenols. Previously it was found that HA and 3-3-PPA facilitate bone formation and suppress bone resorption. However, the mechanism of action by which HA and 3-3-PPA protect bone from degeneration is currently unknown. In this report, we present that HA and 3-3-PPA suppression of bone resorption is able to ameliorate bone loss in an ovariectomy (OVX) osteopenic mouse model though not to the extent of Zoledronic acid (ZA). HA and 3-3-PPA treatments were shown to significantly decrease bone marrow adipocyte-like cell formation and inhibited gene expression of key adipogenesis regulator peroxisome proliferator activated receptor gamma (PPARγ) and lipoprotein lipase (Lpl) in bone from OVX mice. In addition, ChIP experiments showed that the association between PPARγ and Lpl promoter region in preadipocyte-like cells was significantly suppressed following HA or 3-3-PPA treatment. Contrasting HA and 3-3-PPA, ZA significantly increased TRAP activity in the area close to growth plate and significantly suppressed bone cell proliferation. These data suggest that phenolics acids such as HA or 3-3-PPA may prevent bone degeneration after OVX through suppression of inflammatory milieu in the bone.

BCMA- and CST6-specific CAR T cells lyse multiple myeloma cells and suppress murine osteolytic lesions

We have previously demonstrated that cystatin E/M (CST6), which is elevated in a subset of patients with multiple myeloma (MM) lacking osteolytic lesions (OLs), suppresses MM bone disease by blocking osteoclast differentiation and function. CST6 is a secreted type 2 cystatin, a cysteine protease inhibitor that regulates lysosomal cysteine proteases and the asparaginyl endopeptidase legumain. Here, we developed B cell maturation antigen (BCMA) CST6 chimeric antigen receptor T cells (CAR-T cells), which lysed MM cells and released CST6 proteins. Our in vitro studies show that these CAR-T cells suppressed the differentiation and formation of tartrate-resistant acid phosphatase-positive (TRAP+) osteoclasts. Using xenografted MM mice, bioluminescence images showed that both BCMA-CAR-T and BCMA-CST6-CAR-T cells inhibited MM growth to a similar extent. Reconstructed micro-computed tomography images revealed that BCMA-CST6-CAR-T cells, but not BCMA-CAR-T cells, prevented MM-induced bone damage and decreased osteoclast numbers. Our results provide a CAR-T strategy that targets tumor cells directly and delivers an inhibitor of bone resorption.

High NEK2 expression in myeloid progenitors suppresses T cell immunity in multiple myeloma

Multiple myeloma (MM) growth is supported by an immune-tolerant bone marrow microenvironment. Here, we find that loss of Never in mitosis gene A (NIMA)-related kinase 2 (NEK2) in tumor microenvironmental cells is associated with MM growth suppression. The absence of NEK2 leads to both fewer tumor-associated macrophages (TAMs) and inhibitory T cells. NEK2 expression in myeloid progenitor cells promotes the generation of functional TAMs when stimulated with MM conditional medium. Clinically, high NEK2 expression in MM cells is associated with increased CD8+ T effector memory cells, while low NEK2 is associated with an IFN-γ gene signature and activated T cell response. Inhibition of NEK2 upregulates PD-L1 expression in MM cells and myeloid cells. In a mouse model, the combination of NEK2 inhibitor INH154 with PD-L1 blockade effectively eliminates MM cells and prolongs survival. Our results provide strong evidence that NEK2 inhibition may overcome tumor immune escape and support its further clinical development.

Effect of phosphorus doping on the luminescence intensity of Si-NC in SiO/Si multilayers

The application of silicon nanocrystals (Si-NC) is somewhat limited due to their low luminescence intensity. Therefore, it is of interest to investigate methods for enhancing the luminescence intensity of Si-NC. In this study, phosphorus (P)-doped Si-NC with two different doping methods were prepared by electron beam thermal evaporation: in-situ doping (during synthesis) and ex-situ doping (after synthesis). The photoluminescence (PL) intensity and crystallinity of Si-NC can be enhanced through phosphorus doping. Moreover, a comparison between two different methods of Si-NC doping reveals that the luminescence intensity of in-situ P-doped Si-NC is superior to that of ex-situ P-doped Si-NC, which is increased by an order of magnitude compared to the PL intensity of undoped Si-NC.

Decreased bone resorption in Ezh2 myeloid cell conditional knockout mouse model

Osteoclasts derived from hematopoietic stem cells control bone resorption. Identifying novel molecules that can epigenetically regulate osteoclastogenesis is important for developing novel treatments for osteoporosis and other disorders associated with bone deterioration and promoting healthy bone formation. The polycomb group (PcG) protein enhancer of zeste homolog 2 (Ezh2), a histone lysine methyltransferase, is associated with epigenetic regulation of numerous cellular processes, but its involvement in bone cell development and homeostasis is not yet clear. Here, LysM-Cre mice were crossed with Ezh2^flox/flox mice to delete Ezh2 in myeloid cell lineage mature macrophages. Conditional knockout of Ezh2 (CKO) in myeloid cell line resulted in significant increases in postnatal bone growth in the first 6 months of life for both male and female mice. For female mice, optimal bone mass was seen for mice with Ezh2 deleted in both chromosomes in a pair (f/f Cre⁺ ; CKO). For male mice, optimal bone mass was found after deletion of Ezh2 from just one chromosome (f/- Cre⁺ ) with no difference in bone phenotype between f/- Cre⁺ and CKO male mice. In addition to the gender-specific difference in bone phenotype, Ezh2 CKO mice had significantly less macrophages (CD11b+) present in the bone marrow compared with control mice as well as significantly more mature osteoblasts and bone formation biomarkers present (P1NP, osteocalcin). Inflammatory array for protein lysed from bone tissue revealed deletion of Ezh2 decreased inflammatory milieu in both male and female mice compared with controls. Unexpectedly, myeloid cell deletion of Ezh2 also increased the number of mature osteoblast present in the bone. Deletion of Ezh2 also led to an increase in gene expression of osteoclast-suppressive genes IRF8, MafB, and Arg1 due to a decrease in the presence of the suppressive H3K27me3 epigenetic mark. These findings suggest that manipulation of Ezh2 expression may be a viable strategy to combat bone resorptive disorders such as osteoporosis or arthritis.

A gene signature can predict risk of MGUS progressing to multiple myeloma

Multiple myeloma is preceded by monoclonal gammopathy of undetermined significance (MGUS). Serum markers are currently used to stratify MGUS patients into clinical risk groups. A molecular signature predicting MGUS progression has not been produced. We have explored the use of gene expression profiling to risk-stratify MGUS and developed an optimized signature based on large samples with long-term follow-up. Microarrays of plasma cell mRNA from 334 MGUS with stable disease and 40 MGUS that progressed to MM within 10 years, was used to define a molecular signature of MGUS risk. After a three-fold cross-validation analysis, the top thirty-six genes that appeared in each validation and maximized the concordance between risk score and MGUS progression were included in the gene signature (GS36). The GS36 accurately predicted MGUS progression (C-statistic is 0.928). An optimal cut-point for risk of progression by the GS36 score was found to be 0.7, which identified a subset of 61 patients with a 10-year progression probability of 54.1%. The remainder of the 313 patients had a probability of progression of only 2.2%. The sensitivity and specificity were 82.5% and 91.6%. Furthermore, combination of GS36, free light chain ratio and immunoparesis identified a subset of MGUS patients with 82.4% risk of progression to MM within 10 years. A gene expression signature combined with serum markers created a highly robust model for predicting risk of MGUS progression. These findings strongly support the inclusion of genomic analysis in the management of MGUS to identify patients who may benefit from more frequent monitoring.

A Longitudinal Observational Study of Skeletal Development Between Ages 3 Months and 6 Years in Children Fed Human Milk, Milk Formula or Soy Formula

BACKGROUND

Early infant feeding can impact skeletal development. Most children are fed breast milk (BF), dairy based infant formula (MF), or soy based infant formula (SF) during the first year of life. The National Health and Nutrition Examination Survey 2003-2010 reports that 12% of U.S. infants consume soy-based infant formula. Despite potential effects of soy-associated isoflavones on skeletal development, studies investigating bone metabolism and structural and functional bone indices in children are lacking.

OBJECTIVE

The aim of this observational study was to investigate early effects of SF intake on bone metabolism and structure during the first 6 years of life by comparing infants fed BF, MF, or SF.

DESIGN

A total of 433 healthy infants were followed from 3 months to 6 years of age. Children's skeletal development was assessed using dual-energy X-ray absorptiometry (DXA, N=433) and peripheral quantitative computed tomography (pQCT, N=78). Urinary biomarkers of bone metabolism (N-terminal telopeptide of type I collagen [NTx] and osteocalcin) were evaluated by immunoassays at 6, 24, 60 and 72 months.

RESULTS

No statistically significant group differences were observed in BMD between children who were BF, MF or SF using DXA or pQCT. At 6 years of age, children who consumed SF in infancy had significantly greater whole- body BMC measured by DXA compared to the MF group. Six-month-old SF boys had significantly greater levels of NTx compared to MF boys, as well as significantly greater osteocalcin levels compared to BF boys.

