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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 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Sildenafil prevents the up-regulation of transient receptor potential canonical channels in the development of cardiomyocyte hypertrophy

Highlights: •Transient receptor potential canonical (TRPC1, 3 and 6) are up-regulated by ET-1. •Sildenafil inhibited hypertrophic responses (BNP, Ca entry, NFAT activation). •Sildenafil suppressed TRPC1, 3 and 6 expression. -- Abstract: Background: Transient receptor potential canonical (TRPCs) channels are up-regulated in the development of cardiac hypertrophy. Sildenafil inhibits TRPC6 activation and expression, leading to the prevention of cardiac hypertrophy. However, the effects of sildenafil on the expression of other TRPCs remain unknown. We hypothesized that in addition to its effects of TRPC6, sildenafil blocks the up-regulation of other TRPC channels to suppress cardiomyocyte hypertrophy. Methods and results: In cultured neonatal rat cardiomyocytes, a 48 h treatment with 10 nM endothelin (ET)-1 induced hypertrophic responses characterized by nuclear factor of activated T cells activation and enhancement of brain natriuretic peptide expression and cell surface area. Co-treatment with sildenafil (1 μM, 48 h) inhibited these ET-1-induced hypertrophic responses. Although ET-1 enhanced the gene expression of TRPCs, sildenafil inhibited the enhanced gene expression of TRPC1, C3 and C6. Moreover, co-treatment with sildenafil abolished the augmentation of SOCE in the hypertrophied cardiomyocytes. Conclusions: These results suggest that sildenafil inhibits cardiomyocyte hypertrophy by suppressing the up-regulation of TRPC expression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Procyanidin dimer B2-mediated IRAK-M induction negatively regulates TLR4 signaling in macrophages

Highlights: •Pro B2 elevated the expression of IRAK-M, a negative regulator of TLR signaling. •LPS-induced expression of cell surface molecules was inhibited by Pro B2. •LPS-induced production of pro-inflammatory cytokines was inhibited by Pro B2. •Pro B2 inhibited LPS-induced activation of MAPKs and NF-κB through IRAK-M. •Pro B2 inactivated naïve T cells by inhibiting LPS-induced cytokines via IRAK-M. -- Abstract: Polyphenolic compounds have been found to possess a wide range of physiological activities that may contribute to their beneficial effects against inflammation-related diseases; however, the molecular mechanisms underlying this anti-inflammatory activity are not completely characterized, and many features remain to be elucidated. In this study, we investigated the molecular basis for the down-regulation of toll-like receptor 4 (TLR4) signal transduction by procyanidin dimer B2 (Pro B2) in macrophages. Pro B2 markedly elevated the expression of the interleukin (IL)-1 receptor-associated kinase (IRAK)-M protein, a negative regulator of TLR signaling. Lipopolysaccharide (LPS)-induced expression of cell surface molecules (CD80, CD86, and MHC class I/II) and production of pro-inflammatory cytokines (tumor necrosis factor-α, IL-1β, IL-6, and IL-12p70) were inhibited by Pro B2, and this action was prevented by IRAK-M silencing. In addition, Pro B2-treated macrophages inhibited LPS-induced activation of mitogen-activated protein kinases such as extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase and the translocation of nuclear factor κB and p65 through IRAK-M. We also found that Pro B2-treated macrophages inactivated naïve T cells by inhibiting LPS-induced interferon-γ and IL-2 secretion through IRAK-M. These novel findings provide new insights into the understanding of negative regulatory mechanisms of the TLR4 signaling pathway and the immune-pharmacological role of Pro B2 in the immune response against the development and progression of many chronic diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Overexpression of Jazf1 reduces body weight gain and regulates lipid metabolism in high fat diet

