Fibroblast Growth Factor mRNA Levels Research Articles

FGF2 promotes the chemotherapy resistance in colon cancer cells through activating PI3K/Akt signaling pathway

Abstract Background To investigate the role of fibroblast growth factor 2 (FGF2) in chemotherapy resistance of colon cancer. Methods An HCT116/5-fluorouracil (5-FU)–resistant cell line was established, and FGF2 levels were detected in a sensitive cell group (HCT116) and a resistant cell group (HCT1116-R) using different methods. Fibroblast growth factor 2 levels in the medium were determined by enzyme-linked immunoassay. The protein expressions of FGF2, fibroblast growth factor receptor 1 (FGFR1), and phospho-FGFR1 were assessed by Western blotting, and FGF2 mRNA levels were detected by quantitative real-time polymerase chain reaction. Fibroblast growth factor 2 recombinant protein was added to sensitive cells, and FGFR inhibitor AZD4547 was added to resistant cells, and the cell survival rate was determined using the cell counting kit-8 method and the protein expressions of PI3K (phosphatidylinositol 3 kinase), p-PI3K (phospho-PI3K), Akt (protein kinase B), p-Akt (phospho-Akt), mammalian target of rapamycin (mTOR), p-mTOR (phospho-mTOR), Bad (Bcl-xL/Bcl-2–associated death promoter), NF-κB (nuclear factor κB), GSK-3 (glycogen synthase kinase-3), FKHR (forkhead box protein O1), and PTEN (phosphatase and tensin homolog deleted on chromosome ten) were detected by Western blotting. Results Fibroblast growth factor 2 protein and mRNA expression levels in the HCT116-R group were significantly higher than those in the HCT116 group. Fibroblast growth factor 2 increased the survival rate of HCT116 cells; improved tolerance to 5-FU; upregulated p-PI3K, p-Akt, and p-mTOR; and downregulated Bad. The FGFR inhibitor AZD4547 decreased cell survival rate and tolerance to 5-FU; downregulated p-PI3K, p-Akt, and p-mTOR expression; and upregulated Bad. Conclusions Fibroblast growth factor 2 promotes chemotherapy tolerance in colon cancer cells by activating the Akt/mTOR and Akt/Bad signaling pathways downstream of PI3K.

Investigation of FGF21 mRNA levels and relative mitochondrial DNA copy number levels and their relation in nonalcoholic fatty liver disease: a case-control study.

Background: Although the exact mechanisms of nonalcoholic fatty liver disease (NAFLD) are not fully understood, numerous pieces of evidence show that the variations in mitochondrial DNA (mtDNA) level and hepatic Fibroblast growth factor 21 (FGF21) expression may be related to NAFLD susceptibility. Objectives: The main objective of this study was to determine relative levels of mtDNA copy number and hepatic FGF21 expression in a cohort of Iranian NAFLD patients and evaluate the possible relationship. Methods: This study included 27 NAFLD patients (10 with nonalcoholic fatty liver (NAFL) and 17 with non-alcoholic steatohepatitis (NASH)) and ten healthy subjects. Total RNA and genomic DNA were extracted from liver tissue samples, and then mtDNA copy number and FGF21 expression levels were assessed by quantitative real-time PCR. Results: The relative level of hepatic mtDNA copy number was 3.9-fold higher in patients than in controls (p < 0.0001). NAFLD patients showed a 2.9-fold increase in hepatic FGF21 expression compared to controls (p < 0.013). Results showed that hepatic FGF21 expression was positively correlated with BMI, serum ALT, and AST levels (p < 0.05). The level of mitochondrial copy number and hepatic FGF21 expression was not significantly associated with stages of change in hepatic steatosis. Finally, there was a significant correlation between FGF21 expression and mitochondrial copy number in NAFLD patients (p = 0.027). Conclusion: Our findings suggest a considerable rise of hepatic FGF21 mRNA levels and mtDNA-CN and show a positive correlation between them in the liver tissue of NAFLD patients.

Upregulation of fibroblast growth factor 2 contributes to endometriosis through SPRYs/DUSP6/ERK signaling pathway

Previous studies report that fibroblast growth factor 2 (FGF2) modulates Sproutys (SPRYs)/dual specificity phosphatase 6 (DUSP6)/extracellular signal-regulated kinase (ERK) signaling pathway in endometrial glandular epithelial cells. However, its role in endometriosis remains unclear. The expression patterns and localization of related proteins in endometrium patients’ samples were determined using quantitative reverse transcription PCR, Western blotting, and immunohistochemistry, respectively. Human endometrial stromal cells (HESCs) were isolated and transfected with small interfering RNA (siRNA) targeting FGF2 (FGF2-siRNA). Cell viability was determined using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. It was found that FGF2 mRNA and protein levels were increased in the ectopic endometrium, whilst the mRNA and protein levels of SPRYs/DUSP6/ERK signaling pathway related-genes were dysregulated. Spearman’s rank correlation analysis revealed a negative correlation between FGF2 and SPRYs/DUSP6 signaling pathway-related proteins. In vitro study demonstrated that FGF2 silencing suppressed cell proliferation. Our results suggest that FGF2 upregulation might contribute to endometriosis via the regulation of the SPRYs/DUSP6/ERK signaling pathway.