CONCLUSIONS

Together, these data suggest that while SF infants at age 6 months may have some enhanced bone metabolism compared to BF and MF infants, as indicated by the urinary biomarkers, no differences in bone metabolism or BMD were noted between ages 2 and 6 years.

CLINICAL TRIAL REGISTRY NUMBER

NCT00616395; https://clinicaltrials.gov/ct2/show/NCT00616395.

Maternal high-fat diet modifies epigenetic marks H3K27me3 and H3K27ac in bone to regulate offspring osteoblastogenesis in mice

Studies from both humans and animal models indicated that maternal chronic poor-quality diet, especially a high fat diet (HFD), is significantly associated with reduced bone density and childhood fractures in offspring. When previously studied in a rat model, our data suggested that maternal HFD changes epigenetic marks such as DNA methylation and histone modifications to control osteoblast metabolism. In mouse embryonic and postnatal offspring bone samples, a ChIP-sequencing (ChIP-Seq)-based genome-wide method was used to locate the repressive histone mark H3K27me3 (mediated via the polycomb histone methyltransferase, Ezh2) and expressive histone mark H3K27ac (p300/CBP mediated) throughout the genome. Using isolated mouse embryonic cells from foetal calvaria (osteoblast-like cells), H3K27me3 ChIP-Seq showed that 147 gene bodies and 26 gene promoters in HFD embryotic samples had a greater than twofold increase in H3K27me peaks compared to controls. Among the HFD samples, Pthlh and Col2a1 that are important genes playing roles during chondro- and osteogenesis had significantly enriched levels of H3K27me3. Their decreased mRNA expression was confirmed by real-time PCR and standard ChIP analysis, indicating a strong association with Ezh2 mediated H3K27me3 epigenetic changes. Using embryonic calvaria osteoblastic cells and offspring bone samples, H3K27ac ChIP-Seq analysis showed that osteoblast inhibitor genes Tnfaip3 and Twist1 had significantly enriched peaks of H3K27ac in HFD samples compared to controls. Their increased gene expression and association with H3K27ac were also confirmed by real-time PCR and standard ChIP analysis. These findings indicate that chronic maternal HFD changes histone trimethylation and acetylation epigenetic marks to regulate expression of genes controlling osteoblastogenesis.

GPR109A gene deletion ameliorates gonadectomy-induced bone loss in mice

Sex steroid deficiency plays critical roles in the pathophysiology of bone as the result of uncertain bone remodeling, i.e., increased bone resorption with equivocal bone formation. We have previously shown that GPR109A, a G protein coupled receptor, controls osteoclastogenesis and bone resorption, where global GPR109A deletion decreased osteoclast bone resorption and increased bone mass. Here, we used global GPR109A gene deletion, ovariectomized (OVX) and orchidectomized (ORX) mouse models to probe the role of GPR109A in gonadectomy-induced bone loss in female and male mice. Six months old GPR109A^-/- mice and their wild type littermates were allocated to Sham or gonadectomized groups for six weeks. Using densitometric micro-CT confirmed by peripheral quantitative CT (pQCT) scans on tibia and spine, and three-point bending test on femur ex vivo, we found the bone volume, trabecular number, as well as bone mineral density and content in both trabecular and cortical sites were significantly decreased in wild type OVX and ORX compared with respective Sham groups. While bone mass in both male and female GPR109A^-/- Sham groups were significantly higher compared with their respective wild type Sham groups, global GPR109A gene deletion ameliorated gonadectomy-induced bone loss. In GPR109A^-/- females, most of bone mass and strength parameters measured by micro-CT, pQCT and three-point bending test were not different between Sham and OVX groups. In wild type but not in GPR109^-/- mice, bone remodeling marker measurements indicated that both bone resorption (Cathepsin K) and bone formation (osteocalcin) markers were increased in gonadectomized mice compared to sham, with the exception of bone specific ALP, which was decreased in gonadectomized mice. Expression of bone resorption markers (Cathepsin K) were significantly lower, but β-catenin expression was higher in GPR109A^-/- mice compared with their wild type littermates. Collectively, these data indicate that global GPR109A deletion ameliorates gonadectomy-induced bone loss through suppression of bone resorption.

CST6 suppresses osteolytic bone disease in multiple myeloma by blocking osteoclast differentiation

Osteolytic bone disease is a hallmark of multiple myeloma (MM). A significant fraction (~20%) of MM patients do not develop osteolytic lesions (OL). The molecular basis for the absence of bone disease in MM is not understood. We combined PET-CT and gene expression profiling (GEP) of purified bone marrow (BM) CD138+ MM cells from 512 newly diagnosed MM patients to reveal that elevated expression of cystatin M/E (CST6) was significantly associated with the absence of OL in MM. An enzyme-linked immunosorbent assay revealed a strong correlation between CST6 levels in BM serum/plasma and CST6 mRNA expression. Both recombinant CST6 protein and BM serum from patients with high CST6 significantly inhibited the activity of the osteoclast-specific protease cathepsin K, and blocked osteoclast differentiation and function. Recombinant CST6 inhibited bone destruction in ex vivo and in vivo myeloma models. Single cell RNA-sequencing identified that CST6 attenuates polarization of monocytes to osteoclast precursors. Furthermore, CST6 protein blocks osteoclast differentiation by suppressing cathepsin-mediated cleavage of NF-κB/p100 and TRAF3 following RANKL stimulation. Secretion by MM cells of CST6, an inhibitor of osteoclast differentiation and function, suppresses osteolytic bone disease in MM and probably other diseases associated with osteoclast-mediated bone loss.

Nox4 expression in osteo-progenitors controls bone development in mice during early life

Tightly regulated and cell-specific NADPH-oxidases (Nox) represent one of the major sources of reactive oxygen species (ROS) signaling molecules that are involved in tissue development and stem cell self-renewal. We have characterized the role of Nox4 in osteo-progenitors during postnatal bone development. Nox4 expression in bone and ROS generation were increased during early osteoblast differentiation and bone development. Stromal osteoblastic cell self-renewal, proliferation and ROS production were significantly lower in samples from whole-body Nox4 knockout mice (Nox4^-/-) and conditional knockout (CKO) mice with depletion of Nox4 in the limb bud mesenchyme compared with those from control mice (Nox4^fl/fl), but they were reversed after 9 passages. In both sexes, bone volume, trabecular number and bone mineral density were significantly lower in 3-week old CKO and Nox4^-/- mice compared with Nox4^fl/fl controls. This was reflected in serum levels of bone formation markers alkaline phosphatase (ALP) and procollagen 1 intact N-terminal propeptide (P1NP). However, under-developed bone formation in 3-week old CKO and Nox4^-/- mice quickly caught up to levels of control mice by 6-week of age, remained no different at 13-week of age, and was reversed in 32-week old male mice. Osteoclastogenesis showed no differences among groups, however, CTX1 reflecting osteoclast activity was significantly higher in 3-week old male CKO and Nox4^-/- mice compared with control mice, and significantly lower in 32-week old Nox4^-/- mice compared with control mice. These data suggest that Nox4 expression and ROS signaling in bone and osteoblastic cells coordinately play an important role in osteoblast differentiation, proliferation and maturation.

Binge Ethanol Exposure in Mice Represses Expression of Genes Involved in Osteoblast Function and Induces Expression of Genes Involved in Osteoclast Differentiation Independently of Endogenous Catalase

Excessive ethanol consumption is a risk factor for osteopenia. Since a previous study showed that transgenic female mice with overexpression of catalase are partially protected from ethanol-mediated trabecular bone loss, we investigated the role of endogenous catalase in skeletal ethanol toxicity comparing catalase knockout to wild-type mice. We hypothesized that catalase depletion would exacerbate ethanol effects. The mice were tested in a newly designed binge ethanol model, in which 12-week-old mice were exposed to 4 consecutive days of gavage with ethanol at 3, 3, 4, and 4.5 g ethanol/kg body weight. Binge ethanol decreased the concentration of serum osteocalcin, a marker of bone formation. The catalase genotype did not affect the osteocalcin levels. RNA sequencing of femoral shaft RNA from males was conducted. Ethanol exposure led to significant downregulation of genes expressed in cells of the osteoblastic lineage with a role in osteoblastic function and collagen synthesis, including the genes encoding major structural bone proteins. Binge ethanol further induced a smaller set of genes with a role in osteoclastic differentiation. Catalase depletion affected genes with expression in erythroblasts and erythrocytes. There was no clear interaction between binge ethanol and the catalase genotype. In an independent experiment, we confirmed that the binge ethanol effects on gene expression were reproducible and occurred throughout the skeleton in males. In conclusion, the binge ethanol exposure, independently of endogenous catalase, reduces expression of genes involved in osteoblastic function and induces expression of genes involved in osteoclast differentiation throughout the skeleton in males.

