Growth Differentiation Factor 15 Overexpression Research Articles

NR2F1 overexpression alleviates trophoblast cell dysfunction by inhibiting GDF15/MAPK axis in preeclampsia.

Abnormal functions of trophoblast cells are associated with the pathogenesis of preeclampsia (PE). Nuclear receptor subfamily 2 group F member 1 (NR2F1) acts as a transcriptionally regulator in many diseases, but its role in PE remains unknown. Hypoxia/reoxygenation (H/R)-stimulated HTR-8/SVneo cells were used to mimic PE injury in vitro. NR2F1 overexpression alleviated trophoblast apoptosis, as evidenced by the decreased number of TUNEL-positive cells and the downregulation of caspase 3 and caspase 9 expression in cells. NR2F1 overexpression increased the invasion and migration ability of HTR-8/SVneo cells, accompanied by increased protein levels of matrix metalloproteinase (MMP)-2 and MMP-9. mRNA-seq was applied to explore the underlying mechanism of NR2F1, identifying growth differentiation factor 15 (GDF15) as the possible downstream effector. Dual-luciferase reporter, ChIP-qPCR, and DNA pull-down assays confirmed that NR2F1 bound to the promoter of GDF15 and transcriptionally inhibited its expression. GDF15 overexpression increased apoptosis and decreased the ability of invasion and migration in HTR-8/SVneo cells expressing NR2F1. MAPK pathway was involved in the regulation of PE. Administration of p38 inhibitor, ERK inhibitor, and JNK inhibitor reversed the effect of simultaneous overexpression NR2F1 and GDF15 on trophoblast apoptosis, invasion, and migration. Our findings demonstrated that NR2F1 overexpression inhibited trophoblast apoptosis and promoted trophoblast invasion and migration. NR2F1 might negatively regulate GDF15 expression by binding to its promoter region, which further inhibited MAPK signaling pathway in PE. Our study highlights that NR2F1 might sever as a potential target in PE.

Knockdown of growth differentiation factor-15 restrains prostate cancer through regulating MAPK/ERK signaling pathway.

Prostate cancer, prevalent among males, is influenced by various molecular factors, including Growth Differentiation Factor 15 (GDF15). Despite its recognized role in multiple tumor types, GDF15's specific involvement in prostate cancer remains insufficiently explored. This study investigates the regulatory function of GDF15 in prostate cancer. To explore GDF15's impact, we established GDF15 knockdown and overexpression models in prostate cancer cells. We quantified mRNA and protein levels using RT-PCR and Western blotting. Functional assays, including CCK8, Transwell, wound healing, and flow cytometry, were employed to evaluate cell proliferation, invasion, migration, and apoptosis. Additionally, the effect of GDF15 on tumor growth was assessed using a metastatic tumor model in nude mice. Elevated GDF15 expression was identified in prostate cancer tissues and cells. The knockdown of GDF15 led to the activation of the MAPK/ERK signaling pathway. C16PAF was found to counteract the inhibitory effects of sh-GDF15 on cell proliferation, invasion, migration, and apoptosis in LNCaP cells. It also reversed the sh-GDF15-induced alterations in the epithelial-mesenchymal transition (EMT) process. In vivo, C16PAF notably mitigated the sh-GDF15-induced suppression of tumor growth. The study demonstrated that sh-GDF15 inhibits cell proliferation, invasion, migration, EMT process, and tumor growth, while it promotes apoptosis. However, these effects were significantly reversed by C16PAF. The study underscores the potential of GDF15 as a target for novel therapeutic interventions in prostate cancer treatment and prevention. These findings illuminate GDF15's multifaceted role in prostate cancer pathogenesis and suggest its viability as a therapeutic target.

GDF15 plays a critical role in insulin secretion in INS-1 cells and human pancreatic islets.

