Growth Differentiation Factor 15 mRNA Research Articles

Growth differentiation factor 15 predicts advanced fibrosis in biopsy-proven non-alcoholic fatty liver disease.

We explored whether growth differentiation factor 15 (GDF15) affects the histological severity of non-alcoholic fatty liver disease (NAFLD) independent of insulin resistance. In a biopsy-proven NAFLD cohort, we measured serum GDF15 levels using enzyme-linked immunosorbent assays. Among 190 subjects (mean age, 53±14years; men, 52.1%), 72 (men, 65.3%) and 78 (men, 44.9%) were diagnosed with biopsy-proven non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) respectively. GDF15 levels were significantly higher in NASH patients than in controls (P=.010) or NAFL patients (P=.001). Subjects with advanced fibrosis (≥F3) also showed higher GDF15 levels compared to the others (F0-2; P<.001). Among NAFLD patients, the highest quartile of GDF15 levels was significantly associated with a risk of advanced fibrosis even after adjustment for age, gender, body mass index, smoking status, hypertension, diabetes, aspartate aminotransferase, platelet, albumin, insulin resistance and low skeletal muscle mass (odds ratio, 4.27; 95% confidence interval, 1.04-17.63), but not with NASH risk. GDF15 levels showed a significant positive correlation with liver stiffness (Spearman's ρ, .525; P<.001). Palmitate treatment increased the GDF15 mRNA expression level significantly in Kupffer cells, but not in hepatocytes. In LX-2 cells, GDF15 treatment resulted in enhanced expression of α-smooth muscle actin and collagen I, as well as phosphorylation of SMAD2 and SMAD3. Our findings suggest that GDF15 may serve as a novel biomarker of advanced fibrosis in NAFLD, thereby indicating the need for urgent anti-fibrotic pharmacotherapy.

Sex-specific differences in the modulation of Growth Differentiation Factor 15 (GDF15) by hyperoxia in vivo and in vitro: Role of Hif-1α

Male premature neonates are more susceptible than females to the development of bronchopulmonary dysplasia (BPD). The reasons underlying sexually dimorphic outcomes in premature neonates are not known. GDF15 (Growth and differentiation factor 15) is a secreted cytokine and plays a role in cell proliferation, apoptosis, and angiogenesis. In this study, we sought to elucidate the sex-specific expression of Gdf15 in the lung in vivo in neonatal hyperoxic lung injury and its regulation by Hif-1α, and to delineate the differences in GDF15 expression in male and female human umbilical venous endothelial cells in an in vitro model of oxygen toxicity. Following hyperoxia exposure (95% FiO2, PND (postnatal day 1–5: saccular stage of lung development), neonatal male mice (C57BL/6) show increased GDF15 and decreased HIF-1α expression compared to female mice. For the in vitro experiments, male and female HUVECs were exposed to room air condition (21% O2, 5% CO2) or in hyperoxia condition (95% O2, 5% CO2) for up to 72h. Male HUVECs had greater expression of GDF15 mRNA and protein. To study the inter-relationship between GDF15 and HIF-1α, we measured the expression of GDF15 in H441 cells after HIF-1α knockdown using promoter dual luciferase reporter assay, which showed that HIF-1α and GDF15 expression are inversely related under normoxia and hyperoxia. The results indicate that sex differences exist in the expression and modulation of GDF15 by HIF-1α in neonatal hyperoxic injury both in vivo and in vitro. These differences could explain in part the mechanisms behind sex-specific differences in BPD.

Growth differentiation factor 15 as a marker of ineffective erythropoiesis in patients with chronic C virus infection