Complement-mediated release of fibroblast growth factor 2 from human RPE cells

PurposeComplement activation is associated with choroidal neovascularization (CNV) in age-related macular degeneration (AMD). Fibroblast growth factor 2 (FGF2) and membrane attack complex (MAC) are present in eyes of patients with CNV. Herein, we investigated the effect of complement activation on FGF2 release in human retinal pigment epithelial (RPE) cells. MethodsCultured human RPE cells were primed with an anti-RPE antibody and then treated with C1q-depleted human serum in the presence or absence of Tec kinases inhibitor (LFM-A13). 38 cytokines/chemokines levels were measured by Luminex technology. Secretion of FGF2 and interleukin (IL)-6 was assessed by ELISA. Tec protein was measured by Western blot. mRNA expression of FGF2, chemokine (C-X-C motif) ligand 1 (CXCL-1), and family members of Tec kinases was evaluated by qPCR. Cell viability and MAC deposition were determined by WST-1 assay and flow cytometry, respectively. ResultsComplement activation caused increased FGF2 and IL-6 release. FGF2 was released when C6-depleted human serum was reconstituted with C6. Anti-C5 antibody significantly attenuated complement-mediated FGF2 release, but not IL-6. FGF2 mRNA levels were not affected, while CXCL-1 mRNA levels were increased by complement activation. FGF2-containing extracellular vesicles were detected in response to complement challenge. Tec mRNA and protein were expressed in RPE cells. In the presence of LFM-A13, secretion of FGF2, but not IL-6, and MAC deposition were significantly decreased and cell viability was significantly increased in complement-treated cells when compared to controls. ConclusionsComplement plays an important role to release FGF2 from RPE cells. Tec kinase is involved in MAC formation and complement-mediated FGF2 release. This information suggests a role for complement activation to mediate neovascularization in conditions such as AMD, and may elucidate potential therapeutic targets.

Fibroblast growth factor 2 conjugated superparamagnetic iron oxide nanoparticles (FGF2-SPIONs) ameliorate hepatic stellate cells activation in vitro and acute liver injury in vivo

Liver diseases are the growing health problem with no clinically approved therapy available. Activated hepatic stellate cells (HSCs) are the key driver cells responsible for extracellular matrix deposition, the hallmark of liver fibrosis. Fibroblast growth factor 2 (FGF2) has shown to possess anti-fibrotic effects in fibrotic diseases including liver fibosis, and promote tissue regeneration. Among the fibroblast growth factor receptors (FGFRs), FGF2 interact primarily with FGFR1, highly overexpressed on activated HSCs, and inhibit HSCs activation. However, FGF2 poses several limitations including poor systemic half-life and stability owing to enzymatic degradation. The aim of this study is to improve the stability and half-life of FGF2 thereby improving the therapuetic efficacy of FGF2 for the treatment of liver fibrosis. We found that FGFR1-3 mRNA levels were overexpressed in cirrhotic human livers, while FGFR1c, 2c, 3c, 4 and FGF2 mRNA levels were overexpressed in TGFβ-activated HSCs (LX2 cells) and FGFR1 protein expression was highly increased in TGFβ-activated HSCs. Treatment with FGF2 inhibited TGFβ-induced HSCs activation, migration and contraction in vitro. FGF2 was conjugated to superparamagnetic iron-oxide nanoparticles (SPIONs) using carbodiimide chemistry, and the resulting FGF2-SPIONs were confirmed by dynamic light scattering (DLS), zeta potential, dot-blot analysis and Prussian Blue iron-staining. In vitro, treatment with FGF2-SPIONs evidenced increased therapeutic effects (attenuated TGFβ-induced HSCs activation, migration and contraction) of FGF2 in TGFβ-activated HSCs and ameliorated early liver fibrogenesis in vivo in acute carbon tetrachloride (CCl4)-induced liver injury mouse model. In contrast, free FGF2 showed no significant effects in vivo. Altogether, this study presents a promising therapeutic approach using FGF2-SPIONs for the treatment of liver fibrosis.