Mounting evidence points to a link between growth differentiation factor-15 (GDF15) expression and the onset and progression of diabetes mellitus. However, the exact role of GDF15 in pancreatic β-cell function is unclear. To examine the role of GDF15 in β-cell function, bioinformatics analysis and functional experiments involving GDF15 silencing and overexpression were performed in INS-1 cells and human islets. Public microarray and RNA-seq expression data showed that islets obtained from diabetic donors express high levels of GDF15 compared to islets obtained from normal donors. Moreover, analysis of RNA-seq expression data revealed that GDF15 expression correlates positively with that of insulin (INS), KCNJ11, GLUT1, MAFA, INSR and negatively with that of Glucokinase (GCK) and Alpha-Ketoglutarate Dependent Dioxygenase (FTO). No T2D-associated genetic variants in the GDF15 were found to pass genome-wide significance in the TIGER portal. Expression silencing of Gdf15 in INS-1 cells reduced insulin release, glucose uptake levels, increased reactive oxygen species (ROS) production and apoptosis levels. While Gdf15-silenced cells downregulated mRNA expression of Ins, Pdx1, Mafa, and Glut2 genes, its overexpression human islets was associated with increased insulin secretion and upregulated expression of MAFA and GLUT1 but not INS or GCK. Silencing of Pdx1 or Mafa in INS-1 cells did not affect the expression of GDF15. These findings suggest that GDF15 plays a significant role in pancreatic β-cell function.

GDF15 Ameliorates Liver Fibrosis by Metabolic Reprogramming of Macrophages to Acquire Anti-Inflammatory Properties

Liver fibrosis/cirrhosis is significant health burden worldwide, resulting in liver failure or cancer and accounting for many deaths each year. The pathogenesis of liver fibrosis is very complex, which makes treatment challenging. Growth differentiation factor 15 (GDF15), a cysteine knot protein belonging to the transforming growth factor β (TGF-β) superfamily, has been shown to play a protective role after tissue injury and to promote a negative energy balance during obesity and diabetes. However, paucity of literature is available about GDF15 function in liver fibrosis. This study aimed to investigate the immunomodulatory role and therapeutic potential of GDF15 in progression of hepatic fibrosis. GDF15 expression was studied in patients with fibrosis/cirrhosis and in 2 murine models of liver fibrosis, including mice treated with CCl4 or DDC diet. GDF15 involvement in the pathogenesis of liver fibrosis was assessed in Gdf15 knockout mouse using both CCl4 and DDC diet experimental models. We used the CCl4 and/or DDC diet-induced liver fibrosis model to examine the antifibrotic and anti-inflammatory effects of AAV8-mediated GDF15 overexpression in hepatocytes or recombinant mouse GDF15. GDF15 expression is decreased in the liver of animal models and patients with liver fibrosis/cirrhosis compared with those without liver disease. Invivo studies showed that GDF15 deficiency aggravated CCl4 and DDC diet-induced liver fibrosis, while GDF15 overexpression mediated by AAV8 or its recombinant protein alleviated CCl4 and/or DDC diet-induced liver fibrosis. In Gdf15 knockout mice, the intrahepatic microenvironment that developed during fibrosis showed relatively more inflammation, as demonstrated by enhanced infiltration of monocytes and neutrophils and increased expression of proinflammatory factors, which could be diminished by AAV8-mediated GDF15 overexpression in hepatocytes. Intriguingly, GDF15 exerts its effects by metabolic reprogramming macrophages to acquire an oxidative phosphorylation-dependent anti-inflammatory functional fate. Furthermore, adoptive transfer of GDF15-preprogrammed macrophages to mouse models of liver fibrosis induced by CCl4 attenuated inflammation and alleviated the progression of liver fibrosis. GDF15 ameliorates liver fibrosis via modulation of liver macrophages. Our data implicate the importance of the liver microenvironment in macrophage programming during liver fibrosis and suggest GDF15 that is a potentially attractive therapeutic target for the treatment of patients with liver fibrosis.

"GDF-15 Signaling Leading to Epithelial-to-Mesenchymal Transition in Colorectal Cancer - a Literature Review"

"Abstract Importance: The epithelial-mesenchymal transition (EMT) is a well-established process leading to metastasis, which is responsible for the majority of cancer-related deaths. EMT represents a critical step in the development of tumors, and is distinguishable through specific characteristics in tumor cells, such as the ability to invade and resist pharmacological treatments. Growth differentiation factor 15 (GDF-15) is a distinct member of the transforming growth factor β (TGF- β) superfamily which increases metastasis of cells both in vitro and in vivo by inducing EMT. Observations: High GDF-15 levels in certain cancers, including endometrial, prostate, pan-creatic, and colorectal cancer (CRC), may be associated with poor clinical outcomes. Higher plasma concentrations of GDF-15 have been linked to an increased risk of developing CRC and colorectal CRC-related mortality prior to a diagnosis of CRC. It has been observed that surgical excision of CRC reduces serum GDF-15, which increases when the tumor progresses, and that monitoring serum levels after surgery may aid in the prediction of cancer recurrence. However, data showed that GDF-15 regulation promoted 5-Fluorouracil (5-FU) resistance in colon cancer and GDF-15 overexpression can re-sensitize 5-FU-resistant tumor cells to chemotherapy, sug-gesting that GDF-15 may function as a tumor suppressor gene in colon cancer. Conclusions: Functional investigations of GDF-15's role in malignancy are scarce and dis-puted; prior findings indicate overexpression of GDF-15 in cancers, which contrasts GDF-15's potential role as a tumor suppressor. A thorough understanding of the regulatory mechanisms of EMT may lead to significant advancements in the treatment and prevention of cancer. Keywords: growth/differentiation factor-15, GDF-15, epithelial–mesenchymal transition, EMT, colorectal cancer, metastasis, prognostic."

