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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 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Usp7 promotes medulloblastoma cell survival and metastasis by activating Shh pathway

The ubiquitin-specific protease Usp7 plays roles in multiple cellular processes through deubiquitinating and stabilizing numerous substrates, including P53, Pten and Gli. Aberrant Usp7 activity has been implicated in many disorders and tumorigenesis, making it as a potential target for therapeutic intervention. Although it is clear that Usp7 is involved in many types of cancer, its role in regulating medulloblastoma (MB) is still unknown. In this study, we show that knockdown of Usp7 inhibits the proliferation and migration of MB cells, while Usp7 overexpression exerts an opposite effect. Furthermore, we establish Usp7 knockout MB cell line using the CRISPR/Cas9 system and further confirm that Usp7 knockout also blocks MB cell proliferation and metastasis. In addition, we reveal that knockdown of Usp7 compromises Shh pathway activity and decrease Gli protein levels, while P53 level and P53 target gene expression have no obvious changes. Finally, we find that Usp7 inhibitors apparently inhibit MB cell viability and migration. Taken together, our findings suggest that Usp7 is important for MB cell proliferation and metastasis by activating Shh pathway, and is a putative therapeutic target for MBs. - Highlights: • Loss of usp7 blocks the proliferation and metastasis of MB cells. • Usp7 regulates MB cell growth and migration through stimulating Shh pathway. • Usp7 inhibitors hamper MB cell proliferation and migration. • Usp7 inhibitors could attenuate Shh pathway activity.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Modulation of the sphingolipid rheostat is involved in paclitaxel resistance of the human prostate cancer cell line PC3-PR

Taxoids are anti-cancer drugs frequently used to treat solid tumors, but they are sometimes ineffective and tumors may become resistant to their action. Here, we examined the involvement of sphingolipid metabolic enzymes in paclitaxel (PTX) resistance using a human prostate cancer cell line, PC3, and its PTX-resistant subline, PC3-PR. PTX (20 nM) suppressed cell proliferation and increased various ceramide species in PC3, but not PC3-PR, cells. PC3-PR contained higher S1P levels than did PC3, regardless of PTX treatment. Western blotting revealed that PC3-PR cells expressed higher levels of sphingosine kinase 1 (SPHK1) and glucosylceramide synthase (GCS) but lower levels of acid sphingomyelinase (ASMase) and neutral sphingomyelinase 2 than did PC3 cells. Inhibition of SPHK1 using siRNA or a pharmacological inhibitor decreased S1P levels in PC3-PR cells and inhibited proliferation in the presence or absence of PTX, suggesting that SPHK1 is at least partially responsible for PTX resistance. Similarly, GCS inhibitors (PDMP and PPMP) increased cellular ceramides and suppressed the proliferation of PC3-PR. However, inhibition of proteasome function or histone deacetylase activity increased SMase and ceramide levels and suppressed PC3-PR proliferation. These results suggest that modulation of metabolic enzyme expression and alteration of the sphingolipid rheostat protects cancer cells against PTX. - Highlights: • S1P levels are higher in paclitaxel-resistant PC3-PR cells than in PC3 cells. • SPHK1 and GCS expression is higher in PC3-PR cells than in PC3 cells. • ASMase and NSMase2 expression is lower in PC3-PR cells than in PC3 cells. • SPHK1 and GCS inhibition blocks proliferation and increases ceramides in PC3-PR cells. • MG132 and TSA induce ASMase and NSMase2 expression and increase cellular ceramides.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

miR-141-3p functions as a tumor suppressor modulating activating transcription factor 5 in glioma

