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Results for “Differentiability”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Pulsed electromagnetic field inhibits RANKL-dependent osteoclastic differentiation in RAW264.7 cells through the Ca{sup 2+}-calcineurin-NFATc1 signaling pathway

Pulsed electromagnetic field (PEMF) has been reported to improve bone healing in osteoporosis patients. However, the precise mechanism has remained largely unknown. This study aimed to investigate the effects of PEMF on nuclear factor κB ligand (RANKL)-dependent osteoclastic differentiation and the Ca{sup 2+}-calcineurin-NFATc1 signaling pathway in RAW264.7 cells in vitro. Treating RAW264.7 cells with RANKL for 4 days induced osteoclastic differentiation in vitro, and the formation of multinucleated osteoclasts, bone resorption-pit formation, tartrate-resistant acid phosphatase (TRAP) activity and the protein levels of cathepsin K, TRAP, Nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) and matrix metalloproteinase 9 (MMP-9) were significantly decreased. The mRNA levels of specific genes related to osteoclastogenesis (TRAP, NFATc1, CTSK and MMP-9) were also reduced. Moreover, the oscillations of intracellular Ca{sup 2+} in RANKL-dependent RAW264.7 cells were suppressed by PEMF, as well as by inhibitors of membrane and store-operated Ca{sup 2+} channels. Meanwhile, calcineurin activity was increased, although its protein level was not changed. PEMF increased phospho-NFATc1 in the cytosol while suppressing the nuclear translocation of NFATc1, thus inhibiting osteoclastic differentiation by suppressing the Ca{sup 2+}-calcineurin-NFATc1 signaling pathway. Although many questions remain unresolved, to our knowledge, this is the first report demonstrating that PEMF is beneficial against RANKL-dependent osteoclastic differentiation in RAW264.7 cells in vitro via inhibiting the Ca{sup 2+}-calcineurin-NFATc1 signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

(-)-Epigallocatechin-3-gallate stimulates myogenic differentiation through TAZ activation

Muscle loss is a typical process of aging. Green tea consumption is known to slow down the progress of aging. Their underlying mechanisms, however, remain largely unknown. In this study, we investigated the effect of (-)-epigallocatechin-3-gallate (EGCG), a polyphenolic compound of green tea, on myogenic differentiation and found that EGCG significantly increases myogenic differentiation. After EGCG treatment, the expression of myogenic marker genes, such as myosin heavy chain, are increased through activation of TAZ, a transcriptional coactivator with a PDZ-binding motif. TAZ-knockdown does not stimulate EGCG-induced myogenic differentiation. EGCG facilitates the interaction between TAZ and MyoD, which stimulates MyoD-mediated gene transcription. EGCG induces nuclear localization of TAZ through the dephosphorylation of TAZ at its Ser89 residue, which relieves 14-3-3 binding in the cytosol. Interestingly, inactivation of Lats kinase is observed after EGCG treatment, which is responsible for the production of dephosphorylated TAZ. Together, these results suggest that EGCG induces myogenic differentiation through TAZ, suggesting that TAZ plays an important role in EGCG induced muscle regeneration. - Highlights: • EGCG stimulates myogenesis in C2C12 and muscle stem cells. • EGCG stimulates MyoD-mediated gene transcription through TAZ activation. • EGCG induces nuclear localization of TAZ through Lats kinase inhibition.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Closed-channel culture system for efficient and reproducible differentiation of human pluripotent stem cells into islet cells

Human pluripotent stem cells (hPSCs) are thought to be a promising cell-source solution for regenerative medicine due to their indefinite proliferative potential and ability to differentiate to functional somatic cells. However, issues remain with regard to achieving reproducible differentiation of cells with the required functionality for realizing human transplantation therapies and with regard to reducing the potential for bacterial or fungal contamination. To meet these needs, we have developed a closed-channel culture device and corresponding control system. Uniformly-sized spheroidal hPSCs aggregates were formed inside wells within a closed-channel and maintained continuously throughout the culture process. Functional islet-like endocrine cell aggregates were reproducibly induced following a 30-day differentiation protocol. Our system shows an easily scalable, novel method for inducing PSC differentiation with both purity and functionality. - Highlights: • A simple, closed-channel-based, semi-automatic culture system is proposed. • Uniform cell aggregate formation and culture is realized in microwell structure. • Functional islet cells are successfully induced following 30-plus-day protocol. • System requires no daily medium replacement and reduces contamination risk.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Piperine induces osteoblast differentiation through AMPK-dependent Runx2 expression