Growth Differentiation Factor 15 Protects SH-SY5Y Cells From Rotenone-Induced Toxicity by Suppressing Mitochondrial Apoptosis.

ObjectiveParkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide. Mitochondrial dysfunction is suspected as one of the pathogenic mechanisms of PD. Growth/differentiation Factor-15 (GDF15) has been reported to affect mitochondrial function in PD. However, the relationship between mitochondrial function and GDF15 induction has not been explained well. Hence, we aimed to reveal the effect of GDF15 induction on SH-SY5Y cells with rotenone toxicity, a cell model of PD.MethodsSH-SY5Y cells were exposed to 1 μM rotenone as a PD model. Cells were transfected with a GDF15-overexpression plasmid and empty vector. We then analyzed the expression level of GDF15, BCL-2/BAX, P53, PGC1-α, α-syn, and TH in GDF15-overexpressing cells by western blotting, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction. The cytotoxicity of rotenone was measured by CCK-8 assays. Cell apoptosis was detected by flow cytometric and TUNEL assays. The effect of GDF15 on oxidative stress and mitochondrial function was revealed using DCFH-DA, mito-SOX, and JC-10 assays and a Seahorse XF Cell Mito Stress Test.ResultsGDF15 protected rotenone-treated SH-SY5Y cells from toxicity by preserving mitochondrial function and decreasing apoptosis, during which GDF15 might function by influencing PGC1α through the regulation of p53. In addition, GDF15 overexpression could improve Akt and mTOR phosphorylation, leading to PI3K/Akt/mTOR pathway activation. However, these protective effects were eliminated when cells were treated with the PI3K/Akt specific inhibitor LY294002.ConclusionOur findings suggest that GDF15 can protect mitochondrial function and inhibit apoptosis in SH-SY5Y cells after exposure to rotenone by upregulating PGC1α via p53. These properties might comprise its anti-apoptotic effects, mediated by the PI3K/Akt/mTOR signaling pathway.

Overexpression of NAG-1/GDF15 prevents hepatic steatosis through inhibiting oxidative stress-mediated dsDNA release and AIM2 inflammasome activation

Mitochondrial dysfunction and oxidative stress-mediated inflammasome activation play critical roles in the pathogenesis of the non-alcoholic fatty liver disease (NAFLD). Non-steroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1), or growth differentiation factor-15 (GDF15), is associated with many biological processes and diseases, including NAFLD. However, the role of NAG-1/GDF15 in regulating oxidative stress and whether this process is associated with absent in melanoma 2 (AIM2) inflammasome activation in NAFLD are unknown. In this study, we revealed that NAG-1/GDF15 is significantly downregulated in liver tissues of patients with steatosis compared to normal livers using the Gene Expression Omnibus (GEO) database, and in free fatty acids (FFA, oleic acid/palmitic acid, 2:1)-induced HepG2 and Huh-7 cellular steatosis models. Overexpression of NAG-1/GDF15 in transgenic (Tg) mice significantly alleviated HFD-induced obesity and hepatic steatosis, improved lipid homeostasis, enhanced fatty acid β-oxidation and lipolysis, inhibited fatty acid synthesis and uptake, and inhibited AIM2 inflammasome activation and the secretion of IL-18 and IL-1β, as compared to their wild-type (WT) littermates without reducing food intake. Furthermore, NAG-1/GDF15 overexpression attenuated FFA-induced triglyceride (TG) accumulation, lipid metabolism deregulation, and AIM2 inflammasome activation in hepatic steatotic cells, while knockdown of NAG-1/GDF15 demonstrated opposite effects. Moreover, NAG-1/GDF15 overexpression inhibited HFD- and FFA-induced oxidative stress and mitochondrial damage which in turn reduced double-strand DNA (dsDNA) release into the cytosol, while NAG-1/GDF15 siRNA showed opposite effects. The reduced ROS production and dsDNA release may be responsible for attenuated AIM2 activation by NAG-1/GDF15 upon fatty acid overload. In conclusion, our results provide evidence that other than regulating lipid homeostasis, NAG-1/GDF15 protects against hepatic steatosis through a novel mechanism via suppressing oxidative stress, mitochondrial damage, dsDNA release, and AIM2 inflammasome activation.