Objective The aim of this study was to determine the expression of growth differentiation factor 15 (GDF-15) in patients with chronic hepatitis C virus and its association with iron-loading anemia in these patients. Background Significant shortened red cell survival has been reported in patients with liver diseases even in the absence of anemia. The mechanism for the observed decreased red cell lifespan is not fully understood, and it is most probably multifactorial. GDF-15, a member of the transforming growth factor-β super family, was first cloned from human monocytoid cell line and was found to inhibit tumor necrotizing factor production by macrophages and negatively regulate hepcidin. Recent studies suggest that GDF-15 levels increase in conditions of cell stress and apoptosis. In bone marrow (BM), GDF-15 increases in case of ineffective erythropoiesis. Patients and methods This study was carried out at Clinical Pathology Department, Faculty of Medicine and National Liver Institute, Menoufia University, in the period from May 2013 to May 2015. The study included 70 individuals: 50 patients with compensated chronic hepatitis C with unexplained anemia and 10 patients with idiopathic thrombocytopenic purpura who had normal red blood cell counts and no signs of erythroid dysplasia, as a control group for BM expression of GDF-15. In addition, 10 unrelated healthy age-matched and sex-matched adult individuals were included as a normal control group. Serum GDF-15 was measured by ELISA, and GDF-15 mRNA was measured by real-time RT-PCR. Results There were significant differences between the different studied groups regarding iron profile, GDF-15 serum level, and BM expression of GDF-15 mRNA, being higher in patients with chronic hepatitis C than other groups. GDF-15 was positively correlated with serum iron indices and negatively correlated with hemoglobin concentration. Conclusion Ineffective erythropoiesis contributes to iron overload and anemia in patients with chronic hepatitis C.

CD34/EPO-R Double Positive MDS Cells Produce Erythroferrone in Response to Erythropoietin

Background. It has been reported that iron absorption from gastrointestinal tract was enhanced in a subset of patients with myelodysplastic syndrome (MDS) exhibiting ineffective erythropoiesis. Iron absorption was achieved via an iron transporter ferroportin which was downregulated by hepcidin. Recently, three erythroid regulators such as growth differentiation factor 15 (GDF15), twisted gastrulation protein homolog 1 (TWSG1) and erythroferrone (ERFE) which down regulated hepatic hepcidin production has been identified. However, it has been not yet clarified which molecules could contribute to the increased iron absorption in patients with MDS.Materials and Methods. In the present study, we examined the expression level of GDF15, TWSG1 and ERFE mRNA during ex vivo erythroid differentiation from CD34+ bone marrow (BM) cells in the presence of 4 U/mL erythropoietin (EPO), 100 U/mL interleukin-3, 10 ng/mL stem cell factor, 20 ng/mL insulin-like growth factor (IGF)-1 and 500 micro g/mL iron-saturated transferrin. We further analyzed the expression level of GDF15 and ERFE in BM mononuclear cells (MNCs) derived from BM derived from MDS patients and lymphoma patients without BM involvement as a control by using quantitive RT-PCR. The expression of EPO-R was analyzed by flow cytometry. The CD34+ MDS cells were seeded on fibronectin substratum in 5 mL of a serum-free medium supplemented with 50 ng/mL human thrombopoietin (TPO), 10 ng/mL human SCF, 50 ng/mL human Fms-related tyrosin kinase 3 ligand (FLT3LG) and 100 ng/mL human delta like protein 4 (DLL4) with or without 4 U/mL EPO. For analysis of CD34+ cells, a GEO dataset (GSE58831) was downloaded as a matrix by GEOquery package (Bioconductor). The numerical data of the matrix were normalized by quantile normalization using limma package. Clinical and sequencing data were downloaded from supplementary materials. Those were combined with a GEO dataset (GSE58831) before analysis.Results. The level of ERFE mRNA was dramatically increased during erythroid differentiation from control CD34+ cells in response to EPO in vitro (Figure 1) although increase of the level of GDF15 and TWSG1 was marginal. Moreover, the level of ERFE mRNA in BM MNCs derived from MDS patients was significantly higher than that from control. Furthermore, the expression level of ERFE mRNA correlated with the percentage of CD34+ cells, but not percentage of erythroblasts derived from MDS patients. Using GEO data sets (GSE58831), the level of ERFE mRNA in CD34+ cells derived from MDS patients was significantly elevated as compared with that from healthy volunteers. Importantly, flow cytometric analysis indicated that CD34+ MDS cells highly expressed EPO receptors and the level of ERFE mRNA in CD34+ cells in a subset of MDS patients was enhanced after exposure of EPO ex vivo. In addition, the level of ERFE mRNA positively correlated with the level of EPO-R in CD34+ MDS cells (GSE58831).Conclusion. These results indicated that CD34+/EPO-R+ double positive MDS cells is one of the major sources of ERFN. The level of ERFE in CD34+ MDS cells may be associated with abnormal iron metabolism in MDS patients. These finding may be important for understanding the abnormal iron metabolism and predicting the efficacy of EPO administration. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Abstract 358: The role of GDF-15 on docetaxel resistance in lung cancer