Highlights: • Piperine increases the expression of osteogenic marker genes. • Piperine enhances the alkaline phosphatase activity. • Piperine enhances the mineralization during the osteoblast differentiation. • Piperine induces AMPK phosphorylation. Piperine is an alkaloid responsible for the pungency of black pepper and long pepper. It is reported to have various biological actions such as anti-oxidative and anti-inflammatory, and aids cancer prevention. Antioxidants have been shown to promote osteoblast differentiation. However, osteoblast differentiation by piperine has not yet been elucidated. Piperine-induced expression of the osteogenic genes such as distal-less homeobox 5 (Dlx5), inhibitor of DNA binding-1 (Id1), and runt-related transcription factor 2 (Runx2) was investigated using RT-PCR. In addition, alkaline phosphatase (ALP) activity and mineralization was found to be increased by piperine treatment. Finally, we confirmed that piperine induced phosphorylation of AMPK in MC3T3-E1 cells. Taken together, these results demonstrate that piperine enhance osteoblast differentiation through AMPK phosphorylation in MC3T3-E1 cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Perturbations in carotenoid and porphyrin status result in differential photooxidative stress signaling and antioxidant responses

Highlights: • Two modes of photooxidation by inhibition of carotenoid and porphyrin biosynthesis. • We examine differential photooxidative stress signaling and antioxidant responses. • OF results in greater oxidative damage with respect to membrane integrity than NF. • Free SA and redox state of Asc and GSH have roles in protection from photooxidation. • Differential regulation of ROS-scavenging enzymes between NF and OF plants. We examined differential photooxidative stress signaling and antioxidant responses in rice plants treated with norflurazon (NF) and oxyfluorfen (OF), which are inhibitors of carotenoid and porphyrin biosynthesis, respectively. Plants treated with OF markedly increased levels of cellular leakage and malondialdehyde, compared with NF-treated plants, showing that OF plants suffered greater oxidative damage with respect to membrane integrity. The enhanced production of H{sub 2}O{sub 2} in response to OF, but not NF, indicates the important role of H{sub 2}O{sub 2} in activation of photooxidative stress signaling in OF plants. In response to NF and OF, the increased levels of free salicylic acid as well as maintenance of the redox ratio of ascorbate and glutathione pools to a certain level are considered to be crucial factors in the protection against photooxidation. Plants treated with OF greatly up-regulated catalase (CAT) activity and Cat transcript levels, compared with NF-treated plants. Interestingly, NF plants showed no noticeable increase in oxidative metabolism, although they did show considerable increases in ascorbate peroxidase (APX) and peroxidase activities and transcript levels of APX, as in OF plants. Our results suggest that perturbations in carotenoid and porphyrin status by NF and OF can be sensed by differential photooxidative stress signaling, such as that involving H{sub 2}O{sub 2}, redox state of ascorbate and glutathione, and salicylic acid, which may be responsible for at least part of the induction of ROS-scavenging enzymes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

CBFA2T2 is required for BMP-2-induced osteogenic differentiation of mesenchymal stem cells

Highlights: • CBFA2T2 expression was upregulated by BMP-2 treatment during osteogenesis of MSCs. • Knockdown of CBFA2T2 blunted the BMP-2-induced osteogenic differentiation of MSCs. • Knockdown of CBFA2T2 promoted expression of EHMT1 in BMP-2-treated mBMSCs. • Knockdown of CBFA2T2 increased H3K9me2 levels at promoter of Runx2. Bone morphogenetic protein (BMP) signaling is one of the essential pathways involved in osteogenic differentiation of mesenchymal stem cells (MSCs) and regulation of bone formation. While BMP-2 has been approved for clinic use, the underlying mechanisms remain not fully understood. In this study, we found co-repressor CBFA2T2 (core-binding factor, runt domain, alpha subunit 2, translocated to, 2) expression was significantly upregulated in response to BMP-2 treatment during osteogenic differentiation of human dental pulp stem cells (hDPSCs) and mouse bone marrow stromal cells (mBMSCs). siRNA-mediated knockdown of CBFA2T2 blunted the BMP-2-induced allkaline phosphatase (ALP) activity, mineralization of extracelluar matrix (ECM), and expression of osteogenic related genes in both hDPSCs and mBMSCs. Mechanistically, knockdown of CBFA2T2 promoted expression of euchromatic histone methyltransferase 1 (EHMT1) in mBMSCs, which further led to upregulation of H3K9me2 levels at promoter of runt related transcription factor 2 (Runx2), the master regulator of osteogenesis. Collectively, our findings indicate that CBFA2T2 is required for BMP-2-induced osteogenic differentiation of MSCs through inhibition of EHMT1-mediated histone methylation at Runx2 promoter.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Knockdown of ARL4C inhibits osteogenic differentiation of human adipose-derived stem cells through disruption of the Wnt signaling pathway