Growth differentiation factor-15 preserves Klotho expression in acute kidney injury and kidney fibrosis

Growth differentiation factor-15 (GDF15) is a member of the GDF subfamily with potential kidney protective functions. Here, we explored the impact of GDF15 on the expression of the kidney protective factor Klotho in models of acute kidney injury and kidney fibrosis in mice. GDF15 was the most upregulated GDF family gene in experimental toxic acute kidney injury and in kidney fibrosis transcriptomics. GDF15 function was explored in toxic acute kidney injury in genetically modified mice and following treatment with GDF15. Gdf15-deficient mice developed more severe toxic acute kidney injury (folic acid or cisplatin) while GDF15 overexpression or GDF15 administration were protective. Kidney expression of Klotho was more severely depressed in Gdf15-deficient mice and was preserved by GDF15 overexpression or GDF15 treatment. Moreover, increased plasma calcitriol levels inversely correlated with kidney Klotho across models with diverse levels of GDF15 availability. Kidney fibrosis induced by unilateral ureteral obstruction was more severe in Gdf15-deficient mice while GDF15 overexpression decreased kidney injury and preserved Klotho expression. GDF15 increased Klotho expression invivo in healthy mice, in cultured tubular cells, and prevented Klotho downregulation by inflammatory factors in tubular cells by preventing transcription factor NF-ĸB activation. Thus, spontaneous increased kidney expression of endogenous GDF15 is not enough to prevent kidney injury, but further increments in GDF15 are kidney protecting and preserve expression of the kidney protective factor Klotho within the kidney in acute and chronic settings.

Mechanism of sensitivity to cisplatin, docetaxel, and 5-fluorouracil chemoagents and potential erbB2 alternatives in oral cancer with growth differentiation factor 15 overexpression.

The aim of this study was to: (a) explore the potential mechanism of cancer cell sensitivity to cisplatin, docetaxel, and 5‐fluorouracil (TPF) in oral squamous cell carcinoma (OSCC) patients overexpressing growth differentiation factor 15 (GDF15); and (b) identify potential alternative agents for patients who might not benefit from inductive TPF chemotherapy. The results indicated that OSCC cells overexpressing GDF15 were sensitive to TPF through a caspase‐9‐dependent pathway both in vitro and in vivo. Immunoprecipitation combined with mass spectrometry revealed that the erbB2 protein was a potential GDF15‐binding protein, which was verified by coimmunoprecipitation. Growth differentiation factor 15 overexpression promoted OSCC cell proliferation through erbB2 phosphorylation, as well as downstream AKT and Erk signaling pathways. When GDF15 expression was blocked, the phosphorylation of both the erbB2 and AKT/Erk pathways was downregulated. When OSCC cells with GDF15 overexpression were treated with the erbB2 phosphorylation inhibitor, CI‐1033, cell proliferation and xenograft growth colony formation were significantly blocked (P < .05). Thus, GDF15‐overexpressing OSCC tumors are sensitive to TPF chemoagents through caspase‐9‐dependent pathways. Growth differentiation factor 15 overexpression promotes OSCC proliferation through erbB2 phosphorylation. Thus, ErbB2 inhibitors could represent potential targeted drugs or an alternative therapy for OSCC patients with GDF15 overexpression.

Metformin alleviates bevacizumab-induced vascular endothelial injury by up-regulating GDF15 and activating the PI3K/AKT/FOXO/PPARγ signaling pathway.