Abstract [Background] Lung cancer is the leading cause of cancer death in many countries. One of major reasons for poor prognosis is that lung cancer reveals resistance to therapeutic drugs. Thus, it is important to elucidate the mechanisms of resistance to drugs. Growth differentiation factor-15 (GDF-15) is the member of the transforming growth factor-β superfamily, and it shows multiple functions such as control of development, anti-inflammation, immunosuppression. In prostate cancer cell, it is reported that GDF-15 are related to cancer progression, survival, recurrence, and chemo-resistance. In this study, we examined the roles of GDF-15 in lung cancer, especially about chemo-resistance. [Materials and Methods] We used three lung cancer cell lines (HCC4006, HCC4006-DR which acquired docetaxel (DOC) resistance after long term exposure for DOC with stepwise manner, and A549), a non-malignant immortalized fibroblast cell (OUMS-24), and two non-malignant immortalized bronchial epithelial cells (HBEC-5KT and BEAS-2B). We also used lung cancer-associated fibroblast (CAF) and normal fibroblast which were established by primary culture of surgically resected lung cancer tissue and corresponding distant normal lung tissue from two patients, respectively. A quantitative reverse transcriptional real time PCR assay were performed to quantify GDF-15 mRNA expression. Apoptosis were evaluated by cleaved caspase-3 assay. The MTS assay was performed to calculate IC50 values for DOC. [Results] GDF-15 mRNA expression level was very low in parental HCC4006 but high in HCC4006-DR and moderate in A549. After DOC treatment, GDF-15 expression was highly upregulated in a fibroblast cell (OUMS-24) but not in HBEC-5KT and BEAS-2B. Furthermore, upregulation of GDF-15 expression after DOC treatment was more highly promoted in two CAFs than corresponding normal fibroblasts. DOC treatment induced apoptosis in HCC4006, but DOC-induced apoptosis was inhibited by injection of DOC protein. In addition, sensitiveness for DOC was also inhibited by injection of DOC protein. [Conclusion] DOC treatment promotes upregulation of GDF-15 expression especially in CAFs. Secreted GDF-15 inhibits DOC-induced apoptosis and sensitiveness for DOC treatment. These facts suggest that GDF-15, which is highly produced by CAFs, may play an important role of DOC resistance in lung cancer. Citation Format: Mototsugu Watanabe, Yasutaka Masada, Shinsuke Hashida, Tomoaki Ohtsuka, Ken Suzawa, Yuho Maki, Hiromasa Yamamoto, Junichi Soh, Hiroaki Asano, Kazunori Tsukuda, Shinichi Toyooka, Shinichiro Miyoshi. The role of GDF-15 on docetaxel resistance in lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 358. doi:10.1158/1538-7445.AM2015-358

Growth/differentiation factor-15 and its role in peripheral nervous system lesion and regeneration.

Growth/differentiation factor-15 (GDF-15) is a distant member of the transforming growth factor beta (TGF-β) superfamily. It is widely distributed in the nervous system, where it has been shown to play an important role in neuronal maintenance. The present study investigates the role of endogenous GDF-15 in sciatic nerve (SN) lesions using wild-type (WT) and GDF-15 knock-out (KO) mice. SN of 5-6-month-old mice were crushed or transected. Dorsal root ganglia (DRG) and nerve tissue were analyzed at different time points from 6h to 9weeks post-lesion. Both crush and transection induced GDF-15 mRNA and protein in the distal portion of the nerve, with a peak at day 7. DRG neuron death did not significantly differ between the genotypes; similarly, remyelination of regenerating axons was not affected by the genotype. Alternative macrophage activation and macrophage recruitment were more pronounced in the KO nerve. Protrusion speed of axons was similar in the two genotypes but WT axons showed better maturation, as indicated by larger caliber at 9weeks. Furthermore, the regenerated WT nerve showed better performance in the electromyography test, indicating better functional recovery. We conclude that endogenous GDF-15 is beneficial for axon regeneration following SN crush.