Highlights: • The expression of Jazf1 in the liver suppressed lipid accumulation. • Jazf1 significantly increases transcription of fatty acid synthase. • Jazf1 plays a critical role in the regulation of energy and lipid homeostasis. • Jazf1 associates the development of metabolic disorder. • Jazf1 may provide a new therapeutic target in the management of metabolic disorder. - Abstract: Jazf1 is a 27 kDa nuclear protein containing three putative zinc finger motifs that is associated with diabetes mellitus and prostate cancer; however, little is known about the role that this gene plays in regulation of metabolism. Recent evidence indicates that Jazf1 transcription factors bind to the nuclear orphan receptor TR4. This receptor regulates PEPCK, the key enzyme involved in gluconeogenesis. To elucidate Jazf1’s role in metabolism, we fed a 60% fat diet for up to 15 weeks. In Jazf1 overexpression mice, weight gain was found to be significantly decreased. The expression of Jazf1 in the liver also suppressed lipid accumulation and decreased droplet size. These results suggest that Jazf1 plays a critical role in the regulation of lipid homeostasis. Finally, Jazf1 may provide a new therapeutic target in the management of obesity and diabetes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Accumulated SET protein up-regulates and interacts with hnRNPK, increasing its binding to nucleic acids, the Bcl-xS repression, and cellular proliferation

Highlights: • hnRNPK is a new target of SET. • SET regulates hnRNPK. • SET and hnRNPK accumulation promotes tumorigenesis. • SET accumulation is a potential model to study genes regulated by SET-hnRNPK. - Abstract: SET and hnRNPK are proteins involved in gene expression and regulation of cellular signaling. We previously demonstrated that SET accumulates in head and neck squamous cell carcinoma (HNSCC); hnRNPK is a prognostic marker in cancer. Here, we postulate that SET and hnRNPK proteins interact to promote tumorigenesis. We performed studies in HEK293 and HNSCC (HN6, HN12, and HN13) cell lines with SET/hnRNPK overexpression and knockdown, respectively. We found that SET and/or hnRNPK protein accumulation increased cellular proliferation. SET accumulation up-regulated hnRNPK mRNA and total/phosphorylated protein, promoted hnRNPK nuclear location, and reduced Bcl-x mRNA levels. SET protein directly interacted with hnRNPK, increasing both its binding to nucleic acids and Bcl-xS repression. We propose that hnRNPK should be a new target of SET and that SET–hnRNPK interaction, in turn, has potential implications in cell survival and malignant transformation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

JAZF1 can regulate the expression of lipid metabolic genes and inhibit lipid accumulation in adipocytes

Highlights: • JAZF1 was significantly upregulated during the differentiation of 3T3-L1 preadipocytes. • JAZF1 overexpression inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes. • JAZF1 overexpression inhibited the expression of SREBP1, ACC, and FAS. • JAZF1 overexpression upregulated the expression of HSL and ATGL. • SREBP1 and JAZF1 could regulate each other in adipocytes. - Abstract: JAZF1 is a newly identified gene with unknown functions. A recent genome-wide association study showed that JAZF1 is associated with type 2 diabetes and is highly expressed in liver and adipose tissue. Studies have demonstrated that JAZF1 is the co-repressor for nuclear orphan receptor TAK1, whereas most nuclear orphan receptor family members are involved in the regulation of lipid metabolism. Therefore, JAZF1 could be closely related to glycolipid metabolism. In this study, JAZF1 was significantly upregulated during the induced differentiation process of 3T3-L1 preadipocytes. The overexpression of JAZF1 inhibited lipid accumulation in differentiated mature 3T3-L1 adipocytes and significantly inhibited the expression of SREBPl, ACC, and FAS, which were important in lipid synthesis, while upregulating the expression of key enzyme hormone-sensitive lipase in lipoclasis. Moreover, SREBPl exhibited an inhibitory function on the expression of JAZF1. SREBP1 reversed the inhibitory action on lipid accumulation of JAZF1. SREBP1 and JAZF1 were observed to regulate each other in adipocytes. Therefore, JAZF1 could regulate the expression of particular genes related to lipid metabolism and inhibit lipid accumulation in adipocytes. This result suggests that JAZF1 may be a potential target for the treatment of diseases, such as obesity and lipid metabolism disorders.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Transcriptional regulation of miR-146b by C/EBPβ LAP2 in esophageal cancer cells