GPR109A mediates the effects of hippuric acid on regulating osteoclastogenesis and bone resorption in mice

The G protein-coupled receptor 109 A (GPR109A) is robustly expressed in osteoclastic precursor macrophages. Previous studies suggested that GPR109A mediates effects of diet-derived phenolic acids such as hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA) on promoting bone formation. However, the role of GPR109A in metabolic bone homeostasis and osteoclast differentiation has not been investigated. Using densitometric, bone histologic and molecular signaling analytic methods, we uncovered that bone mass and strength were significantly higher in tibia and spine of standard rodent diet weaned 4-week-old and 6-month-old GPR109A gene deletion (GPR109A-/-) mice, compared to their wild type controls. Osteoclast numbers in bone and in ex vivo bone marrow cell cultures were significantly decreased in GPR109A-/- mice compared to wild type controls. In accordance with these data, CTX-1 in bone marrow plasma and gene expression of bone resorption markers (TNFα, TRAP, Cathepsin K) were significantly decreased in GPR109A-/- mice, while on the other hand, P1NP was increased in serum from both male and female GPR109A-/- mice compared to their respective controls. GPR109A deletion led to suppressed Wnt/β-catenin signaling in osteoclast precursors to inhibit osteoclast differentiation and activity. Indeed, HA and 3-3-PPA substantially inhibited RANKL-induced GPR109A expression and Wnt/β-catenin signaling in osteoclast precursors and osteoclast differentiation. Resultantly, HA significantly inhibited bone resorption and increased bone mass in wild type mice, but had no additional effects on bone in GPR109A-/- mice compared with their respective untreated control mice. These results suggest an important role for GPR109A during osteoclast differentiation and bone resorption mediating effects of HA and 3-3-PPA on inhibiting bone resorption during skeletal development.

[Application of multiple exposure assessment methods in occupational health risk assessment of trichloroethylene in electroplating enterprises]

Objective: To explore the applicability of different exposure assessment methods in occupational health risk assessment of trichloroethylene (TCE) occupation posts in electroplating enterprise. Methods: In November 2018, the occupational health risk assessments are conducted in trichloroethylene (TCE) occupation posts of 6 metal plating enterprises in a street in Shenzhen by using the qualitative risk assessment, semi-quantitative risk assessment (including contact ratio method, contact index method and synthesis index method) and quantitative risk assessment method (including non-carcinogenic and carcinogenic risk assessment methods) , and the results of different methods are compared. Results: The results of qualitative assessment method are all level 4 (high risk) ; the results of contact ratio method show that the risk level is level 5 (very high risk) ; the results of contact index method and Synthesis index method show that the risk level is level 3 and level 4, 66.7% and 33.3% respectively; Non-carcinogenic risk assessment results show that TCE jobs are "unacceptable"; carcinogenic risk assessment results in carcinogenic inhalation excess risk of 50% each being "unacceptable" and "acceptable". The results of the six risk assessment methods showed that there were 3 "substantially consistent", 1 "partially consistent", and 2 "inconsistent" among the 6 companies. Conclusion: Synthesis index method and the carcinogenic risk assessment method are more suitable for occupational health risks of TCE occupation posts.

Increased Physical Activity During Early Life Exacerbates High Fat Diet-Induced Bone Loss in Adult Mice

Objectives

It has been recognized that mechanical stresses associated with physical activity (PA) have beneficial effects on increasing bone mineral density (BMD) and improving bone quality in humans and animal models. On the other hand, in rodents, high fat diet (HFD) and obesity increase bone marrow adiposity leading to increased production of pro-inflammatory cytokines that activate RANKL-induced bone resorption. In the current study, we investigated whether short-term increased PA via access to voluntary wheel running during early life has persistent effects on HFD-induced bone resorption.

Methods

Sixty (60) four-week-old male C57BL6/J mice were divided into two groups; without or with PA, access to voluntary running wheel (7 to 8 km per day) for 4 wks, with ad libitum access to control diet for all animals. After 4 wks with or without PA, mice were further subdivided into control diet or HFD groups for 8 wks, before all animals were switched back to control diet for an additional 4 wks. Mice from the HFD groups were significantly heavier, with more adiposity vs. control group at the 12 wk study time point, and returned to levels of mice with continues control diet at the 16 wk study time point.

Results

Using peripheral quantitative CT (pQCT) and micro-CT scan on tibias ex vivo, we determined that trabecular BMD and bone volume were significantly increased in animals after 4 wks of PA and control diet compared to sedentary animals without access to wheels. Eight weeks of HFD deteriorated bone development in mice, micro-CT showed 9% significant reduction on percentage of bone volume, and pQCT analysis showed 6% significant reduction of trabecular bone density of mice compared with those standard diet mice. Unexpectedly, early life PA exacerbated HFD-induced trabecular bone loss in adult mice. Early life PA accelerated HFD-induced osteoclastogenesis in adult mice. In accordance with these data, signal transduction studies revealed that HFD-induced Ezh2 and NFATc1, and IRF8 expression were amplified in non-adherent hematopoietic cells.

Conclusions

Increased PA in early life is capable of increasing bone mass; however, it alters the HFD-induced bone marrow hematopoietic cell differentiation program to exacerbate bone resorption if PA is halted.

Funding Sources

Supported in part by USDA-ARS Project 6026–51,000-010–05S.

Children's liking and wanting of foods vary over multiple bites/sips of consumption: A case study of foods containing wild blueberry powder in the amounts targeted to deliver bioactive phytonutrients for children

To encourage children to frequently consume wild blueberries as part of their dietary patterns, incorporating blueberry powder into specific foods may be an effective strategy. Thus, it is important to determine appropriate types of food products that both minimize food processing-induced loss of beneficial components of blueberries (e.g., anthocyanins) and satisfy at the same time both nutritional and sensory aspects. For clinical studies assessing the health benefits of blueberry-containing food samples, it would be important to ensure children consume the entire portion of the test samples. This study, therefore, aimed at determining how sensory acceptability (liking) and psychological reward (wanting) of wild blueberry-based foods vary over multiple steps of ad libitum consumption: appearance, first bite/sip, half bite/sip, and full consumption. Five different types of foods containing the targeted amount of wild blueberry powder were prepared for sensory testing (oatmeal bar, beverage, ice pop, gummy, and cookie), and the residual amounts of total anthocyanin and chlorogenic acid were measured to confirm levels targeted to deliver bioactive amounts of these phytochemicals. Results showed that while overall liking and desire to eat did not differ among the five samples at the appearance and first bite/sip steps, they differed significantly at the end of consumption. Although children liked and wanted to consume the cookies more when compared to beverages, ice pops, and/or gummies, total anthocyanin contents were lower in cookies and gummies than in wild blueberry powder, beverage, and ice pop samples. Notably, the oatmeal bars with significant amounts of total anthocyanin and chlorogenic acid did not significantly differ from the cookies with respect to overall liking, desire to eat, and the amount consumed. In conclusion, this study shows that sensory evaluation using multiple bites/sips of ad libitum food consumption, along with a measurement of beneficial compounds, is efficient in determining appropriate vehicles for clinical studies of wild blueberry-containing foods.

Changes in Polyphenolics during Storage of Products Prepared with Freeze-Dried Wild Blueberry Powder

Wild blueberry (WBB) powder can be added to the formulation of foods to encourage consumption of health-promoting polyphenolics, but the stability of polyphenolics throughout storage is important. We determined the stability of polyphenolics in five products (ice pop, oatmeal bar, graham cracker cookie, juice, and gummy product) prepared with WBB powder. Samples stored at 21 °C, 4.4 °C, or −20 °C (ice pops only) were analyzed at 0, 2, 4, 6, and 8 weeks for polyphenolic content and percent polymeric color. Total anthocyanins decreased over storage and storage temperatures in all products. However, the ice pop and the refrigerated juice both retained over 90% of their initial total anthocyanin content. The refrigerated oatmeal bar also showed good retention of anthocyanins (86%), but the gummy product retained only 43% and 51% when stored at 4.4 °C or 21 °C, respectively. The lower amount of polyphenolic compounds recovered in the gummies stored at 4.4 °C compared to 21 °C may be attributed to reduced extraction efficiency as a result of gel hardening at refrigerated temperature. Chlorogenic acid and flavonols were generally more stable than anthocyanins throughout storage.