BackgroundPrevious studies have reported that the combination of metformin and bevacizumab exhibit favorable efficacy in the treatment of cancer patients, and metformin possesses effects on relieving vascular injury in multiple diseases. Nonetheless, the effect of metformin in alleviating bevacizumab-induced vascular injury remains unknown. Therefore, the present study aimed to investigate the impact of metformin on apoptosis, vascular endothelial injury marker expressions, and inflammation in human umbilical vein endothelial cells (HUVECs), as well as its possible molecular mechanism.MethodsHUVECs were treated with bevacizumab, metformin or both, and subsequently treated with growth differentiation factor 15 (GDF15) overexpression plasmid, negative control (NC) plasmid, GDF15 small interfering ribonucleic acid (siRNA), NC siRNA, and the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, respectively. After treatment, apoptosis, levels of endothelial injury biomarkers and the potential downstream proteins were detected.ResultsBevacizumab increased the levels of apoptosis, vascular endothelial injury marker expressions and pro-inflammatory cytokine expressions in HUVECs, while metformin alleviated these effects in bevacizumab-treated HUVECs. Furthermore, GDF15 overexpression reduced the apoptosis, vascular endothelial injury marker expressions, pro-inflammatory cytokine expressions, and activated the PI3K/protein kinase B (AKT)/forkhead box O (FOXO)/peroxisome proliferator-activated receptor γ (PPARγ) signaling pathway in bevacizumab-treated HUVECs. Subsequently, GDF15 siRNA reduced the effects of metformin on the bevacizumab-induced vascular endothelial injury (as described above) in HUEVCs. Lastly, the PI3K inhibitor exhibited similar effects to those of GDF15 siRNA in bevacizumab-treated HUVECs.ConclusionsMetformin protected against bevacizumab-induced vascular endothelial injury via activation of GDF15 and the PI3K/AKT/FOXO/PPARγ signaling pathway.

Overexpression of Growth Differentiation Factor 15 Reduces Blood Pressure and Produces Anti‐neuroinflammatory Effects in Mice with Diet‐induced Obesity

The growth differentiation factor 15 (GDF15) is a stress-responsive cytokine, which belongs to the super family of transforming growth factor beta (TGFb). In the past decade, GDF15 has been implicated in multiple biological processes and diseases, including anti-inflammation, anti-obesity and anti-diabetes effects. However, the role of GDF15 in sympathetic regulation of blood pressure has not been reported in the cardiovascular disease state. The purpose of the study was to investigate the effects of GDF15 on the blood pressure and central nervous system neuroinflammatory responses in diet-induced obese mice. NAG-Tg+ transgenic mice (TG) with overexpression of GDF15 and wild-type (WT) littermates were fed on normal chow or high-fat diet (HFD) for 16 weeks. During the experimental period, arterial pressure was recorded by radiotelemetry in conscious mice. WT mice with HFD had higher mean arterial pressure (MAP) compared with the normal diet fed WT mice (WT HFD 110±4 mmHg verse WT 93±4 mmHg). Compared with WT mice with HFD, GDF15 overexpression significantly reduced MAP (TG HFD: 99±3 mmHg verse WT HFD: 110±4 mmHg) accompanied by the decreased urinary norepinephrine excretion and baseline renal sympathetic nerve activity (TG HFD: 38.9±4.1% max verse WT HFD: 61.2±5.6% max). GDF15 TG mice with HFD had lower expressions of pro-inflammatory cytokines interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-a), interleukin 1β (IL-1β), C1q/TNF-related protein-1 (CTRP1) and reduced immune cell infiltration in the hypothalamus and brain stem tissue. A downregulation in GDF15 receptor (GFRAL) expression was detected in brain stem medullary nuclei in WT HFD mice, which was significantly upregulated in GDF15 TG mice with HFD. These data suggest that GDF15 overexpression exerts a potential protective effect on hypertension in obese mice through attenuating sympathetic outflow. The mechanism for this effect involves anti-inflammatory and neuronal protective properties of GDF15 in the central nervous system.

GDF15 Repression Contributes to 5-Fluorouracil Resistance in Human Colon Cancer by Regulating Epithelial-Mesenchymal Transition and Apoptosis.

Chemotherapy based on 5-fluorouracil (5-FU) is the standard approach for colon cancer treatment, and resistance to 5-FU is a significant obstacle in the clinical treatment of colon cancer. However, the mechanisms underlying 5-FU resistance in colon cancer cells remain largely unknown. This study aimed at determining whether 5-FU-resistant colon cancer cells undergo epithelial-mesenchymal transition (EMT) and apoptosis and the role of GDF15—a member of the transforming growth factor β/bone morphogenetic protein super family and a protein known to be involved in cancer progression—in the regulation of EMT and apoptosis of these cells, along with the underlying mechanisms. In vitro apoptosis detection assay, growth inhibition assay, transwell, and wound healing experiments revealed that 5-FU-resistant colon cancer cells possessed enhanced EMT and antiapoptotic ability. These cells also showed a stronger tendency to proliferate and metastasize in vivo. Quantitative reverse transcription-PCR and western blotting revealed that 5-FU-resistant colon cancer cells expressed lower levels of growth differentiation factor 15 (GDF15) than did 5-FU-sensitive colon cancer cells. Moreover, the transient GDF15 overexpression resensitized 5-FU-resistant colon cells to 5-FU. Collectively, these findings indicate the mechanism underlying the 5-FU resistance of colon cancer cells and provide new therapeutic targets for improving the prognosis of colon cancer patients.