233-LB: Spinal Cord Injury Inhibited-FGF21 Signaling Is Associated with Dysregulation of Metabolic Gene Expression in Mouse Liver and Adipose Tissue

Spinal cord injury (SCI) causes deleterious changes in the metabolic profile due to muscle atrophy and sedentary lifestyle. SCI is associated with increased risk for cardiovascular disease, liver disorders and type 2 diabetes mellitus (T2DM). Understanding of the mechanisms for these disorders in those with SCI is poor. Fibroblast growth factor 21 (FGF-21), a hepatic hormone, is reported to have beneficial effects on glucose/lipid metabolism in animal models and human subjects with T2DM. However, the expression levels and the potential effect of FGF-21 on SCI related metabolic dysfunction have not been studied. To address this issue, we compared FGF-21 serum and hepatic mRNA levels in sham and SCI mice fed control or high fat diet (HFD) at 84d after SCI. SCI reduced serum FGF-21 levels by 60% and hepatic FGF-21 mRNA levels by 50% compared to sham mice; levels were further suppressed by HFD. These changes were associated with elevated serum levels of alanine aminotransferase, a liver damage marker. In adipose tissue (AT), SCI decreased mRNA expression of FGF-21 receptor (FGFR1), β-Klotho, adiponectin, PPARγ, and leptin. In addition, SCI reduced IRS1 and Glut4 mRNA levels in AT, indicating impaired insulin signaling. Moreover, elevated levels of TNFα in AT and CD11b (a macrophage marker) in the liver were observed, implying a proinflammatory state after SCI. Finally, post-SCI mice fed a HFD had elevated free fatty acid (FFA) levels in serum and liver compared to sham-mice fed a HFD, suggesting defective FFA uptake and metabolism. These data suggest that reduced FGF-21 signaling after SCI may, at least in part, be contributing to the metabolic dysfunction after SCI, and that FGF-21 may be a candidate for the treatment of SCI-related metabolic dysfunction. Disclosure X. Liu: None. L. Harlow: None. Z. Graham: None. J.F. Yarrow: None. K. Cusi: Consultant; Self; Allergan plc., AstraZeneca, Bristol-Myers Squibb, Genentech, Inc., Gilead Sciences, Inc., Merck &amp; Co., Inc. Research Support; Self; Cirius Therapeutics, Echosens, Eli Lilly and Company, Inventiva Pharma, Janssen Pharmaceuticals, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Poxel SA, Zydus Pharmaceuticals, Inc. W.A. Bauman: None. C.P. Cardozo: None. Funding U.S. Department of Veterans Affairs (B9212C, B2020C)

Accelerated healing by topical administration of Salvia officinalis essential oil on Pseudomonas aeruginosa and Staphylococcus aureus infected wound model

BackgroundSalvia officinalis L. (Lamiaceae) is known to have antibacterial properties possibly conducive to the healing process of infected wounds. PurposeThe present study aimed to evaluate the effects of an ointment containing Salvia officinalis essential oil (SOO) on an infected wound model. MethodsEssential oil hydrodistillated from the dried leaves of the plant was analyzed by GC-FID and GC–MS. After creating two full-thickness cutaneous wounds, mice were classified into four groups, control, and animals treated with 2 % mupirocin® (standard positive drug), and 2 % and 4 % (w/w) of SOO. In order to evaluate the effects of SOO on the wound healing phases, the expression levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), cyclin-D1, Bcl-2, fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factors (VEGF) were analyzed using qRT-PCR. Immunohistochemistry analysis, tissue total antioxidant capacity (TAC) and malondialdehyde (MDA) were further assessed in all groups. ResultsConcerning essential oil, the main compounds were found to be cis-thujone (26.8 %), camphor (16.4 %), trans-thujone (14.1 %) and 1,8-cineole (10.8 %). Our findings showed that the topical application of SOO was able to shorten the inflammatory phase and accelerate the cellular proliferation, re-vascularization, collagen deposition and re-epithelialization in comparison to the control group (p < 0.05). Moreover, increased mRNA levels of FGF-2 and VEGF, and up-regulation of cyclin-D1 and Bcl-2 were observed following the topical application of SOO compared to the control group (p < 0.05). The expression levels of IL-6, IL-1β and TNF-α were reduced in animals treated with SOO on days 3, 7 and 14 (p < 0.05). ConclusionsAdministration of SOO increased the TAC level and reduced the MDA content and levels of IL-1β and TNF-α. It is concluded that SOO is able to accelerate the wound healing process by regulating the expression of pro-inflammatory cytokines, growth factors, and antioxidant properties.

Topical application of Cinnamon verum essential oil accelerates infected wound healing process by increasing tissue antioxidant capacity and keratin biosynthesis.