Glioma is the most common malignant primary brain tumor which arises from the central nervous system. Our studies reported that an anti-apoptotic factor, activating transcription factor 5 (ATF5), is highly expressed in malignant glioma specimens and cell lines. Downregulation by dominant-negetive ATF5 could repress glioma cell proliferation and accelerate apoptosis. Here, we further investigate the upstream factor which regulates ATF5 expression. Bioinformatic analysis showed that ATF5 was a potential target of miR-141-3p. Luciferase reporter assay verified that miR-141-3p specifically targeted the ATF5 3′-UTR in glioma cells. Functional studied suggested that miR-141-3p overexpression inhibited proliferation and promoted apoptosis of glioma cells (U87MG and U251). Xenograft experiments proved the inhibition of miR-141-3p on glioma growth in vivo. Moreover, exogenous ATF5 without 3′-UTR restored the cell proliferation inhibition triggered by miR-141-3p. Taken together, we put forward that miR-141-3p is a new upstream target towards ATF5. It can serve as a crucial tumor suppressor in regulating the ATF5-regulated growth of malignant glioma. - Highlights: • ATF5 was highly expressed in gliomas and was essential for cell proliferation and apoptosis. • MiR-141-3p specifically targeted the ATF5 3′-UTR in glioma cells. • MiR-141-3p was significantly downregulated in glioma tissues and cell lines. • MiR-141-3p inhibited glioma growth through repressing ATF5 expression in vitro and in vivo. • Exogenous expression of ATF5 rescued cells from proliferation inhibition triggered by miR-141-3p.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Etoposide induced NMI promotes cell apoptosis by activating the ARF-p53 signaling pathway in lung carcinoma

Highlights: • Etoposide inducescell apoptosis and increases the expression of NMI and ARF in A549 cells. • NMI positivelyregulates ARF protein expression and inhibits the cell proliferation. • Etoposide enhances the interaction between NMI and ARF andpromotes transcriptional activity ofp53. • Etoposide-induced NMI inhibits the proliferation and enhancesapoptosis by activating the p53 signaling. • Our results showed thatNMI has a critical role in suppressing lung carcinoma progression. Lung carcinoma is one of the leading causes of cancer-related death. The N-Myc and STATs interactor (NMI) has been reported to take participate in lots of physiological processes, but the involvement and functional mechanisms of NMI in lung carcinoma are poorly understood. In this study, we found that etoposide induces proliferation suppression, cell apoptosis and increases caspase-3 activity in A549 cells. Furthermore, etoposide treatment up-regulates the expression of NMI and ARF, enhances the interaction of NMI and ARF and promotes the p53 transcriptional activities. By contrast, when silencing NMI, the proliferation suppression and cell apoptosis caused by etoposide were repressed and the p53 signaling pathway activation was also suppressed. These investigations demonstrated etoposide-induced NMI can suppress tumor proliferation and promote cell apoptosis by activating the ARF-p53 signaling pathway in lung carcinoma. Our results provide an alternative mechanism for etoposide in lung carcinoma and suggest NMI has a critical role in suppressing lung carcinoma progression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Circular RNA circNASP modulates the malignant behaviors in osteosarcoma via miR-1253/FOXF1 pathway

Highlights: • circNASP knockdown suppressed OS cell proliferation and invasion. • circNASP acted as a sponge of miR-1253 targeting FOXF1. • miR-1253 inhibitor reversed the effects of circNASP knockdown in OS cells. • circNASP modulated OS cell proliferation and invasion by miR-1253/FOXF1 pathway. Increasing evidences demonstrate that circular RNAs (circRNAs) serve as essential regulators in various human diseases, including cancer. However, the study on circRNA function in osteosarcoma (OS) is just emerging. In the present study, we screened out a novel circRNA termed circNASP which was significantly upregulated in OS tissues compared to adjacent normal tissues. We found that circNASP knockdown dramatically inhibited the proliferation, cell cycle progression and invasion of OS cells. Moreover, we showed that circNASP expression was positively correlated with tumor size and metastasis in OS patients. In terms of mechanism, we found that circNASP acts as a sponge of miR-1253 targeting FOXF1 in OS cells. By inhibiting miR-1253 availability, circNASP promoted FOXF1 expression. Rescue assays indicated that inhibition of miR-1253 could significantly reverse the effects of circNASP knockdown on OS cell proliferation and invasion while restoration of FOXF1 rescued the proliferation and invasion of OS cells transfected with miR-1253 mimics. Taken together, our findings demonstrated that circNASP contributes to malignant behaviors of OS cells by miR-1253/FOXF1 pathway, which suggested circNASP/miR-1253/FOXF1axis might be a potential therapeutic target.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Effect of TCDD on the fate of epithelial cells isolated from human fetal palatal shelves (hFPECs)