Highlights: • MiR-146b promotes esophageal cancer cell proliferation. • MiR-146b inhibits esophageal cancer cell apoptosis. • C/EBPβ directly binds to miR-146b promoter conserved region. • MiR-146b is up-regulated by C/EBPβ LAP2 transcriptional activation. - Abstract: Recent clinical study indicated that up-regulation of miR-146b was associated with poor overall survival of patients in esophageal squamous cell carcinoma. However, the underlying mechanism of miR-146b dysregulation remains to be explored. Here we report that miR-146b promotes cell proliferation and inhibits cell apoptosis in esophageal cancer cell lines. Mechanismly, two C/EBPβ binding motifs are located in the miR-146b promoter conserved region. Among the three isoforms of C/EBPβ, C/EBPβ LAP2 positively regulated miR-146b expression and increases miR-146b levels in a dose-dependent manner through transcription activation of miR-146b gene. Together, these results suggest a miR-146b regulatory mechanism involving C/EBPβ, which may contribute to the up-regulation of miR-146b in esophageal squamous cell carcinoma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

SAMHD1 is down regulated in lung cancer by methylation and inhibits tumor cell proliferation

Highlights: • SAMHD1 expression level is down regulated in lung adenocarcinoma. • The promoter of SAMHD1 is methylated in lung adenocarcinoma. • Over expression of SAMHD1 inhibits the proliferation of lung cancer cells. - Abstract: The function of dNTP hydrolase SAMHD1 as a viral restriction factor to inhibit the replication of several viruses in human immune cells was well established. However, its regulation and function in lung cancer have been elusive. Here, we report that SAMHD1 is down regulated both on protein and mRNA levels in lung adenocarcinoma compared to adjacent normal tissue. We also found that SAMHD1 promoter is highly methylated in lung adenocarcinoma, which may inhibit its gene expression. Furthermore, over expression of the SAMHD1 reduces dNTP level and inhibits the proliferation of lung tumor cells. These results reveal the regulation and function of SAMHD1 in lung cancer, which is important for the proliferation of lung tumor cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

PPARγ and MyoD are differentially regulated by myostatin in adipose-derived stem cells and muscle satellite cells

Myostatin (MSTN) is a secreted protein belonging to the transforming growth factor-β (TGF-β) family that is primarily expressed in skeletal muscle and also functions in adipocyte maturation. Studies have shown that MSTN can inhibit adipogenesis in muscle satellite cells (MSCs) but not in adipose-derived stem cells (ADSCs). However, the mechanism by which MSTN differently regulates adipogenesis in these two cell types remains unknown. Peroxisome proliferator-activated receptor-γ (PPARγ) and myogenic differentiation factor (MyoD) are two key transcription factors in fat and muscle cell development that influence adipogenesis. To investigate whether MSTN differentially regulates PPARγ and MyoD, we analyzed PPARγ and MyoD expression by assessing mRNA, protein and methylation levels in ADSCs and MSCs after treatment with 100 ng/mL MSTN for 0, 24, and 48 h. PPARγ mRNA levels were downregulated after 24 h and upregulated after 48 h of treatment in ADSCs, whereas in MSCs, PPARγ levels were downregulated at both time points. MyoD expression was significantly increased in ADSCs and decreased in MSCs. PPARγ and MyoD protein levels were upregulated in ADSCs and downregulated in MSCs. The CpG methylation levels of the PPARγ and MyoD promoters were decreased in ADSCs and increased in MSCs. Therefore, this study demonstrated that the different regulatory adipogenic roles of MSTN in ADSCs and MSCs act by differentially regulating PPARγ and MyoD expression. - Highlights: • PPARγ and MyoD mRNA and protein levels are upregulated by myostatin in ADSCs. • PPARγ and MyoD mRNA and protein levels are downregulated by myostatin in MSCs. • PPARγ exhibited different methylation levels in myostatin-treated ADSCs and MSCs. • MyoD exhibited different methylation levels in myostatin-treated ADSCs and MSCs. • PPARγ and MyoD are differentially regulated by myostatin in ADSCs and MSCs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Voluntary exercise prevents colonic inflammation in high-fat diet-induced obese mice by up-regulating PPAR-γ activity