Cinnamon essential oil is known to have antioxidant and antibacterial properties, which may accelerate, wound healing. This study was conducted to evaluate the effects of an ointment prepared from Cinnamon verum essential oil (C verum) in infected wound model. An experimentally excisional infected wound model was induced in mice. Circular excisional wound model of 5 mm surface area was surgically created and inoculated with 107 CFU of each of two bacterial strains of Staphylococcus aureus and Pseudomonas aeruginosa. The animals were divided into three groups and topically treated with soft yellow paraffin (control) and ointments containing 2% and 4% C verum. The mRNA levels of insulin-like growth factor I (IGF-1), fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF), epidermal keratin, fibroblasts, fibrocytes, immune cells, and vascular distribution as well as epithelialization ratio were investigated in order to evaluate the effects of C verum on wound healing. Tissue total antioxidant capacity and malondialdehyde levels (MDA) were also evaluated. Topical administration of C verum remarkably shortened the inflammatory phase, increased fibroblast distribution, collagen deposition, and accelerated the cellular proliferation, reepithelialization and keratin synthesis. The mRNA levels of IGF-1, FGF-2 and VEGF were remarkably higher in C verum-treated groups (especially 2%) in comparison control group. Topical administration of C verum increased antioxidant power and reduced MDA content in comparison to control animals. C verum accelerates wound healing by upregulating the IGF-1, FGF-2, and VEGF expression and increasing cell proliferation, collagen synthesis, and reepithelialization ratio.

Fibroblast growth factor 21, adiposity, and macronutrient balance in a healthy, pregnant population with overweight and obesity

ABSTRACTAim of the study: The regulation and actions of fibroblast growth factor 21 (FGF21) are responsive to energy status and macronutrient balance, and investigations of FGF21 in normal pregnancy, which could be informative for FGF21 biology, are seldom. The goal of our study was to examine FGF21 levels in a contemporary healthy, pregnant population.Methods: We phenotyped 43 women with overweight and obesity during pregnancy for weight, body composition, and fasting blood. Serum FGF21 was measured during the first and third trimesters. Placentas were collected at delivery.Results: Maternal FGF21 concentrations were positively correlated with body mass index and adiposity, but not lean mass or glucose homeostasis. FGF21 concentrations significantly increased from the first to third trimester of pregnancy (0.105 vs. 0.256 ng/mL, p < 0.0001). Changes in FGF21 concentrations across pregnancy were not associated with changes in body weight or composition but inversely with the change in fasting glucose. FGF21 mRNA levels in placenta were very low and do not likely contribute to FGF21 in the maternal circulation.Conclusions: FGF21 increases throughout pregnancy in our healthy cohort with overweight and obesity, independent of the placenta, and does not appear to be sensing the changes in energy balance (reflected in the change in maternal energy stores), but changes in macronutrient status. Thus, we propose FGF21 may be a potential signal of maternal nutrient status in pregnancy.

Purinergic Signaling Controls Fibroblast Growth Factor‐21 Expression in Skeletal Muscle through Akt/mTOR Pathway.