Growth differentiation factor-15 slows the growth of murine prostate cancer by stimulating tumor immunity.

Growth Differentiation Factor-15 (GDF15) is a divergent TGF-beta superfamily cytokine that is overexpressed by most cancers and is induced by anticancer therapy. Transgenic and induced animal models suggest that it protects from cancer development but the mechanisms are uncertain. We investigated the role of immunity in GDF15 induced reduction in prostate cancer (PCa) growth. The C57BL/6 transgenic TRAMP prostate cancer prone mice were bred with mice that were immunodeficient and/or systemically overexpressed GDF15. We developed a novel orthotopic TRAMP PCa model in which primary TRAMP tumor cells were implanted into prostates of mice to reduce the study time. These mice were administered recombinant mouse GDF15, antibody to CD8, PD1 or their respective controls. We found that GDF15 induced protection from tumor growth was reversed by lack of adaptive immunity. Flow cytometric evaluation of lymphocytes within these orthotopic tumors showed that GDF15 overexpression was associated with increased CD8 T cell numbers and an increased number and proportion of recently activated CD8+CD11c+ T cells and a reduced proportion of "exhausted" CD8+PD1+ T cells. Further, depletion of CD8 T cells in tumor bearing mice abolished the GDF15 induced protection from tumor growth. Infusion of GDF15 into mice bearing orthotopic TRAMP tumor, substantially reduced tumor growth that was further reduced by concurrent PD1 antibody administration. GDF15 overexpression or recombinant protein protects from TRAMP tumor growth by modulating CD8 T cell mediated antitumor immunity and augments the positive effects of anti-PD1 blockers.

Mechanism of sensitivity to TPF chemoagents and its potential alternative of erbB2 in oral cancer with GDF15 overexpression.

e18542 Background: To explore the mechanism of sensitivity to docetaxel, cisplatin, and 5-fluorouracil (TPF) chemoagents in patients with oral squamous cell carcinoma (OSCC) and growth differentiation factor 15 (GDF15) overexpression recruited in a TPF induction chemotherapy trial; and to explore potential alternative agents for patients who might not benefit from TPF induction chemotherapy. Methods: GDF15-overexpression and silenced OSCC cells were used to investigate sensitivity to TPF chemoagents in vitro and in vivo. Immunoprecipitation combined with mass spectrometry was used to screen out the possible receptor for GDF15, and associated signaling pathways were detected after intervention with the possible receptor of GDF15. The efficacy of an inhibitor of the phosphorylation of the possible GDF15 receptor was evaluated by treatment of GDF15-overexpression OSCC cells in vitro and in vivo. Results: Overexpression of GDF15 in OSCC cell lines and xenografts lead to an increase of chemotherapeutics sensitivity on apoptosis effects induced by docetaxel, cisplatin and 5-fluorouracil, through a caspase -dependent pathway. Immunoprecipitation combined with mass spectrometry revealed that the erbB2 protein was a potential binding protein of GDF15, as verified by coimmunoprecipitation. When GDF15 was overexpressed, the phosphorylation of erbB2 and downstream PI3K/AKT and MAPK/ERK pathways was significantly upregulated, but was downregulated when GDF15 expression was interfered. The erbB2 phosphorylation inhibitor CI1033 significantly inhibited the proliferation and colony-forming ability of GDF15-overexpression OSCC cells as well as the growth of xenografts. CI1033 might be used as a potential targeted drug or alternative of TPF chemoagents for OSCC patients with GDF15 overexpression. Conclusions: OSCC with GDF15 overexpression exhibit sensitivity to TPF chemoagents through a caspase-dependent pathway. ErbB2 phosphorylation inhibitors might be used as potential targeted drugs or an alternative of TPF chemoagents for OSCC patients with GDF15 overexpression.

Downregulated Long Noncoding RNA GAS5 Fails to Function as Decoy of CEBPB, Resulting in Increased GDF15 Expression and Rapid Ovarian Cancer Cell Proliferation.