Maternal regulation of SATB2 in osteo-progeniters impairs skeletal development in offspring

Nutritional status during intrauterine and/or early postnatal life has substantial influence on adult offspring health. Along these lines, there is a growing body of evidence illustrating that high fat diet (HFD)-induced maternal obesity can regulate fetal bone development. Thus, we investigated the effects of maternal obesity on both fetal skeletal development and mechanisms linking maternal obesity to osteoblast differentiation in offspring. Embryonic osteogenic calvarial cells (EOCCs) were isolated from fetuses at gestational day 18.5 (E18.5) of HFD-induced obese rat dams. We observed impaired differentiation of EOCCs to mature osteoblasts from HFD obese dams. ChIP-seq-based genome-wide localization of the repressive histone mark H3K27me3 (mediated via the polycomb histone methyltransferase, enhancer of zeste homologue 2 [Ezh2]) showed that this phenotype was associated with increased enrichment of H3K27me3 on the gene of SATB2, a critical transcription factor required for osteoblast differentiation. Knockdown of Ezh2 in EOCCs and ST2 cells increased SATB2 expression; while Ezh2 overexpression in EOCCs and ST2 cells decreased SATB2 expression. These data were consistent with experimental results showing strong association between H3K27me3, Ezh2, and SATB2 in cells from rats and humans. We have further presented that SATB2 mRNA and protein expression were increased in bones, and increased trabecular bone mass from pre-osteoblast specific Ezh2 deletion (Ezh2^flox/flox Osx-Cre⁺ cko) mice compared with those from control Cre⁺ mice. These findings indicate that maternal HFD-induced obesity may be associated with decreasing fetal pre-osteoblastic cell differentiation, under epigenetic control of SATB2 expression via Ezh2-dependent mechanisms.

3-(3-Hydroxyphenyl)-Propionic Acid (PPA) Suppresses Osteoblastic Cell Senescence to Promote Bone Accretion in Mice

Phenolic acids (PAs) are metabolites derived from polyphenolic compounds found in fruits and vegetables resulting from the actions of gut bacteria. Previously, we reported that the levels of seven individual PAs were found to be at least 10 times higher in the serum of rats fed a blueberry (BB)‐containing diet compared to those fed a control diet. We have characterized the effects of one such BB‐associated serum PA, 3‐(3‐hydroxyphenyl)‐propionic acid (PPA), on senescence signaling and promotion of mesenchymal stem cell differentiation toward osteoblasts, while suppressing adipogenesis in the stem cells. To better understand the mechanistic actions of PPA on bone formation in vivo, we administered four doses of PPA (0.1, 0.5, 1, and 5 mg/kg/day; daily i.p.) to 1‐month‐old female C57BL6/J mice for 30 days. We did not observe significant effects of PPA on cortical bone; however, there were significantly higher bone volume and trabecular thickness and increased osteoblastic cell number, but decreased osteoclastic cell number in PPA‐treated groups compared to controls. These morphological and cellular outcomes of bone were reflected in changes of bone formation markers in serum and bone marrow plasma. PPA treatment reduced senescence signaling as evaluated by senescence‐associated β‐galactosidase activity, PPARγ, p53, and p21 expression in bone. In conclusion, PPA is capable of altering the mesenchymal stem cell differentiation program and bone cell senescence. This raises the possibility that BB‐rich diets promote bone growth through increasing systemic PAs, a question that merits additional investigation. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Hippuric acid and 3-(3-hydroxyphenyl) propionic acid inhibit murine osteoclastogenesis through RANKL-RANK independent pathway

Nutritional factors influence bone development. Previous studies demonstrated that bone mass significantly increased with suppressed bone resorption in early life of rats fed with AIN-93G semi-purified diets supplemented with 10% whole blueberry (BB) powder for 2 weeks. However, the effects of increased phenolic acids in animal serum due to this diet on bone and bone resorption were unclear. This in vitro and in ex vivo study examined the effects of phenolic hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA) on osteoclastic cell differentiation and bone resorption. We cultured murine osteoclast (macrophage) cell line, RAW 264.7 cells, and hematopoietic osteoclast progenitor cells (isolated from 4-week-old C57BL6/J mice) with 50 ng/ml of receptor activator of nuclear factor κ-Β ligand (RANKL). Morphologic studies showed decreased osteoclast number with treatment of 2.5% mouse serum from BB diet-fed animals compared with those treated with serum from standard casein diet-fed mice in both RAW 264.7 cell and primary cell cultures. HA and 3-3-PPA, but not 3-4-PPA, had dose-dependent suppressive effects on osteoclastogenesis and osteoclast resorptive activity in Corning osteo-assay plates. Signaling pathway analysis showed that after pretreatment with HA or 3-3-PPA, RANKL-stimulated increase of osteoclastogenic markers, such as nuclear factor of activated T-cells, cytoplasmic 1 and matrix metallopeptidase 9 gene/protein expression were blunted. Inhibitory effects of HA and 3-3-PPA on osteoclastogenesis utilized RANKL/RANK independent mediators. The study revealed that HA and 3-3-PPA significantly inhibited osteoclastogenesis and bone osteoclastic resorptive activity.

Wnt Signaling Mediated Inhibition of Osteoclastogenesis by Dietary Phenolic Hippuric Acid and 3-(3-hydroxyphenyl) Propionic Acid (3–3-PPA) (P01-037-19)

Objectives

Nutritional factors influence bone development. We have previously reported that Blueberry (BB) and BB-associated phenolic acids had significant effects on increasing bone mass in rats. We also found BB-associated phenolic acids [hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA)] inhibited osteoclastogenesis in vitro and in ex vivo. Here, we investigated the mechanisms by which HA or 3-3-PPA inhibit osteoclast formation and if HA or 3-3-PPA inhibits bone resorption in vivo.

Methods

Murine osteoclast (macrophage) cell line, RAW 264.7 cells, and hematopoietic osteoclast progenitor cells (isolated from 4 weeks old C57BL6/J mice) were cultured. Cells were treated with HA or 3-3-PPA (0.6, 6, 60, 600 µg/dL) for 4 days in the presence of 50 ng/ml of RANKL (Receptor activator of nuclear factor kappa-Β ligand). In animal studies, dietary HA or 3-3-PPA was provided at 1, 5 or 10 mg/kg/d to female mice for 4 weeks, starting at postnatal day 28.

Results

In RAW 264.7 cell and primary cell cultures, TRAPase staining showed that RANKL-stimulated osteoclast number/well dose-dependently decreased with treatments of HA or 3-3-PPA. HA and 3-3-PPA significantly inhibited RANKL-induced β-catenin and GPR109A (G protein coupled receptor 109A) protein expression. Moreover, RANKL-induced β-catenin and GPR109A mRNA expression were also suppressed by HA and 3-3-PPA. Furthermore, after pre-treatment with HA or 3-3-PPA, RANKL-stimulated increases of Wnt/β-catenin down-stream genes such as c-myc, and osteoclastogenic genes such as NFkB and NFATc1 gene expression were blunted. In mice, we found significantly increased bone mass in dietary HA and 3-3-PPA supplemented groups compared to control group (P < 0.05). Increased bone mass in HA and 3-3-PPA treated mice was accompanied by decreased bone resorption (bone resorption markers and osteoclastogenic gene expression), but increased β-catenin expression in total protein isolated from bone.

Conclusions

These results indicate significant inhibition of osteoclastogenesis and bone resorption by HA and 3-3-PPA, and suggest that HA and 3-3-PPA inhibit bone marrow the hematopoietic cell differentiation program through non-canonical Wnt signaling to protect against increased bone resorption.

Funding Sources

USDA-ARS Project.

[Abnormal expression of angiopoietin-2 associated with invasion, metastasis and prognosis of lung cancer]

Objective: To investigate the relationship between abnormal angiopoietin-2 (Ang-2) expression and invasion/metastasis of lung cancer. Methods: Totally 122 cases of postoperative primary lung cancer tissues and their paracancerous tissues from Jan. 2009 to Dec. 2010 were collected from Affiliated Hospital of Nantong University and Ang-2 expression was analyzed by immunohistochemistry. At the cellular level, the protein and mRNA levels of Ang-2 in lung epithelial cell line Beas-2B and four lung cancer cell lines (SPCA-1, NCI-1650, A549 and NCI-H1975) were observed. The most effective Ang-2-shRNA for Ang-2 transcription was screened and transfected into A 549 lung cancer cells. The Ang-2 expression, Ang-2 gene transcription, cell proliferation, invasion/metastasis, and epithelial-mesenchymal transition (EMT) abilities of lung cancer cells were analyzed by Western blotting, fluorescent quantitative reverse transcriptase PCR, Cell Counting Kit-8 assay, and Transwell cell models for exploring the relationship between Ang-2 expression and invasion/metastasis of lung cancer. Results: The higher Ang-2 expression levels in lung cancerous tissues were closely related to tumor diameter (P=0.008), differentiating degree (P=0.033), TNM stage (P=0.025) and 5-year survival rate (P<0.001). According to the Kaplan-Meier survival curves, the 5-year survival rate of patients with higher expression levels of Ang-2 (16.1%) was significantly poorer than that of patients with lower Ang-2 (80.0%, P<0.001). Significant difference of 5-year survival rate was found in patients with different Ang-2 levels at TNM stage Ⅰ(P<0.001), but not at stage Ⅱ, Ⅲ and Ⅳ. Among Beas-2B and four lung cancer cell lines, the protein and mRNA levels of Ang-2 in A549 cells were the highest. After Ang-2-shRNA-1 plasmid successfully transfected into A549 cells, cell proliferation rate was significantly lower than that in the shRNA-negative or blank group at a time-dependent manner. The significant decrease of the invasion, migration and EMT abilities were also found in A549 cells after transfection of Ang-2 shRNA. Conclusion: Abnormal expression of Ang-2 is closely related to invasion, migration and prognosis of lung cancer, and interfering the activation of Ang-2 would be a novel molecular-targeted therapy for lung cancer.