Highlights: • Osteogenic differentiation of human adipose-derived stem cells was studied. • ARL4C is a regulator of osteogenic differentiation in vitro and in vivo. • ARL4C knockdown downregulates Wnt non-canonical pathway components. • Wnt canonical pathway protein LRP6 is downregulated in ARL4C knockdown cells. ADP-ribosylation factor-like 4C (ARL4C) has been shown to play an important role in cholesterol secretion, microtubule dynamics, and cell morphological changes. However, its role in osteogenesis has not been explored. In this study, we found that ARL4C is downregulated during the osteogenic differentiation of human adipose derived stem cells (hASCs). Knockdown of ARL4C suppresses osteogenesis of hASCs in vitro and in vivo. We demonstrate that ARL4C knockdown likely attenuates osteogenesis of hASCs through inhibition of the Wnt signaling pathway. These results provide new insights into the mechanisms of osteogenic differentiation and provide a potential molecular target for bone tissue engineering.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

miR-193a inhibits osteogenic differentiation of bone marrow-derived stroma cell via targeting HMGB1

Highlights: • miR-193a inhibits osteogenic differentiation of hBMSC. • miR-193a attenuates activation of MAPK and Wnt signaling pathway. • miR-193a suppresses osteogenic differentiation partially via HMGB1. • HMGB1 greatly rescues miR-193a-inhibited activation of MAPK and Wnt signaling pathway. miR-193a has been shown to be involved in a variety of biological processes, including cell proliferation, differentiation, and apoptosis. However, little is known about how miR-193a regulates osteogenic differentiation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Differential inhibition of mucin-type O-glycosylation (MTOG) induced by peracetyl N-thioglycolyl-d-galactosamine (Ac5GalNTGc) in myeloid cells

Highlights: • Each cell type expresses specific set of glycosyl transferases that result in unique pattern of mucin-type O-glycosylation. • MTOG of CD antigens is regulated depending on the specific cell type, developmental stage, and resting or activated state. • Metabolic incorporation of N-thioglycolyl-d-galactosamine results in cell-type dependent differential inhibition of MTOG. • Myeloid cells metabolize Ac{sub 5}GalNTGc with varying efficiency resulting in differential inhibition of MTOG on CD43. Investigations on the structure and functional roles of glycosylation – an intricate, complex, and dynamic post translational modification on proteins – in biological processes has been a challenging task. Glycan modifications vary depending on the specific cell type, its developmental stage, and resting or activated state. In the present study, we aim to understand the differences between the mucin-type O-glycosylation (MTOG) of two functionally divergent human cell lines, K562 (chronic myeloid leukemia) and U937 (histiocytic lymphoma), having myeloid origins. MTOG is initiated by the addition of N-acetyl-α-d-galactosamine (GalNAc) to Ser/Thr of glycoproteins. We exploited the metabolic glycan engineering (MGE) strategy using the peracetyl N-thioglycolyl-d-galactosamine (Ac{sub 5}GalNTGc), a synthetic GalNAc analogue, to engineer the glycoconjugates. Ac{sub 5}GalNTGc was metabolized and incorporated as N-thioglycolyl-d-galactosamine (GalNTGc) in cell surface glycoproteins in both the cell lines with varying degrees of efficiency. Notably, metabolic incorporation of GalNTGc resulted in differential inhibition of MTOG. It was observed that endogenous glycosylation machinery of K562 is relatively more stringent for selecting GalNTGc whereas U937 is flexible towards this selection. Additionally, we studied how the glycan modifications vary on a given CD antigen in these cell lines. Particularly, MTOG on CD43 was differentially inhibited in K562 and U937 as revealed by glycan-dependent and glycan-independent antibodies. It was observed that the effect of MGE on CD43 was similar to global effects on both cell lines. Consequences of MGE using GalNAc analogues depend on the expression and activity of various glycosyl transferases which determine global glycosylation on cell surface as well as on specific glycoproteins.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Long non-coding RNA, Bmcob, regulates osteoblastic differentiation of bone marrow mesenchymal stem cells