Regulation and effects of GDF-15 in the retina following optic nerve crush

Growth/differentiation factor-15 (GDF-15) is a distant member of the transforming growth factor-β superfamily and is ubiquitously expressed in the central nervous system. It is prominently upregulated in cerebral cortical and ischemic lesion paradigms. GDF-15 robustly promotes the survival of lesioned nigrostriatal dopaminergic neurons in vivo; GDF-15-deficient mice exhibit progressive postnatal motor and sensory neuron losses implying essential functions of GDF-15 in neuronal survival. We show that GDF-15 mRNA and protein are, respectively, six-fold and three-fold upregulated in the murine retina at 1 day after optic nerve crush, slightly elevated mRNA levels being maintained until day 28. However, the magnitude and time course of retinal ganglion cell (RGC) death are indistinguishable in knockout and control mice. Selected mRNAs implicated in the regulation of the death vs. survival of RGCs, including ATF3, Bad, Bcl-2 and caspase-8, were similarly regulated in both knockout and control retinae. Immunohistochemistry for tyrosine hydroxylase and choline acetyltransferase revealed no differences in staining patterns in the two genotypes. mRNA and protein levels of galanin, a putative neuroprotective factor and positive regulator of neuron survival and axonal regeneration, were prominently upregulated after crush in knockout retinae at day 3, as compared with control retinae, suggesting that GDF-15 acts as a physiological regulator of galanin. GDF-15 is therefore prominently upregulated in the retina after optic nerve crush but does not directly interfere with the magnitude and temporal progression of RGC death.

GDF15‐mediated upregulation of ferroportin plays a key role in the development of hyperferritinemia in children with hemophagocytic lymphohistiocytosis

Growth differentiation factor 15 (GDF15), a divergent TGFβ superfamily, has recently been implicated in the modulation of iron homeostasis, acting as an upstream negative regulator of hepcidin, the key iron regulatory hormone produced primarily by hepatocytes. However, little is known about possible roles that GDF15 might play in the regulation of iron homeostasis and development of hyperferritinemia in children with hemophagocytic lymphohistiocytosis (HLH). We compared serum GDF15 level and mRNA expressions of GDF15 and key molecules of iron metabolism, and made correlations between their expressions in children with HLH and control children. Serum GDF15 level was remarkably higher in HLH group than that in controls, with median serum concentration of 1,700 and 260 pg/ml, respectively (P < 0.001). In addition, GDF15 mRNA was significantly upregulated but independent of hypoxia-inducible factor-mediated oxygen signaling pathway. More importantly, GDF15 induction was positively correlated to upregulation of ferroportin, the only cellular iron exporter, and to upregulation of ferritin heavy chain. Our study suggests that GDF15 induction helps suppress further activation of macrophages in stressful physiologic states as HLH, and is intimately implicated in the development of hyperferritinemia by modulating the hepcidin-ferroportin axis, resulting in enhanced ferroportin-mediated iron efflux.

High Expression of p53 and Growth Differentiation Factor-15 in Beta-Thalassemia.