Maternal obesity impairs skeletal development in adult offspring

Intrauterine or early postnatal high-fat diet (HFD) has substantial influences on adult offspring health; however, studies of HFD-induced maternal obesity on regulation of adult offspring bone formation are sparse. Here, we investigated the effects of HFD-induced maternal obesity on both fetal and adult offspring skeletal development. We found that HFD-induced maternal obesity significantly decreased fetal skeletal development, but enhanced fetal osteoblastic cell senescence signaling and significantly increased the expression of inflammatory factors of the senescence-associated secretory phenotype (SASP) in osteo-progenitors. It was found that p300/CBP activation led to H3K27 acetylation to increase the expression of senescence-related genes and PPARγ in embryonic mouse osteogenic calvarial cells from HFD obese dams. These results were recapitulated in human umbilical cord mesenchymal stem cells (UC MSCs) isolated from offspring of pregnant obese and lean mothers following delivery. Regardless of postnatal HFD challenge, adult offspring from HFD obese dams showed significantly suppressed bone formation. Such early involution of bone formation of adult offspring from HFD obese dams may at least in part due to histone acetylation, i.e., epigenetic regulation of genes involved in cell senescence signaling in pre-osteoblasts from prenatal development. These findings indicate fetal pre-osteoblastic cell senescence signaling is epigenetically regulated by maternal obesity to repress bone formation in adult offspring in rodents and suggest that at least some of these effects may also manifest in humans.

NOX4 Deletion in Male Mice Exacerbates the Effect of Ethanol on Trabecular Bone and Osteoblastogenesis

Chronic alcohol consumption increases bone resorption and decreases bone formation. A major component of ethanol (EtOH) pathology in bone is the generation of excess reactive oxygen species (ROS). The ROS-generating NADPH oxidase-4 (NOX4) is proposed to drive much of the EtOH-induced suppression of bone formation. Here, 13-week-old male wild-type (WT) and NOX4^-/- mice were pair fed (PF) a high-fat (35%), Lieber-DeCarli liquid diet with or without EtOH at 30% of their total calories for 12 weeks. Micro-computed tomography analysis demonstrated significant decreases in trabecular bone volume/total volume (BV/TV) percentage and cortical thickness in WT, EtOH-fed mice compared with PF controls. EtOH-fed NOX4^-/- mice also displayed decreased trabecular BV/TV and trabecular number compared with PF (P < 0.05). However, NOX4^-/- mice were protected against EtOH-induced decreases in cortical thickness (P < 0.05) and decreases in collagen1 and osteocalcin mRNA expression in cortical bone (P < 0.05). In WT and NOX4^-/- vertebral bone, EtOH suppressed expression of Wnt signaling components that promote osteoblast maturation. A role for NOX4 in EtOH inhibition of osteoblast differentiation was further demonstrated by protection against EtOH inhibition of osteoblastogenesis in ex vivo bone marrow cultures from NOX4^-/-, but not p47^phox-/- mice lacking active NADPH oxidase-2. However, bone marrow cultures from NOX4^-/- mice formed fewer osteoblastic colonies compared with WT cultures (P < 0.05), suggesting a role for NOX4 in the maintenance of mesenchymal progenitor cell populations. These data suggest that NOX4 deletion is partially protective against EtOH effects on osteoblast differentiation, but may predispose bone to osteogenic impairments.

The Relationship between Emergency Response Time and Out-Of-Hospital Cardiac Arrest Prognosis: A Meta-Analysis

Objective

To assess the relationship between emergency response time and prognosis of patients with out-of-hospital cardiac arrest.

Design

Systematic review.

Methods

Relevant observational studies were identified by a search of PubMed and ISI databases to 30 January 2014. Primary outcome was survival to discharge. The weighted mean differences (WMD) for response time were calculated for those survivals to discharge and death in hospital. We also carried out a dose response meta-analysis for assessing summary odds ratio (OR) of survival by response time.

Results

A total of 13 studies with 804,998 patients included in the meta-analysis. The WMD of response time between survivals to discharge group and death in hospital group was 1.976 (95% confidence interval [CI] = 1.161-2.792; p<0.001). Sensitivity analyses by only included prospective cohorts showed the WMD of response time between two groups was 1.115 (95% CI=0.508-1.723; p<0.001). Dose-response relationship between response time and survival to discharge risk was observed statistically significant (χ2=39.86, p<0.001). In linear model, the summary OR was 0.914 (95% CI=0.889-0.940) for every 1 minutes delay in response time. In spline model, the survival OR decreased along with the response time, especially when response time less than 7 minutes.

Conclusions

Emergency response time is an important risk factor for prognosis after OHCA in adults. The EMS team must arrive as soon as possible to the site of the event. (Hong Kong j.emerg.med. 2015;22:345-351)

Partial Protection by Dietary Antioxidants Against Ethanol-Induced Osteopenia and Changes in Bone Morphology in Female Mice

BACKGROUND

Chronic alcohol consumption leads to increased fracture risk and an elevated risk of osteoporosis by decreasing bone accrual through increasing osteoclast activity and decreasing osteoblast activity. We have shown that this mechanism involves the generation of reactive oxygen species (ROS) produced by NADPH oxidases. It was hypothesized that different dietary antioxidants, N-acetyl cysteine (NAC; 1.2 mg/kg/d), and α-tocopherol (Vit.E; 60 mg/kg/d) would be able to attenuate the NADPH oxidase-mediated ROS effects on bone due to chronic alcohol intake.

METHODS

To study the effects of these antioxidants, female mice received a Lieber-DeCarli liquid diet containing ethanol (EtOH) with or without additional antioxidant for 8 weeks.

RESULTS

Tibias displayed decreased cortical bone mineral density in both the EtOH and EtOH + antioxidant groups compared to pair-fed (PF) and PF + antioxidant groups (p < 0.05). However, there was significant protection from trabecular bone loss in mice fed either antioxidant (p < 0.05). Microcomputed tomography analysis demonstrated a significant decrease in bone volume (bone volume/tissue volume) and trabecular number (p < 0.05), along with a significant increase in trabecular separation in the EtOH compared to PF (p < 0.05). In contrast, the EtOH + NAC and EtOH + Vit.E did not statistically differ from their respective PF controls. Ex vivo histologic sections of tibias were stained for nitrotyrosine, an indicator of intracellular damage by ROS, and tibias from mice fed EtOH exhibited significantly more staining than PF controls. EtOH treatment significantly increased the number of marrow adipocytes per mm as well as mRNA expression of aP2, an adipocyte marker in bone. Only NAC was able to reduce the number of marrow adipocytes to PF levels. EtOH-fed mice exhibited reduced bone length (p < 0.05) and had a reduced number of proliferating chondrocytes within the growth plate. NAC and Vit.E prevented this (p < 0.05).

CONCLUSIONS

These data show that alcohol's pathological effects on bone extend beyond decreasing bone mass and suggest a partial protective effect of the dietary antioxidants NAC and Vit.E at these doses with regard to alcohol effects on bone turnover and bone morphology.

Maternal Obesity Programs Senescence Signaling and Glucose Metabolism in Osteo-Progenitors From Rat and Human

Nutritional status during intrauterine and early postnatal life impacts the risk of chronic diseases, presumably via epigenetic mechanisms. However, evidence on the impact of gestational events on regulation of embryonic bone cell fate is sparse. We investigated the effects of maternal obesity on fetal osteoblast development in both rodents and humans. Female rats were fed control or an obesogenic high-fat diet (HFD) for 12 weeks and mated with male rats fed control diets, and respective maternal diets were continued during pregnancy. Embryonic rat osteogenic calvarial cells (EOCCs) were taken from gestational day 18.5 fetuses from control and HFD dams. EOCCs from HFD obese dams showed increases in p53/p21-mediated cell senescence signaling but decreased glucose metabolism. Decreased aerobic glycolysis in HFD-EOCCs was associated with decreased osteoblastic cell differentiation and proliferation. Umbilical cord human mesenchymal stem cells (MSCs) from 24 pregnant women (12 obese and 12 lean) along with placentas were collected upon delivery. The umbilical cord MSCs of obese mothers displayed less potential toward osteoblastogenesis and more towards adipogenesis. Human MSCs and placenta from obese mothers also exhibited increased cell senescence signaling, whereas MSCs showed decreased glucose metabolism and insulin resistance. Finally, we showed that overexpression of p53 linked increased cell senescence signaling and decreased glucose metabolism in fetal osteo-progenitors from obese rats and humans. These findings suggest programming of fetal preosteoblastic cell senescence signaling and glucose metabolism by maternal obesity.