Disordered osteoblastic differentiation of bone marrow mesenchymal stem cells (BMSCs) contributes to bone loss. The underlying mechanisms are complicated and not fully understood. Long non-coding RNAs (lncRNAs) are emerging as an important regulatory factors on bone metabolism. Here, we discovered a novel lncRNA, Bmcob, which modulated osteogenic differentiation of primary mouse BMSCs. Expression levels of Bmcob were significantly upregulated in early-to-mid stages during osteoblast differentiation. Silencing of Bmcob suppressed osteoblastic differentiation of BMSCs in vitro, whereas its overexpression protected BMSCs from oxidative stress induced inhibition on osteogenesis. Subsequently, we discovered that selenoprotein P (Sepp1), which is located next to the Bmcob gene, was partly responsible for the regulatory effects of Bmcob. In addition, a series of selenoproteins were downregulated in BMSCs with Bmcob knockdown. Mechanistically, we found Bmcob was associated with selenocysteine insertion sequence binding protein 2 (SBP2), a critical trans-acting factor for selenoprotein synthesis. Finally, we suggest an explanatory hypothesis that through modulating nucleocytoplasmic shuttling of SBP2, Bmcob regulates a number of selenoproteins expression, including sepp1, and then mediates osteogenesis of BMSCs. Taken together, our results revealed a novel mechanism regulating osteogenesis of BMSCs and may function as a potential target for treating osteoporosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MLN64 deletion suppresses RANKL-induced osteoclastic differentiation and attenuates diabetic osteoporosis in streptozotocin (STZ)-induced mice

Highlights: • MLN64 knockdown inhibits RANKL-induced osteoclast differentiation. • MLN64 modulates inflammatory response in RANKL-induced osteoclast differentiation. • MLN64 deletion attenuates diabetic osteoporosis in STZ-induced mice. Diabetes mellitus is known as a main cause to induce osteoporosis. However, the pathogenesis of osteoporosis induced by diabetes has not been fully understood. MLN64 is highly homologous to the steroidogenic acute regulatory (STAR) protein, sharing the highly conserved START domain and exhibiting various biological activities. In the study, we attempted to explore the role of MLN64 in osteoporosis progression through the in vitro and in vivo studies. At first, the in vitro study suggested that MLN64 was over-expressed during the osteoclast differentiation induced by receptor activator of NF-kB ligand (RANKL). MLN64-knockdown markedly reduced the number of TRAP-positive multinucleated cells induced by RANKL, along with the down-regulation of specific genes related to osteoclastogenesis, including tartrate-resistant acid phosphatase (TRAP), nuclear factor of activated T cells (NFATc1), cathepsin K (CTSK), tartrate resistant (ACP5) and c-FOS and up-regulation of transcriptional receptor runt related transcription factor 2 (Runx2) and osteopontin (OPN). In contrast, over-expressing MLN64 significantly promoted the production of TRAP-positive multinucleated cells triggered by RANKL. Moreover, RANKL exposure led to remarkable increase in inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and MMP-1, which was attenuated by the knockdown of MLN64. Additionally, the expression of phosphorylated (p)IKKα, p-IκBα and p-nuclear factor (NF)-κB stimulated by RANKL was clearly alleviated by MLN64 silence. However, RANKL-induced inflammation was accelerated by MLN64 over-expression. Further, the in vivo study suggested that streptozotocin (STZ)-caused reduction in body weight of mice was improved by the loss of MLN64. STZ-induced diabetic mice exhibited higher levels of blood alkaline phosphatase (ALP) and TRAP, while being down-regulated in MLN64-knockout mice. MLN64 deletion reversed STZ-induced trabecular deleterious effects and stimulated bone remodeling. What's more, MLN64 knockout inhibited the expression levels of TRAP, RANKL and RANK in femoral heads of STZ mice, accompanied with the repression of inflammatory response. In conclusion, the results in our study suggested that MLN64 played a critical role in the meditation of osteoclastic differentiation, and its suppression alleviated diabetic osteoporosis in STZ-induced mice. Thus, MLN64 could be served as an essential target for developing effective therapeutic strategy to prevent diabetic osteoporosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Ambient ultrafine particles activate human monocytes: Effect of dose, differentiation state and age of donors