Abstract 2130Beta thalassemia phenotype is exacerbated by marrow expansion, tissue hypoxia, and erythroblast apoptosis caused by globin chain imbalances. The expanded erythroid compartment contributes to iron overload in thalassemia syndromes by inhibiting hepcidin expression. It was shown that growth differentiation factor 15 (GDF15), a member of the transforming growth factor-b super family was elevated in b thalassemia and contributes to hepcidin suppression. p53 plays a key role in the cellular response to stress by activating a subset of genes responsible for cell cycle arrest and apoptosis in tumours. Recently association of P53 with defective erythropoiesis has been demonstrated in Diamond Blackfan anemia. In this study we analyzed the expression of these genes in patients with b thalassemia. We observed a higher expression of p53 and p21 in b thalassemia. Thirty six patients with b thalassemia (b thalassemia major=27; b thalassemia intermedia=9) were included in the study. Diagnosis was based on clinical, haematological and molecular parameters. Healthy volunteers were included as controls (n=28). Serum GDF15 levels were measured using ELISA (Ray Biotech, Inc, Georgia) and ferritin by chemiluminescent immunoassay. Reticulocytes from patients and controls were isolated from peripheral blood using cellulose columns. RNA was extracted by Trizol method and cDNA was synthesised. The relative expression of p53, GDF15 and p21 mRNA was analyzed using actin as the control gene. Approximately 1×107 reticulocytes were used to prepare whole cell lysate for western blot (controls=6, patients=6). As expected serum ferritin (Median-3544ng/ml) and GDF15 levels (Median-6059.87pg/ml) were higher in the patient cohort as compared to controls. Higher expression of p21 and p53 was observed in patients as compared to controls (Table.1). P53 expression strongly correlated with GDF15 expression at the mRNA (r=0.649; p=0.000) and protein level (r=0.406; p=0.049) in b thalassemia major. The p53 expression also significantly correlated with serum ferritin levels (r=0.562; p=0.003) in the thalassemia major cohort. We also assessed the expression of p21 one of the targets of p53 in these samples. Significantly higher expression of p21 was observed in the patients than in controls (Median dCt-8.34 vs 10.78; p=0.000). Western blot analysis carried out in six b-thalassemia major and six controls also showed a higher expression of p53 in the patients as compared to controls. Higher expression of these genes was also observed in b thalassemia intermedia as compared to controls but not different from thalassemia major (Table.1). GDF15 has two p53 response elements in the promoter region and p53 binding activates GDF15 in the erythroid compartment (Osada et.al 2007). P53 may thus contribute to GDF15 elevation in beta thalassemia.Table 1Gene expression in beta thalassemiaFerritin (ng/ml)GDF15 (pg/mL)Gene Expression Median dCt (Range)GDF15p53p21b Thalassemia Major (n=27)3544 (569-12631)6059.87 (2518-29379)2.97 (−5.28-8.81)7.68 (ϕ1.75-10.48)8.33 (4.87-10.9)b Thalassemia Intermedia (n=9)950.35 (84.80-6634)7576.52 (5391-16014)4.27 (−3.08-8.77)7.69 (−7.41-10.91)8.03 (6.03-10.82)Controls (n=28)26.25 (5-276)328.95 (125-677)5.92 (0.88-10.93)10.15 (4.68-12.84)10.78 (5.65-13.80) Disclosures:Edison:Department Of Biotechnology, Government of India: Research Funding.

Circulating growth differentiation factor‐15 correlates with myocardial fibrosis in patients with non‐ischaemic dilated cardiomyopathy and decreases rapidly after left ventricular assist device support

Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine and is emerging as a biomarker of cardiac remodelling. Left ventricular assist devices (LVADs) provide unloading of the left ventricle, resulting in partial reverse remodelling. Our aim was to study GDF-15 in patients with a non-ischaemic dilated cardiomyopathy (DCM) during LVAD support. We analysed circulating GDF-15 in 30 patients before and 1, 3, and 6 months after LVAD implantation and before heart transplantation or explantation. In addition, mRNA and protein expression of GDF-15 were evaluated in myocardial tissue obtained prior to and after LVAD support. Circulating GDF-15 was significantly higher before LVAD implantation as compared with healthy controls (P < 0.001). After 1 month of mechanical support, GDF-15 levels were significantly decreased compared with pre-implantation levels (P < 0.001) and remained stable thereafter. Circulating GDF-15 was significantly correlated with kidney function and the severity of myocardial fibrosis. Interestingly, GDF-15 mRNA and protein expression in the myocardium were hardly detectable. High circulating levels of GDF-15 in patients with end-stage non-ischaemic DCM correlate with myocardial fibrosis and kidney function and decline strongly after 1 month of mechanical unloading, remaining stable thereafter. However, cardiac mRNA and protein expression of GDF-15 are very low, suggesting that the heart is not an important source of GDF-15 production in these patients.

GDF‐15 in heart failure: providing insight into end‐organ dysfunction and its recovery?

GDF‐15 in heart failure: providing insight into end‐organ dysfunction and its recovery?

GDF15, a distinct TGFβ family member, is differentially regulated in spondyloarthritides compared to other rheumatic diseases

IntroductionThe transforming growth factor β (TGFβ) superfamily consists of a number of cytokines that regulate a variety of cellular processes. Growth differentiation factor 15 (GDF15) is a distant member of...

E0027 Growth differentiation factor 15 induce the proliferation of cardiac fibroblasts in a dose dependent manner

ObjectiveGrowth differentiation factor 15(GDF-15) is a member of Transforming growth factor-β superfamily which is one of the most important profibrotic protein released during Inflammation. It has been suggested that GDF-15...