Dietary factors during early life program bone formation in female rats

Nutritional status during intrauterine and early postnatal life impacts the risk of chronic diseases; however, evidence for an association between early-life dietary factors and bone health in adults is limited. Soy protein isolate (SPI) may be one such dietary factor that promotes bone accretion during early life with persistent effects into adulthood. In the present study, we fed postnatal day (PND) 24 weanling female rats an SPI diet for 30 d [short-term SPI (ST-SPI)], and on PND 55, we switched SPI diet to control Cas diet until age 6 mo. Rats then underwent either ovariectomy (OVX) or sham surgery and thereafter either continued to be fed an SPI diet or control diet for 1 or 3 wk. We showed significantly increased bone mass in 30-d SPI-fed young rats compared with controls. OVX-induced bone loss was associated with increased osteoblastic cell senescence. On the one hand, both long-term SPI (continuous SPI diet throughout life) and ST-SPI diet only in early life protected against 1 wk post-OVX-associated bone loss. On the other hand, long-term SPI diet diminished the loss of total, trabecular, and cortical bone mineral density, whereas ST-SPI diet only reduced cortical bone mineral density loss 3 wk post-OVX. Persistent and protective effects of SPI diets on OVX-induced bone loss were associated with down-regulation of the caveolin-1/p53-mediated senescence pathway in bone. We recapitulated these results in cell cultures. Reprogramming of cellular senescence signaling by SPI-associated isoflavones in osteoblastic cells may explain the persistent effects of SPI on bone. These results suggest that OVX-induced bone loss, in part, is a result of increased osteoblastic cell senescence, and that ST-SPI diet early in life has modest but persistent programming effects on bone formation to prevent OVX-induced bone loss in adult female rats.-Chen, J.-R., Lazarenko, O. P., Blackburn, M. L., Shankar, K. Dietary factors during early life program bone formation in female rats.

Reactive Oxygen Species Differentially Regulate Bone Turnover in an Age-Specific Manner in Catalase Transgenic Female Mice

Chronic ethyl alcohol (EtOH) consumption results in reactive oxygen species (ROS) generation in bone and osteopenia due to increased bone resorption and reduced bone formation. In this study, transgenic C57Bl/6J mice overexpressing human catalase (TgCAT) were used to test whether limiting excess hydrogen peroxide would protect against EtOH-mediated bone loss. Micro-computed tomography analysis of the skeletons of 6-week-old female chow-fed TgCAT mice revealed a high bone mass phenotype with increased cortical bone area and thickness as well as significantly increased trabecular bone volume (P < 0.05). Six-week-old wild-type (WT) and TgCAT female mice were chow fed or pair fed (PF) liquid diets with or without EtOH, approximately 30% of calories, for 8 weeks. Pair feeding of WT had no demonstrable effect on the skeleton; however, EtOH feeding of WT mice significantly reduced cortical and trabecular bone parameters along with bone strength compared with PF controls (P < 0.05). In contrast, EtOH feeding of TgCAT mice had no effect on trabecular bone compared with PF controls. At 14 weeks of age, there was significantly less trabecular bone and cortical cross-sectional area in TgCAT mice than WT mice (P < 0.05), suggesting impaired normal bone accrual with age. TgCAT mice expressed less collagen1α and higher sclerostin mRNA (P < 0.05), suggesting decreased bone formation in TgCAT mice. In conclusion, catalase overexpression resulted in greater bone mass than in WT mice at 6 weeks and lower bone mass at 14 weeks. EtOH feeding induced significant reductions in bone architecture and strength in WT mice, but TgCAT mice were partially protected. These data implicate ROS signaling in the regulation of bone turnover in an age-dependent manner, and indicate that excess hydrogen peroxide generation contributes to alcohol-induced osteopenia.

p47phox-Nox2-dependent ROS Signaling Inhibits Early Bone Development in Mice but Protects against Skeletal Aging

Bone remodeling is age-dependently regulated and changes dramatically during the course of development. Progressive accumulation of reactive oxygen species (ROS) has been suspected to be the leading cause of many inflammatory and degenerative diseases, as well as an important factor underlying many effects of aging. In contrast, how reduced ROS signaling regulates inflammation and remodeling in bone remains unknown. Here, we utilized a p47(phox) knock-out mouse model, in which an essential cytosolic co-activator of Nox2 is lost, to characterize bone metabolism at 6 weeks and 2 years of age. Compared with their age-matched wild type controls, loss of Nox2 function in p47(phox-/-) mice resulted in age-related switch of bone mass and strength. Differences in bone mass were associated with increased bone formation in 6-week-old p47(phox-/-) mice but decreased in 2-year-old p47(phox-/-) mice. Despite decreases in ROS generation in bone marrow cells and p47(phox)-Nox2 signaling in osteoblastic cells, 2-year-old p47(phox-/-) mice showed increased senescence-associated secretory phenotype in bone compared with their wild type controls. These in vivo findings were mechanistically recapitulated in ex vivo cell culture of primary fetal calvarial cells from p47(phox-/-) mice. These cells showed accelerated cell senescence pathway accompanied by increased inflammation. These data indicate that the observed age-related switch of bone mass in p47(phox)-deficient mice occurs through an increased inflammatory milieu in bone and that p47(phox)-Nox2-dependent physiological ROS signaling suppresses inflammation in aging.

Soy protein isolate inhibits high-fat diet-induced senescence pathways in osteoblasts to maintain bone acquisition in male rats

Chronic consumption by experimental animals of a typical Western diet high in saturated fats and cholesterol during postnatal life has been demonstrated to impair skeletal development. However, the underlying mechanism by which high-fat, energy-dense diets affect bone-forming cell phenotypes is poorly understood. Here, we show that male weanling rats fed a diet containing 45% fat and 0.5% cholesterol made with casein (HF-Cas) for 6 weeks displayed lower bone mineral density and strength compared with those of AIN-93G-fed dietary controls. Substitution of casein with soy protein isolate (SPI) in the high-fat diet (HF-SPI) prevented these effects. The bone-sparing effects of SPI were associated with prevention of HF-Cas-induced osteoblast senescence pathways through suppression of the p53/p21 signaling pathways. HF-Cas-fed rats had increased caveolin-1 and down-regulated Sirt1, leading to activations of peroxisome proliferator-activated receptor γ (PPARγ) and p53/p21, whereas rats fed HF-SPI suppressed caveolin-1 and activated Sirt1 to deacetylate PPARγ and p53 in bone. Treatment of osteoblastic cells with nonesterified free fatty acid (NEFA) increased cell senescence signaling pathways. Isoflavones significantly blocked activations of senescence-associated β-galactosidase and PPARγ/p53/p21 by NEFA. Finally, replicative senescent osteoblastic cells and bone marrow mesenchymal ST2 cells exhibited behavior similar to that of cells treated with NEFA and in vivo bone cells in rats fed the HF-Cas diet. These results suggest that (1) high concentrations of NEFA occurring with HF intake are mediators of osteoblast cell senescence leading to impairment of bone development and acquisition and (2) the molecular mechanisms underlying the SPI-protective effects involve isoflavone-induced inhibition of osteoblastic cell senescence to prevent HF-induced bone impairments.

A universal fluorescence sensing strategy based on biocompatible graphene quantum dots and graphene oxide for the detection of DNA

A novel and efficient fluorescence sensing platform based on biocompatible graphene quantum dots and graphene oxide was established. It showed high selectivity and sensitivity for DNA detection.

Diet-derived phenolic acids regulate osteoblast and adipocyte lineage commitment and differentiation in young mice

A blueberry (BB)-supplemented diet has been previously shown to significantly stimulate bone formation in rapidly growing male and female rodents. Phenolic acids (PAs) are metabolites derived from polyphenols found in fruits and vegetables as a result of the actions of gut bacteria, and they were found in the serum of rats fed BB-containing diet. We conducted in vitro studies with PAs and demonstrated stimulation of osteoblast differentiation and proliferation. On the other hand, adipogenesis was inhibited. To more fully understand the mechanistic actions of PAs on bone formation, we administered hippuric acid, one of the major metabolites found in animal circulation after BB consumption, to prepubertal female mice for 2 weeks. We found that hippuric acid was able to stimulate bone-forming gene expression but suppress PPARγ expression, leading to increased bone mass dose-dependently. Cellular signaling studies further suggested that the skeletal effects of PAs appeared to be mediated through activation of G-protein-coupled receptor 109A and downstream p38 MAP kinase and osterix. In conclusion, PAs are capable of altering the mesenchymal stem cell differentiation program and merit investigation as potential dietary therapeutic alternatives to drugs for degenerative bone disorders. © 2014 American Society for Bone and Mineral Research.

Loss of functional NADPH oxidase 2 protects against alcohol-induced bone resorption in female p47phox-/- mice

BACKGROUND

In bone, NADPH oxidase (NOX)-derived reactive oxygen species (ROS) superoxide and/or hydrogen peroxide are an important stimulus for osteoclast differentiation and activity. Previously, we have demonstrated that chronic ethanol (EtOH) consumption generates excess NOX-dependent ROS in osteoblasts, which functions to stimulate nuclear factor kappa-β receptor ligand (RANKL)-RANK signaling, thus increasing osteoclastogenesis and activity. This activity can be blocked by co-administration of EtOH with the pan-NOX inhibitor diphenylene idonium (DPI).