Obesity is associated with increased colonic inflammation, which elevates the risk of colon cancer. Although exercise exerts anti-inflammatory actions in multiple chronic diseases associated with inflammation, it is unknown whether this strategy prevents colonic inflammation in obesity. We hypothesized that voluntary exercise would suppress colonic inflammation in high-fat diet (HFD)-induced obesity by modulation of peroxisome proliferator-activated receptor (PPAR)-γ. Male C57Bl/6J mice fed either a control diet (6.5% fat, CON) or a high-fat diet (24% fat, HFD) were divided into sedentary, voluntary exercise or voluntary exercise with PPAR-γ antagonist GW9662 (10 mg/kg/day). All interventions took place for 12 weeks. Compared with CON-sedentary group, HFD-sedentary mice gained significantly more body weight and exhibited metabolic disorders. Molecular studies revealed that HFD-sedentary mice had increased expression of inflammatory mediators and activation of nuclear factor (NF)-κB in the colons, which were associated with decreased expression and activity of PPAR-γ. Voluntary exercise markedly attenuated body weight gain, improved metabolic disorders, and normalized the expression of inflammatory mediators and activation of NF-κB in the colons in HFD-mice while having no effects in CON-animals. Moreover, voluntary exercise significantly increased expression and activity of PPAR-γ in the colons in both HFD- and CON-animals. However, all of these beneficial effects induced by voluntary exercise were abolished by GW9662, which inhibited expression and activity of PPAR-γ. The results suggest that decreased PPAR-γ activity in the colon of HFD-induced obesity may facilitate the inflammatory response and colon carcinogenesis. Voluntary exercise prevents colonic inflammation in HFD-induced obesity by up-regulating PPAR-γ activity. - Highlights: • Obesity down-regulates PPAR-γ in the colon. • Down-regulated colonic PPAR-γ may facilitate inflammatory response. • Exercise prevents colonic inflammation in obesity by up-regulating PPAR-γ.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Platelet-derived growth factor regulates vascular smooth muscle phenotype via mammalian target of rapamycin complex 1

Mammalian target of rapamycin complex (mTORC) regulates various cellular processes including proliferation, growth, migration and differentiation. In this study, we showed that mTORC1 regulates platelet-derived growth factor (PDGF)-induced phenotypic conversion of vascular smooth muscle cells (VSMCs). Stimulation of contractile VSMCs with PDGF significantly reduced the expression of contractile marker proteins in a time- and dose-dependent manner. In addition, angiotensin II (AngII)-induced contraction of VSMCs was completely blocked by the stimulation of VSMCs with PDGF. PDGF-dependent suppression of VSMC marker gene expression was significantly blocked by inhibition of phosphatidylinositol 3-kinase (PI3K), extracellular signal-regulated kinase (ERK), and mTOR whereas inhibition of p38 MAPK had no effect. In particular, inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked the PDGF-dependent phenotypic change of VSMCs whereas silencing of Rictor had no effect. In addition, loss of AngII-dependent contraction by PDGF was significantly retained by silencing of Raptor. Inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked PDGF-induced proliferation of VSMCs. Taken together, we suggest that mTORC1 plays an essential role in PDGF-dependent phenotypic changes of VSMCs. - Graphical abstract: Regulation of VSMC phenotype by PDGF-dependent activation of mTORC1. - Highlights: • The expression of contractile marker proteins was reduced by PDGF stimulation. • PDGF-dependent phenotypic conversion of VSMCs was blocked by inhibition of mTOR. • PDGF-induced proliferation of VSMCs was attenuated by inhibition of mTORC1. • mTORC1 plays a critical role in PDGF-dependent phenotypic conversion of VSMCs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Kibra and aPKC regulate starvation-induced autophagy in Drosophila

Autophagy is a bulk degradation system that functions in response to cellular stresses such as metabolic stress, endoplasmic reticulum stress, oxidative stress, and developmental processes. During autophagy, cytoplasmic components are captured in double-membrane vesicles called autophagosomes. The autophagosome fuses with the lysosome, producing a vacuole known as an autolysosome. The cellular components are degraded by lysosomal proteases and recycled. Autophagy is important for maintaining cellular homeostasis, and the process is evolutionarily conserved. Kibra is an upstream regulator of the hippo signaling pathway, which controls organ size by affecting cell growth, proliferation, and apoptosis. Kibra is mainly localized in the apical membrane domain of epithelial cells and acts as a scaffold protein. We found that Kibra is required for autophagy to function properly. The absence of Kibra caused defects in the formation of autophagic vesicles and autophagic degradation. We also found that the well-known cell polarity protein aPKC interacts with Kibra, and its activity affects autophagy upstream of Kibra. Constitutively active aPKC decreased autophagic vesicle formation and autophagic degradation. We confirmed the interaction between aPKC and Kibra in S2 cells and Drosophila larva. Taken together, our data suggest that Kibra and aPKC are essential for regulating starvation-induced autophagy. - Highlights: • Loss of Kibra causes defects in autophagosome formation and autophagic degradation. • Constitutively-active aPKCs negatively regulate autophagy. • Kibra interacts with aPKC in vitro and in vivo. • Kibra regulates autophagy downstream of aPKC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Ribosomal L1 domain and lysine-rich region are essential for CSIG/ RSL1D1 to regulate proliferation and senescence