Circulating and Placental Growth-Differentiation Factor 15 in Preeclampsia and in Pregnancy Complicated by Diabetes Mellitus

Growth-differentiation factor 15 (GDF-15), a stress-responsive transforming growth factor-beta-related cytokine, is emerging as a new risk marker in patients with cardiovascular disease. We explored GDF-15 in preeclampsia and in diabetic pregnancies, because these conditions are associated with augmented risk for cardiovascular disease, both in mother and in offspring. Plasma from pregnant women (n=267; controls: n=59, preeclampsia: n=85, diabetes mellitus: n=112, and superimposed preeclampsia in diabetes mellitus: n=11), fetal plasma (n=72), and amniotic fluid (n=99) were analyzed by immunoassay for GDF-15. Placental GDF-15 mRNA and protein expression levels were analyzed by quantitative real-time PCR and immunoblots in 78 and 18 pregnancies, respectively. Conditioned media from preeclamptic (n=6) and control (n=6) villous placenta explants were analyzed by immunoassay for GDF-15. Median maternal GDF-15 concentration was elevated in those with diabetes mellitus, as compared with controls (91 549 versus 79 875 ng/L; P=0.02). Median GDF-15 concentration was higher in patients with preeclampsia than in controls in term maternal blood samples (127 061 versus 80 319 ng/L; P<0.001). In the fetal circulation and amniotic fluid, GDF-15 was elevated in preeclampsia and superimposed preeclampsia in diabetes mellitus, as compared with controls. GDF-15 placental mRNA expression was elevated in preeclampsia, as compared with controls (P=0.002). Placenta immunoblots confirmed a single GDF-15 protein band, and a time-dependent increase in GDF-15 protein was detected in the conditioned media. Our study is the first to show that GDF-15 is dysregulated, both in preeclampsia and in diabetic pregnancies. The mechanisms and diagnostic implications of these findings remain to be explored.

Cleavage of growth differentiation factor 15 (GDF15) by membrane type 1‐matrix metalloproteinase abrogates GDF15‐mediated suppression of tumor cell growth

Growth differentiation factor 15 (GDF15), a transforming growth factor (TGF)-beta superfamily member, has been cloned from a placenta cDNA library as a gene product that has promoted activation of pro-matrix metalloproteinase (MMP)2 mediated by membrane type (MT)1-MMP. Expression of MT1-MMP in HEK293T cells caused cleavage of the GDF15 mature form at N(252)-M(253) to produce a 6-kDa C-terminal fragment. Treatment of MCF7 cells with GDF15 induced activation of p53 and enhanced expression of p21, which was abrogated by MT1-MMP expression. GDF15 mRNA synthesis was also shown to be induced by treatment of cells with GDF15. Treatment of MCF7 cells with GDF15 caused suppression of cell proliferation. However, proliferation of MCF7 cells transfected with the MT1-MMP gene was not affected by GDF15 treatment, but was suppressed in the presence of the MMP inhibitor BB94. HT1080 cells transfected with the GDF15 gene, which endogenously express MT1-MMP, synthesize a high-level GDF15 precursor form and a low-level mature form, and treatment of cells with BB94 enhanced production of the GDF15 mature form. Consistent with GDF15 production, HT1080 cells transfected with the GDF15 gene proliferated almost equally with control cells, and addition of BB94 effectively suppressed growth of HT1080 cells transfected with the GDF15 gene concomitant with the accumulation of the GDF15 mature form, but not control cells. These results suggest that MT1-MMP contributes to tumor cell proliferation through the cleavage of GDF15, which down-regulates cell proliferation by inducing activation of p53 and p21 synthesis.

The Transforming Growth Factor-β Superfamily Member Growth-Differentiation Factor-15 Protects the Heart From Ischemia/Reperfusion Injury