Highlights: • UFP causes TNF-α secretion independently of ROS formation. • Differentiated THP-1 cells are more responsive to UFP exposure. • Age of donor does not contribute to the proinflammatory effect of UFP. Exposure to ambient particulate matter (PM) has been linked to adverse pulmonary and cardiovascular health effects. Activation of both inflammatory and oxidative stress pathways has been observed and may be a probable cause of these outcomes. We tested the hypothesis that in human monocytes, PM-induced oxidative and inflammatory responses are interrelated. A human monocytic cell line (THP-1) was used to determine if dose and differentiation state plays a role in the cellular response after a 24hr exposure to particles. Primary human monocytes derived from eight female, non-smoker donors (aged: 21, 24, 27, 28, 48, 49, 54 & 60yo) were used to determine if the age of donors modulates the response. Cells were treated with aqueous suspensions of ambient ultrafine particles (UFP, defined as smaller than 0.2 µm in size) or a media control for 24hr. After exposure, reactive oxygen species (ROS) formation was increased irrespective of dose or differentiation state of THP-1 cells. In the primary human monocytes, ROS formation was not significantly changed. The release of the proinflammatory cytokine, tumor necrosis factor alpha (TNF-α), was dose-dependent and greatest in differentiated compared to undifferentiated THP-1 cells exposed to UFP. In the Primary human monocytes, TNF-α secretion was increased irrespective of the age of the donor. Our results suggest that after a 24hr exposure to particles, general reactive oxygen species formation was nonspecific and uncorrelated to cytokine secretion which was consistently enhanced. Cytokines play an important role in orchestrating many immune responses and thus the ability of ambient particles to enhance robust secretion of a proinflammatory cytokine from primary human monocytes, and how this may influence the response to pathogens and alter disease states, needs to be further evaluated.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

From stochastic processes to numerical methods: A new scheme for solving reaction subdiffusion fractional partial differential equations

We have introduced a new explicit numerical method, based on a discrete stochastic process, for solving a class of fractional partial differential equations that model reaction subdiffusion. The scheme is derived from the master equations for the evolution of the probability density of a sum of discrete time random walks. We show that the diffusion limit of the master equations recovers the fractional partial differential equation of interest. This limiting procedure guarantees the consistency of the numerical scheme. The positivity of the solution and stability results are simply obtained, provided that the underlying process is well posed. We also show that the method can be applied to standard reaction–diffusion equations. This work highlights the broader applicability of using discrete stochastic processes to provide numerical schemes for partial differential equations, including fractional partial differential equations.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2018

Influence of differential speed rolling ratio on the ridging behavior of ultra purified 17%Cr ferritic stainless steel

Highlights: • Differential rolling process improves ridging resistance of ferritic stainless steel. • Texture orientation inhomogeneity were attributed to non-uniform deformation. • Shear bands results in homogeneous deformation and recrystallization nucleation. • Uniform recrystallization grains and random orientation grains were obtained. - Abstract: The effect of the differential speed rolling on the ridging resistance and the crystallographic texture evolution of ultra purified 17%Cr ferritic stainless steel was investigated in order to select the optimal procedure for improving the surface quality. In the present study, the three different cold rolling processes were carried out: a conventional cold rolling and two different speed ratios asymmetric rolling. In the conventional cold rolling, the ridging of ferritic stainless steel was pronounced due to the band-like clusters of grains with similar crystallographic orientations. For differential speed rolling, ridging depth decreased and ridging was less pronounced when a higher different speed ratio was applied. The results show that severe ridging is attributed to the presence of band-like clusters of γ-fiber (<111>//ND) oriented grains. The shear bands introduced by differential speed rolling can enhance the nucleation for recrystallization both in grain interiors and grain boundaries, which can fragment the band-like clusters of similar orientation effectively, promoting the random grain orientation and improving surface quality.

36 MATERIALS SCIENCE↗
DOE OSTI2012

The role of DNA methylation in catechol-enhanced erythroid differentiation of K562 cells