METHODS

To test whether EtOH-induced bone loss is dependent on a functional NOX2 enzyme, 6-week-old female C57BL/6J-Ncf1/p47phox(-/-) (p47phox KO) and wild-type (WT) mice were pair-fed EtOH diets for 40 days. Bone loss was assessed by 3-point bending, micro-computed tomography and static histomorphometric analysis. Additionally, ST2 cultured cells were co-treated with EtOH and NOX inhibitors, DPI, gliotoxin, and plumbagin, after which changes in ROS production, and in RANKL and NOX mRNA expression were analyzed.

RESULTS

In WT mice, EtOH treatment significantly reduced bone density and mechanical strength, and increased total osteoclast number and activity. In EtOH-treated p47phox KO mice, bone density and mechanical strength were completely preserved. EtOH p47phox KO mice had no changes in osteoclast numbers or activity, and no elevations in serum CTX or RANKL gene expression (p < 0.05). In both WT and p47phox KO mice, EtOH feeding reduced biochemical markers of bone formation (p < 0.05). In vitro EtOH exposure of ST2 cells increased ROS, which was blocked by pretreating with DPI or the NOX2 inhibitor gliotoxin. EtOH-induced RANKL and NOX2 gene expression were inhibited by the NOX4-specific inhibitor plumbagin.

CONCLUSIONS

These data suggest that NOX2-derived ROS is necessary for EtOH-induced bone resorption. In osteoblasts, NOX2 and NOX4 appear to work in tandem to increase RANKL expression, whereas EtOH-mediated inhibition of bone formation occurs via a NOX2-independent mechanism.

Differential contributions of basal ganglia and thalamus to song initiation, tempo, and structure

Basal ganglia-thalamocortical circuits are multistage loops critical to motor behavior, but the contributions of individual components to overall circuit function remain unclear. We addressed these issues in a songbird basal ganglia-thalamocortical circuit (the anterior forebrain pathway, AFP) specialized for singing and critical for vocal plasticity. The major known afferent to the AFP is the premotor cortical nucleus, HVC. Surprisingly, previous studies found that lesions of HVC alter song but do not eliminate the ability of the AFP to drive song production. We therefore used this AFP-driven song to investigate the role of basal ganglia and thalamus in vocal structure, tempo, and initiation. We found that lesions of the striatopallidal component (Area X) slowed song and simplified its acoustic structure. Elimination of the thalamic component (DLM) further simplified the acoustic structure of song and regularized its rhythm but also dramatically reduced song production. The acoustic structure changes imply that sequential stages of the AFP each add complexity to song, but the effects of DLM lesions on song initiation suggest that thalamus is a locus of additional inputs important to initiation. Together, our results highlight the cumulative contribution of stages of a basal ganglia-thalamocortical circuit to motor output along with distinct involvement of thalamus in song initiation or "gating."

Soy protein isolates prevent loss of bone quantity associated with obesity in rats through regulation of insulin signaling in osteoblasts

In both rodents and humans, excessive consumption of a typical Western diet high in saturated fats and cholesterol is known to result in disruption of energy metabolism and development of obesity and insulin resistance. However, how these high-fat, energy-dense diets affect bone development, morphology, and modeling is poorly understood. Here we show that male weanling rats fed a high-fat (HF) diet containing 45% fat and 0.5% cholesterol made with casein (HF-Cas) for 6 wk displayed a significant increase in bone marrow adiposity and insulin resistance. Substitution of casein with soy protein isolate (SPI) in the HF diet (HF-SPI) prevented these effects. Maintenance of bone quantity in the SPI-fed rats was associated with increased undercarboxylated osteocalcin secretion and altered JNK/IRS1/Akt insulin signaling in osteoblasts. The HF-Cas group had significantly greater serum nonesterified free fatty acid (NEFA) concentrations than controls, whereas the HF-SPI prevented this increase. In vitro treatment of osteoblasts or mesenchymal stromal ST2 cells with NEFAs significantly decreased insulin signaling. An isoflavone mixture similar to that found in serum of HF-SPI rats significantly increased in vitro osteoblast proliferation and blocked significantly reduced NEFA-induced insulin resistance. Finally, insulin/IGF1 was able to increase both osteoblast activity and differentiation in a set of in vitro studies. These results suggest that high-fat feeding may disrupt bone development and modeling; high concentrations of NEFAs and insulin resistance occurring with high fat intake are mediators of reduced osteoblast activity and differentiation; diets high in soy protein may help prevent high dietary fat-induced bone impairments; and the molecular mechanisms underlying the SPI-protective effects involve isoflavone-induced normalization of insulin signaling in bone.

Blueberry consumption prevents loss of collagen in bone matrix and inhibits senescence pathways in osteoblastic cells

Ovariectomy (OVX)-induced bone loss has been linked to increased bone turnover and higher bone matrix collagen degradation as the result of osteoclast activation. However, the role of degraded collagen matrix in the fate of resident bone-forming cells is unclear. In this report, we show that OVX-induced bone loss is associated with profound decreases in collagen 1 and Sirt1. This was accompanied by increases in expression and activity of the senescence marker collagenase and expression of p16/p21 in bone. Feeding a diet supplemented with blueberries (BB) to pre-pubertal rats throughout development or only prior to puberty [postnatal day 21 (PND21) to PND34] prevents OVX-induced effects on expression of these molecules at PND68. In order to provide more evidence and gain a better understanding on the association between bone collagen matrix and resident bone cell fate, in vitro studies on the cellular senescence pathway using primary calvarial cells and three cell lines (ST2 cells, OB6, and MLO-Y4) were conducted. We found that senescence was inhibited by collagen in a dose-response manner. Treatment of cells with serum from OVX rats accelerated osteoblastic cell senescence pathways, but serum from BB-fed OVX rats had no effect. In the presence of low collagen or treatment with OVX rat serum, ST2 cells exhibited higher potential to differentiate into adipocytes. Finally, we demonstrated that bone cell senescence is associated with decreased Sirt1 expression and activated p53, p16, and p21. These results suggest that (1) a significant prevention of OVX-induced bone cell senescence from adult rats can occur after only 14 days consumption of a BB-containing diet immediately prior to puberty, and (2) the molecular mechanisms underlying this effect involves, at least in part, prevention of collagen degradation.

Vitamin D supplementation protects against bone loss associated with chronic alcohol administration in female mice

Chronic alcohol abuse results in decreased bone mineral density (BMD), which can lead to increased fracture risk. In contrast, low levels of alcohol have been associated with increased BMD in epidemiological studies. Alcohol's toxic skeletal effects have been suggested to involve impaired vitamin D/calcium homeostasis. Therefore, dietary vitamin D supplementation may be beneficial in reducing bone loss associated with chronic alcohol consumption. Six-week-old female C57BL/6J mice were pair-fed ethanol (EtOH)-containing liquid diets (10 or 36% total calories) for 78 days. EtOH exposure at 10% calories had no effects on any measured bone or serum parameter. EtOH consumption at 36% of calories reduced BMD and bone strength (P<0.05), decreased osteoblastogenesis, increased osteoclastogenesis, suppressed 1,25-hydroxyvitamin D3 [1,25(OH)2D3] serum concentrations (P<0.05), and increased apoptosis in bone cells compared with pair-fed controls. In a second study, female mice were pair-fed 30% EtOH diets with or without dietary supplementation with vitamin D3 (cholecalciferol; VitD) for 40 days. VitD supplementation in the EtOH diet protected against cortical bone loss, normalized alcohol-induced hypocalcaemia, and suppressed EtOH-induced expression of receptor of nuclear factor-κB ligand mRNA in bone. In vitro, pretreatment of 1,25(OH)2D3 in osteoblastic cells inhibited EtOH-induced apoptosis. In EtOH/VitD mice circulating 1,25(OH)2D3 was lower compared with mice receiving EtOH alone (P<0.05), suggesting increased sensitivity to feedback control of VitD metabolism in the kidney. These findings suggest dietary VitD supplementation may prevent skeletal toxicity in chronic drinkers by normalizing calcium homeostasis, preventing apoptosis, and suppressing EtOH-induced increases in bone resorption.

Differential effects of short term feeding of a soy protein isolate diet and estrogen treatment on bone in the pre-pubertal rat

Background

Previous reports suggest that beneficial effects of soy on bone quality are due to the estrogenic actions of isoflavone phytochemicals associated with the protein. However, mechanistic studies comparing the effects of soy diet and estrogens on bone, particularly in rapidly growing animals are lacking.