The expression change of cellular senescence-associated genes is underlying the genetic foundation of cellular senescence. Using a suppressive subtractive hybridization system, we identified CSIG (cellular senescence-inhibited gene protein; RSL1D1) as a novel senescence-associated gene. CSIG is implicated in various process including cell cycle regulation, apoptosis, and tumor metastasis. We previously showed that CSIG plays an important role in regulating cell proliferation and cellular senescence progression through inhibiting PTEN, however, which domain or region of CSIG contributes to this function? To clarify this question, we investigated the functional importance of ribosomal L1 domain and lysine (Lys) -rich region of CSIG. The data showed that expression of CSIG potently reduced PTEN expression, increased cell proliferation rates, and reduced the senescent phenotype (lower SA-β-gal activity). By contrast, neither the expression of CSIG N- terminal (NT) fragment containing the ribosomal L1 domain nor C-terminal (CT) fragment containing Lys-rich region could significantly altered the levels of PTEN; instead of promoting cell proliferation and delaying cellular senescence, expression of CSIG-NT or CSIG-CT inhibited cell proliferation and accelerated cell senescence (increased SA-β-gal activity) compared to either CSIG over-expressing or control (empty vector transfected) cells. The further immunofluorescence analysis showed that CSIG-CT and CSIG-NT truncated proteins exhibited different subcellular distribution with that of wild-type CSIG. Conclusively, both ribosomal L1 domain and Lys-rich region of CSIG are critical for CSIG to act as a regulator of cell proliferation and cellular senescence. - Highlights: • The ribosomal L1 domain and lysine-rich region of CSIG were expressed. • They are critical for CSIG to regulate proliferation and senescence. • CSIG and its domains exhibit different subcellular distribution.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

High mobility group protein DSP1 negatively regulates HSP70 transcription in Crassostrea hongkongensis

HSP70 acts mostly as a molecular chaperone and plays important roles in facilitating the folding of nascent peptides as well as the refolding or degradation of the denatured proteins. Under stressed conditions, the expression level of HSP70 is upregulated significantly and rapidly, as is known to be achieved by various regulatory factors controlling the transcriptional level. In this study, a high mobility group protein DSP1 was identified by DNA-affinity purification from the nuclear extracts of Crassostrea hongkongensis using the ChHSP70 promoter as a bait. The specific interaction between the prokaryotically expressed ChDSP1 and the FITC-labeled ChHSP70 promoter was confirmed by EMSA analysis. ChDSP1 was shown to negatively regulate ChHSP70 promoter expression by Luciferase Reporter Assay in the heterologous HEK293T cells. Both ChHSP70 and ChDSP1 transcriptions were induced by either thermal or CdCl{sub 2} stress, while the accumulated expression peaks of ChDSP1 were always slightly delayed when compared with that of ChHSP70. This indicates that ChDSP1 is involved, very likely to exert its suppressive role, in the recovery of the ChHSP70 expression from the induced level to its original state. This study is the first to report negative regulator of HSP70 gene transcription, and provides novel insights into the mechanisms controlling heat shock protein expression. -- Highlights: •HMG protein ChDSP1 shows affinity to ChHSP70 promoter in Crassostrea hongkongensis. •ChDSP1 negatively regulates ChHSP70 transcription. •ChHSP70 and ChDSP1 transcriptions were coordinately induced by thermal/Cd stress. •ChDSP1 may contribute to the recovery of the induced ChHSP70 to its original state. •This is the first report regarding negative regulator of HSP70 transcription.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Hypoxic stress up-regulates Kir2.1 expression and facilitates cell proliferation in brain capillary endothelial cells