Fibroblast Growth Factor‐21 (FGF‐21) is a myokine which induce fiber type transformation and metabolic adaptations in muscle. However, little is known about the molecular mechanisms involved in the regulation of FGF‐21 expression in skeletal muscle in non‐pathological conditions. We have previously described that purinergic signaling is related with muscle adaptations and IL6‐myokine production through the “excitation‐transcription coupling” (ETC) mechanism, in which extracellular ATP (eATP) promotes gene expression in skeletal muscle. We have also demonstrated that eATP activates the PI3K/Akt signaling pathway in myotubes. Considering that Akt has been proposed as a master regulator for FGF‐21 expression control, the aim of this work is to determine the role of extracellular ATP over the FGF‐21 production in adult mouse skeletal muscle, and their dependence on the Akt/mTOR signaling pathway. Mice FDB‐isolated fibers or whole‐muscle were used in this study. The mRNA levels of FGF‐21 after electrical (20 Hz, 270 pulses, 0.3 msec each) or exogenous ATP (100 μM) stimulation were assessed by qPCR. FGF‐21 protein levels were assessed by immunoblot. We used pharmacological inhibitors of purinergic receptors (100 μM Suramin) and Akt/mTOR pathway inhibitors (50 μM LY294002; 1 μM Akt inhibitor VIII; 100 nM rapamycin), to turn off different interactors of the putative signaling pathway. ATP stimulation (100 μM) evoked an 8‐fold increase in FGF‐21 mRNA levels in isolated FDB fibers at 30 min post stimulation. The increase in FGF‐21 mRNA levels evoked by eATP was inhibited by suramin, a general antagonist of P2Y/P2X nucleotide receptors. Electrical stimulation also evokes an increase in FGF‐21 mRNA levels, which was inhibited by both nifedipine (a DHPR blocker) and suramin. Exogenous ATP increased protein levels of FGF‐21 in whole FDB‐muscles at 120 min, in a concentration‐dependent manner, with a maximal increase of 3.5 folds with 3 μM ATP. The increase in FGF‐21 protein level evoked by ATP, was abolished by LY294002 (a PI3K inhibitor), Akt inhibitor VIII, and rapamycin (mTOR inhibitor). In this work, we demonstrated for the first time that extracellular ATP evokes an increase in the mRNA and protein levels of FGF‐21 in skeletal muscle. The increase on FGF‐21 levels evoked by ATP is dependent on Akt/mTOR pathway activation. These results suggest that ETC mechanism could be involved in regulation of FGF‐21 expression in skeletal muscle.Support or Funding InformationFunded by CONICYT PCHA 21151035(MA‐C), 63140009(CM) and Fondecyt 1151353(SB), 1151293(EJ)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A Fibroblast Growth Factor 21–Pregnane X Receptor Pathway Downregulates Hepatic CYP3A4 in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) alters drug response. We previously reported that NAFLD is associated with reduced in vivo CYP3A drug-metabolism activity and hepatic CYP3A4 expression in humans as well as mouse and human hepatoma models of the disease. Here, we investigated the role of the lipid- and glucose-modulating hormone fibroblast growth factor 21 (FGF21) in the molecular mechanism regulating CYP3A4 expression in NAFLD. In human subjects, mouse and cellular NAFLD models with lower CYP3A4 expression, circulating FGF21, or hepatic FGF21 mRNA levels were elevated. Administration of recombinant FGF21 or transient hepatic overexpression of FGF21 resulted in reduced liver CYP3A4 luciferase reporter activity in mice and decreased CYP3A4 mRNA expression and activity in cultured Huh7 hepatoma cells. Blocking canonical FGF21 signaling by pharmacological inhibition of MEK1 kinase in Huh7 cells caused de-repression of CYP3A4 mRNA expression with FGF21 treatment. Mice with high-fat diet-induced simple hepatic steatosis and lipid-loaded Huh7 cells had reduced nuclear localization of the pregnane X receptor (PXR), a key transcriptional regulator of CYP3A4 Furthermore, decreased nuclear PXR was observed in mouse liver and Huh7 cells after FGF21 treatment or FGF21 overexpression. Decreased PXR binding to the CYP3A4 proximal promoter was found in FGF21-treated Huh7 cells. An FGF21-PXR signaling pathway may be involved in decreased hepatic CYP3A4 metabolic activity in NAFLD.

Region-specific effects of developmental exposure to cocaine on fibroblast growth factor-2 expression in the rat brain.

Adolescence is a period of high vulnerability to drugs of abuse and alterations of the proper developmental trajectory via psychostimulant exposure might change the physiological brain homeostasis. By microdissection of brain areas via punching, we investigated whether repeated exposure to cocaine during adolescence (from postnatal day 28 [PND28] to PND42) has altered fibroblast growth factor-2 (FGF-2) messenger RNA (mRNA) levels in selected brain subregions critical for the action of cocaine. We found a reduction of FGF-2 mRNA levels in ventral tegmental area (VTA), where mesocortical and mesolimbic pathways originate. The analysis of the trophic factor levels in the distal projecting regions revealed a selective reduction of FGF-2 mRNA levels in infralimbic (IL) subregion of the medial prefrontal cortex (the terminal region of the mesocortical pathway) and in the nucleus accumbens core (cNAc) (the terminal region of the mesolimbic pathway). Last, we found reduced FGF-2 mRNA levels also in brain regions which, although in a different manner, contribute to the reward system, i.e., the central nucleus of amygdala (cAmy) and the ventral portion of hippocampus (vHip). The widespread and coordinated reduction of FGF-2 mRNA levels across the brain's reward neurocircuitry might represent a defensive strategy set in motion to oppose to the psychostimulant properties of cocaine. Moreover, given the role of FGF-2 in modulating mood disorders, the reduced trophic support here observed might sustain the negative emotional state set in motion by repeated exposure to cocaine.

Mapping the response of human fibroblast growth factor 21 (FGF21) promoter to serum availability and lipoic acid in HepG2 hepatoma cells