Catechol is one of phenolic metabolites of benzene in vivo. Catechol is also widely used in pharmaceutical and chemical industries. In addition, fruits, vegetables and cigarette smoke also contain catechol. Our precious study showed that several benzene metabolites (phenol, hydroquinone, and 1,2,4-benzenetriol) inhibited erythroid differentiation of K562 cells. In present study, the effect of catechol on erythroid differentiation of K562 cells was investigated. Moreover, to address the role of DNA methylation in catechol-induced effect on erythroid differentiation in K562 cells, methylation levels of erythroid-specific genes were analyzed by Quantitative MassARRAY methylation analysis platform. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation in K562 cells in concentration- and time-dependent manners. The mRNA expression of erythroid specific genes, including α-globin, β-globin, γ-globin, erythroid 5-aminolevulinate synthase, erythroid porphobilinogen deaminase, and transcription factor GATA-1 genes, showed a significant concentration-dependent increase in catechol-treated K562 cells. The exposure to catechol caused a decrease in DNA methylation levels at a few CpG sites in some erythroid specific genes including α-globin, β-globin and erythroid porphobilinogen deaminase genes. These results indicated that catechol improved erythroid differentiation potency of K562 cells at least partly via up-regulating transcription of some erythroid related genes, and suggested that inhibition of DNA methylation might be involved in up-regulated expression of some erythroid related genes. -- Highlights: ► Catechol enhanced hemin-induced hemoglobin accumulation. ► Exposure to catechol resulted in up-regulated expression of erythroid genes. ► Catechol reduced methylation levels at some CpG sites in erythroid genes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium

Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10 μM Cd for 11 weeks (CTPE) or 5 μM iAs for 29 weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (> 25-fold) and S100P (> 40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (> 15-fold) and NTM (> 1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. - Highlights: • Cd and iAs are known human carcinogens, yet neither appears directly mutagenic. • Prior data suggest epigenetic modification plays a role in Cd or iAs induced cancer. • Altered methylation of four misregulated genes was found in Cd or iAs transformants. • The resulting altered gene expression may be relevant to cellular transformation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders. - Highlights: • An Alzheimer's disease model was successfully established by transfecting APP gene into neural stem cells in vitro. • Roles of osthole in experimental AD cells were studied. • Osthole promotes proliferation and differentiation into neurons and inhibits accumulation of Aβ{sub 1–42} peptide and apoptosis. • Osthole exerts protection via Wnt/β-catenin signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Pharmacological activation of aldehyde dehydrogenase 2 promotes osteoblast differentiation via bone morphogenetic protein-2 and induces bone anabolic effect

Aldehyde dehydrogenases (ALDHs) are a family of enzymes involved in detoxifying aldehydes. Previously, we reported that an ALDH inhibitor, disulfiram caused bone loss in rats and among ALDHs, osteoblast expressed only ALDH2. Loss-of-function mutation in ALDH2 gene is reported to cause bone loss in humans which suggested its importance in skeletal homeostasis. We thus studied whether activating ALDH2 by N-(1, 3-benzodioxol-5-ylmethyl)-2, 6-dichlorobenzamide (alda-1) had osteogenic effect. We found that alda-1 increased and acetaldehyde decreased the differentiation of rat primary osteoblasts and expressions of ALDH2 and bone morphogenetic protein-2 (BMP-2). Silencing ALDH2 in osteoblasts abolished the alda-1 effects. Further, alda-1 attenuated the acetaldehyde-induced lipid-peroxidation and oxidative stress. BMP-2 is essential for bone regeneration and alda-1 increased its expression in osteoblasts. We then showed that alda-1 (40 mg/kg dose) augmented bone regeneration at the fracture site with concomitant increase in BMP-2 protein compared with control. The osteogenic dose (40 mg/kg) of alda-1 attained a bone marrow concentration that was stimulatory for osteoblast differentiation, suggesting that the tissue concentration of alda-1 matched its pharmacologic effect. In addition, alda-1 promoted modeling-directed bone growth and peak bone mass achievement, and increased bone mass in adult rats which reiterated its osteogenic effect. In osteopenic ovariectomized (OVX) rats, alda-1 reversed trabecular osteopenia with attendant increase in serum osteogenic marker (procollagen type I N-terminal peptide) and decrease in oxidative stress. Alda-1 has no effect on liver and kidney function. We conclude that activating ALDH2 by alda-1 had an osteoanabolic effect involving increased osteoblastic BMP-2 production and decreased OVX-induced oxidative stress. - Highlights: • Alda-1 induced osteoblast differentiation that involved upregulation of ALDH2 and BMP-2 • Alda-1 attenuated acetaldehyde-induced inhibition of osteoblast differentiation • Alda-1 enhanced bone regeneration at the fracture site and peak bone mass achievement • Alda-1 reversed trabecular osteopenia in OVX rats via an osteoanabolic mechanism.

60 APPLIED LIFE SCIENCES↗