Data from the Women's Health Study show that serum levels of growth-differentiation factor-15 (GDF-15), a distant member of the transforming growth factor-beta superfamily, are an independent risk indicator for adverse cardiovascular events. However, the cellular sources, upstream regulators, and functional effects of GDF-15 in the cardiovascular system have not been elucidated. We have identified GDF-15 by cDNA expression array analysis as a gene that is strongly upregulated by nitrosative stress in cultured cardiomyocytes isolated from 1- to 3-day-old rats. GDF-15 mRNA and pro-peptide expression levels were also induced in cardiomyocytes subjected to simulated ischemia/reperfusion (I/R) via NO-peroxynitrite-dependent signaling pathways. GDF-15 was actively secreted into the culture supernatant, suggesting that it might exert autocrine/paracrine effects during I/R. To explore the in vivo relevance of these findings, mice were subjected to transient or permanent coronary artery ligation. Myocardial GDF-15 mRNA and pro-peptide abundance rapidly increased in the area-at-risk after ischemic injury. Similarly, patients with an acute myocardial infarction had enhanced myocardial GDF-15 pro-peptide expression levels. As shown by immunohistochemistry, cardiomyocytes in the ischemic area contributed significantly to the induction of GDF-15 in the infarcted human heart. To delineate the function of GDF-15 during I/R, Gdf-15 gene-targeted mice were subjected to transient coronary artery ligation for 1 hour followed by reperfusion for 24 hours. Gdf-15-deficient mice developed greater infarct sizes and displayed more cardiomyocyte apoptosis in the infarct border zone after I/R compared with wild-type littermates, indicating that endogenous GDF-15 limits myocardial tissue damage in vivo. Moreover, treatment with recombinant GDF-15 protected cultured cardiomyocytes from apoptosis during simulated I/R as shown by histone ELISA, TUNEL/Hoechst staining, and annexin V/propidium iodide fluorescence-activated cell sorting (FACS) analysis. Mechanistically, the prosurvival effects of GDF-15 in cultured cardiomyocytes were abolished by phosphoinositide 3-OH kinase inhibitors and adenoviral expression of dominant-negative Akt1 (K179M mutation). In conclusion, our study identifies induction of GDF-15 in the heart as a novel defense mechanism that protects from I/R injury.

Protein profiling of microdissected prostate tissue links growth differentiation factor 15 to prostate carcinogenesis.

Identification of proteomic alterations associated with early stages in the development of prostate cancer may facilitate understanding of progression of this highly variable disease. Matched normal, high-grade prostatic intraepithelial neoplasia (hPIN) and prostate cancer cells of predominantly Gleason grade 3 were procured by laser capture microdissection from serial sections obtained from snap-frozen samples dissected from 22 radical prostatectomy specimens. From these cells, protein profiles were generated by surface-enhanced laser desorption/ionization-time of flight mass spectrometry. A 24-kDa peak was observed at low or high intensity in profiles of prostate cancer cells in 19 of 27 lesions and at low intensity in 3 of 8 hPIN lesions but was not detectable in matched normal cells. SDS-PAGE analysis of prostate cancer and matched normal epithelium confirmed expression of a prostate cancer-specific 24-kDa protein. Mass spectrometry and protein data-based analysis identified the protein as the dimeric form of mature growth differentiation factor 15 (GDF15). The increased expression of mature GDF15 protein in prostate cancer cells cannot be explained on the basis of up-regulation of GDF15 mRNA because reverse transcription-PCR analysis showed similar amounts of transcript in normal, hPIN, and prostate cancer cells that were obtained by laser capture microdissection in the same set of serial sections from which the protein profiles were obtained. Our findings suggest that early prostate carcinogenesis is associated with expression of mature GDF15 protein.

Induction of MIC-1/growth differentiation factor-15 following bile duct injury.

Macrophage inflammatory peptide-1 (MIC-1)/growth/differentiation factor-15 (GDF-15) is a divergent member of the transforming growth factor-beta superfamily cloned by others and us. MIC-1/GDF-15 is expressed in the liver, breast, and colon. Studies have demonstrated a growth-inhibiting effect of MIC-1/GDF-15 on colon and breast cancer cell lines in vitro and on tumor growth in vivo. We previously reported that MIC-1 expression is rapidly induced after a wide variety of murine acute and chronic liver injuries including aniline dye administration. I hypothesized, therefore, that MIC-1/GDF-15 may be a mediator of biliary tract injury and could play a role in regulation of bile duct proliferation. C57BL/6 mice underwent surgical ligation of the common bile duct. Northern blot analysis revealed a time-dependent induction of MIC-1/GDF-15 mRNA in the liver. In situ hybridization of liver sections for MIC-1/GDF-15 expression after bile duct ligation demonstrated a zone 1 or periportal expression pattern, consistent with expression of MIC-1 in periductular hepatocytes. Northern blot analysis of liver mRNA from patients with sclerosing cholangitis or cirrhosis also demonstrated enhanced expression of MIC-1/GDF-15. MIC-1/GDF-15 is expressed after bile duct injury in mice and humans. Taken together with the previously demonstrated growth inhibitory effects of MIC-1/GDF-15 on normal and transformed cells, MIC-1/GDF-15 may play a role in regulation of bile duct proliferation and biliary tumor formation.