The hormone-like polypeptide, fibroblast growth factor 21 (FGF21), is a major modulator of lipid and glucose metabolism and an exploratory treatment strategy for obesity related metabolic disorders. The costs of recombinant FGF21 and mode of delivery by injection are important constraints to its wide therapeutic use. The stimulation of endogenous FGF21 production through diet is being explored as an alternative approach. To that end, we examined the mechanism(s) by which serum manipulation and lipoic acid (a dietary activator of FGF21) induce FGF21 in human hepatocellular carcinoma HepG2 cells. Serum withdrawal markedly induced FGF21 mRNA levels (88 fold) and FGF21 secreted in the media (19 fold). Lipoic acid induced FGF21 mRNA 7 fold above DMSO-treated control cells and FGF21 secretion 3 fold. These effects were several-fold greater than those of PPARα agonist, Wy14643, which failed to induce FGF21 above and beyond the induction seen with serum withdrawal. The use of transcription inhibitor, actinomycin D, revealed that de novo mRNA synthesis drives FGF21 secretion in response to serum starvation. Four previously unrecognized loci in FGF21 promoter were nucleosome depleted and enriched in acetylated histone H3 revealing their role as transcriptional enhancers and putative transcription factor binding sites. FGF21 did not accumulate to a significant degree in induced HepG2 cells, which secreted FGF21 time dependently in media. We conclude that lipoic acid cell signaling connects with the transcriptional upregulation of FGF21 and it may prove to be a safe and affordable means to stimulate FGF21 production.

Abstract B47: Curcumin C3 ® prevents ultraviolet B radiation-induced epidermal damage in JB6 cells and mouse skin via a Fibroblast growth factor-2-dependent manner

Abstract Background and Significance: Non-melanoma skin cancer (NMSC) is the most common skin cancer in the U.S., with over a million new cases anticipated annually. Cutaneous squamous cell carcinoma (SCC) is a more aggressive form of NMSC. Chronic exposure to solar ultraviolet (UVB) is the major etiologic factor causing skin cell damage, photoaging and malignant transformation leading to SCC. UVB is a carcinogen and our previous studies established oral administration of Curcumin C3 complex (C3), a natural occurring polyphenol compound mixture, delayed UVB-induced tumor onset and multiplicity, but not tumor progression. Accordingly, we sort to determine the preventative efficacy of C3® against UVB-induced photodamage using JB6 cells and SKH-1 hairless mouse epidermis on the earlier neoplastic events in the development of UVB-induced skin carcinogenesis. Methods: SKH-1 mice were either administered vehicle or C3 (100mg/kg/b.w) complex orally for 14 days followed by a single exposure to UVB radiation (180mj/cm2). Mice were euthanized 24 hours after UVB exposure and skin tissues and serum were collected. For in vitro studies, promoter–sensitive JB6 mouse epithelial cells were pre-treated with C3® for 2 h and the effects on UV-induced early molecular events were assessed. Results: C3® attenuated UVB-induced epidermal hyperplasia and significantly decreased epidermal and plasma levels of fibroblast growth factor-2 (FGF-2); an important mitogen implicated in proliferation and differentiation of skin keratinocytes. Interestingly, the effects of C3® complex on FGF-2 levels were accompanied with a significant reduction in UVB-induced Nuclear factor KappaB (NF-KB) activation; an important nuclear transcription factor for tumor promotion. Further, the decrease in NF-KB was associated with an inhibition of BCL2 expression to induce apoptosis. In vitro, pretreatment of JB6 cells with C3® significantly decreased UVB-induced proliferation with a corresponding decrease in FGF-2 mRNA and protein levels. Further, C3 complex inhibited NF-KB phosphorylation and increased Bax expression leading to cell apoptosis. Conclusion: Our findings underscore the importance of curcumin (C3) in preventing UVB-induced skin cancer. It provides new insight into curcumin's role through FGF-2 in modulating the pathogenesis of photo carcinogenesis. Citation Format: Alok R. Khandelwal, Arun Anandharaj, Oleksandr Ekshyyan, Lauren D. Saucier, Tara N. Moore-Medlin, Fleurette Abreo, Cherie-Ann O. Nathan. Curcumin C3 ® prevents ultraviolet B radiation-induced epidermal damage in JB6 cells and mouse skin via a Fibroblast growth factor-2-dependent manner. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr B47.

R‐α‐lipoic acid potentiates fasting‐induced transcription and secretion of hepatic fibroblast growth factor 21 (FGF21)

Recombinant FGF21 (rFGF21) is an experimental polypeptide therapy against type‐2 diabetes and lipid anomalies. However, the high costs of producing rFGF21 and the mode of delivery by injection are important limitations to its wide therapeutic use. The stimulation of endogenous FGF21 production through diet is being explored as an alternative approach. Our research showed that naturally occurring dietary organosulfur compound R‐α‐lipoic acid (LA) stimulated liver Fgf21 expression (+175%) and blood FGF21 levels (+330%) and replicated the adaptive metabolic response to fasting evoked by FGF21 in vivo. In the present study, we examined the mechanism(s) by which serum manipulation and LA induce FGF21 in HepG2 human hepatocellular carcinoma cells. Serum starvation markedly induced FGF21 mRNA levels (50 fold) and FGF21 secreted in the media (19 fold). LA induced FGF21 mRNA 7 fold above DMSO‐treated control cells and FGF21 secretion 3 fold. These effects were several‐fold greater than those of PPARα agonist, Wy14643, an inducer of FGF21. The use of transcription inhibitor, actinomycin D, revealed that de novo mRNA synthesis drives FGF21 secretion in response to serum starvation and LA, and FGF21 does not accumulate in HepG2 cells to a significant degree. Previously unrecognized loci of FGF21 distal promoter were nucleosome depleted and transcriptionally active revealing new putative transcription factors. We conclude that LA activates FGF21 distal promoter resulting in FGF21 secretion by liver cells. LA may prove to be a safe and affordable means to stimulate FGF21 production. Supported by UNL ARD Hatch, and Layman Seed Award.