Introduction: Growth differentiation factor 15 (GDF15), a newly identified member of transforming growth factor (GDF) superfamily, is upregulated in ovarian (OV) cancer. Upregulated GDF15 positively correlates with poor prognosis of OV cancer. Thus, elucidation of the mechanism underlying GDF15 overexpression is important. Method and Results: PROMO and JASPAR prediction software were used to find transcription factors for GDF15 expression. Data from TCGA database were analyzed to find long noncoding RNAs (lncRNAs) that were also abnormally expressed in OV cancer and had associations with GDF15 expression. Transcription factor CEBPB was predicted as an important regulator of GDF15, confirmed by luciferase reporter assay. However, CEBPB expression was not significantly changed in OV cancer. Data from TCGA database showed that lncRNA GAS5 is downregulated in OV cancer and its expression is negatively correlated with GDF15 expression. RPISeq showed high affinity of GAS5 to CEBPB and this was confirmed by RNA-binding protein immunoprecipitation assay. GAS5 overexpression increased its binding to CEBPB and consequently downregulated GDF15. GAS5 overexpression and GDF15 knockdown decreased viability and increased apoptosis of OV cancer cells, but CEBPB overexpression had opposite effects. However, simultaneous GAS5 and CEBPB overexpression or CEBPB overexpression together with GDF15 knockdown had no effect on cell viability and apoptosis. Conclusion: GAS5 functions as decoy of CEBPB, blocking transcription-promoting effect of CEBPB on GDF15.

GDF-15 promotes mitochondrial function and proliferation in neuronal HT22 cells.

The neuronal cell line HT22 is an excellent model for studying Parkinson's disease. Growth differentiation factor 15 (GDF15) plays a critical role in Parkinson's disease, but the molecular mechanism involved are not well understood. We constructed the GDF15 overexpression HT22 cells and detected the effects of overexpression of GDF15 on the viability, oxygen consumption, mitochondrial membrane potential of oligomycin-treated HT22 cells. In addition, we used a high-throughput RNA-sequencing to study the lncRNA and mRNA expression profiling and obtained key lncRNAs, mRNA, gene ontology (GO), and Kyoto encyclopedia of genes and genomes (KEGG) pathway. The expression of selected DElncRNAs was validated by quantitative real-time PCR (qRT-PCR). Our results showed that overexpression of GDF15 significantly reversed the cells viability, oxygen consumption, and mitochondrial membrane potential effect caused by oligomycin in HT22 cells. The 1093 DEmRNAs and 395 DElncRNAs in HT22 cells between GDF15-oligomycin non-intervention group and a normal control-oligomycin un-intervention group were obtained, and 394 DEmRNAs and 271 DElncRNAs in HT22 cells between GDF15-oligomycin intervention group and normal control-oligomycin intervention group were identified. Base on the GO and KEGG enrichment analysis of between GDF15-oligomycin intervention group and normal control-oligomycin intervention group, positive regulation of cell proliferation was most significantly enriched GO terms, and Cav1 was enriched in positive regulation of cell proliferation pathway. PI3K-Akt signaling pathway was one significantly enriched pathway in GDF15-oligomycin intervention group. The qRT-PCR results were consistent with RNA-sequencing, generally. GDF15 might promote mitochondrial function and proliferation of HT22 cells by regulating PI3K/Akt signaling pathway. Our study may be helpful in understanding the potential molecular mechanism of GDF15 in Parkinson's disease.

Growth Differentiation Factor 15 Ameliorates Nonalcoholic Steatohepatitis Associated with Metabolic Syndrome in Mice

Growth differentiation factor 15 (GDF15) is an endocrine hormone belonging TGFβ superfamily member. GDF15 administration or GDF15 overexpression has been reported to have anti-obesity and antidiabetic effects. Although nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is frequently associated with metabolic syndrome or diabetes, the functional role of endogenous GDF15 and therapeutic effect of exogenous GDF15 in NASH associated metabolic syndrome have not been addressed. We studied whether GDF15 has therapeutic effects on NASH and associated metabolic syndrome. To this end, Gdf15-knockout and Gdf15-transgenic mice were employed, and mice were fed Amylin liver NASH (AMLN) diet as a physiologically relevant dietary mouse model of NASH associated with metabolic syndrome. GDF15 expression was increased in the livers of mice fed AMLN diet and human subjects with NASH. Elevated expression of GDF15 was due to diet-induced endoplasmic reticulum (ER) stress in the liver. Importantly, Gdf15-knockout mice exhibited deteriorated metabolic syndrome and aggravated NASH phenotypes such as increased steatosis, hepatic inflammation, fibrosis and liver injury. Furthermore, we found that GDF15 directly suppresses expression of fibrosis-related genes and osteopontin (OPN) in the liver in vivo. OPN expression was increased in hepatocytes and stellate cells in the liver of Gdf15-knockout mice. Finally, we found that GDF15-transgenic mice showed attenuated NASH phenotypes and improved glucose tolerance in mice fed AMLN diet. Our results suggest that induction of endogenous GDF15 is a compensatory mechanism to protect against NASH associated with metabolic syndrome and that GDF15 could be an attractive therapeutic candidate for treatment of these diseases. Disclosure M. Lee: Other Relationship; Self; Jeil Pharmaceutical Co. Ltd.. Y. Lee: None. S. Kim: None. K. Kim: None.