Methodology and Principal Findings

We studied the effects of short term feeding of soy protein isolate (SPI) on bone in comparison to the effects of 17β-estradiol (E2) in pre-pubertal rats. Female rats were weaned to one of 4 treatments: 1) a control casein-based diet (CAS); 2) CAS with subcutaneous E2 (10 µg/kg/d) (CAS+E2); 3) a SPI-containing diet (SPI); or 4) SPI with subcutaneous E2 (SPI) or SPI with 10 µg/kg/d E2 (SPI+E2) for 14 days beginning on postnatal day 20. SPI increased while E2 decreased bone turnover compared to CAS. In contrast, both treatments decreased serum sclerostin levels. Microarray analysis of RNA isolated from bone revealed 652 genes regulated by SPI, 491 genes regulated by E2, and 266 genes regulated by both SPI diet and E2 compared to CAS. The expression of caveolin-1, a protein localized in the cell membrane, was down-regulated (p<0.05) in rats fed SPI, but not by E2 compared to rats fed casein. Down-regulation of caveolin-1 by SPI was associated with increased BMP2, Smad and Runx2 expression in bone and osteoblasts (p<0.05).

Conclusions/Significance

These results suggest SPI and E2 have different effects on bone turnover prior to puberty. Approximately half of the genes are regulated in the same direction by E2 or SPI, but in combination, SPI blocks the estrogen effects and returns the profile towards control levels. In addition, there are E2 specific and SPI-specific gene changes related to regulation of bone formation.

Inhibition of fetal bone development through epigenetic down-regulation of HoxA10 in obese rats fed high-fat diet

Epidemiological studies show that maternal obesity during intrauterine and early postnatal life increases the risk of low bone mass and fracture later in life. Here, we show that bone development is inhibited in gestational embryonic day 18.5 (E18.5) embryos from rat dams made obese by feeding a high-fat diet (HFD). Moreover, fetal rat osteogenic calvarial cells (FOCCs) from these obese dams have significantly less potential to develop into mature osteoblasts compared to cells from AIN-93G diet-fed controls. Profiling of transcriptional genes for osteogenesis revealed a profound decrease in the homeodomain-containing factor A10 (HoxA10) in FOCCs from fetuses of HFD-induced obese dams. Significant methylation of the HoxA10 promoter was found in those FOCCs, as well as in mouse ST2 cells treated with a mixture of free fatty acids similar to that found in serum from HFD-induced obese rats. This was accompanied by lower expression of osteogenic markers, but higher levels of PPARγ. Control FOCCs depleted of the HoxA10 gene (shRNA) ex vivo behave similarly to cells from fetuses of obese dams; conversely, overexpression of HoxA10 gene in FOCCs from HFD rats exhibit the same phenotype as controls. Treatment of FOCCs from control rats or of ST2 cells with an artificial mixture of free fatty acids significantly down-regulated HoxA10 protein expression, and cells exhibited adipocyte-like properties. These results suggest that maternal obesity impairs fetal skeletal development through down-regulation of the HoxA10 gene, which may lead to an increase in the prevalence of low bone mass in the offspring later in life.

Maternal obesity promotes a proinflammatory signature in rat uterus and blastocyst

Maternal obesity at conception increases the risk of offspring obesity, thus propagating an intergenerational vicious cycle. Male offspring born to obese dams are hyperresponsive to high fat-diets, gaining greater body weight, fat mass, and additional metabolic sequelae compared to lean controls. In this report, we identify the impact of maternal obesity before conception, on the embryo, and intrauterine milieu during the periimplantation period. We conducted global transcriptomic profiling in the uterus and periimplantation blastocyst, gene/protein expression analyses of inflammatory pathways in conjunction with endocrine and metabolic characterization in the dams at implantation. Uterine gene expression profiles of lean and obese dams revealed distinct signatures for genes regulating inflammation and lipid metabolism. Both pathway and gene-set enrichment analysis revealed uterine nuclear factor-κB and c-Jun N-terminal kinase signaling to be up-regulated in the uterus of obese dams, which was confirmed via immunoblotting. Obese uteri also evidenced an inflammatory secretome with higher chemokine mRNA abundance (CCL2, CCL5, CCL7, and CxCL10) and related regulators (TLR2, CD14, and Ccr1). Increased inflammation in the uterus was associated with ectopic lipid accumulation and expression of lipid metabolic genes. Gene expression in sex-identified male periimplantation blastocyst at day postcoitum 4.5 was clearly influenced by maternal obesity (359 transcripts, ±1.4-fold), including changes in developmental and epigenetic regulators. Akin to the uterus, nuclear factor-κB-regulated proinflammatory genes (CCL4 and CCL5) increased and expression of antioxidant (GPx3) and mitochondrial (TFAM and NRF1) genes decreased in the obese embryos. Our results suggest that ectopic lipid and inflammation may link maternal obesity to increased predisposition of offspring to obesity later in life.

Lowbush blueberries inhibit scavenger receptors CD36 and SR-A expression and attenuate foam cell formation in ApoE-deficient mice

Blueberries have recently been reported to reduce atherosclerotic lesion progression in apoE deficient (apoE(-/-)) mice. However, the underlying mechanisms are not fully understood. The objective of this study was to determine whether lowbush blueberries altered scavenger receptor expression and foam cell formation in apoE(-/-) mice. ApoE(-/-) mice were fed AIN-93 diet (CD) or CD formulated to contain 1% freeze-dried lowbush blueberries (BB) for 20 weeks. Gene expression and protein levels of scavenger receptor CD36 and SR-A in aorta and thioglycollate-elicited peritoneal macrophages (PM) were lower in mice fed BB (P < 0.05). In the second experiment, apoE(-/-) mice were fed CD or BB for 5 weeks. PM were collected and cultured. Gene expression and protein levels of CD36 and SR-A were found to be lower in PM of BB fed mice (P < 0.05). In PM from BB fed mice, fewer oxLDL-induced foam cells were formed compared to those from mice fed CD. Gene expression and protein levels of PPARγ were lower in the PM of BB fed mice (P < 0.05). Detectable isomers of hydroxyoctadecadienoic acids (HODEs) and hydroxyeicosatetraenoic acid (HETEs) were also lower in the PM of BB fed mice (P < 0.05 or P < 0.01). In conclusion, BB inhibited expression of the two major scavenger receptors CD36 and SR-A in PM of apoE(-/-) mice, at least in part through down-regulating PPARγ and reducing its endogenous ligands HODEs and HETEs. We proposed that BB mediated reduction of scavenger receptor expression and attenuation of oxLDL-induced foam cell formation in PM of apoE(-/-) mice are important mechanisms of the athero-protective effects of BB.

Phenolic acids are in vivo atheroprotective compounds appearing in the serum of rats after blueberry consumption

Blueberries (BB) have recently been shown to have cardioprotective effects and to prevent atherosclerosis in rodent models. However, the bioactive compounds in BB responsible for these effects have not yet been characterized. Seven phenolic acids (7PA) were identified as metabolites in the serum of rats fed diets supplemented with 10% freeze-dried BB. In this study, 7PA were evaluated for their potential atheroprotective effects in murine macrophage cell line RAW 264.7. 7PA were found to inhibit LPS-induced mRNA expression and protein levels of pro-inflammatory cytokine TNF-α and IL-6 by reducing MAPK JNK, p38, and Erk1/2 phosphorylation. After treatment with 7PA for 2 weeks, mRNA expression and protein levels of scavenger receptor CD36 were decreased (P<0.05), whereas type A scavenger receptor (SR-A) remained unchanged. Moreover, foam cell formation induced by oxLDL and oxLDL binding to macrophages was also inhibited by 7PA. In addition, 7PA increased (P<0.05) expression and protein levels of ATP-binding cassette transporter A1 (ABCA1), which facilitates cholesterol efflux and reduces cholesterol accumulation in macrophages. In summary, the present study demonstrates that certain phenolic acids are potential in vivo atheroprotective compounds following BB consumption in the rodent model. Because BB contain many phytochemicals, other as yet unidentified bioactive compounds may also be important in preventing atherosclerosis in this model and, possibly, in humans.

Feeding blueberry diets in early life prevent senescence of osteoblasts and bone loss in ovariectomized adult female rats

BACKGROUND

Appropriate nutrition during early development is essential for maximal bone mass accretion; however, linkage between early nutrition, childhood bone mass, peak bone mass in adulthood, and prevention of bone loss later in life has not been studied.

METHODOLOGY AND PRINCIPAL FINDINGS

In this report, we show that feeding a high quality diet supplemented with blueberries (BB) to pre-pubertal rats throughout development or only between postnatal day 20 (PND20) and PND34 prevented ovariectomy (OVX)-induced bone loss in adult life. This protective effect of BB is due to suppression of osteoblastic cell senescence associated with acute loss of myosin expression after OVX. Early exposure of pre-osteoblasts to serum from BB-fed rats was found to consistently increase myosin expression. This led to maintenance osteoblastic cell development and differentiation and delay of cellular entrance into senescence through regulation of the Runx2 gene. High bone turnover after OVX results in insufficient collagenous matrix support for new osteoblasts and their precursors to express myosin and other cytoskeletal elements required for osteoblast activity and differentiation.

CONCLUSIONS/SIGNIFICANCE

These results indicate: 1) a significant prevention of OVX-induced bone loss from adult rats can occur with only 14 days consumption of a BB-containing diet immediately prior to puberty; and 2) the molecular mechanisms underlying these effects involves increased myosin production which stimulates osteoblast differentiation and reduces mesenchymal stromal cell senescence.