Effects of extremely low frequency electromagnetic fields on human fetal scleral fibroblasts.

This study investigated the effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human fetal scleral fibroblasts (HFSFs). HFSFs were subjected to 50 Hz artificial ELF-EMFs generated by Helmholtz coils with 0.1, 0.2, 0.5, and 1.0 mT field intensities for 6 to 48 h. The viability and factors involved in scleral structuring of HFSFs were determined. The growth rate of HFSFs significantly decreased after only 24 h of exposure to ELF-EMFs (0.2 mT). The messenger RNA (mRNA) expression of collagen type I (COL1A1) decreased and expression of matrix metalloproteinase-2 (MMP-2) increased significantly. There was a decrease in tissue inhibitor of MMP-2 mRNA levels between treated and control cells only at the 1.0 mT intensity level. Transforming growth factor beta-2 mRNA increased in exposed cells, and, simultaneously, fibroblast growth factor-2 mRNA levels decreased. The protein expressions of COL1A1 and MMP-2 were also significantly altered subsequent to exposure (p < 0.05). This study shows that ELF-EMFs had biological effects on HFSFs and could cause abnormality in scleral collagen.

Chromatin-Remodeling Factors Mediate the Balance of Sense-Antisense Transcription at the FGF2 Locus

Antisense transcription is prevalent in mammalian genomes, yet the function of many antisense transcripts remains elusive. We have previously shown that the fibroblast growth factor 2 (FGF2) gene is regulated endogenously by an overlapping antisense gene called Nudix-type motif 6 (NUDT6). However, the molecular mechanisms that determine the balance of FGF2 and NUDT6 transcripts are not yet well understood. Here we demonstrate that there is a strong negative correlation between FGF2 and NUDT6 across 7 different cell lines. Small interfering RNA-mediated knockdown of NUDT6 causes an increase in nascent FGF2 transcripts, including a short FGF2 variant that lacks sequence complementarity with NUDT6, indicating the involvement of transcriptional mechanisms. In support of this, we show that changes in histone acetylation by trichostatin A treatment, histone deacetylase inhibition, or small interfering RNA knockdown of the histone acetyltransferase CSRP2BP, oppositely affect NUDT6 and FGF2 mRNA levels. A significant increase in histone acetylation with trichostatin A treatment was only detected at the genomic region where the 2 genes overlap, suggesting that this may be an important regulatory region for determining the balance of NUDT6 and FGF2. Knockdown of the histone demethylase KDM4A similarly causes a shift in the balance of NUDT6 and FGF2 transcripts. Expression of CSRP2BP and KDM4A correlates positively with NUDT6 expression and negatively with FGF2 expression. The results presented here indicate that histone acetylation and additional chromatin modifiers are important in determining the relative levels of FGF2 and NUDT6 and support a model in which epigenetic remodeling contributes to their relative expression levels.

FGF-21, a novel metabolic regulator, has a robust neuroprotective role and is markedly elevated in neurons by mood stabilizers

Fibroblast growth factor-21 (FGF-21) is a new member of the FGF super-family and an important endogenous regulator of glucose and lipid metabolism. It has been proposed as a therapeutic target for diabetes and obesity. Its function in the central nervous system (CNS) remains unknown. Previous studies from our laboratory demonstrated that aging primary neurons are more vulnerable to glutamate-induced excitotoxicity, and that co-treatment with the mood stabilizers lithium and valproic acid (VPA) induces synergistic neuroprotective effects. This study sought to identify molecule(s) involved in these synergistic effects. We found that FGF-21 mRNA was selectively and dramatically elevated by co-treatment with lithium and VPA in primary rat brain neurons. FGF-21 protein levels were also robustly increased in neuronal lysates and culture medium following lithium-VPA co-treatment. Combining glycogen synthase kinase-3 (GSK-3) inhibitors with VPA or histone deacetylase (HDAC) inhibitors with lithium synergistically increased FGF-21 mRNA levels, supporting that synergistic effects of lithium and VPA are mediated via GSK-3 and HDAC inhibition, respectively. Exogenous FGF-21 protein completely protected aging neurons from glutamate challenge. This neuroprotection was associated with enhanced Akt-1 activation and GSK-3 inhibition. Lithium-VPA co-treatment dramatically prolonged lithium-induced Akt-1 activation and augmented GSK-3 inhibition. Akt-1 knockdown markedly decreased FGF-21 mRNA levels, and reduced the neuroprotection induced by FGF-21 or lithium-VPA co-treatment. In addition, FGF-21 knockdown reduced lithium-VPA co-treatment-induced Akt-1 activation and neuroprotection against excitotoxicity. Together, our novel results suggest that FGF-21 is a key mediator of the effects of these mood stabilizers, and a potential new therapeutic target for CNS disorders.