Cleft palate is caused by the failure of palatal midline epithelial cells to disintegrate, which is necessary for palatal mesenchymal confluence. Although 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposure is linked to cleft palate at a high rate, the mechanism remains to be elucidated. The present study was designed to determine the effects of TCDD on the fate of epithelial cell isolated from human fetal palatal shelves (hFPECs). We demonstrate that TCDD increased cell proliferation and promoted the progression of cells from G1 to S phase as well as increased the number of cells entering the G2/M phase. We found that TCDD has no measurable effect on apoptosis of hFPECs. The protein level assays revealed that TCDD increased cyclin-dependent kinases 4 (cdk4), cyclin D1, cyclin E and p21 (Waf1/Cip1) but not cdk2, bcl-2, cyclin B1 and cyclin A. Furthermore, TCDD activated PI3K/AKT signaling, and the PI3K inhibitor, LY294002, partially abrogated TCDD-induced cell proliferation and gene modulations. TCDD treatment increased CYP1A1 mRNA and protein levels, which indicated the activation of AhR signaling. Knockdown of the AhR with siRNA suppressed TCDD-induced cell proliferation and PI3K/AKT signaling activation. Taken together, these data demonstrated that TCDD is able to promote growth of hFPECs through AhR-dependent activation of the PI3K/AKT pathway, which may account for the underlying mechanism by which TCDD causes a failure of palatal fusion. - Highlights: • TCDD promoted the cell growth with a character of significant accumulation of cells in G2/M. • TCDD treatment induced a various profile of cell cycle regulatory proteins. • PI3K/AKT pathway was involved in TCDD-induced cell proliferation and gene modifications. • AhR knockdown blocked TCDD-induced cell proliferation and PI3K/Akt signaling activation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Isoliquiritigenin exhibits anti-proliferative properties in the pituitary independent of estrogen receptor function

The plant flavonoid isoliquiritigenin (ISL) is a botanical estrogen widely taken as an herbal supplement to ease the symptoms of menopause. ISL has been also shown to have anti-tumor properties in a number of cancer cell backgrounds. However, the effects of ISL on normal cells are less well known and virtually unstudied in the context of the pituitary gland. We have established a pituitary explant culture model to screen chemical agents for gene expression changes within the pituitary gland during a period of active proliferation and differentiation. Using this whole-organ culture system we found ISL to be weakly estrogenic based on its ability to induce Cckar mRNA expression, an estrogen receptor (ER) mediated gene. Using a range of ISL from 200 nM to 200 μM, we discovered that ISL promoted cell proliferation at a low concentration, yet potently inhibited proliferation at the highest concentration. ICI 182,780 failed to antagonize ISL's repression of pituitary cell proliferation, indicating the effect is independent of ER signaling. Coincident with a decrease in proliferating cells, we observed down-regulation of transcript for cyclin D2 and E2 and a strong induction of mRNA and protein for the cyclin dependent kinase inhibitor Cdkn1a (p21). Importantly, high dose ISL did not alter the balance of progenitor vs. differentiated cell types within the pituitary explants and they seemed otherwise healthy; however, TUNEL staining revealed an increase in apoptotic cell death in ISL treated cultures. Our results merit further examination of ISL as an anti-tumor agent in the pituitary gland. - Highlights: • Isoliquiritigenin possesses weak estrogenic activity based on induction of Cckar. • ISL can be anti-proliferative in pituitary explants without altering cell lineages. • Anti-proliferative behavior of ISL is not estrogen receptor mediated. • ISL induces p21 expression leading to cell cycle arrest and apoptosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Msi2 plays a carcinogenic role in esophageal squamous cell carcinoma via regulation of the Wnt/β-catenin and Hedgehog signaling pathways