The blood-brain barrier (BBB) is mainly composed of brain capillary endothelial cells (BCECs), astrocytes and pericytes. Brain ischemia causes hypoxic encephalopathy and damages BBB. However, it remains still unclear how hypoxia affects BCECs. In the present study, t-BBEC117 cells, an immortalized bovine brain endothelial cell line, were cultured under hypoxic conditions at 4–5% oxygen for 72 h. This hypoxic stress caused hyperpolarization of resting membrane potential. Patch-clamp recordings revealed a marked increase in Ba{sup 2+}-sensitive inward rectifier K{sup +} current in t-BBEC117 cells after hypoxic culture. Western blot and real-time PCR analyses showed that Kir2.1 expression was significantly up-regulated at protein level but not at mRNA level after the hypoxic culture. Ca{sup 2+} imaging study revealed that the hypoxic stress enhanced store-operated Ca{sup 2+} (SOC) entry, which was significantly reduced in the presence of 100 μM Ba{sup 2+}. On the other hand, the expression of SOC channels such as Orai1, Orai2, and transient receptor potential channels was not affected by hypoxic stress. MTT assay showed that the hypoxic stress significantly enhanced t-BBEC117 cell proliferation, which was inhibited by approximately 60% in the presence of 100 μM Ba{sup 2+}. We first show here that moderate cellular stress by cultivation under hypoxic conditions hyperpolarizes membrane potential via the up-regulation of functional Kir2.1 expression and presumably enhances Ca{sup 2+} entry, resulting in the facilitation of BCEC proliferation. These findings suggest potential roles of Kir2.1 expression in functional changes of BCECs in BBB following ischemia. -- Highlights: •Hypoxic culture of brain endothelial cells (BEC) caused membrane hyperpolarization. •This hyperpolarization was due to the increased expression of Kir2.1 channels. •Hypoxia enhanced store-operated Ca{sup 2+} (SOC) entry via Kir2.1 up-regulation. •Expression levels of putative SOC channels were not affected by hypoxia. •Kir2.1 up-regulation is responsible for hypoxia-enhanced BEC proliferation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Androgen-androgen receptor system improves chronic inflammatory conditions by suppressing monocyte chemoattractant protein-1 gene expression in adipocytes via transcriptional regulation

Age-related decreases in sex hormones are closely related to chronic inflammation in obesity and metabolic diseases. Particularly, the molecular basis of androgen activity in regulating inflammation and controlling metabolism remains largely unknown. Obese adipocytes secrete monocyte chemoattractant protein-1 (MCP-1), a key chemokine that promotes the infiltration of monocytes/macrophages into adipose tissue, thereby leading to metabolic disorders. Here, we studied the role of androgen-androgen receptor (AR) action in regulating MCP-1 expression in adipose tissue. We observed the induction of Mcp-1 expression in 3T3-L1 adipocytes co-cultured with RAW264.7 macrophages. Additionally, Mcp-1 expression was upregulated by culturing in conditioned medium derived from inflammatory macrophages (M1-Mφ) containing tumor necrosis factor-alpha (TNF-α). We found that sex hormones downregulated TNF-α-induced Mcp-1 and interleukin (Il)-6 expression in 3T3-L1 adipocytes. Furthermore, luciferase-reporter analysis indicated that MCP-1 promoter activity was predominantly suppressed by dihydrotestosterone (DHT)-AR interactions through functional canonical nuclear factor-kappa B (NF-κB) sites, whereas non-canonical NF-κB site containing important flanking sequences exhibited minor contributions to DHT-AR transcriptional repression. These findings suggested that androgen-AR suppressed obesity-induced chronic inflammation in adipose tissue. - Highlights: • DHT, non-aromatizable androgen suppresses Mcp-1 expression in adipocytes. • Mcp-1 transcription was negatively regulated by DHT-AR action. • DHT-AR selectively regulates Mcp-1 transcription through distinct NF-κB sites.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

The E3 ubiquitin ligase CHIP selectively regulates mutant epidermal growth factor receptor by ubiquitination and degradation