GDF15 Is Induced by T1D-Associated Cytokines and ER Stress and Promotes Beta-Cell Apoptosis

Type 1 diabetes (T1D) is characterized by T-cell and cytokine-mediated pancreatic beta cell loss, but some of the mechanisms involved are still unknown. Growth differentiation factor 15 (GDF15), which is a distant member of the transforming growth factor β (TGFβ) family, has been shown to be increased in various diseases including cancer, heart failure and type 2 diabetes and to promote cancer cell apoptosis. Although we found that GDF15 is highly expressed in adult human beta cells, its role in beta cells and T1D has not been studied. In the present study, we found that GDF15 is significantly elevated in the islets of diabetic female NOD mice compared to nondiabetic female NOR and male NOD mice. In addition, by using human islets, Akita beta cells and INS-1 beta cells, we found that the expression and content of GDF15 are significantly increased by T1D-associated cytokines and thapsigargin/ER stress. Furthermore, we demonstrated that GDF15 knockdown significantly blunts cytokines-induced beta cell apoptosis, while GDF15 overexpression exacerbates T1D-associated cytokines-induced beta cell apoptosis. Taken together, these findings suggest that GDF15 is induced by cytokine-induced ER-stress in beta cells and might contribute to the beta cell loss in T1D. Targeting beta cell GDF15 may therefore represent a novel strategy to inhibit beta cell loss in T1D. Disclosure G. Xu: None. L. Thielen: None. J. Chen: None. S. Jo: None. A. Shalev: None.

GDF15 promotes epithelial-to-mesenchymal transition in colorectal

Growth differentiation factor 15 (GDF15) is a divergent member of the transforming growth factor-β (TGF-β) superfamily that has been associated with colorectal cancers (CRC). However, the role of GDF15 in the progression of CRC remains unknown. We demonstrated that GDF15 expression was higher in fresh CRC tissues than in adjacent normal tissues. Moreover, we found that GDF15 overexpression significantly facilitated cell viability, cell invasion and migration (p < .01 or p < .05). The protein expression of N-cadherin, vimentin and Twist1 were up-regulated by GDF15 overexpression, while E-cadherin was down-regulated. Reciprocally, using a GDF15-shRNA strategy, we observed that GDF15 downregulation inhibited both basal and GDF16-induced cell viability, invasion and migration in LoVo cells. In conclusion, GDF15 could promote cell viability, invasion and migration of LoVo cells through EMT induction.

Growth differentiation factor 15 ameliorates nonalcoholic steatohepatitis and related metabolic disorders in mice

Growth differentiation factor 15 (GDF15) is an endocrine hormone belonging to the TGFβ superfamily member. GDF15 administration or GDF15 overexpression has been reported to have anti-obesity and anti-diabetic effects. Although non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) is frequently associated with obesity and insulin resistance, the functional role of endogenous GDF15 and therapeutic effect of GDF15 overexpression in NASH and related metabolic deterioration have not been evaluated. Here, we found that GDF15 expression was increased in the livers of NASH animal models and human subjects with NASH. Elevated expression of GDF15 was due to diet-induced hepatic endoplasmic reticulum (ER) stress. Gdf15-knockout mice exhibited aggravated NASH phenotypes such as increased steatosis, hepatic inflammation, fibrosis, liver injury, and metabolic deterioration. Furthermore, GDF15 directly suppressed expression of fibrosis-related genes and osteopontin (OPN), contributing factors for NASH-related fibrosis, in hepatic stellate cells in vitro and in the liver of mice in vivo. Finally, we found that GDF15-transgenic mice showed attenuation of NASH phenotypes and metabolic deterioration. Therefore, our results suggest that induction of endogenous GDF15 is a compensatory mechanism to protect against the progression of NASH and that GDF15 could be an attractive therapeutic candidate for treatment of NASH and NASH-related metabolic deterioration.