Highlights: • Msi2 is upregulated in ESCC tissues and cell lines. • Msi2 is associated with tumor progression and poor prognosis of ESCC patients. • Msi2 promotes ESCC cell proliferation, EMT and migration. • Msi2 functions by regulating the Wnt/β-catenin and Hh signaling pathways. Msi2 has been widely reported to be upregulated and strongly associated with fast progress and poor prognosis in many cancers. However, the expression and role of Msi2 in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we found that Msi2 was upregulated in ESCC clinical samples, and was significantly associated with tumor size, differentiation status, and lymph node metastasis in ESCC patients. Multivariate Cox regression analysis showed that Msi2 was an independent predictor for disease-free survival (DFS) and overall survival (OS). Moreover, knockdown of Msi2 impaired ESCC cell proliferation, epithelial-mesenchymal transition (EMT) and migration, while overexpression of Msi2 promoted ESCC cell proliferation, EMT and migration in vitro. Animal experiments also confirmed that Msi2 promoted ESCC cell proliferation in vivo. Mechanistically, Msi2 promoted ESCC cell proliferation, EMT and migration via regulation of the Wnt/β-catenin and Hedgehog (Hh) signaling pathways. Taken together, our study suggested that Msi2 could serve as a candidate for diagnosis and prognosis and as a potential therapeutic target in ESCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

SPARC is down-regulated by DNA methylation and functions as a tumor suppressor in T-cell lymphoma

Highlights: • SPARC is significantly down-regulated in T-NHL tissues and cell lines. • High levels of SPARC demonstrated a favorable clinical outcome. • SPARC inhibits proliferation, invasion and migration, but promotes apoptosis of T-NHL cells. • 5-Aza-Cdr inhibits proliferation, invasion and migration, but promotes apoptosis of T-NHL cells. The aim of this study was to assess the functional role of SPARC in T-cell non-Hodgkin's lymphoma (T-NHL), as well as the underlying molecular mechanisms. Here, we first identified SPARC expression in T-NHL tissues and cell lines through western blot and real-time PCR (RT-PCR). Overall survival of T-NHL patients with different levels of SPARC was assessed by Kaplan-Meier survival curves. Then cell proliferation, apoptosis, migration and invasion of T-NHL cells with either knockdown or overexpression of SPARC were determined by MTT, flow cytometry, transwell migration and invasion assay, respectively. Finally, the molecular mechanism by which SPARC modulated T-NHL cell progression was assessed. We confirmed that SPARC was significantly down-regulated in T-NHL tissues and cell lines. T-NHL patients with high levels of SPARC demonstrated a favorable clinical outcome. SPARC significantly suppressed cell proliferation, migration and invasion, and EMT process, but facilitated cell apoptosis in T-NHL cells. Further, we found that loss of SPARC expression in T-NHL tissues and cell lines, both in mRNA and protein levels, was associated with the aberrant DNA methylation in SPRAC gene, and the disrupted SPARC expression could be rescued after treatment with the demethylating agent 5-Aza-2′-deoxycitydine (5-Aza-Cdr). Additionally, 5-Aza-Cdr reversed SPARC hypermethylation to restore its biological role as a tumor suppressor in T-NHL cells, including inhibiting cell proliferation, invasion and migration, while promoting cell apoptosis. Our data provided evidence that DNA methylation in SPARC gene may play a role in the progression of T-NHL.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Deubiquitinating enzyme USP46 suppresses the progression of hepatocellular carcinoma by stabilizing MST1