Somatic mutation in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) is a decisive factor for the therapeutic response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in lung adenocarcinoma. The stability of mutant EGFR is maintained by various regulators, including heat shock protein 90 (Hsp90). The C terminus of Hsc70-interacting protein (CHIP) is a Hsp70/Hsp90 co-chaperone and exhibits E3 ubiquitin ligase activity. The high-affinity Hsp90-CHIP complex recognizes and selectively regulates their client proteins. CHIP also works with its own E3 ligase activity independently of Hsp70/Hsp90. Here, we investigated the role of CHIP in regulating EGFR in lung adenocarcinoma and also evaluated the specificity of CHIP's effects on mutant EGFR. In HEK 293T cells transfected with either WT EGFR or EGFR mutants, the overexpression of CHIP selectively decreased the expression of certain EGFR mutants (G719S, L747-E749del A750P and L858R) but not WT EGFR. In a pull-down assay, CHIP selectively interacted with EGFR mutants and simultaneously induced their ubiquitination and proteasomal degradation. The expressions of mutant EGFR in PC9 and H1975 were diminished by CHIP, while the expression of WT EGFR in A549 was nearly not affected. In addition, CHIP overexpression inhibited cell proliferation and xenograft's tumor growth of EGFR mutant cell lines, but not WT EGFR cell lines. EGFR mutant specific ubiquitination by CHIP may provide a crucial regulating mechanism for EGFR in lung adenocarcinoma. Our results suggest that CHIP can be novel therapeutic target for overcoming the EGFR TKI resistance. - Highlights: • CHIP selectively interacts with EGFR mutants. • CHIP-EGFP mutant interactions lead to ubiquitination and degradation of EGFR mutants. • CHIP selectively inhibits the proliferation and tumorigenicity in EGFR mutant cells. • We propose a novel mutant EGFR targeting by CHIP in lung adenocarcinoma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Metabolic pathways regulated by p63

The transcription factor p63 belongs to the p53-family and is a master regulator of proliferative potential, lineage specification, and differentiation in epithelia during development and tissue homeostasis. In cancer, p63 contribution is isoform-specific, with both oncogenic and tumour suppressive roles attributed, for ΔNp63 and TAp63, respectively. Recently, p53 and TAp73, in line with other tumour suppressor genes, have emerged as important regulators of energy metabolism and metabolic reprogramming in cancer. To date, p63 contributions in controlling energy metabolism have been partially investigated; given the extensive interaction of the p53 family members, these studies have potential implications in tumour cells for metabolic reprogramming. Here, we review the role of p63 isoforms, TAp63 and ΔNp63, in controlling cell metabolism, focusing on their specific metabolic target genes and their physiological/functional context of action. - Highlights: • The transcription factor p63 is involved in development and cancer. • p63 regulates glucose and lipid metabolism. • p63 contributes to anti-oxidant defences. • p63 regulates metabolism of cancer cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

SPOCK1 is up-regulated and promotes tumor growth via the PI3K/AKT signaling pathway in colorectal cancer

SPOCK1 encodes a Ca{sup 2+}-binding matricellular glycoprotein which plays an oncogenic role in cancer cells. However, the role of SPOCK1 in the pathogenesis of colorectal cancer (CRC) has not been determined. Here, SPOCK1 was found higher expressed in CRC tissues than that of adjacent normal tissues. Furthermore, up-regulated expression of SPOCK1 in CRC patients was associated with tumor size and TNM stage. In addition, we observed that the depletion of SPOCK1 inhibited proliferation in vitro and tumorigenicity in vivo and promoted apoptosis in cell culture. Our data suggest that inactivation of PI3K/Akt signaling pathway was involved in down-regulation of SPOCK1-mediated suppression of tumor cell proliferation. These results suggest that SPOCK1 expression is correlated with malignant features of CRC and may serve as potential therapeutic and preventive strategies for CRC. - Highlights: • SPOCK1 expression is significantly up-regulated in CRC tissues and associated with tumor size and TMN stage. • Down-regulation of SPOCK1 suppresses CRC cell proliferation both in vitro and in vivo. • SPOCK1 stimulates the PI3K/AKT signaling pathway to inhibit cell apoptosis and promote tumor growth.

60 APPLIED LIFE SCIENCES↗