Effects of fibroblast growth factor-21 gene knockdown on the expression of hepatic gluconeogenesis-related genes and the JAK2/STAT3 signaling pathway in ApoE-/-mice

Objective To investigate the effects of fibroblast growth factor-21 (FGF-21) gene knockdown on the expression of hepatic glyconeogenesis-related genes in ApoE-/-mice and its mechanism.Methods Twenty-four 8-week-old male ApoE-/-mice were randomly divided into chow diet fed group(NC,n =6),chow diet+pAd-shFGF-21group(NF,n=6),high-fat diet fed group(HC,n=6),and high-fat diet+pAd-shFGF-21 group(HF,n=6).Mice were fed for 16 weeks.NC and HC groups injected with pAd-shGFP,however NF and HF groups were injected with pAd-shFGF-21 through the tail vein at the end of the 15th week.At the end of the 16th week,blood samples were collected for measurement of plasma glucose,insulin and lipid levels.Hepatic tissues were collected for measurement of mRNA and protein levels of glyconeogenesis-related genes and JAK2/STAT3 signaling pathway via real-time PCR and Western-blot,respectively.Results The fasting plasma glucose (FBG),fasting plasma insulin (PIns),triglycerides,total cholesterol,and low-density lipoprotein-cholesterol (LDL-C) were significantly higher,while the high-density lipoprotein-cholesterol(HDL-C)was lower in FGF-21-knockdown groups compared with control groups,respectively(P＜0.05 or P＜0.01).When fed with normal and high-fat diet,hepatic FGF-21 mRNA levels were decreased by 76.6％ (P＜0.05) and 40.9％ (P＜0.05) compared with those in control groups,while hepatic FGF-21protein levels were decreased by 67.8％ (P＜0.05) and 49.6％ (P＜0.05),respectively.The hepatic glucose-6-phosphatase(G6pase) and phosphoenolpyruvate carboxykinase (PEPCK)mRNA and protein expression in FGF-21-knockdown groups were significantly increased compared with those in control groups(P＜0.05).At the same time we observed decreased expression of hepatic SOCS3 mRNA and decreased expression of phosphorylated STAT3 and SOCS3 protein in FGF-21 knockdown groups.Conclusions FGF-21 can repress the expression of liver glyconeogenesis-related genes and its mechanism might involve the JAK2/STAT3 signaling pathway. Key words: Fibroblast growth factor-21; Gluconeogenesis; JAK2/STAT3 signaling pathway; Insulin resistance

Effects of thymosin β10 and β15 on wound healing in rat tooth extraction sockets

ObjectiveWe investigated the effects of multifunctional peptides thymosin β10 (TB10) and β15 (TB15) on wound healing in rat tooth extraction sockets. Materials and methodsThe mandibular first molar was extracted, following which a synthetic partial TB10 or TB15 peptide was administered intraperitoneally. Phosphate-buffered saline (PBS) was intraperitoneally administered as a control. Histological and immunohistochemical analyses were performed on the tooth extraction sockets. Granulation tissue was also obtained from the tooth extraction sockets, and transforming growth factor-β1 (TGF-β1), fibroblast growth factor-2 (FGF-2), bone morphogenetic protein 2 (BMP2), and bone morphogenetic protein 7 (BMP7) gene expression levels were determined by reverse transcriptase-polymerase chain reaction (RT-PCR). ResultsEnhanced granulation tissue formation was observed in the tooth extraction sockets of both TB10- and TB15-administered rats compared with PBS-administered controls. In addition, the number of osterix-positive cells in the TB15 group was significantly increased in the tooth extraction sockets. TB10 promoted fibrosis, whereas TB15 enhanced osteogenesis. In the tooth extraction sockets, TB10 induced an increase in TGF-β1 and FGF-2 mRNA levels, whereas TB15 induced an increase in BMP2 and BMP7 mRNA levels. ConclusionThese results suggest that TB10 and TB15 have different effects on wound healing after tooth extraction.