Highlights: • Low USP46 level is correlated with poor prognosis in HCC. • USP46 suppresses the proliferation and metastasis of HCC. • USP46 suppress the progression of HCC by inhibiting the expression of YAP1. • MST1 mediates the regulation of USP46 on YAP1. • USP46 stabilized MST1 protein through inhibiting its ubiquitination and degradation. The deubiquitinating enzyme USP46 (ubiquitin-specific protease 46) is implicated in various cancers. However, its role and regulatory mechanism in HCC (hepatocellular carcinoma) are still unknown. In this study, we showed that USP46 is downregulated in HCC tissues and that low USP46 levels are associated with poor prognosis in HCC patients. In functional experiments, overexpression of USP46 impaired proliferation and metastasis of HCC cells, whereas knockdown of USP46 enhanced cell proliferation and invasiveness in vitro and in vivo. Furthermore, we found that USP46 suppresses HCC cell proliferation and metastasis by inhibiting YAP1. Ectopic expression of YAP1 rescued the inhibition of cell proliferation and metastasis caused by USP46 overexpression. Mechanistically, USP46 promotes the degradation of YAP1 by increasing expression of MST1, and the increase in MST1 protein antagonizes YAP1 to suppress HCC progression. Finally, we demonstrated that USP46 stabilizes the MST1 protein by directly binding to it and decreasing its ubiquitination. Taken together, our results demonstrated that USP46 may be a novel tumor suppressor in HCC. Moreover, USP46 acts as a deubiquitinating enzyme of MST1 to potentiate MST1 kinase activity to suppress tumor growth and metastasis, indicating that USP46 activation may represent a potential treatment strategy for HCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Long noncoding RNA H19-derived miR-675 aggravates restenosis by targeting PTEN

Highlights: • LncRNA H19 and miR-675 are positively correlated with restenosis. • LncRNA H19 promotes VSMCs proliferation. • LncRNA H19-derived miR-675 directly targets on PTEN. • LncRNA H19 aggravates restenosis in a miR-675-dependent manner. Restenosis is mainly attributed to excessive proliferation of vascular smooth muscle cells (VSMCs). Noncoding RNAs have been identified as key regulators of diverse pathological processes. We reported that the long noncoding RNA H19 (LncRNA H19) and LncRNA H19-derived microRNA (miR-675) are overexpressed in neointima of balloon-injured artery. Thus, the present study aims to evaluate the role of LncRNA H19 on VSMCs proliferation. To determine the changes of LncRNA H19 and miR-675 expression in the injured arterial wall, the standard rat carotid artery balloon injury model was used. In vivo studies demonstrated that both LncRNA H19 and miR-675 were upregulated after vascular injury. Correlation analysis revealed a positive relationship between LncRNA H19/miR-675 and the ratio of intima to media. Gain-of-function studies showed that the overexpression of LncRNA H19 accelerated T/G HA-VSMC proliferation in vitro. We further validated that PTEN is the target gene of miR-675 as demonstrated by luciferase assay. Finally, the results of the rescue experiment indicated that LncRNA H19 promoted the proliferation of T/G HA-VSMC in a miR-675-dependent manner. This finding not only reveal a novel function of LncRNA H19, but also has important diagnostic and therapeutic implications in the setting of restenosis and perhaps other vascular proliferative disorders as well.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Stearic acid suppresses mammary gland development by inhibiting PI3K/Akt signaling pathway through GPR120 in pubertal mice

It has been demonstrated that dietary high fat diet negatively affects the pubertal mammary gland development. The aim of the present study was to investigate the effects of stearic acid (SA), an 18-carbon chain saturated fatty acid, on mammary gland development in pubertal mice and to explore the underlying mechanism. Our results demonstrated that dietary supplementation of 2% SA suppressed mammary duct development, with significant reduction of terminal end bud (TEB) number and ductal branch. In accord, the expression of proliferative marker Cyclin D1 was markedly decreased by dietary SA. Furthermore, dietary SA led to increase of G protein-coupled receptor 120 (GPR120) expression and inhibition of PI3K/Akt signaling pathway in mammary gland of pubertal mice. In good agreement with the in vivo findings, the in vitro results showed that 40 μM SA significantly suppressed proliferation of mouse mammary epithelial cell HC11 by regulating mRNA and/or protein expression of proliferative markers such as Cyclin D1/3, p21, and PCNA. Meanwhile, SA activated GPR120 and inhibited PI3K/Akt signaling pathway in a GPR120-dependent manner. In addition, SA-induced inhibition of PI3K/Akt signaling pathway, suppression of HC11 proliferation, and alteration of proliferative markers expression were abolished by knockdown of GPR120 with siRNA. Collectively, these findings showed that SA suppressed mammary gland development of pubertal mice, which was coincident with the SA-inhibited HC11 proliferation, and was associated with inhibition of PI3K/Akt signaling pathway through activation of GPR120. These data provided new insights into the regulation of mammary gland development by dietary fatty acids. - Highlights: • Dietary supplementation of 2% SA suppressed mammary duct growth in pubertal mice. • SA inhibited HC11 proliferation by regulating expression of proliferative markers. • SA enhanced GPR120 and inhibited PI3K/Akt in mice mammary gland and HC11 cells. • Knockdown of GPR120 eliminated SA-suppressed PI3K/Akt and HC11 proliferation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

IGF2BP1 over-expression in skin squamous cell carcinoma cells is essential for cell growth

Highlights: • IGF2BP1 is upregulated in human skin squamous cell carcinoma (SCC) cells and tissues • IGF2BP1 shRNA or CRISPR/Cas9 knockout decreases levels of IGF2BP1-stablized mRNAs • IGF2BP1 shRNA or knockout inhibits human skin SCC cell survival and proliferation • Lnc-RNA THOR siRNA inhibits A431 cell survival and proliferation • IGF2BP1 silencing or knockout inhibits A431 xenograft growth in SCID mice The present study examined expression and potential functions of insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in human skin squamous cell carcinoma (SCC). We show that IGF2BP1 mRNA and protein expression levels were upregulated in established (A431 line) and primary human skin SCC cells. Its expression was also increased in human skin SCC tissues, as compared to the normal skin tissues. In skin SCC cells, IGF2BP1 silencing or CRISPR/Cas9 knockout decreased levels of IGF2BP1-stablized mRNAs, including IGF2, CD44, Gli1 and Myc. Furthermore, skin SCC cell survival and proliferation were inhibited by IGF2BP1 silencing/knockout. Conversely, forced over-expression of IGF2BP1 further promoted A431 cell survival and proliferation. Furthermore, siRNA-mediated knockdown of IGF2BP1-bound long non-coding RNA THOR (“Lnc-THOR”) similarly depleted IGF2BP1-dependent mRNAs, causing inhibition on A431 cell survival and proliferation. In vivo, IGF2BP1 silencing or knockout inhibited A431 tumor xenograft growth in mice. Together, we conclude that IGF2BP1 over-expression in skin SCC cells is essential for cell growth.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

ATP6V1H regulates the growth and differentiation of bone marrow stromal cells

Highlights: • Lack of ATP6V1H inhibits the proliferation of bone marrow stromal cells (BMSCs). • Partial loss of ATP6V1H inhibits osteogenic differentiation and promotes adipogenic differentiation of BMSCs. • ATP6V1H interacts with TGF-β receptor I and AP-2 complex to regulate the proliferation and differentiation of BMSCs. ATP6V1H encodes subunit H of vacuolar ATPase (V-ATPase) and may regulate osteoclastic function. The deficiency of ATP6V1H caused bone loss in human, mouse and zebrafish. In this report, we identified the mechanisms by which ATP6V1H regulates proliferation and differentiation of bone marrow stromal cells (BMSCs). We found that ATP6V1H was expressed in BMSCs, and Atp6v1h{sup +/-} BMSCs exhibited the lower proliferation rate, cell cycle arrest and reduced osteogenic differentiation capacity, as well as the increased adipogenic potentials. Histologic analysis confirmed less bone formation and more fatty degeneration in Atp6v1h{sup +/-} mice in the different age groups. Q-PCR analysis revealed that loss of ATP6V1H function downregulated the mRNA level of TGF-β1 receptor, and its binding molecule, subunit β of adaptor protein complex 2 (AP-2), suggesting ATP6V1H regulates the proliferation and differentiation of BMSCs by interacting with TGF-β receptor I and AP-2 complex.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

The atherogenic actions of LPC on vascular smooth muscle cells and its LPA receptor mediated mechanism

Lysophosphatidylcholine (LPC) is a bioactive lipid constituent of oxidized low density lipoprotein (ox-LDL). It regulates various cellular functions, including migration of circulating monocytes, expression of endothelial adhesion molecules, proliferation and migration of vascular smooth muscle cells (VSMCs). LPC can also be hydrolyzed into lysophosphatidic acid (LPA) by autotaxin (ATX) which possesses lysophospholipase D (lyso-PLD) activity. The aim of this study was to explore the effects of LPC on proliferation and migration of human artery smooth muscle cells (HASMCs) and the involvement of LPC-ATX-LPA pathway in these processes. In vitro, we found that LPC and LPA stimulated HASMCs proliferation and migration. Knockdown of LPA1 by siRNA and inhibit Gi protein with pertussis toxin (PTX) showed the contrary results. Silencing of LPC receptor genes did not significantly affect the LPC induced proliferation and migration. We detected the higher expressed mRNA and protein of ATX in HASMCs, and measured lyso-PLD activity. In atherosclerotic rabbit model, we observed high LPC level and high lyso-D activity in blood, and high expression of LPA1 in aorta walls. We also found that neointima appeared to be thickened and mRNA expressions of LPA1 appeared to be increased. These results revealed that LPC was converted into LPA by ATX to induce the proliferation and migration in HASMCs through LPA1/Gi/o/MAP Kinase signaling pathway. Our research suggested that LPC-ATX-LPA system contributed to the atherogenic action induced by ox-LDL. LPA1 antagonist may be considered as a potential therapeutic and preventative drug for cardiovascular disease.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Expansion of CD26 positive fibroblast population promotes keloid progression

Background: Keloid is a skin fibrosis disease that characterised by invasive growth of fibroblasts and aberrant deposition of extracellular matrix. Studies indicated that keloid fibroblasts (KFs) is a class of ‘activated’ fibroblasts, which show accelerated proliferation and excessive extracellular matrix formation as compared with normal fibroblasts (NFs). However, the mechanism underlying keloid fibroblasts dysfunction is still unknown. Objective: To verify CD26 expression difference between KFs and NFs, and investigate the function of CD26 positive fibroblasts in keloid progression. Methods: KFs and NFs were isolated from Keloid tissues and normal skin tissues respectively. Flow cytometry was performed to isolate CD26+/CD26- fibroblasts from KFs and NFs. Proliferation of different fibroblasts were analyzed by CCK8 assay and Ki 67 straining. Profibrotic phenotype difference was detected by qRT-PCR, western blot, ELISA and immunofluorescence. Scratching experiment and transwell assay were used to assess invasion ability of CD26+/CD26- fibroblasts. Diprotin A was used as a CD26 inhibitor to further investigated the function of CD26 fibroblasts in keloid disease. Result: CD26 expression was increased in KFs, and the proportion of CD26+ fibroblasts was significantly increased in KFs. Cell viability analysis showed that CD26+ fibroblasts was more active in proliferation. Furthermore, the expression of profibrotic genes were increased in CD26+ fibroblasts, including TGF-β1, IGF-1, IL6, collagen 1, collagen 3 and fibronectin. And meanwhile, CD26+ fibroblasts showed stronger invasion ability as compared to CD26- fibroblasts. Moreover, Diprotin A significantly suppressed proliferation and extracellular matrix secretion of CD26+ fibroblasts isolated from keloid tissues. Conclusion: Our findings suggest that CD26+ fibroblasts possess proliferation advantage in compare to CD26- fibroblasts, and the advantage caused expansion of CD26 positive fibroblast population promotes keloid progression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

RNA‐Seq analysis revealed the molecular mechanisms of photobiomodulation effect on human fibroblasts

Abstract Background The photobiomodulation (PBM) effect has been applied to various clinical therapy for a long time. However, the mechanism related to the PBM effect in terms of wavelengths has been lack of in‐depth study, except that ultraviolet radiation has attracted much attention due to its strong cell‐killing effect. Purpose To clarify the principle behind PBM and the main mechanism of improvement. Methods To carry on this study, we created light equipment using three LED chips, which emit 390 nm ultraviolet radiation, 415 nm blue light and 660 nm red light, respectively. We choose human fibroblasts (HF) to be irradiated by three different wavelengths for PBM test. In this study, we used cell counting kit (CCK‐8) test to show the cell proliferation roughly and reported on a systematic RNA sequencing (RNA‐seq) analysis at transcriptional expression levels from HF, which accepted PBM of different wavelengths of light. Results We found that 415 nm blue light inhibited cell proliferation and 660 nm red light stimulated cell proliferation while 390 nm ultraviolet radiation has little influence on cell proliferation. Furthermore, RNA‐seq results showed that CSF1R, PPP3CC, ITGAL, ITGAM, IL2RB, and several other differentially expressed genes (DEGs) are involved in the cell proliferation. Relative DEGs values for matrix metalloproteinases (MMPs) gene family have shown a great difference in blue and red light radiation especially on MMP25, MMP9, MMP21, and MMP13. Conclusion Taken together, the results provide a valuable resource to describe the variation of HFs under PBM of different light at gene level.

Li, Wenqi↗
DOE OSTI2016

Parabens and Human Epidermal Growth Factor Receptor Ligand Cross-Talk in Breast Cancer Cells

Background: Xenoestrogens are synthetic compounds that mimic endogenous estrogens by binding to and activating estrogen receptors. Exposure to estrogens and to some xenoestrogens has been associated with cell proliferation and an increased risk of breast cancer. Despite evidence of estrogenicity, parabens are among the most widely used xenoestrogens in cosmetics and personal care products and are generally considered safe. However, previous cell-based studies with parabens do not take into account the signaling cross-talk between estrogen receptor α (ERα) and the human epidermal growth factor receptor (HER) family. Objectives: We investigated the hypothesis that the potency of parabens can be increased with HER ligands, such as heregulin (HRG). Methods: The effects of HER ligands on paraben activation of c-Myc expression and cell proliferation were determined by real-time polymerase chain reaction, Western blots, flow cytometry, and chromatin immunoprecipitation assays in ERα- and HER2-positive human BT-474 breast cancer cells. Results: Butylparaben (BP) and HRG produced a synergistic increase in c-Myc mRNA and protein levels in BT-474 cells. Estrogen receptor antagonists blocked the synergistic increase in c-Myc protein levels. The combination of BP and HRG also stimulated proliferation of BT-474 cells compared with the effects of BP alone. HRG decreased the dose required for BP-mediated stimulation of c-Myc mRNA expression and cell proliferation. HRG caused the phosphorylation of serine 167 in ERα. BP and HRG produced a synergistic increase in ERα recruitment to the c-Myc gene. Conclusion: Our results show that HER ligands enhanced the potency of BP to stimulate oncogene expression and breast cancer cell proliferation in vitro via ERα, suggesting that parabens might be active at exposure levels not previously considered toxicologically relevant from studies testing their effects in isolation.

60 APPLIED LIFE SCIENCES↗